No abstract

No abstract

SUMMARYT-mycoplasmas were isolated by a ' colour-change ' technique, involving the metabolism of urea, from 16 of 49 slaughtered cows (33 %). They were encountered more often in the urethra and bladder than in the vagina. Isolations were made usually within 2 days of incubation but occasionally 5 days was required. T-mycoplasmas were isolated in medium without inhibitors from urethral scrapings of a cow and from seminal fluid of a bull. On solid medium, bovine T-mycoplasmas produced colonies of 5-1 2p which were similar to those produced by a T-mycoplasma from the human urogenital tract. In liquid medium, the growth cycle of bovine T-mycoplasmas was similar to that of human T-mycoplasmas, being more rapid than that of large colony-forming (classical) mycoplasmas. The presence of serum in the medium was necessary for growth. T-mycoplasmas of bovine origin were affected in a similar way to those of human origin when subjected to ether, heat, freezing and thawing, freeze-drying, antibiotics and thallium acetate ; they were more sensitive to erythromycin and thallium acetate than some classical mycoplasmas. The size of the minimal reproductive forms of bovine and human T-mycoplasmas and a classical mycoplasma, Mycoplasma hyorhinis, was similar as judged by filtration experiments. Electron microscopy of bovine and human T-mycoplasmas revealed cells which varied in size from 80 mp to 420mp, and which were bounded by a triple-layered membrane, features similar to known classical mycoplasmas.

No abstract

INTRODUCTION THE passage of large amounts of protein and other compounds from the nerve cell body down the axon is a widely accepted phenomenon to which the term axoplasmic flow has been applied (see Barondes, 1967). Substances may also travel in a retrograde fashion from the periphery of the axon to the neuron (Lubinska,