OBJECTIVES: Among chemical and non-chemical dependence, internet addiction is one of the most frequent addictive behavior in adolescent. This study was performed to detect certain temperamental and genetic characteristics in adolescent with internet addiction tendency. METHODS: 87 adolescents with internet addiction tendency (AIT) and 78 adolescents without internet addiction tendency (NAIT) were classified by Young's Internet Addiction Test. Cloninger's Temperament Character Inventory and 6 candidate genes of drug addiction (DRD2 TaqI A, DRD4, DAT1, 5-HTTLPR, NET-8, and COMT) polymorphisms were tested between two groups. RESULTS: Novelty Seeking scores (p=0.001) and Harm Avoidance scores (p=0.042) were significantly higher in AIT. The frequency of DRD2-A1/A1 genotype and G allele of NET-8 in AIT was higher than that in NAIT. In AIT, Novelty Seeking scores were significantly different (p=0.011) according to NET-8 genotypes (G/G>G/A>A/A). CONCLUSION: These data suggest that male adolescents with internet addiction tendency have the specific temperament and genetic polymorphisms like chemical dependence.
Adolescent* ; Alleles ; Behavior, Addictive ; Genotype ; Humans ; Internet* ; Male* ; Polymorphism, Genetic* ; Substance-Related Disorders ; Temperament*

Recently, stereotactic radiosurgery plan is required with the information of 3-D image and dose distribution. A project has been doing if developing LINAC based stereotactic radiosurgery since April 1991. The purpose of this research is to develop 3-D radiosurgery planning system using personal computer. The procedure of this research is based on two steps. The first step is to develop 3-D localization system, which input the image information of the patient, coordinate transformation, the position and shape of target, and patient contour into computer system using CT image and stereotactic frame. The second step is to develop 3-D dose planning system, which compute dose distribution on image plane, display on high resolution monitor both isodose distribution and patient image simultaneously and develop menu-driven planning system. This prototype of radiosurgery planning system was applied recently for several clinical cases. It was shown that our planning system is fast, accurate and efficient while making it possible to handle various kinds of image modalities such as angiography, CT and MRI. It makes it possible to develop general 3-D planning system using beam's eye view or CT simulation in radiation therapy in future.
Angiography ; Computer Systems ; Humans ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging ; Microcomputers* ; Radiosurgery*

PURPOSE: The cyclin-dependent kinase inhibitor p27Kipl is a negative regulator of cell proliferation. Its expression is known to be altered in proteasome-dependent manner without changes in DNA level. Reduced expression of p27Kipl is associated with aggressive behavior in a variety of human cancers. We investigated expression of p27Kipl protein in human breast cancer using immunohistochemistry to assess its biologic implication along with cell cycle analysis by flow cytometry. MATERIALS AND METHODS: We peformed immunohistochemical assay for expression of p27 in total 68 patients with invasive ductal cancer along with 27 benign ductal hyperplasia and 10 ductal carcinoma in situ. The data were analyzed in association with proliferative activity of the same tissues and biologic parameters. RESULTS: In epithelial cells of normal and benign breast disease, expression of p27Kipl was well preserved while its expression markedly decreased in breast cancer (45 of 68). Expression of p27Kipl was significantly reduced in poorly differentiated cancers and in advanced stage of the disease. Levels of p27Kipl expression correlated with cell populations in GO/Gl phase of the cell cycle. In survival analysis, p27Kipl was useful to predict disease-free survival but not overall survival of the patients after adjuvant chemotherapy. CONCLUSION: p27Kipl seems to have a role in cell proliferation and differentiation process during carcinogenesis of breast cancer. The results of present study suggest that p27Kipl can be used in predicting response to systemic chemotherapy in a subset of patients with breast cancer.
Breast Diseases ; Breast Neoplasms ; Carcinogenesis ; Carcinoma, Intraductal, Noninfiltrating ; Cell Cycle ; Cell Proliferation ; Chemotherapy, Adjuvant ; Disease-Free Survival ; DNA ; Drug Therapy ; Epithelial Cells ; Flow Cytometry ; Humans* ; Hyperplasia ; Immunohistochemistry ; Phosphotransferases ; Prognosis