Objective To investigate the influence of enamel matrix proteins (EMPs) on the attachment, prol iferation and pre-mRNA of type I collagen synthesis of cultured human dermal fibroblast cells. Methods Human dermal fibroblast cells were obtained from human acrobystia and cultured in DMEM medium with 10% FBS. The 3rd to 6th passage cells were used. Ninety-six-well plates and 6-well plates were pre-coated with different concentrations of EMPs (50, 100, 150 and200 μg/ mL). ① The cell attachment experiment: 0.2 mL cells suspension at the concentration of 1 × 106/mL was added to the pre-coated 96-well plates as the experimental groups (groups A, B, C and D based on different concentrations of EMPs). At 1.5, 3.0, and 4.5 hours after inoculation, the attached cells were measured by MTT method. ② The cell prol iferation experiment: 0.2 mL cells suspension at the concentration of 5 × 104/mL was added to the pre-coated 96-well plates as the experimental groups (groups A1, B1, C1 and D1 based on the different concentrations of EMPs). At 2, 4, 6 and 8 days after inoculation, the cells were measured by MTT method. ③ The synthesis experiment of pre-mRNA: 2 mL cells at the concentration of 1 × 106/mL was added to the pre-coated 6-well plates as the experimental groups (groups A2, B2, C2 and D2 based on different concentrations of EMPs). At 5 days after inoculation, the synthesis of pre-mRNA was measured by RT-PCR method. Human dermal fibroblast cells were added to the un-coated plates as the control groups. Results ① The cell attachment experiment: There were significant differences in attachment cells between the control group, group A and the groups B, C and D (P lt; 0.05). There were no significant difference between group A and control group (P lt; 0.05). ② The cell prol iferation experiment: At 2 days, there were no significant differences in absorbance between the control group and the experimental groups (P gt; 0.05); at 4 days and 6 days, the absorbance of groups B1 (0.598 ± 0.020 and 0.639 ± 0.016 ), C1 (0.582 ± 0.017 and 0.641 ± 0.020) and D1 (0.574 ± 0.021and 0.635 ± 0.021) was significantly higher than that of the control group (0.548 ± 0.021 and 0.605 ± 0.019, P lt; 0.05); at 8 days, the absorbance of group B1 (0.629 ± 0.012) and group C1 (0.631 ± 0.014) was significantly higher than that of the control group (0.606 ± 0.031, P lt; 0.05). ③ The synthesis experiment of pre-mRNA: The synthesis of type I collage pre-mRNA of groups B2, C2 and D2 was significantly higher than that of the control group. Conclusion EMPs stimulate human dermal fibroblast cell attachment, prol iferation and synthesis of type I collage pre-mRNA, and its maximal effect can be achieved at the concentration of 100 μg /mL.
Objective To study the effect of dexamethasone to protect flaps from an ischemia-reperfusion injury and elucidate its mechanism of regulating the death course of the neutrophils.Methods The rats were randomly divided into 3 groups.The vein of the rat was clamped for 8 h after the flap had formed. Group A: the normal flap; Group B: the saline control flap; Group C: the treatment flap with dexamethasone. The survival area of the flaps was measured at 7 days; the apoptotic and necrotic neutrophils,tumor necrosis factor α （TNF-α）, and interleukin 10 （IL-10） concentrations were measured. Results The flap survival areas in Groups A and C were larger than those in Group B. The apoptotic neutrophils in Group B were fewer than those in Groups A and C on the 1st and 3rd days after operation; however, they were more in number in Group B than in groups A andC on the 6th day. The necrotic cells in Group B were more in number than those in Groups A and C. In Group B, the plasma TNF-α concentration reached the maximum level at 1 h,while the IL-10 level reached the lowest 3 h after the reperfusion. In Group C, the TNF-α concentration was lower than that in Group B and decreased dramatically at 6 h. The IL-10 concentration was the lowest at 1 h, and increased rapidly at 3 h. Thus, ischemia reperfusion could injure the flaps, probably through the abnormal action of the neutrophils, such as the disordered secretion of the cytokines and abnormal death course of the neutrophils. Conclusion Dexamethasone can protect the flap from an ischemia-reperfusion injury by its regulation for the neutrophil function.
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 effect of subcutaneous tissue trimming on the survival skin area of avulsion skin flap. METHODS: Degloving injury was created in bilateral hind limbs of 7 pigs with avulsion injury machine, 4 cm x 10 cm avulsion skin flaps were elevated in degloving areas. Skin flaps in one side were replanted as control without any treatment. Subcutaneous tissue in the skin flaps of another side was partially excised and replanted by trimmed skin flaps. Survival skin flaps was calculated with computer at 7 days after operation. RESULTS: In the control group, the survival skin area was (40.41 +/- 9.23)%, while in the experimental group, the survival skin area was (60.90 +/- 15.26)%. There was significant difference between the two groups (P lt; 0.05). CONCLUSION: Trimming off subcutaneous tissue does improve the survival area of avulsion skin flap.
【Abstract】 Objective To investigate the angiogenesis in hypertropic scar tissue of rabbit ears at different periods and to explore a new method to prevent hyperplastic scar. Methods Nineteen Japanese white rabbits(weigthing 2.0-2.5 kg) were made animal models of hypertropic scar of ear. At 10th, 30th, 60th and 90 days, after epithel ization, the microvessel and microcirculation in hyperplastic scar of 8 rabbits were studied by microcirculation microscope and laser Doppler flowmetry. The other 11 rabbits’ right or left ears were randomly chosen into experimental group and control group. At 10 days after epithel ization,40 μL of adenovirus extracellular protein with metalloprotease and thrombospondin 1 domains (Ad-METH1) was injected into tissue of scar along the perimeter of the scar in experimental group. The same volume of empty adenovirus was injected in control group. After 30 days of injection, the gross appearance of 10 rabbits’ ears scar was recorded, the number of microvessel in scarwas counted and HE stainning of scar tissue was performed in experimental and control groups. One additional rabbit was used to evaluate the mRNA and protein expression of METH1 by RT-PCR and Western blot after 3 days of injection. R e sults The average number of microvessel at 10, 30, 60 and 90 days after epithel ization was 42.37 ± 3.89, 49.46 ± 4.13, 33.12± 4.34 and 13.24 ±2.31, respectively; the average value of microcirculatory perfusion at 10, 30, 60 and 90 days after epithetl ization was (37.75 ±2.11), (59.87 ± 6.46), (44.53 ± 6.14) and (29.21 ± 1.84)PU; the density of microvessels and perfusion of microcirculation in scar tissues during prol iferative stage (from 10 to 60 days after epithel ization) were markedly higher than that during mature period (90 days after epithel ization, P lt; 0.05).At 10 to 30 days after epithel ization, the histol igical features of scar showed early stage of prol iferation and prol iferative stage appearance; at 60 days after epithel ization, it is still in prol iferative stage, while some of scars were in mature phase; at 90 days after epithel ization, the histol igical features of scar were mature period appearance. At 3 days after Ad-METH1 injection, METH1 gene was successfully expressed at both mRNA and protein levels in experimental group, but not in control group. At 30 days after injection, the gross appearanceobservation showed that scars in experimental group were flat and soft with the color close to normal, but scars incontrol group were obvious and hard. The number of microvessel of scar tissue was 12.38±2.56 in experimental group and 48.12±6.46 in control group, showing statistically significant difference between two groups(P lt; 0.01). In experimental group, HE staining shows that the density of microvessel and the number of fibroblasts were greatly decreased and collagen fibers arranged regularly. In control group, plenty of fibroblasts and abundant microvessels were observed. Thick and tight collagen fibers were seen in the outer layer of dermis with a irregular arrangement. Conclusion Theanti-angiogenesis by Ad-METH1 may have a promising appl ication in the prevention of human hyperthropic scar.
Objective To investigate the clinical value of computed tomographic angiography (CTA) and three-dimensional reconstruction technique in repairing scalp avulsion wound with large skull exposure by the free latissimus dorsi flap transplantation. Methods Between October 2007 and June 2012, 9 female patients with serious scalp avulsion and large skull exposure were treated, aged 23-54 years (mean, 38 years). The injury causes included machine twist injury in 6 cases, traffic accident injury in 2 cases, and falling from height injury in 1 case. Before admission, 3 patients had scalp necrosis after scalp in situ replantation, and 6 patients underwent debridement and dressing. The time from injury to admission was 8 hours to 7 days (mean, 1 day). The avulsed scalp area ranged from 75% to 90% of the scalp area (mean, 81%); the exposed skull area ranged from 55% to 70% of the scalp area (mean, 63%). Two patients had unilateral auricle avulse. CTA was used to observe the superficial temporal artery and vein, facial artery, external jugular vein, dorsal thoracic artery and vein, and measure the blood vessel diameter before operation. According to the CTA results, the latissimus dorsal skin flaps were desinged to repair wounds in 7 cases, the latissimus dorsal muscle flaps combined with skin graft were used to repair wounds in 2 cases. According to preoperative design, operation was successfully completed in 7 cases; great saphenous vein was used as vascular graft in 2 cases having poor images of superficial temporal vessels. The size of latissimus dorsal skin flaps ranged from 20 cm × 14 cm to 25 cm × 20 cm; the donor site was repaired with skin graft. The size of latissimus dorsal muscle flaps were 23 cm × 16 cm and 16 cm × 10 cm; the donor site was directly sutured. Results The blood vessel diameter measured during operation was close to the value measured before operation. The operation time was 6-8 hours (mean, 6.5 hours). The latissimus dorsal muscle (skin) flap and skin graft survived, with primary healing of wound or incision at donor site. The patients were followed up 3 months-2 years (mean, 6 months). The flap had soft texture and skin had no ulceration. Conclusion The free latissimus dorsi flaps can repair scalp avulsion with large skull exposure. Preoperative CTA can get the vessel anatomical structure and diameter at donor and recipient sites, which will guide the operation program design and implementation so as to shorten the operation time and improve the accuracy rate of vascular anastomosis.