• Parasites, Hosts and Diseases
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• 제49권3호
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• pp.235-243
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• 2011

In order to get a better understanding of the role of protease-activated receptor 2 (PAR2) in type 2 helper T (Th2) cell responses against Trichinella spiralis infection, we analyzed Th2 responses in T. spiralis-infected PAR2 knockout (KO) mice. The levels of the Th2 cell-secreted cytokines, IL-4, IL-5, and IL-13 were markedly reduced in the PAR2 KO mice as compared to the wild type mice following infection with T. spiralis. The serum levels of parasite-specific IgE increased significantly in the wild type mice as the result of T. spiralis infection, but this level was not significantly increased in PAR2 KO mice. The expression level of thymic stromal lymphopoietin, IL-25, and eotaxin gene (the genes were recently known as Th2 response initiators) of mouse intestinal epithelial cells were increased as the result of treatment with T. spiralis excretory-secretory proteins. However, the expression of these chemokine genes was inhibited by protease inhibitor treatments. In conclusion, PAR2 might involve in Th2 responses against T. spiralis infection.

• Parasites, Hosts and Diseases
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• 제53권2호
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• pp.201-207
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• 2015

This study aimed to investigate the infection status, worm development, and phylogenetic characteristics of the intestinal trematode, Stellantchasmus falcatus. The metacercariae of S. falcatus were detected only in the half-beak (Dermogenus pusillus) out of the 4 fish species examined. Their prevalence was 90.0%, and the intensity of infection was 919 metacercariae on average. Worms were recovered from 33 (97.1%) of 34 chicks that were experimentally infected with 200 S. falcatus metacercariae each, and the average recovery rate was 43.0%. The body size and inner organs of S. falcatus quickly increased in the experimental chicks over days 1-2 post-infection (PI). In addition, ITS2 sequence data of this parasite were analyzed to examine the phylogenetic relationships with other trematodes using the UPGMA method. The results indicated that the ITS2 sequence data recorded from trematodes in the family Heterophyidae appeared to be monophyletic. This study concluded that D. pusillus serves as a compatible second intermediate host of S. falcatus in Thailand and that S. falcatus can develop rapidly in the experimental chicks. Data collected from this study can help to close the gap in knowledge regarding the epidemiology, biology, and phylogenetic characteristics of S. falcatus in Thailand.

• Parasites, Hosts and Diseases
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• 제53권5호
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• pp.545-551
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• 2015

Schistosomiasis is one of the important neglected tropical diseases (NTDs) in Tanzania, particularly in Lake Victoria zone. This baseline survey was a part of the main study of integrated control of schistosomiasis and soil-transmitted helminths (STHs) aimed at describing morbidity patterns due to intestinal schistosomiasis among adults living on Kome Island, Sengerema District, Tanzania. Total 388 adults from Kome Islands (about 50 people from each village) aged between 12 and 85 years, were examined by abdominal ultrasound according to the Niamey protocol. Liver image patterns (LIPs) A and B were considered normal, and C-F as distinct periportal fibrosis (PPF). The overall prevalence of PPF was 42.2%; much higher in males than in females (47.0% in male vs 34.4% in females, P=0.007). Abnormal increase of segmental branch wall thickness (SBWT) and dilated portal vein diameter (PVD) were also more common in males than in females. Hepatosplenomegaly was frequently encountered; 68.1% had left liver lobe hepatomegaly and 55.2% had splenomegaly. Schistosoma mansoni-related morbidity is quite high among adults in this community justifying the implementation of integrated control strategies through mass drug administration, improved water supply (pumped wells), and health education that had already started in the study area.

• Parasites, Hosts and Diseases
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• 제46권3호
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• pp.133-137
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• 2008

This study was performed to investigate prevalence of clonorchiasis among the inhabitants living in villages along the 4 major rivers, Nakdong-gang (= river), Seomjin-gang, Youngsan-gang, and Guem-gang in southern Korea. From January to December 2006, a total of 24,075 stool samples (1 sample per an inhabitant) were collected in 23 localities and examined by the formalin-ether sedimentation technique. Of the inhabitants examined, 3,441 (14.3%) were found to harbor various types of intestinal parasite eggs, cysts or larvae. Numbers of infected people were 2,661 (11.1%) for Clonorchis sinensis, 431 (1.8%) for heterophyids, 226 (0.9%) for Entamoeba spp., 57 (0.2%) for Giardia lamblia, 30 (0.1%) for Trichuris trichiura, and 18 (0.07%) for echinostomes. Prevalence rates of clonorchiasis according to the river basin were 17.1% in Nakdong-gang, 11.2% in Seomjin-gang, 5.5% in Youngsan-gang and 4.6% in Guem-gang. Of the 2,661 C. sinensis egg-positive cases, 57.7% was male. The present findings suggest that clonorchiasis is still highly prevalent among inhabitants in the riverside areas of southern Korea, and it is necessary to implement a systematic control program in the endemic areas.

• Parasites, Hosts and Diseases
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• 제58권6호
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• pp.647-652
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• 2020

Clonorchis sinensis is the most common fish-borne intestinal parasite in Korea. The aim of the present investigation was to survey the status of C. sinensis infection and analyze associated risk factors in residents of Haman-gun, Gyeongsangnam-do. A total of 5,114 residents from 10 administrative towns/villages voluntarily agreed to participate in the study, which comprised fecal examination, a questionnaire survey for risk factors, ultrasonography, and enzyme-linked immunosorbent assay for cancer biomarker detection in the blood. We detected C. sinensis eggs in 5.3% of the subjects. By region, Gunbuk-myeon had the highest number of residents with C. sinensis eggs. The infection rate and intensity were higher in male than in female residents. Based on the risk factor questionnaire, infection was highly associated with drinking, a history of C. sinensis infection, and the practice of eating of raw freshwater fish. Extension of the bile duct, infection intensity, and cancer biomarker detection significantly correlated with the presence of eggs in the study population. In conclusion, the development of feasible, long-term control policies and strategies for the elimination of C. sinensis in Korea is still required.

• Parasites, Hosts and Diseases
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• 제33권4호
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• pp.357-364
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• 1995

이질아메바에 의한 장염 환자의 조직 또는 이질아메바를 실험적으로 감염시킨 동물의 조직 검사에서 호중구의 침윤이 특징적으로 관찰된다. 그러나 이와같은 호중구의 침윤을 설명할 수 있는 기전에 대한 연구는 매우 미흡하다. 따라서 본 연구자들은 아메바 감염 초기에 인체 대장상피 세포에서 interleukin-8(IL-8)이 유도되어 호중구 침윤과 같은 염증반응이 유발될 것이라는 가설을 설정하였다. 이를 위하여 인체 대장상피세포주인 HT-29에 이질아메바 영양형을 실험적으로 노출시킨 뒤 발현되는 IL-S mRNA를 역전사 중합효소법(reverse transcriptional polymerase chain reaction, RT-PCR)으로 검사함과 퐁시에 발현된 IL-8 mRNA를 인공적으로 합성시킨 표준 RNA와 RT-PCR법을 이용하여 정량하였다. 실험 결과 이질아메바 영양형에 노출된 30분 후 부터 IL-8 mRAN가 발현되기 시작하였다 그리고 그 발현 분자수는 노출 시간의 증가에 따라 계속 증가하여 3시간 대에는 $3.1{\;}{\times}{\;}10^7{\;}molecules/\mu\textrm{g}$ total RNA를 나타내었다. 동시에 IL-8 mRNA의 발현은 노출시킨 이질아메바 영양형의 수에 비례하였다. 즉 HT-29/아메바 영양형의 비율이 10:1인 경우 IL-8 mRNA의 발현 분자수는 $1.2{\;}{\times}{\;}10^7{\;}molecules/\mu\textrm{g}$ total RNA로 나타났다. 이와같은 IL-8 mRNA의 발현은 IL-8 단백질 분비로 이어짐을 ELISA 검사로 확인할 수 있었다. 한편 이질아메바 파쇄액(Iysate)도 대장상피세포군인 Caco-2에서 IL-8 mRNA발현을 유도하였다. 결론적으로 본 실험은 이질아메바 감염 초기에 대장상피세포로 부터 IL-8이 발현되며, 이에 의하여 염증반응이 촉발될 가능성이 있음을 시사해 준다.

• Parasites, Hosts and Diseases
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• 제58권3호
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• pp.237-247
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• 2020

Dendritic cell is one of the first innate immune cell to encounter T. gondii after the parasite crosses the host intestinal epithelium. T. gondii requires intact DC as a carrier to infiltrate into host central nervous system (CNS) without being detected or eliminated by host defense system. The mechanism by which T. gondii avoids innate immune defense of host cell, especially in the dendritic cell is unknown. Therefore, we examined the role of host PI3K/AKT signaling pathway activation by T. gondii in dendritic cell. T. gondii infection or T. gondii excretory/secretory antigen (TgESA) treatment to the murine dendritic cell line DC2.4 induced AKT phosphorylation, and treatment of PI3K inhibitors effectively suppressed the T. gondii proliferation but had no effect on infection rate or invasion rate. Furthermore, it is found that T. gondii or TgESA can reduce H₂O₂-induced intracellular reactive oxygen species (ROS) as well as host endogenous ROS via PI3K/AKT pathway activation. While searching for the main source of the ROS, we found that NADPH oxidase 4 (NOX4) expression was controlled by T. gondii infection or TgESA treatment, which is in correlation with previous observation of the ROS reduction by identical treatments. These findings suggest that the manipulation of the host PI3K/AKT signaling pathway and NOX4 expression is an essential mechanism for the down-regulation of ROS, and therefore, for the survival and the proliferation of T. gondii.

• 대한의생명과학회지
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• 제11권3호
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• pp.259-266
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• 2005

Mast cells and goblet cells have been known to protect the host against parasites. In this study, we examined the response of the mast cells and goblet cells over a period of 6 weeks in the duodenum, jejunum and ileum of C3H/HeN and C57BL/6 mice infected with Echinostoma hortense (E. hortense). In addition, we investigated whether the worm recovery rate of uninfected mice (the control group) or E. hortense-infected mice (the experimental group) was associated with the number of mast cells and goblet cells. The worm recovery rate was higher in the C3H/HeN mice than in the C57BL/6 mice. The number of goblet cells significantly increased in the experimental group of the C3H/HeN and C57BL/6 mice compared with the control group of both strains (P<0.005). Worm recovery peaked 3 weeks after the infection of the C57BL/6 mice and at 2 weeks after the infection of the C3H/HeN mice, and it was higher in the duodenum than in the jejunum and ileum. However, the infected site in the intestine had no relation with worm expulsion. In the C3H/HeN and C57BL/6 mice, the number of goblet cells in the experimental group was significantly higher than that in the control group (P<0.005). The number reached a peak 2 weeks after the infection and it even increased in duodenum, jejunum and ileum. The increased number of goblet cells was retained 6 weeks after infection. The number of goblet cells was higher in the C3H/HeN mice than in the C57BL/6 mice (P<0.01). These results indicate that goblet cells are related with the worm expulsion. Furthermore, immunohistostaining of the antral intestinal walls for lectin showed the significant increase of the number of goblet cells in the experimental group (P<0.001). The high infection rate in the duodenum was found during the early infection. An increased infection rate in the jejunum and ileum was found 3 weeks after infection and the infection rate was higher in the C3H/HeN mice than in the C57BL/6 mice. Taken together, the present study indicates that goblet cells, rather than mast cells, may play critical roles in parasite expulsion.

• Parasites, Hosts and Diseases
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• 제36권3호
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• pp.155-162
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• 1998

우리 나라 일부 해안 지역의 장내 기생충 감염현황을 파악하기 위해 전북 부안군 주민 153명 및 경남 사천군 주민 138명의 대변을 수집하여 셀로판 후층 도말법 및 포르말린-에테르 침전법을 실 시하였다. 전북 부안군의 기생충 감염률은 21.5% (33/153명)이었으며, 감염 기생충별 양성률은 이형흡충류 17.6%, 간흡충 2.6%, 회충 0.7%, 람블편모충 2.6%, 대장아메바 0.7% 및 작은와 포자충 0.75이었다. 경남 사천군의 기생충 감염률은 39.1% (54/138명)로서 이형흡충류 18.8%, 간흡충 12.3%, 편충 2.2%, 람블편모충 2.2%, 대장아메바 5.0%, 이질아메바 0.7%, 왜소아메바 3.6% 및 작은와포자충 4.3%의 양성률을 보였다. 부안군에서 이형흡충란 양성자 22 명으로부터 회수한 충체는 유해이형흡충이 총 3,284마리 (평균 149.3마리)였으며 표주박이형흡 충, 수세미이형홉충, 요코가와흡충, 미야타흡충, 자루이형흡충, 참굴큰입흡충, 긴이형흡충 및 Aconthopowphium kurogamo등이 중복 감염되어 있었다. 사천군에서 이형흡충란 양성자 중 6명으로부터 회수한 충체는 요코가와흡충이 총 3,007마리 (평균 501.2마리)였으며 유해이형흡충, 수 세미이형흡충, 긴이형흡충, 갈매기이형흡충 등의 이형흡충류가 중복감염되어 있었다. 이상의 결과로 우리 나라 남해 및 서해안 지역 주민들에서 담수어 또는 반염수어의 생식 습관으로 장내 흡충, 특히 이형흡충류의 유행이 지속되고 있음을 확인하였다.

• Applied Microscopy
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• 제38권1호
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• pp.11-19
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• 2008

전해알칼리환원수가 동물의 면역에 미치는 영향을 알아보고자 본 실험을 수행하였다. 소장에서 기생하는 호르텐스극구흡충(Echinostoma hortense)을 이용하여 C57BL/6 생쥐 소장과 혈액에서의 면역반응을 관찰하였다. C57BL/6 생쥐에 호르텐스극구흡충 피낭유충을 마리 당 15개 경구감염 시킨 후 2주 경과하여 충체를 회수하였고 소장 점막의 배상세포와 비만세포의 변화를 관찰하였으며 protein chip을 이용하여 혈청 내 cytokine의 변화를 비교 확인하였다. 그 결과 호르텐스극구흡충을 감염시킨 군에서는 평균 8.3마리, 알칼리환원 수를 급이한 군에서는 평균 10마리의 충체를 회수하였다. 배상 세포 변화의 관찰에서는 호르텐스극구흡충을 감염시키고 전해알칼리환원수를 급이한 실험군이 융모 당 평균 4.3개 관찰되어 배상세포의 발현이 적은 것으로(p<0.001) 나타났다. 비만세포 변화의 관찰에서도 호르텐스극구흡충을 감염시키고 전해알칼리환원수를 급이한 실험군에서 응모 당 평균 11개 관찰되었고 정수물을 급이한 호르텐스 감염 대조군에 비해 적게 나타났다(p<0.001). 마우스 혈청 내에서의 cytokine 발현에서 호르텐스극구흡충에 감염된 실험군과 대조군의 비교에서 Th1 cytokine인 IL-6, IL-$1{\beta}$, IFN-${\gamma}$, TNF-${\alpha}$, Il-2 등과 Th2 cytokine인 IL-4, IL-5, IL-10, IL-13 등의 발현은 모두 유의한 차이가 관찰되지 않았다. 본 연구에서 전기분해 알칼리환원수가 호르텐스극구흡충의 감염에 있어 C57BL/6 마우스에서 장점막조직의 배상세포 수 및 mucin terminal sugar의 변화를 억제하고 아울러 이로 인해 충체배출이 지연되며, 알칼리환원수가 호르텐스극구흡충에 감염된 C57BL/6 마우스에서 혈청 내 cytokine의 변화에는 큰 영향을 미치지 않는다는 결론을 얻었다.