Biomedical subjects

J Hatazawa

Publications and source records attributed to J Hatazawa.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Vascular and metabolic reserve in a case of hypoplasia of bilateral internal carotid arteries].

We report a 64-year-old right-handed man who presented with a hypoplasia of bilateral internal carotid arteries (ICAs). The patient complained of a vertigo and was diagnosed as having a benign paroxysmal positional vertigo. Upon neurological examination, he was completely free from neurological deficits. MR angiogram revealed an occlusion of both ICAs. On conventional angiogram, the right ICA was occluded about 3 cm distal from its origin, and the left ICA was occluded at the precavernous portion. There was an abundant collateral blood flow to the frontal, temporal and parietal lobes through the posterior communicating arteries. Both carotid canals were hypoplastic on 3D-CT. The patient was then diagnosed as having a hypoplasia of both ICAs. Using a positron emission tomography (PET), cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO2), oxygen extraction fraction (OEF), and vascular transit time (VTT) were measured during resting state, and the vascular reactivities to carbon dioxide inhalation (VRCO2), and to the intravenous administration of Acetazolamide (VRACZ) were also evaluated. There was no global or focal reduction in CBF and VTT was within normal limit, whereas a global reduction of CMRO2 caused mild decrease in OEF. Moreover, VRACZ was significantly decreased and an intracerebral steal phenomenon was observed in the parietal cortical areas, whereas VRCO2 was preserved. The discrepancy between VRACZ and VRCO2 observed could be related to the differences in the mechanisms underlying the vasodilating effects of carbon dioxide and ACZ.

Arterial Occlusive Diseases↗

PubMed2000

[Recent progress in diagnostic imaging of cerebrovascular diseases].

The recent development of the neuroimaging modalities has enabled early detection of abnormal cerebral perfusion due to arterial steno-occlusive lesions by means of single photon emission computed tomography (SPECT) and perfusion weighted images of magnetic resonance imaging (MRI), early detection of ischemic brain damage by means of diffusion weighted image of MRI, and lacunar infarction and hemorrhage by means of T 2 * weighted images. These methods are now available for the clinical practice. The imaging technique further visualized various pathological states associated with cerebrovascular disease. The fiber tracts in the white matter and its disruption can be evaluated by anisotropy imaging of MRI. Selective neuronal necrosis after mild ischemia was detected by radioactive tracers specifically bound to neurons. These progress may contribute to uncover the pathophysiology of cerebrovascular diseases and to treat the patients.

Cerebrovascular Circulation↗

PubMed1999

Positron emission tomography in juvenile Alexander disease.

A 13-year-old boy with cervical kyphosis was diagnosed as having juvenile Alexander disease because of the typical MRI findings, abnormally elevated alphaB-crystallin and heat shock protein 27 in the cerebrospinal fluid. Positron emission tomography with 18F-fluorodeoxyglucose demonstrated hypometabolism in the frontal white matter corresponding to the areas with leukodystrophy. However, the overlying gray matter preserved normal glucose metabolism.

Adolescent↗

PubMed1999

Effects of scatter correction on regional distribution of cerebral blood flow using I-123-IMP and SPECT.

The transmission dependent convolution subtraction method which is one of the methods for scatter correction of SPECT was applied to the assessment of CBF using SPECT and I-123-IMP. The effects of scatter correction on regional distribution of CBF were evaluated on a pixel by pixel basis by means of an anatomic standardization technique. SPECT scan was performed on six healthy men. Image reconstruction was carried out with and without the scatter correction. All reconstructed images were globally normalized for the radioactivity of each pixel, and transformed into a standard brain anatomy. After anatomic standardization, the average SPECT images were calculated for scatter corrected and uncorrected groups, and these groups were compared on pixel by pixel basis. In the scatter uncorrected group, a significant overestimation of CBF was observed in the deep cerebral white matter, pons, thalamus, putamen, hippocampal region and cingulate gyrus as compared with scatter corrected group. A significant underestimation was observed in all neocortical regions, especially in the occipital and parietal lobes, and the cerebellar cortex. The regional distribution of CBF obtained by scatter corrected SPECT was similar to that obtained by O-15 water PET. The scatter correction is needed for the assessment of CBF using SPECT.

Adult↗

PubMed1999

Cerebral blood-flow responses to induced hypotension and to CO2 inhalation in patients with major cerebral artery occlusive disease: a positron-emission tomography study.

Our aim was to study the relationship between cerebral blood flow (CBF) responses to induced hypotension and to CO2 inhalation in patients with occlusive disease of the carotid or middle cerebral arteries. In 13 patients (8 men, 5 women) aged 31-73 years (mean +/- 1 SD = 63.2 +/- 10.6), regional CBF values during the resting state (CBFrest), 7% CO2 inhalation (CBFhypercapnia), and hypotension induced by 10-20 microg/kg/min intravenous trimethaphan (CBFhypotension) were measured using positron-emission tomography (PET) with H2(15)O. The % CBF change during induced hypotension (% CBFhypotension) was defined as (CBFhypotension - CBFrest)/CBFrest multiplied by 100. The % CBF change during CO2 inhalation (% CBFhypercapnia) was defined as (CBFhypercapnia - CBFrest)/CBFrest/mm Hg arterial partial pressure of CO2 x 100. We defined symptomatic hemispheres as those with a stenotic or occlusive lesion with neurological symptoms or signs and asymptomatic hemispheres as those which had a similar lesion and/or were influenced by the collateral flow pattern without neurological symptoms. In the territory of the occlusive lesion, % CBFhypotension correlated significantly with % CBFhypercapnia (r = 0.793, P < 0.002) in the symptomatic hemispheres. In the brain regions in which trimethaphan did not induce a reduction in CBF. % CBFhypercapnia was 6.13 +/- 1.79. In those in which % CBFhypotension ranged from 0 to -5, from -5 to -10, and more than -10%, % CBFhypercapnia was 4.05 +/- 1.99, 3.21 +/- 1.17, and 1.73 +/- 1.61, respectively, with significant differences between each pair of groups. In the asymptomatic hemispheres, % CBFhypotension also correlated with % CBFhypercapnia (r = 0.979, P < 0.0001). Failure to maintain CBF during induced hypotension was associated with diminished cerebrovascular vasoreactivity to hypercapnia in patients with arterial disease. This may indicate that failure of autoregulation can be assessed by the CBF response to both induced hypotension and CO2 inhalation. From the technical point of view, estimation of the CO2 response may be useful for assessing failure of autoregulation.

Administration, Inhalation↗

PubMed1999

Immunohistochemical assessment of superoxide dismutase expression in the endometrium in endometriosis and adenomyosis.

OBJECTIVE: To determine the expression of superoxide dismutase (SOD) in the endometrium during the menstrual cycle in endometriosis and adenomyosis. DESIGN: Immunohistochemical identification of SOD in endometrial tissues using the monoclonal antibody. SETTING: Department of obstetrics and gynecology in a university hospital. PATIENT(S): The subjects were divided into three groups: 36 patients with endometriosis, 38 patients with histologically proven adenomyosis, and 47 fertile control subjects. INTERVENTION(S): Endometrium was biopsied throughout the menstrual cycle. MAIN OUTCOME MEASURE(S): Semiquantitative immunostaining (evaluation nomogram) score for endometrial cells. RESULT(S): The analyses revealed phase-dependent changes in the expression of SODs in the glandular and surface epithelia during the menstrual cycle in fertile controls. Specifically, the expression of copper, zinc SOD was weakest in the early and midproliferative phases, then gradually increased, and was most marked in the early and midsecretory phases. The expression of manganese SOD reached a peak in the late secretory phase. The expression of both SODs in endometriosis and adenomyosis was persistently higher than the control levels throughout the menstrual cycle. CONCLUSION(S): The exaggerated expression of both SODs in the endometrium throughout the menstrual cycle suggests that superoxide plays a key role in infertility in endometriosis and adenomyosis.

Adult↗

PubMed1999

Blood flow and metabolism of oligodendrogliomas: a positron emission tomography study with kinetic analysis of 18F-fluorodeoxyglucose.

To accurately characterize the pathophysiology and proliferating activity of oligodendrogliomas, we studied cerebral blood flow and metabolism using positron emission tomography (PET) in five patients with this tumor. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), oxygen extraction fraction (rOEF), and cerebral metabolic rates of oxygen (rCMRO2) and of glucose (rCMRGl) were quantitatively measured in tumor lesions and the contralateral gray matter, rCMRGl was analyzed based on both kinetic and autoradiographic methods. Tumor rCBF and rCBV were lower than in the contralateral gray matter in all preoperatively examined patients. Oxygen metabolism, determined by rCMRO2 and rOEF, was consistently reduced in the tumor (rCMRO2, P<0.05 vs. gray matter, determined by the Student's t-test). Tumor rCMRGl was significantly lower than the gray matter rCMRGl in both kinetic (P<0.01) and autoradiographic (P<0.05) analyses. Kinetic tumor rCMRGl varied between 1.22 and 4.13 mg/100 ml/min, but was lower than the gray matter value in all patients. Autoradiographic tumor rCMRGl, which ranged from 1.02 to 5.79 mg/100 ml/min, was also reduced in all tumors but one; the remaining tumor, which had a relatively high value of autoradiographic rCMRGl (comparable to gray matter rCMRGl), infiltrated the contralateral hemisphere through the corpus callosum, and was characterized by high cellular density. In one patient who suffered from tumor recurrence 8 years and 10 months after initial treatment, phosphorylation constant (K3) and kinetic rCMRGl of the recurring tumor were higher than those of the original tumor. No other tumors have regrown or recurred during the postoperative follow-up periods, which ranged from 22 to 130 months (median = 101 months). Circulation and metabolism measured by PET provide in vivo biological characteristics, including proliferating activity, in oligodendrogliomas.

Adult↗

PubMed1999

11C-methionine uptake to the pancreas and its secretion: a positron emission tomography study in humans.

The aim of this study was to investigate the uptake of [11C-methyl]-L-methionine (11C-methionine) in the human pancreas by analyzing dynamic positron emission tomography (PET) images and the duodenal aspirate. A double-lumen tube was inserted in the duodenum and dynamic PET was performed in seven healthy volunteers for 110 min after intravenous (i.v.) injection of 11C-methionine during the continuous i.v. administration of secretin (125 ng/kg/h) and cerulein (30 ng/kg/h). For the calculation of the radioactivity in the pancreas, the regions of interest were set on the PET images. Radioactivity was measured in 10-min fractions of duodenal juice. After i.v. injection, 11C-methionine accumulated in the pancreas within a few minutes, and the radioactivity plateaued during the study. The radiolabeled proteins in the duodenal juice increased linearly 30 min after 11C-methionine injection, but the relative rates of radioactivity in the protein precipitate to the total count in the duodenal juice were 44-48%. From these findings, it was concluded that 11C-methionine accumulation in the pancreas is very rapid after the i.v. administration, and only a part of methionine uptake to the pancreas is incorporated into secretory proteins. The pancreatic 11C-methionine uptake detected by PET may represent a new aspect of exocrine pancreatic function that has not been expressed by the conventional intubation method.

Adult↗

PubMed1999

Endometriosis and free radicals.

Recent studies have shown that synthase for nitric oxide or scavenger enzymes is distributed throughout the endometrium. We have reported that endothelial nitric oxide synthase, originally identified in vascular endothelial cells, is distributed in glandular epithelial cells in the endometrium, peaking in the midsecretory phase. In addition, it is known that superoxide dismutase is distributed throughout the endometrium, varying with the menstrual cycle. Yet it is not clear how these enzymes are committed in the reproductive processes. Endometriosis is often complicated by infertility and miscarriage. Of particular interest is that these enzymes are overexpressed in the disease throughout the menstrual cycle. These findings strongly suggest that excessive amounts of free radicals are produced in endometriosis. Copyrightz1999S.KargerAG,Basel

Adult↗

PubMed1999

Cerebral blood volume in acute brain infarction: A combined study with dynamic susceptibility contrast MRI and 99mTc-HMPAO-SPECT.

BACKGROUND AND PURPOSE: The aim of this study was to correlate the abnormality in cerebral blood volume (CBV) measured by dynamic susceptibility contrast-enhanced MRI with that in cerebral blood flow (CBF) estimated by single-photon emission CT with [99mTc]hexamethylpropylenamine-oxime in patients with acute ischemic stroke. METHODS: Nine patients with unilateral occlusion of either the middle cerebral artery or the internal carotid artery (4 men and 5 women; mean+/-SD age, 74.4+/-11.6 years) were studied within 6 hours after stroke onset. The relative CBV (relCBV) and CBF (relCBF) in the lesions were defined relative to the contralateral mirror regions. RESULTS: In the brain regions with mild (relCBF >/=0.60), moderate (0.40</=relCBF<0.60), and severe (relCBF <0.40) hypoperfusion, the mean relCBV values were 1.29+/-0.31, 0.94+/-0.49, and 0.30+/-0.22, respectively. The relCBV was significantly elevated in the brain areas with mild hypoperfusion (P<0.001) and significantly reduced in the brain areas with severe hypoperfusion (P<0.001). The relCBF was significantly better than the relCBV in predicting the evolution of infarction (P<0.02). The probability of evolving infarction for the hypervolemic (relCBV >1.0) regions was significantly lower than that for hypovolemic (relCBV <1.0) regions in the relCBF range between 0.40 and 0.50 (P<0.02). CONCLUSIONS: In acute ischemic stroke within 6 hours of onset the CBV can be either increased, normal, or decreased, depending on the severity of hypoperfusion. The increased CBV has a protective effect on evolving infarction. Although the CBF is a better predictor of tissue outcome, the CBV measurement may help detect potentially salvageable brain tissue in the penumbra with compromised blood flow.

Acute Disease↗

PubMed1999

[Phase 2 clinical study of 123I-IBF, a dopamine D2 receptor imaging agent, to evaluate clinical efficacy and safety in Parkinson's disease and Parkinson syndromes].

A Phase 2 multicenter trial of 123I-IBF, (S)-5-iodo-7-N-[(1-ethyl-2- pyrrolidinyl)methyl]carboxamido-2,3-dihydrobenzofuran, was conducted to evaluate its clinical efficacy and safety in 158 patients with Parkinson's disease (PD) or Parkinson syndromes (PS). SPECT data were acquired at two hours (2H-SPECT), after intravenous injection of 123I-IBF (167 MBq). Additional SPECT scan at three hours (3H-SPECT) and dynamic SPECT scan at most until one hour were performed when possible. No severe side effects due to 123I-IBF injection were observed. The sensitivity, specificity and accuracy for discriminating PS from PD using the striatal specific binding count-to-frontal cortex count ratio (St/Fc-1) in 3H-SPECT were 72.7%, 81.0% and 78.1% in 64 clinically definite cases (i.e., typical cases), respectively. The putamen-to-caudate ratios were significantly lower in striatonigral degeneration compared with those in PD. The contralateral-to-ipsilateral ratios against the symptomatic side of tremor and/or rigidity in the patients with PD (Hoehn & Yahr I) were significantly higher than the left-to-right ratios in the normal controls. St/Fc-1 in 3H-SPECT was significantly lower in the patients showing a poor response to levodopa than in those showing a good response. The dopamine D2 receptor binding potential (k3/k4), obtained by dynamic SPECT based on compartment model analysis, correlated well with the striatal specific binding count-to-occipital cortex count ratio. These results suggest that 123I-IBF is a promising agent for differential diagnosis and pathophysiological evaluation of PD and PS.

Adult↗

PubMed1998

Development of a new method for simultaneously evaluating mucociliary clearance and pulmonary epithelial permeability in rabbit experiments by means of 18FDG, three-dimensional positron emission tomography and rectilinear scan.

We tried to simultaneously obtain the elimination constant of mucociliary clearance and the pulmonary epithelial permeability constant after inhalation of 2-[18F]fluoro-2-deoxy-D-glucose (18FDG) solution by carrying out whole lung positron emission tomography and a rectilinear scan in rabbit experiments. The elimination constant of pulmonary epithelial permeability was obtained from the decrease in the amount of the radioactivity with time in the region of interest (ROI) confined to the lungs, trachea and tracheal cannula in the rectilinear scan. The total elimination constant of the radioactivity in the lungs was obtained from the ROI confined to the lungs in the tomography. The mucociliary clearance rate constant in the lungs was then obtained after subtracting the elimination constant of the pulmonary epithelial permeability from the total elimination constant of the 18FDG in the lungs. The mucociliary clearance constant in the trachea was calculated from the residual radioactivity in the trachea and the mucociliary clearance constant in the lungs. The mean pulmonary epithelial permeability constant was 0.0020% min(-1) obtained from the rectilinear scan. The mean mucociliary clearance constants of the lungs and the trachea were 0.0006 and 0.025% min(-1), respectively. These results indicated that the pulmonary epithelial permeability and mucociliary clearance could be evaluated simultaneously with 18FDG by using three-dimensional positron emission tomography and a rectilinear scan.

Administration, Inhalation↗

PubMed1998

[Efficacy of F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scans in diagnosis of pulmonary nodules].

To evaluate the value of F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scans, we performed FDG-PET scans in 23 patients with indeterminate pulmonary nodules less than 3 cm in size and analyzed these scans qualitatively and semiquantitatively. Histologic specimens were obtained by thoracoscopic excisional biopsy in 16 patients, CT-guided needle aspiration cytology in three, and bronchoscopic brushing cytology in four. Pathological diagnoses were lung cancer in 16 patients, benign inflammation in six, and malignant lymphoma in one. Sensitivity, specificity and accuracy of the FDG-PET scans were 88% (15/17), 67% (4/6) and 83% (19/23), respectively. There were two false-positive cases (organizing pneumonia and cryptococcosis) and two false-negative ones (slow-growing adenocarcinoma and malignant lymphoma). Although a few false-positive cases of granulomatous disease were yielded, the FDG-PET scans were highly sensitive in the detection of lung cancer. We conclude that the FDG-PET scanning in a useful diagnostic imaging modailty in the management of indeterminate pulmonary nodules.

Adult↗

PubMed1998

Endothelial nitric oxide synthase in the endometrium during the menstrual cycle in patients with endometriosis and adenomyosis.

OBJECTIVE: To determine the expression of endothelial nitric oxide synthase in the endometrium during the menstrual cycle in endometriosis and adenomyosis. DESIGN: Immunohistochemical identification of endothelial nitric oxide in endometrial tissues using the monoclonal antibody. SETTING: Department of obstetrics and gynecology in a university hospital. PATIENT(S): The subjects were divided into three groups: 35 patients with endometriosis, 33 patients with adenomyosis proven histologically, and 46 fertile controls. MAIN OUTCOME MEASURE(S): Semiquantitative immunostaining (evaluation nomogram) score in endometrial cells. RESULT(S): The analyses revealed phase-dependent changes in the expression of endothelial nitric oxide synthase in the surface and glandular epithelia during the menstrual cycle in the fertile controls. The expression was weakest in the early proliferative phase, gradually increased, was most marked in the midsecretory phase, and decreased thereafter. In contrast, stromal cells did not change throughout the cycle. Contrary to expectations, the expression of endothelial nitric oxide synthase in endometriosis and adenomyosis was persistently greater than the control levels throughout the menstrual cycle. CONCLUSION(S): This study has shown that endothelial nitric oxide synthase is changed in a phase-dependent manner during the menstrual cycle. The exaggerated expression of endothelial nitric oxide synthase in the endometrium throughout the cycle suggests some pathologic role in endometriosis and adenomyosis.

Adult↗

PubMed1998

Cerebral blood flow correlated with carotid blood flow in neurologically normal elderly with severe white matter lesions.

Previous studies of white matter signal hyperintensity (WMSH) on T2-weighted MRI (magnetic resonance imaging) have shown it to be related to decreased cerebral blood flow (CBF). However, there have been few studies on the relationship of WMSH and the internal carotid blood flow (CaBF). Doppler ultrasound sonography is widely used for evaluation of CaBF. We analyzed the relationship between CBF, CaBF, and WMSH. The subjects had not suffered cerebral ischemic episodes although they had some risk factors for stroke. They received MRI and were classified into three groups, i.e. mild, moderate, and severe WMSH. The % stenosis of the internal carotid artery (ICA) was measured with angiography. Doppler sonography was used to measure the mean bilateral CaBF. The oxygen-15 steady-state technique and PET (positron emission tomography) were used to measure CBF. There were significant correlations between the % stenosis of ICA and the ipsilateral CaBF and between the % stenosis of ICA and hemispheric CBF. There was a significant relationship between CBF and CaBF in the severe WMSH group, remaining significant after partialling out of the effects of the % stenosis. This indicated that an atherosclerotic change of the cerebral artery occurred in a way that carotid vascular resistence and cerebrovascular resistence were 'proportional'. Copyright Rapid Science Ltd

Journal Article↗

PubMed1998

Sarcoma botryoides of the uterine cervix: a case report.

Rhabdomyosarcoma of the uterine cervix is a very rare disease. We present a case of rhabdomyosarcoma (botryoide type) arising from the introitus of the uterine cervix, and make a discussion on the diagnosis, treatment and involving factors of prognosis.

Adult↗

PubMed1998

Deposition and clearance of inhaled 18FDG powder in patients with chronic obstructive pulmonary disease.

As freon is limited in its use as a generator for aerosol inhalation, powder particles are used as an alternative for inhalation therapy. The pulmonary deposition and clearance of inhaled powder particles was studied by positron emission tomography (PET) in ten patients with chronic obstructive pulmonary disease (COPD) and in five normal controls. The powder, 5 microm in mean diameter, was water soluble and labelled with 2-deoxy-2-[18F]-fluoro-D-glucose (18FDG). Powder inhalation was done with single deep inspiration from residual volume to total lung capacity. The initial deposition ratio in the right or left lung field to total inhaled dose, measured by an anteroposterior rectilinear scan, did not differ between normals and COPD patients. Ratios of radioactivity detected within the central and peripheral regions (the central to peripheral ratio) measured by the PET scan was not significantly different between COPD patients (4.8+/-2.6, mean+/-SD) and normals (2.6+/-0.8, mean+/-SD). However, the regional powder deposition in peripheral lung fields measured by the PET scan was significantly more uneven in COPD patients than in normal patients. The clearance rate of 18FDG, defined as the retention ratio of 18FDG activity to the initially deposited 18FDG at 60 and 120 min after inhalation, in the trachea, large bronchi or peripheral lung fields measured by tomographic scan showed a wider variation in COPD patients than in normals. To conclude, inhaled powder tended to be deposited more centrally and was distributed more unevenly in the peripheral lung in chronic obstructive pulmonary disease patients than in normals. This could be a limitation of powder inhalation used for therapy in chronic obstructive pulmonary disease patients.

Administration, Inhalation↗

PubMed1998

Parapharyngeal meningioma extending from the intracranial space evaluated by FDG PET.

We report a rare case of parapharyngeal meningioma extending from the intracranial space evaluated by PET with [18F]-2-fluorodeoxyglucose (FDG). Although the parapharyngeal meningioma had a high rate of glucose metabolism, it was proved to be pathohistologically benign. The high rate of glucose metabolism of the tumor reflected tumor aggressiveness well because the tumor grew in a relatively short time.

Aged↗