SIRT1 Inhibits High Shear Stress-Induced Apoptosis in Rat Cortical Neurons.

INTRODUCTION: Sirtuin1 (SIRT1), one of NAD+-dependent protein deacetylases, is proved to be neuroprotective in aging diseases, but its effect on neuronal apoptosis has not been clarified. To investigate the role of SIRT1 in inhibiting neuronal apoptosis, SIRT1 was interfered or overexpressed in cortical neurons. METHODS: We exerted overloading laminar shear stress with 10 dyn/cm2 for 4, 8, and 12 h on neurons to cause cortical neuronal apoptosis, and the apoptosis percentage was tested by TUNEL assay. The adenovirus plasmids containing SIRT1 RNA interference or SIRT1 wild type gene were transfected into neurons before shear stress loading. SIRT1 mRNA and protein level were tested by Real-time PCR, immunofluorescence and western blots assay. RESULTS: SIRT1 was primarily expressed in nucleus of cortical neurons, and its mRNA level was significantly increased after 4 h stimulation. SIRT1 RNAi cortical neurons had higher TUNEL positive cells, while SIRT1 overexpression significantly decreased the percentage of died cells induced by shear stress compared to control group. CONCLUSIONS: SIRT1 plays a neuroprotective role in shear stress induced apoptosis and could be as potential pharmacological targets against neuronal degeneration in future.

[The therapeutic effect analysis of three kinds of methods for the management of post traumatic knee stiffness].

OBJECTIVES: To investigate the therapeutic effect of rehabilitation, arthroscopy and "hybrid technique" for posttraumatic knee stiffness (PTKS), and to make the best choice for the treatment. METHODS: From February 2004 to November 2009, 66 patients suffered from PTKS were treated, and the clinical data were studied retrospectively, 36 male and 30 female patients with an average age of 41 years were analyzed, knee stiffness time averaged 15 months (0.5 - 108.0 months), 21 cases of patients were treated with rehabilitation (rehabilitation group), 22 cases of patients with arthroscopy + rehabilitation (arthroscopy group) and 23 cases of patients with mini-invasive "hybrid technique" + rehabilitation (hybrid technique group). For each case, the difference of range of motion (ROM) and hospital for special surgery (HSS) score of the knee before and after the treatment were analyzed statistically. The characters of PTKS including the course of the disease, the degree of extensor mechanism involving, physical examination and other ancillary data were also analyzed. The management methods for PTKS were summarized. RESULTS: Total 66 cases were followed up ranging from 24.0-72.5 months and the mean time was 34.2 months. The average ROM was improved obviously: rehabilitation group increased from 45° ± 22° to 95° ± 24° (t = -11.2, P < 0.05), arthroscopy group from 47° ± 26° to 118° ± 11° (t = -11.0, P < 0.05) and hybrid technique group from 36° ± 22° to 110° ± 14° (t = -13.4, P < 0.05). Both ROM and HSS score of the knee before and after the treatment for each group showed significant difference statistically (t = -9.1, -6.0, -5.2, P < 0.05). Wound necrosis, tearing, re-fracture and extension lag were not found. According to Judet standard at final follow-up, 15 cases were excellent, 3 cases good and 3 cases normal in rehabilitation group; 15 cases were excellent, 5 cases good and 2 cases normal in arthroscopy group; 14 cases were excellent, 8 cases good and 1 case bad. CONCLUSIONS: Pathology of PTKS is complex, satisfactory result could be obtained through individualized treatment program, which were established depend on the course of the disease, the degree of extensor mechanism involving, physical examination and ancillary data. The timely and effective surgical interference followed by a comprehensive rehabilitation program is the key point for satisfied outcome.

[The treatment of dorsally displaced intra-articular fractures of the distal radius via palmar approach].

OBJECTIVE: To treat dorsally displaced intra-articular fractures of the distal radius, and to assess the integrity of radiocarpal joint and the reliability of stable fixation fracture. METHODS: Sixty-three cases (65 sides) patients with dorsally displaced intra-articular fractures of the distal radius were performed operatively with the open reduction and internal fixation via palmar approach between August 2003 and May 2008. The series included 20 males (21 sides) and 43 females (44 sides). The mean age of patients was 52.4 years ranging from 18 to 82 years. According to the Frykman classification, 6 sides were of type III, 8 of type IV, 5 of type V, 4 of type VI, 13 of type VII and 29 of type VIII. With the exception of the radiocarpal arthrography and the standard antero-posterior and lateral views of the wrist joint, two new tangential antero-posterior and lateral views of the wrist joint were intraoperatively described so as to observe the relation of the distal screws with the articular surface. RESULTS: The 53 cases (54 sides) of the 63 cases (65 sides) were followed up, and the follow-up time was averagely 16.4 months ranging from 4 to 47 months. According to Gartland and Werley criteria, 32 sides were rated as excellent (59.3%), 14 sides as good (25.9%), 7 fair (13.0%) and 1 poor (1.8%), and the excellent-good rate was 85.2%. Observing the new tangential antero-posterior and lateral views of the wrist joint, it showed that screws appeared penetrating into the radiocarpal joint in 26 of the 42 sides by standard antero-posterior view and in 31 of the 42 sides by standard lateral view. CONCLUSION: This palmar approach represents a simple and valuable treatment methodology for the most frequent types of unstable fractures of the distal radius in young and elderly patients.