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
2.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
3.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.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.
7.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.
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.CT of Normal Variations of the Minute Central Skull Base Foramina.
Jee Hee KANG ; Hyung Jin KIM ; Choong Kun HA ; Jae Woo YEON ; Cheol Su OK ; Young Kook CHO ; Myung Kwan LIM ; Eul Hye SEOK ; Han HEON ; Chang Hae SUH
Journal of the Korean Radiological Society 1999;41(6):1209-1214
PURPOSE: To evaluate the CT appearance of normal variations in the minute central skull base foramina in infants and children. MATERIALS AND METHODS: One hundred and fourteen children under the age of 17 years without skull base abnormality underwent CT scanning. A high spatial frequency algorithm was used, and contiguous axial scanning parallel to the orbitomeatal line was performed from the foramen magnum to the orbital roof, with a 1-mm slice thickness. The presence or absence of eight foramina, pseudoforamina, or ossification centers including anterior presphenoidal foramen, posterior presphenoidal foramen, rostro-orbital pseudoforamen, intralateromedial postsphenoidal pseudoforamen, intrapostsphenoidal pseudoforamen, spheno-occipital pseudo-foramen, canalis basilaris medianus and intrasynchondral ossified bodies was analysed according to age. The presence of foramina or pseudoforamina was indicated if a ring-shaped structure was seen on two or more CT scans at the location anatomically predicted, and intrasynchondral ossified bodies were indicated if linear or dot-like structures with high attenuation accompanied spheno-occipital synchondrosis. RESULTS: CT indicated that within a certain age range, various kinds of foramina, pseudoforamina, and ossification centers were frequent. The anterior presphenoidal foramen was most commonly seen in infants aged 1-12 months (16/17, 94 %); the posterior presphenoidal foramen in children less than 2 years old(27/37, 73 % ) ; the rostro-orbital pseudoforamen in children aged 2 -5 years (9/17, 53%); intrapostsphenoidal pseudoforamen in children 6 -12 years old(20/37, 54%) and spheno-occipital pseudoforamen and intrasynchondral ossified bodies in children aged 13 -16 years. The canalis basilaris medianus was identified in about 20 % of all subjects regardless of age. CONCLUSION: Development of the minute central skull base foramina varied greatly according to age. Knowledge of the CT appearances of such embryologic variants of the central skull base should not only help Provide an understanding of complex skull base anatomy but also identify abnormal skull base development.
Child
;
Foramen Magnum
;
Humans
;
Infant
;
Orbit
;
Skull Base*
;
Skull*
;
Tomography, X-Ray Computed
10.Comparison on Endoscopic Hemoclip and Hemoclip Combination Therapy in Non-variceal Upper Gastrointestinal Bleeding Patients Based on Clinical Practice Data: Is There Difference between Prospective Cohort Study and Randomized Study?.
Su Hyun LEE ; Jin Tae JUNG ; Dong Wook LEE ; Chang Yoon HA ; Kyung Sik PARK ; Si Hyung LEE ; Chang Heon YANG ; Youn Sun PARK ; Seong Woo JEON
The Korean Journal of Gastroenterology 2015;66(2):85-91
BACKGROUND/AIMS: Endoscopic hemoclip application is an effective and safe method of endoscopic hemostasis. We conducted a multicenter retrospective study on hemoclip and hemoclip combination therapy based on prospective cohort database in terms of hemostatic efficacy not in clinical trial but in real clinical practice. METHODS: Data on endoscopic hemostasis for non-variceal upper gastrointestinal bleeding (NVUGIB) were prospectively collected from February 2011 to December 2013. Among 1,584 patients with NVUGIB, 186 patients treated with hemoclip were enrolled in this study. Subjects were divided into three groups: Group 1 (n=62), hemoclipping only; group 2 (n=88), hemoclipping plus epinephrine injection; and group 3 (n=36), hemocliping and epinephrine injection plus other endoscopic hemostatic modalities. Primary outcomes included rebleeding, other therapeutic management, hospitalization period, fasting period and mortality. Secondary outcomes were bleeding associated mortality and overall mortality. RESULTS: Active bleeding and peptic ulcer bleeding were more common in group 3 than in group 1 and in group 2 (p<0.001). However, primary outcomes (rebleeding, other management, morbidity, hospitalization period, fasting period and mortality) and secondary outcomes (bleeding associated mortality and total mortality) were not different among groups. CONCLUSIONS: Combination therapy of epinephrine injection and other modalities with hemoclips did not show advantage over hemoclipping alone in this prospective cohort study. However, there is a tendency to perform combination therapy in active bleeding which resulted in equivalent hemostatic success rate, and this reflects the role of combination therapy in clinical practice.
Adult
;
Aged
;
Angiography
;
Cohort Studies
;
Combined Modality Therapy
;
Databases, Factual
;
Epinephrine/therapeutic use
;
Female
;
Gastrointestinal Hemorrhage/etiology/*therapy
;
*Hemostasis, Endoscopic
;
Humans
;
Male
;
Middle Aged
;
Prospective Studies
;
Proton Pump Inhibitors/therapeutic use
;
Retrospective Studies
;
Stomach Ulcer/complications/drug therapy/pathology
;
Surgical Instruments
;
Treatment Outcome