ABSTRACT
BACKGROUND: Regarding the pathophysiology of renal infarction (RI), cardioembolic causes could have large proportion. However, there are notable variations in prevalence of atrial fibrillation (AF) among patients with RI across different studies, ranging from 17 to 65%. The primary objective of this study is to analyze the incidence of AF in patients with RI. METHODS: This nationwide retrospective cohort study enrolled 5200 patients with RI from the Korean National Institute of Health Services database spanning the years 2013 to 2019. The study accessed the AF incidence rate within 12 months in patients without a prior history of AF. Events occurring within 3 months of RI diagnosis were excluded to mitigate cases diagnosed during the initial screening or those with AF diagnoses that were potentially overlooked in the past. RESULTS: AF occurred in 19.1% of patients with RI over the entire period (median: 2.5 years, interquartile range 1.04-4.25 years). The majority of AF cases (16.1%) occured within the first year, resulting in an overall incidence rate of 7.0 per 100 person-years. Patients with newly developed AF were, on average, older than those who did not develop AF (64.1 vs. 57.3 years, P < 0.001). The independent predictors of AF were identified as age, male sex, higher body mass index, current smoking, ischemic heart disease, and heart failure. CONCLUSIONS: Physicians should consider the implementation of active rhythm monitoring for patients with RI to identify potential occurrence of subclinical AF, even if not initially diagnosed during the initial screening after RI diagnosis.
Subject(s)
Atrial Fibrillation , Registries , Humans , Atrial Fibrillation/epidemiology , Atrial Fibrillation/diagnosis , Atrial Fibrillation/complications , Male , Female , Incidence , Retrospective Studies , Middle Aged , Republic of Korea/epidemiology , Aged , Infarction/epidemiology , Infarction/diagnosis , National Health Programs/statistics & numerical data , Cohort Studies , Kidney Diseases/epidemiology , Kidney Diseases/diagnosis , AdultABSTRACT
We prepared methotrexate (MTX)-encapsulated polymeric nanoparticles using methoxy poly(ethylene glycol) (MPEG)-grafted chitosan (ChitoPEG) copolymer. MTX-encapsulated polymeric nanoparticles of ChitoPEG copolymer has around 50-300nm in particle size and showed spherical shape when observed by transmission electron microscope (TEM). In (1)H nuclear magnetic resonance (NMR) study, the specific peaks of MTX and chitosan as a drug carrying inner-core disappeared at D(2)O and only the specific peak of MPEG was observed, while specific peaks of MPEG, MTX, and chitosan appeared in DCl/D(2)O mixtures. These results indicated that MTX was complexed with chitosan and then core-shell type nanoparticles had formed in aqueous environment, i.e., MTX/chitosan complexes composed of inner-core and MPEG composed of outer-shell of the nanoparticles. Loading efficiency of MTX in the polymeric nanoparticles was 94% (w/w) of ChitoPEG-1, 91.1% (w/w) of ChitoPEG-2, 90.1% (w/w) of ChitoPEG-3 and 65.2% (w/w) of ChitoPEG-4, expectively. The higher the drug feeding ratio, the higher the drug content and the lower the loading efficiency. The higher the MPEG graft ratio in the copolymer, the lower the drug content and loading efficiency. Drug contents evaluated by (1)H NMR were the same as found by UV spectrophotometer.
Subject(s)
Chitosan/analogs & derivatives , Chitosan/chemistry , Methotrexate/administration & dosage , Nanoparticles/chemistry , Polyethylene Glycols/chemistry , Chitosan/chemical synthesis , Drug Carriers , Drug Delivery Systems , Methotrexate/chemistry , Microscopy, Electron, Transmission , Nuclear Magnetic Resonance, Biomolecular , Particle Size , Polyethylene Glycols/chemical synthesisABSTRACT
The object of this study was to test the solubility of a methoxy poly(ethylene glycol) (MPEG)-grafted chitosan copolymer in organic solvents and aqueous solution. Water-soluble chitosan with low molecular weight (LMWSC) was used in a PEG-graft copolymerization. The MPEG was conjugated to chitosan using 4-dicyclohexylcarbodimide (DCC), and N-hydroxysuccimide (NHS). Introduction of PEG was confirmed by (1)H and (13)C NMR spectroscopy and FT-IR spectroscopy. The degree of substitution (DS) of MPEG into chitosan was calculated from (1)H NMR data and also by estimating the molecular weight (MW) using gel permeation chromatography (GPC). The DS values obtained from (1)H NMR spectroscopy and GPC were similar, indicating that MPEG-grafted LMWSC was synthesized and properly characterized. Furthermore, the introduction of PEG into chitosan increases the solubility in aqueous solutions over a range of pH values (4.0-11.0) and organic solvents such as DMF, DMSO, ethanol, and acetone.
