Selenium from selenium-rich Spirulina is less bioavailable than selenium from sodium selenite and selenomethionine in selenium-deficient rats.

The bioavailabilty of selenium (Se) from selenium-rich Spirulina (SeSp) was assessed in Se-deficient rats by measuring tissue Se accumulation and glutathione peroxidase (GSH-Px) activity. For 42 d, rats were subjected to dietary Se depletion by consumption of a Torula yeast (TY)-based diet with no Se; controls were fed the same diet supplemented with 75 microg Se/kg diet as sodium selenite. Se-deficient rats were then repleted with Se (75 microg/kg) by the addition of sodium selenite, selenomethionine (SeMet) or SeSp to the TY basal diet. Selenium speciation in SeSp emphasized the quasi-absence of selenite (2% of total Se); organic Se comprised SeMet (approximately 18%), with the majority present in the form of two selenoproteins (20-30 kDa and 80 kDa). Gross absorption of Se from SeSp was significantly lower than from free SeMet and sodium selenite. SeMet was less effective than sodium selenite in restoring Se concentration in the liver but not in kidney. SeSp was always much less effective. Similarly, Se from SeSp was less effective than the other forms of Se in restoring GSH-Px activity, except in plasma and red blood cells where no differences were noted among the three sources. This was confirmed by measuring the bioavailability of Se by slope-ratio analysis using selenite as the reference form of Se. Although Se from SeSp did not replenish Se concentration and GSH-Px activity in most tissues to the same degree as the other forms of Se, we conclude that it is biologically useful and differently metabolized due to its chemical form.

Iron availability from iron-fortified spirulina by an in vitro digestion/Caco-2 cell culture model.

Iron deficiency, one of the most important nutritional problems in the world, can be caused not only by foods deficient in iron but also by poor availability of dietary iron. Iron food fortification in combination with highly available iron from supplements could effectively reduce this deficiency. The aim of this study was to examine the iron availability from iron-fortified spirulina. We have used an in vitro digestion/Caco-2 cell culture system to measure iron spirulina availability and made a comparison with those of beef, yeast, wheat floor, and iron sulfate plus ascorbic acid as a reference. Iron availability was assessed by ferritin formation in Caco-2 cells exposed to digests containing the same amount of iron. Our results demonstrate a 27% higher ferritin formation from beef and spirulina digests than from digests of yeast and wheat flour. When iron availability was expressed per microgram of iron used in each digest, a 6.5-fold increase appeared using spirulina digest in comparison with meat. In view of this observed high iron availability from spirulina, we conclude that spirulina could represent an adequate source of iron.

Production of polyclonal antibodies towards the immunodetection of insecticide phosalone.

Hapten synthesis for the production of specific insecticide phosalone polyclonal antibodies was carried out starting from an intermediate of the phosalone synthesis, 6-chloro-2-benzoxazolone 1. Two haptens containing different spacers have been prepared: N-5-carboxypentyl-6-chloro-2-benzoxazolone 7 and N-(2-oxo-3-aza-5-carboxypentyl)-6-chloro-2-benzoxazolone 12. Each of these two haptens conjugated to bovine serum albumine (BSA) was used to immunize four rabbits. Immunoassays of phosalone were performed with ELISA using solid-phase bound hapten thyroglobulin conjugate and horseradish peroxidase labelled goat antirabbit IgG. The more sensitive response was observed when the antiserum obtained from the rabbit immunized with the hapten-BSA conjugate containing the N-2-oxo-3-aza-5-carboxypentyl spacer was in competition with the same hapten coupled to thyroglobulin. An identical response was obtained under the same conditions when using benzoxazolone instead of phosalone as competitor, showing a good recognition of the specific aromatic part of the organophosphate insecticide phosalone. Reduction of coating conjugate concentration (from 2 to 0.05 micrograms/well) and also the use of heterologous coating protein instead of homologous did improve the sensitivity, resulting in a concentration of phosalone required to inhibit binding by 50% of 2 mg/l and a detection limit of 0.02 mg/l.

[Cytochemical ultrastructural study of adenosine 5'monophosphate hydrolysis in human spermatozoa]. / Etude cytochimique ultrastructurale de l'hydrolyse de l'adenosine 5'monophosphate dans le spermatozoide humain.

A specific 5'nucleotidase activity (pH 7.4) is localized by cytochemical technics, in the head (nuclear membrane, periacrosomal cytoplasm) and in the mitochondrial membrane of human spermatozoa. The effect of different effectors (manganese, nickel, fluoride, tartrate, tetramisole), studied in the head by rate assessment of cells with or without hydrolysis sites, changes the cellular distribution, the depth of reactions and their localization. The 5'nucleotidase interferences with some unspecific phosphatases are discussed.

Nutritional value and intestinal effects of dipeptides and tripeptides. Comparison with their issuing bovine plasma protein in rats.

A hydrolysate containing 75% di- and tripeptides (DTP) was prepared from bovine plasma proteins (BP) and the original protein and hydrolysate were compared for nutritional value. Food intake, protein efficiency ratio (PER), nitrogen balance and digestibility and plasma amino acid concentrations were measured in young rats receiving the diets over 17 days. Moreover, intestinal adaptation was evaluated in duodenum, jejunum and ileum, with the aid of light microscopy and enzyme analyses; tritiated thymidine incorporation was also measured. In DTP- and BP-fed rats, food intake, body weight gain, nitrogen balance and digestibility as well as PER were similar. Plasma amino acid concentration analyses showed an increased concentration of threonine and valine in the BP-fed group. Measurements of mucosal enzyme activities suggest adaptation to the diets especially in the ileum as indicated by increasing aminopeptidase N and dipeptidyl peptidase IV specific activities in the BP-fed group. This group also displayed substantial 3H-thymidine incorporation. It is concluded that the hydrolysate containing di- and tripeptides is efficiently utilized in healthy growing rats, though the efficacy is not higher than with the BP diet except for the difference in 3H-thymidine incorporation.

[Effect of an acidic sulfated polysaccharide on whole blood coagulability. In vivo study in rats]. / Action d'un polysaccharide sulfaté acide sur la coagulabilité globale du sang. Etude in vivo chez le rat.

Armatan, an acid sulphated polysaccharide isolated from a red marine seaweed Asparagopsis armata (Harv.), increases the coagulation time of the rat plasma in vivo assays. This property presents, with administration, time and dose, some variations. Among the three ways studied, subcutaneous injection gives more interesting results than the others. At high concentrations (10, 20 and 50 mg/kg), intravenous administration induces plasma and organic (liver-spleen) diseases.

[Characteristics of the action of an acidic sulfated polysaccharide on global blood coagulation in vitro. Preliminary study in various species of mammals and in man]. / Particularités de l'action d'un polysaccharide sulfaté acide sur la coagulation globale du sang in vitro. Etude préliminaire chez différentes espèces de Mammifères dont l'Homme.

An acid sulphated polysaccharide, isolated from a red marine seaweed, Asparagopsis armata ( Harv .), increases the coagulation time of the plasma in vitro studies. This property, compared with the anticoagulant activity of pentosan polysulphate and heparin, pr esents , with concentration and temperature, some variations in man and other mammals . The rat and human plasma seem to behave in the same way with this substance.

[Effect of methylmercury chloride on mitosis in human lymphocytes in culture: ultrastructural study]. / Action du chlorure de méthylmercure sur la mitose de lymphocytes humains en culture : étude ultrastructurale.

The ultrastructural study of proliferating human lymphocytes poisoned by methylmercury chloride, shows that this product disorganizes and alters the different constituents of the mitotic figure. The chromosomes, partially decondensed, are covered with protuberances and connected by various chromatin bridges. Tubular structures are changed. In disorganized cellular centers, the badly bounded centrioles are often thickened. Membraneous systems are altered.

[Acute toxicity of two phenylcarbamates: propham and chloropropham]. / Etude de la toxicité aiguë de deux Phénylcarbamates: le propham et le chloropropham.

The bibliographic data dealing with the acute toxicity of two phenylcarbamates, propham and chloropropham, are not very precise an often contradictory. This work is a restatement and also a demonstration of the high sensitivity of the aquatic animals that we have tested (Amphibia and Crustacea) in comparison with the Mammals (rat and mouse).

[Effects of propham and chlorpropham on the embryonic development of various vertebrates]. / Effet du propham et du chloropropham sur le développement embryonnaire de quelques vertébrés.

The effect of propham and chlorpropham on Amphibians embryonic development changes with doses as well as species. The action of C.I.P.C. is always determinative. The egg poisoned in albumen involves important chick embryo malformations, but the development is stopped by the yolky vesicle poisoning. The intraperitoneal injection of C.I.P.C., strongly disturbs fetus physiology in Mouse.

[Effects of propham and chloropropham on mitosis in cultured human lymphocytes. Ultrastructural study]. / Action du propham et du chloropropham sur la mitose de lymphocytes humains en culture. Etude ultrastructurale.

Propham and Chloropropham disturb the several mitotic figure components of proliferating human lymphocytes. The tubular structures, affected in preference by the C.I.P.C., become abnormal, disorganized or disappear. The chromosomal changes (protuberances,absence of condensation and chromosomal bridges) are principally given by I.P.C. I.P.C. and C.I.P.C. lead to the disappearance of the endoplasmic reticulum. These effects are correlated with the action of the two pesticides on DNA and protein synthesis.