Objective To compare and research the process of woundhealing in occlusive moist environment and dry environment on the skin donor site. Methods The wound healing of adult skin donor site was studied by clinical observation, histological and electromicroscopical examinations on the operative day and the 1st, 2nd, 3rd, 4th, 7th days postoperatively, each skin donor site was divided into two parts: occlusive environment and dry environment. Results The wounds of occlusive moist environment healed faster than those of dry environment; thefibroblasts were more active and activated earlier, revascularization and re-epithelialization happened earlier and more quickly. Conclusion In occlusive environment, more active fibroblasts can accelerate granulation growth; quicker regenerative capillaries bring more nourishment; quicker re-epithelialization accelerates the wound healing.
To determine the state of fibroblast during the process of development of hypertrophic scar (HS), 40 specimens of HS in different periods were collected. The expressions of prolifrating cell nuclear antigen (PCNA) and Ag-protein in nucleolar organizer regions (Ag NORs) as well as the content of total amino acids in the tissues were examined. The hypertrophic scar of 1st and 3rd month old, the expression of PCND and Ag NORs were the highest. In the 9th and 12th month old, althrough PCNA was nearly negative, but the expression of Ag NORs was low. The content of total amino acid was increased gradually as HS developed but the increase of amount of hydroxyproline was markedly slowed down in 9 month old HS. It was suggested that: (1) in the developing process of HS the proecess of overproliferation of fibroblasts was short and limitted in 1-3 months period in the process of wound lealing; (2) the synthesis of collagen was nearly stopped at 6 months, but that of other extracellular matrix such as fibronectin and proteoglycan might be continued to aggregate after 12 months.
For observation of the change of transforming growth factor-beta 1 (TGF-beta 1) gene expression in the process of skin wound healing, the following experiments were performed. Sixteen Wistar rats were chosen. At each side of the rat’s back, a 1 cm x 1.5 cm middle-thick skin wound was made. After 3, 6, 9 and 12 days, the specimens were taken from the wounds. For each specimen, half of it was used for RNA extraction, and underwent dot blotting; and the other half was frozen immediately and underwent in situ hybridization. The probes were dig-labeled PDGF-BB cDNA probe and TGF-beta 1 probe. The results showed that TGF-beta 1 gene was expressed mainly in fibroblast, epithelial cell and capillary endothelial cell. The peak of TGF-beta 1 mRNA content was in the 6th day postoperatively. After that, the content of TGF-beta 1 decreased to normal. It was suggested that TGF-beta 1 gene expression was in close relation with healing process. TGF-beta 1 may play an important regulatory role in the skin wound healing.