Metabolic engineering and thermodynamic characterization of an extracellular β-glucosidase produced by Aspergillus niger

The production of an extracellular β-glucosidase by Aspergillus niger NRRL 599 was optimized using submerged fermentation technique. Effect of different media, different carbon sources, initial pH of the fermentation medium, temperature, incubation period and inoculum size on the production of β- glucosidase enzyme was investigated. A. niger NRRL 599 produced maximum extracellular β- glucosidase (4.48 U/mg) in Eggins and Pugh medium with 1% wheat bran (w/v) at pH 5.5 inoculated with 4% conidial suspension after 96 h of incubation at 30°C. Purified β-glucosidase gave Km and Vmax values of 3.11 mM and 20.83 U/mg respectively for pNPG hydrolysis. The enzyme was optimally active at pH 4.8 and at temperature of 60°C. Thermodynamic parameters, Ea, ΔH and ΔS were found to be 52.17 KJ/mol, 49.90 J/mol.K and -71.69 KJ/mol, respectively. The pKa1 and pKa2 of ionizable groups of active site residues involved in Vmax were calculated to be 4.1 and 6.0 respectively.Key words: β-Glucosidase, Aspergillus niger, kinetics, thermodynamics

Structural Properties and Relative Stability of (Meta)Stable Ordered, Partially-ordered and Disordered Al-Li Alloy Phases

We resolve issues that have plagued reliable prediction of relative phase stability for solid-solutions and compounds. Due to its commercially important phase diagram, we showcase Al-Li system because historically density-functional theory (DFT) results show large scatter and limited success in predicting the structural properties and stability of solid-solutions relative to ordered compounds. Using recent advances in an optimal basis-set representation of the topology of electronic charge density (and, hence, atomic size), we present DFT results that agree reasonably well with all known experimental data for the structural properties and formation energies of ordered, off-stoichiometric partially-ordered and disordered alloys, opening the way for reliable study in complex alloys.Comment: 7 pages, 2 figures, 2 Table

Anti-inflammatory and hepatoprotective potentials of the aerial parts of Silene villosa Caryophyllaceae methanol extract in rats

Purpose: To explore the anti-inflammatory and hepatoprotective potentials of Silene villosa Caryophyllaceae methanol extract in rats.Methods: Toxicity of S. villosa extract was evaluated in rats. Inflammation was induced in rats by injection of 0.1 mL carrageenan (1 %) in the left hind paws. Carbon tetrachloride (CCl4) was used to induce liver damage. Five groups of rat were used. The 1st (normal control) and 2nd (hepatotoxic) groups received the vehicle. The 3rd, 4th, and 5th groups received silymarin, 250 and 500 mg/kg of S. villosa extract, respectively, for 7 days. Liver injury was induced on the 7th day by intraperitoneal administration of 1 mL/kg of CCl4 to rats in groups 2 - 5.Results: The results showed that S. villosa is safe. It significantly reduced carrageenan-induced edema compared to normal (p < 0.01) and standard (p < 0.01) groups. The extract protected (p < 0.01) rats against the deleterious effect of CCl4. It decreased (p < 0.01) the elevated serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transferase (γ-GT) and alkaline phosphatase (ALP) as well as elevated serum levels of bilirubin (BRN), compared to CCl4 control rats. Reduced activities of the antioxidant enzymes were significantly increased (p < 0.01) in rat liver, compared with CCl4 control group. The results were confirmed by histological findings in rat liver as the extract reduced necrosis and hydropic degeneration of hepatic tissue compared to CCl4 control group.Conclusion: The results suggest that S. villosa possesses anti-inflammatory and hepatoprotective activities in rats, and therefore, has therapeutic potentials in humans.Keywords: S. villosa, anti-inflammatory, carrageenan, CCl4, antioxidant, hepatotoxicity

Multi-component quantitation of loratadine, pseudoephedrine and paracetamol in plasma and pharmaceutical formulations with liquid chromatography-tandem mass spectrometry utilizing a monolithic column

The purpose of this study was to develop a rapid, simple and sensitive quantitation method for pseudoephedrine (PSE), paracetamol (PAR) and loratadine (LOR) in plasma and pharmaceuticals using liquid chromatography-tandem mass spectrometry with a monolithic column. Separation was achieved using a gradient composition of methanol-0.1% formic acid at a flow rate of 1.0 mL min-1. Mass spectral transitions were recorded in SRM mode. System validation was evaluated for precision, specificity and linearity. Limit of detection for pseudoephedrine, paracetamol, and loratadine were determined to be 3.14, 1.86 and 1.44 ng mL-1, respectively, allowing easy determination in plasma with % recovery of 93.12 to 101.56%

Vibrational properties of phonons in random binary alloys: An augmented space recursive technique in the k-representation

We present here an augmented space recursive technique in the k-representation which include diagonal, off-diagonal and the environmental disorder explicitly : an analytic, translationally invariant, multiple scattering theory for phonons in random binary alloys.We propose the augmented space recursion (ASR) as a computationally fast and accurate technique which will incorporate configuration fluctuations over a large local environment. We apply the formalism to $Ni_{55}Pd_{45}$, Ni_{88}Cr_12} and $Ni_{50}Pt_{50}$ alloys which is not a random choice. Numerical results on spectral functions, coherent structure factors, dispersion curves and disordered induced FWHM's are presented. Finally the results are compared with the recent itinerant coherent potential approximation (ICPA) and also with experiments.Comment: 20 pages, LaTeX, 23 figure

Correlative analyses of RET and RAS mutations in a phase 3 trial of cabozantinib in patients with progressive, metastatic medullary thyroid cancer

BACKGROUND: Cabozantinib significantly prolonged progression-free survival (PFS) versus a placebo in patients with progressive, metastatic medullary thyroid cancer (MTC; P <.001). An exploratory analysis of phase 3 trial data evaluated the influence of rearranged during transfection (RET) and RAS (HRAS, KRAS, and NRAS) mutations on cabozantinib clinical activity. METHODS: Patients (n = 330) were randomized to cabozantinib (140 mg/day) or a placebo. The primary endpoint was PFS. Additional outcome measures included PFS, objective response rates (ORRs), and adverse events in RET and RAS mutation subgroups. RESULTS: Among all study patients, 51.2% were RET mutation–positive (38.2% with RET M918T), 34.8% were RET mutation–unknown, and 13.9% were RET mutation–negative. Sixteen patients were RAS mutation–positive. Cabozantinib appeared to prolong PFS versus the placebo in the RET mutation–positive subgroup (hazard ratio [HR], 0.23; 95% confidence interval [CI], 0.14-0.38; P <.0001), the RET mutation–unknown subgroup (HR, 0.30; 95% CI, 0.16-0.57; P =.0001), and the RAS mutation–positive subgroup (HR, 0.15; 95% CI, 0.02-1.10; P =.0317). The RET M918T subgroup achieved the greatest observed PFS benefit from cabozantinib versus the placebo (HR, 0.15; 95% CI, 0.08-0.28; P <.0001). The ORRs for RET mutation–positive, RET mutation–negative, and RAS mutation–positive patients were 32%, 22%, and 31%, respectively. No PFS benefit was observed in patients lacking both RET and RAS mutations, although the ORR was 21%. The safety profile for all subgroups was similar to that for the overall cabozantinib arm. CONCLUSIONS: These data suggest that cabozantinib provides the greatest clinical benefit to patients with MTC who have RET M918T or RAS mutations. However, a prospective trial is needed to confirm the relation between genetic variation and the response to cabozantinib. Cancer 2016;122:3856–3864. © 2016 American Cancer Society

Novel CNGA3 and CNGB3 mutations in two Pakistani families with achromatopsia

PURPOSE: To identify the genetic defect in two Pakistani families with autosomal recessive achromatopsia. METHODS: Two families (RP26 and RP44) were originally diagnosed with retinal dystrophy based upon their medical history. To localize the causative genes in these families, homozygosity mapping was performed using Affymetrix 10K single nucleotide polymorphism (SNP) arrays. Sequence analysis was used to find the mutations in candidate genes cyclic nucleotide-gated channel alpha-3 (CNGA3; family RP26) and cyclic nucleotide-gated channel beta-3 (CNGB3; family RP44). Control individuals were analyzed by allele-specific PCR for the CNGA3 mutation and BstXI restriction analysis for the CNGB3 mutation. After genetic analysis, clinical diagnosis was re-evaluated by electroretinography and color vision testing. During the course of this study, selected affected members of family RP26 were given pink glasses as supportive therapy. RESULTS: Sequence analysis of the positional candidate genes identified a novel missense mutation in CNGA3 (c.822G>T; p.R274S) in family RP26, and a novel CNGB3 frameshift mutation (c.1825delG; p.V609WfsX9) in family RP44. Clinical re-evaluation after genetic analysis revealed that both families have segregating autosomal recessive achromatopsia. CONCLUSIONS: Genetic analysis of two Pakistani families with retinal disease enabled the establishment of the correct diagnosis of achromatopsia. Two novel mutations were identified in CNGA3 and CNGB3 that are both specifically expressed in cone photoreceptors. Re-evaluation of the clinical status revealed that both families had achromatopsia. The use of pink glasses in patients was helpful in reducing photophobia and enabled rod-mediated vision