Selenium, selenoprotein P, and oxidative stress levels in SARS-CoV-2 patients during illness and recovery.

BACKGROUND: This study aimed to assess tendency of oxidative stress in COVID-19 patients depending on severity. METHODS: The study was conducted with 80 post-COVID-19 disease patients and 40 acutely ill patients. Content of selenium in blood plasma was detected by a fluorimetric method with di-amino-naphthalene using acidic hydrolysis. Selenoprotein P, malondialdehyde and 4-hydroxynonenal and their metabolite adducts were evaluated by spectrophotometric methods using commercial assay kits. RESULTS: Obtained results showed that selenium content in blood for post-COVID-19 disease patients was of a similar lower norm for Latvian inhabitants. Selenium and seleno-protein P contents for acute patients were significantly decreased compared with post-COVID-19 disease patients. CONCLUSION: In conclusion, COVID-19 involves induction of antioxidant systems-in case of severe disease, patients have significantly low concentration of selenium, seleno-protein P and higher level of oxidative stress, which, in turn, confirms the more intense formation of free radicals in the body.

Chronic hepatitis C: quantitative EPR analysis of nitrogen oxide and copper in patients' blood.

Measurements of nitrogen oxide and copper in the blood of 57 patients with chronic viral hepatitis C was carried out before antiviral therapy by electron paramagnetic resonance on a Radiopan EPR spectrometer. The results indicate elevated levels of nitrogen oxide and copper in the blood of these patients in comparison with normal subjects. Comparison of these findings with the results of a previous analysis of redox status of patients with chronic viral hepatitis C indicate that this disease is characterized by a significant pro-oxidant shift in the realization of redox processes and disorders in the metal ligand homeostasis (at least as regards copper).

[Assessment of some oxidative stress parameters in bronchial asthma patients beyond add-on selenium supplementation].

The goal of this study was to investigate the effect of selenium deficit replenishment in patients with bronchial asthma (BA) on manifestations of oxidative stress and conditions of the antioxidant system (AOS). The need of correction of selenium deficit in BA-patient is determined by the increased needs in antioxidants due to chronic inflammatory process responcible for pathogenesis of BA. Latvia and also Eastern Finland, Byelorussia, some regions of Ukraine, some regions of the NorthWestern Russia, New Zealand belong to endemic areas with marked selen deficit in soils and foodstuff. Twenty patients (7 men and 13 women) with selen deficit and verified diagnosis of BA have been examined. In addition to basic therapy all patients received organic selenium SelenoPRECISE, ("PharmaNord") 200 microg daily for 16 weeks. This caused statistically significant increase of plasma selenium from 50.94+/-7.58 microg/l to 63.59+/-10.87 microg/l (p<0.001), the increase of selenium-dependent glutathione peroxidase (from 38.64+/-10.72 U/g Hb to 58.57+/-14.64 U/g Hb, p<0.001). Treatment of patients with selenium also normalized parameters charecterizing oxidative stress (chemiluminescence). The use of selenium in addition to basic therapy allows to abolish or alternate manifestations of oxidative stress by correcting the antioxidant system.

Plasma NO-binding activity in patients with hematological malignancies: suppressive effect of glucocorticoids.

Plasma NO-binding activity was studied in patients with various forms of hematological malignancies. The method used in the study quantitatively evaluated the plasma capacity to bind NO, which reflects the intensity of NO production and the degree of patient's stress resistance. Plasma NO-binding activity significantly decreases in patients with hematological malignancies. Glucocorticoid treatment promotes the decrease in plasma NO-binding activity, which was dose-dependent.

Antioxidant defense and trace element imbalance in patients with postradiation syndrome: first report on phase I studies.

More than 6000 residents of Latvia were involved in recovery work in Chernobyl. They were healthy men exposed to substantial ionizing radiation (0.01-0.5 Gy). Now, these recovery workers suffer from "postradiation syndrome": dizziness and poor memory, headache, local pains, and so forth. The biochemical mechanism of "postradiation syndrome" has not been completely established. In this Phase I study, we have investigated how exposure to radiation impacts antioxidative defense and trace element concentrations in the blood of recovery workers. Thirty-five patients with postradiation syndrome (men, age range 33-50 yr) and 15 healthy men similar in age as control subjects were studied for the effects on plasma chemiluminescence, the activity of antioxidant enzymes, and the concentration of ceruloplasmin and concentrations of selenium (Se), zinc (Zn), and copper (Cu) in blood. The results revealed that plasma chemiluminescence was significantly increased (3.5-fold to 5.5-fold), the activity of catalase in erythrocytes was significantly elevated, and the activity of glutathione peroxidase in plasma was significantly reduced in examined patients. Concentrations of Zn and Cu were significantly higher and the concentration of Se was lower in these patients. We conclude that the patients exposed to ionizing radiation have diminished blood antioxidant defense associated with pronounced Se deficiency and imbalance of Zn and Cu.

Anaemia and antioxidant defence of the red blood cells.

Antioxidant defence was investigated in red blood cells (RBC) in 56 patients with 3 different haemoblastoses: polycythemia vera (PV), chronic myelogenous leukaemia (CML), chronic lymphoid leukemia (CLL) with and without anaemia, in 12 iron deficiency anaemia (A) patients and 50 healthy persons. The activities were determined of the following antioxidant enzymes: glucose-6-phosphate dehydrogenase (G6PD), glutathione reductase (GSSG-R), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and MDA levels. Antioxidant defence is decreased and the level of lipid peroxidation are increased in RBC in all patients (PV, CML, CLL, A). Different changes were detected in the antioxidative defence between normal red blood cells and those formed from leukaemic cells clone. In normal RBC in anaemia (CLL, A) opposite deviation of G6PD and GSSG-R activities was observed. In RBC formed from leukaemic cell clone (PV, CML), a simultaneous significant increase in G6PD and GSSG-R activities was found, which indicated activisation of pentose phosphate pathways (PPP) in these pathologies; in anaemia they function less effectively.