【作者】 徐敏；

【导师】 张明谏；

【作者基本信息】 天津医科大学 ， 外科学， 2010， 硕士

【摘要】 目的：对比观察Wistar大鼠深Ⅱ°烫伤创面应用咪喹莫特对创面愈合时间及胶原沉积的病理学的影响,探讨咪喹莫特在Wistar大鼠深Ⅱ°烫伤创面愈合及瘢痕形成中的作用,为深入研究烧伤创面早期应用咪喹莫特预防和治疗瘢痕增生提供依据。方法：制备Wistar大鼠深Ⅱ°烧伤创面模型,50只Wistar大鼠,采用同体对照方法,每只大鼠背部左右各四个创面,右侧创面为实验组,左侧创面为对照组。实验组创面给予5%咪喹莫特药棉包扎,对照组创面给予凡士林油纱包扎。伤后当天晚8时治疗开始施加。于伤后第3天、5天、8天、10天、12天、15天、17天、19天、22天、24天、26天晚8时重复换药治疗。分别于伤后第4天、7天、14天、21天、28天,随机各处死10只大鼠,取创面组织进行HE染色观察创面炎症反应及创面深度变化、苦味酸天狼星红染色在偏振光显微镜下观察Ⅰ型、Ⅲ型胶原沉积变化、羟脯氨酸检测观察创面胶原蛋白总量的变化,同时观察创面愈合时间及创面愈合后瘢痕挛缩情况,实验数据应用SPSS 11.5统计学软件,组间差异采用配对T检验分析,P<0.05为差异有统计学意义。结果：1.创面平均愈合时间及创面瘢痕平均收缩率：实验组创面平均愈合时间为25.2±1.7d,对照组创面平均愈合时间为24.4±1.3d,均数差别无显著性,P>0.05；创面瘢痕平均收缩率：伤后第28天,实验组创面瘢痕平均收缩率为(46.7±4.82)%,对照组创面瘢痕平均收缩率为(70.4±5.35)%,均数差别有显著性,P<0.05,表明咪喹莫特能减轻瘢痕收缩；2.组织HE染色：伤后第4天实验组与对照组可见大量组织变性坏死,胞浆浓缩,核固缩,不连续的表皮细胞层覆盖创面被两侧背部新生的表皮间断,创面表层发现水泡和纤维蛋白白细胞焦痂并有薄薄一层呈肉芽组织(急性炎症细胞渗液和大量的中性粒细胞和巨噬细胞),真皮层可见大量炎性细胞浸润,呈现无血管,并且部分皮脂腺单位破坏；伤后第7天、14天、21天,两组创面创面均为急慢性炎症反应,实验组成纤维细胞数、纤维细胞数、毛细血管数、新生表皮层数比对照组少,差别有显著性,P<0.05；伤后第28天,治疗组与对照组创面上皮完全地、平均地修复,对照组纤维化较实验组重。3.苦味酸-天狼星红染色显示：实验组创面Ⅰ型胶原含量呈降低趋势；而对照组创面Ⅰ型胶原含量明显呈增长趋势。实验组与对照组各时间创面Ⅰ型胶原含量比较,伤后第4天,实验组创面Ⅰ型胶原含量低于对照组,P>0.05,差别无显著性；伤后第7天、伤后第14天、伤后第21天、伤后第28天,实验组创面工型胶原含量均低于对照组,P值分别为P<0.05,P<0.01、P<0.01、P<0.01,差别有统计学意义。实验组与对照组Ⅲ型胶原含量各时间点均数无差别无显著性,P>0.05。实验组Ⅰ/Ⅲ型胶原自伤后第4天起逐渐降低；对照组该比值自伤后第4天到伤后第7天为增加,随后比值逐渐降低。4.创面羟脯氨酸含量检测显示：实验组与对照组创面羟脯氨酸(HOP)含量在创面愈合过程中随时间逐渐增加,至伤后21d开始降低。实验组创面HOP平均含量比对照组创面HOP平均含量增长幅度小,同一时间实验组创面HOP含量低于对照组,两组间差异有显著性,P<0.05,有统计学意义。结论：1.咪喹莫特治疗Wistar大鼠深Ⅱ°烫伤创面,实验组创面平均愈合时间与对照组比较,差别无显著性；咪喹莫特对创面愈合早期的瘢痕挛缩有明显改善；2.创面H-E染色显示伤后两组炎症反应无明显差异,伤后各时间点实验组创面成纤维细胞数、纤维细胞数、毛细血管数、新生表皮层数比对照组少,说明咪喹莫特对成纤维细胞有抑制作用,有助于减轻瘢痕增生；3.苦味酸天狼星红染色观察结果显示应用咪喹莫特能有效抑制Ⅰ型胶原纤维的形成,降低Ⅰ/Ⅲ型胶原比值,从而增加愈合后瘢痕的弹性,可改善创面愈合后质地；4.羟脯氨酸检测结果显示咪喹莫特能有效降低胶原的沉积。更多还原

【Abstract】 ObjectiveBy comparing the representation of deep partial thickness burn wound after using imiquimod, observe the changes in wound healing time and collagen deposition. On this basis, discuss whether imiquimod can play an effective role in prevention of scar conformation and contracture.MethodsPreparation of experimental model, fifty adult Wistar rats, male, were used in this study. Control method using the same body, each rat had eight 10mm×10mm squares; four were evenly outlined on each side and along the longest axis of the vertebral column using a prepared template positioned between the anterior and posterior limbs.Wounds of the right side were the experimental group, wounds of the left side were the control group.The wounds of experimental group were randomly allocated for treatment with cotton gauze soaked in 5% IMQ cream overnight. The wounds of control group were treated with Vaseline pledget. Treatment started the day after burn infliction and repeated on PBD 3、PBD 5、PBD 8、PBD 10 PBD12、PBD 15、PBD 17、PBD 19、PBD 22、PBD 24、PBD 26. On five occasions (PBD 4,7,14,21and 28), ten animals were anesthetized and executed separately. Tissue was then collected from the dorsum with a surgical blade. Observed whether the wounds showed infection. H-E stained sections were examined by light microscopy, to observe the inflammation and healing of the wounds; Under polarized-light microscope and photographed, Picric acid-Sirius red stained were examined type-Ⅰand type-Ⅲcollagen content; By chemical assay, examined the change of HOP content; Using SPSS 11.5 statistical software, Data was examined with Paired-Sample T test, and P<0.05 for the difference was statistically significant.Results1.Wound healing time and rate of scar shrinkageThe time of IMQ group was 25.2±1.7d,while the time of Vaseline pledget group was 24.4±1.3.P>0.05,there was no significant;Rate of scar shrinkage:The rate of IMQ group was(46.7±4.82)%, while the rate of control group was (70.4±5.35)%.P<0.05,there was a significant difference. So, IMQ could lighten scar contraction;2.H-E stainedOn PBD 4, there was no significant between experimental group and control group;on PBD 7,14 and 21,the inflammation of experimental was stronger than control group, but fibroblasts and collagen fibers were less than control group, P<0.05,there was a significant difference; on PBD 28,the wounds of both groups recovered with epithelial cells and were complete and evenly, but fibrosis of control group was more serious than experimental group;3.Picric acid-Sirius red stained and analysis of type-Ⅰ/type-Ⅲcollagen contentType-Ⅰcollagen deposition had increased in control group and decreased in experimental group. Type-Ⅲcollagen deposition was not found significant difference in both groups.The type-Ⅰ/type-Ⅲcollagen ratio was different between two groups.Before PBD 7,the rate in control group was increased. Subsequently, it was decreased; while, in experimental group, the rate was decreased since PBD 4;4.Hydroxproline(HOP) detectionDuring the process of the wound healing, HOP was increased in both two groups. Since PBD 21,it began to decrease. But in control group, the growth was larger than experimental group.And in same point it had a significant difference, P<0.05.ConclusionDuring the healing process, IMQ has no effect on wound healing time, but it can significantly improve scar shrinkage. Fibroblasts and collagen fibers in IMQ treatment group were less than control group. Type-Ⅰcollagen deposition in IMQ treatment group was decreased and total collagen was less than control group.So, IMQ could inhibit the growth of fibroblasts, lighten scar contraction, decrease collagen deposition, especially type-Ⅰcollagen.更多还原