Smoking prevention counseling practices of Montreal general practitioners

BACKGROUND: Primary care physicians are potentially important sources of interventions aimed at preventing youth smoking. Yet recent surveys suggest that physician smoking prevention practices are less than optimal. OBJECTIVES: To document prevention counseling practices and to identify correlates of these activities in a random sample of general practitioners in Montreal, Quebec. METHODS: A cross-sectional mail survey. RESULTS: Of 440 eligible general practitioners (GPs), 337 (77%) completed the questionnaire. General practitioners were more likely to ascertain the smoking status of adolescents (70.9%) than preadolescents (35.7%). Although about half of the GPs offered advice to prevent smoking onset in young adults (48.6%) and adolescents (48.3%), fewer did so for preadolescents (34.4%); only 12.1% advised parents to discuss smoking onset with their children. Correlates of ascertaining smoking status included female sex (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.07-3.41), lower proportion of walk-in patients (OR, 2.73; 95% CI, 1.31-5.80), awareness of the "stage of behavior change" model (OR, 2.17; 95% CI, 1.18-4.04), and higher self-efficacy (OR, 4.12, 95% CI, 2.00-8.69). Correlates of provision of prevention advice included more hours spent in direct patient care (OR, 1.93; 95% CI, 1.13-3.34), favorable beliefs and attitudes (OR, 1.73; 95% CI, 1.06-2.83), and higher self-efficacy (OR, 4.32; 95% CI, 2.25-8.44). CONCLUSIONS: Our results point to the need for renewed efforts to enhance preventive efforts in primary care settings. Intervention programs for GPs should emphasize overcoming unfavorable beliefs and attitudes and low self-efficacy. Future research should evaluate the effect of brief prevention counseling adapted to increasingly busy practices.     

Adenoviral Expression of a Bispecific VHH-Based Neutralizing Agent That Targets Protective Antigen Provides Prophylactic Protection from Anthrax in Mice

Bacillus anthracis, the causative agent of anthrax, secretes three polypeptides, which form the bipartite lethal and edema toxins (LT and ET, respectively). The common component in these toxins, protective antigen (PA), is responsible for binding to cellular receptors and translocating the lethal factor (LF) and edema factor (EF) enzymatic moieties to the cytosol. Antibodies against PA protect against anthrax. We previously isolated toxin-neutralizing variable domains of camelid heavy-chain-only antibodies (VHHs) and demonstrated their in vivo efficacy. In this work, gene therapy with an adenoviral (Ad) vector (Ad/VNA2-PA) (VNA, VHH-based neutralizing agents) promoting the expression of a bispecific VHH-based neutralizing agent (VNA2-PA), consisting of two linked VHHs targeting different PA-neutralizing epitopes, was tested in two inbred mouse strains, BALB/cJ and C57BL/6J, and found to protect mice against anthrax toxin challenge and anthrax spore infection. Two weeks after a single treatment with Ad/VNA2-PA, serum VNA2-PA levels remained above 1 μg/ml, with some as high as 10 mg/ml. The levels were 10- to 100-fold higher and persisted longer in C57BL/6J than in BALB/cJ mice. Mice were challenged with a lethal dose of LT or spores at various times after Ad/VNA2-PA administration. The majority of BALB/cJ mice having serum VNA2-PA levels of >0.1 μg/ml survived LT challenge, and 9 of 10 C57BL/6J mice with serum levels of >1 μg/ml survived spore challenge. Our findings demonstrate the potential for genetic delivery of VNAs as an effective method for providing prophylactic protection from anthrax. We also extend prior findings of mouse strain-based differences in transgene expression and persistence by adenoviral vectors.     

Mothers’ Intentions to Support Children’s Physical Activity Related to Attention and Implicit Agreement with Advertisements

Background

ParticipACTION’s Think Again campaign targeted mothers who think their children are sufficiently active, yet whose children do not achieve recommended amounts of physical activity.

Purpose

This research examined the relationship of mothers’ intentions to support children’s physical activity with explicit believability and implicit agreement with the Think Again campaign message, attention paid to the advertisement, involvement with the issue, concern regarding children’s inactivity, and attitudes.

Method

Participants were mothers from Edmonton, Canada (N?=?102) who viewed one Think Again advertisement then completed a measure of implicit agreement with the campaign message and questionnaires.

Results

The mothers who paid attention to the message and were concerned for their own children were more likely to intend to act on campaign messages. The majority of participants implicitly agreed that children’s physical inactivity was a problem, but there was less agreement that physical inactivity was a problem for their own children.

Conclusion

Participants automatically tended to agree with campaign messages when the focus was on children in general, but there was greater disagreement when asked about participant’s own children. Why most mothers were not in agreement with the reality of how much physical activity their children needs remains to be determined.     

Resolving the composite trait of hypertension into its pharmacogenetic determinants by acute pharmacological modulation of blood pressure regulatory systems

Acute pharmacogenetic analysis was carried out in an intercross F2 population derived from Prague hypertensive-hypertriglyceridemic and Lewis rats. Quantitative trait loci (QTL) mapping was performed for baseline blood pressure (BP) and for BP after blockade of the renin-angiotensin system by losartan, of the sympathetic nervous system (SNS) by pentolinium, and of the nitric oxide system by N(G)-nitro- L-arginine methyl ester. Two significant loci for baseline BP were found on chromosome (Chr) 3 (logarithm of likelihood, LOD, 3.8) and Chr 5 (LOD 3.6), and one suggestive locus on Chr 1 (LOD 2.7). The QTL on Chr 3 persisted after treatment with the three agents while the QTL on Chr 5 and Chr 1 disappeared after pentolinium administration. This suggests independence of the locus on Chr 3 from each acute BP regulatory system examined, whereas the loci on Chr 5 and Chr 1 appeared to be controlled mainly by the SNS. Although not apparent at baseline, a significant locus appeared on Chr 8 (LOD 7.0) after blockade of the SNS, and NO system blockade led to the appearance of a new QTL on Chr 1 (LOD 3.6), indicating the contribution of the inhibited systems to these loci. Pharmacogenetic dissection of the BP trait is a powerful tool to unravel the underlying physiological mechanisms of QTL affecting baseline BP and to identify specific QTL for the response to drugs. This pharmocogenetic approach enabled us to determine the main causative acute BP regulatory systems and should lead to better selection of suitable antihypertensive drugs for individual patients.     

Secular changes in incidence and mortality associated with Staphylococcus aureus bacteraemia in Quebec, Canada, 1991-2005.

In order to examine secular changes in the incidence and mortality associated with Staphylococcus aureus bacteraemia before and after the emergence of methicillin-resistant S. aureus (MRSA), a retrospective cohort study of 815 patients with S. aureus bacteraemia was performed in the Estrie region of Quebec, Canada, between 1991 and 2005. The primary outcome was all-cause 30-day mortality. Between 1991-1993 and 2003-2005, the proportion of cases attributed to endocarditis and pneumonia increased from 4% to 11% and from 2% to 11%, respectively, while that attributed to catheter infections decreased from 49% to 17%. MRSA was almost absent in 1991-1999, but accounted for 10% and 20% of cases in 2000-2002 and 2003-2005, respectively. The population incidence of bacteraemia caused by methicillin-susceptible S. aureus (MSSA) remained stable between 1997 and 2005, while that of MRSA increased from 0 to 7.4/100 000. Risk-factors for mortality included age, co-morbidities, female gender, residence outside the city of Sherbrooke, pneumonia (OR 3.35, 95% CI 1.96-5.73) or endocarditis (OR 2.89, 95% CI 1.67-5.01) as the source, and an absence of treatment. After adjusting for confounders, patients with MRSA bacteraemia had a higher mortality rate than those with MSSA bacteraemia (OR 2.21, 95% CI 0.99-4.96, p 0.053). Mortality in patients with MSSA bacteraemia was 19% (16/83) in 1991-1993, 23% (26/113) in 1994-1996, 29% (50/173) in 1997-1999, and 28% (52/185) in 2000-2002, decreasing to 15% (28/192) in 2003-2005, which impacted on the relative mortality rates of MRSA and MSSA. MRSA did not replace, but added to, an existing stable incidence of MSSA bacteraemia.     

Overexpression of activated murine Notch1 and Notch3 in transgenic mice blocks mammary gland development and induces mammary tumors

The mouse mammary tumor virus (MMTV) provirus was found to target the Notch1 gene, producing insertional mutations in mammary tumors of MMTV/neu transgenic (Tg) mice. In these mammary tumors, the Notch1 gene is truncated upstream of the transmembrane domain, and the resulting Notch1 intracellular domain (Notch1(intra)), deleted of most extracellular sequences, is overexpressed. Although Notch1(intra) transforms mammary epithelial cells in vitro, its role in mammary gland tumor formation in vivo was not studied. Therefore, we generated MMTV/Notch1(intra) Tg mice that overexpress murine Notch1(intra) in the mammary glands. We observed that MMTV/Notch1(intra) Tg females were unable to feed their pups because of impaired ductal and lobulo-alveolar mammary gland development. This was associated with decreased proliferation of ductal and alveolar epithelial cells during rapid expansion at puberty and in early pregnancy, as well as decreased production of beta-casein. Notch1(intra) repressed expression of the beta-casein gene promoter, as assessed in vitro with a beta-casein/luciferase reporter construct. The MMTV/Notch1(intra) Tg females developed mammary gland tumors, confirming the oncogenic potential of Notch1(intra) in vivo. Furthermore, MMTV/Notch3(intra) Tg mice exhibited a very similar phenotype. Thus, these Tg mice represent novel models for studying the role of Notch1 or Notch3 in the development and transformation of the mammary gland.     

Time estimation in chronic insomnia sufferers

STUDY OBJECTIVE: The objective of the present study is 2-fold: (1) compare the time-estimation performance of chronic insomnia sufferers to that of good sleepers and (2) evaluate the severity of the sleep complaint in order to assess its association with the time-estimation performance. DESIGN: Between subjects design. PARTICIPANTS: The sample included 11 individuals suffering from chronic primary insomnia (7 women and 4 men, mean age = 44.64 years, SD = 12.71) and 11 good sleepers (5 women and 6 men, mean age = 48.00 years, SD = 7.86). INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: All participants completed a time-estimation task, namely a finger-tapping task. The results indicate no significant between-group differences on time-estimation data, as well as no significant relationship between severity of insomnia complaint and estimation of time. CONCLUSION: These results suggest that the tendency to misestimate sleep difficulties is not linked to impaired time estimation-specific processes in insomnia sufferers, as measured with the present task.