Genome-wide meta-analysis of variant-by-diuretic interactions as modulators of lipid traits in persons of European and African ancestry.

Hypertension (HTN) is a significant risk factor for cardiovascular morbidity and mortality. Metabolic abnormalities, including adverse cholesterol and triglycerides (TG) profiles, are frequent comorbid findings with HTN and contribute to cardiovascular disease. Diuretics, which are used to treat HTN and heart failure, have been associated with worsening of fasting lipid concentrations. Genome-wide meta-analyses with 39,710 European-ancestry (EA) individuals and 9925 African-ancestry (AA) individuals were performed to identify genetic variants that modify the effect of loop or thiazide diuretic use on blood lipid concentrations. Both longitudinal and cross sectional data were used to compute cohort-specific interaction results, which were then combined through meta-analysis in each ancestry. These ancestry-specific results were further combined through trans-ancestry meta-analysis. Analysis of EA data identified two genome-wide significant (p < 5 × 10-8) loci with single nucleotide variant (SNV)-loop diuretic interaction on TG concentrations (including COL11A1). Analysis of AA data identified one genome-wide significant locus adjacent to BMP2 with SNV-loop diuretic interaction on TG concentrations. Trans-ancestry analysis strengthened evidence of association for SNV-loop diuretic interaction at two loci (KIAA1217 and BAALC). There were few significant SNV-thiazide diuretic interaction associations on TG concentrations and for either diuretic on cholesterol concentrations. Several promising loci were identified that may implicate biologic pathways that contribute to adverse metabolic side effects from diuretic therapy.

Erythrocyte sedimentation rate as an independent prognostic marker for mortality: a prospective population-based cohort study.

BACKGROUND: A very high erythrocyte sedimentation rate (ESR) is usually an indication of underlying pathology. Additionally, a moderately elevated ESR may also be attributable to biological ageing. Whether the ESR is a prognostic factor for mortality, regardless of age, has been scarcely investigated. Therefore, the objective was to analyse the association between elevated ESR levels and the risk of mortality in a prospective cohort of the general population. METHODS: We studied data from the Rotterdam Study (1990-2014). ESR levels were measured at baseline and individuals were followed until death or end of study. Associations between moderately (20-50 mm h-1 ) and markedly (>50 mm h-1 ) elevated ESR levels and all-cause mortality were assessed using multivariate Cox proportional hazard models. RESULTS: In total, 5226 participants were included, and the mean age was 70.3 years. During a median follow-up time of 14.9 years, 3749 participants died (71.7%). After adjustment, both a moderately elevated ESR and a markedly elevated ESR were associated with a significantly higher risk of overall mortality [hazard ratio (HR) 1.23, 95% confidence interval (CI) 1.12-1.35 and HR 1.89, 95% CI 1.38-2.60, respectively]. Although the ESR becomes higher with age, in a group aged above 75 years, without any comorbidities, an ESR > 20 mm h-1 remained associated with a significantly increased risk of mortality (HR 1.29, 95%CI 1.01-1.64). CONCLUSION: An elevated ESR is an independent prognostic factor for mortality. Despite the fact that ESR increases with age, it remains associated with an increased risk of mortality and warrants close follow-up.

Impact of prediagnostic smoking and smoking cessation on colorectal cancer prognosis: a meta-analysis of individual patient data from cohorts within the CHANCES consortium.

Background: Smoking has been associated with colorectal cancer (CRC) incidence and mortality in previous studies and might also be associated with prognosis after CRC diagnosis. However, current evidence on smoking in association with CRC prognosis is limited. Patients and methods: For this individual patient data meta-analysis, sociodemographic and smoking behavior information of 12 414 incident CRC patients (median age at diagnosis: 64.3 years), recruited within 14 prospective cohort studies among previously cancer-free adults, was collected at baseline and harmonized across studies. Vital status and causes of death were collected for a mean follow-up time of 5.1 years following cancer diagnosis. Associations of smoking behavior with overall and CRC-specific survival were evaluated using Cox regression and standard meta-analysis methodology. Results: A total of 5229 participants died, 3194 from CRC. Cox regression revealed significant associations between former [hazard ratio (HR) = 1.12; 95 % confidence interval (CI) = 1.04-1.20] and current smoking (HR = 1.29; 95% CI = 1.04-1.60) and poorer overall survival compared with never smoking. Compared with current smoking, smoking cessation was associated with improved overall (HR<10 years = 0.78; 95% CI = 0.69-0.88; HR≥10 years = 0.78; 95% CI = 0.63-0.97) and CRC-specific survival (HR≥10 years = 0.76; 95% CI = 0.67-0.85). Conclusion: In this large meta-analysis including primary data of incident CRC patients from 14 prospective cohort studies on the association between smoking and CRC prognosis, former and current smoking were associated with poorer CRC prognosis compared with never smoking. Smoking cessation was associated with improved survival when compared with current smokers. Future studies should further quantify the benefits of nonsmoking, both for cancer prevention and for improving survival among CRC patients, in particular also in terms of treatment response.

Strength exercises during physical education classes in secondary schools improve body composition: a cluster randomized controlled trial.

BACKGROUND: Metabolic health in people with obesity is determined by body composition. In this study, we examined the influence of a combined strength exercise and motivational programme -embedded in the school curriculum- on adolescents body composition and daily physical activity. METHODS: A total of 695 adolescents (11-15y) from nine Dutch secondary schools participated in a one year cluster randomised controlled trial (RCT). In the intervention schools, physical education teachers were instructed to spend 15-30 min of all physical education lessons (2× per week) on strength exercises. Monthly motivational lessons were given to stimulate students to be more physically active. Control schools followed their usual curriculum. The primary outcome measure was body composition assessed by the deuterium dilution technique. Daily physical activity and sedentary behaviour measured by accelerometry served as a secondary outcome. RESULTS: After 1 year, a 1.6% fat mass difference was found in favour of the intervention group (p = .007). This reflected a 0.9 kg difference in fat free mass (intervention>control; p = .041) and 0.7 kg difference in fat mass (intervention

Drop spreading and gelation of thermoresponsive polymers.

Spreading and solidification of liquid droplets are elementary processes of relevance for additive manufacturing. Here we investigate the effect of heat transfer on spreading of a thermoresponsive solution (Pluronic F127) that undergoes a sol-gel transition above a critical temperature Tm. By controlling the concentration of Pluronic F127 we systematically vary Tm, while also imposing a broad range of temperatures of the solid and the liquid. We subsequently monitor the spreading dynamics over several orders of magnitude in time and determine when solidification stops the spreading. It is found that the main parameter is the difference between the substrate temperature and Tm, pointing to a local mechanism for arrest near the contact line. Unexpectedly, the spreading is also found to stop below the gelation temperature, which we attribute to a local enhancement in polymer concentration due to evaporation near the contact line.

The Dutch 'Focus on Strength' intervention study protocol: programme design and production, implementation and evaluation plan.

BACKGROUND: Overweight youngsters are better in absolute strength exercises than their normal-weight counterparts; a physiological phenomenon with promising psychological impact. In this paper we describe the study protocol of the Dutch, school-based program 'Focus on Strength' that aims to improve body composition of 11-13 year old students, and with that to ultimately improve their quality of life. METHODS: The development of this intervention is based on the Intervention Mapping (IM) protocol, which starts from a needs assessment, uses theory and empirical research to develop a detailed intervention plan, and anticipates program implementation and evaluation. This novel intervention targets first year students in preparatory secondary vocational education (11-13 years of age). Teachers are the program implementers. One part of the intervention involves a 30 % increase of strength exercises in the physical education lessons. The other part is based on Motivational Interviewing, promoting autonomous motivation of students to become more physically active outside school. Performance and change objectives are described for both teachers and students. The effectiveness of the intervention will be tested in a Randomized Controlled Trial in 9 Dutch high schools. DISCUSSION: Intervention Mapping is a useful framework for program planning a school-based program to improve body composition and motivation to exercise in 11-13 year old adolescents by a "Focus on Strength". TRIAL REGISTRATION: NTR5676 , registered 8 February 2016 (retrospectively registered).

Who's that girl? A qualitative analysis of adolescent girls' views on factors associated with teenage pregnancies in Bolgatanga, Ghana.

BACKGROUND: Adolescent pregnancy remains a public health concern, with diverse serious consequences, including increased health risk for mother and child, lost opportunities for personal development, social exclusion, and low socioeconomic attainments. Especially in Africa, teenage pregnancy rates are high. It is important to find out how girls without pregnancy experience differ in their contraceptive decision-making processes as compared with their previously studied peers with pregnancy experience to address the high rate of teenage pregnancies. METHODS: We conducted semi-structured in-depth interviews with never been pregnant girls (N = 20) in Bolgatanga, Ghana, to explore the psychosocial and environmental factors influencing the sexual decision making of adolescents. Themes such as relationships, sex, pregnancy, family planning and psychosocial determinants (knowledge, attitudes, self-efficacy, norms, risk perceptions) derived from empirical studies and theories related to sexuality behavior guided the development of the interview protocol. RESULTS: Results showed that the girls did talk about sexuality with their mothers at home and did receive some form of sexual and reproductive health education, including the use of condoms discussions in school. Participants reported high awareness of pregnancy risk related to unprotected sex, were positive about using condoms and indicated strong self-efficacy beliefs towards negotiating condom use. The girls also formulated clear future goals, including coping plans such as ways to prevent unwanted pregnancies to reach these targets. On the other hand, their attitudes towards family planning (i.e., contraceptives other than condoms) were negative, and they hold boys responsible for buying condoms. CONCLUSION: An open parental communication on sexuality issues at home, comprehensive sex education in school and attitude, self-efficacy, risk perception towards contraception, alongside with goal-setting, seem to be protective factors in adolescent girls' pregnancy prevention efforts. These factors should be targets in future intervention programs at the individual, interpersonal, and school and community levels.

Dispensing of potentially teratogenic drugs before conception and during pregnancy: a population-based study.

OBJECTIVE: To study the dispensing of potentially teratogenic drugs in the 12-month period before as well as during pregnancy in the Netherlands. DESIGN: Population-based study. SETTING: A cohort was constructed using a linkage between the PHARMO Database Network and the Netherlands Perinatal Registry (PRN). POPULATION: A total of 203 962 Dutch pregnancies reported between 1999 and 2007 METHODS: Drug-dispensing information was identified from the PHARMO Database Network for the 12-month period before conception and during pregnancy. Drugs with either a Swedish FASS 'D' classification, an Australian ADEC or American FDA 'D' or 'X' classification were considered potentially teratogenic (n = 202). MEAN OUTCOME MEASURES: Proportion of pregnancies that received potentially teratogenic drugs in the 12-month period before and during pregnancy and specific for the risk category X drugs and newly initiated drugs. RESULTS: Sixteen percent of the pregnancies received a potentially teratogenic drug in the 12-month period before and 5.07% during pregnancy. Doxycycline and paroxetine were most frequently received during pregnancy by 1.01% and 0.85% of women, respectively; 0.66% of the women received a risk category X drug during pregnancy which most frequently consisted of triptorelin (0.25%), norethisterone (0.22%) and simvastatin (0.03%). Fifty-three percent of the women who received a potentially teratogenic drug during pregnancy received this for the first time during the study period. These percentages were heterogeneous between therapeutic drug classes. CONCLUSIONS: Five percent of the pregnancies received a potentially teratogenic drug during pregnancy and 0.66% received a drug from the risk category X. It may be possible to reduce these proportions when reasons for prescription have been explored.

Systematic review and meta-analysis of the association between diabetes mellitus and incidence and mortality in breast and colorectal cancer.

BACKGROUND: Increasing evidence suggests that diabetes mellitus (DM) is associated with increased cancer incidence and mortality. Several mechanisms involved in diabetes, such as promotion of cell proliferation and decreased apoptosis, may foster carcinogenesis. This study investigated the association between DM and cancer incidence and cancer-specific mortality in patients with breast and colorectal carcinoma. METHODS: A meta-analysis of controlled trials, prospective cohort studies and pooled cohort studies published after 2007 was conducted. Embase, PubMed and the Cochrane Library were searched. Summary hazard ratios (HRs) were calculated using a random-effects model. Sensitivity and subgroup analyses were performed to adjust for confounders, mode of DM assessment and follow-up time. RESULTS: Twenty studies were included to investigate the association between DM and breast and colorectal cancer incidence and cancer-specific mortality. The studies predominantly comprised patients with type II DM. The overall HR for breast cancer incidence was 1·23 (95 per cent confidence interval 1·12 to 1·34) and that for colorectal cancer was 1·26 (1·14 to 1·40) in patients with DM compared with those without diabetes. The overall HR was 1·38 (1·20 to 1·58) for breast cancer- and 1·30 (1·15 to 1·47) for colorectal cancer-specific mortality in patients with DM compared with those without diabetes. CONCLUSION: This meta-analysis indicated that DM is a risk factor for breast and colorectal cancer, and for cancer-specific mortality.

The effect of thiazide and loop diuretics on urinary levels of free deoxypyridinoline: an osteoclastic bone-resorption marker.

WHAT IS KNOWN AND OBJECTIVE: Diuretics can cause changes in calcium levels due to renal effects. Moreover, calcium levels can also vary as a result of changes in intestinal absorption and in the activity of osteoclastic cells. A marker of osteoclastic bone-resorption activity is the level of urinary free deoxypyridinoline (FDP). Deoxypyridinoline (DP) acts as a cross-link between adjacent collagen chains to provide structural rigidity. Our aim was to investigate the association between use of thiazides and loop diuretics and urinary levels FDP. METHODS: In this follow-up study, data were obtained from the Rotterdam Study, a large population-based prospective cohort study. For a subset of 658 participants, urinary levels of FDP were measured at baseline. Linear regression analysis was performed to assess the association between the use of thiazides and loop diuretics and the urinary levels of FDP. RESULTS: In women, current use of loop diuretics for less than 42 days was associated with an increased level of urinary FDP (+3·43 nmol deoxypyridinoline per mmol urinary creatinine; 95% CI 1·85; 5·02) compared with no use. However, use for a period of more than 42 days was not associated with an increased level of FDP, nor was past use of loop diuretics. For thiazide diuretics, no statistically significant associations were found. WHAT IS NEW AND CONCLUSION: In women, short-term use of loop diuretics is associated with an increased level of FDP, reflecting increased bone resorption by osteoclasts. As the difference disappears with longer term use, the clinical significance is unclear and the value of FDP as a biomarker in this setting is not established. The molecular mechanism for the observed differences in bone fracture rates with use of diuretics remains unclear.

Recurrent and founder mutations in the Netherlands-Phospholamban p.Arg14del mutation causes arrhythmogenic cardiomyopathy.

BACKGROUND: Recently, we showed that the c.40_42delAGA (p.Arg14del) mutation in the phospholamban (PLN) gene can be identified in 10-15 % of Dutch patients with dilated cardiomyopathy or arrhythmogenic cardiomyopathy. The arrhythmogenic burden of the p.Arg14del mutation was illustrated by the high rate of appropriate ICD discharges and a positive family history for sudden cardiac death. METHODS: Our goal was to evaluate the geographical distribution and the origin of this specific mutation in the Netherlands and to get an estimation of the prevalence in a Dutch population cohort. Therefore, we investigated the postal codes of the places of residence of PLN p.Arg14del mutation carriers and places of birth of their ancestors. In addition, a large population-based cohort (PREVEND) was screened for the presence of this mutation. RESULTS: By April 2012, we had identified 101 probands carrying the PLN p.Arg14del mutation. A total of 358 family members were also found to carry this mutation, resulting in a total of 459 mutation carriers. The majority of mutation carriers live in the northern part of the Netherlands and analysing their grandparents' places of birth indicated that the mutation likely originated in the eastern part of the province of Friesland. In the PREVEND cohort we identified six heterozygous PLN p.Arg14del mutation carriers out of 8,267 subjects (0.07 %). CONCLUSION: The p.Arg14del mutation in the PLN gene is the most frequently identified mutation in Dutch cardiomyopathy patients. The mutation that arose 575-825 years ago is likely to have originated from the eastern part of the province of Friesland and is highly prevalent in the general population in the northern part of the Netherlands.

Risk of cancer in patients on insulin glargine and other insulin analogues in comparison with those on human insulin: results from a large population-based follow-up study.

AIMS/HYPOTHESIS: Several publications suggest an association between certain types of insulin and cancer, but with conflicting results. We investigated whether insulin glargine (A21Gly,B31Arg,B32Arg human insulin) is associated with an increased risk of cancer in a large population-based cohort study. METHODS: Data for this study were obtained from dispensing records from community pharmacies individually linked to hospital discharge records from 2.5 million individuals in the Netherlands. In a cohort of incident users of insulin, the association between insulin glargine and other insulin analogues, respectively, and cancer was analysed in comparison with human insulin using Cox proportional hazard models with cumulative duration of drug use as a time-varying determinant. The first hospital admission with a primary diagnosis of cancer was considered as the main outcome; secondary analyses were performed with specific cancers as outcomes. RESULTS: Of the 19,337 incident insulin users enrolled, 878 developed cancer. Use of insulin glargine was associated with a lower risk of malignancies in general in comparison with human insulin (HR 0.75, 95% CI 0.71, 0.80). In contrast, an increased risk was found for breast cancer (HR 1.58, 95% CI 1.22, 2.05). Dose-response relationships could not be identified. CONCLUSION/INTERPRETATION: Users of insulin glargine and users of other insulin analogues had a lower risk of cancer in general than those using human insulin. Both associations might be a consequence of residual confounding, lack of adherence or competing risk. However, as in previous studies, we demonstrated an increased risk of breast cancer in users of insulin glargine in comparison with users of human insulin.

A multidisciplinary and multidimensional intervention for patients with hand osteoarthritis.

BACKGROUND: Although several guidelines recommend that treatment programmes in patients with hand osteoarthritis should be both multidisciplinary and multidimensional, currently no such treatment programme for hand osteoarthritis has been described. Therefore the aim of this study was to systematically develop a multidisciplinary and multidimensional non-pharmacological treatment programme and to give a detailed description on the content of this treatment programme. DEVELOPMENT OF THE TREATMENT PROGRAMME: The programme was developed in phases. In a preclinical theoretical phase, disease-specific problems, current evidence and the influence of patient characteristics on the benefit of interventions were explored. In a modelling phase, the treatment programme was designed. TREATMENT PROGRAMME: The programme contains an individual intake, four weekly nurse and occupational therapist-led group sessions and a booster session after six months. Treatment components of the programme are self-management, daily home exercises to enhance joint mobility and grip strength and education about ergonomic principles. The treatment programme is tailored to the needs of individual patients with hand osteoarthritis. CONCLUSIONS: A non-pharmacological multidisciplinary and multidimensional treatment programme for patients with hand osteoarthritis was developed. Further research is necessary to investigate the effectiveness of this treatment programme. Currently, the programme is being evaluated in an ongoing randomized clinical trial.

Gait speed reference values in community-dwelling older adults - Cross-sectional analysis from the Rotterdam Study.

BACKGROUND: Gait speed is a simple, inexpensive and clinically useful marker of physical function in older adults. We aimed to establish gait speed reference values for community-dwelling older adults. To this end, we further explored the association of age, sex and height with gait speed. METHODS: This study included community-dwelling participants aged 50 years and over enrolled in the Rotterdam Study. Participants completed the gait protocol between 2009 and 2016. The mean gait speed was calculated for age and height groups, stratified by sex. Reference values for gait speed were calculated using a quantile regression model adjusted for sex, the non-linear effects of age and height, as well as the interaction between age and sex plus the interaction between age and height. RESULTS: The study population included 4656 Dutch participants with a mean (standard deviation) age of 67.7 (9.5) years, comprising 2569 (55.2%) women. The mean height of the participants was 1.69 (0.10) meters and the mean gait speed was 1.20 (0.20) m/s. Gait speed was lower with older age and greater with taller stature, but the effect of height disappeared above the age of 80 years. Sex did not affect gait speed after accounting for age and height. Age-, sex-, and height-specific reference values for gait speed are available for use at https://emcbiostatistics.shinyapps.io/GaitSpeedReferenceValues/. CONCLUSIONS: We found that height explains the commonly noted difference in usual gait speed between sexes and that neither height nor sex impacts gait speed in the very oldest adults. We developed reference values for usual gait speed in Western European community-dwelling older adults.

Appendectomy and the subsequent risk of cancer: A prospective population-based cohort study with long follow-up.

BACKGROUND: The appendix, an organ of immunological and microbiological importance, could be involved in the pathogenesis of cancers, but results are inconclusive. Our objective was to assess the association between appendectomy and the subsequent risk of cancer. METHODS: Data were obtained from the Rotterdam Study; a long-term prospective population-based study of individuals aged 55 years and older, of which the first cohort started in 1990 and included 7983 participants. Information on appendectomy was obtained through either medical interview at baseline or linkage with the national automated pathology center (PALGA). Cancer cases were pathology based. End of follow-up was January 1st, 2015. The association between appendectomy and risk of cancer was assessed using Cox proportional hazard models, adjusted for known confounders. RESULTS: Of 7135 included participants, 1373 (19.2%) had undergone an appendectomy and 1632 individuals developed cancer. After adjustment for age, sex, socioeconomic status, BMI, smoking, prevalent diabetes mellitus and alcohol intake, a history of appendectomy was associated with a significantly lower risk of cancer [hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.75-0.98]. Subgroup analyses showed similar results for gastrointestinal cancer (HR 0.75, 95% CI 0.56-0.99), in particular colon cancer (HR 0.65, 95% 0.43-0.97), and cancer of the female reproductive organs (HR 0.35, 95% CI 0.15-0.80). CONCLUSION: Participants who underwent an appendectomy had a reduced risk of cancer in general after adjustment for potential confounders. Therefore, these results contradict earlier studies suggestive of an increased risk. Further research is necessary to replicate these results and reveal its underlying mechanism.

The Obesity Paradox in Lung Cancer: Associations With Body Size Versus Body Shape.

BACKGROUND: The association between obesity and lung cancer (LC) remains poorly understood. However, other indices of obesity on the basis of body shape instead of body size have not been examined yet. The aim of this study was to evaluate the association between different indices of body size and body shape and the risk of LC. In particular, this study examined the association between A Body Shape Index, a more precise indicator of abdominal fat than traditional anthropometric measures, and the risk of LC. METHODS: In the prospective cohort the Rotterdam Study, we analysed data of 9,689 participants. LC diagnoses were based on medical records and anthropometric measurements were assessed at baseline. Cox-regression analyses with corresponding Hazard Ratios were used to examine the association between the anthropometric measurements and the risk of LC with adjustment for potential confounders. Potential non-linear associations were explored with cubic splines using the Likelihood ratio (LR) test. RESULTS: During follow-up, 319 participants developed LC. Body mass Index (BMI) was inversely associated with the risk of lung cancer (HR 0.94, 95% CI: 0.91-0.97) and persisted after excluding lung cancer cases during the first 10 years of follow-up. There was evidence for a non-linear association between BMI and the risk of lung cancer (0,04, df = 1), which indicated that the inverse association between BMI and lung cancer was mainly present in non-obese participants. Waist circumference (WC) (HR 1.03 95% CI: 1.01-1.05), Waist-to-Hip Ratio (WHR) (HR 1.23 95% CI: 1.09-1.38) and ABSI (A Body Shape Index) (HR 1.17 95% CI: 1.05-1.30) were positively and linearly associated with the risk of lung cancer. CONCLUSIONS: Body shape rather than body size may be an important risk indicator of LC. Future research should focus on the role of visceral fat and the risk of LC as well as the underlying mechanisms.

Modelling antecedents of blood donation motivation among non-donors of varying age and education.

Understanding blood donation motivation among non-donors is prerequisite to effective recruitment. Two studies explored the psychological antecedents of blood donation motivation and the generalisability of a model of donation motivation across groups differing in age and educational level. An older well-educated population and a younger less well-educated population were sampled. The studies assessed the role of altruism, fear of blood/needles and donation-specific cognitions including attitudes and normative beliefs derived from an extended theory of planned behaviour (TPB). Across both samples, results showed that affective attitude, subjective norm, descriptive norm, and moral norm were the most important correlates of blood donation intentions. Self-efficacy was more important among the younger less well-educated group. Altruism was related to donation motivation but only indirectly through moral norm. Similarly, fear of blood/needles only had an indirect effect on motivation through affective attitude and self-efficacy. Additional analyses with the combined data set found no age or education moderation effects, suggesting that this core model of donation-specific cognitions can be used to inform future practical interventions recruiting new blood donors in the general population.

Tackling smoking among out of school youth in South Africa: An analysis of friendship ties.

BACKGROUND: Friendships during adolescence play a significant role in the initiation and maintenance of tobacco use. Smoking behaviour among adolescent friends has not been explored among out of school youth (OSY) in South Africa. Out of school youth (OSY), described as those between 13 and 20 years old, have not completed their schooling and are not currently enrolled in school, are at greater risk for tobacco use. AIM: The main aim of this study is to examine whether the smoking behaviour of OSY is associated with that of their OSY friends. METHODS: Respondent driven sampling was used to recruit OSY and their OSY friends. A mixed effects logistic regression with a random intercept across school-province combinations was used to analyse survey data. Race and gender were also incorporated into the analyses as effect moderators (n = 391). RESULTS: Results of this study confirm that cigarette smoking was common among OSY and their OSY friends, with 53.5% of the respondents smoking in the past month (SD = 0.44). When OSY friends were either all non-smokers or half their friends were non-smokers, Coloured (mixed race) OSY were less likely to smoke compared to Black African and Other (mostly Asian descent) OSY. CONCLUSION: Cultural norms and values associated with the different race groups may play a role in the smoking behaviour of out of school youth friends. Understanding this relationship is useful for identifying those OSY that are vulnerable to the behaviours that place them at risk of tobacco related morbidity and mortality.

Identifying blood donors willing to help with recruitment.

BACKGROUND AND OBJECTIVES: Social influence shapes behaviour and donors are ambassadors for blood banks. Donors are role models for family and friends and, therefore, so may be able to help with donor recruitment. MATERIALS AND METHODS: A questionnaire was used to assess donors' willingness to engage in donor recruitment. Measures included willingness to recruit new donors and antecedents of recruitment motivation based on the theory of planned behaviour (TPB). RESULTS: More than half of our participants were willing to try to recruit friends and family (57%). Self-efficacy was the most important correlate of intention to recruit as were cognitive attitude and experience with the blood bank. The findings suggest that the TPB provides a good basis for understanding cognitive antecedents of donors' willingness to recruit other donors. CONCLUSION: Results suggest that using existing donors to recruit new donors could be an efficient and cost-effective way to recruit additional donors. This approach warrants further investigation.

HIV type 1 genetic variability in central Brazil.

This study analyzed the genes pol and env to determine the genetic variability of HIV-1 in Central Brazil. Forty-one isolates of HIV-1-infected individuals had protease, reverse transcriptase, and C2C3/ env amplified by nested PCR and sequenced. The subtype was determined by the program REGA and phylogenetic analyses. The samples identified as putative recombinant forms were analyzed by SimPlot. A high prevalence of subtype B (95.1%) was observed, followed by mosaic viruses B/F (4.9%). The amino acid sequences from 30 HIV-1 isolates were analyzed for the antigenic intrasubtype diversity. The most prevalent gp120 V3 loop motif was the GPGR (United States/Europe) (43.3%), described in B and F subtypes, followed by the GPGK tetrapeptide (10%). The Brazilian variant B" (GWGR), GFGR, and GLGR tetrapeptides were found in 6.7%. Other V3 variants were found in eight isolates (26.7%). Phylogenetic tree analysis was also performed in order to verify the relationship of the HIV-1 samples from Central Brazil with other HIV-1 sequences that circulate in Brazil. The subtype B sequences from Central Brazil formed a polyphyletic cluster in the tree, indicating that these strains are similar to those from other geographic regions. These results contribute to the understanding of HIV in Brazil, and may prove useful for the development of vaccine candidates.