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Biomedical subjects

N Uchida

Publications and source records attributed to N Uchida.

At least 235 records · Page 13Linked to original sources
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

Growth-stimulative effect of estrogen on androgen-dependent Shionogi carcinoma 115.

The stimulative effect of 17 beta-estradiol on the growth of androgen-dependent Shionogi carcinoma 115 and estrogen receptor in the tumor were studied. The incorporation of 17 beta-[3H]estradiol following a single injection of 17 beta-[3H]estradiol into tumor-bearing animals was 5- to 20-fold higher in the tumor than in the spleen and blood. Scatchard plot analyses showed that the tumor cytosol possessed a 17 beta-estradiol-binding site having a high affinity for 17 beta-estradiol [Kd 1.1 +/- 0.1 nM (S.E.)]. Competition experiments demonstrated that the 17 beta-estradiol binding was specific only for estrogenic compounds. Using sedimentation coefficient obtained by high-salt sucrose gradient (4.0S) and Stokes radius obtained by gel chromatography on Sephadex G-200 (46 A), the molecular weight of 17 beta-estradiol-binding component in the tumor cytosol was estimated to be 76,400. In castrated DS mice, a slight but significant increase in growth of s.c. grafted tumors was found by daily s.c. injections of either 17 beta-estradiol or 10 micrograms per mouse of testosterone propionate. Growth of the tumor maintained by 10 micrograms of testosterone propionate was augmented markedly by the addition of 4 micrograms of 17 beta-estradiol, and the growth approached the level induced by 100 micrograms of testosterone propionate. Simultaneous injections of bromocryptine inhibited an increase in 17 beta-estradiol-induced prolactin secretion but had no effect on the 17 beta-estradiol-enhanced tumor growth. These results demonstrate for the first time the stimulative effect of estrogen on the growth of androgen-dependent Shionogi carcinoma 115. The tumor contains typical estrogen receptor, which might be able to transmit estrogen signal to tumor cell nuclei with regard to tumor growth.

Androgens↗
PubMed1984

[Rapid measurement of estriol & estradiol by high performance liquid chromatography (HPLC)].

Measurement of Estriol (E3) and Estradiol (E2) within 25 minutes by high performance liquid chromatography (HPLC) was achieved in this study and the values were compared with those of radioimmunoassay (RIA). A totally computerized HPLC method was developed for measuring unconjugated E3 and E2 in the sera of pregnant women. The sera samples were injected directly into the apparatus and transferred to a pretreatment column where estrogens were absorbed while hydrophilic components such as proteins and carbohydrates were excluded. The estrogens then passed through another separation column containing a new type of polymer gel. The mobile phase consisted of an acetonitrile/water mixture, and separation was achieved by means of a reversed phase mechanism. The eluent was monitored for fluorescence. All these procedures were monitored and controlled with a built-in microcomputer. The sera samples from 61 normal pregnant women at 20 to 41 weeks of pregnancy were simultaneously assayed by HPLC and RIA. The correlation of values obtained from HPLC and RIA was; E3: Y = 0.875X-0.172, the coefficient of correlation was 0.899, E2: Y = 0.972X + 6.791, the coefficient of correlation was 0.841 (Y = RIA values, X = HPLC values). The quick measurements of E3 and E2 by HPLC can be a useful method in evaluating the feto-placental function.

Chromatography, High Pressure Liquid↗
PubMed1983

Effects of pertussis toxin on delayed-type hypersensitivity responses and on the activity of suppressor T cells on the responses.

Experiments were performed on mice to investigate the effects of pertussis toxin (PT) on delayed-type hypersensitivity (DTH) to ovalbumin (OA) and on the activity of suppressor T cells on the DTH (DTH-Ts). Mice immunized with alum-precipitated ovalbumin showed a transient DTH, which was determined as footpad swelling which disappeared 2 weeks after immunization. Maximal footpad swelling was observed 24 hr after DTH elicitation. On the other hand, when mice received PT (2 micrograms/mouse) at the time of immunization, the transient DTH became an enhanced and persistent DTH, which persisted for at least 4 weeks. In addition, the time of maximum footpad swelling was delayed from 24 to 48 hr after DTH elicitation. The immune spleen T cells from PT-treated mice showed a persistently high ability to transfer DTH into syngenic naive mice. DTH-Ts was induced in spleens of mice injected iv with OA-coupled syngeneic spleen cells. However, when these mice received PT at the time of suppressor induction, their spleen cells revealed considerably reduced suppressor activity. The activity of DTH-Ts was also reduced when DTH-Ts were either treated in vitro with PT or transferred into PT-injected recipient mice. From these results, interference with the suppressor function of DTH-Ts from PT was considered to be, at least in part, as an enhancing mechanism of DTH.

Animals↗
PubMed1983

Properties of cloned T cells that mediate delayed-type hypersensitivity against ovalbumin in mice.

Cloned T-cell lines that mediate delayed-type hypersensitivity (DTH) against soluble protein antigen, ovalbumin (OA), were established in (C57BL/6 X DBA/2)F1 mice and their properties were examined. They induced antigen-specific delayed-type footpad reactions, characterized histologically by a predominant mononuclear cell infiltration, when transferred intravenously into syngeneic mice. Morphologically, they were medium or large lymphoblasts with granules in the cytoplasm and expressed Lyt 1 cell surface antigens. One of them proliferated antigen specifically under the presence of both C57BL/6 and F1 accessory cells, while others proliferated antigen specifically only under the presence of F1 accessory cells. They also produced macrophage-activating factor (MAF) and substances which mediate a DTH-like footpad inflammatory reaction with a maximum 6 hr after injection into the footpad of normal mice, when incubated in the presence of specific antigen and specific accessory cells in a serum-free medium for 24 hr. These results demonstrate that cloned DTH-effector T cells, established here against soluble protein antigen, are Lyt 1-positive, large lymphoblasts and that they produce MAF and footpad-reactive inflammatory substances antigen specifically under the presence of specific accessory cells.

Animals↗
PubMed1983

Effect of Bordetella pertussis leukocytosis (lymphocytosis)-promoting factor (LPF) on the physical lymphoepithelial-cell association studied with the use of an in vitro model of mouse thymus.

The effect of highly purified leukocytosis (lymphocytosis)-promoting factor (LPF) of Bordetella pertussis on physical lymphocyte and reticuloepithelial (RE) cell association was studied in an in vitro thymus model. First, a simplified in vitro system to assess the lympho-RE-cell association was developed. A completely confluent layer of thymic RE cells was formed by cultivating trypsinized thymus cell suspensions from 2- to 7-day-old mice. When thymic lymphoid cells were seeded on this cell layer and cultivated overnight, a significant proportion of them were found underneath the RE cell layer. This physical lympho-RE-cell association was quantitated by counting the lymphoid cells underneath the RE cell layers. Second, the effect of LPF on this physical lympho-RE-cell association phenomenon was investigated. Addition of LPF to the culture markedly inhibited the formation of the lympho-RE-cell complex; that is, it inhibited the infiltration of lymphoid cells under the RE cell layer. LPF rendered a nearly maximal level of inhibitory effect at a dose of 0.1 ng/ml. Furthermore, LPF enhanced the liberation of lymphoid cells from preformed lympho-RE-cell complexes. On the other hand, LPF had no direct cytotoxic effect on lymphoid cells at doses below 1 microgram/ml. In order to investigate whether LPF produced the effect by acting on lymphoid cells, RE cells, or both, the following experiments were performed. When lymphoid cells were pretreated with LPF and added to normal RE cell layers, the lympho-RE-cell association was maximally inhibited above the dose of 1 ng/ml. Treatment of these LPF-treated lymphoid cells with anti-LPF antibodies failed to abrogate the effect of LPF. When RE cell layers were similarly pretreated with LPF and were cultivated with normal lymphoid cells, however, much higher doses of LPF, above 100 ng/ml, were required for maximal inhibition. Furthermore, treatment of these LPF-treated RE cells with anti-LPF antibodies abrogated the effect of LPF. Therefore, the apparent effect of LPF on RE cells was considered to be due to the carry-over by RE cells of LPF, which should directly act on lymphoid cells at extremely low doses. On the basis of these results, it was concluded that LPF acted directly on lymphoid cells without mediation of RE cells. These in vitro results appear to parallel the effects of LPF in vivo, where it induces a depletion of cells in the thymus. The model may be useful to study this phenomenon and the concomitant accumulation of blood lymphocytes.

Animals↗
PubMed1983

Effect of adjuvant endocrine and adjuvant chemoendocrine therapies on metastasis of androgen-dependent Shionogi carcinoma 115.

Shionogi carcinoma 115 is an androgen-dependent tumor, defined by its failure to grow in either female or castrated male DS mice, and by its ability to grow in intact male DS mice as well as in female or castrated male DS mice given androgen. Since spontaneous lung metastasis was found in about 50% of intact male DS mice on the 40th day after s.c. transplantation of the tumor, we investigated the effect of various therapies on development of metastasis. Therapies were started on the 25th day after transplantation. Castration alone did not reduce the frequency of metastasis, and tumor excision alone reduced the frequency slightly. However, castration following the tumor excision showed an excellent effect. Chemotherapy (cyclophosphamide, 80 mg/kg body weight, three times) with or without tumor excision also showed a beneficial effect, and the combination of the tumor excision, castration, and chemotherapy was the most effective among various therapies examined. These results indicate that the Shionogi carcinoma 115 tumor is a useful model for therapy against metastasis of human hormone-dependent cancers.

Androgens↗
PubMed1982

[Development of a fetoscope and its clinical application].

One of the major goals in modern obstetrics is to provide more detailed informations of prenatal fetal physiology. Since 1972, more than 200 amniocentesis were performed in our hospital and the importance of prenatal genetic diagnosis has been recognized. But amniocentesis has the limitations which are 1) the lack of expression of many single gene hereditary disorders in amniotic fluid and its cells, 2) the large percentage (90%) of nonviable fetal cells in any given sample, 3) the length of time required to culture fetal cells. Accordingly the necessity of development of other methods to obtain further direct data on the fetus from the uterine cavity has been indicated. Among gynecological endoscopies, fetoscopy which is direct visualization of the fetus by introduction of an endoscope into the amniotic cavity is expected to obtain direct information from the uterine environment in pregnant women. By our newly developed fetoscope, we investigated clinical indications and contraindications of fetoscopy as well as future possibilities of this endoscope. Our present study indicates that further developments and future benefits of fetoscopy entirely depend on the progress of laboratory techniques which can provide more accurate data through specimens obtained fetoscopy.

Adult↗
PubMed1981

Adjuvant chemo-endocrine therapy for androgen-dependent mammary tumor in mice.

About 500 male DS mice grafted with androgen-dependent Shionogi carcinoma 115 (SC115) were used. When the tumor diameter reached about 20 mm (approximately 25 days after transplantation), excision of the tumor and/or castration were carried out. The injection of cyclophosphamide (80 mg/kg body weight X 3 at 7-day intervals) was started from the day after excision. In mice with excised tumor, adjuvant chemo-endocrine therapy was the most effective treatment examined; cumulative 120-day mortalities after transplantation of tumors in non-treated, adjuvant endocrine therapy, adjuvant chemotherapy and adjuvant chemo-endocrine therapy groups were 91%, 29%, 21% and 0%, respectively. Castration induced development of clusters of androgen-independent cancer cells in androgen-dependent SC115 tumor. In mice without tumor excision, the chemo-endocrine therapy was again the most effective treatment, though 86% of mice died by the 120th day after tumor transplantation. These findings suggest the usefulness of adjuvant chemo-endocrine therapy for achieving complete remission in hormone-dependent tumors.

Androgens↗
PubMed1980

Kinetic studies of the intracellular transport of procollagen and fibronectin in human fibroblasts. Effects of the monovalent ionophore, monensin.

The monovalent ionophore, monensin, has been found to inhibit the secretion of both procollagen and fibronectin from human fibroblasts in cell culture. The kinetics of inhibition, as well as those for the release of inhibition, suggested that both proteins may be cotransported in the cell. In the present study, we have examined the intracellular translocation and release into the culture medium of procollagen and fibronectin, in the presence or absence of monensin. Pulse-chase studies were combined with subcellular fractionation of the fibroblasts to determine the rates of intracellular movement. We found that monensin did not significantly affect either the subcellular fractionation, or the distribution of organelle marker enzymes along the gradient, and that procollagen moved from a region of high buoyant density (primarily endoplasmic reticulum), through a mid-density region (primarily Golgi elements), to a region of low buoyant density before exiting from the cell. Monensin markedly decreased the rate of transit from one region to the other; kinetic analysis of the data showed a greater than 3-fold decrease in the rate constants for intracellular movement into the low buoyant density components and thence to the culture medium. The density gradient distribution of fibronectin was affected by monensin in similar fashion, indicating that it and procollagen probably follow the same intracellular route. Since monensin causes both proteins to accumulate in highest abundance in regions of the density gradient corresponding to Golgi and endoplasmic reticulum, the site of ionophore blockade appears to be within the Golgi apparatus. Thus, procollagen and fibronectin share a common intracellular route prior to entering the Golgi region of the cell.

Biological Transport↗