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Biomedical subjects

H Noda

Publications and source records attributed to H Noda.

At least 343 records · Page 19Linked to original sources
PubMed1982

Structure of bacterial fatty acid synthetase from Brevibacterium ammoniagenes.

Hydrodynamic measurements and a cross-linking study with dimethyl suberimidate have shown that the native fatty acid synthetase from Brevibacterium ammoniagenes is a hexameric protein having a molecular weight of 1.56 . 10(6). The subunits of the enzyme are identical in size (Mr 2.6 . 10(5). The negatively stained fatty acid synthetase had an electron microscopic image of ellipsoidal structure with major and minor axes approximately equal to 270 A and 180 A, respectively. The electron microscopic image is similar to that of the yeast enzyme, which is quite distinct from the B. ammoniagenes enzyme with respect to the subunit composition. The inactivated enzyme prepared by dialysis against a lower ionic strength solution was partially reactivated by raising the ionic strength. Ellipsoidal images similar to those of the native enzyme were found in the electron micrograph of the reactivated enzyme. Sucrose density gradient centrifugation of the reactivated enzyme sample showed that the active component had almost the same sedimentation coefficient as the native hexamer. These results indicate that the enzyme is active only in its hexameric state.

Amino Acids↗
PubMed1982

Eye position signals in the flocculus of the monkey during smooth-pursuit eye movements.

1. Discharges of Purkinje cells and mossy fibres were recorded from the flocculus of monkeys trained to fixate a small visual target and to track the target when it moved slowly.2. Discharges of Purkinje cells changed tonically with shifts of gaze. Firing rates were linearly related to eye positions for either the entire or more than half the eye-position range in 12.6% of Purkinje cells tested (76/603 units).3. The eye position-related activity (position component) was observable in these cells also during smooth-pursuit eye movements. It was typically seen during slow eye movements (velocities less than 10 deg/s) but became undetectable during high velocity movements (faster than 50 deg/s).4. The position component became prominent when smooth pursuit was executed at the preferred loci of the individual cells. In the majority of the cells tested at their preferred loci, the position component was observable to a relatively high frequency, such as 0.5 Hz (+/- 10 deg; peak velocity 31 deg/s).5. Forty-five mossy fibre units showed saccade-related bursts and position-related intersaccadic tonic activity during steady eye position. In each unit, the position component was found only during fixations within a specific range of eye positions. During fixations outside these regions, all position-related mossy fibres were completely silent.6. During sinusoidal smooth-pursuit eye movements, the mossy fibres also displayed cyclic modulations in activity. All fibres discharged with eye movements in one direction and were silent during eye movements in the other direction.7. Saccade-related bursts from mossy fibres led the onset of saccades, ranging from 0 to 19 ms with a mean lead-time of 6.9 ms. This observation negates the possibility that the position-related signals might represent proprioceptive impulses from the stretch receptors of the extraocular muscle.

Action Potentials↗
PubMed1982

Dynamic responses of active and inactive renin and plasma norepinephrine during exercise in normal man.

Active and inactive plasma renin, plasma angiotensin II, and plasma norepinephrine were measured during graded exercise. Five health subjects exercised on bicycle ergometer at three different loads (50, 70, and 100% of maximal oxygen uptake). Active plasma renin and plasma angiotensin II were elevated significantly during graded exercise, but plasma inactive renin decreased during the heaviest exercise; the mean ratio of active renin to total renin increased from 57 to 92% after the heaviest load. Plasma norepinephrine was also elevated during graded exercise. There is a positive correlation between plasma norepinephrine and active plasma renin during graded exercise (r = 0.916, p less than 0.01). Similar norepinephrine and active renin responses to graded exercise suggest that the mechanism(s) for activation of inactive renin and the release of active renin from the kidney may be partially related to sympathetic nervous system activity.

Adult↗
PubMed1982

Hemodynamic and endocrine changes associated with captopril in diuretic-resistant hypertensive patients.

To evaluate the therapeutic efficacy of oral angiotensin-converting enzyme inhibition with low-dose (average 30 mg/day) captopril in diuretic-resistant hypertension, its long-term cardiocirculatory action was determined by dye-dilution method and venous-occlusion forearm plethysmography in 11 uncontrolled patients taking a thiazide diuretic. Significant declines in mean blood pressure (average 12.4 +/- 1.4 percent) and systemic vascular resistance (28.7 +/- 3.2 percent) accompanied an increase in cardiac output (24.8 +/- 4.1 percent). Forearm vascular resistance (16.0 +/- 2.7 percent) decreased considerably, but the decrease in limb vascular resistance did not parallel the fall in systemic vascular resistance in magnitude (p less than 0.01), indicating that arteriolar dilatation occurred on a selective basis. Plasma renin activity increased after therapy as plasma aldosterone levels consistently fell, while plasma norepinephrine concentrations were not changed. There was a direct correlation between pretreatment plasma renin activity and the magnitude of the decline in systemic vascular resistance (p less than 0.05). These findings suggest that the inhibition of angiotensin-converting enzyme with captopril in diuretic-resistant hypertensive patients improves cardiocirculatory function through selective dilatation. The reordering of regional blood flow, which appears to result from release of angiotensin-mediated vasoconstriction as well as the suppression of aldosterone, may underlie the prolonged benefit observed in these patients. This oral vasodilator in very low dose appears to represent an effective adjunct for the treatment of hypertension refractory to diuretics.

Adult↗
PubMed1982

Antibody responses of horses to equine influenza viruses during a postepizootic period in Japan.

The antibody responses to equine influenza viruses were investigated during a postepizootic period of the disease. Serum samples were collected from a total of 128 horses on three occasions during the years 1967-77. No significant increase of hemagglutination-inhibition antibody titers to subtypes 1 and 2 of equine influenza virus were detected in any of the sera tested. The maternal hemagglutination-inhibition antibody titers of foals decreased over a four month interval. A marked increase of the titers was recognized in only the equine influenza virus vaccinated horses. These findings suggest that equine influenza virus was not prevalent in the horse populations during the observation period. In such conditions, the dissemination of equine influenza viruses in the horses is discussed in relation to introduction of the disease from abroad. We also examined whether the doctrine of original antigenic sin, an immunological phenomenon recognized in human influenza, was applicable for equine influenza. However, no marked increase of hemagglutination-inhibition antibody titer to the primary infecting subtype in the 44 horses was observed after administration of the heterologous subtype vaccine.

Animals↗