4 research outputs found
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Stability of High‐Quality Warfarin Anticoagulation in a Community‐Based Atrial Fibrillation Cohort: The Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) Study
Background: Warfarin reduces ischemic stroke risk in atrial fibrillation (AF) but increases bleeding risk. Novel anticoagulants challenge warfarin as stroke‐preventive therapy for AF. They are available at fixed doses but are more costly. Warfarin anticoagulation at a time in therapeutic range (TTR) ≥70% is similarly as effective and safe as novel anticoagulants. It is unclear whether AF patients with TTR ≥70% will remain stably anticoagulated and avoid the need to switch to a novel anticoagulant. We assessed stability of warfarin anticoagulation in AF patients with an initial TTR ≥70%. Methods and Results: Within the community‐based Anticoagulation and Risk Factors in AF (ATRIA) cohort followed from 1996 to 2003, we identified 2841 new warfarin users who continued warfarin over 9 months. We excluded months 1 to 3 to achieve a stable dose. For the 987 patients with TTR ≥70% in an initial 6‐month period (TTR 1; months 4–9), we described the distribution of TTR 2 (months 10–15) and assessed multivariable correlates of persistent TTR ≥70%. Of patients with TTR 1 ≥70%, 57% persisted with TTR 2 ≥70% and 16% deteriorated to TTR 2 <50%. Only initial TTR 1 ≥90% (adjusted odds ratio 1.47, 95% CI 1.07–2.01) independently predicted TTR 2 ≥70%. Heart failure was moderately associated with marked deterioration (TTR 2 <50%); adjusted odds ratio 1.45, 95% CI 1.00–2.10. Conclusions: Nearly 60% of AF patients with high‐quality TTR1 on warfarin maintained TTR ≥70% over the next 6 months. A minority deteriorated to very poor TTR. Patient features did not strongly predict TTR in the second 6‐month period. Our analyses support watchful waiting for AF patients with initial high‐quality warfarin anticoagulation before considering alternative anticoagulants
GluA2 mRNA distribution and regulation by miR-124 in hippocampal neurons
AMPA-type glutamate receptors mediate fast, excitatory neurotransmission in the brain, and their concentrations at synapses are important determinants of synaptic strength. We investigated the post-transcriptional regulation of GluA2, the calcium-impermeable AMPA receptor subunit, by examining the subcellular distribution of its mRNA and evaluating its translational regulation by microRNA in cultured mouse hippocampal neurons. Using computational approaches, we identified a conserved microRNA-124 (miR-124) binding site in the 3'UTR of GluA2 and demonstrated that miR-124 regulated the translation of GluA2 mRNA reporters in a sequence-specific manner in luciferase assays. While we hypothesized that this regulation might occur in dendrites, our biochemical and fluorescent in situ hybridization (FISH) data indicate that GluA2 mRNA does not localize to dendrites or synapses of mouse hippocampal neurons. In contrast, we detected significant concentrations of miR-124 in dendrites. Overexpression of miR-124 in dissociated neurons results in a 30% knockdown of GluA2 protein, as measured by immunoblot and quantitative immunocytochemistry, without producing any changes in GluA2 mRNA concentrations. While total GluA2 concentrations are reduced, we did not detect any changes in the concentration of synaptic GluA2. We conclude from these results that miR-124 interacts with GluA2 mRNA in the cell body to downregulate translation. Our data support a model in which GluA2 is translated in the cell body and subsequently transported to neuronal dendrites and synapses, and suggest that synaptic GluA2 concentrations are modified primarily by regulated protein trafficking rather than by regulated local translation
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Transcutaneous retrobulbar amphotericin B for rhino-orbital-cerebral mucormycosis: a multi-center retrospective comparative study
PurposeTo assess whether transcutaneous retrobulbar amphotericin B injections (TRAMB) reduce exenteration rate without increasing mortality in rhino-orbital-cerebral mucormycosis (ROCM).MethodsIn this retrospective case-control study, 46 patients (51 eyes) with biopsy-proven ROCM were evaluated at 9 tertiary care institutions from 1998 to 2021. Patients were stratified by radiographic evidence of local orbital versus extensive involvement at presentation. Extensive involvement was defined by MRI or CT evidence of abnormal or loss of contrast enhancement of the orbital apex with or without cavernous sinus, bilateral orbital, or intracranial extension. Cases (+TRAMB) received TRAMB as adjunctive therapy while controls (-TRAMB) did not. Patient survival, globe survival, and vision/motility loss were compared between +TRAMB and -TRAMB groups. A generalized linear mixed effects model including demographic and clinical covariates was used to evaluate the impact of TRAMB on orbital exenteration and disease-specific mortality.ResultsAmong eyes with local orbital involvement, exenteration was significantly lower in the +TRAMB group (1/8) versus -TRAMB (8/14) (p = 0.04). No significant difference in mortality was observed between the ±TRAMB groups. Among eyes with extensive involvement, there was no significant difference in exenteration or mortality rates between the ±TRAMB groups. Across all eyes, the number of TRAMB injections correlated with a statistically significant decreased rate of exenteration (p = 0.048); there was no correlation with mortality.ConclusionsPatients with ROCM with local orbital involvement treated with adjunctive TRAMB demonstrated a lower exenteration rate and no increased risk of mortality. For extensive involvement, adjunctive TRAMB does not improve or worsen these outcomes
GluA2 mRNA distribution and regulation by miR-124 in hippocampal neurons
AMPA-type glutamate receptors mediate fast, excitatory neurotransmission in the brain, and their concentrations at synapses are important determinants of synaptic strength. We investigated the post-transcriptional regulation of GluA2, the calcium-impermeable AMPA receptor subunit, by examining the subcellular distribution of its mRNA and evaluating its translational regulation by microRNA in cultured mouse hippocampal neurons. Using computational approaches, we identified a conserved microRNA-124 (miR-124) binding site in the 3'UTR of GluA2 and demonstrated that miR-124 regulated the translation of GluA2 mRNA reporters in a sequence-specific manner in luciferase assays. While we hypothesized that this regulation might occur in dendrites, our biochemical and fluorescent in situ hybridization (FISH) data indicate that GluA2 mRNA does not localize to dendrites or synapses of mouse hippocampal neurons. In contrast, we detected significant concentrations of miR-124 in dendrites. Overexpression of miR-124 in dissociated neurons results in a 30% knockdown of GluA2 protein, as measured by immunoblot and quantitative immunocytochemistry, without producing any changes in GluA2 mRNA concentrations. While total GluA2 concentrations are reduced, we did not detect any changes in the concentration of synaptic GluA2. We conclude from these results that miR-124 interacts with GluA2 mRNA in the cell body to downregulate translation. Our data support a model in which GluA2 is translated in the cell body and subsequently transported to neuronal dendrites and synapses, and suggest that synaptic GluA2 concentrations are modified primarily by regulated protein trafficking rather than by regulated local translation