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PubMed2003

Trace elements in human physiology and pathology. Copper.

Copper is a trace element, important for the function of many cellular enzymes. Copper ions can adopt distinct redox states oxidized Cu(II) or reduced (I), allowing the metal to play a pivotal role in cell physiology as a catalytic cofactor in the redox chemistry of enzymes, mitochondrial respiration, iron absorption, free radical scavenging and elastin cross-linking. If present in excess, free copper ions can cause damage to cellular components and a delicate balance between the uptake and efflux of copper ions determines the amount of cellular copper. In biological systems, copper homeostasis has been characterized at the molecular level. It is coordinated by several proteins such as glutathione, metallothionein, Cu-transporting P-type ATPases, Menkes and Wilson proteins and by cytoplasmic transport proteins called copper chaperones to ensure that it is delivered to specific subcellular compartments and thereby to copper-requiring proteins.

Adenosine Triphosphatases↗
PubMed2005

Effects of iron manipulation on trace elements level in a model of colitis in rats.

AIM: Trace elements (TE) metabolism is altered in inflammatory bowel diseases. TE (zinc and copper) are constituents of antioxidant enzymes. Iron is involved in the pathogenesis of chronic inflammation. The aim was to evaluate zinc and copper status and the effects of iron manipulation in experimental colitis. METHODS: Twenty-four male Sprague-Dawley rats were divided into four groups: standard diet, iron-deprived diet, iron-supplemented diet, and sham-treated controls. Macroscopic damage was scored. DNA adducts were measured in the colon. Liver and colonic concentration of TE were measured. RESULTS: Macroscopic damage was reduced in iron-deprived groups and increased in iron-supplemented rats. Damage to the DNA was reduced in iron-deprived groups and increased in iron-supplemented groups. Liver and colonic iron concentrations were reduced in iron-deprived and increased in iron-supplemented rats. Liver zinc concentration was reduced after supplementation whereas colonic levels were similar in controls and treated rats. Liver copper concentration was reduced in all the colitic groups except in the iron-supplemented group whereas colonic concentration was increased in iron-deprived rats. CONCLUSION: Iron deprivation diminishes the severity of DNBS colitis while supplementation worsens colitis. Zinc and copper status are modified by iron manipulation.

Animals↗
PubMed1997

Bioavailability of oral vitamins, minerals, and trace elements in perspective.

Bioavailability of orally administered vitamins, minerals, and trace elements is subject to a complex set of influences. Still, administrative regulation is necessary on how to quantify it. The most common approach to this problem is to determine the fraction of an oral dose that reaches the systemic circulation. For micronutrients, however, this approach has to consider the physiological plasma concentration as well as the mechanisms that regulate intestinal absorption and distribution of micronutrients between functional and storage compartments in response to the demand. The rate of exchange between these compartments has an impact on the delivery of such compounds into the plasma compartment as well as on the plasma clearance. Monitoring the area under the plasma concentration time curve after oral administration is an inadequate tool for bioavailability determination if there are substantial impacts of homeostatic mechanisms on the plasma concentration of a micronutrient. In nutritional science the term "bioavailability" encompasses the sum of impacts that may reduce or foster the metabolic utilisation of a nutrient. Bioavailability in this sense can be quantified by the rate by which deficiency symptoms are cured or by the weight gain during growth. both of these endpoints, again, are influenced by homeostatic mechanisms. To exemplify the scope of impacts on parameters that are commonly used to quantify the bioavailability of oral micronutrient preparations the basic traits of homeostatic regulation are summarised and compared for iron, magnesium, vitamin A, folic acid, and vitamin B12. The mechanisms that adapt absorption, distribution, and excretion of these five micronutrients to the demand differ to such an extent that no common approach can be derived to consider these impacts in bioavailability determination. In consequence, therefore, we recommend to define and regulate individual strategies for bioavailability testing for each micronutrient with regulated kinetics.

Administration, Oral↗
PubMed2001

High-temperature, microwave-assisted UV digestion: a promising sample preparation technique for trace element analysis.

A novel, microwave-assisted, high-temperature UV digestion procedure was developed for the accelerated decomposition of interfering dissolved organic carbon (DOC) prior to trace element analysis of liquid samples such as, industrial/municipal wastewater, groundwater, and surface water, body fluids, infusions, beverages, and sewage. The technique is based on a closed, pressurized, microwave digestion device. UV irradiation is generated by immersed electrodeless Cd discharge lamps (228 nm) operated by the microwave field in the oven cavity. To enhance excitation efficiency an antenna was fixed on top of the microwave lamp. The established immersion system enables maximum reaction temperatures up to 250-280 degrees C, resulting in a tremendous increase of mineralization efficiency. Compared to open UV digestion devices, decomposition time is reduced by a factor of 5 and the maximum initial concentration of DOC can be raised by at least a factor of 50. The system's performance on a real-type sample was evaluated for the mineralization of skimmed milk (IRMM, CRM 151) and subsequent determination of trace elements using standard spectroscopic techniques. Recovery for Cd (109%), Cu (112%), Fe (99%), and Pb (96%) showed good agreement with the 95% confidence interval of the certified values.

Animals↗
PubMedDate not supplied

Certified reference material for analytical quality assurance of minor and trace elements in food and related matrixes based on a typical Japanese diet: interlaboratory study.

A Certified Reference Material (CRM) was prepared at the National Institute for Environmental Studies (NIES), Japan, in collaboration with the National Institute of Radiological Sciences (NIRS), Japan, for the analytical quality assurance of minor and trace elements in food and related matrixes. The starting material for the CRM was all food served in 29 households in Japan over two 3-day periods in 1997-1998, and thus the CRM represented a typical Japanese diet. All foods (meals, snacks, and beverages) were homogenized, freeze-dried, pulverized, blended, dispensed into 1,100 bottles, and sterilized. The within- and between-bottle homogeneity of the prepared CRM was satisfactory for most of the elements. The concentrations of 14 elements (Na, Mg, K, Ca, Mn, Cu, Zn, As, Se, Sr, Cd, Sn, Ba, and U) were certified based on a collaborative analysis involving NIES, NIRS, and 20 other laboratories. Reference values were given for the concentrations of 12 additional elements (P, Cl, Fe, Co, Ni, Br, Rb, Mo, I, Cs, Pb, and Th). The elements certified and those given reference values include minerals, essential trace elements, contaminant elements, and long-lived radionuclides. Thus, this CRM is of practical value in the quality assurance of element analysis of foods and diets in nutritional, environmental, and radiological research.

Diet↗
PubMed2001

Deposition of trace elements in the sediments of ponds around Lakamanahalli industrial area, near Dharwad city, Karnataka, India.

Sediments have been collected from Rayapur and Sattur ponds around Lakamanahalli industrial area and analysed for trace elements content viz., Cd, Pb, Ni, Cu, Zn, Mn, Fe and Cr. Sediments showed 2-fold increased level of studied elements concentration in comparison with relatively non-polluted values. Further, the results of "correlation coefficient and t-test" values indicate positive correlation in deposition and significant at 5% level of confidence. The higher content of these trace elements in the sediments is attributed to surrounding industrial activity.

Environmental Monitoring↗
PubMed2002

Effects of chronic dietary exposure to trace elements on banded water snakes (Nerodia fasciata).

Little currently is known about the accumulation or effects of contaminants on reptiles. To date, most studies examining reptile exposure to trace elements report tissue burdens of field-captured animals, but seldom provide insight into the dose, duration, or mode of exposure involved. For two years, we fed juvenile banded water snakes (Nerodia fasciata) prey items collected from a coal ash-contaminated site that contained elevated levels of As, Cd, Cu, Se, Sr, and V. With the exception of Cu, snakes accumulated significant concentrations of elements, usually in a dose-dependent manner. Accumulation varied significantly among liver, kidney, and gonads, and in most cases between sexes. Selenium accumulation was most notable, greatly exceeding established toxicity thresholds for other vertebrates. Despite the high concentrations of pollutants accumulated, snakes exposed to the contaminated diet survived through the study and exhibited normal food consumption, growth, condition factor, overwinter survival and mass loss, metabolic rate, and gonadosomatic index. The results of this study confirm that diet can be a significant route of exposure to trace elements in snakes and indicate that further studies on snakes are warranted to better understand their responses to contaminants.

Administration, Oral↗
PubMed2006

On-line preconcentration system using mini-column packed with a chelating resin for the characterization of seasonal variations of trace elements in seawater by ICP-MS and ICP-AES.

An on-line column preconcentration technique coupled with inductively coupled plasma-mass spectrometry (ICP-MS) and -atomic emission spectrometry (ICP-AES) was developed using a mini-column (ca. 3 mm i.d., 40 mm length), that was packed with chelating resin (0.2 g) of iminodiacetic acid groups, Muromac A-1. After the preconcentration step, the column was washed with ammonium acetate buffer (pH 5.5) and water to remove major elements, such as Ca and Mg, and then eluted with 4 ml of 2 mol l(-1) nitric acid. Eleven trace elements (Al, V, Fe, Co, Ni, Cu, Zn, Cd, Pb, Th and U) in seawater were determined by ICP-MS/AES. Recoveries for most of the elements tested were over 90%, although those for Al, V and Th were around 70%. The accuracy of the proposed method was evaluated by analyzing a standard reference material of seawater (NASS-4, NRC Canada). The values of Fe, Co, Ni, Cu, Zn, Cd and Pb obtained with the present method showed good agreement with the certified values as judged from the standard deviation. The method was successfully applied to characterize seasonal variations of trace elements in deep seawater (DSW) and surface seawater (SSW). In addition, no serious decrease in analytical performance of the present column system was observed during the experimental period of about 1 year.

Adsorption↗
PubMed2001

Trace elements and their distribution in protein fractions of camel milk in comparison to other commonly consumed milks.

Studies on camels' milk, whether with respect to concentration or bioavailability of trace elements from this milk, are limited and warrant further investigation. The object of this study was to analyse the concentration and distribution of zinc, copper, selenium, manganese and iron in camel milk compared to those in human milk, cows' milk and infant formula under similar experimental conditions. Camels' milk and cows' milk were collected from local farms, human milk samples were obtained from healthy donors in Kuwait and infant formula was purchased locally. Milk fractionation was performed by ultra-centrifugation and gelcolumn chromatography. The concentration of trace elements was analysed by atomic absorption spectrometry and that of protein was determined spectrophotometrically. The concentration of manganese and iron in camels' milk was remarkably higher (7-20-fold and 4-10-fold, respectively) than in human milk, cows' milk and infant formula. The zinc content of camels' milk was higher than that of human milk but slightly lower than in cows' milk and infant formula. The concentration of copper in camels' milk was similar to that of cows' milk but lower than in human milk and infant formula. The selenium content of camels' milk was comparable to those of other types of milk, Approximately 50-80% of zinc, copper and manganese in camels' milk were associated with the casein fraction, similar to that of cows' milk, The majority of selenium and iron in camels' milk was in association with the low molecular weight fraction, It is recommended that camels' milk be considered as a potential source of manganese, selenium and iron, perhaps not only for infants, but also for other groups suspected of mild deficiency of these elements. Further investigations are required to confirm this proposal.

Animals↗
PubMed2003

Genomic scale profiling of nutrient and trace elements in Arabidopsis thaliana.

Understanding the functional connections between genes, proteins, metabolites and mineral ions is one of biology's greatest challenges in the postgenomic era. We describe here the use of mineral nutrient and trace element profiling as a tool to determine the biological significance of connections between a plant's genome and its elemental profile. Using inductively coupled plasma spectroscopy, we quantified 18 elements, including essential macro- and micronutrients and various nonessential elements, in shoots of 6,000 mutagenized M2 Arabidopsis thaliana plants. We isolated 51 mutants with altered elemental profiles. One mutant contains a deletion in FRD3, a gene known to control iron-deficiency responses in A. thaliana. Based on the frequency of elemental profile mutations, we estimate 2-4% of the A. thaliana genome is involved in regulating the plant's nutrient and trace element content. These results demonstrate the utility of elemental profiling as a useful functional genomics tool.

Algorithms↗
PubMed2005

[Quantitatively determining trace elements Co and Bi in gelatin by inductively coupled plasma atomic emission spectrometry method--applying IEC model to correct the spectral interference of Fe to Co].

By ICP-AES, the authors established the method to quantitatively determine the trace elements Co and Bi in gelatin. The authors processed the unknown sample with wet digesting method. Trace elements in gelatin could be quantitatively determined at the same time. To correct the spectral interference of Fe to Co at specific wavelength, the Interelement Correction(IEC) model was established. The results of the experiment showed that the IEC model could effectively erase the spectral interference of Fe to Co. The result of the spectral correction was greatly superior to the result where the spectral interference weren't corrected by the IEC model. The method was accurate, quick with high performance and wide linear range. The linear correlation coefficient of the tested elements was over 0.999 90. The relative standard deviation (RSD%) was less than 2.00%. The recovery rates were in the range of 98%-107%.

Bismuth↗
PubMed2002

Influence of age, sex, and sexual activity on trace element levels and antioxidant enzyme activities in field mice (Apodemus sylyaticus and Mus spretus).

The influence of age, gender and sexual activity on both hepatic levels of some trace elements (Fe, Cu, Zn, Mn, Se) and the activities of glutathione-S-transferase (GST) and superoxide dismutase (SOD) was investigated in Wood mice (Apodemus sylvaticus) and Algerian mice (Mus spretus). Animals were taken from a riverside community of an unpolluted area of central Portugal. Adult A. sylvaticus presented the highest hepatic mean concentrations of Cu and Mn, whereas adult M. spretus had the highest Fe concentration in the liver. Moreover, an influence of age on the contents of Fe, Zn, and Mn has been observed in A. sylvaticus, whereas in M. spretus an influence of gender and sexual activity was only detected on Zn levels. In contrast, enzyme activities were not influenced by the studied variables, despite a tendency for an increase in SOD activity in sexually active M. spretus. GST activity was species dependent, whereas SOD activity was similar between species. These findings were analyzed regarding the relationship of both essential trace elements and the two antioxidant enzymes with physiological and metabolic pathways related to life cycles in the two species of mice. Results enhanced the understanding of A. sylvaticus and M. spretus as biological models, allowing their future use as bioindicators of environmental toxicity.

Aging↗
PubMed1988

[Cellular homeostasis and trace elements].

The authors consider the relevance of essential and toxic elements to the maintenance and derangement of cellular homeostasis, review different routes of their introduction in and release from varying cell types as well as relationships with specific ligands, distribution by intracellular pools. Presented are also morphological data on trace elements accumulation in cell, organs and compartments. A number of trace elements contributed to mutagenesis and carcinogenesis while the others demonstrate anticarcinogenic and antiblastic action.

Animals↗
PubMedDate not supplied

An approach to assessing trace element bioavailability from milk in vitro. Extrinsic labeling and proteolytic degradation.

Both in vitro and in vivo, the use of a radioisotope can significantly enhance the sensitivity of methods for trace element studies. An essential prerequisite for this approach, however, is that the added (extrinsic) radiolabel equilibrates with the native (cold) element within all compartments of the diet. By using ultracentrifugation, ultrafiltration, and gel filtration chromatography, we have shown that the method is valid for zinc, copper, and manganese when using milks and formulas. For iron, however, extrinsic labeling does not necessarily yield results similar to the native distribution. We have used extrinsic labeling to follow the distribution of Zn, Cu, and Mn between high molecular weight compounds (proteins) and low molecular weight complexes in human and bovine milk after in vitro proteolysis. Peptic digestion at various pHs and pancreatic digestion for varying times were used to mimic digestion in the infant. After limited proteolysis, a large proportion of trace minerals in human milk was found in the low molecular weight fraction, whereas in cow's milk a large proportion was bound to incompletely digested casein. These findings may, at least in part, explain the higher bioavailability of trace elements from human milk compared to cow's milk.

Animals↗
PubMed2000

Content of minor and trace elements, and organic nutrients in representative mixed total diet composites from the USA.

As part of an international nutrition project sponsored by the International Atomic Energy Agency (see footnote), Vienna, Austria, a number of bench-mark mixed total diet composites from the United States were collected and analyzed for minor and trace elements. In this segment of the project, the daily dietary intakes of the minor elements Ca, Cl, K, Mg, N and P and the trace elements Al, As, Au, Br, Cd, Co, Cr, Cs, Cu, Fe, Hg, I, Mn, Mo, Ni, Pb, Rb, Sb, Sc, Se, Sn, Sr, V, Zn and W were determined in mixed total diet composites of foods collected in the FDA Total Diet Study (FDA-TDS). These diets are representative of foods consumed by 25-30-year-old males (representing the mixed population groups in the United States), the highest of eight intake groups in the TDS scheme. In order to link the US mixed diet composite results from this study group to the more comprehensive information generated by the FDA-TDS, the results are compared with the same age-sex group published by the FDA-TDS scheme. The FDA-TDS scheme is based on individual analysis of the 201 food items, with resultant calculation of the daily intake representative of various age-sex groups. The comparison shows excellent agreement for 21 elements which have been investigated by both approaches. Additional elements are reported in the US mixed diet composites from the present study which demonstrate a valuable supplement to the data obtained by FDA-TDS scheme. Further the mixed total diet composite approach has also proven useful for the assessment of dietary intake of proximates (protein, fat, carbohydrates), fiber and phytate. In addition, vitamins thiamin, riboflavin, niacin, B6, B12, pantothenic acid, folic acid and biotin were also assayed in these composites.

Adult↗
PubMed1989

Effect of kainate-induced seizures on tissue trace element concentrations in the rat.

It has been shown that epileptics have lower mean blood concentration of manganese than do controls but the cause of this abnormality has not been determined. In order to investigate the effects of seizures on manganese distribution in the body, rats were treated with kainic acid to produce spontaneous seizures which were quantitated for number and severity. Manganese, zinc, copper and iron concentrations were determined in blood, brain, liver, heart and kidney. Kainate-treated animals ate more food but gained less weight than controls. Liver and kidney manganese concentrations were significantly higher in kainate-treated animals than in controls. Blood manganese concentration showed a significant negative correlation with seizure index while heart manganese concentration showed a significant positive correlation with seizure index. None of the other trace elements showed a significant correlation between trace element concentration and seizure index in any of the tissues, although iron concentration was lower in brain and copper concentration was lower in kidney of kainate-treated animals than in their appropriate controls. These data show that manganese concentrations are generally elevated in tissues of kainate-treated animals. This increased manganese concentration may be related to the increased energy demand of these animals.

Animals↗
PubMedDate not supplied

Collection and preparation of sidestream cigarette smoke for trace elemental determinations by graphite furnace atomic absorption spectrometry and inductively coupled plasma mass spectrometry.

A novel method for the collection and preparation of sidestream cigarette smoke condensate is described for trace elemental analysis by inductively coupled plasma mass spectrometry and graphite furnace atomic absorption spectrometry. The smoke collection method utilizes a specially designed chimney that collects and directs the sidestream smoke (SS) to a 2-stage trapping system consisting of an impaction trap followed by a 0.8 microm mixed cellulose ester filter. The samples are digested with nitric acid in a commercial heating block before analysis. The method limits of detection (LODs) are 1, 0.2, 2, 9, 6, and 7 ng/cigt for As, Cd, Pb, Ni, Se, and Cr, respectively. The SS collected from an industry reference cigarette, 1R4F, produced by the University of Kentucky was analyzed. The concentrations of As, Cd, and Pb in 1R4F were determined to be 27.3+/-2.1, 412+/-14, and 43.8+/-2.0 ng/cigt, respectively, while the concentrations of Ni, Cr, and Se are below the method LOD. Consequently, this novel method successfully addresses contamination, instrumentation, and collection issues for performing trace elemental analysis of sidestream cigarette smoke condensate.

Mass Spectrometry↗
PubMed2000

Role of micro-nutrients and trace elements in carcinoma of larynx.

Cancer of the larynx is fourteenth most common cancer in the world. Evidence from case-control studies conducted in developed as well as developing countries suggest that specific micro-nutrients and trace elements have been implicated to be significantly associated with laryngeal carcinoma. The association of these micro-nutrients and trace elements with laryngeal cancer has been discussed in this review article.

Carcinoma↗