Diffusion tensor imaging analysis along the perivascular space in the UK biobank.

BACKGROUND: The recently discovered glymphatic system may support the removal of neurotoxic proteins, mainly during sleep, that are associated with neurodegenerative diseases such as Alzheimer's and Parkinson's Disease. Diffusion tensor image analysis along the perivascular space (DTI-ALPS) has been suggested as a method to index the health of glymphatic system (with higher values indicating a more intact glymphatic system). Indeed, in small-scale studies the DTI-ALPS index has been shown to correlate with age, cognitive health, and sleep, and is higher in females than males. OBJECTIVE: To determine whether these relationships are stable we replicated previous findings associating the DTI-ALPS index with demographic, sleep-related, and cognitive markers in a large sample of participants from the UK Biobank. METHODS: We calculated the DTI-ALPS index in UK Biobank participants (n = 17723). Using Bayesian and Frequentist analysis approaches, we replicate previously reported relationships between the DTI-ALPS index. RESULTS: We found the predicted associations between the DTI-ALPS index and age, longest uninterrupted sleep window (LUSWT) on a typical night, cognitive performance, and sex. However, these effects were substantially smaller than those found in previous studies. Parameter estimates from this study may be used as priors in subsequent studies using a Bayesian approach. These results suggest that the DTI-ALPS index is consistently, and therefore predictably, associated with demographics, LUWST, and cognition. CONCLUSION: We propose that the metric, calculated for the first time in a large-scale, population-based cohort, is a stable measure, but one for which stronger links to glymphatic system function are needed before it can be used to understand the relationships between glymphatic system function and health outcomes reported in the UK Biobank.

Sex and gender differences in acute stroke care: metrics, access to treatment and outcome. A territorial analysis of the Stroke Code System of Catalonia.

INTRODUCTION: Previous studies have reported differences in the management and outcome of women stroke patients in comparison with men. We aim to analyze sex and gender differences in the medical assistance, access to treatment and outcome of acute stroke patients in Catalonia. PATIENTS AND METHODS: Data were obtained from a prospective population-based registry of stroke code activations in Catalonia (CICAT) from January/2016 to December/2019. The registry includes demographic data, stroke severity, stroke subtype, reperfusion therapy, and time workflow. Centralized clinical outcome at 90 days was assessed in patients receiving reperfusion therapy. RESULTS: A total of 23,371 stroke code activations were registered (54% men, 46% women). No differences in prehospital time metrics were observed. Women more frequently had a final diagnosis of stroke mimic, were older and had a previous worse functional situation. Among ischemic stroke patients, women had higher stroke severity and more frequently presented proximal large vessel occlusion. Women received more frequently reperfusion therapy (48.2% vs 43.1%, p < 0.001). Women tended to present a worse outcome at 90 days, especially for the group receiving only IVT (good outcome 56.7% vs 63.8%; p < 0.001), but not for the group of patients treated with IVT + MT or MT alone, although sex was not independently associated with clinical outcome in logistic regression analysis (OR 1.07; 95% CI, 0.94-1.23; p = 0.27) nor in the analysis after matching using the propensity score (OR 1.09; 95% CI, 0.97-1.22). DISCUSSION AND CONCLUSION: We found some differences by sex in that acute stroke was more frequent in older women and the stroke severity was higher. We found no differences in medical assistance times, access to reperfusion treatment and early complications. Worse clinical outcome at 90 days in women was conditioned by stroke severity and older age, but not by sex itself.

Bottlenecks in the Acute Stroke Care System during the COVID-19 Pandemic in Catalonia.

INTRODUCTION: The COVID-19 pandemic resulted in significant healthcare reorganizations, potentially striking standard medical care. We investigated the impact of the COVID-19 pandemic on acute stroke care quality and clinical outcomes to detect healthcare system's bottlenecks from a territorial point of view. METHODS: Crossed-data analysis between a prospective nation-based mandatory registry of acute stroke, Emergency Medical System (EMS) records, and daily incidence of COVID-19 in Catalonia (Spain). We included all stroke code activations during the pandemic (March 15-May 2, 2020) and an immediate prepandemic period (January 26-March 14, 2020). Primary outcomes were stroke code activations and reperfusion therapies in both periods. Secondary outcomes included clinical characteristics, workflow metrics, differences across types of stroke centers, correlation analysis between weekly EMS alerts, COVID-19 cases, and workflow metrics, and impact on mortality and clinical outcome at 90 days. RESULTS: Stroke code activations decreased by 22% and reperfusion therapies dropped by 29% during the pandemic period, with no differences in age, stroke severity, or large vessel occlusion. Calls to EMS were handled 42 min later, and time from onset to hospital arrival increased by 53 min, with significant correlations between weekly COVID-19 cases and more EMS calls (rho = 0.81), less stroke code activations (rho = -0.37), and longer prehospital delays (rho = 0.25). Telestroke centers were afflicted with higher reductions in stroke code activations, reperfusion treatments, referrals to endovascular centers, and increased delays to thrombolytics. The independent odds of death increased (OR 1.6 [1.05-2.4], p 0.03) and good functional outcome decreased (mRS ≤2 at 90 days: OR 0.6 [0.4-0.9], p 0.015) during the pandemic period. CONCLUSION: During the COVID-19 pandemic, Catalonia's stroke system's weakest points were the delay to EMS alert and a decline of stroke code activations, reperfusion treatments, and interhospital transfers, mostly at local centers. Patients suffering an acute stroke during the pandemic period had higher odds of poor functional outcome and death. The complete stroke care system's analysis is crucial to allocate resources appropriately.

Genome-wide transcriptome study in skin biopsies reveals an association of E2F4 with cadasil and cognitive impairment.

CADASIL is a small vessel disease caused by mutations in NOTCH3 that lead to an odd number of cysteines in the EGF-like repeat domain, causing protein misfolding and aggregation. The main symptoms are migraine, psychiatric disturbances, recurrent strokes and dementia, being executive function characteristically impaired. The molecular pathways altered by this receptor aggregation need to be studied further. A genome-wide transcriptome study (four cases paired with three healthy siblings) was carried out, in addition to a qRT-PCR for validation purposes (ten new cases and eight new controls). To study the expression profile by cell type of the significant mRNAs found, we performed an in situ hybridization (ISH) (nine cases and eight controls) and a research in the Single-nuclei Brain RNA-seq expression browser (SNBREB). Pathway analysis enrichment was carried out with Gene Ontology and Reactome. Neuropsychological tests were performed in five of the qRT-PCR cases. The two most significant differentially expressed mRNAs (BANP, p-value = 7.23 × 10-4 and PDCD6IP, p-value = 8.36 × 10-4) were selected for the validation study by qRT-PCR. Additionally, we selected two more mRNAs (CAMK2G, p-value = 4.52 × 10-3 and E2F4, p-value = 4.77 × 10-3) due to their association with ischemic neuronal death. E2F4 showed differential expression in the genome-wide transcriptome study and in the qRT-PCR (p = 1.23 × 10-3), and it was upregulated in CADASIL cases. Furthermore, higher E2F4 expression was associated with worse executive function (p = 2.04 × 10-2) and attention and information processing speed (IPS) (p = 8.73 × 10-2). In situ hibridization showed E2F4 expression in endothelial and vascular smooth vessel cells. In silico studies indicated that E2F4 is also expressed in brain endothelial cells. Among the most significant pathways analyzed, there was an enrichment of vascular development, cell adhesion and vesicular machinery terms and autophagy process. E2F4 is more highly expressed in the skin biopsy of CADASIL patients compared to controls, and its expression is present in endothelial cells and VSMCs. Further studies are needed to understand whether E2F4 could be useful as a biomarker, to monitor the disease or be used as a therapeutic target.

Vascular Occlusion Evolution in Endovascular Reperfusion Candidates Transferred from Primary to Comprehensive Stroke Centers.

BACKGROUND: The evolution of the symptomatic intracranial occlusion during transfers from primary stroke centers (PSCs) to comprehensive stroke centers (CSCs) for endovascular treatment (EVT) is not widely known. Our aim was to identify factors related to partial or complete recanalization (REC) at CSC arrival in patients with a documented large vessel occlusion (LVO) in PSC transferred for EVT evaluation to better define the workflow at CSC of this group of patients. METHODS: We conducted an observational, multicenter study from a prospective, government-mandated, population-based registry of stroke patients with documented LVO at PSC transferred to CSC for EVT from January 2017 to June 2019. The primary end point was defined as partial or complete REC that precluded EVT at CSC arrival (REC). We evaluated the association between baseline, treatment variables and time intervals with the presence of REC. RESULTS: From 589 patients, the rate of REC at CSC was 10.5% in all LVO patients transferred from PSC to CSC for EVT evaluation. On univariate analysis, lower PSC-NIHSS (median 12vs.16, p = 0.001), tPA treatment at PSC (13.7 vs. 5.0%; p = 0.001), presence of M2 occlusion on PSC (16.8 vs. 9%; p = 0.023), and clinical improvement at CSC arrival (21.7 vs. 9.6% p = 0.001) were associated with REC at CSC. On multivariate analysis, clinical improvement at CSC arrival (p < 0.001, OR: 5.96 95% CI: 2.5-13.9) and PSC tPA treatment predicted REC (p = 0.003, OR: 4.65, 95% CI: 1.73-12.4). CONCLUSION: REC at CSC arrival occurs exceptionally in patients with a documented LVO on PSC. Repeating a second vascular study before EVT would not be necessary in most patients. Despite its modest effect, tPA treatment at PSC was an independent predictor of REC.

Systematic Review of Cysteine-Sparing NOTCH3 Missense Mutations in Patients with Clinical Suspicion of CADASIL.

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is caused by mutations in the NOTCH3 gene, affecting the number of cysteines in the extracellular domain of the receptor, causing protein misfolding and receptor aggregation. The pathogenic role of cysteine-sparing NOTCH3 missense mutations in patients with typical clinical CADASIL syndrome is unknown. The aim of this article is to describe these mutations to clarify if any could be potentially pathogenic. Articles on cysteine-sparing NOTCH3 missense mutations in patients with clinical suspicion of CADASIL were reviewed. Mutations were considered potentially pathogenic if patients had: (a) typical clinical CADASIL syndrome; (b) diffuse white matter hyperintensities; (c) the 33 NOTCH3 exons analyzed; (d) mutations that were not polymorphisms; and (e) Granular osmiophilic material (GOM) deposits in the skin biopsy. Twenty-five different mutations were listed. Four fulfill the above criteria: p.R61W; p.R75P; p.D80G; and p.R213K. Patients carrying these mutations had typical clinical CADASIL syndrome and diffuse white matter hyperintensities, mostly without anterior temporal pole involvement. Cysteine-sparing NOTCH3 missense mutations are associated with typical clinical CADASIL syndrome and typical magnetic resonance imaging (MRI) findings, although with less involvement of the anterior temporal lobe. Hence, these mutations should be further studied to confirm their pathological role in CADASIL.

Mesenchymal Stem Cells Loaded with p5, Derived from CDK5 Activator p35, Inhibit Calcium-Induced CDK5 Activation in Endothelial Cells.

The potential use of stem cells as therapeutics in disease has gained momentum over the last few years and recently phase-I clinical trials have shown favourable results in treatment of a small cohort of acute stroke patients. Similarly, they have been used in preclinical models drug-loaded for the effective treatment of solid tumours. Here we have characterized uptake and release of a novel p5-cyclin-dependent kinase 5 (CDK5) inhibitory peptide by mesenchymal stem cells and showed release levels capable of blocking aberrant cyclin-dependent kinase 5 (CDK5) signaling pathways, through phosphorylation of cyclin-dependent kinase 5 (CDK5) and p53. These pathways represent the major acute mechanism stimulating apoptosis after stroke and hence its modulation could benefit patient recovery. This work indicates a potential use for drug-loaded stem cells as delivery vehicles for stroke therapeutics and in addition as anticancer receptacles particularly, if a targeting and/or holding mechanism can be defined.

Whole exome sequencing analysis reveals TRPV3 as a risk factor for cardioembolic stroke.

Genetic studies suggest that hundreds of genes associated with stroke remain unidentified. Exome sequencing proves useful for finding new genes associated with stroke. We aimed to find new genetic risk factors for cardioembolic stroke by analysing exome sequence data using new strategies. For discovery, we analysed 42 cardioembolic stroke cases and controls with extreme phenotypes (cohort 1), and for replication, 32 cardioembolic stroke cases and controls (cohort 2) using the SeqCapExome capture kit. We then analysed the replicated genes in two new cohorts that comprised 834 cardioembolic strokes and controls (cohort 3) and 64,373 cardioembolic strokes and controls (cohort 4). Transcriptomic in-silico functional analyses were also performed. We found 26 coding regions with a higher frequency of mutations in cardioembolic strokes after correcting for the number of mutations found in the whole exome of every patient. The TRPV3 gene was associated with cardioembolic stroke after replication of exome sequencing analysis (p-value-discovery: 0.018, p-value-replication: 0.014). The analysis of the TRPV3 gene using polymorphisms in cohort 3 and 4 revealed two polymorphisms associated with cardioembolic stroke in both cohorts, the most significant polymorphism being rs151091899 (p-value: 3.1 × 10-05; odds ratio: 5.4) in cohort 3. The genotype of one polymorphism of TRPV3 was associated with a differential expression of genes linked to cardiac malformations. In conclusion, new strategies using exome sequence data have revealed TRPV3 as a new gene associated with cardioembolic stroke. This strategy among others might be useful in finding new genes associated with complex genetic diseases.

Access to Endovascular Treatment in Remote Areas: Analysis of the Reperfusion Treatment Registry of Catalonia.

BACKGROUND AND PURPOSE: Since demonstration of the benefit of endovascular treatment (EVT) in acute ischemic stroke patients with proximal arterial occlusion, stroke care systems need to be reorganized to deliver EVT in a timely and equitable way. We analyzed differences in the access to EVT by geographical areas in Catalonia, a territory with a highly decentralized stroke model. METHODS: We studied 965 patients treated with EVT from a prospective multicenter population-based registry of stroke patients treated with reperfusion therapies in Catalonia, Spain (SONIIA). Three different areas were defined: (A) health areas primarily covered by Comprehensive Stroke Centers, (B) areas primarily covered by local stroke centers located less than hour away from a Comprehensive Stroke Center, and (C) areas primarily covered by local stroke centers located more than hour away from a Comprehensive Stroke Center. We compared the number of EVT×100 000 inhabitants/year and time from stroke onset to groin puncture between groups. RESULTS: Baseline characteristics were similar between groups. Throughout the study period, there were significant differences in the population rates of EVT across geographical areas. EVT rates by 100 000 in 2015 were 10.5 in A area, 3.7 in B, and 2.7 in C. Time from symptom onset to groin puncture was 82 minutes longer in group B (312 minutes [245-435]) and 120 minutes longer in group C (350 minutes [284-408]) compared with group A (230 minutes [160-407]; P<0.001). CONCLUSIONS: Accessibility to EVT from remote areas is hampered by lower rate and longer time to treatment compared with areas covered directly by Comprehensive Stroke Centers.

An Inflammatory Polymorphisms Risk Scoring System for the Differentiation of Ischemic Stroke Subtypes.

UNLABELLED: Inflammation has been associated with atherothrombotic stroke and recently with cardioembolic stroke. Different genetic risk factors have been specifically associated with the subtypes of ischemic stroke (cardioembolic, atherothrombotic, and lacunar). However, there are no studies that have generated genetic risk scores for the different subtypes of ischemic stroke using polymorphisms associated with inflammation. METHODS: We have analyzed 68 polymorphisms of 30 inflammatory mediator genes in 2,685 subjects: 1,987 stroke cases and 698 controls. We generated a genetic scoring system with the most significant polymorphisms weighted by the odds ratio of every polymorphism and taken into consideration the stroke subtype. RESULTS: Three polymorphisms, rs1205 (CRP gene), rs1800779, and rs2257073 (NOS3 gene), were associated with cardioembolic stroke (p value <0.05). The score generated was only associated with the cardioembolic stroke subtype (p value: 0.001) and was replicated in an independent cohort (p value: 0.017). The subjects with the highest score presented a cardioembolic stroke in 92.2% of the cases (p value: 0.002). CONCLUSION: The genetics of inflammatory markers is more closely associated with cardioembolic strokes than with atherothrombotic or lacunar strokes. The genetic risk scoring system could be useful in the prediction and differentiation of ischemic stroke; however, it might be specific to particular ischemic stroke subtypes.

DNA methylation levels are highly correlated between pooled samples and averaged values when analysed using the Infinium HumanMethylation450 BeadChip array.

BACKGROUND: DNA methylation is a heritable and stable epigenetic mark implicated in complex human traits. Epigenome-wide association studies (EWAS) using array-based technology are becoming widely used to identify differentially methylated sites associated with complex diseases. EWAS studies require large sample sizes to detect small effects, which increases project costs. In the present study we propose to pool DNA samples in methylation array studies as an affordable and accurate alternative to individual samples studies, in order to reduce economic costs or when low amounts of DNA are available. For this study, 20 individual DNA samples and 4 pooled DNA samples were analysed using the Illumina Infinium HumanMethylation450 BeadChip array to evaluate the efficiency of the pooling approach in EWAS studies. Statistical power calculations were also performed to discover the minimum sample size needed for the pooling strategy in EWAS. RESULTS: A total of 485,577 CpG sites across the whole genome were assessed. Comparison of methylation levels of all CpG sites between individual samples and their related pooled samples revealed highly significant correlations (rho > 0.99, p-val < 10(-16)). These results remained similar when assessing the 101 most differentially methylated CpG sites (rho > 0.98, p-val < 10(-16)). Also, it was calculated that n = 43 is the minimum sample size required to achieve a 95 % statistical power and a 10(-06) significance level in EWAS, when using a DNA pool strategy. CONCLUSIONS: DNA pooling strategies seems to accurately provide estimations of averaged DNA methylation state using array based EWAS studies. This type of approach can be applied to the assessment of disease phenotypes, reducing the amount of DNA required and the cost of large-scale epigenetic analyses.

Safety and efficacy of uric acid in patients with acute stroke (URICO-ICTUS): a randomised, double-blind phase 2b/3 trial.

INTRODUCTION: Uric acid is an antioxidant with neuroprotective effects in experimental models of stroke. We assessed whether uric acid therapy would improve functional outcomes at 90 days in patients with acute ischaemic stroke. METHODS: URICO-ICTUS was a randomised, double-blind, placebo-controlled, phase 2b/3 trial that recruited patients with acute ischaemic stroke admitted to ten Spanish stroke centres. Patients were included if they were aged 18 years or older, had received alteplase within 4·5 h of symptom onset, and had an eligible National Institutes of Health Stroke Scale (NIHSS) score (>6 and ≤25) and premorbid (assessed by anamnesis) modified Rankin Scale (mRS) score (≤2). Patients were randomly allocated (1:1) to receive uric acid 1000 mg or placebo (both infused intravenously in 90 min during the infusion of alteplase), stratified by centre and baseline stroke severity. The primary outcome was the proportion of patients with excellent outcome (ie, an mRS score of 0-1, or 2 if premorbid score was 2) at 90 days, analysed in the target population (all randomly assigned patients who had been correctly diagnosed with ischaemic stroke and had begun study medication). The study is registered with ClinicalTrials.gov, number NCT00860366. FINDINGS: Between July 1, 2011, and April 30, 2013, we randomly assigned 421 patients, of whom 411 (98%) were included in the target population (211 received uric acid and 200 received placebo). 83 (39%) patients who received uric acid and 66 (33%) patients who received placebo had an excellent outcome (adjusted risk ratio 1·23 [95% CI 0·96-1·56]; p=0·099). No clinically relevant or statistically significant differences were reported between groups with respect to death (28 [13%] patients who received uric acid vs 31 [16%] who received placebo), symptomatic intracerebral haemorrhage (nine [4%] vs six [3%]), and gouty arthritis (one [<1%] vs four [2%]). 516 adverse events occurred in the uric acid group and 532 in the placebo group, of which 61 (12%) and 67 (13%), respectively, were serious adverse events (p=0·703). INTERPRETATION: The addition of uric acid to thrombolytic therapy did not increase the proportion of patients who achieved excellent outcome after stroke compared with placebo, but it did not lead to any safety concerns. FUNDING: Institute of Health Carlos III of the Spanish Ministry of Health and Fundación Doctor Melchor Colet.

Hyaluronan-mediated angiogenesis in vascular disease: uncovering RHAMM and CD44 receptor signaling pathways.

The correct formation of new blood vessels from existing vasculature (angiogenesis) is essential for embryogenesis and the effective repair of damaged or wounded tissues. However, excessive and detrimental vascularization also occurs in neoplasia, promoting tumour growth and metastasis, as well as in proliferative diabetic retinopathy and atherosclerosis. Greater understanding of the mechanisms controlling the angiogenic process will allow optimization of wound healing, and provide mechanisms to inhibit vascularization in tumours and other diseases. Evidence supports a cascade of events in which the perturbation of one of the steps is sufficient to significantly inhibit neovascularization. The extracellular macromolecules, notably glycosaminoglycans (GAGs), are important mediators of angiogenesis. Hyaluronan (HA), a large, non-sulphated GAG, was first discovered in the vitreous of the eye [.], and is ubiquitously expressed in the extracellular matrix (ECM) of tissues. Native high molecular weight HA (n-HA) is anti-angiogenic, whereas HA degradation products (o-HA; 3-10 disaccharides) stimulate endothelial cell (EC) proliferation, migration and tube formation following activation of specific HA receptors in particular, CD44 and Receptor for HA-Mediated Motility (RHAMM, CD168). The involvement of HA in the regulation of angiogenesis makes it an attractive therapeutic target. We review the role of o-HA in modulation of angiogenesis during tissue injury, and vascular disease, focusing on receptor-mediated signal transduction pathways that have been evaluated.

Meningeal carcinomatosis as the first manifestation of a transitional cell carcinoma of the bladder.

Meningeal carcinomatosis (MC) as first manifestation of a transitional cell carcinoma (TCC) of the bladder is rare. We report a 66-year-old man, smoker, who presented with two episodes of secondarily generalized partial motor seizures. The routine blood test, brain computed tomography (CT) scan, brain magnetic resonance imaging and electroencephalogram were normal. Cerebral spinal fluid (CSF) revealed a significant pleocytosis and a morphology compatible with non-differentiated non-small cell carcinoma. Broncofiberscopy, gastrofiberscopy, thoracicoabdominopelvic CT-scan and bone scintigraphy were normal but the urine cytology revealed malignant cells similar to those found in the CSF. TCC was diagnosed by cystoscopy and later necropsy confirmed the MC of this tumor. In this report we review the literature and analyze patient survival.