73 research outputs found

    An exploratory study of short-term camping in Antarctica: Hormonal and mood states changes

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    Long-term Antarctic expedition’s studies indicated harmful or positive behavioral and psychophysiological adaptive changes that arise from adversities in isolated, confined, and extreme environments. Whereas most of the published studies focused on overwintering situations, most Brazilian Antarctic Program summer expeditions consist of short-term stays. We evaluated the influence of a permanence in Antarctic short-term (13-day) summer camp on the hormonal responses and mood states in eight volunteers. Data collection was carried out at the beginning (initial measure, days 3 to 5) and the end (final measurement, days 10 to 12) of the camping. Morning and evening samples of saliva were obtained to measure the testosterone and cortisol concentrations. Morning blood drops were used to determine thyroid-stimulating hormone (TSH) and thyroxine (T4) concentration. The volunteers also answered a mood states questionnaire. During the short-term camp, T4 (3.92 ± 0.75 vs 2.21 ± 0.71 ÎŒg.dL-1) and T4/TSH (3.16 ± 0.97 vs 1.79 ± 0.74 AU) reduced, without concomitant changes in TSH (1.28 ± 0.17 vs 1.30 ± 0.09 ÎŒU.mL-1), and salivary cortisol increased (2,392 ± 1,153 vs 4,440 ± 1,941 pg.mL-1) resulting in greater cortisol amplitude (calculated from the difference between morning and evening measurement, 1,400 ± 1,442 vs 3,230 ± 2,046). In men, testosterone increased as well (26.2 ± 12.5 vs 67.8 ± 45.8, all differences with P<0.05). There was a moderate effect in mood states evidenced by increased anger and fatigue, and reduced vigor. At the end of the camp, the change in cortisol correlated with anger, and the final cortisol values with anger and tension. We concluded that staying in a short-term summer camp in Antarctica induced endocrine and mood state changes, indicators of stress reaction

    Protective Effect of Lactobacillus diolivorans 1Z, Isolated From Brazilian Kefir, Against Salmonella enterica Serovar Typhimurium in Experimental Murine Models

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    Kefir is a beverage obtained by fermentation of milk or sugar solution by lactic acid bacteria and yeasts, and several health benefits have been attributed to its ingestion, part of them being attributed to Lactobacillus species. The objective of the present study was to evaluate, in vivo, the probiotic potential of Lactobacillus diolivorans 1Z, isolated from Brazilian kefir grains. Initially, conventional mice were orally treated daily or not during 10 days with a suspension of L. diolivorans 1Z, and then orally challenged with Salmonella enterica serovar Typhimurium. Treatment with L. diolivorans 1Z resulted in higher survival (70%) of animals after the challenge with the pathogen than for not treated mice (0%). When germ-free mice were monoassociated (GN-PS group) or not (GN-CS group) with L. diolivorans 1Z and challenged after 7 days with S. Typhimurium, Salmonella fecal counts were significantly lower (P < 0.05) for the GN-PS group when compared to the GN-CS group. Histopathological analysis revealed less damage to the ileum mucosa, as demonstrated by smallest perimeter of major lesions for mice of the GN-PS group in comparison to the group GN-CS (P < 0.05). These findings were accompanied by a lower expression of IFN-Îł and TNF-α in the intestinal tissue of GN-PS mice. Additionally, translocation of S. Typhimurium to liver was significantly lower in GN-PS than in GN-CS mice (P < 0.05), and IgA levels in intestinal content and number of Kupffer cells in liver were higher. No difference was observed for hepatic cellularity between GN-PS and GN-CS groups (P > 0.05), but the pattern of inflammatory cells present in the liver was predominantly of polymorphonuclear in GN-CS group and of mononuclear in the GN-PS group, and a higher hepatic expression of IL-10 and TGF-ÎČ was observed in GN-PS group. Concluding, L. diolivorans 1Z showed to be a potential probiotic strain that protected mice from death after challenge with S. Typhimurium, apparently by immunological modulation

    Differential brain and spinal cord cytokine and BDNF levels in experimental autoimmune encephalomyelitis are modulated by prior and regular exercise

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    The interactions between a prior program of regular exercise and the development of experimental autoimmune encephalomyelitis (EAE)-mediated responses were evaluated. in the exercised EAE mice, although there was no effect on infiltrated cells, the cytokine and derived neurotrophic factor (BDNF) levels were altered, and the clinical score was attenuated. Although, the cytokine levels were decreased in the brain and increased in the spinal cord, BDNF was elevated in both compartments with a tendency of lesser demyelization volume in the spinal cord of the exercised EAE group compared with the unexercised. (C) 2013 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)NIHUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Fisiol & Biofis, Nucleo Neurociencias, BR-31270901 Belo Horizonte, MG, BrazilMinist Educ Brazil, CAPES Fdn, Programa Pos Grad Ciencias Biol Fisiol Farmacol, BR-70040020 Brasilia, DF, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Patol, BR-31270901 Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04023062 São Paulo, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Bioquim & Imunol, Lab Venenos & Toxinas Anim, BR-31270901 Belo Horizonte, MG, BrazilUniv Miami, Miller Sch Med, Miami Project Cure Paralysis, Miami, FL 33136 USALa Trobe Univ, Dept Biochem, Bundoora, Vic 3086, AustraliaUniversidade Federal de São Paulo, Dept Biofis, BR-04023062 São Paulo, BrazilCAPES: BEX 0020/12-5NIH: NS051709NIH: NS065479FAPEMIG: CBB-APQ-01459-10FAPEMIG: PPM-00200-12Web of Scienc

    Characterization of Chronic Cutaneous Lesions from TNF-Receptor-1-Deficient Mice Infected by Leishmania major

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    Leishmania major-infected TNF receptor 1 deficient (TNFR1 KO) mice resolve parasitism but fail to resolve lesions, while wild-type mice completely heal. We investigated the cell composition, cytokine production, and apoptosis in lesions from L. major-infected TNFR1 KO and wild-type (WT) mice. Chronic lesions from L. major-infected TNFR1 KO mice presented larger number of CD8+ T and Ly6G+ cells. In addition, higher concentrations of mRNA for IFN-Îł CCL2 and CCL5, as well as protein, but lower numbers of apoptotic cells, were found in lesions from TNFR1 KO mice than in WT, at late time points of infection. Our studies showed that persistent lesions in L. major-infected TNFR1 KO mice may be mediated by continuous migration of cells to the site of inflammation due to the presence of chemokines and also by lower levels of apoptosis. We suggest that this model has some striking similarities to the mucocutaneous clinical form of leishmaniasis

    Coinfection with Different Trypanosoma cruzi Strains Interferes with the Host Immune Response to Infection

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    A century after the discovery of Trypanosoma cruzi in a child living in Lassance, Minas Gerais, Brazil in 1909, many uncertainties remain with respect to factors determining the pathogenesis of Chagas disease (CD). Herein, we simultaneously investigate the contribution of both host and parasite factors during acute phase of infection in BALB/c mice infected with the JG and/or CL Brener T. cruzi strains. JG single infected mice presented reduced parasitemia and heart parasitism, no mortality, levels of pro-inflammatory mediators (TNF-α, CCL2, IL-6 and IFN-γ) similar to those found among naïve animals and no clinical manifestations of disease. On the other hand, CL Brener single infected mice presented higher parasitemia and heart parasitism, as well as an increased systemic release of pro-inflammatory mediators and higher mortality probably due to a toxic shock-like systemic inflammatory response. Interestingly, coinfection with JG and CL Brener strains resulted in intermediate parasitemia, heart parasitism and mortality. This was accompanied by an increase in the systemic release of IL-10 with a parallel increase in the number of MAC-3+ and CD4+ T spleen cells expressing IL-10. Therefore, the endogenous production of IL-10 elicited by coinfection seems to be crucial to counterregulate the potentially lethal effects triggered by systemic release of pro-inflammatory mediators induced by CL Brener single infection. In conclusion, our results suggest that the composition of the infecting parasite population plays a role in the host response to T. cruzi in determining the severity of the disease in experimentally infected BALB/c mice. The combination of JG and CL Brener was able to trigger both protective inflammatory immunity and regulatory immune mechanisms that attenuate damage caused by inflammation and disease severity in BALB/c mice

    Virulence in Murine Model Shows the Existence of Two Distinct Populations of Brazilian Vaccinia virus Strains

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    Brazilian Vaccinia virus had been isolated from sentinel mice, rodents and recently from humans, cows and calves during outbreaks on dairy farms in several rural areas in Brazil, leading to high economic and social impact. Some phylogenetic studies have demonstrated the existence of two different populations of Brazilian Vaccinia virus strains circulating in nature, but little is known about their biological characteristics. Therefore, our goal was to study the virulence pattern of seven Brazilian Vaccinia virus strains. Infected BALB/c mice were monitored for morbidity, mortality and viral replication in organs as trachea, lungs, heart, kidneys, liver, brain and spleen. Based on the virulence potential, the Brazilian Vaccinia virus strains were grouped into two groups. One group contained GP1V, VBH, SAV and BAV which caused disease and death in infected mice and the second one included ARAV, GP2V and PSTV which did not cause any clinical signals or death in infected BALB/c mice. The subdivision of Brazilian Vaccinia virus strains into two groups is in agreement with previous genetic studies. Those data reinforce the existence of different populations circulating in Brazil regarding the genetic and virulence characteristics
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