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Biomedical subjects

H Ohno

Publications and source records attributed to H Ohno.

At least 505 records · Page 28Linked to original sources

Central effect of atrial natriuretic polypeptide on angiotensin II-stimulated vasopressin secretion in conscious rats.

The effect of intracerebroventricular (i.c.v.) treatment of alpha-human atrial natriuretic polypeptide on the vasopressin secretion induced by i.c.v. injection of angiotensin II was studied in conscious, unrestrained rats. Pretreatment of alpha-human atrial natriuretic polypeptide (5 micrograms) significantly inhibited the angiotensin II (100 ng)-stimulated vasopressin secretion. This result suggests that atrial natriuretic polypeptide plays regulatory roles in vasopressin secretion in the central nervous system.

Angiotensin II↗

Establishment of a new myeloid leukemia cell line (TK-1), and isolation of cells having a translocation involving a band 17q23.

A myeloid leukemia cell line (TK-1) was established from the peripheral blood of a patient with lymphoblastic lymphoma whose leukemia cells were composed of T-lymphoblasts and immature myeloid cells. The established TK-1 cell line consisted of immature myeloid cells with heavy azurophilic granulation in the cytoplasm. The TK-1 cells were positive for peroxidase, and exhibited a strong positive reaction for alpha-naphthyl acetate esterase and naphthol AS-D chloroacetate esterase. The cells were weakly positive for Fc gamma-receptors, showed no phagocytosis and did not reduce NBT. With the treatment of 1 alpha, 25-dihydroxy-vitamin D3, they exhibited morphological and functional differentiation. The TK-1 cell line contained normal diploid cells and pseudodiploid cells, and the two populations were successfully cloned; the clone with a normal karyotype was designated the TK-1D cell line, and the clone with a pseudodiploid karyotype, which had a translocation involving chromosomes 14, 17 and one other chromosome, was designated the TK-1B cell line. These cloned cells lacked Epstein-Barr virus nuclear antigens and had almost the same myelomonocytic characteristics as the parent TK-1 cells. The breakpoint of chromosome 17 involved in the translocation of the pseudodiploid cells was identified to be a band 17q23.

Adult↗

Recurrent chromosome abnormalities in adult T-cell lymphomas of peripheral T-cell origin.

Cytogenetic studies were performed on 11 Japanese patients with adult T-cell lymphoma of peripheral T-cell origin. All patients had a histologic diagnosis of diffuse lymphoma, and were treated with intensive combination chemotherapy; their median survival was 6 months. Lymphomas were categorized on the basis of the classification proposed by the Lymphoma Study Group of Japan: 5 patients had the features of pleomorphic lymphoma; 3, mixed lymphoma; 2, large-cell lymphoma; and 1, medium-sized-cell lymphoma. The modal chromosome number of abnormal cells was near-diploid in 7, and hypotetraploid in 4 including 3 patients with pleomorphic lymphoma. Abnormalities of the clonal chromosomes were observed in all 11 patients. A translocation of the short arm of 19 at band 19p13 was found in 2 patients with pleomorphic lymphoma and in one patient each with mixed lymphoma and medium-sized-cell lymphoma. A translocation of the short arm of 14, with a break at band 14p12, occurred in 4 patients with pleomorphic lymphoma. In one patient each with mixed lymphoma and large-cell lymphoma, an extra chromosome 3 was found. The numerical change was unique because their lymphomas were further categorized as "angioimmunoblastic lymphadenopathy with dysproteinemia" and "large-cell immunoblastic lymphoma", respectively. Our findings suggest that characteristic chromosome abnormalities occur in adult T-cell lymphoma, and dividing cells in the tetraploid range tend to be predominant in pleomorphic lymphoma.

Adult↗

Calibration of the relative molecular mass of proteoglycan subunit by column chromatography on Sepharose CL-2B.

Calibration relationships were derived for cartilage proteoglycan subunit (PGS) that relate the inverse z-average hydrodynamic radius (Rs) and the weight-average Mr (Mw) to the partition coefficient (Kav.) for PGS when chromatographed on a Sepharose CL-2B column. PGS isolated from chick limb-bud chondrocyte cell cultures was fractionated chromatographically into eight pools, for which Mw and Rs were determined by total-intensity and dynamic light-scattering measurements. These data were found to be related to Kav. through the following empirical equations: log Mw = -(1.65 +/- 0.27)Kav. +(6.58 +/- 0.08); log Rs = -(0.69 +/- 0.04)Kav. +(2.75 +/- 0.01). Application of these relationships to the chromatographic data led to Mw = 1.48 X 10(6) and Rs = 38.7 nm (387 A) for the unfractionated specimens compared with values of Mw = 1.46 X 10(6) and Rs = 38.2 nm (382 A) determined by light-scattering. Our results were found to be consistent with previously proposed phenomenological models for the gel-filtration mechanism. Application of these calibration relationships to Kav. for several unfractionated specimens led to predicted values of Mw and Rs that are accurate to within 10%.

Animals↗

Effect of 3-aminobenzamide on the process of ultraviolet-induced DNA excision repair.

The effect of 3-aminobenzamide, a potent inhibitor of poly(ADP-ribosyl)ation, on UV-induced DNA excision repair was investigated. HeLa cells were treated with DNA replication inhibitors, hydroxyurea (HU) and 1-beta-D-arabinofuranosyl cytosine (araCyt), before and after ultraviolet light (UV) irradiation, to accumulate DNA single-strand breaks. The activity of poly(ADP-ribosyl)ation measured in the permeable cell system of HeLa cells was enhanced in a UV dose-dependent manner after the combined treatment with HU and araCyt in vivo. However, DNA repair synthesis in vitro was not affected by addition of 1 mM 3-aminobenzamide or nicotinamide, while incorporation of [3H]NAD in the same system was completely inhibited. Furthermore, neither the magnitude of UV-induced DNA single-strand breaks accumulated by the combined treatment of HU and araCyt nor the rate of their rejoining after release from the HU and araCyt block were influenced even in the presence of 10 mM 3-aminobenzamide. As the cytotoxicity of UV irradiation was significantly potentiated by 5 mM 3-aminobenzamide, these results suggest that poly(ADP-ribosyl)ation is involved in a process other than DNA excision repair induced by UV irradiation.

Adenosine Diphosphate Ribose↗

Monoclonal antibodies to human choriocarcinoma.

We have established two monoclonal antibodies (TM7-3 and TM3-8) that react to choriocarcinoma cells. Both of these monoclonal antibodies have shown a similar reactive pattern to human cell lines, normal and neoplastic trophoblast tissues, and other fetal and adult tissues. They have reacted to nine of the ten choriocarcinoma cell lines, as well as to Hela cells (a cervical carcinoma cell line). During a cellular radioimmunoassay, neither TM7-3 nor TM3-8 reacted to two T lymphoblastoid cell lines or three B lymphoblastoid cell lines. Immunofluorescence and immunoperoxidase staining showed that both monoclonal antibodies reacted selectively to the cytotrophoblast-like tumor cells of a choriocarcinoma and a hydatidiform mole but not to syncytiotrophoblast-like tumor cells. TM7-3 and TM3-8 also reacted slightly to the normal cytotrophoblast of early human chorionic villi under the same conditions as they did to choriocarcinoma tissues, TM7-3 and TM3-8 bind only to a part of the urinary tubles of the kidney and to the ducts of the pancreas of both adult and fetus.

Animals↗

The effect of brief physical exercise on free radical scavenging enzyme systems in human red blood cells.

Eleven sedentary male students were studied, using a bicycle ergometer, for 30 min at about 75% of their maximal oxygen uptake, to observe the effects of brief physical exercise on free radical scavenging system enzymes of the erythrocytes. Of the enzymes examined, only total glutathione reductase activity showed a significant elevation immediately after exercise and appeared to remain high at 30 min after exercise. The results suggest that acute physical exercise has some effects on red blood cell glutathione reductase activity, which is related primarily to maintenance of reduced glutathione.

Adult↗

[Studies of implantation traces in rats. III. Histological examination].

We carried out a histological examination of the implantation traces in delivered rats. The implantation traces could be identified more than 500 days after delivery on the mesometrial side as black and brown spots. The implantation traces were recognizable as a cicatrix remaining in the parametrium, mesometrial triangle, which was formed by repair of injury caused by placental desquamation. In this area, metrial gland cells which were laid down through pregnancy were recognized for about two months after delivery. The implantation traces consisted of cicatrix tissue associated with collagen production and hemosiderin. It was possible to distinguish old and new traces by the size of the siderophile cells and by the degree of hemosiderin present. It was also possible to discriminate new traces as yellowish-brown areas, covered with a yellowish-white mass of degenerated metrial gland, in cleared uteri stained with 2% NaOH solution. Siderophile cells on the implantation traces were derived from giant cells which persisted around the peripheral region of the placental desquamation site, and these giant cells were considered to be identifiable with metrial gland cells. It was considered that formation of the cicatrix is essentially the same in abortion, stillbirth and normal delivery. However, it was found that the implantation traces had different histological appearances depending on the degree of injury to the endometrium and myometrium and time of placental desquamation. The iron content of the implantation traces corresponded quantitatively with the hemosiderin observed in the histological investigations. The iron content decreased rapidly up to 21 days after delivery, decreasing gradually thereafter. The iron in the implantation traces could, however, be analyzed quantitatively by atomic absorption spectroscopy until day 365 after delivery.

Animals↗