In an emergency, EMTs are typically dispatched to the scene by a 911 operator and often work with police and fire department personnel. Once they arrive, they determine the nature and extent of a patients condition while trying to ascertain whether the patient has preexisting medical problems.
Platelet endothelial cell adhesion molecule (PECAM-1) also known as cluster of differentiation 31 (CD31) is a protein that in humans is encoded by the PECAM1 gene found on chromosome 17.PECAM-1 plays a key role in removing aged neutrophils from the body.D31 is also expressed in certain tumors, including epithelioid hemangioendothelioma, epithelioid sarcoma-like hemangioendothelioma, other vascular tumors, histiocytic malignancies, and plasmacytomas.
(A) CD31 expression in lymph nodes showing positive marginal (subcapsular) sinuses, high endothelial venules (HEV), and capillaries. In contrast, marginal sinuses are negative for CD34 (B) and vWF (C). (D) Most of the cells present in lymph nodes including EC from capillaries and HEV are stained for Fli-1.D31, a member of the immunoglobulin superfamily, is a 130-kDa transmembrane glycoprotein also designated as PECAM-1 (platelet endothelial cell adhesion molecule 1). It is present on the surface of platelets, monocytes, macrophages, and neutrophils and is a constituent of the endothelial intercellular junction.