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31.
Enterococcus populations in Pecorino Abruzzese cheese: biodiversity and safety aspects 总被引:1,自引:0,他引:1
Serio A Paparella A Chaves-López C Corsetti A Suzzi G 《Journal of food protection》2007,70(7):1561-1568
The presence of enterococci in Pecorino Abruzzese cheese during ripening was evaluated. Counts were high, especially in fully ripened summer batches. Seventy strains were isolated and identified based on phenotypical and genotypical features as Enterococcus faecium (48.5%), Enterococcus faecalis (40%), and Enterococcus durans (11.5%), with the first species predominant in spring batches and the second predominant in summer batches. High biodiversity was revealed by random amplification of polymorphic DNA and a PCR assay, suggesting the presence of autochthonous strains. E. faecium isolates were the most resistant to the tested antibiotics, especially to erythromycin, chloramphenicol, and penicillin, but all strains were susceptible to vancomycin, as confirmed by the absence of vanA and vanB genes. The presence of some virulence determinants was investigated, revealing the diffusion of aggregation substance (asal) and gelatinase (gelE) genes in 37.5% of E. faecalis strains. However, none of the isolates produced gelatinase in vitro, suggesting the presence of silent genes. The virulence genes were absent in E. durans. Among E. faecium strains, only Lab 41/1 possessed gelE and asal, whose presence previously has been reported only in E. faecalis. Decarboxylating activity was revealed for phenylalanine (27% of the strains) and tyrosine (96%) but not histidine. The presence of a tyrosine decarboxylase-encoding gene was observed for all strains. A comparison of these results with those of previous studies of clinical and food isolates indicates that enterococci from Pecorino Abruzzese cheese have low pathogenic potential. 相似文献
32.
Evidence that nanoscale surface properties stimulate and guide various molecular and biological processes at the implant/tissue interface is fostering a new trend in designing implantable metals. Cutting-edge expertise and techniques drawn from widely separated fields, such as nanotechnology, materials engineering and biology, have been advantageously exploited to nanoengineer surfaces in ways that control and direct these processes in predictable manners. In this review, we present and discuss the state-of-the-art of nanotechnology-based approaches currently adopted to modify the surface of metals used for orthopedic and dental applications, and also briefly consider their use in the cardiovascular field. The effects of nanoengineered surfaces on various in vitro molecular and cellular events are firstly discussed. This review also provides an overview of in vivo and clinical studies with nanostructured metallic implants, and addresses the potential influence of nanotopography on biomechanical events at interfaces. Ultimately, the objective of this work is to give the readership a comprehensive picture of the current advances, future developments and challenges in the application of the infinitesimally small to biomedical surface science. We believe that an integrated understanding of the in vitro and particularly of the in vivo behavior is mandatory for the proper exploitation of nanostructured implantable metals and, indeed, of all biomaterials. 相似文献
33.
Biava M Porretta GC Poce G Battilocchio C Alfonso S de Logu A Manetti F Botta M 《ChemMedChem》2011,6(4):593-599
Tuberculosis (TB) represents a never-ending challenge toward which research efforts are needed. Drug resistance is the key problem that scientists in the field need to fight. The development of new drugs endowed with novel modes of action against different biological targets is of extreme importance; these new agents should also exhibit lower toxicity compared with the anti-TB drugs currently available. Furthermore, new drugs should be inexpensive since most of the TB-infected population lives in developing nations. In the last few years, numerous researchers have focused their attention on TB, leading to the discovery of some interesting compounds. Among these, the pyrrole-derived compounds we developed can be considered very promising antimycobacterial agents. Aided by molecular modeling studies, we synthesized numerous compounds characterized by the same 1,5-diarylpyrrole scaffold and elucidated very interesting antitubercular/antimycobacterial properties. Some compounds identified are extremely promising and represent a step towards the design of novel lead structures in the fight against TB. Our efforts to this end are reviewed here. 相似文献
34.
Giovanna Grosso Martien A. Hulsen Arash Sarhangi Fard Andrew Overend Patrick D. Anderson 《American Institute of Chemical Engineers》2018,64(3):1034-1048
In many industrial applications, the quality of mixing between different materials is fundamental to guarantee the desired properties of products. However, properly modeling and understanding polymer mixing presents noticeable difficulties, because of the variety and complexity of the phenomena involved. This is also the case with the Cavity Transfer Mixer (CTM), an add‐on to be mounted downstream of existing extruders, to improve distributive mixing. The present work proposes a fully three‐dimensional model of the CTM: a finite element solver provides the transient velocity field, which is used in the mapping method implementation to compute the concentration field evolution and quantify mixing. Several simulations are run assessing the impact on mixing of geometrical and functioning parameters. In general, the number of cavities per row should be limited and the cavity size rather big to guarantee good mixing quality. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1034–1048, 2018 相似文献
35.
Andrea Angius Antonio Mario Scanu Caterina Arru Maria Rosaria Muroni Vincenzo Rallo Giulia Deiana Maria Chiara Ninniri Ciriaco Carru Alberto Porcu Giovanna Pira Paolo Uva Paolo Cossu-Rocca Maria Rosaria De Miglio 《International journal of molecular sciences》2021,22(4)
Colorectal cancer (CRC) is a leading cause of cancer death worldwide, and about 20% is metastatic at diagnosis and untreatable. Increasing evidence suggests that the heterogeneous nature of CRC is related to colorectal cancer stem cells (CCSCs), a small cells population with stemness behaviors and responsible for tumor progression, recurrence, and therapy resistance. Growing knowledge of stem cells (SCs) biology has rapidly improved uncovering the molecular mechanisms and possible crosstalk/feedback loops between signaling pathways that directly influence intestinal homeostasis and tumorigenesis. The generation of CCSCs is probably connected to genetic changes in members of signaling pathways, which control self-renewal and pluripotency in SCs and then establish function and phenotype of CCSCs. Particularly, various deregulated CCSC-related miRNAs have been reported to modulate stemness features, controlling CCSCs functions such as regulation of cell cycle genes expression, epithelial-mesenchymal transition, metastasization, and drug-resistance mechanisms. Primarily, CCSC-related miRNAs work by regulating mainly signal pathways known to be involved in CCSCs biology. This review intends to summarize the epigenetic findings linked to miRNAome in the maintenance and regulation of CCSCs, including their relationships with different signaling pathways, which should help to identify specific diagnostic, prognostic, and predictive biomarkers for CRC, but also develop innovative CCSCs-targeted therapies. 相似文献
36.
Giovanna Calabrese Raffaella Giuffrida Debora Lo Furno Nunziatina Laura Parrinello Stefano Forte Rosario Gulino Cristina Colarossi Luciana Rita Schinocca Rosario Giuffrida Venera Cardile Lorenzo Memeo 《International journal of molecular sciences》2015,16(7):15609-15624
The Low-Affinity Nerve Growth Factor Receptor (LNGFR), also known as CD271, is a member of the tumor necrosis factor receptor superfamily. The CD271 cell surface marker defines a subset of multipotential mesenchymal stromal cells and may be used to isolate and enrich cells derived from bone marrow aspirate. In this study, we compare the proliferative and differentiation potentials of CD271+ and CD271− mesenchymal stromal cells. Mesenchymal stromal cells were isolated from bone marrow aspirate and adipose tissue by plastic adherence and positive selection. The proliferation and differentiation potentials of CD271+ and CD271− mesenchymal stromal cells were assessed by inducing osteogenic, adipogenic and chondrogenic in vitro differentiation. Compared to CD271+, CD271− mesenchymal stromal cells showed a lower proliferation rate and a decreased ability to give rise to osteocytes, adipocytes and chondrocytes. Furthermore, we observed that CD271+ mesenchymal stromal cells isolated from adipose tissue displayed a higher efficiency of proliferation and trilineage differentiation compared to CD271+ mesenchymal stromal cells isolated from bone marrow samples, although the CD271 expression levels were comparable. In conclusion, these data show that both the presence of CD271 antigen and the source of mesenchymal stromal cells represent important factors in determining the ability of the cells to proliferate and differentiate. 相似文献
37.
Giovanna Camara Giudicelli Geraldo M?der Loreta Brand?o de Freitas 《International journal of molecular sciences》2015,16(4):7289-7303
DNA barcoding is a technique for discriminating and identifying species using short, variable, and standardized DNA regions. Here, we tested for the first time the performance of plastid and nuclear regions as DNA barcodes in Passiflora. This genus is a largely variable, with more than 900 species of high ecological, commercial, and ornamental importance. We analyzed 1034 accessions of 222 species representing the four subgenera of Passiflora and evaluated the effectiveness of five plastid regions and three nuclear datasets currently employed as DNA barcodes in plants using barcoding gap, applied similarity-, and tree-based methods. The plastid regions were able to identify less than 45% of species, whereas the nuclear datasets were efficient for more than 50% using “best match” and “best close match” methods of TaxonDNA software. All subgenera presented higher interspecific pairwise distances and did not fully overlap with the intraspecific distance, and similarity-based methods showed better results than tree-based methods. The nuclear ribosomal internal transcribed spacer 1 (ITS1) region presented a higher discrimination power than the other datasets and also showed other desirable characteristics as a DNA barcode for this genus. Therefore, we suggest that this region should be used as a starting point to identify Passiflora species. 相似文献
38.
39.
Daniela Ubiali Carla D. Serra Immacolata Serra Carlo F. Morelli Marco Terreni Alessandra M. Albertini Paolo Manitto Giovanna Speranza 《Advanced Synthesis \u0026amp; Catalysis》2012,354(1):96-104
Purine nucleoside phosphorylase (PNP) from Aeromonas hydrophila encoded by the deoD gene has been over‐expressed in Escherichia coli, purified, characterized about its substrate specificity and used for the preparative synthesis of some 6‐substituted purine‐9‐ribosides. Substrate specificity towards natural nucleosides showed that this PNP catalyzes the phosphorolysis of both 6‐oxo‐ and 6‐aminopurine (deoxy)ribonucleosides. A library of nucleoside analogues was synthesized and then submitted to enzymatic phosphorolysis as well. This assay revealed that 1‐, 2‐, 6‐ and 7‐modified nucleosides are accepted as substrates, whereas 8‐substituted nucleosides are not. A few transglycosylation reactions were carried out using 7‐methylguanosine iodide ( 4 ) as a D ‐ribose donor and 6‐substituted purines as acceptor. In particular, following this approach, 2‐amino‐6‐chloropurine‐9‐riboside ( 2c ), 6‐methoxypurine‐9‐riboside ( 2d ) and 2‐amino‐6‐(methylthio)purine‐9‐riboside ( 2g ) were synthesized in very high yield and purity. 相似文献