201 research outputs found

    Hepatic Angiomyolipoma with Minimal Intratumoral Fat Content

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    We report a rare case of hepatic angiomyolipoma with minimal fat content. The low fat content led to an incorrect preoperative diagnosis. A 38-year-old man who was a carrier of hepatitis B virus infection incidentally presented with a hepatic tumor. His serum alpha-fetoprotein level was normal. Ultrasonography revealed a well-circumscribed, heterogeneous hypoechoic nonencapsulated liver tumor measuring 34 × 24 mm. Precontrast computed tomography (CT) did not reveal fatty attenuation in the lesion. Contrast-enhanced CT revealed a hypervascular nonencapsulated tumor in the arterial phase and moderate washing out of the contrast medium in the portal phase. A hypervascular tumor was observed on CT hepatic arteriography, and complete washing out of the contrast medium on CT during arterial portography. These findings are compatible with hepatocellular carcinoma. The tumor exhibited low signal intensity on T1-weighted images and high signal intensity on T2-weighted images; no hypointensity was observed on fat suppression images. The patient underwent left hemihepatectomy because of a preoperative diagnosis of hepatocellular carcinoma. The histopathological diagnosis was a hepatic angiomyolipoma with 5% fat content. Low fat content makes the diagnosis of this condition difficult. The absence of serum tumor markers and the presence of a nonencapsulated hypervascular tumor may facilitate the accurate preoperative diagnosis of hepatic angiomyolipomas that have a low fat content and mimic hepatocellular carcinoma

    Donor-specific tolerance induced by simultaneous allogeneic islet transplantation with CD4+CD25+ T-cells into hepatic parenchyma in mice

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    Background. The allogeneic islets transplantation is an ideal therapeutic strategy for patients with diabetes mellitus. However, it has been difficult to induce immunological tolerance against islets grafts. TheCD4+CD25+ regulatory T-cells (Treg) play a role in suppressing T-cell activation. Thus, we evaluated whether Treg can regulate donor-specific T-cell tolerance that received allogeneic islets into the hepatic parenchyma (ITxHP) along with Treg. Methods. C3H/He mice were used as donors and streptozotocin-induced diabetic BALB/c mice were recipients. The protocol included three groups : Group A recipients received only 300 IE islets Group B was given 300 IE islets and whole splenocytes Group C was given 300 IE islets and Treg purified from peripheral lymph nodes. Results. For all mice in Groups A and B, the fasting blood sugar exceeded 250mg/dl and graft rejection was observed. GVHD was observed earlier in Group B than in Group A. In contrast graft survival exceeded 30 days for two mice in Group C (50%, mean POD 28.5±24.0, Plt0.05). Mixed lymphocyte reaction showed that T-cells from tolerant mice had very weak responses against spleen cells from C3H mice. Conclusions. The simultaneous ITxHP with CD4+CD25+ T-cells administration prolonged islet graft survivals and induced donor-specific hyporesposiveness

    The effect of continuous arterial infusion of Gabexate Mesilate (FOY-007) on experimental acute pancreatitis

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    The effectiveness of continuous arterial infusion of Gabexate Mesilate (FOY-007) on experimental acute pancreatitis was investigated. Acute necrotizing pancreatitis was induced by an injection of 10% Na-taurocholate (1ml/kg) into the main pancreatic duct of mongrel dogs. Animals were divided into three groups Group A: non-treated control, Group B: after the induction of pancreatitis, injected with FOY-007 intravenously (5mg/kg/hr), Group C: after the induction of pancreatitis, injectedwithFOY-007 via the celiac artery. The changes in the values of amylase and lipase in serum and ascites etc. were examined. A histological examination was done and the FOY-007 concentration of the pancreas was measured. In both groups B and C, the serum levels of amylase and lipase reached significantly to low levels compared with those in group A. The extents of pancreatic parenchyma necrosis in each group were 36.1, 25.3 and 19.5% , respectively, and were significantly improved in group C. In addition, theFOY-007levels in pancreas specimens in the intraarterial infusion group exceeded those in the intravenous infusion group by 32 times. The results suggest that continuous FOY-007 arterial infusion therapy is useful as a local treatment for severe acute pancreatitis

    Long-Term Density Trend in the Mesosphere and Lower Thermosphere from Occultations of the Crab Nebula with X-Ray Astronomy Satellites

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    We present long-term density trends of the Earth's upper atmosphere at altitudes between 71 and 116 km, based on atmospheric occultations of the Crab Nebula observed with X-ray astronomy satellites, ASCA, RXTE, Suzaku, NuSTAR, and Hitomi. The combination of the five satellites provides a time period of 28 yr from 1994 to 2022. To suppress seasonal and latitudinal variations, we concentrate on the data taken in autumn (49< doy <111) and spring (235< doy <297) in the northern hemisphere with latitudes of 0--40 degrees. With this constraint, local times are automatically limited either around noon or midnight. We obtain four sets (two seasons times two local times) of density trends at each altitude layer. We take into account variations due to a linear trend and the 11-yr solar cycle using linear regression techniques. Because we do not see significant differences among the four trends, we combine them to provide a single vertical profile of trend slopes. We find a negative density trend of roughly -5 %/decade at every altitude. This is in reasonable agreement with inferences from settling rate of the upper atmosphere. In the 100--110 km altitude, we found an exceptionally high density decline of about -12 %/decade. This peak may be the first observational evidence for strong cooling due to water vapor and ozone near 110 km, which was first identified in a numerical simulation by Akmaev et al. (2006). Further observations and numerical simulations with suitable input parameters are needed to establish this feature.Comment: 38 pages, 9 figures, accepted for publication in Journal of Geophysical Research - Space Physic

    Optimal Location of Two Laser-interferometric Detectors for Gravitational Wave Backgrounds at 100 MHz

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    Recently, observational searches for gravitational wave background (GWB) have been developed and given constraints on the energy density of GWB in a broad range of frequencies. These constraints have already resulted in the rejection of some theoretical models of relatively large GWB spectra. However, at 100 MHz, there is no strict upper limit from direct observation, though an indirect limit exists due to He4 abundance due to big-bang nucleosynthesis. In our previous paper, we investigated the detector designs that can effectively respond to GW at high frequencies, where the wavelength of GW is comparable to the size of a detector, and found that the configuration, a so-called synchronous-recycling interferometer is best at these sensitivity. In this paper, we investigated the optimal location of two synchronous-recycling interferometers and derived their cross-correlation sensitivity to GWB. We found that the sensitivity is nearly optimized and hardly changed if two coaligned detectors are located within a range 0.2 m, and that the sensitivity achievable in an experiment is far below compared with the constraint previously obtained in experiments.Comment: 17 pages, 6 figure

    A molecular dynamics simulation of polymer crystallization from oriented amorphous state

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    Molecular process of crystallization from an oriented amorphous state was reproduced by molecular dynamics simulation for a realistic polyethylene model. Initial oriented amorphous state was obtained by uniaxial drawing an isotropic glassy state at 100 K. By the temperature jump from 100 K to 330 K, there occurred the crystallization into the fiber structure, during the process of which we observed the developments of various order parameters. The real space image and its Fourier transform revealed that a hexagonally ordered domain was initially formed, and then highly ordered crystalline state with stacked lamellae developed after further adjustment of the relative heights of the chains along their axes.Comment: 4 pages, 3 figure

    Testing the External Shock Model of Gamma-Ray Bursts using the Late-Time Simultaneous Optical and X-ray Afterglows

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    We study the ``normal'' decay phase of the X-ray afterglows of gamma-ray bursts (GRBs), which follows the shallow decay phase, using the events simultaneously observed in the R-band. The classical external shock model -- in which neither the delayed energy injection nor time-dependency of shock micro-physics is considered -- shows that the decay indices of the X-ray and R-band light curves, αX\alpha_{\rm X} and αO\alpha_{\rm O}, obey a certain relation, and that in particular, αOαX\alpha_{\rm O}-\alpha_{\rm X} should be larger than -1/4 unless the ambient density increases with the distance from the central engine. For our selected 14 samples, we have found that 4 events violate the limit at more than the 3σ\sigma level, so that a fraction of events are outliers of the classical external shock model at the ``normal'' decay phase.Comment: Accepted for publication in ApJL. 12 page, 2 figures, 2 table

    Genetic population structure of Hemigrammocypris rasborella (Cyprinidae) inferred from mtDNA sequences

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    The genetic population structure of the small cyprinid Hemigrammocypris rasborella, distributed widely in lowlands of western Japan, was examined using partial sequence data of mitochondrial DNA (mtDNA). Molecular phylogenetic analysis revealed that the populations of the western Kyushu region were markedly differentiated from all eastern populations, such that the groups would be comparable to different species; their divergence was inferred to have occurred in the Late Miocene–Pliocene. Also, a largely divergent mtDNA group (with divergence in the early Pleistocene) was found in the Sanyo and northeastern Shikoku regions, forming a secondary contact zone in the western Kinki with the eastern mtDNA group. To date, these aspects of the population structure of H. rasborella appear to be unique among lowland fishes in western Japan. Deeper understanding of the formation processes of freshwater faunas in western Japan will require further comparisons of the phylogeographic patterns and ecological traits of constituent species
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