Packaging of Rift Valley fever virus pseudoviruses and establishment of a neutralization assay method

Rift Valley fever (RVF) is an acute, febrile zoonotic disease that is caused by the RVF virus (RVFV). RVF is mainly prevalent on the Arabian Peninsula, the African continent, and several islands in the Indian Ocean near southeast Africa. RVFV has been classified by the World Organisation for Animal Health (OIE) as a category A pathogen. To avoid biological safety concerns associated with use of the pathogen in RVFV neutralization assays, the present study investigated and established an RVFV pseudovirus-based neutralization assay. This study used the human immunodeficiency virus (HIV) lentiviral packaging system and RVFV structural proteins to successfully construct RVFV pseudoviruses. Electron microscopy observation and western blotting indicated that the size, structure, and shape of the packaged pseudoviruses were notably similar to those of HIV lentiviral vectors. Infection inhibition assay results showed that an antibody against RVFV inhibited the infective ability of the RVFV pseudoviruses, and an antibody neutralization assay for RVFV detection was then established. This study has successfully established a neutralization assay based on RVFV pseudoviruses and demonstrated that this method can be used to effectively evaluate antibody neutralization.

Osteoblast-derived IL-7 Prohibits Bone Formation through Activating mTORC1 Signaling / 医学研究杂志

Objective To investigate the regulation of bone formation by osteoblast-derived interleukin-7 (IL-7) trough the mammalian target of rapamycin (mTOR) signaling pathway.Methods The lentiviral vector with encoding frame of IL-7 gene was transfected into mouse MC3T3-E1 osteoblasts,and the expression levels of IL-7 mRNA and protein were detected,respectively,by qRT-PCR and ELISA method.Western blot method was used to detect the expression levels of P-S6,S6,collagen Ⅰ (Col Ⅰ) and Osteocalcin (Ocn) in MC3T3-E1 cells and in MC3T3-E1 cells stimulated by 0.1nmol/L mTORC1-specific inhibitor rapamycin.Results The IL-7 mRNA level of MC3T3-E1 cells transfected with upregulated 4.6 times,and ELISA assay showed an increase of 3.9 times of IL-7 level in osteoblastic supernatants.After transfected using lentiviral vector with encoding frame of IL-7 gene,the expression levels of P-S6 protein increased significantly,while the expression levels of Col Ⅰ and Ocn protein decreased significantly.However,rapamycin treatment of over-expressed-IL-7 MC3T3-E1 cells resulted in a decline of P-S6 protein levels,but an increase of Col Ⅰ and Ocn protein levels.Conclusion Osteoblast-derived IL-7 may inhibit its maturation by promoting mTORC1 signaling pathway.

Acetabular liner wear of cross-linked versus conventional polyethylene for total hip arthroplasty:a meta-analysis / 中国组织工程研究

BACKGROUND: Aseptic loosening occurs after long-term total hip replacement, which directly affects the service life and prospective efficacy of artificial joints. The particles produced by artificial joint wear lead to the surrounding bone dissolved, further cause loosening, among which, polyethylene particles because of acetabular liner wear stand out. OBJECTIVE: To systematically assess the acetabular liner wear, loosening and osteolysis caused by cross-linked polyethylene or conventional polyethylene after total hip arthroplasty. METHODS: A computer-based research of Medline, EMbase, CBM, CNKI, CqVip, WanFang databases before December 2015 and Cochrane (3rd issue, 2011) was performed in accordance with the retrieval strategy made by Cochrane collaboration. A manual retrieval of related bone journals and conference papers was conducted. Eleven randomized controlled trials about the wear caused by cross-linked polyethylene or conventional polyethylene after total hip arthroplasty were enrolled based on inclusion criteria, followed by a Meta-analysis using RevMan 5.0 software. RESULTS AND CONCLUSION: (1) Eleven randomized controlled trials involving 952 patients were included. (2) Meta-analysis showed that the acetabular liner wear rate of cross-linked polyethylene was significantly lower than that of conventional polyethylene at 5 years postoperatively [MD=-0.07, CI(-0.09, -0.05), I2=93%, P < 0.00001]; the large heterogeneity was decreased [MD=-0.06, 95%CI (-0.07, -0.04), I2=39%, P < 0.00001] after three research removed through sensitivity analysis. (3) The osteolysis rate in the cross-linked polyethylene group was significantly lower than that in the conventional polyethylene group [RR=0.39, 95%CI (0.27, 0.57), I2=0%, P < 0.00001]. (4) These results suggest that the cross-linked polyethylene liners exhibit reduced radiological wear and osteolysis, but the mean follow-up of 5 years (1.8 to 8.0) cannot meet the long-term requirements. Therefore, multi-central, large sample size and high-quality randomized controlled trials are needed to testify the efficacy and safety of cross-linked polyethylene.BACKGROUND: Aseptic loosening occurs after long-term total hip replacement, which directly affects the service life and prospective efficacy of artificial joints. The particles produced by artificial joint wear lead to the surrounding bone dissolved, further cause loosening, among which, polyethylene particles because of acetabular liner wear stand out. OBJECTIVE: To systematically assess the acetabular liner wear, loosening and osteolysis caused by cross-linked polyethylene or conventional polyethylene after total hip arthroplasty. METHODS: A computer-based research of Medline, EMbase, CBM, CNKI, CqVip, WanFang databases before December 2015 and Cochrane (3rd issue, 2011) was performed in accordance with the retrieval strategy made by Cochrane collaboration. A manual retrieval of related bone journals and conference papers was conducted. Eleven randomized controlled trials about the wear caused by cross-linked polyethylene or conventional polyethylene after total hip arthroplasty were enrolled based on inclusion criteria, followed by a Meta-analysis using RevMan 5.0 software. RESULTS AND CONCLUSION: (1) Eleven randomized controlled trials involving 952 patients were included. (2) Meta-analysis showed that the acetabular liner wear rate of cross-linked polyethylene was significantly lower than that of conventional polyethylene at 5 years postoperatively [MD=-0.07, CI(-0.09, -0.05), I2=93%, P < 0.00001]; the large heterogeneity was decreased [MD=-0.06, 95%CI (-0.07, -0.04), I2=39%, P < 0.00001] after three research removed through sensitivity analysis. (3) The osteolysis rate in the cross-linked polyethylene group was significantly lower than that in the conventional polyethylene group [RR=0.39, 95%CI (0.27, 0.57), I2=0%, P < 0.00001]. (4) These results suggest that the cross-linked polyethylene liners exhibit reduced radiological wear and osteolysis, but the mean follow-up of 5 years (1.8 to 8.0) cannot meet the long-term requirements. Therefore, multi-central, large sample size and high-quality randomized controlled trials are needed to testify the efficacy and safety of cross-linked polyethylene.

One-stage total hip arthroplastyversusfemoral head arthroplasty for elderly femoral neck fractures：a meta-analysis of hip function and complications / 中国组织工程研究

BACKGROUND:There are objections to the efficacy and safety of total hip arthroplasty and artificial femoral head arthroplasty in the treatment of femoral neck fracture. OBJECTIVE:To assess the efficacy and safety of one-stage total hip arthroplasty and femoral head arthroplasty for > 60-year-old patients with femoral neck fractures. METHODS:According to the search strategy of Cochrane colaboration network, we searched PubMed (1966 to December 2014), EMbase (1974 to December 2014), Cochrane Library (Issue 3, 2011), China Biology Medicine database(1978 to December 2014), China National Knowledge Infrastructure (1994 to December 2014), VIP database (1989 to December 2014), and Wanfang Database (1979 to December 2014). Twenty-one articles on total hip arthroplasty and hemiarthroplasty for elderly femoral neck fractures were included. Two reviewers independently evaluated the quality of the included studies and extracted the data. In case of disagreement, settlement was made by negotiation. Meta-analysis was performed by RevMan 5.0 software in the included studies. RESULTS AND CONCLUSION:(1) Literature analysis: five randomized controled studies, three quasi-randomized controled studies, and thirteen retrospective cohort studies were included, containing 2 250 patients. (2) Meta-analysis: No significant differencein rate of dislocation, deep infection rate and mortality rate in 1 year after replacement was detected between total hip arthroplasty and hemiarthroplasty for elderly femoral neck fractures (dislocation rate:RR=1.38, 95%CI: 0.81-2.34; deep infection rate RR=1.12, 95%CI: 0.60-2.11; mortality rateRR=0.90, 95%CI: 0.69-1.18). Reoperation rate was higher in the hemiarthroplasty group than in the total hip arthroplasty group (RR=0.46, 95%CI: 0.32-0.66). Harris score on the affected side between1 and 4 years was significantly higher in the total hip arthroplasty group than in the hemiarthroplasty group (MD=5.64, 95%CI: 2.82-8.46). (3) Results suggested that if physical conditions permit, compared with hemiarthroplasty group, femoral neck fractures patients aged > 60 years old in the total hip arthroplasty group had better hip function, but no significant difference was found in dislocation, deep infection and mortality between both groups.

Preparation and application of a colloidal gold strip to detect the rabies antibody / 生物工程学报

To develop a specific, rapid, and convenient immunochromatography assay (ICA) to detect the rabies antibody in clinical sample from immuned dogs by rabies vaccine. Colloidal gold particles labeled with purified rabies virus (CVS11) were used as the detector reagent. The staphylococcal protein A (SPA) and pured rabbit anti-rabies virus IgG were blotted on the test and control regions of nitrocellulose membrane. Then the strip was assembled with sample pad, absorbing pad, and dorsal shield. The assay samples (261 dog's serum) were collected from Wildlife Rabies Disease Diagnostic Laboratories of Ministry of Agriculture in China, Institute of Military Veterinary, Academy of Military Medical Sciences and other six provinces, including rabies virus positive and negative serum. The performance of the strip was compared to fluorescent antibody virus neutralization test. The neutralizing antibody titer could be detected above 0.5 IU. The strip did not change of performance when stored at room temperature for 12 months. It may offer reference of neutralizing antibody titer level after dogs immuned rabies vaccine and determin whether the dogs need to be immuned again.

Recent advances in enzyme assays using fluoremetry / 生物工程学报

Enzymes play such a pivotal role in cellular metabolism that enzyme assays are important for bio-engineering, disease diagnoses and drug discovery. Among the reported methods, fluoremetry has attracted more and more attention due to its high sensitivity and possibility of continuous dynamic monitoring. The recent progresses and applications in enzyme assays using fluorescent probes were reviewed. Different methods were classified into direct fluorescence detection and indirect fluorescence detection according to their labeled substrates and detection mechanisms. Our writing purpose is to provide the readers with a flavor of the kinds of tools and strategies available in enzyme assays with fluorescent probes. Also, the research situation and prospects were disucssed

Effect of ?-rays on the histomorphology and hydroxyproline content of human tendon / 中国矫形外科杂志

[Objective]To study the changes of the histomorphology and content of hydroxyproline that irradiated by 2.87 Mrad ?-rays in human tendon. [Methods]Forty fresh human tendons were freezed in-80℃ for six weeks,and randomly divided into two groups: the experimental group(group A) and control group(group B).Group A stored in dry ice was exposed to ?-rays until the absorbed dose reached 2.87 Mrad.The tendons was stained with HE and VG methods,and then observed by common light microscope and transmission electron microscope respectively.The content of hydroproline in tendon collagen hydrolysate was determined by the high performance liquid chromatography with precolumn derivation.[Results]①The results of histomorphology observation revealed that compared to the control group,the gaps between collagen fiber bands in irradiation group were enlarged,incompact,disordered and some of them fractured.The electron microscope observation showed that the transverse striation of the collagen fibers became unclear or disappeared.The membrane of tendon cell was dissolved,the cell nuclear was disintegrated and the organelles was reduced.②The content of hydroxyproline in the collagen hydrolysate of irradiation group was significantly higher than that in non-irradiation group under the same hydrolysis condition(P

Study on viability of Cistanche deserticola seeds / 中草药

Objective To improve the 2,3,5-triphenyl tetrazolium chloride (TTC) solution method for measuring the viability of Cistanche deserticola seeds and investigate the change in viability during storage at 5 ℃. Methods The effect of the testa,TTC concentration,sodium hypochlorite concentration (NaClO),and staining time were studied,and seed viability during storage at 5 ℃ was measured with the improved method. Results Seeds were kept for 48 h in 0.5% TTC solution at 40 ℃,and then for 2 h in 0.2% NaClO solution;Seed viability was measured under a stereomicroscope. Storing seeds of C. deserticola for 1 to 2 years at 5 ℃ had no significant effects on their viability. However,the percentage of seeds with high viability was increased with the extension of the storage time at 5 ℃. Conclusion A convenient and rapid method for measuring the viability of C. deserticola seeds is developed. Storing C. deserticola seeds at 5 ℃ could improve their viability