Mécanisme d'action du chloramphénicol dans l'inhibition de la production d'anticorps induite par de différents types d'antigènes

Summary Chloramphenicol (CAF) administered to rabbits during the whole period of immunization, is able to suppress almost completely the antibody response against horse serum albumin and globulins (HSA, HSG) andEscherichia coli: on the other hand, it does not inhibit antibody response to heterologous RBC. The possible mechanism of the inhibiting action of the CAF in antibody response to HSA, HSG andE. coli is discussed, and some hypotheses are put forward on the possible reasons for the different behaviour of CAF on the immune response induced by heterologous RBC.     

Metabolic status of temperature induced swollen conidia ofAspergillus nidulans

Summary There is an active synthesis of DNA, RNA, protein, and carbohydrate in conidia incubated at 48°C. DNA increases more or less 3 times; while RNA, protein and carbohydrate are synthesized at a much faster rate. Conidia do not germinate at this temperature.Acknowledgments. Grateful thanks are due to Professor B. M. Johri for valuable suggestions. R. K. S. acknowledges with thanks a Senior Research Fellowship of the Council of Scientific and Industrial Research, New Delhi.     

Lymphatic metastasis of tumour; persistent transport of cells

Summary A model of lymphatic metastasis established by injecting Walker rat carcinoma cells into the rat footpad was used to study the output of tumour cells from the footpad. The lymphatic efferent from the footpad was cannulated in a group of rats with advanced neoplasm; it was shown that the output of tumou cells was continuou over periods up to 90 min and ranged from 10²–10⁵ cells/min.Acknowledgment. This work was supported by a grant from the National Cancer Institute of Canada to C.R.F. and I.C. We are grateful to Mrs W. Kao and Mr I. Etches for meticulous technical help and to the Photographic Section, Department of Pathology for illustrations. Dr V.S. Gupta of Veterinary Physiology, University of Saskatchewan supplied the tumour for transplantation.     

Mitogenic effect of sodium phenobarbital and rat liver arginase activity

Résumé Au cours de la régénération du foie normal des rats, on a constaté une augmentation — statistiquement significative — de l'activité arginasique dans la phase prémitotique. Chez des animaux traités par le phénobarbital, l'activité arginasique augmente encore davantage dans la phase prémitotique du foie régénéré.