Effect of acriflavine on the hexokinase isozyme pattern of a yeast, Hansenula jadinii

Dried cells of a yeast, Hansenula jadinii, that had been cultured aerobically with acriflavine, contained three hexokinase isozymes and metabolized glucose at 0.6 M to produce ATP to phosphorylate nucleotides in the presence of a high concentration of phosphate. Dried cells cultured aerobically without acriflavine contained two hexokinase isozymes and could not metabolize glucose under the same conditions. Two of the isozymes of the yeast cultured with acriflavine were similar to isozymes of the yeast cultured without acriflavine. However, the third isozyme was resistant to a high phosphate concentration and caused regeneration of ATP through glycolysis and phosphorylation of nucleotides.     

Aptamer-based electrochemical biosensor by using Au-Pt nanoparticles,carbon nanotubes and acriflavine platform

Herein, an ultrasensitive electrochemical aptasensor for quantitative detection of bisphenol A (BPA) was fabricated based on a novel signal amplification strategy. This aptasensor was developed by electrodeposition of gold-platinum nanoparticles (Au-PtNPs) on glassy carbon (GC) electrode modified with acid-oxidized carbon nanotubes (CNTs-COOH). In this protocol, acriflavine (ACF) was covalently immobilized at the surface of glassy carbon electrode modified with Au-PtNPs/CNTs-COOH nanocomposite. Attachment of BPA-aptamer at the surface of modified electrode was performed through the formation of phosphoramidate bonds between the amino group of ACF and phosphate group of the aptamer at 5′end. By interaction of BPA with the aptamer, the conformational of aptamer was changed which lead to retarding the interfacial electron transfer of ACF as a probe. Sensitive quantitative detection of BPA was carried out by monitoring the decrease of differential pulse voltammetric (DPV) responses of ACF peak current with increasing the BPA concentration. The resultant aptasensor exhibited good specificity, stability and reproducibility, indicating that the present strategy was promising for broad potential application.     

Plasmid curing from an acidophilic bacterium of the genus Acidocella

Preservation of the acidophilic heterotroph, Acidocella sp. strain GS19h, at 4 degrees C in stab culture eliminated all indigenous plasmids from this bacterium. Growth at 42 degrees C initially caused changes in the plasmid profile followed by total elimination of plasmids after 10 cycles of growth. Concomitant to this loss of all plasmids, the cured derivatives became sensitive to CdSO(4) and ZnSO(4), and the MIC value of the salts dropped from 1 M for each in the case of parental strain to 2 mM and 5 mM, respectively, suggesting plasmid-mediated inheritance of metal resistance in this bacterium. The cured derivatives could not utilise lactose, indicating this metabolic activity to be plasmid-associated in this strain.     

Ascaridia galli: effects of immunosuppressive drugs or bursectomy in chickens

Immunosuppressive drugs significantly increasing numbers of A. galli and incidences of infection were: cortisone, cortisol, 9-α-fluorohydrocortisone, 2-methyl-9-α-fluorohydrocortisone, prednisone, prednisolone, 6-mercaptopurine, 2, 6-diaminopurine, 6-thioguanine, 5-bromodeoxyridine, 5-fluorouracil, methotrexate, chlorambucil, and actinomycin D. These drugs and/or worm burdens significantly suppressed weight gains of hosts, and neither altered the male:female ratio of worms nor their growth. The following drugs neither altered worm burdens nor increased incidences of infection: corticosterone, 2-azaadenine, 8-azaguanine, azathioprine, 6-azauridine, busulfan, thio-TEPA, triethylenemelamine, vincristine, acriflavine, reserpine, and l-phenylalanine.Worm burdens and incidences of infection were increased significantly in chickens surgically bursectomized when 3 or 14 but not 35 days old. Chicks bursectomized in ovo with testerosterone propionate on Day 5 or 14 of incubation and infected on Day 14 after hatching developed significantly increased worm burdens and incidences of infection.Applying the Kolmogorov-Smirnov test for goodness of fit to data on increased worm burdens showed that the immunosuppressive drugs or bursectomy had a normalization effect on the statistical distribution.