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T Kumazaki

Publications and source records attributed to T Kumazaki.

At least 109 records · Page 6Linked to original sources
PubMed1997

[Postoperative three-dimensional CT angiography (3D-CTA) in evaluation of proximal clipping for ruptured vertebral aneurysms].

At present, intra-arterial angiography remains the gold standard for most cerebrovascular problems. Recently, three-dimensional computed tomographic angiography (3D-CTA) has been reported as a screening method for the diagnosis of cerebrovascular disease. This imaging modality uses the information obtained on a contrast-enhanced CT scan to generate three-dimensional images of the cerebrovascular system. We performed 3D-CTA in the preoperative and postoperative evaluation of patients undergoing proximal clipping of ruptured vertebral artery aneurysms in addition to conventional cerebral angiography. In this study, the value of 3D-CTA after proximal clipping of ruptured vertebral artery aneurysm was evaluated retrospectively. Six patients were examined with a spinal CT (HITACHI CT-W 3000) after intravenous bolus injection of 100 ml contrast material (Iohexhol 300 mgI/ml) at the rate of 2 ml/s with a 25 second pre-scanning delay. The images of 3D-CTA were reconstructed using a new 3D-volume-render (Voxel Transmission) technique. The ages of the six patients ranged from 33 to 61 years and five cases were males and one case was female. Only one patient had a saccular aneurysm and the other five had fusiform aneurysms. Two patients underwent emergency operations within 4 days, and the other four had delayed operations. The outcome was good recovery in five cases and severe disability in one case. Postoperative conventional cerebral angiography demonstrated no delineation of the aneurysms in five cases. These results correspond well to postoperative 3D-CTA. Postoperative conventional cerebral angiography could not be performed in only one patient, but the aneurysm was visualized on the third postoperative 3D-CTA. Proximal clipping is still one of the therapeutic options for ruptured vertebral aneurysms, but some reports emphasized the possibility of rebleeding after proximal clipping of vertebral artery aneurysms. The rebleeding occurred within 1 week after proximal clipping in 6 of 9 cases (66.7%), and the prognoses were extremely poor. Therefore, in patients selected for proximal clipping, it is necessary to undertake postoperative evaluation of the aneurysm within one week after proximal clipping. 3D-CTA is minimally invasive and can be easily performed repeatedly, even if the patients are in a poor condition. In conclusion, 3D-CTA is very useful especially for evaluation of ruptured vertebral artery aneurysms following proximal clipping.

Adult↗
PubMed1996

Modulation of hemopoietic factor production in relation to endothelial cell aging by interleukin-1 induction.

In this study, we examined the modulation of hemopoietic factor production by human umbilical vein endothelial cells in relation to aging and the cell cycle under conditions of interleukin-1 (IL-1) induction and noninduction. Under conditions of IL-1 noninduction, messenger RNA expression levels of macrophage colony-stimulating factor (M-CSF) were three times higher in non-S-phase cells of young cultures than those in S-phase cells. Expression levels decreased in non-S-phase cells of old culture and approached levels similar to that of S-phase cells. The expression of neither E-selectin nor erythropoietin (Epo) was detected in cells from the noninduced state. The expression of granulocyte colony-stimulating factor (G-CSF) was not affected by either cellular aging or the cell cycle; however, the amount of product secreted increased significantly in old cells, suggesting that G-CSF production is under posttranscriptional regulation. Under conditions of IL-1 induction G-CSF and M-CSF expression levels were enhanced in both young and old cells. Expression of Epo was not detected whereas E-selectin was induced. Significant M-CSF product was detected in young cells but not in old cells, whereas G-CSF product increased dramatically in both types of cells. The modulation of these factors is discussed in relation to the maintenance of neutrophil concentration, differentiation, and maturation of leukocytes and their possible effect on atherosclerosis.

Base Sequence↗
PubMed1996

Alterations in transcription factor-binding activities to fibronectin promoter during aging of vascular endothelial cells.

Previously, we showed that the expression of the fibronectin (FN) gene is enhanced during aging of human endothelial cells and fibroblasts. To elucidate the mechanism, we explored binding proteins to the FN promoter. The promoter contains sites for the general transcription factors: CAAT-binding transcription factor (CTF), promoter-specific transcription factor-1 (Sp1), and transcription factor-IID (TFIID). The promoter also contains sites for inducible transcription factors, cAMP-responsive element (CRE)-binding protein (CREB), and Activator protein 2 (AP-2). We synthesized 10 different oligonucleotides for these and other potential transcription factor-binding sites. Using these oligonucleotides, we searched for binding proteins in young and old endothelial cells by electrophoretic mobility shift and supershift assays. Our results showed that AP-1 decreased with aging, but Sp1 and CREB1 were unaffected. However, decreased binding activities to CRE at positions -170 and -415 were shown in old cells. This could be explained by the decrease of AP-1 because these CREs bound not only CREB1 but also AP-1. Moreover, we observed that the binding activities of TFIID, CTF, and binding proteins to -40, -120 and -260 regions increased. These differential changes may cause the enhancement of FN expression in senescent cells.

Base Sequence↗
PubMed1996

Effect of iomeprol on renal function immediately after abdominal angiography.

PURPOSE: To investigate the acute renal effects of 2 osmolality levels of iomeprol in a double-blind, randomized, parallel-group study. MATERIAL AND METHODS: Ten patients received iomeprol 300 mg I/ml, and a further 10 received iomeprol 400 mg I/ml intraarterially at routine abdominal angiography. The mean volume of contrast medium administered was 227.3+/-59.3 ml in the iomeprol 300 group and 221.5+/-30.9 ml in the iomeprol 400 group. RESULTS: The urinary minute volume increased immediately after angiography, but tended to return to baseline 120 min after the examination. No significant decrease in creatinine clearance occurred; however, the fraction excretion of sodium increased immediately after angiography. The lysosomal enzyme N-acetyl-beta-glucosaminidase and the proximal tubular brush border enzyme gamma-glutamyl transferase increased up to 120 min after the procedure. Free water clearance was negative during each study period. No statistical differences in any parameter were evident between these 2 groups. CONCLUSION: These results suggest that osmotic diuresis and its acute effect on proximal tubular function are induced by the administration of iomeprol, but that these changes are reversible.

Abdomen↗
PubMed1996

[Quantitation of cerebral blood flow and partition coefficient using 123I-IMP dynamic SPECT with single arterial blood sampling].

A method base on the two-compartment model was developed to measure quantitative cerebral blood flow (CBF) and partition coefficient (lambda) of IMP from dynamic SPECT and single arterial blood sampling. In this method, the linear differential equation of two-compartment model, Yokoi proposed, was employed and quantitative CBF and lambda values were measured with the standard input function calibrated by single arterial sampling. The input function was derived from the standard input function scaled by a factor determined by the single arterial blood sample. This new technique was applied to 5 normal volunteers (Ages ranged from 25 to 29 yr., average 26 yr.). The optimal time to calibrate the standard input function in the individual study and optimal the period of the upper limit time to which input function is integrated from IMP administration for analysis of the equation were determined to minimize the difference between integration of the calibrated standard input function and of the individual input function. Minimization of the difference yields an optimal calibration time (4 to 10 min after IMP administration) and the period of the upper limit time (8 to 60 min after acquisition start). Comparison of CBF and lambda values obtained by the graphical method using the calibrated standard data and individual input function were performed. It should be noted that CBF values were in good agreement between the two methods, respectively (r = 0.92, P<0.01; r = 0.72, p = 0.01). This method is easy to estimate CBF and lambda by only single arterial blood sampling and IMP dynamic SPECT, and useful for routine studies.

Adult↗
PubMed1996

[Evaluation of left ventricular diastolic function using gated SPECT with 99mTc-MIBI].

Development of 3 head SPECT system and 99mTc-labeled radiopharmaceuticals enable us to evaluate left ventricular systolic function on the basis of once gated SPECT routine. This study was focused on assessment of left ventricular diastolic function using 99mTc-MIBI gated SPECT data. Twenty nine patients with ischemic heart diseases underwent 99mTc-MIBI gated SPECT and 99mTc-HSAD ventriculographic assessment of left ventricular diastolic function within 1 month. Region of interests (ROI), simultaneously calculating counts per pixel within ROI, were placed over whole myocardium of 16 serial phasic images reconstructed from gated SPECT data, following selection of the central slice within short axial images. Then, 29 patients were classified into 3 patterns of phase count curve (normal, mixed, and delayed relaxation = diastolic dysfunction). Moreover, 1/3 Count Decreasing Fraction (1/3 CDF) was calculated on the same concept as 1/3 FF. The curve pattern showed significant differences between normal and abnormal group divided on the basis of established indices such as 1/3 FF and PFR, and 1/3 CDF has correlations with 1/3 FF (r = 0.61) and PFR (r = 0.58). We concluded that the new parameters drawn from 99mTc-MIBI gated SPECT data might be feasible for evaluation of diastolic function.

Aged↗
PubMed1996

[Usefulness of multi-plane dynamic subtraction CT (MPDS-CT) for intracranial high density lesions].

We present a new CT technique using the high speed CT scanner in detection and evaluation of temporal and spatial contrast enhancement of intracranial high density lesions. A Multi-Plane Dynamic Subtraction CT (MPDS-CT) was performed in 21 patients with intracranial high density lesions. These lesions consisted of 10 brain tumors, 7 intracerebral hemorrhages and 4 vascular malformations (2 untreated, 2 post embolization). Baseline study was first performed, 5 sequential planes of covering total high density lesions were selected. After obtaining the 5 sequential CT images as mask images, three series of multi-plane dynamic CT were performed for the same 5 planes with a intravenous bolus injection of contrast medium. MPDS-CT images were reconstructed by subtracting dynamic CT images from the mask ones. MPDS-CT were compared with conventional contrast-enhanced CT. MPDS-CT images showed the definite contrast enhancement of high density brain tumors and vascular malformations which were not clearly identified on conventional contrast-enhanced CT images because of calcified or hemorrhagic lesions and embolic materials, enabling us to except enhanced abnormalities with non-enhanced areas such as unusual intracerebral hemorrhages. MPDS-CT will provide us further accurate and objective information and will be greatly helpful for interpreting pathophysiologic condition.

Adult↗
PubMed1996

[Virtual CT endoscopy "Cruising Eye View": development and clinical applications].

We have developed a virtual CT endoscopy, designated as "Cruising Eye View (CEV)", which have generated from spiral volumetric CT data and reconstracted using a new three-dimensional image reconstruction technique. Using this new method, we have reconstructed the inner image of patients with aortic dissection (2 cases) and arteriosclerosis obliterance (3 cases). The view point and view direction could be set arbitrarily in the vessel, so that the site, configuration, and/or degree of the intravascular abnormalities were recognized at first glance. Virtual CT endoscopy with CEV method is a promising, non-invasive strategy for archiving the inner image of diverse aorto-arterial pathologies.

Aortic Dissection↗
PubMed1996

[Helical CT guided lumar sympathetic ganglion block].

Helical CT scan was used as a guide for lumbar sympathetic ganglion block. By examining anatomical location of the block site with the sequential fluoroscope pictures of helical CT scan, we succeeded in the block of sympathetic ganglion easily. It is possible by the use of sequential CT picture to reduce the risk of puncturing essential organ such as the kidney, descending aorta, inferior vena cava and so on. Moreover, we can expect that application of helical CT scan will raise the success rate of block and will decrease the time necessary for the performance of block.

Autonomic Nerve Block↗
PubMed1996

[ECG-gated myocardial SPECT with 99mTc-MIBI in patients with right ventricular infarction].

Although 99mTc-pyrophosphate (PYP) myocardial scintigraphy has so far been widely used for the diagnosis of right ventricular infarction, PYP accumulation disappears within one week or so. To evaluate the myocardial condition of the right ventricle alternatively, myocardial SPECT with 99mTc-MIBI was performed in 16 patients with acute inferior left ventricular infarction, and ECG-gated myocardial SPECT data acquisition was accompanied in 14 of 16 patients. Right ventricular perfusion defect was observed in 4 of 16 patients (RVI (+) group), and the remains were negative (RVI (-) group). Then, right ventricular count increase rate (RV %WT) of MIBI from end-diastole to end-systole was calculated using an automated method which was developed for quantification of wall thickening in our laboratory. The RV %WT was conceived to be an objective index representing right ventricular contractility. RVI (+) group (n = 3) as compared with RVI (-) group (n = 11) had significant lower RV %WT (26.7 +/- 3.2 vs. 49.6 +/- 14.2; p < 0.01). In conclusion, ECG-gated myocardial SPECT with MIBI was considered to be useful for assessment of myocardial perfusion and contractility of right ventricle.

Aged↗
PubMed1996

[MR images of bone marrow in aplastic anemia and correlation between MR findings and age].

We observed 125 lumbar vertebrae in 25 patients with aplastic anemia using a 0.5-T MR imager. Bone marrow patterns of aplastic anemia on STIR images were classified into five types: 1) homogeneously low intensity fatty marrow, 2) fatty marrow with scattered hematopoietic nodules, 3) fatty marrow with marginal hematopoietic regions, 4) fatty marrow surrounded by bandlike hematopoietic regions, and 5) homogeneously high-signal-intensity hematopoietic marrow. STIR images defined the fatty marrow as a markedly hypointense region and the hematopoietic marrow as a high signal intense area. Many cases included the homogeneously fatty marrow and fatty marrow with marginal hematopoietic areas, whereas marrow with a broad range of hematopoiesis was detected in patients younger than 40 years. MR images also demonstrated that fatty marrow could shift to hematopoietic marrow following therapy. MR images were useful for detection of the bone marrow distribution of aplastic anemia, related to aging and treatment.

Adolescent↗
PubMed1996

[A new three-dimensional CT reconstruction method for cerebral arteriovenous malformation: development and clinical evaluation of see-through view method].

The authors developed a new three-dimensional reconstruction method called "See-Through View (STV)" using a spiral CT in evaluating of cerebral arteriovenous malformation (AVM). Spiral CT was performed in eight patients with AVM. STV was obtained by reconstructing with a voxel transmission projection using a double threshold method. In all eight patients, STV images enable us to depict the nidus of AVM from all angles by see-throughing skull bone, evaluating the relationship of the vascular lesions adjacent to other cerebrovascular or skeletal structures. In conclusion, STV will provide us further spatial recognition, and will be greatly helpful for surgical planning.

Adult↗
PubMed1996

[MR imaging of hematopoietic regions in bone marrow of aplastic anemia : diagnostic usefulness of opposed phase T1-weighted images].

The signal intensity of hematopoietic regions in the marrow of aplastic anemia were investigated on opposed phase T1-weighted images (op-T1WI) with a 0.5-Tesla MR unit. Hematopoietic regions were classified into two groups : 1) low intensity hematopoietic areas (LH) isointense to normal marrow and 2) high intensity hematopoietic regions (HH) with higher intensity than normal marrow on op-T1WI. a) The signal intensity of LH was significantly lower than that of HH on STIR. b) LH converted in to HH with improvement of laboratory data after therapy, whereas HH decreased with impairment of data. c) In addition, HH were hyperintense to cerebrospinal fluid on op-T1WI. These results indicated that the signal intensity of hematopoietic regions on op-T1WI reflected the cellularity in these regions and that aplastic anemia included hypercellular regions relative to normal marrow.

Adolescent↗
PubMed1996

[3D contrast MR angiography of lower extremity : additional imaging with subtraction].

Immediately after pelvic contrast MRA, subtraction MRA with additional administration of contrast agent was performed for evaluation of the femoropopliteal artery. Mask images were taken with three- dimensional spoiled GRASS (24/6.9/40 degrees), followed by contrast images with 7.5 - 10 ml of Gd-DTPA. The subtracted images provided excellent depiction of the arteries without the disruption of overlapping from the venous system or surrounding tissues. Seven lesions of arterial occlusion or stenosis were pointed out by subtraction MRA in the nine lesions confirmed with IADSA. Subtraction MRA is feasible for long segment imaging of the lower extremities with Gd-DTPA.

Adult↗
PubMed1996

[Interventional radiology for portal hypertension. PTO.TIO].

Percutaneous transhepatic obliteration (PTO) and transileocolic vein obliteration (TIO) are techniques of interventional radiology for embolization of collaterals due to portal hypertension 1) We can obtain good results from the precise selection of these techniques in accordance with the patient's hemodynamics and general condition. 2) Endoscopic injection sclerotherapy (EIS) combined with PTO or TIO for esophageal varices proves to be superior in reliability and durability to EIS alone, and the time before retreatment is much longer when this combination therapy is used. 3) In the intractable EIS only cases, a distinct improvement in results and prognosis appears in using PTO or TIO and also in adding more EIS thereafter. 4) After treatment with EIS and PTO or TIO for cardiac varices, we obtain better results in the disappearance rate as well as in the recurrence rate compared with EIS alone. 5) Gastric varices disappear and hepatic encephalopathy due to porto-systemic shunt is improved after PTO or TIO or using these with balloon occluded retrograde transvenous obliteration (BRTO). Thus PTO and TIO would be analogous to surgical devascularization or ligation. Therefore it is concluded that the best results would be obtained with PTO or TIO with other nonsurgical treatments.

Aged↗
PubMed1996

[Three-dimensional measurement of vascular lesions with virtual CT endoscopy "cruising eye view" method].

The purpose of this report is to propose a new technique which allows three-dimensional measurement of vascular lesions based on the virtual CT endoscopy "Cruising-Eye-View (CEV)" method. The view-point of CEV imagings was used as measuring point of vascular lesions. Using this technique, we could measure the actual length of arterial stenosis along the vessel in 3 patients with arteriosclerosis obliterans. The three-dimensional measuring technique with the CEV method may become a useful tool in treatment planning before interventional radiology, including metallic stent placement.

Angiography↗