Biomedical subjects

Tomio Inoue

Publications and source records attributed to Tomio Inoue.

At least 55 records · Page 3Linked to original sources

PubMed2003

Effect of biventricular pacing on myocardial glucose metabolism in patients with heart failure using fluoro-18-deoxyglucose positron emission tomography.

Biventricular pacing has recently been found beneficial in the treatment of congestive heart failure (CHF). Meanwhile, positron emission tomography (PET) has emerged as a new method to analyze glucose metabolism in the heart. Five patients (mean age 68.8 +/- 8.1 years, 4 men) who received biventricular pacing therapy for 5.8 +/- 6.6 weeks for CHF were studied. Myocardial glucose metabolism was evaluated by PET with fluoro-18-deoxyglucose (18F-FDG), and percent uptake (%uptake) of 18F-FDG was calculated during biventricular pacing and compared with that during 1 hour of conventional RV pacing. Biventricular pacing was associated with a significant decrease in NYHA functional Class from 3.67 +/- 0.52 to 2.50 +/- 0.55. After 18F-FDG PET, three of five patients remained clinically stable, and two died during follow-up. Mean 18F-FDG %uptake during biventricular pacing was not different than during short-term RV pacing (62.1 +/- 18.4 vs. 63.6 +/- 17.0%). However, patients who remained clinically stable had a lower value of 18F-FDG %uptake in the septal region than patients who died (46.9 +/- 5.6 vs 80.3 +/- 1.3%, P < 0.01). One patient whose cardiac function improved significantly also had a small septal region of decreased 18F-FDG uptake during RV pacing. In conclusion, biventricular pacing therapy was effective in this small group of patients with severe, drug-resistant CHF. An evaluation of the effects of biventricular pacing on glucose metabolism in the subacute phase may help identify patients with a favorable long-term response to this therapy.

Aged↗

PubMed2003

Nuclear translocation of DNase II and acid phosphatase during radiation-induced apoptosis in HL60 cells.

DNase II is involved in DNA fragmentation induced by a variety of treatments. However, according to past reports DNase II does not directly generate TUNEL (in situ DNA end labeling)-positive cells. The purpose of this study was to investigate the participation of acid phosphatase in the generation of TUNEL-positive cells. DNase II-like proteins, whose molecular weights were 32-kDa, were detected in nuclear extracts of HL60 human myeloid leukemia cells post gamma-irradiation by SDS-PAGE and immunohistochemistry. Acidic nuclease activity was especially active in 32-kDa bands TUNEL assay was positive post gamma-irradiation. From measurements of the activity of acid phosphatase, the activity in nuclear extracts increased remarkably post gamma-irradiation. Gamma-irradiation can directly or indirectly activate DNase II. Once DNase II and acid phosphatase have been translocated from lysosomes into the nuclei, DNase II generates TUNEL reactive ends in combination with acid phosphatase.

Acid Phosphatase↗

PubMed2003

Neural mechanism of propofol anesthesia in severe depression: a positron emission tomographic study.

BACKGROUND: The precise neural mechanisms of propofol anesthesia in humans are still unknown. The authors examined the acute effects of propofol on regional cerebral blood flow (rCBF) using positron emission tomography in patients with severe depression. METHODS: In six severely depressed patients (mean age, 55.0 yr) scheduled for electroconvulsive therapy, anesthetic levels were monitored by electroencephalography, and rCBF was serially quantified in the awake, sedated, and anesthetized states. The authors used high-resolution positron emission tomography with 15O-labeled water and statistical parametric mapping 99 for imaging and analysis of the data. RESULTS: Global cerebral blood flow showed sharp decreases from the awake level during the administration of propofol, decreasing 26.8% in the sedated state and 54.4% in the anesthetized state. Moreover, a dose effect was seen in both parietal cortices and the left lateral prefrontal region with larger regions of relative decrease in rCBF at higher propofol doses. At the higher dose, the values of rCBF in the pulvinar nucleus of the thalamus, the pontine tegmentum, and the cerebellar cortex were also affected. Meanwhile, there were few changes of relative rCBF in the basal frontal lobes during both sedated and anesthetized states. CONCLUSIONS: As in earlier studies using normal subjects, pronounced suppression in rCBF in the brain stem reticular formation, the thalamus, and the parietal association cortex occurred even in severely depressed patients. However, previously reported decreases in rCBF in the basal frontal lobe were absent in depressed patients.

Adult↗

PubMed2002

Involvement of 5-HT7 receptors in serotonergic effects on spike afterpotentials in presumed jaw-closing motoneurons of rats.

Intracellular recordings were obtained from rat presumed jaw-closing motoneurons in slice preparations to investigate the involvement of the serotonin(7) (5-HT(7)) receptors in serotonergic inhibition of the postspike medium-duration afterhyperpolarization (mAHP) and enhancement of the afterdepolarization (ADP). 5-HT-induced suppression of the mAHP and enhancement of the ADP were mimicked by application of the 5-HT(1A/7) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and antagonized by the 5-HT(2/6/7) receptor antagonist clozapine, whereas the 5-HT(2) receptor agonist alpha-methyl-5-hydroxytryptamine (alpha-methyl-5-HT) did not affect the mAHP and ADP. 8-OH-DPAT-induced attenuation of the mAHP and enhancement of the ADP were also antagonized by clozapine and another 5-HT(2/6/7) receptor antagonist ritanserin, whereas the 5-HT(1A) receptor antagonist pindolol failed to block the 8-OH-DPAT-induced effects on the mAHP and ADP. 8-OH-DPAT-induced suppression of the mAHP and enhancement of the ADP were also antagonized by a protein kinase A (PKA) inhibitor H89, whereas 8-OH-DPAT could inhibit the mAHP and enhance the ADP in the presence of a protein kinase C (PKC) inhibitor chelerythrine. The 8-OH-DPAT-induced suppression of the mAHP was enhanced under raised [Ca(2+)](o) and this enhancement was reduced by chelerythrine. It is suggested that the 5-HT(7) receptors are involved in 5-HT-induced attenuation of the mAHP and enhancement of the ADP through activation of PKA, and the attenuation of mAHP through the 5-HT(7) receptors is enhanced under raised [Ca(2+)](o) by PKC activation.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed2002

Influence of oro-facial sensory input on the output of the cortical masticatory area in the anesthetized rabbit.

In order to study the role of sensory inputs to the cortical masticatory area (CMA) and plasticity in the CMA, the representation of sensory inputs and the change of sensory inputs and motor outputs in the CMA 16 days after trigeminal deafferentation in the rabbit were examined. Neuronal activity was recorded in response to mechanical and electrical stimulation of the oro-facial region and cortically-induced rhythmical jaw movements (CIRJMs) were analyzed. Cortical neurons with receptive fields in the deafferented region were not found in the CMA. However, the projection area of the intact lingual nerve extended both antero-posteriorly and medio-laterally in the CMA and included neurons with long latency responses to lingual nerve stimulation. In a previous study in the rabbit, CIRJMs were classified into two groups according to their similarity to normal masticatory patterns: one pattern resembled that occurring during the food transport stage (T-pattern), and the other resembled that occurring during the chewing stage (C-pattern). These two patterns of CIRJMs were evoked from different stimulation sites: T-patterns were induced from the dorsal CMA and C-patterns were induced from the ventral CMA. The relationship between the patterns of CIRJMs and the site of stimulation in the deafferented rabbits was similar to that observed in normal rabbits. This finding suggests that sensory inputs to the CMA may not directly influence the CMA motor outputs controlling jaw movements, despite a close spatial relationship between the input and output of this area.

Animals↗

PubMed2002

Comparison between positron emission tomography and computed tomography in the use of the assessment of esophageal carcinoma.

BACKGROUND: The role and potential value of positron emission tomography (PET) scanning in certain tumors has been widely investigated in recent years. The authors retrospectively assessed the performance of 18-F-fluorodeoxyglucose (FDG)-PET in the assessment of esophageal squamous cell carcinoma (SCC). METHODS: The results using PET were compared with those using computed tomography (CT), and these were correlated with the pathologic findings. The authors studied 32 patients with thoracic esophageal SCC who had undergone radical esophagectomy. RESULTS: Uptake of FDG in the primary tumor was found in 25 of the 32 (78.1%) cases. Comparison of the FDG uptake and the clinicopathologic findings showed that there was a significant association between the FDG uptake and each of the depth of tumor invasion (P < 0.05), occurrence of lymph node metastasis (P < 0.01), and lymphatic invasion (P < 0.01). The survival rate in cases with high FDG uptake (standardized uptake value [SUV], >3) was significantly lower than that in cases with low FDG uptake (SUV, < 3; P < 0.05). In the evaluation of lymph node staging by the detection of lymph node metastasis, FDG-PET showed 77.8% sensitivity, 92.9% specificity, and 84.4% accuracy, and CT scanning showed 61.1% sensitivity, 71.4% specificity, and 65.6% accuracy. Positron emission tomography scanning showed a high degree of accuracy in the neck, upper thoracic, and abdominal regions. However, in the mid- and lower thoracic regions, the sensitivity was very low. The smallest lymph node metastasis that was detected by FDG-PET imaging was 6 mm. The average size of lymph node metastasis that was undetected by FDG-PET scanning was 7.3 mm (range, 1-17 mm). CONCLUSIONS: In conclusion, FDG-PET may be used as a noninvasive diagnostic technique in assessing the aggressiveness of the tumor and the prognosis in patients with esophageal SCC. During the preoperative diagnostic procedures, the sensitivity, specificity, and accuracy of lymph node staging is higher with FDG-PET than with CT imaging. In view of the high specificity of FDG-PET, it also gives useful information to guide the choice of treatment of esophageal carcinoma.

Adult↗

PubMed2002

Present diagnostic strategies for acute pulmonary thromboembolism; results of a questionnaire in a retrospective trial conducted by the Respiratory Nuclear Medicine Working Group of the Japanese Society of Nuclear Medicine.

The aim of this study is to re-evaluate and clarify the diagnostic role of ventilation/perfusion lung scintigraphy in Japan, now that single-detector-row helical CT and multidetector-row CT are available in clinical practice. The Respiratory Nuclear Medicine Working Group of the Japanese Society of Nuclear Medicine distributed a questionnaire to institutions in Japan equipped with scintillation cameras as of September 2001. Of 1,222 institutions, 239 returned effective answers (19.6%). The most frequent combination for initial diagnosis of acute pulmonary thromboembolism was chest radiography, perfusion lung scintigraphy, and contrast-enhanced CT (111 institutions, 46.4%). The questionnaire revealed that the validity and usage of perfusion lung scintigraphy and those of contrast-enhanced CT were equivalent in the present clinical situation. On the other hand, the diagnostic value of ventilation lung scintigraphy in suspected pulmonary thromboembolism has not been established in Japan. Even though contrast-enhanced CT is widely used in Japan, perfusion lung scintigraphy is still required to determine disease severity and monitor its progress.

Acute Disease↗

PubMed2002

Anti-tachycardia therapy can improve altered cardiac adrenergic function in tachycardia-induced cardiomyopathy.

We investigated whether anti-tachycardia therapy might improve the altered cardiac adrenergic and systolic function in tachycardia-induced cardiomyopathy (TC) in contrast to dilated cardiomyopathy (DCM). The subjects were 23 patients with heart failure, consisting of 8 patients with TC (43.6 +/- 10.0 yrs) and 15 with DCM (45.3 +/- 8.2 yrs). TC was determined as impairment of left ventricular function secondary to chronic or very frequent arrhythmia during more than 10% of the day. All patients were receiving anti-tachycardia treatment. Cardiac 123I-MIBG uptake was assessed as the heart/mediastinum activity ratio (H/M) before and after treatment. LVEF was also assessed. In the baseline study, H/M and LVEF showed no difference between TC and DCM (2.21 +/- 0.44 vs. 2.10 +/- 0.42, 35.3 +/- 13.1 vs. 36.0 +/- 10.9%, respectively). After treatment, the degree of change in H/M and LVEF differed significantly (0.41 +/- 0.34 vs. 0.08 +/- 0.20, 20.5 +/- 14.4 vs. -2.1 +/- 9.6%, p < 0.01). In TC, heart failure improved after a shorter duration of treatment (p < 0.05). In conclusion, anti-tachycardia therapy can improve altered cardiac adrenergic function and systolic function in patients with TC over a shorter period than in those with DCM.

3-Iodobenzylguanidine↗

PubMed2002

A shifting landscape: what will be next FDG in PET oncology?

The tumor-seeking agent most widely used in positron emission tomography (PET) is 2-(18)F-fluorodeoxy-D-glucose (FDG). The clinical usefulness of FDG PET has already been proved in detecting, staging and restaging various kinds of malignant tumors, but nuclear medicine physicians suffer from a "diagnostic dilemma," in which a relatively high false positive ratio of FDG PET in diagnosing malignant tumors prevails. To increase more specific tumor uptake or more specific tumor characterization, numerous PET radiopharmaceuticals have been developed, and some of them are being tested in clinical trials. This review will briefly survey the tumor uptake mechanism and clinical significance of representative non-FDG PET radiopharmaceuticals used in clinical trials for patients with cancers.

Adult↗

PubMed2002

Maturational changes in airway remodeling after chronic exposure to ovalbumin in sensitized guinea pigs: role of cell renewal of airway resident cells.

We wanted to know whether airway remodeling caused by chronic exposures to antigen differed depending on the degree of maturation of animals. We sensitized guinea pigs at different stages of maturation: juvenile (approximately 200 g in body weight), adult (400 g), and old animals (800 g). Then, animals were repeatedly challenged with inhaled ovalbumin (0.3% or 3%) or vehicle twice a week for 6 wk. After the final challenge, the lungs were excised for the histologic evaluation of changes in the thickness of the inner wall area (Ti), the smooth muscle area (Tm), and the outer wall area (To) in noncartilaginous airway dimensions. To clarify whether or not the observed changes were due to renewal of airway cells, we stained the samples with labeled nucleotide 5'-bromo-2'-deoxyuridine (BrdU), which we injected repeatedly during the challenge periods. Chronic exposures to antigen induced airway wall thickening regardless of their stages of maturation. However, prominent areas of thickening differed between the three groups. Ti increased more remarkably in juvenile and adult animals than in old ones. By contrast, Tm significantly increased only in old animals. BrdU staining revealed more renewal of epithelial cells in juvenile and adult animals than in old ones (juvenile >or=adult > old), suggesting that increased renewal of epithelial cells contributed to the thickening of Ti in juvenile and adult animals. By contrast, only a slight increase in smooth muscle cell renewal was found even in old animals, indicating that an increase in Tm was due to factors such as hypertrophy. These results show that the development of antigen-induced airway remodeling is partly modified by the degree of maturation of animals in vivo.

Animals↗

PubMed2002

[Efficacy of biventricular pacing on myocardial glucose metabolism in a patient with heart failure using 2-deoxy-2[18F]fluoro-d-glucose positron emission tomography: a case report].

A 61-year-old-male with dilated cardiomyopathy and congestive heart failure was treated by implantation of a biventricular pacemaker. Myocardial glucose metabolism was evaluated by positron emission tomography with 2-deoxy-2[18F]fluoro-d-glucose (FDG) during atrial-right ventricular pacing or atrial-biventricular pacing. Percentage uptake of FDG decreased in the lower septal area of the left ventricle during right ventricular pacing, but the decrease was improved during biventricular pacing (74.7% vs 91.6%). Biventricular pacing may improve myocardial glucose metabolism in patients with congestive heart failure.

Cardiac Pacing, Artificial↗

PubMed2002

[Multi-center study for the evaluation of clinical usefulness of attenuation and scatter correction on 201Tl myocardial SPECT].

The aim of this study was to evaluate the clinical usefulness of attenuation and scatter correction (AC, SC) on a 201Tl myocardial single-photon emission computed tomography (201Tl SPECT) as a multi-center trial. With a dual-detecter and a triple-detector SPECT systems with a 99mTc transmission source, simultaneous transmission/emission tomography (TCT/ECT) was performed on 38 patients with angiographically coronary heart disease (CHD) and 26 patients without evidence of CHD. Stress and delayed attenuation and scatter corrected images (SAC) and uncorrected images (NC) were reconstructed. On NC images of normal cases, influence of attenuation was greater in male than female. In comparison of 201Tl distribution between male and female, significant decrease in 201Tl activity was observed in the inferoposterior wall in male and that was observed in the anterobasal wall of the left myocardium in female. Such a difference in 201Tl distribution between male and female disappeared on SAC images. On the diagnostic performance for the identification of CHD, SAC images demonstrated improved specificity and accuracy values in the right coronary arterial territory (RCA) with visual analysis statistically. Sensitivity value in the RCA was also improved, but it was not statistically significant. Sensitivity value in the left circumflex arterial territory (LCX) increased without decrease in specificity value on SAC images. In the left anterior descending arterial territory (LAD), sensitivity value increased on SAC images. Although specificity value decreased on SAC images in LAD territory, it was not statistically significant. The difference in 201Tl distribution between male and female is improved in normal cases by attenuation and scatter correction on 201Tl myocardial SPECT. Diagnostic performance of CHD is also improved by attenuation and scatter correction, especially in territories of which specificity in assessing the absence of disease have been suboptimal. In conclusion, attenuation and scatter correction on 201Tl myocardial SPECT is considered to be clinically useful.

Adult↗

PubMed2002

[Evaluation of efficiency of a semiconductor gamma camera].

We evaluation basic characteristics of a compact type semiconductor gamma camera (eZ-SCOPE AN) of Cadmium Zinc Telluride (CdZnTe). This new compact gamma camera has 256 semiconductors representing the same number of pixels. Each semiconductor is 2 mm square and is located in 16 lines and rows on the surface of the detector. The specific performance characteristics were evaluated in the study referring to NEMA standards; intrinsic energy resolution, intrinsic count rate performance, integral uniformity, system planar sensitivity, system spatial resolusion, and noise to the neighboring pixels. The intrinsic energy resolution measured 5.7% as FWHM. The intrinsic count rete performance ranging from 17 kcps to 1,285 kcps was evaluated, but the highest intrinsic count rate was not observed. Twenty percents count loss was recognized at 1,021 kcps. The integral uniformity was 1.3% with high sensitivity collimator. The system planar sensitivity was 33,330 cpm/MBq with high resolution collimator and 766,767 cpm/MBq with high sensitivity collimator. The system spatial resolution (FWHM) was 2.0 mm and 2.2 mm when the distance between source and collimator was 0 cm and 3 cm respectively.

Cadmium Compounds↗

PubMed1999

Image Fusion System Using PACS for MRI, CT, and PET Images.

This paper presents and evaluates Picture Archiving and Communication System (PACS) and its interaction with the image fusion applications using positron emission tomography (PET), CT, and MRI, as well as some clinical applications of fusion images. A network connections between medium-sized PACS involving CT, MRI, SPECT, and PET were developed. Image registration and fusion was achieved in the PET's workstation by Advanced Visual System (AVS) software. Reconstructed datasets of CT, MRI, SPECT, and PET were transferred and archived in PACS servers. Series of anatomical images of CT and MRI were fused with metabolical images of PET with (18)F labeled fluoro-2-deoxy-D-glucose (FDG). Throughput rate of image data, as well as clinical applications of fusion images were evaluated and correlated with phantom studies. The average throughput rate of archiving and processing steps was 0.45 Mbps, 0.77 Mbps, respectively. Image fusion experiment using phantom and patients' data showed high accuracy in all directions. The combination of PACS and image fusion provided very useful clinical tools and made it quite easy to maximize the benefit from the diagnostic imaging.

Journal Article↗

PubMedDate not supplied

Use of 2-[18F]-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) imaging for the evaluation of muscle metabolic activity in ruptured rotator cuffs: Identification of shoulder muscles by fusion imaging studies involving both FDG PET and magnetic resonance imaging.

The uptake of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) into shoulder muscles was studied in 11 patients with rotator cuff tears. FDG was injected under resting conditions, and cuff muscle exercises were performed followed by evaluation of the standardized uptake value (SUV) in shoulder muscles bilaterally. Analysis was performed with a subtracted SUV, obtained by subtracting the SUV of the muscle at rest from that after exercise. Fusion imaging studies involving FDG positron emission tomography (PET) and magnetic resonance imaging would provide a novel strategy with the potential of improving on the limited resolution of PET images. In this study this relatively new strategy revealed a similar decrease in the supraspinatus SUV in cases involving both complete and partial tears. The SUV in the infraspinatus and subscapularis also decreased, regardless of whether these muscles were intact or ruptured; the SUV in the deltoid remained basically unchanged. With the use of this exercise protocol, FDG PET might prove useful for objective evaluation of rotator cuff muscle activity.

Aged↗

PubMedDate not supplied

Congenital absence of the portal vein: clinical and radiologic findings.

Congenital absence of the portal vein (CAPV) is a rare anomaly in which the intestinal and splenic venous drainage bypasses the liver and drains into the systemic veins through various venous shunts. In patients with CAPV, the portosystemic shunting causes disruption of the enterohepatic circulation and leads to various clinical manifestations. CAPV can be diagnosed without invasive techniques. This article illustrates the clinical and radiologic findings (including ultrasound, CT, and MRI) of CAPV.

Adult↗

PubMedDate not supplied

Carbon-11 choline positron emission tomography in musculoskeletal tumors: comparison with fluorine-18 fluorodeoxyglucose positron emission tomography.

PURPOSE: Recently, a new positron emission tomography (PET) tracer, carbon-11 choline, has been introduced in oncology investigations, but the role of choline PET in musculoskeletal tumor evaluation has not been previously examined. This is the first trial to investigate the utility of choline PET in evaluating musculoskeletal tumors in comparison with fluorine-18 fluoro-2-deoxy-D-glucose (FDG) PET. METHOD: Thirty-three patients were examined with both choline PET and FDG PET, of which standardized uptake values (SUVs) were used for evaluation of the lesions. To decide the appropriate cutoff value and compare the two PET studies, receiver operating characteristic curve analysis was used. The binomial test was used for comparison of sensitivities between choline PET and FDG PET. RESULTS: A significant correlation (r = 0.537, P = 0.0013) between choline and FDG SUVs was noted for all lesions (n = 33). Mean SUVs for malignant tumors were significantly higher than those for benign lesions in both choline PET and FDG PET. Using a cutoff value of 2.7 for choline SUVs, the sensitivity for correctly diagnosing malignancy was 92.3% (12/13) with a specificity of 90.0% (18/20), resulting in an accuracy rate of 90.9%. With use of a cutoff value of 3.3 for SUVs in FDG PET, the sensitivity was 84.6% (11/13) with a specificity of 80.0% (16/20), resulting in an accuracy rate of 81.8%. The receiver operating characteristic curves of two analyses showed that the mean area under the curve value of choline PET (0.9577 +/- 0.041) was significantly greater (P = 0.0488) than that of FDG PET (0.8192 +/- 0.0806). There was no significant difference in sensitivity and specificity between choline PET and FDG PET analysis using either the binomial test (P = 0.4531) or McNemar test (P = 0.371). CONCLUSION: Choline PET analysis may not be inferior to FDG PET analysis for differentiating malignant from benign musculoskeletal tumors. The advantages of choline PET were shorter examination time and little retention in the bladder; therefore, this modality may be useful for preoperative planning for musculoskeletal tumors, especially for lesions around the hip joints.

Adolescent↗

PubMedDate not supplied

Right double inferior vena cava: Report of 5 cases and literature review.

OBJECTIVE: To describe the computed tomography appearance, embryology, and clinical implications of right double inferior vena cava (IVC). METHODS: Computed tomography imaging findings were retrospectively reviewed in our 5 patients and in 2 cases reported in the literature with right double IVC. The relationship of the 2 postrenal IVCs, their diameter, level of confluence of the 2 IVCs, course of the left common iliac vein, draining site of the right gonadal vein, and the presence of retrocaval ureter were evaluated. RESULTS: In all cases, the relationship of 2 IVCs was ventral-dorsal, and the left common iliac vein passed ventral to the aortic bifurcation or the right common iliac artery. The relationship of the diameters and level of confluence of the 2 IVCs were variable. The right gonadal vein drained into the ventral vessel in 4 cases and into the IVC between the renal venous confluence and the confluence of the 2 vessels in 1 case. In all cases, the retrocaval ureter was not identified. CONCLUSIONS: Characteristic computed tomography findings of right double IVC were a ventral-dorsal relationship between the 2 vessels and the unusual course of the left common iliac vein. Embryologically, the ventral vessel originates from the right subcardinal vein, whereas the dorsal vessel originates from the right supracardinal vein. Although this anomaly is extremely rare, radiologists should recognize it.

Adult↗