| The term of spinal cord injury refers to various kinds of injuries in the spinal cord. SCI can occur from either trauma or disease to the vertebral column or the spinal cord itself. Most spinal cord injuries are the result of trauma to the vertebral column. These injuries can affect the spinal cord's ability to send and receive messages from the brain to the body systems that control sensory, motor, and autonomic function below the level of injury. Depending on the location and severity of the injury, the body can be affected in a myriad of ways. Typically, the CNS above the injury site continues to function as they always have and those below the site do not. In the last century, major advances in understanding fundamental aspects of the nervous system have paved the way for the development of treatments for injuries and diseases in this complex organ. In particular, repair of the central nervous system (CNS) following injury has been a long-standing and vitally important area of neuroscience. For example, following severe spinal cord injury, descending neural systems in the brainare disconnected from motor circuitry in the spinal cord, and paralysis results below the lesion. The subsequent degree of axonal regeneration and recovery of function below the lesion depends on both ontogeny and phylogeny.The failure of axons to regenerate in the adult central nervous system has been attributed to a variety of factors including a non-permissive environment such as the glial scar, the presence of inhibitory factors and the lack of trophic support. Several strategies have been developed to rebuild the injured spinal cord in animals such as adding growth factors, providing bridges of embryonic tissue, artificial implants or peripheral nerves, and transplanting Schwann cells or macrophages. In recent years, several recent studies have highlighted the potential therapeutic role of olfactory ensheathing cells (OECs) for the repair of spinal cord injuries. Studies have shown that transplants of OECs into lesions in CNS are able to stimulate the growth of axons and in some cases restore functional connections.The present study constructed a recombinant adenoviral vector (Ad), with the whole length human BDNF gene from the source of gift plasmid pcDNA3-BDNF, and transfered the BDNF gene into the OECs by infection of Ad-BDNF. The OECs can transcript and express BDNF protein to survive the primary cultured neurons from the spinal cord. After transplanting of the BDNF gene-modified OECs to the transected site in SCI, the regeneration of axons and the recovery of function in SCI rats were observed.The results and conclusions showed as follows:1. Isolation, Purfication and culture of OECsOlfactory nerve and glomerular layers from neonatal rats bulbles were dissociated and cultured in DMEM/F-12 medium, and OECs were incubated in the medium including cytosine arabinoside within 24-48h and BPE within 5 days. When the cells were confluent, they were trypsinized and purified by immunoaffinity of anti-NGFR. Tow weeks later the OECs dominated the cultures and revealed tow types of form: the fusiform and multipolar cells, while they were stained with SI00 protein and NGFR positively. The OECs can be purified at 98 percent in this way and the period of purification was shortened.2. Improvement of the transected rat model.Comparing other SCI models, we preset 3-0 suture anteriorly and transversely to the spinal dural sheath, and then cut the cord and took out the line. This approach relieved the irritation of surgery operation so as to analyse the functional recovery after the operation.3. Construction of recombinant adenovoral vector Ad-BDNF.To obtain Ad-BDNF, the expression cassettes CMV-BDNF-BGHpA were cut from the plasmid pcDNA3-BDNF and inserted into El-substituded adenovirus pH A ElsplA. After cotransfection into 293 cells with adenoviral vector pJM17, the recombinant adenovirus Ad-BDNF was propagated in 293 cells via homologous recombination. We obtained the human recombinant adenovirus Ad-BD...
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