Mandibular muscle troponin of the Florida carpenter ant Camponotus floridanus: extending our insights into invertebrate Ca2+ regulation.

Ants use their mandibles for a variety of functions and behaviors. We investigated mandibular muscle structure and function from major workers of the Florida carpenter ant Camponotus floridanus: force-pCa relation and velocity of unloaded shortening of single, permeabilized fibres, primary sequences of troponin subunits (TnC, TnI and TnT) from a mandibular muscle cDNA library, and muscle fibre ultrastructure. From the mechanical measurements, we found Ca2+-sensitivity of isometric force was markedly shifted rightward compared with vertebrate striated muscle. From the troponin sequence results, we identified features that could explain the rightward shift of Ca2+-activation: the N-helix of TnC is effectively absent and three of the four EF-hands of TnC (sites I, II and III) do not adhere to canonical sequence rules for divalent cation binding; two alternatively spliced isoforms of TnI were identified with the alternatively spliced exon occurring in the region of the IT-arm α-helical coiled-coil, and the N-terminal extension of TnI may be involved in modulation of regulation, as in mammalian cardiac muscle; and TnT has a Glu-rich C-terminus. In addition, a structural homology model was built of C. floridanus troponin on the thin filament. From analysis of electron micrographs, we found thick filaments are almost as long as the 6.8 µm sarcomeres, have diameter of ~ 16 nm, and typical center-to-center spacing of ~ 46 nm. These results have implications for the mechanisms by which mandibular muscle fibres perform such a variety of functions, and how the structure of the troponin complex aids in these tasks.

The Effect of Maternal Smoking on Offspring Smoking Is Unrelated to Heritable Personality Traits or Initial Subjective Experiences.

INTRODUCTION: Maternal smoking is a risk factor for offspring smoking. Lifetime maternal smoking vs. prenatal tobacco exposure (PTE) appears to act through different mechanisms. This study tested the hypothesis that maternal smoking measures' effects on offspring smoking could be attributable to hereditary mechanisms: personality traits (novelty-seeking, impulsivity, neuroticism, and self-esteem) and initial subjective smoking experiences (pleasurable, unpleasurable, and dizziness). METHODS: Data were drawn from the Social and Emotional Contexts of Adolescent Smoking Patterns study, an 8-year longitudinal study of 9th or 10th graders at baseline (≈age 15) who experiment with smoking (<100 lifetime cigarettes; N = 594) at baseline. The young adult smoking frequency at the 8-year follow-up (≈age 23) was examined as a function of baseline characteristics (heritable trait, maternal smoking, PTE, and sex) and baseline smoking frequency and nicotine dependence. Structural equation models determined whether the inclusion of each heritable trait among offspring confounded the effects of maternal smoking (PTE or maternal smoking) on offspring smoking and nicotine dependence. RESULTS: Impulsiveness was associated with intermediate adolescent smoking frequency (B = 0.135, SD = 0.043, p = .002) and nicotine dependence (B = 0.012, SD = 0.003, p < .001). Unpleasurable first experience (B = 0.886, SD = 0.374, p = .018) and dizziness (B = 0.629, SD = 0.293, p = .032) showed a trend with intermediate smoking frequency that was nonsignificant after correcting for multiple comparisons. These traits did not confound maternal smoking's effects. CONCLUSIONS: None of the heritable traits examined in this model explained the effect of maternal smoking measures on adolescence or young adulthood offspring smoking. Further research is needed to elucidate the mechanism by which PTE and maternal smoking are linked to offspring smoking. IMPLICATIONS: Prenatal tobacco exposure (PTE) and mother's lifetime smoking present separate and independent risks for offspring smoking; however, their mechanisms seem unrelated to heritable personality traits and initial subjective smoking experiences. These findings have implications for separate screening strategies tailored to different age groups, especially related to PTE's risk of smoking in young adulthood. Additionally, these findings add to the known risks of maternal smoking. Further research is needed to understand the mechanism underlying the risk posed by maternal lifetime smoking and PTE on offspring smoking behavior.

A Network Analysis of Sexually Transmitted Diseases and Online Hookup Sites Among Men Who Have Sex With Men.

BACKGROUND: Sexually transmitted diseases (STDs) are increasing among gay, bisexual, and other men who have sex with men (MSM). Little is known about the use of websites and mobile phone applications to meet sexual partners ("hookup sites") and association with STD diagnoses. METHODS: We performed a demographic and behavioral assessment of 415 MSM presenting to the Rhode Island STD clinic. Bivariate and multivariable analyses assessed associations between using hookup sites and testing positive for syphilis, gonorrhea, or chlamydia. Venue-based affiliation networks were created to evaluate hookup sites and their association with STD diagnoses. RESULTS: Among 415 MSM, 78% reported meeting a partner online in the last 12 months, and 25% tested positive for at least one STD. Men who met partners online were more likely to be white (67% vs. 54%, P = 0.03) and have more than 10 lifetime partners (87% vs. 58%, P < 0.05). The most commonly used hookup sites included Grindr (78%), Scruff (35%), and Tinder (22%). In the multivariable analysis, only Scruff use was associated with testing positive for an STD (odds ratio, 2.28; 95% confidence interval, 1.09-4.94). However, among men who met partners online, 75% of men diagnosed as having an STD had met a sexual partner on Grindr, including 100% of those who were diagnosed as having gonorrhea. CONCLUSIONS: Use of hookup sites was nearly ubiquitous among MSM undergoing STD screening. Specific hookup sites were significantly associated with STD diagnoses among MSM. Greater efforts are needed to promote STD screening and prevention among MSM who meet partners online.

The Role of Nicotine Dependence in E-Cigarettes' Potential for Smoking Reduction.

Introduction: E-cigarettes (Electronic Nicotine Delivery Systems, or ENDS) are an increasingly popular tobacco product among youth. Some evidence suggests that e-cigarettes may be effective for harm reduction and smoking cessation, although these claims remain controversial. Little is known about how nicotine dependence may contribute to e-cigarettes' effectiveness in reducing or quitting conventional smoking. Methods: A cohort of young adults were surveyed over 4 years (approximately ages 19-23). Varying-coefficient models (VCMs) were used to examine the relationship between e-cigarette use and conventional smoking frequency, and how this relationship varies across users with different nicotine dependence levels. Results: Lifetime, but not recent, e-cigarette use was associated with less frequent concurrent smoking of conventional cigarettes among those with high levels of nicotine dependence. However, nondependent e-cigarette users smoked conventional cigarettes slightly more frequently than those who had never used e-cigarettes. Nearly half of ever e-cigarette users reported using them to quit smoking at the last measurement wave. For those who used e-cigarettes in a cessation attempt, the frequency of e-cigarette use was not associated with reductions in future conventional smoking frequency. Conclusions: These findings offer possible support that e-cigarettes may act as a smoking reduction method among highly nicotine-dependent young adult cigarette smokers. However, the opposite was found in non-dependent smokers, suggesting that e-cigarette use should be discouraged among novice tobacco users. Additionally, although a substantial proportion of young adults used e-cigarettes to help them quit smoking, these self-initiated quit attempts with e-cigarettes were not associated with future smoking reduction or cessation. Implications: This study offers potential support for e-cigarettes as a smoking reduction tool among highly nicotine-dependent young adult conventional smokers, although the extent and nature of this remains unclear. The use of e-cigarettes as a quit aid was not associated with reductions in conventional smoking, consistent with most other quit aids in this sample except for nicotine replacement therapy, which was only effective for the most dependent smokers. Notably, these findings highlight the necessity of accounting for smokers' nicotine dependence levels when examining tobacco use patterns.

Integrative Data Analysis of Gender and Ethnic Measurement Invariance in Nicotine Dependence Symptoms.

Little research has evaluated whether conflicting evidence for gender and racial/ethnic differences in nicotine dependence (ND) may be attributed to differences in psychometric properties of ND symptoms, particularly for young Hispanic smokers. Inadequate racial/ethnic diversity and limited smoking exposure variability has hampered research in young smokers. We used integrative data analysis (IDA) to pool DSM-IV ND symptom data for current smokers aged 12-25 (N = 20,328) from three nationally representative surveys (1999, 2000 National Surveys on Drug Use and Health (NSDUH) and Wave 1 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Moderated nonlinear factor analysis (MNLFA) tested symptom measurement invariance in the pooled sample containing greater ethnic and smoking exposure variability. There was study noninvariance for most symptoms. NESARC participants were more likely to report tolerance, using larger amounts or for longer periods, inability to cut down/quit, and more time spent smoking at higher levels of ND severity, but reported emotional/physical health problems at lower ND severity. Four symptoms showed gender or race/ethnicity noninvariance, but observed differences were small. An ND severity factor score adjusting for symptom noninvariance related to study membership, gender, and race/ethnicity did not differ substantively from traditional DSM-IV diagnosis and number of endorsed symptoms in estimated gender and race/ethnicity differences in ND. Results were consistent with studies finding minimal gender and racial/ethnic differences in ND, and suggest that symptom noninvariance is not a major contributor to observed differences. Results support IDA as a potentially promising approach for testing novel ND hypotheses not possible in independent studies.

Individual and Partner-Level Factors Associated with Condom Non-Use Among African American STI Clinic Attendees in the Deep South: An Event-Level Analysis.

The US HIV/AIDS epidemic is concentrated in the Deep South, yet factors contributing to HIV transmission are not fully understood. We examined relationships between substance use, sexual partnership characteristics, and condom non-use in an African American sample of STI clinic attendees in Jackson, Mississippi. We assessed condom non-use at last intercourse with up to three recent sexual partners reported by participants between January and June 2011. Participant- and partner-level correlates of condom non-use were examined using generalized estimating equations. The 1295 participants reported 2880 intercourse events, of which 1490 (51.7 %) involved condom non-use. Older age, lower educational attainment, reporting financial or material dependence on a sex partner, sex with a primary partner, and higher frequency of sex were associated with increased odds of condomless sex. HIV prevention efforts in the South should address underlying socioeconomic disparities and structural determinants that result in partner dependency and sexual risk behavior.

Early-Emerging Nicotine Dependence Has Lasting and Time-Varying Effects on Adolescent Smoking Behavior.

Novice and light adolescent smokers can develop symptoms of nicotine dependence, which predicts smoking behavior several years into the future. However, little is known about how the association between these early - emerging symptoms and later smoker behaviors may change across time from early adolescence into young adulthood. Data were drawn from a 7-year longitudinal study of experimental (<100 cigarettes/lifetime; N = 594) and light (100+ cigarettes/lifetime, but ≤5 cigarettes/day; N = 152) adolescent smokers. Time-varying effect models were used to examine the relationship between baseline nicotine dependence (assessed at age 15 ± 2 years) and future smoking frequency through age 24, after controlling for concurrent smoking heaviness. Baseline smoking status, race, and sex were examined as potential moderators of this relationship. Nicotine dependence symptoms assessed at approximately age 15 significantly predicted smoking frequency through age 24, over and above concurrent smoking heaviness, though it showed declining trends at older ages. Predictive validity was weaker among experimenters at young ages (<16), but stronger at older ages (20-23), relative to light smokers. Additionally, nicotine dependence was a stronger predictor of smoking frequency for white smokers around baseline (ages 14.5-16), relative to nonwhite smokers. Nicotine dependence assessed in mid-adolescence predicts smoking frequency well into early adulthood, over and above concurrent smoking heaviness, especially among novice smokers and nonwhite smokers. Early-emerging nicotine dependence is a promising marker for screening and interventions aimed at preventing smoking progression.

Results from a Geographically Focused, Community-Based HCV Screening, Linkage-to-Care and Patient Navigation Program.

BACKGROUND: Many of the five million Americans chronically infected with hepatitis C (HCV) are unaware of their infection and are not in care. OBJECTIVE: We implemented and evaluated HCV screening and linkage-to-care interventions in a community setting. DESIGN: We developed a comprehensive, community-based HCV screening and linkage-to-care program in a medically underserved neighborhood with high rates of HCV infection in Philadelphia, Pennsylvania. We provided patient navigation services to enroll uninsured patients in insurance programs, facilitate referrals from primary care physicians and link patients to an HCV infectious disease specialist with intention to treat and cure. PATIENTS: Philadelphia residents were recruited through street outreach. MAIN MEASURES: We measured anti-HCV seroprevalence and diagnosis, linkage and retention in care outcomes for chronically infected patients. KEY RESULTS: We screened 1,301 participants for HCV; anti-HCV seroprevalence was 3.9 % and 2.8% of all patients were chronically infected. Half of chronically infected patients were newly diagnosed; the remaining patients were aware of infection but not in care. We provided confirmatory RNA testing and results, assisted patients with attaining insurance and linked most chronically infected patients to a primary care provider. The biggest barrier to retaining patients in care was obtaining referrals for subspecialty providers; however, we obtained referrals for 64% of chronically infected participants and have retained most in subspecialty HCV care. Several have commenced treatment. CONCLUSIONS: Non-clinical screening programs with patient navigator services are an effective means to diagnose, link, retain and re-engage patients in HCV care. Eliminating referral requirements for subspecialty care might further enhance retention in care for patients chronically infected with HCV.

Exploring alternate processes contributing to the association between maternal smoking and the smoking behavior among young adult offspring.

INTRODUCTION: Maternal smoking during pregnancy (MSP) is a known risk factor for regular smoking in young adulthood and may pose a risk independently of mother's lifetime smoking. The processes through which MSP exerts this influence are unknown but may occur through greater smoking quantity and frequency following initiation early in adolescence or increased sensitivity to nicotine dependence (ND) at low levels of smoking. METHODS: This study used path analysis to investigate adolescent smoking quantity, smoking frequency, and ND as potential simultaneous mediating pathways through which MSP and mother's lifetime smoking (whether she has ever smoked) increase the risk of smoking in young adulthood among experimenters (at baseline, <100 cigarettes/lifetime) and current smokers (>100 cigarettes/lifetime). RESULTS: For experimenters, MSP was directly associated with more frequent young adult smoking and was not mediated by adolescent smoking behavior or ND. Independently of MSP, the effect of mother's lifetime smoking was fully mediated through frequent smoking and was heightened ND during adolescence. Controlling for MSP eliminated a previously observed direct association between mother's lifetime smoking and future smoking among experimenters. For current smokers, only prior smoking behavior was associated with future smoking frequency. CONCLUSIONS: These results seem to rule out sensitivity to ND and increased smoking behavior as contributing pathways of MSP. Further, the impact of MSP on young adult smoking extends beyond that of having an ever-smoking mother. Future work should test other possible mediators; for example, MSP-related epigenetic changes or gene variants influencing the brain's nicotine response.

The natural course of nicotine dependence symptoms among adolescent smokers.

INTRODUCTION: Few studies have investigated the natural course of nicotine dependence prospectively from the earliest experiences with smoking. METHODS: Drawing on a cohort of 9th- and 10th-grade adolescents followed over 48 months, survival analyses were conducted to evaluate the cumulative probability, following smoking initiation, for the development of nicotine dependence symptoms. RESULTS: Although each nicotine dependence symptom was significantly more prevalent among adolescents who had smoked more than 100 cigarettes by the end of the follow-up assessment, 20% of adolescents smoking fewer than 100 cigarettes reported experiencing "smoking to relieve restlessness and irritability" and "smoking a lot more now to be satisfied compared to when first smoked." Nicotine dependence symptoms were also reported before reaching 100 cigarettes for a substantial number of adolescents (between 9.4% and 58.8% for individual symptoms). Endorsement of nicotine dependence symptoms prospectively predicted past-week smoking (odds ratios [ORs] between 3.18 and 14.62 for significant symptoms) and past-month daily smoking (significant symptoms' ORs between 3.52 and 10.68) at the 48-month assessment even when controlling for amount of previous smoking. CONCLUSIONS: The present study adds to the growing body of literature on the natural course of nicotine dependence from earliest experiences with smoking by showing that symptoms of nicotine dependence may develop soon after initiation and/or at low levels of smoking. Our findings suggest that novice adolescent smokers should not be neglected in smoking cessation intervention and that screening and effective intervention for early emerging symptoms among adolescent smokers may be an important target in preventing chronic smoking.

Estimating causal and time-varying effects of maternal smoking on youth smoking.

INTRODUCTION: Maternal smoking is a well-known risk factor for youth smoking, yet whether this relationship is causal remains unresolved. This study utilizes propensity score methods for causal inference to robustly account for shared risk factors between maternal and offspring smoking. METHODS: An 8-year longitudinal cohort of 900 adolescents in the Chicago area were followed starting from approximately age 15.6. The effects of maternal lifetime smoking (MLS) and prenatal tobacco exposure (PTE) (among participants reporting MLS) on offspring's past 30-day smoking, daily smoking status and smoking frequency were examined using logistic regression and Poisson regression after nearest-neighbor propensity matching. Age dependency of this relationship was then examined across the age range of 15-25 using time-varying effect modeling. RESULTS: Propensity matching yielded 438 and 132 pairs for MLS and PTE study samples, respectively. MLS demonstrated significant associations with past 30-day smoking (RR 1.09; 95% CI 1.04-1.14), daily smoking (RR 1.08; 95% CI 1.05-1.12), and smoking frequency of offspring (RR 1.32; 95% CI 1.15-1.52), with stable effects across age. Among participants reporting MLS, having PTE showed significant additional effects on daily smoking (RR 1.09; 95% CI 1.02-1.17) and age-dependency that showed significance during young adulthood but not adolescence. CONCLUSION: The relationship between maternal and offspring smoking was not fully accounted for by shared risk factors, suggesting possible causation with PTE having a delayed effect across age. Targeted prevention efforts should be made on maternal smoking-exposed adolescents to mitigate their risks of developing heavy smoking habits in adulthood.

DSM-IV nicotine dependence symptom characteristics for recent-onset smokers.

INTRODUCTION: This study evaluated how well DSM-IV nicotine dependence symptoms measure an underlying dependence construct for recent-onset daily and nondaily smokers. METHODS: Based on a nationally representative sample of 2,758 recent-onset adolescent smokers from the National Surveys on Drug Use and Health, we used multiple group item response theory analysis to assess 7 symptoms representing DSM-IV diagnostic features of nicotine dependence. RESULTS: After controlling for age, gender, current smoking quantity, and length of smoking exposure, all 7 DSM-IV symptoms were invariant across nondaily and daily smokers and discriminated well among levels of the nicotine dependence construct. Symptoms most likely to be endorsed at lower levels of the dependence construct included spending more time getting, using, or getting over the effects of smoking and wanting or trying to stop or cut down. Symptoms most likely to be endorsed only at higher levels of the construct included giving up important activities and emotional/psychological and health problems related to smoking. DSM-IV symptoms were most precise for moderately high levels of the dependence construct and less precise for lower levels for both nondaily and daily smokers. DISCUSSION: DSM-IV nicotine dependence symptoms appear to have desirable psychometric properties for measuring a nicotine dependence construct among recent-onset adolescent smokers at both daily and nondaily levels, providing justification for the use of these symptoms in a measure that aims to evaluate the full continuum of nicotine dependence severity in this population.

Use of noninvasive positive pressure ventilation in patients with severe obesity undergoing esophagogastroduodenoscopy: a randomized controlled trial.

BACKGROUND: Patients with severe obesity being considered for bariatric surgery often undergo preoperative esophagogastroduodenoscopy (EGD). Severe obesity is a risk factor for oxygen desaturation events during EGD. The use of noninvasive positive pressure ventilation (NIPPV) to reduce desaturation events during EGD among patients with severe obesity has not been studied. OBJECTIVE: To evaluate the use of NIPPV among patients with severe obesity undergoing EGD. SETTING: Community hospital endoscopy suite. METHODS: A randomized controlled trial evaluated the use of NIPPV in patients with severe obesity undergoing EGD. Patients were randomized into treatment (NIPPV) and control (nasal cannula, NIPPV for rescue) groups. Primary endpoints were oxygen desaturation events ≤94% and oxygen desaturation events <90% requiring intervention. A secondary endpoint was the use of NIPPV as a rescue maneuver. RESULTS: Fifty-six patients with a body mass index of 40 to 60 were randomized (n = 28 treatment and n = 28 control). A statistically significant difference was noted between the groups for desaturation events ≤94% (14.3% of treatment and 57.1% of control groups, P = .002). There was also a statistically significant difference in the risk of a desaturation event <90% requiring intervention (3.5% of treatment and 28.6% of control groups, P = .025). All patients in the control group who developed desaturation events requiring intervention were rescued with NIPPV. CONCLUSIONS: This study demonstrated the successful use of NIPPV as an adjunct to decrease the incidence of desaturation events in patients with severe obesity undergoing EGD.

Trazodone for sleep disturbance after alcohol detoxification: a double-blind, placebo-controlled trial.

BACKGROUND: Trazodone is a commonly prescribed off-label for sleep disturbance in alcohol-dependent patients, but its safety and efficacy for this indication is unknown. METHODS: We conducted a randomized, double-blind, placebo-control trial of low-dose trazodone (50 to 150 mg at bedtime) for 12 weeks among 173 alcohol detoxification patients who reported current sleep disturbance on a validated measure of sleep quality or during prior periods of abstinence. Primary outcomes were the proportion of days abstinent and drinks per drinking day over 6-months; sleep quality was also assessed. RESULTS: Urn randomization balanced baseline features among the 88 subjects who received trazodone and 85 who received placebo. The trazodone group experienced less improvement in the proportion of days abstinent during administration of study medication (mean change between baseline and 3 months: -0.12; 95% CI: -0.15 to -0.09), and an increase in the number of drinks per drinking day on cessation of the study medication (mean change between baseline and 6 months, 4.6; 95% CI: 2.1 to 7.1). Trazodone was associated with improved sleep quality during its administration (mean change on the Pittsburgh Sleep Quality Index between baseline and 3 months: -3.02; 95% CI: -3.38 to -2.67), but after it was stopped sleep quality equalized with placebo. CONCLUSIONS: Trazodone, despite a short-term benefit on sleep quality, might impede improvements in alcohol consumption in the postdetoxification period and lead to increased drinking when stopped. Until further studies have established benefits and safety, routine initiation of trazodone for sleep disturbance cannot be recommended with confidence during the period after detoxification from alcoholism.

Trajectories of smoking from adolescence to early adulthood and their psychosocial risk factors.

OBJECTIVE: To explore patterns of persistence and change in smoking behavior as well as risk factors associated with the developmental course of smoking from age 13 to 25. DESIGN: Data from the public use sample of the National Longitudinal Study of Adolescent Health (N = 5,789) were analyzed using semiparametric group-based modeling. MAIN OUTCOME MEASURES: Smoking quantity-frequency in the past 30 days. RESULTS: Six distinct smoking trajectories were identified: nonsmokers, experimenters, stable light smokers, quitters, late escalators, and stable high smokers. Baseline risk factors that were associated with greater likelihood of membership in all of the smoking trajectory groups compared with nonsmokers included alcohol use, deviance, peer smoking, and (with the exception of the late escalators) drug use. Deviance, peer smoking, and alcohol and drug use also distinguished the likelihood of membership among several of the 5 smoking trajectory groups. CONCLUSION: The results add to basic etiologic research on developmental pathways of smoking in adolescence and young adulthood by providing evidence of heterogeneity in smoking behavior and prospectively linking different patterns of risk factors with the probability of trajectory group membership.

Risk and protective factors associated with trajectories of depressed mood from adolescence to early adulthood.

This study used semi-parametric group-based modeling to explore unconditional and conditional trajectories of self-reported depressed mood from ages 12 to 25 years. Drawing on data from the National Longitudinal Study of Adolescent Health (N = 11,559), 4 distinct trajectories were identified: no depressed mood, stable low depressed mood, early high declining depressed mood, and late escalating depressed mood. Baseline risk factors associated with greater likelihood of membership in depressed mood trajectory groups compared with the no depressed mood group included being female, Black or African American, Hispanic or Latino American, or Pacific Islander or Asian American; having lower socioeconomic status; using alcohol, tobacco, or other drugs on a weekly basis; and engaging in delinquent behavior. Baseline protective factors associated with greater likelihood of membership in the no depressed mood group compared with the depressed mood trajectory groups included 2-parent family structure; feeling connected to parents, peers, or school; and self-esteem. With the exception of delinquent behavior, risk and protective factors also distinguished the likelihood of membership among several of the 3 depressed mood groups. The results add to basic etiologic research regarding developmental pathways of depressed mood in adolescence and young adulthood.

Racial/ethnic sexual health disparities among incarcerated women.

Rates of sexually transmitted infections (STIs) in women in U.S. corrections facilities are higher than rates in community samples. Research that combines behavioral correlates of STI with STI history by race/ethnicity has not been done in incarcerated women. The purpose of this study was to compare by race/ethnicity self-reported sexual risk behaviors with self-reported history of STI in an incarcerated sample. An interviewer administered a questionnaire to 428 incarcerated women. Blacks were more likely to report consistent condom use in the three months prior to incarceration (47% vs. 28%, p < 0.05), and Hispanics were less likely to report sex work than were whites (16% vs. 39%, p < 0.05). Whites were more likely than blacks to report having had an unplanned pregnancy (88% vs. 67%, p < 0.05). Despite having lower self-reported risk on several measures, Blacks were more likely to report history of STI (65% vs. 40%, p < 0.05). The correctional setting is an opportune place to better understand and address the complex issue of sexual health disparities.

Evaluating the mutual pathways among electronic cigarette use, conventional smoking and nicotine dependence.

BACKGROUND AND AIMS: The implications of the rapid rise in electronic cigarette (e-cigarette) use remain unknown. We examined mutual associations between e-cigarette use, conventional cigarette use and nicotine dependence over time to (1) test the association between e-cigarette use and later conventional smoking (both direct and via nicotine dependence), (2) test the converse associations and (3) determine the strongest pathways predicting each product's use. DESIGN: Data from four annual waves of a prospective cohort study were analyzed. Path analysis modeled the bidirectional, longitudinal relationships between past-month smoking frequency, past-month e-cigarette frequency and nicotine dependence. SETTING: Chicago area, Illinois, USA. PARTICIPANTS: A total of 1007 young adult smokers and non-smokers (ages 19-23 years). MEASUREMENTS: Frequency of (1) cigarettes and (2) e-cigarettes was the number of days in the past 30 on which the product was used. The Nicotine Dependence Syndrome Scale measured nicotine dependence to cigarettes. FINDINGS: E-cigarette use was not associated significantly with later conventional smoking, either directly (ß = 0.021, P = 0.081) or through nicotine dependence (ß = 0.005, P = 0.693). Conventional smoking was associated positively with later e-cigarette use, both directly (ß = 0.118, P < 0.001) and through nicotine dependence (ß = 0.139, P < 0.001). The strongest predictors of each product's use was prior use of the same product; this pathway was strong for conventional cigarettes (ß = 0.604, P < 0.001) but weak for e-cigarettes (ß = 0.120, P < 0.001). Nicotine dependence moderately strongly predicted later conventional smoking (ß = 0.169, P < 0.001), but was a weak predictor of later e-cigarette use (ß = 0.069, P = 0.039). CONCLUSIONS: Nicotine dependence is not a significant mechanism for e-cigarettes' purported effect on heavier future conventional smoking among young adults. Nicotine dependence may be a mechanism for increases in e-cigarette use among heavier conventional smokers, consistent with e-cigarettes as a smoking reduction tool. Overall, conventional smoking and, to a lesser extent, its resulting nicotine dependence, are the strongest drivers or signals of later cigarette and e-cigarette use.

The role of nicotinic receptor genes (CHRN) in the pathways of prenatal tobacco exposure on smoking behavior among young adult light smokers.

BACKGROUND: Prenatal tobacco exposure (PTE) is associated with more frequent smoking among young, light smokers. Little is known about how nicotinic acetylcholine receptor (CHRN) genes may contribute to this relationship. METHODS: Data were drawn from a longitudinal cohort of young light smokers of European ancestry (N = 511). Three single nucleotide polymorphisms (SNPs) among offspring, rs16969968 and rs6495308 in CHRNA5A3B4 and rs2304297 in CHRNB3A6, were analyzed with respect to whether they 1) predict PTE status; 2) confound the previously-reported effects of PTE on future smoking; 3) have effects on youth smoking frequency that are mediated through PTE; and 4) have effects that are moderated by PTE. RESULTS: rs2304297 and rs6495308 were associated with increased likelihood and severity of PTE, respectively. In a path analysis, rs16969968 directly predicted more frequent smoking in young adulthood (B = 1.50, p = .044); this association was independent of, and not mediated by, PTE. The risk of rs16969968 (IRR = 1.07, p = .015) and the protective effect of rs2304297 (IRR = 0.84, p < .001) on smoking frequency were not moderated by PTE. PTE moderated the effect of rs6495308, such that these alleles were protective against later smoking frequency only among non-exposed youth (IRR = 0.85, p < .001). CONCLUSIONS: The association between offspring CHRNB3A6 and PTE is a novel finding. The risk of rs16969968 on youth smoking is independent and unrelated to that of PTE among young, light smokers. PTE moderates the protective effect of rs6495308 on youth smoking frequency. However, PTE's pathway to youth smoking behavior was not explained by these genetic factors, leaving its mechanism(s) of action unclear.

Marijuana use among young women in a primary care setting.

OBJECTIVE: To evaluate the prevalence of marijuana use among young women, ages 18-24, within a primary care setting. DESIGN: From 2/05 to 12/05, women completed a brief, anonymous self-report screening instrument in two urban primary care clinics for potential participation in a randomized controlled trial of an intervention to reduce marijuana use and sexual risk-taking behavior. During the last few months of recruitment, women who completed the screening instrument were also asked to provide a urine sample to test for the presence of marijuana and other drugs. RESULTS: Of the 607 women who completed the screening instrument, 38.6% reported lifetime marijuana use, 8.4% used marijuana at least monthly, and 1.7% reported using marijuana daily. Within this ethnically diverse sample (45% Hispanic), women who used marijuana at least monthly were more likely to smoke cigarettes (OR = 2.03, 95% CI = 1.04, 3.96), binge drink at least once a month (OR = 2.66, 95% CI = 1.34, 5.28), and to have ever used other drugs (OR = 2.91, 95% CI = 1.31, 6.45). Of the 67 urine samples provided, 60 (89.6%) were concordant with self-reported use, but six of the seven discordant samples were positive despite negative self-report. CONCLUSIONS: The prevalence of marijuana use and binge drinking in this ethnically diverse sample of young, female primary care patients was lower than rates reported in national surveys. Providers should consider marijuana use as a part of a process that addresses more prevalent high-risk behaviors, bearing in mind that these behaviors may be underreported during routine screening.