1.In silico evaluation of the acute occlusion effect of coronary artery on cardiac electrophysiology and the body surface potential map.
Ah Jin RYU ; Kyung Eun LEE ; Soon Sung KWON ; Eun Seok SHIN ; Eun Bo SHIM
The Korean Journal of Physiology and Pharmacology 2019;23(1):71-79
Body surface potential map, an electric potential distribution on the body torso surface, enables us to infer the electrical activities of the heart. Therefore, observing electric potential projected to the torso surface can be highly useful for diagnosing heart diseases such as coronary occlusion. The BSPM for the heart of a patient show a higher level of sensitivity than 12-lead ECG. Relevant research has been mostly based on clinical statistics obtained from patients, and, therefore, a simulation for a variety of pathological phenomena of the heart is required. In this study, by using computer simulation, a body surface potential map was implemented according to various occlusion locations (distal, mid, proximal occlusion) in the left anterior descending coronary artery. Electrophysiological characteristics of the body surface during the ST segment period were observed and analyzed based on an ST isointegral map. We developed an integrated system that takes into account the cellular to organ levels, and performed simulation regarding the electrophysiological phenomena of the heart that occur during the first 5 minutes (stage 1) and 10 minutes (stage 2) after commencement of coronary occlusion. Subsequently, we calculated the bipolar angle and amplitude of the ST isointegral map, and observed the correlation between the relevant characteristics and the location of coronary occlusion. In the result, in the ventricle model during the stage 1, a wider area of ischemia led to counterclockwise rotation of the bipolar angle; and, during the stage 2, the amplitude increased when the ischemia area exceeded a certain size.
Cardiac Electrophysiology*
;
Computer Simulation*
;
Coronary Occlusion
;
Coronary Vessels*
;
Electrocardiography
;
Electrophysiological Phenomena
;
Electrophysiology
;
Heart
;
Heart Diseases
;
Humans
;
Ischemia
;
Torso
2.The Role of Vibrio vulnificus Capsular Polysaccharide as a Virulence Factor.
Sun Sik CHUNG ; Hyun Chul LEE ; Boo Ahn SHIN ; Shee Eun LEE ; Phil Youl RYU ; Won Seok KIM
Journal of the Korean Society for Microbiology 1998;33(5):425-434
To evaluate the role of capsular polysaccharide (CPS) as a virulence factor, the interaction of V. vulnificus with mouse peritoneal macrophages and serum, which are involved in the clearance of bacteria from blood and other tissues, were examined. In this study, MO6-24/0 (wild strain; hemolysin- and capsule-positive), MO6-24/I' (acapsular spontaneous mutant), CVD 752 (acapsular transposon mutant), and CVD 707 (hemolysin-negative and capsule-positive mutant) were used. The strain with CPS (MO6-24/0 and CVD 707) were more resistant to phagocytosis by mouse peritoneal macrophages compared with acapsular strains (MO6-24/T and CVD 752), and the resistance to phagocytosis was not changed by serum opsonin in the capsular strains. Acapsular strains were more susceptible to serum bactericidal activity than the capsular strains through the classical complement pathway. MO6-24/0 strain were detected in blood, spleen, liver and lung at 4 hours after intraperitoneally infection, whereas CVD 752 were not detected. All tested strains could induced the transcription of inflammatory cytokine gene such as IL-1, IL-6, IL-10 and TNF-u, and their inductions were not decreased by cytochalasin B treatment. This results demonstrate that CPS of V. vulnificus plays an important role in V. vulnificus infection through interfering nonspecific host defense system such as blood clearance and phagocytosis.
Animals
;
Bacteria
;
Complement Pathway, Classical
;
Cytochalasin B
;
Interleukin-1
;
Interleukin-10
;
Interleukin-6
;
Liver
;
Lung
;
Macrophages, Peritoneal
;
Mice
;
Phagocytosis
;
Spleen
;
Vibrio vulnificus*
;
Vibrio*
;
Virulence*
3.A case of prenatal ultrasonographic diagnosis of infantile polycystic kidney disease.
Ju Lee KIM ; Kyeong Seok JANG ; Mu Hyun RYU ; Young Don YOON ; Tae Bok SONG ; Eun Kyung KIM
Korean Journal of Obstetrics and Gynecology 1993;36(7):2768-2773
No abstract available.
Diagnosis*
;
Polycystic Kidney Diseases*
4.A Comparison Technetium-99m and Iodine-123 Scan in Thyroid Hot Nodules.
Eun Sook KIM ; Seok Jun HONG ; Young Ki SONG ; Jin Sook RYU ; Dae Hyuk MOON ; Ki Soo KIM
Journal of Korean Society of Endocrinology 1999;14(2):339-345
BACKGROUND: Pertechnetate ( Tc) has been widely employed for thyroid imaging. While pertechnetate and radioiodide have usually similar results in identifying thyroid nodules, occasionally differences have been noted. We intended to observe that the thyroid nodules which appeared to be hot on pertechnetate and to compare them with the images by radioiodide. METHODS: 'I scan was performed to thirty-eight cases (mean age: 48.9 +/- 13.2) presenting as hot nodule on Tc scan. Thyroid function test and pathologic diagnosis were obtained in all patients. RESULTS: Of the 38 patients, 24 had euthyroidism, 13 had hyperthyroidism, and 1 had hypothyroidism. Thirty patients had adenomatous goiter, 4 papillary carcinoma, 3 Hashimotos thyroiditis, and 1 had HQrthle cell tumor. 28 of 38 patients showed similar images, but the remaining 10 patients(26.3%) revealed discordant images on Tc and 131I scan. Among the concordant cases, 23 had adenomatous goiter, 3 had papillary carcinoma, and 2 had Hashimotos thyroiditis. Among the discordant cases, 7 had adenomatous goiter, 1 had papillary carcinoma, 1 had Hashimotos thyroiditis, and 1 had HQrthle cell tumor. The incidence of malignancy was 10.7% of concordant cases, and 20% of discordant cases and was revealed statistically insignificant (p>0.05). CONCLUSION: We observed higher incidence of malignancy in patients presenting hot nodules on 99mTc scan than ever reported. Fine needle aspiration should be performed to all patients with hot nodules and the 'I scan would not be recommended for further diagnostic study.
Biopsy, Fine-Needle
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Carcinoma, Papillary
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Diagnosis
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Goiter
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Humans
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Hyperthyroidism
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Hypothyroidism
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Incidence
;
Sodium Pertechnetate Tc 99m
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Thyroid Function Tests
;
Thyroid Gland*
;
Thyroid Nodule
;
Thyroiditis
5.The Relationships of Internet Addiction, Depression, and Suicidal ideation in Adolescents.
Eun Jung RYU ; Kwi Soon CHOI ; Jeong Seok SEO ; Bum Woo NAM
Journal of Korean Academy of Nursing 2004;34(1):102-110
PURPOSE: This study was done to identify the state of internet addiction and to investigate the relationships among internet addiction, depression and suicidal ideation in adolescents. METHOD: Participants were 1,670 high school students in an urban city. The Internet Addiction Scale was used to measure internet addiction, the DISC-MDD-SQ was used to measure depression, and the Suicidal Ideation Questionnaire-JR was used to measure suicidal ideation. RESULT: 38.1% of participants were perceived to be in the early stages of internet addiction and 1.5% reported heavy addiction. Overall the internet addiction scale score was 37.57(+/-12.52). The differences of internet addiction in sample characteristics were found to be significant in rank in class. The differences in DISC-MDD-SQ and IAS scores among the states of internet addiction were statistically significant. The level of internet addiction correlated positively to the level of depression and suicidal ideation. CONCLUSION: Based upon these findings, there were significant positive correlations among Internet addiction, depression, and suicidal ideation in adolescents. As schools are often the first line for the identification of potential life-threatening behaviors, nurses, especially school-based health professionals, need to be cognizant of measures and procedures for the assessment of Internet addiction, depression, and suicidal ideation.
Adolescent
;
*Adolescent Psychology
;
Behavior, Addictive/diagnosis/*psychology
;
Depression/diagnosis/*psychology
;
Female
;
Humans
;
*Internet
;
Male
;
Suicide/*psychology
6.Initial Depressive Episodes Affect the Risk of Suicide Attempts in Korean Patients with Bipolar Disorder.
Vin RYU ; Duk In JON ; Hyun Sang CHO ; Se Joo KIM ; Eun LEE ; Eun Joo KIM ; Jeong Ho SEOK
Yonsei Medical Journal 2010;51(5):641-647
PURPOSE: Suicide is a major concern for increasing mortality in bipolar patients, but risk factors for suicide in bipolar disorder remain complex, including Korean patients. Medical records of bipolar patients were retrospectively reviewed to detect significant clinical characteristics associated with suicide attempts. MATERIALS AND METHODS: A total of 579 medical records were retrospectively reviewed. Bipolar patients were divided into two groups with the presence of a history of suicide attempts. We compared demographic characteristics and clinical features between the two groups using an analysis of covariance and chi-square tests. Finally, logistic regression was performed to evaluate significant risk factors associated with suicide attempts in bipolar disorder. RESULTS: The prevalence of suicide attempt was 13.1% in our patient group. The presence of a depressive first episode was significantly different between attempters and nonattempters. Logistic regression analysis revealed that depressive first episodes and bipolar II disorder were significantly associated with suicide attempts in those patients. CONCLUSION: Clinicians should consider the polarity of the first mood episode when evaluating suicide risk in bipolar patients. This study has some limitations as a retrospective study and further studies with a prospective design are needed to replicate and evaluate risk factors for suicide in patients with bipolar disorder.
Adult
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Asian Continental Ancestry Group
;
Bipolar Disorder/*complications/*psychology
;
Depressive Disorder/complications/*psychology
;
Female
;
Humans
;
Korea
;
Male
;
Middle Aged
;
Retrospective Studies
;
Risk Factors
;
Suicide, Attempted/*psychology/statistics & numerical data
;
Young Adult
7.Causes, Clinical Features and Functional Outcome of Pediatric Stroke.
Ju Seok RYU ; Jin Hong PARK ; Eun Ha PARK ; Eun Hye CHA ; In Young SUNG
Journal of the Korean Academy of Rehabilitation Medicine 2009;33(3):276-281
OBJECTIVE: To investigate the changes of causes, clinical features, and functional outcomes in childhood strokes. METHOD: This study included 152 patients, aged from 1 to 18 years, who were diagnosed with stroke and admitted to a tertiary hospital between January 2000 and April 2004. All medical records and neurologic images of the patients were reviewed. A parental questionnaire was used to investigate patients' functional outcomes. These results were compared with those of the previous study performed in the same hospital in 2001. RESULTS: The number of hemorrhagic stroke was 78 (51.3%) and that of ischemic stroke was 74 (48.7%). When compared to the previous study, the incidence of hemorrhagic stroke especially above the age of 10 years decreased and that of ischemic stroke below the age of 10 years increased. The causes of stroke were arteriovenous malformation (AVM, 42.8%), Moyamoya disease (37.5%), vasculitis (5.3%), cardiac disease (3.9%), hematologic disease (2.0%), and undetermined (8.5%). Common clinical features were headache (53.8%), vomiting (43.6%) and loss of consciousness (28.2%) in the hemorrhagic stroke, and hemiparesis (94.6%), headache (35.1%) and speech disorder (31.1%) in the ischemic stroke. 86.0% of the hemorrhagic and 64.8% of the ischemic stroke patients were categorized in the 'good' outcome group. CONCLUSION: The incidence of ischemic stroke increased to the similar level of hemorrhagic stroke. The most common causes were AVM in the hemorrhagic and Moyamoya disease in the ischemic stroke. Most of these patients showed good functional outcome, regardless of the causes of stroke.
Aged
;
Arteriovenous Malformations
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Child
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Headache
;
Heart Diseases
;
Hematologic Diseases
;
Humans
;
Incidence
;
Medical Records
;
Moyamoya Disease
;
Parents
;
Paresis
;
Surveys and Questionnaires
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Stroke
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Tertiary Care Centers
;
Unconsciousness
;
Vasculitis
;
Vomiting
8.Current Progress of Next Generation Battery of Toxicology-Cellular and Molecular Toxicology, and Toxicogenomics.
Jae Chun RYU ; Seok joo YOON ; Jong Eun LEE ; Youn Jung KIM
Genomics & Informatics 2004;2(4):153-162
No abstract available.
Toxicogenetics*
;
Toxicology*
9.Quantitative CT of Lung in Healthy Koreans :Evaluation with PULMO-CT.
Jae Young CHOI ; Seok Jin CHOI ; Ik Dae KIM ; Ji Hwa RYU ; Jae Ryang JUHN ; Choong Ki EUN
Journal of the Korean Radiological Society 1997;36(1):65-70
PURPOSE: Spirometric gating quantitative CT, PULMO-CT, is an objective method for the measurement of pulmonary parenchymal attenuation at a constant level of inspiration. In order to obtain a normal value for quantitative CT of the lung, the authors therefore used PULMO-CT to evalvate the lung density of healthy koreans with different respiratiory status. MATERIALS AND METHODS: Twenty healthy Korean volunteers, 18 men and 2 women, ranging in age from 24 to 27 years and with normal chest radiography, were evaluated using the PULMO-CT option of Somatom Plus(Siemens, Erlangen, Germany). Spirometric gating HRCT images, at levels of 50% and 20% of vital capacity, were obtained at the level of the tracheal carina and at 5cm above and below this point. The images were analyzed by semiautomatic programs and the results were evaluated using the Student t-test. RESULTS: The mean attenuation value of lung parenchyma at 50% of vital capacity was -791HU27.1 and at 20% was -700HU+/-42.9. The difference in lung attenuation was 91HU and was statistically significant(p<0.001). The for 58% of participants, the highest reading for of lung attenuation at 50% of vital capacity was between -899HU and -800HU, and for 20.3% of participants, this reading was between -799HU and -700HU. At 20% of vital capacity, the largest proportion of participants(43.8%) had a reading of between -799HU and -700HU; the reading of 35.2% was higher than -699HU. CONCLUSION: Respiratory status significantly affects the quantitative accessment of pulmonary parenchyma; in order to determine, during quantitative HRCT, the parameters of a pathologic condition, lung parenchyma of differing respiratory status must be evaluated.
Female
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Humans
;
Lung*
;
Male
;
Radiography
;
Reference Values
;
Thorax
;
Vital Capacity
;
Volunteers
10.Pelvic Lymph Node Metastases in Prostate Cancer: Preoperative Detection With Dynamic Contrast-Enhanced Magnetic Resonance Imaging Compared With Postoperative Pathologic Result of Pelvic Lymph Node Dissection.
Hoyoung RYU ; Byeongdo SONG ; Jinho HWANG ; Sung Kyu HONG ; Seok Soo BYUN ; Sang Eun LEE ; Sangchul LEE
Korean Journal of Urological Oncology 2017;15(3):158-164
PURPOSE: The aim of this study is evaluating the accuracy of preoperative magnetic resonance imaging (MRI) in patients who underwent pelvic lymph node dissection (PLND). MATERIALS AND METHODS: The medical records of 1,528 patients who underwent radical prostatectomy and PLND from 2003 to 2017 in Seoul National University Bundang Hospital were retrospectively reviewed. We evaluated the various clinicopathologic variables including preoperative MRI findings and pathologic lymph node (LN) metastasis. The prediction model for pathologic LN metastasis was assessed using univariate and multivariable logistic regression analyses and areas under receiver operating characteristic (ROC) curves. RESULTS: The mean age of our cohort was 66.4±6.7 years. Positive LN finding of preoperative MRI finding was observed in 9.4% (145 of 1,528) of patients. 5.3% (81 of 1,528) of patients had confirmed final pathologic LN metastases. Sensitivity and specificity of preoperative MRI were 30.8% and 91.7%, respectively. Multivariable analysis showed that preoperative MRI findings, clinical stage and biopsy Gleason score were independent significant predictors for pathologic LN metastasis (p < 0.001, p=0.002, and p < 0.001, respectively). Prediction model using preoperative MRI findings and National Comprehensive Control Network risk stratification showed fair accuracy using ROC analysis. CONCLUSIONS: Preoperative MRI findings for pathologic LN metastasis showed limited prediction value. A large-scale, multicenter, prospective study is needed to fully evaluate the clinical significance of preoperative MRI.
Biopsy
;
Cohort Studies
;
Humans
;
Logistic Models
;
Lymph Node Excision*
;
Lymph Nodes*
;
Magnetic Resonance Imaging*
;
Medical Records
;
Neoplasm Grading
;
Neoplasm Metastasis*
;
Prospective Studies
;
Prostate*
;
Prostatectomy
;
Prostatic Neoplasms*
;
Retrospective Studies
;
ROC Curve
;
Sensitivity and Specificity
;
Seoul