In order to investigate the histological and stereological change of the rapidly expanded skin tube, 15 Japanese Long Ear Rabbits were divided into 3 groups: (1) Rapid expansion group, injecting once a day for 7 days; (2) Routine expansion group, injecting every 3 days for 21 days and (3) Control group, no expander implanted. The results showed that: in the rapid expansion group, the thickness of the epidermis and dermis were both increased, fibroblast proliferation was active, a large amount of new capillaries was observed, the collagen fiber was in loose type, and the mitochondria and rough endoplasmic net of epithelial cell were increased. In the routine expansion group, similar changes were observed. The vascular density and volume fraction were significantly higher in rapid expansion group than those in the control group (P lt; 0.05). It was concluded that the rapid expansion of skin tube was feasible.
The canine saphaneous skin flap was used as a model in this experiment. The cutaneous autograft would give long-term survival, whereas the allograft without pretreatment would only survive 10. 2±1.9 days from its transplantation. If the pretreatment consisted of the use of immunosuppressive agent as PHA or infusion of dexamesone, the survival days of the allografts could be prolonged to 15.1±2.5 and 13.7±2.8, respectively(Plt;0.01). The histological examination gave the evidence that drug perfusion delayed the rejection.
Superficial cervical artery skin flap is widely used in clinical practice. In order to inprove the outcome of the flap in clinic, eleven cases of skin defect of scalp who were treated with the flap was discussed. After operation, the donor area healed but there was no hair growth on recipient area. Among them, six cases occurred partial necrosis of skin flaps. In order to avoid these problen, the relevant solution discussed as follows: 1. Handle well the pedicle of the skin flap to prevent the interference with venous returm. 2. Adhere strictly to indications. 3. Apply skin expander to obtain "extra" skin, then carryout the tranfer of skin flap and 4. Better use the skin flap with residual hair.
OBJECTIVE To study the biocompatibility of skin reproductive membrane. METHODS According to ISO’s standards, the extractions of the skin reproductive membrane were prepared, and the acute systematic toxicity test, primary skin irritant test, cytotoxicity test, gene expression of type I collagen and fibronectin were detected to evaluate the biocompatibility of skin reproductive membrane. RESULTS All of those tests showed negative results. CONCLUSION The skin reproductive membrane has excellent biocompatibility in the level of the systematic, cellular and molecular biology.
Objective To provide theoretical evidence for clinical application of the epidermal stem cells after an investigation on changes of the epidermal stem cells during the survival process after the fullthickness skin autograft. Methods On the backs of 42 Wistar rats, orthotopic transplantation models (1.5 cm×1.5 cm) of the fullthickness skin autograft were made. According to the time of the specimen taking, at 1, 3, 5, 7, 14, 21 and 30 days after operation, the rats were randomly divided in 7 groups (Groups 1-7). Specimens taken in each group before operation were used as controls. At each time point, the gross observation was made on the transplanted skin flaps, from which the skin tissues were harvested at each time point before and after operation. The routine pathological and the immunohistochemical examinations were performed on the specimens, which were stained by HE and were observed for immunohistochemical changes and the changes in the cells positive for integrinβ-1 and p63. Results All the fullthickness skin autografts survived 3 days after operation except the skin autograft in 1 rat in both Group 5 and Group 6, which was infected around the transplanted skin flap. In Groups 1-4, cell edema, inflammatory cell infiltration, and increased fibrocytes were observed. In Groups 5-7, the maturity degree of the epithelial cells became higher and higher, and the fibrocyte proportion was lowered. In each group the cell positivity rate for integrin β1 was lower than the cell positivity rate for p63. The positive cells were arranged in disorder, distributed into the layers of the epidermis and gradually concentrated in the basal layer of the epidermis and the bulge of the folliculus pili. The positive cells were also found in the other layers of the epidermis.The positive cells were gradually decreased in number, and reached the lowest level in Group 2. There was a significant difference in the above variables in Groups 1,2,3,5,6 and 7 between before and after operations (P＜0.05). Conclusion During the survival process of the fullthickness skin autograft, the proportion of theepidermal stem cells is gradually decreased at first; Then, the proportion isgradually increased, even beyond the normal level; finally, the proportion is decreased again. The distribution of the epidermal stem cells appear in disorder, almost distributed in the layers of the epidermis; finally, the almost normal distribution can be found.
The experiment performed on domestic pig, was designed to investigate the architecture of the stretching skin and the effect of tension traction on the wound closure. An 7 cm x 3.5 cm was drawn at a standard position. Drawing horizontal and vertical lines on the traction area, points of 1 cm apart were tattooed on the lines. A traction force measuring device was used to draw the wound edges together. Measurements of the distances between the points were made. An 7 cm x 10 cm wound was made on identical sites of each hind leg. In the experiment the traction tension was applied on the edges of wound immediately after the wound debridement. The results showed the stretched distance in the two areas was 5-7 times the width of the wound. The gain of skin from traction was 61-89 percent in the width of the wound. The wounds from traction five days could be closed 5 days after traction. It was concluded that the skin which could be used for traction was abundant. Wound closure with the skin traction technique had many advantages, such as rapid decreasing the size of wound and early closing of wound.
Objective To establish a method of constructing skin-equivalents (SE) by the hair follicle stem cells (HFSC) and the fibroblasts. Methods The K19 immunostainning was employed to localize the HFSC in the human scalp from the cosmetic surgery. The isolated HFSC through the enzyme digestion were seeded on the dermal equivalent (DE) formed by polymerization of the fibroblasts and collagen. After being cultured between the air-liquid interface for 14 days, SE were harvested and used for an evaluation. Results HFSC were located mainly in the outer root sheath in the hair follicle. Based on DE, the growing HFSC could build a fullydeveloped and multilayered epidermis with the basal membrane formedb etween the epidermis and the dermis. The fibroblasts were active and spread evenly in the collagen matrix. Conclusion The hair follicle stem cells located in the outer root sheath can be successfully used to construct skin-equivalents in vitro and have a promising clinical use in the treatment.
Objective To compare the effect of the composite skin graft consisting of spl it-thickness skin grafts (STSGs) and porcine acellular dermal matrix (PADM) with STSGs only, and to histologically observe the turnover of the PADM in rats. Methods Twenty female Sprague-Dawley rats, weighing 200-225 g, were included. The size of 4.0 cm × 2.5 cm PADM was implanted into hypoderm of the left side of Sprague-Dawley rats’ back. After 10-14 days, the size of 4.0 cm × 2.5 cm full-thickness skin defects were made on the left to expose the PADM under the skin and the same size of full-thickness skin defects were made on the right of the rats’ back. The excised full-thickness skin was made to STSGs about 0.2 mm by drum dermatome. The defects were grafted with composite skin (STSGs on the PADM, experimental group) and STSGs only (control group). The survival rate, the constraction degree of grafts, and the histological change in grafts area were observed at 2, 4, 8, and 20 weeks after operation. Results At 2 weeks after STSGs (0.2 mm) placed on vascularized PADM, STSGs and PADM adhered together and the composite skin had a good survival. The control group also had a good survival. Histological observations showed that STSGs and PADM grew together, neutrophil ic granulocytes and lymphocytes infiltrated in the PADM and some macrophages around the PADM. Fibrous connective tissues were filled under the STSGs in control group. At 4-8 weeks after transplantation, the composite skin had a good survival and the composite skin was thick, soft, and elastic. STSGs survived almost totally in control group, but the grafts were thin. Histological observations showed that inflammatory reactions of PADM faded gradually in experimental group; scar tissues formed under the STSGs in control group. At 20 weeks after transplantation, composite skin was flat, thick, and elastic in experimental group, but the STSGs were thinner and less elastic in control group. Histological observations showed that histological structures of the PADM were similar to the dermal matrix of rats, and the results showed that the collagen matrix of PADM was gradually replaced by the rats’ collagen matrix. Scar tissues were filled under the STSGs in control group. Wound heal ing rates of experimental group were lower than those of control group at 4 and 8 weeks (P﹤0.05); wound contraction rates of experimental group had lower tendency than those of control group, but showing no significant differences (P gt; 0.05). Conclusion? Coverage wound with composite skin which composed of STSGs and PADM could improve wound heal ing qual ity; the composite skin is thicker and better elastic than STSGs only. The collagen matrix of PADM is gradually replaced by rats’ collagen matrix.
Greater omentum was chosen to treat chronic osteomyelitis in 12 cases. The involved bones included cranium in 5, tibia and fibula in 4 and metatarsus in 3. After thorough debridement, all patients had partial defects of bone, skin and soft tissue. The defect was filled with vascularized autogenous greater omentum by anastomosing with the host vessels. Theskin defect was covered with medium-thickness skin graft. After 3～9 years follw-up, no recurrence of osteomyelitis and no abdominal symptoms were observed in 11 cases. The osteomyelitis recurred in 1 case at 4 months after operation and died of squamous carcinoma 1 year later. It was suggested that transfer of vascularizedautogenous greater omentum was valuable in treating chronic osteomyelitis.
Objective To explore the mechanism of full-thickness burn wound healing with autoskin grafting in fault hypodermis wound of granulation excision and to evaluate its effect.Methods By the techniques of clinical observation, histopathology, immunohistochemistry,TEM and FCM,we observed changes of the activity andstructure of grafted skin and the granulation tissue,collagnous fiber,microvessels,the ultramicrostructure of fibroblasts and the expression of basic fibroblast growth factor(bFGF) in the base of autoskin grafting in fault hypodermis wound in burned adult minipigs(Group A), and compared with traditional method of autoskingrafting on the basilar fibrous tissue wound of scraped partly granulation being(Group B) and control group (Group C, without treatment except de-fur).Results The grafted skin survived after 3 days of operation, and it had less injury and higher proliferative index(PI) in group A than in group B. The hyperplasiaof granulation tissue and vascular endothelial and the expression of bFGF were more evident in group A. After 5 days, the proliferation of endothelial cells and granulation and the protein synthesis of fibroblasts were more active in groupA, and at this moment, fresh collagen appeared and proliferated more actively in group B. After 7-14 days, epidermic structure and dermic microvascular density became normal gradually, the granulation on grafting base matured and transformed into fibrous connective tissue in group A. The same change deferred about 2 days in group B. After 21 days, the above pathologic change in group A was less than that in group B. After 3060 days of operation, Group A achieved much less contraction and transfiguration than Group B, and the grafted skin was tender and movable. Conclusion Autoskin grafting in fault hypodermis wound of granulation excision has a better effect than traditional operation.