硫黄で増殖したAcidthiobacillus caldus GO-1株による還元型硫黄化合物の酸化機構

The oxidation of reduced sulfur compounds was studied by using resting cells of sulfur-grown Acidithiobacillus caldus strain GO-1. The optimum pHs for the oxidation of thiosulfate, tetrathionate, sulfur, sulfite and sulfide were 2, 3, 3-6, 7 and 7, respectively. The highest oxidation rate was observed with sulfite. The oxidation rates of the reduced sulfur compounds were measured in the absence or presence of inhibitors and uncouplers. 2, 4-dinitrophenol (DNP) and carbonyl cyanide-m-chlorophenylhydrazone (CCCP) strongly inhibited the oxidations of sulfur and sulfite. N-Ethylmaleimide (NEM) strongly inhibited the oxidation of tetrathionate and sulfur. 2-heptyl-4-hydroxy-quinoline-N-oxide(HQNO) inhibited the oxidation of sulfur and sulfite. The results suggested that tetrathionate was oxidized in the periplasmic space, and sulfur and sulfite were oxidized in the cytoplasm. Pyridine ferrohemochromes prepared from the membrane of strain GO-1 cell revealed the involvement of cytochromes b and c. Ubiquinol oxidase activity was detected in strain GO-1 cell, but cytochrome c oxidase measured by using mammalian cytochrome c as an electron donor was not detected in the cell. On the basis of the results a model for the metabolism of the reduced sulfur compounds by At. caldus strain GO-1 was proposed.硫黄で増殖したAcidithiobacilluscaldusGO-1株の休止菌体を用いて，還元型硫黄化合物の酸化機構を検討した．GO-１株は，チオ硫酸，テトラチオン酸，元素硫黄，亜硫酸及び硫化物の酸化活性を持っており，その最適pHは，それぞれ２，３，３-６，７及び７であった．これらの酸化活性の中で，亜硫酸の酸化速度が最も高かった．阻害剤やアンカップラーを用いて，還元型硫黄化合物の酸化への影響を調べた結果，DNPとCCCPによる元素硫黄及び亜硫酸酸化活性の強い阻害，NEMによるテトラチオン酸及び硫黄酸化活性の強い阻害，およびHQNOによる元素硫黄及び亜硫酸酸化活性の阻害が観察された．これらの結果は，テトラチオン酸がペリプラズマで，硫黄及び亜流酸が細胞質で，それぞれ酸化されることを示唆した．細胞膜からピリジンフェロヘモクロームを調製して，シトクロームの構成成分を検討した結果，ヘムb及びcが検出された．また，末端酸化酵素の活性を検討した結果，ユビキノール酸化酵素の活性は検出されたが，哺乳類のシトクロームを用いて測定したシトクロームc酸化酵素の活性は検出されなかった．これらの結果に基づいて，At.caldusGO-１株の還元型硫黄化合物の酸化機構を考察した

Endogenous and Inhaled Nitric Oxide for the Treatment of Pulmonary Hypertension

Since the discovery of nitric oxide (NO) as a physiological substance produced in the endothelium, the impairment of endothelial NO production and reactivity of the pulmonary vasculature to NO have been described in animal models and patients with pulmonary hypertension (PH). The NO synthase-NO-cyclic guanosine monophosphate (cGMP) pathway is impaired in pulmonary arterial hypertension (PAH), pulmonary veno-occlusive disease (PVOD), pulmonary capillary hemangiomatosis (PCH), chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF). Pioneering clinicians conceived that NO can be administered to the lung by inhalation and used this strategy to treat PH in humans and acute hypoxic PH in animal models. Inhaled NO (iNO) selectively decreases pulmonary arterial pressure with no changes in systemic arterial pressure. When iNO diffuses into the blood, it is converted to NO3−, thereby losing its vasodilatory effects. NO might then be recycled in hypoxic remote organs, where NO3− and NO2− are reduced to NO. In the present chapter, the metabolic fate of iNO, based on previous air pollution research in Japan, is discussed. Then, we describe recent clinical applications of iNO in pediatric patients with various diseases, including bronchopulmonary dysplasia (BPD), persistent PH of neonates, and congenital diaphragmatic hernia (CDH). We also summarize the role of iNO in the catheterization lab, including acute vasoreactivity testing to assess prognosis, indications for specific PH therapy, and operability of congenital heart disease

Induction of outward current by orexin-B in mouse peritoneal macrophages

AbstractTo define effects of novel feeding regulating peptides, orexins, in immunocompetent cells, ion channel activity in mouse peritoneal macrophages was analyzed by the perforated patch-clamp method. Orexin-B (OX-B) induced an outward current at smaller holding potentials than K+ equilibrium potentials. Reversal potentials of OX-B induced current were dependent on external K+ concentrations but not on external Cl− concentration. Orexin-A is less effective than OX-B. Quinine blocked the outward current and tetraethylammonium partially suppressed the current. These results suggest that OX-B can modulate macrophage functions through the activation of Ca2+-dependent K+ channels

Serum Concentration of Myosin Light Chain I and Left Ventricular Shortening Fraction in Neonates

We compared the serum concentrations of myosin light chain I (MLC-I) and left ventricular shortening fraction (LVSF) measured by echocardiography of 13 normal neonates with those of 38 neonates with fetal distress, neonatal asphyxia, or cardiovascular/respiratory diseases not associated with structural abnormalities. The diseased group included 9 neonates with elevated MLC-I concentrations and 18 with low LVSF. Elevated MLC-I concentrations were frequently noted in neonates with transient myocardial ischemia and persistent pulmonary hypertension of the newborn, suggesting a high specificity of MLC-I elevation in these diseases. Although echocardiographically determined LVSF identifies the affected sections of the myocardium, it did not allow rating of the severity of the disorder. There was no correlation between MLC-I and LVSF probably due to therapeutic interventions and pulmonary hypertension. Our results suggest that MLC-I is a useful marker of neonatal myocardial diseases

RETROPERITONEAL SCHWANNOMA : A CASE REPORT AND REVIEW OF THE LITERATURE

Reported herein is a rare case of retroperitoneal schwannoma in a patient without von Recklinghausen's disease. This patient was free of symptoms, and the tumor was found by chance during a periodical physical examination. Complete excision of the tumor was performed, and as of this writing, 36 months after the operation, the patient is free of the disease. In addition, a review was carried out on the 121 cases of retroperitoneal schwannoma reported in the Japanese literature from 1981 to 1992. In this series, malignant tumors were seen in 26.4% of all cases, and when this tumor was found in association with von Recklinghausen's disease, the malignancy rate increased to 52.9%. Thirty seven percent of the patients with malignant tumors had died at the time of writing of their case report, and their mean survival period was 18 months after the first surgical treatment. All the patients with benign tumors underwent complete resection and had a good prognosis

Quantitative evaluation of temporal partial coherence using 3D Fourier transforms of through-focus TEM images

AbstractWe evaluate the temporal partial coherence of transmission electron microscopy (TEM) using the three-dimensional (3D) Fourier transform (FT) of through-focus images. Young's fringe method often indicates the unexpected high-frequency information due to non-linear imaging terms. We have already used the 3D FT of axial (non-tilted) through-focus images to reduce the effect of non-linear terms on the linear imaging term, and demonstrated the improvement of monochromated lower-voltage TEM performance [Kimoto et al., Ultramicroscopy 121 (2012) 31–39]. Here we apply the 3D FT method with intentionally tilted incidence to normalize various factors associated with a TEM specimen and an imaging device. The temporal partial coherence of two microscopes operated at 30, 60 and 80kV is evaluated. Our method is applicable to such cases where the non-linear terms become more significant in lower acceleration voltage or aberration-corrected high spatial resolution TEM

VERA monitoring of the radio jet 3C 84 during 2007--2013: detection of non-linear motion

We present a kinematic study of the subparsec-scale radio jet of the radio galaxy 3C 84/NGC 1275 with the VLBI Exploration of Radio Astrometry (VERA) array at 22 GHz for 80 epochs from 2007 October to 2013 December. The averaged radial velocity of the bright component "C3" with reference to the radio core is found to be $0.27 pm 0.02c$ between 2007 October and 2013 December. This constant velocity of C3 is naturally explained by the advancing motion of the head of the mini-radio lobe. We also find a non-linear component in the motion of C3 with respect to the radio core. We briefly discuss possible origins of this non-linear motion.Comment: 11 pages, 7 figures, 8 tables (table 1 - 5 are supplementaries), accepted for publication on PAS

ASTE CO(3-2) Mapping toward the Whole Optical Disk of M 83: Properties of Inter-arm GMAs

We present a new on-the-fly (OTF) mapping of CO(J=3-2) line emission with the Atacama Submillimeter Telescope Experiment (ASTE) toward the 8' x 8' (or 10.5 x 10.5 kpc at the distance of 4.5 Mpc) region of the nearby barred spiral galaxy M 83 at an effective resolution of 25''. Due to its very high sensitivity, our CO(J=3-2) map can depict not only spiral arm structures but also spur-like substructures extended in inter-arm regions. This spur-like substructures in CO(J=3-2) emission are well coincident with the distribution of massive star forming regions traced by Halpha luminosity and Spitzer/IRAC 8 um emission. We have identified 54 CO(J=3-2) clumps as Giant Molecular-cloud Associations (GMAs) employing the CLUMPFIND algorithm, and have obtained their sizes, velocity dispersions, virial masses, and CO luminosity masses. We found that the virial parameter alpha, which is defined as the ratio of the virial mass to the CO luminosity mass, is almost unity for GMAs in spiral arms, whereas there exist some GMAs whose alpha are 3 -- 10 in the inter-arm region. We found that GMAs with higher $\alpha$ tend not to be associated with massive star forming regions, while other virialized GMAs are. Since alpha mainly depends on velocity dispersion of the GMA, we suppose the onset of star formation in these unvirialized GMAs with higher alpha are suppressed by an increase in internal velocity dispersions of Giant Molecular Clouds within these GMAs due to shear motion.Comment: 42 pages, 16 figures, ApJ in press, version with high resolution figures is available via http://www.nro.nao.ac.jp/~kmuraoka/m83paper/m83aste-otf.pd

Physical Conditions in Molecular Clouds in the Arm and Interarm Regions of M51

We report systematic variations in the emission line ratio of the CO J = 2-1 and J = 1-0 transitions (R_(2-1/1-0)) in the grand-design spiral galaxy M51. The R_(2-1/1-0) ratio shows clear evidence for the evolution of molecular gas from the upstream interarm regions into the spiral arms and back into the downstream interarm regions. In the interarm regions, R_(2-1/1-0) is typically 0.7 (often 0.8-1.0) in the spiral arms, particularly at the leading (downstream) edge of the molecular arms. These trends are similar to those seen in Galactic GMCs with OB star formation (presumably in the Galactic spiral arms). R_(2-1/1-0) is also high, ~0.8-1.0, in the central region of M51. Analysis of the molecular excitation using a Large Velocity Gradient radiative transfer calculation provides insight into the changes in the physical conditions of molecular gas between the arm and interarm regions: cold and low-density gas (≾ 10 K, ≾ 300 cm^(–3)) is required for the interarm GMCs, but this gas must become warmer and/or denser in the more active star-forming spiral arms. The ratio R_(2-1/1-0) is higher in areas of high 24 μm dust surface brightness (which is an approximate tracer of star formation rate surface density) and high CO(1-0) integrated intensity (i.e., a well-calibrated tracer of total molecular gas surface density). The systematic enhancement of the CO(2-1) line relative to CO(1-0) in luminous star-forming regions suggests that some caution is needed when using CO(2-1) as a tracer of bulk molecular gas mass, especially when galactic structures are resolved