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Scientific Proceedings (128) 



positive results (i. e., 5/7 specimens positive). None of the seven 

 blood specimens from six who had received 28.68 to 77.64 mg. 

 of antimony per kilogram of their weights showed any Leish- 

 man-Donovan bodies. The method followed was to withdraw a 

 column of blood 1 to 2 cm. high in a fine capillary pipette from 

 the bottom of the conical tube in which the diluted blood speci- 

 men was centrifuged. The smears were made on slides in the 

 usual manner. Wright's or Leishman's stain was used. 



1. The effect of human red cells and serum on the growth of 

 Leishmania donovani has been studied and a blood culture method 

 devised, based on these findings. 



2. The distribution of blood platelets and of the different 

 varieties of leucocytes in the strata of centrifuged diluted blood 

 has been investigated and also the distribution of Leishman- 

 Donovan bodies, extracellular and intracellular in these strata. 



3. The effect of treatment with antimony on the cultivability 

 of Leishmania donovani has been studied. 



Conclusions 



1. Human red cells in a culture medium permit only a feeble 

 growth of Leishmania donovani. 



2. Human serum, whether inactivated or not is distinctly in- 

 hibitory to the growth of this parasite. 



3. If an adequate amount of blood is taken (10 c.c.) and 

 most of the serum and red cells removed by centrifugation, 

 positive cultures may be obtained in about 90 per cent, of un- 

 trated cases of kala-azar. 



4. By this technic positive cultures may be obtained as fre- 

 quently from peripheral blood as from spleen punctures. 



5. Extracellular Leishman-Donovan bodies are approximately 

 of the size and specific gravity of platelets and are found in the 

 "platelet fraction" of centrifuged diluted blood. 



6. Mononuclear and polymorphonuclear leucocytes with the 

 contained intracellular forms are usually heavier than the other 

 blood cells and go to the bottom of the tube on centrifugation or 

 sedimentation. 



7. In the series of cultures made, the blood of patients treated 

 intravenously with antimony salts became free from cultivable 

 Leishmania donovani after they had received about twelve milli- 

 grams of antimony per kilogram of their body weights. 



8. Cultures from spleen punctures show similar results. 



