Aim. The paper studies the dynamics of the indicators defi ning the antioxidant system (AOS) and endogenous intoxication in patients with microbial eczema (ME) prior to and following treatment.Materials and methods. The experimental group consisted of patients with ME (n=30) and the control group comprising somatically healthy individuals (n=30). In this study, we determined the components of the antioxidant defence system in blood plasma and erythrocyte suspension, as well as assessed endogenous intoxication.Results. The study revealed an imbalance of indicators refl ecting the severity of oxidative stress and endogenous intoxication in patients suffering from ME. Prior to receiving treatment, the experimental group, as compared to the control group, exhibited an increase in catalase activity (CAT) up to 35.93 [32.50; 38.22] mmol / (min • l) (p < 0.001) and glutathione peroxidase (GPx) up to 1194.27 [1069.50; 1375.78] μmol / (min • l) (p < 0.001). In addition, there was a decrease in the activity of superoxide dismutase (SOD) to 13.28 [11.35; 14.10] u/l (p < 0.001), glutathione reductase (GR) to 501.46 [479.77; 542.52] mmol / (min • l) (p < 0.001) and the concentration of reduced glutathione to 1.64 [1.59; 1.78] μmol / ml (p = 0.043). We observed no statistically signifi cant changes in the total antioxidant activity (TAA) of blood plasma (0.59 [0.55;0.62] mg/l; р = 0.375) and the sulphhydryl groups (0.44 [0.41;0.47] ODU; р =0.111). The patients with ME exhibited the syndrome of endogenous intoxication (SEI), accompanied by an increase in the content of medium and low molecular weight molecules in plasma to 12.19 [11.20; 13.37] arb. u. (p < 0.001), with their content in erythrocytes being relatively normal – 15.23 [14.26; 16.44] arb. u. (p = 0.005). Following the treatment, changes in the studied parameters were of a multidirectional character in relation to the control values. An increased level of CAT and GPx (р <0,001), as well as lower values of SOD and GR, continued to be observed (р < 0.001). The TAA in serum (p = 0.308), sulphhydryl groups (p = 0.111) and reduced glutathione (p = 0.107) did not differ signifi cantly from the control values. The treatment did not reverse the SEI: the content of medium and low molecular weight molecules continued to increase in both plasma and erythrocytes, as compared to the control values (p < 0.001 in both cases).Conclusion. The obtained data confi rm the failure of mechanisms underlying antioxidant defence in patients with ME. Despite the attempt of its compensation by increasing the catalase activity, SOD control values were still not reached. An increase in the GPx activity along with a decrease in GR was observed, which could have lead, in turn, to a decrease in the concentration of reduced glutathione. The failure of the antioxidant defence mechanisms is also indicated by an increase in the content of medium and low molecular weight molecules, as well as by the development of the SEI, resulting from the excessive formation of reactive oxygen species and the inability of the antioxidant system to neutralise them.
A frogspawn-like Ag@C core–shell structure for an ultrasensitive label-free electrochemical immunosensing of carcinoembryonic antigen in blood plasma