No abstract available.
Paragonimiasis ; Paragonimus westermani ; Stroke

Metacercariae were found from 6 samples among 4,382 Parlemon nipponensis which were caught at Podu, Kohung, Korea. The metacercaria was inclined as a larval stage of Paragonimus westermani by following reason: Semisulcospira libertina was the only one species which lives in Podu area. No other metacercaria except Paragonimus westermani were found from the craw or cray fish which were caught in the endemic aera. Metacercariae, ovary, testes and cuticular spines resmbled the characteristics of Paragonimus westermani, which have been described by previous workers.
parasitology ; helminth ; trematoda ; Paragonimus westermani ; metacercaria ; epidemiology

The present study was performed to observe the ultrastructure of the integument of adult Paragonimus westermani. Dogs experimentally infected with 60 metacercariae of P. westermani were autopsied 4 months after the infection. Adult P. westermani were extracted from the dogs and the fine structure was studied by means of scanning and transmission electron microscope. The findings are as follows: Scanning electron microscopic findings showed that the spines and the papillae are distributed at whole body surface but the well developed spines or papaillae are shown around the oral suckrer and ventral sucker. At the end of the body, excretory pore was found, the shape was irregular. Transmission electron microscopic findings showed that plasma membrane, tegument, basal lamina, connective tissue, circular muscle layer, longitudinal muscle layer, nerve axon and tegumental cell were observed. In higher magnification, plasma membrane and bar-shaped granules were found at the outer surface of the tegument.
parasitology-helminth-trematoda ; Paragonimus westermani ; electron microscopy

The present study was undertaken to demonstrate the surface structure of Paragonimus westermani metacercaria in Korea with special reference to the distribution of sensory papillae. Metacercariae were isolated from crayfish, one of the second intermediate host of P. westermani in Bogil island, Chollanam-do (Province), Korea, where has been known as an endemic area of human paragonimiasis. Isolated metacercariae were excysted and examined with light, scanning and transmission electron microscopes for morphological features. On the surface of metacercariae, three types of sensory papillae were identified. Large domed papillae (3-5 micrometer), which were covered with wrinkled plasma membrane of the worm, were distributed on the oral and ventral suckers only. On the oral sucker, these large domed papillae were 12-13 in number. On the other hand large domed papillae on the ventral sucker were constantly 6 in number and hexagonal in distribution. Small domed papillae (2-3 micrometer), of which surface was more smooth than those of large ones, were distributed symmetrically on the ventral (30-32 pairs) and dorsal surfaces (40-42 pairs). Ciliated papillae (0.8-1.5 micrometer) were observed about 5-6 in number around the oral sucker and 3-5 pairs each on the ventral and dorsal surface of the body. Single pointed spines covered the entire surface of the body except around the excretory pore. Spines on the anterior part of the body were 0.9-2.0 micrometer in length and 45-55/100 square micrometer in number, and were gradually reduced in length (0.4-1.4 micrometer) and in number (12-27/100 square micrometer) toward the posterior part. The body wall of P. westermani metacercariae was consisted with anucleated syncytium layer, fibrous interstitial layer and musclar layer. In the anucleated syncytium, biconcave (0.15-0.55 micrometer) and spherical (0.08-0.16 micrometer) secretory granules, which were transferred from epidermal cells via protoplasmic tubules, mitochondria and ribosomes, were observed. Spines originated around the basement membrane protruded externally. Epidermal cells were consisted with a nucleus and a cytoplasm, and connected to syncytium with protoplasmic tubules. In the cytoplasm many secretory granules, mitochondria, Golgi complex, endoplasmic reticula, ribosomes and lipid droplets were observed.
parasitolgy-helminth-trematoda ; Paragonimus westermani ; electron microscopy

This survey was undertaken to determine the recent prevalence of lung fluke, Paragonimus westermani, in the three localities of Wiseong county, Kyungpook Province, Korea and to compare the prevalence among the residents in the same areas between 1924 and 1980. The three localities, Ku-seong, Sam-chun, and Um-ji villages (dong) have been known as the endemic areas of Paragonimus westermani. The surveys were made on the general population. They were examined using intradermal test with Paragonimus westermani antigen, and the diagnosis of paragonimiasis was made depending on the positive intradermal reaction. The sputum examination could not be performed beacause the residents were inaccessible. The prevalence of Paragonimus westermani among the residents in the three communities varied from 1.4 percent to 7.9 per cent, with an average of 4.0 per cent. Whereas, the average reported by Ichinomiya in 1924 was 4.7 percent. There are no significant differences in the sex and age specific rates of infection between 1924 and 1980. With the abundant density of Semisulcospira snails and crayfish in Sam-chun stream and the high rate of infection with Paragonimus westermani among the residents in the village, it is found that Sam-chun village, one of the three localitied in Wiseong county, where Ichinomiya (1924) surveyed, was still the endemic focus of Paragonimus westermani.
parasitology-helminth-trematoda ; Paragonimus westermani ; paragonimiasis ; epidemiology

Paragonimiasis has been recognized as a major public health problem in Korea. This disease is a chronic inflammatory process which frequently involve to the lung and rarely to other organs,(ectopic infection). A case of a ureteral stricture by ectopic infection of Paragonimus westermani at the retroperitoneum was presented with a brief review of literature.
Constriction, Pathologic* ; Korea ; Lung ; Paragonimiasis* ; Paragonimus westermani ; Public Health ; Ureter*

While paleoparasitologists in Korea reported scientific evidences for the infection patterns of various parasite species among the pre-modern Joseon people, historical study is also needed for understanding the socio-cultural aspects of parasitic infections of the past. In this study on the historical documents, we revealed the socio-cultural environment of Joseon society by which people were easily infected by trematode parasites. The historical records showed that Joseon people enjoyed raw fish cuisines, that might have caused Clonorchis sinensis and Metagonimus yokogawai infection, much more frequently than originally expected. It is also proven that Joseon people ate raw crab and crayfish, the intermediate host of Paragonimus westermani, as the seasonal delicacy or miracle cure drug for incurable diseases. We also found many Joseon records on raw-oyster dishes, possibly having caused Gymnophalloides seoi infection among the people. By this study, we could get the historical clues on how Joseon people could have been infected by various trematode parasites.
Astacoidea ; Clonorchis sinensis ; Heterophyidae ; Korea ; Paragonimus westermani ; Parasites* ; Seasons

In order to observe the protein compositions of soluble extracts of P. westermani, and their changes during early developmental stages, the crude saline extracts of 4, 6, 8, 10 and 12 week-old worms which were harvested from experimentally infected dogs were analysed by disc-PAGE. The results were as follows: A total of 15 bands were identified from electrophoregrams of respective developmental stages. Of them, 5 bands were recognized throughout the developmental stages. The number and protein amount of identified bands changed according to the worm development from 4 weeks to 12 weeks. However, the banding patterns of 4 and 6 week-old worms and 8 and 10 week-old worms were similar each other. Of 15 identified bands, band 1 was recognized only in 12 week-old worms whereas bands 3, 4, 8, 9, 10, 11 and 15 gradually lowered their amount according to development to disappear in 12 week-old. In addition, band 5 became a major band in 12 week-old while band 6 turned to a minor band at tha same age. The possible relations of changing patterns of protein bands with worm development were discussed.
parasitology-helminth-trematoda ; Paragonimus westermani ; immunology ; protein ; electrophoresis

The effect of praziquantel on P. westermani exposed in vitro was observed by stereomicroscope, light microscope and scanning electron microscope. Following results were found. The worms incubated in 0.01 micro-g/ml praziquantel were moving after 26-hour incubation. However, all of them were immobilized immediately after incubation in solutions over 0.1 micro-g/ml concentration. All of the exposed worms showed severe vacuolization not only in tegument but in subtegument, intestine, ovary, testis, Mehlis' gland and excretory bladder. Vacuoles in tegument burst out to form craters. As incubation time went on, tegumental structure was disintegrated severely. The worms exposed to praziquantel were observed to be immobilized and be vacuolized of all tissues. Disintegration of reproductive organs suggests that praziquantel have suppressive effect on egg production when the flukes are not killed. The drug effects were found more related with incubation time than with drug concentration.
parasitology-helminth-trematoda ; Paragonimus westermani ; electronmicroscopy ; chemotherapy ; praziquantel

Recent results of mass stool examination for parasitic infections revealed 0.01-0.0001 percent of Paragonimus egg positive rate in Seoul school-children. This survey was carried out to understand the infection status of intermediate hosts and their relations to human paragonimiasis in Seoul. Twelve mountainous streams in the outskirts of Seoul were surveyed. From all streams, Semisulcospira libertina, the snail intermediate host was not detected. From 7 streams 132 crayfishes, Cambaroides similis, the second intermediate host were collected. From them no metacercaria was found. The results indicated that crayfish in district of Seoul is no more an infection source of paragonimiasis. Possible factors related with the ecology of intermediate hosts were briefly discussed from the epidemiological view point.
parasitology-helminth-trematoda ; Paragonimus westermani ; host ; Semisulcospira libertina ; Cambaroides similis