The Clinical Measurement Ontology (CMO), Measurement Methods Ontology (MMO), and Experimental Condition Ontology (XCO) are currently being developed at the Rat Genome Database. For more information about these vocabularies please see Shimoyama et al. Three ontologies to define phenotype measurement data. Front Genet. 2012;3:87. Epub 2012 May 28 or contact us (https://rgd.mcw.edu/rgdweb/contact/contactus.html).
The level of urea in terms of nitrogen content found in a specific volume of serum, i.e. blood plasma from which clotting factors have been removed. The urea nitrogen level is converted to urea concentration by multiplying by 60/28 or 2.14. Urea is the chief nitrogenous end product of protein metabolism in whole blood.Urea is formed in the liver from amino acids and from ammonia compounds and is found in urine, blood, and lymph.