Androgen levels during adjuvant endocrine therapy in postmenopausal breast cancer patients.

OBJECTIVE: To investigate plasma steroid hormone levels in postmenopausal breast cancer patients with and without adjuvant endocrine therapy and in healthy postmenopausal women. METHODS: Steroid hormone levels in postmenopausal breast cancer patients treated with aromatase inhibitors (n = 32) were compared with breast cancer patients treated with tamoxifen (n = 34), breast cancer patients without adjuvant endocrine therapy (n = 15), and healthy postmenopausal women (n = 56). Pregnenolone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, 11-deoxycortisol, cortisol, cortisone, dehydroepiandrosterone (DHEA), androstenedione, total testosterone, dihydrotestosterone, estrone and estradiol were measured using liquid chromatography-tandem mass spectrometry. Sex hormone binding globulin was measured by solid-phase chemiluminescent immunometric assays, and the free androgen index was calculated. RESULTS: Aromatase inhibitor users did not differ in dihydrotestosterone, total testosterone, androstenedione, DHEA, or free androgen index levels from healthy controls or untreated breast cancer patients. The highest total testosterone levels were found in tamoxifen-treated women, who had significantly higher plasma concentrations than both women treated with aromatase inhibitors and breast cancer patients without adjuvant treatment. Concentrations of cortisol and cortisone were significantly greater in aromatase inhibitor users as well as tamoxifen users, in comparison with healthy controls and untreated breast cancer patients. Aromatase inhibitor users had lower estrone and estradiol plasma concentrations than all other groups. CONCLUSION: Adjuvant treatment with aromatase inhibitors or tamoxifen was associated with increased cortisol and cortisone plasma concentrations as well as decreased estradiol concentrations. Androgen levels were elevated in tamoxifen-treated women but not in aromatase inhibitor users.

Diagnostic value of vestibular evoked myogenic potentials in cerebellar and lower-brainstem strokes.

BACKGROUND: Vestibular evoked myogenic potentials (VEMPs) provide assessment of vestibular function. They consist in picking up compound muscle action potentials in the sternocleidomastoid (SCM) muscles in response to auditory stimulation of the vestibulum. VEMP testing has found application mainly in peripheral vestibular disorders, whereas reports about VEMPs in central vestibular lesions are rather scarce. AIMS OF THE STUDY: Based on the physiological connections between the cerebellum and the vestibular nuclei, we investigated the influence on VEMPs of cerebellar and lower-brainstem strokes. We examined whether or not this method may be suitable as a clinical tool for the evaluation of the extent of cerebellar strokes. PATIENTS AND METHODS: Nineteen patients with cerebellar ischemic stroke and 15 patients with lower-brainstem ischemic stroke (11 in the pons, four in the medulla) were included. The latencies and amplitudes of P13 and N23 in both groups of patients were compared with those obtained in a control group of 53 normal individuals. RESULTS: VEMP responses were obtained in all patients and controls. At the group level, mean peak latencies and amplitudes, and the number of subjects with significantly deviant values did not differ between patients and controls. There were no latency or amplitude differences ipsilaterally or contralaterally to the lesion. At the individual level, there was no correlation between laterality of lesion and that of P13 or N23 abnormalities in patients with cerebellar strokes; however, there were two patients (one pontine, one medullar stroke) who presented P13 and N23 latency abnormalities ipsilaterally to the lesion. CONCLUSION: Cerebellar strokes do not influence VEMPs. Moreover, despite previous reports, we were unable to find at a group level any statistically significant VEMP changes in patients with lower-brainstem strokes as compared with controls. Therefore, VEMPs do not appear a suitable tool for assessment of brainstem integrity in patients with posterior fossa strokes. However, they could constitute a sensitive method for documentation of involvement of the central vestibular pathways in patients with brainstem stroke.

Nitrite adulteration of workplace urine drug-testing specimens. I. Sources and associated concentrations of nitrite in urine and distinction between natural sources and adulteration.

The active ingredient in the commercial workplace urine drug-testing adulterant, Klear, was previously determined to be nitrite ion. Nitrite adulteration compromises the confirmation of some drugs, notably the marijuana metabolite. A previously reported bisulfite step overcomes some nitrite adulteration, but it cannot do so in every case, which leaves the laboratory to report the specimen as not suitable for testing. Unlike many other adulterants, nitrite is found in normal urine at low concentrations. In order to defend a report of nitrite adulteration, it is necessary to provide evidence that the amount of nitrite in a workplace urine specimen could not arise by normal means. The objectives of this study were to identify all sources of nitrite in urine and the range of concentrations associated with these sources and to determine if nitrite adulteration can be supported based upon a quantitative result. The scientific literature was reviewed for internal and external sources of nitrite and their concentration ranges and are reported. The following specimens were obtained and nitrite concentrations measured by a spectrophotometric method: clinical specimens nitrite positive by test strip (< 15 micrograms/mL); specimens culture positive for nitrate-reducing microorganisms (< 36 micrograms/mL); specimens from patients on medications that may metabolize to nitrite (< 6 micrograms/mL); and drug-test specimens, both negative (< 130 micrograms/mL) and others that appeared to be adulterated with nitrite (range 1910-12,200 micrograms/mL, mean 5910). The literature and the nitrite measurements of this study indicate a substantial difference between concentrations from natural sources compared with adulteration. A quantitative measurement of nitrite by a well-structured assay can provide scientifically valid and forensically defensible proof of adulteration with a nitrite-containing substance.