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Biomedical subjects

T Ohnuki

Publications and source records attributed to T Ohnuki.

At least 91 records · Page 5Linked to original sources
PubMed1987

New monoclonal antibodies specific for the guinea pig line 10 hepatocarcinoma.

Monoclonal antibodies reactive to line 10 (L10) hepatocarcinoma cells, but not to L2C leukemia cells, of strain 2 guinea pig were produced and characterized. Complement-mediated cytolysis assay and quantitative absorption analysis revealed that one of the monoclonal antibodies, 3C4 antibody (IgG2a), was highly specific for L10. Neither normal guinea pig tissues including adult and fetal liver, nor other hepatomas of strain 2 guinea pig, line 1 (L1) and Hepatoma III, were reactive with the 3C4 antibody. Another antibody, 2E4 (IgM), was reactive to the liver, kidney and spleen cells but not to the thymocytes, lymph node cells, brain and red blood cells of the guinea pig. The 2E4 antibody reacted to Hepatoma III but not to L1 cells. Therefore, 3C4 antibody is specific to a tumor-associated antigen of L10 hepatoma, and 2E4 antibody is cross-reactive with a certain differentiation antigen of normal tissues. The 3C4 antibody showed antibody-dependent cytotoxicity. Since 3C4 antibody was different in the isotype and the antigen recognized from a monoclonal antibody (D3) which was reported from the NIH in the USA, 3C4 is a new monoclonal antibody reactive with L10 hepatocarcinoma.

Animals↗
PubMed1987

[Transrectal longitudinal ultrasonography of the prostate by electronic linear scanning (1)].

Transrectal longitudinal ultrasonography of the prostate was done for 20 patients with prostatic diseases, 12 with benign prostatic hypertrophy, 6 with bladder neck contracture, and 2 with chronic prostatitis. The intravesical protrusion of the prostate and the opening of the bladder neck, which can be easily recognized by this method, were discussed in relation to dysuria, using subjective symptoms, residual urine, and uroflowmetry (peak flow rate) as parameters. The former was slightly correlated to dysuria, and the latter was definitely correlated to dysuria.

Aged↗
PubMed1986

Branching architecture of canine pulmonary arteries: a quantitative cast study.

The purpose of this investigation is to analyze the branching pattern of pulmonary artery. The excised right lower lobes of six mongrel dogs were fixed by perfusion with 1.2% glutaraldehyde solution. Pressure of the pulmonary artery, vein and airway were controlled during perfusion. After fixation, resin was injected manually into the artery. When resin was completely polymerized, the lung was placed in 15 N NaOH solution to remove lung tissue. The diameters and lengths of branches were measured by stereomicroscopy. The results obtained were as follows: The basically dichotomous pulmonary arteries showed not only fairly regular dichotomies but monopodies, in the latter of which the diameter of parent branch was almost the same as that of its larger daughter branch. The diameter of monopodial branch was less than 500 microns, even when the parent branch was a large central segment. In arteries of over 1,000 microns in diameter, 75% or more of branchings were monopodies, whereas in small arteries of 200-300 microns in diameter, half the bifurcations were monopodies. At a bifurcation, the average daughter-to-parent diameter ratio was 0.8-0.9 for the larger daughter branch and 0.5 for the smaller one. The average length of branches was in proportion to their average diameter.

Animals↗
PubMed1985

Isolation of streptomycin-nonproducing mutants deficient in biosynthesis of the streptidine moiety or linkage between streptidine 6-phosphate and dihydrostreptose.

Eight streptidine idiotrophic mutants (SD20, SD81, SD141, SD189, SD245, SD261, SD263, and SD274) which required streptidine to produce streptomycin were derived from Streptomyces griseus ATCC 10137 by UV mutagenesis. By both the characterization of intermediates accumulated by the idiotrophs and the assay of enzymes involved in streptidine biosynthesis, the biochemical lesions of the mutants were deduced as follows: SD20 and SD263, transamination; SD81, SD261, and SD274, phosphorylation; SD141, transamidination; SD189, dehydrogenation; SD245, linkage between streptidine 6-phosphate and dihydrostreptose. An accumulation of streptidine 6-phosphate was found in SD245 to impair its aminotransferase activity. This finding suggests that aminotransferase activity might have been negatively controlled by the end product, streptidine 6-phosphate, of the streptidine biosynthetic pathway.

Amidinotransferases↗
PubMed1985

Molecular cloning of tetracycline resistance genes from Streptomyces rimosus in Streptomyces griseus and characterization of the cloned genes.

Two tetracycline resistance genes of Streptomyces rimosus, an oxytetracycline producer, were cloned in Streptomyces griseus by using pOA15 as a vector plasmid. Expression of the cloned genes, designated as tetA and tetB was inducible in S. griseus as well as in the donor strain. The tetracycline resistance directed by tetA and tetB was characterized by examining the uptake of tetracycline and in vitro polyphenylalanine synthesis by the sensitive host and transformants with the resultant hybrid plasmids. Polyphenylalanine synthesis with crude ribosomes and the S150 fraction from S. griseus carrying the tetA plasmid was resistant to tetracycline, and, by a cross-test of ribosomes and S150 fraction coming from both the sensitive host and the resistant transformant, the resistance directed by tetA was revealed to reside mainly in crude ribosomes and slightly in the S150 fraction. However, the resistance in the crude ribosomes disappeared when they were washed with 1 M ammonium chloride. These results suggest that tetA specified the tetracycline resistance of the machinery for protein synthesis not through ribosomal subunits, but via an unidentified cytoplasmic factor. In contrast, S. griseus carrying the tetB plasmid accumulated less intracellular tetracycline than did the host, and the protein synthesis by reconstituting the ribosomes and S150 fraction was sensitive to the drug. Therefore, it is conceivable that tetB coded a tetracycline resistance determinant responsible for the reduced accumulation of tetracycline.

Biological Transport↗
PubMed1985

Self-cloning in Streptomyces griseus of an str gene cluster for streptomycin biosynthesis and streptomycin resistance.

An str gene cluster containing at least four genes (strR, strA, strB, and strC) involved in streptomycin biosynthesis or streptomycin resistance or both was self-cloned in Streptomyces griseus by using plasmid pOA154. The strA gene was verified to encode streptomycin 6-phosphotransferase, a streptomycin resistance factor in S. griseus, by examining the gene product expressed in Escherichia coli. The other three genes were determined by complementation tests with streptomycin-nonproducing mutants whose biochemical lesions were clearly identified. strR complemented streptomycin-sensitive mutant SM196 which exhibited impaired activity of both streptomycin 6-phosphotransferase and amidinotransferase (one of the streptomycin biosynthetic enzymes) due to a regulatory mutation; strB complemented strain SD141, which was specifically deficient in amidinotransferase; and strC complemented strain SD245, which was deficient in linkage between streptidine 6-phosphate and dihydrostreptose. By deletion analysis of plasmids with appropriate restriction endonucleases, the order of the four genes was determined to be strR-strA-strB-strC. Transformation of S. griseus with plasmids carrying both strR and strB genes enhanced amidinotransferase activity in the transformed cells. Based on the gene dosage effect and the biological characteristics of the mutants complemented by strR and strB, it was concluded that strB encodes amidinotransferase and strR encodes a positive effector required for the full expression of strA and strB genes. Furthermore, it was found that amplification of a specific 0.7-kilobase region of the cloned DNA on a plasmid inhibited streptomycin biosynthesis of the transformants. This DNA region might contain a regulatory apparatus that participates in the control of streptomycin biosynthesis.

Amidinotransferases↗
PubMed1985

Immunological involvement in pulmonary fibrosis induced by peplomycin.

Pulmonary fibrosis in mice induced by peplomycin (PEP) was suppressed by administration of anti-inflammatory agents such as prednisolone and D-penicillamine during or after the administration of PEP. Pulmonary fibrosis was also suppressed by administration of cyclophosphamide, an immunosuppressive antitumor agent before, during or after the administration of PEP. The pulmonary fibrosis in athymic nude mice induced by PEP was less than that in normal mice. The low response in the nude mice was enhanced by transfer of thymocytes to the same level as that in the normal mice. This suggests that the immune system, especially thymus-dependent immunity, is involved in the pulmonary fibrosis induced by PEP.

Animals↗
PubMed1985

[Assessment of ability to withstand lung resections and post-operative survival in patients with respiratory disorders and bronchogenic carcinoma].

Of 1192 lung resections in patients with bronchogenic carcinoma since 1952, the early post-operative mortality averaged 3.9%, whereas during the last ten years, it was 2.6% of 730 lung resections, including 159 (22%) pneumonectomies, 76 (10%) bilobectomies, 492 (67%) single lobectomies and 3 (0.4%) partial lung resections. In the latter, 352 (48.2%) and 75 (10%) had airway obstructive failure of FEV1.0 less than 70% and 55%, respectively, and, 56 (7.7%) and 9 (1%) represented preoperative hypoxia of PaO2 less than 70 torr and 60 torr, respectively. The ratios of pneumonectomies in these, being similar to those with better lung functions, the perioperative mortality was also similar. Our previously reported indices preoperatively to prove ability to withstand curative lung resections, being supported by these data, we attempted in a certain limited group of patients, extendingly to clear patients with critically poor predicted pulmonary vascular reserve pf 710-930 dyne . cm-5 . sec/m2 for lung resections, resulting in six elevenths of over one year survival. One must extend benefit of lung resection to patients with coexistence of bronchogenic carcinoma and respiratory disorder apparently severe enough to preclude resection surgery by critical assessment of the predicted pulmonary vascular reserve after lung resection.

Aged↗
PubMed1983

Isolation and characterization of pock-forming plasmids for Streptomyces griseus from soil actinomycetes.

Thirty independent actinomycetes strains carrying plasmids were isolated from soil. These plasmids were purified as cccDNA by CsCl-EtBr equilibrium density-gradient centrifugation. Plasmids that induce "pocks", namely formation of circular zones of sporulation-inhibition, were selected by protoplast transformation of streptomycin-producing strain, Streptomyces griseus ATCC10137. Six pock-forming plasmids, pOA7, pOA11, pOA15, pOA23, pOA29 and pOA30, were obtained, and their cleavage maps, transformation frequencies, and copy numbers, as well as their stability, are described.

Actinomycetales↗
PubMed1983

Marinactan, antitumor polysaccharide produced by marine bacteria.

Extracellular polysaccharides of marine bacteria were screened for their antitumor activity against sarcoma-180 solid tumor in mice. An active polysaccharide was purified and named marinactan. The producing microorganism has a typical marine bacterial nature requiring sea water for growth and was identified as Flavobacterium uliginosum. Marinactan is a novel heteroglycan consisting of glucose, mannose and fucose in a ratio of approximately 7:2:1. Marinactan, 10-50 mg mg/kg daily for 10 days i.p., produced 70-90% inhibition of the growth of solid sarcoma 180. Complete regression of the tumor was observed in some treated mice. Its administrations before and after tumor transplantation showed almost the same inhibitory effect. Marinactan prolonged markedly the survival period of mice bearing ascites sarcoma 180.

Animals↗
PubMed1983

Autologous rosette forming cells in patients with renal diseases.

We studied the distribution of autologous rosette forming cells (ARFC) in the peripheral blood of 30 healthy adult donors, 30 patients with IgA nephropathy, 20 patients with primary glomerular diseases, eight patients with systemic diseases and 25 patients with other renal diseases. The mean percentages of ARFC were markedly reduced in the IgA nephropathy patients compared with the healthy adult donors. The values for ARFC were even more significantly reduced in IgA nephropathy patients compared with patients with primary glomerular diseases, systemic diseases and other renal diseases. This means that the immunoregulatory abberation in IgA nephropathy primarily involves T cells.

Adult↗