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1.
Ann Phys Rehabil Med ; 65(5): 101621, 2022 Sep.
Article in English | MEDLINE | ID: mdl-34896606

ABSTRACT

BACKGROUND: The carriage of carbapenemase-producing Enterobacteriaceae (CPE) might lengthen the time to functional recovery (TTFR) for inpatients in post-acute care (PAC) units. OBJECTIVE: We aimed to assess the impact of CPE carriage on TTFR in a PAC facility. METHODS: This 2-year retrospective cohort study included 20 CPE-positive patients and 54 CPE-negative patients admitted to 3 PAC units (general, orthopaedic and neurological rehabilitation units) in a teaching hospital from January 2017 to December 2019. Potential risk factors and demographic data were collected from patients' medical records, the French national hospital discharge database, and the hospital's CPE surveillance database. Functional recovery was defined as the median difference in functional independence measure (FIM) between admission and discharge from each unit. Survival analysis and multiple Cox regression models were used to predict the TTFR and identify factors associated with functional recovery. RESULTS: The overall median [interquartile range] TTFR was 50 days [36-66]. Longer median TTFR was associated with CPE carriage (63 vs 47 days in the CPE-negative group; adjusted hazard ratio (aHR) 0.35, 95% CI 0.13-0.97) and presence of a peripheral venous catheter (aHR 3.51, 1.45-8.46); shorter TTFR was associated with admission to an orthopaedic versus general rehabilitation unit (aHR 3.11, 1.24-7.82). CONCLUSIONS: CPE carriage in inpatient PAC facilities was associated with long TTFR. Further studies are needed to explore the mechanisms involved in these adverse events and to identify possible preventive measures.


Subject(s)
Carbapenem-Resistant Enterobacteriaceae , Enterobacteriaceae Infections , Bacterial Proteins , Enterobacteriaceae , Humans , Inpatients , Retrospective Studies , Subacute Care , beta-Lactamases
2.
Biofouling ; 37(1): 49-60, 2021 01.
Article in English | MEDLINE | ID: mdl-33522301

ABSTRACT

Dodecyltrimethylammonium chloride (DTAC) was trapped into maltodextrins/pectin spray dried microcapsules to improve its activity against Salmonella enteritidis and Staphylococcus aureus biofilms. Two different microcapsules were prepared: uncomplexed DTAC-microcapsules (UDM), containing DTAC and maltodextrins; and complexed DTAC-microcapsules (CDM) containing DTAC complexed with pectin and maltodextrins. The minimum inhibitory concentrations (MIC) of both free and microencapsulated DTAC were investigated against S. Enteritidis and S. aureus. The MICs of DTAC were significantly lower when encapsulated. CDM treatment resulted in a 2 and 3.2 log reduction in S. aureus and S. Enteritidis biofilm culturable biomass, respectively. Microencapsulation reduced the cytotoxicity of DTAC by up to 32-fold. Free DTAC and CDM targeted the cell membrane resulting in the leakage of the intracellular molecules and subsequent cell death. The development of DTAC microcapsules reduced the amount of DTAC required to maintain the high standards of cleanliness and hygiene required in the food processing industries.


Subject(s)
Salmonella enteritidis , Staphylococcus aureus , Biofilms , Capsules , Quaternary Ammonium Compounds
3.
Mol Cancer Ther ; 19(1): 168-177, 2020 01.
Article in English | MEDLINE | ID: mdl-31594825

ABSTRACT

The insulin-like growth factor type 1 receptor (IGF-1R) is important in tumorigenesis, and its overexpression occurs in numerous tumor tissues. To date, therapeutic approaches based on mAbs and tyrosine kinase inhibitors targeting IGF-1R have only shown clinical benefit in specific patient populations. We report a unique IGF-1R-targeted antibody-drug conjugate (ADC), W0101, designed to deliver a highly potent cytotoxic auristatin derivative selectively to IGF-1R overexpressing tumor cells. The mAb (hz208F2-4) used to prepare the ADC was selected for its specific binding properties to IGF-1R compared with the insulin receptor, and for its internalization properties. Conjugation of a novel auristatin derivative drug linker to hz208F2-4 did not alter its binding and internalization properties. W0101 induced receptor-dependent cell cytotoxicity in vitro when applied to various cell lines overexpressing IGF-1R, but it did not affect normal cells. Efficacy studies were conducted in several mouse models expressing different levels of IGF-1R to determine the sensitivity of the tumors to W0101. W0101 induced potent tumor regression in certain mouse models. Interestingly, the potency of W0101 correlated with the expression level of IGF-1R evaluated by IHC. In an MCF-7 breast cancer model with high-level IGF-1R expression, a single injection of W0101 3 mg/kg led to strong inhibition of tumor growth. W0101 provides a potential new therapeutic option for patients overexpressing IGF-1R. A first-in-human trial of W0101 is currently ongoing to address clinical safety.


Subject(s)
Immunoconjugates/therapeutic use , Neoplasms/drug therapy , Receptor, IGF Type 1/antagonists & inhibitors , Animals , Cell Line, Tumor , Female , Humans , Immunoconjugates/pharmacology , Mice , Mice, Nude , Neoplasms/pathology
4.
Bull Cancer ; 106(1S): S1-S9, 2019 Jan.
Article in French | MEDLINE | ID: mdl-30580913

ABSTRACT

Allogeneic hematopoietic cell transplantation (HCT) is part of the standard of care for many hematological diseases. Over the last decades, significant advances in patient and donor selection, conditioning regimens as well as supportive care of patients undergoing allogeneic HCT leading to improved overall survival have been made. In view of many new treatment options in cellular and molecular targeted therapies, the place of allogeneic transplantation in therapy concepts must be reviewed. Most aspects of HCT are well standardized by national guidelines or laws as well as by certification labels such as FACT-JACIE. However, the requirements for human resources, construction and layout of a unit treating patients during the transplantation procedure and for different complications are not well defined. Here, we describe the process of planning a transplant unit in order to open a discussion that could lead to more precise guidelines in the field of personnel and infrastructural requirements for hospitals caring for people with severe immunosuppression.


Subject(s)
Bone Marrow Transplantation/standards , Health Facility Environment/standards , Hematologic Diseases/therapy , Hematopoietic Stem Cell Transplantation/standards , Air/standards , Cell- and Tissue-Based Therapy/standards , Diet, Healthy/standards , Donor Selection/standards , France , Health Personnel/standards , Hospital Units/standards , Humans , Hygiene , Immunosuppression Therapy/standards , Monitoring, Physiologic/methods , Protective Clothing/standards , Societies, Medical , Sterilization/standards , Transplantation, Homologous/standards , Visitors to Patients
5.
J Infect Prev ; 18(2): 78-83, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28989509

ABSTRACT

BACKGROUND: Nasendoscopes are widely used in the outpatient ENT setting. Their reprocessing requires high-level disinfection (HLD). Recently, a wiping procedure using chlorine dioxide (ClO2) has been proposed as an alternative to HLD traditional procedures. OBJECTIVE: To assess the effectiveness of the HLD wiping procedure versus soaking procedure on a contaminated nasendoscope. METHOD: A nasendoscope was contaminated with four strains of bacteria and Bacillus subtilis spores. After HLD either with the wiping procedure or with the soaking procedure (PA), the reduction of the initial contamination was determined. FINDINGS: The wiping procedure with ClO2 displayed more than 5 log reduction for vegetative bacteria after 30 s contact time (CT) and 4 log reduction on B. subtilis spores after 2 min CT. The soaking procedure with PA displayed similar results on planktonic bacteria after 10 min CT but the log reduction of B. subtilis remained below 4. CONCLUSION: The ClO2 wiping procedure showed bactericidal and sporicidal efficacy on a contaminated nasendoscope in a shorter time compared to the PA soaking procedure. Thus, ClO2 wiping procedure might be considered as an alternative to the traditional HLD procedure for nasendoscopes.

6.
J Cell Sci ; 128(18): 3502-13, 2015 Sep 15.
Article in English | MEDLINE | ID: mdl-26224876

ABSTRACT

The nuclear factor κB (NF-κB) transcription factor is a master regulator of inflammation. Short-term NF-κB activation is generally beneficial. However, sustained NF-κB might be detrimental, directly causing apoptosis of cells or leading to a persistent damaging inflammatory response. NF-κB activity in stressed cells needs therefore to be controlled for homeostasis maintenance. In mildly stressed cells, caspase-3 cleaves p120 RasGAP, also known as RASA1, into an N-terminal fragment, which we call fragment N. We show here that this fragment is a potent NF-κB inhibitor. Fragment N decreases the transcriptional activity of NF-κB by promoting its export from the nucleus. Cells unable to generate fragment N displayed increased NF-κB activation upon stress. Knock-in mice expressing an uncleavable p120 RasGAP mutant showed exaggerated NF-κB activation when their epidermis was treated with anthralin, a drug used for the treatment of psoriasis. Our study provides biochemical and genetic evidence of the importance of the caspase-3-p120-RasGAP stress-sensing module in the control of stress-induced NF-κB activation.


Subject(s)
Caspase 3/metabolism , NF-kappa B/metabolism , Peptide Fragments , p120 GTPase Activating Protein/metabolism , Animals , HEK293 Cells , Humans , Mice , Mice, Knockout , NF-kappa B/chemistry , Rats , Stress, Physiological/physiology , p120 GTPase Activating Protein/chemistry
7.
PLoS One ; 8(7): e70331, 2013.
Article in English | MEDLINE | ID: mdl-23875026

ABSTRACT

Myocardial ischemic postconditioning (PosC) describes an acquired resistance to lethal ischemia-reperfusion (I/R) injury afforded by brief episodes of I/R applied immediately after the ischemic insult. Cardioprotection is conveyed by parallel signaling pathways converging to prevent mitochondria permeability transition. Recent observations indicated that PostC is associated with free radicals generation, including nitric oxide (NO(.)) and superoxide (O2 (.-)), and that cardioprotection is abrogated by antioxidants. Since NO. And O2 (. -) react to form peroxynitrite, we hypothesized that postC might trigger the formation of peroxyntrite to promote cardioprotection in vivo. Rats were exposed to 45 min of myocardial ischemia followed by 3h reperfusion. PostC (3 cycles of 30 seconds ischemia/30 seconds reperfusion) was applied at the end of index ischemia. In a subgroup of rats, the peroxynitrite decomposition catalyst 5,10,15,20-tetrakis(4-sulphonatophenyl) porphyrinato iron (FeTPPS) was given intravenously (10 mg/kg(-1)) 5 minutes before PostC. Myocardial nitrotyrosine was determined as an index of peroxynitrite formation. Infarct size (colorimetric technique and plasma creatine kinase-CK-levels) and left ventricle (LV) function (micro-tip pressure transducer), were determined. A significant generation of 3-nitrotyrosine was detected just after the PostC manoeuvre. PostC resulted in a marked reduction of infarct size, CK release and LV systolic dysfunction. Treatment with FeTPPS before PostC abrogated the beneficial effects of PostC on myocardial infarct size and LV function. Thus, peroxynitrite formed in the myocardium during PostC induces cardioprotective mechanisms improving both structural and functional integrity of the left ventricle exposed to ischemia and reperfusion in vivo.


Subject(s)
Cardiotonic Agents/pharmacology , Heart/drug effects , Ischemic Postconditioning , Myocardial Reperfusion Injury/prevention & control , Peroxynitrous Acid/pharmacology , Animals , Cytoprotection/drug effects , Heart/physiology , Male , Metalloporphyrins/pharmacology , Myocardial Infarction/metabolism , Myocardial Infarction/prevention & control , Myocardium/metabolism , Rats , Rats, Wistar , Tyrosine/analogs & derivatives , Tyrosine/metabolism
8.
Med Mycol ; 49(8): 825-33, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21526911

ABSTRACT

Immunosuppressed patients are at high risk of acquiring airborne fungal infections, mainly caused by Aspergillus species. Although HEPA filters are recommended to prevent environmental exposure, mobile air-treatment units can be an alternative. However, many different models of mobile units are available but there are few data on their fungal aero-decontamination efficacy and usefulness in the prevention of Aspergillus infections. Thus, we developed a challenge test, based on the aerosolization of 10(6) Aspergillus niger conidia, in order to compare the particle and fungal decontamination efficacy of the following four mobile air-treatment systems; Plasmair T2006, Mobil'Air 1200 (MA1200), Mobil'Air 600 (MA600) combined with Compact AirPur Mobile C250 (C250), and the prototype unit Compact AirPur Mobile 1800 (C1800). The use of all these air-treatment systems was able to significantly decrease the concentration of particles or fungal viable conidia. ISO7 was the maximum particle class reached within 20 min with the Plasmair T2006 and MA1200, 1 h by the combined MA600/C250, and 1 h and 30 min with the C1800. After 2 h, fungal counts were significantly lower with Plasmair T2006, MA1200 and the combined MA600/C250 (2.2 ± 1.9 to 5.0 ± 3.7 CFU/m(3)) than achieved with the C1800 (23.8 ± 12.8 CFU/m(3); P ≤ 6.0E-3). All the air-treatment systems were able to decrease aerial particle and fungal counts, but their efficacy was variable, depending on the units' air-treatment modalities and rates of air volume that was processed. This comparative study could be helpful in making an informed choice of mobile units, and in improving the prevention of air-transmitted fungal infections in non-protected areas.


Subject(s)
Air Conditioning/instrumentation , Air Pollution, Indoor/prevention & control , Aspergillosis/prevention & control , Aspergillus niger/isolation & purification , Decontamination/instrumentation , Infection Control/instrumentation , Air Microbiology , Air Pollutants , Aspergillosis/microbiology , Colony Count, Microbial , Fungi/isolation & purification , Humans , Spores, Fungal
9.
Cardiovasc Res ; 89(3): 586-94, 2011 Feb 15.
Article in English | MEDLINE | ID: mdl-21113057

ABSTRACT

AIMS: High-mobility group box 1 (HMGB1) is a nuclear protein actively secreted by immune cells and passively released by necrotic cells that initiates pro-inflammatory signalling through binding to the receptor for advance glycation end-products. HMGB1 has been established as a key inflammatory mediator during myocardial infarction, but the proximal mechanisms responsible for myocardial HMGB1 expression and release in this setting remain unclear. Here, we investigated the possible involvement of peroxynitrite, a potent cytotoxic oxidant formed during myocardial infarction, on these processes. METHODS AND RESULTS: The ability of peroxynitrite to induce necrosis and HMGB1 release in vitro was evaluated in H9c2 cardiomyoblasts and in primary murine cardiac cells (myocytes and non-myocytes). In vivo, myocardial HMGB1 expression and nitrotyrosine content (a marker of peroxynitrite generation) were determined following myocardial ischaemia and reperfusion in rats, whereas peroxynitrite formation was inhibited by two different peroxynitrite decomposition catalysts: 5,10,15,20-tetrakis(4-sulphonatophenyl) porphyrinato iron (III) (FeTPPS) or Mn(III)-tetrakis(4-benzoic acid) porphyrin chloride (MnTBAP). In all types of cells studied, peroxynitrite (100 µM) elicited significant necrosis, the loss of intracellular HMGB1, and its passive release into the medium. In vivo, myocardial ischaemia-reperfusion induced significant myocardial necrosis, cardiac nitrotyrosine formation, and marked overexpression of myocardial HMGB1. FeTPPS reduced nitrotyrosine, decreased infarct size, and suppressed HMGB1 overexpression, an effect that was similarly obtained with MnTBAP. CONCLUSION: These findings indicate that peroxynitrite represents a key mediator of HMGB1 overexpression and release by cardiac cells and provide a novel mechanism linking myocardial oxidative/nitrosative stress with post-infarction myocardial inflammation.


Subject(s)
HMGB1 Protein/metabolism , Myoblasts, Cardiac/metabolism , Myocardial Infarction/metabolism , Peroxynitrous Acid/pharmacology , Animals , Apoptosis/drug effects , Apoptosis/physiology , Cells, Cultured , Male , Mice , Mice, Inbred C57BL , Mitogen-Activated Protein Kinases/metabolism , Myoblasts, Cardiac/drug effects , Myoblasts, Cardiac/pathology , Myocardial Infarction/pathology , Necrosis , Peroxynitrous Acid/metabolism , Rats , Rats, Wistar , Receptor for Advanced Glycation End Products , Receptors, Immunologic/metabolism , Toll-Like Receptor 4/metabolism , Tyrosine/analogs & derivatives , Tyrosine/metabolism , Up-Regulation/drug effects , Up-Regulation/physiology
10.
PLoS One ; 5(9): e12687, 2010 Sep 13.
Article in English | MEDLINE | ID: mdl-20856884

ABSTRACT

BACKGROUND: Myocardial contractile failure in septic shock may develop following direct interactions, within the heart itself, between molecular motifs released by pathogens and their specific receptors, notably those belonging to the toll-like receptor (TLR) family. Here, we determined the ability of bacterial flagellin, the ligand of mammalian TLR5, to trigger myocardial inflammation and contractile dysfunction. METHODOLOGY/PRINCIPAL FINDINGS: TLR5 expression was determined in H9c2 cardiac myoblasts, in primary rat cardiomyocytes, and in whole heart extracts from rodents and humans. The ability of flagellin to activate pro-inflammatory signaling pathways (NF-kappaB and MAP kinases) and the expression of inflammatory cytokines was investigated in H9c2 cells, and, in part, in primary cardiomyocytes, as well as in the mouse myocardium in vivo. The influence of flagellin on left ventricular function was evaluated in mice by a conductance pressure-volume catheter. Cardiomyocytes and intact myocardium disclosed significant TLR5 expression. In vitro, flagellin activated NF-kappaB, MAP kinases, and the transcription of inflammatory genes. In vivo, flagellin induced cardiac activation of NF-kappaB, expression of inflammatory cytokines (TNF alpha, IL-1 beta, IL-6, MIP-2 and MCP-1), and provoked a state of reversible myocardial dysfunction, characterized by cardiac dilation, reduced ejection fraction, and decreased end-systolic elastance. CONCLUSION/SIGNIFICANCE: These results are the first to indicate that flagellin has the ability to trigger cardiac innate immune responses and to acutely depress myocardial contractility.


Subject(s)
Flagellin/immunology , Heart/physiopathology , Myocardial Contraction , Myocardium/immunology , Shock, Septic/immunology , Shock, Septic/physiopathology , Animals , Cell Line , Cells, Cultured , Cytokines/genetics , Cytokines/immunology , Humans , Immunity, Innate , Male , Mice , Mice, Inbred BALB C , Mice, Knockout , Myoblasts, Cardiac/immunology , Myocytes, Cardiac/immunology , NF-kappa B/genetics , NF-kappa B/immunology , Rats , Salmonella/immunology , Salmonella Infections/immunology , Salmonella Infections/microbiology , Salmonella Infections/physiopathology , Shock, Septic/microbiology , Toll-Like Receptor 5/genetics , Toll-Like Receptor 5/immunology
11.
Crit Care ; 14(4): R160, 2010.
Article in English | MEDLINE | ID: mdl-20731882

ABSTRACT

INTRODUCTION: Systemic inflammation in sepsis is initiated by interactions between pathogen molecular motifs and specific host receptors, especially toll-like receptors (TLRs). Flagellin is the main flagellar protein of motile microorganisms and is the ligand of TLR5. The distribution of TLR5 and the actions of flagellin at the systemic level have not been established. Therefore, we determined TLR5 expression and the ability of flagellin to trigger prototypical innate immune responses and apoptosis in major organs from mice. METHODS: Male Balb/C mice (n = 80) were injected intravenously with 1-5 µg recombinant Salmonella flagellin. Plasma and organ samples were obtained after 0.5 to 6 h, for molecular investigations. The expression of TLR5, the activation state of nuclear factor kappa B (NFκB) and mitogen-activated protein kinases (MAPKs) [extracellular related kinase (ERK) and c-jun-NH2 terminal kinase (JNK)], the production of cytokines [tumor necrosis alpha (TNFα), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), macrophage inhibitory protein-2 (MIP-2) and soluble triggering receptor expressed on myeloid cells (TREM-1)], and the apoptotic cleavage of caspase-3 and its substrate Poly(ADP-ribose) polymerase (PARP) were determined in lung, liver, gut and kidney at different time-points. The time-course of plasma cytokines was evaluated up to 6 h after flagellin. RESULTS: TLR5 mRNA and protein were constitutively expressed in all organs. In these organs, flagellin elicited a robust activation of NFκB and MAPKs, and induced significant production of the different cytokines evaluated, with slight interorgan variations. Plasma TNFα, IL-6 and MIP-2 disclosed a transient peak, whereas IL-1ß and soluble TREM-1 steadily increased over 6 h. Flagellin also triggered a marked cleavage of caspase-3 and PARP in the intestine, pointing to its ability to promote significant apoptosis in this organ. CONCLUSIONS: Bacterial flagellin elicits prototypical innate immune responses in mice, leading to the release of multiple pro-inflammatory cytokines in the lung, small intestine, liver and kidney, and also activates apoptotic signalling in the gut. Therefore, this bacterial protein may represent a critical mediator of systemic inflammation and intestinal barrier failure in sepsis due to flagellated micro-organisms.


Subject(s)
Apoptosis/drug effects , Flagellin/pharmacology , Immunity, Innate/drug effects , Systemic Inflammatory Response Syndrome/chemically induced , Animals , Caspase 3/metabolism , Chemokine CXCL2/biosynthesis , Enzyme Activation/drug effects , Extracellular Signal-Regulated MAP Kinases/metabolism , Interleukin-1beta/biosynthesis , JNK Mitogen-Activated Protein Kinases/metabolism , Male , Membrane Glycoproteins/biosynthesis , Mice , Mice, Inbred BALB C , NF-kappa B/biosynthesis , Poly (ADP-Ribose) Polymerase-1 , Poly(ADP-ribose) Polymerases/metabolism , Receptors, Immunologic/biosynthesis , Toll-Like Receptor 6/biosynthesis , Triggering Receptor Expressed on Myeloid Cells-1 , Tumor Necrosis Factor-alpha/biosynthesis
12.
PLoS One ; 5(6): e11403, 2010 Jun 30.
Article in English | MEDLINE | ID: mdl-20613989

ABSTRACT

BACKGROUND: Several pathways that control cell survival under stress, namely RNF8-dependent DNA damage recognition and repair, PCNA-dependent DNA damage tolerance and activation of NF-kappaB by extrinsic signals, are regulated by the tagging of key proteins with lysine 63-based polyubiquitylated chains, catalyzed by the conserved ubiquitin conjugating heterodimeric enzyme Ubc13-Uev. METHODOLOGY/PRINCIPAL FINDINGS: By applying a selection based on in vivo protein-protein interaction assays of compounds from a combinatorial chemical library followed by virtual screening, we have developed small molecules that efficiently antagonize the Ubc13-Uev1 protein-protein interaction, inhibiting the enzymatic activity of the heterodimer. In mammalian cells, they inhibit lysine 63-type polyubiquitylation of PCNA, inhibit activation of NF-kappaB by TNF-alpha and sensitize tumor cells to chemotherapeutic agents. One of these compounds significantly inhibited invasiveness, clonogenicity and tumor growth of prostate cancer cells. CONCLUSIONS/SIGNIFICANCE: This is the first development of pharmacological inhibitors of non-canonical polyubiquitylation that show that these compounds produce selective biological effects with potential therapeutic applications.


Subject(s)
Proteins/metabolism , Ubiquitination , Animals , Catalysis , HeLa Cells , Humans , Mice , Models, Animal , Models, Molecular , NF-kappa B/metabolism , Protein Binding
13.
Am J Physiol Heart Circ Physiol ; 299(2): H492-501, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20525873

ABSTRACT

Acute myocardial dysfunction is a typical manifestation of septic shock. Experimentally, the administration of endotoxin [lipopolysacharride (LPS)] to laboratory animals is frequently used to study such dysfunction. However, a majority of studies used load-dependent indexes of cardiac function [including ejection fraction (EF) and maximal systolic pressure increment (dP/dt(max))], which do not directly explore cardiac inotropism. Therefore, we evaluated the direct effects of LPS on myocardial contractility, using left ventricular (LV) pressure-volume catheters in mice. Male BALB/c mice received an intraperitoneal injection of E. coli LPS (1, 5, 10, or 20 mg/kg). After 2, 6, or 20 h, cardiac function was analyzed in anesthetized, mechanically ventilated mice. All doses of LPS induced a significant drop in LV stroke volume and a trend toward reduced cardiac output after 6 h. Concomitantly, there was a significant decrease of LV preload (LV end-diastolic volume), with no apparent change in LV afterload (evaluated by effective arterial elastance and systemic vascular resistance). Load-dependent indexes of LV function were markedly reduced at 6 h, including EF, stroke work, and dP/dt(max). In contrast, there was no reduction of load-independent indexes of LV contractility, including end-systolic elastance (ejection phase measure of contractility) and the ratio dP/dt(max)/end-diastolic volume (isovolumic phase measure of contractility), the latter showing instead a significant increase after 6 h. All changes were transient, returning to baseline values after 20 h. Therefore, the alterations of cardiac function induced by LPS are entirely due to altered loading conditions, but not to reduced contractility, which may instead be slightly increased.


Subject(s)
Cardiomyopathies/etiology , Endotoxemia/complications , Myocardial Contraction , Ventricular Function, Left , Animals , Arteries/physiopathology , Cardiac Catheterization , Cardiomyopathies/physiopathology , Disease Models, Animal , Dose-Response Relationship, Drug , Elasticity , Endotoxemia/chemically induced , Endotoxemia/physiopathology , Endotoxins/administration & dosage , Heart Rate , Injections, Intraperitoneal , Male , Mice , Mice, Inbred BALB C , Models, Cardiovascular , Stroke Volume , Time Factors , Vascular Resistance , Ventricular Pressure
14.
J Biol Chem ; 285(21): 15746-52, 2010 May 21.
Article in English | MEDLINE | ID: mdl-20299457

ABSTRACT

Redox-based mechanisms play critical roles in the regulation of multiple cellular functions. NF-kappaB, a master regulator of inflammation, is an inducible transcription factor generally considered to be redox-sensitive, but the modes of interactions between oxidant stress and NF-kappaB are incompletely defined. Here, we show that oxidants can either amplify or suppress NF-kappaB activation in vitro by interfering both with positive and negative signals in the NF-kappaB pathway. NF-kappaB activation was evaluated in lung A549 epithelial cells stimulated with tumor necrosis factor alpha (TNFalpha), either alone or in combination with various oxidant species, including hydrogen peroxide or peroxynitrite. Exposure to oxidants after TNFalpha stimulation produced a robust and long lasting hyperactivation of NF-kappaB by preventing resynthesis of the NF-kappaB inhibitor IkappaB, thereby abrogating the major negative feedback loop of NF-kappaB. This effect was related to continuous activation of inhibitor of kappaB kinase (IKK), due to persistent IKK phosphorylation consecutive to oxidant-mediated inactivation of protein phosphatase 2A. In contrast, exposure to oxidants before TNFalpha stimulation impaired IKK phosphorylation and activation, leading to complete prevention of NF-kappaB activation. Comparable effects were obtained when interleukin-1beta was used instead of TNFalpha as the NF-kappaB activator. This study demonstrates that the influence of oxidants on NF-kappaB is entirely context-dependent, and that the final outcome (activation versus inhibition) depends on a balanced inhibition of protein phosphatase 2A and IKK by oxidant species. Our findings provide a new conceptual framework to understand the role of oxidant stress during inflammatory processes.


Subject(s)
Hydrogen Peroxide/pharmacology , NF-kappa B/metabolism , Oxidants/pharmacology , Peroxynitrous Acid/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Animals , Cell Line, Tumor , Humans , I-kappa B Kinase/metabolism , I-kappa B Proteins/metabolism , Inflammation/metabolism , Interleukin-1beta/metabolism , Mice , Phosphorylation/drug effects , Protein Phosphatase 2/metabolism
16.
Virus Res ; 140(1-2): 40-8, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19084562

ABSTRACT

Reverse genetics has facilitated the use of non-segmented negative strand RNA viruses (NNSV) as vectors. Currently, heterologous gene expression necessitates insertion of extra-numeral transcription units (ENTUs), which may alter the NNSV polar transcription gradient and attenuate growth relative to wild-type (Wt). We hypothesized that rescuing recombinant Sendai Virus (rSeV) with a bicistronic gene might circumvent this attenuation but still allow heterologous open reading frame (ORF) expression. Therefore, we used a 9-nucleotide sequence previously described with internal ribosome entry site (IRES) activity, which, when constructed as several repeats, synergistically increased the level of expression of the second cistron [Chappell, S.A., Edelman, G.M., Mauro, V.P., 2000. A 9-nt segment of a cellular mRNA can function as an internal ribosome entry site (IRES) and when present in linked multiple copies greatly enhances IRES activity. Proc. Natl. Acad. Sci. U.S.A. 97, 1536-1541]. We inserted the Renilla luciferase (rLuc) ORF, preceded by 1, 3 or 7 IRES copies, downstream of the SeV N ORF in an infectious clone. Corresponding rSeVs were successfully rescued. Interestingly, bicistronic rSeVs grew as fast as or faster than Wt rSeV. Furthermore, SeV gene transcription downstream of the N/rLuc gene was either equivalent to, or slightly enhanced, compared to Wt rSeV. Importantly, all rSeV/rLuc viruses efficiently expressed rLuc. IRES repetition increased rLuc expression at a multiplicity of infection of 0.1, although without evidence of synergistic enhancement. In conclusion, our approach provides a novel way of insertion and expression of foreign genes in NNSVs.


Subject(s)
Genetic Vectors , RNA/genetics , Recombinant Proteins/biosynthesis , Sendai virus/genetics , Animals , Base Sequence , Cell Line , DNA, Complementary/genetics , Gene Expression Regulation, Viral , Genome, Viral , Humans , Molecular Sequence Data , Nucleocapsid Proteins/genetics , Open Reading Frames , Plasmids , RNA, Viral/genetics , Sendai virus/growth & development , Transcription, Genetic
17.
Eur J Intern Med ; 18(6): 456-62, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17822656

ABSTRACT

The aim of this work was to review the literature concerning cobalamin deficiency in elderly patients. Articles were identified through searches of PubMed-MEDLINE (January 1990 to June 2006), restricted to: English and French language, human subjects, elderly patients (>65 years), clinical trial, review and guidelines. Additional unpublished data from our cohort with cobalamin deficiency at the University Hospital of Strasbourg, France, were also considered. All of the papers and abstracts were reviewed by at least two senior researchers who selected the data used in the study. In elderly people, the main causes of cobalamin deficiency are pernicious anemia and food-cobalamin malabsorption. The recently identified food-cobalamin malabsorption syndrome is a disorder characterized by the inability to release cobalamin from food or from its binding proteins. This syndrome is usually the consequence of atrophic gastritis, related or not to Helicobacter pylori infection, and of the long-term ingestion of antacids and biguanides (in around 60% of the patients). Management of cobalamin deficiency has been well established with the use of cobalamin injections. However, new routes of cobalamin administration (oral and nasal) are currently being developed, especially the use of oral cobalamin therapy to treat food-cobalamin malabsorption.

19.
J Cell Biochem ; 97(3): 572-82, 2006 Feb 15.
Article in English | MEDLINE | ID: mdl-16215985

ABSTRACT

The heterodimeric ubiquitin conjugating enzyme (E2) UBC13-UEV mediates polyubiquitylation through lysine 63 of ubiquitin (K63), rather than lysine 48 (K48). This modification does not target proteins for proteasome-dependent degradation. Searching for potential regulators of this variant polyubiquitylation we have identified four proteins, namely RNF8, KIA00675, KF1, and ZNRF2, that interact with UBC13 through their RING finger domains. These domains can recruit, in addition to UBC13, other E2s that mediate canonical (K48) polyubiquitylation. None of these RING finger proteins were known previously to recruit UBC13. For one of these proteins, RNF8, we show its activity as a ubiquitin ligase that elongates chains through either K48 or K63 of ubiquitin, and its nuclear co-localization with UBC13. Thus, our screening reveals new potential regulators of non-canonical polyubiquitylation.


Subject(s)
DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Lysine/metabolism , Ubiquitin-Conjugating Enzymes/chemistry , Ubiquitin-Conjugating Enzymes/metabolism , Ubiquitin/metabolism , Amino Acid Sequence , Animals , COS Cells , Carcinoma, Hepatocellular/metabolism , Cell Nucleus/metabolism , Chlorocebus aethiops , DNA-Binding Proteins/genetics , HeLa Cells , Humans , Liver Neoplasms/metabolism , Lysine/chemistry , Molecular Sequence Data , Protein Transport , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Sequence Homology, Amino Acid , Two-Hybrid System Techniques , Ubiquitin-Conjugating Enzymes/genetics , Ubiquitin-Protein Ligases
20.
Curr Ther Res Clin Exp ; 66(1): 13-22, 2005 Jan.
Article in English | MEDLINE | ID: mdl-24672108

ABSTRACT

BACKGROUND: Standard treatment of cobalamin (vitamin B12) deficiency involvesregular (1000 µg/mo) IM cyanocobalamin administration. It has been suggested that high-dose (>2000 µg/d) oral cyanocobalamin may be effective in patients with pernicious anemia. OBJECTIVE: The aim of this study was to assess the efficacy and tolerability of oral crystalline cyanocobalamin 1000 µg/d in patients with cobalamin deficiency related to established pernicious anemia. METHODS: This open-label, prospective study was conducted at StrasbourgUniversity Hospital, Strasbourg, France. Patients aged ≥18 years with well-documented cobalamin deficiency related to pernicious anemia were enrolled. Patients received crystalline cyanocobalamin 1000 µg QD PO (capsule) for at least 3 months. Serum cobalamin, folate, iron, and homocysteine concentrations were measured, and a complete blood count was obtained, before (month 0; baseline) and after treatment. RESULTS: Ten patients (7 women, 3 men; mean [SD] age, 72.1 [15.5] years) entered the study. After 3 months of treatment, serum cobalamin concentration increased in all 9 patients in whom it was measured (mean [SD] increase, 117.4 [30.8] pg/mL; P < 0.001 vs baseline). Serum cobalamin concentrations were normalized (>200 pg/mL) in 6 patients. The serum cobalamin concentration was unavailable in 1 patient because of technical problems. Eight patients had increased hemoglobin concentrations (mean [SD] increase, 2.5 [2.4] g/dL; P < 0.01 vs baseline). All 10 patients had decreased mean erythrocyte corpuscular volumes (mean [SD] decrease, 10.4 [6.2] fL; P < 0.003 vs baseline). Four patients received concomitant blood transfusions or folate and iron supplementation. Three patients experienced clinical improvement in paresthesia, reflex abolition, or combined medullary sclerosis (each, 1 patient). CONCLUSION: The results of this small study in patients with cobalamin deficiencyrelated to pernicious anemia suggest that oral crystalline cyanocobalamin 1000 µg/d may be an effective treatment.

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