A Comparison of Two Methods for MRI Classification of At-Risk Tissue and Core Infarction

Objective: To compare how at-risk tissue and core infarction were defined in two major trials that tested the use of MRI in selecting acute stroke patients for endovascular recanalization therapy.Methods: MRIs from 12 patients evaluated for possible endovascular therapy were processed using the methods published from two major trials, MR RESCUE and DEFUSE 2. Specifically, volumes of at-risk tissue and core infarction were generated from each patient’s MRI. MRIs were then classified as to whether or not they met criteria for salvageable tissue: penumbral pattern for MR RESCUE and/or target profile for DEFUSE 2) as defined by each trial.Results: Volumes of at-risk tissue by the two definitions were correlated (p=0.017) while the volumes of core infarct were not (p=0.059). The volume of at-risk tissue was consistently larger when defined by the penumbral pattern than the target profile while the volume of core infarct was consistently larger when defined by the target profile than the penumbral pattern. When these volumes were used to classify the MRI scans, nine out of 12 patients (75%) were classified as having a penumbral pattern, while only 4 out of 12 patients (33%) were classified as having a target profile. Of the 9 patients classified as penumbral pattern, 5 (55%) were classified differently by the target profile.Interpretation: Our analysis found that the MR RESCUE trial defined salvageable tissue in a way which made it more likely for patients be labeled as favorable for treatment. For the cohort of patients examined in this study, had they been enrolled in both trials, most of the patients identified as having salvageable tissue by the MR RESCUE trial would not have been considered to have salvageable tissue in the DEFUSE 2 trial. Caution should be taken in concluding that MRI selection for endovascular therapy is not effective as imaging selection criteria were substantially different between trials

Beyond Paradigms in Cultural Astronomy. Proceedings of the 27th SEAC conference held together with the EAA

Proceedings of the 27th SEAC conference held together with the EAA.-- Editors: A. César González-García, Roslyn M. Frank, Lionel D. Sims, Michael A. Rappenglück, Georg Zotti, Juan A. Belmonte, Ivan Šprajc.Cultural Astronomy is the endeavour to understand the role of the sky in past and present societies, and how these societies incorporated the sky into their culture. This broad ranging discipline is closely related to archaeology when investigating material remains of the past. Cultural Astronomy also explores the role of the heavens from the perspectives of the anthropological sciences. In recent decades the discipline has been concerned with methodological and theoretical issues. This volume offers chapters based on presentations at the 27th SEAC meeting held in Bern (2019). These chapters provide a vivid image of front-line research in diverse areas, from Roman light and shadow effects to highlight power, to Maya city organization, Etruscan temple orientation or the ontology of the sky.Peer reviewe

High Levels of Diversity Uncovered in a Widespread Nominal Taxon: Continental Phylogeography of the Neotropical Tree Frog

Species distributed across vast continental areas and across major biomes provide unique model systems for studies of biotic diversification, yet also constitute daunting financial, logistic and political challenges for data collection across such regions. The tree frog Dendropsophus minutus (Anura: Hylidae) is a nominal species, continentally distributed in South America, that may represent a complex of multiple species, each with a more limited distribution. To understand the spatial pattern of molecular diversity throughout the range of this species complex, we obtained DNA sequence data from two mitochondrial genes, cytochrome oxidase I (COI) and the 16S rhibosomal gene (16S) for 407 samples of D. minutus and closely related species distributed across eleven countries, effectively comprising the entire range of the group. We performed phylogenetic and spatially explicit phylogeographic analyses to assess the genetic structure of lineages and infer ancestral areas. We found 43 statistically supported, deep mitochondrial lineages, several of which may represent currently unrecognized distinct species. One major clade, containing 25 divergent lineages, includes samples from the type locality of D. minutus. We defined that clade as the D. minutus complex. The remaining lineages together with the D. minutus complex constitute the D. minutus species group. Historical analyses support an Amazonian origin for the D. minutus species group with a subsequent dispersal to eastern Brazil where the D. minutus complex originated. According to our dataset, a total of eight mtDNA lineages have ranges >100,000 km2. One of them occupies an area of almost one million km2 encompassing multiple biomes. Our results, at a spatial scale and resolution unprecedented for a Neotropical vertebrate, confirm that widespread amphibian species occur in lowland South America, yet at the same time a large proportion of cryptic diversity still remains to be discovered

Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.Peer reviewe

A critical review and development of a conceptual model of exclusion from social relations for older people

Social exclusion is complex and dynamic, and it leads to the non-realization of social, economic, political or cultural rights or participation within a society. This critical review takes stock of the literature on exclusion of social relations. Social relations are defined as comprising social resources, social connections and social networks. An evidence review group undertook a critical review which integrates, interprets and synthesizes information across studies to develop a conceptual model of exclusion from social relations. The resulting model is a subjective interpretation of the literature and is intended to be the starting point for further evaluations. The conceptual model identifies individual risks for exclusion from social relations (personal attributes, biological and neurological risk, retirement, socio-economic status, exclusion from material resources and migration). It incorporates the evaluation of social relations, and the influence of psychosocial resources and socioemotional processes, sociocultural, social-structural, environmental and policy contextual influences on exclusion from social relations. It includes distal outcomes of exclusion from social relations, that is, individual well-being, health and functioning, social opportunities and social cohesion. The dynamic relationships between elements of the model are also reported. We conclude that the model provides a subjective interpretation of the data and an excellent starting point for further phases of conceptual development and systematic evaluation(s). Future research needs to consider the use of sophisticated analytical tools and an interdisciplinary approach in order to understand the underlying biological and ecopsychosocial associations that contribute to individual and dynamic differences in the experience of exclusion from social relation

Critical Care Needs in Patients with Diffusion-Weighted Imaging Negative MRI after tPA--Does One Size Fit All?

Patients who receive intravenous (IV) tissue plasminogen activator (tPA) for ischemic stroke are currently monitored in an intensive care unit (ICU) or a comparable stroke unit for at least 24 hours due to the high frequency of neurological exams and vital sign checks. The present study evaluates ICU needs in patients with diffusion-weighted imaging (DWI) negative MRI after IV tPA.A retrospective chart review was performed for 209 patients who received IV tPA for acute stroke. Data on stroke risk factors, physiologic parameters, stroke severity, MRI characteristics, and final diagnosis were collected. The timing and nature of ICU interventions, if needed, was recorded. Multivariable logistic regression was used to determine factors associated with subsequent ICU needs.Patients with cerebral infarct on MRI after tPA had over 9 times higher odds of requiring ICU care compared to patients with DWI negative MRI (OR 9.2, 95% CI 2.49-34.15). All DWI negative patients requiring ICU care did so by the end of tPA infusion (p = 0.006). Among patients with DWI negative MRI, need for ICU interventions was associated with higher NIH Stroke Scale (NIHSS) scores (p<0.001), uncontrolled hypertension (p<0.001), seizure at onset (p = 0.002), and reduced estimated glomerular filtration rate (eGFR) (p = 0.010).Only a small number of DWI negative patients required ICU care. In patients without critical care needs by the end of thrombolysis, post-tPA MRI may be considered for triaging DWI negative patients to a less resource intense monitoring environment

Predictors of critical care needs after IV thrombolysis for acute ischemic stroke.

BACKGROUND AND PURPOSE: Intravenous (IV) tissue plasminogen activator (tPA) is the only Food and Drug Administration (FDA)-approved treatment for acute ischemic stroke. Post tPA patients are typically monitored in an intensive care unit (ICU) for at least 24 hours. However, rigorous evidence to support this practice is lacking. This study evaluates factors that predict ICU needs after IV thrombolysis. METHODS: A retrospective chart review was performed for 153 patients who received intravenous tPA for acute ischemic stroke. Data on stroke risk factors, physiologic parameters on presentation, and stroke severity were collected. The timing and nature of an intensive care intervention, if needed, was recorded. Using multivariable logistic regression, we determined factors associated with requiring ICU care. RESULTS: African American race (Odds Ratio [OR] 8.05, 95% Confidence Interval [CI] 2.65-24.48), systolic blood pressure, and National Institutes of Health Stroke Scale (NIHSS) (OR 1.20 per point increase, 95% CI 1.09-1.31) were predictors of utilization of ICU resources. Patients with an NIHSS≥10 had a 7.7 times higher risk of requiring ICU resources compared to patients who presented with an NIHSS<10 (p<0.001). Most patients with ICU needs developed them prior to the end of tPA infusion (81.0%, 95% CI 68.8-93.1). Only 7% of patients without ICU needs by the end of the tPA infusion went on to require ICU care later on. These patients were more likely to have diabetes mellitus and had significantly higher NIHSS compared to patients without further ICU needs (mean NIHSS 17.3, 95% CI 11.5-22.9 vs. 9.2, 95% CI 7.7-9.6). CONCLUSION: Race, NIHSS, and systolic blood pressure predict ICU needs following tPA for acute ischemic stroke. We propose that patients without ICU needs by the end of the tPA infusion might be safely monitored in a non-ICU setting if NIHSS at presentation is low

Minority race and male sex as risk factors for non-beneficial gastrostomy tube placements after stroke.

Percutaneous endoscopic gastrostomy (PEG) tubes are widely used for enteral feeding after stroke; however, PEG tubes placed in patients in whom death is imminent are considered non-beneficial.We sought to determine whether placement of non-beneficial PEG tubes differs by race and sex.In this retrospective cohort study, inpatient admissions for stroke patients who underwent palliative/withdrawal of care, were discharged to hospice, or died during the hospitalization, were identified from the Nationwide Inpatient Sample between 2007 and 2011. Logistic regression was used to evaluate the association between race and sex with PEG placement.Of 36,109 stroke admissions who underwent palliative/withdrawal of care, were discharge to hospice, or experienced in-hospital death, a PEG was placed in 2,258 (6.3%). Among PEG recipients 41.1% were of a race other than white, while only 22.0% of patients without PEG were of a minority race (p<0.001). The proportion of men was higher among those with compared to without a PEG tube (50.0% vs. 39.2%, p<0.001). Minority race was associated with PEG placement compared to whites (OR 1.75, 95% CI 1.57-1.96), and men had 1.27 times higher odds of PEG compared to women (95% CI 1.16-1.40). Racial differences were most pronounced among women: ethnic/racial minority women had over 2-fold higher odds of a PEG compared to their white counterparts (OR 2.09, 95% CI 1.81-2.41), while male ethnic/racial minority patients had 1.44 increased odds of a PEG when compared to white men (95% CI 1.24-1.67, p-value for interaction <0.001).Minority race and male sex are risk factors for non-beneficial PEG tube placements after stroke