Microbial processes and bacterial populations associated to anaerobic treatment of sulfate-rich wastewater

A pilot-scale (1.2 m(3)) anaerobic sequencing batch biofilm reactor (ASBBR) containing mineral coal for biomass attachment was fed with sulfate-rich wastewater at increasing sulfate concentrations. Ethanol was used as the main organic source. Tested COD/sulfate ratios were of 1.8 and 1.5 for sulfate loading rates of 0.65-1.90 kgSO(4)(2-)/cycle (48 h-cycle) or of 1.0 in the trial with 3.0 gSO(4)(2-) l(-1). Sulfate removal efficiencies observed in all trials were as high as 99%. Molecular inventories indicated a shift on the microbial composition and a decrease on species diversity with the increase of sulfate concentration. Beta-proteobacteria species affiliated with Aminomonas spp. and Thermanaerovibrio spp. predominated at 1.0 gSO(4)(2-) l(-1). At higher sulfate concentrations the predominant bacterial group was Delta-proteobacteria mainly Desulfovibrio spp. and Desulfomicrobium spp. at 2.0 gSO(4)(2-) l(-1), whereas Desulfurella spp. and Coprothermobacter spp. predominated at 3.0 gSO(4)(2-) l(-1). These organisms have been commonly associated with sulfate reduction producing acetate, sulfide and sulfur. Methanogenic archaea(Methanosaeta spp.)was found at 1.0 and 2.0 gSO(4)(2-) l(-1). Additionally, a simplified mathematical model was used to infer on metabolic pathways of the biomass involved in sulfate reduction. (C) 2009 Elsevier Ltd. All rights reserved.

The treatment of sulfate-rich wastewater using an anaerobic sequencing batch biofilm pilot-scale reactor

This paper presents the results from 92 cycles of an anaerobic sequencing batch biofilm reactor containing biomass immobilized on inert support (mineral coal) applied for the treatment of an industrial wastewater containing high sulfate concentration. The pilot-scale reactor, with a total volume of 1.2 m(3), was operated at sulfate loading rates ranging from 0.15 to 1.90 kgSO(4)(2-)/cycle (48 It - cycle) corresponding to sulfate concentrations of 0.25 to 3.0 gSO(4)(2-) l(-1). Domestic sewage and ethanol were utilized as electron donors for sulfate reduction. Influent sulfate concentrations were increased in order to evaluate the minimum COD/sulfate ratio at which high reactor performance could be maintained. The mean sulfate removal efficiency remained between the range of 88 to 92% at several sulfate concentrations. Temporal profiles along the 48 h cycles were carried out under stable operation at sulfate concentrations of 1.0, 2.0 and 3.0 gSO(4)(2-) l(-1). Sulfate removal reached 99% for cycle times of 15, 25, and 30 h, and the effluents sulfate concentrations were lower than 8 mgSO(4)(2-) l(-1). The results demonstrate the potential applicability of the anaerobic configuration for the biological treatment of sulfate-rich wastewaters. (C) 2009 Elsevier B.V. All rights reserved.

Anaerobic treatment of sulfate-rich wastewater in an anaerobic sequential batch reactor (AnSBR) using butanol as the carbon source

Biological sulfate reduction was studied in a laboratory-scale anaerobic sequential batch reactor (14 L) containing mineral coal for biomass attachment. The reactor was fed industrial wastewater with increasingly high sulfate concentrations to establish its application limits. Special attention was paid to the use of butanol in the sulfate reduction that originated from melamine resin production. This product was used as the main organic amendment to support the biological process. The reactor was operated for 65 cycles (48 h each) at sulfate loading rates ranging from 2.2 to 23.8 g SO(4)(2-)/cycle, which corresponds to sulfate concentrations of 0.25, 0.5,1.0, 2.0 and 3.0 g SW(4)(2-)L(-1). The sulfate removal efficiency reached 99% at concentrations of 0.25, 0.5 and 1.0 g SO(4)(2-)L(-1). At higher sulfate concentrations (2.0 and 3.0 g SO(4)(2-)L(-1)), the sulfate conversion remained in the range of 71-95%. The results demonstrate the potential applicability of butanol as the carbon source for the biological treatment of sulfate in an anaerobic batch reactor. (C) 2011 Elsevier Ltd. All rights reserved.

Brain nitric oxide production by a proline-rich decapeptide from Bothrops jararaca venom improves baroreflex sensitivity of spontaneously hypertensive rats

Baroreflex sensitivity is disturbed in many people with cardiovascular diseases such as hypertension. Brain deficiency of nitric oxide (NO), which is synthesized by NO synthase (NOS) in the citrulline-NO cycle (with argininosuccinate synthase (ASS) activity being the rate-limiting step), contributes to impaired baroreflex. We recently showed that a decapeptide isolated from Bothrops jararaca snake venom, denoted Bj-PRO-10c, exerts powerful and sustained antihypertensive activity. Bj-PRO-10c promoted vasodilatation dependent on the positive modulation of ASS activity and NO production in the endothelium, and also acted on the central nervous system, inducing the release of GABA and glutamate, two important neurotransmitters in the regulation of autonomic systems. We evaluated baroreflex function using the regression line obtained by the best-fit points of measured heart rate (HR) and mean arterial pressure (MAP) data from spontaneously hypertensive rats (SHRs) treated with Bj-PRO-10c. We also investigated molecular mechanisms involved in this effect, both in vitro and in vivo. Bj-PRO-10c mediated an increase in baroreflex sensitivity and a decrease in MAP and HR. The effects exerted by the peptide include an increase in the gene expression of endothelial NOS and ASS. Bj-PRO-10c-induced NO production depended on intracellular calcium fluxes and the activation of a G(i/o)-protein-coupled metabotropic receptor. Bj-PRO-10c induced NO production and the gene expression of ASS and endothelial NOS in the brains of SHRs, thereby improving baroreflex sensitivity. Bj-PRO-10c may reveal novel approaches for treating diseases with impaired baroreflex function. Hypertension Research (2010) 33, 1283-1288; doi: 10.1038/hr.2010.208

Paclitaxel associated with cholesterol-rich nanoemulsions promotes atherosclerosis regression in the rabbit

A cholesterol-rich nanoemulsion (LDE) that resembles LDL binds to the LDL receptors and after injection into the blood stream may concentrate in cells with LDL receptor overexpression, as occurs in neoplasias and other proliferative processes. Thus, LDE can be used as vehicle to target drugs against those cells. The current study was designed to verify in rabbits whether LDE concentrates in the lesioned rabbit artery and whether a paclitaxel derivative, paclitaxel oleate, associated to LDE could reduce the atherosclerotic lesions. Sixteen male New Zealand rabbits were fed a 1% cholesterol diet for 60 days. Starting from day 30 under cholesterol feeding, eight animals were treated with four weekly intravenous injections of LDE-paclitaxel (4 mg/kg) and eight with four weekly intravenous saline solution injections for additional 30 days. On day 60, the animals were sacrificed for analysis. The uptake of LDE labeled with [C-14]-cholesteryl oleate by the aortic arch of cholesterol-fed rabbits was twice as much that observed in animals fed only regular chow. LDE-paclitaxel reduced the lesion areas of cholesterol-fed animals by 60% and intima-media ratio fourfold and inhibited the macrophage migration and the smooth muscle cell proliferation and invasion of the intima. LDE-paclitaxel treatment had no toxicity. In conclusion, LDE-paclitaxel produced pronounced atherosclerosis regression without toxicity and has shown remarkable potential in cardiovascular therapeutics. (c) 2008 Published by Elsevier Ireland Ltd.

Organocatalytic asymmetric aldol reactions mediated by a cysteine-derived prolinamide

In this Letter, a cysteine-derived prolinamide is described to act as a robust and effective organocatalyst for enantioselective aldol reactions. (c) 2008 Elsevier Ltd. All rights reserved.

Impact of adenosine nucleotide translocase (ANT) proline isomerization on Ca(2+)-induced cysteine relative mobility/mitochondrial permeability transition pore

Mitochondrial membrane carriers containing proline and cysteine, such as adenine nucleotide translocase (ANT), are potential targets of cyclophilin D (CyP-D) and potential Ca(2+)-induced permeability transition pore (PTP) components or regulators; CyP-D, a mitochondrial peptidyl-prolyl cis-trans isomerase, is the probable target of the PTP inhibitor cyclosporine A (CsA). In the present study, the impact of proline isomerization (from trans to cis) on the mitochondrial membrane carriers containing proline and cysteine was addressed using ANT as model. For this purpose, two different approaches were used: (i) Molecular dynamic (MD) analysis of ANT-Cys(56) relative mobility and (ii) light scattering techniques employing rat liver isolated mitochondria to assess both Ca(2+)-induced ANT conformational change and mitochondrial swelling. ANT-Pro(61) isomerization increased ANT-Cys(56) relative mobility and, moreover, desensitized ANT to the prevention of this effect by ADP. In addition, Ca(2+) induced ANT ""c"" conformation and opened PTP; while the first effect was fully inhibited, the second was only attenuated by CsA or ADP. Atractyloside (ATR), in turn, stabilized Ca(2+)-induced ANT ""c"" conformation, rendering the ANT conformational change and PTP opening less sensitive to the inhibition by CsA or ADP. These results suggest that Ca(2+) induces the ANT ""c"" conformation, apparently associated with PTP opening, but requires the CyP-D peptidyl-prolyl cis-trans isomerase activity for sustaining both effects.

Dermaseptin 01 as antimicrobial peptide with rich biotechnological potential: study of peptide interaction with membranes containing Leishmania amazonensis lipid-rich extract and membrane models

This article addresses the interactions of the synthetic antimicrobial peptide dermaseptin 01 (GLWSTIKQKGKEAAIAAA-KAAGQAALGAL-NH(2), DS 01) with phospholipid (PL) monolayers comprising (i) a lipid-rich extract of Leishmania amazonensis (LRE-La), (ii) zwitterionic PL (dipalmitoylphosphatidylcholine, DPPC), and (iii) negatively charged PL (dipalmitoylphosphatidylglycerol, DPPG). The degree of interaction of DS 01 with the different biomembrane models was quantified from equilibrium and dynamic liquid-air interface parameters. At low peptide concentrations, interactions between DS 01 and zwitterionic PL, as well as with the LRE-La monolayers were very weak, whereas with negatively charged PLs the interactions were stronger. For peptide concentrations above 1 mu g/ml, a considerable expansion of negatively charged monolayers occurred. In the case of DPPC, it was possible to return to the original lipid area in the condensed phase, suggesting that the peptide was expelled from the monolayer. However, in the case of DPPG, the average area per lipid molecule in the presence of DS 01 was higher than pure PLs even at high surface pressures, suggesting that at least part of DS 01 remained incorporated in the monolayer. For the LRE-La monolayers, DS 01 also remained in the monolayer. This is the first report on the antiparasitic activity of AMPs using Langmuir monolayers of a natural lipid extract from L. amazonensis. Copyright (C) 2011 European Peptide Society and John Wiley & Sons, Ltd.

Metabolic syndrome features small, apolipoprotein A-I-poor, triglyceride-rich HDL3 particles with defective anti-apoptotic activity

The metabolic syndrome (MetS) phenotype is typically characterized by visceral obesity, insulin resistance, atherogenic dyslipidemia involving hypertriglyceridemia and subnormal levels of high density lipoprotein-cholesterol (HDL-C), oxidative stress and elevated cardiovascular risk. The potent antioxidative activity of small HDL3 is defective in MetS [Hansel B, et al. J Clin Endocrinol Metab 2004;89:4963-71]. We evaluated the functional capacity of small HDL3 particles from MetS subjects to protect endothelial cells from apoptosis induced by mildly oxidized low-density lipoprotein (oxLDL). MetS subjects presented an insulin-resistant obese phenotype, with hypertriglyceridemia, elevated apolipoprotein B and insulin levels, but subnormal HDL-C concentrations and chronic low grade inflammation (threefold elevation of C-reactive protein). When human microvascular endothelial cells (HMEC-1) were incubated with oxLDL (200 jig apolipoprotein B/ml) in the presence or absence of control HDL subfiractions (25 mu g protein/ml), small, dense HDL3b and 3c significantly inhibited cellular annexin V binding and intracellular generation of reactive oxygen species. The potent anti-apoptotic activity of small HDL3c particles was reduced (-35%; p < 0.05) in MetS subjects (n = 16) relative to normolipidemic controls (n = 7). The attenuated anti-apoptotic activity of HDL3c correlated with abdominal obesity, atherogenic dyslipidemia and systemic oxidative stress (p < 0.05), and was intimately associated with altered physicochemical properties of apolipoprotein A-I (apoA-I-poor HDL3c, involving core cholesteryl ester depletion and triglyceride enrichment. We conclude that in MetS, apoA-I-poor, small, dense HDL3c exert defective protection of endothelial cells from oxLDL-induced apoptosis, potentially reflecting functional anomalies intimately associated with abnormal neutral lipid core content. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Development of a synthetic 7-ketocholesterol- rich emulsion resembling chylomicrons

Lipid emulsions that mimic natural lipoproteins help to understand the metabolism and the constitutional organization of circulating lipids. Chylomicrons synthesised by enterocyte cells usually contain oxysterols such as 7-ketocholesterol (7-KC). Here we describe the development of a 7-KC-containing emulsion as a model for oxisterol-rich chylomicron. Different amounts of 7-KC were used. Emulsion characteristics as effective diameter, lipid saturation with radiolabeled lipids was evaluated. In conclusion, the production of a synthetic 7-KC-rich emulsion resembling hylomicrons was feasible, being a model for in vivo metabolism studies.

Markers of vascular differentiation, proliferation and tissue remodeling in juvenile nasopharyngeal angiofibromas

Juvenile nasopharingeal angiofibroma (JNA) is a histologically benign locally aggressive tumor characterized by irregular vessels embedded. in a fibrous stroma. Excessive vascularity results in bleeding complications, and the inhibition of angiogenesis is a promising strategy for managing extensive JNA tumors. To better characterize the endothelial components of JNA, we aimed to evaluate markers of vascular differentiation and proliferation, such as friend leukemia integration-1 (FLI-1) and endoglin, lymphatic markers, including podoplanin and vascular endothelial growth factor receptor 3 (VEGFR3) and its cognate ligand VEGFC, GLUT-1, a diagnostic marker that discriminates between hemangiomas and vascular malformations, and two markers of tissue remodeling, stromelysin 3 (ST3) and secreted acid protein rich in cysteine (SPARC). Antigens were assessed immunohistochemically in vessels and stromal cells of JNA archival cases (n=22). JNA endothelial cells were positive for endoglin, VEGFC and FLI-1, whereas podoplanin and VEGFR3 were negative in all cases. Both endothelial cells and fibroblasts stained for ST3 and SPARC. GLUT-1 was investigated in JNA cases, in infantile hemangiomas (n=123) and in vascular malformations (n=135) as controls. JNAs and vascular malformations were GLUT-1-negative, while hemangiomas showed positive staining. The presence of markers of endothelial differentiation and proliferation highlighted the hyper-proliferative state of JNA vessels. The absence of podoplanin and VEGFR3 underscores their blood endothelial cell characteristic. The absence of GLUT-1 discriminates JNAs from hemangiomas. ST3 and SPARC up-regulation in endothelial cells and fibroblasts may contribute to a compensatory signaling for controlling angiogenesis. Some of these markers may eventually serve as therapeutic targets. Our results may aid in the understanding of JNA pathophysiology.

Metabolism of triglyceride-rich lipoproteins and lipid transfer to high-density lipoprotein in young obese and normal-weight patients with polycystic ovary syndrome

Objective: To clarify whether the metabolism of triglyceride-rich lipoproteins and lipid transfer to high-density lipoprotein (HDL) are altered in patients with polycystic ovary syndrome (PCOS). Design: Case control study. Setting: Endocrinology clinics. Patient(s): Eight normal-weight (NW) and 15 obese (013) patients with PCOS were compared with 10 NW and 10 Ob women without PCOS paired for age and body mass index. Intervention(s): Determination of triglyceride-rich lipoprotein metabolism and lipid transfer to HDL. Main Outcome Measure(s): Participants were injected triglyceride-rich emulsions labeled with (14)C-cholesteryl esters and (3)H-triglycerides and the fractional clearance rate (FCR, in min(-1)) of labels was determined. Lipid transfer from artificial nanoemulsions to HDL was performed by incubating radioactively labeled lipid nanoemulsions with plasma during 1 hour, followed by radioactive counting of HDL-containing supernatant after chemical precipitation. Result(s): Lipolysis estimated by triglyceride FCR was equal in PCOS groups (NW = 0.043 +/- 0.032, Ob = 0.033 +/- 0.009) and respective controls (NW = 0.039 +/- 0.015, Ob = 0.044 +/- 0.019). However, the remnant removal as estimated by cholesteryl ester FCR was reduced in both PCOS groups (NW = 0.005 +/- 0.006, Ob = 0.005 +/- 0.005) compared with controls (NW = 0.016 +/- 0.006, Ob = 0.011 +/- 0.072). Lipid transfer rates were not different among groups, but triglyceride transfer rates were positively correlated with homeostasis model assessment estimate of insulin resistance in PCOS. Conclusion(s): PCOS patients showed decreased removal of atherogenic remnants even when fasting glucose was <100 mg/dL. This reinforces the usefulness of the measures taken to prevent cardiovascular events in PCOS patients. (Fertil Steril (R) 2010;93:1948-56. (C)2010 by American Society for Reproductive Medicine.)

Homocysteine and cysteine concentrations are modified by recent exposure to environmental air pollution in Sao Paulo, Brazil

Millions of people worldwide are affected by anthropogenic air pollution derived from the combustion of fossil fuels. In this work, we tested the effects of fetal, lactation and post-weaning ambient air pollution exposure on total homocysteine (tHcy) concentrations and on a downstream pathway element, the plasma cysteine (Cys) concentration. Two similar exposure chambers (polluted and filtered chamber) were located near an area with heavy traffic in Sao Paulo, Brazil, and male Swiss mice were housed there from the pre-natal period until 3 months of age. Groups during fetal, lactation and adult periods of exposure were apportioned, and tHcy and Cys plasma concentrations were assessed when the animals were 3 months old. In our study, both the tHcy and Cys concentrations were decreased in groups that spent their final stage of life in polluted chambers, suggesting recent alterations in tHcy and Cys concentrations due to air pollution exposure. The possible relationship of these data with cardiovascular dysfunction is still a matter of controversy in animals; nevertheless, epigenetic mechanisms emerge as a possible issue to consider in the investigation of the link between air pollution and Hcy measurement. (C) 2009 Elsevier Inc. All rights reserved.

Global Analysis of Protein Palmitoylation in African Trypanosomes

Many eukaryotic proteins are posttranslationally modified by the esterification of cysteine thiols to long-chain fatty acids. This modification, protein palmitoylation, is catalyzed by a large family of palmitoyl acyltransferases that share an Asp-His-His-Cys Cys-rich domain but differ in their subcellular localizations and substrate specificities. In Trypanosoma brucei, the flagellated protozoan parasite that causes African sleeping sickness, protein palmitoylation has been observed for a few proteins, but the extent and consequences of this modification are largely unknown. We undertook the present study to investigate T. brucei protein palmitoylation at both the enzyme and substrate levels. Treatment of parasites with an inhibitor of total protein palmitoylation caused potent growth inhibition, yet there was no effect on growth by the separate, selective inhibition of each of the 12 individual T. brucei palmitoyl acyltransferases. This suggested either that T. brucei evolved functional redundancy for the palmitoylation of essential palmitoyl proteins or that palmitoylation of some proteins is catalyzed by a noncanonical transferase. To identify the palmitoylated proteins in T. brucei, we performed acyl biotin exchange chemistry on parasite lysates, followed by streptavidin chromatography, two-dimensional liquid chromatography-tandem mass spectrometry protein identification, and QSpec statistical analysis. A total of 124 palmitoylated proteins were identified, with an estimated false discovery rate of 1.0%. This palmitoyl proteome includes all of the known palmitoyl proteins in procyclic-stage T. brucei as well as several proteins whose homologues are palmitoylated in other organisms. Their sequences demonstrate the variety of substrate motifs that support palmitoylation, and their identities illustrate the range of cellular processes affected by palmitoylation in these important pathogens.

Prognostic value of NDRG1 and SPARC protein expression in breast cancer patients

An increasing number of studies have shown altered expression of secreted protein acidic and rich in cysteine (SPARC) and N-myc down-regulated gene (NDRG1) in several malignancies, including breast carcinoma; however, the role of these potential biomarkers in tumor development and progression is controversial. In this study, NDRG1 and SPARC protein expression was evaluated by immunohistochemistry on tissue microarrays containing breast tumor specimens from patients with 10 years of follow-up. NDRG1 and SPARC protein expression was determined in 596 patients along with other prognostic markers, such as ER, PR, and HER2. The status of NDRG1 and SPARC protein expression was correlated with prognostic variables and patient clinical outcome. Immunostaining revealed that 272 of the 596 cases (45.6%) were positive for NDRG1 and 431 (72.3%) were positive for SPARC. Statistically significant differences were found between the presence of SPARC and NDRG1 protein expression and standard clinicopathological variables. Kaplan-Meier analysis showed that NDRG1 positivity was directly associated with shorter disease-free survival (DFS, P < 0.001) and overall survival (OS, P < 0.001). In contrast, patients expressing low levels of SPARC protein had worse DFS (P = 0.001) and OS (P = 0.001) compared to those expressing high levels. Combined analysis of the two markers indicated that DFS (P < 0.001) and OS rates (P < 0.001) were lowest for patients with NDRG1-positive and SPARC-negative tumors. Furthermore, NDRG1 over-expression and SPARC down-regulation correlated with poor prognosis in patients with luminal A or triple-negative subtype breast cancer. On multivariate analysis using a Cox proportional hazards model, NDRG1 and SPARC protein expression were independent prognostic factors for both DFS and OS of breast cancer patients. These data indicate that NDRG1 over-expression and SPARC down-regulation could play important roles in breast cancer progression and serve as useful biomarkers to better define breast cancer prognosis.