Isolation and purification of an enzyme hydrolyzing ochratoxin A from aspergillus niger

Ochratoxin A is a mycotoxin produced by several Aspergillus and some Penicillium species which may be present in food and feed products. It can be enzymatically hydrolyzed into ochratoxin α and l-β-phenylalanine, thereby decreasing its toxicity. The ochratoxin A degradation capacity of Aspergillus niger is well known and here we report the isolation and purification of a novel enzyme from A. niger that hydrolyzes this mycotoxin. A wheat germ medium supplemented with ochratoxin A was used to produce the enzyme, which was purified from culture filtrate by acetone precipitation and anion exchange chromatography. An overall purification of 2.5-fold with a recovery of 68% and a final specific activity of 36 U/mg was obtained. The enzyme is a metalloenzyme as it was inhibited at 10 mM EDTA, whereas PMSF had no effect. The ochratoxin A hydrolytic enzyme presented a V max of 0.44 μM/min and a K m of 0.5 mM when the reaction was carried out at pH 7.5 and 37°C.Fundação para a Ciência e a Tecnologia (FCT

Mineral composition in cognate inclusions in Late Miocene-Early Pliocene potassic lamprophyres with affinities to lamproites from the Denizli region, Western Anatolia, Turkey: Implications for uppermost mantle processes in a back-arc setting

Mineral assemblages of both cognate inclusions and host-lamprophyres with lamproitic affinity in Kocapinar district (Denizli), Western Anatolia, consist of phlogopitic mica, diopsidic clinopyroxene, K-feldspar, apatite, opaque and carbonates (calcite-dolomite). Two distinct types of cognate inclusions have been defined in host lamprophyres: clinopyroxene-rich (CCI) and clinopyroxene-phlogopite-rich (CPCI). Whole-rock compositions of inclusions show a near-primitive nature with high MgO (7.56-15.1wt.%), Cr (195-2270ppm), Ni (213-335ppm) contents and a potassic character [K 2O (2.0-2.8wt.%)>Na 2O (0.4-2.2wt.%)]. Data imply that the inclusions crystallized from magmas formed by melting of phlogopite-bearing pyroxenites in a peridotitic mantle source, however, the presence of reverse-zoning in clinopyroxenes with salitic Fe-rich green cores in host-lamprophyres and CPCI inclusions suggest that the Denizli lavas represent mixtures of distinct (probably ultrapotassic and alkali basaltic) magmas. Estimated geobarometric constraints inferred from clinopyroxene compositions in CCI and CPCI inclusions indicate moderate pressures of pyroxene crystallization (ranging between 1.7 and 2.2GPa and corresponding to 53-70km depths) under low pressure magma fractionation. Results reveal that i) the origin of Denizli lamprophyres with transitional (between arc-type and intra-plate-type) geochemical signatures is consistent with a shallow level mantle petrogenesis, rather than a deep-seated origin related to mantle convection, ii) the source was a highly refractory and metasomatized peridotitic mantle present at the base of the lower crust, iii) metasomatic agents that affected the mantle lithosphere beneath Denizli region are distinct from those beneath other western Anatolia orogenic centers, and iv) the transitional character of Kocapinar (Denizli) lamprophyric rocks were probably formed as a result of either underplating or contamination of asthenospheric magma at the base of the mantle lithosphere, or assimilation of delaminated continental edge-lithospheric mantle via ascending asthenosphere. Denizli lamprophyres are interpreted to have formed during the formation of a basin/graben structure in the Latest Miocene-Early Pliocene, just after Late Miocene exhumation of Menderes massif. © 2012 Elsevier B.V

Stigma of tuberculosis scale: Validity and reliability [Tüberküloz Damgalanma Ölçeği: Geçerliliği ve güvenilirlik]

PubMed ID: 26523901Introduction: In many health conditions, stigma is receiving increasing attention. Public stigmatization toward social illness can affect particularly the patients and family memberships to help seeking behavior and treatment. This study, the aim of this study was to investigate the validity and reliability of the Turkish “Stigma of Tuberculosis Scale ” which was developed to evaluate of perception of stigma with tuberkulosis patient. Patients and Methods: This methodological study was conducted with 150 with tuberculosis disease people who above 18 age and without known psychological and mental disability. In the study, “Stigma of Tuberculosis Scale” was used as data collection tool. During the study, language equivalence, content validity, reliability and construct validity of the scale was performed. The data was assessed by using mean, median, standard deviation, Spearman Correlation, Cronbach Alpha coefficient and confirmatory factor analysis. Results: The mean age of study participants was 45.6 ± 16.1 (20-85). years. Spearman correlation coefficient of the scale for testretest reliability was 0.853 and the Cronbach Alpha coefficient was 0.95. According to fit indexes of confirmatory factor analysis [x2/ SD= 481.38/230= 2.09; RMSEA= 0.087; GFI= 0.776; CFI= 0.776; NNFI= 0.875] it was found that one factors were appropriate for the scale. Conclusion: The adoption of the translated “Stigma of Tuberculosis Scale”in Turkey is found reliable and valid to evaluate of perception of stigma with tuberkulosis patient. © 2015, Ankara University. All rights reserved