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Biomedical subjects

H Asaba

Publications and source records attributed to H Asaba.

At least 19 recordsLinked to original sources
PubMed1991

P300 in first degree relatives of schizophrenics.

It has been reported that the amplitude of P300 is low in schizophrenic patients and high risk children. We recorded P300 components of the event-related potentials in first degree relatives of schizophrenic propositi who were considered to be over the age limit of the risk period for manifestation of schizophrenia and compared them with those of schizophrenic patients and controls. Both the first degree relatives and the schizophrenic patients showed lower P300 amplitude than the controls. There was no significant difference between the first degree relatives and schizophrenic patients in the P300 amplitude. These results would indicate that a low P300 amplitude is a trait marker for schizophrenia.

Adult↗
PubMed1990

Failure to manipulate objects secondary to active touch disturbance.

A peculiar type of sensori-motor disturbance consequent to a lesion in the contralateral postcentral gyrus was reported. The symptom was characterized by motor clumsiness of the left hand without loss of strength and with preserved finger movements on visual imitation. Motor difficulty was most marked when the patient had to manipulate an object. The analysis of the patient's behavior and of his sensory deficits suggests that the basis of the clumsiness was a deficit in active touch perception.

Cerebral Infarction↗
PubMed1990

Event-related potential (P300) in epilepsy.

The P300 component of auditory event-related potential was studied in 39 patients with temporal lobe epilepsy (TLE), 26 with idiopathic generalized epilepsy (IGE) and 28 controls. The age-corrected P300 latencies were significantly longer in TLE patients compared with those in IGE patients and controls. Neither the duration of epilepsy nor clinical manifestation was related to the P300 component in the same epileptic syndrome. The age-corrected P300 latencies recorded from Cz were significantly prolonged in TLE patients with bilateral temporal EEG foci compared with those with unilateral focus. The effects of anti-epileptic drugs on the P300 component were not significant. Our findings imply that prolonged P300 latency in TLE patients, especially in those with bilateral EEG foci is due to damage of the hippocampus, which is potentially an epileptogenic focus.

Acoustic Stimulation↗
PubMed1989

Event-related potentials (P300) in myotonic dystrophy.

The P300 component of the auditory event-related potential in 8 patients with myotonic dystrophy was studied and compared with that of 13 healthy controls. Abnormalities of P300 (prolongation of the latency and/or decrease of the amplitude) were observed in 6. These observations imply that the function of cognitive and information processing are impaired in myotonic dystrophy.

Acoustic Stimulation↗
PubMed1989

Motor learning in ideomotor apraxia.

Using Luria's motor sequence test, we studied the learning ability of 34 right-handed patients with unilateral hemisphere lesions. Patients with ideomotor apraxia needed 4 to 6 trials in the test, while the remainder needed only 1 or 2. Ideomotor apraxics also required more time to complete the test. The lesions of patients who failed to master this test were not always found in the frontal lobes. These results suggest that the ability to learn motor sequences is impaired in apraxic patients and that the left hemisphere of the brain plays the major role in learning a new motor sequence. Patients with ideomotor apraxia are impaired not only when performing previously learned motor tasks but also when learning a new motor task.

Aged↗
PubMed1979

Hemodynamic changes during sequential ultrafiltration and dialysis.

Seven patients on regular dialysis were studied to elucidate the hemodynamic changes during ultrafiltration and dialysis, performed sequentially, the period of ultrafiltration (1 hour) either preceding or following dialysis (3 hours). During dialysis ultrafiltration was prevented by applying positive pressure in the dialysate compartment. Cardiac index (dye dilution: indocyanine green), heart rate, stroke volume index, blood pressure, and total peripheral vascular resistance index were measured. During ultrafiltration, cardiac index and stroke volume index decreased, but heart rate was not significantly changed. Total peripheral vascular resistance increased, resulting in unchanged blood pressure. During dialysis, the total peripheral vascular resistance decreased, but cardiac index and heart rate increased. BP decreased when the increase in cardiac index was insufficient to compensate for the decrease in total peripheral vascular resistance. PRA increased during ultrafiltration due to hypovolemia and decreased during dialysis, presumably due to decreased sympathetic activity which may also be a cause of dialysis-induced vasodilation.

Adult↗
PubMed1979

Removal of endogenous middle molecules by hemoperfusion.

In four regular dialysis patients, the removal of uremic middle molecules was studied during a three-hour hemoperfusion using a column containing 300 gm of activated carbon encapsulated with cellulose. Middle molecules in plasma were determined by high-speed gel filtration followed by gradient elution chromatography. Different adsorption characteristics were shown for the four middle molecule fractions measured. The initial clearances for middle molecule fractions were about 120 ml/min; clearances were 20-50 ml/min after two hours, and less than 25 ml/min, with release of some middle molecule fractions from the column, after three hours. The findings suggest that saturation of the column occurs after two to three hours of perfusion. Thus, prolongation of the perfusion time beyond two hours appears to be of little benefit. The reduction of middle molecules in plasma by a three-hour hemoperfusion was in magnitude, similar to that obtained by three-hour dialysis with a large surface area dialyzer or high-flux membrane.

Capsules↗
PubMed1979

[Hemodynamic changes during ultrafiltration and hemodialysis in uremia].

1. The ultrafiltration causes a reduction of blood pressure and minute output of the heart which is compensated by vasoconstriction and thus a decrease of blood pressure is prevented. 2. Changes in the salt concentrations with reduction of the osmolarity during the dialysis without simultaneous ultrafiltration lead to vasodilation and hypotension despite increase of the minute output of the heart. 3. During a usual haemodialysis (i.e. dialysis with simultaneous ultrafiltration) the vasodilating effect of the dialysis may abolish the vasoconstrictive effect of the ultrafiltration and thus may be the cause of the hypotension.

Adult↗
PubMed1979

The effect of hemodialysis on endogenous middle molecules in uremic patients.

Uremic plasma and dialysis fluid were separated by high speed gel filtration followed by gradient elution ion exchange chromatography into several UV-absorbing fractions containing middle molecules (MM) (7a, b, c, etc.), which were quantitated by integrating the peak areas of the chromatograms. Dialyzer clearance of MM was determined in vivo for two dialyzers, Gambro Optima and RP-6, but no difference could be found in spite of far better in vitro MM clearance of RP-6 than of Gambro Optima. Nor was there any difference in post-dialysis decrease in MM between the two dialyzers, or between them and two dialyzers with larger surface areas (Gambro Major and Dow HK-5). In 45 determinations of MM in blood obtained before and after dialysis, using different dialyzers, the mean decrease in MM was significantly larger than for creatinine, suggesting a much smaller distribution volume immediately available for exchange. Ultrafiltration without dialysis in 7 patients induced a significant decrease in plasma MM (7a, b, c, and g) in spite of stable osmolality, urea, creatinine, and sodium concentrations in plasma, suggesting that the reduction in body water affected the net production rate of these MM. In 5 studies, using RP-6 and a 75 l recirculating dialyzate, a rapid post-dialysis rebound was observed for MM in plasma, sometimes followed by a secondary decrease in plasma concentration. The volume of distribution of dialyzed MM, assessed from pre- and post-plasma concentrations and concentrations in the dialyzate, appeared to be much smaller than for urea and creatinine. In a stable dialysis population of 17 patients, significant negative correlations were found between pre-dialysis plasma concentrations of some MM (7a, 7b, 7f, 7g) and dialysis index or endogenous renal creatinine clearance. No such correlations were found for peaks 7c and 7d. The good correlation between 7b and dialysis index (r = 0.73) suggests that plasma determination of 7b may be used as a measure of the efficiency of MM removal.

Chromatography, Gel↗
PubMed1979

Fibrin deposition in disposable dialyzers before and after re-use.

We have estimated the degree of fibrin deposition as well as changes in dialyzer efficiency of Gambro Optima 13.5 mu dialyzers, re-used up to six times in six regular dialysis patients. After each dialysis the dialyzer was rinsed and left filled with formaldehyde. The patients were given I-125-fibrinogen before the study. The radioactivity from the dialyzer was continuously measured during each dialysis and rinsing procedure. Urea and creatinine clearances were determined 30 min after start of each dialysis. After the last re-use the dialyzer membranes were removed and divided into sections and the radioactivity of each section was measured. Twice as much fibrin deposition was found near the blood inlet of the dialyzer as near the outlet. A higher fibrin deposition was found after each re-use than after the initial dialysis. The clearances of urea and creatinine were scarcely influenced by the re-use. The half-life of fibrinogen in the patients was in the same range as in normal subjects.

Adult↗
PubMed1978

Treatment of diuretic-resistant fluid retention with ultrafiltration.

Nine patients with diuretic-resistant edema, secondary to congestive heart failure, liver cirrhosis, or nephrotic syndrome, were treated with ultrafiltration using high water flux dialyzers. Access to the blood stream was obtained by femoral vein catheterization. As much as 8.3 kg of fluid were removed in 3--4 hours with only transient decline in blood pressure. The procedure was well tolerated and yielded immediate symptomatic relief. The potential for restoration of an edema-free state in patients with diuretic-resistant edema suggests that further experience with this technique is justified.

Diuretics↗
PubMed1978

The influence of dialysis fluid composition on the blood pressure response during dialysis.

To elucidate the relative role of osmolar (sodium) and acetate shifts during dialysis, 6 patients with problems of overhydration underwent rapid ultrafiltration for 1 hr (mean weight reduction 2.0 kg), using the 1 m2 RP 6 dialyzer. Ultrafiltration was carried out at the beginning of each of 5 dialysis treatments at weekly intervals. Ultrafiltration was undertaken without dialysis (controls) and with simultaneous dialysis using acetate (40 mmoles/1) or bicarbonate (25 mmoles/1) in the dialysis fluid with dialyzate sodium concentration of 133 and 145 mmoles/1. The systolic blood pressure and mean arterial pressure which were stable with ultrafiltration only fell slightly when a high dialyzate sodium concentration was used and much further when the dialyzate sodium concentration was kept low. These changes were apparently related to the changes in plasma osmolality. Acetate had no effect on blood pressure at the higher sodium concentration, but a slight (insignificant) additive effect when used in the low-sodium dialyzate. Shifts in osmolality (sodium concentration) seem to be more important than the effect of acetate in inducing dialysis-associated hypotension.

Acetates↗