[The absence of monocyte-granulocyte antigen expression in a case of AML].

The brief record of a 25 y. o. male patient with AML (FAB M1) is shown, in whom the blast cells did not express any of the 5 myeloid antigens or the other-lineage related antigens, as detected with the monoclonal antibodies. The blast cells were induced to express CD13 antigen after a short-term culture in vitro. This result suggests that CD13 antigen can be expressed virtually by all AML cells, since CD13 antigen is known to cover fresh AML cells at the highest incidence. No unusual clinical feature was noted in this patient as AML case. The collected documentation of antigen-free AML cases seems necessary for the relevant understanding of AML heterogeneity.

Acute effects of exposure to cold on blood pressure, platelet function and sympathetic nervous activity in humans.

To clarify the mechanism for cold-related thrombosis, we evaluated responses of blood pressure, platelet function, and sympathetic nervous activity after cold exposure in ten healthy male volunteers (33 +/- 2 years old). Mean blood pressure, beta-thromboglobulin, platelet factor 4, and plasma noradrenaline were increased after cold exposure associated with significant falls in skin, oral, and urine temperature. The increase in plasma noradrenaline significantly correlated with the change in platelet aggregation (3 microM ADP: r = 0.73, P less than .02, 3.0 micrograms/mL epinephrine: r = 0.65, P less than .05), and with mean blood pressure in the warn environment (r = 0.76, P less than .02). These results suggest that the cold-related increase in sympathetic nervous activity may contribute to enhancement of platelet function. This provides a possible explanation for the risk of thrombosis in cold weather in essential hypertension.

Left ventricular filling characteristics in sodium-depleted and sodium-loaded patients with mild essential hypertension.

To determine left ventricular early diastolic function and transmitral blood-flow characteristics during periods of sodium depletion (50 mmol/day) and sodium loading (300 mmol/day), Doppler and standard echocardiography were performed in 13 patients with untreated mild hypertension. A high sodium intake for 7 days significantly increased (P less than 0.05) the ratio of Doppler atrial contraction phase peak velocity A to rapid filling phase peak velocity R. The isovolumic relaxation time was prolonged (P less than 0.001) and the left atrial emptying index was reduced (P less than 0.05). During sodium loading the changes in isovolumic relaxation time and the atrial emptying index were correlated with the increase in mean wall stress (r = 0.600, P less than 0.05 and r = -0.695, P less than 0.01, respectively), but not with the increase in end-diastolic volume. These results suggest that during excess salt intake, left ventricular relaxation and filling may be impaired due to a salt-induced increase in afterload in patients with mild hypertension.

Effects of oral magnesium on blood pressure and red cell sodium transport in patients receiving long-term thiazide diuretics for hypertension.

Twenty patients receiving long-term (1.0 to 10.3 years) thiazide diuretic treatment for essential hypertension (Th group) received magnesium supplementation as MgO (600 mg Mg/day) for 4 weeks and placebo for another 4 weeks. Before and at the end of each period, we measured blood pressure; intraerythrocyte magnesium, sodium, and potassium (R-Mg, R-Na, and R-K); and erythrocyte ouabain (10-4 M) sensitive sodium efflux rate constant (Kos). The same measurements were also performed in 21 untreated age-matched essential hypertensives (EHT group). In the Th group, R-Mg was lower, R-Na was higher, and Kos was lower than in the EHT group before magnesium supplementation. Oral magnesium resulted in a significant increase in R-Mg (p less than 0.005) and a decrease in R-Na (p less than 0.01), together with an increase in Kos (p less than 0.005) in the Th group. During magnesium supplementation, the increased Kos was correlated negatively with the lowered R-Na (r = -0.57, p less than 0.01) and positively with the increased R-Mg (r = 0.61, p less than 0.005). Systolic, diastolic, and mean blood pressures were reduced significantly during magnesium administration by a mean of 7.5, 3.0, and 4.5 mm Hg. The results indicate that long-term diuretic treatment may give rise to an intracellular magnesium deficiency and a suppression in cell membrane active transport for sodium, with a resultant increase in intracellular sodium content.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationships between red cell cation contents and blood pressure level.

Red cell sodium (R-Na), potassium (R-K) and sodium to potassium ratio (R-Na/K) were studied in 2,542 adults participating in periodic medical examinations. The mean values of R-Na and R-Na/K in untreated borderline (n = 406) and definite hypertensives (n = 485) were higher than those in normotensives (n = 1,651), but that of R-K was not different among the groups. The increased R-Na and R-Na/K in the hypertensives were observed only in those under 50 years, but not in those 50 years and over. In the normotensive subjects, age and sex affected the intraerythrocyte cation contents, but a positive family history of hypertension did not. Although a few characteristics correlated with both R-Na and mean blood pressure, and with both R-Na/K and mean blood pressure, multiple regression analyses revealed that R-Na and R-Na/K independently and significantly contributed to the variation in mean blood pressure. It was also indicated that these relations of R-Na and R-Na/K to mean blood pressure were significant in those under 50 years, but not in those 50 years and over. While several characteristics confound the relationships between red cell cation contents and blood pressure, these results suggest that the contributions of R-Na and R-Na/K to the mechanisms of human hypertension still persist in young to middle-aged people.