In order to understand the effect of prednisolone injection on the immune responses of albino rat against Paragonimus iloktsuenensis infection, the differential leucocyte counts, appearance of immunoblast (large pyroninophilic cell, LPC) in the spleen and lungs in various experimental groups were observed in relation with the growth, maturation and migration sites of this rodent lungfluke. Rats of 3 experimental groups (A series), each group consisted of 5 rats, were infected with 20 metacercariae of P. iloktsuenensis, and they were kept for 3 days(Group I), 3 weeks(Group II), and 4 weeks (Group III) of infection period. The same number of experimental groups, each group of rats received 10 mg/kg dose of prednisolone injection every other day, were also kept and examined in comparison with the former groups. Preparation of peripheral blood smear and collection of worms were completed immediately after the end of infection period, and they were stained with Giemsa or Semichon's acetocarmine. Paraffin sections of the spleen and the lung tissues were stained with hematoxylin-eosin and methyl green pyronin (MGP). Those materials from A and B series of experimental groups were examined under the light microscope, and the results obtained were as follows: On observing differential leucocyte counts of peripheral blood smear, lymphocyte counts were consistently higher than those of uninfected controls in A series of infected groups, while those of B series were consistently low. On the other hand, neutrophil counts of A series showed lower counts than those of B series. In general, fluctuation patterns of both A and B series of experimental groups were almost the same, although lymphocyte and neutrophil counts showed reciprocal relation. The eosinophil counts of both series were negligible, especially in the groups of B series. The counts of LPC in the periarterial lymphatic sheath of the spleen were rapidly increased in the groups of A series, while those of B series were much less than those of A series, and the appearance of considerable LPC in the spleen was also delayed in B series. Furthermore, LPC of peribronchial lymphatic tissue in A series started to increase after the invasion of lungflukes into the lungs, while those of B series were much less due to the inhibited migration of lymphocytes into the lesions. Number, size and maturity of collected worms showed no significant differences between the groups of A and B series, but migration speed of the lungflukes was somewhat accelerated in B series than in A series. In this connection, it was considered that the immune responses of albino rats did not contribute for the complete protection against P. iloktsuenensis, but inhibited the migration of this lungfluke to some extent.
parasitology-helminth-trematoda ; Paragonimus iloktsuenensis ; paragonimiasis ; immunology ; prednisolone

The new drug niclofolan (bayer 9015, Bilevon), 5,5'-dichloro-2,2'-dihydroxy-3, 3'-dinitrobiphenyl, has been used in the treatment of Paragonimus westermani in dogs and cats and P. iloktsuenensis in rats. It was proved that administration of daily dose of 1.0 mg/kg body weight for 3 days or in 2 doses of 2.0 mg/kg body weight by alternate days were evidently effective for the infected dogs, cats and rats with the lung flukes, and toxic manifestations were not found.
parasitology-helminth-trematoda ; Paragonimus iloktsuenensis ; paragonimiasis ; Paragonimus westermani ; dog ; cat ; rat ; niclofolan-chemotherapy ; niclofolan

Mathematical models such as the negative binomial, Poisson and Polya-Eggenberger distributions were applied to the observed data of the number of metacercariae of Paragonimus iloktsuenensis in crab hosts, Sesarma dehaani which were collected in Hadong, South Kyong-sang Do, Korea. From the above analysis, it was found that the pattern of density of metacercariae of this lungfluke among the crab hosts was well fitted to the negative binomial distribution, rather than to the Poisson or Polya-Eggenberger distribution.
parasitology-helminth-trematode ; Paragonimus iloktsuenensis ; epidemiology ; mathematics ; metacercaria ; crab ; Sesarma dehaani

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