Mis-spliced transcripts generate de novo proteins in TDP-43-related ALS/FTD.

Functional loss of TDP-43, an RNA binding protein genetically and pathologically linked to amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), leads to the inclusion of cryptic exons in hundreds of transcripts during disease. Cryptic exons can promote the degradation of affected transcripts, deleteriously altering cellular function through loss-of-function mechanisms. Here, we show that mRNA transcripts harboring cryptic exons generated de novo proteins in TDP-43-depleted human iPSC-derived neurons in vitro, and de novo peptides were found in cerebrospinal fluid (CSF) samples from patients with ALS or FTD. Using coordinated transcriptomic and proteomic studies of TDP-43-depleted human iPSC-derived neurons, we identified 65 peptides that mapped to 12 cryptic exons. Cryptic exons identified in TDP-43-depleted human iPSC-derived neurons were predictive of cryptic exons expressed in postmortem brain tissue from patients with TDP-43 proteinopathy. These cryptic exons produced transcript variants that generated de novo proteins. We found that the inclusion of cryptic peptide sequences in proteins altered their interactions with other proteins, thereby likely altering their function. Last, we showed that 18 de novo peptides across 13 genes were present in CSF samples from patients with ALS/FTD spectrum disorders. The demonstration of cryptic exon translation suggests new mechanisms for ALS/FTD pathophysiology downstream of TDP-43 dysfunction and may provide a potential strategy to assay TDP-43 function in patient CSF.

Extreme drought can deactivate ABA biosynthesis in embolism-resistant species.

The phytohormone abscisic acid (ABA) is synthesised by plants during drought to close stomata and regulate desiccation tolerance pathways. Conifers and some angiosperms with embolism-resistant xylem show a peaking-type (p-type) response in ABA levels, in which ABA levels increase early in drought then decrease as drought progresses, declining to pre-stressed levels. The mechanism behind this dynamic remains unknown. Here, we sought to characterise the mechanism driving p-type ABA dynamics in the conifer Callitris rhomboidea and the highly drought-resistant angiosperm Umbellularia californica. We measured leaf water potentials (Ψl ), stomatal conductance, ABA, conjugates and phaseic acid (PA) levels in potted plants during a prolonged but non-fatal drought. Both species displayed a p-type ABA dynamic during prolonged drought. In branches collected before and after the peak in endogenous ABA levels in planta, that were rehydrated overnight and then bench dried, ABA biosynthesis was deactivated beyond leaf turgor loss point. Considerable conversion of ABA to conjugates was found to occur during drought, but not catabolism to PA. The mechanism driving the decline in ABA levels in p-type species may be conserved across embolism-resistant seed plants and is mediated by sustained conjugation of ABA and the deactivation of ABA accumulation as Ψl becomes more negative than turgor loss.

Passive stomatal closure under extreme drought in an angiosperm species.

The phytohormone abscisic acid (ABA) plays a major role in closing the stomata of angiosperms. However, recent reports of some angiosperm species having a peaking-type ABA dynamic, in which under extreme drought ABA levels decline to pre-stressed levels, raises the possibility that passive stomatal closure by leaf water status alone can occur in species from this lineage. To test this hypothesis, we conducted instantaneous rehydration experiments in the peaking-type species Umbellularia californica through a long-term drought, in which ABA levels declined to pre-stress levels, yet stomata remain closed. We found that when ABA levels were lowest during extreme drought, stomata of U. californica were passively closed by leaf water status alone, with stomata reopening rapidly to maximum rates of gas exchange on instantaneous rehydration. This contrasts with leaves early in drought, in which ABA levels were highest and stomata did not reopen on instantaneous rehydration. The transition from ABA-driven stomatal closure to passively driven stomatal closure as drought progresses in this species occurs at very low water potentials facilitated by highly embolism-resistant xylem. These results have important implications for understanding stomatal control during drought in angiosperms.

Low temperature passivation of silicon surfaces for enhanced performance of Schottky-barrier MOSFET.

By using a simple device architecture along with a simple process design and a low thermal-budget of a maximum of 100 °C for passivating metal/semiconductor interfaces, a Schottky barrier MOSFET device with a low subthreshold slope of 70 mV dec-1could be developed. This device is enabled after passivation of the metal/silicon interface (found at the source/drain regions) with ultra-thin SiOxfilms, followed by the e-beam evaporation of high- quality aluminum and by using atomic-layer deposition for HfO2as a gate oxide. All of these fabrication steps were designed in a sequential process so that a gate-last recipe could minimize the defect density at the aluminum/silicon and HfO2/silicon interfaces, thus preserving the Schottky barrier height and ultimately, the outstanding performance of the transistor. This device is fully integrated into silicon after standard CMOS-compatible processing, so that it could be easily adopted into front-end-of-line or even in back-end-of-line stages of an integrated circuit, where low thermal budget is required and where its functionality could be increased by developing additional and fast logic.

Standardized Figures of Merit for Proper Benchmarking of Photocatalytic Inactivation of Bacteria Using Thin Films Based on TiO2 Nanostructures.

The study of photocatalysts fixed to surfaces for the inactivation of bacteria in wastewater has increased in recent years. However, there are no standardized methods to analyze the photocatalytic antibacterial activity of these materials, and no systematic studies have attempted to relate this activity to the number of reactive oxygen species generated during UV-light irradiation. Additionally, studies regarding photocatalytic antibacterial activity are usually carried out with varying pathogen concentrations, UV light doses, and catalyst amounts, making it difficult to compare results across different materials. The work introduces the photocatalytic bacteria inactivation efficiency (PBIE) and bacteria inactivation potential of hydroxyl radicals (BIPHR) figures of merit for evaluating the photocatalytic activity of catalysts fixed onto surfaces for bacteria inactivation. To demonstrate their applicability, these parameters are calculated for various photocatalytic TiO2 -based coatings, accounting for the catalyst area, the kinetic reaction rate constant associated with bacteria inactivation and hydroxyl radical formation, reactor volume, and UV light dose. This approach enables a comprehensive comparison of photocatalytic films prepared by different fabrication techniques and evaluated under diverse experimental conditions, with potential applications in the design of fixed-bed reactors.

Mis-spliced transcripts generate de novo proteins in TDP-43-related ALS/FTD.

Functional loss of TDP-43, an RNA-binding protein genetically and pathologically linked to ALS and FTD, leads to inclusion of cryptic exons in hundreds of transcripts during disease. Cryptic exons can promote degradation of affected transcripts, deleteriously altering cellular function through loss-of-function mechanisms. However, the possibility of de novo protein synthesis from cryptic exon transcripts has not been explored. Here, we show that mRNA transcripts harboring cryptic exons generate de novo proteins both in TDP-43 deficient cellular models and in disease. Using coordinated transcriptomic and proteomic studies of TDP-43 depleted iPSC-derived neurons, we identified numerous peptides that mapped to cryptic exons. Cryptic exons identified in iPSC models were highly predictive of cryptic exons expressed in brains of patients with TDP-43 proteinopathy, including cryptic transcripts that generated de novo proteins. We discovered that inclusion of cryptic peptide sequences in proteins altered their interactions with other proteins, thereby likely altering their function. Finally, we showed that these de novo peptides were present in CSF from patients with ALS. The demonstration of cryptic exon translation suggests new mechanisms for ALS pathophysiology downstream of TDP-43 dysfunction and may provide a strategy for novel biomarker development.

Transcranial electric stimulation motor evoked potentials for cervical spine intraoperative monitoring complications: systematic review and illustrative case of cardiac arrest.

PURPOSE: We show a systematic review of known complications during intraoperative neuromonitoring (IONM) using transcranial electric stimulation motor evoked potentials (TES-MEP) on cervical spine surgery, which provides a summary of the main findings. A rare complication during this procedure, cardiac arrest by cardioinhibitory reflex, is also described. METHODS: Findings of 523 scientific papers published from 1995 onwards were reviewed in the following databases: CENTRAL, Cochrane Library, Embase, Google Scholar, Ovid, LILACS, PubMed, and Web of Science. This study evaluated only complications on cervical spine surgery undergoing TES-MEP IONM. RESULTS: The review of the literature yielded 13 studies on the complications of TES-MEP IONM, from which three were excluded. Five studies are case series; the rest are case reports. Overall, 169 complications on 167 patients were reported in a total of 38,915 patients, a global prevalence of 0.43%. The most common complication was tongue-bite in 129 cases, (76.3% of all complication events). Tongue-bite had a prevalence of 0.33% (CI 95%, 0.28-0.39%) in all patients on TES-MEP IONM. A relatively low prevalence of severe complications was found: cardiac-arrhythmia, bradycardia and seizure, the prevalence of this complications represents only one case in all the sample. Alongside, we report the occurrence of cardiac arrest attributable to TES-MEP IONM. CONCLUSIONS: This systematic review shows that TES-MEP is a safe procedure with a very low prevalence of complications. To our best knowledge, asystole is reported for the first time as a complication during TES-MEP IONM.

TDP-43 loss and ALS-risk SNPs drive mis-splicing and depletion of UNC13A.

Variants of UNC13A, a critical gene for synapse function, increase the risk of amyotrophic lateral sclerosis and frontotemporal dementia1-3, two related neurodegenerative diseases defined by mislocalization of the RNA-binding protein TDP-434,5. Here we show that TDP-43 depletion induces robust inclusion of a cryptic exon in UNC13A, resulting in nonsense-mediated decay and loss of UNC13A protein. Two common intronic UNC13A polymorphisms strongly associated with amyotrophic lateral sclerosis and frontotemporal dementia risk overlap with TDP-43 binding sites. These polymorphisms potentiate cryptic exon inclusion, both in cultured cells and in brains and spinal cords from patients with these conditions. Our findings, which demonstrate a genetic link between loss of nuclear TDP-43 function and disease, reveal the mechanism by which UNC13A variants exacerbate the effects of decreased TDP-43 function. They further provide a promising therapeutic target for TDP-43 proteinopathies.

Abordaje de la vía aérea en el paciente neuroquirúrgico / Airway approach in the neurosurgical patient

Resumen: El abordaje de la vía aérea en el paciente neuroquirúrgico presenta grandes retos debido al escenario tan complejo al cual nos enfrentamos; debemos considerar las características propias del paciente, las comorbilidades presentes y la patología neurológica por la que va a ser intervenido. Conocer la patología neurológica y las implicaciones o repercusiones que ésta puede llegar a tener en el manejo de la vía aérea ayudarán a la toma de decisiones y conocer los retos y escenarios que se pudieran presentar durante el evento anestésico-quirúrgico.

Abstract: The approach to the airway in the neurosurgical patient presents great challenges due to the complex scenario we face; we must consider the patient's own characteristics, the co-morbidities present and the neurological pathology for which it is going to be intervened. Knowing the neurological pathology and the implications or repercussions that this may have over the management of the airway will help decision making and manage the challenges and scenarios that could arise during the anesthetic surgical event.

Hcfc1a regulates neural precursor proliferation and asxl1 expression in the developing brain.

BACKGROUND: Precise regulation of neural precursor cell (NPC) proliferation and differentiation is essential to ensure proper brain development and function. The HCFC1 gene encodes a transcriptional co-factor that regulates cell proliferation, and previous studies suggest that HCFC1 regulates NPC number and differentiation. However, the molecular mechanism underlying these cellular deficits has not been completely characterized. METHODS: Here we created a zebrafish harboring mutations in the hcfc1a gene (the hcfc1aco60/+ allele), one ortholog of HCFC1, and utilized immunohistochemistry and RNA-sequencing technology to understand the function of hcfc1a during neural development. RESULTS: The hcfc1aco60/+ allele results in an increased number of NPCs and increased expression of neuronal and glial markers. These neural developmental deficits are associated with larval hypomotility and the abnormal expression of asxl1, a polycomb transcription factor, which we identified as a downstream effector of hcfc1a. Inhibition of asxl1 activity and/or expression in larvae harboring the hcfc1aco60/+ allele completely restored the number of NPCs to normal levels. CONCLUSION: Collectively, our data demonstrate that hcfc1a regulates NPC number, NPC proliferation, motor behavior, and brain development.

Enhanced photocatalytic bacterial inactivation of atomic-layer deposited anatase-TiO2 thin films on rutile-TiO2 nanotubes.

In this work, experimental conditions were established to fabricate self-ordered rutile-TiO2 nanotube arrays, coated with a conformal anatase-TiO2 thin layer using atomic layer deposition. E. coli inactivation tests showed a considerable increase in photocatalytic activity using rutile-TiO2 nanotubes coated with anatase-TiO2 compared to that using single rutile or anatase TiO2 nanotubes only. Photocatalytic hydroxyl radical generation rates (determined by pNDA bleaching) were also meaningfully enhanced for the combined anatase/rutile TiO2 nanostructures. Therefore, we show that it is possible to take advantage of the morphological properties of the materials and the synergic effect from the combination of both TiO2 polymorphs during the design of novel materials, which could be used as antibacterial agents to improve the quality of drinking water.

Phenotypic Plasticity of Invasive Edge Glioma Stem-like Cells in Response to Ionizing Radiation.

Unresectable glioblastoma (GBM) cells in the invading tumor edge can act as seeds for recurrence. The molecular and phenotypic properties of these cells remain elusive. Here, we report that the invading edge and tumor core have two distinct types of glioma stem-like cells (GSCs) that resemble proneural (PN) and mesenchymal (MES) subtypes, respectively. Upon exposure to ionizing radiation (IR), GSCs, initially enriched for a CD133+ PN signature, transition to a CD109+ MES subtype in a C/EBP-ß-dependent manner. Our gene expression analysis of paired cohorts of patients with primary and recurrent GBMs identified a CD133-to-CD109 shift in tumors with an MES recurrence. Patient-derived CD133-/CD109+ cells are highly enriched with clonogenic, tumor-initiating, and radiation-resistant properties, and silencing CD109 significantly inhibits these phenotypes. We also report a conserved regulation of YAP/TAZ pathways by CD109 that could be a therapeutic target in GBM.

Retention of pediatric resuscitation performance after a simulation-based mastery learning session: a multicenter randomized trial.

OBJECTIVES: Using simulation-based mastery learning, residents can be trained to achieve a predefined performance standard in resuscitation. After mastery is achieved, performance degradation occurs over time. Prior investigations have shown performance retention of 12-14 months following intensive simulation-based mastery learning sessions. We sought to investigate the duration of mastery-level resuscitation performance retention after a single 1- to 2-hour simulation-based mastery learning session. DESIGN: Randomized, prospective trial. SETTING: Medical simulation laboratory. SUBJECTS: Convenience sample of 42 pediatric residents. INTERVENTIONS: Baseline resuscitation performance was determined on four standardized simulation scenarios. After determination of baseline performance, each resident repeated each scenario, as needed, until mastery-level performance was achieved. Residents were then randomized and retested 2, 4, or 6 months later. Statistical analysis on scores at baseline and retesting were used to determine performances changes from baseline and performance retention over time. MEASUREMENTS AND MAIN RESULTS: Forty-two residents participated in the study (12 in 2 mo group, 14 in 4 mo group, and 16 in 6 mo group). At baseline, postgraduate year-3 residents performed better than postgraduate year-1 residents (p = 0.003). Overall performance on each of the four scenarios improved at retesting. The percent of residents maintaining mastery-level performance showed a significant linear decline (p = 0.039), with a drop at each retesting interval; 92% retained mastery at 2 months, 71% at 4 months, and 56% at 6 months. There was no difference in retention between postgraduate year-1, postgraduate year-2, and postgraduate year-3 residents (p = 0.14). CONCLUSIONS: Residents displayed significant improvements in resuscitation performance after a single simulation-based mastery learning session, but performance declined over time, with less than 60% retaining mastery-level performance at 6 months. Our results suggest that relatively frequent refresher training is needed after a single simulation-based mastery learning session. Additional research is needed to determine the duration of performance retention following any specific simulation-based mastery learning intervention.

Effect of electric field treatment on unsaturated fatty acid in crude avocado oil.

The objective of this study was to evaluate the stability of the fatty acids in avocado oil when the product is subjected to different conditions of electric field treatment (voltage: 5 kV cm(-1); frequency: 720 Hz; treatment time: 5, 10, 15, 20, and 25 min). Fatty acids were analyzed by Fourier transform infrared spectroscopy in the mid-infrared region. Electric field is a suitable method to preserve the oil quality and composition with minimal modifications in unsaturated fatty acids.

Femoral central venous catheters are not associated with higher rates of infection in the pediatric critical care population.

BACKGROUND: Adult data show a difference in central venous catheter (CVC) infection rates between 3 major sites: subclavian (SC), internal jugular (IJ), and femoral veins. We hypothesized that in patients in pediatric intensive care units (PICUs), there is no difference in rates of CVC infection among these three sites, but specifically the femoral compared to all other sites. METHODS: In this retrospective cohort study, data from January 1999 to January 2008 were collected prospectively for internal review and quality assurance. All PICU patients with a CVC were enrolled. The rate of CVC infection was determined using Cox regression survival analysis to account for various durations of CVC placement at the various sites, then adjusted for severity of illness, number of lumens, and patient age. Mortality was compared in patients with a CVC infection versus those without. RESULTS: A total of 4,512 patients with a CVC were enrolled. No site was associated with an increased risk of infection compared with the other sites, with hazard ratios of 0.951 (95% confidence interval [CI], 0.612-1.478) for the SC site, 0.956 (95% CI, 0.593-1.541) for the IJ site, and 1.120 (95% CI, 0.753-1.665) for the femoral site. No significant association between mortality and presence of CVC infection was found when adjusted for age, severity of illness, and duration of CVC placement. An association was found between the presence of a CVC infection and prolonged PICU length of stay (3.98 days longer; P < .001). CONCLUSION: Femoral CVCs are not associated with higher rates of infection in the PICU. In addition, the presence of CVC infection does not affect mortality, but is associated with longer PICU admission.

Modeling hospital response to mild and severe influenza pandemic scenarios under normal and expanded capacities.

William Beaumont Army Medical Center conducted quantitative modeling with FluSurge 2.0 (Centers for Disease Control and Prevention) to determine hospital capabilities in responding to patient arrival surges of the Fort Bliss population in mild 1968-type and severe 1918-type influenza pandemics. Model predictions showed that William Beaumont Army Medical Center could adequately care for all intensive care unit (ICU) and non-ICU patients during a mild pandemic, particularly if hospital capacity was expanded using the emergency management plan, excess surge plan, or activation of a contagious disease outbreak facility. For a severe influenza pandemic, model predictions showed that hospital beds, ventilators, and other resources would be exceeded within 2 or 3 weeks. Even at maximal hospital expansion, for a 12-week severe pandemic with a 35% attack rate there would be peak demand for 214% of available non-ICU beds, 785% of ICU beds, and 392% of ventilators. Health care planners and decision-makers should prepare for resource challenges when developing plans for the next influenza pandemic.