Search results for "bacteri"
showing 10 items of 5466 documents
Delivery of proteins into living cells by reversible membrane permeabilization with streptolysin-O
2001
The pore-forming toxin streptolysin O (SLO) can be used to reversibly permeabilize adherent and nonadherent cells, allowing delivery of molecules with up to 100 kDa mass to the cytosol. Using FITC-labeled albumin, 10 5 –10 6 molecules were estimated to be entrapped per cell. Repair of toxin lesions depended on Ca 2+ -calmodulin and on intact microtubules, but was not sensitive to actin disruption or to inhibition of protein synthesis. Resealed cells were viable for days and retained the capacity to endocytose and to proliferate. The active domains of large clostridial toxins were introduced into three different cell lines. The domains were derived from Clostridium difficile B-toxin and Clo…
Inhibition of small G proteins of the Rho family by statins orClostridium difficiletoxin B enhances cytokine-mediated induction of NO synthase II
2000
In order to investigate the involvement of Ras and/or Rho proteins in the induction of the inducible isoform of nitric oxide synthase (NOS II) we used HMG-CoA reductase inhibitors (statins) and Clostridium difficile toxin B (TcdB) as pharmacological tools. Statins indirectly inhibit small G proteins by preventing their essential farnesylation (Ras) and/or geranylgeranylation (Rho). In contrast, TcdB is a glucosyltransferase and inactivates Rho-proteins directly. Human A549/8- and DLD-1 cells as well as murine 3T3 fibroblasts were preincubated for 18 h with statins (1–100 μM) or TcdB (0.01–10 ng ml−1). Then NOS II expression was induced by cytokines. NOS II mRNA was measured after 4–8 h by R…
Activation of astroglial phospholipase D activity by phorbol ester involves ARF and Rho proteins.
2000
Primary cultures of rat cortical astrocytes express phospholipase D (PLD) isoforms 1 and 2 as determined by RT-PCR and Western blot. Basal PLD activity was strongly (10-fold) increased by 4beta-phorbol-12beta,13alpha-dibutyrate (PDB) (EC(50): 56 nM), an effect which was inhibited by Ro 31-8220 (0.1-1 microM), an inhibitor of protein kinase C (PKC), and by brefeldin A (10-100 microg/ml), an inhibitor of ADP-ribosylating factor (ARF) activation. Pretreatment of the cultures with Clostridium difficile toxin B-10463 (0.1-1 ng/ml), which inactivates small G proteins of the Rho family, led to a breakdown of the astroglial cytoskeleton; concomitantly, PLD activation by PDB was reduced by up to 50%…
Metabotropic glutamate receptors activate phospholipase D in astrocytes through a protein kinase C-dependent and Rho-independent pathway.
2003
Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors that mediate phospholipase D (PLD) activation in brain, but the mechanism underlying this response remains unclear. Here we used primary cultures of astrocytes as a cell model to explore the mechanism that links mGluRs to PLD. Glutamate activated both phospholipase C (PLC) and PLD with equal potency and this effect was mimicked by L-cysteinesulfinic acid, a putative neurotransmitter previously shown to activate mGluRs coupled to PLD, but not PLC, in adult brain. PLD activation by glutamate was dependent on Ca(2+) mobilization and fully blocked by both protein kinase C (PKC) inhibitors and PKC down-regulation, suggesti…
Maladie du huanglongbing
2019
Maladie du huanglongbing. Analyse du risque phytosanitaire pour l’Union européenne
Evaluation of the spectral characteristics, purity and antioxidant activity of C-phycocyanin from the cyanobacteria collected in Kaunas Lagoon (Lithu…
2022
The physicochemical characteristics of phycocyanin extracted from cyanobacteria collected in Kaunas Lagoon were studied (spectrum characteristics, C-PC content in the dry mass and chemical purity). It was determined that the tested concentrations of C-PC in purified water should be in the range of 0.02–0.16% for measuring C-PC content in the dry mass and its spectrum characteristics. The two clear absorption maxima were detected in the spectrum of C-PC at the wavelengths of 277 and 619 nm. The content of C-PC in the dry powder form was in the range of 7.25% to 9.30% depending on its concentration in the solution and type of spectrophotometer. Furthermore, a purity factor of 1.5 was calculat…
Systematic review and meta-analysis of the efficacy and safety of minocycline in schizophrenia
2017
ObjectiveOur aim was to perform an updated systematic review and meta-analysis on the efficacy and safety of adjunctive minocycline as a treatment of schizophrenia.MethodsWe conducted a PubMed/Scopus database search from inception to 3 February 2016 for randomized, placebo-controlled trials (RCTs), open non-randomized studies, and case reports/series evaluating minocycline in patients with schizophrenia. Random-effects meta-analysis of positive, negative, depressive, and cognitive symptom rating scales, discontinuation and adverse effects rates calculating standardized mean difference (SMD), and risk ratios±95% confidence intervals (CI95%) were calculated.ResultsSix RCTs were eligible (mino…
Enterobacteris en productes vegetals frescos: resistències als antibiòtics
2015
En aquest treball s’ha estudiat la presència d’enterobacteris en productes vegetals frescos que poden consumir-se directament, sense tractaments que poden afectar a la viabilitat dels microorganismes presents en aquests vegetals. Com material d’estudi s’han seleccionat una sèrie de verdures i hortalisses que habitualment poden consumir-se crues (tomates, enciams, rúcula, canonges, etc.), adquirides en distints establiments de la ciutat de València i els seus voltants, ja que la zona de l’horta de València es caracteritza, a més de per la qualitat i quantitat de la producció hortícola, per l’ús de pràctiques agrícoles (com l’ús de fem com adob) que afavoreixen la contaminació dels vegetals a…
Cyano-Phycocyanin: Mechanisms of Action on Human Skin and Future Perspectives in Medicine
2022
Cyano-phycocyanin is one of the active pigments of the blue-green algae and is usually isolated from the filamentous cyanobacteria Arthrospira platensis Gomont (Spirulina). Due to its multiple physiological functions and non-toxicity, cyano-phycocyanin may be a potential substance for the topical treatment of various skin diseases. Considering that the conventional medicine faces drug resistance, insufficient efficacy and side effects, the plant origin compounds can act as an alternative option. Thus, the aim of this paper was to review the wound healing, antimicrobial, antioxidative, anti-inflammatory, antimelanogenic and anticancer properties and mechanisms of cyano-phycocyanin topical ac…
Biodegradation of organophosphorus pesticides by soil bacteria.
2009
A number of studies in the 1980s and 1990s showed that crop-protection products, applied to drained fields, could move downwards through the soil profile and to the groundwater. Organophosphorus insecticides (OPs) are used all over the world for crop protection, for other agricultural practices such as sheep dipping and, in aquaculture, for the control of sea lice. Ops besides showing a specific neurotoxicity and have also been related to various modern diseases, including Creutzfeldt–Jakob (CJD) and the Gulf War syndrome. Although OPs are less persistent than Organoclorine pesticides (OCs), they still constitute an environmental risks thus increasing the social concern about their levels i…