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Dive into the research topics where Sandy Liles is active.

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Featured researches published by Sandy Liles.


PLOS ONE | 2014

Cigarette Smoke Toxins Deposited on Surfaces: Implications for Human Health

Manuela Martins-Green; Neema Adhami; Michael Frankos; Mathew Valdez; Benjamin Goodwin; Julia G. Lyubovitsky; Sandeep Dhall; Monika Garcia; Ivie Egiebor; Bethanne Martinez; Harry W. Green; Christopher Havel; Lisa Yu; Sandy Liles; Georg E. Matt; Hugo Destaillats; Mohammed Sleiman; Laura A. Gundel; Neal L. Benowitz; Peyton Jacob; Melbourne F. Hovell; Jonathan P. Winickoff; Margarita C. Currás-Collazo

Cigarette smoking remains a significant health threat for smokers and nonsmokers alike. Secondhand smoke (SHS) is intrinsically more toxic than directly inhaled smoke. Recently, a new threat has been discovered – Thirdhand smoke (THS) – the accumulation of SHS on surfaces that ages with time, becoming progressively more toxic. THS is a potential health threat to children, spouses of smokers and workers in environments where smoking is or has been allowed. The goal of this study is to investigate the effects of THS on liver, lung, skin healing, and behavior, using an animal model exposed to THS under conditions that mimic exposure of humans. THS-exposed mice show alterations in multiple organ systems and excrete levels of NNAL (a tobacco-specific carcinogen biomarker) similar to those found in children exposed to SHS (and consequently to THS). In liver, THS leads to increased lipid levels and non-alcoholic fatty liver disease, a precursor to cirrhosis and cancer and a potential contributor to cardiovascular disease. In lung, THS stimulates excess collagen production and high levels of inflammatory cytokines, suggesting propensity for fibrosis with implications for inflammation-induced diseases such as chronic obstructive pulmonary disease and asthma. In wounded skin, healing in THS-exposed mice has many characteristics of the poor healing of surgical incisions observed in human smokers. Lastly, behavioral tests show that THS-exposed mice become hyperactive. The latter data, combined with emerging associated behavioral problems in children exposed to SHS/THS, suggest that, with prolonged exposure, they may be at significant risk for developing more severe neurological disorders. These results provide a basis for studies on the toxic effects of THS in humans and inform potential regulatory policies to prevent involuntary exposure to THS.


American Journal of Health Promotion | 2010

Culturally Tailored Aerobic Exercise Intervention for Low-income Latinas

Melbourne F. Hovell; Mary M. Mulvihill; Michael J. Buono; Sandy Liles; Debra H. Schade; Tabitha A. Washington; Ruth Manzano; James F. Sallis

Purpose. To determine the efficacy of community-based, culturally tailored exercise intervention on the moderate and vigorous physical activity and physiologic outcomes of low-income Latino women (Latinas). Design. A randomized trial contrasted safety education to an aerobic dance intervention. Setting. Interventions were held in a “store-front” exercise site near a community clinic. Subjects. Sedentary low-income Latinas (N = 151; 18—55 years; 70% overweight/obese) were recruited. Retention was 91% for follow-up measures. Intervention. Three sessions per week of supervised aerobic dance were provided for 6 months. Controls attended 18 safety education sessions over 6 months. Measures. Physical activity and aerobic fitness (VO2max) were primary outcomes. Results. Participants in the exercise group reported more vigorous exercise (p < .001) and walking (p = .005) at post-test than controls. Aerobic dance and unsupervised activity resulted in a five-fold greater increase in relative VO2max compared with controls (p < .001). Although exercise and fitness decreased at follow-up, vigorous exercise (p = .001) and relative VO2max (p < .001) remained higher in the exercise group, suggesting maintenance at 1 year. Conclusion. Culturally tailored aerobic dance can increase vigorous physical activity, possibly generalizing to walking, and the combination can improve cardiorespiratory fitness in low-income, overweight, sedentary Latinas.


American Journal of Health Promotion | 2006

Promoting Stair Use by Modeling: An Experimental Application of the Behavioral Ecological Model

Marc A. Adams; Melbourne F. Hovell; Veronica L. Irvin; James F. Sallis; Karen J. Coleman; Sandy Liles

Purpose. This study evaluated the effect of behavioral modeling and social factors promoting stair use. Design. Alternating baseline and intervention phase experimental design. Setting. San Diego International Airport, San Diego, California. Subjects. Stair use was coded for 15,574 filmed participants. Intervention. This study compared the effects of three types of behavioral modeling: natural models (i.e., passersby), single experimental model (i.e., confederate), and confederate model pairs providing verbal prompts. Measures. Variables were coded based on systematic observation of videotapes, including demographics, day and time, and the following indicators of physical and social reinforcement contingencies: dress, luggage, children, social group, and speed. Reliability ranged from .64 to .88. Analysis. Bivariate and logistic regression models stratified by gender. Results. Stair use increased over baseline by 102.6% with no model present and by 61.8% in the presence of natural models for men and women (p < .001). Controlling for multiple covariates, the odds ratios for stair use ranged from 1.76 to 2.93 for men and from 1.82 to 2.54 for women across the levels with natural and confederate models present (all p < .001). Conclusion. Modeling can prompt stair use, and findings for social and environmental reinforcement contingencies support the Behavioral Ecological Model. Modeling may explain partial maintenance of stair use in public areas after removal of prompts (e.g., signs, banners). Results inform interventions for increasing physical activity as part of daily routines.


Nicotine & Tobacco Research | 2007

The Variability of Urinary Cotinine Levels in Young Children: Implications for Measuring ETS Exposure

Georg E. Matt; Melbourne F. Hovell; Penelope J. E. Quintana; Joy M. Zakarian; Sandy Liles; Susan B. Meltzer; Neal L. Benowitz

This study examined the within-subject variability of urinary cotinine levels in young children (aged = 0.6-7.2 years) of smoking parents to determine the number of urine samples needed to provide accurate estimates of exposure to environmental tobacco smoke (ETS) for different time intervals. Secondary analyses were conducted of five independent studies (N = 376), in which multiple urinary cotinine measures had been collected over time periods up to 13 months. Over measurement periods of 4-15 days, the within-subject cotinine levels varied 3-5 times more than would be expected based on measurement error alone. Over 7-13 months, the within-subject variability was 10-20 times higher than would be expected based on the measurement error. Findings indicated that cotinine measures from single urine samples provided highly accurate estimates of only recent exposure (i.e., 2-3 days; rho = 0.99). To achieve similarly precise estimates of the mean cotinine level of an individual child over 4-15 days, up to nine urine samples may be necessary. Up to 12 urine samples may be required to achieve similarly precise estimates of ETS exposure over a 4- to 13-month period. Epidemiologic and clinical research on ETS exposure in children can benefit from multiple urine samples (a) to accurately measure average exposure at the level of the individual child, (b) to describe temporal patterns, (c) to detect incidences of peak exposure that would remain underrecognized if monitoring is limited to a single time point, and (d) to establish stable baseline levels and endpoints based on urine samples collected over clinically relevant time periods.


Violence Against Women | 2006

Evaluation of a Police and Social Services Domestic Violence Program: Empirical Evidence Needed to Inform Public Health Policies

Melbourne F. Hovell; Arlene G. Seid; Sandy Liles

The Family Violence Response Team (FVRT) responded to police calls for domestic violence and provided services to victims. Police records were followed for (a) 327 FVRT clients with an index police visit in 1998 and (b) 498 nonconcurrent controls with an index visit in 1997. Except for marriage, no demographic characteristics were associated with batterer recidivism, as measured by police calls. The between-group odds ratio (OR) suggested that FVRT clients experienced a 1.7 (95% Confidence Interval [CI]: 1.2 to 2.5) times greater recidivism rate than controls. Although increased reporting cannot be ruled out, results raise concerns about the effects of domestic violence interventions.


Nicotine & Tobacco Research | 2014

Children’s Exposure to Secondhand and Thirdhand Smoke Carcinogens and Toxicants in Homes of Hookah Smokers

Nada Kassem; Reem M. Daffa; Sandy Liles; Sheila R. Jackson; Noura O. Kassem; Maram A. Younis; Setoo Mehta; Menglan Chen; Peyton Jacob; Carmella Sg; Dale A. Chatfield; Neal L. Benowitz; Georg E. Matt; Stephen S. Hecht; Melbourne F. Hovell

INTRODUCTION We examined homes of hookah-only smokers and nonsmokers for levels of indoor air nicotine (a marker of secondhand smoke) and indoor surface nicotine (a marker of thirdhand smoke), child uptake of nicotine, the carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and the toxicant acrolein by analyzing their corresponding metabolites cotinine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and NNAL-glucuronides (total NNAL) and 3-hydroxypropylmercapturic acid. METHODS Data were collected at 3 home visits during a 7-day study period from a convenience sample of 24 households with a child 5 years or younger. Three child urine samples and 2 air and surface samples from the living room and the child bedroom were taken in homes of nonsmokers (n = 5) and hookah-only smokers (n = 19) comprised of daily hookah smokers (n = 8) and weekly/monthly hookah smokers (n = 11). RESULTS Nicotine levels in indoor air and on surfaces in the child bedrooms in homes of daily hookah smokers were significantly higher than in homes of nonsmokers. Uptake of nicotine, NNK, and acrolein in children living in daily hookah smoker homes was significantly higher than in children living in nonsmoker homes. Uptake of nicotine and NNK in children living in weekly/monthly hookah smoker homes was significantly higher than in children living in nonsmoker homes. CONCLUSIONS Our data provide the first evidence for uptake of nicotine, the tobacco-specific lung carcinogen NNK, and the ciliatoxic and cardiotoxic agent acrolein in children living in homes of hookah smokers. Our findings suggest that daily and occasional hookah use in homes present a serious, emerging threat to childrens long-term health.


Chest | 2011

Providing Coaching and Cotinine Results to Preteens to Reduce Their Secondhand Smoke Exposure: A Randomized Trial

Melbourne F. Hovell; Dennis R. Wahlgren; Sandy Liles; Jennifer A. Jones; Suzanne C. Hughes; Georg E. Matt; Ming Ji; Christina N. Lessov-Schlaggar; Gary E. Swan; Dale A. Chatfield; Ding Ding

BACKGROUND Secondhand smoke exposure (SHSe) poses health risks to children living with smokers. Most interventions to protect children from SHSe have coached adult smokers. This trial determined whether coaching and cotinine feedback provided to preteens can reduce their SHSe. METHODS Two hundred one predominantly low-income families with a resident smoker and a child aged 8 to 13 years who was exposed to two or more cigarettes per day or had a urine cotinine concentration ≥ 2.0 ng/mL were randomized to control or SHSe reduction coaching groups. During eight in-home sessions over 5 months, coaches presented to the child graphic charts of cotinine assay results as performance feedback and provided differential praise and incentives for cotinine reductions. Generalized estimating equations were used to determine the differential change in SHSe over time by group. RESULTS For the baseline to posttest period, the coaching group had a greater decrease in both urine cotinine concentration (P = .039) and reported child SHSe in the number of cigarettes exposed per day (child report, P = .003; parent report, P = .078). For posttest to month 12 follow-up, no group or group by time differences were obtained, and both groups returned toward baseline. CONCLUSIONS Coaching preteens can reduce their SHSe, although reductions may not be sustained without ongoing counseling, feedback, and incentives. Unlike interventions that coach adults to reduce child SHSe, programs that increase child avoidance of SHSe have the potential to reduce SHSe in all settings in which the child is exposed, without requiring a change in adult smoking behavior.


Nicotine & Tobacco Research | 2009

Parent quit attempts after counseling to reduce children's secondhand smoke exposure and promote cessation: Main and moderating relationships

Sandy Liles; Melbourne F. Hovell; Georg E. Matt; Joy M. Zakarian; Jennifer A. Jones

INTRODUCTION This study explored predictors of smoking quit attempts in a sample of low-income smoking mothers who participated in a randomized trial of a 6-month, 14-session counseling intervention to decrease their childrens secondhand smoke exposure (SHSe) and eliminate smoking. METHODS Measures were taken at baseline and at 3, 6, 12, and 18 months on 150 mothers who exposed their children (aged <4 years) to > or = 10 cigarettes/week in the home. Reported 7-day quits were verified by saliva cotinine or urine anabasine and anatabine levels. RESULTS There were few quits longer than 6 months. Mothers in the counseling group reported more 24-hr quits (p = .019) and more 7-day quits (p = .029) than controls. Multivariate modeling revealed that having quit for at least 24 hr in the year prior to baseline and the number of alternative cessation methods ever tried were predictive of the longest quit attempt during the 18-month study. Mothers in the counseling group who at baseline felt SHSe posed a health risk for their children or who at baseline had more permissive home smoking policies had longer quit attempts. DISCUSSION Results confirm that attempts to quit smoking predict additional quit attempts. This suggests that practice may be necessary for many people to quit smoking permanently. Findings of interaction analyses suggest that participant factors may alter the effects of treatment procedures. Failure to account for or employ such factors in the analysis or design of community trials could confound the results of intervention trials.


Biomarkers | 2006

Evaluation of urinary trans-3?-hydroxycotinine as a biomarker of children's environmental tobacco smoke exposure

G. E. Matt; P. J. E. Quintana; Sandy Liles; Mel Hovell; Joy M. Zakarian; Peyton Jacob; Neal L. Benowitz

Abstract The utility of urinary trans-3′-hydroxy cotinine (3HC) as a biomarker of environmental tobacco smoke (ETS) exposure was investigated in comparison with urinary cotinine (COT), the sum (3HC + COT), and ratio of the two nicotine metabolites (3HC/COT). Participants were 150 ETS exposed children (aged 1–44 months) and their parents. Child urine samples were collected during 3weekly baseline assessments and at interviews administered 3, 6, 12, and 18 months after baseline. Findings indicate that 3HC and COT can be measured reliably (rho = 0.96, 0.88) and show equivalent levels of repeated measures stability (rho = 0.71, 0.75). COT, 3HC, and 3HC + COT showed equally strong associations with air nicotine levels, reported ETS contamination, and reported ETS exposure (r=0.60–0.70). The intraclass correlations of 3HC/COT were lower than those for COT or 3HC. Older children had a higher 3HC/COT ratio than younger children (3.5 versus 2.2), and non-Hispanic White children had a higher ratio than African-American children (3.2 versus 1.9). These findings suggest that COT, 3HC, and 3HC + COT are approximately equivalent and equally strong biomarkers of ETS exposure in children. Moreover, 3HC/COT may provide a useful indicator to investigate age- and race-related differences in the metabolism of COT and 3HC.


Cancer Epidemiology, Biomarkers & Prevention | 2014

Benzene Uptake in Hookah Smokers and Non-smokers Attending Hookah Social Events: Regulatory Implications

Nada Kassem; Noura O. Kassem; Sheila R. Jackson; Sandy Liles; Reem M. Daffa; Adam T. Zarth; Maram A. Younis; Steven G. Carmella; C. Richard Hofstetter; Dale A. Chatfield; Georg E. Matt; Stephen S. Hecht; Melbourne F. Hovell

Background: Benzene is a human hematotoxicant and a leukemogen that causes lymphohematopoietic cancers, especially acute myelogenous leukemia. We investigated uptake of benzene in hookah smokers and non-smokers attending hookah social events in naturalistic settings where hookah tobacco was smoked exclusively. Methods: We quantified S-phenylmercapturic acid (SPMA), a metabolite of benzene, in the urine of 105 hookah smokers and 103 non-smokers. Participants provided spot urine samples the morning of and the morning after attending an indoor hookah-only smoking social event at a hookah lounge or in a private home. Results: Urinary SPMA levels in hookah smokers increased significantly following a hookah social event (P < 0.001). This increase was 4.2 times higher after hookah lounge events (P < 0.001) and 1.9 times higher after home events (P = 0.003). In non-smokers, urinary SPMA levels increased 2.6 times after hookah lounge events (P = 0.055); however, similar urinary SPMA levels were detected before and after home events, possibly indicating chronic exposure to benzene (P = 0.933). Conclusions: Our data provide the first evidence for uptake of benzene in hookah smokers and non-smokers exposed to hookah tobacco secondhand smoke at social events in private homes compared with their counterparts in hookah lounges. Hookah tobacco smoke is a source of benzene exposure, a risk factor for leukemia. Impact: Because there is no safe level of exposure to benzene, our results call for interventions to reduce or prevent hookah tobacco use, regulatory actions to limit hookah-related exposure to toxicants including benzene, initiate labeling of hookah-related products, and include hookah smoking in clean indoor air legislation. Cancer Epidemiol Biomarkers Prev; 23(12); 2793–809. ©2014 AACR.

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Georg E. Matt

San Diego State University

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Suzanne C. Hughes

San Diego State University

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Jennifer A. Jones

San Diego State University

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Dale A. Chatfield

San Diego State University

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Nada Kassem

San Diego State University

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John Bellettiere

San Diego State University

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