• Title/Summary/Keyword: Rodent

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Mucosal immunity against parasitic gastrointestinal nematodes

  • Onah, Denis-Nnabuike;Nawa, Yukifumi
    • Parasites, Hosts and Diseases
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    • v.38 no.4
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    • pp.209-236
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    • 2000
  • The last two decades witnessed significant advances in the efforts of immune-parasitologists to elucidate the nature and role of the host mucosal defence mechanisms against intestinal nematode parasites. Aided by recent advances in basic immunology and biotechnology with the concomitant development of well defined laboratory models of infection, immunoparasitologists have more precisely analyzed and defined the different immune effector mechanisms during the infection; resulting in great improvement in our current knowledge and understanding of protective immunity against gastrointestinal (GI) nematode parasites. Much of this current understanding comes from experimental studies in laboratory rodents, which have been used as models of livestock and human GI nematode infections. These rodent studies, which have concentrated on Heligmosomoides polygyrus, Nippostrongylus brasiliensis, Strongyloides ratti/5. venezuelensis. Trichinella spiralis and trichuris muris infections in mice and rats, have helped in defining the types of T cell responses that regulate effector mechanisms and the effector mechanisms responsible for worm expulsion. In addition, these studies bear indications that traditionally accepted mechanisms of resistance such as eosinophilia and IgE responses may not play as important roles in protection as were previously conceived. In this review, we shall, from these rodent studies, attempt an overview of the mucosal and other effector responses against intestinal nematode parasites beginning with the indices of immune protection as a model of the protective immune responses that may occur in animals and man.

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Estimation of Human Carcinogenic Potency (HCP) of Carcinogens in Risk Assessment and Management. (위해성 평가 및 관리에 있어서 발암물질의 인체발암능력 평가)

  • 이병무;김대영;김세기;김근종
    • Environmental Mutagens and Carcinogens
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    • v.19 no.1
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    • pp.39-45
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    • 1999
  • Human Carcinogenic Potency (HCP) can be estimated based on human daily exposure dose to carcinogen (Dh), body weight (Wh), 10% tumorigenic dose (TD10), and slope factor at TD10 (Q10) from 2-yr bioassay data. This approach is more relevant to humans generally exposed to low doses of carcinogens and can reduce more of extrapolation errors from high dose in animal experiments to low dose in humans than HERP (human exposure dose/rodent potency dose) proposed by Ames et al. (Science, 236, 271-280, 1987). TD50 and HERP have been routinely used to compare rodent carcinogenic potency and human carcinogenic potency, but those approaches have had limitations in extrapolation of high dose to low dose in humans. The advantages of HCP are to estimate human exposure dose (Dh) by human monitoring instead of environmental monitoring, to consider slope factor (Q10) which reflects the tendency of curve at low dose, and to use TD10 which represents much lower dose thant TD50 or HERP. HCP will be a useful parameter for the estimation of human carcinogenic potency in risk assessment and management of carcinogens.

Isolation and Characterization of Vaccine Candidate Genes Including CSP and MSP1 in Plasmodium yoelii

  • Kim, Seon-Hee;Bae, Young-An;Seoh, Ju-Young;Yang, Hyun-Jong
    • Parasites, Hosts and Diseases
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    • v.55 no.3
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    • pp.255-267
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    • 2017
  • Malaria is an infectious disease affecting humans, which is transmitted by the bite of Anopheles mosquitoes harboring sporozoites of parasitic protozoans belonging to the genus Plasmodium. Despite past achievements to control the protozoan disease, malaria still remains a significant health threat up to now. In this study, we cloned and characterized the full-unit Plasmodium yoelii genes encoding merozoite surface protein 1 (MSP1), circumsporozoite protein (CSP), and Duffy-binding protein (DBP), each of which can be applied for investigations to obtain potent protective vaccines in the rodent malaria model, due to their specific expression patterns during the parasite life cycle. Recombinant fragments corresponding to the middle and C-terminal regions of PyMSP1 and PyCSP, respectively, displayed strong reactivity against P. yoelii-infected mice sera. Specific native antigens invoking strong humoral immune response during the primary and secondary infections of P. yoelii were also abundantly detected in experimental ICR mice. The low or negligible parasitemia observed in the secondary infected mice was likely to result from the neutralizing action of the protective antibodies. Identification of these antigenic proteins might provide the necessary information and means to characterize additional vaccine candidate antigens, selected solely on their ability to produce the protective antibodies.

Establishment of Transgenic Mouse with the E6 and E7 Genes of Human Papillomavirus Type 16 (인간 Papillomavirus의 E6, E7 유전자를 이용한 Transgenic Mouse의 확립)

  • Hwang, Yong-Il;Lee, Seung-Cheol;Kim, Hyun-Su
    • The Journal of Korean Society of Virology
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    • v.26 no.1
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    • pp.115-120
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    • 1996
  • Human papillomavirus (HPV), especially type 16 and 18, has been closely associated with carcinomas and uterine cevical cancer, recently. From in vitro assays, E6 and E7 genes of HPV16 are closely linked with transformation of cell lines of rodent fibroplasts. However, the transforming activity of E6 and E7 genes of HPV type 16 in vivo has not been fully elucidated. For explaining this mechanism, we prepared a expression system with the promoter of mouse mammary tumorvirus long terminal repeat and E6E7's open reading frames. This expression system was introduced in rodent cell lines, No. 7, 3Y1 and shown normal transforming abilities. And, we produced transgenic mice with E6, E7 expression system. These transgenic mice were confirmed from Southern blot analysis. One male of them was observed enlargement of the testis after 5 months postdelivery.

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Rodent Experiments for Pedestrian Flow Simulation at Exit with Various Angles (다양한 각도의 출구에서의 보행자 유동 시뮬레이션을 위한 설치류 실험)

  • Oh, Hyejin;Lyu, Jaehee;Park, Junyoung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.4
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    • pp.30-39
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    • 2016
  • There have been many cases of deaths from crushing caused by dense crowds. Numerous studies about pedestrian flow have performed various simulations, but the experimental data to prove the simulations are still not enough. In this paper, the evacuation of pedestrians for proving pedestrian flow simulation is observed. Due to the possibility of real casualties, it is difficult to experiment with humans directly. Therefore, ten C57BL/6NCrSIc mice have been used. It is assumed that C57BL/6NCrSIc mice act like humans in panic situations. Electrical Stimulus Experiments on mice are conducted for exits with various angles. ICY software is applied in this paper. As a result, the mice escape fast at a proper angle of 45 to 60 degrees.