Publications by authors named "Oyama N"

Purpose: To evaluate the speed and precision of split renal volume (SRV) measurement, which is the ratio of unilateral renal volume to bilateral renal volume, using a newly developed software for computed tomographic (CT) volumetry and to investigate the usefulness of SRV for the estimation of split renal function (SRF) in kidney donors.

Method: Both dynamic CT and renal scintigraphy in 28 adult potential living renal donors were the subjects of this study. We calculated SRV using the newly developed volumetric software built into a PACS viewer (n-SRV), and compared it with SRV calculated using a conventional workstation, ZIOSOFT (z-SRV).

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Purpose: In the present study, we used animal models to investigate whether the selective α(1A)-blocker silodosin exerts inhibitory effects on detrusor overactivity by modulating C-fiber afferent activity.

Methods: To desensitize C-fiber afferents, 0.3 mg/kg of resiniferatoxin (RTX) was subcutaneously injected into some female Sprague-Dawley rats 2 days before creation of each model.

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The role of electron cyclotron resonance heating (ECRH) on the toroidal rotation velocity profile has been investigated in the JT-60U tokamak device by separating the effects of the change in momentum transport, the intrinsic rotation by pressure gradient, and the intrinsic rotation by ECRH. It is found that ECRH increases the toroidal momentum diffusivity and the convection velocity. It is also found that ECRH drives the codirection (co) intrinsic rotation inside the EC deposition radius and the counterdirection (ctr) intrinsic rotation outside the EC deposition radius.

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A 63-year-old man who was involved in a traffic accident was transferred to our hospital. He was unconscious and had a flail chest. On chest X-ray, he had a left hemopneumothorax and multiple rib fractures.

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We have observed a bursting mode in the high-beta plasmas above the ideal beta limit without a conducting wall. The mode frequency is chirping down as the mode amplitude increases, and its initial value is close to the precession frequency of the trapped energetic particle from the perpendicular neutral beams. The mode structure is radially extended with a peak around the q = 2 surface.

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Article Synopsis
  • Researchers diagnosed an unroofed coronary sinus before surgery using 3D volume rendering and endocardial views from 64-slice MDCT imaging.
  • The imaging clearly highlighted the defect in the coronary sinus roof and its relation to nearby structures.
  • MDCT is an effective non-invasive method for assessing unroofed coronary sinus, making it valuable for planning surgeries.
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Page kidney is caused by the accumulation of blood in the perinephric or subcapsular space, resulting in compression of the involved kidney, renal ischemia and high renin hypertension. We describe a case of domestic violence-related Page kidney. This report also reviews previously described cases of Page kidney.

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We present a case of hepatoid carcinoma of the abdominal skin in a male Wistar rat. Histopathologically, this carcinoma resembled human hepatocellular carcinoma with respect to trabecular-sinusoidal structures. Carcinoma tissues contain numerous eosinophilic globules and crystals, and in this case, we found the characteristic eosinophilic globules in the hepatoid carcinoma cells and the crystals in the extracellular portions.

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Background: Notch1 regulates binary cell fate determination and is critical for angiogenesis and cardiovascular development. However, the pathophysiological role of Notch1 in the postnatal period is not known. We hypothesize that Notch1 signaling in vascular smooth muscle cells (SMCs) may contribute to neointimal formation after vascular injury.

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Lowering the blood pressure (BP) during the acute period following ischemic stroke is still a controversial treatment. In this study, we investigated the effect of postischemic treatment using the angiotensin II type 1 receptor blocker, candesartan, on brain damage in focal cerebral ischemia. Spontaneously hypertensive rats underwent transient occlusion of the middle cerebral artery for 1 h.

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Purpose: To evaluate the feasibility of shortening the bed rest time from 4 hours to 2 hours after transfemoral noncardiac angiography with a 4-F sheath (outer diameter, 1.93 mm), a 5-F sheath (outer diameter, 2.27 mm), and a 4-F catheter.

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The extracellular matrix protein 1 (ECM1) is an 85 kDa secreted glycoprotein, comprising four variants and playing a pivotal role in endochondral bone formation, angiogenesis, and tumour biology. A computational model for the three-dimensional structure of ECM1a was determined to identify the potential and/or concealed region(s) for binding with candidate partners in human skin. Multiple alignments for the secondary structure of ECM1a and b revealed similarity with serum albumin.

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We report a rare case of multiple myeloma that developed extramedullary plasmacytoma at the hilus of the liver causing obstructive jaundice. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsy was quite useful in the diagnosis. A 71-year-old man was diagnosed with stage IIIA multiple myeloma in June 2007 based on osteolytic lesions, increased atypical plasma cells in the bone marrow, and monoclonal (M) protein of IgA-lambda, IgG-lambda, BJP-lambda type.

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The secondary skin malignancies arising in seborrheic keratosis (SK) are uncommon, and the causal association between the pre-existing lesion and subsequent malignant transformation remains uncertain. Among these enigmatic conditions, trichilemmal differentiation and/or neoplasms in SK have rarely been reported thus far. Herein, we describe a case of invasive trichilemmal carcinoma arising in a long-standing SK of the abdominal skin, and clinicopathologically review this rare complication with a computerized medical published work search (PubMed) and citations from earlier reports.

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Motional Stark effect (MSE) diagnostics in JT-60U works as polarimeter to measure the pitch angle of magnetic field as well as beam-emission-spectroscopy (BES) monochromator simultaneously at 30 spatial channels. Fluctuation in the BES signal using MSE optics (MSE/BES) contains fluctuations in not only the density but also the pitch angle (or the magnetic field). Correlation analysis of the magnetic fluctuation between two spatial channels is applied to high-beta plasma with a magnetohydrodynamic activity at frequency of about 0.

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Purpose: In this study, we investigated the effectiveness of positron emission tomography (PET) with (11)C-acetate (AC) for evaluation of renal cell carcinoma.

Methods: Enrolled in the study were 20 patients with suspected renal tumour, one of whom had three renal lesions. In all, 22 renal lesions were evaluated.

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Dodecanoyl amidoalkylguanidine hydrochlorides (C(12)A(m)G, m = 2, 3, 4, 6) are cationic surfactants that have an amidoalkyl group (A(m)) as spacer between the cationic guanidine and hydrophobic groups in the molecule. The effect of the A(m) group on the aggregation properties of the surfactants was evaluated through measurements of their critical micelle concentration (cmc) value, Krafft point, phase behavior, area occupied by one molecule at the air/water interface, and micellar aggregation number. Dodecylguanidine hydrochloride (C(12)A(0)G) with no A(m) group is a unique cationic surfactant because it exhibits a strong tendency for self-assembly when compared with common ionic surfactants, due to the hydrogen bonding between its guanidine groups in addition to the hydrophobic interaction between its alkyl chains [M.

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A spontaneous transition phenomena between two states of a plasma with an internal transport barrier (ITB) is observed in the steady-state phase of the magnetic shear in the negative magnetic shear plasma in the JT-60U tokamak. These two ITB states are characterized by different profiles of the second radial derivative of the ion temperature inside the ITB region (one has a weak concave shape and the other has a strong convex shape) and by different degrees of sharpness of the interfaces between the L mode and the ITB region, which is determined by the turbulence penetration into the ITB region.

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Behçet's disease (BD) is still considered as a mysterious multisystemic disorder characterized by recurrent involvement of muco-cutaneous, ocular, intestinal, vascular and/or nervous system organs. In this review, we would like to highlight and discuss several important advances in our understanding of the pathogenesis of BD based on the intrinsic genetic factors including HLA-B51 and MICA expression and extrinsic triggering factors. As one of the extrinsic triggering factors, we focused on the hypersensitivity against oral streptococci which might be acquired through the innate immune mechanism.

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The pathophysiology in the development of overactive bladder syndrome (OAB) possibly due to benign prostatic hyperplasia (BPH) has not fully been understood. The clinical study in male outpatients aged over 50 years with lower urinary tract symptoms showed that the frequency of urgency was significantly associated with aging, bladder outlet obstruction (BOO) and benign prostatic enlargement (BPE). From the results of the experiments we did using rats, the mechanisms underlying the development of OAB were suggested as follows.

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Self-assembling characteristics of dodecylguanidine hydrochloride (C 12G), a cationic surfactant with a guanidine group in its molecule, were investigated and compared with those of dodecyltrimethylammonium chloride (DTAC) and sodium dodecylsulfate (SDS). Introduction of a guanidine group into the surfactant molecule was found to increase its assembly formability more than that of the trimethylammonium group on the basis of the experimental results on the phase diagram, Kraft point, area occupied per molecule at the air-water interface, and micellar aggregation number of C 12G. Thermodynamic parameters for micelle formation suggested that an attractive force acts between guanidine groups of C 12G molecules to facilitate their assembly formation.

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Objectives: Although invasive and expensive, the pressure-flow study is known as the reference standard for the diagnosis of bladder outlet obstruction. We investigated the usefulness of ultrasound-estimated bladder weight (UEBW) as a predictor of the need for surgery for benign prostatic hyperplasia (BPH).

Methods: A total of 97 consecutive male patients >50 years old with lower urinary tract symptoms (LUTS) were prospectively enrolled in this study.

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