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Biomedical subjects

Y Endo

Publications and source records attributed to Y Endo.

At least 667 records · Page 37Linked to original sources
PubMed1985

Highly sensitive immunoenzymometric assay for human thyrotropin.

A sensitive assay procedure for immunoenzymometric assay of serum thyrotropin (TSH) was developed by making several modifications of the Enzymun-Test TSH kit (Boehringer, Mannheim GmbH). Serum samples were first incubated in plastic tubes precoated with monoclonal antibodies specific to the beta subunit of human TSH. After the tubes were washed, the TSH bound to the tubes was detected with peroxidase-conjugated polyclonal antibodies to TSH. The sensitivity of the assay was 0.2 milli-int. unit/L, and the intra-and interassay CVs were less than 10%. Analytical recovery was 96 to 106%. The normal basal range of TSH was 0.5 to 4.8 milli-int. units/L. The basal levels of TSH in all but one of 48 thyrotoxic patients with Graves' disease were less than 0.2 milli-int. unit/L, clearly different from those of normal subjects. Thyrotoxic patients in early normal pregnancy showed TSH concentrations of 1.7 to 2.9 milli-int. units/L by conventional double-antibody radioimmunoassay, possibly from cross reactivity with human choriogonadotropin, but undetectable TSH by this method. Measurement of basal TSH by this sensitive assay can be used as an initial screening test for thyroid dysfunction.

Adult↗
PubMed1985

Enzyme immunoassay of free thyroxin in dried blood samples on filter paper.

We describe a double-antibody enzyme immunoassay for determination of free thyroxin (FT4) in dried blood samples on filter paper, with use of a T4-beta-D-galactosidase complex. The measurable range of FT4 concentration in two 3-mm blood discs, each of which contained about 2.7 microL of blood, was 1.9 to 93 ng/L, as determined by comparison with concentrations of FT4 in known serum standards. FT4 in blood samples dried on filter paper was stable for at least four weeks when kept dry at -20 degrees C, room temperature, or 37 degrees C. The mean coefficients of variation were 7.6% (within assay) and 6.4% (between assays). Results for FT4 by this method correlated well with those for serum determined by radioimmunoassay (r = 0.98). The proposed method can be used to differentiate persons with hyper- and hypothyroidism from normal subjects and those with abnormal concentrations of thyroxin-binding globulin. The procedure seems suited for screening studies.

Adult↗
PubMed1984

Biological effects of trilostane in vitro on oocyte maturation and fertilization in the hamster.

The effects of the inhibition of steroidogenesis by trilostane on oocyte maturation were examined by studying spontaneous maturation and fertilization in vitro. 10(-6)M trilostane had no influence on the meiotic process, whether the oocytes were naked or not. At a concentration of 10(-6)M and 10(-7)M trilostane, low normal pronuclear formation and high polyspermy were found during in vitro fertilization. However, no retarded male pronuclear development could be detected in the trilostane-treated group. Thus, steroid producing activity within ova is apparently necessary to prevent multiple sperm penetration, but it has no effect on meiosis or the action of the so-called male pronucleus growth factor (MPGF).

3-Hydroxysteroid Dehydrogenases↗
PubMed1984

Induction of ornithine decarboxylase in mouse tissues following the injection of mitogenic substances. Enhancement by actinomycin D.

Experiments were carried out to study the mechanism of the induction of ornithine decarboxylase (ODC) in mouse tissues by the injection of a lipopolysaccharide (LPS). In addition to LPS, various mitogenic substances, such as concanavalin A, pokeweed mitogen, polyI:polyC and a phorbol diester, induced ODC in the liver and the spleen of mice at 4.5 hr after injection. Non-mitogenic immuno-stimulants or inflammatory agents, such as zymosan, carrageenan, N-acetylmuramyl-L-alanyl-D-isoglutamine, glycogen, D-galactosamine and interferon, did not induce the enzyme. ODC induction by LPS in C3H/HeJ mice, the lymphocytes and/or macrophages of which are known to be less responsive to LPS, was much less than in C3H/He and ddI mice. ODC induction by LPS was suppressed by dexamethasone and cycloheximide. Actinomycin D did not suppress ODC induction by LPS but, rather, enhanced it. These results suggest that (1) lymphocytes and/or macrophages may participate in the induction of ODC by mitogenic substances as well as by LPS, (2) ODC may be induced by mitogenic substances without the synthesis of RNA, and (3) the translation of existing RNA may be accelerated by actinomycin D.

Animals↗
PubMed1984

Indirect immunofluorescence studies on the steroid-producing activity of hamster ova.

Steroidogenesis in the unfertilized hamster ova was investigated by indirect immunofluorescence study. delta 5-3 beta-Hydroxysteroid dehydrogenase (delta 5-3 beta-HSD) activity was found in hamster follicular and ovulatory ova with pregnenolone used as the substrate. A significant quantity of 17 beta-estradiol was detected in the ooplasm of follicular and ovulatory ova. No progesterone was found. The activity of delta 5-3 beta-HSD in follicular and ovulatory ova was inhibited by preincubation with 10 IU of human chorionic gonadotropin (hCG) in 1 ml of phosphate buffer solution. Trilostane, a potent new inhibitor of the delta 5-3 beta-HSD system, was found to inhibit the activity of delta 5-3 beta-HSD in ovulatory ova in 1 ml of phosphate buffer solution at a concentration of 10(-7)M. After these results were obtained, steroidogenesis of hamster ova was suggested in an indirect immunofluorescence study, and the implications of steroidogenesis for oocyte maturation and subsequent fertilization are discussed.

3-Hydroxysteroid Dehydrogenases↗
PubMed1984

Ontogeny of endocrine cells in the gut of the insect Periplaneta americana.

The ontogeny of the endocrine cells of the gut of the cockroach Periplaneta americana was studied by immunohistochemistry. During embryogenesis, the midgut begins to be formed as an outgrowth of the foregut and hindgut invaginations. Gut endocrine cells with pancreatic polypeptide (PP)-like immunoreactivity begin to appear at the anterior and posterior ends of the forming midgut. These cells are restricted to the midgut epithelium, and no mitotic cells with PP-like immunoreactivity are observed. These results strongly suggest that the gut endocrine cells, at least those with PP-like immunoreactivity, are derived from precursor cells they have in common with other epithelial cells of the midgut.

Age Factors↗
PubMed1984

Fractionation of polyclonal antibody by isoelectric focusing--differences in cross-reactivity and affinity of rabbit clonotype anti-human thyrotropin antibody.

Immunoglobulin G (IgG) fractions prepared from three different batches of rabbit antihuman thyrotropin (hTSH) antisera were fractionated by agarose isoelectric focusing (IEF) in the pH ranges 3 to 10 and 5 to 8. Staining of protein in agarose gel after IEF showed that polyclonal IgG separated into more than 20 protein bands with isoelectric points (pIs) ranging from 6 to 9. The clonotype antibodies to hTSH were recovered from the fractions and subjected to radioimmunoassay for determination of the binding-affinity for hTSH and the cross-reactivity with human chorionic gonadotropin (hCG). The affinity constants of the antibodies recovered ranged from 6.4 X 10(9) M-1 to 3.1 X 10(10) M-1, and the cross-reactivities of the clonotype antibodies differed greatly. A good correlation was observed between the pIs of antibody molecules and their cross-reactivities: antibodies with higher pIs bound hCG more strongly than those with lower pIs. The correlation coefficients between the pIs and cross-reactivities were 0.83, 0.84, and 0.87 in three batches of antibody.

Animals↗
PubMed1984

Clinical significance of autorosette-forming cells in T-cell lymphoma.

The capability to form rosettes with sheep erythrocytes (E), antibody-complement-sensitized ox erythrocytes (EAC) and autologous erythrocytes (ARFC), and surface immunoglobulin determinations were studied using 21 lymph nodes and one tonsil with pathologically-proven non-Hodgkin's lymphoma and 10 lymph nodes with benign pathology. Fourteen of 22 non-Hodgkin's lymphoma patients (64%) had a high incidence of E-rosette formation and they were further differentiated into ARFC-positive and ARFC-negative lymphomas. The clinicopathological findings of the latter were compatible with those of adult T-cell leukemia. ARFC-positive lymphoma was regarded as non-Hodgkin's lymphoma of T-cell type and one patient showed lymphoblastic lymphoma with high ARFC counts. ARFC counts were very low in B-cell and non-T, non-B lymphomas. The results from benign lymph nodes were too variable to draw any conclusion, although ARFC counts were relatively high in lymphadenitis and hyperplasia.

Humans↗
PubMed1984

Heterogeneity of free valine pools for protein synthesis on free and membrane-bound polysomes in rat liver.

When rat liver was pulse-labeled with [3H]valine in vivo, the nascent peptide on membrane-bound polysomes was found to be more highly labeled than that on free polysomes. Nascent peptides were purified from both classes of polysomes and, after hydrolysis, the amino acids were reacted with 14C-labeled 1-fluoro-2,4-dinitrobenzene. The specific activity of [3H]valine was determined from the [14C]-dinitrophenyl-[3H]valine after purification by two-dimensional thin layer chromatography. With this approach we found that the specific activity of [3H]valine in the nascent peptide of membrane-bound polysomes was more than twice that of free polysomes. Moreover, when rats were pretreated with a lysosomal protease inhibitor, the differences between the specific activities of valine in nascent peptides of the two classes of polysomes tended to decrease. Our results indicate the existence of two distinct pools for valine used for protein synthesis in liver cells; one serves as a precursor for the synthesis of secretory proteins on membrane-bound polysomes and the other as a precursor for the synthesis of intracellular proteins on free polysomes.

Animals↗
PubMed1984

A prolactin producing tumor originated in the sphenoid sinus.

The case presented is a prolactin producing tumor originated in the sphenoid sinus of a 40-year-old woman. Histologically this tumor is a typical chromophobe adenoma of the pituitary gland. Human prolactin was immunohistochemically detected in the cytoplasm of most tumor cells. The tumor invaded around the pituitary gland and in the nasal cavity without distant metastasis. Clinically the patient showed hyperprolactinemia and amenorrhea.

Adenoma↗
PubMed1984

Induction of hypoglycaemia and accumulation of 5-hydroxytryptamine in the liver after the injection of mitogenic substances into mice.

Various mitogenic substances (concanavalin A, pokeweed mitogen, polyI : polyC and a phorbol diester), as well as lipopolysaccharides (LPS or endotoxins), produced hypoglycaemia after being injected into mice. However, non-mitogenic immuno-stimulants (zymosan, carrageenan, an adjuvant peptide and interferon) did not induce hypoglycaemia. All of the mitogenic substances also induced an increase in 5-hydroxytryptamine (5-HT) in liver, but the non-mitogenic substances did not have this effect. The time course of the development of hypoglycaemia was similar to that of the increase in liver 5-HT. The dose-dependence of the hypoglycaemia induced by LPS was similar to that of the increase in liver 5-HT. In C3H/HeJ mice, the macrophages and/or lymphocytes of the mice are known to be less responsive to LPS, and both the LPS-induced hypoglycaemia and increase in 5-HT were less in these mice than in control mice (C3H/He and ddI mice). These results suggest that macrophages and/or lymphocytes may participate in the induction of hypoglycaemia and the increase in 5-HT induced by mitogenic substances and LPS. A possible correlation between hypoglycaemia and the increase in hepatic 5-HT is discussed, although the relationship is not substantiated.

Adjuvants, Immunologic↗
PubMed1984

Properties of kininase in rat dental pulp.

A kininase, capable of degrading bradykinin, was partially purified from the dental pulp of rats, and its properties were investigated. Chromatography on both Sephadex G-200 and DEAE Sephadex A-50 columns gave a single peak of kininase activity. The molecular weight of the enzyme, estimated by gel filtration, was about 67,000, and the optimum pH for the enzymatic reaction was about 7.5. The enzyme appears to contain a labile SH group(s) that is essential for its activity, because CdCl2, HgCl2 (0.1 mM each), and p-chloromercuric benzoate (0.05 mM) inhibited the enzyme completely, while dithiothreitol retarded the loss of activity during storage. Of various peptides tested, bradykinin was the substrate most sensitive for the enzyme. The enzyme released several amino acids located in the C-terminal regions of bradykinin--angiotensin I and neurotensin--but only one C-terminal amino acid from des-Arg9--bradykinin and angiotensin II. In contrast, the enzyme did not release any amino acids from substance P, of which only the two amino acids in the N-terminal region are the same as those of bradykinin, but its C-terminal is blocked by an amino group. Although the enzyme was not so highly purified as to rule out the contribution of other peptidases, these results suggest that the dental pulp of rats may contain a single enzyme that degrades bradykinin, and the enzyme may be a type of carboxypeptidase, differing from known kininases from other animal sources.

Amino Acids↗