In this study, we used a rat model of pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT) to investigate the role and mechanism of angiotensin (Ang)-(1-7) in regulating pulmonary artery diastolic function. Three weeks after subcutaneous injection of MCT or normal saline, the right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index (RVHI) of rats were detected using a right heart catheter. Vascular endothelium-dependent relaxation was evaluated by acetylcholine (ACh)-induced vasodilation. The relaxation function of vascular smooth muscle was evaluated by sodium nitroprusside (SNP)-induced vasodilation. Human pulmonary artery endothelial cells (HPAECs) were incubated with Ang-(1-7) to measure nitric oxide (NO) release levels. The results showed that compared with control rats, RVSP and RVHI were significantly increased in the MCT-PAH rats, and both ACh or SNP-induced vasodilation were worsened. Incubation of pulmonary artery of MCT-PAH rats with Ang-(1-7) (1 × 10^-9-1 × 10^-4 mol/L) caused significant vaso-relaxation. Pre-incubation of Ang-(1-7) in the pulmonary artery of MCT-PAH rats significantly improved ACh-induced endothelium-dependent relaxation, but had no significant effect on SNP-induced endothelium-independent relaxation. In addition, Ang-(1-7) treatment significantly increased NO levels in HPAECs. The Mas receptor antagonist A-779 inhibited the effects of Ang-(1-7) on endothelium-dependent relaxation and NO release from endothelial cells. The above results demonstrate that Ang-(1-7) promotes the release of NO from endothelial cells by activating Mas receptor, thereby improving the endothelium-dependent relaxation function of PAH pulmonary arteries.
Rats ; Humans ; Animals ; Vasodilation ; Pulmonary Arterial Hypertension ; Monocrotaline/toxicity* ; Rats, Sprague-Dawley ; Hypertension, Pulmonary/chemically induced* ; Endothelial Cells ; Pulmonary Artery ; Endothelium ; Acetylcholine/pharmacology* ; Nitroprusside/pharmacology*

Objective To establish the pushing transmission model of tendon-sheath system (TSS) for endoscopic flexible instrument, and study the key influencing factors of transmission efficiency. Methods The force and displacement transmission models of TSS in pushing configuration were built and simulated. The tendon-sheath transmission testing platform was designed to validate the model. The influencing factors, such as transmission velocity, tendon-sheath diameter ratio, curvature radius, were explored using this setup. Results There were obvious nonlinear phenomenon in force and displacement transmission. The model simulation results accorded quite well with the experiment results. Transmission velocity, tendon-sheath diameter ratio, curvature radius all had great effects on pushing force transmission of endoscopic flexible instrument, while they had a smaller effect on displacement transmission. Conclusions The proposed model can be used for calculating pushing force transmission of tendon-sheath system for endoscopic flexible instrument, so as to provide the doctors with force feedback at the tip of the end effector, and ensure the safe operation and improve the surgical effects. For better design and control of endoscopic flexible instrument, the transmission velocity, tendon-sheath diameter ratio, curvature radius must be comprehensively considered.

Objective: To learn the prevalence and drug resistance of nontuberculous mycobacteria ( NTM ) in Zhejiang Province, so as to provide evidence for NTM prevention and control. Methods: A total of 2 878 clinical mycobacterium isolates in Zhejiang Province were collected from the drug resistance surveillance in 2008-2009, 2013-2014 and 2018-2019, PNB/TCH growth tests were used to preliminarily identify the NTM in these mycobacterium-positive isolates. 16SrRNA, rpoB, ITS and hsp65 gene sequencing analysis were used to confirm strains initially identified as NTM. Proportional method was applied to detect drug susceptibility of NTM isolates. Results : Finally, 135 strains were confirmed as NTM and the isolation rate was 4.69%. The isolation rates of NTM in 2008-2009, 2013-2014 and 2018-2019 were 1.85%, 4.56% and 7.84%, respectively, with an increasing trend ( P<0.05 ). Thirteen species were identified and the top two species were M. intracellulare ( 82, 60.74% ) and M. kansassi ( 18, 13.33% ). The NTM isolates showed the highest drug resistance rate to isoniazid ( 97.78% ), followed by p-aminosalicylic acid ( 94.87% ) and streptomycin ( 94.81% ). Conclusions The isolation rates of NTM showed an upward trend in the drug resistance surveillance in 2008-2019,2013-2014 and 2018-2019 in Zhejiang Province. M. intracellulare and M. kansassi were the main strains isolated. The NTM isolates showed high resistance against both first and second-line antituberculosis drugs.

Objective To design a notched flexible articulation applied to electric stapler and study its turning performance. Methods The notched flexible articulation was designed and modeled. The kinematics and statics models of the articulation were established for simulation calculations. The stress, deflection angle, top displacement and driving force of the articulation with 3 different turning structures were studied under equal and variable stiffness of symmetrical notches by using finite element simulation. An experimental platform for performance test of the turning structure was built to verify the simulation results and the model. Results The theoretical model of the turning structure in bending process was basically consistent with the experimental results. With the optimization of symmetrical notch stiffness, the maximum stress of the articulation with variable stiffness was reduced by 20.64% and 39.20%, respectively. The articulation with variable stiffness required the smallest tensile force during bending, which was 33.41% lower than that of the articulation with equal stiffness, and the tip displacement (30.8 mm) along the bending plane was the smallest. The maximum deflection angle for the articulation with 3 different turning structures all could reach 90°. Conclusions The kinematics and statics models of the articulation can be used for the calculation of its tensile force and position changes. The turning performance of the articulation with variable stiffness using symmetrical notch is better than that with equal stiffness. The notched flexible articulation meets the design requirements and the turning needs of electric stapler.

To summarize professor
Acupuncture ; Acupuncture Points ; Acupuncture Therapy ; Facial Paralysis/therapy* ; Humans ; Needles

Objective To investigate the efficacy of Ilizarov technique in treatment of Gustilo type Ⅲ B and C of large tibia bone defect combined with soft tissue defect. Methods Thirty cases with large tibia bone defect combined with soft tissue defect in our hospital from January 2016 to December 2018 were selected including 25 cases with type Ⅲ B and 5 cases with type Ⅲ C,who were all open tibia fractures and treated with Ilizarov technique. Results All patients were followed up for 10 to 18 months with an average of 15 months. The bone defects were reconstructed, the difference between the length of the affected limb and the healthy side was less than 2 cm. The fracture was healed and the wound was closed. One case was with paralysis of common peroneal nerve and recoveried after 3 months. Twenty-two cases recovered without extra surgery, five cases restored with skin graft and three cases covered the wound by rotating skin flap. Conclusion Ilizarov technique is one of effective ways to treat Gustilo Ⅲ type B and type C of large defect combined with soft tissue defect.

OBJECTIVE: To clarify whether lycium barbarum polysaccharides (LBP) have protective effects on retina neuronal cells in diabetic rats and to identify the related mechanism involved in this process. METHODS: Eighteen SD rats were randomly divided into 3 groups ( n= 6): normal control group (NC), diabetes mellitus group (DM) and LBP-treatment group (DM+LBP). The diabetic rat model was induced by single intraperitoneal injection of streptozotocin (STZ). The rats in DM+LBP group were treated with LBP at the dose of 1 mg/kg by gavage, once a day for 12 weeks. After the treatment, the weight and blood glucose, the generation of reactive oxygen species (ROS), the surviving retinal ganglion cells (RGCs) and amacrine cells and the protein expressions of nuclear factor E2-related factor 2 (Nrf2) and the heme oxygenase-1 (HO-1) were detected. RESULTS: The successful rate of diabetic model was 100%. Compared with NC group, the rats of DM group caused weight loss, elevated blood glucose, a marked increase of ROS generation and a significant decrease in the number of RGCs and amacrine cells (P＜0.01), and these effects were diminished or abolished by LBP treatment. Meanwhile, LBP significantly increased the expressions of Nrf2 and HO-1 in the retinas of diabetic rats (P＜0.01). CONCLUSION LBP can improve retinal oxidative stress and exert beneficial neuroprotective effects in diabetic rats, and its mechanism may be associated with the activation of the Nrf2/HO-1 antioxidant pathway.
Animals ; Diabetes Mellitus, Experimental ; Drugs, Chinese Herbal ; pharmacology ; Heme Oxygenase (Decyclizing) ; drug effects ; NF-E2-Related Factor 2 ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Retina ; drug effects

To clone,express and purify the E Protein and EDⅢ of Zika virus in E.coli and prepare two kinds of polyclonal antibodies,the virus was amplified by Vero E6 cell culture.Total RNA was extracted by RT-PCR and reverse transcribed into cDNA.The prokaryotic expression vectors pET32a/E and pET28a/EDⅢ were constructed by cDNA sequence of E and EDⅢ gene.Then,recombinant plasmids were transformed into E.coli BL21 and induced by IPTG,and purified by Ni+ column affinity chromatography.BALB/C mice were immunized with purified recombinant proteins.Antiserum was collected and titer was determined by indirect ELISA.Western blot was used to detect the specificity.Results showed that the recombinant proteins were successfully expressed and purified.The titer of the polyclonal antibodies both reached 1:409 600.Western Blot analysis showed that the polyclonal antibodies could specifically recognize the recombinant proteins.Thus,the specific polyclonal antibody were successfully prepared,laying a foundation for further study on the pathogenesis,detection methods and immune strategies of Zika virus.

Objective To monitor the drug resistance of tuberculosis in Zhejiang Province and to provide scientific evidence for the control of drug resistant tuberculosis.Methods Thirty counties in Zhejiang Province were selected as sample during July 1,2013 and June 30 2014,and smear positive cases were selected to be monitored during study period. Results The rate of drug resistance was 30.88%,and the rate of multi drug resistance was 5.02%.The rate of the extensively drug -resistant tuberculosis was 0.32%.Among initial treatment cases,the rate of drug resistance was 29.22%,higher than 2008,and the rate of multi drug resistance was 3.21%.Among retreatment cases,the rate of drug resistance was 45.74%,and the rate of multi drug resistance was 21.28%.All kinds of monitored drugs were found resistance phenomenon.The drug resistant rate of SM was highest (15.28%),and aminoglycosides (2.35%)were relatively low.Conclusion The status of retreatment TB drug resistance suggested that we had reduced acquired TB drug resistance through implementation of DOTS strategy and standard short course chemotherapy treatment in Zhejiang Province. But it is still not optimistic to control TB drug resistance,and the status of initial treatment TB resistant suggested that resistant strains spread had not been effectively controlled in Zhejiang Province.So we should strengthen the early detection of drug resistant among TB patients,and to further improve the standard of conventional TB treatment.

Objective To know the application of MPB64 antigen detection of immune colloidal gold method for identification of Mycobacterium.Methods Taking the PCR amplified sequencing method as the 'gold standard',a total of 418 clinical isolated mycobacterium tuberculosis and 2 standard strains were tested by immune colloidal gold method,and was compared with the traditional method of PNB/TCH.Results Compared with sequencing method,the coincidence rate of immune colloidal gold method and PNB/TCH identification test was 95. 93%and 87. 08%respectively.The sensitivity, specificity,positive predictive value (PPV ) and negative predictive value (NPV ) of immune colloidal gold method identification were 88. 41%,99. 64%,99. 19% and 94. 58%respectively.It costs MPB64 immune colloidal gold method 15 minutes to carry out the results,less than 28 days of the traditional method,as well as 3 days of sequencing method. Conclusion Compared with PNB/TCH method,MPB64 immune antigen colloidal gold method has higher specificity and sensitivity,and could be applied in identification of Mycobacterium.