Nasal Brushing Sampling and Processing using Digital High Speed Ciliary Videomicroscopy - Adaptation for the COVID-19 Pandemic.

Primary Ciliary Dyskinesia (PCD) is a genetic motile ciliopathy, leading to significant otosinopulmonary disease. PCD diagnosis is often missed or delayed due to challenges with different diagnostic modalities. Ciliary videomicroscopy, using Digital High-Speed Videomicroscopy (DHSV), one of the diagnostic tools for PCD, is considered the optimal method to perform ciliary functional analysis (CFA), comprising of ciliary beat frequency (CBF) and beat pattern (CBP) analysis. However, DHSV lacks standardized, published operating procedure for processing and analyzing samples. It also uses living respiratory epithelium, a significant infection control issue during the COVID-19 pandemic. To continue providing a diagnostic service during this health crisis, the ciliary videomicroscopy protocol has been adapted to include adequate infection control measures. Here, we describe a revised protocol for sampling and laboratory processing of ciliated respiratory samples, highlighting adaptations made to comply with COVID-19 infection control measures. Representative results of CFA from nasal brushing samples obtained from 16 healthy subjects, processed and analyzed according to this protocol, are described. We also illustrate the importance of obtaining and processing optimal quality epithelial ciliated strips, as samples not meeting quality selection criteria do now allow for CFA, potentially decreasing the diagnostic reliability and the efficiency of this technique.

The antitumoral effect of endostatin and angiostatin is associated with a down-regulation of vascular endothelial growth factor expression in tumor cells.

Endostatin and angiostatin are known as tumor-derived angiogenesis inhibitors, but their mechanisms of action are not yet completely defined. We report here that endostatin and angiostatin, delivered by adenoviral vectors, reduced in vitro the neovessel formation in the mouse aortic ring assay by 85 and 40%, respectively. We also demonstrated in vivo that both endostatin and angiostatin inhibited local invasion and tumor vascularization of transplanted murine malignant keratinocytes, and reduced by 50 and 90% the development of highly vascularized murine mammary tumors. This inhibition of tumor growth was associated with a reduction of tumor vascularization. Expression analysis of vascular endothelial growth factor (VEGF) carried out in the mouse aortic ring model revealed a 3- to 10-fold down-regulation of VEGF mRNA expression in endostatin-treated rings. A similar down-regulation of VEGF expression at both mRNA and protein levels was also observed in the two in vivo cancer models after treatment with each angiogenesis inhibitor. This suggests that endostatin and angiostatin effects may be mediated, at least in part, by their ability to down-regulate VEGF expression within the tumor. This work provides evidence that endostatin and angiostatin act on tumor cells themselves.