An experimental study on uptake of Cr(51) tagged red blood cells to Paragonimus westermani in definitive host

Authors carried out the experimental study to investigate whether the Paragonimus westermani would uptake the blood in the parasitic definitive host, and also tried for the amount and distribution of the blood which would be harbored in a worm body, and so on. Experimental animals used in this study were dogs and cats, and they were infected with metacercariae of P. westermani. Several months later of the infection, Cr(51) tagged red blood cells were administered to each animal, and the animals were sacrificed and autopsy was done after 24 or 48 hrs of the administration. One part of the detected P. westermani adult worms of each animal were bred in Tyrode's solution and the others were killed by fixing in formalin solution. By Well-type scintillation counter, the radioactivities were measured for the alive and killed worms and of the blood of each experimental animal which was collected at autopsy . In conclusion, it was found that P. westermani worms uptake blood in parasitic definitive host, and amount of the blood harboring in a worm of 56 infection-days(size of worm; 4 x 3 x 1 mm) was 0.002 ml, 0.004 or 0.005 ml in 103 infection-days(size of worm: 8 x 5 x 3 mm) and 0.011 ml in 217 infection-days(size of worm: 9 x 7 x 4 mm). Almost of the whole blood uptaked in the worms was distributed in intestine. It was observed that the blood uptaked in the worm body was excreted continuously through the excretory pore, so that the radioactivity could not measured almost completely in cases of 24 hrs-breeding worms.

A study on the chemotherapy in clonorchiasis. Report 3. The patho-histological study on the liver of rabbit healed from clonorchiasis by chemotherapy

In the experimental rabbits which were previously infected with Clonorchis sinensis and were thereafter administered with Dithiazanine iodide, the patho-histological and some histochemical changes were observed in the healed liver(76 days after stoppage of egg excretion). And also, the patho-histological changes which appeared in the infected and healed livers respectively were compared from each other. The following results and conclusion were obtained. In the infected group, grossly the liver showed a considerable increase of its weight, an increased vascular marking of its surfaces and an increase in consistency and thickness of the bile ducts. However, the healed group grossly showed no remarkable changes in the liver. In the infected group, microscopically the liver showed a marked adenomatous hyperplasia of bile ducts, proliferation of bile ductules and marked periductal and periductular fibrosis with infiltration of chronic inflammatory cells in portal spaces. A histochemical study showed that the increased fibrous tissue consists largely with collagenous fibers and partly with reticulum fibers. In the group with healed liver microscopically the liver showed much improvement in the histopathological changes compared to those of the infected group. In the healed lover there remained only slight histopathological changes mainly in portal spaces of the liver, such as considerably diminished periductal and periductular fibrosis. The slightly increased fibrous tissue consists largely with reticulum fibers and partly with collagen fibers.