Relations Between Tocopherol Depletion and Coenzyme Q During Lipid Peroxidation in rat Liver Mitochondria

In order to evaluate different mitochondrial antioxidant systems, the depletion of alpha-tocopherol and the levels of the reduced and oxidized forms of CoQ were measured in rat liver mitochondria during Fe⁺⁺/ascorbate and NADPH/ADP/Fe⁺⁺ induced lipid peroxidation. During the induction phase of malondialdehyde formation, alpha-tocopherol declined moderately to about 80% of initial contents, whereas the total CoQ pool remained nearly unchanged, but reduced CoQ9 continuously declined. At the start of massive malondialdehyde formation, CoQ9 reaches its fully oxidized state. At the same time alpha-tocopherol starts to decline steeply, but never becomes fully exhausted in both experimental systems. Evidently the oxidation of the CoQ9 pool constitutes a prerequisite for the onset of massive lipid peroxidation in mitochondria and for the subsequent depletion of alpha-tocopherol. Trapping of the GSH by addition of dinitrochlorbenzene (a substrate of the GSH transferase), results in a moderate acceleration of lipid peroxidation, but alpha-tocopherol and ubiquinol levels remained unchanged when compared with the controls. Addition of succinate to GSH depleted mitochondria effectively suppressed MDA formation as well as alpha-tocopherol and ubiquinol depletion. The data support the assumption that the protective effect of respiratory substrates against lipid peroxidation in the absence of mitochondrial GSH is mediated by the regeneration of the lipid soluble antioxidants CoQ and alpha-tocopherol.     

snp.plotter: an R-based SNP/haplotype association and linkage disequilibrium plotting package

snp.plotter is a newly developed R package which produces high-quality plots of results from genetic association studies. The main features of the package include options to display a linkage disequilibrium (LD) plot below the P-value plot using either the r2 or D' LD metric, to set the X-axis to equal spacing or to use the physical map of markers, and to specify plot labels, colors, symbols and LD heatmap color scheme. snp.plotter can plot single SNP and/or haplotype data and simultaneously plot multiple sets of results. R is a free software environment for statistical computing and graphics available for most platforms. The proposed package provides a simple way to convey both association and LD information in a single appealing graphic for genetic association studies. AVAILABILITY: Downloadable R package and example datasets are available at http://cbdb.nimh.nih.gov/~kristin/snp.plotter.html and http://www.r-project.org.     

Adenovirus in Rural Côte D`Ivoire: High Diversity and Cross-Species Detection

The Taï region in Western Côte d`Ivoire is characterized by extensive overlap of human and animal habitats. This could influence patterns of adenovirus transmission between humans and domestic animals. Fecal samples from humans and various domestic animals were tested for the presence of adenoviruses by PCR. Phylogenetic and species delineation analyses were performed to further characterize the adenoviruses circulating in the region and to identify potential cross-species transmission events. Among domestic animals, adenovirus shedding was frequent (21.6% of domestic mammals and 41.5% of chickens) and the detected strains were highly diverse, several of them representing novel types. Although no evidence for zoonotic transmission of animal adenovirus was obtained, the present study provides concordant evidence in favor of common cross-species transmission of adenoviruses between different animal species and first indications for adenovirus transmission from humans to animals. These findings underline the thus far underestimated importance of reverse zoonotic transmission of viruses and of the role of domestic animals as pathogen reservoirs, “bridge species,” or intermediate hosts.     

Dynamics of the linuron hydrolase libA gene pool size in response to linuron application and environmental perturbations in agricultural soil and on-farm biopurification systems

libA, a gene encoding a novel type of linuron hydrolase, was recently identified in the linuron-mineralizing Variovorax sp. strain SRS16. In order to assess the contribution of libA to linuron degradation in environmental settings, libA abundance was monitored in response to the application of linuron and to environmental perturbations in agricultural soil microcosms and microcosms simulating the matrix of on-farm biopurification systems. libA numbers were measured by real-time PCR and linked to reported data of Variovorax community composition and linuron mineralization capacity. In the soil microcosms and one biopurification system setup, libA numbers responded to the application of linuron and environmental changes in congruency with the modulation of linuron mineralization capacity and the occurrence of a particular Variovorax phylotype (phylotype A). However, in another biopurification system setup, no such correlations were found. Our data suggest that in the simulated environmental settings, the occurrence of libA can be linked to the linuron mineralization capacity and that libA is primarily hosted by Variovorax phylotype A strains. However, the results also suggest that, apart from libA, other, as-yet-unknown isofunctional genes play an important role in linuron mineralization in the environment.     

Eph receptor and ephrin ligand-mediated interactions during angiogenesis and tumor progression

Eph receptors comprise the largest family of receptor tyrosine kinases. They are classified into an A family and a B family on the basis of the characteristic properties of the corresponding ephrin ligands which are either GPI-anchored peripheral membrane molecules (A class ephrins) or transmembrane molecules (B class ephrins). Eph receptors and ephrin ligands were originally identified as neuronal pathfinding molecules. Yet, gene targeting experiments in mice have identified the EphB/ephrinB system as critical and rate-limiting determinant of arterio-venous differentiation during embryonic vascular development. Identification of vascular EphB/ephrinB functions has in the last few years stimulated two emerging fields of vascular biology research, namely (1) the molecular analysis of the structural and functional mechanisms of arterio-venous differentiation, and (2) the molecular study of the commonalities between vascular and neuronal guidance and patterning mechanisms. This review summarizes the current understanding of vascular Eph receptor and ephrin ligand functions and provides an overview of emerging roles of the Eph/ephrin system in controlling tumor and vascular functions during tumorigenesis and tumor progression.     

Biotransformation of 1-Naphthol by a Strictly Aquatic Fungus

The aquatic hyphomycete Heliscus lugdunensis belongs to a group of exclusively aquatic mitosporic fungi with an only scarcely explored potential to oxidatively attack xenobiotic compounds, and was used to study the biotransformation of the environmental pollutant metabolite 1-naphthol. H. lugdunensis metabolized approximately 74% of 1-naphthol within 5 days. The identification and quantification of degradation products using gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, and high performance liquid chromatography revealed that approximately 12% of the parent compound was converted into 1-naphthylsulfate, 3% was transformed into 1-methoxy-naphthalene, and less than 1% was converted into 1,4-naphthoquinone. A further metabolite, most likely 4-hydroxy-1-naphthylsulfate, was also detected. In contrast to sulfate conjugate metabolites, no glucuronide and glucoside conjugates of 1-naphthol were found, and neither UDP-glucuronyltransferase nor UDP-glucosyltransferase present in H. lugdunensis showed activity towards 1-naphthol. These results support a role of fungi adapted to aquatic environments in affecting the environmental fate of pollutants in aquatic ecosystems.     

Synbiotic Microcapsules That Enhance Microbial Viability during Nonrefrigerated Storage and Gastrointestinal Transit

A Bifidobacterium infantis strain was microencapsulated within a film-forming protein-carbohydrate-oil emulsion. This novel encapsulant incorporated prebiotics and substantially protected the bacterium during nonrefrigerated storage and gastrointestinal transit. The dried microcapsules were small (15 to 20 μm), had low water activity (0.2 to 0.3), and rapidly released the bacteria in simulated intestinal fluid.