http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Yoon, Sejoung,Park, Woo-Yoon,Yu, Jae-Ran Elsevier 2012 Experimental parasitology Vol.131 No.3
<P><B>Graphical abstract</B></P><P><ce:figure id='f0030'></ce:figure></P><P><B>Highlights</B></P><P>► Recombinant thioredoxin peroxidase of <I>Cryptosporidium parvum</I> and <I>Cryptosporidium muris</I> were expressed. ► Hydrogen peroxide consumption was greater in rCpTPx than in rCmTPx. ► Peroxidase activity of rCpTPx was highly enhanced by GSH, but that of rCmTPx was not. ► rCpTPx protected plasmid DNA from damage with only 12% of dose required with rCmTPx.</P> <P><B>Abstract</B></P><P><I>Cryptosporidium parvum</I> can survive exposure to harsh environmental conditions, various disinfectants, and high doses of γ-irradiation. In an animal study, more than 25kGy of γ-irradiation was necessary to eliminate <I>C. parvum</I> infectivity from mice. In contrast, <I>Cryptosporidium muris</I> (murine <I>Cryptosporidium</I>), which lives in stomach epithelium, lost its infectivity in mice with 1kGy of γ-irradiation. Recently, it was found that thioredoxin peroxidase was highly expressed in <I>C. parvum</I> oocysts irradiated with high doses of γ-irradiation. Therefore we hypothesize that antioxidant activity of the thioredoxin peroxidase is involved in the radioresistance of <I>C. parvum</I>. To verify this, thioredoxin peroxidases of <I>C. parvum</I> (CpTPx) and <I>C. muris</I> (CmTPx) were expressed in <I>Escherichia coli</I> cells, and their antioxidant activities were compared. Both CpTPx and CmTPx belong to the 2-Cys family of peroxiredoxins. Hydrogen peroxide consumption was approximately 2- to 12-fold greater in recombinant CpTPx (rCpTPx) than in recombinant CmTPx (rCmTPx) in the presence of 0.2mM dithioerythritol or glutathione (GSH), respectively. The peroxidase activity of rCpTPx was highly enhanced by GSH, but that of rCmTPx was not. The minimum dose of rCpTPx required to protect supercoiled plasmid DNA from damage by metal-catalyzed oxidation was only 12% of that required with rCmTPx. The results showed that rCpTPx has more powerful antioxidant activity than rCmTPx. Further investigations on the role of CpTPx in the radioresistance of <I>C. parvum</I> are warranted.</P>
Sejoung Yoon,Jae-Ran Yu 대한기생충학열대의학회 2011 The Korean Journal of Parasitology Vol.49 No.4
In the genus Cryptosporidium, there are more than 14 species with different sizes and habitats, as well as different hosts. Among these, C. parvum and C. hominis are known to be human pathogens. As C. parvum can survive exposure to harsh environmental conditions, including various disinfectants or high doses of radiation, it is considered to be an important environmental pathogen that may be a threat to human health. However, the resistance of other Cryptosporidium species to various environmental conditions is unknown. In this study, resistance against γ-irradiation was compared between C. parvum and C. muris using in vivo infection in mice. The capability of C. muris to infect mice could be eliminated with 1,000 Gy of γ-irradiation, while C. parvum remained infective in mice after up to 1,000 Gy of γ-irradiation, although the peak number of oocysts per gram of feces decreased to 16% that of non-irradiated oocysts. The difference in radioresistance between these 2 Cryptosporidium species should be investigated by further studies.
Characterization of the thioredoxin peroxidase from <i>Cryptosporidium parvum</i>
Joung, Migyo,Yoon, Sejoung,Choi, Kyungmi,Kim, Joung-Yeon,Park, Woo-Yoon,Yu, Jae-Ran Elsevier 2011 Experimental parasitology Vol.129 No.4
<P><B>Graphical abstract</B></P><P><ce:figure id='f0050'></ce:figure></P><P><B>Highlights</B></P><P>► Recombinant thioredoxin peroxidase of <I>Cryptosporidium parvum</I> (CpTPx) was expressed. ► CpTPx is a two-cysteine peroxiredoxin containing cysteines at positions 49 and 170. ► CpTPx exhibited substantial thiol-dependent peroxidase activity. ► CpTPx protected plasmid DNA from damage by metal-catalyzed oxidation <I>in vitro</I>. ► CpTPx was expressed mainly in the cytoplasm of <I>C. parvum</I>.</P> <P><B>Abstract</B></P><P><I>Cryptosporidium parvum</I> can survive exposure to harsh environmental conditions, various disinfectants, and high doses of γ-radiation. Recently, it was found that the expression of thioredoxin peroxidase (CpTPx) in <I>C. parvum</I> increased after a high dose of γ-irradiation to the parasite. CpTPx is a two-cysteine peroxiredoxin that contains cysteines at positions 49 and 170. Recombinant CpTPx fused to an N-terminal hexahistidine sequence, (His)<SUB>6</SUB>-CpTPx, exhibited substantial thiol-dependent peroxidase activity that protected plasmid DNA from damage by metal-catalyzed oxidation <I>in vitro</I>. (His)<SUB>6</SUB>-CpTPx was used to screen sera from <I>C. parvum</I>-infected mice and humans for antibodies against CpTPx. In Western blots, 10% of the mouse sera and 20% of the human sera reacted with (His)<SUB>6</SUB>-CpTPx, suggesting that after infection by <I>C. parvum</I> CpTPx can induce a host-immune reaction but is not a major antigen. Immunolocalization studies revealed that CpTPx is expressed mainly in the cytoplasm of <I>C. parvum</I> at various developmental stages.</P>
Cryptosporidium hominis Infection Diagnosed by Real-Time PCR-RFLP
Hyeng-Il Cheun,Kyungjin Kim,Sejoung Yoon,Won-Ja Lee,Woo-Yoon Park,Seobo Sim,Jae-Ran Yu 대한기생충학열대의학회 2013 The Korean Journal of Parasitology Vol.51 No.3
There are approximately 20 known species of the genus Cryptosporidium, and among these, 8 infect immunocompetent or immunocompromised humans. C. hominis and C. parvum most commonly infect humans. Differentiating between them is important for evaluating potential sources of infection. We report here the development of a simple and accurate real-time PCR-based restriction fragment length polymorphism (RFLP) method to distinguish between C. parvum and C. hominis. Using the CP2 gene as the target, we found that both Cryptosporidium species yielded 224 bp products. In the subsequent RFLP method using TaqI, 2 bands (99 and 125 bp) specific to C. hominis were detected. Using this method, we detected C. hominis infection in 1 of 21 patients with diarrhea, suggesting that this method could facilitate the detection of C. hominis infections.