• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.65-74
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• 1992

The tegumental ultrastructure of juvenile and adult Echinostoma cinetorchis (Trematoda: Echinostomatidae) was observed by scanning electron microscopy. Three-day (juvenile) and 16-day (adult) worms were harvested from rats (Sprague-Dawley) experimentally fed the metacercariae from the laboratory-infected fresh water snail, Hippeutis cantori. The worms were fifed with 2.5% glutaraldehyde, processed routinely, and observed by an ISI Korea DS-130 scanning electron microscope. The 3-day old juvenile worms were elongated and ventrally curved, with their ventral sucker near the anterior two-fifths of the body. The head crown was bearing 37∼38 collar spines arranged in a zigzag pattern. The lips of the oral and ventral suckers had 8 and 5 type II sensory papillae respectively, and bewteen the spines, a few type III papillae were observed. Tongue or spade-shape spines were distributed anteriorly to the ventral sucker, whereas peg-like spines were distributed posteriorly and became sparse toward the posterior body. The spines of the dorsal surface were similar to those of the ventral surface. The 16-day old adults were leaf-like, and their oral and ventral suckers were located very closely. Aspinous head crown, oral and ventral suckers had type II and type III sensory papillae, and numerous type I papillae were distributed on the tegument anterior to the ventral sucker. Scale-like spines, with broad base and round tip, were distributed densely on the tegument anterior to the ventral sucker but they became sparse posteriorly. At the dorsal surface, spines were observed at times only at the anterior body. The results showed that the tegument of E. cinetorchis is similar to that of other echinostomes, but differs in the number and arrangement of collar spines, shape and distribution of tegumenal spines, and type and distribution of sensory papillae.

• Parasites, Hosts and Diseases
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• v.30 no.4
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• pp.299-307
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• 1992

An antigenic protein in cystic quid of Taenia solium metacestodes (CF) of 150 kDa was measured by antibody-sandwich ELISA in serum and cerebrospinal quid (CSF) of neurocysticercosis patients. Capture antibodies were rabbit antisera against CF (RACF) and a monoclonal antibody (MAb) against 150 kDa protein in CF. Lower limit of antibody-sandwich ELISA was 8 ng/ml of the protein. Except CF, no tested helminthes extracts reacted. Levels of the protein in 351 sera from 255 patients (55 surgery confirmed and 202 antibody and CT/MRl confirmed) were below sensitivity of the assay. Of 276 CSF from 212 patients, 31 samples (11.2%) showed positive findings. This assay, therefore, was not sensitive enough to be a diagnostic. Instead, the 150 kDa protein appeared in CSF in such situations as in 2 days after prasiquantel treatment, or as in a patient infected with a racemose cysticercus with degenerated cyst wall. Of cases whose follow-up CSF were assayed, 2 cases showed that the protein appeared intermittently, These results suggest strongly that appearance of free 150 kDa protein is associated with cyst wall rupture. In CSF which contained the 150 kDa protein over 61 ng/ml, the protein was recognized in 505-PAGE before and after immunoprecipitation.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.241-245
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• 1983

PraziquantEI ($Distocide^{\circledR}$), the KcrEan product, was tEstEd for its safety and Efficacy in treatmEnt of Clonorchis sinensiJ infccticn during the period from April to SeptembEr, 1983 in Korea. A total of 55 egg positive cases were selected and treated with the regimen of 25 mg/kg t.i.d. for 1 day (total 75 mg/kg). The follow-up stool examination was done in 47 cases by cellophane thir;k smear and Stoll's egg counting techniques. The 8 uncured cases were treated again with the same regimen. The laboratory tests for blood picture and liver function were done in 27 cases and compared before and after the treatment. The results obtainEd are as follows: 1. After single course treatment, the cure and egg reduction rates were 83.0 and 99.1% respectively. With the second treatment, excellent results of 100% in both rates were obtained. 2. Several kinds of side effects such as dizziness, headache, etc. were complained by 29 cases (61.7 %), however, those were so mild and transient that no special treatment was necessary. 3. No significant change in laboratory findings was recognizable before and after the treatment. From the above results, it is concluded that $Distocide^{\circledR}$ is as effective and safe as $Biltricide^{\circledR}$ and highly recommendable in treatment of C. sinensis infection.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.270-280
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• 1983

Agar-gel Diffusion test (AGD), Counterimmunoelectrophoresis(CIEP) and Enzyme-Linked Immunosorbent Assay(ELISA) were examined with the sera of skin test positives for paragonimiasis. The crude antigen (Paragcnimus whole worm extracts: protein concentration, 7.56mg/m1) and human sera were used in AGD and CIEP. And in ELISA test, diluted antigen with 1:40, 000 of crude antigen and diluted sera with 1:100, 1:200 were used in the test. The positive identical ratio between AGD and CIEP reactions is 985 and negative identical ratio is 100%. One or three precipitin bands are observed in AGD. One to seven precipitin bands are also revealed in CIEP. Especially, deeply stained bands are observed in CIEP than those of AGD. The positive identical ratios between AGD and ELISA tests are 96% in 1:100 diluted sera, and 94% in 1:200 diluted sera. But the negative identical ratios between AGD and ELISA tests are 97% and 99% respectively in 1:100 and 1:200 diluted sera. The positive identical ratios between CIEP and ELIEA tests are 98% and 96% respectively in 1:100 and 1:200 diluted sera, but also 97% and 99% in 1:100 and 1:200. Control sera, such as clonorchiasis, amoebiasis and toxoplasmcsis, revealed all negatives with Paragonimus antigen in AGD, CIEP and ELISA tests. By above results, ELISA was mcst sensitive, next CIEP and AGD, But AGD test apprars to be more useful when used to crude antigen without cross rfacticn with other parasitic infections. CIEP test is basically equal in terms of precipitin reaction, but CIEP is able to be detected more sensitively and rapidly though less simple in handiwork than AGD. Consequently, three methods for inlmunological tests of paragonimiasis have gccd correlations with one another. Also, each of these has both merits and demerits in iymunolcgical test for paragonimiasis. But the ELISA test was proved to be the most sensitive and convenient tool for mass screening test, especially in cacti of using purified antigen.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.246-256
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• 1983

As epidemiological parameters of human paragonimiasis, the positive rates of intradermal test and the sputum/stool ekaminations have long been employed in population surveys. However, both the specificity of the intradermal test and the sensitivity of sputumjstool examination have been gradually declined as the endemicity was lowered; thus the gap between above two parameters widened. In such context, the development of a new epidemiologic parameter or tool which makes it possible to accurately discriminate the active paragonimiasis cases was necessary. In the present study, the detection rate of Paragonimus-speclac IgG antibody by micro-ELISA was evaluated as an indicator of epidemiologic status of human paragonimiasis in a population. A total of 4, 285 students and inhabitants living in Bukpyeong Myeon and Bukil Myeon, Haenam Gun, Jeonlanam Do was surveyed in October, 1983 by intradermal test first. Out of them, 244 cases (5.7%) were found positively reacted to VBS antigen of F. westermani. Out of 168 positive reactors, 7 cases (4.2%) were egg positive either by two times of sputum examination or by one stool examination. That indicated that only 0. 16% of total surveyed were confirmed as active paragonimiasis by egg detection. When sera collected from 239 positive reactors of Intradermal test were tested by micro-ELISA for their specific IgG antibody, 40 cases(16.7%) were found to be positive. All of 7 egg positive cases were again positive for specific IgG antibody. Among remaining 232 intradermal test positive cases, 33 cases were positive for IgG antibody. In contrast to those, none of 42 positive reactors to intradermal test for Cloncrchis and of 128 intradermal test negative cases showed positive for Paragcnimus-specIfic IgG antibody. The rate of specific IgG antibody as detected by micro-ELISA appeared to be increased with the wheal size of the intradermal test. When the wheal sixte was over 13mm in diameter, about 50% of them were positive for specific IgG antibody. Thirty-one specific antibody positive cases were clinically evaluated by laboratory examinations (repeated sputum examination, peripheral eosinophil count and chest roentgenogram) and by history taking. Out of them 24 cases were associated with one or more positive laboratory findings: thus considered as active paragonimiasis cases. Out of 7 lab. finding-free cases 3 revealed past history of typical paragonimiasis symptoms, suggesting that they were in chronic or in convalescent stages. The remaining 4 cases were considered as either mild or ectopic infection cases; the possibility of cross-reaction with other helminthiases could not be ruled out. From the above results, it was inferred that the detection of Paragonimus-specIfic IgG antibody by micro-ELISA was very much helpful in detecting the active cases as well as in proper evaluation of the endemicity of human paragonimiasis in a population. The convenience of mass haildling of sera in micro-ELISA was considered another superiority as an epidemiologic tool.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.116-186
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• 1983

An epidemiological study on Clonorchis sinensis infection along the Nam-river (total length ; 186km) flowing in Gyeongsang-nam-do, southern part of Korea, was carried out. Formalin-ether concentration technique and Stoll's egg counting method were employed to figure out the prevalence of C. sinensis infection. For the detection of cercariae from Parafossarulus sp., the snail host of C. sinensis, each snail was placed in aerated tap water, and examined for expelled cercariae. For observing the metacercariae the fresh water fish favorably eaten in raw conditions wore prepared by means of pressing the muscles between two slide glasses and/or by digesting them with artificial gastric juice. The fresh water fish were fed to the rabbits to get the worms and to identify the morphology of adult C. sinensis. The results are summarized as follows: 1. Overall Prevalence of C. sinensis infection was 38.75 from 5,291 examinees; 44.15 (1,408 out of 3,196) in male and 30.4% (637 out of 2,095) in female. 2. The prevalence rates were 42.0% at the upper stream, 41.2% around the vicinity of Jinyanglake, 34.2% at Jinju city, 34.2% at middle stream and 40.3% at down stream regions, respectively. 3. By age, the highest positive rate (53.4∼54.3%) was observed in 30 to 59 years of age. In this age group, the rate in males was 59.7∼62.2%, and in females 42.2∼44.4%, In the age group of less than 19 years it was 7.5∼20.9%. 4. By social strata, the positive rate was 16.5% in the primary school children, 22.6% in school students, 46.2% in teachers and local officers and 49.6% in the general inhabitants. 5. The quantitative examinations with the stool collected from clonorchiasis cases revealed that the light infection (less than 4,000/EPG) was 53.6%, moderate infection (4,001∼10,000 /EPG) 30.3% and heavy infection (more than 10,001/EPG) 16.1%, respectively. More than half of total cases examined were light infection, and 73.2% of female examinees were lightly infected with this cuke. 6. The average value of EPG was 4,963 (male, 6,057; female, 2,557 and the highest value was obtained from the age group of 30 to 59 years (5,240∼6,454). 7. The prevalence of Metagonimus yokogawai infection in humans was 5.5%, and 89.8% of metagonimiasis cases wore double-infected arith C. sinensis. The highest prevalence rate was observed in Jinju city (11.2%). 8. Total of 5,005 Parafossarulus sp., the snail intermediate host of C. sinensis, were examined for the detection of cercariae. The cercarial expulsion rate was 0.34%, and the snails collected in Jin-yang-lake side and in the down stream expelled mainly the cercariae of C, sinensis. 9. About 788 cercariaejday (range: 127∼1,503) were expelled daily from a snail naturally infected with C. sinensis. The snails which released more than 1,000 cercariae/day were 30.8% out of total collected. A snail uniquely released 5,840 cercariae/day in this study. 10. The other trematode cercariae besides C. sinensis were also detected, and the rates out of total snails were the cercariae of Losogenes liberum 6.71%, Cyathocotyle orientalis 0.26%, Notocotylus attenuatus 2.52% and Mucobucaris 0.54%, 11. Ten out of 18 species of fresh water fish caught along the river harbored the metacercariae of C, sinensis. The highest rate of metacercarial infection in fish was detected in Pseudorasbora larva (85.9%). The fish mainly eaten by the inhabitants along the Nam-river, and the metacercarial infection rates were: Zacco platypus 8.0%, Hemibarbus sp. 18.2∼26.7%, Gnathepcgcn sp. 37.5%, Ischikauia steenackeri 42.9% and Pseudogobio esocinus 16.7%. 12. Out of 36 P. larva, the number of metacercariae were about 109 (ranEe; 18∼446) per fish and 27 per gram of flesh. The fish caught in spring harbored the highest number of metacercariae. As indicated above, the prevalence of C. sinensis infection in the inhabitants residing around the Nam-river was relatively high. The farther toward the upper stream areas, the higher was the positive rate of C. sinensis infection, and most of clonorchiasis cases were lightly infected. The snail hosts of C. sinensis distributed all around the Nam-river. Several species of freshwater fish were infected with the metacercariae of C. sinensis and the infection rates were relatively high. To prevent C. sinensis infection in the endemic areas, the effective health education system is suggested as a control measure, although mass treatment is also expected to be useful, using chemotherapeutic agents such as "praziquantel", a recently developed anthelminthic for C. sinensis inftraction.

• Parasites, Hosts and Diseases
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• v.27 no.4
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• pp.261-270
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• 1989

The present study is intended to observe the chronologic changes of experimental sparganosis by histopathological observation and detection of circulating anti-sparganum IgG antibody using ELISA. Each of 25 mice was infected with aye spargana, and they were examined after 1, 2, 4, 10 weeks or 6 months from infection. The followings are summarized results. - 1. The plerocercoids were detected in the subcutaneous tissue of the trunk, neck or axilla, but a few often extended into the skeletal muscle. The recovery rates were 72% at the first week, 80% at the second week, 95% at the fourth week, 92% at the tenth week and 100% at .the sixth month. The larvae grew slowly in both length and weight until 6 months. 2. Histopathologically, most of the larvae were observed alive in the soft tissue or skeletal muscle. Numerous eosinophils, neutrophils, Iymphocytes and plasma cells were infiltrated focally around the worms by the second week, but they surrounded the worms to form a layer of inflammatory reaction after 4 weeks of infection. Also histiocytes and fibroblasts began to appear around the inflammatory cells at 4 weeks. After 10 weeks, the worms encircled by a thin fibrous layer were found. After 6 months, the worms were surrounded by either fibrous tissue or active inflammatory cells. The inflammation looked more severe in the tracks left by the worms, rather than around the worms. 3, The level of anti-sparganum IgG antibody in the serum showed an increase by the fourth week, and a rapid and continuous increase was observed thereafter by the tenth week after infection. The high level of the IgG antibody was maintained up to 6 months forming a plateau curve. The present results suggest that the tissue reaction and antibody production in subcutaneous sparganosis become distinctive by the fourth week after infection.

• Parasites, Hosts and Diseases
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• v.26 no.2
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• pp.73-86
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• 1988

The sensitivity and specificity of crude and affinity-purified antigens of Clcnorchis sinensis obtained from the infected rabbits were studied. Stage-specific antigenic proteins from the eggs, metacercariae and adult worms were characterized by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunosorbent astray (ELISA). The results were as follows: 1. The antibody.binding antigen (ABA) purified from whole worm crude antigen (IVWA) by CNBr-activated Sepharose 4B affinity chromatography made :l specific bands against rabbit antisera on Ouchterlony gel diffusion plate, while WWA made 7 bands. Major WWA protein bands by SDS-PAGE were found at 16, 300~18, 500 and 28, 000~29, 000 daltons, while major ABA protein bands were at 18, 000~21, 000 and 29, 000~31, 000 daltons. The reactivity of ABA with rabbit anti-sera in ELISA was remarkably less sensitive than that of WWA. 2. Molecular weights of egg antigen (EGA), metacercarial antigen (MEA) and adult worm antigen (WWA) of C. sinensis ranged from 15, 000-200, 000 daltons, 15, 000-100, 000 daltons and 11, 000~80, 000 daltons, respectively. Major WWA proteins consisted mainly of polypeptide bands of low molecular weight, less than 31, 000 daltons, while those of EGA and MEA consisted of higher molecular T.eights than 30, 000 daltons. 3. The ELISA reactivities of WWA to rabbit anti.sera were remarkably greater than those of MEA. EGA showed negative reaction throughout the experiments. WWA showed higher optical density (O.D.) than 1.0, when reacted with rabbit anti-sera obtained at 4~6 weeks after the infection. In the rabbit anti-sera later than 12 weeks after the infection, the O.D. reacting witll WWA showed a plateau without variation. MEA shoT.ed relatively low O.D. values (<0.6), when reacted with anti-sera from lightly in(ected groups throughout the experiments, althougll there were some wealth positive cases (O.D.>0.6) ill heavily infected groups. MEA reacted with rabbit anti-sera showed negative results on Ouchterlony gel diffusion plates. Summarizing the above results, it is suggested that the whole worm antigen prepared from the adult worms of C. sinensis is most highly antigenic. However, this antigen might reveal cross reactions with other trematodes such as Paragonimus westermani, therefore, purification of antigenic proteins from the crude antigen is essential 18 increase the sensitivity and specificity for the immuncdiagnosis of clonorchiasis.

• Parasites, Hosts and Diseases
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• v.26 no.2
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• pp.95-106
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• 1988

Specific or non-specific cytolytic processes of free-living amoebae causing meningoencephalitls have been emphasized and the cytolytic ability related to hydrolases in Entantoeba sp. and Naegleria sp. has also been reported since the latter half of 1970's. However, no information on hydrolase activities in Acanthamoeba sp. is available. Hydrolases in Acanthamoeba culbertsoni, a pathogenic species of free-living amoebae, were assayed and compared with those in a non-pathogenic species, A. royreba. Pathogenicity of these two species was confirmed through experimental infection to BALB/c mice. Hydrolase activities and cytotoxic effects between pathogenic and non.pathogenic species were compared in the trophozoites cultured in CGV media and in CHO cell line, respectively. The results are summarized as follows: 1. The mice infected with A. culbertseni were all dead 15 days after nasal inoculation, and the mean survival time was 8.5 days. Also the mice infected with this pathogenic species manifested typical meningoencephalitis, whereas the mice infected with A. royreba did not. 2. Hydrolases detected both in the cell extracts and culture media were acid phosphatase, ${\beta}-N-acetyl$ galactosaminidase, ${\beta}-N-acetyl$ glucosaminidase, ${\alpha}-mannosidase$, neutral proteinase and acid proteinase, all of which were detected with remarkably higher rate in A. culbertsoni than in A. royreba. 3. A. cuzbertsoni revealed strong cytotoxicity for the target CHO cells, whereas A. royreba did not show any specific cytotoxicity. About 80% of the target cells mixed with A. culbertsoni were dead 48 hours after cultivation, and more than 95% of the target cells were dead 72 hours after cultivation. 4. Hydrolase activities in A. culbertsoni cultured with the target cell line were assayed according to the culture time. The activities of acid phosphatase, ${\beta}-N-acetyl$ galactosaminidase, ${\beta}-N-acetyl$ glucosaminidase, ${\alpha}-mannosidase$ and acid proteinase in this pathogenic amoeba were detected higher in amoeba extracts than in culture media up to 120 hours after cultivation, but after 120 hours of cultivation those activities were detected higher in culture media than in the amoeba Iysates. Neutral proteinase activity in A. culbertsoni increased more in EBSS medium than in the Iysate specimens although the activity in the extracts was generally steady according to the cultivation time. Summarizing the above results, it is concluded that there were differences in hydrolase activities between Pathogenic A. culbertsoni and non-pathogenic A. royreba, and that some hydrolase activities were detected remarkably higher in A. culbertsoni which revealed strong cytotoxicity to the target CHO cell line.

• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.113-124
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• 1992

Protective effects of monoclonal antibodies against n. fowleri were comparatively studied. nALB/c mice were treated with two types of monoclonal antibodies, Nf 2 and Nf 154, before and after the infection with N. fowleri. The mortality and mean survival times were then compared. Also, direct effect of the monoclonal antibodies on the N. fewleri trophozoites in vitro were observed. In vitro protective effects of the monoclonal antibodies were also studied in cells infected with N. fowleri. The observed results are summarized as follows: 1. Among mice pretreated twice before the infection with monoclonal antibody Nf 2 (McAb Nf 2), only 15.8% were killed, and the mean survival time was 17, 7 days. This was not much different from the mice pretreated once, as the mortality and mean survival time were 16.7% and 17 days. Those effects were compatible with monoclonal antibody Nf 154 (McAb Nf 154). The above findings contrast with the mortality and mean survival time of the control mice, which were 22.7% and 14.6 days respectively. 2. Mice which received twice the McAb Nf 2 following N. fowleri infection incurred a 19.4% mortality rate with 13.6 days survival time; 17.9% and 15.8 days with on time administration, in contrast to the 25% and 14.6 days in the control group. 3. Marked agglutination effect of McAb Nf 2 or McAb Nf 154 were observed on n. fowkwi, trophogoites. 4. When N, fowleri trophozoites were treated with McAb Nf 2 or McAb Mf 154 combined with comments, the proliferation rate was more significantly suppressed than in that the control, 5. N. fowleri trophozoites treated with McAb Nf 2 or McAb Nf 154 showed an increased number of swollen mitochondria, disfigured cisternal, lipid droplets, and osmiophilic granules in the cytoplasm. 6. A remarkable protective effect of monoclonal antibodies was noticed in CHO cells infected with N. fowleri. More than 90.6% of the infected CHO cells survived, contrasted with 27% of untreated cells. The overall results in this study suggest that N. fewleri treated with monoclonal antibodies against N. fowleri reduce the mortality and prolong the survivial time of the mice when the antibodies are administered before the infection. The protective effect of the monoclonal antibodies is surmised being caused by agglutination of the trophozoites.