Hydration status measurement by radio frequency absorptiometry in young athletes--a new method and preliminary results.

A new method for non-invasive measurement of the human state of hydration is presented. This method is based on frequency-dependent absorptiometry of radio-waves passing through tissues. A device utilizing this method was constructed and applied to 12 young (24 +/- 1) male volunteers, who were dehydrated for 1-2.

Sensitivity of the high-power field method in detecting red blood cells in the urinary sediment.

The red blood cell (RBC) content of urine specimens was determined both by direct counts by a hemocytometer and by the number of RBCs per high-power field (HPF) in the sediment by routine urine analysis. The sensitivity of a finding of 1 to 3 and 2 to 4 RBCs/HPF in detecting greater than or equal to 2,000 RBCs/ml unspun urine was 63% (73/116) and 54% (63/116), respectively. There was a wide range of values of RBCs/ml determined by direct counts for each degree of microscopic hematuria as defined by the HPF method.

Value of three annual blood pressure determinations in young adults as a predictor of elevated systolic blood pressure 15 years later.

The records of 726 male air force personnel aged 18 to 34 years in 1968 were searched for the results of examination of the systolic blood pressure (SBP) in 1968 and during the following 15 years ending in 1983. An elevated recent blood pressure (BP), defined as an SBP greater than or equal to 140 mm Hg on two or more of the last three follow-up examinations, done 13, 14, and 15 years after entry, was found in 3.2% of the cohort.

Predictive value of the resting electrocardiogram for Mobitz type I atrio-ventricular block on Holter monitoring in Israeli air force personnel.

During 1981-1984, a total of 52 airpersonnel had 24-h continuous ambulatory electrocardiographic (ECG) monitoring at the Israel Air Force Aeromedical Center because of an incidental finding of a first or second degree atrio-ventricular block on a resting 12-lead ECG. There were 230 other airpersonnel without AV block on the resting ECG monitored during the same period. Altogether 17 cases of second degree Mobitz type I (Wenckebach) block were identified.

Factors associated with microhematuria in asymptomatic young men.

The prevalence of asymptomatic microhematuria (two to four or more erythrocytes per high-power field) in 1341 male Air Force personnel was 5.4%. The most powerful predictor of microhematuria (nearly 15-fold increased prevalence) was a history of recurrent microhematuria during the previous five years.