Determination creatinine

Perform periodic urinalysis, BUN, and creatinine determinations during therapy with penicillinase-resistant penicillins, and consider dosage alterations if these values become elevated. 

The limitations of the Jaffe method for creatinine determination are discussed under Assessment of Renal Injury by Serum Chemistry . Exogenous creatinine clearance compensates for the insensitivity of the method as well as the interference by endogenous chromagens by artificially increasing the plasma creatinine concentration (Finco 1997). 

In situations when the GFR has been determined by accurate invasive clearance methods, either serum cystatin C or creatinine might be used to follow changes in GFR. However, as long as the precision of the methods for creatinine determination is higher than that of the methods for cystatin C determination, there are presently no valid reasons to use serum cystatin C for this purpose, particularly since creatinine determinations generally are cheaper than cystatin C determinations. 

Fig. 10. The cross section and chemistry of Eastman Kodak s Ektachem slide for serum creatinine determination.

Scheller s group [87] generated creatinine-specific antibodies for sensitive and specific immunochemical creatinine determinations in a reusable sensor. The creatinine sensor was constructed by fixing a creatinine-modified membrane on top of a platinum working electrode, which was then incorporated into a stirred electrochemical measuring cell. For creatinine... 

Campins, P. Tortajada, L.A. Meseger, S. Blasco, F. Sevillano, A. Molins, C. Creatinine determination in urine simples by batchwise kinetic procedure and for injection analysis using the Jaffe reaction Chemometric study. Talanta 2001, 55, 1079-1089. 

El37 Datta, P., Graham, G. and Schoen, I. (1984). A paraprotein phenomenon evidenced by interference with creatinine determination in sera of multiple myeloma patients. Clin. Chem. 30, 968, Abstr. 145. 

E23I Souney, P.F. and Mariani, G. (1985). Effect of various concentrations of flucytosine on the accuracy of serum creatinine determinations. Am. J. Hosp. Pharm. 43, 621-622. 

E356 Knoll, E., Ratge, D. and Wisser, H. (1987). Creatinine determination with the Kodak Ektachem DT-60 compared with Fuller s earth method. Ann. Clin. Biochem. 24, Suppl. 2, 92-93. 

E566 Slack Mauro, L., Mauro, V.F., Miller, P.C. and Lacher, D.A. (1989). Effect of cefotetan on creatinine determination by picric acid and enzymatic methods. Clin. Pharm. 8, 505-508. 

Kridde, G., Hirschberger, J. and Zerback, R. (1991). Creatinine determination in veterinary medicine with the Reflotron system. Clin. Chem. 37, 1065-1066, Abstr. 743. 

Ambrose RT, Ketchum DF, Smith JW. Creatinine determined by high performance liquid chromatography. Clin Chem 1983 29 256-9. 

Weatherburn MW, Trotman RBB, Jackson SH. Specific method for serum creatinine determination based on ion exchange chromatography and an automated alkaline picrate reaction A proposed reference method. Clin Biochem 1978 11 159-66. 

Baseline liver function tests (AST, ALT, bilirubin, prothrombin time), serum creatinine determination, and urinalysis should he obtained on admission and repeated at 24-hour intervals until at least 96 hours have elapsed for those at risk. Most patients with hver injury develop elevated transaminase concentrations within 24 hours of ingestion. Transaminase concentrations greater than 1000 lU/L commonly are associated with other signs of hver dysfunction and have been used as the threshold concentration in outcome smdies to define severe liver toxicity. The extent of transaminase elevation is not correlated directly with severity of the hepatic injury, with nonfatal cases demonstrating peak concentrations as high as 30,000 lU/L between 48 and 72 hours after ingestion. ... 

For the diagnosis of kidney function, creatinine determinations in serum are increasing in popularity over urea measurements, since the creatinine level is not affected by a high protein diet or by metabolic rate, as is the case for urea. Enzymatic methods use either creatinine amido-hydrolase (EC 3.5.2.10) or creatinine iminohydrolase (EC 3.5.4.21) ... 

Jnng, K., C. Wesslan, F. Priem, G. Schreiber, and A. Znbek. 1987. Specific creatinine determination in laboratory animals using the enzymatic test kit Creatinine-PAP. Journal of Clinical Chemistry and Clinical Biochemistry 25 357-361. 

Okudo, T., J. Ito, and M. Nishida. 1984. Interferovalue indicates the interference of substances with creatinine determination. Clinical Chemistry 30 1888-1889. 

Walsh DA and Dempsey E (2002) Comparison of electrochemical, electrophoretic, and spectrophotometric methods for creatinine determination in biological fluids. Analytical Chimica Acta 459 187-198. 

CDU should be reported as ng Cd/g CRTU, whiie B2MU should be reported as ng B2M/g CRTU. To derive the ratio of cadmium or B2M to creatinine, CRTU shouid be reported in units of g crtn/l of urine. Depending on the analytical method, it may be necessary to convert results of creatinine determinations accordingly. 

Pataki [121] has detected creatinine in urine on cellulose-D-layers. This procedure enables the creatinine to be separated from other JafF6-chromogens which interfere in the colour reactions on which many methods of determination are based. Quantitative evaluation of the creatinine spots, obtained using picric acid/sodium hydroxide, is possible since there is a linear relation between the square root of the spot surface area and the logarithm of the amount of substance applied (see p. 136) [122]. The rehabihty of the creatinine determination has been tested by parallel determinations of various amounts of creatinine in standard solutions and in urine. Tests on recovery gave a value of 95.7 3.4% of the creatinine added. Up to 20 (xg creatinine or ca. 20 [xl urine can be used in one determination larger amounts can lead to overloading of the layer. 

As a check on the completeness of the collection, particularly in long term studies, measurement of the urinaiy creatinine excretion (98) is frequently valuable. In such studies, 17-ketosteroid values which are grossly aberrant are frequently associated with aberrant values of urinary creatinine, indicating faulty collections. The creatinine determinations have little value when only one or two specimens are collected from a single patient. 

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