Muneo Yokogawa

The route of migration of the larva of Paragonimus westermani in the final hosts.

The course of infection and migration of Paragonimus westermani was studied in cats and rats with the Evans-blue technique to make it easier to find the lesions and recover the worms. The cats were divided into two groups, one under and one over 350 g. Cats were given 50 metacercariae each and rats 20. Cats were sacrificed and examined periodically from a half hour to 14 days after infection; rats from one-half hour to 180 days. From 40% to 60% of the worms fed were recovered at each examination. Worms penetrate the intestinal wall within 30 to 60 min after feeding, and reach the abdominal cavity in from 3 to 6 hr. The worms then penetrate the abdominal wall, whence, after having made some growth, they re-enter the abdominal cavity in from 6 to 10 days, and migrate through the diaphragm to the pleural cavity and lungs. The period of residence in the body wall coincides with that when earlier workers were unable to find the worm. The pattern of migration and development differs somewhat in cats above and below 350 g, and in rats. The rat is an unfavorable host and will not support maturity of the parasite, although many of the worms wander in its tissues indefinitely. S. Yokogawa (1915, 1916, 1919, 1921) was the first to point out the route of migration to the lungs of larvae of Paragonimus westermani after penetration of the intestinal wall of the final host. This route was accepted by Nakagawa (1915a, b) and Ando (1915). According to Yokogawa the metacercaria given orally excysts in the upper or middle parts of the small intestine, penetrates the intestinal wall, wanders about in the abdominal cavity for about 2 weeks, and then migrates upwards through the diaphragm to the pleural cavity. It finally arrives in the lungs where it settles down and forms its worm cyst. Sixty to 70 days after infection the larva reaches maturity in the worm cyst. S. Yokogawa and Ando fed metacercariae to experimental animals and tried to follow the course of migration by collecting the worms from the intestinal wall, abdominal and pleural cavities, and various organs. Few worms were recovered during the Received for publication 24 April 1961. * The research reported in this document has been made possible through the support and sponsorship of the U. S. Department of Army through its Far East Research Office, and also was supported in part by a Scientific Research Grant from the Ministry of Education in Japan. t The material covered in this paper has already been published in Japanese journals in Japanese (Yokogawa, 1960; Yokogawa and coworkers, 1958, 1959a, b). period from the 1st day to the 2nd week after infection, a difficulty that previous investigators attributed to the small size of the young

Schistosoma japonicum: immunopathology of nephritis in Macaca fascicularis.

Abstract Macaca monkeys experimentally infected with Schistosoma japonicum developed a chronic progressive kidney lesion characterized by an increase of mesangial matrix, local glomerular hypercellularity, and local thickening of glomerular basement membrane. Immunofluorescence studies revealed the localization of IgG, IgM, IgA, and IgE immunoglobulins mostly in the mesangial area of the glomeruli accompanied by the deposition of Schistosoma antigens. By electron microscopy, in addition to the local thickening of the glomerular basement membrane, dense homogeneous deposits and those with moth-eaten appearance were detected in the mesangial matrix. These findings suggest that worms in the bloodstream continuously release antigenic materials that stimulate hosts antibody response belonging to various immunoglobulin classes including IgE. The produced antibodies and antigens would form immune complexes that deposited in the glomeruli. The increased vascular permeability caused by antigen-IgE antibody interaction may play an important role in the deposition of immune complexes and in the rapid development of kidney injury.

Production and properties of reaginic antibodies in rabbits infected with Clonorchis sinensis or Schistosoma japonicum

Abstract The production of reaginic antibodies detected by homologous passive cutaneous anaphylaxis (PCA) was demonstrated in all rabbits experimentally infected with either Clonorchis sinensis or Schistosoma japonicum . The antibodies appeared in the sera as early as 3 weeks after exposure and persisted with relatively high titers for at least 7 weeks in some animals. The antisera of rabbits infected with C. sinensis were found to be cross reactive against heterologous trematode antigens, although PCA titers were less than 3% of the titer by the homologous antigen; no cross reaction was observed between S. japonicum antiserum and the heterologous antigens. PCA activity of the antisera was completely destroyed in some samples by heat treatment at 56 C for 2 hr, but partially in the others even after heating for 6 hr. However, the physicochemical properties of these antibodies were analogous to human IgE; the PCA activity was eluted with 0.035 M phosphate buffer from a DEAE-cellulose column and recovered in the ascending portion of the IgG peak by Sephadex G-200 gel filtration. PCA activity was found in a β region in preparative agar electrophoresis.

Paragonimus westermani: A comparative study on the migration route of the diploid and triploid types in the final hosts

Recent studies on chromosomes have shown the presence of diploid and triploid types of Paragonimus westermani. To determine any possible biological differences between them, the migration route and development of the diploid type in the final hosts were compared with those of the triploid type. In the cat, the definitive host, larvae of the diploid type migrated to the abdominal wall, remained there for two weeks, and then migrated to the lung. In the rat, the abnormal host, some orally administered metacercariae of the diploid type made cysts in the lung and laid eggs, but the triploid type did not lay any eggs. Neither type of P. westermani migrated to the liver of the rat, in contrast to the previously reported fact that P. miyazakii and P. ohirai migrate to the liver and develop there. From these results, it seems likely that the two types of P. westermani are closely related.

Terrestrial turbellarians (Tricladida: Bipaliidae) as pseudoparasites of man.

A living terrestrial planarian, Bipalium fuscatum, was coughed up by a child in Chiba Prefecture, Japan. Severe coughing and respiratory difficulties during the preceding 4 days suggest the worm had been present in the respiratory tract for that period. A related species, B. venosum, had previously been reported by a Japanese physician in Kyushu to have been passed during defecation by a woman hospitalized for rectal bleeding. No explanation is available as to how the worms were acquired. In Atlanta, Georgia, a B. kewense was encountered in the diaper of an infant, which appeared to have been passed with the stool. These cases suggest that these free-living flatworms will invade body openings and can survive for some days as pseudoparasites. Standard texts on parasitology treat only two of the classes of the Phylum Platyhelminthes, the Trematoda and Cestoda. The third class, the Turbellaria, comprising primarily free-living forms, has been almost entirely ignored by medical parasitologists and physicians. The terrestrial turbellarians are nocturnal predators in humid environments. This report describes our experiences, and that of a colleague in Kyushu, Japan, which have led us to believe that several species of one widely distributed genus of terrestrial planarians can be pseudoparasites and possibly produce lesions in

Schistosoma japonicum and Paragonimus ohirai: antagonism between S. japonicum and P. ohirai in Oncomelania nosophora

Antagonistic interactions between Schistosoma japonicum and Paragonimus ohirai were examined in the snail host, Oncomelania nosophora. When P. ohirai-infected snails were exposed to S. japonicum miracidia at intervals of 4 to 18 weeks post-first exposure, only a few snails (0-7%) were found to be superinfected with S. japonicum sporocysts. Sporocysts were fewer in number than those of single infected controls. Mature S. japonicum cercariae were not observed. Furthermore, when the snails were examined at intervals of 14 to 18 weeks post-second exposure, neither sporocysts nor cercariae of S. japonicum were found. On the other hand, when the snails were exposed to miracidia of S. japonicum and P. ohirai simultaneously, they were easily infected with both parasites. At 26 weeks after simultaneous exposure, however, the infection rate of S. japonicum was significantly lower than that of controls. In contrast, when S. japonicum-infected snails were exposed to P. ohirai miracidia, they were superinfected with P. ohirai, although the infection rate was somewhat lower than that of controls. These results indicate the existence of antagonism between S. japonicum and P. ohirai in O. nosophora. Furthermore, P. ohirai was dominant over S. japonicum in the antagonistic interactions in this snail host.

Application of the latex agglutination test for human paragonimiasis in South America

The latex agglutination test (LAT) was compared with the complement fixation test (CFT), double diffusion test (DDT) and enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of South American paragonimiasis. Sera from 17 Peruvian and Ecuadorian patients with paragonimiasis, from 15 Japanese patients with other helminthiases, and from 100 healthy students were analyzed. The tests were also compared using serum samples from patients treated with bithionol. There was remarkable agreement among the methods and it was concluded that the LAT could be a useful serodiagnostic technique for paragonimiasis, especially in field surveys.