In this article, a series of silver-containing dressings are prepared by metal-vapor synthesis (MVS), and their antibacterial properties are investigated. The antibacterial activity of the dressings containing silver nanoparticles (AgNPs) against some Gram-positive, and Gram-negative microorganisms (Staphylococcus aureus, Staphylococcus haemolyticus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Moraxella spp.) has been determined. Based on the plasmon resonance frequency of these nanoparticles, the frequency of laser irradiation of the dressing was chosen. The gauze bandage examined showed pronounced antibacterial properties, especially to Staphylococcus aureus strain. When 470 nm laser radiation, with a power of 5 mW, was applied for 5 min, 4 h after inoculating the Petri dish, and placing a bandage containing silver nanoparticles on it, the antibacterial effect of the latter significantly increased—both against Gram-positive and Gram-negative microorganisms. The structure and chemical composition of the silver-containing nanocomposite were studied by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS). The synthesized AgNPs demonstrate narrow and monomodal particle size distribution with an average size of 1.75 nm. Atoms of metal in Ag/bandage system are mainly in Ag0 state, and the oxidized atoms are in the form of Ag-Ag-O groups.
Objective. To study the effect of thermal skin burns in experimental animals (rats) on the state of the system “mother-fetus” in a late gestation period.Materials and methods. An experimental study was carried out on 18 female outbred white rats weighing 300–350 g (per 9 rats in the control and experimental groups), which were exposed to third-degree thermal burns with an area of 12 cм2 in a late gestation period. The oxygen transport function and the main blood biochemical markers were studied. The effect of thermal injury on the course of pregnancy was studied.Results. The thermal skin burn in the rats in the late gestation period leads to the development of hypoxia, a decrease in the affinity of hemoglobin for oxygen and metabolic acidosis in the mother’s body. Changes in the blood biochemical markers indicate the presence of endogenous intoxication. In the experimental animal group, a decrease in fetal weight was observed, an increase in the post-implantation fetal death rate was noted.Conclusion. Impaired oxygen homeostasis and endogenous intoxication in skin burns in rats in late gestation periods lead to fetal malnutrition and a qualitative increase in the post-implantation fetal death rate.
Background. In modern medicine, the problem of treating thermal skin burns in pregnant women remains relevant due to insufficient research of pathological processes occurring in the body of a future mother suffering from thermal injury. The aim of the research. To assess the state of homeostasis in rats with thermal skin burns in the middle period of pregnancy. Material and methods. An experimental study was carried out on 36 female outbred white rats weighing 250-350 g, which underwent thermal skin burns in the middle period of pregnancy. The processes of lipid peroxidation and the total content of nitrate / nitrites were studied, the oxygen transport function of the blood and the main biochemical parameters of the blood were assessed. Results. Thermal skin burn in rats in the middle period of pregnancy leads to the development of hypoxia, as judged by the decrease in pO2 and SO2 values, as well as a decrease in the affinity of hemoglobin for oxygen. At the same time, oxidative stress develops, and an increase in the content of nitrate / nitrites is also observed, which reflects the dysfunction of the L-arginine-NO system, causing changes in the oxygen-binding properties of the blood and forming a prooxidant-antioxidant imbalance. Changes in the main biochemical parameters of blood confirm the presence of endogenous intoxication. Conclusions. The revealed violations of homeostasis in pregnant rats with thermal skin burns indicate the important role of oxygen-dependent processes in the pathogenesis of thermal injury, which must be taken into account when developing appropriate measures aimed at eliminating violations in this pathology.
Background. Metal nanoparticles can have unique properties that differ from those of the solid metal from which they are obtained. This is what determines the increased interest in them on the part of researchers from all over the world. Objective of the study: quantitative assessment of the antibacterial effect of silver and zinc oxide nanoparticles on polyantibiotic-resistant strains of gram-positive and gram-negative microorganisms. Material and methods. The synthesis of silver and zinc oxide nanoparticles was performed by laser ablation in a liquid. The physical properties and sizes of these nanoparticles were studied on the basis of spectral characteristics and atomic force microscopy. The study of the antibacterial resistance of the studied microorganisms was carried out, as well as a quantitative assessment of the antibacterial effect of the obtained nanoparticles based on the determination of the minimum inhibitory and minimum bactericidal concentrations. Results. All microorganisms used in the study were clinical pathogenic strains with polyantibacterial resistance. In this case, the minimum inhibitory concentrations of silver nanoparticles ranged from 7.81 to 31.25 μg/ml, and the minimum bactericidal concentrations - from 31.25 to 62.50 μg/ml, while for zinc oxide nanoparticles the values of the minimum inhibitory concentrations were within the range from 125 to 500 μg/ml, and the values of the minimum bactericidal - from 250 to 1000 μg/ml. Conclusions. The laser ablation method allows the synthesis of chemically pure nanoparticles of silver, zinc oxide, and, if necessary, other metals. Silver and zinc oxide nanoparticles are effective antimicrobial agents against polyantibiotic-resistant pathogenic microbial flora. The obtained values of the minimum bactericidal and minimum inhibitory concentrations must be taken into account in the subsequent clinical implementation of medical devices based on the use of metal nanoparticles.
Purpose. To evaluate the effectiveness of open methods of surgical treatment of inguinal hernia in elderly patients. Material and methods. The study includes 336 elderly patients with inguinal hernias. The Bassini hernioplasty was performed on 106 patients, the Liechtenstein technique was applied to 110 patients and the new tension-free method – to 120 patients. The effectiveness of hernioplasty was evaluated according to the results of the examination of patients in the early and remote postoperative periods, as well as the methodology for calculating the effectiveness of medical technologies in healthcare. Results. With open surgical interventions in patients with inguinal hernias in the early postoperative period there is an increase in the volume of the testicle on the side of surgery. In the remote period only after the Lichtenstein hernioplasty there was a decrease in the volume of the testicle (p<0.05). The relapse of the hernia (1-3 years later) after the Bassini hernioplasty took place in 9.4% cases, after the Liechtenstein hernioplasty - in 3.6% patients, and after applying the new method of hernioplasty there was no relapse of hernia. The new technique of tension-free hernioplastics was characterized by the highest level of medical (Km=1.00) and social efficiency (Ks=0.86). Conclusion. The new technique of open tension-free inguinal hernioplasty is characterized by the highest level of medical and social efficiency.
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