Objective:To investigate the level of serum-neutralizing antibodies against Coxsackievirus A6 (CVA6) in a healthy population in Tianjin City from 2014 to 2020.Methods:From March 2014 to March 2020, 5 492 healthy volunteers were recruited in Tianjin City. The demographic information, personal hygiene habits, living environment hygiene, contact history with hand, foot and mouth disease cases within 6 months before the survey, history of upper respiratory tract infection, and medical history of the subjects were investigated using a self-designed questionnaire. Venous blood was collected from the volunteers, and the level of serum anti-CVA6 IgG neutralizing antibodies was determined by the micro-neutralization assay. The level of CVA6-neutralizing antibodies was compared in different years, regions, and age groups, and the influencing factors in healthy individuals were analyzed by an ordered logistic regression model.Results:The age of 5 492 healthy volunteers ranged from 0 to 77, with M ( Q1, Q3) of age being 21 (7, 32) years old, and a male-to-female ratio of 1∶1.09. The high, medium and low levels of CVA6-neutralizing antibodies among the volunteers were 5.39% (296), 30.35% (1 667) and 64.26% (3 529). The proportion of volunteers with high levels of CVA6-neutralizing antibodies decreased from 54.63% (437/800) in 2014 to 30.01% (229/763) in 2020, and it also decreased with age (all P values <0.001). The results of the ordered logistic regression model analysis showed that compared with those aged >35 years, volunteers aged 0-5 years had higher levels of CVA6-neutralizing antibodies [ OR (95% CI): 1.39 (1.16-1.67)]. Compared with those who did not wash their hands after going out and had poor living environments, volunteers who washed their hands after going out, had good and general living environments and had lower levels of CVA6-neutralizing antibodies [ OR (95% CI): 0.80 (0.70-0.91), 0.52 (028-0.88) and 0.54 (0.31-0.96), respectively]. Conclusion:The level of CVA6-neutralizing antibodies in Tianjin City remains at a relatively high level from 2014 to 2020 and shows a decreasing trend over the years.

Objective:To investigate the level of serum-neutralizing antibodies against Coxsackievirus A6 (CVA6) in a healthy population in Tianjin City from 2014 to 2020.Methods:From March 2014 to March 2020, 5 492 healthy volunteers were recruited in Tianjin City. The demographic information, personal hygiene habits, living environment hygiene, contact history with hand, foot and mouth disease cases within 6 months before the survey, history of upper respiratory tract infection, and medical history of the subjects were investigated using a self-designed questionnaire. Venous blood was collected from the volunteers, and the level of serum anti-CVA6 IgG neutralizing antibodies was determined by the micro-neutralization assay. The level of CVA6-neutralizing antibodies was compared in different years, regions, and age groups, and the influencing factors in healthy individuals were analyzed by an ordered logistic regression model.Results:The age of 5 492 healthy volunteers ranged from 0 to 77, with M ( Q1, Q3) of age being 21 (7, 32) years old, and a male-to-female ratio of 1∶1.09. The high, medium and low levels of CVA6-neutralizing antibodies among the volunteers were 5.39% (296), 30.35% (1 667) and 64.26% (3 529). The proportion of volunteers with high levels of CVA6-neutralizing antibodies decreased from 54.63% (437/800) in 2014 to 30.01% (229/763) in 2020, and it also decreased with age (all P values <0.001). The results of the ordered logistic regression model analysis showed that compared with those aged >35 years, volunteers aged 0-5 years had higher levels of CVA6-neutralizing antibodies [ OR (95% CI): 1.39 (1.16-1.67)]. Compared with those who did not wash their hands after going out and had poor living environments, volunteers who washed their hands after going out, had good and general living environments and had lower levels of CVA6-neutralizing antibodies [ OR (95% CI): 0.80 (0.70-0.91), 0.52 (028-0.88) and 0.54 (0.31-0.96), respectively]. Conclusion:The level of CVA6-neutralizing antibodies in Tianjin City remains at a relatively high level from 2014 to 2020 and shows a decreasing trend over the years.

Abstract: Objective　To genotype and analyze whole genomic features of Coxsackievirus B3 (CVB3) isolated in Tianjin, to improve evolution information of CVB3 virus in Tianjin, and to provide basis for surveillance and early warning of related diseases. Methods　Viral RNA was extracted from five CVB3 strains isolated in Tianjin, whole genome sequence of the virus was amplified by RT-PCR and sequenced by next-generation sequencing method, and phylogenetic and recombinant analysis were carried out. Results　The open reading frame 1(ORF) of the five CVB3 strains contained 6 555 nucleotides and encoded 2 185 amino acids, and ORF2 was composed of sequences encoding 68 amino acids. The nucleotide sequence similarity ranged from 78.3%-100%, and the amino acid sequence similarity ranged from 95.7%-100%. Compared with the CVB3 prototype strain, the nucleotide sequence similarity of the five viruses was between 78.2%-79.1%, and the similarity of amino acid sequences was 94.9%-95.3%. All five viruses exhibited a T151A mutation on the VP2 protein. Additionally, the encephalitis isolate showed a K158E mutation on the VP2 protein, while one of the sewage isolates had a C234T mutation in 5' noncoding region. The five strains belonged to two different genotypes, among which the encephalitis isolate in 2016 belonged to the D genotype, while the sewage isolates in 2021 belonged to the E genotype. This is also the first report of E genotype CVB3 in northern China. The CVB3 strain may have recombinant events in non-structural protein regions, in which encephalitis isolate may recombine with a Coxsackievirus B5 (CVB5) strain, while sewage isolates may have recombinant events with a strain of ECHO virus 18 (E18). Conclusions　The CVB3 isolates in Tianjin belong to D and E genotypes, and recombination events may exist in non-structural protein region of the viral genome. The results of CVB3 virus genome analysis in sewage suggests presence of CVB3 infection in the population of Tianjin, and its epidemic dominant genotype may have changed.

Objective:To study the characteristics and evolution of the whole genome sequence of an imported Chikungunya virus (CHIKV) case in Tianjin, China, and to provide a scientific basis for the surveillance and control of CHIKV.Methods:The serum specimen of CHIKV was collected at Tianjin Second People's Hospital, on November 4th, 2019, and the viral RNA was extracted. Eleven overlapping primers were used to amplify the complete genome of CHIKV by RT-PCR. The amplification products were then subjected to next generation sequencing (NGS) using Illumina Miniseq platform.Results:The complete genome sequence of the Tianjin CHIKV obtained had similarities ranging from 92.72% to 99.86% with other Chinese isolates. Phylogenetic analysis indicated that the Tianjin CHIKV belonged to the Indian Ocean Lineage (IOL), East/Central/South African (ECSA) cluster, consistent with most strains from China. The Tianjin CHIKV is most similar (99.74%) to a Pakistan strain. Compared with the reference strain S27, 37 non-structural and 28 structural protein amino acid substitutions had been detected in Tianjin CHIKV genome, including two key site mutations, E1-D284E and E2-I211T, in accordance with other strains in the ECSA cluster. Besides, Tianjin CHIKV possessed two point virulent residues at position 12 and 82 in E2, and also a nsP3-R524Opal nonsense mutation.Conclusions:Tianjin CHIKV showed stronger virulence and greater transmissibility in Aedes albopictus. Therefore, the surveillance and monitoring of CHIKV in China should be strengthened.

Objective:To analyze the whole genome traceability and variation analysis of SARS-CoV-2 in local COVID-19 outbreaks in Binhai New Area, Tianjin.Methods:The whole-genome high-throughput sequencing was performed on throat swab samples collected from one local asymptomatic infected person and five confirmed cases of COVID-19 in Binhai New Area of Tianjin from November 7 to December 5, 2020. The sequencing data were assembled by De novo. MAFFT v7.0 multiple sequence alignment program and MEGA X software were used to compare the above data and construct phylogenetic tree (Neighbor-joining method).Results:The genetic similarity between the sequences of 6 SARS-CoV-2 strains and Wuhan reference sequence (Wuhan-Hu-1) was greater than 99.9%. Two of six strains were genetically identical, conform to the L-Lineage European Branch Ⅱ.1(America Branch)/B.1; The other four strains had the same genes and were in line with the characteristics of L-Lineage European Branch Ⅰ/B.1.1.These six strains belonged to different evolutionary branches and two different transmission chains. There were 18 nucleotide mutation sites in sequences of six SARS-CoV-2 strains, eight of which were synonymous mutation sites, nine of which were missense mutation sites, resulting in nine amino acid mutation sites, and important mutation sites of RDRP-P323L and S-D614G were found in all of the six samples.Conclusions:In this study, there were two COVID-19 outbreaks in Binhai New Area of Tianjin, and the sequences of six SARS-CoV-2 strains belonged to different evolutionary branches and two different transmission chains. It might come from porters′ contact with imported cold chain items contaminated with SARS-CoV-2 from different sources. All the sequences of six SARS-CoV-2 strains had P323L and D614G mutations, which indicated that the virus mutation and transmission ability were stronger. The surveillance of important employees of the cold chain in Tianjin and local and imported cases should be continuously strengthened.

Objective:To collect the upper respiratory tract specimens from both domestically-spread and imported Coronavirus Disease 2019 (COVID-19) confirmed cases, sequence the whole genome of 2019 novel coronavirus (2019-nCoV) and analyze the genetic variation and the phylogenetic characteristics.Methods:The viral nucleic acids of all specimens were extracted, the sequencing library was constructed following the manufacturing instructions, and the sequencing data were analyzed by bioinformatics software.Results:The whole genomes of 2019-nCoV strains from 24 samples were all obtained and had high similarity with the genome of the reference strain Wuhan-Hu-1 (GenBank ID: NC_045512) and the similarity rates were all greater than 99.9%. Six 2019-nCoV strains from domestically-spread cases were classified into L-lineage and the others were S-lineage. The 2019-nCoV strains from the imported cases had 48 nucleotide mutation positions, but those from the domestically-spread cases only had 14 mutation positions. Most of 2019-nCoV strains from the imported cases (15/16) had the specific D614G mutation site in spike protein, while those from the domestically-spread cases had none.Conclusions:The 2019-nCoV strains from the imported cases in Tianjin city had more mutation sites than those from the domestically-spread cases, and most of 2019-nCoV strains from the imported cases had D614G mutations in spike protein which had more transmissive rates and were easier to spread among humans.

Objectives:A clinical case caused by Chikungunya virus (CHIKV) was introduced into Tianjin, China from Myanmar. The current study is aimed to phylogenetically analyzing this imported strain and to reveal the relationship between this virus and other circulating CHIKV strains.Methods:RNA was extracted from serum of the suspected patient presenting with symptoms compatible with CHIKV infections. Real-time reverse transcription PCR (RT-PCR) assay was used for diagnoses of the patient. For phylogenetic analysis, envelope glycoprotein 1 (E1) gene of CHIKV was amplified by two-step RT-PCR and the products were sequenced.Results:The phylogenetic analyses revealed that the imported CHIKV belong to Indian Ocean Lineage (IOL) derived from ECSA genotype and sharing the same cluster with the Aede albopitus-adapted strains that triggered the outbreaks in Pakistan (2016), Italy (2017) and Bangladesh (2017). Conclusion:The imported CHIKV strain has the potential to cause explosive outbreaks in China and this event happened in Tianjin calls for strengthening the monitoring programs on mosquito-borne diseases in China.

Objective To analyze the effect of extralateral approach interbody fusion in the treatment of degenerative lumbar diseases. Methods A total of 50 patients with lumbar degenerative diseases admitted to our hospital were selected, and were treated with extralateral approach interbody fusion, and the therapeutic effect was observed and analyzed. Results All patients successfully completed the operation. The average amount of bleeding during operation was (145. 5 ± 4. 7) m L, the average operation time was (56. 3 ± 2. 2) min, and the average hospitalization time was (7. 2 ± 1. 5) days. Four patients suffered from hip flexion weakness after operation, and the symptoms recovered completely after two months. Six patients suffered from sensory numbness in front of thighs after operation, and the symptoms disappeared or relieved after 6 to 8 weeks. No complications such as abdominal organs and blood vessels injury, cerebrospinal fluid leakage, mislocation of intervertebral space, paralytic intestinal obstruction and permanent injury of genitofemoral nerve occurred. All patients were followed up for 24 months. The results showed that at the last follow-up, the Visual Analogue Scale (VAS) scores of low back pain and lower limb pain were significantly lower, and the lumbar spine scores of Japanese Orthopaedic Association (JOA) were significantly higher than before operation (P ＜ 0. 05). Conclusion Extralateral approach interbody fusion can achieve satisfactory results in the treatment of lumbar degenerative diseases, with fewer complications and higher fusion rate.

Objective To analyze the effect of extralateral approach interbody fusion in the treatment of degenerative lumbar diseases. Methods A total of 50 patients with lumbar degenerative diseases admitted to our hospital were selected, and were treated with extralateral approach interbody fusion, and the therapeutic effect was observed and analyzed. Results All patients successfully completed the operation. The average amount of bleeding during operation was (145. 5 ± 4. 7) m L, the average operation time was (56. 3 ± 2. 2) min, and the average hospitalization time was (7. 2 ± 1. 5) days. Four patients suffered from hip flexion weakness after operation, and the symptoms recovered completely after two months. Six patients suffered from sensory numbness in front of thighs after operation, and the symptoms disappeared or relieved after 6 to 8 weeks. No complications such as abdominal organs and blood vessels injury, cerebrospinal fluid leakage, mislocation of intervertebral space, paralytic intestinal obstruction and permanent injury of genitofemoral nerve occurred. All patients were followed up for 24 months. The results showed that at the last follow-up, the Visual Analogue Scale (VAS) scores of low back pain and lower limb pain were significantly lower, and the lumbar spine scores of Japanese Orthopaedic Association (JOA) were significantly higher than before operation (P ＜ 0. 05). Conclusion Extralateral approach interbody fusion can achieve satisfactory results in the treatment of lumbar degenerative diseases, with fewer complications and higher fusion rate.

OBJECTIVETo evaluate the effects of polymorphisms in XRCC1 and APE1 genes on vinyl chloride (VC)-induced chromosomal damage in peripheral lymphocytes.

METHODSIn this study, 317 workers occupationally exposed to VC were recruited from a factory in Shandong Province, China. The micronucleus (MN) frequency in peripheral lymphocytes was used as an indicator of chromosomal damage. Polymerase chain reaction-restriction fragment length polymorphism and created restriction site combined with restriction fragment length polymorphism were used to determine the five single nucleotide polymorphisms in XRCC1 and APE1 genes in the base excision repair pathway. The association of chromosomal damage with these polymorphisms and the haplotype of XRCC1 was analyzed using Poisson regression and PHASE 2.0.2.

RESULTSIt was found that among the VC-exposed workers, individuals with XRCC1 polymorphisms (-77C/T, Arg194Trp, Arg280His, and Arg399Gln) had a significantly higher MN frequency than those with homozygous wild-type genotypes, with frequency ratios (FR) as follows, respectively: FR = 1.21, 95%CI: 1.05∼1.39 (P < 0.05); FR = 1.14, 95%CI: 1.00∼1.38 (P < 0.05); FR = 1.26, 95%CI: 1.11∼1.44 (P < 0.05); FR = 1.23, 95%CI: 1.08∼1.46 (P < 0.05). APE1 Asp148Glu was found of no significant relationship with MN frequency. Haplotype analysis of XRCC1 demonstrated that the MN frequencies in subjects with CTAA/CTAA and CCAA/CTAA were significantly higher than that in those with TCGG/TCGG (FR = 1.19, 95%CI: 1.02∼1.32, P < 0.05; FR = 1.41, 95%CI: 1.02∼1.87, P < 0.05). Furthermore, association was found between accumulated exposure to VC and XRCC1 polymorphisms (-77C/T, Arg194Trp, Arg280His, and Arg399Gln) after adjustment for age, sex, drinking, and smoking.

CONCLUSIONVC can induce chromosomal damage even when the exposure level is lower than the national occupational health standard of China (PC-TWA: 10 mg/m(3)); the polymorphisms in XRCC1 and APE1 are associated with chromosomal damage induced by VC.

Adult ; DNA-(Apurinic or Apyrimidinic Site) Lyase ; genetics ; DNA-Binding Proteins ; genetics ; Female ; Haplotypes ; Humans ; Male ; Micronuclei, Chromosome-Defective ; Middle Aged ; Occupational Exposure ; adverse effects ; Polymorphism, Restriction Fragment Length ; Vinyl Chloride ; poisoning ; X-ray Repair Cross Complementing Protein 1 ; Young Adult