219 research outputs found

    Fast flickering aurora within traveling current vortices

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    第6回極域科学シンポジウム[OS] 宙空圏11月16日(月) 国立極地研究所1階交流アトリウ

    High sensitivity of an ELISA kit for detection of the gamma-isoform of 14-3-3 proteins: usefulness in laboratory diagnosis of human prion disease

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    <p>Abstract</p> <p>Background</p> <p>The gamma-isoform of the 14-3-3 protein (14-3-3 gamma) is expressed in neurons, and could be a specific marker for neuronal damage. This protein has been reported as a detectable biomarker, especially in the cerebrospinal fluid (CSF) of Creutzfeldt-Jakob disease (CJD) patients by Western blotting (WB) or enzyme-linked immunosorbent assays (ELISAs). Western blotting for 14-3-3 gamma is not sensitive, and the reported data are conflicting among publications. An ELISA specific for 14-3-3 gamma is not available.</p> <p>Methods</p> <p>CJD patients (n = 114 sporadic CJD patients, 7 genetic CJD, and 3 iatrogenic CJD) and 99 patients with other neurodegenerative diseases were examined in this study. The CSF samples obtained were analyzed by Western blotting for 14-3-3 gamma, and by ELISA for total tau protein. We evaluated the sensitivity and specificity of the newly developed sandwich ELISA for 14-3-3 gamma.</p> <p>Results</p> <p>The cut-off value of the 14-3-3 gamma ELISA was > 1, 683 AU/ml; and sensitivity was 95.2%, with 72.7% specificity. This specificity was the same for the total tau protein ELISA. Seven CJD cases were negative by WB but positive using the 14-3-3 gamma ELISA, indicating that the ELISA is more sensitive. All 21 cases of early stage CJD could be diagnosed using a combination of the 14-3-3γ ELISA and diffusion weighted MR imaging (DWI-MRI).</p> <p>Conclusion</p> <p>The 14-3-3 gamma ELISA was more sensitive than conventional WB, and was useful for laboratory diagnosis of CJD, similar to the ELISA for the tau protein. Using DWI-MRI and these ELISA tests on CSF, diagnosis of CJD will be possible even at early stages of the disease.</p

    Neonatal Fc receptor induces intravenous immunoglobulin growth suppression in Langerhans cell histiocytosis

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    The neonatal Fc receptor (FcRn) plays a role in trafficking IgG and albumin and is thought to mediate intravenous immunoglobulin (IVIG) therapy for certain diseases. IVIG can be used for the treatment of human Langerhans cell histiocytosis (LCH); however, the mechanism remains unclear. The expression and function of FcRn protein have not been studied in LCH, though the expression of FcRn messenger RNA (mRNA) have been reported. In this report, we confirmed the expression of FcRn in 26 of 30 pathological cases (86.7%) diagnosed immunohistochemically as LCH. The expression was independent of age, gender, location, multi- or single-system, and the status of BRAFV600E immunostaining. We also confirmed the expression of FcRn mRNA and protein in the human LCH-like cell line, ELD-1. FcRn suppressed albumin consumption and growth of IVIG preparation-treated ELD-1 cells, but not of IVIG preparation-untreated or FcRn-knockdown ELD-1 cells. In addition, FITC-conjugated albumin was taken into Rab11-positive recycle vesicles in mock ELD-1 cells but not in FcRn-knockdown ELD-1 cells. IVIG preparation prolonged this status in mock ELD-1 cells. Therefore, ELD-1 recycled albumin via FcRn and albumin was not used for metabolism. Our results increase our understanding of the molecular mechanism of IVIG treatment of LCH

    Soft Gamma-ray Detector for the ASTRO-H Mission

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    ASTRO-H is the next generation JAXA X-ray satellite, intended to carry instruments with broad energy coverage and exquisite energy resolution. The Soft Gamma-ray Detector (SGD) is one of ASTRO-H instruments and will feature wide energy band (40-600 keV) at a background level 10 times better than the current instruments on orbit. SGD is complimentary to ASTRO-H's Hard X-ray Imager covering the energy range of 5-80 keV. The SGD achieves low background by combining a Compton camera scheme with a narrow field-of-view active shield where Compton kinematics is utilized to reject backgrounds. The Compton camera in the SGD is realized as a hybrid semiconductor detector system which consists of silicon and CdTe (cadmium telluride) sensors. Good energy resolution is afforded by semiconductor sensors, and it results in good background rejection capability due to better constraints on Compton kinematics. Utilization of Compton kinematics also makes the SGD sensitive to the gamma-ray polarization, opening up a new window to study properties of gamma-ray emission processes. The ASTRO-H mission is approved by ISAS/JAXA to proceed to a detailed design phase with an expected launch in 2014. In this paper, we present science drivers and concept of the SGD instrument followed by detailed description of the instrument and expected performance.Comment: 17 pages, 15 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2010: Ultraviolet to Gamma Ray

    Diagnosis of Gastric Cancer in Early Stage — The Clinical Ob­servation of Operated Cases

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    1. An attempt has been made to find the diagnostic criteria for early gastric cancer. It is most important to detect the evidences or suspected features of the malignant growth in incipient stage in order to attain the radical cure by surgical operation. 2. Twelve patients with early gastric cancer (groups A and B) were selected out of 476 patients who had undergone gastrectomy during the past three years in the Okayama Saiseikai General Hospital. The other 6 patients in the &#34;precancerous group&#34; (group C) were also studied, who had abnormal epithelial proliferation in the resected stomach membrane during the same period. 3. The processes of discovery of early cancer have been described. Fairly precise diagnosis can be made in the mucosal carcinoma, but it is not in the ulcer-carcinoma. It was generally difficult to estimate the degree of the malignancy and the extension of the growth preoperatively. 4. The details of the diagnostic aids are as follows. i. Negative occult blood of stool does not always mean the definite diagnostic aid. ii. The malignant gastric change may occur even in non-anacidity. Further investigations should be followed up on gastric ulcer patients if malignant alteration is under the consideration. iii. Minor roentgenological findings, such as the absence or irregularity of mucosal folds, rigid and/or overlapped contour, localized absence or decrease of the peristaltic waves and absence or bow-shaped deformity of the angulus, are of important significance. Such changes should be minutely sought for by X-ray film examination. iv. On gastroscopy and gastrocamera photography, such changes as erosion or irregular granular thickening of the membrane with abnormal reddening and edematous appearance, irregularity of ulcer edge, uneven swelling on ulcer margin with reddening and unsharpness of the edge of adherent coat on ulcer floor, must be noted in the early gastric cancer. v. It is not safe to leave a patient having stomach ulceration under a mere conservative management because it is often quite difficult to dissolve the question of malignancy of the lesion with all sorts of examinations. vi. So far as clinical examinations have indicated malignancy, histological examination must be carried out immediately at the time of operation, even when malignant lesion is absent in inspection and palpation on the exposure of the stomach. vii. On the gross observation of the resected stomach, a particular attention must be paid to erosion, depression or atrophy, irregular granular thickening and abnormal reddening on the restricted areas of the mucosal surface.</p

    Spatial Evolution of Wave‐Particle Interaction Region Deduced From Flash‐Type Auroras and Chorus‐Ray Tracing

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    In-situ observations of spatial variations of the wave-particle interaction region require a large number of satellite probes. As an alternative, flash-type auroras, a kind of pulsating aurora, driven by discrete chorus elements, can be used to investigate the interaction region with a high spatial resolution. We estimated the spatial extent of wave-particle interaction region from ground-based observations of flash aurora at Gakona (62.39°N, 214.78°E), Alaska at subauroral latitudes, and found that the auroral expansion was predominantly to the low-latitude side. The spatial displacement is thought to be caused by the propagation effects of chorus waves in the magnetosphere. Using ray tracing analysis to take into account chorus wave propagation, we reconstructed the spatiotemporal evolution of the volume emission rate and confirmed that the predominant expansion is toward the lower-latitude side in the ionosphere. This study shows that chorus wave propagation in the magnetosphere gives new insight for characterizing the transverse size (across the geomagnetic field line) of wave-particle interaction regions. The calculated spatial scale of the column auroral emission shows a correlation with the magnetic latitude of the resonance region at magnetic latitudes within 10° of the equatorial plane of the magnetosphere. Our results suggest that the spatial scale of a flash aurora is indirectly related to the chorus amplitude because the latitudinal range of the wave-particle interaction is important for the growth of wave amplitude
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