A simple and rapid micellar electrokinetic chromatography (MEKC) method with UV detection was developed for the simultaneous separation and determination of all-trans- and 13-cis-retinoic acids in rabbit serum by on-line sweeping concentration technique. The serum sample was simply deproteinized and centrifuged. Various parameters affecting sample enrichment and separation were systematically investigated. Under optimal conditions, the analytes could be well separated within 17min, and the relative standard deviations (RSD) of migration times and peak areas were less than 3.4%. Compared with the conventional MEKC injection method, the 18- and 19-fold improvements in sensitivity were achieved, respectively. The proposed method has been successfully applied to the determination of all-trans- and 13-cis-retinoic acids in serum samples from rabbits and could be feasible for the further pharmacokinetics study of all-trans-retinoic acid.
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http://dx.doi.org/10.1016/j.chroma.2007.02.022 | DOI Listing |
J Vis Exp
December 2024
Department of Ophthalmology and Visual Neurosciences, University of Minnesota;
G protein-coupled receptors (GPCRs) are a superfamily of transmembrane proteins that initiate signaling cascades through activation of its G protein upon association with its ligand. In all mammalian vision, rhodopsin is the GPCR responsible for the initiation of the phototransduction cascade. Within photoreceptors, rhodopsin is bound to its chromophore 11-cis-retinal and is activated through the light-sensitive isomerization of 11-cis-retinal to all-trans-retinal, which activates the transducin G protein, resulting in the phototransduction cascade.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemical Engineering, National Institute of Technology, Nara College, Yamatokoriyama, Nara 639-1080, Japan.
This study focuses on two types of phosphonium cation-based ionic liquids (P-ILs) with different alkyl chains: triethylalkylphosphonium (P222R) and tributylalkylphosphonium (P444R) cations. Broadband dielectric spectroscopy showed that the translational motion of the ions accelerated with an increasing number of alkyl chains by coupling with their rotational motion in both P-ILs. Raman spectroscopy revealed that P222R cations, despite dielectric similarities to P444R cations, can form all-trans conformations and cation-rich nanodomains because they have a relatively polar, short alkyl chain moiety with a central P atom and less-polar alkyl chains than those of P444R cations.
View Article and Find Full Text PDFTher Adv Hematol
January 2025
Department of Paediatrics, First Affiliated Hospital, Sun Yat-sen University, Zhongshan Er Road, No. 58, Guangzhou, Guangdong 510080, China.
Background: Treatment outcomes for acute promyelocytic leukemia (APL) have improved with all-trans-retinoic acid and arsenic trioxide, yet relapse remains a concern, especially in pediatric patients. The prognostic value of minimal residual disease (MRD) post-induction and the impact of arsenic levels during induction on MRD are not fully understood.
Objectives: To evaluate the relationship between post-induction MRD levels and relapse-free survival (RFS) in pediatric APL patients, and to investigate the correlation between blood arsenic concentration levels during induction therapy and MRD status.
Int J Mol Sci
December 2024
Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen 361102, China.
All--retinal (atRAL)-induced photoreceptor atrophy and retinal degeneration are hallmark features of dry age-related macular degeneration (AMD) and Stargardt disease type 1 (STGD1). The toxicity of atRAL is closely related to the generation of reactive oxygen species (ROS). Quercetin, a natural product, is known for its potent antioxidant properties; however, its effects in mitigating atRAL-mediated retinal damage remains unclear.
View Article and Find Full Text PDFCancers (Basel)
December 2024
Clinic of Hematology, University Clinical Center of Serbia, 11000 Belgrade, Serbia.
Background: Acute promyelocytic leukemia (APL) is frequently associated with disseminated intravascular coagulation (DIC), leading to potentially life-threatening bleeding. Compared to bleeding, thromboses are a less commonly encountered problem.
Objective: The objective of our study was to identify the incidence and predictive value of demographic data, clinical-laboratory parameters, and thrombosis risk assessment models (RAMs) for venous thromboembolism (VTE) in patients with APL.
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