Determination, intercorrelation and intraindividual stability of five steroids in hair, saliva and urine among chinese college students.

Hair steroids and their ratios are believed to be reliable biomarkers reflecting the long-term exposure of circulating steroids. Hereinto, two underlying assumptions are that hair biomarkers have consistency with traditional biomarkers in saliva or urine, and good long-term intraindividual stability across a long time. However, these two assumptions have not been well verified for most of hair biomarkers except for hair cortisol.

Simultaneous determination of antiretroviral drugs in human hair with liquid chromatography-electrospray ionization-tandem mass spectrometry.

The determination of the concentrations of antiretroviral drugs in hair is believed to be an important means for the assessment of the long-term adherence to highly active antiretroviral therapy. At present, the combination of tenofovir, lamivudine and nevirapine is widely used in China. However, there was no research reporting simultaneous determination of the three drugs in hair.

Correlations of hair level with salivary level in cortisol and cortisone.

Aims: Contrary findings exist on the consistency between hair cortisol and salivary cortisol in assessing the basal activity of the hypothalamic-pituitary-adrenal (HPA) axis. The mismatches in temporal characteristic and the indices of hair and salivary cortisol might be potential reasons for the inconsistency. The aim of this study was to investigate the consistency between hair and salivary levels in cortisol and cortisone by directly examining the correlation between hair level and salivary level with different temporal characteristics (acute, short-term and long-term levels) and reflecting different HPA functions (basal level and reactivity level) in the well-matched time span.

Intraindividual stability of cortisol and cortisone and the ratio of cortisol to cortisone in saliva, urine and hair.

Background: Cortisol, cortisone and the ratio of cortisol to cortisone in saliva, urine and hair are acute, short-term and long-term biomarkers to reliably assess the activity of hypothalamic-pituitary-adrenal (HPA) axis and 11β-hydroxysteroid dehydrogenase (11β-HSD). One key issue is whether these biomarkers have intraindividual relative stability. Salivary, urinary and hair cortisol was proven to show considerable long-term intraindividual relative stability.

Simultaneous HPLC-APCI-MS/MS quantification of endogenous cannabinoids and glucocorticoids in hair.

Hair matrix could retrospectively record association of endogenous cannabinoids (e.g. 2-arachidonoyl glycerol, 2-AG and N-arachidonoyl-ethanolamine, AEA) and glucocorticoids (e.