A procedure has been described whereby the high molecular weight alkaline phosphatase (slow-moving) isoenzyme may be studied by means of polyacrylamide gel electrophoresis. By treatment of sera containing this isoenzyme with some detergents of the nonionic Triton octylphenoxyethanol series, the high molecular weight alkaline phosphatase isoenzyme is altered so that its electrophoretic mobility more closely resembles that of the usual alklaine phosphatase isoenzymes. The high molecular weight isoenzyme is thought to be associated with phosphatidyl choline and/or liproproteins. The detergent action is to dissociated the alkaline phosphatase from its lipid carrier. It is thought that these lipid-alkaline phosphatase complexes are associated with liver cell fragments. The detergent altered slow-moving alkaline phosphatase may migrate as a single band, from two to four new bands, or as several new bands. Liver, bone and intestinal alkaline phosphatase isoenzymes are unaffected by detergent action.

Alkaline Phosphatase↗

PubMedDate not supplied

Use of alkaline phosphatase isoenzyme analysis in the evaluation of cholestatic liver disease.

A useful laboratory test for the differentiation of liver, bone, and intestinal alkaline phosphatase (ALP) isoenzymes in serum is presented. Electrophoresis in polyacrylamide gel is performed with untreated serum as well as with serum incubated at 56 degrees C for 10 min. The heating step denatures bone isoenzyme which may obscure the liver ALP band when present in large amounts. Visualization of ALP activity is accomplished by the use of buffered p-toluidinium 5-bromo-4-chloro-indolyl phosphate and magnesium ions. In serum of patients with cholestatic liver disease, the occurrence of large molecular weight liver cell membrane fragments which contain ALP activity is postulated. These ALP-containing fragments occur at the origin of the electrophoretogram, unable to penetrate the small pore separation gel. Abnormalities involving ALP isoenzymes, such as bone isoenzyme arising from increased osteoblastic activity, may be detected. Intestinal isoenzyme, normally present in small amounts in some subjects of blood groups B or O, may be elevated in certain liver diseases, such as cirrhosis. By the use of this method the routine question of whether an ALP found to be increased in a screening procedure is due to liver or bone abnormality may be answered. In addition, the occurrence of abnormal ALP bands arising from cholestatic conditions and the occurrence of abnormal amounts of intestinal isoenzyme may also be detected.

Alkaline Phosphatase↗

PubMedDate not supplied

Modern iron ligands useful for the measurement of serum iron.

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Humans↗

PubMedDate not supplied

Some aspects of bilirubin determination in the newborn using dimethyl sulfoxide.

Although serum bilirubin determination is a common procedure in most clinical laboratories, the test seems to be of particular importance in the screening of neonates, especially the premature or the erythroblastotic infant. However, bilirubin determination is subject to interferences, particularly in the presence of hemolysis and lipemia, which may seriously affect the results. It is, therefore, of paramount importance to the pediatrician to be aware of these potential shortcomings of the test. To improve the reliability of bilirubin determination, a method using dimethyl sulfoxide is proposed which is simple, rapid, and ideally-suited for small amounts of blood such as are commonly encountered in pediatrics. The effect of hymolysis and moderate lipemia are minimal, and the use of a sample blank can usually be eliminated in most circumstances.

Bilirubin↗

PubMedDate not supplied

Associated problems of protein electrophoresis, staining and densitometry.

The process of electrophoresis, a separation phenomenon, is mistakenly understood to include the sequential processes ancillary to analyte resolution, that is, staining and quantification, where the latter could be elution followed by photometry or integrating-calculating-densitometry. The theories involved in electrophoresis itself are well worked out and equally well understood but the problems which are associated with separation, chemical reaction to generate a chromogen and quantification, perhaps partly forgotten and perhaps partly ignored, are taken up and described here. They include albumin trail, resolution, unequivalent staining, prestaining and the densitometry problems associated with band widths, opacity effects and polychromaticities.

Blood Proteins↗

PubMedDate not supplied

Simple, direct determination of serum 5'-nucleotidase.

A simple determination of 5'-Nucleotidase in blood serum without deproteinization is described. The enzyme activity is distinguished from that of a nonspecific alkaline phosphatase by nickel inhibition and the inorganic phosphate released from adenosine monophosphate used as substrate is determined by a method previously described. Additional studies include the determination of optimal conditions for the reaction and nickel inhibition.

Alkaline Phosphatase↗

PubMedDate not supplied

Comparative sensitivities of flame atomic absorption spectrophotometry (AAS) and molecular absorption spectrophotometry (MAS).

A sensitivity comparison was made between conventional atomic absorption spectrophotometry (AAS) and conventional molecular absorption spectrophotometry (MAS) for the serum trace metals, copper, iron, and zinc. The sensitivity aspect considered was absorbances was obtained for concentrations in the solutions analyzed using unit lightpaths of 1 cm and 10 cm for MAS and AAS, respectively. A distinction was made between procedural sensitivity and measurement sensitivity where the latter represents molar absorptivity. Some was given to the concepts of procedural sensitization by concentration of the analyte through the use of lyophilization, extraction or ashing. The misuse of data obtained with scale expanders is described as a commonly occurring phenomenon of both AAS and MAS and a source of confusion in the understanding of measurement sensitivity.

Copper↗