Cellular distribution of vascular endothelial growth factor A (VEGFA) and B (VEGFB) and VEGF receptors 1 and 2 in focal cortical dysplasia type IIB

Members of the vascular endothelial growth factor (VEGF) family are key signaling proteins in the induction and regulation of angiogenesis, both during development and in pathological conditions. However, signaling mediated through VEGF family proteins and their receptors has recently been shown to have direct effects on neurons and glial cells. In the present study, we immunocytochemically investigated the expression and cellular distribution of VEGFA, VEGFB, and their associated receptors (VEGFR-1 and VEGFR-2) in focal cortical dysplasia (FCD) type IIB from patients with medically intractable epilepsy. Histologically normal temporal cortex and perilesional regions displayed neuronal immunoreactivity (IR) for VEGFA, VEGFB, and VEGF receptors (VEGFR-1 and VEGFR-2), mainly in pyramidal neurons. Weak IR was observed in blood vessels and there was no notable glial IR within the grey and white matter. In all FCD specimens, VEGFA, VEGFB, and both VEGF receptors were highly expressed in dysplastic neurons. IR in astroglial and balloon cells was observed for VEGFA and its receptors. VEGFR-1 displayed strong endothelial staining in FCD. Double-labeling also showed expression of VEGFA, VEGFB and VEGFR-1 in cells of the microglia/macrophage lineage. The neuronal expression of both VEGFA and VEGFB, together with their specific receptors in FCD, suggests autocrine/paracrine effects on dysplastic neurons. These autocrine/paracrine effects could play a role in the development of FCD, preventing the death of abnormal neuronal cells. In addition, the expression of VEGFA and its receptors in glial cells within the dysplastic cortex indicates that VEGF-mediated signaling could contribute to astroglial activation and associated inflammatory reactions

Above-ground growth responses of forest trees to elevated CO2

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Environmental effects over the first 2½ rotation periods of a fertilised poplar short rotation coppice

A short rotation coppice (SRC) with poplar was established in a randomised fertilisation experiment on sandy loam soil in Potsdam (Northeast Germany). The main objective of this study was to assess if negative environmental effects as nitrogen leaching and greenhouse gas emissions are enhanced by mineral nitrogen (N) fertiliser applied to poplar at rates of 0, 50 and 75 kg N ha−1 year−1 and how these effects are influenced by tree age with increasing number of rotation periods and cycles of organic matter decomposition and tree growth after each harvesting event. Between 2008 and 2012, the leaching of nitrate (NO3 −) was monitored with self-integrating accumulators over 6-month periods and the emissions of the greenhouse gases (GHG) nitrous oxide (N2O) and carbon dioxide (CO2) were determined in closed gas chambers. During the first 4 years of the poplar SRC, most nitrogen was lost through NO3 − leaching from the main root zone; however, there was no significant relationship to the rate of N fertilisation. On average, 5.8 kg N ha−1 year−1 (13.0 kg CO2equ) was leached from the root zone. Nitrogen leaching rates decreased in the course of the 4-year study parallel to an increase of the fine root biomass and the degree of mycorrhization. In contrast to N leaching, the loss of nitrogen by N2O emissions from the soil was very low with an average of 0.61 kg N ha−1 year−1 (182 kg CO2equ) and were also not affected by N fertilisation over the whole study period. Real CO2 emissions from the poplar soil were two orders of magnitude higher ranging between 15,122 and 19,091 kg CO2 ha−1 year−1 and followed the rotation period with enhanced emission rates in the years of harvest. As key-factors for NO3 − leaching and N2O emissions, the time after planting and after harvest and the rotation period have been identified by a mixed effects mode

Effects of high levels of CO2 on gene expression in tow different genotypes of <em>Fagus sylvatica.</em>

Background The scenario of a changing environment, widely termed as global change is mainly caused by human activities. Oil and carbon combustion, the use of chlorofluorocarbons, and deforestation are one of the main factors responsible for increasing CO2 concentration and for an increase of air temperature. In addition global changes will affect precipitation patterns, nitrogen concentration in the atmosphere and enhanced UV-B radiation. Forest trees constitute a relevant economic and ecological resource that is under severe pressure by such environmental changes. However, the response of forest trees and in particular of the important forest tree species Fagus sylvatica to elevated CO2 levels on a gene expression basis is unknown so far. The principal aim of this study is the investigation of two different genotypes of Fagus sylvatica upon increased CO2 by microarray and gene expression analyses. Materials and methods Shoots of F. sylvatica (Germany) and F. sylvatica &ldquo;purpurea tree&rdquo; (Germany) were grafted on F. sylvatica rootstocks. Plants were kept for 10 days under controlled conditions in climate chambers using the same temperature and light parameters, whereas the CO2 concentration was approx. 380-400 ppm (ambient) in the control chamber and 1000 ppm (high) in the CO2 chamber. Five leaves were taken from arbitrary chosen plants in control and high CO2 chamber at 2 different time points (T2=2 days and T10=10 days) with 3 biological replicatesper each genotype per each sampling time point. The leaves were immediately frozen in liquid nitrogen and stored at -80&deg;C. Extraction of total RNA was according to Kiefer et al[1] and microarray analyses were carried out as described by Olbrich et al[2]. Real Time PCR (RT-PCR) [3,4] analyses were carried out for selected genes to evaluate changes in gene expression. Results The microarray resulted in differentially expressed gene at T2 and T10 in each beech genotype analyzed. In particular, genes involved in photosynthesis and chloroplast biogenesis were up regulated at T2. A similar trend was been for genes involved in sugar metabolism. This indicates that, at high CO2 concentration, the activity of the photosynthesis machinery will be accelerated and, therefore, also the one of the glycolysis pathway which brings to an accumulation of carbon. After 10 days of high CO2 level, few of these genes were down regulated but most of them are expressed at normal level. This effect has previously been described in most of the studies on pot-grown other C3 plants under elevated CO2 which have indicated photosynthetic acclimation [5]. This response was particularly evident for the F. sylvatica&ldquo;purpurea tree&rdquo; showing a different behaviour to the second beech genotype. RT-PCR for genes involved in photosynthesis, chloroplast biogenesis and sugar metabolism are in progress for both genotypes. Conclusions A lot of studies have reported contradictory responses of higher C3 plants to elevated levels of CO2. This observation has also been made in the two German beech genotypes analyzed in this work confirming high expression variability between different genotypes of the same plant species. Therefore, considering the importance to preserve the forest ecosystems under global climate change, further investigations are necessary to understand the regulatory events associated with the adaptive acclimation responses of trees. A lot of studies have reported contradictory responses of higher C3 plants to elevated levels of CO2. This observation has also been made in the two German beech genotypes analyzed in this work confirming high expression variability between different genotypes of the same plant species. Therefore, considering the importance to preserve the forest ecosystems under global climate change, further investigations are necessary to understand the regulatory events associated with theadaptive acclimation responses of trees. &nbsp

The St George's Respiratory Questionnaire revisited : a psychometric evaluation

PURPOSE: The St George's Respiratory Questionnaire (SGRQ) has clearly acquired the status of legacy questionnaire for measuring health-related quality of life in patients with chronic obstructive pulmonary disease (COPD). The main aim of this study was to assess the underlying dimensionality of the SGRQ and to investigate the added value of the empirical weights used to calculate total scores. METHODS: The official Dutch translation of the SGRQ was completed by 444 COPD patients participating in two clinical studies. These data were used for secondary data analysis in this study. Three complementary statistical methods were used to assess dimensionality: Mokken scale analysis (MSA), parametric multidimensional item response theory (IRT) and bifactor analysis. Additionally, the original SGRQ weighting procedure was compared to IRT-based weighting. RESULTS: The results of the MSA and multidimensional item response theory (MIRT) pointed toward a unidimensional structure. The bifactor analyses indicated that there was a strong general factor, but the group factors did have additional value. Nineteen items performed poorly in the MSA, MIRT analysis or both. Shortening the scale from 50 to 31 items did not negatively impact measurement precision. SGRQ total score and IRT-derived scores correlated strongly, 0.90 for the one-parameter model and 0.99 for the two-parameter model. CONCLUSION: The SGRQ contains some multidimensionality, but an abbreviated version can be used as a unidimensional tool in patients with COPD. Subscale scores should be used with care. SGRQ total scores correlated highly with IRT-based scores, and thus, the weighting methods may be used interchangeably to calculate total scores