Exudates
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Pomocí mikroextrakce do pevné fáze (SPME) a plynové chromatografie byly v souboru 137 mikrobiologicky positivních i negativních klinických exsudátů stanoveny profily těkavých karboxylových kyselin (VFA). Zatímco aerobní bakterie poskytovaly málo charakteristické profily s malým obsahem nižších kyselin nebo byly chromatograficky negativní, poskytovaly anaerobní bakterie profily s větším obsahem vyšších kyselin. Ve 20,4 % exsudátů umožnila tato metoda během 15 minut detekci mikrobů nenalezených kultivačním vyšetřením, pravděpodobně nesporolujících anaerobů. Jejich bližší charakterizace je touto metodou v důsledku nestandardních podmínek jejich růstu možná jen orientačně.
The volatile fatty acid (VFA) patterns were determined in 137 microbiologically positive and negative clinical exudates using solid phase microextraction (SPME) and gas chromatography. The aerobic bacteria yielded less distinctive patterns with small content of lower acids, whereas patterns of anaerobes contained larger amounts of higher acids. The method made it possible to detect within 15 minutes bacteria, probably non-sporulating anaerobes, in 20,4 % of exudates false-negative by cultivation. Only tentative characterisation of these bacteria was possible due to the poorly defined conditions of their growth.
- MeSH
- aerobní bakterie izolace a purifikace metabolismus MeSH
- anaerobní bakterie izolace a purifikace metabolismus MeSH
- chromatografie plynová využití MeSH
- exsudáty a transsudáty mikrobiologie MeSH
- finanční podpora výzkumu jako téma MeSH
- kyseliny karboxylové analýza MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- MeSH
- diferenciální diagnóza MeSH
- diskriminační analýza MeSH
- lidé MeSH
- pleurální výpotek diagnóza MeSH
- Check Tag
- lidé MeSH
- MeSH
- exsudáty a transsudáty MeSH
- lidé MeSH
- nádory plic komplikace MeSH
- zdravotnické přehledy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
- MeSH
- exsudáty a transsudáty patologie MeSH
- Check Tag
- mužské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
BACKGROUND AND AIMS: Allelopathy may drive invasions of some exotic plants, although empirical evidence for this theory remains largely inconclusive. This could be related to the large intraspecific variability of chemically mediated plant-plant interactions, which is poorly studied. This study addressed intraspecific variability in allelopathy of Heracleum mantegazzianum (giant hogweed), an invasive species with a considerable negative impact on native communities and ecosystems. METHODS: Bioassays were carried out to test the alleopathic effects of H. mantegazzianum root exudates on germination of Arabidopsis thaliana and Plantago lanceolata. Populations of H. mantegazzianum from the Czech Republic were sampled and variation in the phytotoxic effects of the exudates was partitioned between areas, populations within areas, and maternal lines. The composition of the root exudates was determined by metabolic profiling using ultra-high-performance liquid chromatography with time-of-flight mass spectrometry, and the relationships between the metabolic profiles and the effects observed in the bioassays were tested using orthogonal partial least-squares analysis. KEY RESULTS: Variance partitioning indicated that the highest variance in phytotoxic effects was within populations. The inhibition of germination observed in the bioassay for the co-occurring native species P. lanceolata could be predicted by the metabolic profiles of the root exudates of particular maternal lines. Fifteen compounds associated with this inhibition were tentatively identified. CONCLUSIONS: The results present strong evidence that intraspecific variability needs to be considered in research on allelopathy, and suggest that metabolic profiling provides an efficient tool for studying chemically mediated plant-plant interactions whenever unknown metabolites are involved.
- MeSH
- alelopatie * MeSH
- Arabidopsis účinky léků MeSH
- bolševník chemie genetika metabolismus MeSH
- druhová specificita MeSH
- ekosystém MeSH
- klíčení účinky léků MeSH
- kořeny rostlin chemie genetika metabolismus MeSH
- metabolom * MeSH
- Plantago účinky léků MeSH
- rostlinné exsudáty chemie izolace a purifikace metabolismus MeSH
- zavlečené druhy MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Here is presented some of the first information on interactions of compounds produced by cyanobacteria and green algae with estrogen receptor signaling. Estrogenic potency of aqueous extracts and exudates (culture spent media with extracellular products) of seven species of cyanobacteria (10 different laboratory strains) and two algal species were assessed by use of in vitro trans-activation assays. Compounds produced by cyanobacteria and algae, and in particular those excreted from the cells, were estrogenic. Most exudates were estrogenic with potencies expressed at 50% of the maximum response under control of the estrogen receptor ranging from 0.2 to 7.2 ng 17β-estradiol (E(2)) equivalents (EEQ)/L. The greatest estrogenic potency was observed for exudates of Microcystis aerigunosa, a common species that forms water blooms. Aqueous extracts of both green algae, but only one species of cyanobacteria (Aphanizomenon gracile) elicited significant estrogenicity with EEQ ranging from 15 to 280 ng 17β-estradiol (E(2))/g dry weight. Scenedesmus quadricauda exudates and extracts of Aphanizomenon flos-aquae were antagonistic to the ER when coexposed to E(2). The EEQ potency was not correlated with concentrations of cyanotoxins, such as microcystin and cylindrospermopsin, which suggests that the EEQ was comprised of other compounds. The study demonstrates some differences between the estrogenic potency of aqueous extracts prepared from the same species, but of different origin, while the effects of exudates were comparable within species. The observed estrogenic potencies are important namely in relation to the possible mass expansion of cyanobacteria and release of the active compounds into surrounding water.
- MeSH
- Aphanizomenon metabolismus MeSH
- biotest MeSH
- chemické látky znečišťující vodu metabolismus farmakologie MeSH
- Chlorophyta metabolismus MeSH
- endokrinní disruptory metabolismus farmakologie MeSH
- estradiol metabolismus farmakologie MeSH
- estrogeny metabolismus farmakologie MeSH
- eutrofizace MeSH
- exsudáty a transsudáty chemie MeSH
- mezibuněčná komunikace fyziologie MeSH
- Microcystis účinky léků MeSH
- receptory pro estrogeny metabolismus MeSH
- sinice metabolismus MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Root exudates comprise a large variety of compounds released by plants into the rhizosphere, including low-molecular-weight primary metabolites (particularly saccharides, amino acids and organic acids) and secondary metabolites (phenolics, flavonoids and terpenoids). Changes in exudate composition could have impacts on the plant itself, on other plants, on soil properties (e.g. amount of soil organic matter), and on soil organisms. The effects of drought on the composition of root exudates, however, have been rarely studied. We used an ecometabolomics approach to identify the compounds in the exudates of Quercus ilex (holm oak) under an experimental drought gradient and subsequent recovery. Increasing drought stress strongly affected the composition of the exudate metabolome. Plant exudates under drought consisted mainly of secondary metabolites (71% of total metabolites) associated with plant responses to drought stress, whereas the metabolite composition under recovery shifted towards a dominance of primary metabolites (81% of total metabolites). These results strongly suggested that roots exude the most abundant root metabolites. The exudates were changed irreversibly by the lack of water under extreme drought conditions, and the plants could not recover.
AIM: A new HPLC method for the determination of neopterin, kynurenine and tryptophan using a second-generation monolith stationary phase and high-throughput sample preparation procedure based on microplates was developed and fully validated. MATERIALS & METHODS: As the stationary phase a monolithic C18 Chromolith high-resolution column with dimensions of 4.6 × 100 mm connected to a monolithic 4.6 × 10-mm security guard was used. Separation was achieved using 15 mM phosphate buffer (KH2PO4 +K2HPO4·3H2O at pH 3) and acetonitrile in gradient mode. RESULTS: Target analytes were determined in 5.5 minutes in amniotic fluid, effusions and wound exudates with a limit of quantification (LOQ) of 1.25 nM for neopterin, 2.5 µM for tryptophan and 0.25 µM for kynurenine. DISCUSSION: The method was applied to real clinical sample measurements, and it will be used to monitor neopterin, kynurenine and tryptophan levels in biological fluids to assess the patient response to therapy and clinical status.
- MeSH
- exsudáty a transsudáty metabolismus MeSH
- hojení ran * MeSH
- kynurenin analýza MeSH
- lidé MeSH
- maligní pleurální výpotek metabolismus MeSH
- neopterin analýza MeSH
- plodová voda metabolismus MeSH
- spektrofotometrie ultrafialová MeSH
- tryptofan analýza MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
