Sequence-independent recognition of the amyloid structural motif by GFP protein family.

Cnidarian fluorescent protein (FP) derivatives such as GFP, mCherry, and mEOS2 have been widely used to monitor gene expression and protein localization through biological imaging because they are considered functionally inert. We demonstrate that FPs specifically bind amyloid fibrils formed from many natural peptides and proteins. FPs do not bind other nonamyloid fibrillar structures such as microtubules or actin filaments and do not bind to amorphous aggregates. FPs can also bind small aggregates formed during the lag phase and early elongation phase of fibril formation and can inhibit amyloid fibril formation in a dose-dependent manner. These findings suggest caution should be taken in interpreting FP-fusion protein localization data when amyloid structures may be present. Given the pathological significance of amyloid-related species in some diseases, detection and inhibition of amyloid fibril formation using FPs can provide insights on developing diagnostic tools.

Rupture of an Occult Intracranial Mycotic Aneurysm after Intravenous Thrombolysis with Recombinant Tissue Plasminogen Activator for Acute Ischemic Stroke.

BACKGROUND: The treatment of acute ischemic stroke with recombinant tissue plasminogen activator (rtPA) has become the mainstay of treatment, but its use carries a risk of subsequent intracranial hemorrhage (ICH). Guidelines have been developed to aid in the selection of the appropriate candidates to treat with rtPA to reduce this risk. We present a case of a stroke patient who was an appropriate candidate and was treated with rtPA who experienced a fatal subarachnoid hemorrhage due to a ruptured mycotic aneurysm (MA). CASE REPORT: A 51-year-old man presented to the Emergency Department with acute neurological symptoms concerning for acute ischemic stroke. His National Institutes of Health Stroke Scale score was 22. Emergent noncontrast head computed tomography (CT) revealed no sign of hemorrhage. The patient received intravenous rtPA, and about 1 h after the infusion was started, he had an acute deterioration in his mental status. Repeat CT scan revealed a large subarachnoid hemorrhage, and the patient was later found to have two intracranial aneurysms consistent with a ruptured MA that were related to his remote history of infective endocarditis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The majority of MAs are caused by infective endocarditis. In patients presenting with acute neurologic symptoms with a history of infective endocarditis, emergency physicians should strongly consider obtaining CT angiography to rule out MA prior to treating presumed acute ischemic stroke with rtPA.