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Biomedical subjects

O Tanizawa

Publications and source records attributed to O Tanizawa.

At least 361 records · Page 20Linked to original sources
PubMed1978

The time course change after castration in short-loop negative feedback control of LH by HCG in women.

The time course of change in the suppressive effect of human chorionic gonadotrophin (HCG) on luteinizing hormone (LH) and/or LH-beta following castration was studied by a specific LH-beta radioimmunoassay. At 14-50 days after castration 8 women were given 10 000 IU of HCG in a single intramuscular injection (group 1), 5 women were given 2000 IU of HCG in the same way (group 2), and 5 were injected with saline as controls (group 5). In addition, 5 women 6-15 months (group 3) and 7 women 3-8 years (group 4) after castration were given 10 000 IU of HCG. The serum concentrations of HCG in groups 1, 2, 3 and 4 reached peak levels of 209.4, 44.1, 210.6 and 238.6 uU/ml, respectively, 4 h after the HCG injection. The serum LH concentration in group 1 was reduced significantly (P less than 0.01) by HCG administration, but the reductions in the LH levels in groups 2, 3 and 4 after HCG injection were not significantly different from that of the controls. These findings suggest that the threshold of the short-loop negative feedback control of LH in women changes with time after castration.

Adult↗
PubMed1978

Pituitary LH response to LHRH during puerperium.

Forty puerperal women and 15 normally menstruating women used as controls were given 100 microgram of synthetic luteinizing hormone releasing hormone (LHRH) in a single intravenous injection. Serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and human chorionic gonadotropin (hCG) were measured by a specific radioimmunoassay (RIA). The LH-beta RIA method, which is unaffected by hCG at sample levels as high as 500 IU/ml, was used to determine serum LH levels. Basal serum FSH and LH levels determined immediately after delivery were lower than those in the follicular and luteal phases during the normal menstrual cycle. These levels rose gradually after delivery, and finally returned to normal levels during the 16th to 25th days of the puerperal period. Small, but significant, LH response to LHRH was observed 6-10 days after delivery, and gradually returned to normal thereafter, though the response was poor during the first 35 days of the puerperal period when compared with that of the controls. On the other hand, no FSH response to LHRH was observed until 16-25 days after delivery, when the response was greater than that of the controls.

Adult↗
PubMed1978

Changes of serum anti-thyroid antibodies during and after pregnancy in autoimmune thyroid diseases.

Changes of serum anti-thyroglobulin haemagglutination antibodies (TGHA) and anti-thyroid microsomal haemagglutination antibodies (MCHA) were observed during pregnancy and after delivery in Graves' disease and autoimmune thyroiditis. Both TGHA and MCHA decreased as pregnancy progressed, and sometimes they became negative in late pregnancy. Transient increases of TGHA and MCHA were observed after delivery and the antibody titres reached peaks about 3-4 months post-partum in more than halft the patients. In some patients, antibodies developed after delivery. Similar transient increases of antibodies were observed after spontaneous and therapeutic abortion. These changes seem to be induced by physiological and immunological changes occurring during pregnancy and after delivery.

Abortion, Spontaneous↗
PubMed1978

Changes of serum immunoglobulins IgG, IgA, IgM, and IgE during pregnancy.

The serum levels of immunoglobulins at various times throughout pregnancy were measured in 11 healthy women. The concentrations of IgG, IgA, and IgM decreased significantly in the second and third trimesters, the mean decreases at the second trimester being 18, 13, and 9%, respectively. When the decreases were expressed on the basis of serum total protein, the decreases in IgG and IgA were significant but the decrease in IgM was not. The level of IgE either decreased or increased during pregnancy. Maternal age, emesis, ABO-incompatibility, and the sex and weight of the baby at birth were not related to the initial concentration or to the extent of decrease of immunoglobulins during pregnancy. In a case of Rh incompatibility, increase of immunoglobulins was observed concomitantly with the transient appearance of anti-Rh(D) antibody. Immunoglobulin depletion in pregnancy seems to result from both immune suppression and hemodilution.

Adult↗
PubMed1977

LH concentrations in human maternal and cord serum.

Maternal blood and umbilical cord venous blood were collected immediately after delivery in 32 subjects who had completed normal birth during the 38 to 41 weeks of pregnancy, and the concentrations of human chorionic gonadotropin (hCG), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were determined by radioimmunoassay (RIA). The specific LH RIA utilized for the measurement of LH is unaffected by hCG at sample levels as high as 500 IU/ml. HCG concentrations were 10,370 +/- 1,480 mIU/ml (mean +/- SE) in mother's serum and 34.5 +/- 5.2 ml in cord serum, while LH concentrations were 0.729 +/- 0.055 and 0.438 +/- 0.033 ng/ml, respectively. The concentration of all 3 gonadotropins in maternal serum was greater than cord serum and the ratio was markedly high with 302:1 for hCG, while the ratio was smaller for LH, being 1.7:1, while that for FSH was 4.2:1. There was no difference in the levels of LH and FSH in relation to the sex of the fetus.

Adult↗
PubMed1977

Transient postpartum hypothyroidism: fourteen cases with autoimmune thyroiditis.

Twenty-five episodes of postpartum primary hypothyroidism were observed in 23 patients without thyroid hormone treatment: three were cases of irreversible hypothyroidism and the others were of transient hypothyroidism. The characteristics of transient postpartum hypothyroidism deduced by serial observations on 14 patients were [1] a high incidence of previous goiter; [2] thyroid enlargement at 1/2 to 4 months postpartum; [3] hypothyroidism at 3 to 5 months postpartum; [4] spontaneous recovery at 5 to 10 months postpartum; [5] high titers of antithyroid microsomal antibodies; and [6] persistence of small goiter. Transient postpartum hyperthyroidism before the occurrence of hypothyroidism and the recurrence of transient postpartum hypothyroidism were observed during two consecutive postpartum periods in two patients. Transient hypothyroidism was also observed in two patients after abortion. Fourteen of the 23 patients first noticed thyroid abnormality after delivery. These changes seem to be induced during the course of autoimmune thyroiditis by the immunologic changes occurring after delivery.

Abortion, Therapeutic↗
PubMed1977

Pituitary responses in LH secretion to LHRH during pregnancy.

Thirty-six pregnant women and 15 normally menstruating women were each given 100 microng of synthetic luteinizing hormone releasing hormone (LHRH) by a single intravenous injection. Human chorionic gonadotropin (hCG), luteinizing hormone (LH), and follicle stimulating hormone (FSH) levels were determined by specific radioimmunoassay (RIA) technics. For the determination of the serum LH levels, the LHbeta-RIA method, which is unaffected by hCG at sample levels as high as 500 IU/ml, was used. Serum concentrations of LH and FSH were lower in pregnant women than in the normal women in the follicular and luteal phases. While the release of LH was observed in pregnant women following the administration of LHRH, the average net increase was less than that seen in both the follicular and luteal phases. During pregnancy, there was a progressive decrease in the LH response to LHRH, but no release of FSH.

Adult↗
PubMed1977

Fine structure of noradrenaline containing nerve fibers in the median eminence of female rat demonstrated by in situ fixation of potassium permanganate.

Fine structure of noradrenaline (NA) terminals in the internal layer of the median eminence (ME) was elucidated by in situ fixation of potassium permanganate. The NA terminals in ME contained relatively large cored vesicles (about 1000 A) together with a large number of small core vesicle (400-600 A). The most dominant feature that NA terminals show is the closed contact with ependymal cells and their processes. In the bulging abutting on the contact membrane, some of core vesicles fused or touched the membrane appearing to release the content into intercellular space or take up NA from the space. This finding shows that the NA terminals abutting on the ependymal cells and their processes have a close contact with them and give an important influence on regulation of ependymal function. Our present study further revealed that the NA terminals also had a close contact not only with the axon terminals in which ordinary spherical non-cored vesicles were exclusively present but also with the axonal fibers of neurosecretary system. These findings would infer complicated function of NA in ME.

Animals↗
PubMed1976

[Studies on the measurements of LH-releasing hormone (LH-RH) by radioimmunoassay (RIA) (author's transl)].

The radioimmunoassay for LH-RH would aid greatly in the assessment of hypothalamic function. The anti-LH-RH was prepared by immunizing rabbits with LH-RH conjugate of BSA. 125I-LH-RH was prepared by the lactoperoxidase method and Sephadex G-10 column chromatography. The double antibody RIA technique was employed. On the assay of biological materials, LH-RH was extracted by methanol because LH-RH was rapidly destroyed in the serum, and this breakdown could not be prevented by benzamidine or 2,3-dimercaptopropranol. Sensitivity of this RIA system ranged from 10 tp 104 pg/ml, and the coefficient of variations of intra- and interassay were 12.9% and 9.% respectively. The serum LH-RH levels of men in a normal gonad state were below 10 pg/ml, and those of women in a normal gonad state in the early follicular or luteal phase were below 50 pg/ml. Whereas those of postmenopausal or castrated women were increased, and were highest in women with several gonadal disturbed states. The disappearance curve of LH-RH in women was characterized by two exponentials, t(1/2) of the initial component was 4.9 min, and that of the second component 24.6 min. Urinary excretion of exogenously administered LH-RH was also studied.

Amenorrhea↗
PubMed1976

Pituitary-thyroid function in trophoblastic disease.

Pituitary-thyroid function was assessed in 12 patients with trophoblastic disease (4 hydatidiform mole, 3 invasive mole, and 5 choriocarcinoma). Thyroid-stimulating activity was detectable, by means of the McKenzie bioassay, in 6 patients (Group 1) but not in the other 6 patients (Group 2). In Group 1 serum thyrotropin (TSH) determined by radioimmunoassay was mostly undetectable and did not respond to the administration of thyrotropin-releasing hormone (TRH) determined by radioimmunoassay was mostly undetectable and did not respond to the administration of thyrotropin-releasing hormone (TRH), while in Group 2 basal TSH was detectable in half of the patients and responded to TRH in all cases. Serum concentrations of total thyroxine (T4) (18.7 +/- 2.0 mug/100 ml, mean +/- SE), free T4 (4.9 +/- 0.04 ng/100 ml), total triiodothyronine (T3) (352 +/- 72 ng/100 ml), and free T3 (0.57 +/- 0.11 ng/100 ml) in Group 1 were statistically greater than those in Group 2 (total T4, 9.2 +/- 1.0 mug/100 ml, free T4, 2.0 +/- 0.2 ng/100 ml; total T3 156 +/- 20 ng/100 ml, and free T3 0.23 +/- 0.03 ng/100 ml). Free T4 and T3 fractions were within normal limits in both groups. After treatment of 5 patients in Group 1, the thyroid stimulating activity determined by bioassay dropped to undetectable levels, the serum concentrations of thyroid hormones decreased to normal limits, and TSH response to TRH became positive. These findings indicate that an abnormal thyroid stimulator, derived from the trophoblastic tissue, stimulated the thyroid hormone secretion from the thyroid gland and in turn suppressed TSH response to TRH in some patients with trophoblastic disease.

Adult↗
PubMed1976

Suppression of luteinizing hormone in castrated women by the administration of human chorionic gonadotropin.

The suppressive effect of human chorionic gonadotropin (hCG) on luteinizing hormone (LH) and/or LH-beta was studied by specific LH-beta radioimmunoassay following hCG administration. Eight castrated women were each administered 10,000 IU of hCG in a single intramuscular injection and five women in the control group were injected with saline. The serum level of hCG increased after the injection, reaching 217.6 mIU/ml after 8 h. There was a significant suppression of LH levels as compared to those of the control group and the pre-injection levels: 68.2% 1 h after injection, 64.7% after 2h, 65.5% after 4 h, 77.0% after 8 h, 78.6% after 12 h, and 78.2% after 24 h. There was no significant suppression of the follicle-stimulating hormone (FSH) as compared to the preinjection and control values. Serum concentration of estradiol1 was not detectable either before or after the hCG injection. We conclude that hCG has a suppressive effect on LH and/or LH-beta secretion not mediated by estradiol.

Adult↗