678 research outputs found
Convergence rate of solutions toward stationary solutions to the compressible Navier–Stokes equation in a half line
AbstractWe study a large time behavior of a solution to the initial boundary value problem for an isentropic and compressible viscous fluid in a one-dimensional half space. The unique existence and the asymptotic stability of a stationary solution are proved by S. Kawashima, S. Nishibata and P. Zhu for an outflow problem where the fluid blows out through the boundary. The main concern of the present paper is to investigate a convergence rate of a solution toward the stationary solution. For the supersonic flow at spatial infinity, we obtain an algebraic or an exponential decay rate. Precisely, if an initial perturbation decays with the algebraic or the exponential rate in the spatial asymptotic point, the solution converges to the corresponding stationary solution with the same rate in time as time tends to infinity. An algebraic convergence rate is also obtained for the transonic flow. These results are proved by the weighted energy method
Endpoint Strichartz estimates and global solutions for the nonlinear Dirac equation
We prove endpoint Strichartz estimates for the Klein-Gordon and wave equations in mixed norms on the polar coordinates in three spatial dimensions. As an application, global wellposedness of the nonlinear Dirac equation is shown for small data in the energy class with some regularity assumption for the angular variable
Hepatocyte growth factor gene therapy reduces ventricular arrhythmia in animal models of myocardial ischemia.
It was recently reported that gene therapy using hepatocyte growth factor (HGF) has the potential to preserve cardiac function after myocardial ischemia. We speculated that this HGF gene therapy could also prevent ventricular arrhythmia. To investigate this possibility, we examined the antiarrhythmic effect of HGF gene therapy in rat acute and old myocardial infarction models. Myocardial ischemia was induced by ligation of the left descending coronary artery. Hemagglutinating virus of Japan (HVJ)-coated liposome containing HGF genes were injected directly into the myocardium fourteen days before programmed pacing. Ventricular fibrillation (VF)was induced by programmed pacing. The VF duration was reduced and the VF threshold increased after HGF gene therapy ( p< 0.01). Histological analyses revealed that the number of vessels in the ischemic border zone was greatly increased after HGF gene injection. These findings revealed that HGF gene therapy has an anti-arrhythmic effect after myocardial ischemia.</p
Usefulness of body surface mapping to differentiate patients with Brugada syndrome from patients with asymptomatic Brugada syndrome.
We attempted to determine the usefulness of body surface mapping (BSM) for differentiating patients with Brugada syndrome (BS) from patients with asymptomatic Brugada syndrome (ABS). Electrocardiograms (ECG) and BSM were recorded in 7 patients with BS and 35 patients with ABS. Following the administration of Ic antiarrhythmic drugs, BSM was recorded in 5 patients with BS and 16 patients with ABS. The maximum amplitudes at J0, J20, J40 and J60 were compared between the 2 groups, as were 3-dimensional maps. The maximum amplitudes at J0, J20 and J60 under control conditions were larger in patients with BS than in patients with ABS (P < 0.05). A three-dimensional map of the ST segments under control conditions in patients with BS showed a higher peak of ST elevation in the median precordium compared to that for patients with ABS. Increases in ST elevation at J20, J40 and J60 following drug administration were greater in patients with BS than in patients with ABS (P < 0.05). Evaluation of the change in amplitude of the ST segment at E5 caused by Ic drug administration was also useful for differentiating between the 2 groups. In conclusion, BSM was useful for differentiating patients with BS from those with ABS.</p
<ORIGINAL>Quantification of Porphyromonas gingivalis by real time PCR : new primers targeting the rgpA and rgpB gene encoding RGP
We designed new primers for the quantification of Porphyromonas gingivalis by real time PCR. The new primer set targeted the rgpA and rgpB genes that encode arginine specific cysteine proteinase (Arggingipain or Rgp), one of the putative pathogenic factors of P. gingivalis. The PCR product obtained using our primers showed no by-products by melting curve analysis. The PCR product sequence showed no significant matches to other sequences by BLAST searching of genetic databases except for matches to P. gingivalis rgpA and rgpB sequence, and could not be amplified from template derived from other oral bacteria apart from P. gingivalis. Therefore, we concluded that our primers were specific for P. gingivalis rgpA and rgpB, and could be used to quantity from 10^3 to 10^7 P. gingivalis cells when applied to real time PCR
Irinotecan Hydrochloride (CPT-11) in Dialysis Patients with Gastrointestinal Cancer
We investigated changes in drug disposition and toxicities with CPT-11 in 15 dialysis patients with gastrointestinal cancers to clarify whether CPT-11 could be administered safely in such patients. For comparison, the same parameters were also investigated in 10 cancer patients not undergoing dialysis. Items investigated included (1) plasma concentrations of SN-38, SN-38G and CPT-11 at 0, 1, 12, 24, 36, 48 and 72h after administration, together with a comparison of mean AUC values for 3 dose levels of CPT-11 (50, 60 and 70mg/m2) in dialysis patients and controls;and (2) occurrence of adverse events. Several findings emerged from this study:(1) No significant difference was observed in the AUC for SN-38 or CPT-11 between the dialysis and control groups;(2) The AUC for SN-38G at each dose was significantly higher in dialysis patients;and (3) Grade 1-4 leucopenia was observed in 11 of the dialysis patients. One patient developed grade 4 leucopenia and died due to sepsis. Anorexia, diarrhea, nausea, alopecia and interstitial pneumonia occurred in 6 dialysis patients. We found changes in drug dispositions of CPT-11, SN-38 and SN-38G in dialysis patients, suggesting that hepatic excretion, especially that of SN-38G, was increased. No significant difference in occurrence of adverse events was observed between the 2 groups. This indicates that CPT-11 can be administered safely in patients on dialysis.</p
Phosphodiesterase Inhibitors Suppress Lactobacillus casei Cell-Wall-Induced NF-κB and MAPK Activations and Cell Proliferation through Protein Kinase A—or Exchange Protein Activated by cAMP-Dependent Signal Pathway
Specific strains of Lactobacillus have been found to be beneficial in treating some types of diarrhea and vaginosis. However, a high mortality rate results from underlying immunosuppressive conditions in patients with Lactobacillus casei bacteremia. Cyclic AMP (cAMP) is a small second messenger molecule that mediates signal transduction. The onset and progression of inflammatory responses are sensitive to changes in steady-state cAMP levels. L. casei cell wall extract (LCWE) develops arteritis in mice through Toll-like receptor-2 signaling. The purpose of this study was to investigate whether intracellular cAMP affects LCWE-induced pathological signaling. LCWE was shown to induce phosphorylation of the nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways and cell proliferation in mice fibroblast cells. Theophylline and phosphodiesterase inhibitor increased intracellular cAMP and inhibited LCWE-induced cell proliferation as well as phosphorylation of NF-κB and MAPK. Protein kinase A inhibitor H89 prevented cAMP-induced MAPK inhibition, but not cAMP-induced NF-κB inhibition. An exchange protein activated by cAMP (Epac) agonist inhibited NF-κB activation but not MAPK activation. These results indicate that an increase in intracellular cAMP prevents LCWE induction of pathological signaling pathways dependent on PKA and Epac signaling
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