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Biomedical subjects

R Nakano

Publications and source records attributed to R Nakano.

At least 199 records · Page 11Linked to original sources
PubMed1986

Effect of oestrogen on prolactin receptors in porcine granulosa cells.

The binding of 125I-labelled PRL to the porcine granulosa cells was examined. Displacement studies demonstrated that 125I-labelled PRL was specifically bound to the granulosa cells. The specific binding of 125I-labelled PRL to the granulosa cells decreased significantly as the follicles matured. The addition of diethylstilboestrol diphosphate enhanced the binding of 125I-labelled PRL to the granulosa cells harvested from small, medium and large follicles. The results of the present study suggest that oestrogen might have an important role in modulating PRL receptors in porcine granulosa cells.

Animals↗
PubMed1986

Luteinizing hormone receptors in human ovarian follicles and corpora lutea during the menstrual cycle.

The binding of 125I-labeled human luteinizing hormone (hLH) to the 2000-g fraction of human ovarian follicles and corpora lutea during the entire menstrual cycle was examined. Specific high affinity, low capacity receptors for hLH were demonstrated in the 2000-g fraction of both follicles and corpora lutea. Specific binding of 125I-labeled hLH to follicular tissue increased from the early follicular phase to the ovulatory phase. Specific binding of 125I-labeled hLH to luteal tissue increased from the early luteal phase to the midluteal phase and decreased towards the late luteal phase. The results of the present study indicate that the increase and decrease in receptors for hLH during the menstrual cycle might play an important role in the regulation of the ovarian cycle.

Binding Sites↗
PubMed1985

Relationship between human oocyte maturation and different follicular sizes.

The relationship between the follicular size in the human ovary and oocytes capable of resuming meiosis in vitro was examined in each phase of the menstrual cycle. Intact healthy oocytes with corona cells obtained from small (3-4 mm diameter), medium (5-8 mm diameter) and large (9-15 mm diameter) antral follicles were cultured at 37 degrees C for 43 h. At the end of the culture period the denuded oocytes were examined morphologically to determine whether the resumption of meiosis had occurred. In the follicular phase, the percentage of oocytes resuming meiosis (polar body extruded: PB) in the large-follicle group was significantly higher than that in the small-follicle group (P less than 0.05). The incidence of oocyte maturation including only nuclear maturity seemed to increase as follicles increase in size. However, in the luteal phase the incidence was fairly constant, irrespective of the follicular size. These results suggest that the capacity of human oocyte maturation is closely correlated with follicular maturation.

Adult↗
PubMed1985

ABO blood group in patients with malignant trophoblastic disease.

ABO blood group was analyzed in 70 patients with hydatidiform mole and 53 patients with malignant trophoblastic disease. 319 healthy pregnant women served as controls. The distribution of ABO blood groups in patients with hydatidiform mole did not deviate significantly from the distribution in the controls. There was a slight excess in group AB and a slight deficiency in group O in patients with hydatidiform mole. However, there was a significant decrease in blood group A and a slight excess in groups O, B and AB in patients with malignant trophoblastic disease compared with the distribution in healthy pregnant women. A higher mortality rate was observed in group B in patients with malignant trophoblastic disease. In conclusion, ABO blood group of patients with malignant trophoblastic disease can be an important prognostic factor in the diagnosis and treatment of the trophoblastic disease, if a large number of cases are compiled by many investigators.

ABO Blood-Group System↗
PubMed1985

Luteinizing hormone receptor binding inhibitor in aqueous extract of human corpus luteum.

Aqueous extracts of human luteal tissue significantly inhibited binding of 125I-labelled human luteinizing hormone (LH) to the 2,000-g subcellular fraction of human corpora lutea. In contrast, aqueous extract of nonluteal tissue of the human ovary did not show a comparable activity to inhibit LH binding. Extracts of human corpus luteum had little or no ability to inhibit LH binding to porcine luteal homogenates. The inhibitory effect of the aqueous extract on LH binding to human luteal homogenate was demonstrated to be dose-related. The inhibitory effect of aqueous extracts of human corpora lutea on LH binding increased from the early to mid and late luteal phase of the menstrual cycle. The results of the present study suggest that there is an LH receptor binding inhibitor (LHRBI) in the 30,000-g aqueous extract of the human corpus luteum and the increase in LHRBI in the luteal tissue as the human corpus luteum ages may explain the means whereby the human corpus luteum regulates its own life span.

Adult↗
PubMed1985

Adult rat heart cell culture. The morphological study of tissue fragments on various environments in culture.

This paper reports a modification of Jacobson's method for culturing adult rat heart cells after mechanical and enzyme treatment. For heart cell dissociation, it is useful to wash tissue fragments 3 times with saline A solution after enzyme treatment, and it is important to change the medium immediately after culturing heart cells in order to prevent myocardial cells from degeneration caused by the enzyme solution and toxins in the cell debris.

Animals↗
PubMed1984

Anaplastic giant cell tumor with mucinous cystadenocarcinoma of the ovary. Origin of the giant cells.

The present case is that of a 27 years old woman who had received right oophorectomy for ovarian cancer nine years previously. The histological diagnosis at that time was mucinous cystadenocarcinoma with anaplastic areas. The patient expired ten years after oophorectomy due to widespread metastases of the tumor. Review of the histological slides revealed ovarian giant cell tumor which was considered to be of epithelial origin differing from those appearing in giant cell tumor of bone.

Adult↗
PubMed1983

Follicle-stimulating hormone and luteinizing hormone receptors on porcine granulosa cells during follicular maturation: an autoradiographic study.

The autoradiogram prepared from porcine ovaries after incubating for 1 hour at 37 degrees C with either 125I-labelled FSH or LH revealed that FSH bound to granulosa cells while LH bound to thecal cells. Although the granulosa cells of small, medium and large follicles were labelled with FSH, the decrease in grains over granulosa cells was observed during follicular maturation. In contrast, the granulosa cells of small and medium follicles showed only slight labelling with LH, while the granulosa cells of large follicles showed heavy labelling. The present study also indicated that granulosa cells collected from small follicles bound much more 125I-labelled FSH per cell than did cells from medium or large follicles, and granulosa cells harvested from large follicles bound much more 125I-labelled LH per cell than did cells from small or medium follicles. The competition studies with unlabelled hormones revealed that porcine granulosa cells had specific receptors for FSH and LH. The results of the present study suggest that a marked change in the binding of FSH and LH to the granulosa cells from the three follicle types might play a role in follicular growth and maturation.

Animals↗
PubMed1983

Feedback mechanism in sulpiride-induced hyperprolactinaemia.

Feedback of oestrogen on gonadotrophin release was studied in five normally cycling normoprolactinaemic women who were rendered moderately hyperprolactinaemic by oral administration of sulpiride (150 mg daily) for 11 consecutive days. Five patients with peptic ulcer, who had been given 150 mg of sulpiride for 3-18 months and had chronic marked hyperprolactinaemia were also studied. Ethinyl oestradiol (200 micrograms) was administered by mouth daily for 4 consecutive days and serum concentration of prolactin, luteinizing hormone (LH), follicle stimulating hormone (FSH) and oestradiol were measured by a double-antibody radioimmunoassay for 11 days. Oral administration of ethinyl oestradiol caused an initial decrease followed by a rebound of LH with a peak in all the women tested. The serum FSH levels showed only the initial decrease, followed by a slight rebound. Serum oestradiol levels decreased during oral administration of ethinyl oestradiol in all the women. The results of the present investigation suggest that oestrogen feedback effect on LH release is maintained in sulpiride-induced hyperprolactinaemic women as well as in women with normal cycles.

Adult↗
PubMed1983

Relationship among the status of the human oocyte, the 17 beta-estradiol concentration in the antral fluid and the follicular size.

We studied the relationship among the status of the human oocytes, the E2 concentration in the antral fluid and the follicular size in the different phases of the menstrual cycle, in order to determine the microenvironment of the follicles with healthy or degenerative oocytes in the human ovary. In the follicular phase of the menstrual cycle, follicles which contained a healthy but not degenerative oocyte had a significantly higher level of 17 beta-estradiol (E2). In the late follicular phase, the larger follicles (greater than or equal to 13 mm, in diameter) had only health oocytes. It seems that the follicle containing a degenerative oocyte does not develop physiologically until maturation of the preovulatory follicle. In the luteal phase, there were no relationships among the status of the oocyte, E2 concentration in the antral fluid and the follicular size. However, the E2 levels of the antral follicles with healthy oocytes in an ovary with corpus luteum were significantly lower than those in the contralateral ovary. The results suggest that the corpus luteum may exert an influence on the adjacent follicles.

Adult↗