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F. Botre' - One of the best experts on this subject based on the ideXlab platform.
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A fast liquid chromatographic/mass spectrometric screening method for the simultaneous detection of Synthetic Glucocorticoids, some stimulants, anti-oestrogen drugs and Synthetic anabolic steroids.
Rapid communications in mass spectrometry : RCM, 2006Co-Authors: Monica Mazzarino, F. Botre'Abstract:A fast liquid chromatographic/mass spectrometric (LC/MS/MS) screening method for the detection, in urine, of Synthetic Glucocorticoids, stimulants (formoterol, modafinil and mesocarb), anti-oestrogens (finasteride, exemestane, anastrozole, letrozole and formestane) and Synthetic anabolic steroids (stanozolol, gestrinone and tetrahydrogestrinone) is described. All these drugs (and/or their urinary metabolites) can be simultaneously extracted by a single liquid/liquid extraction step, at alkaline pH, after enzymatic hydrolysis with beta-glucuronidase, and assayed in 7 min by LC/MS/MS using electrospray ionization in positive ion mode and multiple reaction monitoring as the acquisition mode. All compounds show good reproducibility of both the retention times (CV%
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a fast liquid chromatographic mass spectrometric screening method for the simultaneous detection of Synthetic Glucocorticoids some stimulants anti oestrogen drugs and Synthetic anabolic steroids
Rapid Communications in Mass Spectrometry, 2006Co-Authors: Monica Mazzarino, F. Botre'Abstract:A fast liquid chromatographic/mass spectrometric (LC/MS/MS) screening method for the detection, in urine, of Synthetic Glucocorticoids, stimulants (formoterol, modafinil and mesocarb), anti-oestrogens (finasteride, exemestane, anastrozole, letrozole and formestane) and Synthetic anabolic steroids (stanozolol, gestrinone and tetrahydrogestrinone) is described. All these drugs (and/or their urinary metabolites) can be simultaneously extracted by a single liquid/liquid extraction step, at alkaline pH, after enzymatic hydrolysis with beta-glucuronidase, and assayed in 7 min by LC/MS/MS using electrospray ionization in positive ion mode and multiple reaction monitoring as the acquisition mode. All compounds show good reproducibility of both the retention times (CV% <2%) and the relative abundances (CV% <10%). The limits of detection for the anti-oestrogens, Glucocorticoids and steroids are in the range of 1-30 ng/mL, and for the stimulants are in the range of 100-200 ng/mL, thus satisfying the minimum required performance limits of the World Anti-Doping Agency.
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Effect of the systemic versus inhalatory administration of Synthetic Glucocorticoids on the urinary steroid profile as studied by gas chromatography–mass spectrometry
Analytica Chimica Acta, 2006Co-Authors: Monica Mazzarino, Francesca Rossi, Laura Giacomelli, F. Botre'Abstract:Abstract This paper presents a gas chromatography–mass spectrometry (GC–MS) study carried out on human urine to verify whether the administration of Glucocorticoids can affect the urinary steroid profile, and especially the levels of endogenous Glucocorticoids, androgens and their main metabolites. Betamethasone and beclomethasone, administered either systemically (per os or i.m.) or locally (by inhalation) have been studied. The determination of the urinary levels of endogenous Glucocorticoids and androgens was carried out by GC–MS in electron impact ionization mode. Data were evaluated taking into account the baseline individual variability, and compared with values obtained on a control group. Detectable differences were recorded in the steroids metabolites excretion profiles between men and women. The circadian variability of the steroid profile was the same for both sexes, showing a maximum during the morning hours. After systemic treatment with Synthetic Glucocorticoids, the relative urinary concentrations of corticosteroids, androgens and of their metabolites were significantly altered, recording a transient decrease of the concentration of cortisol and tetrahydrocortisol and a parallel, although less pronounced, increase of the concentration of testosterone, epitestosterone and related androgenic steroids; while no effects were recorded if the administration was by inhalation.
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Determination of Endogenous and Synthetic Glucocorticoids in Human Urine by Gas Chromatography – Mass Spectrometry Following Microwave Assisted Derivatization
'Elsevier BV', 2003Co-Authors: L. Amendola, F. Garribba, F. Botre'Abstract:Acomplete screening and confirmation analytical method for the direct determination of six endogenous (cortisol, cortisone, deoxycorticosterone, tetrahydrocortisol, tetrahydrocortisone, tetrahydro-S) and 17 Synthetic (amcinonide, betamethasone, desoximethasone, dexamethasone, fludrocortisone, flumethasone, flunisolide, flucinolone acetonide, flucinonide, fluprednisolone, flurandrenolide, fluorometholone, 6-methylprednisolone, prednisolone, prednisone, triamcinolone, triamcinolone acetonide) Glucocorticoids in human urine by gas chromatography with mass spectrometric detection (GC–MS) is presented. The analytical technique comprises a pre treatment procedure and the instrumental analysis of the trimethylsilyl (TMS) derivatives, performed by GC–MS (quadrupole) with electron impact (EI) ionization. The derivatization yields obtained by two different derivatizing mixtures, namely N-methyl N(trimethylsilyl)trifluoroacetamide (MTSFA):NH4I:dithioerythritol (DTE) 1000:2:4 (usually indicated as TMSiodine); and N-trimethylsilylimidazole (TMSim):N,O-bis(trimethylsilyl)acetamide (BSA):trimethylchlorosilane (TMCS) 3:3:2, both under direct thermal heating and with microwave (MW) irradiation, were evaluated, also as a function of the temperature, of the MWì power and of the incubation time. The highest yields of the derivatization process were obtained, for most of the compounds here considered, by a two-step procedure: a microwave-assisted derivatization stage (40 min in a microwave oven at 900Wemitted power), followed by a traditional heat transfer derivatization (1.5 h in a thermostated bath at 70 ◦C) with the derivatization mixture TMSim:BSA:TMCS 3:3:2. In these operating conditions, diagnostic EI–MS spectra of all considered Glucocorticoids were obtained. Limits of detection (LOD) of Synthetic Glucocorticoids in urine ranged from 3 to 25g/l. The effectiveness of the method for the determination of Glucocorticoids in urine was evaluated on spiked urine samples and on real samples obtained from patients under pharmacological treatment with Synthetic Glucocorticoids. Apart from the clinical monitoring of Glucocorticoids in urine, the method can be applied as a complete screening + confirmation analytical protocol in antidoping tests for the detection of illicit administration of Glucocorticoids by the athletes
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Determination of endogenous and Synthetic Glucocorticoids in human urine by gas chromatography-mass spectrometry following microwave-assisted derivatization
Analytica Chimica Acta, 2003Co-Authors: L. Amendola, F. Garribba, F. Botre'Abstract:Abstract A complete screening and confirmation analytical method for the direct determination of six endogenous (cortisol, cortisone, deoxycorticosterone, tetrahydrocortisol, tetrahydrocortisone, tetrahydro- S ) and 17 Synthetic (amcinonide, betamethasone, desoximethasone, dexamethasone, fludrocortisone, flumethasone, flunisolide, flucinolone acetonide, flucinonide, fluprednisolone, flurandrenolide, fluorometholone, 6-methylprednisolone, prednisolone, prednisone, triamcinolone, triamcinolone acetonide) Glucocorticoids in human urine by gas chromatography with mass spectrometric detection (GC–MS) is presented. The analytical technique comprises a pre-treatment procedure and the instrumental analysis of the trimethylsilyl (TMS) derivatives, performed by GC–MS (quadrupole) with electron impact (EI) ionization. The derivatization yields obtained by two different derivatizing mixtures, namely N -methyl- N (trimethylsilyl)trifluoroacetamide (MTSFA):NH 4 I:dithioerythritol (DTE) 1000:2:4 (usually indicated as TMSiodine); and N -trimethylsilylimidazole (TMSim): N , O -bis(trimethylsilyl)acetamide (BSA):trimethylchlorosilane (TMCS) 3:3:2, both under direct thermal heating and with microwave (MW) irradiation, were evaluated, also as a function of the temperature, of the MW power and of the incubation time. The highest yields of the derivatization process were obtained, for most of the compounds here considered, by a two-step procedure: a microwave-assisted derivatization stage (40 min in a microwave oven at 900 W emitted power), followed by a traditional heat transfer derivatization (1.5 h in a thermostated bath at 70 °C) with the derivatization mixture TMSim:BSA:TMCS 3:3:2. In these operating conditions, diagnostic EI–MS spectra of all considered Glucocorticoids were obtained. Limits of detection (LOD) of Synthetic Glucocorticoids in urine ranged from 3 to 25 μg/l. The effectiveness of the method for the determination of Glucocorticoids in urine was evaluated on spiked urine samples and on real samples obtained from patients under pharmacological treatment with Synthetic Glucocorticoids. Apart from the clinical monitoring of Glucocorticoids in urine, the method can be applied as a complete screening + confirmation analytical protocol in antidoping tests for the detection of illicit administration of Glucocorticoids by the athletes.
Monica Mazzarino - One of the best experts on this subject based on the ideXlab platform.
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A fast liquid chromatographic/mass spectrometric screening method for the simultaneous detection of Synthetic Glucocorticoids, some stimulants, anti-oestrogen drugs and Synthetic anabolic steroids.
Rapid communications in mass spectrometry : RCM, 2006Co-Authors: Monica Mazzarino, F. Botre'Abstract:A fast liquid chromatographic/mass spectrometric (LC/MS/MS) screening method for the detection, in urine, of Synthetic Glucocorticoids, stimulants (formoterol, modafinil and mesocarb), anti-oestrogens (finasteride, exemestane, anastrozole, letrozole and formestane) and Synthetic anabolic steroids (stanozolol, gestrinone and tetrahydrogestrinone) is described. All these drugs (and/or their urinary metabolites) can be simultaneously extracted by a single liquid/liquid extraction step, at alkaline pH, after enzymatic hydrolysis with beta-glucuronidase, and assayed in 7 min by LC/MS/MS using electrospray ionization in positive ion mode and multiple reaction monitoring as the acquisition mode. All compounds show good reproducibility of both the retention times (CV%
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a fast liquid chromatographic mass spectrometric screening method for the simultaneous detection of Synthetic Glucocorticoids some stimulants anti oestrogen drugs and Synthetic anabolic steroids
Rapid Communications in Mass Spectrometry, 2006Co-Authors: Monica Mazzarino, F. Botre'Abstract:A fast liquid chromatographic/mass spectrometric (LC/MS/MS) screening method for the detection, in urine, of Synthetic Glucocorticoids, stimulants (formoterol, modafinil and mesocarb), anti-oestrogens (finasteride, exemestane, anastrozole, letrozole and formestane) and Synthetic anabolic steroids (stanozolol, gestrinone and tetrahydrogestrinone) is described. All these drugs (and/or their urinary metabolites) can be simultaneously extracted by a single liquid/liquid extraction step, at alkaline pH, after enzymatic hydrolysis with beta-glucuronidase, and assayed in 7 min by LC/MS/MS using electrospray ionization in positive ion mode and multiple reaction monitoring as the acquisition mode. All compounds show good reproducibility of both the retention times (CV% <2%) and the relative abundances (CV% <10%). The limits of detection for the anti-oestrogens, Glucocorticoids and steroids are in the range of 1-30 ng/mL, and for the stimulants are in the range of 100-200 ng/mL, thus satisfying the minimum required performance limits of the World Anti-Doping Agency.
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Effect of the systemic versus inhalatory administration of Synthetic Glucocorticoids on the urinary steroid profile as studied by gas chromatography–mass spectrometry
Analytica Chimica Acta, 2006Co-Authors: Monica Mazzarino, Francesca Rossi, Laura Giacomelli, F. Botre'Abstract:Abstract This paper presents a gas chromatography–mass spectrometry (GC–MS) study carried out on human urine to verify whether the administration of Glucocorticoids can affect the urinary steroid profile, and especially the levels of endogenous Glucocorticoids, androgens and their main metabolites. Betamethasone and beclomethasone, administered either systemically (per os or i.m.) or locally (by inhalation) have been studied. The determination of the urinary levels of endogenous Glucocorticoids and androgens was carried out by GC–MS in electron impact ionization mode. Data were evaluated taking into account the baseline individual variability, and compared with values obtained on a control group. Detectable differences were recorded in the steroids metabolites excretion profiles between men and women. The circadian variability of the steroid profile was the same for both sexes, showing a maximum during the morning hours. After systemic treatment with Synthetic Glucocorticoids, the relative urinary concentrations of corticosteroids, androgens and of their metabolites were significantly altered, recording a transient decrease of the concentration of cortisol and tetrahydrocortisol and a parallel, although less pronounced, increase of the concentration of testosterone, epitestosterone and related androgenic steroids; while no effects were recorded if the administration was by inhalation.
Lynn Vanhaecke - One of the best experts on this subject based on the ideXlab platform.
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Development and validation of a high-resolution mass-spectrometry–based method to study the long-term stability of natural and Synthetic Glucocorticoids in faeces
Journal of Chromatography A, 2014Co-Authors: Nathalie De Clercq, Julie Vanden Bussche, Siska Croubels, Philippe Delahaut, Lynn VanhaeckeAbstract:Faecal glucocorticoid analysis is a powerful non-invasive tool for the study of the animal endocrine status and stress physiology, which is mainly carried out by immunoassays, characterised by some limitations. In this study, an ultra high-performance liquid chromatography coupled to high resolution Orbitrap mass spectrometry (U-HPLC-HRMS) method was developed to confirm the presence of Glucocorticoids in bovine faeces during a long-term stability study. Because of the complex nature of faeces, an appropriate extraction and purification procedure was developed. To this extent, a Plackett–Burman experimental design was successfully applied to determine the key conditions for optimal extraction of Glucocorticoids from faeces. The targeted analysis, including natural and Synthetic Glucocorticoids, was successfully validated according to CD 2002/657/EC. Decision limits and detection capabilities for prednisolone, prednisone, methylprednisolone and the metabolites 20α-dihydroprednisolone and 20β-dihydroprednisolone ranged, respectively, from 0.15 to 2.95 μg kg−1 and from 0.40 to 5.20 μg kg−1. Limits of detection and limits of quantification for the natural Glucocorticoids dihydrocortisone, cortisol and cortisone ranged, respectively, from 0.55 to 2.10 μg kg−1 and from 0.70 to 5.00 μg kg−1. The stability study of Glucocorticoids in faecal matrix demonstrated that lyophilising the faeces, storage at -80°C, and aerobic conditions were optimal for preservation and able to significantly (p < 0.05) limit degradation up to 10 weeks.
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Development and validation of a high-resolution mass-spectrometry-based method to study the long-term stability of natural and Synthetic Glucocorticoids in faeces.
Journal of chromatography. A, 2014Co-Authors: Nathalie De Clercq, Julie Vanden Bussche, Siska Croubels, Philippe Delahaut, Lynn VanhaeckeAbstract:Faecal glucocorticoid analysis is a powerful non-invasive tool for the study of the animal endocrine status and stress physiology, which is mainly carried out by immunoassays, characterised by some limitations. In this study, an ultra high-performance liquid chromatography coupled to high resolution Orbitrap mass spectrometry (U-HPLC-HRMS) method was developed to confirm the presence of Glucocorticoids in bovine faeces during a long-term stability study. Because of the complex nature of faeces, an appropriate extraction and purification procedure was developed. To this extent, a Plackett–Burman experimental design was successfully applied to determine the key conditions for optimal extraction of Glucocorticoids from faeces. The targeted analysis, including natural and Synthetic Glucocorticoids, was successfully validated according to CD 2002/657/EC. Decision limits and detection capabilities for prednisolone, prednisone, methylprednisolone and the metabolites 20α-dihydroprednisolone and 20β-dihydroprednisolone ranged, respectively, from 0.15 to 2.95 μg kg−1 and from 0.40 to 5.20 μg kg−1. Limits of detection and limits of quantification for the natural Glucocorticoids dihydrocortisone, cortisol and cortisone ranged, respectively, from 0.55 to 2.10 μg kg−1 and from 0.70 to 5.00 μg kg−1. The stability study of Glucocorticoids in faecal matrix demonstrated that lyophilising the faeces, storage at -80°C, and aerobic conditions were optimal for preservation and able to significantly (p < 0.05) limit degradation up to 10 weeks.
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A validated analytical method to study the long-term stability of natural and Synthetic Glucocorticoids in livestock urine using ultra-high performance liquid chromatography coupled to Orbitrap-high resolution mass spectrometry.
Journal of chromatography. A, 2013Co-Authors: Nathalie De Clercq, Siska Croubels, Philippe Delahaut, Vanden Bussche Julie, Lynn VanhaeckeAbstract:Abstract Due to their growth-promoting effects, the use of Synthetic Glucocorticoids is strictly regulated in the European Union (Council Directive 2003/74/EC). In the frame of the national control plans, which should ensure the absence of residues in food products of animal origin, in recent years, a higher frequency of prednisolone positive bovine urines has been observed. This has raised questions with respect to the stability of natural corticoids in the respective urine samples and their potential to be transformed into Synthetic analogs. In this study, a ultra high performance liquid chromatography–high resolution mass spectrometry (UHPLC–HRMS) methodology was developed to examine the stability of Glucocorticoids in bovine urine under various storage conditions (up to 20 weeks) and to define suitable conditions for sample handling and storage, using an Orbitrap Exactive™. To this end, an extraction procedure was optimized using a Plackett–Burman experimental design to determine the key conditions for optimal extraction of Glucocorticoids from urine. Next, the analytical method was successfully validated according to the guidelines of CD 2002/657/EC. Decision limits and detection capabilities for prednisolone, prednisone and methylprednisolone ranged, respectively, from 0.1 to 0.5 μg L −1 and from 0.3 to 0.8 μg L −1 . For the natural Glucocorticoids limits of detection and limits of quantification for dihydrocortisone, cortisol and cortisone ranged, respectively, from 0.1 to 0.2 μg L −1 and from 0.3 to 0.8 μg L −1 . The stability study demonstrated that filter-sterilization of urine, storage at −80 °C, and acidic conditions (pH 3) were optimal for preservation of Glucocorticoids in urine and able to significantly limit degradation up to 20 weeks.
Stephen G. Matthews - One of the best experts on this subject based on the ideXlab platform.
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DNA methylome signatures of prenatal exposure to Synthetic Glucocorticoids in hippocampus and peripheral whole blood of female guinea pigs in early life
Translational psychiatry, 2021Co-Authors: Aya Sasaki, Alisa Kostaki, Margaret E. Eng, Abigail H. Lee, Stephen G. MatthewsAbstract:Synthetic Glucocorticoids (sGC) are administered to women at risk of preterm delivery, approximately 10% of all pregnancies. In animal models, offspring exposed to elevated Glucocorticoids, either by administration of sGC or endogenous Glucocorticoids as a result of maternal stress, show increased risk of developing behavioral, endocrine, and metabolic dysregulation. DNA methylation may play a critical role in long-lasting programming of gene regulation underlying these phenotypes. However, peripheral tissues such as blood are often the only accessible source of DNA for epigenetic analyses in humans. Here, we examined the hypothesis that prenatal sGC administration alters DNA methylation signatures in guinea pig offspring hippocampus and whole blood. We compared these signatures across the two tissue types to assess epigenetic biomarkers of common molecular pathways affected by sGC exposure. Guinea pigs were treated with sGC or saline in late gestation. Genome-wide modifications of DNA methylation were analyzed at single nucleotide resolution using reduced representation bisulfite sequencing in juvenile female offspring. Results indicate that there are tissue-specific as well as common methylation signatures of prenatal sGC exposure. Over 90% of the common methylation signatures associated with sGC exposure showed the same directionality of change in methylation. Among differentially methylated genes, 134 were modified in both hippocampus and blood, of which 61 showed methylation changes at identical CpG sites. Gene pathway analyses indicated that prenatal sGC exposure alters the methylation status of gene clusters involved in brain development. These data indicate concordance across tissues of epigenetic programming in response to alterations in glucocorticoid signaling.
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A Single Course of Synthetic Glucocorticoids in Pregnant Guinea Pigs Programs Behavior and Stress Response in Two Generations of Offspring
Endocrinology, 2018Co-Authors: Vasilis G. Moisiadis, Alisa Kostaki, Alexandros Mouratidis, Stephen G. MatthewsAbstract:Treatment with a single course of Synthetic Glucocorticoids (sGCs) is the standard of care for pregnant women who are at risk for preterm delivery. Animal studies have demonstrated that multiple course sGCs can program altered hypothalamic-pituitary-adrenal (HPA) axis response to stress in first-generation (F1) and second-generation (F2) offspring. In this study, we sought to determine whether HPA axis activity and stress-associated behaviors (i.e., locomotor activity, attention) are altered after a single course of sGC in F1 and F2 female and male offspring. Pregnant guinea pigs [parental generation (F0)] received sGC (1 mg/kg) or saline on gestational days 50 and 51. HPA function and behavior were assessed in juvenile and adult F1 and F2 offspring of both sexes after maternal transmission. In F1, sGCs increased the HPA stress response in females but decreased responsiveness in males (P < 0.05). sGC exposure in F0 produced the opposite effects in F2 (P < 0.05). Reduced HPA responsiveness in F2 females was associated with reduced expression of proopiomelanocortin mRNA and increased expression of glucocorticoid receptor in the anterior pituitary (P < 0.05). Locomotor activity and prepulse inhibition were reduced by sGCs in adult F1 offspring. No behavioral changes were observed in F2 animals. These data indicate effects of antenatal treatment with a single course of sGC are present in F2 after maternal transmission. However, there are fewer effects on HPA activity and behavior in F1 and F2 offspring compared with treatment with multiple courses of sGCs.
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Transgenerational effects of prenatal Synthetic Glucocorticoids on hypothalamic-pituitary-adrenal function.
Endocrinology, 2012Co-Authors: Majid Iqbal, Vasilis G. Moisiadis, Alisa Kostaki, Stephen G. MatthewsAbstract:Approximately 10% of pregnant women are at risk of preterm delivery and receive Synthetic Glucocorticoids (sGC) to promote fetal lung development. Studies have indicated that prenatal sGC therapy modifies hypothalamic-pituitary-adrenal (HPA) function in first-generation (F1) offspring. The objective of this study was to determine whether differences in HPA function and behavior are evident in the subsequent (F2) generation. Pregnant guinea pigs (F0) received betamethasone (BETA; 1 mg/kg) or saline on gestational d 40/41, 50/51, and 60/61. F1 females were mated with control males to create F2 offspring. HPA function was assessed in juvenile and adult F2 offspring. Locomotor activity was assessed in juvenile offspring. Analysis of HPA-related gene expression was undertaken in adult hippocampi, hypothalami, and pituitaries. Locomotor activity was reduced in F2 BETA males (P < 0.05). F2 BETA offspring displayed blunted cortisol response to swim stress (P < 0.05). After dexamethasone challenge, F2 BETA males a...
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transgenerational effects of prenatal Synthetic Glucocorticoids on hypothalamic pituitary adrenal function
Endocrinology, 2012Co-Authors: Majid Iqbal, Vasilis G. Moisiadis, Alisa Kostaki, Stephen G. MatthewsAbstract:Approximately 10% of pregnant women are at risk of preterm delivery and receive Synthetic Glucocorticoids (sGC) to promote fetal lung development. Studies have indicated that prenatal sGC therapy modifies hypothalamic-pituitary-adrenal (HPA) function in first-generation (F(1)) offspring. The objective of this study was to determine whether differences in HPA function and behavior are evident in the subsequent (F(2)) generation. Pregnant guinea pigs (F(0)) received betamethasone (BETA; 1 mg/kg) or saline on gestational d 40/41, 50/51, and 60/61. F(1) females were mated with control males to create F(2) offspring. HPA function was assessed in juvenile and adult F(2) offspring. Locomotor activity was assessed in juvenile offspring. Analysis of HPA-related gene expression was undertaken in adult hippocampi, hypothalami, and pituitaries. Locomotor activity was reduced in F(2) BETA males (P < 0.05). F(2) BETA offspring displayed blunted cortisol response to swim stress (P < 0.05). After dexamethasone challenge, F(2) BETA males and females displayed increased and decreased negative feedback, respectively. F(2) BETA females had reduced pituitary levels of proopiomelanocortin (and adrenocorticotropic hormone), and corticotropin-releasing hormone receptor mRNA and protein (P < 0.05). F(2) BETA males displayed increased hippocampal glucocorticoid receptor (P < 0.001), whereas in BETA females, hippocampal glucocorticoid receptor and mineralocorticoid receptor mRNA were decreased (P < 0.05). In conclusion, prenatal BETA treatment affects HPA function and behavior in F(2) offspring. In F(2) BETA females, pituitary function appears to be primarily affected, whereas hippocampal glucocorticoid feedback systems appear altered in both F(2) BETA males and females. These data have clinical implication given the widespread use of repeat course glucocorticoid therapy in the management of preterm labour.
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Multidrug resistance phosphoglycoprotein (ABCB1) expression in the guinea pig placenta: developmental changes and regulation by betamethasone.
Canadian journal of physiology and pharmacology, 2009Co-Authors: Grazyna M. Kalabis, Sophie Petropoulos, William Gibb, Stephen G. MatthewsAbstract:Placental ABCB1 plays an important role in fetal protection against xenobiotics in the maternal circulation. Limited evidence indicates that Glucocorticoids regulate ABCB1 expression in other tissues. Since approximately 10% of pregnant women are treated with Synthetic Glucocorticoids for threatened preterm labour, the effects of Synthetic Glucocorticoids on placental ABCB1 are important. We hypothesized that placental levels of ABCB1 are reduced in late gestation in the guinea pig and that Synthetic Glucocorticoids downregulate ABCB1 production. There was a significant decrease in placental Abcb1 mRNA expression in late gestation. Treatment of guinea pigs with betamethasone (1 mg/kg) on gestational days 40/41 and 50/51 resulted in a significant decrease in placental Abcb1 mRNA and protein expression. No sex differences were observed. Understanding the regulation of ABCB1 function will facilitate the development of treatment strategies for human fetal protection against maternally derived endobiotics and ...
Nathalie De Clercq - One of the best experts on this subject based on the ideXlab platform.
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Development and validation of a high-resolution mass-spectrometry–based method to study the long-term stability of natural and Synthetic Glucocorticoids in faeces
Journal of Chromatography A, 2014Co-Authors: Nathalie De Clercq, Julie Vanden Bussche, Siska Croubels, Philippe Delahaut, Lynn VanhaeckeAbstract:Faecal glucocorticoid analysis is a powerful non-invasive tool for the study of the animal endocrine status and stress physiology, which is mainly carried out by immunoassays, characterised by some limitations. In this study, an ultra high-performance liquid chromatography coupled to high resolution Orbitrap mass spectrometry (U-HPLC-HRMS) method was developed to confirm the presence of Glucocorticoids in bovine faeces during a long-term stability study. Because of the complex nature of faeces, an appropriate extraction and purification procedure was developed. To this extent, a Plackett–Burman experimental design was successfully applied to determine the key conditions for optimal extraction of Glucocorticoids from faeces. The targeted analysis, including natural and Synthetic Glucocorticoids, was successfully validated according to CD 2002/657/EC. Decision limits and detection capabilities for prednisolone, prednisone, methylprednisolone and the metabolites 20α-dihydroprednisolone and 20β-dihydroprednisolone ranged, respectively, from 0.15 to 2.95 μg kg−1 and from 0.40 to 5.20 μg kg−1. Limits of detection and limits of quantification for the natural Glucocorticoids dihydrocortisone, cortisol and cortisone ranged, respectively, from 0.55 to 2.10 μg kg−1 and from 0.70 to 5.00 μg kg−1. The stability study of Glucocorticoids in faecal matrix demonstrated that lyophilising the faeces, storage at -80°C, and aerobic conditions were optimal for preservation and able to significantly (p < 0.05) limit degradation up to 10 weeks.
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Development and validation of a high-resolution mass-spectrometry-based method to study the long-term stability of natural and Synthetic Glucocorticoids in faeces.
Journal of chromatography. A, 2014Co-Authors: Nathalie De Clercq, Julie Vanden Bussche, Siska Croubels, Philippe Delahaut, Lynn VanhaeckeAbstract:Faecal glucocorticoid analysis is a powerful non-invasive tool for the study of the animal endocrine status and stress physiology, which is mainly carried out by immunoassays, characterised by some limitations. In this study, an ultra high-performance liquid chromatography coupled to high resolution Orbitrap mass spectrometry (U-HPLC-HRMS) method was developed to confirm the presence of Glucocorticoids in bovine faeces during a long-term stability study. Because of the complex nature of faeces, an appropriate extraction and purification procedure was developed. To this extent, a Plackett–Burman experimental design was successfully applied to determine the key conditions for optimal extraction of Glucocorticoids from faeces. The targeted analysis, including natural and Synthetic Glucocorticoids, was successfully validated according to CD 2002/657/EC. Decision limits and detection capabilities for prednisolone, prednisone, methylprednisolone and the metabolites 20α-dihydroprednisolone and 20β-dihydroprednisolone ranged, respectively, from 0.15 to 2.95 μg kg−1 and from 0.40 to 5.20 μg kg−1. Limits of detection and limits of quantification for the natural Glucocorticoids dihydrocortisone, cortisol and cortisone ranged, respectively, from 0.55 to 2.10 μg kg−1 and from 0.70 to 5.00 μg kg−1. The stability study of Glucocorticoids in faecal matrix demonstrated that lyophilising the faeces, storage at -80°C, and aerobic conditions were optimal for preservation and able to significantly (p < 0.05) limit degradation up to 10 weeks.
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A validated analytical method to study the long-term stability of natural and Synthetic Glucocorticoids in livestock urine using ultra-high performance liquid chromatography coupled to Orbitrap-high resolution mass spectrometry.
Journal of chromatography. A, 2013Co-Authors: Nathalie De Clercq, Siska Croubels, Philippe Delahaut, Vanden Bussche Julie, Lynn VanhaeckeAbstract:Abstract Due to their growth-promoting effects, the use of Synthetic Glucocorticoids is strictly regulated in the European Union (Council Directive 2003/74/EC). In the frame of the national control plans, which should ensure the absence of residues in food products of animal origin, in recent years, a higher frequency of prednisolone positive bovine urines has been observed. This has raised questions with respect to the stability of natural corticoids in the respective urine samples and their potential to be transformed into Synthetic analogs. In this study, a ultra high performance liquid chromatography–high resolution mass spectrometry (UHPLC–HRMS) methodology was developed to examine the stability of Glucocorticoids in bovine urine under various storage conditions (up to 20 weeks) and to define suitable conditions for sample handling and storage, using an Orbitrap Exactive™. To this end, an extraction procedure was optimized using a Plackett–Burman experimental design to determine the key conditions for optimal extraction of Glucocorticoids from urine. Next, the analytical method was successfully validated according to the guidelines of CD 2002/657/EC. Decision limits and detection capabilities for prednisolone, prednisone and methylprednisolone ranged, respectively, from 0.1 to 0.5 μg L −1 and from 0.3 to 0.8 μg L −1 . For the natural Glucocorticoids limits of detection and limits of quantification for dihydrocortisone, cortisol and cortisone ranged, respectively, from 0.1 to 0.2 μg L −1 and from 0.3 to 0.8 μg L −1 . The stability study demonstrated that filter-sterilization of urine, storage at −80 °C, and acidic conditions (pH 3) were optimal for preservation of Glucocorticoids in urine and able to significantly limit degradation up to 20 weeks.