Antibody-coating of bacteria in the urine in relation to various immunologic indexes

Antibody-coating of bacteria in the urine in relation to various immunologic indexes. Little is known about the immunologic aspects of antibody coating, though the test for determining antibody-coated bacteria in urine has been examined for its diagnostic uses by many authors after its inauguration in 1974. In adults with chronic pyelonephritis with and without antibody-coated bacteria in the urine, we tested whether bacterial coating is correlated with the homologous O-antibody titre in the urine. We also determined Ig levels in urine and serum, as well as homologous O-antibody titres in serum. By means of indirect immunofluorescence technique, we were able to show homologous O-antibodies in the urine of all patients with and without antibody-coated bacteria. IgG and IgA levels in urine were mostly raised, as were often the O-antibody titres in the serum. There were no significant differences in the immunologic parameters within the patient groups with or without antibody-coating. The presence of homologous O-antibodies in urine does not therefore necessarily lead to coating of the bacteria.Recouvrement des bactéries par des anticorps en relation avec divers index immunologiques. Les connaissances concernant l'aspect immunologique du recouvrement par des anticorps sont peu nombreuses bien que le test de détection dans l'urine de bactéries recouvertes d'anticorps ait été évalué pour son utilité diagnostique par de nombreux auteurs depuis sa description en 1974. Chez des adultes atteints de pyélonéphrite chronique avec et sans présence dans l'urine de bactéries recouvertes d'anticorps nous avons recherché une corrélation entre ce recouvrement et le titre d'anticorps homologue O dans l'urine. Nous avons aussi déterminé les concentrations d'Ig dans l'urine et le sérum, de même que le titre de l'anticorps homologue O dans le sérum. Au moyen de la technique d'immunofluorescence indirecte nous avons pu mettre en évidence des anticorps homologues O dans les urines de tous les malades, qu'elles contiennent ou non des bactéries recouvertes d'anticorps. Les concentrations d'IgG et d'IgA dans l'urine étaient le plus souvent élevées de même que les titres d'anticorps O dans le sérum. Il n'a pas été observé de différence significative dans les index immunologiques dans les groupes de malades avec ou sans recouvrement des bactéries par des anticorps. La présence d'anticorps homologues O dans l'urine n'implique pas nécessairement le recouvrement des bactéries

A structural determinant required for RNA editing

RNA editing by adenosine deaminases acting on RNAs (ADARs) can be both specific and non-specific, depending on the substrate. Specific editing of particular adenosines may depend on the overall sequence and structural context. However, the detailed mechanisms underlying these preferences are not fully understood. Here, we show that duplex structures mimicking an editing site in the Gabra3 pre-mRNA unexpectedly fail to support RNA editing at the Gabra3 I/M site, although phylogenetic analysis suggest an evolutionarily conserved duplex structure essential for efficient RNA editing. These unusual results led us to revisit the structural requirement for this editing by mutagenesis analysis. In vivo nuclear injection experiments of mutated editing substrates demonstrate that a non-conserved structure is a determinant for editing. This structure contains bulges either on the same or the strand opposing the edited adenosine. The position of these bulges and the distance to the edited base regulate editing. Moreover, elevated folding temperature can lead to a switch in RNA editing suggesting an RNA structural change. Our results indicate the importance of RNA tertiary structure in determining RNA editing

The T7-Related Pseudomonas putida Phage ϕ15 Displays Virion-Associated Biofilm Degradation Properties

Formation of a protected biofilm environment is recognized as one of the major causes of the increasing antibiotic resistance development and emphasizes the need to develop alternative antibacterial strategies, like phage therapy. This study investigates the in vitro degradation of single-species Pseudomonas putida biofilms, PpG1 and RD5PR2, by the novel phage ϕ15, a ‘T7-like virus’ with a virion-associated exopolysaccharide (EPS) depolymerase. Phage ϕ15 forms plaques surrounded by growing opaque halo zones, indicative for EPS degradation, on seven out of 53 P. putida strains. The absence of haloes on infection resistant strains suggests that the EPS probably act as a primary bacterial receptor for phage infection. Independent of bacterial strain or biofilm age, a time and dose dependent response of ϕ15-mediated biofilm degradation was observed with generally a maximum biofilm degradation 8 h after addition of the higher phage doses (104 and 106 pfu) and resistance development after 24 h. Biofilm age, an in vivo very variable parameter, reduced markedly phage-mediated degradation of PpG1 biofilms, while degradation of RD5PR2 biofilms and ϕ15 amplification were unaffected. Killing of the planktonic culture occurred in parallel with but was always more pronounced than biofilm degradation, accentuating the need for evaluating phages for therapeutic purposes in biofilm conditions. EPS degrading activity of recombinantly expressed viral tail spike was confirmed by capsule staining. These data suggests that the addition of high initial titers of specifically selected phages with a proper EPS depolymerase are crucial criteria in the development of phage therapy

The ADAR RNA editing enzyme controls neuronal excitability in Drosophila melanogaster

RNA editing by deamination of specific adenosine bases to inosines during pre-mRNA processing gen-erates edited isoforms of proteins. Recoding RNA editing is more widespread in Drosophila than in vertebrates. Editing levels rise strongly at metamor-phosis, and Adar5G1 null mutant flies lack editing events in hundreds of CNS transcripts; mutant flies have reduced viability, severely defective locomo-tion and age-dependent neurodegeneration. On the other hand, overexpressing an adult dADAR isoform with high enzymatic activity ubiquitously during larval and pupal stages is lethal. Advantage was taken of this to screen for genetic modifiers; Adar overexpression lethality is rescued by reduced dosage of the Rdl (Resistant to dieldrin), gene encoding a subunit of inhibitory GABA receptors. Reduced dosage of the Gad1 gene encoding the GABA synthetase also rescues Adar overexpression lethality. Drosophila Adar5G1 mutant phenotypes are ameliorated by feeding GABA modulators. We demonstrate that neuronal excitability is linked to dADAR expression levels in individual neurons; Adar-overexpressing larval motor neurons show reduced excitability whereas Adar5G1 null mutant or targeted Adar knockdown motor neurons exhibit increased excitability. GABA inhibitory signalling is impaired in human epileptic and autistic conditions, and vertebrate ADARs may have a relevant evolutionarily conserved control over neuronal excitability

Cost-Effective Portfolio Hedging: A Dividend-funded Derivative Approach

This paper examines the effectiveness of using dividend yield to fund hedging protection for an S&P500 equity portfolio. We construct a hedged portfolio that consists of the S&P500 index but uses the dividend yield to purchase put option protection for hedging risk. We then compare the risk and return of the hedged S&P500 portfolio to that of an unhedged S&P500 portfolio. The trade-off reduced returns compared to the overall risk reduction are also measured. Results indicate that this risk-management strategy could be appealing to a large contingency of investors seeking down-side protection at a modest cost that is self-funded from dividends