الفهرس 
STEM CELL BIOLOGYOnly 14 pages are availabe for public view
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Abstract
S
tem cells are cell that has ability to divide for indefinite periods often through the life of organism stem cells can differentiate into different types of cells that can constitute an organism, can have characteristic sharp and specialized functions. Such as nerve cells, heart cells and skin cells e.g., stem cells have two distinctive properties.
1. They can make identical copies of themselves for long period of time (self-renewal).
2. Give rise to mature cells that have characteristic morphology.
Discuss the details of:
• Types of stem cells.
• Source of stem cells.
• Role of stem cells in spinal cord injures.
Spinal cord injury occurs when fragments of broken vertebrae and ligaments compress the very soft cord.
Traditional treatment of spinal cord injury seemed frustrating and hopeless because of the remarkable morbidity and mortality, and restricted therapeutic options, recent advances in neural injury and repair, and the progress towards development of neuroprotective and regenerative interventions are basis for increased optimism, neural stem cells have opened a new arena of discovery for the field of regenerative science and medicine.
The regenerative capacity of the central nervous system tissue is extremely limited in all adult mammals, and a number of obstacles to central nervous system regeneration exist. among theses is the response of body by triggering the formation of glial scars after the injury, in an effort to protect the nervous tissue from further damage. this scar tissue prevents foreign cells, including stem cells from regenerating the tissue. efforts done by many research group have met success to overcome this physical barrier.
Stem cells are cell which have the potential differentiate into other types of cells. Stem cells are categorized into two major groups: embryonic and adult stem cells, embryonal stem cells are taken from the embro during the blastocyt stage; these have the potential to differentiate into nearly any types of cells. The mesenchymal stem cells might be maintained in culture over a year (more than 250 passages) retaining their phenotype and ability to differentiate, and the ability of indefinite replication, these cells are also totipotent with normal unaltered genome.
Current treatment for SCI include surgery to stabilize the injury site, high doses of corticosteroids to help limit secondary injury processes and rehabilitative care, preclinical studies with neuroprotective agents (such as minocycline and the Rho antagonist) are encouraging, and clinical trials with these agents will soon begin, while these treatment options any provide benefits, clinical improvements are modest and any patients still face significant neurologic dysfunction and disability.
Stem cells offer several approaches for SCI repair. Stem cell-based therapies could,
1) Replace damaged or diseased cells,
2) Provide a cell-based electrical ”relay” between neurons above and below injury,
3) Ameliorate clinical deterioration and/or facilitate regeneration by providing neuroprotective or growth factors.
4) Play other indirect roles such as promoting neovasculari-zation or providing a permissive substrate for regene-ration of endogenous cells.