Multi-matrix assay of cortisol, cortisone and corticosterone using a combined MEPS-HPLC procedure

A dual-system, machine-learning approach reveals how daily pubertal hormones relate to psychological well-being in everyday life

The two studies presented in this paper seek to resolve mixed findings in research linking activity of pubertal hormones to daily adolescent outcomes. In study 1 we used a series of Confirmatory Factor Analyses to compare the fit of one and two-factor models of seven steroid hormones (n = 994 participants, 8084 samples) of the HPA and HPG axes, using data from a field study (https://www.icpsr.umich.edu/web/ICPSR/studies/38180) collected over ten consecutive weekdays in a representative sample of teens starting high school. In study 2, we fit a Bayesian model to our large dataset to explore how hormone activity was related to outcomes that have been demonstrated to be linked to mental health and wellbeing (self-reports of daily affect and stress coping). Results reveal, first that a two-factor solution of adolescent hormones showed good fit to our data, and second, that HPG activity, rather than the more often examined HPA activity, was associated with improved daily affect ratios and stress coping. These findings suggest that field research, when it is combined with powerful statistical techniques, may help to improve our understanding of the relationship between adolescent hormones and daily measures of well-being.

[Research progress of microextraction by packed sorbent and its application in microvolume sample extraction]

Microextraction is a rapidly developing sample preparation technology in the field of analytical chemistry, which is seeing widespread application. Accurate sample preparation can not only save time but also improve the efficiency of analysis, determination, and data quality. At present, sample pretreatment methods must be rapid, allow for miniaturization, automation, and convenient online connection with analytical instruments. To meet the requirements of green analytical methods and improve the extraction efficiency, microextraction techniques have been introduced as suitable replacements to conventional sample preparation and extraction methods. Microextraction using a packed sorbent (MEPS) is a new type of sample preparation technology. The MEPS equipment was prepared using microsyringe with a volume of 50-500 μL, including MEPS syringes and MEPS adsorption beds (barrel insert and needle, BIN), which is essentially similar to a miniaturized solid phase extraction device. The BIN contains the adsorbent and is built into the syringe needle. A typical MEPS extraction procedure involves repeatedly pumping the sample solution in two directions (up and down) through the adsorbent multiple times in the MEPS syringe. The specific operation course of MEPS includes conditioning, loading, washing, elution, and introduction into the analysis instrument. The conditioning process is adopted to infiltrate the dry sorbent and remove bubbles between the filler particles. The adsorption process is accomplished by pulling the liquid plunger of the syringe so that the sample flows through the adsorbent in both directions multiple times. The washing process involves rinsing the sorbent to remove unwanted components after the analyte is retained. The elution process involves the use of an eluent to ensure that the sample flows through the adsorbent in both directions multiple times, so that elution can be realized by the pumping-pushing action. The target analyte is eluted with the eluent, which can be directly used for chromatographic analysis. However, when processing complex biological matrix samples by MEPS, pretreatment steps such as dilution of the sample and removal of proteins are commonly required. At present, the operation modes of the MEPS equipment are classified into three types: manual, semi-automated, and fully automated. This increase in the degree of automation is highly conducive to processing extremely low or extremely high sample volumes. Critical factors affecting the MEPS performance have been investigated in this study. The conditions for MEPS optimization are the operating process parameters, including sample flow rate, sample volume, number of sample extraction cycles, type and volume of the adsorbent, and elution solvents. It is also necessary to consider the effect of the sample matrix on the performance of MEPS. The MEPS sorbent should be cleaned by a solvent to eliminate carryover and reuse. The sorbent is a core aspect of MEPS. Several types of commercial and non-commercial sorbents have been used in MEPS. Commercial sorbents include silica-based sorbents such as unmodified silica (SIL), C2, C8, and C18. Unmodified silicon-based silica is a normal phase adsorption material, which is highly polar and can be used to retain polar analytes. C18, C8, and C2 materials are suitable for reversed-phase adsorption, while SCX, SAX, APS, and M1 (C8+SCX) adsorbents are suitable for the mixed-mode and ion-exchange modes. Noncommercial sorbents include molecularly imprinted materials, restricted-access molecularly imprinted materials, graphitized carbon, conductive polymer materials, modified silicon materials, and covalent-organic framework materials. The performance of MEPS has recently been illustrated by online with LC-MS and GC-MS assays for the analysis of biological matrices, environmental samples, and food samples. Pretreatment in MEPS protocols includes dilution, protein precipitation, and centrifugation in biological fluid matrices. Because of the small sample size, fast operation, etc., MEPS is expected to be more widely used in the analysis of bio-matrix samples. MEPS devices could also play an important role in field pretreatment and analysis.

Current methods for stress marker detection in saliva

•

Introduction of relevant biomarkers in stress conditions.

•

Reference ranges of biomarkers in normal conditions.

•

Saliva as easy-accessible specimen.

•

Review of analytical methods for biomarker determination in saliva.

•

Possibilities for design of point-of-care devices.

Stress and stress-related diseases are leading to drastic consequences in private and professional life. Therefore, the need for stress prevention strategies is of personal and economic interest. Especially during the recent period related to covid-19 outbreak and lock-down, an ongoing discussion of increasing stress etiology is reported. Biomarker analysis may help to assist diagnosis and classification of stress-related diseases and therefore support therapeutical decisions. Due to its non-invasive sampling, the analysis of saliva has become highly attractive compared to the detection methods in other specimen. This review article summarizes the status of research, innovative approaches, and trends. Scientific literature published since 2011 was excerpted with concentration on the detection of up to seven promising marker substances. Most often reported cortisol represents the currently best evaluated stress marker, while norepinephrine (noradrenaline) or its metabolite 3-methoxy-4-hydroxyphenylglycol is also a quite commonly considered stress marker. Other complementary stress marker candidates are testosterone, dehydroepiandrosterone (DHEA) and its sulfonated analogue DHEA-S, alpha-amylase, secretory immunoglobulin A, and chromogranin A. Several working groups are researching in the field of stress marker detection to develop reliable, fast, and affordable methods. Analytical methods reported mainly focused on immunological and electrochemical as well as chromatographic methods hyphenated to mass spectrometric detection to yield the required detection limits.

Storage stability of five steroids and in dried blood spots for newborn screening and retrospective diagnosis of congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a severe inherited disorder of cortisol biosynthesis that is potentially lethal or can seriously affect quality of life. For the first time, we aimed to assess the stability of 21-deoxycortisol (21Deox), 11-deoxycortisol (11Deox), 4-androstenedione (4AD), 17-hydroxyprogesterone (17OHP) and cortisol (Cort), diagnostic for CAH, in dried blood spots (DBSs) during a 1 year storage at different temperatures. Spiked DBS samples were stored at room temperature, 4 °C, -20 °C or -70 °C, respectively and analyzed in triplicates using liquid chromatography–tandem mass spectrometry at Weeks 0, 1, 2, 3 and 4, Month 6 and Year 1. Analyte levels within ±15% vs the baseline were considered stable. Our observations show that 21Deox, 4AD and 17OHP were not significantly changed for 1 year even at room temperature at either analyte levels. In contrast, Cort required storage at 4 °C, -20 °C or -70 °C for long-term stability, being significantly decreased at room temperature from Month 6 (p<0.01) in both the 30(60) nM and the 90(180) nM samples. 11Deox was significantly decreased at room temperature at Year 1 (p<0.01) and only in the 30(60) nM samples. Thus, all biomarkers were stable for up to 1 year at 4 °C, -20 °C or -70 °C and at least for 4 weeks at room temperature. These findings have implications for analyses of stored DBS samples in 2^nd-tier assays in newborn screening and for retrospective CAH studies.

Salivary lactate and 8-isoprostaglandin F2α as potential non-invasive biomarkers for monitoring heart failure: a pilot study

Heart failure (HF) is a cardiovascular disease affecting about 26 million people worldwide costing about $100 billons per year. HF activates several compensatory mechanisms and neurohormonal systems, so we hypothesized that the concomitant monitoring of a panel of potential biomarkers related to such conditions might help predicting HF evolution. Saliva analysis by point-of-care devices is expected to become an innovative and powerful monitoring approach since the chemical composition of saliva mirrors that of blood. The aims of this study were (i) to develop an innovative procedure combining MEPS with UHPLC-MS/MS for the simultaneous determination of 8-isoprostaglandin F_2α and cortisol in saliva and (ii) to monitor lactate, uric acid, TNF-α, cortisol, α-amylase and 8-isoprostaglandin F_2α concentrations in stimulated saliva samples collected from 44 HF patients during their hospitalisation due to acute HF. Limit of detection of 10 pg/mL, satisfactory recovery (95–110%), and good intra- and inter-day precisions (RSD ≤ 10%) were obtained for 8-isoprostaglandin F_2α and cortisol. Salivary lactate and 8-isoprostaglandin F_2α were strongly correlated with NT-proBNP. Most patients (about 70%) showed a significant decrease (a factor of 3 at least) of both lactate and 8-isoprostaglandin F_2α levels at discharge, suggesting a relationship between salivary levels and improved clinical conditions during hospitalization.

Microextraction approaches for bioanalytical applications: An overview

Biological samples are usually complex matrices due to the presence of proteins, salts and a variety of organic compounds with chemical properties similar to those of the target analytes. Therefore, sample preparation is often mandatory in order to isolate the analytes from troublesome matrices before instrumental analysis. Because the number of samples in drug development, doping analysis, forensic science, toxicological analysis, and preclinical and clinical assays is steadily increasing, novel high throughput sample preparation approaches are calling for. The key factors in this development are the miniaturization and the automation of the sample preparation approaches so as to cope with most of the twelve principles of green chemistry. In this review, recent trends in sample preparation and novel strategies will be discussed in detail with particular focus on sorptive and liquid-phase microextraction in bioanalysis. The actual applicability of selective sorbents is also considered. Additionally, the role of 3D printing in microextraction for bioanalytical methods will be pinpointed.

A sensitive chemiluminescence based immunoassay for the detection of cortisol and cortisone as stress biomarkers

An electrochemically based antibody immobilization was used to perform environmentally and clinically relevant immunoassays for stress hormones biomarkers (cortisol and cortisone) using chemiluminescence (CL) detection. To achieve CL detection, the ferrocene tag on the antibodies was first oxidised, and this then acted as a catalyst for the luminol and hydrogen peroxide CL reaction. The conditions were optimised and measurements were made with an incubation time of 30 min. Using this approach limits of detection were obtained of 0.47 pg ml−1and 0.34 pg ml−1alsoR20.9912 and 0.9902 for cortisol and cortisone respectively with a linear concentration from 0 to 50 ng ml−1. The method was then applied to Zebrafish whole body and artificial saliva samples. For the Zebrafish sample recoveries of 91.0% and 90.0% were obtained with samples spiked with cortisol and cortisone, for artificial saliva the recoveries were 92.59% and 90.73% respectively. Interference studies showed only minor effects on the measurement of the analyte. A comparison between this procedure and the standard enzyme-linked immunosorbent assay (ELISA) procedure gave approximately the sameR2values.

Salivary cortisol and cortisone in the clinical setting

PURPOSE OF REVIEW

A resurgence of interest in salivary biomarkers has generated evidence for their value in assessing adrenal function. The advantages of salivary measurements include only free hormone is detected, samples can be collected during normal daily routines and stress-induced cortisol release is less likely to occur than during venepuncture. We review the use of salivary biomarkers to diagnose and monitor patients for conditions of cortisol excess and deficiency and discuss the value of measuring salivary cortisone versus salivary cortisol.

RECENT FINDINGS

Developments in laboratory techniques have enabled the measurement of salivary hormones with a high level of sensitivity and specificity. In states of altered cortisol binding, salivary biomarkers are more accurate measures of adrenal reserve than serum cortisol. Salivary cortisone is a superior marker of serum cortisol compared with salivary cortisol, specifically when serum cortisol is low and during hydrocortisone therapy when contamination of saliva may result in misleading salivary cortisol concentrations.

SUMMARY

Salivary cortisol and cortisone can be used to assess cortisol excess, deficiency and hydrocortisone replacement, with salivary cortisone having the advantage of detection when serum cortisol levels are low and there is no interference from oral hydrocortisone.

Enzymatic intracrine regulation of white adipose tissue

Abdominal fat formation has become a permanent risk factor for metabolic syndrome and various cancers in one-third of the world's population of obese and even lean patients. Formation of abdominal fat involves additional mechanisms beyond an imbalance in energy intake and expenditure, which explains systemic obesity. In this review, we briefly summarized autonomous regulatory circuits that locally produce hormones from inactive precursors or nutrients for intra-/auto-/paracrine signaling in white adipose depots. Enzymatic pathways activating steroid and thyroid hormones in adipose depots were compared with enzymatic production of retinoic acid from vitamin A. We discussed the role of intracrine circuits in fat-depot functions and strategies to reduce abdominal adiposity through thermogenic adipocytes with interrupted generation of retinoic acid.

Development of microextraction by packed sorbent for toxicological analysis of tricyclic antidepressant drugs in human oral fluid

The aim of this study was to apply microextraction by packed sorbent (MEPS) to the isolation of six tricyclic antidepressants (TCADs): nordoxepin, doxepin, desipramine, nortriptyline, imipramine, and amitriptyline from human oral fluid. Samples were collected from healthy volunteers via free spillage from the oral cavity to disposable test tubes. A method of oral fluid sample pretreatment was developed and optimized in terms of suitability for MEPS extraction and removing of interfering agents (protein, food debris, or air bubbles). Moreover, it was short and simple to perform with limited sample consumption (150μL). Extracts were analysed by UHPLC-MS. The MEPS/UHPLC-MS method was validated at three concentration levels (2.00, 4.00 and 8.00ng/mL) of all analytes in the range 1.25-10.0ng/mL. The following parameters were determined: limit of detection, limit of quantification, precision, and accuracy. For all tested concentration levels, the intra- and inter-day repeatability did not exceeded 8.1% and 12.2%, respectively. Gained LOQ value, 0.50ng/mL, made the MEPS/UHPLC-MS method to be a useful tool in clinical and forensic laboratories, which was demonstrated on the basis of analysis of real samples.