Search

Background: The toxicity of lead, like any xenobiotic, is directly linked to the duration of exposure and toxin concentration in the body. The elevation in blood lead levels (BLLs) in young Flint, Michigan children noted in time-periods before, and during the 18-month exposure to Flint River water (FRW) from 25 April 2014 to 15 October 2015 is well-known internationally. The length of time BLLs were elevated is unknown, yet key in understanding the potential health impact of the event. The objective of this study was to evaluate whether BLLs in Flint children were increased during the entire 18-month FRW exposure compared to similar earlier time periods. Methods: We conducted a retrospective study analyzing BLLs from Flint children aged 5 years and under. The geometric mean (GM) BLLs and percentages of BLLs ≥5.0 μg/dL in Period I: 25 April 2006 to 15 October 2007 (earliest timeframe available for study) and Period II: 25 April 2012 to 15 October 2013 (timeframe immediately before the water switch), were compared to Period III, 25 April 2014 to 15 October 2015 (FRW exposure). Results: There were 5663 BLLs available for study. GM ± SE BLLs decreased from 2.19 ± 0.03 μg/dL in Period I to 1.47 ± 0.02 μg/dL in Period II [95% CI, 0.64, 0.79]; p<.001 and decreased further to 1.32 ± 0.02 µg/dL during the FRW Period III [95% CI, 0.79, 0.95]; p<.001. The percentage of BLLs ≥5.0 μg/dL decreased from Period I (10.6%) to Period II (3.3%) [95% CI, 5.7, 8.8]; p<.001 and from Period I to Period III (3.9%) [95% CI, 5.0, 8.2]; p=.002. The 0.6% increase from Period II to Period III was not statistically significant [95% CI, −1.9, 0.57]; p=.30. Conclusion: Analyses of GM and percentages ≥5.0 μg/dL of BLLs do not support the occurrence of a global increase in BLLs in young children of Flint during the entire 18-month period of FRW exposure. [ABSTRACT FROM AUTHOR]

Objectives: To assess the extent of lead content of sindoor, a powder used by Hindus for religious and cultural purposes, which has been linked to childhood lead poisoning when inadvertently ingested. Methods: We purchased 95 samples of sindoor from 66 South Asian stores in New Jersey and 23 samples from India and analyzed samples with atomic absorption spectrophotometry methods for lead. Results: Analysis determined that 79 (83.2%) sindoor samples purchased in the United States and 18 (78.3%) samples purchased in India contained 1.0 ormoremicrograms of lead per gram of powder. ForUS samples, geometric mean concentration was 5.4micrograms per gramcompared with 28.1microgramsper gram for Indiasamples. Themaximumlead content detected in both US and India samples was more than 300 000 micrograms per gram. Of the examined USsindoor samples,19%containedmore than 20micrograms per gram of lead (US Food and Drug Administration [FDA] limit); 43% of the India samples exceeded this limit. Conclusions: Results suggested continued need for lead monitoring in sindoor in the United States and in sindoor carried into the United States by travelers from India, despite FDA warnings. [ABSTRACT FROM AUTHOR]

This study quantified the effects of local intramedullary delivery of an organic vanadium salt, which may act as an insulin-mimetic on fracture healing. Using a BB Wistar rat femoral fracture model, local vanadyl acetylacetonate (VAC) was delivered to the fracture site and histomorphometry, mechanical testing, and immunohistochemistry were performed. Callus percent cartilage was 200% higher at day 7 ( p < 0.05) and 88% higher at day 10 ( p < 0.05) in the animals treated with 1.5 mg/kg of VAC. Callus percent mineralized tissue was 37% higher at day 14 ( p < 0.05) and 31% higher at day 21 ( p < 0.05) in the animals treated with 1.5 mg/kg of VAC. Maximum torque to failure was 104% and 154% higher at 4 weeks post-fracture ( p < 0.05) for the healing femurs from the VAC-treated (1.5 and 3.0 mg/kg) animals. Animals treated with other VAC doses demonstrated increased mechanical parameters at 4 weeks ( p < 0.05). Immunohistochemistry detected 62% more proliferating cells at days 7 ( p < 0.05) and 94% more at day 10 ( p < 0.05) in the animals treated with 1.5 mg/kg VAC. Results showed 100% more vascular endothelial growth factor-C (VEGF-C) positive cells and 80% more blood vessels at day 7 ( p < 0.05) within the callus subperiosteal region of VAC-treated animals (1.5 mg/kg) compared to controls. The results suggest that local VAC treatment affects chondrogenesis and angiogenesis within the first 7-10 days post-fracture, which leads to enhanced mineralized tissue formation and accelerated fracture repair as early as 3-4 weeks post-fracture. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1971-1978, 2012 [ABSTRACT FROM AUTHOR]

FK506 binding proteins (FKBPs), also called immunophilins, are prolyl-isomerases (PPIases) that participate in a wide variety of cellular functions including hormone signaling and protein folding. Recent studies indicate that proteins that contain PPIase activity can also alter the processing of Alzheimer's Amyloid Precursor Protein (APP). Originally identified in hematopoietic cells, FKBP52 is much more abundantly expressed in neurons, including the hippocampus, frontal cortex, and basal ganglia. Given the fact that the high molecular weight immunophilin FKBP52 is highly expressed in CNS regions susceptible to Alzheimer's, we investigated its role in β toxicity. Towards this goal, we generated β transgenic Drosophila that harbor gain of function or loss of function mutations of FKBP52. FKBP52 overexpression reduced the toxicity of β and increased lifespan in β flies, whereas loss of function of FKBP52 exacerbated these β phenotypes. Interestingly, the β pathology was enhanced by mutations in the copper transporters Atox1, which interacts with FKBP52, and Ctr1A and was suppressed in FKBP52 mutant flies raised on a copper chelator diet. Using mammalian cultures, we show that FKBP52 (-/-) cells have increased intracellular copper and higher levels of β. This effect is reversed by reconstitution of FKBP52. Finally, we also found that FKBP52 formed stable complexes with APP through its FK506 interacting domain. Taken together, these studies identify a novel role for FKBP52 in modulating toxicity of β peptides. [ABSTRACT FROM AUTHOR]

BACKGROUND: It is widely recognized that blood lead concentrations are higher in the summer than in winter. Although the effects of some environmental factors such as lead in dust on this phenomenon have been studied, relationships to sunlight-induced vitamin D synthesis have not been adequately investigated. Vitamin D status is influenced by the diet, sunlight exposure, age, skin pigmentation, and other factors, and may modify gastrointestinal lead absorption or release of lead stored in bones into the bloodstream. OBJECTIVE AND METHODS: We collected paired blood samples from 142 young, urban African-American and Hispanic children in the winter and summer to study the seasonal increase in blood lead and its relationships to vitamin D nutrition, age, and race. RESULTS: A winter/summer (W/S) increase in blood lead concentrations of 32.4% was found for children 1-3 years of age. There was a smaller W/S increase of 13.0% in children 4-8 years of age. None of the 51 Hispanic children had an elevated blood lead concentration (= 10 µg/dL) during the winter, and only one had an elevated summertime concentration. In contrast, elevated blood lead concentrations were frequent in the 91 African-American children, especially those 1-3 years of age. For the latter, the percentage with elevated blood lead levels increased from 12.2% in winter to 22.5% in summer. A 1.2% W/S increase in serum 25-hydroxy-vitamin D (serum 25-OH-D) concentrations was found for children 1-3 years of age. However, in children 4-8 years of age the W/S increase in serum 25-OH-D was much larger-33.6%. The percentages of children with low (< 16 µg/L) serum 25-OH-D concentrations were 12.0% in winter and 0.7% in summer and were consistently greater in African-American than in Hispanic children. The seasonal increases in blood lead and serum 25-OH-D in children 4-8 years of age were significantly associated. CONCLUSION: The higher summertime serum 25-OH-D concentrations for the 4- to 8-year-old children are likely caused by increased sunlight-induced vitamin D synthesis and may contribute to the seasonal increase in blood lead. Age and race are key factors that affect blood lead and vitamin D nutrition, as well as their interactions, in young urban children. [ABSTRACT FROM AUTHOR]

Objectives: Little is known about the relationship between the renal and gastrointestinal excretion of potassium in humans. This information is important in light of strong associations of potassium intake with hypertension and occlusive stroke.Methods: We determined the relationship between fecal and urinary excretion of potassium under both fixed and variable potassium intakes using our unpublished archival data and published data of others. Twenty-five subjects were evaluated.Results: On a fixed, low oral potassium intake (61.2 +/- 4.7 mmol/day; mean +/- SD), there was an inverse relationship between fecal and urinary potassium excretion (r = -0.66, p = 0.040). In studies in which potassium intake varied between 61-135 mmol/day, fecal and urinary potassium excretions were positively correlated (r = 0.58, p = 0.024). Considerable within-and-between-subject variation was observed in the relationship between fecal and urinary potassium excretion.Conclusions: Inter-individual variation in fecal potassium excretion may arise from both variation in dietary potassium intake and intrinsic individual differences in the renal versus gastrointestinal handling of potassium. [ABSTRACT FROM AUTHOR]

Examines the relation between blood lead concentrations and Apgar pregnancy scores. Correlation between blood lead concentrations to reproductive outcomes; Relationship between maternal blood lead concentrations with hypertension in pregnancy; Effects of low-dose lead exposure on pregnancy outcomes.

The polyketide antibiotic Frenolicin-B (FB) produces anorexia and esophageal epithelial hyperplasia (EH) in rats, findings that are characteristic of zinc deficiency. Because FB also chelates divalent cations in vitro, we conducted studies to determine whether FB modifies blood and organ concentrations of zinc and other essential metals (calcium, copper, iron and magnesium). Groups of male Sprague-Dawley rats ( approximately 250g; n = 20/group) consumed diets with adequate (40 microg/g), deficient (<2 microg/g) or fortified (100 microg/g) zinc concentrations ad libitum for 28 d. Two groups fed either Zn-adequate or Zn-fortified diets also were given 100 mg/(kg. d) of FB in diet, and 2 groups were pair-fed controls. Histopathology or metal analyses were performed on tissues from 10 rats/group. FB caused EH of the nonglandular stomach but not of other tissues. Of the metals evaluated, only copper concentrations were significantly reduced in all tissues examined except kidney. A broad range of kidney copper concentrations was found; these concentrations were associated with plasma copper and proteinaceous deposits within tubules. In rats, FB substantially and selectively depletes Cu in vivo, suggesting that drugs with structures that permit metal chelation should be evaluated for their potential to alter trace metal nutriture. [ABSTRACT FROM AUTHOR]

Assesses relations among HIV-1 progression and nutritional and demographic variables. Dependence of immune function on nutritional status due to the large mass and high rate of cellular turnover of the immune system, making it a major user of nutrients; Evidence compromising nutritional and antioxidant status in the course of HIV-1 infection.

Focuses on the impact of pregnant women's lead exposure to fetal growth. Investigation of conditions leading to the fetal transfer of lead in laboratory mice; Comparison of fetal growth; Importance of considering of how dietary exposure to the compound can lead to lower birth rates.

Investigates the risk for lead poisoning of urban children by studying the dietary calcium intakes of urban children in Newark, New Jersey. Comparison of the children's calcium intakes with the Dietary Reference Guide; Significant health risks posted by lead exposure and low dietary calcium intakes of urban minority children.

Studies the effects of dietary calcium and lead exposure on lead toxicity, fetal and neonatal growth, erythropoiesis and blood pressure during pregnancy and lactation in rats. Reduction in dam and pup hemoglobin concentrations, hematocrits, body weights and lengths; Dam systolic blood pressure; Prevention of increases in free erythrocyte protoporphyrin.

Zinc nutriture and immune function were studied in 100 subjects, age 60-89 yr. Mean (±SD) zinc concentrations found were 84.8 ± 15.5 µ1 .04 ± 0.24 ; µg (0.016 ± 0.004 µmol)/109 cells for mononuclear cells, 3.9 1 ± 1 .77 µg (0.060 ± 0.027 µmol)/109 cells for platelets, and 222 ± 101 µg (3.39 ± 1.54 µmol)/g for hair. Zinc ingestion was below the RDA in more than 90% of study subjects. The incidence of anergy to a panel of seven skin test antigens was 41%; responses to these antigens were significantly associated with the plasma zinc concentration. Subjects with depressed lymphocyte responses to mitogens had significantly lower platelet and significantly higher mononuclear cell zinc concentrations than those with normal responses. [ABSTRACT FROM AUTHOR]

A placebo-controlled double-blind trial of the effects of daily micronutrient supplements on circulating vitamin and trace metal concentrations and delayed-hypersensitivity skim test (DHST) responses was conducted. Subjects, aged 59-85 y, were randomly assigned o placebo (n = 27) or micronutrient (n = 29) treatment groups. DHST and circulating concentrations of nine micronutrients were measured before and after 6 and 12 mo of micronutrient ingestion. For the micronutrient group, there were statistically significant increases at 6 and/or 12 mo in the mean serum concentrations of ascorbate, β-carotene, folate, vitamin B-6, and α-tocopherol. There was a significant increase at 12 mo in the number of subjects in the placebo group with one or more low concentrations. DHST responses o a panel of seven recall antigens were significantly increased at 12 mo in the micronutrient group but not the placebo group. This study demonstrates that daily supplementation with low-to-moderate doses of micronutrients can prevent low concentrations of some micronutrients and can improve DHST responses in healthy, independently living olden adults. [ABSTRACT FROM AUTHOR]

One hundred and three apparently healthy elderly subjects age 60-89 y were randomly assigned to one of three treatments: placebo, 15 mg zinc/d, or 100 mg Zn/d for 3 mo. Plasma Zn was significantly increased only in the 100 mg Zn group. Zn concentrations in erythrocytes, platelets, mononuclear cells, and polymorphonuclear leukocytes were not significantly increased by any treatment. None of the treatments significantly altered delayed dermal hypersensitivity(DDH)to a panelofseven recall antigens or in vitrolymphocyte proliferative responses (LPR) to mitogens and antigens. Fifteen subjects had initially poor lymphocyte proliferative responses that improved in 14 of these individuals during the study; this was not due to Zn supplementation but might have been caused by one or more components of a vitamin-mineral supplement administered to all study subjects. [ABSTRACT FROM AUTHOR]

After a routine blood testing, a local pediatrician discovered that a 13-month-old boy had an elevated blood lead level (BLL) of 57 µg/dL. Since the baby was mostly breast-fed, the pediatrician did a blood test on the mother, and the result showed a BLL of 85 µg/dL. As the mother denied any history of pica behavior, the pediatrician suspected a source of lead to which the entire family might have been exposed and tested the father's BLL. The results showed a BLL of 95 µg/dL, and the pediatrician informed the poison center. The subsequent epidemiological investigation revealed that the parents had used a product called Sindoor for food coloring. Laboratory analyses showed that the product contains more than 57.8% of acid-extractable lead by weight. Given the extremely high content of Pb in this product, Sindoor poses a serious risk of lead poisoning if it is used for food coloring. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Elevated blood lead levels in children associated with the Flint drinking water crisis: a spatial analysis of risk and public health response," by M. Hanna-Attisha and colleagues in a 2016 issue.

Presents a letter to the editor concerning the article of Ballew and Bowman on the effect of dietary calcium in reducing lead toxicity published in the 2001 issue of 'Nutrition Reviews.' Protective effect of dietary calcium against lead toxicity in human; Calcium-lead interaction; Lead absorption.

Several letters to editor are presented in response to articles in previous issues including one on the do-it-yourself pregnancy testing and passed legislation in California and another one on the nutrition of vitamin A hypovitaminemia in a number of migrant farm workers who have adequate dietary intake.

Low dietary selenium may exacerbate iodine deficiency and compromise thyroid function. We studied relationships among selenium nutrition, thyroid function, and pregnancy outcomes by conducting a case-control study nested within a cohort of young, healthy women participating in the Camden (NJ) Study, a 20-year ongoing investigation of effects of maternal nutrition on pregnancy outcomes. Cases were 107 women who delivered pre-term and controls were 126 women who delivered full-term neonates. The mean gestational age at blood collection was 15.6 ± 0.6 weeks (mean ± SE). All subjects had a serum selenium concentration within the laboratory normal range (7.0-16.0 µg/dL). Serum selenium concentrations were higher in cigarette smokers, but were not significantly associated with preterm delivery or serum TSH. Neonates born to mothers in the lowest decile of serum selenium (decile median =8.57 µg/dL=l.0.9 µmol/L) had significantly lower birth weights (β = -259 ± 100 g) compared to those in the 9 highest deciles. For the subgroups of full-term and pre-term neonates maternal serum selenium and birth weight were significantly associated only for the full-term deliveries. For full-term pregnancies low-normal serum selenium in the first or second trimester predicts substantially lower birth weight, but prematurity masks this relationship. The effects of selenium do not appear to be mediated by effects on thyroid function. [ABSTRACT FROM AUTHOR]

It has been hypothesized that the high rate of bone remodeling during childhood and the consequent high calcium and lead turnover result in a substantial reduction in bone lead stores so that much of the lead incorporated in bone during childhood does not persist into adulthood. We studied the effect of age at lead exposure on blood and organconcentrations of lead, calcium, and zinc 1--5 months after termination of lead ingestion. Blood and organ lead concentrations and contents 4 weeks after lead exposure ceased were significantly higher in the rats exposed beginning at 5 weeks of age than in those exposed beginning at 10 or 15 weeks old. Bone lead declined as the time since exposure increased. Despite this trend, the rats exposed when youngest had bone lead concentrations at 20 weeks after the termination of leadexposure that were higher than those of the other rats only 4 weeks after cessation of lead ingestion. Multiple regression analysis demonstrated that age at lead exposure remained a significant predictor ofblood and organ lead concentrations and contents even after the inclusion of total lead consumed, body weight, and age at organ harvesting in the regression analysis. There were only small differences in organ calcium and zinc concentrations among treatment groups except forkidney calcium. The results do not support the hypothesis of rapid depletion of bone lead stores in young animals, but rather suggest that younger age at lead exposure is associated with greater lead retention and toxicity even in the absence of continued lead exposure. [ABSTRACT FROM AUTHOR]

Examines the toxicity of lead extracted from printed paper at physiological values of hydrogen-ion concentration. Analysis on the various substances of trace metals; Effects of swallowed lead on the health of children; Assessment on the ubiquity of lead as an environmental contaminant.

Determines the effects of lead on sertoli cell function marker proteins in Sprague Dawley rats. Measurement of androgen binding protein and inhibin in testicular fluids; Effects of water ingestion with lead acetate; Impact on an increased epididymal androgen on seminal vesicle weight.