[Relationship between an aged mother and grown-up son left to themselves].
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Adult↗
Biomedical subjects
Y Tonegawa
Publications and source records attributed to Y Tonegawa.
Amino acid sequence of exogastrula-inducing peptide C from the sea urchin, Anthocidaris crassispina.
The complete amino acid sequence of exogastrula-inducing peptide C from embryos of the sea urchin, Anthocidaris crassispina has been determined by analysis of the amino acid sequences in the S-pyridylethylated peptide C and the peptides generated after digestion of the peptide C with arginyl endopeptidase. Exogastrula-inducing peptide C was composed of 58 amino acid residues and its molecular weight was calculated to be 6464. The sequence was DTKGGCERATNNCNGHGDCVQGRWGQYYCKCTLPYRVGGSESSCYMPKDKEEDVEIET.
Amino Acid Sequence↗
The exogastrula-inducing peptides in embryos of the sea urchin, Anthocidaris crassispina--isolation and determination of the primary structure.
Four exogastrula-inducing peptides, A, B, C, and D have been isolated from the homogenates of embryos of the sea urchin, Anthocidaris crassispina, with successive chromatographic fractionations. The complete amino acid sequences of the peptides A and D were determined by analysis of the peptides generated by their digestion with lysyl endopeptidase. They were composed of 52 and 53 amino acid residues, and their molecular weights were calculated to be 5754 and 5737, respectively. The sequences of peptides A and D were DSVYQCNRDTNSCDGFGKCEKSTFGRTTGQYICNCDDGYRNNAYGGCSPRTE, and DTVARCERDTKNCDGHGTCQLSTFGRRTGQYICFCDAGYRKPNSYGGCSPSSA, respectively. The biological significance of the exogastrula-inducing peptides was discussed.
Amino Acid Sequence↗
Specific binding of lectins with the nucleus of the sea urchin embryo and changes in the lectin affinity of the embryonic chromatin during the course of development.
(1) Embryonic cells of sea urchins were made permeable by treating them with glycerol solution for the purpose of allowing penetration of macromolecules into the cell. With the use of such permeabilized cells, several kinds of fluorescent dye-labeled lectins were introduced into the cell, and it was found that some lectins showed notable affinity with the nucleus as compared with cytoplasmic structures. (2) Isolated chromatin was incubated with several kinds of fluorescent dye-labeled lectins in vitro, and the amount of lectins bound with the chromatin was measured by fluorometry. By means of this method, the lectin-binding capacity of chromatin was estimated and compared at various stages of development. It was found that lectins could be classified into three groups according to the mode of binding with the chromatin: (a) Extent of binding increased notably at the gastrula stage (Con A and RCA-120); (b) extent of binding showed a temporary decrease at the gastrula stage (TTA); and (c) very low level of binding was maintained throughout all stages, and no particular change was observed at any stage of development (WGA, SBA, and UEA-I). (3) These facts seem to suggest that lectin-binding components are contained in sea urchin chromatin, and that drastic changes occur in these components of chromatin at the stage of gastrulation. It was proposed that the lectin-binding components such as proteoglycans and glycoproteins may play regulatory roles in embryonic chromatin at early stages of development.
Age Factors↗
Effects of neonatal administration of monosodium glutamate on plasma growth hormone (GH) response to GH-releasing factor in adult male and female rats.
Female and male rats were treated with monosodium glutamate (MSG; 4 mg/g b. wt.) as neonates and the capability of the pituitary gland to secrete growth hormone (GH) in response to an intravenous injection of human GH-releasing factor (GRF) was evaluated under pentobarbital anesthesia on 109 days of life. Immunoreactive GRF content in the pituitary stalk-median eminence tissue in MSG-treated rats was less than 20% of that of control. A significant dose-dependent plasma GH response was observed after the administration of two doses of human GRF (0.25 and 1 microgram/kg b. wt., i.v.) in both control and MSG-treated rats. The responses between MSG-treated and control rats were comparable in female rats, but they were significantly reduced in male MSG-treated rats. These results show that the pituitary's responsiveness to exogenous GRF is well preserved in MSG-treated rats despite prolonged and severe depletion of endogenous GRF and there exists a sex difference in the effect of MSG on GH secretion elicited by GRF.
Animals↗
A Ca2+-binding protein and an endogenous lectin from sea urchin embryos.
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1-Carboxyglutamic Acid↗
Effect of hypothalamic ventromedial lesions on plasma growth hormone response to growth hormone-releasing factor in rats.
The effect of ventromedial-arcuate (VMH-ARC) nuclei lesions on plasma growth hormone (GH) response to human growth hormone-releasing factor (GRF, 1 microgram/kg b.wt., i.v.) was studied in conscious rats after they had received chlorpromazine (CPZ) or CPZ plus antiserum against somatostatin (ASS). When rats were pretreated with CPZ alone, there was no difference in basal plasma GH level between VMH-ARC lesioned rats and controls. The magnitude of plasma GH response to GRF in 5 out of 6 VMH-ARC lesioned rats exceeded that of controls. When the same observation was repeated using the same rats after they had received ASS and CPZ, basal plasma GH levels of controls were significantly higher than those of VMH-ARC lesioned rats, and the magnitude of the plasma GH response to GRF was augmented in both groups of rats. The plasma GH response to GRF was comparable between two groups, though the peak plasma GH response to GRF was slightly but significantly lower in VMH-ARC lesioned rats as compared to controls. Pituitary GH content was reduced significantly in VMH-ARC lesioned rats as compared to controls. The results demonstrate that the pituitary responsiveness to GRF does not appear to be altered significantly in rats bearing bilateral VMH-ARC lesions. In addition, the placement of electrolytic lesions in VMH-ARC regions causes reduced SS secretion into the hypophyseal portal vessels and leads to an augmentation of plasma GH response to GRF.
Animals↗
Effect of dopamine, bombesin and cysteamine hydrochloride on plasma growth hormone response to synthetic growth hormone-releasing factor in rats.
In urethane anesthetized rats, an intracerebroventricular (icv) injection of 2 micrograms bombesin 5 min prior to the administration of synthetic human growth hormone-releasing factor (GRF) (1 microgram/kg, iv) inhibited plasma growth hormone (GH) response, while cysteamine hydrochloride (90 mg/kg, sc) administered 150 min beforehand depleted immunoreactive somatostatin content in the pituitary-stalk median eminence and consequently potentiated the response to GRF. Under the same experimental conditions, central injection of 1.89 micrograms (10(-8)M) dopamine hydrochloride or iv administration of L-DOPA (10 mg/kg) did not influence the subsequent plasma GH response to GRF. Results suggest indirectly that bombesin and cysteamine, but not dopamine, predominantly modulate somatostatin release from the hypothalamus.
Animals↗
Presence of corticotropin-releasing factor-like immunoreactivity in human tumors.
Corticotropin-releasing factor (CRF)-like immunoreactivity was measured by radioimmunoassay in human organs and tumors associated with and without ectopic adrenocorticotropic hormone (ACTH) syndrome. It was found to be distributed widely in the stomach, pancreas, adrenal gland, and various tumors (e.g., medullary thyroid carcinoma, small cell carcinoma of the lung, pheochromocytoma, and adenocarcinoma of the gastrointestinal tract and pancreas) in a concentration less than one tenth of that of the hypothalamus. Dilution curves of CRF-like immunoreactivity in tissue extracts paralleled that of synthetic rat (human) CRF. Sephadex G-50 gel filtration showed that a major CRF-like immunoreactivity in tissue extracts coeluted with synthetic rat (human) CRF. Results suggest that a material(s) closely related immunologically to CRF is present widely in normal and tumor tissues outside of the central nervous system.
ACTH Syndrome, Ectopic↗
Plasma growth hormone response to human growth hormone releasing factor in rats administered with chlorpromazine and antiserum against somatostatin. Effects of hypo- and hyperthyroidism.
The effect of hypo- and hyperthyroidism on the plasma growth hormone (GH) response to synthetic human growth hormone releasing factor (GRF) was determined in conscious, freely moving rats pretreated with chlorpromazine and antiserum against somatostatin. Chlorpromazine plus somatostatin antiserum pretreated rats gave consistent response to GRF which was not observed in untreated rats. Chlorpromazine alone has no effect on GH secretion induced by GRF in rat pituitary monolayer culture. In rats made hypothyroid by thyroidectomy, both basal and peak plasma GH responses to a small (0.25 microgram/kg bw) and a moderate dose of GRF (1 microgram/kg bw) were significantly reduced as compared to controls. In rats made hyperthyroid by the administration of thyroxine, basal and peak plasma GH responses to a small but not to a moderate dose of GRF were significantly reduced as compared to controls. A reduced plasma GH response to a small dose of GRF was observed 8 days after the cessation of thyroxine administration. The pituitary GH reserve was markedly reduced in hypothyroid but not in hyperthyroid rats as compared to their respective controls. These results indicate that plasma GH response to GRF is reduced both in hypo- and hyperthyroidism. The mechanism involved in the phenomenon appears to be different between the two conditions.
Animals↗
[Effect of hypo- and hyperthyroidism, and hypothalamic ventromedial lesions on the plasma growth hormone response to human growth hormone-releasing factor in rats].
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Animals↗
Production of antisera to growth hormone-releasing factor: usefulness in radioimmunoassay and passive immunization.
We have produced two antisera (R-1 & R-2) to human growth hormone-releasing factor (GRF) [1-44] NH2. Both antisera can be used for human GRF radioimmunoassay (RIA) at a final dilution of 1:50000. The antiserum R-2 was specific for the C-terminal amidated sequence of human GRF-44 and selectively recognized GRF [1-44] NH2 but not GRF [1-44] OH or GRF [1-40] OH. The antiserum R-1 also significantly bound 125I-rat GRF [1-43] OH at a final dilution of 1:5000 and enabled us to establish RIA for rat GRF. In both RIA systems, intra- and inter-assay coefficients of variation at 50% inhibition were 8 and 12%, respectively. A median effective dose was 90-120 pg in human GRF RIA and 250-300 pg in rat GRF RIA. Utilizing the RIA, we demonstrated that the hypothalamic GRF content in rats which received monosodium glutamate during the neonatal period was less than 20% of that of controls. However, the hypothalamic GRF content was not altered in rats made hypothyroid by methimazole administration, another condition known to greatly impair GH secretion. An iv administration of the antiserum R-1 significantly suppressed GH release following the injection of antisomatostatin serum. Thus, these antisera can be a useful tool in examining the physiological and/or pathophysiological roles of GRF in human and rat.
Animals↗
Multiplicity of molecules carrying blood-group-I antigen on erythrocyte membranes.
A human serum containing a monoclonal anti-(blood-group I) antibody was used to investigate the distribution of blood-group-I antigen on erythrocyte membrane components. Sodium dodecyl sulphate/polyacrylamide-gel-electrophoresis profiles of immuneprecipitates by using 3H-labelled (by the galactose oxidase/NaB3H4 method) and 125I-labelled solubilized stroma were compared. Different radioactive profiles were revealed by the two radiolabelling methods. In the immunoprecipitates the predominant 125I radioactivity within the gel had the electrophoretic mobility of Band-3 protein (apparent mol.wt. 90 000--100 000), whereas the 3H radioactivity revealed a diffusely migrating component(s) (apparent mol.wt. range 40 000--70 000) in addition to radioactivity compatible with glycolipids at the dye front. The diffusely migrating 3H-labelled component was shown to have a similar electrophoretic mobility to a subpopulation of erythrocyte poly(glycosyl)ceramides with blood-group-I activity.
Blood Group Antigens↗
"Ganglioprotein and globoprotein": the glycoproteins reacting with anti-ganglioside and anti-globoside antibodies and the ganglioprotein change associated with transformation.
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Animals↗
Hyperthermic action of somatostatin-28.
An intracisternal injection of somatostatin-28 produced hyperthermia in rats at cold, thermoneutral, warm ambient temperatures. The hyperthermic response to somatostatin-28 was not prevented by pretreatment of rats with the following agents: alpha-methylparatyrosine, phenoxybenzamine, propranolol, sulpiride, atropine, methysergide or naloxone. Somatostatin-28 prevented hypothermia induced by bombesin and gamma-MSH when it was administered simultaneously, but it left the hyperthermic response to TRH intact. The results indicate that somatostatin-28 produces hyperthermia by elevating a "set point" or regulated level of temperature. Under the conditions tested, the hyperthermic response to somatostatin-28 does not appear to be dependent on muscarinic cholinergic, serotonergic, alpha- or beta-adrenergic, dopaminergic or endogenous opiate system.
Animals↗
Interferon-alpha therapy for chronic active Epstein-Barr virus infection: potential effect on the development of T-lymphoproliferative disease.
PURPOSE: A patient with aggressive chronic active Epstein-Barr virus (CAEBV) infection is described whose disease activity subsided after interferon (IFN)-alpha therapy. PATIENT AND METHODS: The patient had intermittent fever, cytopenia, liver dysfunction, hepatosplenomegaly, abnormal titers of EBV-associated antibodies, and positive EBV genomes. RESULTS: Despite repeated trials of the antiviral agents prednisolone and gamma-globulin, his condition deteriorated. The administration of IFN-alpha (1 x 10(5) U/kg subcutaneously 3 times per week) led to a dramatic clinical improvement. During the IFN-alpha therapy, the rearrangement bands of T-cell antigen receptor genes disappeared assessed by Southern blotting with a decrease in the number of activated T cells, although the EBV-genome remained evident. CONCLUSIONS: These observations suggest that IFN-alpha is useful in managing CAEBV, possibly restraining the clonal development of T-lymphoproliferative disease (LPD) and EBV-associated B-LPD, although it does not eradicate the proliferation of EBV.
Antiviral Agents↗