A new hadrosaurid dentary from the latest Maastrichtian of the Pyrenees (north Spain) and the high diversity of the duck-billed dinosaurs of the Ibero-Armorican Realm at the very end of the Cretaceous

In the latest Maastrichtian, the European hadrosauroid fauna was more diverse than those of North America and Asia. The European record of hadrosaurid dentaries is an example of this diversity, and most of the sites with mandibular remains are located in the Ibero-Armorican Realm. Within the Iberian Peninsula, most of the remains are located in the Tremp Basin (South Central Pyrenees). Two of the three valid hadrosaurid taxa defined in this basin are from the Blasi sites (Arén, Huesca province): Arenysaurus ardevoli (Blasi-3) and Blasisaurus canudoi (Blasi-1). A new locality in Blasi (Blasi 3.4) has provided a new dentary from an indeterminate euhadrosaurid. This dentary presents some characters intermediate between Arenysaurus and Blasisaurus, some characters similar to Pararhabdodon isonensis (from the nearby province of Lleida), and some characters of its own. Nevertheless, due to its fragmentary character, without dentition or its edentulous anterior part, it cannot be determined above the level of Euhadrosauria. It thus represents a fourth Iberian euhadrosaurian taxon in the Ibero-Armorican Realm, different from Arenysaurus, Blasisaurus and Pararhabdodon, increasing the diversity of hadrosauroids in this realm at the very end of the Cretaceous.     

Computational DNA binding studies of (–)-epigallocatechin-3-gallate

The catechin family of molecules that are present in the leaves of green tea has been under investigation since the antioxidant and anti-inflammatory properties of tea were discovered. Among multiple proposed therapeutic targets of these molecules, the direct interaction with nucleic acids has been proposed and experimentally observed but without clear knowledge about the potential binding modes between these ligands and DNA. One of these catechin structures, (–)-epigallocatechin gallate (EGCG), has three aromatic rings that could interact with double-stranded DNA via terminal base-pair stacking, intercalation, or through groove binding. Using enhanced sampling techniques and molecular dynamics simulations, we have found a stable complex between the EGCG ligand and DNA through intercalation of the trihydroxybenzoate aromatic ring and an ApC step. Moreover, we have calculated the absorption spectra of four possible binding modes and compared these to absorption profiles reported in the literature, and explored the possible DNA sequence preference for the EGCG ligand to bind. Our results suggest that an intercalative mode of interaction through the major groove is possible between the EGCG ligands and DNA with apparently very little DNA sequence selectivity.     

The effect of plant growth-promoting rhizobacteria on the growth of rice (Oryza sativa L.) cropped in southern Brazilian fields

Background and Aims

Several strains of rhizobacteria may be found in the rhizospheric soil, on the root surface or in association with rice plants. These bacteria are able to colonize plant root systems and promote plant growth and crop yield through a variety of mechanisms. The objectives of this study were to isolate, identify, and characterize putative plant growth-promoting rhizobacteria (PGPR) associated with rice cropped in different areas of southern Brazil.

Methods

Bacterial strains were selectively isolated based on their growth on three selective semi-solid nitrogen-free media. Bacteria were identified at the genus level by PCR-RFLP 16S rRNA gene analysis and partial sequencing methodologies. Bacterial isolates were evaluated for their ability to produce indolic compounds and siderophores and to solubilize phosphate. In vitro biological nitrogen fixation and the ability to produce 1-aminocyclopropane-1-carboxylate deaminase were evaluated for each bacterial isolate used in the inoculation experiments.

Results

In total, 336 bacterial strains were isolated representing 31 different bacterial genera. Strains belonging to the genera Agrobacterium, Burkholderia, Enterobacter, and Pseudomonas were the most prominent isolates. Siderophore and indolic compounds producers were widely found among isolates, but 101 isolates were able to solubilize phosphate. Under gnotobiotic conditions, eight isolates were able to stimulate the growth of rice plants. Five of these eight isolates were also field tested in rice plants subjected to different nitrogen fertilization rates.

Conclusions

The results showed that the condition of half-fertilization plus separate inoculation with the isolates AC32 (Herbaspirillum sp.), AG15 (Burkholderia sp.), CA21 (Pseudacidovorax sp.), and UR51 (Azospirillum sp.) achieved rice growth similar to those achieved by full-fertilization without inoculation, thus highlighting the potential of these strains for formulating new bioinoculants for rice crops.     

Taxonomy of the ‘Synargis axenus complex’ belonging to the ‘Synargis regulus’ species group,with a phylogenetic reassessment of the genus Synargis Hübner, 1819 (Lepidoptera: Riodinidae: Nymphidiini)

Three new species of Synargis Hübner, 1819, from Paraguay and southern and central Brazil are described: Synargis fandanga sp. nov. from Paraguay (Amambay and Paraguari) and southern Brazil (Paraná and Santa Catarina), Synargis rasqueada sp. nov. from central Brazil (Mato Grosso), and Synargis gorpa sp. nov. from southern Brazil (Paraná, Santa Catarina, and Rio Grande do Sul). Lectotypes are designated for Lemonias axenus Hewitson, 1876, Ematurgina axenus ochrophlegma Sitchel, 1911, Ematurgina acervata Seitz, 1932, and Ematurgina perrupta Seitz, 1932. Ematurgina ochrophlegma f. dissimilis Hayward, 1949, is a new synonym of Synargis bifasciata (Mengel, 1902), and Ematurgina ochrophlegma f. distincta Hayward, 1949, is a new synonym of Synargis axenus (Hewitson, 1876). The revalidation of E. perrupta Seitz, 1932, and the new status Synargis ochrophlegma (Stichel, 1911) are proposed. Ematurgina perrupta ab. roeberi Seitz, 1932, and Ematurgina bifasciata ochrophlegma ab. leucomelaina Breyer, 1930, are considered unavailable names. Based on a previous phylogenetic hypothesis, the phylogeny of the genus Synargis is reassessed, adding these new and revalidated taxa, and nine additional characters. The ‘Synargis regulus’ species group and the ‘Synargis axenus complex’ are recovered as monophyletic, with S. gorpa sp. nov. sister to the remaining species of the ‘S. axenus complex’. Additionally, an up‐to‐date geographical distribution map and a dichotomous key are provided, and the taxonomy of the taxa involved is discussed. © 2013 The Linnean Society of London     

5′‐ectonucleotidase mediates multiple‐drug resistance in glioblastoma multiforme cells

Glioblastoma multiforme (GBM) cells are characterised by their extreme chemoresistance. The activity of multiple‐drug resistance (MDR) transporters that extrude antitumor drugs from cells plays the most important role in this phenomenon. To date, the mechanism controlling the expression and activity of MDR transporters is poorly understood. Activity of the enzyme ecto‐5′‐nucleotidase (CD73) in tumor cells, which hydrolyses AMP to adenosine, has been linked to immunosuppression and prometastatic effects in breast cancer and to the proliferation of glioma cells. In this study, we identify a high expression of CD73 in surgically resected samples of human GBM. In primary cultures of GBM, inhibition of CD73 activity or knocking down its expression by siRNA reversed the MDR phenotype and cell viability was decreased up to 60% on exposure to the antitumoral drug vincristine. This GBM chemosensitization was caused by a decrease in the expression and activity of the multiple drug associated protein 1 (Mrp1), the most important transporter conferring multiple drug resistance in these cells. Using pharmacological modulators, we have recognized the adenosine A₃ receptor subtype in mediation of the chemoresistant phenotype in these cells. In conclusion, we have determined that the activity of CD73 to trigger adenosine signaling sustains chemoresistant phenotype in GBM cells. J. Cell. Physiol. 228: 602–608, 2013. © 2012 Wiley Periodicals, Inc.     

nAChR‐induced octopamine release mediates the effect of nicotine on a startle response in Drosophila melanogaster

Biogenic amines (BAs) play a central role in the generation of complex behaviors in vertebrates and invertebrates, including the fly Drosophila melanogaster. The comparative advantages of Drosophila as a genetic model to study the contribution of BAs to behaviors stumble upon the difficulty to access the fly brain to ask relevant physiological questions. For instance, it is not known whether the activation of nicotinic acetylcholine receptors (nAChRs) induces the release of BAs in fly brain, a phenomenon associated to several behaviors in vertebrates. Here, we describe a new preparation to study the efflux of BAs in the adult fly brain by in vitro chronoamperometry. Using this preparation we show that nAChR agonists including nicotine induce a fast, transient, dose‐dependent efflux of endogenous BAs, an effect mediated by α‐bungarotoxin‐sensitive nAChRs. By using different genetic tools we demonstrate that the BA whose efflux is induced by nAChR activation is octopamine (Oct). Furthermore, we show that the impairment of a mechanically induced startle response after nicotine exposure is not observed in flies deficient in Oct transmission. Thus, our data show that the efflux of BAs in Drosophila brain is increased by nAChR activation as in vertebrates, and that then AChR‐induced Oct release could have implications in a nicotine‐induced behavioral response.     

Specificity of the rapid rK39 antigen-based immunochromatographic test Kalazar Detect(r) in patients with cutaneous leishmaniasis in Brazil

The aim of this study was to evaluate the specificity of a rapid immunochromatographic test that was developed to detect antibodies against the rK39 antigen for the diagnosis of visceral leishmaniasis (VL). This evaluation was performed using sera from patients with a confirmed diagnosis of active cutaneous leishmaniasis. The sera from 272 patients with a confirmed diagnosis of localised cutaneous leishmaniasis (CL) who resided in an area endemic for Leishmania braziliensis in Brazil were obtained before the initiation of antileishmanial treatment. Kalazar Detect^(r)(InBios, Seattle, WA) recombinant K39 antigen-based immunochromatographic strips were used according to the manufacturer''s instructions. The test results were evaluated independently by two examiners in sequential order. The positive controls for the test included five serum samples from five patients with parasitologically confirmed diagnosis of VL caused by Leishmania infantum in Brazil. Overall, 100% of the samples obtained from patients with CL were negative, confirming the absence of a serological cross-reaction for individuals with cutaneous disease when these patients were evaluated using the rapid test. The lack of a cross-reaction in patients who were infected by parasites of the same genus highlights the specificity of the rK39 antigen for the diagnosis of VL in areas with the sympatric circulation of L. braziliensis and L. infantum.     

Synthesis of Fucosyl-N-Acetylglucosamine Disaccharides by Transfucosylation Using α-l-Fucosidases from Lactobacillus casei

AlfB and AlfC α-l-fucosidases from Lactobacillus casei were used in transglycosylation reactions, and they showed high efficiency in synthesizing fucosyldisaccharides. AlfB and AlfC activities exclusively produced fucosyl-α-1,3-N-acetylglucosamine and fucosyl-α-1,6-N-acetylglucosamine, respectively. The reaction kinetics showed that AlfB can convert 23% p-nitrophenyl-α-l-fucopyranoside into fucosyl-α-1,3-N-acetylglucosamine and AlfC at up to 56% into fucosyl-α-1,6-N-acetylglucosamine.     

Bacterial community composition of anthropogenic biochar and Amazonian anthrosols assessed by 16S rRNA gene 454 pyrosequencing

Biochar (BC) is a common minor constituent of soils and is usually derived from the burning of wood materials. In the case of Amazonian dark earth (ADE) soils, the increased amount of this material is believed to be due to anthropogenic action by ancient indigenous populations. In this study, we use 16S rRNA gene pyrosequencing to assess the bacterial diversity observed in the BC found in ADEs as well as in the dark earth itself and the adjacent Acrisol. Samples were taken from two sites, one cultivated with manioc and one with secondary forest cover. Analyses revealed that the community structure found in each sample had unique features. At a coarse phylogenetic resolution, the most abundant phyla in all sequence libraries were Actinobacteria, Acidobacteria, Verrucomicrobia and Proteobacteria that were present in similar relative abundance across all samples. However, the class composition varied between them highlighting the difference between the Acrisol and the remaining samples. This result was also corroborated by the comparison of the OTU composition (at 97 % identity). Also, soil coverage has shown an effect over the community structure observed in all samples. This pattern was found to be significant through unweighted UniFrac as well as P tests. These results indicate that, although the ADEs are found in patches within the Acrisols, the contrasting characteristics found between them led to the development of significantly different communities.     

White rot Basidiomycetes isolated from Chiloé National Park in Los Lagos region, Chile

Wood decomposition is an important component in forest ecosystems but information about the diversity of fungi causing decay is lacking. This is especially true for the temperate rain forests in Chile. These investigations show results of a biodiversity study of white-rot fungi in wood obtained from Chiloé National Park in Los Lagos region, Chile. Culturing from white-rotted wood followed by sequencing of the complete internal transcribed spacer region of the ribosomal DNA (rDNA) or partial large subunit region of the rDNA, identified 12 different species in the Basidiomycota. All of these fungi were characterized as white rot fungi and were identified with a BLAST match of 97 % or greater to sequences in the GenBank database. Fungi obtained were species of Phlebia, Mycoacia, Hyphodontia, Bjerkandera, Phanerochaete, Stereum, Trametes, and Ceriporiopsis. This report identifies for the first time in Chile the species Ceriporiopsis subvermispora, Hyphodontia radula, Phlebia radiata, Phanerochaete affinis, Peniophora cinerea, Stereum gausapatum, Phlebia setulosa and Phanerochaete sordida. Scanning electron microscopy was used to characterize the type of decay caused by the fungi that were isolated and a combination of selective lignin degraders and simultaneous white rot fungi were found. Fungi that cause a selective degradation of lignin are of interest for bioprocessing technologies that require modification or degradation of lignin without cellulose removal.