Objective To study the relationship between morphological and functional changes of melanocytes and their effect on the graft color. Methods Eighteen black whited guinea pigs were divided into nine groups randomly and biopsied at 1 d, 2 d, 3 d, 7 d, 14 d, 21 d, 28 d, and 90d after skin grafting, respectively. Then skin spliting and Dopa reaction techniques were used to demonstrate melanocytes. And computer assitant imagine analysis system was applied to observe and quantitate the morphological changes of melanocytes at various time points in three postoperative months. Results During three days after grafting, resulting from the surgery wound and shortage of blood and oxygen supply, the processes of the melanocytes broke off, accompanied by reduction of whole dimension of the cells, size as well as number of the processes. The indices above returned to the normal level between second week and third week after grafting. It was an evident characteristic that number of melanocytic processes became shorter and stouter in the end of the experiment. conclusion Functional changes of melanocytes in the skin grafts are in accord with their morphological changes. Compared to those in the sizes of melanocytes, changes in the processes of the cell are more sensitive in reflection of function of melanocytes. The shorter and stouter processes of melanocytes in the end of the experiment are suitable to the smaller epidermal melanin unit and more efficient in transformation of melanin into the keratinocytes.

Objective: To study the role of vascular endothelial growth factor (VEGF) during angiogenesis in oral squamous cell carcinoma (SCC).Methods:Surgical specimens from 45 patients with oral SCC were examined for VEGF expression and microvessel density(MVD) by immunocytochemical staining. Anti-VEGF polyclonal antibody was used to determine VEGF expression and anti-CD 34 monoclonal antibody was used to determine MVD. Results:①VEGF protein was mainly found in cytoplasm of cancer cells and in few endothelial cells. Stained microvessels were mainly distributed in the regions of the connective tissue near the cancer nest;②there was a close positive correlation between MVD and VEGF expression;③SCC with high MVD or high VEGF level was mostly found with metastasis in cervical lymph node (P