Localization and toxic effects of cadmium, copper, and uranium in azolla

The storage and distribution of copper, cadmium, and uranium and their effects on ionic contents in roots and shoots of Azolla filiculoides has been studied by x-ray microanalysis. The relative content of copper was eightfold higher in the root than in the shoot, suggesting low mobility of this metal in Azolla plant. Cadmium relative content in the shoot was similar to its content in the root, hence its mobility was relatively high. The absence of significant uranium quantities in the shoot and its relative high content in the root suggest the immobility of this metal from Azolla root. Cadmium formed precipitates with phosphate and calcium in xylem cells of the shoot bundle and caused a two- to threefold increase in the content of phosphate in the root. Uranium in roots and cadmium in shoots were associated with calcium. All three treatments caused losses of potassium, chloride, and magnesium from Azolla roots. Accumulation of heavy metals in Azolla and their mobility from the root to the shoot can be correlated with damage caused by the loss of essential nutrients.     

Levels of Heavy Metals and Essential Minerals in Hair Samples of Children with Autism in Oman: a Case–Control Study

Toxic levels of heavy metals and low levels of essential minerals have been suggested to play a critical role in the pathogenesis of autism spectrum disorders (ASD). This study documents the levels of heavy metals and essential minerals in hair samples of children with ASD in Muscat, the urbanized capital of Oman, Muscat. The study included 27 children with ASD and 27 matched non-ASD controls. Parental interviews were held and dietary intake questionnaires completed in conjunction with the collection of hair samples. Analysis of heavy metals and essential minerals was carried out by inductively coupled plasma mass spectrometry. Chi-square analysis and non-parametric Fisher’s exact tests were used to assess statistical significance. Children with ASD had significantly higher levels of all 11 analyzed heavy metals in their hair samples (P?<?0.05), ranging from 150 to 365 % of control levels. ASD children also had significantly higher levels of essential minerals sulfur, sodium, magnesium, potassium, zinc, and iron, but lower levels of calcium and copper in their hair samples. This study corroborates data from previous studies in different parts of the world indicating the presence of elevated levels of heavy metals and selective depletion of essential minerals in the hair of children with ASD.     

Essential metals in tissues and tumor of inbred C57BL/6 mice during the infective cycle of Lewis lung carcinoma

The variation of tissue copper, zinc, iron, calcium, magnesium, potassium and sodium content of inbred C57BL/6 mice during the infective cycle of Lewis lung carcinoma have been studied. Tissue calcium, magnesium, potassium and sodium concentrations were well maintained during the infective cycle, probably because of their large dietary availability, copper, zinc and iron, however, showed a progressive decrease in their tissue concentrations. Liver zinc increased in parallel with the metastasising process. The important decrease in tissue iron observed agress with the characterized hypoferric response to infection. However, when the losses of metals were considered on a global organism basis, the loss of iron was not paralleled by an increase in tumor iron, but a global loss was observed. The hypoferric response did not deter tumor growth, as this was able to carry on its development with significantly decreasing neoplastic tissue iron content. The only metal actively concentrated by the tumoral mass was sodium.     

An integrating atomic absorption spectrophotometer for ultramicroanalysis of metals

An integrating atomic absorption spectrophotometer for ultramicroanalysis of metals is described. The apparatus is intended mainly for determination of calcium and magnesium but can also be used for sodium, potassium, lithium, and copper, among other metals. Analyses of sample volumes as small as about 1 nl, containing calcium and magnesium in amounts as low as 10^?11 and 10^?12 moles, respectively, have been made. In analyses of samples containing 4·10^?12 moles of magnesium a coefficient of variation of ±5% was obtained.The principles of the apparatus are the same as for a conventional atomic absorption spectrophotometer apart from the fact that an electronic integrator with a rapid response has been used as the recording system. For atomization of the sample a hydrogen-air flame has been used in combination with a flame adapter. The sample is introduced into the flame by means of a small loop on a platinum-iridium filament.     

Effect of cations,including heavy metals,on cadmium uptake by Lemna polyrhiza L.

Cations, including calcium, magnesium, potassium, sodium, copper, iron, nickel and zinc, inhibited (up to 40%) extracellular binding and intracellular uptake of cadmium by Lemna polyrhiza in solution culture. Test plants showed a high capacity of extracellular cadmium binding which was competitively inhibited by copper, nickel and zinc; however, calcium, magnesium and potassium caused non-competitive inhibition. Iron and sodium increased K _m and decreased V _max, thereby causing mixed inhibition of extracellular binding. Intracellular cadmium uptake displayed Michaelis-Menten kinetics. It was competitively inhibited by calcium, magnesium, iron, nickel and zinc. Monovalent cations (sodium and potassium) caused non-competitive and copper caused mixed inhibition of intracellular cadmium uptake. Thus, high levels of cations and metals in the external environment should be expected to lower the cadmium accumulation efficiency of L. polyrhiza.     

Serum Macroelement and Microelement Concentrations in Patients with Polycystic Ovary Syndrome: a Cross-Sectional Study

Polycystic ovarian syndrome (PCOS) is one of the most common endocrine diseases. However, its pathogenesis is unclear. We aim to explore the potential relationships between serum macroelements/microelements and PCOS. A total of 1137 women were involved in the current study. PCOS was defined according to ESHRE/ASRM, and complete blood samples were collected. Serum macroelements (calcium and magnesium) and microelements (copper, zinc, and iron) were assayed through atomic absorption spectrophotometry. PCOS patients had significantly higher copper concentrations than patients without PCOS (P < 0.001). By contrast, PCOS patients had lower serum calcium levels than patients without PCOS (P < 0.001). No significant differences were observed in the levels of serum zinc, magnesium, and iron between PCOS and non-PCOS patients. PCOS patients with acne had higher magnesium levels than those without acne (P = 0.020), and PCOS patients with hirsutism had lower magnesium levels than those without hirsutism (P = 0.037). High serum copper and low calcium levels may be correlated with PCOS. Magnesium concentrations are correlated with acne and hirsutism in PCOS patients. These results provide clues to explore the mechanism of PCOS and guidance for element treatments in PCOS patients.     

THE INFLUENCE OF DIETARY CALCIUM ON THE TISSUE DISTRIBUTION OF Cu, Zn, Mg & P AND HISTOLOGICAL CHANGES IN THE DIGESTIVE GLAND CELLS OF THE SNAIL ACHATINA FULICABOWDICHM

Dietary calcium had a varying effect on the concentration ofother metals located in the tissues and excreted in the faeces.Faecal phosphate, copper and zinc concentrations decreased withincreased dietary calcium but showed a peak of excretion 10–12weeks after the beginning of the experiment, while the totalamounts of the studied elements lost in the faeces increased.Phosphate values in the digestive gland of snails on calcium-supplementeddiets were lower than metal values found in control snails.Although the digestive gland magnesium concentrations were alwayslower and copper levels higher than the snails on the omnivorousdiet, the trend was for a decrease in tissue magnesium and copperwith increased calcium in the diet. In foot tissue, the trendwas towards a decrease in Mg with decreased dietary calcium.The zinc concentration in the digestive gland and foot of snailson the omnivorous diet was not different from the zinc levelsin snails on the three highest calcium-supplemented diets. Itis suggested that high levels of dietary calcium might act asan environmental stressor characterised by changes in the morphologyand histo-chemistry of the digestive tubules. (Received 14 August 1991; accepted 10 October 1991)     

Transition metal binding to cod otolith proteins

Otolith microchemistry can be very useful in identifying fish populations and reconstructing fish movements. Recent attempts have been made to evaluate otoliths as proxies of ambient levels of transition metals, but findings have been inconsistent. Some of the difficulty with obtaining a definitive answer stems from an incomplete understanding of the biological control of transition metal speciation in otoliths. Metals may be incorporated as part of the calcium carbonate phase, trapped in interstitial spaces within the crystal, or associated with the protein matrix. Metal binding to the protein phase may be inferred from its structural and biochemical properties but has not been observed previously. Inherent difficulties with the extraction of metal-binding proteins in their native state from the calcium carbonate phase make them extraordinarily difficult to measure. We have developed a method that facilitates the extraction of otolith proteins without total disruption of transition metal binding. Chelating agents such as EDTA, used in the decalcification of otoliths, can demetallate the proteins if allowed to reach equilibrium; however, if the reaction is halted prior to equilibration, intact metal-protein complexes can be obtained. Using such an approach, we have confirmed the presence of copper and zinc in the soluble portion of the protein matrix of cod otoliths, and we have established that between 70% and 100% of copper and 40% to 60% of zinc found in whole otoliths are associated with the soluble part of the protein matrix. Manganese was not observed to be associated with the protein, indicating that it is either weakly bound or that no binding is present. Our results, combined with an understanding of the biological control of these metals, suggest that otoliths are not likely to be reliable indicators of copper and zinc exposure, but they may provide useful insight into fish growth and physiological development.     

EDTA chelation effects on urinary losses of cadmium, calcium, chromium, cobalt, copper, lead, magnesium, and zinc

The efficacy of a chelating agent in binding a given metal in a biological system depends on the binding constants of the chelator for the particular metals in the system, the concentration of the metals, and the presence and concentrations of other ligands competing for the metals in question. In this study, we make a comparison of the in vitro binding constants for the chelator, ethylenediaminetetraacetic acid, with the quantitative urinary excretion of the metals measured before and after EDTA infusion in 16 patients. There were significant increases in lead, zinc, cadmium, and calcium, and these increases roughly corresponded to the expected relative increases predicted by the EDTA-metal-binding constants as measured in vitro. There were no significant increases in urinary cobalt, chromium, or copper as a result of EDTA infusion. The actual increase in cobalt could be entirely attributed to the cobalt content of the cyanocobalamin that was added to the infusion. Although copper did increase in the post-EDTA specimens, the increase was not statistically significant. In the case of magnesium, there was a net retention of approximately 85% following chelation. These data demonstrate that EDTA chelation therapy results in significantly increased urinary losses of lead, zinc, cadmium, and calcium following EDTA chelation therapy. There were no significant changes in cobalt, chromium, or copper and a retention of magnesium. These effects are likely to have significant effects on nutrient concentrations and interactions and partially explain the clinical improvements seen in patients undergoing EDTA chelation therapy.     

Dental Phenotype in Jalili Syndrome Due to a c.1312 dupC Homozygous Mutation in the CNNM4 Gene

Jalili syndrome denotes a recessively inherited combination of an eye disease (cone-rod dystrophy) and a dental disorder (amelogenesis imperfecta), which is caused by mutations in the CNNM4 gene. Whereas the ophthalmic consequences of these mutations have been studied comprehensively, the dental phenotype has obtained less attention. A defective transport of magnesium ions by the photoreceptors of the retina is assumed to account for the progressive visual impairment. Since magnesium is also incorporated in the mineral of dental hard tissues, we hypothesized that magnesium concentrations in defective enamel resulting from mutations in CNNM4 would be abnormal, if a similar deficiency of magnesium transport also accounted for the amelogenesis imperfecta. Thus, a detailed analysis of the dental hard tissues was performed in two boys of Kosovan origin affected by Jalili syndrome. Retinal dystrophy of the patients was diagnosed by a comprehensive eye examination and full-field electroretinography. A mutational analysis revealed a c.1312 dupC homozygous mutation in CNNM4, a genetic defect which had already been identified in other Kosovan families and putatively results in loss-of-function of the protein. The evaluation of six primary teeth using light and scanning electron microscopy as well as energy-dispersive X-ray spectroscopy showed that dental enamel was thin and deficient in mineral, suggesting a hypoplastic/hypomineralized type of amelogenesis imperfecta. The reduced mineral density of enamel was accompanied by decreased amounts of calcium, but significantly elevated levels of magnesium. In dentin, however, a similar mineral deficiency was associated with reduced magnesium and normal calcium levels. It is concluded that the c.1312 dupC mutation of CNNM4 results in mineralization defects of both enamel and dentin, which are associated with significantly abnormal magnesium concentrations. Thus, we could not disprove the hypothesis that a disrupted magnesium transport is involved in the development of the dental abnormalities observed in Jalili syndrome.     

Heavy metal tolerance of marine phytoplankton. III. Combined effects of copper and zinc ions on cultures of four common species

The combined effects of copper and zinc ions on the growth of three marine diatoms and one dinoflagellate in culture have been studied. The two metals were found to act synergistically to all algae except Phaeodactylum tricornutum Bohlin. With this species an antagonistic effect was observed. Addition of zinc ions reduced the inhibition of growth caused by the more toxic copper ions. Zinc toxicity to this alga increased at low concentration of magnesium, indicating a common route for divalent metal ions in general.     

Cerium Regulates Expression of Alternative Methanol Dehydrogenases in Methylosinus trichosporium OB3b

Methanotrophs have multiple methane monooxygenases that are well known to be regulated by copper, i.e., a “copper switch.” At low copper/biomass ratios the soluble methane monooxygenase (sMMO) is expressed while expression and activity of the particulate methane monooxygenase (pMMO) increases with increasing availability of copper. In many methanotrophs there are also multiple methanol dehydrogenases (MeDHs), one based on Mxa and another based on Xox. Mxa-MeDH is known to have calcium in its active site, while Xox-MeDHs have been shown to have rare earth elements in their active site. We show here that the expression levels of Mxa-MeDH and Xox-MeDH in Methylosinus trichosporium OB3b significantly decreased and increased, respectively, when grown in the presence of cerium but the absence of copper compared to the absence of both metals. Expression of sMMO and pMMO was not affected. In the presence of copper, the effect of cerium on gene expression was less significant, i.e., expression of Mxa-MeDH in the presence of copper and cerium was slightly lower than in the presence of copper alone, but Xox-MeDH was again found to increase significantly. As expected, the addition of copper caused sMMO and pMMO expression levels to significantly decrease and increase, respectively, but the simultaneous addition of cerium had no discernible effect on MMO expression. As a result, it appears Mxa-MeDH can be uncoupled from methane oxidation by sMMO in M. trichosporium OB3b but not from pMMO.     

Mineral nutrition of cacao (Theobroma cacao L.)

Summary Two experiments on cacao seedlings grown in sand culture are described, the first of which was concerned with variations in the levels of nitrogen, phosphorus, potassium, calcium, magnesium and sulfur (the macronutrient experiment) and the second dealing with variations in the levels of iron, copper, zinc, boron, manganese, and molybdenum (the micronutrient experiment).Many of the deficiency symptoms obtained were similar to those reported in the literature and they have not been described again. However, additional information is provided for symptoms of phosphorus, potassium, calcium, iron, manganese, copper, boron, and molybdenum deficiencies.The effects of all treatments on the dry weights of leaves, stems, and roots are presented. The effects of the macronutrient treatments on the levels of nitrogen, phosphorus, potassium, calcium, and magnesium in the leaves of eight month old plants and the effects of micronutrient treatments on the levels of nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese, copper, zinc, boron, molybdenum, sodium, and aluminium in the leaves of eleven-month-old plants are presented and discussed.     

Stimulated and Unstimulated Saliva Levels of Calcium and Magnesium in Giardiasis

Giardia lamblia causes malabsorption. The aim of this study was to evaluate serum and saliva calcium and magnesium levels in patients with giardiasis. Thirty patients with giardiasis as a case and 30 person without giardiasis as a control group were enrolled. The stimulated and unstimulated whole saliva and serum calcium and magnesium levels were assayed by Arsenazo reaction and xylidyl blue complex methods, respectively. Mean calcium and magnesium level was low in serum and stimulated saliva of case group than that of controls. However, they were higher in the unstimulated saliva of the case group. It is suggested that patients suffering from giardiasis have low calcium and magnesium levels, and they lose the most of calcium and magnesium by saliva during unstimulated condition.     

The phytiatric influence of treatments with cation exchangers in a soil,contaminated with heavy metals,on the growth and the mineral composition ofZea mays L. andPhaseolus vulgaris L.

Summary The application of selectively working cation exchangers in a soil contaminated with heavy metals such as lead, copper and zinc caused a significant increase of the plant weight and the plant length of maize. The calcium and magnesium percentage of the plant has clearly been influenced by the cation exchangers, whereas the potassium content was especially influenced by an additional fertilization and not by the cation exchangers. The sodium and phosphate content varied very little, the same holds for the manganese and the iron content. Almost no significant differences have been noticed with regard to the total amount of chlorophyll.Similar treatments with cation exchangers highly influence the growth of beans, comparable after two consecutive cultures by means of the plant weight and the cumulative yields. This reaction on the input of cation exchangers in a contaminated soil is much more outspoken when compared to a monocotyledon. A significant positive correlation between the cumulative yield and the pH of the soil has also been noticed.     

Electrolyte composition of cow and calf tissues in health and in acute digestive disturbances]

Sodium, potassium, calcium, magnesium, manganese, zinc and chloride contents in the blood plasma of calves at parturition have been established to correspond to their levels in blood of cows during their calving period. Iron and inorganic phosphorus contents in calves blood plasma appeared to increase and copper content to be lower in this period as compared to postnatal period. By the third day of postnatal ontogenesis sodium concentration in calves blood decreased, copper level increased and the rest indices of water-salts metabolism in calves and adult animals were alike. Digestion disturbances in the calves were accompanied by changes in levels and magnitude of Na+/K+ ratio, magnesium, iron, copper, manganese and zinc contents in blood, liver and kidneys as well as Ca++/Pi ratio in mitochondria and cytosol of liver and jejunum mucose layer cells in comparison with clinically healthy animals.     

Cation binding properties of calretinin, an EF-hand calcium-binding protein.

Calretinin (CR) is a neuronal EF-hand protein previously characterized as a calcium (micromolar affinity) binding protein. CR-containing neurons are spared in some neurodegenerative diseases, although it is as yet unconfirmed how CR plays an active role in this protection. Higher levels of some metal cations (e.g. copper and zinc) are associated with these diseases. At the same time, metals such as terbium (NMR and fluorescence) cadmium (NMR) and manganese (EPR) serve as useful calcium analogues in the study of EF-hand proteins. We survey the binding of the above-mentioned metal cations that might affect the structure and function of CR. Competitive 45Ca2+-overlay, competitive terbium fluorescence and intrinsic tryptophan fluorescence are used to detect the binding of metal cations to CR. Terbium and copper (half-maximal effect of 15 microM) bind to CR. Terbium has a similar or greater affinity for the calcium-binding sites of CR than calcium. Copper quenches the fluorescence of terbium-bound CR, and CR tryptophan residues and competes weakly for 45Ca2+-binding sites. Cadmium, magnesium, manganese and zinc bind less strongly (half-maximal effects above 0.1 mM). Therefore, only terbium appears to be a suitable analytical calcium analogue in further studies of CR. The principal conclusion of this work is that copper, in addition to calcium, might be a factor in the function of CR and a link between CR and neurodegenerative diseases.     

Effect of pH on the speciation and solubility of divalent metals in human and bovine milks

Computer models estimated the ligand speciation and solubility of calcium, magnesium, zinc, and copper over a pH range for low molecular weight fractions characteristic of either human or bovine milks. Above pH 4 calcium is the only metal predicted to precipitate. Most of the remaining soluble calcium, magnesium, and zinc should be complexed with citrate. The solubility of calcium, magnesium, and zinc in human and bovine milks was measured experimentally from pH 2 to 7. The solubility of all three metals decreased as the pH increased. Calcium and zinc were soluble over a narrower pH range in bovine milk than in human milk. Increasing the levels of either calcium or inorganic phosphate alone in decaseinated human milk did not affect the solubility of zinc, but when both calcium and inorganic phosphate were added at levels comparable to bovine milk the solubility of zinc decreased at the higher pH's. The decreased solubility of zinc in skimmed milks in pH's characteristic of the small intestine is likely due to coprecipitation of zinc with calcium phosphate--a reaction not predicted for milk systems from known chemical solubility product data.     

The Correlation of Serum Trace Elements and Heavy Metals with Carotid Artery Atherosclerosis in Maintenance Hemodialysis Patients

Changes in essential trace elements and heavy metals may affect the atherosclerotic state of patients on maintenance hemodialysis (HD). The aim of the study was to evaluate the relation between the serum levels of some trace elements and heavy metals (iron, zinc, manganese, copper, magnesium, cobalt, cadmium, lead, and copper/zinc ratio) and carotid artery intima-media thickness (CIMT) in HD patients. Fifty chronic HD patients without known atherosclerotic disease and 48 age- and sex-matched healthy individuals were included in the study. The serum levels of trace elements (iron, zinc, manganese, copper, and magnesium) and heavy metals (cobalt, cadmium, and lead) were measured by Atomic Adsorption Spectrophotometer (UNICAM-929). CIMT was assessed by carotid artery ultrasonography. The serum levels of iron, zinc, and manganese were lower; levels of copper, magnesium, cobalt, cadmium, lead, and copper/zinc ratio were higher in HD patients compared to controls. CIMT in HD patients were higher than the control group (0.64?±?0.11 vs 0.42?±?0.05, p?相似文献   

Hair Iron and Other Minerals’ Level in Breast Cancer Patients

Little is known about hair minerals in cancer patients, and serum iron level has been shown to be elevated in breast cancer patients. Therefore, the aim of this study was to evaluate hair iron and hair minerals’ level related to hair iron in breast cancer patients compared to controls. We compared hair mineral analysis data of 40 breast cancer subjects with age and body mass index-matched normal control data (n?=?144) by cross-sectional analysis. All breast cancer patients were newly diagnosed at one Breast Cancer Center in Ajou University and had their hair cut before anti-cancer chemotherapy, and the normal controls (without breast cancer) also had their hair cut for various reasons in out-patient clinics of the Department of Family Practice and Community Health. Breast cancer patients had low calcium, magnesium, iron, copper, manganese, and zinc, whereas they had high arsenic, sodium, and potassium compared with the normal control. The hair iron level was positively correlated with hair calcium (r?=?0.761, P?<?0.001), magnesium (r?=?0.643, P?<?0.001), and manganese (r?=?0.550, P?<?0.001) and negatively correlated with arsenic (r?=??0.537, P?<?0.001). The hair iron level was significantly associated with the hair calcium (β?=?0.778, P?<?0.001) and manganese (β?=?0.240, P?<?0.001) by using multiple linear regression analysis. We observed different hair mineral patterns in breast cancer patients compared to normal controls. Especially, hair iron level was significantly reduced and associated with hair calcium and manganese levels.