Objective To observe the changes of MMP-1 and TIMP-1 expression in the pathological scar tissue after scar-skin replantation and to explore the mechanism of treating pathological scars with scar-skin replantation through a rabbit ear model.Methods Rabbit ears were used to establish the hypertrophic scar animal model in this study.Specimens were taken for three times:normal skin,hypertrophic scar and scar-skin replantion separately.We then performed HE staining,Masson staining and immunohistochemical staining to observe the expression of MMP-1 and TIMP-1 in these three groups of specimens.Results The expression of both MMP-1 and TIMP-1 significantly increased in the hypertrophic scar tissue after scar-skin replantation compared with the control group (P＜0.01).The expression of MMP-1 increased more significantly than that of TIMP-1 (P＜0.01).Conclusions The mechanism of scar-skin replantation's effect in the treatment for hypertrophic scar is relevant to the imbalance in the interaction between MMP-1 and TIMP-1 in the scar tissue.

Three hundred and nine patients with thyroid nodules detected by physical examination in Harrison International Peace Hospital from October 2013 to October 2017 were divided into intervention group (155 cases) and control group (154 cases). Patients in intervention group received oral levothyroxine sodium 25 g / d for 12 months and those in control group had no treatment, patients were followed up every 3 months to 12 months. After treatment, the maximum diameter and thyroid nodule volume of the intervention group were (31.87±3.84) mm and (17.32±0.94) cm3, which were significantly smaller than those of the control group [(34.01±3.72) mm and (24.25±1.21)cm3, P<0.05]. TSH in intervention group was lower than that in control group [(2.24±0.41) vs. (2.52±0.58) mIU/L, P<0.05] and free T4 (FT4) was higher than that in control group [(25.64 ± 3.85) vs. (16.39 ± 3.28) pmol/ L, P<0.05]. TC, TG and LDL?C in intervention group, were lower than those in the control group .The HDL?C level in intervention group was higher than that in control group (all P<0.05). After treatment, there were no malignant changes in the intervention group, while the malignant change rate in control group was 2.6％ (4/154). It is suggested that levothyroxine treatment can reduce TSH level in patients with benign thyroid nodules, inhibit the growth of thyroid nodules.