138 research outputs found
Structural rearrangements underlying ligand-gating in Kir channels
Inward rectifier potassium (Kir) channels are physiologically regulated by a wide range of ligands that all act on a common gate, although structural details of gating are unclear. Here we show, using small molecule fluorescent probes attached to introduced cysteines, the molecular motions associated with gating of KirBac1.1 channels. The accessibility of the probes indicates a major barrier to fluorophore entry to the inner cavity. Changes in FRET between fluorophores attached to KirBac1.1 tetramers show that PIP(2)-induced closure involves tilting and rotational motions of secondary structural elements of the cytoplasmic domain that couple ligand binding to a narrowing of the cytoplasmic vestibule. The observed ligand-dependent conformational changes in KirBac1.1 provide a general model for ligand-induced Kir channel gating at the molecular level
Secondary anionic phospholipid binding site and gating mechanism in Kir2.1 inward rectifier channels
Inwardly rectifying potassium (Kir) channels regulate multiple tissues. All Kir channels require interaction of phosphatidyl-4,5-bisphosphate (PIP(2)) at a crystallographically identified binding site, but an additional nonspecific secondary anionic phospholipid (PL(â)) is required to generate high PIP(2) sensitivity of Kir2 channel gating. The PL(â)-binding site and mechanism are yet to be elucidated. Here we report docking simulations that identify a putative PL(â)-binding site, adjacent to the PIP(2)-binding site, generated by two lysine residues from neighbouring subunits. When either lysine is mutated to cysteine (K64C and K219C), channel activity is significantly decreased in cells and in reconstituted liposomes. Directly tethering K64C to the membrane by modification with decyl-MTS generates high PIP(2) sensitivity in liposomes, even in the complete absence of PL(â)s. The results provide a coherent molecular mechanism whereby PL(â) interaction with a discrete binding site results in a conformational change that stabilizes the high-affinity PIP(2) activatory site
Learning from the children : exploring preschool children's encounters with ICT at home
This paper is an account of our attempts to understand preschool children's experiences with information and communication technologies (ICT) at home. Using case study data, we focus on what we can learn from talking directly to the children that might otherwise have been overlooked and on describing and evaluating the methods we adopted to ensure that we maximised the children's contributions to the research. By paying attention to the children's perspectives we have learned that they are discriminating users of ICT who evaluate their own performances, know what gives them pleasure and who differentiate between operational competence and the substantive activities made possible by ICT
Structural basis of control of inward rectifier Kir2 channel gating by bulk anionic phospholipids
Inward rectifier potassium (Kir) channel activity is controlled by plasma membrane lipids. Phosphatidylinositol-4,5-bisphosphate (PIP(2)) binding to a primary site is required for opening of classic inward rectifier Kir2.1 and Kir2.2 channels, but interaction of bulk anionic phospholipid (PL(â)) with a distinct second site is required for high PIP(2) sensitivity. Here we show that introduction of a lipid-partitioning tryptophan at the second site (K62W) generates high PIP(2) sensitivity, even in the absence of PL(â). Furthermore, high-resolution x-ray crystal structures of Kir2.2[K62W], with or without added PIP(2) (2.8- and 2.0-Ă
resolution, respectively), reveal tight tethering of the C-terminal domain (CTD) to the transmembrane domain (TMD) in each condition. Our results suggest a refined model for phospholipid gating in which PL(â) binding at the second site pulls the CTD toward the membrane, inducing the formation of the high-affinity primary PIP(2) site and explaining the positive allostery between PL(â) binding and PIP(2) sensitivity
Camilo José Cela en Marbella, 1973
Copia digital. Madrid : Ministerio de EducaciĂłn, Cultura y Deporte. SubdirecciĂłn General de CoordinaciĂłn Bibliotecaria, 201
Manual / Issue 3 / Circus
Manual, a journal about art and its making. Circus. The third issue centers on the theme of Circus. Includes analyses of various pieces in the museum\u27s archive, a fold-out poster by Jim Drain, and a selection of artworks owned by the museum that loosely address said theme.
Softcover, 62 pages. Published 2014 by the RISD Museum. Manual 3 (Circus) contributors include Gina Borromeo, Alison W. Chang, Michelle Clayton, Jim Drain, Daniel Heyman, Andrew Martinez, Ellen McBreen, Thangam Ravindranathan, Rebecca Schneider, Susan Smulyan, and Gwen Strahle.https://digitalcommons.risd.edu/risdmuseum_journals/1002/thumbnail.jp
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M.I.C.E-Mental Health Intervention for Children with Epilepsy: a randomised controlled, multi-centre clinical trial evaluating the clinical and cost-effectiveness of MATCH-ADTC in addition to usual care compared to usual care alone for children and young people with common mental health disorders and epilepsy-study protocol.
BACKGROUND: Mental health disorders in the context of long-term conditions in children and young people are currently overlooked and undertreated. Evidence-based psychological treatments for common childhood mental health disorders (anxiety, depression and disruptive behaviour disorders) have not been systematically evaluated in young people with epilepsy despite their high prevalence in this population. The aim of this multi-site randomised controlled trial is to determine the clinical and cost-effectiveness of adding a modular psychological intervention to usual care for the mental health disorders in comparison to assessment-enhanced usual care alone. METHODS: In total, 334 participants aged 3-18âyears attending epilepsy services will be screened for mental health disorders with the Strengths and Difficulties Questionnaire (SDQ) and the diagnostic Development and Wellbeing Assessment (DAWBA). Those identified as having a mental health disorder and consenting to the trial will be randomised to either receive up to 22 sessions of the modular psychological intervention (MATCH-ADTC) delivered over the telephone over 6âmonths by non-mental health professionals in addition to usual care or to assessment-enhanced usual care alone. Outcomes will be measured at baseline, 6âmonths and 12âmonths post-randomisation. It is hypothesised that MATCH-ADTC plus usual care will be superior to assessment-enhanced usual care in improving emotional and behavioural symptoms. The primary outcome is the SDQ reported by parents at 6âmonths. Secondary outcomes include parent-reported mental health measures such as the Revised Children's Anxiety and Depression Scale, quality of life measures such as the Paediatric Quality of Life Inventory and physical health measures such as the Hague Seizure Severity Scale. Outcome assessors will be blinded to group assignment. Qualitative process evaluations and a health economic evaluation will also be completed. DISCUSSION: This trial aims to determine whether a systematic and integrated approach to the identification and treatment of mental health disorders in children and young people with epilepsy is clinically and cost-effective. The findings will contribute to policies and practice with regard to addressing mental health needs in children and young people with other long-term conditions. TRIAL REGISTRATION: ISRCTN ISRCTN57823197 . Registered on 25 February 2019
Impact of Obesity on Pediatric Acute Recurrent and Chronic Pancreatitis
OBJECTIVE:
The aim of this study was to assess the impact of obesity on pediatric acute recurrent pancreatitis or chronic pancreatitis (CP).
METHODS:
We determined body mass index (BMI) status at enrollment in INSPPIRE (INternational Study group of Pediatric Pancreatitis: In search for a cuRE) cohort using CDC criteria for pediatric-specific BMI percentiles. We used the Cochran-Armitage test to assess trends and the Jonckheere-Terpstra test to determine associations.
RESULTS:
Of 446 subjects (acute recurrent pancreatitis, n = 241; CP, n = 205), 22 were underweight, 258 normal weight, 75 overweight, and 91 were obese. The BMI groups were similar in sex, race, and age at presentation. Hypertriglyceridemia was more common in overweight or obese. Obese children were less likely to have CP and more likely to have acute inflammation on imaging. Compared with children with normal weight, obese or overweight children were older at first acute pancreatitis episode and diagnosed with CP at an older age. Obese or overweight children were less likely to undergo medical or endoscopic treatment, develop exocrine pancreatic insufficiency, and require total pancreatectomy with islet autotransplantation. Diabetes was similar among all groups.
CONCLUSIONS:
Obesity or overweight seems to delay the initial acute pancreatitis episode and diagnosis of CP compared with normal weight or underweight. The impact of obesity on pediatric CP progression and severity deserves further study
Individual and neighborhood-level socioeconomic characteristics in relation to smoking prevalence among black and white adults in the Southeastern United States: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Low individual-level socioeconomic status (SES) is associated with higher prevalence of cigarette smoking. Recent work has examined whether neighborhood-level SES may affect smoking behavior independently from individual-level measures. However, few comparisons of neighborhood-level effects on smoking by race and gender are available.</p> <p>Methods</p> <p>Cross-sectional data from adults age 40-79 enrolled in the Southern Community Cohort Study from 2002-2009 (19, 561 black males; 27, 412 black females; 6, 231 white males; 11, 756 white females) were used in Robust Poisson regression models to estimate prevalence ratios (PRs) and 95% confidence intervals (CI) for current smoking in relation to individual-level SES characteristics obtained via interview and neighborhood-level SES characteristics represented by demographic measures from US Census block groups matched to participant home addresses.</p> <p>Results</p> <p>Several neighborhood-level SES characteristics were modestly associated with increased smoking after adjustment for individual-level factors including lower percentage of adults with a college education and lower percentage of owner-occupied households among blacks but not whites; lower percentage of households with interest, dividends, or net rental income among white males; and lower percentage of employed adults among black females.</p> <p>Conclusions</p> <p>Lower neighborhood-level SES is associated with increased smoking suggesting that cessation programs may benefit from targeting higher-risk neighborhoods as well as individuals.</p
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