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H Okada

Publications and source records attributed to H Okada.

At least 1,099 records · Page 61Linked to original sources
PubMed1984

[Aromatization of C-19 steroid in human fetal liver tissue].

In this study we examined whether or not human fetal liver has the ability to aromatize various C-19 steroids to estrone, estradiol and estriol. The human fetal liver homogenate (1g in 10ml of 0.1 M-phosphate buffer) was incubated with the labelled C-19 steroids ([7-3H]-DHEA,-DHEAS, -A:10 microCi, [4-14C]-A:3 microCi) and NADPH at 37 degrees C for 2h in air. [14C]-E1,-E2,-E3 or [3H]-E1,-E2,-E3 (1 x 10(4)dpm, 250 micrograms) were added as tracers after the addition of 3 volumes of ethanol, respectively. E1,E2 and E3 produced were decided by submission to extraction with ethyl acetate, Bio-Rad AG1-X2 resin column chromatography, thin layer chromatography and then co-crystallization to constant specific activity and the 3H/14C ratio. The yield of isolated E1,E2 and E3 were calculated from the 3H/14C ratio of the final crystal. Consequently, DHEA was transformed to 0.78 pmol E1/h/g, 0.14 pmol E2/h/g and 0.18 pmol E3/h/g in human fetal liver, respectively. E1,E2 and E3 were converted from DHEAS to 0.04 pmol/h/g, under 1 fmol/h/g and 0.04 pmol/h/g, respectively. A was transformed to 17.5 pmol E1/h/g, 26.6 pmol E2/h/g and under 1 fmol E3/h/g, respectively. These results indicate that human fetal liver is able to aromatize C-19 steroid to estrogens.

Androstenedione↗
PubMed1984

Implications of subcellular steroid binding sites in endometrial cancer, determined by an immunofluorescent steroid-antibody technique and biochemical assay.

A discrepancy has been found between the progestogen level necessary for treatment of endometrial cancer and the steroid receptor level detected for the response indicator. Therefore the relationships between the steroid binding quantity detected biochemically and the steroid reactivity determined immunofluorescently was evaluated subcellularly in the endometrial cancers. Estradiol-17 beta and progesterone fluorescences were not always related to the classical steroid receptor binding quantities. These two steroids bound to the nuclear components directly, but heterogeneously. In the biochemical method using fractionated dispersed cancer cells, cellular heterogeneity of the steroid receptor mechanism in a given endometrial cancer tissue was proved. Steroid fluorescence was not related to the steroid-receptor complex quantity in the normal endometrial nucleus. This suggests that the binding of steroid antibody to the steroid-receptor bound already to the nucleus seems to be inhibited due to steric hindrance. Therefore the nuclear steroid fluorescence did not always give the nuclear steroid-receptor complex quantity. These results indicate heterogeneity in the estrogen and progestogen receptor mechanism in endometrial cancer, when studied by the biochemical and immunofluorescent techniques, and that these steroids bind to the nucleus directly and may influence the nuclear mechanism. Therefore, in endometrial cancer progestogen does not always have a therapeutic effect through the progestogen receptor and does not affect the therapeutic effect on any of the cells.

Aged↗
PubMed1984

[Fundamental and clinical studies on ceftazidime in the field of obstetrics and gynecology].

Fundamental and clinical studies were performed on ceftazidime ( CAZ ), a new cephem antibiotic. Following a single intravenous administration of 1 g dose of CAZ , the transfer of CAZ to the internal genital organs was good. The transfer of CAZ to retroperitoneal fluid was excellent. In a clinical trial, CAZ was given to 6 patients with obstetrical and gynecological infections. The efficacy was evaluated as excellent in 3 cases and good in the other 3 cases. No adverse effects were observed in any of the patients treated with CAZ .

Adult↗
PubMed1984

Lysis of horse red blood cells mediated by antibody-independent activation of the alternative pathway of chicken complement.

Horse red blood cells (HRBC) were found to be lysed when incubated with fresh normal chicken serum (NCS). By comparison of the properties of the lysis of HRBC with those of the complement-dependent lysis of sheep red blood cells (SRBC) sensitized with haemolytic antibody via the classical pathway, the following differences were observed between the two haemolytic phenomena. (i) The lysis of HRBC was independent on antibody in contrast to the antibody dependence of the lysis of sensitized SRBC. (ii) The lysis of HRBC was dependent on Mg but not on Ca ion, whereas the lysis of sensitized SRBC required both Mg and Ca ions. (iii) Treatment of NCS with carrageenan that acts as an inactivator of the first component of complement (C1) inhibited the lysis of sensitized SRBC but not the lysis of HRBC. (iv) C1 was consumed in the lysis of sensitized SRBC but not in the lysis of HRBC. (v) Cobra venom factor (CVF), C3 inactivator via the alternative complement pathway, inhibited the lysis of HRBC but not the lysis of sensitized SRBC. (vi) Minimal reaction times for the lysis of HRBC and for the lysis of sensitized SRBC were 90 and 60 min, respectively. These findings indicate that the lysis of HRBC was caused by the antibody-independent activation of complement via the alternative pathway.

Animals↗
PubMed1984

[Estrogen biosynthesis in human uterine myoma tissue. The distribution of androstenedione aromatase activity in uterine myoma tissue].

Although it is well known that the development of uterine myoma is influenced by estrogen, the details of its remain unknown. In this study, estrogen biosynthesis (androstenedione aromatase activity) was investigated in the myoma tissue (the central, surface and middle parts of the tumor) and in the myometrial tissue of the same uterus (5 cases). The tissue homogenate (500 mg w. w.) was incubated with [6,7-3H]-androstenedione (100pmol) and NADPH (1.5mg) at 37 degrees C for 1h in air. After stopping the enzyme reaction with ethyl acetate, [4-14C]-estrone and [4-14C]-estradiol-17 beta (10,000dpm, 250 micrograms, respectively) were added to the incubated sample. The sample extracted with ethyl acetate was subjected to Bio-Rad AG1-X2 column, thin layer chromatography and co-crystallization to constant specific activity and 3H/14C ratio. Estrogen formed in the incubated sample was calculated from the 3H/14C ratio of the final crystal. The myoma tissues (14 samples) converted from androstenedione to estrone (36-466 fmol/h/g), while the myometrial tissues of the same uterus did to a lesser extent (22-78 fmol/h/g), while the myometrial tissues of the same uterus did to a lesser extent (22-78 fmol/h/g). Thus, aromatase activity was significantly higher in the myoma tissue rather than in the myometrial tissue of the same uterus. Less estradiol was formed than estrone in both tissues. The distribution of aromatase activity in the tumor was also investigated, and it was found that the enzyme activity tends to become greater away from the center and towards the surface of the tumor. These results suggest that aromatase activity for androgen contributes to the development of uterine myoma.

Adult↗
PubMed1984

[A study on Ureaplasma urealyticum and sperm. Comparison of sperm morphology before and after chemotherapy].

Spermiogram (morphology of sperm heads and tails) was evaluated in 21 men visiting our infertility clinic before and after the eradication of genital infection with Ureaplasma urealyticum. The percentage of coiled tails and fuzzy granular tails were decreased after eradication of Ureaplasma but there were no significant changes in the morphologic characteristics of sperm heads. Spermiogram was also analysed in 5 men who were unsuccessfully treated for genital Ureaplasma infection. In this group there were no significant changes in the morphologic characteristics of sperm heads and tails before and after chemotherapy.

Humans↗
PubMed1984

[Fundamental and clinical studies on cefpiramide in the field of obstetrics and gynecology].

Fundamental and clinical studies were performed on cefpiramide (CPM), a new cephem antibiotic, with following results. Following a single intravenous administration of 1.0 g dose of CPM, the average serum level of CPM was 129.5 micrograms/ml after 1 hour and the half-life in beta-phase was about 5.0 hours. The transfer of CPM to the internal genital organs was found to be good. the transfer of CPM to retroperitoneal fluid was moderate. In clinical trial, CPM was given to 9 patients with obstetrical and gynecological infection. Efficacy was excellent in 1 case and good in 6 cases (effectiveness rate: 77.8%). No side effects were observed. In laboratory findings, a mild elevation of S-GOT was noted in 1 case.

Adult↗
PubMed1984

[Sequential changes of vascular intimal ultrastructure in experimental cerebral vasospasm induced by oxyhemoglobin. Scanning electron microscopic study].

Organic changes of vessel wall may play an important role in the pathophysiology of vasospasm after subarachnoid hemorrhage. Sequential changes of intimal ultrastructure in experimental vasospasm induced oxyhemoglobin were investigated by scanning electron microscope. Thirty-four cats were used for this study. The basilar artery was exposed by transcervico-transclival approach. Oxyhemoglobin solution was applied under the arachnoid membrane around the artery in 16 cats at hourly intervals. Of 16 cats, 3 were sacrificed at 1 hour after the first application of the solution, 3 at 3 hours, 3 at 6 hours, 3 at 12 hours, 4 at 24 hours. Three sham-operated cats treated by artificial CSF were used as the control together with 5 untreated normal cats. All procedures were performed under aseptic condition. Perfusion fixation was done. The luminal surface and the cut surface made by freeze-fracture method were investigated by scanning electron microscope. As oxyhemoglobin solution, oxyhemoglobin-rich hemolysate was used and the concentration was 5.5 mM. By hourly application, continuous vasoconstriction of about 70% of the control diameter was obtained. In the control, the endothelial cell layer was flat. The elastic lamina had mild waving, and the luminal surface was smooth. In 1- and 3-hour groups, the elastic lamina was corrugated and the endothelial cells were protruded into the lumen in the depressed portion of corrugation. In 6- and 12-hour groups, degenerative changes of the endothelial cells, crater-formation and ballooning, were seen. Some blood-born cells adhered to the luminal surface in such cases. In 24-hour group, the changes of the endothelial cells became more remarkable.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Estradiol-17 beta and estradiol-17-glucosiduronate before and at delivery.

The maternal peripheral serum level of estradiol-17 beta (E2), which reaches a peak a few weeks before delivery, may play a role in initiating delivery. In this study, the steroidal activity regulated by both the production and conjugation was estimated by measuring estradiol-17-glucosiduronate (E2-17-G), E2, estriol-16-glucosiduronate (E3-16-G), and estriol (E3) before and at delivery. At delivery, levels of E2 and E2-17-G were higher in the maternal peripheral vein (MP) than in the umbilical vein (UV) and umbilical artery (UA), but those of E3 and E3-16-G were higher in UV and UA than in MP. These results suggested that the production and conjugation of E2 were mainly regulated on the maternal side, but those of E3 were regulated mainly in the feto-placental unit. The ratios of E2/E2-17-G in MP were or became high a few weeks before delivery but decreased remarkably as pregnancy progressed to delivery. The activity of E2 seems to be regulated at least in part by conjugation in late pregnancy and at delivery.

Cross Reactions↗
PubMed1984

[Estrogen biosynthesis in human female adipose tissue in vitro].

The level of androstenedione aromatase activity in 10 cases of abdominal adipose tissues of premenopausal patients with benign gynecological disease (myoma uteri 7 cases, ovarian cyst 1 case, intersex 1 case, and hydatidiform mole 1 case) was examined. The adipose tissue homogenate (500mg) was incubated with [1,2,6, 7-3H]-androstenedione (10 microCi, 110 pmol), and NADPH (0.5mg) at 37 degrees C for 2h in air. After stopping the enzyme reaction, [14C]-estrone, estradiol (1 X 10(4) dpm) and cold estrone, estradiol (250 micrograms) were added as tracers. Ethyl acetate extract was submitted to Bio-Rad AG1-X2 column chromatography, TLC, and co-crystallization to constant specific activity and 3H/14C ratio. Estrone was formed in all samples (29-65 fmol/g/h), and estradiol was formed in 7 samples. The estradiol level was extremely low compared to estrone. Control samples (no tissue blank and zero time incubated samples) were under 1 fmol/g/h for estrone and estradiol through this procedure, respectively. This result indicates that adipose tissue may contribute to estrogen formation as one of the extragonadal tissues. The enzyme activity did not differ significantly according to gynecological disease, age, and superficial area.

Adipose Tissue↗
PubMed1983

Steady-state kinetics of coupled two-enzyme reactor with recycling of poly(ethylene glycol)-bound NAD.

The kinetic properties of a continuous enzyme reactor containing rabbit muscle lactate dehydrogenase, horse liver alcohol dehydrogenase and poly(ethylene glycol)-bound NAD (PEG-NAD) were investigated experimentally and theoretically. The enzymes and PEG-NAD were retained in the reactor with an ultrafiltration membrane, and the substrates (pyruvate and ethanol) were fed continuously. The reactions of the dehydrogenases were coupled by the recycling of the cofactor. The steady-state concentration of L-lactate, one of the products, was measured under different experimental conditions and compared with the corresponding theoretical value. The theoretical value was calculated based on a simplified ordered bi-bi mechanism for the individual enzyme reactions, of which kinetic constants were determined by independent kinetic studies. Differences were found between the kinetic constants of the enzymes for NAD(H) and PEG-NAD(H). The steady-state values obtained by continuous operation were lower than those calculated, possibly due to the simplification made for the kinetic model; but there was general agreement between them in the dependence on the experimental conditions. The steady-state behavior of the enzyme reactor was explained semi-quantitatively by the simple kinetic model.

Alcohol Dehydrogenase↗
PubMed1983

Prevention of complement activation on the homologous cell membrane of nucleated cells as well as erythrocytes.

A C3b receptor, a glycoprotein with a molecular weight of 205 kDa (gp205) on human erythrocytes (Ehu), has been claimed to restrict the activation of human complement via the alternative complement pathway (ACP), thereby inhibiting the activation of the ACP even on neuraminidase (Nase)-treated Ehu. However, the Nase-treated Ehu were sensitive to hemolysis by guinea pig complement via ACP activation, although the C3b receptors on Ehu can react with guinea pig C3b. Furthermore, HeLa cells which had no detectable C3b receptor did not became reactive with guinea pig ACP. On the contrary, Nase treatment of guinea pig erythrocytes (Egp) as well as guinea pig line 10 tumor cells, which have no detectable C3b receptor, could not make those cells reactive with the homologous guinea pig ACP although they became reactive with human and rabbit ACP. Similarly, rabbit E did not become reactive with the homologous rabbit ACP following Nase treatment. Nase-treated Egp preincubated with human serum in the presence of EDTA were also not lysed by guinea pig serum. Therefore the unreactiveness of Nase-treated cell membrane with homologous ACP was not merely due to the absence of antibody to cell membrane in the homologous serum. There may be a membrane inhibitor which preferentially interacts with homologous complement to circumvent undesirable complement activation on the homologous cell membrane.

Animals↗