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N Furuta

Publications and source records attributed to N Furuta.

At least 91 records · Page 5Linked to original sources
PubMed1977

Progesterone receptor in human endometrium of leiomyoma uteri.

This study was designed to examine whether 8S protein as progesterone receptor exists in the human endometrium which has been primed with estrogen. The kinetic study showed that 8S-progesterone binding was specific with Kd of 2.0 X 10(-9) M. 5S-progesterone binding was inhibited competitively by cortisol. The study of ligand specificity also showed that progesterone and its related steroids had much stronger affinity for 8S component than for 5S component. Therefore, 5S protein may be CBG. Progesterone-8S protein binding was easily dissociated during the 5-20% sucrose gradient centrifugation, but such a protein from which progesterone had been dissociated could be sedimented at 8S region. Glycerol could stabilize progesterone-8S protein binding. These results indicate the existence of 8S protein as a progesterone receptor under the low salt medium in the estrogen primed human endometrium.

Endometrium↗
PubMed1976

Echocardiography and angiocardiography for detection of left atrial thrombosis.

Diagnostic capabilities for detection of the left atrial clot in patients with mitral stenosis were compared between echocardiography and angiocardiography. Large clots in the left atrial body were correctly diagnosed either by echocardiography or by angiocardiography. Clots in the left atrial appendage were not disclosed by echocardiography. Left atrial visualization with pulmonary arteriography offers only possible diagnosis of the clot in the appendage. Definite diagnosis of the clot in this location requires transseptal left atriography.

Angiocardiography↗
PubMed1976

The mechanism of action of the copper intrauterine device.

The effects of copper ions on the binding of steroids to receptors revealed that the inhibitory effect of Cu++ was apparent at 10(-6)M, ANd the binding capacities decreased to 10% at 10(-2)M Cu++. The kinetic study demonstrated that Cu++ was a competitive inhibitor of steroid hormone-receptor binding (Ki divided by 2.7 X 10(-5)M to estrogen receptor; Ki divided by 5.1 X 10(-6)M to progesterone receptor). These results indicate that copper ions interfere at the steroid-binding site of receptor and that progesterone receptor is more affected by copper ions than is estrogen receptor. The sedimentation pattern showed the dissociation and aggregation of receptor macromolecules by copper. These phenomena may indicate the biologic inactivation of receptor. In fact, morphologically, progestational proliferation was severely inhibited and estrogenic action seemed to be inhibited. The Timm stain showed copper uptake by endometrial epithelium and superficial stromata. The copper content apparently increased in the cytoplasm of uteri bearing a copper intrauterine device, compared with controls. In vivo, the concentration of cytoplasmic copper was approximately 1.4 X 10(-6)M, which was obviously inhibitory to steroid hormone-receptor interaction. However, complete morphologic suppression of the progestational effect by copper cannot exclude the coexistence of some other mechanism in these phenomena.

Animals↗
PubMed1975

[Interaction of norethindrone on estrogen and progesterone receptors in the rabbit uterine cytosol (author's transl)].

Norethindrone (ENT), which is a representative in estrane series of progestogen, is not only strongly progestational but also estrogenic and in some cases, antiestrogenic. To understand progestational effect and antiestrogenic effect, the interactions of ENT on estrogen and progestogen receptors were studied in the uterine cytosol of white female rabbit. The 274,200 X G supernatant of uterine homogenate was used as cytosol. 3H-Estradiol, 3H-Progesterone, 3H-ENT or cold ENT were incubated with uterine cytosol at 4 degrees C for 2 hours. Results are as follows: 1. Sucrose gradient centrifugation [5 approximately 20% linear and 40,000 rpm (159,200 X G) for 16 hours at 4 degrees C]: ENT was bound to extrogen 8S receptor in immature rabbit uterus (Fig. 2 & 3), and to progestogen 8S receptor in estrogen primed rabbit uterus (Fig. 5). 2. Kinetic study, determined by dextran coated charcoal (0.001% dextran and 0.1% charcoal): (1) In the uterine cytosol of immature rabbit, 3H-estradiol-receptor binding was observed with Kd divide by 3.6 X 10-9 M and it was revealed that ENT was a competitive inhibitor to this binding with Ki divide by 2.6 X 10-6 M, as in Fig. 6. (2) 8S component, obtained by centrifugation of uterine cytosol (Fig. 1) in estrogen primed rabbit, binds 3H-progesterone with Kd divide by 8.1 X 10-10 M and Bm (maximal binding sites) divide by 5.0 X 10-8 M/mg of protein, and ENT was a competitive inhibitor in this binding with Ki divide by 2.3 X 10-9 M (FIG. 7 & 8). 3H-ENT-8S binding was demonstrated with Kd divide by 1.1 X 10-9 M and Bm divide by 8.7 X 10-8 M/mg of cytosol protein (Fig. 8). These results indicate: (a) ENT is bound to both estrogen and progestogen receptors in 8S macromolecules of uterine cytosol, (b) competitive inhibition of ENT to these bindings indicated that ENT is bound to these receptors at the steroid binding sites where estradiol and progesterone bind to, (c) ENT has much more affinity to progestogen receptor (Ki divide by 2.3 X 10-9 M) than to estrogen receptor (Ki divide 2.6 X 10-6 M), (d) while ENT is bound to progestogen and estrogen receptors at the same time, Bm of ENT (8.7 X 10-8 M/mg of cytosol protein) is more than Bm of progesterone (5.0 X 10-9 M/mg of cytosol protein), and Kd of ENT (1.1 X 10-9 M) was less than Ki of ENT (2.3 X 10-9 M) in the binding to progesterone-receptor. Biologically, while ENT is bound to progestogen -receptor with high affinity and to estrogen receptor with low affinity, ENT is actually progestational in low dose and antiestrogenic in high dose but the anti-estrogenicity seems to be incomplete in vivo as ENT may be metabolized to a potent estrogenic compound, ethinyl estradiol

Animals↗
PubMed1975

[Studies on progesterone receptor in rabbit uterine cytosol -- nuclear translocation and chromatin binding-- (author's transl)].

Estrogen priming increases uterine 8S macromolecule which binds progesterone specifically. Progesterone-8S complex in the cytoplasm enters into nucleus and is bound to chromatin finally. In this paper, the mode of nuclear translocation of steroid in exchange assay of receptor introduced by Anderson et al., and the mode of binding to chromatin were studied on the progesterone-receptor complex in the uterus of estrogen primed female rabbit. 1. After intravenous administration of 200 mug progesterone into the estrogen primed immature rabbit, uterine nuclei were prepared by the method in Table 1. These nuclei were incubated with 3H-progesterone and cold steroids at 4 degrees C for 30 minutes, and then washed with buffer A. The radioactivity of the nuclei was counted. This experiment was performed at 4 degrees C because progesterone receptor and chromatin were observed to be degraded at 37 degrees C for 20 minutes. The effect of cold steroids in vitro on the incorporation of 3H-progesterone into the uterine nuclei of rabbit pretreated with progesterone was found to be similar to their effect on progesterone-receptor binding in cytosol or chromatin (Fig. 1). 2. The effect of cold steroids on 3H-progesterone-receptor-chromatin triplex (Table 2 and Fig. 2) was examined. Once 3H-progesterone-receptor-chromatin triplex was formed, it was difficult to exchange 3H-progesterone to other steroids at 4 degrees C. These results (1 & 2) indicate that progesterone-receptor complex enters into nucleus and is bound to chromatin. Exchange of steroid may occur in the nuclear progesterone-receptor complex, which is free from the binding with chromatin. And thus exchange assay cannot represent quantitative data on receptor content. 3. 3H-progesterone-8S or 5S complexes were obtained by 5 approximately 20% sucrose linear gradient centrifugation (Fig. 3). The same molar concentration of these complexes from estrogen primed or castrated rabbit uterus were incubated with primed uterine chromatin for 30 minutes. Then the chromatin was washed with buffer A and the radioactivity was counted. It was shown in Fig. 4 that 3H-progesterone-8S complex was bound to chromatin much more tightly than 3H-progesterone 5-S complex in preparations obtained from both castrated or primed uterine cytosols. All these results indicate that 8S may be the biologically active form of the receptor. 4.3H-progesterone uptake into uterine nuclei was observed in very limited amount following the injection into uterine artery. The radioactivity in nuclei decreased easily by washing with buffer A as in Fig. 5. The small amount of residual radioactivity after washing, that is, very limited number of binding sites with high affinity is considered to be indicative of biologically active binding.

Animals↗
PubMed1975

[The effect of metallic ions on steroid hormone receptors in the rabbit uterus (author's transl)].

The copper-IUD has been proved to be more effective for contraception than the popular IUD. To understand this mechanism of action, the effects of metallic ions on estrogen and progesterone receptors were examined in the cytosol of estrogen primed with female rabbits. The 274,200 X G supernatant of the uterine homogenate was used as the cytosol. The cytosol and 3H-progesterone (3.12 X 10(-9)M) or 3H-estradiol-17 beta (3.46 X 10(-9)M), with or without various metallic ions of different concentrations had been incubated for 2 hours. Bindings of steroids were estimated by the dextran coated charcoal assay (0.001% dextran and 0.1% Norite A) and were evaluated by 5 approximately 20% sucrose linear gradient centrifugation 1) Effect of various metallic ions on steroid hormone-receptor binding (determined by dextran coated charcoal assay. Fig. 1) : Thesteroid hormone-receptor interactions were markedly inhibited by Cu++, Fe++, and Zn++ ions and moderately by Mn++, but K+ and Ca++ increased of slightly affected the binding at concentrations between 10(-2)M and 10(-4)M. There were some differences between estrogen and progesterone receptors in their sensitivities to various metallic ions. 2) The effect of copper ion on the binding of steroid to the receptor : The dextran coated charcoal assay (Fig. 2) demonstrated that the inhibitory effect of Cu++ appeared at 10(-6)M and the steroidhormone-receptor bound decreased down to 10% at 10(-2)M Cu++. The estrogen receptor was less affected by copper than the progesterone receptor. It was demonstrated by 5 approximately 20% sucrose linear gradient centrifugation (Fig 3) that estrogen and progesterone receptors, which both sedimented at 8 S, were changed to more sedimenting forms in the presence of 10(-4)M Cu++, and were dissociated to 6.5 S form with moderate loss of steriod hormone binding affinity in 10(-2)M Cu++. The kinetic study (Fig 4), determined by dextran coated charcoal, showed that Cu++ was a competitive inhibitor against steroid hormone receptor bindings with Ki in equilibrium 2.7 X 10(-5)M to estrogen receptor (Kd in equilibrium 1.4 X 10(-9)M), and with Ki in equilibrium 5.1 X 10(-6M to progesterone receptor (Kd in equilibrium 8.1 X 10(-10)M). These results indicate the inhibiting factor of copper is the direct interference at the steriod binding site of the receptor, resulting in the increase in the effectiveness of the IUD. While progesterone receptor is more affected by copper ion than estrogen receptor, it is suggested that estrogen receptor survives longer than progesterone receptor and thus the biolgoical effect of copper seems to be somewhat estrogenic.

Animals↗
PubMedDate not supplied

Peripheral primitive neuroectodermal tumor of the vulva: report of a case with imprint cytology.

BACKGROUND: Peripheral primitive neuroectodermal tumor (PNET) of the vulva is an extremely rare disease, and, to our knowledge, only two cases have been previously reported. CASE: A 45-year-old woman presented with a mass in the right labium major. Three years after removal of the tumor, she noticed a new lesion in the same place and underwent a partial vulvectomy. The imprint cytology of the recurrent tumor showed a monomorphic appearance, composed of small round cells with scant cytoplasm against a hemorrhagic background. These tumor cells were loosely connective, but rosettelike structures were observed focally. On pathologic examination, the neoplasm was composed of small round tumor cells showing sinusoidal, diffuse or micropapillary growth. Immunohistochemically, the neoplastic cells stained positively for neuron-specific enolase, vimentin and HBA 71 and negatively for cytokeratin, HBA 45 and muscle-specific actin. The morphologic characteristics of the disease were well expressed in the imprint cytology, and this influenced the selection of immunohistochemical studies. CONCLUSION: Cytologic examination for vulvar tumors, even imprint cytology, can be a useful tool in obtaining an accurate pathologic diagnosis of a rare disease, such as peripheral PNET.

Antigens, Neoplasm↗
PubMedDate not supplied

Initial experience of percutaneous renal cryosurgery under the guidance of a horizontal open MRI system.

OBJECTIVE: The aim of this study was to obtain preliminary results of cryoablation of renal tumors by using a percutaneous approach guided by a horizontal open MRI system, and to assess the safety and efficacy of this procedure. MATERIALS AND METHODS: Four patients with renal tumors underwent percutaneous cryosurgery with local anesthesia using a horizontal open MRI system (AIRIS II, Hitachi Medical Corp., Tokyo, Japan). The size of the mass was radiographically documented as 4 cm or less in diameter. A 2- or 3-mm cryoprobe was advanced into the renal mass under real-time MR monitoring. Growth of the iceball during cryoablation was monitored by two-dimensional MR images. Follow-up dynamic CT and physical examination were done after two weeks and six weeks. RESULT: MR imaging demonstrated the iceballs as sharply marginated regions of signal loss that expanded and engulfed the renal mass with clear contrast between the iceball and surrounding tissue. Cryoablated tumors resolved, and there were no serious complications and no clinically significant changes during the procedures and follow-up study. CONCLUSION: In this limited clinical trial of percutaneous renal tumor surgery, cryoablation demonstrated its feasibility with minimal morbidity. Intraprocedual MR-guided cryosurgery can be used as a safe modality, although further studies are necessary to determine the long-term efficacy of this procedure.

Aged↗