1014 Bacterial Pyeloiicplnitis. 



being necessary that the umbilicus is primarily diseased. The 

 fact that male or young animals are also affected without other 

 primary diseases has led Bang to suppose that the virus may 

 possibly be introduced by way of the digestive tract. Bollinger 

 considers also a cryptogenetic infection to be possible. This last 

 liypothesis receives some support by the experiments of Ficker 

 v.'hich showed that bacteria are absorbed by the uninjured 

 intestinal mucous membrane if the animals are subjected to 

 hunger or to excessive exertion. 



Concerning the mode of invasion of the bacteria into the 

 kidneys the views differ. Some authors insist upon a urogenic, 

 others upon a hematogenic origin of the disease. Aside from 

 Enderlen's experiments in rabbits, which have already been 

 mentioned and which were positive, the hematogenic invasion 

 of the bacteria is supported by some observations of Ernst, 

 in which the kidnej^s showed typical lesions while the urinary 

 passages were free from alterations or only the bladder con- 

 tained severe inflammatory lesions while the pelvis and ureters 

 were normal. Of like significance is the observation of Scherzer 

 where in a case of pyelonephritis the valves of the heart con- 

 tained deposits in which the Bac. pyogenes, which w^as present 

 in the kidneys, was found in pure culture. The above men- 

 tioned experiments of J. Koch afford further proofs (p. 1013) 

 and also those of Albarden, Savor and Orth which demonstrated 

 that bacilli of the colon group may produce the picture of 

 pyelonephritis by being eliminated in the kidneys. 



On the other hand the urogenic origin of pyelonephritis 

 cannot be denied for all cases, the more so as, according to 

 the experiments of Schmidt & Aschoft', Savor and v. Wiinsch- 

 heim, colon bacilli may lead to the development of pyelonephritis 

 on being introduced into the bladder. 



Evidently, however, the urogenic origin is rather rare. 

 It is always necessary to consider that the bacteria may enter 

 the blood vessels of the bladder and then reach the kidneys 

 by the blood paths after the bladder has become affected in 

 consequence of an artificial or a natural infection. This mode 

 of infection may be thought of, especially since the experiences 

 of human physicians in catheterization indicate that even super- 

 ficial epithelial defects in the mucous membrane of the bladder 

 may give rise to an absorption of bacteria into the circulation. 



Favoring circumstances appear to be important factors 

 for the origin of pyelonephritis. Aside from the frequent con- 

 nection of the disease with the birth act or with inflammatory 

 processes in the female genital organs, and possibly also in other 

 organs, a functional irritation of the kidneys may have a pre- 

 disposing effect, even after normal parturition, and still more 

 the elimination of septic substances in the above mentioned 

 organic diseases. The predisposing influence of urinary stasis 

 also deserves mention, whether it be due to pressure exerted 

 by the pregnant uterus, especially if the embryo is excessively 



