No abstract available.
Sclerosis*

The orchid symbiotic fungi were isolated from the roots of Korean native orchid (Cymbidium goeringii) collected and Chinese orchid (C. sinense) obtained from greenhouses. They were identified as a species of Rhizoctonia, based on the sequences of 18r rDNA, the microscopic observations of mycelia, and the symbiotic relationships with commercial orchids. The isolate collected from Chinese orchids was revealed to be a species of Ceratobasidium endophytica, and to be different from the other isolates at the thickness of the mycelia stained in the root cells of Korean native orchids. The other isolates collected from the Korean native orchids were considered to be a species of Tulsanella repens (anamorphic: Epulorhiza repens) or its related one. The physiologic or microscopic variations were oftenly observed among them, but the tendency of grouping these in the 18s rDNA sequences were observed to be consistent with those of the localities collected. The further taxonomical segregating for Korean symbiotic fungi was not made because the information concerned were limited in this moment, but was recognized as based on the sequences of 18s DNA.
Asian Continental Ancestry Group ; DNA ; DNA, Ribosomal ; Fungi* ; Humans ; Mycorrhizae ; Rhizoctonia ; Symbiosis

No abstract available.
Dental Implantation* ; Dental Implants* ; Osseointegration*

No abstract available.
Centrifugation, Density Gradient* ; Humans* ; Spermatozoa*

No abstract available.
Female ; Obstetric Labor, Premature* ; Pregnancy ; Ritodrine*

Gastrofiberscopic findings under direct vision were analysed in 248 patients who were diagnosed as gastric cancer from Feb. 1980 to March 1983 in Department of internal Medicine, Kang Nam Sacred Heart Hospital, Hallym Medical College, Seoul, Korea. (continue...)
Endoscopy* ; Heart ; Humans ; Internal Medicine ; Korea ; Seoul ; Stomach Neoplasms* ; Stomach*

Germ cell tumors(GCT) are not infrequently encounted tumor in pediartic age group. In order to study the clinical behaviors of the disease, we reviewed 29 cases of GCT diagnosed and treated at Kosin Medical Center in the period of 7 years form Jan. 1984 to Dec. 1991 and the results are summarized as follows: 1) The age distribution is the highest between 10 and 15 years(45%) and girls have 1.9 times higher frequency than that of boys. 2) The most frequent primary site of GCT was ovary(15). The next common primary site was testis(5), pineal body(4), sacrococcygeal region(2), retroperitoneum(1), soft palate(1), anterior mediastinum(1) in descending order of frequency. 3) In the pathological analysis of tumors, the most frequent type was mature teratoma(12). The next common type was endodermal sinus tumor(6), immature teratoma(5), dysgerminoma(3), mixed type(2), and choriocarcinoma(1)in descending order of frequency. 4) All the 5 cases of EST have elevated serum levels of alpha-fetoprotein. Two of the three dysgerminoma, one of the two mixed type tumors both of which have germinoma components, and one choriocarcinoma have elevated serum levels of beta-HCG above the age related physiological levels. 5) Among 17 cases of malignant GCT, 9 cases have metastatic areas such as regional lymph nodes, scrotum, pleura, retroperitoneum, omentum and lumbar spine. 6) All except on case of immature teratoma in the anterior mediastinum underwent surgery. Chemotherapy was given to 12 of 17 malignant GCT and radiotherapy was given to 4 of 17 malignant GCT. 7) Among the 4 expired cases within 12 months of follow up, three were originated from pineal body, which had been underwent simple V-P shunt or incomplete resection, and one case was metastatic immature teratoma of anterior mediastinum to the pleura which had not been undergone surgery. Finally, in review of literature and or cases, the survival of properly managed GCT except some of those difficult surgical access is relatively good. To continue the survival of children of GCT to be impoved, we should use all the treatment modalit properly with more positive outlook about the disease.
Age Distribution ; alpha-Fetoproteins ; Child* ; Choriocarcinoma ; Drug Therapy ; Dysgerminoma ; Endoderm ; Female ; Follow-Up Studies ; Germ Cells* ; Germinoma ; Humans ; Lymph Nodes ; Mediastinum ; Neoplasms, Germ Cell and Embryonal* ; Omentum ; Pineal Gland ; Pleura ; Pregnancy ; Radiotherapy ; Scrotum ; Spine ; Teratoma

All ceramic restorations have had a more limited life expectancy than metal ceramic crowns because of their lower strength. The relatively lower strength has limited the use of all-ceramic crowns to the areas where occlusal loads are lower. Therefore many researches have been done to increase the strength of all-ceramic crowns. IPS Empress 2 is a new type of lithium disilicate glass-ceramic with enhanced physical characteristics which has been in use clinically since 1998. Previous researches reported that the flexural strength of all-ceramic material was greater than 300MPa, and all-ceramic crowns can be used in staining or layering technique. The objective of this study was to investigate the influence of the thickness of IPS Empress 2 ceramic on fracture strength. Both staining technique and layering technique was investigated. Vita VMK was used as control. For all three groups, five specimens each of 0.8mm, 1.0mm, 1.4mm, 1.8mm, and 2.2mm thickness (a total of 75 specimens) were prepared. Control group: Vita VMK Porcelain specimens were prepared with dentine ceramic and liquid glazing was done. Group I: IPS Empress 2 were prepared with staining technique and stained twice and glazed once. Group II : IPS Empress 2 were prepared with layering technique and glazed after wash firing. The thickness and diameter of the specimen were measured and controlled after specimen preparation. Biaxial Flexure Test (ASTM Standard F394-78) was adopted as this test method produces results least affected by the edge condition of the specimens. Fracture strength was measured with Instron Universal Testing Machine. Conclusions are as follow : 1. The fracture strength was increase in order of control group, test group I, test group II. 2. Fracture strength of the group I(Empress 2 Staining) was 65.54 N in 0.8mm, 155.2 N in 1.0mm, 233.5 N in 1.44mm, 434.5 N in 1.8mm, and 600.1 N in 2.2mm. 3. Fracture strength of the group II (Empress 2 Layering) was 190.0 N in 0.8mm, 283.5 N in 1.0mm, 437.2 N in 1.4mm, 732.0 N in 1.8mm, and 1115.0 N in 2.2mm. 4. No statistical difference was found in flexural strengths according to thickness in a specified group(p>0.05).
Ceramics* ; Crowns ; Dental Porcelain ; Dentin ; Fires ; Life Expectancy ; Lithium

The ideal restorative material should mimic the properties of the tissues it replaces. Dental composite resins have been used widely as restorative materials due to its advantages such as excellent esthetics and ease of manipulation. But inadequate wear resistance has been a major factor limiting the use of composite restorative materials. Improved manufacturing techniques have allowed the development of hybrid composites, with a greater percentage volume filler loading, which have improved physical an mechanical properties. However they are lacking the study wear resistance. The purpose of this study was to evaluate the wear of human enamel against ceromer by the use of a pin-on-disk type wear testers. Discs of ceromer(Targis : Ivoclar, Vivadent, Amherst. NY) and discs of type III gold alloy as a control were used for test specimens. Intact cusp of premolar and molar were used for enamel specimens. The wear of enamel was determined by weighing the cusp before and after each test, and the weight converted to volumes by average density of enamel. Surface profilometer was used to quantify wear of the ceromer and gold specimens. Vicker's hardness tester was used to evaluate the surface hardness of test specimens. The SEM was used to evaluate the wear surfaces. The results were as follows; 1. Ceromer produced less enamel wear than gold(p<0.05). 2. The wear volume of ceromer was greater than that of gold(p<0.01). 3. The hardess of ceromer was lower than that of gold, but there was no correlation between the hardness and wear of the ceromer and gold. 4. SEM analysis revealed that there were many voids and microcracks in the wear tract of ceromer. in gold group, many minute V-shaped grooves were examined.
Alloys ; Bicuspid ; Composite Resins ; Dental Enamel* ; Esthetics ; Hardness ; Hardness Tests ; Humans* ; Molar

All-ceramic restorations have become an attractive alternative to porcelain-fused-to-metal crowns. In-Ceram, and more recently IPS Empress 2 were introduced as a new all-ceramic system for single crowns and 3-unit fixed partial dentures. But their strength and marginal fit are still an important issue. This study evaluated the fracture resistance and marginal fit of three systems of 3 unit all-ceramic bridge fabricated on prepared maxillary anterior resin teeth in vitro. The 3 all-ceramic bridge systems were: (1) a glass-infiltrated, sintered alumina system (In-Ceram) fabricated conventionally, (2) the same system with copy-milled alumina cores (copy-milled In-Ceram), (3) a heat pressed, lithium disilicate reinforced glass-ceramic system (IPS Empress 2). Ten bridges of each system with standardized design of framework were fabricated. All specimens of each system were compressed at 55degree at the palatal surface of pontic until catastrophic fracture occurred. Another seven bridges of each system were fabricated with standard method. All of the bridge-die complexes were embedded in epoxy resin and sectioned buccolingually and mesiodistally. The absolute marginal discrepancy was measured with stereomicroscope at x50 power. The following results were obtained: 1. There was no significant difference in the fracture strength among the 3 systems studied. 2. The Weibull modulus of copy-milled In-Ceram was higher than that of In-Ceram and IPS Empress 2 bridges. 3. Copy-milled In-Ceram (112micrometer) exhibited significantly greater marginal discrepancy than In-Ceram (97micrometer), and IPS Empress 2 (94micrometer at P=0.05. 4. The lingual surfaces of the ceramic crowns showed smaller marginal discrepancies than mesial and distal points. There was no significant difference between teeth (incisor, canine) at P=0.05. 5. All-ceramic bridges of three systems appeared to exhibit sufficient initial strength and acceptable marginal fit values to allow clinical application.
Aluminum Oxide ; Ceramics ; Crowns ; Denture, Partial, Fixed ; Hot Temperature ; Lithium ; Tooth