Rabbit Anti-Human EGFR (Phospho-Tyr1110) polyclonal antibody

Background Low-flow low-gradient (LF-LG) aortic stenosis (AS) is associated with high mortality, even after transcatheter aortic valve replacement (TAVR). Further knowledge of risk indicators is needed and a clinical risk score would be desirable for optimizing patient selection and therapeutic strategy. Methods The study cohort comprised of 219 consecutive LF-LG AS patients undergoing TAVR from 2008 to 2018 in two high-volume German centers. Predictive factors for one-year all-cause mortality were defined according to a Cox proportional hazard model. Results At one-year follow-up after TAVR, 28% of patients had died. A multivariate model revealed six independent predictors of one-year mortality: history of myocardial infarction (HR 2.05, 95%CI 1.13-3.72), eGFR < 30 ml/min/1.73m(2)(HR 2.75, 95%CI 1.48-5.11), tricuspid regurgitation moderate or more (HR 2.06, 95%CI 1.14-3.72), stroke volume index < 25 mL/m(2)(HR 2.03, 95%CI 1.14-3.62), self-expandable device (HR 2.72, 95%CI 1.17-6.27), and non-transfemoral approach (HR 3.42, 95%CI 1.28-9.14). The Rhineland Risk Score (RRS) consisting of these variables (c statistic 0.75, 95%CI 0.68-0.82,p < 0.001) was superior to the EuroSCORE II (c statistic 0.63) and STS-PROM score (c statistic 0.69) at predicting one-year mortality. Patients with a RRS >= 8 had a prohibitive risk of one-year mortality of 67.6% (95%CI 52.0-82.4%). Conclusion In patients with LF-LG AS, history of myocardial infarction, renal dysfunction, tricuspid regurgitation, a low stroke volume index, self-expandable device, and non-femoral approach were associated with increased 1-year mortality after TAVR. The RRS might serve as a helpful tool for risk prediction and patient selection for TAVR in patients with LF-LG AS.

Phase three clinical trial evidence suggests that colorectal cancers with the KRAS G13D mutation may benefit from EGFR inhibitors, like cetuximab, in contrast to the other most common KRAS mutations. A mechanism to explain why this mutation behaves differently from other KRAS mutations had long been lacking. Two recent studies have reproduced KRAS G13D specific sensitivity to cetuximab in cellular models, and both have implicated the tumor suppressor NF1 as a critical variable in determining sensitivity and resistance. One study proposes a mechanism that focuses on the inhibition of active, GTP-bound wild-type RAS, which is proposed to occur to a greater extent in KRAS G13D tumors due to the inability of KRAS G13D to bind NF1 well. The other study suggests NF1 can convert GTP-bound KRAS G13D to inactive, GDP-bound KRAS G13D. Here, we report an inability to reproduce cellular and biophysical studies that suggested NF1 has strong GTPase activity on KRAS G13D. We also report additional data that further suggests only WT RAS-GTP levels are reduced with EGFR inhibition and that KRAS G13D is impaired in binding to NF1. These new experiments further support a mechanism in which cetuximab inhibits wild-type (HRAS and NRAS) signals in KRAS G13D colorectal cancers.