Publications by authors named "Oliver Broedel"

Nile tilapia (Oreochromis niloticus) is a species of worldwide importance for aquaculture. A crossbred lineage was developed through introgressive backcross breeding techniques and combines the high growth performance of the Chitralada (CHIT) lwith attractive reddish color of the Red Stirling (REDS) strains. Since the crossbreed has an unknown genetically improved background, the objective of this work was to characterize expression signatures that portray the advantageous phenotype of the crossbreeds.

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Zebrafish embryos are being increasingly used as model organisms for the assessment of single substances and complex environmental samples for regulatory purposes. Thus, it is essential to fully understand the xenobiotic metabolism during the different life-stages of early development. The aim of the present study was to determine arylhydrocarbon receptor (AhR)-mediated activity during selected times of early development using qPCR, enzymatic activity through measurement of 7-ethoxyresorufin-O-deethylase (EROD) activity, and protein expression analysis.

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We report that reliable quantitative proteome analyses can be performed with tissue samples stored at -80 degrees C for up to 10 years. However, storing protein extracts at 4 degrees C for 24 h and freezing protein extracts at -80 degrees C and thawing them significantly altered 41.6 and 17.

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The reliability of 2-DE gel-based comparative proteomics is severely impaired by the potential presence of overlapping proteins. We describe a methodological procedure which may solve this problem. Corresponding protein spots from two experimental groups are digested in the presence of 16O and 18O, respectively.

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We performed quantitative comparisons with the two-dimensional gel electrophoresis technique and evaluated the reliability of biostatistical tests for the correction of "false significant" results (alpha-error) by performing repeated runs of an experiment. Results based on uncorrected p-values yielded numerous significant differences in spot intensity which could not be replicated in two additional runs. The best strategy for avoiding these "false-positive" results was strongly dependent on the type of result.

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We investigated the effects of tissue samples taken from rat brain on the reliability of three protein quantification kits: the Bradford assay, the 2-D Quant Kit, and the EZQ Protein Quantitation Kit. All three assays measured significantly smaller amounts of protein after extraction than the reference values before extraction. Only small effects were seen in homogenates, but very pronounced differences in membrane-enriched and highly lipophilic subcellular fractions.

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When the p-value is set at <0.05 in statistical group comparisons, a 5% rate of "false significant" results is expected. In order to test the reliability of our 2-DE method, we loaded each of 24 gels with equal-sized samples (200 mug protein from pooled rat brain, pH 4-7, stained with ruthenium fluorescent stain for visualization) and statistically compared the first 12 gels with the last 12.

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Little is known about what happens to transmembrane proteins (TMP) in 2-DE. In order to obtain more insight into the whereabouts of these proteins we prepared membrane-enriched synaptosomes from rat frontal cortex and washed them with 7 M urea or Na(2)CO(3). From each preparation, 200 microg protein was loaded on 2-DE gels covering the 4-7 and 6-11 pH ranges, respectively.

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The purpose of this study was to test the extent to which differences in spot intensity can be reliably recognized between two groups of two-dimensional electrophoresis gels (pH 4-7, visualized with ruthenium fluorescent stain) each loaded with different amounts of protein from rat brain (power analysis). Initial experiments yielded only unsatisfactory results: 546 spots were matched from two groups of 6 gels each loaded with 200 microg and 250 microg protein, respectively. Only 72 spots were higher (p<0.

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Background: There have been repeated reports of antidepressant effects of thyroid hormones. In this study, we investigated whether antidepressant treatments enhance the concentrations of thyroid hormones in rat brain.

Methods: Each of the groups of rats was treated for 14 days with one of the following: an antidepressant drug (desipramine, paroxetine, venlafaxine, or tianeptine); a mood stabilizer (lithium or carbamazepine); or 8 hours' partial sleep deprivation.

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The purpose of this study was to investigate the effects of hyper- and hypothyroidism on thyroid hormone concentrations and deiodinase activities in nine regions of the rat brain. Four weeks of treatment with 75 microg thyroxine (T4)/kg body wt induced a two- to threefold increase in T4 levels in all of these brain regions, whereas the 3,5,3'-triiodothyronine (T3) concentrations were reduced in five brain regions and remained unchanged in four. Even after 8 wk treatment with 300 microg T4/kg, the T3 concentrations remained normal in cortical areas, the hippocampus and amygdala, and were elevated only in areas in which inner-ring deiodinase activity was low or absent, and in the hypothalamus.

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