Bcl-6 directly represses the gene program of the glycolysis pathway.

Despite the increasing knowledge of the molecular events that induce the glycolysis pathway in effector T cells, very little is known about the transcriptional mechanisms that dampen the glycolysis program in quiescent cell populations such as memory T cells. Here we found that the transcription factor Bcl-6 directly repressed genes encoding molecules involved in the glycolysis pathway, including Slc2a1, Slc2a3, Pkm and Hk2, in type 1 helper T cells (TH1 cells) exposed to low concentrations of interleukin 2 (IL-2). Thus, Bcl-6 had a role opposing the IL-2-sensitive glycolytic transcriptional program that the transcription factors c-Myc and HIF-1α promote in effector T cells. Additionally, the TH1 lineage-specifying factor T-bet functionally antagonized the Bcl-6-dependent repression of genes encoding molecules in the glycolysis pathway, which links the molecular balance of these two factors to regulation of the metabolic gene program.

Analysis of human rotaviruses from a single location over an 18-year time span suggests that protein coadaption influences gene constellations.

UNLABELLED: Rotaviruses (RVs) are 11-segmented, double-stranded RNA viruses that cause severe gastroenteritis in children. In addition to an error-prone genome replication mechanism, RVs can increase their genetic diversity by reassorting genes during host coinfection. Such exchanges allow RVs to acquire advantageous genes and adapt in the face of selective pressures. However, reassortment may also impose fitness costs if it unlinks genes/proteins that have accumulated compensatory, coadaptive mutations and that operate best when kept together. To better understand human RV evolutionary dynamics, we analyzed the genome sequences of 135 strains (genotype G1/G3/G4-P[8]-I1-C1-R1-A1-N1-T1-E1-H1) that were collected at a single location in Washington, DC, during the years 1974 to 1991. Intragenotypic phylogenetic trees were constructed for each viral gene using the nucleotide sequences, thereby defining novel allele level gene constellations (GCs) and illuminating putative reassortment events. The results showed that RVs with distinct GCs cocirculated during the vast majority of the collection years and that some of these GCs persisted in the community unchanged by reassortment. To investigate the influence of protein coadaptation on GC maintenance, we performed a mutual information-based analysis of the concatenated amino acid sequences and identified an extensive covariance network. Unexpectedly, amino acid covariation was highest between VP4 and VP2, which are structural components of the RV virion that are not thought to directly interact. These results suggest that GCs may be influenced by the selective constraints placed on functionally coadapted, albeit noninteracting, viral proteins. This work raises important questions about mutation-reassortment interplay and its impact on human RV evolution. IMPORTANCE: Rotaviruses are devastating human pathogens that cause severe diarrhea and kill >450,000 children each year. The virus can evolve by accumulating mutations and by acquiring new genes from other strains via a process called reassortment. However, little is known about the relationship between mutation accumulation and gene reassortment for rotaviruses and how it impacts viral evolution. In this study, we analyzed the genome sequences of human strains found in clinical fecal specimens that were collected at a single hospital over an 18-year time span. We found that many rotaviruses did not reassort their genes but instead maintained them as specific sets (i.e., constellations). By analyzing the encoded proteins, we discovered concurrent amino acid changes among them, which suggests that they are functionally coadapted to operate best when kept together. This study increases our understanding of how rotaviruses evolve over time in the human population.

Effectiveness of telephone-based follow-up support delivered in combination with a multi-component smoking cessation intervention in family practice: a cluster-randomized trial.

OBJECTIVE: To determine whether telephone-based smoking cessation follow-up counseling (FC), when delivered as part of a multi-component intervention program is associated with increased rates of follow-up support and smoking abstinence. METHODS: A cluster randomized controlled-trial was conducted within family medicine practices in Ontario, Canada. Consecutive adult patients who smoked were enrolled at two time points, the baseline period (2009) and the post-intervention period (2009-2011). Smoking abstinence was determined by telephone interview 4 months following enrollment. Both groups implemented a multi-component intervention program. Practices randomized to the FC group could also refer patients to a follow-up support program which involved 5 telephone contacts over a 2-month period. RESULTS: Eight practices, 130 providers, and 928 eligible patients participated in the study. No statistically significant difference in 7-day point-prevalence abstinence was observed between intervention groups. There was a significant increase in referral to follow-up in both intervention groups. Significantly higher rates of smoking abstinence [25.7% vs. 11.3%; adjusted OR 3.1 (95% CI: 1.1, 8.6), p<0.05] were documented among the twenty-nine percent of FC participants who were referred to the follow-up support program compared to the MC group. CONCLUSION: Access to external follow-up support did not increase rates at which follow-up support was delivered.

Transitions in smoking status over time in a population-based panel study of smokers.

INTRODUCTION: Few studies have examined the transitions of smokers in the general population through multiple periods of daily, occasional smoking, or abstinence over time. Transitions from daily to occasional smoking are particularly of interest as these may be steps toward cessation. METHODS: The Ontario Tobacco Survey panel study followed 4,355 baseline smokers, semiannually for up to 3 years. Probabilities of all possible changes in smoking status more than 6 months were estimated using 13,000 repeated measures observations generated from sets of 3 consecutive interviews (n = 9,932 daily smokers, 1,245 occasion smokers, and 1,823 abstinent for at least 30 days, at Time 1). RESULTS: For initial daily smokers, an estimated 83% remained daily smokers more than 2 follow-ups. The majority of those who had been abstinent for 30 days at 1 interview, were also former smokers at the following interview. In contrast, occasional smoking status was unstable and future smoking status was dependent upon smoking history and subjective dependence. Among daily smokers who became occasional smokers 6 months later, an estimated 20% became a former smoker, at the next interview, but 50% returned to daily smoking. Daily, turned occasional smokers who rebounded back to daily smoking were more likely to describe themselves as addicted at Time 1. Continuing occasional smokers were somewhat less likely to intend to quit, or have tried, despite considering themselves less addicted. CONCLUSIONS: Reducing to occasional smoking can be a stepping stone toward cessation but entails a greater risk of return to daily smoking, compared with complete abstinence.

Are occasional smokers a heterogeneous group? An exploratory study.

BACKGROUND: Occasional smokers represent an important segment of all smokers and have been described to be a heterogeneous group in terms of past experience and likelihood of maintaining nondaily smoking behavior. METHODS: In the prospective Ontario Tobacco Survey, 408 occasional smokers were followed for a year. Characteristics of subgroups of occasional smokers, as suggested by previous literature, were studied for personal and smoking behavior group differences. Agglomerative hierarchical clustering was also used to empirically identify subgroups of occasional smokers using average linkage. Smoking status at 1-year follow-up was examined overall and by the identified subgroups to determine if any were useful predictors of persistent status as nondaily smoking and likelihood of smoking cessation. RESULTS: Significant differences were seen among the subgroups of occasional smokers suggested in previous studies including the number of quit attempts, setting a firm quit date, and whether or not participants cared others knew they smoked in descriptive analyses. Exploratory cluster analysis suggested 4 clusters of occasional smokers based on differences in age, perceived addiction, and history of daily smoking. Subgroups based on participants' history of smoking, self-reported addiction level, and empirically identified cluster subgroups resulted in significant differences of smoking status at 1-year follow-up. CONCLUSIONS: This study suggests that occasional smokers may be a heterogeneous group with different subgroups characterized by age, accumulated smoking experience and smoking pattern, as well as factors associated with the likelihood of quitting altogether, over time, and perceived addiction.

Vigorous motor activity in Caenorhabditis elegans requires efficient clearance of dopamine mediated by synaptic localization of the dopamine transporter DAT-1.

The catecholamine dopamine (DA) functions as a powerful modulatory neurotransmitter in both invertebrates and vertebrates. As in man, DA neurons in the nematode Caenorhabditis elegans express a cocaine-sensitive transporter (DAT-1), presumably to regulate synaptic DA signaling and limit DA spillover to extrasynaptic sites, although evidence supporting this is currently lacking. In this report, we describe and validate a novel and readily quantifiable phenotype, swimming-induced paralysis (SWIP) that emerges in DAT-1-deficient nematodes when animals exert maximal physical activity in water. We verify the dependence of SWIP on DA biosynthesis, vesicular packaging, synaptic release, and on the DA receptor DOP-3. Using DAT-1 specific antibodies and GFP::DAT-1 fusions, we demonstrate a synaptic enrichment of DAT-1 that is achieved independently of synaptic targeting of the vesicular monoamine transporter (VMAT). Importantly, dat-1 deletions and point mutations that disrupt DA uptake in cultured C. elegans neurons and/or impact DAT-1 synaptic localization in vivo generate SWIP. SWIP assays, along with in vivo imaging of wild-type and mutant GFP::DAT-1 fusions identify a distal COOH terminal segment of the transporter as essential for efficient somatic export, synaptic localization and in vivo DA clearance. Our studies provide the first description of behavioral perturbations arising from altered trafficking of DATs in vivo in any organism and support a model whereby endogenous DA actions in C. elegans are tightly regulated by synaptic DAT-1.

Prevalence of cigarette smoking among young adults in Pakistan.

OBJECTIVE: To obtain information about the prevalence of cigarette smoking among a selected sample of university students in Karachi and build our understanding of the determinants of smoking with respect to family smoking, smoking in the home, smoke-free public places, and quit smoking cessation programmes. METHODS: Data were collected as a part of a pilot project initiated by Jinnah University Karachi. Participants were 629 university students (432 males and 197 females) aged 18-25 years from ten universities in Karachi. Descriptive statistics and Logistic regression analyses were used to determine the results and conclusions. RESULTS: Thirty-nine per cent of students had smoked a whole cigarette in their life time, whereas 25% had smoked 100 or more cigarettes in their lifetime. Overall, 23% of students (31% male and 6% female) were classified as a current smoker and their mean age and standard deviation of smoking initiation was 17 +/- 2.7 years (17 +/- 2.6) for males and 16 +/- 2.9 females. Sixty-three percent of smokers reported that public places should be smoke-free. Logistic regression analyses adjusted by age and gender suggested that parental and sibling influence and number of close friends and individuals who smoke at home were highly predictive of being a smoker. CONCLUSION: Findings from this study suggest that student were generally open to smoking cessation treatment and no-smoking restrictions.

The Heaviness of Smoking Index as a predictor of smoking cessation in Canada.

Nicotine addiction is believed to be a major impediment for many people in quitting smoking, but measures of nicotine dependence such as the Heaviness of Smoking Index (HSI) have had mixed success in predicting cessation. Using the National Population Health Survey, the relationship between HSI at baseline in cycle 2 (1996-1997) and successful smoking cessation at cycle 3 (1998-1999) and cycle 4 (2000-2001) was examined in 2938 Canadian adult smokers. A logistic regression model was developed for HSI as a predictor of smoking cessation, and then tested for interaction and confounding. The odds ratio of not smoking in cycle 3 was 2.08 (95% CI: 1.51, 2.86; p<0.001) for low HSI (<2) compared to medium HSI. When the period of follow-up was extended, individuals with both high (>4) HSI scores (OR 2.16; 95% CI: 1.11, 4.21; p=0.02) and low scores (OR 2.22; 95% CI: 1.41, 3.49) had higher odds of not smoking at both cycle 3 and cycle 4 than those with medium HSI scores. The likelihood of reporting cessation was higher than expected in the Canadian population among highly dependent smokers, particularly among older smokers, those with middle or greater income adequacy, and those with no intention to quit smoking. There were no substantial changes to the results when those lost-to-follow-up were treated as continuing smokers. These findings indicate that nicotine dependence is only one factor in succeeding at a quit attempt. Individual and population strategies for smoking cessation may need to consider other influences such as cognitive, affective and environmental factors.

A practical, cost-effective method for recruiting people into healthy eating behavior programs.

INTRODUCTION: The population impact of programs designed to develop healthy eating behaviors is limited by the number of people who use them. Most public health providers and researchers rely on purchased mass media, which can be expensive, on public service announcements, or clinic-based recruitment, which can have limited reach. Few studies offer assistance for selecting high-outreach and low-cost strategies to promote healthy eating programs. The purpose of this study was 1) to determine whether classified newspaper advertising is an effective and efficient method of recruiting participants into a healthy eating program and 2) to determine whether segmenting messages by transtheoretical stage of change would help engage individuals at all levels of motivation to change their eating behavior. METHODS: For 5 days in 1997, three advertisements corresponding to different stages of change were placed in a Canadian newspaper with a daily circulation of 75,000. RESULTS: There were 282 eligible people who responded to newspaper advertisements, and the cost was Can $1.11 (U.S. $0.72) per recruit. This cost compares favorably with the cost efficiency of mass media, direct mail, and other common promotional methods. Message type was correlated with respondent's stage of change, and this correlation suggested that attempts to send different messages to different audience segments were successful. CONCLUSION: Classified advertisements appear to be a highly cost-efficient method for recruiting a diverse range of participants into healthy eating programs and research about healthy eating.

Doctors' views of clinical practice guidelines: a qualitative exploration using innovation theory.

RATIONALE, AIMS AND OBJECTIVES: The authors undertook this qualitative study as part of a larger evaluation of the effect of eight clinical practice guidelines issued by an arm's-length government agency in a Canadian province. Using Orlandi and colleagues' version of the Rogers diffusion of innovation model as a framework, the authors mapped doctors' views on implementation of clinical practice guidelines. METHODS: In semi-structured interviews with 45 representative doctors, the authors elicited doctors' framework of meaning for behaviour change in general and for clinical practice guideline uptake in particular. These were then compared with the adapted Orlandi/Rogers diffusion of innovation model to confirm, amend or challenge that model. RESULTS: Doctors identified the following influences on changes to their clinical practice and on clinical practice guideline uptake, within a five-step innovation model: 1 innovation: evidence change is required, perceived need for change; 2 communication: awareness of innovation; 3 adoption: evidence of improved outcomes without increased patient risk, opinion leader support, consistency with current trends; 4 implementation: patient and family acceptability; and 5 maintenance: system support, patient and family support, observed improved patient outcomes without increased risk. CONCLUSIONS: Innovation for doctors is a complex decision process rather than a single decision point. Change occurs in the context of professional networks and patient and family support and demand.

From evidence-based practice making to practice-based evidence making: creating communities of (research) and practice.

Models of research translation frequently emphasize independent roles for research producers and intended users. This article describes a novel approach for enhancing exchange between researchers and practitioners. The framework is based on Wenger's notion of Communities of Practice (CoP) where knowledge is regarded as a social enterprise at the center of member interactions. Research-based practices and policies emerge when research producers and users mutually engage one another about specific health promotion problems through negotiation and by creating and sharing technical standards and other resources. CoPs are more than loose networks or task-oriented teams. They aim to create both social and intellectual capital through mutual negotiation, reciprocity, trust, and cohesion. A Consortium of Quitline Operators across North America and a Canadian project to enhance research capacity for tobacco control research serve as examples of how the model has been successfully operationalized.

Are the recommended taxonomies for the stages of youth smoking onset consistent with youth's perceptions of their smoking status?

BACKGROUND: To examine if the recommended taxonomies for the stages of youth smoking onset are aligned with the beliefs of smoking youth. METHODS: The SHAPES Tobacco Module was administered to 23,047 students (grades 9 to 13) in a convenience sample of 29 secondary schools during the 2000-2001 school year in the province of Ontario, Canada. Cross-tabs were used to compare a student's self-perceived smoking status to their smoking status as determined with the currently recommended stage taxonomies for smoking behaviour. RESULTS: The majority of students classified as regular smokers (52.4%) and experimental smokers (98.9%) did not actually consider themselves to be smokers. Self-reported smoking status appeared to be relatively consistent for the never smoker and established smoker categories. CONCLUSIONS: Additional research is required to develop stage taxonomies that are aligned with the self-perceptions of non-established youth smokers.

IL-2, IL-7, and IL-15: Multistage regulators of CD4(+) T helper cell differentiation.

Cytokines represent a class of environmental factors that are critical drivers of immune cell development. Cytokines of the common gamma-chain family, including interleukin (IL)-2, IL-7, and IL-15, have been the subject of intense experimental scrutiny and have well-defined roles as regulators of diverse immune cell types including CD4(+) T helper cells. Because of their pleiotropic effects on T-cell development and function, researchers and clinicians have attempted to harness the capabilities of these cytokines for therapeutic benefit. In this review, we summarize the recent progress in our understanding of the molecular mechanisms underlying the effects of these cytokines on CD4(+) T cell development and briefly discuss how these immunomodulatory cytokines are being used in efforts to treat human disease.

IL-7 signalling represses Bcl-6 and the TFH gene program.

The transcriptional repressor Bcl-6 is linked to the development of both CD4(+) T follicular helper (TFH) and central memory T (TCM) cells. Here, we demonstrate that in response to decreased IL-2 signalling, T helper 1 (TH1) cells upregulate Bcl-6 and co-initiate TFH- and TCM-like gene programs, including expression of the cytokine receptors IL-6Rα and IL-7R. Exposure of this potentially bi-potent cell population to IL-6 favours the TFH gene program, whereas IL-7 signalling represses TFH-associated genes including Bcl6 and Cxcr5, but not the TCM-related genes Klf2 and Sell. Mechanistically, IL-7-dependent activation of STAT5 contributes to Bcl-6 repression. Importantly, antigen-specific IL-6Rα(+)IL-7R(+) CD4(+) T cells emerge from the effector population at late time points post influenza infection. These data support a novel role for IL-7 in the repression of the TFH gene program and evoke a divergent regulatory mechanism by which post-effector TH1 cells may contribute to long-term cell-mediated and humoral immunity.

What smoking cessation approaches will young smokers use?

The purpose of this study was to examine the attitudes of youth smokers toward nine common smoking cessation approaches. Attitudes were examined among 3660 youth smokers who intended to quit smoking. The majority of youth smokers report that they would never use the smoking cessation approaches that are commonly recommended for youth populations. The approaches that were appealing to youth are quitting on their own and using the advice of friends. Future initiatives need to more effectively communicate to youth the benefits of existing cessation approaches, make existing interventions more appealing, or develop new approaches that address youth needs.

An examination of the relationship between municipal smoke-free bylaw strength and the odds of being a former smoker.

OBJECTIVE: The purpose of this study was to examine the relationship between municipal no-smoking bylaw strength and the odds of being a former smoker. METHODS: Data from Statistics Canada's Canadian Community Health Survey (Cycle 1.1, 2001) and a validated bylaw scoring scheme (2001) were linked and analyzed to determine whether the odds of being a former smoker were related to the strength of no-smoking bylaws in municipalities that had been matched for potentially confounding factors. The sample consisted of ever smokers (current and former smokers) from Ontario municipalities that did not have a no-smoking bylaw, or had a fully implemented no-smoking bylaw before September 2000. Data were analyzed using a Mantel-Haenszel Chi-square test and a logistic regression. RESULTS: The results from the Mantel-Haenszel (OR = 0.94, 95% CI 0.80-1.12) and logistic regression analyses (OR = 0.95, 95% CI 0.82-1.11) did not find support for the hypothesis that living in a municipality with a strong no-smoking bylaw would increase the odds of being a former smoker. DISCUSSION: Findings were inconsistent with previous studies that have found no-smoking restrictions in homes, workplaces and public places increase the odds that smokers attempt and succeed in quitting smoking. However, results from this study must be interpreted with caution because of the cross-sectional design and limited control of potentially important covariates.

A multilevel analysis examining the relationship between social influences for smoking and smoking onset.

OBJECTIVES: To examine how older smoking peers at school and the smoking behavior of friends and family members are related to youth smoking. METHODS: The School Smoking Profile was used to collect data on tobacco use and determinants of tobacco use from 22,091 students from 29 secondary schools in Ontario, Canada. Correlates of occasional and regular smoking were examined using multilevel logistic regression analyses. RESULTS: Students are at increased risk for smoking if they (a) have smoking friends, (b) have smoking family members, and (c) attend a school with a relatively high senior-student smoking rate. CONCLUSION: These findings suggest that prevention programs should target both at-risk schools and at-risk students.

A low-cost, practical method for increasing smokers' interest in smoking cessation programs.

BACKGROUND: Low participation rates reduce the public health impact of smoking cessation programs. Two barriers for improving participation are the cost of media campaigns and the proportion of smokers motivated to quit smoking. The objective of this study was to examine the feasibility of using classified newspaper ads and messages aimed at each stage of change to enhance participation in smoking cessation programs. METHODS: Three classified ads were run concurrently in a local daily newspaper for five consecutive days. The ads were designed to engage smokers in each of Prochaska's five stages of change. Each ad invited smokers or former smokers to call the local health department to participate in a paid focus group to design a new health department program. RESULTS: Calls were received from 181 eligible smokers, including 124 who provided data for the study. Thirty-seven, 34, and 29 percent of smoking respondents were in precontemplation, contemplation and preparation respectively. Half of ex-smokers were in the action stage. Ads cost 174 dollars (Cdn), thus the cost per recruit was less than a dollar. CONCLUSION: Classified ads can recruit smokers from all stages of change. Compared to traditional mass media, classified ads may also be a highly cost-efficient promotional strategy. Results provide justification for further research.

The impact of cigarette warning labels and smoke-free bylaws on smoking cessation: evidence from former smokers.

BACKGROUND: To effectively address the health burden of tobacco use, tobacco control programs must find ways of motivating smokers to quit. The present study examined the extent to which former smokers' motivation to quit was influenced by two tobacco control policies recently introduced in the Waterloo Region: a local smoke-free bylaw and graphic cigarette warning labels. METHODS: A random digit-dial telephone survey was conducted with 191 former smokers in southwestern Ontario, Canada in October 2001. Former smokers who had quit in the previous three years rated the factors that influenced their decision to quit and helped them to remain abstinent. RESULTS: Thirty-six percent of former smokers cited smoke-free policies as a motivation to quit smoking. Former smokers who quit following the introduction of a total smoke-free bylaw were 3.06 (CI95 = 1.02-9.19) times more likely to cite smoking bylaws as a motivation to quit, compared to former smokers who quit prior to the bylaw. A total of 31% participants also reported that cigarette warning labels had motivated them to quit. Former smokers who quit following the introduction of the new graphic warning labels were 2.78 (CI9 = 1.20-5.94) times more likely to cite the warnings as a quitting influence than former smokers who quit prior to their introduction. Finally, 38% of all former smokers surveyed reported that smoke-free policies helped them remain abstinent and 27% reported that warning labels helped them do so. CONCLUSION: More stringent smoke-free and labelling policies were associated with a greater impact upon motivations to quit.