Septic patients frequently develop cognitive impairment that persists beyond hospital discharge. The impact of sepsis on electrophysiological and molecular determinants of learning is underexplored. ...We observed that mice that survived sepsis or endotoxemia experienced loss of hippocampal long-term potentiation (LTP), a brain-derived neurotrophic factor-mediated (BDNF-mediated) process responsible for spatial memory formation. Memory impairment occurred despite preserved hippocampal BDNF content and could be reversed by stimulation of BDNF signaling, suggesting the presence of a local BDNF inhibitor. Sepsis is associated with degradation of the endothelial glycocalyx, releasing heparan sulfate fragments (of sufficient size and sulfation to bind BDNF) into the circulation. Heparan sulfate fragments penetrated the hippocampal blood-brain barrier during sepsis and inhibited BDNF-mediated LTP. Glycoarray approaches demonstrated that the avidity of heparan sulfate for BDNF increased with sulfation at the 2-O position of iduronic acid and the N position of glucosamine. Circulating heparan sulfate in endotoxemic mice and septic humans was enriched in 2-O- and N-sulfated disaccharides; furthermore, the presence of these sulfation patterns in the plasma of septic patients at intensive care unit (ICU) admission predicted persistent cognitive impairment 14 days after ICU discharge or at hospital discharge. Our findings indicate that circulating 2-O- and N-sulfated heparan sulfate fragments contribute to septic cognitive impairment.
Although plasma proteins have important roles in biological processes and are the direct targets of many drugs, the genetic factors that control inter-individual variation in plasma protein levels ...are not well understood. Here we characterize the genetic architecture of the human plasma proteome in healthy blood donors from the INTERVAL study. We identify 1,927 genetic associations with 1,478 proteins, a fourfold increase on existing knowledge, including trans associations for 1,104 proteins. To understand the consequences of perturbations in plasma protein levels, we apply an integrated approach that links genetic variation with biological pathway, disease, and drug databases. We show that protein quantitative trait loci overlap with gene expression quantitative trait loci, as well as with disease-associated loci, and find evidence that protein biomarkers have causal roles in disease using Mendelian randomization analysis. By linking genetic factors to diseases via specific proteins, our analyses highlight potential therapeutic targets, opportunities for matching existing drugs with new disease indications, and potential safety concerns for drugs under development.
This paper explores financial reporting incentives created by an economy's institutional structure. The underlying premise of our analysis is that a country's legal/judicial system, securities laws, ...and political economy create incentives that influence the behavior of corporate executives, investors, regulators and other market participants. Further, such incentives ultimately shape the properties of reported accounting numbers. We empirically analyze relations between key characteristics of country-level institutions and the asymmetric recognition of economic gains and losses into earnings (i.e., conditional conservatism). We also provide evidence on channels through which specific institutions manifest their influence on observed conservatism.
A method for the decarboxylative macrocyclization of peptides bearing N‐terminal Michael acceptors has been developed. This synthetic method enables the efficient synthesis of cyclic peptides ...containing γ‐amino acids and is tolerant of functionalities present in both natural and non‐proteinogenic amino acids. Linear precursors ranging from 3 to 15 amino acids cyclize effectively under this photoredox method. To demonstrate the preparative utility of this method in the context of bioactive molecules, we synthesized COR‐005, a somatostatin analogue that is currently in clinical trials.
Oh, take me back to the start: A method for the decarboxylative macrocyclization of peptides bearing N‐terminal Michael acceptors was developed. This photoredox method enables efficient synthesis of cyclic peptides containing γ‐amino acids and is tolerant of functionalities present in natural amino acids. Linear precursors ranging from 3 to 15 amino acids can be effectively cyclized by using this method.
Interstitial tissue acidosis resulting from abnormal perfusion and metabolism is a hallmark of cancer. The current study demonstrates that chemical exchange saturation transfer (CEST) MRI can be used ...as a noninvasive pH-weighted molecular imaging technique by targeting the chemical exchange between amine protons and protons in extracellular bulk water.
First, the sensitivity of amine CEST was validated in phantoms under a variety of conditions, including different magnetic field strengths, amino acid concentrations, and pH values. Amine CEST was compared with histology in both a preclinical GL261 intracranial glioma model at 7T and human patients at 3T. The association between physiologic and pH-weighted MRI was explored, along with the ability to predict time to progression to radiochemotherapy in 20 glioblastoma patients.
z-Spectral asymmetry increased at 3 ppm (amine range) on CEST MRI with decreasing pH within the range observed in tumors for both 3T and 7T scanners. Lesions with acidic signatures showed active tumor and pseudopalisading tumor on histology and showed elevated FDOPA PET uptake, lactate on MR spectroscopy, and perfusion abnormalities. Patients with acidic lesions after surgery or stable/growing acidic lesions had a shorter time to progression following radiochemotherapy compared with patients with lesions demonstrating relatively low acidity (P < .001).
Results suggest pH-weighted MRI may provide new insight into brain tumor physiology beyond traditional imaging technologies.
IMPORTANCE: Extenuating circumstances can trigger unplanned changes to randomized trials and introduce methodological, ethical, feasibility, and analytical challenges that can potentially compromise ...the validity of findings. Numerous randomized trials have required changes in response to the COVID-19 pandemic, but guidance for reporting such modifications is incomplete. OBJECTIVE: As a joint extension for the CONSORT and SPIRIT reporting guidelines, CONSERVE (CONSORT and SPIRIT Extension for RCTs Revised in Extenuating Circumstances) aims to improve reporting of trial protocols and completed trials that undergo important modifications in response to extenuating circumstances. EVIDENCE: A panel of 37 international trial investigators, patient representatives, methodologists and statisticians, ethicists, funders, regulators, and journal editors convened to develop the guideline. The panel developed CONSERVE following an accelerated, iterative process between June 2020 and February 2021 involving (1) a rapid literature review of multiple databases (OVID Medline, OVID EMBASE, and EBSCO CINAHL) and gray literature sources from 2003 to March 2021; (2) consensus-based panelist meetings using a modified Delphi process and surveys; and (3) a global survey of trial stakeholders. FINDINGS: The rapid review yielded 41 673 citations, of which 38 titles were relevant, including emerging guidance from regulatory and funding agencies for managing the effects of the COVID-19 pandemic on trials. However, no generalizable guidance for all circumstances in which trials and trial protocols might face unanticipated modifications were identified. The CONSERVE panel used these findings to develop a consensus reporting guidelines following 4 rounds of meetings and surveys. Responses were received from 198 professionals from 34 countries, of whom 90% (n = 178) indicated that they understood the concept definitions and 85.4% (n = 169) indicated that they understood and could use the implementation tool. Feedback from survey respondents was used to finalize the guideline and confirm that the guideline’s core concepts were applicable and had utility for the trial community. CONSERVE incorporates an implementation tool and checklists tailored to trial reports and trial protocols for which extenuating circumstances have resulted in important modifications to the intended study procedures. The checklists include 4 sections capturing extenuating circumstances, important modifications, responsible parties, and interim data analyses. CONCLUSIONS AND RELEVANCE: CONSERVE offers an extension to CONSORT and SPIRIT that could improve the transparency, quality, and completeness of reporting important modifications to trials in extenuating circumstances such as COVID-19.
This paper uses a structural model to understand, predict, and evaluate the impact of an exogenous microcredit intervention program, the Thai Million Baht Village Fund program. We model household ...decisions in the face of borrowing constraints, income uncertainty, and high-yield indivisible investment opportunities. After estimation of parameters using preprogram data, we evaluate the model's ability to predict and interpret the impact of the village fund intervention. Simulations from the model mirror the data in yielding a greater increase in consumption than credit, which is interpreted as evidence of credit constraints. A cost-benefit analysis using the model indicates that some households value the program much more than its per household cost, but overall the program costs 30 percent more than the sum of these benefits.
ABC transporters form one of the largest protein superfamilies in all domains of life, catalyzing the movement of diverse substrates across membranes. In this key position, ABC transporters can ...mediate multidrug resistance in cancer therapy and their dysfunction is linked to various diseases. Here, we describe the 2.7-Å X-ray structure of heterodimeric Thermus thermophilus multidrug resistance proteins A and B (TmrAB), which not only shares structural homology with the antigen translocation complex TAP, but is also able to restore antigen processing in human TAP-deficient cells. TmrAB exhibits a broad peptide specificity and can concentrate substrates several thousandfold, using only one single active ATP-binding site. In our structure, TmrAB adopts an asymmetric inward-facing state, and we show that the C-terminal helices, arranged in a zipper-like fashion, play a crucial role in guiding the conformational changes associated with substrate transport. In conclusion, TmrAB can be regarded as a model system for asymmetric ABC exporters in general, and for TAP in particular.
A Report of the American College of Cardiology Appropriate Use Criteria Task Force, American Academy of Pediatrics, American Heart Association, American Society of Echocardiography, Heart Rhythm ...Society, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, and Society of Pediatric Echocardiography Rating Panel Robert M. Campbell, MD, FACC, FAHA, FAAP, FHRS, Chairlow * Pamela S. Douglas, MD, MACC, FAHA, FASE, Moderatorlow * Louis I. Bezold, MD, FACC, FAAP, FASEdagger William B. Blanchard, MD, FACC, FAHA, FAAPlow * Jeffrey R. Boris, MD, FACClow * Bryan Cannon, MDdouble dagger Gregory J. Ensing, MD, FACC, FASE§ Craig E. Fleishman, MD, FACC, FASE|| Mark A. Fogel, MD, FACC, FAHA, FAAP¶ B. Kelly Han, MD, FACC# Shabnam Jain, MD, MPH, FAAPlow * Mark B. Lewin, MD|| Richard Lockwood, MDlow *low * G. Paul Matherne, MD, MBA, FACC, FAHAdaggerdagger David Nykanen, MD, FACCdouble daggerdouble dagger Catherine L. Webb, MD, FACC, FAHA, FASEdaggerdagger Robert Wiskind, MD, FAAPlow *American College of Cardiology representative.American Academy of Pediatrics representative.Heart Rhythm Society representative.American Society of Echocardiography representative.Society of Pediatric Echocardiography representative.Society for Cardiovascular Magnetic Resonance representative.Society of Cardiovascular Computed Tomography representative.Health Plan representative.American Heart Association representative.Society for Cardiovascular Angiography and Interventions representative.
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