60 kg) was given to all the patients 1-3 days after their operation.The pacing threshold and the amplitude of P and R waves on cardiograph were measured before injection and at 10,30,90,180 minutes afterwards.Results No significant changes were oburved in pacing threshold and the amplitade of P and R waves before and after the injection of metoprolol in patients with either newly implanted or replacement of permanent pacemakers.Conclusion Metoprolol tartrate has no effect on atrial and ventricular pacing threshold and the amplitude of P and R waves in patients with permanent pacemakers implantation.

Objective To investigate the effect of small interfering RNA (siRNA) targeting cytoplasmic domain of tissue factor on apoptosis of vascular endothelial cells. Methods Specific siRNA targeting cytoplasmic domain of tissue factor were designed, and synthetic oligos were inserted into plasmid DNA. The siRNA constructs were transfected into human umbilical vascular endothelial cells (HUVEC) with liposome. The HUVEC were transfected with the constructs encoding siRNA Ⅰ, siRNA Ⅱ and pcDNA~(TM)6.2 GW/-miR plasmid separately. The transfected HUVEC were mixed with CD8~+ T lymphocytes. The apoptotic rate of tranfected HUVEC mixed with lymphocytes was analyzed by flow cytometry. Magnetic beads were used to measure PT of the supematant in the mixed lymphocytes culture. Results The siRNA constructs were confirmed by DNA sequence analysis. The apoptotic rate of HUVEC transfected with siRNA Ⅰ and Ⅱ plasmids was decreased significantly as compared with the empty control group (P<0.01). The apoptosis rate of HUVEC transfected with siRNA Ⅰ plasmid was lower than that of HUVEC transfected with siRNA Ⅱ plasmid (P<0.05). APTT of the culture supernatants in the three transfection groups was lower in the control groups (P <0.05), but there was significant difference among the three transfection groups. Conclusion The siRNA targeting cytoplasmic domain of tissue factor were successfully constructed, siRNA can protect HUVEC, and reduce the apoptotic rate of endothelial cells in mixed lymphocyte reaction without influencing the coagulation function.

Objective:To compare the clinical characteristics and etiology changes of patients with bronchiolitis before the pandemic of coronavirus disease 2019(COVID-19)with those after the pandemic, and to provide a basis for the clinical diagnosis, treatment and prevention of bronchiolitis.Methods:Retrospective analysis were made on the clinical characteristics and etiological changes of patients who were hospitalized with bronchiolitis in the Department of Pulmonology, Children′s Hospital of Soochow University before COVID-19 pandemic(from February 1, 2019 to January 31, 2020, called as Group 2019-2020)and after COVID-19 pandemic(from February 1, 2020 to January 31, 2021, called as Group 2020-2021). Medical records were reviewed to compare general conditions, clinical manifestations, and laboratory tests.Nasopharyngeal secretion examination results were collected to compare the differences in pathogenic composition.Results:A total of 285 patients were enrolled in the Group 2019-2020, while 190 patients in the Group 2020-2021.There were no significant differences in gender, age, symptom duration prior to admission and length of stay between the two groups( P>0.05). The proportion of moderate/severe cases in the Group 2020-2021 was lower than that in the Group 2019-2020[10.53%(20/190)vs 21.75%(62/285)]and the difference was statistically significant( χ2=10.062, P<0.05). The proportion of stuffy nose rhinorrhea in the Group 2020-2021 was higher than that in the Group 2019-2020, while the proportion of gastrointestinal symptoms(vomiting and diarrhea)in the Group 2020-2021 was lower than that in the Group 2019-2020 [57.37%(109/190)vs 47.37%(135/285)and 15.79%(30/190)vs 24.56 %(70/285)]and the differences were statistically significant( χ2 were 4.563 and 5.278 respectively, all P<0.05). There were no significant differences in the proportions of fever, dyspnea, shortness of breath and cyanosis between the two groups(all P>0.05). The creatine kinase isoenzyme(CK-MB)in the Group 2020-2021 was lower than that in the Group 2019-2020[4.15(2.90~5.60)vs 6.70(4.20~22.10)]and the difference was statistically significant( Z=-8.757, P<0.05). There were no statistically significant differences in white blood cell count(WBC), percentage of neutrophil(N%), blood platelet count(PLT), percentage of eosinophil(EOS%), C-reactive protein(CRP), alanine aminotransferase(ALT)and lactate dehydrogenase(LDH)between the two groups(all P>0.05). The total pathogen detection rate, positive rate of respiratory syncytial virus(RSV), positive rate of mycoplasma pneumoniae(MP)and mixed infection rate in the Group 2020-2021 were lower than those in the Group 2019-2020[65.26%(124/190)vs 75.09%(214/285), 14.21%(27/190)vs 30.18%(86/285), 6.32%(12/190)vs 15.09%(43/285), 16.84%(32/190)vs 25.61%(73/285)], with statistically significant differences( χ2 were 5.361, 16.026, 8.568 and 5.094 respectively, all P<0.05). The positive rate of rhinovirus in the Group 2020-2021 was higher than that in the Group 2019-2020[13.16%(25/190)vs 4.91%(14/285)]and the difference was statistically significant( χ2=10.285, P<0.05). There were no significant differences in the positive rates of human metapneumovirus, Boca virus and parainfluenza virus 3 between the two groups(all P>0.05). Conclusion:The clinical characteristics and etiology of patients with bronchiolitis have changed after the COVID-19 pandemic.The quarantine and protection measures reduce the transmission of associated pathogens and the severity of the disease.

Objective:To investigate the clinical characteristics and risk factors of bronchiolitis obliterans (BO) after adenovirus pneumonia.Methods:Clinical data of 266 children with adenovirus pneumonia hospitalized in Children′s Hospital of Soochow University from January 2011 to December 2017 were retrospectively analyzed.Accor-ding to whether they developed BO, children with adenovirus pneumonia were divided into the BO group and the non-BO group.Clinical features of the BO group and the non-BO group were compared by t test, rank sum test or chi square test.Risk factors were analyzed by Logistic regression approach. Results:Among 266 children with adenovirus pneumonia included, 37 patients were developed into BO group, and their age was significantly younger than that of the non-BO group [12.0(8.0, 17.5) months vs.32.0(13.0, 48.0) months, P<0.001]. Compared with the non-BO group, there were more proportion of preterm infants[10.8%(4/37 cases) vs.3.1%(7/229 cases), P=0.028], more instances of comorbidities [21.6%(8/37 cases) vs.4.4%(10/229), P<0.001] and more children with allergic diseas[35.1%(13/37 cases) vs.20.1%(46/229 cases), P=0.041] in the BO group, and the difference was statistically significant.The duration of fever in the BO group was significantly longer than that of the non-BO group [10(4.0, 13.5) d vs.6(4.0, 9.0) d, P=0.011] children with symptoms of wheezing, shortness of breath, and hypoxemia in the BO group were significantly more than the non-BO group[81.1%(30/37 cases) vs.27.9%(64/229 cases), P<0.001; 64.9%(24/37 cases) vs.5.7%(13/229 cases), P<0.001; 59.5%(22/37 cases) vs.6.6%(15/229 cases), P<0.001]. The platelet count, IgG level, and CD3 -CD 19+ lymphocyte percentage were significantly higher in the BO group than the non-BO group [(364±104)×10 9/L vs.(297±105)×10 9/L, P=0.001; 6.74(4.92, 10.16) g/L vs.5.93(1.00, 8.04) g/L, P=0.016; (33.5±15.3)% vs.(26.1±10.2)%, P=0.008]. In contrast, the percentage of CD3 + CD4 + lymphocytes in the BO group was lower than the non-BO group[(29.1±8.0)% vs.(32.5±9.4)%, P=0.044], the difference was statistically significant.The BO group had a higher rate of mixed bacterial infection than the non-BO groups[37.8%(14/37 cases) vs.16.6%(38/229 cases), P=0.003]. An age<26 months, comorbidities, premature birth history, wheezing, shortness of breath, and hypoxemia were independent risk factors for BO after adenovirus pneumonia( OR=4.808, 30.667, 7.558, 3.909, 8.842, 8.607, all P<0.05). Conclusions:An age of less than 26 months, a history of premature delivery comorbidities, wheezing, shortness of breath and hypoxemia, are independent risk factors for BO after adenovirus pneumonia.Children with above manifestations should receive high resolution CT as soon as possible to determine whether it is BO.

Objective:To investigate the clinical characteristics of influenza A and influenza B pneumonia and the risk factors of severe influenza pneumonia in children.Methods:The epidemiology, clinical characteristics, laboratory tests and pathogens of co-infection in children with pneumonia caused by influenza A virus and influenza B virus, and the risk factors of severe influenza pneumonia were retrospectively analyzed.Results:(1) The cases of influenza A infection accounted for 65.1% and those with influenza B infection accounted for 32.9% among the 711 children with influenza pneumonia.The dominant strain was Influenza B Victoria virus in spring and summer, influenza A(H 3N 2) virus in autumn, and influenza A(H1N1) virus in winter.The dominant strain was influenza A virus at the age of < 1 year and ~3 years, influenza A virus and influenza B virus at the age of ~6 years, and influenza B virus at the age of &ge;6 years.(2) The gastrointestinal symptoms were more common in children with influenza B pneumonia compared with those with influenza A pneumonia(53.4% vs 44.7%, χ2=4.728, P=0.030), but crackles and wheezing were more common in children with influenza A pneumonia compared with those with influenza B pneumonia(80.1% vs 70.5%, 36.9% vs 25.6%, χ2=8.945, 8.093, all P<0.05). (3) The percentage of decreased lymphocyte count in children with influenza B pneumonia was higher than those with influenza A pneumonia(5.6% vs 1.9%, χ2=6.633, P=0.010). (4) Mixed Mycoplasma Pneumoniae was more common in children with influenza B pneumonia compared with those with influenza A pneumonia(23.9% vs 10.8%, χ2=20.789, P<0.001), and mixed virus and bacteria were more common in children with influenza A pneumonia compared with those with influenza B pneumonia(15.8% vs 8.1%, 50.1% vs 41.9%, χ2=7.934, 4.221, all P<0.05). (5) Multivariate logistic regression analysis showed that age <2 years( OR=1.886, 95% CI 1.149~3.096, P=0.012), increased LDH( OR=1.736, 95% CI 1.080~2.790, P=0.023), the percentage of lymphocyte decreased( OR=2.762, 95% CI 1.669~4.571, P<0.001) and the percentage of CD3 + decreased ( OR=6.019, 95% CI 3.993~9.331, P<0.001)were risk factors for severe influenza pneumonia. Conclusion:Among hospitalized children with influenza pneumonia, there were some differences in the age of infection, clinical characteristics, laboratory tests and pathogens of co-infection between the cases caused by influenza B and influenza A, and clinicians should remain vigilant for the occurrence of severe influenza pneumonia.