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Biomedical subjects

Y Ibuki

Publications and source records attributed to Y Ibuki.

At least 127 records · Page 7Linked to original sources
PubMed1991

Hormonal regulation of gonadotropin receptor mRNA in rat ovary during follicular growth and luteinization.

To investigate the regulation of the follicle-stimulating hormone (FSH) and luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor genes by gonadotropins, we examined the effect of pregnant mare's serum gonadotropin (PMSG) or PMSG-hCG on the expression of FSH and LH/hCG receptors in rat ovaries. After administration of PMSG, Northern blot analysis using the FSH receptor cDNA probe revealed that a major band of 2400 nucleotides was detected which reached the maximal level on day 3. On the other hand, the level of LH/hCG receptor mRNA, a major mRNA of 5400 nucleotides and minor species of 7500, 3600, 2300 and 1200 nucleotides, increased progressively during 4 days. Treatment with hCG resulted in a decrease of FSH and LH/hCG receptor mRNA levels, and the level of FSH receptor mRNA was completely suppressed. Although the level of LH/hCG receptor mRNA was also suppressed from 3 h to an almost undetectable level at 24 h after hCG injection, it recovered to the control level by 48 h and exceeded this level several fold by 72 h. The reappearance of LH/hCG receptors following desensitization was preceded by an increase in mRNA levels. These studies demonstrate that hormonal regulation of gonadotropin receptor mRNAs on rat ovary reflects the changes in gonadotropin receptor levels.

Animals↗
PubMed1991

Immunoreactive inhibin concentrations in adult men: presence of a circadian rhythm.

The circadian and chronological changes in inhibin secretion were studied in normal adult men. To determine the diurnal release of inhibin, blood samples were collected every hour for 24 h from five healthy young adult men, and serum inhibin was measured by RIA. During the evening and the night, serum inhibin concentrations were relatively low; the lowest value was observed at 2200 h. At 0700 h, inhibin started to increase, reached a peak at 0900 h, and then gradually decreased. These results suggest that inhibin secretion is circadian. Testosterone and cortisol also showed circadian rhythms. In some of the five volunteers, the serum concentrations of inhibin, testosterone, and cortisol were superimposable, but no significant relationship was observed between the serum inhibin and FSH concentrations. With regard to the age-related changes in basal inhibin levels, the highest values were observed in the twenties, and lower values were found with aging. This relationship suggests that increased FSH in elderly men might be due to the reduced amount of peripheral inhibin.

Adult↗
PubMed1991

[Tumor hemodynamics in hepatic nodules associated with liver cirrhosis: relationship between cancer progression and tumor hemodynamic change].

Tumor hemodynamics including arterial vascularity (AV) and portal perfusion (PP) were evaluated in histologically confirmed 55 hepatic nodules associated with cirrhosis using ultrasonographic (US) angiography during intraarterial carbon dioxide microbubbles injection and CT during arterial portography. Tumor hemodynamic patterns were classified into 6 types as follows: Type I (n = 10): PP (+), AV (hypo); Type I' (n = 2): PP (+), AV (iso); Type II (n = 5): PP (-), AV (hypo); Type III (n = 8): PP (-), AV (iso); Type IV (n = 25): PP (-), AV (hyper), Type V (n = 5): PP (partially +), AV (vascular spot in hypovascular). Eight nodules of Type I were diagnosed as benign nodules histologically including adenomatous hyperplasia (AH) (n = 6) and regenerative nodule (n = 2). Hundred percent (5/5) of Type II and 88% (7/8) of Type III nodules were well-differentiated HCC, in contrast to 8% (2/25) of Type IV nodules, typical HCCs. Fatty metamorphosis was observed in 75% (6/8) of Type III nodules, in contrast to 16% (4/25) of typical (classical) HCC nodules (Type IV). We concluded that at the malignant transformation from AH to HCC, reduction of portal blood flow in the nodule precedes the initiation of the increase of the arterial tumor vessel. Moreover, early stage HCC could exhibit hypovascular (Type I, II), isovascular (Type III), or vascular spot in hypovascular pattern (Type V) compared with a typical HCC (Type IV). It was also suggested that the more mature as a neoplasms the HCC becomes, the more the arterial tumor vessel in the nodule increases and fatty metamorphosis of well-differentiated HCC is highly related with tumor hemodynamic condition, i.e., hypoperfusion state from both arterial and portal vessel.

Carcinoma, Hepatocellular↗
PubMed1991

The role of endogenous gonadotropin release in the etiology of ovarian enlargement during purified urinary follicle-stimulating hormone therapy.

Patients with polycystic ovarian disease were grouped into three groups according to their maximum ovarian diameter (maxD) after ovulation induction by purified urinary follicle-stimulating hormone (FSH). Serum luteinizing hormone (LH) and FSH were measured daily by radioimmunoassay and size and number of follicles were assessed by ultrasonography. Follicle-stimulating hormone in group A (80 mm less than or equal to maxD) was significantly higher than those of group B (60 mm less than or equal to maxD less than 80 mm) and C (maxD less than 60 mm) for the last 4 days of the treatment. This FSH rise in group A was not accounted for by FSH accumulation by the study of pharmacodynamics, and so was thought to be of endogenous origin. Luteinizing hormone was also elevated 3 days before the administration of human chorionic gonadotropin (hCG) in both groups A and B. The number of follicles in group A at hCG administration was significantly greater than that of group C. Any significant differences were not found in either total amount of purified urinary FSH or in the basal FSH and the LH levels before treatment of the three groups. These results suggest that excessive ovarian enlargement during gonadotropin therapy is caused by multiple follicular development primarily stimulated by endogenous FSH. Endogenous LH release further enhances ovarian enlargement.

Chorionic Gonadotropin↗
PubMed1991

[Incidence of Chlamydia trachomatis isolated from endocervical columnar cells of the uterine cervix].

To study the incidence of Chlamydia trachomatis (C.T.) infection among women, we obtained swab (endocervical columnar cells) from the uterine cervix of 1,041 women attending the Department of Obstetrics and Gynecology of Gunma University Hospital. The results were as follows. 1) Overall, C.T. was isolated from 60 of the 1,041 women (5.8%). With reference to the diagnoses, the organism was isolated from 38 of 183 patients with cervicitis (20.8%) and from 22 of 858 asymptomatic womens (2.6%) (p less than 0.001). 2) C.T. antigen was detected at a higher frequency (15.0%) in the under 30 years age group than in the over 30 year age group (2.3%) (p less than 0.001). 3) The unstained inclusion C.T. bodies were confirmed more easily by phase contrast microscopy. 4) Inclusion bodies were specified as either reticulate or elementary bodies by the acridine orange staining method.

Adult↗
PubMed1990

Cloning and sequencing of human LH/hCG receptor cDNA.

We have isolated and sequenced a cDNA encoding the human luteinizing hormone--choriogonadotropin (LH/hCG) receptor. The deduced amino acid sequence (699 residues) containing seven putative transmembrane segments displays sequence similarity to G protein-coupled receptors. The receptor consists of 335 residue extracellular domain which contains six N-linked glycosylation sites. While the protein is 85 and 87% identical overall with the previously cloned rat and porcine LH/hCG receptor respectively, the most highly conserved regions are the putative transmembrane segments (91 and 94% similarity, respectively).

Amino Acid Sequence↗
PubMed1990

Regulation of LH/hCG receptor by gonadotropins in rat ovary.

To investigate the regulation of the LH/hCG receptor gene by gonadotropins, we examined the effect of PMSG and hCG on the expression of LH/hCG receptor in immature rat ovary. Northern blot analysis of ovarian RNA revealed a major mRNA of 5400 nucleotides and minor species of 7500, 3600, 2300, and 1200 nucleotides, and PMSG treatment slightly increased the intensity of all LH/hCG receptor messengers. Subsequently, hCG treatment decreased the number of LH/hCG receptor by day 2 and mRNA levels by 12h after injection. The level of mRNA recovered and increased 5-fold of control by day 6, then returned to control levels by day 10, followed by slower decline in LH/hCG receptor in plasma membrane. These studies demonstrate that the effects of PMSG and hCG on the number of LH/hCG receptor are closely related to the actions of these hormones on LH/hCG receptor messenger levels.

Aging↗
PubMed1990

Clinical pharmacodynamics of urinary follicle-stimulating hormone and its application for pharmacokinetic simulation program.

To clarify the pharmacodynamics of urinary gonadotropins, same doses of Metrodin (Serono Laboratories, Aubonne, Switzerland) or Pergonal (Serono, Rome, Italy) were injected intramuscularly into normal adult men in a crossover manner, and serum follicle-stimulating hormone (FSH) and luteinizing hormone were measured by radioimmunoassay. Follicle-stimulating hormone bioavailability parameters of Metrodin (150 IU), such as peak concentration (cmax), the time when cmax is observed, half-life, and area under concentration, were 8.9 +/- 2.5 mIU/mL, 7.7 +/- 2.1 hours, 36.0 +/- 16.4 hours, and 258.6 +/- 47.9 mIU/mL X hour, respectively, and were not statistically different from those of Pergonal. On the other hand, by daily administration of Metrodin into women with isolated gonadotropin deficiency, serum FSH levels were elevated gradually, reached peak levels within 4 days, and maintained the same levels until the doses were increased. This pattern of FSH accumulation was parallel with the simulation pattern calculated using bioavailability parameters obtained from normal men, suggesting that exogenously administered FSH distributes into peripheral circulation in the manner of a one compartment model.

Adult↗
PubMed1990

A highly sensitive and specific sandwich enzyme immunoassay for detection of human chorionic gonadotropin in trophoblastic disease.

A highly sensitive and specific two-site enzyme immunoassay (EIA) kit for human chorionic gonadotropin (hCG) has been examined and applied to the detection of hormones in the serum of normal individuals and patients with trophoblastic disease. This EIA uses a solid phase coupled antibody to the unique COOH terminal peptide region of the hCG beta-subunit (beta-CTP) and an enzyme conjugated monoclonal antibody to the hCG beta-subunit. The overnight 2 step assay measured as little as 0.2 mIU/ml serum without hLH interference and a rapid one step assay was newly developed in our laboratory. Assays of serum from normal men and nonpregnant women of reproductive age indicated that most individuals did not have detectable serum levels of hCG immunoreactivity, although a minority had minute amounts. In contrast, women with non-functional ovaries had detectable levels of hCG immunoreactivity with a mean value of 0.86 mIU/ml serum. The extremely high sensitivity and specificity of the EIA in detecting hCG provides substantial advantages for the detection of early pregnancy and for monitoring trophoblastic tumors.

Chorionic Gonadotropin↗
PubMed1990

High concentrations of plasma immunoreactive inhibin during normal pregnancy in women.

The plasma inhibin concentrations in 190 normal pregnant women at 5-40 weeks gestation and in 4 puerperal women were measured by a specific RIA for human inhibin. The average plasma inhibin concentrations in pregnant women throughout pregnancy (minimum, 2.25 +/- 0.48 IU/mL at 17 weeks gestation; maximum, 24.15 +/- 6.99 IU/mL at 39 weeks gestation) were much higher than those in nonpregnant women with a normal menstrual cycle (0.46 +/- 0.04 IU/mL in the midfollicular phase and 2.02 +/- 0.47 IU/mL in the midluteal phase). The inhibin concentrations were already high at 5 weeks gestation (7.54 +/- 1.10 IU/mL) and rose to peak at 8-10 weeks gestation. The concentrations then decreased and remained relatively low during 14-30 weeks gestation, but rose again during the third trimester. The inhibin concentrations decreased to undetectable levels after delivery. Immunoreactive inhibin was demonstrated in the corpus luteum and term placental extracts, and the dose-response curves were parallel to an inhibin preparation from human follicular fluid. Immunoreactive inhibin concentrations were also high in both the umbilical vein and artery (7.77 +/- 0.80 and 7.84 +/- 0.78 IU/mL, respectively). These observations suggest that both the corpus luteum and placenta are likely sources of inhibin.

Adult↗
PubMed1990

[Pulsatile LH secretion and hypothalamic-pituitary function in amenorrheic women].

In order to evaluate hypothalamic-pituitary function and pulsatile LH secretion in 42 amenorrheic women, blood was collected every 20 min. for 6 hrs. The mean LH pulse frequency (LH-pf) of women with a normal cycle, PCO and hyperprolactinemia was 3.4 +/- 0.5, 5.2 +/- 0.8, and 1.6 +/- 1.0/6 hrs, respectively. Hypothalamic amenorrhea (HA) with no progesterone withdrawal bleeding showed a lower frequency of LH secretion. As LH-pf in HA with progesterone withdrawal bleeding (HAI) ranged from 0 to 5/6 hrs, the HAI group was divided into 2 groups according to whether their LH-pf was less than 3.4/6 hrs (HAIa) or more (HAIb). Pituitary response to 100 micrograms of LH-RH in HAIb was much lower than in HAIa and PCO. On the other hand, in HA with LH-pf less than 3.4, LH-pf showed a significant correlation with basal LH and FSH levels and the LH increase to 100 micrograms of LH-RH, while in HA with LH-pf greater than or equal to 3.4, LH-pf had no significant correlation with them. In PCO, a high LH pulse frequency and amplitude and LH response to 100 micrograms of LH-RH were shown, but the LH increase to 100 micrograms of LH-RH was significantly reduced with the increase in LH-pf. Pituitary response to 100 micrograms of LH-RH in women with hyperprolactinemia was maintained despite low LH-pf. These results suggest that the analysis of pulsatile LH secretion is very helpful in evaluating hypothalamic-pituitary function in amenorrheic women.

Amenorrhea↗
PubMed1990

[Clinical effects of pulsatile LH-RH administration on ovulation induction for women with various type of amenorrhea].

Using pulsatile LH-RH administration, ovulation induction was performed in women with pituitary dwarfism (PD, n = 1), isolated gonadotropin deficiency (IGD, n = 5), secondary hypothalamic amenorrhea (gestagen negative (AM2, n = 10), positive (AM1, n = 5)), polycystic ovarian disease (PCO, n = 6) and anovulatory cycle (ANOV, n = 1). Five to 20 micrograms of LH-RH was administered subcutaneously with a pulse frequency of 90 min to 2 h, in 76 treatment cycles. The ovulation rate of IGD, AM2, AM1 and PCO was 54.5, 83.3, 12.5 and 50.0%, respectively, all being significantly different from each other. In some cases, ovulation induction was repeated for several cycles without any interruption, and chronic effects of this therapy on the subsequent cycle were examined. In IGD and AM2, subsequent cycles were well stimulated, while those of PCO became refractory. These results indicate that pulsatile LH-RH administration should be the first choice of ovulation induction in IGD and AM2, and less effective in AM1 and PD. When this treatment is applied for PCO, the luteal phase should be supported by alternative methods to avoid pituitary desensitization.

Amenorrhea↗
PubMed1990

[Study on the accuracy of uterine endometrial dating].

In order to examine the accuracy of endometrial dating, endometrial dating from 52 infertile women with normal luteal function was investigated. Dating from the histological findings was evaluated from three time points, the onset of the next menstrual period (NMP), the last day of the low phase of basal body temperature (BBT) and the urinary LH peak determined with the "Organon LH Color" kit (LH). Beside microscopic observation, morphometric analysis of endometrial findings was done by means of a high speed color image analysis system "Olympus SP-500". On the day of LH Color (+2), the serum LH level showed a maximum of 35.5 +/- 12.6 mIU/ml (Mean +/- S.D.) (n = 27). The correlation coefficients for histological dating and chronological dating based on NMP, BBT and LH were 0.685, 0.728 and 0.879 in gland and 0.620, 0.737 and 0.833 in stroma, respectively. The multiple correlation coefficient for histological dating evaluated by morphometric analysis and chronological dating based on LH was 0.959. So we conclude that endometrial dating evaluated by morphometric analysis seems to be the most objective and useful.

Adult↗
PubMed1989

Distinction between hemangioma of the liver and hepatocellular carcinoma: value of labeled RBC-SPECT scanning.

The role of adding single-photon emission CT (SPECT) to 99mTc-labeled RBC imaging of the liver was evaluated by specifically focusing on the differentiation between hepatic hemangioma and hepatocellular carcinoma. Planar RBC imaging followed by blood-pool SPECT scanning was performed in 77 patients with a total of 108 hemangiomas and in 29 patients with a total of 46 hepatocellular carcinomas. All lesions were smaller than 5 cm in diameter. Thirty-six (33%) of 108 hemangiomas were detected by planar delayed RBC imaging, whereas 63 (58%) were detected by the delayed RBC-SPECT scan. The smallest hemangioma shown by delayed RBC-SPECT scanning was 1.4 cm in diameter, compared with 1.7 cm by planar RBC scanning. When confined to nodules larger than 1.4 cm in diameter, 42% of hemangiomas (36/85) were detected by planar delayed RBC imaging, whereas 74% (63/85) were detected by delayed RBC-SPECT. Increase in sensitivity was noted in nodules 2.1-4.0 cm in diameter. No hepatocellular carcinomas were shown by delayed RBC planar or SPECT scans. We concluded that with the addition of SPECT, the sensitivity of delayed RBC scans in the detection of small hemangiomas is considerably improved. Delayed RBC-SPECT scanning can be used to distinguish hemangioma from hepatocellular carcinoma.

Adult↗
PubMed1989

Focal fatty infiltration of the liver in acute alcoholic liver injury: hot spots with radiocolloid SPECT scan.

We present herein a case of focal fatty infiltration of the liver, in which extremely unusual findings were exhibited on single-photon emission computed tomography (SPECT) of the radiocolloid liver scan. Liver scan was performed on a 46-yr-old patient with a clinical picture of acute alcoholic hepatitis. Multiple hot spots were demonstrated by SPECT scan, and these lesions corresponded to focal fatty infiltration, which were proven by computed tomography (CT). These hot spots disappeared rapidly in accordance with the improvement in fatty change on CT, and with the improvement in the clinical picture. The hot spots in this case were believed to represent the nonuniform intrahepatic shuntings, which presumably caused the development of focal fatty infiltration as well. SPECT may be useful in detecting and monitoring the alteration of hepatic circulation in alcoholic patients with focal fatty infiltration of the liver when planar colloid liver scan shows a mottled pattern.

Acute Disease↗
PubMed1988

[Tissue distribution of CA-125 in female reproductive organs].

In order to elucidate the origin of elevated serum CA-125 values in patients with endometriosis, CA-125 content in the uterine endometrium, myometrium, leiomyoma, fallopian tube, ovary, adenomyotic tissue and endometriotic tissue, were measured by RIA. The CA-125 content in the normal endometrium was 334.7 +/- 39.1 U/mg-protein, and this was significantly (p less than 0.001) higher than that in the myometrium (66.1 +/- 8.6), cervical gland (131.7 +/- 24.2), fallopian tube (111.6 +/- 15.8) and ovary (64.6 +/- 15.6). Endometriotic tissue contained 217.5 +/- 23.1, and adenomyotic tissue contained 235.3 +/- 47.7. No significant difference was found between tissue from cervical and corporal malignancies of the uterus, but ovarian cancer tissue contained a high CA-125 level compared to normal ovarian tissue. The mean concentration of CA-125 in menstrual blood was 377.9 +/- 79.9 U/ml and was about 11 times as high as that seen in peripheral blood in the same donor. The fact that the endometrium contained the highest amount of CA-125 among normal tissues examined supports the hypothesis that externally developed endometrium is the primary source of elevated serum CA-125 in patients with endometriosis.

Adult↗