Objective To prepare virus-like particles (VLPs) for yellow fever virus (YFV) using the pACYCDuet-1 single-plasmid dual expression system. Methods Gene fragments including NS1, NS5, and 5' untranslated region (UTR) and 3' UTR fragment of YFV were cloned into the expression plasmid pACYCDuet-1-MS2-TMpac (carrying MS2 coat protein gene) and transformed into E. coli BL21(DE3) for expression. VLPs were observed by TEM. After DNase I/RNase A digestion, RNA was extracted and transcribed into cDNA, which was subjected to fluorescence quantitative PCR detection. Results According to SN/T 3560-2013, double digestion and colony PCR of pACYCDuet-1-MS2-TMpac-YFV both produced expected bands. SDS-PAGE showed a target band at 25-35 kDa. RT-PCR amplified VLPs after enzyme digestion, and TEM revealed VLPs with clear edges and translucent interiors. Thus, the plasmid was successfully constructed, and the phage coat protein packaged YFV genes with nuclease resistance. Conclusion VLPs containing specific gene fragments of yellow fever virus have been successfully prepared. These nuclease-resistant VLPs can serve as safe and stable quality control materials to ensure the reliability of laboratory detection for YFV.

Objective To observe the efficacy of positive pressure oxygen therapy combined with drugs to improve pulmonary circulation in the treatment of severe viral pneumonia in high-altitude areas.Methods A two-way cohort study was conducted.Patients with severe viral pneumonia and those with common viral pneumonia complicated with underlying heart and lung diseases admitted to department of intensive care unit of Xizang Autonomous Region People's Hospital were selected as the research subjects.Patients who received conventional treatment in the early stage were assigned to the control group,while those who received conventional treatment plus active positive pressure oxygen therapy combined with drugs to improve pulmonary circulation in the later stage were assigned to the study group.The treatment effective rates of the two groups were observed(including the time for viral nucleic acid to turn negative,hospital stay,and 28-day follow-up mortality)and changes in cardiopulmonary function indicators[pulmonary artery pressure,tricuspid annular plane systolic excursion(TAPSE),left ventricular stroke volume(SV),and lung ultrasounol score(LUS)]before and after treatment were also observed,and the Kaplan-Meier curve was drawn to analyze the 28-day cumulative survival rate of the two groups.Results There was no statistically significant difference in the time for viral nucleic acid to turn negative and hospital stay between the two groups.Compared with the control group,the 28-day mortality in the study group was significantly lower[6.5%(2/31)vs.25.0%(13/52),P<0.05].Compared with before treatment,pulmonary artery pressure gradually decreased,TAPSE significantly increased,and left ventricular SV significantly increased after treatment in the study group,and the differences were statistically significant compared with 10 days after treatment[pulmonary artery pressure(mmHg,1 mmHg≈0.133 kPa):28.84±8.71 vs.34.68±10.76,TAPSE(cm):2.37±0.11 vs.2.03±0.41,SV(mL):68.68±7.17 vs.59.61±6.73,all P<0.01].Pulmonary lesions,especially bilateral pulmonary exudative lesions,significantly improved compared with before treatment,atelectasis improved significantly,and LUS significantly decreased(14.77±5.33 vs.20.32±5.63,P<0.01).Kaplan-Meier curve analysis showed that the 28-day cumulative survival rate in the study group was significantly higher than that in the control group(Log-Rank test:χ2=4.510,P=0.034).Conclusion Active use of positive pressure ventilation and early administration of drugs to improve pulmonary circulation in patients in high-altitude areas can significantly reduce pulmonary artery pressure and significantly improve left and right heart function and pulmonary exudative lesions.These improvements may reduce the mortality rate of viral pneumonia and viral infections complicated with underlying heart and lung diseases in high-altitude areas.

Objective To observe the efficacy of positive pressure oxygen therapy combined with drugs to improve pulmonary circulation in the treatment of severe viral pneumonia in high-altitude areas.Methods A two-way cohort study was conducted.Patients with severe viral pneumonia and those with common viral pneumonia complicated with underlying heart and lung diseases admitted to department of intensive care unit of Xizang Autonomous Region People's Hospital were selected as the research subjects.Patients who received conventional treatment in the early stage were assigned to the control group,while those who received conventional treatment plus active positive pressure oxygen therapy combined with drugs to improve pulmonary circulation in the later stage were assigned to the study group.The treatment effective rates of the two groups were observed(including the time for viral nucleic acid to turn negative,hospital stay,and 28-day follow-up mortality)and changes in cardiopulmonary function indicators[pulmonary artery pressure,tricuspid annular plane systolic excursion(TAPSE),left ventricular stroke volume(SV),and lung ultrasounol score(LUS)]before and after treatment were also observed,and the Kaplan-Meier curve was drawn to analyze the 28-day cumulative survival rate of the two groups.Results There was no statistically significant difference in the time for viral nucleic acid to turn negative and hospital stay between the two groups.Compared with the control group,the 28-day mortality in the study group was significantly lower[6.5%(2/31)vs.25.0%(13/52),P<0.05].Compared with before treatment,pulmonary artery pressure gradually decreased,TAPSE significantly increased,and left ventricular SV significantly increased after treatment in the study group,and the differences were statistically significant compared with 10 days after treatment[pulmonary artery pressure(mmHg,1 mmHg≈0.133 kPa):28.84±8.71 vs.34.68±10.76,TAPSE(cm):2.37±0.11 vs.2.03±0.41,SV(mL):68.68±7.17 vs.59.61±6.73,all P<0.01].Pulmonary lesions,especially bilateral pulmonary exudative lesions,significantly improved compared with before treatment,atelectasis improved significantly,and LUS significantly decreased(14.77±5.33 vs.20.32±5.63,P<0.01).Kaplan-Meier curve analysis showed that the 28-day cumulative survival rate in the study group was significantly higher than that in the control group(Log-Rank test:χ2=4.510,P=0.034).Conclusion Active use of positive pressure ventilation and early administration of drugs to improve pulmonary circulation in patients in high-altitude areas can significantly reduce pulmonary artery pressure and significantly improve left and right heart function and pulmonary exudative lesions.These improvements may reduce the mortality rate of viral pneumonia and viral infections complicated with underlying heart and lung diseases in high-altitude areas.

Objective:To investigate the clinical characteristics and prognosis of Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) patients with additional chromosomal abnormalities.Methods:The data of 351 CML patients with Ph-positive in the Affiliated Hospital of Qingdao University from January 2009 to January 2019 were retrospectively analyzed. The bone marrow chromosomal karyotype analysis of all patients was performed by using R-banding technique. The clinical characteristics and karyotype of Ph-positive CML patients with additional chromosomal abnormalities at initial diagnosis were summarized, and Kaplan-Meier was used to analyze the differences in overall survival (OS) of patients with different karyotypes.Results:Among 351 patients with Ph-positive CML, 32 (9.1%) cases had variant translocation. At initial diagnosis, 47 cases had additional chromosomal abnormalities including 29 cases in chronic phase accounting for 9.15% (29/317) of all patients in chronic phase, 3 cases in accelerated phase accounting for 25.00% (3/12) of all patients in accelerated phase, 15 cases in blast crisis accounting for 68.18% (15/22) of all patients in blast crisis; there was a statistically significant difference in the chromosomal abnormalities rate of all different phases ( χ2=50.799, P<0.05). Among 47 Ph-positive CML patients with additional chromosomal abnormalities, 13 patients had complex karyotypes with more than 3 additional chromosomal abnormalities, the proportion of complex karyotypes in chronic phase, accelerated phase and blast crisis was 13.79% (4/29), 33.33% (1/3) and 53.33% (8/15), respectively, and the difference was statistically significant ( χ2=9.26, P<0.05). The study showed that the most common additional chromosomal abnormalities in chronic phase were double Ph (48.28%, 14/29) and -Y (10.34%, 3/29), while the most common chromosomal abnormalities in the blast crisis were +8 (26.67%, 4/15) and double Ph (26.67%, 4/15). Kaplan-Meier survival analysis showed that at initial diagnosis the OS time of patients with additional chromosomal abnormalities was worse than that of those with the non-additional chromosomal abnormalities group ( χ2 = 61.138, P<0.05). The OS of patients with complex karyotypes for Ph - positive CML patients with additional chromosomal abnormalities at initial diagnosis was worse than that of patients with non-complex karyotypes, and the difference was significant ( χ2 = 4.945, P < 0.05). Conclusions:The additional chromosomal abnormalities is closely related to the progression of CML, and the prognosis of CML patients with additional chromosomal abnormalities is poorer than that of patients with only Ph translocation. Moreover, the more complex the additional chromosomes are, the more likely blastic changes are, and the poorer prognosis. And additional chromosomeal abnormalities during the treatment of CML patients may also lead to the progression of blastic changes.

Objective To explore the value of modified early warning score (MEWS) in clinical status assessment and outcome prediction of heat stroke patients.Methods The clinical data of 46 heat stroke patients were collected.According to the severity,the subjects were divided into mild group and severe group;and alternatively,according to the treatment outcomes,the subjects were also divided into survival group and death group.The MEWS at admission was employed for comparison of the differences in severity and outcome of heat stroke between groups.Receiver operating characteristic curve (ROC curve) was used to evaluate the accuracy of MEWS used at admission in assessing severity and predicting outcome of heat stroke patients.Results The results of MEWS calculated at admission in mild and severe heat stroke patients showed significant difference between them (3.00 ± 1.70 vs.6.85 ± 3.03,P =0.004).The area under the ROC curve (AUC) of MEWS got at admission for the diagnosis of severe heat stroke was 0.864 ± 0.056.The results of MEWS obtained at admission in survived and died heat stroke patients were 5.13 ± 2.96 and 9.25 ± 2.05,respectively (P =0.037).The AUC of MEWS used at admission for predicting the death of heat stroke patients was 0.867 ± 0.061.Conclusions The initial MEWS is useful to accurately assess and predict the outcome of heat stroke patients.Heat stroke patients with higher level of MEWS used at admission than 4.5 could be diagnosed as severe heat stroke,and whereas the value of MEWS got at admission higher than 7.5 could be the indicator of the poor prognosis.