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Biomedical subjects

S Katayama

Publications and source records attributed to S Katayama.

At least 487 records · Page 27Linked to original sources
PubMed1978

Specific cleavage of reduced and S-carboxamidomethylated neurophysin II by the collagenase of Clostridium histolyticum.

Purified collagenase of Clostridium histolyticum was shown to cleave reduced and S-carboxamidomethylated bovine neurophysin between Cys-13 and Gly-14. The scission resulted in formation of two separable fragments: a smaller peptide arising from residues 1 through 13, and a larger peptide comprising the remainder of the residues of the protein. By dansylation procedures, the smaller peptide was shown to have amino-terminal alanine as expected from the sequence of neurophysin II, and the larger peptide had amino-terminal glycine as anticipated. These results show that collagenase indeed cleaves bovine neurophysin II in accord with the specificity postulated for that enzyme, i.e., scission between -X-Gly- in a sequence of -Pro-X-Gly-Pro-Y-. This result, obtained with a non-collagenous protein substrate, is further confirmation of the specificity of collagenase as established by its action on collagens and on synthetic oligopeptides.

Amino Acids↗
PubMed1978

A new method for extraction of extravasated dye in the skin and the influence of fasting stress on passive cutaneous anaphylaxis in guinea pigs and rats.

A method for quantitative extraction of extravasated dye from the skin was studied in guinea pigs and rats. A simple method with a low cost and good recovery was established as follows; A piece of the skin containing extravasated dye was soaked overnight in a stoppered glass tube containing 1 ml of 1 N KOH at 37 C. Then, 9 ml of mixed solution of 0.6 N H3PO4 and acetone (5:13) was added to the tube. The tube was shaken vigorously for a few seconds and centrifuged at 3,000 rpm for 15 min. Absorbance of supernatant was measured at 620 nm. The recovery rate of the dye was about 95 per cent both in guinea pigs and rats. Using this method we observed that fasting stress significantly reduced the intensity of skin reaction induced by chemical mediators, heterologous PCA and especially homologous PCA in guinea pigs.

Acetone↗
PubMed1978

[Experimental asthma in rats, and the effect of N (3', 4'-dimethoxycinnamoyl) anthranilic acid (N-5') (author's transl)].

Although guinea pigs have been frequently used as a model of asthma, antibodies produced in this species are generally gamma1 and gamma2 and belong to IgG. The antibody responsible for asthmatic attacks in humans is IgE, and such is quite different from gamma1 and gamma2, immunologically. Guinea pigs are not therefore an adequate model for investigating anti-asthmatic drugs which inhibit IgE-mediated mediator release, such as disodium cromoglycate. On the other hand, rats do produce an antibody similar to human IgE, the so-called homocytotropic antibody (HTA), by sensitization with dinitrophenylated ascaris extract (DNP-As) together with killed Bordetella pertussis as an adjuvant. To rats actively sensitized with DNP-As or passively sensitized with HTA serum against DNP-As, intravenous administration of antigen did not produce a transient increase in respiration (unlike that of guinea pigs) immediately after the antigen treatment, but a respiratory disorder similar to that seen during asthmatic attacks in humans did occur. The response to antigen was reproducible in passively sensitized rats compared with that of actively sensitized ones, though the symptom was moderate. The effect of N(3', 4'-dimethoxycinnamoyl) anthranilic acid (N-5'), a new anti-allergic drug, was determined in cases of experimental asthma in passively sensitized rats. Respiratory disorders as a result of antigen were clearly inhibited with oral administration of this agent.

Animals↗
PubMed1977

Ultrastructural study of thyroid medullary carcinoma.

This study deals with 11 cases of thyroid medullary carcinoma of which 7 were familial cases including 3 cases of Sipple's syndrome and 4 cases of sporadic cases. There were also 2 cases of Cushing's syndrome. In addition to the previously described English literatures about human medullary carcinoma of the thyroid, the rod-shaped body with cristae and an abundant glycogen particles in the cytoplasm, nuclear inclusion bodies of cytoplasmic invagination and microvilli at the surface membrane of gland formation were found in our cases. The mean and mode diameters of secretory granules of all familial cases with only calcitonin secretion were larger than those of the sporadic cases with ectopic ACTH and beta-MSH in addition to calcitonin secretion. Ultrastructural study on non-cancerous follicles of grossly normal thyroid of two cases of early familial medullary carcinoma disclosed apparently increased C-cells which were not intrathyroidal metastases. It is supposed that the increased C-cells in the thyroid of the familial cases are multicentric C-cell hyperplasia.

Adrenocorticotropic Hormone↗
PubMed1977

Epidemiological studies on patients with a persistent vegetative state.

Persistent vegetative state after severe brain damage was studied epidemiologically in 110 cases from 1973 to 1976. The causes of brain damage were varied. More than one-third of the cases were due to trauma, and about one-fifth were the result of vascular accidents. Three year observation revealed that 65% of the patients died during this period. Mean survival time for dead patients was 38 months. Reactivity, clinical signs, EEG findings, methods of management, and results of various trials of treatment were investigated in connection with the patient's prognosis.

Adolescent↗
PubMed1976

Simple and stable techniques for recording slow-wave sleep.

1. A combination technique of a telemetric system and a Walter-type analyzer have been used in the rat to allow on-line display of the sleep-waking cycle of a freely-moving animal on three consecutive days. 2. The characteristics of slow-wave sleep can be analyzed completely by this technique. 3. Telemetric recording of the integrated slow wave is a good method that allows faster and accurate scoring of slow waves to measure the length of sleep in freely-moving animals.

Animals↗