Simultaneous determination of cystine and other free aminothiols in blood plasma using capillary electrophoresis with pH-mediated stacking.

We developed a method of sensitive capillary electrophoresis using UV detection for the determination of certain free aminothiols (reduced cysteinylglycine (rCysGly), cysteine (rCys), glutathione (rGln), and cystine (CysS) in human blood plasma. The reduced thiols were derivatized with N-ethylmaleimide. The plasma was purified from proteins via ultrafiltration. Electrophoretic separation was performed using 115 mM Na phosphate with 7.5% (v/v) polyethylene glycol 600, pH 2.3. The in-capillary concentration of the analytes was achieved with a pH gradient created via the preinjection of triethanolamine and postinjection of phosphoric acid. The separation was carried out using a silica capillary (50 µm i.d.; total/effective separation length 42/35 cm) at a 25 kV voltage. The total analysis/regeneration time was 18 min. The quantification limits varied from 1.3 µM (rCysGly) to 5.4 µM (CysS). The accuracy was 95%-99%, and the repeatability and reproducibility were approximately 1.8%-3.8% and 1.9%-5.0%, respectively. An analysis of plasma samples from healthy volunteers (N = 41) showed that the mean levels of rCysGly, rCys, rGln, and CysS were 1.64, 10.6, 2.58, and 46.2 µM, respectively.

Antimicrobial Activity of Citrate-Coated Cerium Oxide Nanoparticles.

The purpose of this study was to investigate the antimicrobial activity of citrate-stabilized sols of cerium oxide nanoparticles at different concentrations via different microbiological methods and to compare the effect with the peroxidase activity of nanoceria for the subsequent development of a regeneration-stimulating medical and/or veterinary wound-healing product providing new types of antimicrobial action. The object of this study was cerium oxide nanoparticles synthesized from aqueous solutions of cerium (III) nitrate hexahydrate and citric acid (the size of the nanoparticles was 3-5 nm, and their aggregates were 60-130 nm). Nanoceria oxide sols with a wide range of concentrations (10-1-10-6 M) as well as powder (the dry substance) were used. Both bacterial and fungal strains (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaris, Candida albicans, Aspergillus brasielensis) were used for the microbiological studies. The antimicrobial activity of nanoceria was investigated across a wide range of concentrations using three methods sequentially; the antimicrobial activity was studied by examining diffusion into agar, the serial dilution method was used to detect the minimum inhibitory and bactericidal concentrations, and, finally, gas chromatography with mass-selective detection was performed to study the inhibition of E. coli's growth. To study the redox activity of different concentrations of nanocerium, we studied the intensity of chemiluminescence in the oxidation reaction of luminol in the presence of hydrogen peroxide. As a result of this study's use of the agar diffusion and serial dilution methods followed by sowing, no significant evidence of antimicrobial activity was found. At the same time, in the current study of antimicrobial activity against E. coli strains using gas chromatography with mass spectrometry, the ability of nanoceria to significantly inhibit the growth and reproduction of microorganisms after 24 h and, in particular, after 48 h of incubation at a wide range of concentrations, 10-2-10-5 M (48-95% reduction in the number of microbes with a significant dose-dependent effect) was determined as the optimum concentration. A reliable redox activity of nanoceria coated with citrate was established, increasing in proportion to the concentration, confirming the oxidative mechanism of the action of nanoceria. Thus, nanoceria have a dose-dependent bacteriostatic effect, which is most pronounced at concentrations of 10-2-10-3 M. Unlike the effects of classical antiseptics, the effect was manifested from 2 days and increased during the observation. To study the antimicrobial activity of nanomaterials, it is advisable not to use classical qualitative and semi-quantitative methods; rather, the employment of more accurate quantitative methods is advised, in particular, gas chromatography-mass spectrometry, during several days of incubation.

Influence of Coronary Artery Bypass Grafts on Blood Aminothiols in Patients with Coronary Artery Disease.

Coronary artery disease (CAD) and the coronary artery bypass graft (CABG) are associated with a decreased blood glutathione (bGSH) level. Since GSH metabolism is closely related to other aminothiols (homocysteine and cysteine) and glucose, the aim of this study was to reveal the associations of bGSH with glucose and plasma aminothiols in CAD patients (N = 35) before CABG and in the early postoperative period. Forty-three volunteers with no history of cardiovascular disease formed the control group. bGSH and its redox status were significantly lower in CAD patients at admission. CABG had no significant effect on these parameters, with the exception of an increase in the bGSH/hemoglobin ratio. At admission, CAD patients were characterized by negative associations of homocysteine and cysteine with bGSH. All these associations disappeared after CABG. An association was found between an increase in oxidized GSH in the blood in the postoperative period and fasting glucose levels. Thus, CAD is associated with the depletion of the intracellular pool and the redox status of bGSH, in which hyperhomocysteinemia and a decrease in the bioavailability of the extracellular pool of cysteine play a role. The present study indicates that CABG causes disruptions in aminothiol metabolism and induces the synthesis of bGSH. Moreover, glucose becomes an important factor in the dysregulation of GSH metabolism in CABG.

The Diagnostic and Prognostic Roles Played by Homocysteine and Other Aminothiols in Patients with Chronic Kidney Disease.

We examined standard clinical and laboratory biochemical parameters, as well as the levels of aminothiols in the blood and urine (homocysteine (Hcy), cysteine (Cys), S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH)) via capillary electrophoresis in patients with CKD at stages II-V. Patient outcomes were assessed after five years. To complete forecasting, correlation and ROC analysis were performed. It was found that the levels of Cys and Hcy in blood plasma were earlier markers of CKD starting from stage II, while the levels of SAM and SAM/SAH in urine made it possible to differentiate between CKD at stages II and III. Blood plasma Hcy and urinary SAM and SAM/SAH correlated with mortality, but plasma Hcy concentrations were more significant. Thus, plasma Hcy, urine SAM, and SAM/SAH can be considered to be potential diagnostic and prognostic markers in patients with CKD.

Oxidative Stress and Free Radical Processes in Tumor and Non-Tumor Obstructive Jaundice: Influence of Disease Duration, Severity and Surgical Treatment on Outcomes.

The aim of this study was to assess the patterns and pattern disruptions of free radical processes in patients with obstructive jaundice of various origins, and the severity of jaundice before and after decompression. Oxidative stress markers were determined in 128 patients with obstructive jaundice with a tumor genesis (23.4%) or non-tumor genesis (76.6%). The patients were hospitalized at different stages of clinical signs of jaundice. We studied the anti-peroxide activity in plasma, basal and stimulated indicators of the chemiluminescence intensity in leukocytes, leukocyte activity coefficients reflecting the level of reactive oxygen species generated by leukocytes, malondialdehyde levels indicative of the degree of lipid peroxidation and cellular destruction, liver enzymes (markers of cytolysis) and bilirubin levels. Data for hepatocyte death and markers of oxidative stress correlated with the severity of jaundice, its duration and the method of its surgical correction. It is proposed that using markers of free radical processes to assess the prognosis and effectiveness of treatment and to personalize treatment measures will improve the results of jaundice treatment.

Application of Polymer Drugs with Cerium Dioxide Nanomolecules and Mesenchymal Stem Cells for the Treatment of Skin Wounds in Aged Rats.

The urgency of the problem of wound healing is not in doubt, given the global trend of an increase in the number of operations and injuries with skin damage, as well as the lack of universal means of treating wounds. STUDY OBJECTIVE: To compare the effectiveness of the developed drugs, smart polymeric nano-drug with cerium oxide nanoparticles (SPN), and smart polymeric nano-drug in combination with mesenchymal stem cells (SPN + SC) on the healing process of skin wounds. MATERIAL AND METHODS: An experimental study was carried out using Wistar rats of post-reproductive age, which had dermis and epidermis removed on their backs. There were four groups of wounds in total: control, treatment with mesenchymal stem cells (SC), SPN, and SPN + SC. RESULTS: A positive therapeutic effect of polymeric drugs on the dynamics of wound area reduction was established, which was most typical for wounds of the SPN group and, particularly, the SPN + SC group. On the third day, an anti-inflammatory effect was revealed in the SC and the SPN + SC groups in particular, which was expressed in a reduced leukocyte infiltration and an increase in the level of microcirculation during this period. The fastest transition from the phase of exudation to proliferation was recorded in the SPN and SPN + SC groups. Histologically, these groups showed faster regeneration, including the epithelialization of wounds. CONCLUSION: The results obtained in the course of the study open up possibilities for the development of fundamentally new, highly effective wound healing agents.

Comparative Analysis of the Effectiveness of Some Biological Injected Wound Healing Stimulators and Criteria for Its Evaluation.

PURPOSE: To investigate the comparative effectiveness of certain biological injectable stimulants for the healing of skin wounds and criteria for its assessment. MATERIALS AND METHODS: A comparative study of the effectiveness of mesenchymal stem cells (SC group), collagen (Collagen group), and deproteinized calf blood hemoderivative (DCBH group) was carried out using an acute wound model. Control wounds were injected with isotonic sodium chloride solution (Control group). A total of four groups (28 wounds per group) were included in the study. Aged male Wistar rats were used as experimental animals. A dynamic assessment of the wound areas and edges, microvasculature assessment via laser Doppler flowmetry, histological and morphometric analyses to determine the quantitative and qualitative fibroblasts composition, as well as the degree of newly synthesized collagen maturity, was conducted on days 0, 3, 7, and 14. RESULTS: The administration of SCs provided a rapid but short-lasting effect, whereas the administration of collagen resulted in a delayed but long-lasting wound-healing effect. DCBH resulted in little to no effect. An increase in the perfusion volume of the wound edges accelerated the regeneration process, while the level of microcirculation did not affect the number and activity of fibroblasts. The wound healing acceleration, as well as the new collagen and stratified epithelium formation and maturation, was associated with the presence of a sufficient pool of mature and active fibroblasts in the wound, and not with the number of fibroblasts. CONCLUSION: The present results clarify the action mechanisms of the studied drugs. In addition, the application purposes and different effects of each drug on the different wound healing phases were demonstrated. An assumption on the multi-component treatment advisability under the wound condition objective assessment possibility was made. Findings from this study may assist clinicians in making an informed transition to personalized wound management and achieve better clinical outcomes.