Individual tissues have significantly different resistance to ischemia–reperfusion damage. There is still no adequate treatment for the consequences of ischemia–reperfusion damage. By utilizing ischemic tolerance, it is possible to achieve a significant reduction in the extent of the cell damage due to ischemia–reperfusion injury. Since ischemia–reperfusion damage usually occurs unexpectedly, the use of preconditioning is extremely limited. In contrast, postconditioning has wider possibilities for use in practice. In both cases, the activation of ischemic tolerance can also be achieved by the application of sublethal stress on a remote organ. Despite very encouraging and successful results in animal experiments, the clinical results have been disappointing so far. To avoid the factors that prevent the activation of ischemic tolerance, the solution has been to use blood plasma containing tolerance effectors. This plasma is taken from healthy donors in which, after exposure to two sublethal stresses within 48 h, effectors of ischemic tolerance occur in the plasma. Application of this activated plasma to recipient animals after the end of lethal ischemia prevents cell death and significantly reduces the consequences of ischemia–reperfusion damage. Until there is a clear chemical identification of the end products of ischemic tolerance, the simplest way of enhancing ischemic tolerance will be the preparation of activated plasma from young healthy donors with the possibility of its immediate use in recipients during the initial treatment.

Mild traumatic brain injury (mTBI) is one of the most common trauma-related diagnoses treated in emergency departments, especially among the geriatric population. Higher age alone is often an indication for a computed tomography (CT) scan, even when, approximately 90% of these scans do not reveal intracranial injuries. Incorporation of new diagnostic parameters into indication schemes for CT scans could improve the efficiency and reduce unnecessary imaging. The primary outcome of this study was to evaluate the association of acute behavioral changes among elderly patients treated for mTBI with the prevalence of intracranial injuries diagnosed by CT scans. A retrospective cross-sectional study was conducted at Louis Pasteur University Hospital in Košice. All patients aged 65 and older who presented during the period of 12 months with suspected mTBI and underwent CT imaging were included in the study. Electronic health records were used as a data source. A total of 586 patients were included in the study. Acute behavioral changes were observed among 60 (10.2%) patients. Intracranial injury was diagnosed in 35 patients (6.0%). There was a statistically significant association between acute behavioral changes and the presence of intracranial injuries (p < 0.05), with those exhibiting behavioral changes having higher odds of injury (OR: 6.51; 3.01–13.7; p < 0.001). Elderly patients with mTBI who present with acute behavioral changes are more likely to have intracranial injuries detected by CT scans. Incorporating these symptoms into indication schemes for head CT scans may improve strategies aimed at more effective and judicious use of imaging. Clinical trial number: Not applicable, retrospectively registered.

Application of knowledge about ischemic tolerance to clinic requires the solid understanding of mechanism of creation of this phenomenon. This review summarizes research that has been carried out in many laboratories over a long period of time, but the main focus will be on own experimental research. The main emphasis is devoted to the possibility of preparing full tolerance in the donor's body and its transfer to the patient in the form of activated blood plasma. Such plasma could be administered as soon as the patient is transported to the hospital and would take effect immediately after administration to the patient's bloodstream. One chapter is also devoted to anticonditioning, i.e. the possibility of preventing the activation of tolerance. Anticonditioning could be used to treat oncologic patients. We expect that this method could increase effectiveness of cancer treatment. Cross-tolerance with a wide range of diverse stressors gives us the courage to assume that activated plasma can significantly help with a wide range of pathological events.

Ischemic tolerance is a robust internal defense mechanism of all living organisms. The effectiveness of this mechanism has been repeatedly demonstrated in experiments, but a comprehensive review of the clinical applicability of this phenomenon in practice has not yet been published. The results in clinical practice sound ambiguous and unconvincing in comparison with the results of experimental studies. Also, in many localities, the effect of ischemic tolerance was not clinically proven. For the reasons mentioned, the authors analyze the possible causes of the mentioned discrepancies and provide a comprehensive insight into the possible relevant clinical use of this phenomenon in practice for different groups of patients.