Vital reactions - An updated overview.

The question whether an injury was sustained during life or not is one of the most important subjects in forensic medicine. Therefore, vital reactions have been a main research topic in forensic medicine for a long period and many renowned forensic pathologists have devoted important papers to this field. The research area ranges from macroscopically visible organ reactions, over tissue alterations (enzyme histochemistry, later on immunohistochemistry with a wide range of enzymes and other analytes, molecular pathology) to biochemical responses to injury. Especially in the field of immunohistochemistry and molecular pathology much progress has been achieved in the last years (e.g. heat-shock-proteins or positive aquaporine3-staining in mechanical skin trauma). Furthermore, 20 years after its implementation postmortem imaging also contributes to the detection and visualization of vital signs. The aim of the present review is to provide an update on forensically relevant vital signs/vital reactions. Systemic vital reactions especially of the circulatory and respiratory system as well as local vital reactions will be addressed. Vital reactions of different organ systems will be discussed in detail regarding pathogenesis and possible postmortem evolution. Current research on immunohistochemically detectable vital reactions (heat-shock-protein expression, aquaporine3-staining in mechanical trauma of the skin) will be addressed as well as biochemical vital reactions (agonochemical stress reaction, myoglobine in electrocution death, hypoxanthine as marker of hypoxia).