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Biomedical subjects

K Hara

Publications and source records attributed to K Hara.

At least 1,045 records · Page 58Linked to original sources
PubMed1984

Production of serotonin by a transplantable strain of histamine-producing primary gastric carcinoid of Mastomys natalensis.

Two biochemically distinguishable transplantable tumor strains (A and B) were established from a primary gastric carcinoid of Mastomys secreting histamine alone. Strain A in the third generation acquired a new ability to produce serotonin [5-hydroxytryptamine (5-HT)] and retained endocrine activities to produce both histamine and 5-HT through the following subpassages, whereas strain B (like the primary tumor) continued to produce histamine alone. The findings were further supported by the immunohistochemical demonstration of 5-HT-containing tumor cells in strain A after generation 3 and the absence of such cells in strain B and also by the ultrastructural demonstration of tumor cells containing pleomorphic secretory granules in strain A after the third generation but not in strain B. Sixteen samples of Formalin-fixed, paraffin-embedded primary gastric carcinoids of Mastomys were stained by the same immunohistochemical method for 5-HT detection. The positively stained tumor cells were demonstrated in 4 tumor samples, though they were scantily distributed in tumor parenchyma except for 1 metastasizing tumor. 5-HT-producing tumor cells appeared through many proliferative cycles of the deranged histamine-producing cells. The endocrinologic similarity was noted between this transplantable tumor strain and a specific type of gastric carcinoid in humans, and the possible histogenesis of the latter tumor was discussed on the basis of data obtained from the present transplantation experiments.

Animals↗
PubMed1984

[Quantitative studies on maternal perception of fetal movement with two ultrasonic real-time scanners].

In this study, the relationship between actual fetal movement in utero and maternal perception was investigated with the use of two ultrasonic real-time scanners and a cardiotocogram. The movements of body, arms, legs, fetal breathing, uterine contractions and maternal perception of fetal movement were quantitatively analyzed. 37% of all fetal movements were recognized by the mother. Only 15% of isolated movements of fetal extremities were perceived by the mother. 72% of strong body movements with both hands and legs were recognized. No relationship between the duration and times of fetal movement and gestational weeks was found. On the other hand, a close relationship between the maternal perception rate and gestational weeks was found (28-30W, 48%; 34-35W, 53%; 40W, 67%; R = 0.903). As for the parity of the mother, multiparous women were found to be more sensitive than primiparous women (p less than 0.005). (This study was supported by Alexander von Humboldt-Stiftung in F.R.G.).

Adolescent↗
PubMed1984

Development and application of a sensitive enzyme immunoassay for 7-N-(p-hydroxyphenyl)mitomycin C.

An antibody specific for 7-N-(p-hydroxyphenyl)mitomycin C (M-83) was developed and used in a simple and sensitive enzyme immunoassay for detection of this anticancer drug in serum. The imino group of M-83 was covalently coupled to mercaptosuccinyl groups introduced into bovine serum albumin with a cross-linker, N-maleoylaminobutyric acid. The resulting conjugate was then used for the production of a specific antibody to M-83 in rabbits. Enzyme labeling of M-83 was performed using beta-D-galactosidase (EC 3.2.1.23) via m-maleoylbenzoic acid. Antibody production was of sufficiently high titer in rabbits to allow the development of a highly sensitive enzyme immunoassay for the free drug which accurately measures 15 pg of M-83 per assay tube. This assay was monospecific to M-83 and showed almost no cross-reactivity with a variety of other mitomycin analogues (mitomycin A, B, and C; porfiromycin; and acetylmitomycin C). Using this assay, preliminary pharmacokinetic study was undertaken using serial serum samples obtained from a patient who received the drug i.v., revealing a biphasic fashion of the kinetics, with an alpha-serum half-life of 9.7 min and a beta-serum half life of 80 min. An i.v. injection of M-83 into rats and assay of serum concentration revealed a similar biphasic response with an alpha-serum half-life of 8.3 min and a beta-serum half-life of 62 min.

Antibodies↗