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Importance Advances in Alzheimer disease (AD) have shifted research focus to earlier disease stages, necessitating more scalable approaches to identify cognitively unimpaired individuals with amyloid β (Aβ) pathology. Objective To assess the utility of plasma phosphorylated tau 217 (p-tau217) for classifying Aβ status in cognitively unimpaired individuals, both as a stand-alone test and in a 2-step approach where positive plasma results were confirmed using a second modality (Aβ positron emission tomography [PET] or cerebrospinal fluid [CSF]). Design, Setting, and Participants This cross-sectional cohort study used data collected between June 2009 and March 2024. We included 2916 cognitively unimpaired participants from 12 international independent observational cohorts in the US, Europe, Australia, and Canada with available plasma p-tau217 levels and CSF or PET Aβ biomarkers. Performance comparisons between mass spectrometry and immunoassay-based p-tau217 measurements were also performed (n = 964). Exposures Plasma p-tau217 levels measured by immunoassay. Main Outcome and Measures Aβ status, determined by CSF or Aβ PET biomarkers. Results Participants had a mean (SD) age of 66.9 (9.9) years; 971 (33.3%) were Aβ positive by either CSF or PET, 1667 (57.2%) were women, and 1108 (38.1%) carried at least 1 APOE ε4 allele. As a stand-alone test, plasma p-tau217 achieved a positive predictive value (PPV) of 79% (95% CI, 74-84) and an overall accuracy of 81% (95% CI, 80-82). In a 2-step workflow, the PPV and accuracy significantly increased to 91% (95% CI, 86-95). While this approach required screening of 677 individuals with plasma p-tau217 to identify 100 Aβ-positive individuals, compared to 536 participants when using PET alone, it reduced the need for PET testing to 124. Immunoassays demonstrated comparable PPVs to mass spectrometry (80% [95% CI, 74-86] vs 85% [95% CI, 81-90]; P = .12) but significantly lower overall accuracy (82% [95% CI, 79-84]% vs 88 [95% CI, 86-90]; P < .001) and true Aβ-positive detection rate (49% [95% CI, 43-55] vs 69% [95% CI, 64-75]; P < .001). Conclusions and Relevance The findings highlight the potential of plasma p-tau217 as a stand-alone test—or when used in a sequential 2-step approach alongside PET or CSF testing—as a cost-effective, scalable, and minimally burdensome strategy for identifying preclinical AD. Tailored screening workflows that incorporate p-tau217 can improve efficiency in participant selection for preclinical AD trials and, in the future, help guide access to disease-modifying treatments.

Background and importance Emergency airway management in the emergency department (ED) is a high-risk procedure associated with patient outcomes. First-attempt success is a widely recognized quality metric, as multiple attempts are associated with an increased risk of peri-intubation complications. In Brazil, where emergency medicine is a recently established specialty, many ED are staffed by physicians without formal emergency medicine training. The association between emergency medicine training and intubation outcomes in this setting has not been well characterized. Objective To assess the association of physician specialty with first-attempt success and immediate peri-intubation complications in Brazilian EDs. Design Secondary analysis of a multicenter, prospective cohort study from the Brazilian Airway Registry Cooperation. Setting and participants This study included adult patients who underwent tracheal intubation in EDs between March 2022 and April 2024. Patients were excluded if the intubation occurred outside the ED, during cardiopulmonary resuscitation, or for elective procedures. Intubations performed by medical students were also excluded. Physicians were categorized by specialty as emergency medicine or nonemergency medicine. Outcome measures and analysis The primary outcome was first-attempt success; secondary outcomes included peri-intubation complications (severe hypoxemia, hemodynamic instability, and cardiac arrest). Multivariable logistic regression was used to assess the association between physician specialty and outcomes. Main results Among 2582 patients, 1087 (42.1%) were intubated by emergency physicians and 1495 (57.9%) by other physicians (mainly internal medicine and surgery). Intubations by emergency physicians were associated with a higher rate of first-attempt success [80.4 vs. 70.9%, adjusted odds ratio [aOR]: 1.63, 95% confidence interval (CI): 1.34–1.97]. There was also a higher odds of intubations without major complications (aOR: 1.20, 95% CI: 1.01–1.42). Conclusion In this study, there was a higher rate of first-attempt success in intubations performed by board-certified emergency physicians compared with other physicians working in Brazilian EDs.

ABSTRACT Background Flap complications following maxillectomy, reconstruction, and adjuvant proton beam therapy (PBT) for primary maxillary and sinonasal malignancies are not well described. Methods This retrospective cohort study included consecutive patients treated between 2016 and 2023 from a single‐institutional database. Results Thirteen patients were identified with a median follow‐up of 26 months. No immediate post‐operative complications occurred, with a median time between surgery and PBT of 61 days. Nine patients (69.2%) had high‐risk postoperative pathology and required 66+ Gy(RBE), including five (38.5%) with gross disease receiving 70 Gy(RBE). Flap necrosis and fistulization occurred in three patients (23.1%) following PBT (median time from PBT to complication, 112 days). Higher flap mean and minimum dose, flap volume receiving at least 66 Gy[RBE], and minimum dose to 50% flap volume were associated with complications. Conclusions Careful patient selection and planning strategies should be considered to mitigate flap complication risk following adjuvant PBT for high‐risk post‐operative pathology.

Abstract Valvular heart disease (VHD) is emerging as the next major epidemic in cardiovascular care, driven by the ageing population. The advent of less invasive alternatives to surgery—namely, transcatheter therapies—has revolutionized patient management, while simultaneously introducing new layers of complexity. Artificial intelligence (AI) holds significant promise to transform the care of patients with VHD across all dimensions, including diagnosis, prognostication, disease progression, and therapeutic decision-making. In this review, we provide a comprehensive overview of the current evidence, and discuss the challenges, risks, and future directions associated with the integration of AI in the management of VHD.

Abstract Background Disruption of the blood–brain barrier (BBB) in high-grade brain tumors is characterized by contrast accumulation on diagnostic imaging. This window of opportunity study correlates contrast imaging features with the tumor distribution of BBB-permeable (levetiracetam) and -impermeable (cefazolin) drugs. Methods Patients with a clinical diagnosis of a high-grade brain tumor underwent MRI for surgical planning. Cefazolin and levetiracetam were administered prior to skin incision, and serial plasma and image-registered tumor samples were collected during the operation. Drug levels were measured by LC-MS/MS, tissue drug levels were corrected for residual blood, and tumor-to-plasma concentration ratios were calculated. Intraoperative microdialysis was performed in a subset of patients to measure the same two drugs. Results Tumor (n = 125) and plasma (n = 261) samples were available for analysis from 42 operative cases. Across all samples, the tumor-to-plasma ratio was significantly lower for cefazolin (marginal mean [MM]: 0.15, 95% CI: 0.11–0.19) as compared to levetiracetam (MM: 0.70, 95% CI: 0.64–0.75; P < .001). When compared between contrast-enhancing and non-enhancing regions, tumor-to-plasma ratios for cefazolin varied by 4.4-fold (0.27, 95% CI: 0.20–0.35 vs. 0.06, 95% CI: 0.04–0.08, respectively; P < .001), and varied for levetiracetam by 1.4-fold (0.88, 95% CI: 0.78–0.97 vs. 0.61, 95% CI: 0.55–0.66, respectively; P < .001). These results were confirmed with the intra-operative microdialysis and a population pharmacokinetic analysis. Conclusions This study demonstrates significant inter- and intra-tumoral heterogeneity in drug delivery for both levetiracetam and cefazolin within high-grade brain tumors that is not necessarily predicted by clinical MR imaging and may reflect tumor-induced changes in both perfusion and BBB integrity.

Chronic pain affects nearly 100 million adults in the U.S., yet few novel therapeutics have emerged in recent decades. P2X4 receptor (P2X4R), implicated in pain signaling, represents a promising target. We evaluated a humanized single-chain variable fragment (hscFv) targeting P2X4R for its ability to reduce ATP-induced currents and modulate excitability in human dorsal root ganglion (hDRG) neurons. Voltage-clamp recordings confirmed that human P2X4R (hP2X4R) hscFv significantly reduced ATP-evoked currents in HEK-293T cells expressing human P2X4, likely by relocalization of the receptor to the perinuclear region after hscFv treatment. Immunohistochemistry and transcriptomic analyses demonstrated widespread P2X4R ( P2RX4 ) expression across hDRG neuronal subtypes in both male and female donors. Current-clamp recordings revealed that hP2X4R hscFv selectively increased action potential (AP) threshold in multi-firing hDRG neurons, without affecting single-firing neurons. Spontaneous activity at rest and depolarizing spontaneous fluctuation (DSF) amplitude were also reduced. Analysis confirmed consistent effects of hP2X4R hscFv on excitability parameters. These findings suggest that hP2X4 hscFv exerts modest but targeted effects on human sensory neurons, supporting its potential as a novel therapeutic for chronic pain.