Microheterogeneity of staphylococcal enterotoxin C2

Résumé L'hétérogénéité de l'entérotoxine C₂ d'un staphylocoque par électrophorèse en gel polyacrylamide est reliée à la présence d'isomers de charge différente.

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Acknowledgments. We thankDebbie Jeffrey, Yukio Yano andRobert Gagné for excellent technical assistance.     

Ethanol as a ‘food’ forDrosophila melanogaster: Influence of theEbony gene

Summary The survival time of adultDrosophila melanogaster flies without food is greater in the presence of ethanol, especially for flies of strains or lines with a higher alcohol dehydrogenase activity. It seems that theebony gene can act in some populations as a selective factor favoring the ADH^F allele, as well as the minor genes enhancing the alcohol dehydrogenase activity level.Chargé de Recherches au F. N. R. S.     

Gastric mucus effusion elicited by oral copper compounds: Potential anti-ulcer activity

Summary In rats, both Cu(I) and Cu(II) show an irritancy profile not shared with Cu^o or Zn(II) or Ni(II). The gastric response to Cu(II), i.e. copius fluid and mucus secretion, can protect the stomach from the acute ulcerative effects of aspirin or physical stress administered subsequently.to whom all enquiries should be addressed, Supported by grants from the National Health and Medical Research Council (Austr.) and University of Tasmania Research Commitee.Acknowledgments: ProfessorsW. R. Walker (Newcastle, Austr.) andL. Field (Nashville, Tenn.) for gifts of Cu(I) and Zn complexes;Dr. J. R. J. Sorenson (Cincinnatti, Ohio) for illuminating discussion; Drs.D. D. Perrin (Canberra) andR. P. Agarwal (Washington D. C.) for providing stability constants and much helpful advice.     

Adaptation of the pituitary gland to prolonged LRH stimulation

Summary With prolonged constant rate infusion of luteinizing hormone-releasing hormone (LRH), the LH secretion rate of the rat pituitary gland changes continuously until a steady state of relative desensitization has developed. Recovery from this state can occur independently from changes in the pituitary's LH content.     

Cellular control of the tick-borne virus antigen production in persistently infected cell culture

Summary The influence of inhibition or stimulation of cellular DNA synthesis on tick-borne virus antigen production in persistently infected cell culture was studied. Either mitomycin C or cytosine-arabinoside caused cessation of antigen-containing cell number increase. Stimulation of cellular DNA synthesis by growth medium change increased the level of antigen-containing cells. When HEp-2-Sof culture was synchronized, a correlation was observed between the entrance of cells into DNA synthesis phase and the increase of proportion of antigen-containing cells.     

Bursal dissections and gill pouch hormones.

The terrestrial survival of birds and mammals depends on evolutionary chantes in cloacal bursae and gill pouches. Comparative dissections of these pouches provide insight into the coordinated functions of cervical endocrine organs, especially as they affect lymphoid tissue.