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PubMed1998

Trace element deficiency and toxicity.

Trace elements are involved in enzymatic activities, immunological reactions, physiological mechanisms and carcinogenesis. Deficiency in some trace elements, such as iron and iodine, is still an important health problem, especially in developing countries. Some groups of individuals are more likely to develop trace element deficiency. The role of trace elements deficiency is suspected in various clinical situations and is now confirmed by well designed supplementation studies. Although toxicity of trace elements with clinical manifestations is rare, it has been observed that manganese toxicity may occur in patients receiving parenteral nutrition. Recent data about trace elements deficiency and toxicity are indicated in this review.

Adolescent↗
PubMed1989

Assessment of trace element status in humans.

Trace elements occur in the body in very small or 'trace' amounts. Deficiencies of essential trace elements produce multiple and diverse clinical signs and symptoms. These may arise from inadequate dietary intake, decreased bioavailability, iatrogenic factors, certain disease states in which decreased absorption, excessive excretion and/or utilization occurs, and physiological states in which trace element requirements are increased and/or body stores are reduced. This review discusses both the static and functional laboratory tests used for the assessment of chromium, copper, selenium, and zinc status in humans, with emphasis on those tests suitable for community use. Static tests measure the total quantity of the trace elements in various accessible tissues and body fluids such as hair, nails, blood or some of its components, and urine; functional tests measure the activity of trace-element-dependent enzymes, or a physiological or behavioural function dependent on a specific trace element. The advantages and limitations of each test are discussed, together with the effects of non-nutritional factors that may confound the interpretation of the results. Interpretive criteria are also given, where possible.

Bibliographies as Topic↗
PubMed1978

[Behavior of the trace elements copper, zinc and manganese in bovine rumen. 1. Trace element content of different fractions of rumen fluid and the effect of copper sulfate administration].

Two adult, rumen-fistulated steers were fed, over four consecutive 3-week periods, Cu-deficient and normal hays with and without copper sulphate supplementation. Their rumen liquor levels of copper, zinc and manganese were determined correspondingly. The rumen liquor samples were split into 3 fractions by way of centrifugation, sodium dodecyl sulphate treatment of the sediment and filtration. The fractionation of the rumen liquor showed copper to be contained mainly in the water-soluble supernatant (68%), whilst zinc and manganese are more strongly linked to the microbial fraction (57 and 46%, resp.). The plant residue did not average but 9, 24 and 22% of copper, zinc and manganese, respectively. Copper sulphate supplementation to normal hay resulted in a significantly increased copper content in the supernatant and in the microbial fraction. At the same time, the zinc and manganese content values in the microbial fraction were found increased. However, the same copper sulphate supplementation to Cu-deficient hay was found to reduce highly significantly the copper level in the microbial fraction. It is supposed that the excessively high molybdenum content of this hay (2.5 ng/kg) has prevented any effect of the copper sulphate supplementation. The positive effects of copper sulphate supplementation on the zinc and manganese levels in the bacterial fraction were maintained even when feeding Cu-deficient hay rich in Mo.

Animal Feed↗
PubMed2000

Comparison of representative ranges based on U.S. patient population and literature reference intervals for urinary trace elements.

Reference intervals for trace elements are very hard to obtain because of the difficulty of defining a nonexposed reference population. However, representative ranges for trace elements obtained from a general patient population can provide useful information in interpreting laboratory results. We have used urine specimens submitted for trace metal analysis from patients residing in the United States to calculate representative ranges for 25 urinary trace elements, and to compare them to reference values taken from the literature. All urine analytes were measured by inductively-coupled plasma-mass spectrometry except chromium, which was measured by graphite furnace atomic absorption spectroscopy. For representative range calculation two approaches were used. In the non-parametric calculation first, the top 10% of results were discarded assuming that those specimens came from individuals with unusually high trace element exposures. Next the central 95% of the remaining data was taken as the reference interval. In the parametric calculation the specimens from exposed or not healthy individuals were assumed to appear as outliers and were discarded. The mean and S.D. were calculated, and used to determine representative ranges. The two approaches yielded very similar results, and worked remarkably well for 14 analytes. There were minor discrepancies for 7 analytes, and major for 4 analytes. All analyses of urinary trace elements included a urine creatinine value, which was used to express urinary trace element concentrations in terms of creatinine ratio. This corrects for differences in urine concentration that affects the results for random specimens.

Aging↗
PubMed1985

Therapeutic uses of trace elements.

The properties of trace elements which feature in their therapeutic activity are: binding to macromolecules (enzymes, nucleic acids, etc.) with disturbance of biological function, and interaction with other elements. These properties, particularly the binding to large molecules, are far from specific, an observation which is reflected in the very wide range of diseases in which trace elements are employed. While metal compounds have been administered for several centuries, the scientific basis for treatment with trace elements began with the use of gold compounds, initially in patients with tuberculosis and later those with rheumatoid arthritis. Although many other drugs have been developed, some of which also include metal complexes, gold has retained an important position in the treatment of this condition. The gold-induced effects upon the immunological aspects of RA are also observed in other conditions with autoimmune involvement. The antineoplastic potential of metal complexes will be further exploited by the development of less toxic compounds--of platinum and possibly also of other metals. At the same time there are improvements in the protocols for administration which increase the range of cancers responding to treatment. Perturbation of gastrointestinal activity represents another area where trace elements have an important therapeutic role, both in the control of intraluminal acidity and in the adjustment of nutrient availability. A fourth significant area of trace element therapeutics involves the central nervous system where the use of lithium has provided spectacular results in the treatment of affective and other disorders. With a very wide range of other conditions in which they are employed, therapeutic uses provide somewhat unusual illustrations of the importance of trace elements in human disease.

Arthritis, Rheumatoid↗
PubMed2001

Human placenta as a 'dual' biomarker for monitoring fetal and maternal environment with special reference to potentially toxic trace elements. Part 2: essential minor, trace and other (non-essential) elements in human placenta.

A survey of elemental composition of the human placenta was undertaken to evaluate reference values for minor and trace elements (essential and non-essential). The new data collection was narrowed down to results generated between the period of 1975-2000, since analytical methodology was becoming increasingly reliable with time for many elements. The search revealed the following results (microg/g, based on wet weight): Ca = 770; Cl = 1900; K = 1685; Mg = 100; Na = 360; P = 1700; and S = 350. However, Na, P and S need further confirmation. For a group of essential trace elements following average values were evaluated (microg/g, based on wet weight): Co = 0.007; Cr = 0.03; Cu = 0.9; Fe = 69; I = 0.005; Mn = 0.08; Mo = 0.02; Se = 0.2; and Zn = 10. However, the iodine value needs further confirmation. In addition, information values have been identified for a number of so-called non-essential elements such as Ag, Au, B, Ba, Br, Cs, F, La, Rb, Sb, Sc, Si, Sn, Sr, Ti, V and W. The survey results for toxic trace elements As, Cd, Hg, Ni and Pb are discussed in part 3 of this paper along with placenta as a biomonitor for toxic trace elements.

Adult↗
PubMed1988

Carcinogenesis as the result of the deficiency of some essential trace elements.

"Energetic" biological trace elements [gallium (III), germanium (IV), silicon (silica), arsenic (V) and selenium (IV)] occurring in DNA of eukaryotic cells may improve the semiconductor properties of DNA and may influence the mechanisms that control genetic expression at the electronic level. Their roles are postulated as follows: (i) to maintain the level and direction of free sliding electrons in DNA, (ii) to modulate the electron conductivity and hole conductivity of DNA. This specific electronic nature of DNA take the form of magnetic pigeonholes in which an electric pulse is (0), or is not (1) stored as an area of local magnetisation. These types of conductivity occurring in different parts of DNA of different cells could participate in the switch on and switch off of genetic information in gene expression. This model may help to elucidate the mechanism of action of these naturally occurring antitumor agents and may help in understanding the role of trace elements in charge transport of DNA and in carcinogenesis.

Animals↗
PubMed1974

Aspergillus flavus infection and aflatoxin production in corn: influence of trace elements.

Distribution of trace element levels in corn germ fractions from kernels naturally infected with Aspergillus flavus and from kernels free of the fungus demonstrated an association between the presence of A. flavus and higher levels of metals. A. flavus production of aflatoxin on various autoclaved corn media showed that ground, whole corn was an excellent substrate; similar high levels of toxin were observed on full-fat corn germ but endosperm and defatted corn germ supported reduced yields. The influence of trace elements and their availability in defatted corn germ to A. flavus-mediated aflatoxin biosynthesis were measured. Enrichment of the substrate with 5 to 10 mug of manganese, copper, cadmium, or chromium per g of germ increased toxin yields. Addition of lead or zinc (50 to 250 mug/g) also enhanced toxin accumulation. Aflatoxin elaboration was reduced by the addition of 25 mug of cadmium per g or 500 mug of copper per g of germ.

Aflatoxins↗
PubMed1980

Trace elements in nutrition.

Advances in trace element research over the last decade have done much to elucidate the function of these nutrients at the biochemical level. Five new trace elements have been identified and the general relevance of microelements in human nutrition has undergone reassessment. Deficiencies of iodine, iron and fluorine remain important problems and necessitate supplementation. Suboptimal nutrition in chromium, copper, selenium, zinc and possibly vanadium has been suggested, and these elements are generally acknowledged to be of concern in human nutrition. Genetic factors and other "conditioning" agents have been implicated in the aetiology of a number of trace element deficiencies in apparently well nourished communities. Tissues under anabolic stress have been recognized to be especially sensitive to trace element deficits, and the particular vulnerability of the fetus has been demonstrated on a number of occasions. In practical dietary terms, the loss of microelements during the refining and processing of food has been widely illustrated. Also, the generally lower levels of trace elements in plant material and the lower availability of minerals from these food sources has been well established. Of the newer trace element deficiencies, zinc impoverishment appears to be especially important, as a state of physiological zinc deficiency rapidly follows dietary insufficiency, and the consequences on all growing tissues are particularly serious. In general, recent developments suggest that marginal deficiencies of microelements are more widespread in human nutrition than was previously appreciated. Greater attention to trace element status seems to be indicated in circumstances in which physical condition and vigour are unaccountably poor and especially in situations accompanied by active anabolism.

Animals↗
PubMed1984

Analytical methods for trace elements in biological material.

Trace elements and essential trace elements are defined. The principal methods commonly used for their analysis in biological tissues are reviewed. The methods covered are chemical, electrochemical, optical spectrometry, X-ray spectrometry, mass spectrometry, and nuclear methods. The great importance of the sampling procedure and sample treatment is pointed out. The most sensitive, most generally applicable multi-element procedure is neutron activation analysis. The main drawbacks are that the procedure is time-consuming and expensive. Atomic absorption spectrometry is the most popular method. It is fast and inexpensive but can usually only be used as a single-element technique.

Activation Analysis↗
PubMed2006

Impact of river overflowing on trace element contamination of volcanic soils in south Italy: part II. Soil biological and biochemical properties in relation to trace element speciation.

The effect of heavy metal contamination on biological and biochemical properties of Italian volcanic soils was evaluated in a multidisciplinary study, involving pedoenvironmental, micromorphological, physical, chemical, biological and biochemical analyses. Soils affected by recurring river overflowing, with Cr(III)-contaminated water and sediments, and a non-flooded control soil were analysed for microbial biomass, total and active fungal mycelium, enzyme activities (i.e., FDA hydrolase, dehydrogenase, beta-glucosidase, urease, arylsulphatase, acid phosphatase) and bacterial diversity (DGGE characterisation). Biological and biochemical data were related with both total and selected fractions of Cr and Cu (the latter deriving from agricultural chemical products) as well as with total and extractable organic C. The growth and activity of soil microbial community were influenced by soil organic C content rather than Cu or Cr contents. In fact, positive correlations between all studied parameters and organic C content were found. On the contrary, negative correlations were observed only between total fungal mycelium, dehydrogenase, arylsulphatase and acid phosphatase activities and only one Cr fraction (the soluble, exchangeable and carbonate bound). However, total Cr content negatively affected the eubacterial diversity but it did not determine changes in soil activity, probably because of the redundancy of functions within species of soil microbial community. On the other hand, expressing biological and biochemical parameters per unit of total organic C, Cu pollution negatively influenced microbial biomass, fungal mycelium and several enzyme activities, confirming soil organic matter is able to mask the negative effects of Cu on microbial community.

Bacteria↗
PubMed1995

Trace elements in chronic sinusitis.

Trace elements are indispensable for life and play an important role in the immunological system. Since it is believed that serum trace element values decrease in chronic infections, 43 patients with chronic sinusitis were evaluated for Zn, Mg and Cu levels. While all trace elements were found to be within normal ranges, Cu values were found to be significantly lower than in a control group of 20 age- and sex-matched volunteers. The reasons for this are unclear in the present study.

Case-Control Studies↗
PubMed1992

[Effects of an essential trace element agent (TE-5) for total parenteral nutrition on the mineral nutrition in rats fed a trace element-deficient diet].

TE-5 is an essential trace element agent containing iron, zinc, copper, manganese and iodine for total parenteral nutrition (TPN). We have already reported that TE-5 improved the reduction of trace element concentrations induced by TPN. However, effects of TE-5 on the changes in biological function relating to trace elements are poorly understood. The present study was designed to clarify the effects of TE-5 on these functions. Rats fed a trace element (iron, zinc, copper, manganese and iodine)-deficient diet for 7 weeks showed reductions in the following parameters: plasma and various tissue concentrations of iron, zinc, copper, manganese and iodine, growth rate, erythrocyte (iron), hemoglobin (iron), hematocrit (iron), mean corpuscular constants (iron), plasma alkaline phosphatase activity (zinc), serum ceruloplasmin concentration (copper), liver pyruvate carboxylase activity (manganese) and serum thyroxine concentration (iodine). On the other hand, when TE-5 (0.008, 0.04 and 0.2ml/kg: x 0.2, x 1 and x 5 the usual clinical dose, respectively) was intravenously administered once a day for 7 weeks under the conditions described above, there was a tendency to prevent the reductions of plasma and various tissue concentrations of iron, zinc and manganese. In addition, TE-5 prevented the reductions of growth rate, iron metabolism functions, plasma alkaline phosphatase activity, serum ceruloplasmin concentration and liver pyruvate carboxylase activity. The present study shows that TE-5 prevents both reductions of trace element contents and trace element-related functions, and suggests that TE-5 is useful for treatment of trace element deficiency in TPN.

Animal Nutritional Physiological Phenomena↗