Objective:To construct the prokaryotic expression vector of Coxsackievirus A16(CA16)viral protein 1(Vp1),express it in Escherichia coli(E.coli)BL21,purify the protein,prepare rabbit polyclonal antibodies,and identify the immunoreactivity of the antibodies.Methods:Bioinformatics online tools were used to predict the amino acid composition,conserved domains,secondary and tertiary structures of the Vp1 protein.The Vp1 gene of CA16 was amplified and cloned into the prokaryotic expression vector pET28a(+).The pET28a-Vp1 was transformed into E.coli BL21,and the expression was induced using isopropyl β-D-thiogalactopyranoside(IPTG).Western blotting method was used to identify the induced expression of Vp1 protein,and the induction time and temperature were optimized to improve the expression efficiency.Two female SPF New Zealand white rabbits were taken,and the purified recombinant protein Vp1 was used to immunize the rabbits to prepare rabbit anti-Vp1 protein polyclonal antibodies.The antibody titer was determined by ELISA method,and the immunoreactivity of the antibodies was identified by Western blotting method.Results:The bioinformatics analysis results showed that the Vp1 gene encoded 297 amino acids,with a relative molecular mass of 33 046.39 and an isoelectric point of 8.32,belonging to a hydrophilic protein;in the secondary structure,α-helix accounted for 15.15％,random coil accounted for 67.68％,and extended strand accounted for 17.17％.Sequencing of the recombinant plasmid pET28a-Vp1 confirmed that the pET28a-Vp1 plasmid was correctly constructed.The Western blotting results showed that the target protein was expressed in the IPTG induction group at a relative molecular mass of 33 000,and the target protein was mainly expressed in inclusion bodies.The optimal induction conditions for protein expression were IPTG concentration of 0.4 mmol·L-1,temperature of 16℃,and induction time of 20 h.The ELISA assay results showed that the titer of the rabbit polyclonal antibody was 1:1 024 000.The Western blotting results showed that the Vp1 rabbit polyclonal antibody could bind to the viral Vp1 protein in the CA16-infected cells.Conclusion:The polyclonal antibody against CA16 Vp1 is successfully prepared,and this antibody has significant binding characteristics to CA16 Vp1,which can be used for the diagnosis of enterovirus infection and the development of treatment methods.

In June 2018,sows at a pig farm in Jiamusi,Heilongjiang Province,suffered a large num-ber of miscarriages,and subsequently weaned piglets at the farm began to show persistent high fe-ver symptoms at around 35 days of age,with some pigs having a fever of more than 41.5 ℃.In or-der to determine the cause of this outbreak,63 clinical samples from this farm were tested.The re-sults showed that 60 out of 63 samples were positive for the porcine reproductive and respiratory syndrome virus(PRRSV)antigen.Subsequently,PRRSV antigen-positive plasmid was transfected into African green monkey embryonic kidney cells(Marc-145),and after three generations of blind transmission,indirect immunofluorescence assay(IFA)was performed.The results showed that one PRRSV strain,named HLJ38,was successfully isolated.Then the whole genome of HLJ38 strain was sequenced and then analyzed in detail by bioinformatics software.Sequence analysis showed that there were three deletions of 131 amino acids(323-433 aa,483 aa and 504-522 aa)in the derived sequence of Nsp2 gene of HLJ38 strain,which was consistent with the molecular ge-netic marker of NADC30 PRRSV.The phylogenetic tree analysis showed that HLJ38 and NADC30 PRRSV in GenBank belong to lineage 1 subgroup,and the nucleotide homology of HLJ38 and NADC30 PRRSV in GenBank was only 85.2％and 84.6％.Recombinant analysis showed that HLJ38 was a recombinant NADC30-like PRRSV,and the recombinant gene fragments were de-rived from multiple strains,among which the fragment of 1-201 nt was provided by VR2332 strain and fragment of 6 641-8 061 nt derived from the HP-PRRSV strain.In summary,the re-sults showed that the outbreak in this pig farm may be caused by the recombination of PRRSV strains among different lineages,and the recombinant circulating strains not only have certain pathogenicity but also suggest that the existing commercial vaccines provide limited cross-protec-tion against them.Recombination between different lineages increases the genetic diversity of PRRSV and aggravates the difficulty of prevention and control of PRRS in pig farms.Therefore,it is necessary to continuously monitor the epidemic dynamics of PRRSV in pig farms and take effec-tive measures in time to curb the spread of PRRS.

In June 2018,sows at a pig farm in Jiamusi,Heilongjiang Province,suffered a large num-ber of miscarriages,and subsequently weaned piglets at the farm began to show persistent high fe-ver symptoms at around 35 days of age,with some pigs having a fever of more than 41.5 ℃.In or-der to determine the cause of this outbreak,63 clinical samples from this farm were tested.The re-sults showed that 60 out of 63 samples were positive for the porcine reproductive and respiratory syndrome virus(PRRSV)antigen.Subsequently,PRRSV antigen-positive plasmid was transfected into African green monkey embryonic kidney cells(Marc-145),and after three generations of blind transmission,indirect immunofluorescence assay(IFA)was performed.The results showed that one PRRSV strain,named HLJ38,was successfully isolated.Then the whole genome of HLJ38 strain was sequenced and then analyzed in detail by bioinformatics software.Sequence analysis showed that there were three deletions of 131 amino acids(323-433 aa,483 aa and 504-522 aa)in the derived sequence of Nsp2 gene of HLJ38 strain,which was consistent with the molecular ge-netic marker of NADC30 PRRSV.The phylogenetic tree analysis showed that HLJ38 and NADC30 PRRSV in GenBank belong to lineage 1 subgroup,and the nucleotide homology of HLJ38 and NADC30 PRRSV in GenBank was only 85.2％and 84.6％.Recombinant analysis showed that HLJ38 was a recombinant NADC30-like PRRSV,and the recombinant gene fragments were de-rived from multiple strains,among which the fragment of 1-201 nt was provided by VR2332 strain and fragment of 6 641-8 061 nt derived from the HP-PRRSV strain.In summary,the re-sults showed that the outbreak in this pig farm may be caused by the recombination of PRRSV strains among different lineages,and the recombinant circulating strains not only have certain pathogenicity but also suggest that the existing commercial vaccines provide limited cross-protec-tion against them.Recombination between different lineages increases the genetic diversity of PRRSV and aggravates the difficulty of prevention and control of PRRS in pig farms.Therefore,it is necessary to continuously monitor the epidemic dynamics of PRRSV in pig farms and take effec-tive measures in time to curb the spread of PRRS.

Objective To explore the effect of enhanced recovery after surgery(ERAS)in perioperative period of complicated appendicitis in children.Methods A total of 248 children with complicated appendicitis who underwent laparoscopic surgery in Quanzhou Children's Hospital from January 2020 to January 2023 were selected and divided into control group and ERAS group according to random number table method,with 124 cases in each group.Both groups of patients underwent laparoscopic appendectomy.The control group received traditional treatment during perioperative period,while the ERAS group received treatment based on the concept of ERAS.The first postoperative exhaust/defecation time,hospital stay,visual analogue scale(VAS)score,postoperative complications and hospitalization satisfaction were compared between two groups.Results The time of first postoperative exhaust/defecation and hospital stay in ERAS group were significantly shorter than those in control group,total incidence of postoperative complications and postoperative VAS score were significantly lower than those in control group,and hospitalization satisfaction was significantly better than that in control group(P<0.05).Conclusion ERAS implementation during perioperative period of complicated appendicitis in children can promote early postoperative recovery,reduce postoperative pain,reduce the incidence of complications,and improve hospitalization satisfaction,which is worthy of clinical promotion and application.

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 assess the value of chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) for the prenatal diagnosis of chromosomal mosaicisms. METHODS: A total of 775 pregnant women who had visited the Prenatal Diagnosis Center of Yancheng Maternal and Child Health Care Hospital from January 2018 to December 2020 were selected as study subjects. Chromosome karyotyping analysis and CMA were carried out for all women, and FISH was used to validate the suspected mosaicism cases. RESULTS: Among the 775 amniotic fluid samples, karyotyping has identified 13 mosaicism cases, which yielded a detection rate of 1.55%. Respectively, there were 4, 3, 4 and 2 cases for sex chromosome number mosaicisms, abnormal sex chromosome structure mosaicisms, abnormal autosomal number mosaicisms and abnormal autosomal structure mosaicisms. CMA has only detected only 6 of the 13 cases. Among 3 cases verified by FISH, 2 cases were consistent with the karyotyping and CMA results, and clearly showed low proportion mosaicism, and 1 case was consistent with the result of karyotyping but with a normal result by CMA. Eight pregnant women had chosen to terminate the pregnancy (5 with sex chromosome mosaicisms and 3 with autosomal mosaicisms). CONCLUSION For fetuses suspected for chromosomal mosaicisms, CMA, FISH and G-banding karyotyping should be combined to determine the type and proportion of mosaicisms more precisely in order to provide more information for genetic counseling.
Female ; Pregnancy ; Humans ; Mosaicism ; In Situ Hybridization, Fluorescence ; Chromosome Disorders/genetics* ; Prenatal Diagnosis/methods* ; Chromosome Aberrations ; Sex Chromosome Aberrations ; Microarray Analysis/methods* ; Chromosomes

Chronic cough can occur in children of all ages, and the incidence rate and consultation rate increase each year.Clarifying the cause of chronic cough is the key to treatment.At present, there are no convenient, operable and unified standards for etiological analysis of chronic cough in the world.Therefore, the etiological analysis of chronic cough has always been a hot topic in clinical research.With the development of diagnosis and treatment technology, the role of pulmonary function and exhaled nitric oxide in the diagnosis of chronic cough has attracted attention.This article reviews the application value of pulmonary function combined with exhaled nitric oxide in etiology analysis of chronic cough in children, to provide reference for etiology analysis of chronic cough in children.

Novel coronavirus (2019-nCoV) is the pathogen of COVID-19. Some severe cases may suffer from respiratory failure or even death, which poses a great challenge to global public health. 2019-nCoV proteins not only participate in virus proliferation, but also play an important role in antagonizing host innate immune response, especially interferon response. In this paper, 2019-nCoV proteins involved in regulating host interferon response and the complex interaction between 2019-nCoV and interferons were summarized, aiming to provide a theoretical reference for the prevention and control of COVID-19.

Objective:To investigate the clinicopathological features, diagnosis and prognosis of diffuse leptomeningeal glioneuronal tumor (DLGNT).Methods:Five cases of DLGNT diagnosed from January 2016 to January 2020 were collected from Xuanwu Hospital, Capital Medical University. The clinical features, histopathologic characteristics, immunohistochemical and molecular genetic findings and prognosis were analyzed and the relevant literature was reviewed.Results:The five patients (two males and three females) were aged 2 to 52 years (median 11 years), and had history of increased intracranial pressure (headache and vomiting) or limb weakness. Three of them were younger than 16 years of age. The imaging studies showed diffuse intracranial and intraspinal nodular leptomeningeal thickening and enhancement, with or without parenchymal involvement. At times there were associated small cyst-like lesions. Imaging interpretations were inflammatory lesions in three cases and space occupying lesions in two. Microscopically, in three cases the tumors showed low to moderate cellularity, consisting of relatively monomorphous oligodendrocyte-like cells arranged in small nests or diffusely distribution. No mitosis and necrosis were observed. In two cases there were increased cellularity with a diffuse honeycomb pattern. The tumor showed mild to moderate polymorphism with hyperchromatic nuclei. Mitosis, endothelial vascular proliferation and glomeruloid vessels were seen. Necrosis was absent. The tumor cells in all five cases were positive for synaptophysin,Olig2 and negative for IDH1 and H3 K27M. GFAP was focally positive in four cases and only one case expressed NeuN partly. The Ki-67 labeling index was 1%-35%. BRAF fusion was detected in four cases. Genetic analysis showed solitary 1p deletion in two cases (2/5), while all cases were negative for 1p/19q co-deletion (0/5). The five patients were followed up for 13 to 28 months (median 15 month). One patient died after 27 months. There was no evidence of tumor progression in the remaining four patients.Conclusions:DLGNT is rare and easily confused with other central nervous system tumors and inflammatory lesions. Therefore, the diagnosis of DLGNT should be made based on comprehensive information including imaging, morphologic and corresponding immunohistochemical examinations and molecular genetics to avoid misdiagnosis and delay in management.

Objective:To evaluate the effect of propofol on right ventricular hypertrophy induced by pulmonary arterial hypertension (PAH) in rats.Methods:Twenty-two clean-grade healthy adult male Wistar rats, weighing 250-280 g, were divided into 3 groups using a random number table method: control group (group C, n=8), PAH group (group PH, n=6) and propofol group (group P, n=8). In PH and P groups, monocrotaline 60 mg/kg was injected intraperitoneally to establish the model of PAH, while the equal volume of normal saline was administered in group C. Propofol 100 mg/kg was injected intraperitoneally twice a week for 6 consecutive weeks starting from 2 weeks after establishment of the model in group P. The weight of rats was measured before establishment of model and after administration, and the weight difference (△BW=weight after administration-weight before administration) was calculated.At the end of administration, the right ventricular end-diastolic dimension (RVEDD), right ventricular wall thickness in diastole (RVWTd), intraventricular septum in diastole (IVSd), left ventricular posterior wall in diastole (LVPWd) and maximal velocity of pulmonic valve (PV) were measured using cardiac ultrasound.The animals were then sacrificed, and the lungs and hearts were removed for examination of the pathological changes (after haematoxylin and eosin staining) and for determination of the degree of myocardial fibrosis in right ventricular (by Masson staining), expression of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in lung tissues and myocardial tissues of the right ventricle (by immunohistochemistry). Results:Compared with group C, △BW and PV were significantly decreased, RVWTd, IVTd and RVEDD were increased, the thickness of the wall of pulmonary arterioles and myocardial cell penetration area in right ventricular were increased, the expression of IL-6 and TNF-α in lung tissues and myocardial tissues of right ventricle was up-regulated ( P<0.05 or 0.01), inflammatory cell infiltration and structural disorders were found in lung tissues, and intercellular spaces were widened, and the myocardial tissue was extensively fibrotic in group PH.Compared with group PH, △BW and PV were significantly increased, RVWTd, IVTd and RVEDD were decreased, the thickness of the wall of pulmonary arterioles and myocardial cell penetration area (the area of cardiomyocytes in which the nucleus located in the middle) were decreased, the expression of IL-6 and TNF-α in lung tissues and myocardial tissues of right ventricle was down-regulated ( P<0.05 or 0.01), inflammatory cell infiltration, structural disorders, intercellular spaces and degree of fibrosis were improved in group P. Conclusion:Propofol can alleviate right ventricular hypertrophy induced by PAH, and the mechanism is probably related to reduction of inflammatory responses in rats.