Autoimmune hepatitis (AIH) is a distinct clinical entity with variable presentations and diverse clinical outcomes, characterized by autoimmune-mediated injury to the liver. The detection of autoantibodies and histological features consistent with autoimmune injury is crucial for diagnosing AIH. Early identification and treatment are essential to prevent progression to cirrhosis.
View Article and Find Full Text PDFAcquired methemoglobinemia (MetHb) is a rare but potentially life-threatening condition that has varied etiology, usually toxin- or drug-induced. We had five cases of acquired methemoglobinemia during six months. Their presentation varied from an asymptomatic state to respiratory distress.
View Article and Find Full Text PDFStudying nucleic acids often requires labeling. Many labeling approaches require covalent bonds between the nucleic acid and the label, which complicates experimental procedures. Noncovalent labeling avoids the need for highly specific reagents and reaction conditions, and the effort of purifying bioconjugates.
View Article and Find Full Text PDFPulsed electron paramagnetic resonance (EPR) experiments, among them most prominently pulsed electron-electron double resonance experiments (PELDOR/DEER), resolve the conformational dynamics of nucleic acids with high resolution. The wide application of these powerful experiments is limited by the synthetic complexity of some of the best-performing spin labels. The recently developed $\bf\acute{G}$ (G-spin) label, an isoindoline-nitroxide derivative of guanine, can be incorporated non-covalently into DNA and RNA duplexes via Watson-Crick base pairing in an abasic site.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
August 2018
A series of purine-based spin labels was prepared for noncovalent spin-labeling of abasic sites of duplex nucleic acids through hydrogen bonding to an orphan base on the opposing strand and π-stacking interactions with the flanking bases. Both 1,1,3,3-tetramethylisoindolin-2-yloxyl and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) were conjugated to either the C2- or C6-position of the purines, yielding nitroxide derivatives of guanine, adenine, or 2,6-diaminopurine. The isoindoline-derived spin labels showed extensive or full binding to abasic sites in RNA duplexes, whereas the TEMPO-derived spin labels showed limited binding.
View Article and Find Full Text PDFAn isoindoline-nitroxide derivative of guanine (Ǵ, "G-spin") was shown to bind specifically and effectively to abasic sites in duplex RNAs. Distance measurements on a Ǵ-labeled duplex RNA with PELDOR (DEER) showed a strong orientation dependence. Thus, Ǵ is a readily synthesized, orientation-selective spin label for "mix and measure" PELDOR experiments.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
November 2016
Adenine phosphoribosyltransferase (APRT) deficiency is a hereditary disorder that leads to excessive urinary excretion of 2,8-dihydroxyadenine (DHA), causing nephrolithiasis and chronic kidney disease. Treatment with allopurinol or febuxostat reduces DHA production and attenuates the renal manifestations. Assessment of DHA crystalluria by urine microscopy is used for therapeutic monitoring, but lacks sensitivity.
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