Immunocytochemical localization of T antigen in cells of BK virus-induced hamster brain tumor.

The localization of both the large T and small t tumor (T) antigens in cultured cells (Vn 12 cells) of hamster brain tumors induced with BK virus (BKV), a new human papovavirus, was studied by an enzyme labelled antibody method at both the light and electron microscopic levels. Under the light microscope, BKV T antigen was observed in the nucleus, except for the nucleoli, of cells in interphase, and under the electron microscope it was observed in the nucleus except for the nucleoli and nuclear membrane. BKV T antigen appears to be closely associated with nuclear chromatin as previously reported for simian virus 40 tumor antigen (SV40 T antigen). The intracellular localization of BKV T antigen was the same as that of SV40 T antigen. In metaphase, BKV T antigen seems to be distributed diffusely throughout the cytoplasm except for the chromosomes. In telophase, BKV T antigen transfers from the cytoplasm to the nucleus. The migration of BKV T antigen during the cell cycle is thought to be related to the function of T antigen.</p

Effects of antioxidants on survival of adult rat hepatocytes under various oxygen tensions in serum-free primary culture.

Effects of antioxidants, such as superoxide dismutase, vitamin C, vitamin E, 4-(0-benzylphenoxy)-N-methylbutylamine hydrochloride (bifemelane), and selenite on survival of adult rat hepatocytes were examined under normoxic and hyperoxic conditions in serum-free primary culture. The tested antioxidants, except for vitamin C, significantly increased the survival rate of hepatocytes under the normoxic condition (under air). Thus, even the normoxic culture condition is hyperoxic for hepatocytes. Elevation of oxygen tension (40% O2) caused severe morphologic degeneration of hepatocytes and remarkable decrease in the survival rate of the cells. Addition of the antioxidants effectively protected hepatocytes from the morphologic degeneration, and significantly improved the survival of the cells under the hyperoxic condition. These findings indicate that the antioxidants can maintain the long-term survival of hepatocytes in serum-free primary culture.</p

Deep Near-Infrared Observations and Identifications of Chandra Sources in the Orion Molecular Cloud 2 and 3

We conducted deep NIR imaging observations of the Orion molecular cloud 2 and 3 using QUIRC on the 88-inch telescope of the University of Hawaii. Our purposes are 1) to generate a comprehensive NIR source catalog of these star forming clouds, and 2) to identify the NIR counterpart of the Chandra X-ray sources that have no counterpart in the 2MASS catalog. Our J-, H-, and K-band observations are about 2 mag deeper than those of 2MASS, and well match the current Chandra observation. We detected 1448 NIR sources, for which we derived the position, the J-, H-, and K-band magnitude, and the 2MASS counterpart. Using this catalog, we identified the NIR counterpart for about 42% of the 2MASS-unIDed Chandra sources. The nature of these Chandra sources are discussed using their NIR colors and spatial distributions, and a dozen protostar and brown dwarf candidates are identified.Comment: 39 pages, 9 postscript figures, accepted for publication in A

Suzaku Detection of an Intense X-Ray Flare from an A-type Star HD161084

We report a serendipitous detection of an intense X-ray flare from the Tycho reference source HD 161084 during a Suzaku observation of the Galactic Center region for 20 ks. The X-ray Imaging Spectrometer (XIS) recorded a flare from this A1-type dwarf or subgiant star with a flux of 1.4x10^{-12} erg s^{-1} cm^{-2} (0.5--10 keV) and a decay time scale of 0.5 hr. The spectrum is hard with a prominent Fe XXV K alpha emission line at 6.7 keV, which is explained by a 5 keV thin-thermal plasma model attenuated by a 1.4x10^{21} cm^{-2} extinction. The low extinction, which is consistent with the optical reddening, indicates that the source is a foreground star toward the Galactic Center region. Based on the spectroscopic parallax distance of 530 pc, the peak X-ray luminosity amounts to 1x10^{32} erg s^{-1} (0.5--10 keV). This is much larger than the X-ray luminosity of ordinary late-type main-sequence stars, and the X-ray emission is unattributable to a hidden late-type companion that comprises a wide binary system with the A-star. We discuss possible natures of HD 161084 and suggest that it is most likely an interacting binary with elevated magnetic activity in the companion such as the Algol-type system. The flux detected by Suzaku during the burst is 100 times larger than the quiescent level measured using the archived XMM-Newton and Chandra data. The large flux amplification makes this star a unique example among sources of this class.Comment: 8 pages, 6 figures, 2 tables, PASJ in pres

The Development of a New Setup for Video-assisted Thoracic Surgery

In order to accomplish video-assisted thoracic surgery (VATS) in a much easier and safer way, especially for assistant operators, we have developed a new display system for VATS. The original thoracoscope has been designed for this new system. The monitor is fixed at approximately 10 cm away from the surface of the chest wall just above the operative field. In using this procedure, the operator and assistants can see the patient and the monitor at the same time. According to this new idea, the previous problem in the area of hand–eye coordination and the three-dimensional understanding of this procedure can be improved compared to the image of the conventional thoracoscopy, because it is not necessary for the operator and assistants to look up at the monitors. When the thoracoscopy was placed in an adequate position to resect the target pathology, this new system led to good and easy handling of instruments, as it was with the standard thoracotomy

Synthesis, Crystal Structures, Electronic Spectra, and Magnetic Properties of Thiolato-Bridged Trinuclear Cobalt(II) Complexes with N, N, S-Tridentate Thiolate Ligands

New trinuclear CoII complexes, [{Co(apaet)2}2Co]X2 (apaet– = 2-[(3-aminopropyl)amino]ethanethiolato; X = SCN (1), ClO4 (2), NO3 (3), Cl (4), Br (5), I (6)) and [{Co(apampt)2}2Co]X2 (apampt– = 1-[(3-aminopropyl)amino]-2-methylpropane-2-thiolato; X = NO3(7), ClO4 (8), Cl (9), Br (10), I (11)), and mononuclear CoIII complexes, [Co(apaet)2]X (X = ClO4 (12), NO3 (13)), were synthesized. Single-crystal X-ray crystallography of 1 and 7 confirmed that the trinuclear complexes have a linear arrangement of octahedral CoIIS2N4-tetrahedral CoIIS4-octahedral CoIIS2N4 chromophores where two thiolate ligands are coordinated to each terminal Co atom in a mer coordination mode and the two thiolato S atoms are further bound to the central Co atom, which is consistent with the electronic spectra and antiferromagnetic propertie

Electron microscopic features of a brain tumor induced in hamster by BK virus, a human papova virus.

In order to locate the target cells for malignant transformation by BK virus (a human papova virus) in hamster brain, electron microscopic observation of tumor originally induced in hamster brain by BK virus was performed. With light microscopy, the BK virus-induced tumor (Vn 17) bore a close resemblance to human malignant ependymoma. Under the electron microscope, numerous microvilli and few cilia were visible on the surface of the tumor cells. These tumor cells were joined to each other by desmosomes. Gap junctions were not observed. Multilayered cuboidal cells were observed around the lumen and blood vessels in the tumor. With regard to fine structure, three types of Vn 17 cells were recognized; ependymal like cells, tanycytes with prominent cell processes, and undifferentiated cells with few cytoplasmic organelles. There was no basal lamina between the ependymal cells and the connective tissue stroma. The Vn 17 cells showed some similarity to the ultrastructural features of the epemdymal cells of newborn rabbits, suggesting that the target cells for Vn 17 may be cells related to ependyma. Malignant transformation of the cells would be initiated in the early stages after BK virus inoculation into the brain of newborn hamsters.</p

Mechanisms involved in an increment of multimodal excitability of medullary and upper cervical dorsal horn neurons following cutaneous capsaicin treatment

<p>Abstract</p> <p>Background</p> <p>In order to evaluate mechanisms that may underlie the sensitization of trigeminal spinal subnucleus caudalis (Vc; the medullary dorsal horn) and upper cervical spinal cord (C1-C2) nociceptive neurons to heat, cold and mechanical stimuli following topical capsaicin treatment of the facial skin, nocifensive behaviors as well as phosphorylation of extracellular regulated-kinase (pERK) in Vc and C1-C2 neurons were studied in rats.</p> <p>Results</p> <p>Compared to vehicle application, capsaicin application to the lateral facial skin produced 1 hour later a flare in the skin, and also induced significantly greater nocifensive behaviors to heat, cold or mechanical stimulus of the lateral facial skin. The intrathecal (i.t.) injection of the MEK inhibitor PD98059 markedly attenuated the nocifensive behaviors to these stimuli in capsaicin-treated rats. Moreover, the number of pERK-like immunoreactive (pERK-LI) cells in Vc and C1-C2 was significantly larger following the heat, cold and mechanical stimuli in capsaicin-treated rats compared with vehicle-treated rats. The number of pERK-LI cells gradually increased following progressive increases in the heat or mechanical stimulus intensity and following progressive decrease in the cold stimulus. The ERK phosphorylation in Vc and C1-C2 neurons was strongly inhibited after subcutaneous injection of the capsaicin antagonist capsazepine in capsaicin-treated rats.</p> <p>Conclusion</p> <p>The present findings revealed that capsaicin treatment of the lateral facial skin causes an enhancement of ERK phosphorylation in Vc and C1-C2 neurons as well as induces nocifensive behavior to heat, cold and mechanical simulation of the capsaicin-treated skin. The findings suggest that TRPV1 receptor mechanisms in rat facial skin influence nociceptive responses to noxious cutaneous thermal and mechanical stimuli by inducing neuroplastic changes in Vc and C1-C2 neurons that involve in the MAP kinase cascade.</p

Geometrical Isomerism in Ru2Au Heterometal Assembly: Cis-Linking of Tetracyanidoaurate to Tetrakis(Μ-Butanoato)Diruthenium

A heterometal assembled complex of tetrakis(μ-butanoato)diruthenium(II,III) and tetracyanidoaurate(III) [RuIIRuIII(n-C3H7COO)4AuIII(CN)4]n was synthesized and characterized by the elemental analysis and infrared spectroscopy. The single-crystal X-ray structure analysis revealed that the complex consists of zigzag chain molecules of alternating arrangement of the Ru2(n-C3H7COO)4+ and Au(CN)4– units with cis-bridging mode of the Au(CN)4– units. The temperature dependence of the magnetic susceptibility data (4.5—300 K) showed that the magnetic interaction between the dinuclear RuIIRuIII units (S= 3/2) is negligibly small with a zero-field splitting parameter D value of 60 cm-1