399 research outputs found
Action of serotonin (5-hydroxytryptamine) on cyclic nucleotides in glomeruli of rat renal cortex
Action of serotonin (5-hydroxytryptamine) on cyclic nucleotides in glomeruli of rat renal cortex. Serotonin (5-hydroxytryptamine) is known to influence glomerular function and may have an important role in the pathogenesis of glomerulopathies. Because serotonin acts in nonrenal tissues through mediation of cyclic nucleotides, we investigated in vitro its effect on cAMP and cyclic guanosine monophosphate (cGMP) in tissue slices and isolated glomeruli from rat kidney. Serotonin increased cAMP 161 ± 35% but not cGMP in renal cortex; it had no effect on cyclic nucleotides in medulla and papilla. In isolated glomeruli, serotonin elicited a dose-dependent (in the range of 10â7 to 10â4M) increase in cAMP; the maximum increase over basal values was 376 ± 45%. Serotonin increased cAMP either in the presence or in the absence of a cAMP phosphodiesterase inhibitor. In tubular fraction, serotonin elevated cAMP to a much lesser degree (82 ± 15%). Neither in glomeruli nor in tubules did cGMP concentrations change in response to serotonin, but carbamylcholine, a known cGMP agonist, significantly increased cGMP concentrations. The increase in cAMP in response to serotonin was blocked (>85% inhibition) by equimolar concentrations of serotonin antagonists methysergide and cinanserine. Results of this study demonstrate that interaction of serotonin with receptors in the kidney, particularly in the glomeruli, cause a striking increase in cAMP concentrations without detectable changes in cGMP concentrations. These findings suggest that serotonin, either synthesized in the kidney or released locally from platelets aggregated in glomeruli (for example, in association with immu-nopathologic injury) may exert or modulate its physiologic or pathologic effects via mediation of cAMP.Action de la sĂ©rotonine (5-hydroxytryptamine) sur les nuclĂ©otides cycliques des glomĂ©rules du cortex rĂ©nal du rat. Il est connu que la sĂ©rotonine (5-hydroxytryptamine) influence la fonction glomĂ©rulaire et peut avoir un rĂŽle important dans la pathogĂ©nie des glomĂ©rulopathies. Puisque la sĂ©rotonine agit sur d'autres tissus que le rein par l'intermĂ©diaire des nuclĂ©otides cycliques, nous avons Ă©tudiĂ© son effet in vitro sur le contenu en cAMP et cGMP des tranches de rein et des glomĂ©rules isolĂ©s du rein de rat. La sĂ©rotonine augmente cAMP 161 ± 35%, mais pas cGMP du cortex rĂ©nal. Elle n'a pas d'effet sur les nuclĂ©otides cycliques de la mĂ©dullaire et de la papille. Dans les glomĂ©rules isolĂ©s la sĂ©rontonine dĂ©termine une augmentation de cAMP dose dĂ©pendante (de 10â7 Ă 10â4M), l'augmentation maximale est de 376 ± 45% par rapport Ă la valeur basale. La sĂ©rotonine augmente cAMP aussi bien en prĂ©sence qu'en l'absence d'inhibiteur de la cAMP phosphodiestĂ©rase. Dans les fractions tabulaires la sĂ©rotonine n'augmente cAMP qu'Ă un moindre degrĂ© (82 ± 15%). La sĂ©rotonine n'augmente cGMP ni dans les glomĂ©rules ni dans les tubules mais la carbamylcholine, un agoniste connu de cGMP augmente celui-ci significativement. L'augmentation de cAMP en rĂ©ponse Ă la sĂ©rotonine est bloquĂ©e (inhibition supĂ©rieure Ă 85%) par des concentrations Ă©quimolaires des antagonistes mĂ©thysergide et cinansĂ©rine. Les rĂ©sultats de ce travail dĂ©montrent que l'interaction de la sĂ©rotonine avec les rĂ©cepteurs rĂ©naux, particuliĂšrement glomĂ©rulaires, dĂ©termine une augmentation importante de cAMP sans modification dĂ©tĂ©ctable de cGMP. Ces constatations suggĂšrent que la sĂ©rotonine, qu'elle soit synthĂ©tisĂ©e dans le rein ou libĂ©rĂ©e localement par des aggrĂ©gats plaquettaires formĂ©s dans les glomĂ©rules (c'est Ă dire en association avec une lĂ©sion immunopathologique), peut exercer ou moduler ses effets physiologiques ou pathologiques par l'intermĂ©diaire de cAMP
RNA polymerase is poised for activation across the genome
Regulation of gene expression is integral to the development and survival of all organisms. Transcription begins with the assembly of a pre-initiation complex at the gene promoter, followed by initiation of RNA synthesis and the transition to productive elongation. In many cases, recruitment of RNA polymerase II (Pol II) to a promoter is necessary and sufficient for activation of genes. However, there are a few notable exceptions to this paradigm, including heat shock genes and several proto-oncogenes, whose expression is attenuated by regulated stalling of polymerase elongation within the promoter-proximal region. To determine the importance of polymerase stalling for transcription regulation, we carried out a genome-wide search for Drosophila melanogaster genes with Pol II stalled within the promoter-proximal region. Our data show that stalling is widespread, occurring at hundreds of genes that respond to stimuli and developmental signals. This finding indicates a role for regulation of polymerase elongation in the transcriptional responses to dynamic environmental and developmental cues
Sustainability assessment of electrokinetic bioremediation compared with alternative remediation options for a petroleum release site
Sustainable management practices can be applied to the remediation of contaminated land to maximise
the economic, environmental and social benefits of the process. The Sustainable Remediation Forum UK
(SuRF-UK) have developed a framework to support the implementation of sustainable practices within
contaminated land management and decision making. This study applies the framework, including
qualitative (Tier 1) and semi-quantitative (Tier 2) sustainability assessments, to a complex site where the
principal contaminant source is unleaded gasoline, giving rise to a dissolved phase BTEX and MTBE
plume. The pathway is groundwater migration through a chalk aquifer and the receptor is a water supply
borehole. A hydraulic containment system (HCS) has been installed to manage the MTBE plume
migration. The options considered to remediate the MTBE source include monitored natural attenuation
(MNA), air sparging/soil vapour extraction (AS/SVE), pump and treat (PT) and electrokinetic-enhanced
bioremediation (EK-BIO). A sustainability indictor set from the SuRF-UK framework, including priority
indicator categories selected during a stakeholder engagement workshop, was used to frame the assessments.
At Tier 1 the options are ranked based on qualitative supporting information, whereas in Tier
2 a multi-criteria analysis is applied. Furthermore, the multi-criteria analysis was refined for scenarios
where photovoltaics (PVs) are included and amendments are excluded from the EK-BIO option. Overall,
the analysis identified AS/SVE and EK-BIO as more sustainable remediation options at this site than either
PT or MNA. The wider implications of this study include: (1) an appraisal of the management decision
from each Tier of the assessment with the aim to highlight areas for time and cost savings for similar
assessments in the future; (2) the observation that EK-BIO performed well against key indicator categories
compared to the other intensive treatments; and (3) introducing methods to improve the sustainability
of the EK-BIO treatment design (such as PVs) did not have a significant effect in this instance
Achieving synergy: Linking an internet-based inflammatory bowel disease cohort to a community-based inception cohort and multicentered cohort in inflammatory bowel disease
Background: Traditional cohort studies are important contributors to our understanding of inflammatory bowel diseases, but they are labor intensive and often do not focus on patient-reported outcomes. Internet-based studies provide new opportunities to study patient-reported outcomes and can be efficiently implemented and scaled. If a traditional cohort study was linked to an Internet-based study, both studies could benefit from added synergy. Existing cohort studies provide an opportunity to develop and test processes for cohort linkage. The Crohn's and Colitis Foundation of America's (CCFA) Partners study is an Internet-based cohort of more than 14,000 participants. The Ocean State Crohn's and Colitis Area Registry (OSCCAR) is an inception cohort. The Sinai-Helmsley Alliance for Research Excellence (SHARE) is a multicentered cohort of inflammatory bowel disease patients. Both the later cohorts include medical record abstraction, patient surveys, and biospecimen collection. Objective: Given the complementary nature of these existing cohorts, we sought to corecruit and link data. Methods: Eligible OSCCAR and SHARE participants were invited to join the CCFA Partners study and provide consent for data sharing between the 2 cohorts. After informed consent, participants were directed to the CCFA Partners website to complete enrollment and a baseline Web-based survey. Participants were linked across the 2 cohorts by the matching of an email address. We compared demographic and clinical characteristics between OSCCAR and SHARE participants who did and did not enroll in CCFA Partners and the data linkage. Results: Of 408 participants in the OSCCAR cohort, 320 were eligible for participation in the CCFA Partners cohort. Of these participants, 243 consented to participation; however, only 44 enrolled in CCFA Partners and completed the linkage. OSCCAR participants who enrolled in CCFA Partners were better educated (17% with doctoral degrees) than those who did not (3% with doctoral degrees, P=.01). In the SHARE cohort, 436 participants enrolled and linked to the Partners cohort. More women (60% vs 50%) linked and those who linked were predominantly white (96%; P<.01). Crohn's disease patients who linked had lower mean scores on the Harvey-Bradshaw Index (3.6 vs 4.4, P<.01). Ulcerative colitis patients who linked had less extensive disease than those who did not link (45% vs 60%, P<.01). Conclusions: Linkage of CCFA Partners with cohorts such as OSCCAR and SHARE may be a cost-effective way to expand the infrastructure for clinical outcomes and translational research. Although linkage is feasible from a technical, legal, and regulatory perspective, participant willingness appears to be a limiting factor. Overcoming this barrier will be needed to generate meaningful sample sizes to conduct studies of biomarkers, natural history, and clinical effectiveness using linked data
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV
The Lambda(b) differential production cross section and the cross section
ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum
pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7
TeV using data collected by the CMS experiment at the LHC. The measurements are
based on Lambda(b) decays reconstructed in the exclusive final state J/Psi
Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and
Lambda to proton pion, using a data sample corresponding to an integrated
luminosity of 1.9 inverse femtobarns. The product of the cross section times
the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls
faster than that of b mesons. The measured value of the cross section times the
branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06
+/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for
anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are
statistical and systematic, respectively.Comment: Submitted to Physics Letters
Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV
A search is presented for physics beyond the standard model (BSM) in final
states with a pair of opposite-sign isolated leptons accompanied by jets and
missing transverse energy. The search uses LHC data recorded at a
center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to
an integrated luminosity of approximately 5 inverse femtobarns. Two
complementary search strategies are employed. The first probes models with a
specific dilepton production mechanism that leads to a characteristic kinematic
edge in the dilepton mass distribution. The second strategy probes models of
dilepton production with heavy, colored objects that decay to final states
including invisible particles, leading to very large hadronic activity and
missing transverse energy. No evidence for an event yield in excess of the
standard model expectations is found. Upper limits on the BSM contributions to
the signal regions are deduced from the results, which are used to exclude a
region of the parameter space of the constrained minimal supersymmetric
extension of the standard model. Additional information related to detector
efficiencies and response is provided to allow testing specific models of BSM
physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO
Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV
Isolated photon production is measured in proton-proton and lead-lead
collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the
pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80
GeV with the CMS detector at the LHC. The measured ET spectra are found to be
in good agreement with next-to-leading-order perturbative QCD predictions. The
ratio of PbPb to pp isolated photon ET-differential yields, scaled by the
number of incoherent nucleon-nucleon collisions, is consistent with unity for
all PbPb reaction centralities.Comment: Submitted to Physics Letters
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Live-cell three-dimensional single-molecule tracking reveals modulation of enhancer dynamics by NuRD
To understand how the nucleosome remodeling and deacetylase (NuRD) complex regulates enhancers and enhancerâpromoter interactions, we have developed an approach to segment and extract key biophysical parameters from live-cell three-dimensional single-molecule trajectories. Unexpectedly, this has revealed that NuRD binds to chromatin for minutes, decompacts chromatin structure and increases enhancer dynamics. We also uncovered a rare fast-diffusing state of enhancers and found that NuRD restricts the time spent in this state. Hi-C and Cut&Run experiments revealed that NuRD modulates enhancerâpromoter interactions in active chromatin, allowing them to contact each other over longer distances. Furthermore, NuRD leads to a marked redistribution of CTCF and, in particular, cohesin. We propose that NuRD promotes a decondensed chromatin environment, where enhancers and promoters can contact each other over longer distances, and where the resetting of enhancerâpromoter interactions brought about by the fast decondensed chromatin motions is reduced, leading to more stable, long-lived enhancerâpromoter relationships
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