Faculty Bibliography

BACKGROUND:Next-generation sequencing (NGS) testing in patients with metastatic non-small cell lung cancer (mNSCLC) identifies actionable driver oncogenes (ADO) and targeted treatment (TT). Potential inequities were evaluated in NGS testing and TT in patients with mNSCLC. PATIENTS AND METHODS/METHODS:This retrospective study used a nationwide electronic health record-derived deidentified database for patients ≥18 years diagnosed with mNSCLC between 4/2018 and 4/2024, ≥2 recorded visits, and follow-up ≥90 days post diagnosis. For TT, patients must have received NGS testing before first-line (1L) treatment and harbored ≥1 1L ADO. RESULTS:A total of 15 392 patients with mNSCLC were included: 66% with commercial insurance, 16% with Medicare, 12% with other, 4% with Medicaid, and 3% with other government insurance. Patients with commercial insurance had significantly higher odds of receiving NGS testing vs Medicare, Medicaid, or other insurance. While patient characteristics varied across insurances, the effect of insurance type on NGS testing did not differ by race/ethnicity, age, or socioeconomic status (SES). Site of care was a significant effect modifier, with increased odds of NGS testing for community vs academic settings for commercial, Medicare, and other insurance and decreased odds for Medicaid. When all patients received NGS testing, significantly lower odds of receiving TT occurred for patients with SES 2 vs SES 1 (lowest); higher odds occurred for Asian vs white patients. CONCLUSION/CONCLUSIONS:Insurance is a key contributor to inequity in NGS testing. When all patients received NGS testing, equity was achieved in patients receiving TT, except those with lower SES, who potentially did not qualify for Medicaid.

BACKGROUND/UNASSIGNED:The SPAN (Stroke Preclinical Assessment Network) is a confirmatory trial platform to test the efficacy and safety of candidate cerebroprotective interventions in acute stroke. As the largest multicenter preclinical stroke trial to date, the SPAN1 trial (first SPAN) prospectively captured many biological and procedural variables, revealing a high degree of heterogeneity introduced by the multicenter approach that may impact stroke outcomes. Here, we examined the biological and procedural predictors of tissue and neurological outcomes after focal cerebral ischemic stroke in rats. METHODS/UNASSIGNED:SPAN1 enrolled and randomized 698 rats to various active treatment arms or controls. Rats were subjected to transient middle cerebral artery occlusion for 60 (spontaneously hypertensive rats) or 120 minutes (young, healthy Sprague-Dawley rats) and followed for 1 month. Eight biological and procedural independent variables (sex, weight, strain, intervention arm, site, endovascular filament silicone tip coating characteristics, anesthesia duration, and intervention protocol) and 5 dependent outcome variables (weight loss, 4-point neuroscore, corner test, infarct volume, and mortality) were captured. Multivariable regression was used to identify independent predictors of each outcome readout and determine their effect sizes. RESULTS/UNASSIGNED:Spontaneously hypertensive rats exhibited larger infarcts than Sprague-Dawley rats, particularly among females. Neuroscores were also worse in spontaneously hypertensive rats. Prolonged anesthesia exposure was associated with smaller cortical and hippocampal infarcts. Filament thickness and length showed a complex association with different regional infarct volumes, neuroscores, weight loss, and corner test outcomes. Mortality was worse among females. Bivariate analysis of dependent variables revealed moderate correlations among the tissue and neurological outcomes. CONCLUSIONS/UNASSIGNED:Using the large and multicenter, prospective SPAN1 dataset, our multivariable analyses identified several predictors influencing rat middle cerebral artery occlusion outcomes and refuted others previously reported. Investigators should consider whether biological and procedural predictors identified herein should be standardized, accounted for, or stratified during subject allocation to decrease variability and avoid confounders in future multicenter preclinical trials.

BACKGROUND:To progress adolescent mental health research beyond our present achievements-a complex account of brain and environmental risk factors without understanding neurobiological embedding in the environment-we need methods to uncover relationships between the developing brain and real-world environmental experiences. METHODS:We investigated associations between brain function, environments, and emotional and behavioral problems using participants from the Adolescent Brain Cognitive Development (ABCD) Study (n = 2401 female). We applied manifold learning, a promising technique for uncovering latent structure from high-dimensional biomedical data such as functional magnetic resonance imaging. Specifically, we developed exogenous PHATE (potential of heat-diffusion for affinity-based trajectory embedding) (E-PHATE) to model brain-environment interactions. We used E-PHATE embeddings of participants' brain activation during emotional and cognitive processing tasks to predict individual differences in cognition and emotional and behavioral problems both cross-sectionally and longitudinally. RESULTS:E-PHATE embeddings of participants' brain activation and environments at baseline showed moderate-to-large associations with total, externalizing, and internalizing problems at baseline, across several subcortical regions and large-scale cortical networks, compared with the zero-to-small effects achieved by voxelwise data or common low-dimensional embedding methods. E-PHATE embeddings of the brain and environment at baseline were also related to emotional and behavioral problems 2 years later. These longitudinal predictions showed a consistent moderate effect in the frontoparietal and attention networks. CONCLUSIONS:The embedding of the adolescent brain in the environment yields enriched insight into emotional and behavioral problems. Using E-PHATE, we demonstrated how the harmonization of cutting-edge computational methods with longstanding developmental theories advances the detection and prediction of adolescent emotional and behavioral problems.

BACKGROUND/UNASSIGNED:The SPAN (Stroke Preclinical Assessment Network) is a confirmatory multicenter trial network to test cerebroprotective interventions in experimental acute stroke. In a first-of-its-kind trial, SPAN tested 6 interventions in a rodent model of transient focal ischemic stroke. Here, we report the efficacy of fasudil, an isoform-nonselective rho-associated kinase inhibitor, on primary and secondary outcomes in the SPAN trial. METHODS/UNASSIGNED:Fasudil was administered at 10 mg/kg intraperitoneally every 12 hours for 6 doses starting 5 minutes before reperfusion in a 60-minute endovascular filament middle cerebral artery occlusion model. The active treatment arm (n=345) was compared with the pooled intraperitoneal and intravenous vehicle arms (n=344). In addition to healthy young mice, the trial included aging mice (16±1 months), diet-induced obese mice, and spontaneously hypertensive rats. The a priori fasudil substudy design stipulated the modified corner test performance on day 28 as the primary end point and separate analyses for mice and spontaneously hypertensive rats using the modified intention-to-treat cohort. RESULTS/UNASSIGNED:=0.022). The effect appeared stronger in aging mice and when ischemia was induced during the active circadian stage. Fasudil did not show any benefit in the spontaneously hypertensive rats. Alternative analyses using the per-protocol population and imputation generally yielded similar conclusions. CONCLUSIONS/UNASSIGNED:Our results reveal a favorable therapeutic profile for fasudil, supporting future translational development of rho-associated kinase inhibitors in ischemic stroke.

BACKGROUND/UNASSIGNED:Past failures in translating stroke cerebroprotection provoked calls for a more rigorous methodological approach, leading to the stroke preclinical assessment network SPAN (Stroke Preclinical Assessment Network), where uric acid (UA) treatment exceeded a prespecified efficacy boundary for the primary functional outcome. Still, successful translation to humans requires confirmation of the effect of UA across key biological variables relevant to patients with stroke. METHODS/UNASSIGNED:We measured the effects of intravenous UA treatment (16 mg/kg) versus intravenous saline in groups of animals enrolled in the SPAN network with diverse comorbidities, sex, and age. The masked study drug or placebo was administered during reperfusion in rodents undergoing a transient middle cerebral artery filament occlusion. The primary outcome was the modified corner test index at day 30 poststroke, and numerous secondary outcomes were collected. A modified intention-to-treat population was used in the analysis. We tested for any interactions with sex, age, and comorbidities (obesity-induced hyperglycemia and hypertension). RESULTS/UNASSIGNED:=0.011). Brain morphometry at day 2 and 30 was comparable between the treatment groups. The improved functional outcome and survival in UA-treated animals were preserved across different species, sexes, ages, and comorbidities. CONCLUSIONS/UNASSIGNED:UA provides ischemic stroke cerebroprotection across key relevant biological variables, making it a promising intervention to be further tested in human clinical trials.

X-ray absorption spectroscopy (XAS) of 3d transition metals provides important electronic structure information for many fields. However, X-ray-induced radiation damage under physiological temperature has prevented using this method to study dilute aqueous systems, such as metalloenzymes, as the catalytic reaction proceeds. Here we present a new approach to enable operando XAS of dilute biological samples and demonstrate its feasibility with K-edge XAS spectra from the Mn cluster in photosystem II and the Fe-S centers in photosystem I. This approach combines highly efficient sample delivery strategies and a robust signal normalization method with high-transmission Bragg diffraction-based spectrometers at X-ray free-electron lasers (XFELs) in a damage-free, shot-by-shot mode. These photon-out spectrometers have been optimized for discriminating the metal Mn/Fe Kα fluorescence signals from the overwhelming scattering background present on currently available detectors for XFELs that lack suitable energy discrimination. We quantify the enhanced performance metrics of the spectrometer and discuss its potential applications for acquiring time-resolved XAS spectra of biological samples during their reactions at XFELs.

Mitochondrial Ca²⁺ transport regulates many neuronal functions including synaptic transmission, ATP production, gene expression and neuronal survival. The mitochondrial Ca²⁺ uniporter (MCU) is the core molecular component of the mitochondrial Ca²⁺ uptake complex in the inner mitochondrial membrane. MCUb is a paralog of MCU that negatively regulates mitochondrial Ca²⁺ uptake in the heart and the cells of the immune system. However, the function of MCUb in the brain is largely unknown. Here, we report that MCUb knockout (KO) led to enhanced mitochondrial Ca²⁺ uptake in cortical neurons. By simultaneously monitoring changes in cytosolic and mitochondrial Ca²⁺ concentrations, [Ca²⁺]_cyt and [Ca²⁺]_mt, respectively, we also found that MCUb KO reduced the [Ca²⁺]_cyt threshold required to induce mitochondrial uptake in cortical neurons during electrical stimulation. Exposure of cortical neurons to toxic concentrations of glutamate led to a collapse of mitochondrial membrane potential (ΔΨ_mt) and [Ca²⁺]_cyt deregulation, and MCUb deletion accelerated the development of both events. Furthermore, using the middle cerebral artery occlusion (MCAO) as a model of transient ischemic stroke in mice, we found that MCUb KO significantly increased MCAO-induced brain damage in male, but not female mice. These results suggest that MCUb regulates neuronal Ca²⁺ dynamics and excitotoxicity and reveal a sex-dependent role of MCUb in controlling resistance to brain damage following ischemic stroke.

BACKGROUND:Freezing of gait (FOG) is a common gait disorder that often accompanies Parkinson's disease (PD). The current understanding of brain functional organization in FOG was built on the assumption that the functional connectivity (FC) of networks is static, but FC changes dynamically over time. We aimed to characterize the dynamic functional connectivity (DFC) in patients with FOG based on high temporal-resolution functional MRI (fMRI). METHODS:Eighty-seven PD patients, including 29 with FOG and 58 without FOG, and 32 healthy controls underwent resting-state fMRI. Spatial independent component analysis and a sliding-window approach were used to estimate DFC. RESULTS:Four patterns of structured FC 'states' were identified: a frequent and sparsely connected network (State I), a less frequent but highly synchronized network (State IV), and two states with opposite connecting directions between the visual network and the sensorimotor network (positively connected in State II, negatively connected in State III). Compared with the non-FOG group, patients with FOG spent significantly less time in State II and more time in State III. The longer dwell time in State III was correlated with more severe FOG symptoms. The fractional window of State III tended to correlate to visual-spatial and executive dysfunction in FOG. Moreover, fewer transitions between brain states and lower variability in local efficiency were observed in FOG, suggesting a relatively 'rigid' brain. CONCLUSIONS:This study highlights how visuomotor network dynamics are related to the presence and severity of FOG in PD patients, which provides new insights into understanding the pathophysiological mechanisms that underly FOG. © 2025 International Parkinson and Movement Disorder Society.

Respiratory tract infections (RTIs) caused by bacteria or viruses are associated with stroke severity. Recent studies have revealed an imbalance in the von Willebrand factor (VWF)-ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin motifs 13) axis in patients with RTIs, including coronavirus disease 2019. We examined whether this imbalance contributes to RTI-mediated stroke severity. Wild-type (WT), Vwf-/-, or Adamts13-/- mice with respective littermate controls (Vwf+/+ or Adamts13+/+) were infected intranasally with sublethal doses of Staphylococcus aureus (on days 0, 2, and 5) or mouse-adapted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; on day 0) and subjected to transient (30 or 45 minutes) cerebral ischemia followed by reperfusion. In S aureus-infected mice, infarct volumes were assessed on day 2 and functional outcomes on weeks 1 and 4 after reperfusion. In SARS-CoV-2-infected mice, infarct volumes and functional outcomes (Bederson score) were assessed on day 1 after reperfusion. We demonstrated that S aureus or SARS-CoV-2 RTI was accompanied by an imbalance in the VWF-ADAMTS13 axis and an increase in plasma levels of interleukin-6, C-X-C motif chemokine ligand 1, and monocyte chemoattractant protein-1, which was associated with larger infarcts and worse functional outcomes (P < .05 vs mock infection). S aureus- or SARS-CoV-2-infected Vwf-/- mice exhibited reduced infarcts and improved functional outcomes, whereas infected Adamts13-/- mice displayed greater stroke severity (P < .05 vs control). In the models of RTI preceding stroke, VWF contributes to stroke severity, whereas ADAMTS13 is protective.