Intravenous alteplase for stroke with unknown time of onset guided by advanced imaging: systematic review and meta-analysis of individual patient data

Background: Patients who have had a stroke with unknown time of onset have been previously excluded from thrombolysis. We aimed to establish whether intravenous alteplase is safe and effective in such patients when salvageable tissue has been identified with imaging biomarkers. Methods: We did a systematic review and meta-analysis of individual patient data for trials published before Sept 21, 2020. Randomised trials of intravenous alteplase versus standard of care or placebo in adults with stroke with unknown time of onset with perfusion-diffusion MRI, perfusion CT, or MRI with diffusion weighted imaging-fluid attenuated inversion recovery (DWI-FLAIR) mismatch were eligible. The primary outcome was favourable functional outcome (score of 0–1 on the modified Rankin Scale [mRS]) at 90 days indicating no disability using an unconditional mixed-effect logistic-regression model fitted to estimate the treatment effect. Secondary outcomes were mRS shift towards a better functional outcome and independent outcome (mRS 0–2) at 90 days. Safety outcomes included death, severe disability or death (mRS score 4–6), and symptomatic intracranial haemorrhage. This study is registered with PROSPERO, CRD42020166903. Findings: Of 249 identified abstracts, four trials met our eligibility criteria for inclusion: WAKE-UP, EXTEND, THAWS, and ECASS-4. The four trials provided individual patient data for 843 individuals, of whom 429 (51%) were assigned to alteplase and 414 (49%) to placebo or standard care. A favourable outcome occurred in 199 (47%) of 420 patients with alteplase and in 160 (39%) of 409 patients among controls (adjusted odds ratio [OR] 1·49 [95% CI 1·10–2·03]; p=0·011), with low heterogeneity across studies (I2=27%). Alteplase was associated with a significant shift towards better functional outcome (adjusted common OR 1·38 [95% CI 1·05–1·80]; p=0·019), and a higher odds of independent outcome (adjusted OR 1·50 [1·06–2·12]; p=0·022). In the alteplase group, 90 (21%) patients were severely disabled or died (mRS score 4–6), compared with 102 (25%) patients in the control group (adjusted OR 0·76 [0·52–1·11]; p=0·15). 27 (6%) patients died in the alteplase group and 14 (3%) patients died among controls (adjusted OR 2·06 [1·03–4·09]; p=0·040). The prevalence of symptomatic intracranial haemorrhage was higher in the alteplase group than among controls (11 [3%] vs two [<1%], adjusted OR 5·58 [1·22–25·50]; p=0·024). Interpretation: In patients who have had a stroke with unknown time of onset with a DWI-FLAIR or perfusion mismatch, intravenous alteplase resulted in better functional outcome at 90 days than placebo or standard care. A net benefit was observed for all functional outcomes despite an increased risk of symptomatic intracranial haemorrhage. Although there were more deaths with alteplase than placebo, there were fewer cases of severe disability or death. Funding: None

Luminescence microscopy for quality control of material and processing

A photoluminescence topography system is devised on the basis of an optical IR microscope. The system offers full versatility and simple operation of the microscope combined with the high sensitivity characteristic for luminescence, whose emission intensity varies strongly with crystal quality. Results obtained on InGaAsP/InP demonstrate the system's capabilities: in substrate characterization, luminescence microscopy turns out to be a nondestructive alternative to dislocation etching, but, in addition, it makes defects visible which are not revealed by etching. On epitaxial layers, with the technique, the correlations between various defects in the substrate and resulting layer quality are analyzed. As an application to process control, defect generation is investigated during thermal degradation. Two yet unknown degradation effects are discovered which develop even if protection by an Sn-P-melt is used

Increased myeloperoxidase plasma levels in patients with alzheimer's disease

Background: Increasing evidence supports the role of cardiovascular risk factors in the development of Alzheimer's disease (AD). Objective: In the present pilot study, we investigated plasma concentrations of myeloperoxidase (MPO) and its possible association with plasma amyloid-β (Aβ) 1-42/1-40 ratio in AD patients and elderly healthy controls. Methods: The study sample included 28 AD patients and 27 elderly individuals with a normal cognitive status as a control group. The Mini-Mental Status Examination was used to determine the global cognition. MPO, Aβ1-40, and Aβ1-42 plasma concentrations were measured by enzyme linked immunoabsorbent assays. Results: AD patients showed significantly higher plasma concentrations of MPO in comparison to healthy elderly controls (AD versus healthy elderly controls (mean ± SD): 132.8 ± 114.8 ng/mL versus 55.0 ± 42.6 ng/mL; p = 0.002). MPO plasma concentrations showed a significant positive correlation in the whole sample with the presence of AD (ρ = 0.428, p < 0.001) and its stage (ρ = 0.331; p = 0.013) as well as with plasma concentrations of Aβ1-42 (ρ = 0.406; p = 0.004) and Aβ1-42/1-40 ratio (ρ = 0.354; p = 0.013). In a binary logistic regression model, plasma MPO concentrations were independently associated with the presence of AD (p = 0.014). Conclusion: AD patients showed significantly increased plasma levels of MPO, which could be an important molecular link between atherosclerosis and AD. Further studies should evaluate whether MPO may also be a useful biomarker and potential new treatment target in AD. © 2014-IOS Press and the authors. All rights reserved

Next generation continuous wave photomixing THz systems

Telecom components and electro-optic THz phase control allow the realization of an integrated THz control unit. It enables to control any parameter of the THz signal in CW THz photomixing systems with standard electronic equipment. This significantly reduces size and cost of future CW THz systems

Integrated-optic polarisation convertor on (001)-InP substrate

A novel TE/TM convertor is proposed and demonstrated which is fabricated on (001)-InP substrate and can be integrated with TE-TM phase shifters to provide a general polarisation transformation. Some aspects of the technological realisation and first results are given; in a first attempt, a polarisation rotation of about 20 deg by 20 V could be demonstrated