Laboratory Surveillance of Dengue in Rio Grande do Sul,Brazil, from 2007 to 2013

Background

According to official records, dengue was introduced in Brazil in the 80''s; since then several epidemics have occurred. Meanwhile, in Rio Grande do Sul (RS, Southern Brazil) the first autochthonous case occurred only in 2007.

Methodology and Principal Findings

In this study we report laboratory surveillance of dengue cases and seasonality of positive cases, describe serotypes and characterize the epidemiological pattern of dengue in RS from 2007 to 2013. A total of 9,779 serum samples from patients with suspected dengue fever were collected and submitted to molecular and/or serological analyses for dengue virus identification and serotyping, based on viral isolation, NS1 antigen detection and qRT-PCR, or Dengue IgM capture ELISA and MAC-ELISA. The first autochthonous dengue case in RS was confirmed in 2007 (DENV-3). While in 2008 and 2009 only imported cases were registered, autochthonous infection waves have been occurring since 2010. The highest number of dengue infections occurred in 2010, with DENV-1 and DENV-2 outbreaks in Northwestern RS. In 2011, another DENV-1 and DENV-2 outbreak occurred in the Northwestern region; moreover, DENV-4 was detected in travelers. In 2012, DENV-1 and DENV-4 co-circulated. DENV-2 circulation was only detected again in 2013, in high frequency (56.7%), co-circulating with DENV-4 (35%). Most infections occur in adults during summer. Differences in prevalence between genders were observed in 2007 (60% females), 2008 (60.8% males) and 2009 (77.5% males).

Conclusions

According to results of dengue surveillance, there was an increase in the number of dengue cases in RS and of cities infested with Aedes aegypti, possibly as a consequence of introduction of new serotypes and the difficulty of health programs to control the vector.     

ABO Genotype, ‘Blood-Type’ Diet and Cardiometabolic Risk Factors

Background

The ‘Blood-Type’ diet advises individuals to eat according to their ABO blood group to improve their health and decrease risk of chronic diseases such as cardiovascular disease. However, the association between blood type-based dietary patterns and health outcomes has not been examined. The objective of this study was to determine the association between ‘blood-type’ diets and biomarkers of cardiometabolic health and whether an individual''s ABO genotype modifies any associations.

Methods

Subjects (n = 1,455) were participants of the Toronto Nutrigenomics and Health study. Dietary intake was assessed using a one-month, 196-item food frequency questionnaire and a diet score was calculated to determine relative adherence to each of the four ‘Blood-Type’ diets. ABO blood group was determined by genotyping rs8176719 and rs8176746 in the ABO gene. ANCOVA, with age, sex, ethnicity, and energy intake as covariates, was used to compare cardiometabolic biomarkers across tertiles of each ‘Blood-Type’ diet score.

Results

Adherence to the Type-A diet was associated with lower BMI, waist circumference, blood pressure, serum cholesterol, triglycerides, insulin, HOMA-IR and HOMA-Beta (P<0.05). Adherence to the Type-AB diet was also associated with lower levels of these biomarkers (P<0.05), except for BMI and waist circumference. Adherence to the Type-O diet was associated with lower triglycerides (P<0.0001). Matching the ‘Blood-Type’ diets with the corresponding blood group did not change the effect size of any of these associations. No significant association was found for the Type-B diet.

Conclusions

Adherence to certain ‘Blood-Type’ diets is associated with favorable effects on some cardiometabolic risk factors, but these associations were independent of an individual''s ABO genotype, so the findings do not support the ‘Blood-Type’ diet hypothesis.     

Paradox lost: variable colour-pattern geometry is associated with differences in movement in aposematic frogs

Aposematic signal variation is a paradox: predators are better at learning and retaining the association between conspicuousness and unprofitability when signal variation is low. Movement patterns and variable colour patterns are linked in non-aposematic species: striped patterns generate illusions of altered speed and direction when moving linearly, affecting predators'' tracking ability; blotched patterns benefit instead from unpredictable pauses and random movement. We tested whether the extensive colour-pattern variation in an aposematic frog is linked to movement, and found that individuals moving directionally and faster have more elongated patterns than individuals moving randomly and slowly. This may help explain the paradox of polymorphic aposematism: variable warning signals may reduce protection, but predator defence might still be effective if specific behaviours are tuned to specific signals. The interacting effects of behavioural and morphological traits may be a key to the evolution of warning signals.     

Effect of the aspartic acid D2 on the affinity of Polybia-MP1 to anionic lipid vesicles

Polybia-MP1 (IDWKKLLDAAKQIL-NH₂), a helical peptide extracted from the venom of a Brazilian wasp, has broad-spectrum antimicrobial activities without being hemolytic or cytotoxic. This peptide has also displayed anticancer activity against cancer cell cultures. Despite its high selectivity, MP1 has an unusual low net charge (Q = +2). The aspartic residue (D2) in the N-terminal region plays an important role in its affinity and selectivity; its substitution by asparagine (D2N mutant) led to a less selective peptide. Aiming to explore the importance of this residue for the peptides’ affinity, we compared the zwitterionic and anionic vesicle adsorption activity of Polybia-MP1 versus its D2N mutant and also mastoparan X (MPX). The adsorption, electrostatic, and conformational free energies were assessed by circular dichroism (CD) and fluorescence titrations using large unilamellar vesicles (LUVs) at the same conditions in association with measurement of the zeta potential of LUVs in the presence of the peptides. The adsorption free energies of the peptides, determined from the partition coefficients, indicated higher affinity of MP1 to anionic vesicles compared with the D2N mutant and MPX. The electrostatic and conformational free energies of MP1 in anionic vesicles are less favorable than those found for the D2N mutant and MPX. Therefore, the highest affinity of MP1 to anionic vesicles is likely due to other energetic contributions. The presence of D2 in MP1 makes these energetic components 1.2 and 1.5 kcal/mol more favorable compared with the D2N mutant and MPX, respectively.     

Features of the milk whey protein partitioning in polyethyleneglycol-sodium citrate aqueous two-phase systems with the goal of isolating human alpha-1 antitrypsin expressed in bovine milk

Partitioning behaviour of the bovine whey proteins (bovine serum albumin, alpha-lactoalbumin and beta-lactoglobulin) and human alpha-1 antitrypsin in aqueous two-phase systems prepared with polyethyleneglycol (molecular masses: 1000, 1450 and 3350)-sodium citrate was analysed at pH 5.2, 6.2 and 8.2. Alpha lactoalbumin concentrated in the polyethyleneglycol rich-phase, while beta-lactoglobulin, bovine serum albumin and alpha-1 antitrypsin showed affinity for the citrate rich-phase. In aqueous two-phase systems of high medium pH and high polyethyleneglycol molecular mass the protein partitioning equilibrium is displaced to the citrate rich-phase. The polyethyleneglycol 1450-pH 5.2 system with a top/bottom phase-volume ratio of 3 showed to have the best capability of recovering the alpha-1 antitrypsin from a mixture prepared with natural milk whey and human alpha-1 antitrypsin. The recovery of this protein in the bottom phase was of 90% and the purity of the obtained product was of 98%. The method appears to be suitable as a starting point to isolate other human proteins expressed in transgenic bovine milk.     

Polyethyleneglycol molecular mass and polydispersivity effect on protein partitioning in aqueous two-phase systems

The partitioning of model proteins (bovine serum albumin, ovalbumin, trypsin and lysozyme) was assayed in aqueous two-phase systems formed by a salt (potassium phosphate, sodium sulfate and ammonium sulfate) and a mixture of two polyethyleneglycols of different molecular mass. The ratio between the PEG masses in the mixtures was changed in order to obtain different polymer average molecular mass. The effect of polymer molecular mass and polydispersivity on the protein partition coefficient was studied. The relationship between the logarithm of the protein partition coefficient and the average molecular mass of the phase-forming polymer was found to depend on the polyethyleneglycol molecular mass, the salt type in the bottom phase and the molecular weight of the partitioned protein. The polymer polydispersivity proved to be a very useful tool to increase the separation between two proteins having similar isoelectrical point.     

Behavioural,ecological, and evolutionary aspects of diversity in frog colour patterns

The role of colours and colour patterns in behavioural ecology has been extensively studied in a variety of contexts and taxa, while almost overlooked in many others. For decades anurans have been the focus of research on acoustic signalling due to the prominence of vocalisations in their communication. Much less attention has been paid to the enormous diversity of colours, colour patterns, and other types of putative visual signals exhibited by frogs. With the exception of some anecdotal observations and studies, the link between colour patterns and the behavioural and evolutionary ecology of anurans had not been addressed until approximately two decades ago. Since then, there has been ever‐increasing interest in studying how colouration is tied to different aspects of frog behaviour, ecology and evolution. Here I review the literature on three different contexts in which frog colouration has been recently studied: predator–prey interactions, intraspecific communication, and habitat use; and I highlight those aspects that make frogs an excellent, yet understudied, group to examine the role of colour in the evolution of anti‐predation strategies and animal communication systems. Further, I argue that in addition to natural‐history observations, more experiments are needed in order to elucidate the functions of anuran colouration and the selective pressures involved in its diversity. To conclude, I encourage researchers to strengthen current experimental approaches, and suggest future directions that may broaden our current understanding of the adaptive value of anuran colour pattern diversity.     

Colourful traits in female birds relate to individual condition,reproductive performance and male-mate preferences: a meta-analytic approach

Colourful traits in females are suggested to have evolved and be maintained by sexual selection. Although several studies have evaluated this idea, support is still equivocal. Evidence has been compiled in reviews, and a handful of quantitative syntheses has explored cumulative support for the link between condition and specific colour traits in males and females. However, understanding the potential function of females'' colourful traits in sexual communication has not been the primary focus of any of those previous studies. Here, using a meta-analytic approach, we find that evidence from empirical studies in birds supports the idea that colourful female ornaments are positively associated with residual mass and immune response, clutch size and male-mate preferences. Hence, colourful traits in female birds likely evolved and are maintained by sexual selection as condition-dependent signals.     

Neuroprotector effect of p,p'-methoxyl-diphenyl diselenide in a model of sporadic dementia of Alzheimer's type in mice: contribution of antioxidant mechanism

The present study investigated whether the antioxidant activity of p,p'‐methoxyl‐diphenyl diselenide [(MeOPhSe)₂] is involved in its protective effect against cognitive impairment induced by streptozotocin (STZ) in a model of sporadic dementia of Alzheimer's type (SDAT). Swiss mice were treated with STZ or vehicle [2 µl of 2·5 mg ml^?1 solution; intracerebroventricularly (i.c.v.)] twice, 48 h apart. (MeOPhSe)₂ (25 mg kg^?1) or vehicle was orally administered 30 min prior to each STZ treatment. Neuroprotector effect of (MeOPhSe)₂ on the behavioral performance of mice on spatial recognition memory consolidation was investigated in the Y‐maze test. After that, mouse brains were removed for measuring antioxidant parameters. (MeOPhSe)₂ protected against the impairment in learning and memory caused by i.c.v. administration of STZ in mice. (MeOPhSe)₂ protected against the increase in reactive species and the reduction of glutathione levels, as well as, the increase in superoxide dismutase and glutathione S‐transferase activities caused by STZ in whole brain. These results suggest that antioxidant property is involved, at least in part, in the neuroprotective effect of (MeOPhSe)₂ on SDAT induced by STZ in mice. Copyright © 2011 John Wiley & Sons, Ltd.     

Effects of capture,shearing, and release on the ecology and behavior of wild vicuñas

The goals of sustainable use of wildlife include minimizing long term deleterious impacts of management. We evaluated the ethoecological and demographic responses of wild vicuñas (Vicugna vicugna) to capture, shearing, and release in northern Argentina, as well as effects on behavior, by comparing captured and shorn versus non-captured animals for 2 yr after capture events. We observed subtle and short-term changes in the movement behavior of individuals, likely due to thermal and behavioral stress following capture. We did not observe changes in survival and birth rates, social organization, or distribution of animals following capture. Therefore, we concluded that the capture techniques used resulted in low impacts on the wild vicuña population. © 2011 The Wildlife Society.