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Biomedical subjects

R Iizuka

Publications and source records attributed to R Iizuka.

At least 145 records · Page 8Linked to original sources
PubMed1985

[The study of opioid peptides in the normal menstrual cycle, pregnancy and labor].

The present investigation was performed for the purpose of measuring serum immuno-reactive (IR)-beta-lipotropin (LPH), IR-beta-endorphin (EP) and adrenocorticotropic hormone (ACTH) in normal menstrual cycle, pregnancy and labor of normal human subjects. The normal menstrual cycle was divided to menstrual (n = 7), follicular (n = 18), ovulatory (n = 12) and luteal phases (n = 16). The serum concentration of IR-beta-EP and ACTH was significantly higher in the luteal phase than those in other phases. The values for IR-beta-LPH were also higher in luteal phase, but statistically not significant. Normal pregnancy was divided to three groups; I: first trimester (n = 12-15), II: second trimester (n = 11) and III: third trimester (n = 13-18). Normal labor (n = 7) was also divided into two stages, the period with a cervix dilatation of 5cm and 10cm dilatation. The serum concentration of IR-beta-LPH and IR-beta-EP increased progressively with gestational weeks. During labor these two peptides showed maximum values at the period with cervix dilatation of 10cm. These findings indicate that the basic values for opioid peptides in human reproductive cycle can be applied to further clinical analysis of several gynecological disorders.

Adrenocorticotropic Hormone↗
PubMed1985

[Induction of ovulation with subcutaneous pulsatile administration of human menopausal gonadotropin].

Induction of ovulation with subcutaneous pulsatile (every 90 min.) administration of HMG (Pergonal) 75 or 150 IU/day using a portable pump (Nipro SP-3I) was performed in 3 PCO patients (6 cycles), 4 first grade amenorrhea (Am-I) patients (7 cycles) and 4 Am-II patients (4 cycles). All patients ovulated except one cycle of Am-I patients and one PCO woman conceived. In regard to the duration of administration and the total dose of HMG until ovulation, the administration of 150 IU/day (M +/- SD=15.2 +/- 5.0 days, 2280 +/- 774 IU) is superior to 75 IU/day (39.5 +/- 11.4 days, 3900 +/- 1357 IU), and there was no significant difference between this method and the daily intramuscular injection of HMG. The group treated with HCG in the luteal phase revealed a longer luteal phase (14.0 +/- 2.3 days) than the nontreated group (12.6 +/- 1.5 days). Ovarian hyperstimulation was observed in one case and subsided spontaneously after admission. There were no other side effects. In conclusion, this method has the following advantages: A high ovulation rate, comparable with daily intramuscular administration. It is a less painful procedure than daily intramuscular injection. It is possible for the patient to lead normal life, insertion and removal being easily done by herself.

Adult↗
PubMed1985

[Clomiphene-HMG ovarian stimulation in human in vitro fertilization and embryo transfer].

In a program for in vitro fertilization and embryo transfer, laparoscopies for oocyte aspiration were performed in 40 cycles in 36 normally menstruating women with irreparable tubal diseases (IVF patients) who received clomiphene citrate (CC) and human menopausal gonadotropin (hMG). An intramuscular injection of human chorionic gonadotropin (hCG) was given to all patients after completion of follicular maturation. Fourteen cycles in 13 spontaneously ovulating women (control patients), also stimulated with CC and hMG, were adequately monitored to identify the appearance of the spontaneous luteinizing hormone (LH) surge. The follicular maturation was followed by daily ovarian ultrasonographic examination and serum estradiol estimations. Just before the LH surge the diameter of the leading follicle was 20.2 +/- 0.7 (mean +/- S.E.) mm and the serum estradiol concentration per follicle was 384.1 +/- 16.3pg/ml in the control patients. In the IVF patients the former was 20.6 +/- 0.3mm and the latter was 305.8 +/- 13.3pg/ml prior to hCG administration. When the relationship of follicular size to the rates of oocytes recovery, maturation, fertilization and cleavage was examined, larger follicles (3ml less than or equal to follicular fluid volume) showed good results. Of the 152 oocytes that were recovered from these IVF patients, 96 (63.2%) were fertilized and 79 (52.0%) cleaved. Three pregnancies resulted from 35 embryo transfers.

Adult↗
PubMed1984

Biological effects of trilostane in vitro on oocyte maturation and fertilization in the hamster.

The effects of the inhibition of steroidogenesis by trilostane on oocyte maturation were examined by studying spontaneous maturation and fertilization in vitro. 10(-6)M trilostane had no influence on the meiotic process, whether the oocytes were naked or not. At a concentration of 10(-6)M and 10(-7)M trilostane, low normal pronuclear formation and high polyspermy were found during in vitro fertilization. However, no retarded male pronuclear development could be detected in the trilostane-treated group. Thus, steroid producing activity within ova is apparently necessary to prevent multiple sperm penetration, but it has no effect on meiosis or the action of the so-called male pronucleus growth factor (MPGF).

3-Hydroxysteroid Dehydrogenases↗
PubMed1984

Human X- and Y-bearing sperm differ in cell surface sialic acid content.

Analysis of cell surface charge of human sperm by means of free-flow electrophoresis revealed that the electrophoretic mobility of X-bearing sperm was faster than that of Y-bearing sperm, indicating that X-bearing sperm have a higher net negative charge on the cell surface than do Y-bearing sperm. Sialidase treatment of X- and Y-bearing sperm caused an obvious and progressive reduction in the electrophoretic mobilities of the two types of cells, until they finally merged into a single peak. This observation suggests that the difference in net negative charge between X- and Y-bearing sperm is due mainly to sialic acid content on the cell surface.

Adult↗
PubMed1984

Indirect immunofluorescence studies on the steroid-producing activity of hamster ova.

Steroidogenesis in the unfertilized hamster ova was investigated by indirect immunofluorescence study. delta 5-3 beta-Hydroxysteroid dehydrogenase (delta 5-3 beta-HSD) activity was found in hamster follicular and ovulatory ova with pregnenolone used as the substrate. A significant quantity of 17 beta-estradiol was detected in the ooplasm of follicular and ovulatory ova. No progesterone was found. The activity of delta 5-3 beta-HSD in follicular and ovulatory ova was inhibited by preincubation with 10 IU of human chorionic gonadotropin (hCG) in 1 ml of phosphate buffer solution. Trilostane, a potent new inhibitor of the delta 5-3 beta-HSD system, was found to inhibit the activity of delta 5-3 beta-HSD in ovulatory ova in 1 ml of phosphate buffer solution at a concentration of 10(-7)M. After these results were obtained, steroidogenesis of hamster ova was suggested in an indirect immunofluorescence study, and the implications of steroidogenesis for oocyte maturation and subsequent fertilization are discussed.

3-Hydroxysteroid Dehydrogenases↗
PubMed1984

A preliminary study of free amino acids in the postmortem temporal cortex from Alzheimer-type dementia patients.

Concentrations of free amino acids were measured in the temporal cortex of postmortem brains from four histologically verified cases with Alzheimer-type dementia (ATD) and eight histologically normal controls. The concentrations of taurine, glutamate, and gamma-aminobutyric acid, which are all neurotransmitter candidates, were significantly lower in the ATD brains than in the controls. These findings suggest that the involvement of amino acid neurons in ATD cannot be ruled out.

Aged↗
PubMed1984

Changes of biogenic amines and their metabolites in postmortem brains from patients with Alzheimer-type dementia.

Noradrenaline (NA), 3,4-dihydroxyphenylethylamine (dopamine, DA), 5-hydroxytryptamine (serotonin, 5-HT), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were measured in 22 regions of postmortem brains from four histologically verified cases with Alzheimer-type dementia (ATD) and nine histologically normal controls. Compared with the controls, concentrations of 5-HT and 5-HIAA in the ATD brains were significantly reduced in nine regions (superior frontal gyrus, insula, cingulate gyrus, amygdala, putamen, medial and lateral segments of globus pallidus, substantia nigra, lateral nucleus of thalamus) and in eight regions (amygdala, substantia innominata, caudate, putamen, medial and lateral segments of globus pallidus, medial and lateral nuclei of thalamus), respectively. NA concentrations of the ATD brains were significantly reduced in six regions (cingulate gyrus, substantia innominata, putamen, hypothalamus, medial nucleus of thalamus, raphe area). In contrast, significant reductions of DA and HVA concentrations in the ATD brains were found only in putamen and amygdala, respectively. The 5-HIAA/5-HT ratio in the ATD brains decreased significantly in locus coeruleus, while the HVA/DA ratio increased significantly in putamen and medial segment of globus pallidus. These findings suggest that the serotonergic and noradrenergic systems are affected, while the dopaminergic system is relatively unaffected in ATD brains.

Alzheimer Disease↗
PubMed1984

Dentato-rubro-pallido-luysian atrophy: a clinico-pathological study.

Clinical and neuropathological descriptions are given of four cases of an uncommon disease, characterised by simultaneous degeneration of the dentato-rubral and pallido-luysian systems. These four are compared with sixteen previously described cases, and the group as a whole is compared and contrasted with other multisystem degenerations, such as olivo-ponto-cerebellar atrophy and Friedreich's ataxia. A pathological feature described here for the first time is degeneration of the fastigio-vestibular system. Clinically, there are three main types of the disease; (1) an ataxo-choreoathetoid type, (2) a pseudo-Huntington type, and (3) a myoclonic-epileptic type. There are familial cases of types 2 and 3. Oculomotor disturbances, associated with atrophy of the brainstem tegmentum, are observed in cases of types 1 and 3.

Adult↗
PubMed1984

Effects of angiotensins of the motility of human sperm.

The effects of angiotensins on the motility of highly washed human sperm were examined by multiple exposure photography system. The addition of low doses (0.1-10 ng/ml) of angiotensin II (AT II) stimulated the forward velocity of sperm without increasing the percentage of motility. On the contrary, high concentration (1.0 micrograms/ml) of AT II suppressed the motility. The direct effect of angiotensin I (AT I) on the motility was observed under the presence of SQ 14225, a specific inhibitor of angiotensin I converting enzyme (ACE). At I (0.1-100 ng/ml) gave no influence on the motility, whereas that of high dose (1.0 ug/ml) suppressed the motility in the same manner as the corresponding dose of AT II. The action of AT II on the motility was completely suppressed under the coexistence of saralasin, a specific antagonist against AT II. This fact indicated that the action of AT II on the sperm appeared through the specific receptor on sperm.

Angiotensin I↗
PubMed1984

Immunohistochemical study on oxytocin-like substance in the human placenta.

Our previous studies have demonstrated that a large quantity of oxytocin (OT)-like substance exists in human placental tissue. In the present study, the localization of the OT-like substance in the human placenta was investigated by the PAP (peroxidase and antiperoxidase complex) immunohistochemical method. The results demonstrated that the site of syncytiotrophoblast was positively stained by specific antiserum to OT, whereas the tissue was not significantly stained by normal rabbit serum (NRS). These results suggest that the OT-like substance might be localized in syncytiotrophoblast of the placental tissue.

Cross Reactions↗
PubMed1984

Pituitary response of growth hormone release in administration of hpGRF-44 to pregnant rats.

To investigate the pituitary response to exogenous growth hormone releasing factor (GRF) during pregnancy, pregnant (from Day 7 to Day 16) and non-pregnant rats were cannulated through a femoral vein, then hpGRF-44 (1.0 microgram) or saline was administered intravenously under anaesthesia with pentobarbital sodium. An initial blood sample was drawn off before the administration and subsequent samples were taken at 5, 10, 15 and 20 min post injection for measurement of plasma growth hormone (GH) values by radioimmunoassay. In a group of pregnant rats (n = 9), a mean concentration of plasma GH was increased to a peak in 10 min, from 132.5 +/- 14.9 ng/ml (mean +/- S.E.) to 864.4 +/- 175.1 ng/ml after hpGRF-44 administration. The mean value for non-pregnant rats (n = 6) reached a peak in 5 min from 164.5 +/- 34.1 ng/ml to 921.2 +/- 257.2 ng/ml. The injection of saline produced no changes in plasma GH concentrations in pregnant (n = 4) or non-pregnant (n = 3) rats. Moreover no significant difference in plasma GH responses to hpGRF-44 was found between early (from Day 7 to Day 8, n = 5) and late (from Day 15 to Day 16, n = 4) pregnant rats. The data indicate that the plasma GH levels following the administration of hpGRF-44 were not different between pregnant and non-pregnant rats, though the pregnant pituitary responses to hpGRF-44 were delayed a little longer than those of the non-pregnant pituitary.

Animals↗
PubMed1984

Catecholamine-related enzymes and the biopterin cofactor in Parkinson's disease and related extrapyramidal diseases.

In parkinsonian brain, TH and the BP cofactor, as well as DBH and PNMT with phenylethanolamine as substrate, are decreased. However, decrease in AADC with L-DOPA as substrate was not statistically significant. TH activity has also been shown to be decreased in striatonigral degeneration and Shy-Drager syndrome. TH reduction only in striatum but not in substantia nigra was found in a case of juvenile Parkinson's disease. Changes in AADC with L-DOPA or L-5-HTP as substrates varied in parkinsonian brains. PNMT with norepinephrine as substrate was also significantly decreased in parkinsonian brains. After administration of tyrosine to mice, the BP concentration was increased in striatum, adrenals, and serum. Mean BP concentration in serum of parkinsonian patients was slightly but significantly lower than that in controls. The serum BP increased three- to sevenfold in response to an oral tyrosine load in controls, whereas there was no increase or only a minor one (less than threefold) in parkinsonian patients. Our present results indicate that all catecholamine-synthesizing enzymes and BP synthesis may be impaired in Parkinson's disease.

Adult↗
PubMed1984

The effects of neuroleptics (haloperidol and chlorpromazine) on the pharmacokinetics of valproic acid in schizophrenic patients.

The steady state trough concentrations (Cmin) and pharmacokinetics of valproic acid were investigated in schizophrenic patients during the treatment of valproic acid, 200 mg, twice daily and after the one dose of 400 mg, respectively, with and without haloperidol (6 to 10 mg/day, N = 6) or chlorpromazine (100 to 300 mg/day, N = 6). Four to 5 Cmin were monitored just before the morning valproic acid dose for 3 to 4 days preceding the kinetic study. The overall Cmin of valproic acid with chlorpromazine (33.2 +/- 1.7 micrograms/ml, N = 25) was significantly (p less than 0.01) greater than without (27.1 +/- 1.4 micrograms/ml, N = 25). The majority of the mean valproic acid concentrations observed after the 400-mg dose were significantly (p less than 0.05 to 0.01) greater during the chlorpromazine treatment as compared to those without the phenothiazine. The mean t1/2 was shortened from 15.4 +/- 1.4 to 13.5 +/- 1.2 hours (p less than 0.05) with a comparable increase in the clearance from 7.18 +/- 0.38 to 8.32 +/- 0.34 ml/hour/kg (p less than 0.01) after the discontinuation of chlorpromazine. All the patients revealed an increase in the valproic acid clearance after the chlorpromazine therapy was discontinued. When viewed overall, such a trend as found in the chlorpromazine group was not observed in the haloperidol group. The results suggest that chlorpromazine, but not haloperidol, inhibits the metabolism of valproic acid. However, the clinical significance of the interaction awaits future study.

Adult↗