Occurrence of archaeophytes in agrophytocoenoses – field survey in the Czech Republic

ArticleArchaeophytes are alien plants introduced to the Czech Republic before the year 1500. Their occurrence is strongly connected with agricultural production. The aim of this study was to assess the occurrence of archaeophytes in arable fields in the Czech Republic in terms of applied management systems (conventional and organic farming), crops (winter cereals, spring cereals, wide-row crops) and environmental site conditions at different altitudes. In 2006–2018, a phytocoenological survey was conducted in selected farms across the Czech Republic. Totally, 180 weed species were found, of which 48.89% were considered as archaeophytes (88 species). In view of the invasive status, 5 archaeophytes were considered as invasive, the other 83 species were regarded as naturalized. The net effects of all variables studied on the occurrence of archaeophytes were statistically significant. The majority of the variation was explained by altitude, followed by crop and type of farming. Incidence of archaeophytes increases with an increasing altitude and is also related to their affinity with environmental factors. The highest occurrence of archaeophytes was found in cereals, some species, however, occur more frequently in wide row crops. The higher occurrence of archaeophytes was observed in organically managed fields

Graphene-Based Photodynamic Therapy and Overcoming Cancer Resistance Mechanisms: A Comprehensive Review

Hanna Dilenko, Kateřina Bartoň Tománková, Lucie Válková, Barbora Hošíková, Markéta Kolaříková, Lukáš Malina, Robert Bajgar, Hana Kolářov&#x00E1Department of Biophysics, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech RepublicCorrespondence: Kateřina Bartoň Tománková, Department of Biophysics, Faculty of Medicine and Dentistry, Palacky University, Hněvotinska 3, Olomouc, 77900, Czech Republic, Tel +420 733 690 914, Email [email protected]: Photodynamic therapy (PDT) is a non-invasive therapy that has made significant progress in treating different diseases, including cancer, by utilizing new nanotechnology products such as graphene and its derivatives. Graphene-based materials have large surface area and photothermal effects thereby making them suitable candidates for PDT or photo-active drug carriers. The remarkable photophysical properties of graphene derivates facilitate the efficient generation of reactive oxygen species (ROS) upon light irradiation, which destroys cancer cells. Surface functionalization of graphene and its materials can also enhance their biocompatibility and anticancer activity. The paper delves into the distinct roles played by graphene-based materials in PDT such as photosensitizers (PS) and drug carriers while at the same time considers how these materials could be used to circumvent cancer resistance. This will provide readers with an extensive discussion of various pathways contributing to PDT inefficiency. Consequently, this comprehensive review underscores the vital roles that graphene and its derivatives may play in emerging PDT strategies for cancer treatment and other medical purposes. With a better comprehension of the current state of research and the existing challenges, the integration of graphene-based materials in PDT holds great promise for developing targeted, effective, and personalized cancer treatments.Keywords: graphene quantum dots, graphene oxide, cancer research, photosensitizers, drug deliver

High-performance liquid chromatography–tandem mass spectrometry in the identification and determination of phase I and phase II drug metabolites

Applications of tandem mass spectrometry (MS/MS) techniques coupled with high-performance liquid chromatography (HPLC) in the identification and determination of phase I and phase II drug metabolites are reviewed with an emphasis on recent papers published predominantly within the last 6 years (2002–2007) reporting the employment of atmospheric pressure ionization techniques as the most promising approach for a sensitive detection, positive identification and quantitation of metabolites in complex biological matrices. This review is devoted to in vitro and in vivo drug biotransformation in humans and animals. The first step preceding an HPLC-MS bioanalysis consists in the choice of suitable sample preparation procedures (biomatrix sampling, homogenization, internal standard addition, deproteination, centrifugation, extraction). The subsequent step is the right optimization of chromatographic conditions providing the required separation selectivity, analysis time and also good compatibility with the MS detection. This is usually not accessible without the employment of the parent drug and synthesized or isolated chemical standards of expected phase I and sometimes also phase II metabolites. The incorporation of additional detectors (photodiode-array UV, fluorescence, polarimetric and others) between the HPLC and MS instruments can result in valuable analytical information supplementing MS results. The relation among the structural changes caused by metabolic reactions and corresponding shifts in the retention behavior in reversed-phase systems is discussed as supporting information for identification of the metabolite. The first and basic step in the interpretation of mass spectra is always the molecular weight (MW) determination based on the presence of protonated molecules [M+H]+ and sometimes adducts with ammonium or alkali-metal ions, observed in the positive-ion full-scan mass spectra. The MW determination can be confirmed by the [M-H]- ion for metabolites providing a signal in negative-ion mass spectra. MS/MS is a worthy tool for further structural characterization because of the occurrence of characteristic fragment ions, either MSn analysis for studying the fragmentation patterns using trap-based analyzers or high mass accuracy measurements for elemental composition determination using time of flight based or Fourier transform mass analyzers. The correlation between typical functional groups found in phase I and phase II drug metabolites and corresponding neutral losses is generalized and illustrated for selected examples. The choice of a suitable ionization technique and polarity mode in relation to the metabolite structure is discussed as well

Influence of 'Trichobilharzia regenti' (Digenea: Schistosomatidae) on the defence activity of 'Radix lagotis' (Lymnaeidae) haemocytes

Radix lagotis is an intermediate snail host of the nasal bird schistosome Trichobilharzia regenti. Changes in defence responses in infected snails that might be related to host-parasite compatibility are not known. This study therefore aimed to characterize R. lagotis haemocyte defence mechanisms and determine the extent to which they are modulated by T. regenti. Histological observations of R. lagotis infected with T. regenti revealed that early phases of infection were accompanied by haemocyte accumulation around the developing larvae 2–36 h post exposure (p.e.) to the parasite. At later time points, 44–92 h p.e., no haemocytes were observed around T. regenti. Additionally, microtubular aggregates likely corresponding to phagocytosed ciliary plates of T. regenti miracidia were observed within haemocytes by use of transmission electron microscopy. When the infection was in the patent phase, haemocyte phagocytic activity and hydrogen peroxide production were significantly reduced in infected R. lagotis when compared to uninfected counterparts, whereas haemocyte abundance increased in infected snails. At a molecular level, protein kinase C (PKC) and extracellular-signal regulated kinase (ERK) were found to play an important role in regulating these defence reactions in R. lagotis. Moreover, haemocytes from snails with patent infection displayed lower PKC and ERK activity in cell adhesion assays when compared to those from uninfected snails, which may therefore be related to the reduced defence activities of these cells. These data provide the first integrated insight into the immunobiology of R. lagotis and demonstrate modulation of haemocyte-mediated responses in patent T. regenti infected snails. Given that immunomodulation occurs during patency, interference of snail-host defence by T. regenti might be important for the sustained production and/or release of infective cercariae

Original Article The Expression of NADPH Oxidases and Production of Reactive Oxygen Species by Human Lung Adenocarcinoma Epithelial Cell Line A549 (lung epithelial cells / reactive oxygen species / fluorometry / chemiluminescence)

Abstract. Controlled production of reactive oxygen species (ROS) by NADPH oxidases in non-phagocytic cells has recently been suggested to participate in the regulation of cellular functions. Due to the role of ROS in control of cellular functions, precise and accurate detection of ROS is of essential importance. However, various methodological approaches currently used for ROS determination vary in sensitivity, specificity, as well as in requirements for specialized equipment. In this study, human lung epithelial cell line A549 was screened for expression of NADPH oxidases NOX1, NOX2, NOX4, NOX5, DUOX1 and DUOX2 by quantitative RT-PCR. Fluorometric, colorimetric, and chemiluminometric methods were applied to determine ROS production. A549 cells were found to significantly express NOX1, NOX2, DUOX1 and DUOX2. ROS production by A549 cells was detected with fluorometric probes 2',7'-dichlorofluorescein-diacetate, dihydroethidium, and amplex red or colorimetric probe nitrobluetetrazolium. The production of ROS detected by these probes was partially reduced by NADPH oxidase inhibitor diphenyleneiodonium. The inhibitory effect of diphenyleneiodonium was the most significant regarding amplex red detection of phorbol myristate acetateactivated ROS production. In contrast to other probes, neither cytochrome c colorimetric determination nor luminol-and L-012-amplified chemiluminescence, regardless of the addition of horseradish peroxidase, exerted sufficient sensitivity to detect ROS production by A549. The results revealed differences among methods used for ROS formation measurement by human lung epithelial cell line A549 and highlighted the sensitivity of fluorometric determination for this purpose

n. sp. (Schistosomatidae, Bilharziellinae), a new nasal schistosome from Europe

Members of the genus Trichobilharzia are parasitic in visceral or nasal body parts of their avian hosts. The examination of water snails in South Bohemia revealed a schistosome infection in Radix peregra snails. The experimental infection of ducklings (Anas platyrhynchos, Cairina moschata) confirmed that a new Trichobilharzia species - T. regenti n. sp. - was found. The adults, eggs and larvae (miracidia and cercariae) of the species were morphologically characterized. The adults occupy the nasal blood vessels where they lay the eggs; the miracidia hatch from the eggs directly in the tissue and leave the host during drinking/feeding of the infected birds