This publication presents the preparation of a certi-fied methodology for in vitrotransdermal absorption test-ing of chemicals and highlights the various pitfalls in their implementation. Vertical diffusion cells (Franz cells) were used to test the dermal absorption of caffeine, benzoic acid, and testosterone across a penetration membrane (porcine ear skin), while the receptor fluid samples were evaluated by HPLC. The designed methodology was certi-fied in 2022 in the Good Laboratory Practice system and will be used at the VUOS Rybitví and at the Medical Faculty of the Charles University in Hradec Králové to assess the dermal absorption of various substances in the environment and occupational surroundings.

• MeSH
• hodnocení rizik metody   MeSH
• kofein analýza   metabolismus   MeSH
• kožní absorpce * účinky léků   MeSH
• kyselina benzoová analýza   metabolismus   MeSH
• techniky in vitro metody   přístrojové vybavení   MeSH
• testosteron analýza   metabolismus   MeSH
• výzkumný projekt MeSH
• Publikační typ
• práce podpořená grantem MeSH

The study is focused on optimization and validation of methods for determination of toxic indoxyl sulfate in human urine and blood serum. Samples were analyzed using HPLC/ED-DAD system after the biological matrix had been pretreated. Validated methods were successfully tested on samples from healthy people as well as from dialyzed patients. The aim was to monitor both indoxyl sulfate levels and impact of various methods for elimination of this toxin from patients with renal disease.

Indoxyl sulfate has been identified as a major factor in the dysregulation of several genes. It is classified as a poorly dialyzable uremic toxin and thus a leading cause in the poor survival rate of dialysis patients. A monocentric, prospective, open cohort study was performed in 43 male patients undergoing chronic renal replacement therapy in a single hemodialysis center. The aim of the study was to determine the influence of acetate- versus citrate-buffered dialysis fluids in hemodialysis (HD) and postdilution hemodiafiltration (HDF) settings on the elimination of indoxyl sulfate. Also, additional factors potentially influencing the serum concentration of indoxyl sulfate were evaluated. For this purpose, the predialysis and postdialysis concentration ratio of indoxyl sulfate and total protein was determined. The difference was of 1.15 (0.61; 2.10), 0.89 (0.53; 1.66), 0.32 (0.07; 0.63), and 0.44 (0.27; 0.77) μmol/g in acetate HD and HDF and citrate HD and HDF, respectively. Acetate HD and HDF were superior when concerning IS elimination when compared to citrate HD and HDF. Moreover, residual diuresis was determined as the only predictor of lower indoxyl sulfate concentration, suggesting that it should be preserved as long as possible. This trial is registered with EU PAS Register of Studies EUPAS23714.

• MeSH
• acetáty farmakologie   MeSH
• dialýza ledvin metody   MeSH
• dialyzační roztoky chemie   farmakologie   MeSH
• hemodiafiltrace metody   MeSH
• hydrogenuhličitany MeSH
• indican krev   farmakokinetika   MeSH
• kyselina citronová krev   farmakologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nemoci ledvin terapie   MeSH
• prospektivní studie MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky MeSH