Recovery kinetics of dual AAV-mediated human otoferlin expression.

Deafness-causing deficiencies in otoferlin (OTOF) have been addressed preclinically using dual adeno-associated virus (AAV)-based approaches. However, timing of transduction, recombination of mRNA, and protein expression with dual hybrid AAV methods methods have not previously been characterized. Here, we have established an ex vivo assay to determine the kinetics of dual-AAV mediated expression of OTOF in hair cells of the mouse utricle. We utilized two different recombinant vectors that comprise DB-OTO, one containing the 5' portion of OTOF under the control of the hair cell-specific Myo15 promoter, and the other the 3' portion of OTOF. We explored specificity of the Myo15 promoter in hair cells of the mouse utricle, established dose response characteristics of DB-OTO ex vivo in an OTOF-deficient mouse model, and demonstrated tolerability of AAV1 in utricular hair cells. Furthermore, we established deviations from a one-to-one ratio of 5' to 3' vectors with little impact on recombined OTOF. Finally, we established a plateau in quantity of recombined OTOF mRNA and protein expression by 14 to 21 days ex vivo with comparable recovery timing to that in vivo model. These findings demonstrate the utility of an ex vivo model system for exploring expression kinetics and establish in vivo and ex vivo recovery timing of dual AAV-mediated OTOF expression.

Early versus Later Anticoagulation for Stroke with Atrial Fibrillation.

BACKGROUND: The effect of early as compared with later initiation of direct oral anticoagulants (DOACs) in persons with atrial fibrillation who have had an acute ischemic stroke is unclear. METHODS: We performed an investigator-initiated, open-label trial at 103 sites in 15 countries. Participants were randomly assigned in a 1:1 ratio to early anticoagulation (within 48 hours after a minor or moderate stroke or on day 6 or 7 after a major stroke) or later anticoagulation (day 3 or 4 after a minor stroke, day 6 or 7 after a moderate stroke, or day 12, 13, or 14 after a major stroke). Assessors were unaware of the trial-group assignments. The primary outcome was a composite of recurrent ischemic stroke, systemic embolism, major extracranial bleeding, symptomatic intracranial hemorrhage, or vascular death within 30 days after randomization. Secondary outcomes included the components of the composite primary outcome at 30 and 90 days. RESULTS: Of 2013 participants (37% with minor stroke, 40% with moderate stroke, and 23% with major stroke), 1006 were assigned to early anticoagulation and 1007 to later anticoagulation. A primary-outcome event occurred in 29 participants (2.9%) in the early-treatment group and 41 participants (4.1%) in the later-treatment group (risk difference, -1.18 percentage points; 95% confidence interval [CI], -2.84 to 0.47) by 30 days. Recurrent ischemic stroke occurred in 14 participants (1.4%) in the early-treatment group and 25 participants (2.5%) in the later-treatment group (odds ratio, 0.57; 95% CI, 0.29 to 1.07) by 30 days and in 18 participants (1.9%) and 30 participants (3.1%), respectively, by 90 days (odds ratio, 0.60; 95% CI, 0.33 to 1.06). Symptomatic intracranial hemorrhage occurred in 2 participants (0.2%) in both groups by 30 days. CONCLUSIONS: In this trial, the incidence of recurrent ischemic stroke, systemic embolism, major extracranial bleeding, symptomatic intracranial hemorrhage, or vascular death at 30 days was estimated to range from 2.8 percentage points lower to 0.5 percentage points higher (based on the 95% confidence interval) with early than with later use of DOACs. (Funded by the Swiss National Science Foundation and others; ELAN ClinicalTrials.gov number, NCT03148457.).

Specialist Perspectives on the Imaging Selection of Large Vessel Occlusion in the Late Window.

BACKGROUND: The proper imaging modality for use in the selection of patients for endovascular thrombectomy (EVT) presenting in the late window remains controversial, despite current guidelines advocating the use of advanced imaging in this population. We sought to understand if clinicians with different specialty training differ in their approach to patient selection for EVT in the late time window. METHODS: We conducted an international survey of stroke and neurointerventional clinicians between January and May 2022 with questions focusing on imaging and treatment decisions of large vessel occlusion (LVO) patients presenting in the late window. Interventional neurologists, interventional neuroradiologists, and endovascular neurosurgeons were defined as interventionists whereas all other specialties were defined as non-interventionists. The non-interventionist group was defined by all other specialties of the respondents: stroke neurologist, neuroradiologist, emergency medicine physician, trainee (fellows and residents) and others. RESULTS: Of 3000 invited to participate, 1506 (1027 non-interventionists, 478 interventionists, 1 declined to specify) physicians completed the study. Interventionist respondents were more likely to proceed directly to EVT (39.5% vs. 19.5%; p < 0.0001) compared to non-interventionist respondents in patients with favorable ASPECTS (Alberta Stroke Program Early CT Score). Despite no difference in access to advanced imaging, interventionists were more likely to prefer CT/CTA alone (34.8% vs. 21.0%) and less likely to prefer CT/CTA/CTP (39.1% vs. 52.4%) for patient selection (p < 0.0001). When faced with uncertainty, non-interventionists were more likely to follow clinical guidelines (45.1% vs. 30.2%) while interventionists were more likely to follow their assessment of evidence (38.7% vs. 27.0%) (p < 0.0001). CONCLUSION: Interventionists were less likely to use advanced imaging techniques in selecting LVO patients presenting in the late window and more likely to base their decisions on their assessment of evidence rather than published guidelines. These results reflect gaps between interventionists and non-interventionists reliance on clinical guidelines, the limits of available evidence, and clinician belief in the utility of advanced imaging.

Research protocol - Assessing Post-Stroke Psychology Longitudinal Evaluation (APPLE) study: A prospective cohort study in stroke.

Background: Cognitive and mood problems have been highlighted as priorities in stroke research and guidelines recommend early screening. However, there is limited detail on the preferred approach.We aimed to (1) determine the optimal methods for evaluating psychological problems that pre-date stroke; (2) assess the test accuracy, feasibility and acceptability of brief cognitive and mood tests used at various time-points following stroke; (3) describe temporal changes in cognition and mood following stroke and explore predictors of change. Methods: We established a multi-centre, prospective, observational cohort with acute stroke as the inception point - Assessing Post-stroke Psychology Longitudinal Evaluation (APPLE). We approached patients admitted with stroke or transient ischaemic attack (TIA) from 11 different hospital sites across the United Kingdom. Baseline demographics, clinical, functional, cognitive, and mood data were collected. Consenting stroke survivors were followed up with more extensive evaluations of cognition and mood at 1, 6, 12 and 18 months. Results: Continuous recruitment was from February 2017 to February 2019. With 357 consented to full follow-up. Eighteen-month assessments were completed in September 2020 with permissions in-place for longer term in-person or electronic follow-up. A qualitative study has been completed, and a participant sample biobank and individual participant database are both available. Discussion: The APPLE study will provide guidance on optimal tool selection for cognitive and mood assessment both before and after stroke, as well as information on prognosis and natural history of neuropsychological problems in stroke. The study data, neuroimaging and tissue biobank are all available as a resource for future research.

The effects of apixaban on clot characteristics in atrial fibrillation: A novel pharmacodynamic biomarker.

Atrial fibrillation (AF) is a major risk factor for stroke. We aim to characterize AF patients and the effects of apixaban therapy in terms of clot microstructure using gel point analysis, a novel biomarker. Seventy-eight patients were included in the study, 50 Stroke with AF (AF-S), and 28 AF without stroke (AF). Pre- and post-anticoagulation samples were collected: gel point (GP) analysis was performed to obtain (i) TGP (the time taken to reach the GP or the clot formation time) and (ii) df, the fractal dimension of the clot, a quantification of clot fibrin microstructure at the GP. At baseline, the AF-S group had a df  = 1.70 (±0.05) and TGP = 306 (±73 s). The AF group had a df = 1.70 ± 0.05 and TGP = 346 ± 78 s, showing a significantly shortened TGP in the stroke group (p = .008). For both groups, apixaban significantly prolonged TGP, p = .005, but resulted in no change in df. Apixaban prolonged clotting time while having no significant impact on the blood's ability to form stable clots (no change in df ). This indicates that apixaban provides protection from the formation of thrombi by reducing clotting kinetics.

Challenges in reducing TIA clinic waiting times from 9 to 3 days in an acute Welsh hospital.

A patient impact project which successfully reduced the transient ischaemic attack (TIA) clinic waiting time from 9 to 3 days in an acute Welsh hospital, revealing the challenges faced and how alternative thinking and team work improved care given to our service users. Evaluating current situation, careful planning with multiple brainstorming meetings, 4 N chart and driver diagram with change ideas laid the foundation for this service improvement. Run charts, statistical process control and Pareto charts helped to identify the issues that are hindering the progress, which when rectified, reduced the clinic waiting times. Avoiding clinic cancellations by cross covering TIA clinics with mutual agreement among consultants and redeployment of ward staff to support clinics resulted in a positive impact to the patients. The average waiting time to see a patient in TIA clinic dropped from 9 days to just 3 days as a result of this, reflecting the hard-working and proactive nature of a team following a collaborative leadership journey. The service improvement initiative for 'avoiding clinic cancellations' was implemented in January 2017 and has reduced our waiting times by three times. Repeat analysis by six monthly Plan Do Study Act cycles revealed that this improvement is sustained.

If you build it, will they eat it? Consumer preferences for plant-based and cultured meat burgers.

In a hypothetical choice experiment consumers were given the option of purchasing burgers that were made from beef, plant-based protein, or cultured meat. Willingness to purchase plant-based and cultured meat burgers is linked to age, sex, views of other food technologies, and attitudes towards the environment and agriculture. Although consumers were told that all burgers tasted the same, there was a marked preference for beef burgers. A mixed-logit model predicts that, if prices were equal, 65% of consumers would purchase the beef burger, 21% would purchase the plant-based burger, 11% would purchase the cultured meat burger, and 4% would make no purchase. Preferences for plant-based and cultured meat burgers are found to be highly, but not perfectly, correlated.

Neptune: a bioinformatics tool for rapid discovery of genomic variation in bacterial populations.

The ready availability of vast amounts of genomic sequence data has created the need to rethink comparative genomics algorithms using 'big data' approaches. Neptune is an efficient system for rapidly locating differentially abundant genomic content in bacterial populations using an exact k-mer matching strategy, while accommodating k-mer mismatches. Neptune's loci discovery process identifies sequences that are sufficiently common to a group of target sequences and sufficiently absent from non-targets using probabilistic models. Neptune uses parallel computing to efficiently identify and extract these loci from draft genome assemblies without requiring multiple sequence alignments or other computationally expensive comparative sequence analyses. Tests on simulated and real datasets showed that Neptune rapidly identifies regions that are both sensitive and specific. We demonstrate that this system can identify trait-specific loci from different bacterial lineages. Neptune is broadly applicable for comparative bacterial analyses, yet will particularly benefit pathogenomic applications, owing to efficient and sensitive discovery of differentially abundant genomic loci. The software is available for download at: http://github.com/phac-nml/neptune.

Body mass and wages: New evidence from quantile estimation.

I estimate the effect of body mass index (BMI) on wages across the unconditional distribution of wages. I find that for whites and Hispanics the effect of BMI is generally decreasing across the wage distribution; at the .9 quantile of the wage distribution, a two standard deviation increase in BMI reduces wages by 8% for white males, 13% for white females, 9% for Hispanic males, and 16% for Hispanic females. Conversely, at the .1 quantile, a two standard deviation increase in BMI affects wages by less than 2% for all these groups. For black males, the effect of BMI is positive, and either increasing or non-linear in wages. For black females, the estimates tend to be more uniform across the wage distribution. I discuss possible explanations for these inter-quantile differences including preference discrimination, productivity differences, and statistical discrimination. The results point to a new explanation for the observed correlation between socioeconomic status and body weight: individuals with higher income earning potential have differential incentives to maintain a lower BMI.

Mannose metabolism in recombinant CHO cells and its effect on IgG glycosylation.

Understanding the causes of high-mannose (HM) glycosylation of recombinant IgG in CHO cells would facilitate the production of therapeutics. CHO cells grown with mannose as the major carbon source demonstrated a dramatic increase in total HM glycosylation in recombinant IgG, with no effect on cell growth, viability, or titer. Quantitative metabolomics and (13) C flux analysis were used to explore the mechanism for increased HM glycosylation and understand the metabolism of mannose in CHO cells. It was demonstrated that mannose was a good carbon source for CHO cell growth and IgG production, readily entering both glycolysis and the TCA Cycle. Previous mechanisms for increased HM glycosylation during antibody production have been attributed to changes in pH, osmolality, increased specific productivity, and nutrient limitation. The results from this study propose a novel mechanism where an increased carbon flux in the GDP-mannose synthetic pathway increased the intracellular concentration of mannose-containing metabolites. The abnormally high concentration of mannose and mannose-metabolites were shown to inhibit α-mannosidase activity and it was proposed that this inhibition in the ER and Golgi caused the production of IgG with increased high-mannose glycosylation. Biotechnol. Bioeng. 2016;113: 1468-1480. © 2016 Wiley Periodicals, Inc.

Real-time product attribute control to manufacture antibodies with defined N-linked glycan levels.

Pressures for cost-effective new therapies and an increased emphasis on emerging markets require technological advancements and a flexible future manufacturing network for the production of biologic medicines. The safety and efficacy of a product is crucial, and consistent product quality is an essential feature of any therapeutic manufacturing process. The active control of product quality in a typical biologic process is challenging because of measurement lags and nonlinearities present in the system. The current study uses nonlinear model predictive control to maintain a critical product quality attribute at a predetermined value during pilot scale manufacturing operations. This approach to product quality control ensures a more consistent product for patients, enables greater manufacturing efficiency, and eliminates the need for extensive process characterization by providing direct measures of critical product quality attributes for real time release of drug product.

Dysphagia, dysphonia and sore throat following cerebral infarction: an unexpected cause.

A 75-year-old woman presented with left-sided weakness. There was no speech disturbance or reported swallowing difficulties. CT of the head revealed infarction in the territory of the right middle cerebral artery. The patient was transferred to the acute stroke unit and a nasogastric tube was placed following a failed swallow screening test. The following day, on assessment, there was considerable pain on swallowing. The tone and quality of the patient's voice had deteriorated and there was significant dysphagia. Seven days later a plastic item, later identified as the patient's denture, was expectorated. Following this, the dysphagia, dysphonia and sore throat rapidly resolved. The case highlights the importance of considering foreign body in the differential, and oral cavity examination in the assessment of a patient with dysphagia and sore throat is essential.

Neurological subtle signs and cognitive development: a study in late childhood and adolescence.

INTRODUCTION AND AIM: Neurological subtle signs (NSS) are often observed during the neurological examination of children and tend to disappear with age. Their persistence into late adolescence or young adulthood has been related to psychiatric and neurocognitive disorders. To provide a better understanding of their functional basis, a longitudinal correlational study with neurocognitive measurements was performed. METHOD: We conducted multiple regression and correlation analyses of NSS with demographic and cognitive measures on a subset of 341 healthy children (56% males), taking part in a longitudinal dental study. Participants, whose ages ranged between 11-15 years, at first evaluation, undertook yearly, during 5 years, a 6-item NSS exam (producing a total score ranging between 0-18) and a comprehensive battery of neurocognitive tests. Effects of age, gender, IQ, and 7 neurocognitive factors on NSS were analyzed. RESULTS: Over the years, NSS scores correlated consistently with selective attention (Stroop test), motor speed (finger tapping), and visuomotor speed (pegboard speed). DISCUSSION: These results suggest that the disappearance of NSS in late childhood and adolescence occurs primarily in parallel with the development of motor and visuomotor functions and secondarily in relation to higher order functions such as selective attention (Stroop) and executive control (B-A Trails difference).

Identifying the CHO secretome using mucin-type O-linked glycosylation and click-chemistry.

Chinese hamster ovary cells (CHO) are the most common cell line used in the production of therapeutic proteins. Understanding the complex pattern of secreted host cell proteins (HCP) that are released by CHO cells will facilitate the development of new recombinant protein production processes. In this study, we have adapted the N-azido-galactosamine (GalNAz) metabolic labeling method to enable the mass spectrometry identification and quantification of secreted proteins in cell culture media. CHO DG44 and CHO-S cells were cultured in media containing GalNAz, which was metabolically incorporated into mucin-type O-linked glycans of secreted proteins. These proteins were effectively enriched using click-chemistry from the cell culture media, allowing for the analysis of secreted proteins across multiple days of cell growth. When compared to the standard method for secretome analysis, the GalNAz method not only increased the total number of proteins identified but dramatically improved the quality of data by decreasing the number of background proteins (cytosolic or nuclear) to essentially zero.

A filtered database search algorithm for endogenous serum protein carbonyl modifications in a mouse model of inflammation.

During inflammation, the resulting oxidative stress can damage surrounding host tissue, forming protein-carbonyls. The SJL mouse is an experimental animal model used to assess in vivo toxicological responses to reactive oxygen and nitrogen species from inflammation. The goals of this study were to identify the major serum proteins modified with a carbonyl functionality and to identify the types of carbonyl adducts. To select for carbonyl-modified proteins, serum proteins were reacted with an aldehyde reactive probe that biotinylated the carbonyl modification. Modified proteins were enriched by avidin affinity and identified by two-dimensional liquid chromatography tandem MS. To identify the carbonyl modification, tryptic peptides from serum proteins were subjected to avidin affinity and the enriched modified peptides were analyzed by liquid chromatography tandem MS. It was noted that the aldehyde reactive probe tag created tag-specific fragment ions and neutral losses, and these extra features in the mass spectra inhibited identification of the modified peptides by database searching. To enhance the identification of carbonyl-modified peptides, a program was written that used the tag-specific fragment ions as a fingerprint (in silico filter program) and filtered the mass spectrometry data to highlight only modified peptides. A de novo-like database search algorithm was written (biotin peptide identification program) to identify the carbonyl-modified peptides. Although written specifically for our experiments, this software can be adapted to other modification and enrichment systems. Using these routines, a number of lipid peroxidation-derived protein carbonyls and direct side-chain oxidation proteins carbonyls were identified in SJL mouse serum.

Proteins modified by the lipid peroxidation aldehyde 9,12-dioxo-10(E)-dodecenoic acid in MCF7 breast cancer cells.

The hydroperoxide of linoleic acid (13-HPODE) degrades to 9,12-dioxo-10(E)-dodecenoic acid (DODE), which readily modifies proteins. This study identified the major proteins in MCF7 cells modified by DODE. To reduce false positives, three methods were used to identify DODE-modified proteins. First, cells were treated with a synthetically biotinylated 13-HPODE (13-HPODE-biotin). Modified proteins were enriched by neutravidin affinity and identified by two-dimensional liquid chromatography--tandem mass spectrometry (2D LC-MS/MS). Second, cells were treated with native 13-HPODE. Protein carbonyls were biotinylated with an aldehyde reactive probe, and modified proteins were enriched by neutravidin affinity and identified by 2D LC-MS/MS. Third, using a newly developed DODE antibody, DODE-modified proteins were located by 2D sodium dodecyl sulfate--polyacrylamide gel electrophoresis and Western blot and identified by in-gel digestion and LC-MS/MS. Analysis of the proteins characterized by all three methods revealed a significant overlap and identified 32 primary proteins modified by DODE in MCF7 cells. These results demonstrated the feasibility for the cellular formation of DODE protein-carbonyl adducts that may be future indicators of oxidative stress.

Factors affecting the retrieval of famous names.

Tests of famous faces are used to study language and memory. Yet, the effect of stimulus properties on performance has not been fully investigated. To identify factors influencing proper name retrieval and to probe stimulus-specific parameters within proper name lexicon, we analysed the results obtained by 300 healthy participants on a test of famous faces that includes 74 personalities. A factor analysis yielded five main factors that were characterized by language (national or foreign names), epoch of peak popularity (current, recent or past) and occupation (politicians, entertainment and sports) of the personalities. Multiple regression analysis showed that participants' education, age and gender accounted for 10-32% of the variance in factor scores. These results indicate that there are variables of the stimulus and participants' that must be taken into account in proper name testing and in designing tests aimed to differentiate age-associated difficulties from cognitive decline.