Recombinant Measles Viruses Defective for RNA Editing and V Protein Synthesis Are Viable in Cultured Cells

AbstractThe measles virus (MV) phosphoprotein (P) gene encodes three proteins, P, C, and V. The V protein is synthesized by pseudo-templated transcription, also designated as RNA editing: during P gene transcription one G residue is inserted at a defined position in about 50% of the mRNAs. To study the importance of sequence elements for the nontemplated G insertion, we generated recombinant MVs in which six different mutations were introduced within the region where editing occurs (3′ UUUUUCCC, template strand). These viruses were then analyzed for their ability to edit their P mRNA and to produce V protein. Single U to C changes within the U stretch abolished editing. Extending the template by three C residues at the site of G insertion resulted in a less precise editing phenotype and overproduction of V. None of these mutants were impaired in their multiplication behavior when analyzed in cultured cells. However, the syncytia of a recombinant MV overproducing V protein were in general smaller and lysed 1 to 2 days later than usual

Serial lactate and admission SOFA scores in trauma: an analysis of predictive value in 724 patients with and without traumatic brain injury

Objective: Arterial lactate, base excess (BE), lactate clearance, and Sequential Organ Failure Assessment (SOFA) score have been shown to correlate with outcome in severely injured patients. The goal of the present study was to separately assess their predictive value in patients suffering from traumatic brain injury (TBI) as opposed to patients suffering from injuries not related to the brain. Materials and methods: A total of 724 adult trauma patients with an Injury Severity Score (ISS)≥16 were grouped into patients without TBI (non-TBI), patients with isolated TBI (isolated TBI), and patients with a combination of TBI and non-TBI injuries (combined injuries). The predictive value of the above parameters was then analyzed using both uni- and multivariate analyses. Results: The mean age of the patients was 39years (77% males), with a mean ISS of 32 (range 16-75). Mortality ranged from 14% (non-TBI) to 24% (combined injuries). Admission and serial lactate/BE values were higher in non-survivors of all groups (all p<0.01), but not in patients with isolated TBI. Admission SOFA scores were highest in non-survivors of all groups (p=0.023); subsequently septic patients also showed elevated SOFA scores (p<0.01), except those with isolated TBI. In this group, SOFA score was the only parameter which showed significant differences between survivors and non-survivors. Receiver operating characteristic (ROC) analysis revealed lactate to be the best overall predictor for increased mortality and further septic complications, irrespective of the leading injury. Conclusion: Lactate showed the best performance in predicting sepsis or death in all trauma patients except those with isolated TBI, and the differences were greatest in patients with substantial bleeding. Following isolated TBI, SOFA score was the only parameter which could differentiate survivors from non-survivors on admission, although the SOFA score, too, was not an independent predictor of death following multivariate analysi

Ponazuril Inhibits the Development of Eimeria Vermiformis in Experimentally Infected Outbred Swiss Mice

We evaluated a 15% paste formulation of ponazuril in outbred Swiss mice that were experimentally infected with Eimeria vermiformis. Thirty, 8-week-old female mice (approximately 20 g) were placed in one group of 10 mice and one group of 20 mice. Mice in both groups were gavaged with approximately 5,000 sporulated oocysts of E. vermiformis on day 0. Mice in group 2 (n=10) were treated orally on days 3 and 4 with ponazuril (suspended in 30% propylene glycol) at the rate of 20 mg/kg. Mice in group 1 (n=20) were gavaged with a similar volume of 30% propylene glycol. Rates of oocyst passage (oocysts/g feces) were determined on day 10 (peak patency) for treated and nontreated mice using a fecal aliquot oocyst counting technique. Oocysts were not observed in the feces of treated mice using the aliquot technique. Control mice passaged oocysts at a geometric mean rate of \u3e104,000 oocysts/g feces. Control mice also produced significantly less feces on day 10. These results indicate that ponazuril is effective against E. vermiformis under the conditions utilized in this study, and that the E. vermiformis mouse model could be useful in predicting the efficacy of new anticoccidial drugs. © Springer-Verlag 2004

Divergent evolution of genetic sex determination mechanisms along environmental gradients

Sex determination (SD) is a crucial developmental process, but its molecular underpinnings are very diverse, both between and within species. SD mechanisms have traditionally been categorized as either genetic (GSD) or environmental (ESD), depending on the type of cue that triggers sexual differentiation. However, mixed systems, with both genetic and environmental components, are more prevalent than previously thought. Here, we show theoretically that environmental effects on expression levels of genes within SD regulatory mechanisms can easily trigger within-species evolutionary divergence of SD mechanisms. This may lead to the stable coexistence of multiple SD mechanisms and to spatial variation in the occurrence of different SD mechanisms along environmental gradients. We applied the model to the SD system of the housefly, a global species with world-wide latitudinal clines in the frequencies of different SD systems, and found that it correctly predicted these clines if specific genes in the housefly SD system were assumed to have temperature-dependent expression levels. We conclude that environmental sensitivity of gene regulatory networks may play an important role in diversification of SD mechanisms

Defect configurations and dynamical behavior in a Gay-Berne nematic emulsion

To model a nematic emulsion consisting of a surfactant-coated water droplet dispersed in a nematic host, we performed a molecular dynamics simulation of a droplet immersed in a system of 2048 Gay-Berne ellipsoids in a nematic phase. Strong radial anchoring at the surface of the droplet induced a Saturn ring defect configuration, consistent with theoretical predictions for very small droplets. A surface ring configuration was observed for lower radial anchoring strengths, and a pair of point defects was found near the poles of the droplet for tangential anchoring. We also simulated the falling ball experiment and measured the drag force anisotropy, in the presence of strong radial anchoring as well as zero anchoring strength.Comment: 17 pages, 15 figure