To date, several sensitive methods, based on radiolabeled elements or sterically hindered fluorochrome groups, are usually employed to screen phospholipase A (PLA) activities. With the aim of developing a convenient, specific, sensitive, and continuous new ultraviolet (UV) spectrophotometric assay for PLA, we have synthesized a specific glycerophosphatidylcholine (PC) esterified at the sn-1 and sn-2 positions, with α-eleostearic acid (9Z, 11E, 13E-octadecatrienoic acid) purified from Aleurites fordii seed oil. The conjugated triene present in α-eleostearic acid constitutes an intrinsic chromophore and, consequently, confers the strong UV absorption properties of this free fatty acid as well as of the glycerophospholipids harboring it. This coated PC film cannot be desorbed by the various buffers used during PLA assays. Following the action of PLA at the oil-water interface, α-eleostearic acid is freed and desorbed from the film and then solubilized with β-cyclodextrin. The UV absorbance of the α-eleostearic acid is considerably enhanced due to the transformation from an adsorbed to a water-soluble state. The PLA activity can be measured continuously by recording the variations with time of the UV absorption spectra. The rate of lipolysis was monitored by measuring the increase of absorption at 272 nm, which was found to be linear with time and proportional to the amount of added PLA. This continuous high-throughput PLA assay could be used to screen new PLA and/or PLA inhibitors present in various biological samples.
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http://dx.doi.org/10.1021/ac502096v | DOI Listing |
Biomark Med
January 2025
The Nutristasis Unit, Synnovis, St. Thomas' Hospital, London, UK.
This case describes a patient with pancreatic exocrine insufficiency and persistently elevated serum vitamin B12 concentrations that were not due to supplementation or associated with hepatic or hematological pathology. Laboratory investigations suggested the presence of macro-B12 as the cause of this patient's raised serum vitamin B12. Macro-B12 is often formed when vitamin B12-vitamin binding proteins (transcobalamin and haptocorrin) complex with immunoglobulins.
View Article and Find Full Text PDFBackground/aims: Certain sociodemographic groups are routinely underrepresented in clinical trials, limiting generalisability. Here, we describe the extent to which enriched enrolment approaches yielded a diverse trial population enriched for older age in a randomised controlled trial of a blood-based multi-cancer early detection test (NCT05611632).
Methods: Participants aged 50-77 years were recruited from eight Cancer Alliance regions in England.
Front Biosci (Landmark Ed)
January 2025
Department of Biomedical Sciences, Grand Valley State University, Allendale, MI 49401, USA.
Background: Diabetes mellitus is associated with morphological and functional impairment of the heart primarily due to lipid toxicity caused by increased fatty acid metabolism. Extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) have been implicated in the metabolism of fatty acids in the liver and skeletal muscles. However, their role in the heart in diabetes remains unclear.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
January 2025
Department of Obstetrics and Gynecology, Zhongda Hospital, School of Medicine, Southeast University, 210000 Nanjing, Jiangsu, China.
Background: Pre-eclampsia (PE) is a gestational disorder that significantly endangers maternal and fetal health. Transfer ribonucleic acid (tRNA)-derived small RNAs (tsRNAs) are important in the progression and diagnosis of various diseases. However, their role in the development of PE is unclear.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
January 2025
Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Fujian Medical University, Fujian Provincial Key Laboratory of Stomatology, National Regional Medical Center, Binhai Campus of The First Affiliated Hospital, 350005 Fuzhou, Fujian, China.
Background: In this study, we prepared a porous gradient scaffold with hydroxyapatite microtubules (HAMT) and chitosan (CHS) and investigated osteogenesis induced by these scaffolds.
Methods: The arrangement of wax balls in the mold can control the size and distribution of the pores of the scaffold, and form an interconnected gradient pore structure. The scaffolds were systematically evaluated and for biocompatibility, biological activity, and regulatory mechanisms.
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