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Biomedical subjects

H Honjo

Publications and source records attributed to H Honjo.

At least 145 records · Page 8Linked to original sources
PubMed1987

Suicide inactivation of androstenedione aromatase in human placenta by fluoroethindrone (10 beta-fluoro-17 alpha-ethynyl-19-nortestosterone).

The inhibitory effects of androstenedione aromatase activity in human placenta using fluoroethindrone (10 beta-fluoro-17 alpha-ethynyl-19-nortestosterone), which is a derivative of norethindrone (17 alpha-ethynyl-19-nortestosterone, ENT) and, unlike ENT, is considered to be refractory to aromatization, was investigated in this study. When fluoroethindrone was added to the placental microsomes in the presence of NADPH, androstenedione aromatase activity in the placental microsomes was decreased time dependently and dose-dependently by fluoroethindrone compared with the samples without NADPH. This finding suggests that fluoroethindrone acts as a suicide substrate for androstenedione aromatase in human placenta.

Aromatase Inhibitors↗
PubMed1986

Aromatization of norethindrone to ethynylestradiol in human adult liver.

Homogenates of human adult liver are capable of aromatizing norethindrone (17 alpha-ethynyl-19-nortestosterone) to ethynylestradiol (17 alpha-ethynylestradiol). The evidence of ethynylestradiol formation was obtained using a Bio-Rad AG1-X2 column, thin layer chromatographies and co-crystallization. Neither acid nor base was used in any step in product identification.

Adult↗
PubMed1986

Serum and urinary oestrone sulphate in pregnancy and delivery measured by a direct radioimmunoassay.

Serum and urinary levels of oestrone sulphate in pregnancy and delivery were measured by a direct radioimmunoassay without hydrolysis. The serum and urinary oestrone sulphate increased as pregnancy progressed. The mean level of serum oestrone sulphate increased to the highest peak of 494 pmol/ml at the 35th gestational week and then decreased. The mean level of urinary oestrone sulphate increased to the highest peak of 1.28 mumol/l at the 34th gestational week and then decreased. At vaginal deliveries, the mean level of maternal peripheral serum oestrone sulphate increased hourly at as high a level as 979 pmol/ml. The mean serum level of oestrone sulphate was 204 pmol/ml in the umbilical artery and 145 pmol/ml in the umbilical vein. At Caesarean section, on the other hand, the maternal peripheral serum level of oestrone sulphate averaged 362 pmol/ml. The mean serum levels of oestrone sulphate were 90.7 pmol/ml and 171 pmol/ml in the umbilical artery and umbilical vein, respectively. These results suggest a maternal origin of oestrone sulphate in pregnancy, with fluctuations in the levels being of interest in relation to labour pain.

Cesarean Section↗
PubMed1986

Normal development of the middle ear in the mouse: a light microscopic study of serial sections.

Development of the ear, especially the middle ear, was studied histologically in ddN and CF mice. Primordia of the 3 ossicles and the otic capsule appeared on day 12 of pregnancy. The stapedial primordium was observed as a mass of mesenchymal cells lateral to the primordium of the otic capsule, attaching to the medial part of the facial nerve. On day 13, the stapedial primordium continued to develop with the Reichert's cartilage. On day 14, the malleus and incus were differentiated. On day 15, the 3 ossicles were mostly completed in shape, and the stapedial footplate had a bilaminar structure at this stage. This structure appeared to correspond to the lamina stapedialis in the developing human stapes.

Animals↗
PubMed1984

Uptake of estrone and estrone-3-sulfate by lung of macaca fuscata.

An equimolar mixture of 3H-E1-S2 and 14C-E1 was injected in one shot into the inferior vena cava near the heart of female Japanese monkey. Following the injection, blood was collected from the aortic arch at intervals of 15 s over a period of 10 min. The concentration of radioactivities in the whole blood and serum was measured. The metabolites were analyzed by DEAE-Sephadex A-25 column chromatography, enzyme hydrolysis, thin layer chromatography and paper chromatography. Both radioactivities of 3H-E1-S and 14C-E1 rapidly decreased in the first 90-s serum sample. The 3H/14C ratio in the 0-15-s serum sample was 5 times higher than the initial ratio of injected compounds. The radioactivities in the serum gradually decreased after 90 s of injection. The 3H/14C ratio in the pulmonary tissue was very low after collecting the final blood sample. This result shows that the most of 3H-E1-S passed through the lung and the larger part of 14C-E1 remained in the lung following injection of these materials. So, it is probable that E1-S is in a form to be carried in the general circulation.

Animals↗
PubMed1984

Metabolism of lynestrenol: characterization of 3-hydroxylation using rabbit liver microsomes in vitro.

In spite of the absence of oxygen at C-3, lynestrenol (17 alpha-ethynyl-4-estren-17 beta-ol) has a marked progestational activity. It is known to be metabolized to norethindrone (17 alpha-ethynyl-4-estren-17 beta-ol-3-one) by 3 beta-hydroxylation and dehydrogenation. In the present study this conversion of lynesterol to norethindrone, via the formation of 3 alpha-hydroxylynestrenol, was investigated using rabbit liver microsomes in vitro. Two hydroxylated metabolites, 3 alpha-hydroxy-lynestrenol and 3 beta-hydroxy-lynestrenol were separated and identified by GLC and GC-MS analyses. In the course of incubation, the concentration of 3 alpha-hydroxy-lynestrenol was much higher than that of the 3 beta-hydroxy isomer suggesting that the metabolic pathway in the conversion to norethindrone proceeds predominantly via 3 alpha-hydroxylation of lynestrenol.

Animals↗
PubMed1984

Estrogen biosynthesis in human liver--a comparison of aromatase activity for C-19 steroids in fetal liver, adult liver and hepatoma tissues of human subjects.

After incubation of various tritiated C-19 steroids (androstenedione, testosterone, dehydroepiandrosterone, dehydroepiandrosterone sulfate) with human fetal liver, adult liver and hepatoma tissue homogenates, estrone, estradiol and estriol were analysed after a series of purification steps involving column chromatography, thin layer chromatography and co-crystallization. The findings indicated that the human fetal liver extensively aromatized various C-19 steroids to estrogens, whereas human adult liver and hepatoma tissues exhibited little or no aromatase activities. The formation of estradiol from androstenedione in human fetal liver indicated the presence of 17 beta-hydroxysteroid dehydrogenase in this tissue. It was therefore concluded that although the liver participated in the aromatization process during the fetal stage, extensive aromatization did not take place in the adult liver.

Aged↗
PubMed1984

Conjugated oestrogen during the menstrual cycle measured by a direct radioimmunoassay with an antiserum prepared against oestradiol-17-glucosiduronate-[C-6]-BSA conjugate.

Early morning and 24 h urine samples and serum were collected daily throughout the menstrual cycle in women. Urinary oestradiol-17-glucosiduronate (E2-17-G) was measured with a direct radioimmunoassay whose antiserum had been prepared against E2-17-G-[C-6]-bovine serum albumin conjugate and was very specific. On the average, E2-17-G in early morning and 24 h urine samples showed a prominent peak one day before the peak of urinary LH. The time relationship between these urinary E2-17-G and serum E2 levels and peaks was also investigated.

Adult↗
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↗
PubMed1983

[Evaluation of cefotetan in obstetrics and gynecology].

Fundamental and clinical studies on gynecological use of cefotetan (CTT), a new cephamycin antibiotic, were performed with following results. Following the intravenous administration of 2.0 g of CTT, T 1/2 beta in serum was 3.1 hours and longer than the previous cephamycin antibiotics. The yields of CTT from serum to various uterine tissues and discharge from retroperitoneum were about 30 approximately 50%. In clinical use, 14 patients with gynecological infections were administrated CTT, and it showed excellent or good efficacy in all patients. No side effects were noted except 1 transient disturbance in liver function.

Adult↗
PubMed1982

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

We conducted a study on the utility in the obstetric and gynecological field of piperacillin (PIPC) which is a broad spectrum penicillin developed here in Japan. After administration of PIPC by intravenous one shot injection or intravenous dripping infusion the yield of PIPC to the various uterine tissues was a favorable 30 approximately 40% in comparison with the serum concentration and the discharge from retroperitoneum was about 100% to 300% in 4 hours. Thus it is thought to be useful in the treatment of infections of the retroperitoneum. During a clinical trial PIPC was administered to 16 patients with obstetrical and gynecological infections and it proved to be excellent in 4 patients, good in 10 patients and ineffective in 2 patients. Thus an overall efficacy rate of 87.5% was obtained. The only side effects observed was a slight transitory abnormality of liver function in 2 patients. Thus in the overall evaluation, this drug was considered to be useful in the treatment of infections in the obstetric and gynecological field.

Adult↗
PubMed1982

[Fundamental and clinical studies on cefotaxime in the perinatal period].

Fundamental and clinical studies on the perinatal use of cefotaxime (CTX, HR-756), a new cephalosporin antibiotic, were done, with the following results. 1. Following intravenous administration of 2 g of CTX, transport of CTX from maternal serum to umbilical cord serum and to amniotic fluid was found to be good. CTX was not transferred into mother's milk. 2. In clinical use, CTX was given to 16 pregnant patients with premature rupture of the membrane. It showed excellent efficacy in preventing perinatal infection. Five patients with perinatal infections were administered CTX, and in 4 patients CTX had good efficacy. No side effects were noted in any cases.

Amniotic Fluid↗
PubMed1981

[Pharmacokinetics of norethindrone and lynestrenol studied by HPLC (author's transl)].

The concentration of norethindrone in plasma samples from subjects receiving norethindrone (norethisterone) and lynestrenol orally was measured by high pressure liquid chromatography (HPLC). Norethindrone is a synthetic gestagen widely used in contraceptive formulations, and lynestrenol is also a synthetic gestagen which is metabolized to norethindrone in humans. But the evaluation of plasma norethindrone levels in subjects receiving lynestrenol has not yet been reported. After the administration of norethindrone, the peak level of norethindrone in the plasma was obtained within 2h, and the peak concentration in the plasma was about 3.5 ng/ml/mg norethindrone. During a period of 2-6hs after the administration of norethindrone, the half life of norethindrone in the plasma was approximately 1.8h, and during the period of 6-24hs, half life was variable. On the other hand, after the administration of lynestrenol, the peak level of norethindrone in the plasma was obtained within 4h, and the peak concentration of norethindrone was about 1.9 ng/ml/mg lynestrenol. During a period of 4-12hs, the half life of norethindrone was about 2.5h. The peak of the norethindrone level after the administration of lynestrenol was lower and appeared later than that after the administration of the same dose of norethindrone. Norethindrone in plasma in subjects receiving lynestrenol could be measured for a longer period than in those receiving the same dose of norethindrone. These results suggest that lynestrenol is stored in fat tissue and is slowly metabolized to norethindrone.

Administration, Oral↗