169 research outputs found

    Сжигание или мелкое диспергирование створок головного обтекателя ракеты-носителя за счет дополнительного подвода тепла при движении на атмосферном участке траектории спуска

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    The aim of this study was the establishment of precision-cut lung slices (PCLS) as a suitable ex vivo alternative approach to animal experiments for investigation of immunomodulatory effects. For this purpose we characterized the changes of cytokine production and the expression of cell surface markers after incubation of PCLS with immunoactive substances lipopolysaccharide (LPS), macrophage-activating lipopeptide-2 (MALP-2), interferon ? (IFN?), and dexamethasone. Viability of PCLS from wild-type and CD11c-enhanced yellow fluorescent protein (CD11-EYFP)-transgenic mice was controlled by measurement of lactate dehydrogenase (LDH) enzyme activity and live/dead fluorescence staining using confocal microscopy. Cytokines and chemokines were detected with Luminex technology and ELISA. Antigen presenting cell (APC) markers were investigated in living mouse PCLS in situ using confocal microscopy. LPS triggered profound pro-inflammatory effects in PCLS. Dexamethasone prevented LPS-induced production of cytokines/chemokines such as interleukin (IL)-5, IL-1greek small letter alpha, TNFgreek small letter alpha, IL-12(p40), and RANTES in PCLS. Surface expression of MHC class II, CD40, and CD11c, but not CD86 was present in APCs of naive PCLS. Incubation with LPS enhanced specifically the expression of MHC class II on diverse cells. MALP-2 only failed to alter cytokine or chemokine levels, but was highly effective in combination with IFN? resulting in increased levels of TNFgreek small letter alpha, IL-12(p40), RANTES, and IL-1greek small letter alpha. PCLS showed characteristic responses to typical pro-inflammatory stimuli and may thus provide a suitable ex vivo technique to predict the immunomodulatory potency of inhaled substances

    Antiplasmodial Properties and Cytotoxicity of Endophytic Fungi from Symphonia globulifera (Clusiaceae)

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    Ateba JET, Toghueo RMK, Awantu AF, et al. Antiplasmodial Properties and Cytotoxicity of Endophytic Fungi from Symphonia globulifera (Clusiaceae). JOURNAL OF FUNGI. 2018;4(2): UNSP 70.There is continuing need for new and improved drugs to tackle malaria, which remains a major public health problem, especially in tropical and subtropical regions of the world. Natural products represent credible sources of new antiplasmodial agents for antimalarial drug development. Endophytes that widely colonize healthy tissues of plants have been shown to synthesize a great variety of secondary metabolites that might possess antiplasmodial benefits. The present study was carried out to evaluate the antiplasmodial potential of extracts from endophytic fungi isolated from Symphonia globulifera against a chloroquine-resistant strain of Plasmodium falciparum (PfINDO). Sixty-one fungal isolates with infection frequency of 67.77% were obtained from the bark of S. globulifera. Twelve selected isolates were classified into six different genera including Fusarium, Paecilomyces, Penicillium, Aspergillus, Mucor, and Bipolaris. Extracts from the 12 isolates were tested against PfINDO, and nine showed good activity (IC50 < 10 mu g.mL(-1)) with three fungi including Paecilomyces lilacinus (IC50 = 0.44 mu g.mL(-1)), Penicillium janthinellum (IC50 = 0.2 mu g.mL(-1)), and Paecilomyces sp. (IC50 = 0.55 mu g.mL(-1)) showing the highest promise. These three isolates were found to be less cytotoxic against the HEK293T cell line with selectivity indices ranging from 24.52 to 70.56. Results from this study indicate that endophytic fungi from Symphonia globulifera are promising sources of hit compounds that might be further investigated as novel drugs against malaria. The chemical investigation of active extracts is ongoing

    Antiparasitic Constituents of Beilschmiedia louisii and Beilschmiedia obscura and Some Semisynthetic Derivatives (Lauraceae)

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    Waleguele CC, Mba’ning BM, Awantu AF, et al. Antiparasitic Constituents of Beilschmiedia louisii and Beilschmiedia obscura and Some Semisynthetic Derivatives (Lauraceae). Molecules. 2020;25(12): 2862.The MeOH/CH2Cl2 (1:1) extracts of the roots and leaves of Beilschmiedia louisii and B. obscura showed potent antitrypanosomal activity during preliminary screening on Trypanosoma brucei brucei. Phytochemical investigation of these extracts led to the isolation of a mixture of two new endiandric acid derivatives beilschmiedol B (1) and beilschmiedol C (2), and one new phenylalkene obscurene A (3) together with twelve known compounds (4–15). In addition, four new derivatives (11a–11d) were synthesized from compound 11. Their structures were elucidated based on their NMR and MS data. Compounds 5, 6, and 7 were isolated for the first time from the Beilschmiedia genus. Additionally, the NMR data of compound 4 are given here for the first time. The isolates were evaluated for their antitrypanosomal and antimalarial activities against Tb brucei and the Plasmodium falciparum chloroquine-resistant strain Pf3D7 in vitro, respectively. From the tested compounds, the mixture of new compounds 1 and 2 exhibited the most potent antitrypanosomal activity in vitro with IC50 value of 4.91 μM

    Author Correction: identification of fungal lignocellulose-degrading biocatalysts secreted by Phanerochaete chrysosporium via activity-based protein profiling

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    Correction to: Communications Biology https://doi.org/10.1038/s42003-022-04141-x, published online 16 November 2022.In the original version of the Article, an incorrect additional description of panel b in Figure 1 was included. The following sentence has now been removed:b Lignocellulose is a complex and recalcitrant polymer built up from cellulose, xylan (hemicellulose), and lignin. Its degradation requires the synergistic action of various different enzymes.Bio-organic Synthesi

    Identification of fungal lignocellulose-degrading biocatalysts secreted by Phanerochaete chrysosporium via activity-based protein profiling

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    Activity-based protein profiling is used to screen lignocellulose-degrading enzymes from the white rot fungus Phanerochaete chrysosporium to identify those specifically active in the presence of wood substrate.Activity-based protein profiling (ABPP) has emerged as a versatile biochemical method for studying enzyme activity under various physiological conditions, with applications so far mainly in biomedicine. Here, we show the potential of ABPP in the discovery of biocatalysts from the thermophilic and lignocellulose-degrading white rot fungus Phanerochaete chrysosporium. By employing a comparative ABPP-based functional screen, including a direct profiling of wood substrate-bound enzymes, we identify those lignocellulose-degrading carbohydrate esterase (CE1 and CE15) and glycoside hydrolase (GH3, GH5, GH16, GH17, GH18, GH25, GH30, GH74 and GH79) enzymes specifically active in presence of the substrate. As expression of fungal enzymes remains challenging, our ABPP-mediated approach represents a preselection procedure for focusing experimental efforts on the most promising biocatalysts. Furthermore, this approach may also allow the functional annotation of domains-of-unknown functions (DUFs). The ABPP-based biocatalyst screening described here may thus allow the identification of active enzymes in a process of interest and the elucidation of novel biocatalysts that share no sequence similarity to known counterparts.Bio-organic Synthesi

    Импортозамещение межсекционных уплотнений на примере многоступенчатого насоса "Grundfos"

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    Bronchoconstriction is a characteristic symptom of various chronic obstructive respiratory diseases such as chronic obstructive pulmonary disease (COPD) and asthma. Precision-cut lung slices (PCLS) are a suitable ex vivo model to study physiological mechanisms of bronchoconstriction in different species. In the present study, we established an ex vivo model of bronchoconstriction in non-human primates (NHPs). PCLS prepared from common marmosets, cynomolgus macaques, rhesus macaques, and anubis baboons were stimulated with increasing concentrations of representative bronchoconstrictors: methacholine, histamine, serotonin, leukotriene D4 (LTD4), U46619, and endothelin-1. Alterations in the airway caliber were measured and compared to previously published data from rodents, guinea pigs, and humans. Methacholine induced maximal airway constriction, varying between 74 and 88% in all NHP species, whereas serotonin was ineffective. Histamine induced maximal bronchoconstriction of 77 to 90% in rhesus macaques, cynomolgus macaques, and baboons, and a lesser constriction of 53% in marmosets. LTD4 was ineffective in marmosets and rhesus macaques, but induced a maximum constriction of 44 to 49% in cynomolgus macaques and baboons. U46619 and endothelin-1 caused airway constriction in all NHP species, with maximum constrictions of 65 to 91%, and 70 to 81%, respectively. In conclusion, PCLS from NHPs represent a valuable ex vivo model for studying bronchoconstriction. All NHPs respond to mediators relevant to human airway disorders such as methacholine, histamine, U46619, endothelin-1 and are insensitive to the rodent mast cell product serotonin. Only PCLS from cynomolgus macaques and baboons, however, responded also to leukotrienes, suggesting that among all compared species, these two NHPs resemble the human airway mechanisms bes

    The luxS mutation causes loosely-bound biofilms in Shewanella oneidensis

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    <p>Abstract</p> <p>Background</p> <p>The <it>luxS </it>gene in <it>Shewanella oneidensis </it>was shown to encode an autoinducer-2 (AI-2)-like molecule, the postulated universal bacterial signal, but the impaired biofilm growth of a <it>luxS </it>deficient mutant could not be restored by AI-2, indicating it might not have a signalling role in this organism.</p> <p>Findings</p> <p>Here, we provide further evidence regarding the metabolic role of a <it>luxS </it>mutation in <it>S. oneidensis</it>. We constructed a <it>luxS </it>mutant and compared its phenotype to a wild type control with respect to its ability to remove AI-2 from the medium, expression of secreted proteins and biofilm formation. We show that <it>S. oneidensis </it>has a cell-dependent mechanism by which AI-2 is depleted from the medium by uptake or degradation at the end of the exponential growth phase. As AI-2 depletion is equally active in the <it>luxS </it>mutant and thus does not require AI-2 as an inducer, it appears to be an unspecific mechanism suggesting that AI-2 for <it>S. oneidensis </it>is a metabolite which is imported under nutrient limitation. Secreted proteins were studied by iTraq labelling and liquid chromatography mass spectrometry (LC-MS) detection. Differences between wild type and mutant were small. Proteins related to flagellar and twitching motility were slightly up-regulated in the <it>luxS </it>mutant, in accordance with its loose biofilm structure. An enzyme related to cysteine metabolism was also up-regulated, probably compensating for the lack of the LuxS enzyme. The <it>luxS </it>mutant developed an undifferentiated, loosely-connected biofilm which covered the glass surface more homogenously than the wild type control, which formed compact aggregates with large voids in between.</p> <p>Conclusions</p> <p>The data confirm the role of the LuxS enzyme for biofilm growth in <it>S. oneidensis </it>and make it unlikely that AI-2 has a signalling role in this organism.</p

    COL4A3 is degraded in allergic asthma and degradation predicts response to anti-IgE therapy.

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    BACKGROUND: Asthma is a heterogeneous syndrome substantiating the urgent requirement for endotype-specific biomarkers. Dysbalance of fibrosis and fibrolysis in asthmatic lung tissue leads to reduced levels of the inflammation-protective collagen 4 (COL4A3). OBJECTIVE: To delineate the degradation of COL4A3 in allergic airway inflammation and evaluate the resultant product as a biomarker for anti-IgE therapy response. METHODS: The serological COL4A3 degradation marker C4Ma3 (Nordic Bioscience, Denmark) and serum cytokines were measured in the ALLIANCE cohort (paediatric cases/controls: n=134/n=35; adult cases/controls: n=149/n=31). Exacerbation of allergic airway disease in mice was induced by sensitising to ovalbumin (OVA), challenge with OVA aerosol and instillation of poly(cytidylic-inosinic). Fulacimstat (chymase inhibitor; Bayer) was used to determine the role of mast cell chymase in COL4A3 degradation. Patients with cystic fibrosis (n=14) and cystic fibrosis with allergic bronchopulmonary aspergillosis (ABPA; n=9) as well as patients with severe allergic uncontrolled asthma (n=19) were tested for COL4A3 degradation. Omalizumab (anti-IgE) treatment was assessed using the Asthma Control Test. RESULTS: Serum levels of C4Ma3 were increased in asthma in adults and children alike and linked to a more severe, exacerbating allergic asthma phenotype. In an experimental asthma mouse model, C4Ma3 was dependent on mast cell chymase. Serum C4Ma3 was significantly elevated in cystic fibrosis plus ABPA and at baseline predicted the success of the anti-IgE therapy in allergic, uncontrolled asthmatics (diagnostic OR 31.5). CONCLUSION: C4Ma3 levels depend on lung mast cell chymase and are increased in a severe, exacerbating allergic asthma phenotype. C4Ma3 may serve as a novel biomarker to predict anti-IgE therapy response
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