A simplified radioenzymatic assay for chloramphenicol was developed by eliminating the need for cumbersome extraction procedures. After the acetylation of chloramphenicol with [14C]acetyl coenzyme A in the presence of chloramphenicol acetyltransferase, the reaction mixture was added to a toluenebased scintillation fluid. Since "4C-acetylated chloramphenicol is more soluble than [14C]acetyl coenzyme A in toluene, the radioactive product could be counted directly. The rapidity of this assay, as well as its accuracy, precision, and specificity, makes it particularly suitable for clinical use. In contrast to previous reports of enzymatic assays for chloramphenciol, we have found that results of the assay of standards prepared in serum were up to 25% higher than those of standards prepared in saline, cerebrospinal fluid, or urine.Renewed interest in the clinical use of chloramphenicol is based on its value in treating: (i) anaerobic infections, especially those involving penicillin-resistant Bacteroides fragilis; (ii) meningitis in which ampicillin-resistant Haemophilus influenzae is suspected or proven (1); and (iii) ventriculitis in which penetration of aminoglycosides into the cerebrospinal fluid (CSF) may be inadequate (4).We have developed a simplified radioenzymatic assay for chloramphenicol. Like that previously described (2, 5), it is based on the specific acetylation of chloramphenicol with [14C]acetyl coenzyme A by chloramphenicol acetyltransferase. Unlike the previously described enzymatic assays, our method allows the direct extraction of 14C-acetylated chloramphenicol into scintillation fluid and circumvents more cumbersome extraction methods. In contrast to the previous reports, we find a substantial difference between the acetylations of chloramphenicol standards in serum and in saline, CSF, or urine.

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At our resident-run clinic in an underserved community, laboratory test costs in 2013 exceeded the government subsidy by $400 000. To optimize limited resources and improve patient care, an education program to reduce testing was implemented.Between November 2014 and January 2015, residents attended lectures on utilization of laboratory testing, focusing on standard practice guidelines, and analyses of unnecessary tests. Multivariate nonparametric statistical methods and subgroup analysis were used to evaluate cost reduction.There were 453 clinic visits during the intervention period and 471 visits during the control period. Lectures were independently associated with a significant laboratory cost reduction. Median laboratory cost per visit decreased from $106.00 to $74.00. Total cost in the study period decreased from $79 403 to $51 463. There were similar reductions of laboratory costs in two subgroups: age groups of <50 years and ≥50 years, new encounters, and follow-up visits . In the analysis of individual tests, the cost of TSH and Vitamin D tests had the greatest reduction ($8176 and $5088 respectively).An appropriate physician education program can reduce laboratory tests and costs. Screening tests with inadequate evidence support were reduced most, whereas those with proven benefits did not decrease significantly.

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