454 research outputs found

    Dimethylethanolamine Decreases Epileptiform Activity in Acute Human Hippocampal Slices in vitro

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    Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy with about 30% of patients developing pharmacoresistance. These patients continue to suffer from seizures despite polytherapy with antiepileptic drugs (AEDs) and have an increased risk for premature death, thus requiring further efforts for the development of new antiepileptic therapies. The molecule dimethylethanolamine (DMEA) has been tested as a potential treatment in various neurological diseases, albeit the functional mechanism of action was never fully understood. In this study, we investigated the effects of DMEA on neuronal activity in single-cell recordings of primary neuronal cultures. DMEA decreased the frequency of spontaneous synaptic events in a concentration-dependent manner with no apparent effect on resting membrane potential (RMP) or action potential (AP) threshold. We further tested whether DMEA can exert antiepileptic effects in human brain tissue ex vivo. We analyzed the effect of DMEA on epileptiform activity in the CA1 region of the resected hippocampus of TLE patients in vitro by recording extracellular field potentials in the pyramidal cell layer. Epileptiform burst activity in resected hippocampal tissue from TLE patients remained stable over several hours and was pharmacologically suppressed by lacosamide, demonstrating the applicability of our platform to test antiepileptic efficacy. Similar to lacosamide, DMEA also suppressed epileptiform activity in the majority of samples, albeit with variable interindividual effects. In conclusion, DMEA might present a new approach for treatment in pharmacoresistant TLE and further studies will be required to identify its exact mechanism of action and the involved molecular targets

    Utilization of Epidural Electrodes as a Diagnostic Tool in Intractable Epilepsy—A Technical Note

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    The utilization of epidural electrodes in the preoperative evaluation of intractable epilepsy is a valuable but underrepresented tool. In recent years, we have adapted the use of cylindrical epidural 1-contact electrodes (1-CE) instead of Peg electrodes. 1-CEs are more versatile since their explantation is a possible bedside procedure. Here we report our experience with 1-CEs as well as associated technical nuances. This retrospective analysis included 56 patients with intractable epilepsy who underwent epidural electrode placement for presurgical evaluation at the Department of Neurosurgery at the Charité University Hospital from September 2011 to July 2021. The median age at surgery was 36.3 years (range: 18–87), with 30 (53.6%) female and 26 (46.4%) male patients. Overall, 507 electrodes were implanted: 93 Fo electrodes, 33 depth electrodes, and 381 epidural electrodes, with a mean total surgical time of 100.5 ± 38 min and 11.8 ± 5 min per electrode. There was a total number of 24 complications in 21 patients (8 Fo electrode dislocations, 6 CSF leaks, 6 epidural electrode dislocations or malfunction, 3 wound infections, and 2 hemorrhages); 11 of these required revision surgery. The relative electrode complication rates were 3/222 (1.4%) in Peg electrodes and 3/159 (1.9%) in 1-CE. In summary, epidural recording via 1-CE is technically feasible, harbours an acceptable complication rate, and adequately replaces Peg electrodes

    RNase A Inhibits Formation of Neutrophil Extracellular Traps in Subarachnoid Hemorrhage

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    Background: Subarachnoid hemorrhage (SAH) caused by rupture of an intracranial aneurysm, is a life-threatening emergency that is associated with substantial morbidity and mortality. Emerging evidence suggests involvement of the innate immune response in secondary brain injury, and a potential role of neutrophil extracellular traps (NETs) for SAH-associated neuroinflammation. In this study, we investigated the spatiotemporal patterns of NETs in SAH and the potential role of the RNase A (the bovine equivalent to human RNase 1) application on NET burden. Methods: A total number of n=81 male C57Bl/6 mice were operated utilizing a filament perforation model to induce SAH, and Sham operation was performed for the corresponding control groups. To confirm the bleeding and exclude stroke and intracerebral hemorrhage, the animals received MRI after 24h. Mice were treated with intravenous injection of RNase A (42 mu g/kg body weight) or saline solution for the control groups, respectively. Quadruple-immunofluorescence (IF) staining for cell nuclei (DAPI), F-actin (phalloidin), citrullinated H3, and neurons (NeuN) was analyzed by confocal imaging and used to quantify NET abundance in the subarachnoid space (SAS) and brain parenchyma. To quantify NETs in human SAH patients, cerebrospinal spinal fluid (CSF) and blood samples from day 1, 2, 7, and 14 after bleeding onset were analyzed for double-stranded DNA (dsDNA) via Sytox Green. Results: Neutrophil extracellular traps are released upon subarachnoid hemorrhage in the SAS on the ipsilateral bleeding site 24h after ictus. Over time, NETs showed progressive increase in the parenchyma on both ipsi- and contralateral site, peaking on day 14 in periventricular localization. In CSF and blood samples of patients with aneurysmal SAH, NETs also increased gradually over time with a peak on day 7. RNase application significantly reduced NET accumulation in basal, cortical, and periventricular areas. Conclusion: Neutrophil extracellular trap formation following SAH originates in the ipsilateral SAS of the bleeding site and spreads gradually over time to basal, cortical, and periventricular areas in the parenchyma within 14days. Intravenous RNase application abrogates NET burden significantly in the brain parenchyma, underpinning a potential role in modulation of the innate immune activation after SAH

    Surgery in intractable epilepsy - physicians' recommendations and patients' decisions

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    Objectives: To identify demographic and clinical variables independently associated with patients' decisions against their physicians' recommendations for resective epilepsy surgery or further scalp video-EEG monitoring (sca-VEM), semi-invasive (sem-)VEM with foramen ovale and/or peg electrodes, and invasive (in-)VEM. Methods: Consecutive patients, who underwent presurgical assessment with at least one sca-VEM between 2010 and 2014, were included into this retrospective analysis. Multivariate analysis was used to identify independent variables associated with patients' decisions. Results: Within the study period, 352 patients underwent 544 VEM sessions comprising 451 sca-, 36 sem-, and 57 in-VEMs. Eventually, 96 patients were recommended resective surgery, and 106 were ineligible candidates; 149 patients denied further necessary VEMs; thus, no decision could be made. After sca- or additional sem-VEM, nine out of 51 eligible patients (17.6%) rejected resection. One hundred and ten patients were recommended in-VEM, 52 of those (47.2%) declined. Variables independently associated with rejection of in-VEM comprised intellectual disability (OR 4.721, 95% CI 1.047-21.284), extratemporal focal aware non-motor seizures ("aura") vs. no "aura" (OR 0.338, 95% CI 0.124-0.923), and unilateral or bilateral vs. no MRI lesion (OR 0.248, 95% CI 0.100-0.614 and 0.149, 95% CI 0.027-0.829, respectively). Conclusions: During and after presurgical evaluation, patients with intractable focal epilepsy declined resections and intracranial EEGs, as recommended by their epileptologists, in almost 20% and 50% of cases. This calls for early and thorough counseling of patients on risks and benefits of epilepsy surgery. Future prospective studies should ask patients in depth for specific reasons why they decline their physicians' recommendations

    The IPCC’s reductive Common Era temperature history

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    J.E. acknowledges support by the Gutenberg Research College, J.E. M.T. and U.B. by the project AdAgrif (CZ.02.01.01/00/22_008/0004635) and ERC (AdG 882727), J.E.S. by the US NSF (OISE-1743738, AGS-2101214 and AGS-2303352), K.J.A. by the US NSF (AGS-1803946 and AGS-2102993), K.A. by the ARC (FT200100102), R.D. by the US NSF (OPP-2112314, OPP-2124885, and AGS-2102759), S.G and M. Stoffel by the SNSF (Sinergia CRSII5_183571), F.C.L. by the SRC (grant no. 2018-01272), Marianne and Marcus Wallenberg Foundation (grant no. MMW 2022-0114) and Swedish Collegium for Advanced Study (Pro Futura Scientia XIII Fellow), LS by the German Research Foundation (SCHN 1645/1-1), M. Sigl by the ERC (CoG 820047), and R.W. by the NSF-NERC (NE/W007223/1).Common Era temperature variability has been a prominent component in Intergovernmental Panel on Climate Change reports over the last several decades and was twice featured in their Summary for Policymakers. A single reconstruction of mean Northern Hemisphere temperature variability was first highlighted in the 2001 Summary for Policymakers, despite other estimates that existed at the time. Subsequent reports assessed many large-scale temperature reconstructions, but the entirety of Common Era temperature history in the most recent Sixth Assessment Report of the Intergovernmental Panel on Climate Change was restricted to a single estimate of mean annual global temperatures. We argue that this focus on a single reconstruction is an insufficient summary of our understanding of temperature variability over the Common Era. We provide a complementary perspective by offering an alternative assessment of the state of our understanding in high-resolution paleoclimatology for the Common Era and call for future reports to present a more accurate and comprehensive assessment of our knowledge about this important period of human and climate history.Peer reviewe

    Intrauterine Growth Retarded Progeny of Pregnant Sows Fed High Protein:Low Carbohydrate Diet Is Related to Metabolic Energy Deficit

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    High and low protein diets fed to pregnant adolescent sows led to intrauterine growth retardation (IUGR). To explore underlying mechanisms, sow plasma metabolite and hormone concentrations were analyzed during different pregnancy stages and correlated with litter weight (LW) at birth, sow body weight and back fat thickness. Sows were fed diets with low (6.5%, LP), adequate (12.1%, AP), and high (30%, HP) protein levels, made isoenergetic by adjusted carbohydrate content. At −5, 24, 66, and 108 days post coitum (dpc) fasted blood was collected. At 92 dpc, diurnal metabolic profiles were determined. Fasted serum urea and plasma glucagon were higher due to the HP diet. High density lipoprotein cholesterol (HDLC), %HDLC and cortisol were reduced in HP compared with AP sows. Lowest concentrations were observed for serum urea and protein, plasma insulin-like growth factor-I, low density lipoprotein cholesterol, and progesterone in LP compared with AP and HP sows. Fasted plasma glucose, insulin and leptin concentrations were unchanged. Diurnal metabolic profiles showed lower glucose in HP sows whereas non-esterified fatty acids (NEFA) concentrations were higher in HP compared with AP and LP sows. In HP and LP sows, urea concentrations were 300% and 60% of AP sows, respectively. Plasma total cholesterol was higher in LP than in AP and HP sows. In AP sows, LW correlated positively with insulin and insulin/glucose and negatively with glucagon/insulin at 66 dpc, whereas in HP sows LW associated positively with NEFA. In conclusion, IUGR in sows fed high protein∶low carbohydrate diet was probably due to glucose and energy deficit whereas in sows with low protein∶high carbohydrate diet it was possibly a response to a deficit of indispensable amino acids which impaired lipoprotein metabolism and favored maternal lipid disposal

    The Function of Hypoxia-Inducible Factor (HIF) Is Independent of the Endoplasmic Reticulum Protein OS-9

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    The protein “amplified in osteosarcoma-9” (OS-9) has been shown previously to interact with the prolyl hydroxylases PHD2 and PHD3. These enzymes initiate oxygen-dependent degradation of the α-subunit of hypoxia-inducible factor (HIF), a transcription factor that adapts cells to insufficient oxygen supply (hypoxia). A new model has been proposed where OS-9 triggers PHD dependent degradation of HIF-α. It was the aim of our study to define the molecular mode of action of OS-9 in the regulation of PHD and HIF activity. Although initial co-immunoprecipitation experiments confirmed physical interaction between OS-9 and PHD2, neither overexpression nor lentiviral inhibition of OS-9 expression affected HIF regulation. Subcellular localization experiments revealed a distinct reticular staining pattern for OS-9 while PHD2 was mainly localized in the cytoplasm. Further cell fractionation experiments and glycosylation tests indicated that OS-9 is a luminal ER protein. In vivo protein interaction analysis by fluorescence resonance energy transfer (FRET) showed no significant physical interaction of overexpressed PHD2-CFP and OS-9-YFP. We conclude that OS-9 plays no direct functional role in HIF degradation since physical interaction of OS-9 with oxygen sensing HIF prolyl hydroxylases cannot occur in vivo due to their different subcellular localization

    Meta-analysis of multidecadal biodiversity trends in Europe

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    Local biodiversity trends over time are likely to be decoupled from global trends, as local processes may compensate or counteract global change. We analyze 161 long-term biological time series (15-91 years) collected across Europe, using a comprehensive dataset comprising similar to 6,200 marine, freshwater and terrestrial taxa. We test whether (i) local long-term biodiversity trends are consistent among biogeoregions, realms and taxonomic groups, and (ii) changes in biodiversity correlate with regional climate and local conditions. Our results reveal that local trends of abundance, richness and diversity differ among biogeoregions, realms and taxonomic groups, demonstrating that biodiversity changes at local scale are often complex and cannot be easily generalized. However, we find increases in richness and abundance with increasing temperature and naturalness as well as a clear spatial pattern in changes in community composition (i.e. temporal taxonomic turnover) in most biogeoregions of Northern and Eastern Europe. The global biodiversity decline might conceal complex local and group-specific trends. Here the authors report a quantitative synthesis of longterm biodiversity trends across Europe, showing how, despite overall increase in biodiversity metric and stability in abundance, trends differ between regions, ecosystem types, and taxa.peerReviewe
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