ABSTRACT
Objective To investigate the performance of surgical management in facial skin malignancies.Methods From January 2000 to December 2006,65 patients with facial skin malignancies,including47 cases of basal cell carcinoma.10 cases of squamous cell carcinoma,3 cases of dermatofibrosarocoma protuberans,2 cases of malignant melanomas,and one case of malignant acanthoma,hemangioendotheliosar-coma and sebaceous carcinoma,respectively,were collected and managed with wide resection followed by reconstruction.In order to achieve a thorough resection,frozen sections were prepared and subjected to pathological examination during the operation process to ensure the margins of resection were free of malignancy.Reconstruction was carried out by direct closure,or with local random flaps,extended flaps,free skin grafts.Resuits All defects were managed by one-stage reconstruction.The survival rate of skin flaps/grafts was 100%,and a satisfactory appearance and function was achieved.During the follow-up from 6 months to 5 years,local relapse was observed in one patient with basal cell carcinoma and one with squamous eell carcinoma,lymphatic metastasis in one with squamous cell carcinoma.Distant metastasis occurred in a patient with malignant melanoma.who died consequently.Conclusions Thorough resection is the key to prevent relapse of facial skin malignancies after surgery.Appropriate reconstruction may favor the restoration of facial appearance,and local random flaps appear to be the best reconstruction strategy.
ABSTRACT
Objective To understand the molecular mechanism underlying the epidermal growth factor receptors(EGFR)signal transduction and its feed-back regulation.Methods Two human keratinocyte cell lines,HaCaT and CHOwt,were cultured and treated with a certain concentration of different ligands,including epidermal growth factor(EGF),heparin-bounding(HB)-EGF,transforming growth factor α (TGFα)and heregulin(HER),for various durations(2,4,8,16,20 hours).After the treatment,cells were collected and protein was extracted.The amount of total and active EGFR was measured by immunoprecipitation and immunoblot assay.The internalization and down-regulation of EGFR were visualized with immunofluorescence and laser seanning confocal microscopy.Results As shown by immunoblot technique,EGF and HB-EGF continuously down-regulated the total amount of EGFRs,whereas TGFα and HER had no significant effect on the degradation of EGFRs.The activation of EGFRs was also attenuated to different extent after long-time treatment with EGF,HB-EGF and TGFα.As indirect immunofluorescenee revealed,in untreated HaCaT and CHOwt cells,EGFRs were essentially located at the plasma membrane,with a little cytosolic distribution;after ten-minute treatment with EGF,EGFRs clustered into patch-like structures which were particularly obvious in HaCaT cells,and translocated into cytoplasmic vesicles resembling endosomes (relatively apparent in CHOwt cells),while the total amount of EGFRs remained constant in these cells.The fluorescence signal from the total EGFRs decreased evidently after four-hour treatment with EGF,indicating a strong reduction in the receptors.Conclusions EGF and HB-EGF,but not TGFα or Heregulin,could down-regulate the amount of total and active EGFRs.There might be different mechanisms for the signal transduction related to EGFRs intemalization and down-regulation between HaCaT and CHOwt cells.