First J. Henry Wilkinson Memorial Lecture: The clinical relevance of isoenzyme assays.
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Acid Phosphatase↗
Biomedical subjects
A Burlina
Publications and source records attributed to A Burlina.
Presidential Address: Clinical enzymology - past, present and future.
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Chemistry, Clinical↗
Liposome-incorporated enzymes: studies on amylase.
Alpha-amylase (EC 3.2.1.1) from hog pancreas was incorporated into artificial phosphatidylcholine and phosphatidylserine liposomes. To kinetically follow the enzyme-catalyzed hydrolysis of amylose the liposome-bound amylase was incubated in a medium containing amylose-iodine substrate. The reaction was studied at different concentrations of amylose and at different ionic strengths. Activation of amylase incorporated into liposomes by chloride ions varies with the type of phospholipid utilized to prepare the liposomes. Whe amylase bound to negative charged liposomes was used, a sigmoidal relationship between the reaction velocity and substrate concentration was found. Incorporation into liposomes protects amylase from heat inactivation.
Amylases↗
Studies on alkaline phosphatase isoenzymes in hepatic diseases. Relation to gamma-glutamyltransferase.
Isoenzymes of alkaline phosphatase (ALP) and total gamma-glutamyltransferase (gamma GT) have been studied in patients with increased total ALP. Fractionation of alkaline phosphatase yielded clinical information which could not be obtained by determination ALP and gamma GT alone. 1. There was a high degree of correlation between isoALP 1 (biliary band) and total gamma GT. 2. The ALP2 fraction increases after cytolysis in acute and chronic hepatitis. 3. A new ALP4 fraction appears, probably due to fibroblastic activity, in some histological types of cirrhosis.
Acute Disease↗
Improved method for fractionating gamma-glutamyltransferase by electrophoresis on cellulose acetate.
I describe a method of fractionating gamma-glutamyltransferase on cellulose acetate. The tracing is obtained in parallel with that of serum protein, and the gamma-glutamyltransferase bands are characterized by correspondence with the major protein fractions. The overall pattern of the isoenzyme activity in normal sera is one of activity in the alpha1- and alpha2-globulin regions. In hepatic diseases four bands are usually present, but some more specific observations are possible, e.g., the presence of an intense beta-globulin band in occlusive icterus, intra- or extrahepatic, and a marked alpha2-globulin band in alcoholism. The potentialities of this technique as a diagnostic and prognostic aid together with its simplicity prompt me to recommend its use in the clinical laboratory.
Electrophoresis, Cellulose Acetate↗
Clinical importance of lipase determination by the turbidimetric procedure as compared with determination by a chromatrographic procedure.
The turbidimetric determination of serum lipase activity was compared with the chromatographic determination in three groups of patients, including patients affected by hepatic diseases, patients affected by pancreatic diseases and a control group. The two methods were also compared in the determination of lipase activity of human leucocytes in vitro. The results show that there is a good statistical correlation of lipase turbidimetrically determined at pH 9.15 and amylase in serum of normal individuals and in serum of patients with pancreatic diseases. There is no correlation between amylase and chromatographically determined lipase. The other types of lipase activity determined, i.e. turbidimetrically assayed at pH 5.5 and chromatographically assayed both at pH 5.5 and at pH 9.15, might be related to a different non-pancreatic enzymatic activity which is likely to lack diagnostic value. This suggests that methods of lipase determination based, for instance, on fatty acid liberation are of limited value in clinical studies on lipase.
Adult↗
Characteristics and behaviour of arylesterase in human serum and liver.
Human arylesterase is localized in liver microsomes where the presence of different electrophoretic bands corresponding to the serum bands can be recognized. Serum arylesterase is mainly a result of liver activity and its high level might be explained by a low rate of elimination in urine. The behaviour of arylesterase towards inhibitors shows certain similarities to that of some of the proteases, such as trypsin. The clinical value of serum arylesterase determination in assessing liver function is confirmed by its isoenzyme behaviour in cirrhosis and porto-caval shunt.
Adolescent↗