Search PubMed⌕ Search

Biomedical subjects

T Kumazaki

Publications and source records attributed to T Kumazaki.

At least 73 records · Page 4Linked to original sources
PubMed1998

Acute traumatic injury of the distal descending aorta associated with thoracic spine injury.

A rare case of traumatic injury of the distal descending aorta associated with thoracic spine injury is reported. A 21-year-old man was admitted after a traffic accident. Thoracic CT and angiography demonstrated a false aneurysm of the distal descending aorta and a compression fracture of the eleventh thoracic vertebra. At emergency surgery, a transverse linear tear at the level of the aortic hiatus was confirmed and repaired.

Accidents, Traffic↗
PubMed1998

Mesenteric schwannoma.

Schwannoma is a benign neurogenic tumor arising from the sheath of peripheral nerves. It occurs very rarely in the mesentery, where it is difficult to diagnose. Herein we describe a case in which contrast-enhanced CT and gadolinium-DTPA-enhanced MR showed a locally enhanced well-defined tumor with a cystic component just anterior to the duodenum. These findings corresponded well to the resected specimen.

Contrast Media↗
PubMed1998

Primary leiomyoma of the ovary: a case report.

The imaging features of primary ovarian leiomyoma have seldom been described because of the very low prevalence of the tumor. Herein we present a case report on its magnetic resonance imaging features. Both T1- and T2-weighted images revealed a low-signal-intensity mass, which was well circumscribed and sharply demarcated from the uterus. Magnetic resonance imaging was useful in distinguishing it from a malignant ovarian tumor and uterine leiomyoma.

Diagnosis, Differential↗
PubMed1998

Effect of iodixanol on renal function immediately after abdominal angiography. Clinical comparison with iomeprol and ioxaglate.

PURPOSE: To investigate the acute renal effects of three contrast media in a double-blind randomized parallel-group study. The contrast media investigated were: the nonionic dimeric iso-osmolality medium iodixanol; the nonionic monomeric medium iomeprol; and the ionic dimeric medium ioxaglate. MATERIAL AND METHODS: A total of 30 patients were given the following doses of contrast medium: 10 patients received iodixanol 320 mg I/ml; 10 received iomeprol 300 mg I/ml; and 10 received ioxaglate 320 mg I/ml. The doses were given intra-arterially at routine abdominal angiography and the renal effects of these three contrast media were studied for up to 120 min after injection. RESULTS: The urinary minute volume increased immediately after angiography but tended to return to baseline values after 120 min; these changes were more pronounced with iomeprol and ioxaglate than with iodixanol. Creatinine clearance was not reduced by any of the contrast media. Fraction excretion of sodium increased immediately and lasted for 30 min after angiography; these changes were more pronounced with ioxaglate than with iomeprol and iodixanol. Urinary gamma-glutamyl transferase increased for 120 min after angiography with iodixanol and iomeprol; these changes were more pronounced with iomeprol than with iodixanol. On the other hand, urinary nu-acetyl-beta-glucosaminidase increased for 120 min after angiography with iomeprol, but was unchanged with iodixanol. CONCLUSION: The use of contrast media induces osmotic diuresis and its acute effects on the proximal tubular function. However, the iso-osmolality medium iodixanol induces fewer changes than the other two media.

Adult↗
PubMed1998

Single-shot diffusion-weighted echo-planar imaging of normal and cirrhotic livers using a phased-array multicoil.

Single-shot spin-echo diffusion-weighted echo-planar imaging using a phased-array multicoil was performed to distinguish between normal and cirrhotic livers. Sets of 6 images with different b-values were acquired with breath-holding. Significant differences were observed between controls and cirrhosis cases in the signal ratios when the b-value was 383 s/mm2, and apparent diffusion coefficients.

Adult↗
PubMed1998

The discrepancy between 99Tcm-ECD dynamic and static SPET images in patients with ischaemic lesions corresponds to reduced vasoreactivity to acetazolamide.

We evaluated 99Tcm-N,N'-(1,2-ethylenediyl)bis-L-cysteine diethyl ester (99Tcm-ECD) dynamic and static SPET (single photon emission tomographic) images to examine 99Tcm-ECD kinetics under ischaemic cerebrovascular conditions. In 20 patients who showed arterial occlusion on magnetic resonance angiography, dynamic (0-10 min) and static (15-35 min) SPET images were acquired after the intravenous administration of 99Tcm-ECD. Thirteen of the patients had focal perfusion deficits that were more evident on the dynamic than on the static images; the other seven showed no such discrepancy. In those patients with a mismatch between the dynamic and static images, the extent corresponded to reduced vaso-reactivity to acetazolamide. Based on quantitative analysis of the ratio of tracer uptake in affected to that in unaffected areas, the patients with discrepant findings showed significantly different ratios on the dynamic and static images, whereas those with no such mismatch did not. Our results suggest that dynamic 99Tcm-ECD images provide circulatory information and that static images reflect a filling-in phenomenon of ECD metabolites in ischaemic lesions. 99Tcm-ECD dynamic and static SPET images offer an alternative method of detecting mild perfusion deficits without the need for acetazolamide challenge.

Acetazolamide↗
PubMed1998

Radiotherapy for osseous metastases from hepatocellular carcinoma: a retrospective study of 57 patients.

OBJECTIVE: We undertook to evaluate the therapeutic effects of radiotherapy in patients with bone metastases from hepatocellular carcinoma (HCC), identify prognostic factors, and find an optimum radiation schedule. METHODS: We retrospectively analyzed the clinical records of 57 patients (99 sites) with painful bone metastases from HCC from December 1978 to March 1997. Their ages ranged from 51 to 82 yr (mean, 62 yr), and the male:female ratio was 49:8. Among them, there were nine patients (16%) with metastases to other organs. Twenty patients (35%) had a solitary bone metastasis and 37 (65%) had multiple bone metastases. The total radiation dose ranged from 20 to 65 Gy (mean, 43 Gy) and that of the Time, Dose, and Fractionation Factor (TDF) values (per explanation given in text) ranged from 35.2 to 118.2 (mean, 73.2). RESULTS: Pain relief was obtained for 83.8% (83/99) of bone metastases from HCC. Those with a TDF value of > or = 77 (a TDF value of 77 is nearly equal to 48 Gy administered in fractions of 2 Gy each daily or 39 Gy administered in fractions of 3 Gy each daily), responded better than those with a TDF value of < 77 (p < 0.05). Overall, the median survival time from the start of radiotherapy was 179 days (6 months). Patients with a solitary bone metastasis and those without metastases to other organs had a better prognosis (p < 0.05 for both subgroups). CONCLUSIONS: Radiation therapy was effective for bone metastases from HCC, especially for those treated with a TDF value of > or = 77.

Aged↗
PubMed1998

Tuberculous pericarditis: MRI features with contrast enhancement.

Tuberculous pericarditis has decreased in incidence, but early diagnosis and treatment are critical because constrictive pericarditis is a serious complication of this condition. The appearances of tuberculous pericarditis on gadolinium enhanced magnetic resonance imaging are described and the value of this modality in achieving an early diagnosis is emphasized.

Adolescent↗
PubMed1998

Primary structure of Streptomyces griseus metalloendopeptidase II.

Streptomyces griseus metalloendopeptidase II (SGMPII) is a unique protease, since it shows anomalous susceptibility to the proteinaceous "serine protease inhibitors" produced by Streptomyces, such as Streptomyces subtilisin inhibitor (SSI) and its homologous proteins. In this study, we analyzed the amino acid sequence of SGMPII by analyzing various peptide fragments produced enzymatically. The sequence of SGMPII, which is composed of 334 amino acids, showed no extensive similarity to SSI-insensitive metalloproteases produced by other species of Streptomyces, except for the amino acid residues essential for catalysis and zinc binding. However, SGMPII is 35-41% similar to thermolysin and its related metalloproteases, which are not inhibited by SSI, and the residues presumed to be critical for catalysis and zinc-binding are well conserved in SGMPII. Glu137 in a "His-Glu-Xaa-His" motif of SGMPII was identified as the residue modified by CICH2 CO-DL-(N-OH)Leu-Ala-Gly-NH2, an active-site-directed irreversible inhibitor of thermolysin-like metalloproteases. Based on the sequence comparison of SGMPII and other bacterial metalloproteases, we discuss the structural basis for the differences in substrate specificity and stability between SGMPII and other thermolysin-like proteases. A possible SSI-binding locus of SGMPII is also proposed.

Amino Acid Sequence↗
PubMed1998

Using MR imaging to predict and evaluate the response of invasive cervical carcinoma to systemic chemotherapy.

OBJECTIVE: The goal of our study was to evaluate the accuracy of MR imaging in predicting the response of invasive cervical carcinoma to systemic neoadjuvant chemotherapy, to observe with MR imaging the difference in tumor response to chemotherapy between treatment cycles, and to correlate tumor size between MR imaging after chemotherapy and surgical specimen. SUBJECTS AND METHODS: Pelvic MR imaging was performed before and after chemotherapy in 41 patients with invasive cervical carcinoma. The difference in tumor reduction between the second course and the third or fourth course of treatment was statistically evaluated in 12 patients. MR images obtained after chemotherapy were compared with surgical specimens to determine residual tumor size in 10 patients. RESULTS: Tumor volume, complete replacement of cervical stroma with carcinoma, and uterine body involvement by tumor observed in the MR images before treatment were found to be significant factors in predicting tumor response. No difference in tumor reduction was found between the second course and the third or fourth course of chemotherapy. Estimates made on MR imaging of tumor size after chemotherapy were within 5 mm of the resected samples. CONCLUSION: Pelvic MR imaging proved useful in predicting and assessing the response of invasive cervical carcinoma to chemotherapy.

Adult↗
PubMed1998

[Transjugular intrahepatic portosystemic shunt for the treatment of refractory ascites].

Five cirrhotic patients with refractory ascites were treated with transjugular intrahepatic portosystemic shunt (TIPS). Before TIPS, although patients were received salt restriction (5 g/day), diuretic therapy (furosemide 112 mg/day, spironolactone 140 mg/day), albumin infusion and paracentesis, ascites did not show improvement. After TIPS, urine volume and urinary sodium excretion increased significantly. Mean body weight decreased significantly from 73 kg before TIPS to 63 kg a month after TIPS. Improvement of ascites after TIPS were associated with a significant reduction in the dose of diuretics. On discharge, complete resolution of ascites was found in 2 patients and mild ascites remained in 3 other patients. Four patients presented 6 episodes of shunt stenosis in the follow-up period, and were treated with balloon dilatation. Ascites increased on shunt dysfunction and showed improvement after balloon dilatation. Post-TIPS encephalopathy was seen in 2 patients and one of 2 was disabled. In conclusion, although post-TIPS shunt dysfunction and encephalopathy are common. TIPS is an effective therapy for refractory ascites in patients with cirrhosis.

Ascites↗
PubMed1998

[Three-dimensional CT angiography for cerebral aneurysm using a multi-angle reconstruction plan method].

The purpose of this study was to evaluate the clinical usefulness of three-dimensional CT angiography (3D-CTA) for the diagnosis of cerebral aneurysm using a new reconstruction method called Multi-Angle Reconstruction Plan (MARP). The threshold values, region of interest and six angles of view were preset for the MARP method on the basis of our experience with cerebral 3D-CTA. Spiral CT angiography was performed in 27 patients with 29 aneurysms. The six images reconstructed with the MARP method were generated from the volumetric CT data. Two radiologists independently reviewed the six 3D-CT images for the presence of aneurysm. It took about five minutes to semiautomatically reconstruct the six 3D-CT images with the MARP method. There were no discrepancies in the evaluation of the 3D-CT images. Twenty-six aneurysms of 24 patients were demonstrated on the six 3D-CT images. Three aneurysms in 3 patients were not depicted on the 3D-CT images by the MARP method. In them, the additional 3D-CT images which were generated after evaluating the 2D-CT images clearly showed the aneurysms. The MARP method is considered to be a useful three-dimensional reconstruction technique for the diagnosis of cerebral aneurysm.

Adult↗
PubMed1998

[99mTc-tetrofosmin exercise leg perfusion scintigraphy in arteriosclerosis obliterans (ASO)--assessment of leg ischemia using two phase data acquisition].

Twenty-one patients with arteriosclerosis obliterans (ASO) were studied with 99mTc-tetrofosmin exercise leg perfusion scintigraphy using the delayed administration method. In this method, tracer was injected 4 minutes after termination of symptom-limited repetitive climbing of a stair to validate prolonged vasodilatation in an ischemic lower limb after exercise. Visual and quantitative analyses were performed to evaluate a diseased leg using dynamic and static images. On a posterior whole body image, all cases except one showed decreased foot uptake in the affected side (affected normal ratio; ANR = 0.82 +/- 0.14). On dynamic images, 9 cases showed transient hyper-accumulation (blush phenomenon) only in the thigh of the affected side suggesting that this valuable finding may be a useful diagnostic sign to distinguish a diseased leg. Sensitivity and positive predictive value were 71.4% and 93.8% to detect a diseased leg based on more than one finding of non-visualization of ilio-femoral artery, muscle-soft tissue blush, and early venous return in a dynamic study. Moreover, a low uptake of ANR of below 0.90 in the foot in the static study gave an improved sensitivity of 85.7%. The transit time of the diseased legs (12.0 +/- 3.1 sec.) which was determined as the interval between the time of arterial and venous peak counts was significantly shorter than that of normal legs (17.3 +/- 4.5 sec.; p < 0.0001, paired t-test). The cases with blush phenomenon showed significantly higher thigh ANR (1.04 +/- 0.11) than those without (0.94 +/- 0.08; p < 0.05, unpaired t-test). These results could reflect prolongation of a hypervascular state after exercise in a diseased leg which sometimes induced blush phenomenon at arterial phase and high leg uptake at static phase. This scintigraphy is useful for the detection of a diseased leg as well as for grasping changes of vascular regulation after stress in patients with ASO.

Aged↗
PubMed1998

[Clinical usefulness of "optimal threshold setting plan" for reconstruction of three-dimensional CT imaging: preliminary clinical study on hepatic tumors and hepatic parenchymal disease].

Clinical application of three-dimensional CT (3D-CT) angiography using the volumetric acquisition capabilities inherent in spiral CT has provided 3D-CT images of vascular structures as well as visceral organs. However, the standard method for deciding the threshold, which is an important process for defining regions of interest, has not yet been established. The setting of an inappropriate threshold may result in reconstruction of a 3D-CT image, leading to misdiagnosis. To simplify the determination of the optimal threshold in a way consistent with the purpose of reconstructing a 3D-CT image, we developed an Optimal Threshold Setting Plan (OPT Plan). With this method, an optimal 3D-CT image could be selected from among those multiple 3D-CT images that were reconstructed on the basis of the multiple thresholds input in advance by referring to attenuation values in both the hepatic lesion and its background on two-dimensional CT images. Clinical usefulness of the OPT Plan for the reconstruction of 3D-CT images was evaluated in 10 patients with hepatic tumors and hepatic parenchymal disease. We obtained 13 3D-CT images (on average) with threshold changes every 5 Hounsfield units, with a mean reconstruction time of 2 minutes 49 seconds, and easily selected an adequate 3D-CT image. Based upon this preliminary experience, the OPT Plan may resolve the difficulty encountered in the setting of thresholds for achieving 3D-CT images, and is considered to be useful for three-dimensional qualitative evaluation of hepatic lesions and hepatic parenchymal disease.

Adult↗
PubMed1998

[Clearance of gadolinium contrast agent by hemodialysis: in vitro and clinical studies].

In order to evaluate the safety and pharmacokinetics of gadolinium contrast agents in patients with hemodialysis, in vitro and clinical studies were performed. Gd-DTPA and Gd-HP-DO3A solutions were dialysed by standard methods. One classic type (cellulose acetate) and two high-performance types (PMMA and polyacrylonitrile) were used. Eleven dialysis patients underwent normal dose contrast MRI followed by usual dose hemodialysis (HD). PMMA dialysis membranes were used for 8 patients and cellulose acetate membranes for 3 patients. Serum levels of gadolinium, BUN and creatinine were analyzed before and after the 1st HD and after the 2nd, 3rd and 4th HD. Side effects and edema were carefully observed. In vitro studies showed that 11.1 hours of dialysis would be necessary to remove 97% of the injected dose of contrast agent by using a first-order kinetic model of dialysis time. When dialysis membranes and contrast agents were compared, statistically significant differences were noted between dialysis membranes and all contrast agents. In the clinical study, 79.1% of the contrast agent was dialyzed after the 1st dialysis and 99.6% after the 4th dialysis. These results showed that all contrast agents and both dialysis membranes were suitable. Neither changes in laboratory parameters nor side effects were observed. The present study suggests, consequently, there are no contraindications when using the ordinary dose of contrast agent even in patients with dialysis.

Aged↗
PubMed1997

Molecular targeting of mitomycin C chemotherapy.

In 10 human cancer cell lines, the activity of mitomycin C (MMC) was found to be determined by an interplay between activation by DT-diaphorase (DTD) and inactivation by glutathione S-transferase (GST). NADPH/cytochrome P-450 reductase was not responsible for MMC activation and expression of MDRI (Mr 170,000 P-glycoprotein), and MRP (multidrug resistance-associated protein) genes did not relate to MMC resistance. Gene expression analysis for NQO1 (DTD gene) and GSTpi predicted which enzyme activity predominated in a cell line, except K562 and K562/DOX. For tumors with DTD activity only, MMC given by itself was most active. In cell lines in which DTD action was predominant, tumor selectivity was achieved by enhancing DTD-mediated activation with m-iodobenzylguanidine and hyperglycemia, which reduced the intra-tumoral pH. KW2149, a novel MMC analogue activated by glutathione, was most active against tumors in which GSTpi predominated. These various enzyme-specific effects could be observed even in cell lines derived from tumors with multidrug resistance. Such MMC treatment based on cell enzymology may enhance significantly MMC efficacy, helping to overcome multidrug resistance.

Animals↗