Models of hemapoietic changes on the basis of systematically collected case histories of radiation accident victims as well as pathophysiologically evaluated patients after chronic radiation exposure / Erstellung von Haemopoesemodellen aufgrund datenbankmaessig detailliert erfasster Strahlenunfaelle - Systematisierung chronischer Strahlenexpositionen

The research project ''Models of Hematopoietic Changes on the Basis of Systematically Collected Case Histories of Radiation Accident Victims as well as Pathophysiologically Evaluated Patients after Chronic Radiation Exposure'' required the investigation of four major research problem areas. First of all, biomathematical models were improved or newly developed allowing the simulation of the radiation induced response patterns of granulocytes, lymphocytes and blood platelets. The compartment model approach allowed the establishment of the correlation of such blood cell changes to the extent of damage at the level of hemopoietic stem cells distributed throughout the skeleton. The utilization of neural-network techniques resulted in a ''synergetic'' model that enables the medical doctor - using blood cell changes within the first 5-6 days after exposure - to predict the further course of illness and to allow a rational approach to clinical management. Secondly, available information on the clinical consequences of radiation exposure on more than 800 accident victims enabled the team to develop an entirely new concept to recognize and treat such persons. For this approach the biomathematical models were used to identify ''response categories'' (rather than dosimetrically defined ''exposure categories'') with an organ specific grading code of the severity of radiation-induced damage. This grading allowed the semi-quantitative damage assessment of the hemopoiesis, the neurovascular system, the gastrointestinal as well as the cutaneous system. It forms the basis for a ''weighted'' prognosis and for the logistics of radiation accident medical management. In the third project domain, models were developed to understand pathophysiological mechanisms of biological consequences of chronic radiation in human beings (former USSR) as well as in a preclinical dog study (USA). From a large group of patients with the diagnosis of ''Chronic Radiation Sickness'' more than 80 were studied over a 40-year period. Their health impairments were systematically evaluated. The pathogenetic mechanisms responsible for tolerance or failure of hemopoiesis after chronic radiation exposure became clear from life-time radiation-exposed dogs. The rapidly renewing cell systems (such as blood cell production) can tolerate to a given limit chronic low-level radiation exposure resulting in ''excess cell loss'', which is compensated by increased cell production. Failure occurs when the stem cell pools are exhausted. The forth domain was devoted to the development of the structural principles of a computer-based assistance system to advise the medical doctor in the medical management of the radiation-induced health impairments. This system utilizes the biomathematical and biomedical radiation response models and allows the systematic assessment of any new radiation accident victims resulting then in a scientifically based strategy for treatment. (orig.) / Available from TIB Hannover: RO 3190(633) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische Informationsbibliothek / SIGLE / DE / Germany