Vergleichende experimentell-neuropsychologische Untersuchung spezifischer Arbeitsgedächtnisdefizite bei bipolaren affektiven Störungen und Schizophrenie

Kognitive Defizite werden häufig zum Symptomenkomplex psychotischer Störungen gezählt. Störungen des Arbeitsgedächtnisses wurden in Vorstudien mit gleichem Studiendesign sowohl bei Schizophrenen (Zilles et al., 2006) als auch bipolar affektiv Erkrankten (Gruber et al., 2005) festgestellt. Bisher gab es keinen direkten Vergleich der Defizitmuster beider Krankheitsbilder. Die vorliegende Arbeit hatte zum Ziel, die diagnostische Spezifität der beobachteten Defizitmuster in den Teilbereichen des Arbeitsgedächtnisses zu untersuchen. Zusätzlich sollten Korrelationen der Arbeitsgedächtnisleistung mit der Psychopathologie dargestellt werden. Je 21 Patienten mit der Diagnose Schizophrenie und der Diagnose bipolar affektive Störung sowie 21 Kontrollprobanden wurden hinsichtlich des verbalen und visuell-räumlichen Arbeitsgedächtnisses untersucht. Die Gruppen waren nach Alter, Geschlecht und Bildungsstand gematcht. Mit dem Ziel eventuelle Unterschiede der Patientengruppen aufzudecken, wurden diese mit einem modifizierten Sternberg-Paradigma untersucht und es wurde ein anschließendes Interview mit Beurteilung des aktuellen psychopathologischen Befundes anhand standardisierter Skalen durchgeführt. Sowohl schizophrene Patienten als auch Patienten mit bipolar affektiver Störung zeigten im Vergleich zur Kontrollgruppe signifikante Beeinträchtigungen im visuell-räumlichen Arbeitsgedächtnis sowie im verbalen Rehearsal. Im direkten Vergleich zwischen den Patientengruppen waren die Defizite sowohl im verbalen Rehearsal als auch im visuell-räumlichen Arbeitsgedächtnis bei schizophrenen Patienten signifikant stärker ausgeprägt als bei bipolaren Patienten. Somit fanden sich zwischen den Patientengruppen lediglich quantitative Unterschiede in den Arbeitsgedächtnisdefiziten, während die qualitativen Defizitmuster keine diagnostische Spezifität aufwiesen. Der erhobene psychopathologische Befund korrelierte in keiner Diagnosegruppe mit den Testergebnissen, was darauf hinweisen könnte, dass die beobachteten Defizite Traitmerkmale beider Erkrankungen darstellen könnten.Deficits in cognitive abilities are often seen as a symptom of pychotic disorders. Previous investigations with study design have shown dysfuntions of the working memory of schizophrenic (Zilles et al., 2006) as well as of bipolar affected individuals (Gruber et al., 2005). There is no direct comparison of the diseases and their deficiency patterns to date. The objective of this doctoral thesis was to investigate the diagnostic specificity of the deficiency patterns observed in subareas of the working memory. In addition, correlations between the capacity of the working memory and the psychopathology were to be shown. 21 patients diagnosed schizophrenic and a further 21 patients diagnosed with bipolar affective disorder as well as 21 probands were investigated with regard to their verbal and their visual and spatial working memory. The groups were matched according to age, gender and educational level. Possible differences of the patient groups were to be discovered by means of a modified Sternberg paradigm as well as a subsequent interview with an evaluation of their current psychopathological findings based on standardized scales. Compared to the probands, both schizophrenic indivuals as well as patients suffering from bipolar affective disorder showed significant impairments in their visual and spatial working memory as well as in verbal rehearsal. Direct comparison of the patient groups showed that the deficiencies in verbal rehearsal as well as in the area of visual and spatial working memory is much more severe for schizophrenic than for bipolar individuals. Differences between the groups in terms of working memory deficiencies were hence only quantitative; qualitative defiency patterns did not show any diagnostic specificity. The psycho-pathological report did not correlate with the test results in any diagnosed group. This could mean that the observed deficiencies constitute trait characters of both diseases

The impact of ethnic background on ICU care and outcome in sepsis and septic shock - A retrospective multicenter analysis on 17,949 patients

Background: Previous studies have been inconclusive about racial disparities in sepsis. This study evaluated the impact of ethnic background on management and outcome in sepsis and septic shock. Methods: This analysis included 17,146 patients suffering from sepsis and septic shock from the multicenter eICU Collaborative Research Database. Generalized estimated equation (GEE) population-averaged models were used to fit three sequential regression models for the binary primary outcome of hospital mortality. Results: Non-Hispanic whites were the predominant group (n = 14,124), followed by African Americans (n = 1,852), Hispanics (n = 717), Asian Americans (n = 280), Native Americans (n = 146) and others (n = 830). Overall, the intensive care treatment and hospital mortality were similar between all ethnic groups. This finding was concordant in patients with septic shock and persisted after adjusting for patient-level variables (age, sex, mechanical ventilation, vasopressor use and comorbidities) and hospital variables (teaching hospital status, number of beds in the hospital). Conclusion: We could not detect ethnic disparities in the management and outcomes of critically ill septic patients and patients suffering from septic shock. Disparate outcomes among critically ill septic patients of different ethnicities are a public health, rather than a critical care challenge

Association of Chronic Covert Cerebral Infarctions and White Matter Hyperintensities With Atrial Fibrillation Detection on Post-Stroke Cardiac Rhythm Monitoring: A Cohort Study.

Background This study was conducted to explore the association of different phenotypes, count, and location of chronic covert brain infarctions (CBIs) with detection of atrial fibrillation (AF) on prolonged post-stroke cardiac rhythm monitoring (PCM). Methods and Results We conducted a cohort single-center study of consecutive first-ever ischemic stroke or transient ischemic attack patients undergoing PCM between January 2015 and December 2017. We blindly rated CBI phenotypes according to established definitions and white matter hyperintensities (WMHs) according to the age-related white matter changes rating scale. We used (multiple) regression models to assess the association of the imaging biomarkers and incident AF on PCM. A total of 795 patients (median [interquartile range]) aged 69 (57-78) years, 41% women, median National Institutes of Health Stroke Scale score 2 (0-5), median PCM duration 14 (7-14) days, and AF detection in 61 patients (7.7%) were included. On univariate analysis, WMHs (per point odds ratio, 1.35 [95% CI, 1.03-1.78]) but not CBIs (odds ratio, 0.90 [95% CI, 0.52-1.56]) were associated with AF detection. Neither CBI phenotype, count, nor location were associated with AF detection. After adjustment for age, hypertension, and stroke severity, neither increasing WMHs (per point adjusted odds ratio, 0.85 [95% CI, 0.60-1.20]) nor CBIs (adjusted odds ratio, 0.60 [95% CI, 0.33-1.09]) were independently associated with AF detection. Conclusions Although WMHs and CBIs represent surrogate biomarkers of vascular risk factors, neither WMHs nor CBIs, including their phenotypes, count, and location, were independently associated with AF detection on PCM. In patients with manifest ischemic stroke or transient ischemic attack, the presence of imaging biomarkers of chronic ischemic injury does not seem promising to further refine prediction tools for AF detection on PCM

Chronic cerebral infarctions and white matter lesions link to long-term survival after a first ischemic event: A cohort study.

BACKGROUND AND PURPOSE To investigate the association of different phenotypes, count, and locations of chronic covert brain infarctions (CBI) with long-term mortality in patients with first-ever manifest acute ischemic stroke (AIS) or transient ischemic attack (TIA). Additionally, to analyze their potential interaction with white matter hyperintensities (WMH) and predictive value in addition to established mortality scores. METHODS Single-center cohort study including consecutive patients with first-ever AIS or TIA with available MRI imaging from January 2015 to December 2017. Blinded raters adjudicated CBI phenotypes and WMH (age-related white matter changes score) according to established definitions. We compared Cox regression models including prespecified established predictors of mortality using Harrell's C and likelihood ratio tests. RESULTS A total of 2236 patients (median [interquartile range] age: 71 [59-80] years, 43% female, National Institutes of Health Stroke Scale: 2 [1-6], median follow-up: 1436 days, 21% death during follow-up) were included. Increasing WMH (per point adjusted Hazard Ratio [aHR] = 1.29 [1.14-1.45]), but not CBI (aHR = 1.21 [0.99-1.49]), were independently associated with mortality. Neither CBI phenotype, count, nor location was associated with mortality and there was no multiplicative interaction between CBI and WMH (p > .1). As compared to patients without CBI or WMH, patients with moderate or severe WMH and additional CBI had the highest hazards of death (aHR = 1.62 [1.23-2.13]). The Cox regression model including CBI and WMH had a small but significant increment in Harrell's C when compared to the model including 14 clinical variables (0.831 vs. 0.827, p < .001). DISCUSSION WMH represent a strong surrogate biomarker of long-term mortality in first-ever manifest AIS or TIA patients. CBI phenotypes, count, and location seem less relevant. Incorporation of CBI and WMH slightly improves predictive capacity of established risk scores

Reconstructing cancer genomes from paired-end sequencing data

<p>Abstract</p> <p>Background</p> <p>A cancer genome is derived from the germline genome through a series of somatic mutations. Somatic structural variants - including duplications, deletions, inversions, translocations, and other rearrangements - result in a cancer genome that is a scrambling of intervals, or "blocks" of the germline genome sequence. We present an efficient algorithm for reconstructing the block organization of a cancer genome from paired-end DNA sequencing data.</p> <p>Results</p> <p>By aligning paired reads from a cancer genome - and a matched germline genome, if available - to the human reference genome, we derive: (i) a partition of the reference genome into intervals; (ii) adjacencies between these intervals in the cancer genome; (iii) an estimated copy number for each interval. We formulate the Copy Number and Adjacency Genome Reconstruction Problem of determining the cancer genome as a sequence of the derived intervals that is consistent with the measured adjacencies and copy numbers. We design an efficient algorithm, called Paired-end Reconstruction of Genome Organization (PREGO), to solve this problem by reducing it to an optimization problem on an interval-adjacency graph constructed from the data. The solution to the optimization problem results in an Eulerian graph, containing an alternating Eulerian tour that corresponds to a cancer genome that is consistent with the sequencing data. We apply our algorithm to five ovarian cancer genomes that were sequenced as part of The Cancer Genome Atlas. We identify numerous rearrangements, or structural variants, in these genomes, analyze reciprocal vs. non-reciprocal rearrangements, and identify rearrangements consistent with known mechanisms of duplication such as tandem duplications and breakage/fusion/bridge (B/F/B) cycles.</p> <p>Conclusions</p> <p>We demonstrate that PREGO efficiently identifies complex and biologically relevant rearrangements in cancer genome sequencing data. An implementation of the PREGO algorithm is available at <url>http://compbio.cs.brown.edu/software/</url>.</p

Multivariable Prediction Model for Futile Recanalization Therapies in Patients With Acute Ischemic Stroke.

BACKGROUND AND OBJECTIVES Very poor outcome despite intravenous thrombolysis (IVT) and mechanical thrombectomy (MT) occurs in about 1 of 4 patients with ischemic stroke and is associated with a high logistic and economic burden. We aimed to develop and validate a multivariable prognostic model to identify futile recanalization therapies (FRT) in patients undergoing those therapies. MATERIALS AND METHODS Patients from a prospectively collected observational registry of a single academic stroke center treated with MT and/or IVT were included. The dataset was split into a training (N=1808, 80%) and internal validation (N=453, 20%) cohort. We used gradient boosted decision tree machine-learning models after k-NN imputation of 32 variables available at admission to predict FRT defined as modified Rankin-Scale (mRS) 5-6 at 3 months. We report feature importance, ability for discrimination, calibration and decision curve analysis. RESULTS 2261 patients with a median (IQR) age 75 years (64-83), 46% female, median NIHSS 9 (4-17), 34% IVT alone, 41% MT alone, 25% bridging were included. Overall 539 (24%) had FRT, more often in MT alone (34%) as compared to IVT alone (11%). Feature importance identified clinical variables (stroke severity, age, active cancer, prestroke disability), laboratory values (glucose, CRP, creatinine), imaging biomarkers (white matter hyperintensities) and onset-to-admission time as the most important predictors. The final model was discriminatory for predicting 3-month FRT (AUC 0.87, 95% CI 0.87-0.88) and had good calibration (Brier 0.12, 0.11-0.12). Overall performance was moderate (F1-score 0.63 ± 0.004) and decision curve analyses suggested higher mean net benefit at lower thresholds of treatment (up to 0.8). CONCLUSIONS This FRT prediction model can help inform shared decision making and identify the most relevant features in the emergency setting. While it might be particularly useful in low resource healthcare settings, incorporation of further multifaceted variables is necessary to further increase the predictive performance

Long‐Term Outcome and Quality of Life in Patients With Stroke Presenting With Extensive Early Infarction

Background The benefit of mechanical thrombectomy in patients with low Alberta Stroke Program Early Computed Tomography Score (ASPECTS) for short‐term outcomes is debatable and long‐term outcomes remain unknown. This retrospective, monocentric cohort study aimed to assess the association between reperfusion grade and the long‐term functional outcome measured with modified Rankin scale as well as the long‐term health‐related quality of life recorded at the last follow‐up in patients according to baseline ASPECTS (0–5 versus 6–10). Methods Deceased patients were identified from the Swiss population register and follow‐up telephone interviews were conducted with all surviving patients with stroke treated with mechanical thrombectomy between January 1, 2010, and December 31, 2018. Favorable outcome was defined as modified Rankin scale 0 to 3; health‐related quality of life was assessed using the 3‐level version of the EuroQol 5‐dimensional questionnaire. The EuroQol 5‐dimension utility index was calculated for statistical analyses. The reperfusion grade was core laboratory adjudicated using the expanded treatment in cerebral ischemia score. Adjusted odds ratios for the association between the reperfusion grade assessed by expanded treatment in cerebral ischemia and outcomes were calculated from multivariable logistic regression. Results Of the 1114 patients with available long‐term follow‐up records (median follow‐up, 3.67 years), 997 were included in the final analysis. Respectively, patients with low ASPECTS more often had complaints regarding mobility (67.1% versus 42.1%, P<0.001), self‐care (53.4% versus 31.2%, P<0.001), and usual activities (65.8% versus 41.4%, P<0.001) than patients with high ASPECTS, whereas reported pain/discomfort (65.7% versus 69.9%, P=0.49) and anxiety/depression (71.2% versus 78.9%, P=0.17) did not differ. In patients with low ASPECTS, increasing reperfusion grade was associated with a higher likelihood of long‐term favorable functional outcome (adjusted odds ratio, 1.43; 95% CI, 1.09–1.88 [P=0.01]) and health‐related quality of life (adjusted linear correlation coefficient, 0.05; 95% CI, 0.02–0.08) despite early extensive infarction. Conclusion Despite low baseline ASPECTS, a higher reperfusion grade results in better functional outcomes and may improve health‐related quality of life in the long term

Long-Term Effect of Mechanical Thrombectomy in Stroke Patients According to Advanced Imaging Characteristics.

PURPOSE Data on long-term effect of mechanical thrombectomy (MT) in patients with large ischemic cores (≥ 70 ml) are scarce. Our study aimed to assess the long-term outcomes in MT-patients according to baseline advanced imaging parameters. METHODS We performed a single-centre retrospective cohort study of stroke patients receiving MT between January 1, 2010 and December 31, 2018. We assessed baseline imaging to determine core and mismatch volumes and hypoperfusion intensity ratio (with low ratio reflecting good collateral status) using RAPID automated post-processing software. Main outcomes were cross-sectional long-term mortality, functional outcome and quality of life by May 2020. Analysis were stratified by the final reperfusion status. RESULTS In total 519 patients were included of whom 288 (55.5%) have deceased at follow-up (median follow-up time 28 months, interquartile range 1-55). Successful reperfusion was associated with lower long-term mortality in patients with ischemic core volumes ≥ 70 ml (adjusted hazard ratio (aHR) 0.20; 95% confidence interval (95% CI) 0.10-0.44) and ≥ 100 ml (aHR 0.26; 95% CI 0.08-0.87). The effect of successful reperfusion on long-term mortality was significant only in the presence of relevant mismatch (aHR 0.17; 95% CI 0.01-0.44). Increasing reperfusion grade was associated with a higher rate of favorable outcomes (mRS 0-3) also in patients with ischemic core volume ≥ 70 ml (aOR 3.58, 95% CI 1.64-7.83). CONCLUSION Our study demonstrated a sustainable benefit of better reperfusion status in patients with large ischemic core volumes. Our results suggest that patient deselection based on large ischemic cores alone is not advisable

Slater-Pauling Behavior of the Half-Ferromagnetic Full-Heusler Alloys

Using the full-potential screened Korringa-Kohn-Rostoker method we study the full-Heusler alloys based on Co, Fe, Rh and Ru. We show that many of these compounds show a half-metallic behavior, however in contrast to the half-Heusler alloys the energy gap in the minority band is extremely small. These full-Heusler compounds show a Slater-Pauling behavior and the total spin-magnetic moment per unit cell (M_t) scales with the total number of valence electrons (Z_t) following the rule: M_t=Z_t-24. We explain why the spin-down band contains exactly 12 electrons using arguments based on the group theory and show that this rule holds also for compounds with less than 24 valence electrons. Finally we discuss the deviations from this rule and the differences compared to the half-Heusler alloys.Comment: 10 pages, 8 figures, revised figure 3, new text adde