1.Stress analysis of supporting tissues and implants according to implant fixture shapes and implant-abutment connections.
Sang Un HAN ; Ha Ok PARK ; Hong So YANG
The Journal of Korean Academy of Prosthodontics 2004;42(2):226-237
PURPOSE: Four finite element models were constructed in the mandible having a single implant fixture connected to the first premolar-shaped superstructure, in order to evaluate how the shape of the fixture and the implant-abutment connection would influence the stress level of the supporting tissues, fixtures, and prosthethic components. MATERIAL AND METHODS: The superstructures were constructed using UCLA type abutment, ADA type III gold alloy was used to fabricate a crown and then connected to the fixture with an abutment screw. The models BRA, END, FRI, ITI were constructed from the mandible implanted with Branemark, Endopore, Frialit-2, I.T.I systems respectively. In each model, 150 N of vertical load was placed on the central pit of an occlusal plane and 150 N of 40.oblique load was placed on the buccal cusp. The displacement and stress distribution in the supporting tissues and the other components were analysed using a 2-dimensional finite element analysis. The maximum stress in each reference area was compared. RESULTS: 1. Under 40.oblique loading, the maximum stress was larger in the implant, superstructure and supporting tissue, compared to the stress pattern under vertical loading. 2. In the implant, prosthesis and supporting tissue, the maximum stress was smaller with the internal connection type (FRI) and the morse taper type (ITI) when compared to that of the external connection type (BRA and END). 3. In the superstructure and implant/abutment interface, the maximum stress was smaller with the internal connection type (FRI) and the morse taper type (ITI) when compared to that of the external connection type (BRA and END). 4. In the implant fixture, the maximum stress was smaller with the internal connection type (FRI) and the morse taper type (ITI) when compared to that of the external connection type (BRA and END). 5. The stress was more evenly distributed in the bone/implant interface through the FRI of trapezoidal step design. Especially Under 40.oblique loading, The maximum stress was smallest in the bone/implant interface. 6. In the implant and superstructure and supporting tissue, the maximum stress occured at the crown loading point through the ITI. CONCLUSION: The stress distribution of the supporting tissue was affected by shape of a fixture and implant-abutment connection. The magnitude of maximum stress was reduced with the internal connection type (FRI) and the morse taper type (ITI) in the implant, prosthesis and supporting tissue. Trapezoidal step design of FRI showed evenly distributed the stress at the bone/implant interface.
Alloys
;
Crowns
;
Dental Occlusion
;
Finite Element Analysis
;
Mandible
;
Prostheses and Implants
2.Use of Tandem Mass Spectrometry for Newborn Screening of 6 Lysosomal Storage Disorders in a Korean Population.
Minje HAN ; Sun Hee JUN ; Sang Hoon SONG ; Kyoung Un PARK ; Jin Q KIM ; Junghan SONG
The Korean Journal of Laboratory Medicine 2011;31(4):250-256
BACKGROUND: We evaluated the performance of multiplex tandem mass spectrometry (MS/MS) in newborn screening for detection of 6 lysosomal storage disorders (LSDs), namely, Niemann-Pick A/B, Krabbe, Gaucher, Fabry, and Pompe diseases and Hurler syndrome. METHODS: We revised the conditions and procedures of multiplex enzyme assay for the MS/MS analysis and determined the precision of our enzyme assay and the effects of sample amounts and incubation time on the results. We also measured the degree of correlation between the enzyme activities in the dried blood spots (DBSs) and those in the leukocytes. DBSs of 211 normal newborns and 13 newborns with various LSDs were analyzed using our revised methods. RESULTS: The intra- and inter-assay precisions were 2.9-18.7% and 8.1-18.1%, respectively. The amount of product obtained was proportional to the DBS eluate volume, but a slight flattening was observed in the product vs. sample volume curve at higher sample volumes. For each enzyme assay, the amount of product obtained increased linearly with the incubation period (range, 0-24 hr). Passing and Bablok regression analysis revealed that the enzyme activities in the DBSs and those in the leukocytes were favorably correlated. The enzyme activities measured in the DBSs were consistently lower in patients with LSDs than in normal newborns. CONCLUSIONS: The performance of our revised techniques for MS/MS detection and enzyme assays was of the generally acceptable standard. To our knowledge, this is the first report on the use of MS/MS for newborn screening of LSDs in an Asian population.
Dried Blood Spot Testing
;
Enzyme Assays
;
Enzymes/blood
;
Humans
;
Infant, Newborn
;
Leukocytes/enzymology
;
Lysosomal Storage Diseases/*diagnosis
;
Republic of Korea
;
Tandem Mass Spectrometry/*methods
;
Time Factors
3.Facial paralysis after spine surgery : A case report.
Go Un ROH ; Dong Woo HAN ; Jong Seok LEE ; Sang Beom NAM ; Sungwon NA
Anesthesia and Pain Medicine 2009;4(2):187-189
diopathic facial nerve paralysis after surgery is not common but has clinical significance. We report a case of facial nerve paralysis in the immediate postanesthetic period after cervical spine surgery. A 41-year-old man with cervical herniated disc was scheduled for cervical laminectomy. After uneventful surgery, he suffered from left facial numbness and weakness. Imaging study and audiogram couldn't reveal any anatomic abnormality except Thornwaldt cyst. Conservative treatment with steroids and antivirals resolved his symptoms until 16th day after surgery.
Adult
;
Anesthesia, General
;
Antiviral Agents
;
Facial Nerve
;
Facial Paralysis
;
Humans
;
Hypesthesia
;
Intervertebral Disc Displacement
;
Laminectomy
;
Paralysis
;
Spine
;
Steroids
4.Endoscopic Appearances of Metastatic or Invasive Cancers to the Colorectum.
Han Chu LEE ; Hwoon Yong JUNG ; Sang Un CHOI ; Hung Chae JUNG ; Yong Bum YOON ; In Sung SONG ; Kyoon Wan CHOI ; Chung Yong KIM
Korean Journal of Gastrointestinal Endoscopy 1991;11(1):105-108
It is not uncommon that an endoscopist should differentiate metastatic or invasive cancer to the colorectum from primary colorectal cancer with its endoscopic appearances. This study reviewed the endoscopic appearances of 7 patients who were proved to have metastatic or invasive cancers to the colorectum, both clinically and pathologically. The primary cancers were uterine cervix cancers in 3 patients, advanced gastric cancers in two, and prostatic cancer in one. The endoseopic appearances of metastatic or invasive cancer showed several characteristic features with regard to those of primary colorectal cancer, as follows. 1) Multiplicity of lesions 2) Nodular lesion with unaffected mucosa or with mild degree of erosions 3) Concentric defarmities with conical extremities and the absence of shelving margins 4) Inflammatroy lesions with mucosal hyperemia, erosion, ulceration, and bleeding, but without definite mass formation.
Cervix Uteri
;
Colorectal Neoplasms
;
Extremities
;
Female
;
Hemorrhage
;
Humans
;
Hyperemia
;
Mucous Membrane
;
Prostatic Neoplasms
;
Stomach Neoplasms
;
Ulcer
5.Performance Evaluation of the ADAMS A1c HA-8180 Analyzer for HbA1c.
Qute CHOI ; Minje HAN ; Ho Eun CHANG ; Sang Hoon SONG ; Kyoung Un PARK ; Junghan SONG
Journal of Laboratory Medicine and Quality Assurance 2012;34(1):25-30
BACKGROUND: Hemoglobin A1c (HbA1c) levels are widely used to monitor glycemic control in diabetes mellitus patients, and various methods are used for determining HbA1c levels. The ADAMS A1c HA-8180 (Arkray, Inc., Japan) is a fully automated HbA1c analyzer based on high-performance liquid chromatography (HPLC). METHODS: The analytical performance of the ADAMS A1c HA-8180 analyzer was evaluated on the basis of its precision, linearity, correlation with the Variant II Turbo (Bio-Rad Laboratories, USA), and agreement with the National Glycohemoglobin Standardization Program (NGSP) targets. All evaluations were performed according to Clinical and Laboratory Standard Institute (CLSI) guidelines EP05, EP06, and EP09. RESULTS: Coefficients of variation (CVs) for total precision at low and high levels were 0.99% and 1.16%, respectively. The linearity was excellent with R2 = 0.99 in the range of 4.98-15.10%. Its analytical performance was well correlated with that of Variant II Turbo (r = 0.9987). The 95% confidence interval of bias between the NGSP target and the levels measured using the ADAMS A1c HA-8180 was -0.402-0.225. CONCLUSIONS: The ADAMS A1c HA-8180 showed excellent precision, linearity, correlation with Variant II Turbo, and agreement with the NGSP target. Therefore, its analytical performance is satisfactory for diagnosis and treatment monitoring of diabetes.
Bias (Epidemiology)
;
Chromatography, Liquid
;
Diabetes Mellitus
;
Hemoglobins
;
Humans
;
Organothiophosphorus Compounds
6.Assessment of Regional Wall Motion of the Left Ventricle in Children with Congenital Heart Disease.
Chang Hee HAN ; Jun Ho HUH ; Un Seok NHO ; Byung Ho CHOI ; Myung Chul HYUN ; Sang Bum LEE
Journal of the Korean Pediatric Society 1999;42(6):807-816
PURPOSE: To assess wall motion of the left ventricle in the various forms of congenital heart disease and to select appropriate methods by which to gauge left ventricular wall motion. METHODS: We evaluated left ventricular function, including volume, global ejection fraction, and regional wall motion(Centerline method, Local Ejection Fraction, Curved Perimeter method and Radial method). The evaluation was done on review mode of 30-degree elongated right anterior oblique projection of left ventriculogram by using cardiac analysis program of the DXC Hiline Digital System(GER, USA) in 53 pediatric patients undergoing diagnostic(or therapeutic) cardiac catheterization from June 1995 to July 1996 at Kyung-pook National University Hospital. RESULTS: Cardiac indices calculated by Dodge's and Simpson's methods were 5.76+/-2.13 L/min/ m2, 5.86+/-2.31 L/min/m2 respectively with significant correlation to each other(r=0.99, P<0.01). Global ejection fractions using both methods were 69.81+/-8.33%, and 69.69+/-8.20%, respectively (r=0.99, P<0.01). After dividing the left ventricular outline contour into five regions such as posterobasal, diaphragmatic, apical, anterolateral and anterobasal portions, all four models could ascertain regional wall motion abnormalities well(P<0.01). And among them, the Centerline method and the Curved Perimeter method correlated well in assessing wall motion(for each portion r=0.67, 0.84, 0.94, 0.91 and 0.61 respectively, P<0.01). CONCLUSION: In conclusion, we confirmed regional wall motion abnormalities in the various forms of congenital heart disease in spite of normal global ejection fractions, showing that the Centerline and Curved Perimeter methods are preferable methods in the assessment of wall motion in patiens with congenital heart disease.
Cardiac Catheterization
;
Cardiac Catheters
;
Child*
;
Heart Defects, Congenital*
;
Heart Ventricles*
;
Humans
;
Ventricular Function, Left
7.Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry Measurement of Leukocyte Arylsulfatase A Activity Using a Natural Substrate.
Minje HAN ; Sun Hee JUN ; Sang Hoon SONG ; Hyung Doo PARK ; Kyoung Un PARK ; Junghan SONG
Annals of Laboratory Medicine 2015;35(1):165-168
No abstract available.
Adult
;
Cerebroside-Sulfatase/*metabolism
;
Child, Preschool
;
*Chromatography, High Pressure Liquid
;
Enzyme Assays/instrumentation/*methods
;
Female
;
Humans
;
Kinetics
;
Leukocytes/*enzymology
;
Leukodystrophy, Metachromatic/diagnosis/enzymology
;
Male
;
Middle Aged
;
Reference Standards
;
Substrate Specificity
;
Sulfoglycosphingolipids/analysis/metabolism/standards
;
*Tandem Mass Spectrometry/standards
8.Post-Traumatic Growth: The Conception and Neurobiology.
Sang Won JEON ; Changsu HAN ; Joonho CHOI ; Jong Woo PAIK ; Chi Un PAE ; Jeong Ho CHAE
Korean Journal of Psychopharmacology 2015;26(1):1-9
Stress and trauma research has traditionally focused on negative sequelae of adversity. Recently, research has begun to focus on positive outcomes, specifically post-traumatic growth (PTG) - "positive change experienced as a result of the struggle with trauma" - which emphasizes the transformative potential of one's experiences with highly stressful events and circumstances. This article describes the concept of PTG at three different perspectives. In addition we reviewed the neurobiological factors and mechanism of PTG. It has shown that PTG is mediated by adaptive changes in several neural circuits involving numerous neurotransmitter and molecular pathways. Much more study is required to achieve a deeper understanding the biological and psychological underpinnings of PTG, as well as the interactions between these factors. After all, the clinical phenomenology of PTG is very important for mental growth after trauma. The findings of this article provide further directions for research and clinical implication of PTG.
Fertilization*
;
Life Change Events
;
Neurobiology*
;
Neurotransmitter Agents
9.Bruxism Secondary to Hypoxic Brain Injury Treated With Botulinum Toxin-A.
Dong Sun KIM ; Hyeyun KIM ; Sang Jun AN ; Go Un KIM ; Ji Sun KWON ; Hyun Jeong HAN
Journal of the Korean Neurological Association 2012;30(4):367-369
No abstract available.
Brain
;
Brain Injuries
;
Bruxism
10.Clinical Characteristics of Hypernatremia.
Jeong Hoon KIM ; Un Sil JEON ; Jin Suk HAN ; Jae Seok YANG ; Seo Jin LEE ; Curie AHN ; Suhnggwon KIM ; Jung Sang LEE ; Woo Seong HUH ; Jong Ho LEE
Korean Journal of Nephrology 1998;17(4):553-558
Hypematremia is a rare but important medical condition and is associated with mortality rate of 40 to 70%. However, little has been known about its prognostic factors or treatment guidlines. To evaluate the prognostic factors and the outcome following treatment, we reviewed 22 available medical records among twenty five hypernatremic patients (0.2%) in 12841 admissions at medical ward from January to December 1995. We defined hypernatremia as serum sodium concentration more than or equal to 150 mEq/L. Of these patients, two had hypematrernia at admission and the remaining patients became hypernatremic during admission. Mean peak serum sodium concentration was 158 (150-178) mEq/L and mean total body water deficit was 11.4 (6.7-21.3)%. Factors correlated with the development of hypernatremia were diverse and multiple, and the most frequent factor was diminished access to water. Mortality rate was 59%, but mortality was not correlated with age, correction rate of hyper-natremia, primary route of fluid loss, and the severity of hypernatremia or total body water deficit. Mortality rate was higher in patients whose serum sodium concentrations were below 130 mEq/L at admission (P<0.05). In our study, development of hypernatremia from initial hyponatremic state was significantly associated with poor outcome, and age, rapidity of correction, route of fluid loss, and the severity of hypernatremia or total body water deficit were not.
Body Water
;
Humans
;
Hypernatremia*
;
Medical Records
;
Mortality
;
Sodium
;
Water