BACKGROUND:The clinical study on the mechanical properties of biomaterials for cruciate ligament reconstruction is of great importance, which can provide a theoretical basis for the clinical development of materials with good structure, biomechanics and compatibility. OBJECTIVE:To analyze the mechanical properties of vascularized patelar tendon graft. METHODS:The anterior cruciate ligaments of the left foreleg from 42 New Zealand white rabbits were cut off. Then, these rabbits were randomly and evenly divided into two groups: experimental group and control group. Rabbits in the experimental group were implanted vascularized patelar tendon graft for anterior cruciate ligament repair. Rabbits in the control group were implanted with autologous non-vascularized patelar tendon graft for anterior cruciate ligament repair. At the 8th, 12th and 16th weeks after implantation, biomechanical properties of specimens from these two groups were detected. RESULTS AND CONCLUSION: There was no significant difference on the fracture location at different time points between these two groups; at the 12th and 16th weeks after transplantation, the knee laxity in the experimental group was higher than that in the control group (P < 0.05). At the 8th week after transplantation, there was no significant difference in the knee laxity between these two groups. At the 8th, 12thand 16th weeks after transplantation, the maximum load in the experimental group was higher than that in the control group (P < 0.05). At the 8th, 12th and 16th weeks after transplantation, the stiffness in the experimental group was higher than that in the control group (P < 0.05). There was no significant difference in the maximum tensile elongation between these two groups at different time points after transplantation. These results demonstrate that vascularized patelar tendon graft has good mechanical properties.

Objective To construct recobinant pmRNA IRES-hKDR and lay a primary foundation for further study of gene therapy for tumors.Methods pmRNA IRES-hKDR was obtained from pDC520 hkDR and pmRNA IRES-Luc which was reserved by our laboratory through molecular biology technology and was transfected into Hepall-6 via lipsome after identification of PCR,restriction enzyme digesting and DNA ELISA and Western blot.Results The recombiant plasmid had pmRNA IRES-hKD gene which was expressed in Hepall-6//G418 in vitro and the expressed protein was secreted out of the cells could response with specific hKDR antibody,which was identified by Western blot.Conclusion An eukaryotic expression recombiant plasmid pmRNA IRES-hKDR can be constructed successfully which provides the possibility of further researches on its anti-tumor effect.

Objective To investigate the immune protection of dendritic cells(DCs) harboring kinase domain-containing receptor(KDR) fusion gene on mice carrying B16 melanoma.Methods The bone marrow precursor-derived dendritic cells(BMDCs) were induced from bone marrow progenitors of mice by GM-CSF.The KDR fusion gene mRNA was transfected into DCs in vitro.Mice were immunized with the same amount of DCs at 7-day interval and then each mouse was injected with 5?10~5 B16 cells.The mice without tumors were injected with B16 cells again 20 days later.Mice were randomly divided into 4 groups: group A(n=7),group B(n=8),group C(n=8) and group D(n=7).The mice were immunized with DCs one time in group A,2 times in group B,3 times in group C and as controls in group D.Results After one week,all mice in group D had tumors with average survival 15 days.All mice in group A,B and C had no tumors after 20 days later.After the second injection of B16 cells,2 mice in group A and 2 mice in group B had tumors.The mice in group C had no tumor.The average survival periods were calculated from first injection of B16 cells to the study end.The average survival period of group A was 50 days and that of group B was 72 days.Conclusions The dendritic cells vaccine harboring KDR fusion gene has immune protection against melanoma in mice.

Objective To evaluate the relationship between endogenous protective mechanism of intestinal barrier injury induced by cardiopulmonary bypass ( CPB) and enteric glia cells in rats. Methods Forty-eight clean-grade adult male Sprague-Dawley rats, weighing 400-500 g, were divided into 2 groups (n=24 each) using a random number table method: sham operation group (group S) and CPB group. Rats were sacrificed at the beginning of CPB, 60 min of CPB, and 2 and 6 h after CPB, and the intestinal tissues were removed for examination of pathological changes ( by HE staining) and for determina-tion of the expression of ZO-1, occludin, glial fibrillary acidic protein ( GFAP ) and calcium-binding pro-tein ( S-100) and the positive expression of GFAP ( by immunohistochemical method) . Results Compared with group S, the expression of GFAP and S-100 was significantly up-regulated at 60 min of CPB and 2 and 6 h after CPB, the expression of ZO-1 and occludin was down-regulated (P<0. 05), the positive expres-sion of GFAP was enhanced, and the intestinal mucosal injury was marked in group CPB. Conclusion The enhanced activation of enteric glia cells may be involved in the endogenous protective mechanism of in-testinal barrier injury induced by CPB in rats.

Objective To examine the impact of loneliness on cognitive impairment among community-dwelling elderly people.Methods A cross-sectional survey was conducted between July and August 2015 with 895 community-dwelling elderly participants in four residential areas of Wuchang District,Wuhan.The Montreal Cognitive Assessment (MoCA) was used to measure cognitive function.Chi square test,t-test,and multivariate linear regression were used to analyze the data.Results Multivariate linear analysis showed that loneliness was independently and negatively associated with cognitive function among the participants (β=-1.2828,95％ CI:-2.27--0.30).Participants who felt loneliness recorded lower scores on visuospatial executive,attention,and language ability than those who did not (P＜0.05).Multivariate logistic analysis demonstrated that loneliness was also associated with cognitive function after adjustment for age and gender,with OR (95 ％CI) at 1.74(1.05 2.91) / 1.78 (1.07 2.94).Loneliness remained an independent risk factor for cognitive dysfunction after adjustment for age,gender,education level,monthly income,living arrangement,physical activity,mental activity,hypertension,diabetes,frequency of social interaction,and type of social interaction,with OR (95％CI) at 1.69(1.002.87) / 1.72(1.022.90).Conclusions Loneliness is a significant and independent impact factor for cognitive dysfunction among community dwelling elders.

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Objective:To evaluate the mechanism of α7 nicotinic acetylcholine receptor (α7nAChR) agonist-induced protection of the intestine in rats undergoing cardiopulmonary bypass (CPB) and the relationship with the activity of enteric glial cells (EGCs).Methods:Seventy-two clean-grade adult male Sprague-Dawley rats, aged 400-500 g, were divided into 3 groups ( n=24 each) using a random number table method: sham operation group (group S), CPB group (group C) and α7nAChR agonist PHA568487 plus CPB group (group P). In group P, PHA568487 0.8 mg/kg was intraperitoneally injected, and 30 min later CPB model was established.At the beginning of CPB (T 0), at 1 h of CPB (T 1), and at 2 and 6 h after termination of CPB (T 2, 3), the rats were sacrificed, and intestinal tissues were obtained for examination of the pathological changes and for determination of the expression of ZO-1, occludin, glial fibrillary acidic protein (GFAP), and calcium-binding protein (S-100β protein) by Western blot.The immunohistochemical method was used to observe the positive expression of GFAP at T 2. Results:Compared with group S, the expression of GFAP and S-100β protein was significantly up-regulated, and the expression of ZO-1 and occludin was down-regulated at T 1-3( P<0.05), the positive expression of GFAP was increased, and the intestinal tissue injury was accentuated in C and P groups.Compared with group C, the expression of GFAP, ZO-1 and occludin was significantly up-regulated, and the expression of S-100β protein was down-regulated at T 1-3( P<0.05), the positive expression of GFAP was increased, and the intestinal tissue injury was reduced in group P. Conclusion:The mechanism by which α7nAChR agonist attenuates intestinal injury may be related to activating EGCs and improving intestinal barrier function in rats undergoing CPB.

Objective To assess the effect of ultrasonic thyroid artificial intelligence(AI)-assisted diagnostic system(AI-assisted diagnostic system)for diagnosing medullary thyroid carcinoma(MTC)compared with different physicians and taken papillary thyroid carcinoma(PTC)as the controls.Methods Totally 63 MTC,70 PTC and 62 benign thyroid nodules confirmed by pathology were enrolled.AI-assisted diagnostic system was utilized to analyze thyroid nodules and identify the likelihood of malignancy,and the probability value threshold was set at ≥0.40.All thyroid nodules were retrospectively reviewed and categorized by 3 physicians(1 senior physician,1 attending physician and 1 junior physician)according to Chinese thyroid imaging reporting and data system(C-TIRADS).The efficacy of AI-assisted diagnostic system and physicians for diagnosing MTC and PTC were evaluated.Results AI-assisted diagnostic system showed lower sensitivity,specificity,positive predictive value,negative predictive value,accuracy,and area under the curve(AUC)for diagnosing MTC and PTC compared with physicians.Significant differences of AUC were found between senior physician and AI-assisted diagnostic system,as well as between attending physician and AI-assisted diagnostic system for diagnosing MTC and PTC(all P＜0.01),while no significant difference of AUC was between junior physicians and AI-assisted diagnostic system(both P＞0.05).The sensitivity,specificity,positive predictive value,negative predictive value,accuracy and AUC for AI-assisted diagnostic system for diagnosing MTC were all lower than those for diagnosing PTC,but the AUC was not significantly different(P＞0.05).Conclusion Ultrasonic thyroid AI-assisted diagnostic system had relatively high value for diagnosing MTC.