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Biomedical subjects

A Ota

Publications and source records attributed to A Ota.

At least 109 records · Page 6Linked to original sources
PubMed1983

Sugar uptake during early ascosporulation in Saccharomyces cerevisiae.

The uptake rates of several sugars were examined in cells of Saccharomyces cerevisiae during early ascosporulation. The pH optimum of glucose uptake was about 7 both in the vegetative cells and in the cells after transfer to the sporulation medium. The glucose uptake rate of the cells 3 h after transfer to sporulation medium was about two-fold higher than that of vegetative cells. Uptake rates of glucose, mannose, and galactose increased during the first 3 h and then decreased slightly. The uptake rate of lactose increased throughout the 4 h period of observation, and the uptake rate of 2-deoxy-glucose was constant but at a very low level. Uptake rates of xylose and rhamnose, using the 3,5-dinitrosalicyclic acid method, were below detection levels.

Culture Media↗
PubMed1982

Enzyme activities during early ascosporulation in Saccharomyces cerevisiae.

1. Several enzyme activities were examined during the initial sporulating phase in Saccharomyces cerevisiae. 2. Catalase activity increased obviously after transfer to sporulation medium. 3. Catalase is probably considered to play an essential role in sporulation. 4. Both activities of inorganic pyrophosphatase and glycerol-2-phosphatase decreased. 5. Conditions necessary for sporulation were suggested.

Catalase↗
PubMed1982

Phagocytosis-connected oxygen consumption by peripheral leukocytes from patients with systemic lupus erythematosus.

The phagocytic activity of peripheral blood leukocytes was assayed by means of oxygen consumption in 28 patients with systemic lupus erythematosus (SLE) and 22 normal individuals. The method in which zymosan was added to a small volume of whole blood enabled us to assay quantitatively and rapidly both the phagocytosis-connected oxygen consumption and the opsonizing time. The degree of oxygen consumption by phagocytes from SLE patients was not significantly different from that in normals. Opsonizing time of zymosan by autologous serum in SLE patients did not differ from that in normals either. It should be emphasized, however, that the opsonizing time of zymosan in SLE patients was inversely correlated with serum complement level, especially C3 level (coefficient of correlation = -0.76, p less than 0.001). This raises the possibility that the phagocytosis may be delayed in SLE patients with low titers of C3.

Adolescent↗
PubMed1982

CA2+ uptake in an asporogenous mutant strain of Bacillus megaterium.

Some properties of Ca2+ accumulation were examined in Bacillus megaterium mutant 3-12 which cannot sporulate owing to a lack of dipicolinic acid. The steady-state intracellular content of Ca2+ was half-saturated at 0.06 mM. Ca2+ was accumulated up to its plateau in 30 min. There were two classes of Ca2+ accumulation, high-affinity and low-affinity, both of which were mostly energy-dependent, and there was a small amount of energy independent Ca2+ binding. Exchange of Ca2+ accumulated in the cells for the external Ca2+ in the medium was observed. The highest rates of exchange were evident in the cells harvested when Ca2+ accumulation reached its peak.

Bacillus megaterium↗
PubMed1982

[Computer analysis of wo-dimensional echocardiogram for the quantitative evaluation of left ventricular asynergy in myocardial infarction].

Quantitative assessment of left ventricular asynergy in myocardial infarction was made by computer analysis of the two-dimensional echocardiogram. Short-axis cross-sectional images of the left ventricle at the levels of the mitral valve, papillary muscle and apex were recorded by a phased array sector scanner in 20 patients with myocardial infarction and ten normal controls. End cardial and epicardial outlines at end-diastole and end-systole were traced and analyzed by a computer system. Short-axis cross-sectional images of the left ventricle were divided equally into octants and analyzed with a fixed external reference system, using the center of gravity of end-diastolic left ventricular cavity and the axis intersecting this and the right side of the posterior interventricular septum as the reference point and line. Segmental hemiaxis, area, wall thickness and those changes during cardiac cycle were measured and calculated in each octants. Regional contractility of the left ventricle was evaluated by systolic percent change of segmental hemiaxis, area and wall thickness. These parameters were significantly reduced in the infarcted segments documented by left ventriculography and electrocardiography. The area method is better than the hemiaxis system in both reproducibility and variability. The center of gravity of the left ventricular cavity determined by the computer shifted slightly towards the anterior wall during systole in normal subjects, possibly reflecting anterior swinging motion of the entire heart. The center of the gravity of the left ventricular cavity in myocardial infarction showed the tendency to shift towards the infarcted region, suggesting the possibility that the location of asynergic area can be detected by determining the direction of the gravity center shift during systole in patients with a single infarction. This finding gives a basis of using the fixed reference system for the detection of asynergy. The use of computers for the analysis of short-axis two-dimensional echocardiographic images is very useful for the quantification of regional contractility of the left ventricle in a clinical setting.

Computers↗
PubMed1980

Oxidative phosphorylation coupled with nitrate respiration. IV. Replacement of soluble fraction from Escherichia coli, Pseudomonas aeruginosa and Mycobacterium avium.

The optimal pH range was from 7.0 to 7.5 in oxidative phosphorylation coupled to nitrate reduction. A cell-free extract of Escherichia coli showed weak myokinase activity. Oxidative phosphorylation coupled to nitrate reduction occurred with fractions of cell-free extracts of Mycobacterium avium. Soluble and particulate fractions separated from the cell-free extract of the organism were necessary for oxidative phosphorylation coupled to nitrate reduction. Each soluble fraction could be replaced by that obtained from another organism, e.g. Escherichia coli, Pseudomonas aeruginosa, and Mycobacterium avium. This suggests the existence of coupling factors common to these soluble fractions, and the possibility that the coupling factors are ATPase and components of the ATP-Pi exchange reaction. The P/NO3- ratio depended more on soluble fractions than on particulate fractions. Both phosphorylation and nitrate reduction activity were reduced by washing particulate fractions of Escherichia coli with 0.1 M KCl, while the P/NO3- ratio slightly increased.

Adenine Nucleotides↗