High protein intakes elevate plasma urea and ammonia concentrations and this can be negatively associated with plasma progesterone concentrations in cows (Jordan and Swanson 1979; Jordan et al. 1983). Low plasma progesterone concentrations may compromise embryo survival and there are reports of negative relationships between protein intake and conception rate in dairy cattle (eg Jordan and Swan...

In an earlier publication’ dealing with a micro method for the estimation of urea in blood, I also described a micro method for the estimation of ammonia in blood and in organic secretions. For the determination of the ammonia two analyses are made; in the first the total urea plus ammonia is determined; and in the second the urea alone after the ammonia has been removed by evaporating the bloo...

Disorders of the urea cycle are secondary to a defect in the system that converts ammonia into urea, resulting in accumulation of ammonia and other products. This results in encephalopathy, coma, and death if not recognized and treated rapidly. Late-onset urea cycle disorders may be precipitated by acute disease and can be difficult to recognize because patients are already ill. Diagnosis of ur...

Development of a conductometric biosensor for the urea detection has been reported. It was created using a non-typical method of the recombinant urease immobilization via adsorption on nanoporous particles of silicalite. It should be noted that this biosensor has a number of advantages, such as simple and fast performance, the absence of toxic compounds during biosensor preparation, and high re...

BACKGROUND Uremic toxins are typically measured in plasma and little is known of their interstitial concentrations. We undertook experiments to validate a microdialysis technique for simultaneous recovery of small and large uremic toxins in the subcutaneous interstitial fluid (ISF). METHODS Microdialysis catheters were inserted into the subcutaneous interstitium of 8 subjects (controls and ur...