scholarly journals Study of Macrophage Functions in Murine J774 Cells and Human Activated THP-1 Cells Exposed to Oritavancin, a Lipoglycopeptide with High Cellular Accumulation

2014 ◽  
Vol 58 (4) ◽  
pp. 2059-2066 ◽  
Author(s):  
Sandrine Lemaire ◽  
Marie-Paule Mingeot-Leclercq ◽  
Paul M. Tulkens ◽  
Françoise Van Bambeke
Keyword(s):  
Metabolic Activity ◽  
Latex Bead ◽  
Phase Iii ◽  
Current Phase ◽  
Pharmacokinetic Studies ◽  
Ros Production ◽  
Phagocytic Capacity ◽  
Content Type ◽  
Cellular Accumulation ◽  
J774 Cells

ABSTRACTOritavancin, a lipoglycopeptide antibiotic in development, accumulates to high levels in the lysosomes of eukaryotic cells. We examined specific functions of macrophages (phagocytic capacity, lysosomal integrity, metabolic activity, and production of reactive oxygen species [ROS]) in correlation with the cellular accumulation of the drug, using J774 mouse macrophages and THP-1 human monocytes differentiated into macrophages using phorbol 12-myristate 13-acetate. Oritavancin did not affectPseudomonas aeruginosaphagocytosis, lysosomal integrity, or metabolic activity in cells incubated for 3 h with extracellular concentrations ranging from 5 to 50 μg/ml. At extracellular concentrations of ≥25 μg/ml, oritavancin reduced latex bead phagocytosis by approximately 50% and doubled ROS production in J774 macrophages only. This may result from the fact that the cellular accumulation of oritavancin was 15 times higher in J774 cells than in activated THP-1 cells at 3 h. Human pharmacokinetic studies estimate that the concentration of oritavancin in alveolar macrophages could reach approximately 560 μg/ml after administration of a cumulative dose of 4 g, which is below the cellular concentration needed in the present study to impair latex bead phagocytosis (1,180 μg/ml) or to stimulate ROS production (15,000 μg/ml) by J774 cells. The data, therefore, suggest that, in spite of its substantial cellular accumulation, oritavancin is unlikely to markedly affect macrophage functions under the conditions of use investigated in current phase III trials (a single dose of 1,200 mg).

scholarly journals In VitroAnalyses of the Effects of Heparin and Parabens on Candida albicans Biofilms and Planktonic Cells

2011 ◽  
Vol 56 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Marisa H. Miceli ◽  
Stella M. Bernardo ◽  
T. S. Neil Ku ◽  
Carla Walraven ◽  
Samuel A. Lee
Keyword(s):  
Candida Albicans ◽  
Metabolic Activity ◽  
Biofilm Formation ◽  
High Dose ◽  
Dependent Manner ◽  
Planktonic Cells ◽  
Content Type ◽  
Heparin Sodium ◽  
The Individual

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.

scholarly journals Quality assurance of radiotherapy in the ongoing EORTC 1420 “Best of” trial for early stage oropharyngeal, supraglottic and hypopharyngeal carcinoma: results of the benchmark case procedure

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
J-J Stelmes ◽  
E. Vu ◽  
V. Grégoire ◽  
C. Simon ◽  
E. Clementel ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Early Stage ◽  
Prospective Trial ◽  
Similarity Index ◽  
Phase Iii ◽  
Current Phase ◽  
Hypopharyngeal Carcinoma ◽  
Transoral Surgery ◽  
Swallowing Function ◽  
The Impact

Abstract Introduction The current phase III EORTC 1420 Best-of trial (NCT02984410) compares the swallowing function after transoral surgery versus intensity modulated radiotherapy (RT) in patients with early-stage carcinoma of the oropharynx, supraglottis and hypopharynx. We report the analysis of the Benchmark Case (BC) procedures before patient recruitment with special attention to dysphagia/aspiration related structures (DARS). Materials and methods Submitted RT volumes and plans from participating centers were analyzed and compared against the gold-standard expert delineations and dose distributions. Descriptive analysis of protocol deviations was conducted. Mean Sorensen-Dice similarity index (mDSI) and Hausdorff distance (mHD) were applied to evaluate the inter-observer variability (IOV). Results 65% (23/35) of the institutions needed more than one submission to achieve Quality assurance (RTQA) clearance. OAR volume delineations were the cause for rejection in 53% (40/76) of cases. IOV could be improved in 5 out of 12 OARs by more than 10 mm after resubmission (mHD). Despite this, final IOV for critical OARs in delineation remained significant among DARS by choosing an aleatory threshold of 0.7 (mDSI) and 15 mm (mHD). Conclusions This is to our knowledge the largest BC analysis among Head and neck RTQA programs performed in the framework of a prospective trial. Benchmarking identified non-common OARs and target delineations errors as the main source of deviations and IOV could be reduced in a significant number of cases after this process. Due to the substantial resources involved with benchmarking, future benchmark analyses should assess fully the impact on patients’ clinical outcome.

scholarly journals Inositol-Requiring Enzyme 1-Dependent Activation of AMPK Promotes Brucella abortus Intracellular Growth

2016 ◽  
Vol 198 (6) ◽  
pp. 986-993 ◽  
Author(s):  
Ning Liu ◽  
Yingying Li ◽  
Chunyan Dong ◽  
Xiaohan Xu ◽  
Pan Wei ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Underlying Mechanism ◽  
Peritoneal Macrophages ◽  
Dependent Manner ◽  
Ros Production ◽  
Ampk Activation ◽  
Intracellular Growth ◽  
Serine Threonine Kinase ◽  
Content Type ◽  
Amp Activated Protein Kinase

ABSTRACTAMP-activated protein kinase (AMPK) is a serine/threonine kinase that is well conserved during evolution. AMPK activation inhibits production of reactive oxygen species (ROS) in cells via suppression of NADPH oxidase. However, the role of AMPK during the process ofBrucellainfection remains unknown. Our data demonstrate thatB. abortusinfection induces AMPK activation in HeLa cells in a time-dependent manner. The known AMPK kinases LKB1, CAMKKβ, and TAK1 are not required for the activation of AMPK byB. abortusinfection. Instead, this activation is dependent on the RNase activity of inositol-requiring enzyme 1 (IRE1). Moreover, we also found thatB. abortusinfection-induced IRE1-dependent activation of AMPK promotesB. abortusintracellular growth with peritoneal macrophages via suppression of NADPH-derived ROS production.IMPORTANCEPrevious studies showed thatB. abortusinfection does not promote any oxidative burst regulated by NADPH oxidase. However, the underlying mechanism remains elusive. We report for the first time that AMPK activation caused byB. abortusinfection plays important role in NADPH oxidase-derived ROS production.

scholarly journals Microinjection of Francisella tularensis and Listeria monocytogenes Reveals the Importance of Bacterial and Host Factors for Successful Replication

2015 ◽  
Vol 83 (8) ◽  
pp. 3233-3242 ◽  
Author(s):  
Lena Meyer ◽  
Jeanette E. Bröms ◽  
Xijia Liu ◽  
Martin E. Rottenberg ◽  
Anders Sjöstedt
Keyword(s):  
Listeria Monocytogenes ◽  
Francisella Tularensis ◽  
Hela Cells ◽  
Cell Types ◽  
Metabolic Adaptation ◽  
Content Type ◽  
Bacterial Uptake ◽  
J774 Cells ◽  
Cell Cytosol ◽  
Successful Replication

Certain intracellular bacteria use the host cell cytosol as the replicative niche. Although it has been hypothesized that the successful exploitation of this compartment requires a unique metabolic adaptation, supportive evidence is lacking. ForFrancisella tularensis, many genes of theFrancisellapathogenicity island (FPI) are essential for intracellular growth, and therefore, FPI mutants are useful tools for understanding the prerequisites of intracytosolic replication. We compared the growth of bacteria taken up by phagocytic or nonphagocytic cells with that of bacteria microinjected directly into the host cytosol, using the live vaccine strain (LVS) ofF. tularensis; five selected FPI mutants thereof, i.e., ΔiglA, ΔiglÇ ΔiglG, ΔiglI, and ΔpdpEstrains; andListeria monocytogenes. After uptake in bone marrow-derived macrophages (BMDM), ASC−/−BMDM, MyD88−/−BMDM, J774 cells, or HeLa cells, LVS, ΔpdpEand ΔiglGmutants, andL. monocytogenesreplicated efficiently in all five cell types, whereas the ΔiglAand ΔiglCmutants showed no replication. After microinjection, all 7 strains showed effective replication in J774 macrophages, ASC−/−BMDM, and HeLa cells. In contrast to the rapid replication in other cell types,L. monocytogenesshowed no replication in MyD88−/−BMDM and LVS showed no replication in either BMDM or MyD88−/−BMDM after microinjection. Our data suggest that the mechanisms of bacterial uptake as well as the permissiveness of the cytosolic compartmentper seare important factors for the intracytosolic replication. Notably, none of the investigated FPI proteins was found to be essential for intracytosolic replication after microinjection.

scholarly journals Methanogens and Methanogenesis in the Rumens and Ceca of Lambs Fed Two Different High-Grain-Content Diets

2012 ◽  
Vol 79 (6) ◽  
pp. 1777-1786 ◽  
Author(s):  
M. Popova ◽  
D. P. Morgavi ◽  
C. Martin
Keyword(s):  
Metabolic Activity ◽  
Methane Production ◽  
Direct Evidence ◽  
Species Level ◽  
Ex Situ ◽  
Content Type ◽  
Copy Numbers ◽  
Dietary Starch ◽  
Induced Changes

ABSTRACTThe amount and nature of dietary starch are known to influence the extent and site of feed digestion in ruminants. However, how starch degradability may affect methanogenesis and methanogens along the ruminant's digestive tract is poorly understood. This study examined the diversity and metabolic activity of methanogens in the rumen and cecum of lambs receiving wheat or corn high-grain-content diets. Methane productionin vivoandex situwas also monitored.In vivodaily methane emissions (CH4g/day) were 36% (P< 0.05) lower in corn-fed lambs than in wheat-fed lambs.Ex situmethane production (μmol/h) was 4-fold higher for ruminal contents than for cecal contents (P< 0.01), while methanogens were 10-fold higher in the rumen than in the cecum (mcrAcopy numbers;P< 0.01). Clone library analysis indicated thatMethanobrevibacterwas the dominant genus in both sites. Diet induced changes at the species level, as theMethanobrevibacter millerae-M. gottschalkii-M. smithiiclade represented 78% of the sequences from the rumen of wheat-fed lambs and just about 52% of the sequences from the rumen of the corn-fed lambs. Diet did not affectmcrAexpression in the rumen. In the cecum, however, expression was 4-fold and 2-fold lower than in the rumen for wheat- and corn-fed lambs, respectively. Though we had no direct evidence for compensation of reduced rumen methane production with higher cecum methanogenesis, the ecology of methanogens in the cecum should be better considered.

scholarly journals In Vivo Pharmacodynamic Characterization of a Novel Odilorhabdin Antibiotic, NOSO-502, against Escherichia coli and Klebsiella pneumoniae in a Murine Thigh Infection Model

2018 ◽  
Vol 62 (9) ◽  
Author(s):  
Miao Zhao ◽  
Alexander J. Lepak ◽  
Karen Marchillo ◽  
Jamie VanHecker ◽  
David R. Andes
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Subcutaneous Administration ◽  
Dose Fractionation ◽  
Infection Model ◽  
Pharmacokinetic Studies ◽  
Time Curve ◽  
Content Type ◽  
The Mean

ABSTRACT NOSO-502 is a novel odilorhabdin antibiotic with potent activity against Enterobacteriaceae. The goal of these studies was to determine which pharmacokinetic/pharmacodynamic (PK/PD) indices and magnitude best correlated with efficacy in the murine thigh infection model. Six Escherichia coli and 6 Klebsiella pneumoniae isolates were utilized. MICs were determined using CLSI methods and ranged from 1 to 4 mg/liter. A neutropenic murine thigh infection model was utilized for all treatment studies. Single-dose plasma pharmacokinetics were determined in mice after subcutaneous administration of 7.81, 31.25, 125, and 500 mg/kg of body weight. Pharmacokinetic studies exhibited peak concentration (Cmax) values of 1.49 to 84.6 mg/liter, area under the concentration-time curve from 0 h to infinity (AUC0–∞) values of 1.94 to 352 mg · h/liter, and beta elimination half-lives of 0.41 to 1.1 h. Dose fractionation studies were performed using total drug doses of 7.81 mg/kg to 2,000 mg/kg fractionated into regimens of every 3 h (q3h), q6h, q12h, or q24h. Nonlinear regression analysis demonstrated that AUC/MIC was the PK/PD parameter that best correlated with efficacy (R2, 0.86). In subsequent studies, we used the neutropenic murine thigh infection model to determine the magnitude of NOSO-502 AUC/MIC needed for the efficacy against a diverse group of Enterobacteriaceae. Mice were treated with 4-fold-increasing doses (range, 3.91 to 1,000 mg/kg) of NOSO-502 every 6 h. The mean 24-h free-drug AUC/MIC (fAUC)/MIC) magnitudes associated with net stasis and 1-log kill endpoint for K. pneumoniae were 4.22 and 17.7, respectively. The mean fAUC/MIC magnitude associated with net stasis endpoint for E. coli was 10.4. NOSO-502 represents a promising novel, first-in-class odilorhabdin antibiotic with in vivo potency against Enterobacteriaceae.

scholarly journals Candida guilliermondii Complex Is Characterized by High Antifungal Resistance but Low Mortality in 22 Cases of Candidemia

2017 ◽  
Vol 61 (7) ◽  
Author(s):  
Laura Judith Marcos-Zambrano ◽  
Mireia Puig-Asensio ◽  
Felipe Pérez-García ◽  
Pilar Escribano ◽  
Carlos Sánchez-Carrillo ◽  
...  
Keyword(s):  
Metabolic Activity ◽  
Biofilm Formation ◽  
Galleria Mellonella ◽  
Sensu Stricto ◽  
Candida Guilliermondii ◽  
Molecular Techniques ◽  
Content Type ◽  
Content Model ◽  
Crystal Violet Assay

ABSTRACT The objectives of our study were to describe the characteristics of patients with Candida guilliermondii candidemia and to perform an in-depth microbiological characterization of isolates and compare them with those of patients with C. albicans candidemia. We described the risk factors and outcomes of 22 patients with candidemia caused by the C. guilliermondii complex. Incident isolates were identified using molecular techniques, and susceptibility to fluconazole, anidulafungin, and micafungin was studied. Biofilm formation was measured using the crystal violet assay (biomass production) and the XTT reduction assay (metabolic activity), and virulence was studied using the Galleria mellonella model. Biofilm formation was compared with that observed for C. albicans. The main conditions predisposing to infection were malignancy (68%), immunosuppressive therapy (59%), and neutropenia (18%). Clinical presentation of candidemia was less severe in patients infected by the C. guilliermondii complex than in patients infected by C. albicans, and 30-day mortality was lower in C. guilliermondii patients (13.6% versus 33.9%, respectively; P = 0.049). Isolates were identified as C. guilliermondii sensu stricto (n = 17) and Candida fermentati (n = 5). The isolates produced biofilms with low metabolic activity and moderate biomass. The G. mellonella model showed that C. guilliermondii was less virulent than C. albicans (mean of 6 days versus 1 day of survival, respectively; P < 0.001). Patients with candidemia caused by the C. guilliermondii complex had severe and debilitating underlying conditions. Overall, the isolates showed diminished susceptibility to fluconazole and echinocandins, although poor biofilm formation and the low virulence were associated with a favorable outcome.

scholarly journals Amifampridine for the Management of Lambert-Eaton Myasthenic Syndrome: A New Take on an Old Drug

2019 ◽  
Vol 54 (1) ◽  
pp. 56-63
Author(s):  
Connie H. Yoon ◽  
Jocelyn Owusu-Guha ◽  
Adam Smith ◽  
Pamela Buschur
Keyword(s):  
English Language ◽  
Human Subjects ◽  
Data Extraction ◽  
Phase Iii ◽  
Pharmacokinetic Studies ◽  
First Line ◽  
Two Phase ◽  
Phase Iii Trials ◽  
Improved Stability ◽  
Myasthenic Syndrome

Objective: The purpose of this article is to review the literature for both 3,4-diaminopyridine (3,4-DAP) and amifampridine for the treatment of Lambert-Eaton myasthenic syndrome (LEMS). Amifampridine (Firdapse) is the salt form of 3,4-DAP and was approved by the Food and Drug Administration for the treatment of LEMS. Data Sources: PubMed, TRIP database, and EMBASE searches were conducted without a back date (current to June 2019) utilizing the following search terms: amifampridine, 3,4-diaminopyridine, and Lambert-Eaton myasthenic syndrome. Completed trials were also reviewed at clinicaltrials.gov. Study Selection and Data Extraction: Criteria for article inclusion consisted of human subjects, age ≥18 years, phase II or III clinical trials, and English language for both drugs. Observational and pharmacokinetic studies for amifampridine were also included. Data Synthesis: Prior to the approval of amifampridine, 3,4-DAP was first-line for the management of LEMS symptoms. Two phase III trials have evaluated amifampridine to confirm efficacy, both showing superiority over placebo in the management of LEMS symptoms, with minimal adverse effects. A significant improvement in both quantitative myasthenia gravis scores and Subjective Global Impression scores was established at days 4 and 14. Relevance to Patient Care and Clinical Practice: With an improved stability profile and decreased dose variability, amifampridine will likely assume the role of first-line management of LEMS. Conclusions: Amifampridine has been shown to improve symptoms of LEMS and is generally well tolerated.

China and Russia tactics will undercut their vaccines

2020 ◽  
Keyword(s):  
Vaccine Development ◽  
Phase Iii ◽  
Trust In Government ◽  
Biomedical Technology ◽  
Content Type ◽  
National Pride ◽  
Spheres Of Influence ◽  
Global Demand ◽  
The World ◽  
Phase Iii Trials

Significance For Russia, it would be a chance for international acclaim and to stoke national pride. For China, success would offset its shortcomings in responding to the emergence of COVID-19 and would demonstrate superior biomedical technology to the world and its own citizens. These two governments' efforts can influence the speed at which the pandemic is brought under control. Impacts Multiple successful vaccines would help overcome production and logistical challenges to meet global demand. The value of vaccine development companies is likely to be volatile, as phase III trials and results are reported over the next few months. Western states will be reluctant to take Chinese or Russian vaccines. Some regional vaccine blocs, mirroring global powers' spheres of influence, could emerge. Moscow may use disinformation to sow distrust of vaccines in Western countries, slowing innoculations and eroding trust in government.

Increase of metabolic activity and disruption of normal contractile protein distribution by bilirubin oxidation products in vascular smooth-muscle cells

2004 ◽  
Vol 100 (3) ◽  
pp. 505-511 ◽  
Author(s):  
Melissa A. Lyons ◽  
Rakesh Shukla ◽  
Kejun Zhang ◽  
Gail J. Pyne ◽  
Meha Singh ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Cerebral Vasospasm ◽  
Metabolic Activity ◽  
Oxidative Metabolism ◽  
Vascular Remodeling ◽  
Oxidation Products ◽  
Content Type ◽  
Ldh Release ◽  
Fine Print

Object. Cerebral vasospasm is a common cause of morbidity and death following aneurysmal subarachnoid hemorrhage (SAH). Previous research has shown that bilirubin oxidation products (BOXes) are present in the cerebral spinal fluid in patients with SAH-induced cerebral vasospasm and can contribute to vasoconstriction and vasospasm in vitro and in vivo. The events leading to cerebral vasospasm are not understood; however, one component of the occlusion may be due to vascular remodeling. In this study the authors have investigated the actions of BOXes, okadaic acid ([OA], a phosphatase inhibitor), and phorbol-12 myristate-13 acetate ([PMA], a protein kinase activator) on vascular smooth-muscle cell (VSMC) morphology and metabolism. Methods. Immunohistochemical analysis was performed to assess VSMC morphology and α–smooth-muscle actin (αSMA) distribution following the application of BOXes, OA, or PMA. Changes in the level of lactate dehydrogenase (LDH) release and oxidative metabolism were also measured. The BOXes, OA, or PMA caused VSMCs to change their shape and exhibit altered αSMA distribution. These treatments increased LDH release (p < 0.05), which is an index of increased cell stress. Oxidative metabolism significantly increased at low and high doses of BOXes, that is, 143 ± 8.5% and 180 ± 11.8%, respectively (p < 0.0001). Both PMA and OA also caused a significant increase in metabolism. Conclusions. The authors concluded that BOXes, OA, and PMA alter VSMC morphology and metabolic activity, events that have been observed during vascular remodeling. Although the mechanism remains unclear, the results indicate that BOXes may play a role in the vascular remodeling that occurs following aneurysmal SAH.

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