Stickstoffmonoxid beschleunigt die Regeneration und mindert den Organschaden der „reduced-size”-Leber durch verbesserte hepatoarterielle Blutversorgung

Die Wirkung von Stickstoffmonoxid (NO) auf Hämodynamik, Parenchymschaden und Regeneration der Leber nach ausgedehnter Resektion wurde anhand von Parametern der hepatischen Makro- und Mikrohämodynamik und der hepatozytären Proliferation sowie Serummarkern des Leberschadens untersucht. NO wurde entweder pharmakologisch substituiert oder seine Freisetzung durch Blockade der NO-Synthasen gehemmt. Durch NO-Substitution gelang es, die leberarterielle Blutversorgung zu verbessern, den Leberschaden abzumildern und die Regeneration zu beschleunigen, ohne dabei den sinusoidalen Scherstress zu senken

Multiple Doses of Erythropoietin Impair Liver Regeneration by Increasing TNF-α, the Bax to Bcl-xL Ratio and Apoptotic Cell Death

BACKGROUND: Liver resection and the use of small-for-size grafts are restricted by the necessity to provide a sufficient amount of functional liver mass. Only few promising strategies to maximize liver regeneration are available. Apart from its erythropoiesis-stimulating effect, erythropoietin (EPO) has meanwhile been recognized as mitogenic, tissue-protective, and anti-apoptotic pleiotropic cytokine. Thus, EPO may support regeneration of hepatic tissue. METHODOLOGY: Rats undergoing 68% hepatectomy received daily either high dose (5000 IU/kg bw i.v.) or low dose (500 IU/kg bw i.v.) recombinant human EPO or equal amounts of physiologic saline. Parameters of liver regeneration and hepatocellular apoptosis were assessed at 24 h, 48 h and 5 d after resection. In addition, red blood cell count, hematocrit and serum EPO levels as well as plasma concentrations of TNF-alpha and IL-6 were evaluated. Further, hepatic Bcl-x(L) and Bax protein expression were analyzed by Western blot. PRINCIPAL FINDINGS: Administration of EPO significantly reduced the expression of PCNA at 24 h followed by a significant decrease in restitution of liver mass at day 5 after partial hepatectomy. EPO increased TNF-alpha levels and shifted the Bcl-x(L) to Bax ratio towards the pro-apoptotic Bax resulting in significantly increased hepatocellular apoptosis. CONCLUSIONS: Multiple doses of EPO after partial hepatectomy increase hepatocellular apoptosis and impair liver regeneration in rats. Thus, careful consideration should be made in pre- and post-operative recombinant human EPO administration in the setting of liver resection and transplantation

Recurrence of chronic subdural hematoma due to low-grade infection

Despite the high incidence and multitudes of operative techniques, the risk factors for chronic subdural hematoma (CSDH) recurrence are still under debate and a universal consensus on the pathophysiology is lacking. We hypothesized that clinically inapparent, a low-grade infection could be responsible for CSDH recurrence. This investigation is a single-center prospective observational study including patients with recurrent CSDH. In total, 44 patients with CSDH recurrence received an intraoperative swab-based microbiological test. The intraoperative swab revealed an inapparent low-grade hematoma infection in 29% of the recurrent CSDH cases. The majority (69%) of the identified germs belonged to the staphylococcus genus. We therefore, propose a novel potential pathophysiology for CSDH recurrence

Frailty in cerebellar ischemic stroke—The significance of temporal muscle thickness

While comprising only 2% of all ischemic strokes, cerebellar strokes are responsible for substantial morbidity and mortality due to their subtle initial presentation and the morbidity of posterior fossa swelling. Furthermore, low temporal muscle thickness (TMT) has recently been identified as a prognostic imaging parameter to assess patient frailty and outcome. We analyzed radiological and clinical data sets of 282 patients with cerebellar ischemic stroke. Our analysis showed a significant association between low TMT, reduced NIHSS and mRS at discharge (p = 0.035, p = 0.004), and reduced mRS at 12 months (p = 0.001). TMT may be used as a prognostic imaging marker and objective tool to assess outcomes in patients with cerebellar ischemic stroke

Improving 3D convolutional neural network comprehensibility via interactive visualization of relevance maps: Evaluation in Alzheimer's disease

Background: Although convolutional neural networks (CNN) achieve high diagnostic accuracy for detecting Alzheimer's disease (AD) dementia based on magnetic resonance imaging (MRI) scans, they are not yet applied in clinical routine. One important reason for this is a lack of model comprehensibility. Recently developed visualization methods for deriving CNN relevance maps may help to fill this gap. We investigated whether models with higher accuracy also rely more on discriminative brain regions predefined by prior knowledge. Methods: We trained a CNN for the detection of AD in N=663 T1-weighted MRI scans of patients with dementia and amnestic mild cognitive impairment (MCI) and verified the accuracy of the models via cross-validation and in three independent samples including N=1655 cases. We evaluated the association of relevance scores and hippocampus volume to validate the clinical utility of this approach. To improve model comprehensibility, we implemented an interactive visualization of 3D CNN relevance maps. Results: Across three independent datasets, group separation showed high accuracy for AD dementia vs. controls (AUC$\geq$0.92) and moderate accuracy for MCI vs. controls (AUC$\approx$0.75). Relevance maps indicated that hippocampal atrophy was considered as the most informative factor for AD detection, with additional contributions from atrophy in other cortical and subcortical regions. Relevance scores within the hippocampus were highly correlated with hippocampal volumes (Pearson's r$\approx$-0.86, p<0.001). Conclusion: The relevance maps highlighted atrophy in regions that we had hypothesized a priori. This strengthens the comprehensibility of the CNN models, which were trained in a purely data-driven manner based on the scans and diagnosis labels.Comment: 24 pages, 9 figures/tables, supplementary material, source code available on GitHu

Dangerous sweets: severe hypokalemia with rhabdomyolysis and tetraparesis from chronic consumption of licorice

Cardiac troponin is a specific and sensitive biomarker to identify and quantify myocardial injury. Myocardial injury is frequently detected after acute ischemic stroke and strongly associated with unfavorable outcomes. Concomitant acute coronary syndrome is only one of several possible differential diagnoses that may cause elevation of cardiac troponin after stroke. As a result, there are uncertainties regarding the correct interpretation and optimal management of stroke patients with myocardial injury in clinical practice. Elevation of cardiac troponin may occur as part of a 'Stroke-Heart Syndrome'. The term 'Stroke-Heart Syndrome' subsumes a clinical spectrum of cardiac complications after stroke including cardiac injury, dysfunction, and arrhythmia which may relate to disturbances of autonomic function and the brain-heart axis. In this review, we provide an up-to-date overview about prognostic implications, mechanisms, and management of elevated cardiac troponin levels in patients with acute ischemic stroke

Lethal form of a late-onset aquaporin-4 antibody-positive NMOSD related to the immune checkpoint inhibitor nivolumab

Purpose!#!To investigate the learning curve of vitreoretinal (VR) surgeons beginning training in retinal detachment (RD) surgery.!##!Methods!#!The files of all consecutive patients undergoing VR surgery for uncomplicated RD between Jan 2005 und Mar 2020 were retrospectively reviewed. Successful outcome was defined as no retinal redetachment within 3 months after surgery.!##!Results!#!Ten surgeons started their VR career during this period. Together, these 10 surgeons performed 3786 RD operations (mean 379; median 251; range 71-1053). Primary success rate after one operation was 90% (3420 of 3786). When starting to operate retinal detachments, VR surgeons had a primary success rate of about 80%. Redetachment rates steadily decreased and stabilized at just under 10% after about 200 operations. Beginners needed more than twice the time for the procedure compared to experienced surgeons. The individual learning curves varied widely. In our series, female surgeons seem to have a faster learning curve.!##!Conclusion!#!RD surgery performed by VR surgeons in training had acceptable results. With increasing experience, success rates continuously improve reaching stable levels after approximately 200 operations. The training of VR surgeons requires considerable resources

Significance of Temporal Muscle Thickness in Chronic Subdural Hematoma

Background: Reduced temporal muscle thickness (TMT) was verified as an independent negative prognostic parameter for outcome in brain tumor patients. Independent thereof, chronic subdural hematoma (CSDH) is a neurosurgical condition with high recurrence rates and unreliable risk models for poor outcome. Since sarcopenia was associated with poor outcome, we investigated the possible role of TMT and the clinical course of CSDH patients. Methods: This investigation is a single-center retrospective study on patients with CSDH. We analyzed the radiological and clinical data sets of 171 patients with surgically treated CSDH at a University Hospital from 2017 to 2020. Results: Our analysis showed a significant association between low-volume TMT and increased hematoma volume (p &lt; 0.001), poor outcome at discharge (p &lt; 0.001), and reduced performance status at 3 months (p &lt; 0.002). Conclusion: TMT may represent an objective prognostic parameter and assist the identification of vulnerable CSDH patients