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Correlates of experimentation with smoking and current cigarette consumption among adolescents

Bonilha,Amanda Gimenes; Ruffino-Netto,Antonio; Sicchieri,Mayara Piani; Achcar,Jorge Alberto; Rodrigues-Júnior,Antonio Luiz; Baddini-Martinez,José
Fonte: Sociedade Brasileira de Pneumologia e Tisiologia Publicador: Sociedade Brasileira de Pneumologia e Tisiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
Relevância na Pesquisa
36.33%
OBJECTIVE: The aim of this study was to analyze social characteristics and stress as correlates of cigarette smoking in adolescence. The main intent was to identify elements that distinguish adolescents who had experimented with smoking and did not progress to regular smoking from those who became current smokers. METHODS: Students at 10 high schools in the city of Ribeirão Preto, Brazil, completed a questionnaire based on an instrument employed in a similar large-scale study. The students were classified as never-smokers or experimenters. The experimenters were subcategorized as having become current smokers or nonprogressors. Analyses were performed using adjusted logistic models. RESULTS: A total of 2,014 students (mean age, 16.2 ± 1.1 years; females, 53%) completed the questionnaire. We categorized 1,283 students (63.7%) as never-smokers, 244 (12.1%) as current smokers, and 487 (24.2%) as nonprogressors. We found that experimentation with smoking was associated with being held back a grade in school (OR = 1.80), alcohol intake (low/occasional, OR = 8.92; high/regular, OR = 2.64)...

Structure of central airways in current smokers and ex-smokers with and without mucus hypersecretion: relationship to lung function.

Mullen, J B; Wright, J L; Wiggs, B R; Paré, P D; Hogg, J C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1987 EN
Relevância na Pesquisa
46.36%
Forty-five patients who underwent thoracotomy and lung resection for tumour were studied to compare the structure of the central airways in current smokers and ex-smokers. The patients were divided into four groups: current smokers with mucus hypersecretion (n = 15), current smokers without mucus hypersecretion (n = 14), ex-smokers with mucus hypersecretion (n = 5), and ex-smokers without mucus hypersecretion (n = 11). Quantitative histological studies of the airway wall showed no difference in gland size, smooth muscle, connective tissue, or Reid index between the groups. The central airways of patients with mucus hypersecretion showed increased mucosal inflammation. The five ex-smokers in whom mucus hypersecretion persisted after they had stopped smoking had both central and peripheral airways affected by the inflammatory response, and these patients also had an abnormal result in the nitrogen washout test.

Relationship between diet and smoking--is the diet of smokers different?

Cade, J E; Margetts, B M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1991 EN
Relevância na Pesquisa
36.38%
STUDY OBJECTIVE--The aim was to compare nutrient intakes of smokers, past smokers, and non-smokers. DESIGN--The study was cross sectional and compared nutrient intake by smoking status using data obtained from a concurrent study of diet. SETTING--The study took place in three towns in England: Ipswich, Wakefield, and Stoke on Trent. PARTICIPANTS--Food records were obtained from 1115 men and 1225 women aged 35 to 54 years, representing response rates of 84-86% in the three towns. MEASUREMENTS AND MAIN RESULTS--Diet was assessed using a 24h food record in household measures. For both men and women vitamin C, total fibre, beta carotene, and vitamin E intakes were lowest in the current smokers and highest in the non-smokers with past smokers having intermediate values. Polyunsaturated/saturated fat ratio was lowest in the current smokers. Men who smoked had higher energy intakes than those who did not. The lower fat intakes of beta carotene, vitamin C, fibre, and polyunsaturated fat in the smokers was due to fewer smokers eating a whole range of foods including fruit, wholemeal bread, cereals, and polyunsaturated margarine. Current smokers had a lower body mass index than non-smokers or past smokers despite their higher energy intakes. CONCLUSIONS--Smokers have different nutrient and food intakes compared with past smokers or non-smokers.

When does the risk of acute coronary heart disease in ex-smokers fall to that in non-smokers? A retrospective study of patients admitted to hospital with a first episode of myocardial infarction or unstable angina.

Robinson, K; Conroy, R M; Mulcahy, R
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1989 EN
Relevância na Pesquisa
36.38%
Nine hundred and seventy eight patients admitted with a first myocardial infarction or episode of unstable angina were studied to determine for how long after they gave up smoking did the risk in ex-smokers continue to resemble those of current smokers. Logistic regression was used to calculate a score, based on a combination of age, cholesterol, and hypertension, that separated current smokers from lifetime non-smokers. When this function was applied to ex-smokers, only those who had given up at least 15 years before the attack had a risk factor profile similar to that of non-smokers. Those who had given up less than five years before the ischaemic attack had a significantly higher level of other risk factors than current smokers; those who had stopped for between five and 15 years had levels similar to those of current smokers. Ex-smokers are at higher risk of acute coronary disease for at least 15 years after stopping, but some immediate reduction in risk is possible.

Body image, body satisfaction, and eating patterns in normal-weight and overweight/obese women current smokers and never-smokers

Pomerleau, Cynthia S.; Saules, Karen
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.33%
In order to explore differences between women smokers and never-smokers in body image and eating patterns, we analyzed data obtained from 587 women (18−55 years old) recruited to participate in laboratory investigations not focused on weight concerns. The sample consisted of 420 current smokers and 167 never-smokers; 44% of each group were overweight or obese (BMI ≥25). Questionnaires included measures of body image, body dissatisfaction, and restrained and disinhibited eating. Smokers did not differ from never-smokers on perceived body shape but endorsed a thinner preferred body shape and scored lower on body satisfaction than never-smokers. Smokers also scored higher on measures of disinhibited eating. Among smokers, those who were overweight/obese scored higher than normal-weight smokers on concerns about post-cessation weight gain and lower on self-efficacy to avoid relapse if weight increased. Our findings suggest that women smokers may require help in attaining a more realistic body image and attention to dysfunctional eating patterns if they are to achieve and maintain a healthful weight and/or to quit smoking successfully. They also indicate that overweight smokers may be at elevated risk of relapse in the face of post-cessation weight gain.

Smoking-related self-efficacy, beliefs, and intention: assessing factorial validity and structural relationships in 9 th–12th grade current smokers in Texas

Sterling, Kymberle Landrum; Diamond, Pamela M.; Mullen, Patricia Dolan; Pallonen, Unto; Ford, Kentya H.; McAlister, Alfred L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.16%
Smoking-related self-efficacy and beliefs about the benefits of smoking are consistently related to intention to continue smoking, a common proximal outcome in youth smoking cessation studies. Some measures of these constructs are used frequently in national and state youth tobacco surveys, despite little evidence of validity for high school smokers. Further, the association of the constructs with intention has not been demonstrated in this group. The factorial validity of the measures and the cross-sectional correlations among self-efficacy, beliefs, and intention were examined among 9th–12th grade current smokers (N=2767, 13.8% reporting smoking ≥1 cigarette in the previous 30 days; mean age 16.2; 61.2% white, 6.2% Black, 17.8% Hispanic, 5.0% Asian, 3.5% other; response rate 70%) from a convenience sample of 22 Texas schools. Confirmatory factor analyses supported evidence of factorial validity for the scales in this sample. Structural equation modeling analyses suggested youth smokers have low confidence in their ability to avoid smoking, believe smoking offers emotional or social benefits, and intend to continue smoking. The scales assess smoking-related self-efficacy, beliefs, and intention in this sample. Prospective studies are needed before intervention development implications are suggested.

Use of Other Tobacco Products among U.S. Adult Cigarette Smokers: Prevalence, Trends and Correlates

Backinger, Cathy L.; Fagan, Pebbles; O’Connell, Mary E.; Grana, Rachel; Lawrence, Deirdre; Bishop, Jennifer Anne; Gibson, James Todd
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.36%
This paper examines the trends in concurrent use of cigarettes and other tobacco and sociodemographic variables associated with concurrent use among adult cigarette smokers in the United States. Data from the 1995/96, 1998, 2000, and 2001/02 Tobacco Use Supplements to the Current Population Survey were used to estimate concurrent use of tobacco among cigarette smokers among adults ages 18 years and older (n for all 4 survey groups = 552,804). Concurrent use of tobacco fluctuated over the survey periods for current smokers and ranged from 3.7% in 1995/96 to 7.9% in 1998. Results from the multivariate logistic regression indicate that male current, daily, and intermittent smokers had substantially higher odds of concurrent use (OR = 12.9, 11.7, 17.2, respectively) than their female counterparts. Age, race/ethnicity, geographic region, income, and survey years were significantly associated with concurrent use among current and daily smokers; for intermittent smokers, these variables and occupation were significantly associated with concurrent use. The strongest correlates for multiple tobacco use among cigarettes smokers were being male and Non-Hispanic White. These factors should be considered when planning tobacco prevention and control efforts. In addition...

Gender Specific Differences in the Pros and Cons of Smoking among Current Smokers in Eastern Kentucky: Implications for Future Smoking Cessation Interventions

Hazen, Dana A.; Mannino, David M.; Clayton, Richard
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.1%
This study investigated gender differences in the perceived “pros” and “cons” of smoking using the constructs of decisional balance (DB) and stage of change from the Transtheoretical Model. The population distribution for stage of change among a population-based, cross-sectional survey of 155 current smokers over 40 years was: precontemplation (22.6%), contemplation (41.9%), preparation (35.5%). Results of stepwise regression models indicated significant gender differences in DB were in the preparation stage of change; scores on the DB measure increased 3.94 points (95% CI: 1.94, 5.93) for male smokers. Interventions targeting the “pros” and “cons” of smoking may need to be gender specific.

Decreased Serum Antibody Responses to Recombinant Pneumocystis Antigens in HIV-Infected and Uninfected Current Smokers▿

Crothers, Kristina; Daly, Kieran R.; Rimland, David; Goetz, Matthew Bidwell; Gibert, Cynthia L.; Butt, Adeel A.; Justice, Amy C.; Djawe, Kpandja; Levin, Linda; Walzer, Peter D.
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.05%
Serologic studies can provide important insights into the epidemiology and transmission of Pneumocystis jirovecii. Exposure to P. jirovecii can be assessed by serum antibody responses to recombinant antigens from the major surface glycoprotein (MsgC), although factors that influence the magnitude of the antibody response are incompletely understood. We determined the magnitudes of antibody responses to P. jirovecii in comparison to adenovirus and respiratory syncytial virus (RSV) in HIV-infected and uninfected patients and identified predictors associated with the magnitude of the response. We performed a cross-sectional analysis using serum samples and data from 153 HIV-positive and 92 HIV-negative subjects enrolled in a feasibility study of the Veterans Aging Cohort 5 Site Study (VACS 5). Antibodies were measured using an enzyme-linked immunosorbent assay (ELISA). Independent predictors of antibody responses were determined using multivariate Tobit regression models. The results showed that serum antibody responses to P. jirovecii MsgC fragments were significantly and independently decreased in current smokers. Antibodies to P. jirovecii also tended to be lower with chronic obstructive pulmonary disease (COPD), hazardous alcohol use...

Oral Iloprost Improves Endobronchial Dysplasia in Former Smokers

Keith, Robert L.; Blatchford, Patrick J.; Kittelson, John; Minna, John D.; Kelly, Karen; Massion, Pierre P.; Franklin, Wilbur A.; Mao, Jenny; Wilson, David O.; Merrick, Daniel T.; Hirsch, Fred R.; Kennedy, Timothy C.; Bunn, Paul A.; Geraci, Mark W.; Mille
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/2011 EN
Relevância na Pesquisa
36.35%
There are no established chemopreventive agents for lung cancer, the leading cause of cancer death in the United States. Prostacyclin levels are low in lung cancer and supplementation prevents lung cancer in preclinical models. We carried out a multicenter double-blind, randomized, phase II placebo-controlled trial of oral iloprost in current or former smokers with sputum cytologic atypia or endobronchial dysplasia. Bronchoscopy was performed at study entry and after completion of six months of therapy. Within each subject, the results were calculated by using the average score of all biopsies (Avg), the worst biopsy score (Max), and the dysplasia index (DI). Change in Avg was the primary end point, evaluated in all subjects, as well as in current and former smokers. The accrual goal of 152 subjects was reached and 125 completed both bronchoscopies (60/75 iloprost, 65/77 placebo). Treatment groups were well matched for age, tobacco exposure, and baseline histology. Baseline histology was significantly worse for current smokers (Avg 3.0) than former smokers (Avg 2.1). When compared with placebo, former smokers receiving oral iloprost exhibited a significantly greater improvement in Avg (0.41 units better, P = 0.010), in Max (1.10 units better...

Risk Factors for Subclinical Carotid Atherosclerosis among Current Smokers

Johnson, Heather M.; Piper, Megan E.; Jorenby, Douglas E.; Fiore, Michael C.; Baker, Timothy B.; Stein, James H.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
46.15%
This study characterized the determinants of carotid atherosclerosis in a large, contemporary sample of current smokers. Associations between risk factors, carotid intima-media thickness (CIMT) and carotid plaque presence were determined by multivariable regression. Subjects included 1,504 current smokers (58% female) who were a median (interquartile range) of 44.7 (38–53) years old and smoked 25 (15–40) pack-years; 55% had plaque. Pack-years, age, male sex, non-white race, body-mass index, systolic blood pressure, small low-density lipoproteins (LDL), and total high-density lipoproteins were independently associated with CIMT (model R2=0.434, p<0.001). Pack-years (OR 1.14 per 10 pack-years, p=0.001), age (OR 1.75 per 10 years, p<0.001), body-mass index (OR 0.91 per 5 kg/m2, p =0.035), and small LDL (OR 1.11 per 100 nmol/L, p<0.001), were independently associated with carotid plaque presence (model X2=210.7, p<0.001). The association between pack-years and carotid plaque was stronger in women (OR 1.09 per 10 pack-years, pinteraction=0.018).

Intent to quit among daily and non-daily college student smokers

Pinsker, E. A.; Berg, C. J.; Nehl, E. J.; Prokhorov, A. V.; Buchanan, T. S.; Ahluwalia, J. S.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.33%
Given the high prevalence of young adult smoking, we examined (i) psychosocial factors and substance use among college students representing five smoking patterns and histories [non-smokers, quitters, native non-daily smokers (i.e. never daily smokers), converted non-daily smokers (i.e. former daily smokers) and daily smokers] and (ii) smoking category as it relates to readiness to quit among current smokers. Of the 4438 students at six Southeast colleges who completed an online survey, 69.7% (n = 3094) were non-smokers, 6.6% (n = 293) were quitters, 7.1% (n = 317) were native non-daily smokers, 6.4% (n = 283) were converted non-daily smokers and 10.2% (n = 451) were daily smokers. There were differences in sociodemographics, substance use (alcohol, marijuana, other tobacco products) in the past 30 days and psychosocial factors among these subgroups of students (P < 0.001). Among current smokers, there were differences in cigarettes smoked per day, recent quit attempts, self-identification as a smoker, self-efficacy and motivation to quit (P < 0.001). After controlling for important factors, converted non-daily smokers were more likely to be ready to quit in the next month versus native non-daily smokers (OR = 2.15, CI 1.32–3.49...

Pulmonary Tuberculosis and Lung Cancer Risk in Current Smokers: The Seoul Male Cancer Cohort Study

Bae, Jong-Myon; Li, Zhong-Min; Shin, Myung-Hee; Kim, Dong-Hyun; Lee, Moo-Song; Ahn, Yoon-Ok
Fonte: The Korean Academy of Medical Sciences Publicador: The Korean Academy of Medical Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.24%
Authors evaluated pulmonary tuberculosis (PTB) history as a risk factor for lung cancer in current male smokers in a prospective, population-based cohort study. The subjects were the 7,009 males among the participants in the Seoul Male Cancer Cohort Study for whom there was full information on PTB history and smoking habits. With a 16-yr follow-up, 93 cases of lung cancer occurred over the 99,965 person-years of the study. The estimated relative risk (RR) of PTB history of current smokers in lung cancer after adjusting for three confounders - intake of coffee and tomatoes, and age at entry - was 1.85 (95% CI: 1.08-3.19). The observed joint RRs and attributable risks (ARs) across strata of three confounders were greater than the expected, indicating a positive interaction. Thus a history of PTB in current smokers may be another risk factor for lung cancer. Based on a synergic interaction, a heavy male smoker with a PTB history would be expected to belong to the group at high risk of lung cancer.

Association between daily cigarette consumption and hypertension moderated by CYP2A6 genotypes in Chinese male current smokers

Liu, T; Tyndale, RF; David, SP; Wang, H; Yu, X-Q; Chen, W; Wen, X-Z; Chen, W-Q
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.1%
The purpose of this study was to assess whether cytochrome P450 enzyme 2A6 (CYP2A6) genotypes moderate the association between smoking and hypertension. In this study, 954 Chinese male current smokers from a community-based chronic disease screening project in Guangzhou were interviewed with a structured questionnaire about socio-demographic status, smoking and other health-related behaviors. Blood was collected for DNA extraction and CYP2A6 genotyping. Hypertension was defined according to 2007 ESH-ESC Practice Guidelines. A multivariate logistic regression was performed to examine the interaction between smoking quantity and CYP2A6 genotypes on hypertension after adjusting for age, education level and other potential confounders. Multivariate analyses indicated that smoking more than 15 cigarettes per day significantly increased the risk of hypertension (odds ratio (OR)=1.59, 95% confidence interval (CI)=1.21-2.10) compared with smoking 1-15 cigarettes per day, and further suggested that smoking interacted with normal CYP2A6 metabolizer genotype to increase the risk of hypertension. Smokers consuming more than 15 cigarettes per day with normal CYP2A6 metabolizer genotypes had the highest risk of hypertension (OR=2.04, 95% CI=1.11-3.75) compared with those consuming 1-15 cigarettes per day with slower CYP2A6 metabolizer genotypes. These findings demonstrated that smoking quantity was positively associated with hypertension and that CYP2A6 genotypes may moderate this relationship.

Impact of smoking cessation on global gene expression in the bronchial epithelium of chronic smokers

Zhang, Li; Lee, Jack; Tang, Hongli; Fan, You-Hong; Xiao, Lianchun; Ren, Hening; Kurie, Jonathan; Morice, Rodolfo C; Hong, Waun Ki; Mao, Li
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.34%
Cigarette smoke is the major cause of lung cancer and can interact in complex ways with drugs for lung cancer prevention or therapy. Molecular genetic research promises to elucidate the biologic mechanisms underlying divergent drug effects in smokers versus non-smokers and to help in developing new approaches for controlling lung cancer. The present study compared global gene expression profiles (determined via Affymetrix microarray measurements in bronchial epithelial cells) between chronic smokers, former smokers, and never smokers. Smoking effects on global gene expression were determined from a combined analysis of three independent datasets. Differential expression between current and never smokers occurred in 591 of the 13,902 genes measured on the microarrays (P < 0.01 and >2 fold change; pooled data)—a profound effect. In contrast, differential expression between current and former smokers occurred in only 145 of the measured genes (P < 0.01 and >2 fold change; pooled data). Nine of these 145 genes showed consistent and significant changes in each of the three datasets (P < 0.01 and >2 fold change), with 8 being down-regulated in former smokers. Seven of the 8 down-regulated genes, including CYP1B1 and 3 AKR genes, influence the metabolism of carcinogens and/or therapeutic/chemopreventive agents. Our data comparing former and current smokers allowed us to pinpoint the genes involved in smoking–drug interactions in lung cancer prevention and therapy. These findings have important implications for developing new targeted and dosing approaches for prevention and therapy in the lung and other sites...

Isolated and Skeptical: Social Engagement and Trust in Information Sources Among Smokers

Finney Rutten, Lila J.; Blake, Kelly; Hesse, Bradford W.; Ackerson, Leland K.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/2011 EN
Relevância na Pesquisa
36.45%
Our study compared indicators of social engagement and trust among current, former, and never smokers. Multinomial regression analyses of data from the 2005 U.S. Health Information National Trends Survey (n=5586) were conducted to identify independent associations between social engagement, trust in health information sources, and smoking status. Never smokers (odds ratio (OR)=2.08) and former smokers (OR=2.48) were significantly more likely to belong to community organizations than current smokers. Never (OR=4.59) and former smokers (OR=1.96) were more likely than current smokers to attend religious services. Never smokers (OR=1.38) were significantly more likely than current smokers to use the Internet. Former smokers (OR=1.41) were more likely than current smokers to be married. Compared to current smokers, never smokers were significantly more likely to trust health care professionals (OR=1.52) and less likely to trust the Internet (OR=0.59) for health information. Current smokers are less socially engaged and less trusting of information resources than non-smokers.

Tobacco smoking and all-cause mortality in a large Australian cohort study: findings from a mature epidemic with current low smoking prevalence

Banks, Emily; Joshy, Grace; Weber, Marianne F; Liu, Bette; Grenfell, Robert; Egger, Sam; Paige, Ellie; Lopez, Alan D; Sitas, Freddy; Beral, Valerie
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.45%
BACKGROUND The smoking epidemic in Australia is characterised by historic levels of prolonged smoking, heavy smoking, very high levels of long-term cessation, and low current smoking prevalence, with 13% of adults reporting that they smoked daily in 2013. Large-scale quantitative evidence on the relationship of tobacco smoking to mortality in Australia is not available despite the potential to provide independent international evidence about the contemporary risks of smoking. METHODS This is a prospective study of 204,953 individuals aged ≥45 years sampled from the general population of New South Wales, Australia, who joined the 45 and Up Study from 2006-2009, with linked questionnaire, hospitalisation, and mortality data to mid-2012 and with no history of cancer (other than melanoma and non-melanoma skin cancer), heart disease, stroke, or thrombosis. Hazard ratios (described here as relative risks, RRs) for all-cause mortality among current and past smokers compared to never-smokers were estimated, adjusting for age, education, income, region of residence, alcohol, and body mass index. RESULTS Overall, 5,593 deaths accrued during follow-up (874,120 person-years; mean: 4.26 years); 7.7% of participants were current smokers and 34.1% past smokers at baseline. Compared to never-smokers...

Expression of ErbB receptors and mucins in the airways of long term current smokers

O'Donnell, R; Richter, A; Ward, J; Angco, G; Mehta, A; Rousseau, K; Swallow, D; Holgate, S; Djukanovic, R; Davies, D; Wilson, S
Fonte: BMJ Group Publicador: BMJ Group
Tipo: Artigo de Revista Científica
Publicado em /12/2004 EN
Relevância na Pesquisa
46.1%
Background: Airway epithelial goblet cell hyperplasia is known to occur in chronic smokers. Although the epidermal growth factor receptor has been implicated in this process, neither ErbB receptor expression nor the mucosecretory phenotype of the epithelium have been characterised in current smokers.

Elastolytic activity of alveolar macrophages in chronic bronchitis: comparison of current and former smokers.

O'Neill, S; Prichard, J S
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1983 EN
Relevância na Pesquisa
36.42%
We have compared the macrophage elastolytic activity of a group of current and former smokers with irreversible airflow obstruction. Elastolytic activity was determined in an initial bronchoalveolar lavage cell population and in alveolar macrophages cultured for three days, to investigate whether enhanced macrophage elastolytic activity alone is a determining factor in the susceptibility of some smokers to obstructive lung disease. Twenty current smokers and 12 former smokers who had abstained from smoking for at least three years were studied. All patients had spirometric evidence of irreversible air flow obstruction. Current smokers had a cell yield (mean +/- SD) of 138.7 +/- 36.4 X 10(6) cells (alveolar macrophages 94.2% +/- 2.1%) compared with 31.4 +/- 14.1 X 10(6) cells (macrophages 86.5% +/- 4.7%) in former smokers. Elastolytic activity in the initial lavage cell population from current and former smokers, measured with the synthetic elastase substrate succinyl-L-alanyl-L alanyl-L-alanine-p-nitroanilide, and expressed as the equivalent of 1 microgram of porcine pancreatic elastase, was respectively 0.113 +/- 0.003 and 0.096 +/- 0.004 microgram pancreatic elastase/mg cell protein. After three days in culture macrophage elastolytic activity in the current and former smokers' cells was respectively 0.107 +/- 0.006 and 0.011 +/- 0.001 microgram pancreatic elastase/mg cell protein (p less than 0.05). The elastase activity of the cultured alveolar macrophages from five current smokers had the inhibitor profile of a metalloproteinase. Our results indicate that enhanced macrophage elastolytic activity alone is not a determining factor in the susceptibility of some smokers to develop obstructive lung disease.

Misclassification rates for current smokers misclassified as nonsmokers.

Wells, A J; English, P B; Posner, S F; Wagenknecht, L E; Perez-Stable, E J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1998 EN
Relevância na Pesquisa
46.28%
OBJECTIVES: This paper provides misclassification rates for current cigarette smokers who report themselves as nonsmokers. Such rates are important in determining smoker misclassification bias in the estimation of relative risks in passive smoking studies. METHODS: True smoking status, either occasional or regular, was determined for individual current smokers in 3 existing studies of nonsmokers by inspecting the cotinine levels of body fluids. The new data, combined with an approximately equal amount in the 1992 Environmental Protection Agency (EPA) report on passive smoking and lung cancer, yielded misclassification rates that not only had lower standard errors but also were stratified by sex and US minority majority status. RESULTS: The misclassification rates for the important category of female smokers misclassified as never smokers were, respectively, 0.8%, 6.0%, 2.8%, and 15.3% for majority regular, majority occasional, US minority regular, and US minority occasional smokers. Misclassification rates for males were mostly somewhat higher. CONCLUSIONS: The new information supports EPA's conclusion that smoker misclassification bias is small. Also, investigators are advised to pay attention to minority/majority status of cohorts when correcting for smoker misclassification bias.