1.Deduction and Verification of Optimal Factors for Stent Structure and Mechanical Reaction Using Finite Element Analysis.
Dong Min JEON ; Won Gyun JUNG ; Han Ki KIM ; Sang Ho KIM ; Il Gyun SHIN ; Hong Seok JANG ; Tae Suk SUH
Korean Journal of Medical Physics 2010;21(2):201-208
Recently, along with technology development of endoscopic equipment, a stent has been developed for the convenience of operation, shortening of recovery times, and reduction of patient's pain. To this end, optimal factors are simulated for the stent structure and mechanical reaction and verified using finite element analysis. In order to compare to present commercialized product such as Zilver (Cook, Bloomington, Indiana, USA) and S.M.A.R.T (Cordis, Bridgewater Towsnhip, New Jersey, USA), mechanical impact factors were determined through Taguchi factor analysis, and flexibility and expandability of all the products including ours were tested using finite element analysis. Also, important factors were sought that fulfill the optimal condition using central composition method of response surface analysis, and optimal design were carried out based on the important factors. From the centra composition method of Response surface analysis, it is found that importat factors for flexibility is stent thickness (T) and unit area (W) and those for expandability is stent thickness (T). In results, important factors for optimum condition are 0.17 mm for stent thickness (T) and 0.09 mm2 for unit area (W). Determined and verified by finite element analysis in out research institute, a stent was manufactured and tested with the results of better flexibility and expandability in optimal condition compared to other products. Recently, As Finite element analysis stent mechanical property assessment for research much proceed. But time and reduce expenses research rarely stent of optimum coditions. In this research, Important factor as mechanical impact factor stent Taguchi factor analysis arrangement to find flexibility with expansibility as Finite element analysis. Also, Using to Center composition method of Response surface method appropriate optimized condition searching for important factor, these considering had design optimized. Production stent time and reduce expenses was able to do the more coincide with optimum conditions. These kind of things as application plan industry of stent development period of time and reduce expenses etc. be of help to many economic development.
Academies and Institutes
;
Finite Element Analysis
;
Indiana
;
New Jersey
;
Pliability
;
Stents
2.The Utility of Pleural Adenosine Deaminase for Diagnosis of Differentiating Tuberculous Pleural Effusion in Children.
Gyung Ho KWON ; Jong Suk KIM ; Jong Su JUNG ; Jang Hoon LIM ; Gyun Woo LEE
Pediatric Allergy and Respiratory Disease 2002;12(2):146-153
PURPOSE: The aim of this study is to evaluate the value of pleural adenosine deaminase (ADA) in differentiating tuberculous pleural effusion from non tuberculous pleural effusion of children. METHODS: We measured pleural ADA activity in patients with pleural effusion whose age were from seven months to seventeen years from January 1995 to October 2001. By some criteria the patients were grouped to tuberculous pleural effusion, bacterial effusion, mycoplasma effusion, malignant effusion, and other effusion. RESULTS: The mean pleural ADA activity in tuberculous pleural effusion was 86.2+/-27.3 U/L. Pleural ADA activities in bacterial effusion, mycoplasma effusion, malignant effusion, other effusion were 32.6+/-20.1, 22.1+/-15.4, 23.1+/-10.9, 36.7+/-28.4 U/L, respectively. Pleural ADA activity in tuberculous pleural effusion was significantly higher than in any other group(P<0.001). At a level of 50 U/L, the sensitivity, specificity, positive predictive value (ppv), and and negative predictive value(npv) for the identification of tuberculous pleural effusion from nontuberculous pleural effusion were calculated at 93.8%, 84.8%, 81.1%, 95.1%, respectively. CONCLUSION: Pleural ADA is a useful test in the diagnosis of tuberculous pleural effusion of children from nontuberculous pleural effusion.
Adenosine Deaminase*
;
Adenosine*
;
Child*
;
Diagnosis*
;
Humans
;
Mycoplasma
;
Pleural Effusion*
;
Sensitivity and Specificity
3.Results of Revision Surgery and Causes of Unstable Total Knee Arthroplasty.
In Soo SONG ; Doo Hoon SUN ; Jae Gyun CHON ; Sung Won JANG ; Dong Hyuk SUN
Clinics in Orthopedic Surgery 2014;6(2):165-172
BACKGROUND: The aim of this study was to evaluate causes of unstable total knee arthroplasty and results of revision surgery. METHODS: We retrospectively reviewed 24 knees that underwent a revision arthroplasty for unstable total knee arthroplasty. The average follow-up period was 33.8 months. We classified the instability and analyzed the treatment results according to its cause. Stress radiographs, postoperative component position, and joint level were measured. Clinical outcomes were assessed using the Hospital for Special Surgery (HSS) score and range of motion. RESULTS: Causes of instability included coronal instability with posteromedial polyethylene wear and lateral laxity in 13 knees, coronal instability with posteromedial polyethylene wear in 6 knees and coronal and sagittal instability in 3 knees including post breakage in 1 knee, global instability in 1 knee and flexion instability in 1 knee. Mean preoperative/postoperative varus and valgus angles were 5.8degrees/3.2degrees (p = 0.713) and 22.5degrees/5.6degrees (p = 0.032). Mean postoperative alpha, beta, gamma, delta angle were 5.34degrees, 89.65degrees, 2.74degrees, 6.77degrees. Mean changes of joint levels were from 14.1 mm to 13.6 mm from fibular head (p = 0.82). The mean HSS score improved from 53.4 to 89.2 (p = 0.04). The average range of motion was changed from 123degrees to 122degrees (p = 0.82). CONCLUSIONS: Revision total knee arthroplasty with or without a more constrained prosthesis will be a definite solution for an unstable total knee arthroplasty. The solution according to cause is very important and seems to be helpful to avoid unnecessary over-constrained implant selection in revision surgery for total knee instability.
Aged
;
Aged, 80 and over
;
Arthroplasty, Replacement, Knee/*adverse effects
;
Female
;
Humans
;
Joint Instability/*etiology
;
Knee Joint/*surgery
;
Knee Prosthesis
;
Male
;
Middle Aged
;
*Prosthesis Failure
;
Reoperation
;
Retrospective Studies
4.How Many High Risk Korean Patients with Osteopenia Could Overlook Treatment Eligibility?.
Dae Hyun YOON ; Dong Hyuk CHOI ; Hyun Gyun JUNG ; Ju Young HEO ; Young Jae JANG ; Yong Soo CHOI
Asian Spine Journal 2014;8(6):729-734
STUDY DESIGN: Retrospective study. PURPOSE: To determine the prevalence of high risk patient with osteopenia requiring pharmacologic treatment and investigate the difference of 10-year fracture probability whether bone mineral density (BMD) include or not in Korean FRAX model. OVERVIEW OF LITERATURE: Many people with the fracture have osteopenia rather than osteoporosis, and BMD alone could be considered as a chance to prevent fracture. METHODS: Three hundred sixty-nine patients who was diagnosed as osteopenia were divided into two groups according to age (group 1, under 65 years; group 2, over 65 years), and 10-year fracture probabilities were calculated by FRAX algorithm with and without femur neck T-score. RESULTS: The high risk patients of the fracture who had above 3% of 10-year hip fracture probability were 15 cases in group 1 and 121 cases in group 2. In 193 patients of group 1, the mean 10-year fracture probability with BMD was significantly higher than the results without BMD (hip fracture: p=0.04, major osteoporotic fracture: p=0.01). Unlike the results of the group 1, the mean 10-year fracture probability without BMD was significantly higher than the results with BMD in 176 patients of group 2 (hip fracture: p=0.01, major osteoporotic fracture: p=0.01). CONCLUSIONS: Total of 136 cases (36.8%) as a high risk of the fracture with osteopenia could be overlooked treatment eligibility in Korean. The Korean FRAX model without BMD could be effective in predicting fracture risk especially in the individuals who were over 65 years.
Bone Density
;
Bone Diseases, Metabolic*
;
Femur Neck
;
Hip
;
Humans
;
Osteoporosis
;
Osteoporotic Fractures
;
Prevalence
;
Retrospective Studies
;
Risk Assessment
5.Prevalence of atrial fibrillation in general population in Kangwon Province.
Myoung Kuk JANG ; Ja Young LEE ; Seong Gyun KIM ; Kyu Heung CHO ; Yong Sang YANG ; Dong Seok YOON ; Sung Heon CHAE
Journal of the Korean Academy of Family Medicine 2001;22(2):178-183
BACKGROUND: Atrial fibrillation is the commonest arrhythmia seen in clinical practice. However, there have been no epidemiologic data on its prevalence in general population of Korea. We performed this study to investigate the prevalence of atrial fibrillation in Korea. METHODS: From March 1, 1999 to July 31, 2000, Kangwon Branch, Korea Association of Health (KAH) parformed electrocardiograms to investigate the health status in the general public in Kangwon Province. We analyzed these data by of chi square(2) test. RESULTS: A total of 45,133 persons participated in the health screening performed by KAH. The number of persons above 40 years old were 13,768, with men and women 6,367 (46.2%) and 7,401 (53.8%)respectively. Prevalence among those above 40 years old was 0.72% and the prevalence among men, 0.96% (61 persons) was significantly higher than that of women, 0.51% (38 persons)(p<0.01). In the group above 60 years old with the prevalence of 1.24%, a similar phenomenon was observed with 1.57% (40 persons) in men and 0.97% (29 persons) in women (p<0.05). CONCLUSION: Prevalence of atrial fibrillation became higher as age increased, specifically in persons older than 40 years.
Adult
;
Arrhythmias, Cardiac
;
Atrial Fibrillation*
;
Electrocardiography
;
Female
;
Gangwon-do*
;
Humans
;
Korea
;
Male
;
Mass Screening
;
Middle Aged
;
Prevalence*
6.Comparison of symptomatic and asymptomatic pulmonary embolism in proximal deep vein thrombosis.
Dong Hun KIM ; Young Woo SEO ; Gyun Moo KIM ; Seung Hyun KO ; Jae Seok JANG ; Tae Chang JANG
Yeungnam University Journal of Medicine 2017;34(2):231-237
BACKGROUND: Deep vein thrombosis (DVT) and pulmonary embolism (PE) are conditions with significant morbidity and mortality. Proximal DVT has a significant association with PE and possible fatal outcomes. Traditionally, PE is subdivided into symptomatic PE and asymptomatic PE, which have different treatments, preventions and prognoses. The growing utilization of computed tomography pulmonary angiography has led to increased detection of PE in DVT patients. This study examined the clinical characteristics and compared symptomatic PE and asymptomatic PE following proximal DVT. METHODS: The medical records of 258 DVT inpatients from July, 2012 to June, 2015 were reviewed retrospectively. After excluding the patients who did not performed PE evaluation and were not diagnosed with PE, 95 patients diagnosed with PE following proximal DVT were enrolled in this study. They were divided into the symptomatic PE group and asymptomatic PE group. RESULTS: The body weight, body mass index, thrombus size, thrombus length and location were similar in the two groups. The symptomatic PE following proximal DVT group showed an older age, higher incidence of emergency department access (85.0% vs. 38.7%, p < 0.001) and preceding infection (25.0% vs. 1.3%, p < 0.001) as well as a higher incidence of immobilization (45.0% vs 13.3%, p=0.016). In the multivariate logistic regression study, preceding infection and emergency department access showed significant association with symptomatic PE. CONCLUSION: In proximal DVT inpatients, symptomatic PE was associated with emergency department access and preceding infection. The possibility of a symptomatic PE event should be considered in proximal DVT patients, especially those who were admitted through the emergency department and had preceding infection.
Angiography
;
Body Mass Index
;
Body Weight
;
Emergency Service, Hospital
;
Fatal Outcome
;
Humans
;
Immobilization
;
Incidence
;
Inpatients
;
Logistic Models
;
Medical Records
;
Mortality
;
Prognosis
;
Pulmonary Embolism*
;
Retrospective Studies
;
Thrombosis
;
Venous Thrombosis*
7.Comparison of symptomatic and asymptomatic pulmonary embolism in proximal deep vein thrombosis
Dong Hun KIM ; Young Woo SEO ; Gyun Moo KIM ; Seung Hyun KO ; Jae Seok JANG ; Tae Chang JANG
Yeungnam University Journal of Medicine 2017;34(2):231-237
BACKGROUND: Deep vein thrombosis (DVT) and pulmonary embolism (PE) are conditions with significant morbidity and mortality. Proximal DVT has a significant association with PE and possible fatal outcomes. Traditionally, PE is subdivided into symptomatic PE and asymptomatic PE, which have different treatments, preventions and prognoses. The growing utilization of computed tomography pulmonary angiography has led to increased detection of PE in DVT patients. This study examined the clinical characteristics and compared symptomatic PE and asymptomatic PE following proximal DVT.METHODS: The medical records of 258 DVT inpatients from July, 2012 to June, 2015 were reviewed retrospectively. After excluding the patients who did not performed PE evaluation and were not diagnosed with PE, 95 patients diagnosed with PE following proximal DVT were enrolled in this study. They were divided into the symptomatic PE group and asymptomatic PE group.RESULTS: The body weight, body mass index, thrombus size, thrombus length and location were similar in the two groups. The symptomatic PE following proximal DVT group showed an older age, higher incidence of emergency department access (85.0% vs. 38.7%, p < 0.001) and preceding infection (25.0% vs. 1.3%, p < 0.001) as well as a higher incidence of immobilization (45.0% vs 13.3%, p=0.016). In the multivariate logistic regression study, preceding infection and emergency department access showed significant association with symptomatic PE.CONCLUSION: In proximal DVT inpatients, symptomatic PE was associated with emergency department access and preceding infection. The possibility of a symptomatic PE event should be considered in proximal DVT patients, especially those who were admitted through the emergency department and had preceding infection.
Angiography
;
Body Mass Index
;
Body Weight
;
Emergency Service, Hospital
;
Fatal Outcome
;
Humans
;
Immobilization
;
Incidence
;
Inpatients
;
Logistic Models
;
Medical Records
;
Mortality
;
Prognosis
;
Pulmonary Embolism
;
Retrospective Studies
;
Thrombosis
;
Venous Thrombosis
8.A clinical study on the care of odontogenic infections in the patients with major bleeding disorders.
Jong Bae KIM ; Won Gyun CHUNG ; Hie Jin NOH ; Sun Ok JANG ; Jae Ha YOO ; Sang Kwon HAN ; Jae Hyung CHUNG ; Byung Wook KIM
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2003;29(5):330-337
This is a retrospective study on the care of odontogenic infections in admission patients with major bleeding disorders. The study was based on a series of 514 patients treated at Dong San Medical Center, Wonju Christian Hospital and Il San Health Insurance Hospital, from Jan.1, 2000, to Dec.31,2002. The obtained results were as follows : 1. The cardiovascular disease was the most frequent cause of the systemic diseases with major bleeding disorders, and liver disease, cerebrovascular disease and renal failure were next in order of frequency. But, there was the most frequent dental consultation in the liver disease, owing to the many odontogenic infectious diseases. 2. Male prediction (66.3%) was almost existed in the odontogenic infectious patients with major bleeding disorders. But, there was slight female prediction (53.4%) in the cardiovascular disease. 3. The most common age group of the odontogenic infectious patients with major bleeding disorders was the fifty decade(27.2%), followed by the forty, sixtyand thirty decade in order. 4. In the contents of chief complaints on the odontogenic infectious patients with major bleeding disorder, peak incidence was occurred as toothache (42.2%), followed by intraoral bleeding, ulcer pain, dental extraction in order. 5. In the diagnosis group of odontogenic infectious diseases, periodontitis, pulpitis and periapical abscess were more common. 6. In the treatment group of odontogenic infectious diseases, the most frequent incidence(44.2%) was showed in primary endodontic drainage(pulp extirpation, occlusal reduction and canal opening drainage) and followed by the incision and drainage, the medications and oral hygiene instruction, scaling, indirect pulp capping in order.
Cardiovascular Diseases
;
Communicable Diseases
;
Dental Pulp Capping
;
Diagnosis
;
Drainage
;
Female
;
Gangwon-do
;
Hemorrhage*
;
Humans
;
Incidence
;
Insurance, Health
;
Liver Diseases
;
Male
;
Oral Hygiene
;
Periapical Abscess
;
Periodontitis
;
Pulpitis
;
Renal Insufficiency
;
Retrospective Studies
;
Toothache
;
Ulcer
9.Diagnostic Value of Elevated D-Dimer Level in Venous Thromboembolism in Patients With Acute or Subacute Brain Lesions.
Yeon Jin KIM ; Sun IM ; Yong Jun JANG ; So Young PARK ; Dong Gyun SOHN ; Geun Young PARK
Annals of Rehabilitation Medicine 2015;39(6):1002-1010
OBJECTIVE: To define the risk factors that influence the occurrence of venous thromboembolism (VTE) in patients with acute or subacute brain lesions and to determine the usefulness of D-dimer levels for VTE screening of these patients. METHODS: Medical data from January 2012 to December 2013 were retrospectively reviewed. Mean D-dimer levels in those with VTE versus those without VTE were compared. Factors associated with VTE were analyzed and the odds ratios (ORs) were calculated. The D-dimer cutoff value for patients with hemiplegia was defined using a receiver operating characteristic (ROC) curve. RESULTS: Of 117 patients with acute or subacute brain lesions, 65 patients with elevated D-dimer levels (mean, 5.1+/-5.8 mg/L; positive result >0.55 mg/L) were identified. Logistic regression analysis showed that the risk of VTE was 3.9 times higher in those with urinary tract infections (UTIs) (p=0.0255). The risk of VTE was 4.5 times higher in those who had recently undergone surgery (p=0.0151). Analysis of the ROC showed 3.95 mg/L to be the appropriate D-dimer cutoff value for screening for VTE (area under the curve [AUC], 0.63; 95% confidence interval [CI], 0.5-0.8) in patients with acute or subacute brain lesions. This differs greatly from the conventional D-dimer cutoff value of 0.55 mg/L. D-dimer levels less than 3.95 mg/L in the absence of surgery showed a negative predictive value of 95.8% (95% CI, 78.8-99.8). CONCLUSION: Elevated D-dimer levels alone have some value in VTE diagnosis. However, the concomitant presence of UTI or a history of recent surgery significantly increased the risk of VTE in patients with acute or subacute brain lesions. Therefore, a different D-dimer cutoff value should be applied in these cases.
Brain Diseases
;
Brain*
;
Diagnosis
;
Hemiplegia
;
Humans
;
Logistic Models
;
Mass Screening
;
Odds Ratio
;
Pulmonary Embolism
;
Retrospective Studies
;
Risk Factors
;
ROC Curve
;
Urinary Tract Infections
;
Venous Thromboembolism*
;
Venous Thrombosis
10.Parathyroid hormone accelerates decompensation following left ventricular hypertrophy.
Hyeseon CHA ; Hyeon Joo JEONG ; Seung Pil JANG ; Joo Yeon KIM ; Dong Kwon YANG ; Jae Gyun OH ; Woo Jin PARK
Experimental & Molecular Medicine 2010;42(1):61-68
Parathyroid hormone (PTH) treatment was previously shown to improve cardiac function after myocardial infarction by enhancing neovascularization and cell survival. In this study, pressure overload-induced left ventricular hypertrophy (LVH) was induced in mice by transverse aortic banding (TAB) for 2 weeks. We subsequently evaluated the effects of a 2-week treatment with PTH or saline on compensated LVH. After another 4 weeks, the hearts of the mice were analyzed by echocardiography, histology, and molecular biology. Echocardiography showed that hearts of the PTH-treated mice have more severe failing phenotypes than the saline-treated mice following TAB with a greater reduction in fractional shortening and left ventricular posterior wall thickness and with a greater increase in left ventricular internal dimension. Increases in the heart weight to body weight ratio and lung weight to body weight ratio following TAB were significantly exacerbated in PTH-treated mice compared to saline-treated mice. Molecular markers for heart failure, fibrosis, and angiogenesis were also altered in accordance with more severe heart failure in the PTH-treated mice compared to the saline-treated mice following TAB. In addition, the PTH-treated hearts were manifested with increased fibrosis accompanied by an enhanced SMAD2 phosphorylation. These data suggest that the PTH treatment may accelerate the process of decompensation of LV, leading to heart failure.
Animals
;
Blotting, Western
;
Echocardiography
;
Hypertrophy, Left Ventricular/*drug therapy/pathology
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Parathyroid Hormone/pharmacology/*therapeutic use
;
Phosphorylation/drug effects
;
Random Allocation
;
Reverse Transcriptase Polymerase Chain Reaction
;
Smad2 Protein/metabolism