Biomedical subjects

S Ueda

Publications and source records attributed to S Ueda.

At least 937 records · Page 52Linked to original sources

PubMed1984

Exogenous ATP induces electrical membrane responses in fibroblasts.

Mouse fibroblastic L cells responded to exogenous ATP (greater than or equal to 0.2 mM) with a transient hyperpolarization due to increased membrane permeability to K+. By contrast, intracellular injection of ATP (up to about 3 mM) produced no noticeable effects on the membrane potential. The effects of a non-hydrolysable analogue of ATP (AMP-PNP) were similar to those of ATP. After successive applications of ATP, the cell membrane became virtually unresponsive (desensitized). Extracellular ADP was also effective, but AMP or adenosine was not. Antazoline suppressed the ATP response. Thus, exogenous ATP and ADP appear to stimulate P2- purinoceptors . Similar responses to ATP (or ADP) were also observed in human normal diploid fibroblasts (Flow 1000 line).

Adenosine Diphosphate↗

PubMed1984

Improved purification and enzymatic properties of three forms of reverse transcriptase from avian myeloblastosis virus.

The purification procedure for quantitative recovery of the three molecular forms, alpha, alpha beta and beta 2 of avian reverse transcriptase (Ueno, A., Ishihama, A. and Toyoshima, K. (1982) J. Biochem. 91, 311-322) was improved with respect to removal of nucleases. The three enzyme forms were prepared from avian myeloblastosis virus by CsCl centrifugation and poly(G)-agarose column chromatography. The alpha- and alpha beta-forms of the enzyme were further purified to near homogeneity by column chromatography on heparin agarose and DNA cellulose, respectively. The three enzyme forms thus purified were equally active in influenza virus RNA-directed synthesis of single-strand cDNA. By contrast, the alpha-form enzyme was more active in the single-strand cDNA-directed synthesis of double-strand DNA than the other two enzyme forms.

Avian Leukosis Virus↗

PubMed1984

Distribution of myosin isozymes in human atrial and ventricular myocardium: comparison in normal and overloaded heart.

We have prepared monoclonal antibodies specific for either atrial or ventricular myosin and defined the isomyosin composition of myocardium in normal and overloaded human hearts. In the atrial myocardium, normal isozymic pattern was V1 dominant which converted to being V3 dominant in an overloaded condition. In contrast, normal isomyosin pattern of the ventricular myocardium was exclusively V3 dominant, and only a small change in the proportion of isomyosin was observed in an overloaded condition. From this, we conclude that isozymic changes in cardiac myosin could occur in the human heart to meet increased work induced by cardiac overload. However, the physiological importance of these isomyosin redistributions in human myocardium seems to be much greater in the atrium than in the ventricle, since larger amounts of V1 isomyosin which could be transformed to V3 isomyosin were present in the atrial myocardium.

Adenosine Triphosphatases↗

PubMed1984

Induction of acute myoclonic encephalopathy in hamsters by subacute sclerosing panencephalitis virus.

Myoclonus is a characteristic neurological sign of subacute sclerosing panencephalitis (SSPE). Attempts were made to induce myoclonus in a large proportion of hamsters with a cell-associated strain of SSPE virus (the Biken strain) and thereby to establish an experimental model for study of the mechanism of development of this condition. When injected intracerebrally, Biken virus induced myoclonus within two to 14 days in 84% of the three- to nine-week-old hamsters tested. Electroencephalographic traces showed a periodic and synchronous discharge consisting of high-voltage slow waves and spikes that appeared coincidentally with myoclonus. Neurons in the cortex and thalamus of the affected animals had severely degenerated cytoplasm. Inflammatory changes, such as perivascular cuffing or infiltration of mononuclear cells, were not detected. Staining with immunoperoxidase revealed measles viral antigens in the cytoplasm and dendrites of the affected neurons. SSPE virus with the same properties as the parent virus was recovered from brain cells of sick animals by cocultivation with Vero cells.

Animals↗

PubMed1984

Characterization of N-glycolyneuraminic acid-containing glycosphingolipids from a Marek's disease lymphoma-derived chicken cell line, MSB1, as tumor-associated heterophile Hanganutziu-Deicher antigens.

Heterophile, Hanganutziu-Deicher (HD) antigen-active N-glycolylneuraminic acid-containing glycosphingolipids (GSLs) were detected as tumor-associated foreign antigens of a Marek's disease lymphoma-derived cell line, MSB1, by enzyme-immunoassay with chicken antibody against N-glycolylneuraminyl-lactosylceramide (anti-NeuGc-LacCer). At least three species of HD antigen-active GSLs were detected by two-dimensional thin-layer chromatography (TLC) combined with enzyme-immunoassay. The reactivities of the GSLs with anti-NeuGc-LacCer, their behaviors on two-dimensional TLC and the results of an endo-beta-galactosidase digestion study indicated that these three GSLs were NeuGc-LacCer (NeuGc alpha 2-2Gal beta 1-4Glc-Cer), NeuGc-nLcOse4Cer (NeuGc alpha 2-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer) and NeuGc-nLcOse6Cer (NeuGc alpha 2-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer).

Animals↗

PubMed1984

Sensitive enzyme-immunostaining and densitometric determination on thin-layer chromatography of N-glycolylneuraminic acid-containing glycosphingolipids, Hanganutziu-Deicher antigens.

A sensitive enzyme-immunochemical staining method was developed for detection of N-glycolylneuraminic acid (NeuGc)-containing glycosphingolipids (GSLs) on silica gel thin-layer chromatography. The procedure consists of immune reaction among NeuGc-containing GSLs, affinity-purified chicken anti-NeuGc-LacCer and horseradish peroxidase-conjugated rabbit anti-chicken IgG, and the peroxidase reaction using 4-chloro-1-naphthol as a chromogenic substrate. Quantitative determination was achieved by direct densitometric scanning of the enzyme-immunostained spots on the chromatogram. As little as 0.5 pmol of NeuGc-LacCer, NeuGc-nLcOse4Cer, and NeuGc-nLcOse6Cer (0.64-1.0 ng) could be detected with a good signal-to-noise ratio. A semi-linear detector response was observed up to 50 pmol of each GSL. This procedure can be applied easily to other glycolipid antigen systems.

Antigens, Heterophile↗

PubMed1984

Processing of glycoprotein gB related to neutralization of Marek's disease virus and herpesvirus of turkeys.

The glycoprotein gB related to neutralization of Marek's disease virus (MDV) and herpesvirus of turkeys (HVT) is composed of several glycosylated polypeptides, which were immunoprecipitated with monoclonal antibodies and rabbit antiserum cross-reactive to MDV-gB and HVT-gB, and analyzed by SDS-polyacrylamide gel electrophoresis. The present pulse-chase experiments showed that the precursor forms of MDV- and HVT-gB were glycoproteins with molecular weights of 110K to 115K (gp115/110) and 115K (gp115), respectively. These precursor forms were processed to smaller gB's (gp63 and gp50 for MDV; gp62, gp52, and gp48 for HVT), at least in part by sialylation. The proteins synthesized in the presence of tunicamycin were two polypeptides of 88K and 83K in MDV-infected cells and a 90K polypeptide in HVT-infected cells, indicating the presence of unglycosylated precursor forms of MDV- and HVT-gB. Differences between virulent and avirulent MDV's and between HVT's with and without protective activity against Marek's disease were observed in the processed forms of MDV- and HVT-gB, especially at the processing step of sialylation.

Animals↗

PubMed1984

Phentolamine-induced rhythmic contractions in bladder detrusor muscle of guinea-pig.

Phentolamine caused a rhythmic contraction concentration-dependently without affecting resting tone in the detrusor muscle. Prazosin, yohimbine, propranolol, noradrenaline, clonidine or isoprenaline failed to cause the rhythmic contraction. These agents did not modify the response to phentolamine suggesting no involvement of alpha- or beta-adrenoceptors in the response to phentolamine. Chlorpheniramine, cimetidine, methysergide, SK&F 83566, atropine, bretylium, hemicholinium or tetrodotoxin failed to inhibit the response to phentolamine. These results suggest that the effect of phentolamine is not mediated through histaminergic, 5-hydroxytryptaminergic, dopaminergic or cholinergic systems, or through transmitter release from nerve endings. Prostaglandin F2 alpha (PGF2 alpha), arachidonic acid but not ATP caused rhythmic contractions which resembled the response to phentolamine. Potassium also caused a contraction with increasing resting tone. Following treatment with nifedipine, or incubation in a Ca2+-free medium, the responses to phentolamine, PGF2 alpha, arachidonic acid and potassium were markedly inhibited or abolished. Cyclo-oxygenase inhibitors such as indomethacin, aspirin and corticosterone inhibited or abolished the responses to phentolamine and arachidonic acid but did not inhibit the response to PGF2 alpha. The results suggest that the phentolamine-induced rhythmic contraction may, at least in part, result from the cyclo-oxygenase metabolite of arachidonic acid in guinea-pig detrusor muscles and a consequent increase in the transmembrane Ca2+-influx.

Animals↗

PubMed1984

Electrical membrane responses to secretagogues in parietal cells of the rat gastric mucosa in culture.

Fragments of the gastric fundus of 6-8-day-old rats were maintained in tissue culture. From the explant, adhered to a plastic substrate, epithelial cells migrated and developed to form a monolayer colony. Histological and histochemical studies as well as indirect immunofluorescence studies using anti-parietal cell antibodies testified to the presence of parietal cells in the monolayer during the first week. These parietal cells were distinguished by their vesicular cytoplasmic structures using phase-contrast or differential interference-contrast microscopy. Acridine Orange, an optical probe of H+ accumulation, was taken up preferentially by these parietal cells, exhibiting orange fluorescence within the cells on the third day of culture, in response to stimulation with gastrin, histamine and carbachol. The resting potential of these cultured parietal cells was about -20 mV. On day 2-4 of culture, the cell membrane became hyperpolarized (up to -30 to -40 mV) in response to gastrin, carbachol or histamine in the presence of isobutylmethyl-xanthine (IMX). During hyperpolarization, the membrane resistances decreased significantly. The amplitude and the polarity of secretagogue-induced responses were found to be dependent on the extracellular concentration of K+ (but not Na+ and Cl-). The carbachol-induced responses were inhibited by atropine but not curare. The responses induced by histamine plus IMX were blocked by cimetidine but not pyrilamine. Neither atropine nor cimetidine affected the gastrin-evoked responses. It is concluded that rat parietal cells have separate receptors for acetylcholine (muscarinic), gastrin and histamine (H2), and that an increase in the membrane permeability to K+ is closely associated with the responses of these receptors under these in vitro conditions.

Animals↗

PubMed1984

Identification with monoclonal antibodies of glycoproteins of Marek's disease virus and herpesvirus of turkeys related to virus neutralization.

By use of monoclonal antibodies cross-reactive with Marek's disease virus and herpesvirus of turkeys, three glycoproteins (for Marek's disease virus, gp115/110, gp63, and gp50; for herpesvirus of turkeys, gp115, gp62 and gp52) related to virus neutralization were identified. Immunization of chickens or rabbits with these glycoproteins purified by affinity chromatography resulted in production of neutralizing antibodies.

Animals↗

PubMed1984

Actions of some autonomic drugs on spontaneous contractions of isolated dog ureter.

Effects of some autonomic drugs on the isolated dog ureteral preparations showing spontaneous contractions were investigated quantitatively. Noradrenaline, adrenaline and phenylephrine produced increases in frequency and tension of the contractions which were reversed to decreases or depressed by phentolamine. Isoproterenol abolished the spontaneous contractions. Acetylcholine did not significantly change frequency and tension of the contractions. The results indicate that ureteral spontaneous contractions may be enhanced through an activation of alpha-adrenoceptors and be attenuated through an activation of beta-adrenoceptors. However, acetylcholine will not display an important role on the ureteral contractions.

Animals↗

PubMed1984

Isozymic changes in myosin of human atrial myocardium induced by overload. Immunohistochemical study using monoclonal antibodies.

An immunohistochemical study using monoclonal antibodies specific for the heavy chains of either human atrial (HC alpha) or ventricular (HC beta) myosin was performed to clarify the distribution of each isozyme in normal as well as pressure-overloaded human hearts. In normal human ventricles, all muscle fibers were stained by a monoclonal antibody (HMC14) specific for HC beta, whereas a small number of fibers reacted with a monoclonal antibody (CMA19) specific for HC alpha. In contrast, in normal human atria, almost all muscle fibers were stained by CMA19, and a relatively larger number of muscle fibers also reacted with HMC14. Furthermore, in pressure-overloaded atria, muscle fibers reactive with HMC14 were strikingly increased while those reactive with CMA19 showed a corresponding decrease. The extent of this isozymic redistribution was in good correlation with atrial pressure. These results not only confirmed the existence of isoforms of myosin heavy chain in human hearts, but also demonstrated that redistribution of iso-myosins could occur as an adaptation to pressure overload.

Animals↗

PubMed1984

An assessment of gastric ulcers in vivo: enhancement of urinary recovery after oral administration of phenolsulfonphthalein in rats.

The permeability of gastric wall barrier to phenolsulfonphthalein (phenol red), a poorly absorbed drug, was examined as an index of an assessment of gastric mucosal damages in vivo. The urinary recovery after oral administration of phenol red and the ulcer index of the stomach were significantly increased in rats subjected to restraint and water immersion stress. Gastric absorption of phenol red, examined by means of in situ loop technique, was increased significantly in stressed rats. However, the urinary recovery of the dye after intravenous administration did not change in ulcerated rats compared with the control. These findings suggest that the increase in the urinary recovery of phenol red is due to the increased gastric absorption. The healing period of 12 d was enough to restore to control levels both the ulcer index and the urinary recovery of the dye. Both indices remained nearly at control level by the pretreatment with atropine sulfate. Good correlation between extent of gastric damage and urinary excretion of phenol red was obtained within single groups of animals. This method may be utilized as a simple and noninvasive screening test for an assessment of gastric mucosal damages in vivo.

Absorption↗

PubMed1984

Serotonin-containing neurons in the rat and cat brain, especially in the hypothalamus, following monoamine oxidase inhibitor pretreatment: an immunohistochemical study using anti-serotonin antiserum.

The presence of serotonin-containing neurons in the hypothalamus of the rat and cat was studied by immunohistochemistry. In the rat, a group of serotonin-immunoreactive neurons was observed in the nucleus dorsomedialis hypothalami following nialamide pretreatment at a high dosage (over 300 mg/kg). In the cat, serotonin-immunoreactive neurons were sparsely distributed in the ventral part of the middle to the caudal lateral hypothalamic area after high dosage (500 mg/kg) nialamide pretreatment.

Animals↗

PubMed1984