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Biomedical subjects

Y Kitamura

Publications and source records attributed to Y Kitamura.

At least 847 records · Page 47Linked to original sources
PubMed1976

Progesterone metabolism in vitro by testes from germ cell-free mice of different ages.

Androgen biosynthesis in vitro by testes from (C57BL X WN)F1-WV/Wn (congenitally germ cell-free) and +/+ (normal) mice of different ages was investigated using [3H]progesterone as substrate. At all ages examined, the seminiferous tubules of the WV/Wn genotype were largely devoid of germ cells. However, the age dependent pattern of progesterone metabolism by germ cell-free testes were similar to that by normal testes. Conversion of progesterone to 5alpha-reduced 17-hydroxy-C21 and C19-steroids such as 3alpha,17alpha-dihydroxy-5alpha-pregnan-20-one, androsterone, 5alpha-androstane-3alpha,17beta-diol and 5alpha-androstane-3beta,17beta-diol was high in testes of 28- and 35-day-old mice of both groups. However, these 5alpha-reduced metabolities were found to be formed in very small amounts or not formed at all in testes of 20-, 120- and 150-day-old mice of both groups, in which conversion of progesterone to 17alpha-hydroxyprogesterone, androstenedione and testosterone was observed. It appears that in the absence of germinal cells, there is a normal increase and reduction of 5alpha-reductase activity in one or more classes of remaining cells during maturation of the testis.

Aging↗
PubMed1976

Effect of angiotensin II on noradrenaline content in the rat hypothalamus.

1. Intravenous administration of angiotensin II reduced the adrenaline content, increased the catechol-O-methyltransferase activity, and decreased the monoamine oxidase activity of rat hypothalamus. 2. Intraventricularly administrated angiotensin II reduced the noradreanline content to a smaller extent. 3. The change produced by intravenous administration of angiotensin might be indirectly caused by a response to angiotensin.

Angiotensin II↗
PubMed1976

Effects of BCG (Bacillus Calmette-Guérin) vaccines on immune responses in mice. I. Possible effect of BCG on helper T cells.

The effects of killed and living BCG on antibody production against hamster erythrocytes (HRBC) and the 2, 4, 6-trinitrophenyl (TNP) group were studied in SL mice. Killed and living BCG, each in doses of 0.008 mg, 0.08 mg, 0.8 mg and 8 mg per mouse, were intravenously inoculated 7 days prior to primary immunization with HRBC. Secondary immunization was carried out 28 days later with TNP-HRBC. Anti-HRBC and anti-TNP antibodies were estimated by a hemagglutination test. The results showed that pretreatment with killed or living BCG enhanced the antibody production against both HRBC and TNP. Comparing the effects of these two BCG preparations, it was noted that killed BCG augmented the anti-HRBC antibody production more effectively than living BCG. In regard to the anti-TNP antibody production, living BCG exhibited a greater augmenting effect than killed BCG. This difference in the modes of action of killed and living BCG was remarkable when two groups given 8 mg of killed and living BCG were compared. In addition, it was shown that living BCG at a dose as high as 8 mg was able to augment the anti-TNP antibody production, even in the absence of preceding immunization with HRBC.

Animals↗
PubMed1976

The response of the renal vasculature to prostaglandin E in man.

Fifty micrograms of prostaglandin E1 (PGE1) dissolved in 10 ml of physiologic saline solution were injected into the renal artery of 33 hematuria patients. The serial films obtained before and after the injection of PGE1 were compared. The administration of PGE1 promoted the entry of the contrast medium into the renal artery as early as 0.5 sec after its injection. There were cases in which the time of the appearance of maximum arterial phase was shortned, even observed at the 0.5-sec interval. The maximum nephrogram appeared earlier after the administration of PGE1, and enlargement of the major axis of the nephrogram was observed. The time of appearance of the maximum venous phase was also shortened by the administration of PGE1. Thus, the increase of the renal blood flow with PGE1 was suggested roentgenologically. The mechanism of action and the clinical applicability of prostaglandin are discussed.

Adolescent↗
PubMed1975

Colony-forming ability of bone marrow cells of W anaemic mice on macrophage layer formed in peritoneal cavity of mice.

The colony-forming ability of haematopoietic cells of W anaemic mice was examined on the macrophage layer formed in the peritoneal cavity of mice. Bone marrow cells of W anaemic mice formed a considerable number of colonies on the macrophage layer, notwithstanding they did not form any colonies in the spleen of the same recipients. As the colony-forming ability of the bone marrow cells was not reduced by the incubation with 3-H-thymidine, most of the cells which formed colonies on the macrophage layer seemed to stay in G0 state. The interrelationship between the spleen colony-forming cells, the macrophage-layer colony-forming cells, and in vitro colony-forming cells was discussed.

Anemia, Macrocytic↗
PubMed1975

[A trial for electromyography of the detrusor muscle (author's transl)].

The author developed a new electromyography of the detrusor muscle which is applicable also for clinical examinations and obtained the following results: 1. In the normal bladder no action potential appeared when the organ was not full yet. 2. When the intravesical pressure was raised by introducing saline into the bladder, spikes appeared. 3. Spikes of high frequency appeared with the onset of voiding. 4. In the normal bladder no action potential appeared by administration of 5 to 7 mg mecholyl. 5. From some muscles of the dome of the bladder was obtained spontaneous spike potential consisting of spike burst of about 10 spikes. In an animal experiment using adult dogs the spikes of the simple type appeared. The discharged interval was about 5 seconds. 6. In the bladder with damaged nerve, spikes appeared during veridical quiescence. 7. In the bladder with damaged peripheral nerve, spikes of high frequency appeared by administration of 5 to 7 mg mecholyl.

Animals↗
PubMed1975

Factors which influence development of macrophage-layer and spleen colonies in mice.

Irradiated mice infused with bone marrow cells developed colonies both in the spleen and on the macrophage layer of the cellulose acetate membrane which had been inserted into their peritoneal cavity. Factors influencing the ratio of spleen to macrophage-layer colonies were examined. The ratio of the colonies depended on the condition of the recipients rather than the condition of the injected cells provided there was no marked histoincompatibility between donors and recipients.

Animals↗
PubMed1975

Range of xenogeneic donors whose hematopoietic cells can form colonies on macrophage layer of mice.

The colony-forming ability of hematopoietic cells derived from 18 species of rodents was examined on the mouse macrophage layer which formed on a cellulose acetate membrane inserted into the peritoneal cavity of mice. Bone marrow cells of 12 xenogeneic species made a considerable number of colonies on the mouse macrophage layer. However, there was no parallelism between the colony-forming ability of the cells and donor's taxonomic relationship to the mouse.

Animals↗