Gehmlich K.,University College London |
Asimaki A.,Beth Israel Deaconess Medical Center |
Cahill T.J.,University College London |
Ehler E.,King's College London |
And 7 more authors.
Heart Rhythm | Year: 2010
Background: The diagnosis of arrhythmogenic right ventricular cardiomyopathy can be challenging. Disease-causing mutations in desmosomal genes have been identified. A novel diagnostic feature, loss of immunoreactivity for plakoglobin from the intercalated disks, recently was proposed. Objective: The purpose of this study was to identify two novel mutations in the intracellular cadherin segment of desmoglein-2 (G812S and C813R in exon 15). Co-segregation of the G812S mutation with disease expression was established in a large Caucasian family. Endomyocardial biopsies of two individuals showed reduced plakoglobin signal at the intercalated disk. Methods To understand the pathologic changes occurring in the diseased myocardium, functional studies on three mutations in exon 15 of desmoglein-2 (G812C, G812S, C813R) were performed. Results Localization studies failed to detect any differences in targeting or stability of the mutant proteins, suggesting that they act via a dominant negative mechanism. Binding assays were performed to probe for altered binding affinities toward other desmosomal proteins, such as plakoglobin and plakophilin-2. Although no differences were observed for the mutated proteins in comparison to wild-type desmoglein-2, binding to plakophilin-2 depended on the expression system (i.e., bacterial vs mammalian protein expression). In addition, abnormal migration of the C813R mutant protein was observed in gel electrophoresis. Conclusion Loss of plakoglobin immunoreactivity from the intercalated disks appears to be the endpoint of complex pathologic changes, and our functional data suggest that yet unknown posttranslational modifications of desmoglein-2 might be involved. © 2010 Heart Rhythm Society. All rights reserved.
Tarantini L.,S Martino Hospital |
Gori S.,S M Della Misericordia Hospital |
Faggiano P.,Spedali Civili |
Pulignano G.,Camillo Hospital |
And 6 more authors.
Annals of Oncology | Year: 2012
Background: Adjuvant Trastuzumab with chemotherapy is the gold standard for human epidermal growth factor receptor 2 (HER2)-positive early breast cancer (HER2+ EBC). Older patients have been largely under-represented in clinical trials, and few data on Trastuzumab cardiotoxicity have been reported in this subgroup. Patients and methods: Four hundred and ninety-nine consecutive HER2+ EBC patients were treated with adjuvant trastuzumab and chemotherapy (aTrastC) at 10 Italian institutions. We evaluated disease prevalence and patient characteristics in the patients older than 60 years of age (over-60), prevalence of aTrastC cardiotoxicity and risk factors. Results: There were 160 'over-60' patients (32%), in whom a higher prevalence of hypertension, diabetes, renal dysfunction, dyslipidemia and treatment with ACEi (40 versus 8%) and beta blockers (20 versus 8%) was found than in the younger patients (339 = 68%). Clinical heart failure occurred in 6% of the 'over-60' and in 2% of the younger patients. A reduction in left ventricular ejection fraction of >10 points was detected in 33% of the 'over-60' and in 23% of the younger patients (all P < 0.05). aTrastC was discontinued in 10% of the 'over-60' and in 4% of the younger patients (P = 0.003), restarted in 44% of the 'over-60' and in 58% of the younger women (P = ns). Conclusion: In clinical practice, 32% of HER2+ EBC patients treated with aTrastC are 'over-60'. These patients have an increased cardiovascular risk profile and develop aTrastC cardiotoxicity commonly. © The Author 2012. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved.