Publications by authors named "Michael Gurney"

Dysregulation of intra- and extracellular pH in cancer contributes to extracellular matrix remodeling, favors cell migration, proliferation, and metastasis. Although the primary attention has been focused on the role of the ubiquitous Na/H exchanger isoform NHE1, the role of NHE3, the predominant apical isoform in colonic surface epithelium in the pathogenesis of colon cancer has not been investigated. Here, we show that NHE3 mRNA expression is significantly reduced in colorectal cancer patients and that low NHE3 expression is associated with poorer survival.

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Background & Aims: Intestinal epithelial cells (IECs) provide a barrier that separates the mucosal immune system from the luminal microbiota. IECs constitutively express low levels of major histocompatibility complex (MHC) class II proteins, which are upregulated upon exposure to interferon gamma. We investigated the effects of deleting MHCII proteins specifically in mice with infectious, dextran sodium sulfate (DSS)-, and T-cell-induced colitis.

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The deleterious effects of statins on skeletal muscle are well known, but the mechanism associated with these effects remains unresolved. Statins are associated with mitochondrial damage, which may contribute to muscle myopathy. Here we demonstrate that simvastatin induces mitophagy in skeletal muscle cells and hypothesized that attenuating this process by silencing the mitophagy adapter p62/sequestosome-1 (SQSTM1) might mitigate myotoxicity.

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Dendritic cells (DCs) are pivotal in regulating tolerogenic as well as immunogenic responses against microorganisms by directing both the innate and adaptive immune response. In health, phenotypically different DC subsets found in the gut mucosa are maintained in their tolerogenic state but switch to a pro-inflammatory phenotype during infection or chronic autoinflammatory conditions such as inflammatory bowel disease (IBD). The mechanisms that promote the switch among the mucosal DCs from a tolerogenic to an immunogenic, pro-inflammatory phenotype are incompletely understood.

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Several members of the family of Na/H exchangers are expressed in the gut, with varying expression patterns and cellular localization. Not only do they participate in the regulation of basic epithelial cell functions, including control of transepithelial Na absorption, intracellular pH (pH ), cell volume, and nutrient absorption, but also in cellular proliferation, migration, and apoptosis. Additionally, they modulate the extracellular milieu in order to facilitate other nutrient absorption and to regulate the intestinal microbial microenvironment.

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The autophagy pathway is critical for the long-term homeostasis of cells and adult organisms and is often activated during periods of stress. Reduced pathway efficacy plays a central role in several progressive neurological disorders that are associated with the accumulation of cytotoxic peptides and protein aggregates. Previous studies have shown that genetic and transgenic alterations to the autophagy pathway impacts longevity and neural aggregate profiles of adult Drosophila.

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Statement Of Problem: The use of lasers is growing widely in dentistry. Despite its clinical implications, most information and clinical data related to the removal of ceramic restorations with the aid of a laser is either anecdotal or in the form of clinical reports.

Purpose: The purpose of this in vitro study was to establish a parameter on the removal of lithium disilicate crowns with a laser and conduct an in vitro trial of crown removal based on the wattage and time of application.

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Autophagy, a cellular housekeeping process, is essential to maintain tissue homeostasis, particularly in long-lived cells such as cardiomyocytes. Autophagic activity declines with age and may explain many features of age-related cardiac dysfunction. In this review we summarize the current state of knowledge regarding age-related changes in autophagy in the heart.

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Autophagy is a lysosomal-dependent catabolic pathway that recycles various cytoplasmic-borne components, such as organelles and proteins, through the lysosomes. This process creates energy and biomolecules that are used to maintain homeostasis and to serve as an energy source under conditions of acute stress. Autophagic flux is a measure of efficiency or throughput of the pathway.

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We assessed the role of Dectin-1 in the immune response to the pathogenic fungus Coccidioides, both in vitro and in vivo, using mice with a targeted mutation in Clec7a. Elicited peritoneal macrophages responded to formalin-killed spherules (FKS) and alkali-treated FKS by secreting proinflammatory cytokines in a Dectin-1- and β-glucan-dependent manner. The responses of bone marrow-derived dendritic cells (BMDC) to the same stimulants were more complex; interleukin 1β (IL-1β) and tumor necrosis factor alpha (TNF-α) secretion was independent of Dectin-1, while IL-6, IL-10, and granulocyte-macrophage colony-stimulating factor (GM-CSF) were largely but not entirely dependent on Dectin-1.

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Elucidating how serine/threonine phosphatases regulate kinase function and bacterial virulence is critical for our ability to combat these infections. Group B streptococci (GBS) are β-hemolytic Gram-positive bacteria that cause invasive infections in humans. To adapt to environmental changes, GBS encodes signaling mechanisms comprising two component systems and eukaryotic-like enzymes.

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Group B Streptococcus (GBS) is the leading cause of meningitis in newborn infants. Bacterial cell surface appendages, known as pili, have been recently described in streptococcal pathogens, including GBS. The pilus tip adhesin, PilA, contributes to GBS adherence to blood-brain barrier (BBB) endothelium; however, the host receptor and the contribution of PilA in central nervous system (CNS) disease pathogenesis are unknown.

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Group B Streptococcus (GBS) is an important cause of invasive infections in humans. The pathogen encodes a number of virulence factors including the pluripotent beta-haemolysin/cytolysin (beta-H/C). As GBS has the disposition of both a commensal organism and an invasive pathogen, it is important for the organism to appropriately regulate beta-H/C and other virulence factors in response to the environment.

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Background: Group B Streptococcus (GBS) is the leading cause of bacterial meningitis in newborn infants. Because GBS is able to invade, survive, and cross the blood-brain barrier, we sought to identify surface-expressed virulence factors that contribute to blood-brain barrier penetration and the pathogenesis of meningitis.

Methods: Targeted deletion and insertional mutants were generated in different GBS clinical isolates.

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Background: The Connecticut Chiropractic Association authorized an ad hoc committee to study Connecticut chiropractic scope of practice in January 1999. This committee was chaired by Richard Duenas, DC, and included 4 other Connecticut-licensed doctors of chiropractic who responded to an appeal to participate.

Objective: Committee members investigated the terms primary care, primary care provider (PCP) (clinician, physician), neuromusculoskeletal care, neuromusculoskeletal care provider (clinician, physician), musculoskeletal care, and musculoskeletal care provider (clinician, physician) to determine which, if any, apply to the practice of chiropractic.

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Background: Eradication of Helicobacter pylori infection has had an impact on the treatment and recurrence rates of peptic ulcer disease and malignancies such as mucosa-associated lymphoid tissue lymphoma. Treatment options are cumbersome, expensive, and associated with side effects.

Methods: Randomized, prospective, open-labeled equivalence trial with a parallel-group design to compare eradication rates of H pylori with a 1-day, 4-drug regimen with a 7-day, 3-drug regimen.

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