Fibronectins. Practitioners, academicians, and physicians-intraining should take notice of these proteins. The term "fibronectin" comes from Latin roots: fibro- from fibra, meaning fiber, -nectin from nexus, which means interconnection. A fibronectin is a fibrous, linking protein. Whereas plasma fibronectin is a circulating α2-glycoprotein that functions as an opsonin, cell-surface fibronectin mediates cellular adhesive interactions. Plasma fibronectin is a soluble version of cell-surface fibronectin. Both seem to be products of the same gene, although this has not been proved.
The potential importance of fibronectins to clinicians is suggested by the following summary of fibronectin function. Reticuloendothelial system (RES)—mediated host-defense mechanisms are impaired in surgical and trauma patients and also in severely burned patients. Depression of RES function is also seen in patients with bacterial infection, neoplasia, and diseases of altered immunity. Such defects in host defense may result in sepsis and multiorgan failure.
It is postulated that such failures