BACKGROUND:Bone marrow mesenchymal stem cells(BMSCs)can release a large number of exosomes(Exos).The effect of Exos derived from BMSCs on hepatocyte apoptosis and the specific mechanism has not been fully clarified. OBJECTIVE:To explore the effect of miR-21-5p carried by Exos derived from BMSCs on apoptosis of rat liver cells and its mechanism. METHODS:Rat BMSCs were isolated and miR-21-5p NC or miR-21-5p inhibitor was transfected into BMSCs.The Exos were extracted by ultracentrifugation and named(BMSCs+miR-21-5p NC)-Exos and(BMSCs+miR-21-5p inhibitor)-Exos.BMSCs-derived Exos were co-cultured with rat hepatocytes to observe the effect of inhibiting miR-21-5p expression on the apoptosis of rat hepatocytes.The targeting relationship between miR-21-5p and PIK3R1 was verified by double luciferase reporter gene detection.TUNEL was used to detect the effect of miR-21-5p directly targeting PIK3R1 in Exos to activate the PI3K/AKT signaling pathway on hepatocyte apoptosis in BRL rats. RESULTS AND CONCLUSION:(1)The double luciferase reporting system confirmed that when PI3KR1 wild type vector and miR-21-5p mimics co-transfected 293T cells,the luciferase activity decreased significantly compared with the PI3KR1 mutant vector co-transfected group,indicating that miR-21-5p could target PIK3R1.(2)TUNEL test results showed that compared with(BMSCs+miR-21-5p NC)-Exos group,(BMSCs+miR-21-5p inhibitor)-Exos treatment significantly increased the apoptosis rate.Compared with the(BMSCs+miR-21-5p NC)-Exos group,after the addition of AKT inhibitor LY294002,the apoptosis rate was significantly increased.(3)The results indicate that Exos may inhibit the apoptosis of BRL rat hepatocytes through miR-21-5p,in which miR-21-5p directly targets PIK3R1 to activate PI3K/AKT signaling pathway.

Objective:To analyze the etiological and epidemiological characteristics of hand, foot and mouth disease (HFMD) in Xi′an from 2019 to 2021, so as to provide evidence for the prevention and control of HFMD.Methods:Stool specimens and anal swabs were collected from patients with HFMD. Enteroviruses (EVs) including enterovirus 71 (EV71), coxsackievirus A16 (CVA16), CVA6 and CVA10 were detected by RT-PCR. Excel 2007 and SPSS18.0 software were used for data collection and statistical analysis, respectively. The epidemiological data of HFMD cases were analyzed by descriptive epidemiology method. The VP1 gene sequence of the representative strain of each CVA6 genotype was downloaded. Phylogenetic trees were constructed using MEGA X software and the genetic characteristics were analyzed.Results:A total of 1 531 HFMD cases were involved and 1 365 were positive for EVs with a positive rate of 89.16%. The detection rates of EV71, CVA16, CVA6, CVA10 and other EVs were 1.31% (20/1 531), 32.46% (497/1 531), 38.47% (589/1 531), 5.09% (78/1 531) and 11.23% (172/1 531), respectively. There were significant differences in the pathogen composition in HFMD cases of different clinical types (χ 2=46.14, P<0.01) and occupations (χ 2=34.65, P<0.01) as well as in different years (χ 2=462.86, P<0.01). The average age was greater in patients with CVA16 infection than in those with CVA6 or CVA10 infection ( F=6.00, P<0.01). In 2019, the HFMD cases were mainly caused by CVA16, while in 2020 and 2021, the main pathogen was CVA6. Enterovirus-positive cases showed a bimodal distribution with the main peak from May to July and the secondary peak from September to November. CVA16 was the predominant pathogen in spring and summer, and CVA6 was the predominant pathogen in autumn. CVA6 was the dominant pathogen in eight districts and counties of Xi′an; CVA16 was the dominant pathogen in six districts and counties; CVA6 and CVA16 co-circulated in one district. The CVA6 isolates belonged to two evolutionary branches of D3a subtype. Conclusions:CVA6 and CVA16 were the prevalent pathogens of HFMD and CVA6 subtype D3a circulated in Xi′an from 2019 to 2021. The pathogen composition of HFMD cases showed obvious differences in population, time and regional distribution.

Objective:To characterize the epidemiology of hand, foot and mouth disease (HFMD) cases caused by coxsackievirus group A type 6 (CV-A6) in Xi’an from 2016 to 2020 and provide evidence for the prevention and control of HFMD.Methods:The enterovirus (EV) types were identified using real-time RT-PCR. The data of HFMD cases were collected from the National Notifiable Infectious Diseases Reporting System of China Center for Disease Control and Prevention. Descriptive epidemiological method were used to analyze the distributions and the data were statistically analyzed with Excel 2007 and SPSS 18.0.Results:In the 4 034 HFMD cases, 17.85% had enterovirus group A type 71 (EV-A71) infections, 23.92% had coxsackievirus group A type 16 (CV-A16) infections, and 47.79% had other EV infections. 2 571 HFMD cases were randomly selected, including 1 268 other EV positive cases. The detection rate of CV-A6 in HFMD cases was 34.73% (893/2 571), and the constituent ratio of CV-A6 in other EV positive cases was 70.43% (893/1 268). The cases mainly occurred in children aged≤5 years (95.18%), more boys were affected than girls (1.47∶1). HFMD caused by CV-A6 was concentrated in April to June. Compared with EV-A71 and CV-A16, the clinical classification had significant difference in CV-A6 group ( χ2=139.55, P<0.001), but the ratio of sex and age-group had no significant difference ( F=2.74, P=0.065; χ2=2.43, P=0.297). Conclusions:The predominant pathogen of HFMD in Xi’an from 2016 to 2020 were other EV, among which CV-A6 accounted for the highest proportion in other EV positive cases. It is necessary to strengthen the prevention and control of HFMD caused by CV-A6 and carry out the surveillance for various pathogens of HFMD.

Objective:To investigate the sero-epidemiological characteristics of the hepatitis D virus (HDV) infection among hepatitis B virus (HBV)-infected patients in Xinjiang region.Methods:A single-center cross-sectional analysis method was used to select 264 cases of hepatitis B virus infection who were hospitalized in the Center for Infectious Diseases and Liver Diseases of the First Affiliated Hospital of Xinjiang Medical University from August 2021 to January 2022. All patients were tested for HDV Ag, HDV IgM, HDV IgG, and HDV RNA. The infection status of hepatitis D virus was analyzed by grouping according to their clinical type, HBV viral load, and HBsAg level. A paired t-test was used for data with measurement data conforming to normal distribution. A paired rank sum test was used for data that did not conform to normal distribution before and after treatment.Results:A total of 36 cases (13.64%) and 26 cases (9.85%) were positive for HDV serological markers and HDV RNA. According to clinical type grouping, the positive rates of HDV serum markers in patients with chronic hepatitis B, hepatitis B-related cirrhosis, liver cancer, and liver failure were 13.46%, 12.43%, and 20.83%, respectively, and there was no statistically significant difference among the three groups ( χ2=0.86, P=0.649). The positive rates of HDV RNA were 11.54%, 8.11%, and 20.83%, respectively, and there was no statistically significant difference among the three groups ( χ2=4.015, P=0.134). According to HBV viral load grouping, the positive rates of HDV serum markers among patients with viral loads <20, 20-2 000, and >2 000 IU/ml were 17.15%, 7.81%, and 6.67%, respectively, and the difference was not statistically significant among the three groups ( χ2=4.846, P=0.089). The positive rates of HDV RNA were 9.47%, 10.94%, and 10%, respectively, and the difference was not statistically significant among the three groups ( χ2=0.113, P=0.945). According to HBsAg level grouping, the positive rates of HDV serum markers in HBsAg<0.05, 0.05~250, and >250 IU/ml were 14.29%, 16.67%, and 10.85%, respectively, and there was no statistically significance between the three groups ( χ2=1.745, P=0.418). The positive rates of HDV RNA were 4.76%, 8.77%, and 11.63%, respectively, and there was no statistically significant difference among the three groups ( χ2=1.221, P=0.543). Clinical outcome, disease course, HBV DNA, serological markers of viral hepatitis, routine blood test, biochemical indicators, coagulation function, and other laboratory indicators were compared between HDV serum marker and/or nucleic acid positive and negative patients, and there was no statistically significant difference ( P>0.05). Conclusion:The positive rate of HDV serological markers and HDV RNA is 13.64% and 9.85%, respectively, at a single center in the Xinjiang region, and there is still a high HDV infection rate among the HBV-infected patients with low levels of viral load and HBsAg.

Objective:To understand the composition of the pathogen spectrum of hand, foot and mouth disease(HFMD)in Xi′an from 2017 to 2018 and the genetic characteristics of enterovirus 71 (EV-A71).Methods:From 2017 to 2018, 1735 anal swab specimens from HFMD patients in Xi′an HFMD sentinel hospitals were collected, and qPCR was used to identify EV-A71, Coxsackie virus A 16 (CV-A16) and other enteroviruses. Selected EV-A71 strains were isolated, and VP1 region was amplified and sequenced, then phylogenetic tree and homologic comparison were conducted.Results:A total of 1 565 positive samples of enterovirus RNA were detected, positive rate was 90.20%(1565/1735), of which 24.79%(388/1 565)were positive for EV-A71, 21.85%(342/1 565)were positive for CV-A16, and 53.36%(835/1 565)were positive for other enterovirus. The main pathogen in 2017 was EV-A71(45.08%) and in 2018 was non-EV-A71-non-CV-A16 enteroviruses (73.38%), and the difference in pathogen composition was statistically significant ( χ2=370.57, P<0.001). HFMD caused by EV-A71 was concentrated in April to July, accounting for 73.97% (287/388) of the total cases. The homology analysis of the EV-A71 VP1 region showed that the 20 isolated EV-A71 strains belonged to the C4a subtype, with nucleotide and amino acid homology of 94.4%-96.1% and 99.4%-100% respectively, which were separated from those of the previous Xi′an City, the homology of EV-A71 obtained was above 91.5%. The result of the genetic evolution analysis of the EV-A71 VP1 region showed that the EV-A71 strain and the representative strain of the C4a subtype in Xi′an from 2008 to 2018 were in the same branch, forming multiple epidemic clusters, the variation degree of VP1 region increased with time. Conclusions:Non-EV-A71-non-CV-A16 enteroviruses were the main pathogens of HFMD in Xi′an from 2017 to 2018, and C4a subtype EV-A71 is still circulating in Xi′an. The monitoring of the pathogen spectrum and molecular epidemiology of HFMD should be strengthened to provide work for further effective prevention and treatment of HFMD.

Objective:To explore the positive rates of 2019-nCoV nucleic acid at different time of courses of COVID-19.Methods:Patients with confirmed COVID-19 were enrolled in this study. Nasal and throat swabs were collected from different courses of disease. Real-time RT-PCR was used to detect 2019-nCoV nucleic acid.Results:From January 23 to February 20, 2020, a total of 120 confirmed cases of COVID-19 were reported in Xi’an, and 85 cases(70.83%) were positive in first detection. The COVID-19 cases included consistently nucleic acid positive and intermittently nucleic acid positive patients. 2019-nCoV nucleic acid could be detected in incubation period, and the longest observed duration of nucleic acid positive in this study was 26 days. The positive rate of 2019-nCoV nucleic acid was up to 84.21% on the 6th day, and the positive rate decreased as time passed during the course of COVID-19. Three patients (2.86%) were tested positive for 2019-nCoV nucleic acid again in nasal and throat swabs after discharge.Conclusions:The positive rate of 2019-nCoV nucleic acid was higher in the early stage of disease. 2019-nCoV nucleic acid can be detected in incubation period, and virus shedding may last for a long period.

Objective:To analyze the clinical characteristics of HBV-related liver cirrhotic patients with low viral load.Methods:A retrospective analysis on 481 inpatients with HBV-related cirrhosis with low viral load [HBV DNA≤2 000 IU/ml (10 4 copies/ml)] general condition, virological indicators, liver function-related indicators, complications, and incidence of complications were analyzed. The t-test was used to compare the average measurement data, and the χ2 test was used to compare the count data. Results:481 cases were mainly male (male/female: 324/157), aged 20-83 (53.31 ± 11.67) years old. Han nationality accounted for 71.518%. 386 cases were HBsAg positive. 391 cases were HBeAg positive, and 140 cases were HBV DNA positive. The average value of bilirubin, albumin, alanine aminotransferase, aspartate aminotransferase, platelets, and prothrombin were 50.59 ± 91.25 (μmol/L), 33.68 ± 7.5 (g/L), and 60.66 ± 106.95(U/L), 63.37 ± 86.19(U/L), 106.65 ± 83.22(×10 9/L), 68.82% ± 25.33%, respectively. CTP class A/B/C had 220/150/111 cases. The average values of CTP, MELD, APRI and FIB-4 were 7.61 ± 2.58, 10.98 ± 5.79, 2.34 ± 3.56, 6.91 ± 8.04, respectively. The overall incidence of complications in HBV-related cirrhotic patients with low viral load, HBV DNA negative, HBV DNA positive, HBsAg negative, and HBsAg positive were 80.0%, 82.7%, 73.6%, 85.3%, and 78.8%, respectively. Among them, 283 cases (58.84%), 197 cases (55.77%), 86 cases (61.43%), 52 cases (54.74%) and 231 cases (59.84%) were of hypersplenism, and 267 cases (55.51%), 197 cases (55.77%), 70 cases (50.00%), 56 cases (58.95%), and 211 cases (54.66%) were of esophagogastric varices. There were 59 cases (12.27%), 48 cases (14.08%), 11 cases (7.86%), 12 cases (12.63%), and 47 cases (12.18%) of rupture of esophageal and gastric varices, respectively. 202 cases (42.00%), 147 cases (43.11%), 55 cases (39.29%), 42 cases (44.21%), and 160 cases (41.45%) were of ascites, respectively. 17 cases (3.53%), 12 cases (3.52%), 5 cases (3.5%), 2 cases (2.11%), 15 (3.89%) cases were of hepatic encephalopathy, respectively. There were 6 cases (1.25%), 3 cases (0.88%), 3 cases (2.14%), 0 cases (0%), 6 cases (1.55%) of liver cancer. 29 cases (6.03%), 21 cases (6.16%), 8 cases (5.71%), 9 cases (9.47%) and 20 cases (5.18%) were of portal vein thrombosis. Compared with the overall incidence of complications, 341 HBV DNA-negative patients and 95 HBsAg-negative patients still had higher incidence of complications. The patients were grouped by age, and in < 40 years old, 40-50 years old, and > 50 years old, the overall complications were 80.8% in 42 cases, 76.8% in 116 cases and 81.7% in 227 cases, and the difference was not statistically significant. Conclusion:HBV infection patients with low viral load, and those whose HBsAg has disappeared, are still at risk of developing liver cirrhosis and even serious complications, and whether such population need antiviral therapy and benefit from it deserves further research.

Objective To understand the distribution of novel coronaviruses in the external environment of confirmed COVID-19 cases. Methods Environmental surface swab specimens such as bed rails, doorknob, closestool, hand washing sink, table, locker,ward pager, mobile phone, cup, clothes, were collected from the sentinel hospital of COVID-19, and samples were collected for the nucleic acid detection by RT-PCR. Results A total of 150 environmental samples were collected from 30 confirmed COVID-19 cases, 6 samples were determined to be novel coronaviruses postive (positive rate 4.00%). The total 14 mobile phone showed 3 novel coronaviruses positive.Among the 30 confirmed COVID-19 cases, 6 cases (positive rate 20.00%)were found novel coronaviruses in the external environment. Conclusions Novel coronaviruses exists in external environment of confirmed COVID-19 cases, which indicates the potential risk of COVID-19 infection.

Objective:To investigate the positive rates of 2019-nCoV nucleic acid in different specimens from confirmed COVID-19 cases during hospitalization and after discharge.Methods:Patients with confirmed COVID-19 were enrolled from designated hospitals. Nasal swabs, throat swabs, and specimens of stool, urine and blood were collected during hospitalization. After the patients were discharged, nasal swabs, throat swabs and stool specimens were collected during follow-up. Real-time RT-PCR was used to detect 2019-nCoV nucleic acid.Results:This study involved 25 confirmed COVID-19 cases. During hospitalization, all patients tested positive in both nasal and throat swab 2019-nCoV nucleic acid tests, and nine of them (36.00%) were positive in stool specimen test. Urine and blood specimen test results were all negative. Nasal swabs, throat swabs and stool specimens were collected from each patient 7 d and 14 d after discharge. Two patients (8.00%) tested positive for 2019-nCoV nucleic acid again in nasal and throat swab tests on 7 d, while all stool specimen tests were negative. No 2019-nCoV nucleic acid was detected in nasal swabs, throat swabs or stool samples on 14 d.Conclusions:2019-nCoV nucleic acid was detected in stool samples of confirmed COVID-19 cases during hospitalization. Nasal and throat swab nucleic acid tests turned positive again in some patients after discharge.

Objective: To analyze the epidemiological characteristics and etiologic agent of herpangina in Xi’an in 2016. Methods: Herpangina epidemiological data and random stool samples were collected from two sentinel hospitals. The data were statistically analyzed with Excel and SPSS 18.0 and samples were detected and enteroviruses were genotyped using real-time PCR and RT-snPCR. Results: Totally 421 cases were reported and the male-to-female ratio was 1.54∶1, age ranged from 3 month to 13 years, and 90.50% were under three years of age. Herpangina showed semiannual peaks in April to October, of which the highest was in June (23.75%, 100/421). Lab result showed that 71.05% were EV positive out of 152 samples, and further genotyping indicated 60 were non-typable, and other 48 comprised of eight serotypes of EV including EV-A71, CV-A4, CV-A5, CV-A6(6.48%), CV-A10(23.15%), CV-A12, CV-A16 and CV-B3. Conclusions Male children under 3 years of age were the main population and herpangina cases were most frequently reported in June in Xi’an in 2016. CV-A6 and CV-A10 were more frequently detected in the typable ones.