Development of a quantification method based on isotopic variants of O-methyl isourea (OMIU) in conjunction with reversed-phase (RP) liquid chromatography (LC) electrospray mass spectrometry is described for determining the relative quantification of tau-related peptides Ac-VQIVXK-NH2. Extracted ion chromatograms of the mass spectrometric data derived from online microcapillary LC separation identifies the retention times of the isotopically derivatized peptides together with their ion abundances. Data-dependent MSMS analysis of both derivatized variants of the same peptide provides a complementary method for identification and resolution between isobaric species. In addition, with respect to offline LC MALDI a larger number of analogues are detected and formation of amyloid is also observed for the aspartic acid and histidine-containing peptides.
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http://dx.doi.org/10.1016/j.jasms.2006.09.015 | DOI Listing |
Int J Mol Sci
December 2024
School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, UK.
Fumonisins, a class of mycotoxins predominantly produced by species, represent a major threat to food safety and public health due to their widespread occurrence in staple crops including peanuts, wine, rice, sorghum, and mainly in maize and maize-based food and feed products. Although fumonisins occur in different groups, the fumonisin B series, particularly fumonisin B1 (FB1) and fumonisin B2 (FB2), are the most prevalent and toxic in this group of mycotoxins and are of public health significance due to the many debilitating human and animal diseases and mycotoxicosis they cause and their classification as by the International Agency for Research on Cancer (IARC) as a class 2B carcinogen (probable human carcinogen). This has made them one of the most regulated mycotoxins, with stringent regulatory limits on their levels in food and feeds destined for human and animal consumption, especially maize and maize-based products.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Laboratory of Preclinical and Translational Research, Centro di Riferimento Oncologico della Basilicata (IRCCS-CROB), Rionero in Vulture, 85028 Potenza, Italy.
Oxidative phosphorylation and glycolysis are the main ATP-generating pathways in cell metabolism. The balance between these two pathways is frequently altered to carry out cell-specific activities in response to stimuli involving activation, proliferation, or differentiation. Despite being a useful tool for researching metabolic profiles in real time in relatively small numbers of cancer cells, the main Agilent Seahorse XF Pro Analyzer (Agilent Technologies, Santa Clara, CA, USA) guideline is currently not fully detailed in the distinction between suspensions vs.
View Article and Find Full Text PDFPlants (Basel)
December 2024
National-Local Joint Engineering Laboratory of Citrus Breeding, Cultivation/Horticulture Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China.
The 'Cuimi' kumquat is a unique citrus cultivar known for its thin, crisp pulp and sweet, aromatic flavor. In addition to its use in fresh consumption and processing, this variety exhibits certain medicinal properties. This study aims to investigate the genetic diversity of the Huanglongbing (HLB) bacterium across different tissues of the 'Cuimi' kumquat, offering a theoretical basis for understanding the HLB epidemic in Dechang County, Sichuan.
View Article and Find Full Text PDFJ Chromatogr A
December 2024
Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China. Electronic address:
Multicomponent quantitative analysis (MCQA) is necessary for comprehensively characterizing the quality of complex samples, including medicines, foods. However, the limited supply of reference substances and the high costs associated with testing hinder the application of the MCQA using the external standard (ES) method. Here we propose a Molar Mass Coefficient (MMC) method for the quantification of multiple compounds with identical chromophore utilizing a single reference compound (SRC) by a UV detector.
View Article and Find Full Text PDFVet Immunol Immunopathol
December 2024
Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348, United States; Pennsylvania Equine Toxicology & Research Laboratory, West Chester, PA 19382, United States. Electronic address:
Interleukin 1 beta (IL-1β) and IL-1 receptor antagonist (IL-1RA) are both upregulated following traumatic injury. As IL-1RA blocks inflammatory signaling by IL-1β, overexpression of IL-1β relative to IL-1RA may drive inflammatory diseases. As such, determination of the relationship between IL-1β to IL-1RA expression levels in horses may provide insight into disease states or serve as a therapeutic readout of response to medical interventions.
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