[EXPERIMENTAL STUDY OF THE ULTIMATE STRENGTH OF SAMPLES OF MATERIAL BASED ON POLYLACTIDE AND TRICALCIUM PHOSPHATE, PRODUCED BY 3D PRINTING WITH DIFFERENT POROSITIES, DEPENDING ON THE TIME OF HYDRATION]

The advantage of polylactide-based implants is their rapid and complete biodegradation, followed by replacement of the defect with bone tissue. The disadvantage of materials with a high biodegradation rate is their low support ability. The admixture of ceramic materials increases the strength of the implants and reduces the rate of biodegradation. 3D printing technology allows you to reduce the negative factors of ceramic impurities through the manufacture of implants of various porosities. Target. Determine the ultimate strength of a composite material based on PLA and TCP, manufactured by 3D printing with different porosity options, depending on the duration of hydration. Were made 9 samples of material with a size of 10x10x10 mm with different porosity 40%, 30%, 20%. Samples of the material were hydrated in saline. Strength tests were carried out on days 2, 10, and 20 after hydration, 3 samples of material of each porosity. All samples were tested for compression. The carried out comparative analysis indicates that the tested samples are statistically significant (at the level of p <0.05) differ from each other depending on the value of porosity at all periods of hydration. Although the average values of the ultimate strength of samples of the same porosity tend to decrease depending on the period of their hydration, these changes do not acquire statistical significance even between the extreme periods of observation. This is confirmed by the values of the indicator of the statistical significance of the differences p equal to 0.07; 0.759 and 0.124 for specimens with porosity of 20%, 30% and 40%, respectively. The tensile strength of samples of material based on polylactide and tricalcium phosphate, made using 3D printing, directly depends on their porosity, the smaller the pore volume, the stronger the samples. The hydration of the samples in saline solution for 20 days does not entail statistically significant changes in their strength regardless of the pore volume, although the average values of the ultimate strength for all tested samples tend to decrease.

MANAGEMENT OF EMOTIONAL DISORDERS IN ELDERLY PATIENTS UNDERGOING SURGICAL TREATMENT OF PROXIMAL FEMORAL FRACTURES

The goal of our research was to study the to identify key aspects of the management of emotional disorders in the practice of operative treatment of proximal femoral fractures in elderly patients. The study was conducted with 24 patients who needed surgical treatment of proximal femoral fracture and were at risk for the development of psycho-emotional disorders due to the presence of emotional disorders of an anxiety-depressive nature were examined. The presence of such disorders was recorded at the time of admission, before and after surgical treatment using specialized psychodiagnostic techniques. Mini Mental State Examination, modified Hachinski ischemic scale, Frontal assessment battery, Spielberg-Khanin Scale of Reactive and Trait Anxiety, The Zung Self-Rating Depression Scale were used. Results of the clinical study of the Most patients at risk had a high level of reactive anxiety - 14 (58.33%) patients (equally in subgroups I and II - 7 (29.17%) patients in each) compared with moderate levels (10 (41.67%) patients) - equally I and II subgroups (5 (20.83%) patients in each). In the subgroups I and II with moderate and high levels of reactive anxiety, a predominance of female patients was noted: subgroup I - female patients with a moderate level - 3 (12.50%), and with a high level -5 (20.83%); subgroup II - 3 (12.50%) and 4 (16.67%) female patients respectively. As a result of determining the key aspects of the management of emotional disorders in the practice of operative treatment of proximal femoral fractures in elderly patients:the presence of moderate (41.67%) and high (58.33%) levels of reactive and trait anxiety in elderly patients with proximal femoral fractures and emotional disorders is noted. The presence of a depressive state of varying severity was recorded: a subdepressive state (75.00%) and mild depression (25.00%). The general levels of reactive and trait anxiety and depressive disorders showed the presence of limit levels between moderate, high (reactive and trait anxiety) and mild depression and sub-depressive state (depressive disorders): reactive anxiety (42.52±0.05), trait anxiety (42.23±0.07) and depressive disorders (51.41±0.07). It is proved that the treatment of emotional disturbances of the anxiety-depressive spectrum lead to a significant levelling in existing psychological changes.The deterioration of the existing emotional disorders of the anxiety-depressive spectrum among patients at risk in the absence of drug treatment has been established.

Impact of a novel phosphoinositol-3 kinase inhibitor in preventing mitochondrial DNA damage and damage-associated molecular pattern accumulation: Results from the Biochronicity Project

BACKGROUND

Despite improvements in the management of severely injured patients, development of multiple organ dysfunction syndrome (MODS) remains a morbid complication of traumatic shock. One of the key attributes of MODS is a profound bioenergetics crisis, for which the mediators and mechanisms are poorly understood. We hypothesized that metabolic uncoupling using an experimental phosphoinositol-3 kinase (PI3-K) inhibitor, LY294002 (LY), may prevent mitochondrial abnormalities that lead to the generation of mitochondrial DNA (mtDNA) damage and the release of mtDNA damage-associated molecular patterns (DAMPs).

METHODS

Sixteen swine were studied using LY, a nonselective PI3-K inhibitor. Animals were assigned to trauma only (TO, n = 3), LY drug only (LYO, n = 3), and experimental (n = 10), trauma + drug (LY + T) groups. Both trauma groups underwent laparotomy, 35% hemorrhage, severe ischemia-reperfusion injury, and protocolized resuscitation. A battery of hemodynamic, laboratory, histological, and bioenergetics parameters were monitored. Mitochondrial DNA damage was determined in lung, liver, and kidney using Southern blot analyses, whereas plasma mtDNA DAMP analysis used polymerase chain reaction amplification of a 200-bp sequence of the mtDNA D-loop region.

RESULTS

Relative to control animals, H + I/R (hemorrhage and ischemia/reperfusion) produced severe, time-dependent decrements in hepatic, renal, cardiovascular, and pulmonary function accompanied by severe acidosis and lactate accumulation indicative of bioenergetics insufficiency. The H-I/R animals displayed prominent oxidative mtDNA damage in all organs studied, with the most prominent damage in the liver. Mitochondrial DNA damage was accompanied by accumulation of mtDNA DAMPs in plasma. Pretreatment of H + I/R animals with LY resulted in profound metabolic suppression, with approximately 50% decreases in O2 consumption and CO2 production. In addition, it prevented organ and bioenergetics dysfunction and was associated with a significant decrease in plasma mtDNA DAMPs to the levels of control animals.

CONCLUSIONS

These findings show that H + I/R injury in anesthetized swine is accompanied by MODS and by significant mitochondrial bioenergetics dysfunction, including oxidative mtDNA damage and accumulation in plasma of mtDNA DAMPs. Suppression of these changes with the PI3-K inhibitor LY indicates that pharmacologically induced metabolic uncoupling may comprise a new pharmacologic strategy to prevent mtDNA damage and DAMP release and prevent or treat trauma-related MODS.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Selective elimination of mutant mitochondrial genomes as therapeutic strategy for the treatment of NARP and MILS syndromes

Mitochondrial diseases are not uncommon, and may result from mutations in both nuclear and mitochondrial DNA (mtDNA). At present, only palliative therapies are available for these disorders, and interest in the development of efficient treatment protocols is high. Here, we demonstrate that in cells heteroplasmic for the T8993G mutation, which is a cause for the NARP and MILS syndromes, infection with an adenovirus, which encodes the mitochondrially targeted R.XmaI restriction endonuclease, leads to selective destruction of mutant mtDNA. This destruction proceeds in a time- and dose-dependent manner and results in cells with significantly increased rates of oxygen consumption and ATP production. The delivery of R.XmaI to mitochondria is accompanied by improvement in the ability to utilize galactose as the sole carbon source, which is a surrogate indicator of the proficiency of oxidative phosphorylation. Concurrently, the rate of lactic acid production by these cells, which is a marker of mitochondrial dysfunction, decreases. We further demonstrate that levels of phosphorylated P53 and gammaH2ax proteins, markers of nuclear DNA damage, do not change in response to infection with recombinant adenovirus indicating the absence of nuclear DNA damage and the relative safety of the technique. Finally, some advantages and limitations of the proposed approach are discussed.

Effect of ischemia, calcium depletion and repletion, acidosis and hypoxia on cellular taurine content

Occlusion of the left main coronary artery led to a time-dependent release of taurine from the heart. Upon reperfusion, there was a second phase of taurine release, which exceeded the amount of taurine that exited the heart during the 45 min ischemic insult. To obtain information on the mechanism underlying the release of taurine, three variables were examined, acidosis, hypoxia and calcium overload. It was found that large amounts of taurine also leave the cell during the calcium paradox, a condition induced by perfusing the heart with calcium containing buffer following a period of calcium free perfusion. However, little taurine effluxes the hearts exposed to buffer whose pH was lowered to 6.6. Isolated neonatal cardiomyocytes subjected to chemical hypoxia also lost large amounts of taurine. However, the amount of taurine leaving the cells appeared to be correlated with the intracellular sodium concentration, [Na(+)](i). The data suggest that taurine efflux is regulated by [Na(+)](i) and cellular osmolality, but not by cellular pH.