Bovine spongiform encephalopathy （BSE） is thought to be caused by prions initially derived from sheep scrapie, and epidemiological studies suggest that new viriant form of CJD manifest in Great Britain may be caused...Bovine spongiform encephalopathy （BSE） is thought to be caused by prions initially derived from sheep scrapie, and epidemiological studies suggest that new viriant form of CJD manifest in Great Britain may be caused by BSE prions. PrP^Sc is thought to pathogenic factor of transmissible spongiform encephalopathy （TSE）, which invariably involve a post-translational modification process of PrPc encoded by the host euchromosome PrP gene during the period it converted into the pathogenic form （PrP^Sc）, PrP is nomal cellular protein which has been found in both neuronal and nonneuronal tissues. Since the crucial infectious event in protein-transmitted diseases is an induced misfolding of prion proteins （PrP^c） catalyzed by already misfolded PrP^Sc, it is of high importance that such collisions are enhanced by two-dimensional diffusion in cell membranes is of high importance compared to three-dimensional diffusion in solution. The level of PrP mRNA in brain is higher than other tissue, but purification of PrPc from rodent has been difficult. To understand the formation of PrP^Sc, it seemed useful to develop a system for produced a large quantities of PrPc since there is no nature source of PrP^c. The pCI-neo mammalian expression vector contains the neomycin phosphtransferase gene which serves as a marker for the selection of stable transfected cells with G418. COS-7 cells constitutively express simian viruse 40 （SV40） T-antigen and support replication of expression plasmids containing the SV40 origin of replication, amplifying the introduced expression cassettes, now become important routine of expression a large number of heterologous gene products. In this paper, the authors used pCI-neo vector to construct a recombnant pCIp264 （cotains mPrP, N-signalpeptide and C-GPI anchor） plasmid to express it in the COS-7 cells and meanwhile detect the expression fusion using IN-ELISA, IN-IFA and western blot, and obtain some approximative nature PrPc.展开更多
Background. Human herpesvirus-6 (HHV-6) infection is ubiquitous in selected population with sero-prevalence of 60-80%. Little is known for that in China, except few sporadic studies. To understand prevalence of HHV-6 ...Background. Human herpesvirus-6 (HHV-6) infection is ubiquitous in selected population with sero-prevalence of 60-80%. Little is known for that in China, except few sporadic studies. To understand prevalence of HHV-6 antibody in Chinese population,this seroepidemiological study was conducted.Methods. Sera were collected from 430 healthy persons and donors living in North China,and tested for HHV-6 antibodies using IFA with HHV-6 GS strain passaged on HSB-2 cells as antigen, and titer e-qual or higher than 1:10 was regarded as seropositive.Results. Of the 430 serum samples tested,297 (69.1%) were positive for HHV-6 IgG. Both seropositive rate and GMT in females were significantly higher than those in males,with X2 = 7. 05,P<0. 01 and F = 7.23,P<0. 01,respectively. Statistically significant difference in prevalence of HHV-6 antibody among various age groups was observed in both sexes,with X2=20. 08 and 20. 28,P = 0. 04,respectively,and young children had a higher titer than adults. But, no significant difference in prevalence was observed in blood donors between various age groups or both sexes.Conclusions. This study suggests that HHV-6 infection with seropositive IgG is ubiquitous in North China,and its importance should be further studied.展开更多
基金Acknowledgment This work was supported by grants from the National Natural Science Foundation （30671563, 30700597） and Key Project of Science and Technology of Gansu Province （0801NKDA034） and by gifts from the Development Planning Project of Science and Technology of Lanzhou （07-2-12, 2008- l- 167）.
文摘Bovine spongiform encephalopathy （BSE） is thought to be caused by prions initially derived from sheep scrapie, and epidemiological studies suggest that new viriant form of CJD manifest in Great Britain may be caused by BSE prions. PrP^Sc is thought to pathogenic factor of transmissible spongiform encephalopathy （TSE）, which invariably involve a post-translational modification process of PrPc encoded by the host euchromosome PrP gene during the period it converted into the pathogenic form （PrP^Sc）, PrP is nomal cellular protein which has been found in both neuronal and nonneuronal tissues. Since the crucial infectious event in protein-transmitted diseases is an induced misfolding of prion proteins （PrP^c） catalyzed by already misfolded PrP^Sc, it is of high importance that such collisions are enhanced by two-dimensional diffusion in cell membranes is of high importance compared to three-dimensional diffusion in solution. The level of PrP mRNA in brain is higher than other tissue, but purification of PrPc from rodent has been difficult. To understand the formation of PrP^Sc, it seemed useful to develop a system for produced a large quantities of PrPc since there is no nature source of PrP^c. The pCI-neo mammalian expression vector contains the neomycin phosphtransferase gene which serves as a marker for the selection of stable transfected cells with G418. COS-7 cells constitutively express simian viruse 40 （SV40） T-antigen and support replication of expression plasmids containing the SV40 origin of replication, amplifying the introduced expression cassettes, now become important routine of expression a large number of heterologous gene products. In this paper, the authors used pCI-neo vector to construct a recombnant pCIp264 （cotains mPrP, N-signalpeptide and C-GPI anchor） plasmid to express it in the COS-7 cells and meanwhile detect the expression fusion using IN-ELISA, IN-IFA and western blot, and obtain some approximative nature PrPc.
文摘Background. Human herpesvirus-6 (HHV-6) infection is ubiquitous in selected population with sero-prevalence of 60-80%. Little is known for that in China, except few sporadic studies. To understand prevalence of HHV-6 antibody in Chinese population,this seroepidemiological study was conducted.Methods. Sera were collected from 430 healthy persons and donors living in North China,and tested for HHV-6 antibodies using IFA with HHV-6 GS strain passaged on HSB-2 cells as antigen, and titer e-qual or higher than 1:10 was regarded as seropositive.Results. Of the 430 serum samples tested,297 (69.1%) were positive for HHV-6 IgG. Both seropositive rate and GMT in females were significantly higher than those in males,with X2 = 7. 05,P<0. 01 and F = 7.23,P<0. 01,respectively. Statistically significant difference in prevalence of HHV-6 antibody among various age groups was observed in both sexes,with X2=20. 08 and 20. 28,P = 0. 04,respectively,and young children had a higher titer than adults. But, no significant difference in prevalence was observed in blood donors between various age groups or both sexes.Conclusions. This study suggests that HHV-6 infection with seropositive IgG is ubiquitous in North China,and its importance should be further studied.
