Flow microcalorimetry as a tool for an improved analysis of antibiotic activity: the different stages of chloramphenicol action

Flow microcalorimetry in combination with photometric mass determination of staphylococci in suspension was used to reveal alterations in the intensity, extent and efficiency of bacterial metabolism during inhibition of protein synthesis by chloramphenicol. It could be demonstrated that these three parameters of metabolic activity were distinctly affected by this drug, and that the method described promises to be a more reliable tool for assaying the degree and the mode of bacteriostatic inhibition than the conventional determination of the minimum inhibitory concentration.     

Inhibition of phorbol myristate acetate and phytohemagglutinin stimulation of human lymphocytes by 13-cis-retinoic acid and ethyl etrinoate

Summary The retinol analogues 13-cis-retinoic acid and ethyl etrinoate inhibit the mitogenic activity of phorbol myristate acetate and phytohemagglutinin on human lymphocytes. This inhibitory effect is greater against the stimulation with phorbol myristate acetate than with phytohemagglutinin.This work was supported by a grant from the National Cancer Institute of Canada. We would like to thank Hoffmann-La Roche, Canada, for providing the 13-cis-retinoic acid and the ethyl etrinoate.     

Flow microcalorimetry as a tool for an improved analysis of antibiotic activity: The different stages of chloramphenicol action

Summary Flow microcalorimetry in combination with photometric mass determination of staphylococci in suspension was used to reveal alterations in the intensity, extent and efficiency of bacterial metabolism during inhibition of protein synthesis by chloramphenicol. It could be demonstrated that these three parameters of metabolic activity were distinctly affected by this drug, and that the method described promises to be a more reliable tool for assaying the degree and the mode of bacteriostatic inhibition than the conventional determination of the minimum inhibitory concentration.