Temat: selenium - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Determination of Se(IV), Cd(II) and Pb(II) ions in homeopathic drugs by inversion voltammetry method
Autorzy:: Krzek, Jan
Kierszniewska, Anna
Opis:: The conditions for identification and quantification of Se(IV), Cd(II) and Pb(II) ions in homeopathic drugs by inversion voltammetry method with the use of EAGRAPH software were established. The studies proved that the method was of high sensitivity in established conditions. The detection limits were 0.66 μg/mL, 0.08 μg/mL and 0.12 μg/mL for Se(IV), Pb(II) and Cd(II) ions, respectively. This method was characterized by repeatability of measurements, a wide range of linearity and satisfactory percent recovery.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Determination of selenium as a biomarker of thyroid cancer by HG-AFS method
Autorzy:: Wietecha-Posłuszny, Renata
Kościelniak, Paweł
Zagrodzki, Paweł
Dobrowolska-Iwanek, Justyna
Opis:: A simple and versatile procedure has been developed for the determination of selenium in biological samples for clinical purposes. The procedure consists of microwave sample digestion and the determination of selenium using atomic fluorescence spectrometry with a hydride generation system (HG-AFS). The method allows the determination of selenium in a range of 0.5–100.0 $\mu$g $L^{-1}$ with a detection limit not higher than 0.2 $\mu$g $L^{-1}$ and with good repeatability not exceeding 1%. It was applied for determination of selenium in women’s plasma samples (n = 90) with a suspicion of a thyroid cancer and the control group of women (n = 87). Most of the obtained results were in the range 30.0–60.0 $\mu$g $L^{-1}$ and either did not match the physiological level of selenium in human plasma or indicate moderate selenium deficiency. In the further examinations the thyroid tissues taken from 30 patients were analyzed. In most of the cases the selenium concentration was found to be lower (0.14–1.67 $\mu$g $g^{-1}$ wet weight) than its physiological level in a healthy tissue. On this basis the hypothesis has been drawn that selenium can be considered as an additional marker of the thyroid cancer disease.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

Artykuł

na półce

Skocz do pozycji: 3.

Autorzy:: Augustyniak, Małgorzata
Opis:: The protective effect of selenium against colorectal cancer or adenoma is still a controversial issue. Although there are well-described (pato)physiological protective mechanisms of selenium against colorectal cancer, the results of the studies from 1998-2018 are inconclusive and need to be considered in the future. Neither observational nor experimental studies present consistent results. Although the Cochrane review showed that well-designed randomized clinical trials (RCTs) presented no beneficial effect of selenium supplementation on cancer incidence, well-designed RCTs confirming the protective effect of selenium supplementation against colorectal adenoma or colorectal polyp recurrence have been found in subject-related literature. In the reviewed studies, selenium concentration was measured in the blood serum/toenail or in diet. It is of great importance to highlight that blood selenium concentration depends on the concentration of this micronutrient in food, which in turn depends on selenium content in soil, bioavailability of selenium, which is different in various geographical regions, and forms of selenium. Selenium circulating in blood as a component of selenoproteins participates in oxidoreduction, thus reducing the risk of developing colorectal cancer. Despite this well-known protective mechanism against colorectal cancer occurrence, half of the reviewed studies did not confirm the protective properties of selenium. To sum up, the current state of knowledge on the association between selenium and colorectal cancer or adenoma has revealed not only inconclusive results of the studies, but has also shown that there is a need to conduct more prospective studies.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego