The phospholipase A2 ( PLA2 ) is one of the main constituents of the bee venom. Its hypotensive effect and mechanism are studied in this report.In the anaesthetized rats and cats, the PLA2 of the bee venom given intravenously caused a quick and profound fall in the arterial blood pressure.The results of this study indicate that its hypotensive effect is mainly concerned with releasing the endogenous histamine. If the antagonists of H1 and H2 receptor are administered together, its hypotensive action will be countered.

Objective To establish a model of full-thickness avascular meniscal defect to assess outcome of bone-marrow mesenchymal stem cells (BMSCs) modified with human insulin-like growth factor Ⅰ (hIGF-Ⅰ) gene and compounded with injectable calcium alginate gel in repair of meniscal defect.Methods Models of full-thickness defect were created in the anterior comer of meniscus in goats,an area lacking of blood supply.The trial categorized the models to four groups:gene-ehanced tissue engineering (GETE) group (hIGF-Ⅰ transfected BMSCs were mixed with calcium alginate gel),BMSCs group (BMSCs were mixed with calcium alginate gel),empty group (calcium alginate gel was used alone) and control group (the defect was excluded from repair).Macroscopy was done at 4,8,and 16 weeks after operation.Variation of repair tissue was observed by light and scanning electric microscopy and aggrecan in repair tissue was determined as well.Results Meniscal defect was on the mend at 4-16 weeks after operation in GETE group,with the defect area being thoroughly filled with the white,elastic and tight repair tissue similar to normal meniscal tissue.Macroscopic examination showed a better result in GETE group than that in other groups.Light microscopy showed that repair tissue which was mainly fibrochondrocytes was arranged in line with calcium alginate fibers and that space between the fibers was mostly crammed with the matrix secreted by those cells.At the same time,those cells were tightly arranged and the matrix secreted by those cells was equally distributed according to light microscopy.Electroscopy demonstrated neat and tight arrangement of fibers and tight extracellular matrix in fiber space in GETE group.Aggrecan concentration in GETE group was relatively higher than in other groups,but still had difference from the normal meniscus.Conclusion hIGF-Ⅰ gene-transfected BMSCs combined with injectable calcium alginate gel can improve the effect in repair of full-thickness meniscal defect.

Objective To establish PKD2 gene recombinant lentivirus and to investigate its restorative effects on polycystin-2 and Wnt/β-catenin signaling pathways in Pkd2-null cell lines.Methods From August 2016 to February 2017,PKD2 gene was cleaved from the pcDNA3.1-TM-PKD2 plasmid and was inserted into the pLV-sfGFP 2A Puro by restriction enzymes Xba Ⅰ and Xho Ⅰ.The recombinant pLV-sfGFP-PKD2 plasmid was sequenced to verify a correct construction.Then we obtained recombinant lentiviruses by co-transfecting 293T cells with recombinant plasmid and packaging plasmids.B3/D3 (Pkd2 +/-) and B2/E8 (Pkd2-/-) cell lines were used to evaluate the effectiveness of lentivirus,they were divided into experimental group,control group,blank group and treated with pLV-sfGFP-PKD2 virus,pLV-sfGFP virus or culture media,respectively.The expression of PC2 was detected by Western blotting and immunofluorescence staining.Finally the cell proliferation was evaluated by detecting of proliferating cell nuclear antigen.The changes of Wnt/β-catenin signaling pathway were evaluated by real-time quantitative PCR.Results Enzyme digestion analysis and DNA sequencing showed that the recombinant plasmid pLV-sfGFP-PKD2 was constructed successfully.After infected with pLV-sfGFP-PKD2 virus,the expression of PC2 in the experimental group B2 and E8 cells(0.668 ±0.013,0.763 ±0.021) was restored to the normal level,compared with control group B3 and D3 cells,respectively (0.687 ± 0.015,P =0.164;0.776 ± 0.008,P =0.409).The proliferative activity in experimental group B2 cells(0.573 ±0.010) was significantly lower than that in control group B2 cells (0.848 ±0.031,P ＜0.01),and was returned to the level of blank group B3 cells (0.585 ±0.017,P =0.369).Reexpression of PKD2 in experimental group B2 cells also reduced the expression of Wnt7a,β-catenin,back to blank group B3 cells' level(0.037 ±0.005 vs.0.037 ±0.004,P=0.969;0.554 ±0.008 vs.0.571 ±0.013,P =0.64).Conclusions The recombinant pLV-sfGFP-PKD2 lentivirus has been constructed successfully.The lentivirus could rectify the absence of PC2 in PKD2-null cell lines,by which the hyperactivated Wnt/β-catenin signaling pathway and the abnormal cell proliferation caused by PC2 deficiency could be also restored to normal levels.

OBJECTIVE：To evaluate guidelines f or health technology assessment （HTA）at home and abroad ，and to provide reference for scientific formulation of HTA guidelines in China. METHODS ：Databases including PubMed ，Embase，Guidenlines International Network and 83 official websites from 26 countries governments and academic organizations were searched to collect HTA guidelines from inception to April 2020. Two reviewers independently screened literature and extracted data ，including basic characteristics， content of guideline and assessment content. Then a descriptive analysis was conducted. RESULTS & CONCLUSIONS：A total of 19 guidelines published during 2001 to 2018 were included ，7 guidelines（36.8％）were published in 2015-2020；in addition to 1 guideline from WHO ，14 guidelines （73.7％）were published in Europeand ，2 guidelines（10.5％） in North America and 1 guideline each from South America and Asia （5.3％）. There were 11 guidelines（57.9％）developed by academic organizations and 8 guidelines（42.1％）by health administration ；11 guidelines（57.9％）were evidence-based ，while the others weren ’t evidence- based （42.1％）. The purpose ，content and object of assessment are demonstrated in 19 guidelines；18 guidelines specified the assessment method （94.7％），and 16 guidelines（84.2％）defined the subject of assessment ；14 guidelines （73.7％）specified the HTA assessment process ；12 guidelines（63.3％）mentioned the conflict of interest in HTA assessment process；7 guidelines（36.8％）mentioned the application of assessment results. There are some differences in the formulation methods and contents of HTA guidelines in foreign countries ，but the core contents ar e basically the same. At present ，there is a lack of HTA guidelines in China. We can refer to foreign guidelines，and establish applicable HTA guidelines which aresuitable for national conditions ，so as to provide scientific guidance for HTA research.