"LM2015051" Dotaz Zobrazit nápovědu
Actinotignum schaalii is an emerging, opportunistic pathogen and its connection to non-infectious diseases and conditions, such as prostate or bladder cancer, or chronic inflammation has been proposed. Here, we analyzed 297 urine, ureteral and urinary catheter samples from 128 patients by Polymerase Chain Reaction followed by Denaturing Gradient Gel Electrophoresis and Sequencing (PCR-DGGE-S), and culture, and 29 of these samples also by 16S rRNA Illumina sequencing, to establish A. schaalii's prevalence in urinary tract-related samples, its relation to other bacteria, and its potential association with patients' conditions and samples' characteristics. A. schaalii-positive samples were significantly more diverse than A. schaalii negative and between-group diversity was higher than intra-group. Propionimicrobium lymphophilum, Fusobacterium nucleatum, Veillonella sp., Morganella sp., and Aerococcus sp. were significantly more often present in A. schaalii-positive samples; thus, we suggest these species are A. schaalii's concomitants, while Enterobacter and Staphylococcaceae were more often identified in A. schaalii-negative samples; therefore, we propose A. schaalii and these species are mutually exclusive. Additionally, a significantly higher A. schaalii prevalence in patients with ureter stricture associated hydronephrosis (p = 0.020) was noted. We suggest that A. schaalii could be an early polybacterial biofilm colonizer, together with concomitant species, known for pro-inflammatory features.
- Publikační typ
- časopisecké články MeSH
Because compounds accumulate through dry periods and enter aquatic systems in just a few seasonal events such as snowmelt and summer storms, surface waters in semi-arid, cold regions, such as the Canadian Prairies, are particularly vulnerable to loading of contaminant from runoff events from surfaces. This study assessed concentrations of metals and selected trace organics entering a river via surface runoff from an urban region and how these semi-arid regions with large seasonal variations in temperature might differ from more temperate regions. Selected potentially harmful elements (PHEs) including, Mn with Cr, Cu, Zn, Ba and U all exceeded guideline discharge values set by the Canadian Council of the Ministers of the Environment (CCME) by as much as 16-fold. Variation among discharges during spring, summer and winter was observed. For example, across the whole city, an estimated 6 kg of zinc was discharged in a spring storm, 36 kg in a summer storm and 17 tonnes in snowmelt. The mass of Zn discharged is similar to the annual loading estimated for Stockholm, Sweden, but in Saskatoon, Saskatchewan, Canada, the bulk of runoff was during snowmelt. The mean sum of poly- and per-fluoroalkyl substances (PFAS) in stormwater was 9.0 ng L-1, which is consistent with concentrations observed in other Canadian cities (6.5-16 ng L-1). These concentrations of PFAS are likely due to dispersed sources and orders of magnitude less than thresholds for toxicity to fish and aquatic invertebrates.
- MeSH
- chemické látky znečišťující vodu analýza MeSH
- kovy MeSH
- monitorování životního prostředí MeSH
- roční období MeSH
- teplota MeSH
- velkoměsta MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Saskatchewan MeSH
- Švédsko MeSH
- velkoměsta MeSH
Twenty juvenile individuals of brown bullhead (Ameiurus nebulosus), average weight 77 g, were fed by abiraterone acetate prodrug dissolved in olive oil via gastric probe. Dose applied was 3 mg/10 g fish weight. After feeding, they were let out into aquarium and kept there for 3 days. Aquarium water containing excreted metabolites was extracted, and sample was purified and finally analyzed by means of HPLC/MS. Expected both primary (products of hydroxylation) and secondary (products of glucuronidation and sulfatation) metabolites of abiraterone acetate were identified. The NMR measurement of one of the prevailing metabolites presumed to be one of possible hydroxy-abiraterones discovered that it is not hydroxy-abiraterone but abiraterone 16,17-epoxide. Closer analysis of MS2 and MS3 spectra revealed that one of presumed hydroxy-abiraterone acetates and also some secondary metabolites are probably 16,17-epoxides.
The rapid accumulation of sequence data and powerful protein engineering techniques providing large mutant libraries have greatly heightened interest in efficient methods for biochemical characterization of proteins. Herein is reported a continuous assay for screening of enzymatic activity. The assay is developed and tested with the model enzymes haloalkane dehalogenases and relies upon a fluorescent change of a derivative of 8-hydroxypyrene-1,3,6-trisulphonic acid due to the pH drop associated with the dehalogenation reactions. The assay is performed in a microplate format using a purified enzyme, cell-free extract or intact cells, making the analysis quick and simple. The method exhibits high sensitivity with a limit of detection of 0.06 mM. The assay is successfully validated with gas chromatography and then applied for screening of 12 haloalkane dehalogenases with the environmental pollutant bis(2-chloroethyl) ether and chemical warfare agent sulfur mustard. Six enzymes exhibited detectable activity with both substrates. The within-day variability of the assay for five replicates (n = 5) was 21%.
Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are ubiquitous and toxic contaminants. Their atmospheric deposition fluxes on the regional scale were quantified based on simultaneous sampling during 1 to 5 years at 1 to 6 background/rural sites in the Czech Republic and Austria. The samples were extracted and analysed by means of gas chromatography coupled to mass spectrometry. For all seasons and sites, total deposition fluxes for Σ15PAHs ranged 23-1100 ng m-2 d-1, while those for Σ6PCBs and Σ12OCPs ranged 64-4400 and 410-7800 pg m-2 d-1, respectively. Fluoranthene and pyrene were the main contributors to the PAH deposition fluxes, accounting on average for 19% each, while deposition fluxes of PCBs and OCPs were dominated by PCB153 (26%) and γ-hexachlorobenzene (30%), respectively. The highest deposition flux of Σ15PAHs was generally found in spring, while no seasonality was found for PCB deposition. For deposition fluxes for Σ12OCPs, no clear spatial trend was found, confirming the perception of long-lived regional pollutants. Although most OCPs and PCBs hardly partition to the particulate phase in ambient air, on average, 42% of their deposition fluxes were found on filters, confirming the perception that particle deposition is more efficient than dry gaseous deposition. Due to methodological constraints, fluxes derived from bulk deposition samplers should be understood as lower estimates, in particular with regard to those substances which in ambient aerosols mostly partition to the particulate phase.
- MeSH
- chlorované uhlovodíky analýza MeSH
- hexachlorbenzen analýza MeSH
- látky znečišťující vzduch analýza MeSH
- monitorování životního prostředí * MeSH
- pesticidy analýza MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- polychlorované bifenyly analýza MeSH
- polycyklické aromatické uhlovodíky analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Evropa MeSH
- Rakousko MeSH
Microcystins are cyclic peptide toxins with hepatotoxic and tumor-promoting properties, which are produced in significant quantities (up to tens of μg/L) in freshwater cyanobacterial water blooms. Several studies reported microcystin accumulation in fish with possible food transfer to humans. These compounds are further metabolized to cysteine and glutathione conjugates which can be present in tissues in significant concentrations. In this study, we focused on the development and evaluation of robust and highly sensitive SPE-LC-MS/MS method for the analysis of microcystin conjugates in fish tissue samples. For the first time, we demonstrate the use of isotopically labeled internal standards which are essential for accurate and precise determination of analytes in complex biotic matrices. LLOQs of respective microcystin conjugates (signal-to-noise ratio; S/N > 10, peak-to-peak method) ranged from 3.3 to 5.0 ng/g of tissue fresh weight (FW). The calibration was linear within a range of concentrations from 1 to 70 ng/mL for all analyzed conjugates. The precision and repeatability of the method were very good with recoveries in the range of 88.5-107.6% and relative standard deviations between 8.8 and 13.2% for all analytes. In the follow-up study, fully validated method was used for the determination of microcystin conjugate levels in common carp exposed to microcystin-containing cyanobacterial biomass under controlled conditions. Significant amounts of microcystin conjugates (up to 55 ng/g) were found in the tissues of fish after 7 weeks of exposure. Our method was shown to be robust, sensitive, selective, and suitable for the determination of trace levels of microcystin conjugates in fish tissues.
- MeSH
- biomasa MeSH
- chromatografie kapalinová metody MeSH
- cystein analýza MeSH
- glutathion analýza MeSH
- limita detekce MeSH
- mikrocystiny analýza chemie MeSH
- radioisotopová diluční technika MeSH
- reprodukovatelnost výsledků MeSH
- sinice chemie MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- Publikační typ
- časopisecké články MeSH
Passive samplers based on diffusive gradients in thin hydrogel films (DGT) were recently modified for sampling of polar organic compounds in water. However, since the sampling rates of the commonly used DGT design with the surface area of 3.1 cm2 are low, we propose to increase them by applying a two-sided design with a larger sampling surface area of 22.7 cm2. The sampler design consists of two sorptive hydrogel disks compressed between two diffusive hydrogel disk layers strengthened by nylon netting and held together by two stainless steel rings. Sorbent/water distribution coefficients (KSW) were determined, and the sampler was calibrated for monitoring 11 perfluoroalkyl substances and 12 pharmaceuticals and personal care products in water at laboratory conditions using a closed system with artificial flow generated by submersible pumps. A field performance test was conducted at five locations in the Morava River basin in Czech Republic. The median value of laboratory-derived sampling rates was 43 mL day-1 with extreme values of 2 mL day-1 and 90 mL day-1 for perfluorotridecanoic and perfluoroheptanoic acids, respectively. The log KSW values of tested compounds ranged from 3.18 to 5.47 L kg-1, and the estimated halftime to attain sampler-water equilibrium ranged from 2 days to more than 28 days, which is the maximum recommended exposure period, considering potential issues with the stability of hydrogel. The sampler can be used for assessment of spatial trends as well as estimation of aqueous concentration of investigated polar compounds.
- MeSH
- chemické látky znečišťující vodu analýza MeSH
- difuze MeSH
- fluorokarbony chemie MeSH
- hydrogely chemie MeSH
- kyseliny heptylové chemie MeSH
- organické látky chemie MeSH
- řeky chemie MeSH
- sefarosa chemie MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
