BACKGROUND:Vascular endothelial growth factors (VEGF) can promote the division of endothelial cells and accelerate the growth of newborn vessels, whereas the expression and distribution of VEGF receptors (VEGFR) in spinal cord should be observed.OBJECTIVE: To observe the expression and distribution of VEGFR-1 and VEGFR-2 in rat spinal cord.DESIGN: A randomized controlled observation.SETTING: Department of Orthopaedic Surgery, the First Affiliated Hospital of Dalian Medical University; Department of Hand Surgery, Union Hospital affiliated to Tongji Medical College, Huazhong University of Science and Technology.MATERIALS: Ten adult male Wistar rats of clean degree, weighing 180-200 g, were provided by the animal experimental center of Tongji Medical College, Huazhong University of Science and Technology. Immunohistochemical primary antibody was purchased from Santa Cruz Company; the second and third antibodies from Beijing Zhongshan Biotechnology Co., Ltd. Reverse transcription-polymerase chain reaction (RT-PCR) kit was the product of Promega,Trizol reagents were purchased from Invitrogen Company, and the VEGFR-1 and VEGFR-2 primers were designed by Beijing Aoke Company.METHODS: The experiment was carried out in the laboratory of Department of Hand Surgery of Wuhan Union Hospital from March to June in 2004. ① Detection of VEGFR expression in spinal cord anterior horn: The rats were anesthetized by 100 g/L chloral hydrate, spinal cord of lumbar 4-6 (L4-6) was fixed in fixation solution at 4 ℃ for overnight, then routine dehydration, hyalinization and paraffin embedding were performed, and serial sections of about 5 μm were prepared for observing the VEGFR expressions using immuniohistochemical staining. ② Detection of VEGFR mRNA expression in spinal cord: Five rats were selected, L4-6 spinal cord (50 mg) was removed and centrifugated, then the content of total RNA was determined with ultraviolet spectrophotometer. The synthetized cDNA was amplified with PCR, and the PCR products (10 μL) were treated with 20 g/L agarose gel electrophoresis, and stained with 0.1 mg/L ethidium bromide, the results were observed and recorded under ultraviolet lamp and photographed. The products were scanned and quantified with gel imaging analytical system to record the gray value of each band, the gray value of β-actin band was taken as 1,and those of the other objective fragments were compared with it to record the gray value ratio and analyze the expressions of the objective fragments.MAIN OUTCOMEMEASURES: ① Expression and distribution of VEGFR-1 and VEGFR-2 in rat spinal cord anterior horn;② Results of VEGFR mRNA expression in spinal cord.RESULTS: ① Both VEGFR-1 and VEGFR-2 were expressed in the microvessels of normal rat spinal cord tissue.Besides, VEGFR-2 mainly expressed in motor neurons, glial cells and the nerve fibers in surrounding white matter. ②The results of gel imaging analytical system showed that the VEGFR-2 content in normal spinal cord was obviously higher than VEGFR-1 (0.874±0.222, 0.486±0.181, P ＜ 0.05).CONCLUSION: VEGF promote the formation of microvessels through the combined effects of VEGFR-1 and VEGFR-2,and it plays the neurotrophic and neuroprotective role through VEGFR-2.

[Objective]To study the effect of End-to-side neurorrhaphy for protection target muscle.[Method]Twenty-six wistar rats were divided into two groups,with 13 in each group,peroneal nerve was transacted on the right side of all the animals,in one group,the proximal end of peroneal nerve was turned back and ligated,the distal end was sutured to the side of tibial nerve with perineurial window,in another group,both ends of the transacted peroneal nerve were turned back and ligated as contrast,no operation was done on the left side.Three months after operation,the peroneal nerve and the tibial muscle were taken for histologic exmination,and the muscle's wet weight was examed.[Result]Significant difference was seen between the two groups in the muscle wet weight,the muscle fiber cross sectional area,the moter endplate area and color(P

Objective To demonstrate the presentation of the extracellula ATP receptors in peripheral nerve in rats Methods Reverse transcriptase polymerase chain reaction was performed in sciatic nerve of rat Results There were three P2y receptor mRNA expressions in the in the sciatic nerve of the rat,they were P2y2 and P2y4 as well as P2y6 Conclusions Extracellular ATP,as a neurotransmitter,activates the P2y purinoceptors located on the axon regeneration after peripheral nerve injury and decided the direction of the regeneration axon The P2y receptors are related to the regeneration of the peripheral nerve

This study is to investigate the effect of local phVEGF(165) injection on sciatic nerve regeneration in the rats and to search for a new way in the further treatment of peripheral nerve injuries. Forty-five adult male Wistar rats received a neurotomy to bilateral sciatic nerves, which were subsequently reconnected with 10/0 epineurial nylon sutures. The injured segments was locally injected with normal saline (group A), or 25 microg of phVEGF(165) (group B) or 50 microg phVEGF(165) (group C). Nerve conduction and regeneration were evaluated in terms of the histological changes, weight of gastrocnemius muscles, electrophysiology and morphometric results. Our study demonstrated that rats of group C showed the best results in terms of nerve regeneration, followed by group B and group A. Our findings suggested that local injection of phVEGF165 can facilitate nerve regeneration and promote functional recovery in a dose-dependent manner.

To identify the best suture techniques for the tendon repair, the biomechanical properties of tendons sutured by different methods were dynamically examined. 140 chickens were divided into 2 groups equally: group A and group B. The tendon of the right side was subjected to injury-repair process, and the tendons of the left sides served as controls in both groups. In group A, "figure-of-8" suture, modified Kessler suture and Bunnell suture were used for the 2nd to 4th paws respectively, while in group B, Kleinert suture, Tsuge suture and Ikuta suture were used. On the day 0, 3, 7, 14, 21, 28, 42 after operation, 10 animals were sacrificed and the flexor tendons of both sides were harvested for strength test. The results showed that the initial strength of the repaired tendons and the strength after 6 weeks following tendon cut were far below those of intact tendons, irrespective of suture techniques used. With the 6 techniques, the P(max) of tendons repaired by Tsuge suture was increased continually, reaching the highest value on the 42nd day. The P(max) of tendons sutured by the modified Kessler suture was slightly lower than that by Tsuge suture, but it was increased steadily in healing. The tendons repaired by figure-of-8 suture yielded the lowest P(max). It was concluded that Tsuge suture and modified Kessler suture were the best techniques for tendon repair.
Biomechanics ; Chickens ; Suture Techniques ; Tendon Injuries/*surgery ; Tendons/*surgery ; Tensile Strength ; Wound Healing

Objective To evaluate results of reconstructing thumb opposing function by transfering the extensor carpi ulnaris and the extensor pollicis longus muscle tendons. Methods Forty-nine patients with dysfunction of thumb opposing were admitted to this study. Twenty-nine had median nerve injury in the wrist, twenty complicated ulnar nerve injury at the same time. Thumb opposing function of all patients was reconstructed by transfering the extensor carpi ulnaris and the extensor pollicis longus muscle tendons. Results All patients with median nerve injury got satisfactory results. 80% of patients complicated ulnar nerve injury got fine therapeutic effect. Conclusion It is a convenient and efficient procedure that reconstructing thumb opposition function by transfering the extensor carpi ulnaris and the extensor pollicis longus muscle tendons.

Objective To prove the extracellular ATP attracts the axonal regeneration after peripheral nerve injury via the ATP receptor Methods The sciatic nerve defects had been made in 10 female Sprague Danley rats and repaired by"Y" form silicon tube The single arm of the"Y" form tube were sutured with the proxma the sciatic nerve and the other two end of silicon tube sutured by paralled or cross method so as to differentiate the experimental side and control side, 1mmol/L 10 ?l ATP and 1mmol/L 10 ?m ATP+ 0 2mg/ml Suramin were injected differently into two arms of left side and 10 ?l physiological saling and 10 ?l 0 2mg/ml Suramin injected differently into two arms of right dide The silicon tube were removed after eight weeks and examine the form and number of myelinated tibers as well as the quanlity of the myelinated sheath Results In the left sides regeneration axon were tuned into the silicon tubes containing the ATP and there were not axon regeneration in the silicon tube contained the ATP and there were not axon regeneration in the silicon tube contained ATP+ Suramin In the right sides the regeneration axon were found only three tubes contained suramin and seven tubes contained physiological saline Conclusions The results demonstrated that the suramin inhibited the axon reduction of the extracellular ATP completely

BACKGROUND:Dynamic hip screws have been considered as a classic method for intertrochanteric fracture. However, migration of the hip screw resulting in cut-out of the femoral head remains the most common mechanical failure, which requires secondary surgery. OBJECTIVE:On the basis of the traditional dynamic hip screw, we modified the lag screw, designed new internal fixation system as cemented dynamic hip screws to explore the feasibility and the biomechanical properties for the treatment of osteoporotic intertrochanteric fracture. METHODS:A total of 24 hip samples were harvested from fresh cadavers with osteoporosis. Bone density was measured. According to the standards, the specimens were made into intertrochanteric fracture models of AO31-A1 type. Of each specimen, one side implanted with cemented dynamic hip screws served as experimental group, and another side implanted with traditional dynamic hip screw served as control group. Axial compression, twisting and fatigue load biomechanics were tested. Their biomechanical functions were compared. RESULTS AND CONCLUSION:Stress intensity, axial stiffness and horizontal shear stiffness were higher in the experimental group than in the control group (P<0.05). At torsion angle of 3°, torsional moment was higher in the experimental group than in the control group (P<0.05). Fatigue load was higher in the experimental group than in the control group (P<0.05). Results suggested that cemented dynamic hip screw internal fixation system in the treatment of senile osteoporotic intertrochanteric fracture can effectively enhance the hip screw holding force and prevent femoral cutting. Biomechanical property, stiffness, endurance resistance and stability of cemented dynamic hip screw are better than traditional dynamic hip screw.

BACKGROUND: Injured nerve can regenerate through end-to-side anastomosis and obtain partial physiological function in animal experiment. As an immuno-suppressivedrug, FK506, which is characterized by promoting neural growth and functional recovery, is paid widely attention to.OBJECTIVE: To investigate the effect of FK506 on functional recovery of peripheral nerve after end-to-side anastomosis.DESIGN: Randomized controlled animal study.SETTING: Department of Operation Surgery, Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology.MATERIALS: The experiment was completed in the Department of Operation Surgery, Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology in March 2005. Totally 26female Wistar rats were selected and divided into experimental group and control group with 13 in each group.METHODS: Peroneal nerve was transacted on the right side of all the animals, the proximal end of peronieal nerve was turned back and ligated, and the distal end was sutured to the side of tibial nerve with perineurial window. No operation was done on the left side. FK506 was injected in the right tibial muscle (2 mg/kg· d), once a day within two weeks in the experimental group, and saline was used in another group as contrast.MAIN OUTCOME MEASURES: Three months afteroperation, the bilateral common peroneal nerve and the tibial muscle were taken for electrophysiological and histological examination, and the number of common peroneal nerve fiber, area of tibialis anterior muscle fiber of transverse section and muscle wet weight of tibialis anterior muscle were measured. The results were expressed with the ratio between right side and left side (i.e.recovery rate).RESULTS: Totally 26 rats entered the final analysis. ① Results of histological examination: Both ratio of number of nerve fiber and ratio of area of muscle fiber in the experimental group were higher than those in the control group (0.734±0.143, 0.412±0.119; 0.628±0.125, 0.432±0.135; P ＜ 0.01,0.05). ② Results of electrophysiological examination: Recovery rate of action potential, recovery rate of single muscular contractility and recovery rate of tetanus contractility in the experimental group were higher that those in the control group (P ＜ 0.05). ③ Ratio of wet weight in the experimental group was higher than that in the control group (0.765±0.101,0.513±0.116, P ＜ 0.05).CONCLUSION: FK506 injected into targeted muscle can promote growth and functional recovery of peripheral nerve in end-to-side anastomosis.

In order to clarify the limitative factors in the management of severe acute pancreatitis (SAP) especially the problems of the complicated multiple organ failure (MOF),70 cases of SAP,of which 17 were complicated with MOF,admitted to our hospital in the past 16 years were reviewed.The overall mortality rate of the series was 20.0% (14/70),and the death of 12 cases out of the 14 was associated with MOF (85.7%) and that of the other 2 with single organ failure (14.3%).MOF occurred in 17 cases with a mortality rate of 70.0%.Two patterns of MOF manifestations identified:A rapid single-phase of MOF was found in 7 cases.It developed rather early after the onset of SAP and was associated with severe pancreatic necrosis and early shock.And a delayed two-phaseof MOF was seen in 10 cases.It developed progressively with a lagging interval and from the pancre-atic necrosis and subsequent infection.The clinical manifestations of MOF were characterized by a severe and systemic inflammatory response.It is believed that the systemic inflammatory response trigged by the septic material released from the pancreatic necrotic focus seems to be the pathological channel to link SAP with MOF.