Pulmonary paragonimiasis is one of the most important endemic parasitic disease in Korea. Although it is well known that Paragonimus westermani invades into the lung tissue eventually resulting respiratory failure, the pathogenesis of inducing lung lesions is not fully elucidated. It is still debatable on the nature of morphological component of 'cyst' which is known to be the most consistent change in lung paragonimiasis. For the purpose of clarification of morphological changes associated with pulmonary paragonimiasis, an experimental study was carried out by giving metacercariae of P. westermani to 10 dogs. These dogs were sacrificed 2 months and 6 months after infection respectively, and light microscopic and electron microscopic observations were made. Following conclusions were obtained. Paragonimus lung lesions could basically be classified into two categories, i.e., direct mechanical effects by the worms and eggs, and the changes secondary to the worm infection. The relative importance of these two appeared almost same. Adult worms of P. westermani reside inside the lumina of the dilated bronchi in great majority of the cases. Only exceptions were secondary abscess formation and subsequent scar where no epithelial lining was detected around the worms. In 6 months group almost all P. westermani worms were found inside the bronchial lumina. Obliterative endobronchiolitis was another prominent feature among changes that were not directly associated with worms or eggs. This finding was more prominent in the distal segments of the bronchial trees that harbor the Paragonimus worms. P. westermani eggs were found as isolated and aggregated fashions, provoking characteristic granulomatous inflammation. Some of the egg granulomas were seen in the areas apart from the locations where the worms were physically located. Ultrastructural observations of the cyst wall showed fair numbers of plasma cells and mast cells. Some of the cystlining epithelial cells showed increased deposit of glycogen granules, suggestive of early metabolic alteration of the respiratory epithelium.
parasitology-helminth-trematoda ; Paragonimus westermani ; paragonimiasis ; dog ; lung ; histology ; pathology ; egg granuloma ; plasma cell ; glycogen

In order to understand the effect of prednisolone injection on the histopathological changes of the mouse liver and the chronological changes of the worm structure of Clonorchis sinensis, when this fluke was inoculated to the mouse intraperitoneally. The recovery rate, survival rate, location and size of the inoculated worms as well as the histopathological changes of the liver were investigated for the comparison among the groups of mice, which were classified by number of worms and the duration of observation period. The result obtained were summarized as follows: The recovery rate and survival rate of the worms decreased especially 28 days after the inoculation. Most of worms (45.5 percent) were collected from the peritoneal cavity, and some of worms were found tightly adherent to the capsules of the liver, spleen, intestine and diaphragm. The mean worm size after inoculation was constantly smaller than that before inoculation. Remarkable atrophy in the reproductive organs of the worm, such as spermatheca, testes, vitelline gland and ovary was frequently observed at the 10th day of inoculation. Histopathologically the liver failed to show any parasitic worm inside the intrahepatic biliary system. However, multiple well formed egg-containing granulomas were present along the liver capsule. These necrotic granulomas were occasionally found under the fibrotic liver capsule. Focal necrosis and focal phlebitis together with vascular dilatation were prominent features of the liver. The worms recovered in the capsule of the liver were degenerated and necrotized. Usually, there were remarkable capsulitis and granuloma formation around the eggs.
parasitology-helminth-trematoda ; Clonorchis sinensis ; histology ; pathology ; mouse-liver ; immunology ; immunesuppression ; necrosis ; phlebitis ; dilatation ; capsulitis ; granuloma

In order to understand the tissue responses of albino rat host against Paragonimus iloktsuenensis infection, the histopathological changes of the spleen and the lungs in 6 experimental groups of rats were observed in relation with the growth, maturation and migration of this lung fluke. Rats of the experimental groups, each group consisted of 5 rats, were infected with the metacercariae of P. iloktsuenensis which were isolated from brackish water crab, Sesarma dehaani, and were kept for 3 days, 3 weeks, 4 weeks, 7 weeks, 10 weeks and 14 weeks of infection period. Peripheral blood smear slides for the differential leukocyte count were prepared and also worm collection was completed immediately after the infection period. Paraffin sections of the spleen and the lung tissue were stained with hematoxylin-eosin and methyl-green-pyronin (MGP) stain. Those materials from the experimental groups were examined in comparison with the materials obtained from control group, with special reference to immunologic aspects of host response. The results obtained were as follows: The counts of large pyroninophilic cell (LPC) in the periarterial sheath of spleen were rapidly increased in earlier period of infection, and those of peribronchial lymphatic tissue started to increase after the penetration of lungfluke into the lungs. The LPC counts of both the spleen and the lungs were on the decrease in conjunction with the necrosis of the lung fluke in 14th week of infection. On observing differential leukocyte count of peripheral blood smear, the fluctuation of lymphocyte count was proportional to that of LPC count, and the lymphocyte count was consistently higher than that of normal rats. On the other hand, neutrophil count of experimental group showed reciprocal relation to the LPC counts. The nature and characteristics of pulmonary lesion produced by the P. iloktsuenensis were just the same as those produced by P. westermani. The lesions were represented by thick and fibrosclerotic cavern, granuloma due to eggs, pneumonic process and cellular infiltrations.
parasitology-helminth-trematoda ; paragonimiasis ; Paragonimus iloktsuenensis ; histology ; pathology ; lung ; spleen ; granuloma ; pneumonia ; hematoxylin-eosin ; methyl-green-pyronin

The technique of stem cells or hepatocytes transplantation has recently improved in order to bridge the time before whole-organ liver transplantation. In the present study, unfractionated bone marrow stem cells (BMSCs) were harvested from the tibial and femoral marrow compartments of male mice, which were cultured in Dulbecco's modified Eagle's medium (DMEM) with and without hepatocyte growth factor (HGF), and then transplanted into Schistosoma mansoni-infected female mice on their 8th week post-infection. Mice were sacrificed monthly until the third month of bone marrow transplantation, serum was collected, and albumin concentration, ALT, AST, and alkaline phosphatase (ALP) activities were assayed. On the other hand, immunohistopathological and immunohistochemical changes of granuloma size and number, collagen content, and cells expressing OV-6 were detected for identification of liver fibrosis. BMSCs were shown to differentiate into hepatocyte-like cells. Serum ALT, AST, and ALP were markedly reduced in the group of mice treated with BMSCs than in the untreated control group. Also, granuloma showed a marked decrease in size and number as compared to the BMSCs untreated group. Collagen content showed marked decrease after the third month of treatment with BMSCs. On the other hand, the expression of OV-6 increased detecting the presence of newly formed hepatocytes after BMSCs treatment. BMSCs with or without HGF infusion significantly enhanced hepatic regeneration in S. mansoni-induced fibrotic liver model and have pathologic and immunohistopathologic therapeutic effects. Also, this new therapeutic trend could generate new hepatocytes to improve the overall liver functions.
Alanine Transaminase/blood ; Alkaline Phosphatase/blood ; Animals ; Antigens, Differentiation/biosynthesis ; Aspartate Aminotransferases/blood ; Bone Marrow Cells/cytology ; *Bone Marrow Transplantation ; Cell Differentiation ; Cell- and Tissue-Based Therapy ; Cells, Cultured ; Collagen/metabolism ; Female ; Granuloma/parasitology/pathology ; Hepatocyte Growth Factor/pharmacology ; Hepatocytes/*cytology ; Liver/parasitology/pathology ; Liver Cirrhosis/parasitology/pathology/*therapy ; Male ; Mice ; Mice, Inbred BALB C ; Schistosoma mansoni/pathogenicity ; Schistosomiasis mansoni/mortality/*therapy ; *Stem Cell Transplantation ; Stem Cells/cytology