Publications

Several features of cardiovascular devices raise considerations for clinical trial conduct. Prospective, randomized, controlled trials remain the highest quality evidence for safety and effectiveness assessments, but, for instance, blinding may be challenging. In order to avoid bias and not confound data interpretation, the use of objective endpoints and blinding patients, study staff, core labs, and clinical endpoint committees to treatment assignment are helpful approaches. Anticipation of potential bias should be considered and planned for prospectively in a cardiovascular device trial. Prospective, single-arm studies (often referred to as registry studies) can provide additional data in some cases. They are subject to selection bias even when carefully designed; thus, they are generally not acceptable as the sole basis for pre-market approval of high risk cardiovascular devices. However, they complement the evidence base and fill the gaps unanswered by randomized trials. Registry studies present device safety and effectiveness in day-to-day clinical practice settings and detect rare adverse events in the post-market period. No single research design will be appropriate for every cardiovascular device or target patient population. The type of trial, appropriate control group, and optimal length of follow-up will depend on the specific device, its potential clinical benefits, the target patient population and the existence (or lack) of effective therapies, and its anticipated risks. Continued efforts on the part of investigators, the device industry, and government regulators are needed to reach the optimal approach for evaluating the safety and performance of innovative devices for the treatment of cardiovascular disease.

Airway epithelial cells are the primary cell type involved in respiratory viral infection. Upon infection, airway epithelium plays a critical role in host defense against viral infection by contributing to innate and adaptive immune responses. Influenza A virus, rhinovirus, and respiratory syncytial virus (RSV) represent a broad range of human viral pathogens that cause viral pneumonia and induce exacerbations of asthma and chronic obstructive pulmonary disease. These respiratory viruses induce airway epithelial production of IL-8, which involves epidermal growth factor receptor (EGFR) activation. EGFR activation involves an integrated signaling pathway that includes NADPH oxidase activation of metalloproteinase, and EGFR proligand release that activates EGFR. Because respiratory viruses have been shown to activate EGFR via this signaling pathway in airway epithelium, we investigated the effect of virus-induced EGFR activation on airway epithelial antiviral responses. CXCL10, a chemokine produced by airway epithelial cells in response to respiratory viral infection, contributes to the recruitment of lymphocytes to target and kill virus-infected cells. While respiratory viruses activate EGFR, the interaction between CXCL10 and EGFR signaling pathways is unclear, and the potential for EGFR signaling to suppress CXCL10 has not been explored. Here, we report that respiratory virus-induced EGFR activation suppresses CXCL10 production. We found that influenza virus-, rhinovirus-, and RSV-induced EGFR activation suppressed IFN regulatory factor (IRF) 1-dependent CXCL10 production. In addition, inhibition of EGFR during viral infection augmented IRF1 and CXCL10. These findings describe a novel mechanism that viruses use to suppress endogenous antiviral defenses, and provide potential targets for future therapies.

BACKGROUND

Understanding normal volume asymmetry is essential for accurate assessment of limb volume changes following breast cancer (BC) treatment in which lymphatic function is disrupted. The purposes of this study were to evaluate for differences in dominant and nondominant limb volumes and to evaluate for interactions between the effects of dominance and side of cancer on limb volume.

METHODS AND RESULTS

This study evaluated preoperative limb volumes of 397 women enrolled in a prospective, longitudinal study of neuropathic pain and lymphedema. Volume was calculated from circumference. Limb resistance was measured with bioimpedance. Women were dichotomized into two groups: those whose cancer was on their dominant side and those whose cancer was on their nondominant side. Analyses of variance were used to evaluate for differences. In 47%, BC occurred on the side of the dominant limb. Except for the 30 to 40 centimeter (cm) limb volume segment, a main effect of dominance was found for all measures. The volume of the dominant limb was significantly greater than that of the nondominant limb. No main effects were found for side of cancer. A statistically significant interaction was found only at the 0 to 10 cm limb volume segment.

CONCLUSIONS

Prior to BC treatment, the dominant limb demonstrated lower bioimpedance resistance (-2.09%) and greater total limb volume (1.12%) than the nondominant limb. Segmental volume differences were greatest at the proximal forearm segment (2.31%) and least at the proximal arm segment (0.21%). This study provides evidence that preoperative volume assessment is important due to normal variability associated with limb dominance.