1.An experimental study about efficacy of drain catheters.
Bum Gyu AHN ; Joon Young NHO ; Hyo Cheol WOO ; Woo Cheol HWANG ; Choong Ki PARK ; Jong Sup YOON
Journal of the Korean Radiological Society 1993;29(5):917-922
Although percutaneous abscess drainage has become and accepted alternative from of therapy for selected patients with abscess, it is well known that there are several factors in the failure of adequate drainage such as pre-and post- procedural management, technique itself, various features of abscess, and selection and application of catheters. Among these factors, we made an experiment about drain efficacy of commonly used various catheters with different viscosities of water-glycerin solution under the two different pressure gradients. The experimental values of flow rate were lower than than the calculated values. An efficacy of experimental value was 4-14%. Because the inner diameter of fittings and stopcocks was usually smaller than the inner diameter of catheters, these factors also affected the drain efficacy. Finally, we though that it will be very helpful to the treatment of patients as well as to study about the catheter drainage, if the drain efficacy of individual catheters has been notified.
Abscess
;
Catheters*
;
Drainage
;
Humans
;
Viscosity
2.Malignant Schwannomas in children.
Joon Jai KIM ; Dong Joo SHIN ; Dong Won SON ; Hong Hoe KOO ; In Sang JEON ; Hee Young SHIN ; Hyo Seop AHN
Journal of the Korean Pediatric Society 1991;34(4):525-531
No abstract available.
Child*
;
Humans
;
Neurilemmoma*
;
Neurofibromatosis 1
3.Surface roughness and surface free energy components of various orthodontic adhesives.
Hyo Beom AHN ; Sug Joon AHN ; Dong Seok NAHM
Korean Journal of Orthodontics 2006;36(5):360-368
OBJECTIVE: Surface characteristics of dental materials play an important role in bacterial adhesion. The purpose of this study was to investigate surface characteristics of 5 different light-cured orthodontic adhesives (1 fluoride-releasing composite, 3 non-fluoride-releasing composites, and 1 resin-modified glass ionomer). METHODS: Surface roughness was measured using a confocal laser scanning microscope. Contact angle and surface free energy components were analyzed using the sessile drop method. RESULTS: Surface roughness was significantly different between adhesives despite a relatively small variation (less than 0.05 micrometer). Lightbond and Monolok2 were rougher than Enlight and Transbond XT. There were also significant differences in contact angles and surface free energy components between adhesives. In particular, considerable differences in contact angles and surface free energy components were found between resin modified glass ionomer and the composites. Resin modified glass ionomer showed significantly smaller contact angles in 3 different probe liquids and had higher total surface free energy and stronger polarity, with notably stronger basic property than the composites. CONCLUSION: Resin modified glass ionomer may provide a more favourable environment for bacterial adhesion than composite adhesives.
Adhesives
;
Bacterial Adhesion
;
Dental Cements*
;
Dental Materials
;
Glass
4.Bone regeneration of the fluoridated hydroxyapatite and the bio-glass in the rabbit cranium defect model.
Hyo Joon AHN ; Se Jin HAN ; Kyung Wook KIM
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2011;37(5):380-385
INTRODUCTION: Hydroxyapatite (Ca10(PO4)6(OH)2, HA) is the main inorganic phase of human hard tissue that is used widely as the repair material for bones. When HA is applied to a bony defect, however, it can be encapsulated with fibrous tissue and float in the implanted area due to a lack of consolidation. Bioceramics as allogenic graft materials are added to HA to improve the rate and bone healing capacity. Fluoridated hydroxyapatite (Ca10(PO4)6(OH,F)2, FHA), where F- partially replaces the OH- in hydroxyapatite, is considered a good alternative material for bone repair owing to its solubility and biocompatibility. MATERIALS AND METHODS: This study was designed to determine the bone healing capacity of FHA newly produced as a nanoscale fiber in the laboratory. HA and FHA with bioglass was implanted in a rabbit cranium defect and the specimen was analysed histologically. RESULTS: 1. At 4 weeks, fibrous connective tissue and little bone formation was observed around the materials of the experimental group I implanted HA and bioglass. Newly formed bone was observed around the materials in the experimental group II implanted FHA and bioglass. 2. At 8 weeks, the amount of newly formed and matured bone was higher in experimental group II than in experimental group I and the control group. CONCLUSION: These results suggest that FHA and bioglass is a relatively favorable bone substitute with biocompatibility and better bone healing capacity than pure HA and bioglass.
Acrylic Resins
;
Bone Regeneration
;
Bone Substitutes
;
Ceramics
;
Connective Tissue
;
Durapatite
;
Humans
;
Hydroxides
;
Hydroxyapatites
;
Osteogenesis
;
Skull
;
Solubility
;
Transplants
5.Chronic mercury vapor poisoning of the lung plain radiograph and high resolution CT.
Choong Ki PARK ; Woo Cheol HWANG ; Joon Young NHO ; Bum Gyu AHN ; Hyo Cheol WOO ; Heung Cheol KIM ; Myoung Koo LEE
Journal of the Korean Radiological Society 1993;29(5):961-966
Authors analyzed the findings of findings of chest radiographs and high-resolution CT(HRCT) of chronic mercury vapor poisoning in 12 patients who were diagnosed by previous working history for mercury-thermometer and high level of mercury in blood and urine. The purpose of this paper is to introduce the HRCT findings of chronic mercury vapor poisoning. Duration of mercury exposure was ranged from 10 to 41 months(mean, 21.8 months). Estimated value of serum mercury was ranged from 3.6 to 8.7µg/dl(mean, 5.3 µg/dl: normal value is less than 0.5µg/dl). Estimated value of mercury in urine was ranged from 104 to 482µg/1(mean, 291.4µg/1: normal value is less than 20µg/1). Chest radiographs showed positive findings such as ground-glass opacities and peribronchial cuffings in only 2 out of 12 patients, but HRCT showed positive findings such as ground-glass opacities in 8 patients, peribronchial cuffings in 7 patients, centrilobular abnormalities in 5 patients, interface sign in 4 patients, interlobular septal thickening with intralobular lines in 2 patients and lobular consolidation in one patient. In conclusion, chest HRCT is superior to chest radiograph to show the pulmonary manifestation of chronic mercury vapor poisoning. In patients with chronic mercury vapor poisoning, HRCT findings of centrilobular distributed ground-glass opacities and peribronchial cuffinges are characteristic.
Humans
;
Lung*
;
Poisoning*
;
Radiography, Thoracic
;
Reference Values
;
Thorax
6.Etiological Agents in Bacteremia of Children with Hemato-oncologic Diseases (2006-2010): A Single Center Study.
Ji Eun KANG ; Joon Young SEOK ; Ki Wook YUN ; Hyoung Jin KANG ; Eun Hwa CHOI ; Kyung Duk PARK ; Hee Young SHIN ; Hoan Jong LEE ; Hyo Seop AHN
Korean Journal of Pediatric Infectious Diseases 2012;19(3):131-140
PURPOSE: This study was performed to identify the etiologic agents and antimicrobial susceptibility patterns of organisms responsible for bloodstream infections in pediatric cancer patients for guidance in empiric antimicrobial therapy. METHODS: A 5-year retrospective study of pediatric hemato-oncologic patients with bacteremia in Seoul National University Children's Hospital, from 2006 to 2010 was conducted. RESULTS: A total of 246 pathogens were isolated, of which 63.4% (n=156) were gram-negative, bacteria 34.6% (n=85) were gram-positive bacteria, and 2.0% (n=5) were fungi. The most common pathogens were Klebsiella spp. (n=61, 24.8%) followed by Escherichia coli (n=31, 12.6%), coagulase-negative staphylococci (n=23, 9.3%), and Staphylococcus aureus (n=22, 8.9%). Resistance rates of gram-positive bacteria to penicillin, oxacillin, and vancomycin were 85.7%, 65.9%, and 9.5%, respectively. Resistance rates of gram-negative bacteria to cefotaxime, piperacillin/tazobactam, imipenem, gentamicin, and amikacin were 37.2%, 17.1%, 6.2%, 32.2%, and 13.7%, respectively. Overall fatality rate was 12.7%. Gram-negative bacteremia was more often associated with shock (48.4% vs. 11.9%, P<0.01) and had higher fatality rate than gram-positive bacteremia (12.1% vs. 3.0%, P=0.03). Neutropenic patients were more often associated with shock than non-neutropenic patients (39.6% vs. 22.0%, P=0.04). CONCLUSION: This study revealed that gram-negative bacteria were still dominant organisms of bloodstream infections in children with hemato-oncologic diseases, and patients with gram-negative bacteremia showed fatal course more frequently than those with gram-positive bacteremia.
Amikacin
;
Bacteremia
;
Bacteria
;
Cefotaxime
;
Child
;
Escherichia coli
;
Fever
;
Fungi
;
Gentamicins
;
Gram-Negative Bacteria
;
Gram-Positive Bacteria
;
Humans
;
Imipenem
;
Klebsiella
;
Neutropenia
;
Oxacillin
;
Penicillins
;
Retrospective Studies
;
Shock
;
Staphylococcus aureus
;
Vancomycin
7.Respiratory Variations of Doppler Echocardiographic Parameters in Cardiac Tamponade.
Hyo Gyun JUNG ; Seung Jae JOO ; Dal Su PARK ; Jun Chul PYUN ; Ji Hyun KIM ; Byoung Kun LEE ; Su Yul AHN ; Tae Joon CHA ; Jae Woo LEE
Korean Circulation Journal 1998;28(3):412-424
BACKGROUND: Cardiac tamponade is associated with the expiratory increase and the expira-tory decrease in left ventricular filling flow. With Doppler echocardiography, we analyzed the respiratory variations of mitral and tricuspid inflows, and pulmonary and hepatic venous flows in patients with cardiac tamponade. METHODS: Respiratory hemodynamic changes in mitral and tricuspid inflows and pulmonary and hepatic venous flows were evaluated using Doppler echocardiography in 13 patients (6 men and 7 women; mean age 51+/-13 years) with large pericardial effusion and clinical cardiac tamponade, and compared the results with those of 11 control subjects (3 men and 8 women, mean age 53+/-13 years). Doppler examination was repeated after pericardiocentesis in 6 patients. RESULTS: Peak velocity of early diastolic mitral inflow (E velocity) decreased during inspiration compared with expiratory increase; the mean percentage change was 40%. Peak velocity of late diastolic mitral inflow (A velocity) decreased 13% during inspiration. E/A ratio decreased 31% during inspiration. Deceleration time (DT) and isovolumic relaxation time (IVRT) increased by 26% and 44%, respectively, during inspiration. But respiratory variations of tricuspid inflow were opposite to those of mitral inflow. Tricuspid E velocity increased during inspiration and decre-ased during expiration. The mean percentage change was 123%, which was larger than thte 40% of mitral inflow. The most characteristic findings of pulmonary venous flow during respiration were the expiratory increases of peak diastolic velocity (DV) and diastolic time-velocity integral (D-TVI). The mean percentage changes of peak systolic velocity (SV), DV and D-TVI during respiration were 27%, 45% and 53% respectively. In contrast, the SV and DV of hepatic venous flow increased during inspiration and decreased during expiration. The respiratory variations of peak systolic reverse flow velocity (SR) and peak diastolic reverse flow velocity (DR) were opposite to those of SV and DV. DR notably increased during expiration, and the mean percentage change was 61%. The ratio of RFI (Inspiratory reverse flow integral) to FFI (forward flow integral) of the tamponade group was 270%. The mean percentage changes of each parameters decreased after pericardiocentesis. CONCLUSION: Patients with cardiac tamponade showed inspiratory increases of diastolic tri-cuspid filling flow and hepatic forward flow. Expiratory increases included diastolic mitral filling flow, pulmonary venous systolic and diastolic flow, and hepatic venous reverse flow. Such res-piratory variations decreased after pericardiocentesis.
Cardiac Tamponade*
;
Deceleration
;
Echocardiography*
;
Echocardiography, Doppler
;
Female
;
Hemodynamics
;
Humans
;
Male
;
Pericardial Effusion
;
Pericardiocentesis
;
Relaxation
;
Respiration
8.A comparison of intravaginal misoprostol with intravenous oxytocin for labor induction at term.
Hyo Sang HAN ; Jeong Jae LEE ; Ahn Joon MO ; Jib Kwang CHUNG ; Im Soon LEE ; Kwon Hae LEE
Korean Journal of Obstetrics and Gynecology 2003;46(1):138-143
OBJECTIVE: To compare the safety and efficacy of intravaginally administered misoprostol (PGE1 analogue) versus intravenously administered oxytocin for labor induction at term. METHODS: Among 63 patients over 37 weeks, randomly selected 42 patients were vaginally administered 25 micro gram of misoprostol every 3 hours and the other 21 patients were intravenously administered every minute from 1 mIU/min to 10 mIU/min increasingly. RESULT: The average interval from initiation of induction to labor was notably shorter in oxytocin group than in misoprostol group (204.5+/-332.6 min versus 528.1+/-591.8 min, p<0.02). The average interval from initiation of induction to vaginal delivery was shorter in oxytocin group than in misoprostol group (414.4+/-309.4 min versus 528.1+/-519.8 min, P<0.01) and the difference has statistical meaning. Procedure of labor were divided by 3 stages. We checked the duration of each stage between the two comparative groups. 1st stage (242.7+/-150.14 min versus 605.5+/-805.8 min, P<0.05) 2nd stage (12.6+/-11.9 min versus 19.5+/-11.2 min, P<0.05) The stage duration of oxytocin group was shortened. There was no difference between two groups at the third stage. The incidence of tachysystole, hypertonics, hyperstimulation, meconium passage, abnormal fetal heart rate, fetal weight, apgar score, neonatal morbidity were not different between two group. CONCLUSION: Intravenously administered oxytocin was more effective in shortening labor time than intravaginally administered misoprostol in overall induction labor, but there was no notable difference in the effects on mothers and babies. Considering various situational factors, careful selection should be administered.
Apgar Score
;
Female
;
Fetal Weight
;
Heart Rate, Fetal
;
Humans
;
Incidence
;
Meconium
;
Misoprostol*
;
Mothers
;
Oxytocin*
;
Pregnancy
9.Learning Curve of a Young Surgeon's Video-assisted Thoracic Surgery Lobectomy during His First Year Experience in Newly Established Institution.
Yong Joon RA ; Hyo Yeong AHN ; Min Su KIM
The Korean Journal of Thoracic and Cardiovascular Surgery 2012;45(3):166-170
BACKGROUND: The purpose of this paper is to present a guideline for beginning video-assisted thoracic surgery (VATS) lobectomy to junior surgeons, and to review the first year experience of a new surgeon performing VATS lobectomies who had not performed a VATS lobectomy unassisted during his training period. MATERIALS AND METHODS: A young surgeon opened a division of general thoracic surgery at a medical institution. The surgeon had performed about 100 lobectomies via conventional thoracotomy during his training period, but had never performed a VATS lobectomy unassisted while under the supervision of an expert. After opening the division of general thoracic surgery, the surgeon performed a total of 38 pulmonary lobectomies for various pulmonary diseases from March 2009 to February 2010. All data were collected retrospectively. RESULTS: There were 14 lobectomies via thoracotomy, 14 VATS lobectomies, and 10 cases of attempted VATS lobectomies that were converted to open thoracotomies. The number of VATS lobectomies increased from the second quarter (n=0) to the third quarter (n=5). The lobectomies that were converted from VATS into thoracotomies decreased from the second quarter (n=5) to the third quarter (n=1) (p=0.002). CONCLUSION: It can take 6 months for young surgeons without experience in VATS lobectomy in their training period to be able to reliably perform a VATS lobectomy.
Learning
;
Learning Curve
;
Lung Diseases
;
Organization and Administration
;
Thoracic Surgery
;
Thoracic Surgery, Video-Assisted
;
Thoracoscopy
;
Thoracotomy
10.Analysis of Risk Factor for the Development of Chronic Subdural Hematoma in Patients with Traumatic Subdural Hygroma.
Jun Hyong AHN ; Hyo Sub JUN ; Ji Hee KIM ; Jae Keun OH ; Joon Ho SONG ; In Bok CHANG
Journal of Korean Neurosurgical Society 2016;59(6):622-627
OBJECTIVE: Although a high incidence of chronic subdural hematoma (CSDH) following traumatic subdural hygroma (SDG) has been reported, no study has evaluated risk factors for the development of CSDH. Therefore, we analyzed the risk factors contributing to formation of CSDH in patients with traumatic SDG. METHODS: We retrospectively reviewed patients admitted to Hallym University Hospital with traumatic head injury from January 2004 through December 2013. A total of 45 patients with these injuries in which traumatic SDG developed during the follow-up period were analyzed. All patients were divided into two groups based on the development of CSDH, and the associations between the development of CSDH and independent variables were investigated. RESULTS: Thirty-one patients suffered from bilateral SDG, whereas 14 had unilateral SDG. Follow-up computed tomography scans revealed regression of SDG in 25 of 45 patients (55.6%), but the remaining 20 patients (44.4%) suffered from transition to CSDH. Eight patients developed bilateral CSDH, and 12 patients developed unilateral CSDH. Hemorrhage-free survival rates were significantly lower in the male and bilateral SDG group (log-rank test; p=0.043 and p=0.013, respectively). Binary logistic regression analysis revealed male (OR, 7.68; 95% CI 1.18–49.78; p=0.033) and bilateral SDG (OR, 8.04; 95% CI 1.41–45.7; p=0.019) were significant risk factors for development of CSDH. CONCLUSION: The potential to evolve into CSDH should be considered in patients with traumatic SDG, particularly male patients with bilateral SDG.
Craniocerebral Trauma
;
Follow-Up Studies
;
Hematoma, Subdural, Chronic*
;
Humans
;
Incidence
;
Logistic Models
;
Male
;
Retrospective Studies
;
Risk Factors*
;
Subdural Effusion*
;
Survival Rate