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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.

In order to observe the protein composltlOns 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: 1. A total of 15 bands were identified from electrophoregrams of respective developmental stages. Of them, 5 bands were recognized throughout the developmental stages. 2. The number and protein amount of identified bands changed according to the worm development from 4 weeks to 12 weeks. However, tLe bar::ding patterns of 4 and 6 week-old worms and 8 and 10 week-old worms were similar each other. 3. 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 dcvelor:ment 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 the same age. The possible relations of changing patterns of protein bands with worm development were discussed.

The distribution patterns of worm burden of Enterobius vermicularis were studied in a primary school in rural part of Korea, on July, September and November 1976, for successively three times on 285 children. Out of the subjected children treated with pyrantel pamoate at the dose of 10 mg/kg body weight, 107 in the first, 55 in the second and 43 in the third trials were cooperative in the satisfactory collection of whole amount of feces for three days in respective trials. The distribution patterns of worm burden in these subjected children were considered by statistical analyses for the fitness with theoretical lognormal and negative binomial frequencies. The theoretical values from equations of lognormal distribution was fitted to the observed frequency distibution patterns throughout three trials, but in the second trial undertaken on September 17, 1976, both the lognormal and negative binomial were found to fit the observed data, probably because of rarity of heavy infection cases and high frequency of noninfected cases.

Cotylaspis coreensis sp. n., Cotylaspis sinensis Faust et Tang, 1936, Phyllodistomum parasiluri Yamaguti, 1934, Kaurma orientalis Yamaguti, 1937, Astiotrema reniferum (Looss, 1898), Astiotrema odhneri Bhalerao, 1936, Astiotrema sp. and Cephalogonimus japonicus Ogata, 1936 were collected from the intestine of freshwater mud-turtle, Amyda sinensis Wiegmann in Korea which were purchased at Namdaemoon Market of Seoul on October 1968 and May 1977. Cotylaspis coreensis differs from other members of the genus in relatively large size of pharynx, the number and distribution of vitelline follicles, size of testis, length of intestine and position of genital opening. Distribution of Cotylaspis sinensis was firstly recorded in Korea. Phyllodistomum parasiluri collected in this study was considered to be the first to recover from the reptilian host although the collected worms were still immatured. The genus Astiotrema collected in this study were divided into three species, A. reniferum which is hitherto unrecorded in Korea, A. odhneri which had been described as A. orientale, A. amydae and A. fukuii and another Astiotrema sp. which differs from the former two species in minor differences in size of suckers, size of ova and size of cirrus pouch. The distribution of Cephalogonimus japonicus was firstly recorded in Korea.

To observed whether the specific IgG antibody test using ELISA was useful in diagnosis of presently ill patients of paragonimiasis, a total of 95 sera were tested. The sera were collected from 21 egg positive cases, 8 from positive reactors of intradermal test, 7 from Clonorchis infected, 9 from other parasitic diseases and 50 from apparently non-infected cases. By the result, the sensitivity of the test was 86% and the specificity was 100%. There were no cross reactions between Paragonimus antigen and other parastic infections. Specific IgG antibody test by micro-ELISA was concluded to be useful for mass screening of the presently ill paragonimiasis in the field.

In order to correlate the number of eggs in female Enterobius vermicularis with their body length and to re-evaluate the number of eggs liberated by gravid females, a total of 203 worms were examined. Those females were removed from naturally infected orphans with mebendazole (100 mg) and had been fixed in 10 percent formalin(Cho et al., 1981). The decent ones which were selected under dissecting microscope were unbroken, neatly fixed females without contaminated eggs on their surface. The worms were measured by their body length, softened in 0.1N NaOH solution overnight, and teased by dissecting needles. And their number of shelled eggs was measured in a counting chamber made as described by Denham et al. (1971). The results were summarized as follows: The observed females, 4.10~9.90 mm long, began to have shelled eggs in uterus when body length was 5.50 mm or longer. The percentage of females with eggs in uterus was as follows by range of body length: 25 percent in 5.50~5.99 mm long, 53.3 percent in 6.00~6.49 mm long, 86.7 percent in 6.50~6.99 mm long, 95.2 percent in 7.00~7.49 mm long and 100 percent in 7.50 mm or longer. The mean and standard deviation of egg number were as follows by the length of females: 19+/-50 in 5.50~5.99 mm long, 734+/-1,597 in 6.00~6.49 mm long, 1,473+/-1,606 in 6.50-6.99 mm long, 1,530+/-2,055 in 7.00-7.49 mm long, 2,567+/-2,046 in 7.50-7.99 mm long, 5,598+/-2,470 in 8.00~8.49 mm long, 9,318+/-2,651 in 8.50~8.99 mm long, 10,678+/-2,892 in 9.00~9.49 mm long and 13,323+/-1,778 in 9.50~9.90 mm long. The numbers of uterine eggs showed greater individual variation when the female lengths were in range of 5.5~8.0 mm. When the female length was longer than 9.0 mm, the egg numbers were over 10,000 in majority, and showed lesser individual variations. Above results suggested that the egg production in female E. vermicularis began in 28-32 days after infection and that in early stages, the egg production varied by individual worms, but in gravid females longer than 9.0 mm at last deposited 10,000 to 16,000 eggs in their uterus with the least individual variations.

Five cases of Diphyllobothrium latum infection were proved by collection of worms after treatment with bithionol, niclosamide or praziquantel, during 1975~1983. The patients were 4 males and one female aged 10-64 years residing in Seoul or Wando-gun, Chollanam-do, Korea. All of them remembered the history of eating several kinds of raw marine fish and 2 persons said they ate the raw flesh of perch, Lateolabrax japonicus. Three among them experienced abdominal pain, 2 natural discharge of a chain of segments, but none revealed any sign of anemia. The average egg size in stool varied 59-67 x 41~48 micrometer according to cases. The eggs were characterized by ovoid to elliptical shape, terminal operculum, and distinct abopercular protuberance. One naturally discharged segment (30 cm) and 4 complete strobilae (320~680 cm) with scolices obtained after treatments were examined. The morphological characters of proglottids such as rosette-form uterus with 3~6 loops, vaginal pore included in the cirrus sac, separated seminal vesicle from cirrus sac etc. were all compatible with D. latum. These are the 7th~11th cases of D. latum infection proved by worms in Korea.

In order to obtain more specific antigenic preparation for the diagnosis of human paragonimasis, crude saline extract of whole worm (=PwWWE), secretory-excretory components (PwSEC) and secretion-excretion-free somatic extract (PwSM) of 12 week-old Paragonimus westermani were filtrated through Sephadex G-200 gel column. The adult Paragonimus worms were obtained from experimentally infected dogs. A total of 11 antigenic solutions was lyophilized or diluted to adjust protein content of 1 mg/ml. To evaluate the antigenicity of crude antigens and fractions, micro-ELISA was done with the sera from P. westermani infected cases, C. sinensis infected cases and non-infected control cases to detect Paragonimus specific IgG antibody. The results were as follows: When the PwWWE was filtrated through Sephadex G-200 gel, it was separated into three fractions; PwWWE Fr. 1, PwWWE Fr. 2 and PwWWE Fr. 3. The percentage of protein content was 28.0 %, 21.6 % and 50.4 % respectively. The PwSM was also separated into three fractions; PwSM Fr. 1, PwSM Fr. 2, PwSM Fr. 3 and their percentage of protein content was 41.3 %, 38.6 % and 20.1 %. However, the PwSEC showed different fractionation pattern; i.e. fraction 1 (=PwSEC Fr. 1) and 3 (PwSEC Fr. 3) without fraction 2. The percentage of protein content was 14.0 % in PwSEC Fr. 1 and 86.0 % in PwSEC Fr. 3. When the antigenicity of each Paragonimus crude antigen and fractionated antigen was evaluated for specific IgG antibody by micro-ELISA in 10 human paragonimiasis sera, PwSEC Fr. 1 was the most potent antigen showing the mean absorbance 1.98. The PwWWE Fr. 1, PwSEC, PwWWE were next to that; their mean absorbance were 1.72, 1.38 and 0.83, respectively. The antigenicity of fractions 2 and 3 was much weaker in binding specific IgG antibody. When the antigens were reacted in micro-ELISA with 10 human clonorchiasis sera, most antigens showed weak reactivity. Each fraction 1 of crude antigens reacted higher than other fractions or crude antigens; the mean absorbance was 0.17 in fraction 1, but in others the absorbances were about 0.06. With non-infected control sera, the result of micro-ELISA revealed almost same pattern with those of the clonorchiasis sera. From the above results, it became apparent that PwWWE Fr. 1, especially PwSEC Fr. 1 was the most potent antigen reacted with Paragonimus specifc IgG antibody.

The significance of Scotch-tape anal swab technique was evaluated in three communities of Korea, one in orphanage institute and two in rural populations, from November to December, 1975. Based on the epidemiological concept that the prevalence rate of Enterobius vermicularis infection in a community as "the proportion in the population who harboured E. vermicularis at certain point of time", the present authors treated the whole surveyed population with pyrantel pamoate disregard to the results of Scotch-tape anal swab and collected pinworms expelled in stool specimens during 2 consecutive days after the chemotherapy. Although the present authors could not collect the younger adult worms less than 3.54 mm in length after chemotherapy, the positive rates of pinworm collection in three surveyed communities were 80.6%, 92.5% and 91.4% respectively whereas the positive rates of single Scotch-tape anal swab were 52.4%, 53.6% and 57.1% respectively. These results denote that results of single anal swab do not represent the prevalence rate of Enterobius infection in a community. The results of successive two anal swabs and estimation of positivity in a population using Neyman's "Best asymptotically normal estimate" revealed 62.9% in the third trial group of this study and probability of finding eggs in single slide was 0.869. Comparing with the pinworm collection rate after the chemotherapy in this group the estimated positive rate was by far lower than that of pinworm collection(89.3%). The positive results of single anal swab did not correspond to the pinworm collection in average 9.1% of anal swab positive cases and the negative results did not correspond to pinworm collection in 81.3% of anal swab negative cases, when the data from three surveyed communities were amalgamated. These results must come from the principle of anal swab that detect the terminated parasitism. With rare exceptions, the anal swab negative cases harbour relatively fewer number of Enterobius than those of positive cases. And the mean number of E. vermicularis collected from anal swab negative cases was 9.1 whereas the number in anal swab positive cases was 31.5. By analyzing the data on the relationship between bathing interval and anal swab positive conversion, it was assumed that the positive rate of anal swab in a community represent the rate of appearance of gravid female Enterobius vermicularis through anus during approximately past two days prior to examination.

Parasitic disease is still important subject in the field of infectious diseases in Korea considering it's number and morbidity. Recently there was conspicuous reduction of parasitic disease in terms of soil-transmitted nematodiasis, but parasitism affecting organs other than intestinal tract is still a considerable problem. This survey covers the parasitic diseases cross-sectioned at a pathology laboratory of a referral hospital, trying to elucidate the significance of its relative frequency and also to describe some histopathological changes made by different parasites. Entire pathological materials of parasitic diseases, that were referred, examined and confirmed at the Department of Pathology, Seoul National University Hospital from 1968 to 1987, were used for the study. There was a total of 594 cases of tissue parasitic diseases. This number accounted for 0.33 per cent of total accessions of surgical pathology. There occurred average 30 cases of tissue parasitic disease each year at this Hospital. Protozoal diseases were constituted of 15 cases of amebiasis, 7 cases of leishmaniasis (imported) and 5 cases of Pneumocystis carinii infections. Among helminthic infections cysticercosis was the most common (425 cases), and was followed by paragonimiasis (35 cases), sparganosis (31 cases), clonorchiasis (32 cases) and ascariasis (16 cases). In addition there were 4 cases of anisakiasis, 2 cases of fascioliasis, 2 cases of echinococcosis (imported) and a case of strongyloidiasis and a case of metagonimiasis respectively. It is emphasized that imported parasitic diseases such as leishmaniasis and hydatid disease become steadily found nowadays. Schistosomiasis is another possible imported disease, but not found in this series. And certain cestodiasis particularly cysticercosis and sparganosis should be the subjects of epidemiologic re-evaluation in view of steady occurrence of their morbidity.

As epidemiological parameters of human paragonimiasis, the positive rates of intradermal test and the sputum/stool examination have long been employed in population surveys. However, both the specificity of the intradermal test and the sensitivity of sputum/stool 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 epidemiological 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-specific 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 case (5.7 %) were found positively reacted to VBS antigen of P. wetermani. 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 eggs 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 Clonorchis and of 128 intradermal test negative cases showed positive for Paragonimus- 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 size was over 13 mm 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 antibogy 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 handling of sera in micro-ELISA was considered another superiority as an epidemiologic tool.

The in situ posture of anterior body of Metagonimus yokogawai was observed in experimental metagonimiasis of dog. The metacercariae were collected from naturally infected sweetfish by peptic digestion; a total of 8 dogs was orally infected with 10,000 metacercariae respectively. Two dogs were killed on 3 days, 9 days, 4 weeks and 10 weeks after the infection. The postures of worms in histological section of small intestine and of whole worms collected from the fixed intestinal mucosa were examined by light and scanning electron microscope. The results were summarized as follows: The recovery rates of worms were 42.6% on 3 days, 55.0% on 9 days, 33.2% on 4 weeks and 9.8% on 10 weeks after the infection respecively. In histological sections of small intesine, most of worms were found at intervillous spaces as ovoid sections of posterior body. However, many worms, especially in 3 day-old worms, revealed protruded anterior body in glandular lumens of crypt. Some sections of anterior body were bifurcated or sacculated. The worms collected from fixed intestinal mucosa under dissecting microscope exhibited a variety of postures. Many worms showed flat shapes with a concavity or curvatures. However, in many worms, the anterior body made a single or multiple protrusions. By SEM observation of protruded anterior body, a longitudinal groove was found. The frequency of worms with protuded anterior body decreased in 9 days, 4 weeks and 10 weeks than in 3 day-old worms. The above findings indicated that the anterior body of juvenile and adult M. yokogawai protruded to lumens of glandular crypt by folding their lateral protions to make a reversible tubelike structure. Frequent multiple protrusions were considered to be made to adapt the microniche of glandular crypts of dog intestine.

To determine the source of Cysticercus-specific IgG antibody in cerebro-spinal fluid(CSF), paired samples of serum and CSF were collected from confirmed neurocysticercosis, other neurologic diseases and normal control. The antibody levels in serum and CSF were measured by enzyme-linked immunosorbent assay (ELISA). With the measurement of total protein, albumin and IgG concentration in serum and CSF, the contribution of IgG in CSF were calculated in transudation, exudation and intracranial synthesis using the formula of Tourtellotte and Ma (1978). Mean concentrations of total protein, albumin, IgG and proportional IgG levels in CSF by transudation, exudation and intracranial synthesis were elevated in neurocysticercosis. But only the intracranial synthesis of IgG showed a statistically significant correlation with the specific IgG antibody levels in CSF. In CSF from lateral ventricle in the 4th ventricular neurocysticercosis, the protein concentrations were normal and the specific antibody levels were negative. However, in consecutively secured lumbar CSF from the same patients, the former were increased and the latter were positive. These results indicated that, in neurocysticercosis, the specific IgG antibody in CSF was a local product of intracranial synthesis.

A case of ectopic fascioliasis involving cecum and ascending colon was reported. This case was a 19-year old Korean female who had a history of postprandial aggravation of intermittent abdominal pain of 3 weeks duration. She was presented with an abdominal mass in the right upper quadrant, for which an operation(right hemicolectomy) was performed. Whole cecum and ascending colon showed multifocal tunnel-like necrotizing granulmas with central cavitations. Numerous Charcot-Leyden crystals were seen along tracts of the worm. The lesion was distributed throughout the entire thickness of the wall. Parasitological examination confirmed the worm found in the intestinal wall to be juvenile form of Fasciola species. Possibilities were discussed on the localization of the fluke and the mode of infection of present case.

The authors examined 3,169 fecal specimens from inhabitants of seven localities such as City, Eups and Myons in Cheju Do on July 1970 with cellophane thick smear technique. The results were analysed and summarized as follows: 1) The overall egg positive rate of helminths was 82.2% and it was attributed to high rates of soil-transmitted helminths as in case of other parts in Korea. 2) The infection rates of each species were; A. lumbricoides 44.3%, T. trichiurus 65.6%, hookworm 1.5%, T. orientalis 0.8%, C. sinensis 0.2%, P. westermani 0.4%, M. yokogawai 0.9%, Taenia sp. 12.7% and H. nana 1.4%. 3) The infection rates of soil-transmitted helminths were relatively lower than those of mainland Korea especially in case of hookworm and T. orientalis. The proportion of unfertilized ova passers among the Ascaris infected case was 22.1%. 4) The ova of heterophyids, most probably Metagonimus yokogawai were detected in lower percentage but discovered throughout the localities surveyed and in all age groups. It is certainly presumed that Metagonimus infection is autochthonous. 5) The most interesting results were obtained in Taenia sp. infection and the higher rates were shown in rural area than in urbanized areas. The positive rates were within 5% in childhood and adolescence but abruptly increased up to 36.4 % in adults.

This study was undertaken to find out the possibility of iron-deficiency anemia by the intestinal blood loss in massive infection cases of T. trichiurus. Among the children of a community in which the whipworm infections were highly prevalent, 7 cases were selected whose E.P.G. of whipworm ova were more than 1,000. The hematological findings and estimated blood loss using (51)Cr were undertaken. The results could be summarized as follows: 1) The E.P.G. and E.P.D. of T. trichiurus ova in studied 7 cases were 10,500-37,200/gm of feces and 0.90-5.14 million/day respectively. 2) Findings of hematological examination were in lower limit of normal in hemoglobin content and hematocrit. And erythrocytes were neither microcytic nor hypochromic. Differential count of leucocytes showed persistently low grade of eosinophilia. 3) Serum iron content measured by modification of Barkan method showed subnormal value in 5 out of 7 cases. 4)Erythrocyte radioactivity half disappearance time(T(1/2)) and intestinal blood loss were estimated using (51)Cr-tagging erythrocytes. And the results showed that T(1/2) were shortened (13-19 days ) in all cases and the blood loss was 0.94-6.54 ml/day which were correlated with worm burden (E.P.D.) significantly. 5) From the above results, it could be concluded that intestinal blood loss of T. trichiurus heavy infection were actually occurred but the amount of losses were easily compensated.

Background Retrotransposons have been known to involve in the remodeling and evolution of host genome. These reverse transcribing elements, which show a complex evolutionary pathway with diverse intermediate forms, have been comprehensively analyzed from a wide range of host genomes, while the information remains limited to only a few species in the phylum Platyhelminthes. Results A LTR retrotransposon and its homologs with a strong phylogenetic affinity toward CsRn1 of Clonorchis sinensis were isolated from a trematode parasite Paragonimus westermani via a degenerate PCR method and from an insect species Anopheles gambiae by in silico analysis of the whole mosquito genome, respectively. These elements, designated PwRn1 and AgCR-1 – AgCR-14 conserved unique features including a t-RNATrp primer binding site and the unusual CHCC signature of Gag proteins. Their flanking LTRs displayed >97% nucleotide identities and thus, these elements were likely to have expanded recently in the trematode and insect genomes. They evolved heterogeneous expression strategies: a single fused ORF, two separate ORFs with an identical reading frame and two ORFs overlapped by -1 frameshifting. Phylogenetic analyses suggested that the elements with the separate ORFs had evolved from an ancestral form(s) with the overlapped ORFs. The mobile potential of PwRn1 was likely to be maintained differentially in association with the karyotype of host genomes, as was examined by the presence/absence of intergenomic polymorphism and mRNA transcripts. Conclusion Our results on the structural diversity of CsRn1-like elements can provide a molecular tool to dissect a more detailed evolutionary episode of LTR retrotransposons. The PwRn1-associated genomic polymorphism, which is substantial in diploids, will also be informative in addressing genomic diversification following inter-/intra-specific hybridization in P. westermani populations.