Abstract: Objective　To understand the situation of drug-resistant tuberculosis screening and epidemiological characteristics of multi-drug resistant tuberculosis (MDR-TB) and pre-extensively drug resistant tuberculosis (pre-XDR-TB) in Changsha, in order to provide a scientific basis for improving the quality of drug-resistant tuberculosis prevention and control in the city. Methods　Demographic information and drug susceptibility date of etiologically positive pulmonary tuberculosis patients in Changsha from 2018 to 2021 were collected, the successful rate of resistance screening, incidence and tendency in MDR-TB and pre-XDR-TB in patients included in this study were statistically analyzed accordingly. 　　Results From 2018 to 2021, the successful screening rates were 86.2%, 87.7%, 81.9% and 71.5% for MDR-TB and 82.2%, 84.8%, 76.9% and 68.2% for pre-XDR-TB, respectively. In each year, MDR-TB patients identified accounted for 7.6% (101/1 222), 6.5%(124/1 774), 6.6%(110/1 555) and 6.3%(99/1 478), and pre-XDR-TB patients identified accounted for 3.6%(46/1 219), 3.8%(69/1 766), 4.4%(69/1 495) and 4.6%(69/1 436), correspondingly. The incidence of MDR-TB showed a slowly downward trend, while the incidence of pre-MDR-TB showed a slowly upward trend, with neither decreasing nor increasing trends being statistically significant (（χ2=1.947，0.806，P>0.050). The incidence of MDR-TB in the retreatment failure population was 66.6% (2/3), and the others, failure initial treatment and recrudescence populations were 23.5% (19/81), 16.7% (2/12) and 15.2% (70/461), respectively. Similar to the incidence above, the incidence of pre-XDR-TB was 16.7% (2/12) among patients who failed in initial treatment, and 12.2% (9/74), 9.8% (43/439), and 4.5% (2/44) among the others, recrudescence and returned patients, respectively. The incidence rates of MDR-TB and pre-XDR-TB in different populations were significantly different (χ2=117.600，59.030，P<0.05). Conclusions There are still areas for improvement in tuberculosis drug resistance surveillance system in Changsha. On the premise of paying attention to patients in retreatment failure, other, initial treatment failure and relapse patients, high sensitivity molecular drug susceptibility testing, and scientifically efficient screening strategies must be explored.

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.
COVID-19 ; Cohort Studies ; Contact Tracing ; Humans ; Incidence ; Prospective Studies

ObjectiveTo study the pathological process and changes of metabolites in myocardial tissue of heart failure induced by transverse aortic constriction （TAC） in rats. MethodRats were treated with TAC operation and divided into TAC-30 d group and TAC-60 d group， and sham operation group at the same period was set up as control. Echocardiography and pathological staining of myocardial tissue were performed on rats in each group. Enzyme-linked immunosorbent assay was used to determine the expression of amino-terminal pro-brain natriuretic peptide （NT-proBNP） and adenosine triphosphate （ATP） in serum. Liquid chromatography-mass spectrometry was used to observe the changes of metabolites and related pathways in myocardial tissue， the mobile phase consisted of 25 mmol·L^-1 ammonium acetate and 25 mmol·L^-1 ammonia hydroxide in water （A） and acetonitrile （B） for gradient elution （0-0.5 min， 95%B； 0.5-7 min， 95%-65%B； 7-8 min， 65%-40%B； 8-9 min， 40%B； 9-9.1 min， 40%-95%B； 9.1-12 min， 95%B）， electrospray ionization was used under positive and negative ion detection modes， acquisition range was m/z 70-1 050. ResultCompared with the sham-30 d group， the left ventricular internal diameter at end-systole （LVIDs） in TAC-30 d group was significantly decreased （P<0.01）， and left ventricular ejection fraction （LVEF）， fraction shortening （FS）， left ventricular end-diastolic posterior wall thickness （LVPWd）， left vebtricular end-systolic posterior wall thickness （LVPWs） were significantly increased （P<0.01）， there were cardiomyocyte arrangement disorder， edema， collagen fibre hyperplasia， the content of NT-probNP was significantly increased， while the content of ATP was significantly decreased （P<0.01）， and 15 metabolites with abnormal expression were involved in pyrimidine metabolic pathway， pantothenic acid and coenzyme A biosynthesis pathway. Compared with the sham-60 d group， LVEF and FS in the TAC-60 d group were significantly decreased （P<0.01）， and left ventricular internal diameter at end-diastole （LVIDd）， LVIDs and LVPWd were increased （P<0.05， P<0.01）， the edema of myocardial cells increased obviously， myocardium fibers degenerated， coagulation necrosis appeared， and a large amount of collagen fibers were deposited， the expression of NT-proBNP increased and the expression of ATP decreased （P<0.01）， there were 21 metabolites with abnormal expression， involving pyrimidine metabolic pathway， and starch and sucrose metabolic pathway. ConclusionAt 30 d after TAC， there are myocardial hypertrophy， lipid metabolism disorder， pyrimidine metabolism disorder and energy imbalance. At 60 d after TAC， there are heart failure， aggravation of lipid metabolism disorder， excessive activation of glucose metabolism， and continuous disorder of pyrimidine metabolism.

Background: Human infections with zoonotic coronaviruses (CoVs), including severe acute respiratory syndrome (SARS)-CoV and Middle East respiratory syndrome (MERS)-CoV, have raised great public health concern globally. Here, we report a novel bat-origin CoV causing severe and fatal pneumonia in humans. Methods: We collected clinical data and bronchoalveolar lavage (BAL) specimens from five patients with severe pneumonia from Jin Yin-tan Hospital, Wuhan, Hubei province, China. Nucleic acids of the BAL were extracted and subjected to next-generation sequencing. Virus isolation was carried out, and maximum-likelihood phylogenetic trees were constructed. Results: Five patients hospitalized from December 18 to December 29, 2019 presented with fever, cough, and dyspnea accompanied by complications of acute respiratory distress syndrome. Chest radiography revealed diffuse opacities and consolidation. One of these patients died. Sequence results revealed the presence of a previously unknown β-CoV strain in all five patients, with 99.8–99.9% nucleotide identities among the isolates. These isolates showed 79.0% nucleotide identity with the sequence of SARS-CoV (GenBank NC_004718) and 51.8% identity with the sequence of MERS-CoV (GenBank NC_019843). The virus is phylogenetically closest to a bat SARS-like CoV (SL-ZC45, GenBank MG772933) with 87.6–87.7% nucleotide identity, but is in a separate clade. Moreover, these viruses have a single intact open reading frame gene 8, as a further indicator of bat-origin CoVs. However, the amino acid sequence of the tentative receptor-binding domain resembles that of SARS-CoV, indicating that these viruses might use the same receptor. Conclusion: A novel bat-borne CoV was identified that is associated with severe and fatal respiratory disease in humans.

BACKGROUND: Human infections with zoonotic coronaviruses (CoVs), including severe acute respiratory syndrome (SARS)-CoV and Middle East respiratory syndrome (MERS)-CoV, have raised great public health concern globally. Here, we report a novel bat-origin CoV causing severe and fatal pneumonia in humans. METHODS: We collected clinical data and bronchoalveolar lavage (BAL) specimens from five patients with severe pneumonia from Wuhan Jinyintan Hospital, Hubei province, China. Nucleic acids of the BAL were extracted and subjected to next-generation sequencing. Virus isolation was carried out, and maximum-likelihood phylogenetic trees were constructed. RESULTS: Five patients hospitalized from December 18 to December 29, 2019 presented with fever, cough, and dyspnea accompanied by complications of acute respiratory distress syndrome. Chest radiography revealed diffuse opacities and consolidation. One of these patients died. Sequence results revealed the presence of a previously unknown β-CoV strain in all five patients, with 99.8% to 99.9% nucleotide identities among the isolates. These isolates showed 79.0% nucleotide identity with the sequence of SARS-CoV (GenBank NC_004718) and 51.8% identity with the sequence of MERS-CoV (GenBank NC_019843). The virus is phylogenetically closest to a bat SARS-like CoV (SL-ZC45, GenBank MG772933) with 87.6% to 87.7% nucleotide identity, but is in a separate clade. Moreover, these viruses have a single intact open reading frame gene 8, as a further indicator of bat-origin CoVs. However, the amino acid sequence of the tentative receptor-binding domain resembles that of SARS-CoV, indicating that these viruses might use the same receptor. CONCLUSION A novel bat-borne CoV was identified that is associated with severe and fatal respiratory disease in humans.
Adult ; Aged ; Betacoronavirus ; genetics ; isolation & purification ; Coronavirus Infections ; diagnostic imaging ; therapy ; virology ; Female ; Humans ; Male ; Middle Aged ; Pandemics ; Pneumonia, Viral ; diagnostic imaging ; therapy ; virology ; Tomography, X-Ray ; Treatment Outcome

Objective　Vascular smooth muscle cells are the main cells in atherosclerosis. Reports are rarely seen on influenza virus infection on human aortic smooth muscle cells (HASMC) and its influence on the expressions of the related cytokines. This study was to investigate the impact of influenza A virus (IAV) and influenza B virus (IBV) infection on HASMCs and the expressions of cytokines. Methods　HASMCs were stimulated with IAV or IBV or not stimulated with virus (the control). The nucleoprotein of the influenza virus in the cells was detected by immunofluorescence assay, the proliferation of the cells determined with CCK8, and the level of influenza virus RNA in the supernatant measured by qPCR. The collected supernatant was used to infect Madin-Darby canine kidney (MDCK) cells and detect the influenza virus nucleoprotein. The expressions of the cytokines of the influenza virus after 24 hours of infection were determined by qPCR.　Results　At 3 and 4 days after infected with influenza virus, the proliferation of the HASMCs was significantly inhibited in the IAV and IBV groups as compared with the control (P<0.05). The expression of virus RNA in the supernatant of the IBV group at 3 days was 5.75 times as high as that at 2 days (P<0.05), dropped at 4 days but still higher than that at 2 days (P<0.01). Compared with the normal culture medium, the medium with virus growth fluid significantly elevated the RNA level of IAV (0.842±0.148 vs 15.182±1.932, P< 0.01) and IBV (0.962±0.033 vs 4.029±0.681, P<0.01). After infection, the expression of MCP-1 was remarkably up-regulated in the IAV and IBV groups (4.364±0.193 and 3.348±0.507) in comparison with that in the control group (1.001±0.001) (P<0.05), and so were the expressions of IL-6 and TNF-α (P<0.05).　Conclusion　Both IAV and IBV can infect HASMCs and increase the expressions of the cytokines MCP-1, IL-6 , and TNF-α.

BACKGROUND: Tendon-to-bone healing is a complex and slow process, which often hinders the therapeutic outcomes. To enhance the tendon-to-bone healing, increasing cell bioactivity on the contact surface is a new strategy. Hypoxia-inducible factor 1α (HIF-1α) can induce the formation of blood vessel and bone tissue via many ways.However,it is unclear whether HIF-1α can strengthen differentiation of human amniotic mesenchymal stem cells (hAMSCs) induced by Scleraxis, a specific marker of tendon, and can be used in tendon and bone repair. OBJECTIVE: To investigate the ability of HIF-1α in enhancing Scleraxis to modify hAMSCs aiming to promote tendon-to-bone healing and its molecular mechanism. METHODS: Passage 3 hAMSCs were infected with AdHIF-1α, AdScx, AdGFP and AdHIF-1α+AdScx. The expressions of related genes of tendon, cartilage and bone tissue were detected at 3 and 7 days after infection. RESULTS AND CONCLUSION: Under the inverted phase contrast microscopy, the passage 3 hAMSCs were in spindle shape and presented with vortex-like adherent growth. Under the transmission electron microscopy, hAMSCs were in oval shape and had clear structure, with abundant endoplasmic reticulum and mitochondria. Fluorescence photographs were taken at 24 hours after adenovirus infection, showing about 50% red fluorescence expression in the AdHIF-1α group, while about 70% green fluorescence expression in the AdScx and AdGFP groups. Real time-PCR results showed that at 3 and 7 days after infection, the mRNA expressions of collagen type I, Fibronectin, RUNX2, VEGF and ALP in the AdHIF-1α+AdScx group, AdHIF-1α group and AdScx group were higher than those in the AdGFP group (P < 0.05); the mRNA expressions of collagen type I, Fibronectin, RUNX2, VEGF and ALP in the AdHIF-1α+AdScx group were significantly higher than those in the AdScx group (P < 0.05). Fluorescence immunohistochemistry results showed that the expression of collagen type I in the AdHIF-1α+AdScx group at 7 days after infection was higher than that at 3 days after infection. To conclude, HIF-1α can enhance the ability of Scleraxis to modify hAMSCs to promote tendon-to-bone healing by upregulating the expressions of molecular markers of tenocytes, chondrocytes and osteocytes.

BACKGROUND: Human amniotic mesenchymal stem cells (hAMSCs) are adult stem cells with multipotential differentiation, which can be induced to differentiate into bone, cartilage and other connective tissues. Meanwhile, as a highly specific marker of tenocytes, Scleraxis is involved in aggregation and differentiation of tendon progenitor cells as well as the formation of tendon extracellular matrix. OBJECTIVE: To investigate whether hAMSCs have the ability of differentiation into tenocytes by ectopic expression of Scleraxis. METHODS: Agreed by puerpera, the amniotic membrane from the full-term placenta was separated, and hAMSCs were isolated by a two-step enzyme digestion, observed under inverted phase contrast microscope, and identified by flow cytometry. Passage 3 cells were induced via plasmid-mediated Scleraxis overexpression in overexpression group. Untransfected cells cultured in normal medium served as blank control group, and those with empty plasmid transfection were defined as empty plasmid group. Cell proliferation was tested in each group using cell counting kit-8 within 7 days of culture. Real-time quantitative PCR and western blot were used to assess the tenogenic differentiation of hAMSCs in each group at 3 and 7 days of culture. RESULTS AND CONCLUSION: Findings from the cell counting kit-8 indicated that the cell viability had no significant differences among the groups within 7 days of culture (P > 0.05). Western blot results showed the protein expression of Scleraxis in the treatment group was significantly higher than that in the other two groups (P < 0.05). Real-time PCR results showed, at 3 days of culture, the expression of collagen type I, collagen type III, Fibronectin and Tenascin-C in the overexpression group was significantly higher than that in the empty plasmid group (P < 0.05), but the expression of Tenomodulin had no difference (P > 0.05); at 7 days of culture, the expressions of collagen type I, collagen type III, Fibronectin, Tenascin-C and Tenomodulin in the overexpression group were significantly higher than those in the empty plasmid group (P < 0.05). In summary, hAMSCs can be differentiated into tenocytes by ectopic expression of Scleraxis.

Objective To detect the SNR and geometric accuracy of MRI based on American College of Radiology (ACR)standards.Methods The SNR and geometric accuracy of Siemens Skyra 3.0T,Siemens Trio 3.0T and GE Excite HD 1.5T MRI were measured with ACR phantom,and the detection results were calculated according to the standards.Results The SNR values of Siemens Skyra 3.0T,Siemens Trio 3.0T and GE Excite HD 1.5T MRI were 589.98,438.50 and 277.12 respectively.Siemens Skyra 3.0T MRI had the values of geometric accuracy being-1.93％ at X direction,-3.20％ at Y direction and 0.68％ at Z direction,Siemens Trio 3.0T MRI had the value of geometric accuracy being-0.87％ at X direction,-2.33％ at Y direction and 1.49％ at Z direction,GE Excite HD 1.5T MRI had the values of geometric accuracy being 0.20％ at X direction,-1.53％ at Y direction and 1.69％ at Z direction.Conclusion The detection of the SNR and geometric accuracy of MRI can effectively guarantee the image quality.

Objective To evaluate the safety and efficacy of cefaze-done injection ( CZD) compared with cefazolin injection ( CZL) in the treatment of acute bacterial respiratory infections.Methods Eligible subjects were divided randomly to receive 2.0 g cefazedone injection or cefazolin injection twice a day for 7 to 14 days.Efficacy and safety evaluation were done in accordance with the clinical trial protocol.Results Two hundred and sixty patients in 11 hospitals were en-rolled, 126 in CZD group( trial) and 134 in CZL group( control).There were no statistical differences in basic conditions between two groups( P >0.05 ).Cure rates of CZD group and CZL group were 95.5% and 94.9% in PPS ( P>0.05 ).Bacteria clearance rates of CZD group and CZL group were100% and 91.7% in BPPS and the total cure rates of CZD group and CZL group were 94.4% and 91.7% in BPPS, respectively ( P>0.05).Ten out off 126 patients in CZD group and 14 out off 134 in CZL group developed adverse events( AE ).Six and eleven events in CZD group and CZL group
were evaluated to be related with study drugs.One case in CZL group developed severe AE , which was considered not related with study drug.Conclusion Cefazedone injection is safe and effective in the treatment of respiratory infections.