Microglia transform in response to changes in sensory or neural activity, such as sensory deprivation. However, little is known about how specific frequencies of neural activity, or brain rhythms, affect microglia and cytokine signaling. Using visual noninvasive flickering sensory stimulation (flicker) to induce electrical neural activity at 40 hertz, within the gamma band, and 20 hertz, within the beta band, we found that these brain rhythms differentially affect microglial morphology and cytokine expression in healthy animals. Flicker induced expression of certain cytokines independently of microglia, including interleukin-10 and macrophage colony-stimulating factor. We hypothesized that nuclear factor κB (NF-κB) plays a causal role in frequency-specific cytokine and microglial responses because this pathway is activated by synaptic activity and regulates cytokines. After flicker, phospho–NF-κB colabeled with neurons more than microglia. Inhibition of NF-κB signaling down-regulated flicker-induced cytokine expression and attenuated flicker-induced changes in microglial morphology. These results reveal a mechanism through which brain rhythms affect brain function by altering microglial morphology and cytokines via NF-κB.

The field of cardiac surgery continues to evolve significantly and one such example of advancement is aortic root replacement. In the setting of prior cardiac surgery, operative complexity increases due to adhesions, surgically-altered anatomy, and previously implanted prosthetic graft material. Device choice plays a significant role in balancing operative complexity with achieving simplicity and optimal clinical outcomes. This review explores the critical considerations necessary in performing redo aortic root surgery and the impact that device selection can have on the procedural complexity and clinical outcomes. This review was formulated by a systematic identification of published and unpublished laboratory and clinical studies evaluating these technologies. Redo aortic root surgery represents one of the most challenging procedures in cardiac surgery, and the choice of both surgical technique and prosthetic device used are critical factors which influence the clinical success of the operation and the long-term outcomes for patients. By understanding the unique challenges of root replacement in a reoperative setting and the characteristics of different prosthetic devices, a tailored approach must be employed toward the best possible outcomes.

Background/Objectives: Acute Kidney Injury (AKI) requiring continuous renal replacement therapy (CRRT) has historically been a contraindication for left ventricular assist device (LVAD) implantation. However, advancements in magnetically levitated (MagLev) LVADs warrant reevaluation. Methods: A retrospective review of adult LVAD recipients at a tertiary center (2009–2024) was performed. Patients were stratified by preoperative CRRT status and LVAD type. Baseline characteristics and perioperative morbidity, Kaplan–Meier survival estimates, restrictive mean survival time (RMST), and Cox proportional hazards models were assessed. Results: Among 312 MagLev LVAD recipients, 22 (7.1%) required preoperative CRRT. Compared to non-CRRT patients, the CRRT group had higher illness severity (INTERMACS 1 or 2: 95% vs. 71%, p = 0.019). Despite this, preoperative CRRT was not associated with worse mortality within the MagLev cohort at 30 days (9.1% vs. 7.9%), 1 year (18.2% vs. 17.9%), or 2 years (31.8% vs. 20.7%; p = 0.31). RMST at 1 year was also similar (305 vs. 311 days; p = 0.85). In contrast, patients on CRRT receiving non-MagLev devices had significantly worse outcomes, with 30-day, 1-year, and 2-year mortality rates of 57.1%, 71.4%, and 78.6%, respectively. RMST analysis showed a 170-day survival advantage at 1 year for MagLev vs. non-MagLev CRRT patients (p < 0.01). Conclusions: In this single-center cohort, preoperative CRRT was not associated with higher mortality among MagLev LVAD recipients and may challenge traditional contraindications against LVAD therapy. Further investigations using larger cohorts are necessary to further evaluate these findings and delineate patient subgroups that may derive the greatest clinical benefit.