University of Tennessee Health Science Center

About: University of Tennessee Health Science Center is a education organization based out in Memphis, Tennessee, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 15716 authors who have published 26884 publications receiving 1176697 citations.

Prolonged methylprednisolone treatment suppresses systemic inflammation in patients with unresolving acute respiratory distress syndrome: evidence for inadequate endogenous glucocorticoid secretion and inflammation-induced immune cell resistance to glucocorticoids.

Abstract: Nuclear factor-kappaB (NF-kappaB) and glucocorticoid receptor-alpha (GR-alpha) have diametrically opposed functions in regulating inflammation. We investigated whether unresolving acute respiratory distress syndrome (ARDS) is associated with systemic inflammation- induced glucocorticoid resistance and whether prolonged methylprednisolone administration accelerates the suppression of systemic inflammatory indices and normalizes the sensitivity of the immune system to glucocorticoids. Patients enrolled into a randomized trial evaluating prolonged methylprednisolone administration in unresolving ARDS had serial plasma samples collected before and after randomization. In the plasma, we measured the concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukins (IL) IL-1beta and IL-6, adrenocorticotropic hormone (ACTH), and cortisol. The ability of patient plasma to influence the NF-kappaB and GR-signal transduction systems of normal peripheral blood leukocytes (PBL) was examined. Patients treated with methylprednisolone had progressive and sustained reductions of TNF-alpha, IL-1beta, IL-6, ACTH, and cortisol concentrations over time. Normal PBL exposed to plasma samples collected during methylprednisolone exhibited significant progressive increases in all aspects of GR-mediated activity and significant reductions in NF-kappaB DNA-binding and transcription of TNF-alpha and IL-1beta. These findings provide support for the presence of endogenous glucocorticoid inadequacy in the control of inflammation and systemic inflammation-induced peripheral glucocorticoid resistance in ARDS. Prolonged methylprednisolone administration accelerated the resolution of both systemic inflammation and peripheral acquired glucocorticoid resistance in ARDS.

A systematic and functional classification of Streptococcus pyogenes that serves as a new tool for molecular typing and vaccine development

Abstract: Streptococcus pyogenes ranks among the main causes of mortality from bacterial infections worldwide. Currently there is no vaccine to prevent diseases such as rheumatic heart disease and invasive streptococcal infection. The streptococcal M protein that is used as the substrate for epidemiological typing is both a virulence factor and a vaccine antigen. Over 220 variants of this protein have been described, making comparisons between proteins difficult, and hindering M protein-based vaccine development. A functional classification based on 48 emm-clusters containing closely related M proteins that share binding and structural properties is proposed. The need for a paradigm shift from type-specific immunity against S. pyogenes to emm-cluster based immunity for this bacterium should be further investigated. Implementation of this emm-cluster-based system as a standard typing scheme for S. pyogenes will facilitate the design of future studies of M protein function, streptococcal virulence, epidemiological surveillance, and vaccine development.

The Structure of Everyday Self-Care Decision Making in Chronic Illness

Abstract: As health care reform strategists increasingly recognize the critically important potential of effective everyday self-care decision making for reducing the burden of illness and the strain on health service systems, wemust find ways to understand and support it. In this study, the authors investigate persons with expertise in self-care management of type 2 diabetes,HIV/AIDS, and multiple sclerosis to understand how everyday self-care decision making is learned and experienced. They used interview, think-aloud, and focus groups to construct an account of how persons affected by these chronic diseases make decisions in relation to the choices in their everyday lives and learn to manage the untoward effects of these conditions accordingto their unique contexts and values. The findings form a conceptual foundation for ongoing inquiry into this complex phenomenon and provide insights that might assist clinicians to understand more fully the responses and attitudes of those they serve.

Detection of Anatomic Structures in Human Retinal Imagery

Abstract: The widespread availability of electronic imaging devices throughout the medical community is leading to a growing body of research on image processing and analysis to diagnose retinal disease such as diabetic retinopathy (DR). Productive computer-based screening of large, at-risk populations at low cost requires robust, automated image analysis. In this paper we present results for the automatic detection of the optic nerve and localization of the macula using digital red-free fundus photography. Our method relies on the accurate segmentation of the vasculature of the retina followed by the determination of spatial features describing the density, average thickness, and average orientation of the vasculature in relation to the position of the optic nerve. Localization of the macula follows using knowledge of the optic nerve location to detect the horizontal raphe of the retina using a geometric model of the vasculature. We report 90.4% detection performance for the optic nerve and 92.5% localization performance for the macula for red-free fundus images representing a population of 345 images corresponding to 269 patients with 18 different pathologies associated with DR and other common retinal diseases such as age-related macular degeneration.