Objective:To isolate and identify SARS-CoV-2 epidemic strains and analyze the sequence characteristics of the virus strains following serial passages.Methods:Eleven nasopharyngeal swabs positive for SARS-CoV-2 antigen were collected from December 2022. Quantitative real-time PCR was used to detect SARS-CoV-2 nucleic acid, and positive specimens were inoculated onto Vero cells for virus isolation. The isolated strains were identified by Western blot and indirect immunofluorescence assay. The morphology of the isolated strains was observed using transmission electron microscopy. Nucleic acid was extracted from the isolates and passaged viruses for further sequencing and analysis.Results:All 11 specimens tested positive for SARS-CoV-2 using quantitative real-time PCR. SARS-CoV-2 strains were successfully isolated from seven specimens, and could be adaptively cultured, passaged, and expanded on Vero cells, achieving a peak titer exceeding 10 6.25 50% cell culture infectious dose (CCID 50)/ml. Western blot and indirect immunofluorescence results showed that the isolates could be specifically recognized by monoclonal antibodies and convalescent serum against SARS-CoV-2. Transmission electron microscopy revealed oval-shaped viral particles with diameters of approximately 100 nm. Next-generation sequencing of the viral isolates demonstrated a sequence homology greater than 99.50% with the Wuhan-Hu-1 reference strain (NC_045512) and 99.98% among the seven isolated strains, and all of the isolates belonged to the Omicron BF.7 variant. Sequence analysis after continuous passage and plaque purification of the BJ-NVSI-20230005 isolate showed that compared with passages 1-3, passages 4-6 had one nucleotide site mutation (C→T) in the ORF1ab gene and a deletion of 3 bp in the E gene, which resulted in a change from leucine to phenylalanine and the deletion of valine, respectively. Polymorphisms were observed in the sequences of plaque-purified clones. Conclusions:The seven successfully isolated SARS-CoV-2 strains all belong to the SARS-CoV-2 BF.7 variant, which is consistent with the prevalence trend in mainland China in December 2022.

Objective:To study the expression and significance of neutrophil extracellular traps (NETs) in neonatal sepsis.Methods:Prospective research were used in this study. Term infants with neonatal sepsis hospitalized for the first time in the Department of Neonatology, Children's Hospital of Soochow University from June 2020 to November 2020 were selected as the sepsis group. According to a ratio of about 1∶1, term infants with mild hyperbilirubinemia who were admitted in the same period, with gestational age difference less than 1 week from those in the sepsis group, and whose parents agreed to participate in the study were selected as the control group. On admission, clinical data as well as blood samples of the two groups were collected. Levels of NETs marker citrulline histone H3-DNA (CitH3-DNA) were detected by Enzyme-linked immunosorbent assay, and circulating cell-free DNA (cfDNA) was tested by the fluorescence microplate reader. General data, white blood cell (WBC), neutrophil count (NE), platelet (PLT), C- reactive protein (CRP), blood culture, CitH3-DNA and cfDNA were compared between the two groups. The diagnostic value of CITH3-DNA and cfDNA in neonatal septicemia was analyzed by the receiver operating characteristic (ROC) curve.Results:A total of 74 infants were included in the study, including 39 cases in the sepsis group and 35 cases in the control group. CitH3-DNA and cfDNA in the sepsis group were significantly higher than those in the control group [CitH3-DNA (optical density): 0.85±0.05 vs. 0.48±0.03, cfDNA (mg/L): 0.90±0.05 vs. 0.56±0.03] ( P<0.01). There was no significant correlation between CitH3-DNA and cfDNA. The level of CitH3-DNA had no correlation with gender, gestational age, age, birth weight, WBC, NE, PLT and CRP ( P>0.05). cfDNA was positively correlated with age and NE ( P<0.05), and negatively correlated with PLT ( P<0.05). Combined with CRP, the area under the ROC curve of CitH3-DNA+CRP, cfDNA+CRP, and CitH3-DNA+cfDNA+CRP were 0.947, 0.947 and 0.970 respectively, and the sensitivity to predict neonatal sepsis were 92.3%, 84.6% and 94.9% respectively, the specificity were 94.3%, 97.1% and 100% respectively, all higher than the predictive value of each index alone. Conclusions:The plasma NETs levels increase significantly in neonatal sepsis patients, especially CitH3-DNA with a strong specificity, and can be considered as a biomarker for early diagnosis of neonatal sepsis. NETs together with CRP, could drastically improve the predictive value of neonatal sepsis.

The clinical data of a child with bronchial Dieulafoy disease treated in Wuhan Children′s Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, was analyzed retrospectively.The patient was a 9-month-old boy, who was admitted to hospital due to " intermittent hematemesis vomiting blood for 6 hours" . Chest CT suggested ground-glass opacity in both lungs.Electronic bronchoscopy showed that the neoplasm bulged into the lumen at the opening of the right inferior lobar bronchus, and fresh blood oozed from the basal segment of the neoplasm during the operation.Bronchial arteriography and transcatheter bronchial artery embolization were performed due to recurrent hemoptysis, during which the patient was diagnosed with bronchial arterial vascular malformation and finally diagnosed with bronchial Dieulafoy disease after consulting the relevant literatures.The disease is infrequent and characterized by rupture hemorrhage of bronchial submucosal malformed artery, the etiology and pathogenesis of which are still unclear, and it may be related to congenital vascular malformation in children.Bronchoscopy for hemoptysis of unknown cause in children should be performed with caution.If small and smooth protruded nodular lesions are seen under the bronchoscope, the bronchial Dieulafoy disease should be considered, and the lesions should not be touched too much or subjected to biopsy blindly.Fatal massive hemorrhage can be avoided by bronchial arteriography and bronchial artery embolization.

Objective Toinvestigatetheinterventionaltreatmentmethodsofbenignesophagealstenosisinchildren,includingballoondilation, stentimplantationandcontinuousballoondilation.Methods 42casesofesophagealstenosisdiagnosedbybariumexaminationinour hospitalfromJanuary2010toJune2017.Accordingtothetreatmentmethods,theyweredividedintoballoondilationgroup(13cases),stent implantationgroup (11cases),continuousballoondilationgroup (18cases),andthecomplicationsandrecurrenceratesofthree methodswerecompared.Results Balloonorstentsweresuccessfullyplacedorremovedinallcases,andtheclinicalsymptomswere significantlyimproved.Therewerenoseriouscomplicationssuchasruptureofesophagus,perforationandmassivehemorrhageI.nballoondilation group,restenosisoccurredin10cases3to10monthsafteroperation,withcomplicationsrateof76.9% andrecurrencerateof76.9%. Instentimplantationgroup,sentfallingoffordisplacedoccurredin4casesandrestenosisin4cases,withthecomplicationsrateof 72.7% andrecurrencerateof36.3%.Incontinuousballoondilationgroup,therewere2casesofballoondescendingand4casesof restenosis,withcomplicationsrateof33.3% andrecurrencerateof22.2%.Comparingthecomplication,theballoondilationgroup>thestentimplantationgroup(χ2=0.056,P>0.05),thestentimplantationgroup>thecontinuousballoondilationgroup(χ2=4.243, P<0 .05 ),the balloon dilation group>the continuous balloon dilation group (χ2=5 .743 ,P<0 .05 ).Co m paring the recurrence rate ,the balloondilationgroup>thestentimplantationgroup(χ2=4.033,P<0.05),thestentimplanationgroup>thecontinuousballoondilationgroup (χ2=0.684,P>0.05),theballoondilationgroup>thecontinuousballoondilationgroup(χ2=9.120,P<0.05).Conclusion There aredifferentincidenceofcomplicationsandrecurrenceinthreemethods,andthecontinuousballoondilationissimplerandlesscomplicationsand recurrencethantheothertwomethods.Itcanbethefirstchoiceforinterventionaltreatmentofesophagealstenosis.

Objective To evaluate the clinical efficacy of superselective intravascular embolization in the treatment of large hemangiomas in children,and to provide a reliable basis for the clinical treatment and to predict prognosis.Methods The clinical and imaging data of 85 children with large hemangiomas who underwent superselective angiography and embolization were collected in our hospital from January 2015 to January 2018,and followed up for 3 months to 1.5 years.According to the DSA angiography of the hemangioma [artery origin,artery number,arterio-venous fistula(AVF)],and combined with age,tumor size and the selection and compatibility of embolization materials.Using the chi-square test to analyze these indicators.Results Analysis of the clinical efficacy indicators,was shown as the following:(1) Artery origin:The total effectiveness rate of single and mixed sources was 95.3％ (61/64),66.7％ (14/21) respectively.The difference was statistically significant (x2=0.688,P＜0.05).(2) Feeding artery number:The total effectiveness rate of 1 branch,2 branches and ≥3 branches was (3/3),(25/27)and (47/55) respectively.The difference was statistically significant (x2=1.944,P＜0.05).(3) Presence of fistula(AVF):The total effectiveness rate of AVF and without AVF was 36.4％ (4/11) and (95.9％,71/74) respectively.The difference was statistically significant (x2=0.806,P＜0.05).Other influencing factors including:(1)Age:the recurrence rate of patients≤5 months and＞5 months was 33.3％ (6/18) and 20.9％ (14/67)respectively.There was no significant difference (x2=1.220,P＞0.05);(2)Tumor size:The recurrence rate of φ≤80 mm and φ＞80 mm was 25.5％(13/51)and 32.4％(11/34) respectively.There was no significant difference (x2=0.474,P＞0.05).(3) Selection and compatibility of embolization materials:The recurrence rate of Lipiodol + bleomycin and gelatin sponge +bleomycin was 27.0％ (10/37) and 31.3％ (15/48) respectively.There was no significant difference (x2=0.179,P＞0.05).Conclusions The clinical efficacy of superselective intravascular embolization in the treatment of large hemangioma in children was influenced by:artery origin(mixed sources),artery number (≥3 branches),AVF,age tumor size,selection and compatibility of embolic materials.

Objective To study the clinical efficacy and complications of ultraselective endovascular embolization combined with local sclerotherapy in the treatment of large hemangioma in children,to provide a better choice for the treatment.Methods 85 cases of large hemangioma in our department in the last three years were analyzed retrospectively.Patients were divided into two groups according to the treatment:the simple treatment group (33 cases),ultraselective endovascular embolization,and the combination treatment group (52 cases),ultraselective endovascular embolization combined with local sclerotherapy or local sclerotherapy after endovascular embolization.The total effective rate and the incidence of complications between two groups were compared,and the patients were followed up for 3 months to 1.5 years.Results 85 cases of large hemangioma were successfully treated by simple ultraselective endovascular embolization or combined treatment.A total of 75 cases were treated effectively (complete cure,partial cure,condition improved)and 10 cases were ineffective and no recurrence or tumor enlargement in the follow-up .In the total effective rate,the combination treatment group [96.2% (50/52)]was superior to the simple treatment group [75.8% (25/33)](χ2=6.245,P=0.012 ).There was no significant difference in the complete cure rate between the two groups (χ2=1.561,P=0.212 ).The complication rate in the simple treatment group was slightly higher than that in the combined treatment group:36.4% (12/33)vs 32.7% (17/52)(χ2=0.064,P=0.996).Conclusion The total effective rate of ultraselective endovascular embolization combined with local sclerotherapy in the treatment of large hemangioma in children is better than simple endovascular embolization,and less complications,safely treatment and less trauma.It can be used as the first choice for treatment of large hemangioma.

One severely burned patient, caused by heat lead slag and combined with shock, was hospitalized in our burn unit on 2nd June, 2016. The patient received treatments including anti-shock, intensive care, anti-infection, and organ protection. On post injury day 16, the patient suffered outbreak of acute hemorrhagic necrotizing enteritis after eating dumplings. Plasma and albumin were given, octreotide was intravenously infused to inhibit the secretion of intestinal fluid, the broad-spectrum antibiotics were used for anti-infection, abdominal puncture and drainage were performed, sodium tanshinone ⅡA sulfonate was applied to improve the intestinal microcirculation, ulinastatin was applied to alleviate inflammatory reaction, somatostatin was given to reduce intestinal bleeding, and voriconazole was given for antifungal treatment. The patient gradually recovered and was finally cured and discharged. Among critically ill patients, gastrointestinal tract is not only the initiating organ of sepsis, but also one of the target organs which can be easily damaged during sepsis. This case reminds us the importance of gastrointestinal management in severely burned patients.

Objective To understand the antibody levels after the inoculation of measles ,poliomyelitis ,epidemic encephalitis B and hepatitis B vaccines among healthy children aged 7 - < 13 years old in Guangshui City of Hubei province to provide the scientif ‐ic basis for formulating the immune prevention and control strategy and risk assessment in whole city .Methods 4 616 healthy chil‐dren aged 7 - < 13 years old were sampled from the whole city .The enzyme‐linked immunosorbent assays (ELISA) was used to de‐tect the 4‐antibody levels .Results The antibody positive rates of measles ,poliomyelitis ,epidemic encephalitis B and hepatitis B a‐mong healthy children aged 7 - < 13 years old in Guangshui City were 94 .41% ,93 .07% ,93 .78% and 68 .72% respectively .The protection levels of first three kinds of antibody reached more than 85% ;the positive rates had statistical difference among 4 kinds of antibody(χ2 = 1 987 .08 ,P = 0 .000) .The antibody positive rates of epidemic encephalitis B had no statistical difference among different age periods (χ2 = 10 .141 ,P= 0 .071) ;the antibody positive rates of measles ,poliomyelitis and hepatitis B had statistical difference among different age periods(χ2 = 40 .471 ,P = 0 .000 ;χ2 = 25 .174 ,P = 0 .000 ;χ2 = 283 .641 ,P = 0 .000) .The positive rates of 4 kinds of antibody had no statistical difference between different genders (χ2 = 0 .019 ,P= 0 .889 ;χ2 = 1 .017 ,P= 0 .313 ;χ2 = 0 .018 ,P= 0 .892 ;P= 0 .639 ,P= 0 .424) ;the antibody positive rates of measles ,poliomyelitis and epidemic encephalitis B had no statistical differences among 17 villages and towns in the whole city (χ2 = 0 .099 ,P= 1 .000 ;χ2 = 0 .117 ,P= 1 .000 ;χ2 = 0 .134 , P= 1 .000) ,while the antibody positive rate of hepatitis B had statistical difference among these villages and towns (χ2 = 186 .179 , P= 0 .001) .Conclusion The antibody levels of measles ,poliomyelitis and epidemic encephalitis B reach the protection rate ,but the antibody level of hepatitis B needs to be increased .The monitoring work should be continuously strengthened and the seeking missed inoculation and re‐inoculation work should be reinforced .

Objective To explore risk factors,prevention and treatment of common complications of benign esophageal stenosis treated with the retrievable covered stents in children.Methods Fifteen cases,diagnosed as benign esophageal stenosis by barium esophagogram were treated with retrievable covered stents under fluoroscopy,Then the stents were removed after 2-3 weeks.The cases were followed-up and complications were observed.Results The stents were successful implanted in all cases.The diet was improved obviously after operation,and gradually transformed from liquid,semiliquid to normal feeding.At the same time,narrow section gradually expanded from 0.1-0.6 cm to 0.6-1.5 cm.Postoperative follow-up was in 1,2,3 weeks and 3 months.Main complications were stents shift in 5 cases,esophageal restenosis in 2 cases,esophageal-tracheal fistula in 1 case,postoperative dull pain behind sternum and foreign body sensation in 6 cases.Relevant preventions and treatments were performed based on different complications.Conclusion It should not be ignored that complications after covered stent placement are more in children than in adults,preventions and treatments should be taken positively.

Objective To explore therapeutic effects of different interventional approaches to neonatal Kasabach-Merritt syndrome (K-MS) Methods A retrospective analysis of therapeutic effects of different interventional approaches to K-MS in 12 neonates from May 2010 to August 2014. All the patients received local treatment (n=5), chemoembolization (n=4) and combined local treatment and endovascular chemoembolization (n=3), respectively, depending on size, location and blood supply of K-MS. The K-MS patients with angioma measuring< 5 cm, 5 to 10 cm and >5 cm received local treatment, endovascular chemoembolization and combined local treatment and endovascular chemoembolization, respectively. The patients were categorized as cured, improved and clinical inefficient, respectively, based on therapeutic effect. The criteria for cured patients were: (1) angioma faded completely or mostly; (2) the platelet count stabilized within the normal range; (3)no recurrence for more than six months. The criteria for improved patients were: (1) angioma shrinked significantly; (2) the platelet stabilized within the normal range. The criteria for clinical inefficient patients were: (1) agioma no obviously shrinked, the platelet count has no improvement over 2 months after interventional approaches. Results All the 12 patients with K-MS were cured and had no complication. Of the 12 patients, 5 patients received local treatment had decreased localized tension and ecchymosis of hemangioma at the first day of therapy, were cured after 2 to 7 courses of therapy. Of the 4 patients received endovascular chemoembolization, 3 were cured after one course of treatment, 1 had recurrent disease one month later after one course of therapy and were cured after the second course of treatment.One had recurrent disease a month later after one course of treatment and were cured after the second course of treatment. Three received combined local treatment and endovascular chemoembolization, angioma shrinked significantly and increased platelet count after the first course of treatment, and 2 to 3 courses local treatment were combined, hemangioma faded and platelet count stabilized within the normal range after 2 to 3 courses of local treatment. Conclusions Interventional therapy is the most effective treatment of neonatal K-MS.There are different interventional approaches to optimize treatment of neonatal K-MS depending on sizes, location and blood supply of K-MS.