Publications by authors named "Patricia C Meckert"

Article Synopsis
  • This study explores the relationship between Trypanosoma cruzi infection and T cell exhaustion, indicating that chronic infection is linked to impaired T cell responses due to the expression of inhibitory receptors like CTLA-4 and LIR-1.
  • Researchers found that most IFN-γ-producing CD4(+) T cells in infected patients expressed CTLA-4, particularly in those with severe heart disease, while fewer expressed LIR-1.
  • Additionally, CTLA-4 and LIR-1 engagement can diminish IFN-γ production, highlighting how persistent T. cruzi infection may disrupt effective immune responses by increasing these inhibitory receptors.
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Aims: Vulnerable plaques in coronary arteries are frequently found in individuals who died suddenly or due to an acute coronary syndrome. The prevalence and characteristics of these plaques in the middle-aged apparently healthy population are unknown.

Methods And Results: From a total of 652 hearts from transplant donors collected between 1996 and 2007, we selected those from apparently healthy individuals older than 40 years old who died of head trauma or stroke and had no evidence of prior vascular diseases.

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Arterial sialic acid (SA) has been shown to attenuate the binding of fibrinogen and low-density lipoproteins (LDL) to the vessel wall, presumably protecting against atherosclerosis. This study was aimed to assess the effect of changes in SA content in intimal thickening, an early step in the development of atherosclerosis. New Zealand white rabbits were subjected to bilateral carotid periarterial collaring, followed by in situ-perfusion with neuroaminidase (random artery) and with vehicle (contralateral control artery).

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Objective: Although the genetic program for reinitiating DNA synthesis exists in post-mitotic cardiomyocytes, and it was reported that in human acute myocardial infarction (AMI) a significant proportion of myocytes enter mitosis, the rule is that the lost tissue is replaced by a collagen scar. The purpose of this study was to search for the basis of this discordance in order to devise future strategies to induce division of myocytes into daughter cells that may replace the lost tissue with contractile cells.

Methods: In 15 human hearts with 1- to 21-day-old infarcts, the expression of the cell cycle proteins Ki67 antigen, cyclins D, A, and B1, the presence of mitotic bodies, and the ploidy status were investigated with immunoenzymatic methods, light and laser confocal microscopy, and densitometry in the myocytes surrounding the infarct area.

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Exogenous vascular endothelial growth factor (VEGF) improves tissue perfusion in large animals and humans with chronic myocardial ischemia. Because tissue perfusion is mainly dependent on the arteriolar tree, we hypothesized that the neovascularizing effect of VEGF should include arteriogenesis, an effect not as yet described in large mammalian models of myocardial ischemia. In the present study we investigated the effect of intramyocardial plasmid-mediated human VEGF(165) gene transfer (pVEGF(165)) on the proliferation of vessels with smooth muscle in a pig model of myocardial ischemia.

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