Enlighten-Research publications by members of the University of Glasgow http://eprints.gla.ac.uk Minimally invasive surgery with thrombolysis in intracerebral haemorrhage evacuation (MISTIE III): a randomised, controlled, open-label phase 3 trial with blinded endpoint

SUMMARY Background Craniotomy, when evaluated in trials, does not improve outcome after intracerebral haemorrhage (ICH). Whether minimally invasive catheter evacuation followed by thrombolysis is safe and can achieve a good functional outcome by removing clot is unknown. We investigated safety and efficacy of alteplase with minimally invasive surgery (MIS) in patients with intracerebral haemorrhage. Methods MISTIE was an international, randomized, open-label study and was done in 26 hospitals in the USA, Canada, the UK, and Germany. Patients (aged 18–80 years), with non-traumatic (spontaneous) ICH ≥20 mL were randomly allocated, centrally, to medical care or image-guided MIS plus rt-PA (0.3 mg or 1.0 mg every 8 hours for up to 9 doses) to remove clot using surgical aspiration followed with alteplase clot irrigation. The primary efficacy outcome was the adjusted dichotomized modified Rankin Scale (mRS) 0–3 vs 4–6 assessed at day 180 after symptom onset. Analysis was by intention to treat. (ClinicalTrials.gov number NCT00224770). Findings Between February 2, 2006 and April 8, 2013, 96 subjects were randomized and completed follow-up: 54 received treatment and 42 medical care. Primary safety outcomes: mortality, symptomatic bleeding, brain infections, as well as withdrawal of care, did not differ between groups. Asymptomatic hemorrhages were more common in the surgical group (3 (7%) vs. 12 (22%) p= 0.05) producing a difference of 15.1% (95% CI: 1.5% to 28.6%). The estimated absolute benefit, i.e., the unadjusted difference in observed proportions of all subjects with mRS 0–3 (33% vs 21%) at 180 days comparing MISPA vs. medical control, is 0.109 [95%CI: −0.088, 0.294; p=0.26], and is 0.162 [95%CI: 0.003, 0.323; p=0.05] after adjustment for potential imbalances in baseline severity between study arms (primary efficacy outcome). Interpretation MIS+rt-PA appears safe with an apparent advantage of better functional outcome at 180 days. Increased asymptomatic bleeding is a major cautionary finding. The MISTIE trial results, if replicable, could produce a meaningful functional benefit adding surgical management as a therapeutic strategy for ICH. Funding National Institute of Neurologic Disorders and Stroke, Genentech, and Codman.

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Arrestins are soluble cytoplasmic proteins that bind to G-protein-coupled receptors, thus switching off activation of the G protein and terminating the signalling pathway that triggers the cellular response. Although visual arrestin has been shown to quench the catalytic activity of photoexcited, phosphorylated rhodopsin in a reconstituted system, its role in the intact rod cell remains unclear because phosphorylation alone reduces the catalytic activity of rhodopsin. Here we have recorded photocurrents of rods from transgenic mice in which one or both copies of the arrestin gene were disrupted. Photoresponses were unaffected when arrestin expression was halved, indicating that arrestin binding is not rate limiting for recovery of the rod photoresponse, as it is in Drosophila. With arrestin absent, the flash response displayed a rapid partial recovery followed by a prolonged final phase. This behaviour indicates that an arrestin-independent mechanism initiates the quench of rhodopsin's catalytic activity and that arrestin completes the quench. The intensity dependence of the photoresponse in rods lacking arrestin further suggests that, although arrestin is required for normal signal termination, it does not participate directly in light adaptation.

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