Search results for "Porin"
showing 10 items of 260 documents
Spatio-temporal pattern of Pentastiridius leporinus migration in an ephemeral cropping system
2010
International audience; * 1 Cixiid planthoppers (Hemiptera: Fulgoromorpha: Cixiidae) are considered to be important economic pests because of their ability to transmit phloem-restricted prokaryotes causing emerging plant diseases worldwide. However, little information is available on the biology and ecology of such species. This is the case for Pentastiridius leporinus (Linnaeus), a cixiid planthopper reported to live on common reed across Countries of Central and Northern Europe. However, in the east of France, the same planthopper species appears to complete its life cycle in the sugar beet-wheat cropping system and has been repeatedly shown to transmit prokaryotic plant pathogens that ar…
Identification and biological traits of a planthopper from the genus Pentastiridius (Hemiptera: Cixiidae) adapted to an annual cropping rotation
2009
International audience; Cixiid planthoppers have been shown to vector phloem-limited prokaryotes associated with plant diseases world-wide. In eastern France, an emerging disease of sugar beet called syndrome basses richesses has been associated with phloem-restricted bacteria transmitted by a cixiid planthopper within the genus Pentastiridius. Early investigation suggested the species being Pentastiridius beieri. On the basis of a morphological and phylogenetic study we report the identification of the planthopper as Pentastiridius leporinus. Furthermore we report some biological traits of the species, which shows a surprising ecological adaptation to an annual cropping rotation sugar beet…
2019
Integral membrane proteins of the aquaporin family facilitate rapid water flux across cellular membranes in all domains of life. Although the water-conducting pore is clearly defined in an aquaporin monomer, all aquaporins assemble into stable tetramers. In order to investigate the role of protomer–protomer interactions, we analyzed the activity of heterotetramers containing increasing fractions of mutated monomers, which have an impaired oligomerization propensity and activity. In order to enforce interaction between the protomers, we designed and analyzed a genetically fused homotetramer of GlpF, the aquaglyceroporin of the bacterium Escherichia coli (E. coli). However, increasing fractio…
Typhoid Fever
2008
Typhoid fever continues to be a serious public health problem, with approximately 22. million cases and more than 200. 000 deaths globally. The disease is most often acquired by ingestion of food or water contaminated by the feces and less frequently by urine or vomitus of patients and carriers. Prolonged low-grade fever, headache, dry cough, alterations of bowel habits, coated tongue, and rose spots are the typical clinical features. Definitive diagnosis requires the isolation of Salmonella enterica serovar Typhi. Supportive serological tests are also used. First-choice antibiotic treatment includes fluoroquinolones or third-generation cephalosporins and reduces the mortality rate from 20%…
NFATc1 releases BCL6-dependent repression of CCR2 agonist expression in peritoneal macrophages fromSaccharomyces cerevisiaeinfected mice
2016
The link between the extensive usage of calcineurin (CN) inhibitors cyclosporin A and tacrolimus (FK506) in transplantation medicine and the increasing rate of opportunistic infections within this segment of patients is alarming. Currently, how peritoneal infections are favored by these drugs, which impair the activity of several signaling pathways including the Ca(++) /CN/NFAT, Ca(++) /CN/cofilin, Ca(++) /CN/BAD, and NF-κB networks, is unknown. Here, we show that Saccharomyces cerevisiae infection of peritoneal resident macrophages triggers the transient nuclear translocation of NFATc1β isoforms, resulting in a coordinated, CN-dependent induction of the Ccl2, Ccl7, and Ccl12 genes, all enc…
Targeted delivery of Cyclosporine A by polymeric nanocarriers improves the therapy of inflammatory bowel disease in a relevant mouse model
2017
The therapy of inflammatory bowel diseases is still rather inefficient, and about 80% of patients require surgery at some stage. Improving the treatments by more efficient medication is, therefore, an urgent medical need. The objective of this project was to demonstrate targeted delivery of Cyclosporine-A (CYA) to the inflamed areas of the intestinal mucosa after oral administration, enabling improved alleviation of the symptoms and, at the same time, reduced systemic drug absorption and associated adverse effects. As had already been demonstrated in previous studies, nano- to micrometer-sized drug particles will accumulate at inflamed mucosal areas, providing a platform for such purposes. …
New microRNA Biomarkers for Drug-Induced Steatosis and Their Potential to Predict the Contribution of Drugs to Non-alcoholic Fatty Liver Disease
2017
Background and Aims: Drug-induced steatosis is a major reason for drug failure in clinical trials and post-marketing withdrawal; and therefore, predictive biomarkers are essential. These could be particularly relevant in non-alcoholic fatty liver disease (NAFLD), where most patients show features of the metabolic syndrome and are prescribed with combined chronic therapies, which can contribute to fatty liver. However, specific biomarkers to assess the contribution of drugs to NAFLD are lacking. We aimed to find microRNAs (miRNAs) responsive to steatotic drugs and to investigate if they could become circulating biomarkers for drug induced steatosis. Methods: Human HepG2 cells were treated wi…
Which non-carbapenem antibiotics are active against extended-spectrum β-lactamase-producing Enterobacteriaceae?
2018
In this study, the activity of 18 non-carbapenem antibiotics was evaluated against 100 extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-Ec) and 50 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) isolated from urinary tract infections and bacteraemia in 2016. Minimum inhibitory concentrations (MICs) were determined using reference methods and the susceptibility profiles were defined according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) 2017 recommendations. All of the ESBL-Ec isolates were susceptible to ceftazidime/avibactam and a great majority of them were susceptible to fosfomycin (98%), piperacillin/tazobactam (97%), amikacin (97%) and nitr…
Reply to Comment on: 'Corneal confocal scanning laser microscopy in patients with dry eye disease treated with topical cyclosporine'
2017
Reply to Comment on: ‘Corneal confocal scanning laser microscopy in patients with dry eye disease treated with topical cyclosporine’
Energy transduction and signal averaging of fluctuating electric fields by a single protein ion channel
2016
[EN] We demonstrate the electrical rectification and signal averaging of fluctuating signals using a biological nanostructure in aqueous solution: a single protein ion channel inserted in the lipid bilayer characteristic of cell membranes. The conversion of oscillating, zero time-average potentials into directional currents permits charging of a load capacitor to significant steady-state voltages within a few minutes in the case of the outer membrane porin F (OmpF) protein, a bacterial channel of Escherichia coli. The experiments and simulations show signal averaging effects at a more fundamental level than the traditional cell and tissue scales, which are characterized by ensembles of many…