1,721,025 research outputs found
Methyl 9-(2-Iminothiazol-3(2H)-yl)-9-oxononanoate
Full text linkMethyl 9-(2-iminothiazol-3(2H)-yl)-9-oxononanoate was synthesized through Schotten-Baumann type reaction between 2-aminothiazole and methyl 9-chloro-9-oxononanoate. The structure of the newly synthesized compound was elucidated based on H-1-NMR, C-13-NMR, DEPT, NOE, ESI-MS, FT-IR and UV-Vis spectroscopy
Effect of sugars on Chlamydia trachomatis infectivity
Full text linkBackground. Previous works suggest that sugars can have a beneficial effect on C. trachomatis (CT) survival and virulence. In this study, we investigated the effect of different sugars on CT infectivity, elucidating some of the molecular mechanisms behind CT-sugar interaction. Methods. CT infectivity was investigated on HeLa cells after 2 hour-incubation of elementary bodies (EBs) with glucose, sucrose, or mannitol solutions (0.5, 2.5, 5.0 mM). The effect of sugars on EB membrane fluidity was investigated by fluorescence anisotropy measurement, whereas the changes in lipopolysaccharide (LPS) exposure were examined by cytofluorimetric analysis. By means of a Western blot, we explored the phosphorylation state of Focal Adhesion Kinase (FAK) in HeLa cells infected with EBs pre-incubated with sugars. Results. All sugar solutions significantly increased CT infectivity on epithelial cells, acting directly on the EB structure. Sugars induced a significant increase of EB membrane fluidity, leading to changes in LPS membrane exposure. Especially after incubation with sucrose and mannitol, EBs led to a higher FAK phosphorylation, enhancing the activation of anti-apoptotic and proliferative signals in the host cells. Conclusions. Sugars can increase CT infectivity and virulence, by modulating the expression/exposure of chlamydial membrane ligands. Further in-depth studies are needed to better understand the molecular mechanisms involved
Hemiaminals from amino-azaheterocycles and chloral hydrate as synthons for the access to novel compounds with potential biological activity
No full textLactobacillus crispatus BC5 Interferes With Chlamydia trachomatis Infectivity Through Integrin Modulation in Cervical Cells.
Full text linkLactobacilli play a crucial role in maintaining the ecological equilibrium of the vaginal niche, preventing the colonization of exogenous microorganisms. Although many studies have discussed the mechanisms displayed by lactobacilli in counteracting several urogenital pathogens, a few data are available on the interaction between lactobacilli and Chlamydia trachomatis. This study aimed to elucidate the molecular bases of the interaction among vaginal lactobacilli, the sexually transmitted pathogen C. trachomatis and the epithelial cervical cells. We evaluated the in vitro activity of 15 Lactobacillus strains, belonging to different species (i.e., L. crispatus, L. gasseri, L. vaginalis), against C. trachomatis. In particular, we evaluated the capability of lactobacilli cells to interfere with C. trachomatis infection in HeLa cells, by exclusion assays. Lactobacilli significantly reduced C. trachomatis infectivity, being L. crispatus the most active species. Although a dose-dependent effect was noticed, a significant antagonistic activity was maintained even at lower doses. As other Gram-positive bacteria (i.e., Streptococcus agalactiae, Enterococcus faecalis, and Bacillus subtilis) failed to interfere with C. trachomatis infectivity, Lactobacillus activity proved to be specific. The potential mechanism of protection was investigated in Lactobacillus crispatus BC5, chosen as the model strain. The incubation of HeLa cell line with BC5 cells induced important modifications in the epithelial plasma membrane, by altering lipid composition and α5 integrin subunit exposure. When α5 integrin subunits were masked by a specific blocking antibody or ITGA5 gene expression was silenced, Chlamydia infection was significantly reduced. It follows that α5 integrin subunit is crucial for the pathogen infection process, and the anti-Chlamydia activity can be directly linked to membrane properties modifications in cervical cells. The three Gram-positive bacteria used as controls failed to modify the expression of α5β1 integrin. In conclusion, we identified a potential molecular mechanism at the basis of the protection exerted by L. crispatus BC5 against C. trachomatis, getting insights into the role of the cervico-vaginal microbiota for the woman's health
Design of α/β-hybrid peptide ligands of α4β1 integrin equipped with a linkable side chain for chemoselective biofunctionalization of microstructured materials
Full text linkArg-Gly-Asp (RGD)-binding integrins, e.g., αvβ3, αvβ1, αvβ5 integrins, are currently re-garded as privileged targets for the delivery of diagnostic and theranostic agents, especially in cancer treatment. In contrast, scarce attention has been paid so far to the diagnostic opportunities promised by integrins that recognize other peptide motifs. In particular, α4β1 integrin is involved in inflam-matory, allergic, and autoimmune diseases, therefore, it represents an interesting therapeutic target. Aiming at obtaining simple, highly stable ligands of α4β1 integrin, we designed hybrid α/β pep-tidomimetics carrying linkable side chains for the expedient functionalization of biomaterials, nano-and microparticles. We identified the prototypic ligands MPUPA-(R)-isoAsp(NHPr)-Gly-OH (12) and MPUPA-Dap(Ac)-Gly-OH (13) (MPUPA, methylphenylureaphenylacetic acid; Dap, 2,3-diamino propionic acid). Modification of 12 and 13 by introduction of flexible linkers at isoAsp or Dap gave 49 and 50, respectively, which allowed for coating with monolayers (ML) of flat zeolite crys-tals. The resulting peptide–zeolite MLs were able to capture selectively α4β1 integrin-expressing cells. In perspective, the α4β1 integrin ligands identified in this study can find applications for preparing biofunctionalized surfaces and diagnostic devices to control the progression of α4β1 integrin-correlated diseases
Coenzyme q depletion reshapes mcf-7 cells metabolism
Full text linkMitochondrial dysfunction plays a significant role in the metabolic flexibility of cancer cells. This study aimed to investigate the metabolic alterations due to Coenzyme Q depletion in MCF-7 cells. Method: The Coenzyme Q depletion was induced by competitively inhibiting with 4-nitrobenzoate the coq2 enzyme, which catalyzes one of the final reactions in the biosynthetic pathway of CoQ. The bioenergetic and metabolic characteristics of control and coenzyme Q depleted cells were investigated using polarographic and spectroscopic assays. The effect of CoQ depletion on cell growth was analyzed in different metabolic conditions. Results: we showed that cancer cells could cope from energetic and oxidative stress due to mitochondrial dysfunction by reshaping their metabolism. In CoQ depleted cells, the glycolysis was upregulated together with increased glucose consumption, overexpression of GLUT1 and GLUT3, as well as activation of pyruvate kinase (PK). Moreover, the lactate secretion rate was reduced, suggesting that the pyruvate flux was redirected, toward anabolic pathways. Finally, we found a different expression pattern in enzymes involved in glutamine metabolism, and TCA cycle in CoQ depleted cells in comparison to controls. Conclusion: This work elucidated the metabolic alterations in CoQ-depleted cells and provided an insightful understanding of cancer metabolism targeting
Solvent-free fabrication of biphasic lipid-based microparticles with tunable structure
Full text linkLipid-based biphasic microparticles are generally produced by long and complex techniques based on double emulsions. In this study, spray congealing was used as a solvent-free fabrication method with improved processability to transform water-in-oil non-aqueous emulsions into spherical solid lipid-based particles with a biphasic structure (b-MPs). Emulsions were prepared by melt emulsification using different compositions of lipids (Dynasan® 118 and Compritol® 888 ATO), surfactants (Cetylstearyl alcohol and Span® 60) and hydrophilic carriers (PEGs, Gelucire® 48/16 and Poloxamer 188). First, pseudo-ternary phase diagrams were constructed to identify the area corresponding to each emulsion type (coarse emulsion or microemulsion). The hydrophobicity of the lipid mostly affected the interfacial tension, and thus the microstructure of the emulsion. Emulsions were then processed by spray congealing and the obtained b-MPs were characterized in terms of thermal and chemical properties (by DSC and FT-IR), external and internal morphology (by SEM, CLSM and Raman mapping). Solid free-flowing spherical particles (main size range 200–355 μm) with different architectures were successfully produced: microemulsions led to the formation of particles with a homogeneous internal structure, while coarse emulsions generated “multicores-shell” particles consisting of variable size hydrophilic cores evenly distributed within the crystalline lipid phase. Depending on their composition and structure, b-MPs could achieve various release profiles, representing a more versatile system than microparticles based on a single lipid phase. The formulation and technological strategy proposed, provides a feasible and cost-effective way of fabricating b-MPs with tunable internal structure and release behavior
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
