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Biomedical subjects

M Nakano

Publications and source records attributed to M Nakano.

At least 1,081 records · Page 60Linked to original sources
PubMed1985

DNA strand scission by enzymatically reduced mitomycin C: evidence for participation of the hydroxyl radical in the DNA damage.

Phage DNA, as well as plasmid and mammalian DNA's, were exposed to a superoxide and hydroxyl radical-generating system containing NADPH-cytochrome P-450 reductase and mitomycin C, both with and without added Fe3+-ADP, in phosphate buffer at pH 7.5. The generation of superoxide (O2-.) and hydroxyl (.OH) radicals in the system was demonstrated by using ESR spectrometry with N-tert -butyl-alpha-phenylnitrone (PBN) as a spin trapping agent. Only the lambda DNA isolated after exposure to the O2-./.OH-generating system containing many lower molecular weight DNA fragments indicating DNA strand breaks. This breakage was completely inhibited by a .OH radical scavenger (sodium benzoate) and by catalase, but only slightly by superoxide dismutase. Thyroid and plasmid DNA's were both cleaved when exposed to the O2-./.OH-generating systems. It is suggested that the mechanism of DNA scission by mitomycin C described here closely resembles that induced by the anthracycline drugs.

Animals↗
PubMed1985

Synergistic effect of concanavalin A and Bu-WSA on DNA synthesis in human peripheral blood lymphocytes.

Butanol-extracted water soluble adjuvant (Bu-WSA) obtained from Bacterionema matruchotii was not mitogenic for human peripheral blood mononuclear cells (PBM) but was capable of enhancing (3H) thymidine uptake of T cells stimulated by concanavalin A (Con A) in the presence of B cells or macrophages (M phi) in vitro. The mechanisms of the synergy of Con A and Bu-WSA were studied by using separated cell populations from PBM. Both subfractioned OKT4+ and OKT8+ cells were responsive to co-stimulation by Con A and Bu-WSA in the presence of an accessory cell population. Allogeneic B cells and M phi as well as autologous cells had helper function as accessory cells. Heavy irradiation with gamma-rays did not affect the function of the accessory cells, but previous treatment of B cells with anti-Ig serum plus complement (C) or treatment of M phi with anti-M phi serum plus C deprived them of their function. The treatment of accessory cells with anti-HLA-DR serum, regardless of the presence or absence of C, resulted in loss of their helper function. Cultures in Marbrook-type vessels showed that a mixed cell population of T cells and accessory cells in the lower chamber produced some active factor(s) after co-stimulation with Con A and Bu-WSA, and by passing through the membrane filter separating the chambers, the factor(s) enhanced the proliferation of the Con A-activated T cell population in the upper chamber. The factor(s) was presumed to be interleukin 2 (IL 2), because it supported the growth of IL 2-dependent CTLL cells. These results indicate that the synergy of Con A and Bu-WSA on the proliferative response of human PBM is due to the elevation of growth factor production from T cells stimulated by those mitogens.

Actinomycetaceae↗
PubMed1985

Ascorbate induced lipid peroxidation results in loss of receptor binding in tris, but not in phosphate, buffer. Implications for the involvement of metal ions.

Rat brain homogenate was incubated with various concentrations of ascorbate in a Tris-HC1 buffer. Thiobarbituric acid-reactive substances (TBARS) were measured and 3H-QNB (quinuclidinyl benzilate) binding was also assayed on the same homogenate. Good parallelism between TBARS formation and loss of 3H-QNB binding activity confirmed that loss of 3H-QNB binding resulted from ascorbate-induced lipid peroxidation. However, neither formation of TBARS nor loss of 3H-QNB binding occurred in phosphate buffer or in the Tris-HC1 system in the presence of metal-chelating reagents. This indicates that phosphate addition prevents the ascorbate effects due to complete chelation of intrinsic metal ions.

Animals↗
PubMed1985

[Radiotherapy of carcinoma of the larynx--dose and function preservation].

Relationship between irradiated dose and function preservation of the larynx in patients of laryngeal carcinoma (T1-T3) treated with radiotherapy were analysed and discussed. Local control rate for T1 and T2 lesion was highest in the dose range of 65-70 Gy. But in T3 lesion, especially of supraglottic cancer, the dose range to obtain highest local tumor control rate is above 76 Gy and higher than in case of T1 and T2 lesions. Laryngeal edema was seen in patients who were delivered the dose of 80 Gy. But total laryngectomy could be avoided by conservative therapy. Necessity of induction chemotherapy for advanced cases was also discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

[Radiotherapy (interstitial irradiation) of carcinoma of the tongue--an analysis of cases in the past 10 years].

A total of 82 histologically proven squamous cell carcinomas of the tongue, which were treated by interstitial irradiation (radium) at Chiba Cancer Center from 1973-1982, were reviewed. The cumulative five-year survival rate of all cases was 64%: 78% in Stage I and II group, 68% in Stage III and 47% in Stage IV. Local recurrence was noted in eight cases (10%) and later cervical node metastases in 14 cases 25% in T 1-4 N 0). The incidence of mandibular osteoradionecrosis was 18 cases (22%).

Adult↗
PubMed1985

[Chemotherapy in biliary tract infections (XXX). Special reference to the concentration of micronomicin in human gallbladder tissues and bile].

In this study, 120 mg of micronomicin (MCR) was given to 15 cases intended for cholecystectomy intramuscularly by a single injection or 5 consecutive injections (in the evening of day -2, morning and evening of day -1, morning of day 0, and 1 hour before operation) or intravenously by 1-hour drip infusion, and levels of MCR in serum, B bile and gallbladder tissues were determined by means of HPLC and bioassay. The serum level of MCR 30 minutes after consecutive injections (8 cases) was 11.86 +/- 1.90 micrograms/ml, significantly higher than that after the single injection, 7.08 +/- 0.93 micrograms/ml. The highest bile level of MCR after consecutive injections was 10.0 micrograms/ml. The average level in 4 detectable cases, 6.33 +/- 2.06 micrograms/ml, came up to 50% of the serum level and was higher than that after the single injection, 3.53 +/- 1.39 micrograms/ml. The gallbladder tissue level of MCR after consecutive injections was 4.5 micrograms/g at the highest and 2.51 +/- 0.73 micrograms/g on the average in 5 detectable cases. This was equivalent to 20% of the serum level and higher than that after the single injection, 1.63 +/- 0.26 micrograms/g. The MIC of MCR could be determined against 8 of 10 strains detected in B bile. Against E. coli and K. pneumoniae, main causal bacteria of bile duct infections, it was as low as 0.39 to 0.78 micrograms/ml. Levels of MCR in bile and gallbladder tissues determined in this study exceeded by far the above MIC. From these results, it can be expected that clinical administration of MCR at 2 doses of 120 mg daily for 3 days or more will give rise to a sufficiently antibacterial effect against Gram-negative bacilli.

Adult↗