141 research outputs found

    Physics of Multidrug Efflux through a Biomolecular Complex

    Get PDF

    Гомосексуальный субъект в пространстве публичного: нарративное измерение камин-аута

    Full text link
    <div><p>Background</p><p>Although <i>Helicobacter pylori</i> (<i>H</i>. <i>pylori</i>) infection is closely associated with the development of peptic ulcer, its involvement in pathophysiology in the lower intestinal tract and gastrointestinal (GI) motility remains unclear. Glucagon-like peptide-1 (GLP-1) is a gut hormone produced in the lower intestinal tract and involved in GI motility. Here, we investigated the effect of <i>H</i>. <i>pylori</i> infection on the link between GLP-1 expression and motility of the GI tract.</p><p>Methods</p><p>C57BL/6 mice were inoculated with a <i>H</i>. <i>pylori</i> strain. Twelve weeks later, the <i>H</i>. <i>pylori</i>-infected mice underwent <i>H</i>. <i>pylori</i> eradication treatment. GI tissues were obtained from the mice at various time intervals, and evaluated for the severity of gastric inflammatory cell infiltration and immunohistochemical expression of GLP-1 and PAX6 in the colonic mucosa. Gastrointestinal transit time (GITT) was measured by administration of carmine-red solution.</p><p>Results</p><p>GLP-1 was expressed in the endocrine cells of the colonic mucosa, and PAX6 immunoreactivity was co-localized in such cells. The numbers of GLP-1- and PAX6-positive cells in the colon were significantly increased at 12 weeks after <i>H</i>. <i>pylori</i> infection and showed a positive correlation with each other. The GITT was significantly longer in <i>H</i>. <i>pylori</i>-infected mice than in non-infected controls and showed a positive correlation with GLP-1 expression. When <i>H</i>. <i>pylori</i>-infected mice underwent <i>H</i>. <i>pylori</i> eradication, GITT and PAX6/GLP-1 expression did not differ significantly from those in untreated <i>H</i>. <i>pylori</i>-infected mice.</p><p>Conclusions</p><p><i>H</i>. <i>pylori</i> infection may impair GI motility by enhancing the colonic GLP-1/PAX6 expression.</p></div

    Pattern of disease progression during third-line or later chemotherapy with nivolumab associated with poor prognosis in advanced gastric cancer: a multicenter retrospective study in Japan

    Get PDF
    [Background] Accelerated tumor growth during immunotherapy in pre-existing measurable lesions, hyperprogressive disease (HPD), has been reported. However, progression of non-measurable lesions and new lesions are frequently observed in patients with advanced gastric cancer (AGC). [Methods] This retrospective study involved AGC patients at 24 Japanese institutions who had measurable lesions and received nivolumab after ≥ 2 lines of chemotherapy. HPD was defined as a ≥ two-fold increase in the tumor growth rate of measurable lesions. The pattern of disease progression was classified according to new lesions in different organs and ascites appeared/increase of ascites. [Results] Of 245 patients, 147 (60.0%) showed progressive disease (PD) as the best response and 41 (16.7%) showed HPD during nivolumab monotherapy. There was no significant difference in overall survival (OS) between patients with HPD and those with PD other than HPD (median OS 5.0 vs 4.8 months; hazard ratio [HR] 1.0, 95% confidence interval [CI] 0.6–1.5; p = 1.0). Fifty-three patients developed new lesions in different organs and 58 had appearance/increase of ascites; these patients showed shorter OS than those without each of these features (median OS 3.3 vs 7.1 months, HR 1.8, 95% CI 1.2–2.7, p = 0.0031 for new lesions, and 3.0 vs 7.8 months, HR 2.6, 95% CI 1.8–3.8, p < 0.0001 for ascites). Thirty-one patients who had both features showed the worst prognosis (median OS 2.6 months). [Conclusions] New lesions in different organs and appearance/increase of ascites, rather than the original definition of HPD, are the patterns of disease progression associated with poor prognosis in AGC patients receiving nivolumab whose best response was PD

    Long-term follow-up after vitrectomy to treat idiopathic full-thickness macular holes: visual acuity and macular complications.

    Get PDF
    To assess time-course changes in best-corrected visual acuity (BCVA) up to 5 years after vitrectomy to treat idiopathic full-thickness macular holes (MHs) and identify the relationship of the changes to postoperative complications.Twenty-three consecutive patients with an idiopathic MH underwent vitrectomy without adjuvant treatment. BCVA and complications were assessed postoperatively.Twenty-two of 23 (95.7%) MHs closed after the first surgery, with a final anatomic success rate of 100%. The time course of the BCVA was analyzed in 20 cases in which data were obtained for over 5 years. The BCVA improved by 0.43 logarithm of the minimum angle of resolution (logMAR) unit 6 months postoperatively (P < 0.001) and continuously improved by 0.05, 0.06, and 0.07 logMAR units between 6 months and 1 year, 1 year and 3 years (by 0.11 logMAR unit between 6 months and 3 years; P = 0.049), and 3 years and 5 years (P = 0.018) postoperatively, respectively. Macular complications developed in seven (35%) of the 20 cases; the mean BCVA at 5 years in these cases was significantly (P < 0.001) worse than in cases without complications.The BCVA might improve gradually for 5 years after vitrectomy to treat MHs. However, the macular complications that can develop postoperatively could limit that possibility

    Possible interpretations of the joint observations of UHECR arrival directions using data recorded at the Telescope Array and the Pierre Auger Observatory

    Get PDF

    Entropic release of a big sphere from a cylindrical vessel

    Get PDF
    Insertion and release of a solute into and from a cylindrical vessel comprising biopolymers is a fundamental function in biological systems. In earlier works, we reported that the solvent-entropy (SE) effect plays imperative roles for insertion. Here we show that release is also achievable by the SE effect: the solute can be moved from an entrance at one end of the vessel to an exit at the other end using a continuous variation of the vessel geometry. Since the SE effect is rather insensitive to the solute–solvent affinity, our result may provide a clue to the ‘multidrug efflux’ of TolC

    On the physics of multidrug efflux through a biomolecular complex.

    Get PDF
    Insertion and release of a solute into and from a vessel comprising biopolymers is a fundamental function in a biological system. A typical example is found in a multidrug efflux transporter. "Multidrug efflux" signifies that solutes such as drug molecules with diverse properties can be handled. In our view, the mechanism of the multidrug efflux is not chemically specific but rather has to be based on a physical factor. In earlier works, we showed that the spatial distribution of the solute-vessel potential of mean force (PMF) induced by the solvent plays imperative roles in the insertion∕release process. The PMF can be decomposed into the energetic and entropic components. The entropic component, which originates from the translational displacement of solvent molecules, is rather insensitive to the solute-solvent and vessel inner surface-solvent affinities. This feature is not shared with the energetic component. When the vessel inner surface is neither solvophobic nor solvophilic, the solvents within the vessel cavity and in the bulk offer almost the same environment to any solute with solvophobicity or solvophilicity, and the energetic component becomes much smaller than the entropic component (i.e., the latter predominates over the former). Our idea is that the multidrug efflux can be realized if the insertion∕release process is accomplished by the entropic component exhibiting the insensitivity to the solute properties. However, we have recently argued that the entropic release of the solute is not feasible as long as the vessel geometry is fixed. Here we consider a model of TolC, a cylindrical vessel possessing an entrance at one end and an exit at the other end for the solute. The spatial distribution of the PMF is calculated by employing the three-dimensional integral equation theory with rigid-body models in which the constituents interact only through hard-body potentials. Since the behavior of these models is purely entropic in origin, our analysis is focused on the entropic component. We show that the entropically inserted solute can be released by a continuous variation of the vessel geometry which forms a time-dependent entropic force continuing to accelerate the solute motion to the exit. Solutes with a wide range of sizes are entropically released using the same vessel-geometry variation. The results obtained are fairly general and also applicable to the efflux pump protein AcrB and ATP-binding cassette transporter
    corecore