Prepulse inhibition （PPI） of the startle response is a psychophysiological measure of sensorimotor gating believed to be cross-modal between different sensory systems. We analyzed the tactile startle response （TSR...Prepulse inhibition （PPI） of the startle response is a psychophysiological measure of sensorimotor gating believed to be cross-modal between different sensory systems. We analyzed the tactile startle response （TSR） and PPI of TSR （tPPI）, using light as a prepulse stimulus, in the mouse strains A/J and C57BL/6J and 36 recombinant congenic strains derived from them. Parental strains were significantly different for TSR, but were comparable for tPPI. Among the congenic strains, variation for TSR was significant in both genetic backgrounds, but that of tPPI was significant only for the C57BL/6J background. Provisional mapping for loci modulating TSR and tPPI was carried out. Using mapping data from our previous study on acoustic startle responses （ASR） and PPI of ASR （aPPI）, no common markers for aPPI and tPPI were identified. However, some markers were significantly associated with both ASR and TSR, at least in one genetic background. These results indicate cross-modal genetic regulation for the startle response but not for PPI, in these mouse strains.展开更多
This study was conducted to explore the multiplication pattern of the recombinant strain Re-7 of avian influenza virus subtype H5 in Madin Darby Canine Kidney （MDCK） cells and to determine the optimal multiplicity o...This study was conducted to explore the multiplication pattern of the recombinant strain Re-7 of avian influenza virus subtype H5 in Madin Darby Canine Kidney （MDCK） cells and to determine the optimal multiplicity of infection （MOI） and the optimal time for virus harvest. The recombinant strain Re-7 was inoculated at different MOIs into MDCK cells grown in serum-free medium in 100 L bioreactors for replication. Then, the hemagglutination（HA） titer, 50% tissue culture infectious dose （TCID50） and 50% embryo infectious dose （EID50） of culture medium were measured once every 12 h from 24 h after virus inoculation to determine the optimal MOI. After that, virus was inoculated at the optimal MOI determined above into MDCK cells for large-scale virus replication to determine the optimal time for virus harvest. The results showed that the optimal MOI was 10 2, and the optimal time for virus harvest was 60 h after inoculation. Under these conditions, the HA titer, TCIDso per 1 mL and EIDso per 0.1 mL were increased to 1：102 4, 10^7.33 and 10^6.83, respectively. This study provides relatively stable parameters for large-scale production of the recombinant strain Re-7 of avian influenza virus subtype H5.展开更多
This study aimed to reconstruct the origin and worldwide epidemic history of human immunodeficiency virus(HIV)1 subtype C and comprehend how HIV-1 subtype C was introduced into and spread throughout China in the formo...This study aimed to reconstruct the origin and worldwide epidemic history of human immunodeficiency virus(HIV)1 subtype C and comprehend how HIV-1 subtype C was introduced into and spread throughout China in the formof B/C recombinant strains.Envelope sequences ofHIV-1 subtype C and some other subtypes deposited before December 31,2020 were downloaded from the Los Alamos HIV Database and the Chinese National Center for AIDS/STD Control and Prevention Database.The available sequences were screened for quality,and Bayesian analysis was used to build the maximum clade credibility evolutionary tree to analyze and judge the origin and spread of HIV-1 subtype C.HIV-1 subtype C originated in central Africa around 1952,then spread to southern Africa around 1969 and to eastern Africa around 1973.HIV-1 subtype C fromsouthern Africa was introduced into India in 1977.HIV-1 subtype C of eastern Africa was introduced into Brazil in 1987.Indian HIV-1 subtype C was exported to China in three migration events during the period from 1986 to 1989.The two predominant recombinants in China(CRF07_BC and CRF08_BC)emerged in 1988 and 1990,respectively.Other B/C recombinants,namely,CRF64_BC,CRF61_BC and CRF62_BC,originated in 1993,2002 and 2000,respectively.Our study has reconstructed the global origin and evolutionary history of HIV-1 subtype C.In addition,our study demonstrated that the Chinese HIV-1 subtype C originated from three related Indian lineages around the mid to late 1980s and,since then,has formed some B/C recombinants with subtype B that caused a widespread epidemic in China.展开更多
文摘Prepulse inhibition （PPI） of the startle response is a psychophysiological measure of sensorimotor gating believed to be cross-modal between different sensory systems. We analyzed the tactile startle response （TSR） and PPI of TSR （tPPI）, using light as a prepulse stimulus, in the mouse strains A/J and C57BL/6J and 36 recombinant congenic strains derived from them. Parental strains were significantly different for TSR, but were comparable for tPPI. Among the congenic strains, variation for TSR was significant in both genetic backgrounds, but that of tPPI was significant only for the C57BL/6J background. Provisional mapping for loci modulating TSR and tPPI was carried out. Using mapping data from our previous study on acoustic startle responses （ASR） and PPI of ASR （aPPI）, no common markers for aPPI and tPPI were identified. However, some markers were significantly associated with both ASR and TSR, at least in one genetic background. These results indicate cross-modal genetic regulation for the startle response but not for PPI, in these mouse strains.
文摘This study was conducted to explore the multiplication pattern of the recombinant strain Re-7 of avian influenza virus subtype H5 in Madin Darby Canine Kidney （MDCK） cells and to determine the optimal multiplicity of infection （MOI） and the optimal time for virus harvest. The recombinant strain Re-7 was inoculated at different MOIs into MDCK cells grown in serum-free medium in 100 L bioreactors for replication. Then, the hemagglutination（HA） titer, 50% tissue culture infectious dose （TCID50） and 50% embryo infectious dose （EID50） of culture medium were measured once every 12 h from 24 h after virus inoculation to determine the optimal MOI. After that, virus was inoculated at the optimal MOI determined above into MDCK cells for large-scale virus replication to determine the optimal time for virus harvest. The results showed that the optimal MOI was 10 2, and the optimal time for virus harvest was 60 h after inoculation. Under these conditions, the HA titer, TCIDso per 1 mL and EIDso per 0.1 mL were increased to 1：102 4, 10^7.33 and 10^6.83, respectively. This study provides relatively stable parameters for large-scale production of the recombinant strain Re-7 of avian influenza virus subtype H5.
基金supported by Science Priority Grant(2019SKLID602)the State Key Laboratory of Infectious Disease Prevention and Control,and the National Natural Science Foundation of China(grant number:81861138011).
文摘This study aimed to reconstruct the origin and worldwide epidemic history of human immunodeficiency virus(HIV)1 subtype C and comprehend how HIV-1 subtype C was introduced into and spread throughout China in the formof B/C recombinant strains.Envelope sequences ofHIV-1 subtype C and some other subtypes deposited before December 31,2020 were downloaded from the Los Alamos HIV Database and the Chinese National Center for AIDS/STD Control and Prevention Database.The available sequences were screened for quality,and Bayesian analysis was used to build the maximum clade credibility evolutionary tree to analyze and judge the origin and spread of HIV-1 subtype C.HIV-1 subtype C originated in central Africa around 1952,then spread to southern Africa around 1969 and to eastern Africa around 1973.HIV-1 subtype C fromsouthern Africa was introduced into India in 1977.HIV-1 subtype C of eastern Africa was introduced into Brazil in 1987.Indian HIV-1 subtype C was exported to China in three migration events during the period from 1986 to 1989.The two predominant recombinants in China(CRF07_BC and CRF08_BC)emerged in 1988 and 1990,respectively.Other B/C recombinants,namely,CRF64_BC,CRF61_BC and CRF62_BC,originated in 1993,2002 and 2000,respectively.Our study has reconstructed the global origin and evolutionary history of HIV-1 subtype C.In addition,our study demonstrated that the Chinese HIV-1 subtype C originated from three related Indian lineages around the mid to late 1980s and,since then,has formed some B/C recombinants with subtype B that caused a widespread epidemic in China.
