Parrot claylick distribution in South America: do patterns of “where” help answer the question “why”?

Geophagy is well known among some Neotropical parrots. The clay apparently adsorbs dietary toxins and/or provides supplemental nutrients. We used location data and 23 environmental layers to develop a predictive model of claylick distribution using Maxent software. We related species characteristics to claylick use and examined how parrot assemblages using claylicks changed with distance from the centre of claylick distribution. Fifty‐two parrot claylicks were reported from an area of ca 4 million km² but over 50% were restricted to a 35 000 km² region of southeast Peru and northern Bolivia. Claylicks were strongly associated with moist forest on younger (<65 millions of yr) geological formations and exposed river banks. The predictive model of claylick distribution matched our reported range well, with precipitation of warmest quarter, land cover, temperature seasonality, and distance from the ocean being most important predictors of claylick presence. Twenty‐six of the region's 46 parrot species visited claylicks. Species differed greatly in their lick use, but body size, dietary breadth, abundance and other traits were poor predictors of lick use. We are confident that our survey identified the distribution of major parrot claylicks in South America, although less conspicuous parrot geophagy may occur elsewhere. We suggest that claylick distribution reflects both underlying geology (allowing claylick formation in only some regions) and the physiological need for geophagy among parrots in different parts of the continent. Data on the latter are inconclusive, but we argue that parrot claylick distribution supports the contention that geophagy is related more to sodium deficiencies than to protection from dietary toxins.     

A plasma global metabolic profiling approach applied to an exercise study monitoring the effects of glucose, galactose and fructose drinks during post-exercise recovery

A global metabolic profiling methodology based on gas chromatography coupled to time-of-flight mass spectrometry (GC-TOFMS) for human plasma was applied to a human exercise study focused on the effects of beverages containing glucose, galactose, or fructose taken after exercise and throughout a recovery period of 6 h and 45 min. One group of 10 well trained male cyclists performed 3 experimental sessions on separate days (randomized, single center). After performing a standardized depletion protocol on a bicycle, subjects consumed one of three different beverages: maltodextrin (MD)+glucose (2:1 ratio), MD+galactose (2:1), and MD+fructose (2:1), consumed at an average of ～1.25 g of carbohydrate (CHO) ingested per minute. Blood was taken straight after exercise and every 45 min within the recovery phase. With the resulting blood plasma, insulin, free fatty acid (FFA) profile, glucose, and GC-TOFMS global metabolic profiling measurements were performed. The resulting profiling data was able to match the results obtained from the other clinical measurements with the addition of being able to follow many different metabolites throughout the recovery period. The data quality was assessed, with all the labelled internal standards yielding values of <15% CV for all samples (n=335), apart from the labelled sucrose which gave a value of 15.19%. Differences between recovery treatments including the appearance of galactonic acid from the galactose based beverage were also highlighted.     

Relative actin nucleation promotion efficiency by WASP and WAVE proteins in endothelial cells

The mammalian genome encodes multiple Wiskott-Aldrich syndrome protein (WASP)/WASP-family Verprolin homologous (WAVE) proteins. Members of this family interact with the actin related protein (Arp) 2/3 complex to promote growth of a branched actin network near the plasma membrane or the surface of moving cargos. Arp2/3 mediated branching can further lead to formation of comet tails (actin rockets). Despite their similar domain structure, different WASP/WAVE family members fulfill unique functions that depend on their subcellular location and activity levels. We measured the relative efficiency of actin nucleation promotion of full-length WASP/WAVE proteins in a cytoplasmic extract from primary human umbilical vein endothelial cells (HUVEC). In this assay WAVE2 and WAVE3 complexes showed higher nucleation efficiency than WAVE1 and N-WASP, indicating distinct cellular controls for different family members. Previously, WASP and N-WASP were the only members that were known to stimulate comet formation. We observed that in addition to N-WASP, WAVE3 also induced short actin tails, and the other WAVEs induced formation of asymmetric actin shells. Differences in shape and structure of actin-based growth may reflect varying ability of WASP/WAVE proteins to break symmetry of the actin shell, possibly by differential recruitment of actin bundling or severing (pruning or debranching) factors.     

Physicochemical Characterization of Berberine Chloride: A Perspective in the Development of a Solution Dosage Form for Oral Delivery

The objective of the present research was to evaluate the physicochemical characteristics of berberine chloride and to assess the complexation of drug with 2-hydroxypropyl-β-cyclodextrin (HPβCD), a first step towards solution dosage form development. The parameters such as log P value were determined experimentally and compared with predicted values. The pH-dependent aqueous solubility and stability were investigated following standard protocols at 25°C and 37°C. Drug solubility enhancement was attempted utilizing both surfactants and cyclodextrins (CDs), and the drug/CD complexation was studied employing various techniques such as differential scanning calorimetry, Fourier transform infrared, nuclear magnetic resonance, and scanning electron microscopy. The experimental log P value suggested that the compound is fairly hydrophilic. Berberine chloride was found to be very stable up to 6 months at all pH and temperature conditions tested. Aqueous solubility of the drug was temperature dependent and exhibited highest solubility of 4.05 ± 0.09 mM in phosphate buffer (pH 7.0) at 25°C, demonstrating the effect of buffer salts on drug solubility. Decreased drug solubility was observed with increasing concentrations of ionic surfactants such as sodium lauryl sulfate and cetyl trimethyl ammonium bromide. Phase solubility studies demonstrated the formation of berberine chloride–HPβCD inclusion complex with 1:1 stoichiometry, and the aqueous solubility of the drug improved almost 4.5-fold in the presence of 20% HPβCD. The complexation efficiency values indicated that the drug has at least threefold greater affinity for hydroxypropyl-β-CD compared to randomly methylated-β-CD. The characterization techniques confirmed inclusion complex formation between berberine chloride and HPβCD and demonstrated the feasibility of developing an oral solution dosage form of the drug.KEY WORDS: berberine chloride, complexation, cyclodextrin, solubility, surfactants     

IPS-1 Is Essential for the Control of West Nile Virus Infection and Immunity

The innate immune response is essential for controlling West Nile virus (WNV) infection but how this response is propagated and regulates adaptive immunity in vivo are not defined. Herein, we show that IPS-1, the central adaptor protein to RIG-I-like receptor (RLR) signaling, is essential for triggering of innate immunity and for effective development and regulation of adaptive immunity against pathogenic WNV. IPS-1^−/− mice exhibited increased susceptibility to WNV infection marked by enhanced viral replication and dissemination with early viral entry into the CNS. Infection of cultured bone-marrow (BM) derived dendritic cells (DCs), macrophages (Macs), and primary cortical neurons showed that the IPS-1-dependent RLR signaling was essential for triggering IFN defenses and controlling virus replication in these key target cells of infection. Intriguingly, infected IPS-1^−/− mice displayed uncontrolled inflammation that included elevated systemic type I IFN, proinflammatory cytokine and chemokine responses, increased numbers of inflammatory DCs, enhanced humoral responses marked by complete loss of virus neutralization activity, and increased numbers of virus-specific CD8+ T cells and non-specific immune cell proliferation in the periphery and in the CNS. This uncontrolled inflammatory response was associated with a lack of regulatory T cell expansion that normally occurs during acute WNV infection. Thus, the enhanced inflammatory response in the absence of IPS-1 was coupled with a failure to protect against WNV infection. Our data define an innate/adaptive immune interface mediated through IPS-1-dependent RLR signaling that regulates the quantity, quality, and balance of the immune response to WNV infection.     

Current status of regulating biotechnology-derived animals in Canada: animal health and food safety considerations

Development of an effective regulatory system for genetically engineered animals and their products has been the subject of increasing discussion among researchers, industry and policy developers, as well as the public. Since transgenesis and cloning are relatively new scientific techniques, transgenic animals are 'novel' organisms for which there is limited information. The issues associated with the regulation of transgenic animals pertain to environmental impact, human food safety, animal health and welfare, trade and ethics. It is a challenge for the developers to prove the safety of the products of biotechnology-derived animals and also for regulators to regulate this increasingly powerful technology with limited background information. In principle, an effective regulatory sieve should permit safe products while forming a formidable barrier for those posing an unacceptable risk. Regulatory initiatives for biotechnology-derived animals and their products should be able to ensure high standards for human and animal health, a sound scientific basis for evaluation; transparency and public involvement, and maintenance of genetic diversity. This review proposes a regulatory regime that is based on scientific risk based assessment and approval of products or by-products of biotechnology-derived animals and its application in context to Canadian regulations.     

Functionalization of pine needles by carboxymethylation and network formation for use as supports in the adsorption of Cr

Pine needles and their carboxymethyl forms were functionalized by network formation with 2-acrylamido-2-methylpropanesulphonic acid (AAmPSA) in the presence of N,N-methylene bisacrylamide. N-Tetramethylethylene diamine and ammonium persulfate were used as accelerator-initiator systems to prepare these hydrogels. The hydrogels were characterized by FTIR, SEM, and nitrogen analysis and for water uptake capacities before and after metal ion sorption with a view to evaluating their use in the removal of toxic ionic species from waste water. A detailed study of Cr⁶⁺ adsorption was carried out as a function of time, temperature, pH, and ionic strength. The thermodynamic parameters of adsorption such as ΔH⁰, ΔS⁰, and ΔG⁰ have been evaluated to understand the underlying mechanism of adsorption. In order to understand their reusability in possible technological applications, biodegradability of these hydrogels and their precursors was studied.