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W TRAGER

Publications and source records attributed to W TRAGER.

26 records · Page 2Linked to original sources
PubMed1953

The development of Leishmania donovani in vitro at 37 degree C; effects of the kind of serum.

Suspensions of leishmanias from the spleen of hamsters infected with Leishmania donovani were placed in culture flasks and incubated at 37 degrees C. In a medium of human erythrocyte extract and human serum there appeared within a day or two aflagellate forms resembling leishmanias but larger, as well as other aflagellate forms more nearly resembling rounded leptomonads. These intermediate forms multiplied during the first 4 days of culture. They then slowly died off, despite frequent renewal of the culture medium. Sometimes a small proportion of motile, typical leptomonads also appeared in such cultures. Leptomonads from cultures maintained at 28 degrees C., when placed in the human red cell extract-human serum medium and incubated at 37 degrees C., survived at least 4 days. For both types of effect, human serum could be replaced by normal hamster serum but not by rabbit serum. Nicotinamide, added to the human red cell extract-human serum medium at a concentration of 400 mg. per 100 ml., completely prevented the development of intermediate forms from leishmanias and brought about the rapid death of leptomonads at 37 degrees C.

Animals↗
PubMed1952

Studies on the extracellular cultivation of an intracellular parasite (avian malaria). II. The effects of malate and of coenzyme A concentrates.

The extracellular survival and development in vitro of the erythrocytic stages of Plasmodium lophurae were favored by the addition to the culture medium of l-malic acid and concentrates rich in coenzyme A. In a concentrated extract of duck erythrocytes supplemented with these two substances in addition to adenosinetriphosphate, sodium pyruvate, and certain other materials of like nature, only 5 to 10 per cent of the extracellular parasites had become abnormal after 3 days of cultivation.

Adenosine Triphosphate↗
PubMed1950

Studies on the extracellular cultivation of an intracellular parasite (avian malaria). I. Development of the organisms in erythrocyte extracts, and the favoring effect of adenosinetriphosphate.

The erythrocytic stages of Plasmodium lophurae were freed from their host red cells by specific hemolysis directly into a favorable medium containing an extract of duck erythrocytes. Extracellular survival and development of the parasite in vitro occurred in culture media consisting essentially of a very concentrated extract of duck red cells prepared in a special nutrient solution. Omission or dilution of the red cell extract resulted in rapid degeneration of the parasites. Their survival and development were favored by the presence in the erythrocyte extract of gelatin, yeast adenylic acid, and cozymase, and especially by the further addition of adenosinetriphosphate and sodium pyruvate. Under the best conditions yet tested, all the free parasites continued their development extracellularly during the first two days of cultivation. Merozoites formed by the extracellular segmentation of the free parasites originally present developed further into trophozoites. On the third day a majority of the free parasites were still of normal appearance, but by the fourth day more were degenerate, and very few normal parasites remained on the fifth day.

Adenosine Triphosphate↗