Determination Of Total Activity Research Articles

Screening of endometrial carcinoma by lactate dehydrogenase isoenzyme analysis of uterine fluid.

Determination of total activity for lactate dehydrogenase (LD) as well as electrophoretic separation and quantitative determination of the individual LD-isoenzymes was performed in 431 samples of uterine fluid obtained by the Gravlee Jet Wash technique or a described simple device for endouterine aspiration. The isoenzyme pattern for each menstrual phase was characteristic. The study population included 18 patients with endouterine neoplasia. All these malignancies were characterized by increased total LD-activity and/or abnormal distribution of the individual LD-isoenzymes compared to proliferative phase and would consequently have been discriminated at postmenstrual or postmenopausal examination. The LD-enzyme technique proved to be more accurate than cytology with approximately the same number of false positives.

Determination of total activity by liquid scintillation counting and its application to aqueous effluent samples

An analytical method for determining total activity in water samples is described. The method depends on the direct relationship between the average energy deposited in a liquid scintillator solution and the channels ratio recorded for two different portions of the total energy spectrum. Calibration curves are constructed using single energy beta emitters. Samples are first counted at low gain for medium to high energy activity, followed by a second count at high gain to record total activity. Results obtained by this method for both synthetic and reactor effluent samples were quantitative (3–7%) compared with results obtained by low-background beta counting (42–100%).

Alkaline phosphatase. II. Conditions affecting determination of total activity in serum.

Results of previous experiments on isolated purified isoenzymes of alkaline phosphatase from humans have been confirmed on sera containing relatively large activities of the different isoenzymes. The most remarkable finding is that activation by N-ethylaminoethanol is much more pronounced, in the case of the intestinal and placental isoenzymes, than is activation by diethanolamine. For several reasons, it is suggested that N-ethylaminoethanol is the buffer of choice, 0.1 mol/liter concentration for routine measurements and 1 mol/liter in those cases where the determination of the intestinal or placental isoenzymes is important. Mg2+ could be omitted because its addition increases the activity only marginally. Normal values for adults with use of 0.1 mol/liter N-ethylaminoethanol are 59 +/- 36 (2 SD) U/liter (n = 126).

Alaninaminopeptidase ( L-alanyl-peptidhydrolase) im harn bei nierenerkrankungen

In a pilot study of 67 patients suffering from different diseases of the kidneys the alanine aminopeptidase (AAP) in the urine has been shown to be a suitable parameter for diagnosis and serial observations during the course of the diseases. The tubular AAP and that of the serum can be differentiated on the basis of their different electrophoretic mobility. The enzymogram of the urine increases the information received by the determination of total activity. It permits the evaluation of the tubular and filtrated components of the total AAP activity under pathological conditions.