Annals of medicine
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Despite the fact that the heart requires huge amounts of energy to sustain contractile function, it has limited energy reserves and must therefore continually produce large amounts of adenosine triphosphate (ATP) to sustain function. Fatty acids are the primary energy substrate of the adult heart, with more than 60% of the energy normally obtained from the oxidation of fatty acids, the remainder coming from the metabolism of carbohydrates. Alterations in both the rates of ATP production and the type of energy substrate used by the heart can have consequences on contractile function, as well as on its ability to respond to energetic stresses. ⋯ Heart failure is characterized by an inefficient pumping of the heart, which fails to meet the energy requirements of the body. A number of cardiomyopathies can lead to heart failure. This paper will review the alterations in energy metabolism that occur in a number cardiomyopathies, including ischemic and diabetic cardiomyopathies, as well as hypertrophic cardiomyopathies resulting from mutations in enzymes involved in energy metabolism, such as 5' adenosine monophosphate-activated protein kinase (AMPK).
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We hypothesized that indices of angiogenesis (vascular endothelial growth factor (VEGF), angiopoietins (Ang-1 and -2), platelet activation (soluble P-selectin)) and endothelial damage/dysfunction (von Willebrand factor (vWf)) would be more deranged in South Asians than in white Europeans when measured within the coronary sinus or coronary artery per se (that is, intracardiac sampling of blood supplying and draining the heart), as compared to measurements from the peripheral venous system. ⋯ Indices of angiogenesis, platelet activation, and endothelial damage/dysfunction are comparable in South Asians and their white European counterparts. Our results suggest that their pathophysiological roles may be comparable in South Asians and white Europeans in the context of coronary artery disease.
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Diabetes increases the risk for depression. ⋯ Diabetes has only a minor independent effect on concurrent occurrence of depressive symptoms, while cardiovascular disease seems to be a more important underlying factor. The association between disease and depression is in particular characteristic to individuals born with a low birth weight.
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The prevalence of immunoglobulin E (IgE)-mediated allergic diseases has been increasing for the last four decades. In this review determinants for an increased IgE synthesis are discussed on both an epidemiological and on an immunological level with special emphasis on the differentiation of the B cell to an IgE-producing plasma cell. Factors that favor an IgE immune response are low antigen doses and immunization via mucous membranes, but it is highly likely that other environmental factors besides exposure to the allergenic sources play a role. ⋯ In order for a B lymphocyte to switch to IgE production it needs two signals provided by a Th2 cell in the form of the cytokines interleukin (IL-) 4/IL-13 and ligation of the CD40. In spite of a half-life of only a few days, there is evidence that the IgE response may last for years even without allergen stimulation. This is likely to be caused by long-lived IgE-producing plasma cells, and such cells may be difficult to target therapeutically thus emphasizing the need for more knowledge on preventable causes of IgE- and allergy development.
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Multiple lines of evidence suggest that the circadian clock contributes to the pathogenesis of winter depression or seasonal affective disorder (SAD). We hypothesized that sequence variations in three genes, including Per2, Arntl, and Npas2, which form a functional unit at the core of the circadian clock, predispose to winter depression. ⋯ Variations in the three circadian clock genes Per2, Arntl, and Npas2 are associated with the disease, supporting the hypothesis that the circadian clock mechanisms contribute to winter depression.