Objective To investigate the expression of c-kit in human intermediate-spl it-thickness skin grafts and normal skin, and to recognize the role of c-kit in hyperpigmented process of the skin grafts. Methods The hyperpigmented intermediate-spl it-thickness skin grafts of 16 patients’ face and cervicum 1 year after operation was harvested and the normal skins around the recipient site and the donor site were used as controls. Envision immunohistochemical technique was usedto detect the expression and distribution of c-kit in the skin grafts and in the normal control skins, respectively. Medical image quantitative analysis system was used to quantitate the positive expression index (PI). Results The expression of c-kit was located in endochylema and cytolemma of melanocytes and keratinocytes in the basilar part of epidermis. The positive expression of c-kit was obvious in the intermediate-spl it-thickness skin grafts and blown zone was observed in the basilar part of epidermis; and was not obvious and local in normal control skins. The PI of c-kit in the intermediate-spl it-thickness skin grafts (131 216 ± 19 130) was significantly higher than that in the normal skin around the recipient site (92 958 ± 16 208) and in the normal skin around the donor site (91 306 ± 8 135); showing statistically significant difference (P lt; 0.05). Conclusion The expression of c-kit in intermediate-spl it-thickness skin grafts increases remarkably compared with that in normal control skin. c-kit may play an important adjusting role in the process of hyperpigmentation of skin grafts．
Objective To introduce experiences in the application of island myocutaneous flap for refractory wound in cervicothoracic region. Methods From August 1994 to December 2004, 98 cases of refractory wound in cervicothoracic region were treated; there 42 males and 56 females, aging 2168 years.The course of disease was 3 hours to 13 months. The locations were anterior pectorial region(29 cases), cervical part (28 cases), nuchal region (18 cases), subaxillary and axillary region (15 cases), and thoracic wall (8 cases). The defect area ranged from 6 cm×4 cm to 20 cm×15 cm. According to location, peculiarity and etiological factor of wound, various island myocutaneous flaps were selected: 28 pectoralis major island myocutaneous flaps,34 latissimus dorsi island myocutaneous flaps, 19 trapizius island myocutaneousflaps and 17 rectus abdominis island myocutaneous flap. The sizes of the dissected flap ranged from 8 cm×6 cm to 35 cm×15 cm. Results Of 98 patients, the woundhealed by first intention and the flap survived completely in 92 and the flap necrosed partially in 6. The good function and cosmetic results were obtained without severe complication. Eightythree cases were followed up from 2 weeks to 5 years. The flap obtained satisfactory appearance, good function and cosmetic results. Conclusion Repairing refractory wound in cerviconuchal region may selectpectoralis major island myocutaneous flap, latissimus dorsi island myocutaneousflap, and trapizius island myocutaneous flap; repairing refractory wound on thoracic region may select latissimus dorsi island myocutaneous flap and rectus abdominis island myocutaneous flap. According to specific condition of wound, using suitable island myocutaneous flap for refractory wound in cervicothoracic region may obtain satisfactory functional and cosmetic results.
OBJECTIVE: To investigate the clinical application of subdermal vascular network skin flap pre-fabricated by ultrasonic liposuction in reconstruction of digital avulsion. METHODS: Forty-seven injured fingers of 23 cases were treated from June 1997 to February 2000. Conventional abdominal skin flap was elevated, according to the size of digital avulsion, and subcutaneous fat was removed with scissors. Ultrasonic liposuction technology was adopted, in order to minimize the injury of subdermal vascular vessels, to remove the fat particles close to the vascular network. Finally, the pre-fabricated skin flap was used to repair the digital avulsion. The vascular pedicle was severed in 5 to 7 days after operation. The range of skin flap was 4 cm x 3 cm to 8 cm x 7 cm, and the ratio of length and width was (2 to 3) to 1. RESULTS: All the skin flaps were survived. Twenty-one patients were available for postoperative follow-up for 6 to 24 months. The motion of interphalangeal joint achieved functional recovery, and the sensation of pain, temperature and taction recovered well. CONCLUSION: Ultrasonic liposuction does not obviously injure the subdermal vascular network skin flap, it is a simple and safe method for treatment of digital avulsion.
OBJECTIVE: To investigate the skin regeneration using cultured human keratinocytes with collagen sponge transplanted into thickness wound of nude mice. METHODS: Human foreskin from foreskin ectomy procedures was detached with 0.5% Dispase II. Epidermis sheets were separated from dermis and digested with 0.05% Trypsin into single cell suspension. Keratinocytes were cultured and seeded into collagen sponge during logarithmic growth phase. After 3 days, the keratinocytes-collagen sponge were grafted on full thickness wound of nude mice, compared with simple collagen sponge without keratinocytes. The histological, immunohistochemical examination and electron microscopy were detected. RESULTS: After the epidermal substitute was grafted onto wound, the human keratinocytes were able to further proliferate and differentiate and develop into new epithelia. Compared with the control group, the wound healed earlier and contracted less, epithelia matured earlier, and the collagen fiber was less beneath epithelia. CONCLUSION: Keratinocytes can grow on collagen sponge and migrate onto wound to develop into stratified epithelia and inhibit wound contract. The keratinocyte graft can be used to repair skin defect.
OBJECTIVE: To explore the mechanism of microvascular spasm after limb ischemia-reperfusion. METHODS: The rabbit hindlimb normothermic tourniquet ischemia model was employed. The tendon on the dorsum of the foot was exposed for observation of microvessels. The responses of arterioles on tendon surface to topical application of 10(-6) mol/L noradrenaline (NE) (a vasoconstrictor), 10(-6) mol/l acetylcholine(Ach) (an endothelium-dependent vasodilator) and 10(-4) mol/L nitroglycerin(NTG) (an endothelium-independent vasodilator) were observed at the period of ischemia and following 30 minutes of reperfusion after 2 hours and 5 hours of ischemia by use of intravital microscopy. RESULTS: No significant changes in the responses of arterioles to NE, Ach and NTG were noted following 30 minutes of reperfusion after 2 hours of ischemia compared with pre-ischemia. The constrictor responses of arterioles to NE were still not significantly altered following 30 minutes of reperfusion after 5 hours of ischemia, however, the dilation responses to Ach and NTG were significantly decreased (to Ach P lt; 0.01; to NTG, P lt; 0.05). CONCLUSION: Reperfusion after 5 hours of ischemia significantly impairs both the endothelium-dependent and endothelium-independent vasodilation, meanwhile preserves constrictor responses to NE, these may contribute to the genesis of the vasospasm in ischemia reperfusion.
OBJECTIVE: To review the recent progresses on tissue engineering of skin. METHODS: Recent original articles about tissue engineering of skin were extensively reviewed, which focused on the progresses and major problems concerning the epidermal substitutes, dermal substitutes, cultured-epidermal composite skin graft. RESULTS: Most investigators had come to conclusion that the optimal skin substitute should provide for immediate reconstruction of both the lost epidermis and dermis. The research was mainly focused on how to transplant epidermal cells immediately, preserve their activity and function, and develop the extracellular matrix which could effectively accelerate the function of transplanted cells, induce vascular growth from the wound bed, could be biodegradable, no toxicity and no danger of carrying pathogen. CONCLUSION: The major research trends of tissue engineering of skin should be focused on the study of immediate transplantation of epidermal cells, accelerate wound healing and developing extracellular matrix of dermis.
OBJECTIVE The human epidermal cells were bred on a kind of bio-membrane, the bio-brane, in engineering a kind of new epidermal substitute, the bio-membrane bred cell graft. METHODS Fresh and frozen grafts of biomembrane bred epidermal cells were transplanted into the full-thickness wounds of nude mice and those received simple Bio-brane were served as control. The wounds of the two groups were observed daily and biopsy was taken on the 3, 5, 7, 10, 21 and 35 days respectively. RESULTS Epidermal cells could be cultured in vitro on the bio-membrane reaching the sub-saturated state of 60 to 70 percents. The bio-membrane after being grafted the epidermal cells continued to proliferate and differentiate to form a layer of new epidermis. There was no difference between the fresh and the frozen bio-membranes. CONCLUSION Bio-membrane bred with epidermal cells could be a kind of ideal epidermal substitute.