Echinostoma cinetorchisの病原性に関する実験的研究

Echinostoma cinetorchisの肝内異所寄生に就て

抄録

In the previous paper the author reported the pathological studies on the animals affected by Echinostoma cinetorchis with some endemiological observations presenting the fundamental knowledge on the pathogenicity of this worm. The purpose of this paper is to reveal the mechanism of heterotopic parasitism of this worm and pathologic changes in the liver which have been found unexpectedly on the two cases of affected animals as introduced briefly in the previous paper. The experiments revealed the mechanism of this curious heterotopic parasitism of this intestinal parasitic trematoda, i.e. 1. Repeated feeding of metacercaria proved that this worm acutually can invide into the liver (passing through the common bile ducts) and grow in the intrahepatic ducts. 2. The feeding test proved that the worms invide more frequently into the liver of starved animals than of those of normally nurished, indicating the starvation gave a better condition for the invasion into the liver. 3. On the other hand, the massive parasitism in intestine also caused frequent intrahepatic invasion, though the massive feeding of metacercaria not always resulted in the massive intestinal parasitism.
The pathologic changes seen on the attacked liver are summarized as follows. 1. The defect or desquamation of the epithelium of the bile ducts surrounding the worm body, which will be the results of mechanic injury given by the parasite. 2. Generallized cholangitis and pericholangitis which would be induced by the mechanic injury followed by bacterial infection. This was accompanied by the inflammatory changes of the parenchym and the vessels of pfortal system. 3. Focal necrosis of the liver cells caused by the secoundery induced disturbances of circulatory system which developed to the purulent foci elswhere. 4. Exsudative and proliferative inflammation on the tissues surrounding the eggs of the worm.