496 research outputs found

    Suzaku Observation of the Intermediate Polar V1223 Sagittarii

    Full text link
    We report on the Suzaku observation of the intermediate polar V1223 Sagittarii. Using a multi-temperature plasma emission model with its reflection from a cold matter, we obtained the shock temperature to be 37.9^{+5.1}_{-4.6} keV. This constrains the mass and the radius of the white dwarf (WD) in the ranges 0.82^{+0.05}_{-0.06} solar masses and (6.9+/-0.4)x10^8 cm, respectively, with the aid of a WD mass-radius relation. The solid angle of the reflector viewed from the post-shock plasma was measured to be Omega/2pi = 0.91+/-0.26. A fluorescent iron Kalpha emission line is detected, whose central energy is discovered to be modulated with the WD rotation for the first time in magnetic-CVs. Detailed spectral analysis indicates that the line comprises of a stable 6.4 keV component and a red-shifted component, the latter of which appears only around the rotational intensity-minimum phase. The equivalent width (EW) of the former stable component ~80 eV together with the measured Omega indicates the major reflector is the WD surface, and the shock height is not more than 7% of the WD radius. Comparing this limitation to the height predicted by the Aizu model (1973), we estimated the fractional area onto which the accretion occurs to be < 7x10^{-3}$ of the WD radius, which is the most severe constraint in non-eclipsing IPs. The red-shifted iron line component, on the other hand, can be interpreted as emanating from the pre-shock accretion flow via fluorescence. Its EW (28^{+44}_{-13} eV) and the central energy (6.30_{-0.05}^{+0.07} keV) at the intensity-minimum phase are consistent with this interpretation.Comment: 25 pages, 13 figures, accepted for publication in PASJ (Suzaku & MAXI special issue

    "In vivo cryotechnique" for paradigm shift to "living morphology" of animal organs

    Get PDF
    The morphological study has been one of the major approaches in medical and biological fields. For the last century, the conventional chemical fixation and alcohol dehydration were commonly used as an easy preparation method, but it was frequently pointed out that they usually yield many structural artifacts during their preparation processes. Although both conventional quick-freezing and high-pressure freezing methods, by which animal tissues are resected and frozen for physical fixation,can reduce such structural artifacts, the tissues have to be removed from living animal organs for the freezing. Therefore, such specimens are inevitably exposed to noxious stresses of anoxia and ischemia, exhibiting only dead morphological states of animal tissues without blood circulation. To the contrary, our "in vivo cryotechnique", by which all cells and tissues in animal bodies are cryofixed in vivo, can prevent such artifacts of resected specimens. By means of the cryotechnique, it is now possible to reveal the in vivo morphology of cells and tissues in living animal organs. Actually, it has been already applied to several animal organs, such as kidney, liver, intestine, cerebellum, eye ball, blood vessel, and joint cartilage, and brought new morphological findings, reflecting their physiological significance, which had been difficult to demonstrate by the conventional preparation methods. Moreover, its application to immunohistochemistry has also revealed more precise immunolocalizations of dynamically changing molecules in living animal organs, easily translocated by ischemic stresses and anoxia caused during the tissue resection. The "in vivo cryotechnique" allows us to perform novel morphological investigations of "living" morphological states, and develops new medical and biological fields with "living morphology" during this 21st century.Biomedical Reviews 2004; 15: 1-19

    Defect in Synaptic Vesicle Precursor Transport and Neuronal Cell Death in KIF1A Motor Protein–deficient Mice

    Get PDF
    The nerve axon is a good model system for studying the molecular mechanism of organelle transport in cells. Recently, the new kinesin superfamily proteins (KIFs) have been identified as candidate motor proteins involved in organelle transport. Among them KIF1A, a murine homologue of unc-104 gene of Caenorhabditis elegans, is a unique monomeric neuron– specific microtubule plus end–directed motor and has been proposed as a transporter of synaptic vesicle precursors (Okada, Y., H. Yamazaki, Y. Sekine-Aizawa, and N. Hirokawa. 1995. Cell. 81:769–780). To elucidate the function of KIF1A in vivo, we disrupted the KIF1A gene in mice. KIF1A mutants died mostly within a day after birth showing motor and sensory disturbances. In the nervous systems of these mutants, the transport of synaptic vesicle precursors showed a specific and significant decrease. Consequently, synaptic vesicle density decreased dramatically, and clusters of clear small vesicles accumulated in the cell bodies. Furthermore, marked neuronal degeneration and death occurred both in KIF1A mutant mice and in cultures of mutant neurons. The neuronal death in cultures was blocked by coculture with wild-type neurons or exposure to a low concentration of glutamate. These results in cultures suggested that the mutant neurons might not sufficiently receive afferent stimulation, such as neuronal contacts or neurotransmission, resulting in cell death. Thus, our results demonstrate that KIF1A transports a synaptic vesicle precursor and that KIF1A-mediated axonal transport plays a critical role in viability, maintenance, and function of neurons, particularly mature neurons

    Adult T-Cell Leukemia/Lymphoma with Gastric Lesion

    Get PDF
    A case of adult T-cell leukemia/lymphoma with a gastric tumor is presented. The patient was a 72-year-old woman who had been admitted to our hospital because of epigastric pain. Upper gastrointestinal endoscopy disclosed polypoid region in the antrum of the stomach. Specimens taken from this region revealed malignant lymphoma. Although the patient was serologically positive for human T-cell leukemia virus type I antibody. A chest X-ray, abdominal ultrasonography, and whole body computed tomography revealed no lymphadenopathy. We diagnosed her to have primary gastric malignant lymphoma and thus performed a total gastrectomy with regional lymph node excision and a splenectomy. Both histological and immunohistochemical studies of the resected specimen showed the lymphoma to be a diffuse pleomorphic type with a T cell phenotype. A radical surgical resection could be performed. At nine months postoperatively, she was again admitted to our hospital because of abdominal pain. Both ultrasonography and computed tomography revealed lymph node swelling around the surrounding the para aorta. She was treated with systematic chemotherapy. Unfortunately, she died at one year after the operation

    Factors associated with development and distribution of granular/fuzzy astrocytes in neurodegenerative diseases

    Get PDF
    Granular/fuzzy astrocytes (GFAs), a subtype of “aging‐related tau astrogliopathy,” are noted in cases bearing various neurodegenerative diseases. However, the pathogenic significance of GFAs remains unclear. We immunohistochemically examined the frontal cortex, caudate nucleus, putamen and amygdala in 105 cases composed of argyrophilic grain disease cases (AGD, N = 26), and progressive supranuclear palsy (PSP, N = 10), Alzheimer’s disease (AD, N = 20) and primary age‐related tauopathy cases (PART, N = 18) lacking AGD, as well as 31 cases bearing other various neurodegenerative diseases to clarify (i) the distribution patterns of GFAs in AGD, and PSP, AD and PART lacking AGD, (ii) the impacts of major pathological factors and age on GFA formation and (iii) immunohistochemical features useful to understand the formation process of GFAs. In AGD cases, GFAs consistently occurred in the amygdala (100%), followed by the putamen (69.2%) and caudate nucleus and frontal cortex (57.7%, respectively). In PSP cases without AGD, GFAs were almost consistently noted in all regions examined (90–100%). In AD cases without AGD, GFAs were less frequent, developing preferably in the putamen (35.0%) and caudate nucleus (30.0%). PART cases without AGD had GFAs most frequently in the amygdala (35.3%), being more similar to AGD than to AD cases. Ordered logistic regression analyses using all cases demonstrated that the strongest independent factor of GFA formation in the frontal cortex and striatum was the diagnosis of PSP, while that in the amygdala was AGD. The age was not significantly associated with GFA formation in any region. In GFAs in AGD cases, phosphorylation and conformational change of tau, Gallyas‐positive glial threads indistinguishable from those in tufted astrocytes, and the activation of autophagy occurred sequentially. Given these findings, AGD, PSP, AD and PART cases may show distinct distributions of GFAs, which may provide clues to predict the underlying processes of primary tauopathies

    Large Benign Polyp of the Extrahepatic Bile Duct (Mimicking Bile Duct Cancer)

    Get PDF
    An 85-year-old woman was admitted because of epigastric pain. The endoscopic examination showed the presence of duodenal ulcer. Abdominal ultrasonography and computed tomography revealed a dilatation of the common bile duct, but no apparent stones were seen in the biliary tract including the gall bladder. In addition, endoscopic retrograde cholangiography showed a filling defect, 20x30 mm in size, in the extrahepatic bile duct. The laboratory data and serum tumor makers were within normal limits. Carcinoma of the extrahepatic bile duct was tentatively made. At operation, an exploration using cholangioscopy and ultrasonography failed to reveal any malignancy. She underwent a local excision of the biliary tumor. Histological examination of the resected specimen showed a benign papillary adenoma. This case is herein reported because of rarity of the disease, which was incidentally found

    Unilateral minimal ovarian cancer with peritoneal implant and an intraepithelial carcinoma in the contralateral fallopian tube

    Get PDF
    Here we present postoperative pathology of an 82-year-old woman who presented with massive ascites, and an implant-like adenocarcinoma on her intrapelvic peritoneum, which revealed a minimal (<5mm) serous adenocarcinoma on her left ovary and an intraepithelial carcinoma on inner surface of her right Fallopian tube.  The left ovarian serous adenocarcinoma may have originated as an intraepithelial carcinoma on contralateral Fallopian tube

    Wandering and fecal smearing in people with dementia

    Get PDF
    ABSTRACT Background: Wandering and fecal smearing (scatolia) are among the problematic behaviors in dementia, and many caregivers are troubled by these behaviors. The purpose of this study was to clarify the clinical characteristics of patients with these symptoms
    • 

    corecore