Modifiers of membranes cause local defects on the cell surface. Measurement of the rigidity at the sites of local defects can provide further information about the structure of defects and mechanical properties of altered membranes.The purpose of the study: a step-by-step study of the process of a nonlinear deformation of red blood cells membranes under the effect of modifiers of different physico-chemical nature.Materials and methods. The membrane deformation of a viscoelastic composite erythrocyte construction inside a cell was studied by the atomic force spectroscopy. Nonlinear deformations formed under the effect of hemin, Zn2+ ions, and verapamil were studied.Results. The process of elastic deformation of the membrane with the indentation of a probe at the sites of local defects caused by modifiers was demonstrated. The probe was inserted during the same step of the piezo scanner z displacement; the probe indentation occured at the different discrete values of h, which are the functions of the membrane structure. At the sites of domains, under the effect of the hemin, tension areas and plasticity areas appeared. A mathematical model of probe indentation at the site of membrane defects is presented.Conclusion. The molecular mechanisms of various types of nonlinear deformations occurring under the effect of toxins are discussed. The results of the study may be of interest both for fundamental researchers of the blood cell properties and for practical reanimatology and rehabilitology.
Concurrent cardiac failure is an universally accepted risk factor in surgical patients undergoiing cardiac or non-cardiac surgery.The aim of this study was to search for and identify factors or markers, which would permit to predict early (up to 30 days) or late (up to 1 year) adverse outcomes in patients with acute heart failure (AHF) in the vascular surgery.Materials and Methods. A randomized, multicenter, prospective — retrospective study was performed. 89 patients who had signed the Informed Consent Form were randomized. Throughout the four stages of the study, the cardiac index (CI) and the left ventricle ejection fraction (LVEF) values were recorded. At the same stages, blood was sampled to be tested for the NT-proBNP level. The TnT level was tested only at the 3rd stage of the study. The required stay in the intensive care unit (ICU) and in the in-patient hospital, the incidence of infarctions and strokes during the early postoperative period (up to 30 days), the 30&day and one-year mortality rates were recorded.Results. Different AHF prevention methods were used in patients included into this study in the postoperative period. Predictors of adverse events were studied in a combined population. The incidence of acute myocardial infarction (AMI) was 12% and that of stroke was 2%. The in-hospital mortality rate in the combined group was 2%; the one-year mortality was 10%. Patients stayed in the intensive care unit for 3 (2—4) days; the hospital stay was 11 (10—13) days; the composite adverse outcome of the surgical treatment was registered in 15% of patients. As a result, the Troponin T level was the only significant prognostic factor during the first 24 hours of the postoperative period. A study of the prognostic significance of different parameters in relation to their effect on the one-year mortality rate demonstrated a similar result. Vasoactive Inotropes Score (VIS) turned out to be the most significant criterion for prediction of possible treatment duration.Conclusion. The study results confirmed the predictive value of early determination of TnT levels after reparative vascular surgeries in patients with decreased left ventricular ejection fraction. The diagnostic value of the VIS calculation needs further confirmation.
Objective: to evaluate the effects of the immunostimulants panavir and derinate on a postresuscitation process in animals of different sexes.Material and methods. The investigation was made on 200—250-g albino rats of both sexes in winter. Circulation was stopped by intrathoracic ligation of the cardiac vascular bundle in ether<anesthetized rats for 10 min. Functional recovery of the central nervous system and changes in sex steroid hormones were assessed in the postresuscitation period. The investigation used two immunoactive drugs: panavir 0.02 mg/kg and derinate 150 μg/kg. Either agent was intramuscularly injected twice: at 3 0 minutes after resuscitation and on the following day.Results. The injected drugs were ascertained to have a positive effect on functional recovery of the brain. Their use was shown to modify the sex steroid hormone profiles in both males and females in the early postresuscitation period.Conclusion. The findings suggest that the immunoactive agents are able to affect the nervous and endocrine systems in critical conditions.