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Biomedical subjects

I Ikeda

Publications and source records attributed to I Ikeda.

At least 163 records · Page 9Linked to original sources
PubMed1987

Heterogeneous distribution of acidic TA-4 in cervical squamous cell carcinoma: immunohistochemical demonstration with monoclonal antibodies.

Tumor antigen TA-4 is divided into two subgroups; acidic and neutral TA-4. The tissue localizations of these TA-4 subgroups were examined by using monoclonal antibodies, i.e., Mab-21 which reacts with both acidic and neutral TA-4, and Mab-317 which is specific to acidic TA-4. Immunohistochemical staining with Mab-21 showed positive cells in most parts of the cancer nest and in the intermediate layer of the non-cancerous squamous epithelium of the uterine cervix, whereas positive staining with Mab-317 was observed only in the cells at the peripheral parts of the cancer nest adjacent to the surrounding stromal tissue. Thus, examination of the subgroups of TA-4 may be a useful aid for investigating the biologic behavior of squamous cells.

Antibodies, Monoclonal↗
PubMed1986

Radioimmunoassay of metanephrine and normetanephrine for diagnosis of pheochromocytoma.

Sensitive and specific radioimmunoassays of metanephrine and normetanephrine were developed by use of 125I-labeled synephrine and specific metanephrine antibody, and 125I-labeled octopamine and specific normetanephrine antibody. Specific antibody for both metanephrine and normetanephrine was raised in rabbits by immunization with bovine serum albumin conjugated with the corresponding hapten, prepared by the method of Grota and Brown (Endocrinology 1976;98:615). The detection limits of the metanephrine and the normetanephrine radioimmunoassays were 2 and 6 pg/tube, respectively. Mean plasma metanephrine and normetanephrine values for 24 normal subjects were 62 (SD 14) and 100 (SD 40) ng/L, respectively. Mean urinary metanephrine and normetanephrine values for 22 normal subjects were 154 (SD 74) and 217 (SD 109) micrograms/day. For 14 pheochromocytoma patients, plasma metanephrine and normetanephrine values ranged from 29 to 683 and from 28 to 7850 ng/L, and urinary metanephrine and normetanephrine values were 606 to 6630 and 296 to 4800 micrograms/day, respectively. The present methods are simple and suitable for routine tests or for mass screening for pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1985

Effects of cycloartenol on absorption and serum levels of cholesterol in rats.

The possibility that cycloartenol magnifies the hypocholesterolemic effect of beta-sitosterol was studied in two strains of rats fed on cholesterol-enriched (0.5%) diets. Cycloartenol was added to diets containing 1.0% or 0.5% beta-sitosterol at the 0.05% level and to diet free of plant sterol at the 0.5% level. In one experiment, diets included sodium cholate (0.125%). Due to the potent hypocholesterolemic efficacy of beta-sitosterol under the present dietary regimens, no clear additional effect (so-called synergistic effect) of cycloartenol was observed. However, in the experiment using Wistar rats, the decrease in serum apo A-I due to feeding cholesterol was ameliorated more effectively in combination with beta-sitosterol than with beta-sitosterol alone. The hepatic deposition of cholesterol was mitigated by dietary beta-sitosterol, and further, although slightly, by a combination of beta-sitosterol and cycloartenol, except in the experiment with diets containing sodium cholate. Fecal excretion of neutral and acidic steroids was not meaningly magnified by cycloartenol. Cycloartenol itself was not as effective as beta-sitosterol in mitigating lipid disorders due to dietary cholesterol. The rate of appearance of cholesterol in the thoracic duct lymph was not interfered with further by a combination of beta-sitosterol and cycloartenol compared to beta-sitosterol alone. This trimethylsterol was absorbed at a rate approximately 4-fold higher than that of beta-sitosterol, though much lower compared to cholesterol. These results suggest a preference for cycloartenol in cholesterol dynamics. However, cycloartenol seems unlikely to influence cholesterol absorption in the small intestine.

Animals↗
PubMed1983

[A simple and direct radioimmunoassay for serum and urinary metanephrine].

A simple, direct and specific radioimmunoassay for serum and urinary metanephrine was developed, in which we used 125I-Synephrine and specific antiserum generated in rabbits by injecting with metanephrine conjugated with bovine serum albumin as described by Grota and Brown. The sensitivity of the assay was 2 pg/tube. Intra- and inter-assay coefficients of variation were 2.6 approximately 7.8% and 5.0 approximately 9.6%, respectively. The recoveries of metanephrine added at two levels of 250 pg/ml and 500 pg/ml to ten serum samples and ten urine samples (hydrolyzed and diluted) were 96.7 and 108% in serum, and 94.8 and 103% in urine, respectively. Normal values of serum metanephrine were 40.3 +/- 25.8 pg/ml (mean +/- SD) from 20 normal subjects. Normal values of 24 hour urinary metanephrine excretion were 12.5 +/- 6.7 ug/day from 24 normal subjects. Serum metanephrine values for 7 patients with pheochromocytoma were 210 approximately 628 pg/ml. Urinary metanephrine values for 9 patients with pheochromocytoma 8.7 approximately 302 ug/day.

Adrenal Gland Neoplasms↗
PubMed1983

Some aspects of mechanism of inhibition of cholesterol absorption by beta-sitosterol.

Mixed bile salt micelle solubilized either cholesterol or beta-sitosterol to a comparable extent. When added simultaneously, beta-sitosterol restricted the micellar solubility of cholesterol. beta-Sitosterol also reduced the cholesterol content in the aqueous (micellar) phase of the intestinal contents of rats, the extent of reduction being comparable with that observed in vitro. The intestinal uptake of cholesterol in vivo was equivalent to the micellar incorporation of cholesterol both in vitro and in vivo. beta-Sitosterol had no inhibitory effect on cholesterol absorption from the micellar solution in jejunal loops in situ, whereas the rate of beta-sitosterol uptake was only about one-fifth that of cholesterol. The intestinal uptake of beta-sitosterol intubated into the stomach of rats was about one-fifth that of cholesterol. The intestinal brush-border membrane discriminated these sterols. These results suggest that the restriction of the micellar solubility of cholesterol, rather than the inhibition of uptake from brush-border membrane, is the major determinant for the interference of beta-sitosterol with cholesterol absorption.

Animals↗
PubMed1983

The contrasting effect of dietary phosphatidylethanolamine and phosphatidylcholine on serum lipoproteins and liver lipids in rats.

The effect of dietary phosphatidylethanolamine (PE) and phosphatidylcholine (PC) added to cholesterol-free semipurified diet on serum lipoprotein and hepatic and fecal lipids was compared to the effect on rats fed soybean oil (controls). The dietary PE, but not PC, caused a decrease in serum cholesterol, phospholipid, apolipoprotein A-I (apoA-I) and apoE and an increase in high molecular weight apoB. The simultaneous addition of PC and ethanolamine also decreased serum apoA-I and cholesterol. The distribution patterns of phospholipid subclasses in the liver and fatty acid composition of hepatic and plasma phospholipids were also altered by dietary PE. Both PE and PC increased to a similar extent the excretion of fecal neutral steroids and hepatic 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity compared to the controls. The present study, therefore, demonstrated for the first time that the PE in the soybean phospholipid preparation is responsible for the alterations of profiles of serum lipids and apoproteins in rats.

Animals↗
PubMed1982

Measurement of plasma renin activity by a simple solid phase radioimmunoassay.

A solid phase RIA in which an antibody adsorbed onto polystyrene balls was developed to determine PRA. Complete inhibition of converting enzyme and angiotensinase during enzymatic reaction was achieved by phenyl methyl sulfonyl fluoride and EDTA combination. Pepstatin A was found to be an effective agent to block angiotensin I generation during the RIA, and the sample can be directly incubated at room temperature for RIA without any special treatment to inhibit renin activity. The intra- and interassay coefficients of variation (CV) were 5.5-6.9% and 3.7-8.2%, respectively. The recovery was 91.9-117% of added angiotensin I. The assay is sufficiently sensitive and reliable for routine use and correlates acceptably (r = 0.996) with an established RIA. The antibody-adsorbed balls were compared to the soluble antibody with respect to thermodynamic parameters. It was found that the apparent equilibrium constant of the antibody-adsorbed ball was reduced to approximately 1/2 sec of soluble antibody, which was predominately due to the decrease in unitary entropy change by adsorption.

Angiotensin I↗
PubMed1982

Effects of beta-sitosterol on the concentrations of serum and liver cholesterol and serum apolipoproteins in rats fed butter fat.

Male rats were fed on semipurified cholesterol-free diets containing butter fat with or without supplementary beta-sitosterol. The expected rise of serum cholesterol caused by butter fat, as compared with safflower oil, was not able to be demonstrated, and hence the hypocholesterolemic effect of beta-sitosterol as well. However, the plant sterol effectively lowered the liver cholesterol level. Similar responses were also observed in mice. The distribution of cholesterol in serum lipoproteins remained unchanged among different dietary regimens. Butter fat increased the concentration of serum apoA-I in relation to safflower oil. There was possibly a trend toward higher serum apoA-I with supplementation of beta-sitosterol in a butter-fat diet. The effect of the plant sterol on serum apoB was rather variable. The observation strongly suggests that alteration in cholesterol metabolism in these rodents may not satisfactorily be estimated by the serum cholesterol parameter alone when diets free of cholesterol are fed. The concentration of hepatic cholesterol and serum apolipoproteins seems a more apposite measure for this purpose.

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↗
PubMed1982

[Gastrin radioimmunoassay with polyethylene glycol method].

125I-labelled gastrin with high immunological activity and high specific radioactivity of 22.2 approximately 25.9 GBq (600 approximately mCi)/mg (0.5 iodine atom/1 gastrin molecule) was prepared by chloramine-T method using the amount of 100 molar ratio of chloramine-T to gastrin. As results of gastrin radioimmunoassay with polyethylene glycol (PEG) method, intra- and interassay coefficient of variation (C.V.) were 3.6 approximately 7.6% and 5.7 approximately 10.4%, respectively. The average recoveries of 2 levels of gastrin added to serum samples were 104 +/- 11.9% and 105 +/- 9.7%. The correlation coefficient of gastrin values obtained with dextrancoated charcoal (DCC) method and present method was r = 0.973. Antibody used in this study have a characteristic to strongly recognize the tyrosin residue at 12 position and the methionyl residue at 15 position on gastrin (1-17).

Antibody Specificity↗
PubMed1981

[A simple solid phase radioimmunoassay for plasma renin activity (author's transl)].

A solid phase radioimmunoassay (RIA) in which plasma renin activity (PRA) can be measured in a single test tube throughout enzymatic reaction and determination of angiotensin-I (A-I) generated was developed. Two hundred micro 1 of plasma samples was incubated with phenylmethylsulfonyl fluoride (PMSF) and ethylenediamine tetraaceticacid (EDTA) at pH 6.0 or 7.4 at 37 degrees C for 1 hr, then the generated A-I was determined by solid phase RIA under 3 hr of incubation time at room temperature. An antibody absorbed onto polystyrene beads was used for B/F separation of RIA. The combination of PMSF and EDTA gave significant inhibition of angiotensinase and converting enzyme. Pepstatin A, proteolytic enzyme inhibitor, was found to be effective to block the renin activity during the incubation for RIA at room temperature. Recoveries of A-I added at two levels of 1.0 4.0 ng/ml to plasma sample incubated at 37 degrees C for 1 hr were 102 +/- 28.6% and 105 +/- 15.2%, respectively. Intra-assay precision (CV) ranged from 2.5 to 10.3% and inter-assay from 7.0 to 13.7% with four pooled sera. PRA obtained under enzymatic reaction of pH 6.0 showed approximately twice as much as that of pH 7.4. The assay correlated closely with the other established solid phase radioimmunoassay kit (r = 0.996). Normal values of PRA were 1.03 +/0 0.78 ng/mg/hr (n = 66) at supine position and 1.33 +/- 1.15 ng/ml/hr at upright position. The method for the measurement of PRA, described in this paper, can be clinically used as one of convenient methods froms its simplicity and reproducibility.

Female↗
PubMed1981

Antihypercholesterolemic activity of beta-sitostanol in rabbits.

The antihypercholesterolemic activity of beta-sitosterol and beta-sitostanol was compared in male rabbits given a cholesterol-supplemented diet. beta-Sitosterol and beta-sitostanol were fed to these rabbits at the 0.5% level with cholesterol (0.5% and 0.2% in experiments I and II, respectively). The serum cholesterol level tended to be lower in rabbits fed beta-sitostanol than in the animals fed beta-sitosterol even in experiment I. The beta-sitostanol exhibited a significantly greater hypocholesterolemic activity in experiment II, LDL-cholesterol being decreased markedly. The liver cholesterol decreased in both groups of rabbits to a similar extent. beta-Sitostanol prevented more effectively the formation of dietary cholesterol-induced atheroma in the abdominal aorta than beta-sitosterol. It is most likely, together with the data reported previously on rats, that the hypocholesterolemic activity of beta-sitostanol results from the significantly greater inhibitory effect on the intestinal absorption of cholesterol than that of beta-sitosterol.

Animals↗