A review of obesity, insulin resistance, and the role of exercise in breast cancer patients.

Breast cancer, the most common female malignancy in the world, has a strong association with obesity and insulin resistance. The importance of these risk factors goes up significantly in patients already affected by this cancer as they negatively affect the prognosis, recurrence rate, and survival by various mechanisms. The literature on the role of physical activity and aerobic exercise on modifying the above risks is debatable with data both for and against it.

Urine concentrations of ecgonine from specimens with low benzoylecgonine levels using a new ecgonine assay.

A new approach to detecting drug positives for cocaine in urine having benzoylecgonine concentrations below the Department of Defense (DoD) cutoffs was examined by measuring the concentrations of the metabolite ecgonine. The DoD cutoff concentrations for determining a positive for cocaine are 150 and 100 ng/mL for radioimmunoassay and gas chromatography-mass spectrometry, respectively. To facilitate this approach, a new assay was developed for ecgonine using only 1 mL urine.

Detection of a GC/MS artifact peak as methamphetamine.

Recently, certain laboratories reported the presence of methamphetamine in several negative urine specimens. We have demonstrated an artifact peak, by SIM GC/MS, in negative urine specimens, that frequently matches the retention time and identity ion ratio criteria for methamphetamine. This peak resulted from the presence of high levels of pseudoephedrine (PS) or ephedrine (EP) and was produced after derivatization with 4-carbethoxyhexafluorobutyryl chloride (CB), heptafluorobutyric anhydride (HFB), and N-trifluoroacetyl-l-prolyl chloride (TFAP).

Retrospective analysis of some L-methamphetamine/L-amphetamine urine data.

A limited analysis is presented of data accumulated over about three years for specimens containing either nonracemic L-methamphetamine/L-amphetamine or racemic mixtures of the D and L stereoisomers. 55 data points for both nonracemic L-methamphetamine and racemic mixtures show that it is possible to report a specimen containing L-methamphetamine positive for illegal D-methamphetamine based on current guidelines unless chiral assays are performed on selected methamphetamine positives. Generation of only 45 racemic specimens from chiral analysis of about 5,000 urine methamphetamine positives demonstrates the overwhelming prevalence of nonracemic illegal D-methamphetamine in Southern California.