1.The evaluation of the removal torque and the histomorphometry of the Ca-P coating surface in rabbit tibia.
Myeong Bae KWAK ; Cheong Hee LEE
The Journal of Korean Academy of Prosthodontics 2004;42(5):556-571
STATEMENT OF PROBLEM: Surface texture of the implant is one of the important factors of the implant success, especially in the immediate implant loading. Many methods of the surface treatment of implant have developed and introduced. PURPOSE: This study was to evaluate the effects of the Ca-P coating implant crystallized the hydroxyapatite on the surface by the removal torque test and the histomorphometric analysis in vivo. Material and methods: 135 screw type implants, 4.0mm in length and 3.75mm in diameter were used in this study. Implants were divided into 3 groups and treated in the different methods. Group I was not treated, Group II was treated in the SLA method, and Group III was treated in the Ca-P coating with the anodizing method and the hydroxyapatite was crystallized on the surface with the hydrothermal treatment. Firstly, the surface roughness of each group was measured. 45 rabbits were used in this experiment. Two implants were inserted on right tibial metaphysis and one implant was inserted on left side with the alternating order. After the healing periods of 3, 5, and 12 weeks, the rabbits were sacrificed to evaluate the osseointergration by the removal torque test and the histomorphometric analysis. RESULTS: 1. In the analysis for the surface roughness, Group II showed the highest roughness. And Group III showed higher secondly. There was a significant difference one another statistically. 2. In the removal torque test, Group III and II were significantly higher than Group I. There was no statistical difference between Group III and Group II. 3. For all Groups, the removal torque values at 12th week were significantly higher than at 3rd and 5th week. 4. In histomorphometric analysis, the bone implant contact rates of Group III and II were higher than that of Group I at 3rd and 5th week. There was a significant difference at 5th week. 5. In histomorphometric analysis, the bone implant contact rate of Group III and II increased from 3rd week to 5th week, but decreased at 12th week. In Group I, the contact rate at 12th week was significantly higher than at 3rd week and 5th week.
Durapatite
;
Rabbits
;
Tibia*
;
Torque*
2.Transcatheter Closure of Patent Foramen Ovale in a Stroke Patient under the Guidance of Transesophageal Echocardiography.
Sang Sig CHEONG ; Sang Gon LEE ; Myeong Ki HONG ; Seong Wook PARK ; Seung Jung PARK
Korean Circulation Journal 1996;26(3):731-733
Interest in the prevalence of patent foramen ovale(PFO) and its relation to embolic stroke has increased with the sophistication of methods for noninvasive cardiac assessment. The effect of foramen ovale closure on the risk for subsequent strokes is promised. A 22-year old woman was presented with sudden onset of cerebral infarct. She had a patent formen ovale, and right to left shunt during the Valsalva maneuver, which was diagnosed by transesophageal contrast echocardiography. Transcatheter closure of PFO was performed with Rashkind PDA umbrella under the guidance of transesophageal echocardiography. Transcatheter closure of PFO can be accomplised with little morbidity and may reduce the risk of embolic episode.
Echocardiography
;
Echocardiography, Transesophageal*
;
Female
;
Foramen Ovale
;
Foramen Ovale, Patent*
;
Humans
;
Prevalence
;
Stroke*
;
Valsalva Maneuver
;
Young Adult
3.Simple Renal Cyst.
Jung Geon LEE ; Myeong A CHEONG
Korean Journal of Nephrology 2011;30(4):429-433
No abstract available.
4.Effect of the marginal position of prosthesis on stress distribution of teeth with abfraction lesion using finite element analysis.
Myeong Hyeon KIM ; Cheong Hee LEE
The Journal of Korean Academy of Prosthodontics 2014;52(3):202-210
PURPOSE: The aim of this study was to evaluate the stress concentration and distribution whether restoring the cavity or not while restoring with metal ceramic crown on tooth with abfraction lesion using finite element analysis. MATERIALS AND METHODS: Maxillary first premolar was selected and made a total of 10 finite element model. Model 1 was natural tooth; Model 2 was tooth with metal ceramic crown restoration which margin was positioned above 2 mm from CEJ; Model 3 was tooth with metal ceramic crown restoration which margin was positioned on CEJ; Model 4 was natural tooth which has abfraction lesion; Model 5 and 6 had abfraction lesion and the other condition was same as model 2 and 3, respectively; Model 7 was natural tooth which had abfraction lesion restored with composite resin; Model 8 and 9 was tooth with metal ceramic crown after restoring on abfraction lesion with composite resin; Model 10 was restored tooth on abfraction lesion with composite resin and metal ceramic crown restoration which margin is positioned on lower border of abfraction lesion. Load A and Load B was also designed. Von Mises value was evaluated on each point. RESULTS: Under load A or load B, on tooth with abfraction lesion, stress was concentrated on the apex of lesion. Under load A or load B, on tooth that abfraction lesion was restored with composite resin, the stress value was reduced on the apex. CONCLUSION: In case of abfraction lesion was restored with composite resin, the stress was concentrated on the apical border of restored cavity regardless of marginal position. It was favorable to place crown margin on the enamel for restoring with metal ceramic crown.
Bicuspid
;
Ceramics
;
Crowns
;
Dental Enamel
;
Dental Stress Analysis
;
Finite Element Analysis*
;
Prostheses and Implants*
;
Tooth Cervix
;
Tooth*
5.Recognition of Patients, Families, Nurses, and Physicians about Clinical Decision-making and Biomedical Ethics.
Ae Ran PARK ; Hyang Sook SO ; Myeong Cheong CHAE
Asian Oncology Nursing 2014;14(1):23-31
PURPOSE: To identify the recognition of patients, families, nurses, and physicians about clinical decision-making and biomedical ethics. METHODS: Data were collected from October 23 to 30, 2012 using the structured questionnaires. A total of 200 data were analyzed using SPSS 20.0 version. RESULTS: Response about 'who should receive the first notice of a cancer diagnosis?' was significant difference statistically. Cancer patients had preferences to be notified their diagnosis first. Patients responded the person who made decision of treatment options would be physician first and then themselves. Families, nurses, and physicians answered that decision-maker would be both of patient and family. All four groups answered that the person who made decision about care-giver after discharge was patient and their family. Nurses and physicians who didn't aware of the advanced directive were over 30.0%, and patients and family who didn't aware of that were over 60.0%. Lastly, the rate of positive answer about making attempt of advanced directive after legalization was over 80.0%. CONCLUSION: Patient's attitude about making decisions is different from family's attitude. Nurses and physicians have to put emphasis on the patient's autonomy & self-determination and family members' needs.
Bioethics*
;
Diagnosis
;
Humans
;
Surveys and Questionnaires
6.A Prospective, Randomized, Comparative Clinical Investigation of the Effects of Sulodexide on Restenosis after Percutaneous Transluminal Coronary Balloon Angioplasty.
Jin Woo KIM ; Cheol Whan LEE ; Sang Sig CHEONG ; Duk Hyun KANG ; Myeong Ki HONG ; Jae Kwan SONG ; Jae Joong KIM ; Seong Wook PARK ; Seung Jung PARK
Korean Circulation Journal 1997;27(6):644-651
BACKGROUND: Restenosis remains as the major limitation of percutaneous translumainal coronary balloon angioplasty (PTCA). Although its mechanism remains incompletely understood, proliferative action of arterial smooth muscle cells has been found to play an important role on restenosis by neointimal formation after PTCA. Glycosaminoglycan-containing compounds, including Sulodexide (Vessel Due , ALFA, Wasserman, S.p.A, Italy), inhibit the proliferation and maigration of vascular smooth muscle cells in vitro. OBJECTIVES: This study was performed to assess the efficacy of Sulodexide, a glycosaminoglycan compound with antithrombotic and antiproliferative properties, in preventing restenosis after PTCA. METHOD: Two hundred eighty-four patients with ischemic heart disease were randomized to receive either the standard PTCA without Sulodexide in 144 patients (control group, M : F = 99 : 45, Age = 58 +9 or -9), 160 lesions or the standard PTCA with Sulodexide in 140 patients (treated group, M : F = 89 : 51, age = 58 +10 or -10), 158 lesions. Successful angioplasties were performed in 258 atheromatous coronary lesions in 224 patients for whom follow-up angiographic data were obtained 6 month later. Quantitative coronary angiographic analysis (QCA) was performed before , immediate after PTCA and 6-month later. Angiographic restenosis (>50% diameter stenosis at follow-up) was the primary end point : miniamal luminal diameter at follow-up angiogram was the secondary end point. RESULT: Successful PTCA was 97.6% and 97.5% in the standard PTCA with Sulodexide and the standard PTCA without Sulodexide, respectively. Although reference vessel size and minimal luminal diamater after PTCA were larger in the control group than in the Sulodexide group(2.94+0.11 or-0.11 vs 2.83+0.13 or -0.13 mm and 2.26+0.12 or -0.12 vs 2.18+0.08 or -0.08 mm, respectively, p=NS), there was a increased tendency of minimal lumen diameter at 6 months angiogram in the Sulidexide group than in the control group (1.12+0.50 or -0.50 vs 1.07 + 0.53 or -0.53 mm, respectively, p=NS). Angiographic restenosis occured in 42% of lesions in the Sulodexide group and 52% of the control group (p=NS). CONCLUSIONS: Sulodexide treatment had a tendency to reduce restenosis rate in 6 months after coronary angioplasty. However, further study is necessary to verify the antiproliferative effect of Sulodexide with much larger number of patients.
Angioplasty
;
Angioplasty, Balloon, Coronary*
;
Constriction, Pathologic
;
Follow-Up Studies
;
Humans
;
Muscle, Smooth, Vascular
;
Myocardial Ischemia
;
Myocytes, Smooth Muscle
;
Phenobarbital
;
Prospective Studies*
7.Increased Basal Coronary Artery Tone and Hyperresponsiveness to Acetylcholine and Ergonovine in Spasm Related Coronary Artery in Patient with Variant Angina.
Seung Jung PARK ; Seong Wook PARK ; Jae Joong KIM ; Jae Kwan SONG ; Myeong Ki HONG ; Duk Hyun KANG ; Sang Sig CHEONG ; Jong Koo LEE
Korean Circulation Journal 1994;24(6):928-936
BACKGROUND: In patients with variant angina, previous data have been inconclusive as to whether basal coronary artery tone is elevated at the spastic sites and nonspastic sites. The purpose of this study was to assess the basal coronary artery tone and to evaluate the responsiveness to acetylcholine and ergonovine in patients with variant angina. METHODS: Basal coronary artery tone was assessed by obtaining the percent increase in coronary artery diameter induced by nitroglycerin in 66 patients with variant angina and 26 control subjects. We also compared the basal coronary tone and the constrictive responses to acetylcholine and ergonovine between the 31 patients with variant angina whom spasm was provoked by the low doses of acetylcholine(Ach; intracoronary, 20microg) or ergonovine(Erg; intravenous, 50microg)(Group 1) and the 35 patients provoked by higher doses of acetylcholine(intracoronary, 100microg) or ergonovine(intravenous cumulative dose of 350microg)(Group 2). RESULTS: Patients with variant angina whom spasm was provoked by low doses of acetylcoline and ergonovine, have a more tendency of combine fixed disease(mix disease), multivessel spasm and high disease activity. Basal coronary artery tone at the spastic sites was significantly elevated in the Group 1 in whom spasm was provoked by low doses of acetycholine and ergonovine than that in Group 2(44+/-17 vs 13+/-11%, respectively, p<0.05). Basal coronary artery tone of spasm-related artery, but not nonspasm related artery, at the non spastic site was greater in the Group 1 than that in Group 2 (26+/-14 vs 16+/-10%, respectively, p<0.05). In the patients with variant angina in whom spasm was provoked by higher dose of acetylcholine or ergonovine, basal coronary artery was comparable at the spastic and nonspastic sites and was not different from that in the control subjects. The magnitude of vasoconstrictive responses to acetylcoline and ergonovine, at the nonspastic sites, were also greater in Group 1 than those in Group 2 and the control groups(Ach; 40+/-20 vs 26+/-11. 27+/-12% : Erg ; 37+/-18 vs 12+/-8, 13+/-10%, respectively, p<0.05). CONCLUSION: These findings suggest that elevated basal coronary artery tone of the spastic sites and nonspastic sites of spasm-related artery in patients with variant angina may be related to occurrence of coronary spasm.
Acetylcholine*
;
Arteries
;
Coronary Vessels*
;
Ergonovine*
;
Humans
;
Muscle Spasticity
;
Nitroglycerin
;
Spasm*
8.Coronary Angioplasty in Patients with Multivessel Coronary Artery Disease.
Myeong Ki HONG ; Seung Jung PARK ; Seong Wook PARK ; Jae Joong KIM ; Duk Hyun KANG ; Sang Sig CHEONG ; Yun Ho CHU ; Jae Kwan SONG ; Jong Koo LEE
Korean Circulation Journal 1995;25(4):756-763
BACKGROUND: Indications and applications of percutaneous transluminal coronary angioplasty(PTCA) has been broaden in reccent years. However,we considered many aspects in performing angioplasty in patient with multivessel disease. There were procedural success rate, complication, risk, restenosis and long-term effect. So we evaluated the initial success rate, safety and follow-up results. METHODS: To assess the likelihood of initial success in patients with multivessel coronary artery disease, single or multiple site angioplasy were performed at 449 lesions from 273 patients(Male 202,Female 71, Mean age 60.0+/-9.4 years). To evaluate the restenosis rate of angioplasty in multivessel disease, follow-up coronary angiogram were performed at 164 lesions from 95 patients at average 6months after angioplasty. RESULTS: The extent of coronary artery disease revealed that two vessel disease were 200(73.3%) and triple vessel disease were 73(26.7%). Single vessel angioplasty(SVA) was performed in 180(40.1%) lesions and multivessel angioplasty(MVA) was performed in 269(59.9%) lesions. Procedural success was achieved 377(84.0%) out of total 449 lesions. The proccdural success rate was 81.1% in SVA and 85.9% in MVA. According to major epicardial coronary artery, procedural success rate of left anterior descending artery was 82.0%, left circumflex artery 92.4% and right coronary artery 79.4%. According to angiographic morphology of lesions, procedural success rate of type A was 95.7%, type B 88.9% and type C 56.4%. Complete revascularization was done in 87 patients(31.9%) out of 273 patients. Major cause of failure of angioplasty in multivessel disease was inability to pass the guide wire cross the lesion due to total occlusion. Complications included dissection in 101, acute closure in 7(9.7%), coronary artery perforation in 2, cardiogenic shock in 1 and ventricular fibrillation in 1. Follow-up coronary angiography revealed the restenosis rate was 42.2%. CONCLUSION: Coronary angioplasty in selected patients with multivessel coronary artery disease might be useful and have relatively good immediate and long-term results.
Angioplasty*
;
Arteries
;
Coronary Angiography
;
Coronary Artery Disease*
;
Coronary Vessels*
;
Follow-Up Studies
;
Humans
;
Shock, Cardiogenic
;
Ventricular Fibrillation
9.Plamaz-Schatz Coronary Stenting Accomplished by High Pressure Balloon Dilatation without Anticoagulation.
Myeong Ki HONG ; Sang Sig CHEONG ; Jin Woo KIM ; Sang Kon LEE ; Cheol Whan LEE ; Jae Joong KIM ; Seong Wook PARK ; Seung Jung PARK
Korean Circulation Journal 1996;26(5):935-940
BACKGROUND: The clinical use of intracoronary stents is impeded by the risk of subacute stent thrombosis and complications associated with the anticoagulant regimen. The use of high pressure balloon dilatations and confirmation of adequate stent expansion by intravascular ultrasound provide assurance that anticoagulation therapy can be safely omitted. Therefore, we evaluated the effect of anticoagulation of subacute thrombosis sfter stenting retrospectively on a consecutive series of patients who received palmaz-Schatz coronary stents with high pressure balloon dilatation. METHOD: From March 1995 to August 1995, 62 patients underwent Palmaz-Schatz coronary stent implantation. After deploying stents successfully, high pressure overdilatation of the stents was performed in all patients. According to post-stent anticoagulation, 32 patients received aspirin 200 mg/day, ticlopidine 500 mg/day and warfarin for two months, 30 patients received aspirin and ticlopidine. RESULTS: The clinical or angiographic variables were not significantly different between the two groups. There was no acute or subacute thrombosis in the two groups. The hospital stay after stenting was significantly shorter in the patients without antcoagulation than in patients with anticoagulation. CONCLUSION: The Palmaz-Schatz stent can be safely implanted without anticoagulation provided that stent expansion is daequate by the use high pressure balloon dilatation This technique significantly reduces hospital time and vascular complications and has a low stent thrombosis rate.
Aspirin
;
Dilatation*
;
Humans
;
Length of Stay
;
Retrospective Studies
;
Stents*
;
Thrombosis
;
Ticlopidine
;
Ultrasonography
;
Warfarin
10.Intracoronary Stenting in Patients with Acute Myocardial Infarction.
Myeong Ki HONG ; Seong Wook PARK ; Jae Joong KIM ; Sang Sig CHEONG ; Cheol Whan LEE ; Jin Woo KIM ; Il Soo LEE ; Seung Jung PARK
Korean Circulation Journal 1997;27(1):49-55
BACKGROUND: In elective intervention, the implantation of an intracoronary stent is an established treatment modality to reduce restenosis in comparison with balloon angioplasty. However, stenting was empirically thought to be contraindicated for acute myocardial infarction because of the propensity for thrombosis, althought the percutaneous transluminal coronary balloon angioplasty(PTCA) on infarct-related artery is associated with a high incidence of restenosis. To knowlege, there is no report comparing the longterm efficacy of coronary stenting with PTCA in patients with acute myocardial infarction. Accordingly, we investigated the effect of stent implantation on restenosis of infarct-related artery in acute myocardial infarction, comparing with conventional balloon angioplasty. METHOD: From January 1994 to December 1995, 97 patients (stenting in 45 patients : PTCA in 52 patients) underwent intracoronary stenting or PTCA on infarct-related artery successfully at 7-10 days after onset of infarction. The coronary stents were Palmaz-Schatz stent in 35 patients and Cordis stent in 10 patients. Follow-up coronary angiography was performed in all patients 6 months later after intervention. RESULTS: No death, emergency coronary artery bypass surgery or reinfarction occurred during hospitalization in 97 patients. In 45 patients with stent implantation, no stent thrombosisoccurred. The 6-months angiographic restenosis rate was 13 percent in patients assigne to stent implantation and 52 percent in patients assigned to PTCA(p<0.05). CONCLUSION: We conclude that the intracoronary stent implantation on infarct-related artery at 7-10 days after acute myocardial infarction is safe, feasible and significantly reduces the restenosis rate.
Angioplasty, Balloon
;
Arteries
;
Coronary Angiography
;
Coronary Artery Bypass
;
Emergencies
;
Follow-Up Studies
;
Hospitalization
;
Humans
;
Incidence
;
Infarction
;
Myocardial Infarction*
;
Stents*
;
Thrombosis