Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CHROMIUM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63Linked to original sources

Evaluation of the selenium and chromium content of plant foods.

In the present study the selenium and chromium content of different plant foods such as fruits, greens, flowers, vegetables, dried fruits, spices, condiments, cereals and pulses were analysed. The selenium values for cereals indehiscent vegetables, root vegetables, stem vegetables, pulses, fleshy vegetables, greens, fleshy fruits, condiment seeds, spices and dried fruits ranged between 24.2-32.16, 2.4-18.9, 2.8-21.5, 3.0-32, 48.7-92.5, 1.25-9.5, 3.0-8.2, 2.0-9.4, 6.2-66.2, 6.2-17.5 and 3.5-16.8 micrograms/100 g respectively. The chromium values for the same ranged between 48.2-52.6, 31.0-45, 21.2-25.7, 23.7-62.8, 15.0-43.5, 20.4-65, 14.2-42.1, 14.25-46.7, 58.4-150 and 96-168 micrograms/100 g respectively. Thus dried fruits have the highest chromium content and pulses the highest selenium content.

Chromium↗

The effects of aluminum, iron, chromium, and yttrium on rat intestinal smooth muscle in vitro.

The modification of peristaltic activity in the presence of several metal ions has been investigated in the rat intestine by the isolated organ technique. The metals tested modify the intestinal movements: aluminum, chromium, and yttrium cause a decrease of amplitude, while iron showed no effect. By use of microscopic techniques, the presence of yttrium hydroxide was observed in the intestinal tissues. Iron also appears as a precipitate outside of the intestinal serosal, which may explain why iron did not modify the peristaltism. Chromium and aluminum were not apparent to microscope, despite being detected and quantified in the tissues by means of atomic emission spectrometer. We conclude that the trivalent ions of these elements may operate differently on the mechanisms of intestinal contractions: yttrium precipitates in intercellular spaces, iron precipitates outside the intestines, and chromium and aluminum remain in solution and are distributed homogeneously in the smooth intestinal muscle.

Aluminum↗

Blood chromium determination in assessing reference values in an unexposed Mediterranean population.

Plasma chromium levels were determined in 243 healthy subjects. The study group consisted of 134 men and 109 women, ages 19-71 yr, all residing in Barcelona in northeastern Spain. The study was designed to assess the reference levels for plasma chromium and to investigate its relationships to age and sex. The assays were performed by means of a graphite-furnace atomic absorption spectrometer. The mean plasma chromium concentration was 3.01 +/- 1.45 nmol/L, ranging from 0.6 to 6 nmol/L. The upper reference values in the 0.95 percentile for this population was 5 nmol/L. No significant differences were observed with respect to the subjects' sex.

Adult↗

Interleukin-1alpha-induced changes in chromium-51 absorption, tissue retention, and urinary excretion in rats.

The effects of interleukin-1 alpha (IL-1alpha) on chromium-51 absorption, tissue retention, and urinary excretion were studied in adult male Sprague-Dawley rats. Ten rats were deprived of food for 12 h, injected intraperitoneally with mouse recombinant IL-1alpha (1 microg/kg of body weight in phosphate-buffered saline [PBS]) or control (0.1% bovine serum albumin [BSA] in PBS). Two hours after dosing with the IL-1alpha, rats were fed 50 microL (200 microCi, 0.36 microg Cr) of 51CrCl3 by micropipet. Blood was collected from the tail at 0.25, 0.5, 1, 2, and 4 h. Six hours after dosing with 51CrCl3, rats were exsanguinated and blood and tissues were sampled. The IL-1alpha significantly decreased chromium-51 in blood, urine, and some tissues compared to the control. The decreased absorption, retention, and urinary excretion of chromium-51 from 51CrCl3 in this study may be due to IL-1alpha-mediated increases in the production of prostaglandins and/or decreased production of gastric acid.

Animals↗

Physiological chromium determination in serum by Zeeman graphite furnace atomic absorption spectrometry. A serious challenge.

Several authors have already underlined chromium implication in glucose and lipids metabolism of humans. In this field, physiological chromium determination in serum could be helpful, but the discrepancies reported in numerous papers are confusing. Here we report some results obtained by Zeeman correction Graphite Furnace Atomic Absorption Spectrometry. This technique includes a dilution of serum with 12.5 mM ultrapure nitric acid and 0.25% Triton X-100 (final concentrations). Some main features can be outlined: (1) the contamination constitutes a serious drawback and (2) the sensitivity of the technique is critical (characteristic mass found: 1.76 pg/0.0044 A.s). Our results obtained from 27 healthy subjects (2.01 +/- 0.77 nmol/L) agree with most recent studies and indicate that serum chromium level does not seem to be sex-related.

Chromium↗

Effect of chromium nicotinic acid supplementation on selected cardiovascular disease risk factors.

The effects of daily supplemental chromium (200 micrograms) complexed with 1.8 mg nicotinic acid on plasma glucose and lipids, including total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides, were assessed in 14 healthy adults and 5 adults with noninsulin-dependent diabetes mellitus (NIDDM) using a double-blind crossover study with 8-wk experimental periods. Eight of the 14 healthy subjects and all 5 subjects with NIDDM also underwent an oral glucose tolerance test with assessment of 90 min postprandial plasma glucose and insulin concentrations. No statistically significant effects of chromium nicotinic acid supplementation were found on plasma insulin, glucose, or lipid concentrations, although chromium nicotinic acid supplementation slightly lowered fasting plasma total and LDL cholesterol, triglycerides, and glucose concentrations, and 90-min postprandial glucose concentrations in individuals with NIDDM.

Administration, Oral↗

Determination of urinary zinc, chromium, and copper in steel production workers.

The aim of our investigation was to determine the concentrations of Cu, Zn, and Cr in urine samples under routine clinical laboratory conditions. To assess the reliability of these methods, critical factors such as detection limit(s), calibration range(s), cost, accuracy, and precision were studied. Our method was employed for the quantitative determination of zinc, chromium, and copper in urine samples from steel production and quality control (QC) workers and healthy unexposed controls. After pretreatment with acids, the samples were digested via a microwave oven. Zinc was determined by flame absorption spectrophotometry (FAAS), whereas chromium and copper were determined by a graphite-furnace atomic absorption spectrophotometry (GFAAS). Our results indicate that urinary zinc, chromium, and copper levels of the exposed workers are significantly higher than those of the controls. The possibility that these metals are involved in the etiology of diseases is discussed and recommendations are made to improve workplace ventilation and industrial hygiene practices.

Calibration↗

Increased DNA-protein crosslinks in lymphocytes of residents living in chromium-contaminated areas.

It has been known for a number of years that chromium-containing mine slags were used as landfill in residential areas of Hudson County, New Jersey. Since one of the major lesions induced in intact cells by chromate is the DNA-Protein crosslink, we have used this lesion as a biomarker of biological effect of chromium (Cr) exposure. We have previously developed a sensitive and easy-to-perform assay to detect DNA-Protein crosslinks, based on the selective K SDS precipitation of DNA associated with protein. We examined the levels of DNA-Protein crosslinks in peripheral blood mononuclear cells of 33 individuals determined to be at risk for chromium exposure by virtue of their residence in Hudson County and their urinary Cr levels. These data were compared to the levels of DNA-Protein crosslinks among 49 controls who resided in noncontaminated areas. A complete clinical examination and urine analysis did not show any Cr-related abnormalities among the exposed population. The mean DNA-Protein crosslink level in the lymphocytes of the exposed group was 1.3 +/- 0.5% (SD), whereas the unexposed group had 0.8 +/- 0.4% (p < 0.001), after adjustment for age, gender, race, smoking, and weight. Further studies in this population are needed to confirm the possible association between the high levels of DNA-Protein crosslink and Cr exposure.

Adult↗

Insulin potentiating factor and chromium content of selected foods and spices.

An unidentified factor that potentiates the action of insulin in glucose metabolism was investigated in selected foods and spices. Chromium content of these foods and spices was also determined. Foods and spices were extracted with 0.1N NH4OH (1:20, w/v) and the supernatants assayed for insulin potentiation activity in the rat epididymal fat cell assay. Among the selected foods, tuna fish, peanut butter, and vanilla ice cream had some insulin potentiating activity. Among the spices, apple pie spice, cinnamon, cloves, bay leaves, and turmeric potentiated insulin activity more than three-fold. Chromium concentration of foods ranged from 1 to 145 ng/g, and spices ranged from 4 to 1818 ng/g. Insulin potentiating activity of foods and spices did not correlate with total chromium. Spices are generally used for flavor and taste in food preparations, but cinnamon, cloves, bay leaves, and turmeric may have an additional role in glucose metabolism.

Animals↗

Study of chromium-containing proteins in subcellular fractions of rat liver by enriched stable isotopic tracer technique and gel filtration chromatography.

Ten male Wistar rats were intravenously injected with a single approximately physiological dose of enriched stable isotopic Cr-50 tracer solution (200 ng (50)Cr(3+)/100 g body wt). The fundamental distribution patterns of the chromium-containing proteins in the nucleic, mitochondrial, lysosomal, microsomal, and cytosolic subcellular fractions of the rat liver were investigated by means of Sephadex G-100 gel chromatography combined with neutron activation analysis via (50)Cr (n, gamma) (51)Cr reaction. In total, nine kinds of Cr-containing proteins were found in the five subcellular fractions, whose relative molecular masses were 96.6+/-6.2, 68.2+/-1.4, 57.9+/-4.7, 36.6+/-1.2, 24.2+/-1.8, 14.0+/-1.5, 8.8+/-0.6, 6.9+/-0.4, and 4.2+/-0.4 kDa. Approximately 64.5% of Cr proteins accumulated in the cytosolic fraction. The second enriched part was the nucleic fraction; about 12.2% Cr proteins were stored in this section. The 4.2-kDa molecular mass might contain the so-called low molecular weight chromium-containing substance; however, in this research, it was only observed in the mitochondria, lysosome, and microsome. In the mitochondrial fraction, most of the Cr proteins were present as relatively low molecular weight substances: about 56% of chromium-containing proteins had molecular masses < or =6.9 kDa. Nevertheless, more than 69% of Cr-containing proteins were observed with molecular masses > or =57.9 kDa in the liver cytosolic fraction.

Animals↗

Cerebrospinal fluid selenium and chromium levels in patients with Parkinson's disease.

We compared CSF and serum levels of selenium and chromium, measured by atomic absorption spectrophotometry, in 28 patients with Parkinson's disease (PD) and 43 matched controls. The CSF and serum levels of these trace metals did not differ significantly between PD patients and controls. CSF selenium and chromium levels were not correlated with age, age at onset, duration of the disease, scores of the Unified Parkinson Disease Rating Scale of the Hoehn and Yahr staging in the PD group. Although antiparkinsonian therapy did not influence significantly the CSF levels of selenium, PD patients not treated with levodopa had significantly higher CSF selenium levels than controls (p < 0.01). It is possible that increased CSF selenium levels could indicate an attempt of protection against oxidative stress. The normality of CSF and serum chromium levels suggest that these values are not related with the risk for PD.

Aged↗

Ultrastructural damage in chromium picolinate-treated cells: a TEM study. Transmission electron microscopy.

Chromium picolinate (CrPic) is a human dietary supplement that provides a bioavailable form of chromium(III). Its mechanism of action is unknown, and a number of toxic endpoints have been attributed to its use. Understanding the cellular effects of CrPic is important for confirmation or dismissal of these potential toxic effects. The purpose of this work was to characterize morphological damage caused by CrPic, picolinic acid, and chromic chloride in Chinese hamster ovary AA8 cells. A 48-h exposure to 80 micro g/cm(2) CrPic (0.44 mg/mL CrPic) produced 45% survival by colony formation. Transmission electron microscopy (TEM) showed 83% of analyzed cells having swollen mitochondria with degraded cristae. Apoptosis was identified by nuclear convolution and fragmentation, and cytoplasmic blebbing. Apoptosis was quantified by fluorescence microscopy with acridine orange/ethidium bromide staining. At the 80 micro g/cm(2) dose of CrPic, 37% of the cells were apoptotic cells at 48 h. An equivalent dose of picolinate, 3 mM, was much more cytotoxic and thus there was an inadequate cell number for TEM analysis. However, a lower dose of 1.5 mM induced 49% cell survival, and damaged 86% of the mitochondria, with 51% of the cells undergoing apoptosis. A dose of 1 mM chromic chloride produced 71% cell survival, and damaged 86% of the mitochondria, with 22% of the cells undergoing apoptosis. The amount of apoptosis correlated with overall cell survival by colony formation, but not with the amount of mitochondrial damage. The coordination of Cr(III) by picolinate ligands may alter the cellular chemistry of Cr(III) to make chromium picolinate a toxic form of Cr(III).

Animals↗

The time-dependent transport of chromium in adult rats from the bloodstream to the urine.

While chromium was proposed to be an essential trace element over 40 years ago and if essential should possess a specific transport and distribution mechanism, the details of its transport from the bloodstream to the urine have not been elucidated. However, chromium is known to be maintained in the bloodstream bound to transferrin and to be excreted in the urine bound to the oligopeptide chromodulin or a similar chromodulin-like species. Injection of (51)Cr-labeled transferrin into the bloodstream resulted in a rapid and insulin-sensitive movement of chromium into the tissues as Cr transferrin; greater than 50% of the Cr is transported to the tissues within 30 min. Tissue levels of Cr are maximal 30 min after injection; decreases in tissue Cr with time are mirrored by increases in urine Cr. Approximately 50% of the (51)Cr appears in the urine within 360 min of injection in the absence of added insulin; insulin treatment concurrent with injection of (51)Cr-labeled transferrin results in approximately 80% of the label appearing in the urine within 180 min. The removal of (51)Cr from the blood is faster than the appearance of (51)Cr in the urine; the lag in time indicates that the Cr transferrin in the blood and Cr in the urine are not in direct equilibrium and that intermediates in the transport of Cr must be involved. This establishes a clear pathway of transport of Cr starting from transport by transferrin from the bloodstream into the tissues, followed by release and processing in the tissues to form chromodulin, excretion into the bloodstream, rapid clearance of chromodulin or a similar species into the urine, and ultimately excretion as this species. Insulin stimulates the processing of Cr in the tissues.

Animals↗

Evaluation of biosorption potency of Acinetobacter sp. for removal of hexavalent chromium from tannery effluent.

Two bacterial consortia were developed by continuous enrichment of microbial population of tannery and pulp and paper mill effluent contained Serratia mercascens, Pseudomonas fluorescence, Escherichia coli, Pseudomonas aeruginosa and Acinetobacter sp. identified by 16S rDNA method. The consortia evaluated for removal of chromate [(Cr(VI)] in shake flask culture indicated pulp and paper mill consortium had more potential for removal of chromate. Acinetobacter sp. isolated from pulp and paper mill consortium removed higher amount of chromate [Cr(VI)] under aerobic conditions. Parameters optimized in different carbon, nitrogen sources, and pH, indicated maximum removal of chromate in sodium acetate (0.2%), sodium nitrate (0.1%) and pH 7 by Acinetobacter sp. Bacteria was applied in 2-l bioreactor significantly removed chromate after 3 days. The results of the study indicated removal of more than 75% chromium by Acinetobacter sp. determined by diphenylcarbazide colorimetric assay and atomic absorption spectrophotometer after 7 days. Study of microbial [Cr(VI)] removal and identification of reduction intermediates has been hindered by the lack of analytical techniques. Therefore, removal of chromium was further substantiated by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) which indicated bioaccumulation of chromium in the bacterial cells.

Acinetobacter↗

Serum chromium in patients with recent and old myocardial infarction.

The serum chromium in 45 subjects with no clinical evidence of ischemic heart disease was found to be 1.71 parts per billion (ppb) (S.E. +/- 0.14). In 34 patients with a previously documented myocardial infarction, it was 1.84 ppb (S.E. +/- 0.18). The difference was not significant nor was there any difference with age or sex. In 37 patients with acute myocardial infarction the serum chromium level rose to a mean of 6.36 ppb (S.E. +/- 0.51; p less than 0.001) during the first five days following the infarct, returning to normal over the next five days. There was no correlation between the serum chromium and blood glucose levels in these patients or in a further 14 patients who were receiving glucose infusions (chest pain without electrocardiographic or enzyme changes) or who were diabetics.

Adult↗

Radiochromium (chromium-51) evaluation of gastrointestinal blood loss associated with placebo, aspirin, and nabumetone.

Gastrointestinal blood loss is one of the most serious clinical events induced by drugs. To date, almost no nonsteroidal anti-inflammatory drug has been shown to be devoid of that side effect in a strictly controlled study. The objective of this study was to assess quantitatively, by use of radioactive chromium (chromium-51)-labeled red blood cells, gastrointestinal blood loss associated with nabumetone (1,000 mg daily), aspirin (3.6 g daily), and placebo. A total of 37 normal subjects, divided among the three treatment groups and a fourth group that received no treatment, were assessed clinically and quantitatively for gastrointestinal blood loss over a period of 28 days of "active" treatment. The results with chromium-51, analyzed on a logarithmic scale, revealed no statistically significant differences between the nabumetone, placebo, and control groups. Gastrointestinal blood loss in the aspirin group, however, was elevated when compared with all other groups at a high level of statistical significance (p less than 0.001). It is concluded that, under conditions in which aspirin causes substantial gastrointestinal microbleeding, nabumetone is not significantly different from placebo.

Adult↗

Analysis of chromium-51 release assay data using personal computer spreadsheet software.

The Chromium-51 release assay is a widely used technique to assess the lysis of labeled target cells in vitro. We have developed a simple technique to analyze data from Chromium-51 release assays using the widely available LOTUS 1-2-3 spreadsheet software. This package calculates percentage specific cytotoxicity and lytic units by linear regression. It uses all data points to compute the linear regression and can determine if there is a statistically significant difference between two lysis curves. The system is simple to use and easily modified, since its implementation requires neither knowledge of computer programming nor custom designed software. This package can help save considerable time when analyzing data from Chromium-51 release assays.

Chromium Radioisotopes↗