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155 result(s) for "Stepanov, Irina"
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Switching to cigarette brand variants with different filter ventilation levels: a descriptive analysis
BackgroundRegulation of filter ventilation (FV) has been proposed to reduce misperceptions that ventilation reduces the health risks of smoking. We describe smoking behaviour and exposure after switching to a cigarette brand variant (CBV) with a different FV level.MethodsWave 1 (2013–2014) of the Population Assessment of Tobacco Use and Health Study was merged with FV levels of participants’ CBV and restricted to adults with a usual CBV, smoked daily and included in wave 4 (2016–2017; n=371). Generalised estimation equations method modelled changes in FV and cigarettes per day (CPD), quit interest, total nicotine equivalents (TNE) and total NNAL (biomarker of a tobacco-specific carcinogen). FV change was defined as a change in CBV resulting in a ≥20% increase or decrease in FV. Secondary analyses used FV change based on an increase from <5% to >10% or a decrease from >10% to <5%.ResultsA non-significant pattern indicating an increase of 0.97 and 0.49 CPD was observed among those who switched to a CBV and increased FV by ≥20% and from <5% to >10%, respectively. A non-significant pattern indicating a decrease of 1.31 and 1.97 CPD was observed among those who decreased FV by ≥20% and from >10% to <5%, respectively. Changes in quit interest and biomarkers were also non-significant with one exception: greater reduction in TNE among those who decreased from >10% to <5% FV versus no change (−8.51 vs −0.25 nmol/mg creatinine; p=0.0447).ConclusionsSwitching to CBV with lower FV does not appear to increase exposure and may even reduce exposure for some. Additional investigations are recommended to confirm these descriptive findings.
Risk perceptions and continued smoking as a function of cigarette filter ventilation level among US youth and young adults who smoke
BackgroundWhile evidence demonstrates that the industry’s marketing of cigarettes with higher filter ventilation (FV) misleads adults about their health risks, there is no research on the relationships between FV, risk perceptions and smoking trajectories among youth (ages 12–17) and young adults (ages 18–24).MethodsData on FV levels of major US cigarette brands/sub-brands were merged with the Population Assessment of Tobacco and Health Study to examine whether FV level in cigarettes used by wave 1 youth/young adults (n=1970) predicted continued smoking at waves 2–4, and whether those relationships were mediated by perceived risk of their cigarette brand. FV was modelled based on tertiles (0.2%–11.8%, low; 11.9%–23.2%, moderate; 23.3%–61.1%, high) to predict daily smoking, past 30-day smoking and change in number of days smoking at successive waves.ResultsThe odds of perceiving one’s brand as less harmful than other cigarette brands was 2.21 times higher in the high versus low FV group (p=0.0146). Relationships between FV and smoking outcomes at successive waves were non-significant (all p>0.05).ConclusionYouth and young adults who use higher FV cigarettes perceived their brand as less harmful compared with other brands. However, level of FV was not associated with continued smoking.
Recent Studies on DNA Adducts Resulting from Human Exposure to Tobacco Smoke
DNA adducts are believed to play a central role in the induction of cancer in cigarette smokers and are proposed as being potential biomarkers of cancer risk. We have summarized research conducted since 2012 on DNA adduct formation in smokers. A variety of DNA adducts derived from various classes of carcinogens, including aromatic amines, polycyclic aromatic hydrocarbons, tobacco-specific nitrosamines, alkylating agents, aldehydes, volatile carcinogens, as well as oxidative damage have been reported. The results are discussed with particular attention to the analytical methods used in those studies. Mass spectrometry-based methods that have higher selectivity and specificity compared to 32P-postlabeling or immunochemical approaches are preferred. Multiple DNA adducts specific to tobacco constituents have also been characterized for the first time in vitro or detected in vivo since 2012, and descriptions of those adducts are included. We also discuss common issues related to measuring DNA adducts in humans, including the development and validation of analytical methods and prevention of artifact formation.
Simultaneous analysis of urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, N′-nitrosonornicotine, and cotinine by liquid chromatography-tandem mass-spectrometry
Biomarkers of exposure to harmful tobacco constituents are key tools for identifying individuals at risk and developing interventions and tobacco control measures. However, tobacco biomarker studies are scarce in many parts of the world with high prevalence of tobacco use. Our goal was to establish a robust method for simultaneous analysis of urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), N ′-nitrosonornicotine (NNN), and cotinine at the Advanced Centre for Treatment, Research and Education in Cancer (ACTREC) in Mumbai, India. These biomarkers are validated measures of exposure to the carcinogenic tobacco nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and NNN and the addictive alkaloid nicotine, respectively. The established method is characterized by excellent accuracy, linearity, and precision, and was successfully applied to the analysis of 15 smokeless tobacco (SLT) users and 15 non-users of tobacco recruited in Mumbai. This is the first report of establishment of such procedure in a laboratory in India, which offers the first in-country capacity for research on tobacco carcinogenesis in Indian SLT users.
Impact of Watercress Consumption on Antioxidant Defense and Oxidative Stress Among Adults with Different Levels of Exposure to Cigarette Smoke in Chiang Mai, Thailand
Antioxidant intake from natural sources may enhance defense systems against oxidative stress induced by environmental factors such as cigarette smoke. Watercress ( ) is an abundant source of antioxidants. This study aimed to determine the antioxidant effects of watercress consumption in people exposed to cigarette smoke in Chiang Mai, Thailand. Forty-five participants (15 non-smokers, 15 non-smokers with self-reported exposure to secondhand smoke (SHS), and 15 smokers) aged 20-60 years consumed 60 g of fresh watercress with three meals daily for seven days. Clinical characteristics, lipid profiles, total antioxidant capacity, and oxidative stress markers were evaluated before and after the intervention. After 7 days of watercress consumption, body mass index (BMI) and hip circumference significantly decreased among non-smokers. Watercress consumption reduced total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels in smokers and in SHS-exposed non-smokers; however, high-density lipoprotein cholesterol (HDL-C) significantly decreased in SHS-exposed non-smokers. Catalase activity increased, and malondialdehyde levels decreased in all groups. One of the measures of plasma total antioxidant capacity significantly improved in non-smokers. These findings suggest that watercress consumption may improve lipid profiles and mitigate oxidative stress, and that these beneficial effects differ across people with different levels of exposure to cigarette smoke. However, further studies are suggested to clarify these results.
Effects of Drying Methods on the Phytochemical Contents, Antioxidant Properties, and Anti-Diabetic Activity of Nasturtium officinale R.Br. (Betong Watercress) from Southern Thailand
Nasturtium officinale R.Br. (Betong watercress) contains high levels of secondary metabolites that offer health benefits. However, fresh-cut watercress has a short shelf life. This study aimed to assess the effect of drying methods on the phytochemical contents, antioxidant activity, and anti-diabetic activity of Betong watercress. The watercress was dried using three methods: roasting (R, 50 °C, 40 min); roasting and drying (RD, 40 min roasting at 50 °C and 1 h drying at 80 °C); and blanching, roasting, and drying (BRD, 30 s blanching at 80 °C, 20 min roasting at 50 °C, and 1 h drying at 80 °C). Aqueous extracts from each drying method were analyzed for total phenolic content, total flavonoid content, total glucosinolate content, antioxidant activities (FRAP, DPPH, and ABTS assays), and α-amylase enzyme inhibition. From the results, the R method provided the highest level of total phenolic, total flavonoid, and total glucosionolate content compared to the RD and BRD methods. Similarly, antioxidant activities and α-amylase enzyme inhibition were highest in the R method, followed by the RD and BRD methods. Our results demonstrate that roasting of Betong watercress without the addition of blanching or drying effectively preserves the phytochemical contents, antioxidant activities, and anti-diabetic activity.
Harm Perceptions of Tobacco/Nicotine Products and Child Exposure: Differences between Non-Users, Cigarette-Exclusive, and Electronic Cigarette-Exclusive Users
Objective: This study examined caregiver perception of harm and child secondhand exposure to nicotine in a sample of e-cigarette-exclusive, cigarette-exclusive, and non-tobacco/nicotine users (non-users). Methods: Cigarette-exclusive (n = 19), e-cigarette-exclusive (n = 12), and non-users (n = 20) and their children (N = 51, Mage = 10.47) completed self-report questionnaires about perceptions of harm, child secondhand exposure, and provided urine to assess child nicotine exposure (cotinine). ANOVAs examined differences between caregiver use status on tobacco harm perceptions and child cotinine levels. Independent samples t-test compared differences in caregiver-reported child secondhand exposure in the home and car. Results: All 3 caregiver groups rated cigarettes as highly harmful (P = .14), but e-cigarette users rated all 3 types of e-cigarette products (Cartridge-based: P < .001; Tank: P < .001; Box Mod: P < .001) as less harmful than cigarette users and non-users. Caregivers from the e-cigarette user group reported greater child secondhand exposure than caregivers using cigarettes (past 7-day in-home exposure (P = .03); past 7-day exposure in-home + in-car exposure (P = .02); in-home exposure by caregivers and other people exposure (P = .02)). Children from the cigarette user group had significantly higher levels of cotinine (M = 16.6, SD = 21.7) compared to children from the Non-User group (M = .43, SD = .95; P = .001), but no significant difference when compared to children from the E-Cigarette User group (M = 6.5, SD = 13.5). Discussion: In this sample, caregivers who used e-cigarettes perceived them as less harmful, reported using them more frequently at home and in the car, even when their children were present, compared to cigarette users. As a result, children appear to be exposed to nicotine at levels similar to children living with cigarette users. Future caregiver prevention and intervention efforts should target education around the potential harms of secondhand e-cigarette aerosol to children.
Tobacco biomarkers and genetic/epigenetic analysis to investigate ethnic/racial differences in lung cancer risk among smokers
The Multiethnic Cohort Study has demonstrated that African Americans and Native Hawaiians have a higher risk for lung cancer due to cigarette smoking than Whites while Latinos and Japanese Americans have a lower risk. These findings are consistent with other epidemiologic studies in the literature. In this review, we summarize tobacco carcinogen and toxicant biomarker studies and genetic analyses which partially explain these differences. As determined by measurement of total nicotine equivalents in urine, which account for about 85% of the nicotine dose, African Americans take up greater amounts of nicotine than Whites per cigarette while Japanese Americans take up less. There are corresponding differences in the uptake of tobacco smoke carcinogens such as tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, 1,3-butadiene, and other toxic volatiles. The lower nicotine uptake of Japanese Americans is clearly linked to the preponderance of low activity forms of the primary nicotine metabolizing enzyme CYP2A6 in this ethnic group, leading to more unchanged nicotine in the body and thus lower smoking intensity. But the relatively high risk of Native Hawaiians and the low risk of Latino smokers for lung cancer are not explained by these factors. The possible role of epigenetics in modifying lung cancer risk among smokers is also discussed here. The results of these published studies may lead to a better understanding of susceptibility factors for lung cancer in cigarette smokers thus potentially identifying biomarkers that can detect those individuals at highest risk so that preventive approaches can be initiated at an early stage of the lung cancer development process.
Tobacco carcinogen research to aid understanding of cancer risk and influence policy
Education regarding the health effects associated with tobacco use has made important progress worldwide over the last few decades. Still, tobacco remains a significant cause of cancer and other diseases. As a result, significant worldwide morbidity and mortality is still attributable to tobacco use in modern times. Research into tobacco products, the carcinogens they contain, and how users metabolize them is an important benefit to the advancement of research aimed at reducing harm associated with tobacco use. This review summarizes the use of this type of research to study tobacco users’ risk of developing cancer, especially head and neck cancer. In addition, we discuss the use of tobacco research to provide support for increasing levels of federal regulation of tobacco products. Level of Evidence 4.
Bringing attention to e-cigarette pH as an important element for research and regulation
Discussion The variation of pH among e-cigarette brands that contain the same amount of nicotine, and even among different flavors within the same brand, is an important finding. Since pH determines the amount of nicotine that is present in the biologically available unprotonated form, e-cigarettes with the same nicotine content, but different pH, may deliver different doses of nicotine to users. [...]potential pH variations represent an important factor that should be taken into account while designing and interpreting research studies involving e-cigarettes.