2.Influence of Thickness of Empress 2 Ceramic on Fracture Strength.
Jung Woo KOH ; Jae Ho YANG ; Sun Hyung LEE
The Journal of Korean Academy of Prosthodontics 2000;38(4):446-460
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
3.The Expression of L-type Calcium Channel mRNA by the Concentrations of Glucose on the Cell Proliferation in Cultured OLETF Rat Aortic Vascular Smooth Muscle Cells.
Hyung Joon YOO ; Young Jung CHO ; Hong Woo NAM
Journal of the Korean Geriatrics Society 2004;8(4):191-195
BACKGROUND: The proliferation of vascular smooth muscle cell(VSMC) is a part of the major pathogenic mechanism for atheroscle- rosis. It has been reported that L-type calcium channel plays a role in the VSMC proliferation in diabetic rats. But there is a little study results about the association between L-type calcium channel and VSMC proliferation by glucose concentrations in culture media. So we examined the association between voltage-dependent L-type calcium channel of VSMCs and the proliferative activity of vascular smooth muscle cells. METHODS: Rat aortic VSMCs were isolated from the aorta of OLETF rat by enzyme method. VSMCs were cultured in various concentrations of glucose(5.5, 25 mM). The VSMCs(1x104 cells in 24-well plates) were incubated in the presence of Bay K 8644 (10-6M) with/without verapamil(10-6M) for 48 hours. Then the proliferation was assessed by MTT(methylthiazole tetrazolium) assay and expression of L-type calcium channel mRNA was measured by RT-PCR. RESULTS: The proliferative ability and the expression of L-type calcium channel of cultured VSMCs were increased dose-dependently by the glucose concentrations(p<0.05). Bay K 8644 enhanced the proliferation of VSMC and verapamil blocked the incremental effects induced by Bay K 8644. CONCLUSION: These results suggest that L-type calcium channel may play a role in VSMC proliferation of OLETF rat.
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester
;
Animals
;
Aorta
;
Calcium Channels, L-Type*
;
Cell Proliferation*
;
Culture Media
;
Glucose*
;
Muscle, Smooth, Vascular*
;
Rats
;
Rats, Inbred OLETF*
;
RNA, Messenger*
;
Verapamil
4.The Effects of Dimethly Sulfoxide and Sodium thiosulfate for the Prevention of Tissue Necrosis due to Extravasation of Mitomycin-C.
Sang Hyun WOO ; Byung Cheol CHOI ; Ki Hyung KIM ; Jung Hyun SEUL ; Tae Eun JUNG
Yeungnam University Journal of Medicine 1996;13(2):243-250
Extravasation of toxic chemotherapeutic 'agents cause severe skin ulceration and necrosis which often need secondary surgical intervention. Still, there were not established antidote agent in case of extravasation with mitomycin-c. Dimethyl sulfoxide is known as an effective chemical scavenger of toxic hydroxyl free radical and sodium thiosulfate also was demonstrated significant protector from mitomycin-c induced ulceration by a few experimental studies. Author investigated necrotic area of mitomycin-c injected site and compare to the effectiveness of topical treatment with dimethyl sulfoxide and intradermal injection of sodium thiosulfate according to starting times, forty five mice were divided into 3 groups. Control group(n=5) had no treatment after subcutaneous injection of mitomycin-c. Experimental group I and 11 were 20 mice treated dimethyl sulfoxide and sodium.
Animals
;
Dimethyl Sulfoxide
;
Injections, Intradermal
;
Injections, Subcutaneous
;
Mice
;
Mitomycin*
;
Necrosis*
;
Skin Ulcer
;
Sodium*
;
Ulcer
5.A Case of Polyarteritis Nodosa Combined with Dilated Cardiomyopathy.
Hee Jung CHOI ; Seong Ae JUNG ; Eun Young LEE ; Hae Kyung JUNG ; Gil Ja SHIN ; Woo Hyung LEE
Korean Circulation Journal 1994;24(4):668-674
Polyarteritis nodosa is systemic necrotizing vasculitis of medium and small-sized arteries and results in variable manifestations due to ischemia of the involving organs. Diagnosis can either be made pathologically by demonstrating necrotizing vasculitis of arteries or angiographycally by demonstrating small arterial aneurysm. We experienced a case of PAN with dilated cardiomyopathy, confirmed by clinical feature, renal biopsy, angiography and echocardiography.
Aneurysm
;
Angiography
;
Arteries
;
Biopsy
;
Cardiomyopathy, Dilated*
;
Diagnosis
;
Echocardiography
;
Ischemia
;
Polyarteritis Nodosa*
;
Vasculitis
6.Diagnostic accuracy of stable microbubble rating test for the early detection of neonatal respiratory distress syndrome.
Jung Sam JUN ; Chy Hyung PARK ; Jong Woo BAE ; Chang Il AHN
Journal of the Korean Pediatric Society 1992;35(10):1361-1368
No abstract available.
Microbubbles*
;
Respiratory Distress Syndrome, Newborn*
7.Comparison of Thallium-201 Scan and Tc-99m Sestamibi Scan in the Differential Diagnosis of Breast Mass.
Hyung Woo LEE ; Ihn Ho CHO ; Kyu Jang WON ; Soo Jung LEE
Korean Journal of Nuclear Medicine 1999;33(1):76-83
PURPOSE: We performed this study to compare T1-201 and Tc-99m MIBI scans for the differentiation of malignant from benign breast mass. MATERIALS AND METHODS: Thirty-eight female patients underwent T1-201 breast scan and thirty-two of them also underwent Tc-99m MIBI scan of the breast. After intravenous injection of 74-111 MBq of T1-201, early (10 minutes) and delayed (3 hours) images were obtained. Then, 555-740 MBq of Tc-99m MIBI was injected and images after 30 minutes were obtained. We compared T1-201 and Tc-99m MIBI scans with pathologic RESULTS. RESULTS: Twenty-three patients were confirmed to have infiltrating duct carcinoma and fifteen patients to have benign breast mass by excisonal biopsy. The sensitivity of early and delayed T1-201 scan and Tc-99m MIBI scan in the detection of malignant breast lesion were 100% (23/23), 82% (18/22), and 90% (18/20), respectively. The specificity of early T1-201 scan was significantly higher than that of delayed T1-201 scan (p<0.05). The specificity of early and delayed T1-201 scan and Tc-99m MIBI scan were 73% (11/15), 73% (11/15) and 83% (10/12), respectively (p:not significant). Three patients out of nine with fibroadenoma and one patient with atypical duct hyperplasia were false positive in both early and delayed T1-201 scans. The size of fibroadenoma with false positvie in early and delayed T1-201 scan (4 cases) was larger than that of 11 fibradenoma with true negative scan (p<0.01). Metastatic axillary lymph node involvement was present in fifteen patients. The sensitive to detect metastatic nodes was 38% (5/13) for early T1-201 images, 15% (2/13) for delayed T1-201 images, 58% (7/12) for Tc-99m MIBI planar images and 67% (4/6) for Tc-99m MIBI SPECT. The sensitive of Tc-99m MIBI planar or SPECT was significantly higher than that of delayed T1-201 images (p<0.05). CONCLUSION: Early T1-201 and Tc-99m MIBI scan are useful noninvasive methods to differentiate malignant form benign mass of breast. Tc-99m MIBI scan was sensitive in detecting axillary lymph node metastasis in patients with brease cancer.
Biopsy
;
Breast Neoplasms
;
Breast*
;
Diagnosis, Differential*
;
Female
;
Fibroadenoma
;
Humans
;
Hyperplasia
;
Injections, Intravenous
;
Lymph Nodes
;
Neoplasm Metastasis
;
Radionuclide Imaging
;
Sensitivity and Specificity
;
Tomography, Emission-Computed, Single-Photon
8.Correlation between Expression of p53 and Bcl-2 Protein and Epstein-Barr Virus Detection in Gastric Adenocarcinoma.
Ki Jung YUN ; Weon Cheol HAN ; Hyung Bae MOON ; Sang Woo JUHNG
Korean Journal of Pathology 1998;32(8):574-580
Epstein-Barr virus (EBV) has been known to be associated with a wide variety of neoplastic conditions including nasopharyngeal carcinoma, Hodgkin's disease, and non-Hodgkin's lymphoma. Recent studies reveal the presence of EBV in certain subtypes of gastric carcinoma in which EBV appears to be pathogenetically related. To evaluate the relationship between EBV and gastric adenocarcinoma, we examined EBV DNA using direct in situ polymerase chain reaction, and expression of p53 protein and bcl-2 protein using immunohistochemical staining method on paraffin embedded tissues. The materials consisted of one hundred twenty-eight gastric adenocarcinomas and twenty benign peptic ulcers. EBV DNA was detected in 14 of 128 gastric adenocarcinomas (10.9%). p53 protein was positive in 10 of 14 EBV positive adenocarcinomas (71.4%) and in 61 of 114 EBV negative adenocarcinomas (53.5%). Bcl-2 protein was positive in 2 of 14 EBV positive adenocarcinomas (14.3%) and in 19 of 114 EBV negative adenocarcinomas (16.7%). The above results indicate that EBV is associated with gastric adenocarcinoma, and p53 protein may play a role in carcinogenesis of EBV in gastric adenocarcinoma.
Adenocarcinoma*
;
Carcinogenesis
;
DNA
;
Herpesvirus 4, Human*
;
Hodgkin Disease
;
Lymphoma, Non-Hodgkin
;
Paraffin
;
Peptic Ulcer
;
Polymerase Chain Reaction
9.Santonin-kainic acid complex as a mass chemotherapeutic of Ascaris lumbricoides control in Korea.
Soon Hyung LEE ; Se Chul KANG ; Jong Ho AHN ; Jung Woo LEE ; Han Jong RIM
The Korean Journal of Parasitology 1972;10(2):79-85
Santonin-kainic acid complex was evaluated as a chemotherapeutic of the mass treatment of the Ascaris lumbricoides infection in Korea. The results could be summarized as follows: The negative conversion rate was 82.9% in average in 4 treated groups. Some variations of negative conversion rate among the treated groups were noticed. The egg reduciton rate was 97.7% in average and the results were rather uniform among the three evaluated groups. By the analysis of egg reduction, it seems that the lightly infected cases whose E.P.G. were under 5,000 were resistant to treatment with the less reduced egg output. After the treatment with this complex, the number of egg discharged cases were reduced to 1.84% and the average number of discharge eggs per incompletely treated or untreated cases were reduced to 12.5% compared with the level of before-treatment egg output. The successive observations of the pattern of worm expulsion after drug intake was made. The worms were mostly expelled in the stool within 3 days, and 58.9% of total expelled worms were collected within 24-hour stool. The minimum length of the immature worms expelled was 7.6cm. Among the 659 Ascaris collected in the first-day stool from 91 rural people, 8.5% were in the range of 7.6-12.2 cm-long, immature worms. The sex ratio, male: female= 0.69: 1.
parasitology-helminth-nematoda
;
Ascaris lumbricoides
;
chemotherapy
;
Santonin
;
kainic acid
10.2 Cases of Bacterial Intracranial Aneurysm.
Jong Woo HAN ; Jin Myung JUNG ; Hyung Jin SHIN
Journal of Korean Neurosurgical Society 1991;20(12):1102-1109
The authors experienced 2 cases of bacterial intracranial aneurysm, the mortality of which has been reported to by very high and the management of which is controversial. Some authors have recommended observation with serial angiography during antimicrobial therapy and surgery for aneurysms that enlarge or remain patent. Others have argued for promt surgical removal. Bothof our patients had multiple aneurysms and were treated with appropriate, high-dose antibiotics, but intracerebral homorrhage(ICH) occurred during antibiotiecs treatment in both cases and they underwnet emergent operation, but both died.
Aneurysm
;
Angiography
;
Anti-Bacterial Agents
;
Humans
;
Intracranial Aneurysm*
;
Mortality