188 research outputs found

    New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk.

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    Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes

    Evolution of the knowledge economy: a historical perspective with an application to the case of Europe

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    The goal of the article is to explore the evolution of original concept of knowledge economy based on science intensive production sectors toward service type economies which significantly changed the role of scientific research and technological innovation for economic growth. The paper argues that this transition is due not only to the structural changes in global production, but the theoretical evolution and aradigmatic shift of the concept of “knowledge economy” in general and “knowledge” in particular has played a significant role. The paper examines the different interpretation of knowledge within new types of intangible economies (e.g., new/Internet, weightless, service, creative, cultural economies) where knowledge is perceived to be generated not as a product of scientific research but as a service or creative activity and critically examined the role of scientific research in a service led knowledge economy. Additionally the paper argue how these phenomena, which marked the global economy in the last decades, enable the transition of the standard concept of knowledge economy originated from industrial production and manufacturing to a knowledge economy equalized with various types of expanding intangible economies, primarily those based on service and creative industries

    Differential effects of glucagon-like peptide-1 receptor agonists on heart rate

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    Abstract While glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are known to increase heart rate (HR), it is insufficiently recognized that the extent varies greatly between the various agonists and is affected by the assessment methods employed. Here we review published data from 24-h time-averaged HR monitoring in healthy individuals and subjects with type 2 diabetes mellitus (T2DM) treated with either short-acting GLP-1 RAs, lixisenatide or exenatide, or long-acting GLP-1 RAs, exenatide LAR, liraglutide, albiglutide, or dulaglutide (N\ua0=\ua01112; active-treatment arms). HR effects observed in two independent head-to-head trials of lixisenatide and liraglutide (N\ua0=\ua0202; active-treatment arms) are also reviewed. Short-acting GLP-1 RAs, exenatide and lixisenatide, are associated with a transient (1\u201312\ua0h) mean placebo- and baseline-adjusted 24-h HR increase of 1\u20133\ua0beats per minute (bpm). Conversely, long-acting GLP-1 RAs are associated with more pronounced increases in mean 24-h HR; the highest seen with liraglutide and albiglutide at 6\u201310\ua0bpm compared with dulaglutide and exenatide LAR at 3\u20134\ua0bpm. For both liraglutide and dulaglutide, HR increases were recorded during both the day and at night. In two head-to-head comparisons, a small, transient mean increase in HR from baseline was observed with lixisenatide; liraglutide induced a substantially greater increase that remained significantly elevated over 24\ua0h. The underlying mechanism for increased HR remains to be elucidated; however, it could be related to a direct effect at the sinus node and/or stimulation of the sympathetic nervous system, with this effect related to the duration of action of the respective GLP-1 RAs. In conclusion, this review indicates that the effects on HR differ within the class of GLP-1 RAs: short-acting GLP-1 RAs are associated with a modest and transient HR increase before returning to baseline levels, while some long-acting GLP-1 RAs are associated with a more pronounced and sustained increase during the day and night. Findings from recently completed trials indicate that a GLP-1 RA-induced increase in HR, regardless of magnitude, does not present an increased cardiovascular risk for subjects with T2DM, although a pronounced increase in HR may be associated with adverse clinical outcomes in those with advanced heart failure

    Reproducibility of histopathological findings in experimental pathology of the mouse: a sorry tail

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    Reproducibility of in vivo\textit{in vivo} research using the mouse as a model organism depends on many factors, including experimental design, strain or stock, experimental protocols, and methods of data evaluation. Gross and histopathology are often the endpoints of such research and there is increasing concern about the accuracy and reproducibility of diagnoses in the literature. To reproduce histopathological results, the pathology protocol, including necropsy methods and slide preparation, should be followed by interpretation of the slides by a pathologist familiar with reading mouse slides and familiar with the consensus medical nomenclature used in mouse pathology. Likewise, it is important that pathologists are consulted as reviewers of manuscripts where histopathology is a key part of the investigation. The absence of pathology expertise in planning, executing and reviewing in vivo\textit{in vivo} research using mice leads to questionable pathology-based findings and conclusions from studies, even in high-impact journals. We discuss the various aspects of this problem, give some examples from the literature and suggest solutions.This work was supported in part by US National Institutes of Health grants R01 AR049288, CA089713 and R21 AR063781 (to J.P.S.) and by The Warden and Fellows of Robinson College, Cambridge (to P.N.S.)

    Synergistic growth inhibition by Iressa and Rapamycin is modulated by VHL mutations in renal cell carcinoma

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    Epidermal growth factor receptor (EGFR) and tumour growth factor alpha (TGFα) are frequently overexpressed in renal cell carcinoma (RCC) yet responses to single-agent EGFR inhibitors are uncommon. Although von Hippel–Lindau (VHL) mutations are predominant, RCC also develops in individuals with tuberous sclerosis (TSC). Tuberous sclerosis mutations activate mammalian target of rapamycin (mTOR) and biochemically resemble VHL alterations. We found that RCC cell lines expressed EGFR mRNA in the near-absence of other ErbB family members. Combined EGFR and mTOR inhibition synergistically impaired growth in a VHL-dependent manner. Iressa blocked ERK1/2 phosphorylation specifically in wt-VHL cells, whereas rapamycin inhibited phospho-RPS6 and 4E-BP1 irrespective of VHL. In contrast, phospho-AKT was resistant to these agents and MYC translation initiation (polysome binding) was similarly unaffected unless AKT was inhibited. Primary RCCs vs cell lines contained similar amounts of phospho-ERK1/2, much higher levels of ErbB-3, less phospho-AKT, and no evidence of phospho-RPS6, suggesting that mTOR activity was reduced. A subset of tumours and cell lines expressed elevated eIF4E in the absence of upstream activation. Despite similar amounts of EGFR mRNA, cell lines (vs tumours) overexpressed EGFR protein. In the paired cell lines, PRC3 and WT8, EGFR protein was elevated post-transcriptionally in the VHL mutant and EGF-stimulated phosphorylation was prolonged. We propose that combined EGFR and mTOR inhibitors may be useful in the subset of RCCs with wt-VHL. However, apparent differences between primary tumours and cell lines require further investigation

    Pharmacology and therapeutic implications of current drugs for type 2 diabetes mellitus

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    Type 2 diabetes mellitus (T2DM) is a global epidemic that poses a major challenge to health-care systems. Improving metabolic control to approach normal glycaemia (where practical) greatly benefits long-term prognoses and justifies early, effective, sustained and safety-conscious intervention. Improvements in the understanding of the complex pathogenesis of T2DM have underpinned the development of glucose-lowering therapies with complementary mechanisms of action, which have expanded treatment options and facilitated individualized management strategies. Over the past decade, several new classes of glucose-lowering agents have been licensed, including glucagon-like peptide 1 receptor (GLP-1R) agonists, dipeptidyl peptidase 4 (DPP-4) inhibitors and sodium/glucose cotransporter 2 (SGLT2) inhibitors. These agents can be used individually or in combination with well-established treatments such as biguanides, sulfonylureas and thiazolidinediones. Although novel agents have potential advantages including low risk of hypoglycaemia and help with weight control, long-term safety has yet to be established. In this Review, we assess the pharmacokinetics, pharmacodynamics and safety profiles, including cardiovascular safety, of currently available therapies for management of hyperglycaemia in patients with T2DM within the context of disease pathogenesis and natural history. In addition, we briefly describe treatment algorithms for patients with T2DM and lessons from present therapies to inform the development of future therapies

    Can medical therapy mimic the clinical efficacy or physiological effects of bariatric surgery?

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    The number of bariatric surgical procedures performed has increased dramatically. This review discusses the clinical and physiological changes, and in particular, the mechanisms behind weight loss and glycaemic improvements, observed following the gastric bypass, sleeve gastrectomy and gastric banding bariatric procedures. The review then examines how close we are to mimicking the clinical or physiological effects of surgery through less invasive and safer modern interventions that are currently available for clinical use. These include dietary interventions, orlistat, lorcaserin, phentermine/topiramate, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, pramlintide, dapagliflozin, the duodenal–jejunal bypass liner, gastric pacemakers and gastric balloons. We conclude that, based on the most recent trials, we cannot fully mimic the clinical or physiological effects of surgery; however, we are getting closer. A ‘medical bypass' may not be as far in the future as we previously thought, as the physician's armamentarium against obesity and type 2 diabetes has recently got stronger through the use of specific dietary modifications, novel medical devices and pharmacotherapy. Novel therapeutic targets include not only appetite but also taste/food preferences, energy expenditure, gut microbiota, bile acid signalling, inflammation, preservation of β-cell function and hepatic glucose output, among others. Although there are no magic bullets, an integrated multimodal approach may yield success. Non-surgical interventions that mimic the metabolic benefits of bariatric surgery, with a reduced morbidity and mortality burden, remain tenable alternatives for patients and health-care professionals

    The evolving place of incretin-based therapies in type 2 diabetes

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    Treatment options for type 2 diabetes based on the action of the incretin hormone glucagon-like peptide-1 (GLP-1) were first introduced in 2005. These comprise the injectable GLP-1 receptor agonists solely acting on the GLP-1 receptor on the one hand and orally active dipeptidyl-peptidase inhibitors (DPP-4 inhibitors) raising endogenous GLP-1 and other hormone levels by inhibiting the degrading enzyme DPP-4. In adult medicine, both treatment options are attractive and more commonly used because of their action and safety profile. The incretin-based therapies stimulate insulin secretion and inhibit glucagon secretion in a glucose-dependent manner and carry no intrinsic risk of hypoglycaemia. GLP-1 receptor agonists allow weight loss, whereas DPP-4 inhibitors are weight neutral. This review gives an overview of the mechanism of action and the substances and clinical data available
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