Toward System Change to Tackle Antimicrobial Resistance: Improving the Voluntary Stewardship of Antimicrobials in US Agriculture

From Executive Summary:This report presents the details of a research study looking at the potential for improving voluntary stewardship of antimicrobials in US agriculture, in the interests of tackling antimicrobial resistance (AMR). Failure to address AMR could lead to significant impacts on both human and animal health. Voluntary stewardship is an approach that relies on the willingness of food-animal producers and supportive industries (e.g., veterinary services and pharmaceutical companies), as well as broader stakeholders (e.g., public health policymakers and consumer advocates), to ensure the judicious use of antimicrobials without the need for regulation, legislation, mandatory compliance or statutory enforcement

Mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-M) and serine biosynthetic pathway genes are co-ordinately increased during anabolic agent-induced skeletal muscle growth

We aimed to identify novel molecular mechanisms for muscle growth during administration of anabolic agents. Growing pigs (Duroc/(Landrace/Large-White)) were administered Ractopamine (a beta-adrenergic agonist; BA; 20ppm in feed) or Reporcin (recombinant growth hormone; GH; 10mg/48hours injected) and compared to a control cohort (feed only; no injections) over a 27-day time course (1, 3, 7, 13 or 27-days). Longissimus Dorsi muscle gene expression was analyzed using Agilent porcine transcriptome microarrays and clusters of genes displaying similar expression profiles were identified using a modified maSigPro clustering algorithm. Anabolic agents increased carcass (p=0.002) and muscle weights (Vastus Lateralis: p<0.001; Semitendinosus: p=0.075). Skeletal muscle mRNA expression of serine/one-carbon/glycine biosynthesis pathway genes (Phgdh, Psat1 and Psph) and the gluconeogenic enzyme, phosphoenolpyruvate carboxykinase-M (Pck2/PEPCK-M), increased during treatment with BA, and to a lesser extent GH (p<0.001, treatment x time interaction). Treatment with BA, but not GH, caused a 2-fold increase in phosphoglycerate dehydrogenase (PHGDH) protein expression at days 3 (p<0.05) and 7 (p<0.01), and a 2-fold increase in PEPCK-M protein expression at day 7 (p<0.01). BA treated pigs exhibit a profound increase in expression of PHGDH and PEPCK-M in skeletal muscle, implicating a role for biosynthetic metabolic pathways in muscle growth

Poly(hydroxy acids) derived from the self-condensation of hydroxy acids: from polymerization to end-of-life options

[EN] Poly(hydroxy acids) have been gaining increasing attention in the search for novel sustainable materials to replace petrochemical polymers in packaging applications. Poly(hydroxy acids) are polyesters that are obtained using hydroxy acids as the starting materials, which are derived from renewable resources and biowaste. These biopolymers have attracted a lot of attention since some of them will be in the near future competitive in price to polyolefins, show excellent mechanical and barrier properties, and can be potentially recycled by physical and chemical routes. Most of the current poly(hydroxy acids) are mainly prepared by ring-opening polymerization (ROP) of cyclic monomers derived from hydroxy acids. However, their direct polymerization has received much less attention, while one of the advantages of hydroxy acids resides in the presence of an electrophile and a nucleophile in a single molecule that makes them ideal A-B type monomers for self-condensation. This review focuses on the preparation of poly(hydroxy acids) by the self-condensation polymerization of hydroxy acids. Moreover, their end-of-life options are also evaluated considering not only their biodegradability but also their potential to be chemically recycledThe authors thank the European Commission (EC) for financial support through the project SUSPOL-EJDH2020-ITN-2014-642671 and the Spanish Ministry of Science and Innovation (MICI) through the projects RTI2018-097249-B-C21, MAT2017-83373-R, and MAT-2016-78527-P. S. Torres-Giner also acknowledges MICI for his Juan de la Cierva-Incorporacion contract (IJCI-2016-29675) and the financial support received during his stay at the Institute for Polymer Materials (POLYMAT)Gabirondo, E.; Sangroniz, A.; Etxeberria, A.; Torres-Giner, S.; Sardon, H. (2020). Poly(hydroxy acids) derived from the self-condensation of hydroxy acids: from polymerization to end-of-life options. Polymer Chemistry. 11(30):4861-4874. https://doi.org/10.1039/D0PY00088DS48614874113