Objective To investigate the difficulties in posterior approach lumbar microendoscopic discectomy (MED). Methods We retrospectively analyzed records of 42 cases of lumbar disc protrusion (totally 45 interspaces) treated by MED from February 2002 to October 2003. Results Conversion to open surgery was required in 3 cases.No intra- or post- operative complications were seen.Follow-up survey for 2 ～ 22 months (mean,8 months) found the "good" or "excellent" results in 95 2% of the patients (40/42).Surgical difficulties were mainly classified into two aspects: technical and etiological,including 8 cases of failure of collimation between the passage and the interspace,5 cases of excessive bleeding disturbing the operation,3 cases of incomplete surgical apparatus,2 cases of incorrect passage localization,2 cases of hyperplasia in tiny joints,1 case of ossification of the posterior longitudinal ligament,1 case of nerve root edema,1 case of accretion,and 1 case of laceration,respectively. Conclusions Treatment of lumbar disc protrusion with MED gives satisfactory efficacy.Proper selection of patients and careful performance during surgery are essential to a successful procedure.

Description of the practice, significance and principles of networking operation for primary medical institutions in Shenzhen, and an introduction to the strategy and implementation assurance. The paper covered the following features of such operation: establishment and upgrading of the primary patients movement system; establishment of the tiered health service system; establishment of the consultation and referral system based on networking operation; establishment of multi-institution practice system for physicians within the network; establishment of medical resources sharing system within the network; support for joint research programs; experiment in effective medical insurance payment and health service price support system; diversity and loose structure of institutions within the network

Objective In order to understand the chondrogenesis differentiation of mesenchymal stem cells in either hydrogel or pellet culture,we applied the two methods and reveal the possible mechanism and for further investigation.Methods In C3H10T1/2 chondrogenic differentiation,we apply extracellular matrix hydrogel mixed the cell suspensions of freshly prepared (including scaling chondroitin sulfate,sodium hyaluronate synthesis and cross-linking agent) co-culture system and high cell density pellet formed by centrifugation.Chondrogenic differentiation of C3H10T1/2 was induced by treatment with TGF-β3 (10 ng/ml),dexamethasone (100 nmol/L),ascorbic acid (50 ug/ml),1 ∶ 100 dilution ITS+Premix and high glucose-DMEM medium with 0.2 volume fraction fetal bovine serum.And high glucose-DMEM medium with 0.2 volume fraction fetal bovine serum is for control group.Histochemistry staining was utilized to identify extracellular proteoglycan and real-time PCR was performed to assess gene expression of SOX9,collagen Ⅱa1/Ⅹa1 and aggrecan for the 1st,2nd and 3rd week respectively.Results In the hydrogel model for 3 weeks chondrogenic differentiation,the expression of master transcription factor SOX9 was upregulated in both culture models.While the marker genes of collagen Ⅱa1 and collagen Ⅹa1 were all promoted in hydrogel culture,the aggrecan gene expression was peaked in pellet culture.In addition,immunocytochemistry analysis of the hydrogel and pellet for 3 week illustrated the expression of extracellular matrix and more obviously in the hydrogel model.Conclusion In compared with pellet culture,the MSCs in the hydrogel were more likely promoted chondrogenesis leading to the eventual expression of marker genes.And the hydrogel would be applied in regeneration of cartilage injury.