Low selenium status in alcoholic cirrhosis is correlated with aminopyrine breath test. Preliminary effects of selenium supplementation.

The relationship among impaired selenium status, lipid peroxidation, and liver function was examined in 19 hospitalized patients with severe alcoholic cirrhosis. Plasma selenium was found to be significantly lower (mean +/- SD: 54 +/- 13 micrograms/L) than in healthy controls (83 +/- 11 micrograms/L) and plasma malondialdehyde, assessed as thiobarbituric acid reactants, which reflects lipid peroxidation, was increased (2.0 +/- 1.

Lipid peroxidation assessed by serum thiobarbituric acid reactive substances in healthy subjects and in patients with pathologies known to affect trace element status.

Serum thiobarbituric acid reactive substances (TBARS), Zn, Cu, and Se concentrations were determined in 47 healthy adults and in patients with diseases, such as renal insufficiency, insulin-dependent diabetes mellitus, chronic pancreatitis, liver cirrhosis, or cancer, in order to clarify the relationship between this indicator of lipid peroxidation and antioxidative trace element status. TBARS levels were higher than control values in all pathological cases, except in cancer patients. Cu levels in patients highly correlated with ferroxidase ceruloplasmin activity (r = 0.

Precision and accuracy of in vivo bone mineral measurement in rats using dual-energy X-ray absorptiometry.

The aim of this study was to evaluate the precision and accuracy of dual-energy X-ray absorptiometry (DXA) for measuring bone mineral content at different sites of the skeleton in rats. In vitro the reproducibility error was very small (< 1%), but in vivo the intra-observer variability ranged from 0.9% to 6.

Effects of zinc supplementation on the phagocytic functions of polymorphonuclears in patients with inflammatory rheumatic diseases.

The phagocytosis of blood polymorphonuclear cells (PMNs) was measured by cytofluorometry in 22 patients with inflammatory rheumatic diseases before and after a 60-day treatment with 45 mg zinc daily or a placebo, and the values were compared with those obtained in a group of healthy subjects. Plasma zinc was lower than controls before supplementation and phagocytosis assessed by the percentage of PMNs exhibiting phagocytic activity was significantly impaired. Zinc supplementation increased the percentage of phagocytic PMNs and the mean phagocytic activity, particularly in subjects with initial low phagocytosis.

Selenium and lipid parameters in plasma of Portuguese subjects.

To obtain further insight into the role of selenium in the development of atherosclerosis, plasma selenium and lipid parameters were determined in 126 Portuguese subjects living in the region of Lisbon, 60 women and 66 men, 20-60 years old, divided up in to three groups according to their plasma lipid profile: Group I consisted of normolipidemic subjects having plasma triglycerides and total cholesterol < 200mg/dL; Group II was composed of hypercholesteremic subjects with total cholesterol > 200mg/dL and plasma triglycerides < 200mg/dL; Group III was composed of hypercholesteremic and hypertriglyceremic subjects having total cholesterol and plasma triglycerides > 200mg/dL. Respective values for mean plasma selenium (+/- SD) in the groups were: 93 +/- 18 micrograms/L, 90 +/- 17 micrograms/L and 96 +/- 18 micrograms/L. A weak significant difference in plasma selenium between women and men was, however, observed in Group I (87 +/- 20 micrograms/L vs.

Optimized steps in fluorometric determination of thiobarbituric acid-reactive substances in serum: importance of extraction pH and influence of sample preservation and storage.

A simple, reliable, and reproducible fluorometric method for measuring thiobarbituric acid-reactive substances (TBARS) in serum is proposed, based on the reaction between malondialdehyde (MDA) and thiobarbituric acid. Formation of TBARS was complete at pH 2.4-2.

Plasma and liver selenium levels in the rat during supplementation with 0.5, 2, 6, and 15 ppm selenium in drinking water.

Plasma and liver selenium of Wistar rats were determined after 1, 3, and 6 mo supplementation with 0.5, 2, 6, or 15 ppm selenium as sodium selenite in drinking water. Plasma selenium was not different from control values at additional intake of 0.

Zinc distribution in blood components, inflammatory status, and clinical indexes of disease activity during zinc supplementation in inflammatory rheumatic diseases.

The effects of zinc supplementation on zinc status and on clinical and biological indicators of inflammation were investigated in 18 patients with chronic inflammatory rheumatic diseases and in 9 healthy control subjects. Patients with mild and recent onset disease were assigned to a 60-d trial to receive either 45 mg Zn (as gluconate)/d or a placebo, while control subjects received the zinc supplement. Baseline mean plasma zinc of the patients was low whereas mononuclear cell zinc content was elevated, suggesting a redistribution of the element related to the inflammatory process rather than to a zinc-deficient state.

[Some factors influencing the bioavailability of zinc in oral pharmaceutical dosage forms].

Absorption and distribution of zinc in 6 dosage forms were determined in 10 subjects by performing a pharmacokinetic study of the serum zinc profile after oral administration of a dose corresponding to 45 mg elemental zinc. The aim of this study was to document the influence on zinc bioavailability of factors such as the chemical form of zinc, the pharmaceutical form, and the division of the administered dose. The pharmacokinetic parameters indicate for gelatin capsules without excipients taken in a non divided dose better performances for zinc gluconate in comparison to zinc sulfate.

Effects of acute prednisolone administration on plasma and liver copper in rats with adjuvant arthritis.

Several studies in animals and humans have shown that copper metabolism could be affected by inflammation or by corticosteroids. The relative importance of these two factors, often imbedded in clinical practice, was assessed by investigating the effects of acute prednisolone administration (30 mg/kg, ip) on healthy and adjuvant arthritis rats. Plasma copper levels were significantly higher in arthritic rats compared to healthy animals, whereas there was a slight, but nonsignificant increase in liver copper.

Absorption and metabolism of oral zinc gluconate in humans in fasting state, during, and after a meal.

The absorption and metabolism of zinc in a commercial form for oral use (Rubozinc, 15 mg zinc as gluconate) were investigated in 10 subjects by a kinetic study of the serum zinc profile after administration of 45 mg zinc under three conditions: after an overnight fast, during a standardized breakfast, and 2 h after this meal. The pharmacokinetic parameters were calculated by a method suitable to the characterization of rebound effects (recycling of the element in the gastrointestinal tract). In fasting state, the parameters were comparable to those previously collected in the same subjects with oral 45 mg zinc as sulfate, except with very significantly higher Cmax and area under curve (AUC), showing a better bioavailability for zinc in the commercial form.

Clinical implications of trace elements in endocrinology.

The implications of essential trace elements in endocrinological processes, mainly thyroid function, growth, gonadal function, adrenal hormones, prolactin, glucose homeostasis, calcium-phosphorus metabolism, and thymulin activity, are reviewed. Most concerned elements in this field include iodine, zinc, selenium, copper, chromium, manganese and vanadium. The minerals are powerful modulators of several physiological functions that can be considerably perturbed in deficiency states.

The Visual Advice Centre, Eindhoven, The Netherlands. An intervenient evaluation.

On referral by ophthalmologists, the Visual Advice Centre provides the partially sighted with advice and prescriptions for illumination and visual aids. In this paper the multidisciplinary structure of the centre is presented and the results obtained in the first 18 months of its existence are discussed. Two hundred and ninety-eight patients were referred to the centre in this period.

Interest of zinc determination in leucocyte fractions for the assessment of marginal zinc status.

In order to test the sensitivity of leucocyte zinc determination in the assessment of zinc status, an isolation procedure of mononuclear (MNC) and polymorphonuclear (PMNC) cell fractions was developed. Zinc concentrations in cells from healthy subjects were (mean +/- SD, in mumol/10(10) cells): 0.81 +/- 0.

Pharmacokinetic study of orally administered zinc in humans: evidence for an enteral recirculation.

Starting from the experimental design of the established 'Zinc Tolerance Tests', the absorption and distribution of the essential trace element zinc in humans was investigated in 10 subjects by performing a pharmacokinetic study of the serum zinc profile after oral administration of a pharmacological dose of the metal, i.e. 0.

Effects of acute and chronic prednisolone treatment on serum zinc levels in rats with adjuvant arthritis.

Several studies in animals and humans have independently demonstrated that zinc metabolism is significantly affected either by inflammation or by glucocorticoid administration. The relative importance of these two factors was assessed in this study by the investigation of the effects on serum zinc concentrations of acute and chronic prednisolone treatments in adjuvant arthritis rats and in healthy controls animals. Acute steroid administration (3 mg/kg, i.

[The nutritional importance and pharmacologic effects of cobalt and vitamin B 12 in man].

Cobalt is an unique trace element for man as it can only reveal its essential properties if provided directly as its biological active form, cobalamin or vitamin B12, the daily requirement of which is 1 to 2 micrograms in adults. This vitamin takes part in the activity of the enzyme methylmalonyl coenzyme A mutase, involved in the conversion of propionyl CoA to succinyl CoA, an intermediary product of the citrate cycle, and of the 5-methyltetrahydrofolate: homocystein methyltransferase, working in the metabolism of methionin and in DNA synthesis. Vitamin B12 deficiency is responsible for a megaloblastic anemia called pernicious anemia and for specific neurological disorders that can be corrected by adequate supplementation.

Factors affecting determinations of manganese in serum by atomic absorption spectrometry.

A method was developed for the routine determination of manganese in serum from healthy human subjects by graphite furnace atomic absorption spectrometry. We controlled the experimental conditions rigorously, from sampling to analysis, to minimize contamination and to conserve diluted samples. We optimized the procedure with two serum Reference Materials, one of which had a manganese concentration very close to what is thought to be the physiological concentration in humans.

Lymphocyte response is enhanced by supplementation of elderly subjects with selenium-enriched yeast.

The effect of selenium supplementation on plasma selenium concentrations and lymphocyte-proliferation responses to mitogens was investigated in 22 elderly institutionalized subjects. Subjects were assigned to a 6-mo trial with either 100 micrograms Se/d (as selenium-enriched yeast) or a placebo. Plasma selenium concentrations of the selenium-supplemented group increased from 0.

Effects of selenium supplementation on immune parameters in gut failure patients on home parenteral nutrition.

The relationships between some parameters of the immune response and selenium were investigated in five patients receiving home parenteral nutrition for short-bowel syndrome. They were first submitted to a relative depletion by providing 20 micrograms selenium/day as L-selenomethionine for 1 mo. Then, daily selenium intake was raised to 200 micrograms for 2-4 mo.

[The nutritional importance and physiopathology of molybdenum in man].

Molybdenum is an essential trace element taking part in the active site of three human enzymes: xanthine oxidase, aldehyde oxidase and sulfite oxidase, playing a role in the detoxification of the organism and/or the production of important intermediary products. The perturbation of the first two enzymes has no established clinical consequence, but a decrease in activity of the third one is harmful for the organism, particularly the nervous system during pre- or post-natal development. The anomalies in the function of these enzymes are generally inherited and linked to the impaired production of the molybdenum cofactor, an organic molecule complexed to the element in the active site.

Selenium in rheumatic diseases.

Selenium is involved in several important biochemical pathways relevant to rheumatic diseases. Experimental and clinical studies suggest that selenium modulates the inflammatory and immune responses. Patients suffering from inflammatory rheumatic diseases often have low selenium levels, but this finding does not correlate with disease severity.

Methods in determination of selenium states.

Selenium status in man has been assessed either by determination of the selenium concentration in biological materials or by the measurement of biochemical or clinical selenium-dependent functions. Over and above the discussion of normal levels and of the numerous factors liable to influence the above mentioned indices, the present review more specifically deals with the sensitivity of various parameters to changing selenium status, both in deficiency states and in over-exposure to the element, and the attempt is made to establish the specificity of these indicators in the diagnosis of selenium states. The possibilities for defining "adequate" or "optimum" selenium concentrations are also examined.