Objective To study the mechanism of anti-aging effect of dimethylaminoethanol (DMAE) and compound amino acid (AA) injection by mesotheray in D-galactose-induced skin aging rat.Methods Eighty rats were randomly divided into aging treatment group (60 cases),aging control group (10 cases) and normal control group (10 cases).The skin aging models were established by subcutaneous infectim of D-galactose.From the 18th day,the aging treatment group were injected intradermally in the rats' both sides hip skin with 0.2％ DMAE+ AA,0.1％ DMAE+AA,0.2％DMAE,0.1％ DMAE,AA,and saline,once a week.After four weeks,HE,water content,superoxide dismutase (SOD) activity,hydroxyproline (HYP) and malondialdehyde (MDA) content were measured.Results Compared with the aging control group,the epidermal and the dermal thickness and the collagen area of rats skin' increased significantly in 0.2 ％ DMAE+ AA and 0.1％ DMAE+ AA treatment groups (P＜0.05).0.2％ DMAE+AA and 0.1 ％ DMAE+AA treatment groups also had higher SOD activity,HYP content and lower MDA content than other groups (P＜0.05),but no difference was noted among normal control group,0.2％ DMAE+AA and 0.1％ DMAE+AA group (P＞0.05).There were no differences in water content among groups (P＞0.05).Conclusions Intradermal injection with 0.1％ DMAE+ AA and 0.2 ％ DMAE+AA in aging rats may increase the epidermal and the dermal thickness and the collagen of rats skin' improve SOD activity,HYP content and decreased MDA content,indicating that it has ability to clear skin free radicals,enhance antioxidant capacity and skin collagen metabolism,and thus prevent skin aging.

ObjectiveTo study the expression of telomerase of fibroblasts in the formation and development of scar,and to investgate the relationship between the telomerase activity and the formation and development of scar.MethodsExpression of telomerase was detected by immunohistochemical techniques in 18 specimens from granulation tissue,17 keloid,16 specimens from hypertrophic scar,28 specimens from mature scar,32 specimens from normal skin,and SPSS16.0 statistics software was used to analyze the relationship between telomerase and scar.Results It was shown that the positive expression rate of telomerase in the granulation tissue group was 94.4 ％,that in the keloid group was 58.8 ％,that in the hypertrophic scar group was 18.8 ％, and that in the mature scar and in the normal skin was zero. comparisons between groups,in addition to the normal scar group and normal skin group,other groups were statistically significant differences.ConclnsionsScar formation is a process with multi-factor participation,while telomerase activation is an important factor. Detecting telomerase activity in the development process of scar formation may determine the prognosis.Through the control of telomerase activity in the pathogenesis of scar may become a new approach of scar treatment.

Objective To investigate the effect of carboxyl methyl chitosan on hypertrophic scars by establishing a hypertrophic scar model on the ventral side of rabbit ears.Methods Full-thick-ness excisional wounds,1 cm in diameter,were made in the ears of 12 adult New Zealand white rabbits,and 123 hypertrophic sears were made in all.Then the rabbits were divided into 3 groups:group A was an experimental group (carboxyl methyl chitosan,500μg/ml),group B was a control group 1 (triamcinolone),and group C was control group 2 (physiological saline).All the scars were injected with drugs on the 30th and 40th days after operation,and then the samples were collected on the 35th and 45th day and analyzed.Results Compared with group C,group A appeared to be flatter,softer,and lighter in color;the area density of fibroblast decreased using HE stain and masson stain (P<0.05),and hydroxyproline content and hypertrophic index were also lower than group C (P<0.05).There were no significant differences of those criteria between group A and group B (P>0.05).Conclusion Injection of carboxyl methyl chitosan into Iocal hypertrophic scars On rabbit ears has similar effects to triamcinolone,and both of them can prevent and cure hypertrophic scars in proliferative stage.