• Parasites, Hosts and Diseases
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• v.32 no.2
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• pp.117-120
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• 1994

Two rare cases of human infection with parvum (dwarf) type of Diphyllobothnum Iatum [syn. D. panpum (Stephens, 1908)], were discovered in Korea. The first case was a 46-year old housewife, from whom a kind of pseudophyllidean tapeworm eggs was detected in the feces. She was treated with praziquantel and purged, and a complete strobila with scolex, 120 cm in total length, was recovered. She recalled that she had eaten raw trouts at a raw-fish restaurant near the Chungju Lake. Another patient was a 22-year old medical student (male), who used to eat raw sea-foods. He discovered a chain of tapeworm proglottids, 15 cm in length, discharged spontaneously in his stool and brought it for identification. The worms from the two cases were compatible with D. pan)urn (Stephens, 1908) of which the taxonomic significance has long been questioned. After a detailed morphological study and review of literature, we designated the worms as D. datum prom type. This is the first report on the occurrence of this rare type of D. lotunl infection in Korea.

• Parasites, Hosts and Diseases
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• v.27 no.3
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• pp.213-216
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• 1989

Seven cases of Diphyllcbothrium latum infection were proved by collection of worms after prasiquantel treatment between October, 1986 and July, 1987. The patients were all males aged 20~44 years residing in Seoul or Ulungdo, Kyungpook Province. All of them had the history of eating several kinds of raw marine fishes, and they had never been to abroad. One of them exporienced abdominal pain and 6 experienced natural discharge of a chain of worm segments, but none revealed any sign of anemia, Total 12 worms (1~3/patient) were collected after praiiquantel treatment. The worms were 85~423 cm in length, and revealed the characteristic rosette-shape uterus in their gravid proglottides. The average egg size varied $61.0~65.3{\times}41.7~46.1{\;}{\mu\textrm{m}}$. The eggs were yellowish. brown, and ovoid to elliptical. Including the present 7 cases, the total number of human D. latum infections proven by worms in Korea becomes 28 cases.

• Parasites, Hosts and Diseases
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• v.32 no.3
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• pp.149-156
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• 1994

An epidemiological study fur the Intestinal trematode infection of the villagers was done In Koje-myon, Kochang-gun, Kyongsangnam-do, Korea in March, 1994. Of 116 stool specimens examined, total helmlnthic ova positive cases were 13 (11.2%) and cumulative ova positive cases 21 (18.1%): Echinostoma hortense 11 cases (9.5%), Metngonimus sp. 6 cases (5.2%), and Clonorchis sinensis 4 cases (3.4%). After the treatment and purgation, variable numbers of E. hokene, 6 to 227 per person, were collected from 7 echlnostome egg Positive cases, together with M. tokohoshii In 6 cases. Three adult flukes of E. cinetorchis were collected from one person and one Stellantchasmw jnlcatus was recovered from another case. This mountainous village was proved to be one of the endemic foci of echlnostomlasis In Korea.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.55-58
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• 1998

A small-scale epidemiological survey was undertaken on the residents along the Mekong River near Pakse, Laos, to know the status of helminthic infections. A total of 137 fecal samples were collected from the staffs of the provincial government, their family, and primary schoolchildren in Pakse City, Champassak Province, and examined by Kato- katz smear technique. The overall helminth positive rate was 75.9%, and the helminths detected were Opisthorchis viuerrini (43.8%), Asccris lumbricoines (26.3%), fichuris trichiurn (19.0%), hookworms (19.0%), Strongyle컸os stercoraLis (2.2%), Taenio sp. (0.7%), and Schistosoma mekongi (1.5%). To obtain the adult worm of the liver fluke, three infected persons were treated with praziquantel and purged with magnesium sulfate. Five, 10, and 395 adult flukes, respectively, were collected from their diarrheic stools, all of which were morphologically identified as 0. viueni,ni. The results represent that the liver fluke and soil-transmitted helminths are highly prevalent, and the life cycle of 5. mekowi is likely to be maintained in this area.

• Parasites, Hosts and Diseases
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• v.32 no.3
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• pp.157-162
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• 1994

A highly endemic focus of human infection with Heterophves nocens (Heterophyidae) was discovered from a small coastal village of Shinan-gun, Chollanam-do, for the first time in Korea. Fecal examinations by cellophane thick smear and formalin- ether sedimentation techniques revealed 42.9% heterophyid egg Positive rate out of 98 inhabitants examined. It was difficult to confirm the species of heterophylds only by eggs. In order to collect the adult flukes, the egg Positive cases were treated with 10 mg/kg single dose of praziquantel and purged with magnesium sulfate, and the adult worms were collected from the diarrheic stools. From each of 18 cooperative patients 1 to 1,124 (total 4,730) H. nocens worms were recovered, together with a few to large numbers of heterophyids (Pvginiopsis summa, Stictonora juscatunl and for gymnophallids (Gvmopholloides stool) . It is speculated that H. nocen might be widely distributed along the southwestern coastal areas where the brackish water fish such as the mullets or gobies are popularly eaten raw.

• Parasites, Hosts and Diseases
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• v.27 no.2
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• pp.119-130
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• 1989

An experimental pathological study was performed to observe the effect of prasiquantel treat- ment on the pulmonary lesions of the rat lung cuke, Paragonimus ilektsuenensis. The metacercariae were obtained from the freshwater crab, Sesarma dehaani, and 40 rats (wistar) were fed each with 10 metacercariae. On 20 rats prasiquantel treatment ($100mg/kg/day{\times}5$ days) was done at 5 weeks after the infection while remaining 20 rats were kept untreated for use as controls. The drug.treated rats and the untreated ones were sacrificed 3, 7, 14, 21 or 28 days later for the observation of lung pathology. The rats infected with P. iloktsuenensis showed remarkable pulmonary changes; gross features of hemorrhagic and nodular worm capsules protruded on to the surface of the lung, and histologically local atelectasis, inflammatory cell infiltration, and egg granuloma around the worm capsules each containing one or two worms. Praziquantel treatment of the rats was shorn to be highly effective in killing the worms and to lead them to degenerate, as early as in 3 days post-treatment. Almost all worms in the lung were dead and absorbed by the host cells in 21 days post-treatment, except a few living ones seen in a rat of 14-day post-treatment group. In most of the rats treated the pulmonary lesions showed the signs of resolution; regression of worm capsules with mummification of worms, decrease of inflammatory cell infiltration, improvement in the degree of atelectasis, and decreases in the frequency and size of the egg granuloma. From the results it is concluded that prasiquantel is highly effective for the treatment of rat P. iloktsuenensis infection in the lung, not only by its direct killing effect of the worms but also due to the excellent resolution capacity of the pulmonary tissues.

• Parasites, Hosts and Diseases
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• v.32 no.4
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• pp.223-230
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• 1994

Clonorchiasis is an important parasitic disease of humans in Korea. The present study intended to compare sonographic findings with histopathological changes in experimental clonorchiasis. Eighteen New Zealand white rabbits were infected with metacercariae of Cknorchis sinensis, and examined 4, 10, and 22 weeks post-infection (PI). Four infected rabbits were treated with praziquantel 10 weeks PI and were examined 12 weeks after treatment. Sonography revealed mild to severe dilatation of the intrahepatic ducts (IHDD) and slightly increased periductal echoes in 12 out of 14 rabbits at 4 weeks PI, and all of the animals after 10 and 22 weeks PI and 12 weeks after treatment. The histopathological lesions were duct dilatation, mucosal hyperplasia, and periductal fibrosis, which progressed from 4 weeks to 22 weeks PI and even in treated rabbits. The dilated intrahepatic ducts over 1 mm diameter were detected by sonography. The present results indicate that sonographic findings are well correlated with histopathological lesions in rabbit clonorchiasis except for early phase of light burden of infection. The sonography has a limitation in discriminating residual sequelae of the ducts after praziquantel treatment.

• Parasites, Hosts and Diseases
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• v.27 no.1
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• pp.35-40
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• 1989

It is well known that the duodenum of mice or rats infected with Fibricoln seoulensis shows atrophy of villi (shortening, blunting, widening, fusion) and hyperplasia of crypts. This study was performed to observe healing process of .these pathological changes after deworming with anthelmintic treatment. Albino rats infected each with.1,000 metacercariae of F. seeulensis were treated with single dose of 10 mg/kg praziquantel on day 15 post·infection. On day 1, 3, 5, 7, 15, 21 and 28 after the treatment, they were sacrificed and their duodenums were histopathologically studied. Control (uninfected) rats showed their normal finger-like projections of duodenal villi and well arranged crypts. In comparison, untreated (infected) contiols revealed severe mucosal changes characteristic of villous atrophy and crypt hyperplasia in their duodenum. The damaged duodenal mucosa was found to restore its normal morphology after praziquantel treatment; until day 3 post-treatment the mucosa was severely atrophied; on day 5 long and slender villi sometimes appeared among the fused and stout ones; after day 15 the villi were in their normalising process. From this experiment, it was shown that the mucosal changes in the duodenum of rats caused by F. seoulensis infection were completely reversible in 21∼28 days after anthelmintic treatment.

• Parasites, Hosts and Diseases
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• v.27 no.1
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• pp.15-22
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• 1989

To observe antibody changes after praziquantel treatment in paragonimiasis, a total of 46 serum samples from 13 serologically diagnosed patients was collected for 4~28 months. The specific antibody (IgG) levels were measured by enzyme- linked immunosorbent assay (ELISA). All but one patient who needed retreatment became symptom-free within a week. Antibody levels were dropped near to or below a cut-off absorbance (abs.) of 0.25 in varying intervals from 4 to 18 months. Of 9 patients who were retested within 3 months, 5 revealed temporary elevation of antibody level. After the elevation, the levels be낙an to decline slowly to negative ranges. If treated earlier after symptoms developed, the temporary elevation did not occur and intervals to negative conversion were shorter. By sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) /immunoblot, antigen-antibody reactions in individual patient faded gradually without significant changes in reacting antigen bands.

• Parasites, Hosts and Diseases
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• v.33 no.1
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• pp.37-44
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• 1995

Neodiplostomum seoulensis, one of the human intestinal trematodes , was reinfected to albino rats, and worm recovery rates, histopathology and activity changes of the intestinal brush border membrane bound enzymes were observed. The experimental groups were three: uninfected, primary infection and reinfection. The worm recovery rate in the reinfection group was much lower than in the primary infection group 14 days after infection. The duodenal histopathology showed villous atrophy during the first and second week in the primary infection group. In the reinfection group, however. villous changes occurred as early as 3 days after the infection, and the lesion was found healed 7 days after infection. The activities of alkaline phosphatase and sucrase in the duodenum of primary infection rats decreased nearly half of the controls 2 weeks after infection, whereas the activities were unchanged in the reinfection group. However, no changes in the activities were observed in the proximal jejunum between the experimental groups. These findings suggested that a secondary infection of N. seouLensis in rats should make less damage on the intestinal mucosa than a primary infection. Key words: Neoniplostomum seoulensis, albino rats, reinfection, worm recovery, histopathology, brush border membrane bound enxyines.