The influence of social norms in the context of reducing sugar-sweetened beverages consumption.

OBJECTIVES: This study aimed to examine the factors associated with low sugar-sweetened beverage (SSB) consumption and intention to avoid these products as well as investigate the role of different types of social norms in the adoption of this behaviour. STUDY DESIGN: This study reports the results of a secondary data analysis from a cross-sectional telephone survey. METHODS: A total of 1000 adults were randomly recruited in the province of Québec, Canada, using a random-digit dialling procedure. Eligibility criteria were to be aged between 18 and 64 years; able to answer a questionnaire in French or English; and to reside in the province of Québec. SSB consumption, social norms and variables from the theory of planned behaviour were assessed by means of a questionnaire. Logistic regression analyses were conducted to examine factors associated with behaviour and intention. RESULTS: Consuming <1 SSB per day was significantly associated with intention, perceived behavioural control, and risk perception about tooth decay. Descriptive (perceived prevalence in the close surroundings of one person) and perceived societal norms (perceived broad societal approval/disapproval of the behaviour) were associated with behaviour. All theory of planned behaviour variables (including injunctive norm) and risk perception pertaining to chronic diseases predicted intention to avoid the consumption of ≥1 SSB per day. Sex, age, income, and risk perception pertaining to chronic diseases were associated with perceived societal disapproval of SSB consumption. CONCLUSIONS: This study confirms the importance of social norms in the prediction of SSB consumption but also highlights the need to address motivation and capacities in public health interventions to reduce SSB consumption.

A theory of planned behaviour perspective on practitioners' beliefs toward the integration of the WIXX communication campaign messages and activities into daily practice.

OBJECTIVES: To favour the dissemination and the implementation of the WIXX multimedia communication campaign, the aim of this study was to examine practitioners' beliefs towards the integration of the WIXX campaign activities into daily practice. STUDY DESIGN: An exploratory qualitative study. METHODS: Overall, 58 community-based practitioners completed an online questionnaire based on the theory of planned behaviour guidelines pertaining to perceived advantages/disadvantages and perceived barriers/facilitators toward the campaign. A content analysis was performed by two independent coders to extract modal beliefs. Results were validated by a third coder. RESULTS: Local partners had a positive attitude toward the WIXX campaign, but significant barriers remained and needed to be addressed to ensure full implementation of this campaign (e.g. lack of time or resources, additional workload, complexity of the registration process and so forth). Beliefs were fragmented and diversified, indicating that they were highly context dependent. CONCLUSIONS: To conclude, some remaining challenges regarding the full implementation of the WIXX communication campaign were identified, suggesting that additional efforts might be needed to ensure the full adoption of the campaign by local practitioners.

Correlates and moderators of physical activity in parent-tween dyads: a socio-ecological perspective.

OBJECTIVES: The identification of correlates and moderators of physical activity (PA) among parents and their children can support the development of more effective interventions. The aims of this study were to identify individual- and family-level predictors of PA among parent-tween dyads and to examine the moderating role of socio-economic status (SES) on these associations. STUDY DESIGN: As part of a larger investigation, a cross-sectional telephone survey was conducted in 2012 among 1000 parent-child dyads. METHODS: Children were aged between nine and 13 years (tweens). Frequency of participation in PA was self-reported by means of questionnaires. Multilevel modelling was used. Individual predictors included body mass index and sedentary lifestyles whereas family-level predictors included parents' cognitions, family co-participation in PA, and socio-economic characteristics. RESULTS: Significant between-dyad variability in PA was observed among parent-daughter dyads (n = 470, ICC = 0.17, P < 0.001) but not parent-son dyads (n = 520, ICC = 0.01, P = 0.37). Sedentary activity (ps < 0.001) and co-participation in PA (ps < 0.001) were associated with greater PA. Positive parental perceptions of facilitating factors and greater self-efficacy were associated with PA among parent-daughter dyads (ps < 0.04) while parents' outcomes expectancies were associated with PA among parent-son dyads (P = 0.04). The relationship between facilitating factors and PA was moderated by SES (education) among parent-daughter dyads (P = 0.009). CONCLUSIONS: Promoting co-participation in PA and less sedentary activities appear as useful targets for increasing PA among parents and tweens. Additional strategies might be considered according to the sex of the children and family SES. Future research addressing socio-economic inequalities in the correlates of PA among families with tween girls is required.

The effect of theory-based interventions on physical activity participation among overweight/obese individuals: a systematic review.

Little attention has been paid to the evaluation of the long-term impact of theory-based interventions on physical activity participation among overweight/obese individuals after the interventions have ended. The primary aim of this systematic review was to investigate the long-term effectiveness of theory-based interventions increasing physical activity and identify the most effective techniques for behaviour change among overweight/obese individuals. The secondary aim was to investigate the effect of these interventions on theoretical variables. Eighteen studies were reviewed. Among these studies, three reported significant short-term and two long-term effects of interventions on physical activity participation. Most of the studies observed a significant short- or long-term effect of time on this behaviour. Theoretical frameworks most often applied included the Behavioural Model and the Social Learning/Cognitive Theory. However, few of the studies reported any impact on theoretical variables. The most prevalent techniques consisted of providing opportunities for social comparison and instruction as well as self-monitoring. Leading techniques differentiating the experimental group from the control group included prompting practice and intentions formation and barriers identification. Although the combination of these three techniques appears successful, the long-term impact of theory-based interventions remains ambiguous.

Key beliefs for targeted interventions to increase physical activity in children: analyzing data from an extended version of the theory of planned behaviour.

Given the high prevalence of overweight and low levels of physical activity among children, a better understanding of physical activity behaviour is an important step in intervention planning. This study, based on the theory of planned behaviour, was conducted among 313 fifth graders and their parents. Children completed a computer-based questionnaire to evaluate theoretical constructs and behaviour. Additional information was obtained from parents by means of a questionnaire. Correlates of children's physical activity were intention and self-identity. Determinants of intention were self-efficacy, self-identity, and attitude. Parental variables were mediated through cognitions. Among girls, practicing sedentary activities was an additional negative determinant of intention. Key beliefs of boys and girls were related to time management and difficulties associated with physical activity. For girls, social identification as an active girl was another important belief related to positive intention. This study provides theory-based information for the development of more effective interventions aimed at promoting physical activity among children.

Effect of an enriched cholesterol diet during gestation on fatty acid synthase, HMG-CoA reductase and SREBP-1/2 expressions in rabbits.

Pregnancy is associated with hyperlipidemia and hypercholesterolemia in humans. These changes take place to support fetal growth and development, and modifications of these maternal concentrations may influence lipids and cholesterol synthesis in the dam, fetus and placenta. Administration of a 0.2% enriched cholesterol diet (ECD) during rabbit gestation significantly increased cholesterol and triglyceride (TG) levels in maternal livers and decreased fetal weight by 15%. Here we used Western blot analysis to examine the impact of gestation and 0.2% ECD on the expression levels of fatty acid synthase (FAS), HMGR and SREBP-1/2, which are involved in either lipid or cholesterol synthesis. We confirmed that gestation modifies the hepatic and circulating lipid profile in the mother. Our data also suggest that the maternal liver mainly supports lipogenesis, while the placenta plays a key role in cholesterol synthesis. Thus, our data demonstrate a decrease in HMGR protein levels in dam livers by feeding an ECD. In the placenta, SREBPs are highly expressed, and the ECD supplementation increased nuclear SREBP-1/2 protein levels. In addition, our results show a decrease in FAS protein levels in non-pregnant liver and in the liver of offspring from ECD-treated animals. Finally, our data suggest that the placenta does not modify its own cholesterol synthesis in response to an increase in circulating cholesterol. However, the dam liver compensates for this increase by essentially decreasing the level of HMGR expression. Because HMGR and FAS expressions do not correlate with the circulating lipid profile, it would be interesting to find which genes are then targeted by SREBP-1/2 during gestation.

[Early phase of HHV6 infection: role of IE1 and IE2 proteins]. / La phase très précoce de l'infection par le sixième herpèsvirus humain: rôle des protéines IE1 et IE2.

Human herpesvirus 6 (HHV6) is an opportunistic pathogen whose infection or reactivation is associated with diseases such as roseola, central nervous system disorders and organ transplant anomalies. Following its entry into the host cell, the virus utilizes the cellular machinery in order to transcribe its genes and insure the replicative cycle progression. HHV-6 can also latently persist in its host. Immediate-early proteins are rapidly expressed upon cell infection. In particular, IE1 and IE2 proteins play an important role in the establishment of infection. IE1 inhibits interferon-b transcription and may participate in the PML nuclear body aggregation induced by the viral infection. IE2 is a strong transactivator of multiple cell and viral promoters, and contributes to the initiation of the replicative cycle. In this review we have synthesized the current body of knowledge pertaining to the immediate early phase of HHV6 infection, including the role of immediate-early proteins in the replicative cycle and during latency, as well as that of the promoter who regulates their expression.

Human herpesvirus 8 viral FLICE-inhibitory protein inhibits Fas-mediated apoptosis through binding and prevention of procaspase-8 maturation.

Viral FLICE-inhibitory proteins (v-FLIPs) encoded by several herpesviruses and poxviruses share the ability to inhibit apoptosis after engagement of death receptors. In the current article, we provide insights into the mechanisms by which the v-FLIP of human herpesvirus 8 (HHV-8) (also referred to as Kaposi's sarcoma-associated virus) protects cells from apoptosis after Fas-induced signaling. Using v-FLIP expression vectors, our results clearly show that HHV-8 v-FLIP reduces the cleavage of procaspase-8 into its active p18 and p10 protease subunits upon Fas-induced cell death. These results were confirmed by lower caspase-8 and caspase-3 protease activities in extracts of HeLa cells expressing HHV-8 v-FLIP. Coimmunoprecipitation studies further indicate that HHV-8 v-FLIP physically interacts with procaspase-8, but not with Fas-associated protein with death domain in the cellular cytoplasm. These results suggest that binding of HHV-8 v-FLIP to procaspase-8 affects the recruitment and the activation of the latter at the death-induced signaling complex, resulting in diminished apoptotic cascade initiation. Because cellular FLIP was recently reported to modulate promoter containing NF-kappaB motifs and that both HHV-8 and human immunodeficiency virus type 1 (HWV-1) can infect monocytes, we studied the effects of v-FLIP on HIV-1 gene expression. Cotransfection experiments indicated that v-FLIP expression is associated with activation of HIV long terminal repeats: events that were strictly dependent on the presence of NF-kappaB consensus elements. In conclusion, HHV-8 v-FLIP can possibly contribute to the pathogenesis of both HHV-8 and HIV-1 through impaired Fas-dependent killing of infected cells by cytotoxic T cells and through activation of HIV gene expression.

Strength and regulation of the different promoters for chromosomal beta-lactamases of Klebsiella oxytoca.

The two groups of chromosomal beta-lactamases from Klebsiella oxytoca (OXY-1 and OXY-2) can be overproduced 73- to 223-fold, due to point mutations in the consensus sequences of their promoters. The different versions of promoters from blaOXY-1 and blaOXY-2 were cloned upstream of the chloramphenicol acetyltransferase (CAT) gene of pKK232-8, and their relative strengths were determined in Escherichia coli and in K. oxytoca. The three different mutations in the OXY beta-lactamase promoters resulted in a 4- to 31-fold increase in CAT activity compared to that of the wild-type promoter. The G-->T transversion in the first base of the -10 consensus sequence caused a greater increase in the promoter strength of the wild-type promoter than the two other principal mutations (a G-to-A transition of the fifth base of the -10 consensus sequence and a T-to-A transversion of the fourth base of the -35 sequence). The strength of the promoter carrying a double mutation (transition in the Pribnow box and the transversion in the -35 hexamer) was increased 15- to 61-fold in comparison to that of the wild-type promoter. A change from 17 to 16 bp between the -35 and -10 consensus sequences resulted in a ninefold decrease of the promoter strength. The expression of the blaOXY promoter in E. coli differs from that in K. oxytoca, particularly for promoters carrying strong mutations. Furthermore, the blaOXY promoter appears not to be controlled by DNA supercoiling or an upstream curved DNA, but it is dependent on the gene copy number.

Point mutations in the integron integrase IntI1 that affect recombination and/or substrate recognition.

The site-specific recombinase IntI1 found in class 1 integrons catalyzes the excision and integration of mobile gene cassettes, especially antibiotic resistance gene cassettes, with a site-specific recombination system. The integron integrase belongs to the tyrosine recombinase (phage integrase) family. The members of this family, exemplified by the lambda integrase, do not share extensive amino acid identities, but three invariant residues are found within two regions, designated box I and box II. Two conserved residues are arginines, one located in box I and one in box II, while the other conserved residue is a tyrosine located at the C terminus of box II. We have analyzed the properties of IntI1 variants carrying point mutations at the three conserved residues of the family in in vivo recombination and in vitro substrate binding. We have made four proteins with mutations of the conserved box I arginine (R146) and three mutants with changes of the box II arginine (R280); of these, MBP-IntI1(R146K) and MBP-IntI1(R280K) bind to the attI1 site in vitro, but only MBP-IntI1(R280K) is able to excise cassettes in vivo. However, the efficiency of recombination and DNA binding for MBP-IntI1(R280K) is lower than that obtained with the wild-type MBP-IntI1. We have also made two proteins with mutations of the tyrosine residue (Y312), and both mutant proteins are similar to the wild-type fusion protein in their DNA-binding capacity but are unable to catalyze in vivo recombination.

DNA complexes obtained with the integron integrase IntI1 at the attI1 site.

Integrons are genetic elements that are able to capture genes by a site-specific recombination mechanism. Integrons contain a gene coding for a lambda-like integrase that carries out site-specific recombination by interacting with two different target sites; the attI site and the palindromic sequence attC (59 base element). Cassette integrations usually involve the attI site, while cassette excisions use attC . Therefore, the integrase should bind both sites to cleave DNA and perform site-specific recombination reactions. We have used purified maltose-binding protein fused with the integrase (MBP-IntI1) and native IntI1 protein and gel retardation assays with fragments containing the complete and partial attI1 site to show formation of four complexes in this region. Chemical modification of specific nucleotides within the attI1 site was used to investigate their interference with binding of the integrase protein. We attribute IntI1 specific binding to four regions in the attI1 site and a GTTA consensus sequence is found in three of the four regions. Interference by modified guanine and thymine residues in the DNA major groove and adenine residues in the minor groove were observed, indicating that the integrase interacts with both sides of the helix. Binding of IntI1 to attC is also discussed.

In vitro characterization of cytochrome P450 2D6 inhibition by classic histamine H1 receptor antagonists.

Classic antihistamines, namely diphenhydramine, chlorpheniramine, clemastine, perphenazine, hydroxyzine, and tripelennamine, share structural features with substrates and inhibitors of the polymorphic cytochrome P450 (CYP) isozyme CYP2D6. Therefore, the current study was undertaken to characterize the in vitro inhibition of CYP2D6 by these commonly used, histamine H1 receptor antagonists. Microsomal incubations were performed using bufuralol as a specific CYP2D6 substrate and microsomes derived from human cells transfected with CYP2D6 cDNA. Reaction velocities were assessed in the absence and presence of antihistamines (20 microM) at 11 substrate concentrations (1, 2.5, 5, 7.5, 10, 15, 20, 25, 50, 75, and 100 microM), as well as at three nonsaturating substrate concentrations (2.5, 5, and 20 microM) and three inhibitor concentrations (5, 20, and 50 microM). In the presence of all antihistamines, the Vmax and KM of bufuralol 1'-hydroxylation were significantly altered, compared with the uninhibited reaction (p < 0.05). Lineweaver-Burke plots suggested competitive inhibition of the reaction by diphenhydramine and mixed inhibition by all other antihistamines tested. Diphenhydramine and chlorpheniramine, with estimated Ki values of approximately 11 microM, were the weakest inhibitors of CYP2D6 in vitro. Whereas tripelennamine, promethazine, and hydroxyzine were similar in their inhibitory capacities (Ki approximately 4-6 microM), clemastine appeared to be significantly more potent, with a Ki of approximately 2 microM. These data demonstrate that classic histamine H1 receptor antagonists, available in over-the-counter preparations, inhibit CYP2D6 in vitro. Furthermore, the CYP2D6-inhibitory concentrations of these antihistamines are in the range of their expected hepatic blood concentrations, suggesting that, under specific circumstances, clinically relevant interactions between classic antihistamines and CYP2D6 substrates might occur.

A competitive enzyme immunoassay for albuterol: its application for the drug screening in urine.

A competitive enzyme immunoassay using purified monoclonal IgG1 and an alkaline phosphatase-albuterol derivative has been developed for the quantification of albuterol in urine. The calibration curve obtained in optimal incubation conditions is characterized by a minimum detectable level of 26 fmol/well and a working range from 52 fmol to 4,2 pmol/well. This method allows the precise and accurate quantification of albuterol in horse urine without any clean up or extraction step. Moreover the definition of its specificity shows a cross-reactivity of the antibody with the glucurono-/sulfo-conjugates of albuterol. This property is particularly interesting for the screening of urinary albuterol residues in meat producing animals.