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Biomedical subjects

K Hisada

Publications and source records attributed to K Hisada.

At least 325 records · Page 18Linked to original sources
PubMed1982

Mechanism of tumor and liver concentration of 111In and 169Yb: 111In and 169Yb binding substances in tumor tissues and liver.

Tumor-bearing animals were injected with 111In- and 169Yb-citrate. Tumor homogenates, from which the nuclear fraction was removed, and the mitochondrial fractions of the host livers were digested with pronase P. After digestion, the supernatants of the reaction mixtures were applied to Sephadex G-100 columns. The resultant eluates were analyzed for radioactivity, protein, uronic acid, and sialic acids. Three peaks of radioactivity were obtained by gel filtration. The first peak, eluted in the void volume, contained a species whose molecular weight exceeded 40 000. The second peak consisted of substances with molecular weights of 9400-40 000. Radioactivity in the third peak was liberated 111In and 169Yb. These two nuclides in the second peak were bound to acid mucopolysaccharides and/or the sulfated carbohydrate chain of sulfated glycoprotein. It was thought that the nuclides in the first peak might be bound to some acid mucopolysaccharides. The second peak nuclides seemed to be bound to acid mucopolysaccharide that contained no uronic acids, and/or to the sulfated carbohydrate chain of sulfated glycoprotein. It was concluded that they were bound to the acid mucopolysaccharides and/or the sulfated carbohydrate chain of sulfated glycoprotein in tumor tissues and liver lysosomes.

Animals↗
PubMed1982

Deferoxamine mesylate enhancement of 67Ga tumor-to-blood ratios and tumor imaging.

To improve the tumor-to-blood ratio in 67Ga tumor imaging, the effect of administration of deferoxamine mesylate (DFO) was evaluated. DFO improved 67Ga tumor-to-blood ratios in tumor-bearing rats. Administration of DFO 12 h after 67Ga injection did not decrease the concentration of radioactivity in the tumor of rats, but administration of DFO 4 h after 67Ga decreased the concentration of radioactivity in the tumor. Serum unsaturated iron binding capacity in rats was transiently increased by DFO administration, but when DFO was administered before 67Ga injection the tumor uptake showed rather decreased levels. In human studies, DFO accelerated the excretion of 67Ga from the blood, but tumor images were not necessarily improved.

Animals↗
PubMed1982

A noninvasive method for evaluating portal circulation by administration of Ti-201 per rectum.

A new method for evaluating portal systemic circulation by administration of TI-201 per rectum was performed in 13 control subjects and in 65 patients with various liver diseases. In normal controls, the liver was visualized on the 0--5-min image whereas the images of other organs such as the heart, spleen, and lungs were very poor. In patients with liver cirrhosis associated with portal-systemic shunt, and in many other patients with hepatocellular damage, the liver was not so clearly visualized, whereas radioactivity in other organs, especially the heart, became evident. The heart-to-liver uptake ratio at 20 min after administration (H/L ratio) was significantly higher in liver cirrhosis than in normals and patients with chronic hepatitis (p less than 0.001). The patients with esophageal varices showed a significantly higher H/L ratio compared with that in cirrhotic patients without esophageal varices (p less than 0.001). The H/L ratio also showed a significant difference (p less than 0.01) between Stage 1 and Stage 3 esophageal varices. Since there were many other patients with hepatocellular damage who had high H/L ratios similar to those in liver cirrhosis, the effect that hepatocellular damage has on the liver uptake of TI-201 is also considered. Our present data suggest that this noninvasive method seems to be useful in evaluating portal-to-systemic shunting.

Adult↗
PubMed1982

[Age-matched normal values of regional cerebral blood flow measurements by 133Xe inhalation and production of judgment image: as to initial slope index computed by Fourier analysis].

In order to investigate an influence of advancing age on regional cerebral blood [flow](rCBF), 125 measurements of rCBF were made by 133Xe inhalation method in 90 normal subjects without cerebral symptoms and risk factors of atherothrombotic stroke including hypertension, diabetes mellitus, and hyperlipidemia. There were 46 male and 44 female aged 19 to 80 years old (mean 42.5). The measurements were carried out in a quiet, semi-darkened room with the subjects at rest and eye closed. 133Xe inhalation system (Meditronic-Novo Diagnostic Systems, Inhalation Cerebrograph, Denmark) consists of 32 scintillation detectors, the lateral part of each hemisphere being covered by 16 detectors placed in parallel. One pair of the detectors is mounted in place over the brain stem and cerebellar region. Relationship of age and rCBF computed as the initial slope index (ISI) by Fourier analysis was investigated with both correlation and regression analyses, and age-matched normal values were calculated. End-tidal partial pressure for carbon dioxide (PECO2) was recorded from the face mask during the measurements along with the mean arterial blood pressure (MABP). ISI values were not corrected for changes in PECO2. PECO2 and MABP did not differ significantly among the normal subjects. There were no significant differences in the hemispheric mean ISI values between the right and left hemispheres. Mean brain ISI values showed significant negative correlation with advancing age (r = -0.67, p less than 0.001), and regression line was Y = -0.30X + 67.8. Ninety five per-cent confidence interval of the regression line was +/- 11.8. Regional ISI values also showed significant negative correlations with advancing age in the whole brain (p less than 0.001). There were no significant differences in the correlation coefficients obtained from parallel regions between the right and left hemispheres. The regional reduction of ISI values with advancing age was significantly greater in the regional distribution of the middle cerebral arteries bilaterally, compared with regions in the distribution of either the anterior cerebral, the posterior cerebral, or vertebrobasilar arteries (p less than 0.05). Regional hemispheric percent value of frontal lobe was greater than that of either parietal, temporal, occipital lobe, or brain stem and cerebellar region in the whole age. But, this hyperfrontal distribution became gradually obscured with advancing age, because reduction of ISI values with aging was significantly greater in the frontal than in other regions. It is concluded that measured rCBF of a patient have to be compared with age-matched normal values of mean brain and each region. Judgment image was produced with dividing patient value by 95% confidence limit of age-matched normal value. According to this image, regions in which rCBF significantly decrease or increase can be easily evaluated.

Adult↗