Biodegradation of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis> diethylaniline in a contaminated aquifer: laboratory- and field-scale evidences

The effectiveness of biosparging to mitigate N,N diethylaniline in aquifer was evaluated by measuring the time course of decrease in concentration of the aforementioned compound in aerobic microcosm experiments. The first-order kinetic constant for N,N diethylaniline aerobic biodegradation was estimated from microcosm data (0.037 ± 0.004 d⁻¹), and the value was consistent with the best-fitting value in the transport and reaction model of the aquifer (0.020 d⁻¹). Furthermore, the biodegradability of the compound was evaluated under anaerobic condition in microcosm experiments, which was supported by field modelling. There was no significant degradation in the anaerobic microcosm experiments, confirming the recalcitrance of N,N diethyl aniline under the aforementioned aquifer condition.     

The prominence of and biases in biodiversity and ecosystem functioning research

The sub-discipline of biodiversity and ecosystem functioning (BEF) has emerged as a central topic in contemporary ecological research. However, to date no study has evaluated the prominence and publication biases in BEF research. Herein we report the results of a careful quantitative assessment of BEF research published in five core general ecology journals from 1990 to 2007 to determine the position of BEF research within ecology, identify patterns of research effort within BEF research, and discuss their probable proximal and historical causes. The relative importance of BEF publications increased exponentially during the period analyzed and was significantly greater than the average growth of ecological literature, affirming the prominence of BEF as a current paradigm in ecology. However, BEF research exhibited a strong bias toward experimental studies on terrestrial plant communities, with significantly lower effort devoted to the functional aspects of biodiversity in aquatic systems, multiple trophic level systems, and animal or microbial communities. Such trends may be explained by a combination of methodological adequacy and historic epistemological differences in ecological thinking. We suggest that BEF researchers should direct more effort toward the study of aquatic systems and animal communities, emphasize long-term and trophically complex experiments, such as those with multi-trophic microbial communities, employ larger-scale field observational studies and increase the use of integrative and theoretical studies. Many technical and analytical methodologies that are already employed in ecological research, such as stable isotopes, paleobiology, remote sensing, and model selection criteria, can facilitate these aims. Overcoming the above-mentioned shortcomings of current BEF research will greatly improve our ability to predict how biodiversity loss will affect ecosystem processes and services in natural ecosystems.     

Interaction of aminoadamantane derivatives with the influenza A virus M2 channel-Docking using a pore blocking model

Interaction of aminoadamantanes with the influenza A virus M2 proton channel was analyzed by docking simulations of a series of synthetic aminoadamantane derivatives, of differing binding affinity, into the crystal structure of the transmembrane (M2TM) pore. The pore blocking model tested in the ‘gas phase’ describes qualitatively the changes on the relative binding affinities of the compounds (although a series of highly hydrophobic ligands which seem to have little capacity for different specific interactions with their receptor). The docking calculations predicted poses in which the adamantane ring is surrounded mainly by the alkyl side chains of Val27 or Ala30 and the ligand’s amino group is generally hydrogen bonded with hydroxyls of Ser31 or carbonyls of Val27 or carbonyls of Ala30, the former (Ser31) being the most stable and most frequently observed. The binding of the ligand is a compromise between hydrogen bonding ability, which is elevated by a primary amino group, and apolar interactions, which are increased by the ability of the lipophilic moiety to adequately fill a hydrophobic pocket within the M2TM pore. A delicate balance of these hydrophobic contributions is required for optimal interaction.     

Tissue- and stimulus-dependent role of phosphatidylinositol 3-kinase isoforms for neutrophil recruitment induced by chemoattractants in vivo

PI3K plays a fundamental role in regulating neutrophil recruitment into sites of inflammation but the role of the different isoforms of PI3K remains unclear. In this study, we evaluated the role of PI3Kgamma and PI3Kdelta for neutrophil influx induced by the exogenous administration or the endogenous generation of the chemokine CXCL1. Administration of CXCL1 in PI3Kgamma(-/-) or wild-type (WT) mice induced similar increases in leukocyte rolling, adhesion, and emigration in the cremaster muscle when examined by intravital microscopy. The induction of neutrophil recruitment into the pleural cavity or the tibia-femoral joint induced by the injection of CXCL1 was not significantly different in PI3Kgamma(-/-) or WT mice. Neutrophil influx was not altered by treatment of WT mice with a specific PI3Kdelta inhibitor, IC87114, or a specific PI3Kgamma inhibitor, AS605240. The administration of IC87114 prevented CXCL1-induced neutrophil recruitment only in presence of the PI3Kgamma inhibitor or in PI3Kgamma(-/-) mice. Ag challenge of immunized mice induced CXCR2-dependent neutrophil recruitment that was inhibited by wortmannin or by blockade of and PI3Kdelta in PI3Kgamma(-/-) mice. Neutrophil recruitment to bronchoalveolar lavage induced by exogenously added or endogenous production of CXCL1 was prevented in PI3Kgamma(-/-) mice. The accumulation of the neutrophils in lung tissues was significantly inhibited only in PI3Kgamma(-/-) mice treated with IC87114. Neutrophil recruitment induced by exogenous administration of C5a or fMLP appeared to rely solely on PI3Kgamma. Altogether, our data demonstrate that there is a tissue- and stimulus-dependent role of PI3Kgamma and PI3Kdelta for neutrophil recruitment induced by different chemoattractants in vivo.     

Characterization of a broad range antibacterial substance from a new <Emphasis Type="Italic">Bacillus</Emphasis> species isolated from Amazon basin

A Bacillus sp. strain producing a bacteriocin-like substance was characterized by biochemical profiling and 16S rDNA sequencing. The phylogenetic analysis indicated that this strain has low sequence similarity with most Bacillus spp., suggesting a new species was isolated. The antimicrobial activity was detected starting at the exponential growth phase, and maximum activity was observed at stationary phase. The substance was inhibitory to a broad range of indicator strains, incluing pathogenic and food spoilage bacteria such as Listeria monocytogenes, B. cereus, Aeromonas hydrophila, Erwinia carotovora, Pasteurella haemolytica, Salmonella Gallinarum, among other. The antibacterial substance was stable over a wide pH range, but it was sensitive to pronase E and lipase. The antibacterial substance was bactericidal and bacteriolytic to L. monocytogenes and B. cereus at 160 AU ml⁻¹. The identification of a broad range bacteriocin-like inhibitory substance active against L. monocytogenes addresses an important aspect of food protection against pathogens and spoilage microorganisms.     

New 1,8-naphthyridine and quinoline derivatives as CB2 selective agonists

A series of new 1,8-naphthyridine and quinoline derivatives were synthesized and evaluated for their cannabinoid receptor affinity. In particular, compounds 2, 5, 11, and 13 showed a high CB(2) affinity and CB(2) versus CB(1) selectivity, in agreement with molecular modeling studies. Furthermore, compound 2 also exhibited in vivo antinociceptive effects.     

The impact of polyadenylation signals on plasmid nuclease-resistance and transgene expression

BACKGROUND: Efficient delivery and expression of plasmids (pDNA) is a major concern in gene therapy and DNA vaccination using non-viral vectors. Besides the use of adjuvants, the pDNA vector itself can be designed to maximize survival in nuclease-rich environments. Homopurine-rich tracts in polyadenylation sequences have been previously shown to be especially important in pDNA resistance. METHODOLOGY: The effect of modifications in the poly A sequence of a model pDNA vector (pVAX1GFP) on nuclease resistance and transgene expression was investigated. Four poly A sequences were studied: bovine growth hormone (BGH), mutant BGH, SV40 and a synthetic poly A. Plasmid resistance (half-life) was assessed through in vitro incubations with mammalian nucleases. The impact in transgene expression was studied by quantifying pDNA, mRNA, and GFP expression in CHO, hybridoma and HeLa cells. RESULTS AND CONCLUSIONS: In vitro and cell culture studies indicate that plasmids containing the SV40 and the synthetic poly A sequences present significant improvements in nuclease resistance (up to two-fold increase in half-life). However, RT-PCR analysis demonstrated that significant reduction in mRNA steady-state levels were responsible for a decrease in transgene expression and detected transfection level of CHO and hybridoma cells when using the more resistant plasmids. Interestingly, transfection of HeLa cells demonstrated that both poly A efficiency and plasmid resistance interfere significantly in transgene expression. The results strongly suggest that the choice of the poly A is important, not only for mRNA maturation/stability, but also for pDNA resistance, and should thus be taken into consideration in the design and evaluation of pDNA vectors.     

Immunomodulatory effects of bovine colostrum in human peripheral blood mononuclear cells

Human and bovine colostrum (BC) contain a remarkable amount of bioactive substances, including antibodies towards many common pathogens of the intestinal and respiratory tract as well as growth factors, vitamins, cytokines and other proteic, lipidic and glucidic factors. In this study we investigated whether BC had any immunomodulatory effect on human peripheral blood mononuclear cells (PBMC) from healthy donors. To this aim we focused on the production of IL-12 and IFN-gamma, cytokines involved in the Th1 polarization required for a successful immune response towards intracellular pathogens, such as bacteria and viruses. BC induced a dose-dependent production of IL-12 by CD14+ monocytes, but was unable to induce IFN-gamma production. However, BC differentially affected stimuli-induced IFN-gamma production: it enhanced IFN-gamma in response to weak antigenic stimulation and it inhibited IFN-gamma in response to strong antigenic stimulation. These effects were not dose-dependent. We also measured PBMC proliferation, which was substantially unaffected by BC. Our data suggest that the Th1-promoting activity of BC could contribute, together with the antibodies, to the protective effect of BC on the offspring. BC could also represent an inexpensive therapeutic tool in prevention and treatment of several human microbial infections, including influenza.     

Comparison of a commercial and an in-house T cell-based assay for the diagnosis of Mycobacterium tuberculosis infection

Identification of individuals with a tuberculosis infection is a very important element for the control of tuberculosis. The currently used tuberculin skin test has poor sensitivity and specificity. Recently, an important advance in tuberculosis diagnosis occurred with the development of in vitro T cell-based IFN-gamma release assays. The aim of this study was to compare a RD1-based in-house ELISPOT-IFN-gamma assay with a commercial (T-SPOT.TB) assay for the diagnosis of tuberculosis infection. The results showed an almost complete concordance between the two assays, confirming that our restricted but highly selected pool of peptides is sufficient to detect tuberculosis infection.     

Inferring species decline from collection records: roller dung beetles in Italy (Coleoptera, Scarabaeidae)

The decline of roller dung beetles (Coleoptera, Scarabaeidae) in Italy, at national and regional level, was described using a database of both literature and unpublished data, since the late of 19th century. The probability of finding roller species was assessed for each decade of the 20th century in order to detect changes in their distribution and status. An analysis of decline was performed using a complementary approach of different extinction indexes, according to IUCN criteria. During the 20th century, both the absolute number of records and the UTM cells where roller beetles were found increased clearly as a consequence of the escalation of entomological surveys. Nevertheless, comparing R species (rollers) with all the scarab dung beetles from the first to the last quarter of the 20th century, the relative frequency of roller records decreased by 31%, while the relative number of occupied UTM cells dropped by 23%. Six roller species showed a significant decline in Italy from the first to the second part of the 20th century, and nine in the last 30years. Other two species disappeared from the majority of the northern regions. Finally, the values of all the extinction indexes were strongly correlated and detected a high risk of extinction in Italy for six species. A gradual change in land use during the last three decades, consisting of a reduced extension of grasslands in favour of either intensive agriculture or reforestation after abandonment of livestock raising, was likely the main factor inducing decline and local extinction of roller species.