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 explore the healing mechanism of full-thickness wound treating by the intermingled skin transplantation of large sheet allograft with autograft through studying the expression of laminin (LN). METHODS Thirty-six SD rats with 10% to 15% of total body surface area (TBSA) full-thickness were made. After 3 days, the devitalized tissue were excised and transplanted a large sheet of allograft from Wistar rats and islets of autografts were implanted 3 days later. On day 3, 5, 7, 14, 21 after allografting, the expression of LN in the grafts were detected by immunohistochemistry. RESULTS On the 7th day postallografting, LN, which played positive action of epidermal cell adhesion, still retained in the allodermis after the rejection of alloepidermis occurred. On the 14th day postallografting, there appeared scattered LN underneath the epidermal cells migrating from islets of autografts. On the 21st day postallografting, LN in the basement membrane of skin grafts had completely formed. CONCLUSION The intermingled transplantation of large sheet allograft with autograft may provide components of basement membrane for wound healing, which may help to improve the appearance and function of skin.
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.
OBJECTIVE: To investigate the availability and effect of skin stretch in closing the firearm injured soft tissue defect. METHODS: Eight white pigs with firearm injured soft tissue defect were divided into 3 groups. Each group I and group II had 3 pigs which were performed skin stretch. The control group had 2 pigs without stretch. The average diameter of the defect in three groups was (7.3 +/- 0.2) cm, (9.1 +/- 0.3) cm, (7.3 +/- 0.2) cm respectively, and the site of defect was on the lateral thigh and buttock. RESULTS: Skin stretch could make a visible reduction of the wound. It was possible to close the wound by direct traction when the diameter of the buttock wound was less than 7 cm, and when the diameter of the lateral thigh wound was less than the radius of thigh. The skin stretch should not last more than 7 days and the best effect appeared in 4 to 5 days after performing the skin stretch. CONCLUSION: The skin stretch can be applied in the repair of the firearm injured soft tissue defect. It has many advantage compared with the tradtional treatment.
Objective To investigate the results of human amniotic membrane(HAM) which are loaded with marrow mesenchymal stem cells(MSCs) and epidermis cells in treating fullthickness skin defect combined with radiation injury. Methods Eight minipigs were used in this study. Three round fullthickness wounds（Ф3.67cm）, which combined with radiation injury, were created on the dorsum of each side close to the vertebral column in each animal. Among 48 wounds, 24 left side wounds were treated with HAM loaded with MSCs and epidermis cells as experimental group (group A), 16 right side wounds with simple HAM (HAM group, group B) and 8 right side wounds with oil gauze as control (group C). The granulation tissue, reepithelization and wound area were observed after 1,2 and 3 weeks. Immunohistochemistry was performed using vWF as a marker for blood vessels.Image analysis was employed to test new area of wound at different interval time and healing rate of wound.Results The healing time of group A was 6 to 7 days faster than that of group C and 5 to 6 days faster than that of group B. After 15-17 days of graft, there were significant differences in new area of wound and healing rate between group A and groups B,C(Plt;001). New epidermis fully covered whole wound surface in group A, and their granulation tissue, which contained a lot of vWF, fibroblasts, capillaries and collagen, grew well. Many inflammatory cells still were seen in groups B and C, and their contents of vWF, fibroblasts, capillaries and collagen in granulation tissue were smaller than that in group A.Conclusion The graft of HAM loaded with MSCs and epidermis cells played an effective role in promoting healing of wound combined radiation injury with high quality.
In order to investigate the function of epidermal growth factor (EGF), the following experiments were performed. Thirty white rats were chosen and divided into 3 groups. In the back of each rat, two 2 cm x 2 cm wounds were made bilaterally, the skin and subcutaneous tissue was removed. EGF were used in one of the two wounds randomly, while those without EGF usage in control. After 1, 2 and 3 weeks, the rats were sacrificed. The area of the wounds was measured, and the healing time of each wound was recorded. The results showed that the healing time of EGF group was 14.6 days while that of control group was 18.5 days (P lt; 0.01). Furthermore, the DNA, protein and hydroxyproline contents of EGF group were higher than those of the control group (P lt; 0.01). It was suggested the EGF could accelerate wound healing and shorten the healing time.
Objective To compare the reparative effects between the acellular small intestinal submucosa andthe acellular amnion as dressings for traumatic skin defects. Methods Three full-thickness skin defects, which wereclose to the vertebral column of the pig, were created on both sides of the dorsum. The skin defects were randomlydivided into three groups. In each group, the following different materials were used to cover the skin defects: theacellular amnion in Group A, the acellular small intestinal submucosa (SIS) in Group B, and the physiological saline aguze in Group C (the control group). The specimens from the skin defects were harvested for a histological evaluation and for determination of the hydroxyproline content at 10 (2 pigs), 20 (2 pigs), and 30 days (3 pigs). We observed the healing process of the wound and its healing rate, counted the inflammatory cells, vasecular endothelial cells, and proliferating cells, and determined the hydroxyproline content. Results The acellular amnion in Group A and acellular SIS in Group B adhered to the wound tightly, but they did not adhere to the dressing; when the dressing was changed, the wound did not bleed. The saline gauze in Group C adhred to the wound tightly, but when the dressing was changed, the wound bled until 22 days after operation. Under the microscope, the collagen in the tissue below the epithelium was arranged more regularly and there were fewer cells concerned with inflammation in Groups A and B than in Group C at 10, 20, and 30 days after operation. At 10, 20, and 30 days after operation, the wound healing rate was greater in Groups A and B than in Group C, The number of the inflammatory cells and the proliferating cells were greater in Groupo C than in Groups A and B. There was a statistically significant difference (P lt; 0.05),At 20 and 30 days after operatin, the content of hydroxyproline was greater in Group c than in Group A and B. There was a statistically significant difference (P lt; 0.05). However, there was no statistically significant difference between Group A and Group B in the wound healing rate, the numbers of the inflammatory cells, vascular endothelial cells and prokiferating cells, and the content of hydroxyproline(P gt; 0.050). There was no statistically significant difference among the three groups in the number of the vascular endothelial cells. Conclusion Compared with Group C........
Objective To construct a bioengineered dermis containing microencapsulated nerve growth factor (NGF) expressing -NIH3T3 cells and to study the effect of the microencapsule on the bioengineered dermis and acute wound healing. Methods A recombinant NGF (PcDNA3.1+/NGF) was constructed and transfected intoNIH-3T3 cells using FuFENETM6 transfection reagent. Positive cell strain was cultured and enclosed in alginate-polylysine-alginate(APA) microcapsules in vitro. Bioengineered dermis was incorporated with NGF-expressing micorencapsules and human fibroblast cells as seed cells using tissue engineering method. The characteristics of the dermis were described by the content of Hydroxyproline(Hyp), HE staining. The content of NGF in the dermis culturing supernatant was measured by ELISA method. These bioengineered dermis were transplanted onto the acute circular full thickness excisional wounds on the dorsum of each swine to observe the rate of reepithelization and wound healing: NGFNIH3T3 microencapsulations(group A), NIH3T3 microencapsulations( group B), empty microencapsulations (group C), NGF incorporated with collagenⅠ( group D) and blank (group E as control group). Results NGF can be tested stably about 124.32 pg/ml in the dermis culturing supernatant after 6 weeks, and the content of Hyp in group A was 69.68±6.20(mg/g wet weight) and increased about 2 times when compared with control groups after 1 week. The tissue engineering skin grafts which can secrete NGF were used to ure the acute wounds and the rate of reepithelization was promoted. The periods of wound healing were 25±2 days in group A, 34±3 days in group B, 34±2 days in group C, 33±2 days in group D and 40±3 days in group E.The period of wound healing was decreased about 10 days at least. Conclusion NGF-expressing NIH3T3 microencapsulates can promote the quality of bioengineered dermis and alsopromote acute wound healing.
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.
Objective To observe the epidermal width, the amount variation and distribution character of epidermal stem cells(ESCs) and the wound healing rate at different periods of diabetes mellitus(DM) rats after trauma, thento study the correlation of them. Methods Forty-eight Wistarrats were divided into DM group and normal control group randomly(n=24).TheDM rats were induced by streptozocin (STZ) and then made chronic healing wound by special perforex.At the 3rd, 4th, 7th,14th and 21st days after trauma, the healing rate was calculated, the wound edge and granulation tissue were obtained for haematoxylin-eosin (HE) staining and immunohistochemical staining of keratin 19(K19) and β1 integrin. Then the epidermal width, the area and the gradation value of positive unit(PU) were measured. Results At the 3rd, 7th,14th and 21st days after trauma, the wound healing rates of normal rats were 24.48%±3.37%, 50.46%±1.26%, 92.82%±2.12% and 99.41%±0.66% respectively, while those of DM rats were 2.43%±1.02%, 40.59%±1.65%, 80.77%±3.57% and 85.40%±0.94% respectively, showing significant differences (Plt;0.01). Before trauma, there was no significant difference in the epidermal width between normal rats and DM rats (Pgt;0.05). However, at the 3rd, 7th, 14th and 21st days after trauma, the epidermal widths of normal rats were 26.43±3.21, 33.29±3.52, 31.53±3.35 and 26.01±3.19 μm respectively, while those of DM rats were23.58±2.33, 31.02±3.38, 33.72±5.49 and 21.80±4.02 μm respectively,the epidermal widths in DM rats were significantly lower than those in normal rats(Plt;0.01). The average PU value of K19 in normal rats were 91.68%, 93.14%, 72.27% and 70.31% respectively, while those in DM rats were 40.29%, 40.79%, 29.94% and 10.37% respectively. The average PU value of β1 integrin in normal rats were 49.6%, 91.16%, 77.13% and 57.17% respectively, while those inDM rats were 38.94%, 24.16%, 61.36% and 38.83%. The results indicated that the average PU values of K19 and β1 integrin in DM rats were significantly lower than those in normal rats(Plt;0.05). Conclusion The amountand activity decrease of ESCs may be one of the important mechanisms of difficult recovering wounds of DM rats.