Head-out water immersion (HOI) induces various renal functional changes, such as diuresis, natriuresis, and kaliuresis. The present study was undertaken 1) to characterize the renal response to HOI in Koreans who routinely ingest high salt diet and 2) to evaluate the impact of exercise on the renal response to HOI. Six healthy male subjects (average Na+ intake of 232 mEq.day-1) were immersed upto the neck in 34.5 degrees C water and rested in a seated position or exercised on a bicycle ergometer for 3 hours. In resting subjects, we observed a reversible increase in urine flow and a decrease in urine osmolality, with no changes in creatinine clearance. The peak urine flow observed during the second hour of immersion was 4-fold greater than the pre-immersion level. The excretion of total osmotic substances rose progressively during the 3-hour immersion, which was accompanied by a similar change in Na+ excretion. The K+ excretion was slightly elevated. The major component of the immersion diuresis was a water diuresis in the early phase and an osmotic diuresis in the late phase of immersion. In exercising subjects, the diuretic and natriuretic responses to HOI were attenuated and the kaliuretic response was potentiated. Blood hemoglobin concentration and plasma levels of renin, ADH, and aldosterone decreased during immersion-rest, but they remained unchanged or increased during immersion-exercise. These results suggest that 1) the cardiac mechanoreceptor-mediated renal responses to HOI are not changed by chronic high salt diet, and 2) excessive urinary sodium and water losses are prevented by exercise during immersion.

The karyotype of goral (Nemorhaedus caudatus, 2n = 56) was prepared using lymphocytes and its chromosomal band patterns were compared with those of goat (Capra hircus, 2n = 60) by CBG-, GTG- and RBG-banding techniques. The standard karyotype of goral was composed of 54 acrocentric autosomes, submetacentric X chromosome, and acrocentric Y chromosome. C-bands were prominent in all autosomes except the X chromosome. G- and R-band patterns of goral were dissimilar to those of goat. The data support the idea that the goral did not originate from a common ancestor of bovid, or that there were numerous complicated chromosomal interchanges during goral evolution, in contrast to other bovids.

The repetition of forward and backward filtration during hemodialysis (HD) increases convective mass transfer, and thus, the authors devised a method of achieving cyclic repletion of ultrafiltration and backfiltration. Hemodialytic efficiencies of the developed unit are described. The devised method, named pulse push/pull hemodialysis (PPPHD), is based on the utilization of dual pulsation in a dialysate stream. Clearances of solutes with different molecular weights were determined, and in vivo hemodialytic performance was investigated in a canine renal failure model. Urea and creatinine reduction and albumin (ALB) loss were monitored, and the results obtained were compared with those of a conventional high-flux hemodialysis (CHD). Dialysis sessions were repeated eight times for PPPHD and six times for CHD by alternating PPPHD and CHD sessions in a single animal, which remained stable throughout the experiments. Urea and creatinine reductions for the PPPHD unit were 49.2 ± 2% and 44.3 ± 3.3%, respectively, which were slightly higher than those obtained for the CHD. Total protein and ALB levels were preserved by both methods. However, in vitro results revealed that PPPHD achieved significantly greater inulin clearance than CHD. The developed PPPHD unit facilitates repetitive filtration and improves convective mass transfer during HD, without the need for external replacement infusion.

Although hemodiafiltration is presumed to be a gold standard for higher convective therapy for kidney failure patients, the repetition of forward and backward filtration during hemodialysis increases the total filtration volume and convective clearance. Hence, the authors describe a new method of enhancing forward filtration and backfiltration. The devised method, named pulse push/pull hemodialysis (PPPHD), is based on the utilization of dual pulsation in a dialysate stream; namely, pulsatile devices in the dialysate stream both upstream (a dialysate pump) and downstream (an effluent pump) of the dialyzer. Fluid management accuracy of the unit was assessed using fresh bovine blood, and its hemodialytic performance was investigated in a canine renal failure model. Forward filtration rates during PPPHD were maintained at the levels of dialysate flow rates. Fluid balancing error was less than ±0.84% of total dialysate volume, when 97.4 ± 1.66L of pure dialysate was circulated for 4 hs. The animal remained stable without any complication. Urea and creatinine reductions were 56.9 ± 1.6 and 52.8 ± 2.3%, respectively, and albumin levels remained uniform throughout treatment. The devised PPPHD unit offers a simple, but efficient strategy of combined simultaneous diffusive and convective solute transport for ESRD patients, without the need for external replacement infusion.

No abstract