1.The Formation of Extragraft Bone Bridging after Anterior Cervical Discectomy and Fusion: A Finite Element Analysis.
Shin Won KWON ; Chi Heon KIM ; Chun Kee CHUNG ; Tae Hyun PARK ; Su Heon WOO ; Sung Jae LEE ; Seung Heon YANG
Journal of Korean Neurosurgical Society 2017;60(6):611-619
OBJECTIVE: In addition to bone bridging inside a cage or graft (intragraft bone bridging, InGBB), extragraft bone bridging (ExGBB) is commonly observed after anterior cervical discectomy and fusion (ACDF) with a stand-alone cage. However, solid bony fusion without the formation of ExGBB might be a desirable condition. We hypothesized that an insufficient contact area for InGBB might be a causative factor for ExGBB. The objective was to determine the minimal area of InGBB by finite element analysis. METHODS: A validated 3-dimensional, nonlinear ligamentous cervical segment (C3–7) finite element model was used. This study simulated a single-level ACDF at C5–6 with a cylindroid interbody graft. The variables were the properties of the incorporated interbody graft (cancellous bone [Young’s modulus of 100 or 300 MPa] to cortical bone [10000 MPa]) and the contact area between the vertebra and interbody graft (Graft-area, from 10 to 200 mm²). Interspinous motion between the flexion and extension models of less than 2 mm was considered solid fusion. RESULTS: The minimal Graft-areas for solid fusion were 190 mm², 140 mm², and 100 mm² with graft properties of 100, 300, and 10000 MPa, respectively. The minimal Graft-areas were generally unobtainable with only the formation of InGBB after the use of a commercial stand-alone cage. CONCLUSION: ExGBB may be formed to compensate for insufficient InGBB. Although various factors may be involved, solid fusion with less formation of ExGBB may be achieved with refinements in biomaterials, such as the use of osteoinductive cage materials; changes in cage design, such as increasing the area of polyetheretherketone or the inside cage area for bone grafts; or surgical techniques, such as the use of plate/screw systems.
Biocompatible Materials
;
Diskectomy*
;
Finite Element Analysis*
;
Ligaments
;
Spinal Fusion
;
Spine
;
Transplants
3.Radiation-induced Apoptosis is Differentially Modulated by PTK Inhibitors K562 Cells.
Hyung Sik LEE ; Chang Woo MOON ; Won Joo HUR ; Su Jin JEONG ; Min Ho JEONG ; Jeong Hyeon LEE ; Young Jin LIM ; Heon Joo PARK
The Journal of the Korean Society for Therapeutic Radiology and Oncology 2000;18(1):51-58
PURPOSE: The effect of PTK inhibitors (herbimycin A and genistein) on the induction of radiation-induce d apoptosis in Ph-positive K562 leukemia cell line was investigated. MATERIALS AND METHODS: K562 cells in exponential growth phase were irradiated with a linear accelerator at room temperature. For 6 MV X-ray irradiation and drug treatment, cultures were initiated at 2x10' cells/mL. The cells were irradiated with 10 Gy. Stock solutions of herbimycin A and genistein were prepared in dimethyl sulphoxide (DMSO). After incubation at 37C for 0-48 h, the extent of apoptosis was determined using agarose gel electrophoresis and TUNEL assay. The progression of cells throughth the cel l cycle after irradiation and drug treatment was also determined with flow cytometry. Western blot analysis was used to monitor bcl-2, bcl-X and bax protein levels. RESULTS: Treatment with 10 Gy X-irradiation did not result in the induction of apoptosis. The HMA alone (500 nM) also failed to induce apoptosis. By contrast, incubation of K562 cells with HMA after irradiation resulted in a substantial induction of nuclear condensation and fragmentation by agarose gel electro-phoresis and TUNEL assay. Genistein failed to enhance the ability of X-irradiation to induce DN A fragmentation. Enhancement of apoptosis by H MA was not attributable to downregulation of the bcl-2 or bcl-X anti-apoptotic proteins. When the cells were irradiated and maintained with HMA, the percentage cf cells in G2/M phase decreased to 30-40% at 48 h. On the other hand, cells exposed to 10 Gy X-irradiation alone or maintained with genistein did not show marked cell cycle redistribution. CONCLUSION: We have shown that nanomolar concentrations of the PTK inhibitor HMA synergize with X-irradiation in inducing the apoptosis in Ph (+) K562 leukemia cell line. While, genistein, a PTK inhibitor which is not selective for p2 10""'' failed to enhance the radiation induced apoptosis in K562 cells. It is unlikely that the ability of HMA to enhance apoptosis in K562 cells is attributable to bcl-2 family. It is plausible that the relationship between cell cycle delays and cell death is essential for drug development based on molecular targeting designed to modify radiation-induced apoptosis.
Apoptosis Regulatory Proteins
;
Apoptosis*
;
bcl-2-Associated X Protein
;
Blotting, Western
;
Cell Cycle
;
Cell Death
;
Cell Line
;
Dimethyl Sulfoxide
;
Down-Regulation
;
Electrophoresis, Agar Gel
;
Flow Cytometry
;
Genistein
;
Hand
;
Humans
;
Hydrogen-Ion Concentration
;
In Situ Nick-End Labeling
;
K562 Cells*
;
Leukemia
;
Particle Accelerators
;
Sepharose
4.Primary Malignant Fibrous Histiocytoma of the Mesentery: A Case Report.
Jong Heon PARK ; Jae Woo YEON ; Eun Mee HAN ; Suk Ki JANG ; Su Min KANG ; In Oak AHN
Journal of the Korean Radiological Society 2007;57(6):549-552
A malignant fibrous histiocytoma of the mesentery is rare, and multifocal involvement as a primary tumor is very rare. In this report, a case of malignant fibrous histiocytoma of the mesentery presenting with two masses and multiple peritoneal seeding in a 48-year-old man is described. A physical examination revealed a large, firm, and non-tender mass in the right lower abdomen of the patient. Computed tomography of the lesion revealed a partially, indistinctly marginated and heterogeneously enhancing mass with irregular peritumoral strands in the mesentery of the right lower abdomen, while sonograms of the lesion revealed an ill-defined low-echoic mass. The final pathology demonstrated the presence of a storiform-pleomorphic malignant fibrous histiocytoma.
Abdomen
;
Histiocytoma, Malignant Fibrous*
;
Humans
;
Mesentery*
;
Middle Aged
;
Pathology
;
Physical Examination
;
Ultrasonography
5.Expression of Sialic Acids according to the Differentiation of Cultured Human Nasal Epithelial Cells.
Kyung Sik SUH ; Kyung Su KIM ; Jin Woo CHOI ; Joo Heon YOON ; Jeung Gweon LEE
Korean Journal of Otolaryngology - Head and Neck Surgery 1997;40(5):663-669
BACKGROUND: Sialic acid residues are known to play a key role in the normal function of the glycoconjugates. Recently, with the development of specific sialic acid binding lectins such as Maackia seed agglutinin(MAA) and Sambucus nigra agglutinin(SNA), it has made easier to localize the sialic acid residues by the histochemical staining methods. OBJECTIVES: We were to observe the expression of sialic acids according to the differentiation of cultured human nasal epithelial cells by the immunohistochemistry method using Wheat germ agglutinin(WGA), MAA, and SNA. MATERIALS AND METHODS: Human nasal epithelial cell culture was done as floating method for the induction of differentiation. The cultured cells were fixed with 2.5% glutaraldehyde and the epon 812 was used as embedding material. The immunohistochemistry was done as Lim's method. RESULTS: The WGA and MAA positive reactions were noted from the floating zero day through the fourteenth day. The reactions were positive to the squamous-like cells and differentiating cells(ciliated and secretory epithelial cells). The WGA binding patterns were homogeneous but MAA binding patterns were inhomogeneous. The SNA positive reaction was noted only in the fourteenth day and the reaction was inhomogeneous. These results meant that N-acetyl glucosamine and N-acetyl neuraminic acid(alpha 2,3) galactose were expressed from the floating zero day and N-acetyl neuraminic acid(alpha 2,6) galactose was expressed from the floating fourteenth day. CONCLUSION: N-acetyl neuraminic acid(alpha 2,3) galactose may be more important to the primary defence of human nasal epithelial cell. Due to the inhomogeneity of the reaction, the further study using Lowicryl K4M will be needed.
Cells, Cultured
;
Epithelial Cells*
;
Galactose
;
Glucosamine
;
Glutaral
;
Glycoconjugates
;
Humans*
;
Immunohistochemistry
;
Lectins
;
Maackia
;
N-Acetylneuraminic Acid*
;
Sambucus nigra
;
Sialic Acids*
;
Triticum
6.The Impact of Depressive Symptom on Efficacy and Compliance of Positive Airway Pressure in Obstructive Sleep Apnea
Su Young LEE ; Seong Hwan KIM ; Young Rong BANG ; Sae-Heon JANG ; Woo Yong BAE ; Sang jun KIM
Journal of the Korean Society of Biological Therapies in Psychiatry 2021;27(3):190-199
Objectives:
:The aim of this study was to determine how the efficacy and compliance of positive airway pressure (PAP) varies depending on the depressive symptom with obstructive sleep apnea (OSA).
Methods:
:We collected data about baseline Apnea-Hyponea Index (AHI), sleep and mood state and demographic information from 125 obstructive sleep apnea patients prior to the start of positive airway pressure treatment. The Apnea-Hyponea Index and daytime sleepiness were examined as indicators of efficacy of positive airway pressure and daily average usage time and the utilization rate (%) for more than 4 hours were calculated as indicators of compliance of positive airway pressure at the time of 1, 3 or 9 months after the start of positive airway pressure. Repeated-measures ANOVA and linear mixed model (LMM) with adjusting age, body mass index and baseline Insomnia severity index were used for revealing any significant differences between groups over time passed.
Results:
:This difference was confirmed at 9 months after starting positive airway pressure, between the two groups and the usage rate for more than 4 hours in depressive group was lower than that in non-depression group (56.2% vs. 67.5%).
Conclusions
:We demonstrated that there would be a difference in the compliance of positive airway pressure among patients with obstructive sleep apnea according to depressive state. Therefore, we suggest evaluating depressive symptoms in patients with obstructive sleep apnea before starting positive airway pressure, to increase the compliance of the positive airway pressure, which is essential to maintain the efficacy of the positive airway pressure.
7.Temporomandibular joint morphology in Korean using cone-beam computed tomography: influence of age and gender
Ji-Min YUN ; Young-Jun CHOI ; Su-Heon WOO ; Ui-Lyong LEE
Maxillofacial Plastic and Reconstructive Surgery 2021;43(1):21-
Objectives:
The purpose of this study was to investigate the condylar morphology and position of Koreans using cone-beam computed tomography (CBCT) images. Analyzing the mean values of this study with reference to left and right sides, gender, and age will help to understand the size of the condyle and glenoid fossa, condylar morphology, and temporomandibular joint (TMJ) symmetry for establishing the standard temporomandibular joint structures of Koreans and then design the standard temporomandibular joint prosthesis for Koreans.
Results:
There was no significant result in the condyle size, condyle axis angle, joint space, fossa depth, and mandibular body size between the left and right sides (p > 0.05). On the other hand, the mediolateral width of the condyle and mandibular body size show significantly different with the gender (P < 0.05). Also, significant differences were found in condyle size, joint space, fossa depth, and mandibular body size according to age groups (P < 0.05).
Conclusions
Condylar position and morphology vary according to side, age, and gender. The results of this study are expected to help in customizing a treatment for the patients who need TMJ reconstruction by predicting the TMJ morphology according to age and gender and design the standard temporomandibular joint prosthesis for the Koreans.
8.Psychosocial changes in Medical Students Before and After COVID-19 Social Distancing
Do young KIM ; Woo Jin YANG ; Su Heon LEE ; Seung Hyeon LEE ; Kwi Hwa PARK ; So Jung YUNE
Health Communication 2022;17(2):91-98
Purpose:
: The COVID-19 pandemic has had a far-reaching impact on society. Understanding the changes perceived by medical students is meaningful in that it can suggest the direction of future changes in medical education. The purpose of this study is to investigate the impact of COVID-19 social distancing on psychosocial changes in medical students.
Methods:
: Anxiety and depression caused by COVID-19, changes in fatigue caused by social distancing, areas where significant changes occurred, and changes in social activity participation and media use behavior among medical students who have experienced the COVID-19 pandemic for more than two years by an online survey. Two hundred twenty-one who are 1st and 2nd-year medical students responded, and we analyzed the results by frequency analysis, independent t-test, paired-sample t-test, and ANOVA. Also, we analyzed Post hoc tests with Tamhane T2, which does not assume equal variance.
Results:
: The second year of medical school showed higher anxiety and depression than the first. The students who experienced COVID-19 showed lower anxiety, and the more severe the degree of corona blue experience, the higher the anxiety and depression. And the fatigue felt by medical students is higher now than during COVID-19. Areas where the changes due to COVID-19 were seen a lot, were lifestyle attitudes, learning methods, and human relationships. And also, social activities and media medical students use increased after social distancing.
Conclusion
: Before and After COVID-19 Social Distancing, medical students have experienced many psychosocial changes.
9.Obesity, Obesity Related Disease, and Disability.
Yun Min NA ; Hyun Ah PARK ; Jae Heon KANG ; Young Gyu CHO ; Kyoung Woo KIM ; Yang Im HUR ; Yu Na KIM ; Su Hyeon LEE
Korean Journal of Family Medicine 2011;32(7):412-422
BACKGROUND: Obesity increases the risk of many chronic diseases and contributes to functional disabilities. We assessed the relationship among obesity and obesity related chronic disease and disability in Korean adults. METHODS: This study used data from the 2005 Korean National Health and Nutrition Examination Survey. A total of 5,462 persons (2,325 men, 3,137 women) aged 20 years and older were included in this analysis. Obesity was measured by body mass index and abdominal obesity was by waist circumference. Information on the presence of chronic diseases was based on the self-report of having been diagnosed by physicians. Functional disability was assessed using the Korean activities of daily living (K-ADL) and the Korean instrumental ADL (K-IADL) scales. RESULTS: The relationship between obesity and prevalence of obesity-related chronic diseases was higher in the older aged group (>60 years for men, >70 years for women) than in the younger aged group. Waist circumference was more related to a higher prevalence of chronic diseases than body mass index in the younger aged group. Abdominal obesity increased the risk (odds ratio, 2.59; 95% confidence interval, 1.19 to 5.66) of having limitation in activities of daily living for the younger aged men after adjustments for age, smoking status, presence of chronic diseases, and body mass index. Body mass index was not associated with disability in either men or women. CONCLUSION: The association between obesity and prevalence of chronic disease differed depending on age and sex. It is important to control abdominal obesity to prevent disability in younger aged men.
Activities of Daily Living
;
Aged
;
Body Mass Index
;
Chronic Disease
;
Humans
;
Male
;
Nutrition Surveys
;
Obesity
;
Obesity, Abdominal
;
Prevalence
;
Smoke
;
Smoking
;
Waist Circumference
10.The Financial Burden of Asthma: A Nationwide Comprehensive Survey Conducted in the Republic of Korea.
Chang yup KIM ; Heung Woo PARK ; Su Kyoung KO ; Suk Il CHANG ; Hee Bom MOON ; You Young KIM ; Sang Heon CHO
Allergy, Asthma & Immunology Research 2011;3(1):34-38
PURPOSE: Asthma-related morbidity and mortality are increasing, and the financial burden imposed by this condition will substantially increase. Nevertheless, little information is available regarding the nature and magnitude of the burden due to asthma at the national level. This study was conducted to characterize the financial burden imposed by asthma in the Republic of Korea at the national level. METHODS: The overall prevalence of asthma and the costs of related medical services were determined using data from the National Health Insurance Corporation, which is responsible for the National Health Insurance scheme. Indirect costs, including expenditures on complementary and alternative medicines, and the economic impact of an impaired quality of life (intangible costs) were estimated by surveying 660 asthmatics, and these estimates were transformed to the national level using the prevalence of asthma. RESULTS: The prevalence of asthma and total costs related to the disease in 2004 were 4.19% and $2.04 billion, respectively. Direct costs and indirect costs contributed equally to total costs (46.9% and 53.1%, respectively). However, when intangible costs were included, total costs rose to $4.11 billion, which was equivalent to 0.44% of the national gross domestic product in 2004. CONCLUSIONS: The results provide evidence that asthma is a major health cost factor in the Republic of Korea and that intangible costs associated with asthma are significant cost drivers.
Asthma
;
Gross Domestic Product
;
Health Care Costs
;
Health Expenditures
;
National Health Programs
;
Prevalence
;
Quality of Life
;
Republic of Korea