Evidence of a landlocked reproducing population of the marine pejerrey Odontesthes argentinensis (Actinopterygii; Atherinopsidae)

In South America, the order Atheriniformes includes the monophyletic genus Odontesthes with 20 species that inhabit freshwater, estuarine and coastal environments. Pejerrey Odontesthes argentinensis is widely distributed in coastal and estuarine areas of the Atlantic Ocean and is known to foray into estuaries of river systems, particularly in conditions of elevated salinity. However, to our knowledge, a landlocked self-sustaining population has never been recorded. In this study, we examined the pejerrey population of Salada de Pedro Luro Lake (south-east of Buenos Aires Province, Argentina) to clarify its taxonomic identity. An integrative taxonomic analysis based on traditional meristic, landmark-based morphometrics and genetic techniques suggests that the Salada de Pedro Luro pejerrey population represents a novel case of physiological and morphological adaptation of a marine pejerrey species to a landlocked environment and emphasises the environmental plasticity of this group of fishes.     

Diverging effects of human recombinant anti-hepatitis C virus (HCV) antibody fragments derived from a single patient on the infectivity of a vesicular stomatitis virus/HCV pseudotype

Hepatitis C virus (HCV) is the major causative agent of blood-borne non-A, non-B hepatitis. Although a strong humoral response is detectable within a few weeks of primary infection and during viral persistence, the role played by antibodies against HCV envelope glycoproteins in controlling viral replication is still unclear. We describe how human monoclonal anti-HCV E2 antibody fragments isolated from a chronically HCV-infected patient differ sharply in their abilities to neutralize infection of HepG2 cells by a vesicular stomatitis virus pseudotype bearing HCV envelope glycoproteins. Two clones were able to neutralize the pseudotype virus at a concentration of 10 micro g/ml, while three other clones completely lacked this activity. These data can explain the lack of protection and the possibility of reinfection that occur even in the presence of a strong antiviral antibody response.     

β-Arrestin Recruitment and Biased Agonism at Free Fatty Acid Receptor 1

FFAR1/GPR40 is a seven-transmembrane domain receptor (7TMR) expressed in pancreatic β cells and activated by FFAs. Pharmacological activation of GPR40 is a strategy under consideration to increase insulin secretion in type 2 diabetes. GPR40 is known to signal predominantly via the heterotrimeric G proteins G_q/11. However, 7TMRs can also activate functionally distinct G protein-independent signaling via β-arrestins. Further, G protein- and β-arrestin-based signaling can be differentially modulated by different ligands, thus eliciting ligand-specific responses (“biased agonism”). Whether GPR40 engages β-arrestin-dependent mechanisms and is subject to biased agonism is unknown. Using bioluminescence resonance energy transfer-based biosensors for real-time monitoring of cell signaling in living cells, we detected a ligand-induced GPR40-β-arrestin interaction, with the synthetic GPR40 agonist TAK-875 being more effective than palmitate or oleate in recruiting β-arrestins 1 and 2. Conversely, TAK-875 acted as a partial agonist of G_q/11-dependent GPR40 signaling relative to both FFAs. Pharmacological blockade of G_q activity decreased FFA-induced insulin secretion. In contrast, knockdown or genetic ablation of β-arrestin 2 in an insulin-secreting cell line and mouse pancreatic islets, respectively, uniquely attenuated the insulinotropic activity of TAK-875, thus providing functional validation of the biosensor data. Collectively, these data reveal that in addition to coupling to G_q/11, GPR40 is functionally linked to a β-arrestin 2-mediated insulinotropic signaling axis. These observations expose previously unrecognized complexity for GPR40 signal transduction and may guide the development of biased agonists showing improved clinical profile in type 2 diabetes.     

The "far-west" of Anopheles gambiae molecular forms

The main Afrotropical malaria vector, Anopheles gambiae sensu stricto, is undergoing a process of sympatric ecological diversification leading to at least two incipient species (the M and S molecular forms) showing heterogeneous levels of divergence across the genome. The physically unlinked centromeric regions on all three chromosomes of these closely related taxa contain fixed nucleotide differences which have been found in nearly complete linkage disequilibrium in geographic areas of no or low M-S hybridization. Assays diagnostic for SNP and structural differences between M and S forms in the three centromeric regions were applied in samples from the western extreme of their range of sympatry, the only area where high frequencies of putative M/S hybrids have been reported. The results reveal a level of admixture not observed in the rest of the range. In particular, we found: i) heterozygous genotypes at each marker, although at frequencies lower than expected under panmixia; ii) virtually all possible genotypic combinations between markers on different chromosomes, although genetic association was nevertheless detected; iii) discordant M and S genotypes at two X-linked markers near the centromere, suggestive of introgression and inter-locus recombination. These results could be indicative either of a secondary contact zone between M and S, or of the maintenance of ancestral polymorphisms. This issue and the perspectives opened by these results in the study of the M and S incipient speciation process are discussed.     

Can S-LCA methodology support responsible sourcing of raw materials in EU policy context?

Purpose

Access, affordability and sustainability of raw material supply chains are crucial to the sustainable development of the European Union (EU) for both society and economy. The study investigates whether and how the social life cycle assessment (S-LCA) methodology can support responsible sourcing of raw materials in Europe. The potential of social indicators already available in an S-LCA database is tested for the development of new metrics to monitor social risks in raw material industries at EU policy level.

Methods

The Product Social Impact Life Cycle Assessment (PSILCA) database was identified as a data and indicators source to assess social risks in raw material industries in EU-28 and extra-EU countries. Six raw material country sectors in the scope of the European policy on raw materials were identified and aggregated among those available in PSILCA. The selection of indicators for the assessment was based on the RACER (Relevance, Acceptance, Credibility, Ease, Robustness) analysis, leading to the proposal of 9 social impact categories. An S-LCA of the selected raw material industries was, thus, performed for the EU-28 region, followed by a contribution analysis to detect direct and indirect impacts and investigate related supply chains. Finally, the social performance of raw material sectors in EU-28 was compared with that of six extra-EU countries.

Results and discussion

Considering the overall social risks in raw material industries, “Corruption”, “Fair salary”, “Health and safety” and “Freedom of association and collective bargaining” emerged as the most significant categories both in EU and extra-EU. EU-28 shows an above-average performance where the only exception is represented by the mining and quarrying sector. An investigation of the most contributing processes to social impact categories for EU-28 led to the identification of important risks originating in the supply chain and in extra-EU areas. Therefore, the S-LCA methodology confirmed the potential of a life cycle perspective to detect burdens shifting and trade-offs. However, only a limited view on the sectoral social performance could be obtained from the research due to a lack of social data.

Conclusions

The S-LCA methodology and indicators appear appropriate to perform an initial social sustainability screening, thus enabling the identification of hotspots in raw material supply chains and the prioritization of areas of action in EU policies. Further methodological developments in the S-LCA field are necessary to make the approach proposed in the paper fully adequate to support EU policies on raw materials.

     

Development of a modified transformation platform for apomixis candidate genes research in Paspalum notatum (bahiagrass)

The aim of this work was to improve existing transformation protocols and to transform specific genotypes of Paspalum notatum (bahiagrass) for functional analyses of candidate genes involved in reproduction. Three different explants were assayed for in vitro plant regeneration: mature seeds, mature embryos, and shoot meristems. Plant regeneration was achieved with all explant types, but mature seeds produced the optimal rate (78.0%) and were easiest to manipulate. A method based on serial re-induction of calli from meristems of the regenerated lines was also developed, which could be useful in plant breeding strategies pursuing somaclonal variation. Transient transformation experiments were performed on calli obtained from mature seeds using a compressed helium gene gun. Transient transformation constructs included anthocyanin-synthesis genes cloned under the CAMV 35S promoter and an enhanced green fluorescent protein gene (egfp) driven by the rice actin1 (act1) promoter. Selection curves for ammonium glufosinate were developed in order to determine the optimal selective pressure for stable transformation (1.0 mg/L). Stable co-transformation experiments were carried out with two different constructs containing: (1) the reporter egfp gene cloned under the rice act1 promoter and (2) the selector bar gene driven by the ubiquitin promoter. A total of 27 (64.2%) transgenic plants out of 42 resistant plants analyzed were obtained. The presence of the transgenes in regenerated plants was confirmed by polymerase chain reaction and DNA gel blot analysis. Gene expression was demonstrated by eGFP fluorescence detection and in vivo assays for ammonium glufosinate tolerance. This platform is being used to generate transgenic plants of P. notatum to analyze the function of apomixis-associated candidate genes.     

Evaluation of Relapse-Free Survival in T3N0 Colon Cancer: The Role of Chemotherapy,a Multicentric Retrospective Analysis

Background

Adjuvant chemotherapy (AC) in Stage II Colon Cancer (CC) is still under debate. Choice should be based on patients and disease characteristics. According to guidelines AC should be considered in high-risk T3N0 patients. No data are available for better option in low-risk patients. The aim of the study is to retrospectively evaluate relapse-free survival (RFS) and disease-free survival (DFS) according to treatment received in T3N0 CC.

Methods

RFS and DFS are evaluated with Kaplan-Meier method. Multivariate Cox proportional hazard model was developed using stepwise regression, enter limit and remove limit were p = 0.10 and p = 0.15, respectively.

Results

834 patients with T3N0 CC were recruited. Median age was 69 (29–93), M/F 463/371, 335 low-risk patients (40.2%), 387 high-risk (46.4%), 112 unknown (13.4%); 127 (15.2%) patients showed symptoms at diagnosis. Median sampled lymph nodes were 15 (1–76); 353 (42.3%) patients were treated with AC. Median follow up was 5 years (range 3–24). The 5-years RFS was 78.4% and the 5-years DFS was 76.7%. At multivariate analysis symptoms, lymph nodes, and adjuvant chemotherapy were prognostic factors for RFS. AC is prognostic factor for all endpoints.In low-risk group 5-years RFS was 87.3% in treated patients and 74.7% in non-treated patients (p 0.03); in high-risk group was respectively 82.7% and 71.4% (p 0.005).

Conclusions

Data confirmed the role of known prognostic factors and suggest the relevance of adjuvant chemotherapy also in low-risk stage II T3N0 CC patients. However, the highest risk in low-risk subgroup should be identified to be submitted to AC.     

Glucose transport in lysosomal membrane vesicles. Kinetic demonstration of a carrier for neutral hexoses

Lysosomal membrane vesicles isolated from rat liver were exploited to analyze the mechanism of glucose transport across the lysosomal membrane. Uptake kinetics of [14C]D-glucose showed a concentration-dependent saturable process, typical of carrier-mediated facilitated transport, with a Kt of about 75 mM. Uptake was unaffected by Na+ and K+ ions, membrane potentials, and proton gradients but showed an acidic pH optimum. Lowering the pH from 7.4 to 5.5 had no effect on the affinity of the carrier for the substrate but increased the maximum rate of transport about 3-fold. As inferred from the linearity of Scatchard plots, a single transport mechanism could account for the uptake of glucose under all conditions tested. As indicated by the transstimulation properties of the carrier, other neutral monohexoses, including D-galactose, D-mannose, D- and L-fucose were transported by this carrier. The transport rates and affinities of these sugars, measured by the use of their radiolabeled counterparts, were in the same range as those for D-glucose. Pentoses, sialic acid, and other acidic monosaccharides including their lactones, aminosugars, N-acetyl-hexosamines, and most L-stereoisomers, particularly those not present in mammalian tissues, were not transported by this carrier. Glucose uptake and transstimulation were inhibited by cytochalasin B and phloretin. The biochemical properties of this transporter differentiate it from other well-characterized lysosomal sugar carriers, including those for sialic acid and N-acetylhexosamines. The acidic pH optimum of this glucose transporter is a unique feature not shared with any other known glucose carrier and is consistent with its lysosomal origin.     

Biarylimidazoles as inhibitors of microsomal prostaglandin E2 synthase-1

Microsomal prostaglandin E(2) synthase (mPGES-1) represents a potential target for novel analgesic and anti-inflammatory agents. High-throughput screening identified several leads of mPGES-1 inhibitors which were further optimized for potency and selectivity. A series of inhibitors bearing a biaryl imidazole scaffold exhibits excellent inhibition of PGE(2) production in enzymatic and cell-based assays. The synthesis of these molecules and their activities will be discussed.