38 research outputs found

    Synergistic ROS-Associated antimicrobial activity of silver nanoparticles and gentamicin against "Staphylococcus epidermidis"

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    Introduction: Increasing bacteria resistance to antibiotics is a major problem of healthcare system. There is a need for solutions that broaden the spectrum of bactericidal agents improving the efficacy of commonly used antibiotics. One of the promising directions of search are silver nanoparticles (obtained by different methods and displaying diversified physical and chemical properties), and their combination with antibiotics. Purpose: In this study, we tested the role of reactive oxygen species in the mechanism of synergistic antibacterial activity of gentamicin and Tween-stabilized silver nanoparticles against gentamicin-resistant clinical strains of Staphylococcus epidermidis. Methods: Synergistic bactericidal activity of gentamicin and silver nanoparticles stabilized with non-ionic detergent (Tween 80) was tested by the checkerboard titration method on microtiter plates. Detection of reactive oxygen species was based on the chemiluminescence of luminol. Results: Hydrophilic non-ionic surface functionalization of silver nanoparticles enabled the existence of non-aggregated active nanoparticles in a complex bacterial culture medium. Tween-stabilized silver nanoparticles in combination with gentamicin exhibited bactericidal activity against multidrug-resistant biofilm forming clinical strains of Staphylococcus epidermidis. A synergistic effect significantly decreased the minimal inhibitory concentration of gentamicin (the antibiotic with numerous undesirable effects). Gentamicin significantly enhanced the generation of reactive oxygen species by silver nanoparticles. Conclusion: Generation of reactive oxygen species by Tween-coated metallic silver nanoparticles was significantly enhanced by gentamicin, confirming the hypothesis of oxidative-associated mechanism of the synergistic antibacterial effect of the gentamicin-silver nanoparticles complex

    Interleukin 1 level, cognitive performance, and severity of depressive symptoms in patients treated with systemic anticancer therapy: a prospective study

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    Aim To assess the relationship between cognitive functions, severity of depressive symptoms, and expression of interleukin 1 (IL)-1 in patients treated with systemic anticancer therapy. Methods This prospective study, conducted in 2017-2018, involved 55 patients (56% men) subjected to systemic anticancer therapy. Forty-one patients had lung cancer (74.55%) and 14 had breast cancer (25.45%). Patients’ mean age was 55.5 ± 9.3 (from 26 to 65 years). Neuropsychological tests were conducted twice: on the day of qualifying for the study before the start of chemotherapy and after the end of the full treatment cycle. We assessed patients’ cognitive functioning using Trail Making Test A&B (TMT), Stroop Color-Word Interference Test, and Verbal Fluency Test (VFT). Severity of depressive symptoms and the level of IL-1 expression were also examined.Results After chemotherapy, patients had significantly lower expression of IL-1α (P < 0.005) and IL-1β (P < 0.001) at the protein level. They also had lower severity of depressive symptoms (borderline significant, P = 0.063), needed more time to complete the first part of the Stroop test (P = 0.03), and had worse score on the first part of the VFT (P < 0.001). Before chemotherapy there was a significant negative correlation between IL-1β expression and the speed at which the first part of the TMT test was completed. Conclusions The severity of depressive symptoms after chemotherapy was lower than before chemotherapy. Patients’ cognitive performance did not significantly deteriorate after chemotherapy, except the performance at the first part of the Stroop test and the first part of the VFT

    Pułapki (nie)dostępności – muzeum w dobie nowoczesnych technologii. Na przykładzie Muzeum Narodowego w Krakowie

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    Muzeum pełni ważną rolę edukacyjną, dostarczając wiedzy i informacji w trakcie zwiedzania kolekcji muzealnych. Stanowi również przestrzeń dla spotkań ludzi, którzy mając podobne zainteresowania przyczyniają się do budowania sieci społecznych i kapitału kulturowego. Dziś muzeum, jak każda instytucja, stanęła wobec nowych wyzwań w obliczu pojawienia się nowoczesnych technologii, które z jednej strony otwierają się na osoby z różnymi rodzajami niepełnosprawności, a z drugiej stanowią nowy powód wykluczenia tych, dla których te technologie nie są dostępne. Przepisy prawa narzuciły podmiotom publicznym konieczność dostosowania rozwiązań cyfrowych do standardów dostępności dla osób z niepełnosprawnościami. To sprawia, że dziś w ofercie muzealnej coraz częściej możemy zobaczyć wirtualne kolekcje i/lub inne nowoczesne rozwiązania opracowane na podstawie współczesnych technologii, ułatwiające zwiedzanie. Nasz artykuł pokazuje, jak osoby z niepełnosprawnościami oceniają rozwiązania wprowadzone w Muzeum Książąt Czartoryskich w Krakowie, ułatwiające dostępność kolekcji. Przeprowadzone wywiady pozwoliły ocenić, jakie działania ze strony muzeum są najbardziej cenione przez badane osoby z niepełnosprawnościami, skąd czerpią wiedzę na temat kolekcji oraz jaki potencjał widzą w nowych technologiach.The museum plays an important educational role, providing knowledge and information while visiting museum collections. It is also a meeting space for people who have similar interests, contributing to building their networks and cultural capital. Today, the museum, like every cultural institution, has faced new challenges in the face of the emergence of modern technologies, which on the one hand open the museum to people with various types of disabilities, and on the other, constitute a new reason for excluding those for whom these technologies are not available. The law has imposed on public entities, including the museum, the need to adapt digital solutions to the standards of accessibility for people with disabilities. This means that today the museum offer more often includes virtual tours or solutions based on modern technologies that facilitate sightseeing. Our article shows how people with disabilities evaluate the solutions that facilitate accessibility introduced at the Princes Czartoryski Museum in Krakow. The interviews allowed to recreate the activities of the museum are most appreciated by the respondents with disabilities, from where they learn about the collection and what potential they see in new technologies used in museums to advertise events and / or share the collection

    Assessment of measurement reliability for the IPN test in cardiac patients

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    Cardiological diagnostics use maximal and submaximal tests with increasing load. Maximal stress tests are currently considered the gold standard. The Institut für Prävention und Nachsorge, Cologne (IPN) test may be an alternative when maximal patient load is not indicated. The universality of the test is well-documented in sport, but the reliability of this test is unknown. The aim of this study was to assess between-trial and between-day reliability for parameters assessed by the IPN stress test in cardiological patients.: In a study of 24 patients aged 39 to 79 years with cardiovascular diseases, the IPN cycle ergometer short test was performed (submaximal performance test). The reliability of heart rate, systolic and diastolic pressure, absolute power at submaximal load, relative performance at submaximal load and target heart rate were assessed. Good (Interclass Correlation Coefficient (ICC) values ranged from 0.832 to 0.894) and excellent (ICC values ranged from 0.904 to 0.969) between-trial reliability was noted. Between-day reliability was good (ICC values from 0.777 to 0.895) and excellent (ICC values from 0.922 to 0.950). The obtained results suggest that the IPN test may be a reliable tool for use in the assessment of cardiological patients, avoiding the implementation of maximal efforts when excessive patient load is not recommended

    PCR-RFLP detection of point mutations A2143G and A2142G in 23S rRNA gene conferring resistance to clarithromycin in Helicobacter pylori strains

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    Background. The occurrence of clarithromycin resistance among Helicobacter pylori strains is a major cause of the treatment failure. Resistance to this drug is conferred by point mutations in 23S rRNA gene and the most prevalent mutations are A2143G and A2142G. The aim of the study was to evaluate the occurrence of A2143G and A2142G mutations in a group of H. pylori strains resistant to clarithromycin. Materials and Methods. The study included 21 clarithromycin-resistant H. pylori strains collected between 2006 and 2009 in southern Poland. Resistance to clarithromycin was quantitatively tested with the E-test to determine the minimal inhibitory concentration (MIC value). The point mutations of H. pylori isolates were detected by PCR followed by RFLP analysis. Results. The MIC values for clarithromycin for the analyzed strains ranged from 1.5 mg/L to 64 mg/L. Nine H. pylori strains exhibited A2143G mutation and A2142G mutation was found in 9 isolates as well. The results of RFLP analysis of 3 clarithromycin-resistant strains were negative for both mutations. The average MIC values for A2143G and A2142G mutants were 6 and 30 mg/L, respectively. Conclusions. Frequencies of A2143G and A2142G mutations were the same in all isolates tested. Strains with A2143G mutation exhibited lower MIC values than A2142G mutants. Application of PCR-RFLP method for detection of clarithromycin resistance allows for better and more efficient management of H. pylori infections

    Variability in Prevalence of Helicobacter pylori Strains Resistant to Clarithromycin and Levofloxacin in Southern Poland

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    Background. An increasing resistance of Helicobacter pylori strains to antimicrobial agents is the serious therapeutic problem. The aim of this study was to compare the primary and secondary resistance of H. pylori strains isolated between 2006–2008 (data published) and 2009–2011 to clarithromycin and levofloxacin. Material and Methods. 220 dyspeptic patients (153 before treatment, 67 after), were enrolled in the study. 51 H. pylori strains were isolated. MIC values of clarithromycin and levofloxacin were determined by the E-test method. The statistical analysis was conducted with the χ2 test with Yates correction at the 0.05 significance level (P ≤ 0.05). Results. Between 2006 and 2008, 34% (39/115) of H. pylori strains were resistant to clarithromycin (primary 21% (19/90), secondary 80% (20/25)). 5% (6/115) of strains were resistant to levofloxacin (primary 2% (2/90), secondary 16% ((4/25); data published) Between 2009–2011, 22% (11/51) of H. pylori strains were resistant to clarithromycin (primary 19% (8/43), secondary 38% (3/8)). 16% (8/51) of strains were resistant to levofloxacin (primary 12% (5/43), secondary 38% (3/8)). Conclusion. The present study has shown the increasing amount of resistant H. pylori strains isolated from patients in Southern Poland to levofloxacin and decreasing number of resistant strains to clarithromycin

    Levofloxacin resistance of "Helicobacter pylori" strains isolated from patients in Southern Poland between 2006-2012

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    An increasing resistance of Helicobacter pylori (H. pylori) to antimicrobial agents leads to the need of regional monitoring of the prevalence resistant strains (according to the Maastricht/Florence consensus report, 2012). The aim of the study was to assess the resistance to levofloxacin of H. pylori strains isolated from adult patients of Ma≥opolska region in Poland. Bioptates taken from gastric mucosa during gastroscopy constituted the material for the study. Two hundred ten H. pylori strains were isolated from 811 patients. A majority of strains (171) came from patients before the treatment of H. pylori infections while the remaining 39 strains were isolated from patients after the failed therapy. Susceptibility of H. pylori to levofloxacin was determined by strips impregnated with antibiotic gradient (E-test, bioMerieux). The obtained minimum inhibitory concentration (MIC) values ranged from 0.002 mg/L to 32 mg/L. The percentage of strains resistant to levofloxacin amounted to 8.10% (17/210). Among the group of strains isolated from patients before the treatment, 5.85% (10/171) of H. pylori strains were resistant to levofloxacin. In the group of strains isolated from patients after the treatment 17.95% (7/39) of strains were resistant. The difference in the frequency of H. pylori strains resistant to levofloxacin in patients before and after the treatment of the infection due to H. pylori was statistically significant (p = 0.0297). The low percentage of H. pylori strains resistant to levofloxacin justify that the introduction of a triple therapy with levofloxacin is a good alternative in the treatment of H. pylori infections, especially in regions with high prevalence of H. pylori strains resistant to clarithromycin (> 20%)

    Evaluation of rhodamine b photocatalytic degradation over batio3-mno2 ceramic materials

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    This research was funded by UIDB/50006/2020 with funding from FCT/MCTES through national funds and from the Institute of General and Ecological Chemistry of Lodz University of Technology. Susana L.H. Rebelo and Iwona Kuźniarska-Biernacka thank FCT (Fundação para a Ciência e Tecnologia) for funding through program DL 57/2016–Norma transitória (RE-QUIMTE/EEC2018/30 (SLHR) and REQUIMTE/EEC2018/14 (IKB)).Ferroelectric ceramics (BaTiO3_MnO2 ) with different Mn admixtures were prepared using solid-state synthesis. Elemental analysis, powder X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and impedance spectroscopy confirmed that the BaTiO3 and MnO2 coexisted in the ceramics. In addition, the high purity and homogeneity of the element distributions in the ceramic samples were confirmed. The adsorptive and photocatalytic properties of the BaTiO3 (reference sample, BTO) and BaTiO3_MnO2 materials (BTO_x, where x is wt.% of MnO2 and x = 1, 2 or 3, denoted as BTO_1, BTO_2 and BTO_3, respectively) were evaluated using Rhodamine B (RhB) as the model dye in a photocatalytic chamber equipped with a UV lamp (15 W) in the absence of additional oxidants and (co)catalysts. No adsorption of RhB dye was found for all the materials during 360 min (dark experiment). All samples were photocatalytically active, and the best results were observed for the BTO_3 material, where RhB was 70% removed from aqueous solution during 360 min of irradiation. The photodegradation of RhB in the presence of MnO2-modified BTO ceramics followed a pseudo-first order model and the rate constant of BTO_3 was about 10 times higher than that of BTO, 2 times that of BTO_2, and 1.5 times that of BTO_1. The photocatalysts could be successfully reused after thermal activation. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Published under the CC BY 4.0 license.Fundação para a Ciência e Tecnologia RE-QUIMTE/EEC2018/30, REQUIMTE/EEC2018/14; Institute of General and Ecological Chemistry of Lodz University of Technology; Ministério da Ciência, Tecnologia e Ensino Superior; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2
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