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Serum vanadium levels have been measured by neutron activation analysis. They are higher (3.10 +/- 1.38 ng/mL) in patients suffering depressive illness than in normal subjects (0.67 +/- 0.32 ng/mL).

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 ability of bacteria to reduce pertechnetate in alkaline conditions was investigated using halophilic bacteria isolated from soda-lakes environments. Anaerobic halophilic bacteria were able to reduce as much as 0.25 mM pertechnetate, whereas no reduction took place without bacteria or in the presence of heat-killed bacteria. The results obtained showed reduction of Tc(VII)O4 − to the Tc(V) and Tc(IV) at pH 10 in the carbonate-bicarbonate medium. About 57% of the total technetium was determined to be Tc(IV), 1–3% as a Tc(V) and 17–20% as a Tc(VII) after 1–3 days of incubation with bacteria. The microbial reduction of Tc(VII) in alkaline conditions has been suggested as a potential mechanism for the removal of Tc from contaminated environments or waste streams.

A high resolution inductively coupled plasma mass spectrometric (HR-ICP-MS) method for the determination of plutonium isotopes, Am and the 240Pu/239Pu isotope ratio utilising modification of Pu-02-RC Plutonium in Soil Samples, Pu-03-RC Plutonium in Soil Residue—Total Dissolution Method, Pu-11-RC Plutonium Purification—Ion Exchange Technique, Pu-12-RC Plutonium and/or Americium in Soil or Sediments, HASL-300 was developed. Total plutonium concentrations (239+240Pu) measured in environmental samples by this HR-ICP-MS method were in good agreement with recommended data obtained from a-spectrometry. It was achieved the decreasing of the time to analyze the samples over than 33%.

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.

The effect of extracellular adhesion factors, and of distinct culture substrata, on trace element content of epithelial cancer cells was investigated using nuclear microprobe analysis. Essential trace metal concentrations in human carcinoma cells cultured either onto tissue culture plastic dishes, onto microanalysis supports made of thin Formvar surfaces coated or not with gelatin gel, or onto polycarbonate films, were compared. Abnormally high copper concentrations were noticed specifically in cisplatin-resistant epithelial cancer cells cultured onto Formvar or polycarbonate surfaces with or without reconstituted extracellular matrix. Manganese, iron and zinc concentrations remained unchanged in these cells. These results indicate that (1) metal uptake of cells cultured onto substrata used for X-ray microanalysis can be different to that of cells cultured onto usual plastic dishes, (2) cisplatin-resistant epithelial cancer cells specifically accumulate copper when cultured onto thin Formvar or polycarbonate films, and could be used as in vitro models for copper overload studies.

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 Hopital 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 (Mancini's 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 +/- 0.25 micrograms/ml, respectively, P < 0.001) whereas that of copper was higher (2.03 +/- 0.37 versus 1.23 +/- 0.20 micrograms/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.

To investigate the effects of selenium or beta-carotene supplementation in human immunodeficiency virus (HIV)-infected patients, who are known to have deficiencies of selenium and vitamin A, we evaluated the blood enzymatic antioxidant system, including superoxide dismutase (SOD), selenodependent glutathione peroxidase (GPX), and catalase (Cat); glutathione (GSH) status; and plasma selenium concentration. The placebo group consisted of 18 HIV-infected patients with no supplementation, the selenium group was composed of 14 patients receiving oral selenium treatment, and the beta-carotene group comprised 13 patients receiving oral beta-carotene supplementation. All groups were studied for 1 y. At the beginning of the study, a significantly higher SOD activity (P < 0.001) was observed in all HIV-infected patients compared with uninfected control subjects, and GPX activity at baseline was higher in the placebo (P < 0.004) and selenium (P < 0.014) groups than in the control subjects. These higher enzyme activities could be related to an increased synthesis of these enzymes in erythrocyte precursors under oxidative stress. Moreover, we observed significantly lower GSH values in all HIV-infected patients than in control subjects at the beginning of the study (P < 0.001). After selenium or beta-carotene supplementation, no significant difference was observed for SOD activity compared with baseline. On the contrary, GPX activity increased significantly after selenium treatment (P < 0.04 between 3 and 6 mo), whereas a slight increase was found after beta-carotene treatment. Similarly, a significant increase in GSH values was observed at 12 mo compared with baseline both after selenium supplementation (P < 0.001) and beta-carotene supplementation (P < 0.01). Because GPX and GSH play an important role in the natural enzymatic defense system in detoxifying hydrogen peroxide in water, selenium supplementation could be of great interest in protecting cells against oxidative stress. The lower efficiency of beta-carotene could be attributed to the seriousness of the pathology at the time of recruitment into the beta-carotene group.

Macro-and Micro-PIXE analysis were applied to study the mechanisms of cellular resistance to cisplatin, a chemotherapeutic agent, widely used nowadays for the treatment of ovarian cancer. Two cultured cell lines, a cisplatin-sensitive and a resistant one, were compared for their trace elements content and platinum accumulation following in vitro exposure to the drug. Bulk analysis revealed significant differences in copper and iron content between the two lines. Subsequent individual cell microanalysis permitted us to characterize the response of the different morphological cell types of the resistant line. This study showed that the metabolism of some trace metals in cisplatin-resistant cells could be affected but the exact relationship with the resistant phenotype remains to be determined. From a technical point of view, this experiment demonstrated that an accurate measurement of trace elements could be derived from nuclear microprobe analysis of individual cell.

The effect of taurine on the Na(+), K(+), Cl(-) concentration and distribution in epithelial and compact layers of the human amniotic membrane had been investigated using the Bordeaux nuclear microprobe. Particle induced X-ray emission and Rutherford backscattering spectrometry techniques had been used to provice quantitative measurements. In physiological medium, the monovalent ions concentrations were identical in epithelial and compact layers. The addition of taurine in Hanks' physiological fluid had no effect on Na(+) concentration, but decreased K(+) and Cl(-) concentration in both layers. The quantitative results were related to electrophysiological observations on the effect of taurine on ionic exchanges through channels and paracellular pathways.

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 brewer's 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.

The sorption of selenite ions onto Fe3O4 and Fe/Fe3C nanoparticles (NPs) was studied in aqueous solutions under anoxic conditions using gamma spectrometry and X-ray absorption spectrometry (XAS) techniques. This is the first study related to the remedial applications of Fe/Fe3C NPs. FesO4 NPs have been prepared by conventional coprecipitation of Fe(II) and Fe(III) in basic solutions. Stable Fe/Fe3C NPs have been prepared by Fe(CO)5 sonicating in diphenylmethane solutions and subsequently annealing the as-prepared product. Kinetic study demonstrated that Se(IV) sorption is extremely rapid: the equilibrium is reached in approximately 10 and 30 min for Fe3O4 and Fe/Fe3C NPs, respectively, at pH = 4.9-5.1 in solutions of 0.1 M NaCl. The distribution coefficients are also very high for both kinds of NPs (Kd3000). Increasing the pH to 10.3 or adsorption of organic ligands, like L-lysine or dodecanoate, at the surface of NPs causes the decrease in Kd values. However, even in these cases Kd values exceed 150. Magnetic NPs loaded with selenium can be easily and completely removed from solution with a 0.4 T permanent magnet. XAS study revealed the absence of Se(IV) reduction during the sorption onto Fe3O4 NPs in the pH range of 4.8-8.0. By contrast, the removal of Se(IV) with Fe/Fe3C NPs in anaerobic conditions occurs via Se(IV) reduction to Se(-II) and subsequent formation of iron selenide at the particle surface. Thus, the Fe/Fe3C NPs are superior to Fe3O4 NPs due to their ability to immobilize rapidly and irreversibly Se(IV) via reductive mechanism. Presumably these particles could be also effective for the removal of other contaminants such as hexavalent chromium, actinides, technetium, and toxic organic compounds.

Recently published results of the cooperative studies executed by the Institute of Physical Chemistry and Electrochemistry of Russian Academy of Sciences (IPCE RAS), Research Center Vallée du Rhone (CEA, France), Institute of Nuclear Physics Orsay and University Bordeaux I [Centre Nationale de Recherches Scientifiques (CNRS), France] are reviewed. The review includes data obtained for the first time on the electrochemical properties and anodic dissolution of uranium monocarbide considered among possible bases of the fuel for the reactors of the IVth generation. The results of the investigations in the field of the synthesis of tetraalkyl ammonium pertechnetates, their physicochemical properties and thermal decomposition with formation of Tc metal and Tc monocarbide are summarized. The electrochemical reactions with participation of Tc ions in various oxidation states and their application in the nuclear fuel cycle are described. The behavior of technetium in natural waters near the locations of the radwastes long-term storage and in the areas surrounding nuclear power plants in RF and France was studied.

The sorption of technetium by powdered and polished mineral stibnite Sb2S3 has been investigated in simulated and natural underground waters from the Meuse/Haute–Marne region (France). The sorption by powdered stibnite has been found to be complete under both aerobic and anaerobic conditions in batch experiments. The sorption rate is higher in the absence of oxygen than under aerobic condition. Increasing the temperature from 30 °C to 60 °C results in a rise of the sorption rate by 9.1 and 27 times under anaerobic and aerobic conditions, respectively. The observed differences in sorption kinetics in the presence and in absence of oxygen are explained by the interaction of oxygen with sulfide ion in aerobic conditions and by the reduction of technetium(VII) by iron(II) and by other impurities present in natural water and in the mineral, and by the subsequent sorption of Tc(IV) on stibnite under anaerobic conditions. The sorption on a polished mineral surface resulted in the formation of a technetium film, probably Tc2S7, with a thickness of 1−3 μg Tc/cm2 at pH 3−6 and 4−12 μg Tc/cm2 at 9−12. The simultaneous formation of stibnite colloids with adsorbed technetium occurs at pH 9−12. The study of the technetium film on the mineral by proton induced X-ray emission analysis showed it to be at least one order of magnitude thinner on the SiO2 impurities than on the main Sb2S3 component and the iron impurities.

Leaves of plants have the ability to accumulate the long-lived fission product (99)Tc. In the present work, an attempt was made to separate and characterize technetium species formed in maize grown on soil contaminated with Tc(VII)O(4)(-) solution. Data obtained from selective extraction, a Phosphorimager and liquid scintillation were employed.

In this study, we performed nuclear microprobe analysis on cultured human ovarian cancer cells exposed to pharmacological concentrations of 4′-iodo-4′-deoxydoxorubicin (IDX), an anthracycline anticancer drug. We observed that iodine and iron cellular distributions were strongly correlated, suggesting intracellular iron chelation by the anthracycline. The average cellular iron concentration did not change during drug exposure, but the cellular distribution of iron was modified following the preferential nuclear localization of iodine, as determined by single cell microanalysis. These results are important for understanding the cellular pharmacology of anthracyclines. They suggest that iron cellular delocalization and its subsequent nuclear accumulation may participate to the overall cytotoxicity of IDX, and more generally to anthracycline antitumor activity.

Objective: To investigate red blood cell (RBC) and plasma fatty acids (FA) in HIV-positive patients in relation to oxidative stress and nutritional or immunologiical 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.

Plasma antioxidant status can be evaluated by selenium, retinol and a-tocopherol. The present study concerns 89 HIV-1 positive patients. The plasma level of selenium was determined by PIXE (proton-induced X-ray emission analysis) and by measurement of levels of vitamins A and E by HPLC. The data were compared to controls; among the HIV-1 patients, significant differences were found for plasma selenium between groups selected on the basis of the CD4 lymphocyte count. Differences were also observed for plasma retinol between the HIV-1 patients and the control subjects. Correlations with other nutritional and immunological parameters were shown.

The effect of magnesium and taurine on the permeability of cell membranes to monovalent cations has been investigated using the Bordeaux nuclear microprobe. PIXE and RBS techniques have been used to provide quantitative measurements and ion distributions in the isolated amniotic membrane. This physiological model for cellular exchanges allowed us to reveal the distribution of most elements involved in cellular pathways and the modifications under different experimental conditions of incubation in physiological fluids. The PIXE microanalysis provided an original viewpoint on these mechanisms. Following this first study, the amnion compact lamina was found to play a role which was not, up to now, taken into account in the interpretation of electrophysiological experimentations. The release of some ionic species, such as K + , from the epithelial cells, during immersion in isotonic fluids, could have been hitherto underestimated.

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.

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.

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.

Proton induced X-ray emission (PIXE) analysis, following enrichment by APDC-MIBK extraction, is used to measure chromium concentration in blood plasma from patients submitted to selective coronary artery cineangiography. The yield of the chromium preconcentration is determined with carrier-free 51Cr. From the catheterism results the patients are classified into three populations: coronary artery disease (CAD), heart disease (HD) and normal arteries (N). The first two groups, CAD and HD, have significantly lower chromium concentrations than does the group with normally patent arteries. The present analytical method and the results obtained provide an interesting contribution to the difficult problem of chromium determination in biological media.

Vanadium concentrations have been measured in the serum of 23 healthy subjects by neutron activation analysis, with post-irradiation chemical separation. The values obtained fall in a fairly narrow range (260-1300 ng/L, mean 670 ng/L), which suggests a physiological role for this element. We checked the method by analysis of standard (U.S. National Bureau of Standards) water samples and serum samples supplemented with 48V, and we found excellent agreement with expected results in both cases. We consider the reported results for human serum to be more reliable than those obtained by atomic absorption spectroscopy.

The determination of calcium in erythrocytes by the method PIXE requires the preliminary elimination of large amounts of potassium. The best results, with regard to potassium removal and calcium yield, were obtained by carrying out a coprecipitation of calcium and strontium in 80% nitric acid. The development of the method has shown the importance of the total elimination of leucocytes and platelets from the serum in order to avoid erroneously high values for erythrocyte calcium.

The cross sections for production of 36Cl in targets of Fe, Ti and Ca, bombarded by protons of 0.15, 1.05 and 24 GeV, have been measured by radiochemical techniques. The ratio Cl/Fe in cosmic radiation has been calculated from these results, using the “leaky box” model, leading to the conclusion that 36Cl decay does occur.

Excitation functions of all stable or long-lived krypton isotopes were measured or estimated for incident protons and neutrons in Rb, Sr, Y, and Zr targets. Experimental data concern mostly Y and Zr targets bombarded with 0.059 to 24 GeV protons. The products /sup 78en-dash86/Kr, /sup 74/As, /sup 75/Se, /sup 83,84,86/Rb, /sup 85/Sr, /sup 88/Y, /sup 88,95/Zr, and /sup 92/Nb/sup m/ were measured using high-sensitivity mass spectrometry and nondestructive ..gamma.. counting. Lighter products such as /sup 38,39,42/Ar and 12 radioactive isotopes from /sup 7/Be to /sup 65/Zn were also measured in some cases and their cross sections are given in an appendix. Most excitation functions pass through a maximum between 0.4 and 0.8 GeV, and the peak energy could depend on the ..delta..A value. The results, combined with a general survey of nuclear reactions in Ga to Nb targets, permitted the development of new systematics leading to the calculation of spallation-produced Kr isotopes in the moon bombarded with galactic and solar cosmic rays. Compared to cosmogenic krypton measured in nine well-documented lunar samples, /sup 83/Kr is predicted with a precision better than 33% (1sigma) and the production ratios /sup i/Kr//sup 83/Kr are predicted to better than 25%. It is concluded thatmore » the cosmogenic ratios /sup 86/Kr//sup 83/Kr and /sup 81/Kr//sup 83/Kr are dependent on the main target element concentrations. This should be taken into account in strontium-rich samples when calculating exposure ages of extra-terrestrial materials.« less

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.

Depressive states are associated with various clinical or biochemical anomalies, some of which are considered to be signs or indicators ot depression (Extein et al. 1981: Harrison et al. 1984). Several studies have suggested that vanadium may play an important role in depresalve states by regulating the activny of the ubiquitous enzyme. Na-K-ATPasc. thereby directly affecting the activity of the membrane sodium pumps at either the peripheral level (Naylor and Smith 198 I) or the brain (Robinson 198 I ). The amount of work that has been carried out on the subject of vanadium and depressive illness has undoubtedly been limited by the major technical difficulties involved in the measurement of small concentrations of vanadium in bioloplcal media. as the values obtained are strongly dependent on the method employed. In this preliminary study. wc attempted to determine whether or not differences in serum vanadium levels could be detected in patients suffering from various forms of depression compared with normal subjects. The vanadium determinations were carried out at P. Siie Labo

Recent measurements have demonstrated that plasma chromium levels in patients with coronary artery disease are very much lower than in normal subjects. A review of the literature concerning the physiological functions of chromium (or GTF) shows it to be implicated in most of the known factors of cardiovascular risk, via its effect on insulin levels and activities. Chromium deficiency leads to impaired lipid and glucide metabolism and results in high circulating insulin levels, the probable consequences of which suggest that chromium deficiency may be a primary risk factor in cardiovascular disease.

We present the results of a 3 year study concerning serum vanadium measured by neutron activation analysis for 87 subjects from three populations (healthy controls, depressives, cirrhotics). We found depressives to have higher levels but no significant difference between cirrhotics and controls.

Since 1945 alloys of nickel-chromium have been widely used in Odontology thereby permitting the development of metallic dental implants.