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Biomedical subjects

T Tamaya

Publications and source records attributed to T Tamaya.

At least 19 recordsLinked to original sources
PubMed1992

Dehydroepiandrosterone sulfate-binding sites in plasma membrane from human uterine cervical fibroblasts.

Dehydroepiandrosterone sulfate (DHA-S) plays a critical role in cervical dilatation at labor. Incubation of cervical fibroblasts with [3H]DHA-S caused a rapid and saturable increase in cellular radioactivity: an apparent equilibrium was reached by 2 min. There was no detectable conversion of DHA-S into DHA or oestradiol. When the fibroblasts loaded with [3H]DHA-S were homogenized and fractionated, the specific radioactivity in the plasma membrane fraction was enriched approximately 8- to 9-fold compared with the whole homogenate; only low amounts of radioactivity were observed in the other subcellular fractions. The binding of DHA-S to plasma membrane preparations showed saturation kinetics with an apparent equilibrium dissociation constant (Kd) of 12 nM, and the binding capacity (Bmax) was calculated to be 1.25 fmol/mg protein. Neither DHA nor oestrone sulfate affected [3H]DHA-S binding to the plasma membrane. The plasma membranes of skin fibroblasts did not show specific binding sites for DHA-S. These findings demonstrate the presence of specific binding sites for DHA-S in the plasma membrane of cervical stroma cells. The fetal adrenal steroid may exert its action on cervical ripening at least in part through membrane-associated binding sites, or receptors.

Binding Sites↗
PubMed1992

Effect of medroxyprogesterone acetate on immunohistochemical expression of estradiol in endometrial carcinoma.

The effect of medroxyprogesterone acetate (MPA) on the immunohistochemical expression of estradiol (E2) was investigated in 25 cases of endometrial carcinoma. Twenty-three cases of the endometrial carcinomas showed positive immunoreactivity for E2. The immunohistochemical expression of E2 was more intensive in carcinoma cells than in stromal cells. Although the morphologic alterations induced by MPA treatment were observed only in 2 cases who were administered more than 30,000 mg of MPA, the staining intensity in most cases appeared to decrease after the treatment. The decrease in E2 immunoreactivities of cancer cells as well as of stromal cells in Grade 1 or Grade 2 was significant. These results suggest that MPA might decrease the E2 content in endometrial carcinoma cells as well as in stromal cells.

Endometrial Neoplasms↗
PubMed1992

Changes of silver-stained nucleolar organizer regions in mouse endometrial carcinogenesis induced by N-methyl-N-nitrosourea and 17 beta-oestradiol.

A high incidence of endometrial adenocarcinoma and pre-neoplastic lesions was induced in ICR mice treated with N-methyl-N-nitrosourea and 17 beta-oestradiol within 23 weeks. The endometrial lesions were histopathologically similar to those of human subjects. To assess the cell proliferative activity of these lesions, a one-step silver colloid staining for nucleolar organizer regions was applied and the numbers of silver-stained nucleolar organizer regions (AgNORs) were counted. The mean numbers +/- SD of AgNORs in each lesion were as follows: simple hyperplasia, 2.07 +/- 0.36; complex hyperplasia without cytological atypia, 2.79 +/- 0.39; complex hyperplasia with cytological atypia, 3.43 +/- 0.38; and well-differentiated adenocarcinoma, 4.17 +/- 0.40. Significant differences were observed in each lesion (P < 0.001). These findings suggest that the mean numbers of Ag-NORs are increased in the progression of neoplastic changes in the mouse endometrium, as in human endometrial lesions. This rapid induction model of endometrial carcinoma in mice is useful in the understanding of the histogenesis of endometrial carcinoma in human subjects.

Adenocarcinoma↗
PubMed1992

Scattering of the silver-stained proteins of nucleolar organizer regions in Ishikawa cells by actinomycin D.

Scattering of the silver-stained proteins of nucleolar organizer regions (Ag-NOR proteins) was produced by actinomycin D in Ishikawa cells. Scattering of Ag-NOR proteins was found only in cells treated with actinomycin D and various other agents had no effect. Scattering was dose-dependent up to 10(-2) micrograms/ml of actinomycin D, but it was not found at higher concentrations that caused marked inhibition of total DNA and RNA synthesis. Actinomycin D (10(-2) micrograms/ml) caused the following changes: (i) nucleolar segregation and (ii) emergence of dense fibrillar bodies in the nucleoplasm. Ag-NOR proteins were observed on the fibrillar centers and surrounding fibrillar components in control nucleoli, on the fibrillar and amorphous zones in segregated nucleoli, and on the dense fibrillar bodies emerging in the nucleoplasm. The scattering of Ag-NOR proteins was due to the argyrophilic nature of the dense fibrillar bodies. Actinomycin D (10(-1) micrograms/ml) also caused similar morphological alterations in the nucleolus and nucleoplasm, but Ag-NOR proteins were observed only on nucleolar remnants.

Antibiotics, Antineoplastic↗
PubMed1992

Neoadjuvant intraarterial infusion chemotherapy with a combination of mitomycin-C, vincristine, and cisplatin for locally advanced cervical cancer: a preliminary report.

Combination chemotherapy including cisplatin was administered intraarterially from the internal iliac artery as neoadjuvant chemotherapy to six patients with locally advanced uterine cervical cancer (stage higher than IIIB of FIGO). The drugs and doses were mitomycin-C 10 mg/m2, vincristine 1 mg/m2, and cisplatin 50 mg/m2. Two or three courses were repeated at intervals of 3 weeks. In three patients, dose reductions were undertaken for decreased renal function and thrombocytopenia. Partial response was, however, observed in all patients (response rate 100%), and five of six patients were able to undergo a radical hysterectomy. The major toxic effects were leukocytopenia, nausea, and vomiting. Our preliminary experience suggests that pelvic intraarterial infusion of combination chemotherapy is effective against primary and advanced uterine cervical cancer, and this preoperative treatment can lead to easier radical hysterectomy. However, further studies are warranted.

Aged↗
PubMed1992

Juvenile granulosa cell tumor in a 2-year-old infant: report of a case complicated with ascites and acute respiratory distress.

A two-year-old girl with a juvenile granulosa cell tumor (JGCT) and with acutely progressive hydrothorax and ascites is presented. She had precocious pseudopuberty and an elevated level of serum estradiol. Sudden onset of respiratory distress, due to a pleural effusion and severe abdominal distention, led to an emergency laparatomy. Unilateral salpingo-oophorectomy induced a rapidly favorable course. Histological examination showed no evidence of invasion or peritoneal metastasis. This is the first case of JGCT associated with an acute respiratory emergency as a main clinical feature.

Child, Preschool↗
PubMed1992

Estrogen binding sites in peripheral blood monocytes and effects of danazol on their sites in vitro.

1. This study was designed to investigate the presence of estrogen type I (high affinity, low capacity) and type II (low affinity, high capacity) binding sites in human peripheral blood monocytes and the effects of danazol on these sites. 2. These two types of estrogen binding sites existed in human peripheral blood monocytes. 3. Danazol bound to these sites in high concentration (10(-6) M, clinical serum concentration during danazol therapy) and decreased the number of both sites. 4. It is suggested that danazol has an anti-estrogenic action to the monocytes through the competition and suppression of estrogen binding sites as seen in the estrogen target organ.

Adult↗
PubMed1992

Expression of interleukin-1 (IL-1) beta messenger ribonucleic acid (mRNA) and IL-1 receptor antagonist mRNA in peritoneal macrophages from patients with endometriosis.

OBJECTIVE: To investigate the expression of interleukin-1 (IL-1) beta messenger ribonucleic acid (mRNA) and IL-1 receptor antagonist (IL-1ra) mRNA in peritoneal macrophages. DESIGN, SETTING: Peritoneal fluid (PF) samples were collected from patients who underwent laparoscopy or laparotomy. Northern blot analysis was performed at the reproductive research laboratory. PATIENTS: Twenty-six patients with endometriosis, 10 patients with postinflammatory pelvic adhesion, and 12 control women with normal pelvis. MAIN OUTCOME MEASURE: Polyadenylated RNA isolated from peritoneal macrophages was analyzed on Northern blots by using synthetic oligonucleotide probes. RESULTS: The level of IL-1 beta mRNA expression was elevated in the group with stage I endometriosis, whereas the increased expression of IL-1ra mRNA was observed in the group with stages III and IV endometriosis. The level of IL-1 beta mRNA showed a positive correlation with that of IL-1 beta in PF and a negative correlation with the level of IL-1ra mRNA. CONCLUSIONS: Our results suggest that peritoneal macrophages express IL-1ra mRNA rather than IL-1 beta mRNA with the progress of endometriosis and that peritoneal macrophages may secrete IL-1ra protein that modulates the effects of IL-1.

Adult↗
PubMed1992

Evidence of a role for phosphatidylinositol synthesis in human amnion cell proliferation.

Phosphatidylinositol (PtdIns) is the key precursor of phosphoinositide-derived intracellular mediators. The effects of changing the rate of PtdIns synthesis on mitogenic activity of human amnion-derived WISH cells were investigated. Incubation of the cells with [3H]inositol caused a time- and dose-dependent PtdIns labeling. Exogenous Ca2+ inhibited [3H]inositol incorporation in a dose-dependent fashion; half-maximal inhibition occurred with 0.3-1.0 mM Ca2+. In contrast, removal of cytosolic Ca2+ by ionophore A23187 and 1 mM EGTA induced enhancement of the PtdIns labeling as a function of A23187 concentration, perhaps through release of inhibitory effects of endogenous Ca2+. The A23187-stimulated PtdIns labeling with [3H]inositol was not abolished by additional unlabeled inositol, suggesting that [3H]inositol labeling of PtdIns occurred mainly through de novo synthesis catalyzed by PtdIns synthase (EC 2.7.8.11). In cells with PtdIns synthase activity decreased by exogenous Ca2+, [3H]thymidine incorporation was also inhibited, while A23187 caused dose-dependent enhancement of thymidine incorporation. The changes in PtdIns synthase activity occurred in parallel with changes in mitogenic activity caused by increasing the dose of exogenous Ca2+ or A23187. A similar lowering of mitogenic activity was observed upon suppression of PtdIns synthase by pemirolast potassium (9-methyl-3-1H-tetrazol-5yl-4H-pyrido[1,2-a]pyridin-4-one potassium) via a Ca(2+)-independent mechanism. These data demonstrate that changes in PtdIns synthase activity by some agents acting via different mechanisms are associated with parallel changes in thymidine incorporation, and suggest that PtdIns production is tightly coupled to cell proliferation in human amnion cells.

Amnion↗
PubMed1992

[Incidence of Mobiluncus spp. from the patients with clinical bacterial vaginosis].

Aerobic and anaerobic cultures as well as a Gram stain and wet mount preparations were made of vaginal swabs in twenty patients with clinical bacterial vaginosis. Mobiluncus spp. were detected in 7 cases (35%). Cultures appeared to indicate that mixed abnormal flora between aerobic and anaerobic bacteria are found in bacterial vaginosis, and that Mobiluncus spp. may play a role in bacterial vaginosis.

Adult↗
PubMed1992

Tight coupling of gonadotropin-releasing hormone receptor to stimulated phosphoinositide turnover and antigonadotropic action in granulosa cells.

Gonadotropin-releasing hormone (Gn-RH) stimulates phosphoinositide turnover by binding to its specific receptor and suppresses gonadotropin-dependent maturation and steroidogenesis in granulosa cells. This study was undertaken to determine whether persistent receptor occupancy was necessary for Gn-RH to exert such actions on rat granulosa cells, or whether Gn-RH actions were continued by a first and transient stimulation by Gn-RH, using a competitive antagonist, antide. Gn-RH stimulated [32P]phosphate incorporation into phosphatidylinositol (PtdIns), which could be terminated by displacement of previously bound Gn-RH from its receptor by antide and restarted by reoccupying the receptors with Gn-RH. Antide could prevent Gn-RH-stimulated PtdIns radiolabelling whenever it was added to incubations. An identical effect of antide was observed also in the anti-follicle-stimulating hormone (FSH) action of Gn-RH. FSH markedly stimulated aromatase activity, and Gn-RH caused a time- and dose-dependent inhibition of FSH action. Estrogen production was quenched by Gn-RH and restarted at a time when Gn-RH was removed from its receptor by antide. These two responses associated with the occupancy of Gn-RH receptor provide the evidence in favor of a tight coupling of stimulated PtdIns turnover to suppression of aromatase activation. These data of required continued activation of receptor might exclude the possibility that hypothalamic Gn-RH participated in the control of steroidogenesis in the ovary.

Animals↗
PubMed1992

Enhancement of growth-promoting activity in extract from uterine cancers by protein kinase C in human endometrial fibroblasts.

Uterine cervical and corpus cancers have been reported to synthesize and secrete a putative peptide mitogen, which elicits a potent proliferative response in fibroblasts by a mechanism independent of phosphoinositide turnover. The extract from human uterine cervical cancer stimulated [3H]thymidine incorporation into human endometrial fibroblasts in a dose-dependent manner. Concomitant exposure of the fibroblasts to thrombin or fibroblast growth factor (FGF) led to synergistic enhancement of the extract-stimulated [3H]thymidine incorporation into fibroblasts. An apparent maximal activity of the extract in the presence of thrombin or FGF was 2-fold higher than that in the absence of them, implying that thrombin or FGF acted at a stage after the interaction of the mitogen in the extract with its specific receptor. Insulin or epidermal growth factor failed to augment the growth-promoting activity in the extract. The stimulatory action of thrombin or FGF was mimicked by protein kinase C activators, phorbol-12-myristate-13-acetate (PMA) or 1-oleoyl-2-acetyl glycerol, but not by Ca2+ ionophore A23187. When the fibroblasts were first exposed to the extract for 4 h and then to PMA, PMA succeeded to augment the mitogenic activity in the same manner. The identical effects of protein kinase C activators with thrombin or FGF suggested that both types of ligand share a similar signaling cascade of action, activation of protein kinase C. These results demonstrated that the growth-promoting activity in uterine cancer extract could be enhanced by the agents which promote phosphoinositide metabolism through activation of protein kinase C. These findings could give a new insight into pathophysiology of the interaction between malignant cells and their stromal cells, fibroblasts.

Endometrium↗
PubMed1992

Successful outcomes of pregnancy complicated with dermatomyositis. Case reports.

There are few reports in the literature of pregnancy in dermatomyositis (DM), in contrast with those of other connective tissue diseases. We describe 2 patients who had an established diagnosis of DM and then became pregnant. In these cases, both the fetal and maternal outcome were good, and differed from those in previously reported cases.

Adult↗
PubMed1992

Incomplete testicular feminization syndrome: studies of 17 beta-oestradiol-binding activity and aromatase activity in cultured genital fibroblasts showing impaired dihydrotestosterone-binding.

Dihydrotestosterone (DHT) and 17 beta-oestradiol binding, and aromatase activity were measured in cultured genital skin fibroblasts from two siblings with the incomplete testicular feminization syndrome. Whole-cell and nuclear DHT binding in the cells from both patients were reduced to 80% and 60%, respectively of those in a normal male subject. The nuclear oestradiol binding was not impaired in the fibroblasts from the patients whose plasma oestradiol was normal or a little elevated. Although gonadectomy led to a decrease in plasma testosterone concentration, the concentration of testosterone-binding globulin showed no change suggesting no apparent effect on testosterone-binding globulin synthesis by testicular steroids. There was no significant difference in aromatase activity of the fibroblasts between the patients and the normal male subjects. The relatively increased oestrogen concentration in the syndrome might result from oestrogen production in testes, but is unlikely to be from peripheral tissues such as fibroblasts. This is the first report to examine oestradiol binding and aromatase activity in the cells from the incomplete testicular feminization associated with impaired DHT binding. These findings may give new insight into the pathogenesis of abnormal male sexual differentiation in the patients with testicular feminization syndrome.

Adult↗
PubMed1992

Effects of sex steroids on cell differentiation and interleukin-1 beta production in the human promyelocytic leukemia cell line HL-60.

The effects of 17 beta-estradiol (E2), progesterone (P) and testosterone (Te) on cell differentiation in the HL-60 promyelocytic leukemia cells after treatment with 1 alpha, 25-dihydroxyvitamin D3 [1,25-(OH)2D3] and those on interleukin-1 beta (IL-1 beta) production by HL-60 cells in response to lipopolysaccharide (LPS) were investigated. Neither E2 (10(-10) to 10(-7) M), P (10(-9) to 10(-6) M) nor Te (10(-10) to 10(-7) M) affected monocytic differentiation as assessed by reactivity with OKM14 monoclonal antibody and alpha-naphthyl acetate esterase activity. Pretreatment of HL-60 cells with 1,25-(OH)2D3 enhanced their ability to produce IL-1 beta in response to subsequent exposure to LPS, although 1,25-(OH)2D3 by itself did not induce IL-1 beta production by HL-60 cells. This priming effect of 1,25-(OH)2D3 was augmented by the addition of E2 and Te at physiologic concentrations, but not by that of P. E2, P and Te at physiologic concentrations enhanced IL-1 beta production by HL-60 cells that were pretreated with 1,25(OH)2D3 and stimulated by LPS. The increasing rate of IL-1 beta production by the addition of E2 and Te was higher when added with LPS than when added with 1,25-(OH)2D3. These findings suggest that enhancing effects of sex steroids in IL-1 beta production by monocyte/macrophage lineage cells.

Analysis of Variance↗
PubMed1991

Norethindrone scatters silver-stained nucleolar organizer regions of Ishikawa cells.

We investigated the effects of sex steroids on silver-stained nucleolar organizer regions (Ag-NORs) and DNA/RNA kinetics in Ishikawa cells. Norethindrone and its isomer norethynodrel exclusively caused Ag-NORs to scatter in the nuclear matrix, from the nucleolus. No such effect occurred with the other sex steroids tested, including progestational, androgenic, and estrogenic compounds. Nuclear argyrophilic substances induced by norethindrone, as well as nucleolar ones, were neither DNA nor RNA but protein. Electron microscopy showed that norethindrone caused nucleolar segregation, in which the fibrillar components disappeared, and it produced islets, consisting of dense fibrillar materials, in the nucleoplasm. Ag-NORs observed on the fibrillar components in control nucleoli were translocated onto the dense fibrillar materials in the nucleoplasm. Although scattering was preferentially found in the cells synthesizing DNA, the scintillation assay of DNA/RNA kinetics suggested that scattering was related to the inhibition of RNA synthesis. These results imply that norethindrone preferentially interacts with intranucleolar DNA when its duplication is occurring and then interferes with rRNA synthesis. Scattering of Ag-NORs might not be caused by the hormonal activity of these agents but by a pharmacological effect derived from their molecular structures.

Cell Line↗