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Y Narumi

Publications and source records attributed to Y Narumi.

At least 19 recordsLinked to original sources
PubMed2006

X-ray diffractometer combining synchrotron radiation and pulsed magnetic fields up to 40 T.

A synchrotron X-ray diffractometer incorporating a pulsed field magnet for high fields up to 40 T has been developed and a detailed description of this instrument is reported. The pulsed field magnet is composed of two coaxial coils with a gap of 3 mm at the mid-plane for passage of the X-rays. The pixel detector PILATUS 100K is used to store the diffracted X-rays. As a test of this instrument, X-ray diffraction by a powder sample of the antiferromagnet CoO is measured below the Néel temperature. A field-dependent lattice distortion of CoO due to magnetostriction is observed up to 38 T.

Journal Article↗
PubMed2004

Effect of prostaglandin E1 on inflammatory responses and gas exchange in patients undergoing surgery for oesophageal cancer.

BACKGROUND: Oesophageal surgery causes morbidity and mortality from respiratory complications. We tested the possibility that prostaglandin E1 (PGE1) could reduce inflammatory cytokine responses and improve gas exchange after oesophagectomy. METHODS: We randomized 14 patients into two groups. One group received PGE1 20 ng kg(-1) min(-1) i.v. during anaesthesia (PGE1 group) and the other group did not (control group). Anaesthesia was maintained with sevoflurane and epidural anaesthesia. During oesophagectomy, ventilation of one lung was carried out with a double-lumen bronchial tube. The patients were extubated on or after the first postoperative day. Blood samples were taken at induction of anaesthesia, at the end of thoracotomy, at the end of the operation, 2 h after surgery and on the first day after surgery. RESULTS: The groups were similar for ASA physical status, age, FEV1%, operation time, duration of thoracotomy, intraoperative fluid volume and blood loss. The arterial blood gas and arterial pressure during surgery were also similar in the PGE1 and control groups. However, the PaO2/FiO2 ratio on the first day after surgery was significantly greater in the PGE1 group compared with the control group. Serum concentrations of IL-6 and IL-8 increased after surgery in both groups. IL-6 was significantly less in the PGE1 group at the end of the operation and 2 h after the operation. CONCLUSIONS: Intraoperative PGE1 reduced IL-6 production in patients undergoing oesophagectomy and oxygenation was better in the postoperative period.

Aged↗
PubMed2001

Characterization of low-intensity lesions in the peripheral zone of prostate on pre-biopsy endorectal coil MR imaging.

The aim of this study was to determine which morphological features of low-intensity lesions in the peripheral zone of the prostate are predictable of prostate cancer on pre-biopsy T2-weighted integrated endorectal phased-array MR images. The MR examinations were performed in 69 consecutive patients with elevated level of prostate-specific antigen (>4 ng/ml) and/or a positive digital rectal examination before transperineal 12-site biopsy. Two radiologists evaluated presence of lesions, their morphological features, and possibility of malignancy in divided into four sections of the peripheral zone. Imaging analysis findings were compared with biopsy results. Discriminative features were selected by stepwise logistic regression. Descriptive statistics and receiver operating characteristics (ROC) curves were also calculated. Sixty-eight benign lesions and 23 malignant lesions were found. Wedge shape and diffuse extensions without mass effect were significantly associated with benignity ( P=0.0105 and 0.002, respectively). Lesion size was significantly associated with malignancy ( P=0.0001). For evaluating probability of malignancy for lesions, regression model showed a comparable accuracy with the total impression for the readers in ROC analysis (Az 0.9095 vs 0.9266, respectively). Wedge shape, diffuse extension without mass effect, and size are the morphological features of low-intensity lesions in the peripheral zone on pre-biopsy T2-weighted MR images that give the best prediction of malignancy.

Aged↗
PubMed2001

Evidence for the singlet-dimer ground state in an S = 1 antiferromagnetic bond alternating chain.

Susceptibility, ESR, and magnetization measurements have been performed on single crystals of an S = 1 bond alternating chain compound: [Ni(333-tet) (mu-NO2)] (ClO4) (333-tet = N,N'-bis(3-aminopropyl)propane-1,3-diamine) and the compound doped with a small amount of Zn. We observed an anomalous angular dependence in the Zn-doped sample. These results are well explained by the model based on the valence-bond solid picture for the singlet-dimer phase. The picture implies that the free spins of S = 1 with a positive uniaxial single-ion anisotropy are induced at the edges of the chains without forming the singlet dimer.

Journal Article↗
PubMed2001

Changes of cytokines in direct endotoxin adsorption treatment on postoperative multiple organ failure.

Multiple organ failure (MOF) is a serious condition that involves simultaneous or consecutive functional failure of several important organs. Furthermore, sepsis is known to play an important role in the occurrence of MOF. Hemoadsorption therapy with the endotoxin adsorption column containing polymyxin B immobilized fibers by direct hemoperfusion (PMX-DHP) is reportedly effective in the treatment of septic shock. This study examined the changes induced on cytokines upon PMX-DHP treatment in 25 patients who underwent emergency abdominal surgery and were immediately started on a postoperative regimen of continuous hemodiafiltration (CHDF) and PMX-DHP. Postoperative MOF was observed in these patients with a mean APACHE II SCORE of 25.5. Eighty percent of patients survived for more than 1 month. We were able to reduce the necessary dose of dopamine in 85.7% of patients because hemodynamic stability improved after administration of PMX-DHP. Interleukin 6 blood levels did not change significantly before or after PMX-DHP treatment in either the surviving or nonsurviving patients. Blood interleukin 1 receptor antagonist levels decreased in both groups. Intercellular adhesion molecular-1, NOx, and thrombomodulin did not change significantly during the course of treatment in either group. Decreased blood levels of PAI-1 levels were found in the surviving patients whereas increased levels of PAI-1 were found in the non-surviving patients. In conclusion, PMX-DHP treatment may be limited clinically in its ability to remove inflammatory cytokines and humoral mediators. However, PMX-DHP treatment is useful for hemodynamic stabilization, which prevents development of MOF.

APACHE↗
PubMed2001

PACS linked to EPR.

We developed a new PACS linked to Electronic Patient Record system (EPR). It was a hospital-wide PACS storing all the radiological examinations. The images and reports were linked on EPR. The concept of navigation servers and segment servers was introduced for prefetchig and quick displaying. After the start of operation, increasing retrieval indicated its effectiveness on practical work in spite of remaining delivery of radiographs.

Computer Communication Networks↗
PubMed2000

Multishot echo-planar imaging with gadopentetate dimeglumine. Preliminary study of efficacy for detection of hypovascular metastatic liver tumors.

OBJECTIVE: To evaluate the usefulness of sequential T2-weighted spin-echo type multishot echo-planar (T2-EP) imaging with gadopentetate dimeglumine for the detection of hypovascular metastatic liver tumors. MATERIAL AND METHODS: Fifteen consecutive patients with 56 proven hypovascular metastatic liver tumors were included in the study. Three observers blindly and independently read the whole-liver images obtained with T2-weighted spin-echo, T2-weighted single-shot fast spin-echo, T1-weighted fast multiplanar spoiled GRASS and T2-EP images obtained before and 25, 60, 90 and 120 s after injection of 0.2 mmol/kg b.w. of gadopentetate dimeglumine. The diagnostic accuracy was estimated by calculating the area under the observer-specific binomial receiver operating characteristics curves (Az). RESULTS: T2-EP images obtained 60 s after contrast injection showed significantly higher contrast-to-noise (C/N) ratios than the other imaging techniques. A combination of all phases of the T2-EP images produced the highest sensitivity and specificity. In terms of the Az value, the diagnostic accuracy for tumor detection achieved with a combination of all phases of the T2-EP images was significantly higher than that with T1-SPGR and T2-SSFSE images (p<0.01). The Az values of the T2-EP images (Az=0.975) were higher than those of T2-CSE images (Az=0.948), but the difference was not significant. CONCLUSION: Our preliminary study revealed that sequential imaging with enhanced T2-EP images was useful for the detection of hypovascular metastatic liver tumors because of its superior C/N ratio and sensitivity.

Adult↗
PubMed2000

Transition zone biopsy in the detection of prostate cancer.

OBJECTIVE: About 25% of all prostate cancers occur in the transition zone (TZ). We analyzed the impact of 4 systematic TZ and 2 systematic apex (AP) biopsies in addition to systematic sextant biopsies in an effort to establish the diagnostic importance of early prostate cancer. METHODS: One hundred and thirty patients underwent systematic transperineal multipoint prostate biopsy (biopsy of 12 sites, including 4 TZ and 2 AP biopsies). RESULTS: Forty-one of 130 men (31.5%) had biopsy specimens positive for cancer, and cancer originated in the TZ alone in 4 of these 41 patients (9.8%). Fourteen patients underwent radical retropubic prostatectomy. We compare the pathological findings of radical prostatectomy specimens and biopsy results. Prostate cancers predicted to be stage T(2c) by TZ biopsy were all classified as pT(2c) or greater. CONCLUSIONS: Routine TZ biopsy does not substantially increase the prostate cancer detection rate; however, it can be useful in patients who require repeat biopsy.

Aged↗
PubMed2000

[Staging urinary bladder cancer with dynamic MR imaging].

This article reviews the magnetic resonance (MR) staging of bladder cancer. The multiplanar and soft-tissue characterization capabilities of MR imaging make it a valuable diagnostic tool to image the urinary bladder. Recent advances of MR imaging such as fast imaging, pelvic phased array coil, and dynamic imaging improve the image quality and diagnostic accuracy for staging bladder cancer. Some patient-related factors are also important for optimal imaging of the urinary bladder, especially motion artifacts from the gastrointestinal tract and the degree of bladder distension. An anticholinergic agent should be used for suppressing the motion artifacts. Optimal bladder filling can be achieved by asking patients to void and drink water 1 hour before examinations. Scanning perpendicular to the bladder wall is necessary for optimal evaluation for staging bladder cancer. Oblique scanning is needed in cases when a tumor is not located on the dome, base, anterior wall, posterior wall, or lateral walls. The early phase image of dynamic imaging is most useful for staging tumors. Better contrast between tumor and bladder wall on dynamic images provides high staging accuracy, especially in differentiation between superficial tumors and tumors with muscle invasion. MR imaging is comparable to computed tomography (CT) in the evaluation of lymph nodes. Although MR imaging currently is not appropriate for screening for bladder cancer and detecting small tumors, it has been proved to be most useful in the staging of bladder cancer.

Artifacts↗
PubMed1999

MR imaging of non-squamous vaginal tumors.

We reviewed the MR images and pathologic findings of five cases of primary vaginal neoplasms of non-squamous origin. Histologic types consisted one case each of adenocarcinoma, adenosarcoma, melanoma, lymphoma, and neurilemoma. Magnetic resonance imaging was found useful for evaluating the type and the extension of vaginal tumors.

Adult↗