773 research outputs found
Case Study: Chronic Recurrent Multifocal Osteomyelitis in the Femoral Diaphysis of a Young Female
Chronic recurrent multifocal osteomyelitis (CRMO) is relatively uncommon. Even though the name suggests it is the result of infection, this is not likely the case. Instead it is more likely the result of genetic, autoimmune, or autoinflammatory causes. Although CRMO has a benign course and responds well to anti-inflammatory medications, it can have a very aggressive clinical and imaging presentation overlapping with infectious osteomyelitis and malignancy. Therefore, radiologists and clinicians need to be aware of its clinical and imaging presentation to avoid morbidity associated with more aggressive treatment. We present the case of a ten-year-old female with CRMO as a solitary expansile-mixed lytic and sclerotic lesion in the distal femoral diaphysis. The diaphyseal location and mixed lytic and sclerotic appearance are less common and have an aggressive imaging appearance. We also review the pathophysiology, imaging findings, and therapeutic approach to this uncommon but clinically important condition
Resistance to cardiomyocyte hypertrophy in ae3-/- mice, deficient in the AE3 Cl-/HCO3- exchanger
Background: Cardiac hypertrophy is central to the etiology of heart failure. Understanding the molecular pathways promoting cardiac hypertrophy may identify new targets for therapeutic intervention. Sodium-proton exchanger (NHE1) activity and expression levels in the heart are elevated in many models of hypertrophy through protein kinase C (PKC)/MAPK/ERK/p90RSK pathway stimulation. Sustained NHE1 activity, however, requires an acid-loading pathway. Evidence suggests that the Cl-/HCO3- exchanger, AE3, provides this acid load. Here we explored the role of AE3 in the hypertrophic growth cascade of cardiomyocytes.Methods: AE3-deficient (ae3-/-) mice were compared to wildtype (WT) littermates to examine the role of AE3 protein in the development of cardiomyocyte hypertrophy. Mouse hearts were assessed by echocardiography. As well, responses of cultured cardiomyocytes to hypertrophic stimuli were measured. pH regulation capacity of ae3-/- and WT cardiomyocytes was assessed in cultured cells loaded with the pH-sensitive dye, BCECF-AM.Results: ae3-/- mice were indistinguishable from wild type (WT) mice in terms of cardiovascular performance. Stimulation of ae3-/- cardiomyocytes with hypertrophic agonists did not increase cardiac growth or reactivate the fetal gene program. ae3-/- mice are thus protected from pro-hypertrophic stimulation. Steady state intracellular pH (pHi) in ae3-/- cardiomyocytes was not significantly different from WT, but the rate of recovery of pHi from imposed alkalosis was significantly slower in ae3-/- cardiomyocytes.Conclusions: These data reveal the importance of AE3-mediated Cl-/HCO3- exchange in cardiovascular pH regulation and the development of cardiomyocyte hypertrophy. Pharmacological antagonism of AE3 is an attractive approach in the treatment of cardiac hypertrophy.Centro de Investigaciones Cardiovasculare
Identifying Key Issues and Potential Solutions for Integrated Arrival, Departure, Surface Operations by Surveying Stakeholder Preferences
NASA's Aeronautics Research Mission Directorate (ARMD) collaborates with the FAA and industry to provide concepts and technologies that enhance the transition to the next-generation air-traffic management system (NextGen). To facilitate this collaboration, ARMD has a series of Airspace Technology Demonstration (ATD) sub-projects that develop, demonstrate, and transitions NASA technologies and concepts for implementation in the National Airspace System (NAS). The second of these sub-projects, ATD-2, is focused on the potential benefits to NAS stakeholders of integrated arrival, departure, surface (IADS) operations. To determine the project objectives and assess the benefits of a potential solution, NASA surveyed NAS stakeholders to understand the existing issues in arrival, departure, and surface operations, and the perceived benefits of better integrating these operations. NASA surveyed a broad cross-section of stakeholders representing the airlines, airports, air-navigation service providers, and industry providers of NAS tools. The survey indicated that improving the predictability of flight times (schedules) could improve efficiency in arrival, departure, and surface operations. Stakeholders also mentioned the need for better strategic and tactical information on traffic constraints as well as better information sharing and a coupled collaborative planning process that allows stakeholders to coordinate IADS operations. To assess the impact of a potential solution, NASA sketched an initial departure scheduling concept and assessed its viability by surveying a select group of stakeholders for a second time. The objective of the departure scheduler was to enable flights to move continuously from gate to cruise with minimal interruption in a busy metroplex airspace environment using strategic and tactical scheduling enhanced by collaborative planning between airlines and service providers. The stakeholders agreed that this departure concept could improve schedule predictability and suggested several key attributes that were necessary to make the concept successful. The goals and objectives of the planned ATD-2 sub-project will incorporate the results of this stakeholder feedback
Overestimation of minimal model glucose effectiveness in presence of insulin response is due to undermodeling
Glucose effectiveness is an important determinant of glucose tolerance that can be derived from minimal model analysis of an intravenous glucose tolerance test (IVGTT). However, recent evidence suggests that glucose effectiveness is overestimated by minimal model analysis. Here we compare a new model-independent estimate of glucose effectiveness with the minimal model estimate by reanalyzing published data in which insulin-dependent diabetic subjects were each given IVGTTs under two conditions (Quon, M. J., C. Cochran, S. I. Taylor, and R. C. Eastman. Diabetes 43: 890-896, 1994). In one case, a basal insulin level was maintained (BI-IVGTT). In the second case, a dynamic insulin response was recreated (DI-IVGTT). Our results show that minimal model glucose effectiveness is very similar to the model- independent measurement during a BI-IVGTT but is three times higher during a DI-IVGTT. To investigate the causes of minimal model overestimation in the presence of a dynamic insulin response, Monte Carlo simulation studies on a two-compartment model of glucose kinetics with various insulin response patterns were performed. Results suggest that minimal model overestimation is due to single-compartment representation of glucose kinetics that results in a critical oversimplification in the presence of increasingly dynamic insulin secretion patterns
Epigallocatechin Gallate, a Green Tea Polyphenol, Mediates NO-dependent Vasodilation Using Signaling Pathways in Vascular Endothelium Requiring Reactive Oxygen Species and Fyn
Green tea consumption is associated with reduced cardiovascular mortality in some epidemiological studies. Epigallocatechin gallate (EGCG), a bioactive polyphenol in green tea, mimics metabolic actions of insulin to inhibit gluconeogenesis in hepatocytes. Because signaling pathways regulating metabolic and vasodilator actions of insulin are shared in common, we hypothesized that EGCG may also have vasodilator actions to stimulate production of nitric oxide (NO) from endothelial cells. Acute intra-arterial administration of EGCG to mesenteric vascular beds isolated ex vivo from WKY rats caused dose-dependent vasorelaxation. This was inhibitable by L-NAME (NO synthase inhibitor), wortmannin (phosphatidylinositol 3-kinase inhibitor), or PP2 (Src family kinase inhibitor). Treatment of bovine aortic endothelial cells (BAEC) with EGCG (50 microm) acutely stimulated production of NO (assessed with NO-specific fluorescent dye DAF-2) that was inhibitable by l-NAME, wortmannin, or PP2. Stimulation of BAEC with EGCG also resulted in dose- and time-dependent phosphorylation of eNOS that was inhibitable by wortmannin or PP2 (but not by MEK inhibitor PD98059). Specific knockdown of Fyn (but not Src) with small interfering RNA inhibited both EGCG-stimulated phosphorylation of Akt and eNOS as well as production of NO in BAEC. Treatment of BAEC with EGCG generated intracellular H(2)O(2) (assessed with H(2)O(2)-specific fluorescent dye CM-H(2)DCF-DA), whereas treatment with N-acetylcysteine inhibited EGCG-stimulated phosphorylation of Fyn, Akt, and eNOS. We conclude that EGCG has endothelial-dependent vasodilator actions mediated by intracellular signaling pathways requiring reactive oxygen species and Fyn that lead to activation of phosphatidylinositol 3-kinase, Akt, and eNOS. This mechanism may explain, in part, beneficial vascular and metabolic health effects of green tea consumption
New Directions: NASA's Airspace Operations and Safety Program
Overview briefing of Airspace Operations and Safety Program (AOSP) and Airspace Technology Demonstration (ATD) project
Airspace Technology Demonstration 2 (ATD-2) Project: Integrated Arrival/Departure/Surface Metroplex Traffic Management
Airspace Technology Demonstration 2, or ATD-2, is the integration of existing and emerging NASA, FAA, and industry technologies to significantly benefit arrival, departure, and surface operations. It provides solutions to several problems in the complicated, multi-airport metroplex environment
Musical components important for the Mozart K448 effect in epilepsy
There is growing evidence for the efficacy of music, specifically Mozart’s Sonata for Two Pianos in D Major (K448), at reducing ictal and interictal epileptiform activity. Nonetheless, little is known about the mechanism underlying this beneficial “Mozart K448 effect” for persons with epilepsy. Here, we measured the influence that K448 had on intracranial interictal epileptiform discharges (IEDs) in sixteen subjects undergoing intracranial monitoring for refractory focal epilepsy. We found reduced IEDs during the original version of K448 after at least 30-s of exposure. Nonsignificant IED rate reductions were witnessed in all brain regions apart from the bilateral frontal cortices, where we observed increased frontal theta power during transitions from prolonged musical segments. All other presented musical stimuli were associated with nonsignificant IED alterations. These results suggest that the “Mozart K448 effect” is dependent on the duration of exposure and may preferentially modulate activity in frontal emotional networks, providing insight into the mechanism underlying this response. Our findings encourage the continued evaluation of Mozart’s K448 as a noninvasive, non-pharmacological intervention for refractory epilepsy
Resistance to cardiomyocyte hypertrophy in ae3-/- mice, deficient in the AE3 Cl-/HCO3- exchanger
Background: Cardiac hypertrophy is central to the etiology of heart failure. Understanding the molecular pathways promoting cardiac hypertrophy may identify new targets for therapeutic intervention. Sodium-proton exchanger (NHE1) activity and expression levels in the heart are elevated in many models of hypertrophy through protein kinase C (PKC)/MAPK/ERK/p90RSK pathway stimulation. Sustained NHE1 activity, however, requires an acid-loading pathway. Evidence suggests that the Cl-/HCO3- exchanger, AE3, provides this acid load. Here we explored the role of AE3 in the hypertrophic growth cascade of cardiomyocytes.Methods: AE3-deficient (ae3-/-) mice were compared to wildtype (WT) littermates to examine the role of AE3 protein in the development of cardiomyocyte hypertrophy. Mouse hearts were assessed by echocardiography. As well, responses of cultured cardiomyocytes to hypertrophic stimuli were measured. pH regulation capacity of ae3-/- and WT cardiomyocytes was assessed in cultured cells loaded with the pH-sensitive dye, BCECF-AM.Results: ae3-/- mice were indistinguishable from wild type (WT) mice in terms of cardiovascular performance. Stimulation of ae3-/- cardiomyocytes with hypertrophic agonists did not increase cardiac growth or reactivate the fetal gene program. ae3-/- mice are thus protected from pro-hypertrophic stimulation. Steady state intracellular pH (pHi) in ae3-/- cardiomyocytes was not significantly different from WT, but the rate of recovery of pHi from imposed alkalosis was significantly slower in ae3-/- cardiomyocytes.Conclusions: These data reveal the importance of AE3-mediated Cl-/HCO3- exchange in cardiovascular pH regulation and the development of cardiomyocyte hypertrophy. Pharmacological antagonism of AE3 is an attractive approach in the treatment of cardiac hypertrophy.Centro de Investigaciones Cardiovasculare
Metallopanstimulin as a marker for head and neck cancer
BACKGROUND: Metallopanstimulin (MPS-1) is a ribosomal protein that is found in elevated amounts in the sera of patients with head and neck squamous cell carcinoma (HNSCC). We used a test, denoted MPS-H, which detects MPS-1 and MPS-1-like proteins, to determine the relationship between MPS-H serum levels and clinical status of patients with, or at risk for, HNSCC. PATIENTS AND METHODS: A total of 125 patients were prospectively enrolled from a university head and neck oncology clinic. Participants included only newly diagnosed HNSCC patients. Two control groups, including 25 non-smokers and 64 smokers, were studied for comparison. A total of 821 serum samples collected over a twenty-four month period were analyzed by the MPS-H radioimmunoassay. RESULTS: HNSCC, non-smokers, and smokers had average MPS-H values of 41.5 ng/mL, 10.2 ng/mL, and 12.8 ng/mL, respectively (p = 0.0001). CONCLUSION: We conclude that MPS-1 and MPS-1-like proteins are elevated in patients with HNSCC, and that MPS-H appears to be a promising marker of presence of disease and response to treatment in HNSCC patients
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