19 research outputs found

    Study of antioxidant and antimicrobial properties of grapevine seeds, grape and rosehip pressing

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    In our experiment, we studied the antimicrobial and antioxidative effect of phytogenic additives. Three additives (grapevine seeds, grape and rosehip pressings) were selected to be monitored. The extracts about concentrations of 1:3 and 1:5 were prepared from them. The monitoring of antimicrobial properties was focused on the pathogenic bacteria Clostridium perfringens and Escherichia coli causing a serious disease in avian species. The bacteria were prepared in the dilutions of 102, 104 and 106. The antimicrobial effect was observed in the inhibition zones. The antioxidant activity was determined using DPPH method within the antioxidant analysis. Furthermore, the content of flavanols, hydroxycinnamic acids and the total content of polyphenolic compounds was also determined. In the monitoring of the antimicrobial effect of grapevine seeds, grape and rosehip pressings at E. coli, a reduced growth of KTJ (colony forming units) was observed in the disk area during the dilution of 106 and 104. Reduced growth of C. perfringens at a dilution of 106 was noticed using the extracts of grapevine seeds and grape pressings. Low reduced growth of C. perfringens at a dilution of 106 was found out using rosehip pressings. In a dilution of 102 and 104 in C. perfringens and 102 in E. Coli, a very low increase of KTJ was observed therefore the zones of inhibition were not possible to measure. In all monitored additives, the antimicrobial effect was proved. The additives reduced the growth of pathogenic E. coli and C. perfringens. Within the antioxidant analysis, the highest antioxidant activity was found out in grapevine seeds (7.021 g.L-1 GAE), which also contained the highest content of flavanols (3000 times higher than the rosehip pressings and 300 times higher than grapevine seeds pressings), hydroxycinnamic acids (1000 times higher than in grape pressings and 7600 times higher than in rosehip pressings) and the total content of polyphenolic compounds (580 times higher than grape pressings and 2000 times higher than the rosehip pressings) of the monitored additives

    Electrochemical, Biological, and Technological Properties of Anodized Titanium for Color Coded Implants

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    Anodization coloring of titanium tools or implants is one of the common methods for the differentiation of each application by its size or type. Commercial purity titanium grade 4 plates (50 × 20 × 0.1 mm) were tested to obtain their electrochemical and other technological properties. The coloring process was done using the potential of 15, 30, 45, 60, and 75 Volts for 5 s in 1 wt. % citric acid in demineralized water solution. Organic acids solutions generally produce better surface quality compared to inorganic acids. The contact angle of colored surfaces was measured by the sessile drop method. Electrochemical impedance spectroscopy and potentiodynamic polarization were used for the determination of selected electrochemical and corrosion parameters of the tested surfaces. It was found that the anodization process decreases corrosion potential significantly. It was also confirmed that a higher potential used for anodization results in higher polarization resistance but also a decrease in corrosion potential. The anodization process at 75 V produces surfaces with the lowest corrosion rate under 1 nm/year and the noblest corrosion potential. It was confirmed that the anodization process in citric acid does not affect titanium cytotoxicity

    Effect of chamomile supplements to feeding doses on antimicrobial parameters in poultry

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    Due to a ban of use of antibiotic growth promoters in the poultry industry it is necessary to look for alternative solutions. The use of some herbs showing antimicrobial effects can be one of such alternatives. In this experiment, effects of three different concentrations of chamomile (Matricaria chamomilla) extract, (0.3%; 0.6% and 1.2%) in feeding doses on the microbial population in the gastrointestinal tract of growing broiler chickens were studied. The main attention was paid to the population of Clostridium perfringens and to numbers of coliform microbes. Clostridia were cultivated under anaerobic conditions at 46 &deg;C on the Tryptone Sulfite Neomycin (TSN) agar for a period of 24 hours. Coliform microbes were grown on the violet red bile lactose (VRBL) agar at 37 &deg;C for a period of 24 hours. The experiment lasted 39 days and involved 80 chicks that were slaughtered in the course of their growth period at the age of 18, 25, 32 and 39 days; there were 5 chicks in each group. The obtained results indicated that increasing doses of chamomile in the feeding ration decreased numbers of coliform microbes in the digestive tract of chicks and also reduced the population of C. perfingens.<br /

    Komplexní mechanismus cytotoxicity svazků anodických samo-organizovaných TiO2 nanotrubic

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    The present study reports on a comprehensive investigation of mechanisms of in vitro cytotoxicity of high aspect ratio (HAR) bundles formed from anodic TiO2 nanotube (TNT) layers. Comparative cytotoxicity studies were performed using two types of HAR TNTs (diameter of similar to 110 nm), differing in initial thickness of the nanotubular layer (similar to 35 mu m for TNTs-1 vs. similar to 10 mu m for TNTs-2). Using two types of epithelial cell lines (MDA-MB-231, HEK-293), it was found that nanotoxicity is highly cell-type dependent and plausibly associates with higher membrane fluidity and decreased rigidity of cancer cells enabling penetration of TNTs to the cell membrane towards disruption of membrane integrity and reorganization of cytoskeletal network. Upon penetration, TNTs dysregulated redox homeostasis followed by DNA fragmentation and apoptotic/necrotic cell death. Both TNTs exhibited haemolytic activity and rapidly activated polarization of RAW 264.7 macrophages. Throughout the whole study, TNTs-2 possessing a lower aspect ratio manifested significantly higher cytotoxic effects. Taken together, this is the first report comprehensively investigating the mechanisms underlying the nanotoxicity of bundles formed from self-organised 1-D anodic TNT layers. Except for description of nanotoxicity of industrially-interesting nanomaterials, the delineation of the nanotoxicity paradigm in cancer cells could serve as solid basis for future efforts in rational engineering of TNTs towards selective anticancer nanomedicine.Tato studie představuje komplexní výzkum mechanizmu in vitro cytotoxicity svazků anodických vrstev TiO2 nanotrubic (TNT). Komparativní studie byly realizována s dvěma typy svazků se stejným nominálním průreme trubic (cca 110 nm), ale rozdílnou tloušťkou původních vrstev trubic: 35 mikrometrů pro TNTs-1 a 10 mikrometrů pro TNTs-2. S využitím dvou buněčných linií (MDA-MB-231, HEK-293) bylo zjištěno, že nanotoxicita je velmi závislá na použité bunečné linii a je pravděpodobně závislá od difuzních vlastností rakovinových buněčných membrán. Svazkům TNT je umožněno penetrovat tyto membrány směrem k porušení jejich celistvosti a reorganizaci cytoskeletálních sítí. Oba typy TNT svazků vykazují hemolytickou aktivitu a rapidně aktivují polarizaci RAW 264.7 makrofágů. V celé studii vykazovali svazky TNTs-2, které mají nižší poměr délky trubic vůči jejich průměru, o něco vyšší cytotoxický efekt. Toto je první report, který se uceleně zabývá mechanismem nanotoxicity svazků nanotrubic TiO2. Kromě popisu toxicity těchto aplikačně velmi zajímavých nanomateriálů, náčrt paradigmat toxicity rakovinových buněk by mohl sloužit jako pevná základna pro další optimalizaci využití TNT vrstev pro selektivní protirakovinovou nanomedicínu

    Mapping General Anesthetic Binding Site(s) in Human α1β3 γ-Aminobutyric Acid Type A Receptors with [<sup>3</sup>H]TDBzl-Etomidate, a Photoreactive Etomidate Analogue

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    The γ-aminobutyric acid type A receptor (GABA<sub>A</sub>R) is a target for general anesthetics of diverse chemical structures, which act as positive allosteric modulators at clinical doses. Previously, in a heterogeneous mixture of GABA<sub>A</sub>Rs purified from bovine brain, [<sup>3</sup>H]­azietomidate photolabeling of αMet-236 and βMet-286 in the αM1 and βM3 transmembrane helices identified an etomidate binding site in the GABA<sub>A</sub>R transmembrane domain at the interface between the β and α subunits [Li, G. D., et.al. (2006) <i>J. Neurosci. 26</i>, 11599–11605]. To further define GABA<sub>A</sub>R etomidate binding sites, we now use [<sup>3</sup>H]­TDBzl-etomidate, an aryl diazirine with broader amino acid side chain reactivity than azietomidate, to photolabel purified human FLAG-α1β3 GABA<sub>A</sub>Rs and more extensively identify photolabeled GABA<sub>A</sub>R amino acids. [<sup>3</sup>H]­TDBzl-etomidate photolabeled in an etomidate-inhibitable manner β3Val-290, in the β3M3 transmembrane helix, as well as α1Met-236 in α1M1, a residue photolabeled by [<sup>3</sup>H]­azietomidate, while no photolabeling of amino acids in the αM2 and βM2 helices that also border the etomidate binding site was detected. The location of these photolabeled amino acids in GABA<sub>A</sub>R homology models derived from the recently determined structures of prokaryote (GLIC) or invertebrate (GluCl) homologues and the results of computational docking studies predict the orientation of [<sup>3</sup>H]­TDBzl-etomidate bound in that site and the other amino acids contributing to this GABA<sub>A</sub>R intersubunit etomidate binding site. Etomidate-inhibitable photolabeling of β3Met-227 in βM1 by [<sup>3</sup>H]­TDBzl-etomidate and [<sup>3</sup>H]­azietomidate also provides evidence of a homologous etomidate binding site at the β3−β3 subunit interface in the α1β3 GABA<sub>A</sub>R

    A Simple RNA Target Capture NGS Strategy for Fusion Genes Assessment in the Diagnostics of Pediatric B-cell Acute Lymphoblastic Leukemia

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    Acute lymphoblastic leukemia (ALL) is the most frequent pediatric cancer. Fusion genes are hallmarks of ALL, and they are used as biomarkers for risk stratification as well as targets for precision medicine. Hence, clinical diagnostics pursues broad and comprehensive strategies for accurate discovery of fusion genes. Currently, the gold standard methodologies for fusion gene detection are fluorescence in situ hybridization and polymerase chain reaction; these, however, lack sensitivity for the identification of new fusion genes and breakpoints. In this study, we implemented a simple operating procedure (OP) for detecting fusion genes. The OP employs RNA CaptureSeq, a versatile and effortless next-generation sequencing assay, and an in-house as well as a purpose-built bioinformatics pipeline for the subsequent data analysis. The OP was evaluated on a cohort of 89 B-cell precursor ALL (BCP-ALL) pediatric samples annotated as negative for fusion genes by the standard techniques. The OP confirmed 51 samples as negative for fusion genes, and, more importantly, it identified known (KMT2A rearrangements) as well as new fusion events (JAK2 rearrangements) in the remaining 38 investigated samples, of which 16 fusion genes had prognostic significance. Herein, we describe the OP and its deployment into routine ALL diagnostics, which will allow substantial improvements in both patient risk stratification and precision medicine
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