The "standard urea clearance" is calculated upon the assumption that the urea excretion will vary with the square root of the urine volume, when the latter is below the augmentation limit of about two milliliters per minute. The result of the calculation gives the milliliters of blood which would be cleared were the urine volume one milliliter per minute, if the square root rule were strictly t...

The aims of this study were 1) to determine whether transfer of blood urea to the gastrointestinal tract (GIT) or the efficiency of capture of urea N within the GIT is more limiting for urea N salvage, and 2) to establish the relationship between plasma urea concentration and recycling of urea N to the GIT. We used an i.v. urea infusion model in sheep to elevate the urea entry rate and plasma c...

BACKGROUND The efforts to improve the quality of haemodialysis (HD) has renewed the interest in the consequences of blood-flow distribution for removal of solutes. METHODS To test the effects of HD time per se, 10 patients were studied in a cross-over fashion with HD for 3 h and 1 week later for 6 h, with similar blood urea Kt/Vs, achieved by adjusting the blood flow rate to 290 and 120 ml/mi...

1. The significance of blood urea-nitrogen transfer to the rumen was examined in sheep given alkali-treated wheat straw supplemented with 3.5 (diet A), 5.9 (diet B) and 11.6 (diet C) g urea-N/kg dry matter (DM). 2. Mean voluntary intakes of DM (g/d) were 897, 1149 and 1225 for diets A, B and C respectively, indicating significant (P less than 0.05) intake responses to urea supplementation. Dige...

In a recent number of this Journal,’ a new method for the estimat,ion of urea in urine was described. This method consists in the conversion of the urea into ammonium carbonate by means of the urease of the soy bean, and an estimation of the alkalinity before and after the conversion by means of standard acid and methyl orange. The procedure is not directly applicable to the est,imation of urea...

BACKGROUND Patients with chronic kidney disease (CKD) need regular monitoring, usually by blood urea and creatinine measurements, needing venepuncture, frequent attendances and a healthcare professional, with significant inconvenience. Noninvasive monitoring will potentially simplify and improve monitoring. We tested the potential of transdermal reverse iontophoresis of urea in patients with CK...

High blood urea nitrogen (BUN) concentration is linked to low fertility in cows and ewes; however, this relationship has not been reported mares. The study characterized the between BUN follicular fluid (FUN) during follicle growth (Experiment 1) impact of from embryo donors on pregnancy outcome recipient mares 2). In experiment one, samples were collected diestrus with growing follicles estrus...

Two types of multilayer-film slides for measurement of urea nitrogen in blood are reported here: one for whole-blood samples, the other for plasma or serum. Urea nitrogen concentrations in plasma are determined almost immediately, without preparation of reagents or centrifugation of blood samples. Because the sample volume applied to the slide is not critical, reliable results are quickly obtai...

Investigating the Effect of Replacing Soybean Meal with Poultry Slaughterhouse Waste Mixed Rice Bran and Urea on Performance, Blood Rumen Parameters Fattening Lambs

The aim of the study was to explore the possibility of utilizing UV-absorbance measurements of spent dialysate to assess urea rebound. Ten patients on chronic three-times-a-week hemodialysis were included in the study. On-line UV-absorbance of spent dialysate was monitored. Urea rebound was calculated based on urea concentration in blood (Rb) and UV-absorbance in spent dialysate (Ra). Rb and Ra...