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A bstract Alzheimer’s disease (AD) presents with substantial clinical and anatomical heterogeneity, including both typical amnestic and atypical variants such as posterior cortical atrophy and logopenic primary progressive aphasia. Although neurofibrillary tangle (NFT) burden is a defining pathological feature of AD, its regional distribution varies across clinical phenotypes, suggesting that selective neuronal vulnerability may shape disease presentation. However, the cellular and molecular determinants underlying this vulnerability remain incompletely understood. Here, we profiled single-nucleus transcriptomes across multiple brain regions, including hippocampal (CA1) and neocortical (superior temporal gyrus and occipital cortex) regions, from individuals with typical and atypical AD and healthy controls. Integrative analysis identified major cell classes and resolved diverse excitatory and inhibitory neuronal subpopulations that were reproducibly observed across regions and individuals. Using quasi-binomial regression models to assess compositional changes, we quantified subtype-specific vulnerability associated with AD pathology. We identified a distinct excitatory neuronal subpopulation characterized by NRGN and BEX1 expression, which showed reproducible depletion across multiple regions, with the strongest evidence in amnestic AD and in neocortical regions in lvPPA. This vulnerable population showed concordance with previously reported AD-associated excitatory neuron signatures, supporting a conserved transcriptional program of susceptibility. Genes enriched in this population were associated with chemical synaptic transmission and regulation of synaptic plasticity and formed interconnected networks in protein-protein interaction analyses. These findings suggest that intrinsic properties related to synaptic function may predispose specific neuronal populations to degeneration in AD. Together, our results define a conserved, transcriptionally distinct excitatory neuron subpopulation that is selectively vulnerable across AD phenotypes and brain regions. This work provides a framework for linking regional pathology to cell-type-specific susceptibility and highlights synaptic regulatory pathways as potential contributors to neuronal degeneration in Alzheimer’s disease.

ABSTRACT BACKGROUND Increasing evidence suggests that accurate prediction of Alzheimer’s disease (AD) symptom onset requires more than amyloid- and tau-centric biomarkers such as cerebrospinal fluid (CSF) Aβ42/40, total tau and p-tau181 and plasma p-tau217. Autosomal dominant AD (ADAD), caused by pathogenic PSEN1, PSEN2 and APP mutations with predictable age at symptom onset, presents a unique opportunity to characterize the chronological changes in proteins beyond amyloid and tau and clarify them as early biomarkers of disease onset or as biomarkers related to disease staging and progression monitoring. METHODS We measured 972 CSF samples corresponding to 484 participants of the Dominantly Inherited Alzheimer Disease Network (DIAN) using the NULISASeq 120 CNS Disease Panel. We first benchmarked the technology against gold-standard measurements followed by the identification of proteins that were differentially abundant in relation to mutation status and symptomatology. Next, we determined the chronological emergence of protein changes in relation to the estimated years to onset (EYO). Finally, we assessed whether specific protein measures improved the prediction of EYO in the ADAD. FINDINGS NULISA measurements were comparable to those previously published. We demonstrated that known early alterations in CSF amyloid and tau were followed by inflammatory and neurodegenerative responses suggesting that clinical manifestation of AD happens before the inflammatory processes is fully developed. Finally, we found a multi-protein composite approach for predicting EYO that outperformed single biomarker values. INTERPRETATION Our results suggest that the main CSF proteomic landscape changes in ADAD are due to the presence of a pathogenic mutation and occur prior to symptom onset. Improved performance of multi-protein composite to predict EYO compared to single biomarker values highlights the added value of multiplex proteomic signatures for biomarker panel development. FUNDING National Institute on Aging, Alzheimer’s Association, German Center for Neurodegenerative Diseases, Raul Carrea Institute for Neurological Research, Japan Agency for Medical Research and Development, Ministry of Health & Welfare and Ministry of Science and ICT, Republic of Korea, Spanish Institute of Health Carlos III.

Abstract Background DDX3X- syndrome is a rare neurodevelopmental disorder characterized by varying degrees of intellectual disability, predominantly affecting females. We present an institutional cohort supplemented by a systematic literature review, expanding the cardiovascular phenotype of DDX3X- syndrome. Methods We conducted a retrospective chart review of patients diagnosed with DDX3X -syndrome at Mayo Clinic. Additionally, we performed a systematic literature review to identify studies reporting cardiovascular abnormalities in patients with DDX3X -syndrome. Results A total of 200 patients with DDX3X -syndrome were analyzed, comprising 14 patients from our institutional cohort and 186 patients identified through a systematic review of 9 published studies. Our institutional cohort included 14 patients (12 females and 2 males) from 13 unrelated families diagnosed with DDX3X -syndrome, at a median age of 4.5 years (IQR 1.2–9.5). Echocardiogram was performed on nine patients, and cardiovascular abnormalities were found in 7 out of 9 patients who underwent echocardiography (78%), two of whom had major congenital heart defect (CHD) requiring surgical intervention. At the time of assessment, 13 individuals were still alive, while one had died at age six due to extracardiac complications. The systematic review included 9 studies involving 186 patients, of whom 32 (17.4%, 25 females and 7 males) had reported cardiovascular abnormalities, ranging from simple CHDs to more complex defects. Conclusion DDX3X -syndrome carries a significant cardiovascular burden, which is possibly higher than previously reported, including complex congenital heart disease requiring surgical repair. A thorough cardiovascular assessment, including an electrocardiogram and echocardiogram, should be universally recommended for all patients at the time of diagnosis.

Background: Hepatorenal syndrome–acute kidney injury (HRS-AKI) is associated with high mortality in cirrhosis. Recent FDA approval of terlipressin and updated clinical guidance have expanded management options, but real-world practice patterns remain unknown. Methods: We conducted a nationwide survey of U.S. hepatology providers regarding HRS-AKI management practices. The 33-question survey assessed provider demographics, vasoconstrictor selection, treatment timing, and adherence to guideline recommendations. Results: Among 162 respondents, most were hepatologists (94%) at academic centers (83%). Only 11% obtained a nephrology consultation at AKI detection, with 44% waiting until worsening renal function. Terlipressin was available at 80% of institutions but more commonly at academic centers (84% vs. 53%, p =0.003). Consistent with guideline recommendations, 77% of providers initiate vasoconstrictors only after completing a trial of volume expansion (if no renal improvement), particularly in academic centers (80% vs. 60% non-academic, p =0.03). Terlipressin (49%) and midodrine/octreotide (44%) were preferred first-line treatments, with providers at academic centers more likely to use midodrine/octreotide (46% vs. 30%, p =0.008). Mean arterial pressure was used by 62% of providers to guide vasoconstrictor dosing. Most providers (73%) discontinued vasoconstrictor treatment after 4 days if no improvement. Conclusions: Significant variations exist between guideline recommendations and real-world HRS-AKI management, especially first-line treatment choice, treatment monitoring, and nephrology consultation. These findings highlight opportunities to improve guideline implementation and identify areas where practice patterns might inform provider education and future guidance updates.

Background: A 2-stage approach is most commonly used to treat periprosthetic joint infection (PJI). Some successful studies of the 1-stage approach were underpowered, lacked a 2-stage comparative group, and excluded patients with draining sinuses, comorbidities, and/or antibiotic-resistant organisms. Given the morbidity and expense associated with 2-stage treatment, we conducted a prospective, multicenter, randomized trial to compare the results of 1- and 2-stage PJI treatment, specifically including patients with draining sinuses, comorbidities, and resistant organisms. Methods: Patients presenting for surgical treatment of a chronic PJI with a known organism following primary total hip or knee arthroplasty were included (with infection defined by Musculoskeletal Infection Society [MSIS] criteria). Patients with prior revision, culture-negative infection, or fungal infection, or who were immunosuppressed or had soft-tissue involvement precluding wound closure, were excluded. Patients were classified according to the McPherson host staging system. Clinical success was defined as (1) no clinical failure or reinfection with the same or new organism; (2) no reoperation for PJI; and (3) no PJI-related death. A double-instrument setup was used for all patients, as were similar irrigation and antibiotic protocols. A total of 323 patients (166 one-stage; 157 two-stage) were randomized. Groups were similar with respect to demographics and host classification. After excluding patients who died or were lost to follow-up, 258 of the 323 patients had 2-year follow-up (135 one-stage and 123 two-stage). The rate of patient loss to follow-up was similar between the treatment groups. Results: Sixteen patients in the 1-stage group and 9 patients in the 2-stage group died prior to 2-year follow-up. Overall, the 2-year success rate of 1-stage treatment was 97% (131 of 135), while the success of 2-stage treatment was 91% (112 of 123) (p = 0.04). Compared with the 2-stage group, the 1-stage group had 3-times the odds of overall success in a regression analysis (unadjusted odds ratio = 3.22 [95% confidence interval = 1.0 to 10.38]). After adjusting for specific variables (McPherson host grade, resistant organism, and draining sinuses), 1-stage treatment also had 3-times the odds of success. Conclusions: The results of this prospective randomized trial indicated that 1-stage treatment (97% success) was statistically noninferior to 2-stage treatment (91% success) when treating chronic PJI following primary total hip or knee arthroplasty, provided the protocols described here are explicitly followed. Extrapolation to other patient cohorts and clinical situations should be avoided. Level of Evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.