High-content RNAi screening identifies the Type 1 inositol triphosphate receptor as a modifier of TDP-43 localization and neurotoxicity.

Cytosolic aggregation of the nuclear RNA-binding protein (RBP) TDP-43 (43 kDa TAR DNA-binding domain protein) is a suspected direct or indirect cause of motor neuron deterioration in amyotrophic lateral sclerosis (ALS). In this study, we implemented a high-content, genome-wide RNAi screen to identify pathways controlling TDP-43 nucleocytoplasmic shuttling. We identified ∼60 genes whose silencing increased the cytosolic localization of TDP-43, including nuclear pore complex components and regulators of G2/M cell cycle transition. In addition, we identified the type 1 inositol-1,4,5-trisphosphate (IP3) receptor (ITPR1), an IP3-gated, endoplasmic reticulum (ER)-resident Ca(2+) channel, as a strong modulator of TDP-43 nucleocytoplasmic shuttling. Knockdown or chemical inhibition of ITPR1 induced TDP-43 nuclear export in immortalized cells and primary neurons and strongly potentiated the recruitment of TDP-43 to Ubiquilin-positive autophagosomes, suggesting that diminished ITPR1 function leads to autophagosomal clearance of TDP-43. The functional significance of the TDP-43-ITPR1 genetic interaction was tested in Drosophila, where mutant alleles of ITPR1 were found to significantly extended lifespan and mobility of flies expressing TDP-43 under a motor neuron driver. These combined findings implicate IP3-gated Ca(2+) as a key regulator of TDP-43 nucleoplasmic shuttling and proteostasis and suggest pharmacologic inhibition of ITPR1 as a strategy to combat TDP-43-induced neurodegeneration in vivo.

Predictors of Abnormal Renal Ultrasonography in Children With Urinary Tract Infection.

BACKGROUND AND OBJECTIVES: The 2011 American Academy of Pediatrics guidelines recommended a renal and bladder ultrasound (RBUS) after the first febrile urinary tract infection (UTI) in infants. Abnormal RBUS findings may be due to inflammation from the acute UTI or from vesicoureteral reflux (VUR), which may require a voiding cystourethrogram (VCUG) to diagnose, increasing health care costs. Our objective was to evaluate the effect of timing of imaging relative to the acute illness on abnormal dilation on RBUS and VCUG findings. METHODS: Multicenter, retrospective study of patients aged 2 to 24 months presenting with first UTI and RBUS from January 1, 2015, to December 31, 2019. Demographics, isolated pathogen, and timing of RBUS and VCUG relative to urine culture date were recorded and compared. RESULTS: A total of 227 patients were included. On multivariable logistic regression, increased time in days to RBUS was associated with decreased odds of abnormal dilation (adjusted odds ratio, 0.980; P = .018) in those patients meeting culture criteria for UTI (for each additional day of delay in obtaining RBUS, the adjusted odds of detecting dilation decreased by ∼2%). There was no significant association between timing of imaging and VUR on VCUG. Additionally, 32% of patients underwent RBUS who did not meet UTI culture criteria but had similar rates of abnormal dilation and VUR to those meeting UTI culture criteria. CONCLUSIONS: Increased time to RBUS led to decreased odds of abnormal dilation, suggesting that delaying RBUS may lead to fewer false-positive results, which may limit unnecessary additional testing and reduce health care costs. Additionally, a significant number of patients who did not meet UTI culture criteria underwent RBUS but had similar results to those meeting criteria, suggesting that the previous colony-forming unit definition for UTI may be suboptimal.

Safety of Non-Operating Room Anesthesia With Propofol Sedation in Three Pediatric Patients With Central Sleep Apnea.

Children with central sleep apnea may require sedation for procedures, including brain imaging as part of the evaluation of apnea. However, the safety of deep sedation without a protected airway is not known in this patient population. In this case series, we present 3 children with central sleep apnea who were sedated with propofol for brain imaging in a non-operating room setting. All 3 did well with no complications; those with a home oxygen requirement were on oxygen during the procedure but none experienced apnea, desaturation, or respiratory distress. While obstructive sleep apnea is a known contraindication to deep sedation with propofol, it may be safe in pediatric patients with central sleep apnea. Deep sedation may be a good option for these patients, thereby avoiding the need for general anesthesia and placement of an advanced airway.

Ubiquilin modifies TDP-43 toxicity in a Drosophila model of amyotrophic lateral sclerosis (ALS).

TDP-43 (43-kDa TAR DNA-binding protein) is a major constituent of ubiquitin-positive cytosolic aggregates present in neurons of patients with amyotrophic lateral sclerosis (ALS) and ubiquitin-positive fronto-temporal lobar degeneration (FTLD-U). Inherited mutations in TDP-43 have been linked to familial forms of ALS, indicating a key role for TDP-43 in disease pathogenesis. Here, we describe a Drosophila melanogaster model of TDP-43 proteinopathy. Expression of wild-type human TDP-43 protein in Drosophila motor neurons led to motor dysfunction and dramatic reduction of life span. Interestingly, coexpression of ubiquilin 1, a previously identified TDP-43-interacting protein with suspected functions in autophagy and proteasome targeting, reduced steady-state TDP-43 expression but enhanced the severity of TDP-43 phenotypes. Finally, ectopically expressed TDP-43 was largely localized to motor neuron nuclei, suggesting that expression of wild-type TDP-43 alone is detrimental even in the absence of cytosolic aggregation. Our findings demonstrate that TDP-43 exerts cell-autonomous neurotoxicity in Drosophila and further imply that dose-dependent alterations of TDP-43 nuclear function may underlie motor neuron death in ALS.

Characteristics and Outcomes of Patients Receiving Sedation for Voiding Cystourethrography.

Background Voiding cystourethrography (VCUG) is used to diagnose vesicoureteral reflux (VUR); however, it is an invasive procedure and can be psychologically distressing. Procedural sedation is occasionally utilized to alleviate anxiety during VCUG, and some patient populations may get referred more readily for sedation than others. Sedative medications may also impact the results of the test due to their effects on smooth muscle. The goals of this study were to compare patient characteristics between those that were referred for procedural sedation and those that were not and to compare VCUG results between sedated and non-sedated patients. Methodology We performed a retrospective cohort study of patients aged 2-18 years undergoing VCUG during a five-year period. Sedated patients were matched with non-sedated patients controlling for referring provider and procedure year. Exclusion criteria included chronic catheterization, same-day surgery, current intensive care admission, and sedation restrictions. A total of 284 patients were included. Demographic information, medical comorbidities, and VCUG results were analyzed. Results There were no significant differences between sedated and non-sedated patients in any demographic variables. Neurologic, developmental, and gastrointestinal comorbidities were more common in sedated patients. On multivariate analysis, having more than one comorbid condition was the only significant predictor of referral for procedural sedation. There were no significant differences in VCUG results between sedated and non-sedated patients. Conclusions Patients with comorbidities were more likely to receive procedural sedation for VCUG. Procedural sedation did not have a significant impact on test results, suggesting its potential utility in relieving pain and anxiety associated with VCUG.

In-hospital perforation risk in acute appendicitis: Age matters.

BACKGROUND: Controversy exists regarding how quickly an adult with appendicitis requires surgery to prevent perforation, and recent literature on antibiotic use as definitive treatment has complicated this question further. Since perforation is associated with worse outcomes, particularly in the elderly, efforts to prevent this complication are warranted. We studied risk factors for in-hospital perforation in patients diagnosed by admission CT with non-perforated acute appendicitis. METHODS: We evaluated baseline demographics, symptom duration, and time from admission to antibiotics and surgery. Outcome measure was perforation diagnosed intra-operatively by attending surgeon. RESULTS: Of 700 patients, 84 (12%) sustained in-hospital perforation; time from admission to operation or antibiotics were not associated. Duration of symptoms >24 h (aOR = 2.23, 95% CI = 1.33-3.72, p < 0.001) increased perforation risk. Patient age over 46 years (aOR = 4.54, 95% CI = 2.04-10.06, p < 0.001) was also associated with higher risk that increased with increasing age. CONCLUSION: Time to operation and antibiotic timing were not associated with in-hospital perforation in a general adult population. However, these findings suggest a possible benefit to expedient surgery in older patients.

Association between Foramen Size and Febrile Seizure Status in the Pediatric Population: A Two-Center Retrospective Analysis.

Objective Febrile seizures have been shown to occur in 2 to 5% of children between the ages of 6 months and 5 years, making them the most common seizures of childhood. Multiple risk factors for febrile seizures have been identified; however, no investigation has been conducted to explore foramen size and associated venous drainage as a potential risk factor for experiencing febrile seizures. Of particular interest are the parietal foramen and the condylar canal, which conduct the parietal emissary vein and the occipital emissary vein, respectively. Emissary veins lack valves, allowing them to play a crucial role in selective brain cooling via a bidirectional flow of blood from the head's evaporating surface. Narrowed cranial apertures conducting these veins may lead to reduced cerebral venous outflow and delayed brain cooling, creating favorable conditions for a febrile event. This study seeks to explore the association between cranial aperture area and febrile seizure status. Methods A retrospective cross-sectional medical record review study from January 2011 to December 2017 was conducted at a 500-bed academic hospital and a 977-bed private hospital in Lubbock, Texas, United States. A total of 101 complex febrile seizure patients were compared with a similarly aged group of 75 trauma patients representing the normal population. Parietal foramen area and condylar canal area were electronically measured and defined as having "normal" or "below normal" area. Statistical Analysis Independent t -tests were used to compare foramen and canal areas by febrile seizure status. Logistic regression analyses were conducted to determine the association of small cranial aperture area with febrile seizure status. Results Below normal parietal foramen area had a strong association with febrile seizures in our patient population. Male sex, white race, and complete vaccination status were also found to have significant associations with febrile seizure status. Conclusion Our findings indicated that narrowed parietal foramen may be considered as a risk factor for febrile seizure development.

Profile of Data Sharing in the Clinical Neurosciences.

IMPORTANCE:  In today's climate of high healthcare costs and limited research resources, much attention has been given to inefficiency in research. Open access to research data has been proposed as a way to pool resources and make the most of research funding while also promoting transparency and scientific rigor.  Objective: The clinical neurosciences stand to benefit greatly from the potential opportunities afforded by open data, and we sought to evaluate the current state of publicly available research findings and data sharing policies within the clinical neurosciences.  Design: The Clarivate Analytics Web of Science journal citation reports for 2017 were used to sort journals in the category 'Clinical Neurosciences' by impact factor. The top 50 journals were selected and reviewed, but data was only collected from journals focused on original research (42/50). For each journal we reviewed the 10 most recent original research articles for 2016, 2017, and 2018 as designated by Scopus.  Results: A data sharing policy existed for 60% (25/42) of the journals reviewed. Of the articles studied 41% (517/1255) contained source data, and the amount of articles with available source data increased from 2016 to 2018. Of all the articles reviewed, 49.4% (620/1255) were open access. Overall, 6.9% (87/1255) of articles had their source data accessible outside of the manuscript (e.g. registries, databases, etc.) and 8.9% (112/1255) addressed the availability of their source data within the publication itself. The availability of source data outside the manuscript and in-article discussion of source data availability both increased from 2016 to 2018. Only 3.9% (49/1255) of articles reviewed reported negative results for their primary outcome, and 7.6% (95/1255) of the articles could not be defined as primarily reporting positive or negative findings (characterization studies, census reporting, etc.). The distribution of negative versus positive results reported showed no significant trend over the years studied.  Conclusion and Relevance: Our results demonstrate an opportunity for increased data sharing in neuroscience original research. These findings also suggest a trend towards increased adoption of open data sharing policies among journals and increased availability of unprocessed data in publications. This can increase the quality and speed at which new research is developed in the clinical neurosciences.

Child Abuse and Deformational Plagiocephaly in a West Texas Hospital System.

Background The aim of this study was to assess deformational plagiocephaly's (DP) predictive value in neglect and physical abuse (nonaccidental trauma [NAT]) within the pediatric population. In addition, we sought to characterize the prevalence of DP and NAT for our hospital's mostly rural catchment area. Methods Data on hospitalized patients diagnosed with NAT and/or neglect between 2012 and 2018 were collected via retrospective chart review. All enrolled children were younger than the age of 4 years at the time of diagnosis, and those without legible head computed tomographies or magnetic resonance images during their initial hospitalization were excluded. Utilizing neuroimaging, we calculated the cranial vault asymmetry index (CVAI) and cranial index for each patient to assess for DP. Differences between the two groups were assessed using Wilcoxon's rank-sum test for continuous variables and Fisher's exact test for categorical variables. A p -value of 0.05 or less was considered statistically significant. All analyses were conducted using SAS 9.4 (Cary, North Carolina, United States). Results The prevalence of DP within the combined cohort of NAT and neglect patients is 21%, similar to that reported in the literature for the general population (20-50%). There was no significance between the prevalence of DP and a history of NAT ( p > 0.1) or neglect ( p > 0.1). Furthermore, there was no correlation between CVAI and characteristics of initial presentation or history of trauma for either NAT ( p -values: 0.359 and 0.250, respectively) or neglect groups ( p -values: 0.116 and 0.770, respectively). Conclusion While there are many limitations to this study, our results suggest that abused children are no more likely to have history of DP than the general population, and the degree of DP is not associated with severity of trauma history or initial presentation. We hope the results of this study promote future investigations for unique and subtle predictive factors of child abuse/neglect.

Contrast-Induced Vomiting in Pediatric Patients Under Propofol Sedation: A Case Series.

Gadolinium-based compounds are frequently used in contrast-enhanced magnetic resonance imaging studies. Rarely, adverse events have been reported with administration of these compounds, of which the most common are nausea and vomiting. Although well established in the adult literature, these adverse effects are less well described in the pediatric population, who often need sedation to complete imaging studies. In this case series, we present 3 children who experienced vomiting shortly after contrast administration while under sedation with propofol, which is known to have antiemetic properties. Although all 3 children recovered without complication, this case series illustrates the serious potential consequences of vomiting while sedated, and providers should be aware of these possible adverse events as pediatric sedation becomes more common outside the operating room.

Data Sharing in Neurosurgery and Neurology Journals.

In this era of high health care cost and limited research resources, open access to de-identified clinical research study data may promote increased scientific transparency and rigor, allow for the combination and re-analysis of similar data sets, and decrease un-necessary replication of unpublished negative studies. Driven by expanded computing capabilities, advocacy for data sharing to maximize research value is growing in both translational and clinical research communities. The focus of this study is to report on the current status of publicly available research data from studies published in the top 40 neurology and neurosurgery clinical research journals by impact factor. The top journals were carefully reviewed for data sharing policies. Of the journals with data sharing policies, the 10 most current original research papers from December 2015 - February 2016 were reviewed for data sharing statements and data availability. A data sharing policy existed for 48% (19/40) of the 40 journals investigated. Of the 19 journals with an existing data sharing policy, 58% (11/19) of the policies stated that data should be made available to interested parties upon request and 21% (4/19) of these journals encouraged authors to provide a data sharing statement in the article of what data would be available upon request. Of the 190 articles reviewed for data availability, 21% (40/190) of these articles included some source data in the results, figures, or supplementary sections. This evaluation highlights opportunities for neurology and neurosurgery investigators and journals to improve access to study data and even publish the data prospectively for the betterment of clinical outcome analysis and patient care.

Identification of genetic modifiers of TDP-43 neurotoxicity in Drosophila.

Cytosolic aggregation of the nuclear RNA-binding protein TDP-43 is a histopathologic signature of degenerating neurons in amyotrophic lateral sclerosis (ALS), and mutations in the TARDBP gene encoding TDP-43 cause dominantly inherited forms of this condition. To understand the relationship between TDP-43 misregulation and neurotoxicity, we and others have used Drosophila as a model system, in which overexpression of either wild-type TDP-43 or its ALS-associated mutants in neurons is sufficient to induce neurotoxicity, paralysis, and early death. Using microarrays, we have examined gene expression patterns that accompany TDP-43-induced neurotoxicity in the fly system. Constitutive expression of TDP-43 in the Drosophila compound eye elicited widespread gene expression changes, with strong upregulation of cell cycle regulatory genes and genes functioning in the Notch intercellular communication pathway. Inducible expression of TDP-43 specifically in neurons elicited significant expression differences in a more restricted set of genes. Genes that were upregulated in both paradigms included SpindleB and the Notch target Hey, which appeared to be a direct TDP-43 target. Mutations that diminished activity of Notch or disrupted the function of downstream Notch target genes extended the lifespan of TDP-43 transgenic flies, suggesting that Notch activation was deleterious in this model. Finally, we showed that mutation of the nucleoporin Nup50 increased the lifespan of TDP-43 transgenic flies, suggesting that nuclear events contribute to TDP-43-dependent neurotoxicity. The combined findings identified pathways whose deregulation might contribute to TDP-43-induced neurotoxicity in Drosophila.

The Drosophila BTB domain protein Jim Lovell has roles in multiple larval and adult behaviors.

Innate behaviors have their origins in the specification of neural fates during development. Within Drosophila, BTB (Bric-a-brac,Tramtrack, Broad) domain proteins such as Fruitless are known to play key roles in the neural differentiation underlying such responses. We previously identified a gene, which we have termed jim lovell (lov), encoding a BTB protein with a role in gravity responses. To understand more fully the behavioral roles of this gene we have investigated its function through several approaches. Transcript and protein expression patterns have been examined and behavioral phenotypes of new lov mutations have been characterized. Lov is a nuclear protein, suggesting a role as a transcriptional regulator, as for other BTB proteins. In late embryogenesis, Lov is expressed in many CNS and PNS neurons. An examination of the PNS expression indicates that lov functions in the late specification of several classes of sensory neurons. In particular, only two of the five abdominal lateral chordotonal neurons express Lov, predicting functional variation within this highly similar group. Surprisingly, Lov is also expressed very early in embryogenesis in ways that suggests roles in morphogenetic movements, amnioserosa function and head neurogenesis. The phenotypes of two new lov mutations that delete adjacent non-coding DNA regions are strikingly different suggesting removal of different regulatory elements. In lov(47) , Lov expression is lost in many embryonic neurons including the two lateral chordotonal neurons. lov(47) mutant larvae show feeding and locomotor defects including spontaneous backward movement. Adult lov(47) males perform aberrant courtship behavior distinguished by courtship displays that are not directed at the female. lov(47) adults also show more defective negative gravitaxis than the previously isolated lov(91Y) mutant. In contrast, lov(66) produces largely normal behavior but severe female sterility associated with ectopic lov expression in the ovary. We propose a negative regulatory role for the DNA deleted in lov(66) .

RNA-binding proteins in neurodegenerative disease: TDP-43 and beyond.

Neurodegenerative diseases are a diverse group of disorders that affect different neuron populations, differ in onset and severity, and can be either inherited or sporadic. One common pathological feature of most of these diseases is the presence of insoluble inclusions in and around neurons, which largely consist of misfolded and aggregated protein. For this reason, neurodegenerative diseases are typically thought to be disorders of aberrant protein processing, in which the cumulative effects of misfolded protein aggregates overwhelm the neuron's proteostatic capacity. However, a growing body of evidence suggests a role for abnormal RNA processing in neurodegenerative disease. The importance of RNA metabolism in disease was highlighted by the discovery of TDP-43 (TAR DNA-binding protein of 43 kDa), an RNA-binding protein (RBP), as a primary component of insoluble aggregates in patients with sporadic amyotrophic lateral sclerosis (ALS). Subsequently, inherited mutations in TDP-43 and the structurally related RBP, FUS/TLS (fused in sarcoma/translated in liposarcoma), were found to cause ALS. These exciting findings have ushered in a new era of ALS research in which the deregulation of RNA metabolism is viewed as a central cause of motor neuron deterioration. In addition, the fact that neuropathologically and anatomically distinct neurodegenerative diseases display altered RNA metabolism suggests that common pathologic mechanisms may underlie many of these disorders.

Potentiation of amyotrophic lateral sclerosis (ALS)-associated TDP-43 aggregation by the proteasome-targeting factor, ubiquilin 1.

TDP-43 (43-kDa TAR DNA-binding domain protein) is a major constituent of ubiquitin-positive cytoplasmic aggregates present in neurons of patients with fronto-temporal lobular dementia and amyotrophic lateral sclerosis (ALS). The pathologic significance of TDP-43 aggregation is not known; however, dominant mutations in TDP-43 cause a subset of ALS cases, suggesting that misfolding and/or altered trafficking of TDP-43 is relevant to the disease process. Here, we show that the presenilin-binding protein ubiquilin 1 (UBQLN) plays a role in TDP-43 aggregation. TDP-43 interacted with UBQLN both in yeast and in vitro, and the carboxyl-terminal ubiquitin-associated domain of UBQLN was both necessary and sufficient for binding to polyubiquitylated forms of TDP-43. Overexpression of UBQLN recruited TDP-43 to detergent-resistant cytoplasmic aggregates that colocalized with the autophagosomal marker, LC3. UBQLN-dependent aggregation required the UBQLN UBA domain, was mediated by non-overlapping regions of TDP-43, and was abrogated by a mutation in UBQLN previously linked to Alzheimer disease. Four ALS-associated alleles of TDP-43 also coaggregated with UBQLN, and the extent of aggregation correlated with in vitro UBQLN binding affinity. Our findings suggest that UBQLN is a polyubiquitin-TDP-43 cochaperone that mediates the autophagosomal delivery and/or proteasome targeting of TDP-43 aggregates.