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1.  An Optimized Adsorbent Sampling Combined to Thermal Desorption GC-MS Method for Trimethylsilanol in Industrial Environments 
Trimethylsilanol (TMSOH) can cause damage to surfaces of scanner lenses in the semiconductor industry, and there is a critical need to measure and control airborne TMSOH concentrations. This study develops a thermal desorption (TD)-gas chromatography (GC)-mass spectrometry (MS) method for measuring trace-level TMSOH in occupational indoor air. Laboratory method optimization obtained best performance when using dual-bed tube configuration (100 mg of Tenax TA followed by 100 mg of Carboxen 569), n-decane as a solvent, and a TD temperature of 300°C. The optimized method demonstrated high recovery (87%), satisfactory precision (<15% for spiked amounts exceeding 1 ng), good linearity (R2 = 0.9999), a wide dynamic mass range (up to 500 ng), low method detection limit (2.8 ng m−3 for a 20-L sample), and negligible losses for 3-4-day storage. The field study showed performance comparable to that in laboratory and yielded first measurements of TMSOH, ranging from 1.02 to 27.30 μg/m3, in the semiconductor industry. We suggested future development of real-time monitoring techniques for TMSOH and other siloxanes for better maintenance and control of scanner lens in semiconductor wafer manufacturing.
PMCID: PMC3433126  PMID: 22966229
2.  Design of an Implantable Device for Ocular Drug Delivery 
Journal of Drug Delivery  2012;2012:527516.
Ocular diseases, such as, glaucoma, age-related macular degeneration (AMD), diabetic retinopathy, and retinitis pigmentosa require drug management in order to prevent blindness and affecting million of adults in USA and worldwide. There is an increasing need to develop devices for drug delivery to address ocular diseases. This study focuses on the design, simulation, and development of an implantable ocular drug delivery device consisting of micro-/nanochannels embedded between top and bottom covers with a drug reservoir made from polydimethylsiloxane (PDMS) which is silicon-based organic and biodegradable polymer. Several simulations were carried out with six different micro-channel configurations in order to see the feasibility for ocular drug delivery applications. Based on the results obtained, channel design of osmotic I and osmotic II satisfied the diffusion rates required for ocular drug delivery. Finally, a prototype illustrating the three components of the drug delivery design is presented. In the future, the device will be tested for its functionality and diffusion characteristics.
PMCID: PMC3418683  PMID: 22919500
3.  Long-Term Safety and Efficacy of Sirolimus- and Paclitaxel-Eluting Stents in Patients With Acute Myocardial Infarction: Four-Year Observational Study 
Korean Circulation Journal  2012;42(4):266-273.
Background and Objectives
The comparison of long-term clinical effects between Sirolimus-eluting stent (SES) and Paclitaxel-eluting stents (PES) for treatment of acute myocardial infarction (AMI) remains unclear. Seeking to clarify this issue, we performed a retrospective analysis to evaluate four-year clinical outcomes of SES compared to PES treated AMI patients.
Subjects and Methods
From January 2004 to August 2006, all patients with acute ST-segment elevation myocardial infarction and acute non-ST segment elevation myocardial infarction who underwent percutaneous coronary intervention (PCI) by implantation of either SES or PES were enrolled. The occurrences of cardiac and non-cardiac deaths, recurrent infarction, target vessel revascularization (TVR) and stent thrombosis were analyzed. The composite end points of these major adverse cardiac events (MACE) were also analyzed.
During the study period, a total of 668 AMI patients had visited, of which 522 patients (299 with SES and 223 with PES) were enrolled. During the four-year clinical follow-up, both groups showed similar occurrences of non-cardiac death (14.6±2.2% vs. 18.3±3.0%, p=0.26); cardiac death (6.8±1.52% vs. 11.2±2.6%, p=0.39); re-infarction (3.3±1.1% vs. 6.4±1.8%, p=0.31); and stent thrombosis (3.2±1.1% vs. 5.4±1.7%, p=0.53). However, occurrences of TVR {4.0±1.2% vs. 10.0±3.0%, hazard ratio (HR)=0.498, 95% confidence interval (CI)=0.257-0.967, p=0.039} and MACE (19.4±2.5% vs. 29.4±3.5%, HR=0.645, 95% CI=0.443-0.940, p=0.021) were significantly lower in the SES population.
In AMI patients treated with either SES or PES implantation, the former had a significantly lower risk of TVR and MACE during four-year clinical follow-up. Rates of death, cardiac death or recurrent infarction, and stent thrombosis were similar.
PMCID: PMC3341424  PMID: 22563340
Acute myocardial infarction; Percutaneous coronary intervention; Stents
4.  A Comparison of Different Techniques of Two-Dimensional Speckle-Tracking Strain Measurements of Right Ventricular Systolic Function in Patients with Acute Pulmonary Embolism 
Speckle-tracking echocardiography has been applied to measure right ventricular (RV) systolic function in various diseases. However, variations in strain measurement by different vendors have limited the application of these techniques for assessment of RV function. We sought to compare two methods for the assessment of RV systolic function in patients with acute pulmonary embolism (PE).
From August 2007 to May 2011, all consecutive PE patients were prospectively included in this cohort study. Global longitudinal strains of RV measured with EchoPAC PC software (GLSRV-EchoPAC; GE Medical Systems) and velocity vector imaging (GLSRV-VVI; Siemens Medical Systems) were recorded on the same set of echocardiographic images.
We analyzed a total of 50 patients (12 males, 68 ± 14 years) with acute PE in this study. GLSRV-EchoPAC and GLSRV-VVI were correlated (r = 0.793, p < 0.001) and they showed significant correlations with conventional echocardiographic parameters of RV systolic function and Log B-type natriuretic peptide (BNP) level. However, GLSRV-VVI only showed significant correlations with cardiac biomarkers as serum creatinine kinase-MB (r = 0.367, p = 0.010) and tropoinin-I concentrations (r = 0.294, p = 0.040).
GLSRV-VVI and GLSRV-EchoPAC showed significant correlations with conventional echocardiographic parameters of RV systolic function and LogBNP value in patients with PE.
PMCID: PMC4096667  PMID: 25031796
Right ventricle; Pulmonary embolism; Strain echocardiography
6.  A Prospective, Randomized Comparison of Promus Everolimus-Eluting and TAXUS Liberte Paclitaxel-Eluting Stent Systems in Patients with Coronary Artery Disease Eligible for Percutaneous Coronary Intervention: The PROMISE Study 
Journal of Korean Medical Science  2013;28(11):1609-1614.
We aimed comparing two-year clinical outcomes of the Everolimus-Eluting Promus and Paclitaxel-Eluting TAXUS Liberte stents used in routine clinical practice. Patients with objective evidence of ischemia and coronary artery disease eligible for PCI were prospectively randomized to everolimus-eluting stent (EES) or paclitaxel-eluting stent (PES) groups. The primary end-point was ischemia-driven target vessel revascularization (TVR) at 2 yr after intervention, and the secondary end-point was a major adverse cardiac event (MACE), such as death, myocardial infarction (MI), target lesion revascularization (TLR), TVR or stent thrombosis. A total of 850 patients with 1,039 lesions was randomized to the EES (n=425) and PES (n=425) groups. Ischemic-driven TVR at 2 yr was 3.8% in the PES and 1.2% in the EES group (P for non-inferiority=0.021). MACE rates were significantly different; 5.6% in PES and 2.5% in EES (P = 0.027). Rates of MI (0.8% in PES vs 0.2% in EES, P = 0.308), all deaths (1.5% in PES vs 1.2% in EES, P = 0.739) and stent thrombosis (0.3% in PES vs 0.7% in EES, P = 0.325) were similar. The clinical outcomes of EES are superior to PES, mainly due to a reduction in the rate of ischemia-driven TVR.
PMCID: PMC3835502  PMID: 24265523
Everolimus-Eluting Stent; Paclitaxel-Eluting Stent
7.  Flail Subaortic Membrane Mimicking Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy 
A subaortic membrane is an uncommon cause for left ventricular outflow tract obstruction. Hypertrophic cardiomyopathy with dynamic left ventricular outflow tract obstruction would mask the presence of the subaortic membrane on transthoracic echocardiography and cause a false diagnosis. We report a patient with subaortic stenosis due to flail subaortic membrane misdiagnosed as obstructive hypertrophic cardiomyopathy on transthoracic echocardiography, identified on transesophageal echocardiography and cardiac catheterization.
PMCID: PMC3701784  PMID: 23837119
Subaortic membrane; Hypertrophic cardiomyopathy; Transesophageal echocardiography
8.  Acute and Long-Term Angiographic Outcomes of Side Branch Stenosis after Randomized Treatment of Zotarolimus-, Sirolimus-, and Paclitaxel-Eluting Stent for Coronary Artery Stenosis 
Journal of Korean Medical Science  2012;27(12):1499-1506.
This was designed to assess the outcomes of side branch (SB) stenosis after implantation of three drug-eluting stents (DES). From 2,645 patients in the ZEST (Comparison of the Efficacy and Safety of Zotarolimus-Eluting Stent with Sirolimus-Eluting and PacliTaxel-Eluting Stent for Coronary Lesions) Trial, 788 patients had 923 bifurcation lesions with SB ≥ 1.5 mm were included. SB was treated in 150 lesions, including 35 (3.8%) receiving SB stenting. Of untreated SB with baseline stenosis < 50%, the incidences of periprocedural SB compromise was similar in the zotarolimus (15.8%), sirolimus (17.2%), and paclitaxel (16.6%) stent groups (P = 0.92). At follow-up angiography, delayed SB compromise occurred in 13.9%, 3.2%, and 9.4% (P = 0.010) of these groups. When classified into four groups (< 50%, 50%-70%, 70%-99%, and 100%), 9.0% of untreated SB were worsened, whereas improvement and stationary were observed in 9.6% and 81.4%. In a multivariable logistic regression model, main branch (MB) stenosis at follow-up (%) was the only independent predictor of SB stenosis worsening (odds ratio, 1.03; 95% confidence interval, 1.01-1.04; P < 0.001). After MB stenting in bifurcation lesions, a minority of SB appears to worsen. DES with strong anti-restenotic efficacy may help maintain SB patency.
PMCID: PMC3524429  PMID: 23255849
Drug-Eluting Stents; Bifurcation; Percutaneous Coronary Intervention; Zotarolimus; Sirolimus; Paclitaxel
9.  Evaluation of Right Ventricular Systolic Function by the Analysis of Tricuspid Annular Motion in Patients with Acute Pulmonary Embolism 
Measurement of right ventricular (RV) systolic function is important for patients with acute pulmonary embolism (PE). However, assessment of RV function is a challenge due to its complex anatomy. We measured RV systolic function with analysis of tricuspid annular motion in acute PE patients.
From August 2007 to May 2011, all consecutive PE patients were prospectively included. Tricuspid annular motion was analyzed with tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular systolic velocity (TASV).
We analyzed total 50 patients (38 females, 68 ± 14 years). Mean RV fractional area change (RVFAC) was 26.2 ± 10.8%; RV Tei index 0.78 ± 0.35; TR Vmax 3.8 ± 0.5 m/sec; pulmonary vascular resistance (PVR) 3.5 ± 1.2 WU. TAPSE was 16 ± 4 mm and TASV was 11.7 ± 4.0 cm/sec. TAPSE showed significant correlations with RVFAC (r = 0.841, p < 0.001), RV Tei index (r = -0.347, p = 0.018), Log B-type natriuretic peptide (BNP) (r = -0.634, p < 0.001) and PVR (r = -0.635, p < 0.001). TASV also revealed significant correlations with RVFAC (r = 0.605, p < 0.001), RV Tei index (r = -0.380, p = 0.009), LogBNP (r = -0.477, p = 0.001) and PVR (r = -0.483, p = 0.001). The best cutoff of TAPSE for detection of RV systolic dysfunction (defined as RVFAC < 35%) was 1.75 cm [Areas under the curve (AUC) = 0.96, p < 0.001] with a sensitivity of 87% and specificity 91%. The best cutoff for TASV was 13.8 cm/sec (AUC = 0.90, p < 0.001), sensitivity 86% and specificity 78%. However, there was no statistical significance in the detection of RV dysfunction (difference = 0.07, 95% CI = -0.21-0.17, p = 0.130) between TAPSE and TASV.
TAPSE and TASV showed significant correlations with conventional echocardiographic parameters of RV function and LogBNP value. These values can be used to detect RV systolic dysfunction more easily in patients with acute PE.
PMCID: PMC3542511  PMID: 23346287
Right ventricle; Pulmonary embolism; Echocardiography; Tricuspid annulus
10.  Missed Diagnosis of Syrinx 
Asian Spine Journal  2012;6(1):1-5.
Study Design
Prospective, randomized, controlled human study.
We checked the proportion of missed syrinx diagnoses among the examinees of the Korean military conscription.
Overview of Literature
A syrinx is a fluid-filled cavity within the spinal cord or brain stem and causes various neurological symptoms. A syrinx could easily be diagnosed by magnetic resonance image (MRI), but missed diagnoses seldom occur.
In this study, we reviewed 103 cases using cervical images, cervical MRI, or whole spine sagittal MRI, and syrinxes was observed in 18 of these cases. A review of medical certificates or interviews was conducted, and the proportion of syrinx diagnoses was calculated.
The proportion of syrinx diagnoses was about 66.7% (12 cases among 18). Missed diagnoses were not the result of the length of the syrinx, but due to the type of image used for the initial diagnosis.
The missed diagnosis proportion of the syrinx is relatively high, therefore, a more careful imaging review is recommended.
PMCID: PMC3302909  PMID: 22439081
Syrinx; Diagnosis proportion; Conscription; Korea
11.  Transient Use of Oral Bosentan Can Be an Additional Option to Reduce Pulmonary Arterial Hypertension in a Patient with Severe Pulmonary Arterial Hypertension Associated with Atrial Septal Defect 
Atrial septal defect (ASD) with severe pulmonary arterial hypertension (PAH) is thought to preclude shunt closure. However, there are several reports that vasodilator treatment is associated with good clinical outcome in these patients, recently. We report a case of good clinical outcome in a patient with ASD and severe PAH successfully treated with operative closure of ASD and subsequent use of oral bosentan medication. This case supports that the corrective repair of ASD and an oral bosentan treatment can be one of the treatment options in the selected patients with severe PAH associated with ASD.
PMCID: PMC3209598  PMID: 22073329
Atrial septal defect; Pulmonary arterial hypertension; Bosentan
12.  Endothelial progenitor cell transplantation decreases lymphangiogenesis and adverse myocardial remodeling in a mouse model of acute myocardial infarction 
Experimental & Molecular Medicine  2011;43(8):479-485.
Cardiac lymphatic system in the remodeling after acute myocardial infarction (AMI) has been overlooked. We wanted to investigate the role of bone marrow-derived endothelial progenitor cells (EPCs) and their contribution to lymphatic distribution in myocardial remodeling after AMI. Mouse (C57bl/6J) MI models were created by ligation of the left anterior descending coronary artery and were treated with phosphate buffered saline (PBS) or EPCs. Real-time RT-PCR with 2- to 4-week myocardial tissue samples revealed that lymphangiogenetic factors such as vascular endothelial growth factor (VEGF)-C (8.5 fold, P < 0.05), VEGF-D (6.1 fold, P < 0.05), Lyve-1 (15 fold, P < 0.05), and Prox-1 (11 fold, P < 0.05) were expressed at significantly higher levels in the PBS group than the EPC group. The PBS group also showed a significantly higher density of lymphatic vessels in the peri-infarction area. Echocardiography showed that from 2 weeks after the treatment, left ventricle (LV) dimensions at both systole and diastole were significantly smaller in the EPC group than in the PBS group (P < 0.01) and LV fractional shortening was higher in the EPC group accordingly (P < 0.01). Lymphangiogenic markers increased in a mouse MI model. EPC transplantation decreased lymphangiogenesis and adverse ventricular remodeling after AMI. These novel findings suggest that new lymphatic vessels may be formed in severely damaged myocardium, and may be involved in adverse myocardial remodeling after AMI.
PMCID: PMC3174382  PMID: 21694495
endothelial cells; lymphangiogenesis; myocardial infarction; stem cells; ventricular remodeling
13.  Prevalence and Patterns of Left Ventricular Dysfunction in Patients with Pheochromocytoma 
Excessive catecholamine release in pheochromocytoma is known to cause transient reversible left ventricular (LV) dysfunction, such as in the case of pheochromocytoma-associated catecholamine cardiomyopathy. We investigated patterns of clinical presentation and incidence of LV dysfunction in patients with pheochromocytoma.
From January 2004 to April 2011, consecutive patients with pheochromocytoma were retrospectively studied with clinical symptoms, serum catecholamine profiles, and radiologic findings. Patterns of electrocardiography and echocardiography were also analyzed.
During the study period, a total of 36 patients (21 males, 49.8 ± 15.8 years, range 14-81 years) with pheochromocytoma were included. In the electrocardiographic examinations, normal findings were the most common findings (19, 52.8%). LV hypertrophy in 12 cases (33.3%), sinus tachycardia in 3 (8.3%), ischemic pattern in 1 (2.8%) and supraventricular tachycardia in 1 (2.8%). Echocardiographic exam was done in 29 patients (80.6%). Eighteen patients (62.1%) showed normal finding, 8 (27.6%) revealed concentric LV hypertrophy with normal LV systolic function, and 3 (10.3%) demonstrate LV systolic dysfunction (LV ejection fraction < 50%). Three showed transient LV dysfunction (2 with inverted Takotsubo-type cardiomyopathy and 1 with a diffuse hypokinesia pattern). Common presenting symptoms in the 3 cases were new onset chest discomfort and dyspnea which were not common in the other patients. Their echocardiographic abnormalities were normalized with conventional treatment within 3 days.
Out of total 36 patients with pheochromocytoma, 3 showed transient LV systolic dysfunction (catecholamine cardiomyopathy). Pheochromocytoma should be included as one of possible causes of transient LV systolic dysfunction.
PMCID: PMC3150700  PMID: 21860721
Pheochromocytoma; Catecholamine cardiomyopathy; Echocardiography
14.  Endothelial Dysfunction in the Smokers Can Be Improved with Oral Cilostazol Treatment 
Smoking is one of well known environmental factors causing endothelial dysfunction and plays important role in the atherosclerosis. We investigated the effect of cilostazol could improve the endothelial dysfunction in smokers with the measurement of flow-mediated dilatation (FMD).
We enrolled 10 normal healthy male persons and 20 male smokers without any known cardiovascular diseases. After measurement of baseline FMD, the participants were medicated with oral cilostazol 100 mg bid for two weeks. We checked the follow up FMD after two weeks and compared these values between two groups.
There was no statistical difference of baseline characteristics including age, body mass index, serum cholesterol profiles, serum glucose and high sensitive C-reactive protein between two groups. However, the control group showed significantly higher baseline endothelium-dependent dilatation (EDD) after reactive hyperemia (12.0 ± 4.5% in the control group vs. 8.0 ± 2.1% in the smoker group, p = 0.001). However, endothelium-independent dilatation (EID) after sublingual administration of nitroglycerin was similar between the two groups (13.6 ± 4.5% in the control group vs. 11.9 ± 4.9% in the smoker group, p = 0.681). Two of the smoker group were dropped out due to severe headache. After two weeks of cilostazol therapy, follow-up EDD were significantly increased in two groups (12.0 ± 4.5% to 16.1 ± 3.7%, p = 0.034 in the control group and 8.0 ± 2.1% to 12.2 ± 5.1%, p = 0.003 in the smoker group, respectively). However, follow up EID value was not significantly increased compared with baseline value in both groups (13.6 ± 4.5% to 16.1 ± 3.7%, p = 0.182 in the control group and 11.9 ± 4.9% to 13.7 ± 4.3%, p = 0.430 in the smoker group, respectively).
Oral cilostazol treatment significantly increased the vasodilatory response to reactive hyperemia in two groups. It can be used to improve endothelial function in the patients with endothelial dysfunction caused by cigarette smoking.
PMCID: PMC3079080  PMID: 21519488
Endothelial dysfunction; Smoking; Cilostazol
15.  Effect of Atorvastatin and Clopidogrel Co-Administration After Coronary Stenting in Korean Patients With Stable Angina 
Korean Circulation Journal  2011;41(1):28-33.
Background and Objectives
It was reported that atorvastatin co-administered with clopidogrel for 8 months did not affect the anti-platelet potency of clopidogrel in Korean patients with acute coronary syndrome, but not in patients with stable angina. We investigated whether co-administration of statins with clopidogrel affected the anti-platelet efficacy of clopidogrel in Korean patients with stable angina.
Subjects and Methods
This was a randomized, open-label and two-period crossover design study conducted at two centers. Two hundreds thirty three patients with stable angina scheduled for coronary stenting were randomized into two groups. In Group A, 119 patients first received atorvastatin (10 mg) followed by fluvastatin (80 mg) for 12 weeks per treatment. In Group B, 114 patients received the same treatments in reverse order.
Baseline adenosine diphosphate (ADP, 10 µmol/L)-induced platelet aggregation was 54.4±9.1% in Group A and 53.8±9.0% in Group B (p=0.44), and significant differences were noted after each treatment period (p<0.001). Inhibition of platelet aggregation was similar between Group A and Group B at 24 hours following clopidogrel loading (29.2±11.0% vs. 30.4±12.7%; p=0.42). The two treatment least square means of 12-week ADP (10 mol/L)-induced platelet aggregation [29.50±0.79 {standard error (SE)}% on the atorvastatin treatment group vs. 28.16±0.70 (SE)% in the fluvastatin treatment group] in a 2×2 cross-over study were not significantly different (p=0.204).
Statin and clopidogrel co-administration for 12 weeks is not associated with attenuated anti-platelet activity of clopidogrel in Korean patients with stable angina after coronary stenting, in support of the findings of similar studies conducted in Caucasian populations.
PMCID: PMC3040400  PMID: 21359066
Clopidogrel; Cardiovascular diseases; Cytochrome P450 3A4 protein, human; Atorvastatin; Stents
16.  Effects of Statins on the Epicardial Fat Thickness in Patients with Coronary Artery Stenosis Underwent Percutaneous Coronary Intervention: Comparison of Atorvastatin with Simvastatin/Ezetimibe 
Epicardial fat is a visceral thoracic fat and known to be related with presence of dyslipidemia and coronary arterial stenosis. We evaluated the effects and differences of statins on epicardial fat thickness (EFT) in patients underwent successful percutaneous coronary intervention (PCI).
In this retrospective cohort study, we enrolled consecutive patients underwent successful PCI and scheduled six to eight-months follow-up coronary angiography from March 2007 to June 2009. EFT was measured by echocardiography twice at the time of PCI and the follow-up coronary angiography. We included 145 patients (58 females; mean, 63.5 ± 9.5 years).
Of the 145 patients, 82 received 20 mg of atorvastatin (atorvastatin group) and 63 medicated with 10 mg of simvastatin with 10 mg of ezetimibe (simvastatin/ezetimibe group). With statin treatments, total cholesterol concentration (189.1 ± 36.1 to 143.3 ± 36.5 mg/dL, p < 0.001), triglycerides (143.5 ± 65.5 to 124.9 ± 63.1 mg/dL, p = 0.005), low density lipoprotein-cholesterol (117.4 ± 32.5 to 76.8 ± 30.9 mg/dL, p < 0.001) and EFT (4.08 ± 1.37 to 3.76 ± 1.29 mm, p < 0.001) were significantly decreased. Atorvastatin and simvastatin/ezetimibe showed similar improvements in the cholesterol profiles. However, atorvastatin decreased EFT more significantly than simvastatin/ezetimibe (EFT change 0.47 ± 0.65 in the atorvastatin vs. 0.12 ± 0.52 mm in the simvastatin/ezetimibe group; p = 0.001).
In this study, the atorvastatin group showed significant reduction in EFT than in the simvastatin/ezetimibe group. This might be originated from the statin difference. More large, randomized study will be needed to evaluate this statin difference.
PMCID: PMC3021889  PMID: 21253360
Percutaneous coronary intervention; Epicardial fat; Statins
17.  Phenotypic Differences of Gastric Cancer according to the Helicobacter pylori Infection in Korean Patients 
Journal of Gastric Cancer  2010;10(4):168-174.
Infection with Helicobacter pylori is an important risk factor for gastric cancer in humans. We compared the clinicopathologic features of gastric cancer patients based on H. pylori infection.
Materials and Methods
We prospectively studied 155 patients who had gastric cancer and underwent gastrectomies in 1 hospital in Korea. We examined H. pylori infections using the rapid urease test (RUT) with gastrectomy specimens and collected clinical and pathologic data.
The number of H. pylori infections based on the RUT was 137 (88%). The H. pylori-negative group was significantly associated with AGC and tumor histology. H. pylori infection was significantly correlated with type I/IIa in EGC and type III/IV/V in AGC. AGC was significantly correlated with larger tumor size, lymphatic invasion, perineural invasion, and H. pylori infection based on univariate and multivariate analyses.
We report the prevalence of H. pylori based on the RUT in gastric cancer patients. H. pylori infection influences the tumor histology, progression, and growth type of gastric cancer.
PMCID: PMC3204496  PMID: 22076182
Helicobacter pylori; Stomach neoplasms; Phenotype
18.  Tumor Suppressor Serine/Threonine Kinase LKB1 Expression, Not Kinase Activity, Increased in the Vascular Smooth Muscle Cells and Neointima in the Rat Carotid Artery Injury Model 
Korean Circulation Journal  2010;40(11):552-557.
Background and Objectives
Vascular smooth muscle cell (VSMC) proliferation is responsible for the restenosis of previously inserted coronary stents. Angiotensin II (Ang II) is known to regulate VSMC proliferation. LKB1, a serine/threonine kinase, interacts with the p53 pathway and acts as a tumor suppressor.
Materials and Methods
We assessed the association of Ang II and the expression of LKB1 in primary cultured murine VSMCs and neointima of the Sprague Dawley rat carotid artery injury model. We created carotid balloon injuries and harvested the injured carotid arteries 14 days after the procedure.
Ang II increased LKB1 expression in a time-dependent manner and peaked at an Ang II concentration of 10-7 mole/L in VSMCs. In the animal experiment, neointima was markedly increased after balloon injury compared to the control group. Immunohistochemical studies showed that LKB1 expression increased according to neointima thickness. Ang II augmented LKB1 expression after the injury. Western blot analysis of LKB1 with carotid artery lysate revealed the same pattern as LKB1 immunohistochemistry. Increased LKB1 expression started at 5 days after the balloon injury, and peaked at 14 days after the injury. Although LKB1 expression was increased after the injury, LKB1 kinase activity was not increased. Ang II or balloon-injury increased the expression of LKB1 although the LKB1 activity was reduced.
Ang II increased LKB1 expression in VSMCs and neointima. These findings were not kinase dependant.
PMCID: PMC3008825  PMID: 21217931
Angiotensin II; LKB1 protein, rat; Coronary restenosis
19.  A Successful Primary Percutaneous Coronary Intervention Twelve Days After a Cabrol Composite Graft Operation in Marfan Syndrome 
Korean Circulation Journal  2010;40(5):247-250.
The Cabrol procedure is one of several techniques used for re-implantation of a coronary artery. After replacement of the ascending aorta and aortic valve using a composite graft, second Dacron tube grafts are used for anastomosis between the ascending aortic graft and the coronary arteries. Ostial stenosis is one of the complications associated with the Cabrol operation. However, there have been no reported cases of acute thrombosis of a Cabrol graft. Here we report a case with acute ST elevation myocardial infarction due to thrombotic total occlusion of a right Cabrol graft-to-right coronary artery (RCA) twelve days after surgery in a patient with Marfan syndrome. He was successfully treated with primary percutaneous coronary intervention (PCI).
PMCID: PMC2877791  PMID: 20514337
Myocardial infarction; Thrombosis; Coronary vessels; Graft occlusion, vascular
20.  Usefulness of Mitral Annular Systolic Velocity in the Detection of Left Ventricular Systolic Dysfunction: Comparison with Three Dimensional Echocardiographic Data 
Although the modified Simpson's method is widely used for the assessment of left ventricular ejection fraction (LVEF), it has limitations including relatively high inter- and intra-observer variability and time consuming nature. We want to evaluate whether assessing mitral annular systolic velocity (S' velocity) by tissue Doppler imaging (TDI) can be used to evaluate LV systolic function with comparing LVEF by three dimensional echocardiography (3DE).
We examined 3DE and TDI studies of patients between January and August 2008. 3DE LVEF was measured by offline commercial computer software EchoPac PC® (GE, Andover, MA, USA). S' velocity was obtained from the medial side with apical four chamber view by pulsed-wave Doppler with TDI.
We included 125 patients (78 males (62.4%), mean age: 57.5±13.0 years). The mean S' velocity was 7.7±1.9 cm/s and the mean LVEF was 57.2±10.4%. The S' velocity measured by TDI showed a linear correlation with LVEF measured by 3DE (r=0.688, p<0.001). Study patients were divided into two groups according to the presence of LV systolic dysfunction: Group I (normal LVEF), n=102 and Group II (LVEF <50%), n=23. For prediction of significant LV systolic dysfunction by the receiver operating characteristic curve according to S' velocity, the optimal cutoff value was 6.8 cm/s. At this cutoff value, the sensitivity and specificity were 94.1% and 87%, respectively.
In this study, S' velocity measured by TDI showed a significant correlation with three dimensional LVEF and can be used to detect patients with LV systolic dysfunction.
PMCID: PMC2889389  PMID: 20661328
Left ventricular function; Mitral annulus systolic velocity; Tissue Doppler imaging; Three-dimensional echocardiography
21.  Catecholamines May Play an Important Role in the Pathogenesis of Transient Mid- and Basal Ventricular Ballooning Syndrome 
Journal of Korean Medical Science  2008;23(5):898-902.
The exact pathogenesis of transient mid- and basal ventricular ballooning, a new variant of transient left ventricular (LV) ballooning, remains unknown. We report two cases of transient mid- and basal ventricular ballooning associated with catecholamines. These cases suggest that catecholamine-mediated myocardial dysfunction might be a potential mechanism of this syndrome.
PMCID: PMC2580003  PMID: 18955801
Ventricular Dysfunction, Left; Catecholamines; Pheochromocytoma
22.  The Epidemiological and Clinical Characteristics of Patients Admitted for Coronary Angiography to Evaluate Ischemic Heart Disease 
Most of the known risk factors associated with ischemic heart disease are based on studies from Western countries; there is only limited information on Korean populations. This study was designed to analyze age related differences in epidemiologic and clinical characteristics in patients who were admitted for coronary angiography for the evaluation of ischemic heart disease.
As part of the multicenter KCAR (Korean Coronary Artery disease Registry) Study, the clinical data of 6,549 patients, who were evaluated at the cardiac catheterization laboratory by coronary angiography, at seven university hospitals in Korea from March 1999 to December 2005, were registered into the KCAR database and analyzed. All patients were divided into three groups according to age: age ≤40, age 41-70 and age ≥71. All demographic and coronary angiographic features were analyzed for the different groups.
The demographic data showed that compared to the older patients young patients ≤40 had a higher prevalence of males and smokers, but a lower prevalence of hypertension, diabetes and prior history of stroke and myocardial infarction. For the lipid profiles, the younger patients had much higher levels of total cholesterol, triglycerides and LDL-cholesterol than the older groups; however, there was no difference in the HDL-cholesterol levels among the three age groups. The most common component of the metabolic syndrome was obesity (79%) in the younger patients and hypertension (92%) in the older patients. The most common reason for presentation was ST-segment elevated myocardial infarction in the younger patients and unstable angina in the older patients.
Ischemic heart disease in younger adults ≤40 had different demographic characteristics and clinical presentation than older patients.
PMCID: PMC2687617  PMID: 17616023
Ischemic heart disease; Epidemiologic study characteristics
23.  The prophylactic use of lamivudine can maintain dose-intensity of adriamycin in hepatitis-B surface antigen (HBs Ag)-positive patients with Non-Hodgkin's lymphoma who receive cytotoxic chemotherapy. 
Journal of Korean Medical Science  2003;18(6):849-854.
We investigated the effectiveness of lamivudine to prevent hepatitis flare up due to reactivation of hepatitis-B virus (HBV) in hepatitis-B surface antigen (HBsAg)-positive patients with Non-Hodgkin's lymphoma (NHL) during cytotoxic chemotherapy. HBsAg-positive patients with NHL were identified from the lymphoma database of the Asan Medical Center from January 1995 to August 2002, and their medical records were reviewed. We found that 31 patients were received cytotoxic chemotherapy among 41 NHL patients with HBsAg-positive during same period. We divided them into 2 groups of HBsAg patients with NHL as follows: Group A who received cytotoxic chemotherapy with lamivudine 100 mg daily; Group B without any prophylactic antiviral therapy. There were no significant differences between Group A and B in several clinical variables. Seventeen patients (85%) in group B and one patient (9%) in Group A had hepatitis due to reactivation of HBV (p<0.001), with one hepatic failure related death in Group B and none in group A. The mean dose intensity of adriamycin actually delivered was 13.3 mg/m2/week (80% Relative Dose intensity (RDI)) in Group A and 9.1 mg/m2/week (55% RDI) in Groups B (p<0.001). Our data suggest that the frequency of chemotherapy-related HBV reactivation may be significantly decreased by lamivudine prophylaxis with maintenance of the dosage of adriamycin.
PMCID: PMC3055150  PMID: 14676442
24.  Efficacy of Cilostazol on Uncontrolled Coronary Vasospastic Angina: A Pilot Study 
Cardiovascular Therapeutics  2013;31(3):179-185.
Although an angina attack by vasospastic angina (VSA) can usually be relieved or controlled with nitrates and calcium channel blockers (CCBs), there are some patients who cannot be controlled even by higher doses and combinations of these drugs. Cilostazol is a selective inhibitor of phosphodiesterase 3 that increases intracellular cyclic adenosine monophosphate (cAMP) contents. A stimulation of cAMP signal transduction increases coronary nitric oxide production. We examined whether cilostazol improved angina symptoms in patients with VSA uncontrolled by conventional treatment.
This study was conducted in a prospective, multicenter, nonrandomized manner. The subject consisted of 21 patients (13 men, 57 ± 9 year-old) who were diagnosed with VSA and had at least two angina attacks during the past 1 week despite of conventional medications such as CCBs and/or nitrates. They took cilostazol 100 mg twice daily for 2 weeks in addition to the conventional medications. The patients recorded the frequency of angina attack and wrote down the numeric rating scale of a "severity of angina attack" while taking conventional medications and cilostazol for 2 weeks, and also recorded an averaged scale or total number of event during the last week at the time of the assessment. Using the Wilcoxon rank-sum test, we compared the changes in the scores of frequency and severity of angina attack before and after adding cilostazol to the conventional medications.
After adding cilostazol to the conventional medications, there were 78.9% relative reduction of the score of angina intensity and 73.5% of angina frequency (P < 0.001). There were four patients (19%) who were forced to stop cilostazol due to headache as an adverse event.
Cilostazol appears to be an effective therapy in VSA uncontrolled with conventional medical treatment. A further prospective, randomized, placebo-controlled study will be needed to validate this result.
PMCID: PMC3654168  PMID: 22953758
Cilostazol; Coronary vasospasm; Treatment

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