Tokuo Tsubokura

Intralymphocytic sodium and free calcium and plasma renin in essential hypertension.

Intraceilular sodium, potassium, and free calcium concentrations were investigated in lymphocytes of 30 patients with essential hypertension and 30 normotensive controls. All subjects were placed on a diet containing 8 to 10 g of sodium chloride per day. Lymphocyte sodium concentration was higher in hypertensive patients than in normotensive controls (19.8 ± 1.8 vs 18.4 ± 1.8 mmol/kg wet weight; p < 0.01), whereas lymphocyte potassium concentration was similar in both groups. Lymphocyte free calcium concentration was also higher in hypertensive patients than in normotensive controls (134.6 ± 13.2 vs 120.2 ± 16.4 nmol/L; p < 0.01). There was a positive correlation between lymphocyte sodium and free calcium concentrations in normotensive controls, in hypertensive patients, and in the subjects combined (r = 0.59, p < 0.01; r = 0.71, p < 0.001; and r = 0.70, p < 0.001, respectively). Lymphocyte potassium concentration was not related to lymphocyte sodium or free calcium concentration in each group. In patients with essential hypertension, intraceilular sodium and free calcium concentrations were negatively correlated with plasma renin activity (r = −0.66, p < 0.001; r = −0.60, p < 0.001, respectively), but they were not related to age, mean blood pressure, serum electrolyte concentration, or plasma norepinephrine concentration. These results suggest that a considerable relationship exists between intraceilular sodium and free calcium in lymphocytes and that, in essential hypertension, the alteration in cellular metabolism of sodium and calcium may be linked to the renin system but not to blood pressure, age, or adrenergic activity.

Fuzzy realization in clinical test database system.

To be able to obtain useful information from medical data easily and quickly in daily use for the hospital staff, it is necessary to construct a proper database system using methodologies suitable for the nature of medical data. From this viewpoint we have developed the clinical test relational database system at Hiroshima University Hospital, which provides the functions of easy on-line retrieval and statistical analysis. Fuzzy query processing based on the fuzzy set theory is adopted in the system. This enables us to use natural linguistic representation and makes it easy to introduce medical knowledge representation. Fuzzy set approaches turn out to be superior in clinical evaluation of laboratory data to the ordinary clear-cut definition of normalcy.

Assessment of supra-valvular abnormal signal with color Doppler flow mapping in patients with aortic regurgitation

A supra-aortic abnormal flow signal (proximal acceleration) was studied in 62 patients with aortic regurgitation with the use of color Doppler flow mapping. The proximal acceleration signal was detected in 28 of the 62 patients and was shaped like a V or a teardrop. In the 29 patients who underwent aortography, a proximal acceleration signal was observed in all 18 patients with severe and moderate regurgitation and in only one of the 11 patients with mild regurgitation. The sensitivity for the diagnosis of severe regurgitation from the existence of a proximal acceleration signal was 100%, specificity 50%, and predictive accuracy 47%. A close correlation between the area of the proximal acceleration signal and the width of the aortic regurgitant jet signal was observed (r = 0.81). An acceleration area of 45 mm2 or more was observed in eight of the nine patients with severe regurgitation, in four of the nine patients with moderate regurgitation, and in none of the patients with mild regurgitation. Sensitivity for the diagnosis of severe regurgitation from an area of proximal acceleration of more than 45 mm2 was 89%, specificity 80%, and accuracy 67%. These results suggest that evaluation of the area of the supra-aortic abnormal signal may be a useful auxiliary aid in estimating the severity of aortic regurgitation.

Flow Velocity Measurement and Differentiation Between True and False Lumens in Patients with Abdominal Aortic Dissection by Use of Pulsed Doppler Echocardiography

Feasibility of differential diagnosis between the true and false lumens was studied with pulsed Doppler echocardiography in 8 patients with abdominal aortic dissection. The blood flow signal was obtained in both lumens in 7 of the 8 patients and in only the true lumen in the remaining 1 patient. The blood flow pattern was abruptly changed when the sample volume was moved from the true lumen to the false one. The peak flow velocity was higher in the true lumen (95 ± 19 cm/sec) than in the false one (28± 12 cm/sec) and ejection flow duration was longer in the former (306 ±103 ms) than in the latter (163 ±53 ms). The appearance time of ejection flow was not different between them. The presence of reverse flow during the ejection phase was more frequent in the false lumen (5/7) than in the true one (2/8). Thus, the conventional pulsed Doppler study may provide useful information in making a differential diagnosis between the true and false lumens in patients with abdominal aortic dissection.

Comparative study on the influences of plasma substitutes on the blood coagulation

Comparative study on the influence of plasma substitutes, dextran, hydroxyethyl starch and gelatin derivative solution, on the blood coagulation was carried out in dogs with thrombelastogram.It was demonstrated that plasma substitutes caused a remarkable suppression of the coagulation system inducing qualititative and quantitative changes of the coagulation factors. However, these changes did not seem to be related to hemodynamic disorders. Much greater decrease of platelets and fibrinogen levels than that of hematocrit following hemodilution with plasma substitutes suggests that the suppression of the coagulation system observed after infusion of plasma substitutes is likely to be due to consumption.