Citations

Transactive response DNA-binding protein of 43 kDa (TDP-43) and tau proteins play critical roles in neurodegenerative diseases, particularly frontotemporal lobar degeneration (FTLD) and Alzheimer’s disease (AD). The co-occurrence of TDP-43 and tau pathologies raises questions about their role in disease progression. This review explores the simultaneous presence of tau and TDP-43 co-pathologies, emphasizing their molecular interactions and the resultant neuropathological implications. Additionally, we provide representative examples of their clinical presentations, neuroimaging, and neuropathological findings associated with FTLD-TDP and FTLD-tau, emphasizing the need for a comprehensive understanding of these intertwined pathologies. We analyze various clinical scenarios, including argyrophilic grain disease (AGD), primary age-related tauopathy (PART), and limbic predominant age-related TDP-43 encephalopathy (LATE), to elucidate the complex relationship between these proteinopathies. From the literature, the co-occurrence of tau and TDP-43 is linked to more severe and poorer clinical outcomes compared to isolated pathologies. This review underscores the necessity of considering co-pathologies in the context of FTLD, as they may act as accelerators of cognitive decline. This highlights the importance of integrated approaches in diagnosing and treating neurodegenerative conditions characterized by tau and TDP-43 misfolding. Understanding the interplay between these molecular markers is vital for advancing therapeutic strategies for such disorders.

Objectives Periodic quality control (QC) testing of ultrasound (US) imaging systems is essential to ensure and maintain image quality and safety. The study aims to analyze QC findings from medical physics annual surveys of modern clinical US systems in a multi‐institutional survey. Methods QC results from annual surveys between 2018 and 2021 were retrospectively collected from 12 medical physicists from 11 institutions or consulting companies (hereafter referred to as sites). QC tests were classified as scanner‐ and transducer‐related tests, where scanner‐related tests also included evaluation of diagnostic workstation display monitors and routine QC programs if applicable. Test methodology and pass/fail criteria were established by each site. QC findings were defined as results requiring follow‐up action by service engineers, vendors, or other personnel. The percentage of annual findings was calculated for each site and averaged across the years of data contributed. Furthermore, findings across all sites were aggregated for an overall analysis. Results QC data from a total of 1069 scanner tests and 4542 transducer tests were collected. The average annual percentage of scanner‐related findings varied from 0 to 40.8% among all sites (first quartile 8.7%, median 18.2%, and third quartile 34.1%), while that of transducer‐related findings ranged between 0.5% and 19.9% (first quartile 3.9%, median 7.2%, and third quartile 14.5%). For scanner‐related tests, the top 3 categories of findings were associated with physical and mechanical integrity (171 findings, 74.7%), quantitative testing of the scanner display monitor (40 findings, 17.5%), and scanner port creating artifacts (10 findings, 4.4%). The top 3 findings for transducers related to uniformity and artifact (227 findings, 79.9%), physical and mechanical integrity (44 findings, 15.5%), and sensitivity in fundamental mode (9 findings, 3.2%). Conclusions Medical physics annual surveys revealed considerable actionable findings of modern US systems, which inform the status of current US QC practices in the United States and may guide future standardization and recommendation of QC tests.

This study evaluated the effectiveness of using a traditional computed tomography (CT) simulation scan in the Leksell Gamma Knife® Icon™ workflow for stereotactic radiosurgery. We compared two workflows, one involving a traditional CT simulation co-registered with the magnetic resonance imaging (MRI) and cone-beam CT (CBCT) (MRI-CT-CBCT) and another without the CT scan, co-registering the MRI directly with CBCT (MRI-CBCT). The cohort included 50 frame-based (54 targets) and 55 frameless (124 targets) patients treated between August 2020 and December 2022. Target coverage was assessed by the percentage of each target covered by the prescription isodose line. The mean coverage differences for the frame-based and frameless cohorts were −1.20% ± 1.43% and −1.06% ± 1.51%, respectively, with 95% confidence intervals of −1.59, −0.81 and −1.32, −0.79. The MRI-CBCT workflow was deemed noninferior to the MRI-CT-CBCT workflow. Our data indicate that both workflows yield similar results, suggesting that a traditional CT simulation scan is unnecessary.

AbstractThe dual burden of undernutrition and overnutrition requires a greater understanding and commitment to physician training and specialization in nutrition support. Despite the significant healthcare need and existence of organizations focused on nutrition support such as the American Society for Parenteral and Enteral Nutrition (ASPEN), physician involvement in the nutrition care of high‐risk patients remains low. In an ASPEN survey of members, inadequate training among physicians was reported along with significant barriers to involvement in nutrition support, such as insufficient protected time, reduced reimbursement and financial support, inadequate support from administrators or supervisors, as well as a nationwide reduction in number of nutrition support teams. These changes in the healthcare landscape prompted the ASPEN Physician Engagement Committee to develop a critical review focused on domains of nutrition risk assessment, enteral and parenteral access and support, scholarly activities, board certification, administrative responsibilities, education and training opportunities, coding, and reimbursement. The aim of this critical review is to capacitate physicians to engage in nutrition support and enhance their acumen in clinical nutrition to improve patient care and enrich personal and professional development.

Abstract Purpose: Navtemadlin is a potent small-molecule inhibitor of MDM2, which has completed a phase 0 window-of-opportunity study in glioblastoma (GBM). To optimally interpret the clinical data, a detailed analysis of navtemadlin pharmacokinetics (PK), pharmacodynamics, and efficacy was performed in GBM patient-derived xenografts (PDX). Experimental Design: Response to navtemadlin was characterized in vitro and in vivo in GBM PDXs with and without MDM2 amplification. Efficacy in vivo was integrated with measured plasma and intra-tumoral drug levels to develop a translational PK/efficacy model comparing exposure effective in PDX to exposure achieved in phase 0 patient samples. Results: In vitro, navtemadlin showed robust on-target activity in TP53–wild-type GBM. In vivo efficacy strongly correlated with MDM2 amplification status. In subcutaneous PDXs, navtemadlin significantly extended survival when dosed at 25 mg/kg in an MDM2-amplified PDX compared with 100 mg/kg in a non-amplified PDX. Central nervous system distribution was limited by blood–brain barrier efflux (Kp_brain = 0.009). In an MDM2-amplified orthotopic PDX model, navtemadlin was ineffective at 100 mg/kg; when established in mice with deficient blood–brain barrier efflux (Rag−/−Abcb1a−/−Abcg2−/−), 25 mg/kg doubled survival. A tumor PK/efficacy model was built to define target exposure for efficacy in GBM, using the effective 25 mg/kg dose. Modeled exposures exceeded this threshold in three (of 16) tumor samples from phase 0 study patients at the 240 mg dose level. Conclusions: Navtemadlin efficacy was highly dependent on adequate brain penetration. Our translational PK/efficacy model suggests that the minimum effective tumor exposures were achieved only in a minority of patients with GBM.

Background: Progressive apraxia of speech (PAOS) is a neurodegenerative disorder most commonly arising from a 4-repeat tauopathy that affects the programming or planning of speech, although many patients develop a Parkinson-plus syndrome. The role of neuroinflammation as a disease mechanism is unknown. We investigated the spatial pattern of neuroinflammation in PAOS using PET and evaluated whether it is associated with disease severity, presence of Parkinson-plus features, and tau PET uptake. Patients and Methods: Twenty-five PAOS patients (13 with Parkinson-plus features) and 30 controls underwent inflammatory 11C-ER176 and tau 18F-flortaucipir PET scans as well as detailed clinical assessments. Multiple linear regression analyses compared the inflammatory standardized uptake value ratio (SUVR) between PAOS and controls and assessed the relationship with clinical test scores. Pearson correlation analysis examined the relationship between inflammatory and tau SUVRs. Results: PAOS had greater neuroinflammatory SUVR than controls in the precentral, supplementary motor area, frontal gyri, putamen, pallidum, subthalamic nucleus, and red nucleus (adjusted P < 0.05). Greater neuroinflammation was associated with worse parkinsonism, and patients who had developed Parkinson-plus features showed a broader pattern of neuroinflammation, extending to prefrontal, temporal and parietal cortices. Neuroinflammation correlated with tau uptake in most (96%) PAOS patients (r > 0.3, P < 0.05). The higher correlation was associated with worse parkinsonism (r = 0.61, P < 0.05) and disease severity (r = 0.54, P < 0.05). Conclusions: 11C-ER176 PET analysis demonstrates neuroinflammation in frontal and subcortical regions in PAOS which is particularly severe and widespread with the development of Parkinson-plus clinical features. The colocalization of neuroinflammation and tau may support a relationship between these disease mechanisms.