Effect of hyperbaric oxygen on the scar formation at the rabbit ears at an early stage / 中华整形外科杂志

<p><b>OBJECTIVE</b>To observe the effect of hyperbaric oxygen on the scar formation at the rabbit ears at an early stage.</p><p><b>METHODS</b>16 New Zealand rabbits were used to establish the hypertrophic scar model on the ears, 4 wounds on each ear. The rabbits were randomly divided into hyperbaric group(n = 8) and control group (n = 8). The rabbits in the hyperbaric group received hyperbaric oxygen treatment, inhaling oxygen for 1 hour daily under 2ATA circumstance until the wounds were healed. The wound healing and the scar size, thickness, color and hardness in the ears were recorded. After healing, the scar was taken for histologic study with HE staining, Masson staining and trinitrophenol sirius red staining.</p><p><b>RESULTS</b>In hyperbaric oxygen group, the healing time of 64 wounds was (16.7 +/- 1.8) d, while it was (20.2 +/- 2.3) d in the control group, suggesting a significant difference between two groups (P < 0.05). The incidence of hyperplastic scar was lower (38/64, 59. 4% ) in hyperbaric oxygen group than that (52/ 64, 81.2%) in control group with significant difference between them (P < 0.05). Compared with the control group, the hyperbaric oxygen group had thicker corium layer and less fibroblasts, well-arranged but rare collagen and less collagen nodus and vortex-like structure under microscope. The hyperplastic index of scar was 3.48 +/- 0.94 in hyperbaric oxygen group and 4.65 +/- 0.76 in control group respectively (P < 0.01). The density of fibroblast in two groups were 186.5 +/- 27.3 (hyperbaric oxygen group) and 246 +/- 41.6 (control group) with statistically significant difference (P < 0.05). Furthermore, the area density of collagen fiber were (31.42 +/- 5.36)% in hyperbaric group and (43.62 +/- 7.36)% in control group (P < 0.05). The amount of collagen I and III was (71.42 +/- 5.36)% and (28.58 +/- 5.36)% in hyperbaric oxygen group, (62.46 +/- 7.32)% and (37.54 +/- 7.32)% in control group (P < 0.05). The ratio of collagen I to III was 2.499 in hyperbaric oxygen group, which was similar to the ratio (4:1) in normal skin, compared with the control group (1.664).</p><p><b>CONCLUSIONS</b>The hyperbaric oxygen can promote wound healing and effectively inhibit the early hyperplastic scar in rabbits ears.</p>

Effect of feeding cyclophosphamide on rabbit ears hypertrophic scar tissue in early stage / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of prevention and treatment of early scar through observing the effect of feeding immunosuppressive drug cyclophosphamide on rabbit ears hypertrophic scar tissue in early stage.</p><p><b>METHODS</b>Thirty-two Rabbit ears were used to establish animal models for hypertrophic scar and randomly divided into four groups: group of distilled water (A), group of cyclophosphamide 5 mg x kg(-1) x d(-1) (B), group of 10 mg x kg(-1) x d(-1) (C), group of 30 mg x kg(-1) x d(-1) (D). Before animal models were built and after administration for 14 days, 28 days, leukocytes and lymphocytes were detected. After 28 days, specimens were harvested and underwent HE staining and VG staining in order to assess HI, NA, AA value changes. The data (HI, NA, AA) from each group were compared by analysis of variance, and the variance for the rank sum test when missing.</p><p><b>RESULTS</b>On the 14th day, the number of leukocytes in group A, B, C, D were (8.62 +/- 0.58) x 10(9)/L, (4.48 +/- 0.41) x 10(9)/L, (2.7 +/- 0.26) x 10(9)/L, (1.33 +/- 0.27) x 10(9)/L; the number of lymphocytes in group A, B, C, D were (3.11 +/- 0.21) x 10(9)/L, (1.67 +/- 0.16) x 10(9)/L, (0.42 +/- 0.10) x 10(9)/L, (0.40 +/- 0.09) x 10(9)/L. On the 28th day, the number of leukocytes in group A, B, C, D was (8.63 +/- 0.53) x 10(9)/L, (5.10 +/- 0.27) x 10(9)/L, (3.10 +/- 0.26) x 10(9)/L, (1.98 +/- 0.20) x 10(9)/L; the number of lymphocytes A, B, C, D was (3.06 +/- 0.16) x 10(9)/L, (2.08 +/- 0.14) x 10(9)/L, (0.96 +/- 0.19) x 10(9)/L, (0.14 +/- 0.07) x 10(9)/L. On the 14th day and 28th day, the number of leukocytes and lymphocytes in experimental groups was reduced, showing a negative relation with cyclophosphamide dose (P < 0.05). The HI in group of A, B, C, D was 3.02 +/- 0.24, 2.59 +/- 0.43, 2.06 +/- 0.19, 1.63 +/- 0.11; the AA was 40.49 +/- 2. 07, 35.29 +/- 1.99, 28.36 +/- 1.87, 24.99 +/- 1.82; the NA was 4570.5 +/- 259.3, 4222.5 +/- 199.6, 3540.3 +/- 170.3, 3341.4 +/- 228.8. The difference in HI, AA, NA between control group and any of the experimental groups was statistically significant (P < 0.01). Each group, with the dose increased, except NA content of group C and D, the HI, AA, NA was more smaller, negative correlation, the difference was statistically significant (P < 0.05).</p><p><b>CONCLUSIONS</b>Feeding cyclophosphamide can inhibit leukocytes and lymphocytes number, so as to inhibit the proliferative activity of hypertrophic scar. It has significant effect on prevention of hypertrophic scar on rabbit ears in early stage.</p>

Influence of the VEGF antibody targeted vascular therapy on the expression of collagen type I in hyperplastic / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of the vascular endothelial growth factor( VEGF) antibody targeted vascular therapy on the expression of human collagen type I in hyperplastic scar of nude mice.</p><p><b>METHODS</b>The hyperplastic scar from one female burn patient with 1% TBSA deep-partial thickness burns were implanted into subcutaneous skin of scapular region of 48 nude mice. Three weeks later, the nude mice were divide into large dose (LA) , medium dose (MD) , small dose (SD) and control groups, with 12 mice in each group. The mice in LA,MD and SD groups were injected with 200 microl of 15,10, 5 microg/ml VEGF monoclonal antibody diluted in 0.01 mol/L PBS, respectively in the scar twice a week for 3 weeks, while those in C group were injected with equal amount of 0. 01 mol/L PBS. The area and volume of the scar in each group were calculated and histological changes were observed, and the expression of collagen type I mRNA and its protein in each group were determined 3 days after treatment.</p><p><b>RESULTS</b>The volume of scar in LA, MD, SD and C groups were (55.3 +/-4.1, 67.9 +/-5.7, 78.9 +/-5.5, 85.0 +7.3) mm(3), respectively. Compared with that in C group, the volume of the scar were significantly decreased in AD and MD groups ( P <0.05). A few number of vessels and fibroblasts were observed in LD, MD groups, with decreased number of collagen fibers arranged in order. Compared with that in C group ,The expression of procollagen type I mRNA and its protein in C group was obviously higher than those in LD and MD groups ( P < 0. 05) , but it was similar to those in SD group.</p><p><b>CONCLUSION</b>VEGF targeted vascular therapy is beneficial for the inhibition of the angiopoietins of hyperplastic scar, the expression of collagen , and the growth of scar.</p>