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Biomedical subjects

J D Bogden

Publications and source records attributed to J D Bogden.

At least 19 recordsLinked to original sources
PubMed1999

Dietary calcium intakes of urban children at risk of lead poisoning.

Dietary calcium is well known to decrease gastrointestinal lead absorption and thereby reduce the risk for lead poisoning. Because children in economically deprived urban centers are especially likely to have excessive lead exposure, we surveyed dietary calcium intakes of 314 children from the greater Newark, New Jersey, area. The areas of Newark and adjacent communities studied had been previously identified as containing significant sources of environmental lead by geographic information systems technology. An abbreviated National Cancer Institute Health Habits and History Questionnaire, modified to focus on foods high in calcium, was used to determine dietary calcium. Calcium intakes were then compared to the new Dietary Reference Intake (DRI) guidelines. The respondents were primarily the parents of African-American and Hispanic children ranging in age from 1 to 8 years, with a mean age of 3.5 years. The most recent blood lead concentration was 11.4 +/- 0.8 microg/dL (mean +/- standard error), and 48.6% had concentrations at or above the current guideline of 10 microg/dL. Quintiles of calcium intake were: 221 +/- 13; 488 +/- 9; 720 +/- 6; 885 +/- 6; and 1,389 +/- 49 mg/day. Fifty-five of 175 (31.4%) children aged 1-3 years had calcium intakes below the DRI, as did 82 of 139 (59.0%) children aged 4-8 years. The percentage of mothers reporting lactose intolerance in their children was 2.5%. The observation that the children in the highest quintile easily exceeded the DRIs for calcium suggests that urban parents who include dairy foods in their childrens' meals can provide a diet that meets the DRI guidelines. Children in the lowest quintiles are at risk of increased absorption of the environmental lead to which they are inevitably exposed, as well as other problems associated with a low intake of dietary calcium. The data suggest that both lead exposure and low dietary calcium continue to pose significant health risks to urban minority children.

Calcium, Dietary↗
PubMed1999

Effects of weight loss and exercise on the distribution of lead and essential trace elements in rats with prior lead exposure.

We studied the effects of weight loss and non-weight-bearing exercise (swimming) on blood and organ lead and essential metal concentrations in rats with prior lead exposure. Nine-week-old female Sprague-Dawley rats (n = 37) received lead acetate in their drinking water for 2 weeks, followed by a 4-day latency period without lead exposure. Rats were then randomly assigned to one of six treatment groups: weight maintenance with ad libitum feeding, moderate weight loss with 20% food restriction, and substantial weight loss with 40% food restriction, either with or without swimming. Blood lead concentrations were measured weekly. The rats were euthanized after a 4-week period of food restriction, and the brain, liver, kidneys, quadriceps muscle, lumbar spinal column bones, and femur were harvested for analysis for lead, calcium, copper, iron, magnesium, and zinc using atomic absorption spectrophotometry. Both swimming and nonswimming rats fed restricted diets had consistently higher blood lead concentrations than the ad libitum controls. Rats in the substantial weight loss group had higher organ lead concentrations than rats in the weight maintenance group. Rats in the moderate weight loss group had intermediate values. There were no significant differences in blood and organ lead concentrations between the swimming and nonswimming groups. Organ iron concentrations increased with weight loss, but those of the other metals studied did not. Weight loss also increased hematocrits and decreased bone density of the nonswimming rats. The response of lead stores to weight loss was similar to that of iron stores because both were conserved during food restriction in contrast to decreased stores of the other metals studied. It is possible that weight loss, especially rapid weight loss, could result in lead toxicity in people with a history of prior excessive lead exposure.

Animals↗
PubMed1997

Lead poisoning--one approach to a problem that won't go away.

A reduction in sources of environmental lead exposure has resulted in substantial declines in mean blood lead concentrations of all age groups in the United States. However, some segments of the population continue to have unacceptable levels of lead exposure and elevated blood lead concentrations. In addition, virtually all residents of industrialized countries have bone lead stores that are several orders of magnitude greater than those of our preindustrial ancestors. Recent studies suggest that these skeletal lead stores adversely affect health and can contribute to reduced birth weights, aggressive behavior in children, and anemia, hypertension, and kidney disease in adults. Evidence is described that demonstrates that an increase in dietary calcium consumption can reduce lead absorption and toxicity from exogenous and endogenous lead exposure. A relatively inexpensive and effective way to reduce the substantial morbidity that will result from widespread lead exposure is by fortification of a variety of foods with low levels of calcium. This approach can complement other efforts to prevent lead exposure and reduce lead toxicity.

Animals↗
PubMed1997

Lead exposure at an early age substantially increases lead retention in the rat.

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 organ concentrations 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 lead exposure 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 of blood 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 for kidney 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.

Age Factors↗
PubMed1996

Micronutrient profiles in HIV-1-infected heterosexual adults.

There is compelling evidence that micronutrients can profoundly affect immunity. We surveyed vitamin supplement use and circulating concentrations of 22 nutrients and glutathione in 64 HIV-1 seropositive men and women and 33 seronegative controls participating in a study of heterosexual HIV-1 transmission. We assayed antioxidants (vitamins A, C, and E; total carotenes), vitamins B6 and B12, folate, thiamin, niacin, biotin, riboflavin, pantothenic acid, free and total choline and carnitine, biopterin, inositol, copper, zinc, selenium, and magnesium. HIV-infected patients had lower mean circulating concentrations of magnesium (p < 0.0001), total carotenes (p = 0.009), total choline (p = 0.002), and glutathione (p = 0.045), and higher concentrations of niacin (p < 0.0001) than controls. Fifty-nine percent of HIV+ patients had low concentrations of magnesium, compared with 9% of controls (p < 0.0001). These abnormal concentrations were unrelated to stage of disease. Participants who took vitamin supplements had consistently fewer low concentrations of antioxidants, across HIV infection status and disease stage strata (p = 0.0006). Nevertheless, 29% of the HIV+ patients taking supplemental vitamins had subnormal levels of one or more antioxidants. The frequent occurrence of abnormal micronutrient nutriture, as found in these HIV+ subjects, may contribute to disease pathogenesis. The low magnesium concentrations may be particularly relevant to HIV-related symptoms of fatigue, lethargy, and impaired mentation.

Adult↗
PubMed1996

Calcification of bovine pericardium: glutaraldehyde versus No-React biomodification.

BACKGROUND: Calcific degeneration is the most frequent cause of clinical dysfunction of glutaraldehyde (GA)-pretreated bioprosthetic heart valves. The No-React (NR) process has been shown to be a promising anticalcification treatment. In this comparative study, our objective was to delineate the advantages of the NR treatment over GA. METHODS: Bovine pericardial strips pretreated with GA and NR were individually incubated in calcium phosphate solution for 21 days at 37 degrees C. The pretreated bovine pericardium then was implanted subcutaneously in rats and retrieved at 14, 21, and 35 days after-implantation. Mineral and morphologic analyses were performed on each specimen. RESULTS: The NR-treated pericardium revealed significantly reduced in vitro calcification compared with the GA-treated tissue (mean tissue calcium content 1.3 +/- 0.2 versus 5.9 +/- 0.7 micrograms/mg; p < 0.001). Mineral analysis showed progressive calcification of the GA-pretreated pericardium over the period of implantation (calcium content increasing from 49.6 +/- 9.6 micrograms/mg after 2 weeks to 134.3 +/- 9.1 micrograms/mg at 5 weeks after-implantation). The NR-treated implants had calcified significantly less (p < 0.05) at each corresponding interval. Moreover, morphologic examinations demonstrated a protracted inflammatory response in the form of giant cell and mononuclear cell infiltration associated with intrinsic collagen disruption in the GA-treated tissue; the NR-treated pericardium maintained morphologic integrity with a mild inflammatory response. CONCLUSIONS: The NR biochemical process appears not only to attenuate pericardial calcification, but also to abort the host's destructive inflammatory response to the xenograft.

Animals↗
PubMed1996

No-react detoxification process: a superior anticalcification method for bioprostheses.

BACKGROUND: Glutaraldehyde pretreatment of bioprosthetic heart valves is the major pathogenic factor in their calcific degeneration. This comparative study investigates the merit of the No-React aldehyde detoxification process as an alternative modifier of xenograft tissues. METHODS: Glutaraldehyde- and No-React-pretreated porcine aortic valve cusps were implanted subcutaneously in 6-week-old rats (n = 20). At 3, 6, and 14 weeks, randomly selected animals were sacrificed and the explants underwent mineral and morphologic analyses. Glutaraldehyde- and No-React-treated bovine pericardium and porcine aortic valve cusp were incubated in fibroblast cell culture plates. Cell viability was observed under reversed microscope at 6, 24, 48, and 96 hours. Erythrosin B dye exclusion test was used to validate percent cell death. RESULTS: Pretreatment with No-React significantly inhibited calcification of aortic cusp subcutaneous implants throughout the 14-week period (mean tissue Ca2+ content = 1.3 +/- 0.7 micrograms/mg at 14 weeks.) Glutaraldehyde-treated cusps underwent protracted calcification (Ca2+ content = 190.6 +/- 89.5 micrograms/mg; p < 0.01). Morphologic findings correlated with mineral analyses. One-hundred percent of fibroblast cells survived in the presence of No-React-treated tissue, with a growth pattern indistinguishable from control cell culture (ie, in the presence of no tissue). The cells incubated with glutaraldehyde-treated tissue showed signs of nonviability by 6 hours, with 100% cell death by 48 hours. Dye exclusion tests validated these findings. CONCLUSIONS: The No-React detoxification process completely abolishes the cytotoxicity of the xenograft tissue and inhibits calcific degeneration.

Animals↗
PubMed1996

Weight loss alters organ concentrations and contents of lead and some essential divalent metals in rats previously exposed to lead.

The loss of adipose tissue during energy restriction may be accompanied by a loss of lean body mass, including bone mass. Because most of the body lead burden is in the skeleton, we studied the effects of weight loss on the concentrations of lead in bone, blood and several organs in rats with prior but not current lead exposure. Concentrations of the essential divalent metals calcium, copper, iron, magnesium and zinc were also determined for comparison with lead. Lead-exposed rats (n = 25) were randomly assigned to one of three treatment groups: weight maintenance (WM), moderate weight loss (MWL) or substantial weight loss (SWL). For the two last-named groups, food intake was restricted for 4 wk to 70 and 40% of that of the WM group. Lead concentrations did not differ significantly (ANOVA, P > 0.05) among the three groups for blood, brain and bone. Significantly higher liver lead concentrations were observed in the SWL rats than in the WM and MWL groups. In general, organ concentrations of calcium, copper, magnesium and zinc were either lower or did not differ in the groups losing weight compared with the WM group. In contrast, organ Iron concentrations of the SWL group were higher than those of the other groups except in brain where there were no significant differences. The total liver content of lead was highest in the SWL group, but the lead content of other organs did not differ among the treatment groups. The contents of calcium, copper, magnesium and zinc generally were lower in the MWL and SWL groups than in the WM group in the liver and some of the other organs. The results demonstrate that weight loss can increase the quantity and concentration of lead in the liver, even in the absence of continued lead exposure. The data also demonstrate considerable differences among organ divalent metals in response to weight loss.

Analysis of Variance↗
PubMed1995

Dietary calcium and lead interact to modify maternal blood pressure, erythropoiesis, and fetal and neonatal growth in rats during pregnancy and lactation.

We studied 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. Pregnant Sprague-Dawley rats (n = 43) were randomly assigned to one of six treatment groups of 7-8 rats each. Half of the rats were fed diets of low (0.1%), normal (0.5%) or high (2.5%) calcium as calcium carbonate and exposed to 250 mg/L of lead in their drinking water for the duration of the pregnancy and for 1 wk of lactation. Three control groups were fed the same diets without lead exposure. Pups were studied at 1 d and 1 wk of age. Maternal and fetal blood and organ samples from the groups fed the low calcium diet had the highest lead concentrations, whereas the lowest lead concentrations were found in the groups fed the high calcium diet. Dam and pup hemoglobin concentrations, hematocrits, and body weights and lengths were reduced by lead exposure and by the high calcium diet. The latter also reduced organ iron concentrations and prevented lead-induced increases in free erythrocyte protoporphyrin. Dam systolic blood pressures during the third trimester of gestation were significantly higher in rats exposed to lead and fed the low calcium diet than in rats in the other five treatment groups. The results demonstrate that dietary calcium and lead exposure interact in rats to influence maternal blood pressure, erythropoiesis, and fetal and neonatal growth during pregnancy and lactation.

Animals↗
PubMed1994

Daily micronutrient supplements enhance delayed-hypersensitivity skin test responses in older people.

A placebo-controlled double-blind trial of the effects of daily micronutrient supplements on circulating vitamin and trace metal concentrations and delayed-hypersensitivity skin test (DHST) responses was conducted. Subjects, aged 59-85 y, were randomly assigned to 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, beta-carotene, folate, vitamin B-6, and alpha-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 to 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 older adults.

Aged↗
PubMed1992

Dietary calcium modifies concentrations of lead and other metals and renal calbindin in rats.

We studied the effects of dietary calcium on kidney, femur, testis, liver, heart and brain concentrations of lead, magnesium, iron, copper, calcium and zinc in rats exposed to lead for 1 y. Renal levels of the 28,000 Da, vitamin D-dependent, calcium-binding protein calbindin-D28K were also measured. Seventy-two weanling male Sprague-Dawley rats were randomly assigned to one of nine treatment groups. Rats were fed diets containing 0.1, 0.5 or 2.5% Ca for 52 wk and were simultaneously given either 0, 50 or 100 mg lead/L in their drinking water. Rats fed the 0.1% Ca diet had organ lead concentrations that were two- to 20-fold greater than the corresponding animals fed 0.5% Ca. Rats fed diets containing 2.5% Ca had the lowest organ lead concentrations. Despite substantial effects of diet Ca on organ lead concentrations, Ca did not significantly influence concentrations of most other divalent metals studied with the exception of kidney calcium and magnesium, testis iron, plasma ionic calcium and magnesium, and several femur metals. Kidney calcium concentrations were lower in rats fed 2.5% Ca diets than in those fed 0.1 or 0.5% Ca diets. For rats not given lead, renal calbindin concentrations were highest in rats fed 0.1% Ca, and lowest in rats fed 2.5% Ca. Lead inhibited an increase in renal calbindin in the rats fed 0.1% Ca, but paradoxically increased renal calbindin levels in animals fed 2.5% Ca.

Administration, Oral↗
PubMed1992

Effects of essential hypertension and antihypertensive medications on sweat formation.

OBJECTIVE: Sweat volume and ionic composition depend to a large extent upon the cytosolic free calcium level in secretory sweat cells and sodium and potassium transport in the reabsorptive sweat duct. Since essential hypertension and its treatment with antihypertensive drugs is likely to be associated with altered cellular ionic regulation, the objective of this research was to explore sweat formation and sweat parameters in hypertensive and normotensive subjects. DESIGN: Black and white hypertensive and normotensive subjects of both genders were studied. Essential hypertensives were on or off antihypertensive medication. METHODS: Pilocarpine iontophoresis was used to induce sweat in a 5-cm2 area of the middle forearm. Sweat was analyzed for volume, sodium and potassium concentrations. RESULTS: Females demonstrated lower sweat volumes after pilocarpine stimulation than males. Untreated hypertensive white males exhibited a higher pilocarpine-induced sweat volume and sweat sodium excretion than normotensive white males, whilst hypertensive white males on antihypertensive medication showed a lower sweat volume and sweat sodium excretion than both normotensive white males and untreated essential hypertensive white males. Although untreated hypertensive white females did not show significant alterations in sweat parameters, treated hypertensive white females exhibited lower sweat volume and sweat sodium excretion than both the normotensive and untreated essential hypertensive white females. These hypertension and drug related alterations were not present in hypertensive black males and females. CONCLUSIONS: The results are consistent with the heterogeneous nature of essential hypertension and the diversity of the response to antihypertensive therapy. They suggest that the effect of antihypertensive medication on sweat formation is mediated through cytosolic free calcium.

Adult↗
PubMed1991

Dietary lead and calcium: effects on blood pressure and renal neoplasia in Wistar rats.

We examined the potential of increased Ca in the diet to modify the effects of Pb on tissue metal concentrations, blood pressure and the incidence of renal tumours. We randomly assigned 48, 5-wk-old male Wistar rats to one of six treatment groups. They were fed a low (0.2%) or high (4.0%) Ca diet for 31 wk and given 0, 1.0 or 100 micrograms Pb/mL in drinking water. In the low Ca groups, increasing concentrations of Pb produced graded increases in mean blood pressure. Rats receiving 4.0% Ca had higher mean blood pressures than the animals fed the 0.2% Ca diet. The 4.0% Ca diet also caused renal and urinary bladder stones to develop in some rats. The high Ca diet did not prevent dose-dependent increases in tissue Pb accumulation, but it caused significant decreases in kidney Cu, femur Mg and Fe in kidney, liver and testis. Femur Mg and Fe and liver Fe concentrations were lowest in rats receiving 4.0% Ca and 100 micrograms Pb/mL. Precancerous and cancerous renal lesions occurred to the greatest extent in the rats receiving 100 micrograms Pb/mL and the high Ca diet. These results suggest that high dietary Ca does not protect against Pb-induced increases in blood pressure or Pb accumulation in tissues and may often produce nephrocalcinosis. In addition, high dietary Ca in the presence of Pb may increase the incidence of renal tumors.

Animals↗
PubMed1990

Effects of one year of supplementation with zinc and other micronutrients on cellular immunity in the elderly.

The objective of this study was to determine the effects of a year of Zn supplementation on Zn concentrations in circulating cells and on cellular immune functions in the elderly. Subjects, aged 60-89, were given a placebo, 15 mg Zn, or 100 mg Zn daily for 12 months. All subjects also received a multivitamin/mineral supplement that contained no additional Zn. Blood samples were drawn and immune functions assessed prior to and at 3, 6, 12, and 16 months after beginning Zn supplementation. Subject diets were also assessed at each visit. Dietary folate, pyridoxine, alpha-tocopherol, copper, zinc, and magnesium were consistently below recommended intakes. Although plasma Zn increased significantly in the 100 mg Zn treatment group, concentrations of Zn in erythrocytes, mononuclear cells, polymorphonuclear leukocytes, and platelets were not significantly increased by zinc supplementation. Natural killer cell activity was transiently enhanced by the 100 mg/day dose of Zn. There was a progressive improvement in delayed dermal hypersensitivity (DDH) and in lymphocyte proliferative responses to two mitogens; this may have been due to one or more components of the multivitamin/mineral supplement administered to all study subjects. The enhancement of DDH was significantly greater in the placebo group than in either zinc treatment group. Thus, zinc had a beneficial effect on one measure of cellular immune function while simultaneously having an adverse effect on another measure of cellular immunity.

Aged↗
PubMed1990

Effect of zinc-deficient diet of varying duration on intestinal disaccharidase activity in the rat.

To determine whether zinc has a specific role on weight gain and intestinal disaccharidase activity, 42 male Sprague-Dawley rats were assigned to one of seven groups (n = 6 each). These were a baseline control group (0) that was killed to analyze initial intestinal disaccharidase (sucrase and maltase) activity, a second group (A) fed a zinc-deficient diet for 1 week, a third group (B) pair-fed control for A, a fourth group (C) fed a zinc-deficient diet for 2 weeks, a fifth group (D) pair-fed control for C, a sixth group (E) fed a zinc-deficient diet for 3 weeks, and a seventh group (F) pair-fed control for E. All experimental groups received distilled deionized drinking water, whereas control groups received zinc-enriched (25 micrograms of zinc/ml) distilled deionized water. Water was given ad libitum. After killing, the mucosa of the proximal half of the small intestine was analyzed for protein and disaccharidase activity, and liver, kidney, and heart were analyzed for zinc concentration. Protein content and disaccharidase activity of the jejunal mucosa in the experiment and control groups did not differ significantly. However, animals on the zinc-deficient diet demonstrated mildly depressed growth rates that were proportional to the duration of the experiment, and significantly lower zinc concentration in the kidney in the experimental groups. The data indicate that administration of a zinc-deficient diet for up to 3 weeks did not result in significant changes in intestinal mucosa protein content or in disaccharidase activity.

Animals↗
PubMed1990

Micronutrient status and human immunodeficiency virus (HIV) infection.

This study surveyed serum concentrations of vitamins, electrolytes, and trace elements in subjects seropositive for HIV-1 by ELISA and confirmatory Western blot. Thirty subjects (26 males, 4 females) were recruited at a hospital clinic. Seventeen were classified as having mild or severe ARC (AIDS-related complex), 7 had AIDS, and 6 were asymptomatic. Eight had experienced weight loss of 10 pounds or more in the past 6 months. Most (93%) were anergic to skin test antigens. Percentages of subjects with below normal plasma concentrations include: zinc-30%, calcium-27%, magnesium-30%, carotenes-31%, total choline-50%, and ascorbate-27%. Eighty-seven percent of the subjects had at least one abnormally low value. Percentages with above normal values include: folate-37% and carnitine-37%. Some subjects with above normal values for plasma vitamins reported self-supplementation, usually with large doses. The results suggest that one or more abnormally low concentrations of the plasma micronutrients studied here are likely to be present in the majority of HIV seropositive patients.

AIDS-Related Complex↗
PubMed1989

Reducing bone lead content by chelation treatment in chronic lead poisoning: an in vivo X-ray fluorescence and bone biopsy study.

A stained-glass artist with longstanding exposure to lead presented with neuropsychiatric symptoms. He was evaluated before and after chelation treatment by the CaNa2 EDTA lead mobilization test, iliac crest bone lead measurement, and in vivo tibial X-ray fluorescence (XRF). The three methods showed a progressive fall in body lead stores during chelation therapy in association with improvement in symptoms and a fall in blood lead and zinc protoporphyrin levels. In vivo tibial XRF is a safe, rapid, and noninvasive technique for detecting excessive body lead burdens. XRF measurement of bone lead content is a practical method for monitoring the efficacy of therapy as well as for establishing the diagnosis.

Biopsy↗