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Biomedical subjects

S Ohno

Publications and source records attributed to S Ohno.

At least 955 records · Page 53Linked to original sources
PubMed1979

Mucosubstances of rabbit granulocytes studied by means of electron-microscopic radioautography and X-ray microanalysis.

Rabbit bone marrow cells have been studied by means of light- and electron-microscopic radioautography and X-ray microanalysis. Carrier free sulfuric acid was used as the radioactive precursor in this experiment. Immature granulocytes showed more active incorporation than mature ones. Silver grains were observed in the Golgi apparatus and granules in three kinds of granulocytes. Electron-microscopically, immature granules showed the incorporation of inorganic sulfate, while mature ones did not. Sulfur was detected in all kinds of granules of the three granulocyte types by X-ray microanalysis. It is concluded that incorporated inorganic sulfur may be utilized for the synthesis of acid glycosaminoglycans and the sulfur detected by X-ray microanalysis may be that contained in the acid glycosaminoglycan. The sulfur detected in the specific granules of the heterophil probably derives from proteins or polypeptides incorporating sulfur containing amino acids.

Animals↗
PubMed1979

Non-random duplication of chromosome 15 in murine T-cell leukemias induced in mice heterozygous for translocation T(14:15)6.

Trisomy of chromosome 15 is a highly regular feature of murine T-cell leukemogenesis. We have studied the chromosomal constitution of 7,12-dimethylbenza(a)anthracene (DMBA)-induced T-cell leukemias in C57BL X CBAT6T6 F1 mice. The CBAT6T6-derived chromosome T(14:15)6 was regularly duplicated whereas the C57BL-derived normal chromosome 15 was only present in one copy. It was concluded that the gene(s) that tend to duplicate in parallel with the neoplastic transformation of the prothymocyte to an overt leukemic cell have a greater chance of duplicating and/or may have a stronger promoting effect on leukemogenesis if stronger promoting effect on leukemogenesis if located on the CBA-derived, structurally rearranged T(14:15)6 than the corresponding genes located on the C57BL-derived normal chromosome 15.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1979

In vitro studies of gonadal organogenesis in the presence and absence of H-Y antigen.

In a very strict sense, the primary (gonadal) sex of mammals is determined not so much by the presence or absence of the Y but the expression or nonexpression of the evolutionary extremely conserved plasma membrane H-Y antigen. The central somatic blastema of embryonic indifferent gonads contains one cell lineage characterized by the possession of S-F differentiation antigen that differentiates into testicular Sertoli cells in the presence of H-Y and into ovarian follicular (granulosa) cells in its absence. This cell lineage appears to play the most critical role in gonadal differentiation. Whether or not testicular Leydig cells and ovarian theca cells are similarly derived from the common cell lineage has not been determined. Nevertheless, if given H-Y antigen, presumptive theca-cell precursors of the fetal ovary acquire hCG (LH?)-receptors-the characteristic of fetal Leydig cells.

Animals↗
PubMed1979

Nonrandom chromosome changes involving the Ig gene-carrying chromosomes 12 and 6 in pristane-induced mouse plasmacytomas.

The karyotypes of pristane-induced mouse plasmacytomas were studied by G banding. Only primary tumors or early passage generations were analyzed. In contrast to murine T cell leukemias that showed a regular trisomy of chromosome 15, all plasmacytomas showed a consistent translocation of the distal part of chromosome 15 to either chromosome 6 [rcpT(6;15)] or 12 [T(12;15)]. The specific breakpoints were at 6C, 15D3/E ro D2/3 and 12F2. Early passage generations often showed a mixed population with two different translocations, suggesting polyclonal origin. Considered together with the known karyotypic features of murine and human lymphomas, these findings support the theory that the nonrandom chromosomal changes in lymphoproliferative malignancies are associated with the type of the target cell, rather than with the etiological agent. Moreover, the involvement of the chromosomes known to carry the heavy chain (12) and the light chain (6) determinants, respectively, raises the question of whether the translocations may be related to the DNA level rearrangements known to occur during the differentiation of normal plasma cells.

Animals↗
PubMed1979

Evidence for antigenic distinctness of the Epstein--Barr virus-determined nuclear antigen and the Herpesvirus papio-determined nuclear antigen.

Previous serological evidence indicated that Epstein--Barr virus-determined nuclear antigen (EBNA) has cross reactive components with the herpesvirus papio-determined nuclear antigen (HUPNA) and, in addition, it has distinct components of its own, not present in HUPNA. In the present study, this hypothesis was studied by absorption experiments. Absorption of anti-EBNA positive human sera with EBNA abolished both anti-EBNA and anti-HUPNA reactivity. Absorption with HUPNA removed all anti-HUPNA reactivity but did not reduce anti-EBNA to any detectable degree, thus confirming the hypothesis.

Animals↗
PubMed1979

Is trisomy cause or consequence of murine T cell leukemia development? Studies on Robertsonian translocation mice.

Trypsin-Giemsa banding studies on T cell leukemias induced in Robertsonian translocation mice by dimethylbenz[a]anthracene and Moloney leukemia virus show a trisomy of chromosome 15 even in cases in which chromosome 15 has undergone centromeric fusion with chromosomes 1, 5, or 6. These results suggest that the duplication of gene(s) located on chromosome 15 is of critical importance for murine T cell leukemia development.

Animals↗
PubMed1979

Detection of a nuclear antigen in Herpesvirus ateles-carrying marmoset lines by the acid-fixed nuclear binding technique.

In vitro binding of a Herpesvirus ateles (HVA)-associated soluble antigen to amphibian erythrocyte nuclei was demonstrated by the acid-fixed nuclear binding technique in combination with anticomplement immunofluorescence. Incubation of concentrated salt-extracted soluble antigens derived from HVA-carrying marmoset lines with methanol/acetic acid-fixed erythrocytes of frogs and salamanders resulted in a brilliant nuclear fluorescence after exposure to a live virus-boostered, anti-HVS-positive squirrel monkey serum. Anti-HVS-negative sera did not stain. The activity of the positive serum could be abosrbed completely with extracts of HVA-carrying cells but not with Epstein-Barr virus-carrying or Herpesvirus papio-carrying cells. The HVA-associated antigen was also present in lytically HVA-infected marmoset kidney cells.

Animals↗
PubMed1979

The identification of human H-Y antigen and testicular transformation induced by its interaction with the receptor site of bovine fetal ovarian cells.

beta 2m(-), HLA (-) Daudi human male Burkitt lymphoma cells excreted a group of protein subunits that shared three distinctive characteristics; their conspicuously longer half-lives compared to more hydrophilic Daudi excreted proteins, their tendency to form progressively larger polymers by means of interchain disulfide bridges, and the extreme hydrophobicity of these polymers. The plasma membrane of extragonadal somatic cells absorbed 1.2 to 2.8% of these hydrophobic proteins. The unoccupied H-Y receptor sites residing on the plasma membrane of bovine fetal ovarian cells, on the other hand, selectively absorbed polymers of 18,000 mol. wt. subunits, and this antigen-receptor interaction, if allowed to continue for five days, induced the formation of tunica albuginea and seminiferous tubules in bovine XX embryonic indifferent gonads. In this manner, human H-Y antigen excreted by Daudi cells has functionally been identified as a series of polymers derived from 18,000 mol. wt. subunits. While, the H-Y antigenic determinants were retained even by the largest polymeric form that became irreversibly water insoluble, the receptor binding activity was shown only by 36.8% of the available polymeric forms of 18,000 mol. wt. subunits, at the most. Nevertheless, once bound to the receptor site, these polymers were rapidly reduced to the monomeric form on the plasma membrane of bovine fetal ovarian cells. Accordingly, the 18,000 mol. wt. monomer might actually represent the functional form of H-Y antigen.

Animals↗
PubMed1978

Ultrastructural localization of glycogen in the granulocytes of normal rabbit bone marrow.

The glycogen of rabbit granulocytes has been studied in glutaraldehyde and osmium tetroxide fixed bone marrow by the periodic acid-thiocarbohydrazide-silver proteinate procedure (PA-TCH-SP). The PA-TCH-SP procedure involved the staining of intracytoplasmic glycogen more densely than the routine lead citrate staining. The PA-TCH-SP procedure demonstrated the intracytoplasmic glycogen in all three kinds of granulocytes. Though a sequence of intensity was observed in each stage of cell maturation, intracytoplasmic glycogen increased generally in accordance with cell maturation in the granulocytes. Functional significance of the glycogen in the granulocytes was discussed in relation to its staining. A very weak reaction in the granules of the granulocytes was described in relation to their contents.

Animals↗