Effect of transfection of recombinant human endothelial nitric oxide synthase gene on hypertrophic scar fibroblasts in vitro / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of transfection of recombinant human endothelial nitric oxide synthase (eNOS) into human hypertrophic scar fibroblasts (HSFbs), and to observe NO secretion and the synthesis of collagen I and III.</p><p><b>METHODS</b>Recombinant human eNOS with karyocyte expressive vector was constructed in vitro, then was transfected into HSFbs which was isolated from hypertrophic scar tissues and cultured in vitro (T group). The HSFbs untransfected (normal culture) or transfected with empty-vector was used as control group and empty-vector group respectively. The mRNA expression of eNOS, collagen I and III was determined by Realtime PCR. The content of NO was determined by NO assay kit.</p><p><b>RESULTS</b>The expression of eNOS mRNA in T group was 5.92 +/- 0.21, which was obviously higher than that in empty-vector group (0.98 +/- 0.13, P < 0.05). The expression of collagen I mRNA (0.76 +/- 0.15), and collagen III (0.79 +/- 0.08) in T group was significantly lower than those in empty-vector group (0.98 +/- 0.15, 1.02 +/- 0.12, P < 0.05, respectively). The content of NO in T group (36.1 +/- 0.8 micromol/L) was obviously higher than that in empty-vector group (28.4 +/- 1.0 micromol/L, P < 0.01) and control group (27.7 +/- 1.3 micromol/L, P < 0.01).</p><p><b>CONCLUSION</b>HSFbs can be the target cells for eNOS gene transfection. The transfected cells can express eNOS and produce NO, which inhibit the synthesis of collagen.</p>

Effect of nerve growth factor on the promotion of sensory recovery of large skin graft in patients / 中华烧伤杂志

<p><b>OBJECTIVE</b>To analyze the influence of topical application of nerve growth factor (NGF) on nerve ending regeneration of large skin grafts in patients.</p><p><b>METHODS</b>Sixty wounds from 48 adult patients with small or moderate burn area and scar excision were randomly divided into NGF and control groups, with 30 wounds in each group. The wounds in control group were treated with simple saline solution, while those in NGF group, the graft was first wrapped in a piece of gauze holding 100 ml saline solution containing 9000 AU NGF before operation, and then flushed with same amount of NGF saline underneath skin after application of the graft. From 20 post-operative day on, NGF was injected at multiple points every other day for one month. In control group, only normal saline was used. The texture of the graft, pain sensation, temperature and two - point discrimination, BMRC grade were observed for 12 months. Skin specimens were obtained from 6 wounds in control group, 5 wounds in NGF group, and 4 specimens from normal skin for immunohistological examination of protein gene product 9.5 (PGP 9.5), synaptophysin (SYN), and neuron specific enolase (NSE). The nerve endings regeneration and distribution were also observed.</p><p><b>RESULTS</b>Compared with those in control group, each index of feeling recovered earlier and better in NGF group, with better two - point discrimination ratio and BMRC grade. One year after operation, 17 skin grafts in NGF group reached S4 grade, with two - point discrimination ratio of 1.11 +/- 0.14, while only 5 grafts in control group reached S4 grade, with two - point discrimination ratio of 1.56 +/- 0.73. Six months after operation, rich nerve endings, with integral adnexae were observed in microvascular bed of skin - graft region and tissue interspace around fibromas tissue in subcutaneous tissue in NGF group, while nerve endings were found to be scanty and slender in subcutaneous tissue in control group.</p><p><b>CONCLUSION</b>Local application of NGF can promote nerve regeneration and sensory recovery of grafted skin.</p>