Luiz F. Rodrigues

Mycobacterial heat shock protein 70 induces interleukin-10 production: immunomodulation of synovial cell cytokine profile and dendritic cell maturation

Cytokines are key modulators of the immune responses that take place in the inflamed synovium of arthritis patients. Consequently, substances that can reverse the inflammatory profile of the inflamed joint are potential tools for clinical management of the disease. Mycobacterial heat shock protein 70 (MTBHSP70) has been found to protect rats from experimentally induced arthritis through the induction of interleukin (IL)‐10‐producing T cells. In this study, we have demonstrated that MTBHSP70 induces IL‐10 production in synoviocytes from arthritis patients and peripheral blood monoculear cells (PBMCs) from both patients and healthy controls. IL‐10 production was accompanied by a decrease in tumour necrosis factor (TNF)‐α production by synovial cells. Separation studies showed that the target cells were mainly monocytes. Accordingly, we observed that MTBHSP70 delayed maturation of murine bone marrow‐derived dendritic cells. Our results suggest that MTBHSP may act on antigen‐presenting cells (APCs) to modulate the cytokine response in arthritis and support an anti‐inflammatory role for this protein, suggesting that it may be of therapeutic use in the modulation of arthritis.

Mycobacterium tuberculosis heat-shock protein 70 impairs maturation of dendritic cells from bone marrow precursors, induces interleukin-10 production and inhibits T-cell proliferation in vitro

In different inflammatory disease models, heat‐shock proteins (hsp) and hsp‐derived peptides have been demonstrated to possess anti‐inflammatory properties. While some studies have shown that hsp can directly interact with antigen‐presenting cells, others report that bacterial hsp can induce specific T cells with regulatory phenotypes. Effective characterization of the immunomodulatory effects of hsp 70, however, has historically been confounded by lipopolysaccharide (LPS) contamination. In this study, we compared the effects of LPS‐free Mycobacterial tuberculosis hsp 70 (TBhsp70) and its possible contaminants on dendritic cells (DC). We demonstrate herein that LPS‐free TBhsp70 inhibits murine DC maturation in vitro, while LPS‐contaminated TBhsp70 induces DC maturation. Mock recombinant preparations have no effect. In contrast to LPS, TBhsp70 does not induce tumour necrosis factor‐α production by DC, but interleukin‐10. In vivo, only LPS‐contaminated TBhsp70 induces up‐regulation of CD86 in splenic mature DC. Finally, TBhsp70 inhibited phytohaemagglutinin‐induced T‐cell proliferation. Our results support the hypothesis that TBhsp70 does not have inflammatory potential, but rather has immunosuppressive properties.

IL-21 and IL-15 cytokine DNA augments HSV specific effector and memory CD8+ T cell response

The recurrence of lesions and transmission of Herpes simplex virus is dependent on the number and function of viral specific CD8(+) T cells, especially the memory T cells. The generation, turnover and set point of this cell population is maintained by different factors like exposure to antigen, cytokines and co-stimulatory molecules. However, the contribution of these factors in the generation and maintenance of the memory CD8(+) T cell population is still controversial, since it is not clear if homeostatic proliferation driven by cytokines can overcome T cell receptor (TCR) signaling. Since, interleukin 15 (IL-15) and interleukin 21 (IL-21) are cytokines implicated in homeostatic control of CD8(+) T cell pool, we constructed and used expression plasmids coding for IL-15 (pIL-15) and IL-21 (pIL-21) to expand HSV specific CD8(+) T cells in an animal model. Our results showed that the IL-21 increased the frequency of CD8(+) T cells in the absence of antigen, although the magnitude of this response was dependent on TCR signaling. Both pIL-15 and pIL-21 boosted the numbers of antigen specific CD8(+) IFNgamma producing cells in the primary response. In the memory phase, numbers of CD8(+) CD44(high) as well as CD8(+) T cells producing IFN-gamma and TNF-alpha were increased when pIL-15 and pIL-21 were used alone or in combination, compared to vector treatment only, and association of antigen further increased the proliferative response. Our data suggest that genetic treatment with pIL-15 and pIL-21 in the presence or absence of cognate antigen can contribute to immune-enhancement against HSV.

Determination of trace elements in raw material for polyurethane production using direct sampling graphite furnace atomic absorption spectrometry

The concentration of Fe, Mg, Mn and Na at ultra-trace levels was determined in polymeric diphenylmethane dianiline, a raw material for polyurethane production, by direct sampling graphite furnace atomic absorption spectrometry (DS-GFAAS). A Zeeman-effect background correction system operated in 2-field or 3-field dynamic modes was used. Calibration was carried out using aqueous reference solutions and a sample mass between 0.5 and 35 mg was used. The relative standard deviation was calculated after successive measurements (number of replicates was 14 to 23 throughout the range of sample mass) and was below 15%. Blank values obtained using DS-GFAAS were lower than those obtained with other evaluated procedures. The accuracy was evaluated by comparison of the results with those obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave assisted digestion (MAD) in closed vessels and microwave-induced combustion (MIC). There were no statistical differences (confidence level 95%) between the results obtained for the analysis of all the analytes by DS-GFAAS and those obtained by ICP-OES after MAD and MIC. The limits of detection were considerably lower (0.06 to 0.27 ng g−1) in comparison with those obtained by ICP-OES after MAD (35 to 5443 ng g−1) and MIC (12 to 4890 ng g−1).

Fluid Seepage in Relation to Seabed Deformation on the Central Nile Deep-Sea Fan, Part 2: Evidence from Multibeam and Sidescan Imagery

On the central Nile deep-sea fan, stratified sediments overlying mass-transport deposits (MTDs) are deformed into slope-parallel seabed undulations associated with fluid seepage. The western part of this system, in water depths of 1,950–2,250 m, is examined using multi-frequency data from hull-mounted and deep-towed swath/profiling systems. Sub-bottom profiles show sub-vertical fluid pipes that terminate both at and below seabed, and gas signatures along fault planes bounding the undulations. Fluid seepage is recorded by high- to intermediate-backscatter patches (HBPs, IBPs) that differ in appearance on multibeam imagery (30 kHz, ≤3 m penetration) and sidescan swaths (170/190 kHz, <0.1 m penetration). Comparison of the two suggests a distinction of (a) buried carbonates (0.1–3 m), (b) broad near-seabed (<0.1 m) carbonate pavements elongate along the undulations, (c) sub-circular areas of seabed seepage up to 300 m across. Four of the latter have narrower gas flares at their edges rising 400–800 m above seabed. These results are consistent with an evolving system of narrow fluid conduits that support the growth and burial of carbonate pavements, shifting over millennial timescales along linear zones parallel to fault planes rooted in MTDs. Sediment deformation above MTDs is inferred to provide pathways for fluid escape, but migration of gas-rich fluids from depth is likely to have facilitated slope destabilisation.

Environmental monitoring of water resources around a municipal landfill of the Rio Grande do Sul state, Brazil

In Brazil, landfills are commonly used as a method for the final disposal of waste that is compliant with the legislation. This technique, however, presents a risk to surface water and groundwater resources, owing to the leakage of metals, anions, and organic compounds. The geochemical monitoring of water resources is therefore extremely important, since the leachate can compromise the quality and use of surface water and groundwater close to landfills. In this paper, the results of analyses of metals, anions, ammonia, and physicochemical parameters were used to identify possible contamination of surface water and groundwater in a landfill area. A statistical multivariate approach was used. The values found for alkali metals, nitrate, and chloride indicate contamination in the regional groundwater and, moreover, surface waters also show variation when compared to the other background points, mainly for ammonia. Thus, the results of this study evidence the landfill leachate influence on the quality of groundwater and surface water in the study area.

Environmental monitoring of a landfill area through the application of carbon stable isotopes, chemical parameters and multivariate analysis

Leachate produced during an organic matter decomposition process has a complex composition and can cause contamination of surface and groundwaters adjacent to a landfill area. The monitoring of these areas is extremely important for the characterization of the leachate produced and to avoid or mitigate environmental damages. Thus, the present study has the objective of monitoring the area of a Brazilian landfill using conventional parameters (dissolved metals and anions in water) and alternative, stable carbon isotopes parameters (δ13C of dissolved organic and inorganic carbons in water) in addition to multivariate analysis techniques. The use of conventional and alternative parameters together with multivariate analysis showed that cells of the residues are at different phases of stabilization of the organic matter and probably already at C3 of the methanogenic phase of decomposition. In addition, the data showed that organic matter stabilization ponds present in the landfill are efficient and improve the quality of the leachate. Enrichment of the heavy 13C isotope in both surface and groundwater suggested contamination in two sampling sites.

Comparative assessment between different sample preparation methodologies for PTGA CO2 adsorption assays—Pellet, powder, and fragment samples

The carbon dioxide sorption process at coal seams is very important for understanding the trapping mechanisms of carbon capture and storage. The gas retention capacity of coal seams can be estimated using indirect methods based on the adsorption/desorption isotherms obtained in the laboratory. However, the gas sorption capacity can be overestimated or underestimated depending on the sample preparation. This work evaluates different sample preparations and their theoretical adsorption capacity using coal samples from the Cambui coal field (Parana Basin), southern Brazil. Experiments using a thermogravimetric balance were done to calculate the theoretical adsorption capacity, while sample characterization was done through immediate analysis, elementary analysis, and mineralogical studies. The sample preparations used in this work were powder, pellets, and fragments. While the powder form presents an average behavior, without any experimental complication, the pellet is extremely sensitive to any variation in the sample preparation, such as fractures, and the fragment requires a much longer experiment time than the other sample preparations, being impracticable for some cases.

Exploratory Analysis of Sparkling Wines Based in the Combined Data of Stable Isotope Analysis with Physicochemical Variables and Volatile Profile

This work performs an exploratory analysis of the sparkling wines from the state of Rio Grande do Sul, Brazil. Samples of traditional sparkling wine and Moscatel sparkling wine were analyzed and chemometrics tools were applied to physicochemical, gas chromatography and stable carbon isotope analysis. The carbon isotope ratio (δC-CO2) of the samples presents great heterogeneity and confirm that the isotopic signature of the CO2 could be derived from the fermentation of C4 sugar. The principal component analysis (PCA) was capable to discriminate and classify the samples in their respective groups and combined data approach was especially important to identify the correlation between the studied variables. With the increasing production of sparkling wines in Brazil, this work helps to evaluate the standards of the local sparkling wines.