Inflammatory markers in end-stage renal disease patients on haemodialysis

BackgroundCXC chemokine ligand 16 (CXCL16) is an inflammatory chemokine that mediates renal infiltration of macrophages and activated T cells. Aim: To investigate serum levels of CXCL16 in patients undergoing hemodialysis and their correlation with other inflammatory markers such as C-reactive protein (CRP) and intact parathyroid hormone (iPTH).MethodsThe study included 40 hemodialysis patients (22 males) and 40 age and gender-matched controls (24 males). Fasting blood sugar (FBS), urea, creatinine, calcium and inorganic phosphorous were assayed in participants using routine methods, glycosylated hemoglobin (HbA1c) by quantitative chromatographic spectrophotometry, iPTH by chemiluminescent microparticle immunoassay, CRP by nephelometry and CXCL16 by ELISA technique.ResultsSerum CXCL16, CRP, PTH, FBS, HbA1c, phosphorus, urea, and creatinine levels were significantly higher in hemodialysis patients compared to controls (p<0.00001). No statistically significant differences were observed between patients and controls for calcium. Serum CXCL16 levels correlated positively with CRP (r=0.956, p<0.00001) and iPTH (r=-0.403, p<0.001). Hemodialysis patients (diabetics or hypertensives) had significantly higher CXCL16 levels compared to non-diabetics or non-hypertensives.ConclusionsHigh levels of serum CXCL16, CRP and iPTH reflect the inflammatory status of hemodialysis patients and help avoid complications. Serum CXCL16 could be used as a biomarker together with CRP in these patients.     

Ratio of Pro-Resolving and Pro-Inflammatory Lipid Mediator Precursors as Potential Markers for Aggressive Periodontitis

Aggressive periodontitis (AgP) is a rapidly progressing type of periodontal disease in otherwise healthy individuals which causes destruction of the supporting tissues of the teeth. The disease is initiated by pathogenic bacteria in the dental biofilm, and the severity of inflammation and attachment loss varies with the host response. Recently, there has been an increased interest in determining the role of lipid mediators in inflammatory events and the concept of pro-inflammatory and pro-resolution lipid mediators has been brought into focus also in periodontal disease. The present study aimed to determine the profile of omega-3 or n3- as well as omega-6 or n6- polyunsaturated fatty acids (PUFAs) and PUFA-metabolites of linoleic acid, arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in gingival crevicular fluid (GCF), saliva and serum in AgP patients and healthy controls. In total, 60 selected n3- and n6-PUFAs and various PUFA metabolites were measured using high performance liquid chromatography-tandem electrospray ionisation mass spectrometry (HPLC-ESI-MS-MS). Of these, 51 could be quantified in this study. The concentrations of the majority were low in saliva samples compared with serum and GCF, but were mainly higher in AgP patients compared with healthy controls in all three kinds of sample. Ratios of n3- to n6-PUFAs (DHA + EPA)/AA were significantly lower in the GCF of AgP patients than in the healthy controls. Furthermore, various ratios of the direct precursors of the pro-resolution lipid mediators (precursors of resolvins and protectins) were calculated against the precursors of mainly pro-inflammatory lipid mediators. These ratios were mainly lower in GCF and saliva of AgP patients, compared with healthy controls, but only reached significance in GCF (P<0.05). To conclude, the ratios of precursors of pro-resolution/pro-inflammatory lipid mediators seem to be more relevant for describing the disease status of AgP than the concentration of specific lipid mediators.     

Removal of lead(II) by Saccharomyces cerevisiae AUMC 3875

The removal of lead(II) from artificial aqueous solution using live and dead biomass of Saccharomyces cerevisiae AUMC 3875 was investigated. The minimum inhibitory concentration (MIC) value of S. cerevisiae AUMC 3875 for lead(II) was 600 mg/l. For live and dead biomass, maximum lead(II) uptake capacities were achieved at pH?5.0, initial metal ion concentration 300 mg/l, and biomass dosage 3 g/l. Maximum biosorption capacities were reached after 3 h and 20 min for live and dead cells, respectively. Fourier Transform Infrared spectroscopy (FTIR) results revealed the important role of C?=?O,? OH,? NH, protein amide II band, $ \mathrm{PO}_2^{-} $ , mannans, sulphur and sulphur-oxygen compounds in lead(II) uptake. Scanning electron microscopy analysis (SEM) showed that the cell surface morphology and surface area/volume ratio changed greatly after lead(II) uptake. Transmission electron microscopy analysis (TEM) confirmed the involvement of both extracellular adsorption and intracellular penetration through the cell wall. X-ray powder diffraction (XRD) analysis revealed the presence of Pb(SO₄),Pb₂OSO₄ by dead biomass and Pb₃O₂(SO₄),Pb₂OSO₄ by live biomass. Energy dispersive X-ray microanalysis (EDAX) confirmed the occurrence of sulphur, oxygen and lead(II) on the cell wall. The removal of lead(II) from storage battery industry wastewater was performed by dead biomass efficiently.     

A Systematic Review of Recent Clinical Practice Guidelines on the Diagnosis,Assessment and Management of Hypertension

Background

Despite the availability of clinical practice guidelines (CPGs), optimal hypertension control is not achieved in many parts of the world; one of the challenges is the volume of guidelines on this topic and their variable quality. To systematically review the quality, methodology, and consistency of recommendations of recently-developed national CPGs on the diagnosis, assessment and the management of hypertension.

Methodology/Principal Findings

MEDLINE, EMBASE, guidelines'' websites and Google were searched for CPGs written in English on the general management of hypertension in any clinical setting published between January 2006 and September 2011. Four raters independently appraised each CPG using the AGREE-II instrument and 2 reviewers independently extracted the data. Conflicts were resolved by discussion or the involvement of an additional reviewer. Eleven CPGs were identified. The overall quality ranged from 2.5 to 6 out of 7 on the AGREE-II tool. The highest scores were for “clarity of presentation” (44.4% −88.9%) and the lowest were for “rigour of development” (8.3%–30% for 9 CGPs). None of them clearly reported being newly developed or adapted. Only one reported having a patient representative in its development team. Systematic reviews were not consistently used and only 2 up-to-date Cochrane reviews were cited. Two CPGs graded some recommendations and related that to levels (but not quality) of evidence. The CPGs'' recommendations on assessment and non-pharmacological management were fairly consistent. Guidelines varied in the selection of first-line treatment, adjustment of therapy and drug combinations. Important specific aspects of care (e.g. resistant hypertension) were ignored by 6/11 CPGs. The CPGs varied in methodological quality, suggesting that their implementation might not result in less variation of care or in better health-related outcomes.

Conclusions/Significance

More efforts are needed to promote the realistic approach of localization or local adaptation of existing high-quality CPGs to the national context.     

New Delhi metallo-��-lactamase-1: local acquisition in Ontario, Canada, and challenges in detection

New Delhi metallo-β-lactamase-1 (NDM-1) is a recently identified metallo-β-lactamase that confers resistance to carbapenems and all other β-lactam antibiotics, with the exception of aztreonam. NDM-1 is also associated with resistance to many other classes of antibiotics. The enzyme was first identified in organisms isolated from a patient in Sweden who had previously received medical treatment in India, but it is now recognized as endemic throughout India and Pakistan and has spread worldwide. The gene encoding NDM-1 has been found predominantly in Escherichia coli and Klebsiella pneumoniae. We describe the isolation NDM-1–producing organisms from two patients in Toronto, Ontario. To the best of our knowledge, this is the first report of an organism producing NDM-1 that was locally acquired in Canada. We also discuss the evidence that NDM-1 can affect bacterial species other than E. coli and K. pneumoniae, the limited options for treatment and the difficulty laboratories face in detecting organisms that produce NDM-1.New Delhi metallo-β-lactamase-1 (NDM-1) is a metallo-β-lactamase that confers resistance to carbapenems and all other β-lactam antibiotics, with the exception of aztreonam. It is predominantly found in the Enterobacteriaeceae. It was first identified in Escherichia coli and Klebsiella pneumoniae isolated from a patient in Sweden who had previously received medical treatment in India. It is now recognized as endemic throughout India and Pakistan and has spread worldwide due to travel, “medical tourism” and the ability of the genetic element encoding the enzyme to transfer between bacteria.^1–3 Three reports of organisms producing NDM-1 in Canada have been published to date. In each instance, the organisms were isolated from the urinary tracts of patients who had recently been admitted to hospitals in India. Two of the isolates were strains of K. pneumoniae and one was a strain of E. coli.^4–6 Additional reports of isolation of organisms producing NDM-1 from patients in Canada have been presented in the lay press.Organisms that produce NDM-1 have been associated with resistance to classes of antibiotics other than the β-lactams, thus severely limiting options for treatment.² Infection control guidance regarding the management of colonization by or infection with organisms that produce carbapenemases, such as NDM-1, have recently been published by Canadian and European authorities.^7–9 An essential component of these recommendations is the rapid and accurate identification of the organisms in a clinical microbiology laboratory. The Clinical Laboratory Standards Institute (CLSI) and the United States Centers for Disease Control and Prevention (CDC) recommend screening for the production of carbapenemase using the Modified Hodge Test.^10,11 If the result of that test is positive, then the presence and type of carbapenemase can be confirmed by polymerase chain reaction.⁴Herein, we summarize two additional instances in which organisms producing NDM-1 were isolated from patients in Canada and the first where the organism appears to have been acquired in Canada.     

Enhancing Functional Expression of Heterologous <Emphasis Type="Italic">Burkholderia</Emphasis> Lipase in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Functional expression of lipase from Burkholderia sp. C20 (Lip) in various cellular compartments of Escherichia coli was explored. The poor expression in the cytoplasm of E. coli was improved by several strategies, including coexpression of the cytoplasmic chaperone GroEL/ES, using a mutant E. coli host strain with an oxidative cytoplasm, and protein fusion technology. Fusing Lip with the N-terminal peptide tags of T7PK, DsbA, and DsbC was effective in enhancing the solubility and biological activity. Non-fused Lip or Lip fusions heterologously expressed in the periplasm of E. coli formed insoluble aggregates with a minimum activity. Biologically active and intact Lip was obtained upon the secretion into the extracellular medium using the native signal peptide and the expression performance was further improved by coexpression of the periplasmic chaperon Skp. The extracellular expression was even more effective when Lip was secreted as a Lip–HlyA fusion via the α-hemolysin transporter. Finally, Lip could be functionally displayed on the E. coli cell surface when fused with the carrier EstA.     

Dysfunctional HDL containing L159R ApoA-I leads to exacerbation of atherosclerosis in hyperlipidemic mice

The mutation L159R apoA-I or apoA-I_L159R (FIN) is a single amino acid substitution within the sixth helical repeat of apoA-I. It is associated with a dominant negative phenotype, displaying hypoalphaproteinemia and an increased risk for atherosclerosis in humans. Mice lacking both mouse apoA-I and LDL receptor (LDL^−/−, apoA-I^−/−) (double knockout or DKO) were crossed > 9 generations with mice transgenic for human FIN to obtain L159R apoA-I, LDLr^−/−, ApoA-I^−/− (FIN-DKO) mice. A similar cross was also performed with human wild-type (WT) apoA-I (WT-DKO). In addition, FIN-DKO and WT-DKO were crossed to obtain WT/FIN-DKO mice. To determine the effects of the apoA-I mutations on atherosclerosis, groups of each genotype were fed either chow or an atherogenic diet for 12 weeks. Interestingly, the production of dysfunctional HDL-like particles occurred in DKO and FIN-DKO mice. These particles were distinct with respect to size, and their enrichment in apoE and cholesterol esters. Two-dimensional gel electrophoresis indicated that particles found in the plasma of FIN-DKO mice migrated as large α₃-HDL. Atherosclerosis analysis showed that FIN-DKO mice developed the greatest extent of aortic cholesterol accumulation compared to all other genotypes, including DKO mice which lack any apoA-I. Taken together these data suggest that the presence of large apoE enriched HDL particles containing apoA-I L159R lack the normal cholesterol efflux promoting properties of HDL, rendering them dysfunctional and pro-atherogenic. In conclusion, large HDL-like particles containing apoE and apoA-I_L159R contribute rather than protect against atherosclerosis, possibly through defective efflux properties and their potential for aggregation at their site of interaction in the aorta. This article is part of a Special Issue entitled Advances in High Density Lipoprotein Formation and Metabolism: A Tribute to John F. Oram (1945-2010).     

Nascent high density lipoproteins formed by ABCA1 resemble lipid rafts and are structurally organized by three apoA-I monomers

This report details the lipid composition of nascent HDL (nHDL) particles formed by the action of the ATP binding cassette transporter A1 (ABCA1) on apolipoprotein A-I (apoA-I). nHDL particles of different size (average diameters of ～ 12, 10, 7.5, and <6 nm) and composition were purified by size-exclusion chromatography. Electron microscopy suggested that the nHDL were mostly spheroidal. The proportions of the principal nHDL lipids, free cholesterol, glycerophosphocholine, and sphingomyelin were similar to that of lipid rafts, suggesting that the lipid originated from a raft-like region of the cell. Smaller amounts of glucosylceramides, cholesteryl esters, and other glycerophospholipid classes were also present. The largest particles, ～ 12 nm and 10 nm diameter, contained ～ 43% free cholesterol, 2-3% cholesteryl ester, and three apoA-I molecules. Using chemical cross-linking chemistry combined with mass spectrometry, we found that three molecules of apoA-I in the ～ 9-14 nm nHDL adopted a belt-like conformation. The smaller (7.5 nm diameter) spheroidal nHDL particles carried 30% free cholesterol and two molecules of apoA-I in a twisted, antiparallel, double-belt conformation. Overall, these new data offer fresh insights into the biogenesis and structural constraints involved in forming nascent HDL from ABCA1.     

Association of MicroRNA-196a2 Variant with Response to Short-Acting β2-Agonist in COPD: An Egyptian Pilot Study

Chronic obstructive pulmonary disease (COPD) is a multifactorial chronic respiratory disease, characterized by an obstructive pattern. Understanding the genetic predisposition of COPD is essential to develop personalized treatment regimens. MicroRNAs (miRNAs) are small, endogenous, non-coding RNAs that modulate the expression levels of specific proteins based on sequence complementarity with their target mRNA molecules. Emerging evidences demonstrated the potential use of miRNAs as a disease biomarker. This pilot study aimed to investigate the association of the MIR-196a2 rs11614913 (C/T) polymorphism with COPD susceptibility, the clinical outcome and bronchodilator response to short-acting β₂-agonist. Genotyping of rs11614913 polymorphism was determined in 108 COPD male patients and 116 unrelated controls using real-time polymerase chain reaction technology. In silico target prediction and network core analysis were performed. COPD patients did not show significant differences in the genotype distribution (p = 0.415) and allele frequencies (p = 0.306) of the studied miRNA when compared with controls. There were also no associations with GOLD stage, dyspnea grade, disease exacerbations, COPD assessment test for estimating impact on health status score, or the frequency of intensive care unit admission. However, COPD patients with CC genotype corresponded to the smallest bronchodilator response after Salbutamol inhalation, the heterozygotes (CT) had an intermediate response, while those with the TT genotype showed the highest response (p < 0.001). In conclusion MIR-196a2 rs11614913 polymorphism is associated with the bronchodilator response of COPD in our sample of the Egyptian population, generating hypothesis of the potential use of MIR-196a2 variant as a pharmacogenetic marker for COPD.     

Pro-Aging Effects of Glucose Signaling through a G Protein-Coupled Glucose Receptor in Fission Yeast

Glucose is the preferred carbon and energy source in prokaryotes, unicellular eukaryotes, and metazoans. However, excess of glucose has been associated with several diseases, including diabetes and the less understood process of aging. On the contrary, limiting glucose (i.e., calorie restriction) slows aging and age-related diseases in most species. Understanding the mechanism by which glucose limits life span is therefore important for any attempt to control aging and age-related diseases. Here, we use the yeast Schizosaccharomyces pombe as a model to study the regulation of chronological life span by glucose. Growth of S. pombe at a reduced concentration of glucose increased life span and oxidative stress resistance as reported before for many other organisms. Surprisingly, loss of the Git3 glucose receptor, a G protein-coupled receptor, also increased life span in conditions where glucose consumption was not affected. These results suggest a role for glucose-signaling pathways in life span regulation. In agreement, constitutive activation of the Gα subunit acting downstream of Git3 accelerated aging in S. pombe and inhibited the effects of calorie restriction. A similar pro-aging effect of glucose was documented in mutants of hexokinase, which cannot metabolize glucose and, therefore, are exposed to constitutive glucose signaling. The pro-aging effect of glucose signaling on life span correlated with an increase in reactive oxygen species and a decrease in oxidative stress resistance and respiration rate. Likewise, the anti-aging effect of both calorie restriction and the Δgit3 mutation was accompanied by increased respiration and lower reactive oxygen species production. Altogether, our data suggest an important role for glucose signaling through the Git3/PKA pathway to regulate S. pombe life span.