• Parasites, Hosts and Diseases
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• 제42권1호
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• pp.19-26
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• 2004

We investigated the induction of resistance to Clonorchis sinensis infection by prior infection in rat and hamster models. Animals were challenged with C. sinensis metacercariae, then treated with praziquantel and reinfected. Worm recovery rate in reinfected animals was used to estimate resistance to reinfection. The determined resistance rates to reinfection in rats and hamsters were 97.7% and 10.3%, respectively. In rats, cure from the primary infection of C. sinensis increased resistant to reinfection, and the greatert the worm burden and the longer the duration of primary infection, the higher was the resistance rate. For primary infection doses of 10, 40 and 100 metacercariae per rat, the resistance rates were 87.4%, 93.8% and 98.4%, respectively. The resistance rates in rats after 2 or 8-week primary infection were 78.7% and 95.3%, respectively. All worms recovered from reinfected rats were immature. When cured rats were administered with methylprednisolone, resistance to reinfection became impaired. These findings indicate that rats develop a high degree of resistance to reinfection by C. sinensis after cure. The growths and maturations of reinfected worms were also impaired.

• 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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• 제48권2호
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• pp.133-138
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• 2010

Infection status of intestinal flukes was investigated in residents of Muan-gun, Jeollanam-do, the Republic of Korea. Total 1,257 fecal samples of residents were examined by formalin-ether sedimentation technique and Kato-Katz thick smear method. Helminth eggs were detected from 95 (7.6%) residents, and eggs of heterophyid flukes and Clonorchis sinensis were found from 62 (4.9%) and 40 (3.2%) cases, respectively. The larger heterophyid eggs, somewhat darkbrown in color and $37.7{\times}21.5{\mu}m$ in average size, and found in 32 (2.6%) out of 62 egg positive cases of heterophyid flukes. To confirm the adult flukes, we performed worm recovery from 12 cases after praziquantel treatment and purgation with $MgSO_4$. A total of 1,281 adult flukes, assigned to 7 species, were recovered from 9 cooperative cases. Heterophyes nocens (total 981 specimens) was collected from 9 cases, Stictodora fuscata (80) from 7, Gymnophalloides seoi (75) from 5, Pygidiopsis summa (140) from 3, Stellantchasmus falcatus (3) from 2, and Stictodora lari and Acanthotrema felis (each 1 worm) from 1 case each. The intrauterine eggs of S. fuscata collected from the recovered worm were identical with the larger heterophyid eggs detected in the stool examination. By the present study, it was confirmed that A. felis is a new intestinal fluke infecting humans, and residents in Muan-gun, Jeollanam-do are infected with variable species of intestinal trematodes.

• Parasites, Hosts and Diseases
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• 제21권2호
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• pp.224-233
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• 1983

몇가지 실험동물의 Firbricola seoulensis 실험감염에 대한 감수성을 알아보고 숙주로서의 적합도를 관찰하고자 중간숙주로 알려진 뱀으로부터 피예유충을 분리하여 50∼2,000개군으로 나누고 횐쥐, 마우스, 개, 고양이, 토끼 및 닭등 총 127마리에 각각 실험감염시킨 다음 3일부터 8주까지 각 숙주내에서의 충체회수률 및 충체성숙도를 관찰하고 비교분석 하였다. 그 결과는 다음과 같다. 1. 총 충체회수률은 횐쥐에서 가장 높아 40.0%이었으며, 그 다음이 마우스로 33.9%이었고, 고양이 20.9%, 개 11.4%, 토끼 0.05% 및 닭 O%의 순으로 나타났다. 충체회수율은 감염기계이 길어짐에 따라 차차 저하되는 경향을 보였으며 감염피낭유충수에 따라서도 다양하게 변화하는 것으로 나타났다. 2. 횐쥐에는 피예유충 1,000개를, 마우스에는 200개를 감염시켰을때 충체회수률이 가장 높았으며 이 정도의 파낭유충수가 이들 동물을 감염시키는데 적당한 감염량으로 생각되었다. 3. 각 실험동물에서 주 기생부위는 소장이었고 고 중에서도 특히 십이지장이었다. 4. 각 동물에서 회수한 충체의 성숙도(성숙충체수/관찰충체수)는 횐쥐와 마우스에서 모두 100%이었고 개에서는 22.7%이었으며 고양이에서는 0%로 전혀 성숙된 충체가 없었다. 이상의 결과를 종합해볼 때 6종의 실험동물중 충체회수율 및 총체성숙도가 높은 횐쥐와 마우스가 Fibricola seoulensis의 가장 좋은 호적숙주로 생각되었다.

• Parasites, Hosts and Diseases
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• 제29권2호
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• pp.161-172
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• 1991

실험실 내에서 호르텐스극구흡충(Echinostoma hortense)의 생활사를 유지하면서 여러 가지 생물학적 현상을 관찰하였다. 충란은 $29~30^{\circ}C$ 항온기에서 배양 약 13일에 miracidium으로 발육하였고, miracidium은 평균 $93.8{\times}53.6{\;}{\mu\textrm{m}}$의 크기였으며 체표에 $7~11{\;}{\mu\textrm{m}}$ 길이의 섬모가 덮혀 있었다. Miracidium을 패류 Lymnaea pervia에 접촉 감염시켰던 바, 접촉 후 14일에 평균 $1.19{\times}0.27{\;}mm$ 크기의 제 1기 redid로, 30일에는 평균 $1.40{\times}0.26{\;}mm$ 크기의 성숙한 제 2기 redid로 발육하였다. Cercaria는 평균 $295.5{times}145.0{\;}{\mu\textrm{m}}$의 크기였으며, 두관의 발육이 미약하였고 두극이 관찰되지 않았다. 올챙이에 이 cercaria를 접촉시킨 결과, 모든 올챙이가 감염되었으며 피낭유충 회수율도 평균 88.5%로 높았다. 올챙이로부터 회수한 피낭유충은 타원형이었으며 평균 $167.7{\times}129.9{\;}{\mu\textrm{m}}$의 크기였다. Cercaria감염 후 올챙이 체내에 약 12시간 동안 머문 피낭유충은 마우스에 대한 감염력이 5.0%였으나 점차 증가하여 9일간 머문 것은 90.0%로 최대치를 보였고 이후 감소하여 50일 머문 것은 55.0%의 감염력을 보였다. 피낭유충이 마우스 체내에서 성충이 되기까지는 약 11~12일이 소요되었다. 이상과 같이 실험실 내에서 E. hortense의 전 생활사를 완료시키는 데에 최소한 55~58 일이 소요되었다.

• Parasites, Hosts and Diseases
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• 제51권6호
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• pp.767-769
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• 2013

Opisthorchiasis, a risk factor for cholangiocarcinoma in humans, is of public health importance in Thailand. The Annual Surveillance Reports from Nan and Lampang Provinces, Thailand, for the year 2011 showed an opisthorchiasis prevalence of over 70% by recovery of eggs in the feces. This study investigated whether most cases are actually due to minute intestinal flukes (MIF) rather than Opisthorchis viverrini, as the eggs of both can hardly be differentiated by morphology. Fifty and 100 cases from residents in Nan and Lampang, respectively, had stools positive for eggs initially assumed to be those of O. viverrini. Each patient was given praziquantel at 40 mg/kg in a single dose. After 2 hr, 30-45 ml of the purgative magnesium sulfate was given, and stools were collected up to 4 times sequentially. The stools were examined for adult worms by simple sedimentation. It was found that 39 of 50 cases (78.0%) from Nan Province had Haplorchis taichui, with intensities ranging from 5 to 1,250 with an average of 62 worms/case. Taenia saginata (7 cases) and Enterobius vermicularis (1 case) were other helminths recovered as the co-infectants. In Lampang Province, H. taichui was recovered from 69 cases (69.0%). The number of flukes recovered ranged from 1 to 4,277, with an average of 326 worms/case. Four cases had Phaneropsolus bonnei, and 10 T. saginata as the co-infectants. Adult specimens of O. viverrini were not recovered from any stool. Clearly, MIF infection, especially haplorchiasis, is more common in northern Thailand. These findings should encourage the Public Health Office to employ more specific tools than Kato's method for surveillance of opisthorchiasis in Thailand.

• Parasites, Hosts and Diseases
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• 제26권1호
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• pp.9-14
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• 1988

근교계 골든 햄스터 (Mesecricetus auratus)의 실험적 간흡충감염에 대한 감수성을 구명하기 위하여 햄스티 25마리를 5마리씩 5군으로 나누어 각각 5, 10, 20, 30 및 50개의 간흡충 피낭유충을 경구투여하였다. 투여후 제45일에 햄스터를 고살하여 간흡충 성충을 회수하였다. 햄스터 25마리에서 간흡충의 충체회수율은 48.4∼92.0%로 평균 57.9%이었다. 피낭유충 5개씩을 투여한 제1군에서는 성충이 평균 4.6마리 회수되어 충체회수율 92.0%로 가장 높았고, 피낭유충 50개를 투여한 제5군에서는 평균 24.2마리의 성충이 회수되어 회수율 48.4%로서 가장 낮았다. 피낭유충 10, 20 및 30개씩을 투여한 제2, 3 및 4군에서는 각각 그 충체회수율이 70.0%, 65.0% 및 57.3%로서 투여한 피낭유충의 수가 많을수록 충체회수율은 감소되는 경향을 나타내었다. 햄스터에서의 간흡충의 충란배출시작 전기간은 15∼17일로 평균 16일이었다. 회수한 충체의 체장, 체폭, 구흡반 및 복흡반의 크기는 각군간에 유의적 차가 없었다. Eggs·Per-gram(EPG)은 감염후 제45일까지 증가되었고 eggs-per-gram-per-fluke(EPGPF)와 eggs-per-day-per-fluke(EPDPF)는 충체부하가 많을수록 감소하였다. 이상의 성적으로 미루어 보아 깁스터는 간흡충의 호적숙주임을 알았다.

• International Journal of Industrial Entomology and Biomaterials
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• 제16권1호
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• pp.21-27
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• 2008

The expression of heat shock protein genes (Hsp 70, Hsp 40, Hsp 20.8 and Hsp 20.4) against thermal stress in silkworm Bombyx mori was performed through semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Upon exposure of silkworm to two temperature regimes ($38^{\circ}C$ and $42^{\circ}C$), significant change in the expression of Hsp gene was observed as compared to the control. Hsp 70 and Hsp 40 showed increased expression than the small heat shock protein genes Hsp 20.8 and Hsp 20.4. The Hsp 70 showed increased expression during the recovery period as compared to 1 hr thermal treatments ($38^{\circ}C$/1 hr and $42^{\circ}C$/1 hr). Whereas, Hsp 40, Hsp 20.8 and Hsp 20.4 genes showed higher expression level at initial stages that later gradually decrease during recovery period. Tissue specific expression of Hsp 70 showed variation in the level of expression amongst the tissues. The mid gut and fat body tissues showed higher expression than the cuticle and silk gland tissue. The Hsp 70, Hsp 40 gene expression was analyzed in thermotolerant (Nistari) and thermo susceptible silk worm strain (NB4D2) and results showed significant variation in their expression level. The Nistari showed higher expression of Hsp 70 and Hsp 40 genes than the NB4D2. These findings provide a better understanding of cellular protection mechanisms against environmental stress such as heat shock, as these Hsps are involved in an organism thermotolerance.

• Parasites, Hosts and Diseases
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• 제31권2호
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• pp.135-140
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• 1993

실험적으로 스파르가눔을 프라지콴텔 처치, 감마선 조사 및 기계적 절단을 시행하고 마우스에 경구감염시켜 감염력을 관찰하였다. 스파르가눔은 유혈목이(Rhabdophis tigrina)로 부터 분리 수집한 것 또는 실험감염 마우스로 부터 회수한 것이었으며 마우스는 서울대학교 동물실험실로 부터 공급받은 ICR계이었다. 스파르가눔은 $10{\;}\mu\textrm{g}/ml$ 농도의 프라지콴텔용액(대조군: Tyrode용액에서 4시간 배양)에 넣어 $36^{\circ}C$ 배양기에서 30분, 1, 2 및 4시간 동안 배양한 다음 각 실험군당 4들마리의 마우스에 각각 5마리씩 경구감염시키고 1개월 후에 충체를 회수하였던 바, 각각 평균 80%(대조군), 100%, 80%, 80% 및 76%의 회수율을 나타내었다. 스파르가눔을 $Cs^{l37}$ 감마선으로 10, 30, 50, 75, 100, 150 및 1000 Gy로 조사한 다음 각 군당 2틱마리의 마우스에 각각 5마리씩 경구감염시키고 1개월 후에 충체를 회수하였던 바, 각각 평균 96%(대조군), 100%, 76%, 93%, 77%, 69%, 56% 및 5%의 회수율을 나타내었다. 두절의 전단으로 부터 각각 0.5, 1, 2 및 3 mm 부위를 잘라서 각 군당 4-5마리의 마우스에 각각 5마리씩 경구감염시키고 1개월 후에 충체를 회수하였던 바, 80%, 90%, 70%, 88% 및 90%(대조군)의 회수율을 나타내었다. 이상의 결과로 스파르가눔이 프라지콴텔, 감마선 및 기계적 절단에 대하여 매우 저항성이 높으며 마우스에서의 감염력 및 재생력을 나타내는 부위가 스파르가눔의 두절 앞 끝에 위치함을 알 수 있었다.

• Parasites, Hosts and Diseases
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• 제46권4호
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• pp.279-283
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• 2008

To examine humoral immune responses in the host, we measured serum antibody levels in different strains of mice (ICR, BALB/c, and C3H) experimentally infected with Neodiplostomum seoulense. Specific IgG antibody levels were increased remarkably with little difference among 3 strains of mice infected with N. seoulense from day 7 to 35 post-infection. More target proteins of adult parasites reacted with IgG at the time when the worm recovery decreased compared with other times. More than 20 protein bands, from 14 kDa to 94 kDa in size, were separated from the crude antigen of N. seoulense adults by SDS-PAGE, and among them 26, 30, 35, 43, 54, 67, and 94 kDa proteins were the major antigenic proteins. The results suggest that significant IgG antibody responses occur against N. seoulense in mice and this may be related with expulsion of worms.