728 research outputs found

    Domain-based small molecule binding site annotation

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    BACKGROUND: Accurate small molecule binding site information for a protein can facilitate studies in drug docking, drug discovery and function prediction, but small molecule binding site protein sequence annotation is sparse. The Small Molecule Interaction Database (SMID), a database of protein domain-small molecule interactions, was created using structural data from the Protein Data Bank (PDB). More importantly it provides a means to predict small molecule binding sites on proteins with a known or unknown structure and unlike prior approaches, removes large numbers of false positive hits arising from transitive alignment errors, non-biologically significant small molecules and crystallographic conditions that overpredict ion binding sites. DESCRIPTION: Using a set of co-crystallized protein-small molecule structures as a starting point, SMID interactions were generated by identifying protein domains that bind to small molecules, using NCBI's Reverse Position Specific BLAST (RPS-BLAST) algorithm. SMID records are available for viewing at . The SMID-BLAST tool provides accurate transitive annotation of small-molecule binding sites for proteins not found in the PDB. Given a protein sequence, SMID-BLAST identifies domains using RPS-BLAST and then lists potential small molecule ligands based on SMID records, as well as their aligned binding sites. A heuristic ligand score is calculated based on E-value, ligand residue identity and domain entropy to assign a level of confidence to hits found. SMID-BLAST predictions were validated against a set of 793 experimental small molecule interactions from the PDB, of which 472 (60%) of predicted interactions identically matched the experimental small molecule and of these, 344 had greater than 80% of the binding site residues correctly identified. Further, we estimate that 45% of predictions which were not observed in the PDB validation set may be true positives. CONCLUSION: By focusing on protein domain-small molecule interactions, SMID is able to cluster similar interactions and detect subtle binding patterns that would not otherwise be obvious. Using SMID-BLAST, small molecule targets can be predicted for any protein sequence, with the only limitation being that the small molecule must exist in the PDB. Validation results and specific examples within illustrate that SMID-BLAST has a high degree of accuracy in terms of predicting both the small molecule ligand and binding site residue positions for a query protein

    Volumetric comparison of hippocampal subfields extracted from 4-minute accelerated vs. 8-minute high-resolution T2-weighted 3T MRI scans

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    The hippocampus has been widely studied using neuroimaging, as it plays an important role in memory and learning. However, hippocampal subfield information is difficult to capture by standard magnetic resonance imaging (MRI) techniques. To facilitate morphometric study of hippocampal subfields, ADNI introduced a high resolution (0.4 mm in plane) T2-weighted turbo spin-echo sequence that requires 8 min. With acceleration, the protocol can be acquired in 4 min. We performed a comparative study of hippocampal subfield volumes using standard and accelerated protocols on a Siemens Prisma 3T MRI in an independent sample of older adults that included 10 cognitively normal controls, 9 individuals with subjective cognitive decline, 10 with mild cognitive impairment, and 6 with a clinical diagnosis of Alzheimer’s disease (AD). The Automatic Segmentation of Hippocampal Subfields (ASHS) software was used to segment 9 primary labeled regions including hippocampal subfields and neighboring cortical regions. Intraclass correlation coefficients were computed for reliability tests between 4 and 8 min scans within and across the four groups. Pairwise group analyses were performed, covaried for age, sex and total intracranial volume, to determine whether the patterns of group differences were similar using 4 vs. 8 min scans. The 4 and 8 min protocols, analyzed by ASHS segmentation, yielded similar volumetric estimates for hippocampal subfields as well as comparable patterns of differences between study groups. The accelerated protocol can provide reliable imaging data for investigation of hippocampal subfields in AD-related MRI studies and the decreased scan time may result in less vulnerability to motion

    A personalized Uncertainty Quantification framework for patient survival models: estimating individual uncertainty of patients with metastatic brain tumors in the absence of ground truth

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    TodevelopanovelUncertaintyQuantification (UQ) framework to estimate the uncertainty of patient survival models in the absence of ground truth, we developed and evaluated our approach based on a dataset of 1383 patients treated with stereotactic radiosurgery (SRS) for brain metastases between January 2015 and December 2020. Our motivating hypothesis is that a time-to-event prediction of a test patient on inference is more certain given a higher feature-space-similarity to patients in the training set. Therefore, the uncertainty for a particular patient-of-interest is represented by the concordance index between a patient similarity rank and a prediction similarity rank. Model uncertainty was defined as the increased percentage of the max uncertainty-constrained-AUC compared to the model AUC. We evaluated our method on multiple clinically-relevant endpoints, including time to intracranial progression (ICP), progression-free survival (PFS) after SRS, overall survival (OS), and time to ICP and/or death (ICPD), on a variety of both statistical and non-statistical models, including CoxPH, conditional survival forest (CSF), and neural multi-task linear regression (NMTLR). Our results show that all models had the lowest uncertainty on ICP (2.21%) and the highest uncertainty (17.28%) on ICPD. OS models demonstrated high variation in uncertainty performance, where NMTLR had the lowest uncertainty(1.96%)and CSF had the highest uncertainty (14.29%). In conclusion, our method can estimate the uncertainty of individual patient survival modeling results. As expected, our data empirically demonstrate that as model uncertainty measured via our technique increases, the similarity between a feature-space and its predicted outcome decreases

    Perspectives on Astrophysics Based on Atomic, Molecular, and Optical (AMO) Techniques

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    About two generations ago, a large part of AMO science was dominated by experimental high energy collision studies and perturbative theoretical methods. Since then, AMO science has undergone a transition and is now dominated by quantum, ultracold, and ultrafast studies. But in the process, the field has passed over the complexity that lies between these two extremes. Most of the Universe resides in this intermediate region. We put forward that the next frontier for AMO science is to explore the AMO complexity that describes most of the Cosmos.Comment: White paper submission to the Decadal Assessment and Outlook Report on Atomic, Molecular, and Optical (AMO) Science (AMO 2020

    UV/Vis+ Photochemistry Database : Structure, Content and Applications

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    Acknowledgments This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. However, the authors are indebted to those colleagues who support us in maintaining the database through the provision of spectral and other photochemical data and information. The National Center for Atmospheric Research is operated by the University Coporation for Atmopsheric Research, under the sponsorship of the National Science Foundation. Disclaimer: The views expressed in this paper are those of the authors and do not necessarily represent the views or policies of the U.S.EPA. Mention of trade names or products does not convey and should not be interpreted as conveying official U.S. EPA approval, endorsement, or recommendation.Peer reviewedPublisher PD

    ACR appropriateness criteria® nasal cavity and paranasal sinus cancers

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    The American College of Radiology (ACR) Appropriateness Criteria are evidence‐based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer‐reviewed journals and the application of well‐established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment. Here, we present the Appropriateness Criteria for cancers arising in the nasal cavity and paranasal sinuses (maxillary, sphenoid, and ethmoid sinuses). This includes clinical presentation, prognostic factors, principles of management, and treatment outcomes. Controversies regarding management of cervical lymph nodes are discussed. Rare and unusual nasal cavity cancers, such as esthesioneuroblastoma and sinonasal undifferentiated carcinomas, are included. © 2016 American College of Radiology. Head Neck, 2016 © 2016 Wiley Periodicals, Inc. Head Neck 39: 407–418, 2017Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136245/1/hed24639.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136245/2/hed24639_am.pd

    546 Results from Phase Ib study of tebentafusp (tebe) in combination with durvalumab (durva) and/or tremelimumab (treme) in metastatic cutaneous melanoma (mCM)

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    BackgroundTebe, a T cell receptor fused to an anti-CD3 effector, can redirect T cells to target gp100+ cells and in Ph3, demonstrated overall survival (OS) benefit as monotherapy in metastatic uveal melanoma. In Ph2, any tumor shrinkage (44% of patients) was a better predictor of OS than response rate. In Ph1, Tebe had monotherapy activity in mCM, also a gp100+ tumor, with 1-year OS ~74% in PD-1 naïve mCM. A Ph1 dose escalation of tebe with durva (anti-PD-L1) and/or treme (anti-CTLA4) was conducted in pre-treated mCM [NCT02535078], with nearly all patients having prior PD1-treatment, and where recently reported therapies have 1-yr OS of ~55%.MethodsHeavily pre-treated HLA-A2+ mCM patients received weekly IV tebe alone (Arm 4) or with increasing doses of durva and/or treme (Arm 1–3) administered IV monthly starting day 15 of each cycle. Primary objective was to identify RP2D of combination therapy. Secondary objectives included adverse events (AE) and efficacy.Results112 pts received ≥1 tebe dose. Median age was 59, 77% were ECOG 0, and 37% were BRAFm (of which 71% received prior BRAFi/MEKi). 91% of pts were 2L+, while 74% were 3L+. 103 (92%) received prior PD-1 inhibitor, of which 87% also received prior ipilimumab. 43 pts received tebe + durva (Arm 1), 13 received tebe + treme (Arm 2), 29 received triplet therapy (Arm 3), and 27 received tebe alone (Arm 4). Maximum target doses of tebe (68 mcg) + durva (20 mg/kg) and treme (1 mg/kg) were tolerated. MTD was not formally identified for any arm. Two DLTs occurred: prolonged grade 3 rash (Arm 1) and grade 2 diarrhea leading to treatment delay (Arm 2). Related AEs that were Grade ≥3 or led to discontinuations were: 44%/0% (Arm 1), 23%/0% (Arm2), 38%/7% (Arm3), 26%/4% (Arm 4). There were no treatment-related deaths.In prior PD-1 pts, tumor shrinkage occurred in 36% and 1-yr OS was 68%. Of 51 evaluable PD-1 resistant pts (best response CR/PR/SD to prior PD1), tumor shrinkage occurred in 28% and 1-yr OS was 73% (figure 1). In 35 evaluable PD-1 refractory pts (prior best response PD), tumor shrinkage occurred in 49% and 1-yr OS was 61%. For 38 prior PD-1 pts who received ≥10mg/kg durva, 1-yr OS was 81%.Abstract 546 Figure 1% tumor change from baseline in evaluable patients with known response to prior PD1 exposureConclusionsTebe with anti-PD-L1 and/or anti-CTLA4 had an acceptable safety profile. Tebe + durva demonstrated durable tumor shrinkage and promising 1-yr OS rates in prior-PD1 treated mCM relative to recent reports.Trial RegistrationNCT02535078Ethics ApprovalThe institutional review board or independent ethics committee at each center approved the trial. The trial was conducted in accordance with the Declaration of Helsinki and the International Conference on Harmonization Good Clinical Practice guidelines

    The Need for Laboratory Measurements and Ab Initio Studies to Aid Understanding of Exoplanetary Atmospheres

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    We are now on a clear trajectory for improvements in exoplanet observations that will revolutionize our ability to characterize their atmospheric structure, composition, and circulation, from gas giants to rocky planets. However, exoplanet atmospheric models capable of interpreting the upcoming observations are often limited by insufficiencies in the laboratory and theoretical data that serve as critical inputs to atmospheric physical and chemical tools. Here we provide an up-to-date and condensed description of areas where laboratory and/or ab initio investigations could fill critical gaps in our ability to model exoplanet atmospheric opacities, clouds, and chemistry, building off a larger 2016 white paper, and endorsed by the NAS Exoplanet Science Strategy report. Now is the ideal time for progress in these areas, but this progress requires better access to, understanding of, and training in the production of spectroscopic data as well as a better insight into chemical reaction kinetics both thermal and radiation-induced at a broad range of temperatures. Given that most published efforts have emphasized relatively Earth-like conditions, we can expect significant and enlightening discoveries as emphasis moves to the exotic atmospheres of exoplanets.Comment: Submitted as an Astro2020 Science White Pape

    Measles vaccination in humanitarian emergencies: a review of recent practice

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    <p>Abstract</p> <p>Background</p> <p>The health needs of children and adolescents in humanitarian emergencies are critical to the success of relief efforts and reduction in mortality. Measles has been one of the major causes of child deaths in humanitarian emergencies and further contributes to mortality by exacerbating malnutrition and vitamin A deficiency. Here, we review measles vaccination activities in humanitarian emergencies as documented in published literature. Our main interest was to review the available evidence focusing on the target age range for mass vaccination campaigns either in response to a humanitarian emergency or in response to an outbreak of measles in a humanitarian context to determine whether the current guidance required revision based on recent experience.</p> <p>Methods</p> <p>We searched the published literature for articles published from January 1, 1998 to January 1, 2010 reporting on measles in emergencies. As definitions and concepts of emergencies vary and have changed over time, we chose to consider any context where an application for either a Consolidated Appeals Process or a Flash Appeal to the UN Central Emergency Revolving Fund (CERF) occurred during the period examined. We included publications from countries irrespective of their progress in measles control as humanitarian emergencies may occur in any of these contexts and as such, guidance applies irrespective of measles control goals.</p> <p>Results</p> <p>Of the few well-documented epidemic descriptions in humanitarian emergencies, the age range of cases is not limited to under 5 year olds. Combining all data, both from preventive and outbreak response interventions, about 59% of cases in reports with sufficient data reviewed here remain in children under 5, 18% in 5-15 and 2% above 15 years. In instances where interventions targeted a reduced age range, several reports concluded that the age range should have been extended to 15 years, given that a significant proportion of cases occurred beyond 5 years of age.</p> <p>Conclusions</p> <p>Measles outbreaks continue to occur in humanitarian emergencies due to low levels of pre-existing population immunity. According to available published information, cases continue to occur in children over age 5. Preventing cases in older age groups may prevent younger children from becoming infected and reduce mortality in both younger and older age groups.</p

    Overall Survival Benefit with Tebentafusp in Metastatic Uveal Melanoma

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    Background: Uveal melanoma is a disease that is distinct from cutaneous melanoma, with a low tumor mutational burden and a 1-year overall survival of approximately 50% in patients with metastatic uveal melanoma. Data showing a proven overall survival benefit with a systemic treatment are lacking. Tebentafusp is a bispecific protein consisting of an affinity-enhanced T-cell receptor fused to an anti-CD3 effector that can redirect T cells to target glycoprotein 100-positive cells. Methods: In this open-label, phase 3 trial, we randomly assigned previously untreated HLA-A*02:01-positive patients with metastatic uveal melanoma in a 2:1 ratio to receive tebentafusp (tebentafusp group) or the investigator's choice of therapy with single-agent pembrolizumab, ipilimumab, or dacarbazine (control group), stratified according to the lactate dehydrogenase level. The primary end point was overall survival. Results: A total of 378 patients were randomly assigned to either the tebentafusp group (252 patients) or the control group (126 patients). Overall survival at 1 year was 73% in the tebentafusp group and 59% in the control group (hazard ratio for death, 0.51; 95% confidence interval [CI], 0.37 to 0.71; P<0.001) in the intention-to-treat population. Progression-free survival was also significantly higher in the tebentafusp group than in the control group (31% vs. 19% at 6 months; hazard ratio for disease progression or death, 0.73; 95% CI, 0.58 to 0.94; P = 0.01). The most common treatment-related adverse events in the tebentafusp group were cytokine-mediated events (due to T-cell activation) and skin-related events (due to glycoprotein 100-positive melanocytes), including rash (83%), pyrexia (76%), and pruritus (69%). These adverse events decreased in incidence and severity after the first three or four doses and infrequently led to discontinuation of the trial treatment (2%). No treatment-related deaths were reported. Conclusions: Treatment with tebentafusp resulted in longer overall survival than the control therapy among previously untreated patients with metastatic uveal melanoma. (Funded by Immunocore; ClinicalTrials.gov number, NCT03070392; EudraCT number, 2015-003153-18.). Copyright © 2021 Massachusetts Medical Society
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