Levonorgestrel (LNG), a synthetic progestin widely used in emergency contraception, is increasingly taken frequently and often without medical supervision. With rising concerns that repeated exposure Show more
Levonorgestrel (LNG), a synthetic progestin widely used in emergency contraception, is increasingly taken frequently and often without medical supervision. With rising concerns that repeated exposure to such hormones may adversely affect brain function, this study investigated whether chronic LNG administration impairs cognitive-like behavior and alters key neurochemical pathways in female Wistar rats. Experimental rats were assigned to three groups receiving normal saline (control) or LNG (4 or 8 µg/kg) every alternate day for 60 days. Cognitive performance was assessed using the Morris water maze (MWM) and novel object recognition (NOR) tests. Hippocampal tissues were subsequently analyzed for glutamatergic markers and downstream signaling molecules involved in learning and memory. Chronic LNG exposure (4 and 8 µg/kg) impaired both spatial and non-spatial memory, evidenced by prolonged escape latency and reduced path efficiency in the MWM, along with a decreased discrimination index in the NOR test. Neurochemically, LNG significantly reduced hippocampal levels of glutamate, N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor ligands, protein kinase A (PKA), calcium/calmodulin-dependent kinase II (CaMKII), and brain-derived neurotrophic factor (BDNF), with the 8 µg/kg dose exerting more pronounced effects. Repeated LNG administration leads to notable cognitive deficits, likely mediated by impairments in glutamatergic signaling and downstream molecular pathways essential for synaptic plasticity. These findings underscore potential neurocognitive risks associated with prolonged LNG exposure. Show less
Inherited primary arrhythmia syndromes and arrhythmogenic cardiomyopathies can lead to sudden cardiac arrest in otherwise healthy individuals. The burden and expression of these diseases in a real-wor Show more
Inherited primary arrhythmia syndromes and arrhythmogenic cardiomyopathies can lead to sudden cardiac arrest in otherwise healthy individuals. The burden and expression of these diseases in a real-world, well-phenotyped cardiovascular population is not well understood. Whole exome sequencing was performed on 8574 individuals from the CATHGEN cohort (Catheterization Genetics). Variants in 55 arrhythmia-related genes (associated with 8 disorders) were identified and assessed for pathogenicity based on American College of Genetics and Genomics/Association for Molecular Pathology criteria. Individuals carrying pathogenic/likely pathogenic (P/LP) variants were grouped by arrhythmogenic disorder and matched 1:5 to noncarrier controls based on age, sex, and genetic ancestry. Long-term phenotypic data were annotated through deep electronic health record review. Fifty-eight P/LP variants were found in 79 individuals in 12 genes associated with 5 arrhythmogenic disorders (arrhythmogenic right ventricular cardiomyopathy, Brugada syndrome, hypertrophic cardiomyopathy, In a real-world cardiovascular cohort, P/LP variants in arrhythmia-related genes were relatively common (1:108 prevalence) and most penetrant in Show less