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>