PURPOSE: Much debate has arisen about whether antioxidant supplementation alters the efficacy of cancer chemotherapy. Some have argued that antioxidants scavenge the reactive oxygen species integral to the activity of certain chemotherapy drugs, thereby diminishing treatment efficacy. Others suggest antioxidants may mitigate toxicity and thus allow for uninterrupted treatment schedules and a reduced need for lowering chemotherapy doses. The objective of this study is to systematically review the literature in order to compile results from randomized trials that evaluate concurrent use of antioxidants with chemotherapy.

DESIGN: MEDLINE, Cochrane, CinAhl, AMED, AltHealthWatch and EMBASE databases were searched. Only randomized, controlled clinical trials that reported survival and/or tumor response were included in the final tally. The literature searches were performed in duplicate following a standardized protocol. No meta-analysis was performed due to heterogeneity of tumor types and treatment protocols used in trials that met the inclusion criteria.

RESULTS: Of 845 articles considered, 19 trials met the inclusion criteria. Antioxidants evaluated were: glutathione (7), melatonin (4), vitamin A (2), an antioxidant mixture (2), vitamin C (1), N-acetylcysteine (1), vitamin E (1) and ellagic acid (1). Subjects of most studies had advanced or relapsed disease.

CONCLUSION: None of the trials reported evidence of significant decreases in efficacy from antioxidant supplementation during chemotherapy. Many of the studies indicated that antioxidant supplementation resulted in either increased survival times, increased tumor responses, or both, as well as fewer toxicities than controls; however, lack of adequate statistical power was a consistent limitation. Large, well-designed studies of antioxidant supplementation concurrent with chemotherapy are warranted.

Background

Although environmental lead exposure is associated with significant deficits in cognition, executive functions, social behaviors, and motor abilities, the neuroanatomical basis for these impairments remains poorly understood. In this study, we examined the relationship between childhood lead exposure and adult brain volume using magnetic resonance imaging (MRI). We also explored how volume changes correlate with historic neuropsychological assessments.

Methods and Findings

Volumetric analyses of whole brain MRI data revealed significant decreases in brain volume associated with childhood blood lead concentrations. Using conservative, minimum contiguous cluster size and statistical criteria (700 voxels, unadjusted p < 0.001), approximately 1.2% of the total gray matter was significantly and inversely associated with mean childhood blood lead concentration. The most affected regions included frontal gray matter, specifically the anterior cingulate cortex (ACC). Areas of lead-associated gray matter volume loss were much larger and more significant in men than women. We found that fine motor factor scores positively correlated with gray matter volume in the cerebellar hemispheres; adding blood lead concentrations as a variable to the model attenuated this correlation.

Conclusions

Childhood lead exposure is associated with region-specific reductions in adult gray matter volume. Affected regions include the portions of the prefrontal cortex and ACC responsible for executive functions, mood regulation, and decision-making. These neuroanatomical findings were more pronounced for males, suggesting that lead-related atrophic changes have a disparate impact across sexes. This analysis suggests that adverse cognitive and behavioral outcomes may be related to lead's effect on brain development producing persistent alterations in structure. Using a simple model, we found that blood lead concentration mediates brain volume and fine motor function.

Background: The treatment of pelvic malignancies (uterine, cervix, rectum, etc) often include radiation. Radiation-induced late side effects (longer than 3 months) are developed in 5–10% of those patients. We wanted to investigate the efficacy of hyperbaric oxygen therapy (HBOT) in the management of those patients. Methods: Thirteen women were evaluated. The primary cancer sources were: cervix (7), vagina (2), uterus (2), rectum (1) and bladder (1). All patients were treated with a full pelvic dose of radiotherapy. Eight patients also underwent post-radiation surgery (4 post-hysterectomy, 1 post-colectomy, 1 post-vaginectomy, 1 post-cystectomy and 1 post-exanteration). Eleven patients suffered from pelvic pain, 7 from chronic cystitis (including 2 with vesico-vaginal fistulas), 7 had chronic proctitis (including 2 with recto-vaginal fistulas), 3 had long-standing vaginal ulcers, and one presented with a long-standing open skin wound following surgery. All patients underwent imaging studies and biopsies to rule out active malignant disease, and all received HBOT 100% oxygen, at 2 absolute atmospheres, for 90 minutes (2ATA 90 min). Results: The mean patient age was 61 years (range 32–88). The mean time between completion of radiation therapy and onset of symptoms was 32 months (range 4–60). The patients received an average of 27 HBOTs (range 16–40). Twelve patients reported improvement in pelvic pain, bladder and bowel symptoms and decrease in vaginal discharge. One patient developed lung metastasis and another developed pelvic recurrence. No patient reported side effects associated with HBOT. Conclusion: HBOT appears to be safe and effective in the management of pelvic radiation-induced late side effects, such as soft tissue necrosis (skin and vagina), cystitis, proctitis and fistulas.

Therapeutic irradiation is commonly used to treat clinically localized prostate cancer. Although radiation therapy is effective for localized prostate cancer, the rectum is often affected because of its proximity to the treated tumour. The incidence of severe chronic radiation proctitis induced by pelvic irradiation is reported to be 2–5%. The symptoms of chronic radiation proctitis include diarrhoea, tenesmus, abdominal pain and rectal bleeding, and perforation, necrosis, stenosis and ulceration of the intestine may occur. The natural history of chronic radiation proctitis is unpredictable. While some patients with mild symptoms may experience remission, others suffer a progressively worsening course that can result in a life-threatening condition.

Chronic radiation proctitis is generally considered to be difficult to manage. Medical treatment with a low–residue diet and steroidal or nonsteroidal enemas has been disappointing. Laser therapy or electrocoagulation is often used to halt rectal bleeding. Although these attempts are initially successful in many patients, recurrence of bleeding is a common problem. Although faecal diversion is the most common operative procedure, this may not always control rectal bleeding and surgical resection of the involved segment may be necessary. Surgical complications are common, with a morbidity and mortality of 10–80%; thus an effective alternative treatment is required, particularly as medical treatment often fails. Hyperbaric oxygen therapy (HBOT) was recently reported to be safe and effective for the treatment of chronic radiation proctitis. We report the outcome of HBOT in four patients with chronic radiation proctitis.

Fasting mongrel dogs underwent hyperbaric oxygen treatment (HBOT), recombinant tissue plasminogen activator (rt-PA) treatment, and simultaneous HBOT and rt-PA treatment following prior experimental left anterior descending coronary artery occlusion for 2 hours. Thrombosis in and around a copper coil was recorded angiographically at regular intervals, and immediately prior to treatment conclusion. Controls (n = 10) were untreated. Group two animals (n = 10) were treated additionally with 90 minutes of HBOT at 2 atm absolute. Group three animals (n = 8) were treated additionally with 50 mg rt-PA over 90 minutes. Group four animals (n = 10) were treated additionally with simultaneous HBOT and rt-PA over 90 minutes. Myocardial injury was determined by a combination of triphenyltetrazolium chloride histochemical staining and by formazan dye extraction. Damage was measured as a percent of left ventricular cross-sectional area studied. HBOT alone restored 35.9% of oxidative enzyme activity (p greater than 0.001). Treatment with rt-PA alone restored 48.9% of enzyme activity (p greater than 0.001). The combination of HBOT and simultaneous rt-PA resulted in 96.9% restoration of oxidative enzyme activity versus the control group (p greater than 0.001)

Background: The relation between plasma vitamin C and risk of stroke remains unclear. Although clinical trials showed no significant benefit of vitamin C supplementation in reducing stroke risk, they were not able to examine the relation between plasma vitamin C concentrations and stroke risk in a general population.

Objective: The objective was to examine the relation between baseline plasma vitamin C concentrations and risk of incident stroke in a British population.

Design: A population-based prospective study was conducted in 20 649 men and women aged 40–79 y without prevalent stroke at baseline and participating in the European Prospective Investigation into Cancer–Norfolk prospective population study. The participants completed a health questionnaire and attended a clinic during 1993–1997 and were followed up for incident strokes through March 2005.

Results: Over 196 713 total person-years (average follow-up: 9.5 y), 448 incident strokes occurred. In a Cox proportional hazards model, persons in the top quartiles of baseline plasma vitamin C concentrations had a 42% lower risk (relative risk: 0.58; 95% CI: 0.43, 0.78) than did those in the bottom quartile, independently of age, sex, smoking, body mass index, systolic blood pressure, cholesterol, physical activity, prevalent diabetes and myocardial infarction, social class, alcohol consumption, and any supplement use. Similar results were obtained after exclusion of persons with illnesses, users of ascorbic acid–containing supplements, and persons with a history of early strokes during the initial 2 y of follow-up.

Conclusions: Plasma vitamin C concentrations may serve as a biological marker of lifestyle or other factors associated with reduced stroke risk and may be useful in identifying those at high risk of stroke.

Abstract

Objective  To test the ability of alpha-lipoic acid (LA) to attenuate the development of collagen-induced arthritis (CIA) in mice.
Methods  Mice were divided into three groups and treated with intraperitoneal administration of LA (10 or 100 mg/kg) or placebo. Clinical, histologic, and biochemical parameters were assessed. Human synovial fibroblasts and peripheral blood mononuclear cells were cocultured in various concentrations of LA to evaluate the effects on osteoclastogenesis.
Results  LA was associated with a dose-dependent reduction of CIA, as well as preventing bone erosion and destructive changes. Intracellular reactive oxygen species in lymphocytes obtained from inguinal lymph nodes, which was significantly higher in CIA than control mice, was significantly reduced in CIA by LA. The concentrations of TNF-a, IL-1β, and IL-6 in the paws, and synovial NF-κB binding, all of which were markedly higher in CIA than control mice, were reduced by treatment with LA. In addition, LA inhibited the formation of human osteoclasts in vitro.
Conclusion  Amelioration of joint disease by LA was associated with reduction in oxidative stress, as well as inhibition of inflammatory cytokine activation and NF-κB DNA binding activity. Moreover, LA inhibited bone destruction in vivo and osteoclastogenesis in vitro. Collectively, these results indicate that LA may be a new adjunctive therapy for rheumatoid arthritis.

Purpose

The purpose of this article is to review current evidence available for -lipoic acid (ALA) and its ability to improve symptoms of peripheral diabetic neuropathy (PDN).

Methods

This article searched MEDLINE from 1966 to November 2005 to identify clinical trials that supplemented ALA to individuals with type 1 or type 2 diabetes and positive sensory symptoms of PDN. Clinical trials to be included in this review met specific criteria of randomization, double masking, and placebo-controlled design.

Results

The search results produced 5 clinical trials that met the prerequisites for this review. ALA appears to improve neuropathic symptoms and deficits when administered via parenteral supplementation over a 3-week period. Oral treatment with ALA appears to have more conflicting data whether it improves sensory symptoms or just neuropathic deficits alone. An oral regimen of ALA and optimal length of treatment remains unclear. Both parenteral and up to a 2-year time period of oral supplementation of ALA appears to be safe without affecting glycemic control.

Conclusions

Based on these results, ALA should be considered as a treatment option for patients with PDN. When discussing supplementation with patients, it is important to discuss potential side effects; vitamin, mineral, and drug interactions; and current evidence available regarding efficacy.

Abstract:

The heavy metal mercury is ubiquitously distributed in the environment resulting in permanent low-level exposure in human populations. Mercury can be encountered in three main chemical forms (elemental, inorganic, and organic) which can affect the immune system in different ways. In this review, we describe the effects of these various forms of mercury exposure on immune cells in humans and animals. In genetically susceptible mice or rats, subtoxic doses of mercury induce the production of highly specific autoantibodies as well as a generalized activation of the immune system. We review studies performed in this model and discuss their implications for the role of environmental chemicals in human autoimmunity.

Abstract
Based on in vitro studies and short-term in vivo studies, all mercurials were for a long time considered as prototypic immunosuppressive substances. Recent studies have confirmed that organic mercurials such as methyl mercury (MeHg) and ethyl mercury (EtHg) are much more potent immunosuppressors than inorganic mercury (Hg). However, Hg interacts with the immune system in the presence of a susceptible genotype to cause immunostimulation, antinucleolar antibodies targeting fibrillarin, and systemic immune-complex (IC) deposits, a syndrome called Hg-induced autoimmunity (HgIA). Recent studies in mice with a susceptible genotype has revealed that the immunosuppressive effect of MeHg and EtHg will within 1–3 weeks be superseded by immunostimulation causing an HgIA-like syndrome. At equimolar doses of Hg, MeHg has the weakest immunostimulating, autoimmunogen, and IC-inducing effect, while the effect of thimerosal is similar to that of inorganic mercury. The immunosuppression is caused by the organic mercurials per se. Since they undergo rapid transformation to inorganic Hg, studies are being undertaken to delineate the importance of the organic substances per se and the newly formed inorganic Hg for induction of autoimmunity.

Lipoic acid (LA) is an antioxidant that suppresses and treats an animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis. The purpose of this study was to determine the pharmacokinetics (PK), tolerability and effects on matrix metalloproteinase-9 (MMP-9) and soluble intercellular adhesion molecule-1 (sICAM-1) of oral LA in patients with MS. Thirty-seven MS subjects were randomly assigned to one of four groups: placebo, LA 600 mg twice a day, LA 1200 mg once a day and LA 1200 mg twice a day. Subjects took study capsules for 14 days. We found that subjects taking 1200 mg LA had substantially higher peak serum LA levels than those taking 600 mg and that peak levels varied considerably among subjects. We also found a significant negative correlation between peak serum LA levels and mean changes in serum MMP-9 levels (t=-0.263, P=0.04). There was a significant dose response relationship between LA and mean change in serum sICAM-1 levels (P=0.03). We conclude that oral LA is generally well tolerated and appears capable of reducing serum MMP-9 and sICAM-1 levels. LA may prove useful in treating MS by inhibiting MMP-9 activity and interfering with T-cell migration into the CNS.

Aims
Alpha-lipoic acid (LA) is a commonly used dietary supplement that exerts anti-oxidant and anti-inflammatory effects in vivo and in vitro. We investigated the mechanisms by which LA may confer protection in models of established atherosclerosis.

Main methods
Watanabe heritable hyperlipidemic (WHHL) rabbits were fed with high cholesterol chow for 6 weeks and then randomized to receive either high cholesterol diet alone or combined with LA (20 mg/kg/day) for 12 weeks. Vascular function was analyzed by myography. The effects of LA on T cell migration to chemokine gradients was assessed by Boyden chamber. NF-κB activation was determined by measuring translocation and electrophoresis migration shift assay (EMSA).

Key findings
LA decreased body weight by 15 ± 5% without alterations in lipid parameters. Magnetic Resonance Imaging (MRI) analysis demonstrated that LA reduced atherosclerotic plaques in the abdominal aorta, with morphological analysis revealing reduced lipid and inflammatory cell content. Consistent with its effect on atherosclerosis, LA improved vascular reactivity (decreased constriction to angiotensin II and increased relaxation to acetylcholine and insulin), inhibited NF-κB activation, and decreased oxidative stress and expression of key adhesion molecules in the vasculature. LA reduced T cell content in atherosclerotic plaque in conjunction with decreasing ICAM and CD62L (l-selectin) expression. These effects were confirmed by demonstration of a direct effect of LA in reducing T cell migration in response to CCL5 and SDF-1 and decreasing T cell adhesion to the endothelium by intra-vital microscopy.

Significance
The present findings offer a mechanistic insight into the therapeutic effects of LA on atherosclerosis.

Abstract
The anti-oxidant lipoic acid (LA) potently suppresses clinical and pathologic disease in the animal model of multiple sclerosis, experimental autoimmune encephalomyelitis, by inhibiting the migration of pathogenic T cells to the spinal cord. The mechanism by which this occurs is largely unknown. In this report we demonstrate that LA induces increases in cyclic AMP, a known immunosuppressant, in human T cells. The increase in cAMP is associated with increased adenylyl cyclase activity and is partially blocked by prostanoid receptor antagonists. We present evidence that LA also stimulates cAMP production in natural killer (NK) cells. This novel mechanism of action is highly relevant to the immunomodulatory effects of LA and provides further support for the study of LA as a therapeutic agent for multiple sclerosis and other autoimmune diseases.

Alpha-lipoic acid (LA), the metabolic antioxidant, was evaluated for its potential to protect against Cr⁶⁺-induced DNA damage. Potassium dichromate was administered to Swiss albino mice orally ad libitum at the doses of 5, 10 or 25 mg/kg body weight in drinking water to set DNA damage in cells, which was characterized in mouse peripheral blood mononuclear cells and bone marrow cells using single-cell gel electrophoresis and analyses of generated comets for Tail moment, Tail DNA and Tail length. DNA damage was dose dependent. Cytoprotection by LA was remarkable. LA (5, 10 and 25 mg/kg body weight intraperitoneally) in pre-, co- and post-toxicant administration schedule abrogated DNA damage substantially in both cell types. Protection by LA was also dose dependent. LA annulled DNA damage by Cr⁶⁺ in plasmid relaxation assay. A negligible DNA damage resulted during interaction of Cr⁶⁺ and LA. Compared to ascorbate, LA emerged as a better antioxidant and least DNA damaging. In conclusion, our study advocated an experimental therapeutic research potential in LA against Cr⁶⁺-induced DNA damage for reduction of occupational cancer risk in humans.

Abstract
The study investigates if alpha-lipoic acid is neuroprotective against chemotherapy induced neurotoxicity, if mitochondrial damage plays a critical role in toxic neurodegenerative cascade, and if neuroprotective effects of alpha-lipoic acid depend on mitochondria protection.
We used an in vitro model of chemotherapy induced peripheral neuropathy that closely mimic the in vivo condition by exposing primary cultures of dorsal root ganglion (DRG) sensory neurons to paclitaxel and cisplatin, two widely used and highly effective chemotherapeutic drugs. This approach allowed investigating the efficacy of alpha-lipoic acid in preventing axonal damage and apoptosis and the function and ultrastructural morphology of mitochondria after exposure to toxic agents and alpha-lipoic acid. Our results demonstrate that both cisplatin and paclitaxel cause early mitochondrial impairment with loss of membrane potential and induction of autophagic vacuoles in neurons. Alpha-lipoic acid exerts neuroprotective effects against chemotherapy induced neurotoxicity in sensory neurons: it rescues the mitochondrial toxicity and induces the expression of frataxin, an essential mitochondrial protein with anti-oxidant and chaperone properties. In conclusion mitochondrial toxicity is an early common event both in paclitaxel and cisplatin induced neurotoxicity. Alpha-lipoic acid protects sensory neurons through its anti-oxidant and mitochondrial regulatory functions, possibly inducing the expression of frataxin. These findings suggest that alpha-lipoic acid might reduce the risk of developing peripheral nerve toxicity in patients undergoing chemotherapy and encourage further confirmatory clinical trials.

a-Lipoic acid (α-LA) is a neuroprotective metabolic antioxidant that has been shown to cross the blood brain barrier. We tested whether a-LA is capable to prevent MOG35–55-induced experimental autoimmune encephalomyelitis (EAE), an established model of multiple sclerosis (MS). Daily oral administration of a-LA, starting at the time of immunization, significantly prevented EAE progression as compared to control mice. This was associated with a reduction of CNS infiltrating T cells and macrophages as well as decreased demyelination. We then tested a-LA in a therapeutic protocol aimed at suppressing EAE after its onset. Intraperitoneal (i.p.), but not oral, administration of a-LA significantly prevented disease progression when compared to vehicle-treated controls. Similarly, we observed significant reduction of demyelination and inflammatory infiltration. This clinical effect was not due to an impairment of MOG35–55 recognition by encephalitogenic T cells. In contrast, MOG-specific T cells showed a decreased production of IFNγ and IL-4, suggesting an immunosuppressive activity on both Th1 and Th2 cytokines. In addition, a-LA inhibited the proteolytic activity of MMP2 and MMP9 only at very high doses. Our data indicate that a-LA can effectively interfere with the autoimmune reaction associated with EAE through mechanisms other than its antioxidant activity and supports further studies on the use of a-LA as a potential therapy for MS.

α-Lipoic acid (LA) is a disulfide compound that is produced in small quantities in cells, and functions naturally as a co-enzyme in the pyruvate dehydrogenase and α-ketoglutarate dehydrogenase mitochondrial enzyme complexes. In pharmacological doses, LA is a multifunctional antioxidant. LA has been used in Germany for over 30 years for the treatment of diabetes-induced neuropathy. In patients with type 2 diabetes, recent studies have reported that intravenous (i.v.) infusion of LA increases insulin-mediated glucose disposal, whereas oral administration of LA has only marginal effects. If the limitations of oral therapy can be overcome, LA could emerge as a safe and effective adjunctive antidiabetic agent with insulin sensitizing activity.

The authors describe the long-term survival of a patient with pancreatic cancer without any toxic adverse effects. The treatment regimen includes the intravenous -lipoic acid and low-dose naltrexone (ALA-N) protocol and a healthy lifestyle program. The patient was told by a reputable university oncology center in October 2002 that there was little hope for his survival. Today, January 2006, however, he is back at work, free from symptoms, and without appreciable progression of his malignancy. The integrative protocol described in this article may have the possibility of extending the life of a patient who would be customarily considered to be terminal. The authors believe that life scientists will one day develop a cure for metastatic pancreatic cancer, perhaps via gene therapy or another biological platform. But until such protocols come to market, the ALA-N protocol should be studied and considered, given its lack of toxicity at levels reported. Several other patients are on this treatment protocol and appear to be doing well at this time.

The authors describe the long-term survival of a patient with pancreatic cancer without any toxic adverse effects. The treatment regimen includes the intravenous -lipoic acid and low-dose naltrexone (ALA-N) protocol and a healthy lifestyle program. The patient was told by a reputable university oncology center in October 2002 that there was little hope for his survival. Today, January 2006, however, he is back at work, free from symptoms, and without appreciable progression of his malignancy. The integrative protocol described in this article may have the possibility of extending the life of a patient who would be customarily considered to be terminal. The authors believe that life scientists will one day develop a cure for metastatic pancreatic cancer, perhaps via gene therapy or another biological platform. But until such protocols come to market, the ALA-N protocol should be studied and considered, given its lack of toxicity at levels reported. Several other patients are on this treatment protocol and appear to be doing well at this time.

Abstract
Reactive oxygen species are thought to be involved in a number of types of acute and chronic pathologic conditions in the brain and neural tissue. The metabolic antioxidant  a-lipoate (thioctic acid, 1, 2-dithiolane-3-pentanoic acid; 1, 2-dithiolane-3 valeric acid; and 6,8-dithiooctanoic acid) is a low molecular weight substance that is absorbed from the diet and crosses the blood–brain barrier.  a-Lipoate is taken up and reduced in cells and tissues to dihydrolipoate, which is also exported to the extracellular medium; hence, protection is afforded to both intracellular and extracellular environments. Both  a-lipoate and especially dihydrolipoate have been shown to be potent antioxidants, to regenerate through redox cycling other antioxidants like vitamin C and vitamin E, and to raise intracellular glutathione levels. Thus, it would seem an ideal substance in the treatment of oxidative brain and neural disorders involving free radical processes. Examination of current research reveals protective effects of these compounds in cerebral ischemia-reperfusion, excitotoxic amino acid brain injury, mitochondrial dysfunction, diabetes and diabetic neuropathy, inborn errors of metabolism, and other causes of acute or chronic damage to brain or neural tissue. Very few neuropharmacological intervention strategies are currently available for the treatment of stroke and numerous other brain disorders involving free radical injury. We propose that the various metabolic antioxidant properties of  a-lipoate relate to its possible therapeutic roles in a variety of brain and neuronal tissue pathologies: thiols are central to antioxidant defense in brain and other tissues. The most important thiol antioxidant, glutathione, cannot be directly administered, whereas  a-lipoic acid can. In vitro, animal, and preliminary human studies indicate that  a-lipoate may be effective in numerous neurodegenerative disorders.  

The antioxidant a-lipoic acid (LA) is a naturally occurring compound that has been shown to possess promising anticancer activity because of its ability to preferentially induce apoptosis and inhibit proliferation of cancer cells relative to normal cells. However, the molecular mechanisms underlying the apoptotic effect of LA are not well understood. We report here that LA induced reactive oxygen species (ROS) generation and a concomitant increase in apoptosis of human lung epithelial cancer H460 cells. Inhibition of ROS generation by ROS scavengers or by overexpression of antioxidant enzymes glutathione peroxidase and superoxide dismutase effectively inhibited LA-induced apoptosis, indicating the role of ROS, especially hydroperoxide and superoxide anion, in the apoptotic process. Apoptosis induced by LA was found to be mediated through the mitochondrial death pathway, which requires caspase-9 activation. Inhibition of caspase activity by the pan-caspase inhibitor (z-VAD-FMK) or caspase-9-specific inhibitor (z-LEHD-FMK) completely inhibited the apoptotic effect of LA. Likewise, the mitochondrial respiratory chain inhibitor rotenone potently inhibited the apoptotic and ROS-inducing effects of LA, supporting the role of mitochondrial ROS in LA-induced cell death. LA induced down-regulation of mitochondrial Bcl-2 protein through peroxide-dependent proteasomal degradation, and overexpression of the Bcl-2 protein prevented the apoptotic effect of LA. Together, our findings indicate a novel pro-oxidant role of LA in apoptosis induction and its regulation by Bcl-2, which may be exploited for the treatment of cancer and related apoptosis disorders.

Background and objectives: In spontaneously hypertensive rats (SHRs), excess endogenous aldehydes bind sulfhydryl groups of membrane proteins, altering membrane Ca²⁺ channels and increasing cytosolic free calcium and blood pressure. The thiol compound, N-acetyl cysteine, normalizes elevated blood pressure in SHRs by binding excess endogenous aldehydes and normalizing membrane Ca²⁺ channels and cytosolic free calcium. The aim of the present study was to investigate whether a dietary supplementation of an endogenous fatty acid, α-lipoic acid, another thiol compound that is known to increase tissue cysteine and glutathione, can lower blood pressure and normalize associated biochemical and histopathological changes in SHRs.

Methods and results: Starting at 12 weeks of age, animals were divided into three groups of six animals each. Animals in the Wistar-Kyoto (WKY) rat control group and the SHR control group were given a normal diet, and the SHR-lipoic acid group was given a diet supplemented with lipoic acid (500 mg/kg feed) for the next 9 weeks. After 9 weeks, systolic blood pressure, platelet [Ca²⁺]i, plasma insulin and liver, kidney and aortic aldehyde conjugates were significantly higher in SHR controls as compared with WKY rat controls and the SHR lipoic acid group. SHR controls also showed smooth muscle cell hyperplasia in the small arteries and arterioles of the kidneys.

Conclusions: Dietary α-lipoic acid supplementation in SHRs lowered the systolic blood pressure, cytosolic [Ca²⁺]i, blood glucose and insulin levels, and tissue aldehyde conjugates, and attenuated adverse renal vascular changes

ABSTRACT
Objective The aim of this study was to investigate the effect of alpha-lipoic acid (ALA) treatment on endothelium-dependent and -independent vasodilatation, assessed by forearm blood flow (FBF), in patients with type 2 diabetes mellitus.

Research design and methods A total of 30 subjects with type 2 diabetes were included in this randomized, controlled, double-blinded, parallel group study. FBF responses to intra-arterial acetylcholine (ACh) and glycerol trinitrate (GTN) were measured before and after 21 days of intravenous treatment with 600 mg alpha-lipoic acid or placebo.

Results FBF responses were comparable at baseline. After treatment, FBF reactivity to ACh and GTN was unchanged in subjects receiving placebo. By contrast, ALA treatment increased endothelium-dependent vasodilatation to ACh (P < 0·05) but not to GTN compared with baseline.

Conclusions Intravenous ALA treatment improves endothelium-dependent vasodilatation in patients with type 2 diabetes, in the absence of effects on forearm vasomotor function. If this salutary action translates into vascular risk reduction remains to be established.

Purpose

The purpose of this article is to review current evidence available for -lipoic acid (ALA) and its ability to improve symptoms of peripheral diabetic neuropathy (PDN).

Methods

This article searched MEDLINE from 1966 to November 2005 to identify clinical trials that supplemented ALA to individuals with type 1 or type 2 diabetes and positive sensory symptoms of PDN. Clinical trials to be included in this review met specific criteria of randomization, double masking, and placebo-controlled design.

Results

The search results produced 5 clinical trials that met the prerequisites for this review. ALA appears to improve neuropathic symptoms and deficits when administered via parenteral supplementation over a 3-week period. Oral treatment with ALA appears to have more conflicting data whether it improves sensory symptoms or just neuropathic deficits alone. An oral regimen of ALA and optimal length of treatment remains unclear. Both parenteral and up to a 2-year time period of oral supplementation of ALA appears to be safe without affecting glycemic control.

Conclusions

Based on these results, ALA should be considered as a treatment option for patients with PDN. When discussing supplementation with patients, it is important to discuss potential side effects; vitamin, mineral, and drug interactions; and current evidence available regarding efficacy.

Mitochondria produce reactive oxygen species that may contribute to vascular dysfunction. Alpha-lipoic acid and acetyl-L-carnitine reduce oxidative stress and improve mitochondrial function. In a double blind, crossover study, we examined the effects of combined alpha-lipoic acid /acetyl-L-carnitine treatment and placebo (eight weeks per treatment) on vasodilator function and blood pressure in 36 subjects with coronary artery disease. Active treatment increased brachial artery diameter by 2.3% (P=0.008), consistent with reduced arterial tone. Active treatment tended to decrease systolic blood pressure for the whole group (P=0.07) and had a significantly effect in the subgroup with blood pressure above the median (151±20 to 142±18 mmHg, P=0.03) and in the subgroup with the metabolic syndrome (139±21 to 130±18 mmHg, P=0.03). Thus, mitochondrial dysfunction may contribute to the regulation of blood pressure and vascular tone. Further studies are needed to confirm these findings and determine the clinical utility of alpha-lipoic acid/acetyl-L-carnitine as antihypertensive therapy.

Abstract

Aims: To determine the efficacy and safety of 600 mg of a-lipoic acid given i.v. over 3 weeks in diabetic patients with symptomatic polyneuropathy.
Methods: We searched the database of VIATRIS GmbH, Frankfurt, Germany, for clinical trials of
-lipoic acid according to the following prerequisites: randomized, double-masked, placebo-controlled, parallel-group trial using a-lipoic acid infusions of 600 mg i.v. per day for 3 Weeks, except for weekends, in diabetic patients with positive sensory symptoms of polyneuropathy which were scored by the Total Symptom Score (TSS) in the feet on a daily basis. Four trials (ALADIN I, ALADIN III, SYDNEY, NATHAN II) comprised n=1258 patients (a-lipoic acid: n=716; placebo: n=542) met these eligibility criteria and were included in a metaanalysis based on the intention-to-treat principle. Primary analysis involved a comparison of the differences in TSS from baseline to the end of i.v. treatment between the groups treated with a-lipoic acid or placebo. Secondary analyses included daily changes in TSS, responder rates (³50% improvement in TSS), individual TSS components, Neuropathy Impairment Score (NIS), NIS of the lower limbs (NIS-LL), individual NIS-LL components, and the rates of adverse events.
Results: After 3 weeks the relative difference in favour of a-lipoic acid vs placebo was 24.1 (13.5-33.4)% (geometric mean with 95% confidence interval) for TSS and 16.0 (5.7-25.2)% for NIS-LL. The responder rates were 52.7% in patients treated with a-lipoic acid and 36.9% in those on placebo (p<0.05). On a daily basis there was a continuous increase in the magnitude of TSS improvement in favour of a-lipoic acid vs placebo which was noted first after 8 days of treatment. Among the individual components of the TSS, pain, burning, and numbness decreased in favour of a-lipoic acid as compared with placebo, while among the NIS-LL components pin-prick and touch-pressure sensation as well as ankle reflexes were improved in favour of a-lipoic acid after 3 weeks. The rates of adverse events did not differ between the groups.
Conclusions: The results of this meta-analysis provide evidence that treatment with a-lipoic acid (600 mg/day i.v.) over 3 weeks is safe and significantly improves both neuropathic symptoms and deficits to a clinically meaningful degree in diabetic patients with symptomatic polyneuropathy.

The authors, in a previous article, described the long-term survival of a man with pancreatic cancer and metastases to the liver, treated with intravenous alpha-lipoic acid and oral low-dose naltrexone (ALA/N) without any adverse effects. He is alive and well 78 months after initial presentation. Three additional pancreatic cancer case studies are presented in this article. At the time of this writing, the first patient, GB, is alive and well 39 months after presenting with adenocarcinoma of the pancreas with metastases to the liver. The second patient, JK, who presented to the clinic with the same diagnosis was treated with the ALA/N protocol and after 5 months of therapy, PET scan demonstrated no evidence of disease. The third patient, RC, in addition to his pancreatic cancer with liver and retroperitoneal metastases, has a history of B-cell lymphoma and prostate adenocarcinoma. After 4 months of the ALA/N protocol his PET scan demonstrated no signs of cancer. In this article, the authors discuss the poly activity of ALA: as an agent that reduces oxidative stress, its ability to stabilize NF_kB, its ability to stimulate pro-oxidant apoptosic activity, and its discriminative ability to discourage the proliferation of malignant cells. In addition, the ability of lowdose naltrexone to modulate an endogenous immune response is discussed. This is the second article published on the ALA/N protocol and the authors believe the protocol warrants clinical trial.

The authors describe the long-term survival of a patient with pancreatic cancer without any toxic adverse effects. The treatment regimen includes the intravenous -lipoic acid and low-dose naltrexone (ALA-N) protocol and a healthy lifestyle program. The patient was told by a reputable university oncology center in October 2002 that there was little hope for his survival. Today, January 2006, however, he is back at work, free from symptoms, and without appreciable progression of his malignancy. The integrative protocol described in this article may have the possibility of extending the life of a patient who would be customarily considered to be terminal. The authors believe that life scientists will one day develop a cure for metastatic pancreatic cancer, perhaps via gene therapy or another biological platform. But until such protocols come to market, the ALA-N protocol should be studied and considered, given its lack of toxicity at levels reported. Several other patients are on this treatment protocol and appear to be doing well at this time.

Abstract
Glutathione is an abundant intracellular thiol antioxidant whose levels are reduced both in Parkinson's disease itself and in a widely used animal model of the disorder, systemic MPTP administration. Previous in vitro work from our laboratory has suggested that glutathione depletion may be directly responsible for mitochondrial dysfunction, which ultimately leads to dopaminergic cell death associated with the disease. Here, we demonstrate the ability of gamma-glutamylcysteine ethyl ester, a lipid permeable derivative of the major substrate for scavenger glutathione synthesis, to counteract glutathione loss and neurodegeneration associated with in vitro and in vivo administration of MPTP or its derivatives. This data suggests that prevention of glutathione depletion is a likely therapeutic target for the disease.

Abstract

Parkinson's disease (PD) is associated with loss of total glutathione (GSH) which may contribute to progressive cell death. Peripheral GSH administration has been used clinically with reported benefits. Despite this, there is little specific information to characterize its cellular uptake or clearance, brain elevation with peripheral delivery or neuroprotective efficacy in PD models. The current study was carried out to provide this information using in vitro and in vivo approaches. In rat mesencephalic culture, the monoethyl ester of GSH (GEE), but not GSH (1–10 mM, 24 h) produced a dose-dependent elevation in GSH. The half-life for clearance was 10.14 h and was not different in cells depleted of GSH prior to loading. Elevation of GSH with GEE protected neurons from oxidative stress with H2O2 or metabolic stress with the complex I and II inhibitors MPP⁺ and malonate, respectively. To determine if peripheral administration of GEE could elevate brain GSH levels, rats were administered 0.1–50 mg/kg/day GEE via osmotic minipump either subcutaneously (sc) or via a cannula placed into the left cerebral ventricle (icv) for 28 days. Only central delivery of GEE resulted in significant elevations of brain GSH. Elevation of brain GSH by icv infusion of GEE was examined for its neuroprotective effects against chronic central delivery of MPP^+. Infusion of 0.142 mg/kg/day MPP⁺ for 28 days caused a selective ipsilateral loss of striatal dopamine. Co-infusion of MPP⁺ with 10 mg/kg/day GEE significantly protected against striatal dopamine loss. These findings show that the ethyl ester of GSH but not GSH per se can elevate intracellular GSH, that brain elevation of GSH requires central delivery of the ethyl ester and that this elevation provides neuroprotection against oxidative stress or chronic mitochondrial impairment.

Abstract

Parkinson's disease (PD) is characterized by early glutathione depletion in the substantia nigra (SN). Among its various functions in the cell, glutathione acts as a substrate for the mitochondrial enzyme glutaredoxin 2 (Grx2). Grx2 is involved in glutathionylation of protein cysteine sulfhydryl residues in the mitochondria. Although monothiol glutathione–dependent oxidoreductases (Grxs) have previously been demonstrated to be involved in iron-sulfur (Fe-S) center biogenesis, including that in yeast, here we report data suggesting the involvement of mitochondrial Grx2, a dithiol Grx, in iron-sulfur biogenesis in a mammalian dopaminergic cell line. Given that mitochondrial dysfunction and increased cellular iron levels are two important hallmarks of PD, this suggests a novel potential mechanism by which glutathione depletion may affect these processes in dopaminergic neurons. We report that depletion of glutathione as substrate results in a dose-dependent Grx2 inhibition and decreased iron incorporation into a mitochondrial complex I (CI) and aconitase (m-aconitase). Mitochondrial Grx2 inhibition through siRNA results in a corresponding decrease in CI and m-aconitase activities. It also results in significant increases in iron-regulatory protein (IRP) binding, likely as a consequence of conversion of Fe-S–containing cellular aconitase to its non–Fe-S–containing IRP1 form. This is accompanied by increased transferrin receptor, decreased ferritin, and subsequent increases in mitochondrial iron levels. This suggests that glutathione depletion may affect important pathologic cellular events associated with PD through its effects on Grx2 activity and mitochondrial Fe-S biogenesis.

Introduction
Cadmium induces hypertension in animal models. Epidemiologic studies of cadmium exposure and hypertension, however, have been inconsistent.

Objective
We aimed to investigate the association of blood and urine cadmium with blood pressure levels and with the prevalence of hypertension in U.S. adults who participated in the 1999–2004 National Health and Nutrition Examination Survey (NHANES).

Methods
We studied participants ≥ 20 years of age with determinations of cadmium in blood (n = 10,991) and urine (n = 3,496). Blood and urine cadmium were measured by atomic absorption spectrometry and inductively coupled plasma–mass spectrometry, respectively. Systolic and diastolic blood pressure levels were measured using a standardized protocol.

Results
The geometric means of blood and urine cadmium were 3.77 nmol/L and 2.46 nmol/L, respectively. After multivariable adjustment, the average differences in systolic and diastolic blood pressure comparing participants in the 90th vs. 10th percentile of the blood cadmium distribution were 1.36 mmHg [95% confidence interval (CI), −0.28 to 3.00] and 1.68 mmHg (95% CI, 0.57–2.78), respectively. The corresponding differences were 2.35 mmHg and 3.27 mmHg among never smokers, 1.69 mmHg and 1.55 mmHg among former smokers, and 0.02 mmHg and 0.69 mmHg among current smokers. No association was observed for urine cadmium with blood pressure levels, or for blood and urine cadmium with the prevalence of hypertension.

Conclusions
Cadmium levels in blood, but not in urine, were associated with a modest elevation in blood pressure levels. The association was stronger among never smokers, intermediate among former smokers, and small or null among current smokers. Our findings add to the concern of renal and cardiovascular cadmium toxicity at chronic low levels of exposure in the general population.

The activity response of the antioxidant enzymes glutathione peroxidase (GPx), glutathione reductase (GR) and the contents of thiobarbituric reactive substances (TBARS) were investigated in rats exposed to lead. The enzyme activities were determined in the liver, kidney and heart of male and female rats which were received 100 mg and 1000 mg of lead acetate per liter water for 18 weeks. The statistical analyses indicated the differences related to the organs and to the sex of animals. Administration of lead evoked decrease of GPx activity in the kidney of both male and female rats. On the contrary, GPx activity increased in the heart of female rats, while in the male rats the higher dose of lead evoked a decrease in activity. In the kidneys of male rats and in the heart of female rats thiobarbituric acid reactive substances (TBARS), an indicators of oxidative stress, significantly increased in rats which were given the high lead dose. Most likely the observed changes could be a compensatory response to different lead accumulation in the male and female organs and also the possible distinct mechanisms in ROS elimination.

Abstract
Prenatal and early-life exposure to lead is hypothesized to have a range of adverse effects on childhood health. Drawing on data collected from a population-based prospective cohort study of a highly exposed town and a low exposed town in Kosovo, Yugoslavia we assessed whether elevated maternal blood lead (BPb) concentrations during pregnancy were associated with reduced childhood measures of attained height and BMI or growth rate, and whether the associations, if any, were mediated by maternal thyroid hormone concentration at mid-pregnancy. There was no association between blood lead levels and height or BMI in either town. However, increased maternal thyroid hormone was unexpectedly associated with reduced attained childhood height, and growth rate of height from 6.5 to 10 years, in the low-exposure town. We examine potential reasons for this unexpected inverse association.

Abstract
In order to investigate the toxic effects of lead during occupational exposure to this metal and the antidotal efficacy of ascorbic acid directed against these toxic effects, various artisans in Abeokuta, Nigeria, who have been shown to be occupationally exposed to lead were supplemented daily with 500 mg ascorbic acid for 2 weeks. Ca²+-Mg²+-ATPase activity in erythrocyte membrane, as well as calcium and magnesium concentrations in plasma, erythrocytes, erythrocyte membrane and urine of the artisans were determined before and after ascorbic acid supplementation. The 2-week ascorbic acid administration resulted in the reversal of lead-induced accumulation of calcium and magnesium in the erythrocyte membranes of the artisans. Ascorbic acid also reversed lead-induced inhibition of erythrocyte membrane Ca²+-Mg²+-ATPase. Urinary excretion of calcium and magnesium was not affected by ascorbic acid. There may be some scope in introducing ascorbic acid as an intervention strategy for the prevention and therapy of lead intoxication, especially in cases where the subjects cannot be removed from the source of lead exposure.

Background:
DNA methylation is an epigenetic mark which regulates gene expression and can be modified by environmental factors, possibly including toxic metals. Although their function is unclear, DNA contains large numbers of interdispersed repetitive elements (ALU and LINE-1) that are normally heavily methylated. Global methylation can be measured within these elements and changes in global methylation have been associated with diseases such as cancer and cardiovascular disease. Changes in global methylation may be representative of the effects of environmental factors on epigenetic marks and may explain observed phenomena such as programming and the latencies between exposure and disease onset.

Methods:
We measured global methylation on a subset of 783 Normative Aging Study subjects (all male) who had archived blood DNA samples. We measured patella and tibia lead levels by X-Ray fluorescence. Blood lead levels were measured by atomic absorption spectrometry. We determined global DNA methylation averages within CpG repeats of LINE-1 and ALU elements using PCR-Pyrosequencing on bisulfite-treated DNA. We constructed a series of multiple linear regression models using methylation with ALU or LINE-1 as the dependent variable and bone lead (tibia or patella in separate models) as the primary exposure markers. All models were adjusted for age at DNA collection, pack-years of smoking, education and blood Pb at time of DNA collection as covariates.

Results:
Overall mean (SD) values for global methylation as measured by ALU and LINE-1 were as follows: ALU-26.3% STD(1.1%); LINE-1- 76.8% STD(1.8%), respectively. Mean (SD) age was 72.9 (7.6) years. 32% of subjects had more than a high school education. Mean (SD) pack-years of smoking was 23.5 STD(26). In both the bivariate and full model patella lead levels were inversely associated with ALU (standardized Beta = -0.1; P = 0.03) but not LINE-1; standardized Beta = -0.04; P = 0.4). Results were unchanged if blood Pb was dropped from the model. Among the covariates only age was associated with global methylation (standardized Beta = -0.1; P = 0.01) Tibia lead and blood lead did not predict global methylation for either ALU or LINE-1.

Conclusion:
Patella lead levels inversely predict reduced global DNA methylation within ALU elements. We believe this is the first report in humans of an association between chronic lead exposure and DNA methylation. This finding may have implications for lead's mechanism of action in producing adverse health effects. Changes in DNA methylation could be a mechanism for long term programming effects as well. Further study is needed to confirm these findings and to determine whether DNA methylation marks (global and gene specific) are useful biomarkers of lead toxicity in epidemiologic studies.

Introduction:
The WHO Environmental Burden of Disease (EBD) methodology was used to assess burden of disease from lead exposure in Ireland. The aim was to produce a national baseline assessment and to evaluate whether intervention was required.

Methods:
The outcomes used for children were IQ loss and resulting rates of mild mental retardation (MMR), rates of anaemia, and gastrointestinal symptoms were calculated for children. For adults, raised blood pressure as an indicator for risk of cardiovascular disease was used. Mean blood lead levels from a survey of a rural population living beside an old mining site were used and assumed to be representative of urban exposures (Adults = 3.0μg/dL, n=341; pre-school children= 2.7μg/dL, n=84). Communities beside mining sites have been found to have similar levels of exposure to urban populations. Urban populations are assumed to have a greater proportion of their exposure from transport sources so estimates were constructed with and without the use of a correction factor to account for annual reductions since the ban on lead in gasoline in 2000. Assuming a normal distribution of the log-transformed means, the proportion of the population at each blood Pb interval was estimated, and rates of disease for each health outcome were mapped to each interval, based on the WHO dose-response estimates.

Results:
The attributable incidence rates of MMR in children was low (0.25/1000), as were rates of gastrointestinal symptoms (0.06/1000) and anaemia (0.04/1000). The Attributable Fractions for cerebrovascular and hypertensive disease in men was 1% and 0% for ischaemic heart disease and other heart disease in men. The Attributable Fraction for all cardiovascular outcomes in women was 0%.

Discussion & Conclusions:
The study population used is not representative of the Irish population. Populations adjacent to mining sites do not experience exposures comparable to those observed in communities beside other point sources, such as smelters. The survey population may be more representative of rural exposures, making the current assessment an underestimate. Analysis and comparison with similar urban and rural populations will be conducted to determine whether the current assessment should be assumed as a low, medium or high estimate. In countries with long-standing legislative controls on the use of lead, exposure of the general population will be low. Locally high levels due to point sources and exposure of children living in degraded housing are likely to be more important. Targeted surveillance of identified 'at risk' groups as recommended by the CDC in the US may be more practical for informing public health than the wider EBD assessment. The study highlighted the difficulty in conducting epidemiology in the absence of any biomonitoring in Ireland.

Abstract
Lead remains one of the most hazardous toxins in our environment. Because the toxic effects of lead are most prominent during early development, it is important to develop a suitable biomarker for lead exposure during the pre- and neonatal periods. In the present study, the spatial distribution of lead was measured in the enamel and dentine of ten human primary teeth using laser ablation-inductively coupled plasma-mass spectrometry. The neonatal line, visualized using confocal laser scanning microscopy, was used to demarcate the pre- and postnatal regions of the sample teeth. Lead levels in pre- and postnatally formed enamel and dentine were compared to blood-lead levels measured at birth and one year of age for four of these participants. Mean dentine-lead levels ranged from 0.17 ± 0.02 to 5.60 ± 1.79 μg/g, and mean enamel-lead levels ranged from 0.04 ± 0.01 to 1.47 ± 0.20 μg/g. The results of this preliminary study showed that the spatial distribution of lead in dentine reflected the blood-lead levels. The present study demonstrates a methodology where the spatial distribution of lead in the dentine of human primary teeth may be used to obtain temporal information of environmental lead exposure during the pre- and neonatal periods.

Abstract
The purpose of the study was to assess the neurocognitive status of 6-month-old infants whose mothers were exposed to low but varying amounts of lead during pregnancy. Lead levels in the cord blood were used to assess environmental exposure and the Fagan Test of Infant Intelligence (FTII) assessed visual recognition memory (VRM). The cohort consisted of 452 infants of mothers who gave birth to babies at 33–42 weeks of gestation between January 2001 and March 2003. The overall mean lead level in the cord blood was 1.42 μg/dl (95% CI: 1.35–1.48). We found that VRM scores in 6 month olds were inversely related to lead cord blood levels (Spearman correlation coefficient −0.16, p=0.007). The infants scored lower by 1.5 points with an increase by one unit (1 μg/dl) of lead concentration in cord blood. In the lower exposed infants (1.67 μg/dl) the mean Fagan score was 61.0 (95% CI: 60.3–61.7) and that in the higher exposed group (>1.67 μg/dl) was 58.4 (95% CI: 57.3–59.7). The difference of 2.5 points was significant at the p=0.0005 level. The estimated risk of scoring the high-risk group of developmental delay (FTII classification 3) due to higher lead blood levels was two-fold greater (OR=2.33, 95% CI: 1.32–4.11) than for lower lead blood levels after adjusting for potential confounders (gestational age, gender of the child and maternal education). As the risk of the deficit in VRM score (Fagan group 3) in exposed infants attributable to Pb prenatal exposure was about 50%, a large portion of cases with developmental delay could be prevented by reducing maternal blood lead level below 1.67 μg/dl. Although the negative predictive value of the chosen screening criterion (above 1.67 μg/dl) was relatively high (89%) its positive predictive value was too low (22%), so that the screening program based on the chosen cord blood lead criterion was recommended.

Abstract
Parameters of semen quality, seminal plasma indicators of secretory function of the prostate and seminal vesicles, sex hormones in serum, and biomarkers of lead, cadmium, copper, zinc, and selenium body burden were measured in 240 Croatian men 19–52 years of age. The subjects had no occupational exposure to metals and no known other reasons suspected of influencing male reproductive function or metal metabolism. After adjusting for age, smoking, alcohol, blood cadmium, and serum copper, zinc, and selenium by multiple regression, significant (P<0.05) associations of blood lead (BPb), δ-aminolevulinic acid dehydratase (ALAD), and/or erythrocyte protoporphyrin (EP) with reproductive parameters indicated a lead-related increase in immature sperm concentration, in percentages of pathologic sperm, wide sperm, round sperm, and short sperm, in serum levels of testosterone and estradiol, and a decrease in seminal plasma zinc and in serum prolactin. These reproductive effects were observed at low-level lead exposure (BPb median 49 μg/L, range 11–149 μg/L in the 240 subjects) common for general populations worldwide. The observed significant synergistic effect of BPb and blood cadmium on increasing serum testosterone, and additive effect of a decrease in serum selenium on increasing serum testosterone, may have implications on the initiation and development of prostate cancer because testosterone augments the progress of prostate cancer in its early stages.

OBJECTIVES. The purpose of this work was to assess the long-term impact of childhood lead exposure on the neurosubstrate of language function and brain organization.

METHODS. Young adults from the Cincinnati Lead Study were recruited to undergo functional magnetic resonance image scanning while performing a verb generation task. These subjects have been followed from birth through early childhood with extensive documentation of lead exposure, neuropsychology, and behavior. Forty-two subjects provided useful imaging data. The locale, strength, and the correlation between brain language activation and childhood blood lead concentration were studied.

RESULTS. After adjusting for potential confounders, the activation in left frontal cortex, adjacent to Broca's area, and left middle temporal gyrus, including Wernicke's area, were found to be significantly associated with diminished activation in subjects with higher mean childhood blood lead levels, whereas the compensatory activation in the right hemisphere homolog of Wernicke's area was enhanced in subjects with higher blood lead levels.

CONCLUSION. This study indicates that childhood lead exposure has a significant and persistent impact on brain reorganization associated with language function.

Objective:
Accumulating evidence suggests that nonoccupational exposures to lead may increase the risk for cardiovascular and neurologic outcomes such as hypertension and accelerated decline in cognition. Chronic low-level exposures, as measured by bone lead levels, are likely at least as important as acute exposures, as measured in blood lead. Elevated levels of plasma homocysteine (Hcy) are associated with cognitive decline and dementia, as well as cardiovascular disease.

Materials and Methods:
To examine lead's potential contribution to Hcy-mediated pathways in the development of these conditions, we evaluated bone and lead levels in association with plasma Hcy levels assessed up to 3 times over 6 years in a sample of 900 older men (mean age: 69 years) living in the Boston area. Analyses were adjusted for age, education, smoking, alcohol consumption, intake of vitamins B6 and B12, folate intake, and waist circumference.

Results:
Higher levels of lead independently predicted significantly higher levels of plasma Hcy. These findings held whether lead was measured in blood, cortical bone (tibia), or trabecular bone (patella). An interquartile range increment in blood lead (3 μg/dL) was associated with plasma Hcy levels that were 0.74 nmol/L higher (95% CI: 0.48-1.00; P<0.001). This increase in Hcy was similar to the increase in serum Hcy we observed for study participants who were about 9 years apart in age. Results pertaining to bone lead were similar; for example, an interquartile range in tibia lead (14 μg/dL) was associated with plasma Hcy levels that were 0.35 nmol/L higher (95% CI: 0.11-0.60; P = 0.005).

Conclusions:
The single previously published study of lead exposure and Hcy found a significant association with blood lead, but not bone lead. Using repeated measurements of Hcy, our results complement and expand these prior findings, suggesting that lead may exert its neuro- and vascular toxicity, both acutely and chronically, by elevating Hcy.

Background
A few recent studies have demonstrated heightened hypothalamic–pituitary–adrenal (HPA) axis reactivity to acute stress in animals exposed to heavy metal contaminants, particularly lead. However, Pb-induced dysregulation of the HPA axis has not yet been studied in humans.

Objective
In this study, we examined children’s cortisol response to acute stress (the glucocorticoid product of HPA activation) in relation to low-level prenatal and postnatal Pb exposure.

Methods
Children’s prenatal blood Pb levels were determined from cord blood specimens, and postnatal lead levels were abstracted from pediatrician and state records. Children’s adrenocortical responses to an acute stressor were measured using assays of salivary cortisol before and after administration of a standard cold pressor task.

Results
Pb exposure was not associated with initial salivary cortisol levels. After an acute stressor, however, increasing prenatal and postnatal blood Pb levels were independently associated with significantly heightened salivary cortisol responses.

Conclusions
Our results suggest that relatively low prenatal and postnatal blood lead levels—notably those below the 10 μg/dL blood lead level identified by the Centers for Disease Control and Prevention for public health purposes—can alter children’s adrenocortical responses to acute stress. The behavioral and health consequences of this Pb-induced HPA dysregulation in children have yet to be determined.

Background
Several epidemiologic studies have suggested an association between Parkinson’s disease (PD) and exposure to heavy metals using subjective exposure measurements.

Objectives
We investigated the association between objective chronic occupational lead exposure and the risk of PD.

Methods
We enrolled 121 PD patients and 414 age-, sex-, and race-, frequency-matched controls in a case–control study. As an indicator of chronic Pb exposure, we measured concentrations of tibial and calcaneal bone Pb stores using 109Cadmium excited K-series X-ray fluorescence. As an indicator of recent exposure, we measured blood Pb concentration. We collected occupational data on participants from 18 years of age until the age at enrollment, and an industrial hygienist determined the duration and intensity of environmental Pb exposure. We employed physiologically based pharmacokinetic modeling to combine these data, and we estimated whole-body lifetime Pb exposures for each individual. Logistic regression analysis produced estimates of PD risk by quartile of lifetime Pb exposure.

Results
Risk of PD was elevated by > 2-fold [odds ratio = 2.27 (95% confidence interval, 1.13–4.55); p = 0.021] for individuals in the highest quartile for lifetime lead exposure relative to the lowest quartile, adjusting for age, sex, race, smoking history, and coffee and alcohol consumption. The associated risk of PD for the second and third quartiles were elevated but not statistically significant at the α = 0.05 level.

Conclusions
These results provide an objective measure of chronic Pb exposure and confirm our earlier findings that occupational exposure to Pb is a risk factor for PD.

Background

Outdoor air pollution and lead exposure can disturb cardiac autonomic function, but the effects of both these exposures together have not been studied.

Methods

We examined whether higher cumulative lead exposures, as measured by bone lead, modified cross-sectional associations between air pollution and heart rate variability among 384 elderly men from the Normative Aging Study. We used linear regression, controlling for clinical, demographic, and environmental covariates.

Results

We found graded, significant reductions in both high-frequency and low-frequency powers of heart rate variability in relation to ozone and sulfate across the quartiles of tibia lead. Interquartile range increases in ozone and sulfate were associated respectively, with 38% decrease (95% confidence interval = -54.6% to -14.9%) and 22% decrease (-40.4% to 1.6%) in high frequency, and 38% decrease (-51.9% to -20.4%) and 12% decrease (-28.6% to 9.3%) in low frequency, in the highest quartile of tibia lead after controlling for potential confounders. We observed similar but weaker effect modification by tibia lead adjusted for education and cumulative traffic (residuals of the regression of tibia lead on education and cumulative traffic). Patella lead modified only the ozone effect on heart rate variability.

Conclusions

People with long-term exposure to higher levels of lead may be more sensitive to cardiac autonomic dysfunction on high air pollution days. Efforts to understand how environmental exposures affect the health of an aging population should consider both current levels of pollution and history of lead exposure as susceptibility factors.

Lead is a confirmed neurotoxin, but questions remain about lead-associated intellectual deficits at blood lead levels < 10 μg/dL and whether lower exposures are, for a given change in exposure, associated with greater deficits. The objective of this study was to examine the association of intelligence test scores and blood lead concentration, especially for children who had maximal measured blood lead levels < 10 μg/dL. We examined data collected from 1,333 children who participated in seven international population-based longitudinal cohort studies, followed from birth or infancy until 5–10 years of age. The full-scale IQ score was the primary outcome measure. The geometric mean blood lead concentration of the children peaked at 17.8 μg/dL and declined to 9.4 μg/dL by 5–7 years of age; 244 (18%) children had a maximal blood lead concentration < 10 μg/dL, and 103 (8%) had a maximal blood lead concentration < 7.5 μg/dL. After adjustment for covariates, we found an inverse relationship between blood lead concentration and IQ score. Using a log-linear model, we found a 6.9 IQ point decrement [95% confidence interval (CI), 4.2–9.4] associated with an increase in concurrent blood lead levels from 2.4 to 30 μg/dL. The estimated IQ point decrements associated with an increase in blood lead from 2.4 to 10 μg/dL, 10 to 20 μg/dL, and 20 to 30 μg/dL were 3.9 (95% CI, 2.4–5.3), 1.9 (95% CI, 1.2–2.6), and 1.1 (95% CI, 0.7–1.5), respectively. For a given increase in blood lead, the lead-associated intellectual decrement for children with a maximal blood lead level < 7.5 μg/dL was significantly greater than that observed for those with a maximal blood lead level ≥7.5 μg/dL (p = 0.015). We conclude that environmental lead exposure in children who have maximal blood lead levels < 7.5 μg/dL is associated with intellectual deficits.

Abstract

Breast cancer (BC) is linked to estrogen exposure. Estradiol (E₂) stimulates BC cells proliferation by binding the estrogen receptor (ER). Hormone-related cancers have been linked to estrogenic environmental contaminants. Cadmium (Cd) a toxic pollutant, acts as estrogens in BC cells. Purpose of our study was to evaluate whether Cd regulates MCF-7 cell proliferation by activating ERK1/2, Akt and PDGFRα kinases. Cd increased cell proliferation and the ER-antagonist ICI 182,780 blunted it. To characterize an ER-dependent mechanism, ERα/β expression was evaluated. Cd decreased ERα expression, but not ERβ. Cd also increased ERK1/2, Akt and PDGFRα phosphorylation while ICI blocked it. Since stimulation of phosphorylation was slower than expected, c-fos and c-jun proto-oncogenes, and PDGFA were analyzed. Cd rapidly increased c-jun, c-fos and PDGFA expression. Cells were also co-incubated with the Cd and specific kinases inhibitors, which blocked the Cd-stimulated proliferation.

In conclusion, our results indicate that Cd increases BC cell proliferation in vitro by stimulating Akt, ERK1/2 and PDGFRα kinases activity likely by activating c-fos, c-jun and PDGFA by an ERα-dependent mechanism.

Abstract

Oxygen-free radicals, more generally known as reactive oxygen species (ROS) along with reactive nitrogen species (RNS) are well recognised for playing a dual role as both deleterious and beneficial species. The “two-faced” character of ROS is substantiated by growing body of evidence that ROS within cells act as secondary messengers in intracellular signalling cascades, which induce and maintain the oncogenic phenotype of cancer cells, however, ROS can also induce cellular senescence and apoptosis and can therefore function as anti-tumourigenic species. The cumulative production of ROS/RNS through either endogenous or exogenous insults is termed oxidative stress and is common for many types of cancer cell that are linked with altered redox regulation of cellular signalling pathways. Oxidative stress induces a cellular redox imbalance which has been found to be present in various cancer cells compared with normal cells; the redox imbalance thus may be related to oncogenic stimulation. DNA mutation is a critical step in carcinogenesis and elevated levels of oxidative DNA lesions (8-OH-G) have been noted in various tumours, strongly implicating such damage in the etiology of cancer. It appears that the DNA damage is predominantly linked with the initiation process. This review examines the evidence for involvement of the oxidative stress in the carcinogenesis process. Attention is focused on structural, chemical and biochemical aspects of free radicals, the endogenous and exogenous sources of their generation, the metal (iron, copper, chromium, cobalt, vanadium, cadmium, arsenic, nickel)-mediated formation of free radicals (e.g. Fenton chemistry), the DNA damage (both mitochondrial and nuclear), the damage to lipids and proteins by free radicals, the phenomenon of oxidative stress, cancer and the redox environment of a cell, the mechanisms of carcinogenesis and the role of signalling cascades by ROS; in particular, ROS activation of AP-1 (activator protein) and NF-κB (nuclear factor kappa B) signal transduction pathways, which in turn lead to the transcription of genes involved in cell growth regulatory pathways. The role of enzymatic (superoxide dismutase (Cu, Zn-SOD, Mn-SOD), catalase, glutathione peroxidase) and non-enzymatic antioxidants (Vitamin C, Vitamin E, carotenoids, thiol antioxidants (glutathione, thioredoxin and lipoic acid), flavonoids, selenium and others) in the process of carcinogenesis as well as the antioxidant interactions with various regulatory factors, including Ref-1, NF-κB, AP-1 are also reviewed.

OBJECTIVES: High levels of transition metals such as iron, nickel, chromium, copper, and lead are closely related to free radical generation, lipid peroxidation, formation of DNA strand breaks, and tumor growth in cellular systems. In order to determine the correlation to malignant growth in humans, we investigated the accumulation of heavy metals in 20 breast cancer biopsies and compared the findings to the levels found in 8 healthy biopsies. METHODS: The concentration of transition metals in breast cancer and control biopsies was assessed by a standardized Atomic Absorption Spectrofotometry technique with acidic hydrolysis for sample preparation. Additionally, heavy metal analysis in control biopsies was also performed with an Inductive Coupled Plasma--Mass Spectroscopy technique. For statistical analysis of the results, the Mann-Whitney U Test was applied. RESULTS: A highly significant accumulation of iron (p<0.0001), nickel (p<0.00005), chromium (p<0.00005), zinc (p<0.00001), cadmium (p<0.005), mercury (p<0.005), and lead (p< 0.05) was found in the cancer samples when compared to the control group. Copper and silver showed no significant differences to the control group, whereas tin, gold, and palladium were not detectable in any biopsies.
CONCLUSIONS: The data suggest that pathological accumulation of transition metals in breast tissue may be closely related to the malignant growth proess.

Soon after the exciting discovery of a method to transform human skin cells into stem cells in 2007 came the frustration of actually trying to make a sufficient amount of these induced pluripotent stem (iPS) cells.* The process is so inefficient that scientists typically only get 0.01 percent of a sample of human skin, or fibroblast, cells to form iPS cell colonies after they infect fibroblasts with the retroviruses used to induce pluripotency. "We almost gave up three years ago," says Dr. Duanqing Pei, director general and professor at the Guangzhou Institutes of Biomedicine and Health in Guangzhou, China.

But Pei's group at the Chinese Academy of Sciences plugged away and now has found that a simple chemical can give iPS cell transformation a big boost. By adding vitamin C to the medium in which human skin cells are grown, the researchers managed to turn 1 to 2 percent, compared to 0.01 percent, of cells into iPS cell colonies. "Once you reach the single digit frequency, that is no longer an infrequent event," Pei says. This yield, he believes, could allow scientists to finally study what is happening inside the cells as they undergo transformation. The results were published December 24 in Cell Stem Cell.

The ultimate goal is to make iPS cells a valid therapeutic option by replacing the potentially dangerous retroviruses with a safer cocktail of proteins and chemicals, including vitamin C.

The path that Pei's group took to identifying the beneficial role of vitamin C started with the realization that the factors that induce cells to become pluripotent were causing the cells to make the free radicals known as reactive oxygen species (ROS). "A high level of ROS is definitely very bad for the fibroblasts," Pei says, because it induces cell death at a faster rate.

To enhance the survival of cells and their likelihood of becoming iPS cells, Pei's team tested a variety of chemicals with anti-oxidant properties. The researchers started with fibroblast cells from mouse embryos, which have been shown to revert to iPS cells at a higher frequency than human fibroblasts. First, they infected the cells with retroviruses that trigger the expression of four embryonic cell-specific genes in the cells. Then they let the cells grow, either with or without vitamin C.

Ten days later, when cells typically begin to be reprogrammed into iPS cells, Pei's group found that 30 percent more mouse cells were alive in the Petri dish that contained vitamin C than in the one that did not, suggesting that the vitamin helps keep cells alive. One possible mechanism to explain this improved survival is that the cells exposed to ascorbic acid had lower levels of a tumor suppressor protein called p53, which can elicit cell death.

Surprisingly, the researchers found that vitamin C not only helps cells survive, but it enhances their progression to pluripotency by a factor of 100 . After 14 days, when cells start to become fully pluripotent, 10 to 20 percent of the mouse cells that were grown with vitamin C expressed genes associated with pluripotency compared with only 0.1 to 0.2 percent of the colonies grown without vitamin C. The group saw a similar improvement in human fibroblast reprogramming, from 0.01 percent in the absence of vitamin C to 1 percent in the presence. When other anti-oxidants were tested, none boosted the development of pluripotency.

Pei believes that ascorbic acid is spurring the induction of pluripotency in mouse and human cells through both its anti-oxidant properties as well as an as-yet unknown mechanism. Too much ROS and the reprogramming "machine" won't start, he says. But once ROS is reduced, the machine starts, and vitamin C makes it run more smoothly. "If you have too much ROS, the whole [reprogramming] machine will not move, but then once you [reduce] ROS, I think vitamin C does something [else] to make the machine move more smoothly," he says.

"Overall I think this is quite impressive progress," says Kwang-Soo Kim, director of the Molecular Neurobiology Lab at Harvard Medical School. Kim has developed a system to improve the safety of iPS cells by delivering the four proteins that induce pluripotency directly into cells. Because it avoids retroviruses, which integrate their genomes into cell chromosomes, his system carries less risk of potentially cancer causing mutations. But the efficiency is low—one to 10 percent of the viral method—and it's much slower. "We need a different kind of approach," he says.
This approach could be adding the four pluripotency-inducing proteins to cells to jumpstart the reprogramming "machine" and then improving the efficiency with a combination of chemicals, including vitamin C. Pei is currently trying to optimize the medium in which cells are grown. Although he doubts that any other anti-oxidant will have the same effect as ascorbic acid, Pei thinks that certain growth factors could further improve the culture conditions. In fact, his group found that combining vitamin C with valproic acid, which helps induce pluripotency, can improve transformation efficiency of human fibroblasts from 1 to 6 percent.

This level of efficiency could be enough to advance studies with iPS cells. "We don't need to generate 50 percent of the cells…as long as we can reproducibly generate a sufficient number of iPS lines," Kim says, adding that a 1 percent transformation efficiency could be enough.

Eventually, researchers would have to differentiate the iPS cells into certain cell types, says Kim, who himself has differentiated the more controversial embryonic stem cells into neurons to try to treat Parkinson's disease.

But, first, several studies with these vitamin C-induced pluripotent cells should be done, Kim notes. One possible problem – vitamin C causes cells to express lower levels of p53, which is important for the repair of DNA damage. Although Pei's group did not find any chromosomal abnormalities in cells grown with vitamin C, Kim says that higher resolution analysis is needed to ensure there are no mutations.

Because of the relatively high yield of Pei's method, these analyses and other studies of iPS cells should be possible. Now researchers might be able to generate enough cells to study the mechanism of and improve the safety and efficacy of iPS cells. "It's a worldwide effort to boost efficiency and make this more practical for much wider participation from the scientific community," Pei says.

* Note (12/29/09): This sentence was edited after publication to correct the year of the first human iPS cells.

Abstract

Cardiovascular disease is the leading cause of mortality worldwide. Arsenic is a ubiquitous metalloid in the crust of the earth. Chronic arsenic poisoning is becoming an emerging epidemic in Asia. Epidemiological studies have shown that chronic arsenic poisoning through ingestion of arsenic-contaminated water is associated with various cardiovascular diseases in dose–response relationships. These cardiovascular disorders include carotid atherosclerosis detected by ultrasonography, impaired microcirculation, prolonged QT interval and increased QT dispersion in electrocardiography, and clinical outcomes such as hypertension, blackfoot disease (a unique peripheral vascular disease endemic in southwestern Taiwan), coronary artery disease and cerebral infarction. Chronic arsenic poisoning is an independent risk factor for cardiovascular disease. The adverse cardiovascular effects of long-term arsenic exposure may be persistent and/or irreversible. Arsenic-induced cardiovascular diseases in human population may result from the interaction among genetic, environment and nutritional factors. The major adverse cardiovascular effect of chronic arsenic poisoning has been established qualitatively and quantitatively in the high arsenic exposure areas, but the low-dose effect of arsenic on cardiovascular diseases remains to be explored. Cardiovascular death is the major cause of mortality worldwide, and a small increased risk may imply a large quantity of excess mortality.

U.S. minority infants are born carrying hundreds of chemicals in their bodies, according to a report released today by an environmental group.

The Environmental Working Group's study commissioned five laboratories to examine the umbilical cord blood of 10 babies of African-American, Hispanic and Asian heritage and found more than 200 chemicals in each newborn.

"We know the developing fetus is one of the most vulnerable populations, if not the most vulnerable, to environmental exposure," said Anila Jacobs, EWG senior scientist. "Their organ systems aren't mature and their detox methods are not in place, so cord blood gives us a good picture of exposure during this most vulnerable time of life."

Of particular concern to Jacobs: 21 newly detected contaminants, including the controversial plastics additive bisphenol A, or BPA, which mimics estrogen and has been shown to cause developmental problems and precancerous growth in animals. Last month, researchers reported that male Chinese factory workers exposed to high levels of the chemical experienced erectile dysfunction and other sexual problems.

"BPA is a really important finding because people are really aware about its potential toxicity," Jacobs told reporters. "This is the first study to find BPA in umbilical cord blood, and it correlates with national data on it."

Jacobs said the study focused on minority children to show that chemical exposure is ubiquitous, building on 2005 research on cord blood from 10 anonymous babies. That study found a similar body burden among the babies. This is the first study to look at chemicals in minority newborns.

"Minority groups may have increased exposure to certain chemicals, but here we didn't focus on those chemicals," Jacobs said. "The sample size is too small to see major differences, but we want to increase awareness about chemical exposures."

Leo Trasande, co-director of the Children's Environmental Health Center at the Mount Sinai School of Medicine, said the findings, while preliminary, show that minority communities are often disproportionately affected by chemical exposure. Trasande was not involved in the EWG study.

"Presently, minority communities suffer from a host of chronic disorders, and disproportionate chemical exposures may contribute significantly to the origins of the disparities that exist," Trasande said.

Both he and Jacobs said the findings add momentum for the call to revamp the Toxic Substances Control Act, or TSCA, the law regulating the more than 80,000 chemicals on its database. They released the report on the same day that a Senate panel is scheduled to discuss the government's strategy for managing the tens of thousands of chemicals in the marketplace with an eye toward overhauling TSCA.

TSCA does not require most chemicals to be tested for safety before they are approved for widespread use. Because of this, Trasande said, less than half of the 3,000 high-production volume chemicals on the marketplace have toxicity data, and less than one-fifth have toxicity testing data on the effects on developing organs.

"These results are alarming for their implications of health impacts on children," Trasande said.

Another challenge facing chemical regulators is understanding how the different chemicals interact together, which is particularly significant given the number of chemicals found in people.

Objectives. We investigated whether foreign birthplace and residence were associated with an increased risk of childhood lead poisoning.

Methods. We conducted a matched case–control study among New York City children (mean age=3 years) tested for lead poisoning in 2002 (n=203 pairs). Children were matched on age, date of test, and residential area. Blood lead and housing data were supplemented by a telephone survey administered to parents or guardians. Conditional logistic regression analysis was used to examine the relationship of lead poisoning status to foreign birthplace and time elapsed since most recent foreign residence after adjustment for housing and behavioral risk factors.

Results. Both foreign birthplace and time since most recent foreign residence had strong adjusted associations with lead poisoning status, with children who had lived in a foreign country less than 6 months before their blood test showing a particularly elevated risk of lead poisoning relative to US-born children with no foreign residential history before their blood test (odds ratio [OR]=10.9; 95% confidence interval [CI]=3.3, 36.5).

Conclusions. Our findings demonstrate an increased risk of lead poisoning among immigrant children.

Persons employed in high-risk lead-related occupations can transport lead dust home from a worksite through clothing, shoes, tools, or vehicles (1-4). During 2008, the Maine Childhood Lead Poisoning Prevention Program (MCLPPP) identified 55 new cases of elevated (≥15 µg/dL) venous blood lead levels (BLLs) among children aged <6 years through mandated routine screening (5,6). Although 90% of childhood lead poisoning cases in Maine during 2003--2007 had been linked to lead hazards in the child's home, no lead-based paint or dust or water with elevated lead levels were found inside the homes associated with six of the 2008 cases (i.e., five families, including one family with two affected siblings). An expanded environmental investigation determined that these six children were exposed to lead dust in the family vehicles and in child safety seats. The sources of the lead dust were likely household contacts who worked in high-risk lead exposure occupations. Current recommendations for identifying and reducing risk from take-home lead poisoning include 1) ensuring that children with elevated BLLs are identified through targeted blood lead testing, 2) directing prevention activities to at-risk workers and employers, and 3) improving employer safety protocols. State and federal prevention programs also should consider, when appropriate, expanded environmental lead dust testing to include vehicles and child safety seats.

Lead poisoning has decreased among children in the United States because of federal, state, and community efforts to reduce exposure (7). Federal bans on leaded gasoline and lead-based paint, and improvements in occupational safety and health standards* have helped mitigate exposure to lead, especially among children. MCLPPP responds to all reported elevated blood lead levels ≥10 µg/dL. Children with venous BLLs ≥15µg/dL automatically trigger an environmental investigation to determine the lead sources, and children are monitored until their venous BLLs are <10µg/dL.

For this study, a case of lead poisoning was defined by a confirmed venous BLL ≥15 µg/dL in a child aged <6 years living in Maine. All cases were identified through mandated blood lead testing for children at ages 1 year and 2 years following CDC targeted lead testing recommendations (5,6).† A case of take-home lead poisoning was defined by 1) a confirmed venous BLL ≥15 µg/dL among children aged <6 years living in Maine, 2) a household contact in a high-risk lead-related occupation, and 3) environmental lead dust sampling of vehicle and child safety seat ≥40 µg/ft2, with no detectable lead-based paint hazards present in the home.

When these investigations began, MCLPPP contacted each child's family and offered general lead education, nursing case management, and environmental lead investigations by licensed lead risk assessors to determine the likely sources of the poisoning. Families were interviewed using a MCLPPP risk-assessment questionnaire to determine other possible exposures. Radiograph fluorescence analysis was used to determine whether lead-based paint was in the homes. Lead dust wipe samples were taken using the Environmental Protection Agency (EPA) standard lead dust loading methodology in the homes.§ For the cases described in this report, MCLPPP also directed investigators to perform additional dust sampling in the family vehicles and child safety seats because household members had occupations at high risk for lead exposure. The EPA acceptable lead dust standard is <40 µg/ft2 for floors inside the home, but no lead standards have been set for vehicles or child safety seats.

The six children with take-home lead poisoning, including two siblings in one family, ranged in age from 4 to 28 months, and had a median venous BLL of 21 µg/dL (range: 15--32 µg/dL). Among the five families, contacts included four persons who currently or recently worked in painting and paint removal, and one who was a self-employed metals recycler. The workers reported no lead-related occupational safety measures provided by their employers at work sites.

Four of the five homes were built after 1978, the year lead-based paint was banned. No lead-based paint was detected by radiograph fluorescence analysis inside the five homes. In two of five homes, lead dust was detected in exterior areas where family members removed and kept work clothes, including an entryway/deck (110 µg/ft2), another entryway (1,200 µg/ft2), and a laundry room (40 µg/ft2). Five family vehicles (one family did not own a vehicle and one family had two) tested positive for lead dust with a median of 550 µg/ft2 for driver/passenger seats (range: 49--2,100 µg/ft2) and a median of 1,570 µg/ft2 for driver/passenger floors (range: 240--2,900 µg/ft2). All child safety seats (n = 6) tested positive for lead dust with a median of 98 µg/ft2 (range: 43--420 µg/ft2). Three safety seats were stored in the vehicle (median lead dust: 120 µg/ft2 [range: 43--420 µg/ft2]); the other three were removed and kept in the home when not in use (median lead dust: 95 µg/ft2 [range: 50--100 µg/ft2]).

MCLPPP determined that the primary source of lead exposure was lead dust in the family vehicles and on the child safety seats (Table), and provided recommendations to prevent continued exposure. Persons who are exposed to lead at work or through hobbies are advised upon finishing the workday to 1) place lead-contaminated clothes, including shoes and personal protective equipment, in a closed container for laundering or cleaning; 2) take a shower and wash hands, face, and hair when exposed above the permissible exposure limits; 3) change into street clothes; and 4) wash work clothes separately from all other clothes.** However, parents and household contacts reported a lack of facilities available for washing, showering, and changing clothes before entering their personal vehicles. MCLPPP also recommended thorough vacuuming and wet cleaning of the vehicle interiors and replacement of any child safety seat that tested positive for lead dust. Families were referred to the Maine Injury Prevention Program for replacement safety seats, if needed.

Abstract

Perinatal exposure to cadmium (Cd) or methylmercury (MeHg) results in impaired neurodevelopment. Thyroid hormone is essential for normal brain development. However, the issue whether Cd or MeHg, especially at low doses, interrupts thyroid hormone action remains to be investigated. In the present study, effects of perinatal exposure to low levels of Cd or MeHg on thyroid hormone metabolism were examined using metallothionein I and II (MT-I/II) null or wild-type neonatal mice. Dams were exposed to 10 mg/L water of Cd or 5 mg/kg chow of MeHg from gestational day 0 to post-natal day 10 (PND 10). Sera, livers and brains were collected from neonates on PND 10. Iodothyronine deiodinase activities and serum thyroxine (T4) concentrations were measured. MeHg exposure failed to induce changes in serum T4 levels and liver type 1 deiodinase (D1) and brain type 2 deiodinase (D2) activities regardless of the MT genotype. However, exposure to MeHg resulted in a decrease in brain type 3 deiodinase (D3) activity in MT-I/II null and wild-type neonates. In contrast, exposure to Cd resulted in a decrease in serum T4 levels in MT-I/II null neonates. Consistently, brain D2 activity was increased in Cd-exposed MT-I/II null neonates. No significant changes in liver D1 and brain D3 activities were induced by Cd administration. Our study demonstrates that perinatal exposure to low doses of Cd or MeHg can induce changes in brain deiodinase activities in the neonates, suggesting that thyroid hormone metabolism in fetuses and neonates might be a potential target of Cd and MeHg.

Abstract
Chemical exposure can trigger or accelerate the development of autoimmune manifestations. Although heavy metals are elementary chemical structures, they can have profound and complex effects on the immune system. In genetically susceptible mice or rats, administration of subtoxic doses of mercury induces both the production of highly specific autoantibodies and a polyclonal activation of the immune system. We review in this article some of the mechanisms by which heavy metal exposure can lead to autoimmunity.

Abstract
This study evaluated the relationship between pregnancy rate and semen cadmium concentration. This prospective and nonrandomized clinical study analyzed 341 male partners of infertile couples undergoing infertility evaluation and management. Semen samples were collected to analyze semen quality and cadmium concentrations. The main outcome was pregnancy during 60-day infertility treatment. Simple linear regression analysis revealed an association between semen cadmium concentration NS sperm count (r = −0.150, P = 0.0416) in nonsmoking subjects (n = 184). In both smokers and nonsmokers, semen cadmium concentrations were significantly higher in non-pregnant patients than in pregnant patients. In nonsmokers, Cox multi-variable fertility ratio analysis demonstrated an association between semen cadmium concentration and fertility (fertility ratio of log semen cadmium = 0.24; 95% confidence intervals (CI) = 0.12–0.47, P < 0.0001) after adjusting for related variables. Each tenfold increase in semen cadmium concentration was associated with a 4.17-fold increase in infertility ratio in nonsmoking patients. In smokers, Cox multi-variable fertility ratio analysis demonstrated that sperm count and semen cadmium concentration are associated with fertility (fertility ratio of log semen cadmium = 0.17; 95% CI = 0.04–0.63, P = 0.0085) after adjusting for related variables. In smokers, each tenfold increase in semen cadmium concentration was associated with a 5.88-fold increase in infertility ratio. In conclusion, low levels of cadmium accumulation in semen may contribute to male infertility by reducing sperm quality.

BACKGROUND: It has been hypothesized that exposure to exogenous estrogens may be associated with endometriosis and uterine myomas. We sought to investigate the association between heavy metals which have been shown to be hormonally active and these disorders using data from the National Health and Nutrition Examination Survey, 1999–2002.

METHODS: Women aged 20–49 years who had data on metals and the outcomes of interest, were premenopausal and neither pregnant nor breastfeeding were eligible (n = 1425). Lead, cadmium and mercury were measured in whole blood. Diagnosis of outcomes was based upon self-report. Logistic regression was used to examine the association between tertiles of heavy metals and disease adjusting for age, race/ethnicity, use of birth control pills prior to diagnosis and smoking status at diagnosis.

RESULTS: A dose–response association between cadmium and endometriosis was observed [tertile 2 versus 1: adjusted odds ratio (OR) = 1.94, 95% confidence interval (CI): 0.73–5.18; tertile 3 versus 1: adjusted OR = 3.39, 95% CI 1.37–8.40]. This association persisted in subanalyses: (i) limiting analysis to women diagnosed in the past 10 years and (ii) limiting analysis to women diagnosed since last pregnancy, although limited by sample size.

CONCLUSIONS: These results must be interpreted with caution given the cross-sectional study design. The observed association between cadmium and endometriosis deserves further investigation in properly designed studies.

Objective
This systematic review evaluates the evidence on the association between lead exposure and cardiovascular end points in human populations.

Methods
We reviewed all observational studies from database searches and citations regarding lead and cardiovascular end points.

Results
A positive association of lead exposure with blood pressure has been identified in numerous studies in different settings, including prospective studies and in relatively homogeneous socioeconomic status groups. Several studies have identified a dose–response relationship. Although the magnitude of this association is modest, it may be underestimated by measurement error. The hypertensive effects of lead have been confirmed in experimental models. Beyond hypertension, studies in general populations have identified a positive association of lead exposure with clinical cardiovascular outcomes (cardiovascular, coronary heart disease, and stroke mortality; and peripheral arterial disease), but the number of studies is small. In some studies these associations were observed at blood lead levels < 5 μg/dL.

Conclusions
We conclude that the evidence is sufficient to infer a causal relationship of lead exposure with hypertension. We conclude that the evidence is suggestive but not sufficient to infer a causal relationship of lead exposure with clinical cardiovascular outcomes. There is also suggestive but insufficient evidence to infer a causal relationship of lead exposure with heart rate variability.

Public Health Implications
These findings have immediate public health implications. Current occupational safety standards for blood lead must be lowered and a criterion for screening elevated lead exposure needs to be established in adults. Risk assessment and economic analyses of lead exposure impact must include the cardiovascular effects of lead. Finally, regulatory and public health interventions must be developed and implemented to further prevent and reduce lead exposure.

Abstract

Epstein-Barr virus (EBV) hepatitis is an uncommon, almost always self-limited disease in immunocompetent patients. Accurate diagnosis is imperative for appropriate clinical management. The aim of this study was to compare 3 available methods for EBV detection on routinely processed liver biopsies to determine their effectiveness in aiding the diagnosis. In 6 of the 8 cases of EBV hepatitis, EBV was detected by both polymerase chain reaction (PCR) for EBV DNA and in situ hybridization (ISH) for EBV early RNA (EBER). EBV was detected by PCR only in 1 case, and by ISH only in another. EBER-positive cells detected by ISH were typically few and individually distributed in the portal tracts and sinusoids. Immunohistochemical staining for EBV latent membrane proteins was negative in all 8 cases. Five cases of chronic hepatitis C used as negative controls were negative by all 3 detection methods for EBV. These data indicate that PCR and ISH are equally sensitive in detecting EBV in routinely processed liver biopsies. The ready implementation of ISH in pathology laboratories makes it a useful ancillary tool in confirming the diagnosis of EBV hepatitis in equivocal cases. However, EBER-positive cells can be sparse and easily overlooked. Immunohistochemistry for EBV latent membrane proteins apparently has no utility in the diagnosis of EBV hepatitis.

Abstract
As the pathogenesis of fibromyalgia continues to raise debate, multiple putative triggers have been implicated. The current review summarizes the available data linking fibromyalgia to either infection or vaccination. Multiple infectious agents have been associated with the development of either full-blown fibromyalgia (e.g. hepatits C), or with symptom complexes extensively overlapping with that syndrome (e.g. chronic Lyme disease). The cases of Lyme disease, mycoplasma, hepatits C and HIV are detailed. Despite the described associations, no evidence is available demonstrating the utility of antibiotic or anti-viral treatment in the management of fibromyalgia. Possible mechanistic links between fibromyalgia and HIV are reviewed. Associations have been described between various vaccinations and symptom complexes including fibromyalgia and chronic fatigue syndrome. The case of Gulf War syndrome, a functional multisystem entity sharing many clinical characteristics with fibromyalgia is discussed, with emphasis on the possibility of association with administration of multiple vaccinations during deployment in the Persian Gulf and the interaction with stress and trauma. Based on this example a model is proposed, wherein vaccinations function as co-triggers for the development of functional disorders including fibromyalgia, in conjunction with additional contributing factors.

Objective

To describe a case of bilateral acute retinal necrosis syndrome (ARNS) in a 5-year-old boy.

Method

A retrospective, interventional case is described in one child attending the pediatric ophthalmology section, complaining of sudden bilateral red eye and haze-impaired vision. A standardized ophthalmologic examination and specific serological probes supported the diagnosis of severe bilateral ARNS in an immunocompetent child.

Results

The reduced visual acuity (<20/400), the ocular fundus signs (perivasculitis, thrombosis and retinal edema) and the positive immunoglobulin M anti-Epstein Barr virus serology, lead us to the ARNS definitive diagnosis. Antiviral therapy (Acyclovir; Zovirax®), ciclopentolate dilating eye drops, and antiplatelet treatment (acetil salicylic acid; Aspirin®) were administered until recovering the final visual acuity (20/40).

Conclusions

The ARNS is an ocular disease with poor prognosis, which in turns may display better course when determining the etiopathogenic virus and selecting the appropriate and precocious therapy.

The objective of this study was to assess the incidence and the clinical significance of Epstein-Barr virus (EBV) in patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Patients with CLL/SLL who presented at The University of Texas M. D. Anderson Cancer Center over a 2-year period and had available marrow paraffin blocks were studied for evidence of EBV infection using a highly specific in-situ hybridization assay for detection of EBV encoded RNA (EBERs). Results were analysed in relation to other presenting characteristics and outcome. Thirty-two patients were examined. EBERs were detected in the bone marrow of 12 of 32 (38%) CLL/SLL marrows vs 0 of 20 normal marrows (p = 0.002). EBERs were observed in sporadic granulocytes alone or in addition to its presence in lymphocytes in nine of the 12 EBV-positive patients. EBERs were detected less frequently in patients with Rai stage 0 – 1 disease (20%) compared with Rai stage 2 – 4 (66%; p = 0.008). EBER-positive patients tended to have higher lactate dehydrogenase levels (p = 0.053). The 10-year survival rate was 22% vs 58% for patients with and without discernible EBERs (log-rank, p = 0.08). Evidence of EBV infection was found in 38% of patients with CLL/SLL. Despite the small number of patients tested, discernable EBERs were significantly more common in individuals with more advanced Rai stage and there was a trend toward shorter survival in patients in whom EBV EBERs were discerned. Larger studies are needed to determine the prognostic value and role of EBV infection in patients with CLL/SLL.

Introduction
Epstein-Barr virus (EBV) is present in over 90% of the world's population. This infection is considered benign, even though in limited cases EBV is associated with infectious and neoplastic conditions. Over the past decade, the EBV association with breast cancer has been constantly debated. Adding to this clinical and biological uncertainty, different techniques gave contradictory results for the presence of EBV in breast carcinoma specimens. In this study, minor groove binding (MGB)-TaqMan real time PCR was used to detect the presence of EBV DNA in both peripheral blood and tumor samples of selected patients.

Methods
Peripheral blood and breast carcinoma specimens from 24 patients were collected. DNA was extracted and then amplified by MGB-TaqMan real time PCR.

Results
Of 24 breast tumor specimens, 11 (46%) were positive for EBV DNA. Of these 11 breast tumor specimens, 7 (64%) were also positive for EBV DNA in the peripheral blood, while 4 (36%) were positive for EBV DNA in the tumor, but negative in the blood.

Conclusion
EBV was found at extremely low levels, with a mean of 0.00004 EBV genomes per cell (range 0.00014 to 0.00001 EBV genomes per cell). Furthermore, our finding of the presence of EBV in the tumor specimens coupled to the absence of detection of EBV genomic DNA in the peripheral blood is consistent with the epithelial nature of the virus. Because of the low levels of viral DNA in tumor tissue, further studies are needed to assess the biological input of EBV in breast cancer.

Most people are quite aware of the fact that vitamin supplements are a great idea to support the overall health and wellbeing of children and young adolescents. However, one of the vitamins that is sometimes overlooked is Vitamin D, a vitamin that is essential for bone health and may offer additional protection against childhood coughs and colds.

Children should be able to get all the Vitamin D they need from exposure to sunlight, but the lifestyle of many of today’s children and teens means that they simply do not spend enough time outside to gain the maximum benefits.

A new study recently published has revealed that levels of Vitamin D found amongst US children have indeed now fallen below what is considered medically acceptable, and that the situation amongst African American and Hispanic children is particularly dire.

The latest research was conducted by Jonathan Mansbach, MD and his team who are based at Children’s Hospital Boston. They used data culled from the National Health and Nutrition Examination Survey which encompasses medical data about approximately 5,000 children from across the United States and was collected between 2001-2006.

Taking the current recommendation from the American Academy of Pediatrics that children and teens maintain a 50 nmol/L level of Vitamin D in their system to be considered healthy the researchers found that approximately 20% of US children will fall below this guideline score and in the case of Hispanic children that figure rises to an astonishing 82%. The outlook is even worse for non Hispanic black children as the research suggests that 92% suffer from Vitamin D deficiency.

There are those who disagree with the APA guidelines, saying that other research in adults has suggested that 75 nmol/L is a more reasonable level to ensure good health. Should this eventually turn out to be the case then the picture is even grimmer. Says lead author of the study Mansbach “If 75 nmol/L or higher is eventually demonstrated to be the healthy normal level of vitamin D, then there is much more vitamin D deficiency in the U.S. than people realize”

The researchers conclude their report by recommending that all children and teens take a Vitamin D supplement on a daily basis to ensure that their bodies have enough Vitamin D to maintain healthy growth. It is especially crucial they note for those who live in high altitudes where sunlight is scarce in winter.

Background. In Western countries, the cause of 60% of all Guillain‐Barre syndrome (GBS) cases remains unidentified. The number of cases of unidentified cause peaks in winter, and these cases are commonly preceded by respiratory tract infection or influenza‐like illness. We investigated the triggering role of influenza virus infection.

Methods. Of 405 patients with GBS who were admitted to a French reference center during 1996–2004, 234 had cases caused by an unidentified agent. We used time‐series methods to study the correlation between the monthly incidence of such cases and influenza‐like illnesses reported by the Sentinelles surveillance network. We analyzed anti‐influenza antibodies using complement fixation testing and hemagglutination‐inhibition assays. We studied etiological subgroups using Wilcoxon and Fisher’s exact tests.

Results. We found a positive association between the monthly incidence of GBS caused by an unidentified agent and reported influenza‐like illnesses. Of 73 patients whose cases occurred during periods in which there was a possible link to influenza, 10 (13.7%) had serological evidence of recent influenza A, and 4 (5.5%) had serological evidence of influenza B. Eight of 10 influenza A–related cases occurred during “major” influenza seasons, and antibodies specific to the current epidemic strain were found in 9 cases. Most patients with influenza A–related cases were aged <65 years, and none had antiganglioside antibodies. Influenza‐related cases differed both from Campylobacter jejuni–related cases, with regard to the lack of need for mechanical ventilation ( P = .0,14), and from the cases caused by an unidentified agent, with regard to the presence of preceding influenza‐like illness or respiratory tract infection ( P = .0,15) and longer time from the infectious event to GBS onset (P = .0,4 ).

Conclusions. Influenza viruses are infrequent triggering agents of GBS but may play a significant role during major influenza outbreaks. Influenza‐related GBS displays specific features and is not associated with antiganglioside antibody response, which suggests the presence of underlying immune mechanisms.

Context  An unexplained increase in the risk of Guillain-Barre syndrome (GBS) occurred among recipients of the swine influenza vaccine in 1976-1977. Guillain-Barre syndrome remains the most frequent neurological condition reported after influenza vaccination to the Vaccine Adverse Events Reporting System (VAERS) since its inception in 1990.

Objective  To evaluate trends of reports to VAERS of GBS following influenza vaccination in adults.

Design, Setting, and Participants  VAERS is the US national spontaneous reporting system for adverse events following vaccination. Reports of GBS in persons 18 years or older following influenza vaccination were evaluated for each influenza season from July 1, 1990, through June 30, 2003. The number of people vaccinated was estimated from the National Health Interview Survey and US census data. Beginning in 1994, active follow-up was conducted to verify GBS diagnosis and obtain other clinical details.

Main Outcome Measure  Reporting rates of GBS following influenza vaccination over time.

Results  From July 1990 through June 2003, VAERS received 501 reports of GBS following influenza vaccination in adults. The median onset interval (13 days) was longer than that of non-GBS reports of adverse events after influenza vaccine (1 day) (P<.001). The annual reporting rate decreased 4-fold from a high of 0.17 per 100  000 vaccinees in 1993-1994 to 0.04 in 2002-2003 (P<.001). A GBS diagnosis was confirmed in 82% of reports. Preceding illness within 4 weeks of vaccination was identified in 24% of reported cases.

Conclusions  From 1990 to 2003, VAERS reporting rates of GBS after influenza vaccination decreased. The long onset interval and low prevalence of other preexisting illnesses are consistent with a possible causal association between GBS and influenza vaccine. These findings require additional research, which can lead to a fuller understanding of the causes of GBS and its possible relationship with influenza vaccine.

Abstract

Where direct experimental research into a causal hypothesis of a disease is impossible due to ethical and practical considerations, epidemiological inference is the accepted route to establishing cause. Therefore, to examine the autism as mercury poisoning hypothesis, this paper reviews the existing scientific literature within the context of established epidemiological criteria and finds that the evidence for a causal relationship is compelling. Exposure to mercury (via vaccines and maternal dental amalgam) in utero and during infant years is confirmed; mercury poisoning is known to cause symptoms consistent with autism; animal modeling supports the link and, critically, mercury levels are higher in both the urine and blood of autistic children than in non-autistic peers. Analogous to epidemiological evidence of the smoking–lung cancer relationship, a mercury–autism relationship is confirmed. The precautionary principle demands that health professionals not take an action if there is suspicion that the action may cause severe or lifelong health effects: it does not require certainty. Therefore, given the severity, devastating lifelong impact and extremely high prevalence of autism, it would be negligent to continue to expose pregnant and nursing mothers and infant children to any amount of avoidable mercury.

Abstract

Mercury compounds versatility explains their numerous applications in diverse areas of industry. The growing use of this metal has resulted in a significant increase of environment contamination and episodes of human intoxication, arousing the concern of international organisms. Meanwhile, consequences of these intoxication outbreaks are still not fully understood, especially if we consider long-term effects of chronic exposure to relatively low levels of mercury compounds. In the present manuscript, studies about the genotoxicity of mercury compounds, performed in vitro, in vivo, and/or including epidemiologic studies of human populations were reviewed. Some mercury compounds are known as teratogenic agents, especially affecting the normal development of the central nervous system; however, the connection between mercury exposure and carcinogenesis remains controversial. Since 1990s, epidemiological studies have begun to include an increasing number of human subjects, making the results more reliable: thus, increased genotoxicity was demonstrated in human populations exposed to mercury through diet, occupation or by carrying dental fillings. In fact, concentrations of methylmercury causing significant genotoxic alterations in vitro below both safety limit and concentration were associated with delayed psychomotor development with minimal signs of methylmercury poisoning. Based on mercury's known ability to bind sulfhydryl groups, several hypotheses were raised about potential molecular mechanisms for the metal genotoxicity. Mercury may be involved in four main processes that lead to genotoxicity: generation of free radicals and oxidative stress, action on microtubules, influence on DNA repair mechanisms and direct interaction with DNA molecules. All data reviewed here contributed to a better knowledge of the widespread concern about the safety limits of mercury exposure.

Abstract

In 1981, R. Edgar Hope-Simpson proposed that a ‘seasonal stimulus’ intimately associated with solar radiation explained the remarkable seasonality of epidemic influenza. Solar radiation triggers robust seasonal vitamin D production in the skin; vitamin D deficiency is common in the winter, and activated vitamin D, 1,25(OH)2D, a steroid hormone, has profound effects on human immunity. 1,25(OH)2D acts as an immune system modulator, preventing excessive expression of inflammatory cytokines and increasing the ‘oxidative burst’ potential of macrophages. Perhaps most importantly, it dramatically stimulates the expression of potent anti-microbial peptides, which exist in neutrophils, monocytes, natural killer cells, and in epithelial cells lining the respiratory tract where they play a major role in protecting the lung from infection. Volunteers inoculated with live attenuated influenza virus are more likely to develop fever and serological evidence of an immune response in the winter. Vitamin D deficiency predisposes children to respiratory infections. Ultraviolet radiation (either from artificial sources or from sunlight) reduces the incidence of viral respiratory infections, as does cod liver oil (which contains vitamin D). An interventional study showed that vitamin D reduces the incidence of respiratory infections in children. We conclude that vitamin D, or lack of it, may be Hope-Simpson's ‘seasonal stimulus’.

Background — Vitamin D receptors have a broad tissue distribution that includes vascular smooth muscle, endothelium, and cardiomyocytes. A growing body of evidence suggests that vitamin D deficiency may adversely affect the cardiovascular system, but data from longitudinal studies are lacking.

Methods and Results — We studied 1739 Framingham Offspring Study participants (mean age 59 years; 55% women; all white) without prior cardiovascular disease. Vitamin D status was assessed by measuring 25-dihydroxyvitamin D (25-OH D) levels. Prespecified thresholds were used to characterize varying degrees of 25-OH D deficiency (<15 ng/mL, <10 ng/mL). Multivariable Cox regression models were adjusted for conventional risk factors. Overall, 28% of individuals had levels <15 ng/mL, and 9% had levels <10 ng/mL. During a mean follow-up of 5.4 years, 120 individuals developed a first cardiovascular event. Individuals with 25-OH D <15 ng/mL had a multivariable-adjusted hazard ratio of 1.62 (95% confidence interval 1.11 to 2.36, P=0.01) for incident cardiovascular events compared with those with 25-OH D 15 ng/mL. This effect was evident in participants with hypertension (hazard ratio 2.13, 95% confidence interval 1.30 to 3.48) but not in those without hypertension (hazard ratio 1.04, 95% confidence interval 0.55 to 1.96). There was a graded increase in cardiovascular risk across categories of 25-OH D, with multivariable-adjusted hazard ratios of 1.53 (95% confidence interval 1.00 to 2.36) for levels 10 to <15 ng/mL and 1.80 (95% confidence interval 1.05 to 3.08) for levels <10 ng/mL (P for linear trend=0.01). Further adjustment for C-reactive protein, physical activity, or vitamin use did not affect the findings.

Conclusions — Vitamin D deficiency is associated with incident cardiovascular disease. Further clinical and experimental studies may be warranted to determine whether correction of vitamin D deficiency could contribute to the prevention of cardiovascular disease.

Vitamin D status differs by latitude and race, with residents of the northeastern United States and individuals with more skin pigmentation being at increased risk of deficiency. A PubMed database search yielded 63 observational studies of vitamin D status in relation to cancer risk, including 30 of colon, 13 of breast, 26 of prostate, and 7 of ovarian cancer, and several that assessed the association of vitamin D receptor genotype with cancer risk.

The majority of studies found a protective relationship between sufficient vitamin D status and lower risk of cancer. The evidence suggests that efforts to improve vitamin D status, for example by vitamin D supplementation, could reduce cancer incidence and mortality at low cost, with few or no adverse effects.

In innate immune responses, activation of Toll-like receptors (TLRs) triggers direct antimicrobial activity against intracellular bacteria, which in murine, but not human, monocytes and macrophages is mediated principally by nitric oxide. We report here that TLR activation of human macrophages up-regulated expression of the vitamin D receptor and the vitamin D-1–hydroxylase genes, leading to induction of the antimicrobial peptide cathelicidin and killing of intracellular Mycobacterium tuberculosis. We also observed that sera from African-American individuals, known to have increased susceptibility to tuberculosis, had low 25-hydroxyvitamin D and were inefficient in supporting cathelicidin messenger RNA induction. These data support a link between TLRs and vitamin D–mediated innate immunity and suggest that differences in ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection.

Abstract
The first health effects of cadmium (Cd) were reported already in 1858. Respiratory and gastrointestinal symptoms occurred among persons using Cd-containing polishing agent. The first experimental toxicological studies are from 1919. Bone effects and proteinuria in humans were reported in the 1940's. After World War II, a bone disease with fractures and severe pain, the itai-itai disease, a form of Cd-induced renal osteomalacia, was identified in Japan. Subsequently, the toxicokinetics and toxicodynamics of Cd were described including its binding to the protein metallothionein. International warnings of health risks from Cd-pollution were issued in the 1970's. Reproductive and carcinogenic effects were studied at an early stage, but a quantitative assessment of these effects in humans is still subject to considerable uncertainty. The World Health Organization in its International Program on Chemical Safety, WHO/IPCS (1992) (Cadmium. Environmental Health Criteria Document 134, IPCS. WHO, Geneva, 1–280.) identified renal dysfunction as the critical effect and a crude quantitative evaluation was presented. In the 1990's and 2000 several epidemiological studies have reported adverse health effects, sometimes at low environmental exposures to Cd, in population groups in Japan, China, Europe and USA (reviewed in other contributions to the present volume). The early identification of an important role of metallothionein in cadmium toxicology formed the basis for recent studies using biomarkers of susceptibility to development of Cd-related renal dysfunction such as gene expression of metallothionein in peripheral lymphocytes and autoantibodies against metallothionein in blood plasma. Findings in these studies indicate that very low exposure levels to cadmium may give rise to renal dysfunction among sensitive subgroups of human populations such as persons with diabetes.

Background
Periodontal disease is a complex, multifactorial, chronic inflammatory disease that involves degradation of periodontal structures, including alveolar bone. Cadmium adversely affects bone remodeling, and it is therefore possible that environmental Cd exposure may be a risk factor for periodontal-disease–related bone loss.

Abstract
There is accumulating evidence that the metabolism of several trace elements is altered in diabetes mellitus and that these nutrients might have specific roles in the pathogenesis and progress of this disease. The aim of present study was to compare the level of toxic elements, lead (Pb), cadmium (Cd), and arsenic (As) in biological samples (whole blood, urine, and scalp hair) of patients having diabetes mellitus type-2 age ranged (31–60) (n = 238), with those of age matched non-diabetics (ND) as control subjects (n = 196), of both genders.

The concentrations of elements were measured by means of an atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy was checked by conventional wet acid digestion method and using certified reference materials. The overall recoveries of all elements were found in the range of 98.1–99.4% of certified values.

The results of this study showed that the mean values of Pb, Cd and, As were significantly higher in scalp hair samples of smoker and non-smoker diabetic patients as compared to control subjects (p < 0.001). The concentration of understudy toxic metals was also high in blood and urine samples of DM patient but difference was more significant in smoker DM patients. These results are consistent with those obtained in other studies, confirming that toxic metals may play a role in the development of diabetes mellitus.

Abstract
Cadmium is a toxic metal occurring in the environment naturally and as a pollutant emanating from industrial and agricultural sources. Food is the main source of cadmium intake in the non-smoking population. The bioavailability, retention and toxicity are affected by several factors including nutritional status such as low iron status. Cadmium is efficiently retained in the kidney (half-time 10–30 years) and the concentration is proportional to that in urine (U-Cd). Cadmium is nephrotoxic, initially causing kidney tubular damage. Cadmium can also cause bone damage, either via a direct effect on bone tissue or indirectly as a result of renal dysfunction. After prolonged and/or high exposure the tubular injury may progress to glomerular damage with decreased glomerular filtration rate, and eventually to renal failure. Furthermore, recent data also suggest increased cancer risks and increased mortality in environmentally exposed populations. Dose–response assessment using a variety of early markers of kidney damage has identified U-Cd points of departure for early kidney effects between 0.5 and 3 μg Cd/g creatinine, similar to the points of departure for effects on bone. It can be anticipated that a considerable proportion of the non-smoking adult population has urinary cadmium concentrations of 0.5 μg/g creatinine or higher in non-exposed areas. For smokers this proportion is considerably higher. This implies no margin of safety between the point of departure and the exposure levels in the general population. Therefore, measures should be put in place to reduce exposure to a minimum, and the tolerably daily intake should be set in accordance with recent findings.

Objectives
Indigenous people of the Torres Strait (Australia) have greater potential for cadmium exposure and renal damage than other Australians due to high cadmium in some traditional seafood and a high prevalence of Type 2 diabetes, hypertension, smoking, and obesity. This study explored associations between albuminuria and an index of cadmium exposure (urinary cadmium excretion) in the presence and absence of Type 2 diabetes.

Research design and methods
Two population-based, cross-sectional studies were undertaken in the Torres Strait to obtain data on body mass index (BMI), blood pressure, chronic disease, smoking, urinary cadmium, and albumin creatinine ratio (ACR).

Results
Age- and BMI-adjusted urinary cadmium levels were significantly higher (p<0.01) among people with diabetes and albuminuria (n=22, geometric mean (GM) 1.91 μg Cd/g creatinine) compared to those with diabetes and normal ACR (n=21, GM 0.74 μg Cd/g creatinine). Urinary cadmium was also strongly associated (p<0.001) with ACR among people with diabetes in regression models and remained significant after controlling for age, sex, BMI, smoking status, and hypertension (or continuous systolic and diastolic measurements).

Conclusions
While the study has methodological limitations and the nature of the association is unclear, the striking dose-dependent links between markers of cadmium exposure and of Type 2 diabetic nephropathy highlight the need for further definitive research on the health effects of cadmium in the presence of diabetes.

Abstract
Recent epidemiological studies suggest a positive association between exposure to the environmental pollutant cadmium (Cd) and the incidence and severity of diabetes. In this review, we examine the literature suggesting a relationship between Cd exposure, elevated blood glucose levels, and the development of diabetes. In addition we review human and animal studies indicating that Cd potentiates or exacerbates diabetic nephropathy. We also review the various possible cellular mechanisms by which Cd may alter blood glucose levels. In addition, we present some novel findings from our own laboratories showing that Cd elevates fasting blood glucose levels in an animal model of subchronic Cd exposure before overt signs of renal dysfunction are evident. These studies also show that Cd reduces insulin levels and has direct cytotoxic effects on the pancreas. Together, these findings indicate that Cd may be a factor in the development of some types of diabetes and they raise the possibility that Cd and diabetes-related hyperglycemia may act synergistically to damage the kidney.

Background
Exposure to arsenic concentrations in drinking water in excess of 300 μg/L is associated with diseases of the circulatory and respiratory system, several types of cancer, and diabetes; however, little is known about the health consequences of exposure to low-to-moderate levels of arsenic (10–100 μg/L).

Methods
A standardized mortality ratio (SMR) analysis was conducted in a contiguous six county study area of southeastern Michigan to investigate the relationship between moderate arsenic levels and twenty-three selected disease outcomes. Disease outcomes included several types of cancer, diseases of the circulatory and respiratory system, diabetes mellitus, and kidney and liver diseases. Arsenic data were compiled from 9251 well water samples tested by the Michigan Department of Environmental Quality from 1983 through 2002. Michigan Resident Death Files data were amassed for 1979 through 1997 and sex-specific SMR analyses were conducted with indirect adjustment for age and race; 99% confidence intervals (CI) were reported.

Results
The six county study area had a population-weighted mean arsenic concentration of 11.00 μg/L and a population-weighted median of 7.58 μg/L. SMR analyses were conducted for the entire six county study area, for only Genesee County (the most populous and urban county), and for the five counties besides Genesee. Concordance of results across analyses is used to interpret the findings. Elevated mortality rates were observed for both males (M) and females (F) for all diseases of the circulatory system (M SMR, 1.11; CI, 1.09–1.13; F SMR, 1.15; CI, 1.13,-1.17), cerebrovascular diseases (M SMR, 1.19; CI, 1.14–1.25; F SMR, 1.19; CI, 1.15–1.23), diabetes mellitus (M SMR, 1.28; CI, 1.18–1.37; F SMR, 1.27; CI, 1.19–1.35), and kidney diseases (M SMR, 1.28; CI, 1.15–1.42; F SMR, 1.38; CI, 1.25–1.52).

Conclusion
This is some of the first evidence to suggest that exposure to low-to-moderate levels of arsenic in drinking water may be associated with several of the leading causes of mortality, although further epidemiologic studies are required to confirm the results suggested by this ecologic SMR analysis.

Context  High chronic exposure to inorganic arsenic in drinking water has been related to diabetes development, but the effect of exposure to low to moderate levels of inorganic arsenic on diabetes risk is unknown. In contrast, arsenobetaine, an organic arsenic compound derived from seafood intake, is considered nontoxic.

Objective  To investigate the association of arsenic exposure, as measured in urine, with the prevalence of type 2 diabetes in a representative sample of US adults.

Design, Setting, and Participants  Cross-sectional study in 788 adults aged 20 years or older who participated in the 2003-2004 National Health and Nutrition Examination Survey (NHANES) and had urine arsenic determinations.

Main Outcome Measure  Prevalence of type 2 diabetes across intake of arsenic.

Results  The median urine levels of total arsenic, dimethylarsinate, and arsenobetaine were 7.1, 3.0, and 0.9 µg/L, respectively. The prevalence of type 2 diabetes was 7.7%. After adjustment for diabetes risk factors and markers of seafood intake, participants with type 2 diabetes had a 26% higher level of total arsenic (95% confidence interval [CI], 2.0%-56.0%) and a nonsignificant 10% higher level of dimethylarsinate (95% CI, –8.0% to 33.0%) than participants without type 2 diabetes, and levels of arsenobetaine were similar to those of participants without type 2 diabetes. After similar adjustment, the odds ratios for type 2 diabetes comparing participants at the 80th vs the 20th percentiles were 3.58 for the level of total arsenic (95% CI, 1.18-10.83), 1.57 for dimethylarsinate (95% CI, 0.89-2.76), and 0.69 for arsenobetaine (95% CI, 0.33-1.48).

Conclusions  After adjustment for biomarkers of seafood intake, total urine arsenic was associated with increased prevalence of type 2 diabetes. This finding supports the hypothesis that low levels of exposure to inorganic arsenic in drinking water, a widespread exposure worldwide, may play a role in diabetes prevalence. Prospective studies in populations exposed to a range of inorganic arsenic levels are needed to establish whether this association is causal.

The purpose of this investigation was to estimate the total hair mercury of diseased people(not including patients of mercury poisoning such as Minamata disease).Hair samples were collected from 133 diseased volunteers in Tokyo and the surrounding areas from Oct. 1992 to June 1993. The total mercury concentrations in the hair of ordinary diseased people( atopic dermatitis, asthma, dementia, cerebral infarct, osteoporosis, hypertension and diabetes) were from 2.08 ppm to 36.5 ppm. Those values were considerably higher than that of healthy people of the same age groups. However, the uptake routes and the metabolic mechanism of high hair mercury concentrations in diseased people are not clear.

Summary
Man, with other primates, lost the ability to synthesize vitamin C through an inactivating mutation of the gene encoding gulonolactone oxidase (GULO) millions of years ago. Though the consequences of this prehistoric loss must have been favorable (and thus selected for) at the population level, the inability to produce vitamin C may have serious health implications for modern humans, especially for those conditions in which antioxidants (like vitamin C) have been implicated as potential therapeutic agents. Two general types of recent findings regarding vitamin C have made re-evaluation of this important nutrient imperative. First, vitamin C is now known to be involved in several novel physiological phenomena including stem cell differentiation and respiratory development, which likely require pharmacological levels of vitamin C. Secondly, the growing recognition that many ageing-related diseases, including heart disease, neural degeneration and cancer, may have a contributing oxidative damage factor that might be reduced by dietary antioxidants such as vitamin C. In this paper, we hypothesize that high serum-level vitamin C provides important, broad-ranging therapeutic benefits in treating ageing-related degenerative diseases. This hypothesis can be readily tested using traditional and newly-developed genetically-engineered animal models.

Background
Excessive oxidative stress is considered one of the mechanisms of a decrease in contractile force without concomitant reduction in oxygen cost in failing myocardium. We hypothesized that the antioxidant vitamin C may help reverse hyporesponsiveness to β-adrenergic stimulation and improve myocardial efficiency in patients with heart failure (HF) after myocardial infarction (MI).

Methods and Results
Nineteen patients with mild to moderate HF due to previous MI (mean left ventricular [LV] ejection fraction 39%) were instrumented with conductance and coronary sinus thermodilution catheters. Left ventricular contractility, expressed as Ees,, the slope of end-systolic pressure-volume relationship, and mechanical efficiency, expressed as the ratio of LV stroke work (SW) to myocardial oxygen consumption (MV̇o2), were measured in response to the intravenous infusion of dobutamine (4 μg/kg per min) before (Dob) and during (Dob + Vit C) the infusion of vitamin C (2.0-g bolus injection and subsequent 50-mg/min infusion through the jugular vein) (vitamin C group, n = 10). The infusion of vitamin C augmented the Ees response to dobutamine by 20% ± 8% (Dob 2.1 ± 0.3, Dob + Vit C 2.5 ± 0.4 mm Hg/mL, P < .01) and the SW/MV̇o2 response by 21% ± 5% (Dob 36% ± 3%, Dob + Vit C 43% ± 4%, P < .01). In the control group (n = 9), E_es and SW/MV̇o2 were measured in response to dobutamine before (Dob) and during (Dob + vehicle) the infusion of saline. No difference in E_es or SW/MV̇o2 was observed between Dob and Dob + vehicle (E_es: Dob 2.1 ± 0.2, Dob + vehicle 2.1 ± 0.2 mm Hg/mL per square meter, P = nonsignificant) (SW/MV̇o2: Dob 35% ± 4%, Dob + vehicle 33% ± 4%, P = nonsignificant).

Conclusion
The administration of the antioxidant vitamin C enhances the contractile response to dobutamine and improves myocardial efficiency in patients with HF.

Objective  To evaluate the relationship of dietary carotenoids, vitamin A, alpha-tocopherol, and vitamin C with prevalent age-related macular degeneration (AMD) in the Age-Related Eye Disease Study (AREDS).

Methods  Demographic, lifestyle, and medical characteristics were ascertained on 4519 AREDS participants aged 60 to 80 years at enrollment. Stereoscopic color fundus photographs were used to categorize participants into 4 AMD severity groups and a control group (participants with < 15 small drusen). Nutrient intake was estimated from a self-administered semiquantitative food frequency questionnaire at enrollment. Intake values were energy adjusted and classified by quintiles. The relationship between diet and AMD status was assessed using logistic regression analyses.

Results  Dietary lutein/zeaxanthin intake was inversely associated with neovascular AMD (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.45-0.93), geographic atrophy (OR, 0.45; 95% CI, 0.24-0.86), and large or extensive intermediate drusen (OR, 0.73; 95% CI, 0.56-0.96), comparing the highest vs lowest quintiles of intake, after adjustment for total energy intake and nonnutrient-based covariates. Other nutrients were not independently related to AMD.

Conclusion  Higher dietary intake of lutein/zeaxanthin was independently associated with decreased likelihood of having neovascular AMD, geographic atrophy, and large or extensive intermediate drusen.

Carotid endarterectomy has been found to be associated with a transient increase in systemic oxidative stress, and this has been shown to be a predictor of restenosis. The aim of this study was to determine the incidence of early recurrent stenosis and investigate a possible role of oxidative stress in its development by measuring the concentration of antioxidant vitamins. Patients undergoing carotid endarterectomy between August 2001 and February 2003 were included in the study. A preoperative blood sample was analyzed for antioxidant vitamin concentrations. All patients were followed up by duplex scans 3 and 12 months postoperatively. Ninety-three patients (101 carotid endarterectomies) were recruited. Nine arteries had developed restenosis by 12 months. Those patients who developed recurrent stenosis had significantly lower vitamin C concentrations (19.10 ± 3.69 vs 30.11 ± 19.10, P = .02) than those who did not. This study suggests that low antioxidant vitamin levels may predispose to early restenosis after carotid endarterectomy.

Plasma C-reactive protein (CRP) is an inflammatory biomarker that predicts cardiovascular disease. Lowering elevated CRP with statins has reduced the incidence of cardiovascular disease. We investigated whether vitamin C or E could reduce CRP. Healthy nonsmokers (N = 396) were randomized to three groups, 1000 mg/day vitamin C, 800 IU/day vitamin E, or placebo, for 2 months. Median baseline CRP was low, 0.85 mg/L. No treatment effect was seen when all participants were included. However, a significant interaction was found, indicating that treatment effect depends on baseline CRP concentration. Among participants with CRP indicative of elevated cardiovascular risk (≥ 1.0 mg/L), vitamin C reduced the median CRP by 25.3% vs placebo (p = 0.02) (median reduction in the vitamin C group, 0.25 mg/L, 16.7%). These effects are similar to those of statins. The vitamin E effect was not significant. In summary, treatment with vitamin C but not vitamin E significantly reduced CRP among individuals with CRP ≥ 1.0 mg/L. Among the obese, 75% had CRP ≥ 1.0 mg/L. Research is needed to determine whether reducing this inflammatory biomarker with vitamin C could reduce diseases associated with obesity. But research on clinical benefits of antioxidants should limit participants to persons with elevations in the target biomarkers.

Background
The prevalence of hypertension and its contribution to cardiovascular disease risk makes it imperative to identify factors that may help prevent this disorder. Extensive biological and biochemical data suggest that plasma ascorbic acid may be such a factor. In this study we examined the association between plasma ascorbic acid concentration and blood pressure (BP) in young-adult women.

Methods
Participants were 242 Black and White women aged 18–21 yr from the Richmond, CA, cohort of the National Heart, Lung and Blood Institute Growth and Health Study. We examined the associations of plasma ascorbic acid with BP at follow-up year 10, and with change in BP during the previous year.

Results
In cross-sectional analysis, plasma ascorbic acid at year 10 was inversely associated with systolic BP and diastolic BP after adjusting for race, body mass index, education, and dietary intake of fat and sodium. Persons in the highest one-fourth of the plasma ascorbic acid distribution had 4.66 mmHg lower systolic BP (95% CI 1.10 to 8.22 mmHg, p = 0.005) and 6.04 mmHg lower diastolic BP (95% CI 2.70 to 9.38 mmHg, p = 0.0002) than those in the lowest one-fourth of the distribution. In analysis of the change in BP, plasma ascorbic acid was also inversely associated with change in systolic BP and diastolic BP during the previous year. While diastolic blood pressure among persons in the lowest quartile of plasma ascorbic acid increased by 5.97 mmHg (95% CI 3.82 to 8.13 mmHg) from year 9 to year 10, those in the highest quartile of plasma vitamin C increased by only 0.23 mmHg (95% CI -1.90 to +2.36 mmHg) (test for linear trend: p < 0.0001). A similar effect was seen for change in systolic BP, p = 0.005.

Conclusion
Plasma ascorbic acid was found to be inversely associated with BP and change in BP during the prior year. The findings suggest the possibility that vitamin C may influence BP in healthy young adults. Since lower BP in young adulthood may lead to lower BP and decreased incidence of age-associated vascular events in older adults, further investigation of treatment effects of vitamin C on BP regulation in young adults is warranted.

Background
Elevated blood pressure (BP) is a major public health problem in the United States with almost 60% of American adults having pre-hypertension or hypertension [1]. The disorder is prevalent in all major ethnic groups, although Blacks are disproportionately affected [1]. As elevated BP is a strong and independent risk factor for cardiovascular and renal disease morbidity and mortality [2], identifying preventive measures is an important public health goal.

The Dietary Approaches to Stop Hypertension (DASH) trial demonstrated that diet is an important factor in BP regulation. In that study, a diet rich in vegetables, fruit, low-fat dairy foods, and with reduced saturated and total fat intake significantly reduced systolic BP and diastolic BP over a period of 8 weeks compared to a control diet [3]. DASH diet constituents believed to contribute to the observed BP-lowering effect include calcium, magnesium, potassium, dietary fiber, and the reduced fat content of the diet [3,4]. The DASH diet is also rich in vitamin C, another possible contributor to the observed BP effect [5]. Mechanistic studies have demonstrated a role of vitamin C in maintaining the normal production and biological activity of endothelium-derived nitric oxide which plays a role in vascular tone and reactivity [6,7]. Thus, plasma ascorbic acid concentration should be investigated for its possible role in lowering or maintaining normal BP.

Numerous cross-sectional studies have observed highly significant inverse relationships between BP and circulating ascorbic acid concentration [8-18]. Almost all such studies have focused on populations that are middle-aged and older, and intervention research has typically focused on treatment of those with already elevated blood pressure. However, we hypothesized that an ascorbic acid association in a young normotensive population might provide clues to the primary prevention of hypertension. Examining this relationship in young adults is potentially important because maintaining healthy BP in healthy young adults may lead to a lower BP in older adults, and consequently a lower incidence of age-associated vascular events [2]. Therefore, we investigated this relationship among 18–21 year old Black and White women enrolled in the National Heart, Lung, and Blood Institute (NHLBI) Growth and Health Study. We hypothesized that plasma ascorbic acid concentration at the 10th annual follow-up visit would be inversely associated with BP, and inversely associated with change in BP during the previous year, in this population group.

Methods
Participants
In 1985, the NHLBI initiated the Growth and Health Study, a 10-year longitudinal multicenter study to investigate the development of obesity in Black and White girls during adolescence, along with its environmental, psychosocial, and cardiovascular disease risk factor correlates. Black and White girls, ages 8 to 11 years, were recruited from Richmond, CA, Cincinnati, OH, and Washington, DC areas. Institutional review board approval was obtained at all participating centers. The parents or guardians of participants gave informed consent for the children to participate. Girls were followed annually through ages 18 to 21 years, with a follow-up rate of 90% at the 10th annual follow-up visit. The sample design, recruitment and selection procedures used for the Growth and Health Study have been previously described [19]. For this investigation, plasma ascorbic acid samples were obtained only from girls in the Richmond, CA cohort at the 10th annual visit. The blood draw for plasma ascorbic acid was implemented midway through the annual data collection period and a total of 335 participants were seen in the clinic after plasma sample collection was initiated. Plasma samples were successfully obtained from 242 participants (72%), consisting of 155 Blacks and 87 Whites. The 93 who did not participate in the extra blood draw were either seen on a day when the ascorbic acid study staff was not present to take their blood, were pregnant, or refused the extra procedure.

Data collection
BP
BP measurements were obtained by trained examiners according to a standard protocol [20]. Participants were seated with feet resting flat on a surface and the right arm resting at heart level. Participants were seated for at least 5 minutes before BP measurements were begun. The appropriate cuff was selected from 5 cuff sizes and placed around the upper arm. Using a standard mercury sphygmomanometer (Baum Desktop model with V-Lok cuffs), three consecutive readings were taken using the same arm and waiting at least 30 seconds between readings. The second and third readings were averaged to determine the mean systolic BP, defined as the onset of the first two consecutive beats (first Korotkoff phase), and the mean diastolic BP, defined as the point at which the sound disappeared (fifth Korotkoff phase). BP was obtained at both the 9th and 10th annual visits.

Plasma ascorbic acid
Participants were instructed to fast for at least 12 hours before the blood draw. Plasma ascorbic acid was determined using the 2,4-dinitrophenylhydrazine method [21], which has been shown to correlate well with HPLC methods [22]. Plasma was stabilized with 10% metaphosphoric acid, frozen at -70°C within 4 hours of the collection, and analyzed within six months. Plasma ascorbic acid was assayed only at the 10th annual visit. Blood stored from earlier visits could not be used for assaying ascorbic acid because it had not been stabilized with metaphosphoric acid.

Anthropometry
At the 10th annual visit, participants were weighed using an electronic scale (SECA Alpha 770) in gowns without shoes. Height was measured using a custom portable stadiometer (Creative Health Products, Plymouth, MI). Participants wore socks and were positioned with heels together, toes apart at a 45 degree angle, and head in the Frankfort horizontal plane. Both weight and height were measured twice and repeated a third time if values differed by more than 0.3 kg and 0.5 cm, respectively. Body mass index (BMI) was calculated as kg/m2.

Socioeconomic and lifestyle variables
Information on socioeconomic and lifestyle variables was ascertained by questionnaire at the 10th annual visit. Smoking was assessed by asking how many days participants smoked in the past 30 days and how many cigarettes were smoked per day. The number of smoking days/month was then multiplied by the number of cigarettes/day to create a continuous variable, cigarettes smoked/month. Alcohol consumption was assessed in a similar fashion, with 1 drink being equivalent to 12 oz. (355 mL) of beer or 6 oz. (177 mL) of wine. The number of hours/week of television or videos watched was assessed as a proxy for physical inactivity. Pregnancy history and current contraceptive use was also obtained.

Dietary variables
Dietary information at the 10th annual visit was determined using 3-day dietary records, covering two consecutive weekdays and one weekend day. Participants used rulers, pictures, and thickness guides to measure and quantify the amount of food consumed. Dietary records were reviewed with a dietitian and analyzed for nutrient composition by the Cincinnati Dietary Center using the University of Minnesota Nutrition Coordinating Center database. The method used for estimating nutrient intake had been previously validated in this population [23]. All micronutrient intake estimates include amounts provided by supplements. Estimates of dietary sodium intake were from food only and no attempt was made to collect information on added dietary salt intake.

Statistical analyses
Unpaired two-tailed t-tests and Wilcoxon two-sample tests were used to compare baseline characteristics of Black and White study participants. Plasma ascorbic acid at year 10 was divided into quartiles, and least squares mean diastolic and systolic BP, adjusted for race, BMI, education, and intake of fat and sodium, were calculated for each quartile using analysis of covariance. Change in BP was calculated as the systolic and diastolic values at year 10 minus their respective values at year 9, and adjusted changes were calculated using analysis of covariance; year 9 BP was included as a covariate in the model. The relationships between plasma ascorbic acid and BP at the 10th annual visit, as well as between plasma ascorbic acid at year 10 and change in BP in the previous year, were also examined as continuous variables using multivariable linear regression models. The interaction of race and BMI with the independent variable was assessed using cross-product terms in the regression models. Annual household income and education were highly correlated. However, education explained more of the variance, and consequently education was used in the models. A number of other covariates were considered as potential confounders, including intake of total energy, potassium, calcium, dietary antioxidants, and fiber, pregnancy history, use of birth control pills, smoking, alcohol consumption, and number of hours/week of television or video watching. However, none was statistically significant and these variables were not included in the final models. Statistical analyses were conducted with SAS 9.1.

Results
Descriptive characteristics and comparisons of the total sample and by race are presented in Table 1. Mean diastolic BP, age, weight, BMI, energy intake, and plasma ascorbic acid concentrations did not differ significantly by race. Black women had higher mean systolic BP, watched more hours/week of television or videos, consumed more fat/day, and lived in households with lower incomes as compared to White women. Blacks also smoked significantly fewer cigarettes, drank less alcohol, and were more likely to have been pregnant (data not shown.) However, race did not significantly modify the relationship between plasma ascorbic acid and BP (interaction terms for systolic and diastolic BP were p = 0.42 and p = 0.47, respectively). Therefore, statistical models included all 242 subjects and were not stratified by race.

For comparison of BP in categories of plasma ascorbic acid, the plasma ascorbic acid distribution among participants at visit 10 was divided into fourths. Mean concentrations of ascorbic acid, by quartile, were as follows: Quartile 1: 0.59 mg/dL (SD 0.18 mg/dL); Quartile 2: 1.03 mg/dL (SD 0.10 mg/dL); Quartile 3: 1.36 mg/dL (SD 0.10 mg/dL); and Quartile 4: 1.83 mg/dL (SD 0.34 mg/dL). (Means in SI units: 33.51 μmol/L, 58.50 μmol/L, 77.25 μmol/L, 103.94 μmol/L for quartiles 1 through 4, respectively.)

In cross-sectional analyses, we examined BP across quartiles of plasma ascorbic acid at the 10th annual visit. There was a significant inverse linear trend in both systolic BP (Figure 1) and diastolic BP (Figure 2) across the quartiles of plasma ascorbic acid concentration (unadjusted p = 0.0001, respectively). In regression analysis using the quartiles as predictor variables, after adjustment for BMI, race, education, and dietary fat and sodium intake, these inverse linear trends remained significant for both systolic BP and diastolic BP, with substantial differences in BP across the quartiles. Persons in the upper one-fourth of the plasma ascorbic acid distribution had 4.66 mmHg lower systolic BP (95% CI 1.10 to 8.22 mmHg, p = 0.005) than those in the lower one-fourth of the plasma ascorbic acid distribution. For diastolic BP, persons in the upper one-fourth of the plasma ascorbic acid distribution had 6.04 mmHg lower diastolic BP (95% CI 2.70 to 9.38 mmHg, p = 0.0002) than those in the lower quartile of ascorbic acid. We also performed multiple regression analysis of ascorbic acid as a continuous variable, with BP as the dependent variable, plasma ascorbic acid as the primary predictive variable, and adjusting for BMI, race, education, dietary fat and sodium intake. Cross-sectionally, as plasma ascorbic acid concentration increased by 1 mg/dL (56.8 μmol/L), systolic BP decreased by 4.1 mmHg (95% CI -6.6 to -1.7 mmHg) and diastolic BP decreased by 4.0 mmHg (95% -6.4 to -1.7 mmHg).

We also examined the association between plasma ascorbic acid concentration at year 10 and change in BP between years 9 and 10. Change in both systolic BP and diastolic BP was inversely associated with plasma ascorbic acid concentration at year 10 (Figure 3) after adjustment for BMI, race, education, and dietary fat and sodium intake. Systolic BP increased by 1.40 mmHg (95% CI -0.76 to +3.57 mmHg) among those in the lowest quartile of the plasma ascorbic acid distribution, but decreased in persons in higher quartiles of plasma ascorbic acid (test for linear trend in change in BP across quartiles of year 10 ascorbic acid: p = 0.005). Diastolic BP increased overall, but the increase was less with increasing quartiles of plasma ascorbic acid. While diastolic blood pressure among persons in the lowest quartile of plasma ascorbic acid increased by 5.97 mmHg (95% CI 3.82 to 8.13 mmHg) from year 9 to year 10, those in the highest quartile of plasma vitamin C increased by only 0.23 mmHg (95% CI -1.90 to +2.36 mmHg) (test for linear trend: p < 0.0001). Control for weight change between years 9 and 10 made essentially no difference in these results (data not shown).

Discussion
We found plasma ascorbic acid concentration to be inversely associated with systolic and diastolic BP in young-adult Black and White women, independent of race, BMI, education, diet, and lifestyle factors. A 1 mg/dL (56.8 μmol/L) increase in plasma ascorbic acid levels was associated with 4.1 mmHg lower systolic blood pressure and 4.0 mmHg lower diastolic blood pressure. Plasma ascorbic acid levels in this cohort ranged from 0.22 to 3.13 mg/dL (12.5 to 177.8 μmol/L), indicating that a 1 mg/dL change in plasma ascorbic acid level is achievable in this young population.

Plasma ascorbic acid concentration was also inversely and significantly associated with change in BP during the previous year. It is particularly notable that there was very little increase in diastolic BP in persons in the highest quartile of ascorbic acid.

The magnitude of the decrease in systolic and diastolic blood pressure associated with plasma ascorbic acid is consistent with the range of values found in other cross-sectional studies [8-18]. A review by Ness [18] found that the blood pressure difference associated with a 50 μmol/L (0.88 mg/dL) difference in ascorbic acid concentration ranged from -2.6 to -9.4 mmHg for diastolic blood pressure, and from -3.6 to -17.8 mmHg for systolic blood pressure.

Intervention trials have been less consistent [24-37]. Many of the studies that failed to find a treatment effect have had design limitations such as no control group or no placebo control, short duration, small sample size, concomitant use of non-study dietary supplements containing vitamin C, and varying or inadequately described methods for measuring BP; or they were post-hoc analyses where change in BP was not a primary endpoint of the trial. On the other hand, some studies have found significant reductions in BP as a result of treatment with vitamin C [38-41].

The DASH study [3] is the major intervention trial of nutritional factors, and our results are comparable in magnitude to those of DASH. Among all participants in the DASH study, the DASH diet lowered mean systolic BP by 5.5 mmHg, and lowered mean diastolic BP by 3.0 mmHg. In the present study, the difference between the mean BP in the first and fourth quartiles of ascorbic acid concentration was 4.7 mmHg systolic, and 6.1 mmHg diastolic BP. This suggests the possibility that if the ascorbic acid concentration of those in the lower one-fourth of the distribution could be increased to the ascorbic acid concentration of those in the top one-fourth of the distribution, an effect comparable to that of the DASH diet could be achieved. The present study was not an intervention study and such an intervention effect is only a hypothesis, but one which would seem to merit follow-up.

The ranges of plasma ascorbic acid seen in our sample are very consistent with those found in the United States. We examined data from the National Health and Nutrition Examination Survey (NHANES) 2003–2004, among women in the same age group, 18–21 years. The mean plasma ascorbic acid concentrations in the four quartiles were 0.43 mg/dL, 0.84 mg/dL, 1.14 mg/dL, and 1.59 mg/dL (24.1, 47.8, 64.8, 90.1 μmol/L). (Block, unpublished data.) In our sample those means were 0.59, 1.03, 1.36 and 1.83 mg/dL. Thus, in the present sample the first three quartiles were similar although slightly higher than those seen in representative national data. The lower two quartiles represent ascorbic acid concentrations most likely obtained from fruits, vegetables and fortified foods such as cereals. A diet rich in fruits and vegetables can produce a concentration similar to that seen in the third quartile. The concentration in the fourth quartile represents a level in which supplements containing vitamin C have made a substantial contribution.

There is substantial biologic rationale for a causal role of ascorbic acid in maintaining normal BP. Numerous oxidative mechanisms appear to be involved in the pathogenesis of hypertension [6,7,42]. One well-studied oxidative stress biomarker is F2-isoprostane, a vasoactive product of lipid peroxidation [43]; we have shown in a randomized trial that supplementation with vitamin C, but not with vitamin E, significantly reduces F2-isoprostane [44]. Similarly inflammation, consistently associated with increased risk of cardiovascular disease, is associated with impaired endothelium-dependent vasodilation and hypertension [45]. Bautista found a progressive increase in blood pressure with increases in high-sensitivity C-reactive protein (hsCRP), a sensitive marker of inflammation [45]. We showed, in a randomized trial, that vitamin C but not vitamin E significantly lowered hsCRP, to an extent equivalent to that seen with statins [46]. Thus, vitamin C may have a beneficial effect on BP by mitigating the adverse effects of inflammation and oxidative stress. Specific functions of vitamin C have also been shown. These include effects on smooth muscle contractility of peripheral blood vessels and improvement of vasomotor dysfunction [47], prevention of nitric oxide inhibition of release of endothelium-derived relaxing factor [48], and prevention of free radical inhibition of prostacyclin synthetase. Ascorbic acid may also influence BP by maintaining the normal production and biological activity of nitric oxide through enhanced recycling of tetrahydrobiopterin, a cofactor that stabilizes and sustains the activity of endothelial nitric oxide synthase [49-52].

An important limitation of this study is the fact that the results depicted in Figures 1 and 2 are cross-sectional and therefore causality cannot be inferred. Also, the data represented in Figure 3 are limited by the fact that there were no plasma ascorbic acid measurements for the 9th annual visit, and therefore the association with change in BP, while longitudinal, is not truly prospective. In interpreting our findings it is important to consider the fact that dietary variables are often correlated with one another and may be correlated with lifestyle variables. Therefore, it is possible that plasma ascorbic acid concentration is simply a marker for another variable that influences BP. However, the association persisted even after controlling for BMI, race, education, and intake of fat, sodium and antioxidants. We also evaluated the effect of controlling for other potential confounders including smoking, alcohol consumption, television or video watching, and intake of total energy, calcium, and potassium, and none diminished the strength of the association.

Nevertheless, while we cannot confidently infer causality, our findings point to the important possibility that vitamin C may influence BP even among healthy young adults. This finding is of importance because lowering BP or attenuating increases in BP in young adults may lead to lower BP in older adults, which in turn may reduce the risk of age-associated vascular events. Therefore, our findings suggest that further study of the relationship between vitamin C and BP in this young-adult population is warranted.

Conclusion
This is the first study to report on the relationship between plasma ascorbic acid concentration and BP in a cohort of young, normotensive women, aged 18–21 years. Plasma ascorbic acid concentration was found to be inversely associated with BP and with change in BP over the previous year. These inverse relationships were observed in a sample where two-thirds of participants were Black, a population that suffers disproportionately from elevated BP and its sequelae. Lowering BP or attenuating increases in BP in healthy young adults may lead to lower BP in older adults and reduced risk of age-associated vascular events. This study suggests that vitamin C may be an important factor in BP regulation even among health young adults, and that further study is warranted.

References

1. Wang Y, Wang QJ: The prevalence of prehypertension and hypertension among US adults according to the new Joint National Committee Guidelines.

   Arch Intern Med 2004, 164:2126-2134. PubMed Abstract | Publisher Full Text

   Return to text

    

2. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr, Jones DW, Materson BJ, Oparil S, Wright JT Jr, Roccella EJ: The Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report.

   JAMA 2003, 289:2560-2572. PubMed Abstract | Publisher Full Text

   Return to text

    

3. Appel LJ, Moore TJ, Obarzanek E, Vollmer WM, Svetkey LP, Sacks FM, Bray GA, Vogt TM, Cutler JA, Windhauser MM, Lin PH, Karanja N: A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group.

   N Eng J Med 1997, 336:1117-1124. Publisher Full Text

   Return to text

    

4. Miller ER, Erlinger TP, Young DR, John M, Charleston J, Rhodes D, Wasan SK, Appel LJ: Results of the diet, exercise, and weight loss intervention trial (DEW-IT).

   Hypertension 2002, 40:612-618. PubMed Abstract | Publisher Full Text

   Return to text

    

5. Svetkey LP, Loria CM: Blood pressure effects of vitamin C: What's the key question?

   Hypertension 2002, 40:789-791. PubMed Abstract | Publisher Full Text

   Return to text

    

6. Frei B: On the role of vitamin C and other antioxidants in atherogenesis and vascular dysfunction.

   Proc Soc Exp Biol Med 1999, 222:196-204. PubMed Abstract | Publisher Full Text

   Return to text

    

7. Duvall WL: Endothelial dysfunction and antioxidants.

   Mt Sinai J Med 2005, 72(2):71-80. PubMed Abstract | Publisher Full Text

   Return to text

    

8. Jacques PF: A cross-sectional study of vitamin C intake and blood pressure in the elderly.

   Int J Vitam Nutr Res 1992, 62(3):252-255. PubMed Abstract

   Return to text

    

9. Salonen JT, Salonen R, Ihanainen M, Parviainen M, Seppanen R, Kantola M, Seppanen K, Rauramaa R: Blood pressure, dietary fats, and antioxidants.

   Am J Clin Nutr 1988, 48:1226-1232. PubMed Abstract | Publisher Full Text

   Return to text

    

10. Riemersma RA, Oliver M, Elton RA, Alfthan G, Vartiainen E, Salo M, Rubba P, Mancini M, Georgi H, Vuilleumeir JP: Plasma antioxidants and coronary heart disease: vitamins C and E, and selenium.

    Eur J Clin Nutr 1990, 44:143-150. PubMed Abstract

    Return to text

     

11. Koh ET, Stewart T: Interrelationship among the blood components and anthropometric measurements.

    Nutr Rep Int 1978, 18:539-549.

    Return to text

     

12. Koh ET, Chi MS: Relationship of serum vitamin C and globulin fractions with anthropometric measurements in adults.

    Nutr Rep Int 1980, 21:537-549.

    Return to text

     

13. Yoshioka M, Matsushita , Chuman Y: Inverse association of serum ascorbic acid level and blood pressure or rate of hypertension in male adults aged 30–39 years.

    Int J Vitam Nutr Res 1984, 54(4):343-347. PubMed Abstract

    Return to text

     

14. Choi ESK, Jacques PF, Dallal GE, Jacob RA: Correlation of blood pressure with plasma ascorbic acid.

    Nutr Res 1991, 11:1377-1382. Publisher Full Text

    Return to text

     

15. Moor de Burgos A, Wartanowicz M, Ziemlanski S: Blood vitamin and lipid levels in overweight and obese women.

    Eur J Clin Nutr 1992, 46:803-808. PubMed Abstract

    Return to text

     

16. Moran JP, Cohen L, Greene JM, Xu G, Feldman EB, Hames CG, Feldman DS: Plasma ascorbic acid concentrations relate inversely to blood pressure in human subjects.

    Am J Clin Nutr 1993, 57:213-217. PubMed Abstract | Publisher Full Text

    Return to text

     

17. Toohey L, Harris MA, Allen KG, Melby CL: Plasma ascorbic acid concentrations are related to cardiovascular risk factors in African-Americans.

    J Nutr 1996, 126:121-128. PubMed Abstract | Publisher Full Text

    Return to text

     

18. Ness AR, Khaw K, Bingham S, Day NE: Vitamin C status and blood pressure.

    J Hypertens 1996, 14:503-508. PubMed Abstract | Publisher Full Text

    Return to text

     

19. The National Heart, Lung, and Blood Institute Growth and Health Study Research Group: Obesity and cardiovascular disease risk factors in black and white girls: The NHLBI Growth and Health Study.

    Am J Public Health 1992, 82:1613-1620. PubMed Abstract | Publisher Full Text | PubMed Central Full Text

    Return to text

     

20. Task Force on Blood Pressure Control in Children: Report of the Second Task Force on Blood Pressure Control in Children.

    Pediatrics 1987, 79:1-25. PubMed Abstract

    Return to text

     

21. US Department of Health and Human Services UPHS, Centers for Disease Control, Clinical Chemistry Division: Laboratory procedures used by the clinical chemistry division, for the second national health and nutrition examination survey (NHANES II) 1976–1980. IV-analytical methods, vitamin C. Atlanta, GA: Centers for Disease Control; 1979.

    Return to text

     

22. Sauberlich HE, Kretsch MJ, Taylor PC, Johnson HL, Skala JH: Ascorbic acid and erythorbic acid metabolism in nonpregnant women.

    Am J Clin Nutr 1989, 50:1039-1049. PubMed Abstract | Publisher Full Text

    Return to text

     

23. Crawford PB, Obarzanek E, Morrison J, Sabry ZI: Comparative advantage of 3-day food records over 24-hour recall and 5-day food frequency validated by observation of 9- and 10-year-old girls.

    J Am Diet Assoc 1994, 94:626-630. PubMed Abstract | Publisher Full Text

    Return to text

     

24. Hajjar IM, George V, Sasse EA, Kochar MS: A randomized, double-blind, controlled trial of vitamin C in the management of hypertension and lipids.

    Am J Ther 2002, 9:289-293. PubMed Abstract | Publisher Full Text

    Return to text

     

25. Koh ET: Effect of vitamin C on blood parameters of hypertensive subjects.

    J Okla State Med Assoc 1984, 77(6):177-182. PubMed Abstract

    Return to text

     

26. Feldman EB, Gold S, Greene J, Moran J, Xu G, Shultz GG, Hames CG, Feldman DS: Ascorbic acid supplements and blood pressure: a four week pilot study.

    Ann N Y Acad Sci 1992, 669:342-344. PubMed Abstract | Publisher Full Text

    Return to text

     

27. Mostafa SE, Garner DD, Garrett L, Whaley RF, El-Sekate M, Kiker M: Beneficial effects of vitamin C on risk factors of cardiovascular diseases.

    J Egypt Public Health Assoc 1989, 64:123-133. PubMed Abstract

    Return to text

     

28. Osilesi O, Trout DL, Ogunwole JO, Glover EE: Blood pressure and plasma lipids during ascorbic acid supplementation in borderline hypertensive and normotensive adults.

    Nutr Res 1991, 11:405-412. Publisher Full Text

    Return to text

     

29. Lovat LB, Lu Y, Palmer AJ, Edwards R, Fletcher AE, Bulpitt CJ: Double-blind trial of vitamin C in elderly hypertensives.

    J Hum Hypertens 1993, 7:403-405. PubMed Abstract

    Return to text

     

30. Galley HF, Thornton J, Howdle PD, Walker BE, Webster NR: Combination oral antioxidant supplementation reduces blood pressure.

    Clinical Science 1997, 92:361-365. PubMed Abstract

    Return to text

     

31. Fotherby MD, Williams JC, Forster LA, Craner P, Ferns GA: Effects of vitamin C on ambulatory blood pressure and plasma lipids in older persons.

    J Hypertens 2000, 18:411-415. PubMed Abstract | Publisher Full Text

    Return to text

     

32. Miller ER, Appel LJ, Levander OA, Levine DM: The effect of antioxidant vitamin supplementation on traditional cardiovascular risk factors.

    J Cardiovasc Risk 1997, 4(1):19-24. PubMed Abstract | Publisher Full Text

    Return to text

     

33. Kim MK, Sasaki S, Sasazuki S, Okubo S, Hayashi M, Tsugane S: Lack of long-term effect of vitamin C supplementation on blood pressure.

    Hypertension 2002, 40:797-803. PubMed Abstract | Publisher Full Text

    Return to text

     

34. Ghosh SK, Ekpo EB, Shah IU, Girling AJ, Jenkins C, Sinclair AJ: A double-blind, placebo-controlled parallel trial of vitamin C treatment in elderly patients with hypertension.

    Gerontology 1994, 40:268-272. PubMed Abstract

    Return to text

     

35. Mullan BA, Young IS, Fee H, McCance DR: Ascorbic acid reduces blood pressure and arterial stiffness in type 2 diabetes.

    Hypertension 2002, 40:804-809. PubMed Abstract | Publisher Full Text

    Return to text

     

36. Ward NC, Hodgson JM, Croft KD, Burke V, Beilin LJ, Puddey IB: The combination of vitamin C and grape-seed polyphenols increases blood pressure: a randomized, double-blind, placebo-controlled trial.

    J Hypertens 2005, 23:427-434. PubMed Abstract | Publisher Full Text

    Return to text

     

37. Duffy SJ, Gokce N, Holbrook M, Huang A, Frei B, Keaney JF Jr, Vita JA: Treatment of hypertension with ascorbic acid.

    Lancet 1999, 354:2048-2049. PubMed Abstract | Publisher Full Text

    Return to text

     

38. Rodrigo R, Prat H, Passalacqua W, Araya J, Bachler JP: Decrease in oxidative stress through supplementation of vitamins C and E is associated with a reduction in blood pressure in patients with essential hypertension.

    Clin Sci 2008, 114:625-634. PubMed Abstract | Publisher Full Text

    Return to text

     

39. Plantinga Y, Ghiadoni L, Magagna A, Giannarelli C, Franzoni F, Taddei S, Salvetti A: Supplementation with vitamins C and E improves arterial stiffness and endothelial function in essential hypertensive patients.

    Am J Hypertens 2007, 20:392-397. PubMed Abstract | Publisher Full Text

    Return to text

     

40. Ward NC, Hodgson JM, Croft KD, Burke V, Bellin LJ, Puddey IB: The combination of vitamin C and grape-seed polyphenols increases blood pressure: a randomized, double-blind, placebo-controlled trial.

    J Hypertens 2005, 23:427-434. PubMed Abstract | Publisher Full Text

    Published on 09-04-2009 | Click for complete article...