Wound Age Determination of Bruises Using Immunohistological and Molecular Biological Assays.

动物实验研究了组织型纤溶酶原激活物（tPA）和纤维连接蛋白mRNA表达的有效性，以及炎症细胞动力学对瘀伤伤口年龄的估计。瘀伤是用2块直径为3mm的带孔铁板压迫小鼠背部皮肤造成的。小鼠分别在损伤后1、3、8、24、72、144和240小时被杀死。tPA mRNA表达在损伤后1小时达到峰值，在损伤后72小时略有升高。在损伤前后的表皮细胞、成纤维细胞和内皮细胞中，以及在中性粒细胞中3小时和巨噬细胞中72小时分别检测到。tPA被认为在组织重塑的第一步起着至关重要的作用。后期tPA mRNA表达的轻微升高可能与表皮增生有关。另一方面，纤维连接蛋白mRNA的表达呈双相性。损伤后1小时达到峰值，144小时显著增加。机械损伤的组织反应和凝血级联的激活可导致纤维连接的急性增加。成纤维细胞的增殖可能是后期峰值的主要原因。检查微观变化的相关性，如炎症细胞动力学和表皮增厚，与tPA、纤维连接蛋白和其他细胞因子的mRNA表达，将为瘀伤的急性和慢性期愈合和确定时间提供信息。

An animal experimental study was carried out to investigate availability of mRNA expressions of tissue-type plasminogen activator (tPA) and fibronectin, and inflammatory cell dynamics for wound age estimation of bruises. The bruises ware made by compressing the dorsal skin of mice with 2 iron plates with holes, 3mm in diameter. The mice were killed at 1, 3, 8, 24, 72, 144, or 240 hours post-injury. tPA mRNA expression peaked at 1 hour, and increased slightly at 72 hours post-injury. It was detected in epidermal cells, fibroblasts, and endothelial cells before and after injury, and from 3 hours in neutrophils and from 72 hours in macrophages, respectively. tPA was considered to play an essential role in the first step of tissue remodeling. A slight increase of tPA mRNA expression at later phase might be related to epidermal proliferation. On the other hand, expression of fibronectin mRNA was biphasic. It peaked at 1 hour, and significantly increase at 144 hours post-injury. Acute increase of fibronection would be due to tissue reaction of mechanical injury, and activation of coagulation cascade. Proriferation of the fibroblasts would be major cause of the late phase peak. Examination of the correlation of microscopic changes, such as inflammatory cell dynamics and epidermal thickening, with mRNA expression of tPA, fibronectin and other cytokines, would be informative for bruise healing and dating in the acute and chronic phases.