Objective To construct the antisense eukaryotic vector of human TRP-1 (tyrosinase related protein 1) encoding gene, and transfect it into TRP-1 highly expressed melanocytes and malignant melanoma cell line, in order to further study the effects of antisense TRP-1 on the proliferation and functions of those cells. Methods TRP-1 cDNA was amplified by polymerase chain reaction (PCR) and the PCR products were subcloned into eukaryotic expression vector pcDNA3.1 on the opposite direction. Antisense recombinant vector was transfected into melanocytes and melanoma cell line. TRP-1 mRNA level was detected by reverse transcriptase polymerase chain reaction (RT-PCR). TRP-1 protein level was detected by Western blot. Cell cycle was determined by flow cytometry. The activity of tyrosinase was valued by L-dopa reaction. Results The recombinant antisense vector pcDNA3.1/TRP-1(-) was constructed. Positive transfected cells could steadily express TRP-1 antisense RNA. It was showed that there was a low level of TRP-1 mRNA as indicated by RT-PCR, and a low level of TRP-1 protein as indicated by Western blot. Cell cycles were blocked in G1 stage. The suppress rates of tyrosinase was 46% in transfected melanocytes and 54% in malignant melanoma cells, respectively. Conclusions TRP-1 plays an important role in the proliferation and functions of melanocytes and melanoma cells. Antisense TRP-1 could block the cell cycles and decrease the activity of tyrosinese in those cells.

Objective To review the clinical-pathological features, the tendency of incidence over 20 years, the predisposing factors, and the differences between the cases of cutaneous malignant melanoma from two hospitals. Methods A collection of 305 cases diagnosed as cutaneous malignant melanoma, among which 185 cases had complete clinical-pathological data, during 1981-2000 was analyzed. Results Acral malignant melanoma accounted for 63.3%, and the cases associated with congenital small nevi at the primary site accounted for 15.8% of 305 patients. During the period 1981-1990 and 1991-2000, cutaneous malignant melanoma constituted 0.053% and 0.094%, respectively, of all diagnoses with pathological sections, with an growth rate of 3.9% yearly. There was a tendency of the increased lesions located on face and neck, and decreased lesions on acra, over 20 years. Conclusion A rise of diagnosis of cutaneous malignant melanoma has been noticed from two hospitals over 20 years. Acra, especially planta, is the predominant anatomical site of cutaneous malignant melanoma.

Objective To study the biomechanical effect of jumping distance on dental implants with socket-shield technique (SST), so as to provide references for clinical standards of jump distance. Methods Based on clinical characteristics, four groups of three-dimensional (3D) SST implant system models with 0, 0. 5, 1 and 1. 5 mm jumping distance were established, and the corresponding material parameters were assigned. The peak stress and stress distributions on models were simulated under specific occlusal condition. Results When the jumpingdistance was non-zero, namely, the implant was not in contact with the retained root fragment, the stress of the implant and abutment increased with the increase of jumping distance, and the peak stress in root fragment and periodontal membrane decreased with the increase of jumping distance. When the jumping distance was zero, the peak stress of the implant, abutment, root fragment and periodontal membrane reached the maximum, far exceeding that of the other groups. Conclusions The jumping distance has a significant effect on the SST implant system. It is recommended to take a larger jumping distance in clinical practices. The edge of the root fragment should be rounded, and the size of the lower edge should not be too small.

Humans ; Thyrotoxicosis/chemically induced* ; Amiodarone