Laser Speckle Imaging: A Novel Method for Detecting Dental Erosion

Erosion is a highly prevalent condition known as a non-carious lesion that causes progressive tooth wear due to chemical processes that do not involve the action of bacteria. Speckle images proved sensitive to even minimal mineral loss from the enamel. The aim of the present study was to investigate the use of laser speckle imaging analysis in the spatial domain to quantify shifts in the microstructure of the tooth surface in an erosion model. 32 fragments of the vestibular surface of bovine incisors were divided in for groups (10 min, 20 min. 30 min and 40 min of acid etching) immersed in a cola-based beverage (pH approximately 2.5) twice a day during 7 days to create an artificial erosion. By analyzing the laser speckle contrast map (LASCA) in the eroded region compared to the sound it was observed that the LASCA map shifts, proportionally to the acid each duration, by: 18%; 23%; 39% and 44% for the 10 min; 20 min; 30 min and 40 min groups, respectively. To the best of our knowledge, this is the first study to demonstrate the correlation between speckle patterns and erosion progression.     

On the role of attention in binocular rivalry: electrophysiological evidence

During binocular rivalry visual consciousness fluctuates between two dissimilar monocular images. We investigated the role of attention in this phenomenon by comparing event-related potentials (ERPs) when binocular-rivalry stimuli were attended with when they were unattended. Stimuli were dichoptic, orthogonal gratings that yielded binocular rivalry and dioptic, identically oriented gratings that yielded binocular fusion. Events were all possible orthogonal changes in orientation of one or both gratings. We had two attention conditions: In the attend-to-grating condition, participants had to report changes in perceived orientation, focussing their attention on the gratings. In the attend-to-fixation condition participants had to report changes in a central fixation target, taking attention away from the gratings. We found, surprisingly, that attending to rival gratings yielded a smaller ERP component (the N1, from 160-210 ms) than attending to the fixation target. To explain this paradoxical effect of attention, we propose that rivalry occurs in the attend-to-fixation condition (we found an ERP signature of rivalry in the form of a sustained negativity from 210-300 ms) but that the mechanism processing the stimulus changes is more adapted in the attend-to-grating condition than in the attend-to-fixation condition. This is consistent with the theory that adaptation gives rise to changes of visual consciousness during binocular rivalry.     

Differentiation of Lactobacillus sanfranciscensis strains by randomly amplified polymorphic DNA and pulsed-field gel electrophoresis

Genetic diversity of Lactobacillus sanfranciscensis strains isolated from naturally fermented sourdoughs of different origin was evaluated by using randomly amplified polymorphic DNA (RAPD). Computer-assisted comparison of the RAPD patterns revealed a clear separation of L. sanfranciscensis from other obligately heterofermentative Lactobacillus species closely related or normally present in sourdough. Six clusters, five of them constituted by strains of the same origin, were recognized at a similarity level of 63%. Pulsed-field gel electrophoresis (PFGE) results on strains chosen as representative were generally in good agreement with the grouping obtained by RAPD. Both techniques showed a high degree of discriminatory power and indicated the existence of a remarkable genetic polymorphism within the species. Furthermore, the chromosome size of L. sanfranciscensis was estimated by PFGE to be about 1.4 Mb.     

Preeclampsia: current understanding of the molecular basis of vascular dysfunction

Preeclampsia is a pregnancy-specific disorder characterised by hypertension and proteinuria occurring after the 20th week of gestation. Delivery of the placenta results in resolution of the condition, implicating the placenta as a central culprit in the pathogenesis of preeclampsia. In preeclampsia, an inadequate placental trophoblast invasion of the maternal uterine spiral arteries results in poor placental perfusion, leading to placental ischaemia. This could result in release of factors into the maternal circulation that cause widespread activation or dysfunction of the maternal endothelium. Factors in the maternal circulation might induce oxidative stress and/or elicit an inflammatory response in the maternal endothelium, resulting in the altered expression of several genes involved in the regulation of vascular tone. This review addresses the potential circulating factors and the molecular mechanisms involved in the alteration of vascular function that occurs in preeclampsia.     

SIV DNA vaccine co-administered with IL-12 expression plasmid enhances CD8 SIV cellular immune responses in cynomolgus macaques

Current evidence suggests that a strong induced CD8 human immunodeficiency virus type 1 (HIV-1)-specific cell mediated immune response may be an important aspect of an HIV vaccine. The response rates and the magnitude of the CTL responses induced by current DNA vaccines in humans need to be improved and cellular immune responses to DNA vaccines can be enhanced in mice by co-delivering DNA plasmids expressing immune modulators. Two reported to work well in the mouse systems are interleukin (IL)-12 and CD40L. We sought to compare these molecular adjuvants in a primate model system. The cDNA for macaque IL-12 and CD40L were cloned into DNA vectors. Groups of cynomolgus macaques were immunized with 2 mg of plasmid expressing SIVgag alone or in combination with either IL-12 or CD40L. CD40L did not appear to enhance the cellular immune response to SIVgag antigen. However, more robust results were observed in animals co-injected with the IL-12 molecular adjuvant. The IL-12 expanded antigen-specific IFN-gamma positive effector cells as well as granzyme B production. The vaccine immune responses contained both a CD8 component as well a CD4 component. The adjuvanted DNA vaccines illustrate that IL-12 enhances a CD8 vaccine immune response, however, different cellular profiles.     

Inhibitors of the serotonin transporter protein (SERT): the design and synthesis of biotinylated derivatives of 3-(1,2,3,6-tetrahydro-pyridin-4-yl)-1H-indoles. High-affinity serotonergic ligands for conjugation with quantum dots

There is a growing demand for compounds with specificity for the serotonin transporter protein (SERT) that can be conjugated to cadmium selenide/zinc sulfide core shell nanocrystals. This letter describes the design and synthesis of two different biotinylated SERT antagonists that can be attached to streptavidin-coated cadmium selenide/zinc sulfide core shell nanocrystals.