Objective:To observe the effects of double-stranded small interfering RNA (siRNA) of the silent mating-type infor-mation regulation 2 homolog 1 (SIRT1) on the cell proliferation, cell cycle progression, and expression levels of the cell cycle negative regulators. These regulators include P21, P27, and phosphorylated retinoblastoma (PRb) proteins present in prostate cancer PC3 cells. This work further aims to explore the possible underlying mechanism for such effects. Methods:PC3 cells were cultured in vitro and then randomly divided into the mock group, scramble siRNA transfected group, and SIRT1 siRNA-transfected group. SIRT1 siRNA ef-ficiency was examined through reverse transcription polymerase chain reaction and Western blot analysis. The inhibitory rate of PC3 cell growth was determined through a methyl thiazolyl tetrazolium assay, and the cell cycle was investigated with the use of flow cytom-etry. The P21 and P27 protein expression levels and PRb status were determined by Western blot assay. Results:Compared with those of the mock and scramble siRNA groups, the expression levels of SIRT1 mRNA and protein significantly decreased in SIRT1 siR-NA-transfected cells. In addition, the inhibitory rate of PC3 cell growth was markedly increased, and the cell cycle of the PC3 cells was arrested at the G1 stage. The expression levels of negative cell cycle regulators, including P21 and P27 protein levels increased, whereas Rb protein phosphorylation was inhibited in SIRT1 siRNA-transfected PC3 cells. Conclusion: SIRT1 RNA interference inhibits PC3 cell growth and arrests cell cycle progression through the upregulation of the P21 and P27 proteins and the inhibition of Rb protein phosphorylation.

Objective To investigate a new method for reconstruction of posterior cruciate ligament(PCL)using hamstrings tendons knot and bone lock-bolt under arthroscopy.Methods Ten cases of PCL lesion were treated arthroscopically. Hamstrings were harvested with a stripper following standard procedure. The hamstring tendons tied a knot at the inter-media part of the tendons and insert a bone lock-bolt on the knot. The tunnel of femur and tibia were prepared. Tunnel diameter of the tibia and the infra 1/3 of femur was 5-7mm and the superior 2/3 of the femur side was 11-12mm,Pulling in the tendon from the lateral side of femur tunnel to the tibia.A hole of 4 5mm was drilled 1cm distal of tibia tunnel exit. Create a bone bridge using curved clamps,passing a tendon under the bone bridge and tying the tendon over the bone bridge in extension.Results All the patients were follow-up.Function and stability of knee during walking and activities improved apparently. All patients were evaluated with the knee functional scales.Patients were clinically rated as excellent in 6,good in 3,and fair in 1. There were no poor results.Conclusion The result of using semitendinosus and gracilis tendons tied a knot and implant a bone lock-bolt to reconstruct PCL is satisfactory. The advantages of the technique included well biological match, exemption from costly materials, promotion of healing of tendons and bone tunnel, decrease in medical cost.

Objective To study the effect of arthroscopic plasty of discoid meniscus with local anaesthesia and radiofrequency. Methods From Aug. 2000 to Aug.2002, arthroscopic plasty of discoid lateral meniscus with local anaesthesia and radiofrequency was performed on twenty-six joints in twenty-three patients including 12 male and 11 female, their average age was 25 years(13～14 yrs). The procedure of discoid meniscus reshaping in 23 cases was to produce the similar appearance to the normal lateral meniscus. Unstable leaf of the horizontally torn meniscus was removed, while the stable one was preserved. In 6 cases,the tear of edge rim was not only reshaped but also insider-out sutured. Results 21 cases were followed-up for average 11 months (from 5 months to 2 5 years).There was no pain snap and lock, the joint function is normal in 21 cases and 23 knees. Based on Ikeuch knee functional scales,16 cases were rated as excellent, 3 good and 2 fair. Conclusion Arthroscopic radiofrequency meniscus plasty is of importance in avoiding total meniscectomy. The procedures were safety and less traumatic.

Objective To study the effects of isotonic and resistance exercises on renal hormones in plasma. Methods Eight healthy men were instructed to performed isotonic and resistance exercises, respectively, with the same target heart rate and the same exercise duration, in which both exercises-induced changes of plasma renin activity (PRA), aldosterone (ALDO) and antidiuretic hormone (ADH) were observed. Results Plasma levels of PRA, ALDO and ADH increased significantly after both isotonic exercise and resistance exercises. Plasma levels of ADH and PRA were higher after resistance exercise than those after isotonic exercise. Conclusion The increases of PRA, ALDO and ADH in plasma caused by exercise might be an adaptive response to maintain balances of water and electrolyte in the status of physical stresses. The tendency of increase of ADH and PRA after resistance exercise suggested that the exercise intensity rather than type of exercise correlated with on the changes of renal hormones.

We investigated whether platelet-activating factor (PAF) mediates endotoxin-induced changes of lipoperoxidation, lysosomal enzyme release and increased extravascular lung water content in dogs using a specific PAF receptor antagonist, SRI 63-441. Endotoxin infusion caused an increase in serum malonyldialdehyde (MDA) from baseline (100%) to 130.04?14.00% and 169.16?32.49% and ?-glucuronidase (?-g) activity to 191.05?86.71% and 242.54?49.09% at 3 and 6h, respectively. The bronchoalveolar lavage fluid (BALF) ?-g activity, lung MDA and extravascular lung water also significantly increased (P

The effects of hydrogen peroxide (H2O2) on endothelial-polymorphonuclear cells (EC-PMN) adhesion and their mechanisms wsre studied in cultured bovine pulmonary artery endothelial monolayers in vitro. H2O2 at various concentrations (10-1, 10-2, 10-3mol/L respectively) stimulated EC dependent PMN adhesion, of which l02mol/L H2O2 was the most potent one, increasing adhesion to 2.3 times that of the control. Pretreatment of PMNs with SRI 63-441, a platelet-activating factor (PAF) receptor antagonist, had no effect on H2O2 induced EC-PMN adhesion. Pretreatment of ECs with SRI 63-441 before H2O2 exposure significantly decreased PMN adherence to ECs. Pretreatment of ECs with phospholipase A2 inhibitor p-bromophenacyl-bromide or cahnodulin antagonist chlorpromazine and aildum ion chelate EGTA obviously decreased H2O2 induced increment of EC-PMN adhesion. These results suggest that H2O2 may activate ECs, causing the inflow of extracellular calcium or the release of calcium from intracellular deposits. Increased intracellular Ca2+ may bind with calmodulin to activate phospholipase A2 thus initiating PAF synthesis and promoting EC-PMN adhesion.

The effect of the selective debridement with the aid of the arthroscope performed under local anesthesia for osfeoarthritis of 296 knees in 260 patients was studied. The pathological changes of osteoarthritis under the arthroscopy include hyperplasia of synovial membrane, degeneration of cartilage or exposure of subchondral bone on the stress areas of the femur condyles and patella , wear and tear of meniscus, formation of osteophyte and loose body. The debridement included the removal of the loose body, hyperplasia of synovial membrane, degenerated cartilage, and the torn meniscus. Many factors,including age of the patients, selection of the indication, stress of the knee joint, and the degeneration of cartilage,may influence the curative effect. After selecfive debridement and lavage for osteoarthritis of the knee joint, the majority of patients were released from pain, with restoration of function and range of motion, and the development of pathological process was retarded. Good and excellent results constitute 74.7% of the patients.

Bi-polar,bi-pedicled separation delayed flaps were designed on the backs of New Zealand rabbits with the application of a medical silicon membrane as the separation material. Values of glucose and lactic acid, PtcO 2 were measured separately at proximal,middle and distal areas of the flaps after the distal pedice was cut at 0,1,4,7,14,21 days,respectively, after the formation of flaps. After flap delaying,PtcO 2 in separated flap was always lower than that of the mormal control,accompanied with glucose decrease and lactic acid increase, although there were significant differences in different areas of the flap. The survived area of the flap increased after 7 days. Furthermore,all the length of the flap survived after 21 days,although the level of glucose in the flap was still lower and lactic acid was still higher.The results suggested that by separation and delaying the flap may adapt gradually to hypoxia via lowered metabolism.For flap survival,the threshold value of glucose in flap is 0 01mmol/L , lactic acid is 0 47mmol/L,and PtcO 2 is 3mmHg .

Relation between change of capillary pressure, survival length in bi pedicled separation delay flap was observed. Bi polar, bi pedicled separation delay flaps were designed on the backs of New Zealand rabbits. Medical silicon membrane was used as separative material. Values of capillary pressure were measured at proximal, middle and distal points. Survival length increased with delayed time, capillary pressure at middle was lower in the bi pedicled separation delay flap. It is concluded that capillary pressure is increased greatly by separation delay, and there is a linear relation between capillary pressure and survival length of flaps.

To evaluate the curative effect and value of arthroscopic surgery in the treatment of elbow diseases. Eighteen patients with elbow diseases (osteoarthritis, rheumatoid arthritis and articular adhesion) were treated with arthroscopic surgery from May 1999 to January 2003. The modified HSS elbow rating scale was used as the criteria of the efficacy. All patients were followed up for 3 to 34 months (an average of 13 months). Among eighteen patients, eleven showed excellent results, six good, one poor, and the satisfactory rate was 94.4%. It is concluded that arthroscopic surgery for elbow ailments is a safe and reliable method with the advantages of less trauma and earlier recovery. Injury to vessels and nerves may be avoided with the use of local anesthesia.