Search results for "Erich"
showing 10 items of 805 documents
Cholera-Like Enterotoxins and Regulatory T cells
2010
Cholera toxin (CT) and the heat-labile enterotoxin of E. coli (LT), as well as their non toxic mutants, are potent mucosal adjuvants of immunization eliciting mucosal and systemic responses against unrelated co-administered antigens in experimental models and in humans (non toxic mutants). These enterotoxins are composed of two subunits, the A subunit, responsible for an ADP-ribosyl transferase activity and the B subunit, responsible for cell binding. Paradoxically, whereas the whole toxins have adjuvant properties, the B subunits of CT (CTB) and of LT (LTB) have been shown to induce antigen specific tolerance when administered mucosally with antigens in experimental models as well as, rece…
Biosensor-based kinetic and thermodynamic characterization of opioids interaction with human μ-opioid receptor.
2019
Development of opioid analgesics with minimal side effects requires substantial knowledge on structure-kinetic and -thermodynamic relationship of opioid-receptor interactions. Here, combined kinetics and thermodynamics of opioid agonist binding to human μ-opioid receptor (h-μOR) was investigated using real-time label-free surface plasmon resonance (SPR)-based method. The N-terminal end truncated and C-terminal 6His-tagged h-μOR was constructed and expressed in E. coli. Receptor was purified, detergent-solubilized and characterized by circular dichroism. The uniform immobilization of h-μOR on Ni-NTA chips was achieved using hybrid capture-coupling approach followed by reconstitution in lipid…
Cloning, purification, and nucleotide-binding traits of the catalytic subunit A of the V1VO ATPase from Aedes albopictus.
2007
The Asian tiger mosquito, Aedes albopictus, is commonly infected by the gregarine parasite Ascogregarina taiwanensis, which develops extracellularly in the midgut of infected larvae. The intracellular trophozoites are usually confined within a parasitophorous vacuole, whose acidification is generated and controlled by the V(1)V(O) ATPase. This proton pump is driven by ATP hydrolysis, catalyzed inside the major subunit A. The subunit A encoding gene of the Aedes albopictus V(1)V(O) ATPase was cloned in pET9d1-His(3) and the recombinant protein, expressed in the Escherichia coli Rosetta 2 (DE3) strain, purified by immobilized metal affinity- and ion-exchange chromatography. The purified prote…
Tetrahydroanthraquinone Derivatives from the Endophytic Fungus Stemphylium globuliferm
2015
Four new tetrahydroanthraquinone derivatives, namely, dihydroaltersolanol B (1), dihydroaltersolanol C (2), and the atropisomers acetylalterporriol D (3) and acetylalterporriol E (4), were obtained from the endophytic fungus Stemphylium globuliferum, which was isolated from Juncus acutus growing in Egypt. The structures of the new compounds were unambiguously elucidated on the basis of one- and two-dimensional NMR spectroscopy, as well as by high-resolution mass spectrometry and electronic circular dichroism (ECD) spectroscopy. In addition, seven known anthraquinone derivatives 5–11 were isolated and identified on the basis of their spectral characteristics and by comparison with literature…
An Intercalibration Study of the Use of 4-Methylumbelliferyl-β-D-Glucuronide for the Specific Enumeration of Escherichia coli in Seawater and Marine …
1991
Summary A fluorogenic assay for the specific detection of Escherichia coli on the basis of its β-glucuronidase activity (MUG method) was applied to seawater and marine sediments with different contamination levels. The study was carried out in three Mediterranean areas (Malaga-Spain, Nice-France and Palermo-Sicily), using strictly standardized methods (membrane filtration), media (mFC and Chapman-TTC agars) and reagents, to evaluate statistically its sensitivity and specificity according to the origin and contamination of samples, the workers performing the tests and the selected culture media. The results obtained indicate that the MUG method is highly specific (94.5%) and sensitive (90.8%…
Forme di territori post-metropolitani siciliani: un contesto “al margine”
2013
Il paper tratta gli argomenti affrontati dall’unità di ricerca di Palermo all’interno del progetto PRIN 2010. La ricerca, centrata sui temi dell’abitare nei territori post-metropolitani, intende individuare modalità di risposta e strumenti utili in termini di inclusione, benessere, sicurezza e garanzia di diritti di cittadinanza attraverso l’aggiornamento di strumenti e politiche utili ad affrontare le nuove modalità e geografie dell’abitare. Si tratta di un obiettivo prioritario tanto della strategia Europa 2020 (European Commission, 2010) quanto del programma Horizon 2020; entrambi individuano nella costruzione di una 'società inclusiva, innovativa e sicura' una delle sfide che l’Europa d…
Cloning and Characterization of Overlapping DNA Fragments of the Toxin A Gene of Clostridium difficile
1989
Clostridium difficile, a human pathogen, produces two very large protein toxins, A and B (250-600 kDa), which resist dissociation into subunits. To clone the toxin A gene, a genomic library of 3-8 kb chromosomal DNA fragments of C. difficile strain VPI 10463 established in pUC12 was screened with a rabbit polyclonal toxin A antiserum. Thirty-five clones were isolated which carried 2.5-7.0 kb inserts representing a 10 kb region of the C. difficile genome. All the inserts were oriented in the same direction, suggesting that toxin A gene expression was under control of the lac promoter of the pUC12 vector. Western blot experiments revealed the presence of low amounts of fusion proteins of vari…
Der Einflu� von Antibiotica auf die �berlebensrate von Mikroorganismen bei tiefen Temperaturen
1959
Die Lebendkeimzahl in einer Suspension vonE. coli nimmt bei +4°C langsam zu, nimmt bei-5°C wenig ab und fallt bei-19°C innerhalb von 24 Std stark, wahrend die Verringerung in den folgenden Tagen nur noch gering ist. Streptomycin und Penicillin vermindern in allen 3 Temperaturbereichen die Keimkonzentration in Abhangigkeit von der Antibioticumkonzentration. Subbakteriostatische Konzentrationen von Streptomycin haben bei-19°C eine zusatzliche Wirkung. Die Resistenz der in uberbakteriostatischen Antibioticakonzentrationen bei diesen Temperaturen uberlebenden Keime ist gegenuber dem Ausgangsstamm weder erhoht noch vermindert.
Behavior of four main dairy pathogenic bacteria during manufacturing and ripening of pecorino siciliano cheese
2020
Background: Consumption of raw cheese may be associated with different diseases. This study aimed to evaluate behavior of four pathogenic bacteria during manufacture and ripening of Protected Designation of Origin (PDO) Pecorino Siciliano cheese.
 Methods: The experimental cheese groups were inoculated with pathogenic bacteria, including Escherichia coli O157, Listeria monocytogenes, Salmonella Enteritidis, and Staphylococcus aureus. The cheese making processes were monitored from milk curdling until 3 months ripened cheeses and the levels of Lactic Acid Bacteria (LAB) and the four dairy pathogens were evaluated by plate counts. Randomly Amplified Polymorphic DNA (RAPD)-Polymerase Chai…
Bacterial endosymbionts of insects: insights from comparative genomics.
2004
The development of molecular techniques for the study of uncultured bacteria allowed the extensive study of the widespread association between insects and intracellular symbiotic bacteria. Most of the bacterial endosymbionts involved in such associations are gamma-proteobacteria, closely related to Escherichia coli. In recent years, five genomes from insect endosymbionts have been sequenced, allowing the performance of extensive genome comparative analysis that, as a complement of phylogenetic studies, and analysis on individual genes, can help to understand the different traits of this particular association, including how the symbiotic process is established, the explanation of the specia…