130,505 research outputs found
ROLE OF VOCS IN THE INTERACTION OF RHIZOBACTERIA AND PLANT PATHOGENIC FUNGI
No full textROLE OF VOCS IN THE INTERACTION OF RHIZOBACTERIA AND PLANT PATHOGENIC FUNGI
N. S. Iacobellis, A Giorgio, D. Lamorte, and P. Lo Cantore.
Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, Università degli Studi della Basilicata, Viale dell’Ateneo Lucano, 85100, Potenza, Italy; E-mail: [email protected].
Among 162 bacteria isolates obtained from bean plants rhixosphere 60 inhibited in dual plate assays the growth of bean fungal and bacterial pathogens. When the above 60 antagonistic bacteria were applied to bean seeds and the relative plants challenged with a highly virulent strain of X. campestris pv. phaseoli var. fuscans six isolates highly protected bacterized bean plants. The bean plant protection by the six bacterial strains, though at different level, was observed either in in vitro or in greenhouse cotyledon and trifoliate pathogenicity leaf assays, respectively. The Induced Systemic Resistance (ISR) is apparently involved and, in fact, ISR has been recently ascertained in parallel studies using the pathosystem Arapidopsis thaliana and X. c. pv. amoriaceae for 3 of the above rhizobacteria. The six antagonistic bacterial strains did produce an array of hydrolytic enzymes, diffusible antimicrobial substances and Volatile Organic Compounds (VOCs) which inhibit the growth of several plant pathogenic fungi as assessed either in dual plate and VOCs assays. In particular, strains of Sclerotinia sclerotiorum resulted highly sensible to both diffusible and volatiles and for that it was selected for further studies.
Pure synthetic VOCs such as 2-nonanone, 2-undecanone, m-cymene, limonene, dimethy disulfite, dimethyl trisulfide highly inhibited, though with different MIC, the growth of S. slerotiorum strains and showed haemolytic activity suggesting that membrane systems are the target of the above VOCs. Preliminary observation with optical and electron microscopes of S. sclerotiorum mycelia appear to confirm that membrane target for the above VOCs
Bioactive secondary metabolites and hydrolytic enzymes produced by strains of Burkholderia gladioli pv. gladioli
No full textLamorte D., P. Lo Cantore and N. S. Iacobellis
Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, 2Dipartimento di Scienze, Università degli Studi della Basilicata, Viale dell’Ateneo Lucano 10, 85100, Potenza, Italy; E-mail: [email protected]
The genus Burkholderia include more than 40 validly described species associated to plants and animal with beneficial or detrimental features in the occupied niches. Some beneficial Burkholderia species are potentially exploitable in biotechnological and agricultural industry or for bioremediation of recalcitrant xenobiotic but unfortunately the fact that some members of the genus have been involved in human infections is hampering their exploitation.
B. gladioli, initially described as a phytopathogenic species, contains the pathovars gladioli, allicola and agaricicola which causes gladiolus and onion bulb rot, and soft rot of cultivated mushrooms, respectively. Recently, the new pathovar cocovenenans primarily associated to toxicity of food processed from plants commodities, apparently due to the highly toxic compounds toxoflavin and Bongkrekic acid, has been described.
Unlike B. g. pv. agaricicola whose ability to produce antimicrobial secondary metabolites and hydrolytic enzymes as well as the QS regulation of their production and potential role in the pathogen virulence has been recently determined, no information in this regard are available for B. g. pv. gladioli. In this study the production of antimicrobial metabolites in dual plate assays as well as hydrolytic enzymes by representative strains of B. g. pv. gladioli has been ascertained. Liquid culture extracts of virulent strains of B. g. pv. gladioli showed antimicrobial and haemolytic activities. HPLC analyses of bioactive culture extracts gave rise to individual fractions whose chemical and biological characterization has been determined
Characterization of Pseudomonas ”reactans” isolates associated to cultivated mushrooms
No full textCHARACTERIZATION OF PSEUDOMONAS ”REACTANS” ISOLATES ASSOCIATED TO CULTIVATED MUSHROOMS
D. Lamorte, P. Lo Cantore and N. S. Iacobellis
Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, 2Dipartimento di Scienze, Università degli Studi della Basilicata, Viale dell’Ateneo Lucano 10, 85100, Potenza, Italy; E-mail: [email protected]
Pseudomonas “reactans”, considered a saprophyte associated to cultivated mushrooms and used for the identification of P. tolaasii in the white line assay, has been established to be the causal agent of P. eryngii yellowing and to be involved with P. tolaasii and other fluorescent pseudomonads in the development of the brown blotch on A. bisporus and the yellowing of P. ostreatus. The pathogen isolates share the common feature to form white precipitates when grown near P. tolaasii in the “white line” assay and appear to belong to P. fluorescens (biovar III and V) but it is a not yet a classified species.
The purposes of this study was to characterise 20 isolates of P. “reactans” for phenotypic and genotypic traits with the final aim to contribute to its characterization and classification. Isolates were evaluated for biochemical, physiological and nutritional features, for the productions of antimicrobial and hemolytic substances, siderophores and volatile organic compounds (VOCs), and for their pathogenicity on A. bisporus. Pseudomonas-selective PCR primer amplification of the16S rDNA gene and amplicon sequences, deposited at EMBL-EBI, indicate the bacterial isolates as belonging to P. fluorescens though some differences have been observed among the isolates. However, further REP-PCR analysis showed the genetic heterogeneity of the bacterium. Further amplification and sequencing of other housekeeping genes is in progress with final aim to assess the genetic relatedness of P. “reactans” isolates
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Micrornas as new biomarkers for diagnosis and prognosis, and as potential therapeutic targets in acute myeloid leukemia
No full textAcute myeloid leukemias (AML) are clonal disorders of hematopoietic progenitor cells which are characterized by relevant heterogeneity in terms of phenotypic, genotypic, and clinical features. Among the genetic aberrations that control disease development there are microRNAs (miRNAs). miRNAs are small non-coding RNAs that regulate, at post-transcriptional level, translation and stability of mRNAs. It is now established that deregulated miRNA expression is a prominent feature in AML. Functional studies have shown that miRNAs play an important role in AML pathogenesis and miRNA expression signatures are associated with chemotherapy response and clinical outcome. In this review we summarized miRNA signature in AML with different cytogenetic, molecular and clinical characteristics. Moreover, we reviewed the miRNA regulatory network in AML pathogenesis and we discussed the potential use of cellular and circulating miRNAs as biomarkers for diagnosis and prognosis and as therapeutic targets
An update on extracellular vesicles in multiple myeloma: a focus on their role in cell-to-cell cross-talk and as potential liquid biopsy biomarkers
No full textIntroduction: Multiple myeloma (MM) is characterized by a clonal proliferation of neoplastic plasma cells (PCs) in bone marrow (BM) and the interplay between MM PCs and the BM microenvironment, which plays a relevant role in its pathogenesis. In this important cross-talk, extracellular vesicles (EVs) are active. EVs, including small and medium/large EVs, are lipid bi-layer particles released in circulation by normal and neoplastic cells. A selected cargo of lipids, proteins, and nucleic acids is loaded into EVs, and delivered locally and to distant sites, thus influencing the physiology of recipient cells. In the ‘liquid biopsy’ context, EVs can be isolated from human biofluids proving to be powerful markers in cancer. Areas covered: Here, we summarize the recent advances on EVs in MM field. Expert commentary: EVs from MM PCs: i) enhance malignant cell proliferation and aggressiveness through an autocrine loop; ii) are able to transfer drug resistance in sensitive-drug cells; iii) stimulate angiogenesis; iv) increase the activity of osteoclasts; v) have immunosuppressive effects. In addition, EVs from MM stromal cells also promote MM cell proliferation and drug resistance. Finally, we underline the importance of EVs as MM potential biomarkers in ‘cancer liquid biopsy’ and as a potential new therapeutic target
Expansion of dendritic cells derived from human CD34+ cells in static and continuous perfusion cultures
No full textWe examined the effects of different cytokine combinations and culture conditions on the expansion and modulation of cell surface antigens of CD34+ derived dendritic cells (DCs), the most efficient antigen-presenting cells capable of stimulating resting T cells in the primary immune response. Cells with a dendritic morphology and expressing HLA-DR, CD1a, S100 and CD83 were maximally expanded under serum-free conditions with the addition of SCF, GM- CSF, TNF-α, TGF-β and Flt-3 ligand (fold increase of CD1a+ cells = 102 ± 32 after 2 weeks of culture). CD34+ cells were also grown under continuous flow conditions in an artificial capillary system; after 14d of culture, the expansion in the total cell number was lower than that of the static cultures (3.3 ± 2 v 18.9 ± 4) but the percentage of CD1a+/CD83+/CD80+ cells was considerably higher, whereas the CD14+ cells were significantly reduced (8.9 ± 2 v 26 ± 13). In continuous perfusion cultures, low levels of DC precursors and of LTC-IC were still present up to day 14. The DCs generated under flow conditions stimulated the mixed leucocyte reaction (MLR) more than the cells grown in static cultures. By electron microscopy, cells grown in the continuous flow system showed an increased number of large cells with numerous dendritic processes and abundant multilamellar complexes. The cells expanded under these conditions were sorted on the basis of their light- scatter properties into two fractions: one containing a predominance of CD1a+/S100+/CD83+/CD80+/CD14- 'large cells' with great internal complexity (mature DCs); the second including 'small cells' either CD33+/CD14+, CD33+/CD15+ or CD33+/CD13(±)/CD14-. The DCs generated and selected with this method are therefore particularly well suited for immunotherapeutic protocols
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