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Biomedical subjects

H Okada

Publications and source records attributed to H Okada.

At least 1,297 records · Page 72Linked to original sources
PubMed1975

Autoradiographic and fluorescent staining studies of bone marrow chromosomes from a patient with acute granulocytic leukemia.

Results of cytogenetic studies of a patient with acute granulocytic leukemia are described. The modal number of chromosomes in cells from bone marrow samples was 43; the karyotype was characterized by missing chromosomes in groups B, C, and E. According to successive studies of the same metaphases by fluorescent staining and autoradiographic techniques, the labeling pattern of chromosomes in leukemic cells was generally similar to those observed in normal cultured leukocytes, whereas the fluorescent pattern of leukemic chromosomes was rather indistinct, and the bright fluorescent pattern of the Y chromosome was not apparent.

Acute Disease↗
PubMed1975

Photolytic degradation of alpha-[(dibutylamino)methyl]-6,8-dichloro-2-(3',4'-dichlorophenyl)-4-quinoline methanol: an experimental antimalarial.

A study of the effects of various storage conditions on the rate and products of degradation of the quinoline methanol antimalarial agent, alpha-[(dibutylamino)methyl]-6,8-dichloro-2-(3',4'-dichlorophenyl)-4-quinoline methanol, was undertaken. The degradation was followed by high-pressure liquid chromatography and TLC in oxygenated and deoxygenated methanol, ethanol, chloroform, and chloroform-heptane mixtures under UV and laboratory fluorescent lighting irradiation, as well as in the absence of light. The kinetics of degradation confirmed the major catalyzing factor to be UV irradiation. The compound was stable in the absence of light and reasonably stable under fluorescent lighting both in the presence and absence of oxygen. The degradation resulted in a major product, 6,8-dichloro-2-(3',4'-dichlorophenyl)-4-quinoline-carboxaldehyde, whose structure was confirmed by elemental analysis and IR, NMR, and mass spectral data.

Antimalarials↗
PubMed1975

Oxidative degradation of squalene by Arthrobacter species.

An organism isolated from soil and identified as Arthrobacter sp. was studied for its squalene degradation. The degradation product from squalene, which accumulated in the culture broth, was isolated and identified as trans-geranylacetone by mass spectrometry, gas chromatography, infrared spectrometry, and nuclear magnetic resonance spectrometry. Addition of a high concentration of K2HPO4 to the culture medium resulted in accumulation of fairly large amounts of carboxylic acids in addition to geranylacetone. These carboxylic acids were identified as isovaleric, beta,beta'-dimethylacrylic, geranic, and (plus)-(R)-citronellic acids. Among these acids, alpha,beta-saturated carboxylic acids were found to be predominant in quantity.

Arthrobacter↗
PubMed1975

Genes affecting the productivity of alpha-amylase in Bacillus subtilis Marburg.

Genetic control of alpha-amylase (alpha-1,4-glucan glucanohydrolase, EC 3.2.1.1.) production by Bacillus subtilis 168 was studied from the standpoint that alpha-amylase production by bacteria is dependent on a long-lived messenger ribonucleic acid and obeys the following equation: E = kappa integral of X-DT where x = cell mass at time t, E = alpha amylase produced, t = culture time, and kappa = productivity constant. So a productivity constand (kappa) is obtained from the slope of the straight line plot of alpha-amylase formed versus the total mass of cells accumulated over that time during the culture process. The following results were obtained. (i) Two sequential mutants, derived from the 168(kappa = 20) strain and having improved alpha-amylase productivity (168 leads to 196), were analyzed for their serine and metal protease production. Strain 128 (kappa = 40) produced half the amount of both proteases, but strain 196 (kappa = 60 similar to 80) produced 20 times that in the original strain. (ii) Amy+ transformants, using the 196 strain as the other three had higher productivity (kappa = 37 similar to 46). These transformants (J71, J47, groups. Seventy-one of 74 Amy+ transformants had a kappa value of 21.0 plus or minus 2.1 and the other three had higher productivity (kappa = 37 similar to 46). These transformants (J71,J47, and J10) produced levels of serine and metal proteases 20 times higher than the other transformants. (iii) Strains 196, J71, J47, and J10 were found to be nonmotile and resistant to phage PBS1, whereas other strains, including strains 168, 128, 3 revertants of strain J71 and 2 revertants of strain 196, were all motile and sensitive to the phage. (iv) Strains 196 and J71 were nonflagellated under electron microscopic observation but strain 168, 128 and a revertant of J71 were flagellated. From the above experimental results, the existence of a quality controlling gene (amyB) was deduced, which is loosely linked to the structural gene and controls productivities of alpha-amylase and proteases, and flagellation. The probable existence of another regulatory gene, amyC, is also discussed.

Amylases↗
PubMed1975

Activated guinea-pig C3 and the immune adherence receptor (a complement receptor) on cell membranes.

By treating C3 with purified C1, C4 and C2 in the fluid phase, haemolytically inactive C3 was prepared. This was shown to bind to human erythrocytes by use of radio-labelled (Fab')2 antibody to guinea-pig C3. The activated C3 preparation inhibited immune adherence between EAC43 and human erythrocytes. These findings indicate that the activated C3 attaches to the immune adherence receptor on human erythrocytes. In addition the fluid-phase activated C3 adhered to thymus cells and sheep erythrocytes, whereas EAC43 did not. Thus the immune adherence receptor may be present on so called immune adherence-negative cells, but in insufficient concentration to form rosettes with EAC43.

Animals↗