Axons and their synapses distal to an injury undergo rapid Wallerian degeneration, but axons in the C57BL/WldS mouse are protected. The degenerative and protective mechanisms are unknown. We identified the protective gene, which encodes an N-terminal fragment of ubiquitination factor E4B (Ube4b) fused to nicotinamide mononucleotide adenylyltransferase (Nmnat), and showed that it confers a dose-dependent block of Wallerian degeneration. Transected distal axons survived for two weeks, and neuromuscular junctions were also protected. Surprisingly, the Wld protein was located predominantly in the nucleus, indicating an indirect protective mechanism. Nmnat enzyme activity, but not NAD+ content, was increased fourfold in WldS tissues. Thus, axon protection is likely to be mediated by altered ubiquitination or pyridine nucleotide metabolism.
Spreading depolarizations (SD) are waves of abrupt, near-complete breakdown of neuronal transmembrane ion gradients, are the largest possible pathophysiologic disruption of viable cerebral gray matter, and are a crucial mechanism of lesion development. Spreading depolarizations are increasingly recorded during multimodal neuromonitoring in neurocritical care as a causal biomarker providing a diagnostic summary measure of metabolic failure and excitotoxic injury. Focal ischemia causes spreading depolarization within minutes. Further spreading depolarizations arise for hours to days due to energy supply-demand mismatch in viable tissue. Spreading depolarizations exacerbate neuronal injury through prolonged ionic breakdown and spreading depolarization-related hypoperfusion (spreading ischemia). Local duration of the depolarization indicates local tissue energy status and risk of injury. Regional electrocorticographic monitoring affords even remote detection of injury because spreading depolarizations propagate widely from ischemic or metabolically stressed zones; characteristic patterns, including temporal clusters of spreading depolarizations and persistent depression of spontaneous cortical activity, can be recognized and quantified. Here, we describe the experimental basis for interpreting these patterns and illustrate their translation to human disease. We further provide consensus recommendations for electrocorticographic methods to record, classify, and score spreading depolarizations and associated spreading depressions. These methods offer distinct advantages over other neuromonitoring modalities and allow for future refinement through less invasive and more automated approaches.
The results indicate an antiproteinuric and antifibrotic nephroprotective effect of ramipril in COL4A3 -/- mice is mediated by down-regulation of TGF-beta1. This effect in mice is enhanced by initiation of therapy during pre-symptomatic disease. The data in COL4A3 -/- mice as an animal-model for Alport syndrome suggest that ramipril might as well delay renal failure in humans with AS. Early diagnosis and preemptive treatment also may be crucial in humans.
Focal brain damage after aneurysmal subarachnoid haemorrhage predominantly results from intracerebral haemorrhage, and early and delayed cerebral ischaemia. The prospective, observational, multicentre, cohort, diagnostic phase III trial, DISCHARGE-1, primarily investigated whether the peak total spreading depolarization-induced depression duration of a recording day during delayed neuromonitoring (delayed depression duration) indicates delayed ipsilateral infarction. Consecutive patients (n = 205) who required neurosurgery were enrolled in six university hospitals from September 2009 to April 2018. Subdural electrodes for electrocorticography were implanted. Participants were excluded on the basis of exclusion criteria, technical problems in data quality, missing neuroimages or patient withdrawal (n = 25). Evaluators were blinded to other measures. Longitudinal MRI, and CT studies if clinically indicated, revealed that 162/180 patients developed focal brain damage during the first 2 weeks. During 4.5 years of cumulative recording, 6777 spreading depolarizations occurred in 161/180 patients and 238 electrographic seizures in 14/180. Ten patients died early; 90/170 developed delayed infarction ipsilateral to the electrodes. Primary objective was to investigate whether a 60-min delayed depression duration cut-off in a 24-h window predicts delayed infarction with >0.60 sensitivity and >0.80 specificity, and to estimate a new cut-off. The 60-min cut-off was too short. Sensitivity was sufficient [= 0.76 (95% confidence interval: 0.65–0.84), P = 0.0014] but specificity was 0.59 (0.47–0.70), i.e. <0.80 (P < 0.0001). Nevertheless, the area under the receiver operating characteristic (AUROC) curve of delayed depression duration was 0.76 (0.69–0.83, P < 0.0001) for delayed infarction and 0.88 (0.81–0.94, P < 0.0001) for delayed ischaemia (reversible delayed neurological deficit or infarction). In secondary analysis, a new 180-min cut-off indicated delayed infarction with a targeted 0.62 sensitivity and 0.83 specificity. In awake patients, the AUROC curve of delayed depression duration was 0.84 (0.70–0.97, P = 0.001) and the prespecified 60-min cut-off showed 0.71 sensitivity and 0.82 specificity for reversible neurological deficits. In multivariate analysis, delayed depression duration (β = 0.474, P < 0.001), delayed median Glasgow Coma Score (β = −0.201, P = 0.005) and peak transcranial Doppler (β = 0.169, P = 0.016) explained 35% of variance in delayed infarction. Another key finding was that spreading depolarization-variables were included in every multiple regression model of early, delayed and total brain damage, patient outcome and death, strongly suggesting that they are an independent biomarker of progressive brain injury. While the 60-min cut-off of cumulative depression in a 24-h window indicated reversible delayed neurological deficit, only a 180-min cut-off indicated new infarction with >0.60 sensitivity and >0.80 specificity. Although spontaneous resolution of the neurological deficit is still possible, we recommend initiating rescue treatment at the 60-min rather than the 180-min cut-off if progression of injury to infarction is to be prevented.
Direct treatment costs caused by candidemia in German intensive care unit (ICU) patients are currently unknown. We analyzed treatment costs and the impact of antifungal drug choice. Comprehensive data of patients who had at least one episode of candidemia while staying in the ICU between 01/2005 and 12/2010 were documented in a database using the technology of the Cologne Cohort of Neutropenic Patients (CoCoNut). A detailed analysis of all disease-associated treatment costs was performed. Patients treated with echinocandins (i.e., anidulafungin, caspofungin, micafungin) or fluconazole were analyzed separately and compared. Forty-one and 64 patients received echinocandins and fluconazole, respectively. The mean Acute Physiology and Chronic Health Evaluation (APACHE) IV score was 114 (95 % confidence interval [CI]: 106-122) vs. 95 (95 % CI: 90-101, p = <0.001). Twenty-three (56 %) and 33 (52 %, p = 0.448) patients survived hospitalization, while 17 (41 %) and 22 (34 %, p = 0.574) survived one year after diagnosis. In the echinocandin and fluconazole groups, the mean costs per patient of ICU treatment were
Objective: Intracranial infectious aneurysms (IIAs) are a rare clinical entity without a definitive treatment guideline. In this study, we evaluate the treatment options of these lesions based on our own clinical experience and review the current knowledge of therapy as portrayed in the literature. Methods: We conducted a single-center retrospective analysis of all patients with an IIA and performed a systematic review of the literature using the MEDLINE database. We undertook a comprehensive literature search using the OVID gateway of the MEDLINE database (1950-October 2015) using the following keywords (in combination): ‘infectious', ‘mycotic', ‘cerebral aneurysm', ‘intracranial aneurysm'. 1,721 potentially relevant abstracts were identified and 63 studies were selected for full review. The studies were analysed regarding ruptured versus unruptured aneurysms, aneurysm localization and treatment, as well as clinical and radiological outcome. Results: Our institutional series consisted of 6 patients (median age 57 [32-76]) treated between 2011 and 2015. All patients presented with ruptured IIAs located on the middle cerebral artery (MCA, 5 patients) and anterior cerebral artery (ACA, 1 patient). Five patients were treated by clipping and resecting the aneurysm, 1 patient underwent coiling. All patients received antibiotic therapy and 1 patient died. We further identified 814 patients (median age 35.5 [0-81]) in 63 studies. Locations of the aneurysms were mentioned in 55 studies. The most frequent locations of the aneurysms were: MCA (63.5%), posterior cerebral artery (14%), ACA (9.0%) and others (13.5%). Treatment for IIAs was described in 62 studies: antibiotic treatment (56.1%), a combination of antibiotics and surgery (20.9%) or antibiotics and endovascular treatment (23.0%). Outcome was mentioned in 82.4% of the patients with a mortality rate of 16.8%. An evaluation of treatment outcome was limited due to the heterogeneity of patients in the published case series. Conclusion: Antibiotic therapy of patients with IIA is mandatory. However, due to the complexity of the disease and its accompanying comorbidities, a general treatment algorithm could not be defined. Analogous to non-mycotic aneurysms, further treatment decisions require an interdisciplinary approach involving neurosurgeons, interventionists and infectious disease specialists.
S U M M A R YImmunogold labeling on samples of isolated perfused rat hearts embedded by an innovative low-temperature LR White procedure provided detailed insight into the interaction of caveolin-1 and endothelial NOS in myocardial capillary endothelium at the subcellular level. Separately, the localization of caveolin-1 and eNOS at caveolae under steady state conditions was visualized. A double-labeling experiment supported their close co-localization. Short-term bradykinin stimulation caused a detectable dissociation of eNOS from caveolin and its redistribution to different cell compartments, whereas caveolin itself remained stationary at caveolae. Morphometric analysis revealed that more than 80% of detectable eNOS was co-localized with caveolin-1 at caveolae under control conditions. After brief stimulation for 2 min with 10 Ϫ 7 M bradykinin, only 26% of the eNOS signals were associated with caveolin-1 and randomly distributed over the endothelial cells. After stimulation, eNOS was found at the plasmalemmal and intracellular membranes, freely in the cytoplasm, and at outer mitochondrial membranes. P revious biochemical investigation showed that endothelial nitric oxide synthase (eNOS, NOSIII) interacts directly with caveolin-1 in its inactive form in resting endothelial cells (Garcia-Cardena et al. 1997;Ju et al. 1997) and is redistributed by adequate stimuli such as bradykinin treatment (Prabhakar et al. 1998). Therefore, eNOS activation and NO release are believed to represent a competitive interaction between the inactive eNOS scaffolding caveolin and the metabolic active Ca 2 ϩ -calmodulin-NOS complex (Michel et al. 1997;Feron et al. 1998b). This model of caveolin as a scaffold/chaperone for inactive forms of several signal transduction proteins is likely to be a general paradigm of cell signaling organization .We recently explained alterations in the immunohistochemical detection of eNOS in ischemic and bradykinin-stimulated rat hearts by conformational changes of eNOS epitopes while interacting with other proteins, especially caveolin (Bloch et al. 2001). To date, no experimental approaches have been undertaken to investigate the caveolin-eNOS interaction at the subcellular level; hence, light microscopic work has been done (Segal et al. 1999).In a variation on the post-embedding method of Berryman and Rodewald (1990), we performed a lowtemperature LR White embedding procedure that delivers tissue preservation close to that of standard electron microscopy. We were able to make observations regarding the subcellular distribution of eNOS and caveolin-1 using structural caveolae in cells of intact tissue as a reference landmark, providing an independent method of protein interaction in addition to commonly applied biochemical techniques.Rat hearts were harvested from male Wistar rats after CO 2 anesthesia and cervical dislocation. After 25 min of retrograde perfusion via the aorta according to the Langendorff technique, further perfusion for 2 min with 10 Ϫ 7 M/liter bradykinin (Sigma; St Louis, MO) or no...
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