Publications by authors named "Edward Chan"

Polymethylmethacrylate (PMMA) bone cement technology has progressed from industrial Plexiglass administration in the 1950s to the recent advent of nanoparticle additives. Additives have been trialed to address problems with modern bone cements such as the loosening of prosthesis, high post-operative infection rates, and inflammatory reduction in interface integrity. This review aims to assess current additives used in PMMA bone cements and offer an insight regarding future directions for this biomaterial.

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Introduction: Autoantibodies to the Th/To antigen have been described in systemic sclerosis (SSc) and several proteins of the macromolecular Th/To complex have been reported to react with anti-Th/To antibodies. However, anti-Th/To has not been clinically utilized due to unavailability of commercial tests. The objective of the present study is to evaluate the newly developed ELISA and chemiluminescent immunoassay (CLIA) to measure autoantibodies to Rpp25 (a component of the Th/To complex) using immunoprecipitation (IP) as the reference method.

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Introduction: Autoantibodies and clinical manifestations in polymyositis/dermatomyositis (PM/DM) are affected by both genetic and environmental factors. The high prevalence of DM and anti-Mi-2 in Central America is thought to be associated with the high UV index of the area. The prevalences of autoantibodies and the clinical manifestations of PM/DM were evaluated comparing two cohorts in Mexico.

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MicroRNAs (miRNAs) are small, noncoding RNAs involved in posttranscriptional regulation of protein-coding genes in various biological processes. In our preliminary miRNA microarray analysis, miR-375 was identified as the most underexpressed in human oral tumor versus controls. The purpose of the present study is to examine the function of miR-375 as a candidate tumor suppressor miRNA in oral cancer.

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Pulse oximetry has revolutionized the ability to monitor oxygenation in a continuous, accurate, and non-invasive fashion. Despite its ubiquitous use, it is our impression and supported by studies that many providers do not know the basic principles behind its mechanism of function. This knowledge is important because it provides the conceptual basis of appreciating its limitations and recognizing when pulse oximeter readings may be erroneous.

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The incidence of lung and other diseases due to nontuberculous mycobacteria (NTM) is increasing. NTM sources include potable water, especially in households where NTM populate pipes, taps, and showerheads. NTM share habitats with free-living amoebae (FLA) and can grow in FLA as parasites or as endosymbionts.

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Nontuberculous mycobacteria (NTM) are environmental microbes that cause a variety of human diseases, particularly chronic lung infections. Despite the fact that NTM are widespread in the environment, relatively few people develop NTM lung disease, suggesting intrinsic vulnerability in some individuals. This paper reviews the evidence that underlying disorders predispose to NTM lung disease, in particular primary conditions that result in bronchiectasis, chronic obstructive pulmonary disease, α-1-antitrypsin anomalies, pneumoconiosis, pulmonary alveolar proteinosis, and frank immunosuppressive states such as that associated with the use of anti-tumor necrosis factor-α biologics, posttransplantation immunosuppression, and HIV infection.

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Mycobacterium abscessus is a rapidly growing mycobacterium increasingly detected in the neutrophil-rich environment of inflamed tissues, including the cystic fibrosis airway. Studies of the immune reaction to M. abscessus have focused primarily on macrophages and epithelial cells, but little is known regarding the neutrophil response despite the predominantly neutrophillic inflammation typical of these infections.

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Emergency managers are often charged with prioritizing the relative importance of key issues and tasks associated with disaster response. However, little work has been done to identify specific ways that the decision-making process can be improved. This exercise was conducted with 220 employees of the US Department of Veterans Affairs, who were asked to assign priority rankings to a list of possible options of the most important issues to address after a hypothetical disaster scenario impacting a Veterans Affairs Medical Center.

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Unlabelled: Senescence induction contributes to cancer therapy responses and is crucial for p53-mediated tumor suppression. However, whether p53 inactivation actively suppresses senescence induction has been unclear. Here, we show that E2F1 overexpression, due to p53 or p21 inactivation, promotes expression of human oncoprotein CIP2A, which in turn, by inhibiting PP2A activity, increases stabilizing serine 364 phosphorylation of E2F1.

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A 6-year-old male presented with a testicular mass, hepatosplenomegaly, and a pleural effusion while undergoing maintenance chemotherapy for treatment of T-cell acute lymphoblastic leukemia (T-ALL). He was subsequently diagnosed with a lymphoproliferative disorder that resembled hepatosplenic lymphoma (HSL). While the extranodal presentation and the protracted yet aggressive clinical course are consistent with HSL, the findings of monosomy 8 and polymorphic cell populations are unique and have not been previously described in this type of lymphoma.

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Innate immune response is the first defense against pathogens via recognition by various conserved pattern recognition receptors, such as TLRs, to initiate a rapid and strong cytokine alarm. TLR signaling-mediated cytokine production must be properly regulated to prevent pathological conditions deriving from overproduction of cytokines. In this study, the role of specific microRNAs in TLR-signaling pathway was investigated to reveal the cross-interaction and -regulation in the MyD88 pathway.

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MicroRNA (miRNA) are approximately 22 nucleotide single-stranded RNA that regulate the stability of target messenger RNA by selective binding to specific sites at the 3'-untranslated regions (UTR). This triggers repression in translation and mRNA degradation. It has been estimated that approximately 60% of all mRNA are under the control of miRNA.

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GW/P bodies contain two TNRC6A protein isoforms (GW182 and TNGW1) that function as translational repressors of mRNA through Ago2-mediated RNA silencing. Autoantibodies to GW/P body components GW182, Ge-1 and Ago2 have previously been correlated with clinical autoimmune diseases including neurological disease, Sjögren's syndrome, systemic lupus erythematosus, rheumatoid arthritis and primary biliary cirrhosis. No studies were published to date examining if patients with autoantibodies directed against GW/P bodies contain autoantibodies to the trinucleotide repeat (TNR) region of TNGW1, which differs from GW182 only by the addition of an N-terminal QP-rich 253 amino acid sequence.

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GW182 is an 182 kDa protein with multiple glycine/tryptophan repeats (GW or WG) playing a central role in siRNA- and miRNA-mediated gene silencing. GW182 interacts with its functional partner Argonaute proteins (AGO) via multiple domains to exert its silencing activity in both pathways. In siRNA-mediated silencing, knockdown either GW182 or Ago2 causes loss of silencing activity correlating with the disassembly of GWBs.

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Like many other classical autoantibodies in systemic rheumatic diseases, anti-Su antibodies were originally defined by the double immunodiffusion assay in the early 80s. However, despite its high prevalence, only a few reports on anti-Su were published in the following years and the progress in characterizing the target antigens and clinical significance was slow, probably due to its inconsistent or poor reactivity in other standard immunoassays. In 2006 the target antigen was identified as the microRNA (miRNA)-binding protein Argonaute 2 (Ago2).

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Human autoantibodies were a key to the discovery of GW bodies and their integral protein, GW182. This publication marks the tenth anniversary of the discovery of GW182. As it turns out, the discovery of GW182 was quite timely because it coincided with the elucidation of the RNA interference (RNAi) pathway, which is now known to have a major role in post-transcriptional gene regulation.

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Good's syndrome is an acquired immunodeficiency state associated with thymoma and characterized by recurrent pulmonary infections. We describe a 67-year-old woman who presented with respiratory symptoms caused by concomitant disseminated cytomegalovirus infection and Pneumocystis jiroveci pneumonia 38 months after thymectomy for a thymoma. Immunologic analysis revealed hypogammaglobulinemia with absent B-cell population as demonstrated by flow cytometry, consistent with Good's syndrome.

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Rationale: Among patients with nontuberculous mycobacterial lung disease is a subset of previously healthy women with a slender body morphotype, often with scoliosis and/or pectus excavatum. We hypothesize that unidentified factors predispose these individuals to pulmonary nontuberculous mycobacterial disease.

Objectives: To compare body morphotype, serum adipokine levels, and whole-blood cytokine responses of patients with pulmonary nontuberculous mycobacteria (pNTM) with contemporary control subjects who are well matched demographically.

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Purpose: Autoantibodies to cytoplasmic structures called rods and rings (RR) are primarily specific to patients with hepatitis C virus (HCV) infection treated with pegylated interferon-alpha/ribavirin (IFN/R). Our aim is to examine anti-RR antibodies specificity and correlation with the response to IFN/R therapy in two independent cohorts (US and Italy) of HCV patients.

Methods: Sera from the US cohort (n = 47) and the Italian cohort (n = 46) pre-selected for anti-RR antibodies were analyzed by immunofluorescence and radioimmunoprecipitation.

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GW182 binds to Argonaute (AGO) proteins and has a central role in miRNA-mediated gene silencing. Using lentiviral shRNA-induced GW182 knockdown in HEK293 cells, this study identifies a new role of GW182 in regulating miRNA stability. Stably knocking down GW182 or its paralogue TNRC6B reduces transfected miRNA-mimic half-lives.

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This randomized controlled trial examined the psychological, physical, and neurophysiological effects of a qigong exercise program on depressed elders with chronic medical illness. The experimental group (n = 21, 80 ± 7 years) was given a 12-week qigong exercise program, while the comparison group (n = 17, 81 ± 8 years) participated in a newspaper reading program with the same duration and frequency. Measurement of depression symptoms, psychosocial functioning, muscle strengths, salivary cortisol, and serum serotonin was conducted.

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