Inflammatory intestinal damage induced by 5-fluorouracil requires IL-4

Background5-Fluorouracil (5-FU) induces intestinal mucositis, which is characterized by epithelial ulcerations in the mucosa and clinical manifestations, such as pain and dyspeptic symptoms. Cytokines participate in the inflammatory and functional events of intestinal mucositis. IL-4 is an important mediator of intestinal inflammation, with either anti-inflammatory or pro-inflammatory functions, depending on the model of intestinal inflammation. This study aimed to evaluate the role of IL-4 in 5-FU-induced intestinal mucositis.MethodsIL-4^+/+ or IL-4^?/? mice (25–30 g) were intraperitoneally injected with 5-FU (450 mg/Kg) or saline (C). After 3 days, the mice were sacrificed and the duodenum was evaluated for epithelial damage, MPO activity and cytokine concentration.Results5-FU induced significant damage in the intestinal epithelium of IL-4^+/+ mice (reduction in the villus/crypt ratio: control = 3.31 ± 0.21 μm, 5-FU = 0.99 ± 0.10 μm). However, the same treatment did not induce significant damage in IL-4^?/? mice (5-FU = 2.87 ± 0.19 μm) compared to wild-type mice. 5-FU-induced epithelial damage increased the MPO activity (neutrophil number) and the level of pro-inflammatory cytokines (IL-4, TNF-α, IL-1β and CXCL-8) in the duodenum. These results were not observed in IL-4^?/? mice treated with 5-FU.ConclusionOur data suggest that IL-4 participates as a pro-inflammatory cytokine in a 5-FU-induced intestinal damage model and suggests that IL-4 antagonists may be novel therapeutics for this condition.     

Identification of Bacterial Infection in Neotropical Primates

Emerging infectious diseases usually arise from wild animal populations. In the present work, we performed a screening for bacterial infection in natural populations of New World primates. The blood cell bulk DNAs from 181 individuals of four Platyrrhini genera were PCR screened for eubacterial 16S rRNA genes. Bacteria were detected and identified in 13 distinct individuals of Alouatta belzebul, Alouatta caraya, and Cebus apella monkeys from geographically distant regions in the states of Mato Grosso and Pará, Brazil. Sequence analyses showed that these Platyrrhini bacteria are closely related not only to human pathogens Pseudomonas spp. but also to Pseudomonas simiae and sheep-Acari infecting Pseudomonas spp. The identified Pseudomonas possibly represents a group of bacteria circulating in natural monkey populations.     

Influence of Soil Physical Properties on Plants of the Mussununga Ecosystem, Brazil

Distribution ranges of plant species are related to physical variables of ecosystems that limit plant growth. Therefore, each plant species response to physical factors builds up the functional diversity of an ecosystem. The higher the species richness of an ecosystem, the larger the probability of maintaining functions and the higher the potential number of plant functional groups (FGs). Thus, the richness potentially increases the number of functions of the highly diverse Atlantic Rainforest domain in Brazil. Severe plant growth limitations caused by stress, however, decrease species richness. In the Spodosols of the Mussununga, an associated ecosystem of Atlantic Rainforest, the percentage of fine sand is directly related to water retention. Moreover, the depth of the cementation layer in the Mussununga??s sandy soil is a physical factor that can affect the plants?? stress gradients. When a shallow cementation layer depth is combined with low water retention in soils and with low fine sand percentage, the double stresses of flooding in the rainy season and water scarcity in the dry season result. This study aimed to identify FGs among Mussununga plant species responding to water stress gradients of soil and to verify the effects of the gradients on plant species richness of the Mussununga. A canonical correspondence analysis (CCA) of species abundance and soil texture variables was performed on 18 plots in six physiognomies of the Mussununga. Species richness rarefactions were calculated for each vegetation form to compare diversity. The two main axes of the CCA showed two FGs responding to soil texture and cementation layer depth: stress tolerator species and mesic species. Physical variables affect plant diversity, with species richness rising as the fine sand proportion also rises in the Mussununga. The effect of the cementation layer is not significantly related to species richness variation.     

Biomechanical analysis of the anterior cervical fusion

This paper presents a biomechanical analysis of the cervical C5-C6 functional spine unit before and after the anterior cervical discectomy and fusion. The aim of this work is to study the influence of the medical procedure and its instrumentation on range of motion and stress distribution. First, a three-dimensional finite element model of the lower cervical spine is obtained from computed tomography images using a pipeline of image processing, geometric modelling and mesh generation software. Then, a finite element study of parameters' influence on motion and a stress analysis at physiological and different post-operative scenarios were made for the basic movements of the cervical spine. It was confirmed that the results were very sensitive to intervertebral disc properties. The insertion of an anterior cervical plate influenced the stress distribution at the vertebral level as well as in the bone graft. Additionally, stress values in the graft decreased when it is used together with a cage.     

Harmonia axyridis: What will stop the invader?

In recent years Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) has become a very popular insect among biological control practitioners and scientists, not only for its potential to be an efficient biological control agent but also because it is considered invasive. Individuals of this species were deliberately introduced into several countries for biological control of different arthropods pests. However the predator itself became an invasive species, affecting the dynamics and composition of several guilds through direct or indirect interactions with established species, including intraguild predation. In this paper we discuss the reasons why the species has a high invasiveness and what are the limits to invasion by this species. It is not clear if the invasiveness of the beetle is linked to its biological, ecological and behavioural abilities, or to other factors such as invasibility and interactions between the invaders, the noninvaders, and the habitat, which may in part explain the reasons of its success and help us to answer the question “what will stop the invader?” We also discuss the reason for the absence of the predator in the Azores islands. Despite the intentional introduction of H. axyridis in the Azores and the high number of individuals released, there are no records of this species in the wild, despite recent extensive sampling effort. In this paper we discuss the reasons for the apparent failure or the delay in establishment of the predator. One factor which may hamper the establishment of H. axyridis in some of the Azores islands is the absence of winter environmental conditions, mainly the temperature which is seldom lower than 12°C, essential for the induction of diapause. The lack of success in the establishment could be also related to functional diversity saturation, that is species saturation and competitive exclusion of H. axyridis by other previously established species may be operating.     

l-3,4-Dihydroxyphenylalanine (l-DOPA) secreted by oyster (Crassostrea gigas) mantle cells: functional aspects

l-DOPA is present in many molluscan periostraca and is thought to play an important role in the shell protein sclerotization mechanism. We analyzed l-DOPA content in organic membranes produced by the oyster (Crassostrea gigas) mantle as a reaction against shell damage, such as induced by Polydora sp. infestation, an artificial perforation of the shell, and in normal oysters mantle. When oysters are secreting the protective organic membrane against a shell perforation, the area of mantle close to the repairing region had a greater l-DOPA content than the remaining mantle. Mantle border as a whole had the same l-DOPA content as the central mantle. Nevertheless there is a variation pattern in mantle border l-DOPA content, the area near the umbo having a higher content and decreasing towards the frontal region. l-DOPA content in younger oysters was greater than that in older oysters. The results of perforation experiment suggest a good correlation between organic membrane synthesis and l-DOPA mantle border content. Concerning normal oysters, a higher l-DOPA content in mantle border than in central mantle would be expected but we couldn’t detect any differences. From all the results there is some evidence that mantle l-DOPA is related to other functions in addition to participating in the sclerotization mechanism.     

Supercritical carbon dioxide extraction of hydrocarbons from the microalgaBotryococcus braunii

Samples of the microalgaBotryococcus braunii were submitted to supercritical fluid extraction with carbon dioxide at 40 °C and pressures of 12.5, 20.0 and 30.0 MPa. The extraction yield and the fraction of the hydrocarbons in the extracts both increased with pressure and at 30 MPa these compounds were obtained rapidly. This behaviour is associated with the localization of the hydrocarbons outside the cell wall. In the extracts, which are fluid, golden and limpid, chlorophyll and phospholipids were not detected.Author for correspondence