642 research outputs found
Transformation of Peptides into Non-Peptides. Synthesis of Computer-Generated Enzyme Inhibitors
Vitamin K-dependent carboxylase: Synthesis of an inhibitor of the glutamyl binding site
AbstractLiver microsomes contain a vitamin K and O2-dependent carboxylase that converts peptide-bound glutamyl residues to Îł-carboxyglutamyl residues. The peptide Boc-O-phosphoâSer-O-phosphoâSerâLeu-OMe has now been synthesized. This peptide inhibits the carboxylation of endogenous protein precursors by a detergent-solubilized preparation of the carboxylase and is an apparent competitive inhibitor of the carboxylation of PheâLeuâGluâGluâLeu
X-ray crystallographic structure of a complex between a synthetic protease of human immunodeficiency virus 1 and a substrate-based hydroxyethylamine inhibitor
The structure of a crystal complex of the chemically synthesized protease of human immunodeficiency virus 1 with a heptapeptide-derived inhibitor bound in the active site has been determined. The sequence of the inhibitor JG-365 is Ac-Ser-Leu-Asn-Phe-Ï[CH(OH)CH_2N]-Pro-Ile-Val-OMe; the K_i is 0.24 nM. The hydroxyethylamine moiety, in place of the normal scissile bond of the substrate, is believed to mimic a tetrahedral reaction intermediate. The structure of the complex has been refined to an R factor of 0.146 at 2.4-Ă
resolution by using restrained least squares with rms deviations in bond lengths of 0.02 Ă
and bond angles of 4. The bound inhibitor diastereomer has the S configuration at the hydroxyethylamine chiral carbon, and the hydroxyl group is positioned between the active site aspartate carboxyl groups within hydrogen bonding distance. Comparison of this structure with a reduced peptide bond inhibitor-protease complex indicates that these contacts confer the exceptional binding strength of JG-365
Patients with Diabetes and Significant Epicardial Coronary Artery Disease have Increased Systolic Left Ventricular Apical Rotation and Rotation Rate at Rest
Objective
The purpose of this study was to determine whether resting myocardial deformation and rotation may be altered in diabetic patients with significant epicardial coronary artery disease (CAD) with normal left ventricular ejection fraction.
Design
A prospective observational study.
Setting
Diagnosis of epicardial CAD in patients with diabetes.
Patients and Methods
Eighty-four patients with diabetes suspected of epicardial CAD scheduled for cardiac catheterization had a resting echocardiogram performed prior to their procedure. Echocardiographic measurements were compared between patients with and without significant epicardial CAD as determined by cardiac catheterization.
Main Outcome Measures
Measurement of longitudinal strain, strain rate, apical rotation, and rotation rate, using speckle tracking echocardiography.
Results
Eighty-four patients were studied, 39 (46.4%) of whom had significant epicardial CAD. Global peak systolic apical rotation was significantly increased (14.9 ± 5.1 vs. 11.0 ± 4.8 degrees, P < 0.001) in patients with epicardial CAD along with faster peak systolic apical rotation rate (90.4 ± 29 vs. 68.1 ± 22.2 degrees/sec, P < 0.001). These findings were further confirmed through multivariate logistic regression analysis (global peak systolic apical rotation OR = 1.17, P = 0.004 and peak systolic apical rotation rate OR = 1.05, P < 0.001).
Conclusions
Patients with diabetes with significant epicardial CAD and normal LVEF exhibit an increase in peak systolic apical counterclockwise rotation and rotation rate detected by echocardiography, suggesting that significant epicardial CAD and its associated myocardial effects in patients with diabetes may be detected noninvasively at rest
Neural circuitry engaged during unsuccessful motor inhibition in pediatric bipolar disorder
Objective: Deficits in motor inhibition may contribute to impulsivity and irritability in children with bipolar disorder (BPD). Therefore, studies of the neural circuitry engaged during failed motor inhibition in pediatric BPD may contribute to our understanding of the pathophysiology of the illness. We tested the hypothesis that children with BPD and controls would differ in ventral prefrontal cortex (vPFC), striatal, and anterior cingulate activation during unsuccessful motor inhibition. We also compared activation in medicated vs. unmedicated children with BPD, and in children with BPD and ADHD (BPD+ADHD) vs. those with BPD but without ADHD (BPD-ADHD).
Method: Event-related fMRI study comparing neural activation in children with BPD and controls while they performed a motor inhibition task. The sample included 26 children with BPD (13 unmedicated, 15 with ADHD) and 17 age, gender, and IQ matched controls. Results: On failed inhibitory trials, controls showed greater bilateral striatal and right vPFC activation than did patients. While our findings were somewhat more prominent in unmedicated than medicated, patients, and in BPD+ADHD than BPD-ADHD, the findings did not differ significantly (?) among these subgroups of children with BPD.
Conclusions: Compared to controls, children with BPD may have deficits in their ability to engage striatal structures and right vPFC during unsuccessful inhibition. (this reads confusingly to meâtheyâre deficient in their capacity to engage structures when theyâre behaviorally unsuccessful? Perhaps reword?) Further research is needed to determine whether these deficits play a role in the emotional and behavioral dysregulation characteristic of BPD
Characterisation of the safety profile of evobrutinib in over 1000 patients from phase II clinical trials in multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus: an integrated safety analysis
Immunology; Multiple sclerosis; RheumatologyInmunologĂa; Esclerosis mĂșltiple; ReumatologĂaImmunologia; Esclerosi mĂșltiple; ReumatologiaObjective Analyse the integrated safety profile of evobrutinib, a Brutonâs tyrosine kinase inhibitor (BTKi), using pooled data from multiple sclerosis (MS), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) trials.
Methods Phase II, randomised, double-blind, placebo-controlled trial data were analysed (N=1083; MS: n=213, 48 weeks (W); RA: n=390, 12W; SLE: n=480, 52W). The analysis included all patients who received â„1âdose of evobrutinib (25âmg or 75âmg once daily, or 50âmg or 75âmgtwice daily) or placebo. Descriptive statistics and exposure-adjusted incidence rates (EAIR) were used to report treatment-emergent adverse events (TEAEs).
Results Data from 1083 patients were pooled: evobrutinib, n=861; placebo, n=271 (sum >1083âdue to MS trial design: n=49 received both placebo (W0â24) and evobrutinib 25âmg (W25â48)); median follow-up time (pt-years): evobrutinib, 0.501; placebo, 0.463. Across indications, the proportion of patients with TEAEs and the EAIR were similar for evobrutinib and placebo (66.2% (247.6 events/100 pt-years) vs 62.4% (261.4 events/100 pt-years)). By indication, the EAIR (events/100 pt-years) of TEAEs for evobrutinib versus placebo were: MS: 119.7 vs 148.3; RA: 331.8 vs 306.8; SLE: 343.0 vs 302.1. Two fatal events occurred (in SLE). The serious infections EAIR was 2.7 and 2.1 events/100 pt-years for evobrutinib and placebo. For previously reported BTKi-class effects, the EAIR of transient elevated alanine aminotransferase/aspartate aminotransferase TEAEs (events/100 pt-years) with evobrutinib versus placebo was 4.8 vs 2.8/3.5 vs 0.7, respectively. IgG levels were similar in evobrutinib/placebo-treated patients.
Conclusions This is the first BTKi-integrated safety analysis that includes patients with MS. Overall, evobrutinib treatment (all doses) was generally well tolerated across indications.The trial was sponsored by Merck Healthcare KGaA (CrossRef Funder ID: 10.13039/100009945)
Neural Circuitry Engaged During Unsuccessful Motor Inhibition in Pediatric Bipolar Disorder
A Wireless Multi-Channel Recording System for Freely Behaving Mice and Rats
To understand the neural basis of behavior, it is necessary to record brain activity in freely moving animals. Advances in implantable multi-electrode array technology have enabled researchers to record the activity of neuronal ensembles from multiple brain regions. The full potential of this approach is currently limited by reliance on cable tethers, with bundles of wires connecting the implanted electrodes to the data acquisition system while impeding the natural behavior of the animal. To overcome these limitations, here we introduce a multi-channel wireless headstage system designed for small animals such as rats and mice. A variety of single unit and local field potential signals were recorded from the dorsal striatum and substantia nigra in mice and the ventral striatum and prefrontal cortex simultaneously in rats. This wireless system could be interfaced with commercially available data acquisition systems, and the signals obtained were comparable in quality to those acquired using cable tethers. On account of its small size, light weight, and rechargeable battery, this wireless headstage system is suitable for studying the neural basis of natural behavior, eliminating the need for wires, commutators, and other limitations associated with traditional tethered recording systems
Baryon Acoustic Oscillations in the Ly{\alpha} forest of BOSS DR11 quasars
We report a detection of the baryon acoustic oscillation (BAO) feature in the
flux-correlation function of the Ly{\alpha} forest of high-redshift quasars
with a statistical significance of five standard deviations. The study uses
137,562 quasars in the redshift range from the Data Release
11 (DR11) of the Baryon Oscillation Spectroscopic Survey (BOSS) of SDSS-III.
This sample contains three times the number of quasars used in previous
studies. The measured position of the BAO peak determines the angular distance,
and expansion rate, , both on a scale set by the sound
horizon at the drag epoch, . We find
and
where . The optimal
combination, is determined with a precision of
. For the value , consistent with the CMB power
spectrum measured by Planck, we find
and . Tests with mock
catalogs and variations of our analysis procedure have revealed no systematic
uncertainties comparable to our statistical errors. Our results agree with the
previously reported BAO measurement at the same redshift using the
quasar-Ly{\alpha} forest cross-correlation. The auto-correlation and
cross-correlation approaches are complementary because of the quite different
impact of redshift-space distortion on the two measurements. The combined
constraints from the two correlation functions imply values of and
that are, respectively, 7% low and 7% high compared to the
predictions of a flat CDM cosmological model with the best-fit Planck
parameters. With our estimated statistical errors, the significance of this
discrepancy is .Comment: Accepted for publication in A&A. 17 pages, 18 figure
Survival following gamma knife radiosurgery for brain metastasis from breast cancer
BACKGROUND: Breast cancer is the second most common cause of brain metastases in the United States. Although breast cancer induced brain metastases represent an incurable condition, some patients experience prolonged survival. In this retrospective study, we examine a cohort of patients with brain metastases from breast cancer treated with Gamma Knife stereotactic radiosurgery to identify factors that predict better outcomes. METHODS: A retrospective database of 100 patients treated for brain metastases due to breast cancer via Gamma Knife radiosurgery (GKS) from July 1998 through March 2009 was reviewed. Patients who received radiosurgery as sole treatment, as a planned boost after whole brain radiotherapy or surgical resection, or as salvage after prior whole brain radiation therapy (WBRT) or surgical resection were included. Prognostic factors identified to be significant for survival in previous brain metastasis studies were analyzed for significance by univariate and multivariate Cox analysis. RESULTS: Overall, the median brain progression-free survival time was 7.1Â months and the median survival time was 12.3Â months. No prognostic variables were significant for brain progression-free survival. For patients treated with a planned GKS after WBRT, GKS as sole treatment, GKS salvage after WBRT, GKS boost after surgery, or GKS for surgical salvage the median survival times (MSTs) were as follows: 12.2Â months, 12.4Â months, 9.5Â months, 27.6Â months and 33.4Â months respectively. Differences between the groups were not significant (pâ=â0.06); however, GKS boost after surgery and GKS for salvage after surgery did have a trend toward better overall survival. The MST for patients of age <65Â years was 14.5Â months, compared to age â„65 which was 7.7Â months (pâ=â0.06) and remained a significant prognostic factor for overall survival on multivariate analysis. The MST for patients with a single lesion was 16.9Â months, not significantly different than the MST of 14.5Â months for patients with 2â3 lesions. However patients with >3 lesions had a MST of 5.9Â months, which was significantly worse. Breast cancer subtype as approximated by biomarkers and KPS were not significant predictors of overall survival and stage at initial diagnosis was inversely associated with survival. CONCLUSION: Stereotactic radiosurgery offers good local control and prolonged survival in selected patients. Age and number of lesions are strong predictors of overall survival
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