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Biomedical subjects

Y Ibuki

Publications and source records attributed to Y Ibuki.

At least 109 records · Page 6Linked to original sources
PubMed1993

Effect of an activin A on follicle-stimulating hormone (FSH) receptor messenger ribonucleic acid levels and FSH receptor expressions in cultured rat granulosa cells.

Activin, a dimer of beta-subunits of inhibin, has been found to induce FSH receptor on cultured rat granulosa cells. The effect of activin on FSH receptor messenger RNA (mRNA) levels has not been elucidated. To study the effect of activin on FSH receptor mRNA levels, we used a specific complementary RNA probe to evaluate changes in FSH receptor transcripts in cultured rat granulosa cells. Granulosa cells obtained from immature diethylstilbestrol-treated rats contained two predominant FSH receptor mRNA transcripts (5.5 and 2.4 kilobases). Compared to the control, the treatment of granulosa cells with activin (100 ng/ml) increased FSH receptor mRNA in a time-dependent manner with a maximum of about a 4-fold increase at 24 h. FSH receptor mRNA markedly decreased after 48 h and maintained a level comparable to that found in the control. The FSH receptor expression was also increased by activin. Scatchard analysis of the binding of rat FSH to granulosa cells showed that the increase in FSH binding after activin treatment was due to an increase in the receptor number and not the affinity of binding. Treatment of granulosa cells for 24 h with activin (20-300 ng/ml) increased FSH receptor mRNA in a dose-dependent manner to a maximum of about a 4-fold increase at a concentration of 100-300 ng/ml. We analyzed rat type II activin receptor mRNA transcripts in cultured rat granulosa cells with a specific complementary RNA probe to study the action of activin on granulosa cells. Granulosa cells contained two predominant rat type II activin receptor mRNA transcripts (6.0 and 3.0 kilobases). Furthermore, we measured intracellular cAMP production by activin to examine the mechanism by which activin acts on granulosa cells. In result, activin alone did not increase intracellular cAMP accumulation. In conclusion, this study demonstrates that the effect of activin A on the induction of FSH receptor expression is associated with a change in FSH receptor mRNA levels, suggesting that modulation of follicle development occurs.

Activins↗
PubMed1993

Example of a woman with multiple intrauterine deaths due to anti-M who delivered a live child after plasmapheresis.

Serological and hematological investigations are reported for a woman who had multiple intrauterine deaths due to anti-M. The mother was group O Ns and the husband's cells were shown to be group O MSs. In the serological examination during the third pregnancy anti-M antibodies were identified in her serum. The antibodies comprised IgM saline agglutinin at a titer of 256 at 4 degrees C and IgG agglutinin reacted in an indirect antiglobulin technique at a titer of 4,096 at 37 degrees C. After the intrauterine death at 14 weeks gestation of her fifth pregnancy she underwent plasmapheresis 6 times on a biweekly program. Approximately 2 liters of plasma were exchanged for 1 liter of plasma protein fraction and 1 liter of fresh frozen plasma. In her sixth pregnancy, intensive plasmapheresis was started from 2 months gestation and a total of 56 liters plasma were exchanged. The anti-M titer fell to 256. She delivered a live girl by induction of labor at 35 weeks. The child was group O MNs. Her red cells had a positive direct antiglobulin reaction and her serum contained IgG anti-M antibody. Phototherapy was carried out and the child developed normally.

Adult↗
PubMed1993

[The preventive effect of estrogen and vitamin D on postmenopausal bone loss].

In order to evaluate the preventive effect of estrogen and vitamin D3 on postmenopausal bone loss, either estrogen (Premarin 0.625 mg/day) or vitamin D3 (Onealfa 1.0 micrograms/day) was administered to postmenopausal women. Changes in lumbar bone mineral density (BMD) were monitored by dual energy X-ray absorptiometry (DEXA). The lumbar BMD of women given estrogen showed a significant increase at 6 months after treatment. The highest response to estrogen was demonstrated within a year after treatment, and thereafter the effect was diminished but still prevented further bone loss. On the other hand, the effect of vitamin D was heterogeneous. Half of the women receiving vitamin D showed a remarkable increase at a year later, but in the remainder there was a decrease and the overall there was little change from the pretreatment value. These results indicate that estrogen can be used as a first choice for the prevention of postmenopausal bone loss, but further studies on the preventive effect of vitamin D are needed.

Absorptiometry, Photon↗
PubMed1992

Cloning and sequencing of a rat type II activin receptor.

A full-length cDNA for a rat type II activin receptor was cloned by hybridization from a rat ovary cDNA library. The deduced amino acid sequence (513 residues) containing a single membrane-spanning domain and an intracellular kinase domain with predicted serine/threonine specificity. The amino acid sequence is 99.8% and 99.4% identical in the coding region with the previously cloned mouse and human type II activin receptor, and only 66.7% identical in the coding region with the previously cloned rat type IIB activin receptor. We examined the effect of PMSG-hCG on the mRNA level of type II activin receptor in immature rat ovaries. Northern blot analysis of ovarian RNA revealed two mRNAs (3.0 kb and 6.0 kb).

Activin Receptors↗
PubMed1992

Prediction and prevention of ovarian hyperstimulation by monitoring endogenous luteinizing hormone release during purified follicle-stimulating hormone therapy.

OBJECTIVE: To elucidate whether early detection of premature luteinizing hormone (LH) release can be useful for prediction and prevention of ovarian hyperstimulation during purified follicle-stimulating hormone (FSH) therapy. DESIGN: Retrospective and prospective study. PATIENTS: Infertile women with polycystic ovarian syndrome. MAIN OUTCOME MEASURES: Correlation between rate of endogenous LH release and incidence of excessive ovarian enlargement. In the prospective study, LH was measured by fluorometric enzyme immunoassay to obtain real-time concentration. Maximal ovarian diameter by ultrasonography. RESULTS: The rate of excessive ovarian enlargement (greater than or equal to 60 mm) in cycles that were treated by a daily administration of purified FSH and accompanied by premature LH release was 83.3%. This rate was significantly higher than that in cycles without premature LH release (24.1%, P less than 0.001). Interruption of FSH administration or alternate day FSH administration in cycles with premature LH release reduced the rate of ovarian enlargement to 45.5% (P less than 0.05). CONCLUSION: Early detection of premature LH release is useful for prediction of ovarian hyperstimulation. Ovarian hyperstimulation can be reduced by modulating the dose of FSH and the interval of administration in cycles with premature LH release.

Female↗
PubMed1992

Small hepatocellular carcinoma: diagnosis with US angiography with intraarterial CO2 microbubbles.

Ultrasonographic (US) angiography enhanced with intraarterial CO2 microbubbles, a contrast material used in US imaging, was performed of 103 histologically proved hepatocellular carcinomas (HCCs) smaller than 3 cm in diameter in 95 patients. The detection rate for hypervascular HCC with US angiography was compared with the rate of detection with conventional angiography, digital subtraction angiography (DSA), and computed tomography (CT) after intraarterial injection of iodized oil. Sensitivity in detection of hypervascular HCCs with US angiography was 86% (89 of 103 HCCs), compared with 63% (44 of 70 HCCs) detected with conventional angiography, 70% (23 of 33 HCCs) with DSA, and 82% (75 of 91 HCCs) with CT with iodized oil. US angiography depicted small hypervascular HCCs, especially those less than 1 cm in diameter, and helped clarify vascularity as isovascular or hypovascular in angiographically undetectable HCCs. Findings at US angiography assisted the choice of a therapeutic strategy for treatment of HCC, such as transarterial therapy, percutaneous ethanol injection therapy, or resection.

Angiography, Digital Subtraction↗
PubMed1992

Association of immunoreactive-inhibin levels with luteal function.

To evaluate immunoreactive (IR) inhibin as a marker of corpus luteal function, 134 women with natural ovulatory cycles were studied. Serum IR-inhibin levels during the luteal phase were significantly lower in women with low progesterone (P4) levels (less than 10 ng/ml). Endometrial dating correlated more with serum P4 than IR-inhibin levels. All 14 conceiving cycles showed serum P4 levels greater than or equal to 10 ng/ml and IR-inhibin levels greater than or equal to 3.67 IU/ml during the midluteal phase. Furthermore, IR-inhibin levels in the early follicular phase seemed to be associated with lowered P4 levels in the ensuing luteal phase. These results suggest that IR inhibin may be closely related to corpus luteum function.

Adult↗
PubMed1992

Further observations on serial serum immunoreactive inhibin levels in the luteal phase and early gestation after ovarian stimulation for in vitro fertilization and embryo transfer.

Serum immunoreactive inhibin of the luteal phase was measured by radioimmunoassay in 71 patients in vitro fertilization and embryo transfer (IVF-ET). The correlation between the pregnancy outcome and the serial inhibin pattern from the luteal phase to early gestation was studied. In nonconception cycles (n = 35), serum inhibin concentration rose and reached a peak level around 5 or 6 days after oocyte pick-up (OPU), then fell to the level of the early follicular phase. In conception cycles (n = 22), serum inhibin levels rose again 10-15 days after OPU. Serum inhibin levels were significantly higher from 10 days after OPU in multiple pregnancy (n = 5) than in single pregnancy (n = 17). In viable single pregnancy (n = 17), serum inhibin levels were significantly higher than in non-viable pregnancy (n = 14) from 15 days after OPU. Serum inhibin levels in early gestation correlated well with the pregnancy outcome of IVF-ET. These data suggest that inhibin is an important factor for the diagnosis of pregnancy outcome.

Abortion, Spontaneous↗
PubMed1992

In vivo action of activin-A on pituitary-gonadal system.

Activin, a dimer of the beta-subunits of inhibin, has been found to stimulate FSH secretion from the cultured pituitary cells. However, in vivo action of activin is poorly elucidated. Daily sc injections of 40 micrograms activin-A over a period of 1-3 days to intact immature female rats caused a significant increase in serum FSH, inhibin, estradiol, uterine weight, and ovarian FSH receptors. Daily sc injections of 5 micrograms or 20 micrograms activin-A for 6 days caused a marked increase in ovarian weight and the development of large ovarian follicles. However, daily sc injections of 20 micrograms activin-A to hypophysectomized immature female rats for 3 days induced no significant changes in ovarian and uterine weight, serum inhibin, estradiol, and progesterone levels. Simultaneous injections of both activin-A and 5 IU PMSG induced a significant increase in ovarian and uterine weight, serum inhibin, and estradiol levels, compared to simultaneous injections of both vehicle and PMSG in the hypophysectomized immature female rats. These results demonstrate that activin-A induces not only an increase of FSH secretion from the pituitary but also a direct autocrine or paracrine ovarian stimulation resulting in an increase of the number of ovarian FSH receptors and ovarian and uterine weight, as well as an increase in the level of inhibin and estradiol secretion from the ovary.

Activins↗
PubMed1992

Sonography with intraarterial infusion of carbon dioxide microbubbles (sonographic angiography): value in differential diagnosis of hepatic tumors.

Differential diagnosis of small liver tumors is important, but is not always possible, even with angiography. To solve this problem, we introduced sonographic angiography, which combines sonography and angiography. The vascular pattern of a variety of hepatic nodules was evaluated with sonographic angiography, and the results were compared with those of conventional angiography. Sonographic angiography (sonography performed during intraarterial infusion of carbon dioxide microbubbles) was performed in 184 patients with a total of 222 hepatic nodules: 139 hepatocellular carcinomas, nine adenomatous hyperplasias, seven regenerative nodules, 21 hemangiomas, 33 metastases, seven lymphomas, one granuloma, and five focal nodular hyperplasias. Sonographic angiography detected a hypervascular pattern with peripheral blood supply in cases of hepatocellular carcinoma (sensitivity, 90%; specificity, 89%). Typical vascular patterns of adenomatous hyperplasia, hemangioma, metastasis, and focal nodular hyperplasia on sonographic angiography were hypovascularity (sensitivity, 100%; specificity, 91%), spotty pooling (sensitivity, 100%; specificity, 100%), peripheral hypervascularity (sensitivity, 64%; specificity, 100%), respectively. The detectability of hypervascularity was greater with sonographic angiography than with conventional angiography in hepatocellular carcinoma, metastasis, and hemangioma. Our experience indicates that sonographic angiography depicts characteristic vascular features that reflect the vascular anatomy of specific types of hepatic tumors, and thus is useful in the differential diagnosis of these lesions.

Carbon Dioxide↗
PubMed1992

Des-gamma-carboxy prothrombin (PIVKA-II) and alpha-fetoprotein-producing IIc-type early gastric cancer.

We describe the case of a 56-yr-old man with primary gastric adenocarcinoma, who had an extremely high plasma level of des-gamma-carboxy prothrombin (2.45 AU/ml) and of serum alpha-fetoprotein (2810 ng/ml). Histopathologically, the gastric cancer was a IIc type of early cancer which consisted of a combination of a poorly differentiated adenocarcinoma and a well-differentiated tubular adenocarcinoma. The association of a hepatic tumor including hepatocellular carcinoma or liver metastasis was ruled out by ultrasonography, computed tomography, radiocolloid liver scan, magnetic resonance imaging, and angiography. Foci strongly resembling hepatocellular carcinoma (hepatoid differentiation) were noted in the gastric tumor. Localization of des-gamma-carboxy prothrombin and alpha-fetoprotein within the tumor cells, especially within the hepatoid differentiated foci, was demonstrated by the immunohistochemical staining of tissue obtained at biopsy and the resected specimen. This case seems to be the first case reported in which des-gamma-carboxy prothrombin was produced by the gastric cancer. This finding supports the theory of hepatoid differentiation of a gastric cancer.

Adenocarcinoma↗
PubMed1992

[Maintenance chemotherapy using UFT and FT for gynecological malignant tumors. The Gunma Prefectural Society for Study of Chemotherapy for Gynecological Cancer].

The Gunma Prefectural Society for Study of Chemotherapy for Gynecological Cancer made a comparative study on postoperative supplementary chemotherapy including UFT and FT-E for gynecological malignant tumors. The number of cases registered totaled 182, which was broken down into ovarian cancer 53 cases, uterine cervical cancer 89 cases and endometrial cancer 30 cases. Complete cases among them consisted of ovarian cancer 53 cases, uterine cervical cancer 86 cases and endometrial cancer 27 cases for a total of 166 cases. Ovarian cancer was stratified into the completely and incompletely removed cases, uterine cervical cancer into postoperative non-irradiated and irradiated cases and endometrial cancer into the positive metastasis (+) group and negative metastasis (-) group. Then the UFT administration group and FT-E administration group were compared for postoperative survival. There were control groups for both ovarian and endometrial cancer. UFT administration showed a significant improvement in the survival rate (P < 0.05) compared to the FT-E administration group in the cases of ovarian cancer completely removed and the cases of endometrial cancer irradiated after operation. No significant difference was observed between other groups compared. The incidence of side effects was 20.6% (20/97) in the UFT administration group and 3.6% (2/55) in the FT-E group. Neither group showed any serious side effects.

Adult↗
PubMed1992

Endometrial dating in the conception cycle.

OBJECTIVE: To investigate endometrial dating during the conception cycle. DESIGN: Endometrial biopsies of the last half of the luteal phase of conception cycles were dated based on urinary luteinizing hormone (LH) surges. SETTING: Endometrial samples were obtained from women attending the fertility clinic of the Department of Obstetrics and Gynecology at Gunma University Hospital. PATIENTS: One hundred eighty-five women, of whom 15 (8.1%) conceived during this study. MAIN OUTCOME MEASURES: Urinary LH surge, serum progesterone (P) levels, and endometrial dating. RESULTS: All 10 women who conceived showed 2 or within 2 days in-phase endometrial biopsies on days 7 to 11 after the LH surge. In 4 of 5 women biopsied on day 12, an unequivocally delay in the stroma was found, i.e., a persistence of edema and poor development of predecidual reaction. Since serum P levels in conception cycles were significantly higher than in nonconception cycles on days 10, 11, and 12, we interpreted this delay in the stroma as a consequence of conception. CONCLUSION: Endometrial specimens during the last half of the luteal phase of conception cycles are in-phase until day 12. On day 12, gestational hyperplasia causes apparent out-of-phase.

Adult↗
PubMed1992

[Clinical utility of receptor imaging in the assessment of liver function].

Technetium-99m diethylene triamine pentaacetic acid-galactosyl human serum albumin (TcGSA) is a newly developed receptor-binding radiopharmaceutical, specific for the asialoglycoprotein receptor, which resides exclusively on the plasma membrane of hepatocytes. Clinical utility of TcGSA was evaluated in 3 control subjects with normal livers and in 54 patients with various liver diseases. The parameter, Receptor Index, was derived from liver and heart time-activity data and is the ratio of radioactivity of the liver over the radioactivity of the liver plus heart at 15 min after the intravenous injection of 3 mg of TcGSA. Receptor concentration ([R]o) was obtained by kinetic analysis of liver and heart time-activity data using pharmacokinetic nonlinear modeling. Values for the Receptor Index and [R]o was statistically different in the control subjects and in patients with mild, moderate, and severe liver diseases. Good correlations were obtained between the Receptor Index, [R]o and conventional liver function tests, such as Child-Turcotte criteria score, prothrombin time, and indocyanine green test. Receptor Index and [R]o were properly estimated even in patients with obstructive jaundice or remarkable portocaval shunt. These data suggest that the receptor imaging as well as its parameters, Receptor Index and [R]o, is a potentially practical and reliable diagnostic method for estimating the functioning hepatocyte mass and for assessing liver function.

Adult↗
PubMed1992

[Hepatic receptor imaging with Tc-99m GSA: estimates of liver function in acute liver disease].

Technetium-99m galactosyl human serum albumin (TcGSA) is a synthesized radiolabeled analog ligand to asialoglycoprotein receptor, which resides only at a mammalian hepatocyte. TcGSA studies were performed on 16 patients with various acute liver disease and 3 controls with normal livers. Dynamic data were obtained by a gamma camera during 35 minutes after an intravenous injection of 3 mg (185 MBq) of TcGSA. The parameters of TcGSA time activity curves were obtained by dividing radioactivity of the liver by that of the liver plus heart at 15 min (Receptor Index), and by dividing radioactivity of the liver at 15 min by that at 3 min post injection (Clearance Index). The two parameters correlated well with prothrombin time, clinically estimated staging, and severity of acute liver disease. We have concluded that liver function study by the newly developed receptor imaging with TcGSA can be a sensitive and promising tool in estimating the severity and prognosis of acute liver disease.

Acute Disease↗
PubMed1991

Cloning and sequencing of human FSH receptor cDNA.

We have isolated and sequenced a cDNA encoding the follicle stimulating hormone (FSH) receptor. The deduced amino acid sequence (678 residues) containing seven putative transmembrane segments which displays sequence similarity to G protein-coupled receptors. The receptor consists of 359 residue extracellular domain which contains four N-linked glycosylation sites. While the protein is 89% identical overall with the previously cloned rat FSH receptor, the most highly conserved regions are the putative transmembrane segments (95% similarity).

Amino Acid Sequence↗