Measurement of 14MeV neutron-induced prompt gamma-ray spectra from 15 elements found in cargo containers.

Within the EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) project, the gamma-ray spectra produced in a series of materials by 14-MeV tagged-neutron beams have been collected in the inspection portal equipped with large volume NaI(Tl) detectors, in order to build a database of signatures for various elements: C, N, O, Na, Al, Si, Cl, K, Ca, Cr, Fe, Ni, Cu, Zn, Pb. The measured spectra have been compared with prediction from Monte Carlo simulations to verify the consistency of the relevant nuclear data inputs. This library of measured 14-MeV neutron-induced gamma-ray spectra is currently used in a data processing algorithm to unfold the energy spectra of the transported goods into elementary contributions, thus allowing material identification.

Effects of exhaustive exercise and vitamin B6 deficiency on free radical oxidative process in male trained rats.

There is growing evidence that oxygen free radical production and subsequent lipid peroxidation are normal sequelae to the rise in oxygen consumption concomitant with exercise. In addition, increased lipid peroxidation has also been shown in vitamin B6-deficient rat plasma, liver, and kidney. To investigate the potential for a role of vitamin B6 in exercise-induced oxidative stress, 36 male Sprague-Dawley rats received 0 (n = 12), 2 (n = 12), and 8 mg pyridoxine (PN)-HCl/kg diet (n = 12) and were trained by a 9-week swimming program. After 9-weeks of training, six rats (exhausted: E rats) of each vitamin group were exercised to exhaustion by swimming while the other six rats rested (nonexhausted: NE rats). Ascorbate, ascorbate free radical and antilipoperoxidant capability (AC) were evaluated in plasma. These parameters were higher in E rats than in NE rats. Free radical-mediated lipid peroxidation was measured in tissue and plasma by evaluation of thiobarbituric acid reactive substances (TBARS) content. This index of peroxidation was significantly increased in liver of E rats but not in plasma, heart, and gastrocnemius muscle. Concentration of TBARS in liver was the highest in vitamin B6-deficient rats (consuming 0 mg PN-HCl/kg diet) and the lowest in vitamin B6-sufficient rats (consuming 8 mg PN-HCl/kg diet). Vitamin E (alpha-tocopherol) levels in liver and heart were negatively related to vitamin B6 levels in the diet. Independently of vitamin B6, liver and muscle alpha-tocopherol levels were significantly higher in E animals than in NE animals. There is good evidence according to our results that exercise induced an oxidative stress, as indicated by a significant increase of ascorbyl radical levels in the plasma. The effects of vitamin B6 deficiency on the free radical metabolism are low in trained rats. On the contrary, exhaustive exercise induced modifications in the metabolism pathways of vitamin C and E objectivated by variations of levels of vitamin C in the plasma and vitamin E in liver.

Computerized analysis of food records: role of coding and food composition database.

Reported dietary intake records of 30 subjects (26 men and 4 women) were analysed by three different centres using their own computerized nutrient database systems. The agreement between systems was evaluated by different statistical criteria (the correlation coefficient, the mean difference and the proportion of individuals placed in the same thirds of distribution). Significant differences between the three systems were found in the calculation of alcohol, polyunsaturated fatty acids, saturated fatty acids, linoleic acid, linolenic acid, cholesterol, magnesium, sodium and water. To ascertain the extent of mean differences that could be attributed to the coding process or to the database used, coding forms of each centre were forwarded to the other two centres. Analysis of variance showed that differences in the data obtained by the three systems were mainly due to the food composition database used.

Effect of prototypic polychlorinated biphenyls on hepatic and renal vitamin contents and on drug-metabolizing enzymes in rats fed diets containing low or high levels of retinyl palmitate.

Two groups of weanling male Sprague-Dawley rats fed a diet supplemented with either 0.6 or 6 retinol equivalents/g diet were each separated into three further groups receiving 300 mumol 2,2',4,4',5,5'-hexachlorobiphenyl/kg body weight, 300 mumol 3,3',4,4'-tetrachlorobiphenyl kg/body weight or vehicle only (corn oil). Only the coplanar (3,4)2Cl congener caused a slight reduction in food intake, thymic atrophy and led to a significant decrease in the liver vitamin A storage. The vitamin A lost by the liver was approximately the same in both dietary groups; however an increased renal accumulation of vitamin A was observed in the high vitamin A group. Serum retinol was reduced by (3,4)2Cl treatment but remained unchanged by (2,4,5)2Cl exposure. Total amounts of ascorbic acid and its oxidation products were increased in the liver and in the kidney by both xenobiotics while niacin and thiamine concentrations were lowered by (3,4)2Cl only. Microsomes from vitamin A-deficient rats exhibited a marked decrease in the anisotropy parameter. After (2,4,5)2Cl exposure, an increase in membrane fluidity was observed linked to a decrease in cholesterol/phospholipid (C/P) ratio. Treatment with (3,4)2Cl caused a significant decrease in the index of fluorescence polarization only in the low vitamin A group even if the C/P ratio was enhanced in both dietary groups. This study shows that the polychlorinated biphenyl with the 3-methylcholanthrene-type pattern of induction of cytochrome P-450 has more profound effects on B group vitamins and particularly vitamin A homeostasis than does the phenobarbital-type inducer. Moreover, this situation, which has been found to be similar to that in vitamin A deficiency, is not ameliorated by a high dietary vitamin A intake.

[Microbiological assay of pantothenic acid in rat liver using Tetrahymena]. / Dosage microbiologique de l'acide pantothénique dans le foie du rat avec Tetrahymena.

Microbiological Assay of Pantothenic Acid in Rat Liver using Tetrahymena. The quantitative determination of total pantothenic acid in rat liver using Tetrahymena was carried out in the same way as a microbiological assay. The strain selected was Tetrahymena thermophila grown on rat liver. Inoculum was obtained from a commercial medium. The assay medium consisted of a dry powder to be rehydrated and heated to boiling, and then adjusted to pH 7. Liver pantothenic acid was extracted by autolysis. Tetrahymena use made one accustomed to a biological reagent easy to manipulate but with complex nutritional requirements. Consequently the organism should be more extensively used for nutritional or toxicological studies.

[Liver concentrations of water-soluble vitamins in rats treated, alone or in combination, with potassium metabisulfite, tannic acid, and ethanol]. / Concentrations du foie en quelques vitamines hydrosolubles chez le rat recevant, isolément ou en association, du métabisulfite de potassium, de l'acide tannique et de l'éthanol.

Rats given tannic acid (3.2 p. 100 in diet) have lower biotin and total ascorbic acid liver contents (after 2 months), later they have higher vitamin B6 contents (after 6 months on the same diet). After 6 months riboflavin liver content is higher when ethanol replaces an equal amount of carbohydrate energy; this effect is reinforced by tannic acid. However liver vitamins contents was not affected by bisulfite.

[Effect of nitrite on the nutritional state of germ-free weaning rats (author's transl)]. / Effet du nitrite sur l'état de nutrition vitaminique B du rat axénique sevré.

For 14 days 2 groups of 10 young male Wistar rats in the germ-free state were fed on a chow ration, and to drink they were given either de-ionized water or a solution of sodium nitrite, 0.3 g per litre. At the end of the experiment thiamine, riboflavin, vitamin B6, niacin, biotin and pantothenic acid were estimated in various tissues (liver, kidneys, encephalon, heart, spleen, testes and muscle); nitrogen and phosphorus were estimated in the liver only. There was no difference between the groups in changes in body weight or fluid intake. But in the animals given sodium nitrite the liver weight was higher and there was an increase in kidney riboflavin content (+41 p. 100), and a decrease in heart riboflavin and vitamin B6 contents (-17 p. 100 and -10 p. 100, respectively) and liver pantothenic concentration (-26 p. 100). These results are different from those obtained with older S.P.F. rats [5], but are partially the same as those obtained with young S.P.F. rats [4].

[Effects of sodium nitrite on various vitamin concentrations in rat tissues]. / Effets du nitrite de sodium sur les concentrations en diverses vitamines de tissus de rat.

For 6 months 2 groups of 10 male Wistar rats were fed on a chow ration, and to drink they were given either de-ionized water or a solution of sodium nitrite, 0.3 g per litre. At the end of the experiment thiamine, riboflavin, vitamin B6, niacin, biotin and pantothenic acid were estimated in various tissues (liver, heart, muscle, encephalon, kidneys, spleen, lungs and duodenum); nitrogen, phosphorus, retinol and ascorbic acid were estimated in the liver only. There was no difference between the groups in changes in bodyweight or fluid intake, nor in weight of different organs. But in the animals given sodium nitrite there was an increase in riboflavin, vitamin B6, niacin and pantothenic acid spleen concentrations, and a decrease in liver niacin and encephalon biotin contents.

[Effect of a diet containing calcium pantothenate on urinary vitamin excretion and on the liver and kidney total pantothenic acid level in rats]. / Effet de la teneur du régime en pantothénate de calcium sur l'excrétion vitaminique urinaire et sur la teneur en acide pantothénique total du foie et du rein chez le rat.

Four groups of five adult rats weighing 310 g received during 20 days a diet containing 0, 1.68, 16.8 or 168 mumol of pantothenic acid per kg of diet. The daily urinary vitamin excretion was, in nmol per day: 32 +/- 8, 32 +/- 4, 180 +/- 23 and 2,100 +/- 91, respectively (mean +/- SEM). Liver and kidney pantothenic acid content was the same in all groups, in nmol per g of fresh tissue: 300 +/- 36 and 190 +/- 6, respectively (mean +/- SEM, n = 20).

[Effect of nitrites and nitrates on various aspects of vitamin nutritional status]. / Influence des nitrites et des nitrates sur certains aspects de l'état de nutrition vitaminique.

Nitrites--and sometimes nitrates--decrease the biological availability of dietary vitamins in several animal species. 1. Numerous studies show that ingested nitrites decrease the stock of liver vitamin A in nonruminants (Rat, Pig, Chicken); the effect of nitrates is less pronounced even lacking. In vitro, experiments allow to think that vitamin A and beta-carotene can be destroyed by nitrites in the diet and/or in the gastrointestinal tract. 2. Some recent works--those of Lhuissier particularly--show that nitrites can affect some vitamins of B group and their metabolism. Thiamine and vitamin B6 contents of several tissues decrease when nitrites are fed to the Rat. In the case of thiamine, the result could be partially explained by destruction of the vitamin in the diet and may be in the gastrointestinal tract. No such explanation seems to be possible in the case of vitamin B6.

Chronic exercise affects vitamin B-6 metabolism but not requirement of growing rats.

The effect of chronic exercise (forced swimming) on vitamin B-6 status and metabolism was studied in growing male rats fed deficient (0 mg pyridoxine-HCl/kg), suboptimal (2 mg pyridoxine-HCl/kg) or control (7 mg pyridoxine-HCl/kg) diets for 9 wk. Sedentary rats were fed the same diets. Body weight gain was lower in deficient rats than in both other dietary groups. Sedentary rats were heavier than trained rats of all diet groups. Erythrocyte aspartate aminotransferase, urinary 4-pyridoxic acid excretion, blood (plasma and erythrocytes) and tissue B-6 vitamers were measured. Urinary 4-pyridoxic acid, plasma pyridoxal 5'-phosphate and erythrocyte aspartate aminotransferase values of exercised and sedentary rats responded to changes in dietary pyridoxine but were not different from one another. After 9 wk of vitamin B-6 depletion, tissue concentrations of pyridoxal 5'-phosphate and pyridoxamine 5;5'-phosphate were 41-66% and 26-49% lower, respectively, in the deficient groups than in the control groups. Larger percentage differences occurred in plasma than in tissues (95 vs. 22-66%). In liver, pyridoxal 5'-phosphate concentrations were lower, whereas pyridoxal concentrations were higher in trained than in sedentary rats. In gastrocnemius muscle, pyridoxal 5'-phosphate, pyridoxamine 5'-phosphate and total vitamin B-6 concentrations were higher in trained than in sedentary rats. Concentrations of vitamin B-6 compounds in heart, kidneys, brain and adrenals were not affected by training. On the basis of the vitamin B-6-dependent variables measured in this study, we conclude that prolonged exercise affects the metabolism of vitamin B-6, but does not increase the vitamin B-6 requirement in growing rats.