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Biomedical subjects

K Asano

Publications and source records attributed to K Asano.

At least 415 records · Page 23Linked to original sources
PubMed1986

Reduced turnover of the elongation factor EF-1 X ribosome complex after treatment with the protein synthesis inhibitor II from barley seeds.

The effect of the protein synthesis inhibitor II from barley seeds (Hordeum sp.) on protein synthesis was studied in rabbit reticulocyte lysates. Inhibitor treatment of the lysates resulted in a rapid decrease in amino acid incorporation and an accumulation of heavy polysomes, indicating an effect of the inhibitor on polypeptide chain elongation. The protein synthesis inhibition was due to a catalytic inactivation of the large ribosomal subunit with no effect on the small subparticle. The inhibitor-treated ribosomes were fully active in participating in the EF-1-dependent binding of [14C]phenylalanyl-tRNA to poly(U)-programmed ribosomes in the presence of GTP and the binding of radioactively labelled EF-2 in the presence of GuoPP[CH2]P. Furthermore, the ribosomes were still able to catalyse peptide-bond formation. However, the EF-1- and ribosome-dependent hydrolysis of GTP was reduced by more than 40% in the presence of inhibitor-treated ribosomes, while the EF-2- and ribosome-dependent GTPase remained unaffected. This suggests that the active domains involved in the two different GTPases are non-identical. Treatment of reticulocyte lysates with the barley inhibitor resulted in a marked shift of the steady-state distribution of the ribosomal phases during the elongation cycle as determined by the ribosomal content of elongation factors. Thus, the content of EF-1 increased from 0.38 mol/mol ribosome to 0.71 mol/mol ribosome, whereas the EF-2 content dropped from 0.20 mol/mol ribosome at steady state to 0.09 mol/mol ribosome after inhibitor treatment. The data suggest that the inhibitor reduces the turnover of ribosome-bound ternary EF-1 X GTP X aminoacyl-tRNA complexes during proof-reading and binding of the cognate aminoacyl-tRNA by inhibiting the EF-1-dependent GTPase.

Animals↗
PubMed1986

Hymenolepis nana: passive transfer of mouse immunity by T-cell subset of phenotype Lyt-1.

Mesenteric lymph node cells obtained from donor mice (BALB/c strain) actively immunized by oral inoculation with Hymenolepis nana eggs were syngeneically transferred by intravenous injection into athymic nude mice previously uninfected. The adoptively immunized recipients were then challenged with 1000 H. nana eggs 2 days after cell transfer. The degree of immunity transferred was assessed by examining cysticercoids developed in the intestinal villi of the recipients on Day 4 of challenge infection. The criterion for success in cell transfer of immunity was the complete rejection of cysticercoids as was generally expected in mice infected previously. The transfer of 1.5 X 10(8) immune mesenteric lymph node cells obtained from donors immunized 4 days before cell collection resulted invariably in the complete rejection of cysticercoids, though not less than this cell dosage. The immunity was passively transferable to recipients by T cells, especially by T-cell subset of phenotype Lyt-1 but not those of phenotype Lyt-2.3 and Lyt-1.2.3. However, 1.5 X 10(8) immune mesenteric lymph node cells obtained from donors immunized 21 days before cell transfer and 1.5 X 10(8) immune spleen cells obtained from donors immunized 4 days before cell transfer had little or no effect on the rejection of cysticercoids.

Animals↗
PubMed1986

Conduction disturbance and tachyarrhythmia in postoperative ventricular septal defect and tetralogy of Fallot.

The importance of conduction disturbances and tachyarrhythmias as the determining factors of the late results of postoperative patients with ventricular septal defect and tetralogy of Fallot was reconfirmed in this follow-up study. It was found, however, that the incidences of complete heart block, bilateral bundle-branch block, and ventricular tachyarrhythmia have decreased significantly since the establishment of cold cardioplegia. This has certainly contributed to the remarkable improvement in late follow-up results of postoperative patients with ventricular septal defect or tetralogy of Fallot.

Arrhythmias, Cardiac↗
PubMed1986

DC-86-M, a novel antitumor antibiotic. I. Taxonomy of producing organism and fermentation.

A novel antibiotic, DC-86-M was isolated from the culture broth of a new isolate, DO-86, from the soil sample collected in Machida-shi, Japan. The producing organism was found to belong to Streptomycetes, for it formed aerial mycelia and chains of spores and its cell wall analyses revealed the presence of LL-diaminopimelic acid. The morphological, cultural and physiological characteristics of the strain DO-86 resemble closely those of Streptomyces luteogriseus and we concluded that the strain DO-86 could be designated as Streptomyces luteogriseus DO-86. The antibiotic was produced in the fermentation medium consisting of lactose 20 g, glucose 10 g, Pharmamedia 15 g, yeast extract 5 g, meat extract 10 g and CaCO3 2 g per liter of tap water.

Actinomycetales↗
PubMed1986

[Hormonal changes during incremental exercise in athletic women].

Recently, the number of women who participate in strenuous sports has increased rapidly. The evidence indicating a causal relationship between athletic activity and increased incidence of menstrual dysfunction has led to increased interest. Five basketball players who are among the top players in Japan were subjected to an investigation of the endocrinological responses effected by incremental exercise using a cycle ergometer. Serum levels of FSH and LH decreased significantly in the follicular phase, but there was no change in the luteal phase. Estradiol was seen to increase significantly in the luteal phase but no change occurred in the follicular phase. Progesterone did not show a significant change during exercise. Although TSH did not show any significant change, prolactin showed a significant increase in both phases. These results suggest that strenuous daily training leads to a frequent increase of prolactin in athletic women and this frequent increase of prolactin may be one of the major factors in causing menstrual dysfunction.

Adult↗
PubMed1986

[Results of brachytherapy of tongue cancer].

One hundred thirty-two patients with primary cases of squamous cell carcinoma of the tongue treated at National Sapporo Hospital from 1972 to 1982 were reviewed. Most primary sites were treated with interstitial needle implant with or without external beam irradiation. The local control rate by needle implant for the primary tongue lesions was 85.5%. That for the single plane implant was especially notable at 92.5%. The cumulative five-year survival rate was 92.8% in stage, I, 74% in stage II, 53.2% in stage III, 12.5% in stage IV and 64% overall.

Adult↗
PubMed1986

[Results of several combination modalities for maxillary cancer].

Two hundred forty-six patients with the histologically proved squamous cell carcinoma of the maxillary sinus were treated at the Department of Radiology, National Sapporo Hospital, with various combined modes of surgery, irradiation and chemotherapy. Four combination modalities were used from 1966 to 1983. One hundred sixty-three (66.3%) patients were men and 83 (33.7%) were women. Five-year survival was 41.0% in T2 (16 cases), 22.3% in T3 (176 cases) and 15% in T4 (53 cases). In 72 cases treated since 1978 with tumor reduction as completely as possible, five-year survival was 43.5%. We recommand tumor reduction as complete as is possible and 40-50 Gy irradiation.

Adult↗