1,720,984 research outputs found
Determination of serum theophylline by apoenzyme reactivation immunoassay system
No full textSummary: A reagent strip for the quantitative analysis of theophylline in serum or plasma was evaluated. The strip is based on the apoenzyme reactivation immunoassay system (ARIS) technique and is intended for use with the Ames Seralyzer reflectance photometer. The method gave CVs at three theophylline levels ranging from 3.8 to 6.3% (within run) and from 2.8 to 6.9% (day to day). The regression lines obtained from the correlation studies were y = 0.959* + 0.51 (n = 105, r = 0.9906, S„x= 0.56) for the comparison ARIS (y) versus Syva enzyme multiplied immunoassay (x) methods, and y = 0.986* + 0.32 (n = 105, r = 0.9832, Sylx= 0.62) for the comparison ARIS (y) versus Abbott TDx fluorescence polarization immunoassay (x) methods. The interference from triglycerides, hemoglobin, bilirubin, and ascorbic acid, and the cross-reactivity of 8-chlorotheophylline, caffeine, 1,3-dimethyluric acid, theobromine, and 1,7-di-methylxanthine, were also investigated and discussed. The method was found to be reliable, simple, and rapid. It provides a practicable solution for immediate determinations of theophylline. © 1985 Raven Press
Precipitation method for separating and quantifying bone and liver alkaline phosphatase isoenzymes.
No full textWe evaluated a method for quantifying bone isoenzyme of alkaline phosphatase (ALP) which utilizes wheat-germ lectin to precipitate this traction. In precision studies, CVs ranged from 3.2 to 11.4% (within-day) and from 3.7 to 11.5% (day-to-day). The assay procedure was linear to 1100 U/L and was easily adapted to automated kinetic measurement. Comparison of the precipitation method with an affinity electrophoretic method, which utilizes cellulose acetate as a support, demonstrated a satisfactory coefficient of correlation (r = 0.886). The reference range was determined in sera from 188 healthy adult subjects. The distribution of bone ALP values was also studied in 73 healthy children and in 30 healthy adolescents. To evaluate the clinical applicability of the method, the bone isoenzyme was determined in samples from several groups of subjects (pregnant women, patients with hepatobiliary diseases, patients with hepatocellular carcinoma without skeletal involvement, and patients with bone, liver or lymph node metastases). We found the method suitable for routine determination of bone alkaline phosphatase and for the screening of bone metastases. Because of its technical simplicity and satisfactory analytical performance, it can be used instead of the heat-inactivation procedure
Tubular proteins and enzyme content in the amniotic fluid.
No full textAmniotic fluid is the product of many substances and fetal urine is considered to be one of the principal components. Only a few reports have been published describing the concentration of microglobulins and urinary enzymes in the amniotic fluid. We determined the levels of alpha(1)-m, beta(2)-m, AAP and NAG, in 154 samples of amniotic fluid (103 early determinations and 51 late determinations) as a function of gestational age. We observed a statistically significant decrease in concentration of alpha(1)-m (P < 0.001), beta(2)-m (P < 0.01) and AAP (P < 0.001) when early and late amniotic fluid samples were compared. A statistically significant increase of NAG (P < 0.01) and creatinine (P < 0.01) was also found. A significant correlation was observed between alpha(1)-m and beta(2)-m, and between AAP and NAG, respectively. The potential role of urinary enzyme and microglobulin determination in amniotic fluid as an index of fetal kidney development, is discussed
Measurement of tryptase in endoscopic gastroduodenal biopsies: distribution and relationship with ulcer disease
No full textTryptase, a serine endoprotease, was determined in mucosal biopsies from fundus, corpus, antrum and corpus-fundus of the stomach and from the duodenum in 15 controls, 66 patients with duodenal ulcer, 22 with gastric ulcer and 9 with duodenitis. Intra- and inter-assay coefficients of variation ranged from 3.3% to 8.0% and from 3.5% to 8.6%, respectively. In controls, the highest values for tryptase were found in the fundus and progressively decreased in the corpus, antrum and duodenum. Analysis of variance of data from repeated measurements, performed in six subjects having multiple determinations, achieved statistical significance (F = 16.85, P < 0.001). Data from the corpus-fundus area documented a significant difference among patient groups (F = 2.70, P < 0.05). Patients with an active gastric ulcer had higher mean values when compared to controls and to patients with healed gastric ulcer. A similar trend was found in patients with active duodenal ulcer. Furthermore, corpus-fundus tryptase evaluated longitudinally in three patients with an active ulcer (point A) and after healing (point B), showed significant decrease from point A to point B. By contrast it remained elevated or showed only minor decrease in two patients with a persistent active ulcer. © 1992
CPK and CPK-MB in the early diagnosis of acute myocardial infarction and prediction of infarcted area
No full textThis study was carried out on patients of a coronary unit to evaluate the diagnostic efficiency of total CPK and CPK-MB by using different analytical techniques: catalytic, immunoassisted, cellulose acetate electrophoresis, radioimmunoassay and immunoradiometric assay. The behaviour of the enzyme was studied in all patients with reference to the localization and extent of the infarct. In all cases a diagnostic algorithm was followed based on the combined use of CPK and its MB isoenzyme; the activity was measured twice, at three-hour intervals after admission. In this way the utilization of total CPK and MB isoenzyme allows almost complete diagnostic efficiency within the first 9 hours from onset of chest pain, together with the possibility of calculating the slope of the curve of MB isoenzyme release useful for calculating infarct size. Maximum diagnostic efficiency is also obtained in cases of small infarcts, with silent ECG, and those difficult to classify clinically. © 1984 The Canadian Society of Clinical Chemists
Enzyme immunoassay for pancreatic lipase: Comparison with turbidimetric method in pancreatic diseases
No full textWe report the results of the analytical and clinical evaluation of a specific enzyme immunoassay for determination of human pancreatic lipase, in comparison with a turbidimetric method, in pancreatic pathology. Under standardized conditions of incubation time and temperature we found intraassay coefficient of variation (CV) of 1.3, 3.2, 2.1% at x- = 18.7, 43.7, 224 μg/L and interassay CV of 2.8, 4.6, 3.0% at x- = 19, 42.6, 230 μg/L, respectively. In general, a good correlation (r = 0.97) was found between lipase determined as a protein or through its catalytic activity. No significant correlation (r = 0.38) was observed with samples containing low concentration of lipase (up to 18 μg/L). We conclude that the turbidimetric method is reliable for routine determinations in the diagnosis of acute pancreatic pathology. However, the better sensitivity of the immunochemical assay should provide additional information for monitoring pancreatic insufficiency. © 1985
- …
