OBJECTIVE: To investigate the effect of nerve growth factor(NGF) on the burn wound healing and to study the mechanism of burn wound healing. METHODS: Six domestic pigs weighting around 20 kg were used as experimental animals. Twenty-four burn wound, each 2.5 cm in diameter, were induced on every pigs by scalding. Three different concentrations of NGF, 1 microgram/ml, 2.5 micrograms/ml, 5 micrograms/ml were topically applied after thermal injury, and saline solution used as control group. Biopsy specimens were taken at 3, 5 and 9 days following treatment and immunohistochemistry method was used to detect the epidermal growth factor(EGF), EGF receptor (EGF-R), NGF, NGF receptor (NGF-R), NGF, NGF-R, CD68 and CD3. RESULTS: The expression of EGF, EGF-R, NGF, NGF-R CD68 and CD3 were observed in the experimental group, especially at 5 and 9 days, no expression of those six items in the control group. CONCLUSION: NGF can not only act directly on burn wound, but also modulate other growth factors on the burn wound to accelerate the healing of burn wound.
OBJECTIVE This paper aims to explore the new method of continuous delivery of epidermal growth factor to wounds by transfected fibroblasts to promote wound repair. METHODS It was constructed a novel chimeric expression plasmid in which the biologically active portion of the human epidermal growth factor (EGF) gene was fused in-frame to the human granulocyte colony-stimulating factor signal sequence. RESULTS Clonally selected human fibroblasts transfected with this construct could secrete biologically active EGF. After the transplantation of irradiated gene-transfected fibroblasts suspended in fibrin glue to murine full-thickness wounds, EGF could be demonstrated for at least seven days in the wounds, slowly decreasing from initially 470 ng/L to 140 ng/L in 7 days. No EGF was found in the wound at 14 days. CONCLUSION A single application of irradiated EGF gene transfected fibroblasts to wounds can continuously deliver the transgene in vivo and can be used to administer drugs to the wound bed during the crucial first seven days of wound-healing.
Objective To investigate the effect of leptin on fibroblast proliferation and collagen synthesis as to elucidate that fibroblasts play a role in leptin’s effect on wound healing. Methods Purified dermal fibroblasts were derived from sucking wistar rat skin and exposedto leptin at concentration of 0, 10, 50, 100, 200, and 400 ng/ml. The survived fibroblasts were assessed by the colorimetric thiazolyl blue (MTT) assay. Replication of fibroblast was quantified by the incorporation of 3H-thymidine. Collagen synthesis of fibroblast cell was measured by the incorporation of 3H-proline into collagenasesensitive protein. Results The absorption of fibroblast exposed to leptin at concentration of 200 and 400 ng/ml 0.082±0.013, 0.091±0.018 was higher than that of control group 0.063±0.010, P＜0.05. The incorporations of 3H-thymidine of fibroblast exposed to leptin at concentration of 200 and 400 ng/ml 379±101 cpm,326±33 cpm were significantly higher than those of control group 219±56 cpm, P＜0.05. The incorporations of 3H-proline of fibroblast exposed to leptin at concentration of 200 and 400 ng/ml 911±55 cpm, 1 072±259 cpm were significantly higher than that of control group 679±176 cpm, P＜0.05. Conclusion Leptin can promote rat cutaneous fibroblast proliferation and collagen synthesis in vitro. This suggests that cutaneous fibroblast plays a role in leptin’s promoting skin wound healing and it may be one of the main mechanisms by which leptin enhances skin wound healing.
OBJECTIVE To explore the possible mechanisms of skin regeneration through the epidermal stem cells stimulated by epidermal growth factor (EGF). METHODS At 8 and 14 days after treatment with EGF, the tissue specimens from 8 skin ulcered patients who were treated with EGF were used to evaluate the distribution and differentiation of epidermal stem cells. The expression of beta 1 integrin, keratin 19 (K19), keratin 14(K14) and keratin 10 (K10) in skin was detected with SP immunohistochemical methods. Hematoxylin and eosin staining method were used to observe the tissue structure. Another 7 biopsies from ulcered patients without EGF management were used as the control. RESULTS The results from the hematoxylin and eosin staining showed that the epidermis in EGF treated wounds was thick and the epidermal ridges were enlarged both in 8 and 14 days compared with those in control skin. Immunohistochemical staining from beta 1 integrin and K 19 showed that all tissues treated with EGF were rich in epidermal stem cells both in 8 and 14 days. These stem cells were bigger in size and larger in number and localized at the base of the epidermis. In contrast, the positive expression cells of beta 1 integrin and K 19 in control group in the same time were scanty. It was found that there were some stem cell islands in epidermis treated with EGF in day 14 and absent from the control group. The expression of K14 and K10 could be observed in those terminally differentiating epidermal cells in both groups. CONCLUSION The results indicate that the possible mechanisms of skin regeneration stimulated by EGF comes from the mitogenic effects and differentiation of skin stem cells.
Objective To investigate the influence of lipopolysaccharide(LPS) on the proliferation and collagen synthesis of normal human skin fibroblasts so as to elucidate its relation with skin wound healing. Methods Fibroblasts wereisolated and cultured in vitro, and then exposed to different doses of LPS(0.005, 0.010, 0.050, 0.100, 0.500, and 1.000 μg/ml) from E.coli055∶B5 respectively. Then the absorbance (A) value of fibroblasts was determined with the colorirneteric thiazolylblue (MTT) assay, and the cell number was counted under inverted phase contrast microscope from the 1st day to the 9th day after LPS administration, and collagen synthesis of fibroblasts in culture medium was measured with the method of pepsin digestion after incorporation of 3Hproline into stable, single-layered, confluent fibroblasts at 7 days after LPS administration. Results Compared with control group, A value increased with the increasing concentration of LPS (0.005 μg/ml 0.500 μg/ml) and LPS of 0.100 μg/mlgroup had the best effect. The difference was remarkable from the 5th day to the 9th day(P＜0.05). A value decreased when challenged with the LPS of 1.000 μg/ml and the difference was remarkable from the 3rd day to the 9th day(P＜0.05). Cell number increased with theadministration of LPS of different concentrations (0.005 μg/ml 0.500 μg/ml) and LPS of 0.100 μg/mlgroup had the best effect. The difference was remarkable from the 1st day to the 6th day(P＜0.05). Cell number decreased remarkably when challenged with LPS of 1.000 μg/ml and the difference was remarkable from the 2nd day to the 9th day(P＜0.05). Collagen synthesis increased when challenged with LPS of different concentrations (0.005 μg/ml 0.500 μg/ml) and the 0.100 μg/ml group had the best effect. However, when the dose of LPS reached 1.000 μg/ml, it inhibited collagensynthesis. Conclusion LPS could promote the proliferation andcollagen synthesis of fibroblasts within a certain range of low doses, but over-high dose ofLPS might inhibit the proliferation and collagen synthesis of fibroblasts, suggesting that LPS of certain concentrations might contribute to wound healing, while excessive LPS has negative effect on wound healing.
OBJECTIVE: To investigate the efficiency of recombinant human epidermal growth factor (rhEGF) on burn wound healing and to explore the effective density of the ointments. METHODS: A total of 120 cases of burn in superficial II degree and profound II degree were randomly divided into 2 groups. In the first group of 15 cases of superficial II degree, the wounds were treated by rhEGF ointments of different density, 0.5 microgram/g, 10 micrograms/g and 50 micrograms/g, to screen out the effective density. And in the other 105 cases of the second group, optimal density of the ointments based on the result of the first group were employed to treat the burn wound in superficial II degree and profound II degree, with the self-corresponding wounds of the same degree as control, to study the efficiency of rhEGF on wound healing, according to the wound healing time, and adverse reaction of the ointment. RESULTS: In the first group, the average healing time of superficial II wound treated by ointments of 10 micrograms/g and 50 micrograms/g significantly shortened when compared with that treated by ointments of 0.5 microgram/g(P lt; 0.01), but there was no obvious difference between the cases treated by ointments of 10 micrograms/g and 50 micrograms/g. In the second group, the healing time of superficial II wound treated by ointments of 10 micrograms/g was (8.39 +/- 2.25) days, (9.52 +/- 2.56) days in the control (P lt; 0.01); and healing time of profound II burn treated by ointments of 10 micrograms/g was (16.80 +/- 2.99) days, (18.27 +/- 3.17) days in the control (P lt; 0.01). And healing rates of burn wound at different periods were higher than those of the control. CONCLUSION: The above results indicate that rhEGF ointments can enhance burn wound healing significantly, and the ointment of 10 micrograms/g is a good choice for clinical application.
OBJECTIVE: To summarize the application of simple skin traction technique in repair of soft tissue defect of limb. METHODS: From 1999, 42 cases of soft tissue defect of limbs were repaired by simple skin traction technique instantly; the defect area ranged from 2.5 cm x 2.0 cm to 8.0 cm x 6.5 cm. RESULTS: The soft tissue defect less than 8.0 cm can be sutured instantly. All of the wound achieved primary healing without infection and necrosis of skin edge, the circulation and sensation of limbs were normal; healing time was 10 days to 16 days, 12.8 days on average. Thirty-two cases were followed up for 6 months; the shape and function recovered well. CONCLUSION: Simple skin traction technique is a good option to repair the soft tissue defect of limbs.
目的 观察AQUACEL-Ag®亲水性纤维敷料对肛周脓肿患者术后创面愈合的作用。方法 将49例肛周脓肿术后患者按随机数字表法随机分为试验组（25例）和对照组（24例），分别予AQUACEL-Ag®亲水性纤维敷料换药（1 次/3d）和无菌凡士林纱布换药（1次/d），并观察2组患者的换药时创面疼痛程度、创面愈合时间、创面换药次数、创面愈合率及换药时创面分泌物培养结果。结果 试验组在创面疼痛、愈合时间、创面换药次数及换药时分泌物培养转阴时间方面均优于对照组（P＜0.05）；动态监测创面愈合率：第3d时2组间比较差异无统计学意义（P＞0.05），第9、15、21d时试验组创面愈合率明显高于对照组（P＜0.05）。结论 从本组有限的数据看，AQUACEL-Ag®亲水性纤维敷料对肛周脓肿患者术后创面愈合有重要作用。