The Effect of Selenium Supplementation in the Prevention of DNA Damage in White Blood Cells of Hemodialyzed Patients: A Pilot Study

Patients with chronic kidney disease (CKD) have an increased incidence of cancer. It is well known that long periods of hemodialysis (HD) treatment are linked to DNA damage due to oxidative stress. In this study, we examined the effect of selenium (Se) supplementation to CKD patients on HD on the prevention of oxidative DNA damage in white blood cells. Blood samples were drawn from 42 CKD patients on HD (at the beginning of the study and after 1 and 3 months) and from 30 healthy controls. Twenty-two patients were supplemented with 200 μg Se (as Se-rich yeast) per day and 20 with placebo (baker's yeast) for 3 months. Se concentration in plasma and DNA damage in white blood cells expressed as the tail moment, including single-strand breaks (SSB) and oxidative bases lesion in DNA, using formamidopyrimidine glycosylase (FPG), were measured. Se concentration in patients was significantly lower than in healthy subjects (P < 0.0001) and increased significantly after 3 months of Se supplementation (P < 0.0001). Tail moment (SSB) in patients before the study was three times higher than in healthy subjects (P < 0.01). After 3 months of Se supplementation, it decreased significantly (P < 0.01) and was about 16% lower than in healthy subjects. The oxidative bases lesion in DNA (tail moment, FPG) of HD patients at the beginning of the study was significantly higher (P < 0.01) compared with controls, and 3 months after Se supplementation it was 2.6 times lower than in controls (P < 0.01). No changes in tail moment was observed in the placebo group. In conclusion, our study shows that in CKD patients on HD, DNA damage in white blood cells is higher than in healthy controls, and Se supplementation prevents the damage of DNA

Peroksydaza głutationowa selenozależny enzym z łożyska ludzkiego: oczyszczanie i niektóre właściwości

Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej naukę

Cechy użytkowe i aspekty higieniczne lamp ledowych (LED)

Aim of the study: The aim of this study was to identify characteristics of the LED lamps and their influence on perceptual abilities and feeling of a human. Materials and methods: Technical parameters of ten chosen LED sources of light were determined. The sources varied among each other, according to the shape, colour temperature, colour rendering index and also name of the manufacturer. For each of the analysed sources of light, the illuminance, lighting uniformity, lighting luminance and degree of glare were determined. Moreover, also a subjective evaluation of the lighting conditions created by those lighting sources was performed. Results and conclusions: The study results have shown that the majority of the analysed sources of light provided their users with a good visibility and comfort of vision, but on the other hand, if used in an inappropriate way, they may be the reason for the unaccepted glare. It has been stated that the appropriate use and earlier – the well-thought-out choice of the LED sources of light are crucial. One has to consider the luminous flux, the colour temperature, the shape, as well as the manufacturer, who guarantees the quality and the safety class of the LED source of light.Cel badań: Celem badań było poznanie właściwości ledowych źródeł oświetleniowych i ich wpływu na możliwości percepcyjne człowieka oraz jego samopoczucie. Materiał i metodyka badań: Określono parametry techniczne dziesięciu, wybranych źródeł LED, różniących się między sobą kształtem, mocą, temperaturą barwową, wskaźnikiem oddawania barw, a nawet marką producenta. Dla każdego, badanego źródła wyznaczono natężenie oświetlenia, równomierność oświetlenia, luminancję świetlną oraz stopień olśnienia, a także dokonano subiektywnej oceny warunków oświetlenia, stwarzanych przez te źródła. Wyniki i wnioski: Wykazano, że większość z badanych źródeł LED zapewnia dobrą widoczność i wygodę widzenia, ale jednocześnie przy nieprawidłowym stosowaniu może być powodem nieakceptowalnego olśnienia. Stwierdzono, że bardzo istotne jest prawidłowe użytkowanie oraz wcześniej – przemyślany wybór źródła LED, biorący pod uwagę strumień świetlny, temperaturę barwową, kształt, a tak- że markę producenta, która gwarantuje jakość i klasę bezpieczeństwa źródła LED

Red blood cell and plasma glutathione peroxidase activities and selenium concentration in patients with chronic kidney disease: A review

The metabolism of oxygen in aerobic organisms leads to generation of reactive oxygen species (ROS). These entities are able to oxidize almost all classes of macromolecules, including proteins, lipids and nucleic acids. The physiological level of ROS is usually regulated by antioxidant defense mechanisms. There are at least three groups of antioxidant enzymes: superoxide dismutases, catalases and glutathione peroxidases (GSH-Pxs) which neutralize ROS. The trace elements (copper, zinc and selenium) bound to the active sites of the above listed enzymes play an important role in the antioxidant defense system. In mammals, a major function of selenium (Se) and Se-dependent GSH-Pxs is to protect cells from oxidative stress. Selenium concentrations and GSH-Px activities are altered in blood components of chronic kidney disease (CKD) patients. The Se level is frequently lower than in healthy subjects and the concentration very often decreases gradually with advancing stage of the disease. Studies on red cell GSH-Px activity in CKD patients reported its values significantly lower, significantly higher and lower or higher, but not significantly as compared with healthy subjects. On the other hand, all authors who studied plasma GSH-Px activity have shown significantly lower values than in healthy subjects. The degree of the reduction decreases gradually with the progression of the disease. High inverse correlations were seen between plasma GSH-Px activity and creatinine level. A gradual decrease in plasma GSH-Px activity in CKD patients is due to the fact that this enzyme is synthesized predominantly in the kidney and thus the impairment of this organ is the cause of the enzyme's lower activity. Se supplementation to CKD patients has a slightly positive effect in the incipient stage of the disease, but usually no effect was observed in end-stage CKD. Presently, kidney transplantation is the only treatment that may restore plasma Se level and GSH-Px activity in patients suffering from end-stage CKD. A few studies have shown that in kidney recipients, plasma Se concentration and GSH-Px activity are restored to normal values within a period of 2 weeks to 3 months following surgery and thus it can be acknowledged that Se supplementation to those patients has a positive effect on plasma GSH-Px activity

Infrasound and low frequency noise assessment at workplaces and environment – review of criteria

Infrasound and low frequency noise assessment at workplaces and environment - review of criteria Number of anthropogenic sources of infrasounds and low frequency noise is increasing, therefore it is followed by both increasing exposure level and number of persons exposed to this noise. Criteria of low frequency noise assessment is one of the problem needed to be solved. The paper presents existing polish and international criteria of assessment low frequency noise at workplaces and human setting

Selenium, glutathione and glutathione peroxidases in blood of patients with chronic liver diseases.

Disturbances in the antioxidant system could play a role in pathogenesis of chronic liver disease. The aim of our study was to evaluate the levels/activities of antioxidants in blood of patients with chronic liver disease. We estimated selenium and glutathione concentrations and glutathione peroxidase activities in blood of 59 patients with chronic hepatitis B or C virus infection (group 1) and 64 patients with alcoholic, autoimmune or cryptogenic chronic liver disease (group 2). The results were compared with 50 healthy controls. Whole blood and plasma selenium and red cell glutathione concentrations were significantly lower in the patients compared with the controls. Red cell glutathione peroxidase activity was slightly reduced in both subgroups of group 1 and in group 2 with normal alanine aminotransferase values. Plasma glutathione peroxidase activity was slightly but significantly higher in patients with elevated aminotransferase values. The findings suggest that disturbances in antioxidant parameters in blood of patients with chronic liver disease may be the cause of the peroxidative damage of cells