As a series of systematic classification of paramphistomes, the worms in the rumen and reticulum were collected on 214 Korean cattle slaughtered at Jeonju abattoir from January 1986 to April 1987 and were classified by means of morphology. Afterwards, the karyotype of Paramphistomum cervi (Zeder, 1790) was detected by means of modified air-drying method from germ cells of the worms. The results were summarized as follows: In the chromosome number of 254 P. cervi, the haploid cell was n=9 and the diploid 2n=18. The meiotic divisions were observed frequently; 1,924 haploid and 32 diploid cells were reliable. Nine pairs of mitotic chromosomes were homologous in the metaphase stage, and the chromosomes were composed of five medium-sized metacentrics (m), subtelocentrics (st) or submetacentrics (sm) and four small-sized subtelocentrics(st) or submetacentrics(sm). Meiotic metaphase was composed of five medium and four small chromosomes in size. As a series of C-banding method, C-band was showed in centromeric region from all of the haploid germ cells. Whereas chromosome No. 3 and 5 included heterochromatin on the tip region, chromosome No. 4 on the distal region and No. 6 proximal region. And chromosomes No. 2 and 8 showed a remarkable C-band distinguished from other chromosomes.
parasitolgy-helminth-trematoda ; Paramphistomum cervi ; karyotype

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

The author investigated the larvicidal action of liquid nitrogen against the metacercariae of Clonorchis sinensis, with an observation on the freshness and change of taste in the flesh of fishes. The results obtained were as follows: The metacercariae in the flesh of Pseudorasbora parva, which were treated with liquid nitrogen (-192C), were not killed within 10 seconds, but completely killed over 30 seconds. In comparison, the metacercariae in the flesh of P. parva kept in a refrigerator (-12C) were killed only in 84 percent in 10-hour exposure group. The freezing speed of fishes by liquid nitrogen was 4 min. (') and 15 seconds(") for Cyprinus carpio, 1'22'' for Carassius carassius and only 30'', for Pseudorasbora parva. As for the freshness and taste of raw fresh water fishes, they were not deteriorated after the treatment with liquid nitrogen. In animal infection experiment of C. sinensis metacercariae after freezing, they were found not infective after they were treated with liquid nitrogen. From the results, it is inferred that the treatment of fresh water fishes for longer than 30 seconds with liquid nitrogen is helpful to reduce the possibility of C. sinensis infection without alteration of the freshness and taste of fishes.
parasitolgy-helminth-trematoda ; Clonorchis sinensis ; metacercaria ; toxicology ; liquid nitrogen

The present study was carried out to examine the effect of a carcinogen, aflatoxin B1 on the ultrastructural changes of biliary epithelial cells in mice infected with Clonorchis sinensis. A total of 93 male albino mice(BALB/c strain) was divided into 3 groups; group I, treated with 1.0 ppm aflatoxin B1 for 12 weeks; group II, given 50 C. sinensis metacercariae, and group III, given 50 metacercariae and treated with 1.0 ppm aflatoxin B1 for 12 weeks. Three mice served for untreated-uninfected controls. From 4 weeks after the treatment and/or infection, three mice from each group were sacrificed at 4 week intervals up to the 40th week, and their hepatobiliary tissues were prepared for transmission electron microscopy. The most prominent ultrastructural changes in group I were remarkable enlargement of nuclear size, separation of nucleolus, dispersed chromatin granules in nuclei and increased dense granules along the inner membrane of nuclei. In the cytoplasm there was slight proliferation of mitochondria and endoplasmic reticulum (ER) at earlier stage. At the 12th week separation of fibrillar and granular components of the nucleolus was a characteristic finding. As the time elapsed, epithelial cells showed flattened-cuboidal form and a tendency of atrophy. Most of the nuclei were elongated and polygonal in shape. In group II the appearance of elaborate interwoven folds of lateral cytoplasm forming a labyrinth of interconnected intercellular space and variety in nuclear shape were the prominent findings at earlier stage. The cytoplasm showed slight proliferation and dilatation of mitochondria and ER, and a small number of mucin droplets. In the basement membrane scanty fibrous cells were seen. With time, variety in nuclear shape, marked proliferation and dilatation of rough ER and some collagen fibrils were demonstrated. Other features of intracellular organelles and mucin droplets persisted. In group III cuboidal epithelial cells showed their remarkably enlarged and irregular nuclei, increased chromatin granules in the nuclei, separated nucleoli, proliferated and dilated rough ER. With time, sequestered mitochondria showed bleb-like evaginations which lacked cristae and dense matrix, and were limited by a single membrane. Since the 20th week, microvilli were relatively scanty and poorly developed. Organelles and inclusions in the cytoplasm of metaplastic cells were poor. Nuclei were variable in shape. The most prominent changes at later stage were separation of nuclei from the cytoplasm, and appearance of numerous and irregularly angled electron dense granules in the nuclei.
parasitolgy-helminth-trematoda ; Clonorchis sinensis ; electron microscopy ; pathology ; toxicology ; aflatoxin

In order to observe the feasibility of serologic diagnosis of metagonimiasis, saline extracts of metacercariae and 4-week old adults were prepared. Sera from 25 experimentally infected cats were collected from 3 days to 12 weeks after infection. Their levels of specific IgG antibody were measured by ELISA together with 3 sera from non-infected cats. Specific IgG antibody levels began to rise in 7 days after infection, reached their peak in 2-4 weeks and made a plateau thereafter. Cats infected with hundreds of adult worms showed minimal rise of the antibody level. Adult antigen was superior to metacercarial antigen in detecting the specific IgG antibody.
parasitolgy-helminth-trematoda ; cat ; metagonimiasis ; Metagonimus yokogawai ; IgG ; enzyme-linked immunosorbent assay

Circulating antigens in rats experimentally infected with Paragonimus westermani were examined by ELISA. From a total of 22 albino rats, each fed with 25 metacercariae, blood samples were collected until 12 weeks after infection. The specific antibodies against P. westermani in the serum of an infected cat were purified by ammonium sulfate precipitation, DEAE anion-exchange chromatography and affinity chromatography serially. So-called double antibody sandwich ELISA method was used for the detection of circulationg antigens. The results were as follows: Mean value of O.D. in control sera was 0.04 (S.D.=0.04). After infection, mean O.D.(S.D) values were changed serially: 0.03(0.01) at 0.5 week(3 days), 0.55(0.50) at 1 week, 0.69(0.45) at 1.5week, 0.20(0.19) at 2 weeks and 0.13(0.10) at 2.5 weeks of infection. They returned, thereafter, to the level before infection. When 0.16(mean+3 S.D.) were considered as cut-off value, those higher than 0.16 were observed only in the sera collected between 1 and 2.5 weeks after infection. Average 8.4 immature worms (2.2 from the lungs and pleural cavities; 6.2 from muscles) were recovered in a rat at 12 weeks after infection. The fact that circulating antigens were not detected after 3 weeks of infection was considered to be caused by the formation of antigen-antibody complexs.
parasitolgy-helminth-trematoda ; Paragonimus westermani ; rat ; enzyme-linked immunosorbent assay ; antigen ; rat

The rabbits were infected with Clnorchis sinensis and were treated with praziquantel at the dose of 50 mg/kg x 2 x 2 days afer 1, 2, 4, 8 weeks and 7 months from the infection. Their livers were observed histopathologically 1, 4 and 12 weeks after treatment. The findings are summarized as below: The changes of the liver in control rabbits were relatively mild until 2 weeks after infection. However, widening and thickening of bile ducts, proliferation of biliary epithelium and periductal fibrosis were moderate after 4 weeks from infection and those changes were severe after 8 weeks and 7months. Goblet cell metaplasia was found after 8 weeks from infection. The mild changes of 2-week infection group were completely recovered by 4 weeks after the treatment. In the groups of 4 or more weeks after infection, the changes of bile ducts became milder in the degree after the treatment, but were still found 12 weeks after the treatment. As the infection duration was passed, more severe changes were observed after the treatment. In this context, it is concluded that the liver changes of acute clonorchiasis in the early two weeks are reversible by treatment while chronic biliary epithelial changes are irreversible. Therefore, early treatment should be recommended as possible to minimize the remaining histopathological changes of liver in clonorchiasis.
parasitolgy-helminth-trematoda ; Clonorchis sinensis ; liver ; clonorchiasis ; chemotherapy ; praziquantel ; pathology ; rabbit