Variability in plasma concentrations of methylprednisolone 6 days after intrasynovial injection of methylprednisolone acetate in racing horses: A field study.

Background: Methylprednisolone (MP) acetate is a commonly used corticosteroid for suppression of inflammation in synovial structures in horses. Its use is often regulated in equine sports by plasma MP concentrations.

Objectives: To describe variability in MP plasma concentrations after MP acetate injection in different synovial structures and with co-administration with hyaluronic acid (HA).

Does the school performance variable used in the International Health Behavior in School-Aged Children (HBSC) Study reflect students' school grades?

Background: Given the pressure that educators and policy makers are under to achieve academic standards for students, understanding the relationship of academic success to various aspects of health is important. The international Health Behavior in School-Aged Children (HBSC) questionnaire, being used in 41 countries with different school and grading systems, has contained an item assessing perceived school performance (PSP) since 1986. Whereas the test-retest reliability of this item has been reported previously, we determined its convergent and discriminant validity.

Reliability, construct and criterion validity of the KIDSCREEN-10 score: a short measure for children and adolescents' well-being and health-related quality of life.

Background: To assess the criterion and construct validity of the KIDSCREEN-10 well-being and health-related quality of life (HRQoL) score, a short version of the KIDSCREEN-52 and KIDSCREEN-27 instruments.

Methods: The child self-report and parent report versions of the KIDSCREEN-10 were tested in a sample of 22,830 European children and adolescents aged 8-18 and their parents (n = 16,237). Correlation with the KIDSCREEN-52 and associations with other generic HRQoL measures, physical and mental health, and socioeconomic status were examined.

The limit of detection in generalized least-squares calibrations: an example using alprazolam liquid chromatography-tandem mass spectrometry data.

Limit of detection (LOD) values provide useful indicators for the suitability of an analytical method for samples with low analyte levels. An LOD value can also be used to estimate the false positive probability (p(x >or= LOD)) of a result for a sample with no analyte present, as well as the false negative probability (p(x View Article and Find Full Text PDF

Comparison of ordinary, weighted, and generalized least-squares straight-line calibrations for LC-MS-MS, GC-MS, HPLC, GC, and enzymatic assay.

The impact of experimental errors in one or both variables on the use of linear least-squares was investigated for method calibrations (response = intercept plus slope times concentration, or equivalently, Y = a(1) + a(2)X ) frequently used in analytical toxicology. In principle, the most reliable calibrations should consider errors from all sources, but consideration of concentration (X) uncertainties has not been common due to complex fitting algorithm requirements. Data were obtained for liquid chromatography-tandem mass spectrometry, gas chromatography-mass spectrometry, high-performance liquid chromatography, gas chromatography, and enzymatic assay.