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Biomedical subjects

H Ohashi

Publications and source records attributed to H Ohashi.

At least 559 records · Page 31Linked to original sources
PubMed1978

3-Hexulosephosphate synthase from Methylomonas aminofaciens 77a. Purification, properties and kinetics.

3-Hexulosephosphate synthase (D-arabino-3-hexulose 6-phosphate formaldehyde lyase) was purified from an obligate methylotroph, Methylomonas aminofaciens, to homogeneity as judged by polyacrylamide gel electrophoresis and analytical ultracentrifugation. The molecular weight was determined to be 45 000-47 000 by sedimentation velocity and gel filtration. The enzyme appears to be composed of two identical subunits (Mr = 23 000). A bivalent cation is required for the activation and stabilization of the enzyme. The enzyme is specific for formaldehyde and D-ribulose 5-phosphate. The optimum pH is 8.0 (isoelectric point, pH 5.1) and the optimum temperature is 45 degrees C. Initial velocity studies are consistent with a sequential mechanism. The Michaelis constants are 0.29 mM for formaldehyde and 0.059 mM for D-ribulose 5-phosphate.

Aldehyde-Lyases↗
PubMed1977

A case of musicogenic epilepsy.

1) A case of musicogenic epilepsy or psychomotor seizures supervening whenever the patient hears a certain tume has been presented. 2) The EEG features of the seizure are such as are often seen in psychomotor seizures. 3) Auditory evoked response may be left out of consideration. 4) There is no appreciable relationship between the disease and the life history of the patient. The attempt of our patient to cure herself by making use of conditioned reflex proved to be a failure. The patient is more liable to the disease when she is on the strain while hearing a tune. 5) Our consideration of the mechanism of the disease has led to the presumptive conclusion that hyperacusis, conditioned reflexes and the impact of life history may be involved, and the fragility of the memory function of the temporal lobe underlie the genesis of the disease.

Aged↗
PubMed1977

Hydrolysis of lactose by immobilized microorganisms.

Cells of Lactobacillus bulgaricus, Escherichia coli, and Kluyveromyces (Saccharomyces) lactis immobilized in polyacrylamide gel beads retained 27 to 61% of the beta-galactosidase activity of intact cells. Optimum temperature and pH and thermostability of these microbial beta-galactosidases were negligibly affected by the immobilization. Km values of beta-galactosidase in immobilized cells of L. bulgaricus, E. coli, and K. lactis toward lactose were 4.2, 5.4, and 30 mM, respectively. Neither inhibition nor activation of beta-galactosidase in immobilized L. bulgaricus and E. coli appeared in the presence of galactose, but remarkable inhibition by galactose was detected in the case of the enzyme of immobilized K. lactis. Glucose inhibited noncompetitively the activity of three species of immobilized microbial cells. These kinetic properties were almost the same as those of free beta-galactosidase extracted from individual microorganisms. The activity of immobilized K. lactis was fairly stable during repeated runs, but those of E. coli and L. bulgaricus decreased gradually. These immobilized microbial cells, when introduced into skim milk, demonstrated high activity for converting lactose to monosaccharides. The flavor of skim milk was hardly affected by treatment with these immobilized cells, although the degree of sweetness was raised considerably.

Animals↗
PubMed1977

Non-cholinergic, excitatory junction potentials in smooth muscle of chicken rectum.

Muscle strips from the longitudinal or circular muscle of the chicken rectum were used to determine changes in membrane potential during field stimulation as recorded using the sucrose-gap method. Stimulation with single square pulses (0.1 msec duration) evoked junction potentials elicited by transmitter released from nerve endings. Facilitation in amplitude of excitatory junction potentials (EJPs) was seen during repetitive stimulation in the longitudinal muscle, but in the circular muscle, EJPs reduced. Neither atropine nor hyoscine (up to 10(-5) g/ml) reduced EJPs. These drugs abolished the depression of EJPs in the circular muscle produced by repetitive stimulation. Anticholinesterases (2 X 10(--8)-2 X 10(-6) g/ml) reduced the EJPs. The inhibitory effect was produced without affecting the membrane resistance of smooth muscle and was completely antagonized by atropine (1-(-6) g/ml). Drugs that abolish the adrenergic functions did not affect the EJPs. These results suggest that nerves involved in the EJPs are non-cholinergic and non-adrenergic in nature, and the motor transmission to the smooth muscle may be inhibited by cholinergic nerves, presumably presynaptically.

Acetylcholine↗