Study of the pathogenesis of toxoplasmosis by means of tagged atoms]

The authors' investigations showed a principal possibility of labeling toxoplasma with radioactive isotopes on condition of the administration of the latter in vivo into the donor animals infected with toxoplasmosis. The labeled atom method could be used for studying the pathogenesis of toxoplasmosis in the experimental animals, particularly at the early periods of the infectious process. The use of the labeled atom method permitted not only to confirm the results obtained by parasitological and pathomorphological studies, but also to reveal the fact of a primary parasitemia, later confirmed by biopsy. In combination with other methods of study the labeled atom method can be used for studying various aspects of the problem of toxoplasmosis, particularly of the mechanisms of transmission of the infection.     

On the pathogenesis of diphtheria

Summary By means of the paper-chromatographic method an attempt was made to gain an insight into the excretion of amino-acids in the saliva of adult men and women. The amino-acids in this saliva were separated from accompanying obstructives (mucines, proteins, etc.) by dialysis through cellophane membranes. The fairly large quantities of salts were removed by electrolysis. We obtained “twodimensional chromatograms”, phenol and a mixture of collidine and lutidine having been used as solvents. With respect to the above-mentioned excretion of amino-acids in the saliva of 50 adult men and 50 ditto women, there were notable differences between the sexes. On the whole, the examined saliva samples of the women presented a fairly uniform picture. Only one amino-acid pattern showed more than 10 amino-acids. Among the 50 men, on the other hand, there were 10 cases where the examined saliva samples contained from 11 to 15 amino-acids. Quantitatively, too, a distinct difference between the sexes could be demonstrated. With the exception of valine and taurine, the men excrete larger quantities of all the amino-acids in their saliva, than the women whose saliva was examined. Part I:A. Tasman andL. Smith, Antonie van Leeuwenhoek19, 135, 1953.     

On the pathogenesis of spontaneous parvovirus infection

The internal organs of 21 beagles spontaneously infected with parvovirus were examined histologically and in 10 of the dogs immunofluorescence examination was also performed. The study showed that the pathological process had started in the small intestine and from there the viral agent had spread through the regional lymph nodes into the other lymphatic and the haemopoietic organs causing there depletion predominantly of lymphocytes and arrest of haemopoiesis. Four dogs displayed conspicuous oedema of the media of the arterioli in the liver. In the cytoplasm of probably Kupffer's cells specific fluorescence was present in all the 10 dogs examined. On the other hand neither viral antigen nor histological changes were found in kidneys. Our observations suggest that spontaneous infection of dogs with parvovirus takes place per os. Parvovirus is not eliminated from the organism with urine.