Copper, zinc, cadmium, and lead in human blood from 19 locations in the United States

Rapamycin modulates pulmonary pathology in a murine model of Mycobacterium tuberculosis infection

Tuberculosis (TB) treatment regimens are lengthy, causing non-adherence to treatment. Inadequate treatment can lead to relapse and the development of drug resistance TB. Furthermore, patients often exhibit residual lung damage even after cure, increasing the risk for relapse and development of other chronic respiratory illnesses. Host-directed therapeutics are emerging as an attractive means to augment the success of TB treatment. In this study, we used C3HeB/FeJ mice as an experimental model to investigate the potential role of rapamycin, a mammalian target of rapamycin inhibitor, as an adjunctive therapy candidate during the treatment of Mycobacterium tuberculosis infection with moxifloxacin. We report that administration of rapamycin with or without moxifloxacin reduced infection-induced lung inflammation, and the number and size of caseating necrotic granulomas. Results from this study strengthen the potential use of rapamycin and its analogs as adjunct TB therapy, and importantly underscore the utility of the C3HeB/FeJ mouse model as a preclinical tool for evaluating host-directed therapy candidates for the treatment of TB.

The relationship between marginal bone loss and serum zinc levels

Serum was analyzed for zinc in 51 patients of varying age and with varying degrees of alveolar bone loss as recorded on roentgenograms. There was a reversed correlation between marginal alveolar bone loss and serum zinc levels. The observations are discussed in relation to the physiological functions of zinc.

Promotion of cultured vascular smooth muscle cell proliferation by low levels of cadmium

Cadmium is a toxic heavy metal which has been shown to be a possible risk factor of atherosclerosis in epidemiological and experimental studies. Since intimal hyperplasia in vascular tissue is an important component of atherosclerosis, we examined the effect of cadmium on the proliferation of vascular smooth muscle cells cultured in a serum-free medium. It was found that cadmium at 100 nM or less can increase the incorporation of [3H]thymidine into the acid-insoluble fraction of growing bovine and rabbit aortic smooth muscle cells but not of growing bovine aortic endothelial cells. Although vascular smooth muscle cells are sensitive to cadmium cytotoxicity, no increase in the leakage of lactate dehydrogenase from the cells was caused by the metal at 200 nM or less in bovine aortic smooth muscle cells. Intracellular accumulation of radioactive calcium in bovine aortic smooth muscle cells was significantly increased by cadmium. It was therefore suggested that low levels of cadmium may promote the proliferation of vascular smooth muscle cells through intracellular calcium-dependent signalling pathway. The present study supports the hypothesis that cadmium can be a risk factor of atherosclerosis through dysfunction of vascular smooth muscle cells as well as vascular endothelial cells under certain conditions.

Lead and cadmium levels in violent criminals

Two groups of violent incarcerated male criminals and 30 nonviolent criminals were compared for element content of hair by atomic absorption spectroscopy. Groups did not differ in age, socioeconomic status, or months institutionalized. The groups did differ significantly in lead and cadmium levels. The importance of cadmium in affecting reactivity to stimuli is discussed.

Main and interaction effects of metal pollutants on visual-motor performance

This study investigated possible relationships of metal levels and metal combinations with children's visual-motor performance. Hair-metal concentrations of lead, arsenic, methylmercury, cadmium, and aluminum were determined in 69 randomly selected elementary age children. They were also administered the Bender Visual-Motor Gestalt Test. Parents of subjects were interviewed to control for confounding variables that might affect cognitive development. Regression data indicated that increases in aluminum and the interaction of aluminum with lead were significantly related to decreased visual-motor performance. Because metal levels and metal combinations previously thought harmless may be associated with visual-motor deficits, a continuing reexamination of metal poisoning concentrations is needed.

Trace elements in human body fluids and tissues

Published figures for trace element concentrations in body fluids and tissues of apparently healthy subjects are widely divergent. For a considerable time, the apparent disparities were readily ascribed to biological sources of variation such as age, sex, dietary habits, physiological conditions, environmental exposure, geographical circumstances, or similar influences. Growing evidence, however, suggests that this interpretation may be seriously questioned in numerous instances. First, values obtained in reference materials leave no doubt that some previous studies must have been subject to gross analytical inaccuracies. Second, it has now been thoroughly documented that inadequate sample collection and manipulation may drastically distort the intrinsic trace element content of biological matrices. This review scrutinizes data reported by a number of investigators. In an effort to settle the currently flourishing confusion, critically selected reference values are set forth for trace element levels in human blood plasma or serum, packed blood cells, urine, lung, liver, kidney, and skeletal muscle tissue.

Placental transfer of heavy metals in normal pregnant Japanese women

To investigate the interrelation of heavy metals and the influence on next generation, total mercury and methylmercury, lead, cadmium, manganese, copper, zinc, and iron were determined in the maternal blood, placenta, umbilical cord, and umbilical cord blood. Samples were collected at delivery from 231 pregnant women who were living in the city of Nagoya, located in the central district of Japan, during 1974 and 1978. Total mercury and methylmercury, cadmium, and iron were higher in cord blood than in maternal blood, whereas copper and zinc were lower. Significant positive correlations were observed between maternal and cord blood with regard to total mercury and methylmercury, lead, cadmium, and manganese contents. Significant correlations were also observed between many pairs of metals, particularly in umbilical cord and its blood.

Effects of low levels of cadmium and lead on cognitive functioning in children

Hair cadmium and lead content were related to intelligence tests, motor impairment assessments, and school achievement scores from 149 children aged 5 to 16 yr enrolled in rural Maryland public school systems. Hair cadmium and lead were significantly correlated with both intelligence scores and school achievement scores, but not motor impairment scores. Significant relations with I.Q. were obtained after regressing out demographic factors and were observed, even in children within a normal I.Q. range. Evidence of different effects of cadmium and lead on cognitive development was obtained. Hierarchical regression analyses suggest that cadmium has a significantly stronger effect on verbal I.Q. than does lead and that lead has a stronger effect on performance I.Q. than does cadmium.

Copper and zinc in human serum in Norway. Relationship to geography, sex and age

Serum samples were collected from the adult population, age groups from 20 to 54 years, in 11 different Norwegian municipalities and analysed for zinc and copper by atomic absorption spectroscopy. Significant differences were found between several of the municipalities when the mean concentration of zinc in serum in 200 randomized samples were compared, with only two municipalities being different for copper. The values for zinc ranged from 13.8 to 18.3 mumol/l and copper varied between 16.3 and 19.2 mumol/l. An age related increase in the copper concentration was evident in the male population, and age-adjusted means showed a slight, but significantly higher serum copper concentration in females (18.4 mumol/l) than in males (16.5 mumol/l). For zinc the opposite sex-relationship was indicated with the highest values in males, 15.8 compared to 15.1 mumol/l in serum from females. No significant correlations were found between the concentrations of zinc and copper in serum. In all age groups of women, however, a small negative correlation was found giving a significant tendency.

Serum zinc levels in patients with basal-cell carcinoma

Basal-cell carcinoma is a malignant epithelial neoplasm that arises from the germinative cells of the epidermis and its appendages. Various causative factors have been implicated in its pathogenesis. In recent years, it has become increasingly apparent that alterations in serum zinc concentration may relate to neoplastic diseases. The objective of this study was to determine whether or not a relationship exists between abnormal serum zinc levels and basal-cell carcinomas. The data indicate that a statistically significant elevation in mean serum zinc levels is associated with this neoplasm. This may, however, not be of clinical significance because of variation in environmental or statistical sampling factors.

[Lead levels and delta- aminolevulinic acid dehydratase activity in the blood of the population of Greater São Paulo, Brazil]

Foram feitas determinações de chumbo e atividade da delta-ALAD no sangue de 3 amostras populacionais da Grande São Paulo (Brasil). Um grupo (A) de área de escassa exposição ambiental ao chumbo, um grupo (B) exposto principalmente a fontes móveis de emissão de chumbo e um grupo (C) vizinho a uma indústria de recuperação de chumbo. Cada grupo foi subdividido conforme sexo e hábito de fumar. A plumbemia do grupo C (20,5 µg/100 ml) foi significantemente maior que as dos grupos A (11,2 µg/100 ml) e B (12,4 µg/100 ml). As correlações entre plumbemia e atividade da delta-ALAD, plumbemia e sexo e plumbemia e hábito de fumar foram investigadas.

Lead, cadmium, and mercury tissue residues in healthy swine, cattle, dogs, and horses from the midwestern United States

A survey was conducted in 1975-1976 to determine the background levels of lead, cadmium, and mercury tissues of healthy swine, cattle, dogs, and horses from the midwestern United States. Blood, muscle, liver, and kidney were assayed from cattle and swine slaughtered at federal meat inspection plants and in dogs and horses obtained from local pounds and sales barns. A total of 959 samples for lead, 972 samples for cadmium, and 827 samples for mercury were analyzed. The maximum muscle lead concentration was less than 0.10 ppm in dogs and horses. Fourteen percent of the cattle muscle samples contained between 0.16 and 0.34 ppm lead. The blood lead concentration was generally lower than 0.10 ppm in cattle, swine and horses; however, in dogs 44% of the blood lead values were between 0.11 and 0.37 ppm. The liver and kidney lead content was generally less than 0.50 ppm in all species, and the maximum lead content detected in either tissue was less than 2.0 ppm. Elevated tissue levels of cadmium were observed in horses as compared to other species. While the maximum muscle cadmium content in cattle, swine, and dogs rarely exceeded 0.05 ppm, levels in excess of 0.06 ppm were found in all the 19 horse muscle samples. Blood cadmium levels in all species were near or below the detection limit of 0.005 ppm. The median cadmium concentration in liver and kidney was below 0.2 and 0.6 ppm, respectively, in cattle, swine, and dogs. However, in horses the median concentration was 20 times greater in liver and 4 times higher in kidney. The mercury concentrations in muscle and blood of all species were near or below the detection limit of 0.02 ppm. The median concentrations of mercury in liver and kidney, respectively, were: 0.02 ppm each in swine and cattle; 0.02 ppm and 0.05 ppm in dogs; and 0.12 ppm and 0.72 ppm in horses. The results suggest that exposure of animals to dietary or environmental lead, cadmium, and mercury in the midwestern United States is not significant. The specific cumulation of cadmium and mercury in tissues of horses suggests the need to explore the role these metals play in selective biological processes.

Cancer mortality correlation studies--IV: associations with dietary intakes and blood levels of certain trace elements, notably Se-antagonists

The per-capita intakes of zinc, cadmium, copper and of chromium were estimated from food consumption data in 28 countries and were found to correlate directly with the age-corrected mortalities from cancers of intestine, prostate, breast, leukemia, skin and of other organs, suggesting that the anticarcinogenic effect of selenium is counteracted by other trace elements. Similarly calculated dietary intakes of manganese are inversely correlated, particularly with the mortalities from cancer of pancreas, an organ normally known to contain high concentrations of this element. Arsenic intakes correlate inversely with the male lung cancer mortalities. A number of other direct and inverse associations were observed which suggest that trace elements in the human diet may hav both benign and adverse effects on tumor development. The zinc concentrations in whole blood collected from healthy donors in the U.S. correlate directly with regional mortalities from cancers of intestine, breast and of other sites. The origin of these associations is discussed primarily in terms of the seleium-antagonistic effect of zinc and of some of the other elements considered. Results of animal experiments and of other studies are cited which support hypotheses that link human cancer development to possible deficiencies or excesses in the dietary trace element intakes.

Balance study of twenty trace elements during total parenteral nutrition in man

1. Balances of twenty trace elements (silver, arsenic, gold, bromine, cadmium, cobalt, chromium, caesium, copper, iron, mercury, lanthanum, molybdenum, rubidium, antimony, scandium, selenium, samarium, tungsten and zinc) have been determined in four male patients during total parenteral nutrition incliding fat emulsion and a special solution for addition of Fe, Zn, manganese, Cu, fluorine and iodine, besides calcium and magnesium, to the infusion solutions. 2. The analyses for trace elements were made with the aid of an ion-exchange technique based on neutron activation, and combined with subsequent gamma spectrometry. 3. The intended intravenous supply of trace elements correspond approximately to the analysed supply. However, all the other trace elements determined were found to be unintentionally administered in small amounts. 4. There was a substantial retention of Fe. Other elements retained were Ag, Co, Cr, Cu, Sb, Sc, and W. 5. Particularly Br and Rb were lost by the patients, but negative balances were also found for As, Au, Cd, Cs, Mo, Se and Zn. However, Zn was retained by one patient with short bowel syndrome. 6. The serum concentrations of thirteen (Ag, Br, Co, Cs, Cu, Fe, Hg, Mo, Rb, Sc, Se, W and Zn) of the trace elements were found to have some decrease during the period of total parenteral nutrition, mostly in accordance with the corresponding balance values, Fe, in particular, was found to have the derectional change in concentration. 7. The administration of trace elements is recommended in long-term total parenteral nutrition.

Influence of cadmium and other trace metals on human alpha1-antitrypsin: an in vitro study

The effect of trace metals on plasma alpha1-antitrypsin was studied in vitro by adding known concentrations of trace metals, either alone or in combination, to plasma. Cadmium was the only trace metal that reduced the concentration of alpha1-antitrypsin and depressed the trypsin inhibitory capacity. No such effects were found with divalent lead, mercury, nickel, iron, and zinc ions. The present study appears to offer a plausible explanation for the emphysema that occurs in industrial workers exposed to cadmium.

Determination of lead and cadmium in milk with modern analytical methods

Methods to determine lead and cadmium at the low mug/kg-level in milk were investigated. Methods tested were differential-pulse anodic-stripping voltammetry (DPASV) and flameless atomic-absorption spectrophotometry (FAAS). Under the circumstances in which these methods were used, the analytical procedure based on DPASV was the most sensitive, with an estimated detection limit of about 0.2 mug/1 for lead and cadmium in liquid milk. The pretreatment of the milk samples before the DPASV-analysis included: freeze-drying, ashing in a muffle furnance at 550 degree C and finally dissolution of the ash in 0.1 M-hydrochloric acid. The recoveries of known amounts of lead and cadmium added to milk were 95 and 59%, respectively. A survey of the contents of lead and cadmium in the Swedish manket milk was performed. This investigation showed that the average lead content in Swedish market milk was 2.0 mug/1, with a standard deviation of 0.5 mug/1. The cadmium content was below 0.2 mug/1 in all samples analyzed.

Inhibition of the genesis of spontaneous mammary tumors in C3H mice: effects of selenium and of selenium-antagonistic elements and their possible role in human breast cancer

The inhibitory effect of selenium on the genesis of spontaneous mammary tumors in C3H mice is statistically significant even at toxic levels of selenium (5 and 15 ppm of Se in form of selenite added to the supply water), no evidence for stimulation of tumor growth by selenium has been obtained. Arsenite lowers the tumor incidence at higher dosage (80 ppm of As in supply water) as well, but animals developing tumors under these conditions demonstrate significantly enhanced tumor growth rates. The addition of subtoxic concentrations of zinc (200 ppm in form of ZnCl2) to supply water containing 5 ppm of Se abolishes the cancer-protecting effect of selenium. The latter result is of possible importance with respect to the human breast cancer mortality experience: The calculated dietary zinc intakes of average adults in 28 countries correlate with the female age-corrected mortalities from breast cancer directly, with P less than 0.005. The zinc concentrations in whole blood from donors in different parts of the U.S.A. are also directly correlated with the female breast cancer mortalities.

Elemental analysis of honey as an indicator of pollution. Forty-seven elements in honeys produced near highway, industrial, and mining areas

Nineteen samples of honey taken from grocery shelves, near zinc mines, adjacent to an industrial area, and near a major highway, and one sample collected in 1899 were subjected to spark source mass spectrometry to determine the concentration of most of 47 elements in the honey. Certain samples of honey produced by bees in the vicinity of the New York State Thruway appeared to contain elevated levels of certain elements known to be emitted by traffic, such as aluminum, barium, calcuim, copper, magnesium, nickel, palladium, and silicon, but the true source of these elements was uncertain. Honey that had come into contact with metal containers in processing contained the greatest amounts of zinc and tin.

Blood lead levels in a Welsh rural community

In a study of the blood lead levels of 626 healthy blood donors no differences were found between men and women, but there was a significant increase with age. Resident donors had a higher blood lead than students, and the level in residents increased with living in the Aberystwyth area up to about 20 years. The levels in the students did not increase with residence in Aberystwyth. No differences were found in the blood lead of donors living in different wards of Aberystwyth and none between the blood lead of donors living in the rural area and those in the town. Almost half of the local resident donors had a level above the "normal" range.