ObjectiveTo establish an adjusted Serfling regression model to estimate the excess cases and the excess epidemic period of hand-foot-mouth disease (HFMD) in Beijing from 2011 to 2019, so as to provide data support and decision-making basis for HFMD prevention and control. MethodsThe weekly number of HFMD cases in Beijing from 2011 to 2019 was utilized for adjusted the Serfling regression model. Then the adjusted model was used to fit the baseline and epidemic threshold of HFMD in Beijing from 2011 to 2019, calculating the excess cases and determining the excess epidemic period. ResultsA total of 279 306 cases of HFMD were reported in Beijing from 2011 to 2019, with the climax of the disease occurring in summer and autumn. After adjusting the fitting R² of the Serfling regression model to 0.773, a total of 10 excess epidemic periods totaling 92 weeks were estimated, mainly occurring in summer. The highest number of excess cases during an excess epidemic period was found in 2014 (1 272 cases, 95%CI: 990‒1 554), accounting for 65.04% of the actual cases (95%CI: 50.62%‒79.46%). ConclusionThe adjusted Serfling regression model fits well and can be utilized for early warning of HFMD and estimating the disease burden caused by HFMD.

BACKGROUND:Tissue engineering has brought new hope to the clinical challenge of liver failure,and the preparation of plant-derived decellularized fiber scaffolds holds significant importance in liver tissue engineering. OBJECTIVE:To prepare apple tissue decellularized scaffold material by using fresh apple slices and a solution of sodium dodecyl sulfate,and assess its biocompatibility. METHODS:Fresh apples were subjected to decellularization using phosphate buffer saline and sodium dodecyl sulfate solution,separately.Afterwards,the decellularized apple tissues and apple decellularized scaffold materials were decontaminated with phosphate buffer saline.Subsequently,scanning electron microscopy was used to assess the effectiveness of decellularization of the apple materials.Adipose-derived mesenchymal stem cells were extracted from the inguinal fat BALB/C of mice,and their expression of stem cell-related markers(CD45,CD34,CD73,CD90,and CD105)was identified through flow cytometry.The cells were then divided into a scaffold-free control group and a scaffold group.Equal amounts of adipose-derived mesenchymal stem cells were seeded onto both groups.The biocompatibility of the decellularized scaffold with adipose-derived mesenchymal stem cells was evaluated using CCK-8 assay,hematoxylin-eosin staining,and phalloidine staining.Cell adhesion and growth on the scaffold were observed under light microscopy and scanning electron microscopy.Furthermore,the scaffold was subdivided into the non-induced group and the hepatogenic-induced group.Adipose-derived mesenchymal stem cells were cultured on the decellularized apple scaffold,and they were cultured for 14 days in regular culture medium or hepatogenic induction medium for comparison.Immunofluorescent staining using liver cell markers,including albumin,cytokeratin 18,and CYP1A1,was performed.Enzyme-linked immunosorbent assay was used to detect the secretion of alpha fetoprotein and albumin.Additionally,scanning electron microscopy was employed to observe the morphology of the induced cells on the scaffold,verifying the expression of liver cell-related genes on the decellularized scaffold material.Finally,the cobalt-60 irradiated and sterilized decellularized apple scaffolds were transplanted onto the surface of mouse liver and the degradation of the scaffold was observed by gross observation and hematoxylin-eosin staining after 28 days. RESULTS AND CONCLUSION:(1)The scanning electron microscopy results revealed that the decellularized apple scaffold material retained a porous structure of approximately 100 μm in size,with no residual cells observed.(2)Through flow cytometry analysis,the cultured cells were identified as adipose-derived mesenchymal stem cells.(3)CCK-8 assay results demonstrated that the prepared decellularized apple tissue scaffold material exhibited no cytotoxicity.Hematoxylin-eosin staining and phalloidine staining showed that adipose-derived mesenchymal stem cells were capable of adhering and proliferating on the decellularized apple tissue scaffold.(4)The results obtained from immunofluorescence staining and enzyme-linked immunosorbent assay revealed that adipose-derived mesenchymal stem cells cultured on the decellularized apple scaffolds exhibited elevated expression of liver-specific proteins,including albumin,alpha-fetoprotein,cytokeratin 18,and CYP1A1.These results suggested that they were induced differentiation into hepatocyte-like cells possessing functional characteristics of liver cells.(5)The decellularized apple scaffold implanted at 7 days has integrated with the liver,with partial degradation of the scaffold observed.By 28 days,the decellularized apple scaffold has completely degraded and has been replaced by newly-formed tissue.(6)The results indicate that the decellularized scaffold material derived from apple tissue demonstrates favorable biocompatibility,promoting the proliferation,adhesion,and hepatic differentiation of adipose-derived mesenchymal stem cells.

Objective:To understand the gene characteristics of Sapovirus from diarrhea cases in diarrhoeal disease clinics in Beijing.Methods:In 2019, stool samples were collected from diarrhea cases in diarrhoeal disease clinics in Beijing. The samples were used for the detection of nucleic acid of Sapovirus with real-time RT-PCR. Different RT-PCR methods were used for the partial gene segment amplification in the capsid protein VP1 region and the polymerase RdRp region, and sequencing was conducted for amplified positive products. The sequences were aligned with software BioEdit 7.0.9.0 and analyzed with software Mega 6.06.Results:The overall detection rate of Sapovirus was 2.89% (44/1 522), the detection rate in children under 5 years old was 3.34% (18/539) and 2.64% (26/983) in children aged ≥5 years. The capsid protein VP1 region was sequenced in 23 strains belonging to 8 genotypes (GⅠ.2 had 6 strains, GⅠ.1 and GⅡ.3 had 5 strains, respectively, GⅠ.3 and GⅡ.5 had 2 strains, respectively, GⅠ.5, GⅡ.1 and GⅣ.1 had 1 strain, respectively). A total of 16 strains were detected in the cases aged ≥5 years, and the proportion of GⅠ.2 was highest (37.50%, 6/16), and 7 strains were detected in the cases under 5 years old, the proportions of GⅠ.1 and GⅡ.3 were highest (both 42.86%, 3/7); The internal similarity of each genotype was 95.5%-100.0%, and the similarity with the 51 reference strains of human or sewage sources in different years and different countries was 92.2%-100.0%. The polymerase RdRp region was sequenced in 25 strains belonging to 8 genotypes (GⅡ.P3 had 9 strains, GⅠ.P3 had 4 strains, GⅠ.P1, GⅠ.P2 and GⅡ.P1 had 3 strains, respectively, GⅠ.P5, GⅡ.P5 and GⅣ.P1 had 1 strain, respectively). Fifteen strains were detected in the cases aged ≥5 years, and GⅡ.P3 had the highest proportion (40.00%, 6/15). Ten strains were detected in the cases under 5 years old, and the proportions of GⅠ. P1, GⅡ.P1 and GⅡ.P3 were highest (all 30.00%, 3/10); The internal similarity of each genotype was 94.0%-100.0%, and the similarity with the 39 reference strains of human or sewage sources in different years and different countries was 90.2%-99.1%.Conclusions:Sapovirus is one of the pathogens among diarrhea cases in Beijing. The main genome is GⅠ and GⅡ, and the genotypes are diverse and dispersed. The main genotypes of diarrhea cases in people aged ≥5 years and less than 5 years are different.

Objective:To analyze the genomic characteristics and variations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) derived from an outbreak in inbound flight in Aug, 2022 in Beijing, and provide reference data for disease prevention and control and risk assessment.Methods:Fifty respiratory tract specimens from all cases in this outbreak were collected. The digital PCR (ddPCR) was used to determine the viral loads of the specimens. The full genome of the viruses were sequenced by Next-generation sequencing. Then analuses were performed on the genetic identity, variations and phylogenesis.Results:The median of viral loads in all 50 samples were 5.57×10 4 copies/ml and 5.85×10 4 copies/ml, for ORF1ab gene and N gene, respectively. A total of 46 SARS-CoV-2 genomes were obtained, which all belonged to Omicron/BA.5. Two genome clusters were observed, involving 21 and 7 cases, with a nucleotide sequence identities of 99.993% and 99.997%, respectively. Conclusions:The studied outbreak was composed of two main clusters and other individual cases with Omicron/BA.5 virus overseas.

Objective:To explore the key genes related to the development, progression and prognosis of acute myeloid leukemia (AML) based on bioinformatics, and to analyze their functions.Methods:The chip expression profile GSE84881 data set of AML patients including 19 AML samples and 4 normal tissue samples was downloaded from the gene expression omnibus (GEO) database. GEO online tool GEO2R was used to screen the differentially expressed genes (DEG). The DAVID online database was used to make gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis of DEG. The STRING online database was used to analyze the protein interaction (PPI) network of DEG, and the key genes were screened by using the Cytoscape software. The weighted gene co-expression network analysis (WGCNA) was used to build co-expressed network and obtain the central genes.LC-Bio online platform was used to construct Venn diagram and the key genes and central genes in PPI were crossed to finally obtain the true key genes. RNA-seq datasets GSE2191 and GSE90062 of human tissues were downloaded from GEO database to verify the screened key genes. Kaplan-Meier method was used to analyze the effects of key genes on the overall survival (OS) of AML based on the data of GEPIA database.Results:A total of 247 DEG were identified in GSE84881 data set, including 112 up-regulated genes and 135 down-regulated genes. According to the results of GO enrichment analysis, 247 DEG were mainly enriched in the regulation of signal transduction and cell proliferation in the biological process (BP); the cell composition (CC) revealed that these genes were mainly involved in the cytoplasm and exosomes; the molecular function (MF) analysis showed that these genes were mainly enriched in protein binding and calcium binding. Further KEGG pathway enrichment analysis showed that these 247 DEG were mainly involved in NOD-like receptor signal pathway and interleukin 17 (IL-17) signal pathway. And then the 12 key genes were obtained from PPI. WGCNA software was used to screen 13 central genes from GSE84881 dataset and finally 1 real key gene EGF was obtained after taking intersection. Kaplan-Meier method showed that OS time of AML patients in EGF high expression group was decreased than that in EGF low expression group, and the difference was statistically significant( P = 0.044). Conclusions:EGF may be an important diagnosis and treatment target of AML and may become a potential biomarker for clinical treatment and prognosis prediction of AML.

Acute myeloid leukemia (AML) is a group of highly-heterogeneous clonal diseases. Chemotherapy and hematopoietic stem cell transplantation are considered as effective treatment for AML. For high-risk AML patients, allogeneic hematopoietic stem cell transplantation is an effective therapeutic option. However, some AML patients may still face the problem of disease recurrence after hematopoietic stem cell transplantation. A majority of recurrent patients cannot be effectively treated by chemotherapy or secondary transplantation, which is the main cause of death after allogeneic hematopoietic stem cell transplantation. Therefore, it is of significance to strengthen follow-up of AML patients after allogeneic hematopoietic stem cell transplantation and implement appropriate measures to prevent postoperative recurrence. In this article, the monitoring, drug prevention and cell therapy of recurrence after allogeneic hematopoietic stem cell transplantation in high-risk AML patients were reviewed, aiming to provide reference for improving clinical prognosis of high-risk AML patients undergoing allogeneic hematopoietic stem cell transplantation.

Objective:To investigate the phylogenetic and antigenic characteristics of hemagglutinin (HA) gene of influenza B/Victoria lineage (BV) viruses in Beijing during the 2021-2022 influenza surveillance season, and to analyze whether the circulating BV viruses match the vaccine strain.Methods:Pharyngeal swab specimens from influenza like-illness (ILI) cases in the 2021-2022 influenza surveillance season were collected from surveillance network labs in Beijing and cultured in MDCK cells and chicken embryo to isolate BV viruses. Nucleic acids of the viruses were extracted, and the HA gene was amplified and sequenced. The nucleotide and amino acid sequence identity of the HA gene was analyzed using MEGA5.0 software. A phylogenetic tree of HA gene was constructed using the maximum likelihood method. The N-glycosylation sites in HA were predicted online. Three-dimensional structure of HA was constructed using SWISS-MODEL homologous modeling. Hemagglutination inhibition (HI) test was performed to analyze the antigenicity of BV viruses.Results:A total of 402 BV viruses were collected and 58 strains with full-length HA gene sequences were chosen for further analysis. Compared with the HA gene of this year′s vaccine strain (B/Washington/02/2019), there were 27 amino acid mutations, 11 of which were located in four different antigenic determinants. The phylogenetic analysis revealed that three subgroups of 1A.3, 1A.3a1, and 1A.3a2 co-circulated in Beijing with 54 strains (54/58, 93.10%) clustered to the Clade 1A.3a2, two strains (2/58, 3.45%) clustered to the Clade 1A.3a1, and two strains (2/58, 3.45%) in the same subgroup (Clade 1A.3) as the vaccine component BV strain in 2021-2022. Compared with the vaccine strain (B/Washington/02/2019), two BV strains had an additional N-glycosylation site at residue 197, while the other 56 strains showed no change in N-glycosylation sites. Antigenic analysis showed that 35 BV strains (35/58, 60.34%) were antigenically similar to the vaccine strain and 23 strains (23/58, 39.66%) were low-response strains.Conclusions:Three subgroups of BV viruses co-circulated in Beijing during the 2021-2022 influenza surveillance season. The predominant subgroup was Clade 1A.3a2 (93.10%), showing a certain genetic distance with the vaccine strain (B/Washington/02/2019). Nearly 40% (39.66%) of the viruses were low-response strains. This study indicated that continuous monitoring of the variations of influenza epidemic strains and timely providing laboratory basis for screening vaccine component strains were the basic technical guarantee for coping with influenza pandemic.

With characteristics of high infectivity, diverse transmission routes and high variation, norovirus is the main pathogen of sporadic cases and outbreaks of acute gastroenteritis, resulting in a serious disease burden. This paper summarizes the latest progress in epidemiological research of norovirus infection from aspects of disease burden caused by acute gastroenteritis, virus variation and predominant strains, prevention and control measures, and immunization and vaccine development

Objective:To analyze the performance of emergency response to 2019 novel coronavirus (2019-nCoV) positive cases in an international test competition in an Winter Olympic Game venue and provide evidences for the COVID-19 prevention and control in similar competitions.Methods:A retrospective analysis on the epidemiological investigation and nucleic acid test results of the cases, the implementation of prevention and control measures, including the communication with sport teams and others, was conducted.Results:The positive cases of 2019-nCoV among entering people were detected before entry, at airport, hotel and venue. Two positive cases were reported before entry, 2 positive cases infected previously and 3 asymptomatic cases were reported after the entry. The venue public health team and local CDC conducted epidemiological investigation and contact assessment jointly in a timely and efficient manner. No local secondary transmission occurred, but the nucleic acid test results of positive persons fluctuated, posing serious challenges to the implementation of prevention and control measures.Conclusion:In large scale international competition, there is high risk of imported COVID-19. It is necessary to fully consider the fluctuation of nucleic acid test results, the criteria for determination and cancellation of positive results and give warm care to positive cases in the emergency response.