Evidence is presented that the enzymes catalyzing the three reactions involved in urea cleavage in Candida utilis, biotin carboxylation, urea carboxylation, and allophanate hydrolysis occur as a complex of enzymes. The allophanate-hydrolyzing activity could not be separated from the urea-cleaving activity using common methods of protein purification. Further, urea cleavage and allophanate hydro...

Because urea is bioenergetically expensive to synthesize, few aquatic teleostean (bony) fish make or excrete much urea beyond early development and excrete the majority of nitrogenous waste as the readily diffusible ammonia. The gulf toadfish is one of a few adult teleostean fish that excretes predominantly urea. Most studies of chemosensing by fish predators have focused on amino acids as odor...

The concentrations of urea, urate, phosphate and creatinine were measured in the plasma of 30 consecutive patients admitted acutely with heart failure. On admission, 20 had a raised plasma urea, 21 had a raised plasma urate, but only 6 had a raised plasma phosphate and only 6 had a raised plasma creatinine. A further 9 of the patients developed a raised plasma urea after admission. The increase...

chlorosis, but the addition of urea to the solu tion appeared to enhance the effect of the biuret. Experiment 4. When different amounts of commercial urea and crystalline urea were ap plied to the soil, 10 weeks were necessary for the chlorosis to appear on the trees which had received 60 and 80 grams of the commercial urea. No chlorosis resulted from the crystal line urea. Experiment 5. As a r...

An assessment of intracellular urea removed during haemodialysis has been made from urea extraction and plasma urea estimations. An apparent wide variation in the movement of intracellular urea in patients with acute renal failure from obstetric and traumatic causes and with chronic renal failure is reported.A method for the estimation of red cell water urea is presented. In two patients with c...

Eradication of Helicobacter pylori with currently available antibacterial agents is unsatisfactory due to the risk of side-effects and the emergence of resistance. The organism rapidly dies in vitro in the presence of urea at pH 6. When incubated in citrate buffer (pH 6) plus urea (10 mM) the five minute survival was 26% compared with 96% without urea and the survival progressively decreased wi...