We have previously reported that the human ACAT1 gene produces a chimeric mRNA through the interchromosomal processing of two discontinuous RNAs transcribed from chromosomes 1 and 7. The chimeric mRNA uses AUG1397-139...We have previously reported that the human ACAT1 gene produces a chimeric mRNA through the interchromosomal processing of two discontinuous RNAs transcribed from chromosomes 1 and 7. The chimeric mRNA uses AUG1397-1399 and GGC1274-1276 as translation initiation codons to produce normal 50-kDa ACAT1 and a novel enzymatically active 56-kDa isoform, respectively, with the latter being authentically present in human cells, including human monocyte- derived macrophages. In this work, we report that RNA secondary structures located in the vicinity of the GGC1274-1276 codon are required for production of the 56-kDa isoform. The effects of the three predicted stem-loops （nt 1255-1268, 1286-1342 and 1355-1384） were tested individually by transfecting expression plasmids into cells that contained the wild-type, deleted or mutant stem-loop sequences linked to a partial ACAT1 AUG open reading frame （ORF） or to the ORFs of other genes. The expression patterns were monitored by western blot analyses. We found that the upstream stem-loop1255-1268 from chromosome 7 and downstream stem-loop1286-1342 from chromosome 1 were needed for production of the 56-kDa isoform, whereas the last stem-loop135s-1384 from chromosome 1 was dispensable. The results of experi- ments using both monocistronic and bicistronic vectors with a stable hairpin showed that translation initiation from the GGC1274-1276 codon was mediated by an internal ribosome entry site （IRES）. Further experiments revealed that translation initiation from the GGC1274-1276 codon requires the upstream AU-constituted RNA secondary structure and the downstream GC-rich structure. This mechanistic work provides further support for the biological significance of the chimeric nature of the human ACAT1 transcript.展开更多
我们提出了登陆病综合征(mal de débarquement syndrome,MdDS)的诊断标准,并将其纳入国际前庭疾病分类。这些诊断标准包括:(1)非旋转性眩晕,其特征是持续性或1天中大部分时间都存在振荡感("摇摆"、"摆动"或&qu...我们提出了登陆病综合征(mal de débarquement syndrome,MdDS)的诊断标准,并将其纳入国际前庭疾病分类。这些诊断标准包括:(1)非旋转性眩晕,其特征是持续性或1天中大部分时间都存在振荡感("摇摆"、"摆动"或"晃动");(2)被动运动结束后48小时内发作;(3)症状在被动运动时(例如驾驶)可暂时减轻;(4)症状持续>48小时。病程不足1月且症状仍持续者,定义为"进展型";如果症状在1个月或1个月内得以缓解,观察期至少延长到缓解点,则为"短暂型";如果症状持续超过1个月不缓解,则为"持续型"。事实上,MdDS患者亦可伴发空间定向障碍、视觉运动不耐受、疲劳以及头痛或焦虑加剧的症状。本文也回顾总结了MdDS与前庭性偏头痛、运动病及持续性姿势-感知性头晕(persistent postural perceptual dizziness,PPPD)的临床鉴别要点。此外,非运动触发、可通过运动缓解的振荡性眩晕在其他前庭疾病、内科疾病、精神紧张加剧或代谢紊乱之后出现,由于其具有MdDS和PPPD这2种疾病的特点,在非运动诱发的表现描述方面多样,因此,进一步研究其现象及生物学与MdDS、PPPD及其他前庭疾病的相关性是非常有必要的。展开更多
Marek’s disease (MD) is a lymphoproliferative disease of domestic chickens caused by Marek’s disease virus (MDV), an oncogenic and highly contagious α-herpesvirus. MD has been controlled by vaccination but sporadic...Marek’s disease (MD) is a lymphoproliferative disease of domestic chickens caused by Marek’s disease virus (MDV), an oncogenic and highly contagious α-herpesvirus. MD has been controlled by vaccination but sporadic outbreaks of MD still occur in some parts of the world. Efforts to improve vaccine efficacy have continued in both research communities and vaccine industries. We reported the host genetic variation affecting Marek’s disease vaccine-induced immunity in chickens earlier. In this study, we evaluated chicken lines, vaccines, and line by vaccine interaction on the protective efficacy of vaccination against MD. Specific pathogen free chickens from the relatively resistant line 63 and the highly susceptible line 72 were primarily used to evaluate the protection by three kinds of vaccines (rMd5ΔMeq, CVI988/Rispens, and HVT) upon challenge with a very virulent plus strain of MDV, vv+648A. Our data confirmed that both the chicken line and the vaccine significantly affected the protective efficacy of vaccination and showed that a chicken line by vaccine interaction, in most of the trials, also altered vaccine protective efficacy. More interestingly, although the protective index of all vaccine strains was higher in resistant than in susceptible line of chickens, the difference for HVT protection was striking and warrants further study. The findings may have important implications for vaccine development as well as for selective use of particular vaccines in specific lines of chickens to achieve maximum protection at minimized costs.展开更多
BACKGROUND The coronavirus disease 2019(COVID-19)pandemic altered education,exams,and residency applications for United States medical students.AIM To determine the specific impact of the pandemic on US medical studen...BACKGROUND The coronavirus disease 2019(COVID-19)pandemic altered education,exams,and residency applications for United States medical students.AIM To determine the specific impact of the pandemic on US medical students and its correlation to their anxiety levels.METHODS An 81-question survey was distributed via email,Facebook and social media groups using REDCapTM.To investigate risk factors associated with elevated anxiety level,we dichotomized the 1-10 anxiety score into low(≤5)and high(≥6).This cut point represents the 25th percentile.There were 90(29%)shown as low anxiety and 219(71%)as high anxiety.For descriptive analyses,we used contingency tables by anxiety categories for categorical measurements with chi square test,or mean±STD for continuous measurements followed by t-test or Wilcoxson rank sum test depending on data normality.Least Absolute Shrinkage and Selection Operator was used to select important predictors for the final multivariate model.Hierarchical Poisson regression model was used to fit the final multivariate model by considering the nested data structure of students clustered within State.RESULTS 397 medical students from 29 states were analyzed.Approximately half of respondents reported feeling depressed since the pandemic onset.62%of participants rated 7 or higher out of 10 when asked about anxiety levels.Stressors correlated with higher anxiety scores included“concern about being unable to complete exams or rotations if contracting COVID-19”(RR 1.34;95%CI:1.05-1.72,P=0.02)and the use of mental health services such as a“psychiatrist”(RR 1.18;95%CI:1.01-1.3,P=0.04).However,those students living in cities that limited restaurant operations to exclusively takeout or delivery as the only measure of implementing social distancing(RR 0.64;95%CI:0.49-0.82,P<0.01)and those who selected“does not apply”for financial assistance available if needed(RR 0.83;95%CI:0.66-0.98,P=0.03)were less likely to have a high anxiety.CONCLUSION COVID-19 significantly impacted medical students in nu展开更多
Background:Zellweger spectrum disorder(ZSD)is an autosomal recessive disease caused by mutations in any one of 13 PEX genes whose protein products are required for peroxisome assembly.Retinopathy leading to blindness ...Background:Zellweger spectrum disorder(ZSD)is an autosomal recessive disease caused by mutations in any one of 13 PEX genes whose protein products are required for peroxisome assembly.Retinopathy leading to blindness is one of the major handicaps faced by affected individuals,but treatment for this is supportive only.To test whether we could improve visual function in ZSD,we performed a proof-of-concept trial for PEX1 gene augmentation therapy using the Pex1-G844D mouse model,which bears the equivalent to a common human mutation.This model exhibits a gradual decline in scotopic ffERG response,an always residual photopic ffERG response,diminished visual acuity,and cone and bipolar cell anomalies.Methods:We administered subretinal injections of a PEX1-containing viral vector(AAV8.CMV.hPEX1.HA)to 2 mouse cohorts of 5 or 9 weeks of age.A GFP-containing vector was used as a control in the contralateral eye of each animal.Efficient expression of the virus was confirmed by retinal histology/immunohistochemistry,and its ability to recover peroxisome import was confirmed in vitro.Preliminary ffERG and optokinetic(OKN)analyses were performed on a subset of animals at 8,16,and 20 weeks after gene delivery.Final ffERG and OKN measures were performed when each cohort reached 32 weeks of age(23 or 27 weeks post injection).Results:Preliminary ffERG and OKN analyses at 8 weeks post injection showed mildly better retinal response and visual acuity,respectively,in the PEX1-injected eyes,as did ffERG analysis when each cohort reached 25 weeks of age(16 or 20 weeks after gene delivery).This effect was more pronounced in the cohort treated at 5 weeks of age,when ffERG response is highest in Pex1-G844D mice.At 32 weeks of age,the ffERG response in the PEX1-injected eyes was double that of GFP-injected eyes,on average,though there was no change in OKN.Furthermore,in PEX1-injected eyes the photopic ffERG response improved over time,and the decline in scotopic b-wave amplitude was ameliorated compared to un-injected eyes.Conclusions:AAV8展开更多
文摘We have previously reported that the human ACAT1 gene produces a chimeric mRNA through the interchromosomal processing of two discontinuous RNAs transcribed from chromosomes 1 and 7. The chimeric mRNA uses AUG1397-1399 and GGC1274-1276 as translation initiation codons to produce normal 50-kDa ACAT1 and a novel enzymatically active 56-kDa isoform, respectively, with the latter being authentically present in human cells, including human monocyte- derived macrophages. In this work, we report that RNA secondary structures located in the vicinity of the GGC1274-1276 codon are required for production of the 56-kDa isoform. The effects of the three predicted stem-loops （nt 1255-1268, 1286-1342 and 1355-1384） were tested individually by transfecting expression plasmids into cells that contained the wild-type, deleted or mutant stem-loop sequences linked to a partial ACAT1 AUG open reading frame （ORF） or to the ORFs of other genes. The expression patterns were monitored by western blot analyses. We found that the upstream stem-loop1255-1268 from chromosome 7 and downstream stem-loop1286-1342 from chromosome 1 were needed for production of the 56-kDa isoform, whereas the last stem-loop135s-1384 from chromosome 1 was dispensable. The results of experi- ments using both monocistronic and bicistronic vectors with a stable hairpin showed that translation initiation from the GGC1274-1276 codon was mediated by an internal ribosome entry site （IRES）. Further experiments revealed that translation initiation from the GGC1274-1276 codon requires the upstream AU-constituted RNA secondary structure and the downstream GC-rich structure. This mechanistic work provides further support for the biological significance of the chimeric nature of the human ACAT1 transcript.
文摘Marek’s disease (MD) is a lymphoproliferative disease of domestic chickens caused by Marek’s disease virus (MDV), an oncogenic and highly contagious α-herpesvirus. MD has been controlled by vaccination but sporadic outbreaks of MD still occur in some parts of the world. Efforts to improve vaccine efficacy have continued in both research communities and vaccine industries. We reported the host genetic variation affecting Marek’s disease vaccine-induced immunity in chickens earlier. In this study, we evaluated chicken lines, vaccines, and line by vaccine interaction on the protective efficacy of vaccination against MD. Specific pathogen free chickens from the relatively resistant line 63 and the highly susceptible line 72 were primarily used to evaluate the protection by three kinds of vaccines (rMd5ΔMeq, CVI988/Rispens, and HVT) upon challenge with a very virulent plus strain of MDV, vv+648A. Our data confirmed that both the chicken line and the vaccine significantly affected the protective efficacy of vaccination and showed that a chicken line by vaccine interaction, in most of the trials, also altered vaccine protective efficacy. More interestingly, although the protective index of all vaccine strains was higher in resistant than in susceptible line of chickens, the difference for HVT protection was striking and warrants further study. The findings may have important implications for vaccine development as well as for selective use of particular vaccines in specific lines of chickens to achieve maximum protection at minimized costs.
文摘BACKGROUND The coronavirus disease 2019(COVID-19)pandemic altered education,exams,and residency applications for United States medical students.AIM To determine the specific impact of the pandemic on US medical students and its correlation to their anxiety levels.METHODS An 81-question survey was distributed via email,Facebook and social media groups using REDCapTM.To investigate risk factors associated with elevated anxiety level,we dichotomized the 1-10 anxiety score into low(≤5)and high(≥6).This cut point represents the 25th percentile.There were 90(29%)shown as low anxiety and 219(71%)as high anxiety.For descriptive analyses,we used contingency tables by anxiety categories for categorical measurements with chi square test,or mean±STD for continuous measurements followed by t-test or Wilcoxson rank sum test depending on data normality.Least Absolute Shrinkage and Selection Operator was used to select important predictors for the final multivariate model.Hierarchical Poisson regression model was used to fit the final multivariate model by considering the nested data structure of students clustered within State.RESULTS 397 medical students from 29 states were analyzed.Approximately half of respondents reported feeling depressed since the pandemic onset.62%of participants rated 7 or higher out of 10 when asked about anxiety levels.Stressors correlated with higher anxiety scores included“concern about being unable to complete exams or rotations if contracting COVID-19”(RR 1.34;95%CI:1.05-1.72,P=0.02)and the use of mental health services such as a“psychiatrist”(RR 1.18;95%CI:1.01-1.3,P=0.04).However,those students living in cities that limited restaurant operations to exclusively takeout or delivery as the only measure of implementing social distancing(RR 0.64;95%CI:0.49-0.82,P<0.01)and those who selected“does not apply”for financial assistance available if needed(RR 0.83;95%CI:0.66-0.98,P=0.03)were less likely to have a high anxiety.CONCLUSION COVID-19 significantly impacted medical students in nu
文摘Background:Zellweger spectrum disorder(ZSD)is an autosomal recessive disease caused by mutations in any one of 13 PEX genes whose protein products are required for peroxisome assembly.Retinopathy leading to blindness is one of the major handicaps faced by affected individuals,but treatment for this is supportive only.To test whether we could improve visual function in ZSD,we performed a proof-of-concept trial for PEX1 gene augmentation therapy using the Pex1-G844D mouse model,which bears the equivalent to a common human mutation.This model exhibits a gradual decline in scotopic ffERG response,an always residual photopic ffERG response,diminished visual acuity,and cone and bipolar cell anomalies.Methods:We administered subretinal injections of a PEX1-containing viral vector(AAV8.CMV.hPEX1.HA)to 2 mouse cohorts of 5 or 9 weeks of age.A GFP-containing vector was used as a control in the contralateral eye of each animal.Efficient expression of the virus was confirmed by retinal histology/immunohistochemistry,and its ability to recover peroxisome import was confirmed in vitro.Preliminary ffERG and optokinetic(OKN)analyses were performed on a subset of animals at 8,16,and 20 weeks after gene delivery.Final ffERG and OKN measures were performed when each cohort reached 32 weeks of age(23 or 27 weeks post injection).Results:Preliminary ffERG and OKN analyses at 8 weeks post injection showed mildly better retinal response and visual acuity,respectively,in the PEX1-injected eyes,as did ffERG analysis when each cohort reached 25 weeks of age(16 or 20 weeks after gene delivery).This effect was more pronounced in the cohort treated at 5 weeks of age,when ffERG response is highest in Pex1-G844D mice.At 32 weeks of age,the ffERG response in the PEX1-injected eyes was double that of GFP-injected eyes,on average,though there was no change in OKN.Furthermore,in PEX1-injected eyes the photopic ffERG response improved over time,and the decline in scotopic b-wave amplitude was ameliorated compared to un-injected eyes.Conclusions:AAV8
