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H Sano

Publications and source records attributed to H Sano.

At least 685 records · Page 38Linked to original sources
PubMed1980

Identification of 5-methylcytosine in DNA fragments immobilized on nitrocellulose paper.

A method to identify 5-methylcytosine (m5Cyt) in DNA immobilized on nitrocellulose paper by using antibody against m5Cyt raised in rabbits is described. Immobilized restriction fragments of DNA are incubated first with purified antibody against m5Cyt and then with goat anti-rabbit IgG labeled with 125I. Restriction fragments containing m5Cyt are visualized by autoradiography. By using this method, a heavily methylated fragment of about 1700 base pairs was identified in nuclear DNA fom Chinese hamster cells, the methylation pattern of calf thymus satellite I DNA was examined, and chloroplast DNAs that were extracted from various stage of the Chlamydomonas life cycle were compared. Little if any methylation was detected in chloroplast DNA from vegetative cells or from male gametes, whereas homologous DNAs from female gametes and from zygotes were heavily methylated. The sensitivity of the method was examined with calf thymus satellite I DNA (which contains approximately 40 m5Cyt residues per repeat unit of 1400 base pairs) and with phi X174 virion DNA (which contains a single m5Cyt per molecule). The presence of m5Cyt was detected with as little as 40 ng of phi X174 DNA containing 0.02 pmol of m5Cyt and with 100 ng of satellite DNA containing about 0.5 pmol of m5Cyt. Thus, the method makes possible the identification of individual methylated sites in purified DNAs in the size range of single genes.

5-Methylcytosine↗
PubMed1980

Deoxyribonucleic acid methyltransferase from the eukaryote, Chlamydomonas reinhardi.

DNA methyltransferase was purified 310-fold from a green alga, Chlamydomonas reinhardi vegetative cells. The native enzyme of molecular weight 55 000--58 000 catalyzed the transfer of methyl groups from S-adenosylmethionine to the 5 position of cytosine in DNA. Native DNA accepted methyl groups 10-fold more than did denatured DNA. The sequence specificity analysis of methylated deoxycytidine in vitro revealed that the enzyme introduces methyl groups preferentially into sequences containing 5'd(T-mC-R)3'. Kinetic analysis of the reaction indicated that the enzyme obeys a random sequential mechanism. The extent of saturation with methyl groups depends upon the species from which the DNA was obtained. Kinetic analysis of the reaction catalyzed by RNA polymerase II has indicated that DNA methylation decreases the rate of initiation of RNA synthesis, but does not affect the rate of RNA chain elongation.

Base Sequence↗
PubMed1979

Messenger RNA of the large subunit of ribulose-1,5-bisphosphate carboxylase from Chlamydomonas reinhardi. Isolation and properties.

Polysomes specifically synthesizing the large subunit of ribulose-1,5-bisphosphate carboxylase were isolated from Chlamydomonas reinhardi cells by the indirect immunoprecipitation method. Electrophoretic analysis showed that the immunoprecipitated polysomes were of chloroplast origin. The mRNA coding for the large subunit which was purified from immunoprecipitated polysomes migrated at the 19-S position on sucrose density gradients, and its molecular weight was estimated to be 7.3 x 10(5) by acid-urea/agarose gel electrophoresis. The mRNA was translated in vivo with a cell-free protein-synthesizing system derived from Escherichia coli to give full-length large-subunit polypeptides.

Carboxy-Lyases↗
PubMed1979

An experimental study on histamine H2-receptor antagonist on calcium, gastrin and histamine induced gastric acid secretion in rat.

The suppressive effect of histamine H2-receptor antagonist, cimetidine, on gastric secretion was investigated in Ghosh-Schild rat. The study above was done in basal state under infusing normal saline (1 ml/h) and stimulated state by histamine-di-chloride (3.5 mg/kg-h), tetragastrin (50 mcg/kg-h) or calcium chloride (4 mg/kg-h). Dose related increase of cimetidine (1.7, 3.5, 7.0 and 14.0 mg/kg-h) were observed and correlated with the degree of inhibition of acid secretion. Cimetidine had a potent inhibitory activity on either basal and stimulated acid output by the agents above. Basal acid secretion was completely abolished by 3.5 mg/kg-h of cimetidine to the level of anacidity. The degree of inhibition by the same dose of cimetidine was different among the agents used as stimulant on acid secretion and it followed in the order of calcium, gastrin and histamine subsequently. This study indicated that histamine H2-receptor participated the gastric secretion induced by either gastrin or calcium other than histamine itself. This fact indicated the important role of endogenous histamine in gastric secretion induced by calcium and gastrin.

Animals↗
PubMed1979

RNase levels in golden hamster with DHPN induced pancreatic cancer.

Twenty Syrian golden hamsters recieved weekly injections of pancreatic cancer inducing DHPN. Their Poly (U) specific serum RNase levels were significantly elevated when compared to the control levels. Following salt fractionation, Poly (U) specific activity was present in both the 40% and 50% salt saturated fractions. Tissue assays showed that Poly (U) specific RNase was present in both pancreas and liver tissue extract, although the liver tissue RNase had a different pH maximum than that of the serum RNase.

Adenocarcinoma↗
PubMed1979

Effects of the host matrix on the 57Fe-species produced through EC-decay in 57Co-labelled tris(phenanthroline) cobalt (II) perchlorate.

Emission Mössbauer spectroscopic studies of 57Co-labelled [Co(phen)3]clO4)2 in host matrices [M(II)(phen)3](ClO4)2(M=Co, Fe, and Ni) indicate that the relative intensities of the anomalous species produced through the EC-decay depend on the kind of the host matrix. The largest intensity was observed with the cobalt (II) matrix, and the smallest with the iron (II) matrix. Emission spectra of 57Co-labelled [Co(2-CH3-phen)3](ClO4)2 2H2O in the matrix of [Fe(2-CH3-phen)3](ClO4)2 were also studied. The high-spin state (5T2) was predominantly observed at 4.2 K in the emission spectrum, while the low-spin state (1A1) was mainly observed in the absorption spectrum at 78 K. The results are discussed in terms of the stability of the lattice.

Cobalt Radioisotopes↗
PubMed1978

CT in evaluation of the circle of Willis.

The method of visualizing the circle of Willis intentionally on contrast-enhanced CT scan was studied. The incidence of circle of Willis in our series was 86%. Only mild side effects were observed, in 7.5% of cases. CT of 60 proven cerebral aneurysms were reviewed and aneurysm was detected in 57%. This method has the potential to be a noninvasive screening procedure for evaluation of suspected cerebral aneurysm, as well as evaluation of marked arteriosclerosis, occlusion of major arteries, and mass effect of parasellar tumors.

Cerebral Angiography↗
PubMed1977

[Effects of several catecholamine-related drugs on aggressive behavior, brain noradrenaline content and tyramine uptake by isolated mice].

Such effects were studied in male albino mice maintained under isolation circumstances for 7 weeks in order to induce aggressiveness. L-DOPA (25 mg/kg) was given concomitantly with DDC (75 mg/kg) or reserpine (0.1 mg/kg), or each was administered signly and intraperitoneally to subjects twice weekly. Two peaks on the aggressive degree were observed at the 3rd-4th and 6th weeks, respectively. At the first peak, mice treated with L-DOPA and/or reserpine demonstrated aggressive behavior to a higher degree than control mice but at the second peak, to a lower degree. Mice treated with L-DOPA and DDC showed the highest degree at the second peak. Tyramine uptake in the brain measured at the 6th week was enhanced in mice treated with combinations of L-DOPA with reserpine or DDC. Noradrenaline content in the brain was lowered in mice treated with L-DOPA and/or reserpine, in comparison with each control value; It is thus concluded that catecholamine-related drugs influence the degree of enhancement of aggressiveness in modes which vary depending on the form of action of each drug.

Aggression↗