300 research outputs found

    Vangl2-Regulated Polarisation of Second Heart Field-Derived Cells Is Required for Outflow Tract Lengthening during Cardiac Development.

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    Planar cell polarity (PCP) is the mechanism by which cells orient themselves in the plane of an epithelium or during directed cell migration, and is regulated by a highly conserved signalling pathway. Mutations in the PCP gene Vangl2, as well as in other key components of the pathway, cause a spectrum of cardiac outflow tract defects. However, it is unclear why cells within the mesodermal heart tissue require PCP signalling. Using a new conditionally floxed allele we show that Vangl2 is required solely within the second heart field (SHF) to direct normal outflow tract lengthening, a process that is required for septation and normal alignment of the aorta and pulmonary trunk with the ventricular chambers. Analysis of a range of markers of polarised epithelial tissues showed that in the normal heart, undifferentiated SHF cells move from the dorsal pericardial wall into the distal outflow tract where they acquire an epithelial phenotype, before moving proximally where they differentiate into cardiomyocytes. Thus there is a transition zone in the distal outflow tract where SHF cells become more polarised, turn off progenitor markers and start to differentiate to cardiomyocytes. Membrane-bound Vangl2 marks the proximal extent of this transition zone and in the absence of Vangl2, the SHF-derived cells are abnormally polarised and disorganised. The consequent thickening, rather than lengthening, of the outflow wall leads to a shortened outflow tract. Premature down regulation of the SHF-progenitor marker Isl1 in the mutants, and accompanied premature differentiation to cardiomyocytes, suggests that the organisation of the cells within the transition zone is important for maintaining the undifferentiated phenotype. Thus, Vangl2-regulated polarisation and subsequent acquisition of an epithelial phenotype is essential to lengthen the tubular outflow vessel, a process that is essential for on-going cardiac morphogenesis

    Proceedings of the Salford Postgraduate Annual Research Conference (SPARC) 2011

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    These proceedings bring together a selection of papers from the 2011 Salford Postgraduate Annual Research Conference(SPARC). It includes papers from PhD students in the arts and social sciences, business, computing, science and engineering, education, environment, built environment and health sciences. Contributions from Salford researchers are published here alongside papers from students at the Universities of Anglia Ruskin, Birmingham City, Chester,De Montfort, Exeter, Leeds, Liverpool, Liverpool John Moores and Manchester

    Movement variability in stroke patients and controls performing two upper limb functional tasks: a new assessment methodology

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    Background: In the evaluation of upper limb impairment post stroke there remains a gap between detailed kinematic analyses with expensive motion capturing systems and common clinical assessment tests. In particular, although many clinical tests evaluate the performance of functional tasks, metrics to characterise upper limb kinematics are generally not applicable to such tasks and very limited in scope. This paper reports on a novel, user-friendly methodology that allows for the assessment of both signal magnitude and timing variability in upper limb movement trajectories during functional task performance. In order to demonstrate the technique, we report on a study in which the variability in timing and signal magnitude of data collected during the performance of two functional tasks is compared between a group of subjects with stroke and a group of individually matched control subjects. Methods: We employ dynamic time warping for curve registration to quantify two aspects of movement variability: 1) variability of the timing of the accelerometer signals' characteristics and 2) variability of the signals' magnitude. Six stroke patients and six matched controls performed several trials of a unilateral ('drinking') and a bilateral ('moving a plate') functional task on two different days, approximately 1 month apart. Group differences for the two variability metrics were investigated on both days. Results: For 'drinking from a glass' significant group differences were obtained on both days for the timing variability of the acceleration signals' characteristics (p = 0.002 and p = 0.008 for test and retest, respectively); all stroke patients showed increased signal timing variability as compared to their corresponding control subject. 'Moving a plate' provided less distinct group differences. Conclusion: This initial application establishes that movement variability metrics, as determined by our methodology, appear different in stroke patients as compared to matched controls during unilateral task performance ('drinking'). Use of a user-friendly, inexpensive accelerometer makes this methodology feasible for routine clinical evaluations. We are encouraged to perform larger studies to further investigate the metrics' usefulness when quantifying levels of impairment

    Histological validation of diagnoses of thyroid cancer among adults in the registries of Belarus and the Ukraine

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    In order to evaluate the diagnostic reliability of the thyroid cancers listed in adult registries from the Ukraine and Belarus, a histological review was organised of 327 randomly selected thyroid carcinoma cases diagnosed between 1960 and 1999. A final diagnosis was reached at a 5-day consensus conference by six pathologists who met around a multiheaded microscope. The study concluded with a comparison between the final diagnosis and the initial diagnosis. The pathologists agreed with the initial diagnosis of malignancy in 286 cases (88%). A final diagnosis of papillary, follicular or medullary thyroid carcinoma was reached in 86, 4, and 6% of the cases respectively. In 2.8% of the cases reviewed, diagnostic discrepancies persisted. The percentage of agreement between the final diagnosis and the initial diagnosis was 93%, with a weighted κ-statistic of 0.61 (confidence interval 95% (CI 95%): [0.45-0.77]). In all, 89% of the 286 confirmed cancer cases were in agreement for the type of cancer, with a κ-statistic of 0.56 (CI95%: [0.43-0.69]). The level of agreement differed according to cancer categories, with concordance rates of 94, 40 and 33% for papillary, follicular and medullary thyroid carcinomas respectively. The low prevalence of follicular thyroid carcinomas in the adult population studied calls for further exploration. The discrepancies and classification difficulties encountered were analysed. © 2003 Cancer Research UK

    Facilitative parenting and children's social, emotional and behavioural adjustment

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    Facilitative parenting (FP) supports the development of children’s social and emotional competence and effective peer relationships. Previous research has shown that FP discriminates between children bullied by peers from children who are not bullied, according to reports of teachers. This study investigates the association between FP and children’s social, emotional and behavioral problems, over and above the association with dysfunctional parenting (DP). 215 parents of children aged 5–11 years completed questionnaires about parenting and child behavior, and children and teachers completed measures of child bullying victimization. As predicted, FP accounted for variance in teacher reports of children’s bullying victimization as well as parent reports of children’s social and emotional problems and prosocial behavior better than that accounted for by DP. However for children’s reports of peer victimization the whole-scale DP was a better predictor than FP. Contrary to predictions, FP accounted for variance in conduct problems and hyperactivity better than DP. When analyses were replicated substituting subscales of dysfunctional and FP, a sub-set of FP subscales including Warmth, Supports Friendships, Not Conflicting, Child Communicates and Coaches were correlated with low levels of problems on a broad range of children’s adjustment problems. Parent–child conflict accounted for unique variance in children’s peer victimization (teacher report), peer problems, depression, emotional problems, conduct problems and hyperactivity. The potential relevance of FP as a protective factor for children against a wide range of adjustment problems is discussed

    Predation on Multiple Trophic Levels Shapes the Evolution of Pathogen Virulence

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    The pathogen virulence is traditionally thought to co-evolve as a result of reciprocal selection with its host organism. In natural communities, pathogens and hosts are typically embedded within a web of interactions with other species, which could affect indirectly the pathogen virulence and host immunity through trade-offs. Here we show that selection by predation can affect both pathogen virulence and host immune defence. Exposing opportunistic bacterial pathogen Serratia marcescens to predation by protozoan Tetrahymena thermophila decreased its virulence when measured as host moth Parasemia plantaginis survival. This was probably because the bacterial anti-predatory traits were traded off with bacterial virulence factors, such as motility or resource use efficiency. However, the host survival depended also on its allocation to warning signal that is used against avian predation. When infected with most virulent ancestral bacterial strain, host larvae with a small warning signal survived better than those with an effective large signal. This suggests that larval immune defence could be traded off with effective defence against bird predators. However, the signal size had no effect on larval survival when less virulent control or evolved strains were used for infection suggesting that anti-predatory defence against avian predators, might be less constrained when the invading pathogen is rather low in virulence. Our results demonstrate that predation can be important indirect driver of the evolution of both pathogen virulence and host immunity in communities with multiple species interactions. Thus, the pathogen virulence should be viewed as a result of both past evolutionary history, and current ecological interactions

    Drug adherence and multidisciplinary care in patients with multiple sclerosis: Protocol of a prospective, web-based, patient-centred, nation-wide, Dutch cohort study in glatiramer acetate treated patients (CAIR study)

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    Background: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system, for which no definitive treatment is available. Most patients start with a relapsing-remitting course (RRMS). Disease-modifying drugs (DMDs) reduce relapses and disability progression. First line DMDs include glatiramer acetate (GA), interferon-beta (INFb)-1a and INFb-1b, which are all administered via injections. Effectiveness of DMD treatment depends on adequate adherence, meaning year-long continuation of injections with a minimum of missed doses. In real-life practice DMD-treated patients miss 30% of doses. The 6-month discontinuation rate is up to 27% and most patients who discontinue do so in the first 12 months.Treatment adherence is influenced by the socio-economic situation, health care and caregivers, disease, treatment and patient characteristics. Only a few studies have dealt with adherence-related factors in DMD-treated patients. Self-efficacy expectations were found to be related to GA adherence. Patient education and optimal support improve adherence in general. Knowledge of the aspects of care that significantly relate to adherence could lead to adherence-improving measures. Moreover, identification of patients at risk of inadequate adherence could lead to more efficient care.In the near future new drugs will become available for RRMS. Detailed knowledge on factors prognostic of adherence and on care aspects that are associated with adequate adherence will improve the chances of these drugs becoming effective treatments. We investigate in RRMS patients the relationship between drug adherence and multidisciplinary care, as well as factors associated with adherence. Given the differences in the frequency of administration and in the side effects between the DMDs we decided to study patients treated with the same DMD, GA.Methods/design: The Correlative analyses of Adherence In Relapsing remitting MS (CAIR) study is an investigator-initiated, prospective, web-based, patient-centred, nation-wide cohort study in the Netherlands.The primary objective is to investigate whether GA adherence is associated with specific disciplines of care or quantities of specific care. The secondary objective is to investigate whether GA adherence is associated with specific aspects of the socio-economic situation, health care and caregivers, disease, treatment or patient characteristics.All data are acquired on-line via a study website. All RRMS patients in the Netherlands starting GA treatment are eligible. Patients are informed by neurologists, nurses, and websites from national MS patient organisations. All data, except on disability, are obtained by patient self-reports on pre-defined and random time points. The number of missed doses and the number of patients having discontinued GA treatment at 6 and 12 months are measures of adherence. Per care discipline the number of sessions and the total duration of care are measures of received care. The full spectrum of non-experimental care that is available in the Netherlands is assessed. Care includes 'physical' contacts, contacts by telephone or internet, health-promoting activities and community care activities. Care received over the preceding 14 days is assessed by patients at baseline and every other week thereafter up to month 12. Every 3 months neurologists and nurses record care disciplines to which patients have been referred.The Dutch Adherence Questionnaire-90 (DAQ-90) is a 90-item questionnaire based on the World Health Organisation (WHO) 2003 report on adherence and comprehensively assesses five domains of evidence-based determinants of adherence: socio-economic, health care and caregivers, disease, treatment, and patient-related factors. In addition, self-efficacy is assessed by the MS Self-Efficacy Scale (MSSES), and mood and health-related quality of life (HRQoL) by the Multiple Sclerosis Quality of Life-54 questionnaire (MSQoL-54). Relapses and adverse events probably or definitively related to GA are also reported.Discussion: In this study data is mainly acquired by patients' self-reporting via the internet. On-line data acquisition by patients does not require study visits to the hospital and can easily be integrated into daily life. The web-based nature of the study is believed to prevent missing data and study drop-outs. Moreover, the automated process of filling in questionnaires ensures completeness and consistency, thus improving data quality. The combination of patient-reported outcomes, fully web-based data capture and nation-wide information to all eligible patients are distinguishing features of the study and contribute to its scientific potential.Trial registration: Netherlands Trial Register (NTR): NTR2432
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