Adequacy and nutrition in the absence of residual renal function in peritoneal dialysis.

With the aim of evaluating nutrition indices and dialysis adequacy level in patients who started peritoneal dialysis (PD) without residual renal function, we retrospectively studied 19 patients [8 men, 11 women; 3 with diabetes (15.8%); mean age: 44.5 +/- 10.74 years; 15 on continuous ambulatory peritoneal dialysis (CAPD), 3 on continuous cycling peritoneal dialysis (CCPD), 1 on nightly intermittent peritoneal dialysis (NIPD)]. The mean time spent by these patients on hemodialysis before PD was 62.7 +/- 54.7 months (range: 8.8-216 months), and the mean time on PD was 46.2 +/- 21.4 months (range: 10-75 months). In these patients, we measured weekly Kt/V urea, weekly creatinine clearance (CrC), normalized protein catabolic rate (nPCR), body surface area (BSA), urea distribution volume (V), serum albumin, body mass index (BMI), percent lean body mass (%LBM), infusion volume (liters per day), subjective global assessment (SGA), and peritoneal equilibration test (PET). Using the Student t-test at a significance level of p < 0.05, we compared initial body weight (INW), actual weight (AW), and ideal body weight (IBW) according to age, sex, and height. We analyzed actuarial and technique survival (Kaplan-Meier). In regard to patient survival, only death was considered the end point; for technique survival, only technique failure was considered the end point. Data are expressed as mean +/- standard deviation. Results were: Kt/V, 2.20 +/- 0.46 L weekly; CrC, 59.11 +/- 12 L weekly; nPCR, 1.08 +/- 0.25 g/kg daily; BSA, 1.67 +/- 0.2 m2; V, 33.34 +/- 7.12; serum albumin, 3.68 +/- 0.22 g/dL; BMI, 24.06 +/- 4.16; %LBM, 64.92 +/- 10.13; SGA, 94.7% well-nourished; AW, 65.37 +/- 13.88 kg; IBW, 67.21 +/- 10.5 kg (AW vs IBW: r = 0.69, p > 0.05); INW, 61.54 +/- 11.07 kg (INW vs AW: r = 0.92, p < 0.05; INW vs IBW: r = 0.71, p < 0.05). Distribution of transport status by PET was 15.8% high transport, 36.8% high-average transport, 36.8% low-average transport, and 10.5% low transport. Mean infusion volume was 10.41 +/- 1.36 L in 24 hours. Cumulative survival was 100%, 98%, and 82% after 1, 2, and 6 years respectively. Technique survival was 100% after 6 years. The adequacy results accord with Dialysis Outcomes Quality Initiative (DOQI) recommendations, and the nutrition indices and actuarial and technique survival are satisfactory for anuric patients.

Transport equations for a microbial predator-prey community.

A transport equation is used which describes the temporal behavior of interacting populations in changing environments. The formulation takes into account the internal state variables of the individuals. The general theory is applied to the transient analysis of a microbial predator-prey system using an approximate model for the specific cell growth rate and multigroup formulism to approximate the mass distribution within the population. Experimental results in aTetrahymena pyriformis- Aerobacter aerogenes system have been used to evaluate the group parameters and test the validity of the theoretical predictions.