gQO Trypanosomo Diseases. 



anemia as well as emaciatiou, with usually a good appetite. 

 Nervous functional disturbances, especially peripheric paraly- 

 ses, are also frequently observed. Death is usually preceded 

 by a comatose condition. 



Treatment. While in former years the trypanosome affec- 

 tions have been treated mainly Avitli quinine, corrosive subli- 

 mate and iodine preparations, although without apparent re- 

 , suits, Lingard obtained in surra, and Bruce in nagana, note- 

 ! worthy results with arsenious acid, inasmuch as with this treat- 

 I ment "the nundjer of the blood parasites was sometimes reduced 

 ' very markedly. The improvement was however usually only 

 temporary, as*^ after a certain time the trypanosomes reappear 

 in the blood, so that the final results, at best, showed only a 

 prolongation of the course of the disease. 



More recent investigations, above all the great laboratory 

 experiments of Ehrlich and his school, show that certain 

 chemical substances have a specific destructive action on 

 trypanosomes in the infected animal bodies, or at least exert 

 an inhibitive action on their development, and in suitable ap- 

 plication may even result in permanent recovery from the 

 disease. Such substances, excluding some of the basic triphenyl- 

 methan dyes (parafuchsin, methylviolet, pyronin), are certain 

 azofar stains, such as the trypan red, the trypan blue, the 

 trypan rosan, and the trypan violet, certain arsenical deriva- 

 tives, especially atoxyl, arsazetin, the arsenophenyglyzin, and 

 the dioxydiamidoarsenobenzol (Ehrlich-Hata 606), also some 

 antimony preparations, such as tartar emetic. 



Special study was given to atoxyl (sodium arsanilate) first recom- 

 mended by Thomas and Breinl, and Mesnil & Nicolle. It was found 

 that this remedy, different from the basic stains mentioned, which are 

 effective even in test-tube experiments, does not even in concentrated 

 solution aft'ect the trypanosomes harmfully in vitro, while in the animal 

 body it causes the disappearance of the parasite even in a dilution of 

 1 :120000. Ehrlich believes that the action of the atoxyl in vivo is due 

 to the fact that the substance is reduced to paraaminophenylarsenoxyd, 

 which kills the trypanosomes also in the test tubes, even in dilutions of 

 1 rlOOOOOO. This is corroborated by the experimental results of Levaditi, 

 Yamanouchi & Brimont, as these authors have found that the atoxyl 

 is reduced in the animal body (to a hypothetical trypanotoxyl) ; al- 

 though later they supposed that the reduction product in such a reduced 

 condition, combines with proteid molecules, to form a toxic arsentox- 

 albumin. 



Breinl & Nierenstein however believe that the atoxyl combines with 

 the serum proteids, whereupon arsenic is set free through oxydation 

 of the atoxyl in the serum, and this, in statu nasccncli exerts a de- 

 structive influence on the parasites. The correctness of this conception 

 appears to be substantiated by the experimental results of Loeffler, who 

 obtained the best and most lasting recoveries in nagana-guinea pigs 

 and cats from the administration of atoxyl, together with arsenious acid 

 in subtoxic doses (3-5 mg. arsenic per os., and 315 eg. atoxyl subcutan 



