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Kost RG, Lee LN, Yessis JL, Wesley R, Alfano S, Alexander SR, Kassis SB, Cola P, Dozier A, Ford DE, Harris PA, Kim E, Lee SC, O'Riordan G, Roth MT, Schuff K, Wasser J, Henderson DK, Coller BS
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Research Participant-Centered Outcomes at NIH-Supported Clinical Research Centers

CTS-CLINICAL AND TRANSLATIONAL SCIENCE 2014 DEC; 7(6):430-440
BackgroundAlthough research participation is essential for clinical investigation, few quantitative outcome measures exist to assess participants' experiences. To address this, we developed and deployed a survey at 15 NIH-supported clinical research centers to assess participant-centered outcomes; we report responses from 4,961 participants. MethodsSurvey questions addressed core aspects of the research participants' experience, including their overall rating, motivation, trust, and informed consent. We describe participant characteristics, responses to individual questions, and correlations among responses. ResultsRespondents broadly represented the research population in sex, race, and ethnicity. Seventy-three percent awarded top ratings to their overall research experience and 94% reported no pressure to enroll. Top ratings correlated with feeling treated with respect, listened to, and having access to the research team (R-2 = 0.80-0.96). White participants trusted researchers more (88%) than did nonwhite participants collectively (80%; p < 0.0001). Many participants felt fully prepared by the informed consent process (67%) and wanted to receive research results (72%). ConclusionsOur survey demonstrates that a majority of participants at NIH-supported clinical research centers rate their research experience very positively and that participant-centered outcome measures identify actionable items for improvement of participant's experiences, research protections, and the conduct of clinical investigation.
Forgacs PB, Conte MM, Fridman EA, Voss HU, Victor JD, Schiff ND
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Preservation of Electroencephalographic Organization in Patients with Impaired Consciousness and Imaging-Based Evidence of Command-Following

ANNALS OF NEUROLOGY 2014 DEC; 76(6):869-879
ObjectiveStandard clinical characterization of patients with disorders of consciousness (DOC) relies on observation of motor output and may therefore lead to the misdiagnosis of vegetative state or minimally conscious state in patients with preserved cognition. We used conventional electroencephalographic (EEG) measures to assess a cohort of DOC patients with and without functional magnetic resonance imaging (fMRI)-based evidence of command-following, and correlated the findings with standard clinical behavioral evaluation and brain metabolic activity. MethodsWe enrolled 44 patients with severe brain injury. Behavioral diagnosis was established using standardized clinical assessments. Long-term EEG recordings were analyzed to determine wakeful background organization and presence of elements of sleep architecture. A subset of patients had fMRI testing of command-following using motor imagery paradigms (26 patients) and resting brain metabolism measurement using (18)fluorodeoxyglucose positron emission tomography (31 patients). ResultsAll 4 patients with fMRI evidence of covert command-following consistently demonstrated well-organized EEG background during wakefulness, spindling activity during sleep, and relative preservation of cortical metabolic activity. In the entire cohort, EEG organization and overall brain metabolism showed no significant association with bedside behavioral testing, except in a few cases when EEG was severely abnormal. InterpretationThese findings suggest that conventional EEG is a simple strategy that complements behavioral and imaging characterization of DOC patients. Preservation of specific EEG features may be used to assess the likelihood of unrecognized cognitive abilities in severely brain-injured patients with very limited or no motor responses. Ann Neurol 2014;76:869-879
Wetzel-Smith MK, Hunkapiller J, Bhangale TR, Srinivasan K, Maloney JA, Atwal JK, Sa SM, Yaylaoglu MB, Foreman O, Ortmann W, Rathore N, Hansen DV, Tessier-Lavigne M, Mayeux R, Pericak-Vance M, Haines J, Farrer LA, Schellenberg GD, Goate A, Behrens TW, Cruchaga C, Watts RJ, Graham RR
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A rare mutation in UNC5C predisposes to late-onset Alzheimer's disease and increases neuronal cell death

NATURE MEDICINE 2014 DEC; 20(12):1452-1457
We have identified a rare coding mutation, T835M (rs137875858), in the UNC5C netrin receptor gene that segregated with disease in an autosomal dominant pattern in two families enriched for late-onset Alzheimer's disease and that was associated with disease across four large case-control cohorts (odds ratio = 2.15, P-meta = 0.0095). T835M alters a conserved residue in the hinge region of UNC5C, and in vitro studies demonstrate that this mutation leads to increased cell death in human HEK293T cells and in rodent neurons. Furthermore, neurons expressing T835M UNC5C are more susceptible to cell death from multiple neurotoxic stimuli, including p-amyloid (A beta), glutamate and staurosporine. On the basis of these data and the enriched hippocampal expression of UNC5C in the adult nervous system, we propose that one possible mechanism in which T835M UNC5C contributes to the risk of Alzheimer's disease is by increasing susceptibility to neuronal cell death, particularly in vulnerable regions of the Alzheimer's disease brain.
Brohawn SG, Campbell EB, MacKinnon R
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Physical mechanism for gating and mechano sensitivity of the human TRAAK K+ channel

NATURE 2014 DEC 4; 516(7529):126-U345
Activation of mechanosensitive ion channels by physical force underlies many physiological processes including the sensation of touch, hearing and pain(1-5). TRAAK (also known as KCNK4) ion channels are neuronally expressed members of the two-pore domain K+ (K2P) channel family and are mechano sensitive'. They are involved in controlling mechanical and temperature nociception in mice'. Mechanosensitivity of TRAAK is mediated directly through the lipid bilayer it is a membrane-tension-gated channel'. However, the molecular mechanism of TRAAK channel gating and mechanosensitivity is unknown. Here we present crystal structures of TRAAK in conductive and non-conductive conformations defined by the presence of permeant ions along the conduction pathway. In the non-conductive state, a lipid acyl chain accesses the channel cavity through a 5 Awide lateral opening in the membrane inner leaflet and physically blocks ion passage. In the conductive state, rotation of a transmembrane helix (TM4) about a central hinge seals the intramembrane opening, preventing lipid block of the cavity and permitting ion entry. Additional rotation of a membrane interacting TM2-TM 3 segment, unique to mechanosensitive K2Ps, against TM4 may further stabilize the conductive conformation. Comparison of the structures reveals a biophysical explanation for TRAAK mechanosensitivity an expansion in cross-sectional area up to 2.7 nm(2) in the conductive state is expected to create a membrane-tension-dependent energy difference between conformations that promotes force activation. Our results show how tension of the lipid bilayer can be harnessed to control gating and mechanosensitivity of a eukaryotic ion channel.
Sagi Y, Heiman M, Peterson JD, Musatov S, Kaplitt MG, Surmeier DJ, Heintz N, Greengard P
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Nitric oxide regulates synaptic transmission between spiny projection neurons

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2014 DEC 9; 111(49):17636-17641
Recurrent axon collaterals are a major means of communication between spiny projection neurons (SPNs) in the striatum and profoundly affect the function of the basal ganglia. However, little is known about the molecular and cellular mechanisms that underlie this communication. We show that intrastriatal nitric oxide (NO) signaling elevates the expression of the vesicular GABA transporter (VGAT) within recurrent collaterals of SPNs. Down-regulation of striatal NO signaling resulted in an attenuation of GABAergic signaling in SPN local collaterals, down-regulation of VGAT expression in local processes of SPNs, and impaired motor behavior. PKG1 and cAMP response element-binding protein are involved in the signal transduction that transcriptionally regulates VGAT by NO. These data suggest that transcriptional control of the vesicular GABA transporter by NO regulates GABA transmission and action selection.
Dervaux J, Magniez JC, Libchaber A
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On growth and form of Bacillus subtilis biofilms

INTERFACE FOCUS 2014 DEC 6; 4(6):? Article 20130051
A general feature of mature biofilms is their highly heterogeneous architecture that partitions the microbial city into sectors with specific micro-environments. To understand how this heterogeneity arises, we have investigated the formation of a microbial community of the model organism Bacillus subtilis. We first show that the growth of macroscopic colonies is inhibited by the accumulation of ammoniacal by-products. By constraining biofilms to grow approximately as two-dimensional layers, we then find that the bacteria which differentiate to produce extracellular polymeric substances formtightly packed bacterial chains. In addition to the process of cellular chaining, the biomass stickiness also strongly hinders the reorganization of cells within the biofilm. Based on these observations, we then write a biomechanical model for the growth of the biofilm where the cell density is constant and the physical mechanism responsible for the spreading of the biomass is the pressure generated by the division of the bacteria. Besides reproducing the velocity field of the biomass across the biofilm, the model predicts that, although bacteria divide everywhere in the biofilm, fluctuations in the growth rates of the bacteria lead to a coarsening of the growing bacterial layer. This process of kinetic roughening ultimately leads to the formation of a rough biofilm surface exhibiting self-similar properties. Experimental measurements of the biofilm texture confirm these predictions.
Dunne A, Maple-Grodem J, Gargano D, Haslam RP, Napier JA, Chua NH, Russell R, Moller SG
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Modifying fatty acid profiles through a new cytokinin-based plastid transformation system

PLANT JOURNAL 2014 DEC; 80(6):1131-1138
The widespread use of herbicides and antibiotics for selection of transgenic plants has not been very successful with regard to commercialization and public acceptance. Hence, alternative selection systems are required. In this study, we describe the use of ipt, the bacterial gene encoding the enzyme isopentenyl transferase from Agrobacterium tumefaciens, as a positive selectable marker for plastid transformation. A comparison between the traditional spectinomycin-based aadA selection system and the ipt selection system demonstrated that selection of transplastomic plants on medium lacking cytokinin was as effective as selection on medium containing spectinomycin. Proof of principle was demonstrated by transformation of the kasIII gene encoding 3-ketoacyl acyl carrier protein synthaseIII into tobacco plastids. Transplastomic tobacco plants were readily obtained using the ipt selection system, and were phenotypically normal despite over-expression of isopentenyl transferase. Over-expression of KASIII resulted in a significant increase in 16:0 fatty acid levels, and a significant decrease in the levels of 18:0 and 18:1 fatty acids. Our study demonstrates use of a novel positive plastid transformation system that may be used for selection of transplastomic plants without affecting the expression of transgenes within the integrated vector cassette or the resulting activity of the encoded protein. This system has the potential to be applied to monocots, which are typically not amenable to traditional antibiotic-based selection systems, and may be used in combination with a negative selectable marker as part of a two-step selection system to obtain homoplasmic plant lines.
Frank MO, Kaufman J, Parveen S, Blachere NE, Orange DE, Darnell RB
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Dendritic cell vaccines containing lymphocytes produce improved immunogenicity in patients with cancer

JOURNAL OF TRANSLATIONAL MEDICINE 2014 DEC 5; 12(?):? Article 338
Background: Dendritic cells are currently under investigation for their ability to generate anti-cancer immune responses. No consensus has been reached as to the optimal method of dendritic cell vaccine preparation and is a barrier to success in the field. Methods: Over a course of three separate dendritic cell vaccine studies to treat cancer, we tested two different methods for preparing dendritic cells from peripheral blood mononuclear cells: adherence and antibody-selected CD14+ cells. Results: Surprisingly, we found that patients who received dendritic cell vaccines generated by the adherence method mounted increased T cell proliferation in response to vaccination. This difference could not be accounted for by dendritic cell vaccine dose, cell surface phenotype or dendritic cell function in vitro. One notable difference between the two vaccine preparation methods was that the dendritic cell vaccine cultures generated by the adherence method contained up to 10% lymphocytes, and these lymphocytes were proliferating and producing IFN gamma in response to antigen in vitro at the time of administration. Conclusions: Enhanced immunogenicity of adherence dendritic cell vaccinations may be due to the presence of lymphocytes during dendritic cell culture.
Sato M, Dehvari N, Oberg AI, Dallner OS, Sandstrom AL, Olsen JM, Csikasz RI, Summers RJ, Hutchinson DS, Bengtsson T
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Improving Type 2 Diabetes Through a Distinct Adrenergic Signaling Pathway Involving mTORC2 That Mediates Glucose Uptake in Skeletal Muscle

DIABETES 2014 DEC; 63(12):4115-4129
There is an increasing worldwide epidemic of type 2 diabetes that poses major health problems. We have identified a novel physiological system that increases glucose uptake in skeletal muscle but not in white adipocytes. Activation of this system improves glucose tolerance in Goto-Kakizaki rats or mice fed a high-fat diet, which are established models for type 2 diabetes. The pathway involves activation of beta(2)-adrenoceptors that increase cAMP levels and activate cAMP-dependent protein kinase, which phosphorylates mammalian target of rapamycin complex 2 (mTORC2) at S2481. The active mTORC2 causes translocation of GLUT4 to the plasma membrane and glucose uptake without the involvement of Akt or AS160. Stimulation of glucose uptake into skeletal muscle after activation of the sympathetic nervous system is likely to be of high physiological relevance because mTORC2 activation was observed at the cellular, tissue, and whole-animal level in rodent and human systems. This signaling pathway provides new opportunities for the treatment of type 2 diabetes.
Calis JJA, Rosenberg BR
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Characterizing immune repertoires by high throughput sequencing: strategies and applications

TRENDS IN IMMUNOLOGY 2014 DEC; 35(12):581-590
As the key cellular effectors of adaptive immunity, T and B lymphocytes utilize specialized receptors to recognize, respond to, and neutralize a diverse array of extrinsic threats. These receptors (immunoglobulins in B lymphocytes, T cell receptors in T lymphocytes) are incredibly variable, the products of specialized genetic diversification mechanisms that generate complex lymphocyte repertoires with extensive collections of antigen specificities. Recent advances in high throughput sequencing (HTS) technologies have transformed our ability to examine antigen receptor repertoires at single nucleotide, and more recently, single cell, resolution. Here we review current approaches to examining antigen receptor repertoires by HIS, and discuss inherent biological and technical challenges. We further describe emerging applications of this powerful methodology for exploring the adaptive immune system.