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Biomedical subjects

Y Sagara

Publications and source records attributed to Y Sagara.

At least 199 records · Page 11Linked to original sources
PubMed1989

[The climacteric: aging of ovary and objective evaluation of the climacteric symptoms].

Since the geriatric population has been increasing in the recent years, the health care of the elderly, especially the climacteric group, has received special attention in the gynecological field. The primary endocrine feature during the climacteric is the decline in estradiol (E2) production due to the loss of ovarian function. Pathophysiological characteristics of aging ovaries remain obscure. To understand the mechanism of the aging process in the ovaries, the lipid peroxidative status which has been suggested as a deteriorator involved in aging, and antioxidative defense system were investigated during aging. The amount of lipid peroxide (LPO) as a free radical decreased steadily in human ovaries with aging. In contrast, antioxidative enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) showed a rapidly decreasing rate in these enzyme activities after 45 and 50 years of age, respectively. The in vitro production of E2 following the incubation with FSH was also measured in human ovaries with aging. The results indicate an excellent positive correlation between E2 production and the level of GSH-Px and reduced glutathione, but a negative correlation between E2 production and the amount of LPO. Our data suggest that the relatively high level of LPO to SOD and/or GSH-Px following 45 years of age may play an important role in the aging process of human ovaries. From the clinical aspect of the climacteric, scientific evaluation of the climacteric symptoms and responses to various therapies has not been sufficiently addressed because of the lack of a practical technique for objectively measuring the symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Molecular cloning of a cDNA for rat liver monoamine oxidase B.

The cDNA for rat monoamine oxidase B mRNA was isolated from liver cDNA library in lambda gt11 using specific antibody and oligonucleotide probes derived from FAD-containing peptide of the enzyme. The primary structure of the protein, deduced from the nucleotide sequence, consisted of 520 amino acid residues and its molecular weight was calculated to be 58.4 kD which is in good agreement with that of the in vitro-synthesized peptide. FAD-binding site is located in the carboxy-terminal region. There is no typical structural feature common to the targeting signals for mitochondria, the periodic distribution of basic amino acids spaced by several uncharged residues, at its amino-terminal region. This region has an uninterrupted stretch of 14 hydrophobic residues.

Amino Acid Sequence↗
PubMed1988

Generalized lymph node metastasis of early uterine cancer in an HTLV-I carrier.

Generalized lymphadenopathy due to metastases of keratinizing squamous cell carcinoma developed in a 68-year-old woman who was a carrier of human T-cell leukemia Type I (HTLV-I). On her 74th hospital day, she died of massive metastases of the superficial and deep-seated lymph nodes, thyroid, lungs, pleura, liver, spleen, pancreas, kidneys, and retroperitoneum. At autopsy, the primary tumor was found in the uterine cervix. The depth of stromal invasion was approximately 4.0 mm. Such an extensive dissemination usually does not occur in cervical cancer with this type of early stromal invasion. It is conceivable that the chronic HTLV-I infection compromised the immunosurveillance against cancer and accelerated progression of the disease in this patient.

Carrier State↗
PubMed1988

Effect of vagus nerve cooling on hypercapnic and hypoxic ventilatory responses in anesthetized dogs.

We studied ventilatory responses under hypercapnic and hypoxic conditions in 18 lightly anesthetized dogs, using a vagus nerve cooling technique. One side of the cervical vagosympathetic trunks of dogs were previously severed, and a copper cooling probe was attached to the other side. When the cervical nerve was cooled below 7 degrees C, Hering-Breuer inflation reflex ceased. We found that when the vagus nerve was not cooled or cooled up to 7 degrees C, the respiratory frequency increased significantly in relation to hypercapnic gas inhalation. However, the increment of respiratory frequency was reduced by bilateral cervical vagotomy. On the other hand, the respiratory frequency in response to hypoxia increased significantly, even when bilateral vagotomy was done. The increment of the tidal volume in response to hypercapnic gas inhalation was reduced by the Hering-Breuer inflation reflex. We found that the effect of the vagus nerve on respiratory regulation was different between hypercapnic and hypoxic gas inhalation.

Animals↗
PubMed1988

[Lipoleiomyoma of the uterus--report of a case].

A case of lipoleiomyoma, measuring 4 x 4.5 x 5 cm, in the uterine corpus is reported in a 64-year-old multiparous woman. Histologically, the tumor was mostly composed of mature fatty tissue intermingled with small amount of fibrous and smooth muscle components in an irregularly reticular or clustered pattern. Immunohistochemically fibroblast-like cells around the perivascular areas of the fibrous components were positive in various numbers for S-100 protein, desmin, vimentin, neuron specific enolase, alpha 1-antichymotrypsin and Factor VIII. These results indicated the possibility that the present lipoleiomyoma was derived from multipotential undifferentiated mesenchymal cells, resembling fibroblast-like cells.

Female↗
PubMed1987

Synthetic partial extension peptides of P-450(SCC) and adrenodoxin precursors: effects on the import of mitochondrial enzyme precursors.

Various portions of the extension peptides of P-450(SCC) precursor were chemically synthesized. The effects of these peptides on the import of enzyme precursors into mitochondria were examined. Peptides SEP1-15 and SEP1-20, corresponding to the amino terminal portion of the extension peptides, strongly inhibited the import of P-450(SCC) precursor into mitochondria. These peptides were effective at concentrations above 30 microM, and complete inhibition was observed at 100 microM. SEP1-11, which is shorter than SEP1-15 and SEP1-20, showed very weak inhibition. SEP25-39, which corresponds to the carboxy terminal portion of the extension peptide, did not affect the import of the precursor. The import of P-450(11 beta) and adrenodoxin precursors were also inhibited by SEP1-15. Another peptide, AEP1-14, which corresponds to the amino terminal portion of the extension peptide of adrenodoxin precursor, was also synthesized. The peptide inhibited the import of both adrenodoxin and P-450(SCC) precursors into mitochondria. The import of malate dehydrogenase was also inhibited by SEP1-15 and AEP1-14. The rate of the internalization of the precursor into mitochondria was decreased by the peptides. The amount of the precursor bound to the surface of mitochondria and the processing of adrenodoxin precursor were not affected. The respiratory activities of isolated mitochondria were not influenced by SEP1-15 even at 100 microM. We conclude that the inhibitory activities of the synthetic partial extension peptides on the import of enzyme precursors into mitochondria require the presence of about fifteen amino acid residues in the amino terminal portion of the extension peptides, and the inhibition of the import by the peptides was dependent on the blockage of the internalization of the precursors into mitochondria.

Adrenodoxin↗
PubMed1987

Cloning and sequence analysis of adrenodoxin reductase cDNA from bovine adrenal cortex.

cDNA clones for bovine adrenodoxin reductase were isolated, and the primary structure of the enzyme precursor was deduced from their nucleotide sequences. The precursor consists of 492 amino acids including an extrapeptide of 32 amino acids at the amino terminus. The extrapeptide is hydrophilic [corrected] and rich in arginine. The amino terminal sequence of the precursor is homologous with that of the adrenodoxin precursor. A possible FAD- or NADPH-binding site is present near the amino terminus of the mature enzyme.

Adrenal Cortex↗
PubMed1987

[Mechanism of the suppressive effect of catechol estrogen on the preovulatory LH surge].

The administration of 100 micrograms 2-hydroxyestrone (2-OHE1) or 2-hydroxyestradiol-17 beta (2-OHE2) at 0900h or 1000h in the morning of proestrus into normal 4-day cycling rats results in suppression of the preovulatory LH surge in the afternoon of that day. The LH-RH content of the median eminence in control rats decreases sharply in the afternoon from elevated noon levels. However, the catechol estrogen-treated rats do not show this decrease. These results indicate that the catecholestrogens block the preovulatory LH surge by preventing the release of LH-RH from the median eminence, but do not interfere with the synthesis and accumulation of LH-RH. Furthermore, injections of non-uterotropic 2-OHE1 twice at 30 minutes intervals into ovariectomized rats fail to affect the LH tonic secretion by 180 minutes after the initial injection. These data indicate that catechol estrogen interferes with the brief neuronal triggering phase necessary for LH-RH release, but does not affect the LH tonic secretion which is an estrogen-independent process.

Animals↗
PubMed1986

Studies of catecholestrogen metabolism during normal pregnancy: changes of plasma catecholestrogen levels after DHA-S or E1-S injection.

So as to evaluate metabolism of catecholestrogens during pregnancy, changes in plasma unconjugated estradiol (E2), estrone (E1), 2-methoxyestradiol (2-mE2) and 2-methoxyestrone (2-mE1) concentrations were measured after a bolus injection of 40mg of estrone-sulfate (E1-S) or 100mg of dehydroepiandrosterone-sulfate (DHA-S) to normal pregnant women near term. The injection of E1-S resulted in a marked rise in plasma 2-mE1 levels followed by a rapid marked increase in the plasma E1 concentration. The injection of DHA-S produced a small increase in the plasma 2-mE2 levels in spite of a marked increase in the plasma E2 concentration. No significant correlation between E2 and 2-mE2 was found, however, significant correlations between E1 and 2-mE1, between E1 and 2-mE2 and between 2-mE2 in in both groups were demonstrated. The marked increase in 2-mE1 compared to a small increase in 2-mE2 after DHA-S injection indicates that E2 may participate in the formation of catecholestrogen via its conversion to E1 during pregnancy. These results suggest that the main route for the formation of catecholestrogen is via E2----E1----(2OHE1)----2-mE1 in normal pregnancy near term.

Biotransformation↗