Effect of Dextran 40 and aprotinin on experimental acute pancreatitis.

This study examines and compares the prophylactic role of aprotinin and Dextran 40 in acute pancreatitis. Experimental acute pancreatitis was induced in 70 male Wistar rats using the closed-duodenal-loop technique. The rats were randomly divided into four groups; sham operation, untreated acute pancreatitis, and therapy with aprotinin or Dextran 40. Samples of blood and urine were collected at the beginning and at the end of the 24-hr period for measurement of amylase and creatinine which allowed calculation of the amylase-creatinine clearance ratio (ACCR). Mortality in the aprotinin group was the same as the untreated rats (20%). Dextran 40 therapy was associated with a lower mortality rate (6.7%). Light microscopic examination confirmed that the histologic changes of acute pancreatitis were less severe in both the aprotinin- and Dextran 40-treated rats. The ACCR was elevated after Dextran 40 therapy, which was due mainly to high urinary amylase levels. These results suggest that Dextran 40 may have a prophylactic role in acute experimental pancreatitis but again emphasizes the high false-positive rate of the ACCR determination.

Evaluation and comparison of radio-, fluorescence, and enzyme-linked immunoassays for serum thyroxine.

We have compared three analytical systems for the measurement of serum thyroxine: enzyme-linked immunoassay (EIA), fluorescent immunoassay (FIA) and a radioimmunoassay (RIA). These were evaluated with respect to their precision, accuracy, analytical sensitivity and sample throughput. The RIA is more sensitive than the EIA (10 microgram/L vs. 35 Ug/L. Both systems have excellent precision (X = 86 ug/L, C.V.RIA = C.V.EIA = 4.6%). Both the EIA and RIA demonstrate good accuracy with recovery of between 97-98% of added thyroxine. The FIA has an apparent sensitivity between that of the RIA and EIA (25 microgram/L), but a precision consistently lower than the other two systems (C.V. = 7.4%, X = 86 microgram/L). Patients' results by RIA compared well with those from EIA )r = 0.91, P less than 0.05), but a poor correlation was found with FIA (r = 0.865, P greater than 0.05). Although not fully automated, the EIA performed on the Abbott ABA-100 analyzer has a sample throughput equal to the automated RIA system (Micromedic, Concept 4).