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A B S T R A C T Clearance studies were performed on 49 split-bladder dogs with a unilateral pyelonephritic or remnant kidney and three patients with unilateral kidney disease to examine the effects of an acute saline load on the diseased kidney (DK) as opposed to a simultaneously studied, contralateral control kidney (CK), which also served to maintain a nonuremic environment.Before saline loading, base line studies in many of the dogs and the three humans were in agreement with previously published data. However, in dogs with a severe pyelonephritic lesion, a greater difference in DK vs. CK fractional excretion of sodium (FEN.) and water was noted, whose magnitude was inversely correlated with the level of glomerular filtration rate (GFR) and maximum urine osmolality of DK compared to CK.An acute saline load (75 ml/kg) resulted in an inhibition of fractional sodium and water reabsorption in the diseased dog kidney which was disproportionately greater than in the simultaneously studied CK, regardless of the type or severity of the lesion. While mean DK GFR for all dogs increased 15% more than CK GFR, failure of FENa to increase after induction of a disproportionate increase in DK GFR with parathyroid hormone suggested that the saline-induced disproportionate increase in GFR was not solely responsible for the exaggerated inhibition of fractional sodium and water reabsorption in the diseased dog kidney. Studies in the three patients after saline loading (25 ml/kg)

Various means of characterizing ultrasonic attenuation in tissue are reviewed. A simple method for estimating frequency-dependent attenuation via measurement of the zero crossing density of the signal is presented and validated. Both the effects of the frequency dependence of scatter and stochastic variability of the measurement are considered and discussed. Results of measurements made in phantoms, animals and humans are presented and compared to the theoretical model. The technique is shown to be technically feasible.

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An Army trainee developed acute water intoxication, hyponatremia, pulmonary edema, and fatal cerebral edema. This is the first report of a fatality related to urine drug testing. This resulted from supervised excessive water ingestion in an attempt to induce a sufficient urine specimen for substance abuse testing. To avoid a similar preventable death in the future, we make several recommendations. These include limiting the volume of ingested fluid to eight ounces every 30 to 45 minutes, not to exceed 40 ounces, and providing a relaxed, reassuring environment when obtaining urine specimens for substance abuse detection.