1.mechanism of Cell Death induced by ZnCl2 and Calmodulin Antagonist in Human Retinoblastoma Cells.
Hui Joung JOUNG ; Young Hwan EUM ; Hwan Tae PARK ; Ill Han YUN
Journal of the Korean Ophthalmological Society 2000;41(12):2686-2698
No Abstract Available.
Calmodulin*
;
Cell Death*
;
Humans*
;
Retinoblastoma*
2.Computation of geographic variables for air pollution prediction models in South Korea.
Youngseob EUM ; Insang SONG ; Hwan Cheol KIM ; Jong Han LEEM ; Sun Young KIM
Environmental Health and Toxicology 2015;30(1):e2015010-
Recent cohort studies have relied on exposure prediction models to estimate individual-level air pollution concentrations because individual air pollution measurements are not available for cohort locations. For such prediction models, geographic variables related to pollution sources are important inputs. We demonstrated the computation process of geographic variables mostly recorded in 2010 at regulatory air pollution monitoring sites in South Korea. On the basis of previous studies, we finalized a list of 313 geographic variables related to air pollution sources in eight categories including traffic, demographic characteristics, land use, transportation facilities, physical geography, emissions, vegetation, and altitude. We then obtained data from different sources such as the Statistics Geographic Information Service and Korean Transport Database. After integrating all available data to a single database by matching coordinate systems and converting non-spatial data to spatial data, we computed geographic variables at 294 regulatory monitoring sites in South Korea. The data integration and variable computation were performed by using ArcGIS version 10.2 (ESRI Inc., Redlands, CA, USA). For traffic, we computed the distances to the nearest roads and the sums of road lengths within different sizes of circular buffers. In addition, we calculated the numbers of residents, households, housing buildings, companies, and employees within the buffers. The percentages of areas for different types of land use compared to total areas were calculated within the buffers. For transportation facilities and physical geography, we computed the distances to the closest public transportation depots and the boundary lines. The vegetation index and altitude were estimated at a given location by using satellite data. The summary statistics of geographic variables in Seoul across monitoring sites showed different patterns between urban background and urban roadside sites. This study provided practical knowledge on the computation process of geographic variables in South Korea, which will improve air pollution prediction models and contribute to subsequent health analyses.
Air Pollution*
;
Altitude
;
Buffers
;
Cohort Studies
;
Family Characteristics
;
Geographic Information Systems
;
Geography
;
Housing
;
Information Services
;
Korea*
;
Seoul
;
Transportation
3.Computation of geographic variables for air pollution prediction models in South Korea.
Youngseob EUM ; Insang SONG ; Hwan Cheol KIM ; Jong Han LEEM ; Sun Young KIM
Environmental Health and Toxicology 2015;30(1):e2015010-
Recent cohort studies have relied on exposure prediction models to estimate individual-level air pollution concentrations because individual air pollution measurements are not available for cohort locations. For such prediction models, geographic variables related to pollution sources are important inputs. We demonstrated the computation process of geographic variables mostly recorded in 2010 at regulatory air pollution monitoring sites in South Korea. On the basis of previous studies, we finalized a list of 313 geographic variables related to air pollution sources in eight categories including traffic, demographic characteristics, land use, transportation facilities, physical geography, emissions, vegetation, and altitude. We then obtained data from different sources such as the Statistics Geographic Information Service and Korean Transport Database. After integrating all available data to a single database by matching coordinate systems and converting non-spatial data to spatial data, we computed geographic variables at 294 regulatory monitoring sites in South Korea. The data integration and variable computation were performed by using ArcGIS version 10.2 (ESRI Inc., Redlands, CA, USA). For traffic, we computed the distances to the nearest roads and the sums of road lengths within different sizes of circular buffers. In addition, we calculated the numbers of residents, households, housing buildings, companies, and employees within the buffers. The percentages of areas for different types of land use compared to total areas were calculated within the buffers. For transportation facilities and physical geography, we computed the distances to the closest public transportation depots and the boundary lines. The vegetation index and altitude were estimated at a given location by using satellite data. The summary statistics of geographic variables in Seoul across monitoring sites showed different patterns between urban background and urban roadside sites. This study provided practical knowledge on the computation process of geographic variables in South Korea, which will improve air pollution prediction models and contribute to subsequent health analyses.
Air Pollution*
;
Altitude
;
Buffers
;
Cohort Studies
;
Family Characteristics
;
Geographic Information Systems
;
Geography
;
Housing
;
Information Services
;
Korea*
;
Seoul
;
Transportation
4.Assessment of inter- and intra-fractional volume of bladder and body contour by mega-voltage computed tomography in helical tomotherapy for pelvic malignancy
Sunghyun KIM ; Sei Hwan YOU ; Young Ju EUM
Radiation Oncology Journal 2018;36(3):235-240
PURPOSE: We describe the daily bladder volume change observed by mega-voltage computed tomography (MVCT) during pelvic radiotherapy with potential predictors of increased bladder volume variations. MATERIALS AND METHODS: For 41 patients who received pelvic area irradiation, the volumes of bladder and pelvic body contour were measured twice a day with pre- and post-irradiation MVCT from the 1st to the 10th fraction. The median prescription dose was 20 Gy (range, 18 to 30 Gy) up to a 10th fraction. The upper and lower margin of MVCT scanning was consistent during the daily treatments. The median age was 69 years (range, 33 to 86 years) and 10 patients (24.4%) were treated postoperatively. RESULTS: Overall bladder volume on planning computed tomography was 139.7 ± 92.8 mL. Generally, post-irradiation bladder volume (POSTBV) was larger than pre-irradiation bladder volume (PREBV) (p < 0.001). The mean PREBV and POSTBV was reduced after 10 fraction treatments by 21.3% (p = 0.028) and 25.4% (p = 0.007), respectively. The MVCT-scanned body contour volumes had a tendency to decrease as the treatment sessions progressed (p = 0.043 at the 8th fraction and p = 0.044 at the 10th fraction). There was a statistically significant correlation between bladder filling time and PREBV (p = 0.001). CONCLUSION: Daily MVCT-based bladder volume assessment was feasible both intra- and inter-fractionally.
Humans
;
Pelvic Neoplasms
;
Prescriptions
;
Radiotherapy
;
Radiotherapy, Intensity-Modulated
;
Urinary Bladder
5.Two Cases of Gastric Mucosal Calcinosis.
Ju Chun YEO ; Dong Uk JU ; Se Young LEE ; Sung Woo EUM ; Jai Hyun LEE ; Se Hwan KIM ; Chang Keun PARK ; Seung Yup LEE ; Hyun Soo KIM ; Mi Jin KOO
Korean Journal of Gastrointestinal Endoscopy 2006;33(4):230-234
Gastric mucosal calcinosis (GMC) is a very rare condition that is characterized by the nodular deposition of calcium salts in the gastric mucosa. It has been associated with renal failure, gastric cancer, ingestion of aluminum- containing antacids and the use of sucralfate in organ transplant patients. The etiology of this condition is uncertain, but several theories have been proposed; the condition is due secondarily to hyperparathyroidism in renal failure and to the alkalinization of the gastric mucosa. We report here on two patients who had long-term use of bismuth and/or aluminum-containing antacids to treat their gastro-esophageal reflux symptoms. The esophagogastroduodenoscopy revealed acute gastritis patterns, and GMC was confirmed histologically with biopsy. When one patient stopped ingesting bismuth-containing antacid solution, the follow-up esophagogastroduodenoscopy and the biopsy revealed a completely improved state. We report here on these interesting cases and we include a brief review of the literature.
Antacids
;
Biopsy
;
Bismuth
;
Calcinosis*
;
Calcium
;
Eating
;
Endoscopy, Digestive System
;
Follow-Up Studies
;
Gastric Mucosa
;
Gastritis
;
Gastroesophageal Reflux
;
Humans
;
Hyperparathyroidism
;
Renal Insufficiency
;
Salts
;
Stomach Neoplasms
;
Sucralfate
;
Transplants
6.A Case of Melanosis Ilei.
Ji Hwan YOON ; Sung Hyeon EUM ; Sang Yup KIM ; Cheul Yeon KIM ; Hong Seok HWANG ; Hyung Hwa LEE ; Ji Young SEO ; Yeong Sung KIM ; Dong Hyup KWAK
Korean Journal of Gastrointestinal Endoscopy 2007;34(4):223-226
Melanosis ilei is a condition that's characterized by gross greyish-black or brownish-black pigmentation of the mucosa of the terminal ileum. There were several substances that produce gastrointestinal tract pigmentation such as lipofuscin, iron sulphide (FeS), Hemosiderin and exogenous material such as silicates and titanium. We report here on a case of a 58-year-old female who ingested charcoal for a long time, and she was diagnosed with melanosis ilei by colonoscopy. Her condition improved after she stopped ingesting the charcoal.
Charcoal
;
Colonoscopy
;
Female
;
Gastrointestinal Tract
;
Hemosiderin
;
Humans
;
Ileum
;
Iron
;
Lipofuscin
;
Melanosis*
;
Middle Aged
;
Mucous Membrane
;
Pigmentation
;
Silicates
;
Titanium
7.Feasibility of artificial intelligence-driven interfractional monitoring of organ changes by mega-voltage computed tomography in intensity-modulated radiotherapy of prostate cancer
Yohan LEE ; Hyun Joon CHOI ; Hyemi KIM ; Sunghyun KIM ; Mi Sun KIM ; Hyejung CHA ; Young Ju EUM ; Hyosung CHO ; Jeong Eun PARK ; Sei Hwan YOU
Radiation Oncology Journal 2023;41(3):186-198
Purpose:
High-dose radiotherapy (RT) for localized prostate cancer requires careful consideration of target position changes and adjacent organs-at-risk (OARs), such as the rectum and bladder. Therefore, daily monitoring of target position and OAR changes is crucial in minimizing interfractional dosimetric uncertainties. For efficient monitoring of the internal condition of patients, we assessed the feasibility of an auto-segmentation of OARs on the daily acquired images, such as megavoltage computed tomography (MVCT), via a commercial artificial intelligence (AI)-based solution in this study.
Materials and Methods:
We collected MVCT images weekly during the entire course of RT for 100 prostate cancer patients treated with the helical TomoTherapy system. Based on the manually contoured body outline, the bladder including prostate area, and rectal balloon regions for the 100 MVCT images, we trained the commercially available fully convolutional (FC)-DenseNet model and tested its auto-contouring performance.
Results:
Based on the optimally determined hyperparameters, the FC-DenseNet model successfully auto-contoured all regions of interest showing high dice similarity coefficient (DSC) over 0.8 and a small mean surface distance (MSD) within 1.43 mm in reference to the manually contoured data. With this well-trained AI model, we have efficiently monitored the patient's internal condition through six MVCT scans, analyzing DSC, MSD, centroid, and volume differences.
Conclusion
We have verified the feasibility of utilizing a commercial AI-based model for auto-segmentation with low-quality daily MVCT images. In the future, we will establish a fast and accurate auto-segmentation and internal organ monitoring system for efficiently determining the time for adaptive replanning.
8.Prevalence and Clinical Characteristics of Noncardiac Chest Pain with Reflux Esophagitis in Korea.
Ji Young MOK ; Sohyun KWON ; Kiwon SHIN ; Seonwoo OH ; Soojeong HAN ; Sang Hoon EUM ; Hee Jun KANG ; Bong Han KONG ; Byung Hee HWANG ; Jung Hwan OH
The Korean Journal of Helicobacter and Upper Gastrointestinal Research 2016;16(2):88-91
BACKGROUND/AIMS: Noncardiac chest pain (NCCP) is substernal, squeezing chest pain, unrelated to the cardiac problem. Our study aimed to define the prevalence and clinical characteristics of reflux esophagitis in NCCP patients in Korea. MATERIALS AND METHODS: We reviewed medical records of patients who visited Department of Cardiology, St. Paul's Hospital due to chest pain and had normal coronary arteriography and who had received endoscopy within 6 months. Patients diagnosed with peptic ulcer or gastric cancer were excluded. The patients were classified into two groups according to their endoscopic results; the reflux esophagitis group and the control group. RESULTS: Two hundred seventeen NCCP patients were enrolled and 96 patients (44.2%) were diagnosed with reflux esophagitis: 68 patients (31.3%) with minimal change esophagitis; 26 patients (12.0%) with Los Angeles (LA) grade A; 2 patients (0.9%) with LA grade B. There were no patients with severe erosive reflux disease. There were no significantly different characteristics in the reflux esophagitis group and the control group. CONCLUSIONS: The prevalence of reflux esophagitis in NCCP patients in Korea was 44.2%. Most patients had mild reflux esophagitis.
Angiography
;
Cardiology
;
Chest Pain*
;
Endoscopy
;
Esophagitis
;
Esophagitis, Peptic*
;
Gastroesophageal Reflux
;
Humans
;
Korea*
;
Medical Records
;
Peptic Ulcer
;
Prevalence*
;
Stomach Neoplasms
;
Thorax*
9.Endoscopic Bilateral Metal Stent Placement with a Y-Configured Dual Stent for Advanced Hilar Carcinoma.
Jong Ho HWANG ; Dae Hwan KANG ; Sang Yong LEE ; Kyung Yeob KIM ; Jae Sup EUM ; Ji Young KIM ; Do Hoon KIM ; Gwang Ha KIM ; Jeong HEO ; Geun Am SONG ; Mong CHO
Korean Journal of Gastrointestinal Endoscopy 2008;36(1):7-13
BACKGROUND/AIMS: Palliative endoscopic or percutaneous internal drainage is widely used for treating hilar cholangiocarcinoma. Yet unilateral biliary drainage does not completely improve jaundice and it can induce acute cholangitis by the undrained contrast media. To investigate this technique's technical and clinical effectiveness, a newly devised Y-configured dual stent was used for treating advanced hilar malignancies. METHODS: From May, 2005 to May, 2007, 20 hilar malignancies (men: women=9:11, age=70.5 yr) that were not suitable for surgical resection were included in this study. For bilateral metal stent placement, a biliary stent with a wide open central mesh was first inserted. After this, another stent without a hole was inserted into the contralateral hepatic duct through the open central mesh of the first stent. RESULTS: Bilateral metal stent insertion was done in 14 of 20 patients. Among the 14 patients in whom bilateral stents were successfully placed, the rate of functional success was 100%. There were no early complications. As a late complication, stent occlusion occurred in 4 of 14 patients (28.5%), and one of these patients had a plastic stent inserted. The other 3 patients were treated with percutaneous transhepatic biliary drainage. The median stent patency period was 231 days. CONCLUSION: The bilateral metal stent method using the Y stent is safe and effective for bilateral biliary drainage in patients with unresectable hilar malignancies.
Cholangiocarcinoma
;
Cholangitis
;
Contrast Media
;
Drainage
;
Hepatic Duct, Common
;
Humans
;
Jaundice
;
Plastics
;
Stents
10.Uncovered Self-expandable Metal Stents (SEMS) for Gastric Outlet Obstruction Caused by Stomach Cancer.
Hyoung Yoel PARK ; Dae Hwan KANG ; Jae Sup EUM ; Tae In HA ; Chan Ho PARK ; Kyung Yeob KIM ; Cheol Woong CHOI ; Do Hoon KIM ; Ji Young KIM ; Hye Jeong LEE ; Gwang Ha KIM ; Geun Am SONG
Korean Journal of Gastrointestinal Endoscopy 2008;36(2):57-63
BACKGROUND/AIMS: The use of self-expandable metal stents (SEMS) is a safe and efficacious method for palliating malignant gastric outlet obstruction. However, few reports have assessed clinical outcome after the insertion of SEMS for malignant gastric outlet obstruction caused by stomach cancer. The aim of this study was to assess the usefulness of uncovered SEMS in patients with malignant gastric outlet obstruction caused by stomach cancer. METHODS: We evaluated 62 patients with gastric outlet obstruction caused by stomach cancer treated by the implantation of uncovered SEMS. A total of 62 patients (43 males, 19 females) were treated between August 2000 and March 2007. A scoring system was used to grade the ability to eat. RESULTS: Stent implantation was successful in 61 (98.4%) patients. Relief of obstructive symptoms was achieved in 49 (80.3%) patients. The mean survival duration was 143 days. The mean stent patency time was 103.5 days. An improvement in the ability to eat using the scoring system was statistically significant (p<0.05). CONCLUSIONS: Endoscopic placement of uncovered SEMS is a safe and effective treatment for the palliation of patients with inoperable malignant gastric outlet obstruction caused by stomach cancer.
Gastric Outlet Obstruction
;
Humans
;
Male
;
Stents
;
Stomach
;
Stomach Neoplasms