OBJECTIVES: Considering large diversity of clinical presentation of schizophrenia, it is important to identify valid clinical subtypes or dimensions that might have homogeneous biological underpinning. The current study aimed to explore lifetime symptom-based dimensional phenotypes in patients with chronic schizophrenia, and to investigate their correlation with cognitive functions and other clinical characteristics. METHODS: Lifetime-based symptoms and additional clinical variables were measured using the Diagnostic Interview for Genetic Studies and the Schedule for the Deficit Syndrome in 315 clinically stable patients with chronic schizophrenia. Through principal components factor analysis, eight dimensional phenotypes were obtained. Comprehensive neuropsychological tests were administered for 103 out of 315 patients, and domain scores were calculated for cognitive domains defined in the MATRICS consensus battery. RESULTS: 'Non-paranoid delusion factor' including delusions of grandiose or religious nature, showed significant negative correlation with processing speed, working memory, attention/vigilance, and general cognitive ability, and positive correlation with intra-individual variability. 'Negative symptom factor' showed significant negative correlation only with general cognitive ability. Those two factors were also negatively correlated with function levels measured by Global Assessment Scale (GAS), and associated with poor treatment responses. CONCLUSION: Symptom-based dimensional phenotypes of schizophrenia measured on a lifetime basis showed discriminative correlation with cognitive function domains, global functioning level, and overall treatment responses, indicating their possibility as valid phenotype axes of schizophrenia having homogeneous biologic basis.
Appointments and Schedules ; Cognition ; Consensus ; Delusions ; Humans ; Memory, Short-Term ; Neuropsychological Tests ; Phenotype ; Schizophrenia*

When conducting large-scale cohort studies, numerous statistical issues arise from the range of study design, data collection, data analysis and interpretation. In genomic cohort studies, these statistical problems become more complicated, which need to be carefully dealt with. Rapid technical advances in genomic studies produce enormous amount of data to be analyzed and traditional statistical methods are no longer sufficient to handle these data. In this paper, we reviewed several important statistical issues that occur frequently in large-scale genomic cohort studies, including measurement error and its relevant correction methods, cost-efficient design strategy for main cohort and validation studies, inflated Type I error, gene-gene and gene-environment interaction and time-varying hazard ratios. It is very important to employ appropriate statistical methods in order to make the best use of valuable cohort data and produce valid and reliable study results.
Research Design ; Reproducibility of Results ; Proportional Hazards Models ; Humans ; *Human Genome Project ; *Data Interpretation, Statistical ; Cost-Benefit Analysis ; *Cohort Studies

Gastric cancer has been the most commonly diagnosed cancer in Korea although the age-standardized mortality and incidence has decreased gradually during last two decades. Helicobacter pylori infection and cigarette smoking are well-established risk factors, and the role of dietary factors, such as salted foods, fresh vegetables and fruits, soy foods, and processed or grilled meats on gastric carcinogenesis has been suggested. In this review, we review national and international gastric cancer statistics, studies on environmental risk factors conducted in the Korean population, and gastric cancer screening activities.
Fruit ; Helicobacter pylori ; Incidence ; Korea ; Mass Screening ; Meat ; Risk Factors ; Smoking ; Soy Foods ; Stomach Neoplasms ; Vegetables

Objectives: This study was aimed to assess the usefulness of the quantitative assessment of clock drawing test (CDT) combined with the Mini-Mental State Examination (MMSE) compared to that of the Montreal Cognitive Assessment (MoCA) or the MMSE alone for screening of dementia in Parkinson disease (PD) in patients with a low educational level. Methods: A representative sample of 91 PD patients was administered MMSE, MoCA and CDT. The discriminative validity of the MMSE, MoCA, and a MMSE+CDT combination for dementia screening was determined by estimating the sensitivity and specificity of each test and by testing integrated discrimination improvement (IDI). Results: The mean age and educational years were 69.0 (years) and 7.3 in the study population. The best screening cut-off points for the MMSE, MoCA, and MMSE+CDT were 25/26, 21/22 and 41/42. In a group of patients with educational years ≤6,
Dementia

Glass ionomer cement (GIC) is a tailor-made material that is used as a filling material in dentistry. GIC is cured by an acid-base reaction consisting of a glass filler and ionic polymers. When the glass filler and ionic polymers are mixed, ionic bonds of the material itself are formed. In addition, the extra polymer anion reacts with calcium in enamel or dentin to increase adhesion to the tooth tissue. GICs are widely used as adhesives for artificial crowns or orthodontic brackets, and are also used as tooth repair material, cavity liner, and filling materials. In this review, the current status of GIC research and development and its prospects for the future have been discussed in detail.

This study investigated the effects of peripheral neuropathy symptoms, self-care ability,and disturbances to daily life on quality of life (QoL) among gynecological cancer patients undergoing chemotherapy.Methods: The participants included 144 patients with gynecological cancer undergoing anticancerchemotherapy at a tertiary hospital in Seoul, South Korea, from December 1, 2021 to January 28,2022. Convenience sampling was used to recruit patients who had received 4 or more cycles of chemotherapy using a paclitaxel-platinum regimen, and a self-reported questionnaire was used to collect data. Descriptive statistics, the t-test, analysis of variance, Scheffé test, Pearson correlation coefficients, and multiple regression analysis were performed.Results: Most of the participants had ovarian cancer (70.1%) or endometrial cancer (14.6%), andthe most common number of treatment cycles was 6 to 10 (29.2%). The mean QoL (60.83±19.89)was greater than the midpoint. The regression model analyzing the patients’ QoL was statisticallysignificant (F=15.38, p<.001) with an explanatory power of 56.7%. Self-care ability (β=.39, p<.001),disturbances to daily life (β=–.38, p<.001), the duration of peripheral neuropathy symptoms(β=2.14, p=.034), and regular exercise (β=–2.12, p=.036) were found to significantly affect QoL.Conclusion: Efforts to improve the self-care ability of gynecological cancer patients who have experienced peripheral neuropathy after receiving chemotherapy and mitigate disturbances to their dailylife can improve their QoL. Healthcare professionals should identify peripheral neuropathy symptoms and examine the effects of the symptoms on patients’ daily lives. Improving the self-care abilityof patients and alleviating their limitations in daily life may improve QoL.

Background: As the prevalence of hypertension is increasing in Korea, the government is seeking policy actions to manage patients with hypertension more efficiently. In this paper, we aimed to identify factors associated with the use of medical care at hospitals among outpatients with hypertension. Methods: We analyzed a total of 15,040 cases of 3,877 outpatients with hypertension obtained from the Korea Medical Panel database from 2010 to 2016. The dependent variable was whether a patient with hypertension visited a hospital or not; and independent variables were the patient’s various socio-demographic, health-related, and heath-status characteristics. We conducted a generalized linear mixed model analysis with logit link for all the cases and then conducted it stratified by gender. Results: As a result of a multivariable analysis, women were less likely than to visit at a hospital (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.32–0.61) and people aged 65 years and older than those aged less than 65 years (OR, 0.71; 95% CI, 0.57– 0.89). Residents in Busan, Ulsan, and Gyeongnam were more likely than those in than Seoul, Gyeonggi, Incheon, and Jeju to visit a hospital (OR, 1.40; 95% CI, 1.05–1.86). The likelihood of visiting a hospital was high in people belonging to a group of: the highest level of annual household income (OR, 1.73; 95% CI, 1.30–2.29); Medical care aid recipients (OR, 1.94; 95% CI, 1.34–2.83); people having three or more complex chronic diseases (OR, 1.59; 95% CI, 1.19–2.11); people having diabetes (OR, 1.81; 95% CI, 1.41–2.32);or people having ischemic heart disease or cerebrovascular disease (OR, 6.80; 95% CI, 5.28–8.76). Also, we found that factors associated with the use of medical care at hospitals among outpatients with hypertension differed between genders. Conclusion A variety of factors seem to be associated with the use of medical care at hospitals among outpatients with hypertension.Future research needs to find a way to help patients with hypertension visit an appropriate medical institution between clinics and hospitals.

Background: There have been many studies on the associations between body mass index (BMI) and cognitive function. However, no study has ever compared the associations across the methods of categorizing BMI. In this study, we aimed to fill the gap in the previous studies and examine whether the obesity paradox is valid in the risk of cognitive function. Methods: Of the 10,254 people aged 45 and older from the Korean Longitudinal Study of Ageing from 2006 to 2016, 8,970 people were finalized as the study population. The dependent variable was whether a person has a normal cognitive function or not, and the independent variables of interest were BMI categorized by the World Health Organization Western Pacific Regional Office (WHO-WPRO) method, the WHO method, and a 10-group method. Covariates included sociodemographic factors, health behavior factors, and health status factors. A generalized linear mixed model analysis with a logit link was used. Results: In the adjusted model with all covariates, first, in the case of BMI categories of the WHO-WPRO method, underweight (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.15–1.17), overweight (OR, 1.36; 95% CI, 1.35–1.36), and obese (OR, 1.34; 95% CI, 1.33–1.34) groups were more likely to have a normal cognitive function than a normal-weight group. Next, in the case of BMI categories of the WHO method, compared to a normal-weight group, underweight (OR, 1.15; 95% CI, 1.14–1.16) and overweight (OR, 1.06; 95% CI, 1.06–1.07) groups were more likely to have a normal cognitive function; however, obese (OR, 0.62; 95% CI, 0.61–0.63) group was less likely to have it. Lastly, in the case of the 10-group method, as BMI increased, the likelihood to have a normal cognitive function changed like a wave, reaching a global top at group-7 (26.5 kg/㎡ ≤ BMI <28.0 kg/㎡ ). Conclusion The associations between BMI and cognitive function differed according to how BMI was categorized among people aged 45 and older in Korea, which suggests that cognitive function may be positively associated with BMI in some categories of BMI but negatively in its other categories. Health policies to reduce cognitive impairment need to consider this association between BMI and cognitive function.

In recent years, genome-wide association (GWA) studies have successfully led to many discoveries of genetic variants affecting common complex traits, including height, blood pressure, and diabetes. Although GWA studies have made much progress in finding single nucleotide polymorphisms (SNPs) associated with many complex traits, such SNPs have been shown to explain only a very small proportion of the underlying genetic variance of complex traits. This is partly due to that fact that most current GWA studies have relied on single-marker approaches that identify single genetic factors individually and have limitations in considering the joint effects of multiple genetic factors on complex traits. Joint identification of multiple genetic factors would be more powerful and provide a better prediction of complex traits, since it utilizes combined information across variants. Recently, a new statistical method for joint identification of genetic variants for common complex traits via the elastic-net regularization method was proposed. In this study, we applied this joint identification approach to a large-scale GWA dataset (i.e., 8842 samples and 327,872 SNPs) in order to identify genetic variants of obesity for the Korean population. In addition, in order to test for the biological significance of the jointly identified SNPs, gene ontology and pathway enrichment analyses were further conducted.
Blood Pressure ; Genome-Wide Association Study ; Joints ; Obesity ; Polymorphism, Single Nucleotide

Biomarkers are characteristic biological properties that can be detected and measured in a variety of biological matrices in the human body, including the blood and tissue, to give an indication of whether there is a threat of disease, if a disease already exists, or how such a disease may develop in an individual case. Along the continuum from exposure to clinical disease and progression, exposure, internal dose, biologically effective dose, early biological effect, altered structure and/or function, clinical disease, and disease progression can potentially be observed and quantified using biomarkers. While the traditional discovery of biomarkers has been a slow process, the advent of molecular and genomic medicine has resulted in explosive growth in the discovery of new biomarkers. In this review, issues in evaluating biomarkers will be discussed and the biomarkers of environmental exposure, early biologic effect, and susceptibility identified and validated in epidemiological studies will be summarized. The spectrum of genomic approaches currently used to identify and apply biomarkers and strategies to validate genomic biomarkers will also be discussed.
Disease Progression ; Environmental Exposure ; *Epidemiologic Studies ; *Genetic Markers ; Humans ; Molecular Epidemiology/*methods ; Neoplasms/epidemiology ; Republic of Korea/epidemiology