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Biomedical subjects

T Ido

Publications and source records attributed to T Ido.

At least 235 records · Page 13Linked to original sources
PubMed1981

[The development of the apparatus for the fully automated synthesis of short-lived radiopharmaceutical. --13NH3 automated automated synthesis (author's transl)].

A fully automated apparatus for repeated production of 13NH3 from proton-bombarded water has been developed. Its operation sequence consists of the introduction of NaOH, the bombarded water containing 13NO3- and TiCl3 into a reaction vessel, the distillation of 13NH3 formed by the reduction of the 13NO3-, and the washing of the vessel for the next sequence. The NaOH and TiCl3 are added as 4 ml of saturated solution and 4 ml of 10% aqueous solution, respectively, and halogen lamps are used as the heat source for the distillation. By this apparatus, 13NH3 can be produced automatically and repeatedly in a radiochemical yield of 80-90% within 10 min from the EOB.

Ammonia↗
PubMed1980

[Clinical study of adrenal imaging with 123I-labeled-6 beta-iodomethyl-19-norcholesterol (author's transl)].

Although adrenal scintigraphy with 131I-6 beta-iodomethyl-19-norcholesterol (NCL-6-131I) was used for the first noninvasive imaging of the adrenal glands, it has the disadvantages. These are: (i) relatively high radiation dose to patients, (ii) the long time required for completion of the scan. To solve these problems, 123I-labeled 6 beta-iodomethyl-19-norcholesterol (NCL-6-123I) was synthesized and was used for adrenal scintigraphy in 6 cases. Successful images were obtained with 185 MBq (5 mCi)-260 MBq (7 mCi) of NCL-6-123I, and optimal time required for the satisfactory scan was 2-3 days after the administration. The estimate radiation dose was reduced by using 185 MBq (5 mCi) of NCL-6-123I instead of 18.5 MBq (0.5 mCi) of NCL-6-131I. From the result of this clinical study, NCL-6-123I was preferred for the adrenal scintigraphy.

Adosterol↗
PubMed1980

Anhydrous F-18 labeled eslemental flurine for radiopharmaceutical preparation.

Interest in fluorine- 18 as a label in radiopharmaceutical studies has led to the development of a method for the production of decicuries of anhydrous 18F-F2 using the 20Ne(d, alpha) 18F reaction. The amount of anhydrous 18F-F2 that can be removed from the target is a function of target pressure and carrier cokncentration increasing with rising target pressure and decreasing with decreasing carrier concentration. At a target pressure of 24 atmospheres and a carrier concentration of 0.1% F2, nearly 95% of the theoretical yield of fluorine- 18 produced can be removed and up to 85% delivered through a 10o-m stainless steel tube to the reaction chamber. Other functions affecting yield--including target design, target-gas handling and purity--have been addressed. Thick target yields for 14.0- and 9.4-MeV deuterons on target were measured to be 82 and 67 mCl/microA at saturation. With the BNL 60-in. cyclotron, production okf 600-800 mCl of 18F-F2 with a specific activity of approximately 10 mCi/mumole has been in effect since 1976.

Fluorine↗
PubMed1979

The [18F]fluorodeoxyglucose method for the measurement of local cerebral glucose utilization in man.

A method has been developed to measure local glucose consumption in the various structures of the brain in man with three-dimensional resolution. [18F]-2-deoxy-2-fluoro-D-glucose is used as a tracer for the exchange of glucose between plasma and brain and its phosphorylation by hexokinase in the tissue. A mathematical model and derived operational equation are used which enable local cerebral glucose consumption to be calculated in terms of the following measurable variables. An intravenous bolus of [18F]-2-deoxy-2-fluoro-D-glucose is given and the arterial specific activity monitored for a predetermined period of from 30 to 120 minutes. Starting at 30 minutes, the activity in a series of sections through the brain is determined with three-dimensional resolution by an emission tomographic scanner. The method was used to measure local cerebral glucose consumption in two normal volunteers. The values in gray matter structures range from 5.79 mg/100 g per minute in the cerebellar cortex to 10.27 in the visual cortex, whereas, in white matter structures, the values range from 3.64 mg/100 g per minute in the corpus callosum to 4.22 in the occipital lobe. Average values for gray matter, white matter, and whole brain metabolic rates, calculated as a weighted average based on the approximate volume of each structure, are 8.05, 3.80, and 5.90 mg/100 g per minute, respectively. The value of 5.9 mg/100 g per minute compares favorably with values previously reported.

Adult↗
PubMed1978

[Simple method for producing 13NN and 15OO by proton bombardment of aqueous phase (author's transl)].

A simple method has been developed for the production of 13NN and 15OO by proton irradiation of aqueous solutions. 90 mCi of 13NN was obtained in a 200 ml. of He by using 1.0M NH4CI solution at pH 11 as the target with 10 min irradiation of 15 MeV, 10 microamperemeter protons. 80 mCi/min of 15OO was continuously obtained in a 200 ml of O2 by using pure water as the target with 40 MeV, 2 microamperemeter protons. The radiochemical purity of these short-lived radioactive gases obtained by this method was greater than 99.9% by passing through a single absorber.

Ammonium Chloride↗
PubMed1978

[Caffeine-11C, ephedrine-11C and methylephedrine-11C: Synthesis and distribution in mice (author's transl)].

Caffeine, ephedrine and methylephedrine were labeled with carbon-11 by the action of methyliodide-11C on theophylline, norephedrine and ephedrine, respectively. Caffeine-11C was prepared in 44 min with a radiochemical yield of 40%, ephedrine-11C in 45 min with a 11% radiochemical yield and methylephedrine-11C in 36 min with a 43% radiochemical yield. When injected in mice intravenously, these products show a high uptake in the liver, the kidney and the blood for caffeine-11C and in the liver and the kidney for ephedrine-11C and methylephedrine-11C. The brain uptake for these products was found to be 2.4 to 3.9% of the injected dose per gram at 5 min after injection. These studies in mice have demonstrated that these products are potentially useful agents for the dynamic studies of the brain.

Animals↗
PubMed1977

[Remote system for the mass production of short-lived radioisotopes in a cyclotron. Development of the system and radioisotope production].

A system was developed for producing short-lived radioactive substances (11CO, 11CO2, 13NN, 13NH3, 18F-, 62Zn2+, 123I-, etc.) on a scale enough for clinical use, which could also be used for analyzing them rapidly and for investigating their production methods, with less received dose by workers. The system enabled us to produce remotely several tens mCi of of short-lived radioactive susbtances readily usable for clinical diagnosis, continuosly for radioactive gases, 11CO, 11CO2 and 13NN, or repeatedly at short intervals for radioactive aqueous solutions of 13NH3, 18F-, etc. Employing this system, the average received dose per month was reduced considerably.

Carbon Radioisotopes↗
PubMed1977

Radiopharmaceuticals XXVII. 18F-labeled 2-deoxy-2-fluoro-d-glucose as a radiopharmaceutical for measuring regional myocardial glucose metabolism in vivo: tissue distribution and imaging studies in animals.

18F-2-Deoxy-2-fluoro-D-glucose (18FDG) is rapidly extracted by the mouse heart, and the radioactivity in heart (3-4% per organ) remains relatively constant for 2 hr post injection. The brain uptake (2-3% per organ) remained relatively constant throughout the time course of the study. Liver, lungs, kidneys, small intestine, and blood all showed a rapid clearance of radioactivity after injection of 18FDG. At 120 min the heart-to-lung ratio was 12 and heart-to-liver ratio was 32. Urinary excretion of activity was approximately 16% of the injected dose at 60 min. The uptake of radioactivity by dog heart following the intravenous administration of 18FDG was 2.8-4.1% at 60 min and 2.4% at 135 min; it was regionally distributed, the areas of highest activity being the left ventricle and the interventricular septum. The brain activity was 2.1-3.5% at 120 min, with a ratio of gray matter-to-white matter of 2-3:1. Urinary excretion in dogs was 16% and 50% of the injected dose at 60 and 135 min. The chemical form of the activity in the urine, although unidentified, was not 18F-. Cross-sectional images of the myocardium of the dog after intravenous injection of 18FDG were obtained using emission tomography.

Animals↗
PubMedDate not supplied

Cerebral glucose metabolism in five patients with Lennox-Gastaut syndrome.

Regional cerebral glucose metabolic rates were estimated by positron emission tomography, in parallel with electroencephalography and cranial computed tomography in 5 patients with Lennox-Gastaut syndrome. The 5 patients, 3 boys and 2 girls, ranged in age from 10-15 years. Computed tomography revealed no gross abnormalities. Each patient received 2-5 mCi of 2-(18F)-fluoro-2-deoxy-D-glucose (18F-FDG) intravenously. Averaged cerebral glucose metabolic rates were reduced in each cerebral region as compared with controls. Unilateral hypometabolism was present in 4 patients: one in the inferior frontal gyrus as well as the posterior portion of the superior temporal gyrus; one in the inferior frontal gyrus; one in the posterior portion of the superior temporal gyrus; and one demonstrated diffuse hemispheric hypometabolism including the inferior frontal and posterior portion of the superior temporal gyrus. The side of hypometabolism was the same as the epileptogenic focus on the electroencephalogram. No focal changes were demonstrated on the electroencephalogram of a patient whose positron emission tomography revealed hemispheric hypometabolism. Hypometabolism of the inferior frontal and posterior portion of the superior temporal gyrus may relate to the possible pathogenesis of Lennox-Gastaut syndrome. Positron emission tomography has the potential to reveal a latent focal or lateralized abnormality in some patients with non-localized electroencephalographic changes.

Blood Glucose↗
PubMedDate not supplied

Differential diagnosis of solitary pulmonary nodules with positron emission tomography using [11C]L-methionine.

Two patients with solitary pulmonary nodules, 1.5-2.0 cm in diameter, were studied by positron emission tomography using [11C-Methyl]L-methionine (11C-Met). Case 1 showed high accumulation of 11C-Met in the tumor, and a tumor/muscle ratio of 6.0 suggesting malignancy. Tissue obtained by biopsy revealed a squamous cell carcinoma. Case 2 showed nonspecific isotope accumulation in the tumor, and a tumor/muscle ratio of 1.2 suggesting a benign lesion. Lung biopsy demonstrated granuloma. Positron emission tomography with 11C-Met seems to be useful for the differential diagnosis of solitary lung nodules.

Aged↗
PubMedDate not supplied

Tracheobronchial mucociliary clearance and alveolar epithelial permeability measured by PET with 18FDG powder.

Tracheobronchial mucociliary clearance and alveolar permeability were measured with positron emission tomography using a water-soluble dry aerosol, sodium-N-acetyl-neuraminate tagged with 2-deoxy-2-[18F]fluoro-D-glucose (18FDG powder). Five normal volunteers inhaled 1.5-2.0 mCi of FDG powder by a single deep breath. The distribution of radioactivity, measured by scanning during a period of 120 min, showed that the 18FDG powder deposition progressed from the central airways to the peripheral alveolar areas. In the tracheobronchial system the radioactivity decreased to 24% of the initial deposition at 60 min. In the peripheral alveolar area, where absorption into blood or lymphatic flow crossing the epithelial layer represents a unique mechanism of clearance for water-soluble 18FDG powder, alveolar radioactivity decreased slowly to approximately 70% of the initial deposition at 60 min after inhalation. Positron emission tomography using 18FDG powder provides a regional evaluation of both mucociliary transport in the tracheobronchial system and epithelial permeability in the alveolar area.

Absorption↗