25 resultados para culture of inclusion


Relevância:

90.00% 90.00%

Publicador:

Resumo:

The present study investigates the use of solar heterogeneous photocatalyis (TiO2) for the destruction of [D-Leu]-Microcystin-LR, powerful toxin of widespread occurrence within cyanobacteria blooms. We extracted [D-Leu]-Microcystin-LR from a culture of Microcystis spp. and used a flat plate glass reactor coated with TiO2 (Degussa, P25) for the degradation studies. The irradiance was measured during the experiments with the aid of a spectroradiometer. After the degradation experiments, toxin concentrations were determined by HPLC and mineralization by TOC analyses. Acute and chronic toxicities were, quantified using mice and phosphatase inhibition in vitro assays, respectively. According to the performed experiments, 150 min were necessary to reduce the toxin concentration to the WHO's guideline for drinking water (from 10 to 1 mu g L-1) and to mineralize 90% of the initial carbon content. Another important finding is that solar heterogeneous photocatalysis was a destructive process indeed, not only for the toxin, but also for the other extract components and degradation products generated. Moreover, toxicity tests using mice have shown that the acute effect caused by the initial sample was removed. However, tests using the phosphatase enzyme indicated that it may be formed products capable of inducing chronic effects on mammals. The performed experiments indicate the feasibility of using solar heterogeneous photocatalysis for treating contaminated water with [D-Leu]-Microcystin-LR, not only due to its destruction, but also to the significant removal of organic matter and acute toxicity that can be achieved. (C) 2012 Elsevier Ltd. All rights reserved.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

In this investigation, the study of inclusion complexes formation between p-cymene and beta-cyclodextrin using the methods of physical mixture, paste (PC) and slurry (SC), was evaluated. The results of DSC and TG/DTG showed that the products prepared by PC and SC methods were able to incorporate greater amounts of p-cymene, as evidenced by the weight loss of 7.15 and 3.97%, respectively, which occurred between 120 and 270 A degrees C. SEM images showed decreased size of the household, especially in the SC product. The absorption bands in the IR spectrum, characteristic of p-cymene, were also identified in the preparations, indicating the presence of the compound in the complex.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Callogenesis, somatic embryogenesis, and regeneration were obtained from tissues of unfertilized ovaries of sweet orange (Citrus sinensis Osbeck.) cv. Tobias. The influence of two modified basal media, woody plant medium (WPM) and N6 medium, to induce callus formation from pistils was determined. Overall, high frequencies of callogenesis were observed when either medium was used. However, initial culture of explants in WPM medium followed by transfer of callus to N6 medium resulted in higher frequency of callus induction (of 2.30 callus per explant that were larger than 0.5 cm in size), and of subsequent development of embryogenic callus (10%). A total of 125 somatic embryos were obtained. After 6 months of culture, 72% of somatic embryos germinated into plantlets. These plantlets were subsequently micrografted in vitro, and then acclimatized. Ploidy of these plants were determined using flow cytometry and TRAPS molecular markers were used to confirm their maternal origin.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

In this article, it is proposed to differentiate political cultures in two dimensions. First, inspired by Habermas' distinction of the contents of discourse, a distinction is suggested between moral, ethical-political and pragmatic elements of political culture as well as of an element of culture of balancing interests. Second, inspired by Kohlberg's stage models for the development of the individual moral consciousness and for moral culture, a distinction is similarly suggested between two pre-conventional, two conventional and two post-conventional collective stages of political culture. It can be shown that from a normative point of view, only deliberations made in a post-conventional political culture can produce reasonable or at least fair results. Conceptual considerations indicate processes of direct democracy as the method for promoting post-conventional political cultures. The more liberty that the citizens have to formulate and trigger processes of direct democracy, the more one can expect from them to generate post-conventional political cultures.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The purpose of this study is to explore the mechanisms that influence decisions regarding outsourcing competencies in the operation of project management offices (PMOs). The exploratory research described here involves the use of a web-based survey for enterprises in Brazil. In 78 of the survey's valid cases, the PMO is operated using the organization's internal resources. A possible conclusion is that the PMO is unlikely to positively relate to the culture of external services used by the organization and to use outsourcing to operate the PMO.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

One hundred and twenty six piglets from a commercial genetic strain weaned at 21 days of age (6.11 +/- 0.42 kg) were used to evaluate the effects of supplementation levels of organic sources of trace minerals in the diets of weaned piglets on performance, occurrence of diarrhea, excretion of copper and zinc in the feces, and hematological parameters. A completely randomized block design was adopted, composed of six treatments (diets containing 100% of inorganic trace minerals premix at 3.00 kg/T; diets containing 0, 25, 50, 75 or 100% of organic trace minerals premix, equivalent to 0; 0.75; 1.50; 2.25 or 3.00 kg/T, respectively), seven replicates and three animals per plot. During the experimental period (from 21 to 63 days of age), the increasing levels of organic trace minerals premix in the diets determined a quadratic effect on daily weight gain (DWG), feed conversion (FC), percentage of hematocrit (Ht), hemoglobin (Hb), mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), platelets (Pt), and a linear increase of Cu and Zn concentrations in feces. The comparison of means between the treatment with inorganic trace minerals premix and the other treatments showed that piglets fed diets without trace minerals premix had lower values of DWG, Ht, Hb, MCH, MCV, Pt and the worst FC value of piglets fed diets containing 25% of organic trace minerals premix presented lower values of Ht and Hb, in comparison with those fed diets with 100% of inorganic trace minerals premix. Inorganic trace minerals premix can be substituted by organic trace minerals premix at a lower level of inclusion in diets for weaned piglets.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Background: Myocardium damage during Chagas' disease results from the immunological imbalance between pro-and production of anti-inflammatory cytokines and has been explained based on the Th1-Th2 dichotomy and regulatory T cell activity. Recently, we demonstrated that IL-17 produced during experimental T. cruzi infection regulates Th1 cells differentiation and parasite induced myocarditis. Here, we investigated the role of IL-17 and regulatory T cell during human Chagas' disease. Methodology/Principal Findings: First, we observed CD4(+)IL-17(+) T cells in culture of peripheral blood mononuclear cells (PBMC) from Chagas' disease patients and we evaluated Th1, Th2, Th17 cytokine profile production in the PBMC cells from Chagas' disease patients (cardiomyopathy-free, and with mild, moderate or severe cardiomyopathy) cultured with T. cruzi antigen. Cultures of PBMC from patients with moderate and severe cardiomyopathy produced high levels of TNF-alpha, IFN-gamma and low levels of IL-10, when compared to mild cardiomyopathy or cardiomyopathy-free patients. Flow cytometry analysis showed higher CD4(+)IL-17(+) cells in PBMC cultured from patients without or with mild cardiomyopathy, in comparison to patients with moderate or severe cardiomyopathy. We then analyzed the presence and function of regulatory T cells in all patients. All groups of Chagas' disease patients presented the same frequency of CD4(+)CD25(+) regulatory T cells. However, CD4(+)CD25(+) T cells from patients with mild cardiomyopathy or cardiomyopathy-free showed higher suppressive activity than those with moderate and severe cardiomyopathy. IFN-gamma levels during chronic Chagas' disease are inversely correlated to the LVEF (P = 0.007, r = -0.614), while regulatory T cell activity is directly correlated with LVEF (P = 0.022, r = 0.500). Conclusion/Significance: These results indicate that reduced production of the cytokines IL-10 and IL-17 in association with high levels of IFN-gamma and TNF-alpha is correlated with the severity of the Chagas' disease cardiomyopathy, and the immunological imbalance observed may be causally related with deficient suppressor activity of regulatory T cells that controls myocardial inflammation.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Background Transformed cells of Escherichia coli DH5-α with pGFPuv, induced by IPTG (isopropyl-β-d-thiogalactopyranoside), express the green fluorescent protein (gfpuv) during growth phases. E. coli subjected to the combination of selective permeation by freezing/thawing/sonication cycles followed by the three-phase partitioning extraction (TPP) method were compared to the direct application of TPP to the same culture of E. coli on releasing gfpuv from the over-expressing cells. Material and Methods Cultures (37°C/100 rpm/ 24 h; μ = 0.99 h-1 - 1.10 h-1) of transformed (pGFP) Escherichia coli DH5-α, expressing the green fluorescent protein (gfpuv, absorbance at 394 nm and emission at 509 nm) were sonicated in successive intervals of sonication (25 vibrations/pulse) to determine the maximum amount of gfpuv released from the cells. For selective permeation, the transformed previously frozen (-75°C) cells were subjected to three freeze/thaw (-20°C/ 0.83°C/min) cycles interlaid by sonication (3 pulses/ 6 seconds/ 25 vibrations). The intracellular permeate with gfpuv in extraction buffer (TE) solution (25 mM Tris-HCl, pH 8.0, 1 mM β-mercaptoethanol β-ME, 0.1 mM PMSF) was subjected to the three-phase partitioning (TPP) method with t-butanol and 1.6 M ammonium sulfate. Sonication efficiency was verified on the application to the cells previously treated by the TPP method. The intra-cell releases were mixed and eluted through methyl HIC column with a buffer solution (10 mM Tris-HCl, 10 mM EDTA, pH 8.0). Results The sonication maximum released amount obtained from the cells was 327.67 μg gfpuv/mL (20.73 μg gfpuv/mg total proteins – BSA), after 9 min of treatment. Through the selective permeation by three repeated freezing/thawing/sonication cycles applied to the cells, a close content of 241.19 μg gfpuv/mL (29.74 μg gfpuv/mg BSA) was obtained. The specific mass range of gfpuv released from the same cultures, by the three-phase partitioning (TPP) method, in relation to total proteins, was higher, between 107.28 μg/mg and 135.10 μg/mg. Conclusions The selective permeation of gfpuv by freezing/thawing/sonication followed by TPP separation method was equivalent to the amount of gfpuv extracted from the cells directly by TPP; although selective permeation extracts showed better elution through the HIC column.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Background: Aging is associated with complex and constant remodeling of the immune function, resulting in an increasing susceptibility to infection and others diseases. The infections caused by Gram-negative microorganisms, present in nursing homes and hospitals, constitute one of the most common infections in the elderly, and are mainly combated by innate immune cells. Although the functions of innate immunity seem more preserved during aging than of adaptive immune mechanisms, two systems operate in an integrated way in the body, so that injury in one part of the immune system inevitably affects the other as they are part of a defensive network. The aim of this study was to investigate the in vitro production of proinflammatory (TNF-α, IL-6, IL-1α, CXCL-8 and MCP-1) and antiinflammatory (TGF-α and IL-10) cytokines by monocytes, stimulated or not (basal) with lipopolysaccharide, from healthy young and elderly subjects. By means of PBMCs, we also studied if cytokine profile is altered in these different patient groups, in the presence of lymphocytes, under the same experimental conditions. Results: The monocytes from elderly presented higher basal production of TNF-α, MCP-1 and lower of TGF-α than young monocytes. PBMC showed similar cytokines production, irrespective age or stimulation presence. In the presence of lymphocytes, the spontaneous production of IL-10 was higher and of TGF-α was lower than monocytes, regardless of age. After LPS-stimulation, the presence of lymphocytes resulted in increased IL-6, IL-1α, MCP-1 and IL-10 and decreased CXCL-8 and TGF-α in comparison to pure culture of monocytes from young patients. With age, the same differences were observed, except for CXCL-8 and TGF-α which production was the same between monocytes and PBMC stimulated with LPS.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Abstract Background Plasmodium vivax merozoite surface protein-1 (MSP-1) is an antigen considered to be one of the leading malaria vaccine candidates. PvMSP-1 is highly immunogenic and evidences suggest that it is target for protective immunity against asexual blood stages of malaria parasites. Thus, this study aims to evaluate the acquired cellular and antibody immune responses against PvMSP-1 in individuals naturally exposed to malaria infections in a malaria-endemic area in the north-eastern Amazon region of Brazil. Methods The study was carried out in Paragominas, Pará State, in the Brazilian Amazon. Blood samples were collected from 35 individuals with uncomplicated malaria. Peripheral blood mononuclear cells were isolated and the cellular proliferation and activation was analysed in presence of 19 kDa fragment of MSP-1 (PvMSP-119) and Plasmodium falciparum PSS1 crude antigen. Antibodies IgE, IgM, IgG and IgG subclass and the levels of TNF, IFN-γ and IL-10 were measured by enzyme-linked immunosorbent assay. Results The prevalence of activated CD4+ was greater than CD8+ T cells, in both ex-vivo and in 96 h culture in presence of PvMSP-119 and PSS1 antigen. A low proliferative response against PvMSP-119 and PSS1 crude antigen after 96 h culture was observed. High plasmatic levels of IFN-γ and IL-10 as well as lower TNF levels were also detected in malaria patients. However, in the 96 h supernatant culture, the dynamics of cytokine responses differed from those depicted on plasma assays; in presence of PvMSP-119 stimulus, higher levels of TNF were noted in supernatant 96 h culture of malaria patient’s cells while low levels of IFN-γ and IL-10 were verified. High frequency of malaria patients presenting antibodies against PvMSP-119 was evidenced, regardless class or IgG subclass.PvMSP-119-induced antibodies were predominantly on non-cytophilic subclasses. Conclusions The results presented here shows that PvMSP-119 was able to induce a high cellular activation, leading to production of TNF and emphasizes the high immunogenicity of PvMSP-119 in naturally exposed individuals and, therefore, its potential as a malaria vaccine candidate.