Efficacy and safety of foscarnet for recurrent orolabial herpes: a multicentre randomized double-blind study.

Foscarnet sodium (trisodium phosphonoformate hexahydrate) has been shown to inhibit herpes simplex virus (HSV) in vitro and to be efficacious for topical treatment of experimental HSV infection in animals. To assess its clinical efficacy in the treatment of recurrent orolabial herpes a multicentre collaborative, double-blind, placebo-controlled trial was conducted. The study patients were randomly assigned to receive either 3% foscarnet cream (78 patients) or placebo (cream vehicle) (75 patients) and were asked to start treatment at the earliest indication of a recurrence. Efficacy was evaluated in 143 patients (74 in the foscarnet group and 69 in the placebo group). There was no significant difference in time to healing or duration of virus shedding between the two groups. However, in the subgroup of patients who started treatment before vesicles appeared, the duration of virus shedding was shorter in the foscarnet group than in the placebo group (p = 0.04), and the proportion of lesions that evolved to the vesicular stage was smaller (p = 0.03). No significant difference in the incidence of local or systemic adverse effects was noted between the two groups. We conclude that the beneficial effect of foscarnet was limited to a subgroup of patients who started treatment in the prevesicular stage.     

Combining bulk segregation analysis and microarrays for mapping of the pH trait in melon

The availability of sequence information for many plants has opened the way to advanced genetic analysis in many non-model plants. Nevertheless, exploration of genetic variation on a large scale and its use as a tool for the identification of traits of interest are still rare. In this study, we combined a bulk segregation approach with our own-designed microarrays to map the pH locus that influences fruit pH in melon. Using these technologies, we identified a set of markers that are genetically linked to the pH trait. Further analysis using a set of melon cultivars demonstrated that some of these markers are tightly linked to the pH trait throughout our germplasm collection. These results validate the utility of combining microarray technology with a bulk segregation approach in mapping traits of interest in non-model plants.     

Identification of single tiny seeds ofOrobanche using RAPD analysis

The tiny seeds of parasitic weeds of the genusOrobanche can be identified by using RAPD markers. A simple procedure for DNA extraction from single seeds, 10 μg each, followed by RAPD-PCR and using specific DNA markers, leads to species identification. Seeds of five different species could be identified using this method.     

RNA polyadenylation and degradation in different Archaea; roles of the exosome and RNase R

Polyadenylation is a process common to almost all organisms. In eukaryotes, stable poly(A)-tails, important for mRNA stability and translation initiation, are added to the 3′ ends of most mRNAs. Contrarily, polyadenylation can stimulate RNA degradation, a phenomenon witnessed in prokaryotes, organelles and recently, for nucleus-encoded RNA as well. Polyadenylation takes place in hyperthermophilic archaea and is mediated by the archaeal exosome, but no RNA polyadenylation was detected in halophiles. Here, we analyzed polyadenylation in the third archaea group, the methanogens, in which some members contain genes encoding the exosome but others lack these genes. Polyadenylation was found in the methanogen, Methanopyrus kandleri, containing the exosome genes, but not in members which lack these genes. To explore how RNA is degraded in the absence of the exosome and without polyadenylation, we searched for the exoribonuclease that is involved in this process. No homologous proteins for any other known exoribonuclease were detected in this group. However, the halophilic archaea contain a gene homologous to the exoribonuclease RNase R. This ribonuclease is not able to degrade structured RNA better than PNPase. RNase R, which appears to be the only exoribonucleases in Haloferax volcanii, was found to be essential for viability.     

Delivery of protein to the cytosol of macrophages using Escherichia coli K-12

Listeriolysin O (LLO) is an essential determinant of pathogenicity whose natural biological role is to mediate lysis of Listeria monocytogenes containing phagosomes. In this study, we report that Escherichia coli expressing cytoplasmic recombinant LLO can efficiently deliver co-expressed proteins to the cytosol of macrophages. We propose a model in which subsequent or concomitant to phagocytosis the E. coli are killed and degraded within phagosomes causing the release of LLO and target proteins from the bacteria. LLO acts by forming large pores in the phagosomal membrane, thus releasing the target protein into the cytosol. Delivery was shown to be rapid, within minutes after phagocytosis. Using this method, a large enzymatically active protein was delivered to the cytosol. Furthermore, we demonstrated that the E. coli/LLO system is very efficient for delivery of ovalbumin (OVA) to the major histocompatibility (MHC) class I pathway for antigen processing and presentation, greater than 4 logs compared with E. coli expressing OVA alone. Moreover, the time required for processing and presentation of an OVA-derived peptide was similar to that previously reported when purified OVA was introduced directly into the cytosol by other methods. Using this system, potentially large amounts of any protein that can be expressed in E. coli can be delivered to the cytosol without protein purification. The potential use of this system for the delivery of antigenic protein in vivo and the delivery of DNA are discussed.