Objective To analyze the genetic characteristics of measles virus in Sichuan province in 2015.Methods Measles virus was isolated from throat swab specimens collected from suspected measles cases.Nucleotide sequences coding for C terminus of nucleoprotein were amplified by RT-PCR and sequenced for phylogenetic analysis.Results 398 measles virus isolates were obtained from 971 throat swab specimens.Phylogenetic analysis showed that 397 belonged to H1 genotype,the sequences homologies were 96.2％-98.0％ compared with H1 genotype reference strain;and all those isolates separated into 2 clusters in phylogenetic tree with the average nucleotide divergence of 2.0％.1 isolate belonged to A genotype,and shared 98.0％ nucleotide homology compared with A genotype reference strain.Conclusions H1 genotype virus remained predominant circulating in Sichuan Province.There was no much genetic variation in N gene.But a minor nucleotide divergence existed between different clusters,leading to 2 transmission chains.

Objective To understand the genetic characteristics of rubella virus in Sichuan province in 2015.Methods Veto/SLAM cells were used for rubella virus isolation and culture.The 739 nucleotides of E1 gene was amplified by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and subjected to sequence and homological analysis.Results 19 strains of rubella virus were isolated and identified as genotype 2B.The homology of nucleotides and amino acids were 99％-100％ and 97.9％-100％,respectively.There were no changes in the important antigenic epitopes.Conclusions The rubella virus genotype circulated in Sichuan province in 2015 was genotype 2B.

Objective To investigate the levels of antibody to measles,rubella and mumps viruses in healthy population in Sichuan province,2018.Methods Totally 1 901 healthy people were selected from 7 age groups in 9 counties of Sichuan province.Serum samples of them were collected to test the IgG antibody to measles,rubella and mumps viruses by enzyme-linked immunosorbent assay (ELISA),and analyzed statistically.Results In 1 901 subjects,the positivity rates of measles,rubella and mumps IgG antibody were 83.69％,71.59％,63.12％ respectively,and the geometric mean titer (GMCs) were 1 289.92 mIU/ ml,87.63 IU/ml,and 425.62 U/ml respectively.There were significant differences in positivity rates of measles,rubella and mumps antibody among age groups and counties.There were no significant differences in GMCs of measles antibody among age groups and among counties,and the samples with full protection of measles (GMC≥ 1 000 mIU/ml) accounted for only 34.19％.There were significant differences in GMCs of rubella and mumps antibody among age groups and among counties.Conclusions The levels of antibody to measles,rubella and mumps were lower in healthy population in Sichuan.Vaccination should be strengthened in vulnerable areas and age groups.

Objective: To analyze the genetic characterization of glycoprotein M(gM.),glycoprotein L(gL) of varicella zoster virus. Methods: According to the program of "Ministry of Science and Technology of China" , Based on the 12 suspected VZV patients monitored in Beijing (1 case), Shanghai (5 cases), Jilin (2 cases), Qinghai (1 case), Guangdong (2 case) and Sichuan (case) in 2007-2015. A total of 12 Vesicle fluid and throat swab samples were collected. Positive samples were identified by Agarose gel electrophoresis and two glycoprotein genes were amplified by polymerase chain reaction (PCR). Nucleotide sequences were determined and analyzed by PCR amplification of VZV positive specimens V-OKA-BK of the domestic varicella attenuated live vaccine and the Varilrix-1 of the imported attenuated live vaccine. Nucleotide sequences of VZV positive specimens, vaccine strains (V-OKA-BK, varilrix-1) and GenBank foreign wild strains (41 strains), parent strains (P-oka), vaccine strains (V-oka, Varilrix, Varivax) were compared using BioEdit and MEGA 5.0. Results: 12 specimens were VZV positive. Compared with the vaccine strains and the parent strains, the GM gene of 1 positive specimen had radical mutation at 86686 sites, which resulted in amino acid mutation, 5 positive specimens had base mutation at 87844 sites, and 30 strains of foreign wild strains had the same variation at 87 844 sites. 1 positive specimens of gL gene in 101245 sites had base mutation, and led to amino acid mutation, 6 positive specimens at 101624, 101625, 101626 sites had base of loss and the foreign wild strains in these 3 sites had the same variation. Compared with the vaccine strains, the nucleotide and amino acid homology of gM of 12 VZV positive specimens were 99.2%-100% and 98.2%-100%, respectively, and gL of those were 99.3%-100% and 98.6%-100%, respectively. Compared with 41 strains of foreign wild strains, homology of gM's nucleotides and amino acid were 99.3%-100% and 98.5%-100%, respectively; 99.1%-100% and 98.6%-100% for gL. The results of phylogenetic analysis showed that 7 VZV positive samples were on the same branch with 4 vaccine strains and p-oka strain. Based on gL, 12 VZV positive samples were on the same branch as the vaccine strains and p-oka strain. Conclusion This study demonstrates that the genes of gM, gL are highly conserved and remain stable immunogen, which may be involved in the attenuation of VZV and need to be further researched.

The lung is an important organ in systemic toxicity test of medical devices and is significant in safety evaluation. Based on the authors' understanding of medical devices, this study provides a brief analysis of the lung examination and common problems in systemic toxicity, so as to provide references for the pre-clinical safety evaluation of medical devices. It should be noted that a reasonable risk assessment should be made after comprehensive assessment for specific medical device products.
Equipment Safety ; Humans ; Lung ; Risk Assessment