E. histolytica: pathogenesis 



bach's plexus is recognized as the center for intestinal 

 peristalsis and its abnormal stimulation may be brought 

 about in various ways. In the case of amoebic diarrhea 

 the most probable stimulus is the irritation of the intes- 

 tinal wall. If mild, such irritation would result in an 

 increased production of mucus; if more severe, a more 

 copious transudation might ensue. The exact modus oper- 

 andi in this and other types of symptoms due to amoebic 

 invasion is, however, unknown, and hence it would be 

 fruitless to elaborate the subject further in this place. 

 The fact that the origin of symptoms in this and other 

 protozoan diseases is open to experimental study and 

 offers a fascinating field for investigation cannot be too 

 strongly emphasized. 



(2) Pathogenesis. As in the case of symptoma- 

 tology, the pathology of amoebiasis has been described 

 many times. Descriptions of the pathogenesis of amoe- 

 biasis are also available but these are based largely on 

 assumptions ; it is easy to imagine what might take place 

 but quite another thing to determine exactly the rela- 

 tions between the parasite and the host that result in 

 a diseased condition. Probably some of the newly hatched 

 amoebse succeed in reaching the wall of the large intes- 

 tine to which they attach themselves by means of their 

 pseudopodia, and thus escape being carried out of the 

 body. The presence of only a few specimens would inter- 

 fere extremely little with the functions of the intestinal 

 wall, but large numbers of amoebae might exert an effect 

 by simply decreasing the amount of epithelial surface in 

 contact with the intestinal contents. The combined effects 

 of large numbers of amoebae may thus become of suffi- 



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