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Biomedical subjects

I Nagata

Publications and source records attributed to I Nagata.

At least 145 records · Page 8Linked to original sources

An ovarian tumor of probable Wolffian origin with hormonal function.

In 1973, the histopathologic features of nine neoplasms with a distinctive appearance were reported under the term "female adnexal tumor of probable Wolffian origin." Although to date more than 40 cases of this disease have been reported in the literature, there have been only a few reports that the tumors might be endocrinologically active. We report on a hormonally active tumor of this type.

Estradiol↗

Complete inhibition of human ovarian cancer xenografts in nude mice by suramin and cis-diamminedichloroplatinum(II).

In this study, we have determined the adjuvant effects of suramin to cis-diamminedichloroplatinum(II) (CDDP) on human ovarian cancer (KF) cell growth in vitro and in vivo. Suramin inhibited the ovarian cancer cell proliferation in vitro in a dose-dependent manner between 10 and 80 microM, showing the IC50 of 29 microM. From analysis of flow cytometry (FCM), suramin seemed to be a blocker of G2-M phase of the cell cycle. From the results of the isobologram, suramin appeared to have additive and somewhat synergistic effects on antitumor activity of CDDP. When 5 x 10(5) KF cells were inoculated sc into the right flank of nude mice, 8 of 10 mice formed solid tumor at 4 weeks. When 2 mg/kg CDDP was administered ip every week, the 80% tumor formation was prolonged to 10 weeks. Treatment with 5 and 10 mg/kg suramin decreased the formation rate of palpable tumor to 50 and 30%, respectively. When CDDP was followed by 5 or 10 mg/kg suramin, the tumor formation rate was 20 or 0%. On the other hand, if suramin was followed by CDDP, the tumor formation was not observed in any mouse during the experimental period. These results suggest that suramin may provide a new strategy for treatment of refractory ovarian carcinoma.

Animals↗

Effects of a dopamine antagonist (metoclopramide) on the release of beta-endorphin, ACTH and cortisol in hyperprolactinemic-amenorrheic women.

Responses of LH, TSH, PRL, beta-endorphin-like immunoreactivity, ACTH and cortisol to metoclopramide were evaluated in hyperprolactinemic-amenorrheic women and normal women. Augmented TSH responses and blunted PRL responses to metoclopramide were found in hyperprolactinemic women compared to normal women. A significant increase in serum LH levels was found only in hyperprolactinemic women after metoclopramide. Thus, the hyperprolactinemic women showed hormonal changes compatible with increased central dopaminergic tone. A significant increase in circulating levels of beta-endorphin-like immunoreactivity, ACTH and cortisol was found in hyperprolactinemic women but not in normal women after metoclopramide administration. Thus, beta-endorphin and ACTH secretion appear to be tonically inhibited by increased central dopaminergic tone in hyperprolactinemic-amenorrheic women.

Adrenocorticotropic Hormone↗

Measurement of urinary free beta-human chorionic gonadotropin by immunoradiometric assay.

An immunoradiometric assay for free beta-human chorionic gonadotropin (F beta hCG) is now available. Measurement of serum F beta hCG has been shown to be valuable for the diagnosis of trophoblastic disease and for screening Down's syndrome pregnancies. Urine specimens may be preferable to blood samples since collection of urine specimens usually are less inconvenient to patients than venipuncture. We have evaluated whether the immunoradiometric assay can be applicable to urine samples. The assay was sensitive and precise. When urine samples were diluted 4-fold or more, the diluted samples gave quantitative values, and recovery of beta hCG added to urine samples was satisfactory. Creatinine corrected urinary F beta hCG levels correlated with serum F beta hCG levels. Thus, the immunoradiometric assay was considered to be applicable to urine samples. Serum F beta hCG to hCG ratio has been reported to be important to distinguish among normal pregnancies, hydatidiform mole and choriocarcinoma. However, urinary F beta hCG to hCG ratio did not significantly correlate with serum F beta hCG to hCG ratio. And therefore, the clinical value of urinary F beta hCG to hCG ratio should be further investigated.

Chorionic Gonadotropin↗

Dysgerminoma of the ovary with hypercalcemia associated with elevated parathyroid hormone-related protein.

The purpose of the present paper is to present a rare case of dysgerminoma of the ovary with hypercalcemia showing elevation of multiple serum tumor markers including parathyroid hormone-related protein (PTH-rP). An 18-year-old unmarried woman, with ovarian dysgerminoma showing hypercalcemia and elevated serum PTH-rP, received six courses of a combination chemotherapy consisting of bleomycin, etoposide and cisplatin after her first surgery, and had no evidence of recurrence approximately 30 months after completing the chemotherapy.

Adolescent↗

[A case of arteriovenous malformation successfully treated with functional mapping of the language area by PET activation study].

The authors report a case of temporal AVM safely treated by mapping the language area with PET activation study. The patient was a 50-year-old woman with temporal epilepsy as her chief complaint. MRI and angiography revealed a right temporal AVM. Before surgical treatment, we assessed the dominant hemisphere with PET activation study. We performed PET scanning while the patient was playing "capping" (called "Shiritori" in Japanese), from which we subtracted PET images performed when she was in a resting state, and then we superimposed those images upon MRIs. The blood flow increased in the left frontal operculum (Broca's area), the left caudal head, the left putamen and the right cerebellar hemisphere. We were thus able to determine that her left hemisphere was dominant, and that it was safe to undertake embolization and operation for the AVM. Postoperative course was uneventful and higher cortical functions were preserved perfectly. In cases of cerebral AVMs, unusual dominancy of cerebral hemispheres is often encountered, and so, preoperative evaluation of the relation of AVM to the eloquent cortex is essential. In our study, blood flow increased in some areas other than the language area, but they were considered to be areas related to phonation, and we think that we were able to map the language area. Though this method is still in its preliminary stage, we think it gives us useful information for surgical treatment of cerebral AVMs.

Brain↗

Monocular elevation paresis caused by an oculomotor fascicular impairment.

A 54-year-old man developed an acquired monocular elevation paresis. Forced lid closure or oculocephalic reflexes failed to elevate the affected eye in contrast to the contralateral eye, which turned fully upward using either maneuver. A mass lesion compressing the lateral aspect of the right oculomotor nerve at the exit of the brainstem was found. The monocular elevation paresis in this patient reflects damage of the oculomotor nerve fascicles that supply the inferior oblique and superior rectus muscles. This case supports the accepted topographical fascicular arrangement of the oculomotor nerve, with the inferior oblique and superior rectus being the most lateral and caudal, and the pupilloconstrictor fibers and the inferior rectus being most medial and rostral.

Brain↗

[Circumvention of cisplatin resistant ovarian cancer cells by antiestrogens].

Antiestrogens (AEs) have been considered to elicit antitumor effects via estrogen receptor. However, recent reports have demonstrated that AEs had an antitumor effect even in cases without estrogen receptor, and that AEs caused various kinds of biological behavior such as a chemosensitizing effect. We therefore investigated the possibility of circumvention of cisplatin (CDDP) resistance due to the chemosensitizing effect of AEs by using 5 ovarian cancer cell lines. They were named KF, MH, KK, KFra and KFrb cell lines. KF and MH were derived from serous cystadenocarcinomas, and KK from a clear cell carcinoma. KFra and KFrb were CDDP-resistant cell lines developed from the KF cell line. MCF-7 cell line derived from breast cancer was used as a control. The study of a 50% inhibitory concentration (IC50) revealed that clomiphene (CLO) had the most potent antiproliferative effect among the AEs used, and was followed by tamoxifen (TAM) and toremifene (TOR) with a similar effect. On the whole, the degree of CDDP sensitivity was not correlated with the degree of AE sensitivity. KFra cell line which had the highest CDDP-resistance among the 5 ovarian cancer cell lines used was the most sensitive to AEs, especially to CLO. In the study on the combined administration of CDDP and AEs, 1 microM of CLO significantly reduced the IC50 of CDDP to KFrb, KK and MCF-7 cell lines. Similarly, 1 microM of TAM significantly reduced the IC50 of CDDP to KF, KFra and MCF-7 cell lines, and 1 microM of TOR significantly reduced it to KFra, KK and MCF-7 cell lines.(ABSTRACT TRUNCATED AT 250 WORDS)

Cisplatin↗

[MRI of the pituitary adenomas with reference to the hormonal activity].

Many studies in Magnetic Resonance Imaging (MRI) of pituitary adenomas are already performed. However, few reports exist about MRI findings of pituitary adenomas with reference to the hormonal activity, therefore, we evaluated this problem on the viewpoint of the signal intensity in MRI and pathological features. Fifteen patients with growth hormone producing adenoma (GH-group), 6 patients with prolactin producing adenoma (PRL-group), 15 patients with endocrinologically non-functioning adenoma (Null-group) and 9 cases with normal pituitary gland (normal control group) were examined. Signal intensity values in adenoma (or anterior lobe in normal control group) and in pons as standard value were measured in each cases, then their rates were calculated as signal intensity ratio (SIR). In 24 cases (14 in GH-group, 3 in PRL-group, 7 in Null-group), cellular density were examined with surgically resected specimens. In the T1-weighted images (T1 WIs), PRL-group and Null-group presented more hypointense tendency than normal control group. In the T2-weighted images (T2 WIs), only Null-group presented more hyperintense tendency than other groups. But significant correlation was not observed between SIR and cellular density.

Adenoma↗

A novel biological aspect of ovarian oxytocin: gene expression of oxytocin and oxytocin receptor in cumulus/luteal cells and the effect of oxytocin on embryogenesis in fertilized oocytes.

Recently, several authors have reported the existence of oxytocin (OT) in mammalian granulosa-luteal cells after ovulation. The purpose of this study was to examine the evidence for gene expression and localization of OT and OT receptor (OTR) in the cumulus cells surrounding the oocytes. Cumulus cells with mature oocytes were obtained from experimental and clinical in vitro fertilization-embryo transfer (IVF-ET) programs. OT and OTR gene expression was analyzed with reverse transcriptase-polymerase chain reaction (RT-PCR) and RT-PCR/single strand conformation polymorphism (SSCP). OT gene expression was detected in mouse and human cumulus cells. The results of RT-PCR/SSCP showed that the structure of OT mRNA in cumulus cells was similar to that in the hypothalamus. Furthermore, OTR gene expression was clearly demonstrated in human cumulus cells, and a weak positive signal was observed in human oocytes. Immunocytochemical staining of OTR was clearly detected in human cumulus cells. The rate of mouse blastocyst development was significantly higher in the group cultured with OT than that without OT. These results are the first observations of simultaneous OT and OTR gene expression in cumulus cells, suggesting that ovarian OT might have some physiological role in the early stage of embryo development.

Animals↗