Transfer of MicroRNAs by Embryonic Stem Cell Microvesicles

Microvesicles are plasma membrane-derived vesicles released into the extracellular environment by a variety of cell types. Originally characterized from platelets, microvesicles are a normal constituent of human plasma, where they play an important role in maintaining hematostasis. Microvesicles have been shown to transfer proteins and RNA from cell to cell and they are also believed to play a role in intercellular communication. We characterized the RNA and protein content of embryonic stem cell microvesicles and show that they can be engineered to carry exogenously expressed mRNA and protein such as green fluorescent protein (GFP). We demonstrate that these engineered microvesicles dock and fuse with other embryonic stem cells, transferring their GFP. Additionally, we show that embryonic stem cells microvesicles contain abundant microRNA and that they can transfer a subset of microRNAs to mouse embryonic fibroblasts in vitro. Since microRNAs are short (21–24 nt), naturally occurring RNAs that regulate protein translation, our findings open up the intriguing possibility that stem cells can alter the expression of genes in neighboring cells by transferring microRNAs contained in microvesicles. Embryonic stem cell microvesicles may be useful therapeutic tools for transferring mRNA, microRNAs, protein, and siRNA to cells and may be important mediators of signaling within stem cell niches

MR imaging in sports-related glenohumeral instability

Sports-related shoulder pain and injuries represent a common problem. In this context, glenohumeral instability is currently believed to play a central role either as a recognized or as an unrecognized condition. Shoulder instabilities can roughly be divided into traumatic, atraumatic, and microtraumatic glenohumeral instabilities. In athletes, atraumatic and microtraumatic instabilities can lead to secondary impingement syndromes and chronic damage to intraarticular structures. Magnetic resonance (MR) arthrography is superior to conventional MR imaging in the diagnosis of labro-ligamentous injuries, intrinsic impingement, and SLAP (superior labral anteroposterior) lesions, and thus represents the most informative imaging modality in the overall assessment of glenohumeral instability. This article reviews the imaging criteria for the detection and classification of instability-related injuries in athletes with special emphasis on the influence of MR findings on therapeutic decisions

Study of Bc+B_c^+ decays to the K+K−π+K^+K^-\pi^+ final state and evidence for the decay Bc+→χc0π+B_c^+\to\chi_{c0}\pi^+

A study of $B_c^+\to K^+K^-\pi^+$ decays is performed for the first time using data corresponding to an integrated luminosity of 3.0 $\mathrm{fb}^{-1}$ collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies of $7$ and $8$ TeV. Evidence for the decay $B_c^+\to\chi_{c0}(\to K^+K^-)\pi^+$ is reported with a significance of 4.0 standard deviations, resulting in the measurement of $\frac{\sigma(B_c^+)}{\sigma(B^+)}\times\mathcal{B}(B_c^+\to\chi_{c0}\pi^+)$ to be $(9.8^{+3.4}_{-3.0}(\mathrm{stat})\pm 0.8(\mathrm{syst}))\times 10^{-6}$. Here $\mathcal{B}$ denotes a branching fraction while $\sigma(B_c^+)$ and $\sigma(B^+)$ are the production cross-sections for $B_c^+$ and $B^+$ mesons. An indication of $\bar b c$ weak annihilation is found for the region $m(K^-\pi^+)<1.834\mathrm{\,Ge\kern -0.1em V\!/}c^2$, with a significance of 2.4 standard deviations.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-022.html, link to supplemental material inserted in the reference

The Use of Flagella and Motility for Plant Colonization and Fitness by Different Strains of the Foodborne Pathogen Listeria monocytogenes

The role of flagella and motility in the attachment of the foodborne pathogen Listeria monocytogenes to various surfaces is mixed with some systems requiring flagella for an interaction and others needing only motility for cells to get to the surface. In nature this bacterium is a saprophyte and contaminated produce is an avenue for infection. Previous studies have documented the ability of this organism to attach to and colonize plant tissue. Motility mutants were generated in three wild type strains of L. monocytogenes by deleting either flaA, the gene encoding flagellin, or motAB, genes encoding part of the flagellar motor, and tested for both the ability to colonize sprouts and for the fitness of that colonization. The motAB mutants were not affected in the colonization of alfalfa, radish, and broccoli sprouts; however, some of the flaA mutants showed reduced colonization ability. The best colonizing wild type strain was reduced in colonization on all three sprout types as a result of a flaA deletion. A mutant in another background was only affected on alfalfa. The third, a poor alfalfa colonizer was not affected in colonization ability by any of the deletions. Fitness of colonization was measured in experiments of competition between mixtures of mutant and parent strains on sprouts. Here the flaA and motAB mutants of the three strain backgrounds were impaired in fitness of colonization of alfalfa and radish sprouts, and one strain background showed reduced fitness of both mutant types on broccoli sprouts. Together these data indicate a role for flagella for some strains to physically colonize some plants, while the fitness of that colonization is positively affected by motility in almost all cases

Pentoxifylline associated to hypertonic saline solution attenuates inflammatory process and apoptosis after intestinal ischemia/reperfusion in rats

PURPOSE:To evaluate intestinal inflammatory and apoptotic processes after intestinal ischemia/reperfusion injury, modulated by pentoxifylline and hypertonic saline.METHODS:It was allocated into four groups (n=6), 24 male Wistar rats (200 to 250g) and submitted to intestinal ischemia for 40 min and reperfusion for 80 min: IR (did not receive any treatment); HS group (Hypertonic Saline, 4ml/kg-IV); PTX group (Pentoxifylline, 30mg/kg-IV); HS+PTX group (Hypertonic Saline and Pentoxifylline). All animals were heparinized (100U/kg). At the end of reperfusion, ileal fragments were removed and stained on hematoxylin-eosin and histochemical studies for COX-2, Bcl-2 and cleaved caspase-3.RESULTS:The values of sO2 were higher on treated groups at 40 minutes of reperfusion (p=0.0081) and 80 minutes of reperfusion (p=0.0072). Serum lactate values were lower on treated groups after 40 minutes of reperfusion (p=0.0003) and 80 minutes of reperfusion (p=0.0098). Morphologic tissue injuries showed higher grades on IR group versus other groups: HS (p=0.0006), PTX (p=0.0433) and HS+PTX (p=0.0040). The histochemical study showed lesser expression of COX-2 (p=0.0015) and Bcl-2 (p=0.0012) on HS+PTX group. A lower expression of cleaved caspase-3 was demonstrated in PTX (p=0.0090; PTXvsIR).CONCLUSION:The combined use of pentoxifylline and hypertonic saline offers best results on inflammatory and apoptotic inhibitory aspects after intestinal ischemia/reperfusion.São Paulo University Medical SchoolUSP Medical SchoolFederal University of São Paulo Medical SchoolUSP School of MedicineUSP School of Medicine Department of SurgeryUSP Medical School Department of SurgeryUNIFESP, Medical SchoolSciEL

Understanding emotionally relevant situations in primary care dental practice: 1. Clinical situations and emotional responses

Background and aims. The stressful nature of dental practice is well established. Much less information is available on the coping strategies used by dentists and the emotions which underlie the stressful experience. Previous research has been almost exclusively questionnaire-based, limiting the range of emotions explored. This study used qualitative methods to explore the full extent of emotions and coping strategies associated with stressful events in primary dental practice. Method. Semi-structured interviews were conducted with 20 dentists in Lincoln and the surrounding area. Verbatim transcriptions were analysed using thematic analysis. Results. Participants reported a wide variety of stressful situations, consistent with the existing literature, which were associated with a diverse range of negative emotional responses including anxiety, anger and sadness. Dentists tended to have more difficulty identifying positive events and emotions. The designation of a situation as stressful or otherwise was dependent on the dentist's personal interpretation of the event. Data relating to the effects of stressors and the coping strategies used by dentists will be presented in subsequent papers. Conclusion. The situations which dentists find difficult are accompanied by a diverse set of emotions, rather than omnipresent 'stress.' This has implications for stress management programmes for those in dental practic

Predominant Functional Expression of Kv1.3 by Activated Microglia of the Hippocampus after Status epilepticus

BACKGROUND:Growing evidence indicates that the functional state of microglial cells differs according to the pathological conditions that trigger their activation. In particular, activated microglial cells can express sets of Kv subunits which sustain delayed rectifying potassium currents (Kdr) and modulate differently microglia proliferation and ability to release mediators. We recently reported that hippocampal microglia is in a particular activation state after a status epilepticus (SE) and the present study aimed at identifying which of the Kv channels are functionally expressed by microglia in this model. METHODOLOGY/PRINCIPAL FINDINGS:SE was induced by systemic injection of kainate in CX3CR1(eGFP/+) mice and whole cell recordings of fluorescent microglia were performed in acute hippocampal slices prepared 48 h after SE. Microglia expressed Kdr currents which were characterized by a potential of half-maximal activation near -25 mV, prominent steady-state and cumulative inactivations. Kdr currents were almost abolished by the broad spectrum antagonist 4-Aminopyridine (1 mM). In contrast, tetraethylammonium (TEA) at a concentration of 1 mM, known to block Kv3.1, Kv1.1 and 1.2 subunits, only weakly reduced Kdr currents. However, at a concentration of 5 mM which should also affect Kv1.3 and 1.6, TEA inhibited about 30% of the Kdr conductance. Alpha-dendrotoxin, which selectively inhibits Kv1.1, 1.2 and 1.6, reduced only weakly Kdr currents, indicating that channels formed by homomeric assemblies of these subunits are not important contributors of Kdr currents. Finally, agitoxin-2 and margatoxin strongly inhibited the current. CONCLUSIONS/SIGNIFICANCE:These results indicate that Kv1.3 containing channels predominantly determined Kdr currents in activated microglia after SE

Barriers to disseminating brief CBT for voices from a lived experience and clinician perspective

Access to psychological therapies continues to be poor for people experiencing psychosis. To address this problem, researchers are developing brief interventions that address the specific symptoms associated with psychosis, i.e., hearing voices. As part of the development work for a brief Cognitive Behaviour Therapy (CBT) intervention for voices we collected qualitative data from people who hear voices (study 1) and clinicians (study 2) on the potential barriers and facilitators to implementation and engagement. Thematic analysis of the responses from both groups revealed a number of anticipated barriers to implementation and engagement. Both groups believed the presenting problem (voices and psychosis symptoms) may impede engagement. Furthermore clinicians identified a lack of resources to be a barrier to implementation. The only facilitator to engagement was reported by people who hear voices who believed a compassionate, experienced and trustworthy therapist would promote engagement. The results are discussed in relation to how these barriers could be addressed in the context of a brief intervention using CBT techniques