Bilirubin, measurement

In Table 29.5 sorption capacity of a fibrous carbon (activated carbon felt, MAST Carbon International), experimental deliganding carbon felt and mass-fractal (a = - 2.39) HSGD carbon towards methylene blue and unconjugated bilirubin, measured in batch experiments are compared. 

Total bilirubin measures both direct and indirect indirect bihrubin is calculated from the total minus the direct bilirubin. Bilirubin levels reflect the balance between production and excretion there is no normal level of bilirubin (Table 6.3) and levels may be affected by a number of factors (Table 6.4). 

E211 Kubasik, N.P., Mayer, T.K., Bhaskar, A.G., Sine, H.E. and D Souza, J.P. (1985). The measurement of fractionated bilirubin by Ektachem film slides. Method validation and comparison of conjugated bilirubin measurements with direct bilirubin in obstructive and hepatocellular jaundice. Am. J. Clin. Pathol. 54, 518-523. 

E458 Maisels, M.J. (1988). Bilirubin measurement problems. Reply to a letter. Pediatrics 82, 809. 

E476 Pettigrew, A.R., Orrell, J.M. and Dominiczak, M.H. (1988). Mobile laboratory unit based on the Kodak Ektachem DT system. Clin. Chem. 34, 2313-2315. E477 Pleasure, J.R. (1988). Bilirubin measurement problems. Pediatrics 82, 808-809. E478 Price, G., Cate, J. and Skogen, W. (1988). Evaluation of LDL cholesterol by a commercial heparin affinity chromatography method. Clin. Chem. 34, 1228-1229, Abstr. 370. 

E483 Rosenthal, P., Keefe, M.T., Henton, D. and Cheng, M.H. (1988). The Ektachem system for unconjugated bilirubin measurement in the neonate. Clin. Chem. 34,... 

EN25 Franzini,C. and Cattozzo, G. (1991). Azopigments from serum biliprotein and accuracy of total bilirubin measurement. Clin. Chim. Acta 203, 339-342. 

EN48 Langbaum, M., Farber, S. and Rosenthal, P. (1991). Kodak Ektachem total bilirubin and neonatal bilirubin measurements in newborns - is a distinction clinically relevant Clin. Chem. 37, 987-988, Abstr. 370. 

EN59 Newman, T.B., Hope, S. and Stevenson, D.K. (1991). Direct bilirubin measurements in jaundiced term newborns. Am. J. Dis. Child. 145, 1305-1309. 

EN125 Pickert, A., Riedlinger, 1. and Stumvoll, M. (1992). Interference of Cefotiam with total bilirubin measured with the Ektachem analyer. Clin. Chem. 38, 599-600. 

Khabbaza, E.J. and Lott, J.A. (1983). Evaluation of the Ames Seralyzer for the determination of whole blood hemoglobin. Clin. Chem. 29, 1212, Abstr. 173. Moussa, F., Levillain, P. and Trivin, F. (1983). Improvement on bilirubin measurement by Ames Seralyzer analyser. Clin. Chem. 29, 1262, Abstr. 560. 

Kolinski B, Kuster H, Ugele B, Gruber R, Horn K. Total bilirubin measurement by photometry on a blood gas analyzer potential for use in neonatal testing at the point of care. Clin Chem 2001 47 1845 7. 

Extrahepatic biliary atresia may involve all or part of the extrahepatic bifiary tree. The gallbladder is usually absent. Involvement of the hepatic or common duct leads to the characteristic syndrome of severe cholestatic jaundice. It occurs in 1 in 10,000 births, with females more commonly affected than males. Jaundice and pruritus usually appear in the first week. Stools are pale and the urine is tea colored. Jaundice is deep, but the aminotransferases are only mildly elevated. If jaundice persists beyond 14 days of age, a direct or conjugated bilirubin measurement must be performed to exclude biliary atresia. If it is elevated, the urine should be tested for bile and the stool color inspected if the color is not green or yellow, biliary atresia is likely. Early identification of this condition is essential if these infants are to benefit fi"om the operation of portoenterostomy, which should be performed no later than 60 days after birth. If portoenterostomy is not successful, liver transplantation is the treatment of choice. Children rarely live beyond 3 years unless the lesion is surgically correctable. 

Maisels MJ, Kring E. Transcutaneous bilimbinometry decreases the need for serum bilirubin measurements and saves money. Pediatrics 1997 99 599-601. 

Amniotic fluid bilirubin measurements are of value in the detection of risk in rhesus incompatibility. 

Although it is possible to measure both total and conjugated (direct) bilirubin, measurement of total bilirubin is usually sufficient because plasma total bilirubin levels are lower in laboratory animals compared to humans. If plasma total bilirubin is markedly elevated, it imparts a visible yellow color to the plasma. Plasma total bilirubin values in rats and dogs are near the limit of detection by common colorimetric methods, which rely on diazotization reactions with bilirubin concentrations in rats... 

Increased nonconjugated (indirect) bilirubin Shortened red cell survival time as measured by injection of autologous Cr-labeled red cells... 

Unfortunately, Perkin-Elmer whcTiras produced this instrument has built the instrument for the purpose of measuring bilirubin in amniotic fluid. As a result, the instriment does not read above a level of approximately 2 mg/100 ml. Therefore, it is necessary to dilute the serum from newborns in order to be read in this instrument. However, if one standardizes by making a 1 to 5 dilution of all newborn serum, one can use this method for screening purposes. One looks forward to the further development of this instrument so that readings can be made over a wide range. 

The Group II (biliary tract) enzymes are abnormal usually when the serum bilirubin concentration is also abnormal. Most commonly used is alkaline phosphatase which is a highly sensitive indicator of biliary tract obstruction, perhaps because the enzyme is synthesized as an induced response to obstruction of even small bile ducts. Most techniques used to identify the origin of an elevated serum alkaline phosphatase are not very useful from a clinical viewpoint (23). The simultaneous measurement of GMT activity has been found to be useful in differentiating between the hepatic and bony origin of alkaline phosphatase. An increased GMT activity in a patient with an increased ALP activity is a good indication that there is biliary biliary tract disease (62,63). 

Solberg and co-workers have applied discriminate analysis of clinical laboratory tests combined with careful clinical and anatomic diagnoses of liver disease in order to determine which combinations of the many dozen liver diagnostic tests available are the bes t ( ). These authors found that the measurement of GPT, GMT, GOT, ALP and ceruloplasmin were the most useful enzymatic tests, when combined with other non-enzymatic tests such as the measurement of bilirubin, cholesterol, hepatitis-B associated Australian antigen, etc. Another group of highly useful enzymes, not discussed in this review, are those clotting factors and the enzyme cholinesterase which are synthesized by the liver cells. 

The oncologist prescribes the normal doses of idarubicin 12 mg/m2 IV daily for 3 days and cytarabine 100 mg/m2 per day by continuous infusion for 7 days to treat her acute myelogenous leukemia. Her baseline laboratory measurements are significant for an elevated WBC count, a creatinine concentration of 2.5 mg/dL (221 pmol/L), and a bilirubin level of 1.6 mg/dL (27 pmol/L). 

Bilirubin is diazotized with para-sulphonyl benzene diazonium compound and the absorbance of the resulting azobilirubin is measured at 600 nm to determine bilirubin level in the biological fluid e.g., blood serum. In usual practice, a serum blank is run simultaneously by reacting the serum with caffeine, sulphanilic acid and tartaric acid, and the absorbance of the blank is measured at 600 nm which is subsequently subtracted from the azobilirubin absorbance initially obtained before the bilirubin level is finally determined. 

There are a few medicinals that cause increased bilirubin levels which ultimately enhances AP-levels unless and until a corrective measure is taken in the respective procedure one may be left with false AP-level enhancement. Some typical examples are, namely amitriptyline, chloropropamide, erythromycin, phenylbutazone, sulpha-drugs and tetracyclines. 

An RP-HPLC technique was employed for the analysis of bilirubin, one of the main components of pigment gallstones. The aim of the study was the determination of the inhibition of chlolesterol crytallization under bilirubin deconjugation. Bilirubin in rat bile was measured in an ODS column (250 X 4.5 mm. i.d. particle size 5 pm). Separation was... 

Hepatic Effects. An increase in serum iron, which may reflect an adverse liver effect, was observed in workers exposed for 6 months to phenol in a wood treatment liquid (Baj et al. 1994). Elevated concentrations of hepatic enzymes in serum, and an enlarged and tender liver suggestive of liver injury, were reported in an individual who had been exposed repeatedly to phenol vapor for 13.5 years (Merliss 1972). Since phenol was also spilled on his clothes resulting in skin irritation, dermal and inhalation exposures were involved. A 2-fold increase in serum bilirubin was observed in a man who was accidentally splashed with a phenol solution over his face, chest wall, hand, and both arms (Horch et al. 1994). Changes in liver enzymes were not observed in persons exposed to phenol in drinking water for several weeks after an accidental spill (Baker et al. 1978). This study is not conclusive because the measurements were completed 7 months after the exposure. 

Population PK screening in Phase II and Phase III is useful in assessing the impact of altered hepatic function (as a covariate) in PKs, if those patients are not excluded from Phase II and III trials, and if there is sufficient PK information collected about the patients to characterize them reasonably well. If a population PK approach is used, patients in Phase II and III studies are assessed for encephalopathy, ascites, serum bilirubin, serum albumin, and prothrombin time (which are components of the Child-Pugh score) or a similar group of measures of hepatic function. The population PK study, then, would include the following features ... 

Wolfgarten Bilitec 2000, measuring bilirubin at More bile in stomach of GORD First report using genuine age-... 

A7b. Arvan, D. A., and Ritz, A., Measurement of serum albumin by the HABA-dye technique A study of the effect of free and conjugated bilirubin, of bile acids, and of certain drugs. Clin. Chim. Acta 26, 505-516 (1969). 

In assessment of optimal incubation conditions it is advisable, as is frequently done in work with less costly substrates, to measure the activities as a function of the parameter considered at two time points along the velocity-time curves. A survey of available techniques for assaying conjugated bilirubin (Section 4) shows that the possibilities of miniaturization, e.g., by reducing the total volumes of the incubations mixtures without changing the relative concentrations of their components, have seldom been exploited. 

---