The TcI and TcII Trypanosoma cruzi experimental infections induce distinct immune responses and cardiac fibrosis in dogs

Trypanosoma cruzi infection may be caused by different strains with distinct discrete typing units (DTUs) that can result in variable clinical forms of chronic Chagas disease. The present study evaluates the immune response and cardiac lesions in dogs experimentally infected with different T. cruzi strains with distinct DTUs, namely, the Colombian (Col) and Y strains of TcI and TcII DTU, respectively. During infection with the Col strain, increased levels of alanine aminotransferase, erythrocytes, haematocrit and haemoglobin were observed. In addition, CD8⁺ T-lymphocytes isolated from the peripheral blood produced higher levels of interleukin (IL)-4. The latter suggests that during the acute phase, infection with the Col strain may remain unnoticed by circulating mononuclear cells. In the chronic phase, a significant increase in the number of inflammatory cells was detected in the right atrium. Conversely, infection with the Y strain led to leucopoenia, thrombopoenia, inversion of the ratio of CD4⁺/CD8⁺ T-lymphocytes and alterations in monocyte number. The Y strain stimulated the production of interferon-γ by CD4⁺ and CD8⁺ T-lymphocytes and IL-4 by CD8⁺ T-cells. In the chronic phase, significant heart inflammation and fibrosis were observed, demonstrating that strains of different DTUs interact differently with the host.     

Myenteric plexus is differentially affected by infection with distinct Trypanosoma cruzi strains in Beagle dogs

Chagasic megaoesophagus and megacolon are characterised by motor abnormalities related to enteric nervous system lesions and their development seems to be related to geographic distribution of distinct Trypanosoma cruzi subpopulations. Beagle dogs were infected with Y or Berenice-78 (Be-78) T. cruzi strains and necropsied during the acute or chronic phase of experimental disease for post mortem histopathological evaluation of the oesophagus and colon. Both strains infected the oesophagus and colon and caused an inflammatory response during the acute phase. In the chronic phase, inflammatory process was observed exclusively in the Be-78 infected animals, possibly due to a parasitism persistent only in this group. Myenteric denervation occurred during the acute phase of infection for both strains, but persisted chronically only in Be-78 infected animals. Glial cell involvement occurred earlier in animals infected with the Y strain, while animals infected with the Be-78 strain showed reduced glial fibrillary acidic protein immunoreactive area of enteric glial cells in the chronic phase. These results suggest that although both strains cause lesions in the digestive tract, the Y strain is associated with early control of the lesion, while the Be-78 strain results in progressive gut lesions in this model.     

Endophytic and mycorrhizal fungi associated with roots of endangered native orchids from the Atlantic Forest, Brazil

The composition and diversity of fungal communities associated with three endangered orchid species, Hadrolaelia jongheana, Hoffmannseggella caulescens, and Hoffmannseggella cinnabarina, found in different vegetation formations of the Atlantic Forest were determined by constructing clone libraries and by applying diversity and richness indices. Our results demonstrated the presence of Basidiomycetes. Sebacinales (81.61 %) and Cantharellales (12.10 %) were the dominant orders and are potential candidates for orchid mycorrhizal fungi. The Ascomycetes identified included the Helotiales (29.31 %), Capnodiales (18.10 %), and Sordariales (10.34 %), among others. These orders may represent potentially endophytic fungi. A Shannon–Wiener diversity index (H′) analysis showed a relatively high fungal community diversity associated with these tropical orchids. This diversity may offer greater flexibility in terms of the adaptation of the plants to changing environmental conditions and the potential facilitation of reintroduction programs. The Simpson diversity index values showed that all of the libraries included dominant species, and a LIBSHUFF analysis showed that the fungal communities were structurally different from each other, suggesting an influence of local factors on this diversity. This study offers important information for the development of conservation strategies for threatened and endemic species of Brazilian flora in an important and threatened hotspot.     

Vitamin E and defense-related phytohormones are reliable markers of embryo growth in macaw palm fruits exposed to various storage conditions

The fruit of the macaw palm (Acrocomia aculeata) may be used for biofuel production, but its exploitation as a crop is currently limited by its low germinability. Therefore, obtaining plantlets in vitro is an excellent way to solve this problem. Here we aimed to identify the optimal conditions for storing the fruit before obtaining plantlets and testing to what extent vitamin E and defense-related phytohormones are good indicators of embryo growth in vitro. We tested the effects of four storage conditions (nursery, laboratory, cold chamber and freezer) on seed germinability and embryo growth, and evaluated endogenous levels of vitamin E and defense-related phytohormones (abscisic acid, salicylic acid and jasmonic acid) in the endosperm and embryos. Low temperatures [both cold chamber (5 °C) and freezer (?18 °C) methods] killed the embryos, while storing the fruit in the laboratory was the most efficient method of obtaining plantlets, even after a year. Vitamin E and abscisic acid turned out to be good indicators of embryo growth. Enhanced vitamin E and abscisic acid levels had a strong positive correlation with successful embryo growth, thus indicating that these compounds are needed to protect the embryo during fruit storage. Furthermore, abscisic acid levels had a negative correlation with the percentage of contaminated embryos, thus suggesting that the endogenous physiological stage of the seeds affects subsequent contamination in in vitro cultures. We concluded that (1) storing fruit under laboratory conditions is the most efficient means of obtaining plantlets successfully, and (2) vitamin E and abscisic acid can be used as reliable indicators of embryo growth during in vitro culture.     

Ibf1 and Ibf2 are novel CP190‐interacting proteins required for insulator function

Insulators are DNA‐protein complexes that play a central role in chromatin organization and regulation of gene expression. In Drosophila different proteins, dCTCF, Su(Hw), and BEAF bind to specific subsets of insulators most of them having in common CP190. It has been shown that there are a number of CP190‐binding sites that are not shared with any other known insulator protein, suggesting that other proteins could cooperate with CP190 to regulate insulator activity. Here we report on the identification of two previously uncharacterized proteins as CP190‐interacting proteins, that we have named Ibf1 and Ibf2. These proteins localize at insulator bodies and associate with chromatin at CP190‐binding sites throughout the genome. We also show that Ibf1 and Ibf2 are DNA‐binding proteins that form hetero‐oligomers that mediate CP190 binding to chromatin. Moreover, Ibf1 and Ibf2 are necessary for insulator activity in enhancer‐blocking assays and Ibf2 null mutation cause a homeotic phenotype. Taken together our data reveal a novel pathway of CP190 recruitment to chromatin that is required for insulator activity.     

Patterns of Adherence to and Compliance with the Portuguese Smoke-Free Law in the Leisure-Hospitality Sector

Background

In 2008, the Portuguese smoke-free law came into effect including partial bans in the leisure-hospitality (LH) sector. The objective of the study is to assess the prevalence of smoking control policies (total ban, smoking permission and designated smoking areas) adopted by the LH sector in Portugal. The levels of noncompliance with each policy are investigated as well as the main factors associated with smoking permission and noncompliance with the law.

Methods

Cross-sectional study conducted between January 2010 and May 2011. A random sample of venues was selected from the Portuguese LH sector database, proportionally stratified according to type, size and geographical area. All venues were assessed in loco by an observer. The independent effects of venues'' characteristics on smoking permission and the level of noncompliance with the law were explored using logistic regression.

Results

Overall, 1.412 venues were included. Total ban policy was adopted by 75.9% of venues, while 8.4% had designated smoking areas. Smoking ban was more prevalent in restaurants (85.9%). Only 29.7% of discos/bars/pubs opted for complete ban. Full or partial smoking permission was higher in discos/bar/pubs (OR = 7.37; 95%CI 4.87 to 11.17). Noncompliance with the law was higher in venues allowing smoking and lower in places with complete ban (33.6% and 7.6% respectively, p<0.001). Discos/bars/pubs with full smoking permission had the highest level of noncompliance (OR = 3.31; 95%CI 1.40 to 7.83).

Conclusions

Our findings show a high adherence to smoking ban policy by the Portuguese LH sector. Nonetheless, one quarter of the venues is fully or partially permissive towards smoking, with the discos/bars/pubs considerably contributing to this situation. Venues with smoking permission policies were less compliant with the legislation. The implementation of a comprehensive smoke-free law, without any exceptions, is essential to effectively protect people from the second hand smoke.     

Continuous Increase of Cardiovascular Diseases,Diabetes, and Non-HIV Related Cancers as Causes of Death in HIV-Infected Individuals in Brazil: An Analysis of Nationwide Data

Introduction

After antiretroviral therapy (ART) became available, there was a decline in the number of deaths in persons infected with HIV. Thereafter, there was a decrease in the proportion of deaths attributed to opportunistic infections and an increase in the proportion of deaths attributed to chronic comorbidities. Herein we extend previous observations from a nationwide survey on temporal trends in causes of death in HIV-infected patients in Brazil.

Methods

We describe temporal trends in causes of death among adults who had HIV/AIDS listed in the death certificate to those who did not. All death certificates issued in Brazil from 1999 to 2011 and listed in the national mortality database were included. Generalized linear mixed-effects logistic models were used to study temporal trends in proportions.

Results

In the HIV-infected population, there was an annual adjusted average increase of 6.0%, 12.0%, 4.0% and 4.1% for cancer, external causes, cardiovascular diseases (CVD) and diabetes mellitus (DM), respectively, compared to 3.0%, 4.0%, 1.0% and 3.9%, in the non-HIV group. For tuberculosis (TB), there was an adjusted average increase of 0.3%/year and a decrease of 3.0%/year in the HIV and the non-HIV groups, respectively. Compared to 1999, the odds ratio (OR) for cancer, external causes, CVD, DM, or TB in the HIV group were, respectively, 2.31, 4.17, 1.76, 2.27 and 1.02, while for the non-HIV group, the corresponding OR were 1.31, 1.63, 1.14, 1.62 and 0.67. Interactions between year as a continuous or categorical variable and HIV were significant (p<0.001) for all conditions, except for DM when year was considered as a continuous variable (p = 0.76).

Conclusions

Non HIV-related co-morbidities continue to increase more rapidly as causes of death among HIV-infected individuals than in those without HIV infection, highlighting the need for targeting prevention measures and surveillance for chronic diseases among those patients.     

Competition,niche opportunities and the successful invasion of natural habitats

Fundamental to the establishment of exotic species in natural environments is that the invader finds an appropriate niche in the novel environment. However, it is currently unclear whether this is achieved by competitively displacing native species from their niches and/or by exploiting niche opportunities not monopolized by native species. Combining phylogenetic analyses with field observations and an ecological opportunity experiment, we here contrasted the competition and niche opportunity hypotheses as explanations for the success of an alien passerine, the Red-billed Leiothrix Leiothrix lutea, in a forest reserve from the Western Mediterranean basin. The invasion of Leiothrix provided a rare opportunity to assess the relative importance of each hypothesis because the avian community of the reserve has been systematically surveyed for the last 27 years, and hence species abundance data were available before and after the irruption of the invader. The invader established itself with relatively little resistance or consequences for native species, reflecting the opportunist-generalist nature of both the invader and the invaded native community. Although we cannot completely discard a role of competition, these results yield greater support to the crucial importance of niche opportunities to invade natural environments.     

Focus Issue on Roots: Perennial Roots to Immortality,

Maximum lifespan greatly varies among species, and it is not strictly determined; it can change with species evolution. Clonal growth is a major factor governing maximum lifespan. In the plant kingdom, the maximum lifespans described for clonal and nonclonal plants vary by an order of magnitude, with 43,600 and 5,062 years for Lomatia tasmanica and Pinus longaeva, respectively. Nonclonal perennial plants (those plants exclusively using sexual reproduction) also present a huge diversity in maximum lifespans (from a few to thousands of years) and even more interestingly, contrasting differences in aging patterns. Some plants show a clear physiological deterioration with aging, whereas others do not. Indeed, some plants can even improve their physiological performance as they age (a phenomenon called negative senescence). This diversity in aging patterns responds to species-specific life history traits and mechanisms evolved by each species to adapt to its habitat. Particularities of roots in perennial plants, such as meristem indeterminacy, modular growth, stress resistance, and patterns of senescence, are crucial in establishing perenniality and understanding adaptation of perennial plants to their habitats. Here, the key role of roots for perennial plant longevity will be discussed, taking into account current knowledge and highlighting additional aspects that still require investigation.There is enormous diversity among the types of perennial plants and among their patterns of aging (Jones et al., 2014). Perennial plants can be divided into herbaceous (or perennial herbs) and woody perennials (trees and shrubs), and therefore, they represent very diverse organisms in size and complexity from some herbs that weigh a few grams to huge trees like sequoias (Sequoia sempervirens). Among perennial herbs, the slowest growing species described thus far, Borderea pyrenaica (a small geophyte growing in the Central Pyrenees of northeastern Spain), is also the one with the longest maximum lifespan (350 years; Fig. 1). Interestingly, fecundity of this species increases with aging, representing a case of negative senescence (Garcia et al., 2011; Morales et al., 2013). If mortality falls as size increases and if size increases with age, then mortality will fall with age, and negative senescence occurs (Vaupel et al., 2004). Negative senescence is not common in the tree of life, but it seems to occur in not only some perennial herbs, such as B. pyrenaica (Garcia et al., 2011) and Plantago lanceolata (Roach and Gampe, 2004), but also, other phylogenetically distant organisms, such as turtles (Jones et al., 2014). Other perennial herbs with higher biomass production rates and consequently, larger sizes, such as stinging nettle (Urtica dioica), are much shorter-lived (a few years only). In this case, however, perenniality is achieved by allocating an important part of their energy to asexual reproduction (production of stolons; i.e. clonal propagation), giving rise to new entire clonal plants (Koskela, 2002). Indeed, this process happens in several other plant species with rapid growth that we commonly find in gardens, such as strawberries (Fragaria × ananassa) or raspberries (Rubus idaeus). Stolons can be produced aboveground or underground (in the latter case, forming rhizomes). Van Dijk (2009) elegantly reviewed the direct and indirect methods currently used to estimate plant age in clonal and nonclonal plants, showing several examples of plant species using clonal propagation with maximum lifespans of thousands of years, with the most notable example, King’s Lomatia (Lomatia tasmanica), being dated at 43,600 years (Lynch et al., 1998). Only one wild-living clone of this species is known. Clonal propagation is the only means for propagation, because it is a sterile ancient clone. When a branch falls, that branch produces new roots, establishing a new plant that is genetically identical to its parent (Lynch et al., 1998). Here, the production of new roots becomes essential for achieving potential immortality. Another example of extreme longevity is the bristlecone pine (Pinus longaeva), with a maximum lifespan of 5,062 years. It holds the record of longevity of a single individual within the plant kingdom, which was observed by Tom Harlan during 2012 in a living individual of this species in the White Mountains (the location has not been reported; Earle, 2013).Open in a separate windowFigure 1.Examples of extreme longevity in perennial plants. A, B. pyrenaica, the perennial herb with the longest lifespan described to date. B, A cross section of the tuber of B. pyrenaica showing the scars left by the five meristematic points in the spiral. C, P. longaeva, the species with the individual with the longest lifespan ever recorded (not using clonal propagation). D, C. nodosa meadow, with a detail of the rhizomes (E) that allow clonal propagation and potential immortality in this species. [See online article for color version of this figure.]The enormous diversity in lifespans within a species responds to specific life history traits and mechanisms evolved by each individual to adapt to its habitat. Particularities of roots in perennial plants, such as meristem indeterminacy, modular growth, stress resistance, and patterns of senescence, are crucial in understanding adaptation of perennial plants to their habitats, explaining differences in longevity. Here, the key role of roots in providing long lifespans in perennial plants will be discussed, taking into account current knowledge and highlighting additional aspects that still require investigation.