STATEMENT OF PROBLEM: Titanium-Nickel alloy might be used in various prosthetic restorations since it has a unique property such as super-elasticity and high fatigue resistance. However, little is known about the casting ability of this alloy. PURPOSE: This in vitro study compared the casting accuracy and the porosity made with different investments and various sprue designs to ascertain what casting condition would be better for the fabrication of Ti-Ni cast restorations. MATERIAL AND METHODS: A total of 70 Ti-Ni alloy crowns were made and divided into 7 groups of 10 copings on a metal master die. For measuring the effect of the sprue numbers, two groups with one and two 8-gauge sprues were compared. Moreover, the results of the conventional sprue and the double thickness sprues were compared. Three investments were used; carbon free phosphate bonded investment, titanium investment and gypsum bonded investment. The cast restorations were evaluated at 48 points on the entire circumferential margin with a stereomicroscope measuring in micrometers. Each crown was radiographically examined for casting defects and porosity. Data on casting accuracy were analyzed using two-way and Post hoc Scheffe's comparison to determine whether significant differences existed at the 95% confidence level. Student-Newman-Keuls test were performed to identify significant differences in the number of voids. RESULTS: The double sprueing group and double thickness group had significantly less marginal discrepancy than the single sprueing group (P<.05 and P<.01, respectively). The castings with phosphate bonded investment showed the least marginal discrepancy and the smoothest surface. The castings invested in the gypsum bonded investment had the greatest gaps in margin and the largest failure rate. The double sprueing group and phosphate bonded investment group had significantly smaller void numbers and smaller void size than the other groups. CONCLUSION: Within the limitations of this in vitro study, the casting accuracy of the groups using thicker, double sprue design and the phosphate bonded investment was significantly superior. Moreover, void number and size were less than other groups.
Alloys ; Calcium Sulfate ; Carbon ; Celiac Disease ; Crowns ; Fatigue ; Investments ; Porosity* ; Titanium

No abstract available.
Female ; Humans ; Karyotyping* ; Pregnancy ; Pregnancy Trimester, Third*

No abstract available.
Endometrial Neoplasms* ; Female ; Ovary*

No abstract available.
Ileus* ; Lymph Nodes*

We reviewed 86 thymic epithelial tumors and reclassified them according to the Kirchner and Muller- Hermelink classification. They were subtyped as medullary, mixed, predominantly cortical (organoid), cortical, well differentiated thymic carcinoma, and poorly differentiated thymic carcinoma. The frequency of each subtype was determined and histologic findings were related to stage and myasthenia gravis. Immunohistochemical stains for bcl-2 protein as a marker for medullary thymocytes and MIC-2 protein as a marker for cortical thymocytes were performed in each case. The stages and association of myasthenia gravis was significantly different in each subtypes. The results of this study demonstrate that this histogenetic classification is clinically applicable. The bcl-2 protein was specifically demonstrated in lymphocytes within areas of medullary differentiation and MIC-2 protein in cortical differentiation. The expression of bcl-2 and MIC-2 proteins lend histogenetic support for this new classification of thymoma. Bcl-2 protein is strongly expressed in tumor epithelial cells of every case of poorly differentiated thymic carcinoma whereas the other types of thymic epithelial tumors do not show epithelial expression of this protein. The strong expression of bcl-2 protein in tumor epithelium may be considered as a predictor of aggressive behavior in thymic epithelial tumors.
Classification ; Coloring Agents ; Epithelial Cells ; Epithelium ; Lymphocytes ; Myasthenia Gravis ; Staphylococcal Protein A ; Thymocytes ; Thymoma*

No abstract available.
Twins, Conjoined*

BACKGROUND: Melanocytes grown in pure monolayer culure lack many of the cellular interactions that exist in vivo. This can be partially overcome by growing melanocytes together with other epidermal cells in skin equivalent models. OBJECTIVE: The objective of the present study was to grow human melanocytes in human epidermis reconstructed on dermal substrates in vitro and to examine their response to UV radiation. METHODS: The skin equivalents were prepared by seeding cultured human keratinocytes together with cultured human melanocytes(in a ratio of 5%) onto de-epidermized dermis. After 7 days of culture, they were exposed to UVB irradiation(total 150m J/cm over 5days). On day 12 of air exposure the sections of the skin equivalents were prepared for histology. The structure of the skin equivalents was studied following staining with hematoxylin and eosin. Melanocytes were characterized by DOPA staining and by immunohistochemistry. RESULTS: Melanocytes were localized singly within the basal layer of the reconstructs. Melanin was also visible both in the melanocytes and in neighboring keratinocytes. There was an increase in melanocyte size and dendricity following UV irradiation. Melanocytes became positive to staining with HMB-45 antibody following UV irradiation. CONCLUSION: Our results indicate that melanocytes grown in reconstructed human epidermis are functional and capable of responding to UV irradiation.
Dermis ; Dihydroxyphenylalanine ; Eosine Yellowish-(YS) ; Epidermis* ; Hematoxylin ; Humans* ; Immunohistochemistry ; Keratinocytes ; Melanins ; Melanocytes* ; Skin

Conical crown-retained denture (CCRD) has been used as a very effective treatment method in cases with few remaining teeth with heterogeneous prognosis. However, in spite of many advantages of CCRD, high technical failure rate was a problem to be considered. Incorrect path of insertion and excessive retention were thought to be the main cause of technical failure and to result from laboratory procedure with a coping misfit and/or a coping transfer error. In order to prevent this error, secure anchoring of inner coping and re-examination and milling of convergence angle were recommended on the master model from pick-up impression.
Dentures* ; Prognosis ; Tooth

Familial polyposis is inherited as an autosomal dominant trait. It is characterized by the progressive development of hundreds to thousands of adenomsteus polyps in the large intestine. A patient who inherited the gene for familial polyposis is asually asymptomatic until after puberty, at which time polyps begin to appear. The disease at first non-malignant but after an interval of a few months or years, the development of colon cancer is inevitable. In Korea, several cases were reported, but almost all of the cases had incomplete familial histories. We experienced one case of familial polypasis in 33-year old Korean male who had no malignant changes in the adenomatous polyps. Among his family, his father and his brother have adenomatous polps in the colon and the rectum confirmed through total colonoscopy with biopsy. We report a case of familial polyposis of colon with a brief review of literatures.
Adenomatous Polyposis Coli* ; Adenomatous Polyps ; Adolescent ; Adult ; Biopsy ; Colon* ; Colonic Neoplasms ; Colonoscopy ; Fathers ; Humans ; Intestine, Large ; Korea ; Male ; Polyps ; Puberty ; Rectum ; Siblings

No abstract available.