To develop novel antibiotic peptides useful as therapeutic drugs, the enantiomeric analogue of pleurocidin (Ple), which is a well known 25-mer antimicrobial peptide, was designed for proteolytic resistance by D-amino acids substitution. The proteolytic resistance was confirmed by using HPLC after the digestion with various proteases. To investigate the antibiotic effect of L- and D-Ple, the antibacterial activity and hemolytic effect were tested against human erythrocytes. The D-Ple showed a decreased antibacterial activity and a dramatically decreased hemolytic activity compared with L-Ple. The hemolytic effect of analogue was further confirmed by using calcein leakage measurement with liposome. To elucidate these results, the secondary structure of the peptides was investigated by using circular dichroism spectroscopy. The results revealed that D-Ple, as well as L-Ple, had typical ?-helical structures which were mirror images, with a different helicity. These results suggested that the discrepancy of the structure between the two peptides made their antibacterial activity distinct.
Anti-Infective Agents/*chemistry/*pharmacology ; Erythrocytes/drug effects ; Fish Proteins/*chemistry/*pharmacology ; Gram-Negative Bacteria/drug effects ; Gram-Positive Bacteria/drug effects ; Hemolytic Agents/chemistry/pharmacology ; Humans ; Microbial Sensitivity Tests ; Stereoisomerism ; Structure-Activity Relationship

BACKGROUND AND PURPOSE: One explanation for the ‘obesity paradox’, where obese patients seem to have better cardiovascular outcomes than lean patients, is that obese patients display an identifiable high cardiovascular risk phenotype that may lead to receiving or seeking earlier/more aggressive treatment. METHODS: We analyzed a clinical trial dataset comprising 3643 recent (<120 days) ischemic stroke patients followed up for 2 years. Subjects were categorized as lean (body mass index [BMI], <25 kg/m², n=1,006), overweight (25-29.9 kg/m², n=1,493), or obese (≥30 kg/m², n=1,144). Subjects were classified as level 0 to III depending on the number of secondary prevention prescriptions divided by the number of potentially indicated drugs (0=none of the indicated medications and III=all indicated medications as optimal combination drug treatment [OCT]). Independent associations between each BMI category and stroke/myocardial infarction/vascular death (major vascular events [MVEs]) and all-cause death were assessed. RESULTS: MVEs occurred in 17.4% of lean, 16.1% of overweight, and 17.1% of obese patients; death occurred in 7.3%, 5.5%, and 5.1%, respectively. Individuals with a higher BMI status received more OCT (45.8%, 51.7%, and 55.3%, respectively; P<0.001). In the lean patient group, multivariable adjusted Cox analyses, showed that compared with levels 0-I, level II and level III were linked to lower risk of MVEs (hazard ratio [HR] 0.55; 95% confidence interval [CI]: 0.32–0.95 and HR 0.48; 95% CI: 0.28−0.83, respectively) and death (0.44; 0.21–0.96 and 0.23; 0.10−0.54, respectively). CONCLUSIONS: OCT for secondary prevention after an ischemic stroke is less frequent in lean (vs. obese) subjects, but when implemented is related to significantly better clinical outcomes.
Body Mass Index ; Dataset ; Humans ; Obesity* ; Overweight ; Phenotype ; Prescriptions ; Secondary Prevention ; Stroke* ; Vitamins*

OBJECTIVE: The purpose of this study was to evaluate the levels of DNA damage in human lymphocytes caused by smoking and other lifestyle factors. METHODS: The study population consisted of 173 normal healthy male adults from 21 to 59 years old. The demographic and lifestyle variables were obtained from administered questionnaires. The level of lymphocytic DNA damage in the peripheral blood was evaluated by the Comet assay. Statistical analyses were done by general linear model analysis and Dunnett's multiple comparison. RESULTS: The difference in DNA damage between smokers and non-smokers was statistically significant. The means for the Tail%DNA were found to be 10.48 in the current smokers and 9.60 in the non-smokers (p<0.05). The tail moment means were 1.58 and 1.45 (p<0.05) for the current smokers and non-smokers, respectively. The number of cigarettes smoked per day did not result in a significant difference in the level of DNA damage among the smokers. Other lifestyle factors such as age, and drinking and exercise habits were not related to DNA damage. CONCLUSIONS: The DNA damage in the lymphocytes of smokers was found to be significantly higher than that for non-smokers. However, the number of cigarettes smoked per day was not related to DNA damage. Further study is needed to evaluate the relationship between the amount of smoking and level of damage to DNA. In addition, the status of DNA repair activities should be assessed.
Smoking/*adverse effects ; Risk-Taking ; Middle Aged ; Male ; Lymphocytes/*pathology ; Linear Models ; Life Style ; Korea/epidemiology ; Humans ; DNA Damage/*physiology ; Comet Assay ; Case-Control Studies ; Adult

OBJECTIVES: An appropriate sampling strategy for estimating an epidemiologic volume of diabetes has been evaluated through a simulation. METHODS: We analyzed about 250 million medical insurance claims data submitted to the Health Insurance Review & Assessment Service with diabetes as principal or subsequent diagnoses, more than or equal to once per year, in 2003. The database was re-constructed to a 'patient-hospital profile' that had 3,676,164 cases, and then to a 'patient profile' that consisted of 2,412,082 observations. The patient profile data was then used to test the validity of a proposed sampling frame and methods of sampling to develop diabetic-related epidemiologic indices. RESULTS: Simulation study showed that a use of a stratified two-stage cluster sampling design with a total sample size of 4,000 will provide an estimate of 57.04% (95% prediction range, 49.83 - 64.24%) for a treatment prescription rate of diabetes. The proposed sampling design consists, at first, stratifying the area of the nation into "metropolitan/city/county" and the types of hospital into "tertiary/secondary/primary/clinic" with a proportion of 5:10:10:75. Hospitals were then randomly selected within the strata as a primary sampling unit, followed by a random selection of patients within the hospitals as a secondly sampling unit. The difference between the estimate and the parameter value was projected to be less than 0.3%. CONCLUSIONS: The sampling scheme proposed will be applied to a subsequent nationwide field survey not only for estimating the epidemiologic volume of diabetes but also for assessing the present status of nationwide diabetes control.
Bias (Epidemiology) ; Cluster Analysis ; Diabetes Mellitus/*epidemiology/prevention & control ; Epidemiologic Methods ; Humans ; Insurance Claim Review ; Korea ; Medical Records ; Sampling Studies

BACKGROUND: It is well known that patients with neurological disorders are vulnerable to depression. However, in Korea, National Health Insurance services had banned non-psychiatrists from prescribing antidepressants for more than 2 months until January 2017. Now, neurologists are able to prescribe antidepressants to patients with only four neurological disorders. Due to this recent change in national health insurance policy, there will be a large change in the prescription pattern of antidepressants. In this study, we performed an analysis of antidepressant prescription patterns in Korea prior to this recent policy change. METHODS: The source population of this retrospective cohort study is the Health Insurance Review & Assessment Service database. We analyzed the claim database for patients who have one of four major neurologic disorders and had healthcare documentation submitted by healthcare providers between January 1, 2011 and December 31, 2016. RESULTS: During 2012–2016, antidepressant prescription rates of 6.21% (127,192 of a total 2,048,165 patients), 9.93% (81,861 out of 824,290), 10.12% (173,582 of 1,714,776), and 13.36% (48,530 of 363,347) were found for cerebrovascular disease, epilepsy, dementia, and Parkinson's disease respectively. The most frequently prescribed antidepressant in cerebrovascular disease and epilepsy was tricyclic antidepressants (TCAs). In Parkinson's disease and dementia, the most frequently used antidepressant was selective serotonin reuptake inhibitors. CONCLUSIONS: The overall prescription rate of antidepressants was much lower than the estimated rates reported in other countries. TCAs were the primarily prescribed antidepressant. It is now expected that TCAs will be replaced by newer antidepressants.
Antidepressive Agents ; Antidepressive Agents, Tricyclic ; Cerebrovascular Disorders ; Cohort Studies ; Delivery of Health Care ; Dementia ; Depression ; Epilepsy ; Health Personnel ; Humans ; Insurance, Health ; Korea ; National Health Programs ; Nervous System Diseases ; Parkinson Disease ; Prescriptions ; Retrospective Studies ; Serotonin Uptake Inhibitors

Background: Previous studies on the epidemiology and complications of congenital adrenal hyperplasia (CAH) were conducted in Western countries and in children/adolescents. We aimed to explore the epidemiology of CAH, as well as the risk of comorbidities and mortality, in a Korean nationwide case-control study. Methods: CAH patients (n=2,840) were included between 2002 and 2017 from the National Health Insurance Service database and the Rare Intractable Disease program. CAH patients were compared, at a 1:10 ratio, with age-, sex-, and index year-matched controls (n=28,400). Results: The point prevalence of CAH patients in Korea was 1 in 18,745 persons in 2017. The annual incidence rate declined between 2003 and 2017 from 3.25 to 0.41 per 100,000 persons. CAH patients were at elevated risk for cardiovascular disease (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.4 to 1.9), stroke (OR, 1.7; 95% CI, 1.3 to 2.0), diabetes mellitus (OR, 2.8; 95% CI, 2.6 to 3.1), dyslipidemia (OR, 2.4; 95% CI, 2.2 to 2.6), and psychiatric disorders (OR, 1.5; 95% CI, 1.3 to 1.6). Fracture risk increased in CAH patients aged over 40 years (OR, 1.4; 95% CI, 1.1 to 1.7). CAH patients were at higher risk of mortality than controls (hazard ratio, 1.6; 95% CI, 1.3 to 2.0). Conclusion Our nationwide study showed a recent decline in the incidence of CAH and an elevated risk for cardiovascular, metabolic, skeletal, and psychiatric disorders in CAH patients. Lifelong management for comorbidity risk is a crucial component of treating CAH patients.

BACKGROUND: Avoparcin has been banned in Korea since 8 years ago, but vancomycin-resistant enterococci (VRE) has not been proven to be eradicated from the domestic livestock. This study was purposed to investigate the prevalence of VRE and perform an epidemiologic survey in chicken farms located in Seoul and Kyunggi Province. METHODS: Feces were collected freshly from chickens and workers and their families in three free-range chicken farms and three cage-raising chicken farms. All swabs were inoculated on enterococcosel agar containing 6 microgram/mL of vancomycin. Minimum inhibitory concentrations of teicoplanin and vancomycin were determined using the agar dilution method. Vancomycin resistance were genotyped with multiplex PCR using primers specific for vanA, vanB, and vanC1. Epidemiolgic survey was carried out using a uniform questionnaire to obtain information about the number and variety of livestock, feeding protocols, physical farming conditions, maintenance protocols, hygiene, and employment conditions. RESULTS: vanA Enterococcus facium was isolated from 37 (2.9%) of 1280 chickens. There were no VRE carriers found among the workers and their families. The prevalence of VRE among cage-raising chickens was 4.8% compared to 0.6% for free-range chickens. The difference between the two groups was highly significant (P<0.001). CONCLUSION: There still was a significant rate of VRE colonization in chicken livestock in Seoul and Kyunggi Province. Physical farming conditions of cage-raising chicken farms seemed to be associated with a high VRE colonization rate.
Agar ; Chickens* ; Colon ; Employment ; Enterococcus ; Feces ; Gyeonggi-do* ; Humans ; Hygiene ; Korea ; Livestock ; Microbial Sensitivity Tests ; Multiplex Polymerase Chain Reaction ; Prevalence* ; Seoul* ; Teicoplanin ; Vancomycin ; Vancomycin Resistance ; Surveys and Questionnaires

BACKGROUND: Avoparcin has been banned in Korea since 8 years ago, but vancomycin-resistant enterococci (VRE) has not been proven to be eradicated from the domestic livestock. This study was purposed to investigate the prevalence of VRE and perform an epidemiologic survey in chicken farms located in Seoul and Kyunggi Province. METHODS: Feces were collected freshly from chickens and workers and their families in three free-range chicken farms and three cage-raising chicken farms. All swabs were inoculated on enterococcosel agar containing 6 microgram/mL of vancomycin. Minimum inhibitory concentrations of teicoplanin and vancomycin were determined using the agar dilution method. Vancomycin resistance were genotyped with multiplex PCR using primers specific for vanA, vanB, and vanC1. Epidemiolgic survey was carried out using a uniform questionnaire to obtain information about the number and variety of livestock, feeding protocols, physical farming conditions, maintenance protocols, hygiene, and employment conditions. RESULTS: vanA Enterococcus facium was isolated from 37 (2.9%) of 1280 chickens. There were no VRE carriers found among the workers and their families. The prevalence of VRE among cage-raising chickens was 4.8% compared to 0.6% for free-range chickens. The difference between the two groups was highly significant (P<0.001). CONCLUSION: There still was a significant rate of VRE colonization in chicken livestock in Seoul and Kyunggi Province. Physical farming conditions of cage-raising chicken farms seemed to be associated with a high VRE colonization rate.
Agar ; Chickens* ; Colon ; Employment ; Enterococcus ; Feces ; Gyeonggi-do* ; Humans ; Hygiene ; Korea ; Livestock ; Microbial Sensitivity Tests ; Multiplex Polymerase Chain Reaction ; Prevalence* ; Seoul* ; Teicoplanin ; Vancomycin ; Vancomycin Resistance ; Surveys and Questionnaires

Meta-analysis of diagnostic test accuracy studies differs from the usual meta-analysis of therapeutic/interventional studies in that, it is required to simultaneously analyze a pair of two outcome measures such as sensitivity and specificity, instead of a single outcome. Since sensitivity and specificity are generally inversely correlated and could be affected by a threshold effect, more sophisticated statistical methods are required for the meta-analysis of diagnostic test accuracy. Hierarchical models including the bivariate model and the hierarchical summary receiver operating characteristic model are increasingly being accepted as standard methods for meta-analysis of diagnostic test accuracy studies. We provide a conceptual review of statistical methods currently used and recommended for meta-analysis of diagnostic test accuracy studies. This article could serve as a methodological reference for those who perform systematic review and meta-analysis of diagnostic test accuracy studies.
Area Under Curve ; Databases, Factual ; Diagnostic Tests, Routine/*statistics & numerical data ; Humans ; ROC Curve ; *Research ; Software

OBJECTIVE: We intended to evaluate the double standard status and to identify factors of determining double standard criteria in multinational corporations of Korea, and specifically those in the occupational health and safety area. METHODS: A postal questionnaire had been sent, between August 2002 and September 2002, to multinational corporations in Korea. A double standard company was defined as those who answered in more than one item as adopting a different standard among the five items regarding double standard identification. By comparing double standard companies with equivalent standard companies, determinants for double standards were then identified using logistic regression analysis. RESULTS: Of multinational corporations, 45.1% had adopted a double standard. Based on the question naire's scale level, the factor of 'characteristic and size of multinational corporation' was found to have the most potent impact on increasing double standard risk. On the variable level, factors of 'number of affiliated companies' and 'existence of an auditing system with the parent company' showed a strong negative impact on double standard risk. CONCLUSION: : Our study suggests that a distinctive approach is needed to manage the occupational safety and health for multinational corporations. This approach should be focused on the specific level of a corporation, not on a country level.
Humans ; Internationality ; Korea* ; Logistic Models ; Occupational Health ; Parents