Plasma zinc levels were measured in both healthy and diabetic individuals having an age range of 10–93 years. No significant differences in plasma zinc concentrations were found between males and females in either healthy or diabetic individuals. Up to the age of 50 years, the mean plasma zinc of normal individuals remained relatively constant at 70 ± 32µg/100 ml ( ± 2 SE) after which the levels decreased. This decreasing pattern was absent in diabetics, whose plasma zinc of 65 ± 32µg/100 ml remained constant over the entire age range. For women on oral contraceptive agents, the mean plasma zinc was 59 ± 18 µg/100 ml, which was significantly lower than that of controls.

In this study we observed the discriminative ability of five commonly measured laboratory tests to distinguish between gallstone- and non-gallstone-associated pancreatitis. We also assessed the ability of the lipase-amylase ratio to discriminate between alcohol- and non-alcohol-induced pancreatitis. One hundred sixty-two patients with acute pancreatitis were included in the study. Group A consisted of patients presenting to our hospital in 1988 and 1989. Group B consisted of patients presenting in 1992. Models developed using group A patients were validated using group B patients. For gallstone pancreatitis, AST (threshold value 80 IU/liter) alone and a three-factor model, AST, ALP and bilirubin (threshold values of 80 IU/liter, 115 IU/liter, and 15 mumol/liter, respectively) were the best predictors, correctly classifying at least 80% of cases in group A and B. A lipase-amylase ratio of two correctly classified only 48% of cases in group A and 54% in group B. We conclude that biochemical models are useful in predicting the presence of gallstone pancreatitis but not alcoholic pancreatitis.

Determination of zinc in blood plasma by flameless atomic absorption spectrometry is discussed, with particular reference to the protocol required for the successful use of the Varian-Techtron Carbon Rod Atomizer. Cup aging is shown to be an important factor in limiting the precision of this analytical technique and ways of minimizing the problem are described. Matrix problems have also been encountered, which precluded the use of aqueous standard curves and the method of standard additions. We propose the use of plasma in preparing standard curves, the values for which are corrected for inherent plasma zinc, as a possible solution to the problem.