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1.  Usefulness of Forward-Viewing Endoscope for Endoscopic Retrograde Cholangiopancreatography in Patients with Billroth II Gastrectomy 
Clinical Endoscopy  2012;45(4):397-403.
Patients undergoing Billroth II (B II) gastrectomy are at higher risk of perforation during endoscopic retrograde cholangiopancreatography (ERCP). We assessed the success rate and safety of forward-viewing endoscopic biliary intervention in patients with B II gastrectomy.
A total of 2,280 ERCP procedures were performed in our institution between October 2008 and June 2011. Of these, forward-viewing endoscopic biliary intervention was performed in 46 patients (38 men and 8 women with B II gastrectomy). Wire-guided selective cannulations of the common bile duct using a standard catheter and guide wire were performed in all patients.
The success rate of afferent loop entrance was 42 out of 46 patients (91.3%) and of biliary cannulation after the approach of the papilla was 42 out of 42 patients (100%). No serious complications were encountered, except for one case of small perforation due to endoscopic sphincterotomy site injury.
When a biliary endoscopist has less experience and patient volume is low, ERCP with a forward-viewing endoscope is preferred because of its ease and safety in all patients with prior B II gastrectomies. Also, forward-viewing endoscope can be used to improve the success rate of biliary intervention in B II patients.
PMCID: PMC3521942  PMID: 23251888
Billroth II gastrectomy; Endoscopic retrograde cholangiopancreatography; Forward-viewing endoscope
2.  Effect of Advanced Glycation End Products on Oxidative Stress and Senescence of Trabecular Meshwork Cells 
To investigate the effect of advanced glycation end products (AGE) on oxidative stress and cellular senescence in cultured human trabecular meshwork cells (HTMC).
Primarily cultured HTMC were exposed to 0, 10, 50, 100, 200 µg/mL of glycated bovine serum albumin (G-BSA) for 5 days. Also co-exposed were L-arginine, sepiapterin, and antioxidant N-acetylcysteine (NAC). Cellular survival and production of nitric oxide (NO), superoxide, and reactive oxygen species were assessed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assay, Griess assay, cytochrome c assay, and dichlorofluorescin diacetate assay, respectively. Senescence-associated β-galactosidase staining was performed to quantify the degree of cellular senescence.
G-BSA decreased cellular survival, NO production, and increased superoxide production significantly in a dose-dependent manner. The effects of G-BSA were abolished with co-exposure of L-arginine, sepiapterin, and NAC. G-BSA enhanced cellular senescence accompanied by increased production of reactive oxygen species. G-BSA-induced cellular senescence was suppressed by application of L-arginine, sepiapterin, and NAC.
AGE enhances cellular senescence of HTMC accompanied with increased oxidative stress. AGE-induced oxidative stress and cellular senescence could be delayed by application of anti-oxidants.
PMCID: PMC3325617  PMID: 22511839
Advanced glycation end products; Aging; Antioxidants; Oxidative stress; Trabecular meshwork cells
3.  Cognitive Impairment in Parkinson's Disease without Dementia: Subtypes and Influences of Age 
Background and Purpose
Cognitive impairments are common in Parkinson's disease (PD), although the severity of these impairments does not significantly impair the patient's daily activities. The aim of this study was to determine the frequency of mild cognitive impairment (MCI) of Parkinson's disease (PDMCI) and its subtypes in nondemented PD patients. We also evaluated the influence of age on the pattern of subtypes of PDMCI.
A total of 141 consecutive, nondemented PD patients underwent a comprehensive neuropsychological assessment covering the five cognitive domains: attention, language, visuospatial, memory, and executive functions. PDMCI was defined as impaired performance in at least one of these five cognitive domains. The influence of age on the distribution of subtypes of PDMCI was assessed by comparing patients in two groups dichotomized according to their age at assessment (younger vs. older).
Fifty-seven (40.4%) of the nondemented PD patients had an impairment in at least one domain, and were therefore considered as having PDMCI. The age at assessment and age at disease onset were significantly higher in the PDMCI patients. The amnestic type of PDMCI was the most frequent, followed by the visuospatial, linguistic, executive, and attention types in that order. The frequency of PDMCI was higher for all subtypes in the older group; the domain that was influenced the most by age was executive function.
MCI was common in PD and the subtypes were diverse. Age was found to be an important risk factor for the development of PDMCI, particularly for the executive subtype. These results indicate that the concept of MCI should be introduced in PD.
PMCID: PMC2760718  PMID: 19826564
Parkinson's disease; mild cognitive impairment; Parkinson's disease dementia
4.  Non-Motor Off Symptoms in Parkinson's Disease 
Journal of Korean Medical Science  2009;24(2):311-314.
The aim of this study is to elucidate the clinical spectrum and frequency of non-motor symptoms during off periods (NMOS) in Parkinson's disease (PD) patients with motor fluctuation. We compared clinical characteristics between PD patients with motor symptoms only (M-off) and those with both motor and non-motor symptoms (NM-off) during off periods. The association of NMOS with parkinsonian clinical characteristics was also investigated. Sixty-seven consecutive PD patients of both M-off and NM-off groups were included in this study. We reviewed medical records, interviewed the patients, and administered a structured questionnaire. NMOS is classified into three categories: autonomic, neuropsychiatric and sensory. The frequency of NMOS and their individual manifestations were assessed. Of 67 patients with off symptoms, 20 were M-off group and 47 NM-off group. Among NMOS, diffuse pain was the most common manifestation, followed by anxiety and sweating. There were no significant differences between M-off and NM-off groups with regard to age, duration of disease and treatment, interval between onset of parkinsonian symptoms and off symptoms and off periods. Patients taking higher dosage of levodopa had fewer NMOS. NMOS is frequent in PD. Comprehensive recognition of NMOS can avoid unnecessary tests and is important for optimal treatment in PD.
PMCID: PMC2672134  PMID: 19399276
Parkinson Disease; Non-Motor Off; Motor Fluctuation
5.  Insulin Enhances Nitric Oxide Production in Trabecular Meshwork Cells via De Novo Pathway for Tetrahydrobiopterin Synthesis 
To investigate the effect of insulin on the production of nitric oxide (NO) in the trabecular meshwork (TM) cells and the enzymatic synthetic pathway of tetrahydrobiopterin (BH4) synthesis.
Primarily cultured human TM cells were exposed to 1, 10, and 100 µg/ml of insulin and 0, 1, 10, 100 and 1000 nM dexamethasone for 3 days. To evaluate the enzymatic pathway of BH4 synthesis, 10 µM dexamethasone, 5 mM diaminopyrimidinone, 100 µM ascorbic acid, 100 µM sepiapterin, or 10 µM methotrexate were also co-administered respectively. Cellular survival and NO production were measured with MTT and Griess assay.
Insulin enhanced NO production in a dose-dependent manner significantly (p<0.05) without affecting cell viability, whereas dexamethasone inhibited NO production. With co-exposure of insulin, diaminopyrimidinone and sepiapterin inhibited insulin-induced NO production. Ascorbic acid increased NO production independent of insulin and methotrexate did not affect to the action of insulin in NO production.
Insulin increases NO production in TM cells via de novo synthetic pathway for BH4 synthesis. Insulin could be involved in the regulation of trabecular outflow by enhancing NO production in TM cells.
PMCID: PMC2629692  PMID: 17460431
Dexamethasone; Insulin; Nitric oxide; Tetrahydrobiopterin; Trabecular meshwork cell
6.  The Efficacy of Exercise Programs for Parkinson's Disease: Tai Chi versus Combined Exercise 
Background and Purpose
Exercise is recommended for every patient with Parkinson's disease (PD). The effectiveness of two different forms of exercise for PD, Tai Chi and combined stretching-strengthening exercise, was compared.
Patients with mild-to-moderate PD were recruited to join either the combined stretching-strengthening exercise group (n=7), the Tai Chi group (n=9), or the control (nonintervention) group (n=7). Exercise was performed three times a week over a period of 8 weeks. The Tai Chi exercise was led by certified instructors based on a Tai-Chi-for-arthritis program. The combined stretching-strengthening exercise comprised folk dancing, stepping, and elastic-band exercises. The subjects' functional fitness, parkinsonian symptoms, quality of life (QoL), and depression were evaluated.
Both exercise groups yielded better results in their overall functional fitness after the intervention. However, no improvement with exercise was found for parkinsonian symptoms, as evaluated using the Unified Parkinson's Disease Rating Scale. With respect to the domains of QoL, the combined stretching-strengthening exercise group fared better in the social domain of QoL, and the Tai Chi group fared better in the emotional domain, while QoL and depression worsened in the control group. The postintervention QoL was improved relative to the control condition only for the Tai Chi group. Although the exercise interventions did not have any effect on depression, the control group was associated with a significant deterioration.
Exercise improved the functional fitness and QoL of PD patients, with Tai Chi yielding better results in QoL and favorable results in functional fitness. These findings suggest that Tai Chi could be a good exercise strategy for patients with PD.
PMCID: PMC3840134  PMID: 24285965
Parkinson's disease; exercise; Tai Chi; quality of life
7.  Peroxisome Proliferator-Activated Receptor Gamma/Signal Transducers and Activators of Transcription 5A Pathway Plays a Key Factor in Adipogenesis of Human Bone Marrow-Derived Stromal Cells and 3T3-L1 Preadipocytes 
Stem Cells and Development  2011;21(3):465-475.
Adipogenesis is largely dependent on the signal transducers and activators of transcription (STAT) pathway. However, the molecular mechanism of the STAT pathway in the adipogenesis of human bone marrow-derived stromal cells (hBMSCs) remains not well understood. The purpose of this research was to characterize the transcriptional regulation involved in expression of STAT5A and STAT5B during adipogenesis in hBMSCs and 3T3-L1 cells. The expression of STAT5A and STAT5B increases with the onset of adipogenesis in hBMSCs and 3T3-L1 cells. The PPAR response elements regulatory element of STAT5A exists at a promoter region ranging from −346 to −101, and the CCAAT/enhancer-binding protein (C/EBP) regulatory element is located at −196 to −118 of the STAT5B promoter. C/EBPβ and C/EBPα bound to the STAT5B promoter region, whereas peroxisome proliferator-activated receptor γ (PPARγ) bound to STAT5A. RNA interference of STAT5A completely blocked differentiation, whereas the inhibition of STAT5B only partially blocked differentiation. We propose that C/EBPα, C/EBPβ, and PPARγ control adipogenesis by regulating STAT5B and STAT5A and that STAT5A is necessary, whereas STAT5B plays a supplementary role during adipogenesis. Further, the regulation of PPARγ-STAT5 by C/EBPβ signaling seems to be the crucial adipogenesis pathway-initiating cascade of the various adipogenic genes.
PMCID: PMC3272248  PMID: 21542777
8.  Predictive factors affecting cecal intubation failure in colonoscopy trainees 
Successful cecal intubation (SCI) is not only a quality indicator but also an important marker in a colonoscopy trainee’s progress. We conducted this study to determine factors predicting SCI in colonoscopy trainees, and to compare these factors before and after trainees achieve technical competence.
Design of this study was a cross-sectional studies of two time series design for one year at a single center. From March 2011 to February 2012, a total 2,050 subjects who underwent colonoscopy by four first-year gastrointestinal fellows were enrolled at Christian hospital, Wonju, Republic of Korea. Four gastrointestinal fellows have filled out the colonoscopic documentation. Main outcome measurement was predictive factors affecting cecal intubation failure and learning curves.
Colonoscopy was successfully completed to the cecum in 1,720 patients (83.9%). Success rates gradually increased as trainees performed more colonoscopies: the rate of SCI was 62% in the first 50 cases, and grew to 93% by the 250th case. Logistic regression analysis of factors affecting cecal intubation failure showed that female gender, low BMI (BMI < 18.5 kg/m2), poor bowel preparation, and past history of stomach surgery were more often associated with cecal intubation failure, particularly before the trainees achieved technical competence.
Several patient characteristics were identified that may predict difficulty of cecal intubation in colonoscopy trainees. Particularly, low BMI, inadequate bowel cleansing, and previous stomach operation were predictors of cecal intubation failure before the trainees have reached technical competency. The results could be informative so that trainees enhance the success rate regarding better colonoscopy training programs.
PMCID: PMC3560110  PMID: 23331720
9.  Translation and Validation of the Korean Version of the 39-Item Parkinson's Disease Questionnaire 
Background and Purpose
The importance of health-related quality of life (HrQoL) has been increasingly emphasized when assessing and providing treatment to patients with chronic, progressive, degenerative disorders. The 39-item Parkinson's disease questionnaire (PDQ-39) is the most widely used patient-reporting scale to assess HrQoL in Parkinson's disease (PD). This study evaluated the validity and reliability of the translated Korean version of the PDQ-39 (K-PDQ-39).
One hundred and two participants with PD from 10 movement disorder clinics at university-affiliated hospitals in South Korea completed the K-PDQ-39. All of the participants were also tested using the Unified Parkinson's Disease Rating Scale (UPDRS), Korean version of the Mini-Mental State Examination (K-MMSE), Korean version of the Montgomery-Asberg Depression Scale (K-MADS), Epworth Sleepiness Scale (ESS) and non-motor symptoms scale (NMSS). Retests of the K-PDQ-39 were performed over time intervals from 10 to 14 days in order to assess test-retest reliability.
Each K-PDQ-39 domain showed correlations with the summary index scores (rS=0.559-0.793, p<0.001). Six out of eight domains met the acceptable standard of reliability (Cronbach's α coefficient ≥0.70). The Guttman split-half coefficient value of the K-PDQ-39 summary index, which is an indicator of test-retest reliability, was 0.919 (p<0.001). All of the clinical variables examined except for age, comprising disease duration, levodopa equivalent dose, modified Hoehn and Yahr stage (H&Y stage), UPDRS part I, II and III, mood status (K-MADS), cognition (K-MMSE), daytime sleepiness (ESS) and (NMSS) showed strong correlations with the K-PDQ-39 summary index (p<0.01).
The K-PDQ-39 has been validated for use in the Korean-speaking PD population. The questionnaire is a valid and reliable assessment tool for assessing the HrQoL of Korean PD patients.
PMCID: PMC3543906  PMID: 23346157
Parkinson's disease; quality of life; validation
10.  Toxic Encephalopathy 
Safety and Health at Work  2012;3(4):243-256.
This article schematically reviews the clinical features, diagnostic approaches to, and toxicological implications of toxic encephalopathy. The review will focus on the most significant occupational causes of toxic encephalopathy. Chronic toxic encephalopathy, cerebellar syndrome, parkinsonism, and vascular encephalopathy are commonly encountered clinical syndromes of toxic encephalopathy. Few neurotoxins cause patients to present with pathognomonic neurological syndromes. The symptoms and signs of toxic encephalopathy may be mimicked by many psychiatric, metabolic, inflammatory, neoplastic, and degenerative diseases of the nervous system. Thus, the importance of good history-taking that considers exposure and a comprehensive neurological examination cannot be overemphasized in the diagnosis of toxic encephalopathy. Neuropsychological testing and neuroimaging typically play ancillary roles. The recognition of toxic encephalopathy is important because the correct diagnosis of occupational disease can prevent others (e.g., workers at the same worksite) from further harm by reducing their exposure to the toxin, and also often provides some indication of prognosis. Physicians must therefore be aware of the typical signs and symptoms of toxic encephalopathy, and close collaborations between neurologists and occupational physicians are needed to determine whether neurological disorders are related to occupational neurotoxin exposure.
PMCID: PMC3521923  PMID: 23251840
Occupational diseases; Nervous system diseases; Toxic encephalopathy
11.  Validation of the Korean-Version of the Nonmotor Symptoms Scale for Parkinson's Disease 
Background and Purpose
Non-motor symptoms are common in Parkinson's disease (PD), and are the primary cause of disability in many PD patients. Our aim in this study was to translate the origin non-motor symptoms scale for PD (NMSS), which was written in English, into Korean (K-NMSS), and to evaluate its reliability and validity for use with Korean-speaking patients with PD.
In total, 102 patients with PD from 9 movement disorders sections of university teaching hospitals in Korea were enrolled in this study. They were assessed using the K-NMSS, the Unified Parkinson's Disease Rating Scale (UPDRS), the Korean version of the Mini-Mental Status Examination (K-MMSE), the Korean version of the Montgomery-Asberg Depression Rating Scale (K-MADS), the Epworth Sleepiness Scale (ESS), and Parkinson's Disease Questionnaire 39 (PDQ39). Test-retest reliability was assessed over a time interval of 10-14 days in all but one patient.
The K-NMSS was administered to 102 patients with PD. The internal consistency and reliability of this tool was 0.742 (mean Cronbach's α-coefficient). The test-retest correlation reliability was 0.941 (Guttman split-half coefficient). There was a moderate correlation between the total K-NMSS score and the scores for UPDRS part I [Spearman's rank correlation coefficient, (rS)=0.521, p<0.001] and UPDRS part II (rS=0.464, p=0.001), but there was only a weak correlation between the total K-NMSS score and the UPDRS part III score (rS=0.288, p=0.003). The total K-NMSS score was significantly correlated with the K-MADS (rS=0.594, p<0.001), K-MMSE (rS=-0.291, p=0.003), and ESS (rS=0.348, p<0.001). The total K-NMSS score was also significantly and positively correlated with the PDQ39 score (rS=0.814, p<0.001).
The K-NMSS exhibited good reliability and validity for the assessment of non-motor symptoms in Korean PD patients.
PMCID: PMC3540287  PMID: 23323136
Parkinson's disease; non-motor symptoms scale; validation
12.  Elevated Levels of α-Synuclein Oligomer in the Cerebrospinal Fluid of Drug-Naïve Patients with Parkinson's Disease 
Background and Purpose
The detection of α-synuclein in the body fluids of patients with synucleinopathy has yielded promising but inconclusive results, in part because of conformational changes of α-synuclein in response to environmental conditions. The aim of this study was to determine the feasibility of using α-synuclein as a biological marker for Parkinson's disease (PD).
Twenty-three drug-naïve patients with PD (age 62.4±12.7 years, mean±SD; 11 males) and 29 age- and sex-matched neurologic control subjects (age 60.1±16.2 years; 16 males) were recruited. The levels of oligomeric and total α-synuclein in the cerebrospinal fluid (CSF) and plasma were measured using two simultaneous enzyme-linked immunosorbent assays.
The level of α-synuclein oligomer in the CSF of PD patients was significantly higher in PD patients than in neurological controls, but other findings (plasma α-synuclein oligomer and total α-synuclein in CSF and plasma) did not differ significantly between the two groups. When the control subjects were divided into a symptomatic control group (11 patients who complained of parkinsonian symptoms and were diagnosed with hydrocephalus and drug-induced or vascular parkinsonism) and a neurologic control group (10 normal subjects and 8 patients with diabetic ophthalmoplegia), the level of α-synuclein oligomer in the CSF was still significantly higher in PD patients than in both of the control subgroups.
These findings provide further evidence for a pathogenic role of the α-synuclein oligomer and suggest that CSF levels of α-synuclein oligomer can be a reliable marker for PD.
PMCID: PMC3259496  PMID: 22259618
Parkinson's disease; cerebrospinal fluid; alpha-synuclein; enzyme-linked immunosorbent assay
13.  Clinical Outcomes and Risk Factors of Rebleeding Following Endoscopic Therapy for Nonvariceal Upper Gastrointestinal Hemorrhage 
Clinical Endoscopy  2011;44(2):93-100.
Rebleeding after endoscopic therapy for non-variceal upper gastrointestinal hemorrhage (NGIH) is the most important predictive factor of mortality. We evaluated the risk factors of rebleeding in patients undergoing endoscopic therapy for the NGIH.
Between January 2003 and January 2007, 554 bleeding events in 487 patients who underwent endoscopic therapy for NGIH were retrospectively enrolled. We reviewed the clinicoendoscopical characteristics of patients with rebleeding and compared them with those of patients without rebleeding.
The incidence of rebleeding was 21.7% (n=120). In the multivariate analysis, initial hemoglobin level ≤9 g/dL (p=0.002; odds ratio [OR], 2.433), inexperienced endoscopist with less than 2 years of experience in therapeutic endoscopy (p=0.001; OR, 2.418), the need for more 15 cc of epinephrine (p=0.001; OR, 2.570), injection therapy compared to thermal and injection therapy (p=0.001; OR, 2.840), and comorbidity with chronic renal disease (p=0.004; OR, 2.908) or liver cirrhosis (p=0.010; OR, 2.870) were risk factors for rebleeding following endoscopic therapy.
Together with patients with low hemoglobin level at presentation, chronic renal disease, liver cirrhosis, the need for more 15 cc of epinephrine, or therapy done by inexperienced endoscopist were risk factors for the development of rebleeding.
PMCID: PMC3363058  PMID: 22741119
Gastrointestinal hemorrhage; Risk factors; Endoscopy; Therapy
14.  Overnight switch from ropinirole to transdermal rotigotine patch in patients with Parkinson disease 
BMC Neurology  2011;11:100.
A recent trial involving predominantly Caucasian subjects with Parkinson Disease (PD) showed switching overnight from an oral dopaminergic agonist to the rotigotine patch was well tolerated without loss of efficacy. However, no such data have been generated for Korean patients.
This open-label multicenter trial investigated PD patients whose symptoms were not satisfactorily controlled by ropinirole, at a total daily dose of 3 mg to 12 mg, taken as monotherapy or as an adjunct to levodopa. Switching treatment from oral ropinirole to transdermal rotigotine was carried out overnight, with a dosage ratio of 1.5:1. After a 28-day treatment period, the safety and tolerability of switching was evaluated. Due to the exploratory nature of this trial, the effects of rotigotine on motor and nonmotor symptoms of PD were analyzed in a descriptive manner.
Of the 116 subjects who received at least one treatment, 99 (85%) completed the 28-day trial period. Dose adjustments were required for 11 subjects who completed the treatment period. A total of 76 treatment-emergent adverse events (AEs) occurred in 45 subjects. No subject experienced a serious AE. Thirteen subjects discontinued rotigotine prematurely due to AEs. Efficacy results suggested improvements in both motor and nonmotor symptoms and quality of life after switching. Fifty-two subjects (46%) agreed that they preferred using the patch over oral medications, while 31 (28%) disagreed.
Switching treatment overnight from oral ropinirole to transdermal rotigotine patch, using a dosage ratio of 1.5:1, was well tolerated in Korean patients with no loss of efficacy.
Trial registration
This trial is registered with the Registry (NCT00593606).
PMCID: PMC3166898  PMID: 21831297
15.  Fulminant Epstein-Barr Virus-associated T-cell Lymphoproliferative Disorder in an Immunocompetent Middle-aged Man Presenting with Chronic Diarrhea and Gastrointestinal Bleeding 
Journal of Korean Medical Science  2011;26(8):1103-1107.
The World Health Organization (WHO) recently defined systemic Epstein-Barr virus (EBV)-positive T-cell lymphoproliferative disorders (LPD) of childhood as a life-threatening illness. However, this rare disease has not been extensively studied. Here we report a case of systemic EBV-positive T-cell LPD in a previously healthy middle-aged man with a chief complaint of chronic diarrhea. The initial colon biopsy showed focal infiltration of EBV-positive small lymphocytes without any atypia. However, the disease rapidly progressed and the patient required a total colectomy due to severe gastrointestinal bleeding. Three and half months after admission, the patient died from a complication of disseminated intravascular coagulation. The resected colon showed diffuse infiltration of EBV-positive atypical lymphocytes with ischemic change. Most atypical lymphocytes were CD3+ or CD5+. The monoclonality of EBV was demonstrated by sequence variation analysis of the latent membrane protein 1 (LMP1) gene in the colectomy specimen as well as in the initial biopsy.
PMCID: PMC3154349  PMID: 21860564
Epstein-Bar Virus Infections; Lymphoproliferatife Disorders; Atypical T-cell Proliferation
16.  Upgrade of Lesions Initially Diagnosed as Low-Grade Gastric Dysplasia upon Forceps Biopsy Following Endoscopic Resection 
Gut and Liver  2011;5(2):187-193.
Gastric dysplasia is generally accepted to be the precursor lesion of gastric carcinoma. Approximately 25% to 35% of histological diagnoses based on endoscopic forcep biopsies for gastric dysplastic lesions change following endoscopic resection (ER). The aim of this study was to determine the predictive endoscopic features of high-grade gastric dysplasia (HGD) or early gastric cancer (EGC) following ER for lesions initially diagnosed as low-grade dysplasia (LGD) by a forceps biopsy.
To determine predictive variables for upgraded histology (LGD to HGD or EGC). The lesion size, gross endoscopic appearance, location, and surface nodularity or redness as well as the presence of a depressed portion, Helicobacter pylori infection, and intestinal metaplasia were retrospectively investigated.
Among 251 LGDs diagnosed by an initial forceps biopsy, the diagnoses of 100 lesions (39.8%) changed following the ER; 56 of 251 LGDs (22.3%) were diagnosed as HGD, 39 (15.5%) as adenocarcinoma, and 5 (2.0%) as chronic gastritis. In a univariate analysis, large lesions (>15 mm), those with a depressed portion, and those with surface nodularity were significantly correlated with a upgraded histology classification following ER. In a multivariate analysis, a large size (>15 mm; odds ratio [OR], 2.8; 95% confidence interval [CI], 1.46 to 5.43) and a depressed portion in the lesion (OR, 2.7; 95% CI, 1.44 to 5.03) were predictive factors for upgraded histology following ER.
Our study shows that a substantial proportion of diagnoses of low-grade gastric dysplasias based on forceps biopsies were not representative of the entire lesion. We recommend ER for lesions with a depressed portion and for those larger than 15 mm.
PMCID: PMC3140664  PMID: 21814599
Gastric dysplasia; Endoscopic forcep biopsy; Endoscopic resection; Early gastric cancer
17.  Dementia with Lewy Bodies versus Alzheimer's Disease and Parkinson's Disease Dementia: A Comparison of Cognitive Profiles 
Background and Purpose
It is particularly difficult to differentiate dementia with Lewy bodies (DLB) from the related dementias of Alzheimer's disease (AD) and Parkinson's disease dementia (PDD). Few studies have been designed to comparatively analyze detailed neuropsychological assessments of DLB patients and patients with AD and PDD.
Three groups of patients participated in this study: 10 with DLB, 76 with AD, and 17 with PDD, who had been diagnosed as probable DLB, AD, and PDD, respectively, according to the clinical criteria of the consortium on DLB, National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorder Association, and the clinical diagnostic criteria for PDD. All patients were evaluated by careful neurological examination with detailed neuropsychological testing.
Significant differences among the three groups were found for attention, memory, and executive function, which included tasks of backward digit span, three-word recall, verbal delayed recall, and the Stroop test. Post hoc analysis revealed that the deficiencies of attention on the digit span task were greater in the DLB group than in the AD and PDD groups. The scores for episodic verbal memory tasks were significantly lower in the DLB and AD groups than in the PDD group. The performance in frontal executive function, as indicated by the Stroop test, was significantly worse in the DLB and PDD groups than in the AD group.
The results of the present study show that the pattern of cognitive dysfunction, in terms of attention, episodic memory, and executive functions, differ between patients with DLB and patients with AD and PDD.
PMCID: PMC3079155  PMID: 21519522
dementia with lewy bodies; Alzheimer's disease; Parkinson's disease dementia; cognition; neuropsychology
18.  Development and Application of Bovine and Porcine Oligonucleotide Arrays with Protein-Based Annotation 
The design of oligonucleotide sequences for the detection of gene expression in species with disparate volumes of genome and EST sequence information has been broadly studied. However, a congruous strategy has yet to emerge to allow the design of sensitive and specific gene expression detection probes. This study explores the use of a phylogenomic approach to align transcribed sequences to vertebrate protein sequences for the detection of gene families to design genomewide 70-mer oligonucleotide probe sequences for bovine and porcine. The bovine array contains 23,580 probes that target the transcripts of 16,341 genes, about 72% of the total number of bovine genes. The porcine array contains 19,980 probes targeting 15,204 genes, about 76% of the genes in the Ensembl annotation of the pig genome. An initial experiment using the bovine array demonstrates the specificity and sensitivity of the array.
PMCID: PMC3010673  PMID: 21197395
19.  Complete Endoscopic Resection of Very Early Stage Gastric Plasmacytoma 
Gut and Liver  2010;4(4):547-550.
Gastric plasmacytomas are very rare, and most are not detected until the disease has progressed to an advanced stage. However, there have been recent reports of cases of early-stage gastric plasmacytoma, in which neoplastic cells are confined to the mucosa or submucosa. Here we report a case of a very early stage gastric plasmacytoma that was confined to the lamina propria of the gastric mucosa. The lesion was successfully and completely removed by endoscopic submucosal dissection, and the surveillance endoscopy showed no recurrence during the follow-up of 40 months. This report appears to be the first documented case of complete endoscopic removal of a primary gastric plasmacytoma.
PMCID: PMC3021614  PMID: 21253307
Plasmacytoma; Endoscopic submucosal dissection
20.  Selective Susceptibility of Human Dopaminergic Neural Stem Cells to Dopamine-Induced Apoptosis 
Experimental Neurobiology  2010;19(3):155-164.
Dysfunctions of ubiquitin-proteasome system and toxicity of dopamine have been known as the key mechanisms in the pathogenesis of Parkinson's disease (PD) and proteasome inhibitors are widely used in experimental models of PD to reproduce cell death of dopaminergic neurons. In the present study, immortalized human neural stem cells (HB1.F3, F3) and those transfected with human aromatic acid decarboxylase gene (F3.AADC), were used to investigate the mechanism of selective dopaminergic neuronal cell death mediated by dopamine or proteasome inhibitors. Flow cytometric analysis revealed that F3.AADC was more susceptible to dopamine than parental F3 cell which does not carry dopaminergic phenotype. The dopamine-induced apoptosis was mediated by activation of caspases 3 and 9 and cleavage of PARP. Proteasome inhibitors also induced apoptosis in dose-dependent manner but there was no difference between cell types. Prolonged exposure to subtoxic dose of proteasome inhibitors further enhanced dopamine-induced apoptosis in the F3.AADC, and increased presence of alpha-synuclein and ubiquitin-positive inclusions was noted in the cytoplasm of apoptotic cells by immunocytochemistry. These findings indicate that dopaminergic cells are selectively susceptible to dopamine toxicity and prolonged suppression of proteasome system further enhances selective sensitivity to dopamine toxicity. Chronic subtoxic proteasomal dysfunction of dopaminergic cells might contribute to selective cell death of dopaminergic neurons during the pathogenesis of Parkinson's disease.
PMCID: PMC3214785  PMID: 22110355
Parkinson's disease; proteasome; dopamine; apoptosis; human neural stem cells
21.  Dobutamine stress echocardiography for evaluating cirrhotic cardiomyopathy in liver cirrhosis 
The Korean Journal of Hepatology  2010;16(4):376-382.
The blunted ventricular systolic and diastolic contractile responses to physical and pharmacological stress in cirrhosis are termed cirrhotic cardiomyopathy (CCM). CCM has been known to involve multiple defects in the β-adrenergic signaling pathway. The aim of this study was to determine whether cirrhotic patients have blunted cardiac responses to catecholamine stimulation through dobutamine stress echocardiography (DSE).
Seventy-one cirrhotic patients with normal left ventricular (LV) chamber size and ejection fraction were enrolled. The LV systolic and diastolic functions were evaluated by two-dimensional and Doppler echocardiography at rest and during peak dobutamine infusion (40 µg/kg/min). An abnormal response was defined as a decrease of less than 10% in LV end-diastolic volume, a decrease of less than 20% in end-systolic volume, and an increase of less than 10% in LV ejection fraction (EF) at peak dobutamine infusion, based on previously used criteria. The early/late diastolic flow (E/A) ratio and diastolic parameters were also measured.
A blunted LV response to dobutamine was observed in 18 of 71 cirrhotic patients (25.4%). The baseline EF was significantly higher in 18 patients with a blunted DSE response than that of those with a normal DSE response (P<0.05). The baseline and peak E/A ratios, which are common diastolic dysfunction markers, were higher in the cirrhosis group than in the control group (P<0.001). No adverse events associated with DSE were observed.
Blunted cardiac responses to dobutamine stimulation, which are implicated in defects in the β-adrenergic signaling pathway, might contribute to the pathogenesis of CCM in patients with cirrhosis.
PMCID: PMC3304603  PMID: 21415581
Cirrhotic cardiomyopathy; Dobutamine stress echocardiography; Liver cirrhosis
22.  Prehospital Notification from the Emergency Medical Service Reduces the Transfer and Intra-Hospital Processing Times for Acute Stroke Patients 
Background and Purpose
There is little information available about the effects of Emergency Medical Service (EMS) hospital notification on transfer and intrahospital processing times in cases of acute ischemic stroke.
This study retrospectively investigated the real transfer and imaging processing times for cases of suspected acute stroke (AS) with EMS notification of a requirement for intravenous (IV) tissue-type plasminogen activator (t-PA) and for cases without notification. Also we compared the intra-hospital processing times for receiving t-PA between patients with and without EMS prehospital notification.
Between December 2008 and August 2009, the EMS transported 102 patients with suspected AS to our stroke center. During the same period, 33 patients received IV t-PA without prehospital notification from the EMS. The mean real transfer time after the EMS call was 56.0±32.0 min. Patients with a transfer distance of more than 40 km could not be transported to our center within 60 min. Among the 102 patients, 55 were transferred via the EMS to our emergency room for IV t-PA. The positive predictive value for stroke (90.9% vs. 68.1%, p=0.005) was much higher and the real transfer time was much faster in patients with an EMS t-PA call (47.7±23.1 min, p=0.004) than in those without one (56.3±32.4 min). The door-to-imaging time (17.8±11.0 min vs. 26.9±11.5 min, p=0.01) and door-to-needle time (29.7±9.6 min vs. 42.1±18.1 min, p=0.01) were significantly shorter in the 18 patients for whom there was prehospital notification and who ultimately received t-PA than in those for whom there was no prehospital notification.
Our results indicate that prehospital notification could enable the rapid dispatch of AS patients needing IV t-PA to a stroke centre. In addition, it could reduce intrahospital delays, particularly, imaging processing times.
PMCID: PMC2950918  PMID: 20944814
stroke; thrombolysis; prehospital notification; stroke care system
23.  In vitro Antibacterial and Morphological Effects of the Urushiol Component of the Sap of the Korean lacquer tree (Rhus vernicifera Stokes) on Helicobacter pylori 
Journal of Korean Medical Science  2010;25(3):399-404.
Eradication regimens for Helicobacter pylori infection have some side effects, compliance problems, relapses, and antibiotic resistance. Therefore, alternative anti-H. pylori or supportive antimicrobial agents with fewer disadvantages are necessary for the treatment of H. pylori. We investigated the pH-(5.0, 6.0, 7.0, 8.0, 9.0, and 10.0) and concentration (0.032, 0.064, 0.128, 0.256, 0.514, and 1.024 mg/mL)-dependent antibacterial activity of crude urushiol extract from the sap of the Korean lacquer tree (Rhus vernicifera Stokes) against 3 strains (NCTC11637, 69, and 219) of H. pylori by the agar dilution method. In addition, the serial (before incubation, 3, 6, and 10 min after incubation) morphological effects of urushiol on H. pylori were examined by electron microscopy. All strains survived only within pH 6.0-9.0. The minimal inhibitory concentrations of the extract against strains ranged from 0.064 mg/mL to 0.256 mg/mL. Urushiol caused mainly separation of the membrane, vacuolization, and lysis of H. pylori. Interestingly, these changes were observed within 10 min following incubation with the 1×minimal inhibitory concentrations of urushiol. The results of this work suggest that urushiol has potential as a rapid therapeutic against H. pylori infection by disrupting the bacterial cell membrane.
PMCID: PMC2826732  PMID: 20191039
Urushiol; Helicobacter pylori; Anti-Infective Agents
24.  A Case of Gerstmann-Sträussler-Scheinker Disease 
Gerstmann-Sträussler-Scheinker disease (GSS) is a type of human transmissible spongiform encephalopathy (TSE) that is determined genetically.
Case Report
A 46-year-old woman presented with a slowly progressive ataxic gait and cognitive decline. She was alert but did not cooperate well due to severe dementia and dysarthria. High signal intensities in the cerebral cortices were evident in MRI, especially in diffusion-weighted images (DWI). A prion protein gene (PRNP) analysis revealed a P102L (proline-to-leucine) mutation in codon 102.
This is the first reported case of GSS (confirmed by PRNP analysis) in Korea. Distinctive MRI findings are also presented.
PMCID: PMC2851297  PMID: 20386644
Gerstmann-Sträussler-Scheinker disease; transmissible spongiform encephalopathy; diffusion-weighted imaging
25.  Temporal profiling of the adipocyte proteome during differentiation using a 5-plex SILAC based strategy 
Journal of proteome research  2009;8(1):48-58.
The adipose tissue has important secretory and endocrine functions in humans. The regulation of adipocyte differentiation has been actively pursued using transcriptomic methods over the last several years. Quantitative proteomics has emerged as a promising approach to obtain temporal profiles of biological processes such as differentiation. Stable isotope labeling with amino acids in cell culture (SILAC) is a simple and robust method for labeling proteins in vivo. Here, we describe the development and application of a five-plex SILAC experiment using four different heavy stable isotopic forms of arginine to study the nuclear proteome and the secretome during the course of adipocyte differentiation. Tandem mass spectrometry analysis using a quadrupole time-of-flight instrument resulted in identification of a total 882 proteins from these two proteomes. Of these proteins, 427 were identified on the basis of one or more arginine containing peptides that allowed quantitation. In addition to previously reported molecules that are differentially expressed during the process of adipogenesis (e.g. adiponectin and lipoprotein lipase), we identified several proteins whose differential expression during adipocyte differentiation has not been documented previously. For example, THO complex 4, a context-dependent transcriptional activator in the T-cell receptor alpha enhancer complex, showed highest expression at middle stage of adipogenesis while SNF2 alpha, a chromatin remodeling protein, was downregulated upon initiation of adipogenesis and remained so during subsequent time points. This study using a 5-plex SILAC to investigate dynamics illustrates the power of this approach to identify differentially expressed proteins in a temporal fashion.
PMCID: PMC2642533  PMID: 18947249
Adipocyte; adipogenesis; proteomics; SILAC

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