1.Comparison of Efficiency between Individual Randomization and Cluster Randomization in the Field Trial.
Hye Won KOO ; Min Jeong KWAK ; Youngjo LEE ; Byung Joo PARK
Korean Journal of Preventive Medicine 2000;33(1):51-55
OBJECTIVES: In large-scale field trials, randomization by cluster is frequently used because of the administrative convenience, a desire to reduce the effect of treatment contamination, and the need to avoid ethical issues that might otherwise arise. Cluster randomization trials are experiments in which intact social unit, e.g., families, schools, cities, rather than independent individuals are randomly allocated to intervention groups. The positive correlation among responses of subjects from the same cluster is in matter in cluster randomization. This thesis is to compare the results of three randomization methods by standard error of estimator of treatment effect. METHODS: We simulated cholesterol data varing the size of the cluster and the level of the correlation in clusters and analyzed the effect of cholesterol-lowering agent. RESULTS: In intra-cluster randomization the standard error of the estimator of treatment effect is smallest relative to that in inter-cluster randomization and that in individual randomization. CONCLUSIONS: Intra-cluster randomization is the most efficient in its standard error of estimator of treatment effect but other factor should be considered when selecting a specific randomization method.
Cholesterol
;
Ethics
;
Humans
;
Random Allocation*
2.A Study of Tubular Fluid Effects to Dysmorphic Urinary RBCs in Glomerular Hematuria.
Byung Min CHOI ; Hyun Joo KWAK ; Kee Hwan YOO ; Joo Won LEE ; Soon Kyum KIM
Journal of the Korean Pediatric Society 1996;39(4):512-521
PURPOSE: Urinary red blood cell morphology has been used to localize the site of hematuria in the urinary tract. But the pathologic mechanism for dysmorphic urinary red blood cells remains undefned. Our study was undertaken to investigate the mechanism of dysmorphic urinary RBCs in glomerular hematuria. We have attempted to reproduce in vitro the changes that occur in red cell morphology during passage through the renal tubule and to elucidate the role of urinary composition in determining morphology. METHODS: We examined a number of urinary samples under bright f eld microscopes with Wright's stain. 1) One drop of fresh venous blood was added to 1 ml experimental fluid, allowed to stand for 5 min and then assessed. The experimental fluids used were NaCl solutions in which the sodium concentration varied among 40 and 400mmol/L and similar saline solutions to which KCl(10, 50mmol/L), CaCl2(0.5, 2mmol/L), Urea(100, 400mmol/L) and pH(4, 8) had been added. We examined the RBC morphology in these solution. 2) In order to simulate passage of RBCs through the renal tubule, RBCs were initially suspended for 5 min in hypertonic solutions(NaCl 200mmol/L+Urea 70mmol/L+Urea 1000mmol/L). The RBCs were separated by centrifuging at 500rpm for 2 min in conical tubes, the supernatant was discarded and the RBCs washed and resuspended in a hypotonic solution(NaCl 60mmol/L) for 5 min. We added two urines(610mOsm/Kg H2O) to these solutions and then examined the RBCs morphology. RESULTS: The results were as follows; 1) Anisocytosis and hypochromia were found in NaCl 60mmol/L and 75mmol/L solutions and crenated RBC was found in Nacl 400mmol/L solution. But addition of potassium, calcium or urea and variation of the pH had no effect on red cell morphology. 2) when exposed to hypotonic solution, which simulated tubular condition(NaCl 60mmol/L), the RBCs became anisocytotic and hypochromic. These two features were particularly marked if cells were transferred to concentrated urine(610mOsm/kg H2O). CONCLUSIONS: It is evident that a hypotonic tubular condition is hostile for red cells and may be primarily responsible for hy0pochromia and anisocytosis of RBCs. Although two characteristic features of dysmorphism can be reproduced in vitro, a the bizarre deformity cannot be observed. Therefore passage of red cells through the hypotonic tubular segment alone does not account for the typical deformity. Because dilute urine specimens give a false impression by selective lysis of dysmorphic cells, concentrated urine is suitable for analysis of red cell morphology.
Calcium
;
Congenital Abnormalities
;
Erythrocytes
;
Hematuria*
;
Hydrogen-Ion Concentration
;
Potassium
;
Sodium
;
Urea
;
Urinary Tract
3.A Case of Q Wave Acute Myocardial Infarction in Patients with Myocardial Bridging Caused by Fibrous Band.
Sun Young KWAK ; Seung Chul PARK ; Young Min KIM ; Sung Koo KIM ; Kwang Hee LEE ; Min Su HYON ; Young Joo KWON ; Wook YOUM
Korean Circulation Journal 1998;28(12):2061-2065
Myocardial bridging is defined that short segments of coronary artery descend into the myocardium for a variable distance and each systolic contraction of these fibers can cause narrowing of the artery. Systolic narrow-ing may rarely be caused by connective tissue such as fibrous band. Myocardial ischemia, infarction and sudden death may be seen in some patients with myocardial bridging. Myocardial infarction in association with isolated myocardial bridges with systolic narrowing is uncommon. We report a case of Q wave myocardial infarction in a patient with angiographic systolic narrowing at the middle segment left anterior descending coronary artery which was caused by fibrous band.
Arteries
;
Connective Tissue
;
Coronary Vessels
;
Death, Sudden
;
Humans
;
Infarction
;
Myocardial Bridging*
;
Myocardial Infarction*
;
Myocardial Ischemia
;
Myocardium
4.A Case of Multiple Systemic Embolism Associatied with Left Atrial Free-Floating Ball Thrombus.
Young Min KIM ; Seung Chul PARK ; Sun Young KWAK ; Wan Sup KIM ; Sung Koo KIM ; Min Su HYON ; Young Joo KWON ; Dong Won KIM
Korean Circulation Journal 1998;28(11):1889-1893
Left atrial thrombus is frequently associated with rheumatic mitral valvular heart disease. Left atrial thrombus is usually attached to the atrial wall, but rarely it is freely floating in the cavity. In that case the patient may present with the symptoms of acute hemodynamic decompensation due to the so-called "hole-in-one" effect or multiple systemic embolism. We report a case of multiple systemic embolism associated with left atrial free-floating ball thrombus in mitral valvular heart disease.
Echocardiography
;
Embolism*
;
Heart Valve Diseases
;
Hemodynamics
;
Humans
;
Thrombosis*
5.Three Dimensional Spiral CT of the Tracheobronchial Tree: Determination of the Optimal Window Settings.
So Young SHIN ; Myung Kook KWAK ; Young Min KIM ; Kul Ho JUNG ; Hye Ran YOON ; In Joo CHEONG ; Chang Jun LEE
Journal of the Korean Radiological Society 1997;36(6):991-994
PURPOSE: To determine optimal window settings for measuring the inner diameter of the trachea and both mainbronchi by spiral CT. MATERIALS AND METHODS: Chest PA radiography and spiral CT scanning were performed in ten healthy adult volunteers. Three dimensional images were reconstructed (minimal threshold value : -1000HU ; maximal threshold value : from -200 to -900HU, of 50HU intervals) to measure the inner diameter of the trachea and both main bronchi. The results of 3D spiral CT were compared with those of chest radiography. RESULTS: The inner diameters of the trachea, right main bronchus, left main bronchus-I (1cm below the tracheal carina) and left mainbronchus-II (2cm below the tracheal carina) measured by chest radiograph and 3D spiral CT were not significantly different at maximal threshold values of -400 ~ -550HU, -450 ~ -550HU, -450 ~ -600HU and -500 ~ -600HU, respectively (p>0.05). The differences in the results of the two series were statistically significant at other threshold values however (p<0.05). CONCLUSION: We determined optimal window settings for measuring the inner diameter of the trachea and both main bronchi by spiral CT. The optimal maximal threshold values were somewhat different according to measured sites of the trachea and both main bronchi.
Adult
;
Bronchi
;
Humans
;
Radiography
;
Radiography, Thoracic
;
Thorax
;
Tomography, Spiral Computed*
;
Trachea
;
Volunteers
6.Monophosphoryl lipid A (MPL) upregulates major histocompatibility complex (MHC) class I expression by increasing interferon-gamma (IFN-gamma).
Chul Ho CHO ; Bong Kee LEE ; Seung Min KWAK ; Joo Deuk KIM
Yonsei Medical Journal 1999;40(1):20-25
Tumor immunity is primarily mediated by cells as CD8+ cytotoxic T lymphocytes (CTL) recognize tumor antigen by MHC class I molecules. But most tumors are associated with a decreased expression of MHC class I to escape the antitumor immunity of the host. Our previous data have demonstrated that MPL has an antitumor effect on metastatic lung cancer of B16 melanoma with enhancing cytotoxicity due to increase of IFN-gamma and IL-2, and decrease of IL-4, which indicates the stimulation of type 1 helper T cells (Th1). To determine the effects of MPL, IFN-gamma, TNF-alpha, and IL-1 alpha on MHC class I expression of B16 melanoma cells, we evaluated the expression of MHC class I molecules with treatments of MPL, IFN-gamma, TNF-alpha, and IL-1 alpha by flow cytometry. The supernatant of MPL-treated spleen cells in vitro upregulated the expression of MHC class I molecules of B16 melanoma cells compared to the control supernatant of spleen cells. The MHC class I expression of B16 melanoma cells treated with IFN-gamma, but not TNF-alpha or IL-1 alpha, increased in a time-dependent manner. In conclusion, MPL upregulated MHC class I expression of B16 melanoma cells by activating spleen cells via IFN-gamma. These data suggest that increased IFN-gamma by MPL is responsible for the upregulation of MHC class I expression to augment cytotoxicity. Therefore, we suggest that MPL could play an important role in immunotherapy.
Adjuvants, Immunologic/pharmacology*
;
Animal
;
Histocompatibility Antigens Class I/biosynthesis*
;
Interferon Type II/pharmacology
;
Interferon Type II/biosynthesis*
;
Lipid A/pharmacology
;
Lipid A/analogs & derivatives*
;
Mice
;
Mice, Inbred C57BL
;
Tumor Cells, Cultured
;
Up-Regulation (Physiology)
7.Comparison of Morphine and Remifentanil on the Duration of Weaning from Mechanical Ventilation.
Jae Myeong LEE ; Seong Heon LEE ; Sang Hyun KWAK ; Hyeon Hui KANG ; Sang Haak LEE ; Jae Min LIM ; Mi Ae JEONG ; Young Joo LEE ; Chae Man LIM
Korean Journal of Critical Care Medicine 2016;31(4):381-381
No abstract available.
Morphine*
;
Respiration, Artificial*
;
Weaning*
8.Congenital Bronchoesophageal Fistula Causing Only Chronic Cough: One case.
Myung Sun JOO ; Seung Min KWAK ; Chul Ho JO ; Yong Woon SHIN ; Sae Whan KIM
Tuberculosis and Respiratory Diseases 1996;43(5):812-817
There were so many causes of chronic coughing including postnasal drip, pneumonia, nasal polyp, asthma, interstinal lung disease etc. Congenital bronchoesophageal fistula was not usually thought as cause of chronic coughing. A 46-year-old female patient suffered from chronic coughing without usual causes. Her chest X-ray viewed normally. She coughed especially after swallowing foods. So we recommended her esophagogram and it revealed broncho-esphageal fistula. She underwent surgical resection of broncho-esophageal fistula. She was well without cough after the surgery. We reported a case of congenital broncho-esphageal fistula that had caused chronic coughing without any evidence of pneumonia, malignancy, tuberculosis, bronchiectasis, inflammation, asthma, nasal polyp, etc. So we should suspect the bronchoesophageal fistula when patients cough chronically with eating, and recommend the esophagogram.
Asthma
;
Bronchiectasis
;
Cough*
;
Deglutition
;
Eating
;
Female
;
Fistula*
;
Humans
;
Inflammation
;
Lung Diseases
;
Middle Aged
;
Nasal Polyps
;
Pneumonia
;
Thorax
;
Tuberculosis
9.TERT Promoter Mutations and Tumor Persistence/Recurrence in Papillary Thyroid Cancer.
Jae Kyung MYUNG ; Byung Kuk KWAK ; Jung Ah LIM ; Myung Chul LEE ; Min Joo KIM
Cancer Research and Treatment 2016;48(3):942-947
PURPOSE: A telomerase reverse transcriptase (TERT) promoter mutation was identified in thyroid cancer. This TERT promoter mutation is thought to be a prognostic molecular marker, because its association with tumor aggressiveness, persistence/recurrence, and disease-specific mortality in papillary thyroid carcinoma (PTC) has been reported. In this study, we attempted to determine whether the impact of the TERT promoter mutation on PTC persistence/recurrence is independent of clinicopathological parameters. MATERIALS AND METHODS: Using propensity score matching, 39 patients with PTC persistence or recurrence were matched with 35 patients without persistence or recurrence, with a similar age, sex, tumor size, multifocality, bilaterality, extrathyroidal extension, and lymph node metastasis. The TERT promoter and the BRAF V600E mutations were identified from PTC samples. RESULTS: The TERT promoter mutation was detected in 18% of PTC patients (13/74). No significant difference in the frequency of the TERT promoter mutation was observed between the persistence/recurrence group and the non-recurrence group. CONCLUSION: These results suggest that the prognostic implications of the TERT promoter mutation are dependent on clinicopathological parameters.
Humans
;
Lymph Nodes
;
Mortality
;
Neoplasm Metastasis
;
Propensity Score
;
Recurrence
;
Telomerase
;
Thyroid Gland*
;
Thyroid Neoplasms*
10.A Case of the Uterus Didelphys with Unilateral Obstructed Hemivagina.
Moon Hee YOUN ; Min Jung KWAK ; Ji Uen KIM ; Mun Geon JANG ; Seon Ha JOO ; Keon JIN
Korean Journal of Obstetrics and Gynecology 2004;47(8):1620-1624
Uterus didelphys with unilateral obstructed hemivagina is indeed a very rare congenital anomaly due to M llerian duct malformation. The most common clinical presentation is pelvic pain and dysmenorrhea shortly after menarche, in associated with the finding of a vaginal or pelvic mass. An accurate and prompt diagnosis is of importance to permit treatment and to assure the future fertility of the patient. The simple and adequate treatment of the condition is incision of the obstructed vaginal septum providing adequate drainage of the retained blood. We report a case of uterus didelphys with obstructed hemivagina with brief review of the literature.
Diagnosis
;
Drainage
;
Dysmenorrhea
;
Female
;
Fertility
;
Humans
;
Menarche
;
Pelvic Pain
;
Uterus*