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Objective To construct a recombinant poxvirus vector vaccine, rVTTδTK-RBD, and to evaluate its safety and immunogenicity. Methods The receptor-binding domain (RBD) gene was synthesized with reference to the gene sequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was inserted into the polyclonal site of the self-constructed recombinant plasmid pSTKE, to construct the recombinant poxvirus shuttle vector pSTKE-RBD. This was then transfected into BHK-21 cells pre-infected with the vaccinia virus Tiantan strain (VTT). The recombinant poxvirus rVTTδTK-RBD was successfully obtained after several rounds of fluorescence phage screening. The effect of rVTTδTK-RBD on the body mass of BALB/c mice was detected after immunizing mice by intra-nasal vaccination. The levels of specific and neutralizing antibodies produced by rVTTδTK-RBD on BALB/c mice were analyzed after immunizing mice intramuscularly. The effect of rVTTδTK-RBD on T cell subsets in BALB/c mice was detected by flow cytometry. Results Through homologous recombination, enhanced green fluorescent protein (EGFP) screening marker, and multiple rounds of fluorescent phosphorescence phage screening, a recombinant poxvirus rVTTδTK-RBD, expressing RBD with deletions in the thymidine kinase (TK) gene, was successfully obtained, which was validated by PCR. The in vivo experiments on BALB/c mice showed that rVTTδTK-RBD was highly immunogenic against SARS-CoV-2 and significantly reduced toxicity to the body compared to the parental strain VTT. Conclusion The recombinant poxvirus vaccine rVTTδTK-RBD against SARS-CoV-2 is successfully constructed and obtained, with its safety and immunogenicity confirmed through various experiments.
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Animals , Mice , SARS-CoV-2/genetics , COVID-19 , Vaccines, Synthetic/genetics , Genes, Reporter , Bacteriophages , Mice, Inbred BALB CABSTRACT
Objective:To investigate the adhesion of polydopamine-modified collagen membrane composites to cartilage tissues and the effect on chondrocyte proliferation, and further explore the possibility of their application in autologous chondrocyte transplantation.Methods:Porous collagen membranes were prepared, and the polydopamine-modified collagen membrane composites were constructed by the adsorption method. The physical and chemical properties and structural characteristics of the membranes, such as thermal stability, thermal properties, porous structure, and surface element composition, were characterized by infrared spectroscopy, thermogravimetric analysis, differential thermal analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy, respectively. The adhesion between the polydopamine-modified collagen membrane and fresh cartilage tissue was tested by a mechanical testing machine. The effects of the membranes on the adhesion and proliferation of rabbit chondrocytes were investigated by in vitro cell culture.Results:The structure and surface element composition of the membranes altered with the increase in the adsorption time of polydopamine, and the capacity of polydopamine increased with the increase in the adsorption time. The thermal stability and thermal properties of collagen membrane materials were not significantly affected by the adsorption of polydopamine. The adhesion of the membrane to cartilage tissue increased with the increase in the amount of absorbed polydopamine. The membranes showed a time-dependent promoting effect on the proliferation of the chondrocytes.Conclusions:The polydopamine-modified collagen membrane has potential application in articular cartilage repair, but more research is required to optimize the membrane before it is used in articular cartilage repair.
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Health management is the process of comprehensive management for health risk factors of individuals or groups. The general practice concept when used in health management of the medical examination centers, can optimize the medical examination process and facilitate health guidance. The Health Management Center of the Fourth Affiliated Hospital of Zhejiang University School of Medicine applied such concept in its management, and found increased number of persons taking medical examinations, decreased rate of complaints, and decreases in both waiting days and registration fees by outpatients with positive medical examination outcomes. In addition, general practitioners guided the majority of people undergoing medical examinations with health prescriptions, and improved the quality of health management.
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Objective To evaluate the effect of " elite small class" training mode in capacity building for general practitioners in Yiwu city. Methods The Fourth Affiliated Hospital of Zhejiang University School of Medicine worked with Yiwu Health Bureau, and held the first training class for general practitioners from December 6th in 2018 to April 5th in 2019.The mode of " elite small-class" was adopted. Theoretical assessment was carried out for trainees before and after the training and discussion was conducted after the training. Descriptive analysis of quantitative data and thematic analysis of qualitative data were carried out. Results The trainees′theoretical performance had been significantly improved after 4 months of theoretical learning and clinical rotation.The average score of the theoretical performance was increased from 66.94 to 72.59. Conclusions It was preliminarily found that the " elite small-class" training mode was suitable for the training of general practitioners in rural areas.Government support and trainee selection are key to training outcomes.
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Objective To evaluate the role of Toll-like receptor 4 ( TLR4)/nuclear factor kappa B ( NF-κB) signaling pathway in the development of postoperative chronic pain and the relationship with ex-pression of voltage-gated sodium channel 1. 7 (Nav 1. 7) in the dorsal root ganglion (DRG) of rats. Meth-ods Thirty-six clean-grade healthy male Sprague-Dawley rats, aged 9-11 weeks, weighing 200-250 g, were divided into 3 groups ( n=12 each) using a random number table method: control group ( group C) , normal saline group ( group NS) and TLR4 antagonist LPS-RS group ( group R) . Postoperative chronic pain was produced by skin/muscle incision and retraction (SMIR). From 1 day before SMIR to 10 days after SMIR, NS group received continuous intrathecal injection of normal saline 10μl, while R group received continuous intrathecal injection of LPS-RS 20μg/10μl. Six rats were randomly selected in each group, and the mechanical pain threshold was measured at 1 day before SMIR and 1, 5, 10, 15 and 20 days after SMIR. The 6 rats left in each group were sacrificed at day 10 after SMIR, and the DRGs of the lumbar seg-ment (L4,5) were removed for determination of the expression of phosphorylated NF-κB (p-NF-κB) and Nav 1. 7. Results Compared with group C, the mechanical pain threshold was significantly decreased at 5-20 days after SMIR, and the expression of p-NF-κB and Nav1. 7 was up-regulated at 10 days after SMIR in group NS ( P＜0. 01) . Compared with group NA, the mechanical pain threshold was significantly increased at 5-20 days after SMIR, and the expression of p-NF-κB and Nav 1. 7 was down-regulated at 10 days after SMIR in group R (P＜0. 01). Conclusion Up-regulated expression of Nav1. 7 in DRGs after activating TLR4/NF-κB signaling pathway is involved in the development of postoperative chronic pain in rats.
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Objective To investigate the drinking status and associated factors in adults in China.Methods Based on the 2010-2012 China National Nutrition and Health Survey (CNNHS),a total of 135 824 participants aged ≥18 were included in this cross-sectional analysis.Multivariable logistic regression model was used to investigate the associated factors for drinking status.Results The overall drinking rate was 30.5％ in Chinese adults,53.8％ in men,and 12.2％ in women.The excessive drinking rate was 14.0％ in men and 1.1％ in women.The daily drinking rate was 25.7％ in men and 10.9％ in women.Men mainly consumed multi-type wines,but women preferred beer.The overall harmful drinking rate was 7.1％.The excessive drinking rate,daily drinking rate,and harmful drinking rate increased first but then declined with age.All the four rates were positively related with physical activity.Conclusions The drinking rate,excessive drinking rate,daily drinking rate and harmful drinking rate were high in adults in China.Drinking status was associated with age,sex,marital status,education level,smoking status and physical activity.
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Objective To investigate the drinking status and associated factors in adults in China.Methods Based on the 2010-2012 China National Nutrition and Health Survey (CNNHS),a total of 135 824 participants aged ≥18 were included in this cross-sectional analysis.Multivariable logistic regression model was used to investigate the associated factors for drinking status.Results The overall drinking rate was 30.5％ in Chinese adults,53.8％ in men,and 12.2％ in women.The excessive drinking rate was 14.0％ in men and 1.1％ in women.The daily drinking rate was 25.7％ in men and 10.9％ in women.Men mainly consumed multi-type wines,but women preferred beer.The overall harmful drinking rate was 7.1％.The excessive drinking rate,daily drinking rate,and harmful drinking rate increased first but then declined with age.All the four rates were positively related with physical activity.Conclusions The drinking rate,excessive drinking rate,daily drinking rate and harmful drinking rate were high in adults in China.Drinking status was associated with age,sex,marital status,education level,smoking status and physical activity.
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Polycythemia vera (PV) is a chronic clonal myeloproliferative disorder of hematopoietic stem cell characterized by a pronounced symptom burden, including fatigue, pruritus, and symptomatic splenomegaly, along with an increased risk of thrombosis and the potential for evolution to myelofibrosis (MF) and secondary acute myeloid leukemia. Research on pathogenesis, diagnosis and treatment of PV has made a great progress since the discovery of JAK2 V617F mutation in 2005. The change of epigenetics plays an important role in the progression of PV, and the drugs for apparent genetic alteration may improve the life quality of PV patients.