Large-scale neurophysiology and single-cell profiling in human neuroscience.

Advances in large-scale single-unit human neurophysiology, single-cell RNA sequencing, spatial transcriptomics and long-term ex vivo tissue culture of surgically resected human brain tissue have provided an unprecedented opportunity to study human neuroscience. In this Perspective, we describe the development of these paradigms, including Neuropixels and recent brain-cell atlas efforts, and discuss how their convergence will further investigations into the cellular underpinnings of network-level activity in the human brain. Specifically, we introduce a workflow in which functionally mapped samples of human brain tissue resected during awake brain surgery can be cultured ex vivo for multi-modal cellular and functional profiling. We then explore how advances in human neuroscience will affect clinical practice, and conclude by discussing societal and ethical implications to consider. Potential findings from the field of human neuroscience will be vast, ranging from insights into human neurodiversity and evolution to providing cell-type-specific access to study and manipulate diseased circuits in pathology. This Perspective aims to provide a unifying framework for the field of human neuroscience as we welcome an exciting era for understanding the functional cytoarchitecture of the human brain.

Glioblastoma remodelling of human neural circuits decreases survival.

Gliomas synaptically integrate into neural circuits1,2. Previous research has demonstrated bidirectional interactions between neurons and glioma cells, with neuronal activity driving glioma growth1-4 and gliomas increasing neuronal excitability2,5-8. Here we sought to determine how glioma-induced neuronal changes influence neural circuits underlying cognition and whether these interactions influence patient survival. Using intracranial brain recordings during lexical retrieval language tasks in awake humans together with site-specific tumour tissue biopsies and cell biology experiments, we find that gliomas remodel functional neural circuitry such that task-relevant neural responses activate tumour-infiltrated cortex well beyond the cortical regions that are normally recruited in the healthy brain. Site-directed biopsies from regions within the tumour that exhibit high functional connectivity between the tumour and the rest of the brain are enriched for a glioblastoma subpopulation that exhibits a distinct synaptogenic and neuronotrophic phenotype. Tumour cells from functionally connected regions secrete the synaptogenic factor thrombospondin-1, which contributes to the differential neuron-glioma interactions observed in functionally connected tumour regions compared with tumour regions with less functional connectivity. Pharmacological inhibition of thrombospondin-1 using the FDA-approved drug gabapentin decreases glioblastoma proliferation. The degree of functional connectivity between glioblastoma and the normal brain negatively affects both patient survival and performance in language tasks. These data demonstrate that high-grade gliomas functionally remodel neural circuits in the human brain, which both promotes tumour progression and impairs cognition.

Postdissection aortic aneurysm sac enlargement after fenestrated and branched endovascular aortic aneurysm repair.

OBJECTIVES: Aneurysm sac changes after fenestrated-branched endovascular aneurysm repair (FBEVAR) for postdissection thoracoabdominal aortic aneurysms (PD-TAAs) are poorly understood. Partial thrombosis of the false lumen and endoleaks may impair sac regression. To characterize sac changes after FBEVAR for PD-TAAs, this study examined midterm results and predictors for sac enlargement. METHODS: FBEVARs performed for PD-TAAs in 10 physician-sponsored investigational device exemption studies from 2008 to 2023 were analyzed. The maximum aortic aneurysm diameter was compared between the 30-day computed tomography angiogram and follow-up imaging studies. Aneurysm sac enlargement was defined as an increase in diameter of ≥5 mm. Kaplan-Meier curves and Cox regression were used to evaluate sac enlargement and midterm FBEVAR outcomes. RESULTS: Among 3296 FBEVARs, 290 patients (72.4% male; median age, 68.4 years) were treated for PD-TAAs. Most aneurysms treated were extent II (72%) and III (12%). Mean aneurysm diameter was 66.5 ± 11.2 mm. Mortality at 30 days was 1.4%. At a mean follow-up of 2.9 ± 1.9 years, at least one follow-up imaging study revealed sac enlargement in 43 patients (15%), sac regression in 115 patients (40%), and neither enlargement nor regression in 137 (47%); 5 (2%) demonstrated both expansion and regression during follow-up. Freedom from aneurysm sac enlargement was 93%, 82%, and 80% at 1, 3, and 5 years, respectively. Overall, endoleaks were detected in 27 patients (63%) with sac enlargement and 143 patients (58%) without enlargement (P = .54). Sac enlargement was significantly more frequent among older patients (mean age at the index procedure, 70.2 ± 8.9 years vs 66.5 ± 11 years; P = .04) and those with type II endoleaks at 1 year (74% vs 52%; P = .031). Cox regression revealed age >70 years at baseline (hazard ratio [HR], 2.146; 95% confidence interval [CI], 1.167-3.944; P = .010) and presence of type II endoleak at 1 year (HR, 2.25; 95% CI, 1.07-4.79; P = .032) were independent predictors of sac enlargement. Patient survival was 92%, 81%, and 68% at 1, 3, and 5 years, respectively. Cumulative target vessel instability was 7%, and aneurysm-related mortality was 2% at 5 years. At least 42% of patients required secondary interventions. Sac enlargement did not affect patient survival. CONCLUSIONS: Aneurysm sac enlargement occurs in 15% of patients after FBEVAR for PD-TAAs. Elderly patients (>70 years at baseline) and those with type II endoleaks at 1 year may need closer monitoring and secondary interventions to prevent sac enlargement. Despite sac enlargement in some patients, aneurysm-related mortality at 5 years remains low and overall survival was not associated with sac enlargement.

Performance of an Electronic Medical Record-based 'Syphilis Flag' in Identifying at-risk Patients in an Emergency Department.

BACKGROUND: The United States (US) has seen a > 40% increase in syphilis cases since 2017. Early disease identification and treatment are crucial. This review sought to identify emergency department (ED) patients at risk for syphilis. METHODS: A 30-day retrospective review was conducted of visits to a single ED. Patient visits were assessed for pre-determined syphilis 'flags' to include history of sexually transmitted infection (STI), current chief complaint (CC) or reason for visit (RFV) keyword(s) suggestive of potential STI, or positive pregnancy test. Flagged charts were assessed for STI testing results within six-months of ED visit. Data was analyzed using chi-square. RESULTS: There were 5537 total patient encounters, resulting in 455 flagged visits from 408 (8.4%) unique individuals, majority female (282, 69.1%; p < .001)), Black (251, 61.5%; p < .001), aged 15-44 (308, 75.5%; p < .001). Chief complaint was the most frequent flag (65.3%) followed by RFV (37.4%), prior STI (31.0%), and pregnancy (12.3%). Syphilis testing data was available for 120 flagged patents; 29 (24.2%) screened positive, including 11 (2.7% of total flagged cohort) with evidence for active infection. Among those, majority were Black (90.9%), male (72.7%), aged 25 to 34 (63.6%); nine (81.8%) had concomitant HIV; in active infection, prior STI flag was most common (72.7%), followed by CC (54.5%) and RFV (45.5%). CONCLUSION: This review demonstrates the performance of an EMR-based 'syphilis risk flag' screener applied to ED patients. Sex- and race-based discrepancies exist in flag rates, which may be reflective of sex- and race-based epidemiologic discrepancies in STI incidence.

Time-varying brentuximab vedotin pharmacokinetics and weight-based dosing in paediatric patients despite lower exposure in those aged 2 to <6 and 6-11 years.

AIMS: We studied the pharmacokinetics and exposure-response relationships of the brentuximab vedotin (BV) antibody-drug conjugate (ADC) and unconjugated monomethyl auristatin E in haematologic malignancies. METHODS: This population pharmacokinetic analysis included data from five adult and three paediatric studies. Exposures in virtual adult and paediatric populations following BV 1.8 mg/kg (maximum 180 mg) intravenously every 3 weeks were simulated. Clinical endpoints included overall response rate, grade ≥2 peripheral neuropathy (PN) and grade ≥3 neutropenia. RESULTS: BV ADC exhibited linear pharmacokinetics, well-described by a three-compartment model, with body weight being the only significant covariate for exposure. Monomethyl auristatin E exhibited time-varying formation rate. Simulated steady-state BV ADC exposures in patients aged 12 to <18 years were similar to those of adult patients, but 23%-38% lower in patients aged 2 to <12 years. Despite lower exposure, clinical activity was observed with BV 1.8 mg/kg every 3 weeks in those aged 2 to <12 years (overall response rate: 2 to <12 years, 60%; 12 to <18 years, 43%). In adult, but not paediatric patients, increased BV ADC exposures were associated with grade ≥2 PN and grade ≥3 neutropenia occurrence. CONCLUSIONS: BV pharmacokinetics in adult and paediatric patients were consistent. BV ADC exposures were lower in patients aged 2 to <12 years vs. ≥12 years, but no apparent clinically relevant differences in efficacy, grade ≥2 PN or grade ≥3 neutropenia were observed. These data support body weight-based dosing of BV in patients irrespective of age; thus, dose adjustment in those 2 to <12 years does not appear warranted.

Tracheal Intubation by Advanced Practice Registered Nurses in Pediatric Critical Care: Retrospective Study From the National Emergency Airway for Children Registry (2015-2019).

OBJECTIVES: To describe tracheal intubation (TI) practice by Advanced Practice Registered Nurses (APRNs) in North American PICUs, including rates of TI-associated events (TIAEs) from 2015 to 2019. DESIGN/SETTING: Retrospective study using the National Emergency Airway Registry for Children with all TIs performed in PICU and pediatric cardiac ICU between January 2015 and December 2019. The primary outcome was first attempt TI success rate. Secondary outcomes were TIAEs, severe TIAEs, and hypoxemia. SUBJECTS: Critically ill children requiring TI in a PICU or pediatric cardiac ICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 11,012 TIs, APRNs performed 1,626 (14.7%). Overall, TI by APRNs, compared with other clinicians, occurred less frequently in patients with known difficult airway (11.1% vs. 14.3%; p < 0.001), but more frequently in infants younger than 1 year old (55.9% vs. 44.4%; p < 0.0001), and in patients with cardiac disease (26.3% vs. 15.9%; p < 0.0001).There was lower odds of success in first attempt TI for APRNs vs. other clinicians (adjusted odds ratio, 0.70; 95% CI, 0.62-0.79). We failed to identify a difference in rates of TIAE, severe TIAE, and oxygen desaturation events for TIs by APRNs compared with other clinicians. The TI first attempt success rate improved with APRN experience (< 1 yr: 54.2%, 1-5 yr: 59.4%, 6-10 yr: 67.6%, > 10 yr: 63.1%; p = 0.021). CONCLUSIONS: TI performed by APRNs was associated with lower odds of first attempt success when compared with other ICU clinicians although there was no appreciable difference in procedural adverse events. There appears to be a positive relationship between experience and success rates. These data suggest there is an ongoing need for opportunities to build on TI competency with APRNs.

Functional alterations in cortical processing of speech in glioma-infiltrated cortex.

Recent developments in the biology of malignant gliomas have demonstrated that glioma cells interact with neurons through both paracrine signaling and electrochemical synapses. Glioma-neuron interactions consequently modulate the excitability of local neuronal circuits, and it is unclear the extent to which glioma-infiltrated cortex can meaningfully participate in neural computations. For example, gliomas may result in a local disorganization of activity that impedes the transient synchronization of neural oscillations. Alternatively, glioma-infiltrated cortex may retain the ability to engage in synchronized activity in a manner similar to normal-appearing cortex but exhibit other altered spatiotemporal patterns of activity with subsequent impact on cognitive processing. Here, we use subdural electrocorticography to sample both normal-appearing and glioma-infiltrated cortex during speech. We find that glioma-infiltrated cortex engages in synchronous activity during task performance in a manner similar to normal-appearing cortex but recruits a diffuse spatial network. On a temporal scale, we show that signals from glioma-infiltrated cortex have decreased entropy, which may affect its ability to encode information during nuanced tasks such as production of monosyllabic versus polysyllabic words. Furthermore, we show that temporal decoding strategies for distinguishing monosyllabic from polysyllabic words were feasible for signals arising from normal-appearing cortex but not from glioma-infiltrated cortex. These findings inform our understanding of cognitive processing in chronic disease states and have implications for neuromodulation and prosthetics in patients with malignant gliomas.

Ketamine Use in the Intubation of Critically Ill Children with Neurological Indications: A Multicenter Retrospective Analysis.

BACKGROUND: Ketamine has traditionally been avoided for tracheal intubations (TIs) in patients with acute neurological conditions. We evaluate its current usage pattern in these patients and any associated adverse events. METHODS: We conducted a retrospective observational cohort study of critically ill children undergoing TI for neurological indications in 53 international pediatric intensive care units and emergency departments. We screened all intubations from 2014 to 2020 entered into the multicenter National Emergency Airway Registry for Children (NEAR4KIDS) registry database. Patients were included if they were under the age of 18 years and underwent TI for a primary neurological indication. Usage patterns and reported periprocedural composite adverse outcomes (hypoxemia < 80%, hypotension/hypertension, cardiac arrest, and dysrhythmia) were noted. RESULTS: Of 21,562 TIs, 2,073 (9.6%) were performed for a primary neurological indication, including 190 for traumatic brain injury/trauma. Patients received ketamine in 495 TIs (23.9%), which increased from 10% in 2014 to 41% in 2020 (p < 0.001). Ketamine use was associated with a coindication of respiratory failure, difficult airway history, and use of vagolytic agents, apneic oxygenation, and video laryngoscopy. Composite adverse outcomes were reported in 289 (13.9%) Tis and were more common in the ketamine group (17.0% vs. 13.0%, p = 0.026). After adjusting for location, patient age and codiagnoses, the presence of respiratory failure and shock, difficult airway history, provider demographics, intubating device, and the use of apneic oxygenation, vagolytic agents, and neuromuscular blockade, ketamine use was not significantly associated with increased composite adverse outcomes (adjusted odds ratio 1.34, 95% confidence interval CI 0.99-1.81, p = 0.057). This paucity of association remained even when only neurotrauma intubations were considered (10.6% vs. 7.7%, p = 0.528). CONCLUSIONS: This retrospective cohort study did not demonstrate an association between procedural ketamine use and increased risk of peri-intubation hypoxemia and hemodynamic instability in patients intubated for neurological indications.

Absorption, Distribution, Metabolism, and Excretion of Therapeutic Proteins: Current Industry Practices and Future Perspectives.

Therapeutic proteins (TPs) comprise a variety of modalities, including antibody-based drugs, coagulation factors, recombinant cytokines, enzymes, growth factors, and hormones. TPs usually cannot traverse cellular barriers and exert their pharmacological activity by interacting with targets on the exterior membrane of cells or with soluble ligands in the tissue interstitial fluid/blood. Due to their large size, lack of cellular permeability, variation in metabolic fate, and distinct physicochemical characteristics, TPs are subject to different absorption, distribution, metabolism, and excretion (ADME) processes as compared with small molecules. Limited regulatory guidance makes it challenging to determine the most relevant ADME data required for regulatory submissions. The TP ADME working group was sponsored by the Translational and ADME Sciences Leadership Group within the Innovation and Quality (IQ) consortium with objectives to: (1) better understand the current practices of ADME data generated for TPs across IQ member companies, (2) learn about their regulatory strategies and interaction experiences, and (3) provide recommendations on best practices for conducting ADME studies for TPs. To understand current ADME practices and regulatory strategies, an industry-wide survey was conducted within IQ member companies. In addition, ADME data submitted to the U.S. Food and Drug Administration was also collated by reviewing regulatory submission packages of TPs approved between 2011 and 2020. This article summarizes the key learnings from the survey and an overview of ADME data presented in biologics license applications along with future perspectives and recommendations for conducting ADME studies for internal decision-making as well as regulatory submissions for TPs. SIGNIFICANCE STATEMENT: This article provides comprehensive assessment of the current practices of absorption, distribution, metabolism, and excretion (ADME) data generated for therapeutic proteins (TPs) across the Innovation and Quality participating companies and the utility of the data in discovery, development, and regulatory submissions. The TP ADME working group also recommends the best practices for condu-cting ADME studies for internal decision-making and regulatory submissions.

The role of cholesterol binding in the control of cholesterol by the Scap-Insig system.

Scap and Insig, two proteins embedded in the membrane of the endoplasmic reticulum (ER), regulate the synthesis of cholesterol in animal cells by forming a dimer in the presence of high concentrations of cholesterol. Cryo-electron microscopic structures for the Scap-Insig dimer show a sterol-binding site at the dimer interface, but none of the structures include cholesterol itself. Here, a molecular docking approach developed to characterise cholesterol binding to the transmembrane (TM) regions of membrane proteins is used to characterise cholesterol binding to sites on the TM surface of the dimer and to the interfacial binding site. Binding of cholesterol is also observed at sites on the extra-membranous luminal domains of Scap, but the properties of these sites suggest that they will be unoccupied in vivo. Comparing the structure of Scap in the dimer with that predicted by AlphaFold for monomeric Scap suggests that dimer formation could result in relocation of TM helix 7 of Scap and of the loop between TM6 and 7, and that this could be the key change on Scap that signals that there is a high concentration of cholesterol in the ER.

Transcriptional analysis identifies potential novel biomarkers associated with successful ex-vivo perfusion of human donor lungs.

BACKGROUND: Transplantation is an effective treatment for end-stage lung disease, but the donor organ shortage is a major problem. Ex-vivo lung perfusion (EVLP) of extended criteria organs enables functional assessment to facilitate clinical decision-making around utilization, but the molecular processes occurring during EVLP, and how they differ between more or less viable lungs, remain to be determined. METHODS: We used RNA sequencing of lung tissue to delineate changes in gene expression occurring in 10 donor lungs undergoing EVLP and compare lungs that were deemed non-transplantable (n = 4) to those deemed transplantable (n = 6) following perfusion. RESULTS: We found that lungs deemed unsuitable for transplantation had increased induction of innate immune pathways and lower expression of oxidative phosphorylation related genes. Furthermore, the expression of SCGB1A1, a gene encoding an anti-inflammatory secretoglobin CC10, and other club cell genes was significantly decreased in non-transplantable lungs, while CHIT-1 was increased. Using a larger validation cohort (n = 17), we confirmed that the ratio of CHIT1 and SCGB1A1 protein levels in lung perfusate have potential utility to distinguish transplantable from non-transplantable lungs (AUC .81). CONCLUSIONS: Together, our data identify novel biomarkers that may assist with pre-transplant lung assessment, as well as pathways that may be amenable to therapeutic intervention during EVLPAQ6.

Interfacial binding sites for cholesterol on GABAA receptors and competition with neurosteroids.

γ-Aminobutyric acid type A (GABAA) receptors in the brain are located in the outer membranes of brain cells where the concentration of cholesterol is high. Of the 25 available high-resolution structures available for GABAA receptors, none were determined in the presence of cholesterol, but four include resolved molecules of cholesterol hemisuccinate (CHS). Here, a molecular docking procedure is used to sweep the transmembrane (TM) surfaces of the receptors for cholesterol binding sites. Cholesterol docking poses determined in this way match 89% of the resolved CHS when CHS molecules deemed unlikely to represent typical bound cholesterols are excluded. The receptors are pentameric, and their TM surfaces consist of a set of five facets, each including pairs of TM helices from two adjacent subunits. Each facet contains hydrophobic hollows running from one side of the membrane to the other, within which are six potential binding sites for cholesterol, three on each side of the membrane. High-resolution structures of GABAA receptors with bound neurosteroids show that neurosteroids bind in these cholesterol binding sites, so the binding of neurosteroids and cholesterol will be competitive.

Atezolizumab for First-Line Treatment of Metastatic Nonsquamous NSCLC.

BACKGROUND: The cancer-cell-killing property of atezolizumab may be enhanced by the blockade of vascular endothelial growth factor-mediated immunosuppression with bevacizumab. This open-label, phase 3 study evaluated atezolizumab plus bevacizumab plus chemotherapy in patients with metastatic nonsquamous non-small-cell lung cancer (NSCLC) who had not previously received chemotherapy. METHODS: We randomly assigned patients to receive atezolizumab plus carboplatin plus paclitaxel (ACP), bevacizumab plus carboplatin plus paclitaxel (BCP), or atezolizumab plus BCP (ABCP) every 3 weeks for four or six cycles, followed by maintenance therapy with atezolizumab, bevacizumab, or both. The two primary end points were investigator-assessed progression-free survival both among patients in the intention-to-treat population who had a wild-type genotype (WT population; patients with EGFR or ALK genetic alterations were excluded) and among patients in the WT population who had high expression of an effector T-cell (Teff) gene signature in the tumor (Teff-high WT population) and overall survival in the WT population. The ABCP group was compared with the BCP group before the ACP group was compared with the BCP group. RESULTS: In the WT population, 356 patients were assigned to the ABCP group, and 336 to the BCP group. The median progression-free survival was longer in the ABCP group than in the BCP group (8.3 months vs. 6.8 months; hazard ratio for disease progression or death, 0.62; 95% confidence interval [CI], 0.52 to 0.74; P<0.001); the corresponding values in the Teff-high WT population were 11.3 months and 6.8 months (hazard ratio, 0.51 [95% CI, 0.38 to 0.68]; P<0.001). Progression-free survival was also longer in the ABCP group than in the BCP group in the entire intention-to-treat population (including those with EGFR or ALK genetic alterations) and among patients with low or negative programmed death ligand 1 (PD-L1) expression, those with low Teff gene-signature expression, and those with liver metastases. Median overall survival among the patients in the WT population was longer in the ABCP group than in the BCP group (19.2 months vs. 14.7 months; hazard ratio for death, 0.78; 95% CI, 0.64 to 0.96; P=0.02). The safety profile of ABCP was consistent with previously reported safety risks of the individual medicines. CONCLUSIONS: The addition of atezolizumab to bevacizumab plus chemotherapy significantly improved progression-free survival and overall survival among patients with metastatic nonsquamous NSCLC, regardless of PD-L1 expression and EGFR or ALK genetic alteration status. (Funded by F. Hoffmann-La Roche/Genentech; IMpower150 ClinicalTrials.gov number, NCT02366143 .).

Sustained Improvement in Tracheal Intubation Safety Across a 15-Center Quality-Improvement Collaborative: An Interventional Study From the National Emergency Airway Registry for Children Investigators.

OBJECTIVES: To evaluate the effect of a tracheal intubation safety bundle on adverse tracheal intubation-associated events across 15 PICUs. DESIGN: Multicenter time-series study. SETTING: PICUs in the United States. PATIENTS: All patients received tracheal intubations in ICUs. INTERVENTIONS: We implemented a tracheal intubation safety bundle as a quality-improvement intervention that includes: 1) quarterly site benchmark performance report and 2) airway safety checklists (preprocedure risk factor, approach, and role planning, preprocedure bedside "time-out," and immediate postprocedure debriefing). We define each quality-improvement phase as baseline (-24 to -12 mo before checklist implementation), benchmark performance reporting only (-12 to 0 mo before checklist implementation), implementation (checklist implementation start to time achieving > 80% bundle adherence), early bundle adherence (0-12 mo), and sustained (late) bundle adherence (12-24 mo). Bundle adherence was defined a priori as greater than 80% of checklist use for tracheal intubations for 3 consecutive months. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the adverse tracheal intubation-associated event, and secondary outcomes included severe tracheal intubation-associated events, multiple tracheal intubation attempts, and hypoxemia less than 80%.From January 2013 to December 2015, out of 19 participating PICUs, 15 ICUs (79%) achieved bundle adherence. Among the 15 ICUs, the adverse tracheal intubation-associated event rates were baseline phase: 217/1,241 (17.5%), benchmark reporting only phase: 257/1,750 (14.7%), early 0-12 month complete bundle compliance phase: 247/1,591 (15.5%), and late 12-24 month complete bundle compliance phase: 137/1,002 (13.7%). After adjusting for patient characteristics and clustering by site, the adverse tracheal intubation-associated event rate significantly decreased compared with baseline: benchmark: odds ratio, 0.83 (0.72-0.97; p = 0.016); early bundle: odds ratio, 0.80 (0.63-1.02; p = 0.074); and late bundle odds ratio, 0.63 (0.47-0.83; p = 0.001). CONCLUSIONS: Effective implementation of a quality-improvement bundle was associated with a decrease in the adverse tracheal intubation-associated event that was sustained for 24 months.

Are Sex Differences in Human Brain Structure Associated With Sex Differences in Behavior?

On average, men and women differ in brain structure and behavior, raising the possibility of a link between sex differences in brain and behavior. But women and men are also subject to different societal and cultural norms. We navigated this challenge by investigating variability of sex-differentiated brain structure within each sex. Using data from the Queensland Twin IMaging study (n = 1,040) and Human Connectome Project (n = 1,113), we obtained data-driven measures of individual differences along a male-female dimension for brain and behavior based on average sex differences in brain structure and behavior, respectively. We found a weak association between these brain and behavioral differences, driven by brain size. These brain and behavioral differences were moderately heritable. Our findings suggest that behavioral sex differences are, to some extent, related to sex differences in brain structure but that this is mainly driven by differences in brain size, and causality should be interpreted cautiously.

Explicit phenomenological solutions for magnetization exposed to an arbitrary NMR diffusion steady state pulse sequence.

Explicit phenomenological solutions to recurrence relations for the bulk transverse and longitudinal magnetization found using the Torrey-Bloch equations with relaxation effects are used to investigate nuclear magnetic resonance (NMR) diffusion measurements. Of particular interest are steady state NMR (self-)diffusion measurements that reduce experimental time that can extend the techniques to quickly reacting systems. The solutions for bulk transverse and longitudinal magnetization presented here are used to investigate the average behavior of the transverse and longitudinal magnetization in forming a steady state and are used to derive new expressions for the steady state longitudinal magnetization. These solutions can be applied to a noninteracting spin 1/2 ensemble undergoing free diffusion exposed to an arbitrary NMR pulse sequence containing arbitrary magnetic field gradient waveforms. The closed algebraic form method presented here has an advantage over iterative procedures for calculating transverse and longitudinal magnetization for the analysis and development of steady state pulse sequences. Previous theoretical results for steady state diffusion measurements are also reproduced. The Mathematica code for these solutions is provided in the supplementary material.

Endovascular embolization versus surgical clipping in a single surgeon series of basilar artery aneurysms: a complementary approach in the endovascular era.

BACKGROUND: Currently, most basilar artery aneurysms (BAAs) are treated endovascularly. Surgery remains an appropriate therapy for a subset of all intracranial aneurysms. Whether open microsurgery would be required or utilized, and to what extent, for BAAs treated by a surgeon who performs both endovascular and open procedures has not been reported. METHODS: Retrospective analysis of prospectively maintained, single-surgeon series of BAAs treated with endovascular or open surgery from the first 5 years of practice. RESULTS: Forty-two procedures were performed in 34 patients to treat BAAs-including aneurysms arising from basilar artery apex, trunk, and perforators. Unruptured BAAs accounted for 35/42 cases (83.3%), and the mean aneurysm diameter was 8.4 ± 5.4 mm. Endovascular coiling-including stent-assisted coiling-accounted for 26/42 (61.9%) treatments and led to complete obliteration in 76.9% of cases. Four patients in the endovascular cohort required re-treatment. Surgical clip reconstruction accounted for 16/42 (38.1%) treatments and led to complete obliteration in 88.5% of cases. Good neurologic outcome (mRS ≤ 2) was achieved in 88.5% and 75.0% of patients in endovascular and open surgical cohorts, respectively (p = 0.40). Univariate logistic regression analysis demonstrated that advanced age (OR 1.11[95% CI 1.01-1.23]) or peri-procedural adverse event (OR 85.0 [95% CI 6.5-118.9]), but not treatment modality (OR 0.39[95% CI 0.08-2.04]), was the predictor of poor neurologic outcome. CONCLUSIONS: Complementary implementation of both endovascular and open surgery facilitates individualized treatment planning of BAAs. By leveraging strengths of both techniques, equivalent clinical outcomes and technical proficiency may be achieved with both modalities.

Hepatitis C Among High-Risk Alabamians: Disease Burden and Screening Effectiveness.

BACKGROUND: The effectiveness of hepatitis C testing and linkage-to-care (LTC) is poorly characterized in low-resource jurisdictions facing gaps in harm reduction, including illegality of syringe exchange services. Effectiveness of a community-based test/LTC program was evaluated in Alabama. METHODS: In 2016-2018, shelters, drug treatment centers (DTCs), AIDS organizations, and Federally Qualified Health Centers (FQHCs) engaged in screening/LTC. A coordinator navigated individuals to confirm viremia and link to substance use treatment or primary care with hepatitis C prescribers. RESULTS: Point-of-care (POC) tested 4293 individuals (10% [427] antibody-positive, 71% [299/419] RNA performed, 80% [241/299] viremia confirmed) and 93% linked to care (225/241). Electronic medical record (EMR)-based reflex strategy screened 4654 (15% [679] antibody positive, 99% [670/679] RNA performed, 64% [433/679] viremia confirmed) and 85% linked to care (368/433). We observed higher odds of RNA confirmation in EMR-based reflex versus POC (OR, 2.07; P < .0001) and higher odds of LTC in EMR-based reflex versus POC (OR, 1.51; P < .0001). Overall, 53% individuals tested were nonbaby boomers. CONCLUSIONS: In Alabama, screening at high-risk settings identified significant hepatitis C burden and reflex testing outperformed point-of-care linkage indicators. Colocating testing in DTCs and treatment in FQHCs provided key LTC venues to at-risk younger groups.

Interfacial Binding Sites for Cholesterol on Kir, Kv, K2P, and Related Potassium Channels.

Inwardly rectifying, voltage-gated, two-pore domain, and related K+ channels are located in eukaryotic membranes rich in cholesterol. Here, molecular docking is used to detect specific binding sites ("hot spots") for cholesterol on K+ channels with characteristics that match those of known cholesterol binding sites. The transmembrane surfaces of all available high-resolution structures for K+ channels were swept for potential binding sites. Cholesterol poses were found to be located largely in hollows between protein ridges. A comparison between cholesterol poses and resolved phospholipids suggests that not all cholesterol molecules binding to the transmembrane surface of a K+ channel will result in displacement of a phospholipid molecule from the surface. Competition between cholesterol binding and binding of anionic phospholipids essential for activity could explain some of the effects of cholesterol on channel function.

Ketamine Use for Tracheal Intubation in Critically Ill Children Is Associated With a Lower Occurrence of Adverse Hemodynamic Events.

OBJECTIVES: Tracheal intubation in critically ill children with shock poses a risk of hemodynamic compromise. Ketamine has been considered the drug of choice for induction in these patients, but limited data exist. We investigated whether the administration of ketamine for tracheal intubation in critically ill children with or without shock was associated with fewer adverse hemodynamic events compared with other induction agents. We also investigated if there was a dose dependence for any association between ketamine use and adverse hemodynamic events. DESIGN: We performed a retrospective analysis using prospectively collected observational data from the National Emergency Airway Registry for Children database from 2013 to 2017. SETTING: Forty international PICUs participating in the National Emergency Airway Registry for Children. PATIENTS: Critically ill children 0-17 years old who underwent tracheal intubation in a PICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The association between ketamine exposure as an induction agent and the occurrence of adverse hemodynamic events during tracheal intubation including dysrhythmia, hypotension, and cardiac arrest was evaluated. We used multivariable logistic regression to account for patient, provider, and practice factors with robust SEs to account for clustering by sites. Of 10,750 tracheal intubations, 32.0% (n = 3,436) included ketamine as an induction agent. The most common diagnoses associated with ketamine use were sepsis and/or shock (49.7%). After adjusting for potential confounders and sites, ketamine use was associated with fewer hemodynamic tracheal intubation associated adverse events compared with other agents (adjusted odds ratio, 0.74; 95% CI, 0.58-0.95). The interaction term between ketamine use and indication for shock was not significant (p = 0.11), indicating ketamine effect to prevent hemodynamic adverse events is consistent in children with or without shock. CONCLUSIONS: Ketamine use for tracheal intubation is associated with fewer hemodynamic tracheal intubation-associated adverse events.