| FENa, FENa | fractional excretion of sodium |
|---|---|
| FFE | fast field echo; fecal fat excretion |
| NAE | net acid excretion |
| PEI | Patient Exit Interview; phosphate excretion index; physical efficiency index; polyethyleneimine |
| RER | renal excretion rate; respiratory exchange ratio; rough endoplasmic reticulum |
| undetermined nitrogen | The nitrogen of blood, urine, etc., other than urea, uric acid, amino acids, etc., that can be directly estimated; in blood it amounts to about 25 mg per 100 ml. Urea nitrogen, the portion of nitrogen in a biological sample, such as blood or urine, that derives from its content of urea. See: blood urea nitrogen. (05 Mar 2000) |
|---|---|
| urinary nitrogen | Nitrogen excreted as urea, amino acids, uric acid, etc., in the urine; 1 g of urinary nitrogen indicates the breakdown in the body of 6.25 g of protein. See: nitrogen equivalent. (05 Mar 2000) |
| filtrate nitrogen | Nonprotein nitrogen in various compounds that normally pass through the glomerular filtration, or through a filter in the laboratory (after proteins are precipitated). (05 Mar 2000) |