2.Therapeutic potential of stem cells in skin repair and regeneration.
Chinese Journal of Traumatology 2008;11(4):209-221
Stem cells are defined by their capacity of self-renewal and multilineage differentiation, which make them uniquely situated to treat a broad spectrum of human diseases. Based on a series of remarkable studies in several fields of regenerative medicine, their application is not too far from the clinical practice. Full-thickness burns and severe traumas can injure skin and its appendages, which protect animals from water loss, temperature change, radiation, trauma and infection. In adults, the normal outcome of repair of massive full-thickness burns is fibrosis and scarring without any appendages, such as hair follicles, sweat and sebaceous glands. Perfect skin regeneration has been considered impossible due to the limited regenerative capacity of epidermal keratinocytes, which are generally thought to be the key source of the epidermis and skin appendages. Currently, researches on stem cells, such as epidermal stem cells, dermal stem cells, mesenchymal stem cells from bone marrow, and embryonic stem cells, bring promise to functional repair of skin after severe burn injury, namely, complete regeneration of skin and its appendages. In this study, we present an overview of the most recent advances in skin repair and regeneration by using stem cells.
Embryonic Stem Cells
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transplantation
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Epidermis
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cytology
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Genetic Therapy
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Hair Follicle
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cytology
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Humans
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Mesenchymal Stem Cell Transplantation
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Regeneration
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Skin Diseases
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therapy
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Skin Physiological Phenomena
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Stem Cell Transplantation
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Tissue Engineering
3.Posttraumatic stress and immune dissonance.
Chinese Journal of Traumatology 2008;11(4):203-208
Stress or neuroendocrine response usually occurs soon after trauma, which is central to the maintenance of post-traumatic homeostasis. Immune inflammatory response has been recognized to be a key element both in the pathogenesis of post-traumatic complications and in tissue repair. Despite the existence of multiple and intricate interconnected neuroendocrine pathways, the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system have been considered to be the most important in trauma. Although the short-term and appropriate activation of these stress responses is vital to the host's adaptation, prolonged duration and exaggerative magnitude of their activity leads to deleterious effects on immune function in trauma, causing immune dissonance. The overall appropriate and controlled activation and termination of the neuroendocrine responses that mediate the necessary physiological functions involved in maintaining and restoring homeostasis in the event of trauma are of critical importance. This review will describe the effects of some important neuroendocrine responses on immune system. Present evidences indicate that the neuroendocrine and immune systems form a cohesive and integrated early host response to trauma, and identify areas for further research to fully elucidate the regulatory role of neuroendocrine system in trauma.
Humans
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Hypothalamo-Hypophyseal System
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physiology
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Immune System
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physiology
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Parasympathetic Nervous System
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physiology
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Pituitary-Adrenal System
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physiology
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Stress Disorders, Post-Traumatic
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immunology
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physiopathology
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Sympathetic Nervous System
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physiology
8.Evaluation of multislice computed tomographic perfusion imaging and computed tomographic angiography on traumatic cerebral infarction.
Fang-hong XU ; Wei-jian CHEN ; Yun-jun YANG ; Yu-xia DUAN ; Feng-li FU
Chinese Journal of Traumatology 2008;11(3):186-189
OBJECTIVETo evaluate the application value of multislice computed tomographic perfusion imaging (MSCTPI) and multislice computed tomographic angiography (MSCTA) on traumatic cerebral infarction.
METHODSMSCTA was performed on 10 patients who were initially diagnosed as traumatic cerebral infarction by normal conventional computed tomography (NCCT), among whom, 3 patients were examined by MSCTPI simultaneously. Reconstructed images of the intracranial artery were made with techniques of maximum intensity projection (MIP) and volume rendering (VR) from MSCTA scanning data. Then the graph of function of four parameters, regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), mean transit time (MTT), and time to peak (TTP), acquired by the perfusing analysis software was obtained.
RESULTSAmong the 10 patients with traumatic cerebral infarction, 6 showed complex type on NCCT, which depicted abnormality on MSCTA, and 4 showed simple type on NCCT, which had negative results on MSCTA. Among the 4 patients with abnormal great vessels, 2 suffered from stenosis or occlusion of the middle cerebral artery, 1 from spasm of the anterior cerebral artery, and 1 from spasm of the vertebral-basal artery. The image of MSCTPI of 1 patient with massive cerebral infarction on the right cerebral hemisphere confirmed by CT was smaller than those of the other patients, which showed occlusion of the ipsilateral middle cerebral artery on MSCTA. Among the 6 patients whose MSCTA showed no abnormality, 4 showed simple infarction and 2 showed complex infarction. The infarction focus of 5 patients occurred in the basal ganglia and 1 in the splenium of corpus callosum. Among the 2 cases of small cerebral infarction volume on NCCT, one was normal, the other showed hypoperfusion on MSCTPI and was normal on MSCTA.
CONCLUSIONThe combination of MSCTPI and MSCTA is very useful for evaluating the change of intracranial artery in ischemic regions and assessing the cerebral hemodynamic information of traumatic cerebral infarction.
Adolescent ; Adult ; Brain Injuries ; complications ; Cerebral Angiography ; methods ; Cerebral Infarction ; diagnostic imaging ; etiology ; Child ; Female ; Humans ; Male ; Middle Aged ; Tomography, X-Ray Computed ; methods
9.Implanting hydroxyapatite-coated porous titanium with bone morphogenetic protein-2 and hyaluronic acid into distal femoral metaphysis of rabbits.
Lei PENG ; Wei-guo BIAN ; Fang-hui LIANG ; Hua-zi XU
Chinese Journal of Traumatology 2008;11(3):179-185
OBJECTIVETo assess the osseointegration capability of hydroxyapatite-coated porous titanium with bone morphogenetic protein-2 (BMP-2) and hyaluronic acid to repair defects in the distal femur metaphysis in rabbits.
METHODSPorous titanium implants were made by sintering titanium powder at high temperature, which were coated with hydroxyapatite by alkali and heat treatment and with BMP-2 combined with bone regeneration materials. And hyaluronic acid was further used as delivery system to prolong the effect of BMP-2. The implants were inserted into the metaphysis of the distal femur of rabbits. The animals were killed at 6, 12 and 24 weeks to accomplish histological and biomechanical analyses.
RESULTSAccording to the result of histological analysis, the osseointegration in BMP-2 group was better than that of the HA-coated porous titanium group. In push-out test, all the samples had bigger shear stress as time passed by. There was statistical difference between the two groups in 6 and 12 weeks but not in 24 weeks.
CONCLUSIONHydroxyapatite-coated porous titanium with BMP-2 and hyaluronic acid has a good effect in repairing defects of distal femur in rabbits, which is a fine biotechnology for future clinical application.
Animals ; Biomechanical Phenomena ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; pharmacology ; Coated Materials, Biocompatible ; Durapatite ; Femur ; surgery ; Hyaluronic Acid ; pharmacology ; Osseointegration ; physiology ; Porosity ; Prostheses and Implants ; Rabbits ; Titanium ; Transforming Growth Factor beta ; pharmacology
10.An experimental study of nerve bypass graft.
Chinese Journal of Traumatology 2008;11(3):175-178
OBJECTIVETo study the use of a nerve ''bypass'' graft as a possible alternative to neurolysis or segmental resection with interposition grafting in the treatment of neuroma-in-continuity.
METHODSA sciatic nerve crush injury model was established in the Sprague-Dawley rat by compression with a straight hemostatic forceps. Epineurial windows were created proximal and distal to the injury site. An 8-mm segment of radial nerve was harvested and coaptated to the sciatic nerve at the epineurial window sites proximal and distal to the compressed segment (bypass group). A sciatic nerve crush injury without bypass served as a control. Nerve conduction studies were performed over an 8-week period. Sciatic nerves were then harvested and studied under transmission electron microscopy. Myelinated axon counts were obtained.
RESULTSNerve conduction velocity was significantly faster in the bypass group than in the control group at 8 weeks (63.57 m/s+/-5.83 m/s vs. 54.88 m/s+/-4.79 m/s, P<0.01). Myelinated axon counts in distal segments were found more in the experimental sciatic nerve than in the control sciatic nerve. Significant axonal growth was noted in the bypass nerve segment itself.
CONCLUSIONNerve bypass may serve to augment peripheral axonal growth while avoiding further loss of the native nerve.
Animals ; Male ; Neural Conduction ; Neuroma ; surgery ; Peripheral Nerves ; transplantation ; ultrastructure ; Peripheral Nervous System Neoplasms ; surgery ; Rats ; Rats, Sprague-Dawley