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Biomedical subjects

H Noda

Publications and source records attributed to H Noda.

At least 361 records · Page 20Linked to original sources

Comparison of the effects of a multi-component vaccine and a formalin-killed cell vaccine on protection against enzootic of hemorrhagic pneumonia due to Pseudomonas aeruginosa in mink.

Effectiveness of a multi-component vaccine consisting of the common antigen (OEP) derived from Pseudomonas aeruginosa strain N 10 (serotype E) and toxoids of protease and elastase was compared with that of formalin-killed cells of strain N 10 on protection against enzootic of hemorrhagic pneumonia due to P. aeruginosa in mink. One administration of the multi-component vaccine (100 microgram each of OEP, protease toxoid and elastase toxoid) clearly prevented enzootic of hemorrhagic pneumonia due to P. aeruginosa (serotype G) in mink, while a vaccination of formalin-killed cells was much less effective in preventing an epidemic. The difference in mortality rates between two vaccines was remarkable.

Animals↗

F-Protein, a myofibrillar protein interacting with myosin.

F-Protein has an amino acid composition distinctively different from those of myofibriller proteins so far reported to be of similar chain weight: M-protein component II, alpha-actinin, and AMP deaminase. Its molecular weight was estimated to be 121,000 by sedimentation equilibrium in 0.3 M KCl, 10 mM potassium phosphate, pH 6.5. Its binding to myosin was inhibited by C-protein. It reduced the effect of C-protein on the assembly reaction of myosin in vitro.

Amino Acids↗

Interaction of C-protein with myosin.

The effect of C-protein on the assembly reaction of myosin was studied by flow birefringence, electron microscopy, and ultracentrifugation. Myosin filaments were formed by dilution to a lower ionic strength. Thinner filaments of 70-110 A in diameter were formed in the presence of C-protein. When dilution was effected by moderately slow dilution (dilution time of 0.5-2 min) or by stepwise dilution, C-protein favored the formation of longer filaments. When dilution was effected by even slower dilution (dilution time above 2 min), C-protein favored the formation of shorter filaments. Longer filaments formed by slow dilution incorporated more C-protein than shorter ones formed by faster dilution. Addition of C-protein to a solution of myosin filaments caused association of the filaments into longer filaments. The elongation effect was slower and stronger for longer filaments.

Animals↗

Discharges of Purkinje cells and mossy fibres in the cerebellar vermis of the monkey during saccadic eye movements and fixation.

1. Discharges of Purkinje cells and of presumed mossy fibres were extracellularly recorded from vermal lobules VI and VII of two monkeys during saccadic eye movements and fixation. Among the units showing changes in activity in relation to either saccades or eye position, eighty-four units were identified as mossy fibres and ninety-one units were Purkinje cells.2. Based on the discharge patterns associated with saccades, mossy fibre units were classified into long-lead burst, burst, and burst-tonic units. The long-lead burst units (twenty-eight units) started firing long before the saccades, the discharge consisting of a prelude (average lead time: 160 msec) and a burst (average lead time: 16 msec). In twenty-two units the saccade-related bursts showed a directional preference. The burst units (thirty-seven units) started firing slightly before the saccade onset (average lead time: 7.4 msec) and thirteen units showed directional preference. The bursts in burst-tonic units (thirteen units) had an average lead time of 0.2 msec.3. Among the ninety-one Purkinje cells, eighty-eight cells showed bursts associated with saccades. Three units paused for all directions of saccades.4. Seventy-one units out of the eighty-eight burst Purkinje cells showed bursts beginning approximately at the saccade onset (average lead time: 0.6 msec) and lasting throughout the saccade. The durations of bursts and saccades were highly correlated (correlation coefficients ranging from 0.70 to 0.88).5. In the remaining seventeen burst Purkinje cells, the bursts followed the saccade onset (average delay: 32 msec). The bursts started approximately 40 msec before the end of a saccade and persisted on the average 70 msec after its completion. Peak firing rate occurred with a close temporal relation to the end of the saccade.6. The tonic activity in nineteen mossy fibres and five Purkinje cells changed with eye positions. In the nineteen mossy fibres, there were thirteen burst-tonic and six tonic units. The activity in the five Purkinje cells was a linear function of horizontal eye position.

Action Potentials↗

Formation of a transplacental mutagen, 1,3-Di(4-sulfamoylphenyl)triazene, from sodium nitrite and sulfanilamide in human gastric juice and in the stomachs of hamsters.

1,3-Di(4-sulfamoylphenyl)triazene was abundantly produced by incubation of sulfanilamide (SA) and NaNO2 in human gastric juice. This reaction also occurred in acetate buffer (pH approximately 4) at 37 degrees C as well as in hydrochloric acid (pH < 1) under ice cooling, with the product forming in almost the same amount. This phenomenon indicated the broad range of conditions under which the reaction occurs. The intragastric formation of this triazene was also demonstrated in Syrian golden hamsters by the concurrent administration of SA and NaNO2. Mutants resistant to 8-azaguanine were induced in a dose-dependent manner in the culture of embryo cells that were derived from pregnant hamsters 24 hours after ip injection of this triazene.

Animals↗

Target velocity signals of visual tracking in vermal Purkinje cells of the monkey.

Discharges of Purkinje cells were recorded from the vermis, lobules VI and VII, of a monkey trained to track a visual target. When the monkey tracked a sinusoidally oscillating target, cellular activity changes in phase with the velocity signal of the eye movement. When the monkey fixated a stationary point, almost identical modulation in activity occurred, reflecting the velocity signal of the motion of the retinal image of the target. The data suggest that the vermis participates in the control of smooth pursuit eye movements by providing the oculomotor system with the actual target velocity information which is the sum of eye velocity and retinal image velocity signals.

Action Potentials↗

Experimental infection of mink with influenza A viruses. Brief report.

Mink were found to be susceptible to the intranasal inoculation of human, swine, equine and avian influenza A viruses. The viruses were recovered until the 7th post inoculation (p.i.) day from the respiratory tract. The inoculated mink showed antibody response against these viruses. Contact infection in mink with A/Kumamoto/22/77 (H3N2) was possible.

Animals↗

Purification and properties of phosphoglycerate kinase from Thermus thermophilus strain HB8.

(1) A glycolytic enzyme, phosphoglycerate kinase [EC 2.7.2.3], was purified from cells of an extreme thermophile, Thermus thermophilus strain HB8. The enzyme was resistant to heat, and no loss of activity was observed after incubation for 10--20 min at 79 degrees C. (2) Catalytic properties such as pH optimum (pH 6--8.5), kinetic parameters (Km=0.28 mM for ATP, 1.79 mM for glycerate 3-phosphate), substrate specificity and inhibitors of the enzyme were investigated and compared with those of phosphoglycerate kinase from other sources. (3) The enzyme protein consists of a single polypeptide chain of molecular weight 44,600. The isoelectric point is 5.0 The amino acid composition of the enzyme was studied. The contents of ordered secondary structures were estimated to be 29% alpha-helix and 11% pleated sheet from the circular dichroic spectrum of the enzyme protein. (4) The fluorescence spectrum of the enzyme protein showed an emission maximum at 320 nm when excited at 280 nm. The quantum yield was 0.19. Tryptophyl fluorescence was not quenched, in contrast to the fluorescence reported for yeast phosphoglycerate kinase.

Amino Acids↗

Kietics of thermal unfolding and refolding of thermostable phosphoglycerate kinase.

The kinetics of denaturation by guanidine hydrochloride (GuHCl) of a thermostable phosphoglycerate kinase (PGK) extracted from Thermus thermophilus and of yeast PGK at neutral pH were studied by circular dichroism. Denaturation by GuHCl proceeded as a first-order reaction. The activation free energy of the denaturation reactions (delta Gf not identical to ) in the absence of GuHCl was estimated to be 32.7 kcal/mol for T. thermophilus PGK and 27.9 kcal/mol for yeast PGK (at 25 degrees C). Measurements of the rate constants at various temperatures indicated that delta Gf not identical to has maximum values at 29 degrees C for T. thermophilus PGK and at 20 degrees C for yeast PGK, and that the temperature dependences of delta Gf not identical to, delta Hf not identical to, and delta Sf not identical to for T. thermophilus PGK are smaller than those of yeast PGK. Values of delta Sf not identical to for thermal denaturation for both PGK's are approximately 200 e.u.

Calorimetry↗

The role of the flocculus of the monkey in saccadic eye movements.

1. Purkinje cell discharges were recorded from the flocculus of monkeys either spontaneously making saccadic eye movements (saccades) or trained to fixate a small visual target presented on a tangent screen. In the trained monkeys, saccades of known magnitude and direction were induced by changing the position of the fixation target. 2. Among 513 Purkinje cells, 343 units (66.9%) paused during saccades in all directions (286 units) or in particular directions (57 units). In most units, there were intimate temporal relationships between the beginnings of pauses and saccades, and between the ends of pasuses and saccades. 3. The pause in activity preceded saccades by an average of 9.6 msec, with a maximum lead time of 30 msec. In a fraction of the units (7.6%), the pause started after the onset of saccades. 4. There were 104 units (20.3%) which showed bursts during saccades in all directions (eighty-two units) or in particular directions (twenty-two units). 5. In sixty-six units (12.8%) a burst was associated with saccades in one direction and a pause in the opposite direction. 6. The burst in the burst and burst-pause units preceded saccades by an average of 3.8 msec. There was no significant difference in the lead times between these two groups of units. 7. There was a linear relationship between the duration of the pause in Purkinje cell activity and that of the accompanying saccade. A linear relationship was also seen between the pause duration and the magnitude of saccade.

Action Potentials↗

The role of the flocculus of the monkey in fixation and smooth pursuit eye movements.

1. Purkinje cell discharges were recorded from the flocculus of monkeys trained to fixate a small visual target and to track the target when moved slowly. 2. A striking feature of Purkinje cell activity during the steady fixation was a high rate of tonic discharges with regular interspike intervals. The average discharge rate in the whole population of Purkinje cells ranged from 37 to 145 spikes/sec. The coefficient of variation of the interspike intervals was typically smaller than 0.5 in most units. 3. In 43.9% of the Purkinje cells, tonic levels of activity changed by more than 20% of the average background activity with shifts of gaze. 4. In some Purkinje cells, especially in most burst-pause units, discharge rates during steady fixation were proportional to eye positions in one plane, implicating these cells as sources of eye position information to their target cells. 5. When the monkey tracked a sinusoidally oscillating target, the activity of some Purkinje cells was clearly modulated in phase with the eye velocity. 6. In the other Purkinje cells exhibiting smooth pursuit modulation, the activity curve appeared with a phase shift. When these cells were tested with sinusoidal target movements at different frequencies, but with a constant magnitude, the peak firing rates were proportional to the frequencies of the excursions, i.e. the velocities. 7. The flocculus thus provides the oculomotor system with eye position information during fixation and with velocity information during smooth pursuit and participates in the control of oculomotor functions stabilizing retinal images.

Action Potentials↗

Processing of eye movement signals in the flocculus of the monkey.

1. Extracellular recordings were made from afferents to the Purkinje cells of the flocculus of monkeys either spontaneously making saccadic eye movements (saccades) or trained to fixate a small visual target projected on a tangent screen. In the trained monkeys, saccades of known magnitude and direction were induced by changing the position of the fixation target. 2. Among a population of 108 units, eight were climbing fibres, seventy-one were mossy fibres, and twenty-nine were non-Purkinje cells. Based on their discharge patterns the latter two groups of units were categorized into one of four classes. 3. Long-lead burst units (twenty-two units) exhibited saccade-related discharges substantially before saccade onset (average: 113 msec). Most of these (twenty units) discharged for saccades in a particular direction, while the remainder exhibited discharges for saccades in all directions. All units were essentially silent between saccades. 4. Burst units (twenty-seven units) started discharging slightly before saccades (average: 6.9 msec). Discharges were associated with saccades in all directions (sixteen units) or in preferred directions (eleven units) and were not observed during periods of fixation. 5. Burst-tonic units (twenty-two units) were characterized by saccade-related burst and position-related intersaccadic tonic activity. 6. Tonic units (thirty-seven units) exhibited position-related tonic activity. The position-related activity in both burst-tonic and tonic units was observed only for fixation points within a specified region. The units were silent for fixation positions outside this region of preferred fixation.

Action Potentials↗