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Biomedical subjects

O Midorikawa

Publications and source records attributed to O Midorikawa.

At least 55 records · Page 3Linked to original sources
PubMed1983

[Prolyl hydroxylase activity in rabbit ovary during ovulatory process].

The disruption of connective tissue and dissociation of collagen fibers that occurs in the ovarian follicle during mammalian ovulation is reportedly induced by collagenolytic enzymes. To further analyse the metabolism of ovarian collagen during the ovulatory process, prolyl hydroxylase activity was assayed because the quantity of this enzyme provides some indication of the relative amount of collagen fibrillogenesis in connective tissues. Following the induction of ovulation by hCG, prolyl hydroxylase activity increased in both the ovarian follicle and stroma. The amount of activity reached a maximum of about 300% above the control level at 13hr after hCG, i.e., 1-3hr after the estimated time of ovulation. The pattern of enzyme activity during the ovulatory process was identical in both the follicle and the stroma. The prolyl hydroxylase activity remained at more than 200% above the control level throughout the secretory phase. It is concluded that the rabbit ovarian follicle and stroma contain prolyl hydroxylase activity, and that this enzyme activity increases significantly during the ovulatory process and luteinization.

Animals↗
PubMed1982

Bronchial plasmacytoma identified by immunoperoxidase technique on paraffin embedded section.

A case of bronchial plasmacytoma occurring in a 57-year-old housewife is reported. She had had the productive cough and the "abnormal shadow" in the right lower lobe for three years before admission. On bronchoscopy, a tumor was found in the right main bronchus, large enough to obstruct the air way. The tumor was resected through rigid bronchoscope. Histological impression was "plasmacytoma with local amyloid deposit." M-protein was never detected in the serum or urine. Applying the immunoperoxidase technique for the paraffin section, the plasma cells were found to contain only a single type of immunoglobulin, Ig G-L. The differential diagnosis between plasmacytoma and plasma cell granuloma was made, and plasmacytoma was considered to be one type of extranodal malignant lymphoma.

Antibodies, Monoclonal↗
PubMed1981

Collagenolytic enzyme activity in human ovary: an ovulatory enzyme system.

Collagenolytic enzyme activities presumed to play an important role in ovulation were investigated in the human follicular apex, base, and granulosa cell layer throughout the ovarian cycle. Those analyzed were human ovarian collagenase, 2,4-dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg-OH peptidase, N-carbobenzoxy-Gly-Pro-Gly-Gly-Pro-Ala peptidase, and alpha-N-benzoyl-DL-arginine beta-naphthylamide hydrolase. Collagenase activity was also measured in human granulosa cell cultures. The activities of all four enzymes showed a marked preovulatory decrease in the apex. The activities in the apex were slightly higher than those in the base throughout the ovarian cycle. However, the activities in the granulosa cell layer and collagenase activity in the granulosa cell cultures increased toward preovulation and decreased after ovulation. These findings suggest that collagenase is synthesized in the granulosa cells maximally at preovulation and is consumed in the follicular apex at the same time, resulting in collagen degradation and disruption of the follicular wall in collaboration with other collagenolytic enzymes investigated here.

Aminopeptidases↗
PubMed1981

Aicardi's syndrome - report of an autopsy case.

A Japanese girl aged 19 months had generalized convulsions, agenesis of the corpus callosum, peculiar chorioretinopathy, scoliosis and marked retardation of psychomotor development. Pathological investigation revealed polymicrogyria, cortical heterotopias, disorganization of the cerebellar cortex. In ocular histopathology, lacunae were composed of hypo- or depigmented zones of the retinal pigment epithelium accompanied with dispersion of pigments into the rod and cone layer. Coloboma of the optic nerve was also evident. There was no evidence of inflammation or pathogenic organisms.

Agenesis of Corpus Callosum↗
PubMed1981

Effect of hormonal milieu on the growth of transplantable granulosa cell tumors in mice.

Two transplantable granulosa cell tumor lines (designated as T and M lines) induced in mice by intrasplenic ovarian grafting were established. The hormonal milieu which promotes the growth of transplantable granulosa cell tumors was investigated in the present work. The inoculation of the T line tumors into host animals led to tumor formation in intact and gonadectomized animals, but not in hypophysectomized animals.Subcutaneous grafts in intact male hosts were significantly large than those in gonadectomized male hosts, whereas tumors of approximately equal size were formed in androgen-treated gonadectomized male hosts. These results indicate that both androgens and gonadotropins promote the tumor growth in vivo. The behavior of the M line tumors was similar to that of the T line tumors. When the cell growth of the M line tumors was examined in culture, steroid hormone depletion in medium did not affect the growth of the tumor cells, nor did androgen have a growth-promoting effect in serum-free medium or in medium supplemented with charcoal-extracted male mouse serum. It was concluded that the growth-promoting effect of androgens is not direct, and that androgens themselves or their derivative estrogens may produce specific growth factors, which in turn promote the tumor growth in vivo.

Animals↗
PubMed1979

Chromosomal banding patterns produced by methyl green-pyronin staining after trypsin treatment.

A method is described for producing banding patterns with methyl green-pyronin (MGP) stain in chromosomes of fibrosarcoma cells. 1) The stain was made by mixing equal volumes of 2% aqueous pyronin G, 2% aqueous methyl green, distilled water, and 0.1 M acetate buffer (pH 5.7). 2) Treatment with colcemide and hypotonic KCl (0.075 M) was performed as usual. 3) Metaphase chromosomes were prepared using the flame-drying technique and treated with 0.25% trypsin at 37 C for 45 to 90 seconds. Before staining, the slides were rinsed in PBS, in distilled water, and then were dipped in 0.05 M acetate buffer. 4) Chromosomes were stained for more than 20 minutes, rinsed in distilled water, and hot-air dried. Satisfactory results were obtained in uncontracted metaphase chromosomes. MGP stain has the advantage of permitting much longer trypsin treatment and staining time than the trypsin-Giemsa method while providing satisfactory banding patterns.

Animals↗
PubMed1977

Increased lysyl oxidase activity in blood vessels of hypertensive rats and effect of beta-aminopropionitrile on arteriosclerosis.

The activity of lysyl oxidase which catalyzes the initial step of cross-linking of collagen and elastin polypeptides was measured in blood vessels of the hypertensive rat. The enzyme activity was increased in the aorta and mesenteric artery when hypertension was induced in 8-week-old rats with administration of deoxycorticosterone acetate (DOCA) and 1% saline. Reserpine diminished this increase in vascular lysyl oxidase activity concomitant with reduction in blood pressure. When beta-aminopropionitrile, a specific inhibitor of lysyl oxidase, was administered before the onset of DOCA-salt hypertension, the aortic collagen content was reduced markedly. Concomitant with reduction in the aortic collagen content, the development of hypertension and arteriosclerotic changes in the kidney was partially prevented. These results would indicate that hypertension increases the amount and the degree of cross-linking of vascular collagen and that the deposition of excess collagen in the vascular wall contributes to the development of hypertension and arteriosclerosis.

Amino Acid Oxidoreductases↗
PubMed1977

Transmission and scanning electron microscopy of host cell entry by Toxoplasma gondii.

Entry by tachyzoites of Toxoplasma gondii, the causative agent of toxoplasmosis, into peritoneal cells was investigated with transmission and scanning electron microscopy. The process of entry is initiated by the parasite contacting the host cell with its anterior end, creating a small depression in the plasmalemma of the host cell. Occasionally, a small portion of the host cell cytoplasm protrudes and contaccts the anterior end of the parasite. A cylindrical structure (35 nm in diameter) extends from the pellicle of the parasite to the host cell. Such structures appear to assist host cell entry by T. gondii. As the entry process progresses, pseudopods of the host cell surround theparasite and finally T gondii becomes intracellular, being located in a vacuole separated from the host cell cytoplasm by a unit membrane. (Am J. Pathol 87:285-296, 1977).

Animals↗