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J Hatazawa

Publications and source records attributed to J Hatazawa.

At least 145 records · Page 8Linked to original sources
PubMed1990

Effects of co-dergocrine mesylate (Hydergine) in multi-infarct dementia as evaluated by positron emission tomography.

Three female patients aged from 74 to 79 with multi-infarct dementia were studied using positron emission tomography (PET) to assess the effect of co-dergocrine mesylate (Hydergine) on cerebral glucose metabolism. The cerebral glucose utilization (CMRGlc) of each patient was evaluated by PET scan using 2-deoxy-[18F]-2-fluoro-D-glucose (FDG). Following the first PET study, 0.04 mg/kg of co-dergocrine mesylate was injected intravenously with 250 ml saline solution, and then the second PET study was performed. The CMRGlc was determined from the images of the PET scan and the radioactivity of 18F in the plasma. After the administration of co-dergocrine mesylate, the value of CMRGlc increased significantly in the cerebral cortex (p less than 0.01 and p less than 0.05) and basal ganglia (p less than 0.05) compared with values before the administration, but no significant increase was found in the centrum semiovale. These results suggest that co-dergocrine mesylate stimulates glucose metabolism of neurons in the human brain.

Aged↗
PubMed1990

Characteristics of cerebral glucose utilization in dementia.

To make clear the characteristics of cerebral glucose uterization in dementia, PET studies with 18F-FDG were carried out. Taking the pattern of 18F-FDG uterization, dementia can be subdivided into two types. One type shows a simultaneous and symmetrical reduction glucose uterization in the posterior part of neocortex covering the temporal, parietal and occipital association cortices. This is referred to as type I. Although this type constitutes only about 1/5 of all dementia patients, it is considered the fundamental type of dementia. Aside from this, there is type wherein a simultaneous and symmetrical reduction in glucose uterization of the neocortex. This is type II. It constitutes about 4/5 of all dementia patients which is far more type I. There are no essential difference in the characteristics of cerebral glucose uterization in AD and MID. However, with regards the mean, AD is lower than MID. Various organic defect in neocortex do not correlate with the global reduction in glucose uterization in dementia patients. These results suggest that the reduction in glucose uterization in dementia may be functional disorder.

Aged↗
PubMed1990

N-[18F]fluoroacetyl-D-glucosamine: a potential agent for cancer diagnosis.

Positron labeled substrates such as sugars, amino acids, and nucleosides have been investigated for the in-vivo evaluation of biochemical processes in cancerous tissue. Hexosamines are obligatory structural components of many biologically important macromolecules, including membrane glycoproteins and mucopolysaccharide. We evaluated a new synthesized pharmaceutical, N-[18F]fluoroacetyl-D-glucosamine (18F-FAG), which is a structural analog of N-acetyl-D-glucosamine. C3H/HeMsNRS mice bearing spontaneous hepatomas were used for the tissue distribution study. At 60 min after injection, high uptakes were found in tumor (5.16, mean value of %dose/g), liver (3.71), and kidney (3.27). The tumor uptake of 18F-FAG showed the highest value in all tissue. In the PET study, VX-2 carcinoma of the rabbit was clearly visualized. Our preliminary results suggest that 18F-FAG has potential as a new agent for tumor imaging.

Acetylglucosamine↗
PubMed1990

Differential diagnosis of lung tumor with positron emission tomography: a prospective study.

To predict the nature of non-calcifying lung tumors, we performed a prospective study of 46 cases with L-[methyl 11C]methionine (MET, 24 cases) and 18F-fluorodeoxyglucose (FDG, 22 cases) using positron emission tomography (PET). Mean tumor/muscle radioactivity ratios are 5.3 +/- 2.0 (n = 14) for malignant and 1.9 +/- 0.9 (n = 10) for benign with MET (p less than 0.001), and 4.4 +/- 2.2 (n = 12) and 1.5 +/- 0.3 (n = 10), respectively, with FDG (p less than 0.001). The ratios indicate that malignant tumors have higher metabolic demand than benign lesions. Tumors less than 1 cm in diameter were difficult to accurately evaluate due to PET resolution. Compared to the diagnosis at pathology, the MET study showed a sensitivity of 93% (13/14), a specificity of 60% (6/10), and an accuracy of 79% (19/24). The FDG study showed 83% (10/12), 90% (9/10), 86% (19/22), respectively. No significant differences were observed between the two tracers. This study suggests that PET studies using either MET or FDG may be very useful for the differential diagnosis of lung tumors.

Adult↗
PubMed1990

6-[18F]fluoro-L-fucose: a possible tracer for assessing glycoconjugate synthesis in tumors with positron emission tomography.

The potential of 6-[18F]fluoro-L-fucose (6-[18F]FFuc) for assessing glycoconjugate synthesis in tumors with positron emission tomography (PET) was investigated. Using the tissue sampling method with five tumor models, different time-radioactivity profiles were found: a nearly constant level in Lewis lung carcinoma (3LL) and different clearance patterns in others. Rapid clearance in normal tissues resulted in preferable uptake ratios for tumor imaging of brain and pancreas. Metabolic studies and the L-fucose loading effects on the tissue uptake proved the tracer to be a biochemically active L-fucose analog. Imaging of the intracranial rat glioma and 3LL in lungs or hepatomas in mice by autoradiography (ARG) and intramuscular VX-2 carcinoma in rabbits by PET was demonstrated. Using double-radionuclide ARG, similar distribution images of 6-[18F]FFuc and 14C-L-fucose but different tumor-to-liver uptake ratios were found. A metastasis model seemed to show a higher uptake of both tracers as compared to a primary tumor model.

Animals↗
PubMed1989

Metabolic fate of L-[methyl-11C]methionine in human plasma.

The metabolites of L-[methyl-11C]methionine in the plasma of 8 patients with tumors were measured for 60 min after injection. In the plasma, after a rapid clearance, the total radioactivity remained constant, and protein-bound radioactivity increased rapidly. Non protein metabolites detected by HPLC as at least two components besides methionine, increased with time. Significant individual variations for the metabolism were observed. At 60 min after injection, 36.5% (range: 16%-72%) and 45.3% (range: 13%-74%) of the 11C was measured as methionine and labeled proteins, respectively.

Adolescent↗
PubMed1989

Preparation of a fine powder of 2-deoxy-2-[18F]fluoro-D-glucose suitable for inhalation to diagnose lung diseases by means of PET.

Fine 2-deoxy-2-[18F]fluoro-D-glucose (18FDG) powder was obtained by adding diethyl ether into a methyl alcohol solution of 18FDG and other sugar as seed. When micronized particles of sodium N-acetyl-neuraminate (Neu5Ac-Na) were used as seed crystals, particles containing 18FDG were obtained and 80% of them were smaller than 10 microns in size. More than 60% of these crystals were 4-6 microns in size. In a preclinical study of forced inhalation in a dog, the 18FDG fine powder was mainly distributed in the trachea. The radioactivity in the trachea then increased once and a gradual decrease followed. The radioactivity was transferred into the blood and radioactivity incorporation into the heart was observed. After a normal volunteer inhaled 18FDG dry powder aerosol, the radioactivity was found in the respiratory tract and the peripheral area of the lung by means of PET. Absorption and in vivo dynamics of the 18FDG were also analysed.

Administration, Inhalation↗
PubMed1989

Feasibility study of fluorine-18 labeled dopa for melanoma imaging.

Feasibility of fluorine-18 labeled L-dopa for melanoma imaging was investigated. In B16 melanoma-bearing mice given 2-[18F]fluoro-L-dopa, the radioactivity in the B16 decreased for the first 60 min and then remained constant, while all other tissues investigated decreased with time. High tumor uptake ratios for all other tissues except for the pancreas were obtained at 120 min. 6-[18F]Fluoro-L-dopa showed a similar tissue distribution. However, the B16 uptake was about half that value for the 2-fluoro analogue. A higher incorporation rate of 2-[18F]fluoro-L-dopa into the acid-precipitable fraction of the melanoma also showed that the 2-[18F]fluoro-L-dopa was a preferable melanin precursor. Among the four kinds of non-melanoma tumors in mice or rats three tumors showed an uptake of 2-[18F]fluoro-L-dopa similar to the B16 at 60 min. However, larger melanoma-to-tissue uptake ratios were observed when compared to non-melanoma tumors.

Animals↗
PubMed1989

Computed tomography, magnetic resonance imaging, positron emission tomography and evoked potentials at early stage of adrenoleukodystrophy.

An 8 year-old-boy with adrenoleukodystrophy (ALD) was subject to an x-ray computed tomography (CT) scan, magnetic resonance imaging (MRI), positron emission tomography (PET) using 18F-fluorodeoxy glucose and evoked potential studies, about 3 months after the onset of neurologic symptoms. A CT showed decreased radiodensity over the white matter of both occipital lobes, and high density areas on the periventricular space. No contrast enhancement was observed around the low dense white matter, while occipital grey matter seemed to be almost normal. MRI demonstrated a larger and more obvious lesion of prolonged T2 relaxation time which was 170-250 msec than that detected by CT scan. The PET demonstrated wide and severe hypometabolism for glucose over the grey and the white matter of bilateral occipital lobes. The visual evoked potential (VEP) was scarcely elicitable, while the auditory brainstem response (ABR) and short latency somatosensory evoked potential (SSEP) was normal. These imaging studies suggest that extensive and profound demyelination exists in the occipital white matter. For detection of demyelinizing process, MRI may be more effective than CT in this disorder. The PET study revealed that there may have been an abnormality of the grey matter as well as the white matter in the occipital lobe. The VEP disappeared in the relatively early stage. The brainstem may not be involved at such early stage in light of normal ABR and SSEP.

Adrenoleukodystrophy↗
PubMed1989

[Double tracer whole body autoradiography using a short-lived positron emitter and a long-lived beta emitter].

We investigated glucose and amino acid metabolism in tumors and other organs using whole body autoradiography with a short-lived positron emitter and a long-lived beta emitter. The radioactive compounds used were 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) with a half life of 109.8 min and L-[methyl-14C]-methionine (14C-MET) with a half life of 5,730 years. A Donryu rat weighing about 150 g was subcutaneously inoculated at the back with experimental tumors of AH109A and AH272. 74 MBq (2 mCi) of 18F-FDG and 740 kBq (20 microCi) of 14C-MET was administered and after 30 min, the rat was sacrificed. Whole body frozen sections were obtained using autocryotome. For the 18F-FDG autoradiogram, the frozen sections were exposed to an X-ray film for 6 h. After seven days, these frozen sections were again exposed to 14C-MET for a week. Cross-contamination was minimized by adjusting the exposure time, the interval of exposures and the administered dose. The accumulation of the tracers was represented as the optical density ratio of the tissue of interest to the muscle. The tumor ratios were 12.5 for 18F-FDG and 8.6 for 14C-MET showing the highest accumulation in the whole body autoradiogram. In contrast the inflammatory tissue ratios were 1.27 for 18F-FDG and 0.77 for 14C-MET showing very low amino acid metabolism. With the present double tracer whole body autoradiogram, 18F-FDG accumulation was seen in the brain and the heart but not to the liver as against 14C-MET accumulation which was seen to the liver but not to the brain and the heart.

Animals↗
PubMed1989

Relationship between histologic type of primary lung cancer and carbon-11-L-methionine uptake with positron emission tomography.

L-[Methyl-11C]-methionine [( 11C]methionine) has proved to be one of the useful amino acids for the diagnosis of human cancer. We examined whether there was any correlation between [11C]methionine uptake and histologic type of primary lung cancer. Sixteen patients with nine squamous cell carcinoma, five large cell carcinoma, one small cell carcinoma, and one adenocarcinoma were studied using positron emission tomography (PET). All patients had high accumulation of [11C]methionine in lung tumors. We evaluated [11C]methionine uptake into the tumor by a semiquantitative value, DUR (Differential Uptake Ratio). There was significant difference (p less than 0.01, Mann-Whitney test) of [11C]methionine uptake between large cell carcinoma (3.98 +/- 0.27) and squamous cell carcinoma (2.92 +/- 0.30). The result suggested that there was correlation between [11C]methionine accumulation and the histologic type of lung cancer. This indicates a new potential applicability of [11C]methionine PET for the study of lung cancer.

Adenocarcinoma↗
PubMed1989

D2-dopamine receptor specific brain uptake of carbon-11-labeled YM-09151-2.

The in vivo D2-receptor specific brain uptake of N-[(2RS,3RS)-1-benzyl-2- methyl-3-pyrrolidinyl]-5-chloro-2-methoxy-4-[11C]methylaminobenzamide ([11C]YM-09151-2), was investigated. In rat brain the high uptake of [11C]YM-09151-2 in striatum was displaced with sulpiride, spiroperidol, and YM-09151-2. SCH-23390 and ritanserin, D1-dopamine and S2-serotonin antagonists, showed no effect on the distribution of [11C]YM-09151-2. In the striatum at 60 min, 95% of the radioactivity was detected as [11C]YM-09151-2 by high performance liquid chromatography. On the other hand, 41% of 11C in the plasma at 60 min was observed as metabolites. In vivo autoradiography showed a high uptake of [11C]YM-09151-2 in the striatum and in the nucleus accumbens of rat brain. A high uptake of radioactivity was also found in the canine basal ganglia with positron emission tomography. The uptake was reduced by pretreatment with spiroperidol. The present results demonstrate that [11C]YM-09151-2 is a D2 receptor specific compound and is a potential in vivo tracer for measuring D2 receptors.

Animals↗
PubMed1989

[Cerebral glucose metabolism in dementia (PET-FDG study)].

Positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) was employed to assess regional cerebral glucose metabolism which is tightly coupled to neuronal activity in the brain. In Alzheimer's and multi-infarct dementia, hypometabolism of glucose was found in frontal, temporal, and parietal association cortices. Focal hypometabolism in association cortices was observed in depression, epilepsy, ALS and other neurological diseases without any symptoms of mental deterioration. These results might indicate that not focal but global decrease of neuronal activity in the association cortex induces demented state.

Adult↗
PubMed1989

Quantitative evaluation of L-[methyl-C-11] methionine uptake in tumor using positron emission tomography.

Tumor uptake of L-[methyl-11C]methionine ([11C]Met) was assessed in six patients with brain tumors and three patients with lung cancer using positron emission tomography (PET). In arterial plasma samples taken at 5, 15, 30, and 60 min after injection, a fraction of [11C]Met was measured using high performance liquid chromatography in individual patients. Employing curve fitting, a history of [11C]Met activity was obtained as an input function. By means of sequential PET scannings and graphic analysis, uptake rate and distribution volume of [11C]Met in tumor tissue were calculated. In two studies irreversible uptake into the tumors was not seen when total plasma 11C activity was used as the input; however when [11C]Met plasma activity was used, definite irreversible uptake was seen, indicating tumor viability. In other studies, up to 24% underestimation of uptake rate was found. The present results demonstrated the importance of measuring [11C]Met in plasma for quantitative assessment of in vivo amino acid metabolism in tumors.

Adolescent↗
PubMed1988

Positron CT imaging of an impending stroke.

We present PET findings of a case of a transient ischemic attack which later progressed to cerebral infarction. Cerebral blood flow at the stroke focus in the right parietal cortex measured after a TIA attack and before stroke was as low as 24 ml/100 g/min with some increase in oxygen extraction fraction and blood volume. The condition was compatible with "misery perfusion". This case may be an example suggestive that the "misery perfusion sign" is a warning of impending stroke and its poor prognosis if left without appropriate treatments.

Aged↗
PubMed1988

Measurement of the ratio of cerebral oxygen consumption to glucose utilization by positron emission tomography: its consistency with the values determined by the Kety-Schmidt method in normal volunteers.

The regional interrelationship between cerebral oxygen consumption (CMRO2) and cerebral glucose utilization (CMRGlc) was studied in normal subjects using positron emission tomography (PET) and the 15O steady-state inhalation and the [18F]fluoro deoxyglucose method. The use of standard sets of rate constants and the model lumped constant of 0.52 as well as the regional blood-brain partition coefficient for water and the blood volume correction for oxygen extraction fraction provided a CMRO2/CMRGlc ratio of 4.89 in the cortical gray matter, 5.27 in the basal ganglia and 5.82 in the centrum semiovale (white matter). The values of CMRO2/CMRGlc for the basal ganglia and the white matter were consistent with those reported for the whole brain with the Kety-Schmidt method. There was no significant difference in the CMRO2/CMRGlc between the basal ganglia and the white matter indicating the similar nature of in vivo oxidative metabolism of glucose in neuron-rich region and glial cell-rich region.

Aged↗