356 research outputs found

    Inflammatory monocytes require type I interferon receptor signaling to activate NK cells via IL-18 during a mucosal viral infection

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    The requirement of type I interferon (IFN) for natural killer (NK) cell activation in response to viral infection is known, but the underlying mechanism remains unclear. Here, we demonstrate that type I IFN signaling in inflammatory monocytes, but not in dendritic cells (DCs) or NK cells, is essential for NK cell function in response to a mucosal herpes simplex virus type 2 (HSV-2) infection. Mice deficient in type I IFN signaling, Ifnar(-/-) and Irf9(-/-) mice, had significantly lower levels of inflammatory monocytes, were deficient in IL-18 production, and lacked NK cell-derived IFN-gamma. Depletion of inflammatory monocytes, but not DCs or other myeloid cells, resulted in lower levels of IL-18 and a complete abrogation of NK cell function in HSV-2 infection. Moreover, this resulted in higher susceptibility to HSV-2 infection. Although Il18(-/-) mice had normal levels of inflammatory monocytes, their NK cells were unresponsive to HSV-2 challenge. This study highlights the importance of type I IFN signaling in inflammatory monocytes and the induction of the early innate antiviral response

    Retroviral Interferon- α Gene Transfer Potentiates Paclitaxel against Ovarian Cancer Cells

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    Objective: To analyze the cytotoxic effects of paclitaxel following introduction of the retroviral interferon- α (IFN- α) gene into epithelial ovarian cancer cells.Design: Experimental molecular study.Setting: University hospital research center. Sample: Epithelial ovarian cancer cell lines OV-2774 and SKOV3. Empty vector was used as control.Methods: The cytotoxic effects of paclitaxel on ovarian cancer cells were studied prior to and after transfection with the retrovirus-mediated inteferon- α gene. RT/PCR of the interferon gene, cell survival and cell death were analyzed to assess retroviral interferon- α gene expression after transfection.Results: Paclitaxel inhibited cell growth in a dose dependent manner with half maximal inhibitory concentration (IC50) of 7.5 ng/ml. Retroviral inteferon- α gene transfer-transduced cells potentiated paclitaxel response against both ovarian cancer cell lines by 68%.Conclusion:  Retrovirus-mediated IFN- α gene transfer enhanced paclitaxel cytotoxicity on ovarian cancer cells. Retroviral IFN- α gene transfer in combination with paclitaxel may have significant clinical utility for the treatment of epithelial ovarian cancers

    Effects of exenatide twice daily versus sitagliptin on 24-h glucose, glucoregulatory and hormonal measures: a randomized, double-blind, crossover study

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    Aim: To compare exenatide and sitagliptin glucose and glucoregulatory measures in subjects with type 2 diabetes

    Expression of Steroid Receptor RNA Activator 1 (SRA1) in the Adipose Tissue Is Associated with TLRs and IRFs in Diabesity

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    Steroid receptor RNA activator gene (SRA1) emerges as a player in pathophysiological responses of adipose tissue (AT) in metabolic disorders such as obesity and type 2 diabetes (T2D). We previously showed association of the AT SRA1 expression with inflammatory cytokines/chemokines involved in metabolic derangement. However, the relationship between altered adipose expression of SRA1 and the innate immune Toll-like receptors (TLRs) as players in nutrient sensing and metabolic inflammation as well as their downstream signaling partners, including interferon regulatory factors (IRFs), remains elusive. Herein, we investigated the association of AT SRA1 expression with TLRs, IRFs, and other TLR-downstream signaling mediators in a cohort of 108 individuals, classified based on their body mass index (BMI) as persons with normal-weight (N = 12), overweight (N = 32), and obesity (N = 64), including 55 with and 53 without T2D. The gene expression of SRA1, TLRs-2,3,4,7,8,9,10 and their downstream signaling mediators including IRFs-3,4,5, myeloid differentiation factor 88 (MyD88), interleukin-1 receptor-associated kinase 1 (IRAK1), and nuclear factor-κB (NF-κB) were determined using qRT-PCR and SRA1 protein expression was determined by immunohistochemistry. AT SRA1 transcripts’ expression was significantly correlated with TLRs-3,4,7, MyD88, NF-κB, and IRF5 expression in individuals with T2D, while it associated with TLR9 and TRAF6 expression in all individuals, with/without T2D. SRA1 expression associated with TLR2, IRAK1, and IRF3 expression only in individuals with obesity, regardless of diabetes status. Furthermore, TLR3/TLR7/IRAK1 and TLR3/TLR9 were identified as independent predictors of AT SRA1 expression in individuals with obesity and T2D, respectively. Overall, our data demonstrate a direct association between the AT SRA1 expression and the TLRs together with their downstream signaling partners and IRFs in individuals with obesity and/or T2D

    Suppression of Phase Separation in LiFePO4 Nanoparticles During Battery Discharge

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    Using a novel electrochemical phase-field model, we question the common belief that LixFePO4 nanoparticles separate into Li-rich and Li-poor phases during battery discharge. For small currents, spinodal decomposition or nucleation leads to moving phase boundaries. Above a critical current density (in the Tafel regime), the spinodal disappears, and particles fill homogeneously, which may explain the superior rate capability and long cycle life of nano-LiFePO4 cathodes.Comment: 27 pages, 8 figure

    3,4-Methylenedioxymethamphetamine Alters Left Ventricular Function and Activates Nuclear Factor-Kappa B (NF-κB) in a Time and Dose Dependent Manner

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    3,4-Methylenedioxymethamphetamine (MDMA) is an illicit psychoactive drug with cardiovascular effects that have not been fully described. In the current study, we observed the effects of acute MDMA on rabbit left ventricular function. We also observed the effects of MDMA on nuclear factor-kappa B (NF-κB) activity in cultured rat ventricular myocytes (H9c2). In the rabbit, MDMA (2 mg/kg) alone caused a significant increase in heart rate and a significant decrease in the duration of the cardiac cycle. Inhibition of nitric oxide synthase (NOS) by pretreatment with L-NAME (10 mg/kg) alone caused significant dysfunction in heart rate, systolic pressure, diastolic pressure, duration of relaxation, duration of cardiac cycle, and mean left ventricular pressure. Pretreatment with L-NAME followed by treatment with MDMA caused significant dysfunction in additional parameters that were not abnormal upon exposure to either compound in isolation: duration of contraction, inotropy, and pulse pressure. Exposure to 1.0 mM MDMA for 6 h or 2.0 μM MDMA for 12 h caused increased nuclear localization of NF-κB in cultured H9c2 cells. The current results suggest that MDMA is acutely detrimental to heart function and that an intact cardiovascular NOS system is important to help mitigate early sequelae in some functional parameters. The delayed timing of NF-κB activation suggests that this factor may be relevant to MDMA induced cardiomyopathy of later onset

    Prevalent vertebral fractures among children initiating glucocorticoid therapy for the treatment of rheumatic disorders

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    Objective. Vertebral fractures are an under-recognized problem in children with inflammatory disorders. We studied spine health among 134 children (87 girls) with rheumatic conditions (median age 10 years) within 30 days of initiating glucocorticoid therapy. Methods. Children were categorized as follows: juvenile dermatomyositis (n = 30), juvenile idiopathic arthritis (n = 28), systemic lupus erythematosus and related conditions (n = 26), systemic arthritis (n = 22), systemic vasculitis (n = 16), and other conditions (n = 12). Thoracolumbar spine radiograph and dual x-ray absorptiometry for lumbar spine (L-spine) areal bone mineral density (BMD) were performed within 30 days of glucocorticoid initiation. Genant semiquantitative grading was used for vertebral morphometry. Second metacarpal morphometry was carried out on a hand radiograph. Clinical factors including disease and physical activity, calcium and vitamin D intake, cumulative glucocorticoid dose, underlying diagnosis, L-spine BMD Z score, and back pain were analyzed for association with vertebral fracture. Results. Thirteen vertebral fractures were noted in 9 children (7%). Of these, 6 patients had a single vertebral fracture and 3 had 2-3 fractures. Fractures were clustered in the mid-thoracic region (69%). Three vertebral fractures (23%) were moderate (grade 2); the others were mild (grade 1). For the entire cohort, mean ± SD L-spine BMD Z score was significantly different from zero (-0.55 ± 1.2, P \u3c 0.001) despite a mean height Z score that was similar to the healthy average (0.02 ± 1.0, P = 0.825). Back pain was highly associated with increased odds for fracture (odds ratio 10.6 [95% confidence interval 2.1-53.8], P = 0.004). Conclusion. In pediatric rheumatic conditions, vertebral fractures can be present prior to prolonged glucocorticoid exposure. © 2010, American College of Rheumatology

    Baseline Factors Associated With Glycemic Control and Weight Loss When Exenatide Twice Daily Is Added to Optimized Insulin Glargine in Patients With Type 2 Diabetes

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    OBJECTIVETo determine variables associated with glycemic and body weight responses when adding exenatide to basal insulin–treated type 2 diabetes.RESEARCH DESIGN AND METHODSExploratory subgroup analyses based on baseline A1C, disease duration, and BMI of a 30-week study comparing exenatide twice daily to placebo, added to optimized insulin glargine (intent-to-treat analysis: 137 exenatide; 122 placebo).RESULTSExenatide participants had greater A1C reductions compared with optimized insulin glargine alone, irrespective of baseline A1C (P < 0.001). Exenatide participants with longer diabetes duration and those with lower BMI had greater A1C reductions (P < 0.01). Exenatide participants lost more weight, regardless of baseline A1C or BMI (P < 0.05). Exenatide participants with longer diabetes duration lost the most weight (P < 0.001).CONCLUSIONSExenatide added to optimized basal insulin was associated with improved glycemic control and weight loss, irrespective of baseline A1C, diabetes duration, and BMI. Changes were evident in modestly obese patients and in those with longer diabetes duration

    Incident vertebral fractures among children with rheumatic disorders 12 months after glucocorticoid initiation: A national observational study

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    Objective. To determine the frequency of incident vertebral fractures (IVF) 12 months after glucocorticoid (GC) initiation in children with rheumatic diseases and to identify children at higher risk. Methods. Children with rheumatic diseases initiating GC were enrolled in a prospective observational study. Annual spine radiographs were evaluated using the Genant semiquantitative method. Spine areal bone mineral density (aBMD) was measured every 6 months. Clinical features, including cumulative GC dose, back pain, disease and physical activity, calcium and vitamin D intake, and spine aBMD Z scores, were analyzed for association with IVF. Results. Seven (6%) of 118 children (95% confidence interval 2.9-11.7%) had IVF. Their diagnoses were: juvenile dermatomyositis (n = 2), systemic lupus erythematosus (n = 3), systemic vasculitis (n = 1), and mixed connective tissue disease (n = 1). One child was omitted from the analyses after 4 months because of osteoporosis treatment for symptomatic IVF. Children with IVF received on average 50% more GC than those without (P = 0.030), had a greater increase in body mass index (BMI) at 6 months (P = 0.010), and had greater decrements in spine aBMD Z scores in the first 6 months (P = 0.048). Four (67%) of 6 children with IVF and data to 12 months had spine aBMD Z scores less than-2.0 at 12 months compared to 16% of children without IVF (P = 0.011). Conclusion. The incidence of VF 12 months following GC initiation was 6%; most children were asymptomatic. Children with IVF received more GC, had greater increases in BMI, and had greater declines in spine aBMD Z scores in the first 6 months. © 2012, American College of Rheumatology
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