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[Dynamics of essential trace elements in the body--the mechanism of absorption, transport, storage and excretion].

Essential trace elements have various functional roles in the body. In the present study, we focus on the mechanism of absorption, transport, storage and excretion of trace elements. Essential trace elements are mainly absorbed from the gastrointestinal lumen by passive diffusion or by specialized transport systems and transported to various organs via blood plasma. Essential trace elements are differently distributed in the body. The difference is due to the absorption-excretion systems and a functional role in each organ. The most important excretory pathways for essential trace elements are gastrointestinal and renal ones. We discuss more about the dynamics of essential trace elements in the body.

Animals↗

Introduction of the factor of partitioning in the lithogenic enrichment factors of trace element bioaccumulation in plant tissues.

Bioindicators are widely used in the study of trace elements inputs into the environment and great efforts have been conducted to separate atmospheric from soil borne inputs on biomass accumulation. Many monitoring studies of trace element pollution take into account the dust particles located in the plant surface plus the contents of the plant tissues. However, it is usually only the trace element content in the plant tissues that is relevant on plant health. Enrichment factor equations take into account the trace element enrichment of biomasses with respect soil or bedrocks by comparing the ratios of the trace element in question to a lithogenic element, usually Al. However, the enrichment equations currently in use are inadequate because they do not take into account the fact that Al (or whichever reference element) and the element in question may have different solubility-absorption-retention levels depending on the rock and soil types involved. This constrain will become critical when results from different sites are compared and so in this article we propose that the solubility factors of each element are taken into account in order to overcome this constrain. We analysed Sb, Co, Ni, Cr, Pb, Cd, Mn, V, Zn, Cu, As, Hg, and Al concentration in different zones of Catalonia (NE Spain) using the evergreen oak Quercus ilex and the moss Hypnum cupressiforme as target species. We compared the results obtained in rural and non industrial areas with those from the Barcelona Metropolitan Area. We observed differences in Al concentrations of soils and bedrocks at each different site, together with the differences in solubility between Al and the element in question, and a weak correlation between total soil content and water extract content through different sites for most trace elements. All these findings show the unsuitability of the current enrichment factors for calculating lithospheric and atmospheric contributions to trace element concentrations in biomass tissues. The trace element enrichment factors were calculated by subtracting the part predicted by substrate composition (deduced from water extracts from soils and bedrock) from total concentrations. Results showed that for most of the trace elements analysed, trace elements enrichment factors were higher inside the Barcelona Metropolitan Area than outside, a finding that indicates that greater atmospheric inputs occur in urban areas. The results show that the most useful and correct way of establishing a reference for lithospheric and atmospheric inputs into the plant tissues is, first, to analyse samples of the same plant species collected from a number of sites possessing similar environmental conditions (climate, vegetation type, soil type) and, second, to use this new enrichment factor obtained by subtracting from the total concentration in plant tissue the predicted contribution of soil or bedrock extracts instead of that of total soil or bedrock concentrations.

Biomass↗

[The effects of fluoride-containing trace element agents on the growth of mutants of S. mutans].

OBJECTIVE: To compare the influence of 6 trace element agents containing fluoride versus 6 trace element agents not containing fluoride on the growth of mutants of S. mutans and detect the interaction between fluoride and trace elements. METHODS: Six trace element agents containing fluoride [SnF2, ZnF2, SrF2, LaF2, (NH3)2MoF8, NaF] and 6 trace element agents not containing fluoride [SnCl2, SrCl2, LaCl2, ZnAc2, (NH3)2MoO4, NaCl] were selected. The continuous anaerobic cultivating technique and the absorbency of bacteria liquid and the count of bacteria were used to assess the effects of different agents on the growth of S. mutans. RESULTS: NaF, SnF2, SnCl2, ZnF2, ZnAc2, (NH3)2MoF8 and (NH3)2MoO4 were found to have strong inhibition effects on the growth of mutant of S. mutans(P < 0.01). SnF2 had more stronger inhibition effects than SnCl2; ZnF2 had more stronger inhibition effects than ZnAc2, no significant differences were seen between (NH3)2MoF8 and (NH3)2MoO4. SnF2 and ZnF2 had most potent inhibition effects(P < 0.01). No significant differences were observed between SrF2, SrCl2, LaCl2, LaF2, NaCl and the control groups(P > 0.05). CONCLUSION: The agents containing fluoride and trace elements, such as stannum and zinc had the effects of prohibiting the growth of mutant of S. mutans, As far as caries prevention is concerned, the agents containing both fluoride and trace elements are more effective than mono-fluoride, the potential mechanism may be the synergistic action between fluoride and trace elements.

Cariostatic Agents↗

[Trace elements in artificial nutrition. Art and practice].

The trace elements known to be necessary for man are iron, zinc, copper, selenium, chromium, manganese, molybdenum, cobalt and iodine. This review article, which excludes iron, deals with the need for supplemental trace elements during artificial feeding, and the way they should be administered. The biological importance of these trace elements is argued on the basis of their biochemical involvement and the clinical pictures seen in accidental or experimental deficiency states. Assessing a patient's trace element status is rather difficult. The relative merits of different laboratory investigations is discussed: plasma, erythrocyte, capillary and urinary levels, specific enzyme activities, loading tests. The different situations when trace elements are required, assessing the amount needed and the possible toxic risks, are presented from a literature survey.

Alcoholism↗

[Experimental in vitro model of an artificial kidney--measurement of trace element levels using the ICP method. Preliminary studies].

Trace elements in blood serum is significantly changed in hemodialysed patients. The result of our experiment showed the manner and directions of the evaluated trace elements -Sr, Zn, Ni, Ba, B, Si, Mn and Cu movements. It was confirmed that reverse osmosis is efficient in the most tracers elimination, except Si, B, and Cu. The trace elements being present in the whole arrangement diffuse easily through the dialysers membrane used in our experiment, except Ni. In the membrane of the new, non-rinsed dialyser we detected Pb, Fe, V, Be, Ti and Al. It could possibly be the source of their contamination into the human organism. ICP-AES method of trace elements analysis reveals the possibilities of precisely, fast and simultaneous evaluation of big number various trace elements.

Hemodialysis Solutions↗

Mass spectrometric trace element analysis of calcium oxalate uroliths.

Mass spectrometric trace element analysis of whewellite and weddellite uroliths revealed 55 elements, from which 20 could be well assessed quantitatively. The total trace element content in weddellite increased by 77.5% with respect to whewellite, the main portion being made up from Na, P, Mg, and Cl. In physiological conditions weddellite is stabilized by trace elements. The importance of trace element analysis of Si, Al, Sr, Rb, S, F, Cl, and Br in uroliths is indicated.

Calcium↗

Investigating the sources of the labile fraction in sediments from silicate-drained rocks using trace elements, and strontium and lead isotopes.

Elemental concentrations of the trace elements Rb, Sr, Th, Pb, Zn, Cu, Ni, Cd and Sb, as well as Sr and Pb isotopic compositions, were determined on the labile fraction (called acid-extracted matter AEM, Négrel et al., Chem. Geol. 166 (2000) 271-85) of soil and sediment along two small rivers located in the centre of France, one flowing from basalt, the other one on granite-gneiss. Oxide-mineral form in AEM (i.e. Fe-Mn oxides), acts as the main carrier phase. Analysis of the relationships between the trace elements, and lead and strontium isotopes allows the origin of the elements (i.e. natural and anthropogenic) and their history, both in the sediment and soil from the small watersheds to be assessed. Lead-isotope compositions in AEM display large fluctuation in the two watersheds and show a large scatter between natural input (basalt and granite), atmospheric input from gasoline, and input from past mining activities. On the basaltic watershed, Pb and other trace elements like Sb deriving from past mining waste are mainly related to atmospheric origin, while on the granitic terrain Pb originates from mineralization. The Sr-isotope compositions of AEM, water and residues are similar in the watershed draining basalt. On the watershed draining granite, AEM and streamwater shows 87Sr/86Sr ratios similar in the upstream part of the watershed and a divergence between the two ratios appears in the downstream part of the watershed implying that oxides have precipitated upstream and are not re-equilibrated during their transport downstream.

France↗

[Unrecognised intake of trace elements in polytraumatized and burnt patients].

Recommended trace element doses during parenteral nutrition have been revised many times and increased, especially in surgical patients. Blood products are known to provide significant amounts of trace elements under certain circumstances. In intensive care patients crystalloids and colloids are also given in large amounts. This study aimed at determining the magnitude of the unrecognized trace element administrations after major burns and/or trauma. Fifteen patients burnt 36 +/- 11% (mean +/- SD) of body surface area, aged 34 +/- 8 years, admitted to the Burns Centre and 11 trauma patients with an Injury Severity Score of 29 +/- 6 points, aged 40 +/- 13 years, admitted to the surgical Intensive Care Unit in a Swiss University Hospital. Prospective study of intakes and urinary excretion from the first post-injury day (D1) to D7. Copper and zinc were analyzed by flame atomic absorption spectrophotometry, and selenium by fluorimetry. The actual trace element administrations were much larger than those prescribed in the 3 groups of patients, and were significantly above the most recent parenteral recommended daily allowance = RDA (2.3 times RDA for copper, 5 times for selenium and zinc in Group 2, which received the largest i.v. supplements). There greatest provision of the 3 elements was by the blood products (packed red cells and frozen plasma) and by the albumin solutions (0.5 mg.L-1 Cu, 90 micrograms.L-1 Se and 2.1 mg.L-1 Zn in the 20% solutions). During the resuscitation phase, crystalloids provided a significant amount of copper (0.14 mg.L-1 NaCl 0.9%, none in dextrose) and zinc (0.3 mg.L-1 of any crystalloid), whereas selenium was not detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Numerical simulation of trace element transport on subsurface environment pollution in coal mine spoil.

An understanding of the dynamic behavior of trace elements leaching from coal mine spoil is important in predicting the groundwater quality. The relationship between trace element concentrations and leaching times, pH values of the media is studied. Column leaching tests conducted in the laboratory showed that there was a close correlation between pH value and trace element concentrations. The longer the leaching time, the higher the trace element concentrations. Different trace elements are differently affected by pH values of leaching media. A numerical model for water flow and trace element transport has been developed based on analyzing the characteristics of migration and transformation of trace elements leached from coal mine spoil. Solutions to the coupled model are accomplished by Eulerian-Lagrangian localized adjoint method. Numerical simulation shows that rainfall intensity determined maximum leaching depth. As rainfall intensity is 3.6ml/s, the outflow concentrations indicate a breakthrough of trace elements beyond the column base, with peak concentration at 90cm depth. And the subsurface pollution range has a trend of increase with time. The model simulations are compared to experimental results of trace element concentrations, with reasonable agreement between them. The analysis and modeling of trace elements suggested that the infiltration of rainwater through the mine spoil might lead to potential groundwater pollution. It provides theoretical evidence for quantitative assessment soil-water quality of trace element transport on environment pollution.

Coal Mining↗

Colitis-induced changes in the level of trace elements in rat colon and other tissues.

Trace elements constitute important prosthetic groups in a number of antioxidant enzymes which neutralize free radicals generated during inflammatory conditions such as colitis. However, the status of trace elements in colitis remains to be found. In the present study the concentrations of zinc, copper, manganese and selenium in the colon, liver and serum of rats with acetic acid (HAc)- or trinitrobenzenesulfonic acid (TNBS)-induced colitis were measured using atomic absorption spectrophotometer. Myeloperoxidase and glutathione peroxidase activities were measured spectrophotometrically. Our results show that the selenium concentration was significantly decreased by 33 and 37.5% in the colon and 69 and 78% in liver by HAc and TNBS treatment, respectively. Similarly the zinc concentration in the colon was decreased by 21 and 28% by HAc- and TNBS-induced colitis as compared to the controls, but manganese and copper, remained unaltered. The serum concentrations of copper, zinc and selenium also remained unaltered during colitis. The weight of HAc-treated rats did not decrease while there was a significant weight loss in the TNBS-treated rats. Myeloperoxidase activity was increased, whereas glutathione peroxidase activity was significantly decreased in the colon inflamed by HAc or TNBS as compared to the controls. These findings suggest that colitis induces a reduction in the tissue levels of trace elements which is independent of the way colitis is induced. Our findings of a reduction in Se and glutathione peroxidase activity together suggest that the reduction in the trace element concentrations is not due to dietary factors or malabsorption. The decrease may severely affect the antioxidant potential of the colon and therefore is a putative factor for the progression of disease.

Acetic Acid↗

Complete analysis of the trace elements of the kidney.

The distribution of trace elements in kidney cortex and medulla and in their subcellular fractions was studied by inductively coupled plasma mass spectrometry (ICP-MS). This technology allows the analysis of almost all the elements of the periodic table, along with their isotopes, in the same experiment. Acid digestion of the tissue (samples) was required before ICP-MS elemental analysis. Mineralization in 8 N nitric acid for 2 min in a Parr microwave acid digestion bomb, inside a regular microwave oven working at medium power, gave good sensitivity and reproducible results. Trace element determinations could be precisely performed, despite the presence of a considerable amount of organic matter. Cortex/plasma and medulla/plasma inorganic ratios were taken as indicators of the inorganic bioaccumulation. The highest enrichment factors of elements found in the cortex were Mn greater than Co greater than Tl greater than Zn greater than Rb greater than Mo greater than Cu and the highest element enrichments of the medulla were Tl greater than Mn greater than Co greater than Rb greater than Zn greater than Bi greater than Mo greater than Ni greater than Cu. Subcellular fragmentation of the kidney cortex and medulla indicated that the majority of the trace elements was located in the cytosolic fraction. The membrane fraction of the medulla contained significant amounts of Hg and Al: 120.7 and 32.0 mg/g protein, respectively. Cu and Zn were the most abundant trace elements found in the brush border membrane from the cortex: 120.7 and 68.2 mg/g protein, respectively. These quantities are largely in excess of what is bound, for example, to alkaline phosphatase.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Moisture content in Dall's porpoise (Phocoenoides dalli) tissues: a reference base for conversion factors between dry and wet weight trace element concentrations in cetaceans.

Concentration of trace elements measured by dry weight basis has become more commonly used in recent studies on cetaceans than wet weight basis, which was used more in earlier studies. Because few authors present moisture content data in their papers, it is difficult to compare the concentrations of trace elements between various studies. Therefore, we felt that it would be useful if a reference conversion factor (CF) for tissue types could be found to convert between wet weight and dry weight data on trace element concentrations. We determined the moisture contents of 14 tissues of Dall's porpoise (Phocoenoides dalli), and then, calculated the CF values for those tissues. Because the moisture content of each tissue differs from other tissues, it is necessary to use a specific CF for each tissue rather than a general CF for several tissues. We have also found that CF values for Dall's porpoise tissues are similar to the same tissues in other cetaceans. Therefore CF values from Dall's porpoise can be reliably used to convert between wet and dry weight concentrations for other cetacean tissues as reference data.

Animals↗

A sampling and analytical methodology for dental trace element analysis.

The role of trace elements in human health and environmental pollution has developed into an extensive field of research. This study describes a sampling and analytical strategy to determine the trace element content of primary (deciduous) teeth and to assess their use in environmental health and nutrition studies. Exfoliated and extracted primary teeth were collected from 21 Ugandan and 27 UK children. The crown and root of the teeth were separated and the former digested and analysed for several elements by inductively coupled plasma mass spectrometry. The influence of country, tooth type, age and gender were statistically investigated in addition to within-person variation. A principal components analysis (PCA) was used to treat the data in a multivariate fashion and facilitated the moderation of outliers. The results demonstrated that country of origin has an important influence on the elemental composition of teeth and that tooth type should be controlled in these types of studies. Given such a restriction, the age and gender of the donor should have no effect and do not need to be controlled. In addition, where country of domicile, age and gender were controlled, the concentrations of most elements within a single tooth type were representative of an individual and therefore may be indicative of health status.

Child↗

Trace element chemistry in residual-treated soil: key concepts and metal bioavailability.

Trace element solubility and availability in land-applied residuals is governed by fundamental chemical reactions between metal constituents, soil, and residual components. Iron, aluminum, and manganese oxides; organic matter; and phosphates, carbonates, and sulfides are important sinks for trace elements in soil-residual systems. The pH of the soil-residual system is often the most important chemical property governing trace element sorption, precipitation, solubility, and availability. Trace element phytoavailability in residual-treated soils is often estimated using soil extraction methods. However, spectroscopic studies show that sequential extraction methods may not be accurate in perturbed soil-residual systems. Plant bioassay is the best method to measure the effect of residuals on phytoavailability. Key concepts used to describe phytoavailability are (i) the salt effect, (ii) the plateau effect, and (iii) the soil-plant barrier. Metal availability in soil from metal-salt addition is greater than availability in soil from addition of metal-containing residuals. Plant metal content displays plateaus at high residual loadings corresponding to the residual's metal concentration and sorption capacity. The soil-plant barrier limits transmission of many trace elements through the food chain, although Cd (an important human health concern) can bypass the soil-plant barrier. Results from many studies that support these key concepts provide a basis of our understanding of the relationship between trace element chemistry and phytoavailability in residual-treated soils. Research is needed to (i) determine mechanisms for trace element retention of soil-residual systems, (ii) determine the effect of residuals on ecological receptors and the ability of residuals to reduce ecotoxicity in metal-contaminated soil, and (iii) predict the long-term bioavailability of trace elements in soil-residual systems.

Biological Availability↗

Absorption, transport and tissue storage of essential trace elements.

Intestinal absorption of many essential trace elements probably occurs by saturable and carrier-mediated processes. The nature and efficiency of these are influenced by a range of physiological, nutritional and genetic variables. Special emphasis is given to the influence of exogenous and endogenous ligands of small molecular mass in the intestinal lumen on absorptive efficiency. The effect of enterocyte proteins such as metallothionein which, by sequestering metals, influence their fate during absorption is also considered. Changes in the metabolic activity of the intestinal mucosa induced by copper or zinc deficiencies influence the fate of other nutrients, either by inhibiting intracellular transport or by preventing the degradation of potential antagonists of absorption. Conflicting evidence of roles for plasma albumin, transferrin and caeruloplasmin in the transport of zinc and copper is considered. The extent, location and form in which trace elements are stored in tissues differs between elements and between species. Retention and utilization are also influenced by pregnancy, lactation, stage of foetal development and by genetic variables. Better definition of the effects of these variables would improve the validity of estimates of the trace element requirements of man and other animals.

Animals↗

Phagocytic response of terrestrial and aquatic invertebrates following in vitro exposure to trace elements.

The potential of the trace elements Ag, As, Cd, Hg, Mo, Ni, Pb, Se, and Zn to inhibit the phagocytosis response of extruded coelomocytes of different worm species was tested. We used flow cytometry to evaluate the sensitivity of cell viability and phagocytic potential for Eisenia fetida, Lumbricus terrestris, Aporrectodea turgida, and Tubifex tubifex. Extruded cells were exposed 18 h in vitro to concentrations ranging from 10(-9) to 10(-4) M. Mercury was the most potent immunotoxic element, with 50% inhibition of phagocytosis occurring at concentrations between 10(-7) and 10(-6) M. Cadmium, Cu, Ni, and Zn also showed significant immunosuppressive effects with concentrations inducing 50% inhibition ranging from 10(-5) to 10(-4) M. Species-specific sensitivity varied by about a factor of 10, with no species showing a systematically higher or lower in vitro sensitivity across the range of trace elements tested.

Animals↗

Perinatal changes in the absorption of trace elements.

Fetal demands for many of the essential trace elements change markedly during the terminal stages of development. Susceptibility to deficiency during early postnatal life is influenced by the extent of fetal trace element reserves, by inadequacies in the supply of some elements in maternal milk and by postnatal changes in the efficiency of trace element absorption. The efficiency with which essential and some toxic trace elements are absorbed after birth is a function both of age and of diet. Homeostatic mechanisms for the control of iron absorption are poorly developed in the newborn. There are indications that pinocytotic absorption of iron, copper, lead and cadmium may occur at this stage and account for the high efficiency with which these elements are absorbed from a liquid diet. Evidence of developmental changes in the enterohepatic recirculation of such metals is considered and an account is given of our very inadequate understanding of the processes of trace metal absorption in the weaned animal.

Aging↗

[Study of lacrimal fluid trace elements in several eye diseases].

Trace element composition and content were studied by neutron activation method and atomic emission spectral analysis in 200 lacrimal fluid samples from children and adolescents with emmetropia and progressive myopia of 3.5 to 12.0 diopters and in 48 samples from adults with open-angle glaucoma, diabetic retinopathy, and without ocular diseases (controls). Lacrimal fluid trace element level reflecting their metabolism in the eye was found related to subjects' age and sex and changed in various diseases. Progressive myopia was found associated with reduced cooper content and changed ratio of zinc to iron, this indicating certain metabolic disorders in the connective tissue system, in the scleral membrane first of all, and in the antioxidant defense system. Changed levels of iron, magnesium, and aluminum were detected, and, to a lesser extent, of zinc and copper in patients with diabetic retinopathy, whereas open-angle glaucoma was associated with reduced zinc level and increased iron content.

Adolescent↗