Protective effect of selenite on nitrite toxicity.

Selenite was found to decrease nitrite-induced mortality in a dose-dependent manner. Its effect seems to be due to its action in reducing methemoglobin formed by nitrite.     

Protective effect of vitamins against trichothecene toxicity towardsSaccharomyces cerevisiae

Summary Several trichothecene mycotoxins were shown to inhibit the growth ofSaccharomyces cerevisiae. This effect was most pronounced with the macrocyclic trichothecenes, especially verrucarin A. Much less growth inhibition was observed with T-2 toxin. Verrucarol, diacetoxyscirpenol, acetyl T-2 toxin, HT-2 toxin, T-2 tetraol and neosolaniol were inactive at a concentration of 75 g of toxin per disc. Incubation ofS. cerevisiae with verrucarin A together with vitamins resulted in a decrease in toxicity. Pyridoxine-HCl, Ca-pantothenate, thiamine-HCl and -tocopheryl acetate were amongst the most potent of the vitamins tested which reversed growth inhibition, overcoming the inhibitory potential of the toxins.9 December 1986The authors thank Dr J. Behrend, Makor Company, Israel, for a generous gift of verrucarin A and roridin A.     

Protective effect of native levan on endotoxin toxicity in mice and rats

Summary High polymer levan administered to mice and rats before the injection of endotoxin partly protects the animals from the lethal effects of the LPS.This study summarizes a thesis in partial fulfilment of the requirements for the degree of Master of Medical Sciences in the School of Continuing Medical Education of the Tel-Aviv University Sackler Medical School.     

Protective effect of vitamins against trichothecene toxicity towards Saccharomyces cerevisiae

Several trichothecene mycotoxins were shown to inhibit the growth of Saccharomyces cerevisiae. This effect was most pronounced with the macrocyclic trichothecenes, especially verrucarin A. Much less growth inhibition was observed with T-2 toxin. Verrucarol, diacetoxyscirpenol, acetyl T-2 toxin, HT-2 toxin, T-2 tetraol and neosolaniol were inactive at a concentration of 75 micrograms of toxin per disc. Incubation of S. cerevisiae with verrucarin A together with vitamins resulted in a decrease in toxicity. Pyridoxine-HCl, Ca-pantothenate, thiamine-HCl and alpha-tocopheryl acetate were amongst the most potent of the vitamins tested which reversed growth inhibition, overcoming the inhibitory potential of the toxins.     

The effect of sodium nitrite on red cell GSH

Zusammenfassung Bei der Nachuntersuchung der Nitritwirkung auf das GSH der unversehrten Erythrocyten konnte nur ein geringfügiger Effekt festgestellt werden. Die früher mitgeteilte totale Zerstörung der GSH wurde auf einen Artefakt zurückgeführt, der während der Eiweissfällung mit Metaphosphorsäure auftrat.

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Supported in part by U.S.P.H.S. Grants H-5313 and H-5292.     

The protective effect of small amounts of selenite in sublimate intoxication

Résumé L'injection de très petites quantités de sélénite de sodium, administrées simultanément ou 1 h après l'intoxication par le sublimé corrosif, en abaisse considérablement la toxicité: les rats blancs intoxiqués par une dose létale de sublime corrosif survivent sous l'effet du sélénite dans un % important et les lésions typiques des reins et d'autres organes n'apparaissent pas.     

Protective effect of flavonoids on the collagen of lathyritic rats

Riassunto È stato determinato il collagene neutro solubile dell'aorta in ratti trattati con latirogeni (, -iminodiproprionitrile, aminoacetonitrile) e flavonoidi [O-(-idrossietil)rutosidi o (+)-catechina]. Il contenuto in collagene solubile è aumentato negli animali trattati con i latirogeni, mentre non risulta modificato qualora i latirogeni vengano somministrati ad animali trattati con flavonoidi.     

Protective effect of interferon on the target cells of cytotoxic lymphocytes

Interferon treatment of sensitized T lymphocytes enhances cytotoxicity against target cells. On the contrary, the same treatment of the target cells alone protects them, whatever the cytotoxicity of effector cells might be. We suggest that the cells having once survived contact with cytotoxic T lymphocytes could become resistant to any new attack by the same cells.     

Protective effect of ferric dextran on the embryopathic action of indium

Zusammenfassung Nach Indiumnitratinjektion bei Goldhamstern mit 8-tägiger Schwangerschaft wird eine erhöhte Mortalität der Embryonen sowie Gliedmassenanomalie gefunden. Bei gleichzeitiger Verabreichung von Eisendextran (Imferon) werden die Embryonalschäden weitgehend unterdrückt.     

The effect of cold and diazepam on the toxicity of fenfluramine in mice

Zusammenfassung Kaltbehandlung und i.v. Injektion von Diazepam reduzierten die Toxizität des Fenfluramins bei der Maus beträchtlich.     

Peculiar response of Brattleboro rats to selenite

Summary Brattleboro rats were given, on the 10th day of life, a single high dose of sodium selenite. 90% of Brattleboro heterozygotes responded to the treatment by the formation of cataract whereas homozygotes with diabetes insipidus exhibited no cataract.     

Protective effect of magnesium pemoline against lethal doses of X-irradiation

Zusammenfassung Magnesium-Pemolin, bekannt als gedächtnisstärkendes Arzeimittel, besitzt eine erhebliche Schutzwirkung gegen ionisierende Strahlen. Dieser strahlentherapeutische Effekt betrifft sowohl kurze, als auch langdauernde Wirkungsperioden.

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This work was supported in part by Grant No. 2-46-33-90-3-10 from the University of Illinois Foundation.     

The effect of monensin and chloroquine on the endocytosis and toxicity of chimeric toxins

The toxicity of two conjugates containing ribosome-inactivating proteins (RIPs, i.e. saporin and ricin-A chain x-linked to transferrin) has been measured on a prostatic cancer line (PC3) naturally overexpressing the transferrin receptor, in the presence of monensin and chloroquine. This paper investigates whether the increased toxicity of Tf-RIPs induced by monensin and chloroquine may be due to alterations of the normal endocytotic pathway of the complexes mediated by the transferrin receptor. Monensin, besides inducing alkalinization of normally acid intracellular compartments, causes an accumulation of the receptor-bound Tf-RIP in a perinuclear region contiguous to the cisternae of the trans-Golgi network. Chloroquine, though increasing the intracellular pH, seems not to modify the endocytotic pathway of these chimeric molecules. We believe that the enhanced toxicity of the Tf-RIPs may be related to intracellular alkalinization (i.e. endosomal or lysosomal pH) rather than to the effects on the recycling of transferrin receptor-bound toxins. We conclude that the efficacy of chimeric toxins may be modulated not only by the carrier used for their engineering but also by addition of drugs able to influence the stability and activation of the toxins inside the cell. Received 22 December 1997; received after revision 30 March 1998; accepted 15 May 1998