149 research outputs found
Reduced glycogen availability is associated with increased AMPKα2 activity, nuclear AMPKα2 protein abundance, and GLUT4 mRNA expression in contracting human skeletal muscle
Glycogen availability can influence glucose transporter 4 (GLUT4) expression in skeletal muscle through unknown mechanisms. The multisubstrate enzyme AMP-activated protein kinase (AMPK) has also been shown to play an important role in the regulation of GLUT4 expression in skeletal muscle. During contraction, AMPK [alpha]2 translocates to the nucleus and the activity of this AMPK isoform is enhanced when skeletal muscle glycogen is low. In this study, we investigated if decreased pre-exercise muscle glycogen levels and increased AMPK [alpha]2 activity reduced the association of AMPK with glycogen and increased AMPK [alpha]2 translocation to the nucleus and GLUT4 mRNA expression following exercise. Seven males performed 60 min of exercise at ~70% [VO.sub.2] peak on 2 occasions: either with normal (control) or low (LG) carbohydrate pre-exercise muscle glycogen content. Muscle samples were obtained by needle biopsy before and after exercise. Low muscle glycogen was associated with elevated AMPK [alpha]2 activity and acetyl-CoA carboxylase [beta] phosphorylation, increased translocation of AMPK [alpha]2 to the nucleus, and increased GLUT4 mRNA. Transfection of primary human myotubes with a constitutively active AMPK adenovirus also stimulated GLUT4 mRNA, providing direct evidence of a role of AMPK in regulating GLUT4 expression. We suggest that increased activation of AMPK [alpha]2 under conditions of low muscle glycogen enhances AMPK [alpha]2 nuclear translocation and increases GLUT4 mRNA expression in response to exercise in human skeletal muscle. <br /
The Effect of Electronic Cigarette User Modifications and E-liquid Adulteration on the Particle Size Profile of an Aerosolized Product
Electronic cigarettes (e-cigarettes) are an alternate nicotine delivery system that generate a condensation aerosol to be inhaled by the user. The size of the droplets formed in the aerosol can vary and contributes to drug deposition and ultimate bioavailability in the lung. The growing popularity of e-cigarette products has caused an increase in internet sources promoting the use of drugs other than nicotine (DOTNs) in e-cigarettes. The purpose of this study was to determine the effect of various e-cigarette and e-liquid modifications, such as coil resistance, battery voltage, and glycol and drug formulation, on the aerosol particle size. E-liquids containing 12 mg/mL nicotine prepared in glycol compositions of 100% propylene glycol (PG), 100% vegetable glycerin (VG), or 50:50 PG:VG were aerosolized at three voltages and three coil resistances. Methamphetamine and methadone e-liquids were prepared at 60 mg/mL in 50:50 PG:VG and all e-liquids were aerosolized onto a 10 stage Micro-Orifice Uniform Deposit Impactor. Glycol deposition correlated with drug deposition, and the majority of particles centered between 0.172–0.5 μm in diameter, representing pulmonary deposition. The 100% PG e-liquid produced the largest aerosol particles and the 100% VG and 50:50 PG:VG e-liquids produced ultra-fine particles \u3c0.3 μm. The presence of ultrafine particles indicates that drugs can be aerosolized and reach the pulmonary alveolar regions, highlighting a potential for abuse and risk of overdose with DOTNs aerosolized in an e-cigarette system
BREEDING BEHAVIOR OF THE GRAY-BREASTED FLYCATCHER (LATHROTRICCUS GRISEIPECTUS) IN SOUTHWESTERN ECUADOR
Abstract ∙ Little is known about the nesting behavior of the Gray-breasted Flycatcher (Lathrotriccus griseipectus), a species listed as Vulnerable by the International Union for Conservation of Nature. In order to add fundamental information on the life history of this species, we recorded parental behavior at a nest in February–March 2010 in the Jorupe Reserve in southwestern Ecuador. Recordings were made on a tripod-mounted video camera and took place during part of the incubation and nestling stages. Both adults provisioned nestlings. We recorded 7.1 feeds per nestling-hour, with the highest average provisioning rates occurring from 12:00–13:00 h. Nestlings produced an average of 0.8 fecal sacs per nestling-hour. Nestlings fledged in quick succession shortly before 12:00 h on nestling-day 14.Resumen ∙ El cuidado parental del Mosquero Pechigrís (Lathrotriccus griseipectus) en el suroeste del Ecuador La biología reproductiva del Mosquero Pechigrís (Lathrotriccus griseipectus), una especie catalogada como “Vulnerable” por la Unión Internacional para la Conservación de la Naturaleza, es poco conocida. Con el fin de añadir datos básicos sobre la historia de vida del Mosquero Pechigrís, utilizamos una cámara de video para realizar observaciones de un nido ubicado en la Reserva Jorupe en el suroeste de Ecuador, entre febrero y marzo de 2010. Las grabaciones tuvieron lugar durante parte de las etapas de incubación y polluelo. Ambos adultos aprovisionaron polluelos. Registramos 7.1 alimentaciones de polluelo por hora, siendo las tasas de aprovisionamiento más altas de 12:00–13:00 h. Los polluelos produjeron un promedio de 0.8 sacos fecales por hora y polluelo. Los polluelos emplumaron en rápida sucesión poco antes del mediodía 14 días luego de la eclosión
Analysis of ancestry heterozygosity suggests that hybrid incompatibilities in threespine stickleback are environment dependent
Hybrid incompatibilities occur when interactions between opposite ancestry alleles at different loci reduce the fitness of hybrids. Most work on incompatibilities has focused on those that are “intrinsic,” meaning they affect viability and sterility in the laboratory. Theory predicts that ecological selection can also underlie hybrid incompatibilities, but tests of this hypothesis using sequence data are scarce. In this article, we compiled genetic data for F(2) hybrid crosses between divergent populations of threespine stickleback fish (Gasterosteus aculeatus L.) that were born and raised in either the field (seminatural experimental ponds) or the laboratory (aquaria). Because selection against incompatibilities results in elevated ancestry heterozygosity, we tested the prediction that ancestry heterozygosity will be higher in pond-raised fish compared to those raised in aquaria. We found that ancestry heterozygosity was elevated by approximately 3% in crosses raised in ponds compared to those raised in aquaria. Additional analyses support a phenotypic basis for incompatibility and suggest that environment-specific single-locus heterozygote advantage is not the cause of selection on ancestry heterozygosity. Our study provides evidence that, in stickleback, a coarse—albeit indirect—signal of environment-dependent hybrid incompatibility is reliably detectable and suggests that extrinsic incompatibilities can evolve before intrinsic incompatibilities
Generalisability of vaccine effectiveness estimates: an analysis of cases included in a postlicensure evaluation of 13-valent pneumococcal conjugate vaccine in the USA
External validity, or generalisability, is the measure of how well results from a study pertain to individuals in the target population. We assessed generalisability, with respect to socioeconomic status, of estimates from a matched case–control study of 13-valent pneumococcal conjugate vaccine effectiveness for the prevention of invasive pneumococcal disease in children in the USA
A Baker\u27s Dozen of Top Antimicrobial Stewardship Intervention Publications in 2020
The number of articles related to antimicrobial stewardship published each year has increased significantly over the last decade. Keeping up with the literature, particularly the most innovative, well-designed, or applicable to one\u27s own practice area, can be challenging. The Southeastern Research Group Endeavor (SERGE-45) network reviewed antimicrobial stewardship-related, peer-reviewed literature from 2020 that detailed actionable interventions. The top 13 publications were summarized following identification using a modified Delphi technique. This article highlights the selected interventions and may serve as a key resource for teaching and training, and to identify novel or optimized stewardship opportunities within one\u27s institution
State-of-the-art methods for exposure-health studies: Results from the exposome data challenge event
The exposome recognizes that individuals are exposed simultaneously to a multitude of different environmental factors and takes a holistic approach to the discovery of etiological factors for disease. However, challenges arise when trying to quantify the health effects of complex exposure mixtures. Analytical challenges include dealing with high dimensionality, studying the combined effects of these exposures and their interactions, integrating causal pathways, and integrating high-throughput omics layers. To tackle these challenges, the Barcelona Institute for Global Health (ISGlobal) held a data challenge event open to researchers from all over the world and from all expertises. Analysts had a chance to compete and apply state-of-the-art methods on a common partially simulated exposome dataset (based on real case data from the HELIX project) with multiple correlated exposure variables (P > 100 exposure variables) arising from general and personal environments at different time points, biological molecular data (multi-omics: DNA methylation, gene expression, proteins, metabolomics) and multiple clinical phenotypes in 1301 mother–child pairs. Most of the methods presented included feature selection or feature reduction to deal with the high dimensionality of the exposome dataset. Several approaches explicitly searched for combined effects of exposures and/or their interactions using linear index models or response surface methods, including Bayesian methods. Other methods dealt with the multi-omics dataset in mediation analyses using multiple-step approaches. Here we discuss features of the statistical models used and provide the data and codes used, so that analysts have examples of implementation and can learn how to use these methods. Overall, the exposome data challenge presented a unique opportunity for researchers from different disciplines to create and share state-of-the-art analytical methods, setting a new standard for open science in the exposome and environmental health field
Patents and Industrialisation. An Historical Overview of the British Case, 1624-1907
A Report to the Strategic Advisory Board on Intellectual Property Policy (SABIP), U
At the bottom of the differential diagnosis list: unusual causes of pediatric hypertension
Hypertension affects 1–5% of children and adolescents, and the incidence has been increasing in association with obesity. However, secondary causes of hypertension such as renal parenchymal diseases, congenital abnormalities and renovascular disorders still remain the leading cause of pediatric hypertension, particularly in children under 12 years old. Other less common causes of hypertension in children and adolescents, including immobilization, burns, illicit and prescription drugs, dietary supplements, genetic disorders, and tumors will be addressed in this review
- …