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Biomedical subjects

M Ono

Publications and source records attributed to M Ono.

At least 901 records · Page 50Linked to original sources
PubMed1980

Untranslated immunoglobulin kappa light chain mRNA in a lambda light chain-producing mouse myeloma, MOPC104E.

Fourteen clones were isolated in culture from a mouse myeloma, MOPC104E. All clones had kappa and lambda types of light chain mRNAs in approximately equimolar quantity as assayed by hybridization with specific complementary DNA (cDNA). However, the myeloma produces and secretes only lambda-type light chain protein. Both kappa- and lambda-type mRNAs in these clones were indistinguishable from kappa- and lambda-type mRNAs of other myelomas with respect to (a) adsorption to oligo-(dT) cellulose, (b) molecular size (12.6 S), and (c) thermal stability of the hybrids formed with corresponding cDNA. The kappa chain mRNA of MOPC104E cells, however, was translated very inefficiently both in vivo and in vitro, whereas the lambda chain mRNA was translated efficiently. These results indicate that each cell of MOPC104E myeloma synthesizes a crippled kappa chain mRNA in addition to a normal lambda chain mRNA.

Animals↗
PubMed1980

Effects of captopril (SQ 14, 225) on the renin-angiotensin-aldosterone system in normal rats.

High doses of captopril (SQ 14, 225) (120-160 mg/kg/day) were administered orally to normal rats, and the effects on the renin-angiotensin-aldosterone system were observed. Plasma angiotensin converting enzyme (ACE) activity was elevated significantly on the 3rd, 7th and 30th days of captopril administration. ACE activity in the lung and the kidney was significantly decreased on the 1st day then gradually increased, becoming significantly higher than that of controls by the 30th day. Plasma renin activity (PRA) was significantly elevated on the 1st day and remained at a high level until the 30th day. Renal renin content was found to be significantly lower on the 1st and 3rd days. Plasma aldosterone concentration was not affected by captopril treatment, whereas serum potassium concentration was found to be significantly lower on the 1st, 3rd and 30th days. It is suggested that besides its inhibitory action on ACE, captopril has a direct or indirect stimulating action on ACE production as well as on renin release.

Aldosterone↗
PubMed1980

alpha-Lactalbumin-casein induction in virgin mouse mammary explants: dose-dependent differential action of cortisol.

The interplay of insulin, cortisol, and prolactin induces synthesis of casein and alpha-lactalbumin in cultured mammary explants from mature virgin mice. A striking difference has been found between the optimal concentrations of cortisol required for maximal induction of the two milk proteins in vitro: 3 x 10(-8) molar for alpha-lactalbumin and 3 x 10(-6) molar for casein. Moreover, 10(-7) to 10(-5) molar cortisol caused progressive inhibition of alpha-lactalbumin accumulation. Such differential actions of cortisol may partly account for the asynchronous synthesis of the two proteins during pregnancy.

Animals↗
PubMed1980

Sequence organization of cloned intracisternal A particle genes.

Seven recombinant DNA clones containing mouse intracisternal A particle genes were isolated and analyzed by restriction enzyme digestion, Southern blot analysis and heteroduplex mapping. The sequence organization of the individual genes was found to differ, with one end of the gene region being most variable, while a central segment of 1.8 kb was missing from two of the clones. A third region, common to all the clones and containing the 3' end of the gene, is present in about 1800 copies per haploid genome, but the central portion is found in only 650 copies. The same reiteration frequency is found in both myeloma tumor and mouse liver DNA. The most abundant intracisternal A particle RNA in two different myeloma lines was found to be 3.5 kb, and RNA/DNA hybrids show that the RNA is homologous to all but a small internal segment of one of the clones.

Animals↗
PubMed1980

Osseous changes and abnormalities of mineral metabolism in rats with glycopeptide-induced nephritis.

A laboratory model of renal osteodystrophy was developed in rats by a single injection of glycopeptide isolated from renal cortical tissues of rats according to the method used by Shibata et al. to induce glomerulonephritis. Approximately 60-70 days after injection, severe proteinuria appeared and continued for at least 170 days at a rate of more than 1 g/day. Morphological changes in the kidney were typical of chronic glomerulonephritis. The plasma calcium concentration was lowered transiently by the 96th day after injection, but was restored to the normal range thereafter. Plasma parathyroid hormone levels, however, continued to rise in parallel with the degree of proteinuria. Marked secondary hyperparathyroidism was induced which led to severe bone atrophy. Histological examinations showed a marked increase of resorbing cavities, with a quantitatively larger number of osteoclasts in cortical bone tissues compared with the control animals. No spontaneous remission was observed. It is emphasized that all of the biochemical and morphological changes reported here were induced by a single injection of homologous renal glycopeptide, and they were highly reproducible.

Animals↗
PubMed1980

[99mTc-MAA brain scan and CT in the diagnosis of intracranial diseases (author's transl)].

Brain scan with 99mTc-labelled macroaggregated albumin (MAA brain scan) and computed tomography studies (CT) were performed on 78 patients with intracranial diseases. 99mTc-MAA was injected into right and left carotid artery respectively, at the different time. And then diagnostic evaluation of both techniques were investigated. The MAA brain scan was useful for the detection of ischemic lesion in the early stage after onset of cerebral infarction. It was shown in 29.5% that partial field of anterior cerebral artery was injected through the contralateral artery. In these cases, the MAA brain scan was also useful. In the cases of hemorrhagic lesions, however, the CT was more useful than MAA brain scan. Therefore, the both techniques helped each other in the diagnosis of intracranial diseases.

Adult↗
PubMed1979

[Diagnostic evaluation on cerebral hemisphere scintigraphy using 99mTc-MAA (author's transl)].

Using 99mTc-labeled macroaggregated albumin (99mTc-MAA), we made an examination of the cerebral blood flow distribution with various kinds of cerebrovascular diseases in 151 cases. The particle size of MAA used in this study ranged from 10 to 100 micron. Scan was performed after injection of 3 mCi of 99mTc-MAA into common carotid artery. No side effects were observed except for one case with headache. Distribution of 99mTc-MAA was found to be homogeneous in normal cerebral hemisphere but not in the lesion. Most lesion was shown as nonradioactive area. Meningioma with hypervascularity was represented as hot area. By this method cerebral infarct could be easily represented not only in main artery but also in such a very small artery as hardly detected by CAG. This method is therefore useful for detecting cerebral infarct, sequela of cerebral apoplexy, head injury and others. The dose of 99mTc-MAA used in this method is much lower compared with those of common brain scan, its excretion is speedy, and therefore internal radiation exposure is diminished.

Adult↗
PubMed1979

The cross-resistance of mouse blasticidin S-resistant cell lines to puromycin and sparsomycin, inhibitors of ribosome function.

The antibiotic blasticidin S inhibits peptide-chain elongation in extracts of bacteria and mammalian cells. After spontaneous or nitrosoguanidine mutagenesis, we have isolated 46 blasticidin S-resistant (Blar) cell lines independently from mouse mammary carcinoma cells (FM3a). Among those Blar clones, we studied two clones, a spontaneously induced one (S501) and a nitrosoguanidine mutagenized one (N742) in more detail. The resistant phenotype of these Blar cells is retained without change for at least four months in the absence of the antibiotic. These Blar cells are 10- to 20-fold more resistant to the cytotoxic action of the antibiotic than their parental cells in vivo. Polyuridylate dependent polyphenylalanine synthesis in vitro with S-30 extracts either from N742 or S501 is 10- to 50-fold more resistant to the inhibitory action of blasticidin S compared to the parental FM3a cells. Ribosomes from FM3a and N742 are fractionated into 40-S and 60-S subunits, and polyphenylalanine synthesis by mixing them in various combinations with S-100 fraction from mouse leukemia L5178Y cells indicating that the resistant phenotype of Blar cells is due to the alteration of 60 S ribosomal subunit. We also found that these two Blar cell lines (N742 and S501) show cross-resistance to gougerotin, puromycin and sparsomycin, but not to emetine or cycloheximide. The polyribosomal pattern of FM3a (Blas) and N742 was compared when the cells were incubated with 3 microgram/ml puromycin for 6 h. Puromycin treatment of Blas cells induced accumulation of monosomes and ribosomal subunits, while little if any transition of polyribosomes into monosome and ribosomal subunits appeared in its counterpart N742 treated with the same dose of puromycin.

Animals↗
PubMed1979

Genetic analysis of a mutation affecting ribosomal protein S1 in Escherichia coli.

Ribosomal protein S1 from a newly isolated Escherichia coli mutant has a molecular weight of about 54,000 which is smaller than the wild type S1 (M.W. 65,000). The isoelectric points of the smaller and the wild type S1 species are similar in the gel electrophoresis system of O'Farrell (1975). Genetic analyses by Hfr conjugation and P1 phage transduction indicate that the mutation affecting S1 (rpsA) is located close to the serC gene [20 min on the E. coli genetic map of Bachmann et al. (1976)], with a co-transduction frequency of 61%. The most probable gene order is serC-rpsA-cmlB.

Chromosome Mapping↗
PubMed1979

Mutual homology of mouse immunoglobulin gamma-chain gene sequences.

We have assessed the relative homology of mouse immunoglobulin heavy-chain gene sequence using complementary DNAs (cDNAs) synthesized against gamma-chain mRNAs (gamma 1, gamma 2a, gamma 2b, and gamma 3) purified from mouse myelomas. cDNAs complementary to the gamma-chain mRNAs did not cross-hybridize with the mu- and alpha-chain mRNAs, whereas they cross-hybridized to significant extents (22--66%) with the gamma-chain mRNAs of other subclasses. The heterologous hybrids formed, however, melt at 5--13 degrees C lower temperatures as compared to the homologous hybrids, indicating that significant portions of the heterologous hybrids are mismatched. The rates of the cross-hybridization reactions are 2- to 17-fold slower than those of the homologous hybridization reactions. Therefore, the gamma-chain gene sequences of four subclasses share a part of homology with each other, but they are different enough to be measured separately. Cross-hybridization analysis indicate that the gamma 2a and gamma 2b genes are the most closely related, while the gamma 1 and gamma 3 genes are the least related among the gamma subclass genes.

Animals↗
PubMed1979

Cerebral contribution to the visual suppression of vestibular nystagmus.

Thirty-two patients with cerebral lesions were examined to locate cerebral areas involved in visual suppression. Visual suppression was reduced or abolished when the lesions were in the parietal lobe, especially in the dorsoposterior region. This part of the parietal lobe seems to modify visual suppression of caloric nystagmus that is mediated by the flocculus and nodulus of the cerebellum as well as the pons. In patients with frontal lobe lesions including the parietal lobe, visual suppression was reduced or abolished. Thus, the parietal lobe is important for this visual suppression mechanism.

Adult↗
PubMed1979

No evidence for the existence of a species-specific renin substrate in plasma from normal and bilaterally nephrectomized rats.

Renin substrate in plasma from normal and biolaterally nephrectomized rats was measured using an excess of rat or rabbit renin which had the same pressor activity when directly assayed in the rat. The amounts of angiotensin I generated with an excess of rat renin were similar to those generated with an excess of rabbit renin in plasma from normal and bilaterally nephrectomized rats. Further addition of an excess of homologous renin to the incubation mixture did not generate more angiotensin I from normal and bilaterally nephrectomized rat plasma which had been incubated before with an excess of rabbit renin. The isoelectric focusing profiles of plasma renin substrate from normal and bilaterally nephrectomized rats were almost identical using an excess of either rat or rabbit renin. It is concluded that there is no species-specific renin substrate for homologous renin in normal or bilaterally nephrectomized rats.

Angiotensin I↗