ABSTRACT
The presence of patent foramen ovale (PFO) is noted to be higher in patients with a history of cryptogenic stroke, especially in younger patients <55 years old. PFO has shown to be a relatively common occurrence in the population, in 25-30% of individuals. Our case is one of right middle cerebral artery (MCA) infarct due to thromboembolism from a PFO. A 44-year-old white right-handed woman with a history of insulin-dependent diabetes mellitus, hyperlipidemia, hypertension, tobacco abuse, and obesity presented with complaints of new onset headache, dizziness, and left arm and leg heaviness, suspicious for right MCA lesion. She was admitted with stroke-like symptoms, National Institute of Health Stroke Scale (NIHSS) of 8 for left-sided weakness, sensory loss, and ataxia. Computed tomography (CT) head was negative for hemorrhage, and there was no large vessel occlusion on computed tomography angiogram (CTA). She was aspirin-loaded and started on dual antiplatelet therapy (DAPT). Ultimately, brain MRI showed right MCA ischemic stroke, and full stroke assessment showed small PFO on the transthoracic echocardiogram (TTE). She was continued on aspirin and clopidogrel DAPT for 21 days, followed by aspirin monotherapy. Unfortunately, her left-sided deficits did not completely resolve, and she was discharged to rehab. She has had recurrent stroke and is currently considered for PFO repair. A patient's past medical history, last known well time, and exacting symptoms with the NIHSS at onset should be thoroughly obtained at the first medical contact. CT imaging should rule out hemorrhage prior to prompt antiplatelet or thrombolytic administration. In addition, when there are absence of risk factors and the cause remains unknown, it is especially important to obtain TTE with Doppler to assess for right-to-left atrial shunt indicating PFO and potentially contributing thromboembolic etiology. Stroke precautions involving swallow evaluation, aspiration and fall precautions, serial NIH for changes, sequence of imaging, and physical therapy (PT) and occupational therapy (OT) should entail. A stroke neurologist should also be involved at presentation, with the stroke alert protocol shown to improve patient outcomes. Additional risk factors, such as PFO, should also be addressed, often with a multimodal team of providers and careful weight given to the risks and benefits of invasive procedure.
ABSTRACT
An industrially important enzyme, Candida antarctica lipase B (CalB), was modified with a range of functional polymers including hydrophilic, hydrophobic, anionic, and cationic character using a "grafting to" approach. We determined the impact of polymer chain length on CalB activity by synthesizing biohybrids of CalB with each polymer at three different chain lengths, using reversible addition-fragmentation chain transfer (RAFT) polymerization. The activity of CalB in both aqueous and aqueous-organic media mixtures was significantly enhanced for acrylamide (Am) and N,N-dimethyl acrylamide (DMAm) conjugates, with activity remaining approximately constant in 25 and 50% ethanol solvent systems. Interestingly, the activity of N,N-dimethylaminopropyl-acrylamide (DMAPA) conjugates increased gradually with increasing organic solvent content in the system. Contrary to other literature reports, our study showed significantly diminished activity for hydrophobic polymer-protein conjugates. Functional thermal stability assays also displayed a considerable enhancement of retained activity of Am, DMAm, and DMAPA conjugates compared to the native CalB enzyme. Thus, this study provides an insight into possible advances in lipase production, which can lead to new improved lipase bioconjugates with increased activity and stability.
