In order to develop a double antibody sandwich assay (DAS-ELISA) for detecting bovine respiratory syncytial virus (BRSV),New Zealand white rabbits and BALB/c mice were immunized with the purified G protein as an antigen to prepare anti-G protein polyclonal and monoclonal antibodies.The antibody concentration and reaction conditions of DAS-ELISA were optimized by square titration,and its sensitivity,specificity,and coincidence rate were validated.Five hybridoma were stably secreting Mab which subclass belonged to IgG1κ.Western blot and IFA test showed that PcAb and Mab could react specifically with G protein and BRSV.The PcAb and Mab as the capture antibody and detection antibody respectively,and their optimal working concentrations were determined to be 2.5 μg/mL and 10μg/mL,the critical value 0.22 and the detection limit of 1.43 μg/mL,batch,inter-assay coefficient of variation less than 10 ％.The DAS-ELISA had no cross-reaction with several pathogens which often caused bovine respiratory disease.When 45 nasal swabs of clinical samples were simultaneously detected by the DAS-ELISA and RT-PCR,the sensitivity,specificity and coincidence rate were 92.0 ％,100 ％,95.6 ％,respectively.It' s indicated that the established DAS-ELISA detection method can be used to detect a large number of clinical samples.It was the foundation of monitoring and quick diagnosis for BRSV.

Objective To evaluate the role of programmed cell death ligand-1 (PD-L1) in a mouse model of bone cancer pain.Methods Ninety-six male C3H/HeN mice (20-25 g,4-6 weeks old),which inoculated with osteolytic NCTC 2472 cells,were used to build the model of bone cancer pain.Part one:sixtyfour male C3H/HeJ mice were randomly divided into sham group (group Sham,n =32) and tumor group (group Tumor,n=32).Part two:Twenty-four male C3H/HeJ mice which were inoculated with osteolytic NCTC 2472 cells were randomly divided into group T (tumor,n=8),group PD-L1 (intrathecal injection with PLX3397,1 μg/5μl,n=8) and group NS (intrathecal injection with normal saline,n=8).Also,there were eight male C3H/HeJ mice in group S which were intra-femur inoculated with α-MEM.The pain behaviors of Sham group and Tumor group were observed and the expression of PD-L1 was detected before inoculation and on 4,7,10,14 and 21 days after inoculation,including paw withdrawal mechanical threshold (PWMT) and the number of spontaneous flinches (NSF).On 14 d after inoculation,the mice of group PD-L1 and group NS were intrathecal injected with drugs respectively.Pain behaviors were observed before injection and 2,4,6,24h after injection.Results Compared with group Sham,PWMT was significantly decreased and NSF was increased on 7～ 21 d after inoculation in group Tumor (P＜0.05).Compared with baseline and group S (baseline (0.38±0.06),group Sham (0.35±0.08),(0.38±0.08),(0.36±0.07)),the expression of PDL1 was up-regulated on 10-21 d after inoculation in group Tumor ((0.77±0.06),(1.21±0.04),(1.18±0.06)) (P＜0.05).Compared with group NS,PWMT was significantly increased (group NS (0.25t0.12),(0.25±0.12),(0.31±0.12),group PD-L1 (1.43±0.49),(1.35±0.44),(0.95±0.26)),and NSF was decreased on 2-6 h after injection in group PD-L1 (group NS(11.74± 1.31),(13.78±0.0.91),(13.63±1.06),group P D-L1 (4.90± 0.82),(4.15± 0.71),(7.65±0.56)) (P＜0.05).Conclusion Expression of PD-L1 in spinal cord was up-regulated in the mouse model of bone cancer pain.Intrathecal injection of recombinant PD-L1 has an analgesic effect on mice with bone cancer.

Objective: To summarize the clinical experience of cardiopulmonary bypass(CPB) in acute type A aortic dissection received aortic arch reconstruction on age over 70 years patients. Methods: From April 2013 to December 2017, 35 elderly patients aged over 70 who were involved the aortic arch, brachiocephalic trunk, left common carotid artery and left subclavian artery and severe arch lesions, large false lumen and large rupture risk of acute A aortic dissection were reconstructed by triple-branched stent graft in emergency extracorporeal circulation. During the period of cardiopulmonary bypass, selective cerebral perfusion and discontinuous arrest under moderate hypothermia(25 degrees C) were used to reduce the time of cerebral ischemia and hypoxia, and to strengthen the management of the protection of important organs. Results: Cardiopulmonary bypass time was(144.85±32.98)minutes, and aortic cross clap time was(51.82±17.59)minutes, and selective cerebral perfusion time was(12.17±4.70)minutes, discontinuous arrest time was(4.50±3.54) minutes, the lower body arrest time was(16.6±7.49)minutes. All patients were smoothly weaned from cardiopulmonary bypass.35 patients resuscitated within 48 hours, of which 3 patients had transient mental disorders in the early stage and recovered before hospital discharge; 2 patients had cerebral infarction. Hospital mortality in this group was 17.1%(6/35). Conclusion Advanced age is not a contraindication to the reconstruction of the arch of the aortic dissection. Reasonable management of cardiopulmonary bypass can provide an important guarantee for the reconstruction of the elderly patients with acute type A aortic dissection.