De novo identification of mammalian ciliary motility proteins using cryo-EM.

Dynein-decorated doublet microtubules (DMTs) are critical components of the oscillatory molecular machine of cilia, the axoneme, and have luminal surfaces patterned periodically by microtubule inner proteins (MIPs). Here we present an atomic model of the 48-nm repeat of a mammalian DMT, derived from a cryoelectron microscopy (cryo-EM) map of the complex isolated from bovine respiratory cilia. The structure uncovers principles of doublet microtubule organization and features specific to vertebrate cilia, including previously unknown MIPs, a luminal bundle of tektin filaments, and a pentameric dynein-docking complex. We identify a mechanism for bridging 48- to 24-nm periodicity across the microtubule wall and show that loss of the proteins involved causes defective ciliary motility and laterality abnormalities in zebrafish and mice. Our structure identifies candidate genes for diagnosis of ciliopathies and provides a framework to understand their functions in driving ciliary motility.

A Pilot Study Using Machine Learning Algorithms and Wearable Technology for the Early Detection of Postoperative Complications After Cardiothoracic Surgery.

OBJECTIVE: To evaluate whether a machine learning algorithm (i.e. the "NightSignal" algorithm) can be used for the detection of postoperative complications prior to symptom onset after cardiothoracic surgery. SUMMARY BACKGROUND DATA: Methods that enable the early detection of postoperative complications after cardiothoracic surgery are needed. METHODS: This was a prospective observational cohort study conducted from July 2021 to February 2023 at a single academic tertiary care hospital. Patients aged 18 years or older scheduled to undergo cardiothoracic surgery were recruited. Study participants wore a Fitbit watch continuously for at least 1 week preoperatively and up to 90-days postoperatively. The ability of the NightSignal algorithm-which was previously developed for the early detection of Covid-19-to detect postoperative complications was evaluated. The primary outcomes were algorithm sensitivity and specificity for postoperative event detection. RESULTS: A total of 56 patients undergoing cardiothoracic surgery met inclusion criteria, of which 24 (42.9%) underwent thoracic operations and 32 (57.1%) underwent cardiac operations. The median age was 62 (IQR: 51-68) years and 30 (53.6%) patients were female. The NightSignal algorithm detected 17 of the 21 postoperative events a median of 2 (IQR: 1-3) days prior to symptom onset, representing a sensitivity of 81%. The specificity, negative predictive value, and positive predictive value of the algorithm for the detection of postoperative events were 75%, 97%, and 28%, respectively. CONCLUSIONS: Machine learning analysis of biometric data collected from wearable devices has the potential to detect postoperative complications-prior to symptom onset-after cardiothoracic surgery.

Structures of VWF tubules before and after concatemerization reveal a mechanism of disulfide bond exchange.

von Willebrand factor (VWF) is an adhesive glycoprotein that circulates in the blood as disulfide-linked concatemers and functions in primary hemostasis. The loss of long VWF concatemers is associated with the excessive bleeding of type 2A von Willebrand disease (VWD). Formation of the disulfide bonds that concatemerize VWF requires VWF to self-associate into helical tubules, yet how the helical tubules template intermolecular disulfide bonds is not known. Here, we report electron cryomicroscopy (cryo-EM) structures of VWF tubules before and after intermolecular disulfide bond formation. The structures provide evidence that VWF tubulates through a charge-neutralization mechanism and that the A1 domain enhances tubule length by crosslinking successive helical turns. In addition, the structures reveal disulfide states before and after disulfide bond-mediated concatemerization. The structures and proposed assembly mechanism provide a foundation to rationalize VWD-causing mutations.

Single-cell transcriptomic heterogeneity between conduit and resistance mesenteric arteries in rats.

The endothelium contains morphologically similar cells throughout the vasculature, but individual cells along the length of a single vascular tree or in different regional circulations function dissimilarly. When observations made in large arteries are extrapolated to explain the function of endothelial cells (ECs) in the resistance vasculature, only a fraction of these observations are consistent between artery sizes. To what extent endothelial (EC) and vascular smooth muscle cells (VSMCs) from different arteriolar segments of the same tissue differ phenotypically at the single-cell level remains unknown. Therefore, single-cell RNA-seq (10x Genomics) was performed using a 10X Genomics Chromium system. Cells were enzymatically digested from large (>300 µm) and small (<150 µm) mesenteric arteries from nine adult male Sprague-Dawley rats, pooled to create six samples (3 rats/sample, 3 samples/group). After normalized integration, the dataset was scaled before unsupervised cell clustering and cluster visualization using UMAP plots. Differential gene expression analysis allowed us to infer the biological identity of different clusters. Our analysis revealed 630 and 641 differentially expressed genes (DEGs) between conduit and resistance arteries for ECs and VSMCs, respectively. Gene ontology analysis (GO-Biological Processes, GOBP) of scRNA-seq data discovered 562 and 270 pathways for ECs and VSMCs, respectively, that differed between large and small arteries. We identified eight and seven unique ECs and VSMCs subpopulations, respectively, with DEGs and pathways identified for each cluster. These results and this dataset allow the discovery and support of novel hypotheses needed to identify mechanisms that determine the phenotypic heterogeneity between conduit and resistance arteries.

Efficacy and Safety of Supraclavicular Thoracic Outlet Decompression.

OBJECTIVES: We aimed to report efficacy, safety, and health-related quality of life (HRQoL) outcomes of a multidisciplinary treatment approach including supraclavicular thoracic outlet decompression among patients with thoracic outlet syndrome (TOS). BACKGROUND: TOS is a challenging condition where controversy remains in diagnosis and treatment, primarily given a lack of data exploring various treatment approaches and associated patient outcomes. METHODS: Patients who underwent unilateral, supraclavicular thoracic outlet decompression, or pectoralis minor tenotomy for neurogenic, venous, or arterial TOS were identified from a prospectively maintained database. Demography, use of preoperative botulinum toxin injection, and participation in multidisciplinary evaluation were measured. The primary endpoints were composite postoperative morbidity and symptomatic improvement compared with baseline. RESULTS: Among 2869 patients evaluated (2007-2021), 1032 underwent surgery, including 864 (83.7%) supraclavicular decompressions and 168 (16.3%) isolated pectoralis minor tenotomies. Predominant TOS subtypes among surgical patients were neurogenic (75.4%) and venous TOS (23.4%). Most patients (92.9%) with nTOS underwent preoperative botulinum toxin injection; 56.3% reported symptomatic improvement. Before surgical consultation, few patients reported participation in physical therapy (10.9%). The median time from first evaluation to surgery was 136 days (interquartile range: 55, 258). Among 864 patients who underwent supraclavicular thoracic outlet decompression, complications occurred in 19.8%; the most common complication was chyle leak (8.3%). Four patients (0.4%) required revisional thoracic outlet decompression. At a median follow-up of 420 days (interquartile range: 150, 937) 93.3% reported symptomatic improvement. CONCLUSION: Based on low composite morbidity, need for very few revisional operations, and high rates of symptomatic improvement, a multidisciplinary treatment approach including primarily supraclavicular thoracic outlet decompression is safe and effective for patients with TOS.

Recreational cannabis legalization has had limited effects on a wide range of adult psychiatric and psychosocial outcomes.

BACKGROUND: The causal impacts of recreational cannabis legalization are not well understood due to the number of potential confounds. We sought to quantify possible causal effects of recreational cannabis legalization on substance use, substance use disorder, and psychosocial functioning, and whether vulnerable individuals are more susceptible to the effects of cannabis legalization than others. METHODS: We used a longitudinal, co-twin control design in 4043 twins (N = 240 pairs discordant on residence), first assessed in adolescence and now age 24-49, currently residing in states with different cannabis policies (40% resided in a recreationally legal state). We tested the effect of legalization on outcomes of interest and whether legalization interacts with established vulnerability factors (age, sex, or externalizing psychopathology). RESULTS: In the co-twin control design accounting for earlier cannabis frequency and alcohol use disorder (AUD) symptoms respectively, the twin living in a recreational state used cannabis on average more often (ßw = 0.11, p = 1.3 × 10-3), and had fewer AUD symptoms (ßw = -0.11, p = 6.7 × 10-3) than their co-twin living in an non-recreational state. Cannabis legalization was associated with no other adverse outcome in the co-twin design, including cannabis use disorder. No risk factor significantly interacted with legalization status to predict any outcome. CONCLUSIONS: Recreational legalization was associated with increased cannabis use and decreased AUD symptoms but was not associated with other maladaptations. These effects were maintained within twin pairs discordant for residence. Moreover, vulnerabilities to cannabis use were not exacerbated by the legal cannabis environment. Future research may investigate causal links between cannabis consumption and outcomes.

The association between saving disposition and financial distress: A genetically informed approach.

Saving disposition, the tendency to save rather than consume, has been found to be associated with economic outcomes. People lacking the disposition to save are more likely to experience financial distress. This association could be driven by other economic factors, behavioral traits, or even genetic effects. Using a sample of 3,920 American twins, we develop scales to measure saving disposition and financial distress. We find genetic influences on both traits, but also a large effect of the rearing family environment on saving disposition. We estimate that 44% of the covariance between the two traits is due to genetic effects. Saving disposition remains strongly associated with lower financial distress, even after controlling for family income, cognitive ability, and personality traits. The association persists within families and monozygotic twin pairs; the twin who saves more tends to be the twin who experiences less financial distress. This result suggest that there is a direct association between saving disposition and financial distress, although the direction of causation remains unclear.

Communication Planning for Cooperative Terrain-Based Underwater Localization.

This paper presents a decentralized communication planning algorithm for cooperative terrain-based navigation (dec-TBN) with autonomous underwater vehicles. The proposed algorithm uses forward simulation to approximate the value of communicating at each time step. The simulations are used to build a directed acyclic graph that can be searched to provide a minimum cost communication schedule. Simulations and field trials are used to validate the algorithm. The simulations use a real-world bathymetry map from Lake Nighthorse, CO, and a sensor model derived from an Ocean Server Iver2 vehicle. The simulation results show that the algorithm finds a communication schedule that reduces communication bandwidth by 86% and improves robot localization by up to 27% compared to non-cooperative terrain-based navigation. Field trials were conducted in Foster Reservoir, OR, using two Riptide Autonomous Solutions micro-unmanned underwater vehicles. The vehicles collected GPS, altimeter, acoustic communications, and dead reckoning data while following paths on the surface of the reservoir. The data were used to evaluate the planning algorithm. In three of four missions, the planning algorithm improved dec-TBN localization while reducing acoustic communication bandwidth by 56%. In the fourth mission, dec-TBN performed better when using full communications bandwidth, but the communication policy for that mission maintained 86% of the localization accuracy while using 9% of the communications. These results indicate that the presented communication planning algorithm can maintain or improve dec-TBN accuracy while reducing the number of communications used for localization.

Implementation of a Checklist to Reduce False-Positive Testing in Hospital-Acquired Clostridium Difficile Infection.

BACKGROUND: Clostridium difficile is a major pathogen responsible for nosocomial infectious diarrhea. After a spike in Clostridium difficile infection (CDI) cases, the focus team identified several cases of inappropriate sampling, i.e., asymptomatic patients being tested. We hypothesized that the inappropriate samples were leading to a high number of false-positive cases. We explored appropriate patient stool sampling as a strategy for reducing the number of asymptomatic cases in a 275-bed rural community hospital. METHODS: We conducted a prospective cohort study of inpatients to determine if appropriate stool sampling would result in a reduction in false positive Clostridium difficile cultures and decrease incidence of Clostridium difficile. We developed a checklist that would guide the nurse to improve the sampling process. RESULTS: The study implementation period ran from July through December 2016, with comparison to a control cohort in the prior six months. From Jan. 16 to May 15, the control group consisted of 461 inpatients, of which 89 tested positive for CDI 32.3 per 10,000 patient days. Of those 89 positive cases, 74 were identified as healthcare acquired infection (HAI) 26.8 per 10,000 patient days. Of these HAIs, 25 (33.8 percent) were inappropriate samples. In comparison, among the study period cohort of 277 inpatients, 46 inpatients tested positive for CDI 16.9 per 10,000 patient days, of which 26 were HAIs 9.5 per 10,000 patient days. During the study period, three samples (11.5 percent) were determined to be inappropriate. After the checklist implementation, the proportion of incorrect samples decreased from 33.8 percent to 11.5 percent. The number of HAI/patient days decreased form 0.024 percent to 0.08 percent. Similarly, the number of CDI/patient days also decreased from 0.295 percent to 0.15 percent. CONCLUSION: Implementation of a simple checklist prior to collection of stool sample proved to be effective in reducing the number of inappropriate samples sent for CDI testing, with a subsequent decrease in hospital acquired Clostridium difficile infections reported.

The creation and validation of the Developmental Emotional Faces Stimulus Set.

The Developmental Emotional Faces Stimulus Set (DEFSS) is designed to provide a standardized set of emotional stimuli that includes both child and adult faces and that has been validated by participants across a wide range of ages. This article describes the creation and validation of the DEFSS, which includes 404 validated facial photographs of people between 8 and 30 years old displaying five different emotional expressions: happy, angry, fearful, sad, and neutral. The emotions in all photographs were identified correctly by 86 % of the raters (minimum 55 %), and validity did not vary as a function of the age group of the model or of the raters, indicating that the pictures are equally appropriate for use across the entire age range. Strengths and limitations of the DEFSS are discussed.

Sulfate and thiosulfate inhibit oxalate transport via a dPrestin (Slc26a6)-dependent mechanism in an insect model of calcium oxalate nephrolithiasis.

Nephrolithiasis is one of the most common urinary tract disorders, with the majority of kidney stones composed of calcium oxalate (CaOx). Given its prevalence (US occurrence 10%), it is still poorly understood, lacking progress in identifying new therapies because of its complex etiology. Drosophila melanogaster (fruitfly) is a recently developed model of CaOx nephrolithiasis. Effects of sulfate and thiosulfate on crystal formation were investigated using the Drosophila model, as well as electrophysiological effects on both Drosophila (Slc26a5/6; dPrestin) and mouse (mSlc26a6) oxalate transporters utilizing the Xenopus laevis oocyte heterologous expression system. Results indicate that both transport thiosulfate with a much higher affinity than sulfate Additionally, both compounds were effective at decreasing CaOx crystallization when added to the diet. However, these results were not observed when compounds were applied to Malpighian tubules ex vivo. Neither compound affected CaOx crystallization in dPrestin knockdown animals, indicating a role for principal cell-specific dPrestin in luminal oxalate transport. Furthermore, thiosulfate has a higher affinity for dPrestin and mSlc26a6 compared with oxalate These data indicate that thiosulfate's ability to act as a competitive inhibitor of oxalate via dPrestin, can explain the decrease in CaOx crystallization seen in the presence of thiosulfate, but not sulfate. Overall, our findings predict that thiosulfate or oxalate-mimics may be effective as therapeutic competitive inhibitors of CaOx crystallization.

NIH Toolbox Cognition Battery (CB): validation of executive function measures in adults.

This study describes psychometric properties of the NIH Toolbox Cognition Battery (NIHTB-CB) executive function measures in an adult sample. The NIHTB-CB was designed for use in epidemiologic studies and clinical trials for ages 3 to 85. A total of 268 self-described healthy adults were recruited at four university-based sites, using stratified sampling guidelines to target demographic variability for age (20-85 years), gender, education and ethnicity. The NIHTB-CB contains two computer-based instruments assessing executive function: the Dimensional Change Card Sort (a measure of cognitive flexibility) and a flanker task (a measure of inhibitory control and selective attention). Participants completed the NIHTB-CB, corresponding gold standard convergent and discriminant measures, and sociodemographic questionnaires. A subset of participants (N=89) was retested 7 to 21 days later. Results reveal excellent sensitivity to age-related changes during adulthood, excellent test-retest reliability, and adequate to good convergent and discriminant validity. The NIH Toolbox EF measures can be used effectively in epidemiologic and clinical studies.

Associations between executive functions assessed in different contexts in a genetically informative sample.

Executive functions (EFs) are cognitive functions that help direct goal-related behavior. EFs are usually measured via behavioral tasks assessed in highly controlled laboratory settings under the supervision of a research assistant. Online versions of EF tasks are an increasingly popular alternative to in-lab testing. However, researchers do not have the same control over the testing environment during online EF assessments. To assess the extent to which EFs assessed in-lab and online are related, we used data from the Colorado Online Twin Study (CoTwins; 887 individual twins aged 13.98-19.05) and constructed an Lab Common EF factor and an Online Common EF factor from four EF tasks assessed in-lab and online. The Lab Common and Online Common EF factors were genetically identical (rA = 1.00) but phenotypically separable (r = .77, 95% confidence interval [0.59, 0.94]) indicating that these EF factors have the same genetic underpinnings but may be differentially influenced by environmental factors. We examined phenotypic, genetic, and environmental correlations between the EF factors and a general cognitive ability factor (g) assessed in the lab and found similar relationships between Lab Common EF and g and Online Common EF and g. Overall, these results suggest that Common EF factors assessed in different contexts are highly related to each other and similarly related to other cognitive outcomes. These findings indicate that online task-based EF assessments could be a viable strategy for increasing sample sizes in large-scale studies, particularly genetically informed studies. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Ciliopathy patient variants reveal organelle-specific functions for TUBB4B in axonemal microtubules.

Tubulin, one of the most abundant cytoskeletal building blocks, has numerous isotypes in metazoans encoded by different conserved genes. Whether these distinct isotypes form cell type- and context-specific microtubule structures is poorly understood. Based on a cohort of 12 patients with primary ciliary dyskinesia as well as mouse mutants, we identified and characterized variants in the TUBB4B isotype that specifically perturbed centriole and cilium biogenesis. Distinct TUBB4B variants differentially affected microtubule dynamics and cilia formation in a dominant-negative manner. Structure-function studies revealed that different TUBB4B variants disrupted distinct tubulin interfaces, thereby enabling stratification of patients into three classes of ciliopathic diseases. These findings show that specific tubulin isotypes have distinct and nonredundant subcellular functions and establish a link between tubulinopathies and ciliopathies.

II. NIH Toolbox Cognition Battery (CB): measuring executive function and attention.

In this chapter, we discuss two measures designed to assess executive function (EF) as part of the NIH Toolbox Cognition Battery (CB) and report pediatric data from the validation study. EF refers to the goal-directed cognitive control of thought, action, and emotion. Two measures were adapted for standardized computer administration: the Dimensional Change Card Sort (a measure of cognitive flexibility) and a flanker task (a measure of inhibitory control in the context of selective visual attention). Results reveal excellent developmental sensitivity across childhood, excellent reliability, and (in most cases) excellent convergent validity. Correlations between the new NIH Toolbox measures and age were higher for younger children (3-6 years) than for older children (8-15 years), and evidence of increasing differentiation of EF from other aspects of cognition (indexed by receptive vocabulary) was obtained.

Nanoparticle Strategies to Improve the Delivery of Anticancer Drugs across the Blood-Brain Barrier to Treat Brain Tumors.

Primary brain and central nervous system (CNS) tumors are a diverse group of neoplasms that occur within the brain and spinal cord. Although significant advances in our understanding of the intricate biological underpinnings of CNS neoplasm tumorigenesis and progression have been made, the translation of these discoveries into effective therapies has been stymied by the unique challenges presented by these tumors' exquisitely sensitive location and the body's own defense mechanisms (e.g., the brain-CSF barrier and blood-brain barrier), which normally protect the CNS from toxic insult. These barriers effectively prevent the delivery of therapeutics to the site of disease. To overcome these obstacles, new methods for therapeutic delivery are being developed, with one such approach being the utilization of nanoparticles. Here, we will cover the current state of the field with a particular focus on the challenges posed by the BBB, the different nanoparticle classes which are under development for targeted CNS tumor therapeutics delivery, and strategies which have been developed to bypass the BBB and enable effective therapeutics delivery to the site of disease.