oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 1 )

2018 ( 2 )

2016 ( 1 )

2015 ( 33 )

Custom range...

Search Results: 1 - 10 of 707 matches for " Karel Geboes "
All listed articles are free for downloading (OA Articles)
Page 1 /707
Display every page Item
Evidence for the involvement of infectious agents in the pathogenesis of Crohns disease
Gert De Hertogh, Jeroen Aerssens, Karen P Geboes, Karel Geboes
World Journal of Gastroenterology , 2008,
Abstract: Many advances have been made in the understanding of Crohn’s disease (CD) pathogenesis during the last decade. CD is currently seen as a predominantly T-lymphocyte-driven disease characterized by the presence of a complex cocktail of interacting cytokines, chemokines and other mediators produced by a variety of cell types. Prevailing theories of CD pathogenesis suggest that patients’ T-lymphocytes are inappropriately activated in the setting of an immune imbalance, which is itself caused by an unfortunate confluence of genetic and environmental factors. The T-cell response then leads to the chronic inflammation characteristic for the disease. Various environmental factors may play a role in the development of CD, but microbes are most consistently implied. This theory is based on epidemiological, clinicopathological, genetic and experimental evidence. Despite the abundance of arguments for the implication of bacteria in the etiopathogenesis of CD, the precise role of bacteria in this disease still remains elusive. Three not necessarily mutually exclusive theories have been proposed: (1) an unidentified persistent pathogen; (2) an abnormally permeable mucosal barrier leading to excessive bacterial translocation; and (3) a breakdown in the balance between putative “protective” versus “harmful” intestinal bacteria (“dysbiosis”). At present, one cannot exclude with certainty any of these three proposed hypotheses; they may all apply to CD to a certain extent.
Histological healing in inflammatory bowel disease: A still unfulfilled promise
Vincenzo Villanacci,Elisabetta Antonelli,Karel Geboes,Giovanni Casella
World Journal of Gastroenterology , 2013, DOI: 10.3748/wjg.v19.i7.968
Abstract: Treatment of inflammatory bowel disease (IBD) is traditionally based on several drugs, including salicylates, corticosteroids, and antibiotics; in addition, the therapeutic armamentarium has considerably evolved with the advent of newer, effective therapeutic measures (such as the biological agents) that are able to improve in a considerable manner both the clinical and endoscopic variables. Thus, mucosal healing, at least considered from an endoscopic point of view, is today regarded as the ultimate endpoint for treatment of these conditions. However, it is also increasingly clear that endoscopic healing is not necessarily paralleled by histological healing; There are few doubts that the latter should be considered as a true, objective healing and the ultimate goal to reach when treating patients with IBD. Unfortunately, and surprisingly, only a few, incomplete, and somewhat conflicting data exist on this topic, especially because there is still the need to standardize both histological assessment and the severity grading of these disorders; Issues that have not been yet been resolved for clinical practice and therapeutic trials. Hopefully, with the help of an increased awareness on the clinical researchers’ side, and the availability of dedicated pathologists on the other side, this matter will be effectively faced and resolved in the near future.
Osteopontin and Other Regulators of Angiogenesis and Fibrogenesis in the Vitreous from Patients with Proliferative Vitreoretinal Disorders
Ahmed M. Abu El-Asrar,Mohd Imtiaz Nawaz,Dustan Kangave,Mohammed Mairaj Siddiquei,Karel Geboes
Mediators of Inflammation , 2012, DOI: 10.1155/2012/493043
Abstract: The aim of this study was to determine the levels of the angiogenic and fibrogenic factors osteopontin (OPN), high-mobility group box-1 (HMGB1), and connective tissue growth factor (CTGF) and the antiangiogenic and antifibrogenic pigment epithelium-derived factor (PEDF) in the vitreous fluid from patients with proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR), and rhegmatogenous retinal detachment with no PVR (RD). Vitreous samples from 48 PDR, 17 PVR and 30 RD patients were studied by enzyme-linked immunosorbent assay. OPN, HMGB1, CTGF, and PEDF levels were significantly higher in PDR patients than in RD patients ( ; 0.002; <0.001; <0.001, resp.). CTGF and PEDF levels were significantly higher in PVR patients than in RD patients ( , resp.). Exploratory logistic regression analysis identified significant associations between PDR and high levels of HMGB1, CTGF and PEDF, between PDR with active neovascularization and high levels of CTGF and PEDF, and between PDR with traction retinal detachment and high levels of HMGB1. In patients with PDR, there were significant correlations between the levels of PEDF and the levels of OPN ( ), HMGB1 ( ), and CTGF ( ). In patients with PVR, there were significant correlations between the levels of OPN and the levels of HMGB1 ( ) and PEDF ( ). Our findings suggest that OPN, HMGB1, and CTGF contribute to the pathogenesis of proliferative vitreoretinal disorders and that increased levels of PEDF may be a response to counterbalance the activity of angiogenic and fibrogenic factors in PDR and PVR. 1. Introduction Ischemia-induced pathologic growth of new blood vessels and expansion of extracellular matrix (ECM) in association with the outgrowth of fibrovascular epiretinal membranes at the vitreoretinal interface is the pathological hallmark in proliferative diabetic retinopathy (PDR) and often leads to catastrophic loss of vision due to vitreous hemorrhage and/or traction retinal detachment. Proliferative vitreoretinopathy (PVR) is a process of fibrocellular proliferation on either sides of the retina that may complicate rhegmatogenous retinal detachment. The formation and gradual contraction of epiretinal membranes causes a marked distortion of the retinal architecture and results in complex retinal detachments that are difficult to repair. Angiogenesis, the growth of new vascular networks from preexisting ones, is under tight regulation by a dynamic balance between angiogenic stimulators and inhibitors [1]. The biological process of fibrosis, typically associated with an abnormal accumulation
Kuschakewiczia versus Solenanthus—Palynological Data and the Generic Position of Kuschakewiczia turkestanica Regel and Smirnov (Boraginaceae)  [PDF]
Karel Sutory
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.47A1004
Abstract:

The genus Kuschakewiczia, Regel and Smirnov [1], was described including only one species, K. turkestanica. Later it was joint with the genus Solenanthus, although there are characters (corolla having narrow long lobes, filaments inserted on the corolla margin, low gynobasis, small scar on nutlets after disconnecting without any strip of tissue, reduced number of nutlets in the ripe fruit, etc.) which distinguish the two genera sufficiently. Palynological data, although not significantly different, support its separate positions on the discrete generic level.

Atonal homolog 1 Is a Tumor Suppressor Gene
Wouter Bossuyt,Avedis Kazanjian,Natalie De Geest,Sofie Van Kelst,Gert De Hertogh,Karel Geboes,Greg P. Boivin,Judith Luciani,Francois Fuks,Marinee Chuah,Thierry VandenDriessche,Peter Marynen,Jan Cools,Noah F. Shroyer,Bassem A. Hassan
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.1000039
Abstract: Colon cancer accounts for more than 10% of all cancer deaths annually. Our genetic evidence from Drosophila and previous in vitro studies of mammalian Atonal homolog 1 (Atoh1, also called Math1 or Hath1) suggest an anti-oncogenic function for the Atonal group of proneural basic helix-loop-helix transcription factors. We asked whether mouse Atoh1 and human ATOH1 act as tumor suppressor genes in vivo. Genetic knockouts in mouse and molecular analyses in the mouse and in human cancer cell lines support a tumor suppressor function for ATOH1. ATOH1 antagonizes tumor formation and growth by regulating proliferation and apoptosis, likely via activation of the Jun N-terminal kinase signaling pathway. Furthermore, colorectal cancer and Merkel cell carcinoma patients show genetic and epigenetic ATOH1 loss-of-function mutations. Our data indicate that ATOH1 may be an early target for oncogenic mutations in tissues where it instructs cellular differentiation.
Mucosal Gene Expression of Antimicrobial Peptides in Inflammatory Bowel Disease Before and After First Infliximab Treatment
Ingrid Arijs,Gert De Hertogh,Katleen Lemaire,Roel Quintens,Leentje Van Lommel,Kristel Van Steen,Peter Leemans,Isabelle Cleynen,Gert Van Assche,Séverine Vermeire,Karel Geboes,Frans Schuit,Paul Rutgeerts
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0007984
Abstract: Antimicrobial peptides (AMPs) protect the host intestinal mucosa against microorganisms. Abnormal expression of defensins was shown in inflammatory bowel disease (IBD), but it is not clear whether this is a primary defect. We investigated the impact of anti-inflammatory therapy with infliximab on the mucosal gene expression of AMPs in IBD.
Atonal homolog 1 Is a Tumor Suppressor Gene
Wouter Bossuyt equal contributor,Avedis Kazanjian equal contributor,Natalie De Geest,Sofie Van Kelst,Gert De Hertogh,Karel Geboes,Greg P Boivin,Judith Luciani,Francois Fuks,Marinee Chuah,Thierry VandenDriessche,Peter Marynen,Jan Cools,Noah F Shroyer ,Bassem A Hassan
PLOS Biology , 2009, DOI: 10.1371/journal.pbio.1000039
Abstract: Colon cancer accounts for more than 10% of all cancer deaths annually. Our genetic evidence from Drosophila and previous in vitro studies of mammalian Atonal homolog 1 (Atoh1, also called Math1 or Hath1) suggest an anti-oncogenic function for the Atonal group of proneural basic helix-loop-helix transcription factors. We asked whether mouse Atoh1 and human ATOH1 act as tumor suppressor genes in vivo. Genetic knockouts in mouse and molecular analyses in the mouse and in human cancer cell lines support a tumor suppressor function for ATOH1. ATOH1 antagonizes tumor formation and growth by regulating proliferation and apoptosis, likely via activation of the Jun N-terminal kinase signaling pathway. Furthermore, colorectal cancer and Merkel cell carcinoma patients show genetic and epigenetic ATOH1 loss-of-function mutations. Our data indicate that ATOH1 may be an early target for oncogenic mutations in tissues where it instructs cellular differentiation.
Unique Gene Expression and MR T2 Relaxometry Patterns Define Chronic Murine Dextran Sodium Sulphate Colitis as a Model for Connective Tissue Changes in Human Crohn’s Disease
Christine Breynaert, Tom Dresselaers, Clémentine Perrier, Ingrid Arijs, Jonathan Cremer, Leentje Van Lommel, Kristel Van Steen, Marc Ferrante, Frans Schuit, Séverine Vermeire, Paul Rutgeerts, Uwe Himmelreich, Jan L. Ceuppens, Karel Geboes, Gert Van Assche
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068876
Abstract: Introduction Chronically relapsing inflammation, tissue remodeling and fibrosis are hallmarks of inflammatory bowel diseases. The aim of this study was to investigate changes in connective tissue in a chronic murine model resulting from repeated cycles of dextran sodium sulphate (DSS) ingestion, to mimic the relapsing nature of the human disease. Materials and Methods C57BL/6 mice were exposed to DSS in drinking water for 1 week, followed by a recovery phase of 2 weeks. This cycle of exposure was repeated for up to 3 times (9 weeks in total). Colonic inflammation, fibrosis, extracellular matrix proteins and colonic gene expression were studied. In vivo MRI T2 relaxometry was studied as a potential non-invasive imaging tool to evaluate bowel wall inflammation and fibrosis. Results Repeated cycles of DSS resulted in a relapsing and remitting disease course, which induced a chronic segmental, transmural colitis after 2 and 3 cycles of DSS with clear induction of fibrosis and remodeling of the muscular layer. Tenascin expression mirrored its expression in Crohn’s colitis. Microarray data identified a gene expression profile different in chronic colitis from that in acute colitis. Additional recovery was associated with upregulation of unique genes, in particular keratins, pointing to activation of molecular pathways for healing and repair. In vivo MRI T2 relaxometry of the colon showed a clear shift towards higher T2 values in the acute stage and a gradual regression of T2 values with increasing cycles of DSS. Conclusions Repeated cycles of DSS exposure induce fibrosis and connective tissue changes with typical features, as occurring in Crohn’s disease. Colonic gene expression analysis revealed unique expression profiles in chronic colitis compared to acute colitis and after additional recovery, pointing to potential new targets to intervene with the induction of fibrosis. In vivo T2 relaxometry is a promising non-invasive assessment of inflammation and fibrosis.
Proposed Extension to the Natta Projection Notation System for Enabling an Indication of Relative Stereochemistry and the Stereochemical State  [PDF]
Karel D. Klika
International Journal of Organic Chemistry (IJOC) , 2011, DOI: 10.4236/ijoc.2011.14031
Abstract: A system of structure depiction, as an extension of the wedge and hashed wedge bonds (Natta projection), and text notation is herein suggested that embodies more explicit information—or reduced over-statement as circumstances warrant—on the stereochemical nature of the system at hand, in particular, for those cases where only the relative stereochemistry of a compound is known.
Suggested New Terms for Describing Chiral States and the State-Dependent Behavior of Chiral Systems  [PDF]
Karel D. Klika
International Journal of Organic Chemistry (IJOC) , 2012, DOI: 10.4236/ijoc.2012.23031
Abstract: Deficiencies in the terminology used to describe chiral systems exist for behaviors under various processes and thus a more general, robust terminology is considered. For example, the descriptions for characterizing melting point, solubility, and recrystallization behaviors were adopted well before it was realized that perturbation of the enantiomeric com-position (ec) due to self-disproportionation could be effected by processes other than recrystallization such as sublimation, chromatography over achiral substrates, and even distillation. Thus, an endeavor has been made to address the question of universally describing behaviors under processes that effect, or are dependent on, the ec. The main terms that have been defined with respect to behavior are homomate (analogous to a conglomerate), heteromate, bimate (analogous to a racemic compound), and unimate (analogous to a solid solution) and they apply to melting point, solubility, recrystallization, sublimation, distillation, and chromatographic processes. Additionally, suggestions for improving the terminology for describing the states of chiral systems are also considered and the defined terms are: holemate (hol, ec = 100%), scalemate (scl, 50% < ec < 100%), and equimate (eqm, ec = 50%).
Page 1 /707
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.