KEVIEW — TROPICAL MEDICINE, ETC. 207 



Niereustein^ has conducted observations on the acidity and alkalinity of the blood in Trypano- 

 trypanosome infection, and concludes : — somiasis— 



i. It is evideut that iu experimental trypanosomiasis infection {T. hrmxi and ?'. eqiiipeirliiiu), the acidity of 

 the blood increases. 



ii. The increase of the acidity is probably due to the production of amido-acids through or by the 

 trypanosomes. 



iii. It is possible that the increase of acidity might be of assistance in the diagnosis of a typical ease of 

 trypanosomiasis, where the parasites have disappeared for some length of time from the blood circulation. 



iv. These experiments suggest that in trypanosome treatment effort should be made to neutralise the increased 

 acidity of the blood, as this might prove of additional assistance in making the blood a less favourable medium 

 for their development. 



Laveran and Thiroux- discuss the role of the spleen in trypanosomiasis, and conclude : — ■ 



1. That when observations are made under good conditions the trypanosomes found in the spleen during life 

 or immediately after death xjresent the same appearance as those encountered in the general circulation. 



2. Splenic extract has no trypauolytic properties in vitro. 



3. In animals on whom splenectomy has been performed the evolution of trypanosomiasis is not sensibly 

 modified. 



4. In trypanosomiasis, as in malaria, the spleen doubtless contributes to free the circulation from the debris 

 of haematozoa following the trypanolytic crises, but its rOle seems limited to this function. 



This leads one to speak of the causes of trypanolytic crises and the relapses that follow 

 them. Massaglia^* 



worked with guinea pigs infected with surra, which presented, during the evolution of the malady, a certain 

 number of disappearances of the trypanosomes, followed by renewed proliferation. He first established that, 

 although normal guinea pig serum has but slight action on the trypanosomes of mice, that of infected guinea pigs 

 has marked trypanolytic power if taken just before the crisis, and acts very powerfully during or after the crisis. 

 If these sera are put up to the trypanosomes of guinea pigs, the result is but little less intense if the parasites be 

 taken just before the crisis, but they prove almost refractory after it. Heating for fifteen minutes to 65° C. 

 entirely destroys the trypanolytic power of the serum. 



In vivo guinea pig serum taken during the crisis has no curative action and but little preventive power. 

 Eodet and Vallet** took the blood of a dog with experimental nagana daily from the 

 date of infection to that of death, defibrinated and centrifuged it, and then put it up to rat 

 trypanosomes taken at the beginning of infection. At the outset the trypanolytic power of 

 the serum is nil, and only begins to appear two days before the first crisis, but during it and 

 after, it is very strong. The agglutinating power reaches its maximum immediately before 

 the crisis. Ttie dog's own trypanosomes proved less sensitive to the action of the serum 

 than those of rats. Heating even to 55° C. more or less destroys the power of the serum. 



From these data the authors conclude that the trypanolytic crises are due to the action 

 of the serum on the trypanosomes of the circulating blood, and are in no way a consequence 

 of the crises. 



Some papers on preventive and curative methods may be cited. Certain of Panse's^* 

 experiments in connection with immunisation against Nagana are interesting. He found the 

 Koch-Schilling's method of attenuation by passage through various species of animals 

 unsatisfactory on account of the persistence of trypanosomes in the immunised animals. 

 Injections of bile from infected animals made before, or simultaneously with, a virulent 

 inoculation brought about a mild attack, followed by considerable immunity, one of the 

 experimental oxen resisting five inoculations with a very virulent virus. Two oxen treated 

 preventively for four months with injections of blood containing dead trypanosomes were 

 also found to be immune. Out of two animals treated with a mixture of blood and bile, 

 one died after six months on inoculation with the virus, while the other was found to be 

 immune. 



Lastly, the author tested the protective value of the serum of the immunised animals. 

 When mixed with trypanosomes it produced a mild attack in one dog out of several 



* Nierenstein, M. (July 1st, 1907), " Observations on the Acidity and Alkalinity of the Blood in Trypanosome 

 Infections." Annals of Tropical Medicine and Parasitology, Series T. M., Vol. II., No. 3. 



^ Laveran, A., and Thiroux, A. (August 2oth, 1907), " Sur le r61e de la rate dans les Trypanosomiases." Ann. de 

 Vlnntitul Pastetir, Vol. XXI. 



" Massaglia, A., "The causes of Trypanolitic Crises, and the Relapses that follow them." C. li. Acad. Sc, 

 t. CXLIV. Quoted in Journal of 7'ropical Medicine and Hygiene, May 1st, 1908. 



" Rodet, A., and Vallet, Q. Ibid. 



'• Panse, — , " Attempts at Immunisation against Nagana in German East Africa." Deutxeh Colonialblatt, 

 No. 7, p. 8. Quoted in Journal of Tropical Medicine and Hygiene, April 15th, 1908. 



* Article not consulted in the original. 



