1,138 research outputs found

    Antigenic modulation of mammary tumour virus envelope antigen or GR thymic lymphoma cells in relation to expressions of H-2, TL cell-surface antigens and THY1.

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    The MLr antigen, a mammary tumour virus-induced antigen on the surface of GR thymic lymphoma cells (GRSL) can be modulated from the cell surface upon incubation with specific antiserum for 1-2 h at 37 degrees C, followed by washing the cells. In contrast, a number of other cell-surface antigens on these GRSL cells cannot be modulated under similar conditions. These antigens include histocompatibility antigens of the H-2 complex (H-2.8 of the K-end and H-2dx(D) of the H-2dx haplotype) and two thymic markers, TL1.2 and Thy1.2. Antigenic modulation of MLr as tested by trypan-blue exclusion and by chromium51 release does not lead to a measurable change in the expression of H-2K, H-2D, TL and Thy1.2 antigens. These results could be confirmed by absorption analysis. The latter analysis showed that the number of antigenic sites per cell are about the same for MLr and the two H-2 antigens, while TL antigens are scarcer and Thy1.2 antigens are more abundant. The procedure of antigenic modulation showed that the MLr antigen resides on MTVgp52, the major protein of the envelope. There was no evidence of internal proteins, such as MTVp27, on the surface of GRSL cells

    Endotracheal temperature and humidity measurements in laryngectomized patients: intra- and inter-patient variability

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    This study assesses intra- and inter-patient variability in endotracheal climate (temperature and humidity) and effects of heat and moister exchangers (HME) in 16 laryngectomized individuals, measured repeatedly (N = 47). Inhalation Breath Length (IBL) was 1.35 s without HME and 1.05 s with HME (P < 0.0001). With HME, end-inspiratory (minimum) humidity values increased 5.8 mg H2O/L (P < 0.0001) and minimum temperature values decreased 1.6°C (P < 0.0001). For the temperature and humidity minimums, the inter-patient variability was much smaller than the short- and long-term intra-patient variability. For exhalation breath length and full breath length, the opposite was the case. Conclusions: (1) Because inter-patient variability is smaller than intra-patient variability, investigating endotracheal climate in a limited number of laryngectomized subjects is justified, provided repeated measurements per patient are accomplished; (2) main contributor to intra-patient variability is the positioning of the catheter tip in the trachea; (3) an HME leads to a shortened IBL which enhances the HME effect

    A Randomized Preventive Rehabilitation Trial in Advanced Head and Neck Cancer Patients Treated with Chemoradiotherapy: Feasibility, Compliance, and Short-term Effects

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    The aim of this study was to assess the effect of (preventive) rehabilitation on swallowing and mouth opening after concomitant chemoradiotherapy (CCRT). Forty-nine patients with advanced oral cavity, oropharynx, hypopharynx and larynx, or nasopharynx cancer treated with CCRT were randomized into a standard (S) or an experimental (E) preventive rehabilitation arm. Structured multidimensional assessment (i.e., videofluoroscopy, mouth-opening measurement, structured questionnaires) was performed before and 10 weeks after CCRT. In both S and E arms, feasibility was good (all patients could execute the exercises within a week) and compliance was satisfactory (mean days practiced per week was 4). Nevertheless, mouth opening, oral intake, and weight decreased significantly. Compared to similar CCRT studies at our institute, however, fewer patients were still tube-dependent after CCRT. Furthermore, some functional outcomes seemed less affected than those of studies in the literature that did not incorporate rehabilitation exercises. Patients in the E arm practiced significantly fewer days in total and per week, but they obtained results comparable to the S arm patients. Preventive rehabilitation (regardless of the approach, i.e., experimental or standard) in head and neck cancer patients, despite advanced stage and burdensome treatment, is feasible, and compared with historical controls, it seems helpful in reducing the extent and/or severity of various functional short-term effects of CCRT

    The long noncoding RNA mimi scaffolds neuronal granules to maintain nervous system maturity

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    RNA binding proteins and messenger RNAs (mRNAs) assemble into ribonucleoprotein granules that regulate mRNA trafficking, local translation, and turnover. The dysregulation of RNA-protein condensation disturbs synaptic plas-ticity and neuron survival and has been widely associated with human neurological disease. Neuronal granules are thought to condense around particular proteins that dictate the identity and composition of each granule type. Here, we show in Drosophila that a previously uncharacterized long noncoding RNA, mimi, is required to scaffold large neuronal granules in the adult nervous system. Neuronal ELAV-like proteins directly bind mimi and mediate granule assembly, while Staufen maintains condensate integrity. mimi granules contain mRNAs and proteins involved in synaptic processes; granule loss in mimi mutant flies impairs nervous system maturity and neuropeptide-mediated signaling and causes phenotypes of neurodegeneration. Our work reports an architectural RNA for a neuronal granule and provides a handle to interrogate functions of a condensate independently of those of its constituent proteins

    Molecular cloning of KS, a novel rat gene expressed exclusively in the kidney

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    Molecular cloning of xKSx, a novel rat gene expressed exclusively in the kidney.BackgroundWe aimed to identify genes with kidney specific, developmentally regulated expression. Here we report the cDNA sequence and expression pattern of KS, a novel kidney-specific rat gene.MethodsA partial cDNA was identified by differential display polymerase chain reaction (PCR) of a renal cell fraction enriched for proximal tubular and renin-expressing cells. Using the partial cDNA as a probe, a rat kidney cDNA library was screened. The full-length KS sequence was obtained by PCR amplification of cDNA ends. The expression pattern of KS was investigated by Northern blot. RNA was extracted from several organs of newborn and adult rats, as well as from the kidneys of rats with altered tubular function, that is, rats that had undergone unilateral nephrectomy, unilateral ureteral obstruction, neonatal losartan treatment, and the appropriate control animals. The expression of KS was also investigated in the kidneys of rats with spontaneous or renovascular hypertension.ResultsThe KS cDNA (2426bp) contained one open reading frame encoding a predicted 572 amino acid protein. The derived peptide sequence displayed approximately 70% similarity to the hypertension-related SA gene product and approximately 50% similarity to prokaryotic and eukaryotic acetyl-CoA synthases (EC 6.2.1.1). KS was expressed in the kidney and not in any other organ assayed. KS RNA was not detected in fetal and newborn rat kidney but became apparent after one week of postnatal life. Gene expression was downregulated in rat models of altered tubular function. KS expression was decreased in spontaneously hypertensive rats but not in renovascular hypertension.ConclusionKS, a novel rat gene, exhibits a unique tissue-specific expression exclusively in mature kidneys. The data suggest KS may encode an adenosine monophosphate binding enzyme

    Properties of Saturn Kilometric Radiation measured within its source region

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    On 17 October 2008, the Cassini spacecraft crossed the southern sources of Saturn kilometric radiation (SKR), while flying along high-latitude nightside magnetic field lines. In situ measurements allowed us to characterize for the first time the source region of an extra-terrestrial auroral radio emission. Using radio, magnetic field and particle observations, we show that SKR sources are surrounded by a hot tenuous plasma, in a region of upward field-aligned currents. Magnetic field lines supporting radio sources map a continuous, high-latitude and spiral-shaped auroral oval observed on the dawnside, consistent with enhanced auroral activity. Investigating the Cyclotron Maser Instability (CMI) as a mechanism responsible for SKR generation, we find that observed cutoff frequencies are consistent with radio waves amplified perpendicular to the magnetic field by hot (6 to 9 keV) resonant electrons, measured locally

    Extension of SPIS to simulate dust electrostatic charging, transport and contamination of lunar probes

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    A modification of the Spacecraft Plasma Interaction Software has been undertaken under ESA contract 4000107327/12/NL/AK (SPIS-DUST). The primary goal is to provide mission designers with an engineering tool capable of predicting charged dust behavior in a given plasma environment involving a spacecraft / exploration unit in contact with complex topological features at various locations of the Moon’s surface. The tool also aims at facilitating dust contamination diagnostics for sensitive surfaces such as sensors optics, solar panels, thermal interfaces, etc. In this paper, the new user interface and the new numerical solvers developed in the frame of this project is presented. The pre-processing includes the building of a 3D lunar surface from a topology description (i.e. a point list), an interface to position the spacecraft and a merging interface for the spacecraft elements in contact with the lunar surface. Concerning the physical models, the new solvers have been developed in order to model the physics of the ejection of the dust from the soils, the dusts charging and transport in volume and the dust interaction and contamination of the spacecraft. The post-processing includes the standard outputs of SPIS for the electrostatic computation and the plasma plus dedicated instruments for the diagnosis of the dusts. A set of verification test cases are presented in order to demonstrate the new capabilities of this version of SPIS in realistic conditions

    Chaotic scalar fields as models for dark energy

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    We consider stochastically quantized self-interacting scalar fields as suitable models to generate dark energy in the universe. Second quantization effects lead to new and unexpected phenomena is the self interaction strength is strong. The stochastically quantized dynamics can degenerate to a chaotic dynamics conjugated to a Bernoulli shift in fictitious time, and the right amount of vacuum energy density can be generated without fine tuning. It is numerically observed that the scalar field dynamics distinguishes fundamental parameters such as the electroweak and strong coupling constants as corresponding to local minima in the dark energy landscape. Chaotic fields can offer possible solutions to the cosmological coincidence problem, as well as to the problem of uniqueness of vacua.Comment: 30 pages, 3 figures. Replaced by final version accepted by Phys. Rev.
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