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排序方式: 共有483条查询结果,搜索用时 15 毫秒
1.
Shinji Naganawa Rintaro Ito Hisashi Kawai Toshiaki Taoka Tadao Yoshida Michihiko Sone 《Magnetic resonance in medical sciences》2020,19(4):375
Purpose:It has been reported previously that intravenously administered gadolinium-based contrast agent (GBCA) leaks into the subarachnoid space around the cortical veins at 4 h after injection in all old people over 37 years, but not in younger people up to 37 years of age in 3D-real IR images. The purpose of this study was to investigate whether there was a strict threshold of 37 years of age for the leakage of the GBCA into the subarachnoid space.Methods:The subjects included 190 patients, that were scanned for 3D-real IR images at 4 hours after intravenous injection of GBCA as a diagnostic test for endolymphatic hydrops. The patient’s age ranged from 14 to 81 years. Two experienced neuroradiologists evaluated the images to determine whether the GBCA leakage around the cortical veins was positive or negative. Any discrepancies between the two observers were discussed and a consensus was obtained.A Mann–Whitney U test and receiver operating characteristic (ROC) curve analysis were used to compare the positive and the negative group and to set the age cut-off value for the prediction of GBCA leakage.Results:The GBCA leakage around the cortical veins was negative in 35 patients and positive in 155 patients. The average age was 33 ± 11 years in the negative group, and 55 ± 12 years in the positive group (P < 0.01). In the ROC analysis for the age and leakage of the GBCA, an area under the curve was 0.905 and the cut-off age was 37.317 years (sensitivity of 0.942 and specificity of 0.771).Conclusion:Intravenously administered GBCA leaks into the subarachnoid space around the cortical veins in most patients over 37 years of age. However, it should be noted that it can be found occasionally in patients under 37 years of age. 相似文献
2.
3.
Itoh K Naganawa Y Matsuzawa F Aikawa S Doi H Sasagasako N Yamada T Kira J Kobayashi T Pshezhetsky AV Sakuraba H 《Journal of human genetics》2002,47(1):29-37
Three novel missense mutations in the human lysosomal sialidase gene causing amino acid substitutions (P80L, W240R, and P316S)
in the coding region were identified in two Japanese sialidosis patients. One patient with a severe, congenital form of type
2 sialidosis was a compound heterozygote for 239C-to-T (P80L) and 718T-to-C (W240R). The other patient with a mild juvenile-onset
phenotype (type 1) was a homozygote for the base substitution of 946C-to-T (P316S). None of these mutant cDNA products showed
enzymatic activity toward an artificial substrate when coexpressed in galactosialidosis fibroblastic cells together with protective
protein/cathepsin A (PPCA). All mutants showed a reticular immunofluorescence distribution when coexpressed with the PPCA gene in COS-1 cells, suggesting that the gene products were retained in the endoplasmic reticulum/Golgi area or rapidly degraded
in the lysosomes. Homology modeling of the structural changes introduced by the mutations predicted that the P80L and P316S
transversions cause large conformational changes including the active site residues responsible for binding the sialic acid
carboxylate group. The W240R substitution was deduced to influence the molecular surface structure of a limited region of
the constructed models, which was also influenced by previously identified V217M and G243R transversions.
Received: Stptember 21, 2001 / Accepted: November 2, 2001 相似文献
4.
MR imaging of the cochlear modiolus: area measurement in healthy subjects and in patients with a large endolymphatic duct and sac 总被引:6,自引:0,他引:6
Naganawa S Ito T Iwayama E Fukatsu H Ishigaki T Nakashima T Ichinose N 《Radiology》1999,213(3):819-823
PURPOSE: To evaluate the cochlear modiolus with thin-section magnetic resonance (MR) imaging in healthy subjects and patients with a large endolymphatic duct and sac, and to assess whether the cochlea is normal or abnormal in patients with a large endolymphatic duct and sac. MATERIALS AND METHODS: MR images were obtained in 10 ears in five volunteers (group 1), 40 ears in 20 patients with bilateral sensory hearing loss (group 2), three ears in two patients with Mondini malformation (group 3), and 12 ears in seven patients with a large endolymphatic duct and sac (group 4). RESULTS: In groups 1 and 2, all modiolar areas were larger than 4.0 mm2. In group 3, each modiolus was smaller than 2.0 mm2. In group 4, modiolar areas were smaller than 2.0 mm2 in eight ears and were larger than 4.0 mm2 in four ears. CONCLUSION: Findings in this study confirm that a large endolymphatic duct and sac is frequently associated with modiolar deficiency, but the modiolar area is normal in some cases. This result does not support the recently proposed hypothesis that hearing loss with a large endolymphatic duct and sac is caused by the transmission of subarachnoid pressure forces into the labyrinth through a deficient modiolus. 相似文献
5.
N Matsumoto T Tsuchida H Nakamura R Sawa Y Takahashi H Naganawa H Iinuma T Sawa T Takeuchi M Shiro 《The Journal of antibiotics》1999,52(3):276-280
The absolute structure of a new antibiotic lactonamycin is described. The NMR studies deduced one of four possible structures for the aglycon attached by a rhodinose through glycosidic bond. The stereochemistry of the sugar obtained by an acid hydrolysis was determined to be L-form by measuring optical rotation. The stereochemistry of the aglycon was determined by X-ray crystallographic analysis. 相似文献
6.
Igarashi M Shida T Sasaki Y Kinoshita N Naganawa H Hamada M Takeuchi T 《The Journal of antibiotics》1999,52(10):873-879
A new depsipeptide antibiotic, vinylamycin, was isolated from the culture broth of an actinomycete strain. The producing organism, designated MI982-63F1, was identified as a member of Streptomyces. Vinylamycin was isolated from the culture broth by extraction with EtOAc and purified by crystallization from EtOAc. The structure of vinylamycin was determined by spectroscopic analysis and degradation studies. Vinylamycin showed antimicrobial activities against Gram-positive bacteria including MRSA. 相似文献
7.
The biosynthesis of benastatin A, produced by Streptomyces sp. MI384-DF12, has been studied by feeding experiments with 14C- and 13C-labeled compounds followed by measurement of radioactivity and 13C NMR analysis. The results indicate that benastatin A is derived from two methionine units and fourteen acetate units, condensed in the "head-to-tail" fashion of typical polyketide biosynthesis. 相似文献
8.
Shibahara E Fukatsu H Naganawa S Ito T Iwayama E Ishigaki T Segawa T Zhang W 《Nagoya journal of medical science》2000,63(1-2):41-49
In this paper, we tried to evaluate the effect of water-fat separation on and to optimize the scan condition of the newly developed "Sandwiched" 3-point Dixon method at 0.35 Tesla (T), for knee joint imaging. Using a 0.35T superconductive open magnet system with a solenoid type knee coil, one male and two female normal volunteers (27-37 y.o.) underwent knee joint imaging. Each sequence provided good water-fat separated images. At 0.35T, the gradient echo provided a better contrast than the spin echo. Optimal cartilage-marrow and cartilage-fluid contrast could be obtained at a frip angle (FA) of 90 degrees. There was no significant correlation between cartilage-marrow, cartilage-fluid contrast and repetition time (TR) values within the tested range. Cartilage-fluid and cartilage-marrow contrast were both best at an FA of 90 degrees with the gradient echo sequence. TR from 350 ms to 650 ms did not cause any significant contrast difference in the fat suppressed images. This method is useful and could be the only practical choice for obtaining fat suppressed T1 weighted images for joint magnetic resonance (MR) imaging at 0.35T. 相似文献
9.
Akira Takada Kojiro Suzuki Yoshine Mori Ryota Hyodo Kenichi Kawakami Yoshiyuki Okochi Shinji Naganawa 《Journal of vascular and interventional radiology : JVIR》2013,24(4):550-557
PurposeTo compare left adrenal venous sampling (AVS) in two locations: the central adrenal vein and the common trunk.Materials and MethodsA total of 22 patients (12 men and 10 women; mean age, 50 y; range, 26–65 y) who were suspected of having primary aldosteronism (PA) and underwent successful AVS with cortisol concentration measurement and/or venography between November 2010 and August 2011 were retrospectively analyzed. In regard to the left adrenal vein, collections were done at two locations: at the common trunk below the confluence of the inferior phrenic vein and at the central adrenal vein, which was above the confluence. The effects of the inflow from the inferior phrenic vein on plasma aldosterone and cortisol levels were analyzed.ResultsEight patients had bilateral hypersecreting lesions and 13 had a unilateral lesion. One was diagnosed as having secondary hypertension other than PA. The median cortisol levels below and above the confluence were 129 μg/dL (range, 21–400 μg/dL) and 215 μg/dL (range, 21–690 μg/dL), respectively. The median aldosterone levels were 2,120 pg/mL (range, 164–42,700 pg/mL) and 4,275 pg/mL (range, 119–59,000 pg/mL), respectively. The median aldosterone/cortisol (A/C) ratios were 244 (range, 34–2,401) and 278 (range, 25–2,251), respectively. Cortisol and aldosterone levels were significantly higher above the confluence (P = .0050 and P = .0003, respectively), whereas the A/C ratio showed no significant difference (P = .12).ConclusionsAlthough higher levels of cortisol and aldosterone were obtained upstream, A/C ratio was not significantly different between the central adrenal vein and the common trunk. 相似文献
10.
La radiologia medica - Thus far, ultrasound, CT, and 2D cine phase-contrast MRI has been adopted to evaluate blood flow and vascular morphology in the portal venous system; however, all these... 相似文献