Spray Nozzles,Pressures, Additives and Stirring Time on Viability and Pathogenicity of Entomopathogenic Nematodes (Nematoda: Rhabditida) for Greenhouses

The objective of this study was to evaluate different strategies for the application of entomopathogenic nematodes (EPN). Three different models of spray nozzles with air induction (AI 11003, TTI 11003 and AD-IA 11004), three spray pressures (207, 413 and 720 kPa), four different additives for tank mixtures (cane molasses, mineral oil, vegetable oil and glycerin) and the influence of tank mixture stirring time were all evaluated for their effect on EPN (Steinernema feltiae) viability and pathogenicity. The different nozzles, at pressures of up to 620 kPa, were found to be compatible with S. feltiae. Vegetable oil, mineral oil and molasses were found to be compatible adjuvants for S. feltiae, and stirring in a motorized backpack sprayer for 30 minutes did not impact the viability or pathogenicity of this nematode. Appropriate techniques for the application of nematodes with backpack sprayers are discussed.     

Synthesis and biological evaluation against Leishmania amazonensis of a series of alkyl-substituted benzophenones

Nine O-alkyl and O-prenyl derivatives were synthesized from commercial 2,4-dihydroxybenzophenone, 4,e4,4′-dihydroxybenzophenone and were evaluated for their leishmanicidal activity against promastigote forms of Leishmania amazonensis, as well their toxicity in murine macrophages. All derivatives exhibited better biological activity than their hydroxylated benzophenones precursors, and new compound LFQM-123 (3c) was 250-fold more active than its precursor 4,4′-dihydroxybenzophenone (3). Moreover, some of the results were comparable to the standard drug Amphotericin B, suggesting that the increase in lipophilicity could facilitate protozoa membrane permeation. In this study we confirmed that benzophenone derivatives exhibit leishmanicidal properties, with relatively low toxicity, and thus could be exploited as promise prototypes for the design and development of new drug for the treatment of leishmaniasis.     

Reply to Manger’s Commentary on “A quantitative test of the thermogenesis hypothesis of cetacean brain evolution,using phylogenetic comparative methods”

In his Commentary (Manger PR. 2009. Subglacial cetaceans and other mathematical mysteries: a Commentary on “A quantitative test of the thermogenesis hypothesis of cetacean brain evolution, using phylogenetic comparative methods” by C. Maximino. Mar Fresh Behav Physiol. 42: 359–362) on my paper (Maximino C. 2009. A quantitative test of the thermogenesis hypothesis of cetacean brain evolution, using phylogenetic comparative methods. Mar Freshwater Behav Physiol. 42:1–17), Dr Paul Manger noted four errors in the quantitative analysis of the relationship between cetacean encephalization quotients (EQs) and water temperatures, which I suggested was a test of his thermogenesis hypothesis (Manger PR. 2006 Manger, PR. 2006. An examination of cetacean brain structure with a novel hypothesis correlating thermogenesis to the evolution of a big brain. Biol Rev Camb Philos Soc, 81: 293–338.  [Google Scholar]. An examination of cetacean brain structure with a novel hypothesis correlating thermogenesis to the evolution of a big brain. Biol Rev Camb Philos Soc. 81:293–338). These referred to incorrect raw data on water temperatures for two species, odd use of midpoint temperatures as independent variable, lack of inclusion of data on Mysticeti and the use of a differently derived EQ and midpoints instead of the EQs proposed by Manger and temperature ranges; Dr Manger proposed that these errors invalidate the analysis, with special emphasis in an observation that, since my paper did not address the relationship between EQs and temperature range, it did not actually test the thermogenesis hypothesis. In this Reply, I apologize for the mistakes which were made, and show that re-analysis using all the proposed alterations do not qualitatively or quantitatively alter the final result. I also argue that the relationship between phylogenetically correct EQs and midpoint temperatures is a better test of the thermogenesis hypothesis than the relationship between non-phylogenetic EQs and temperature ranges.     

Study of the antidiabetic capacity of the VO(dmpp)2 complex

In this work we report biochemical ex vivo studies with a vanadium compound containing a pyridinone ligand, the bis(1,2-dimethyl-3-hydroxy-4-pyridinonate)oxovanadium (IV), V^IVO(dmpp)₂, which has shown to have promising antidiabetic activity. The experiments were carried out on primary adipocytes of 6-8 week old Wistar rats. Insulin-stimulated glucose uptake studies were performed using a radioactive assay by measuring the (U)-¹⁴C-glucose taken up by the isolated adipocytes for 30 min. Adipocytes were incubated with and without insulin and in the presence and absence of different concentrations of V^IVO(dmpp)₂ (100-500 μM) for 45 min. We observed that in a nontoxic concentration, as demonstrated by the Alamar Blue test, V^IVO(dmpp)₂ significantly increases glucose uptake, in the absence of insulin, by 5-folds higher than basal, and it has a significant inhibitory effect of 78% on free fatty acid release in isolated adipocytes from normal rats. We also demonstrated that it promotes the phosphorylation of Akt1, a key protein in the insulin signaling cascade. These results were compared with those obtained with another vanadium compound reported in the literature, with a similar structure, the bis(maltolato)oxovanadium (IV) (BMOV), which is now in clinical trials. Our ex vivo results clearly indicate that V^IVO(dmpp)₂ is a good candidate to be a promising drug for the treatment of diabetes and other metabolic disorders.     

Echinococcus granulosus antigen B structure: subunit composition and oligomeric states

Background

Antigen B (AgB) is the major protein secreted by the Echinococcus granulosus metacestode and is involved in key host-parasite interactions during infection. The full comprehension of AgB functions depends on the elucidation of several structural aspects that remain unknown, such as its subunit composition and oligomeric states.

Methodology/Principal Findings

The subunit composition of E. granulosus AgB oligomers from individual bovine and human cysts was assessed by mass spectrometry associated with electrophoretic analysis. AgB8/1, AgB8/2, AgB8/3 and AgB8/4 subunits were identified in all samples analyzed, and an AgB8/2 variant (AgB8/2v8) was found in one bovine sample. The exponentially modified protein abundance index (emPAI) was used to estimate the relative abundance of the AgB subunits, revealing that AgB8/1 subunit was relatively overrepresented in all samples. The abundance of AgB8/3 subunit varied between bovine and human cysts. The oligomeric states formed by E. granulosus AgB and recombinant subunits available, rAgB8/1, rAgB8/2 and rAgB8/3, were characterized by native PAGE, light scattering and microscopy. Recombinant subunits showed markedly distinct oligomerization behaviors, forming oligomers with a maximum size relation of rAgB8/3>rAgB8/2>rAgB8/1. Moreover, the oligomeric states formed by rAgB8/3 subunit were more similar to those observed for AgB purified from hydatid fluid. Pressure-induced dissociation experiments demonstrated that the molecular assemblies formed by the more aggregative subunits, rAgB8/2 and rAgB8/3, also display higher structural stability.

Conclusions/Significance

For the first time, AgB subunit composition was analyzed in samples from single hydatid cysts, revealing qualitative and quantitative differences between samples. We showed that AgB oligomers are formed by different subunits, which have distinct abundances and oligomerization properties. Overall, our findings have significantly contributed to increase the current knowledge on AgB expression and structure, highlighting issues that may help to understand the parasite adaptive response during chronic infection.     

Diversity and identification of methanogenic archaea and sulphate-reducing bacteria in sediments from a pristine tropical mangrove

Mangrove sediments are anaerobic ecosystems rich in organic matter. This environment is optimal for anaerobic microorganisms, such as sulphate-reducing bacteria and methanogenic archaea, which are responsible for nutrient cycling. In this study, the diversity of these two functional guilds was evaluated in a pristine mangrove forest using denaturing gradient gel electrophoresis (DGGE) and clone library sequencing in a 50 cm vertical profile sampled every 5.0 cm. DGGE profiles indicated that both groups presented higher richness in shallow samples (0–30 cm) with a steep decrease in richness beyond that depth. According to redundancy analysis, this alteration significantly correlated with a decrease in the amount of organic matter. Clone library sequencing indicated that depth had a strong effect on the selection of dissimilatory sulphate reductase (dsrB) operational taxonomic units (OTUs), as indicated by the small number of shared OTUs found in shallow (0.0 cm) and deep (40.0 cm) libraries. On the other hand, methyl coenzyme-M reductase (mcrA) libraries indicated that most of the OTUs found in the shallow library were present in the deep library. These results show that these two guilds co-exist in these mangrove sediments and indicate important roles for these organisms in nutrient cycling within this ecosystem.     

Biogeography and evolution of Dolichandra (Bignonieae,Bignoniaceae)

Little information on evolutionary relationships of Neotropical organisms or on the factors that have shaped the diversity currently encountered in this region is available. However, it is clear that biotic interactions and abiotic aspects have played important roles for species diversification in the region. This study focuses on Dolichandra (Bignonieae, Bignoniaceae), a clade of Neotropical lianas that is distributed broadly across different habitats and with diverse pollination and dispersal systems. We used sequences from two plastid DNA markers (ndhF and rpl32‐trnL) and one nuclear gene (PepC) to infer phylogenetic relationships in Dolichandra using parsimony and Bayesian approaches. We then used this phylogenetic framework as basis to study the biogeographic history, reconstruct the evolution of morphological characters and test the impact of morphology and environment on the diversification of the genus. More specifically, we: (1) time‐calibrate the phylogenetic tree of Dolichandra; (2) estimate the ancestral areas of the various lineages; (3) estimate the ancestral states of discrete and continuous morphological traits; (4) test for phylogenetic signal in environmental and phenotypic data; and (5) test whether morphological characters and/or niche evolution are correlated with cladogenesis. All Dolichandra spp. are monophyletic in the combined molecular phylogeny; relationships among species are generally well resolved, although poorly supported in some instances. The genus is inferred to have originated 36.43–26.23 Mya, possibly in eastern South America. Ancestral state reconstructions of continuous and discrete floral characters inferred a mixed morphology as the ancestral condition for the group. Phylogenetic signal differed between perianth and sexual whorls and gradual evolution was recovered for all traits except style length and anther length. Environmental variables showed no phylogenetic signal and a pattern of variation that was not correlated with branch length, suggesting that environmental transitions were concomitant with speciation. Dispersal is inferred to be the main driver of the differential distribution observed among species. In addition, climatic preferences and floral characters seem to have been important reproductive barriers in Dolichandra. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 403–420.