SARATOV MEDICAL JOURNAL

Objective: to evaluate the activity of oxidative stress in rats with stepwise incomplete cerebral ischemia (SICI). Material and methods. Experiments were performed on 24 male outbred rats weighing 260±20 g, allocated into 3 subgroups (6 animals in each) based on time of ligation of both common carotid arteries (CCA). The control group comprised of sham-operated rats of the same sex and similar weights (n=6). To identify the pro-oxidant–antioxidant state of the brain based on its homogenates, the activity of lipid peroxidation processes, the content of thiobarbituric acid reactive substances (TBARS), the concentration of reduced glutathione (GSH), total thiol groups (TSH), and the activity of glutathione peroxidase were determined.

Results. SICI with ligation interval of both CCAs of 1 day and 3 days led to a significant decrease in the total SH groups of proteins and glutathione by 30% (p=0.038) and 46% (p=0.044), respectively, TBARS concentration by 29% (p=0.038) and 31% (p=0.043), respectively. SICI with the maximum interval between CCA ligations was manifested by less pronounced changes in the pro-oxidant–antioxidant state of the brain.

Conclusion. In SICI with ligation of both CCAs 7 days apart, at which histological changes were the least pronounced, changes in the pro-oxidant–antioxidant balance were insignificant. The most pronounced disorders of the pro-oxidant–antioxidant balance in the brain were observed in the subgroup with the minimum interval between CCA ligations, which implied the highest activity of oxidative stress.

Objective: To assess the sensitivity, specificity and accuracy of a digital algorithm based on convolutional neural networks used for restoring the lost surface of the skull bones.

Materials and methods. The neural network was trained over 6,000 epochs on 78,000 variants of skull models with artificially generated skull injuries. The key parameters of the algorithm were assessed on 222 series of multislice computed tomography (MSCT) of patients with defects of the skull bones, presented in DICOM format.

Results. For the group as a whole, the sensitivity, specificity, and accuracy rates were 95.3%, 85.5%, and 79.4%, respectively. Multiple experiments were conducted with a step-by-step elimination of 3D models in order to find the underlying cause of unsatisfactory outcomes of the skull lost surface restoration. Incorrect identification of the defect zone most often occurred in the area of the facial skeleton. After excluding series with the presence of artifacts, the mean increase in metrics was 2.6%. Conclusion. The accuracy of identifying the reference points (specificity) on a 3D model of the skull by the algorithm had the greatest impact on the ultimate accuracy of repairing the lost surface. The maximum accuracy of the algorithm allowing the use of the resulting surfaces without additional processing in a 3D modeling environment was achieved in series without the presence of artifacts in computed tomography (83.5%), as well as with defects that did not extend to the base of the skull (79.5%).

Objective: to determine the prognostic value of skin autofluorescence (SAF) as a factor of cardiovascular complications and mortality.

Materials and Methods. Our prospective study included 122 patients with peripheral arterial disease (PAD): atherosclerotic stenosis of the brachiocephalic trunk was detected in 95 patient (77.9%), while chronic arterial insufficiency (CAI) of the lower limbs was found in 47 study participants (38.5%). SAF was measured by an original device developed by the authors. Clinical, anthropometric and biochemicalparameters, along with instrumental parameters of the heart and blood vessels, were studied via ultrasound examination. The prospective part of the study (follow-up) was carried out for up to 1,043 (on average, 736) days. Results.The SAF parameter correlated directly and significantly with scores on the scale of clinical prognostic signs, CAIof the lower limbs, and history of surgeries on the leg arteries. In the course of the follow-up period, there were seven deaths and at least one hospitalization for cardiovascular reasons in 42 patients. The most common were hospitalizations due to conservative treatment of CAI, the need for coronary artery bypass grafting, and coronary stenting. Using the logistic regression method, we determined that the incidence of hospitalization or mortality was associated with SAF values, plasma glucosecontent, and the presence of chronic heart failure above functional class 1. The sensitivity and specificity of the model were 71% and 68%, respectively.

Conclusion.The SAF parameter can be used as an integral independent predictor in patients with multifocal atherosclerosis.