266 research outputs found

    Open 6to4 Relay Router Operation

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    Role of adenosine in the renal responses to contrast medium

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    Role of adenosine in the renal responses to contrast medium. Despite the development of non-ionic radiographic contrast media (CM), CM-induced nephropathy is a clinically important problem in patients with pre-existing renal insufficiency. We examined the effects of non-ionic CM (iohexol) on renal function in conscious dogs with and without renal insufficiency, and evaluated the effects of a non-selective (theophylline), an A1 selective (KW-3902), and an A2 selective adenosine antagonist (KF17837) on the renal responses to CM. In sham-operated group, iohexol (2ml/kg/min for 3min) increased effective renal plasma flow (ERPF) and glomerular filtration rate (GFR), whereas in renal insufficiency group (with subtotal nephrectomy), following transient increases in ERPF and GFR, CM markedly decreased ERPF (-46.5 Ā± 6.7%) and GFR (-51.2 Ā± 7.1%). In sham-operated group, theophylline and KF17837 markedly attenuated CM-induced increases in ERPF and GFR, while KW-3902 had no effects on CM-induced increases in ERPF or GFR. In renal insufficiency group, initial increases in ERPF and GFR were blunted by theophylline and KF17837. In contrast, the subsequent decreases in ERPF and GFR were attenuated by theophylline (%Ī”ERPF, -12.2 Ā± 3.2% vs. -46.6 Ā± 6.7%, P < 0.01; %Ī”GFR, 4.3 Ā± 2.5% vs. -51.0 Ā± 7.1%, P < 0.01), and were completely prevented by KW-3902 (%Ī”ERPF, 10.8 Ā± 2.9%; %Ī”GFR, 23.8 Ā± 4.4%), whereas KF17837 aggravated ERPF (-73.3 Ā± 5.3%) and GFR (-78.4 Ā± 5.3%). These data indicate that in normal renal function, iohexol elicits renal vasodilation by activating mainly the adenosine A2 receptors. In contrast, in impaired renal function, CM induces both A2 and A1 activation; the former is associated with the initial renal vasodilation, while the latter is responsible for the sustained aggravation of renal hemodynamics

    Crystallization strategy for the glycoprotein-receptor complex between measles virus hemagglutinin and its cellular receptor SLAM.

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    Measles virus (MV), one of the most contagious agents, infects immune cells using the signaling lymphocyte activation molecule (SLAM) on the cell surface. A complex of SLAM and the attachment protein, hemagglutinin (MVH), has remained elusive due to the intrinsic handling difficulty including glycosylation. Furthermore, crystals obtained of this complex are either nondiffracting or poorly-diffracting. To solve this problem, we designed a systematic approach using a combination of the following techniques; (1) a transient expression system in HEK293SGnTI(-) cells, (2) lysine methylation, (3) structure-guided mutagenesis directed at better crystal packing, (4) Endo H treatment, (5) single-chain formation for stable complex, and (6) floating-drop vapor diffusion. Using our approach, the receptor-binding head domain of MV-H covalently fused with SLAM was successfully crystallized and diffraction was improved from 4.5 ƅ to a final resolution of 3.15 ƅ . These combinational methods would be useful as crystallization strategies for complexes of glycoproteins and their receptors.Measles virus (MV), one of the most contagious agents, infects immune cells using the signaling lymphocyte activation molecule (SLAM) on the cell surface. A complex of SLAM and the attachment protein, hemagglutinin (MVH), has remained elusive due to the intrinsic handling difficulty including glycosylation. Furthermore, crystals obtained of this complex are either nondiffracting or poorly-diffracting. To solve this problem, we designed a systematic approach using a combination of the following techniques; (1) a transient expression system in HEK293SGnTI(-) cells, (2) lysine methylation, (3) structure-guided mutagenesis directed at better crystal packing, (4) Endo H treatment, (5) single-chain formation for stable complex, and (6) floating-drop vapor diffusion. Using our approach, the receptor-binding head domain of MV-H covalently fused with SLAM was successfully crystallized and diffraction was improved from 4.5 ƅ to a final resolution of 3.15 ƅ . These combinational methods would be useful as crystallization strategies for complexes of glycoproteins and their receptors

    Selective sorption of oxygen and nitrous oxide by an electron donor-incorporated flexible coordination network

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    Incorporating strong electron donor functionality into flexible coordination networks is intriguing for sorption applications due to a built-in mechanism for electron-withdrawing guests. Here we report a 2D flexible porous coordination network, [Niā‚‚(4, 4ā€²-bipyridine)(VTTF)ā‚‚]n(1) (where Hā‚‚VTTFā€‰=ā€‰2, 2ā€²-[1, 2-bis(4-benzoic acid)-1, 2ethanediylidene]bis-1, 3-benzodithiole), which exhibits large structural deformation from the as-synthesized or open phase (1Ī±) into the closed phase (1Ī²) after guest removal, as demonstrated by X-ray and electron diffraction. Interestingly, upon exposure to electron-withdrawing species, 1Ī² reversibly undergoes guest accommodation transitions; 1Ī±āŠƒOā‚‚ (90ā€‰K) and 1Ī±āŠƒNā‚‚O (185ā€‰K). Moreover, the 1Ī² phase showed exclusive Oā‚‚ sorption over other gases (Nā‚‚, Ar, and CO) at 120ā€‰K. The phase transformations between the 1Ī± and 1Ī² phases under these gases were carefully investigated by in-situ X-ray diffraction, in-situ spectroscopic studies, and DFT calculations, validating that the unusual sorption was attributed to the combination of flexible frameworks and VTTF (electron-donor) that induces strong interactions with electron-withdrawing species

    Combined Laparoscopic and CT Monitoring of the Ice-Ball Margin during Cryoablation for Renal Cell Carcinoma Associated with von Hippel-Lindau Disease: First Case

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    We report a 47-year-old Japanese female with 10 previous treatments for multiple bilateral renal cell carcinoma (RCC) associated with von Hippel-Lindau disease. The 14-mm right lower pole renal tumor was in contact with the right ureter. Laparoscopic cryoablation was performed to protect the ureter wrapped with gauze. Computed tomography (CT) monitoring was used to confirm the precise ā‰„ 6 mm ice-ball margin. There was no local progression at 6-months post-surgery. The serum creatinine has been stable. This is apparently the first report of combined laparoscopic and CT monitoring of an ice-ball formation and its margin during cryoablation for RCC

    Clinical Influence of Cervical Spinal Canal Stenosis on Neurological Outcome after Traumatic Cervical Spinal Cord Injury without Major Fracture or Dislocation

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    Study DesignRetrospective case series.PurposeTo clarify the influence of cervical spinal canal stenosis (CSCS) on neurological functional recovery after traumatic cervical spinal cord injury (CSCI) without major fracture or dislocation.Overview of LiteratureThe biomechanical etiology of traumatic CSCI remains under discussion and its relationship with CSCS is one of the most controversial issues in the clinical management of traumatic CSCI.MethodsTo obtain a relatively uniform background, patients non-surgically treated for an acute C3ā€“4 level CSCI without major fracture or dislocation were selected. We analyzed 58 subjects with traumatic CSCI using T2-weighted mid-sagittal magnetic resonance imaging. The sagittal diameter of the cerebrospinal fluid (CSF) column, degree of canal stenosis, and neurologic outcomes in motor function, including improvement rate, were assessed.ResultsThere were no significant relationships between sagittal diameter of the CSF column at the C3ā€“4 segment and their American Spinal Injury Association motor scores at both admission and discharge. Moreover, no significant relationships were observed between the sagittal diameter of the CSF column at the C3ā€“4 segment and their neurological recovery during the following period.ConclusionsNo relationships between pre-existing CSCS and neurological outcomes were evident after traumatic CSCI. These results suggest that decompression surgery might not be recommended for traumatic CSCI without major fracture or dislocation despite pre-existing CSCS

    DNA uracil repair initiated by the archaeal ExoIII homologue Mth212 via direct strand incision

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    No genes for any of the known uracil DNA glycosylases of the UDG superfamily are present in the genome of Methanothermobacter thermautotrophicus Ī”H, making it difficult to imagine how DNA-U repair might be initiated in this organism. Recently, Mth212, the ExoIII homologue of M. thermautotrophicus Ī”H has been characterized as a DNA uridine endonuclease, which suggested the possibility of a novel endonucleolytic entry mechanism for DNA uracil repair. With no system of genetic experimentation available, the problem was approached biochemically. Assays of DNA uracil repair in vitro, promoted by crude cellular extracts, provide unequivocal confirmation that this mechanism does indeed operate in M. thermautotrophicus Ī”H

    DNA uracil repair initiated by the archaeal ExoIII homologue Mth212 via direct strand incision

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    No genes for any of the known uracil DNA glycosylases of the UDG superfamily are present in the genome of Methanothermobacter thermautotrophicus Ī”H, making it difficult to imagine how DNA-U repair might be initiated in this organism. Recently, Mth212, the ExoIII homologue of M. thermautotrophicus Ī”H has been characterized as a DNA uridine endonuclease, which suggested the possibility of a novel endonucleolytic entry mechanism for DNA uracil repair. With no system of genetic experimentation available, the problem was approached biochemically. Assays of DNA uracil repair in vitro, promoted by crude cellular extracts, provide unequivocal confirmation that this mechanism does indeed operate in M. thermautotrophicus Ī”H

    The Quiescent Intracluster Medium in the Core of the Perseus Cluster

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    Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host of astrophysical processes. Knowledge of the dynamics of the pervasive hot gas, which dominates in mass over stars in a cluster, is a crucial missing ingredient. It can enable new insights into mechanical energy injection by the central supermassive black hole and the use of hydrostatic equilibrium for the determination of cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50 million K diffuse hot plasma filling its gravitational potential well. The Active Galactic Nucleus of the central galaxy NGC1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These likely induce motions in the intracluster medium and heat the inner gas preventing runaway radiative cooling; a process known as Active Galactic Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus cluster core, which reveal a remarkably quiescent atmosphere where the gas has a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s is found across the 60 kpc image of the cluster core. Turbulent pressure support in the gas is 4% or less of the thermodynamic pressure, with large scale shear at most doubling that estimate. We infer that total cluster masses determined from hydrostatic equilibrium in the central regions need little correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July
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