ABSTRACT
Objectives To study the effect of VIM in Enterovirus 71 (EV71) infection of (human brain microvascular endothelial cells (HBMEC) and elaborating the mechanism of EV71 infection in the nervous system. Methods Knocked out the VIM by CRISPR technology , the differences in EV71 absorption , replication , release between wild VIM and VIM knocked-out (VIM-KO) HBMEC were detected by fluorescence quantitative PCR. Results 4 ℃ absorption experiment conformed that EV71 adsorption in VIM- KO is 40% less than in the normal HBMEC. After EV71 infect HBMEC for 48 h (48 h p. i.), the quantitative PCR result showed intracellular viral RNA in VIM-KO was only 1/12 of that in the normal HBMEC. Also the extracellular viral RNA was quantified, and the number of cells in VIM-KO had been reduced 1.4 times compared with the normal HBMEC. Conclusions Once VIM knocking out, EV71 attachment has been obviously reduced. Meanwhile, the level of viral RNA replication and release are decreased compared with the normal HBMEC. VIM may be an attachment receptor of EV71 in HBMEC , when the virus invades HBMEC with the binding of VIM. Moreover , VIM plays an important role in the replication and release of EV71.
ABSTRACT
Objective To study the factors influencing epidemiological characteristics and virulence of Enterovirus 71 (EV71) in Guangdong province from 2008 to 2010. Methods RNA was extracted from collected samples or cultured virus , then reversing transcription into cDNA. We amplified full-length EV71-VP1 using poly-merase chain reaction technology , then conducted sequence alignment and established phylogenetic tree with MEGA software (version 5.0) to confirm the genotype of EV71. The association between severity of clinical symp-toms and sex, age, viral genotype and VP1 variation was also analyzed using Logistic regression. Results The genotype of the predominant epidemical strain was C4a in Guangdong from 2008 to 2010. However , this subtype had already differentiated into 4 subgroups (C4a1- C4a4). There was no correlation between clinical syndrome and sex or viral genotype; the severity of symptoms was negatively correlated with age: before 4 years old, varia-tion A289T can easily lead to severe cases, increasing the risk of infection (P<0.05, OR = 2.360, 95%CI:1.163~ 4.659). Conclusion The main epidemical EV71 strain is C4a1 in Guangdong province. The emerging differen-tiation and simultaneous prevalence should merit attention to strengthen relevant surveillance; and the protection of the susceptible population should be reinforced during EV71 prevalence.
ABSTRACT
Objective To study the dilution model of the early pregnancy test strip for the quantitative detection of serumβ-hu-man chorionic gonadotropin(β-hCG)level by the Abbot AxSYM detection system and its application.Methods The detection re-sults of serumβ-hCG level in 5 612 outpatients and inpatients of the internal medicine department and the gynecology and obstetrics department during 5 years were retrospectively analyzed.In addtion,234 serum samples from the patients were collected for prelimi-narily determining the serumβ-hCG level by the early regnancy test strip and then the quantitative detection of serumβ-hCG level was detected by the Abbot AxSYM detection system.Results The retrospective analysis showed that 241 cases(4.6%)were low-age pregnant women.The qualitative screening was necessary.The screening model was successfully established.But one thing to note was that the part of serum sample needed to be taken out and put into another tube for determination.Conclusion Establishing the rational and effective dilution interpretation model of early pregnancy test strip for screening serumβ-hCG can bring the econom-ic and time benifits for the routine detection work of the Abbot AxSYM detection system.