1.The level of residual monomer in injection molded denture base materials.
Hyeok Jae LEE ; Chang Whe KIM ; Yung Soo KIM
The Journal of Korean Academy of Prosthodontics 2003;41(3):360-368
STATEMENT OF PROBLEM: The residual monomer of denture base materials causes hypersensitivity on oral mucosa and intereferes with the mechanical properties of the cured resin. The amount of residual monomer is influenced by materials, curing cycle, processing method, and etc. PURPOSE: The aim of this study was to investigate the residual methyl methacrylate(MMA) content of injection molded denture base polymer, and to compare this with the self-cured resin and the conventional compression molded heat-cured resin. MATERIALS AND METHODS: Disc shaped test specimens (50mm in diameter and 3mm thick) were prepared in a conventional flasking technique with gypsum molding. One autopolymerized denture base resins (Vertex SC. Dentimex. Netherlands) and two heat-cured denture base resins (Vertex RS. Dentimex. Netherlands, Ivocap. Ivoclar Vivadent, USA) were used. The three types of specimens were processed according to the manufacturer's instruction. After polymerization, all specimens were stored in the dark at room emperature for 7 days. There were 10 specimens in each of the test groups. 3-mm twist drills were used to obtain the resin samples and 650mg of the drilled sample were collected for each estimation. Gas chromatography (Agillent 6890 Plus Gas Chromatograph, Agillent Co, USA) was used to determine the residual MMA content of 10 test specimens of each three types of polymer. RESULTS: The residual monomer content of injection molded denture base resins was 1.057+/- 0.141%. The residual monomer content of injection molded denture base resins was higher than that of compression molded heat cured resin (0.867+/-0.169%). However, there was no statistical significant difference between two groups (p > 0.01). The level of residual monomer in self cured resin(3.675+/-0.791) was higher than those of injection molded and compression molded heat cured resins (p<0.01). CONCLUSION: With respect to ISO specification pass/fail test (2.2% mass fraction) of residual monomer, injection molding technique(1.057+/-0.141%) is a clinicaly useful and safe technique in terms of residual monomer.
Calcium Sulfate
;
Chromatography, Gas
;
Denture Bases*
;
Dentures*
;
Fungi*
;
Hot Temperature
;
Hypersensitivity
;
Mouth Mucosa
;
Netherlands
;
Polymerization
;
Polymers
2.Quantification of Nucleolar Organizer Regions in Skin Tumors.
Sung Yul LEE ; Chong Hyeok KIM ; Chil Hwan OH
Annals of Dermatology 1994;6(2):140-145
BACKGROUND: Nucleolar organizer regions (NORs) have recently attracted much attention because of claims that their frequency within nuclei is significantly higher in malignant cells than in normal, reactive, or benign neoplastic cells. OBJECTIVE: The purpose of this paper is to analyze a method allowing selection of the best morphometric criterion for quantifying AgNOR proteins under conventional observation conditions by light microscopy. METHOD: We tried to investigate the various parameters including NORs counting in cutaneous tumors using image analysis system. RESULTS: There were significant differences in mean nucleus area per a AgNOR, nucleus area between the benign and potentially malignant group. But the conventional counting of AgNORs is not able to differentiate between the two groups. We could discriminate squamous cell carcinoma from Bowen's disease using parameters of mean ratio of AgNORs area per nucleus area, mean ratio of greatest AgNORs area per nucleus area, coefficient of variation (C V) of nucleus area, and mean area of largest AgNORs. In squamous cell carcinoma and keratoacanthoma, C V of nucleus area has shown a significant difference. CONCLUSION: Study of AgNORs using image analysis system is a useful tool for the diagnosis of cutaneous tumors.
Bowen's Disease
;
Carcinoma, Squamous Cell
;
Diagnosis
;
Keratoacanthoma
;
Methods
;
Microscopy
;
Nucleolus Organizer Region*
;
Skin*
3.A case of Ki-1 positive large-cell lymphoma.
Chong Hyeok KIM ; Seong Yeol LEE ; Chil Hwan OH
Korean Journal of Dermatology 1993;31(3):444-448
In 1985, Stein et al, indentified an anaplastic large-cell malignant lymphoma that was distinctive because of the diffuse dermal infiltration of pleomorphic large lymphocytes, sinus growth pattern, and reactivity with the monoclonal antibody Ki-1(CD30). The clinical feature; distinguishing anaplastic large-cell Ki-1 lymphoma include a young median age, frequent peripheral adenopathy with sparing of the mediastinum, and extranodal disease with skin the most common sitc of involvement. We report a case of Ki-1 postive large-cell lymphoma in a 74-year-old male patient who presented with multiple ulcerated nodules on the right shin area.
Aged
;
Humans
;
Lymphocytes
;
Lymphoma*
;
Lymphoma, Large-Cell, Anaplastic
;
Male
;
Mediastinum
;
Skin
;
Ulcer
4.MR Imaging of Tibial Plateau Fractures: Evaluation of Fracture Types and Associated Soft Tissue Injuries.
Geon LEE ; Chan HEO ; Yong Jo KIM ; Hyeok Po KWON ; Jung Hyeok KWON ; Won Ho KIM ; Yeong Hwan LEE
Journal of the Korean Radiological Society 1997;36(5):867-872
PURPOSE: To evaluate the usefulness of magnetic resonance imaging (MRI) for assessing fracture types and soft tissue injuries associated with tibial plateau fractures. MATERIALS AND METHODS: MRI was performed in 38 patients with tibial plateau fractures, each of which was classified according to the Schatzker system. We evaluated MR images and assessed the prevalence of each fracture type and accompanying soft tissue injuries. We also assessed whether ligamentous injury correlated with the extent of articular depression, splitting, and comminution. In 24 patients, diagnosis was based on MRI and operative or arthroscopic findings, and in 14 patients, on MRI alone. RESULTS: The totals of fracture types I, II, III, IV, V and VI were 4 (11 %), 15 (39 %), 6 (16 %), 4 (11 %), 4 (11%), and 5 cases (13 %), respectively. In 30 cases (79 %), there were associated ligamentous or meniscal injuries. Medial collateral ligaments and lateral menisci were injured in 17 (45 %) and 14 cases (37 %), respectively. Type II and IV fracture patterns were associated with soft tissue injuries in 14 of 15 cases (93 %) and 4 of 4 cases(100 %), respectively. As the extent of articular depression increased and the extent of bony comminution decreased, there was an increased prevalence of accompanying ligamentous injuries. CONCLUSION: In tibial plateau fractures, MR imaging is a useful diagnostic modality for the evaluation of both fracture type and accompanying ligamentous or meniscal injuries.
Collateral Ligaments
;
Depression
;
Diagnosis
;
Humans
;
Ligaments
;
Magnetic Resonance Imaging*
;
Menisci, Tibial
;
Prevalence
;
Soft Tissue Injuries*
5.Facet Joint Injuries in Acute Cervical Spine Trauma: Evaluation with CT and MRI.
Jeon Ju HA ; Dong Hyun KIM ; Jeong Hwa LEE ; Keon LEE ; Hyeok Po KWON ; Jung Hyeok KWON ; Seong Mun YUN
Journal of the Korean Radiological Society 1999;40(5):957-963
PURPOSE: To evaluate injury patterns of facet joints and associated soft tissue injuries in patients withacute traumatic cervical facet joint injuries. MATERIALS AND METHODS: From among patients with cervical spinetrauma, 27 with facet joint injuries, as seen on CT and MRI, were chosen for this study. CT scans were analyzedwith regard to the location of facet joint injury, the presence or absence of facet dislocation or fracture, andother associated fractures. MR images were analyzed with regard to ligament injury, intervertebral disc injury,intervertebral disc herniation, and spinal cord injury. RESULTS: The most common location of facet joint injurywas C6-7 level(n=10), followed by C5-6(n=8). Among these 27 patients with facet joint injuries, 12(44%) hadbilateral injuries and 15(56%) unilateral injuries. Facet fractures were present in 17 cases(63%) and the fractureof inferior facet was more frequent than superi-or. Patterns of fracture were vertical, transverse, or comminuted,but vertical fracture was the most common. Various degrees of dislocation were observed in patients with facetfractures. Fractures other than facet includ-ed pillar(n=11), lamina(n=6), transverse process(n=14), body(n=13),and spinous process(n=3). On MR im-ages, anterior longitudinal ligament injury was found in 8 patients(30%),posterior longitudinal ligament injury in 4(15%), and interspinous ligament injury in 20(74%). Twelvepatients(44%) had spinal cord injuries includ-ing edema(n=8) and hemorrhage(n=4). Among patients with discabnormalities, 11(41%) had intervertebral disc injuries, and traumatic disc herniations were found in nine. CONCLUSION: Traumatic cervical facet joint injuries were manifested as various patterns and frequentlyassoci-ated with other fractures or soft tissue injuries. Analysis of CT and MR findings of these injury patternshelped formulate a therapeutic plan and determine of prognosis.
Dislocations
;
Humans
;
Intervertebral Disc
;
Ligaments
;
Longitudinal Ligaments
;
Magnetic Resonance Imaging*
;
Prognosis
;
Soft Tissue Injuries
;
Spinal Cord Injuries
;
Spine*
;
Tomography, X-Ray Computed
;
Zygapophyseal Joint*
6.Statitical Techniques Reported in Korean Dermatology Journals During 1990-1994.
Sung Yul LEE ; Jong Suk LEE ; Jae Young HWANG ; Chong Hyeok KIM
Annals of Dermatology 1996;8(4):243-246
BACKGROUND: Effective evaluation of an article's scientific merit requires familiarity with the methodology described, especially when quantitative techniques, such as statistical procedures, are invoked to clarify research findings or to summarize data. OBJECTIVE: The purpose of this study was to describe the frequency with which various statistical concepts were reported in journals important to dermatology. From these results, dermatologists can identify the major statistical skills needed to critically evaluate their literature. METHODS: All 376 original articles of the Korean Journal of Dermatology(KJD) and the Annals of Dermatology(KAD) during 1990-1994 were chosen for review. Each article was re-viewed to determine the statistical content. RESULTS: The two most commonly used statistical techniques in the two journals were mean and standard deviation. The t-test was the next most frequently used statistical technique in the reviewed journals, followed by non-parametric, chi-square test, orphan p, ANOVA, and correlation/regression. CONCLUSION: These results indicate the need for wider education about the use of descriptive and basic comparative statistics. It is impossible to evaluate the dermatological literature critically without these skills.
Child
;
Child, Orphaned
;
Dermatology*
;
Education
;
Humans
;
Recognition (Psychology)
7.Acanthocytosis in a Patient with Chorea-acanthocytosis.
Laboratory Medicine Online 2012;2(3):179-180
No abstract available.
Abetalipoproteinemia
;
Humans
;
Neuroacanthocytosis
8.Acanthocytosis in a Patient with Chorea-acanthocytosis.
Laboratory Medicine Online 2012;2(3):179-180
No abstract available.
Abetalipoproteinemia
;
Humans
;
Neuroacanthocytosis
9.The difference of the relaxation index, angular velocity, and angular acceleration of pendulum test in elbow joint according to muscle tone.
Hyeok SON ; Joong Son CHON ; Sook Ja LEE ; Yang Soo LEE ; Kyung Deog KIM
Journal of the Korean Academy of Rehabilitation Medicine 1993;17(2):202-207
No abstract available.
Acceleration*
;
Elbow Joint*
;
Elbow*
;
Relaxation*