Gastric contamination of postmortem blood samples during blind-stick sample collection.

A blood sample drawn by a blind stick through the chest was collected for toxicologic examination in a suspected natural death. Drug screen results on the blood sample indicated a combined overdose of alcohol and amitriptyline. An autopsy was later performed and a peripheral blood sample was drawn. A drug screen of this sample showed the presence of therapeutic quantities of amitriptyline and a trace of alcohol. Cytologic examination of the blind-stick sample showed the presence of columnar cells and food debris, confirming that the sample was contaminated either by stomach contents or gastric aspirate during the collection procedure. We strongly encourage all agencies to refrain from the use of blind-stick sample collection for toxicologic specimens.

Prostatic acid phosphatase by radioimmunoassay. Sensitivity compared with enzymatic assay.

Prostatic acid phosphatase values in 98 patients with prostatic carcinoma were measured by a commercial radioimmunoassay (RIA) and by enzymatic assay. Forty-three carcinomas were staged by rigorous pathological criteria. Patients (N = 129) with benign prostatic hyperplasia were the control group. At 94% specificity, sensitivities of the RIA vs the enzymatic assay for clinically staged patients were as follows: stage A, 22% vs 6%; B, 29% vs 10%; C, 52% vs 38%; and D, 87% vs 80%. However, none of the seven patients with pathological stage A and B disease had a positive test result, and we suggest that variability in staging criteria accounts for the discrepant sensitivity claims reported. Prostatic acid phosphatase RIA should not be used for screening but as an adjunct for staging known prostatic carcinoma.