Biomedical subjects

K Sohmiya

Publications and source records attributed to K Sohmiya.

28 records · Page 2Linked to original sources

PubMed1993

Plasma and urinary heart-type cytoplasmic fatty acid-binding protein in coronary occlusion and reperfusion induced myocardial injury model.

The leakage of heart-type cytoplasmic fatty acid-binding protein (H-FABPc) from injured myocardial cells has been reported. We have previously proposed that its plasma and urinary levels could be used as an early indicator of myocardial injury and also reflect the severity of myocardial injury. To confirm this hypothesis, the time course of changes of the plasma and urinary H-FABPc was investigated during myocardial injury induced by coronary artery occlusion and reperfusion in dogs. The plasma elimination kinetics and urinary excretion kinetics of H-FABPc were also analysed in dogs which were given a bolus injection of exogenous H-FABPc. The distribution of circulating H-FABPc was determined in mice by whole-body autoradiography using 125I-labelled H-FABPc. In myocardial injury model, plasma and urinary H-FABPc level showed rapid increase after reperfusion. The elimination kinetic study revealed that H-FABPc was mono-exponentially cleared from the circulation. The elimination rate constant (Ke) was 0.0275 +/- 0.0094/min (mean +/- S.D., n = 7) and the disappearance half-time (t1/2) was 27.5 +/- 8.4 min (mean +/- S.D., n = 7). Exogenous H-FABPc appeared in urine soon after administration, with the peak level being at 6.9 +/- 2.0 min (mean +/- S.D., n = 7). Whole-body autoradiography also demonstrated that 125I-H-FABPc accumulated rapidly in the kidneys. This study demonstrated that H-FABPc leaked rapidly from injured myocardium and rapidly appeared in plasma and urine. Infarct size was closely correlated with the calculated H-FABPc release (r = 0.89, r2 = 0.80, P < 0.01, n = 7) and with the amount of the urinary H-FABPc (r = 0.94, r2 = 0.88, P < 0.01, n = 7). These data suggest that measurement of the H-FABPc levels in plasma and urine might be useful for the early detection of myocardial injury and also for the assessment of infarct size.

Animals↗

PubMed1992

Where does an anorthoscopic image appear?

Two experiments were performed to examine where anorthoscopic images appear. In Exp. 1, in which a narrow slit was used, the images were seen as spatially compressed, but also as spatially displaced along each direction of movement even when two patterns were moved simultaneously and in different directions. These results are incompatible with the retinal painting hypothesis. In Exp. 2, in which a wider slit was used, anorthoscopic images appeared immediately after a pattern entered and left the slit. The two images were considered to depend on temporal changes of parts of a pattern passing across left and right edges of the slit, respectively.

Female↗

PubMed1991

Serum and urinary human heart fatty acid-binding protein in acute myocardial infarction.

A competitive enzyme immunoassay (C-EIA) was developed for the measurement of serum and urinary levels of human heart fatty acid-binding protein (hh-FABP), and the appearance and time-course changes of hh-FABP levels were evaluated in patients with acute myocardial infarction (AMI). Control serum and urinary hh-FABP levels, which were determined in 86 serum and 42 urine samples from 86 patients without AMI, were found to range between 0 and 2.8 ng/mL. Serial determinations performed on 11 patients with AMI demonstrated that hh-FABP levels were significantly elevated in the first serum and urine samples obtained within 14 h of the onset of clinical symptoms. Two serum and 2 urine samples obtained only 1.5 h after the onset of symptoms already showed elevated hh-FABP levels, while in the same serum samples the activity of the myocardial-specific isoenzyme of creatine kinase (CK-MB) was still normal. Maximal serum and urinary hh-FABP levels appeared between 5 and 10 h after symptoms developed, and fell sharply towards normal thereafter. The hh-FABP levels in serum and urine both peaked earlier than the elevation of CK-MB activity in serum. The presence of hh-FABP in serum and/or urine seems to be a marker for myocardial damage and could be used as a useful tool for the early diagnosis of AMI.

Adolescent↗

PubMed1991

How does the visual system distinguish between illuminance and reflectance?

The experiments in which the strengths of pattern and of fusion differing in kind from brightness were used as measures indicated that the visual system could distinguish between illuminance and reflectance. From this result and an observation of gray papers by a microscope, it is assumed that luminance has two aspects, one refers to the macroscopic density of photons and another to the proportion of the reflected microscopic areas to the absorbed microscopic areas so that brightness constancy occurs in relation to each of the patterns of the various sizes from a macroscopic pattern visible to the naked eye to a microscopic pattern not visible. It is also mentioned that the strength of fusion is rare but promising as a measure for analyzing brightness.

Attention↗

PubMed1990

Method for representing quantitatively whole properties of visual patterns.

It was assumed that there is a variable, named "strength of fusion," underlying binocular fusion and rivalry. The strength of fusion is the resistance of the fused left- and right-eye patterns to separation. The first task was to obtain a measure of the strength of fusion and the second to examine the strength of fusion as a function of various differences of the patterns. The experiments showed that the angular separation only in the temporalward direction could be used as an appropriate measure of the strength of fusion and its value was maximum when the patterns were identical and decreased as the difference increased. This result supports the assumption about the strength of fusion.

Adult↗

PubMed1987

Fitting index of predominance based on periodicity of strengths of pattern and suppression in binocular rivalry.

The predominance of the strength of pattern over the strength of suppression during binocular rivalry has generally been defined as the percentage of total time of appearance. Is this fit for an index of the predominance? Theoretically, the strengths of pattern and suppression periodically oscillate throughout the observation period. From this assumption, the best fitting indices of predominance were examined. The simplest model of the visual system was one in which the periodicity of the two originates was expressed by a differential equation. Various indices were examined by the solution of its equation so that a power function of the ratio of the time of appearance to that of disappearance was obtained as the most suitable index of the predominance.

Discrimination Learning↗

PubMed1986

Periodicity of strength of pattern in binocular rivalry.

The effect of suppression in binocular rivalry is divided into the effects of boundary and of region. By removing the effect of boundary from the double effects, we examined whether the strength of pattern oscillates throughout duration of suppression phase. Probabilities of appearance of the suppressed test patterns were measured immediately after the removal of the suppressing pattern at various temporal points after onset of suppression. The probabilities decrease, reach a minimum level, and then increase throughout the course of the suppression phase. Immediately after the beginning of the suppression phase, the small test pattern whose duration of suppression is short rarely appears, while the large pattern whose duration of suppression is long certainly appears. These results support our hypothesis for which the key assumption is that the strength of pattern periodically oscillates as a function of duration of observation time.

Adult↗

PubMed1985

Analysis of temporal suppression mechanism in binocular rivalry.

A method for analyzing the temporal suppression mechanism in binocular rivalry is described. A test pattern was presented to one eye and a suppressing pattern to the other eye after varying time intervals. The subject was instructed to report the frequency of nonsuppression phases of the test pattern immediately after presentation of the suppressing pattern. Analysis indicated that the test pattern was never suppressed at the 0-msec. stimulus onset asynchrony and the nonsuppression probabilities decreased as the onset asynchrony increased. Moreover, resistivity to contralateral suppression was greater when the test pattern was projected to the dominant eye.

Adult↗

PubMed1985

Method for measuring strength of suppression in binocular rivalry.

A method for measuring the strength of suppression of a suppressing pattern is examined. The test pattern was a black filled circle 1 degree in diameter and suppressing patterns were black outline circles 1, 1.2, 1.5, 2, 3, and 4 degrees in inner diameter, respectively. Each subject (2 men, 2 women) was asked to report the frequency of suppression phases of the test pattern immediately after presentation of the suppressing pattern. Analysis indicated that the method used is effective as a way of analyzing the rivalry process and the effect of eyedness.

Adult↗

PubMed1984

Enhanced neutrophilic functions in mucocutaneous lymph node syndrome, with special reference to the possible role of increased oxygen intermediate generation in the pathogenesis of coronary thromboarteritis.

To examine the possible correlation between mucocutaneous lymph node syndrome and thromboarteritis, we studied the capacity of polymorphonuclear leukocytes from 30 pediatric patients with mucocutaneous lymph node syndrome to generate oxygen intermediates and to release lysosomal enzymes. Cultured endothelial cells from human umbilical cord vein were also incubated with PMNs to assess oxygen intermediate-induced tissue injury. Within five days of MLNS onset, oxygen intermediate production, except for chemiluminescence generation, was markedly increased and the 51Cr release from labeled endothelial cells was significantly elevated. The lysosomal enzyme release was slightly, but significantly, higher. In the presence of superoxide dismutase and catalase, the 51Cr release was reduced to the control level, indicating the specificity of the effect of oxygen intermediate endothelial cell damage. At more than six to seven days after MLNS onset, the PMN functions were normal or decreased and the 51Cr release was reduced. In view of reports that coronary occlusion may appear one week after MLNS onset, we suggest that in the early stage of MLNS, a marked increase in oxygen intermediate generation induced by activated PMNs gives rise to coronary vascular injury, possibly leading to thromboarteritis and aneurysm formation.

Arteritis↗