Background and purpose:Stroke-associated pneumonia (SAP) is associated with poor functional outcome in patients with acute ischemic stroke (AIS). The objective of this study was to identify predictors of SAP in patients underwent intra-arterial treatment (IAT).Methods:Consecutive patients with AIS within 6 h from the symptom onset underwent IAT were enrolled. Independent predictors of in-hospital SAP after AIS were obtained using multivariable logistic regression. Kaplan–Meier survival curves were calculated and compared by the log-rank test.Results:Of 165 patients with AIS in the study period, 102 (61.8%) underwent IAT. Twenty-two (21.6%; 95% confidence interval [CI], 14.7–29.4) experienced SAP. Patients with SAP were older (69.2 vs 62.9 years, respectively; P = 0.011), more severely affected (National Institutes of Health Stroke Scale score, 18 vs 9, respectively; P = 0.004), more likely to underwent symptom of dysphagia (86.4% vs 15%, respectively; P < 0.001), lower Glasgow Coma Scale score (9 vs 13, respectively; P < 0.001), and longer operation time (149.5 vs 123, respectively; P < 0.001) than those without SAP. Only symptom of dysphagia (adjust odds ratio [OR], 12.051; 95% CI, 3.457–50.610; P < 0.001) and total time of operation (adjust OR, 1.040; 95% CI, 1.009–1.071; P < 0.001) were identified as independent predictors of SAP. Patients with SAP had stable or improved deficits after AIS with IAT (P < 0.001).Conclusions:Besides dysphagia, total time of operation is a risk factor of SAP in patients with AIS with IAT.

B12-independent glycerol dehydratase (GD) is a glycyl radical enzyme in the biotransformation of glycerol to 1,3-propanediol. GD requires the activating enzyme GD-AE to initiate the radical reaction. GD-AE belongs to...

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Radical S-adenosylmethionine (SAM) enzymes are a family of proteins with hundreds of thousands of members that all contain an essential [4Fe-4S] cluster. The [4Fe-4S] cluster needs to be reduced to cleave SAM and generate a 5′-deoxyadenosyl or 3-amino-3-carboxypropyl radical. Due to the low reduction potential of the [4Fe-4S] cluster, dithionite has been widely used in studies on the activity of radical SAM enzymes in vitro. Inspired by the efficient photoreduction of the [4Fe-4S] cluster in natural photosystem I, we applied the 27 kDa photosensitizer protein PSP2, which we reported previously, to reduce the [4Fe-4S] cluster of radical SAM enzymes. Herein, we demonstrate that light-activated PSP2 generates a PSP2 radical, which is capable of reducing the catalytic [4Fe-4S] cluster of the radical SAM enzyme BtrN. PSP2-reduced BtrN cleaves SAM to generate 5′-deoxyadenosine and converts the substrate 2-deoxy-scyllo-inosamine to 3-amino-2,3-dideoxy-scyllo-inosose. Remarkably, our study shows that PSP2 can reduce the auxiliary [4Fe-4S] cluster of BtrN that has the lowest reduction potential among the known radical SAM enzymes and cannot be reduced by dithionite. The reduction of this auxiliary cluster experimentally proves its function in product formation. In addition, we show that PSP2 can reduce the [4Fe-4S] cluster of Dph2, a noncanonical radical SAM enzyme involved in diphthamide biosynthesis, and help the modification of the substrate protein elongation factor 2. Therefore, PSP2 is a powerful photoreductant for radical SAM enzymes and a useful tool for studying clusters with low reduction potential.