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Biomedical subjects

Y Ohe

Publications and source records attributed to Y Ohe.

At least 199 records · Page 11Linked to original sources
PubMed1982

Human spleen histone H4. Isolation and amino acid sequence.

The amino acid sequence of human spleen histone H4 was investigated as part of a study on histone evolution, following previous investigations of human spleen histones H2B (J. Biochem. 85, 615-624), H2A (J. Biochem. 88, 27-34), and H3 (J. Biochem. 90, 1205-1211). The H4 fraction was obtained as described previously and further purified by Bio-Gel P-60 chromatography. The purified H4 was digested with trypsin and the peptides were fractionated by repeated column chromatographies with reasonable recoveries. Certain peptides were sequenced, and three modified residues (alpha-N-Ac-Ser-1, epsilon-N-Ac-Lys-16, and epsilon-N-Me-Lys-20) and one heterogeneous residue (Asn/Asp-25), which is probably a result of postsynthetic deamidation, were found. Thus, the human H4 was deduced to have a sequence of 102 amino acid residues completely identical with that of calf thymus H4, including the presence of three modified residues and the absence of any variant sequence. It is concluded that the animal H4 sequences and their postsynthetic modifications have been strongly conserved during the evolutionary process leading to man, as strongly as or more strongly than the H3 sequence, and much more strongly than the H2A and H2B sequences.

Amino Acid Sequence↗
PubMed1982

Presence of pluripotent haemopoietic precursors in vitro (CFU-mix) in haemopoietic tissues from mice of W/Wv genotype.

The presence or absence of haemopoietic precursors, which produce mixed colonies in vitro (CFU-mix) was examined in the bone marrow and spleen of (WB X C57BL/6) F1-W/Wv mice. Despite the failure of macroscopically evident colony-formation in the spleens of irradiated mice, haemopoietic cells of W/Wv mice did produce macroscopically-evident mixed colonies containing erythroid cells, macrophages, and often megakaryocytes, in culture medium. The size and constitution of mixed colonies derived from W/Wv mice were comparable to those of mixed colonies from congenic +/+ mice. The present results appear consistent with in vivo haemopoiesis in the W/Wv mice, which is obviously deficient, but sufficient for survival.

Anemia, Macrocytic↗
PubMed1982

A case of severe aplastic anaemia successfully treated by retransplantation from the same donor.

A 16-year-old girl with severe aplastic anaemia was successfully treated with retransplantation of bone marrow from an HLA-identical sibling after rejection of the first transplantation from the same donor. Cyclophosphamide was used for the first transplantation and cyclophosphamide, 300 rad total-body irradiation and antilymphocyte globulin were used for the second transplantation. Permanent engraftment was achieved after the retransplantation with normalization of haemopoiesis, which has lasted for over 17 months. The patient is now in excellent clinical condition with minimal signs of chronic graft versus host disease.

Adolescent↗
PubMed1982

HLA antigens expressed on human pluripotent hemopoietic precursors in vitro (CFUMIX).

The human major histocompatibility antigen HLA, plays an important role in transplantation. To ascertain the expression of the antigens of HLA-A and -B loci on the surface of human pluripotent hemopoietic progenitors (CFUMIX), the cytotoxic effect of specific anti-HLA sera was examined. Anti-HLA sera and complement formed fewer colonies from CFUMIX in a culture medium than the controls which were treated with autologous serum. In our experiments, the HLA antisera killed also T cells that carry the surface antigen. Then the influences of T cells on mixed colony formation were examined. No reduction of colony formation was observed from the cell suspension in which T cells were depleted by treatment of monoclonal antibody OKT3. These results indicated that CFUMIX expressed HLA antigens on their surface.

Antigens, Surface↗
PubMed1981

Human spleen histone H3. Isolation and amino acid sequence.

The amino acid sequence of human spleen histone H3 was investigated as a study in histone evolution, following previous investigations of human spleen histone H2B [Ohe, Y., Hayashi, H., & Iwai, K. (1979) J. Biochem. 85, 615-624] and H2A [Hayashi, T., Ohe, Y., Hayashi, H., & Iwai, K. (1980) J. Biochem. 88, 27-34]. The H3 fraction was obtained as described previously and further purified by Bio-Gel P-10 chromatography. The reduced and carboxymethylated H3 was digested with an arginine-specific protease, Clostripain, and the peptides were fractionated by repeated column chromatographies with reasonable recoveries. Most of these peptides, together with two tryptic peptides and one chymotryptic peptide obtained similarly, were sequenced by Edman degradation. Thus, the human H3 was deduced to have a sequence of 135 amino acid residues identical with that of the main component of calf thymus H3, except for one complete substitution (Ser for Cys-96) and four partial substitutions (Ser for Ala-31, Ala for Ser-87, Ile for Val-89, and gly for Met-90), which suggest the presence of at least two variants. Three methylated lysines (residues 9, 27, and 36) and two acetylated lysines (residues 14 and 23) were also found. The substitutions and modifications found in the human H3 are compared with those in the known H3 sequences of other eukaryotes, and the implications are discussed.

Amino Acid Sequence↗
PubMed1981

HLA antigens expressed on human erythroid burst forming cells.

The human major histocompatibility antigens HLA, play an important role in transplantation. To ascertain the expression of the antigens of A and B loci on the surface of human hemopoietic progenitors, the cytotoxic effect of specific anti-HLA sera was examined. Anti-HLA A2 and B5 sera were used in the present experiments. Circulating blood mononuclear cells and nucleated marrow cells, pretreated with appropriate specific anti-HLA sera and complement, formed fewer colonies from BFU-e and CFU-c in a culture medium than the controls which were treated with autologous serum. In our experiments, the HLA antisera also killed macrophages, monocytes, and T cells which carry the surface antigen. Then, the influence of macrophages, monocytes, and T cells on colony formation from BFU-e and CFU-c was examined. These results indicated that BFU-e as well as CFU-c expressed HLA antigens on their surface.

Antibody Specificity↗
PubMed1981

Pluripotent, erythrocytic and granulocytic hemopoietic precursors in chronic granulocytic leukemia.

Using methylcellulose culture techniques, we investigated the behavior of committed and pluripotent hemopoietic precursors (CFUMIX) in marrow cells and blood from patients with chronic granulocytic leukemia (CGL) in the chronic phase whose marrow cells showed the presence of Ph1 chromosomes. The relative concentrations of the marrow precursors in CGL were nearly equal to those in control patients. The mean nucleated cell count in marrow fluid from the patients, however, was 6.3 times that of control values. As a result, the mean concentrations per unit volume of the hemopoietic precursors in CGL were significantly higher than those in control patients. Furthermore, the presence of erythropoietin (Ep) independent BFUE giving rise to erythropoietic bursts in the medium without the addition of Ep was demonstrable in marrow cells and blood. In the peripheral blood, the increment in numbers of CFUC, CFUE, BFUE, and CFUMIX in accordance with the leucocyte count was observed. The present results are consistent with the theory that the clonal expansion in CGL occurs at the level of pluripotent hemopoietic precursors and suggest that CFUMIX in CGL can differentiate into CFUE along the erythropoietic pathway and that a regulatory defect in CGL in present in both granulocytic cells and erythrocytic cells.

Adult↗
PubMed1980

Pluripotent hemopoietic precursors in vitro (CFUMIX) in aplastic anemia.

When human marrow cells were cultured in a medium containing alpha-medium, methylcellulose, fetal calf serum, bovine serum albumin, erythropoietin, and leucocyte-conditioned medium, mixed colonies composed of erythrocytic cells and granulocytes were formed. The clonal nature of the mixed colonies was confirmed by the linear relationship between the numbers of cells plated and the number of colonies, and the absence or presence of Y-chromatin in the mixed colonies in a co-culture experiment with male and female cells. Using the methylcellulose cell culture techniques, the pluripotent hemopoietic precursors (CFUMIX) in marrow cells from 15 patients with aplastic anemia were assayed. In the control subjects of patients with iron-deficiency anemia, lymphoadenitis, reactive leucocytosis or Hodgkin's disease, 8 X 10(5) marrow cells in 4 dishes produced 12.7 +/- 6.9 (mean +/- SD) mixed colonies. On the other hand, 8 X 10(5) marrow cells from patients with aplastic anemia formed only 2.1 +/- 5.5 (mean +/- SD) mixed colonies. Furthermore, the marrow cells from 5 patients who were repeatedly receiving transfusions contained no CFUMIX which give rise to mixed colonies. The present results provided the first direct evidence that pancytopenia in most patients with aplastic anemia results from a reduced influx into the compartment of maturing hemopoietic cells from the compartment of pluripotent hemopoietic precursors.

Adult↗
PubMed1979

Human spleen histone H2B. Isolation and amino acid sequence.

The amino acid sequences of human histones have been investigated for studies of histone evolution. The whole histone was prepared from human spleen and was separated into 3 fractions, H4+H3+H2A, H2B, and H1, by our technique of CM-cellulose chromatography. The H2B fraction was further purified by Bio-Gel P-60 chromatography. For sequence determination, the H2B molecule was first split into 4 major fragments I to IV, by limited chymotryptic digestion at pH 5.0 and 15 degrees C, followed by Sephadex G-50 chromatography. Fragments I and III were then digested with trypsin, yielding 18 and 16 peptides, respectively, on column and paper chromatographies. Sequence analyses of these tryptic peptides, as well as chymotryptic fragments II and IV, showed no differences from the corresponding parts of calf thymus H2B sequence, making it possible to locate fragments I to IV at residues 1--40, 41--42, 43--121 and 122--125 of the total sequence. The only new findings were microheterogeneities at residues 39 (75% valine and 25% isoleucine) and 124 (70% serine and 30% alanine). The sequence of the most basic cluster at residues 27--24, -Lys-Lys-Arg-Lys-Arg-Ser-Arg-Lys-, was confirmed with a peptide obtained from fragment I by staphylococcal protease digestion. Thus, it is concluded that the H2B sequence of lower mammals was conserved during the evolutionary process leading to man.

Amino Acid Sequence↗