Hee-Yeon Jung

The prevalence of and risk factors for erosive oesophagitis and non-erosive reflux disease: a nationwide multicentre prospective study in Korea

Background  Prospective nationwide multicentre studies that have evaluated endoscopic findings and reflux symptoms using a well‐designed questionnaire are very rare.

Activation of PERK Signaling Attenuates Aβ-Mediated ER Stress

Alzheimers disease (AD) is characterized by the deposition of aggregated beta-amyloid (Aβ), which triggers a cellular stress response called the unfolded protein response (UPR). The UPR signaling pathway is a cellular defense system for dealing with the accumulation of misfolded proteins but switches to apoptosis when endoplasmic reticulum (ER) stress is prolonged. ER stress is involved in neurodegenerative diseases including AD, but the molecular mechanisms of ER stress-mediated Aβ neurotoxicity still remain unknown. Here, we show that treatment of Aβ triggers the UPR in the SK-N-SH human neuroblastoma cells. Aβ mediated UPR pathway accompanies the activation of protective pathways such as Grp78/Bip and PERK-eIF2α pathway, as well as the apoptotic pathways of the UPR such as CHOP and caspase-4. Knockdown of PERK enhances Aβ neurotoxicity through reducing the activation of eIF2α and Grp8/Bip in neurons. Salubrinal, an activator of the eIF2α pathway, significantly increased the Grp78/Bip ER chaperone resulted in attenuating caspase-4 dependent apoptosis in Aβ treated neurons. These results indicate that PERK-eIF2α pathway is a potential target for therapeutic applications in neurodegenerative diseases including AD.

Intraoperative gastroscopy for gastric surgery.

Background:Few reports are available on the use of intraoperative gastroscopy for gastric surgery.Methods:The details of 33 patients (25 early gastric cancers and eight gastric submucosal tumors) who underwent intraoperative gastroscopy from June 2003 to June 2004 were analyzed. The type of operation or resection margin was determined by evaluating both sides of the stomach simultaneously by combined operative and gastroscopic methods.Results:Preoperative endoscopic clipping was done preferentially for early gastric cancer. However, when precise localization was needed, intraoperative gastroscopy was used. Curative gastric resection was possible in 25 early gastric cancer patients after accurate lesion localization. Laparoscopic wedge resections of submucosal tumors were performed in seven patients without stenosis by combined laparoscopic and gastroscopic methods.Conclusions:Intraoperative gastroscopy can be used effectively during gastric surgery for early gastric cancer or submucosal tumors and can be regarded as a modern stethoscope to gastric surgeons.

Illiteracy and the incidence of Alzheimer's disease in the Yonchon County survey, Korea

BACKGROUND This study aims to establish the incidence rates of Alzheimers disease (AD) and to understand the relations between illiteracy and AD in the Korean Yonchon survey cohort. METHODS A community-based, dementia-free cohort of 966 people aged 65 years and older was followed up for an average of 5.4 +/- 1.60 years to detect incident AD cases using a two-phase procedure. Age-specific incidence rates were calculated using a person-years approach with Poisson distribution confidence intervals. Data were analyzed using the Cox proportional hazards model to find the hazard ratio of illiteracy. RESULTS The participating percentage of the survivors was 86.4% and 74 subjects were diagnosed with AD. Incidence rates per 1000 person-years were 20.99 (95% CI 16.48 to 26.35) for AD. The hazard ratio of illiteracy was 1.78 (95% CI 1.08 to 2.93) adjusted for age, sex, educational level. AD developed more rapidly with aging in the illiterate group than in the literate group. CONCLUSIONS Illiteracy is associated with a higher risk of AD and the risk increases with age.

The Effect of Repeated Virtual Nicotine Cue Exposure Therapy on the Psychophysiological Responses: A Preliminary Study

Objective Smoking related cues may elicit smoking urges and psychophysiological responses in subjects with nicotine dependence. This study aimed to investigate the effect of repeated virtual cue exposure therapy using the surround-screen based projection wall system on the psychophysiological responses in nicotine dependence. Methods The authors developed 3-dimensional neutral and smoking-related environments using virtual reality (VR) technology. Smoking-related environment was a virtual bar, which comprised both object-related and social situation cues. Ten subjects with nicotine dependence participated in 4-week (one session per week) virtual cue exposure therapy. Psychophysiological responses [electromyography (EMG), skin conductance (SC), and heart rate] and subjective nicotine craving were acquired during each session. Results VR nicotine cue elicited greater psychophysiological responses and subjective craving for smoking than did neutral cue, and exposure to social situation cues showed greater psychophysiological responses in SC and EMG than did object-related cues. This responsiveness decreased during the course of repeated therapy. Conclusion The present study found that both psychophysiological responses and subjective nicotine craving were greater to nicotine cue exposure via projection wall VR system than to neutral cues and that enhanced cue reactivity decreased gradually over the course of repeated exposure therapy. These results suggest that VR cue exposure therapy combined with psychophysiological response monitoring may be an alternative treatment modality for smoking cessation, although the current findings are preliminary.

Increased motility of Helicobacter pylori by methylcellulose could upregulate the expression of proinflammatory cytokines in human gastric epithelial cells

The inflammatory reaction in the human gastric mucosa to Helicobacter pylori could be initially triggered by an array of cytokines expressed in infected gastric epithelial cells. The spiral morphology and flagella of these organisms could increase their velocity in a viscous environment such as methylcellulose solution. The goal of this study was to determine whether modification of H. pylori motility could influence the expression of cytokine genes from gastric epithelial cells infected with H. pylori. Adherent human gastric epithelial cells were cultured and overlaid with methylcellulose solutions of varying viscosity. These epithelial cell layers covered with methylcellulose solution were inoculated with H. pylori. RNAs were then extracted from the gastric epithelial cells. Various cytokine gene expressions were assessed and quantified by reverse transcription-polymerase chain reaction (RT-PCR) and standard synthetic RNA. Cytokine proteins were also measured by enzyme-linked immunosorbent assay (ELISA). Expression of mRNA for interleukin(IL)-8 was upregulated in H. pylori-infected gastric epithelial cells overlaid with methylcellulose of 15 centipoise (cp) viscosity. The expression of mRNA for IL-1 alpha, IL-8, monocyte chemotactic protein (MCP)-1 and granulocyte macrophage colony-stimulating factor (GM-CSF) was also upregulated in H. pylori-infected gastric epithelial cells overlaid with methylcellulose solution of the same viscosity. The number of molecules of the expressed cytokine transcripts also paralleled the amounts of protein secreted from gastric epithelial cells infected with H. pylori. These results suggest that methylcellulose solution (simulating the mucus layer in vivo) could increase contact of H. pylori with gastric epithelial cells by increasing its motility. This could result in the upregulation of mRNA for proinflammatory cytokines in gastric epithelial cells, therefore enhancing inflammatory reaction at H. pylori-infected sites.

spatial memory impairments in amnestic mild cognitive impairment in a virtual radial arm maze

Objective This study aims to apply the virtual radial arm maze (VRAM) task to find spatial working memory and reference memory impairments in patients of amnestic mild cognitive impairment (aMCI) and Alzheimer’s disease (AD). Spatial memory functions between aMCI converters and nonconverters are also compared using VRAM results. Methods We assessed the spatial memory in 20 normal controls, 20 aMCI, and 20 mild AD subjects using VRAM. The Mini-Mental State Examination, Clinical Dementia Rating scale, and other neuropsychological tests were given to the subjects in conjunction with the VRAM test. Scores in working memory errors and reference memory errors were compared among the three groups using repeated measures analysis of variance. In addition, aMCI patients were followed-up after 5 years and surveyed for AD conversion rate. Results In AD patients, both spatial working and reference memory were impaired. However, in aMCI subjects, only spatial reference memory was impaired. Significant spatial reference memory impairment was found in the aMCI converter group when compared to the nonconverter group. Conclusion Spatial working memory is less impaired in aMCI while reference memory is similarly damaged in AD. In aMCI patients, more severe spatial reference memory deficit is a neuropsychological marker for AD conversion. VRAM may be well utilized in humans to assess spatial memory in normal aging, in aMCI, and in AD.

The model of the relationships among the predictors of quality of life in chronic stage of schizophrenia

We attempted to formulate a model of quality of life (QoL) in chronic stage of schizophrenia with 72 patients by including key variables, i.e., psychopathology, insight, executive functioning, and side effects, proposed to be its significant predictors in previous studies. We applied the structural equation modelling (SEM) method to simultaneously test a number of possible hypotheses concerning the inter-relations among the predictors of QoL in schizophrenia patients by formulating possible models and examining their levels of fitness. Our most fit model (X(2)=2.106, df=4, P=0.716; CFI=1.000; TLI=1.213; RMSEA=0.000, LO=0.000, HI=0.132) showed that the severity of psychopathology not only directly causes poor QoL, but also by adversely affecting insight. On the other hand, executive function may not be affected significantly by psychopathology, but executive function still plays an important role in determining the QoL not only directly, but also indirectly by influencing self-evaluation of side-effects. Impaired insight and executive function caused by severe level of psychopathology contribute to an increased reporting of side-effects, resulting in cumulative dysfunction in daily life for patients with chronic schizophrenia. Our study illustrates that the complexity of the relationships among the predictors of QoL in chronic patients of schizophrenia should be considered when designing studies on QoL of this group.

GM-CSF production by epithelial cell line: upregulation by ultraviolet A.

It was demonstrated that UVB increases synthesis and expression of IL‐1α and GM‐CSF by keratinocytes. Upregulation of GM‐CSF by UVB is reported to be mediated by IL‐1α. However, regulation of IL‐1α and GM‐CSF by UVA is not well‐known. The purpose of the present study was to evaluate the effects of UVA on IL‐1α and GM‐CSF production. Here we used a competitive RT‐PCR for measuring cytokine gene expression in an epidermal cell line after UVA irradiation. IL‐1α and GM‐CSF mRNA did not show any change at 1 h and 6 h following exposure to UVA. After UVA irradiation, however, IL‐1α mRNA decreased and GM‐CSF mRNA increased at 24 h and the level of GM‐CSF in culture supernatant increased at 24 h and 48 h. Addition of antihuman IL‐1α neutralizing antibody to UVA irradiated cells did not prevent the increase of GM‐CSF mRNA expression. These results suggest that UVA radiation may induce GM‐CSF production through an IL‐1α independent pathway.

Brain Factor-7 Extracted from Bombyx mori Enhances Cognition and Attention in Normal Children

It has been reported that brain factor-7 (BF-7) extracted from Bombyx mori improves cognitive functions in normal juveniles and adults as well as cognitively impaired patients. Clinical studies with normal children evaluated the role of BF-7 on brain function in these patients. The objective of this study was to improve cognitive functions of normal schoolchildren with BF-7. Forty-six normal healthy children were divided into two treatment groups: BF-7 (9.9 +/- 1.18 years old; 9 boys, 14 girls) and placebo (9.8 +/- 1.03 years old; 10 boys, 13 girls). The Color Trails Making Test was used to measure the efficacy of BF-7 on cognition and attention. Results showed that BF-7 reduced the response time by an average of 23% for the Color Trails Making Test. Moreover, BF-7 improved the accuracy of the task around twofold. The results reveal that BF-7 improves brain function for attention and cognitive flexibility in children.