| 1. |
- Phillips, E., et al.
(författare)
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Compound specific isotope analysis in hydrogeology
- 2022
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Ingår i: Journal of Hydrology. - : Elsevier BV. - 0022-1694. ; 615
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Forskningsöversikt (refereegranskat)abstract
- Here, we review the contributions of Professor Barbara Sherwood Lollar to Compound Specific Isotope Analysis (CSIA) in contaminant hydrogeology and environmental chemistry. We first discuss the seminal work by Professor Sherwood Lollar's lab on establishing CSIA as a quantitative tool for contaminant (bio)transformation at contaminated groundwater sites. We describe the critical research by her lab in the development and validation of sample collection techniques, single- and multi-element CSIA, and isotope data evaluation for reliable interpretations. We highlight the contributions of Professor Sherwood Lollar's lab towards the development of best practices for the successful application of CSIA by industry to demonstrate the occurrence of (bio)transformation, identify (bio)transformation mechanisms, quantify the extent and rate of degradation and differentiate among potential contaminant sources. We then explore Professor Sherwood Lollar's applications of CSIA to hydrogeology of the deep subsurface and the fast widening of the field to new environments (e.g., sediments), contaminants (e.g., chlorofluorocarbons, pesticides), and systems (e.g., plant, enzymes).
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| 2. |
- Artemenko, Konstantin A, et al.
(författare)
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Mass-spectrometry-based characterization of oxidations in proteins
- 2015
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Ingår i: Free radical research. - : Informa UK Limited. - 1071-5762 .- 1029-2470. ; 49:5, s. 477-93
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Forskningsöversikt (refereegranskat)abstract
- Protein modifications such as oxidations have a strong impact on protein function and activity in various organisms. High-resolution mass spectrometric techniques in combination with various sample preparation methodologies allow for the in-detail characterization of protein structures and strongly contribute to a greater understanding of the impact of protein modifications in nature. This paper outlines the general workflows for the characterization of oxidation sites in proteins by mass spectrometry (MS). Different types of oxidations are taken into consideration; both qualitative and quantitative aspects of MS-based approaches are presented with respect to oxidized proteins. Both bottom-up and top-down MS approaches are described and evaluated; a wide range of the particular applications corresponding to these techniques is also presented. Furthermore, the common advantages and downsides of these techniques are assessed. The approaches for enrichment of low-abundance oxidized proteins are extensively presented for different cysteine oxidations and protein carbonylations. A short description about databases and bioinformatic software solutions for oxidative protein prediction, identification, and biological interpretation is also given in this review.
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| 3. |
- Kushnir, Mark M., et al.
(författare)
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Exploratory study of the association of steroid profiles in stimulated ovarian follicular fluid with outcomes of IVF treatment
- 2016
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Ingår i: Journal of Steroid Biochemistry and Molecular Biology. - : Elsevier BV. - 0960-0760 .- 1879-1220. ; 162, s. 126-133
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Forskningsöversikt (refereegranskat)abstract
- Steroid concentrations in stimulated follicular fluid (sFF) samples have been linked to the quality of oocytes used in IVF treatments. Most of the published studies focused on evaluating the association of the IVF outcomes with only a few of the steroids, measured by immunoassays (IA). We performed a treatment outcome, prospective cohort study using stimulated FF sampled from 14 infertile women undergoing IVF treatment; single oocyte was used per IVF cycle. Fourteen endogenous steroids were analyzed in 22 ovarian follicle aspirations, which corresponded to the embryos used in the IVF. Ten oocytes were associated with live birth (LB) and 12 with no pregnancy (NP). Steroids were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Differences in distribution of concentrations in association with the pregnancy outcome (LB or NP), and receiver operating characteristic (ROC) curves analysis were performed for the entire cohort and for within-women data. The predominant androgen and estrogen in stimulated sFF were androstenedione (A4) and estradiol (E2), respectively. Lower concentrations of pregnenolone (Pr), lower ratios of A4/ dehydroepiandrosterone (DHEA), testosterone (Te)/DHEA, and greater ratios of E2/Te, and estrone/A4 were observed in sFF samples associated with LB. Among the oocytes associated with NP, in four out of 12 samples total concentration of androgens was above the distribution of the concentrations in the oocytes corresponding to the LB group. Observations of the study indicated increased consumption of precursors and increased biosynthesis of estrogens in the follicles associated with LB. Our data suggest that potentially steroid profiles in sFF obtained during oocyte retrieval may serve as biomarkers for selection of the best embryo to transfer after IVF.
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| 4. |
- Kushnir, Mark M., et al.
(författare)
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Liquid chromatography tandem mass spectrometry for analysis of steroids in clinical laboratories
- 2011
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Ingår i: Clinical Biochemistry. - : Elsevier BV. - 0009-9120 .- 1873-2933. ; 44:1, s. 77-88
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Forskningsöversikt (refereegranskat)abstract
- Liquid chromatography tandem mass spectrometry is one of the most specific techniques available in clinical laboratories. In the past, immunoassays were the primary methodology for analysis of steroids in biological samples because they are rapid and easy to perform. However, these methods were shown to suffer from the lack of specificity for measuring many of the diagnostically important steroids. LC-MS/MS overcomes many of the limitations of immunoassays, enhances diagnostic utility of the testing, and expands diagnostic capabilities in endocrinology. In addition to the superior quality of the measurements, LC-MS/MS allows high throughput testing using small sample volume with minimal sample preparation, and frees the laboratory from dependence on suppliers of assay specific reagents. LC-MS/MS is being widely employed for routine measurement of steroids, and the methodology plays an important role in the standardization and harmonization of measurements among clinical laboratories.
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