Effect of FK506 on expression of hepatocyte growth factor in murine spinal cord following peripheral nerve injury / 华中科技大学学报（医学）（英德文版）

This study is to investigate the effect of FK506 on expression of hepatocyte growth factor (HGF) in rats' spinal cord following peripheral nerve injury and to elucidate the mechanisms for neuroprotective property of FK506. Fifty male rats were randomly divided into normal group, injury group and treatment group. Models of peripheral nerve injury were established by bilateral transection of sciatic nerve 0.5 cm distal to piriform muscle. Then the treatment group received subcutaneous injection of FK506 (1 mg/kg) at the back of neck, while the injury group was given 0.9% saline. The L(4-6) spinal cords were harvested at various time points after the surgery. Western blotting and immunofluorescent staining were used to detect the level and position of HGF in spinal cord. Immunofluorescent staining showed that HGF-positive neurons were located in anterior horn, intermediate zone and posterior horn of gray matter in normal spinal cord. Western blotting revealed that there was no significant difference in the expressions of HGF between the injury group and the normal group, while the expression of HGF was significantly higher in the treatment group than in the injury group 7 and 14 days after surgery. It is suggested that peripheral nerve injury does not result in up-regulation of the expression of HGF in spinal cord, while FK506 may induce high expression of endogenous HGF after injury thereby protecting neurons and promoting axonal outgrowth.

Differentiation of mesenchymal stem cells into nucleus pulposus cells in vitro / 华中科技大学学报（医学）（英德文版）

To find a new source of seed cells for constructing tissue-engineered intervertebral disc, nucleus pulposus (NP) cells and mesenchymal stem cells (MSCs) were isolated from New Zealand white rabbits. The nucleus pulposus cells population was fluorescence-laelled and co-cultured with MSCs with or without direct contact. Morphological changes were observed every 12 h. Semi-quantitative reverse transcriptase-polymerase chain reaction was performed to assess the expression levels of Sox-9, aggreacan and type II collagen every 24 h after the co-culture. MSCs treated with direct contact rounded up and presented a ring-like appearance. The expression of marker genes was significantly increased when cells were co-cultured with direct contact for 24 h. No significant change was found after coculture without direct contact. Co-culture of NP cells and MSCs with direct contact is a reliable method for generating large amount of NP cells used for cell-based tissue engineering therapy.

Effect of tacrolimus on expression of hepatocyte growth factor in rat spinal cord following peripheral nerve injury / 中国矫形外科杂志

[Objective]To explore the effect of tacrolimus on expression of hepatocyte growth factor(HGF)in rat spinal cord following peripheral nerve injury.[Method]Fifty male rats were randomly divided into normal group,injury group and treatment group.Models of peripheral nerve injury were established by transection of bilateral sciatic nerve at 0.5 cm distal to piriform muscle.Then treatment group received subcutaneous injection of tacrolimus(1 mg/kg)at the back of the neck,while injury group received 0.9 % saline.The L4~6 spinal cords were harvested at various time points after surgery.Western blotting and immunofluorescence staining were used to detect the level and position of HGF in the spinal cord.[Result]HGF-positive neurons were located in anterior horn,intermediate zone and posterior horn of gray matter in normal spinal cord.There was no significant difference in the expressions of HGF between injury group and normal group,while the expression of HGF was significantly higher in treatment group than that in injury group at 7 and 14 days after surgery.[Conclusion]Peripheral nerve injury does not up-regulate the expression of HGF in spinal cord,while tacrolimus can induce high expression of endogenous HGF after injury to protect neurons and promote axonal outgrowth.

Long term effects of end-to-end suture on repairing acute closed Achilles tendon ruptures / 解放军医学杂志

Objective To retrospectively evaluate the clinical effects of end-to-end suture in repairing acute closed Achilles tendon ruptures.Methods Twenty-eight consecutive patients(20 males and 8 females,aged from 19 to 48 years with a mean of 36.5) with acute closed Achilles tendon rupture admitted from Nov.2000 to Jun.2006 were involved in present study.All patients were produced to have complete Achilles tendon rupture by MRI,and they received surgical procedure within 4 days after injury.An incision of 1cm long was made medial to the tendon,sparing the lesser saphenous vein and sural nerve.The tendon stumps were minimally debrided and end-to-end sutured using the Kessler or Bunnell techniques.The patients were followed-up for 12 to 36 months(mean 20 months),the therapeutic effects were evaluated by Arner-Lindholm scoring system,and postoperative complications were documented during the follow-up period.Results Of the 28 patients,19 got excellent therapeutic effect and 9 got good as evaluated by Arner-Lindholm scoring system,the satisfactory rate was 100%.All the patients regained normal gait,and rehabilitative training was initiated 3 months after operation.The postoperative complications included superficial wound infection in one case and skin edge necrosis in one case,resulting in a 7.1% incidence of complication.No peripheral nerve injury or Achilles tendon re-rupture occurred during the follow-up period.Conclusions An excellent therapeutic effect and minimal postoperative complication may be expected with end-to-end suture for repairing acute closed Achilles tendon rupture.