91 research outputs found
Serum and urine vitamin D metabolite analysis in early preeclampsia
Vitamin D-deficiency is common in pregnant women, and may contribute to adverse events in pregnancy such as preeclampsia (PET). To date, studies of vitamin D and PET have focused primarily on serum concentrations vitamin D, 25-hydroxyvitamin D3 (25(OH)D3) later in pregnancy. The aim here was to determine whether a more comprehensive analysis of vitamin D metabolites earlier in pregnancy could provide predictors of PET. Using samples from the SCOPE pregnancy cohort, multiple vitamin D metabolites were quantified by liquid chromatography-tandem mass spectrometry in paired serum and urine prior to the onset of PET symptoms. Samples from 50 women at pregnancy week 15 were analysed, with 25 (50%) developing PET by the end of the pregnancy and 25 continuing with uncomplicated pregnancy. Paired serum and urine from non-pregnant women (n=9) of reproductive age were also used as a control. Serum concentrations of 25(OH)D3, 25(OH)D2, 1,25(OH)2D3, 24,25(OH)2D3, and 3-epi-25(OH)D3 were measured and showed no significant difference between women with uncomplicated pregnancies and those developing PET. As previously reported, serum 1,25(OH)2D3 was higher in all pregnant women (in the second trimester), but serum 25(OH)D2 was also higher compared to non-pregnant women. In urine, 25(OH)D3 and 24,25(OH)2D3 were quantifiable, with both metabolites demonstrating significantly lower (p<0.05) concentrations of both of these metabolites in those destined to develop PET. These data indicate that analysis of urinary metabolites provides an additional insight into vitamin D and the kidney, with lower urinary 25(OH)D3, and 24,25(OH)2D3 excretion being an early indicator of a predisposition towards developing PET.</p
Data comparing the separation and elution of vitamin D metabolites on an ultra performance supercritical fluid chromatography tandem-mass spectrometer (UPSFC-MS/MS) compared to liquid chromatography (LC) and data presenting approaches to UPSFC method optimization
The data presented is related to the research article “Analysis of multiple vitamin D metabolites by ultra performance supercritical fluid chromatography-tandem mass spectrometry (UPSFC-MS/MS)” (Jenkinson et al., 2018) [1]. This article will include data obtained from method development, optimization and analysis of multiple vitamin D metabolites on an ultra performance supercritical fluid chromatography tandem-mass spectrometry (UPSFC-MS/MS). This includes chromatograms from column screening to confirm the most suitable column for analyte separation. Additionally, further chromatograms and figures compare separation and analyte signal strength during the optimization of other UPSFC parameters. Mass spectra will demonstrate the optimization of MS conditions for the UPSFC-MS/MS method. Chromatogram data from UHPLC vitamin D analysis is also presented in order to compare the separation and elution of vitamin D metabolites using UPSFC and UHPLC. This data will highlight the outputs that aid in method development and identifying the separation technique suited for vitamin D quantitation. Keywords: Vitamin D, Method development, UPSFC-MS/MS, LC-MS/M
Serum and synovial fluid vitamin D metabolites and rheumatoid arthritis
Vitamin D-deficiency has been linked to inflammatory diseases including rheumatoid arthritis (RA). Studies to date have focused on the impact of serum 25-hydroxyvitamin D3 (25(OH)D3), an inactive form of vitamin D, on RA disease activity and progression. However, anti-inflammatory actions of vitamin D are likely to be mediated at sites of RA disease, namely the inflamed joint, and may involve other vitamin D metabolites notably the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). In the current study serum and synovial fluid samples from n = 20 patients with persistent RA and n = 7 patients with reactive arthritis (ReA) were analysed for multiple vitamin D metabolites. Serum data for RA and ReA patients were compared to healthy controls (HC). There was no significant difference between RA or ReA patients relative to HC for 25(OH)D3, 24,25(OH)2D3, 1,25(OH)2D3 or 25(OH)D2. However, 3-epi-25(OH)D3 was significantly lower in RA and ReA patients compared to HC (p < 0.05). All vitamin D metabolites, apart from 25(OH)D2, were lower in SF compared to serum, and SF 1,25(OH)2D3 was unquantifiable in 13/20 RA and 4/7 ReA samples. SF 25(OH)D3, 3-epi-25(OH)D3 and DBP correlated inversely with swollen joint score, and serum 25(OH)D2 and SF DBP correlated directly with C-reactive protein levels. These data indicate that serum 25(OH)D3 provides only limited insight into the role of vitamin D in RA. Alternative serum metabolites such as 3-epi-25(OH)2D3, and SF metabolites, notably lack of SF 1,25(OH)2D3, may be more closely linked to RA disease severity and progress
The Effect of an Acute Bout of Exercise on Circulating Vitamin D Metabolite Concentrations:A Randomised Crossover Study in Healthy Adults
The effect of acute exercise on circulating concentrations of vitamin D metabolites is unclear. To address this knowledge gap, we examined the effect of a bout of treadmill-based exercise versus rest on circulating concentrations of 25(OH)D3, 25(OH)D2, 3-epi-25(OH)D3, 24,25(OH)2D3, 1,25(OH)2D3, and vitamin D2 and D3 in healthy men and women. Thirty-three healthy adults (14 females, 41 (15) y, body mass index 26.2 (3.7) kg/m2, V̇ O2 MAX 36.2 (9.2) mL/kg/min; mean (SD)) completed two laboratory visits involving 60 minutes of moderate intensity treadmill exercise (60% V̇ O2 MAX) versus 60 minutes of seated rest, both in an overnight fasted-state, as part of a randomised crossover design. Venous blood samples were drawn at baseline, immediately (0-hour), 1-hour and 24 hours after the exercise- or restperiod. There was a significant time x trial interaction effects for total circulating 25(OH)D (p=0.0148), 25(OH)D3 (p=0.0127) and 1,25(OH)2D3 (p=0.0226). Immediately post-exercise, 25(OH)D, 25(OH)D3, and 1,25(OH)2D3 concentrations were significantly elevated compared to the control resting condition, and 1,25(OH)2D3 remained significantly elevated one hour later. Circulating albumin, DBP, calcium and PTH were elevated immediately post-exercise. Thus, an acute bout of moderate intensity exercise transiently increases concentrations of circulating 25(OH)D and 1,25(OH)2D3 compared to resting conditions.<br/
Automated development of an LC-MS/MS method for measuring multiple vitamin D metabolites using MUSCLE software
This study describes the application of Multi-platform Unbiased optimization of Spectrometry via Closed-Loop Experimentation (MUSCLE) software to automate the development of an LC-MS/MS method to measure multiple metabolites of vitamin D.</p
Lymphotoxin β receptor controls T cell progenitor entry to the thymus
The recruitment of lymphoid progenitors to the thymus is essential to sustain T cell production throughout life. Importantly, it also limits T lineage regeneration following bone marrow transplantation, and so contributes to the secondary immunodeficiency that is caused by delayed immune reconstitution. Despite this significance, the mechanisms that control thymus colonization are poorly understood. In this study, we show that in both the steady-state and after bone marrow transplant, lymphotoxin β receptor (LTβR) controls entry of T cell progenitors to the thymus. We show that this requirement maps to thymic stroma, further underlining the key importance of this TNFR superfamily member in regulation of thymic microenvironments. Importantly, analysis of the requirement for LTβR in relationship to known regulators of thymus seeding suggests that it acts independently of its regulation of thymus-homing chemokines. Rather, we show that LTβR differentially regulates intrathymic expression of adhesion molecules known to play a role in T cell progenitor entry to the thymus. Finally, Ab-mediated in vivo LTβR stimulation following bone marrow transplant enhances initial thymus recovery and boosts donor-derived T cell numbers, which correlates with increased adhesion molecule expression by thymic stroma. Collectively, we reveal a novel link between LTβR and thymic stromal cells in thymus colonization, and highlight its potential as an immunotherapeutic target to boost T cell reconstitution after transplantation
11-oxygenated C19 steroids are the predominant androgens in polycystic ovary syndrome
Abstract
Context:
Androgen excess is a defining feature of polycystic ovary syndrome (PCOS), but the exact origin of hyperandrogenemia remains a matter of debate. Recent studies have highlighted the importance of the 11-oxygenated C19 steroid pathway to androgen metabolism in humans. In this study, we analyzed the contribution of 11-oxygenated androgens to androgen excess in women with PCOS.
Methods:
One hundred fourteen women with PCOS and 49 healthy control subjects underwent measurement of serum androgens by liquid chromatography-tandem mass spectrometry. Twenty-four–hour urinary androgen excretion was analyzed by gas chromatography-mass spectrometry. Fasting plasma insulin and glucose were measured for homeostatic model assessment of insulin resistance. Baseline demographic data, including body mass index, were recorded.
Results:
As expected, serum concentrations of the classic androgens testosterone (P &lt; 0.001), androstenedione (P &lt; 0.001), and dehydroepiandrosterone (P &lt; 0.01) were significantly increased in PCOS. Mirroring this, serum 11-oxygenated androgens 11β-hydroxyandrostenedione, 11-ketoandrostenedione, 11β-hydroxytestosterone, and 11-ketotestosterone were significantly higher in PCOS than in control subjects, as was the urinary 11-oxygenated androgen metabolite 11β-hydroxyandrosterone. The proportionate contribution of 11-oxygenated to total serum androgens was significantly higher in patients with PCOS compared with control subjects [53.0% (interquartile range, 48.7 to 60.3) vs 44.0% (interquartile range, 32.9 to 54.9); P &lt; 0.0001]. Obese (n = 51) and nonobese (n = 63) patients with PCOS had significantly increased 11-oxygenated androgens. Serum 11β-hydroxyandrostenedione and 11-ketoandrostenedione correlated significantly with markers of insulin resistance.
Conclusions:
We show that 11-oxygenated androgens represent the majority of circulating androgens in women with PCOS, with close correlation to markers of metabolic risk.
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