Monique Simonoff

A low plasma selenium is a risk factor for peripartum cardiomyopathy. A comparative study in Sahelian Africa

A specific selenium deficiency is a risk factor for Keshan disease, an endemic cardiomyopathy observed in China. In a Sahelian area of Niger, plasma selenium concentration was measured by neutronic activation and particle induced X-ray emission in 35 black African women with peripartum cardiomyopathy and 36 breast-feeding women without cardiac failure as controls. The plasma selenium concentration in patients was lower (48 +/- 25 ng/ml, mean +/- standard deviation) than in controls (77 +/- 16 ng/ml) (P less than 0.0001). Moreover, 40% (14/35) patients with peripartum cardiomyopathy had very low plasma selenium concentrations, below 45 ng/ml, versus none in controls. A low plasma selenium concentration is a risk factor for the Sahelian peripartum cardiomyopathy.

Low plasma Chromium in patients with coronary artery and heart diseases

Plasma chromium concentrations have been determined for 150 patients. These were subjected to coronary artery cineangiography and thereby divided into three groups: group CAD (those with coronary artery disease), group HD (those with heart disease, but no CAD) and group N (those with no CAD and no HD). Weighted, average chromium levels for these groups were 1.05, 1.72, and 8.51 ng/mL, respectively. The distributions of plasma chromium levels for the three groups suggest that an upper limit for plasma chromium may be established (6 ng/mL in this work) beyond which CAD may be considered to be extremely unlikely, thus eliminating the need for a certain number of cineangiographic examinations.

Fatty acids and plasma antioxidants in HIV-positive patients: Correlation with nutritional and immunological status

OBJECTIVE To investigate red blood cell (RBC) and plasma fatty acids (FA) in HIV-positive patients in relation to oxidative stress and nutritional or immunological status. DESIGN AND METHODS FA, plasma selenium, vitamins A and E were measured in 95 patients divided into four groups according to CD4 cells. RESULTS Poly- and di-unsaturated FA (PUFA, DUFA) decreased and saturated FA (SFA) increased in RBC in the patients below 400/mm3 and in plasma in the patients below 50/mm3. RBC SFA correlated to CD4 cells, PUFA to MDA. Unlike vitamin E, plasma vitamin A and selenium decreased in most groups. Plasma SFA and MUFA correlated negatively to selenium and PUFA and DUFA to vitamin E. No correlation was found between PUFA and nutritional markers. CONCLUSION FA seem to be modified during HIV infection by oxidative stress and disease evolution, but not by denutrition.

Reduction of pertechnetate by haloalkaliphilic strains of Halomonas.

Abstract It is shown for the first time that haloalkaliphilic bacteria, isolated from soda-lake environments were capable of reducing Tc(VII)O(4) (-) to the Tc(V), Tc(IV) and Tc(III) at pH 10 in carbonate medium, whereas no reduction took place without bacteria or in the presence of dead biomass. After 34 h of incubation, 55% remained as Tc(VII), 36% was found as Tc(IV) and 8% as Tc(V) and after 2 months 80% of the technetium was reduced. Technetium has a toxic effect on bacteria. Reduction of TcO(4) (-) was drastically decreased at concentration above 1.5 mM. The microbial reduction has been suggested as a potential mechanism for the removal of Tc from contaminated environments or waste streams.

The isolation of glucose tolerance factors from brewer's yeast and their relation to chromium

A new dietary factor, the glucose tolerance factor (GTF), was reported in 1957 that improved impaired glucose tolerance in rats. Most studies on GTF have used brewers yeast as the starting material, and it has been postulated that the active material is a low-mol wt organic complex containing Cr3+.It seemed thus important to isolate an active GTF from chromium-rich yeast (228 ppm Cr) obtained by incubation with chromium and to compare each fraction with corresponding ones from untreated yeast (0.48 ppm Cr). We developed an isolation and purification procedure by fractionation of yeast extract on an anion and cation exchange resin, and tested the GTF activity (glucose oxidation) on rat adipocytes. PIXE (proton-induced X-ray emission) was used to measure the chromium content of the individual fraction. Individual fractions with GTF activity did not differ between Cr-rich and Cr-deficient yeast, and there was no relationship between Cr content and GTF activity. This does not support the hypothesis that chromium is an obligatory constituent of the GTF, assuming that GTF is a unique substance.

Selenium in foods in France

Abstract The selenium levels in various samples of French meats, fish, vegetables, fruits, and other foodstuffs have been measured using a proton-induced X-ray emission (PIXE) method. Averaged levels found in France are low compared to those reported in the United States, but are comparable to those found in other European countries.

PIXE microanalysis in human cells: physiology and pharmacology

Abstract The micro-PIXE technique has been regularly carried out for more than two years to provide elemental distributions in human cells. Using this technique in the framework of cellular biology, two research axes have been developed: the cellular pharmacology f chemotherapeutic agents and the physiology of ionic cellular exchanges. These studies are based upon in vitro experimental models of human cells, either under the form of isolated cultured cells or as part of well-structured tissues. The aim of this paper is to present the experimental procedures and methodological aspects of cellular and subcellular quantitative mapping. Cell processing, identification of intracellular structures, quantitatives results and beam damage will be discussed and illustrated by examples issuing from the above-mentioned studies.

Nutritional status and plasma trace elements in peripartum cardiomyopathy. A comparative study in Niger.

Background Peripartum cardiomyopathy is a frequent condition of unknown origin in Sahelian West Africa. Objective To identify the nutritional and trace-elements status, plasma concentrations of albumin, pre-albumin (trans-thyretin), retinol binding protein, copper, selenium and zinc were assayed in 35 African women living in a Sahelian area, hospitalized in the Hôpital national, Niamey (Republic of Niger) with peripartum cardiac failure due to peripartum cardiomyopathy. Methods Plasma albumin was assayed by an automatic method; pre-albumin and retinol binding protein by radial immunodiffusion (Mancinis method); and plasma copper, selenium and zinc by neutron activation and particle-induced X-ray emission. The results were compared with those for a control group of African women living under the same conditions but without peripartum cardiac failure. Results Plasma albumin and pre-albumin were lower in patients with peripartum cardiomyopathy than they were in controls (P < 0.001). For retinol binding protein, the difference was not statistically significant. The plasma concentrations of selenium and zinc were lower in patients than they were in controls (48 ± 25 versus 77 ± 16 ng/ml and 0.90 ± 0.21 versus 1.17 ± 0.25μg/ml, respectively, P < 0.001) whereas that of copper was higher (2.03 ± 0.37 versus 1.23 ± 0.20 μ/ml, P < 0.001). The mean zinc:copper ratio was lower in patients than it was in controls (0.44 versus 0.95). Conclusion Such differences may be aetiological factors or biological consequences of the peripartum cardiac failure due to cardiomyopathy. Nutritional abnormalities may play a role in the pathophysiology of the disease.

High sensitivity PIXE determination of selenium in food and biological samples using a preconcentration technique

Abstract We have developed a very sensitive method to measure the selenium content in biological materials and different foods using PIXE after chemical preconcentration in the presence of tellurium. The preconcentration yield is determined using radioactive selenium, and yttrium is added as an internal standard.

Iron in hereditary retinal degeneration: PIXE microanalysis: Preliminary results

Abstract Several types of hereditary retinal degeneration with progressive alteration of photoreceptors exist in men and animals. Recent immunohistochemical results have shown strong degradation of transferrin, the protein responsible for iron transport, in retinas of rats with hereditary retinal degeneration. Freeze-dried thin sections of rat retinas from different stages of the disease, and respective coeval control sections, have been analyzed using nuclear microprobe. In this first part of the study, the rat retinas at post-natal stages of 35 and 45 days have been analyzed. The sample preparation and the post-irradiation staining to determine precisely the retinal layers involved are described. Preliminary results of element distributions (K, Ca, Fe) in the rat retina layers are discussed. A very high content of calcium in the choriocapillaris of dystrophic rat retinas was observed. Preliminary results on iron distribution in the rat retina layers are presented.