HIV and Mature Dendritic Cells: Trojan Exosomes Riding the Trojan Horse?

Exosomes are secreted cellular vesicles that can induce specific CD4+ T cell responses in vivo when they interact with competent antigen-presenting cells like mature dendritic cells (mDCs). The Trojan exosome hypothesis proposes that retroviruses can take advantage of the cell-encoded intercellular vesicle traffic and exosome exchange pathway, moving between cells in the absence of fusion events in search of adequate target cells. Here, we discuss recent data supporting this hypothesis, which further explains how DCs can capture and internalize retroviruses like HIV-1 in the absence of fusion events, leading to the productive infection of interacting CD4+ T cells and contributing to viral spread through a mechanism known as trans-infection. We suggest that HIV-1 can exploit an exosome antigen-dissemination pathway intrinsic to mDCs, allowing viral internalization and final trans-infection of CD4+ T cells. In contrast to previous reports that focus on the ability of immature DCs to capture HIV in the mucosa, this review emphasizes the outstanding role that mature DCs could have promoting trans-infection in the lymph node, underscoring a new potential viral dissemination pathway

Erosive cola-based drinks affect the bonding to enamel surface: an in vitro study

Objective: This study aimed to assess the impact of in vitro erosion provoked by different cola-based drinks (Coke types), associated or not with toothbrushing, to bonding to enamel. Material and methods: Forty-six bovine enamel specimens were prepared and randomly assigned into seven groups (N=8): C- Control (neither eroded nor abraded), ERO-RC: 3x/1-minute immersion in Regular Coke (RC), ERO-LC: 3x/1-minute immersion in Light Coke (LC), ERO-ZC: 3x/1-minute immersion in Zero Coke (ZC) and three other eroded groups, subsequently abraded for 1-minute toothbrushing (EROAB-RC, EROAB-LC and EROAB-ZC, respectively). After challenges, they were stored overnight in artificial saliva for a total of 24 hours and restored with Adper Single Bond 2/Filtek Z350. Buildup coronal surfaces were cut in 1 mm2 -specimens and subjected to a microtensile test. Data were statistically analyzed by two-way ANOVA/Bonferroni tests (α=0.05). Failure modes were assessed by optical microscopy (X40). The Interface of the restorations were observed using Confocal Laser Scanning Microscopy (CLSM). Results: All tested cola-based drinks significantly reduced the bond strength, which was also observed in the analyses of interfaces. Toothbrushing did not have any impact on the bond strength. CLSM showed that except for Zero Coke, all eroded specimens resulted in irregular hybrid layer formation. Conclusions: All cola-based drinks reduced the bond strength. Different patterns of hybrid layers were obtained revealing their impact, except for ZC

Search for the lepton flavour violating decay τ − → μ − μ + μ −

A search for the lepton flavour violating decay $\tau^-\to \mu^-\mu^+\mu^-$ is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of $1.0\mathrm{\,fb}^{-1}$ of proton-proton collisions at a centre-of-mass energy of $7\mathrm{\,Te\kern -0.1em V}$ and $2.0\mathrm{\,fb}^{-1}$ at $8\mathrm{\,Te\kern -0.1em V}$. No evidence is found for a signal, and a limit is set at $90\%$ confidence level on the branching fraction, $\mathcal{B}(\tau^-\to \mu^-\mu^+\mu^-) < 4.6 \times 10^{-8}$.Comment: 20 pages, 10 figures, published as JHEP 02 (2015) 12

Amphetamine-induced taste aversion learning in young and old F-344 rats following exposure to 56Fe particles

Exposure to 56Fe particles produces changes in dopaminergic function and in dopamine-dependent behaviors, including amphetamine-induced conditioned taste aversion (CTA) learning. Because many of these changes are characteristic of the changes that accompany the aging process, the present study was designed to determine whether or not there would be an interaction between age and exposure to 56Fe particles in the disruption of an amphetamine-induced CTA. One hundred and forty F-344 male rats 2-, 7-, 12-, and 16-months old, were radiated with 56Fe particles (0.25–2.00 Gy, 1 GeV/n) at Brookhaven National Laboratory. Three days following irradiation, the rats were tested for the effects of radiation on the acquisition of a CTA produced by injection of amphetamine (3 mg/kg, i.p.). The main effect of age was to produce a significant decrease in conditioning day sucrose intake; there was no affect of age on the acquisition of the amphetamine-induced CTA. Exposing rats to 56Fe particles disrupted the acquisition of the CTA produced by injection of amphetamine only in the 2-month-old rats. These results do not support the hypothesis of an interaction between age and exposure to 56Fe particles in producing a disruption of amphetamine-induced CTA learning. As such, these results suggest that the aging produced by exposure to 56Fe particles may be endpoint specific

The effect of homogenisation and storage on the near-infrared spectra of half shell Pacific Oysters (Crassostrea gigas)

The effect of sample homogenisation and storage on the near-infrared spectra of Pacific Oysters (Crassostrea gigas) has been assessed. On each day of storage (Days 0, 3 and 5), spectra were collected using a Fourier transform near-infrared reflectance spectrometer in reflectance mode between 833 and 2,630 nm from whole (n = 20) and homogenised oysters (n = 20). The raw spectra were dominated by water- and fatty-acid-associated bands. Linear regression analysis of the water-associated absorbance bands occurring at 1,942 nm indicated that a physical or chemical interaction may be taking place within the oysters at or near Day 3, likely associated with transfer of liquids to and from oyster tissues. One-way analysis of variance of principal component scores and extended multiplicative scatter correction highlighted the water regions (O-H bonds) in whole oysters and the importance of N-H-related compounds in homogenised oysters throughout storage. These findings indicate the potential usefulness of near-infrared reflectance spectroscopy to monitor and evaluate degradation of oysters over time. © 2011 Springer Science+Business Media, LLC.Thomas Madigan, Andreas Kiermeier, Miguel de Barros Lopes, Daniel Cozzolin