Analysis of Acid Dissociation Equilibrium of Bupropion by Capillary Zone Electrophoresis After Degradation Under Heat

An acid dissociation constant (pKa) of bupropion has been determined in an aqueous solution by capillary zone electrophoresis (CZE). Electrophoretic mobility of bupropion was measured by CZE over its acid-dissociating pH range, and a pKa value has been determined as 8.75±0.02 (mean ± standard error, ionic strength: 0.010 mol dm−3). Although bupropion degrades under heated and alkaline conditions and the degraded species from bupropion coexist in the aqueous solution, the pKa value of bupropion can also be determined by CZE with the residual bupropion without any interference from the degraded species. The pKa value determined after the heat-degradation was 8.74±0.02; the result agreed well with the one determined with the freshly prepared solution. Utilization of the separation characteristics of CZE has been demonstrated with bupropion for the analysis of the fast equilibrium of acid-base reaction under the coexistence of the degraded species

Hidden particle production at the ILC

In a class of new physics models, new physics sector is completely or partly hidden, namely, singlet under the Standard Model (SM) gauge group. Hidden fields included in such new physics models communicate with the Standard Model sector through higher dimensional operators. If a cutoff lies in the TeV range, such hidden fields can be produced at future colliders. We consider a scalar filed as an example of the hidden fields. Collider phenomenology on this hidden scalar is similar to that of the SM Higgs boson, but there are several features quite different from those of the Higgs boson. We investigate productions of the hidden scalar at the International Linear Collider (ILC) and study the feasibility of its measurements, in particular, how well the ILC distinguishes the scalar from the Higgs boson, through realistic Monte Carlo simulations.Comment: the version to be published in PR

Near-Infrared Imaging Survey of Faint Companions around Young Dwarfs in the Pleiades Cluster

We conducted a near-infrared imaging survey of 11 young dwarfs in the Pleiades cluster using the Subaru Telescope and the near-infrared coronagraph imager. We found 10 faint point sources, with magnitudes as faint as 20 mag in the K-band, around 7 dwarfs. Comparison with Spitzer archive images revealed that a pair of the faint sources around V 1171 Tau are very red in the infrared wavelengths, indicative of very low-mass young stellar objects. However, the results of our follow-up proper motion measurements implied that the central star and the faint sources do not share common proper motions, suggesting that they are not physically associated.Comment: 13 pages. Accepted for publication in Research in Astronomy and Astrophysic

Coronary artery spasm—Clinical features, diagnosis, pathogenesis, and treatment

SummaryCoronary (artery) spasm plays an important role in the pathogenesis of ischemic heart disease, including stable angina, unstable angina, myocardial infarction, and sudden death. The prevalence of coronary spasm differs among populations, is higher in Japan and Korea than in the Western countries probably due to genetic as well as environmental factors. Coronary spasm occurs most often from midnight to early morning and is usually not induced by exercise in the daytime. The attacks of coronary spasm are associated with either ST segment elevation or depression, or negative U wave on ECG. Patients with multi-vessel coronary spasm may suffer from lethal arrhythmia, including advanced AV block, ventricular tachycardia or fibrillation, or even sudden death, and they are often resistant to conventional medical therapy including Ca-channel blockers (CCBs). Endothelial nitric oxide (NO) activity is reduced and markers of oxidative stress are elevated in patients with coronary spasm. Thrombogenesis is enhanced and plasma levels of hsCRP and P-selection are elevated in patients with coronary spasm. Thus, patients with coronary spasm have endothelial dysfunction and are suffering from a low-grade chronic inflammation. Polymorphisms of endothelial NO synthase, smoking, and low-grade inflammation are the most important risk factors for coronary spasm. Coronary spasm is a hyper-contraction of coronary smooth muscle triggered by an increase of intracellular Ca2+ in the presence of an increased Ca2+ sensitivity. It has been shown that RhoA/ROCK pathway is involved in Ca2+ sensitivity and that the reduced endothelial NO activity results in increased Ca2+ sensitivity through enhanced RhoA/ROCK pathway. Accordingly, it is possible that in addition to CCBs, RhoA/ROCK pathway blockers may prove to be useful for the treatment of coronary spasm

Near-Infrared Coronagraphic Observations of the T Tauri Binary System UY Aur

We present a near-infrared image of UY Aur, a 0.9" separated binary system, using the Coronagraphic Imager with Adaptive Optics on the Subaru Telescope. Thanks to adaptive optics, the spatial resolution of our image was ~0.1" in the full width at half maximum of the point spread function, the highest achieved. By comparison with previous measurements, we estimated that the orbital period is ~1640 yrs and the total mass of the binary is ~1.73 solar mass. The observed H-band magnitude of the secondary varies by as much as 1.3 mag within a decade, while that of the primary is rather stable. This inconstancy may arise from photospheric variability caused by an uneven accretion rate or from the rotation of the secondary. We detected a half-ring shaped circumbinary disk around the binary with a bright southwest part but a barely detectable northeast portion. The brightness ratio is ~57. Its inner radius and inclination are about 520 AU and 42, respectively. The disk is not uniform but has remarkable features, including a clumpy structure along the disk, circumstellar material inside the inner cavity, and an extended armlike structure. The circumstellar material inside the cavity probably corresponds to a clump or material accreting from the disk onto the binary. The armlike structure is a part of the disk, created by the accretion from the outer region of the disk or encounters with other stellar systems.Comment: 16 pages, 6 figures; accepted for publication in A

Changes in Blood Coagulation and Fibrinolysis Systems after Hassab's Procedure for Portal Hypertension

The changes in the coagulation and fibrinolysis systems in 12 patients on whom Hassab's procedure was given for portal hypertension with liver cirrhosis (LC) were studied. The coagulation factors such as the platelet count, prothrombin time (PT) and fibrinogen level showed reduction before operation, while after operation these values showed significant increase. Whereas the fibrinolysis, the fibrinogen degradation products (FDP) showed no positive cases before operation, but after operation a significant rise was noted on the 7th day as the peak. It was observed from these findings that Hassab's procedure given on the cases with LC induced acceleration in the coagulation and fibrinolysis systems after operation, so that ample care should be taken for the complications including disseminated intravascular coagulation (DIC) or gastrointestinal bleeding

Combined replacement effects of human modified β-hexosaminidase B and GM2 activator protein on GM2 gangliosidoses fibroblasts

AbstractGM2 gangliosidoses are autosomal recessive lysosomal storage diseases (LSDs) caused by mutations in the HEXA, HEXB and GM2A genes, which encode the human lysosomal β-hexosaminidase (Hex) α- and β-subunits, and GM2 activator protein (GM2A), respectively. These diseases are associated with excessive accumulation of GM2 ganglioside (GM2) in the brains of patients with neurological symptoms. Here we established a CHO cell line overexpressing human GM2A, and purified GM2A from the conditioned medium, which was taken up by fibroblasts derived from a patient with GM2A deficiency, and had the therapeutic effects of reducing the GM2 accumulated in fibroblasts when added to the culture medium. We also demonstrated for the first time that recombinant GM2A could enhance the replacement effect of human modified HexB (modB) with GM2-degrading activity, which is composed of homodimeric altered β-subunits containing a partial amino acid sequence of the α-subunit, including the GSEP loop necessary for binding to GM2A, on reduction of the GM2 accumulated in fibroblasts derived from a patient with Tay-Sachs disease, a HexA (αβ heterodimer) deficiency, caused by HEXA mutations. We predicted the same manner of binding of GM2A to the GSEP loop located in the modified HexB β-subunit to that in the native HexA α-subunit on the basis of the x-ray crystal structures. These findings suggest the effectiveness of combinational replacement therapy involving the human modified HexB and GM2A for GM2 gangliosidoses