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.     

Development of a novel anti-biofilm peptide derived from profilin of Spodoptera frugiperda

Abstract

Candida yeast infections are the fourth leading cause of death worldwide. Peptides with antimicrobial activity are a promising alternative treatment for such infections. Here, the antifungal activity of a new antimicrobial peptide—PEP-IA18—was evaluated against Candida species. PEP-IA18 was designed from the primary sequence of profilin, a protein from Spodoptera frugiperda, and displayed potent activity against Candida albicans and Candida tropicalis, showing a minimum inhibitory concentration (MIC) of 2.5?µM. Furthermore, the mechanism of action of PEP-IA18 involved interaction with the cell membrane (ergosterol complexation). Treatment at MIC and/or 10?×?MIC significantly reduced biofilm formation and viability. PEP-IA18 showed low toxicity toward human fibroblasts and only revealed hemolytic activity at high concentrations. Thus, PEP-IA18 exhibited antifungal and anti-biofilm properties with potential applicability in the treatment of infections caused by Candida species.     

Pam3CSK4 adjuvant given intranasally boosts anti-Leishmania immunogenicity but not protective immune responses conferred by LaAg vaccine against visceral leishmaniasis

The use of adjuvants in vaccine formulations is a well-established practice to improve immunogenicity and protective immunity against diseases. Previously, we have demonstrated the feasibility of intranasal vaccination with the antigen of killed Leishmania amazonensis promastigotes (LaAg) against experimental leishmaniasis. In this work, we sought to optimize the immunogenic effect and protective immunity against murine visceral leishmaniasis conferred by intranasal delivery of LaAg in combination with a synthetic TLR1/TLR2 agonist (Pam3CSK4). Intranasal vaccination with LaAg/PAM did not show toxicity or adverse effects, induced the increase of delayed-type hypersensitivity response and the production of inflammatory cytokines after parasite antigen recall. However, mice vaccinated with LaAg/PAM and challenged with Leishmania infantum presented significant reduction of parasite burden in both liver and spleen, similar to those vaccinated with LaAg. Although LaAg/PAM intranasal vaccination had induced higher frequencies of specific CD4⁺ and CD8⁺ T cells and increased levels of IgG2a antibody isotype in serum, both LaAg and LaAg/PAM groups presented similar levels of IL-4 and IFN-y and decreased production of IL-10 when compared to controls. Our results provide the first evidence of the feasibility of intranasal immunization with antigens of killed Leishmania in association with a TLR agonist, which may be explored for developing an effective and alternative strategy for vaccination against visceral leishmaniasis.     

Low sodium isocyanurate concentrations as a substitute to medium autoclaving in plant tissue culture

Plant Cell, Tissue and Organ Culture (PCTOC) - An optimization for a medium sterilization method, capable of substituting autoclaving, was developed using low concentrations of sodium isocyanurate...     

Activity of sodium trimetaphosphate,associated or not with fluoride,on dual-species biofilms

Abstract

A response surface methodology was used to build a model to predict reductions in uropathogenic Escherichia coli biofilms in response to three compounds: cranberry extract [CB] at 3.0–9.0%, and caprylic acid [CAR] and thymol [TM] at 0.01%–0.05%. The predictive model for microbial reduction had a high regression coefficient (R²?=?0.9988), and the accuracy of the model was verified (R²?=?0.9527). Values of CAR, TM, and the quadratic term CAR² were the most significant (P?10 reduction) determined by ridge analysis were 8.3% CB +0.04% CAR +0.04% TM at 37?°C for 1?min. The model could be used to predict the most cost-efficient amounts of antimicrobial agents for anti-urinary tract infection products such as catheter lock solution and antimicrobial coatings for catheters.     

Immobilization and stabilization of a bimolecular aggregate of the lipase from Pseudomonas fluorescens by multipoint covalent attachment

The soluble lipase from Pseudomonas fluorescens (PFL) forms bimolecular aggregates in which the hydrophobic active centers of the enzyme monomers are in close contact. This bimolecular aggregate could be immobilized by multipoint covalent linkages on glyoxyl supports at pH 8.5. The monomer of PFL obtained by incubation of the soluble enzyme in the presence of detergent (0.5% TRITON X-100) could not be immobilized under these conditions. The bimolecular aggregate has two amino terminal residues in the same plane. A further incubation of the immobilized derivative under more alkaline conditions (e.g., pH 10.5) allows a further multipoint attachment of lysine (Lys) residues located in the same plane as the amino terminal residues. Monomeric PFL was immobilized at pH 10.5 in the presence of 0.5% TRITON X-100. The properties of both PFL derivatives were compared. In general, the bimolecular derivatives were more active, more selective and more stable both in water and in organic solvents than the monomolecular ones. The bimolecular derivative showed twice the activity and a much higher selectivity (100 versus 20) for the hydrolysis of R,S-2-hydroxy-4-phenylbutyric acid ethyl ester (HPBEt) in aqueous media at pH 5.0 compared to the monomeric derivative. In experiments measuring thermal inactivation at 75 °C, the bimolecular derivative was 5-fold more stable than the monomeric derivative (and 50-fold more stable than a one-point covalently immobilized PFL derivative), and it had a half-life greater than 4 h. In organic solvents (cyclohexane and tert-amyl alcohol), the bimolecular derivative was much more stable and more active than the monomeric derivative in catalyzing the transesterification of olive oil with benzyl alcohol.     

Inhibiting AKT Phosphorylation Employing Non-Cytotoxic Anthraquinones Ameliorates TH2 Mediated Allergic Airways Disease and Rhinovirus Exacerbation

Background

Severe asthma is associated with T helper (T_H) 2 and 17 cell activation, airway neutrophilia and phosphoinositide-3-kinase (PI3K) activation. Asthma exacerbations are commonly caused by rhinovirus (RV) and also associated with PI3K-driven inflammation. Anthraquinone derivatives have been shown to reduce PI3K-mediated AKT phosphorylation in-vitro.

Objective

To determine the anti-inflammatory potential of anthraquinones in-vivo.

Methods

BALB/c mice were sensitized and challenged with crude house dust mite extract to induce allergic airways disease and treated with mitoxantrone and a novel non-cytotoxic anthraquinone derivative. Allergic mice were also infected with RV1B to induce an exacerbation.

Results

Anthraquinone treatment reduced AKT phosphorylation, hypoxia-inducible factor-1α and vascular endothelial growth factor expression, and ameliorated allergen- and RV-induced airways hyprereactivity, neutrophilic and eosinophilic inflammation, cytokine/chemokine expression, mucus hypersecretion, and expression of T_H2 proteins in the airways. Anthraquinones also boosted type 1 interferon responses and limited RV replication in the lung.

Conclusion

Non-cytotoxic anthraquinone derivatives may be of therapeutic benefit for the treatment of severe and RV-induced asthma by blocking pro-inflammatory pathways regulated by PI3K/AKT.     

Comparative cytogenetics of three economically important Piper L. species from the Brazilian Amazon

The species Piper hispidinervum, Piper aduncum, and Piper affinis hispidinervum have essential oils with high levels of safrole, dillapiole, and sarisan, respectively. Safrole is important for pharmaceutical and chemical industries, while dillapiole and sarisan are promising compounds to control insects and fungi. These species are very similar morphologically and their taxonomy is controversial. Divergent hypotheses consider P. aduncum and P. hispidinervum either as a single species or as distinct taxa, while P. affinis hispidinervum is inferred to be a natural hybrid or a chemotype of P. hispidinervum. Delimiting the taxonomic boundaries would be helpful for germplasm conservation and breeding programs. This study aimed to undertake a detailed analysis of P. aduncum, P. hispidinervum, and P. affinis hispidinervum karyotype and rDNA sites. Genomic in situ hybridization (GISH) was used to establish genomic homology among species and to test the natural hybridization hypothesis for origin of P. affinis hispidinervum. Karyotype traits were similar for all three species: 2n = 26 small chromosomes, predominantly metacentric. All three species exhibited CMA+ bands on the secondary constriction of chromosome pair 4. A size-heteromorphic 35S rDNA site was co-localized with the CMA+ band. A 5S rDNA site was located in the proximal region of chromosome pair 7. The patterns of genomic hybridization revealed that the repetitive DNA fraction of the species is highly similar in terms of proportion of genome, sequence type, and distribution. Our findings did not allow us to differentiate the three species and point to the importance of deeper genomic studies to elucidate the taxonomic controversy.

     

A model of DENV-3 infection that recapitulates severe disease and highlights the importance of IFN-γ in host resistance to infection

There are few animal models of dengue infection, especially in immunocompetent mice. Here, we describe alterations found in adult immunocompetent mice inoculated with an adapted Dengue virus (DENV-3) strain. Infection of mice with the adapted DENV-3 caused inoculum-dependent lethality that was preceded by several hematological and biochemical changes and increased virus dissemination, features consistent with severe disease manifestation in humans. IFN-γ expression increased after DENV-3 infection of WT mice and this was preceded by increase in expression of IL-12 and IL-18. In DENV-3-inoculated IFN-γ(-/-) mice, there was enhanced lethality, which was preceded by severe disease manifestation and virus replication. Lack of IFN-γ production was associated with diminished NO-synthase 2 (NOS2) expression and higher susceptibility of NOS2(-/-) mice to DENV-3 infection. Therefore, mechanisms of protection to DENV-3 infection rely on IFN-γ-NOS2-NO-dependent control of viral replication and of disease severity, a pathway showed to be relevant for resistance to DENV infection in other experimental and clinical settings. Thus, the model of DENV-3 infection in immunocompetent mice described here represents a significant advance in animal models of severe dengue disease and may provide an important tool to the elucidation of immunopathogenesis of disease and of protective mechanisms associated with infection.