252 research outputs found
RAD54 family translocases counter genotoxic effects of RAD51 in human tumor cells.
The RAD54 family DNA translocases have several biochemical activities. One activity, demonstrated previously for the budding yeast translocases, is ATPase-dependent disruption of RAD51-dsDNA binding. This activity is thought to promote dissociation of RAD51 from heteroduplex DNA following strand exchange during homologous recombination. In addition, previous experiments in budding yeast have shown that the same activity of Rad54 removes Rad51 from undamaged sites on chromosomes; mutants lacking Rad54 accumulate nonrepair-associated complexes that can block growth and lead to chromosome loss. Here, we show that human RAD54 also promotes the dissociation of RAD51 from dsDNA and not ssDNA. We also show that translocase depletion in tumor cell lines leads to the accumulation of RAD51 on chromosomes, forming complexes that are not associated with markers of DNA damage. We further show that combined depletion of RAD54L and RAD54B and/or artificial induction of RAD51 overexpression blocks replication and promotes chromosome segregation defects. These results support a model in which RAD54L and RAD54B counteract genome-destabilizing effects of direct binding of RAD51 to dsDNA in human tumor cells. Thus, in addition to having genome-stabilizing DNA repair activity, human RAD51 has genome-destabilizing activity when expressed at high levels, as is the case in many human tumors
Crystal Structure of Orthorhombic {bis-[(pyridin-2-yl)methyl](3,5,5,5-tetrachloropentyl)amine-Îș\u3csup\u3e3\u3c/sup\u3e\u3cem\u3eN,N\u27,N\u27\u27\u3c/em\u3e}chloridocopper(II) Perchlorate
In the title compound, [CuCl(C17H19Cl4N3)]ClO4, the CuII ion adopts a distorted square-planar geometry defined by one chloride ligand and the three nitroÂgen atoms from the bisÂ[(pyridin-2-yl)methÂyl](3,5,5,5-tetraÂchloroÂpentÂyl)amine ligand. The perchlorate counter-ion is disordered over three sets of sites with refined occupancies 0.0634â
(17), 0.221â
(16) and 0.145â
(7). In addition, the hetero-scorpionate arm of the bisÂ[(pyridin-2-yl)methÂyl](3,5,5,5-tetraÂchloroÂpentÂyl)amine ligand is disordered over two sets of sites with refined occupancies 0.839â
(2) and 0.161â
(2). In the crystal, weak CuâŻCl interÂactions between symmetry-related molÂecules create a dimerization with a chloride occupying the apical position of the square-pyramidal geometry typical of many copper(II) chloride hetero-scorpionate complexes
Can programme theory be used as a 'translational toolâ to optimise health service delivery in a national early yearsâ initiative in Scotland: a case study
Background
Theory-based evaluation (TBE) approaches are heralded as supporting formative evaluation by facilitating increased use of evaluative findings to guide programme improvement. It is essential that learning from programme implementation is better used to improve delivery and to inform other initiatives, if interventions are to be as effective as they have the potential to be. Nonetheless, few studies describe formative feedback methods, or report direct instrumental use of findings resulting from TBE. This paper uses the case of Scotlandâs, National Health Service, early yearsâ, oral health improvement initiative (Childsmile) to describe the use of TBE as a framework for providing feedback on delivery to programme staff and to assess its impact on programmatic action.<p></p>
Methods
In-depth, semi-structured interviews and focus groups with key stakeholders explored perceived deviations between the Childsmile programme 'as deliveredâ and its Programme Theory (PT). The data was thematically analysed using constant comparative methods. Findings were shared with key programme stakeholders and discussions around likely impact and necessary actions were facilitated by the authors. Documentary review and ongoing observations of programme meetings were undertaken to assess the extent to which learning was acted upon.<p></p>
Results
On the whole, the activities documented in Childsmileâs PT were implemented as intended. This paper purposefully focuses on those activities where variation in delivery was evident. Differences resulted from the stage of roll-out reached and the flexibility given to individual NHS boards to tailor local implementation. Some adaptations were thought to have diverged from the central features of Childsmileâs PT, to the extent that there was a risk to achieving outcomes. The methods employed prompted national service improvement action, and proposals for local action by individual NHS boards to address this.<p></p>
Conclusions
The TBE approach provided a platform, to direct attention to areas of risk within a national health initiative, and to agree which intervention components were 'coreâ to its hypothesised success. The study demonstrates that PT can be used as a 'translational toolâ to facilitate instrumental use of evaluative findings to optimise implementation within a complex health improvement programme.<p></p>
Normalizing Deviants: Notes on the De-Stigma Trend
This article explores destigmatization discourses in the United States in the early 21st century, as social and political strategies and as narrative social movements unto themselves. We argue that the first decades of the new century see a trend of marginalized actors across many categories, including queer marriage, drugs, (discreditable) mental illness and (discredited) other areas of identity and disability, make narrative attempts to neutralize their âdeviantâ identities. We argue that de-stigmatization has occurred through the successful use of medicalization and assimilation framing of de-stigma discourses. Assimilationist frames increase âliberalâ emphasis on actionable outcomes of de-stigma, like cultural access (i.e. inclusion, visibility, representation), and legal justice for marginalized people. Some assimilationist discourse endeavors to situate stigmatized identities inside of conformist frames, while (fewer and less visible) others resist dominant frames of acceptability. Contested assimilation and radical leftist de-stigmatization, as well as re-stigma discourses are also discussed
Inhaled Nanoparticles Accumulate at Sites of Vascular Disease
The development of engineered nanomaterials is growing exponentially, despite concerns over their potential similarities to environmental nanoparticles that are associated with significant cardiorespiratory morbidity and mortality. The mechanisms through which inhalation of nanoparticles could trigger acute cardiovascular events are emerging, but a fundamental unanswered question remains: Do inhaled nanoparticles translocate from the lung in man and directly contribute to the pathogenesis of cardiovascular disease? In complementary clinical and experimental studies, we used gold nanoparticles to evaluate particle translocation, permitting detection by high-resolution inductively coupled mass spectrometry and Raman microscopy. Healthy volunteers were exposed to nanoparticles by acute inhalation, followed by repeated sampling of blood and urine. Gold was detected in the blood and urine within 15 min to 24 h after exposure, and was still present 3 months after exposure. Levels were greater following inhalation of 5 nm (primary diameter) particles compared to 30 nm particles. Studies in mice demonstrated the accumulation in the blood and liver following pulmonary exposure to a broader size range of gold nanoparticles (2-200 nm primary diameter), with translocation markedly greater for particles <10 nm diameter. Gold nanoparticles preferentially accumulated in inflammation-rich vascular lesions of fat-fed apolipoproteinE-deficient mice. Furthermore, following inhalation, gold particles could be detected in surgical specimens of carotid artery disease from patients at risk of stroke. Translocation of inhaled nanoparticles into the systemic circulation and accumulation at sites of vascular inflammation provides a direct mechanism that can explain the link between environmental nanoparticles and cardiovascular disease and has major implications for risk management in the use of engineered nanomaterials
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
Defects in ERâendosome contacts impact lysosome function in hereditary spastic paraplegia
Contacts between endosomes and the endoplasmic reticulum (ER) promote endosomal tubule fission, but the mechanisms involved and consequences of tubule fission failure are incompletely understood. We found that interaction between the microtubule-severing enzyme spastin and the ESCRT protein IST1 at ERâendosome contacts drives endosomal tubule fission. Failure of fission caused defective sorting of mannose 6-phosphate receptor, with consequently disrupted lysosomal enzyme trafficking and abnormal lysosomal morphology, including in mouse primary neurons and human stem cellâderived neurons. Consistent with a role for ER-mediated endosomal tubule fission in lysosome function, similar lysosomal abnormalities were seen in cellular models lacking the WASH complex component strumpellin or the ER morphogen REEP1. Mutations in spastin, strumpellin, or REEP1 cause hereditary spastic paraplegia (HSP), a disease characterized by axonal degeneration. Our results implicate failure of the ERâendosome contact process in axonopathy and suggest that coupling of ER-mediated endosomal tubule fission to lysosome function links different classes of HSP proteins, previously considered functionally distinct, into a unifying pathway for axonal degeneration.This work was supported by grants to E. Reid: UK Medical Research Council Project Grant (MR/M00046X/1), Wellcome Trust Senior Research Fellowship in Clinical Science (082381), Project Grant from United States Spastic Paraplegia Foundation, Project Grant from Tom Wahlig Stiftung, and Project Grant form UK HSP Family Group. J.R. Edgar is supported by the Wellcome Trust (grant 086598). T. Newton and G. Pearson are supported by the Medical Research Council PhD studentships (G0800117 and MR/K50127X/1). F. Berner was supported by the National Institute for Health Research Biomedical Research Centre at Addenbrooke's Hospital. B. Winner is supported by the Tom Wahlig Advanced Fellowship, the German Federal Ministry of Education and Research (01GQ113), the Bavarian Ministry of Education and Culture, Sciences and Arts in the framework of the Bavarian Molecular Biosystems Research Network and ForIPS, and the Interdisciplinary Centre for Clinical Research (University Hospital of Erlangen, N3 and F3). Cambridge Institute for Medical Research is supported by a Wellcome Trust Strategic Award (100140) and Equipment Grant (093026)
Final Targeting Strategy for the SDSS-IV APOGEE-2N Survey
APOGEE-2 is a dual-hemisphere, near-infrared (NIR), spectroscopic survey with
the goal of producing a chemo-dynamical mapping of the Milky Way Galaxy. The
targeting for APOGEE-2 is complex and has evolved with time. In this paper, we
present the updates and additions to the initial targeting strategy for
APOGEE-2N presented in Zasowski et al. (2017). These modifications come in two
implementation modes: (i) "Ancillary Science Programs" competitively awarded to
SDSS-IV PIs through proposal calls in 2015 and 2017 for the pursuit of new
scientific avenues outside the main survey, and (ii) an effective 1.5-year
expansion of the survey, known as the Bright Time Extension, made possible
through accrued efficiency gains over the first years of the APOGEE-2N project.
For the 23 distinct ancillary programs, we provide descriptions of the
scientific aims, target selection, and how to identify these targets within the
APOGEE-2 sample. The Bright Time Extension permitted changes to the main survey
strategy, the inclusion of new programs in response to scientific discoveries
or to exploit major new datasets not available at the outset of the survey
design, and expansions of existing programs to enhance their scientific success
and reach. After describing the motivations, implementation, and assessment of
these programs, we also leave a summary of lessons learned from nearly a decade
of APOGEE-1 and APOGEE-2 survey operations. A companion paper, Santana et al.
(submitted), provides a complementary presentation of targeting modifications
relevant to APOGEE-2 operations in the Southern Hemisphere.Comment: 59 pages; 11 Figures; 7 Tables; 2 Appendices; Submitted to Journal
and Under Review; Posting to accompany papers using the SDSS-IV/APOGEE-2 Data
Release 17 scheduled for December 202
Dipeptidyl peptidase-1 inhibition in patients hospitalised with COVID-19:a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial
This study was funded by an investigator-initiated research grant from Insmed (Bridgewater, NJ, USA). The authors acknowledge the funding and logistical support from the UK National Institute for Health and Care Research.Background: Neutrophil serine proteases are involved in the pathogenesis of COVID-19 and increased serine protease activity has been reported in severe and fatal infection. We investigated whether brensocatib, an inhibitor of dipeptidyl peptidase-1 (DPP-1; an enzyme responsible for the activation of neutrophil serine proteases), would improve outcomes in patients hospitalised with COVID-19. Methods: In a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial, across 14 hospitals in the UK, patients aged 16 years and older who were hospitalised with COVID-19 and had at least one risk factor for severe disease were randomly assigned 1:1, within 96 h of hospital admission, to once-daily brensocatib 25 mg or placebo orally for 28 days. Patients were randomly assigned via a central web-based randomisation system (TruST). Randomisation was stratified by site and age (65 years or â„65 years), and within each stratum, blocks were of random sizes of two, four, or six patients. Participants in both groups continued to receive other therapies required to manage their condition. Participants, study staff, and investigators were masked to the study assignment. The primary outcome was the 7-point WHO ordinal scale for clinical status at day 29 after random assignment. The intention-to-treat population included all patients who were randomly assigned and met the enrolment criteria. The safety population included all participants who received at least one dose of study medication. This study was registered with the ISRCTN registry, ISRCTN30564012. Findings: Between June 5, 2020, and Jan 25, 2021, 406 patients were randomly assigned to brensocatib or placebo; 192 (47·3%) to the brensocatib group and 214 (52·7%) to the placebo group. Two participants were excluded after being randomly assigned in the brensocatib group (214 patients included in the placebo group and 190 included in the brensocatib group in the intention-to-treat population). Primary outcome data was unavailable for six patients (three in the brensocatib group and three in the placebo group). Patients in the brensocatib group had worse clinical status at day 29 after being randomly assigned than those in the placebo group (adjusted odds ratio 0·72 [95% CI 0·57-0·92]). Prespecified subgroup analyses of the primary outcome supported the primary results. 185 participants reported at least one adverse event; 99 (46%) in the placebo group and 86 (45%) in the brensocatib group. The most common adverse events were gastrointestinal disorders and infections. One death in the placebo group was judged as possibly related to study drug. Interpretation: Brensocatib treatment did not improve clinical status at day 29 in patients hospitalised with COVID-19.Publisher PDFPeer reviewe
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