Exercise modulates the insulin-induced translocation of glucose transporters in rat skeletal muscle

AbstractInsulin and acute exercise (45 min of treadmill run) increased glucose uptake into perfused rat hindlimbs 5-fold and 3.2-fold, respectively. Following exercise, insulin treatment resulted in a further increase in glucose uptake. The subcellular distribution of the muscle glucose transporters GLUT-1 and GLUT-4 was determined in plasma membranes and intracellular membranes. Neither exercise nor exercise→ insulin treatment altered the distribution of GLUT-1 transporters in these medmbrane fractions. In contrast, exercise, insulin and exercise→ insulin treatment caused comparable increases in GLUT-4 transporters in the plasma membrane. The results suggest that exercise might limit insulin-induced GLUT-4 recruitment and that following exercise, insulin may alter the intrinsic activity of plasma membrane glucose transporters

High-Temperature Monitoring of Refractory Wall Recession Using Frequency-modulated Continuous-wave (FM-CW) Radar Techniques

Furnaces are among the most crucial components in the glass and metallurgical industry. Nowadays, furnaces are being operated at higher temperatures and for longer periods of time thus increasing the rate of wear on the furnace refractory lining. Consequently, there is a great need for a nondestructive tool that can accurately measure refractory wall thickness at high temperatures. In this paper the utility of a frequency-modulated continuous-wave (FM-CW) radar is investigated for this purpose

The uses and functions of ageing celebrity war reporters

This article starts from the premise that recognition of professional authority and celebrity status depends on the embodiment and performance of field-specific dispositional practices: there’s no such thing as a natural, though we often talk about journalistic instinct as something someone simply has or doesn’t have. Next, we have little control over how we are perceived by peers and publics, and what we think are active positioning or subjectifying practices are in fact, after Bourdieu, revelations of already-determined delegation. The upshot is that two journalists can arrive at diametrically opposed judgements on the basis of observation of the same actions of a colleague, and as individuals we are blithely hypocritical in forming (or reciting) evaluations of the professional identity of celebrities. Nowhere is this starker than in the discourse of age-appropriate behaviour, which this paper addresses using the examples of ‘star’ war reporters John Simpson, Kate Adie and Martin Bell. A certain rough-around-the-edges irreverence is central to dispositional authenticity amongst war correspondents, and for ageing hacks this incorporates gendered attitudes to sex and alcohol as well as indifference to protocol. And yet perceived age-inappropriate sexual behaviour is also used to undermine professional integrity, and the paper ends by outlining the phenomenological context that makes possible this effortless switching between amoral and moralising recognition by peers and audiences alike

The effect of hypoxia and work intensity on insulin resistance in type 2 diabetes

Context:Hypoxia and muscle contraction stimulate glucose transport in vitro. We have previously demonstrated that exercise and hypoxia have an additive effect on insulin sensitivity in type 2 diabetics.Objectives:Our objective was to examine the effects of three different hypoxic/exercise (Hy Ex) trials on glucose metabolism and insulin resistance in the 48 h after acute hypoxia in type 2 diabetics.Design, Participants, and Interventions:Eight male type 2 diabetics completed 60 min of hypoxic [mean (sem) O(2) = ∼14.7 (0.2)%] exercise at 90% of lactate threshold [Hy Ex(60); 49 (1) W]. Patients completed an additional two hypoxic trials of equal work, lasting 40 min [Hy Ex(40); 70 (1) W] and 20 min [Hy Ex(20); 140 (12) W].Main Outcome Measures:Glucose rate of appearance and rate of disappearance were determined using the one-compartment minimal model. Homeostasis models of insulin resistance (HOMA(IR)), fasting insulin resistance index and β-cell function (HOMA(β-cell)) were calculated at 24 and 48 h after trials.Results:Peak glucose rate of appearance was highest during Hy Ex(20) [8.89 (0.56) mg/kg · min, P < 0.05]. HOMA(IR) and fasting insulin resistance index were improved in the 24 and 48 h after Hy Ex(60) and Hy Ex(40) (P < 0.05). HOMA(IR) decreased 24 h after Hy Ex(20) (P < 0.05) and returned to baseline values at 48 h.Conclusions:Moderate-intensity exercise in hypoxia (Hy Ex(60) and Hy Ex(40)) stimulates acute- and moderate-term improvements in insulin sensitivity that were less apparent in Hy Ex(20). Results suggest that exercise duration and not total work completed has a greater influence on acute and moderate-term glucose control in type 2 diabetics

Kinetics of GLUT4 Trafficking in Rat and Human Skeletal Muscle

OBJECTIVE—In skeletal muscle, insulin stimulates glucose transport activity three- to fourfold, and a large part of this stimulation is associated with a net translocation of GLUT4 from an intracellular compartment to the cell surface. We examined the extent to which insulin or the AMP-activated protein kinase activator AICAR can lead to a stimulation of the exocytosis limb of the GLUT4 translocation pathway and thereby account for the net increase in glucose transport activity. RESEARCH DESIGN AND METHODS—Using a biotinylated photoaffinity label, we tagged endogenous GLUT4 and studied the kinetics of exocytosis of the tagged protein in rat and human skeletal muscle in response to insulin or AICAR. Isolated ep-itrochlearis muscles were obtained from male Wistar rats. Vastus lateralis skeletal muscle strips were prepared from open muscle biopsies obtained from six healthy men (age 39 11 years an

Protocol for development of a core outcome set for clinical trials in melasma

INTRODUCTION: Melasma is a pigmentation disorder of the skin. Characterised by brown to gray-brown patches on the face and neck, the condition predominantly affects women and has been associated with pregnancy, hormonal variation and sun exposure. Melasma can be disfiguring and anxiety-provoking, and quality of life is often adversely impacted. Management includes sun protection, laser and energy device therapy, topical and oral skin-bleaching agents and chemical peels. While clinical trials of melasma exist, there is a lack of consistency in reported outcomes, which has been a barrier to the aggregation of data in systematic reviews and meta-analyses. This protocol describes a planned process for development of a minimum set of outcomes (ie, ‘core outcome set’) that should be measured in all clinical trials of melasma. METHODS AND ANALYSIS: An exhaustive list of potential outcomes will be extracted from four sources: (1) systematic literature review of outcomes in clinical trials; (2) semistructured patient interviews; (3) brochures, pamphlets, clinical trial registries, and other published and unpublished sources and documentation; and (4) interviews with non-patient, non-physician stakeholders, including federal regulators, industry scientists and non-physician providers. An international two-round Delphi process will then be performed to identify the outcomes deemed most important to patients and physicians. Subsequently, a consensus meeting will be convened to review and process the results, and to vote on a final set of core outcomes. ETHICS AND DISSEMINATION: Ethics approval was provided by the Northwestern University Institutional Review Board (protocol ID: STU00201637). This study is registered with both the Core Outcome Measures in Effectiveness Trials and Cochrane Skin-Core Outcome Set Initiative initiatives, and this protocol is in accordance with the guidelines for protocol development of both groups. All findings from the study described in this protocol will be disseminated to all stakeholders involved in the development process and will be submitted for publication in peer-reviewed journals. PROSPERO REGISTRATION NUMBER: CRD42020214189