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1.  Myocardial Mechanics in a Rat Model with Banding and Debanding of the Ascending Aorta 
Aortic banding and debanding models have provided useful information on the development and regression of left ventricular hypertrophy (LVH). In this animal study, we aimed to evaluate left ventricular (LV) deformation related to the development and regression of LVH.
Minimally invasive ascending aorta banding was performed in rats (10 Sprague Dawley rats, 7 weeks). Ten rats underwent a sham operation. Thirty-five days later, the band was removed. Echocardiographic and histopathologic analysis was assessed at pre-banding, 35 days of banding and 14 days of debanding.
Banding of the ascending aorta created an expected increase in the aortic velocity and gradient, which normalized with the debanding procedure. Pressure overload resulted in a robust hypertrophic response as assessed by gross and microscopic histology, transthoracic echocardiography [heart weight/tibia length (g/m); 21.0 ± 0.8 vs. 33.2 ± 2.0 vs. 26.6 ± 2.8, p < 0.001]. The circumferential (CS) and radial strains were not different between the groups. However, there were significant differences in the degree of fibrosis according to the banding status (fibrosis; 0.10 ± 0.20% vs. 5.26 ± 3.12% vs. 4.03 ± 3.93%, p = 0.003), and global CS showed a significant correlation with the degree of myocardial fibrosis in this animal model (r = 0.688, p = 0.028).
In this animal study, simulating a severe LV pressure overload state, a significant increase in the LV mass index did not result in a significant reduction in the LV mechanical parameters. The degree of LV fibrosis, which developed with pressure overload, was significantly related to the magnitude of left ventricular mechanics.
PMCID: PMC4286640  PMID: 25580193
Left ventricular hypertrophy; Aortic banding; Debanding
2.  What can be the criteria of outpatient-based endoscopic resection for colon polyp? 
AIM: To investigate whether out-patient based endoscopic mucosal resection (EMR) for colon polyps ≤ 10 mm is safe.
METHODS: Between January 2004 and December 2012, a total of 3015 EMR cases conducted in 1320 patients were retrospectively reviewed. The factors contributing delayed hemorrhage were analyzed. We calculated the probability of delayed bleeding after stratifying conditions of specific risk factors.
RESULTS: The size of the polyp (95%CI: 1.096-1.164, P < 0.001) and patients with chronic renal failure (95%CI: 1.856-45.106, P = 0.007) were identified as independent risk factors for delayed bleeding in multivariate analysis. 95%CI for percent of delayed bleeding according to polyp size was determined for the following conditions: size ≤ 10 mm, 0.05%-0.43%; 20 mm ≥ size > 10 mm, 0.54%-2.08%; size > 20 mm, 4.22%-11.41%. 95%CI was determined for the risk of serious immediate bleeding for a polyp ≤ 10 mm was 0.10%-0.56%. Finally, 95%CI for percent of incomplete resection was 0.07%-0.49% in polyps ≤ 10 mm.
CONCLUSION: It seems acceptable to perform outpatient-based EMR for colon polyps ≤ 10 mm.
PMCID: PMC4198395  PMID: 25324921
Colon; Polyp; Endoscopic mucosal resection; Bleeding
3.  Is Increased Aortic Stiffness Associated with Advanced Ischemic Stroke? 
PMCID: PMC3611112  PMID: 23560136
4.  Rapidly Progressive Cardiac Manifestation of Behçet's Disease Involving Conduction System and Aortic Valve 
Cardiac conduction system impairment is a rare clinical manifestation of Behçet's disease. We report a patient who showed 1st degree atrioventricular block at first presentation, and showed aggravated finding of 3rd degree atrioventricular block on five months later. His cardiac manifestation finally developed to acute severe aortic regurgitation on six months later from his first cardiac manifestation. We observed this rapid progression during 6 months and successfully improved symptom and disease severity of the patient with treatment targeting Behçet's disease.
PMCID: PMC3259545  PMID: 22259664
Behçet's disease; Atrioventricular conduction system; Aortic regurgitation
5.  Estimation of 24-Hour Urinary Sodium Excretion Using Spot Urine Samples 
Nutrients  2014;6(6):2360-2375.
The present study evaluated the reliability of equations using spot urine (SU) samples in the estimation of 24-hour urine sodium excretion (24-HUNa). Equations estimating 24-HUNa from SU samples were derived from first-morning SU of 101 participants (52.4 ± 11.1 years, range 24–70 years). Equations developed by us and other investigators were validated with SU samples from a separate group of participants (n = 224, 51.0 ± 10.9 years, range 24–70 years). Linear, quadratic, and cubic equations were derived from first-morning SU samples because these samples had a sodium/creatinine ratio having the highest correlation coefficient for 24-HUNa/creatinine ratio (r = 0.728, p < 0.001). In the validation group, the estimated 24-HUNa showed significant correlations with measured 24-HUNa values. The estimated 24-HUNa by the linear, quadratic, and cubic equations developed from our study were not significantly different from measured 24-HUNa, while estimated 24-HUNa by previously developed equations were significantly different from measured 24-HUNa values. The limits of agreement between measured and estimated 24-HUNa by six equations exceeded 100 mmol/24-hour in the Bland-Altman analysis. All equations showed a tendency of under- or over-estimation of 24-HUNa, depending on the level of measured 24-HUNa. Estimation of 24-HUNa from single SU by equations as tested in the present study was found to be inadequate for the estimation of an individual’s 24-HUNa.
PMCID: PMC4073156  PMID: 24955740
sodium intake; spot urine; 24-hour collection
6.  Reduction in cardiovascular risk using a proactive multifactorial intervention is consistent among patients residing in Pacific Asian and non-Pacific Asian regions: a CRUCIAL trial subanalysis 
Few trials have compared different approaches to cardiovascular disease prevention among Pacific Asian (PA) populations. The Cluster Randomized Usual Care versus Caduet Investigation Assessing Long-term-risk (CRUCIAL) trial demonstrated that a proactive multifactorial intervention (PMI) approach (based on single-pill amlodipine/atorvastatin) resulted in a greater reduction in calculated Framingham 10-year coronary heart disease (CHD) risk compared with usual care (UC) among hypertensive patients with additional risk factors. One-third of CRUCIAL patients resided in the PA region. The aim of this subanalysis was to compare two approaches to cardiovascular risk factor management (PMI versus UC) among patients residing in PA and non-PA regions.
This subanalysis of the CRUCIAL trial compared treatment-related changes in calculated CHD risk among patients residing in PA and non-PA regions. Sensitivity analyses were conducted among men and women and those with and without diabetes.
Overall, 448 patients (31.6%) resided in the PA region and 969 patients (68.4%) resided in non-PA regions. The PMI approach was more effective in reducing calculated CHD risk versus UC in both PA (−37.1% versus −3.5%; P<0.001) and non-PA regions (−31.1% versus −4.2%; P<0.001); region interaction P=0.131. PA patients had slightly greater reductions in total cholesterol compared with non-PA patients. PA patients without diabetes had slightly greater reductions in CHD risk compared with non-PA patients. Treatment effects were similar in men and women and those with diabetes.
The PMI approach was more effective in reducing calculated Framingham 10-year CHD risk compared with UC among men and women with and without diabetes residing in the PA and non-PA region.
PMCID: PMC3971943  PMID: 24707184
cardiovascular disease; risk factors; hypertension; clinical trial; antihypertensive agents; anticholesteremic agents
7.  Proactive Multifactorial Intervention Strategy Reduces the Risk of Cardiovascular Disease Estimated with Region-Specific Risk Assessment Models in Pacific Asian Patients Participating in the CRUCIAL Trial 
Journal of Korean Medical Science  2013;28(12):1741-1748.
Despite race, ethnic, and regional differences in cardiovascular disease risk, many worldwide hypertension management guidelines recommend the use of the Framingham coronary heart disease (CHD) risk equation to guide treatment decisions. This subanalysis of the recently published CRUCIAL trial compared the treatment-related reductions in calculated CHD and stroke risk among Pacific Asian (PA) patients using a variety of region-specific risk assessment models. As a result, greater reductions in systolic and diastolic blood pressure, low-density lipoprotein cholesterol, and triglycerides were observed in the proactive multifactorial intervention (PMI) arm compared with the usual care arm at Week 52 for PA patients. The relative percentage change in 10-yr CHD risk between baseline and Week 52 in the PMI versus usual care arms was greatest using the NIPPON DATA80 fatal CHD model (LS [least square] mean difference -42.6%), and similar in the SCORE fatal CHD and Framingham total CHD models (LS mean difference -29.4% and -30.8%, respectively). The single-pill based PMI approach is consistently effective in reducing cardiovascular disease risk, evaluated using a variety of risk assessment models. ( registration number: NCT00407537)
PMCID: PMC3857369  PMID: 24339703
Cardiovascular Diseases; Risk Factors; Hypertension; Clinical Trial; Antihypertensive Agents; Anticholesteremic Agents
8.  A Waterborne Outbreak and Detection of Cryptosporidium Oocysts in Drinking Water of an Older High-Rise Apartment Complex in Seoul 
From May to June 2012, a waterborne outbreak of 124 cases of cryptosporidiosis occurred in the plumbing systems of an older high-rise apartment complex in Seoul, Republic of Korea. The residents of this apartment complex had symptoms of watery diarrhea and vomiting. Tap water samples in the apartment complex and its adjacent buildings were collected and tested for 57 parameters under the Korean Drinking Water Standards and for additional 11 microbiological parameters. The microbiological parameters included total colony counts, Clostridium perfringens, Enterococcus, fecal streptococcus, Salmonella, Shigella, Pseudomonas aeruginosa, Cryptosporidium oocysts, Giardia cysts, total culturable viruses, and Norovirus. While the tap water samples of the adjacent buildings complied with the Korean Drinking Water Standards for all parameters, fecal bacteria and Cryptosporidium oocysts were detected in the tap water samples of the outbreak apartment complex. It turned out that the agent of the disease was Cryptosporidium parvum. The drinking water was polluted with sewage from a septic tank in the apartment complex. To remove C. parvum oocysts, we conducted physical processes of cleaning the water storage tanks, flushing the indoor pipes, and replacing old pipes with new ones. Finally we restored the clean drinking water to the apartment complex after identification of no oocysts.
PMCID: PMC3770878  PMID: 24039290
Cryptosporidium parvum; oocyst; cryptosporidiosis; drinking water supply; plumbing system
9.  Feasibility of Real-Time Three-Dimensional Echocardiography for the Assessment of Distorted Biventricular Systolic Function in Patients with Cor Pulmonale 
This study was to investigate the feasibility of real-time 3-dimensional echocardiography (RT3DE) for the analysis of biventricular ejection fractions and volume measurements in patients with cor pulmonale and the correlations of RT3DE results with 64-slice multi-detector cardiac computed tomography (64-MDCT) results.
This study included a total of 22 patients (59.3 ± 16.6 years of age; 10 males and 12 females) who showed flattening or reverse curvature of the interventricular septum and severe pulmonary hypertension [mean right ventricular (RV) systolic pressure = 66.8 ± 19.7 mmHg] on 2-dimensional transthoracic echocardiography due to cor pulmonale. Biventricular end-diastolic and end-systolic volumes were measured by RT3DE and 64-MDCT. The severity of D-shaped deformation was evaluated by using left ventricular (LV) eccentricity index (ratio of diameters parallel/perpendicular to the interventricular septum on parasternal short axis images of the papillary muscle level).
There were moderate correlations between biventricular volumes measured by RT3DE and 64-MDCT except for LV end-systolic volume (59.8 ± 17.1 vs. 73.2 ± 20.2 mL, r = 0.652, p = 0.001 for LV end-diastolic volume; 30.6 ± 9.1 vs. 30.8 ± 12.5 mL, r = 0.361, p = 0.099 for LV end-systolic volume; 110.1 ± 42.9 vs. 171.1 ± 55.3 mL, r = 0.545, p = 0.009 for RV end-diastolic volume; and 80.9 ± 35.0 vs. 128.7 ± 45.1 mL, r = 0.549, p = 0.005 for RV end-systolic volume respectively).
This study suggests that RT3DE may be a modest method for measuring distorted biventricular end-systolic and end-diastolic volumes in patients with cor pulmonale.
PMCID: PMC3701781  PMID: 23837116
Real-time three-dimensional echocardiography; 64-slice multi-detector cardiac computed tomography; Severe pulmonary hypertension; D-shaped deformation; Cor pulmonale
10.  Differences in Adipokine and Hepatokine Levels among Non-diabetic Population Classified by Age and Sex 
Journal of Lifestyle Medicine  2013;3(1):62-67.
Leptin, angiopoietin-related growth factor (AGF), adiponectin (ADP), and retinol-binding protein 4 (RBP4) are cytokines associated with the development of metabolic disorders, such as type 2 diabetes and cardio vascular disease. However, the levels of these cytokines have not extensively studied in non-diabetic subjects. Therefore, we analyzed the differences in these cytokine levels according to sex and age in non-diabetic Korean population.
Blood samples were collected from 59 non-diabetic Korean adults (male, 32; female, 27). The anthropometric and biochemical data were measured at the health examination center. Serum adipokines and hepatokines were measured by enzyme linked immunosorbent assay (ELISA). The data were analyzed according to sex and age-based quartiles.
Serum leptin values were higher in females (8.60 ± 3 μg/ml) compared with males (2.99 ± 2.9 μg/ml). However, RBP4 was higher in males (84.05 ± 47.04 μg/ml) than in females (61.25 ± 45.42 μg/ml). The AGF and ADP values were not significantly different between males and females. RBP4 level was inversely correlated with age quartile in males, while leptin was significantly associated with body mass index and insulin resistance.
RBP4 and AGF levels showed age-associated change, and leptin was consistently higher in females. Therefore, a large-scale analysis to determine the normal range of adipokines and hepatokines concentration in healthy Korean population is necessary. When interpreting adipokine and hepatokine levels, the difference in age and sex needs to be taken into account.
PMCID: PMC4390747  PMID: 26064839
Adiponectin (ADP); Angiopoietin-related growth factor (AGF); Retinol-binding protein 4 (RBP4); Leptin; Non-diabetic subjects
11.  Hematologic Recovery after Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation in Children with High-Risk Solid Tumors 
Journal of Korean Medical Science  2013;28(2):220-226.
Although the number of studies using tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/autoSCT) for the treatment of high-risk pediatric solid tumors has been increasing, documentation of hematologic recovery after tandem HDCT/autoSCT is very limited. For this reason, we retrospectively analyzed the hematologic recovery of 236 children with high-risk solid tumors who underwent tandem HDCT/autoSCT. The median numbers of CD34+ cells transplanted during the first and second HDCT/autoSCT were 4.3 × 106/kg (range 0.6-220.2) and 4.1 × 106/kg (range 0.9-157.6), respectively (P = 0.664). While there was no difference in neutrophil recovery between the first and second HDCT/autoSCT, platelet and RBC recoveries were significantly delayed in the second HDCT/autoSCT (P < 0.001 and P < 0.001, respectively). Delayed recovery in the second HDCT/autoSCT was more prominent when the number of transplanted CD34+ cells was lower, especially if it was < 2 × 106/kg. A lower CD34+ cell count was also associated with increased RBC transfusion requirements and a higher serum ferritin level after tandem HDCT/autoSCT. More CD34+ cells need to be transplanted during the second HDCT/autoSCT in order to achieve the same hematologic recovery as the first HDCT/autoSCT.
PMCID: PMC3565133  PMID: 23400387
High-Dose Chemotherapy; Autologous Stem Cell Transplantation; CD34+ Cells; Hematologic Recovery; Iron Overload
12.  Safety and Efficacy of Fimasartan in Patients with Arterial Hypertension (Safe-KanArb Study) 
Angiotensin II receptor blockers (ARBs) play a key role in hypertension therapy. Recently, fimasartan, the ninth ARB, was developed, but its safety and efficacy have not been well established.
The objective of this study was to determine whether age, sex, concomitant disease, and current antihypertensive medications affect the safety and efficacy of fimasartan in patients with arterial hypertension.
This was a large-scale, open-label observational study to determine the safety and efficacy of fimasartan in patients with hypertension. Patients who were treated for more than 2 months with fimasartan (60 or 120 mg, once daily) were recruited, and the data were systematically collected using electronic case report forms. Written informed consent forms were obtained from all patients.
A total of 14,151 patients (50.7 % males; mean age 59 ± 12 years) were evaluated, of whom 37.9 % were never treated with fimasartan, 53.5 % were switched to fimasartan, and 8.5 % had fimasartan added to their treatment. Overall, fimasartan reduced systolic blood pressure (SBP) from 145.4 ± 18.1 to 126.8 ± 12.6 mmHg and diastolic blood pressure (DBP) from 88.7 ± 11.8 to 79.0 ± 8.7 mmHg (all p < 0.001). The pulse rate decreased from 74.4 ± 10.3 to 71.9 ± 9.2 beats/min in comparison with before treatment (p < 0.001). The reductions were similar between sexes, age groups, and patients with and without co-morbidities, and were not dependent on prior or concomitant treatment with other antihypertensive drugs. Adverse events were reported in 3.31 % (treatment-emergent) and 2.35 % (drug-related) of patients; there were no dose differences for adverse events. The most frequent adverse events were dizziness (1.55 %) and headache (0.52 %); other adverse events were rare. The responder rate (DBP to <90 mmHg or a reduction of ≥10 mmHg) and the goal rate (combined SBP/DBP <140/90 mmHg) were 85.0 and 75.6 %, respectively. Global drug compliance was rated as excellent, very good, good, and poor in 68.1, 26.9, 3.4, and 1.7 % of patients, respectively.
The safety, efficacy, and compliance of fimasartan were found to be excellent in a large patient population that included patients potentially at higher risk for adverse events.
Electronic supplementary material
The online version of this article (doi:10.1007/s40256-013-0004-9) contains supplementary material, which is available to authorized users.
PMCID: PMC3572372  PMID: 23344912
13.  A Case of Left Ventricular Noncompaction Accompanying Fasciculo-Ventricular Accessory Pathway and Atrial Flutter 
Korean Circulation Journal  2012;42(10):705-708.
Left ventricular hypertrabeculation/noncompaction (LVHT) is an uncommon type of genetic cardiomyopathy characterized by trabeculations and recesses within the ventricular myocardium. LVHT is associated with diastolic or systolic dysfunction, thromboembolic complications, and arrhythmias, including atrial fibrillation, ventricular arrhythmias, atrioventricular block and Wolff-Parkinson-White syndrome. Herein, we describe a patient who presented with heart failure and wide-complex tachycardia. Echocardiography showed LVHT accompanied with severe mitral regurgitation. The electrophysiologic study revealed a fasciculo-ventricular accessory pathway and atrial flutter (AFL). The AFL was successfully treated with catheter ablation.
PMCID: PMC3493809  PMID: 23170100
Isolated noncompaction of the ventricular myocardium; Mitral valve insufficiency; Pre-excitation, Mahaim-type; Atrial flutter
14.  Increase in the Late Diastolic Filling Force is Associated With Impaired Transmitral Flow Efficiency in Acute Moderate Elevation of Left Ventricular Afterload 
Journal of Ultrasound in Medicine  2009;28(2):175-182.
Analysis of intraventricular flow force and efficiency is a novel concept of quantitatively assessing left ventricular (LV) hemodynamic performance. We have parametrically characterized diastolic filling flow by early inflow force (EIF), late inflow force (LIF), and total inflow force (TIF) and by vortex formation time (VFT), a fundamental parameter of fluid transport efficiency. The purpose was to determine what changes in inflow forces characterize a decrease in diastolic blood transport efficiency in acute moderate elevation of LV afterload.
Methods and Results
In 8 open-chest pigs, the flow force and VFT parameters were calculated from conventional and flow Doppler echocardiography measurements at baseline and during brief (3-minute) moderate elevation in afterload induced by increasing systolic blood pressure to 130% of baseline value. Systolic LV function decreased significantly during elevated afterload. EIF did not significantly change, whereas LIF increased from 5,822.09 ± 1,656.50 to 13,948.25 ± 9,773.96 dyn (P = 0.0490) and TIF increased from 13,783.35 ± 4,816.58 to 21,836.67 ± 8,635.33 dyn (P = 0.0310). VFT decreased from 4.09 ± 0.29 to 2.79 ± 1.10 (P = 0.0068), confirming suboptimal flow transport efficiency.
Even a brief moderate increase of LV afterload causes a significant increase in the late diastolic filling force and impairs transmitral flow efficiency.
PMCID: PMC3401042  PMID: 19168767
Blood flow velocity; diastolic filling; particle image velocimetry
15.  Hematopoietic stem cell transplantation in children with acute leukemia: similar outcomes in recipients of umbilical cord blood versus marrow or peripheral blood stem cells from related or unrelated donors 
Korean Journal of Pediatrics  2012;55(3):93-99.
This study compared outcomes in children with acute leukemia who underwent transplantations with umbilical cord blood (UCB), bone marrow, or peripheral blood stem cells from a human leukocyte antigen (HLA)-matched related donor (MRD) or an unrelated donor (URD).
This retrospective study included consecutive acute leukemia patients who underwent their first allogeneic hematopoietic stem cell transplantation (HSCT) at Samsung Medical Center between 2005 and 2010. Patients received stem cells from MRD (n=33), URD (n=46), or UCB (n=41).
Neutrophil and platelet recovery were significantly longer after HSCT with UCB than with MRD or URD (P<0.01 for both). In multivariate analysis using the MRD group as a reference, the URD group had a significantly higher risk of grade III to IV acute graft-versus-host disease (GVHD; relative risk [RR], 15.2; 95% confidence interval [CI], 1.2 to 186.2; P=0.03) and extensive chronic GVHD (RR, 6.9; 95% CI, 1.9 to 25.2; P<0.01). For all 3 donor types, 5-year event-free survival (EFS) and overall survival were similar. Extensive chronic GVHD was associated with fewer relapses (RR, 0.1; 95% CI, 0.04 to 0.6; P<0.01). Multivariate analysis showed that lower EFS was associated with advanced disease at transplantation (RR, 3.2; 95% CI, 1.3 to 7.8; P<0.01) and total body irradiation (RR, 2.1; 95% CI, 1.0 to 4.3; P=0.04).
Survival after UCB transplantation was similar to survival after MRD and URD transplantation. For patients lacking an HLA matched donor, the use of UCB is a suitable alternative.
PMCID: PMC3315625  PMID: 22474464
Umbilical cord blood; Hematopoietic stem cell transplantation; Stem cell donor
16.  Higher Plasma Thrombospondin-1 Levels in Patients With Coronary Artery Disease and Diabetes Mellitus 
Korean Circulation Journal  2012;42(2):100-106.
Background and Objectives
Thrombospondin-1 (TSP-1) is associated with atherosclerosis in animals with diabetes mellitus (DM). But, no study has investigated the role of TSP-1 in human atherosclerosis. This study investigated the relationship among plasma TSP-1 concentration, DM, and coronary artery disease (CAD).
Subjects and Methods
The study involved 374 consecutive subjects with suspected CAD, who had undergone coronary angiography to evaluate effort angina. Patients were divided into four groups as follows: DM(-) and CAD(-), DM(-) and CAD(+), DM(+) and CAD(-), and DM (+) and CAD(+).
We found that plasma TSP-1 levels were higher in patients with DM(+) and CAD(+) (n=103) than those in other patients (n=271) (p<0.01). A multivariate analysis showed that male gender {odds ratio (OR), 2.728; 95% confidence interval (CI), 1.035-7.187}, high density lipoprotein-cholesterol (OR, 0.925; 95% CI, 0.874-0.980), glycated hemoglobin (OR, 1.373; 95% CI, 1.037-1.817), and plasma TSP-1 (OR, 1.004; 95% CI, 1.000-1.008) levels were independently associated with the presence of CAD in patients with DM.
Plasma TSP-1 levels were higher in patients with DM(+) and CAD(+) than those in other patients, and plasma TSP-1 levels were independently associated with the presence of CAD in patients with DM. These findings show a possible link between human plasma TSP-1 concentration and CAD in patients with DM.
PMCID: PMC3291719  PMID: 22396697
Thrombospondin-1; Coronary artery disease; Diabetes mellitus
17.  Evaluation of the Relationship between Circadian Blood Pressure Variation and Left Atrial Function Using Strain Imaging 
Non-dippers were reported as showing different left atrial function, compared to dippers, but no study to date investigated the changes in the left atrial function according to the diurnal blood pressure pattern, using tissue Doppler and strain imaging.
Forty never treated hypertensive patients between 30 and 80 years of age were enrolled in this study. Patients were classified as non-dippers when, during night time, they had a blood pressure decrease of less than 10%. Strain of the left atrium was measured during late systole, and peak strain rates of the left atrium were measured during systole, early and late diastolic periods.
The left atrial expansion index, left atrial active emptying volume and left atrial active emptying fraction were all significantly increased in non-dippers. They also had increased values of mean peak left atrial strain (dippers = 21.26 ± 4.23% vs. non-dippers = 24.91 ± 5.20%, p = 0.02), strain rate during reservoir (dippers = 1.29 ± 0.23 s-1 vs. non-dippers =1.52 ± 0.27 s-1, p = 0.01) and contractile period (dippers = -1.38 ± 0.24 s-1 vs. non-dippers = -1.68 ± 0.32 s-1, p < 0.01).
Strain and strain rate acquired from color Doppler tissue imaging demonstrate exaggerated reservoir and booster pump function in never-treated, non-dipper hypertensive patients. These methods are simple and sensitive for the early detection of subtle changes in the left atrial function.
PMCID: PMC3259542  PMID: 22259661
Left atrium; Echocardiography; Strains; Hypertension; Circadian rhythm
18.  Optimal Antithrombotic Strategy in Patients With Atrial Fibrillation After Coronary Stent Implantation 
Korean Circulation Journal  2011;41(10):578-582.
Background and Objectives
Little evidence is available on the optimal antithrombotic therapy following percutaneous coronary intervention (PCI) in patients with atrial fibrillation (AF). We investigated the outcomes of antithrombotic treatment strategies in AF patients who underwent PCI.
Subjects and Methods
Three hundred sixty-two patients (68.0% men, mean age: 68.3±7.8 years) with AF and who had undergone PCI with stent implantation between 2005 and 2007 were enrolled. The clinical, demographic and procedural characteristics were reviewed and the stroke risk factors as well as antithrombotic regimens were analyzed.
The accompanying comorbidities were as follows: hypertension (59.4%), diabetes (37.3%) and congestive heart failure (16.6%). The average number of stroke risk factors was 1.6. At the time of discharge after PCI, warfarin was prescribed for 84 patients (23.2%). Cilostazol was used in addition to dual antiplatelet therapy in 35% of the patients who did not receive warfarin. The mean follow-up period was 615±385 days. The incidences of major adverse cardiac events (MACE), stroke and major bleeding were 11.3%, 3.6% and 4.1%, respectively. By Kaplan-Meier survival analysis, warfarin treatment was not associated with a lower risk of MACE (p=0.886), but it was associated with an increased risk of major bleeding (p=0.002).
Oral anticoagulation therapy after PCI may increase hemorrhagic events in Korean AF patients.
PMCID: PMC3221899  PMID: 22125556
Atrial fibrillation; Angioplasty; Stents; Anticoagulants; Platelet aggregation inhibitors
19.  The report of coping strategies and psychosocial adjustment in Korean mothers of children with cancer 
Psycho-oncology  2009;18(9):956-964.
Parents of children with cancer must cope with multiple challenges over time. As most research on parental coping has been conducted in Western countries, little information is available on the parental experience of coping in non-Western countries. Using a new cultural sample of Korean mothers, this study describes their coping strategies. In addition, the association of particular coping patterns with mothers’ report of psychosocial adjustment is investigated.
A total of 200 Korean mothers of children with cancer participated in the study. Coping strategies were measured by the Coping Health Inventory for Parents in the following three categories: Maintaining Family Integration and an Optimistic Outlook for the Situation, Seeking Social Support, and Seeking Information. Maternal psychosocial adjustment was measured by psychological distress, family relationship, and social relationship subscales from the Psychosocial Adjustment to Illness Scale.
Korean mothers reported coping strategies related to Maintaining Family Integration and an Optimistic Outlook for the Situation as being most helpful. More frequent use of coping pattern, Maintaining Family Integration and an Optimistic Outlook for the Situation, and less frequent use of coping pattern, Information-Seeking were significantly associated with lower psychological distress and better family relationship after children’s medical and maternal characteristics were controlled for. Coping pattern, Seeking Social Support was only predictive of social relationships.
This study suggests that culture may play a significant role in the report of coping among Korean mothers. Future studies should consider culturally preferred coping methods and available resources as they relate to different adjustment outcomes.
PMCID: PMC3056775  PMID: 19117279
coping; Korean; oncology; chronic illness; maternal; psychosocial adjustment
20.  Efficacy of Itraconazole Prophylaxis for Autologous Stem Cell Transplantation in Children with High-Risk Solid Tumors: A Prospective Double-Blind Randomized Study 
Yonsei Medical Journal  2011;52(2):293-300.
The risk of invasive fungal infection is greater for allogeneic hematopoietic stem cell transplantation (HSCT) than for autologous transplantation. Therefore, many transplantation centers use antifungal prophylaxis for allogeneic HSCT, however, there exists no standard guidelines or consensus regarding autologous HSCT.
Materials and Methods
A prospective double-blind randomized study was conducted in autologous HSCT recipients who were divided into prophylaxis and empirical treatment groups, and we investigated the efficacy of itraconazole prophylaxis in pediatric autologous HSCT.
Total 87 autologous HSCT episodes in 55 children with high-risk solid tumors were studied. No invasive fungal infections occurred in either group. However, patients in the prophylaxis group had a significantly shorter duration of fever (p < 0.05) and received antibacterial treatment of shorter duration (p < 0.05) with fewer numbers of antibiotics (p < 0.05 for the use of second line antibiotics) than those in the empirical group. No significant additional adverse events were found with itraconazole prophylaxis.
Although beneficial effects such as a shorter duration of fever and reduced need for antibiotic use were observed in the prophylaxis group, the results were not sufficient to draw a definite recommendation about the routine use of antifungal prophylaxis in pediatric autologous HSCT recipients with high-risk solid tumors (Trial registration: NCT00336531).
PMCID: PMC3051209  PMID: 21319349
Itraconazole; autologous transplantation; antifungal prophylaxis; solid tumor
21.  A Ten-year Survey of Giardia Cysts in Drinking Water Supplies of Seoul, the Republic of Korea 
To understand the distribution of Giardia cysts in drinking water supplies in Seoul, Korea, we collected water samples quarterly at 6 intakes in the Han River, its largest stream and 6 conventional water treatment plants (WTPs) serving drinking water, from 2000 to 2009. Giardia cysts in each of 10 L water were confirmed in 35.0% of intake water samples and the arithmetic mean was 1.65 cysts/10 L (range 0-35 cysts/10 L). The lowest cyst density was observed at Paldang and Kangbuk intakes, and the pollution level was higher at 4 intakes downstream. It seemed that these 4 intakes were under influence of Wangsuk stream at the end of which cysts were found in all samples with the mean of 140 cysts/10 L. The annual mean number of cysts was 0.21-4.21 cysts/10 L, and the cyst level at the second half of the 10 years was about 1/5 of that at first half on average. The cysts were more frequently found in winter, and their mean density was 3.74 cysts/10 L in winter and 0.80-1.08 cysts/10 L in other seasons. All finished water samples collected at 6 WTPs were negative for Giardia in each of 100 L sample for 10 years and cyst removal by physical process was average 2.9-log. It was concluded that conventional water treatment at 6 WTPs of Seoul appears to remove the cysts effectively under the present level of their source water. Domestic wastewater from the urban region could be an important source of Giardia pollution in the river.
PMCID: PMC3063933  PMID: 21461263
Giardia lamblia; cyst; drinking water supply; source water; conventional water treatment; Seoul
22.  Responses and adverse effects of carboplatin-based chemotherapy for pediatric intracranial germ cell tumors 
Korean Journal of Pediatrics  2011;54(3):128-132.
Cisplatin-based chemotherapy has been commonly used for the treatment of intracranial germ cell tumors (IC-GCTs). However, this treatment exhibits some adverse effects such as renal problems and hearing difficulty. Carboplatin-based chemotherapy was administered to pediatric patients with IC-GCTs from August 2004 at the Samsung Medical Center. In this study, we assessed the responses and adverse effects of carboplatin-based chemotherapy in pediatric IC-GCTs patients according to the risk group, and compared the results with those of the previous cisplatin-based chemotherapy.
We examined 35 patients (27 men and 8 women) diagnosed with IC-GCTs between August 2004 and April 2008 and received risk-adapted carboplatin-based chemotherapy at the Samsung Medical Center. Patients were divided into either low-risk (LR) or high-risk (HR) groups and a retrospective analysis was performed using information from the medical records.
Although hematological complications were common, hearing difficulties or grade 3 or 4 creatinine level elevation were not observed in patients who underwent carboplatin-based chemotherapy. The frequency of febrile neutropenia did not differ between the risk groups. The overall survival was 100% and event-free survival (EFS) was 95.7%. The EFS rate was 100% in the LR group and 90% in the HR group, respectively.
Despite their common occurrence in high-risk patients, no lethal hematological complications were associated with carboplatin-based treatment. The current carboplatin-based chemotherapy protocol is safe and effective for the treatment of pediatric patients with IC-GCTs.
PMCID: PMC3120999  PMID: 21738543
Intracranial germ cell tumor; Carboplatin; Adverse effects
23.  A Survey of Cryptosporidium Oocysts in Water Supplies during a 10-Year Period (2000-2009) in Seoul 
This study has been conducted to estimate the occurrence of Cryptosporidium oocysts in water supplies in the Metropolitan area of Seoul, South Korea, for 10 years from 2000 to 2009. Water samples were collected quarterly at 6 intakes in the Han River and its largest stream and 6 conventional Water Treatment Plants (WTPs) serving drinking water for 10 million people of Seoul. Cryptosporidium oocysts were found in 22.5% of intake water samples and arithmetic mean was 0.65 oocysts/10 L (range 0-22 oocysts/10 L). Although the annual mean of oocyst number was as low as 0.04-1.90 oocysts/10 L, 3 peaks in 2004 and 2007 were observed and the pollution level was a little higher in winter. The lowest density was observed at Paldang intake and the pollution level increased at Kuui and Jayang intakes. At the end of the largest stream, oocysts were found in 70% of collected samples (mean 5.71 oocysts/10 L) and it seemed that its joining the Han River resulted in the increase at Kuui intake and downstream. Oocyst removal by physical process exceeded 2.0-2.3 log and then all finished water samples collected at 6 WTPs were negative for Cryptosporidium in each 100 L sample for 10 years. These results suggested that domestic wastewater from the urban region could be a source of Cryptosporidium pollution and separating sewage systems adjacent to the intakes could be meaningful for some intakes having weakness related to parasitological water quality.
PMCID: PMC2945796  PMID: 20877500
Cryptosporidium; oocysts; drinking water supply; river water; conventional water treatment; Seoul
24.  Acute Coronary Syndrome Mimicking Atypical Stress-Induced Cardiomyopathy in a Patient with Panhypopituitarism 
Stress-induced cardiomyopathy is frequently confused with acute coronary syndromes. We encountered a 64-year old female patient with panhypopituitarism initially suspected as atypical stress-induced cardiomyopathy due to her history and initial echocardiographic findings. She was finally diagnosed as non ST-segment elevation myocardial infarction based on the findings of coronary angiogram, intravascular ultrasound and subsequent echocardiogram.
PMCID: PMC2889386  PMID: 20661331
Stress-induced cardiomyopathy; Acute coronary syndrome; Echocardiography
25.  Successful Radiofrequency Catheter Ablation for Wolff-Parkinson-White Syndrome Within the Neck of a Coronary Sinus Diverticulum 
Korean Circulation Journal  2009;39(9):389-391.
Posteroseptal accessory pathways are often associated with coronary sinus diverticula. These diverticula contain myocardial coats which serve as a bypass tract. We report a 54-year-old woman who underwent radiofrequency (RF) catheter ablation for Wolff-Parkinson-White (WPW) syndrome. The surface electrocardiography (ECG) demonstrated pre-excitation, indicating a posteroseptal accessory pathway. A catheter ablation via a transaortic approach failed to ablate the accessory pathway. Coronary sinus venography revealed the presence of a diverticulum near the ostium. An electrogram in the neck of the diverticulum showed the coronary sinus myocardial extension potential, which was successfully ablated by delivery of RF energy.
PMCID: PMC2771829  PMID: 19949625
Wolff-Parkinson-white syndrome; Coronary sinus; Diverticulum; Radiofrequency catheter ablation

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