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 To observe the proliferation and migration of endothelial cells after 30% total burn surface area (TBSA) of deep partial thickness scald, and the effect of basic fibroblast growth factor (bFGF) on angiogenesis during wound healing.Methods A total of 133 male Wistar ratswere divided randomly into normal control (n=7), injured control group (n=42), bFGF group (n=42) andanti-c-fos group (n=42). The apoptosis expression of fibroblasts was determinedwith in situ hybridization and the changes of proliferation cell nuclear antigen(PCNA), focal adhesion rinase(FAK), c-fos and extracellular signalregulated kinase(ERK) proteins expression were detected with immunohistochemistry staining technique after 3 hours, 6 hours, 1 day, 3 days, 7 days, 14 days and 21 days of scald.Results In injured control group and bFGF group, theproliferation rate of the vascular endothelial had evident changes 7 days and14 days after scald； the expression of FAK was increased 14 days after scald. ERK proteins expression was different between injury control group and bFGF group at initial stage after scald. Stimulation of ERKs by bFGF led to up-regulation of c-fos and b expression of FAK. Conclusion Exogenous bFGF extended the influence on wound healing process by ERK signaling pathway, affecting migration cascade of vascular endothelial cell. The oncogene proteins play an important role on accelerating angiogenesis duringwound healing.
To investigate the best way of using fibroblast growth factor (FGF) in wound healing, the following experiments were performed. Twelve Wistar rats were chosen. Four 1.5 cm x 1.5 cm middle-thick skin wounds were made in the back of each rat, 2 in each side, and labelled as number 1 to 4. Number 1 wound of each rat was used as control, only PBS was applied to the wound, 50 microliters per time, twice a day from the first day to 11th day. Number 2 wound was sustained medication group, 50 microliters 4 micrograms/ml FGF was applied twice a day from the first day to 11th day; Number 3 wound was early medication group, 50 microliters 8 micrograms/ml FGF was applied twice a day from the first day to 5th day; Number 4 wound was late medication group, 50 microliters 8 micrograms/ml FGF was added twice a day from the 5th day to 11th day. By day 4, 8, 12 and 16, the area of wounds were measured, and the healing time of each wound was recorded. The elastic fiber, collagen fiber and DNA content were measured by immunohistological method. The result showed that the elastic fiber, collagen fiber and DNA content in the groups of FGF used were more than those in the control group. The healing time of the control group was 14.4 days while that of the early meduation group was 13.4 days, late medation group was 13.5 days and sustained medication group was 12.2 days. It was suggested that FGF could accelerate the wound healing, and sustained use of FGF was the best way of giving the drug.
To investigate the effect of Insulin and Danshen on anabolism and catabolism of collagen during the healing of wound, fibroblast which was cultured from human embryonic skin were divided into 3 groups: Insulin group, Danshen group and contral group. Each group was cultured for 2, 4 and 6 days, then the growth curve was established respectively. RESULTS: 1. The growth curve showed-insulin group gt; control group gt; Danshen group. 2. The rate of cell division in 3 groups was 19.6/1000, 2.5/1000, 3.77/1000 respectively. 3. The electron microscopic scanning showed that there was much of fibroid tissue surrounding the fibroblast cell in insulin group, but there was little fibroid tissue in Danshen group. The conclusion showed that insulin can accelerates proliferation of fibroblast and synthesis of collagen, but the effect of denshen was just on the contrary.
OBJECTIVE: To study the effect of therapeutic effect of heparin on wound healing of second-degree burned rats. METHODS: Deep second-degree burns with 20% of total body surface were made in 20 rats, which were randomly divided into 2 groups. The experimental group was treated subcutaneously injection with 1 ml of heparin 100 U/kg and saline solution, and the control group was treated with 1 ml of saline solution, once a day until complete healing of the burned wound. The healing time were compared, the growth of granulation tissue and collagen fibers were evaluated under light microscope, and the growth of fibroblasts were observed under electronic microscope. RESULTS: All rats survived, the healing time of experimental group (22.8 +/- 1.87 days) were much shorter than that of control group (26.2 +/- 2.82 days) (P lt; 0.005). Light microscope observation showed that the growth of granulation tissue and collagen fibers of experimental group were much better than that of control group, and electronic microscope also showed that the fibroblast growth was obviously better in the experimental group. CONCLUSION: Subcutaneous injection of heparin can promote wound healing.
Objective To study the effects of dermal template on the biological behaviors of fibroblasts during wound healing. Methods A total of 120 rats were made fullthickness wound modes on the dorsum and divided into 4 groups,in group 1, the wounds were allowed to heal by contraction（ConT）；in group2, the wounds covered with fullthickness skin grafts( FTSG); in group 3, the wounds were with split thickness skin grafts (STSG); and ingroup 4, the wounds were covered by dermal regeneration template with overlying thin splitthickness autograft (ADMT).The specimens were obtained at one week, two weeks, four weeks, six weeks,and twelve weeks respectively. The expressions of α smooth muscle actin(αSMA，characteristic of MFB）,fibronectin(FN),integrin α2,β1 and transforming growth factor β1(TGF-β1) were examined by immunohistochemical analysis. Results Positive expression of α-SMA、FN、integrin α2β1 and TGF-β1 in ADMT groups was significantly lower than that in STSG group and ConT group, but higher than that in FTSG group（P＜0.05）. Conclusion Dermal regeneration template can inhibit the transformation of FB to MFB and restrain the expressionof FN,integrin α2,β1,and TGF-β1 in fibroblasts which might reduce thepossibility of hypertrophyic scaring, and improve wound healing.
Objective To observe the expression and distribution of transforming growth factor-β1 (TGF-β1) in the healing process of bile duct and discuss its function and significance in the process of benign biliary stricture formation. Methods An injury to bile duct of dog was made and then repaired. The expression and distribution of TGF-β1 in the tissue at different time of the healing process were studied after operation with immunohistochemical SP staining. Results TGF-β1 staining was observed in the granulation tissue, fibroblasts and endothelial cells of blood vessels. High expression of TGF-β1 was observed in the healing process lasting for a long time. Conclusion The high expression of TGF-β1 is related closely with the fibroblast proliferating activity, extracellular matrix overdeposition and scar proliferation in the healing process of bile duct.
OBJECTIVE: To investigate the effect of heterogeneous (swine) acellular dermal matrix (s-ADM) and autologous overthin split-thickness skin (auto-OTS) composite grafting in repair of deep burns at articular sites. METHODS: From May 1999 to April 2000, 19 articular sites in 16 patients, including 14 males and 2 females, were treated. In all the 19 sites of deep burn, the total burn area varied from 2% to 48% and the full-thickness burn area varied from 1% to 35%. After the primary escharectomy (1 to 5 days later) and complete hemostasis, the s-ADM was utilized to cover the exposed articular sites and the auto-OTS was transferred on the surface of sutured s-ADM. The size of s-ADM applied to each patient varied from 25 cm2 to 150 cm2. Regular skin grafting was adopted elsewhere other than the articular site. The survival rate of all skin grafting was evaluated and pathological examination was performed. RESULTS: The survival rate of the composite skin was (90.80 +/- 18.34)%, which was obvious higher than the survival rate of contiguous granulosum skin grafting (P lt; 0.05) and almost the same with that of snip skin grafting(P gt; 0.05). The survived composite skin appeared as smooth and soft as normal skin, and the function of articular site almost recovered with neglectable hypertrophic scar. The pathological examination revealed that the normal cell grew into s-ADM with regularly arranged collagen fiber and neovascularization in the matrix. CONCLUSION: The combination of s-ADM and auto-OTS graft is cheap and effective method to cover wound and minimize hypertrophic scar.
It was reported in this article that a preparation of acid/heat-stable peptides (AHSP) from pig serum with a molecular-weight less than 18 ku a without antigenity and toxicity could exert enhancement effect on wound healing. Two pieces of polyvinyl alcohol (PVA) sponge implanted in rat dorsal subcutaneous pouchs of 20 mice were selected as the wound model. The subcutaneous pouch having one piece of sponge was taken as the experimental group and the other as the control. Injection of 50 microliters of such peptide preparation into the test sponge was performed once a day from the time of injury on for 5 consecutive times, while 50 microliters of BSA (5 mg/ml) into the control sponge in the same way. The levels of total DNA, protein and hydroproline in AHSP-treated sponge were observed significantly higher than those in the control sponge on the 7th and 10th days after wounding (P lt; 0.05). No significant difference was seen on the 14th postinjury day (P gt; 0.05). The effect of AHSP on proliferation of wound fibroblast cultured in vitro was also detected. In conclusion, such peptides derived from pig serum had the activity to accelerate wound healing without resultant excessive healing and its direct stimulation of the proliferation of wound fibroblast was probably one of the way which AHSP exerted its action.
Objective To explore the mechanism of full-thickness burn wound healing with autoskin grafting in fault hypodermis wound of granulation excision and to evaluate its effect.Methods By the techniques of clinical observation, histopathology, immunohistochemistry,TEM and FCM,we observed changes of the activity andstructure of grafted skin and the granulation tissue,collagnous fiber,microvessels,the ultramicrostructure of fibroblasts and the expression of basic fibroblast growth factor(bFGF) in the base of autoskin grafting in fault hypodermis wound in burned adult minipigs(Group A), and compared with traditional method of autoskingrafting on the basilar fibrous tissue wound of scraped partly granulation being(Group B) and control group (Group C, without treatment except de-fur).Results The grafted skin survived after 3 days of operation, and it had less injury and higher proliferative index(PI) in group A than in group B. The hyperplasiaof granulation tissue and vascular endothelial and the expression of bFGF were more evident in group A. After 5 days, the proliferation of endothelial cells and granulation and the protein synthesis of fibroblasts were more active in groupA, and at this moment, fresh collagen appeared and proliferated more actively in group B. After 7-14 days, epidermic structure and dermic microvascular density became normal gradually, the granulation on grafting base matured and transformed into fibrous connective tissue in group A. The same change deferred about 2 days in group B. After 21 days, the above pathologic change in group A was less than that in group B. After 3060 days of operation, Group A achieved much less contraction and transfiguration than Group B, and the grafted skin was tender and movable. Conclusion Autoskin grafting in fault hypodermis wound of granulation excision has a better effect than traditional operation.