Thiol-Functional Polymer Nanoparticles via Aerosol Photopolymerization

Spherical, individual polymer nanoparticles with functional –SH groups were synthesized via aerosol photopolymerization (APP) employing radically initiated thiol-ene chemistry. A series of various thiol and alkene monomer combinations were investigated based on di-, tri-, and tetrafunctional thiols with difunctional allyl and vinyl ethers, and di- and trifunctional acrylates. Only thiol and alkene monomer combinations able to build cross-linked poly(thio-ether) networks were compatible with APP, which requires fast polymerization of the generated droplet aerosol during the photoreactor passage within a residence time of half-minute. Higher monomer functionalities and equal overall stoichiometry of functional groups resulted in the best nanoparticles being spherical and individual, proven by scanning electron microscopy (SEM). The presence of reactive—SH groups in the synthesized nanoparticles as a basis for post-polymerization modifications was verified by Ellman’s test.

Potentials of intravenous laser blood irradiation to correct peroxidation and antioxidant activity as a result of surgical distress

Purpose: to reveal protective effects of intravenous low-level laser blood irradiation (ILBI) during surgical interventions at the gallbladder as well as to study the state of antioxidant activity, lipid peroxidation and endogenous intoxication.Material and methods. In the perioperative period, 40 patients from the main group (I) had traditional treatment which included pharmacological preparations and sessions of intravenous laser blood irradiation. 45 patients from the control group (II) had only traditional (pharmacotherapeutic) treatment. In both groups during surgery, the anesthetic protection consisted of classical neuroleptanalgesia. The age of patients in both groups did not differ significantly. Intravenous laser blood irradiation was done with helium-neon laser “Atoll” 632 nm (Fokon Ltd, St-Petersburg, Russia). During surgery, three irradiation sessions were performed at radiation power of 20 mW and exposure 15 minutes at various stages of surgery: 30 minutes before induction of anesthesia, at the traumatic stage and 30 minutes before the expected finish of the surgery. Ceruloplasmin and transferrin levels in the blood plasma were assessed with the electron paramagnetic resonance technique. The ratio of ceruloplasmin/transferrin which characterizes the level of antioxidant activity was also established. The level of endogenous intoxication was assessed using the previously published technique. The quantitative characteristics of endogenous intoxication by this technique is the value of optical density (D280) and total optical density of components related to high molecular weight and low molecular weight fractions.Results. ILBI sessions in patients neutralize changes in the level of ceruloplasmin and transferrin in blood. The data obtained also confirm ILBI protective effects at protein SH-groups or activation of the restoration of protein SH-groups that were damaged by oxidation as a result of surgical aggression and trauma.Conclusion. The protective effect of intravenous laser blood irradiation in addition to the standard preoperative therapy optimizes pharmacological anesthetic protection during surgery under the existing traditional schemes of combined general anesthesia.

Antioxidative and Oxidative Profiles in Plasma and Saliva in Dairy Cows during Pregnancy

Increased metabolism that occurs during pregnancy can result in oxidative stress which is harmful to cells and, consequently, for the proper functioning of the whole organism. Plasma and recently also saliva are important resources for evaluating physiological and pathological conditions in animals. The study aimed to investigate the influence of the metabolic state on the effectiveness of the antioxidant profile of plasma and saliva during the pregnancy of cows. Seventy-six healthy pregnant and twelve non-pregnant control cows were included in the study. Blood and saliva samples were collected each month of the pregnancy course. Examined body fluids were used to evaluate both the total antioxidant capacity (TAC) and the oxidative parameters related to protein and lipid peroxidative processes. TAC, the content of hydroperoxides, and SH groups were determined spectrophotometrically while formylokinurenine and bityrosine contents were measured spectrofluorimetrically. The results showed dynamic changes depending on the period of pregnancy course. The highest antioxidant activity in plasma was mostly noted in early pregnancy and advanced pregnant cows. All tested parameters except SH groups expressed higher values in saliva compared to plasma. Obtained results reveal that the increase in oxidative intensity induced appropriate answers of cells reflected in the increase in antioxidative activity of the organism. Moreover, some examined parameters can indicate the intensity of oxidative stress and therefore could be used in a panel of markers of the physiological course of pregnancy. However, with regards to antioxidant/oxidative parameters, saliva reflects the content of plasma only in part, due to the local metabolism of the salivary gland. Further studies are necessary to establish physiological ranges of antioxidative/oxidative profiles in cows and to define the usefulness of saliva as biological material in oxidative stress diagnostics.

Memantine Modulates Oxidative Stress in the Rat Brain following Experimental Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is an animal model most commonly used in research on the pathomechanisms of multiple sclerosis (MS). The inflammatory processes, glutamate excitotoxicity, and oxidative stress have been proposed as determinants accompanying demyelination and neuronal degeneration during the course of MS/EAE. The aim of the current study was to characterize the role of NMDA receptors in the induction of oxidative stress during the course of EAE. The effect of memantine, the uncompetitive NMDA receptor antagonist, on modulation of neurological deficits and oxidative stress in EAE rats was analyzed using several experimental approaches. We demonstrated that the expression of antioxidative enzymes (superoxide dismutases SOD1 and SOD2) were elevated in EAE rat brains. Under the same experimental conditions, we observed alterations in oxidative stress markers such as increased levels of malondialdehyde (MDA) and decreased levels of sulfhydryl (-SH) groups, both protein and non-protein (indicating protein damage), and a decline in reduced glutathione. Importantly, pharmacological inhibition of ionotropic NMDA glutamate receptors by their antagonist memantine improved the physical activity of EAE rats, alleviated neurological deficits such as paralysis of tail and hind limbs, and modulated oxidative stress parameters (MDA, -SH groups, SOD’s). Furthermore, the current therapy aiming to suppress NMDAR-induced oxidative stress was partially effective when NMDAR’s antagonist was administered at an early (asymptomatic) stage of EAE.

Prevention of recurrence of endometrial polyps in women of reproductive age

The objective: the optimization of management of women in reproductive age after removal of endometrial polyps based on the study of the antioxidant status of the organism.Materials and methods. We examined 150 women in reproductive age with endometrial polyps, 65 (43.3%) patients of them were diagnosed with glandular polyp, 85 (56.7%) – with glandular fibrous polyps. 110 patients after polypectomy were divided into three clinical groups: the first group (32 (29.1%) women) did not receive anti-relapse therapy, the second group (36 (32.7%) persons) used dydrogesterone, the third group (42 (38.2%) women) – received complex drug anti-recurrence therapy (thioctic acid preparation, ascorbic acid, α-tocopherol acetate, indole-3-carbinol). In all women, the antioxidant indicators in blood and the presence of recurrent polyps were determined in 12 months after the treatment. Results. Before polypectomy in patients with endometrial polyps, a decrease of indicators of antiradical activity by 28.52%, restored forms of non-protein SH-groups – by 16.46%, protein SH-groups – by 25.31%, ascorbic acid – by 27.04%, α-tocopherol – by 21.62%, the value of the integral indicator of antioxidant protection – by 31.01% were found compared to the persons in the control group, as well as an increase in the concentration of malonic dealdehyde by 37.23%, non-protein SS groups – by 43.48%, protein SS-groups - by 29.43% and oxidized forms of ascorbic acid – by 29.68%.In 12 months after polypectomy, recurrence of the pathology was in 21.9% of patients of the first group, in 16.7% – of the second group, and no recurrence was detected in women in the third group.Conclusions. In patients with endometrial polyps there are a decrease in level of components of antioxidant protection in the organism and the expressed intensification of processes of free radical and peroxide oxidation of lipids. The use of a comprehensive approach that combines the polypectomy with the use of antioxidant drugs in the postoperative period, in such patients allows to prevent a recurrence of the pathology.

Benefits of D-005, a lipid extract from Acrocomia crispa fruits, in the prevention of acute kidney njury induced by nephrotoxicity in rats

Introduction: Aminoglycoside-induced acute kidney injury (AKI) is a pathology closely linked to oxidative and inflammatory reactions. Taking into account the previous reported antioxidant and anti-inflammatory effects of D-005, a lipid extract obtained from Cuban palm Acrocomia crispa (Arecaceae) fruits, this work aimed to evaluate the effects of D-005 on kanamycin-induced AKI. Methods: Male Wistar rats were divided into 7 groups: negative control (vehicle, Tween 65/H2O) and six groups treated with kanamycin to induce AKI: positive control (vehicle), D-005 (25, 100, 200, and 400 mg/kg) and grape seed extract (GSE, 200 mg/kg). D-005, vehicle, and GSE oral treatments were administered once daily for seven days, 1 h before kanamycin (500 mg/kg, i.p.). Serum uric acid and urea concentrations, renal histopathology, and oxidative markers (malondialdehyde (MDA), sulfhydryl (SH) groups, and catalase (CAT) activity) were assessed. Results: D-005 significantly reduced uric acid and urea levels, starting from D-005 100 mg/kg. Histopathologically, D-005, at all the tested doses, protected renal parenchyma structures (glomeruli, proximal tubules, and interstitium). These findings were accompanied by a significant reduction of MDA and SH group concentrations as well as restoration of CAT activity. The highest percentages of inhibition were obtained with the dose of 400 mg/kg. GSE, the reference substance, also prevented kanamycin-induced biochemical and histopathological changes, as well as reduced MDA and SH groups and restored CAT activity. Conclusion: The administration of repeated oral doses of D-005 significantly protected against kanamycin-induced AKI, which could be associated with the antioxidant and anti-inflammatory effects of this extract.

Therapeutic irradiation in the management of gynecological cancer and predictability of radiation-induced complications

Background. Today, applying radiotherapy (RT) in management of both primary and secondary vaginal cancer (SVC) take pride of place in the spectrum of specialized treatments for cancer patients. Secondary vaginal tumors are more common (6% to 33%) in cervical cancer (CC) patients, while in uterine cancer (UC) occur in 8–10% of cases treated either surgically, or by means of radiotherapy, otherwise via a combination approach. Therefore, RT is administered in about 80% of primary vaginal cancer and particularly SVC patients. When using even the most advanced radiotherapy equipment implying the cutting-edge technologies, there is a risk of radiation-induced complications in healthy organs and tissues that fall under the irradiation area. Keeping in mind the key radiobiological paradigms makes it possible not only to predict the probability of tumor resorption upon radiation exposure, but also to assess the biological effectiveness of absorbed dose, as well as the risk of late radiation complications. Purpose – to enhance the effectiveness and assess the toxicity of SVC RT via ascertaining BT (brachytherapy) most suitable techniques depending on the type of ionizing radiation and exploring predictability of radiation-induced complications in terms of biomolecular cell properties. Materials and methods. Clinical study was performed at the National Cancer Institute Clinic (Radiation Oncology Department), using a high-energy BT unit with a HDR 192Ir source. The SVC patients (n = 106) were treated according to the developed BT methods. They had been pretreated for the CC (n = 65) with squamous cell carcinoma histologically diagnosed in the most cases or UC (n = 41) with histologically prevalent adenocarcinoma of a variable grade. Patients had a locally advanced pelvic tumor process with tumor staging II–III, T2-3N0-1M0. Along with clinical study the radiobiological research was conducted to count the apoptotic cells in both intact and irradiated peripheral blood lymphocytes (PBL), as well as the level of SH-groups of plasma proteins and peptides in gynecological cancer patients and healthy donors to predict the risk of radiation-induced complications. Results and discussion. Given the delayed effect of RT, the treatment effective- ness was analyzed immediately after RT session and also 3 months upon completion of the conservative therapy. Thus, positive tumor response upon three months of observation over time was registered in 67.9 ± 5.2% of patients in study group I, in 72.5 ± 6.9% in study group II, and in 51.3 ± 6.8% in comparison group. Hence the values in study groups were higher than in comparison group by 16.6% and 21.2% respectively. All patients tolerated BT satisfactorily. Neither general nor local rectum or bladder severe (above grade II) toxicities were noted both during treatment and over the next 3 months upon its completion in all the patients regardless of study group. Results obtained in radiobiological studies correlated with clinical and literature data. Conclusions. Decrease in manifestations of RT toxicity, namely of the ear- ly radiation reactions from interfacing critical organs was established in groups I and II vs comparison group I, especially in group I where a high- energy 192Ir source was used in the SBD irradiation mode of 3 Gy twice a week. The obtained results of the experimental study suggest that the content of SH-groups in blood plasma and the level of PBL apoptosis can be considered as additional predictive measures of radiosensitivity of non-malignant cells from the irradiated tumor environment.

Extra-platelet low-molecular-mass thiols mediate the inhibitory action of S-nitrosoalbumin on human platelet aggregation via S-transnitrosylation of the platelet surface

Nitrosylation of sulfhydryl (SH) groups of cysteine (Cys) moieties is an important post-translational modification (PTM), often on a par with phosphorylation. S-Nitrosoalbumin (ALB-Cys34SNO; SNALB) in plasma and S-nitrosohemoglobin (Hb-Cysβ93SNO; HbSNO) in red blood cells are considered the most abundant high-molecular-mass pools of nitric oxide (NO) bioactivity in the human circulation. SNALB per se is not an NO donor. Yet, it acts as a vasodilator and an inhibitor of platelet aggregation. SNALB can be formed by nitrosation of the sole reduced Cys group of albumin (Cys34) by nitrosating species such as nitrous acid (HONO) and nitrous anhydride (N2O3), two unstable intermediates of NO autoxidation. SNALB can also be formed by the transfer (S-transnitrosylation) of the nitrosyl group (NO+) of a low-molecular-mass (LMM) S-nitrosothiol (RSNO) to ALB-Cys34SH. In the present study, the effects of LMM thiols on the inhibitory potential of ALB-Cys34SNO on human washed platelets were investigated. ALB-Cys34SNO was prepared by reacting n-butylnitrite with albumin after selective extraction from plasma of a healthy donor on HiTrapBlue Sepharose cartridges. ALB-Cys34SNO was used in platelet aggregation measurements after extended purification on HiTrapBlue Sepharose and enrichment by ultrafiltration (cutoff, 20 kDa). All tested LMM cysteinyl thiols (R-CysSH) including l-cysteine and L-homocysteine (at 10 µM) were found to mediate the collagen-induced (1 µg/mL) aggregation of human washed platelets by SNALB (range, 0–10 µM) by cGMP-dependent and cGMP-independent mechanisms. The LMM thiols themselves did not affect platelet aggregation. It is assumed that the underlying mechanism involves S-transnitrosylation of SH groups of the platelet surface by LMM RSNO formed through the reaction of SNALB with the thiols: ALB-Cys34SNO + R-CysSH ↔ ALB-Cys34SH + R-CysSNO. Such S-transnitrosylation reactions may be accompanied by release of NO finally resulting in cGMP-dependent and cGMP-independent mechanisms.

Plasma oxalic acid as a trigger for oxidative processes in end-stage renal disease patients

The present study aimed to evaluate the changes in oxidative stress markers according to the concentration of plasma oxalic acid (POx) in end-stage renal disease (ESRD) patients. Methods. We conducted a cross-sectional observational study involving 72 ESRD patients and 30 relatively healthy individuals who served as a control reference group for evaluation of POx concentration. Among ESRD patients there were 32 hemodialysis (HD) patients and 40 peritoneal dialysis (PD). POx concentration was measured spectrophotometrically using a commercially available kit (MAK315, Sigma, Spain). Malonic dialdehyde (MDA), ceruloplasmin (CP), transferrin (TR), sulfhydryl groups (SH-groups), antioxidant blood capacity (AOC) and total peroxidase activity of erythrocytes (TPA) were measured and the oxidative stress index (OSI) was calculated in all examined patients. Results. A significant increase in POx concentration was observed in ESRD patients compared with healthy volunteers (p < 0.0001). The concentrations of MDA in serum, OSI in erythrocytes and serum of the examined patients were gradually increased, while serum levels of CP, AOC, SH-groups and TPA in erythrocytes, on the contrary, were decreased in accordance with the increasing trend of POx concentrations. Correlation analysis demonstrated a statistically significant direct relationship between POx concentration and MDA (r = 0.57; p <0.0001) and OSI (r = 0.64; p <0.0001). The inverse correlation was determined between POx and antioxidant markers: CP (r = -0.35; p = 0.007), SH-groups in serum (r = -0.3; p = 0.04) and erythrocytes (r = -0.53 ; p <0.0001). Conclusions. The intensity of oxidative-antioxidant balance disorders in the blood of ESRD patients has been associated with the POx concentration: the higher the concentration of POx was the more active oxidative processes and the more pronounced lack of antioxidant protective factors occurred. Further studies are needed to determine the role of POx in the initiation of oxidative stress and chronic inflammation in ESRD patients.