: Previous studies have demonstrated increased glucose uptake by F-fluorodeoxyglucose positron emission tomography (FDG-PET) in lung parenchyma in animal models or small pulmonary arterial hypertension (PAH) cohorts. However, it is not well known whether increased FDG uptake in the lung is a unique phenomenon in PAH or whether elevated pulmonary artery pressure (PAP) induces FDG uptake. : Nineteen patients with PAH, 8 patients with pulmonary hypertension due to left heart disease (PH-LHD), and 14 age matched control subjects were included.
View Article and Find Full Text PDFBackground: Natural killer (NK) cell impairment is a feature of pulmonary arterial hypertension (PAH) and contributes to vascular remodeling in animal models of disease. Although mutations in , the gene encoding the BMP (bone morphogenetic protein) type-II receptor, are strongly associated with PAH, the contribution of loss to NK cell impairment remains unknown. We explored the impairment of IL (interleukin)-15 signaling, a central mediator of NK cell homeostasis, as both a downstream target of loss and a contributor to the pathogenesis of PAH.
View Article and Find Full Text PDFPurpose: Written examinations such as multiple-choice question (MCQ) exams are a key assessment strategy in health professions education (HPE), frequently used to provide feedback, to determine competency, or for licensure decisions. However, traditional psychometric approaches for monitoring the quality of written exams, defined as items that are discriminant and contribute to increase the overall reliability and validity of the exam scores, usually warrant larger samples than are typically available in HPE contexts. The authors conducted a descriptive exploratory study to document how undergraduate medical education (UME) programs ensure the quality of their written exams, particularly MCQs.
View Article and Find Full Text PDFBackground: The induction of matrix metalloproteinases (MMPs) and reduction in tissue inhibitors of MMPs (TIMPs) plays a role in ischemia/reperfusion (I/R) injury post-myocardial infarction (MI) and subsequent left ventricular remodeling. We developed a hybrid dual isotope single-photon emission computed tomography/computed tomography approach for noninvasive evaluation of regional myocardial MMP activation with Tc-RP805 and dynamic Tl for determination of myocardial blood flow, to quantify the effects of intracoronary delivery of recombinant TIMP-3 (rTIMP-3) on I/R injury.
Methods: Studies were performed in control pigs (n=5) and pigs following 90-minute balloon occlusion-induced ischemia/reperfusion (I/R) of left anterior descending artery (n=9).
Background: Heart failure with reduced ejection fraction and obstructive sleep apnea (OSA), 2 states of increased metabolic demand and sympathetic nervous system activation, often coexist. Continuous positive airway pressure (CPAP), which alleviates OSA, can improve ventricular function. It is unknown whether this is due to altered oxidative metabolism or presynaptic sympathetic nerve function.
View Article and Find Full Text PDFThe association kinetics of CO binding to site-directed mutants of human deoxyhemoglobin were measured by stopped-flow rapid mixing techniques at pH 7.0, 20 degrees C. Hemoglobin tetramers were constructed from one set of native subunits and one set of mutated partners containing His(E7) to Gly, Val(E11) to Ala, or Val(E11) to Ile substitutions.
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