Target cells in radiation XXXX .

@entity1 @entity32 @entity82 @entity697 @entity55 @entity9757 @entity509 @entity401
Radiation @entity9757 is the reaction of the organ lung to radiation effects in various target cells. It starts as an exudative @entity32 , with the clinical picture of @entity401 6-12 weeks after irradiation, and proceeds to a productive chronic @entity32 lasting several months and terminating, as other chronic @entity32 do, in scar formation, @entity82 . Lung @entity82 is the common end point after lung damage from a wide range of damaging agents. The pathogenetic process leading to the signs and symptoms of radiation @entity9757 is an integrated response of the complex organization of lung tissue. Clinical and pathologic data in @entity1 do not support the hypothesis that the early inflammatory phase of radiation " @entity55 " and late "radiation @entity82 " are independent pathogenetic processes in the same way as @entity697 and subcutaneous @entity82 are separate pathologic entities. The target cell population that initiates the pathogenetic process in the lung is not known, and it has been suggested that no single identifiable target exists. The entire process is the result of complex functional alterations in endothelial cells, pneumocytes, macrophages, and other resident and transient cells. No evidence has been found for a role of stem cell sterilization, for impaired transit cell proliferation, or for @entity509 , which is the hallmark of other acute inflammatory normal tissue damage (i.e., in the mucosa). The radiobiologic concepts developed in cellular radiobiology are not adequate for the quantitative analysis of radiation @entity9757 . A new analytical framework based on structurally defined intercellular interaction by signaling molecules and their activation needs to be developed. This would not be only an abstract radiobiologic paradigm but would be the key to the development of potential therapeutic interventions in irradiated @entity1 .
