Rates of operative intervention and in-hospital mortality following subarachnoid hemorrhage in patients with COVID-19.

OBJECTIVE: COVID-19 had massive effects on the healthcare system and multifactorial implications for the management of intensive care unit and cerebrovascular patients. This study aimed to assess the effect of COVID-19 on the outcomes of patients with aneurysmal subarachnoid hemorrhage (SAH). METHODS: The National Inpatient Sample (NIS) was used to identify patients with nontraumatic SAH (ICD-10 code I60.x). Patients with nonaneurysmal cerebrovascular malformations or traumatic intracranial injuries were excluded. Only patients managed from April to December 2020 were included in the study given the availability of an ICD-10 code for COVID-19. Data on sociodemographic factors, hospital characteristics, comorbidities, NIS SAH Severity Score (NIS-SSS), surgical treatment, and death were acquired. Multivariable analysis was used to assess predictors of both surgical intervention and in-hospital mortality. RESULTS: In total, 6984 patients met the study criteria, 359 (5.1%) of whom had COVID-19. Those with COVID-19 were more likely to be younger and male and had a higher All Patient Refined Diagnosis-Related Groups illness severity subclass, and NIS-SSS. Moreover, patients with COVID-19 were less likely to undergo surgery (10.0% vs 23.6%, OR 0.35, p < 0.0001) and had significantly higher mortality rates (48.2% vs 22.7%, p < 0.0001). When controlling for other variables, COVID-19 was an independent predictor of death (OR 1.67, p = 0.0002). Aneurysm surgery was performed in 1597 patients (317 open and 1280 endovascular procedures). There was no difference between the cohorts positive and negative for COVID-19 in terms of time to surgery or type of surgery. CONCLUSIONS: COVID-19 had significant impacts on patients with nontraumatic SAH. Specifically, patients with COVID-19 were significantly less likely to undergo surgery and had higher in-hospital mortality rates; however, for patients who did undergo procedural intervention, there was no significant difference in the type of intervention. Multiple factors, from medical acuity to healthcare system limitations, may contribute to these findings. Further retrospective research is needed to identify both specific causes of lower intervention rates and other potential nonaneurysmal causes of SAH in patients with COVID-19.

Identification of RBM46 as a novel APOBEC1 cofactor for C-to-U RNA-editing activity.

Cytidine (C) to Uridine (U) RNA editing is a post-transcription modification that is involved in diverse biological processes. APOBEC1 (A1) catalyzes the conversion of C-to-U in RNA, which is important in regulating cholesterol metabolism through its editing activity on ApoB mRNA. However, A1 requires a cofactor to form an "editosome" for RNA editing activity. A1CF and RBM47, both RNA-binding proteins, have been identified as cofactors that pair with A1 to form editosomes and edit ApoB mRNA and other cellular RNAs. SYNCRIP is another RNA-binding protein that has been reported as a potential regulator of A1, although it is not directly involved in A1 RNA editing activity. Here, we describe the identification and characterization of a novel cofactor, RBM46 (RNA-Binding-Motif-protein-46), that can facilitate A1 to perform C-to-U editing on ApoB mRNA. Additionally, using the low-error circular RNA sequencing technique, we identified novel cellular RNA targets for the A1/RBM46 editosome. Our findings provide further insight into the complex regulatory network of RNA editing and the potential new function of A1 with its cofactors.

Modified Roller Tube Method for Precisely Localized and Repetitive Intermittent Imaging During Long-term Culture of Brain Slices in an Enclosed System.

Cultured rodent brain slices are useful for studying the cellular and molecular behavior of neurons and glia in an environment that maintains many of their normal in vivo interactions. Slices obtained from a variety of transgenic mouse lines or use of viral vectors for expression of fluorescently tagged proteins or reporters in wild type brain slices allow for high-resolution imaging by fluorescence microscopy. Although several methods have been developed for imaging brain slices, combining slice culture with the ability to perform repetitive high-resolution imaging of specific cells in live slices over long time periods has posed problems. This is especially true when viral vectors are used for expression of exogenous proteins since this is best done in a closed system to protect users and prevent cross contamination. Simple modifications made to the roller tube brain slice culture method that allow for repetitive high-resolution imaging of slices over many weeks in an enclosed system are reported. Culturing slices on photoetched coverslips permits the use of fiducial marks to rapidly and precisely reposition the stage to image the identical field over time before and after different treatments. Examples are shown for the use of this method combined with specific neuronal staining and expression to observe changes in hippocampal slice architecture, viral-mediated neuronal expression of fluorescent proteins, and the development of cofilin pathology, which was previously observed in the hippocampus of Alzheimer's disease (AD) in response to slice treatment with oligomers of amyloid-ß (Aß) peptide.