Crucial role of neutrophils in the development of mechanical inflammatory hypernociception

Neutrophil migration is responsible for tissue damage observed in inflammatory diseases. Neutrophils are also implicated in inflammatory nociception, but mechanisms of their participation have not been elucidated. In the present study, we addressed these mechanisms in the carrageenan-induced mechanical hypernociception, which was determined using a modification of the Randall-Sellito test in rats. Neutrophil accumulation into the plantar tissue was determined by the contents of myeloperoxidase activity, whereas cytokines and PGE(2) levels were measured by ELISA and radioimmunoassay, respectively. The pretreatment of rats with fucoidin (a leukocyte adhesion inhibitor) inhibited carrageenan-induced hypernociception in a dose- and time-dependent manner. Inhibition of hypernociception by fucoidin was associated with prevention of neutrophil recruitment, as it did not inhibit the hypernociception induced by the direct-acting hypernociceptive mediators, PGE(2) and dopamine, which cause hypernociception, independent of neutrophils. Fucoidin had no effect on carrageenan-induced TNF-alpha, IL-1 beta, and cytokine-induced neutrophil chemoattractant 1 (CINC-1)/CXCL1 production, suggesting that neutrophils were not the source of hypernociceptive cytokines. Conversely, hypernociception and neutrophil migration induced by TNF-alpha, IL-1 beta, and CINC-1/CXCL1 was inhibited by fucoidin, suggesting that neutrophils are involved in the production of direct-acting hypernociceptive mediators. Indeed, neutrophils stimulated in vitro with IL-1 beta produced PGE(2), and IL-1 beta-induced PGE(2) production in the rat paw was inhibited by the pretreatment with fucoidin. In conclusion, during the inflammatory process, the migrating neutrophils participate in the cascade of events leading to mechanical hypernociception, at least by mediating the release of direct-acting hypernociceptive mediators, such as PGE(2). Therefore, the blockade of neutrophil migration could be a target to development of new analgesic drugs.

The influence of glutathione modulators on the course of Leishmania major infection in susceptible and resistant mice

Glutathione (GSH) has an important dual role in parasite-host relationship in Leishmania major infection. Our previous studies showed that both antioxidant systems, glutathione and trypanothione/trypanothione reductase, participate in the protection of Leishmania against the toxic effect of nitrogen-derived reactive species. On the other hand, GSH also is very important to the modulation of the effective immune response, inducting NO production and leishmanicidal activity of macrophages. In the present study, we investigated the role of host GSH during the course of L. major infection, analysing the size of footpad lesions and parasite load from mice treated with two GSH modulators, N-acethyl-L-cysteine (NAC) and buthionine sulphoximine (BSO). Resistant mice treated with BSO, which depletes GSH develop exacerbated lesions, but only harbour higher parasite load in their lesions 2 weeks post-infection. Although the NAC treatment does not affect the footpad lesions development in susceptible BALB/c mice, it significantly reduced the tissue parasitism in the lesions throughout the course of infection. Interestingly, the treatment with BSO did not change the course of L. major infection on susceptible mice when compared with nontreated mice. These results suggest that GSH is an important antioxidant modulator during anti-Leishmania immune response in vivo.

Commensal microbiota is fundamental for the development of inflammatory pain

The ability of an individual to sense pain is fundamental for its capacity to adapt to its environment and to avoid damage. The sensation of pain can be enhanced by acute or chronic inflammation. In the present study, we have investigated whether inflammatory pain, as measured by hypernociceptive responses, was modified in the absence of the microbiota. To this end, we evaluated mechanical nociceptive responses induced by a range of inflammatory stimuli in germ-free and conventional mice. Our experiments show that inflammatory hypernociception induced by carrageenan, lipopolysaccharide, TNF-alpha, IL-1 beta, and the chemokine CXCL1 was reduced in germfree mice. In contrast, hypernociception induced by prostaglandins and dopamine was similar in germ-free or conventional mice. Reduction of hypernociception induced by carrageenan was associated with reduced tissue inflammation and could be reversed by reposition of the microbiota or systemic administration of lipopolysaccharide. Significantly, decreased hypernociception in germ-free mice was accompanied by enhanced IL-10 expression upon stimulation and could be reversed by treatment with an anti-IL-10 antibody. Therefore, these results show that contact with commensal microbiota is necessary for mice to develop inflammatory hypernociception. These findings implicate an important role of the interaction between the commensal microbiota and the host in favoring adaptation to environmental stresses, including those that cause pain.

5-Lipoxygenase is a key determinant of acute myocardial inflammation and mortality during Trypanosoma cruzi infection

This study provides evidence supporting the idea that although inflammatory cells migration to the cardiac tissue is necessary to control the growth of Trypanosoma cruzi, the excessive influx of such cells during acute myocarditis may be deleterious to the host. Production of lipid mediators of inflammation like leukotrienes (LTs) along with cytokines and chemokines largely influences the severity of inflammatory injury in response to tissue parasitism. T cruzi infection in mice deficient in 5-lipoxygenase (5-LO), the enzyme responsible for the synthesis of LTs and other lipid inflammatory mediators, resulted in transiently increased parasitemia, and improved survival rate compared with WT mice. Myocardia from 5-LO(-/-) mice exhibited reduced inflammation, collagen deposition, and migration of CD4(+), CD8(+), and IFN-gamma-producer cells compared with WT littermates. Moreover, decreased amounts of TNF-alpha, IFN-gamma, and nitric oxide synthase were found in the hearts of 5-LO(-/-) mice. Interestingly, despite of early higher parasitic load, 5-LO(-/-) mice survived, and controlled T cruzi infection. These results show that efficient parasite clearance is possible in a context of moderate inflammatory response, as occurred in 5-LO(-/-) mice, in which reduced myocarditis protects the animals during T cruzi infection. (c) 2010 Elsevier Masson SAS. All rights reserved.

The A61 G EGF polymorphism is associated with development of extraaxial nervous system tumors but not with overall survival

Epidermal growth factor can activate several signaling pathways, leading to proliferation, differentiation, and tumorigenesis of epithelial tissues by binding with its receptor. The EGF protein is involved in nervous system development, and polymorphisms in the EGF gene on chromosome band 4q25 are associated with brain cancers. The purpose of this study was to investigate the association between the single-nucleotide polymorphism of EGF + 61 G/A and extraaxial brain tumors in a population of the southeast of Brazil. We analyzed the genotype distribution of this polymorphism in 90 patients and 100 healthy subjects, using the polymerase chain reaction restriction fragment length polymorphism technique. Comparison of genotype distribution revealed a significant difference between patients and control subjects (P < 0.001). The variant genotypes of A/G and G/G were associated with a significant increase of the risk of tumor development, compared with the homozygote A/A (P < 0.0001). When the analyses were stratified, we observed that the genotype GIG was more frequent in female patients (P = 0.021). The same genotype was observed more frequently in patients with low-grade tumors (P = 0.001). Overall survival rates did not show statistically significant differences. Our data suggest that the EGF A61 G polymorphism can be associated with susceptibility to development of these tumors. (C) 2010 Elsevier Inc. All rights reserved.

Development and characterization of microsatellite loci in the marsh deer (Blastocerus dichotomus Cervidae)

Marsh deer (Blastocerus dichotomus) is one of the most exposed large mammals in South America. To aid in the conservation management of the species, nine polymorphic microsatellite loci were isolated and tested on up to 50 animals, showing 3-12 alleles and expected heterozygosity values varying from 0.69 to 0.89. These markers should be of considerable utility in future population and ecological genetics studies of this species. The marsh deer (Blastocerus dichotomus) is the biggest South American species of deer. Originally distributed across a large part of South America, stretching from the south bank of the Amazon river to northern Argentina, significant wild populations are now restricted to the Pantanal, swamplands that cover about 40% of southwest Brazil. The marsh deer is listed as Vulnerable on the Red List of the IUCN. Three populations of the species from three areas in the Parana River basin (between the states of Sao Paulo and Mato Grosso do Sul) were recently studied by observing protein polymorphism at 17 loci (Oliveira et al. 2005). Now we are presenting data about isolation of microsatellite markers to improve the results regarding population structure.

Rethinking the development, dissemination and adoption of agricultural technologies

This paper focuses on the higher order factors affecting successful adoption of technologies. Drawing on the "actor-oriented perspective" in rural sociology, it is argued that successful examples of adoption at this higher level result from a complex conjunction of people and events, with outcomes that may have been quite unanticipated at the outset. From this perspective, research and extension projects and programs are viewed as arenas in which social actors–village leaders, farmers, researchers (local and international), aid officials, municipal agents, extension workers, and traders–pursue their own short- and long-term objectives and strategies. To this end, they maneuver, negotiate, organize, cooperate, participate, coerce, obstruct, form coalitions, adopt, adapt, and reject, all within a specific geographical and historical context.

Preimplantation development and expression of Hsp-70 and Bax genes in bovine blastocysts derived from oocytes matured in alpha-MEM supplemented with growth factors and synthetic macromolecules

In vitro culture conditions affect both the maternal and embryonic expression of genes and is likely to alter both oocyte and embryo developmental competence. The search for better and less variable culture conditions simulating those in vivo has led to the development of defined culture media, with lower impact on the molecular reprogramming of oocytes and embryos. We evaluated embryo development and relative abundance (RA) of Hsp-70 and Bax transcripts in bovine blastocysts produced from oocytes matured in a chemically defined IVM system with synthetic polymers. Immature cumulus oocyte complexes (COCs) were matured for 22-24 h in alpha-MEM supplemented with IGF-1, insulin, 0.1% polyvinyl alcohol (PVA), or 0.1% polyvinylpyrrolidone (PVP), but without FSH or LH. The control group consisted of COCs matured it, TCM plus FSH and 10% estrous cow serum. After fertilization. presumptive zygotes were co-cultured with cumulus cells until 224 h post-insemination. Total RNA was isolated from embryo pools, reverse transcribed into cDNA, and subjected to transcript analysis by real-time PCR. Cleavage rate was higher (P < 0.05) for the control group (68.3%) than for the PVA (54.4%) and PVP-40 (58.3%) groups. Nevertheless. there was no difference among the PVA, PVP-40 and control groups in blastocyst or hatching rates. similarly, no difference in relative abundance of Hsp-70 and Bax transcripts was detected in comparison to the control group. We inferred that bovine oocytes can be matured in serum- and gonadotrophin-free medium supplemented with PVA or PVP, enriched with IGF-I and insulin, without altering post-cleavage development and relative abundance of some genes associated with stress and apoptosis. (C) 2009 Elsevier Inc. All rights reserved.