COVID-19 Outcome and Tobacco Product Use: Case-Control and Retrospective Cohort Studies Using Nationwide Samples.

BACKGROUND: Conflicting evidence exists regarding the association between smoking and the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We investigated the association between combustible cigarette (CC) smoking, noncombustible tobacco product (NCTP) use, and the use of any tobacco product with various coronavirus disease 2019 (COVID-19) outcomes. METHODS: A case-control study was conducted using the Korea Disease Control and Prevention Agency-COVID19-National Health Insurance Service (NHIS) cohort. A retrospective cohort study was conducted using 12,571,698 individuals from the NHIS cohort. Logistic regression evaluated the association between CC smoking, NCTP use, and use of any tobacco product with SARS-CoV-2 infection. Poisson regression evaluated the association between these forms of tobacco product use and COVID-19-related hospitalization and mortality. RESULTS: In the case-control study, we identified 30,878 cases of SARS-CoV-2 infection. The odds ratios (95% confidence intervals [CIs]) for SARS-CoV-2 infection were lower among current CC smokers (0.51, 0.48-0.54), current- and former-NCTP users (0.80, 0.74-0.88; 0.82, 0.74-0.91), and current users of any tobacco product (0.52, 0.49-0.55) relative to never user controls. In retrospective cohort study, we identified 16,521 COVID-19-related hospitalization and 362 COVID-19-related deaths. The relative risks (95% CIs) for COVID-19-related hospitalization were lower among current CC smokers (0.51, 0.48-0.54) and current users of any tobacco product (0.53, 0.50-0.56) relative to never user controls. There was no association between the use of tobacco product and COVID-19-related mortality. CONCLUSION: Current CC smokers and current users of any tobacco product showed reduced risk of SARS-CoV-2 infection and COVID-19-related hospitalization. It remains uncertain whether these relationships are causal.

Use of heated tobacco products where their use is prohibited.

INTRODUCTION: Stealth use implies using tobacco products where their use is prohibited. This paper aimed to investigate stealth use of heated tobacco products (HTPs) in terms of its prevalence and associated factors. METHODS: An online survey was conducted to investigate the use of HTPs in 7000 randomly selected participants (2300 men and 4700 women, aged 20-69 years) from the database registered with an online-research company; we used a sex ratio of 1:2, considering a low female prevalence of tobacco use in Korea. Of total participants, 574 (8.2%) were current HTP users. Among them, we identified the participants who had practised HTPs stealth use, and evaluated associated factors using multivariable Poisson regression. RESULTS: A total of 574 participants were identified as current HTP users, and 455 (79.2%) reported stealth use of HTPs during the month before the survey. Stealth use was more frequent in dual cigarette users (HTPs and electronic cigarettes (ECs); adjusted prevalence ratio (aPR) 1.33, 95% CI 1.16 to 1.52) and triple users (HTPs, ECs and combustible cigarettes; aPR 1.18, 95% CI 1.04 to 1.33), as compared with single-HTP users. Stealth use was more prevalent among participants who agreed with allowing indoor HTP use (aPR 1.18, 95% CI 1.11 to 1.26). CONCLUSION: Stealth use was prevalent among current HTP users, especially among the poly-users of tobacco products. Considering the positive relationship between an agreement with allowing indoor use of HTPs and stealth use, a campaign to promote change in attitudes of HTP users about their indoor use may be warranted to protect non-users.

Design of a multivalent bifunctional chelator for diagnostic 64Cu PET imaging in Alzheimer's disease.

Herein, we report a 64Cu positron emission tomography (PET) imaging agent that shows appreciable in vivo brain uptake and exhibits high specific affinity for beta-amyloid (Aß) aggregates, leading to the successful PET imaging of amyloid plaques in the brains of 5xFAD mice versus those of wild-type mice. The employed approach uses a bifunctional chelator with two Aß-interacting fragments that dramatically improves the Aß-binding affinity and lipophilicity for favorable blood-brain barrier penetration, while the use of optimized-length spacers between the Cu-chelating group and the Aß-interacting fragments further improves the in vivo Aß-binding specificity and brain uptake of the corresponding 64Cu PET imaging agent.

Azo-Stilbene and Pyridine-Amine Hybrid Multifunctional Molecules to Target Metal-Mediated Neurotoxicity and Amyloid-ß Aggregation in Alzheimer's Disease.

Neurodegenerative diseases such as Alzheimer's disease (AD) are associated with progressive neuronal cell death, and they are commonly correlated with aberrant protein misfolding and aggregation of Aß peptides. Transition metal ions (Cu, Fe, and Zn) have been shown to promote aggregation and oxidative stress through formation of Aß-metal complexes. In this context, integrating molecular scaffolds rationally is used here to generate multifunctional molecules as modulators for metal-induced abnormalities. This work encompasses two azo-stilbene (AS)-derived compounds (AS-HL1 and AS-HL2), the rationale behind the design, their synthesis, characterization, and metal chelation ability [Cu(II) and Zn(II)]. The molecular frameworks of the designed compounds consist of stilbene as an Aß-interacting moiety, whereas N,N,O and N,N,N,O donor atoms are linked to generate the metal chelation moiety. Furthermore, we went on exploring their multifunctionality with respect to (w.r.t.) (i) their metal chelating capacities and (ii) their utility to modulate the aggregation pathways of both metal-free and metal-bound amyloid-ß, (iii) scavenge free radicals, and (iv) inhibit the activity of acetylcholinesterase and (v) cytotoxicity. Moreover, the compounds were able to sequester Cu2+ from the Aß-Cu complex as studied by the UV-visible spectroscopic assay. Molecular docking studies were also performed with Aß and acetylcholinesterase enzyme. Overall, the studies presented here qualify these molecules as promising candidates for further investigation in the quest for finding a treatment for Alzheimer's disease.

Divalent 2-(4-Hydroxyphenyl)benzothiazole Bifunctional Chelators for 64Cu Positron Emission Tomography Imaging in Alzheimer's Disease.

Herein, we report a new series of divalent 2-(4-hydroxyphenyl)benzothiazole bifunctional chelators (BFCs) with high affinity for amyloid ß aggregates and favorable lipophilicity for blood-brain barrier penetration. The addition of an alkyl carboxylate ester pendant arm offers high binding affinity toward Cu(II). The novel BFCs form stable 64Cu-radiolabeled complexes and exhibit promising partition coefficient (logD) values of 1.05-1.85. Among the five compounds tested, the 64Cu-YW-15 complex exhibits significant staining of amyloid ß plaques in ex vivo autoradiography studies. In addition, biodistribution studies show that 64Cu-YW-15-Me exhibits moderate brain uptake (0.69 ± 0.08 %ID/g) in wild type mice.

The smoking population is not hardening in South Korea: a study using the Korea Community Health Survey from 2010 to 2018.

INTRODUCTION: The hardening hypothesis proposes that the proportion of hardcore smokers increases when smoking prevalence declines. To evaluate whether such hardening occurs in South Korea, we examined the association between quitting behaviours, the number of cigarettes smoked per day and the proportion of hardcore smokers and smoking prevalence among local districts in South Korea. METHODS: This study used the cross-sectional data from the Korea Community Health Survey (2010-2018) to examine local district-level associations between smoking prevalence and quit attempts, quit plans, quit ratios, cigarettes smoked per day and the proportion of hardcore smokers. Panel regression analysis was performed using the indicators of hardcore smoking (quit attempts, quit plans, quit ratios, cigarettes smoked per day and proportion of hardcore smokers) as the outcome variables, and prevalence of smoking, local districts, age and sex as predictor variables. RESULTS: When the smoking prevalence of the districts decreased by 1%, quit attempts, quit plans and quit ratios increased by 0.24% (95% CI 0.11 to 0.37), 0.37% (95% CI 0.26 to 0.47) and 1.71% (95% CI 1.65 to 1.76), respectively. Cigarette consumption decreased by 0.17 cigarettes per day (95% 0.15 to 0.19), and the prevalence of hardcore smokers decreased by 0.88% (95% CI 0.78 to 0.98) when smoking prevalence decreased by 1%. CONCLUSION: Hardening of smoking did not occur in South Korea when smoking prevalence declined, which suggests tobacco control policies in South Korea have been effective in reducing smoking prevalence without increasing the proportion of hardcore smokers.

Prevalence and risk factors of maternal depression among women who participated in a home visitation program in South Korea.

PURPOSE: The psychosocial health of mother is crucial for healthy prenatal period and early childhood. We investigated the prevalence and risk factors of maternal depression during pregnancy and postpartum among women who participated in a home visitation program in Seoul, South Korea (Seoul Healthy First Step Project, SHFSP). METHODS: We analyzed 80,116 women who participated in the SHFSP, which was launched by Seoul metropolitan government in 2013, and defined peripartum depression as a score ≥ 10 on the Korean version of the Edinburgh Postnatal Depression Scale (EPDS). Sociodemographic factors and psychosocial health status were evaluated through a standardized questionnaire completed by participants upon program registration. We calculated the prevalence of women at risk for peripartum depression and evaluated associated factors by multivariable logistic regression analysis. RESULTS: Prevalence of women at risk for peripartum depression was 17.7% (prepartum depression: 14.2%, postpartum depression: 24.3%). Younger maternal age, low income (OR 2.40, 95% CI 2.03-2.84), disability (2.61, 1.96-3.47), single parenthood (3.27, 2.69-3.99), and smoking (2.02, 1.44-2.83) increased the peripartum depression risk. Furthermore, experience of stress, change, or loss over the past 12 months (3.36, 3.22-3.50), history of treatment for emotional issues (2.47, 2.27-2.70), experience of child abuse (1.91, 1.74-2.11), and domestic violence (2.25, 1.81-2.80) increased the risk for peripartum depression, whereas having helpers for the baby (0.62, 0.58-0.67), having someone to talk with (0.31, 0.27-0.35), and considering oneself confident (0.30, 0.29-0.31) decreased the risk. CONCLUSIONS: Policies to reduce and manage peripartum depression should be strengthened, with a focus on high-risk pregnant and puerperal women.

Amphiphilic Distyrylbenzene Derivatives as Potential Therapeutic and Imaging Agents for Soluble and Insoluble Amyloid ß Aggregates in Alzheimer's Disease.

Alzheimer's Disease (AD) is the most common neurodegenerative disease, and efficient therapeutic and early diagnostic agents for AD are still lacking. Herein, we report the development of a novel amphiphilic compound, LS-4, generated by linking a hydrophobic amyloid-binding distyrylbenzene fragment with a hydrophilic triazamacrocycle, which dramatically increases the binding affinity toward various amyloid ß (Aß) peptide aggregates, especially for soluble Aß oligomers. Moreover, upon the administration of LS-4 to 5xFAD mice, fluorescence imaging of LS-4-treated brain sections reveals that LS-4 can penetrate the blood-brain barrier and bind to the Aß oligomers in vivo. In addition, the treatment of 5xFAD mice with LS-4 reduces the amount of both amyloid plaques and associated phosphorylated tau aggregates vs the vehicle-treated 5xFAD mice, while microglia activation is also reduced. Molecular dynamics simulations corroborate the observation that introducing a hydrophilic moiety into the molecular structure of LS-4 can enhance the electrostatic interactions with the polar residues of the Aß species. Finally, exploiting the Cu2+-chelating property of the triazamacrocycle, we performed a series of imaging and biodistribution studies that show the 64Cu-LS-4 complex binds to the amyloid plaques and can accumulate to a significantly larger extent in the 5xFAD mouse brains vs the wild-type controls. Overall, these results illustrate that the novel strategy, to employ an amphiphilic molecule containing a hydrophilic moiety attached to a hydrophobic amyloid-binding fragment, can increase the binding affinity for both soluble and insoluble Aß aggregates and can thus be used to detect and regulate various Aß species in AD.

Amyloid ß-Binding Bifunctional Chelators with Favorable Lipophilicity for 64Cu Positron Emission Tomography Imaging in Alzheimer's Disease.

Herein, we report a new series of bifunctional chelators (BFCs) with a high affinity for amyloid aggregates, a strong binding affinity toward Cu(II), and favorable lipophilicity for potential blood-brain barrier penetration. The alkyl carboxylate ester pendant arms offer up to 3 orders of magnitude higher binding affinity toward Cu(II) and enable the BFCs to form stable 64Cu-radiolabeled complexes. Among the five compounds tested, the 64Cu-YW-7 and 64Cu-YW-10 complexes exhibit strong and specific staining of amyloid plaques in ex vivo autoradiography studies. Importantly, these BFCs have promising partition coefficient (log Doct) values of 0.91-1.26 and show some brain uptake in biodistribution studies using CD-1 mice. Overall, these BFCs could serve as lead compounds for the development of positron emission tomography imaging agents for AD diagnosis.

Trends in the Socioeconomic Inequalities Related to Second-Hand Smoke Exposure as Verified by Urine Cotinine Levels Among Nonsmoking Adults: Korea National Health and Nutrition Examination Survey 2008-2018.

INTRODUCTION: The expansion of smoke-free policies has reduced the prevalence of second-hand smoke (SHS) exposure; however, declines differ according to socioeconomic positions. We evaluated the trends in socioeconomic inequalities related to SHS exposure in nonsmoking Korean adults from 2008 to 2018. METHODS: We analyzed 30,027 nonsmoking adults from the Korea National Health and Nutrition Examination Survey 2008 to 2018. We evaluated trends in urine cotinine levels, self-reported prevalence of SHS exposure at workplaces and homes, and people exhibiting nonmeasurable urine cotinine levels between 2008 and 2018. To evaluate the yearly decline differences of urine cotinine levels according to socioeconomic positions, we calculated the interaction effects of year and education, household incomes, and occupation from linear regression analysis. RESULTS: In the last 11 years, the geometric means of urine cotinine levels decreased from 3.53 (95% CI 2.96-4.19) ng/mL to 0.60 (0.57-0.64) ng/mL in males, and from 2.36 (2.03-2.73) ng/mL to 0.53 (0.51-0.56) ng/mL in females. The prevalence of SHS exposure at workplaces and homes also declined. In the multivariate model, the interaction effects between education and years were significant; therefore, indicating a substantial yearly decline of urine cotinine levels in higher educated individuals. The interaction effects between household incomes and years were only significant among males; the interaction effects between occupations and years were not significant. CONCLUSIONS: SHS exposure in nonsmoking Korean adults has consistently decreased; however, socioeconomic inequalities related to SHS exposure by education level have widened. Policies targeting socioeconomically disadvantaged populations should be implemented to decrease the disparities of SHS exposure. IMPLICATIONS: Along with tobacco control policies, the prevalence of self-reported and urinary cotinine verified SHS exposure has decreased in the last 11 years. In contrast, the socioeconomic inequalities related to SHS exposure by education level have increased over time. This study emphasizes the need for implementing tobacco control policies to reduce disparities of SHS exposure.

Prevalence and predictors of heated tobacco product use and its relationship with attempts to quit cigarette smoking among Korean adolescents.

INTRODUCTION: Heated tobacco products (HTPs) have been available in the Korean market since June 2017. In this study, we examined the prevalence and predictors of HTP use among Korean adolescents and the association between HTP and electronic cigarette (EC) use and attempts to quit conventional cigarette (CC) smoking. METHODS: We analysed the data of a representative sample (n=60 040) of 13-18-year-old middle-school and high-school students in Korea who had participated in the 14th Korea Youth Risk Behavior Web-based Survey in 2018. RESULTS: The prevalence of ever HTP use among Korean adolescents was 2.9% (men: 4.4%, women: 1.2%), a year after the introduction of HTPs in the Korean market. Furthermore, 81.3% of the 1568 ever HTP users were triple users of HTPs, ECs and CCs. Multivariate analysis revealed that ever HTP use was greater among men, higher-grade students, current CC and/or EC users and risky alcohol drinkers. Among current CC smokers, ever users of ECs (28%-30%) and ever HTP users and current EC users (48%) were more likely to have attempted to quit CC smoking than those who had never used HTPs and ECs. However, there were fewer HTP and/or EC ever users among ever CC smokers who successfully quit smoking. CONCLUSIONS: Many adolescents, especially CC and EC users, had already used HTPs shortly after the introduction of HTPs in Korea. The use of newer types of tobacco products is associated with lower odds of abstinence from CCs; therefore, it is important to protect adolescents from them.

Effect of usual source of care on receiving smoking cessation advice: Korean National Health Panel data analysis.

BACKGROUND: Despite various anti-smoking policies, the smoking rate in adults is still high in Korea. Doctors' advice is known to increase the smoking cessation success rate. However, few studies have reported the effect of having a usual source of care (USC) on receiving smoking cessation advice. OBJECTIVE: To determine the effect of USC on receiving smoking cessation advice. METHODS: We performed multiple panel logistic regression analyses to identify the effect of having a USC on the rate of receiving a doctor's smoking cessation advice using 2009, 2012 and 2013 datasets from the Korea Health Panel database. Only people who responded to questions regarding a USC and smoking cessation advice were analysed. Eventually, 5243 observations were included in the final analysis. RESULTS: A higher percentage of people with a USC received smoking cessation advice from doctors (58.4% in 2009, 64.0% in 2012 and 59.6% in 2013) than those not having a USC (28.6% in 2009, 37.5% in 2012 and 34.8% in 2013). The odds ratios (ORs) of receiving smoking cessation advice in people with a USC were higher than those of people without a USC after performing multiple panel logistic regression analysis with random effects (OR: 2.24; 95% confidence interval: 1.90-2.63). CONCLUSIONS: Having a USC increased the odds of receiving a doctor's smoking cessation advice in Koreans. The results of this study suggest that a health care policy that encourages having a USC is useful in receiving more smoking cessation advice in a Korean population.

Long-term trends in smoking prevalence and its socioeconomic inequalities in Korea, 1992-2016.

BACKGROUND: The aim of this study was to investigate long-term trends in smoking prevalence and its socioeconomic inequalities in Korea. METHODS: Data were collected from 10 rounds of the Social Survey of Statistics Korea between 1992 and 2016. A total of 524,866 men and women aged 19 or over were analyzed. Age-adjusted smoking prevalence was calculated according to three major socioeconomic position indicators: education, occupational class, and income. The prevalence difference, prevalence ratio, slope index of inequality (SII), and relative index of inequality (RII) were calculated to examine the magnitude of inequality in smoking. RESULTS: Smoking prevalence among men decreased from 71.7% in 1992 to 39.7% in 2016, while smoking prevalence among women decreased from 6.5% in 1992 to 3.3% in 2016. Socioeconomic inequalities in smoking prevalence according to the three socioeconomic position indicators were found in both men and women throughout the study period. In general, absolute and relative socioeconomic inequalities in smoking, measured by prevalence difference and prevalence ratio for education and occupational class, widened during the study period among Korean men and women. In men, the SII for income increased from 7.6% in 1999 to 10.8% in 2016 and the RII for income also increased from 1.11 in 1999 to 1.31 in 2016. In women, the SII for income increased from 0.1% in 1999 to 2.4% in 2016 and the RII for income increased from 1.39 in 1999 to 2.25 in 2016. CONCLUSION: Pro-rich socioeconomic inequalities in smoking prevalence were found in men and women. Socioeconomic inequalities in smoking have increased in parallel with the implementation of tobacco control policies. Tobacco control policies should be developed to decrease socioeconomic inequalities in cigarette use in Korea.

Differences in Adolescent E-cigarette and Cigarette Prevalence in Two Policy Environments: South Korea and the United States.

Introduction: In the context of different regulatory environments, different patterns of e-cigarette use have emerged among adolescents worldwide. The United States and South Korea are two examples, the latter of which has maintained much more extensive regulation of e-cigarettes. Methods: This analysis compares the prevalence of e-cigarette and conventional cigarette use between 2011 and 2015 from the Korean Youth Risk Behavior Web-based Survey and the U.S. National Youth Tobacco Survey, both nationally representative samples of middle and high school students that use similar questions. Results: E-cigarette prevalence (past 30 days) among South Korean adolescents decreased from 4.7% in 2011 (95% confidence interval [CI]: 4.4-5.0) to 4.0% (3.7-4.3) in 2015 but increased dramatically among US adolescents from 0.9% (0.7-1.2) to 11.2% (9.9-12.7). Cigarette prevalence (past 30 days) decreased in South Korea from 12.1% (11.6-12.7) to 7.8% (CI: 7.3-8.3) and in the United States from 11.1% (9.5-12.6) to 6.1% (5.1-7.3). Combined prevalence of cigarette and e-cigarette use (adjusting for dual users) decreased in South Korea from 13.2% (12.7-13.8) to 8.5% (8.0-9.1) but increased in the United States from 11.3% (9.7-12.9) to 14.0% (12.4-15.7). Conclusions: In South Korea, where e-cigarettes are extensively regulated, adolescent e-cigarette use remained stable at a low level, whereas in the United States, where e-cigarette regulation has been limited, e-cigarette use increased. Combined e-cigarette plus cigarette use declined in South Korea whereas it increased in the United States. The restrictive policies in South Korea likely contributed to lower overall product use. Implications: This paper compared the strength of regulation of South Korea and the United States with the prevalence of adolescents' e-cigarette and cigarette use and suggests that more restrictive policies likely to contribute to lower e-cigarette use and overall use of e-cigarette and cigarette.

Association of Alcohol Drinking Patterns With Presence of Impaired Fasting Glucose and Diabetes Mellitus Among South Korean Adults.

BACKGROUND: We aimed to investigate the association between alcohol drinking patterns and the presence of impaired fasting glucose (IFG) and diabetes mellitus (DM). METHODS: We used data from the Korean National Health and Nutrition Examination Survey, 2010-2014. The participants were aged ≥30 years and had no previous diagnosis of DM. High-risk drinking was defined as alcohol consumption of ≥7 glasses at a sitting for men, and ≥5 glasses for women. After adjusting for confounding factors, a polychotomous logistic regression analysis was performed to assess the association of drinking patterns with IFG and DM. RESULTS: For men, high-risk drinking was associated with higher odds ratios (ORs) of IFG (2-4/month, OR 1.51; 95% confidence interval [CI], 1.13-2.04; 2-3/week, OR 1.79; 95% CI, 1.38-2.33; and ≥4/week, OR 2.24; 95% CI, 1.65-3.03) and of DM (2-4/month, OR 2.12; 95% CI, 1.20-3.77; 2-3/week, OR 1.78; 95% CI, 1.05-3.03; and ≥4/week, OR 2.98; 95% CI, 1.72-5.17). For women, high-risk drinking was associated with higher risk of IFG (2-4/month, OR 1.51; 95% CI, 1.04-2.21; 2-3/week, OR 3.19; 95% CI, 2.20-4.64; and ≥4/week, OR 2.23; 95% CI, 1.23-4.06), but not of DM, compared with non-high-risk drinkers who consumed alcohol ≤1 day/month. Non-high-risk drinkers who consumed alcohol ≥4 days/week had higher ORs of DM in men, but lower ORs of DM in women compared with non-high risk drinkers who consumed alcohol ≤1 day/month. CONCLUSIONS: Compared with non-high-risk alcohol drinking, even occasional high-risk alcohol drinking was associated with a higher risk of IFG in men and women, and DM in men. Nearly daily non-high-risk alcohol drinking was associated with a higher risk of DM in men and lower risk of DM in women.

Trends in the ease of cigarette purchase among Korean adolescents: evidence from the Korea youth risk behavior web-based survey 2005-2016.

BACKGROUND: According to the Juvenile Protection Act in Korea, no one is allowed to sell, rent, or distribute tobacco products to adolescents. Furthermore, the Framework Convention on Tobacco Control Article 16 prohibits the sale of tobacco products to minors. In this study, we investigated the trends in and associated factors of the ease of cigarette purchase among Korean adolescents from 2005 to 2016. METHODS: The analyses were based on the data of the Korea Youth Risk Behavior Web-based Survey. We estimated the trends in the ease of cigarette purchase from 2005 to 2016 and evaluated associated factors. Ease of cigarette purchase was defined as the proportion of adolescents who were able to purchase cigarettes from among those who had tried to purchase cigarettes in the past 30 days. RESULTS: The ease of cigarette purchase began decreasing since 2008 (81.3%) compared to 2005 (83.9%). It decreased to 76.5% in 2013 and further decreased to 71.4% in 2016. The ease of cigarette purchase increased for adolescents who were in higher grades, smoked larger amounts of cigarettes per day, lived in metropolitan cities, had problematic drinking in the past year, and had close friends who smoked. It decreased in adolescents who had current smokers among their family members. CONCLUSIONS: Although the proportion of adolescents who were able to purchase cigarettes significantly decreased starting in 2008, more than 70% of Korean adolescents can still purchase cigarettes. Enforcement of the Juvenile Protection Act must be strengthened in order to prevent cigarette use among adolescents.

Azo-dyes based small bifunctional molecules for metal chelation and controlling amyloid formation.

Chemical tools are needed to discover new effective drugs for tackling multifaceted complex neurodegenerative diseases like Alzheimer's disease (AD). Multifunctional nature of two compounds, 5-((4-nitro-phenyl)diazenyl)quinolin-8-ol (HL1) and 4-((4-nitrophenyl)diazenyl)benzene-1,3-diol (HL2) is reported w.r.t. their ability to bind Cu2+ ions and amyloid aggregates related to AD. HL1 and HL2 have half congo-red type azo-stilbene structural framework incorporated with metal chelating groups, designed to chelate metal ions from metal-amyloid species. Metal binding studies of HL1 and HL2 are established by the methods of Job's Plot, UV-vis spectra with metal ions and stability constant determination. In addition, their metal complexes are isolated, purity checked by elemental analysis, spectroscopically characterized and their structural analyses were obtained from DFT based calculations including binding energy determination. Chicken egg white Lysozyme (CEWL) was used as a model peptide for fibrillation studies. HL1 is found as an excellent colorimetric sensor for amyloid fibrils. Inhibitory effect of HL1 and HL2 and their isolated metal complexes L1-Cu and L2-Cu on CEWL fibrillation was studied using ThT and ANS fluorescence assay along with TEM imaging. In addition, the cell toxicity studies on these compounds suggest that although azo dyes may be non-toxic but having a nitro-substitution lead to significant cell toxicity. Overall, these results suggest that this new class of multifunctional small molecules can interact with amyloids as well as metal ions and could be potential anti-aggregation metal chelating agents.

Characteristics of hardcore smokers in South Korea from 2007 to 2013.

BACKGROUND: As the prevalence of smoking decreased in western countries, a significant proportion of smokers appeared to be particularly resistant to quitting- "hardcore" smokers. This study examines the characteristics of hardcore smokers in South Korea. METHODS: We used the data from 2007 to 2013 from the Korea National Health and Nutrition Examination Survey. Hardcore smoking was defined as (1) smoking >15 cigarettes per day, (2) having no plans of quitting, and (3) having made no attempts to quit. Multiple logistic regression analyses were used to investigate the association between various sociodemographic variables and hardcore smoking. RESULTS: The proportion of hardcore smokers among smokers did not change significantly from 23.1% in 2007 to 23.0% in 2013. None of the three characteristics of hardcore smokers for either gender showed a significant change from 2007 to 2013. Multiple logistic regression analysis showed that hardcore smokers were 1.64 times (95% confidence interval [CI], 1.28-2.11) greater among those aging 40-49 years than among those aging 19-29 years, and four times greater among men than women. Never-married smokers were less likely to be hardcore smokers than married ones (odds ratio 0.79; 95% CI, 0.66-0.96). Household income and education level did not have any significant association with the likelihood of a hardcore smoker. CONCLUSIONS: Hardcore smoking was more prevalent among men, unmarried men and those aging 40-49 years.

Neo-Marxian social class inequalities in self-rated health among the employed in South Korea: the role of material, behavioral, psychosocial, and workplace environmental factors.

BACKGROUND: The aim of this study was to examine the pattern of social inequality in self-rated health among the employed using the Wright's social class location indicator, and to assess the roles of material, behavioral, psychosocial, and workplace environmental factors as mediating factors in explaining the social class inequality in self-rated health in South Korea. METHODS: This study used data from the 4th Korea National Health and Nutrition Examination Survey from 2007 to 2009. Study subjects included the employed population of 4392 men and 3309 women aged 19-64 years. Subjects were classified into twelve social class positions based on the Wright's social class map. The health outcome was self-rated health. Material, psychosocial, behavioral, and workplace environmental factors were considered as potential mediators in explaining social class health inequality. We calculated prevalence ratios of poor self-rated health according to social class, adjusted for age and mediating factors using Poisson regression models. RESULTS: Nonskilled workers and petty bourgeoisie reported worse self-rated health than other social classes among men. The age-adjusted prevalence of petty bourgeoisie and nonskilled workers were about four-fold greater than that of managers. Expert supervisors in the contradictory class location had a greater prevalence of poor self-rated health than experts in men. In women, the prevalence of poor self-rated health was greater in most social classes than their male counterparts, while the differences among social classes within women were not statistically significant. Workplace environmental factors explained the social class inequality by from 24 to 31% in nonskilled and skilled workers and nonskilled supervisors, respectively, and material factors showed an explanatory ability of about 8% for both nonskilled workers and petty bourgeoisie in men. CONCLUSIONS: We showed the inequality in self-rated health according to the Wright's social class in an industrialized Asian country. Policy efforts to improve workplace environments in nonskilled and skilled workers and nonskilled supervisors would have a moderate effect on reducing the magnitude of social class inequality in self-rated health. Furthermore, the means to improve power relations in the workplace should be devised to further reduce the social class inequalities in health.

Decomposition of educational differences in life expectancy by age and causes of death among South Korean adults.

BACKGROUND: Decomposition of socioeconomic inequalities in life expectancy by ages and causes allow us to better understand the nature of socioeconomic mortality inequalities and to suggest priority areas for policy and intervention. This study aimed to quantify age- and cause-specific contributions to socioeconomic differences in life expectancy at age 25 by educational level among South Korean adult men and women. METHODS: We used National Death Registration records in 2005 (129,940 men and 106,188 women) and national census data in 2005 (15, 215, 523 men and 16,077,137 women aged 25 and over). Educational attainment as the indicator of socioeconomic position was categorized into elementary school graduation or less, middle or high school graduation, and college graduation or higher. Differences in life expectancy at age 25 by educational level were estimated by age- and cause-specific mortality differences using Arriaga's decomposition method. RESULTS: Differences in life expectancy at age 25 between college or higher education and elementary or less education were 16.23 years in men and 7.69 years in women. Young adult groups aged 35-49 in men and aged 25-39 in women contributed substantially to the differences between college or higher education and elementary or less education in life expectancy. Suicide and liver disease were the most important causes of death contributing to the differences in life expectancy in young adult groups. For older age groups, cerebrovascular disease and lung cancer were important to explain educational differential in life expectancy at 25-29 between college or higher education and middle or higher education. CONCLUSIONS: The contribution of the causes of death to socioeconomic inequality in life expectancy at age 25 in South Korea varied by age groups and differed by educational comparisons. The age specific contributions for different causes of death to life expectancy inequalities by educational attainment should be taken into account in establishing effective policy strategies to reduce socioeconomic inequalities in life expectancy.