Humans ; Reconstructive Surgical Procedures ; adverse effects ; Surgery, Plastic

The scar formation and chronic ulcer development are the iain sequelae faced by surgeons in the treatmemt of wounds. Therefore,the prevention and treatment of these sequelae are the main tasks for clinicians.In this paper,the current research concerning both sequelae is reviewed.The authors emphasize that the use of some high technologiesl, such as stem cell technology, clone technology and tissue engineering may bring the hope in improving the treatment and prevention of these sequelae.

Angiopoietin family is a recently discovered type of cellular factors that specifically bind to the TIE-2 receptors located exclusively in endothelial cell membrane. The protein structures of this family members are similar. They can be structurally divided into three domains: an N-terminal region lacking homology to any known structures, an alpha-helical rich coiled-coil segment, and a fibrinogen-like domain. The distribution and biological activity of these factors are different in organism. Angiopoietin-1 as a agonist, mostly locates in close proximity with vascular endothelial cells, keeps the stability of blood vessels, enhances the affinity of vascular endothelial cells with surrounding cells and matrix, decreases the leakage of vessel. Ang-2 is a naturally occurring antagonist of Ang-1, exists in the angiogenic remodeling region and is related to the decrement of the stability of vessel. Ang-3 is widely distributed in multiple mouse tissues, while Ang-4 is expressed only in lung. Although Ang-3 and Ang-4 are structurally diverged from each other, they appear to represent the mouse and human counterparts of the same gene locus. Biological functions of Ang-3 and Ang-4 have not been elucidated yet. Angiopoietin family has potentially clinical applications for incurring illnesses which lead to vessel wound and vascular abnormal development.

The basic concept of gene therapy is to introduce a therapeutic gene into a cell, whose expression can improve to healing of wound. To achieve this goal, the suitable therapeutic gene has been selected and delivered into the reparative cell, which is becoming a focal point works about gene therapy in wound healing. There have been several different therapeutic genes and gene transfer strategies that have been used in models of wound healing. This article discusses several methods that have been used to deliver genes encoding growth factor proteins, stem cells into wounds and the advantages/disadvantages of each approach. We hope a safe vectors system to deliver the effectual transgene in wound healing.

The cytokine-receptor- heparin sulfate functional complex combined by cytokines, cytokine receptors, and heparin sulfate chains formed by concatenation of heparin sulfate proteoglycans (HSPG), an important component of extracellular matrix and modified by some relative enzymes, can regulate the density of cytokine receptors and their intracellular signal transduction. This article focused on the regulatory function of this complex. Many morphological abnormalities and diseases occur when the complex is dysfunctional.

To identify the stem cell islands in regenerated epidermis, the same biopsies used in our previous experiments were used in this study. CD87 immunohistochemicy and PAS staining were used. The scant CD87 positive cells could be found in basal membrane. Also, the positive staining of PAS could be seen in the basal membrane in both normal and regenerated epidermis. No CD87 positive cells were found in the spinous and granular layers. The results indicate that the error in metrology could be excluded from both CD87 immunohistochemicy and PAS staining, and that the stem cell islands may come from the cell reversion in regenerated epidermis.

To gain insight into the mechanisms of an age related difference in ability of wound healing, the characteristics of stem cell differentiation in skins from fetus, child and adult were investiga ted. Integrin ? 1 and keratin 19 (K19) were used as the biochemical markers for stem cells and transit amplifying cells. Biopsies were taken from fetus (22～24week gestational age), children (4～12year) and adults (35～53year). Immunohistochemistry was used. As for the immunostainings of fetal tissue sections, integrin ? 1 and K19 expressions were observed in all epidermal basal cells. In children skin, the ratio of integrin ? 1 and K19 positive cells in the epidermal basal layer was 60%～80%. In adults, the ratio in the epidermal layer decreased. These results indicate that fetal skin epidermis contains a large number of stem cells and transit amplifying cells, and the proportion of stem cells and transit amplifying cells decreases with age after birth, which maybe a reason of the age associated difference in ability of wound healing.

To investigate the effects of basic fibroblast growth factor (bFGF) on intracellular free Ca 2+ of heating injury, and observe the relationship between mitogen activated protein kinases(MAPKs)signal pathways and Ca 2+ mobilization. Cultured human fibroblasts were heated at 45?C for 10min, then divided into four groups :①basic fibroblast growth factor (10ng/ml) treatment; ②preincubated cells with PD98059 (10?mol/L) for 30 min followed by bFGF (10ng/ml); ③preincubated cells with SB203580 (10?mol/L) for 30min followed by bFGF (10ng/ml); ④preincubated cells with PD98059 (10?mol/L) and SB203580 (10?mol/L) for 30min followed by bFGF (10ng/ml). The cells were incubated with fluorescence Ca 2+ dye fluo 3/AM at 37 C for 30min, then measured by using laser scanning confocal microscope. The results showed fluorescent intensity of fibroblast heating injury was weak, the concentration of intracellular free Ca 2+ increased after stimulation with bFGF treatment. PD98059 and SB203580 could induce calcium oscillation. A rapid decrease of fluorescent intensity was observed after cells were preincubated with PD98059 and SB203580 at the same time. bFGF induced an increase of cytoplasmic and intracellular free Ca 2+ concentrations. It is suggested that MAPKs signaling pathway has a feedback regulation for free Ca 2+ mobilization.

Wound repair is a complex biological process and great progresses have been achieved during the last ten years because of the integration of molecular biology and traumatology. However, some fundamental principles in these fields, which are closely related to developmental biology and comparative biology have not been fully understood. Therefore, more attention should be paid to the incorporation basic knoweldge with technology of developmental biology and comparative biology in the research of wound repair before better understanding and new discoveries are achieved in this field.

To investigate the different expression of Fas, Fas L and Caspase 3 in hypertrophic scars and normal skins in order to explore their influences on scar formation, the expression intensity and distribution of Fas, Fas L and Caspase 3 were detected by immunohistochemistry and pathological methods in 8 cases of hypertrophic scars and 8 cases of normal skins. In normal skins, Fas and Fas L were mainly located in the cellular membranes and cytoplasms of epidermal cells and some fibroblasts. Caspase 3 was mostly distributed in epidermal basal cells and some fibroblasts. In hypertrophic scars, Fas and Fas L were principally existed in the membranes and cytoplasms of epidermal keratinocytes. The positive cellular ratio of two proteins was significantly reduced ( P