J. Francis

The distribution of sulphone in the tissues of various animals

Summary Concentrations of sulphone were higher in the liver than in the blood of the mouse, pig, dog and sheep, but not of the bovine. The concentrations were not consistently higher in the skin than in the blood of mice, pigs, dogs and sheep. In the bovine they were lower. The concentrations in other tissues differed little from those in the blood. The lower concentrations in the tissues of the bovine may partly explain the lower toxicity of sulphone in this species. Concentrations in the brain of sheep were only slightly lower than in the blood, whereas in the adult bovine they were much lower. This may explain the much lower tendency of cattle than sheep to develop nervous symptoms. Concentrations of sulphone in the brain of young mice were relatively and absolutely greater than in old mice, which again may explain the greater liability of young than old mice to develop nervous symptoms.

Some observations on infection of the bovine udder with Mycobacterium tuberculosis and Corynebacterium pyogenes.

Summary A small herd was divided into groups of four cows each and pooled samples of milk from each group were examined on eight occasions. Two guinea-pigs were each injected intraperitoneally with 10 ml. from every sample of milk, i.e., approximately 1·25 ml. of milk from each quarter was examined on each occasion. Two guinea-pigs developed very slight tuberculosis. Five guinea-pigs inoculated with the milk died and showed lesions from which pure cultures of C. pyogenes were isolated. An abscess containing C. pyogenes was found in one other guinea-pig. All but one of the infected guinea-pigs were injected with milk from group 2 and one cow in this group subsequently developed a typical infection of C. pyogenes in the udder. C. pyogenes was isolated from the udder of a cow in another herd that developed no obvious disease. It is suggested that both tubercle bacilli and C. pyogenes may occasionally pass from the blood stream into the milk. They may then be eliminated, or give rise to subclinical or clinical infections.

Studies on Streptococcus Agalactiae Infection: I.—Infection of the Chick-Embryo and Mouse

Summary A strain of Str. agalactiae was carried through 37 direct passages in the chick-embryo, and 33 in the mouse. The nature of the infection in these hosts is described and compared with infection by Group A streptococci. The virulence of various strains of Str. agalactiae and of Group A streptococci was compared in the chick-embryo and mouse. There was no correlation between virulence for these two hosts.

Studies On Str. Agalactiae Infection: III—The Relative Potencies of Sulphanilamide, Sulphapyridine, 4: 4′-Diamino-Diphenyl Sulphone and Various Soluble Derivatives Against Str. Agalactiae Infection in the Chick-Embryo and Mouse

Summary The relative potencies of sulphanilamide, sulphapyridine, 4- : 4′-diaminodiphenyl sulphone and various soluble derivatives of these compounds were compared in the chick-emhryo and mouse. The results with the free compounds have, in general, confirmed those obtained previously and are summarised in Tables III and IV. With the exception of sulphanilamide L.S.F., which was of very low activity, the soluble derivatives had about the activity one would expect from the amount of active drug they contain. The results, however, varied somewhat with the route of administration. These differences, together with the application of the findings to the treatment of mastitis, arc briefly discussed.

Studies on Streptococcus Agalactiae Infection: IV.-Attempts to Produce Immunity in the Mouse

Summary The mouse-avirulent strain of Str. agalactiae (A4) was inoculated subcutaneously in an attempt to vaccinate mice, and immunity was tested by the intraperitoneal injection of the mouse-virulent strain. Cultures of varying ages were used for vaccination, the vaccinating dose was sometimes suspended in oil, and immunity was tested at periods varying from seven to 42 days. There was no evidence that resistance had been increased. despite the fact that the vaccinating dose often produced a small abscess which had usually healed before the test dose was given.