1.A Study on Periphral T Cell Subsets in Asymptomatic HBsAg Carriers and Children with Chronic Hepatitis B and Hepatitis B vaccine Inoculated Infants.
Journal of the Korean Pediatric Society 1989;32(9):1248-1258
No abstract available.
Child*
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Hepatitis B Surface Antigens*
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Hepatitis B Vaccines*
;
Hepatitis B*
;
Hepatitis B, Chronic*
;
Hepatitis*
;
Hepatitis, Chronic*
;
Humans
;
Infant*
;
T-Lymphocyte Subsets*
2.A study on fracture strength and color by the design of metal coping in ceramo metal crown.
Myung Ho LEE ; Young Chan JEON
The Journal of Korean Academy of Prosthodontics 1992;30(1):103-124
No abstract available.
Crowns*
3.THREE-DIMENSIONAL COMPARISON OF FRAMEWORK DISPLACEMENTS JOINED BY VARIOUS CONNECTION TECHNIQUES.
Jang Seop LIM ; Young Chan JEON ; Chang Mo JEONG
The Journal of Korean Academy of Prosthodontics 1999;37(3):358-374
This study measured the relative displacements of the five-unit fixed partial dentures as cast with the same fixed partial dentures sectioned and assembled by investment-soldering, soldering stand-soldering, and cast-joining techniques. A total of fifteen specimens using a type IV gold alloy wee one-piece cast as control and then sectioned and assembled five test specimens for each method were prepared. A computerized three dimensional coordinate measuring machine and specially designed cylinder for this study were used. Displacement was defined by six displacement variables for the each of cylinders incorporated in each casting: three component displacements ( Lx, Ly, and Lz) and rotational displacements( thetax, thetay, thetaz). The global displacement was computed using the mathematical formula R= Global displacement ={{{{rm SQRT { (x'-x)^2 +(y'-y)^2 + (z'-z)^2} }} }} Under the conditions of this study, the following conclusions were drawn: 1. The investment-soldering group showed the largest mean value of final global displacements, followed by stand-soldering group, cast-joining group and one-piece cast group. However, between the mean values of final global displacement for the cast-joining group and one-piece cast group, there was no significant difference. 2. For investment-soldering and stand-soldering groups, the greater global displacements were recorded in soldering phase than in indexing or investing phase. 3. For one-piece cast group, the displacements occured mostly in the casting phase. And for castjoining group, there was no significant difference in global displacements among the fabrication procedures. 4. Intercentroidal distance decreased in framework-pattering, solder-indexing, solder-standing, and soldering phases, but increased in investment block-investing and casting phases. 5. Specially designed cylinder for touch-trigger type coordinate measuring machine was validated.
Abstracting and Indexing as Topic
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Alloys
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Denture, Partial, Fixed
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Investments
;
Methods
4.A MEASUREMENT OF DISPLACEMENTS OF CAST FRAMEWORK BY TORCH SOLDERING AND ELECTRIC SOLDERING TECHNIQUES.
Sang Won JEON ; Jang Seop LIM ; Chang Mo JEONG ; Young Chan JEON
The Journal of Korean Academy of Prosthodontics 1999;37(6):791-799
The purpose of this study was to investigate the displacements of cast framework by torch soldering and electric soldering techniques. Specimen had two cylinders and connecting bar that had sectioned with 0.3mm gap at mid point. 10 of total specimens were divided into two groups. In torch soldered group, soldering investment block was made and conventional torch soldering procedure was carried out. In electric soldered group, electric soldering was carried out on the master cast without soldering investment block by using electric soldering machine(Dentapunkt DP 7, Kulzer, Germany). After soldering procedure, three dimensional coordinates of two centroids of each cylinder were measured by three dimensional coordinate measuring machine. The intercentroidal displacement and global displacement were calculated and then, these values were compared and evaluated. The results were obtained as follows: 1. Intercentroidal distances of specimens decreased after both soldering procedures, and the decrease in intercentroidal distance was greater for torch soldered group than for electric soldered group 2. Global displacements of torch soldered group were greater than those of electric soldered group
Investments
5.Molecular Epidemiological Characteristics of Drug-resistant Mycobacterium tuberculosis by Random Amplified Polymorphic DNA Genotyping.
Jong Chan JEON ; Dong Seok JEON ; Jae Ryong KIM
Korean Journal of Clinical Pathology 2001;21(4):274-281
BACKGROUND: In spite of appropriate therapy and control for tuberculosis, the prevalence of tuberculosis is still frequent in Korea. Emerging infection and rapid detection of multidrug-resistant Mycobacterium tuberculosis (MDR-TB) are major interests in microbiologic laboratories. In this study, we evaluated the usefulness of random amplified polymorphic DNA (RAPD) genotyping for molecular epidemiological characteristics of MDR-TB. METHODS: We analyzed 64 clinical strains of M. tuberculosis including 35 strains which showed resistance to one or more antimycobacterial drugs and M. tuberculosis H37Rv (ATCC 27294), as a drug-sensitive control strain. RAPD genotyping analysis was carried out under eight reaction conditions and using ten random primers (A-1245, AP-50, B-1245, DKU-44, DKU-49, Leg-1, INS-2, IS-986-FP, PF-15 and MBR). RESULTS: RAPD patterns using six primers (IS-986-FP, DKU-44, DKU-49, INS-2, B-1245, and AP-50) showed marked polymorphisms that were easier to discriminate than those with other primers. RAPD patterns represented various polymorphisms among 64 strains. However, RAPD could not discriminate MDR-TB strains from drug-sensitive ones. CONCLUSIONS: RAPD genotyping is assumed a preferable technique for discrimination among clinical strains of M. tuberculosis but not for specifying MDR-TB strains.
Discrimination (Psychology)
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DNA*
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Korea
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Mycobacterium tuberculosis*
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Mycobacterium*
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Prevalence
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Tuberculosis
6.Alteration of Interleukin-6 Levels in Brain Tissue and Serum of Rats after an Experimental Brain Contusion.
Byeong Min JEON ; Yang Weon KIM ; Byung Chan JEON
Journal of the Korean Society of Emergency Medicine 2003;14(1):17-22
PURPOSE: Cerebral contusion is often associated with delayed edema, ischemia, demyelination, and secondary impairment in the neurological function. Early prediction of the outcome for patients with diverse critical illnesses has long been a concern of intensive care unit physicians. Recently, the systemic release of host-derived inflammatory mediators has been used for prognosis assessment in patients with multiple infections, burn injury, and systemic infection. Experimental investigations have revealed the importance of free radicals and calcium currents in cellular damage. Also experimental injuries have caused an early production of cytokines. This study was undertaken to analyze the production of interleukin-6 in the brain and in plasma following a brain contusion. METHODS: Sixty male Sprague-Dawley (SD) rats, each weighing 300-350 g were used in an experimental group following brain contusion, and 18 SD rats were used as a control group following a sham operation. Intracerebral IL-6 and plasma IL-6 were measured by using the ELISA method with a rat IL-6 kit at 3, 6, 24, 48, and 72 hours after the brain contusion. After contusion, the brains were fixed by perfusion via the carotid artery with 40% formaldehyde, glacial acetic acid, and 100% ethanol (1:1:8) at a flow rate of 25 ml/min and stained with hematoxylin and eosin for histologic examination. RESULTS: Brain IL-6 levels increased to reach a maximum of 160.23 pg/ml, at 6 hour after brain trauma. Plasma IL-6 levels increased to 70.02 pg/ml at 3 hour following brain contusion. CONCLUSION: The elevated brain IL-6 level in the injured rat does not seem to reflect a systemic inflammation. Although plasma IL-6 is detected in the sham-operated and the traumatized rats, the levels are too low to account for the increase observed in the brain cortex. This finding shows that the increase in brain IL-6 is related to the dynamics of brain contusion.
Acetic Acid
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Animals
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Brain Injuries*
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Brain*
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Burns
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Calcium
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Carotid Arteries
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Contusions
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Critical Illness
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Cytokines
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Demyelinating Diseases
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Edema
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Enzyme-Linked Immunosorbent Assay
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Eosine Yellowish-(YS)
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Ethanol
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Formaldehyde
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Free Radicals
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Hematoxylin
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Humans
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Inflammation
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Intensive Care Units
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Interleukin-6*
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Ischemia
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Male
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Perfusion
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Plasma
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Prognosis
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Rats*
;
Rats, Sprague-Dawley
7.A study of precise fit of the CAM zirconia all-ceramic framework.
Mi Hyeon JEON ; Young Chan JEON ; Chang Mo JEONG ; Jang Seop LIM ; Hee Chan JEONG
The Journal of Korean Academy of Prosthodontics 2005;43(5):611-621
STATE OF PROBLEM: Zirconia all-ceramic restoration fabricated with CAM system is on an increasing trend in dentistry. However, evaluation of the marginal and internal fits of zirconia bridge seldomly have been reported. PURPOSE: This study was to evaluate the fit of margin and internal surface in posterior 3-unit zirconia bridge framework fabricated with CAM system(DeguDent, Germany). MATERIAL AND METHOD: Preparations of secondary premolar and secondary molar on artificial resin model were performed for fabrication of 3-unit posterior bridge framework. Fits of 5 zirconia bridge framework were compared with 5 precious ceramo-metal alloy framework(V-GnathosPlus, Metalor, Switzerland), and prepared margins were designed to chamfer and shoulder finishing line. Each framework was cemented to epoxy resin model with reinforced glass ionomer(FujiCEM, GC Co., Japan), embedded in acrylic resin and sectioned in two planes, mesiodistal and buccolingual. Samples were divided into six pieces by sectioning and had two pieces of each surface(i.e. mesial, distal, buccal and lingual surface) per abutment, so there were eight measuring points in each abutment. External gap was measured at the margin and internal gaps were measured at the margin, axial and occlusal surface. Gaps were observed under the measuring microscope(Compact measuring microscope STM5; Olympus, Japan) at a magnification of * 100. T-test were used to determine the statistic significance of the different gaps between zirconia and metal framework. RESULTS AND CONCLUSION: 1. External and internal marginal gaps of zirconia and metal framework were in clinically acceptable range. External marginal gaps were not different significantly between zirconia(81.9 micrometer) and metal(81.3 micrometer) framework and internal marginal gaps of zirconia(44.6 micrometer) were smaller than those of metal framework(58.6 micrometer). 2. Internal axial gaps of zirconia framework(96.7 micrometer) were larger than those of metal framework(78.1 micrometer) significantly and adversely, internal occlusal gaps of zirconia framework(89.4 micrometer) were smaller than those of metal framework(104.9 micrometer) significantly. 3. There were no significant differences in external and internal marginal gaps between chamfer and shoulder finish line when zirconia frameworks were fabricated.
Alloys
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Bicuspid
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Dentistry
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Glass
;
Molar
;
Shoulder
8.Closed Reduction and Percutaneous K-Wire Fixation of Bony Mallet Finger Using an 18 Gauge Needle.
Ho Seung JEON ; Seung Ju JEON ; Chan Sam MOON ; Sung Hoon JUNG ; Sung Kwang JEON
Journal of the Korean Society for Surgery of the Hand 2010;15(2):77-82
PURPOSE: To evaluate the clinical results of the treatment of the percutaneous Kirschner wire fixation of bony mallet finger using an 18 gauge needle. MATERIALS AND METHODS: From September 2002 to September 2009, we performed closed reduction using an 18 gauge needle and percutaneous fixation with Kirschner wire for 15 cases of bony mallet finger and followed up at least 1 year. The fractures were classified by the Wehbe and Schneider's method. Indications of operative treatment were fractures involving more than 30% of articular surface, fracture fragments displaced more than 3 mm, or subluxation of the distal interphalangeal joint. The results were evaluated by the Crawford criteria. RESULTS: All the fractures united, with an average healing time of 5.3 weeks(4-6 weeks). According to Crawford criteria, 10 cases were excellent, 5 cases were fair at a mean follow-up of 13 months. There were no pin tract infections and migrations of the pin. CONCLUSION: Percutaneous Kirschner wire fixation of mallet finger using an 18 gauge needle is an easy technique which can achieve anatomical reduction and diminish operation-related complications.
Fingers
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Follow-Up Studies
;
Joints
;
Needles
9.MARGINAL DISCREPANCY AND RETENTION FORCE OF CONICAL TELESCOPE OUTER CROWN WITH CO-CR-TI ALLOY.
Hi Chan JUNG ; Chang Mo JEONG ; Young Chan JEON ; Jang Seop LIM
The Journal of Korean Academy of Prosthodontics 2000;38(2):214-225
The purpose of this study was to investigate the effects of investing conditions on the marginal discrepancy of conical telescope outer crown with Co-Cr-Ti alloy(Dentitan) and to compare the marginal discrepancy and the retention force of outer crowns using different pattern materials (plastic foil, casting wax, pattern resin). To evaluate the effects of investing conditions on the marginal discrepancy, patterns with plastic foil were invested under three different liquid/powder ratio conditions using phosphate bonded investment (Univest-nonprecious): standard, 10% decreased and 10% increased. At each liquid/powder ratio condition, metal ring was lined with single or double layers of ceramic ring liner. The marginal discrepancy of outer crown at different investing conditions was measured by x 100 compact measuring microscope(STM5, Olympus, Japan). For measurement of the marginal discrepancy and the retention force of outer crown using different pattern materials, the investing condition of 10% decreased liquid/powder ratio and double layers of ring liner was selected because this investing condition resulted in the best fit of outer crown. Marginal discrepancy was measured in the same way above and retention force on universal testing machine. Under the conditions of this study, the following conclusions were drawn: 1. The thickness of ring liner had more influence on the marginal discrepancy of outer crown than the liquid/powder ratio, and the acceptable marginal fitness could not be expected at the investing condition directed by investment manufacturer. 2. There were no differences in the marginal discrepancy of outer crown among three different pattern materials 00.05). 3. Casting wax showed the greatest retention force(1640g) of outer crown, followed by pattern resin(1110g), plastic foil(820g). However, there was no significant difference between plastic foil and pattern resin(p>0.05). 4. Plastic foil showed the least variation in marginal discrepancy and retention force.
Alloys*
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Ceramics
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Crowns*
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Investments
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Plastics
;
Telescopes*
10.Fracture strength of zirconia monolithic crowns and metal-ceramic crowns after cyclic loading and thermocycling.
Sang Min LEE ; Hee Chan JEONG ; Young Chan JEON
The Journal of Korean Academy of Prosthodontics 2007;45(1):12-20
PURPOSE: The purpose of this study was to compare the fracture strength of the zirconia monolithic all-ceramic crowns according to the thickness (0.5mm, 0.8mm, 1.1mm) and metal-ceramic crowns (1.0mm, 1.5mm). MATERIAL AND METHOD: Twelve crowns for each of 3 zirconia crown groups were fabricated using CAD/CAM system (Kavo, Germany) and twelve crowns for each of 2 metal-ceramic crown groups were made by the conventional method. All crowns were luted to the metal dies using resin cement. Half of the specimens were exposed to thermocycling (5-55degrees C, 1 Hz) and cyclic loading (300,000 cycles, 50N). Subsequently, all crowns were mounted on the testing jig in a universal testing machine. The load was directed at the center of crown with perpendicular to the long axis of each specimen until catastrophic failure occurred. Analysis of variance and Tukey multiple comparison test (P<.05) were used for statistical analysis of all groups, and paired t-test (P<.05) was followed for statistical comparison between each groups'fracture load before and after cyclic loading. RESULTS: 1. The fracture strength of the zirconia monolithic crowns and the metal-ceramic crown increased as thickness increased (P<.05). 2. The cyclic loading and thermocycling significantly decreased the fracture strength of the zirconia monolithic crowns (P<.05). 3. The standard deviation of fracture strength of the zirconia monolithic crowns was very low. CONCLUSION: The fracture strength of the zirconia monolithic crowns for the posterior area tends to be higher with thickness increased and 0.8mm or over in thickness is recommended to have similar or over the fracture strength of metal-ceramic crowns.
Axis, Cervical Vertebra
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Crowns*
;
Resin Cements