Objective To explore the role of myofibroblasts expressing α-smooth muscle actin (a-SMA) in hyperplastic scar formation.Methods Expression of α-SMA in normal skin and scar was examined by means of immunohistochemistry.The contents of myofibroblasts were measured and com-pared with that of hydroxyproline through cell culture.The contents of precollagen (pc β) , transforming growth factor β (TGF-β) and fibronectin in fibroblasts and myofibroblasts were assayed by ELISA.Results Vascular smooth muscle cells rather than other hypodermal cells expressed α-SMA in normal skin (P<0.01).The expression ofa-SMA was markedly increased up to 96.89% in hyperplastic scar tissues, with statistical difference compared with normal skin (P < 0.01).The contents of hydroxyproline (P <0.01) , pc (P <0.05) , TGF-β (P <0.01) and fibronectin (P <0.05) in myofibroblasts were significantly higher than those in fibroblasts.Conclusion Myofibroblasts play a key role in formation of hypertrophic scar.

With the development of modern medicine,to see a doctor is no longer a simple process of diagnosis or taking drugs.Human have deeply recognized medical science and health from a simple biomedical model to a social,psychological and biomedical model.On the one hand,people seek help from medical science.On the other hand,people fear that malpractice could occur.It has been in a love-hate mentality for people to seek medical and legal relief.In the new era,physician-patient relationship needs to be recognized again from medical staff,patients and legal angles.The combination of medicine and law is the requirement of development of the times.No matter how strong the law is,and no matter how much we hope the legislation is from strength to strength,moderation is still the virtues of the law.Medical perspective is still required in the examination of medical activity.

Objective To investigate the expression changes of paxillin and focal adhesion kinase(FAK) in scar tissues at different periods.Methods The expressions of paxillin and FAK of scar tissue samples from 30 babies at age of 3-12 months were detected by means of immunohistochemistry.Results The expressions of paxillin and FAK in the scar tissues at the 3th and 6th months were increased more significantly than that in normal skin tissues.Whereas,there was no significant difference upon the expressions of paxillin and FAK in the scar tissues at the 12th week compared with normal skin tissues.Conclusion Focal adhesion varies with change of composition,structures and mechanical properties of extracellular matrix(ECM) and with different intracellular framework.Different signal transmissions of ECM,integrin and focal adhesion compound may result in different changes of cellular function.

Objective To assess the deep inferior epigastric perforator (DIEP) vessels in patients with breast reconstruction flaps by contrast-enhanced ultrasound (CEUS) and three-dimensional ultrasound (3DUS) reconstruction techniques.Methods Conventional ultrasound,CEUS and 3DUS were used to evaluate DIEP vessels of breast reconstruction flaps in 43 patients before surgical procedures.The identification,localization and spatial relationship of DIEP vessels were analyzed with conventional ultrasound,CEUS and 3DUS methods.The findings of CEUS and 3DUS were compared to conventional ultrasound and surgical outcome.Results Compared to CDFI,40 cases (93％) were observed more clearly with CEUS,and were showed more accurately than conventional ultrasound.41 cases (95％) could be displayed wonderfully in 3D ultrasound.Perforators which were detected by ultrasound were confirmed in the surgery and the transferred flaps survived completely.Conclusions Perforators can be displayed more clearly and located more accurately by CEUS and 3DUS.CEUS and 3DUS could play a very important role in the preoperative navigation of the DIEP than conventional ultrasound.

Objective To identify the factors related to prognosis of diabetic foot ulcer (DFU).Methods A total of 186 patients with type Ⅱ DFU from a single diabetic foot center was included in this prospective study.Follow-up of the final outcome (healing,major amputation or death) was made in 6 months.Influence of patient demographics and clinical data on outcome was detected using multivariate Logistic regression analysis.Results Follow-up was performed in 172 patients,of whom 147 were cured (55 cases cured after minor amputations),3 underwent major amputations,6 died,and 16 were not yet cured at the final follow-up.In multivariate Logistic regression analysis,the outcome was independently correlated with ischemia (P ＜0.01),infection (P ＜ 0.05),ulcer number (P ＜ 0.01) and peripheral neuropathy (P ＜ 0.05) ; the risk of poor outcome increased with ischemia [odds ratio (OR) =10.8],infection (OR =211.4),ulcer number (OR =39.5),and peripheral neuropathy (OR =181.1).Conclusion Prognosis of DFU is associated with ischemia,infection,ulcer number,and peripheral neuropathy.

Objective To study the effect of mechanical tension on collagen arrangement and illustrate the relationship between tissue architecture and tension properties. Methods Cell morphologies, orientation and collagen arrangement of fibroblasts cultured in three different types of collagen gels with variation of mechanical tension were observed by phase contrast photomicrographs, light microscopy and transmission electron microscopy. Expression and distribution of a-smooth muscle actin (α-SMA) were investigated by immunohistochemistry. Results Phase contrast photomicrographs, light microscopy and transmission electron microscopy showed high level of tension distributed anisotropically in the monolayer gels and the anchored collagen gels, with bipolar shape of the fibroblasts, obvious polarity, arrangement of exogenous collagen fibres parallel to the long axis of the fibroblasts, especially prominent in monolayer gels. Low level of tension distributed isotropically was observed in floating collagen gels, with stellate morphology and arrangement of exogenous collagen fibres in a reticular array. Immunofluorescence showed that fibroblasts expressed high level of α-SMA protein distributed along the long axis of fibroblasts in the monolayer gels and the anchored collagen gels, especially in former ones. In contrast, few expression of α-SMA protein was found in floating collagen gels. Cell morphologies and orientation, expression and distribution of α-SMA as well as collagen arrangement of fibroblasts in the monolayer gels and the anchored collagen gels were similar to those in granulation tissue, whereas floating collagen gels resembled normal dermis or remodelled tissues. Conclusions Tissue architecture or morphology of the dermis are corresponding to tension proporties. Different tissue architectures are closely correlated with particular tension proporties.

Objective To explore the repair method for refractory diabetic wound. Methods A total of 206 patients with refractory diabetic foot ulcers were treated with proper surgical treatments.Results Of all, 106 patients were treated by skin flap (51.5 % ), with one stage wound healing rate of 85.8%; 122 patients were repaired with split-thickness skin graft ( 59.2% ), with survival rate of the graft for 79.5%. Simple toe amputation was made in 34 patients (46 toes). The high level amputation was performed in 56 patients (27.2%). Of all, 132 patients were followed up for 6-18 months, which showed that ulcer recurred in 12 patients (9.1%). Conclusion Timely and effective treatment as well as flap and skin graft repair could reduce high level amputation rate of diabetic foot ulcer and promote the quality of life.

Objective To detect the histological characteristics of collagen nodules from hypertrophic scars (HS) and investigate the origin of collagen nodules.Methods The scar tissues were collected from patients with plastic operation.Morphological characteristics of collagen nodules were observed by light microscopy of HE-stained sections; expressions of type Ⅰ /Ⅲ collagens were observed by polarized light microscopy of sirius red-stained sections; expression and distribution of myofibroblasts (MFb)-specific protein (α-smooth muscle actin,α-SMA) were observed by immunostaining in order to observe level of local tissue tension.Results Collagen nodules varied in shape,not only sphereshaped,and in size.Moreover,abundant fibroblasts (Fb) with large and light-stained nuclei were seen in the nodules compared to non-nodule area,indicating that the cells located in the modules were active.Some collagen nodules were composed largely of collagen type Ⅲ (green),but some mainly contained collagen type Ⅰ (red or yellow),indicating the difference in the time of nodule formation.α-SMA was expressed mainly in the deep dermis equivalent to the level of reticular layer of the new scar tissues (2 months after injury) ; α-SMA was expressed mainly in the nodules of the old scar tissues (2-10 years after injury),but almost not in non-nodule areas except for a strongly positive staining in the vessels.Moreover,α-SMA presented a heterogeneous distribution in the collagen nodules,with stronger expression in the epidermal end than in the subcutaneous tissue end and stronger expression in the superficial dermis than that in the deeper part.It was suggested that there existed massive amount of MFb and high tension in the nodules arid that the tension distribution was not uniform in or between the nodules.Conclusions Collagen nodules are of varying shape and size and collagen types are associated with the time of nodule formation.Moreover,Formation of the collagen nodules may be closely related to the distribution and evolution of the local tissue tension.

Four weeks after SD diabetic rats were induced by streptozotocin,skin thickness was obviously reduced with obscure multilayer epithelium features.Moreover,the thickness of epidermic layers in diabetic rat skin was significantly thinner than that ofnornlal rat skin at the eighth week[(0.016±0.006 vs 0.041±0.007)mm,P<0.01].The percentage of G2/M phase cells in epidermic layers of diabetic group was significantly lower than that in the normal group.At the twelfth week,skin microangiopathy was easily detected in the diabetic group.The blood levels of advanced glycation end products(AGEs)and malonialdehyde were significantly increased and glutathione decreased in diabetic rats compared with control rats(aU P<0.01),along with the increased contents of local glucose and AGEs in the skin of diabetic rats.These results suggest that the local accumulation of glucose and AGEs seems to be one of the important mechanisms in the pathogenesis of diabetic skin lesions.

AIM: To explore the histochemical changes o f diabetic skin and the pathogenesis of impaired wound healing in diabetes. METHODS: 54 male Sprague-Dawley (SD) rats weighing 200-220 g wer e randomized into control and STZ-induced diabetic groups. The shaved skin speci mens from the back of rats were collected in 4, 8 and 12 weeks post STZ-inductio n, respectively. Hematoxylin-eosin dye was used for histological examination. Me a nwhile, the skin glucose contents were measured by Beckman's autoanalyzer. Skin AGEs concentrations were assessed by detecting total fluorescence in tissue coll agen and immunohistochemistry assay. RESULTS: The skin thickness in diabetic animals was decreased, w ith the features of multilayer epithelium structure disappeared in epidermis and collagen fibers atrophied, swollen and degenerated in dermis; The inflammatory responses in the dermis of diabetic animals were increased obviously. The result s also revealed that skin glucose contents in diabetic rats [(2.64?1.03)mg/ g skin] were 2-3 times higher than those in the controls [(0.74?0.33)mg/g s kin] (P