• Parasites, Hosts and Diseases
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• v.32 no.3
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• pp.163-170
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• 1994

An epidemiological survey was performed to know the infection status of heterophyid fluke metacercariae in the brackish water fishes purchased from a local market in Haenam-gun, Chollanam-do, Korea from November to December, 1991. A total 20 out of 30 shads (Konosiw punctatus) examined were infected with the metacercariae of H. continua (average number of larvae per an infected fish: 2.71). Of 20 perches (Lateolabroxjoponicurs), 19 were Infected with the metacercariae of H. continua (average number per an infected fish: 17.21. Of 30 mullets (Mugil cepholus) examined, 11 were Infected with the metacercariae of H. nocens (average number per an Infected fish: 51.5), 10 mullets harboured 31 and 349 metacercariae of f summa and 5. lucatum respectively. Of 30 gobies (Acnnthogobin jlcvimonus) examined, 3 were infEcted with the metacercariae of H. nucens (average number per an Infected fish: 32.0), 8 with those of H. continua (average number per an infected flesh: 12.6) and 3 with those of 5. JuscntuwL From the above results, It has been confirmed that the brackish water Ash from Haenam-gun, Chollanam-do are infected with numerous metacercarlae of H. nocens, H. continua, P. summo and S. fuscatum.

• Parasites, Hosts and Diseases
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• v.33 no.3
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• pp.187-194
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• 1995

The present study aims to observe changing patterns of serum antibody to hleumuvstis calinii in normal rats of different ages and in immunosuppressed rats. The serum IgG antibody was observed by immunoblotting with crude antigen of f carinii which were purified from the lungs of infected rats. The crude antigens separated in SDS-PAGE resolved more than 20 protein bands from 20 to 200 kDa. Of them,40-45, 50-55, 116 and 200 kDa bands were major antigens of R cori.nii. Most of the normal rats of up to 4 weeks had the antibodies reacting the 4 bands, but none of 8-week-old rats revealed the specific antibody. After the rats grew for 40 weeks, all were found to have the antibody in their serum. Same pattern of serum antibody level by age was found in ELISA. When immunosuppressed rats became heavily infected, the antibody in their serum decreased distinctively. The present results suggest that antibodies in normal newborn rats are transferred from their mother and lowered up to 8 weeks. Thereafter, the levels of the antibodies begin to increase by natural exposure to R cnrinii. It was also confirmed that the intensity of P cnrinii infection is inversely related with levels of serum antibodies.

• Parasites, Hosts and Diseases
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• v.32 no.3
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• pp.177-184
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• 1994

Nine rabbits were fed with Clonorchis sinenis metacercariae (MC) and the blood samples chronologically obtained were analyzed biochemically. Rabbits Infected by less than 100 flukes were grouped into Group I, and by 100-250 flukes into Group II. The serum level of alanine amlnotransferase (ALT) was increased from 3 weeks after the Infection of the metacercariae (AIM) and showed a peak at 8 weeks, and decreased from 12 weeks ASM. The serum level of aspartate aminotransferase (AST) was raised to $92.3{\;}{\pm}{\;}65.4{\;}U/L$ at 3 weeks AIM and stayed high until 8 weeks, then lowered thereafter. The serum level of ${\gamma}-glutamyl$ transpeptidase (${\gamma}-GT$) was increased rapidly to the highest value ($18.9{\;}{\pm}{\;}14.6{\;}U/L$) at 16 weeks ASM, and decreased to the control level after 20 weeks. The serum level of alkaline phosphatase (ALP) was headed down from the early infection to 52 weeks AIM. The serum cholesterol level was increased from 8 weeks and reached at a peak 16 weeks AIM, and decreased thereafter to the control level. It is suggested that serum ALT, AST, ALP and ${\gamma}-GT$ tests be useful to diagnose the early infEction of C. sinensis.

• Parasites, Hosts and Diseases
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• v.33 no.3
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• pp.195-200
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• 1995

The presence of biological response modifiers (BRMI-like effect was confirmed in peritoneal exudate (PE) of ToxopLnsmo gondii-infected ICR mice which inhibited Concanavalin A (Con A)-induced peritoneal Iymphocyte (PL) proliferation. During 5 days of PL incubation with $10{\;}\mu\textrm{g}/ml$ Con A with or without PE, 3H-thymidine uptake was measured for the last 24 hrs. Compared to uninduced control, PL proliferated by 7.3-fold with Con A induction_ When PE of infected mice was added, PL proliferation was inhibited by $74.0{\;}{\pm}{\;}11.9%$ whereas inhibition by PE of normal mice was $16.4{\;}{\pm}8.3%$. Inhibitory effect of PE increased exponentially from 3 days up to 4-5 days of survival after the infection. Inhibitory activity of PE was decreased concentration-dependently. Also the inhibition was diminished when the PE was treated with heat of $95^{\circ}C$ for 10 min orprecipitated with 10% trichloroacetic acid (TCA). In SDS-PAGE of PE, many minor bands appeared newly. Heat-labile protein molecule in PE exerted inhibitory activity to Con A- induced Iymphocyte proliferation.

• Parasites, Hosts and Diseases
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• v.32 no.3
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• pp.195-200
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• 1994

Malaria is estimated to have a worldwide incidence of more than 100 million clinical cases and approximately 1 miuion deaths per year. Korea, although previously tnlown as an endemic area of tertian malaria (Pzosmonin vivax), has been considered free from malaria as there had been no report on indigenous cases since 1984. Recently, however, we experienced an indigenous case of P. viuax infection in a young man who had never been abroad. The patient was a 23-year-old Korean soldier with 18-day history of recurrent fever and chill lasting 4 to 8 hours on alternative days since mid-July 1993. He had lived in Changwon, Hyongsangnam-do, before entering barracks located in Paiu-gun, Kyonggj-do on Jne 1992, and had never been out of Korea. He had no history of blood transfusion nor parenteral use of drugs. The peripheral blood smears showed typical ring forms, trophozoites, and gametocytes of p. uiuox, in addition to mild anemia and thrombocytopenia. After confirmation of the diagnosis, he was treated with hydroxychloroquine and primaquine. Follow-up blood smears no more revealed malaria parasites. It is not certain whether the present case is due to a resurgence of indigenous malaria or a secondary infection from introduced mnuia. Whichever the source of infection the domestic occurrence of mnuia cycle in Korea should be a warning sign in public health point of view.

• Parasites, Hosts and Diseases
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• v.33 no.3
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• pp.211-218
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• 1995

To clarify the correlation of the proteinase activity with pathogenicity of Clonorrhis sinensis, the proteinase activity either in excretory-secretory products (ESP) or in crude extracts of adult C. sinensis was examined. Substrate gel electrophoresis of the ESP and crude extracts revealed four distinct enzyme bands, which were differently inhibited by the specific proteinase inhibitors. The proteinase of the ESP with molecular mass of 24 kDa, was purified 23-fold with 14.5% yield by spectra gel ACA 44 gel filtration. It exhibited optimal pH at 7.5 in sodium phosphate (0.1 M). Its activity was inhibited specifically by N-ethylmaleimide (NEMI and antipain whereas potentiated 1.9 folds in the presence of 5 mM dithiothreitol (DTT). Cytotoxicity of the proteinase increased in a dose- dependent manner up to 120 ㎍/ml while reduced by NEM and antipain, indicating that cysteine proteinase was responsible for the cytotoxicity. This result shows that the 24 kDa cysteine proteinase is deeply correlated with the pathogenicity of C. sinensis infection.

• Parasites, Hosts and Diseases
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• v.32 no.3
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• pp.171-176
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• 1994

Wistar rats were induced of Pneumowstis cayinii infection by injection with methyl-prednisolone to correlate the cyst counts and numbers of nuclei. Seven sections of the lungs were examined by impression smears and also whole lung homogenates were screened for nucleus counting for each rat. At the first week of the experiment, all of the Impression smears except one were cyst negative but trophic forms were counted around 106. At the third week, the cysts appeared one per 20 Immersion oil lens fields. The nuclei were on the order of 107 at this period, and this amount of Pc is regarded as the limit of cyst detection on Impression smears. When the nuclei were over 109 in the lungs, the cysts were counted about 50 in 20 microscopic fields. The organisms were distributed in the lungs without any predilection focus. The present data suggest that the trophic forms, proliferate first and the cysts appear later in the lungs.

• Parasites, Hosts and Diseases
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• v.49 no.3
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• pp.331-335
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• 2011

A tick survey was conducted to determine the relative abundance and distribution of ticks associated with selected mammals in the Republic of Korea (ROK) during 2008-2009. A total of 918 ticks were collected from 76 mammals (6 families, 9 species) captured at 6 provinces and 3 Metropolitan Cities in ROK. Haemaphysalis longicornis (54.4%) was the most frequently collected tick, followed by Haemaphysalis flava (28.5%), Ixodes nipponensis (7.6%), Ixodes pomerantzevi (4.8%), Ixodes persulcatus (4.6%), and Haemaphysalis japonica (0.1%). Adults (57.0%) and nymphs (28.7%) of Ixodes and Haemaphysalis spp. were collected most frequently from medium or large mammals in this survey, while few larvae (14.3%) were collected. Hydropotes inermis was the most frequently captured mammal (52.6%), with a 16.4 tick index and 5 of 6 species of ticks collected during this survey. H. longicornis (69.7%) was the predominant tick collected from H. inermis, followed by H. flava (22.2%), I. persulcatus (6.1%), I. nipponensis (1.8%), and H. japonica (0.2%).

• Parasites, Hosts and Diseases
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• v.53 no.2
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• pp.155-162
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• 2015

Toxoplasma gondii is a protozoan parasite with a broad range of intermediate hosts. Chickens as important food-producing animals can also serve as intermediate hosts. To date, experimental studies on the pathogenicity of T. gondii in broiler chickens were rarely reported. The objective of the present study was to compare the pathogenicity of 5 different T. gondii strains (RH, CN, JS, CAT2, and CAT3) from various host species origin in 10-day-old chickens. Each group of chickens was infected intraperitoneally with $5{\times}10^8$, $1{\times}10^8$, $1{\times}10^7$, and $1{\times}10^6$ tachyzoites of the 5 strains, respectively. The negative control group was mockly inoculated with PBS alone. After infection, clinical symptoms and rectal temperatures of all the chickens were checked daily. Dead chickens during acute phage of the infection were checked for T. gondii tachyzoites by microscope, while living cases were checked for T. gondii infection at day 53 post-inoculation (PI) by PCR method. Histopathological sections were used to observe the pathological changes in the dead chickens and the living animals at day 53 PI. No significant differences were found in survival periods, histopathological findings, and clinical symptoms among the chickens infected with the RH, CN, CAT2, and CAT3 strains. Histopathological findings and clinical symptoms of the JS (chicken origin) group were similar to the others. However, average survival times of infected chickens of the JS group inoculated with $5{\times}10^8$ and $1{\times}10^8$ tachyzoites were 30.0 and 188.4 hr, respectively, significantly shorter than those of the other 4 mammalian isolates. Chickens exposed to $10^8$ of T. gondii tachyzoites and higher showed acute signs of toxoplasmosis, and the lesions were relatively more severe than those exposed to lower doses. The results indicated that the pathogenicity of JS strain was comparatively stronger to the chicken, and the pathogenicity was dose-dependent.

• Parasites, Hosts and Diseases
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• v.54 no.5
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• pp.645-652
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• 2016

Toxocara vitulorum has been rarely reported in yaks at high altitudes and remote areas of Sichuan Province of Tibetan Plateau of China. The current study was designed to investigate the prevalence, associated risk factors, and phylogenetic characteristics of T. vitulorum in yak calves on the Qinghai Tibetan plateau. Fecal samples were collected from 891 yak calves and were examined for the presence of T. vitulorum eggs by the McMaster technique. A multivariable logistic regression model was employed to explore variables potentially associated with exposure to T. vitulorum infection. T. vitulorum specimens were collected from the feces of yaks in Hongyuan of Sichuan Province, China. DNA was extracted from ascaris. After PCR amplification, the sequencing of ND1 gene was carried out and phylogenetic analyses was performed by MEGA 6.0 software. The results showed that 64 (20.1%; 95% CI 15.8-24.9%), 75 (17.2; 13.8-21.1), 29 (40.9; 29.3-53.2), and 5 (7.6; 2.5-16.8) yak calves were detected out to excrete T. vitulorum eggs in yak calve feces in Qinghai, Tibet, Sichuan, and Gansu, respectively. The present study revealed that high infection and mortality by T. vitulorum is wildly spread on the Qinghai Tibetan plateau, China by fecal examination. Geographical origin, ages, and fecal consistencies are the risk factors associated with T. vitulorum prevalence by logistic regression analysis. Molecular detection and phylogenetic analysis of ND1 gene of T. vitulorum indicated that T. vitulorum in the yak calves on the Qinghai Tibetan plateau are homologous to preveiously studies reported.