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Biomedical subjects

M Kikutani

Publications and source records attributed to M Kikutani.

16 recordsLinked to original sources
PubMed1986

Pathological study on mucosal changes in small intestine of rat by oral administration of ricin. I. Microscopical observation.

A histological study on small intestine of Wistar rats after oral administration of ricin, a proteinous toxin from castor bean seeds, was carried out. In Experiment I, the jejunum was examined at 1, 2, 5, 10, 15, 20, 24, and 40 hours after oral administration of ricin 30 mg/kg. In Experiment II, ricin was administered at dose of 1, 3, 5, 10, 15, 30, and 60 mg/kg, and after 5 hours the jejunum, mid-portion, and ileum were examined. For comparison, ricin 0.5 mg/kg was administered intraperitoneally and castor bean hemagglutinin (CBH) 30 mg/kg orally. In both experiments, the changes of mucosa were essentially similar dependent on time-lapse and dose respectively, which were atrophy of villus, elongation of crypt, degeneration of epithelium, decrease of goblet cell, fusion of intervillous epithelia, infiltration of neutrophils and eosinophils, and dissociation between epithelium and lamina propria. These changes were most manifest in the jejunum that was contacted with ricin first in a high concentration. In contrast, intraperitoneal administration of ricin caused only dissociation between epithelium and lamina propria and oral administration of CBH caused only milder atrophic changes. The evidences suggest that the mucosal changes by oral administration were caused by direct contact with ricin.

Administration, Oral↗
PubMed1981

[Studies on immunoreactive ACTH from human term placenta. (I) Detection of a high molecular weight-immunoreactive ACTH in term placenta (author's transl)].

Extracts of human term placenta were fractionated by Sephadex G-75 gel filtration and assayed for immunoreactive ACTH. Both high and low molecular weight protein fractions were detected to be immunologically reactive toward anti-human ACTH (1--39 alpha) antibody. For the extraction of low molecular weight ACTH from human term placenta (pl. -ACTH), a glacial acetic acid-acetone mixture was employed, while a pH 3.0-HCl solution was used for high molecular weight immunoreactive ACTH. The high molecular weight immunoreactive ACTH fraction (F-I), co-eluted with horse hemoglobin from a Sephadex G-75.column in 0.1M acetic acid, was essentially devoid of low molecular weight materials as revealed by polyacrylamide gel disc electrophoresis at pHs 9.5 and 4.3. Tryptic digestion of F-1 at pH 8.1 and 37 degrees C for 4 hr with E/S of 1/100, followed by fractionation with a Sephadex G-75, resulted in the formation of lower molecular weight fragments. One fragment was eluted at the same position as that of porcine ACTH with a recovery of 86% of immunoreactivity of F-I. Another fragment which was eluted last exhibited positive beta-endorphin receptor binding activity. These results suggest the presence of a common precursor protein to ACTH and beta-endorphin in human term placenta.

Adrenocorticotropic Hormone↗
PubMed1978

Enzyme immunoassay of human chorionic gonadotropin employing beta-galactosidase as label.

An enzyme-linked immunoassay was applied to the determination of hCG, a glycoprotein hormone usually assayed by RIA. For this purpose, an enzyme hormone conjugate was prepared by reacting hCG with beta-D-galactosidase (beta-Gal.) of E. coli in the presence of N-(m-maleimidobenzoyloxy) succinimide (MBS) as coupling reagent. The conjugate, after purification by affinity and gel chromatographies, was shown to exhibit sufficient enzyme activity and immunoactivity. The immunoassay of hCG was performed by the double antibody method and, using this assay, 0.4-250 mIU/ml hCG were detectable. This was about 10 times as sensitive as the RIA. Difficulty was experienced when this method was utilized for the determination of hCG in plasma samples from patients. Since the presence of the plasma may have affected this assay method, the following improvements were made: 1) the same volume of hormone-free plasma was added to the standard solutions of hCG, and 2) the volume of plasma sample was 10 microliter. The performance and validity of this assay were comparable to the RIA using [125I]hCG as tracer. The dose-response curves of both assay have the same slope and there was no significant difference between the values (correlation coefficient, Y = 0.96X + 1.53).

Acylation↗
PubMed1971

Metabolic effects of the major component of bovine growth hormone.

Bovine growth hormone, subjected to DEAE-cellulose chromatography, yielded one major and several minor components. The various chromatographic fractions of bovine growth hormone were compared with the parent material for their ability to promote hormone effects in vivo and in vitro. The major component of bovine growth hormone was homogeneous by acrylamide-gel electrophoresis, rechromatography and sedimentation equilibrium. Its amino acid composition was similar to that of the parent hormone. The major component possessed all the qualitative activities present in the original heterogeneous material, including promotion of acute hypoglycaemia and hypolipaemia. In studies in vitro in adipose-tissue segments the major component of the hormone increased entry of glucose and its oxidation to CO(2), conversion of glucose into glyceride glycerol, release of glycerol and incorporation of histidine into adiposetissue protein. Other chromatographic fractions of bovine growth hormone were not homogeneous and possessed some but not all of the metabolic activities attributed to the hormone preparations or its major component. Thus, the metabolic effects obtained with bovine growth-hormone preparations in vivo and in vitro can be obtained with the major homogeneous component of the hormone. This observation precludes the possibility that the metabolic effects obtained with bovine growth-hormone preparations are due to the combined actions of a number of components found therein.

Acrylates↗