BACKGROUND:Industrialization of new-born bovine serum and abundant resource of bovine lendon enable industrialization of medical collagen sponge.OBJECTIVE:To prepare collagen sponge with new-born bovine tendons by inoculating Veto cells,primary embryo skin cell of Tianzhu White Yak and lamb testicle cell of Minxian black fur sheep of the tissue scaffold of collagen sponge.and observe the biocompatibility of collagen sponge with three different cells.DESIGN,TIME AND SETTING:Repetitive measurement was performed at the Key Laboratory of State Nationalities Afrairs Committee,College of Life Sciences and Engineering,Northwest University for Nationalities from February to May 2006.MATERIALS:Tendons of new-born bovine within 24 hours were digested by glacial acetic acid and pepsinum firstly and then salting-out,dialysis and vacum freeze drying were performed to prepare collagen sponge.f2 passage of embryo skin cells of Tianzhu Whit Yak and f2 passage of lamb testicle cells of Minxian black fur sheep were prepared by out laboratory;Vero cells were provided by Union Medical University.METHODS:In a 6-hole plate,the Vero cell,embryo skin cells of Tianzhu White Yak and lamb testicle cells of Minxian Black Fur Sheep were inoculated into the collagen sponge pretreated by ultraviolet and sterilized by ozone.and incubated in 5%CO2 at 37℃.In addition,cells only inoculated ia a culture plate served as control. MAIN OUTCOME MEASURES:Inverted phase contrast microscope was used to observe cell growth condition in the collagen sponge and 6-hole plate at 5,12,24 and 72 hours.In addition,Coomassie brilliant blue as well as HE staining were conducted at 11 days after culture to identify the culture.RESULTS:Five hours after inoculation,cell adherence and expansion was observed at the bottom of culture plate.and some of the cells showed division.On the surface of collagen sponge.a round cell arrangement was observed.After inoculation of 48-72 hours,monolayer was found at the bottom of the plate.On the 11th day of culture.Coomassie brilliant blue and HE staining of three kinds of cells showed there were lager amount of cells well grew in the holes of collagen sponge,and the collagen sponge turned to be eminent,transparent and tenacious.CONCLUSION:The collagen sponge made from new-born bovine tendons exhibit good biocompatibility with three kinds of cells from different animals and tissues,and can be served as culture seaffoId of skin cells,tenal ceils.and testicle cells.

BACKGROUND:It is confirmed that collagen sponge prepared from human tendon,bovine tendon,rat tail,pig skin and newborn bovine tendon have good cytocompatibility.OBJECTIVE:To extract collagen from newborn bovine skin,prepare the collagen sponge for biomedical application,and observe the biocompatibility and cytocompatibility of collagen sponge with lamb fibroblasts.DESIGN,TIME AND SETTING:Controlled study was performed in the Key Laboratory of Bioengineering of State Ethical Committee,Life Science and Engineering College,Northwest University for Nationalities from May 2006 to February 2007.MATERIALS:Newborn Galiba bovine within 24 hours and black fur lamb kidney fibroblasts were used.METHODS:Newborn bovine skin was harvested to prepare the collagen sponge with a series of procedures,including depilation,pepsin+glacial acetic acid,salting-out,dialysis and freeze drying.The obtained collagen sponge was inoculated with fibroblast suspension,which were divided into collagen sponge group,negative control group (saline) and positive control group (rubber bung leaching liquor).MAIN OUTCOME MEASURES:Inverted phase contrast microscope and JVC digital camera system were used to observe the cell morphology and growth.Acridine orange dyeing was used to observe the proliferation of cell in collagen sponge at 20 and 35 days of culture.Hematoxylin-eosin staining was used to observe the growth of cells in collagen sponge at 65 days of culture.RESULTS:The cells of positive control group were not adhesive and all died three days later.Those of collagen sponge group and negative control group were normal and adhesive.With the prolong of culture time,the sponge pore decreased gradually,sponge appearance became eminent and transparent,the cell increased in number but decreased in morphology.Acridine orange dyeing at 20 and 35 days of culture showed that a large amount of cells appeared in the co-culture of collagen sponge with lamb kidney fibroblast,and pack of cell clumps grew.Abundant blue nuclei and newborn red collagen fiber were found by hematoxylin-eosin staining.CONCLUSION:The collagen sponge from newborn bovine skin has a good biocompatibility with lamb kidney fibroblast cell of black fur,and no cytotoxicity appears.

Objective To analyze the spatiotemporal characteristics of the clustered epidemics of common infectious diseases in primary and secondary schools and kindergartens in Hongshan District, Wuhan from 2015 to 2022, and to provide a basis for scientific development of control measures. Methods Descriptive epidemiological methods were used to describe events. Mean center method and standard ellipse method were used to reflect the overall distribution characteristics of the events, and hot spot analysis and nuclear density analysis were used to explore and analyze the spatiotemporal characteristics of clustered epidemics at annual and seasonal scales. Results From 2015 to 2022, a total of 1563 clustered outbreaks of infectious diseases were reported in primary and secondary schools and kindergartens in Hongshan District of Wuhan. The top three clustered epidemic diseases were hand-mouth-foot disease (HFMD)/herpangina, influenza like cases, and varicella, respectively. Primary schools were prone to influenza like cases (76.00%), kindergartens were prone to HFMD/herpangina (92.06%), and primary schools and middle schools were prone to varicella (69.70% and 21.21% respectively). As the years grew, the clustered epidemics showed a trend of spreading towards the northeast and southwest direction. Compared with other places, Luonan Street and Hongshan Street had a higher incidence density of clustered epidemic events (21.81% and 15.86% respectively), which requires special attention. The areas with the highest nuclear density value in each season were mainly concentrated in the middle of Hongshan District. There were two clusters of HFMD/herpangina concentrated in Luonan Street, Liyuan and Heping Street, which was different from other diseases. Conclusion When deploying medical resources and epidemic prevention and control work in schools within the jurisdiction, more emphasis should be placed on key streets and places to achieve the best cost-effectiveness.

Objective:To investigate the effects of poly(A) tails with different lengths on mRNA expression in vitro and the passage stability of transcription template with poly (A) tail in Escherichia coli ( E. coli). Methods:Plasmids with poly(A) tails of 38, 60, 103, 125 and 126 (60 nt+ 6 nt spacer+ 60 nt) nt were designed and constructed. Then the plasmids were linearized by single enzyme digestion and used as transcription template for preparing enhanced green fluorescent protein (EGFP)-mRNA. EGFP-mRNA containing poly(A) tails of different lengths were transfected into 293T cells and the expression of EGFP was detected by flow cytometry. As to stability test, the template plasmids with poly (A) tail of 125 and 126 nt were transformed into E. coli TransStbl3 and Top10 competent cells. Seven clones were selected for culture and plasmid extraction, and then the plasmids were digested by restriction enzyme and detected by capillary electrophoresis. For passage stability, three correctly sequenced clones of each group were selected for continuous passage at 37℃, and the plasmids were extracted and digested every two generations for capillary electrophoresis. At the same time, the correctly sequenced clones of 125 nt group were also passaged at 30℃, and the plasmids were also extracted and digested every two generations for capillary electrophoresis. Results:The transcription templates with poly(A) tail of different lengths were successfully constructed. Flow cytometry showed that the fluorescence expression of the template plasmids with poly (A) tail of 103 and 125 nt were significantly higher than that of 38 and 60 nt. The fluorescence expression of the plasmid with poly (A) tail of 126 nt was significantly higher than that of all other groups. The percentages of stable sequences of the template plasmid with poly(A) tail of 125 nt in TransStbl3 and Top10 competent cells were 76% and 91%, respectively. The results of continuous passage showed that poly(A) tail of 125 nt could be stable to the 4th generation at 37℃ in both TransStbl3 and Top10 competent cells, and stable to the 16th and 10th generations at 30℃. The percentages of stable sequences of the template plasmid with poly(A) tail of 126 nt in TransStbl3 and Top10 competent cells were 95% and 48%, respectively. The results of continuous passage showed that poly(A) tail of 126 nt could be stable to the 12th generation at 37℃ in both TransStbl3 and Top10 competent cells.Conclusions:The length and composition of poly(A) tail in mRNA affected the expression of target protein. Adding a spacer with a length of 6 nt to poly(A) tail and low temperature culture were both helpful to improve the stability of the template plasmid, which provided a reference for the design and preparation of in vitro transcription template of mRNA vaccine.

Objective:To evaluate the immunogenicity of a quadrivalent subunit vaccine combined with RFH01 adjuvant in a mouse model.Methods:Identification tests were performed on four monovalent influenza virus subunit vaccine stock solutions according to the methods described in Part 3 of the Chinese Pharmacopoeia 2020 Edition. In the study of the quadrivalent subunit vaccine combined with RFH01 adjuvant, 460 female BALB/c mice (6-8 weeks old) were randomly divided into 46 groups including experimental groups, vaccine control group, negative control group and blank group with 10 mice in each group. In the study of the quadrivalent subunit vaccine in old and young mice, 80 female 10-month-old and 80 female 10-week-old BALB/c mice were randomly divided into 16 groups ( n=10) including monovalent influenza virus vaccine group, quadrivalent subunit vaccine group, quadrivalent subunit vaccine+ RFH01 adjuvant group, chicken embryo quadrivalent split vaccine control group and PBS group. All mice were immunized by intramuscular injection. At 21 d after the primary immunization, a booster immunization was conducted using the same strategy. Blood samples were collected at 21 d and 42 d after the primary immunization for serum separation. Haemagglutination inhibition (HI) test was performed to detect the antibody levels in mouse serum samples. Results:After the booster immunization, the positive conversion rates in all vaccine+ RFH01 adjuvant groups reached 100%, and the geometric mean titers (GMTs) of serum antibodies were significantly higher than those of the vaccine groups without RFH01 adjuvant. There were significant differences in serum antibody titers between the monovalent/quadrivalent subunit vaccine groups with and without RFH01 adjuvant. After the booster immunization, the titers of serum antibodies against H1N1, H3N2, B/Victoria and B/Yamagata in the 10-week-old mice were significantly higher than those in the 10-month-old mice.Conclusions:The monovalent and quadrivalent influenza virus vaccines in combination with RFH01 adjuvant could elicit higher antibody titers in young (6-10 weeks old) and old (10 months old) mice, showing good immunogenicity.

Objective To analyze the loss coefficient of bivalent live attenuated oral polio vaccine（bOPV) in Hongshan District, and understand the causes and influencing factors, and to provide a basis for scientifically formulating vaccine use plans and regulating vaccine management. Methods Using the data of Hubei Province Immunization Planning Information System and Hongshan District Vaccination Storage and Management System, a special questionnaire was designed to understand the vaccination and use of bOPV in various immunization units in Hongshan District. A descriptive statistical analysis method was used to calculate the loss coefficient. Results The bOPV loss coefficient of 25 vaccination units in Hongshan District was 1.69. The difference of the loss coefficient between the out-patient clinics of the District Health and Family Planning Committee（1.35）and the community clinics undertaken by large hospitals (2.01）was statistically significant. The difference of the loss coefficient between the inoculation once a week（1.57）and 2-6 times per week（1.94）was statistically significant. In terms of vaccine-disabled time, the two groups of <4 hours and >4 hours had different calculated loss coefficients 1.86 and 1.61, respectively, and the difference was statistically significant. Multivariate regression analysis of the factors related to the loss coefficients found that different outpatient attributes had a greater impact on the loss coefficient than the inoculation cycle and the number of inoculation stations. The loss coefficient for 2016 and 2017 was 2.09 and 1.75, respectively. The difference was statistically significant. Conclusion The management and use of live attenuated bivalent polio vaccine in Hongshan District was relatively standardized. The vaccine loss can by further reduced by strengthening supervision and assessment, setting up centralized vaccination and standardizing publicity and training.