Objective To explore the effect of enriched environment on the level of NR2A and NR2B subunits of N-mehyl-D-aspartate (NMDA) receptors which belong to glutamate receptors with excitability at the 17th area of the visual cortex in amblyopia rats after the critical period,and to understand the possible mechanism of synaptic plasticity of the visual cortex in adult amblyopia rats.Methods Eighty Wistar rats were divided into normal group and experimental group by random number table.Right eyelids of all rats were sutured through the whole critical period in order to establish monocular deprivation (MD) amblyopia model.The rats in experimental group were divided into the amblyopia group,standard environment (SE) group and environmental enrichment (EE) group on P45 in random.The sutured right eyelids were opened on P46 in the SE group and EE group.All rats were sacrificed to get the 17th area of the left visual cortex on P60,P75 and P105.Three rats were used at different time points from each group.The Ⅰ-Ⅵ layers of the visual cortex area 17 were observed by using hematoxylin-eosin staining.The expression of NMDA-NR2A and NMDA-NR2B was detected by immunohistochemistry.Integrated optical density of NMDA-NR2A and NMDA-NR2B was detected by using special image analysis software (Image-Pro Plus 6.0).The use of animals complied with Regulation on the Managenment Experimental Ainimals from Shandong Eye Institute and Association for Research in Vision and Ophthalmology (ARVO).Results The positive expression of NMDA-NR2A and NMDA-NR2B were observed in the visual cortex.The positive cells were mostly round or elliptical and mainly expressed in cell membrane.The expression of NMDA-NR2A in P60,P75 and P105 from four groups had statistical differences (all at P＜0.05).There were less positive cells in amblyopia group and EE group than normal control group on P60,P75 and P105,while there were more positive cells in EE group than amblyopia group.Amblyopia can lead to reduced NMDA-NR2A expression in the visual cortex.The expression of NMDA-NR2A was stronger than that in the amblyopia group by intervention 15 days,30 days,and 60 days with the rich environments,but did not reach the normal level (all at P＜0.05).The expression of NMDA-NR2B in P60,P75 and P105 from four groups also had statistical difference (all at P＜0.05).There were more positive cells in amblyopia group than those in normal control group on P60,P75 and P105.There were more positive cells in EE group than normal control group on P60,while there were equal positive cells in EE group and normal control group on P75 and P105.Amblyopia can lead to increase NMDA-NR2B expression in the visual cortex.The expression of NMDA-NR2B was weaker than that in the amblyopia group by intervention 15 days with the rich environments,but did not reach the normal level (all at P＜ 0.05).The expression of NMDA-NR2B after intervention 30 days and 60 days reached the normal levels (all at P＞ 0.05).Conclusions The plasticity of visual cortex exists not only in the critical period but also after the critical period of visual development.EE,as a non-invasion method,can improve and recover the synaptic plasticity in visual cortex of adult rats by the expression of NMDA-NR2A and NMDA-NR2B.

Objective To introduce a new modified Bristow operation with mini-open incision and evaluate jts clinical outcomes in treatment of recurrent anteroinferior shoulder dislocation. Methods A total of 11 patients with recurrent anteroinferior shoulder dislocation were treated with modified Bristow op-eration with mini-open incision.The anterior skin incision with 3-5 mm was made to explore the coracoid process with"moving window"technique.Then.the coracoid process and its short head of biceps were os-teotornjed.transferred and fixed on the anteroinferior potion of scapular neck through the rotator cuff inter-space.All patients were followed up for an average period of 15.8 months(6-48 months)by using modified Rowe score. Results The average operation time was 45 minutes(40-65 minutes).The modified Rowe 8core ranged from 80 to 95 points.excellent in all patients, with SUCCESS rate of 100% and without any re-currence or complication. Conclusions Compared with traditional operation.the modified Bristow oper-ation has smaller incision,less trauma.shorter operation duration and better clinical results.

Objective To evaluate the clinical results of proximal humeral internal locking sys-tem(PHILOS)self-locking plates in treatment of proximal humeral fractures. Methods There were 35 patients including 19 males and 16 females(at mean age of 53.5 years,ranging from 29 to 92 years)with proximal humeral fractures treated with PHILOS plate.According to the Neer's classification sys-tem,there were two-part fractures in 19 patients,three-part fractures in 15 and four-part fractures in 1.Surgery was performed with PHILOS serf-locking plate via dehopectoral approach.All patients were fol-lowed up for mean 18.9 months(6-46 months)and evaluated by using Constant score and X-rays. Re-suits X-rays proved that all fractures got good reduction and complete healing during 8-12 weeks.The latest Constant scores was mean 89.5 points(82-94 points).There were no complications including plate loosing.humenral head necrosis or gleno-humeral ioint osteoarthritis. Conclusion PHILOS plate is a good choice for treatment of proximal humeral fractures because of its advantages including easy operation,stable fixation,good clinical results and few complications.