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Biomedical subjects

I Nagata

Publications and source records attributed to I Nagata.

At least 19 recordsLinked 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

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

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

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

Recently, several reports have demonstrated the presence of oxytocin (OT) in the corpus luteum of mammalian species. However, the biological role of ovarian OT remains obscure. This study was performed to examine OT gene expression in cumulus cells of mice and humans, and in human corpus luteum, and the role of OT in early embryogenesis. OT gene and OT mRNA were analyzed by reverse transcription-polymerase chain reaction, with single-strand-conformation polymorphism and heteroduplex procedures. OT-treated in-vitro-fertilized mouse oocytes were cultured and the rate of blastocyst development estimated. An immunohistochemical study was also carried out to detect OT on the surface of the mouse oocytes.

Animals

[The effect of nicardipine on angiogenesis in vitro].

We studied the effect of nicardipine, a calcium channel blocker, on the morphological change of endothelial cells in vitro. Cultured endothelial cells derived from bovine carotid artery make tubular structures between collagen gel layers. Tube formation of endothelial cells was suppressed by culture with 10(-9)-10(-5) M of nicardipine in a dose dependent manner. Migration of endothelial cells was also suppressed by the same dose of nicardipine. However, proliferation of endothelial cells was not enhanced. These findings suggest that nicardipine acts as an inhibitor of angiogenesis in vitro by inhibiting the migration of endothelial cells.

Animals

Adjuvant effects of antineoplastic prostaglandins to cisplatin in nude mice bearing human ovarian cancer cells.

Effects of antineoplastic prostaglandins (PG) on human ovarian cancer cell growth were examined by using HR cells derived from ascites of a patient with serous cystadenocarcinoma of the ovary. With regard to inhibition of cancer cell proliferation in vitro, the effects of delta 7-PGA1 was most marked, followed by that of delta 12-PGJ2, PGJ2 and PGD2. When antineoplastic prostaglandins were administered to nude mice bearing HR cells, tumor growth in groups treated with PGJ2 and delta 12-PGJ2 alone was significantly inhibited 63 days after tumor inoculation, compared to that in an untreated group. Consequently, a significant prolongation of median survival was obtained with delta 12-PGJ2, compared to that in untreated groups and in groups with cisplatin alone. In addition, when prostaglandins were administered together with cisplatin, adjuvant inhibitory effects on the tumor growth were obtained 35, 56 and 63 days after tumor inoculation. Subsequently a significant prolongation of median survival was observed when cisplatin was combined with PGD2 or delta 7-PGA1, compared to the results in groups treated with PGD2 alone, delta 7-PGA1 alone or cisplatin alone. Combination of PGJ2 or delta 12-PGJ2 and cisplatin resulted in a significant decrease of hematocrit and body weight 63 days after tumor inoculation, suggesting a deterioration of the median survival. These results suggest that combination of PGD2 or delta 7-PGA1 with cisplatin may be of clinical use for ovarian cancer resistant to cisplatin.

Animals

Modulation of human lymphocyte response to phytohemagglutinin by antineoplastic prostaglandins.

The effects of antineoplstic prostaglandins (PGs) (PGE1, PGE2, PGA1, PGA2, delta 7-PGA1, PGD2, PGJ2 and delta 12-PGJ2) on human peripheral blood lymphocyte (PBL) responses to phytohemagglutinin (PHA) were studied in vitro. All PGs used in this study alone had no mitogenic effect on the PBL. The PBL response to PHA was significantly stimulated at low concentrations (10(-7) and 10(-8) M) of the PGE series while the high concentration (10(-5) M) markedly inhibited the PHA response. PGA1 and PGA2, metabolites of the PGE series, and also delta 7-PGA1 stimulated the PHA response in a dose-dependent manner between 10(-6) and 10(-8) M, and showed a significant stimulatory effect at 10(-6) M while significantly inhibiting the PHA response at 10(-5) M. Similarly, 10(-6) and 10(-7) M (but not 10(-8) M) of PGD2 stimulated significantly the PHA response. PGJ2 and delta 12-PGJ2, which are metabolites of PGD2, also stimulated the PHA response in a dose-dependent manner between 10(-6) and 10(-8) M, and had a significant stimulatory effect at 10(-6) and 10(-7) M. The degree of the stimulatory effect was most marked with the PGD2 series among the antineoplastic PGs examined in this study. On the other hand, PGs (PGF1 alpha and PGF2 alpha) having no antineoplastic effect did not show such effects on the PHA response. These results suggest that antineoplastic PGs may have immunoregulatory effects through negative and positive feedback.

Antineoplastic Agents

Mother-to-infant transmission of hepatitis C virus.

Prospective studies of an infant of a mother infected with hepatitis C virus indicated that an HCV infection developed in the infant in early life. Perinatal transmission appeared to be the most likely explanation.

Female

Insulin sensitivity during very-low-calorie diets assessed by minimal modeling.

The time course of plasma glucose, insulin, and C-peptide after intravenous glucose (300 mg/kg body wt) injection was analyzed with minimal model approach in nine normal females and seven obese females. Glucose tolerance, estimated by glucose assimilation coefficient (KG), was positively correlated with glucose effectiveness (SG), but not correlated with peripheral insulin sensitivity (SI) in obese females as well as normal females. These factors were estimated before and after weight loss with 1.8-MJ (420-kcal) very-low-calorie diets (VLCDs) or with 2.5-3.3-MJ (600-800-kcal) low-calorie diets in two obese subjects. KG and glucose effectiveness decreased after acute weight loss with VLCD, although insulin sensitivity increased. Weight loss with low calorie diets resulted in improvement of KG and glucose effectiveness. These results suggest that a significant amount of glucose is taken up through insulin-independent mechanisms during the intravenous glucose tolerance test (ivGTT) in these subjects. This insulin-independent glucose uptake may be an important determinant of the fate of glucose in obese females as well as normal females.

Blood Glucose

The introduction of microvascular surgery to hepatic artery reconstruction in living-donor liver transplantation--its surgical advantages compared with conventional procedures.

Microvascular surgery for the reconstruction of the graft artery has been used since the 8th case in our series of 14 liver transplantations using living-related donors, and the clinical results have been compared between the first seven cases (the Loupe group) and the last seven cases (the Micro group). Seven arteries in 7 grafts were reconstructed with the use of loupe magnification in the Loupe group, while 8 arteries in 7 grafts were anastomosed with microscopic techniques in the Micro group. Statistically, there was no difference between the two groups in general background, including age, body weight and primary disease of the recipient, and in medical and surgical factors possibly relating to postoperative thrombosis of the hepatic artery. In two cases in the Loupe group, one or two additional reconstructions were necessary to obtain sufficient blood flow, while 8 arteries were anastomosed in the Micro group without any arterial complication in the postoperative period. There was no difference in time required for completing the arterial reconstruction (45.1 +/- 18.1 min in the Loupe versus 44.4 +/- 6.9 min in the Micro [mean +/- SEM]). Postoperative ultrasonic Doppler duplex study demonstrated a temporary decrease in the arterial flow in 2 cases of the Loupe group, and partial thrombosis of the artery was suspected. Additionally there were two episodes of hepatic artery thrombosis in 1 case of the Loupe group, in which emergent revision for thrombectomy and reanastomosis was performed at the first episode. This illustrated the higher incidence of arterial complications in the Loupe group compared with the Micro group (4 episodes/7 arteries in the Loupe versus 0/8 arteries in the Micro, P less than 0.05). In the present series there were no graft failures or arterial complications in the three deaths in the series. The clinical improvements achieved by microvascular surgery in living-donor liver transplantation suggest an alternative technical strategy for dealing with problematic arterial reconstruction in adult liver transplantation.

Child

Leiomyosarcoma of the uterus: ultrasonography and serum lactate dehydrogenase level.

Between January 1, 1979, and September 30, 1990, a total of 1,886 patients in the National Defense Medical College Hospital, a self-referred population, had a hysterectomy because of signs and symptoms presumably resulting from uterine myomas. After hysterectomy with presumed benign disease, a histologic diagnosis of leiomyosarcoma was made in 7 patients (0.37%). Preoperative diagnosis of leiomyosarcoma was not made in any of the 7 patients. However, serum lactate dehydrogenase levels were abnormally elevated in 3 of them, and degenerative changes were found within the tumor by ultrasonography in 5 of them. Furthermore, increased lactate dehydrogenase levels and degenerative changes within the tumor were found in 3 of the patients whose tumors had 10 or more mitoses per 10 high-power fields. The prognosis for the leiomyosarcomas with increased mitotic rates is very poor. Therefore, a degenerative change within the uterine mass and an increased lactate dehydrogenase level, when present, should suggest the diagnosis of leiomyosarcoma.

Adult

Effects of nicardipine on tube formation of bovine vascular endothelial cells in vitro.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the effect of nicardipine, a Ca2+ channel blocker, on angiogenesis in vitro. METHODS: Bovine carotid artery endothelial cells were cultured between type I collagen gel layers with 10(-9) to 10(-5) M nicardipine. The morphological changes were monitored by phase-contrast microscopy and photographed. The total length of tubular structures was measured with an image analyzer system. Endothelial proliferation and migration assays were also performed with the same doses of nicardipine. RESULTS: Cultured endothelial cells form tubular structures between collagen gel layers. Tube formation of endothelial cells was suppressed by culture with 10(-9) to 10(-5) M nicardipine in a dose-dependent manner. Migration of endothelial cells was also suppressed by the same doses of nicardipine. However, proliferation of endothelial cells was not enhanced. CONCLUSIONS: Nicardipine acts as an inhibitor of angiogenesis in vitro by inhibiting the migration of endothelial cells. This result suggests that nicardipine may have therapeutic potential in angiogenic disorders such as tumor growth, atherogenesis, and diabetic retinopathy.

Animals

Rapid morphological changes in bovine brain microvascular endothelial cells on extracellular matrices.

The morphological changes in endothelial cells derived from bovine brain microvasculature, carotid artery, and aorta during growth on extracellular matrices were compared. All cells formed tubular structures on a basement membrane. Ultrastructural studies showed that the tubular structures had lumens surrounded by many endothelial cells. On type I collagen gel, brain microvascular endothelial cells still formed tubular structures, but the other two cell types formed confluent monolayers. However, when a second layer of collagen gel was laid over these cells, tubular structures developed within 2-3 days. Brain microvascular endothelial cells form tubular structures more readily than endothelial cells derived from large vessels on both basement membrane and type I collagen gel.

Animals