[Abstract unavailable

Real-time quaking-induced conversion (RT-QuIC) allows the amplification of miniscule amounts of scrapie prion protein (PrPSc). Recent studies applied the RT-QuIC methodology to cerebrospinal fluid (CSF) for diagnosing human prion diseases. However, to date, there has not been a formal multi-centre assessment of the reproducibility, validity and stability of RT-QuIC in this context, an indispensable step for establishment as a diagnostic test in clinical practice. In the present study, we analysed CSF from 110 prion disease patients and 400 control patients using the RT-QuIC method under various conditions. In addition, “blinded” ring trials between different participating sites were performed to estimate reproducibility. Using the previously established cut-off of 10,000 relative fluorescence units (rfu), we obtained a sensitivity of 85 % and a specificity of 99 %. The multi-centre inter-laboratory reproducibility of RT-QuIC revealed a Fleiss’ kappa value of 0.83 (95 % CI: 0.40–1.00) indicating an almost perfect agreement. Moreover, we investigated the impact of short-term CSF storage at different temperatures, long-term storage, repeated freezing and thawing cycles and the contamination of CSF with blood on the RT-QuIC seeding response. Our data indicated that the PrPSc seed in CSF is stable to any type of storage condition but sensitive to contaminations with blood (>1250 erythrocytes/μL), which results in a false negative RT-QuIC response. Fresh blood-contaminated samples (3 days) can be rescued by removal of erythrocytes. The present study underlines the reproducibility and high stability of RT-QuIC across various CSF storage conditions with a remarkable sensitivity and specificity, suggesting RT-QuIC as an innovative and robust diagnostic method.Electronic supplementary materialThe online version of this article (doi:10.1007/s12035-015-9133-2) contains supplementary material, which is available to authorized users.

BackgroundDespite the recent acceptance of thrombectomy as the standard of care in patients with acute anterior circulation stroke, the benefits of thrombectomy remain uncertain for patients with acute basilar artery occlusion (BAO). This study aimed to evaluate the effectiveness and safety of thrombectomy and to identify predictors of outcomes in a large cohort of patients with acute BAO.Methods and ResultsThis study included 212 consecutive patients with acute BAO who underwent either stent‐retriever or contact aspiration thrombectomy as the first‐line approach between January 2011 and August 2017 at 3 stroke centers. Clinical and radiologic data were prospectively collected and stored in a database at each center. Multivariable ordinal logistic regression was performed to assess the association between each characteristic and 90‐day modified Rankin scale scores. Reperfusion was successful in 91.5% (194/212) of patients; 44.8% (95/212) of patients achieved 90‐day modified Rankin scale 0 to 2. The symptomatic hemorrhage rate was 1.9% (4/212) and mortality was 16% (34/212). In a multivariable ordinal regression, younger age, lower National Institute of Health stroke scale on admission, and absence of diabetes mellitus and parenchymal hematoma were significantly associated with a favorable shift in the overall distribution of 90‐day modified Rankin scale scores. Treatment outcomes were similar between patients who received stent‐retriever thrombectomy and contact aspiration thrombectomy as the first‐line technique.ConclusionsEndovascular thrombectomy was effective and safe for treating patients with acute BAO. Age, the baseline National Institute of Health stroke scale, diabetes mellitus, and parenchymal hematoma were associated with better outcomes. This study showed no superiority of the stent‐retriever over the aspiration thrombectomy for treating acute BAO.

Hepatitis C virus NS5B protein is an RNA-dependent RNA polymerase. To investigate the properties and function of this protein, we have expressed the NS5B protein in insect and mammalian cells. NS5B was found to be present as fine speckles in the cytoplasm, particularly concentrated in the perinuclear region, suggesting its association with the nuclear membrane, the endoplasmic reticulum, or the Golgi complex. This conclusion was supported by the biochemical demonstration that NS5B was associated with the membranes in the cells. Furthermore, it was shown that NS5B protein is a phosphoprotein. These properties may be related to its function as an RNA polymerase.

Background and Purpose Acute intracranial occlusion can be associated with “in situ thrombo-occlusion” in relation to pre-existing intracranial atherosclerotic disease (ICAD). We aimed to assess residual stenosis at the site of a target arterial lesion (TAL) to determine whether residual stenosis at the TAL is associated with underlying ICAD. Methods One hundred and sixty-three patients who underwent endovascular therapy for M1 middle cerebral artery occlusion and achieved angiographic reperfusion were selected for analysis. The presence of residual stenosis at the TAL was classified using the Arterial Occlusive Lesion (AOL) scale at post-procedural angiography, and the severity of stenosis was grouped into none, mild (<50%), moderate (50–69%), severe (70–99%), and occlusion on post-procedural and follow-up angiography. We also recorded the incidence of instant reocclusion occurring during the procedure and delayed reocclusion detected on follow-up angiography. Results Seventy-four patients (45.5%) showed target arterial residual stenosis (AOL 2). As to the TAL etiology, 40 patients were classified into in situ thrombo-occlusion (54.1% of AOL 2 and 24.5% of M1 occlusion). The occurrence of instant or delayed reocclusion was independently associated with a low chance of favorable 3-month outcome. Further, the occurrence of delayed reocclusion was associated with excellent pretreatment collateral-flow and early neurological worsening, but not the severity of residual stenosis at the TAL. Conclusions In population with a high prevalence of ICAD, residual stenosis may be attributed to in situ thrombo-occlusion with underlying ICAD about 25% of cases, hindering functional recovery via the occurrence of instant or delayed reocclusion.