Chemotherapeutics are pharmaceutical compounds the occurrence of which in the environment is of growing concern because of the increase in treatments against cancer diseases. They can reach the aquatic ecosystems after passing through wastewater treatment plants without complete removal. One of the most frequently used chemotherapeutics is 5-fluorouracil which exhibits a strong cytostatic effect. In this paper, an analytical methodology was developed, validated, and applied to determine 5-fluorouracil, its precursor, 5-fluorocytosine, and its major active metabolite, 5-fluorouridine, in hospital wastewater samples. Due to the expected low concentrations after dilution and interferences present in such a complex matrix, a very selective and sensitive detection method is required. Moreover, an extraction method must be implemented prior to the determination in order to purify the sample extract and preconcentrate the target analytes at micrograms per liter concentration levels. Solid-phase extraction followed by liquid chromatography with tandem mass spectrometry was the combination of choice and all included parameters were studied. Under optimized conditions for wastewater samples analysis, recoveries from 63 to 108% were obtained, while intraday and interday relative standard deviations never exceeded 20 and 25%, respectively. Limits of detection between 61 and 620 ng/L were achieved. Finally, the optimized method was applied to samples from hospital wastewater effluents.

• MeSH
• chemické látky znečišťující vodu analýza   MeSH
• extrakce na pevné fázi MeSH
• flucytosin analýza   MeSH
• fluoruracil analýza   MeSH
• molekulární struktura MeSH
• nemocnice * MeSH
• odpadní voda chemie   MeSH
• tandemová hmotnostní spektrometrie MeSH
• uridin analogy a deriváty   analýza   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• fluoridace MeSH
• uridin analogy a deriváty   chemická syntéza   MeSH

• Publikační typ
• abstrakty MeSH

• MeSH
• fluoruracil analogy a deriváty   chemie   MeSH
• ftorafur analogy a deriváty   chemie   MeSH
• nukleosidy MeSH
• polarografie MeSH

• MeSH
• fluoruracil analogy a deriváty   chemická syntéza   MeSH
• uridin analogy a deriváty   chemická syntéza   MeSH

CDD plays a pivotal role within the pyrimidine salvage pathway. In this study, a novel, rapid method for the identification of cell lines lacking functional cytidine deaminase was developed. This innovative method utilizes immunocytochemical detection of the product of 5-fluorocytidine deamination, 5-fluorouridine in cellular RNA, enabling the identification of these cells within two hours. The approach employs an anti-bromodeoxyuridine antibody that also specifically binds to 5-fluorouridine and its subsequent detection by a fluorescently labeled antibody. Our results also revealed a strong correlation between the 5-fluorouridine/5-fluorocytidine cytotoxicity ratio and cytidine deaminase content. On the other hand, no correlation was observed between the 5-fluorouridine/5-fluorocytidine cytotoxicity ratio and deoxycytidine monophosphate deaminase content. Similarly, no correlation was observed between this ratio and equilibrative nucleoside transporters 1 or 2. Finally, concentrative nucleoside transporters 1, 2, or 3 also do not correlate with the 5-fluorouridine/5-fluorocytidine cytotoxicity ratio.

• MeSH
• buněčné linie MeSH
• cytidin analogy a deriváty   metabolismus   MeSH
• cytidindeaminasa * metabolismus   nedostatek   genetika   MeSH
• lidé MeSH
• uridin analogy a deriváty   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Numerous studies show that various genes in all kinds of organisms are transcribed discontinuously, i.e. in short bursts or pulses with periods of inactivity between them. But it remains unclear whether ribosomal DNA (rDNA), represented by multiple copies in every cell, is also expressed in such manner. In this work, we synchronized the pol I activity in the populations of tumour derived as well as normal human cells by cold block and release. Our experiments with 5-fluorouridine (FU) and BrUTP confirmed that the nucleolar transcription can be efficiently and reversibly arrested at +4°C. Then using special software for analysis of the microscopic images, we measured the intensity of transcription signal (incorporated FU) in the nucleoli at different time points after the release. We found that the ribosomal genes in the human cells are transcribed discontinuously with periods ranging from 45 min to 75 min. Our data indicate that the dynamics of rDNA transcription follows the undulating pattern, in which the bursts are alternated by periods of rare transcription events.

• MeSH
• buněčné jadérko genetika   MeSH
• epitelové buňky metabolismus   MeSH
• genetická transkripce * MeSH
• HeLa buňky MeSH
• kinetika MeSH
• lidé středního věku MeSH
• lidé MeSH
• limbus corneae cytologie   MeSH
• mrtvola MeSH
• nízká teplota MeSH
• ribozomální DNA genetika   MeSH
• ribozomy genetika   MeSH
• RNA ribozomální genetika   MeSH
• senioři MeSH
• software MeSH
• transfekce MeSH
• uridin analogy a deriváty   imunologie   metabolismus   MeSH
• uridintrifosfát analogy a deriváty   imunologie   metabolismus   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH