Objective: Cerebral amyloid angiopathy (CAA) is a common age-related small vessel disease (SVD). Patients without intracerebral hemorrhage (ICH) typically present with transient focal neurologic episodes (TFNEs) or cognitive symptoms. We sought to determine if SVD lesion burden differed between patients with CAA first presenting with TFNEs vs cognitive symptoms.Methods: A total of 647 patients presenting either to a stroke department (n 5 205) or an outpatient memory clinic (n 5 442) were screened for eligibility. Patients meeting modified Boston criteria for probable CAA were included and markers of SVD were quantified, including cerebral microbleeds (CMBs), perivascular spaces, cortical superficial siderosis (cSS), and white matter hyperintensities (WMHs). Patients were classified according to presentation symptoms (TFNEs vs cognitive). Total CAA-SVD burden was assessed using a validated summary score. Individual neuroimaging markers and total SVD burden were compared between groups using univariable and multivariable models.Results: There were 261 patients with probable CAA included. After adjustment for confounders, patients first seen for TFNEs (n 5 97) demonstrated a higher prevalence of cSS (p , 0.0001), higher WMH volumes (p 5 0.03), and a trend toward higher CMB counts (p 5 0.09). The total SVD summary score was higher in patients seen for TFNEs (adjusted odds ratio per additional score point 1.46, 95% confidence interval 1.16-1.84, p 5 0.013). Conclusions:Patients with probable CAA without ICH first evaluated for TFNEs bear a higher burden of structural MRI SVD-related damage compared to those first seen for cognitive symptoms. This study sheds light on neuroimaging profile differences across clinical phenotypes of patients with CAA without ICH. Neurology ® 2017;88:878-884 GLOSSARY BG 5 basal ganglia; CAA 5 cerebral amyloid angiopathy; CI 5 confidence interval; CMB 5 cerebral microbleed; CSO 5 centrum semiovale; cSS 5 cortical superficial siderosis; FLAIR 5 fluid-attenuated inversion recovery; ICH 5 intracerebral hemorrhage; IQR 5 interquartile range; OR 5 odds ratio; PVS 5 perivascular spaces; SVD 5 small vessel disease; TE 5 echo time; TFNE 5 transient focal neurologic episode; WMH 5 white matter hyperintensity.Sporadic cerebral amyloid angiopathy (CAA) is characterized by progressive deposition of b-amyloid in the walls of cortical and leptomeningeal small arteries, resulting in vessel dysfunction and brain parenchymal injury. CAA is common in older individuals and, when severe, can lead to devastating consequences including intracerebral hemorrhage (ICH) and dementia. 1,2While definite diagnosis relies on pathology, clinical and neuroimaging criteria (the Boston criteria) can reliably identify CAA in older patients with lobar hemorrhage.3,4 More recently, an updated version of these criteria has demonstrated that the presence of $2 lobar cerebral microbleeds (CMBs) in patients without large hemorrhage is specific for moderate to severe CAA pathology presence in older individuals seen in a h...
Doxorubicin is a widely used cancer therapeutic, but its effectiveness is limited by cardiotoxic side effects. Evidence suggests cardiotoxicity is due not to doxorubicin, but rather its metabolite, doxorubicinol. Identification of the enzymes responsible for doxorubicinol formation is important in developing strategies to prevent cardiotoxicity. In this study, the contributions of three murine candidate enzymes to doxorubicinol formation were evaluated: carbonyl reductase (Cbr) 1, Cbr3, and thioredoxin reductase 1 (Tr1). Analyses with purified proteins revealed that all three enzymes catalyzed doxorubicindependent NADPH oxidation, but only Cbr1 and Cbr3 catalyzed doxorubicinol formation. Doxorubicin-dependent NADPH oxidation by Tr1 was likely due to redox cycling. Subcellular fractionation results showed that doxorubicin-dependent redox cycling activity was primarily microsomal, whereas doxorubicinol-forming activity was exclusively cytosolic, as were all three enzymes. An immunoclearing approach was used to assess the contributions of the three enzymes to doxorubicinol formation in the complex milieu of the cytosol. Immunoclearing Cbr1 eliminated 25% of the total doxorubicinol-forming activity in cytosol, but immunoclearing Cbr3 had no effect, even in Tr1 null livers that overexpressed Cbr3.The immunoclearing results constituted strong evidence that Cbr1 contributed to doxorubicinol formation in mouse liver but that enzymes other than Cbr1 also played a role, a conclusion supported by ammonium sulfate fractionation results, which showed that doxorubicinol-forming activity was found in fractions that contained little Cbr1. In conclusion, the results show that Cbr1 accounts for 25% of the doxorubicinol-forming activity in mouse liver cytosol but that the majority of the doxorubicinolforming activity remains unidentified. SIGNIFICANCE STATEMENTEarlier studies suggested carbonyl reductase (Cbr) 1 plays a dominant role in converting chemotherapeutic doxorubicin to cardiotoxic doxorubicinol, but a new immunoclearing approach described herein shows that Cbr1 accounts for only 25% of the doxorubicinol-forming activity in mouse liver cytosol, that two other candidate enzymes-Cbr3 and thioredoxin reductase 1-play no role, and that the majority of the activity remains unidentified. Thus, targeting Cbr1 is necessary but not sufficient to eliminate doxorubicinol-associated cardiotoxicity; identification of the additional doxorubicinol-forming activity is an important next challenge.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.