The reports on the peripheral nerve injury in the internati onal journals in 2003 included the anatomical study on surface landmarks to loca te the thenar branch of the median nerve (Wilhelmi etc.) and management of iatro genic injury to the spinal accessory nerve (Chandawarkar etc.). Gu, Kim, and Tun g, etc. reported the nerve transfers, which were effective in repairing the uppe r brachial plexus injury. The partial bundles transfer of ulnar nerve (Oberlin s method) was one of the nerve transfer operations. The functions of both biceps and brachial muscles were reported to be repaired simultaneously for elbow flex ion reconstruction in the management of brachial plexus injury. Bertellis, etc. reported that the brachial plexus avulsion injury was repaired with nerve transf ers and nerve grafts which were directly implanted into the spinal cord and part ial recovery of shoulder and elbow movements were achieved. The incidence rate o f birth-related brachial plexus injury was 0.06% to 0.26%. 85% to 90% of the patients could spontaneously restore their function (Richter etc.), but a f ew patients who could not should be evaluated 6 months after the birth to decide whether they needed microsurgical nerve repair or not. The suitable time for op eration was reported to be 6 months to 9 months after birth. The patients must b e examined thoroughly and their follow-up information must be recorded, and the y could accept the hyperbaric oxygen therapy.

Objective To study the protocol that rat bone marrow stromal cells (BMSCs) can be induced to differentiate into Schwann cell-like in vitro. Methods BMSCs were treated with beta-mercaptoethanol followed by retinoic acid and cultured in the presence of forskolin,basic-FGF,PDGF and heregulin. The positive percentages of GFAP,S-100 protein expression were measured by immunocytochemistry SABC staining. Results After the induction,BMSCs displayed morphologies of Schwann cell,such as ellipsoidal cell bodies and fences-like array,with two or three sligh cell processes. The positive percentages of GFAP protein expression was from 42.5% to 68.7%,S-100 was from 39.6% to 60.2%. Conclusions Rat BMSCs could be induced to Schwann cell-like by beta-mercaptoethanol,retinoic acid,forskolin,basic-FGF,PDGF and heregulin

Objective To evaluate the effectiveness of using induced bone marrow stromal cells into a tissue-engineered bioartificial nerve on bridging a 10mm long sciatic nerve defect Methods Twenty-eight F344 female rats weighing 160～200 g were randomly divided into four groups of nerve grafting,with 7 rats in each group A group:PLGA tubes with an intrinsic framework were seeded with syngeneic bone marrow stromal cells induced 5 days;B group:PLGA tubes with an intrinsic framework were seeded with syngeneic Schwann cells;C group:PLGA tubes were only filled with an intrinsic framework;D group:autografts Three months later,a series of examinations were performed,including:electrophysiological methods,Walking trace's analysis,hisotological staining of nerves,S-100 and neurofilament immunostaining and axon counts Results At 12 weeks after the operations,all the examinations of A group were better than C group( P 0.05). Conclusions Induced bone marrow stromal cells as seeding cells for peripheral nerve tissue engineering were used to repair 10mm nerve gap,the outcome was satisfied.

Objective To explore whetherthere exists Schwann-cell derived neurotrophic factor (SDNF) receptor in peripheral nerve. Methods SDNF binding sites in rat sciatic nerve were studied using 125 Ⅰ-SDNF as a radioligand (radioligand binding assays). Results There exists SDNF specific binding sites in peripheral nerve,and the specific binding sites have the following characteristics:①The equilibrium dissociation constant (kd) was (93.11?0.52) pmol/L.②The maximal binding capacity (B max ) of SDNF was (8.91?0.26)fmol/mg protein.③Saturation.④Kinetic studies revealed that the association rate constant (K 1) was (3.91?0.63)?10 7M -1 ?min -1 and the dissociation constant (K -1 ) was (3.38?0.54)?10 -3 min -1 .⑤Specific studies of SDNF binding sites showed that the binding sites were highly specific for SDNF. Conclusion SDNF receptor exists in the peripheral nerve and the peripheral nerve may be one of target tissues of SDNF.

Objective Investigate the degradation process of polyactic acid (PLA) filaments within peripheral nerves and its adverse effects on peripheral nerve. Method Bilateral sciatic nerves of 20 SD rats were exposed, and PLA filaments were implanted among the fascicles at one side, while Vicryl filaments were implanted into the contralateral nerve as control. The filaments and nerves were harvested at 1,4,8 and 12 weeks postoperatively, and inspected by macroscopy, light microscope and transmission electron microscope. Results The degradation occurred not only on the surface but also inside the PLA filaments after they were implanted into the sciatic nerve. PLA fragments still could be found at the end of this study. During the degradation of PLA filaments, macrophages invaded into the filaments and exhibited active phagocytosis. There were mild degree infiltration of lymphocytes and fibroblast around the filaments during their degradation. However, the structure of peripheral nerve didnt change significantly. Conclusion It takes more than 12 weeks that PLA filaments degrade in peripheral nerve completely. Mild nonspecific inflammation develops following the implantation of PLA filaments into peripheral nerve, but it has no adverse effects on nerve.

Objective Investigate the toxicity of polylactic acid,polyglacolic acid and chitosan on peripheral nerves,so as to detect the polymers with good biocompatibility to fabricate the scaffold of tissue engineered nerve Method Fifteen Sprague Dawley rats were divided into 3 groups randomly;polylactic acid,polyglacolic acid and chitosan were implanted into the sciatic nerves respectively.7 weeks later,the nerves with polymers were harvested and inspected by macroscopy and light microscope. Results There was mild hypertrophy of fibrous connective tissue within the nerves in each group.However,the nerve fibers were intact The polymers were surrounded by a pseudocapsule,and lymphocytes and macrophages infiltrated.The pseudocapsule coating chitosan was the thickest. Conclusion polylactic acid, polyglacolic acid and chitosan have no toxic effect on peripheral nerves.

Objective To look for an ideal substance to repair large gap of nerve defect after injuries by culture,population of Schwann cells(Scs)and preparation of acellular allogenous nerve grafts with chemical extraction. Method The double adhesion culture and Arab c to prohibit the fibroblast growth were used to achieve high purified Scs;detergents:Triton X 100 and sodium deoxycholate were used to achieve acellural nerve grafts (ANG);and finally the Scs were micro injected into the acellural nerve grafts and the consequence studied Result By the way above,high purified Scs and the ANG was acquired,which can integrated each other well Scs can survived and transformed to aline in vitro Conclusion ANG populated isogenous Scs may be an ideal substance to repair the large gap of nerve defect after injuries

Objective To analyse the molecular structure of Schwann cell derived neurotrophic protein (SDNP) by matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI TOF MS) Methods The purity of SDNP was digested byTPCK trypsin and detected by MALDI TOF MS, mass mapping was determined and partial sequences of the protein have neen analyzed by the mass data of fragment ion peaks in the fragmentation analysis and structural TOF MS (FAST) spectra The primary partial structure of SDNP was identified by searching the protein databases Results The integrity SDNP in peak detected by MALDI TOF MS has 66?10 3 MW and higher purity, because no other peaks exists except double charge peak The mass mapping of many peptides was determined and 8 peptides of them have been retrieved in MS Fit database, there is not the same protein in database Hypothetical protein has 5 peptides homology with the sample (62%) FAST spectra of 2305 Da shows the primary partial structure of SDNP after searching the protein MS Tag database Conclusions The molecular weight of SDNP detected by MALDI TOF MS is 66?10 3, The sequence of partial amino acid is EPVKKVTNSRRAKRTKPNGHIAN

Objective To investig ate the expression of Schwann cell derived fa ctor （SDNF） in normal or under the condi tion of different injuries on the sciati c nerves of rats. Methods Sevent y-five S D rats were divided into three groups ac cording to different injuri es including transection， transection fo llowed by epineurial suture， and crush. Ten normal rats were treated as control. T he immunohistochemistry of both sciatic nerve and spinal cord were performed at 5，7，14，30，60 days after operation respec tively. Result （1）lower levels o f SDNF were detected in normal sciatic nerve， t he whole white matter and the laminae Ⅲ～ Ⅴ of dorsal horn of spinal cord. （2）In g roup transection， the SDNF levels reache d a maxium at 14 days after operation in proxi mal segment， at 7 days in distal segment ， and at 5 days in spinal cord. There ap peared a highest expression in related t issue of both group crushing and group s uturing at 60 days after operation. （3）SD N F staining of dorsal horn ipsilateral to the nerve lesion was stronger than that of contralateral. There was a transient expression in spinal motor neurons ipsi lateral to nerve lesion at 5 days in gro up crushing and group transection and at 30 days in group suturing. Conclusi on （1）There is a weaker expression i n norma l sciatic nerve and spinal cord. （2）The expression of SDNF varies with the diffe rent nerve lesions. （3）Significant quant ities of SDNF are released from Schwann cells after nerve lesion， and SDNF is then available to the axon of the lesioned neurons which may promote neuro n repair.

The upper limbs of 23 adult cadavers were dissected and the internal structures of the median nerve were studied for microsurgery of the nerve.Under operative micros- cope(24X),the median nerves of 20 cadavers treated with 10% acetic acid were dissec- ted.The median nerves of the remaining three were cross-sectioned,inch by inch,and stained with Sudan Ⅲ for microscopic observation.Microscopic ptotographs were taken to visualize the intra-neural topography of motor bundles or bundle groups. 1.The morphology,topographic relationships,size and number of bundles of the median nerves were observed under microscope and were recorded. 2.At the level of the arm and forearm,the nerve trunk and its internal bundles appear to twist to a certain degree in the way of external rotation from the distal to proximal. 3.The motor bundles of the thenar muscles emerge at the level about 40.1mm below the styloid process of radius.They enter the nerve trunk anteriorly on the radial side,and run upward at the Rower part of the forearm,and continue postero-laterally and appear as a admixture of sensory and motor nerves.At the mid-portion of the fore- arm,they are situated posteriorly,while at the level of antecubital fossa and above, they occupy the central position and finally most of the bundles join the medial head of the median nerve. 4.The motor bundles that supply the flexor muscles of the forearm are located anteriorly and posteriorly in separate portions after entering the nerve trunk.At the level of the arm,these two portions of median nerve are mixed bundles but motor nerve fibers predominate. 5.The fundamental method of funicular suture were discussed in relation to the intra-neural topography of the median nerve.