Low aerobic mitochondrial energy metabolism in poorly- or undifferentiated neuroblastoma

<p>Abstract</p> <p>Background</p> <p>Succinate dehydrogenase (SDH) has been associated with carcinogenesis in pheochromocytoma and paraganglioma. In the present study we investigated components of the oxidative phosphorylation system in human neuroblastoma tissue samples.</p> <p>Methods</p> <p>Spectrophotometric measurements, immunohistochemical analysis and Western blot analysis were used to characterize the aerobic mitochondrial energy metabolism in neuroblastomas (NB).</p> <p>Results</p> <p>Compared to mitochondrial citrate synthase, SDH activity was severely reduced in NB (n = 14) versus kidney tissue. However no pathogenic mutations could be identified in any of the four subunits of SDH. Furthermore, no genetic alterations could be identified in the two novel SDH assembly factors SDHAF1 and SDH5. Alterations in genes encoding nfs-1, frataxin and isd-11 that could lead to a diminished SDH activity have not been detected in NB.</p> <p>Conclusion</p> <p>Because downregulation of other complexes of the oxidative phosphorylation system was also observed, a more generalized reduction of mitochondrial respiration seems to be present in neuroblastoma in contrast to the single enzyme defect found in hereditary pheochromocytomas.</p

Mutagenesis and Functional Studies with Succinate Dehydrogenase Inhibitors in the Wheat Pathogen Mycosphaerella graminicola

A range of novel carboxamide fungicides, inhibitors of the succinate dehydrogenase enzyme (SDH, EC 1.3.5.1) is currently being introduced to the crop protection market. The aim of this study was to explore the impact of structurally distinct carboxamides on target site resistance development and to assess possible impact on fitness

Human eeg responses to exact and statistical fractal patterns.

Attention Restoration Theory point to nature as a particularly good candidate for restoring the ability to focus and inhibit distractions. However, little effort has been directed to elaborating on what makes nature\u27s visual pattern unique for restoration purposes. One suggested explanation is the fractal properties of natural patterns (Hagerhall, 2005). Both perception studies (Hagerhall et al., 2004) and studies using quantitative electroencephalography, qEEG (Hagerhall et al., 2008) have pointed to that visual patterns with mid fractal dimension, D, seem to be the most relaxing and preferred. However, it has so far not been investigated if these responses are being driven by fractal geometry in general or by the specific form of fractal geometry found in nature. In natural scenery it is so called statistical fractals that are common because of nature\u27s integration of randomness with the underlying fractal scaling properties. A natural fractal hence looks different from an artificial exact fractal (where the patterns repeating are identical at all scales), even if the two patterns have the same D value. We have here conducted the first study in which we consider both types of fractals and morph one type into the other.qEEG was recorded from 35 subjects viewing 9 images, combining 3 fractal dimensions and 3 levels of randomness. Each image was shown for 60 seconds, interspaced by 30 seconds of a neutral grey image. The data was mainly treated by analysis of variance (repeated measures design), including both within-group (fractal dimension, level of randomness) and between-group (order) variances. Bonferroni correction was carried out and the significance level set to