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Trace element trophic transfer in aquatic organisms: a critique of the kinetic model approach.

The bioaccumulation of trace elements in aquatic organisms can be described with a kinetic model that includes linear expressions for uptake and elimination from dissolved and dietary sources. Within this model, trace element trophic transfer is described by four parameters: the weight-specific ingestion rate (IR); the assimilation efficiency (AE); the physiological loss rate constant (ke); and the weight-specific growth rate (g). These four parameters define the trace element trophic transfer potential (TTP = IR.AE/[ke + g]) which is equal to the ratio of the steady-state trace element concentration in a consumer due to trophic accumulation to that in its prey. Recent work devoted to the quantification of AE and ke for a variety of trace elements in aquatic invertebrates has provided the data needed for comparative studies of trace element trophic transfer among different species and trophic levels and, in at least one group of aquatic consumers (marine bivalves), sensitivity analyses and field tests of kinetic bioaccumulation models. Analysis of the trophic transfer potentials of trace elements for which data are available in zooplankton, bivalves, and fish, suggests that slight variations in assimilation efficiency or elimination rate constant may determine whether or not some trace elements (Cd, Se, and Zn) are biomagnified. A linear, single-compartment model may not be appropriate for fish which, unlike many aquatic invertebrates, have a large mass of tissue in which the concentrations of most trace elements are subject to feedback regulation.

Animals↗

Trace element studies on four species of Fusarium.

Trace element studies were carried out on four species of Fusarium: F. moniliforme, F. solani, F. poae and F. bulbigenum. Out of fifteen trace elements tested, Fe, Zn, Mn, Cu, Mo and B were found to be essential for growth and sporulation of all these species of Fusarium. Optimum concentrations in ppm of essential trace elements of these fungi were as follows: F. moniliforme Fe 1.0, Zn 0.1, Mn 0.1, Cu 0.1, Mo 0.1, B 1.0-10.0; F. solani Fe 1.0, Zn 10.0, Mn 0.1, Cu 0.01, Mo 1.0, B 0.1; F. poae Fe 1.0, Zn 0.1, Mn 0.1, Cu 1.0, Mo 0.1, B0.1, F. bulbigneum Fe 10.0, Zn 1.0, Mn 1.0, Cu 1.0, Mo 0.01, B 1.0. Concentrations higher than the optimum were inhibitory to the respective fungi.

Dose-Response Relationship, Drug↗

Trace element changes in sclerotic heart valves from patients undergoing aortic valve surgery.

Several trace elements are essential nutrients for an optimal functioning of organs and tissues, including the immune system and the heart. The pathogenesis of some heart diseases has been associated with changes in the balance of certain trace elements. The etiology of nonrheumatic aortic valve sclerosis is unknown, however. A prospective study was performed on trace element changes in the sclerotic valves of 46 patients undergoing surgical aortic valve replacement because of aortic stenosis. Valves from 15 individual forensic cases without known cardiac disease served as controls. The contents of 15 trace elements (Al, As, Cd, Ca, Co, Cu, Fe, Pb, Mg, Mn, Hg, Se, Ag, V, and Zn) were measured by inductively coupled plasma - mass spectrometry (ICP-MS) of aortic valve tissue from both patients and forensic autopsy controls. Some trace elements showed similar concentrations in sclerotic and control valves (Al, Ag, Hg, Mn), whereas a few were moderately changed in the sclerotic as compared with the control valves, including an increase in Cd by 52% (p < 0.05) and decreases in Se by 14% (p < 0.05), in V by 42% (p < 0,001), and in Cu by 45% (p < 0.001). However, there were pronounced increases (p < 0.001) in the concentrations of As (5-fold), Ca (70-fold), Co(10-fold), Fe (20-fold), Pb (8-fold), Mg (20-fold), and Zn (10-fold) in the sclerotic valves. Thus, sclerotic aortic valve disease is associated with a pronounced imbalance in several trace elements of well-known importance for cardiovascular and immune function as well as in trace elements with hitherto unknown significance.

Adolescent↗

Epochal trace elements and evolution.

The use of some trace elements by plants and animals during the evolutionary process has resulted in epochal changes. Noteworthy is the fact that plants (but not animals) needed boron in order to grow stems and roots as they left the seas and became anchored on land. Iodine is plentiful in sea water but rare on land. Therefore, the iodination of tyrosine provided an iodine transport mechanism which allowed for the metamorphosis and the development of warm bloodedness--a great evolutionary advantage. Zinc from clay was needed for the formation of the first primitive nucleic acids and, later, the presence of zinc in the retina provide the enhanced night vision of the nocturnal predators--a natural advantage. Hence, boron, iodine and zinc can be termed epochal trace elements. Inquiry should be directed towards the possible roles of other trace elements, which may have been epochal in evolution.

Animals↗

[Analysis of trace elements in fructus Ligustri Lucidi and its processed products].

Eleven elements were detected in Fructus Ligustri Lucidi and its processed products. It was found that 4 of them were macro-elements, while 6 were trace elements necessary in human body. The experiment has also shown that the traditional processing has a marked effect on the trace elements in Fructus Ligustri Lucidi.

Drugs, Chinese Herbal↗

[Trace elements and hormones].

The relationship between trace elements and health was discussed at The Seventh International symposium on Trace Elements in Man and Animals in Dubrovnik in May 1990. The following five elements were discussed: aluminium, copper, chromium, selenium and zinc.

Hormones↗

Trace elements and micropollutant anions in the dialysis and reinfusion fluid prepared on-line for haemodiafiltration.

Exposure to the trace elements and micropollutions of tap water may be very considerable in dialysis patients. As few data on trace elements in reinfusion and dialysis fluid for haemodiafiltration (HDF) have been reported, we studied nine trace elements (microg/l; Al, As, Cd, Cr, Cu, Hg, Pb, Se, Zn) and five anions (mg/l; F-, NO2-, NO3-, PO4(3-), SO4(2-)) in tap water, in water after two passages of reverse osmosis (2RO), in dialysate and in on-line prepared reinfusate. NO3- and SO4(2-) were somewhat elevated in our tap water (22.2+/-7.6 and 21.8+/-11.3 mg/l) but decreased (P<0.001) after 2RO (1.4+/-1.5 and 0.9+/-1.1 mg/l); the other anions, which were at a very low level, remained unchanged. All trace elements decreased, with statistical significance only for Al, Cr and Zn from 14.9+/-19.9, 2.6+/-0.6 and 35.1+/-41.1 microg/ to 3.2+/-2.1, 0.2+/-0.2 and 3.5+/-4.8 microg/l, respectively. Due to impurities in concentrate salts for Al (5.4+/-3.1), Cr (0.5+/-0.4) and SO4(2-) (2.4+/-1.8), greater concentrations were found in dialysate and reinfusate than in tap water after 2RO (P<0.03). For all measurements, trace elements and anions were at acceptable levels according to international standards. Simultaneous determinations of trace elements at inflow (Din) and outflow (Dout) of the dialysate as well as in plasma or in whole blood at the beginning of on-line HDF documented Dout/Din>1 for Al, Cu and Zn and a positive gradient between the concentration in blood and dialysate inlet. In conclusion, our dialysate and reinfusate can be considered safe regarding trace elements and micropollution: two passages through reverse osmosis reduces the concentrations of trace elements and anions. The impurities of concentrates are acceptable. Accumulation or depletion of trace elements should be evaluated after longitudinal studies of plasma concentrations.

Anions↗

Speciation of trace elements in biological materials: trends and problems.

In the determination of trace elements in biological materials, speciation is of particular importance as the essential effects or toxicity of an element and its metabolic behaviour depend to a large extent on the chemical forms in which it is present in the organism. Speciation is relatively easy if a property of a particular compound can be measured directly in the sample without interference from the other components of the material, e.g., the enzymic activities of the metallo-enzymes. Another possibility for speciation is immunoassay, which likewise allows direct determination of a particular trace element. At present, however, with most trace elements both fractionation methods and analytical procedures have to be combined and speciation has to be carried out by determining the elemental content in the separated fractions. The methods and apparatus used in taking, storing and preparing the samples can, therefore, not be selected solely according to the requirements of trace element determination, but it is also essential to ensure that the biological structures of the components to be separated remain intact. In this work the need for speciation in the investigation of the toxic and essential effects of trace elements is shown with the help of some examples, and the problems that can occur in the various steps of sampling, storage and sample preparation are discussed.

Animals↗

Trace element contamination of total parenteral nutrition. 2. Effect of storage duration and temperature.

BACKGROUND: Patients who receive home total parenteral nutrition (TPN) frequently are supplied with solutions up to 30 days in advance of anticipated use. The purpose of this study was to determine the stability of trace elements relative to time and temperature conditions, in a typical adult TPN solution stored in a usual home environment by examining variations in delivery of intended trace elements and inadvertent trace element contamination. METHODS: Trace element concentrations were determined using inductively coupled plasma-mass spectrometry technology. The effect of the delivery apparatus, storage duration (36 hours or 30 days) after compounding, and storage temperature (4 degrees C or 20 degrees C) were examined. RESULTS: The delivery apparatus contaminated the delivered TPN solution with cobalt but did not alter trace elements formulated into the TPN solution. Storage duration and temperature significantly decreased three (Zn, Cu, and Mn) of the six trace elements formulated into the TPN solution. Higher temperatures and longer duration of storage accelerated this decrease. Boron, Al, V, Ti, Ba, Sr, and CO were the trace elements that appeared as contaminants during storage. Boron, Al, V, and Ti contamination decreased with higher temperatures and longer duration of storage. CONCLUSIONS: Longer storage duration and higher storage temperature progressively reduced the deliverable concentrations of trace elements specifically formulated into the TPN solution and also of those trace elements that were not formulated into the TPN solution but that appeared as contaminants.

Drug Contamination↗

[Quantification of fecal excretion of trace elements in newborns as expression of fetal intestinal secretion].

OBJECTIVE: Trace elements have acquired major importance in the knowledge concerning corporal composition and in the comprehension of their metabolic participation in organic processes. The objective of this study was to know the concentration of trace elements in biological material (serum, meconium and feces) from preterm and fullterm infants during the neonatal period. PATIENTS AND METHODS: Concentrations of Al, Ca, Cr Cu, Fe, Mg, Mn, Mo, P, Pb and Zn were determined simultaneously in stools and serum by induction coupled argon plasma-atomic-emission spectrometry (ICP) of 12 preterm and 38 fullterm infants. Stools were collected for the 1st (meconium), 10th and 20th day and serum on the 10th day. RESULTS: Compared to serum from preterm infants, fullterm infants had an elevated (p < 0.05) value of potentially toxic trace elements (Al and Pb). Compared meconium from fullterm infants, preterm infants had an elevated excretion of Cu (p < 0.001) and Fe (p < 0.01). Compared to stools from the 10 and 20th day from preterm infants, fullterm infants had an elevated excretion of Fe (p < 0.05). Stool excretion of all of the trace elements increases throughout the days during the neonatal period, whereas Mn decreases. CONCLUSIONS: The mineral content of meconium and stools in newborns rarely has been described and ICP is an interesting method of assessment of trace elements in these biological samples during the neonatal period.

Feces↗

Concentrations of trace elements in sera of newborns, young infants, and adults.

Concentrations of trace elements in newborns, infants, and adults may be significantly different from each other. Serum trace element reference ranges for different age groups are of value for diagnostic purposes. Inductively coupled plasma-mass spectrometry was applied to the determination of the 21 trace elements Ba, Be, Bi, Ca, Cd, Co, Cs, Cu, La, Li, Hg, Mg, Mn, Mo, Pb, Rb, Sb, Sn, Sr, TI, and Zn in a total of 117 sera of individuals representing different age groups. After microwave-assisted acid digestion with high-purity reagents, 20 umbilical cord sera, 5 sera of fully breast-fed infants, 6 sera of formula-fed infants, 66 sera of patients suffering internal diseases, and 20 sera of healthy blood donors were analyzed for trace elements. One serum and two whole-blood reference materials were analyzed for quality control. Experimental concentrations were in good agreement with certified values. Umbilical cord serum concentrations of the essential elements Ca, Co, Cu, and Mg and of the nonessential and toxic elements Ba, Be, Li, Pb, and Sb were elevated compared to the elemental concentrations in the sera of infants and adults. Serum levels of Ba, Ca, Co, Mn, Pb, and Sb of infants were much higher and serum Cu was significantly lower than in adults. Serum Cu increased significantly with age (newborns: 353 microg/L; infants: 755 microg/L; healthy adults: 810 microg/L), whereas for other trace elements no age-dependence could be established.

Adult↗

Technical and clinical aspects of spectrometric analysis of trace elements in clinical samples.

The capabilities of ICP-MS far exceed the slow, single-element analysis of GFAAS for determination of multiple trace elements. Additionally, its sensitivity is superior to that of DCP, ICP, and FAAS. The analytic procedure for ICP-MS is relatively straightforward and bypasses the need for digestion in many cases. It enables the physician to identify the target trace element(s) in intoxication cases, nutritional deficiency, or disease, thus eliminating the treatment delays experienced with sequential testing methods. This technology has its limitations as well. The ICP-MS cannot be used in the positive ion mode to analyze with sufficient sensitivity highly electronegative elements such as fluorine, because F+ is unstable and forms only by very high ionization energy. The ICP mass spectrometers used in most commercial laboratories utilize the quadrupole mass selector, which is limited by low resolution and, thus, by the various interferences previously discussed. For example, when an argon plasma is used, selenium (m/e 80) and chromium (m/e 52) in serum, plasma, and blood specimens are subject to polyatomic and molecular ion interferences. Low-resolution ICP mass spectrometers can therefore be used to analyze many trace elements, but they are not universal analyzers. High-resolution ICP-MS can resolve these interferences, but with greater expense. With the advent of more research and development of new techniques, some of these difficulties may be overcome, making this technique even more versatile. Contamination during sample collection and analysis causes falsely elevated results. Attention and care must be given to avoid contamination. Proper collection devices containing negligible amounts of trace elements should be used. Labware, preferably plastic and not glass, must be decontaminated prior to use by acid-washing and rinsed with [table: see text] de-ionized water. A complete description of sample collection and contamination has been written by Aitio and Jarvisalo as well as by Chan and Gerson. Lutz et al observed the ranges in blood shown in Table 4. We have adopted the ranges listed in Table 5 in urines of healthy, ambulatory, and community-dwelling individuals through a limited in-house study and review of literature. In conclusion, differentiation of trace element abnormalities (primary intoxication or disease versus secondary underlying disease) can be made only by utilizing results from trace element analyses in clinical specimens, medical history, and careful observation of symptoms. Repeat analysis on a second specimen collection is recommended when contamination is suspected.

Body Fluids↗

Should chronic obstructive pulmonary disease outpatients be routinely evaluated for trace elements?

We searched for serum concentrations of trace elements and correlated them to malondialdehyde (MDA), which is an indirect marker of oxidative stress, in order to clarify if routine evaluation is necessary in chronic obstructive pulmonary disease (COPD) outpatients. Serum concentrations of copper (Cu), zinc (Zn), and magnesium (Mg) were determined by atomic absorption spectrophotometry and iron (Fe) by a ILLab 1800 autoanalyzer with ILLab test kits. Serum MDA concentrations were detected in terms of TBARS (thiobarbituric acid reactive substances) spectrophotometrically. Serum Cu, Zn, Mg, Fe, and MDA concentrations in patient and control groups were all in the normal reference range. The results respectively were as follows: Cu:123 +/- 29.2 and 122.2 +/- 23.4 microg/dL; Zn: 87.8 +/- 17.8 and 96.9 +/- 12.9 microg/dL; Mg: 2.3 +/- 0,5 and 2.04 +/- 0.28 mg/dL; Fe: 73.8 +/-35.5 and 80.7+/-51.2 microg/dL; MDA: 1.09+/-0.11 and 0.95+/-0.06 nmol/L. MDA was not correlated to Cu, Zn, Mg, or Fe (p>0.05 for all). The serum Zn concentration of COPD group was lower than the control group (p=0.042), whereas the Mg concentration was higher (p=0.021). There was no statistical difference in other study parameters. Oxidative stress was not increased in clinically stable, regularly treated COPD patients. Although there was no deficiency in trace elements (Cu, Fe, Mg, and Zn), serum Zn was close to the lower limit of the reference value. There is no need for routine evaluation of trace elements in clinically stable, regularly treated COPD outpatients.

Adult↗

A survey of trace elements in pteridophytes.

Concentration of 11 trace elements (Ca, Sc, Cr, Fe, Co, Zn, Rb, Cs, Ba, La, and Ce) in 96 pteridophytes (fern and fern ally species) was determined by instrumental neutron activation analysis to evaluate a concentration range for each element and also to find species characteristic in the uptake of trace elements. Asplenium trichomanes was found to accumulate Sc, Cr, and Co to the highest concentrations among 96 pteridophytes. The highest concentration of Ca and Zn was observed for Asplenium obscurum. The other Pteridophytes exhibited only one element whose concentration was the highest. A positive correlation was found between the concentrations of Fe and Sc, and also between the concentrations of Cr and Co. The remarkable accumulation of lanthanides (La and Ce) was observed mainly in diversifying genera (Polystichum and Dryopteris in Dryopteridaceae, Diplazium in Woodsiaceae, and Asplenium in Aspleniaceae).

Metals, Rare Earth↗

Bermudagrass management in the southern Piedmont, USA: IX. Trace elements in soil with broiler litter application.

An understanding of the long-term cycling of trace elements in soil with broiler litter fertilization under various forage utilization strategies is needed to develop sustainable agricultural production systems. We evaluated differences in Cu, Mn, Zn, and six other trace elements in response to 5 yr of bermudagrass [Cynodon dactylon (L.) Pers.] management varying in fertilization and harvest strategies on a Typic Kanhapludult in Georgia. Chicken (Gallus gallus) broiler litter was a significant source of trace elements that led to 3.4 +/- 0.5 times higher Cu, 2.0 +/- 0.3 times higher Mn, and 2.1 +/- 0.2 times higher Zn in the surface 3 cm of soil than when forage was fertilized inorganically. There were variable effects of broiler litter fertilization on other trace elements, depending upon element, depth of sampling, and forage utilization strategy. Concentrations of all trace elements in soil were below levels considered toxic to plants. Soil at a depth of 0 to 3 cm under grazed paddocks had 33 +/- 5% greater Cd, 18 +/- 1% greater Cr, 53 +/- 24% greater Cu, and 24 +/- 7% greater Zn compared with unharvested and hayed management. Trace elements in soil were unaffected whether forage was unharvested or removed as hay. These results suggest that broiler litter is a significant source of several trace elements and that ruminant processing of forage and subsequent deposition of excreta on the paddock allow these trace elements to accumulate more at the soil surface where they might interact with the high concentration of organic matter.

Agriculture↗

The role of glutathione in bile secretion of endogenous trace elements in rats.

To evaluate the role of glutathione in biliary secretion of endogenous trace elements, we quantitated trace element output rates by proton-induced x-ray emission under various conditions with altered biliary glutathione secretion and hepatic glutathione content in the rat. Treatment with phenobarbital (80 mg/kg body weight, 4 days), ethanol (0.9 gm/kg body weight, 4 days), or diethylmaleate (3.9 mmol/kg body weight) resulted in changes in biliary glutathione secretion of +114%, -56%, and -95%, respectively, and in hepatic glutathione content of -0%, +25%, and -86%, respectively, when compared with control values. Biliary glutathione level was below detection limits in mutant Groningen Yellow Wistar rats, whereas hepatic glutathione content was increased by 114% in these animals. Glutathione secretion showed a linear relationship with bile flow when data from all experiments were included in the analysis; the apparent choleretic activity of glutathione was 67 microliters/mumol. Six trace elements (iron, zinc, copper, manganese, molybdenum, bromine) could always be detected in bile. Potassium and calcium were measured for comparative purposes. No relation was found between biliary trace element secretion and hepatic glutathione content. Biliary output rates of iron, molybdenum, and bromine correlated, albeit poorly, with biliary glutathione efflux (r values: iron, 0.67; molybdenum, 0.40; bromine, 0.53; respectively). Copper, manganese, and zinc secretion did not show any consistent relationship with glutathione secretion. The secretion rates of iron, molybdenum, and bromine, like that of calcium, showed a highly significant correlation with bile flow (r values: iron, 0.89; molybdenum, 0.75; bromine, 0.80; and calcium, 0.90; respectively, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Investigation of trace element content of cheese.

Nine trace elements (Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd, Pb) were determined in cheese by atomic absorption spectrophotometry with electrothermal atomization in a graphite tube, using the ashing procedure. Associations among mineral constituents were studied by means of principal component analysis, which allows determination of interdependences among trace elements in foods. A test for normality was used to investigate monovariate distributions, in order to estimate the symmetry of data vector. The correlation matrix was used as a starting matrix for principal component analysis; nine variables were reduced to four principal components. The clusters of elements appear to be determined by their origin.

Cheese↗

Iron status influences trace element levels in human blood and serum.

Food is the main source of trace elements for the general population. The gastrointestinal absorption of certain trace elements, e.g., cadmium, is strongly influenced by iron (Fe) status. This factor may also be relevant for the bioavailability of other trace elements. Therefore, we investigated relationships between Fe status indicators and trace element concentrations in blood and serum of 234 boys and girls at ages 15 and 17 years. Fe status was measured using serum ferritin (S-Ft), soluble transferrin receptor in serum (sTfR), and the ratio sTfR/S-Ft. The trace elements we investigated were, in blood, cadmium, cobalt, copper, zinc, selenium, rubidium, mercury, and lead, and, in serum, cobalt, copper, zinc, selenium, rubidium, tungsten, mercury, and lead. We found inverse correlations between Fe status and blood cadmium, blood or serum cobalt, or blood copper. There were positive correlations between Fe status and mercury concentrations. Selenium was positively correlated with sTfR. The relationships between Fe status and lead were equivocal. There were fewer correlations for serum than for blood, but the inverse relationships between Fe status and cobalt were equally strong in serum and blood. We found only occasional, and perhaps spurious, correlations with zinc, rubidium, and tungsten. In conclusion, previous indications that cadmium, cobalt, and copper are absorbed by transport mechanisms similar to that of Fe are supported by this study. Strong positive correlations between Fe status and mercury concentrations remain to be explained.

Adolescent↗