Pathologia et microbiologia最新文献

A method for the isolation and purification of M protein was developed. Purified cell walls were sonically disrupted, solubilized M protein was precipitated by ammonium sulphate and then electrofocused. Both in this material and in hot acid extracts type-specific trypsin-sensitive antigens with two separately precipitating moieties were found. Evidence is adduced showing that they both belong to the M protein complex. The molecular weight of our purified M protein ranged between 400,000 and 20,000 daltons, giving a peak at 150,000 daltons. The pI of this material was found to be 5.4-5.6. There were marked differences between the behaviour of the low, medium and high molecular weight fractions obtained from purified M protein by gel filtration.

Haemophilus vaginalis is highly sensitive to oleandomycin. The MIC ranged from 0.035 to 0.15 mug/ml. The sensitivity of H. vaginalis to spectinomycin was 2.5-5.0 mug/ml. The sensitivity of H. vaginalis to spectinomycin is 3-4 times higher than that of Neisseria gonorrhoeae. A favourable effect in the treatment of vaginitis caused by H. vaginalis could thus be expected.

The development of hyperplastic and neoplastic lesions of parenchymal cells of the liver adjacent to central veins was observed in C3H mice ingesting the chlorinated hydrocarbons, dieldrin or aldrin, in the diet. Lesions could be followed from pericentral hyperplasia to areas of hyperplasia, nodules of hyperplasia, small hepatocellular carcinomas, and large well-developed carcinomas, occasionally with metastases. Sometimes pericentral hyperplasia was diffuse throughout most or all of one lobe of the liver. These hyperplastic cells collided to become one large nodule and also one large carcinoma. The carcinomas were well-differentiated or moderately well-differentiated and grew on transplantation to isologous hosts. Histologically, the hyperplastic cells adjacent to central veins were increased in size, frequently with double nuclei. Carcinoma cells varied in size and shape and were huge with large nuclei, prominent nucleoli, and eosinophilic cytoplasm. Similar hepatocellular carcinomas were seen previously with carbon tetrachloride, another organochlorine chemical.

Inoculation of mice with Newcastle disease virus (NDV) alters the course of infection with the Thogoto-like arbovirus Tho-Ar-126. The Tho-Ar-126 content of liver, spleen, and lymph nodes was approximately 10 times greater in mice treated with NDV 24 h before infection; the mortality was somewhat increased, but liver damage (as indicated by serum transaminase levels) did not seem to be potentiated. Lymphocytopenia was observed in NDV-inoculated mice, and in the spleen and lymph nodes the proportion of lymphocytes susceptible to lysis by anti-theta (a marker for thymus-derived lymphocytes) was markedly decreased in these animals. This suggests that NDV potentiates infection by Tho-Ar-126 through its action on thymus-derived lymphocytes.

A new herpesvirus recovered from the kidneys of mature ground squirrels (Citellus citellus) produced an effect in tissue culture cells resembling that of herpesviruses, including the formation of multinucleated syncytia and type A intranuclear inclusions. The isolate caused latent infection in the natural host, but it proved fatal for intracerebrally inoculated suckling mice and it produced pocks on the chorioallantoic membrane of embryonated eggs. Electron-microscopic examination of infected cells revealed intranuclear virus particles exhibiting a size and ultrastructure characteristic of herpesviruses. The isolate was ether-resistant and a DNA nucleic acid type was inferred from observations on inhibition by fluorinated pyrimidine. This ground squirrel herpesvirus was found to be antigenically distinct from Herpesvirus hominis and from ground squirrel cytomegalovirus, with no detectable cross-reactivity.