Diffusive gradients in thin-films (DGT) is an in situ passive sampling technique to assess labile trace metal concentrations in different environmental matrix. The technique is consisting of a diffusive domain backed up by a resin gel that binds free metals and metal complexes that dissociate in the diffusive domain. This technique requires specific resin for special metals, for example mercury (Hg), since the classic resin (Chelex-100) gel is not applicable for Hg measurement. A simultaneous determination of Hg with other metals by the DGT was not yet reported. Two biomolecule-based resins were prepared by glutaraldehyde immobilisation of cysteine onto 3-amino-functionalised silica and 3-aminopropyl-functionalised silica, respectively. The load of functional groups on modified resins was qualitatively and quantitatively characterised. The modified resins were applied in the DGT technique and the uptake efficiency, elution efficiency, and linear accumulation of analytes of the DGT were tested. This novel DGT technique, using two cysteine-modified resins, can accumulate Hg and other metals in a broad range of pH and ionic strength in solutions. In the Belgian coastal zone (BCZ), the concentrations of Hg and other trace metals sampled by cysteine-modified resin-DGTs were similar as those by the other two DGT assemblies for Hg and other trace metals, respectively. The cysteine-modified silica resin combined the features of Chelex-100 resin and 3-mercaptopropyl silica resin and allowed simultaneous determination of labile Hg and other trace metals. The resin with a higher load of functional groups also showed higher performance in the further application in the DGT technique.
A highly porous scaffold is a desirable outcome in the field of tissue engineering. The porous structure mediates water-retaining properties that ensure good nutrient transportation as well as creates a suitable environment for cells. In this study, porous antibacterial collagenous scaffolds containing chitosan and selenium nanoparticles (SeNPs) as antibacterial agents were studied. The addition of antibacterial agents increased the application potential of the material for infected and chronic wounds. The morphology, swelling, biodegradation, and antibacterial activity of collagen-based scaffolds were characterized systematically to investigate the overall impact of the antibacterial additives. The additives visibly influenced the morphology, water‑retaining properties as well as the stability of the materials in the presence of collagenase enzymes. Even at concentrations as low as 5 ppm of SeNPs, modified polymeric scaffolds showed considerable inhibition activity towards Gram-positive bacterial strains such as Staphylococcus aureus and methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis in a dose-dependent manner.
- Publikační typ
- časopisecké články MeSH
Fish sauce is a popular seasoning liquid originating from southeastern Asian cuisine, consisting of fermented fish, salt and additional ingredients. Fish can contain high amounts of metals, some of which are hazardous for human health. Therefore, authorities responsible for food safety and quality should monitor the levels of these contaminants in fish and fish deviated products. In this work, the passive sampling technique of Diffusive Gradients in Thin-films (DGT) containing Chelex-100 and Purolite S924 resin gels, is used for the determination of dissolved mercury (Hg), cadmium (Cd) and lead (Pb) in fish sauce. The DGT performance test showed linear accumulation of Hg, Cd and Pb on the binding gels versus deployment time. A wide range of pH and salt concentration did not affect the performance of the DGT. The effective diffusion coefficients of Hg, Cd and Pb in diffusive gels were determined by applying a series of deployments in fish sauce solution. Besides the direct sampling with the DGT technique, fish sauce samples were also digested using a microwave oven. Analyses of DGT and microwave oven digested samples were performed with Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS). Both methods were then used for the analysis of fish sauces from local retail stores. Due to the preconcentration ability of DGT, lower detection limits of Hg, Cd and Pb could be achieved compared to the microwave digestion method. The DGT technique offers a more sensitive method for trace element analysis in complex food matrices.
- Publikační typ
- časopisecké články MeSH
Gadolinium (Gd)-based contrast agents are extensively used for magnetic resonance imaging (MRI). Liposomes are potential nanocarrier-based biocompatible platforms for development of new generations of MRI diagnostics. Liposomes with Gd-complexes (Gd-lip) co-encapsulated with thrombolytic agents can serve both for imaging and treatment of various pathological states including stroke. In this study, we evaluated nanosafety of Gd-lip containing PE-DTPA chelating Gd+3 prepared by lipid film hydration method. We detected no cytotoxicity of Gd-lip in human liver cells including cancer HepG2, progenitor (non-differentiated) HepaRG, and differentiated HepaRG cells. Furthermore, no potential side effects of Gd-lip were found using a complex system including general biomarkers of toxicity, such as induction of early response genes, oxidative, heat shock and endoplasmic reticulum stress, DNA damage responses, induction of xenobiotic metabolizing enzymes, and changes in sphingolipid metabolism in differentiated HepaRG. Moreover, Gd-lip did not show pro-inflammatory effects, as assessed in an assay based on activation of inflammasome NLRP3 in a model of human macrophages, and release of eicosanoids from HepaRG cells. In conclusion, this in vitro study indicates potential in vivo safety of Gd-lip with respect to hepatotoxicity and immunopathology caused by inflammation.
- MeSH
- diethylentriaminpentaacetát gadolinia * škodlivé účinky toxicita MeSH
- fibrinolytika MeSH
- fosfatidylethanolaminy * škodlivé účinky toxicita MeSH
- hepatocyty účinky léků MeSH
- inflamasomy MeSH
- kontrastní látky * MeSH
- kultivované buňky MeSH
- lidé MeSH
- liposomy * MeSH
- magnetická rezonanční tomografie * MeSH
- makrofágy účinky léků MeSH
- nanočástice MeSH
- nosiče léků * MeSH
- protein NLRP3 MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The distribution of mercury in surface water and in sediment from Deûle River in Northern France was studied by application of conventional sampling methods and by diffusive gradients in thin films technique (DGT). Concentration of total dissolved mercury in surface water was 20.8 ± 0.8 ng l(-1). The particulate mercury concentration was 6.2 ± 0.6 µg g(-1). The particulate mercury was accumulated in sediment (9.9 ± 2.3 mg kg(-1)), and it was transformed by methylating bacteria to methylmercury, mainly in the first 2-cm layer of the sediment. Total dissolved concentration of mercury in sediment pore water obtained by application of centrifugation extraction was 17.6 ± 4.1 ng l(-1), and it was comparable with total dissolved pore water mercury concentration measured by DGT probe containing Duolite GT-73 resin gel (18.2 ± 4.3 ng l(-1)), taking the sediment heterogeneity and different principles of the applied methods into account. By application of two DGT probes with different resin gels specific for mercury, it was found that approximately 30% of total dissolved mercury in sediment pore water was present in labile forms easy available for biota. The resolution of mercury DGT depth profiles was 0.5 cm, which allows, unlike conventional techniques, to study the connection of the geochemical cycle of mercury with geochemical cycles of iron and manganese.
- MeSH
- chemické látky znečišťující vodu analýza MeSH
- monitorování životního prostředí metody MeSH
- rtuť analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Francie MeSH
Tuberkulom mozku patří v České republice mezi raritní příčiny intrakraniálních expanzí. Jedná se častěji o mnohočetné ložiskové postižení mozku v rámci postprimární formy tuberkulózy. Definitivní diagnózu lze stanovit histopatologickým a/nebo bakteriologickým vyšetřením, pravděpodobnou diagnózu pak zlepšováním klinického stavu a regresí ložisek po nasazení kauzální léčby antituberkulotiky. Prognóza po zahájení terapie je poměrně příznivá, mortalita je udávána pouze 10 %. Autor prezentuje 56letou pacientku s histologicky verifikovaným tuberkulomem mozku a doporučuje vždy provést biopsii mozku i u starších pacientů s obrazem izolovaného či mnohočetného „metastatického“ postižení mozku s negativním nálezem primárního extracerebrálního tumoru při komplexním onkologickém vyšetření.
Tuberculoma of the brain is among rare causes of intracranial expansions in the Czech Republic. More frequently, there is multifocal brain disease as part of the postprimary form of tuberculosis. A definitive diagnosis can be made based on histopathological and/or bacteriological examination; a probable diagnosis can be made based on improvement in the clinical condition and focal regression after commencing causal therapy with antituberculosis drugs. Following treatment initiation, the prognosis is relatively favorable; the mortality rate is reported to be only 10%. The author presents a case of a 56-year-old female patient with a histologically proved tuberculoma of the brain and recommends to always perform brain biopsy even in older patients who present with isolated or multiple "metastatic" brain disease and with a negative finding of primary extracerebral tumor on comprehensive oncological evaluation.
- MeSH
- antituberkulotika terapeutické užití MeSH
- biopsie MeSH
- histologické techniky MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční spektroskopie MeSH
- magnetická rezonanční tomografie MeSH
- mozek patologie MeSH
- tuberkulom intrakraniální * diagnóza farmakoterapie patologie MeSH
- záchvaty MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
Concentrations of Cd, Cu, Cr, Pb, Ni and Zn were monitored in the Svitava River (the Czech Republic) during April and September 2005. Total concentrations and total dissolved concentrations were obtained through regular water sampling, and the diffusive gradients in thin films technique (DGT) were used to gain information on the kinetically labile metal concentrations. Each measured concentration was compared with the corresponding average (bio)available concentration calculated from the mass of metal accumulated by the moss species Fontinalis antipyretica. The concentrations of Cd, Pb, Cr and Zn measured using DGT corresponded well with those obtained after the deployment of Fontinalis antipyretica moss bags in the Svitava River, but the concentrations of Cu and Ni did not. The calculated (bio)available Cu concentration correlated well with the total dissolved concentration of Cu, whereas no correlation was found to exist between the concentrations of Ni.
