5,538 research outputs found
Malignant melanoma of the conjunctiva: a case report with examination of KIT and PDGFRA
Although many clinicopathological studies of malignant melanoma of the conjunctiva have been reported, there have been no studies of the expression and gene mutations of KIT and PDGFRA in melanoma of the conjunctiva. A 69-year-old Japanese woman consulted our hospital because of black mass (0.7 Ă— 0.7 Ă— 0.6 cm) in the conjunctiva. A biopsy was taken. The biopsy showed malignant epithelioid cells with melanin deposition. Immunohistochemically, the tumor was positive for S100 protein, HMB45, p53, Ki-67 (labeling=30%), KIT and PDGFRA. The tumor was negative for pancytokeratins (AE1/3 and CAM5.2). A genetic analysis using PCR-direct sequencing revealed no mutations of KIT gene (exons 9, 11, 13, and 17) and PDGFRA gene (exons 12 and 18). The pathological diagnosis was conjunctival melanoma. Despite chemotherapy, the patient developed multiple metastases of melanoma, and died of melanoma 7 years after the biopsy. In conclusion, the author reported a case of melanoma of conjunctive expressing KIT and PDGFRA proteins without gene mutations of KIT and PDGFRA
Universal magneto-orbital ordering in the divalent -site quadruple perovskite manganites MnO ( = Ca, Sr, Cd, and Pb)
Through analysis of variable temperature neutron powder diffraction data, we
present solutions for the magnetic structures of SrMnO,
CdMnO, and PbMnO in all long-range ordered phases. The
three compounds were found to have magnetic structures analogous to that
reported for CaMnO. They all feature a higher temperature lock-in
phase with \emph{commensurate} magneto-orbital coupling, and a delocked,
multi-\textbf{k} magnetic ground state where \emph{incommensurate}
magneto-orbital coupling gives rise to a constant-moment magnetic helix with
modulated spin helicity. CdMnO represents a special case in which
the orbital modulation is commensurate with the crystal lattice and involves
stacking of fully and partially polarized orbital states. Our results provide a
robust confirmation of the phenomenological model for magneto-orbital coupling
previously presented for CaMnO. Furthermore, we show that the model
is universal to the quadruple perovskite manganites synthesised to
date, and that it is tunable by selection of the -site ionic radius
Transient thermoelectricity in a vibrating quantum dot in Kondo regime
We investigate the time evolution of the thermopower in a vibrating quantum
dot suddenly shifted into the Kondo regime via a gate voltage by adopting the
time-dependent non-crossing approximation and linear response Onsager
relations. Behaviour of the instantaneous thermopower is studied for a range of
temperatures both in zero and strong electron-phonon coupling. We argue that
inverse of the saturation value of decay time of thermopower to its steady
state value might be an alternative tool in determination of the Kondo
temperature and the value of the electron-phonon coupling strength.Comment: 5 pages, 4 figures, to appear in Physics Letters
Nested variant of urothelial carcinoma of the urinary bladder
The nested variant of urothelial carcinoma (NVUC) is characterized by the presence of benign-appearing urothelial carcinoma cells in the lamina propria, sparing the surface urothelial involvement. NVUC shows aggressive clinical course despite of benign-looking histology. Herein reported are two cases of NVUC. One is 80-year-old woman, and another is 78-year-old man. In both cases, atypical cells forming nests and tubules were seen in the lamina propria without surface urothelial involvement. One case resembled nephrogenic metaplasia and another proliferated Brunn's nest or inverted papilloma. Immunohistochemically, both cases showed positive p53 and high Ki67 labeling, suggesting that both cases are malignant. Immunohistochemically, one case was characterized by positive cytokeratins, EMA, p53, Ki-67 (labeling=15%), α-methylacyl CoA racemase, CA19-9, and MUC1, and another case by positive cytokeratins, EMA, p63, p53, Ki-67 (lebeling=30%), CD10, CEA, and MUC1. Cyto keratin immunoprofiles were described and other antigens' expressions were shown. The patients are now free of tumor 6 and 15 months after the resection of the bladder tumor
X-ray and optical observations of the unique binary system HD49798/RXJ0648.0-4418
We report the results of XMM-Newton observations of HD49798/RXJ0648.0-4418,
the only known X-ray binary consisting of a hot sub-dwarf and a white dwarf.
The white dwarf rotates very rapidly (P=13.2 s) and has a dynamically measured
mass of 1.28+/-0.05 M_sun. Its X-ray emission consists of a strongly pulsed,
soft component, well fit by a blackbody with kT~40 eV, accounting for most of
the luminosity, and a fainter hard power-law component (photon index ~1.6). A
luminosity of ~10^{32} erg/s is produced by accretion onto the white dwarf of
the helium-rich matter from the wind of the companion, which is one of the few
hot sub-dwarfs showing evidence of mass-loss. A search for optical pulsations
at the South African Astronomical Observatory 1.9-m telescope gave negative
results. X-rays were detected also during the white dwarf eclipse. This
emission, with luminosity 2x10^{30} erg/s, can be attributed to HD 49798 and
represents the first detection of a hot sub-dwarf star in the X-ray band.
HD49798/RXJ0648.0-4418 is a post-common envelope binary which most likely
originated from a pair of stars with masses ~8-10 M_sun. After the current
He-burning phase, HD 49798 will expand and reach the Roche-lobe, causing a
higher accretion rate onto the white dwarf which can reach the Chandrasekhar
limit. Considering the fast spin of the white dwarf, this could lead to the
formation of a millisecond pulsar. Alternatively, this system could be a Type
Ia supernova progenitor with the appealing characteristic of a short time
delay, being the descendent of relatively massive stars.Comment: Accepted for publication on The Astrophysical Journa
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