32 research outputs found

    Oral contraceptives augment the exercise pressor reïŹ‚ex during isometric handgrip exercise

    Get PDF
    We sought to determine whether oral contraception alters the gender‐related differences observed in the exercise pressor reflex during isometric handgrip exercise. Fifteen men, fifteen normally menstruating women (WomenNM), and fifteen women taking monophasic oral contraceptives (WomenOC) completed two trials of a 3‐min isometric handgrip exercise protocol performed at 30% of their maximal voluntary contraction: (1) where arterial occlusion was applied to the previously exercising arm during a 3‐min recovery period (Occlusion trial); (2) where no arterial occlusion was applied during recovery (Control trial). Handgrip exercise elicited greater increases in mean arterial pressure (MAP) in MEN compared to both female groups (P < 0.05), and in WomenOC compared to WomenNM in both trials (P = 0.01, P = 0.03). After 3 min of recovery, sBP was 12% (P = 0.01) and 9% (P = 0.02) higher in the Occlusion trial when compared to the Control trial for MEN and WomenOC. Conversely, arterial occlusion in recovery from handgrip did not sustain elevated sBP in the Occlusion trial, and sBP returned to recovery levels not different to the Control trial, in WomenNM (P = 0.41). These data indicate that gender‐related differences in the metaboreflex during isometric handgrip exercise exist between men and normally menstruating women, but are blunted when men are compared to women taking oral contraceptives. We conclude that the suppression of 17ÎČ‐estradiol and/or progestogen in women via the administration of oral contraceptives attenuates sex‐related differences in the metaboreflex during isometric handgrip exercise

    High intensity interval training improves liver and adipose tissue insulin sensitivity

    Get PDF
    Objective: Endurance exercise training reduces insulin resistance, adipose tissue inflammation and non-alcoholic fatty liver disease (NAFLD), an effect often associated with modest weight loss. Recent studies have indicated that high-intensity interval training (HIIT) lowers blood glucose in individuals with type 2 diabetes independently of weight loss; however, the organs affected and mechanisms mediating the glucose lowering effects are not known. Intense exercise increases phosphorylation and inhibition of acetyl-CoA carboxylase (ACC) by AMP-activated protein kinase (AMPK) in muscle, adipose tissue and liver. AMPK and ACC are key enzymes regulating fatty acid metabolism, liver fat content, adipose tissue inflammation and insulin sensitivity but the importance of this pathway in regulating insulin sensitivity with HIIT is unknown. Methods: In the current study, the effects of 6 weeks of HIIT were examined using obese mice with serine–alanine knock-in mutations on the AMPK phosphorylation sites of ACC1 and ACC2 (AccDKI) or wild-type (WT) controls. Results: HIIT lowered blood glucose and increased exercise capacity, food intake, basal activity levels, carbohydrate oxidation and liver and adipose tissue insulin sensitivity in HFD-fed WT and AccDKI mice. These changes occurred independently of weight loss or reductions in adiposity, inflammation and liver lipid content. Conclusions: These data indicate that HIIT lowers blood glucose levels by improving adipose and liver insulin sensitivity independently of changes in adiposity, adipose tissue inflammation, liver lipid content or AMPK phosphorylation of ACC

    The silver bullet that wasn’t: Rapid agronomic weed adaptations to glyphosate in North America

    Get PDF
    The rapid adoption of glyphosate-resistant crops at the end of the 20th century caused a simplification of weed management that relied heavily on glyphosate for weed control. However, the effectiveness of glyphosate has diminished. A greater understanding of trends related to glyphosate use will shed new light on weed adaptation to a product that transformed global agriculture. Objectives were to (1) quantify the change in weed control efficacy from postemergence (POST) glyphosate use on troublesome weeds in corn and soybean and (2) determine the extent to which glyphosate preceded by a preemergence (PRE) improved the efficacy and consistency of weed control compared to glyphosate alone. Herbicide evaluation trials from 24 institutions across the United States of America and Canada from 1996 to 2021 were compiled into a single database. Two subsets were created; one with glyphosate applied POST, and the other with a PRE herbicide followed by glyphosate applied POST. Within each subset, mean and variance of control ratings for seven problem weed species were regressed over time for nine US states and one Canadian province. Mean control with POST glyphosate alone decreased over time while variability in control increased. Glyphosate preceded by a labeled PRE herbicide showed little change in mean control or variability in control over time. These results illustrate the rapid adaptation of agronomically important weed species to the paradigm-shifting product glyphosate. Including more diversity in weed management systems is essential to slowing weed adaptation and prolonging the usefulness of existing and future technologies

    The stellar-to-halo mass relation of GAMA galaxies from 100 deg2of KiDS weak lensing data

    Get PDF
    We study the stellar-to-halo mass relation of central galaxies in the range 9.7 5 × 1010h-2M&sun;, the stellar mass increases with halo mass as ˜ {}M_h^{0.25}. The ratio of dark matter to stellar mass has a minimum at a halo mass of 8 × 1011h-1M&sun; with a value of M_h/M_*=56_{-10}^{+16} [h]. We also use the GAMA group catalogue to select centrals and satellites in groups with five or more members, which trace regions in space where the local matter density is higher than average, and determine for the first time the stellar-to-halo mass relation in these denser environments. We find no significant differences compared to the relation from the full sample, which suggests that the stellar-to-halo mass relation does not vary strongly with local density. Furthermore, we find that the stellar-to-halo mass relation of central galaxies can also be obtained by modelling the lensing signal and stellar mass function of satellite galaxies only, which shows that the assumptions to model the satellite contribution in the halo model do not significantly bias the stellar-to-halo mass relation. Finally, we show that the combination of weak lensing with the stellar mass function can be used to test the purity of group catalogues

    The discovAIR project:a roadmap towards the Human Lung Cell Atlas

    Get PDF
    The Human Cell Atlas (HCA) consortium aims to establish an atlas of all organs in the healthy human body at single-cell resolution to increase our understanding of basic biological processes that govern development, physiology and anatomy, and to accelerate diagnosis and treatment of disease. The lung biological network of the HCA aims to generate the Human Lung Cell Atlas as a reference for the cellular repertoire, molecular cell states and phenotypes, and the cell-cell interactions that characterise normal lung homeostasis in healthy lung tissue. Such a reference atlas of the healthy human lung will facilitate mapping the changes in the cellular landscape in disease. The discovAIR project is one of six pilot actions for the HCA funded by the European Commission in the context of the H2020 framework program. DiscovAIR aims to establish the first draft of an integrated Human Lung Cell Atlas, combining single-cell transcriptional and epigenetic profiling with spatially resolving techniques on matched tissue samples, as well as including a number of chronic and infectious diseases of the lung. The integrated Lung Cell Atlas will be available as a resource for the wider respiratory community, including basic and translational scientists, clinical medicine, and the private sector, as well as for patients with lung disease and the interested lay public. We anticipate that the Lung Cell Atlas will be the founding stone for a more detailed understanding of the pathogenesis of lung diseases, guiding the design of novel diagnostics and preventive or curative interventions

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

    Get PDF
    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    A nurse-delivered mental health intervention for obstetric fistula patients in Tanzania: results of a pilot randomized controlled trial

    No full text
    Abstract Background Obstetric fistula has severe psychological consequences, but no evidence-based interventions exist to improve mental health in this population. This pilot trial evaluated a psychological intervention for women receiving surgical care for obstetric fistula. Methods A parallel two-armed pilot RCT was conducted between 2014 and 2016. The intervention was six individual sessions, based on psychological theory and delivered by a nurse facilitator. The study was conducted at a tertiary hospital in Moshi, Tanzania. Women were eligible if they were over age 18 and admitted to the hospital for surgical repair of an obstetric fistula. Sixty participants were randomized to the intervention or standard of care. Surveys were completed at baseline, post-treatment (before discharge), and 3 months following discharge. Standardized scales measured depression, anxiety, traumatic stress, and self-esteem. Feasibility of an RCT was assessed by participation and retention. Feasibility and acceptability of the intervention were assessed by fidelity, attendance, and participant ratings. Potential efficacy was assessed by exploratory linear regression and clinical significance analysis. Results Eighty-five percent met criteria for mental health dysfunction at enrollment. All eligible patients enrolled, with retention 100% post and 73% at 3 months. Participants rated the intervention acceptable and beneficial. There were sharp and meaningful improvements in mental health outcomes over time, with no evidence of differences by condition. Conclusions A nurse-delivered mental health intervention was feasible to implement as part of in-patient clinical care and regarded positively. Mental health treatment in this population is warranted given high level of distress at presentation to care. Trial registration ClinicalTrials.Gov NCT01934075

    Hematopoietic AMPK Beta ß1 reduces mouse adipose tissue macrophage inflammation and insulin resistance in obesity

    No full text
    Individuals who are obese are frequently insulin resistant, putting them at increased risk of developing type 2 diabetes and its associated adverse health conditions. The accumulation in adipose tissue of macrophages in an inflammatory state is a hallmark of obesity-induced insulin resistance. Here, we reveal a role for AMPK ÎČ1 in protecting macrophages from inflammation under high lipid exposure. Genetic deletion of the AMPK ÎČ1 subunit in mice ( referred to herein as ÎČ1–/– mice ) reduced macrophage AMPK activity, acetyl-CoA carboxylase phosphorylation, and mitochondrial content, resulting in reduced rates of fatty acid oxidation. ÎČ1–/– macrophages displayed increased levels of diacylglycerol and markers of inflammation, effects that were reproduced in WT macrophages by inhibiting fatty acid oxidation and, conversely, prevented by pharmacological activation of AMPK ÎČ1–containing complexes. The effect of AMPK ÎČ1 loss in macrophages was tested in vivo by transplantation of bone marrow from WT or ÎČ1–/– mice into WT recipients. When challenged with a high-fat diet, mice that received ÎČ1–/– bone marrow displayed enhanced adipose tissue macrophage inflammation and liver insulin resistance compared with animals that received WT bone marrow. Thus, activation of AMPK ÎČ1 and increasing fatty acid oxidation in macrophages may represent a new therapeutic approach for the treatment of insulin resistance

    Inducible lung epithelial resistance requires multisource reactive oxygen species generation to protect against bacterial infections.

    No full text
    Pneumonia remains a global health threat, in part due to expanding categories of susceptible individuals and increasing prevalence of antibiotic resistant pathogens. However, therapeutic stimulation of the lungs' mucosal defenses by inhaled exposure to a synergistic combination of Toll-like receptor (TLR) agonists known as Pam2-ODN promotes mouse survival of pneumonia caused by a wide array of pathogens. This inducible resistance to pneumonia relies on intact lung epithelial TLR signaling, and inducible protection against viral pathogens has recently been shown to require increased production of epithelial reactive oxygen species (ROS) from multiple epithelial ROS generators. To determine whether similar mechanisms contribute to inducible antibacterial responses, the current work investigates the role of ROS in therapeutically-stimulated protection against Pseudomonas aerugnosa challenges. Inhaled Pam2-ODN treatment one day before infection prevented hemorrhagic lung cytotoxicity and mouse death in a manner that correlated with reduction in bacterial burden. The bacterial killing effect of Pam2-ODN was recapitulated in isolated mouse and human lung epithelial cells, and the protection correlated with inducible epithelial generation of ROS. Scavenging or targeted blockade of ROS production from either dual oxidase or mitochondrial sources resulted in near complete loss of Pam2-ODN-induced bacterial killing, whereas deficiency of induced antimicrobial peptides had little effect. These findings support a central role for multisource epithelial ROS in inducible resistance against a bacterial pathogen and provide mechanistic insights into means to protect vulnerable patients against lethal infections
    corecore