Modulation of quorum sensing-controlled virulence factors in Chromobacterium violaceum by selective amino acids.

Bacterial pathogenesis regulation requires N-acyl homoserine lactone (AHL)-based quorum sensing (QS). The main objective of this study was to assess the anti-QS and anti-biofilm potential of five different amino acids, namely serine, aspartic acid, lysine, leucine and tryptophan. The selected amino acids were assessed for their ability to inhibit QS activity via such mechanisms as exopolysaccharide (EPS) production, biofilm formation, pigment production in Chromobacterium violaceum and swarming motility. At 0.684 mM concentration, lysine inhibited the biofilm formation by 16% at 24 h, chitinolytic activity by 88.3% at 24 h and EPS production by 12.5% at 24 h. It also exhibited inhibition of swarming motility in C. violaceum. Confocal laser scanning microscopy revealed a decrease in the average thickness of the biofilms when treated with lysine. Modulation in the expression of cvi I and cvi A was observed when treated with all the amino acids, with the greatest reduction observed with lysine. Our results conclude that the amino acid lysine showed anti-QS and significant anti-biofilm activities; it could be further exploited as a main constituent in the synthesis of peptide/protein, and testing the same for treatment of bacterial infections, eventually reducing the utilization of conventional antibiotics.

YKL-40: A biomarker for early nephropathy in type 2 diabetic patients and its association with inflammatory cytokines.

Diabetic Nephropathy (DN) is an important cause of morbidity and death amongst diabetes. Persistent micro and macroalbuminuria are well known predictors of DN leading to progressive end-stage renal disease. However, albuminuria has several limitations. Increasing evidences show that YKL-40 is highly expressed in variety of inflammatory diseases and also recognized as a non-invasive prognostic biomarker for inflammation. In the present study, we measured plasma YKL-40 levels in different stages of albuminuria and assessed its diagnostic accuracy as a biomarker for DN and correlated with different families of circulatory cytokines. A total of 306 subjects were recruited and divided into three groups [Group-I, control (n = 83), Group-II, Normoalbuminuria (n = 81), Group-III, DN (n = 142)]. Group-III is further subdivided into: Group-IIIa, microalbuminuria (n = 73), Group-IIIb, macroalbuminuria (n = 69). The median levels of YKL-40 (p = 0.001) showed a marked stepwise increase from normo to macroalbuminuria and positively correlated with eGFR. The AUCROC for YKL-40 was found to be high [0.95; (95% CI: 0.88-1.0)], when compared to other acute phase markers. Plasma YKL-40 showed a positive correlation with LIGHT/TNFSF14, sIL-6Ra, gp130/sIL-6Rß, IFN-ß, IL-8, TNFSF14, sCD-30 and eGFR meanwhile a negative correlation with TWEAK/TNFSF12, IL-7 like cytokine and IFN-λ2. Plasma YKL-40 could be a potential biomarker for early diagnosis of incipient DN among South Indian population.

Increased levels of circulating (TNF-α) is associated with (-308G/A) promoter polymorphism of TNF-α gene in Diabetic Nephropathy.

The crucial role of Tumor Necrosis Factor-α (TNF-α) on renal function in patients with Diabetic Nephropathy (DN) has been well documented. The present study was designed to investigate the association of TNF-α [-308G/A, (rs1800629)] single nucleotide polymorphism (SNP) on the susceptibility to DN subjects and to correlate it with the plasma levels of TNF-α along with circulatory TNF-α receptor super family cytokines (sTNFR-1 and sTNFR-2). A total of 756 subjects, were recruited and divided into groups [Group-I, Control (n=218), Group-II, Normoalbuminuria (n=196), Group-IIIa, Microalbuminuria (n=178), Group-IIIb, Macroalbuminuria (n=164)] and were genotyped by PCR-restriction fragment length polymorphism (RFLP). Circulatory levels of TNF-α and sTNFR-1 & sTNFR-2 were measured using multiplex bead based assay. The 'A' allele of TNF-α (-308 G/A) SNP was associated with a significant risk for macroalbuminuria subjects (OR: 2.1; 95% CI: 0.8-3.7; P<0.001). A marked stepwise increase was observed in the levels of circulatory biomarkers such as TNF-α, sTNF-R1 and sTNF-R2 from normo to macroalbuminuria subjects. In DN subjects, the TNF-α level was higher in individuals who had mutant AA, than the wild GG genotype of TNF-α gene. Our results conclude that rs1800629 polymorphism in TNF-α gene is associated with renal complications in T2DM subjects.

Potential of circulatory procalcitonin as a biomarker reflecting inflammation among South Indian diabetic foot ulcers.

OBJECTIVE: Diabetic foot ulcer (DFU), the major complication associated with diabetes mellitus, has been shown to precede amputation in up to 90% of cases. Recent data reveal that procalcitonin (PCT) is a valid marker for the diagnosis of bacterial infections compared with traditional markers like white blood cell count, C-reactive protein levels, and erythrocyte sedimentation rate in DFU patients. Furthermore, cytokines are proposed to act as modulators and mediators for the expression and release of PCT into the circulation. Hence, this preliminary study was conducted to evaluate the diagnostic accuracy of PCT compared with other traditional markers and to predict the association of PCT plasma levels with inflammatory cytokines and clinical parameters of incident diabetes among South Indian DFU subjects. METHODS: There were 185 subjects with type 2 diabetes mellitus (T2DM) selected in this cross-sectional study, subdivided into three groups: group I, control/T2DM subjects free from DFU (n = 75; male, 43; female, 32); group II, T2DM subjects with noninfected DFU (n = 34; male, 19; female, 15); and group III, T2DM subjects with infected DFU (IDFU; n = 76; male, 46; female, 30). Patients with IDFU were further divided into three subgroups as per the Infectious Diseases Society of America-International Working Group on the Diabetic Foot classification criteria: grade 2 (n = 27), grade 3 (n = 38), and grade 4 (n = 11). Subjects with type 1 diabetes, gestational diabetes, pneumonia, sepsis, inflammatory bowel disease, meningitis, or hematologic diseases and those who underwent surgery in the past 2 to 3 weeks were excluded from this study. For investigation of clinical parameters, blood samples were drawn from all the study subjects; plasma samples were used for estimating PCT by the enzyme-linked immunosorbent assay method. The profiling of plasma cytokines was carried out using a multiplex bead-based assay. Data are presented as mean ± standard deviation for clinical and biochemical variables and as geometric mean with 95% confidence interval (CI) for cytokines. All analysis was done using the Statistical Package for the Social Sciences (version 20.0; IBM Corp, Armonk, NY); P < .05 was considered to be statistically significant. RESULTS: We found PCT to be a valid diagnostic marker for IDFU with higher sensitivity and specificity than other traditional markers. For PCT, the area under the receiver operating characteristic curve was found to be high (0.99; 95% CI, 0.96-1.0), followed by C-reactive protein levels (0.78; 95% CI, 0.65-0.81), white blood cell count (0.76; 95% CI, 0.67-0.86), and erythrocyte sedimentation rate (0.74; 95% CI, 0.68-0.80) in IDFU subjects. We found the cutoff value of ≥0.5 ng/mL to have 54% sensitivity and 100% specificity for PCT with a positive predictive value of 100% and a negative predictive value of 12% for IDFU diagnosis. Moreover, PCT circulatory levels showed a positive correlation with helper T-cell subtype 1 cytokines, such as interferon γ (r = 0.21; P = .03) and interleukin 28A (r = 0.31; P = .003), and subtype 17 cytokines, such as interleukin 29/interferon λ1 (r = 0.20; P = .037). CONCLUSIONS: PCT could be a valuable marker for diagnosis of T2DM patients with IDFU.

A facile approach to the isolation of proteins in Ferula asafoetida and their enzyme stabilizing, anti-microbial and anti-oxidant activity.

The objective of the present study was to identify the proteome pattern, isolate and study the functions of selective proteins from Ferula asafoetida root exudate using chromatographic techniques. The root exudate proteins were fractionated using ion-exchange and gel filtration chromatography. A range of bioactive protein fractions were then separated in sufficient quantity which is the focus of this study. Based on studies, here we report three main proteins with molecular weights 14kDa, 27kDa, and 39kDa. The biological and pharmacological activities of both purified and unpurified proteins obtained were extensively studied to understand their significance. The study revelaed that 27kDa protein interestingly stabilized trypsin activity in 24h of time and retained about 64% of the enzyme activity. Analyses confirmed 40°C and pH 8.0 are the optimum temperature and pH respectively. The 39kDa protein remarkably increased the activity of chymotrypsin and the 14kDa protein showed anti-bacterial activity against Pseudomonas aeruginosa. Invariably all of the three purified proteins showed enhanced anti-oxidant activity. In conclusion, results here obtained suggested that the primary metabolites (proteins) in asafoetida are mainly responsible for its versatile biological and pharmacological activities.

Effect of H4R antagonist N-(2-aminoethyl)-5-chloro-1H-indol-2-carboxamides and 5-chloro-2-(piperazin-1-ylmethyl)-1H-benzimidazole on histamine and 4-methylhistamine-induced mast cell response.

CONTEXT: The histamine plays a decisive role in acute and chronic inflammatory responses and is regulated through its four types of distinct receptors designated from H1 to H4. Recently histamine 4 receptor (H4R) antagonists have been reported to possess various pharmacological effects against various allergic diseases. OBJECTIVE: To investigate the inhibitory effect of N-(2-aminoethyl)-5-chloro-1H-indol-2-carboxamide (Compound A) and 5-chloro-2-(piperazin-1-ylmethyl)-1H-benzimidazole (Compound L) on H4R-mediated calcium mobilization, cytokine IL-13 production, ERK1/2, Akt and NF-κB activation in human mastocytoma cells-1 (HMC-1). MATERIALS AND METHODS: Compounds A and L were synthesized chemically and their inhibitory effect on intracellular calcium release was analyzed by Fluo-4 calcium assay, cytokine measurement through ELISA and activation of signaling molecules by western blot. RESULTS: Pre-treatment with compounds A and L significantly reduced the H4R-mediated intracellular calcium release. Histamine and 4-methylhistamine (4-MH) induced Th2 cytokine IL-13 production in HMC-1 cells, was inhibited by compound A (77.61%, 74.25% at 1 µM concentration) and compound L (79.63%, 81.70% at 1 µM concentration). Furthermore, histamine induced the phosphorylation of ERK1/2, Akt and NF-κB was suppressed by compounds A and L at varying levels, ERK1/2 (88%, 86%), Akt (88%, 89%) and NF-κB (89%, 87%) in HMC-1 cells. DISCUSSION AND CONCLUSIONS: Taken together these data demonstrate that compound A and compound L may block H4R-mediated downstream signaling events.

Simple mass spectrometric method for the estimation of boron and aluminum in water at the parts per billion level.

The coordinating nature of the hydroxy carboxylic acids, such as tartaric and citric acids, has been utilized for the in-situ formation of anions representing the trivalent elements boron and aluminum and two dianions of the hydroxy acid selected under negative electrospray ionization mass spectral conditions. The abundance of these ions could be used for the quantification of boron and aluminum in water at concentrations ranging from 4.0 ppb to 535.0 ppb. For a period of six months, the validity of this method was tested with citric acid as the coordinating agent. Thus, the developed method offers a simple means for the quantification of boron and aluminum in water by negative electrospray ionization mass spectrometry with a single quadrupole mass spectrometer.

Carbohydrate-based switch-on molecular sensor for Cu(II) in buffer: absorption and fluorescence study of the selective recognition of Cu(II) ions by galactosyl derivatives in HEPES buffer.

[graph: see text] 1-(Beta-D-galactopyranosyl-1'-deoxy-1'-iminomethyl)-2-hydroxynaphthalene (L1), possessing an ONO binding core, was found to be selective for Cu2+ ions in N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid] buffer, at concentrations < or = 580 ppb, at physiological pH by eliciting switch-on behavior, whereas the other ions, viz., Mg2+, Ca2+, Mn2+, Fe2+, Co2+, Ni2+, Zn2+, and Cd2+, caused no significant change in the fluorescence. Whereas the binding characteristics were ascertained by absorption spectroscopy, the species formed were shown by Q-TOF ES MS.