643 research outputs found

    Transgenic Adipose-specific Expression of the Nuclear Receptor RORα Drives a Striking Shift in Fat Distribution and Impairs Glycemic Control.

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    RORα is a member of the nuclear receptor (NR) superfamily and analysis of the (global) RORα-deficient mouse model revealed this NR has a role in glycemic control and fat deposition. Therefore, we generated an adipose-specific RORα 'gain of function' mouse model under the control of the fatty acid binding protein 4 (FABP4) promoter to elucidate the function of RORα in adipose tissue. The Tg-FABP4-RORα4 mice demonstrated a shift in fat distribution to non-adipose tissues when challenged with a high fat diet (HFD). Specifically, we observed a subcutaneous lipodystrophy, accompanied by hepatomegaly (fatty liver/mild portal fibrosis) and splenomegaly; in a background of decreased weight gain and total body fat after HFD. Moreover, we observed significantly higher fasting blood glucose and impaired clearance of glucose in Tg-FABP4-RORα4 mice. Genome wide expression and qPCR profiling analysis identified: (i) subcutaneous adipose specific decreases in the expression of genes involved in fatty acid biosynthesis, lipid droplet expansion and glycemic control, and (ii) the fibrosis pathway as the most significant pathway [including dysregulation of the collagen/extracellular matrix (ECM) pathways] in subcutaneous adipose and liver. The pathology presented in the Tg-FABP4-RORα4 mice is reminiscent of human metabolic disease (associated with aberrant ECM expression) highlighting the therapeutic potential of this NR

    Putative regulatory sites unraveled by network-embedded thermodynamic analysis of metabolome data

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    As one of the most recent members of the omics family, large-scale quantitative metabolomics data are currently complementing our systems biology data pool and offer the chance to integrate the metabolite level into the functional analysis of cellular networks. Network-embedded thermodynamic analysis (NET analysis) is presented as a framework for mechanistic and model-based analysis of these data. By coupling the data to an operating metabolic network via the second law of thermodynamics and the metabolites' Gibbs energies of formation, NET analysis allows inferring functional principles from quantitative metabolite data; for example it identifies reactions that are subject to active allosteric or genetic regulation as exemplified with quantitative metabolite data from Escherichia coli and Saccharomyces cerevisiae. Moreover, the optimization framework of NET analysis was demonstrated to be a valuable tool to systematically investigate data sets for consistency, for the extension of sub-omic metabolome data sets and for resolving intracompartmental concentrations from cell-averaged metabolome data. Without requiring any kind of kinetic modeling, NET analysis represents a perfectly scalable and unbiased approach to uncover insights from quantitative metabolome data

    RORα and 25-Hydroxycholesterol Crosstalk Regulates Lipid Droplet Homeostasis in Macrophages.

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    Nuclear hormone receptors have important roles in the regulation of metabolic and inflammatory pathways. The retinoid-related orphan receptor alpha (Rorα)-deficient staggerer (sg/sg) mice display several phenotypes indicative of aberrant lipid metabolism, including dyslipidemia, and increased susceptibility to atherosclerosis. In this study we demonstrate that macrophages from sg/sg mice have increased ability to accumulate lipids and accordingly exhibit larger lipid droplets (LD). We have previously shown that BMMs from sg/sg mice have significantly decreased expression of cholesterol 25-hydroxylase (Ch25h) mRNA, the enzyme that produces the oxysterol, 25-hydroxycholesterol (25HC), and now confirm this at the protein level. 25HC functions as an inverse agonist for RORα. siRNA knockdown of Ch25h in macrophages up-regulates Vldlr mRNA expression and causes increased accumulation of LDs. Treatment with physiological concentrations of 25HC in sg/sg macrophages restored lipid accumulation back to normal levels. Thus, 25HC and RORα signify a new pathway involved in the regulation of lipid homeostasis in macrophages, potentially via increased uptake of lipid which is suggested by mRNA expression changes in Vldlr and other related genes

    Seroprevalence and risk factors of Besnoitia besnoiti infection in Korean cattle – short communication

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    Besnoitia besnoiti is an obligate intracellular parasite that is transmitted by direct contact or via mechanical transmission by flies as vectors. Besnoitiosis causes economic losses in the cattle industry and is regarded as a re-emerging disease in Europe. This study evaluated the seroprevalence of B. besnoiti in Korean cattle using a commercial ELISA kit. Among 558 serum samples, 19 (3.4%) tested seropositive for B. besnoiti. The statistically significant risk factors included age (≄ 2 years), sex (castrated males), and region (lower latitudes) (P < 0.05). The overall seroprevalence suggested a wide distribution of B. besnoiti infection in cattle reared in Korea. Thus, the practice of intensive cattle husbandry and the regionally different seroprevalence of B. besnoiti infection in cattle in Korea warrant routine monitoring and vector control to reduce economical losses due to bovine besnoitiosis in the country

    Pattern of childhood and adolescent malignancies at a tertiary health institution in South-east Nigeria : A ten year study

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    Background: Cancer remains a major cause of death in children and adolescents, and differs in adults in nature, distribution and prognosis1. A culture of case documentation is lacking in our environment and many cases go unreported.Study objectives: To document the pattern of childhood and adolescent malignancies at a tertiary health institution in south-east Nigeria over a ten year period (January 2004 to December 2013)Methodology: Details of all children and adolescents aged 18 years and below treated for malignancy were extracted from the cancer registry and the records unit of the histopathology department for the period beginning at January 2004 to December 2013 at Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Nigeria. Information retrieved was verified against the hospital admission register, as well as the medical and histopathology records for all cancer patients over the period of interest.Results: Eighty-five cases of childhood and adolescent malignancy were treated at NAUTH, Nnewi between January 2004 and December 2013. Median age of the study population was 9years, with a range of 0.1– 18years, more males (56.50%) than females (43.50%). Commonest tumours were the Lymphomas (11.76%) comprising Non- Hodgkin’s lymphoma (80%), Hodgkin’s lymphoma (10%) and Large-cell lymphoma (10%), the Leukaemias (11.76%) comprising Acute myeloblastic leukaemia (80%) and Acute lymphoblastic leukaemia (20%). Others were Rhabdomyosarcoma (11.76%), Nephroblastoma (11.76%), Retinoblastoma (5.88%), Ovarian tumours (4.71%), the Soft tissue sarcomas-excluding rhabdomyosarcoma (3.53%) and Osteogenic sarcoma (3.35%)’.Conclusion: Study findings suggest that lymphoma, leukaemia, rhabdomyosarcoma and nephroblastoma are the commonest childhood and adolescent malignancies in south-east Nigeria.Keywords: Childhood, Adolescent, Malignanc

    Enhanced Supersymmetry of Nonrelativistic ABJM Theory

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    We study the supersymmetry enhancement of nonrelativistic limits of the ABJM theory for Chern-Simons level k=1,2k=1,2. The special attention is paid to the nonrelativistic limit (known as `PAAP' case) containing both particles and antiparticles. Using supersymmetry transformations generated by the monopole operators, we find additional 2 kinematical, 2 dynamical, and 2 conformal supercharges for this case. Combining with the original 8 kinematical supercharges, the total number of supercharges becomes maximal: 14 supercharges, like in the well-known PPPP limit. We obtain the corresponding super Schr\"odinger algebra which appears to be isomorphic to the one of the PPPP case. We also discuss the role of monopole operators in supersymmetry enhancement and partial breaking of supersymmetry in nonrelativistic limit of the ABJM theory.Comment: 22 pages, references added, version to appear in JHE

    Fractal fronts of diffusion in microgravity

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    Spatial scale invariance represents a remarkable feature of natural phenomena. A ubiquitous example is represented by miscible liquid phases undergoing diffusion. Theory and simulations predict that in the absence of gravity diffusion is characterized by long-ranged algebraic correlations. Experimental evidence of scale invariance generated by diffusion has been limited, because on Earth the development of long-range correlations is suppressed by gravity. Here we report experimental results obtained in microgravity during the flight of the FOTON M3 satellite. We find that during a diffusion process a dilute polymer solution exhibits scale-invariant concentration fluctuations with sizes ranging up to millimetres, and relaxation times as large as 1,000 s. The scale invariance is limited only by the finite size of the sample, in agreement with recent theoretical predictions. The presence of such fluctuations could possibly impact the growth of materials in microgravity

    Association between erythrocyte Na+K+-ATPase activity and some blood lipids in type 1 diabetic patients from Lagos, Nigeria

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    <p>Abstract</p> <p>Background</p> <p>Altered levels of erythrocyte Na<sup>+</sup>K<sup>+</sup>-ATPase, atherogenic and anti-atherogenic lipid metabolites have been implicated in diabetic complications but their pattern of interactions remains poorly understood.</p> <p>This study evaluated this relationship in Nigerian patients with Type 1 diabetes mellitus.</p> <p>Methods</p> <p>A total of 34 consented Type 1 diabetic patients and age -matched 27 non-diabetic controls were enrolled. Fasting plasma levels of total cholesterol, triglycerides and HDL-cholesterol were determined spectrophotometrically and LDL-cholesterol estimated using Friedewald formula. Total protein content and Na+K+-ATPase activity were also determined spectrophotometrically from ghost erythrocyte membrane prepared by osmotic lysis.</p> <p>Results</p> <p>Results indicate significant (P < 0.05) reduction in Na<sup>+</sup>K<sup>+</sup>-ATPase activity in the Type 1 diabetic patients (0.38 ± 0.08 vs. 0.59 ± 0.07 uM Pi/mgprotein/h) compared to the control but with greater reduction in the diabetic subgroup with poor glycemic control (n = 20) and in whom cases of hypercholesterolemia (8.8%), hypertriglyceridemia (2.9%) and elevated LDL-cholesterol (5.9% each) were found. Correlation analyses further revealed significant (P < 0.05) inverse correlations [r = -(0.708-0.797] between all the atherogenic lipid metabolites measured and Na<sup>+</sup>K<sup>+</sup>-ATPase in this subgroup contrary to group with good glycemic control or non-diabetic subjects in which significant (P < 0.05) Na<sup>+</sup>K<sup>+</sup>-ATPase and HDL-C association were found (r = 0.427 - 0.489). The Na<sup>+</sup>K<sup>+</sup>-ATPase from the diabetic patients also exhibited increased sensitivity to digoxin and alterations in kinetic constants Vmax and Km determined by glycemic status of the patients.</p> <p>Conclusion</p> <p>It can be concluded that poor glycemic control evokes greater reduction in erythrocyte Na<sup>+</sup>K<sup>+</sup>-ATPase activity and promote enzyme-blood atherogenic lipid relationships in Type 1 diabetic Nigerian patients.</p

    Molecular Characterization and Phylogenetic Study of Coxsackievirus A24v Causing Outbreaks of Acute Hemorrhagic Conjunctivitis (AHC) in Brazil

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    Coxsackievirus A24 variant (CA24v) is the most prevalent viral pathogen associated with acute hemorrhagic conjunctivitis (AHC) outbreaks. Sixteen years after its first outbreak in Brazil, this agent reemerged in 2003 in Brazil, spread to nearly all states and caused outbreaks until 2005. In 2009, a new outbreak occurred in the northeast region of the country. In this study, we performed a viral isolation in cell culture and characterized clinical samples collected from patients presenting symptoms during the outbreak of 2005 in VitĂłria, EspĂ­rito Santo State (ES) and the outbreak of 2009 in Recife, Pernambuco State (PE). We also performed a phylogenetic analysis of worldwide strains and all meaningful Brazilian isolates since 2003.Sterile cotton swabs were used to collect eye discharges, and all 210 clinical samples were used to inoculate cell cultures. Cytopathic effects in HEp-2 cells were seen in 58 of 180 (32%) samples from VitĂłria and 3 of 30 (10%) samples from Recife. Phylogenetic analysis based on a fragment of the VP1 and 3C gene revealed that the CA24v causing outbreaks in Brazil during the years 2003, 2004 and 2005 evolved from Asian isolates that had caused the South Korean outbreak of AHC during the summer of 2002. However, the 2009 outbreak of AHC in Pernambuco was originated from the reintroduction of a new CA24v strain that was circulating during 2007 in Asia, where CA24v outbreaks has been continuously reported since 1970.This study is the first phylogenetic analysis of AHC outbreaks caused by CA24v in Brazil. The results showed that Asian strains of CA24v were responsible for the outbreaks since 1987 and were independently introduced to Brazil in 2003 and 2009. Phylogenetic analysis of complete VP1 gene is a useful tool for studying the epidemiology of enteroviruses associated with outbreaks
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