• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.75-82
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• 1992

The surface ultrastructure of Heterephyes nocens (Trematoda: Heterophyidae) was studied by scanning electron microscopy(SEM), The adult worms were recovered from experimentally infected cats and from a naturally infected patient. They were leaf-like, ventrally concave, and ovoid or lyriform in shape. Ciliated knob-like sensory papillae (type I) were observed in single or grouped forms on and around the oral sucker, whereas non-ciliated round swellings (type II papillae) were seen on the lip of the ventral sucker, The tegumental spines around the oral sucker were 5∼9 pointed, whereas those between the two suckers were 12∼17 pointed. yentrolaterally, three groups of 5∼6 type I papillae were located between the oral and ventral suckers, with single ones alternating between them. The genital sucker was protruded or depressed, depending on the contraction state of the nukes, and the gonotyl spine number ranged 50∼60. The number of tip points of tegumental spines was decreased posteriorly; finally they became 1∼3 pointed. On the dorsal surface, 4 groups of 4∼5 type I papillae were symmetrically located on both lateral sides, and the shape and distribution of tegumental spines were similar to those of the ventral surface. Although the tegumental ultrastructure of H. nocens was generally similar to those of other heterophyids, the genital sucker morphology including the number of gonotyl spines and/or the distribution pattern of tegumental spines and sensory papillae were suggested to be the characteristic features of H. necens.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.142-149
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• 1983

Epidemiological studies on the reinfetion pattern of Ascaris lumbricoides were undertaken by means of blanket mass chemotherapy and worm collection in a rural village in Korea, during 1977~1980. The study objectives were to determine the age (sex)-specific reinfection rate during 2, 4, 6 and 12 months through repeated mass chemotherapy with pyrantel pamoate, and to observe the familial aggregation tendency of the reinfected cases. The results obtained are as follows: 1. The age (sex)-reinfection curve revealed that the reinfection rate is much higher in younger individuals than in olders in all of 4 kinds of interval chemotherapy groups. The highest reinfection rate and the highest burden of reinfected worms were observed in preschool children, followed by primary school students. Such fluctuation in the age-specific reinfection rates was more pronounced in males than in females. 2. There was noted a significant tendency of familial aggregation among the reinfected cases. It is suggested that reinfection occurs never randomly but preferably to the members of certain household families. From these reinfection analyses, it is inferred that the principal mode of A. lumbricoides transmiSSIOn in the surveyed rural area is likely to be of 'dooryard type', in which case children and certain family members are more preferably reinfected. It is also suggested that the preschool children should be included in the primary targets of mass control programme.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.257-264
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• 1983

In order to obtain more specific antigenic preparation for the diagnosis of human paragonlmiasis, crude saline extract of whole worm (=PwWWE), secretory.excretory components (PwSEC) and secretion-excretion-free somatic extract (PwSM) of 12 week-old ParagoninBus westermani were filtrated through Sephadex G-200 gel column. The adult Paragonimus worms were obtained from expevimentally infected doge. A total of 11 antigenic solutions was Iyophilised or diluted to adjust protein content of 1mg/ml. To evaluate the antigenicity of crude antigens and fractions, micro-ELISA was done with the sera from P westermani in(ected cases, C. sinensis infected cases and non-infected control cases to detect Paragonimus specific IgG antibody. The results were as follows: 1. 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. 2. When the antigenicity of each Paragonimus crude antigen and fractionated antigen was evaluated for specific IgG aritibody 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. 3. 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. 4. With non-infected control sera, the result of micro-RLISA 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 Paragonisfaus specific IgG antibody.

• Parasites, Hosts and Diseases
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• v.27 no.4
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• pp.253-260
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• 1989

Metacercariae of the genus Stictodora encysted in the head tissue of Acanthogobius navimanus (the gobies) caught at Sachun-gun, Kyongnam Province, were identified to be Stictodora Zari Yamaguti, 1939 (Trematoda: Heterophyidae), a new parasite fauna in Korea. The metacercariae were 0.39∼,0.43 mm by 0.32∼0.35 mm in size, long elliptical, and with a thin and transparent cyst wall. Total 200 metacercariae were collected from 50 gobies. In order to obtain adult worms two kittens and a Puppy were infected each with 34∼100 metacercariae, and total 33 adults were recovered between the day 4 and day 8 post-infection. The S. sari adults measured 0.95∼1.18 mm long and 0.26∼0.32 mm wide and the eggs in uteri 0.028∼0.033 mm by 0.017∼0.020 mm. The most characteristic morphological feature of these flukes was the presence of a gonotyl and gonotyl spines arranged in two groups; densely crowded group of 30~40 spines and linearly-arranged one of 30∼40 spines, together of which made a comma(or reversed comma) shape along the lateral margin of the gonotyl. It has been proved by this study that 5. sari is distributed in southern coasts of Korea.

• Parasites, Hosts and Diseases
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• v.32 no.1
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• pp.35-42
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• 1994

This study was designed to evaluate the humoral immune reactions in clonorchiasis before and after praziquantel treatment. Rabbits were infected with 150 or 450 metacercariae, treated on 4 and 8111 months after infection, and observed for 13 months of posttreatment. Infection controls were maintained for 22 months. Antigen was the metabolic product of worms incubated in physiologic saline. The immune reactions of anti-clonorchis IgG were observed using SDS-PAGE/immunoblot. During the Infection and Posttreatment, the antigenic Proteins of 66, 63, 54, 52, 50,47,42, 40, 38, 34,33,30, 27, 25, 23, 20, 19, 18, 17, 16, 15, 14, 13, 12.5 and 11.5 kDa were detected. Of them, 33,27, 13, and 12.5-kDa antigens were highly antigenic and observed predominently in infection controls. After the treatment, 13 and 12.5-kDa antigens faded in 6 months after the second treatment, but 33 and 27-kDa antigens were detected until 13 months of posttreatment. The results clearly demonstrate that 13 and 12.5-kDa antigens represent attenuated host immune reactions by praziquantel treatment. As the 12.5-kDa antigen had a large amount of protein in SDS-PAGE, it was designated as'K2-Ag'of C. sinenis.

• Journal of Veterinary Clinics
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• v.26 no.4
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• pp.311-316
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• 2009

The purpose of this meta-analysis was to collect data from the literatures reporting prevalence of canine heartworm (HW) infection in an effort to emphasize the preventive importance of the disease and to serve as baseline data for further studies related to the disease management. Fourteen studies regarding the prevalence of HW infection published during the 1996-2007 were identified using the meta-analytic approach, involving a total of 1,790 cases by microfilarial test and 3,277 cases by enzyme-linked immunosorbent assay (ELISA) antigen test for adult worms. Data analysis was performed separately for pet and military dogs. The overall apparent prevalence of HW infection in pet dogs by microfilarial test and ELISA was 11.7% (183/1,563) and 16.5% (379/2,302), respectively (p < 0.001). No significant difference in prevalence by microfilaria and ELISA was observed between sexes whether assessed by data separately or pooled together. Compared to before 2000, the prevalence by microfilaria after 2000 has increased from 2.5% to 13.1% (p < 0.001), and the rate of adult worm has also increased from 9.9% to 20.3% (p < 0.001). The prevalence determined by ELISA was found to increase with age: 20.7% (n = 1,003) of dogs older than 2 years were positive, compared with 5.0% of dogs (n = 701) under 2 years of age (p < 0.001). Also, outdoor dogs showed significantly higher prevalence than indoor dogs (37.9% versus 3.4%; p < 0.001). For military dogs, the overall prevalence was 38.3% (87/227; 95% CI, 32.1 - 44.7%) by microfilarial test and 38.5% (375/975; 95% CI, 35.4 - 41.6%) by ELISA. This rate was significantly higher than that of pet dogs (p < 0.001). Occult infection rate of 37.5% and 66.7% was found in pet and military dogs, respectively.

• Journal of Aquaculture
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• v.19 no.1
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• pp.19-24
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• 2006

The objective of this study was to develop an efficient control method for the Alella macrotrachelus parasitic cultured black porgy, Acanthopagrus schlegeli utilizing the superior osmoregulatory ability of the host fish. The average number of the parasites on a fish was 5 worms (all female), which were attached to the cartilage of gill filament by their bulla. Morphologically, the parasite was tripartite with each length of $1822.1{\pm}521.5{\mu}m$ for the trunk $1825.0{\pm}495.8{\mu}m$ for the cephalothorax, and $134.2{\pm}43.1$ for the bulla. In histological observations, it was found that the female parasite took gill lamellae. Damage and loss of gill lamellae by the parasite caused hemorrhage and anemia in the fish. All parasites died within 48 hours by osmotic shock of freshwater or $5{\sim}15\%_{\circ}$ seawater treatment. These results suggest that Alella macrotrachelus could be controled by hyposmotic treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.1
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• pp.7-14
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• 1974

1. Stylochus ijimai spawns from May to October with peak spawning from July to September, P. obscurus spawns from June to October with peak spawning from July to September. 2. S. ijimai spawns approximately 96,000-132,000 eggs by one spawning. 1. Just after spawnings, the eggs of S. ijimai were $102\mu$ in diameter, and those of P. obscurus were $108\mu$. 4. S. ijimai and P. obscurus have simple eggs. S. ijimai develop indirectly having Gotte larvae, while P. obscurus develop directly. 5. These two species show very similar patterns of early developments from maturation division of eggs to the gastrula stage. 6. The zygots of S. ijimai reaches mesentoblast stage 48 hours after fertilization, and Gotte larvae hatch out 7 days after fertilization. The zygots of P. obscurus reaches mesentoblast stage 72 hours after fertilization, and juveniles hatch out 14 days after fertilization. 7. S. ijimai, have 14 days of planktonic larvae stages bearing strong phototacic behavior : P. obscurus have 7 days of planktonic life without phototacic behavior. 8. Newly hatched larvae of S. ijimai and P. obscurus are $138\mu\;and\;170\mu$ in length respectively. The early creeping forms of S. ijimai and P. obscurus are $152\mu\;and\;185\mu$ in length respectively. 9. In the early creeping stage S. ijimai are characterized by testing processes and flattening of the body. In the same stage P. obscurus lost 2 eye-spots in the cerebral area. 10. The early creeping larvae of these two species were found only in mud-flat substrates.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.1-6
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• 1985

Five cases infected with Rhabditis sp. were detected in a survey to examine the stool specimens from rural primary school children. A large number of the larvae of Rhabditis sp. detected by the direct cellophane thick smear were cultured by the alter paper method. The eBamination was carried out in April through June, 1980 in Tangjeong-Myon, Ahsan.Gun, and in September 1983 in Sandong-Eup, Yeongwol-Gun. The results obtained in this study were as follows: 1. Prevalence: Out of 925 children, 5(0.54%) children were found to be positive. The number of the detected larvae was 110/0.1gm of feces in case 1, 35 in case 2, 130 in case 3, 86 in case 4 and 62 in case 5. 2. Larvae: The larvae were prepared by means of the direct fecal smear and measured by a micrometer equipped in the microscope. Twelve (12) through 15-day old larvae in culture were $197.1{\mu}{\textrm{m}}$ long in average, and the maximum size of the matured stage larvae was $884.0{\times}25.9{\mu}{\textrm{m}}$. However, the length variation was ranged as 173.0 to $884.0{\mu}{\textrm{m}}$. 3. Adults: The size of clubbed adult female was $1, 357{\mu}{\textrm{m}}(1, 176~1, 419)$ in length and $80{\mu}{\textrm{m}}(79~82)$ in width. Length of buccal cavity was $33{\mu}{\textrm{m}}$. A long cylindrical esophagus($273{\mu}{\textrm{m}}$) of the worms with a valved posterior cardiac bulb and with median bulbar swelling was morphologically indicated. Ditance from mouth to vulva was occupied 58% of body length. Male worm was $1, 006{\mu}{\textrm{m}}(890~1, 148)$ in length and $49{\mu}{\textrm{m}}(48~49)$ wide. Caudal alee of bursa and spicules ($75{\mu}{\textrm{m}}$ in length) were well developed. 4. Eggs: The oval shaped eggs in the female uterus, when cultured, were $66{\times}56{\mu}{\textrm{m}}$ in sixte, and the eggs laid by the adult could not be detected. So, reproduction might be thought to be ovoviviparity. 5. The five cases were re-examined during the period from the 1st to the 3rd week after stool examinations, but Rhabditis sp. were detected again in 4 cases in 1st week. When they were examined in 3rd week, larvae could not be detected. So, it was thought that the infection of Rhabditis sp. to humans was facultative.

• Animal Systematics, Evolution and Diversity
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• v.16 no.1
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• pp.125-131
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• 2000

This paper deals with the morphology and taxonomy of the first reported species of echinostome belonging to the genus Himasthla Dietz, 1909, found from dunlins (Calidris alpina sakhalina) in Korea. Birds were captured with mist-nets at the tidal flat of Yeochari, Kanghwa-gun, Kyunggi-do, Korea. The worms were removed from avian intestines in physiological saline, fixed, acetocarmine stained and observed. Himasthla kusasigi Yamaguti, which was found in 1939, was characterized morphologically by a long and slender body (5.27 mm in length), besetting with spines and reniform head collar (0.27 mm) in a form of a single and uninterrupted row of 31 spines. The oral sucker (0.057$\times$0.0684 mm) is smaller than the ventral sucker (0.35$\times$0.29 mm). The ventral sucker was close to the anterior extremity of the body. The worm had two elliptical testes (anterior 0.47$\times$0.30 mm, posterior 0.59$\times$0.27 mm). The testes were close to the posterior end of the body. The uterus was very long, winding and extending through at least two thirds of the body length. The ovary (0.13$\times$0.14mm) was round and small. Below the ovary, a round and small seminal receptacle was found.