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Biomedical subjects

Y Ishida

Publications and source records attributed to Y Ishida.

At least 721 records · Page 40Linked to original sources
PubMed1980

Characteristics contractile response to the calcium ionophore, A23187, in guinea-pig vas deferens.

1. In the guinea-pig isolated vas deferens, the calcium ionophore, A23187, initially caused a phasic contraction followed by rhythmic activity. 2. Treatment with atropine, phentolamine, tetrodotoxin and reserpine modified neither of the components of the contraction induced by the ionophore. Verapamil and nifedipine abolished the rhythmic activity but had no effect on the phasic contraction. 4. In a calcium-free solution, both components of the contraction were abolished. 5. It is suggested that A23187 is able to cause contraction by a direct action on the smooth muscle of guinea-pig vas deferens.

Animals↗
PubMed1980

Pyrimidine 5'-nucleotidase deficiency: studies of five cases in two Japanese families.

Two new families with red cell pyrimidine 5'-nucleotidase (P5N) deficiencies were found in Japan. The enzyme activities were 4.8% in case 1 and 9.7% in case 2. The propositi showed characteristic hemolytic anemia with market basophilic stippling, increased reduced glutathione content and accumulation of pyrimidine nucleotides in the red cell. High Michaelis constants for cytidine monophosphate, normal thermostability, abnormal optimum pH in both cases, and normal electrophoretic mobility in case 1 and slower mobility in case 2 were shown, suggesting that the cause of P5N deficiency, at least in these cases, is due to the structural gene mutation.

5'-Nucleotidase↗
PubMed1980

A combined system for the study of glutathione metabolism in erythrocytes.

A combined system for measuring glutathione stability, hexose monophosphate pathway activity, glutathione synthesis, glucose consumption and lactate formation in erythrocytes has been devised. By this method the results were obtained from the blood samples of six glucose 6-phosphate dehydrogenase deficiencies, one glucose phosphate isomerase deficiency and two pyruvate kinase deficiencies. These results indicate that one abnormal enzyme may exert its influence on the other several enzyme systems and that it is valuable to investigate the metabolism of erythrocytes using this system in different erythroenzymopathies as well as different variants of one enzyme deficiency.

Anemia, Hemolytic, Congenital Nonspherocytic↗
PubMed1980

Interaction of cinepazide with adenosine on guinea-pig atria.

The negative inotropic effects of adenosine and adenine nucleotides, such as ATP and cAMP, on guinea-pig atria were selectively and dose-dependently augmented by cinepazide in concentrations insufficient to produce any effect alone (3 X 10(-5) M-3 X 10(-4)M). Adenosine (10(-5) M, 10 microCi) was degraded to inosine and hypoxanthine during incubation with atrial tissue. Cinepazide (3 X 10(-4) M) retarded the degradation of adenosine, and the formation of inosine and hypoxanthine. Incubation of the atrial tissue with adenosine (8.1 X 10(-9) M, 0.1 microCi) resulted in accumulation of 3H-activity. Cinepazide (3 X 10(-5) M-3 X 10(-4) M) inhibited this accumulation. These results suggest that cinepazide potentiates the negative inotropic effect of adenosine on guinea-pig atria by preventing both its degradation by deaminase and its accumulation by atrial tissue.

Adenosine↗
PubMed1979

Red cell enzyme activities and properties of mutant pyruvate kinase after long-term storage of red cells in liquid nitrogen.

After 8 months of storage of normal red cells in liquid nitrogen, red cell enzyme activities were essentially unchanged, except for triose phosphate isomerase which was reduced by about half. Mutant pyruvate kinase (PK), PK Tokyo I, showed no changes in kinetic or electrophoretic properties after 8 months of storage. These findings indicate that red cells stored for a long term in liquid nitrogen can still be used for the study of mutant PK.

Blood Preservation↗
PubMed1979

A case of generalized amyloidosis associated with cyclic neutropenia.

A case of generalized amyloidosis associated with cyclic neutropenia is presented. A 24-yr-old female with cyclic neutropenia died from intestinal obstruction caused by necrosis and perforation of the small intestine. Post-mortem examination revealed generalized amyloidosis involving almost all organs. Amyloid deposits were prominent, especially in the alimentary tract, kidneys, spleen, and small blood vessels. As has been suggested in gray collie dogs with congenital cyclic neutropenia known to develop secondary amyloidosis in adulthood, an increase of antigenic stimulation during the intermittent bouts of acute infections may be one of the factors responsible for the development of secondary amyloidosis in this case. Although the association of amyloidosis and cyclic neutropenia in man has rarely been described, it is probable that amyloidosis is not a rare complication of human cyclic neutropenia, considering that patients with this hematologic disorder are chronically exposed to excessive antigenic stimulation.

Adult↗
PubMed1979

Possible involvement of prostaglandins in the action of ATP on guinea-pig uterus.

ATP and other adenine derivatives, such as AMP and adenosine, at concentrations above 10(-6) M induced dose-dependent contractions of guinea-pig uterine strips. Treatment of the strips with nonsteroidal anti-inflammatory drugs, such as indomethacin, aspirin and phenylbutazone, at concentrations of 10(-6) to 10(-4) M irreversibly inhibited the contractions, without affecting those caused by acetylcholine and bradykinin. Arachidonic acid (10(-8)-10(-6) g/ml) and prostaglandins (E1, E2 and F2 alpha, 10(-9)-10(-7) g/ml) restored the inhibited uterine response to ATP, but the inhibition was reinstated on washing out of the arachidonic acid or prostaglandins. Furthermore, the prostaglandin antagonists polyphloretin phosphate (3 x 10(-5)-3 x 10(-4) g/ml) and SC 19220 (10(-6)-3 X 10(-5) M) selectively suppressed the action of ATP. In addition to the prostaglandin antagonists, 2,2'-pyridylisatogen, reported to be an ATP antagonist, at concentrations of 10(-6) to 3 x 10(-5) M selectively inhibited the response of uterine strips to ATP. These results suggest the involvement of prostaglandins in the actions of ATP and other adenine derivatives on guinea-pig uterine tissue and provide further evidence for ATP-stimulated prostaglandin formation in smooth muscle.

Adenine Nucleotides↗