• The Korean Journal of Malacology
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• v.15 no.2
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• pp.121-125
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• 1999

The present study aimed to elucidate whether and intestinal fluke, Gymnophalloides sp. exist in Gogunsan-gundo located at western part of Korean Peninsula; about 100 km apart from Gunsan city, Jeollabuk-do, Korea. The survey was carried out Two times each in 1997 and 1998, examining stool samples by means of formalin-ether concentration method. Results are summarized as follows : of 411 fecal samples examined, Gymnophalloides sp. positives were 19 (8.9%); 9.5% inMunyeodo, 1% in Seonyudo, but none in Jangjado. The positive cases did not show any specific clinical complaints. Prevalence rate of Gymnophalloides seoi metacercariae from oysters, Crassostrea gigas were 80.8%

• Parasites, Hosts and Diseases
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• v.41 no.1
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• pp.27-33
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• 2003

The developmental features, growth and organogenesis of Macroorchis spinuiosus were observed in albino rats. Globular and thick walled metacercariae, possessed a stylet, Y-shaped excretory bladder and extracecal testes. Un albino rats, M. spinulosus showed habitat shifting. The majority of M. spinulosus reside in the jejunum for the first four days post Infection (p.i.) and migrate to the duodenum at the later stage of infection. M. spinulosus grew rapidly during the first four days and reached full maturity at 14 days p.i. and later reduced in size. The ovary was separated from the genital primodium at one day p.i. The seminal vesicle appeared on the third day and divided into two sacs on the fourth day p.i. and intrauterine eggs and sperm mass were produced on the fourth day. Organogenesis and enlargement of reproductive organs governed the growth of M. spinulosus. The similarity of related species of the genus Macroorchis to M. spinulosus was discussed In consideration to developmental features.

• Parasites, Hosts and Diseases
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• v.35 no.2
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• pp.135-138
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• 1997

This study was performed to observe intestinal patholoay ill early Infection by Centrocestus crnlctus. The flukes were in the lowermost part of the intfrvillous space of the duodenum and jejunum from 1 day to 7 days postinfection (PI). Thr stroma of villi around the young fluke was edematous and infiltrated by inflanlrllatory knells Luch as Iymphocytes, plasma cells and eosinophils. The crypt became mildly llyperplastic and villi were moderately atrophied at 4 days Pl. The intestinal lesion produced was confillrd to the areas around the fluke. The pathologic findings were not significarltly different between 1,000 and 5,000 metacercariae infection groups. It is suggested that the lesion should be produced by mechanical destruction of the fluke on the enteroepithelial cells.

• Parasites, Hosts and Diseases
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• v.48 no.4
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• pp.303-307
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• 2010

Stellantchasmus falcatus is a minute intestinal fluke in the family Heterophyidae. Metacercariae, the infective stage, were reported in a marine fish, mullet Liza subviridis, and a fresh water fish, Dermopgenus pusillus, in Thailand. Adults were found in chicks, rats, cats, and humans. Morphological studies were done for comparing Stellantchasmus sp. worms found in 2 different fish hosts; their shapes and organ arrangements were very similar except for the prepharynx length. Therefore, the present study aimed to compare their DNA fingerprints using the HAT-RAPD method for both types of Stellantchasmus and several other related species. Ten arbitrarily selected primers (OPA-04, OPA-09, OPN-02, OPN-03, OPN-09, OPN-12, OPP-11, OPR-15, OPX-13, and OPAD-01) were used. It was found that OPA-09, OPN-03, and OPAD-01 were able to generate S. falcatus specific fragments in mullets which consisted of 200, 760, and 280 bp, respectively. In addition, the results of morphologic, DNA fingerprinting, and phylogenetic analyses strongly suggest that the fresh water and marine specimens of Stellantchamus may be different species.

• Parasites, Hosts and Diseases
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• v.37 no.2
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• pp.77-83
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• 1999

To ascertain residual sonographic and histopathological findings of clonorchiasis after treatment, the present study evaluated sonographic findings in rabbits which were infected with 500 metacercariae of C.sinensis every 6 months for 18 months after treatment with praziquantel. The sonographic findings were analyzed in terms of intrahepatic bile duct dilatation and periductal echogenicity, and histopathological findings were observed after the last sonographic examination. Compared with the sonographic findings before treatment, dilatation of the intrahepatic bile ducts became mild to some degree in four of the seven cases and increased periductal echogenicity resolved in four of them. The histopathological specimens after 18 months showed that periductal inflammation has almost resolved but moderate dilatation of the intrahepatic ducts and mucosal hyperplasia persisted. The periductal fibrosis minimally resolved. The log-lasting sonographic findings in cured clonorchiasis make sonography less specific.

• Parasites, Hosts and Diseases
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• v.41 no.2
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• pp.107-111
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• 2003

The surface ultrastructure of Acanthotrema felis (Trematoda: Heterophyidae) adults, recovered from a kitten experimentally infected with the metacercariae, was observed using a scanning electron microscope. The worm was leaf-like, ventrally concave and covered with scale-like multi-pointed tegumental spines. The spines on the anterior surface were short but broad, and had 10-12 pointed tips. The cytoplasmic processes protruded around the spines, like pockets for the spines. The ventrogenital opening was crescent, or kidney-shaped, and had protuberances with minute spines on its surrounding tegument. The spines on the posterior surface were long, but narrow, with 6-8 pointed tips. The cytoplasmic processes on this tegument were ridge-like, and elevated along the row of the spines. The surface ultrastructure of A. felis is generally similar to that of other heterophyid flukes, but some features are characteristic, and may be of taxonomic and bio-ecological significance.

• Parasites, Hosts and Diseases
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• v.37 no.4
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• pp.285-287
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• 1999

Changes in the expression level of splenocyte $IFN-{\gamma}$mRNA of Sprague-Dawley (SD) rats infected with Paragonimus westermani were analyzed by competitive reverse transcription-polymerase chain reaction (RT-PCR) followed by southern blot. The template RNA was extracted from the splenocytes of rats infected with 20 metacercariae of P. westermani. The products of competitive RT-PCR were subjected to southern blot and enhanced chemiluminescence (ECL), and analyzed with a densitometer. In comparison with that of uninfected control rat splenocytes (value of 1), the levels of mRNA expression of $IFN-{\gamma}$had changed to 0.747 at 1 week post infection (PI), 0.00175 at 2 week PI, 0.0217 at 3 week PI, 0.194 at 4 week PI and then to 0.537 at 5 week PI. The level at 7 week PI had returned to 1.25, comparable with that of uninfected rats. These results show that, when infected with p. westermani, the levels of $IFN-{\gamma}$ mRNA of SD rat splenocytes were remarkably reduced by more than 500 times at 2 week PI and restored to normal level at 7 week PI.

• Applied Microscopy
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• v.28 no.4
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• pp.527-538
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• 1998

This study was performed to investigate the activity of antibodies in the tissues of Paragonimus westermani at the different developmental stages. Enzyme-linked immunosorbent assay (ELISA) and Immunelectron microscopy (IEM) were applied, using the dog sera infected with metacercariae isolated from Cambaroides similis. These dog sera were obtained from 3rd to 96th week after infection by bleeding. The supernatants of homogenated worms for worm antigen were used. The worm tissues were embedded in Lowicryl HM 20 medium, treated with infected serum and protein A gold complex (particle size; 12 nm) and observed by electron microscope. In the pattern of antibody levels by ELISA test in all developemental worm antigens, the activity of antibody was very weak in the 3rd week, but strong in the worm antibody from 4th to 20th week after infection. Its activity was maintained even till 96th week. The antibody level of the L2th week worm antigen was higher than those of the 20th and 48th week worm antigens. Generally, many gold particles were observed on the secretory granules and the epithelial lamellae. Thus, it was concluded that the antigenic materials in the developmental worm tissues were especially concentrated on the secretory granules in the parenchymal tissues and the epithelial lamellae in the lumen of the caecum.

• Parasites, Hosts and Diseases
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• v.28 no.1
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• pp.39-44
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• 1990

The life history of Echinostoma cinetorchis was completed in the laboratory using Hippeutis cantors as the first and second intermediate host. The incubation for maturation of eggs and hatching of miracidia took 24 days at 28℃. On the 66th day after miracidial challenge, 16 snails were crushed and examined for the presence of E. cinetorchis larvae. The metacercariae were detected in all of the snails, and from three of them were found the rediae and cercariae. The morphological characteristics of the larvae and the experimentally obtained adults were compatible with that of E. cinetorchis.

• Parasites, Hosts and Diseases
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• v.50 no.1
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• pp.45-51
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• 2012

Fascioliasis is one of the public health problems in the world. Cysteine proteinases (CP) released by $Fasciola$ $gigantica$ play a key role in parasite feeding, migration through host tissues, and in immune evasion. There has been some evidence from several parasite systems that proteinases might have potential as protective antigens against parasitic infections. Cysteine proteinases were purified and tested in vaccine trials of sheep infected with the liver fluke. Multiple doses (2 mg of CP in Freund's adjuvant followed by 3 booster doses 1 mg each at 4 week intervals) were injected intramuscularly into sheep 1 week prior to infect orally with 300 $F.$ $gigantica$ metacercariae. All the sheep were humanely slaughtered 12 weeks after the first immunization. Changes in the worm burden, ova count, and humoral and cellular responses were evaluated. Significant reduction was observed in the worm burden (56.9%), bile egg count (70.7%), and fecel egg count (75.2%). Immunization with CP was also found to be associated with increases of total IgG, $IgG_1$, and $IgG_2$ ($P$<0.05). Data showed that the serum cytokine levels of pro-inflammatory cytokines, IL-12, IFN-${\gamma}$, and TNF-${\alpha}$, revealed significant decreases ($P$<0.05). However, the anti-inflammatory cytokine levels, IL-10, TGF-${\beta}$, and IL-6, showed significant increases ($P$<0.05). In conclusion, it has been found that CP released by $F.$ $gigantica$ are highly important candidates for a vaccine antigen because of their role in the fluke biology and host-parasite relationships.