Genetic structure and variability of virus populations in cross-protected grapevines superinfected by Grapevine fanleaf virus

Recombination was assessed in a vineyard site in which grapevines cross-protected with mild strains GHu of Grapevine fanleaf virus (GFLV) or Ta of Arabis mosaic virus (ArMV) were superinfected with GFLV field isolates following transmission by the nematode vector Xiphinema index. The genetic structure and variability within RNA2 of isolates from grapevines co-infected with GFLV field isolates and either GFLV-GHu or ArMV-Ta were characterized to identify intra- and interspecies recombinants. Sequence analysis and phylogenetic relationships inferred intraspecies recombination among GFLV field isolates but not between field isolates and GFLV-GHu. SISCAN analysis confirmed a mosaic structure for two GFLV field isolates for which recombination sites were located in the movement protein and coat protein genes. One of the recombinants was found in eight grapevines that were in close spatial proximity within the vineyard site, suggesting its transmission by X. index. No interspecies recombination was detected between GFLV field isolates and ArMV-Ta. Altogether, our findings suggest that mild protective strains GFLV-GHu and ArMV-Ta did not assist the emergence of viable recombinants to detectable level during a 12-year cross-protection trial. To our knowledge, this is the first extensive characterization of the genetic structure and variability of virus isolates in cross-protected plants.     

Virtual Partner Interaction (VPI): Exploring Novel Behaviors via Coordination Dynamics

Inspired by the dynamic clamp of cellular neuroscience, this paper introduces VPI—Virtual Partner Interaction—a coupled dynamical system for studying real time interaction between a human and a machine. In this proof of concept study, human subjects coordinate hand movements with a virtual partner, an avatar of a hand whose movements are driven by a computerized version of the Haken-Kelso-Bunz (HKB) equations that have been shown to govern basic forms of human coordination. As a surrogate system for human social coordination, VPI allows one to examine regions of the parameter space not typically explored during live interactions. A number of novel behaviors never previously observed are uncovered and accounted for. Having its basis in an empirically derived theory of human coordination, VPI offers a principled approach to human-machine interaction and opens up new ways to understand how humans interact with human-like machines including identification of underlying neural mechanisms.     

Bacterial adhesion to conventional hydrogel and new silicone-hydrogel contact lens materials

Background As bacterial adhesion to contact lenses may contribute to the pathogenesis of keratitis, the aim of our study was to investigate in vitro adhesion of clinically relevant bacteria to conventional hydrogel (standard HEMA) and silicone-hydrogel contact lenses using a bioluminescent ATP assay. Methods Four types of unworn contact lenses (Etafilcon A, Galyfilcon A, Balafilcon A, Lotrafilcon B) were incubated with Staphylococcus epidermidis (two different strains) and Pseudomonas aeruginosa suspended in phosphate buffered saline (PBS). Lenses were placed with the posterior surface facing up and were incubated in the bacterial suspension for 4 hours at 37°C. Bacterial binding was then measured and studied by bioluminescent ATP assay. Six replicate experiments were performed for each lens and strain. Results Adhesion of all species of bacteria to standard HEMA contact lenses (Etafilcon A) was found to be significantly lower than that of three types of silicone-hydrogel contact lenses, whereas Lotrafilcon B material showed the highest level of bacterial binding. Differences between species in the overall level of adhesion to the different types of contact lenses were observed. Adhesion of P. aeruginosa was typically at least 20 times greater than that observed with both S. epidermidis strains. Conclusions Conventional hydrogel contact lenses exhibit significantly lower bacterial adhesion in vitro than silicone-hydrogel ones. This could be due to the greater hydrophobicity but also to the higher oxygen transmissibility of silicone–hydrogel lenses. A minor part of this work was presented at the 2006 CLAO Congress.     

Comedolysis by a lipohydroxyacid formulation in acne-prone subjects

Post-summertime exacerbation of acne is not a rare event. This study was conducted to assess the preventive effect of a proprietary formulation containing 2-hydroxy-5-octanoyl benzoic acid on this environmental related disease. This compound is commonly called beta-lipohydroxyacid (LHA). Among a randomized group of 14 acne-prone women, 12 who developed cornified follicular plugs the end of summertime were treated by the LHA formulation twice daily for 2 weeks. Ten of 14 other women who presented the same skin condition remained untreated as controls. The comedolytic effect was assessed using non-invasive ultraviolet-light video recording combined with computerized image analysis. The cornified follicular plugs were progressively cleared in 10/12 LHA-treated women and in 3/10 untreated volunteers. Analytical assessments showed a significant decrease in both the number and total size of microcomedones in the LHA-treated women. By contrast, no quantitative change was disclosed in the untreated group. It is concluded that the tested LHA formulation exerts comedolytic properties that might help in preventing post-summertime acne exacerbations.     

Comparison of the effects of racemic bupivacaine, levobupivacaine, and ropivacaine on ventricular conduction, refractoriness, and wavelength: an epicardial mapping study

BACKGROUND: The study was designed to compare the effects of equimolar concentrations of racemic bupivacaine, levobupivacaine, and ropivacaine on ventricular conduction, anisotropy, duration and homogeneity of refractoriness, and wavelengths, and to provide a potency ratio for effects on conduction velocity. METHODS: Isolated frozen rabbit hearts (which leave a thin layer of surviving epicardial muscle) were treated with 0.1, 1, and 10 mum racemic bupivacaine, levobupivacaine, or ropivacaine. Left ventricular longitudinal and transverse conduction velocities, anisotropic ratio, minimum pacing cycle length, use dependency, duration and dispersion of ventricular effective refractory period, and wavelengths were studied. A high-resolution mapping system was used for data acquisition. In addition to two-way analysis of variance for repeated measures, data for conduction velocities were fitted simultaneously using a nonlinear mixed-effect modeling program to allow intergroup comparison. RESULTS: Each agent induced a concentration- and use-dependent slowing of conduction velocities, with no change of the anisotropic ratio. The use-dependent effect of levobupivacaine is similar to that of racemic bupivacaine concerning longitudinal conduction velocity. Fitting of conduction velocities provided a racemic bupivacaine to levobupivacaine and to ropivacaine ratio of 1:1.38 for concentration effect at 1,000-ms pacing cycle length, and 1:0.74 for use-dependent effect at 600-ms pacing cycle length. Racemic bupivacaine and levobupivacaine prolonged the ventricular effective refractory period, whereas ropivacaine did not. No dispersion in ventricular effective refractory period values occurred. All three agents induced significant decreases in wavelengths. This effect was not different among groups. CONCLUSIONS: Differences among racemic bupivacaine, levobupivacaine, and ropivacaine at equimolar concentrations are mainly caused by the use-dependent effects on conduction velocities and the concentration-dependent effects on ventricular effective refractory period. Therefore, one must take into account the corresponding pacing rates when comparing the potency ratios of local anesthetics.     

Carcinogenesis and translational controls: TACC1 is down-regulated in human cancers and associates with mRNA regulators

The three human TACC genes encode a family of proteins that are suspected to play a role in carcinogenesis. Their function is not precisely known; a Xenopus TACC protein called Maskin is involved in translational control, while the Drosophila D-TACC associates with microtubules and centrosomes. We have characterized the human TACC1 gene and its products. The TACC1 gene is located in region p12 of chromosome 8; its mRNA is ubiquitously expressed and encodes a protein with an apparent molecular mass of 125 kDa, which is cytoplasmic and mainly perinuclear. We show that TACC1 mRNA gene expression is down-regulated in various types of tumors. Using immunohistochemistry of tumor tissue-microarrays and sections, we confirm that the level of TACC1 protein is down-regulated in breast cancer. Finally, using the two-hybrid screen in yeast, GST pull-downs and co-immunoprecipitations, we identified two potential binding partners for TACC1, LSM7 and SmG. They constitute a conserved subfamily of Sm-like small proteins that associate with U6 snRNPs and play a role in several aspects of mRNA processing. We speculate that down-regulation of TACC1 may alter the control of mRNA homeostasis in polarized cells and participates in the oncogenic processes.     

De la tautologie psychotique

This study centres on the question of psychotic tautologies as found in cases of morbid rationalism and morbid geometrism (Minkowski). The study concentrates on the writings of a psychotic psychiatrist, François Klein M.D., his work is an orgy of identifications based, to a high degree, on the logic of identity ; this is seen as an opening towards a clearer understanding of the structure that produces true psychosis. The authors argue that the tautology is a kind of « meeting point » a « launch-pad » that introduces unwarranted extrapolation. In other words the tautology as an extreme of morbid rationalism opens towards a paraphrenic reconstruction. This of course is in harmony with Freud’s thinking.     

Need for closure and jumping-to-conclusions in delusion-prone individuals

Members of the general population were screened for delusion-proneness using the Peters et al. Delusions Inventory (PDI). Two groups were formed from the participants who scored in the upper and lower quartiles of the PDI and compared on a probability judgment task and on the Need for Closure scale (NFC). The study investigated whether the "jump-to-conclusions" (JTC) reasoning bias, characteristic of deluded participants, could be found in delusion-prone individuals. NFC was investigated as a motivational factor that may correlate with this reasoning bias. Evidence for the existence of the data-gathering, but not the probability judgment, part of the JTC reasoning bias was found in the delusion-prone individuals. This group also scored significantly higher on the NFC scale. As the data-gathering reasoning bias was found in delusion-prone individuals this suggests that it may be involved in the formation, rather than merely the maintenance, of delusional beliefs.