Characterization of a military training site containing 232Thorium.

Understanding contaminant distribution is critical to selection and implementation of effective and affordable containment and remediation efforts. This article describes the characterization of soil containing thorium at a training site on Kirtland Air Force Base, Albuquerque, NM. The site has been used by the Defense Nuclear Weapons School since the early 1960's to train personnel in emergency response to nuclear weapons accidents and for characterization and containment of radioactive contamination. The purpose of work reported herein is to describe the primary location and migration pattern of 232Thorium (232Th) and 232Th progeny (decay products) at the site. Soil containing thorium oxide (ThO2) was applied to the site for approximately 30 years (early 1960-1990) and was used to simulate a plutonium release from a nuclear weapons accident. Data presented indicate that surface 232Th and 232Th progeny at approximately 5 times background levels are approaching test site boundaries. However, the data also indicate that vertical migration has not exceeded 0.9 m because of the insoluble nature of ThO2. The major mechanisms of 232Th mobility appear to be surface migration mediated by precipitation runoff and wind-blown soil.

Evaluation of Gonozyme, an enzyme immunoassay for the rapid diagnosis of gonorrhea.

A new indirect enzyme immunoassay (EIA), Gonozyme (Abbott Laboratories), was assessed for rapid detection of gonococcal antigens. A correlation of optic density (OD) readings by EIA with colony counts of serial dilutions of Neisseria gonorrhoeae ATCC 19424 disclosed that EIA detected 10(3) CFU/ml at OD readings of 0.1 to 0.3, that EIA consistently detected greater than or equal to 10(4) CFU/ml at OD readings of 0.6 to 1.3, and that concentrations of greater than or equal to 10(5) CFU/ml were associated with OD readings of greater than or equal to 2.0. The clinical usefulness of Gonozyme was evaluated by comparing results of EIA with those of Gram stain (GS) and culture for N. gonorrhoeae from urethral and endocervical swabs obtained prospectively in 886 randomly selected patients attending a clinic for sexually transmitted diseases. The patients evaluated included 83 female contacts of men with gonorrhea and 56 patients seen at the clinic for test of cure. In tests with 295 males, the sensitivities of GS and EIA were 91.3 and 97.1%, respectively, and both tests had specificities of greater than 96%. In tests with 591 females, the sensitivities of GS and EIA were 51.4 and 96.4%, respectively (P less than 0.0001, Z proportionality test), and the specificities were 98.7 and 86.5%, respectively (P less than 0.0001). In tests with 61 females and 3 males, EIA was positive, whereas GS and cultures were negative for N. gonorrhoeae. Gonozyme is a highly sensitive method for rapid detection of gonococcal antigens. EIA is comparable to GS for males and more sensitive though less specific than GS for females. Possible reasons for the lower specificity of EIA for females are discussed. Due to its high negative predictive value for female contacts, EIA offers an alternative to epidemiological treatment of contacts before culture results.

Dosage of antituberculous drugs in obese patients.

There are no published data defining efficacious drug therapy for obese patients with active tuberculosis. Current dosage recommendations are based on total body weight (TBW); drug toxicity might result in obese patients receiving TBW doses. Peak and trough serum levels were measured for rifampin, streptomycin, ethambutol, and pyrazinamide in an obese patient (166 kg TBW, 87 kg ideal body weight (IBW] with miliary and meningeal tuberculosis. The observed drug levels and the calculated serum half-lives of these drugs were compared with the expected serum levels and serum half-lives in lean patients treated with literature-recommended doses. The observed serum levels in our obese patients were within the expected range for lean patients when dosage was based on IBW rather than on TBW. The observed cerebrospinal fluid penetrations of the drugs studied in our obese patient were similar to those reported in lean patients.