A hormonal misunderstanding in Acca sellowiana embryogenesis: levels of zygotic embryogenesis do not match those of somatic embryogenesis

Endogenous levels of IAA, ABA and four types of CKs were analyzed in zygotic and indirect (ISE) and direct somatic embryogenesis of Acca sellowiana. Zygotic and somatic embryos at different developmental stages were sampled for morphological and hormonal analysis. Both embryo types showed substantial asymmetry in hormone levels. Zygotic embryos displayed a conspicuous peak of IAA in early developmental stages. The results outlined the hormonal variations occurring during zygotic and somatic embryogenesis regarding the timing, nature and hormonal status involved in both processes. The short transient pulse of IAA observed on the 3rd day in culture was suggested to be involved with the signaling for the induction of somatic embryogenesis. Fertilized ovule development was associated with increased IAA levels 21?C24?days after pollination, followed by a sharp decrease in the cotyledonary stage, both in zygotic and somatic embryos. There was a prominent increase in ABA levels in cultures which generated ISE 24?C30?days after pollination, a period that corresponds to the heart and torpedo stages. The levels of total CKs (Z, [9R]Z, iP and [9R]iP) were also always higher in zygotic than in somatic embryogenesis. While zygotic embryogenesis was dominated by the presence of zeatin, the somatic process, contrarily, was characterized by a large variation of the other cytokinin forms and amounts studied. The above results, when taken together, could be related to the previously observed high frequency formation of anomalous somatic embryos formed in A. sellowiana, as well as to their low germination ability.     

Optimization of fermentation conditions for the production of human soluble catechol-O-methyltransferase by Escherichia coli using artificial neural network

The aim of this work was to optimize the temperature, pH and stirring rate of the production of human soluble catechol-O-methyltransferase (hSCOMT) in a batch Escherichia coli culture process. A central composite design (CCD) was firstly employed to design the experimental assays used in the evaluation of these operational parameters on the hSCOMT activity for a semi-defined and complex medium. Predictive artificial neural network (ANN) models of the hSCOMT activity as function of the combined effects of these variables was proposed based on this exploratory experiments performed for the two culture media. The regression coefficients (R(2)) for the final models were 0.980 and 0.983 for the semi-defined and complex medium, respectively. The ANN models predicted a maximum hSCOMT activity of 183.73 nmol/h, at 40 °C, pH 6.5 and stirring rate of 351 rpm, and 132.90 nmol/h, at 35 °C, pH 6.2 and stirring rate of 351 rpm, for semi-defined and complex medium, respectively. These results represent a 4-fold increase in total hSCOMT activity by comparison to the standard operational conditions used for this bioprocess at slight scale.     

Do Feeding Resources Induce the Adoption of Resource Defence Polygyny in a Lekking Butterfly?

Among polygynous species, males often compete for the possession of mating sites to increase their reproductive success. Weaker individuals frequently adopt alternative non‐territorial mate‐locating tactics, but the adoption of alternative territorial tactics may also occur. Although alternative tactics with territory defence are less common in arthropods, factors that drive its adoption may provide information to understand the organization of different territorial mating systems in the group. Here we investigate the adoption of resource‐based territoriality as an alternative to a non‐resource‐based one by males of the butterfly Paryphthimoides phronius. Male P. phronius commonly defend sunny clearings lacking feeding resources in the forest edge (non‐resource‐based territoriality). However, after experimentally offering fermenting fruit in previously undefended sites, we showed that males also adopt a resource defence tactic. Males in territories with fermenting fruits apparently feed on this resource when they are not defending the territory. However, males in sites without resources did not migrate to territories with resources when given the opportunity. To our knowledge, this is the first experimental investigation to show a non‐resource‐ and an alternative resource‐based mate‐locating tactic in a butterfly. We suggest that this behavioural flexibility may represent an important step to understand the ecological factors responsible for the organization and evolution of different territorial mating systems in insects.     

Characterization of selectivity and pharmacophores of type 1 sea anemone toxins by screening seven Na(v) sodium channel isoforms

During their evolution, animals have developed a set of cysteine-rich peptides capable of binding various extracellular sites of voltage-gated sodium channels (VGSC). Sea anemone toxins that target VGSCs delay their inactivation process, but little is known about their selectivities. Here we report the investigation of three native type 1 toxins (CGTX-II, δ-AITX-Bcg1a and δ-AITX-Bcg1b) purified from the venom of Bunodosoma cangicum. Both δ-AITX-Bcg1a and δ-AITX-Bcg1b toxins were fully sequenced. The three peptides were evaluated by patch-clamp technique among Nav1.1-1.7 isoforms expressed in mammalian cell lines, and their preferential targets are Na(v)1.5>1.6>1.1. We also evaluated the role of some supposedly critical residues in the toxins which would interact with the channels, and observed that some substitutions are not critical as expected. In addition, CGTX-II and δ-AITX-Bcg1a evoke different shifts in activation/inactivation Boltzmann curves in Nav1.1 and 1.6. Moreover, our results suggest that the interaction region between toxins and VGSCs is not restricted to the supposed site 3 (S3-S4 linker of domain IV), and this may be a consequence of distinct surface of contact of each peptide vs. targeted channel. Our data suggest that the contact surfaces of each peptide may be related to their surface charges, as CGTX-II is more positive than δ-AITX-Bcg1a and δ-AITX-Bcg1b.     

SORL1 and SIRT1 mRNA expression and promoter methylation levels in aging and Alzheimer’s Disease

Alzheimer’s Disease (AD) is a neurodegenerative disorder and the most common cause of dementia among the elderly. Efforts have been made to understand the genetic and epigenetic mechanisms involved in the development of this disease. As SORL1 (sortilin-related receptor) and SIRT1 (sirtuin 1) genes have been linked to AD pathogenesis, we aimed to investigate their mRNA expression and promoter DNA methylation in post mortem brain tissues (entorhinal and auditory cortices and hippocampus) from healthy elderly subjects and AD patients. We also evaluated these levels in peripheral blood leukocytes from young, healthy elderly and AD patients, investigating whether there was an effect of age on these profiles. The comparative CT method by Real Time PCR and MALDI-TOF mass spectrometry were used to analyze gene expression and DNA methylation, respectively. SORL1 gene was differently expressed in the peripheral blood leukocytes and might act as a marker of aging in this tissue. Furthermore, we found that SORL1 promoter DNA methylation might act as one of the mechanisms responsible for the differences in expression observed between blood and brain for both healthy elderly and AD patients groups. The impact of these studied genes on AD pathogenesis remains to be better clarified.     

Recovery of the pubic symphysis on primiparous young and multiparous senescent mice at postpartum

It has been observed that parturition has a significant effect on female skeletal architecture and that age alters musculoskeletal tissues and their functions. We therefore hypothesized that multiparity affects the recovery of the pubic symphysis in senescent mice at postpartum and the morphology of the interpubic tissues. The pubic symphysis of primiparous young, virgin senescent (VS) and multiparous senescent (MS) Swiss mice was examined by light microscopy, transmission electron microscopy, morphometric analysis and immunohistochemistry. The mouse pubic symphysis was remodeled during the first pregnancy: the cellular phenotype and morphology changed to ensure a structurally safe birth canal, followed by recovery of the interpubic articulation after birth. The morphology of the pubic symphysis in the VS group was maintained in a state similar to that observed in virgin young mice. In contrast, MS mice exhibited an interpubic ligament characterized by extended fibrocyte-like cells, an opened interpubic articulation gap, compacted and thin collagen fibrils and scarce galectin-3-positive cells. Thus, we found that the cellular and extracellular characteristics of the pubic symphysis were altered by multiparity in senescent mice. These particular tissue characteristics of the MS group might be associated with an impaired recovery process at postpartum. Thus, a better understanding of the alterations that occur in the birth canal, including the pubic symphysis, due to multiparity in reproductively aged mice may contribute to our comprehension of the biological mechanisms that modify the skeleton and pelvic ligaments and even play a role in the murine model of pelvic organ prolapse.     

Antimicrobial efficacy of alcohol-based hand gels with a 30-s application

Aims: The objective of this study was to assess the antimicrobial efficacy of alcohol‐based hand gels according to European Norm 1500 (EN 1500). Methods and Results: We assessed the antimicrobial efficacy of 12 alcohol‐based hand gels produced in Brazil, containing 70% w/w or v/v ethyl alcohol as the active ingredient, according to EN 1500, with a 30‐s application. In addition, 70% w/w ethyl alcohol and three alcohol‐based hand rubs commonly used in Europe and effective according to EN 1500 were also tested. Eight of 12 (67%) alcohol‐based hand gels produced in Brazil failed by EN 1500. In contrast, 70% w/w ethyl alcohol and European alcohol‐based hand rubs were approved by EN 1500. Conclusions: In this study, the majority of Brazilian alcohol‐based hand gels showed limited efficacy on hand hygiene within 30 s. Significance and Impact of the Study: The findings of this study may be used as an important argument to motivate Brazilian manufacturers to improve the antimicrobial efficacy of alcohol‐based hand gels, because it is prudent to suppose that alcohol‐based hand gels can be recommended for use in healthcare settings only if they show antimicrobial activity at least similar to that of alcohol‐based liquid preparations, including the traditional 70% w/w ethyl alcohol.     

Influence of previous residency and body mass in the territorial contests of the butterfly Hermeuptychia fallax (Lepidoptera: Satyrinae)

Although many studies have evaluated the possible rules used by males to settle territorial contests, few have simultaneously considered the possibility of mutual or self-assessment of fighting ability and the effect of prior residence on the chances of winning. Here, we experimentally investigated the influence of previous residency on the development and outcome of contests between males of the butterfly Hermeuptychia fallax. By comparing the frequency of resident victories in nonmanipulated disputes versus interactions in which both rivals were induced to behave as residents, we showed that prior residency may interact with body mass in contest resolution. In nonmanipulated disputes, resident males showed high winning probabilities, although they were similar to losers in body mass. However, when both males behaved as residents, the disputes were longer and were settled in favor of the heavier male. This indicates that, although residency is an important component of male willingness to fight, it is not the only factor influencing conflict resolution. Despite the correlation between body mass and territorial success, the weight of neither winners nor losers correlated with fighting duration. We conclude that residence asymmetry may sometimes conceal male traits important to contest resolution and that it may obscure the identification of the assessment strategy used in contests.     

Feeding ecology and prey preferences of a piscivorous fish in the Lagoa do Peixe National Park, a Biosphere Reserve in Southern Brazil

We investigated the diet, feeding strategy, size-related dietary shifts and prey preferences of South American Hoplias aff. malabaricus in an internationally recognized but poorly investigated Biosphere Reserve in southern Brazil. Fish were caught between April 2008 and March 2009 using a variety of fishing gear. The analysis of 113 individuals revealed a diet essentially composed of fish (16 species), particularly characid species (9). The diet became more diverse and contained larger fish prey with increasing predator size. Feeding strategy analysis revealed a clear specialization towards the consumption of fish. However, individuals did not prey upon particular prey species, instead opportunistically consuming many different fish species, which could be a strategy to avoid intraspecific competition. Characid species were the most important prey, followed by poecillids. A multi-gear sampling of the ichthyofauna revealed that these prey species were the most abundant (Characidae: 61.3%, Poeciliidae 18.8%) of the 14 fish families occurring at the study site, suggesting that the predator exploits the most abundant fish resources available rather than the rarer fish prey. These findings suggest that potential top-down controls exerted by H. aff. malabaricus in this system follow specific food web pathways that seem to be mediated by the abundance of prey resources.     

Profile of circulating levels of IL-1Ra, CXCL10/IP-10, CCL4/MIP-1β and CCL2/MCP-1 in dengue fever and parvovirosis

Dengue virus (DENV) and parvovirus B19 (B19V) infections are acute exanthematic febrile illnesses that are not easily differentiated on clinical grounds and affect the paediatric population. Patients with these acute exanthematic diseases were studied. Fever was more frequent in DENV than in B19V-infected patients. Arthritis/arthralgias with DENV infection were shown to be significantly more frequent in adults than in children. The circulating levels of interleukin (IL)-1 receptor antagonist (Ra), CXCL10/inducible protein-10 (IP-10), CCL4/macrophage inflammatory protein-1 beta and CCL2/monocyte chemotactic protein-1 (MCP-1) were determined by multiplex immunoassay in serum samples obtained from B19V (37) and DENV-infected (36) patients and from healthy individuals (7). Forward stepwise logistic regression analysis revealed that circulating CXCL10/IP-10 tends to be associated with DENV infection and that IL-1Ra was significantly associated with DENV infection. Similar analysis showed that circulating CCL2/MCP-1 tends to be associated with B19V infection. In dengue fever, increased circulating IL-1Ra may exert antipyretic actions in an effort to counteract the already increased concentrations of IL-1β, while CXCL10/IP-10 was confirmed as a strong pro-inflammatory marker. Recruitment of monocytes/macrophages and upregulation of the humoral immune response by CCL2/MCP-1 by B19V may be involved in the persistence of the infection. Children with B19V or DENV infections had levels of these cytokines similar to those of adult patients.