218 resultados para longitudinal analyses


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Amphibian skin secretions are unique sources of bioactive peptides and their donor species are currently rapidly disappearing from the biosphere. Here, we report that both peptides and polyadenylated mRNAs from skin granular glands remain amenable to study in samples of stimulated skin secretions following their storage in 0.1 % aqueous trifluoroacetic acid at -20 °C for many years. Frozen acidified solutions of toad (Bombina variegata) skin secretions, stored for 12 years, were thawed and samples removed for direct reverse phase HPLC fractionation. Additional samples were removed, snap frozen and lyophilised for construction of cDNA libraries following polyadenylated mRNA capture using magnetic oligo-dT beads and reverse transcription. Using the bombesin and bradykinin peptides found in bombinid toad skin as models, individual variant peptides of each type were located in reverse phase HPLC fractions and their corresponding biosynthetic precursor-encoding mRNA transcripts were cloned from the cDNA library using a RACE PCR strategy. This study illustrates unequivocally that both amphibian skin secretion peptides and their biosynthetic precursor-encoding polyadenylated mRNAs are stable in frozen acid-solvated skin secretion samples for considerable periods of time-a finding that may have fundamental implications in the study of archived materials but also in the wider field of molecular biology.

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Chronic myelomonocytic leukaemia (CMML) is a heterogeneous haematopoietic disorder characterized by myeloproliferative or myelodysplastic features. At present, the pathogenesis of this malignancy is not completely understood. In this study, we sought to analyse gene expression profiles of CMML in order to characterize new molecular outcome predictors. A learning set of 32 untreated CMML patients at diagnosis was available for TaqMan low-density array gene expression analysis. From 93 selected genes related to cancer and cell cycle, we built a five-gene prognostic index after multiplicity correction. Using this index, we characterized two categories of patients with distinct overall survival (94% vs. 19% for good and poor overall survival, respectively; P = 0.007) and we successfully validated its strength on an independent cohort of 21 CMML patients with Affymetrix gene expression data. We found no specific patterns of association with traditional prognostic stratification parameters in the learning cohort. However, the poor survival group strongly correlated with high-risk treated patients and transformation to acute myeloid leukaemia. We report here a new multigene prognostic index for CMML, independent of the gene expression measurement method, which could be used as a powerful tool to predict clinical outcome and help physicians to evaluate criteria for treatments.

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In collaboration with Airbus-UK, the dimensional growth of aircraft panels while being riveted with stiffeners is investigated. Small panels are used in this investigation. The stiffeners have been fastened to the panels with rivets and it has been observed that during this operation the panels expand in the longitudinal and transverse directions. It has been observed that the growth is variable and the challenge is to control the riveting process to minimize this variability. In this investigation, the assembly of the small panels and longitudinal stiffeners has been simulated using static stress and nonlinear explicit finite element models. The models have been validated against a limited set of experimental measurements; it was found that more accurate predictions of the riveting process are achieved using explicit finite element models. Yet, the static stress finite element model is more time efficient, and more practical to simulate hundreds of rivets and the stochastic nature of the process. Furthermore, through a series of numerical simulations and probabilistic analyses, the manufacturing process control parameters that influence panel growth have been identified. Alternative fastening approaches were examined and it was found that dimensional growth can be controlled by changing the design of the dies used for forming the rivets.

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In a recent study, we reported that the accurate perception of beat structure in music ('perception of musical meter') accounted for over 40% of the variance in single word reading in children with and without dyslexia (Huss et al., 2011). Performance in the musical task was most strongly associated with the auditory processing of rise time, even though beat structure was varied by manipulating the duration of the musical notes.

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BACKGROUND: The relationship between work-related stress and alcohol intake is uncertain. In order to add to the thus far inconsistent evidence from relatively small studies, we conducted individual-participant meta-analyses of the association between work-related stress (operationalised as self-reported job strain) and alcohol intake. METHODOLOGY AND PRINCIPAL FINDINGS: We analysed cross-sectional data from 12 European studies (n?=?142 140) and longitudinal data from four studies (n?=?48 646). Job strain and alcohol intake were self-reported. Job strain was analysed as a binary variable (strain vs. no strain). Alcohol intake was harmonised into the following categories: none, moderate (women: 1-14, men: 1-21 drinks/week), intermediate (women: 15-20, men: 22-27 drinks/week) and heavy (women: >20, men: >27 drinks/week). Cross-sectional associations were modelled using logistic regression and the results pooled in random effects meta-analyses. Longitudinal associations were examined using mixed effects logistic and modified Poisson regression. Compared to moderate drinkers, non-drinkers and (random effects odds ratio (OR): 1.10, 95% CI: 1.05, 1.14) and heavy drinkers (OR: 1.12, 95% CI: 1.00, 1.26) had higher odds of job strain. Intermediate drinkers, on the other hand, had lower odds of job strain (OR: 0.92, 95% CI: 0.86, 0.99). We found no clear evidence for longitudinal associations between job strain and alcohol intake. CONCLUSIONS: Our findings suggest that compared to moderate drinkers, non-drinkers and heavy drinkers are more likely and intermediate drinkers less likely to report work-related stress.

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BACKGROUND: Tobacco smoking is a major contributor to the public health burden and healthcare costs worldwide, but the determinants of smoking behaviours are poorly understood. We conducted a large individual-participant meta-analysis to examine the extent to which work-related stress, operationalised as job strain, is associated with tobacco smoking in working adults. METHODOLOGY AND PRINCIPAL FINDINGS: We analysed cross-sectional data from 15 European studies comprising 166 130 participants. Longitudinal data from six studies were used. Job strain and smoking were self-reported. Smoking was harmonised into three categories never, ex- and current. We modelled the cross-sectional associations using logistic regression and the results pooled in random effects meta-analyses. Mixed effects logistic regression was used to examine longitudinal associations. Of the 166 130 participants, 17% reported job strain, 42% were never smokers, 33% ex-smokers and 25% current smokers. In the analyses of the cross-sectional data, current smokers had higher odds of job strain than never-smokers (age, sex and socioeconomic position-adjusted odds ratio: 1.11, 95% confidence interval: 1.03, 1.18). Current smokers with job strain smoked, on average, three cigarettes per week more than current smokers without job strain. In the analyses of longitudinal data (1 to 9 years of follow-up), there was no clear evidence for longitudinal associations between job strain and taking up or quitting smoking. CONCLUSIONS: Our findings show that smokers are slightly more likely than non-smokers to report work-related stress. In addition, smokers who reported work stress smoked, on average, slightly more cigarettes than stress-free smokers.

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We report a longitudinal study investigating developmental changes in the structure of attention engagement during early infancy. Forty-three infants were observed monthly from 2 to 4 months. Attention engagement was assessed from play interactions with parents, using a coding system developed by Bakeman and Adamson (1984). The results indicated a developmental transition in attention engagement at 3 months: after this age infants engaged for longer periods and in a wider variety of states. Most infants displayed person engagement at 2 months, passive joint engagement at 3 months, and object engagement at 4 months. To address whether emerging abilities of attention engagement allow infants to follow the attention of social partners, we compared attention engagement to performance on an experimental measure of attention control (reported by Perra & Gattis, 2010). Analyses revealed a positive relation between passive joint engagement and checking back, suggesting that changes in passive joint engagement reflect the development in attention control.

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Objectives: Men have higher incidence and mortality rates for nearly all cancers. They are less likely than women to utilise cancer information services and other social support services. The aim of this study was to explore and compare the experience and coping behaviour of men and women after treatment for colorectal cancer (CRC). Methods: A longitudinal qualitative study was conducted involving 38 individuals (24 men and 14 women) with CRC. Data were generated using semi-structured interviews at four time points over an 18-month period, post-diagnosis. Interviews focused on participant's experience of CRC and on how gender affected their coping. This paper reports the findings of interviews 3 and 4 which examined the participant's experience after chemotherapy. Results: Three themes emerged from the interviews ('new normal', living with uncertainty and support needs). Many men and women reacted similarly; however, there was some variation evident between and within sexes. The main difference was with regard to the long-term physical side effects of the illness. Many women admitted to still experiencing side effects, whereas many men indicated that they had no problems. These men engaged in practices that aligned with their gender identity and view of masculinity. It must be noted that some men and women were still experiencing an impact. Conclusions: Recovery from the physical and psychological effects of CRC does not occur simultaneously. Healthcare professionals should be aware that not all men (or women) conform to the social stereotypes of masculinity (or femininity). Copyright © 2010 John Wiley & Sons, Ltd.

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Aim. To report a study measuring the quality of life and side effects in men receiving radiotherapy and hormone ablation for prostate cancer up to 1year after treatment. Background. Prostate cancer incidence is increasing with the result that more men are living longer with the disease and the side effects of treatment. It is important to know the effects this has on their quality of life. Design. Survey. Method. Between September 2006-September 2007, all men who were about to undergo radical conformal radiotherapy ± neo-adjuvant androgen deprivation for localized prostate cancer were invited to participate in the study; 149 men were recruited. They completed the European Organization on Research and Treatment of Cancer quality of life questionnaire C-30 and Prostate Cancer module PR25 at four time-points. Results. At 4-6weeks after radiotherapy, participants experienced the biggest relative decline in global quality of life, social, physical, and role functioning and an increase in treatment side effects. At 6months postradiotherapy the majority of men experienced an improvement in their side effects. However, a minority of men were experiencing severe side effects of radiotherapy at 1year post-treatment. Single men and men who had a low quality of life prior to radiotherapy, reported a lower quality of life at 1year after treatment in comparison to married men. Conclusion. Men with prostate cancer suffer limitations due to the symptoms they experience and disruption to their quality of life. It is essential that nurses develop and deliver follow-up care which is flexible and appropriate to the individual needs of these men. © 2012 Blackwell Publishing Ltd.