ObjectiveTo evaluate the role of Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway in attenuation of myocardial ischemia-reperfusion (I/R) injury by tetramethylpyrazine in rats.MethodsSixty-four healthy male Wistar rats weighing 250-300 g were randomly divided into 4 groups( n ＝ 16 each):sham operation group (group S),myocardial I/R group(group I/R),teramethylpyrazine group (group T) and AG,490( a JAK2 inhibitor) group (group AG).Myocardial I/R was induced by 30 min occlusion of left anterior desecending coronary artery (LAD) followed by 120 min reperfusion in groups I/R,T and A.In groups T and A teramethylpyrazine 20 mg/kg was injected iv 20 min before LAD occlusion.In group A AG490 3 tμg/g was injected iv at 5 min before reperfusion.Blood samples were then taken from inferior vena cava at 120 min of reperfusion for measurement of serum creatine phosphokinase (CK) and lactose dehydrogenase (LDH) activities.Myocardial infarct size was then measured and myocardial tissue was obtained for microscopic examination.ResultsSerum CK and LDH activities were significantly higher in group I/R than in group S.Pretreatment with tetramethylpyrazine significantly decreased myocardial infarct size and I/R-induced increase in serum CK and LDH activities and histologic damage.The protective effect of tetramethylpyrazine against myocardial 1/R injury was attenuated by postconditioning with AG490.ConclusionJAK2/STAT3 signaling pathway is involved in attenuation of myocardial I/R injury by tetramethyl pyrazine in rats.

Objective:To evaluate the accuracy of variation of carotid artery hemodynamic parameters combined with passive leg raising (PLR) test in predicting supine hypotension syndrome (SHS) after spinal anesthesia in the patients undergoing cesarean section.Methods:Sixty-four parturients who were at full term with a singleton fetus, at 37-42 weeks of gestation, aged 18-40 yr, with body mass index of 18-30 kg/m 2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, undergoing elective cesarean section, were enrolled in this study.The variation of carotid artery diameter (ΔD), variation of velocity time integral (ΔVTI), and variation of carotid blood flow (ΔCBF) before and after PLR were measured using ultrasound.Patients were divided into SHS group and non-SHS group (NSHS group) according to whether SHS after spinal anesthesia occurred.Pearson correlation was used to analyze the correlation between ΔD, ΔVTI, ΔCBF and systolic blood pressure (SBP) after spinal anesthesia.The receiver operating characteristic curve was used to assess the accuracy of ΔD, ΔVTI and ΔCBF in predicting SHS. Results:ΔVTI was negatively correlated with SBP after spinal anesthesia ( r=-0.539, P<0.01), ΔCBF was negatively correlated with SBP after spinal anesthesia ( r=-0.475, P<0.05), and ΔD had no correlation with SBP after spinal anesthesia in group SHS ( P>0.05). The critical values of ΔCBF, ΔVTI, and ΔD combined with PLR in predicting SHS after spinal anesthesia were 15.5%, 10.1%, and 6.0%, respectively, the sensitivity was 92.9%, 57.1%, and 96.4%, respectively, and the specificity was 53.1%, 81.2%, and 75.0%, respectively, and the areas under the curve were 0.873, 0.681 and 0.846, respectively. Conclusion:The ultrasound-measured ΔCBF and ΔD of carotid artery combined with PLR can be used as a reliable method to predict SHS after spinal anesthesia in the patients undergoing cesarean section, and the ΔCBF combined with PLR has a higher accuracy.

Objective:To compare the differences between suspension and adherent cells of MDCK cell line in the isolation of influenza virus, and to explore the application prospects of MDCK cell suspension.Methods:Determination of viable cell density and cell specific growth rate were recorded by cell count. The WHO recommended vaccine strains were used for virus infection experiments. After five passages, hemagglutination titers were detected, while the sequencing analysis of their HA and NA genes revealed the mutation frequency.Results:The 24-hour and 48-hour viable cell density of the cell suspension was more stable than that of adherent cells. The cell suspension achieved an HA titer of 1∶256 or higher in the third generation, while adherent cells had no titer. In the fourth and fifth generations, one amino acid site mutation was found in the HA gene of H3N2 and BV subtypes of influenza virus cultured in the cell suspension, while no gene mutation was found in adherent cells in two passages. There were no mutations in the whole NA gene.Conclusions:Suspension of MDCK cells have more stable growth and higher efficiency in virus isolation than adherent cells, meanwhile there was a low rate of virus mutation during continuous passage. This study demonstrated the feasibility of this suspension of MDCK cells for influenza vaccine production based on cell culture technology.

Objective:To analyze the genetic and molecular characteristics of H9N2 subtype avian influenza viruses from external environment and humans in Anhui Province from 2013 to 2022.Methods:Environmental samples and human samples were collected from Anhui influenza surveillance network laboratory. Sixty-three strains of virus were isolated in chicken embryos. RT-PCR was used to amplify the virus and whole genome sequencing was performed. To construct gene evolutionary tree and analyze its genetic characteristics and potential glycosylation sites.Results:The hemagglutinin (HA) gene belongs to the 9.2.4.5 clade, and the protein cleavage sites are mostly " PSRSSR\GL". The neuraminidase (NA) gene, basic protein-1(PB1) gene, acidic protein (PA) gene, non-structural protein (NS) gene and nucleoprotein (NP) gene belong to the F/98 clade, the matrix protein (MP) gene belongs to the G1/97 clade, and the basic protein-2 (PB2) gene belongs to the ST/7488 clade. Mutations of T155N, R164Q, H183N, T189D/V, A190V/T and Q226L occurred in HA protein, deletion of NA protein occurred at 62-64 sites, and mutations of T271A, I292V/M and E627V/L occurred in PB2 protein. At the same time, mutations of K356R and S409N occurred in the PA protein.Conclusions:The H9N2 subtype avian influenza viruses collected from external environment and human sources in Anhui province from 2013 to 2022 belong to the same evolutionary branch, and amino acid site mutations suggest that the virus shows a tendency to gradually adapt to the mammalian host environment. Therefore, further studies on the adaptive evolution of the virus and related monitoring work are needed.

Objective:Analysis of the characteristics of influenza epidemic in Anhui Province and quantification of the impact of different factors on influenza occurrence, providing scientific basis for better influenza prevention and control.Methods:Descriptive analysis and factor analysis were conducted on influenza-like illness (ILI) cases and RT-PCR results in Anhui Province from 2013 to 2021 using data from China's Influenza Monitoring Information System.Results:The percentage of influenza-like illness (ILI%) of sentinel hospitals in Anhui Province from April 1, 2013 to March 31, 2021 was 3.80% (1 209 142/31 779 987), showing an overall increasing trend, with a relatively high proportion in 2017-2018 at 4.30% (191 148/4 448 211). The proportion of ILI cases in infants and young children aged 0-4 years was a relatively high at 54.14% (654 676/1 209 142), and the highest ILI% was observed in Fuyang City, Anhui Province (6.25%, 236 863/3 788 863). Laboratory monitoring results showed that the positive rate of ILI cases in sentinel hospitals in 8 influenza monitoring years was 16.38% (34 868/212 912), showing an increasing trend year by year, with a relatively proportion in 2017-2018 at 26.19% (6 936/26 488). The detection rate of school-age children aged 5-14 years was a relativelyhigh at 28.81% (13 869/48 144), and the positive rate was a relatively high in Wuhu City among the 16 cities, reaching 22.01% (2 693/122 237). Influenza activity showed a single peak in winter-spring and alternating double peaks in winter-spring and summer, with different subtypes alternating, and A (H3N2) was the dominant subtype in summer. The results of a multiple logistic regression model showed that the positive rate was higher in 2017-2018, among children aged 5-14 years, in winter, and in southern Anhui.Conclusions:Influenza epidemic in Anhui Province has a clear seasonal pattern, and the ILI% and detection rate have shown an upward trend from 2013 to 2021. Therefore, it is suggested to ensure vaccine supply before the winter-spring influenza season arrives, and to strengthen vaccine uptake and health education to avoid the risk of infection during the peak period of influenza.

Objective To evaluate the effect of living skin equivalents (LSE) constructed of mixed autologous and allogeneic skin cells and human amnion which served as a matrix on repairing scar contracture of the hand in a patient with recessive dystrophic epidermolysis bullosa (RDEB).Methods Skin tissues were obtained from a patient with RDEB and her mother,and epidermal keratinocytes and dermal fibroblasts were isolated from these tissues and cultured in vitro separately.Human amnion was obtained from the placenta of an unrelated healthy parturient undergoing cesarean delivery,and served as a matrix of the LSE.The autologous and allogeneic fibroblasts were mixed and seeded on the stromal side of the amnion,and then the autologous and allogeneic keratinocytes were mixed and seeded on the epithelial side of the amnion,so as to construct the human amnion-LSE (AM-LSE).Histological examination was performed to observe the structure of the skin tissues obtained from the patient and her mother,and immunofluorescence staining was conducted to detect the expression of type Ⅶ collagen in the skin tissues of the patient and her mother and in the AM-LSE.The AM-LSE was grafted on the skin defects of the patient after release of scar contracture of the hand.After grafting,the survival status of the AM-LSE graft and repairing effect on the wounds were evaluated.Results The constructed AM-LSE consisted of dermis,multilayered and fully differentiated epidermis and well-developed basement membrane.Immunofluorescence examination revealed that type Ⅶ collagen was linearly distributed along the basement membrane.Half a year after grafting,the AM-LSE survived well,and no obvious rejection reaction was observed.No blisters or ulcers occurred at the recipient sites,and the scar contracture was mild.The grafted area showed normal skin color with soft texture.The patient could grab and hold things,which had met self-care requirements of daily living.Conclusions The AM-LSE constructed of mixed autologous and allogeneic skin cells have good histological structures,and can be grafted on the wounds after resection of the scars in a RDEB patient.After grafting,no obvious rejection reaction was observed,and the skin was not liable to develop blisters,ulcers or scar contracture due to friction.

Objective:To evaluate the efficacy and safety of azacitidine combined with HAG regimen in the treatment of newly diagnosed elderly acute myeloid leukemia (AML) patients ineligible for intensive chemotherapy.Methods:Eighteen newly diagnosed elderly AML patients ineligible for intensive chemotherapy from July 2019 to September 2021 in the Second People's Hospital of Shenzhen were prospectively enrolled in this study. They were non-randomly divided into azacitidine combined with HAG regimen (AZA-HAG) group (9 cases) and decitabine combined with HAG regimen (DEC-HAG) group (9 cases). The primary endpoint of the study was overall response [complete remission (CR)+partial remission], and the secondary endpoints included CR + complete remission with incomplete count recovery (CRi), overall survival (OS) and drug safety. Kaplan-Meier method was used to analyze the OS.Results:The median age of 18 patients was 67 years old (60-77 years old) , and 8 of them were in high-risk group. After one course of treatment, the overall response and CR+CRi were observed in 7 of 9 patients in AZA-HAG group, and they were observed in 8 of 9 patients in DEC-HAG group, and there was no significant difference between the two groups (both P = 1.000). The median duration of CR+CRi was 7 months in both groups, and the median OS time was 12 months in both groups; there was no significant difference in OS between the two groups ( χ2 = 0.02, P = 0.895). In AZA-HAG group, 1 patient with TP53 mutation and 1 patient with ASXL1+RUNX1 mutation acquired CR, and 1 patient with NPM1 wild-type combined with FLT3-ITD and ASXL1 mutation did not respond. There was no significant difference in the incidence of grade 3-4 hematological adverse reactions between the two groups (all P < 0.05). Conclusions:Azacitidine combined with low-dose HAG regimen in the treatment of newly diagnosed elderly AML patients ineligible for intensive chemotherapy has satisfactory efficacy and long-term survival, and the adverse reactions can be tolerated.