The effects of pesticides on bacterial nitrogen fixers in peanut-growing area

In the peanut production, the applications of herbicides and fungicides are a common practice. In this work, studies done under field conditions demonstrated that pesticides affected negatively the number and nitrogenase activity of diazotrophic populations of soil. Agrochemical effects were not transient, since these parameters were not recovered to pre-treatment levels even 1 year after pesticides application. Results obtained from greenhouse experiments revealed that the addition of herbicide or fungicides diminished the free-living diazotrophs number reaching levels found in soil amended with the pesticides and that the number of symbiotic diazotrophs was not affected by the insecticide assayed. The soil nitrogenase activity was not affected by fungicides and glyphosate. The effect of pesticides on the nitrogen-fixing bacteria diversity was evaluated both in field and greenhouse experiments. Analysis of clone libraries generated from the amplification of soil nifH gene showed a diminution in the genetic diversity of this bacterial community.     

Attachment and Biofilm Forming Capabilities of Staphylococcus epidermidis Strains Isolated from Preterm Infants

Staphylococcus epidermidis, a human commensal, is an important opportunistic, biofilm-forming pathogen and the main cause of late onset sepsis in preterm infants, worldwide. In this study we describe the characteristics of S. epidermidis strains causing late onset (>72 h) bloodstream infection in preterm infants and skin isolates from healthy newborns. Attachment and biofilm formation capability were analyzed in microtiter plates and with transmission electron microscopy (TEM). Clonal relationship among strains was studied with pulsed-field gel electrophoresis. Antimicrobial susceptibility testing was performed, as well as the detection of biofilm-associated genes and of the invasiveness marker IS256 with polymerase chain reaction. Blood and skin isolates had similar attachment and biofilm-forming capabilities and biofilm formation was not related to the presence of specific genes. Filament-like membrane structures were seen by TEM early in the attachment close to the device surface, both in blood and skin strains. Nine of the ten blood isolates contained the IS256 and were also resistant to methicillin and gentamicin in contrast to skin strains. S. epidermidis strains causing bloodstream infection in preterm infants exhibit higher antibiotic resistance and are provided with an invasive genetic equipment compared to skin commensal strains. Adhesion capability to a device surface seems to involve bacterial membrane filaments.     

11 Findings and hurdles on the path leading from formamide to the spontaneous generation of RNA

Our laboratories analyze the synthetic reactions leading from formamide, NH₂COH to prebiotically relevant compounds in the presence of catalysts. We have described the formation of all the biological nucleic bases of carboxylic acids of two aminoacids, and of condensing agents in the presence of catalysts of terrestrial origin (Saladino et al., 2012) and of one meteorite. Heat-dependent synthetic reactions from NH₂COH lead to the synthesis of acyclonucleosides, not (yet?) to that of nucleosides [hurdle # 1]. Nucleosides are phosphorylated in the presence of NH₂COH and a phosphate source yielding cyclic nucleotides as well. (Costanzo et al., 2007). 3′,5′-cyclic GMP nonenzymatically polymerizes up to at least 25mers, as shown by PAGE, MALDI ToF, ³¹P-NMR, specific RNAse and inhibitors analyses (Costanzo et al., 2012).The reaction is stimulated by 1,8-diazabicycloundec-7-ene and dimethylformamide. 3′,5′-cUMP does not polymerize spontaneously [hurdle # 2], 3′,5′-cAMP polymerizes very poorly [hurdle # 3]. We will discuss data on the polymerization of 3′,5′-cCMP and on a ribozyme activity exerted by oligomers neosynthesized from cyclic nucleotides. This approach finds its larger perspective in the evolutionary scenario depicted by Trifonov (2009).     

A class of pyrrole derivatives endowed with analgesic/anti-inflammatory activity

We report the synthesis and bio-pharmacological evaluation of a class of pyrrole derivatives featuring a small appendage fragment (carbaldehyde, oxime, nitrile) on the central core. Compound 1c proved to be extremely effective in vivo, showing an interesting anti-nociceptic profile that is comparable to reference compounds already marketed, hence representing a great stimulus for a further improvement of this class of molecules.     

A Low Cost Metal-Free Vascular Access Mini-Port for Artifact Free Imaging and Repeated Injections in Mice

Purpose

Small injection ports for mice are increasingly used for drug testing or when administering contrast agents. Commercially available mini-ports are expensive single-use items that cause imaging-artifacts. We developed and tested an artifact-free, low-cost, vascular access mini-port (VAMP) for mice.

Procedures

Leakage testing of the VAMP was conducted with high speed bolus injections of different contrast agents. VAMP-induced artifacts were assessed using a micro-CT and a small animal MRI (9.4T) scanner ex vivo. Repeated contrast administration was performed in vivo.

Results

With the VAMP there was no evidence of leakage with repeated punctures, high speed bolus contrast injections, and drawing of blood samples. In contrast to the tested commercially available ports, the VAMP did not cause artifacts with MRI or CT imaging.

Conclusions

The VAMP is an alternative to commercially available mini-ports and has useful applications in animal research involving imaging procedures and contrast agent testing.     

In Vitro and In Vivo Antitumor Activity of [Pt(O,O′-acac)(γ-acac)(DMS)] in Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive malignancy highly resistant to chemotherapy. There is an urgent need for effective therapy inasmuch as resistance, intrinsic and acquired, to conventional therapies is common. Among Pt(II) antitumor drugs, [Pt(O,O′-acac)(γ-acac)(DMS)] (Ptac2S) has recently attracted considerable attention due to its strong in vitro and in vivo antiproliferative activity and reduced toxicity. The purpose of this study was to examine the efficacy of Ptac2S treatment in MPM. We employed the ZL55 human mesothelioma cell line in vitro and in a murine xenograft model in vivo, to test the antitumor activity of Ptac2S. Cytotoxicity assays and Western blottings of different apoptosis and survival proteins were thus performed. Ptac2S increases MPM cell death in vitro and in vivo compared with cisplatin. Ptac2S was more efficacious than cisplatin also in inducing apoptosis characterized by: (a) mitochondria depolarization, (b) increase of bax expression and its cytosol-to-mitochondria translocation and decrease of Bcl-2 expression, (c) activation of caspase-7 and -9. Ptac2S activated full-length PKC-δ and generated a PKC-δ fragment. Full-length PKC-δ translocated to the nucleus and membrane, whilst PKC-δ fragment concentrated to mitochondria. Ptac2S was also responsible for the PKC-ε activation that provoked phosphorylation of p38. Both PKC-δ and PKC-ε inhibition (by PKC–siRNA) reduced the apoptotic death of ZL55 cells. Altogether, our results confirm that Ptac2S is a promising therapeutic agent for malignant mesothelioma, providing a solid starting point for its validation as a suitable candidate for further pharmacological testing.     

The European antibody network's practical guide to finding and validating suitable antibodies for research

Antibodies are widely exploited as research/diagnostic tools and therapeutics. Despite providing exciting research opportunities, the multitude of available antibodies also offers a bewildering array of choice. Importantly, not all companies comply with the highest standards, and thus many reagents fail basic validation tests. The responsibility for antibodies being fit for purpose rests, surprisingly, with their user. This paper condenses the extensive experience of the European Monoclonal Antibody Network to help researchers identify antibodies specific for their target antigen. A stepwise strategy is provided for prioritising antibodies and making informed decisions regarding further essential validation requirements. Web-based antibody validation guides provide practical approaches for testing antibody activity and specificity. We aim to enable researchers with little or no prior experience of antibody characterization to understand how to determine the suitability of their antibody for its intended purpose, enabling both time and cost effective generation of high quality antibody-based data fit for publication.     

Pyrazolo[1,5-a]quinazoline scaffold as 5-deaza analogue of pyrazolo[5,1-c][1,2,4]benzotriazine system: synthesis of new derivatives,biological activity on GABAA receptor subtype and molecular dynamic study

To investigate the binding affinity of GABA_A receptor subtype, new pyrazolo [1,5-a]quinazolines were designed, synthesized, and in vitro evaluated. These compounds, 5-deaza analogues of pyrazolo[5,1-c][1,2,4]benzotriazine derivatives which were already studied in our research group, permit us to evaluate the relevance of the nitrogen or the oxygen atom at 5-position of the tricyclic scaffold. Molecular dynamic study was done on a set of the new and known ligands to rationalize and to explain the lack of affinity on the 4- or 5-substituted new derivative. In fact, from biological results, it can be found that the only 5-unsubstituted new derivative, compound 15, has receptor recognition (K_i?=?834.7?nM).     

Cinnoline derivatives as human neutrophil elastase inhibitors

Compounds that can effectively inhibit the proteolytic activity of human neutrophil elastase (HNE) represent promising therapeutics for treatment of inflammatory diseases. We present here the synthesis, structure–activity relationship analysis, and biological evaluation of a new series of HNE inhibitors with a cinnoline scaffold. These compounds exhibited HNE inhibitory activity but had lower potency compared to N-benzoylindazoles previously reported by us. On the other hand, they exhibited increased stability in aqueous solution. The most potent compound, 18a, had a good balance between HNE inhibitory activity (IC₅₀ value?=?56?nM) and chemical stability (t_1/2?=?114?min). Analysis of reaction kinetics revealed that these cinnoline derivatives were reversible competitive inhibitors of HNE. Furthermore, molecular docking studies of the active products into the HNE binding site revealed two types of HNE inhibitors: molecules with cinnolin-4(1H)-one scaffold, which were attacked by the HNE Ser195 hydroxyl group at the amido moiety, and cinnoline derivatives containing an ester function at C-4, which is the point of attack of Ser195.