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Biomedical subjects

O Inoue

Publications and source records attributed to O Inoue.

At least 217 records · Page 12Linked to original sources
PubMed1982

Preparation of 18F-labeled 6- and 2-fluoro-9-benzylpurine as a potential brain-scanning agent.

The preparations of [18F]-6-fluoro-9-benzylpurine(I) and [18F]-2-fluoro-9-benzylpurine(II) are described. (I) was prepared by two methods: (i) halogen exchange of 6-chloro-9-benzylpurine with Ag 18F; and (ii) displacement of trimethylpurin-6-ylammonium chloride with K 18F, followed by 9N benzylation. The latter labeling method was far superior to the former, both in radiochemical yield and in specific activity. (I) was relatively stable in a Tris-HCl buffer (0.4 M, pH 7.6) at 37 degrees C, but was easily hydrolyzed in 1 N HCl. Biodistribution of (I) in mice demonstrated high uptake in the brain. (I) can be expected to be a potential brain-scanning radiopharmaceutical for positron computed tomography.

Animals↗
PubMed1982

Evaluation of two different HEDP content kits: stability study against dilution both in vivo and in vitro.

Two different HEDP content kits (Kit A, HEDP: 1 mg, SnCl2. 2H2O: 0.5 mg; and Kit B, HEDP: 10 mg, SnCl2. 2H2O: 0.5 mg) were evaluated for their stability against dilution 99mTc-HEDP solutions prepared from these two kits were diluted from 10 to 6000fold with 0.9% NaCl solution just before evaluation both in vivo and in vitro. In the case of Kit A, significant soft tissue uptake in vivo and released free pertechnetate in vitro were observed by diluting the 99mTC-HEDP solution. On the other hand, 99mTc-HEDP prepared from Kit B was found to be sufficiently stable against dilution. The stability after preparation of each diluted 99mTc-HEDP was also greatly affected by its HEDP concentration. Preliminary analysis of absorption spectra for each 99Tc-HEDP indicated the possibility of two different 99mTc-HEDP complex formation by varied HEDP concentration. These results indicated that a cold reagent like Kit A might cause a higher soft tissue uptake due to its dilution in vivo during a clinical study for bone scanning.

Animals↗
PubMed1982

In vitro and in vivo behaviour of four different 99(m)Tc-HEDP complexes.

According to absorption spectra, at least four different 99Tc-HEDP complexes [complex I (colorless), complex II (yellow), complex III (pink-red) and complex IV (brown)] were observed under various labeling conditions. Both pH and Sn (II)-HEDP concentration greatly influenced the formation of these complexes. In acidic or neutral media, complex II was the main product while in alkaline media complex III and complex IV were formed below concentration levels of 1 X 10(-3)M of Sn (II) and of 3 X 10(-3)M of HEDP. At high Sn (II)-HEDP concentrations complexes I and II were formed, while complexes III and IV were found at lower Sn (II)-HEDP concentrations in weak alkaline media. All four 99(m)Tc-HEDP complexes were stable against air oxidation until at least 6 hrs after preparation. Complexes I and II were stable against dilution by distilled water, while complexes III and IV were unstable and readily dissociated. In organ distribution studies high soft-tissue uptakes were observed with complexes III and IV, while complexes I and II had high bone-seeking properties.

Animals↗
PubMed1977

Preparation of various Tc-99m dimercaptosuccinate complexes and their evaluation as radiotracers.

The organ distributions of four different Tc-99m dimercaptosuccinate complexes ("Tc-DMS", Complexes 1 to 4) were determined using mice and were evaluated as renal imaging agents. The highest kidney uptake was observed with Complex 2:21.7% of dose, 3 hr after injection. The biologic distributions and gel chromatographic analyses using carrier Tc-99 and Sn-113 indicate that there is little possibility of mixed metal complexes of the type Tc-Sn-DMS: rather they contain only Tc + DMS. The labeling procedure for Tc-99m DMS as a renal agent proceeds in two steps: a rapid formation of Complex 1, and a slower, rate-determining step from Complex 1 to Complex 2. A reproducible lyophilized kit has been prepared. The yield of complex 2 greatly depends on the reconstitution volume of 99mTcO4-; yield averages 89% using 2 ml of 99mTcO4-eluate.

Animals↗
PubMed1976

New preparation method for 99mTc-phytate.

A new method is described in which Pt-Sn or Sn-Sn electrodes are used to activate 99mTcO4-. The 99mTc is incorporated into phytic acid by stannous ion released from a tin anode by the corrosive reaction. The most suitable pH for labeling phytic acid by this method was below 5 and the 99mTc-phytate formed could be precipitatedd with Ca+2 at a pH above 3.5. Though 99mTc-phytate is soluble in aqueous solution, it forms an insoluble species with Ca+2 in vivo and is trapped in the reticuloendothelial system. More than 93% of the 99mTc-phytate localized in the liver of mice; here its biologic half-time is about 112 hr. The 99mTc-phytate prepared by this method promises to be useful as a liver-scanning agent. Since our method does not require an applied electric potential, it appears to be one of the most convenient methods for labeling compounds with 99mTc.

Animals↗
PubMed1969

[Dementia].

Explore the source record for details and available documents.

Dementia↗
PubMedDate not supplied

Noninvasive evaluation of systolic pressures of pulmonary artery and right ventricle using contrast-enhanced doppler echocardiography: comparative study using sonicated albumin or glucose solution.

Evaluation of pulmonary arterial pressure is essential for the diagnosis and management of patients with congenital heart disease; it is usually done by cardiac catheterization. An alternative, noninvasive method may be clinically more useful. The purpose of this study was to assess the usefulness of the noninvasive determination of systolic pressure of the pulmonary artery and right ventricle by contrast-enhanced Doppler echocardiography. We selected 30 pediatric patients (28 with trivial or nonsignificant tricuspid regurgitant Doppler signals and 2 with significant tricuspid regurgitant Doppler signals) aged 2 months to 21 years. The flow velocity of tricuspid regurgitation was measured with continuous-wave Doppler of the right ventricular inflow view or left parasternal or apical four-chamber view before and after injection of two types of contrast medium (hand-agitated 5% glucose or sonicated albumin). The systolic pressure of the pulmonary artery was assessed as the estimated right ventricular systolic pressure (albumin method) minus the peak pressure gradient across the pulmonary valve (nonenhanced Doppler method). After injection of hand-agitated 5% glucose and sonicated albumin, trivial tricuspid regurgitation signals were enhanced in 25 of 28 patients (89%). In two patients, spectral envelopes were well defined enough to obtain the peak systolic velocity of the tricuspid regurgitation jet without contrast medium injection. Peak velocity was not altered by injection of contrast medium in these patients. There was significant correlation between the estimation by contrast-enhanced Doppler using hand-agitated 5% glucose and the cardiac catheterization measurement of the transtricuspid pressure gradient (r = 0.88). The transtricuspid pressure gradients obtained by continuous-wave Doppler during sonicated albumin enhancement corresponded closely to those measured by cardiac catheterization (r = 0.95). Pulmonary arterial and right ventricular systolic pressures measured by Doppler using sonicated albumin and those obtained by cardiac catheterization were highly correlated (right ventricle, r = 0.96; pulmonary artery, r = 0.95). In conclusion, this technique may be a valuable noninvasive method for determining accurate right ventricular and pulmonary arterial systolic pressures.

Adolescent↗
PubMedDate not supplied

Therapeutic ethanol injection of hepatocellular carcinomas undetectable by angiography and Lipiodol computed tomography.

Seven smaller than 2 cm in diameter hepatocellular carcinomas (HCC) undetectable by hepatic arteriography and computed tomography (CT) after intraarterial injection of iodized oil (Lipiodol CT) were diagnosed by ultrasonography-guided fine-needle biopsy in 6 patients. All lesions were treated by percutaneous ethanol injection (PEI) in 1-3 weekly intervals. No recurrences have been demonstrated after 7-15 months. The treatment of HCCs undetectable by angiography and Lipiodol CT presents a problem as transcatheter arterial embolization is considered ineffective due to poor vascularity. PEI appears to be an excellent treatment for these small HCCs.

Aged↗