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Biomedical subjects

O Tanizawa

Publications and source records attributed to O Tanizawa.

At least 199 records · Page 11Linked to original sources
PubMed1989

Peripheral K cells in normal human pregnancy: decrease during pregnancy and increase after delivery.

Peripheral blood levels of K cells were measured in normal pregnant and post-partum women by a plaque-forming cell technique that detects K cells on the basis of their activity of antibody-dependent cell-mediated cytotoxicity (ADCC). Peripheral K cells decreased throughout normal pregnancy (n = 46; 7.8 +/- 3.4%, P less than 0.01; 0.13 +/- 0.08 X 10(9)/l, P less than 0.001) and increased in the post-partum period (n = 17; 14.2 +/- 6.1%, P less than 0.05; 0.32 +/- 0.20 X 10(9)/l, P less than 0.01) in comparison with those in normal non-pregnant controls (n = 29; 10.5 +/- 4.2%; 0.20 +/- 0.09 X 10(9)/l). These findings suggest that a decrease of K cells during pregnancy may contribute in part to maternal acceptance of the fetal allograft and that the post-partum increase of K cells may represent a post-partum increase of cell-mediated cytotoxicity, which may contribute to natural defense against puerperal infection.

Adult↗
PubMed1989

Zygosity determination of multiple pregnancy by deoxyribonucleic acid fingerprints.

We used a new method of deoxyribonucleic acid analysis to determine zygosity in multiple pregnancies. This method uses a minisatellite core probe, requires only a small amount of deoxyribonucleic acid, and detects the restriction fragment length polymorphisms that are a result of allelic differences in the number of tandem repeats that contain the core sequence. Southern blot hybridization showed an individual-specific deoxyribonucleic acid fingerprint and each polymorphic band in the sibling could be identified within one (but not both) of the parents. Identical deoxyribonucleic acid fingerprints among the siblings of multiple pregnancy indicate they must be monozygotic. This method is sufficiently reliable and rapid so the determination of zygosity in multiple pregnancy can be made the same day the fetal deoxyribonucleic acid is made available.

DNA↗
PubMed1989

Immunoreactive corticotropin-releasing hormone, adrenocorticotropin and cortisol in human plasma during pregnancy and delivery and postpartum.

The activity of the hypothalamo-pituitary adrenal axis was examined, by measuring the levels of immunoreactive (IR) corticotropin-releasing hormone (CRH), adrenocorticotropin (ACTH) and cortisol (F) in human plasma during normal pregnancy and after delivery with or without complications and during normal postpartum using a specific RIA. The level of IR-CRH in maternal plasma increased progressively during pregnancy, increased further at delivery and declined rapidly to the non-pregnant level on the 1st day postpartum. The level of IR-F in maternal plasma also increased progressively during pregnancy, increased further at delivery, but decreased slowly postpartum, not returning to the non-pregnant level within 5 days. Significant correlations were found between the level of IR-CRH and IR-ACTH, IR-CRH and IR-F, and IR-ACTH and IRF in maternal plasma both during pregnancy and after delivery. It is noteworthy that the concentration of IR-CRH in the maternal plasma at delivery was higher in multiple pregnancy than in normal pregnancy, and that the level of IR-CRH in the umbilical cord in uncomplicated cases was much lower than that in the maternal plasma, and was significantly lower than those in the umbilical cord plasma in cases of asphyxia, IUGR or premature delivery. The level of IR-F, not IR-CRH and IR-ACTH, at normal vaginal delivery was significantly higher than that at elective cesarean section. On these results, we investigated the feto-maternal-hypothalamo-pituitary adrenal axis during pregnancy and delivery, in which CRH plays an important role.

Adrenocorticotropic Hormone↗
PubMed1989

Effective method for prediction of transient hypothyroidism in neonates born to mothers with chronic thyroiditis.

An effective method of prediction of neonatal transient hypothyroidism was examined in 105 neonates (including a pair of twins) born to mothers with chronic thyroiditis (92 mothers with goitrous Hashimoto's disease and 12 with primary atrophic hypothyroidism). Antithyroid microsomal antibody was measured by a hemagglutination technique (MCHA), and antithyroid-stimulating hormone (TSH) receptor antibody by both radioreceptor assay (TBII) and biologic thyroid-stimulation blocking assay (TSBAb). For generalization of predictive criteria, the expression of TBII activity was standardized using standard serum made taking units of MRC-LATS-standard B as a reference, and that of TSBAb activity was standardized as the degree of dilution with normal pooled serum to attain 50% inhibition of TSH (100 microU/ml)-induced cyclic adenosine monophosphate increase (TSBAb50). The MCHA titer in maternal serum at delivery correlated well with that of the corresponding cord serum, but not with the free thyroxine (T4) index or the TSH level in cord serum. TBII activity was positive in only 4 of 12 mothers with primary atrophic hypothyroidism, TSBAb activity was also positive only in these four mothers, and neonatal thyroid dysfunction was observed in three of their neonates. Two of these neonates developed transient hypothyroidism requiring T4 treatment, and the t third developed mild transient hyperthyrotropinemia with normal T4 and triidothyronine levels. The mothers whose neonates showed transient hypothyroidism had TBII activities of more than 300 U/ml and TSBAb50 activities of more than 300. Ninety-two mothers with goitrous Hashimoto's disease had neither TBII nor TSBAb activity, irrespective of their thyroid function, and delivered euthyroid babies.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantibodies↗
PubMed1989

Evaluation of TSH receptor antibody by 'natural in vivo human assay' in neonates born to mothers with Graves' disease.

Neonatal thyrotoxicosis induced by transferred TSH receptor antibody (TRAb) is the ideal human in-vivo experimental system for the evaluation of TRAb. The clinical significance of circulating TRAb in Graves' disease was evaluated by this 'natural in-vivo human assay'. TRAb activity in vitro was measured by radioreceptor assay (thyrotrophin-binding inhibitor immunoglobulin, TBII) and sensitive cAMP accumulation assay using FRTL-5 cells (thyroid-stimulating antibody, TSAb). Further, the binding-stimulation index (B-S index) was newly introduced, which was the most useful indicator for prediction of neonatal thyrotoxicosis, calculated as the product of TBII and TSAb (Tamaki et al., 1988a). Maternal serum TRAb indices showed highly significant correlations with the serum free T4 index (FT4I) and free T3 index (FT3I) in neonates (5-10 days after birth) born to 20 mothers with Graves' disease who had positive TBII and/or TSAb (FT4I: r = 0.825 for TBII, r = 0.908 for TSAb, r = 0.944 for the B-S index, P less than 0.001; FT3I: r = 0.622 for TBII, P less than 0.01, r = 0.812 for TSAb, r = 0.791 for the B-S index, P less than 0.001; n = 20). In contrast, in 57 untreated adult patients with hyperthyroid Graves' disease, the FT4I and FT3I levels were not correlated with any of the TRAb indices. The linear regression relationship between the B-S index and FT4I found in neonates was applied to values in adult patients with Graves' disease, and the patients were divided into three groups on the basis of the 95% confidence limit: high, normal, and low responders of thyroid hormone (FT4I) secretion to the B-S index. FT4I and the ratio of FT4I to the B-S index were highest and the TRAb indices were lowest in the high responders, while FT4I and the FT4I/B-S index ratio were lowest and the TRAb indices were highest in the low responders. The FT4I/B-S index ratio was inversely correlated with the titres of antithyroid microsomal antibody in all the adult patients with untreated Graves' disease (r = -0.288, P less than 0.05). The results suggest that in-vitro assays using animal thyroid cells and cAMP as an index of response are suitable for detecting circulating thyroid stimulating activity in vivo. Secretion of thyroid hormones in Graves' disease may be regulated not only by circulating thyroid-stimulating antibodies but also by intrathyroidal stimulatory factors or by inhibitory or destructive factors.

Antibodies↗
PubMed1989

Plasma concentrations of human atrial natriuretic peptide at vaginal delivery and elective cesarean section.

The change in plasma concentration of atrial natriuretic peptide (hANP) at delivery was examined by measuring the concentrations of hANP in plasma samples from 21 subjects after 36 weeks of normal pregnancy, 22 subjects after normal spontaneous delivery and 20 subjects after elective cesarean section. The maternal plasma concentration of hANP after normal delivery (38.0 +/- 8.2 fmol/ml, mean +/- S.E.M.) was significantly higher than that after 36 weeks of normal pregnancy (16.8 +/- 2.3 fmol/ml), but its concentration after cesarean section was not different from that after 36 weeks of pregnancy. After normal delivery, the plasma concentration of hANP in the umbilical artery (66.9 +/- 11.8 fmol/ml) was also significantly higher than that in the umbilical vein (35.1 +/- 7.3 fmol/ml). In contrast, after elective cesarean section, the hANP levels in the umbilical artery and vein were not significantly different. These results suggest that hANP secretion into the maternal and fetal circulation may be stimulated by the dynamic movement of the mother in labour and the stress of the fetus at delivery, respectively.

Adult↗
PubMed1989

Impaired susceptibility of human trophoblast to MHC nonrestricted killer cells: implication in the maternal-fetal relationship.

Mammalian pregnancy has frequently been termed "Nature's allograft," and there is developing evidence that the placental trophoblast cells in their key position at the maternal fetal interface are responsible for escape mechanisms to the maternal immune system. In this paper, we show impaired susceptibility of human trophoblastic tumor cells to major histocompatibility complex (MHC) nonrestricted cytotoxicity systems such as natural killer (NK) cells and lymphokine-activated killer (LAK) cells. LAK cells were induced by the culture of peripheral blood mononuclear lymphocytes (PBL) in recombinant interleukin-2 (rIL-2). Among 21 cultured cell lines derived from various tissues and organs tested, five choriocarcinoma-derived cell lines gave decreased levels of LAK lysis. Cold-target inhibition study and trinitrophenyl (TNP) modification experiment clearly indicated that the impaired sensitivity of trophoblast cells to LAK lysis is due to the decrease of a common target molecule recognized by LAK effector cells. It is suggested that the impaired susceptibilty of trophoblast to MHC nonrestricted killer cells should be functional for the survival of the semiallogeneic fetus.

Cytotoxicity, Immunologic↗
PubMed1989

Trophoblast-derived immunoregulatory factor: demonstration of the biological function and the physicochemical characteristics of the factor derived from choriocarcinoma cell lines.

An immunosuppressive factor released by choriocarcinoma cell lines was analyzed in the present study. It inhibited the proliferative responses of human T cells stimulated by lectins or alloantigens. It also blocked the generation of alloreactive cytotoxic T cells. The suppressive activity of the factor was detected in the responses of the T cells costimulated with 1 nM 12-O-tetradecanoyl phorbol 13-acetate and 1 microM A23187, suggesting the possibility that the factor acted on the intracellular signal transduction in T cells rather than interfering with early events such as T cell receptor signal transduction through cell membranes. Moreover, the factor acted directly on T cell proliferation pathways without activation of suppressor cells but did not act on T cell activation pathways. Taken together, all these findings expanded our previous reports on a factor released by normal trophoblasts, indicating the possible identity of the two factors. The physicochemical properties of the choriocarcinoma-derived factor were examined, and the biological significance of the factor during pregnancy was discussed in this paper.

Calcimycin↗
PubMed1989

Ovulation following combined therapy with wen-jing-tang and clomiphene citrate therapy in anovulatory women.

The effect of combined therapy with Wen-Jing-Tang and clomiphene citrate on anovulation was studied in 16 infertile patients who did not respond to clomiphene citrate alone. Wen-Jing-Tang was given at a dose of 5 g a day every day from day 2 of the menstrual cycles and clomiphene citrate was given at 150 mg a day for 5 days from day 5 of the cycle. Ovulation occurred in 43.8% of the patients and 48.6% of the cycles. No case of ovarian hyperstimulation syndrome or pregnancy were observed. These results suggest that the combined therapy with Wen-Jing-Tang and clomiphene citrate should be used before therapy with human menopausal gonadotropin.

Adult↗
PubMed1989

Mechanism of release of beta-endorphin from rat pituitary cells. Role of lipoxygenase products of arachidonic acid.

We investigated the effects of metabolites of arachidonic acid on the release of beta-endorphin-like immunoreactivity (beta-end-IR) from rat anterior pituitary cells. Anterior pituitary cells from female rats cultured with arachidonic acid released beta-end-IR in a dose- and time-dependent manner. To determine which metabolites of arachidonic acid stimulated the release of beta-end-IR, we examined the effects of an inhibitor of the cyclooxygenase, indomethacin, and an inhibitor of the 5-lipoxygenase, 2,3,5-trimethyl-6-(12-hydroxy-5,10-dodecadiynyl)-1,4-benzoquinone (AA-861). beta-end-IR release from pituitary cells induced by arachidonic acid was inhibited about 37% by AA-861, but was not affected by indomethacin. Other lipoxygenase inhibitors (eicosatetraynoic and nordihydroguaiaretic acid) also reduced the release of beta-end-IR induced by arachidonic acid. The effects of the 5-lipoxygenase products 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE) and leukotrienes (LTA4, B4, C4, and D4) on the release of beta-end-IR from rat pituitary cells were also examined. 5-HETE (1-50 microM) elicited a dose-dependent release of beta-end-IR from cultured pituitary cells, and 50 microM 5-HETE induced beta-endorphin release time dependently. LTA4 and LTB4 also significantly stimulated the release of beta-end-IR, but LTC4 and LTD4 had no effect. Other lipoxygenase products (12-hydroxy-5,8,10,14-eicosatetraenoic acid, 12-HETE; 15-hydroxy-5,8,10,14-eicosatetraenoic acid, 15-HETE) were also secretagogues at concentrations of above 1 microM.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Involvement of extracellular calcium and arachidonate in [3H] dopamine release from rat tuberoinfundibular neurons.

The mechanism of [3H]dopamine [( 3H]DA) release was investigated using primary cultures of dispersed cells from the rat tuberoinfundibular region, which contains tyrosine hydroxylase (TH)-like immunoreactive neurons. The calcium ionophore A23187 at 10 nM and above caused a significant and dose-dependent increase in [3H]DA release. In the presence of 50 microM A23187, [3H]DA release was detectable within 30 s and reached a plateau in 15 min. The induction of [3H]DA release by 50 microM A23187 was abolished by lowering the extracellular calcium concentration with 2 mM EDTA. Maitotoxin, another calcium-channel activator, also increased [3H]DA release at a concentration of 50 ng/ml. Exogenous additions of 100 mIU/ml phospholipase A2 and 10 microM arachidonate caused significant release of [3H]DA. Furthermore, A23187 stimulated [3H]arachidonate release from tuberoinfundibular dopaminergic (TIDA) neurons in a dose- and time-dependent manner. These results suggest that extracellular calcium and arachidonate are involved in the process of [3H]DA release from rat TIDA neurons.

Animals↗
PubMed1989

Suppression of serum immunoreactive human epidermal growth factor by acute increase in prolactin in women.

Epidermal growth factor (EGF) is known to stimulate proliferation of various mammalian cells and secretion of prolactin (PRL) from rat anterior pituitary tumor cells. The effect of an acute increase in serum PRL induced by thyrotropin releasing hormone (TRH) or metoclopramide (MCP) on the serum immunoreactive EGF concentration was examined in nine hyperprolactinemic patients and eight normoprolactinemic women. The basal level of serum EGF in normoprolactinemic subjects was 472.8 +/- 51.1 pg/ml (Mean +/- SEM), which was not significantly different from that in hyperprolactinemic patients (487.8 +/- 22.5 pg/ml). The serum EGF concentration was decreased to 40-50% of the basal level after the abrupt increase in serum PRL induced by the injection of TRH or MCP in normoprolactinemic subjects, but no significant change in serum EGF occurred in hyperprolactinemic patients after MCP injection, in spite of a significant increase in PRL. These results suggest that an acute increase of serum PRL in normoprolactinemic women, but not in hyperprolactinemic patients, suppresses serum EGF.

Adenoma↗
PubMed1989

Studies on GnRH agonist suppression of estrogen production in patients with endometriosis.

The chronic administration of GnRH agonists to women results in the reversible suppression of estrogen production by the ovary. In the present study, the mechanism of the GnRH agonist suppression of estrogen production was investigated in patients with endometriosis. During the treatment with intranasal buserelin spray, the concentration of serum estradiol-17 beta (E2) was suppressed to near-castrate levels. Despite this marked suppression of serum E2, immunoreactive LH and FSH levels in serum were not changed. On the other hand, serum bioactive LH was markedly reduced. It was also observed during the treatment that the pituitary LH pulse disappeared and pituitary response to exogenous GnRH was significantly suppressed. In contrast, ovarian response to human menopausal gonadotropin (hMG) was not altered during the treatment. These findings suggest that the GnRH agonist suppression of estrogen production in the patients with endometriosis is through both suppression of the secretion of biologically active LH and the reduction of the LH pulse, but not through a direct inhibitory effect on ovarian estrogen biosynthesis.

Administration, Intranasal↗
PubMed1989

Enzyme immunoassay for oxytocin.

A competitive, double antibody enzyme immunoassay for oxytocin in a heterologous system was developed. Horseradish peroxidase was conjugated with oxytocin using N-succinimidyl 3-(2-pyridyldithio) propionate, and rabbit anti-oxytocin serum was produced by immunization of oxytocin-bovine serum albumin complex which was prepared by the carbodiimide method. The sensitivity of the assay was 4 microIU/tube, which corresponded to 10 microIU per ml using 400 microliters of the sample which was extracted from the same volume of plasma by means of SEP-PAK C18 cartridges. The coefficients of variation for different levels of oxytocin ranged from 6.8-15.9% and 8.5-16.7%, for intra- and inter-assay. Recovery of oxytocin added to plasma after extraction was 99-117%. No or little cross-reaction with arginine- and lysine-vasopressin was found. Plasma oxytocin concentrations determined by the proposed enzyme immunoassay were well correlated with those determined by radioimmunoassay (r = 0.90).

Immunoenzyme Techniques↗
PubMed1989

Estrogen stimulates gonadotropin-releasing hormone release from rat hypothalamus independently through catecholamine and histamine in vitro.

Estradiol is known to stimulate gonadotropin-releasing hormone release from the rat medio-basal hypothalamus. Studies were made in an in vitro perifusion system on whether catecholamine and/or histamine was involved in estradiol-induced GnRH release. Normal cycling female rats were decapitated in diestrus II and their medio-basal hypothalami were combined and, perifused with Earl's balanced salt solution containing 0.01% bovine serum albumin bubbled with 95% O2 and 5% CO2. The levels of norepinephrine, dopamine, and histamine and of GnRH in the effluent were measured by HPLC and radioimmunoassay, respectively. Administration of 10(-6) mol/l estradiol resulted in releases of norepinephrine, dopamine, histamine and GnRH at levels of 98, 70, 91 and 288%, respectively, of initial values. Administration of 10(-6) mol/l norepinephrine or dopamine resulted in no increase in histamine release, and administration of 10(-6) mol/l histamine did not increase release of norepinephrine or dopamine. These data suggest that estradiol stimulates the releases of GnRH, catecholamine and histamine from the rat medio-basal hypothalamus, and that it increases GnRH release independently through catecholamine and histamine. As we found previously that norepinephrine or histamine stimulates GnRH release from the medio-basal hypothalamus, we conclude that estradiol stimulates releases of norepinephrine and histamine, resulting in GnRH release from the medio-basal hypothalamus.

Animals↗
PubMed1989

Discordant changes in serum anti-TSH receptor antibody and antithyroid microsomal antibody during pregnancy in autoimmune thyroid diseases.

Immunological effect of pregnancy on the level of anti-TSH receptor antibody (TRAb) and antithyroid microsomal antibody (MCAb) was examined serially in twelve patients; ten with active Graves' disease treated with antithyroid drugs for some time during pregnancy, one with previous Graves' disease with stimulating type TRAb, and one with primary atrophic hypothyroidism with blocking type TRAb. TRAb was measured by radioreceptor assay (TSH-binding inhibitor immunoglobulin, TBII) and MCAb was determined by radioimmunoassay. Among the ten patients with active Graves' disease, TBII level decreased as pregnancy progressed in seven but increased during pregnancy in three, whereas MCAb level decreased uniformly during pregnancy in all ten patients. However, possible immunosuppressive effect of antithyroid drugs on these antibody levels could not be completely excluded in these patients. On the other hand, in the two consecutive pregnancies of the patient with previous Graves' disease, TBII level increased "spontaneously" to 10-fold the initial value at 30 weeks during the first pregnancy, while it did not show consistent increase or decrease during the second one. Another patient with primary hypothyroidism showed increase in TBII level during pregnancy to 5-fold the initial value at week 28. In contrast to these TBII changes, MCAb levels and immunoglobulin concentrations decreased consistently during pregnancy in these two patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantibodies↗
PubMed1989

[Low sensitivity of choriocarcinoma cell lines to tumor necrosis factor (TNF)-alpha].

Sensitivity of cultured choriocarcinoma cell lines to tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma was examined and compared with that of other cultured tumor cell lines. Tumor cells were cultured with 1,000 mu/ml of TNF-alpha and/or 100 mu/ml of IFN-gamma for 24hr. Antitumor effects of the lymphokines were measured by 3H-thymidine uptake and tetrazolium salt (MTT) colorimetric assay. The results revealed that TNF-alpha and/or IFN-gamma had little anti-tumor effect on the choriocarcinoma cell lines tested, while they had cytostatic and cytotoxic effects on other cultured tumor cell lines including Panc-1 (pancreatic carcinoma cell line), Lovo (colon carcinoma cell line) and Ishikawa (uterine endometrial carcinoma cell line). We also examined the effect of TNF-alpha and IFN-gamma on the expression of major histocompatibility complex (MHC) class I antigens in these tumor cell lines by means of cellular binding radioimmunoassay. No enhancing effect was observed on choriocarcinoma cell lines after the treatment with TNF-alpha and/or IFN-gamma. These results suggested the existence of a unique property of choriocarcinoma cells which results in the resistance to host immune attacks.

Choriocarcinoma↗