Cholera toxin genes: nucleotide sequence, deletion analysis and vaccine development

Nucleotide sequence and deletion analysis have been used to identify the regulatory and coding sequences comprising the cholera toxin operon (ctx). Incorporation of defined in vitro-generated ctx deletion mutations into Vibrio cholerae by in vivo genetic recombination produced strains which have practical value in cholera vaccine development.     

Comparison of the time courses of luteinizing hormone (LH) secretion rates during continuous stimulation by LH-releasing hormone (LH-RH) in vivo and in vitro

The patterns of LH secretion during constant stimulation of the pituitary glands of estradiol-treated ovariectomized rats with a maximally stimulating amount of LH-RH in vivo and in vitro correspond with each other qualitatively and quantitatively. In vitro the changes with time of the LH secretion rate are somewhat retarded, especially the occurrence of desensitization.     

Studies on vesiculated and non-vesiculated hypothalamic neurosecretory cells in the dog

Resumen El tamatroyel número de neuronas vesiculadas en los núcleos neurosecretores del perro están significativamente correlacionados con el largo axonal. Despues de la sección del tallo hipofisiario, las células vesiculadas degeneran más rapidamente que las no-vesiculadas. Estos resultados permiten suponer que las vesículas neurosecretoras se originan como resultado de mecanismos de secreción neuroapocrina en los axones.     

Molecular forms of dopamine beta-hydroxylase in rat superior cervical ganglion and adrenal gland

Summary Dopamine beta-hydroxylase (DBH) enzyme activity was associated in rat superior cervical ganglion with tetrameric DBH-A (294,000 D) and dimeric DBH-B (147,000 D) and in rat adrenal gland with DBH-A and a novel molecular form of DBH, defined as DBH-C, with a molecular weight of 125,000 D. Pretreatment of the rats with cycloheximide markedly reduced DBH activity without altering the molecular heterogeneity.     

Morphological effects of serotonin and ketanserin on embryonic chick skin in vitro

Cell and organotypical cultures are used to study the direct effect of serotonin and of ketanserin, a serotonin antagonist, on dermal and epidermal cells of embryonic chick skin. Ketanserin stimulates the increase in cell number and inhibits the differentiation, whereas serotonin stimulates differentiation and inhibits the increase in cell number.     

Preliminary purification and dosages of the erythropoietic factor from ox-spleen.

The administration of ox-spleen homogenate, whether in rats made polycythemic by blood transfusion or in mice polycythemic by hypoxia, elicited a significant stimulatory effect on the rate of erythropoiesis. This activity remained unchanged even if the spleen, before being homogenized, was exhaustively washed with isotonic buffer pH 7.4 up to the total blood elimination.     

Inhibition of cytosolic rat hepatic glutathione S-transferase activities by bromosulfophthaleins

Summary The enzymatically catalyzed conjugation of glutathione with 1-chloro-2,4-dinitrobenzene and styrene-7,8-oxide is inhibited by tetrabromosulfophthalein in a non-competetive way, although tetrabromosulfophthalein itself is a substrate for glutathione S-transferases. Dibromosulfophthalein, which is not a substrate for glutathione S-transferases, inhibits the 1-chloro-2,4-dinitrobenzene conjugation competetively and the styrene-7,8-oxide conjugation non-competetively.     

Interaction of benznidazole reactive metabolites with nuclear and kinetoplastic DNA, proteins and lipids from Trypanosoma cruzi

Epimastigotes of Trypanosoma cruzi (Tulahuen strain Tul 0 stock) biotransform benznidazole (N-benzyl-2-nitro-1-imidazole acetamide) to reactive metabolites that bind covalently to DNA, proteins and lipids of the parasite. These effects might be related to the trypanocidal action of benznidazole, a chemotherapeutic agent against Chagas' disease.     

Criteria for the evaluation of the antirheumatic (antiinflammatory drugs in man]

Comparison of 5 antiinflammatory drugs and placebo in a double blind, short term, cross-over trial conducted in patients suffering from rheumatoid arthritis. 15 measurements were used and studied. With classical unidimensional statistical tests it was not possible to discriminate active drugs between them. Multidimensional analysis (correspondance analysis and discriminant analysis) are more sensitive and allow us to distinguish active drugs with only 11 criterion.