Reproducibility of Positive Results for the Detection of Serum Galactomannan by Platelia™ Aspergillus EIA

Galactomannan (GM) was recently included in consensus guidelines as an indirect mycological criterion for the diagnosis of invasive aspergillosis. Currently, there is an enzyme immunoassay available to detect GM in biological samples, the Platelia? Aspergillus EIA. In this study, the reproducibility of positive results obtained using this assay was evaluated using serum samples from neutropenic patients. A trend toward lower values was observed, and 55 %(27/49) of positive results were negative after retesting. A low reproducibility of positive results for the detection of GM in serum was observed.     

Seasonal response of fish assemblages to habitat fragmentation caused by an impoundment in a Neotropical river

Changes in fish assemblages between the zones above and below Funil dam in Southeastern Brazil were investigated to evaluate the possible impacts of this impoundment in two contrasting seasons: summer/wet and winter/dry. We expect differences in fish assemblage structure and in environmental conditions between seasons and between the reservoir and the zone downriver of the dam. A total of 3,579 individuals comprising 38 species, including six non-natives, were collected. As expected, the comparatively high habitat complexity and water flow regime of the downriver zone favored a richer and more abundant fish assemblage compared with the reservoir, especially in the wet season. In this period, water covers part of the riparian vegetation, increasing habitat availability and nutrient input. Additionally, the dam prevents upriver migration of rheophilics fish species such as the Characiformes Prochilodus lineatus and Leporinus copelandii, and the Siluriformes Pimelodus fur and Pimelodus maculatus, thus increasing shoals below the dam. Although the reservoir represents a simplified ecosystem highly influenced by non-native top predator species (e.g. the Perciformes Cichla kelberi and Plagioscion squamosissimus), seasonal processes (e.g. water level fluctuations and flood pulses) seem to play a role in structuring of the fish assemblage. Environmental variables, mainly turbidity, temperature, and conductivity were significantly associated to spatial-temporal patterns of fish assemblage. In this freshwater tropical reservoir, the spatial scale, rather than the seasonal changes in environmental variables, was the dominant factor structuring fish assemblage in the reservoir and in the zone downriver of the dam.     

92 Novel interpretation of the isotherms of multimodal ligands binding with DNA

The binding of ligands with DNA is a key moment in a whole range of cellular processes that provide not only the normal cell vital activity but also the development of some pathological processes. Depending on ligand type, structure of DNA adsorption centers, and physical–chemical conditions of the surrounding, the ligand may bind to DNA by several modes [1]. Particularly, adsorption isotherm of multimodal ligands binding to DNA in Scatchard’s coordinates has a concave shape with two brightly expressed linear areas in the region of small fillings. The analysis of such type of adsorption isotherm for determining of important binding parameters such as binding constant and number of adsorption centers (the part of DNA polymer with which one ligand molecule binds) presents difficulties. Practically in all cases, the analysis of such adsorption isotherm is carried out by linear parts of curves. Such analysis mode of experimental points is approximate method, since all registered of experimental points are roughly divided into two groups and they are treated by linear binding isotherm and therefore the binding parameters are determined. In the present work, the non-linear adsorption isotherm in Scatchard‘s coordinates is obtained which allowed, provided, the more precise treatment of all experimental points by unique curve which includes linear regions as well. Such mode of treatment of experimental points makes more precise the determination of not only binding constant and number of adsorption centers that correspond to the one ligand molecule binding, but also additional binding parameter – a proportion of adsorption centers of each binding to DNA type of multimodal ligand.     

93 Spectroscopic investigation of methylene blue binding to DNA

The interaction of methylene blue (MB) with DNA has been investigated by UV absorption spectra, Fluorescence spectra and UV-melting method. Analysis of the results of the melting experiments shows that melting temperature (T _m) of the complexes increases with the [total ligand]: DNA ratio (r) at two concentrations of Na⁺ (2?mM Na⁺ and 20?mM Na⁺) providing support for conclusion that MB is a stabilizer of DNA helix structure. By contrast, the shapes of dependences of width of transition (ΔT) on r at low and high [Na⁺] are different which points to the existence of different types of binding modes of MB with DNA. UV-spectroscopy experiments and fluorescence spectra indicated that the binding modes of MB with DNA depended on r. At high r (r?>?0.25), remarkable hypochromic effect with no shift of λ _max in the absorption spectra of MB was observed. The fluorescence of MB was quenched which indicated that MB was bound to phosphate groups of DNA by electrostatic interaction. At low r ratios (r?<?0.2), the absorption spectra of MB upon increasing the concentration of DNA showed gradually decrease in the peak intensities with a red shift. This phenomenon is usually associated with molecular intercalation into the base stack of the ds-DNA. Using the Scatchard’s model, the complex formation constants for MB with DNA were determined: the binding constant K?≈?6.5?×?10⁵ and binding site size n?≈?4. Obtained data are not typical for intercalation model of ligands to DNA. Moreover, comparison between these data and our early experimental results of interaction of ethidium bromide with DNA made it possible to suggest that this binding type of MB is, more probably, semi-intercalation mode (Vardevanyan et al., 2003). This conclusion is in accordance with the analysis of the model structures of MB–DNA complexes which clearly shows the importance of solvent contributions in suggested structural form (Tong et al., 2010).     

Circadian Pattern of Wheel‐Running Activity of a South American Subterranean Rodent (Ctenomys cf knightii)

Circadian rhythms are regarded as essentially ubiquitous features of animal behavior and are thought to confer important adaptive advantages. However, although circadian systems of rodents have been among the most extensively studied, most comparative biology is restricted to a few related species. In this study, the circadian organization of locomotor activity was studied in the subterranean, solitary north Argentinean rodent, Ctenomys knightii. The genus, Ctenomys, commonly known as Tuco‐tucos, comprises more than 50 known species over a range that extends from 12°S latitude into Patagonia, and includes at least one social species. The genus, therefore, is ideal for comparative and ecological studies of circadian rhythms. Ctenomys knightii is the first of these to be studied for its circadian behavior. All animals were wild caught but adapted quickly to laboratory conditions, with clear and precise activity‐rest rhythms in a light‐dark (LD) cycle and strongly nocturnal wheel running behavior. In constant dark (DD), the rhythm expression persisted with free‐running periods always longer than 24 h. Upon reinstatement of the LD cycle, rhythms resynchronized rapidly with large phase advances in 7/8 animals. In constant light (LL), six animals had free‐running periods shorter than in DD, and 4/8 showed evidence of “splitting.” We conclude that under laboratory conditions, in wheel‐running cages, this species shows a clear nocturnal rhythmic organization controlled by an endogenous circadian oscillator that is entrained to 24 h LD cycles, predominantly by light‐induced advances, and shows the same interindividual variable responses to constant light as reported in other non‐subterranean species. These data are the first step toward understanding the chronobiology of the largest genus of subterranean rodents.     

Synthesis,angiopreventive activity,and in vivo tumor inhibition of novel benzophenone–benzimidazole analogs

Aim

The development of anticancer drugs with specific targets is of prime importance in modern biology. This study investigates the angiopreventive and in vivo tumor inhibition activities of novel synthetic benzophenone–benzimidazole analogs.

Main methods

The multistep synthesis of novel benzophenone–benzimidazole analogs (8a–n) allowing substitution with methoxy, methyl and halogen groups at different positions on the identical chemical backbone and the variations in the number of substituents were synthesized and characterized. The newly synthesized compounds were further evaluated for cytotoxic and antiproliferative effects against Ehrlich ascites carcinoma (EAC) cells. The potent lead compounds were further assessed for antiangiogenic effects in a CAM model and a tumor-induced vasculature in vivo model. The effect of angioprevention on tumor growth was verified in a mouse model.

Key findings

The cytotoxicity studies revealed that compounds 8f and 8n are strongly cytotoxic. Analyzing the structure–activity relationship, we found that an increase in the number of methyl groups in addition to methoxy substitution at the para position of the benzoyl ring in compound 8n resulted in higher potency compared to 8f. Furthermore, neovessel formation in in vivo systems, such as the chorioallantoic membrane (CAM) and tumor-induced mice peritoneum models, was significantly suppressed and reflected the tumor inhibition observed in mice.

Significance

These results suggest the potential clinical application of compound 8n as an antiangiogenic drug for cancer therapy.     

High diversity of pipistrelloid bats (Vespertilionidae: Hypsugo,Neoromicia, and Pipistrellus) in a West African rainforest with the description of a new species

The pipistrelloid bats (genera Hypsugo, Neoromicia, and Pipistrellus) of Africa have been poorly studied, partly as a result of problems associated with species identification. This paper examines the diversity of pipistrelloid bats from Mount Nimba, a biodiversity hotspot in the Upper Guinean rainforest zone. Traditional morphometrics, the structure of the baculum, and sequences of the cytochrome oxidase subunit I (COI) gene were used to identify taxa. Species richness was exceptionally high and included at least ten taxa identifiable on molecular grounds. Of these, existing names could be assigned to six taxa. A seventh taxon was described as a species new to science, Neoromicia roseveari sp. nov. , and was distinguished on molecular grounds, craniodental morphology, and baculum structure. The remaining taxa may refer to as‐yet undescribed species but we lacked sufficient material to formally describe them here. The high species richness of pipistrelloid bats on Mount Nimba may be associated with the transition zone from lowland rainforest to moist savannah. © 2013 The Linnean Society of London     

History textbooks,racism and the critique of Eurocentrism: beyond rectification or compensation

This article is based on the theoretical framework developed within a research project on the construction of Eurocentrism and, more specifically, on the analysis of Portuguese history textbooks. We propose that the textbooks’ master narrative constitutes a power-evasive discourse on history, which naturalizes core processes such as colonialism, slavery and racism. Showing the limits of an approach that merely proposes the compensation or rectification of (mis)representations, we argue for the need to unbind the debate on Eurocentrism from a perspective that fails to make problematic the ‘very idea of Europe’. Accordingly, our analysis of Portuguese history textbooks focuses on three core narrative devices: (1) the chronopolitics of representation; (2) the paradigm of the (democratic) national state; and (3) the definitive bond between concepts and historical processes.     

Participation of the Cytoskeletal and Lysosomal Compartments in Campylobacter jejuni Invasion of Caco-2 cells, the Cellular Response by Morphometric Analysis and the Presence of Cytokine and Chemokine Transcripts

This study aimed to evaluate the participation of actin and tubulin in the process of internalisation, the interaction of bacterial phagosomes with lysosomes, the morphometric changes and the expression of inflammatory cytokines in Caco-2 cells infected with Campylobacter jejuni. Both actin and tubulin participated in the process of internalisation. Inside the cells, lysosomes fuse with phagosomes, which may lead to bacterial death because after 2 h, the bacteria were not detected by Transmission electron microscopy (TEM). There is increased expression of TGF-β3 during the early stages, and IL-8 was expressed after 60 min p.i. This work showed that C. jejuni invades and causes major morphometric changes in epithelial cells. In response, the cells increase their expression of cytokines that can lead to inflammation. The mechanisms of invasion are dependent on actin and tubulin, and once internalised, lysosomes fuse with phagosomes.     

Water deficit and recovery response of Medicago truncatula plants expressing the ELIP-like DSP22

In this article, we present the response of Medicago truncatula Gaert. cv. Jemalong plants expressing constitutively the Dsp22 gene from Craterostigma plantagineum to water stress and rehydration. The Dsp22 gene encodes an ELIP-like protein thought to protect the chloroplast against photooxidative damage during the dehydration and rehydration. The Dsp22 transgenic homozygous M. truncatula plants showed higher amount of chlorophyll (Chl), lower Chl a/Chl b ratio and higher actual efficiency of energy conversion in photosystem 2 (Φ_PSII) after rehydration, when compared to the wild type. The combined data from the Chl a fluorescence analysis, pigment quantification and biomass accumulation showed that transgenic M. truncatula plants are able to recover from water deprivation better than wild type plants.