4,530 research outputs found
Epithelial integrin alpha 6 beta 4: complete primary structure of alpha 6 and variant forms of beta 4.
The integrin alpha 6 beta 4 is a heterodimer predominantly expressed by epithelia. While no definite receptor function has yet been assigned to it, this integrin may mediate adhesive and/or migratory functions of epithelial cells. We have determined the complete primary structure of both the alpha 6 and beta 4 subunits from cDNA clones isolated from pancreatic carcinoma cell line libraries. The deduced amino acid sequence of alpha 6 is homologous to other integrin alpha chains (18-26% identity). Antibodies to an alpha 6 carboxy terminus peptide immunoprecipitated alpha 6 beta 4 complexes from carcinoma cells and alpha 6 beta 1 complexes from platelets, providing further evidence for the association of alpha 6 with more than one beta subunit. The deduced amino acid sequence of beta 4 predicts an extracellular portion homologous to other integrin beta chains, and a unique cytoplasmic domain comprised of greater than 1,000 residues. This agrees with the structures of the beta 4 cDNAs from normal epithelial cells (Suzuki, S., and Y. Naitoh. 1990. EMBO [Eur. Mol. Biol. Organ.] J. 9:757-763; Hogervost, F., I. Kuikman, A. E. G. Kr. von dem Borne, and A. Sonnenberg. 1990. EMBO [Eur. Mol. Biol. Organ.] J. 9:765-770). Compared to these structures, however, the beta 4 cDNAs that we have cloned from carcinoma cells contain extra sequences. One of these is located in the 5'-untranslated region, and may encode regulatory sequences. Another specifies a segment of 70 amino acids in the cytoplasmic tail. Amplification by reverse transcription-polymerase chain reaction of mRNA indicated that multiple forms of beta 4 may exist, possibly due to cell-type specific alternative splicing. The unique structure of beta 4 suggests its involvement in novel cytoskeletal interactions. Consistent with this possibility, alpha 6 beta 4 is mostly concentrated on the basal surface of epithelial cells, but does not colocalize with components of adhesion plaques
Rhetoric, organizational category dynamics and institutional change : a study of the UK Welfare State
Accounts of institutional change and categorization conventionally assume that high-status change agents can impose change, even to stable category systems, which lower-status actors accommodate in order to ensure social approval and material resources. By exploring the UK Conservative-Liberal Coalition's rhetorical efforts to reform the welfare state, how welfare providers are categorized and the subsequent response of implicated category members, we offer instead an account of institutional change that exposes the agentic limitations of high-status actors. Whilst governments may well be in a position to impose changes in the formal rules of the game through manipulation of material resources (fiscal contraction, privatization, open markets, deregulation), we find that they cannot necessarily monopolize symbolic resources (identities/cultural features). We also find that deviation from cultural expectations is not only available to large, high-status organizations, low-status actors too have discretion over their responses to institutional pressures regarding how they are categorized and subsequently judged
Citrulline as a marker of intestinal function and absorption in clinical settings: A systematic review and meta-analysis
Background: Citrulline has been described as a marker of intestinal function or absorption but evidence varies according to clinical settings. Objective: The objective of this article is to examine the evidence of plasma citrulline as a marker of intestinal function and absorption in various clinical settings. Methods: Studies were examined for p values, means and standard deviations, correlation coefficients or other metrics depicting the association of citrulline with intestinal function. A random effects model was used to produce a pooled estimate. A hierarchical summary receiver operating curve model was fitted for diagnostic accuracy measures. Results: Citrulline levels are correlated strongly with small bowel length in short bowel syndrome patients (r = 0.67). Citrulline is strongly negatively correlated (r = –0.56) with intestinal disease severity with regards to enteropathies (coeliac disease, tropical enteropathy, Crohn’s disease, mucositis, acute rejection in intestinal transplantation). Citrulline cut-off levels have an overall sensitivity and specificity of 80% and 84% respectively. Citrulline levels in untreated coeliac patients compared to controls were reduced by 10 µmol/l. Citrulline levels increase with gluten-free diet and with improvement of enteropathy. Citrulline is decreased in critical illness and sepsis. Conclusion: These findings allow us to advocate quite reasonably that citrulline is a marker of acute and chronic intestinal insufficiency
10 simple rules to create a serious game, illustrated with examples from structural biology
Serious scientific games are games whose purpose is not only fun. In the
field of science, the serious goals include crucial activities for scientists:
outreach, teaching and research. The number of serious games is increasing
rapidly, in particular citizen science games, games that allow people to
produce and/or analyze scientific data. Interestingly, it is possible to build
a set of rules providing a guideline to create or improve serious games. We
present arguments gathered from our own experience ( Phylo , DocMolecules ,
HiRE-RNA contest and Pangu) as well as examples from the growing literature on
scientific serious games
<i>C-elegans</i> model identifies genetic modifiers of alpha-synuclein inclusion formation during aging
Inclusions in the brain containing alpha-synuclein are the pathological hallmark of Parkinson's disease, but how these inclusions are formed and how this links to disease is poorly understood. We have developed a <i>C-elegans</i> model that makes it possible to monitor, in living animals, the formation of alpha-synuclein inclusions. In worms of old age, inclusions contain aggregated alpha-synuclein, resembling a critical pathological feature. We used genome-wide RNA interference to identify processes involved in inclusion formation, and identified 80 genes that, when knocked down, resulted in a premature increase in the number of inclusions. Quality control and vesicle-trafficking genes expressed in the ER/Golgi complex and vesicular compartments were overrepresented, indicating a specific role for these processes in alpha-synuclein inclusion formation. Suppressors include aging-associated genes, such as sir-2.1/SIRT1 and lagr-1/LASS2. Altogether, our data suggest a link between alpha-synuclein inclusion formation and cellular aging, likely through an endomembrane-related mechanism. The processes and genes identified here present a framework for further study of the disease mechanism and provide candidate susceptibility genes and drug targets for Parkinson's disease and other alpha-synuclein related disorders
Effects of surgery on the mental status of older persons. A meta-analytic review
The data bases of 18 empirical studies were combined into one comprehensive data set and subjected to meta-analysis. The following trends were observed: (1) surgery has a significantly decompensating impact on the mental status of older persons, and the average effect size observed is modest (r = .37); (2) for all mental status measures included in the review (cognition, delirium and affect), effect size appears to be significantly moderated by patient age; (3) patient sex may be predictive of the kind of mental impairment that is most likely to occur within an older surgery population, with women manifesting a greater affinity for delirious and men for cognitive decompensation; (4) most existing research within this domain of study is either purely descriptive or anecdotal: of 46 studies reviewed, only 18, or 39.1% of the total published output, were of sufficient methodologic rigor to allow for scientifically valid effect-size computations. The implications of these findings for future research are discussed
Emotion in responses to the child with ‘additional needs’
The work that is done with children and young people by the practitioners of health, education or social care forms part of their experience of growing up, and can have a profound impact on their future outcomes. Children may find themselves ‘impotent at the hands of powerful others’, particularly where their behaviour causes concern. This paper reports on a key theme from the author's doctoral research, demonstrating the ways that the emotion-laden interactions between practitioners in multi-agency children's services, children and parents, affected the diagnosis, treatment, communication and outcomes for children's well-being, as defined within Every Child Matters. Exploring the emotion within interactions permits a different perspective on ‘need’, and finally, the paper argues for a more careful and emotionally reflective practice from those who work with children
Enteric Neurospheres Are Not Specific to Neural Crest Cultures: Implications for Neural Stem Cell Therapies
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited
Scatter-limited conduction in printed platinum nanofilms
It is demonstrated that thin platinum films may be deposited onto smooth glass substrates using a materials printer and a propriety organometallic ink. Under opti- mised printing and subsequent thermal curing conditions, excellent film adhesion to the substrates was achieved for thicknesses of about 15 nm. The resistivity of the opti- mised films is observed to be a factor of less than 3 higher than pure bulk platinum at 300 K and exhibits a slightly smaller associated thermal coefficient of resistance. The resistivity parameters are found to be insensitive to the gaseous measurement environment which suggests that intercalated carbon regions within the films following the curing process have been largely eliminated. An analysis of the resistivity data indicates that electronic conduction is consistent with enhanced boundary scattering at granular structures that are introduced during multi-pass printing. A minimum electron mean free path of ~18 nm is deduced from the measured film topography. The presented work will find application in biosensor and fuel cell technologies.</p
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