Field and laboratory studies to assess the effects of Vertimec (R) 18EC on Daphnia similis

The present study aimed to evaluate the interactions of the pesticide Vertimec (R) 18EC in aquatic ecosystems. In this respect, soil plots were contaminated with Vertimec (R) 18EC at the concentration indicated for strawberry crops (0.125 L of solution m(-2)). After the contamination, torrential rainfall was simulated and the surface runoff was collected and transferred to mesocosm tanks in five treatments, run in triplicate: (1) control-C; (2) runoff from an uncontaminated plot-UR; (3) runoff from the plot contaminated with Vertimec (R) 18EC-CR; (4) direct application of Vertimec (R) 18EC in the water-V and (5) water samples gathered randomly to verify whether there was contamination between the mesocosms-RS. Water samples from these tanks were also submitted to ecotoxicological tests with Daphnia similis and analyses to evaluate the limnological characteristics, in five collection periods over 10 days (240 h). Physical and chemical differences were observed in the water samples, mainly related to increased turbidity, suspended solids and nutrients (nitrogen and phosphate forms). Acute toxicity was observed for the direct application treatment for the entire experimental period, and in some periods for the CR treatment (from 48 h to 168 h). The results obtained suggest that the pesticide did not fully degrade during the study period (10 days) in the direct application treatment, demonstrating that the presence of other substances in the commercial formulation contribute to the maintenance of toxicity. This represents a potential risk for aquatic ecosystems in areas adjacent to where the chemical is applied. (C) 2011 Elsevier Inc. All rights reserved.

Quantitative proteomic analysis and functional studies reveal that nucleophosmin is involved in cell death in glioblastoma cell line transfected with siRNA

Previously, we reported that nucleophosmin (NPM) was increased in glioblastoma multiforme (GBM). NPM is a phosphoprotein related to apoptosis, ribosome biogenesis, mitosis, and DNA repair, but details about its function remain unclear. We treated U87MG and A172 cells with small interference RNA (siRNA) and obtained a reduction of 80% in NPM1 expression. Knockdown at the protein level was evident after the 4th day and was maintained until the 7th day of transfection that was investigated by quantitative proteomic analysis using isobaric tags. The comparison of proteomic analysis of NPM1-siRNA against controls allowed the identification of 14 proteins, two proteins showed increase and 12 presented a reduction of expression levels. Gene ontology assigned most of the hypoexpressed proteins to apoptosis regulation, including GRP78. NPM1 silencing did not impair cell proliferation until the 7th day after transfection, but sensitized U87MG cells to temozolomide (TMZ), culminating with an increase in cell death and provoking at a later period a reduction of colony formation. In a large data set of GBM patients, both GRP78 and NPM1 genes were upregulated and presented a tendency to shorter overall survival time. In conclusion, NPM proved to participate in the apoptotic process, sensitizing TMZ-treated U87MG and A172 cells to cell death, and in association with upregulation of GRP78 may be helpful as a predictive factor of poor prognosis in GBM patients.

Resurrection of the genus Licornia for Scrupocellaria jolloisii (Bryozoa) and related species, with documentation of L. jolloisii as a non-indigenous species in the western Atlantic

Recent studies of the large cheilostome bryozoan genus Scrupocellaria have shown a greater degree of taxonomically informative morphological variation in zooids, opesia, and polymorphic structures than previously recognized. Only one subgenus has been named within the genus, Retiscrupocellaria d'Hondt, 1988, erected for Scrupocellaria jolloisii. In this work we further analyse S. jolloisii and its related species, resurrecting an earlier genus name, Licornia van Beneden, 1850 for Licornia jolloisii, and nine relatives, L. annectens, L. cervicornis, L. cyclostoma, L. diadema, L. ferox, L. gaspari, L. longispinosa, L. macropora, and L. prolata. Licornia jolloisii was originally described from the Red Sea, and most species of the genus occur in the Indo-Pacific region. The species, however, has now been found in the Western Atlantic, in the Florida Keys, US, and in Bahia de Todos Santos, Brazil.

Recent benthic foraminiferal distribution and related environmental factors in Ezcurra Inlet, King George Island, Antarctica

This investigation attempts to determine which environmental parameters of the bottom water and sediment control recent foraminifera fauna at Ezcurra Inlet (King George Island, Antarctica), using data collected during four summers (2002/03, 2003/04, 2004/05 and 2006/07). The study revealed that Ezcurra Inlet contain typical Antarctic foraminifera fauna with three distinct assemblages and few differences in environmental parameters. The species Bolivina pseudopunctata, Fursenkoina fusiformis, Portatrochammina antarctica, and Adercotryma glomerata were abundant in the samples. An elevated abundance, richness and diversity were common at the entrance of the inlet at depths greater than 55 m, where the inlet was characterized by low temperatures and muddy sand. In the inner part of the inlet (depth 30-55 m), richness and diversity were low and the most significant species were Cassidulinoides parkerianus, C. porrectus, and Psammosphaera fusca. Shallow waters showed low values of richness and abundance and high temperatures coupled with coarser sediment. In areas with high suspended matter concentrations and pH values associated with low salinity the most representative species were Hippocrepinella hirudinea and Hemisphaerammina bradyi.

Functional and structural studies of the disulfide isomerase DsbC from the plant pathogen Xylella fastidiosa reveals a redox-dependent oligomeric modulation in vitro

Xylella fastidiosa is a Gram-negative bacterium that grows as a biofilm inside the xylem vessels of susceptible plants and causes several economically relevant crop diseases. In the present study, we report the functional and low-resolution structural characterization of the X. fastidiosa disulfide isomerase DsbC (XfDsbC). DsbC is part of the disulfide bond reduction/isomerization pathway in the bacterial periplasm and plays an important role in oxidative protein folding. In the present study, we demonstrate the presence of XfDsbC during different stages of X. fastidiosa biofilm development. XfDsbC was not detected during X. fastidiosa planktonic growth; however, after administering a sublethal copper shock, we observed an overexpression of XfDsbC that also occurred during planktonic growth. These results suggest that X. fastidiosa can use XfDsbC in vivo under oxidative stress conditions similar to those induced by copper. In addition, using dynamic light scattering and small-angle X-ray scattering, we observed that the oligomeric state of XfDsbC in vitro may be dependent on the redox environment. Under reducing conditions, XfDsbC is present as a dimer, whereas a putative tetrameric form was observed under nonreducing conditions. Taken together, our findings demonstrate the overexpression of XfDsbC during biofilm formation and provide the first structural model of a bacterial disulfide isomerase in solution. Structured digital abstract XfDsbC and XfDsbC bind by x ray scattering (View Interaction: 1, 2) XfDsbC and XfDsbC bind by molecular sieving (View interaction) XfDsbC and XfDsbC bind by comigration in non denaturing gel electrophoresis (View interaction) XfDsbC and XfDsbC bind by cross-linking study (View Interaction: 1, 2) XfDsbC and XfDsbC bind by dynamic light scattering (View Interaction: 1, 2)

Kinetic and Thermodynamic Studies on the Adsorption of Reactive Red 239 by Carra Sawdust Treated with Formaldehyde

In this study, carra sawdust pre-treated with formaldehyde was used to adsorb reactive red 239 (RR239). The effects of several experimental conditions, including the concentration of dye, sorbent dosage, temperature, ionic strength, stirring speed and solution pH, on the kinetics of the adsorption process have been studied, and the experimental data were fitted to pseudo-second-order model. A study of the intra-particle diffusion model indicates that the mechanism of dye adsorption using carra sawdust is rather complex and is most likely a combination of external mass transfer and intra-particle diffusion. The experimental data obtained at equilibrium were analyzed using the Langmuir and Freundlich isotherm models, and the results indicated that at this concentration range, both models can be applied for obtaining the equilibrium parameters. The maximum dye uptake obtained at 298 K was found to be 15.1 mg g(-1). In contrast to the usual systems, the reactive dye studied in the present work is strongly attached to the sawdust even after several washes with water, allowing it to be discarded as a solid waste.

Gas-phase reactivity of protonated 2-oxazoline derivatives: mass spectrometry and computational studies

RATIONALE: Oxazolines have attracted the attention of researchers worldwide due to their versatility as carboxylic acid protecting groups, chiral auxiliaries, and ligands for asymmetric catalysis. Electrospray ionization tandem mass spectrometric (ESI-MS/MS) analysis of five 2-oxazoline derivatives has been conducted, in order to understand the influence of the side chain on the gas-phase dissociation of these protonated compounds under collision-induced dissociation (CID) conditions. METHODS: Mass spectrometric analyses were conducted in a quadrupole time-of-flight (Q-TOF) spectrometer fitted with electrospray ionization source. Protonation sites have been proposed on the basis of the gas-phase basicity, proton affinity, atomic charges, and a molecular electrostatic potential map obtained on the basis of the quantum chemistry calculations at the B3LYP/6-31 + G(d, p) and G2(MP2) levels. RESULTS: Analysis of the atomic charges, gas-phase basicity and proton affinities values indicates that the nitrogen atom is a possible proton acceptor site. On the basis of these results, two main fragmentation processes have been suggested: one taking place via neutral elimination of the oxazoline moiety (99 u) and another occurring by sequential elimination of neutral fragments with 72 u and 27 u. These processes should lead to formation of R+. CONCLUSIONS: The ESI-MS/MS experiments have shown that the side chain could affect the dissociation mechanism of protonated 2-oxazoline derivatives. For the compound that exhibits a hydroxyl at the lateral chain, water loss has been suggested to happen through an E2-type elimination, in an exothermic step. Copyright (C) 2012 John Wiley & Sons, Ltd.

Cyclopropane- and spirolimonoids and related compounds from Hortia oreadica

The dichloromethane extract from taproots of Hortia oreadica afforded six limonoids, these are 9,11-dehydro-12 alpha-acetoxyhortiolide A, hortiolide C, 11 alpha-acetoxy-15-deoxy-6-hydroxyhortiolide C, hortiolide D, hortiolide E, 12 beta-hydroxyhortiolide E, in addition to the known limonoid, guyanin. The dichloromethane extract from stems of H. oreadica also afforded two limonoids 9,11-dehydro12 alpha-hydroxyhortiolide A and 6-hydroxyhortiolide C. As a result of this study and literature data, Hortia has been shown to produce highly specialized limonoids that are similar to those from the Flindersia (Flindersioideae). The taxonomy of Hortia has been debatable, with most authors placing it in the Toddalioideae. Considering the complexity of the isolated limonoids, Hortia does not show any close affinity to the genera of Toddalioideae. That is, the limonoids appear to be of little value in resolving the taxonomic situation of Hortia. (C) 2012 Elsevier Ltd. All rights reserved.

Structural and kinetic studies of Schistosoma mansoni adenylate kinases

The human parasite Schistosoma mansoni is totally dependent on the purine salvage pathway in order to supply large quantities of purine precursors for its energy and DNA biosynthetic needs. Adenylate kinase (ADK) is responsible for the conversion of AMP (produced by the adenosine kinase reaction) into ADP, which is subsequently converted into ATP by nucleoside diphosphate kinase (NDPK). ADK and NDPK are the most active enzymes of the pathway, probably reflecting an evolutionary adaptation due to the intense use of the branch in which they participate. However, notwithstanding their importance very little information has been accumulated found regarding these enzymes. In this work two adenylate kinases from S. mansoni were cloned and heterologously expressed in Escherichia coil. The purified products were utilized in activity assays, and displayed kinetic parameters similar to the corresponding human orthologous proteins. The cytosolic S. mansoni ADK was crystallized and its structure solved allowing us to detect a difference in the nucleotide binding site when compared with the human ortholog. (C) 2012 Elsevier B.V. All rights reserved.

Carbon monoxide and related trace gases and aerosols over the Amazon Basin during the wet and dry seasons

We present the results of airborne measurements of carbon monoxide (CO) and aerosol particle number concentration (CN) made during the Balan double dagger o Atmosf,rico Regional de Carbono na Amazonia (BARCA) program. The primary goal of BARCA is to address the question of basin-scale sources and sinks of CO2 and other atmospheric carbon species, a central issue of the Large-scale Biosphere-Atmosphere (LBA) program. The experiment consisted of two aircraft campaigns during November-December 2008 (BARCA-A) and May-June 2009 (BARCA-B), which covered the altitude range from the surface up to about 4500 m, and spanned most of the Amazon Basin. Based on meteorological analysis and measurements of the tracer, SF6, we found that airmasses over the Amazon Basin during the late dry season (BARCA-A, November 2008) originated predominantly from the Southern Hemisphere, while during the late wet season (BARCA-B, May 2009) low-level airmasses were dominated by northern-hemispheric inflow and mid-tropospheric airmasses were of mixed origin. In BARCA-A we found strong influence of biomass burning emissions on the composition of the atmosphere over much of the Amazon Basin, with CO enhancements up to 300 ppb and CN concentrations approaching 10 000 cm(-3); the highest values were in the southern part of the Basin at altitudes of 1-3 km. The Delta CN/Delta CO ratios were diagnostic for biomass burning emissions, and were lower in aged than in fresh smoke. Fresh emissions indicated CO/CO2 and CN/CO emission ratios in good agreement with previous work, but our results also highlight the need to consider the residual smoldering combustion that takes place after the active flaming phase of deforestation fires. During the late wet season, in contrast, there was little evidence for a significant presence of biomass smoke. Low CN concentrations (300-500 cm(-3)) prevailed basinwide, and CO mixing ratios were enhanced by only similar to 10 ppb above the mixing line between Northern and Southern Hemisphere air. There was no detectable trend in CO with distance from the coast, but there was a small enhancement of CO in the boundary layer suggesting diffuse biogenic sources from photochemical degradation of biogenic volatile organic compounds or direct biological emission. Simulations of CO distributions during BARCA-A using a range of models yielded general agreement in spatial distribution and confirm the important contribution from biomass burning emissions, but the models evidence some systematic quantitative differences compared to observed CO concentrations. These mismatches appear to be related to problems with the accuracy of the global background fields, the role of vertical transport and biomass smoke injection height, the choice of model resolution, and reliability and temporal resolution of the emissions data base.

PHYTOCHEMICAL AND CHEMOSYSTEMATICS STUDIES OF Conchocarpus marginatus AND C. inopinatus (Rutaceae)

PHYTOCHEMICAL AND CHEMOSYSTEMATICS STUDIES OF Conchocarpus marginatus AND C. inopinatus (Rutaceae). Phytochemical studies of the leaves and stem have led to the identification of the known acridone alkaloids arborinine, methylarborinine, 1-hydroxy-3-methoxy-N-methyl acridone, xanthoxoline, 1,2,3,5-tetramethoxy-N-methylacridone, toddaliopsin C and the new seco acridone alkaloid inopinatin. The known quinoline alkaloids 2-phenyl-1-methyl-quinolin-4(1H)-one, 2-phenyl-1-methyl-7-methoxy-quinolin-4(1H)-one, dictamnine, and the coumarins scopoletin and marmesin were also isolated. The isolated compounds and the distribution of secondary metabolites, which are systematically important, obtained from literature, clearly confirmed that some species formerly described in the genera Angostura and Galipea in fact shall belong to the genus Conchocarpus.

Modeling the emergence of HIV-1 drug resistance resulting from antiretroviral therapy: Insights from theoretical and numerical studies

The use of antiretroviral therapy has proven to be remarkably effective in controlling the progression of human immunodeficiency virus (HIV) infection and prolonging patient's survival. Therapy however may fail and therefore these benefits can be compromised by the emergence of HIV strains that are resistant to the therapy. In view of these facts, the question of finding the reason for which drug-resistant strains emerge during therapy has become a worldwide problem of great interest. This paper presents a deterministic HIV-1 model to examine the mechanisms underlying the emergence of drug-resistance during therapy. The aim of this study is to determine whether, and how fast, antiretroviral therapy may determine the emergence of drug resistance by calculating the basic reproductive numbers. The existence, feasibility and local stability of the equilibriums are also analyzed. By performing numerical simulations we show that Hopf bifurcation may occur. The model suggests that the individuals with drug-resistant infection may play an important role in the epidemic of HIV. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Comparative Genome Analysis of Trichophyton rubrum and Related Dermatophytes Reveals Candidate Genes Involved in Infection

The major cause of athlete's foot is Trichophyton rubrum, a dermatophyte or fungal pathogen of human skin. To facilitate molecular analyses of the dermatophytes, we sequenced T. rubrum and four related species, Trichophyton tonsurans, Trichophyton equinum, Microsporum canis, and Microsporum gypseum. These species differ in host range, mating, and disease progression. The dermatophyte genomes are highly colinear yet contain gene family expansions not found in other human-associated fungi. Dermatophyte genomes are enriched for gene families containing the LysM domain, which binds chitin and potentially related carbohydrates. These LysM domains differ in sequence from those in other species in regions of the peptide that could affect substrate binding. The dermatophytes also encode novel sets of fungus-specific kinases with unknown specificity, including nonfunctional pseudokinases, which may inhibit phosphorylation by competing for kinase sites within substrates, acting as allosteric effectors, or acting as scaffolds for signaling. The dermatophytes are also enriched for a large number of enzymes that synthesize secondary metabolites, including dermatophyte-specific genes that could synthesize novel compounds. Finally, dermatophytes are enriched in several classes of proteases that are necessary for fungal growth and nutrient acquisition on keratinized tissues. Despite differences in mating ability, genes involved in mating and meiosis are conserved across species, suggesting the possibility of cryptic mating in species where it has not been previously detected. These genome analyses identify gene families that are important to our understanding of how dermatophytes cause chronic infections, how they interact with epithelial cells, and how they respond to the host immune response. IMPORTANCE Athlete's foot, jock itch, ringworm, and nail infections are common fungal infections, all caused by fungi known as dermatophytes (fungi that infect skin). This report presents the genome sequences of Trichophyton rubrum, the most frequent cause of athlete's foot, as well as four other common dermatophytes. Dermatophyte genomes are enriched for four gene classes that may contribute to the ability of these fungi to cause disease. These include (i) proteases secreted to degrade skin; (ii) kinases, including pseudokinases, that are involved in signaling necessary for adapting to skin; (iii) secondary metabolites, compounds that act as toxins or signals in the interactions between fungus and host; and (iv) a class of proteins (LysM) that appear to bind and mask cell wall components and carbohydrates, thus avoiding the host's immune response to the fungi. These genome sequences provide a strong foundation for future work in understanding how dermatophytes cause disease.

Microsurgical Anatomy of the Optic Radiation and Related Fibers in 3-Dimensional Images

BACKGROUND: The fiber dissection technique provides unique 3-dimensional anatomic knowledge of the white matter. OBJECTIVE: To examine the optic radiation anatomy and its important relationship with the temporal stem and to discuss its findings in relation to the approaches to temporal lobe lesions. METHODS: We studied 40 cerebral hemispheres of 20 brains that had been fixed in formalin solution for 40 days. After removal of the arachnoid membrane, the hemispheres were frozen, and the Klingler technique was used for dissection under magnification. Stereoscopic 3-dimensional images of the dissection were obtained for illustration. RESULTS: The optic radiations are located deep within the superior and middle temporal gyri, always above the inferior temporal sulcus. The mean distance between the cortical surface and the lateral edge of the optic radiation was 21 mm. Its fibers are divided into 3 bundles after their origin. The mean distance between the anterior tip of the temporal horn and the Meyer loop was 4.5 mm, between the temporal pole and the anterior border of the Meyer loop was 28.4 mm, and between the limen insulae and the Meyer loop was 10.7 mm. The mean distance between the lateral geniculate body and the lateral margin of the central bundle of the optic radiation was 17.4 mm. CONCLUSION: The white matter fiber dissection reveals the tridimensional intrinsic architecture of the brain, and its knowledge regarding the temporal lobe is particularly important for the neurosurgeon, mostly because of the complexity of the optic radiation and related fibers.

Three in one: fixing marine nematodes for ecological, molecular, and morphological studies

Multidisciplinary benthic studies are still hindered by the lack of a unique fixative that satisfactorily preserves morphology and DNA, and that is simultaneously adequate for ecological surveys. The objective of this study is to test the performance of five fixatives: formalin, ethanol, dimethylsulfoxide with EDTA and NaCl salts (DESS), methanol with acetic acid (METHAC), and ethanol with acetic acid (ETHAC), for the preservation of estuarine and exclusively marine nematode assemblages for morphological, molecular, and ecological studies. The presence of the stain rose bengal in each fixative was also evaluated in the yield of PCR reactions. For molecular analyses, one species of each habitat was considered. Results revealed that fixative performance for morphological studies is habitat-and species-dependent. For studies of estuarine sediment nematodes, we recommend the use of pure ethanol, because it caused little morphological distortion (<10% of the assemblage), preserved all the species for ecological studies, and yielded high quality DNA sequences. For studies of exclusively marine environments, METHAC or DESS are the most adequate. The first performed better for morphological and ecological surveys, whereas the second was more appropriate for molecular research. For ecological studies, DESS should be used in comparison with formalin, in order to cross check the results. Finally, staining of samples with rose bengal is not recommended, because it hindered DNA amplification regardless of the fixative used.