158 research outputs found
Modern affinity reagents: Recombinant antibodies and aptamers
AbstractAffinity reagents are essential tools in both basic and applied research; however, there is a growing concern about the reproducibility of animal-derived monoclonal antibodies. The need for higher quality affinity reagents has prompted the development of methods that provide scientific, economic, and time-saving advantages and do not require the use of animals. This review describes two types of affinity reagents, recombinant antibodies and aptamers, which are non-animal technologies that can replace the use of animal-derived monoclonal antibodies. Recombinant antibodies are protein-based reagents, while aptamers are nucleic-acid-based. In light of the scientific advantages of these technologies, this review also discusses ways to gain momentum in the use of modern affinity reagents, including an update to the 1999 National Academy of Sciences monoclonal antibody production report and federal incentives for recombinant antibody and aptamer efforts. In the long-term, these efforts have the potential to improve the overall quality and decrease the cost of scientific research
Blueprint for a National Food Strategy: Evaluating the Potential for a National Food Strategy in the United States
Eating is a fundamental human need, and the food and agriculture system is vital to the American economy. Yet, our food system often works at cross-purposes, providing abundance while creating inefficiencies, and imposing unnecessary burdens on our economy, environment, and overall health. Many federal policies, laws, and regulations guide and structure our food system. However, these laws are fragmented and sometimes inconsistent, hindering food system improvements. To promote a healthy, economically viable, equitable, and resilient food system, the United States needs a coordinated federal approach to food and agricultural law and policy – that is, a national food strategy.A national food strategy has the potential to offer a comprehensive, coordinated path forward to improve the food system. Specifically, it could help leaders and members of the public understand how various aspects of food and agriculture connect and are interdependent. The process of developing a strategy could clarify where agencies and legislators currently undertake overlapping or conflicting activities. In addition, the process could provide opportunities for soliciting and incorporating public and stakeholder input. Ultimately, a national food strategy could harmonize law and policymaking around food and agriculture, providing a mechanism for legislators and agencies to establish, prioritize, and pursue common goals.This report provides a roadmap for the process to develop a national food strategy. Consequently, it focuses primarily on process rather than policy, because an effective process is a critical foundation to any coordinated strategy. In developing this blueprint, this report examines several models, which collectively may chart a path for such a strategy. First, several nations have developed national food strategies that may inform American efforts. These countries generally have food system challenges similar to those in the United States – e.g., maintaining or improving the success and resilience of the food and agricultural sectors, ensuring access to healthy food, promoting sustainable food production, and harmonizing the work of numerous agencies. Their strategies also illustrate a range of methods that can be used to engage agencies, diverse stakeholders, and the general public in strategy creation.The United States also serves as a model for this blueprint, as there are many domestic national strategies addressing a range of topics. This report explores select U.S. national strategies on diverse issues from the domestic HIV/AIDS epidemic to environmental justice. These strategies serve to illustrate the legal and policy mechanisms employed by domestic efforts to address important and complex social issues in need of federal coordination. Regardless of the motivation, these domestic strategies share key components and characteristics, including utilizing an organizing authority, incorporating stakeholder and public engagement, enshrining goals in a written document, and ensuring periodic updating. These mechanisms demonstrate the capacity of the U.S. political system to address complex issues, and these key components provide a framework for the features that should structure a national food strategy.Presently, our food system struggles to serve the needs and interests of all Americans. The piecemeal policy and regulatory framework pertaining to food and agriculture also fails to accomplish needed improvements. Yet, the United States possesses the tools needed to address this vital system. A comprehensive and coordinated federal approach to law and policymaking is critical to an economically viable, resilient, equitable and food secure future for America. To that end, this report identifies four major principles to guide the creation of a national food strategy in the United States. Each principle describes the findings supporting it and includes a set of recommendations to lay the foundation for an effective comprehensive national strategy
Mechanical dysfunction of the sarcomere induced by a pathogenic mutation in troponin T drives cellular adaptation
Familial hypertrophic cardiomyopathy (HCM), a leading cause of sudden cardiac death, is primarily caused by mutations in sarcomeric proteins. The pathogenesis of HCM is complex, with functional changes that span scales, from molecules to tissues. This makes it challenging to deconvolve the biophysical molecular defect that drives the disease pathogenesis from downstream changes in cellular function. In this study, we examine an HCM mutation in troponin T, R92Q, for which several models explaining its effects in disease have been put forward. We demonstrate that the primary molecular insult driving disease pathogenesis is mutation-induced alterations in tropomyosin positioning, which causes increased molecular and cellular force generation during calcium-based activation. Computational modeling shows that the increased cellular force is consistent with the molecular mechanism. These changes in cellular contractility cause downstream alterations in gene expression, calcium handling, and electrophysiology. Taken together, our results demonstrate that molecularly driven changes in mechanical tension drive the early disease pathogenesis of familial HCM, leading to activation of adaptive mechanobiological signaling pathways
Variant R94C in TNNT2‐encoded troponin T predisposes to pediatric restrictive dardiomyopathy and sudden death through impaired thin filament relaxation resulting in myocardial diastolic dysfunction
Background Pediatric-onset restrictive cardiomyopathy (RCM) is associated with high mortality, but underlying mechanisms of disease are under investigated. RCM-associated diastolic dysfunction secondary to variants i
Use of EpiAlveolar Lung Model to Predict Fibrotic Potential of Multiwalled Carbon Nanotubes
Expansion in production and commercial use of nanomaterials increases the potential human exposure during the lifecycle of these materials (production, use, and disposal). Inhalation is a primary route of exposure to nanomaterials; therefore it is critical to assess their potential respiratory hazard. Herein, we developed a three-dimensional alveolar model (EpiAlveolar) consisting of human primary alveolar epithelial cells, fibroblasts, and endothelial cells, with or without macrophages for predicting long-term responses to aerosols. Following thorough characterization of the model, proinflammatory and profibrotic responses based on the adverse outcome pathway concept for lung fibrosis were assessed upon repeated subchronic exposures (up to 21 days) to two types of multiwalled carbon nanotubes (MWCNTs) and silica quartz particles. We simulate occupational exposure doses for the MWCNTs (1–30 μg/cm2) using an air–liquid interface exposure device (VITROCELL Cloud) with repeated exposures over 3 weeks. Specific key events leading to lung fibrosis, such as barrier integrity and release of proinflammatory and profibrotic markers, show the responsiveness of the model. Nanocyl induced, in general, a less pronounced reaction than Mitsui-7, and the cultures with human monocyte- derived macrophages (MDMs) showed the proinflammatory response at later time points than those without MDMs. In conclusion, we present a robust alveolar model to predict inflammatory and fibrotic responses upon exposure to MWCNTs
Use of EpiAlveolar Lung Model to Predict Fibrotic Potential of Multiwalled Carbon Nanotubes
Expansion in production and commercial use of nanomaterials increases the potential human exposure during the lifecycle of these materials (production, use, and disposal). Inhalation is a primary route of exposure to nanomaterials; therefore it is critical to assess their potential respiratory hazard. Herein, we developed a three-dimensional alveolar model (EpiAlveolar) consisting of human primary alveolar epithelial cells, fibroblasts, and endothelial cells, with or without macrophages for predicting long-term responses to aerosols. Following thorough characterization of the model, proinflammatory and profibrotic responses based on the adverse outcome pathway concept for lung fibrosis were assessed upon repeated subchronic exposures (up to 21 days) to two types of multiwalled carbon nanotubes (MWCNTs) and silica quartz particles. We simulate occupational exposure doses for the MWCNTs (1–30 μg/cm2) using an air–liquid interface exposure device (VITROCELL Cloud) with repeated exposures over 3 weeks. Specific key events leading to lung fibrosis, such as barrier integrity and release of proinflammatory and profibrotic markers, show the responsiveness of the model. Nanocyl induced, in general, a less pronounced reaction than Mitsui-7, and the cultures with human monocyte- derived macrophages (MDMs) showed the proinflammatory response at later time points than those without MDMs. In conclusion, we present a robust alveolar model to predict inflammatory and fibrotic responses upon exposure to MWCNTs
Expert consensus on an in vitro approach to assess pulmonary fibrogenic potential of aerosolized nanomaterials
The increasing use of multi-walled carbon nanotubes (MWCNTs) in consumer products and their potential to induce adverse lung effects following inhalation has lead to much interest in better understanding the hazard associated with these nanomaterials (NMs). While the current regulatory requirement for substances of concern, such as MWCNTs, in many jurisdictions is a 90-day rodent inhalation test, the monetary, ethical, and scientific concerns associated with this test led an international expert group to convene in Washington, DC, USA, to discuss alternative approaches to evaluate the inhalation toxicity of MWCNTs. Pulmonary fibrosis was identified as a key adverse outcome linked to MWCNT exposure, and recommendations were made on the design of an in vitro assay that is predictive of the fibrotic potential of MWCNTs. While fibrosis takes weeks or months to develop in vivo, an in vitro test system may more rapidly predict fibrogenic potential by monitoring pro-fibrotic mediators (e.g., cytokines and growth factors). Therefore, the workshop discussions focused on the necessary specifications related to the development and evaluation of such an in vitro system. Recommendations were made for designing a system using lung-relevant cells co-cultured at the air–liquid interface to assess the pro-fibrogenic potential of aerosolized MWCNTs, while considering human-relevant dosimetry and NM life cycle transformations. The workshop discussions provided the fundamental design components of an air–liquid interface in vitro test system that will be subsequently expanded to the development of an alternative testing strategy to predict pulmonary toxicity and to generate data that will enable effective risk assessment of NMs
Why Reform Fails : The ‘Politics of Policies’ in Costa Rican Telecommunications Liberalization
As the \u27Washington Consensus\u27 reforms are losing momentum in Latin America, the Inter-
American Development Bank (IDB) is calling for shifting the focus from the content of policy
choices to the political process of their implementation. As this paper studies the paradigmatic
case of telecommunications reform in Costa Rica it underscores the importance
of these \u27politics of policies\u27. The analysis finds, however, that the failure of repeated liberalization
initiatives was not only due to policy-makers\u27 errors in steering the project
through \u27the messy world of politics\u27 (IDB); instead, as liberalization remained unpopular,
policy content indeed mattered, and only the interaction of both explains the outcome.
Particular attention is drawn to the political feed-back effects, as the failed reform, precisely
because it had been backed by bi-partisan support, became a catalyst for the disintegration
of the country\u27s long-standing two-party system.In dem Maße, in dem die mit dem „Washington Consensus“ verbundenen Reformen in Lateinamerika
ins Stocken geraten sind, plädiert die Inter-American Development Bank (IDB)
für eine stärkere Berücksichtigung nicht nur der Politikinhalte (policies), sondern auch des
politischen Prozesses von deren Umsetzung (politics). Die vorliegende Untersuchung zum
paradigmatischen Fall der Reform des Telekommunikationssektors in Costa Rica unterstreicht
die Bedeutung dieser „politics of policies“. Sie zeigt allerdings auch, dass Ursache
für das Scheiten wiederholter Liberalisierungsinitiativen nicht nur Fehler der Politiker sind,
das Vorhaben durch „die unordentliche Welt der politics“ (IDB) zu steuern. Die breite gesellschaftliche
Opposition gegen den Liberalisierungskurs bleibt. Nur die Interaktion von beiden,
politics und policies, erklärt Verlauf und Ergebnis der Reform. Besonderes Augenmerk
widmet die Studie den politischen Rückwirkungen der gescheiterten Reform: Sie wurde,
just weil sie von beiden etablierten Parteien unterstützt wurde, zum Katalysator für den Zerfall
des seit Jahrzehnten etablierten Zweiparteiensystems des Landes
Rules for Growth: Promoting Innovation and Growth Through Legal Reform
The United States economy is struggling to recover from its worst economic downturn since the Great Depression. After several huge doses of conventional macroeconomic stimulus - deficit-spending and monetary stimulus - policymakers are understandably eager to find innovative no-cost ways of sustaining growth both in the short and long runs. In response to this challenge, the Kauffman Foundation convened a number of America’s leading legal scholars and social scientists during the summer of 2010 to present and discuss their ideas for changing legal rules and policies to promote innovation and accelerate U.S. economic growth. This meeting led to the publication of Rules for Growth: Promoting Innovation and Growth Through Legal Reform, a comprehensive and groundbreaking volume of essays prescribing a new set of growth-promoting policies for policymakers, legal scholars, economists, and business men and women. Some of the top Rules include: • Reforming U.S. immigration laws so that more high-skilled immigrants can launch businesses in the United States. • Improving university technology licensing practices so university-generated innovation is more quickly and efficiently commercialized. • Moving away from taxes on income that penalize risk-taking, innovation, and employment while shifting toward a more consumption-based tax system that encourages saving that funds investment. In addition, the research tax credit should be redesigned and made permanent. • Overhauling local zoning rules to facilitate the formation of innovative companies. • Urging judges to take a more expansive view of flexible business contracts that are increasingly used by innovative firms. • Urging antitrust enforcers and courts to define markets more in global terms to reflect contemporary realities, resist antitrust enforcement from countries with less sound antitrust regimes, and prohibit industry trade protection and subsidies. • Reforming the intellectual property system to allow for a post-grant opposition process and address the large patent application backlog by allowing applicants to pay for more rapid patent reviews. • Authorizing corporate entities to form digitally and use software as a means for setting out agreements and bylaws governing corporate activities. The collective essays in the book propose a new way of thinking about the legal system that should be of interest to policymakers and academic scholars alike. Moreover, the ideas presented here, if embodied in law, would augment a sustained increase in U.S. economic growth, improving living standards for U.S. residents and for many in the rest of the world
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