46 research outputs found

    Insulin Resistance and Altered Systemic Glucose Metabolism in Mice Lacking Nur77

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    OBJECTIVE: Nur77 is an orphan nuclear receptor with pleotropic functions. Previous studies have identified Nur77 as a transcriptional regulator of glucose utilization genes in skeletal muscle and gluconeogenesis in liver. However, the net functional impact of these pathways is unknown. To examine the consequence of Nur77 signaling for glucose metabolism in vivo, we challenged Nur77 null mice with high-fat feeding. RESEARCH DESIGN AND METHODS: Wild-type and Nur77 null mice were fed a high-fat diet (60% calories from fat) for 3 months. We determined glucose tolerance, tissue-specific insulin sensitivity, oxygen consumption, muscle and liver lipid content, muscle insulin signaling, and expression of glucose and lipid metabolism genes. RESULTS: Mice with genetic deletion of Nur77 exhibited increased susceptibility to diet-induced obesity and insulin resistance. Hyperinsulinemic-euglycemic clamp studies revealed greater high-fat diet–induced insulin resistance in both skeletal muscle and liver of Nur77 null mice compared with controls. Loss of Nur77 expression in skeletal muscle impaired insulin signaling and markedly reduced GLUT4 protein expression. Muscles lacking Nur77 also exhibited increased triglyceride content and accumulation of multiple even-chained acylcarnitine species. In the liver, Nur77 deletion led to hepatic steatosis and enhanced expression of lipogenic genes, likely reflecting the lipogenic effect of hyperinsulinemia. CONCLUSIONS: Collectively, these data demonstrate that loss of Nur77 influences systemic glucose metabolism and highlight the physiological contribution of muscle Nur77 to this regulatory pathway.National Institutes of Health (HD-00850, DK-081683-01, DK-30425, HL030568); American Diabetes Associatio

    The Future of American Sentencing: A National Roundtable on Blakely

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    In the wake of the dramatic Supreme Court decision in Blakely v. Washington, Stanford Law School convened an assembly of the most eminent academic and professional sentencing experts in the country to jointly assess the meaning of the decision and its implications for federal and state sentencing reform. The event took place on October 8 and 9, just a few months after Blakely came down and the very week that the Supreme Court heard the arguments in United States v. Booker and United States v. Fanfan, the cases that will test Blakely\u27s application to the Federal Sentencing Guidelines. Thus the Roundtable offered these experts an intellectual breathing space at a crucial point in American criminal law. The event was built around six sessions, with shifting panels of participants doing brief presentations on the subject of the session, and with others then joining in the discussion. We are pleased that FSR is able to publish this version of the proceedings of the event-a condensed and edited transcript of the sessions

    Male-Mediated Gene Flow in Patrilocal Primates

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    BACKGROUND: Many group-living species display strong sex biases in dispersal tendencies. However, gene flow mediated by apparently philopatric sex may still occur and potentially alters population structure. In our closest living evolutionary relatives, dispersal of adult males seems to be precluded by high levels of territoriality between males of different groups in chimpanzees, and has only been observed once in bonobos. Still, male-mediated gene flow might occur through rare events such as extra-group matings leading to extra-group paternity (EGP) and female secondary dispersal with offspring, but the extent of this gene flow has not yet been assessed. METHODOLOGY/PRINCIPAL FINDINGS: Using autosomal microsatellite genotyping of samples from multiple groups of wild western chimpanzees (Pan troglodytes verus) and bonobos (Pan paniscus), we found low genetic differentiation among groups for both males and females. Characterization of Y-chromosome microsatellites revealed levels of genetic differentiation between groups in bonobos almost as high as those reported previously in eastern chimpanzees, but lower levels of differentiation in western chimpanzees. By using simulations to evaluate the patterns of Y-chromosomal variation expected under realistic assumptions of group size, mutation rate and reproductive skew, we demonstrate that the observed presence of multiple and highly divergent Y-haplotypes within western chimpanzee and bonobo groups is best explained by successful male-mediated gene flow. CONCLUSIONS/SIGNIFICANCE: The similarity of inferred rates of male-mediated gene flow and published rates of EGP in western chimpanzees suggests this is the most likely mechanism of male-mediated gene flow in this subspecies. In bonobos more data are needed to refine the estimated rate of gene flow. Our findings suggest that dispersal patterns in these closely related species, and particularly for the chimpanzee subspecies, are more variable than previously appreciated. This is consistent with growing recognition of extensive behavioral variation in chimpanzees and bonobos

    Malingering and Secondary Gain in the Afghanistan and Iraq Conflicts (.pdf)

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    Functional or non-organic visual loss (NOVL) is defined as a loss or decrease in visual acuity or visual field range with no identifiable organic cause. NOVL can be a difficult diagnosis to make and requires a high index of suspicion. This can be especially difficult in the setting of true organic pathology, as was the experience with several patients presenting to an Ophthalmology clinic after sustaining either ocular or non-ocular injuries. This case series examines several such patients with NOVL that were either injured or developed an ocular condition while serving in Iraq or Afghanistan. The aim of this series is to provide a review of several possible presentations of NOVL and the various modalities that the ophthalmologist can use to arrive at a diagnosis of NOVL

    Patient-facing Technology for Identification of COPD in Primary Care

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    The proliferation of mobile devices and emergence of interoperable ‘mHealth’ apps is accelerating development and deployment of patient-facing risk assessments in primary care. The present study describes a user-centered design and an agile development approach to creation of an app for assessing lungfunction as part of a randomized controlled trial for the   dentification of chronic obstructive lung disease in primary care. Seventeen patients recruited from a hospital-based, ambulatory family medicine clinic agreed to be videotaped while using the app, Lung Age, on a first-generation iPad prior to their providerencounter. Subsequently, participants were interviewed using a semi-structured interview guide upon exiting their medical visit. Observational data indicated that participants took advantage of the portability and flexibility of the tablet device in the exam room to engage with the Lung Age app with the optionto share and discuss their results with their providers. Results from the semistructured interviews indicated that participants perceived the Lung Age app as intuitive and easy to use. These results demonstrate that tablet computers and mHealth apps can be used to deploy acceptable and useable electronic risk assessments in primary care settings. Future research focused on the impact and outcomes of patient-centered, mHealth apps for risk screening in primary care is warranted

    Effects of diltiazem on phosphate metabolism in ischemic and reperfused myocardium using phosphorus31 nuclear magnetic resonance spectroscopy in vivo

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    Diltiazem may provide a protective effect to ischemic and reperfused myocardium through preservation of high-energy phosphate metabolism. To test this hypothesis, rabbits had a 1.3 cm solenoidal coil placed over the myocardium to be rendered ischemic. Data were acquired with a 22 cm bore nuclear magnetic resonance spectrometer at 2.0 T. Animals were treated with diltiazem (200 [mu]g/kg intravenous bolus of drug followed by a 15 [mu]g/kg/min continuous intravenous infusion, n = 10) or by an equal volume of saline (n = 6). The left circumflex artery was occluded and reperfused using a reversible snare while electrocardiogram-gated spectra were accumulated. Levels of phosphocreatine were decreased during occlusion in both groups; however, this decrease was attenuated in the diltiazem treated animals compared to control (in relative percent area: 7.8 +/- 1.0 to 2.5 +/- 0.5, p p p p p = NS). During ischemia there was a trend toward attenuation of intracellular acidosis in the diltiazem group; however, this trend did not reach statistical significance. These data indicate that diltiazem provides a protective effect on myocardial high-energy phosphate metabolism during regional ischemia and reperfusion in the intact animal.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28238/1/0000691.pd

    Non-organic Vision Loss in the Afghanistan and Iraq Conflicts

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    © This article is not subject to U.S. copyright law. Non-organic visual loss (NOVL), defined as a decrease in visual acuity or field without an identifiable organic cause, can be challenging to diagnose, especially in patients whose NOVL is superimposed on some component of true organic pathology. Exposure to combat puts soldiers at risk of emotional distress and physical trauma, which can contribute to the development of NOVL with conversion disorder or malingering. This case series describes six patients with NOVL who sustained ocular or non-ocular injuries while serving in combat operations in Iraq and Afghanistan, and highlights diagnostic pearls and components of inter-disciplinary management in the unique military context

    The Orphan Nuclear Receptor Nur77 Is a Determinant of Myofiber Size and Muscle Mass in Mice

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    We previously showed that the orphan nuclear receptor Nur77 (Nr4a1) plays an important role in the regulation of glucose homeostasis and oxidative metabolism in skeletal muscle. Here, we show using both gain- and loss-of-function models that Nur77 is also a regulator of muscle growth in mice. Transgenic expression of Nur77 in skeletal muscle in mice led to increases in myofiber size. Conversely, mice with global or muscle-specific deficiency in Nur77 exhibited reduced muscle mass and myofiber size. In contrast to Nur77 deficiency, deletion of the highly related nuclear receptor NOR1 (Nr4a3) had minimal effect on muscle mass and myofiber size. We further show that Nur77 mediates its effects on muscle size by orchestrating transcriptional programs that favor muscle growth, including the induction of insulin-like growth factor 1 (IGF1), as well as concomitant downregulation of growth-inhibitory genes, including myostatin, Fbxo32 (MAFbx), and Trim63 (MuRF1). Nur77-mediated increase in IGF1 led to activation of the Akt-mTOR-S6K cascade and the inhibition of FoxO3a activity. The dependence of Nur77 on IGF1 was recapitulated in primary myoblasts, establishing this as a cell-autonomous effect. Collectively, our findings identify Nur77 as a novel regulator of myofiber size and a potential transcriptional link between cellular metabolism and muscle growth
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