Project description:The fluoropyrimidines 5-fluorouracil (5FU) and capecitabine (Cp) are among the most commonly used anticancer drugs. Still, there is much controversy about the correct dosing, and the fact that a minority of patients experience severe, sometimes even lethal toxicity following treatment. One important factor predisposing patients to severe toxicity is deficiency in the 5FU-catabolic enzyme dihydropyrimidine dehydrogenase (DPD). Our group identified 4 DPD risk alleles in over 300 Swiss cancer patients, that resulted in a 8-times increased risk of experiencing severe toxicity from 5FU or Cp. In patients receiving 5FU as a continuous infusion, there are accumulating data that keeping the AUC of 5FU between 20-30 mg*h/L is beneficial in terms of treatment toxicity and activity. In this study, patients carrying at least 1/4 DPD risk alleles will receive a 50% dose reduction of either 5FU or Cp, with the potential of later dose increases in the abscence of severe toxicity. Additionally, patients receiving i.v. 5FU will undergo therapeutic drug monitoring at the end of the 2-day continuous infusion, with subsequent dose adaptations to target a 5FU AUC of 20-30 mg*h/L. The primary study objective is to reduce the incidence of severe treatment-related toxicity from 13% (in historical controls) to 5% in study patients.
Project description:This article reports on the use of respondent-driven sampling (RDS) in participatory and community-based research. Participant-driven recruitment (PDR) retains all of the analytic capabilities of RDS while enhancing the role of respondents in framing research questions, instrument development, data interpretation, and other aspects of the research process. Merging the capabilities of RDS with participatory research methods, PDR creates new opportunities for engaging community members in research addressing social issues and in utilizing research findings within community contexts. This article outlines PDR's synthesis of RDS and participatory research approaches, describes how PDR is implemented in community contexts, and provides two examples of the use of PDR, illustrating its process, potentials, and challenges.
Project description:This is a hypothesis driven, open label, single-arm, multiple centers, Phase II trial. The trial has been designed to prove or disprove whether a rechallenge with panitumumab can achieve an objective response rate (ORR= CR+PR) of 30% or more in a population of RAS wild type mCRC patients selected on the basis of RAS extended clonal evolution in their plasma.
Project description:What we direct our attention to is strongly influenced by both bottom-up and top-down processes. Moreover, the control of attention is biased by prior learning, such that attention is automatically captured by stimuli previously associated with either reward or threat. It is unknown whether value-oriented and threat-oriented mechanisms of selective information processing function independently of one another, or whether they interact with each other in the selection process. Here, we introduced the threat of electric shock into the value-driven attentional capture paradigm to examine whether the experience of threat influences the attention capturing quality of previously reward-associated stimuli. The results showed that value-driven attentional capture was blunted by the experience of threat. This contrasts with previous reports of threat potentiating attentional capture by physically salient stimuli, which we replicate here. Our findings demonstrate that threat selectively interferes with value-based but not salience-based attentional priority, consistent with a competitive relationship between value-based and threat-based information processing. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
Project description:Using integrated genomic analysis of 1.988 childhood and adult cases, we describe a revised taxonomy of B-cell acute lymphoblastic leukemia, which incorporates 23 subtypes defined by chromosomal rearrangements, sequence mutations, or heterogeneous genomic alterations. Two subtypes have frequent alterations of the B lymphoid transcription factor gene PAX5. One, PAX5alt, has diverse PAX5 alterations, and a second subtype is defined by a single mutation, PAX5 P80R. We show that P80R impairs B lymphoid development and promotes the development of B-ALL in vivo. These results demonstrate the utility of transcriptome sequencing to classify B-ALL and reinforce the central role of PAX5 as a checkpoint in B lymphoid maturation and leukemogenesis.
Project description:We present a novel free-energy calculation method that constructively integrates two distinct classes of nonequilibrium sampling techniques, namely, driven (e.g., steered molecular dynamics) and adaptive-bias (e.g., metadynamics) methods. By employing nonequilibrium work relations, we design a biasing protocol with an explicitly time- and history-dependent bias that uses on-the-fly work measurements to gradually flatten the free-energy surface. The asymptotic convergence of the method is discussed, and several relations are derived for free-energy reconstruction and error estimation. Isomerization reaction of an atomistic polyproline peptide model is used to numerically illustrate the superior efficiency and faster convergence of the method compared with its adaptive-bias and driven components in isolation.
Project description:Neoepitopes are the only truly tumor-specific antigens. Although potential neoepitopes can be readily identified using genomics, the neoepitopes that mediate tumor rejection constitute a small minority, and there is little consensus on how to identify them. Here, for the first time, we use a combination of genomics, unbiased discovery MS immunopeptidomics and targeted MS to directly identify neoepitopes that elicit actual tumor rejection in mice. We report that MS-identified neoepitopes are an astonishingly rich source of tumor rejection mediating neoepitopes. MS has also demonstrated unambiguously the presentation by MHC I, of confirmed tumor rejection neoepitopes which bind weakly to MHC I; this was done using DCs exogenously loaded with long peptides containing the weakly binding neoepitopes. Such weakly MHC I-binding neoepitopes are routinely excluded from analysis, and our demonstration of their presentation, and their activity in tumor rejection, reveals a broader universe of tumor-rejection neoepitopes than presently imagined. Modeling studies show that a mutation in the active neoepitope alters its conformation such that its T cell receptor-facing surface is significantly altered, increasing its exposed hydrophobicity. No such changes are observed in the inactive neoepitope. These results broaden our understanding of antigen presentation and help prioritize neoepitopes for personalized cancer immunotherapy.
Project description:Reward history, physical salience, and task relevance all influence the degree to which a stimulus competes for attention, reflecting value-driven, stimulus-driven, and goal-contingent attentional capture, respectively. Theories of value-driven attention have likened reward cues to physically salient stimuli, positing that reward cues are preferentially processed in early visual areas as a result of value-modulated plasticity in the visual system. Such theories predict a strong coupling between value-driven and stimulus-driven attentional capture across individuals. In the present study, we directly test this hypothesis, and demonstrate a robust correlation between value-driven and stimulus-driven attentional capture. Our findings suggest substantive overlap in the mechanisms of competition underlying the attentional priority of reward cues and physically salient stimuli.
Project description:Obtaining well-diffracting crystals of macromolecules remains a significant barrier to structure determination. Here we propose and test a new approach to crystallization, in which the crystallization target is fused to a polymerizing protein module, so that polymer formation drives crystallization of the target. We test the approach using a polymerization module called 2TEL, which consists of two tandem sterile alpha motif (SAM) domains from the protein translocation Ets leukemia (TEL). The 2TEL module is engineered to polymerize as the pH is lowered, which allows the subtle modulation of polymerization needed for crystal formation. We show that the 2TEL module can drive the crystallization of 11 soluble proteins, including three that resisted prior crystallization attempts. In addition, the 2TEL module crystallizes in the presence of various detergents, suggesting that it might facilitate membrane protein crystallization. The crystal structures of two fusion proteins show that the TELSAM polymer is responsible for the majority of contacts in the crystal lattice. The results suggest that biological polymers could be designed as crystallization modules.
Project description:In hydraulic fracturing, water is injected at high pressure to crack shale formations. More sustainable techniques use aqueous foams as injection fluids to reduce the water use and wastewater treatment of conventional hydrofractures. However, the physical mechanism of foam fracturing remains poorly understood, and this lack of understanding extends to other applications of compressible foams such as fire-fighting, energy storage, and enhanced oil recovery. Here we show that the injection of foam is much different from the injection of incompressible fluids and results in striking dynamics of fracture propagation that are tied to the compressibility of the foam. An understanding of bubble-scale dynamics is used to develop a model for macroscopic, compressible flow of the foam, from which a scaling law for the fracture length as a function of time is identified and exhibits excellent agreement with our experimental results.