Elemental profiling of human semen with confirmed normozoospermia: Baseline levels for 44 elements.

BACKGROUND: As a consequence of the progressive decline in human semen quality in recent decades, modern epidemiological investigations have identified several trace elements that could be responsible for this phenomenon. However, their levels in semen have not been clearly elucidated, particularly for elements present in ultra-trace levels. METHODS: We aimed to determine the levels of 39 (ultra)trace elements and 5 macroelements in human semen samples with confirmed normozoospermia using ICP-based techniques. The research was amplified by analyzing blood samples from the same participants. RESULTS: Among the analyzed (ultra)trace elements in semen samples, Zn is the most and Tm is the least prominent. Zn levels in semen are so high that Zn should be considered as a macroelement in this matrix. The levels of Zn, Rh, Sm, Re, Ir, Tl, Na, and Ca were significantly higher in semen, while the levels of Cu, As, Rb, Gd, Sb, Tb, Tm, Lu, K, and Fe were significantly higher in blood. Correlation analysis of the levels of 44 individual elements in paired semen and blood samples revealed positive correlations between 43 of the elements, particularly for Tl and Pt. An exception was the negative correlation for Cu, which showed that its high level in semen is associated with a low level in blood and contrariwise. CONCLUSION: The reported data can be used as baseline levels/reference values for 44 elements in human semen. Furthermore, the findings of this study could be relevant for further consideration of male infertility.

Elemental Composition of Pheochromocytoma Resolved on Solid/Adrenal Tissue and Whole Blood Level.

Pheochromocytoma (PCC) is an unusual benign adrenal tumor with an unexamined status of the elements. This study delivers the first insight into the levels of microelements (Mn, Co, Cu, Zn, As, Se, Th), toxic elements (Cd, Pb, U), and macroelements (Na, K, Mg, Ca) in both adrenal tissue and whole blood samples collected from PCC patients. The results were strengthened by comparing recorded findings with the patients' healthy adrenal tissue (HAT) and with whole blood samples from the healthy individuals. PCCs had significantly higher levels of Zn, Se, Na, K, and Mg and lower levels of Mn, Co, Pb, and As than that of HATs. Compared to healthy blood samples, the patients' blood exhibited considerably higher levels of Na, K, and Ca but significantly lower levels of Mn, Cu, Zn, Se, and Mg. Females had significantly higher levels of essential Se and toxic Pb and Cd in their PCC tissue samples compared to males. PCC tissue levels of Mn and Cu were significantly elevated in smokers over levels in nonsmokers and in PCC patients with tumor sizes below 5 cm compared to PCC diameters above 5 cm. The data presented in this study provide a new insight into the pathophysiology of PCC. Thus, recorded elements should be considered as initiators/modifiers of PCC and potential inductors of malignant transformation. The findings of this research deepen scientific understanding of this rare adrenal disease, which, in turn, could highlight the pathogenesis of PCC.

Immobilization of Candida antarctica lipase B onto Purolite® MN102 and its application in solvent-free and organic media esterification.

The aim of this study was to develop simple and efficient method for immobilization of Candida antarctica lipase B onto hydrophobic anion exchange resin Purolite® MN102 and to apply immobilized catalyst for the enzymatic synthesis of two valuable esters-isoamyl acetate and L-ascorbyl oleate. At optimized conditions (1 M phosphate buffer pH = 7, 7 h at 25 °C, and 18.75 mg of offered proteins g-1 of support), immobilized lipase with hydrolytic activity of 888.4 p-nitrophenyl butyrate units g-1 was obtained. Afterwards, preparation was applied for the solvent-free synthesis of isoamyl acetate from triacetin and isoamyl alcohol. At 75 °C, 1 M of isoamyl alcohol, and 6 mg ml-1 of enzyme 100 % yield was achieved in 6 h, while at prolonged reaction times, complete conversion was enabled even at lower temperatures, lower lipase loadings, and higher substrate concentrations. After 15 consecutive reuses (60 h), activity of catalyst dropped to 50 % of its initial value and total amount of 1.31 mol (170.55 g) of ester with 1 g of biocatalyst was produced. Even higher operational stability of lipase (25 % loss of activity in 200 h) was observed in the synthesis of L-ascorbyl oleate performed in organic solvent (t-butanol). Multiple use of one batch of immobilized biocatalyst in both cases led to a significant process cost reduction and substantial increment of corresponding productivities.

Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity.

Fatty acid (FA) ascorbyl esters are recently emerging food, cosmetic, and pharmaceutical additives, which can be prepared in an eco-friendly way by using lipases as catalysts. Because they are amphiphilic molecules, which possess high free radical scavenging capacity, they can be applied as liposoluble antioxidants as well as emulsifiers and biosurfactants. In this study, the influence of a wide range of acyl donors on ester yield in lipase-catalyzed synthesis and ester antioxidant activity was examined. Among saturated acyl donors, higher yields and antioxidant activities of esters were achieved when short-chain FAs were used. Oleic acid gave the highest yield overall and its ester exhibited a high antioxidant activity. Optimization of experimental factors showed that the highest conversion (60.5%) in acetone was achieved with 5 g L(-1) of lipase, 50 mM of vitamin C, 10-fold molar excess of oleic acid, and 0.7 mL L(-1) of initial water. Obtained results showed that even short- and medium-chain ascorbyl esters could be synthesized with high yields and retained (or even exceeded) free radical scavenging capacity of l-ascorbic acid, indicating prospects of broadening their application in emulsions and liposomes.