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PubMed2006

Imaging and speciation of trace elements in biological environment.

Mineral elements, often at the trace level, play a considerable role in physiology and pathology of biological systems. Metallogenomics, metalloproteomics, and metallomics are among the emerging disciplines which are critically dependent on spatially resolved concentration maps of trace elements in a cell or tissue, on information on chemical speciation, and on that on metal-binding coordination sites. The mini-review discusses recent progress in analytical techniques for element profiling on the genome scale, biological trace element imaging, and probing, identification and quantification of chemical species in the biological environment. Imaging of the element distribution in cells and tissue sections is becoming possible with sub-micrometer spatial resolution and picogram-level sensitivity owing to advances in laser ablation MS, ion beam and synchrotron radiation X-ray fluorescence microprobes. Progress in nanoflow chromatography and capillary electrophoresis coupled with element specific ICP MS and molecule-specific electrospray MS/MS and MALDI enables speciation of elements in microsamples in a complex biological environment. Laser ablation ICP MS, micro-SXRF, and micro-PIXE allow mapping of trace element distribution in 1D and 2D proteomics gels. The increasing sensitivity of EXAFS and XANES owing to the use of more intense synchrotron beams and efficient focusing optics provide information about oxidation state, fingerprint speciation of metal sites and metal-site structures.

Environmental Pollution↗

PubMed1975

Variability in mineral and trace element content of dairy cattle feeds.

Trace element content of feeds is extremely variable compared to total digestible nutrients or protein. Differences are wide between low and high values for many trace elements within a given type of feed. Coefficients of variation for forages range from 42 to 100%. Summary data are given for both major and trace elements. Problems in supplementation are discussed. Amounts for some elements are skewed with relatively few samples around the mean and over 60% below the mean. Suggested mineral allowances for dairy cows are listed. Under current supplementation, zinc is the trace element most likely to be limiting and manganese the least likely. Iron, copper, cobalt, and iodine may be limiting in some cases. Needs of research and applied nutrition are presented.

Aluminum↗

PubMed2002

Use of stable isotopes to assess the bioavailability of trace elements: a review.

The bioavailability (utilization) of trace elements is very variable, depending on the characteristics of the element itself, composition of the diet, gastrointestinal conditions and other physiological factors. To derive dietary recommendations and make use of emerging information on diet-gene interactions relating to nutritional requirements for trace elements, methods for assessing bioavailability are required. The trace elements of particular interest include iron, zinc, selenium and copper because of problems of deficiency, purported links with chronic diseases, and the growing market in fortified foods and supplements. The absorption and subsequent metabolism of trace elements can be monitored using stable isotope tracers, but there are difficulties associated with this approach. Although radioisotopes offer many advantages over stable isotopes, their use is restricted due to safety and ethical issues. The difficulties and limitations of methodologies associated with labelling of trace elements in foods with stable isotopes, design of human studies to generate results that predict bioavailability, and detection and quantification of stable isotopes in biological samples are discussed.

Biological Availability↗

PubMed2004

Microbial acidification and pH effects on trace element release from sewage sludge.

Leaching of sludge-borne trace elements has been observed in experimental and field studies. The role of microbial processes in the mobilization of trace elements from wastewater sludge is poorly defined. Our objectives were to determine trace element mobilization from sludge subjected to treatments representing microbial acidification, direct chemical acidification and no acidification, and to determine the readsorption potential of mobilized elements using calcareous sand. Triplicate columns (10-cm diameter) for incubation and leaching of sludge had a top layer of digested dewatered sludge (either untreated, acidified with H2SO4, or limed with CaCO3; all mixed with glass beads to prevent ponding) and a lower glass bead support bed. Glass beads in the sludge layer, support layer or both were replaced by calcareous sand in four treatments used for testing the readsorption potential of mobilized elements. Eight sequential 8-day incubation and leaching cycles were operated, each consisting of 7.6 d of incubation at 28 degrees C followed by 8 h of leaching with synthetic acid rain applied at 0.25 cm/h. Leachates were analyzed for trace elements, nitrate and pH, and sludge layer microbial respiration was measured. The largest trace element, nitrate and S losses occurred in treatments with the greatest pH depression and greatest microbial respiration rates. Cumulative leaching losses from both microbial acidification and direct acidification treatments were > 90% of Zn and 64-80% of Cu and Ni. Preventing acidification with sludge layer lime or sand restricted leaching for all trace elements except Mo. Results suggested that the primary microbial role in the rapid leaching of trace elements was acidification, with results from direct acidification being nearly identical to microbial acidification. Microbial activity in the presence of materials that prevented acidification mobilized far lower concentrations of trace elements, with the exception of Mo. Trace elements mobilized by acidification were readsorbed by calcareous sand when present.

Calcium↗

PubMed1977

The biologic bases for using hair and nail for analyses of trace elements.

Sampling of human beings for trace element content can be a complex and costly procedure. The use of hair and nails simplifies the process and it is for this reason that such samples are extensively used. The primary consideration, however, is not how easily the samples can be collected nor even how accurately trace elements can be measured in hair and nails; rather, it is what do the values mean, i.e., to what extent does the measured level reflect the concentration and/or activity of the element in other parts of the body? The structure and histogenesis of hair and nails are discussed in relation to mechanisms by which trace elements are incorporated into these tissues. Problems of contamination in vivo are also considered. A résumé of current literature is presented, considering the trace elements that are appropriate for measurement in samples of human hair and nail and some of the problems involved in analysis.

Animals↗

PubMed1979

[Interactions of toxic trace elements with special regard to selenium].

The significance of the trace elements in nutrition is often decisively affected by the interaction of trace elements with other trace elements and of trace elements with other substances. These processes, which include synergistic and antagonistic effects, are of great importance not only to the essentiality, but also to the toxicity of trace elements. There is considerable experience with interactions of essential elements. There is considerable experience with interactions of essential elements or of elements in essential concentrations. On contrast, there is a scarcity of information pertaining to toxic effects that are influenced by synergisms and antagonisms. This situation is illustrated by some examples and especially by the role of selenium. It is shown that these problems deserve closer attention.

Cations↗

PubMed1988

[Clinical studies on renal function and trace elements].

The serum trace elements aluminum (Al), zinc (Zn), nickel (Ni), and manganese (Mn), and creatinine clearance (Ccr) were measured in twenty normal volunteers and 40 patients; 5 patients had mild renal dysfunction, 10 patients had chronic renal failure 5 patients had uremia and 20 patients had been undergoing chronic hemodialysis. Serum Al, Cu, Zn, Ni and Mn were measured with a flameless atomic absorption spectrophotometer. Serum Al levels increased with decrement of the Ccr value. The serum Al level was abnormally high in chronic hemodialysis patients. The serum Cu level in the patients was similar to that in the healthy subjects. Serum Zn, Ni and Mn levels decreased with the decrement of the creatinine clearance level. These results suggest that measurement of serum Al, Zn, Ni and Mn levels can be used as an indication of renal function clinically. In conclusion, serum Al, Zn, Ni and Mn levels are clinical indicators of renal function.

Aluminum↗

PubMed1977

Trace element analysis: a diagnostic tool.

Human body continuously assimilates a variety of elements from the environment and the concentration of these elements in blood is regulated by means of various homeostatic mechanisms. Some of the elements, though present in very small amounts perform highly specialized functions in initiating many biochemical reactions. These elements, known as essential trace elements, are closely related to human diseases as their deficiency or excess induces physiological changes. Many diseases such as hypertension, atherosclerosis, diabetes etc are related to trace element imbalance. Therefore the measurement of trace elements in body fluids and tissues can be effectively employed for diagnostic tests.

Animals↗

PubMed2005

Multitracer screening: brain delivery of trace elements by eight different administration methods.

Trace elements are closely associated with the normal functioning of the brain. Therefore, it is important to determine how trace elements enter, accumulate, and are retained in the brain. Using the multitracer technique, which allows simultaneous tracing of many elements and comparison of their behavior under identical experimental conditions, we examined the influence of different administration methods, i.e., intravenous (IV), intraperitoneal (IP), intramuscular (IM), subcutaneous (SC), intracutaneous (IC), intranasal (IN), peroral (PO), and percutaneous (PC) administration, on the uptake of trace elements. A multitracer solution containing 16 radionuclides (i.e., 7Be, 46Sc, 48V, 51Cr, 54Mn, 59Fe, 56Co, 65Zn, 74As, 75Se, 83Rb, 85Sr, 88Y, 88Zr, 95mTc, and 103Ru) was used. The results indicated that the 83Rb brain uptake rate with intranasal administration was approximately twice those obtained with the other administration methods. This result indicated that a portion of Rb was delivered into the brain circumventing the blood circulation and that delivery could be accomplished mainly by olfactory transport. Multitracer screening of trace element delivery revealed differences in brain uptake pathways among administration methods.

Administration, Cutaneous↗

PubMedDate not supplied

Microphthalmia (mi) mice display an aberrant bone trace element composition.

It has been recognized that bone trace element composition analysis provides clues when analyzing bone-related physiological conditions. Increasing numbers of bone-related genetic diseases have been identified recently. In this study, we have analyzed bone trace element composition in a genetic mutant animal model. Mutations in the mouse microphthalmia (mi) gene affect the development of a number of cell types, including melanocytes, mast cells, and osteoclasts. Previous studies have shown that different alleles of the mi locus show osteopetrosis. In order to gain insights into the effects of a particular genetic defect on bone trace element composition and bone structure, we performed bone trace element composition analysis using inductively coupled plasma atomic emissions spectrometry (ICP-AES). Marked changes in bone trace element levels were found in vertebrate bones of mi mutant mice. The implications and possible applications of bone trace element analysis will be discussed in this article.

Animals↗

PubMed2001

Interaction of chemical species with biological regulation of the metabolism of essential trace elements.

Variations in the chemical speciation of dietary trace elements can result in the provision of different amounts of these micronutrients to the organism and might thus induce interactions with trace-element metabolism. The chemical species of Zn, Fe, Cu, and Mn can interact with other components of the diet even before reaching the site of absorption, e.g. by formation of poorly soluble complexes with phytic acid. This might considerably modify the amount of metabolically available trace elements; differences between absorptive capacity per se toward dietary species seems to be less important. Homeostasis usually limits the quantities of Zn, Fe, Cu, and Mn transported from the gut into the organism, and differences between dietary species are largely eliminated at this step. There is no homeostatic control of absorption of Se and I, and organisms seem to be passively exposed to influx of these micronutrients irrespective of dietary speciation. Inside the organism the trace elements are usually converted into a metabolically recognizable form, channeled into their biological functions, or submitted to homeostatically controlled excretion. Some dietary species can, however, be absorbed as intact compounds. As long as the respective quantities of trace elements are not released from their carriers, they are not recognized properly by trace element metabolism and might induce tissue accumulation, irrespective of homeostatic control.

Animals↗

PubMed1981

Intravenous solution compatibility and filter-retention characteristics of trace-element preparations.

The compatibility of recently published AMA formulations of the four trace-element injections (zinc, copper, chromium, and manganese) with a representative total parenteral nutrition (TPN) formulation and commonly used intravenous solutions was evaluated in glass and plastic containers. The effect of in-line filtration on trace-element concentration was also studied. Individual metal-ion concentrations, pH, color, and clarity were measured at 0-, 12-, 24-, and 48-hour intervals following mixture in TPN, 5% dextrose injection, 0.9% sodium chloride injection, and 8.5% amino acid injection (Travasol, Travenol Laboratories). Multiple trace elements were studied in one-liter glass bottles of 5% dextrose and 0.9% sodium chloride injection. Trace-element contaminants were measured in the intravenous solutions and trace-element injections. The four trace-element preparations were added individually and in combination to the solutions in plastic or glass containers. The trace-element admixtures were passed through in-line i.v. filters (IVEX-2, Abbott Laboratories) during a three-hour period at controlled-flow rates. Concentrations of trace elements remained within 99% confidence limits in all i.v. solutions, with both individual trace elements and combinations of the four trace elements. Trace-element concentrations did not change when the admixtures were passed through the in-line filter unit. It is concluded that there are no obvious compatibility problems associated with admixture nor any detectable retention by the i.v. filter of trace elements.

Drug Incompatibility↗

PubMed2000

Trace element contamination in Antarctic ecosystems.

Data concerning trace element concentrations in both abiotic and biotic components of the Antarctic ecosystems are summarized here to be used as a first background database for pollution detection. Antarctic ancient ice and snow cores have been used to assess past and present-day changes in global atmospheric levels of certain trace elements. Concentrations of Pb, Cd, and Hg in the Antarctic tropospheric cell have varied according to glacial and interglacial periods before humans began to contaminate the atmosphere with these metals. Based on data of Pb concentrations in the Antarctic ancient ice cores and samples of recent snow, most of the Pb in Antarctica is anthropogenic. Moreover, this metal has decreased in recent years as a consequence of the reduced use of leaded gasoline in countries of the Southern Hemisphere. Reliable experimental and field data have indicated, however, that human activity in Antarctica contributes significantly to increasing atmospheric Pb levels in this continent, whereas the environmental impact of other metals such as Cd, Zn, or Hg is restricted to the area a few hundreds of meters about the anthropogenic source. Trace element concentrations in Antarctic abiotic matrixes are generally at ultratrace levels, challenging analytical detection limits and increasing the risk of unwanted contamination. Pb and Hg concentrations in Antarctic snow, surficial soil, air, and marine sediment have been considered as the lowest concentrations ever reported. Conversely, concentrations in Antarctic biota, are comparable to those from polar and temperate areas of the Northern Hemisphere, in particular Cd and Hg. Environmental and biological factors favoring a greater metal accumulation by Antarctic biota are discussed. Growth rate of the organisms and detoxification mechanisms (e.g., metallothioneins, molting cycles) are largely affected by the extreme environmental conditions in Antarctica (water supply, temperature regimen, light availability) that probably interfere with uptake, storage, and excretion of trace elements by organisms. On the other hand, environmental factors such as the upwelling of Cd-rich waters and local volcanism undoubtedly increase the bioavailability of metals in the Antarctic environment. In this context, several Antarctic organisms such as fish, mollusks, lichens, and mosses have been proposed as suitable biomonitors, and their trace element concentrations have been suggested as baselines. Structure and dynamics of Antarctic ecosystems as well as quantifying metal point sources and long-range atmospheric transport require in-depth studies to improve the assessment of human impact in Antarctica.

Animals↗

PubMed1987

Trace element metabolism in the developing avian embryo: a review.

Trace element metabolism in the developing avian embryo involves a variety of interrelated processes beginning with metal deposition in the nascent egg. Vitellogenin, the yolk precursor protein, plays a fundamental role in the transport of trace elements from hepatic stores in the hen to the developing oocyte, where it facilitates the uptake and storage of metals in the egg yolk. Egg white proteins such as ovalbumin and conalbumin (ovotransferrin) may function in an analogous manner by effecting the transfer of trace elements from the oviduct to the egg. The uptake and metabolism of trace elements by the developing embryo are mediated by the extraembryonic membranes, predominantly the yolk sac, which are in direct contact with the egg contents. Specific metal-binding proteins play important roles in the interorgan transport, cellular uptake, and intracellular partitioning of trace elements in the developing embryo. Models are proposed to explain the deposition of trace elements in the newly formed egg and the uptake and transfer of trace elements from the egg yolk and white to the tissues of the developing embryo and its associated membranes.

Animals↗

PubMed1989

[Trace elements in the serum and cancerous tissue in patients with trophoblastic carcinoma].

In the serum and cancer tissue of 155 patients with trophoblastic tumor and in 114 patients with benign or malignant gynecologic tumor, 22 elements (17 trace and 5 major elements) were determined by neutron activation analysis. The serum and tissue level of Cr, the serum Zn level in patients with hydatidiform mole was significantly higher than that of the control group (P less than 0.01). The serum Se level in Patients with invasive mole and choriocarcinoma was lower (less than 1.0 mumol/l), but Cu/Zn ratio was higher (greater than 2.0) in comparison with that of the controls (P less than 0.01). With remission of the disease levels of the essential trace elements went up approaching the normal levels. There was a negative relationship between the serum Zn level and hCG content. The authors point out that the low level of Zn and Se, the high level of Cr may be related to the development of trophoblastic tumors.

Adult↗

PubMed1996

[Renal disease and trace elements].

Correlation between renal disease and trace elements includes following two types; 1) Renal failure due to excess of trace element intake into the body, such as itai-itai disease or heavy metal intoxication. 2) Disturbances of trace elements in patients with chronic renal failure, such as aluminum dementia and aluminum-related bone disease. Itai-itai disease occurred by water pollution with cadmium. Cadmium causes Fanconi syndrome in the kidney and osteomalasia in person, especially in old women, who were living near the riverside. Recently, we have shown that an itai-itai disease model can be made using rats by long-term intravenous injection of cadmium chloride. In patients with chronic renal failure, aluminum dementia and aluminum related bone disease were reported. However, aluminum dementia has disappeared by using reverse osmosis system for making dialysate. Fluoride should be one of ions which must be paid attention, because excess of fluoride cause mottled tooth and osteosclerosis. It may be dangerous to add fluoride into tap water system for the purpose of preventing decayed tooth, because fluoride retention in the serum may occur in patients with chronic renal failure.

Animals↗

PubMed1985

Trace elements in chemical evolution, I.

Research on trace elements in chemical evolution is reviewed from three points of view. They are: the origin of the essentiality of trace elements in present biological systems; the possible roles of trace elements in chemical evolution; and the origin of enzymatic activity with metal ions, i.e., the origin of metalloenzymes.

Amino Acids↗

PubMedDate not supplied

Trace element speciation in poultry litter.

Trace elements are added to poultry feed for disease prevention and enhanced feed efficiency. High concentrations are found in poultry litter (PL), which raises concerns regarding trace element loading of soils. Trace metal cation solubility from PL may be enhanced by complexation with dissolved organic carbon (DOC). Mineralization of organo-As compounds may result in more toxic species such as As(III) and As(V). Speciation of these elements in PL leachates should assist in predicting their fate in soil. Elemental concentrations of 40 PL samples from the southeastern USA were determined. Water-soluble extractions (WSE) were fractionated into hydrophobic, anionic, and cationic species with solid-phase extraction columns. Arsenic speciation of seven As species, including the main As poultry feed additives, roxarsone (ROX; 3-nitro-4-hydroxyphenylarsonic acid) and p-arsanilic acid (p-ASA; 4-aminophenylarsonic acid), was performed by ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS). Total As concentrations in the litter varied from 1 to 39 mg kg(-1), averaging 16 mg kg(-1). Mean total Cu, Ni, and Zn concentrations were 479, 11, and 373 mg kg(-1), respectively. Copper and Ni were relatively soluble (49 and 41% respectively) while only 6% of Zn was soluble. Arsenic was highly soluble with an average of 71% WSE. Roxarsone was the major As species in 50% of PL samples. However, the presence of As(V) as the major species in 50% of the PL samples indicates that mineralization of ROX had occurred. The high solubility of As from litter and its apparent ready mineralization to inorganic forms coupled with the large quantity of litter that is annually land-applied in the USA suggests a potential detrimental effect on soil and water quality in the long term.

Agriculture↗