1,490 research outputs found
Reliable protein folding on non-funneled energy landscapes: the free energy reaction path
A theoretical framework is developed to study the dynamics of protein
folding. The key insight is that the search for the native protein conformation
is influenced by the rate r at which external parameters, such as temperature,
chemical denaturant or pH, are adjusted to induce folding. A theory based on
this insight predicts that (1) proteins with non-funneled energy landscapes can
fold reliably to their native state, (2) reliable folding can occur as an
equilibrium or out-of-equilibrium process, and (3) reliable folding only occurs
when the rate r is below a limiting value, which can be calculated from
measurements of the free energy. We test these predictions against numerical
simulations of model proteins with a single energy scale.Comment: 13 pages, 9 figure
Functionalisation of bolaamphiphiles with mononuclear bis(2,2'-bipyridyl)ruthenium(II) complexes for application in self assembled monolayers
A novel ruthenium(II) polypyridyl complex connected competently to a bolaamphiphile, containing amide linkages to provide rigidity via hydrogen bonding in the monolayer, has been prepared. The ruthenium(II) complexes of this ligand and of the intermediates in the synthesis were prepared by modification of the coordinated ligands, demonstrating the synthetic versatility and robustness of this family of complexes. All ruthenium complexes were characterised by electrochemical and spectroscopic techniques and were found to have similar properties to the parent complex [Ru(bipy)[3]][2][+], and remain versatile photosensitisers, with well-defined properties, despite extensive substitution of the bipy ligand
Patterning N-type and S-type neuroblastoma cells with Pluronic F108 and ECM proteins
Influencing cell shape using micropatterned substrates affects cell behaviors, such as proliferation and apoptosis. Cell shape may also affect these behaviors in human neuroblastoma (NBL) cancer, but to date, no substrate design has effectively patterned multiple clinically important human NBL lines. In this study, we investigated whether Pluronic F108 was an effective antiadhesive coating for human NBL cells and whether it would localize three NBL lines to adhesive regions of tissue culture plastic or collagen I on substrate patterns. The adhesion and patterning of an S-type line, SH-EP, and two N-type lines, SH-SY5Y and IMR-32, were tested. In adhesion assays, F108 deterred NBL adhesion equally as well as two antiadhesive organofunctional silanes and far better than bovine serum albumin. Patterned stripes of F108 restricted all three human NBL lines to adhesive stripes of tissue culture plastic. We then investigated four schemes of applying collagen and F108 to different regions of a substrate. Contact with collagen obliterates the ability of F108 to deter NBL adhesion, limiting how both materials can be applied to substrates to produce high fidelity NBL patterning. This patterned substrate design should facilitate investigations of the role of cell shape in NBL cell behavior. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69159/1/32485_ftp.pd
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Shorter Disease Duration Is Associated With Higher Rates of Response to Vedolizumab in Patients With Crohn's Disease But Not Ulcerative Colitis.
Background & aimsPatients with Crohn's disease (CD), but not ulcerative colitis (UC), of shorter duration have higher rates of response to tumor necrosis factor (TNF) antagonists than patients with longer disease duration. Little is known about the association between disease duration and response to other biologic agents. We aimed to evaluate response of patients with CD or UC to vedolizumab, stratified by disease duration.MethodsWe analyzed data from a retrospective, multicenter, consortium of patients with CD (n = 650) or UC (n = 437) treated with vedolizumab from May 2014 through December 2016. Using time to event analyses, we compared rates of clinical remission, corticosteroid-free remission (CSFR), and endoscopic remission between patients with early-stage (â€2 years duration) and later-stage (>2 years) CD or UC. We used Cox proportional hazards models to identify factors associated with outcomes.ResultsWithin 6 months initiation of treatment with vedolizumab, significantly higher proportions of patients with early-stage CD, vs later-stage CD, achieved clinical remission (38% vs 23%), CSFR (43% vs 14%), and endoscopic remission (29% vs 13%) (P < .05 for all comparisons). After adjusting for disease-related factors including previous exposure to TNF antagonists, patients with early-stage CD were significantly more likely than patients with later-stage CD to achieve clinical remission (adjusted hazard ratio [aHR], 1.59; 95% CI, 1.02-2.49), CSFR (aHR, 3.39; 95% CI, 1.66-6.92), and endoscopic remission (aHR, 1.90; 95% CI, 1.06-3.39). In contrast, disease duration was not a significant predictor of response among patients with UC.ConclusionsPatients with CD for 2 years or less are significantly more likely to achieve a complete response, CSFR, or endoscopic response to vedolizumab than patients with longer disease duration. Disease duration does not associate with response vedolizumab in patients with UC
Histone methyltransferase PRMT6 plays an oncogenic role of in prostate cancer
Prostate cancer (PCa) is a major cause of morbidity and mortality. Until now the specific role of histone methyltransferases (HMTs) deregulated expression/activity in PCa is poorly understood. Herein we aimed to uncover the potential oncogenic role of PRMT6 in prostate carcinogenesis. PRMT6 overexpression was confirmed in PCa, at transcript and protein level. Stable PRMT6 knockdown in PC-3 cells attenuated malignant phenotype, increasing apoptosis and decreasing cell viability, migration and invasion. PRMT6 silencing was associated with decreased H3R2me2a levels and increased MLL and SMYD3 expression. PRMT6 silencing increased p21, p27 and CD44 and decreased MMP-9 expression and was associated with PI3K/AKT/mTOR downregulation and increased AR signaling pathway. In Sh-PRMT6 cells, AR restored expression might re-sensitized cells to androgen deprivation therapy, impacting in clinical management of castration-resistant PCa (CRPC). PRMT6 plays an oncogenic role in PCa and predicts for more clinically aggressive disease, constituting a potential target for patients with CRPC.This study was funded by research grants from European Communityâs Seventh Framework Programme
â Grant number FP7-HEALTH-F5-2009-241783 and from the Research Center of Portuguese Oncology
Institute of Porto (CI-IPOP 4-2012). IG, FQV and JRC were supported by a FCT-Fundação para a CiĂȘncia e a Tecnologia grants (CI-IPOP-BPD/UID/DTP/00776/2013, SFRH/BD/70564/2010 and SFRH/BD/71293/2010,
respectively).info:eu-repo/semantics/publishedVersio
Does selective intraoperative music reduce pain following abdominal wall reconstruction?:A double-blind randomized controlled trial
Purpose: Although intraoperative music is purported to mitigate postoperative pain after some procedures, its application has never been explored in abdominal wall reconstruction (AWR). We sought to determine whether intraoperative music would decrease early postoperative pain following AWR. Methods: We conducted a placebo-controlled, patient-, surgeon-, and assessor-blinded, randomized controlled trial at a single center between June 2022 and July 2023 including 321 adult patients undergoing open AWR with retromuscular mesh. Patients received noise-canceling headphones and were randomized 1:1 to patient-selected music or silence after induction, stratified by preoperative chronic opioid use. All patients received multimodal pain control. The primary outcome was pain (NRS-11) at 24 ± 3 h. The primary outcome was analyzed by linear regression with pre-specified covariates (chronic opioid use, hernia width, operative time, myofascial release, anxiety disorder diagnosis, and preoperative STAI-6 score). Results: 178 patients were randomized to music, 164 of which were analyzed. 177 were randomized to silence, 157 of which were analyzed. At 24 ± 3 h postoperatively, there was no difference in the primary outcome of NRS-11 scores (5.18 ± 2.62 vs 5.27 ± 2.46, p = 0.75). After adjusting for prespecified covariates, the difference of NRS-11 scores at 24 ± 3 h between the music and silence groups remained insignificant (p = 0.83). There was no difference in NRS-11 or STAI-6 scores at 48 ± 3 and 72 ± 3 h, intraoperative sedation, or postoperative narcotic usage. Conclusion: For patients undergoing AWR, there was no benefit of intraoperative music over routine multimodal pain control for early postoperative pain reduction. Trial registration: ClinicalTrials.gov: NCT05374096.</p
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PATH-38. ROSETTE-FORMING GLIONEURONAL TUMOR IS DEFINED BY FGFR1 ACTIVATING ALTERATIONS WITH FREQUENT ACCOMPANYING PI3K AND MAPK PATHWAY MUTATIONS
Abstract
BACKGROUND
Rosette-forming glioneuronal tumor (RGNT) is an uncommon CNS tumor originally described in the fourth ventricle characterized by a low-grade glial neoplasm admixed with a rosette-forming neurocytic component.
METHODS
We reviewed clinicopathologic features of 42 patients with RGNT. Targeted next-generation sequencing was performed, and genome-wide methylation profiling is underway.
RESULTS
The 20 male and 22 female patients had a mean age of 25 years (range 3â47) at time of diagnosis. Tumors were located within or adjacent to the lateral ventricle (n=16), fourth ventricle (15), third ventricle (9), and spinal cord (2). All 31 tumors assessed to date contained FGFR1 activating alterations, either in-frame gene fusion, kinase domain tandem duplication, or hotspot missense mutation in the kinase domain (p.N546 or p.K656). While 7 of these 31 tumors harbored FGFR1 alterations as the solitary pathogenic event, 24 contained additional pathogenic alterations within PI3-kinase or MAP kinase pathway genes: 5 with additional PIK3CA and NF1 mutations, 4 with PIK3CA mutation, 3 with PIK3R1 mutation (one of which also contained focal RAF1 amplification), 5 with PTPN11 mutation (one with additional PIK3R1 mutation), and 2 with NF1 deletion. The other 5 cases demonstrated anaplastic features including hypercellularity and increased mitotic activity. Among these anaplastic cases, 3 harbored inactivating ATRX mutations and two harbored CDKN2A homozygous deletion, in addition to the FGFR1 alterations plus other PI3-kinase and MAP kinase gene mutations seen in those RGNT without anaplasia.
CONCLUSION
Independent of ventricular location, RGNT is defined by FGFR1 activating mutations or rearrangements, which are frequently accompanied by mutations involving PIK3CA, PIK3R1, PTPN11, NF1, and KRAS. Whereas pilocytic astrocytoma and ganglioglioma are characterized by solitary activating MAP kinase pathway alterations (e.g. BRAF fusion or mutation), RGNT are genetically more complex with dual PI3K-Akt-mTOR and Ras-Raf-MAPK pathway activation. Rare anaplastic examples may show additional ATRX and/or CDKN2A inactivation
Stereoselective Synthesis of the Quettamine Skeleton
A synthesis of the quettamine skeleton 29 is described comprising ring closure
of the diastereomeric phenolic 1-(α-bromobenzyl)-tetrahydroisoquinolines
27a and 27b. In both cases only one diastereomer was obtained. NOE-experiments
confirm Shamma's assignments concerning the stereochemistry.
- Various attemps to cleave the dithiane derivative 5 of an α-amino
ketone in order to obtain the ketone 6 failed on account of the non-bonding
electron pair at the N-atom.
Wir beschreiben die Synthese des Quettamin-GerĂŒstes 29 durch RingschluĂ
der diastereomeren 1-(α-Brombenzyl)-tetrahydroisochinoline 27a and 27b.
In beiden FÀllen resultierte nur ein Diastereomer. NOE-Messungen bestÀtigen
Shamma's Aussagen zur Stereochemie. - Zahlreiche Versuche, das
Dithian-Derivat 5 eines α-Aminoketons zum Keton 6 zu spalten, schlugen
fehl wegen des nichtbindenden Elektronenpaars am Stickstoff
Performance of a Kinetic Inductance Phonon-Mediated Detector at the NEXUS Cryogenic Facility
Microcalorimeters that leverage microwave kinetic inductance detectors to
read out phonon signals in the particle-absorbing target, referred to as
kinetic inductance phonon-mediated (KIPM) detectors, offer an attractive
detector architecture to probe dark matter (DM) down to the fermionic thermal
relic mass limit. A prototype KIPM detector featuring a single aluminum
resonator patterned onto a 1-gram silicon substrate was operated in the NEXUS
low-background facility at Fermilab for characterization and evaluation of this
detector architecture's efficacy for a dark matter search. An energy
calibration was performed by exposing the bare substrate to a pulsed source of
470 nm photons, resulting in a baseline resolution on the energy absorbed by
the phonon sensor of eV, a factor of two better than the current
state-of-the-art, enabled by millisecond-scale quasiparticle lifetimes.
However, due to the sub-percent phonon collection efficiency, the resolution on
energy deposited in the substrate is limited to eV. We
further model the signal pulse shape as a function of device temperature to
extract quasiparticle lifetimes, as well as the observed noise spectra, both of
which impact the baseline resolution of the sensor
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