1.The Korea Cohort Consortium: The Future of Pooling Cohort Studies
Sangjun LEE ; Kwang-Pil KO ; Jung Eun LEE ; Inah KIM ; Sun Ha JEE ; Aesun SHIN ; Sun-Seog KWEON ; Min-Ho SHIN ; Sangmin PARK ; Seungho RYU ; Sun Young YANG ; Seung Ho CHOI ; Jeongseon KIM ; Sang-Wook YI ; Daehee KANG ; Keun-Young YOO ; Sue K. PARK
Journal of Preventive Medicine and Public Health 2022;55(5):464-474
Objectives:
We introduced the cohort studies included in the Korean Cohort Consortium (KCC), focusing on large-scale cohort studies established in Korea with a prolonged follow-up period. Moreover, we also provided projections of the follow-up and estimates of the sample size that would be necessary for big-data analyses based on pooling established cohort studies, including population-based genomic studies.
Methods:
We mainly focused on the characteristics of individual cohort studies from the KCC. We developed “PROFAN”, a Shiny application for projecting the follow-up period to achieve a certain number of cases when pooling established cohort studies. As examples, we projected the follow-up periods for 5000 cases of gastric cancer, 2500 cases of prostate and breast cancer, and 500 cases of non-Hodgkin lymphoma. The sample sizes for sequencing-based analyses based on a 1:1 case-control study were also calculated.
Results:
The KCC consisted of 8 individual cohort studies, of which 3 were community-based and 5 were health screening-based cohorts. The population-based cohort studies were mainly organized by Korean government agencies and research institutes. The projected follow-up period was at least 10 years to achieve 5000 cases based on a cohort of 0.5 million participants. The mean of the minimum to maximum sample sizes for performing sequencing analyses was 5917-72 102.
Conclusions
We propose an approach to establish a large-scale consortium based on the standardization and harmonization of existing cohort studies to obtain adequate statistical power with a sufficient sample size to analyze high-risk groups or rare cancer subtypes.
2.Is It Worth Treating Non-Bothering Nocturia? Results of a Multicenter Prospective Observational Study.
Kwangsung PARK ; Hyoung Keun PARK ; Sae Woong KIM ; Dae Yul YANG ; Jong Kwan PARK ; Hyun Jun PARK ; Ki Hak MOON ; Du Geon MOON ; Kweon Sik MIN ; Hwancheol SON ; Sung Won LEE ; Jae Seog HYUN ; Woo Suk CHOI ; Sang Kuk YANG
The World Journal of Men's Health 2018;36(3):248-254
PURPOSE: The purpose of this study was to evaluate the efficacy of treatment in patients with non-bothering nocturia. MATERIALS AND METHODS: In this prospective multicenter study, patients who visited hospitals for treatment of voiding symptoms were enrolled. Inclusion criteria were: 1) men >45 years, and 2) nocturia ≥2 confirmed by a three-day voiding diary. Subjects were divided into non-bothering and bothering groups based on International Consultation on Incontinence Questionnaire Nocturia (ICIQ-N) question 2b. Changes in voiding symptoms, frequency of nocturia, and bothersomeness were evaluated with international prostate symptom score (IPSS), ICIQ-N, and three-day voiding diary at 4 and 12 weeks after treatment. RESULTS: A total of 48 patients in the non-bothering nocturia group and 50 patients in the bothering nocturia group who completed the 12-week treatment were analyzed. The total IPSS was decreased by 5.8 in the non-bothering group and 5.2 in the bothering group. There was no significant difference in decrease of IPSS between the two groups. Both groups showed significant reduction in discomfort of nocturia. The ICIQ-N 2b score decreased from 3.9 to 2.7 (p=0.01) in the non-bothering group and from 6.9 to 4.6 (p=0.02) in the bothering group. The number of nocturia episodes was significantly decreased in both groups. CONCLUSIONS: Regardless of discomfort associated with nocturia, both groups showed significant improvement in nocturia-related discomfort and voiding symptoms. These results suggest that patients with nocturia who were unaware of its discomfort benefited from treatment.
Humans
;
Lower Urinary Tract Symptoms
;
Male
;
Nocturia*
;
Observational Study*
;
Prospective Studies*
;
Prostate
;
Prostatic Hyperplasia
3.Comparison and Investigation of the National Standards for Tinted Contact Lenses between Various Countries.
Sang Ah KIM ; Ji Won JUNG ; Kyoung Yul SEO ; Hyung Keun LEE ; Eung Kweon KIM ; Tae Im KIM
Journal of the Korean Ophthalmological Society 2015;56(11):1692-1698
PURPOSE: In this study we investigated the safety level of the national standard for tinted soft contact lenses by comparing the standards in various countries. METHODS: To evaluate the current guidelines for tinted soft contact lenses such as form and appearance, diameter, curvature radius, vertex power, cylindrical refractivity and cylindrical axis, luminous/ultraviolet ray (UV) transmittance, moisture content, oxygen permeability coefficient, extractables, elution test, cytotoxicity, sensitization, eye irritation test, acute systemic/subchronic/subacute toxicity, genotoxicity and biocompatibility safety test using rabbit eyes and sterility test. We compared the standards of International Organization for Standardization (ISO), Food and Drug Administration (FDA) of the United States, Ministry of Health, Labor and Welfare (MHLW) of Japan and Ministry of Food and Drug Safety (MFDS) of Korea. RESULTS: The guidelines for tinted soft contact lenses of ISO, FDA and MFDS are similar to soft contact lenses but MHLW of Japan classifies these lenses and sets specific guidelines. First, the oxygen permeability coefficient measured at 6mm from the center should be maintained over 80%. Also, coloring should not affect the oxygen permeability coefficient significantly. Regarding the physical (form and appearance, diameter, curvature radius, moisture content) and optical (vertex power, cylindrical refractivity and cylindrical axis, luminous/UV transmittance, oxygen permeability coefficient) characteristics, no differences were found between ISO and MFDS. However, several differences were found in chemical characteristics (extractables, elution test) and biological stability (cytotoxicity, sensitization, eye irritation test, acute systemic/subchronic/subacute toxicity test, genotoxicity, biocompatibility safety test using rabbit eyes, sterility test). For example, the elution test is required only by MFDS. CONCLUSIONS: The reinvestigation into the effectiveness of the elution test is needed and new evaluation measures including scanning electron microscopy and atomic force microscopy designed for tinted soft contact lenses to evaluate the size of the optical area, the location and roughness of the pigmented layer are required.
Axis, Cervical Vertebra
;
Contact Lenses*
;
Contact Lenses, Hydrophilic
;
Infertility
;
Japan
;
Korea
;
Microscopy, Atomic Force
;
Microscopy, Electron, Scanning
;
Oxygen
;
Permeability
;
Radius
;
Toxicity Tests
;
United States
;
United States Food and Drug Administration
4.Effect of Cyclosporin A on Tear Film and Corneal Aberration after Cataract Surgery.
Jei Hun JEON ; Hong Seok KIM ; Ji Won JUNG ; Sang Chul YOON ; Kyoung Yul SEO ; Hyung Keun LEE ; Eung Kweon KIM ; Tae Im KIM
Journal of the Korean Ophthalmological Society 2014;55(7):978-983
PURPOSE: To evaluate the efficacy of 0.05% cyclosporine A on tear film parameters and corneal aberration after cataract surgery. METHODS: Patients who underwent cataract surgery were divided into 2 groups. Patients in Group I (23 eyes) were treated with cyclosporine A from 1 week before surgery to 3 months after surgery. Patients in Group II (24 eyes) underwent surgery without cyclosporine treatment. Tear film break-up time (BUT), Schirmer's test I, Oxford scheme, Ocular surface disease index (OSDI), and corneal aberrations were evaluated before surgery and at 1 and 3 months after surgery. RESULTS: In Group I, BUT was significantly improved at 3 months (p = 0.026) after surgery compared with the preoperative value. OSDI decreased significantly at 1 (p = 0.033) and 3 months (p = 0.003) after surgery compared with the preoperative value. However, there were no significant differences between preoperative and postoperative values of BUT and OSDI in Group II. Schirmer's test results and the Oxford scheme were not significantly changed in either group. Preoperative root mean square (RMS) total values were not different between the 2 groups, but was different at postoperative 3 months (p = 0.015). Group I had a significantly lower value for total RMS than Group II. In Group I, Coma 7 (Z3(-1)) (p = 0.018) and spherical aberration (Z4(0)) (p = 0.031) were significantly decreased after surgery. In Group II, Trefoil 6 (Z3(-3)) (p = 0.033) was significantly increased after surgery. CONCLUSIONS: 0.05% cyclosporine A may be effective for improving dry eye syndrome and corneal aberration after cataract surgery.
Cataract*
;
Coma
;
Cyclosporine*
;
Dry Eye Syndromes
;
Humans
;
Lotus
;
Tears*
5.A case of hemocholecyst associated with hemobilia following radiofrequency ablation therapy for hepatocellular carcinoma.
Keun Young SHIN ; Jun HEO ; Ji Yeon KIM ; Sang Jik LEE ; Se Young JANG ; Soo Young PARK ; Min Kyu JUNG ; Chang Min CHO ; Won Young TAK ; Young Oh KWEON
The Korean Journal of Hepatology 2011;17(2):148-151
Radiofrequency ablation (RFA) is performed as an alternative to surgical resection for primary or secondary liver malignancies. Although RFA can be performed safely in most patients, early and late complications related to mechanical or thermal damage occur in 8-9.5% cases. Hemocholecyst, which refers to hemorrhage of the gallbladder, has been reported with primary gallbladder disease or as a secondary event associated with hemobilia. Hemobilia, defined as hemorrhage in the biliary tract and most commonly associated with accidental or iatrogenic trauma, is a rare complication of RFA. Here we report a case of hemocholecyst associated with hemobilia after RFA for hepatocellular carcinoma that was successfully managed by laparoscopic cholecystectomy.
Aged
;
Carcinoma, Hepatocellular/*surgery
;
Catheter Ablation/*adverse effects
;
Cholangiopancreatography, Endoscopic Retrograde
;
Cholecystectomy
;
Gallbladder Diseases/*etiology/surgery/ultrasonography
;
Hemobilia/diagnosis/*etiology/surgery
;
Hemorrhage/*etiology
;
Humans
;
Liver Neoplasms/*surgery
;
Male
;
Tomography, X-Ray Computed
6.Solitary Pulmonary Nodule on Helical Dynamic CT Scans: Analysis of the Enhancement Patterns Using a Computer-Aided Diagnosis (CAD) System.
Eun Jung CHOI ; Gong Yong JIN ; Young Min HAN ; Young Sun LEE ; Keun Sang KWEON
Korean Journal of Radiology 2008;9(5):401-408
OBJECTIVE: We wanted to investigate the usefulness of a computer-aided diagnosis (CAD) system in assisting radiologists to diagnosis malignant solitary pulmonary nodules (SPNs), as compared with diagnosing SPNs with using direct personal drawing. MATERIALS AND METHODS: Forty patients with SPNs were analyzed. After the pre-contrast scan was performed, an additional ten series of post-contrast images were obtained at 20-second intervals. Two investigators measured the attenuation values of the SPNs: a radiologist who drew the regions of interest (ROIs), and a technician who used a CAD system. The Bland and Altman plots were used to compare the net enhancement between a CAD system and direct personal drawing. The diagnostic characteristics of the malignant SPNs were calculated by considering the CAD and direct personal drawing and with using Fisher's exact test. RESULTS: On the Bland and Altman plot, the net enhancement difference between the CAD system and direct personal drawing was not significant (within +/- 2 standard deriation). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of diagnosing malignant SPNs using CAD was 92%, 85%, 75%, 96% and 88%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of diagnosing malignant SPNs using direct drawing was 92%, 89%, 79%, 92% and 88%, respectively. CONCLUSION: The CAD system was a useful tool for diagnosing malignant SPNs.
Adult
;
Aged
;
Contrast Media
;
Diagnosis, Computer-Assisted/*methods
;
Diagnosis, Differential
;
Female
;
Humans
;
Iohexol/analogs & derivatives/diagnostic use
;
Lung Neoplasms/*radiography
;
Male
;
Middle Aged
;
Predictive Value of Tests
;
Radiographic Image Enhancement/*methods
;
Retrospective Studies
;
Sensitivity and Specificity
;
Solitary Pulmonary Nodule/*radiography
;
Tomography, Spiral Computed/*methods
7.The Anti-inflammatory Effect of Rosiglitazone on Renal Injury in Sepsis Model.
Kyung Joo JEON ; Yeon Kweon JEON ; Jong Hyun KIM ; Yong Bum JANG ; Kyu Yun JANG ; Myoung Jae KANG ; Keun Sang KWON ; Sik LEE
Korean Journal of Nephrology 2005;24(4):526-536
BACKGROUND: Agonists of the peroxisome proliferator-activated receptor gamma may help to regulate inflammation by modulating the production of inflammatory mediators and adhesion molecules. The purpose of this study was to determine the anti- inflammatory effects of rosiglitazone on renal injury in sepsis model. METHODS: In lipopolysaccharide (LPS)-induced mouse sepsis, we examined the effect of rosiglitazone on LPS-induced overproduction of inflammatory mediators, on the expression of adhesion molecules, on the infiltration of inflammatory cells and on renal function. RESULTS: Rosiglitazone significantly decreased serum tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta levels during sepsis. The levels of blood urea nitrogen and creatinine were significantly lower in mice pretreated with rosiglitazone than that in LPS-treated mice. Rosiglitazone reduced the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in renal tissue of LPS-treated mice. Pretreatment with rosiglitazone reduced the infiltration of macrophages/ monocytes in renal tissue. CONCLUSION: These results indicate that pretreatment with rosiglitazone attenuated the production of TNF-alpha and IL-1beta and reduced adhesion molecule expression and infiltration of inflammatory cells in renal tissue of LPS-treated mice. Therefore, rosiglitazone may have a protective effect in maintaining renal function and reducing mortality and morbidity in sepsis.
Animals
;
Blood Urea Nitrogen
;
Creatinine
;
Inflammation
;
Intercellular Adhesion Molecule-1
;
Interleukins
;
Mice
;
Monocytes
;
Mortality
;
PPAR gamma
;
Sepsis*
;
Tumor Necrosis Factor-alpha
;
Vascular Cell Adhesion Molecule-1
8.Comparison of Central Corneal Thickness after the Instillation of Topical Anesthetics: Proparacaine versus Oxybuprocaine.
Kyoung Sub CHOI ; Sang Min NAM ; Hyung Keun LEE ; Eung Kweon KIM ; Kyoung Yul SEO
Journal of the Korean Ophthalmological Society 2005;46(5):757-762
PURPOSE: To compare changes in human central corneal thickness after instillation of proparacaine with those after oxybuprocaine instillation, over a period of 10 minutes. METHODS: Eighteen healthy young participants were recruited. Baseline central corneal thicknesses were measured every 30 seconds for 10 minutes using a noncontact specular microscope. Changes in central corneal thickness were measured every 20 seconds for 10 minutes after the administration of one drop of 0.5% proparacaine into the right eye, and one drop of 0.4% oxybuprocaine into the left eye. RESULTS: Mean baseline central corneal thickness was 531 +/- 45 micrometer in the right eye and 531 +/- 42 micrometer in the left. The central corneal thickness after proparacaine instillation increased to 8.6 micrometer (4.5-12.6 micrometer, 95% CI) and then returned to baseline within 80 seconds. Central corneal thickness after oxybuprocaine instillation increased to 7.7 micrometer (3.6-11.2 micrometer, 95% CI) and then returned to baseline within 80 seconds. There was a second transient increase about 5 minute after proparacaine instillation but no additional transient increase after oxybuprocaine instillation. CONCLUSIONS: The severity of oxybuprocaine's effect on central corneal thickness is similar to that of proparacaine. Central corneal thickness instability may occur for 5 minutes after proparacaine administration. Therefore, changes in central corneal thickness after topical anesthetics instillation should be considered when measuring central corneal thickness.
Anesthetics*
;
Humans
9.Clinical Analysis of the Patients with Choledochal Cyst: A Comparison between Children and Adults.
Seong LEE ; Il Young PARK ; Sang Kweon LEE ; Keun Ho LEE ; Young Kyung YOO ; Dong Goo KIM ; Eung Kook KIM ; Seung Nam KIM
Korean Journal of Hepato-Biliary-Pancreatic Surgery 2002;6(2):145-150
BACKGROUN/AIMS: We performed this study to review and compare the clinical characteristics of choledochal cyst between children and adults. METHODS: We reviewed medical records of patients with choldochal cyst who underwent surgical treatment between January 1984 and December 1996. We analyzed clinical symptoms, laboratory data and procedures. To compare clinical characteristics, patients under age 15 were grouped as children and the others were as adults. RESULTS: Sixty-eight patients, 21 children and 47 adults, underwent surgical treatment, Female predominance is common in both group. Abdominal pain was the most frequent symptom in both groups. Abdominal mass and jaundice were observed more frquently in children. Fever and chilling is more common in adults. The combined disease were more common in adults. Two adult patients had combined malignant diseases, cholangiocarcinoma and pancreas adenocarcinoma respectively. According to Todani's classsification, the most common type was type I in both group. The most common surgical procedure is cyst excision and hepaticojejunostomy in both groups. CONCLUSION: There was no significant difference in choledochal cysts between child and adults clinically. But combined diseases were common in adults, early detection and early surgry will be needed in this disease.
Abdominal Pain
;
Adenocarcinoma
;
Adult*
;
Child*
;
Cholangiocarcinoma
;
Choledochal Cyst*
;
Female
;
Fever
;
Humans
;
Jaundice
;
Medical Records
;
Pancreas
10.Intraperitoneal Hemorrhage Due to Spontaneous Rupture of Hepatocellular Carcinoma: Comparisons of Tranarterial Oily Chemoembolization and Simple Embolization with Gelfoam.
Jeong Min LEE ; Young Min HAN ; Young Soo YM ; Seong Hee YM ; Keun Sang KWEON
Journal of the Korean Radiological Society 2000;43(2):171-177
PURPOSE: To compare the safety and effectiveness of transarterial oily chemoembolization (TOCE) and transar-terial embolization (TAE) with Gelfoam in cases of ruptured hepatocellular carcinoma (HCC), and to describe the most important prognostic factors involved in emergency embolization. MATERIALS AND METHODS: Forty-two consecutive patients with spontaneously ruptured HCC underwent emergency TOCE (n = 22) or TGE (n = 20). In the TOCE group, Lipiodol (3 -10 cc), Adriamycin (20 -50 mg), and Mitomycin (2 -10 mg) were used, and these were followed by blockade of the hepatic arterial flow with gelatin sponge particles. In the TAE group, patients underwent only Gelfoam embolization. Using the Kaplan-Meier method, survival time from the time of embolization was estimated, and to analyze prognostic factors, Cox 's proportional hazard regression model was used. RESULTS: Successful hemostasis was achieved in 41 patients (97.6%). Mean survival time was 201 and 246 days in the TOCE and TAE group, respectively, but the difference was not tatistically significant (p > 0.05). Five of the TOCE group (22.7%) and three of the TAE group (15.0%) died of hepatic failure. Analysis of the prognostic factors showed that portal vein involvement by the tumor was the most important factor influencing survival. CONCLUSION: Although TOCE and TAE effectively controlled hemorrhaging from a ruptured HCC, the procedures involve a high risk of hepatic failure. Their goal should, therefore, be solely to achieve hemostasis, and thus decrease parenchymal injury.
Carcinoma, Hepatocellular*
;
Doxorubicin
;
Emergencies
;
Ethiodized Oil
;
Gelatin
;
Gelatin Sponge, Absorbable*
;
Hemorrhage*
;
Hemostasis
;
Humans
;
Liver Failure
;
Mitomycin
;
Porifera
;
Portal Vein
;
Rupture, Spontaneous*
;
Survival Rate

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