Biological control of a fungus Ustilaginoidea virens causing false smut of rice

BioControl - False smut caused by the flower-infecting fungus, Ustilaginoidea virens has become an important disease of rice seriously hampering production worldwide. An experiment on the...     

Achieving Brownfields Clean Up at a Radium-Contaminated Site

One of the U.S. Army Corps of Engineer's (USACE) primary goals in the management of removal actions is to safely implement work activities and cost effectively clean up sites contaminated with residual radioactive materials. The US ACE has successfully pursued a removal action under the Brownfields Initiative at the Cuneo Press Site in Chicago, Illinois. The residual radioactive contamination at the site exceeded background radiation levels for the Chicago area. Residual quantities of Radium-226 (Ra-226) were detected during preremoval characterization surveys performed at the site. The aggressive removal action performed at the site demanded immediate and accurate radiological screening and exposure data. Radiological screening consisted of field monitoring using portable instruments and gamma spectroscopy analysis for Ra-226. The screening data provided verification of compliance to the off-site disposal facility waste acceptance criteria and the site clean up criteria. The screening data, along with the application of guidance presented in NUREG-1575, “Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM)”, demonstrated that the removal action meet clean up criteria established by the Illinois Nuclear Regulatory Commission and the USACE.     

Electrospray Ionization-Mass Spectrometry and Tandem Mass Spectrometry Reveal Self-Association and Metal-Ion Binding of Hydrophobic Peptides: A Study of the Gramicidin Dimer

Gramicidin is a membrane pentadecapeptide that acts as a channel, allowing the passage of monovalent metal ions and assisting in bacterial cell death. The active form is a noncovalently bound dimer. One means to study the self-assembly of this peptide has been to compare the state of the peptide in various solvents ranging from hydrophilic (e.g., trifluoroethanol) to hydrophobic (e.g., n-propanol). In this article, we report the use of electrospray mass spectrometry to study the self-association of gramicidin in various organic and mixed solvents that are introduced directly into the mass spectrometer. The dimer (both homo and hetero) can survive the introduction into the gas phase, and the amount in the gas phase increases with the decreasing dielectric constant of the solvent, reflecting solution-phase behavior. Tandem mass spectrometry data reveal that the stability of dimer in the gas phase decreases with increasing metal ion size, strongly suggesting that the metal ion binds inside the dimer between the monomers.     

Emerging findings from studies of phospholipase D in model organisms (and a short update on phosphatidic acid effectors)

Phospholipase D (PLD) catalyses the hydrolysis of phosphatidylcholine to generate phosphatidic acid and choline. Historically, much PLD work has been conducted in mammalian settings although genes encoding enzymes of this family have been identified in all eukaryotic organisms. Recently, important insights on PLD function are emerging from work in yeast, but much less is known about PLD in other organisms. In this review we will summarize what is known about phospholipase D in several model organisms, including C. elegans, D. discoideum, D. rerio and D. melanogaster. In the cases where knockouts are available (C. elegans, Dictyostelium and Drosophila) the PLD gene(s) appear not to be essential for viability, but several studies are beginning to identify pathways where this activity has a role. Given that the proteins in model organisms are very similar to their mammalian counterparts, we expect that future studies in model organisms will complement and extend ongoing work in mammalian settings. At the end of this review we will also provide a short update on phosphatidic acid targets, a topic last reviewed in 2006.     

Thiamine reduces tissue lead levels in rats: mechanism of interaction

Lead (Pb) toxicity has been a serious concern in industrialized societies because of its association with functional deficits in nervous, haematopoietic and renal systems. Several studies have shown beneficial effects of thiamine on Pb toxicity. It is speculated that Pb chelation by thiamine may be a possible mechanism. However, the exact nature of these interactions remained elusive. In the present study we have characterized the interaction of Pb with thiamine using UV–Vis as well as fluorescence spectroscopic methods and studied the effect of thiamine treatment on blood and tissue Pb levels during simultaneous or post-exposure to Pb in rat model. The spectroscopic studies revealed that Pb interacts with the pyrimidine ring of thiamine, leading to its solubilization at physiological pH. Further, thiamine reduced the Pb levels in blood, kidney and bone during both simultaneous and post-exposure Pb treatment. Interestingly, thiamine appears to prevent the accumulation of Pb in bone during simultaneous treatment. Together these results suggest that pyrimidine ring of thiamine mediates its interaction with Pb, leading to the prevention of its accumulation and/or increased clearance from tissues.