Objective To investigate the sequences of the 3' end of genomes from enterovirus 71 isolated from pediatric patients with different symptoms in Beijing during 2008-2009.Methods Clinical specimens were collected from pediatric patients suffering from hand,foot and mouth disease(HFMD)and/or with neurological complications who visited the affiliated Children's Hospital during the epidemic seasons of 2008 and 2009 in Beijing.The samples were inoculated into the Vero cell line,and the virus isolates were further identified by nested reverse transcription-nested PCR(RT-nPCR)assay using universal enterovirus primers,type specific primers for EV71 and CA16.The 3' end of genomes(including 3D and 3' UTR regions)from 10 EV71 strains derived from various clinical presentations were amplified and sequenced.Results Analysis of the nucleotide sequences of the amplified fragments showed that the 3' end of genomes of 10 EV71 isolates include the 3D region of 1386 nucleotides(nt)encoding the 3D polymerase(3Dpol,462 amino acids),the terminator codon TGA and 3' UTR of 81 nt.Nucleotide sequence identities among 3D regions from these 10 EV71 isolates were in the range of 95.8%-99.6%,while the nucleotide sequence identities for 3' UTR were 96.3%-100%.The majority of nucleotide changes were located at the third codon positions which caused silent mutations,thus the amino acid sequence changes of 3Dpol among those 10 EV71isolates were scanty.The residues 140 and 263 which were R and 1 were substituted by K and V,respectively in 3 of 4 neurovirulent strains,whereas only 1 of 6 strains from mild cases had these 2 amino acid changes.The sequences of the 3D and 3' UTR regions of 10 EV71 isolates were compared to the representative strains of known genotypes from the GenBank.The nucleotide and amino acid sequences of 10 EV71 isolates in the 3D region exhibited highest homology to the subgenotype C4 of EV71(92.7%-94.2%and 96.8%-97.6%.respectively).However,3' UTR of 10 EV71 isolates shared the highest nucleotide identity with CA16/G10(88.9%-91.4%).The phylogenetic analysis based on the 3D regions demonstrated that 10 EV71 isolates had the closest genetic relationship with the representative isolate of CA sub-genotype of EV71 and shared more homology with CA16/G10 than other known genotypes of EV71.Conclusion Genetic analysis of the 3' end of genomes from 10 EV71 strains indicated that the 3' end of genome may play a role in the evolution of EV71.

OBJECTIVETo analyze the genotype, epidemic pattern and the characteristics of the disease of enteroviruses during the epidemic season of hand, foot and mouth disease (HMFD) in children from 2013 to 2014 in Beijing to provide the scientific evidence for prevention and treatment of HFMD.

METHODDuring April to September in 2013 and March to October in 2014, a total of 977 throat swabs were collected from children who visited the Children's Hospital Affiliated to Capital Institute of Pediatrics, including 147 from patients with HFMD in 2013, 343 with HFMD, 201 with atypical HFMD, 83 with herpangina, 25 with fever with convulsions, 64 fever with rash and 114 with rash in 2014. Enteroviruses universal type (EV), Enteroviruses type 71 (EV71) and Coxsackievirus group A 16 (CA16) were detected by real-time RT-PCR respectively. The nucleic acid of specimens which were identified with non-EV71, non-CA16 was tested by nested PCR and analyzed by VP1 sequencing. The detection rate and epidemic pattern of different genotypes of enterovirus were analyzed among different age groups and between 2013 and 2014.

RESULTOf 977 throat swabs, 80. 1% samples were detected positive for enteroviruses. The positive rates of CA16, EV71, CA6, CA10, CA4 and other EVs were 25. 6% (250/977), 18. 9% (185/977), 20. 0% (195/977), 5. 0% (49/977), 1.5% (15/977) and 9.1% (89/977), respectively. Twenty six of the 89 other EVs included CA2, CA5, CA8, CA9, CA12, CA14, CB2, CB5, E6, E9 and E25, each genotype of which was no more than 3. The nucleotide homologies shared among CA6, CA10 and CA4 strains between 2013 and 2014 were 94. 3% - 100%, 93. 8% - 99. 1% and 92.7% - 99. 8%, respectively. The positive rates of ≤1 year group were 71. 1% (106/149), which was lower than that of other age groups (all P <0. 05), but similar to that of >5 year group (χ2 =1. 181,P = 0. 277). In 2013, the positive rate of EV was 85. 7% (126/147) and the predominant genotype was CA6 54. 8% (69/126), followed by CA16 20. 6% (26/126) and EV71 11. 9% (15/126). In 2014, the positive rate of EV was 85. 4% (293/343) in the 343 children with HFMD, the predominant genotypes were CA16 with the positive rate of 42. 7% (125/293), EV71 with 38. 2% (112/293) and CA6 with only 11. 3% (33/293). In 2014, the positive rates of EV in 201 atypical HFMD, 83 herpangina, 25 fever with convulsions, 64 fever with rash and 114 rash were 83. 6% (168/201), 80. 7% (67/83), 76. 0% (19/25), 64. 1% (41/64) and 60. 5% (69/114), respectively. All genotypes of enteroviruses peaked mainly during May to August every year, but there were no obvious epidemiological pattern about each genotype.

CONCLUSIONCA6 became the main causative agent of HFMD in 2013, however, CA16 and EV71 predominated again in 2014 in Beijing. The clinical manifestations caused by CA6, CA10, CA4 and other genotype of enteroviruses differed from EV71 and CA16. Besides EV71 and CA16, more attention should be paid to CA6, CA10, CA4 and other type of enteroviruses.

Beijing ; epidemiology ; Child, Preschool ; Enterovirus A, Human ; classification ; Enterovirus Infections ; epidemiology ; virology ; Exanthema ; Fever ; Genotype ; Hand, Foot and Mouth Disease ; epidemiology ; virology ; Humans ; Infant ; Real-Time Polymerase Chain Reaction

Objective To investigate the etiological agents of hand, foot and mouth disease (HFMD) in children in spring and summer from 2007 to 2008 in Beijing and the characteristics of the disease by virus isolation and to provide the scientific evidence for prevention and treatment for HFMD. Methods During April to August, 2007 and May to September, 2008, 356 clinical specimens including 255 throat swabs and 101 vesicle fluids were collected from 256 patients with HFMD who visited the Children's Hospital Affiliated to Capital Institute of Pediatrics and children with severe HFMD with neural system complications from Ditan Hospital and Youan Hospital All of the specimens were inoculated into Vero cells for virus isolation. After the cell pathogenic effects (CPE) appeared, the isolates were identified by RT-PCR with the universal primers within 5'untranslated region of enterovirus and typed by specific primers for VP1 gene of EV71 and CA16, respectively. The throat swabs from all of 10 severe HFMD were tested for enterovirus by RT-PCR addition to virus isolation. Results Out of 256 patients, 188 were positive for enterovirus by virus isolation, with the overall positive rate of 73.4%. Among the 356 clinical specimens collected from these 256 patients, 239 enterovirus strains were isolated with the overall positive rate of 67.1%. The positive rate for virus isolation from vesicle fluid samples was 75.2% which was higher than the positive rate of isolation from throat swabs (63.9%), but the time for CPE appearing in cell culture showed no significant difference. The positive rate of virus isolation from throat swabs from children with severe HFMD was 50% (5/10) which was lower than overall positive rate (73.4%) from regular HFMD. The RT-PCR typing for virus isolates revealed that among 45 enterevirus strains isolated from the specimens collected in 2007 by the universal primer pairs, 43 were CAI6 (95.6%, 43/45) and 2 were EV71 (4.4%, 2/45), whereas for the specimens collected in 2008, out of 143 enterovirus isolates by PCR with universal primers, 117 were EV71 (82.4%, 117/142) and 24 were CA16 (16.8%, 24/142). All of 10 severe cases were positive for EV71 by RT-PCR directly from clinical specimens. Conclusion CA16 and EVT1 were the etiological pathogens of HFMD in Beijing during 2007 to 2008 HFMD seasons. The dominant type of enterovirus was different between 2007 and 2008. Enterovirus type CA16 was predominant in 2007, whereas EV71 was predominant in 2008. All of severe cases of HFMD in children in this study were caused by EV71.

Objective To develop a convenient reverse transcription PCR(RT-PCR)method for identifying genotypes of human metapneumovirus(hMPV)from clinical samples.Methods According to the gene sequences of hMPV G with different genotypes,the A and B genotype specific primers were designed.A diplex RT-PCR was applied to identify different genotypes according to the molecular weight of PCR products in agarose gel.37 clinical samples were detected through this method.Results It was convenient to distinguish different genotypes of hMPV(383 bp for A and 284 bp for B)by the diplex RTPCR,and there was no non-specific amplification for common respiratory viruses.so it meant that the specificity of primers was good.The results of genotyping 37 clinical samples showed that 20 samples were identified as genotype A by both sequence analysis of M gene and diplex RT-PCR,whereas 17 samples were identified as genotype B by sequence analysis of M gene.but in these 17 samples 14 samples were identified as genotype B by the diplex RT-PCR and remaining 3 samples could not be genotyped because there was no PCR product after amplification.The consistency rate for these two methods Was 91.9%[(20+14)/37].Conclusion The method of diplex RT-PCR Was developed successfully and can be used for identify genotypes of hMPV.

BACKGROUND: In vitro differentiation of embryonic stem cells into hepatocytes has been successfully reported to a certain degree; however, whether embryonic stem cells are able to effectively enter hepatic plate of host after intrahepatic transplantation, whether embryonic stem cells can further differentiate into hepatocytes and express hepatocyte function, and risk factors for neoplastic formation are still unclear at present. OBJECTIVE: To study the intrahepatic transplantation of embryonic stem cells-derived hepatic stem cells in therapeutic liver repopulation models, and to investigate the liver tissue replacement, growth and differentiation in vivo, and neoplastic formation.DESIGN: Randomized controlled animal study.SETTING: Department of Pediatric Surgery, the Second Hospital affiliated to Sun Yat-sen University. MATERIALS: Twenty-four BALB/c mice, 6-8 weeks old, weighing 20-35 g, irrespective of gender, were provided by Guangzhou Experimental Animal Center. Embryonic stem cells-derived hepatic stem cells were differentiated from embryonic stem cells. E14 was provided by Stem cell Center of our hospital. METHODS: This study was performed at the Stem Cell Center, the Second Hospital affiliated to Sun Yat-sen University from July 2006 to June 2007. Twenty-four mice were randomly divided into a liver repopulation model + stem cell transplantation group (group A) and a liver resection + stem cell transplantation group (group B), with 12 mice in each group. Mice in the group A were intraperitoneally injected with 50 mg/kg retrorsine once every two weeks for totally twice. Four weeks after the second injection, about 70% liver was resected. And then, the embryonic stem cells-derived hepatic stem cells, labeled by 1×105 carboxy fluoresce in diacetate succinimidyl ester (CFDA-SE), were transplanted into mouse liver through portal vein. On the other hand, 70% liver of mice in the group B was resected and embryonic stem cells-derived hepatic stem cells were transplanted into mouse liver. MAIN OUTCOME MEASURES: The distribution, incorporation, and proliferation of transplanted cells were observed under fluorescent microscopy. Two weeks later, hepatic function was stained with albumin fluorescence immunoassay (double fluorescence staining) and assayed by level of serum albumin. Embryonic stem cells-derived hepatic stem cells were poured into liver of remedial liver regeneration mice, and undifferentiated embryonic stem cells were transplanted into subcutaneous tissue in axillary region as the controls to observe neoplastic formation in embryonic stem cells-derived hepatic stem cells. RESULTS: ① Growth of hepatic stem cells in recipient mice: One week after transplantation of CFDA-SE-labeled embryonic stem cells-derived hepatic stem cells, some scattered region was green under fluorescent microscopy. The area of green region increased apparently in 2 weeks, and cord-like structure could be observed. ② Liver function: Immunofluorescent staining of albumin (double fluorescence staining) demonstrated that labeled cells expressed positive albumin (yellow fluorescence) in liver tissue of recipient mice, but there was not significant difference in serum albumin level between group A and group B (P > 0.05). ③ Reliability of hepatic stem cell transplantation: Teratoma did not form over 6 months; however, transplantation of undifferentiated embryonic stem cells in the axillary region could cause formation of teratoma after 6 weeks. CONCLUSION: The transplantation of embryonic stem cells-derived hepatic stem cells in therapeutic liver repopulation model mice can effectively and further grow and differentiate, or even partially express hepatocyte function; in particular, the transplantation is safe.

Objective To explore the value of echo-tracking technique in the detecting the ipsilateral external iliac artery elasticity after gunshot wound in pig limbs.Methods Two-dimensional ultrasound imagings and elasticity parameters of external iliac artery of fifteen pig limbs were obtained respectively,and the results were compared with pre-injury groups.The animals were sacrificed after ultrasonography.Pathological examinations of adjacent external iliac artery of injured pig limbs were analyzed.Results Two-dimensional ultrasound imagings of external iliac arteries had no significant changes post-injury.The changes of elasticity parameters were significiant differences in the injured group comparing with the pre-injured group (P ＜0.05),including the increased stiffness parameter(β),pressure-strain elasticity modulus (Ep)and the decreased arterial compliance(AC).Pathological result showed that the internal elastic lamina of artery detected were flat,endothelial cells came off discontinuously and structure of them were undefined.Conclusions Echo-tracking technique can find the elastic changes of adjacent artery indirect injured by gunshot wound sensitively and which can suggest the occurrence of vascular indirect injury.

0.05).No teratoma was formed in the experimental group,while a large teratoma was observed in control group in 6 weeks post-transplantation.CONCLUSION:The ESC-derived hepatic stem cells are normally incorporated into mouse liver parenchymal structure,proliferate and differentiate further in vivo and possess some hepatic functions without forming teratomas.

The development of the healthcare industry puts forward higher and higher standards on the medical education, so an effective education management mode is needed urgently for medical schools to promote the cultivation of undergraduate medical students. Tutorial system has a positive effect in building the innovative thinking, critical thinking and clinical thinking of medical students. It also helps students' innovation ability training. This paper first introduces the overview of the implementation of tutorial system in medical colleges, and then expounds the specific implementation measures of the undergraduate tutorial system in the Third Military Medical University. Investigation data shows that, accompanied with these mea-sures, the numbers of article publishes and the achievements in various competitions have been raised whereas the psychological counseling needs decreased, indicating that the tutorial system has a strong posi-tive influence on the development of medical students.

Background Acute respiratory infection (ARI) is one of the most common infectious diseases in infants and young children globally.This study aimed to determine the virus profile in children with ARI presenting with different severities.Methods Clinical specimens collected from children with ARI in Beijing from September 2010 to March 2011 were investigated for 18 respiratory viruses using an xTAG Respiratory Viral Panel Fast (RVP Fast) assay.The Pearson chisquare analysis was used to identify statistical significance.Results Of 270 cases from three groups of ARI patients,including Out-patients,In-patients and patients in the intensive care unit (ICU),viruses were detected in 176 (65.2％) specimens with the RVP Fast assay.The viral detection rate from the Out-patients group (50.0％) was significantly lower than that from the In-patients (71.1％) and ICU-patients (74.4％) groups.The virus distribution was different between the Out-patients group and the other hospitalized groups,while the virus detection rate and distribution characteristics were similar between the In-patients and ICU-patients groups.The coinfection rates of the Out-patients group,the In-patients group,and the ICU-patients group were 15.6％,50.0％ and 35.8％,respectively.In addition to respiratory syncytial virus (RSV) and adenovirus (ADV),human rhinovirus (HRV) was frequently detected from children with serious illnesses,followed by human metapneumovirus (hMPV),human bocavirus (HBoV) and coronaviruses.Parainfluenza virus 3 (PIV3) was detected in children with lower respiratory illness,but rarely from those with serious illnesses in the ICU-patient group.Conclusion In addition to so-called common respiratory viruses,virus detection in children with ARI should include those thoucht to be uncommon respiratory viruses,especially when there are severe ARI-related clinical illnesses.

Objective To find out the importance of human bocavirus (HBoV) as an infectious agent for population in Beijing, China. Seroprevalence study was conducted by using expressed recombinant major capsid VP2 protein as an antigen.Methods Serum specimens collected from infants and children who visited the Children's Hospital Affiliated to the Capital Institute of Pediatrics for health check-up and adults visiting the Xuanwu Hospital, Beijing for diseases other than respiratory infections from April 1996 to March 1997 were used for the investigation. The major capsid protein VP2 from HBoV was expressed in E. coli strain BL21 (DE3) with the transformed PET30b vector inserted with full-length VP2 gene of HBoV and the specific antigenicity of this expressed protein was validated by previous study. Western blotting was used to detect specific IgG antibody against HBoV in collected serum specimens diluted to 1:200. Mock expressed protein was E. coli cells strain BL21 (DE3) with the transformed PET30b vector without insert. Anti-His monoclonal antibody and rabbit anti-HBoV VP2 polypeptides hyper-immune serum were used as positive control for antibody detection.Results Out of 677 serum specimens tested, 400 (59.1% ) were positive for HBoV by Western blotting. About 45.3% (34/75) of the newborns under 1 month of age had anti-HBoV antibodies, and antibody positive rates were decreased in age groups of 1 and 2 months (41.4% and 31.3%, respectively) then increased in the following ages from 6 months to 7 years old ( from 45.6% to 69.7% ). The antibody positive rates were maintained at a relatively constant level ( about 70% ) in the age groups from 7 years to 40 years of age and became lower ( 61.8% - 62. 8% ) in those over 50 years.Conclusions The high seroprevalence of antibody against recombinant HBoV VP2 protein and early age antibody acquisition indicate that HBoV has been circulating in population of Beijing, China as early as in 1996 and most of children had been exposed to HBoV by the age of 7 years. Infants under the age of 6 months were susceptible to this virus.