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Biomedical subjects

Y Inamori

Publications and source records attributed to Y Inamori.

At least 91 records · Page 5Linked to original sources

Bacillus stearothermophilus glyceraldehyde-3-phosphate dehydrogenase as a source of angiotensin-converting enzyme inhibitors.

The more potent inhibitory activity against angiotensin-converting enzyme (ACE) was excised from a glyceraldehyde-3-phosphate dehydrogenase (GAPDH) preparation of Bacillus stearothermophilus by heating at 120 degrees C in 1 M AcOH-20 mM HCl, as compared with GAPDH preparations of yeast and pig. Sufficient excision of B. stearothermophilus ACE inhibitors required a longer proteolysis time of 60 min. Two inhibitors were then purified by gel-permeation and reverse-phase chromatographies. One of the B. stearothermophilus ACE inhibitors BG-1, was the GAPDH peptide 68-77 (Gly-Lys-Glu-Ile-Ile-Val-Lys-Ala-Glu-Arg, IC50: 32 microM). Another inhibitor, BG-2 (Gly-Lys-Met-Val-Lys-Val-Val-Ser-Trp-Tyr, IC50: 6 microM), correspond to GAPDH peptide 304-313. These sequences were quite different from those of vertebrate GAPDH peptides and the venom peptide family with ACE inhibitory activity. BG-2 was found to be a non-competitive type inhibitor, differing from many natural peptide inhibitors. Thus, B. stearothermophilus GAPDH seemed to be a good source of new type ACE inhibitors, in addition to the advantages due to its thermophilic property.

Amino Acid Sequence↗

Determination of beta-lactam antibiotics in water by fluorescence quenching of mercurochrome, and application for simple investigation of potency.

The fluorescence quenching reaction between fluorescein mercury or halogeno-fluorescein mercury compounds (fl. Hg, 2,7- or 2,4-dichloro-fl.Hg, 3',4',5',6'-tetrachloro-fl.Hg, mercurochrome) and beta-lactam antibiotics (ampicillin (AB-PC) and cephalexin (CEX] was investigated, and mercurochrome was selected for the detection of beta-lactam antibiotics; the detection limit was about 0.8 micrograms/ml. A fluorimetric assay of beta-lactam antibiotics was established by measuring the fluorescence of mercurochrome and mercurochrome-beta-lactam antibiotics solutions in weakly basic media to determine the degree of fluorescence quenching. The maximum emission wavelength of mercurochrome solution was at 544 nm with excitation at 470 nm. The calibration graphs were linear over the ranges of about 0-6 micrograms/ml beta-lactam antibiotics penicillins (AB-PC, penicillin G, sulbenicillin, amoxicillin, cyclacillin, oxacillin, hetacillin and piperacillin) and cepham antibiotics (CEX, cefazolin, cephaloglycin, cephaloridine and cefpyramide), and the relative standard deviation was 2.7% for 1.4 micrograms/ml of AB-PC (n = 5). This fluorescence quenching reaction between mercurochrome and beta-lactam antibiotics was applied in a survey of decomposition and remaining potency of beta-lactam antibiotics.

Anti-Bacterial Agents↗

The hypotensive effect and antifungal activity of 3,3'-dihydroxy-alpha,beta-diethyldiphenylethane.

3,3'-Dihydroxy-alpha,beta-diethyldiphenylethane (I), an isomer of hexestrol (II), was found to have a strong hypotensive effect on rats and antifungal activity against some pathogenic fungi. The hypotensive effect of I (-100.0 +/- 21.0 mmHg, 10 mg/kg, i.v.) was stronger than that of II (-40.0 +/- 2.60 mmHg, i.v.). Unlike II and other oxystilbene-related compounds already tested, I showed prolonged hypotensive action at the dose of 10 mg/kg, and the blood pressure was not restored to the original level within 20 min. I also showed antifungal activity against all fungi tested (minimal inhibitory concentration: 10-120 micrograms/ml). It should be emphasized that by shifting the phenolic hydroxyl group to m-position, the biological activities were greatly increased.

Animals↗

Visual identification rate in search of a missing stimulus.

Subjects searched for a digit which was not presented in an array of nine different digits. The identification rate was estimated from the percent correct. Well-trained subjects identified 6.5 digits with a 50-msec. exposure. This fast identification rate was expected from our procedure using a single answer, an inconsistent target, and equal probability that every digit would be a target. Naive subjects markedly improved their performance in the first two weeks of the trials which were given for a total of 24 days.

Adult↗

The histogenesis of DMH-induced colonic carcinoma in rats.

Twenty-one Donryu male rats of six weeks old were injected with 1,2-dimethyl-hydrazine hydrochloride (DMH), once a week, for 4 to 20 weeks, and sacrificed at intervals of two weeks since a lapse of four weeks after the commencement of the injections. The DMH induced 320 atypia lesions, from 0.03 through 20 mm in size, of grade II or higher. The rate of benign lesions was higher in the group receiving less than 20 injections than in the group of 20 injections of DMH, while in the latter group, the rates of the benign, borderline and malignant lesions were stable, suggesting that benign lesions mainly develop in the earlier period of the DMH treatment, and thereafter various grades of lesions develop at a constant rate. All the benign lesions were less than 1 mm in size, and all lesions greater than 1 mm were malignant. In addition, the size of the lesion was significantly greater when it was occupied by malignant crypts in a greater rate. These results indicate that the benign lesions become cancerous before they reach a certain size (adenoma-carcinoma sequence). Twenty-seven minute lesions (less than 1 mm) were mixed lesions of malignant and benign atypia, suggesting that the adenoma-carcinoma sequence is elicited in any size of lesion. On the other hand, there were 41 minute malignant-only lesions, which constituted 27.7% of the overall minute lesions and included three "single crypt" cancers. In addition, malignant-only lesions were smaller when compared to the malignant-dominant mixed lesions. These results indicate that about 30% of colon cancers develop de-novo.

Animals↗