147 research outputs found

    An investigation into coach developers’ theories in practice, learning and development on a Continuing Professional Development course

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    Despite the importance of the coach developer in supporting coach learning, there is a limited understanding of how they develop. In response, this study explored the theories in practice of twenty-three English coach developers who undertook a continuing professional development (CPD) course. Data were collected through semi-structured interviews, focus groups, and observations of coach developers’ practice and engagement on the course. The data were analysed using a phronetic-iterative approach, with Argyris and Schön’s ideas on theories in practice, mostly espoused theories and theories-in-use, providing the primary heuristic framework. The findings identified how before the CPD course the coach developers articulated espoused theories but as the course progressed there was a move to theories-in-use. This was due to their (re)constructed understanding of learning and working environment. The findings are discussed in light of how the CPD course, and tutors’ pedagogic approaches, influenced the coach developers’ knowledge and understanding. Based on these findings, it seems there is much to gain from supporting coach developers with a deconstruction and reconstruction of theories in practice

    Prediction of bronchopulmonary dysplasia by the chest radiographic thoracic area on day one in infants with exomphalos:Prediction of BPD in infants with exomphalos

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    Objectives: To determine if infants with exomphalos had abnormal antenatal lung growth as indicated by lower chest radiographic thoracic areas (CRTA) on day one compared to controls and whether the CRTA could predict the development of bronchopulmonary dysplasia (BPD). Methods: Infants with exomphalos cared for between January 2004 and January 2023 were included. The controls were term, newborn infants ventilated for absent respiratory drive at birth, without lung disease and had no supplemental oxygen requirement by 6 h of age. The radiographs were imported as digital image files by Sectra PACS software (Sectra AB, Linköping, Sweden). Free-hand tracing of the perimeter of the thoracic area was undertaken and the CRTA calculated by the software. Results: Sixty-four infants with exomphalos and 130 controls were included. Infants with exomphalos had a lower median (IQR) CRTA (1,983 [1,657-2,471] mm2) compared to controls (2,547 [2,153-2,932] mm2, p&lt;0.001). Following multivariable regression analysis, infants with exomphalos had lower CRTAs compared to controls (p=0.001) after adjusting for differences in gestational age and male sex. In the exomphalos group, the CRTAs were lower in those who developed BPD (n=14, 1,530 [1,307-1,941] mm2) compared to those who did not (2,168 [1,865-2,672], p&lt;0.001). Following multivariable regression analysis, the CRTA was associated with BPD development (p=0.021) after adjusting for male sex and gestational age. Conclusions: Lower CRTAs on day one in the exomphalos infants compared to the controls predicted BPD development.</p

    Episomal Viral cDNAs Identify a Reservoir That Fuels Viral Rebound after Treatment Interruption and That Contributes to Treatment Failure

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    Viral reservoirs that persist in HIV-1 infected individuals on antiretroviral therapy (ART) are the major obstacle to viral eradication. The identification and definition of viral reservoirs in patients on ART is needed in order to understand viral persistence and achieve the goal of viral eradication. We examined whether analysis of episomal HIV-1 genomes provided the means to characterize virus that persists during ART and whether it could reveal the virus that contributes to treatment failure in patients on ART. For six individuals in which virus replication was highly suppressed for at least 20 months, proviral and episomal genomes present just prior to rebound were phylogenetically compared to RNA genomes of rebounding virus after therapy interruption. Episomal envelope sequences, but not proviral envelope sequences, were highly similar to sequences in rebounding virus. Since episomes are products of recent infections, the phylogenetic relationships support the conclusion that viral rebound originated from a cryptic viral reservoir. To evaluate whether the reservoir revealed by episomal sequence analysis was of clinical relevance, we examined whether episomal sequences define a viral population that contributes to virologic failure in individuals receiving the CCR5 antagonist, Vicriviroc. Episomal envelope sequences at or near baseline predicted treatment failure due to the presence of X4 or D/M (dual/mixed) viral variants. In patients that did not harbor X4 or D/M viruses, the basis for Vicriviroc treatment failure was indeterminate. Although these samples were obtained from viremic patients, the assay would be applicable to a large percentage of aviremic patients, based on previous studies. Summarily, the results support the use of episomal HIV-1 as an additional or alternative approach to traditional assays to characterize virus that is maintained during long-term, suppressive ART

    Selective ferroptosis vulnerability due to familial Alzheimer's disease presenilin mutations

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    Mutations in presenilin 1 and 2 (PS1 and PS2) cause autosomal dominant familial Alzheimer's disease (FAD). Ferroptosis has been implicated as a mechanism of neurodegeneration in AD since neocortical iron burden predicts Alzheimer's disease (AD) progression. We found that loss of the presenilins dramatically sensitizes multiple cell types to ferroptosis, but not apoptosis. FAD causal mutations of presenilins similarly sensitizes cells to ferroptosis. The presenilins promote the expression of GPX4, the selenoprotein checkpoint enzyme that blocks ferroptosis by quenching the membrane propagation of lethal hydroperoxyl radicals. Presenilin gamma-secretase activity cleaves Notch-1 to signal LRP8 expression, which then controls GPX4 expression by regulating the supply of selenium into the cell since LRP8 is the uptake receptor for selenoprotein P. Selenium uptake is thus disrupted by presenilin FAD mutations, suppressing GPX4 expression. Therefore, presenilin mutations may promote neurodegeneration by derepressing ferroptosis, which has implications for disease-modifying therapeutics.Peer reviewe

    Cost effectiveness of palivizumab in Spain: an analysis using observational data

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    Objectives: To assess the cost effectiveness of palivizumab for prevention of severe respiratory syncytial virus (RSV) disease in high-risk infants in Spain, incorporating country-specific observational hospitalisation data. Methods: An existing decision tree model, designed using data from a large international clinical trial of palivizumab versus no prophylaxis, was updated to include Spanish observational hospitalisation data. The analysis was performed for preterm children born at or before 32 weeks gestational age, who are at high risk of developing severe RSV disease requiring hospitalisation. Data sources included published literature, official price/tariff lists and national population statistics. The primary perspective of the study was that of the Spanish National Health Service in 2006. Results: The base-case analysis included the direct medical costs associated with palivizumab prophylaxis and hospital care for RSV infections. Use of palivizumab produces an undiscounted incremental cost-effectiveness ratio (ICER) of €6,142 per quality-adjusted life-year (QALY), and a discounted ICER of €12,814/QALY. Conclusion: Palivizumab provides a cost-effective method of prophylaxis against severe RSV disease requiring hospitalisation among preterm infants in Spain

    Surfactant status and respiratory outcome in premature infants receiving late surfactant treatment.

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    BACKGROUND:Many premature infants with respiratory failure are deficient in surfactant, but the relationship to occurrence of bronchopulmonary dysplasia (BPD) is uncertain. METHODS:Tracheal aspirates were collected from 209 treated and control infants enrolled at 7-14 days in the Trial of Late Surfactant. The content of phospholipid, surfactant protein B, and total protein were determined in large aggregate (active) surfactant. RESULTS:At 24 h, surfactant treatment transiently increased surfactant protein B content (70%, p &lt; 0.01), but did not affect recovered airway surfactant or total protein/phospholipid. The level of recovered surfactant during dosing was directly associated with content of surfactant protein B (r = 0.50, p &lt; 0.00001) and inversely related to total protein (r = 0.39, p &lt; 0.0001). For all infants, occurrence of BPD was associated with lower levels of recovered large aggregate surfactant, higher protein content, and lower SP-B levels. Tracheal aspirates with lower amounts of recovered surfactant had an increased proportion of small vesicle (inactive) surfactant. CONCLUSIONS:We conclude that many intubated premature infants are deficient in active surfactant, in part due to increased intra-alveolar metabolism, low SP-B content, and protein inhibition, and that the severity of this deficit is predictive of BPD. Late surfactant treatment at the frequency used did not provide a sustained increase in airway surfactant

    FMRP Mediates mGluR(5)-Dependent Translation of Amyloid Precursor Protein

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    Amyloid precursor protein (APP) facilitates synapse formation in the developing brain, while beta-amyloid (Aβ) accumulation, which is associated with Alzheimer disease, results in synaptic loss and impaired neurotransmission. Fragile X mental retardation protein (FMRP) is a cytoplasmic mRNA binding protein whose expression is lost in fragile X syndrome. Here we show that FMRP binds to the coding region of APP mRNA at a guanine-rich, G-quartet–like sequence. Stimulation of cortical synaptoneurosomes or primary neuronal cells with the metabotropic glutamate receptor agonist DHPG increased APP translation in wild-type but not fmr-1 knockout samples. APP mRNA coimmunoprecipitated with FMRP in resting synaptoneurosomes, but the interaction was lost shortly after DHPG treatment. Soluble Aβ(40) or Aβ(42) levels were significantly higher in multiple strains of fmr-1 knockout mice compared to wild-type controls. Our data indicate that postsynaptic FMRP binds to and regulates the translation of APP mRNA through metabotropic glutamate receptor activation and suggests a possible link between Alzheimer disease and fragile X syndrome

    Neuropeptide Release Is Impaired in a Mouse Model of Fragile X Mental Retardation Syndrome

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    Fragile X syndrome (FXS), an inherited disorder characterized by mental retardation and autism-like behaviors, is caused by the failure to transcribe the gene for fragile X mental retardation protein (FMRP), a translational regulator and transporter of select mRNAs. FXS model mice (Fmr1 KO mice) exhibit impaired neuropeptide release. Release of biogenic amines does not differ between wild-type (WT) and Fmr1 KO mice. Rab3A, an mRNA cargo of FMRP involved in the recruitment of vesicles, is decreased by ∼50% in synaptoneurosomes of Fmr1 KO mice; however, the number of dense-core vesicles (DCVs) does not differ between WT and Fmr1 KO mice. Therefore, deficits associated with FXS may reflect this aberrant vesicle release, specifically involving docking and fusion of peptidergic DCVs, and may lead to defective maturation and maintenance of synaptic connections
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