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Neurons which lose part of their input respond with a compensatory increase in excitatory synaptic strength. This observation is of particular interest in the context of neurological diseases, which are accompanied by the loss of neurons and subsequent denervation of connected brain regions. However, while the cellular and molecular mechanisms of pharmacologically induced homeostatic synaptic plasticity have been identified to a certain degree, denervation-induced homeostatic synaptic plasticity remains not well understood. Here, we employed the entorhinal denervation in vitro model to study the role of tumor necrosis factor alpha (TNFα) on changes in excitatory synaptic strength of mouse dentate granule cells following partial deafferentation. Our experiments disclose that TNFα is required for the maintenance of a compensatory increase in excitatory synaptic strength at 3–4 days post lesion (dpl), but not for the induction of synaptic scaling at 1–2 dpl. Furthermore, laser capture microdissection combined with quantitative PCR demonstrates an increase in TNFα-mRNA levels in the denervated zone, which is consistent with our previous finding on a local, i.e., layer-specific increase in excitatory synaptic strength at 3–4 dpl. Immunostainings for the glial fibrillary acidic protein and TNFα suggest that astrocytes are a source of TNFα in our experimental setting. We conclude that TNFα-signaling is a major regulatory system that aims at maintaining the homeostatic synaptic response of denervated neurons.
Der diesjährige 8. Trockenrasen-Sonderteil von Tuexenia beginnt mit einen Bericht über die aktuellen Aktivitäten der European Dry Grassland Group (EDGG). Zunächst geben wir einen Überblick über die Entwicklung der Mitgliederzahl und den aktuellen Vorstand, der im Mai 2013 gewählt wurde. Dann berichten wir vom letzten European Dry Grassland Meeting in Prespa (Griechenland, 2012) und informieren über künftige Tagungen und Forschungsexpeditionen der EDGG. Schließlich war und ist die EDGG sehr aktiv darin, Special Features in internationalen Fachzeitschriften herauszugeben. Im zweiten Teil des Vorwortes geben wir eine Einführung zu den sechs Artikeln des diesjährigen Trockenrasen-Sonderteils: Zwei davon beschäftigen sich Biodiversitätsanalyen von Grasland-Ökotonen in einer Flusslandschaft in Lettland bzw. von brachgefallenen Alvar-Trockenrasen in Estland. Der dritte Artikel behandelt die Ökologie und Vergesellschaftung einer Grassippe (Avenula adsurgens subsp. adsurgens) im brachgefallenen, montanen Grasland der Karpaten (Slowakei). Die letzten drei Artikel schließlich sind der Beschreibung und Syntaxonomie von Trockenrasen gewidmet: Zwei davon bilden den Start einer neuen Serie über die pannonischen Trockenrasen Österreichs (Allgemeine Einführung und Trockenrasen des Wienerwalds), während der letzte die Ergebnisse der dritten EDGG-Forschungsexpedition im Jahr 2011 nach Bulgarien präsentiert. Schließlich geben wir einen Ausblick über künftige Pläne für das Special Feature.
Introduction: We examined if a combination of proliferation markers and estrogen receptor (ER) activity could predict early versus late relapses in ER-positive breast cancer and inform the choice and length of adjuvant endocrine therapy.
Methods: Baseline affymetrix gene-expression profiles from ER-positive patients who received no systemic therapy (n = 559), adjuvant tamoxifen for 5 years (cohort-1: n = 683, cohort-2: n = 282) and from 58 patients treated with neoadjuvant letrozole for 3 months (gene-expression available at baseline, 14 and 90 days) were analyzed. A proliferation score based on the expression of mitotic kinases (MKS) and an ER-related score (ERS) adopted from Oncotype DX® were calculated. The same analysis was performed using the Genomic Grade Index as proliferation marker and the luminal gene score from the PAM50 classifier as measure of estrogen-related genes. Median values were used to define low and high marker groups and four combinations were created. Relapses were grouped into time cohorts of 0-2.5, 0-5, 5-10 years.
Results: In the overall 10 years period, the proportional hazards assumption was violated for several biomarker groups indicating time-dependent effects. In tamoxifen-treated patients Low-MKS/Low-ERS cancers had continuously increasing risk of relapse that was higher after 5 years than Low-MKS/High-ERS cancers [0 to 10 year, HR 3.36; p = 0.013]. High-MKS/High-ERS cancers had low risk of early relapse [0-2.5 years HR 0.13; p = 0.0006], but high risk of late relapse which was higher than in the High-MKS/Low-ERS group [after 5 years HR 3.86; p = 0.007]. The High-MKS/Low-ERS subset had most of the early relapses [0 to 2.5 years, HR 6.53; p < 0.0001] especially in node negative tumors and showed minimal response to neoadjuvant letrozole. These findings were qualitatively confirmed in a smaller independent cohort of tamoxifen-treated patients. Using different biomarkers provided similar results.
Conclusions: Early relapses are highest in highly proliferative/low-ERS cancers, in particular in node negative tumors. Relapses occurring after 5 years of adjuvant tamoxifen are highest among the highly-proliferative/high-ERS tumors although their risk of recurrence is modest in the first 5 years on tamoxifen. These tumors could be the best candidates for extended endocrine therapy.
Background: Simultaneous pancreas kidney transplantation (SPK), pancreas transplantation alone (PTA) or pancreas transplantation after kidney (PAK) are the only curative treatment options for patients with type 1 (juvenile) diabetes mellitus with or without impaired renal function. Unfortunately, transplant waiting lists for this indication are increasing because the current organ acceptability criteria are restrictive; morbidity and mortality significantly increase with time on the waitlist. Currently, only pancreas organs from donors younger than 50 years of age and with a body mass index (BMI) less than 30 are allocated for transplantation in the Eurotransplant (ET) area. To address this issue we designed a study to increase the available donor pool for these patients.
Methods/Design: This study is a prospective, multicenter (20 German centers), single blinded, non-randomized, two armed trial comparing outcome after SPK, PTA or PAK between organs with the currently allowed donor criteria versus selected organs from donors with extended criteria. Extended donor criteria are defined as organs procured from donors with a BMI of 30 to 34 or a donor age between 50 and 60 years. Immunosuppression is generally standardized using induction therapy with Myfortic, tacrolimus and low dose steroids. In principle, all patients on the waitlist for primary SPK, PTA or PAK are eligible for the clinical trial when they consent to possibly receiving an extended donor criteria organ. Patients receiving an organ meeting the current standard criteria for pancreas allocation (control arm) are compared to those receiving extended criteria organ (study arm); patients are blinded for a follow-up period of one year. The combined primary endpoint is survival of the pancreas allograft and pancreas allograft function after three months, as an early relevant outcome parameter for pancreas transplantation.
Discussion: The EXPAND Study has been initiated to investigate the hypothesis that locally allocated extended criteria organs can be transplanted with similar results compared to the currently allowed standard ET organ allocation. If our study shows a favorable comparison to standard organ allocation criteria, the morbidity and mortality for patients waiting for transplantation could be reduced in the future.
Trial registered at: NCT01384006
Reintroductions of plant species are increasingly popular in conservation practice. Steppe grasslands contain many rare and endangered plant species that are potential objects for such reintroductions. Most reintroduction projects, however, can only target a restricted number of species, which raises the question of how species should be prioritised. Here, we present a method to select priority species for reintroduction based on species' characteristics that are widely used in conservation practice. We first determined the local species pool containing those vascular plant species that occurred both in our target region (Thuringia, Germany) and target habitat (steppe grasslands), yielding 369 species. With the help of an a priori filter that selected currently endangered species with limited distribution, 136 potential target species were determined. These potential target species had experienced stronger decline, had a narrower phytosociological amplitude and were more likely to be species of the Festuco-Brometea class and the Festucetalia valesiacae order than non-target species. Potential target species were then ranked by a points system based on ten conservation-relevant characteristics of the species from the categories "threat and protection status", "distribution and decline", and "habitat affiliation". In the ranking, six steppe grassland plant species (Astragalus exscapus, Bothriochloa ischaemum, Prunella laciniata, Pulsatilla pratensis subsp. nigricans, Scorzonera purpurea, and Seseli hippomarathrum) achieved the highest scores. An additional seven species not specifically characteristic for steppe grasslands also scored highly. A post hoc evaluation of these 13 highest scoring species based on additional conservation criteria left five species (Astragalus exscapus, Linum leonii, Orchis morio, Pulsatilla pratensis subsp. nigricans and Scorzonera purpurea) as species with highest priority for reintroductions and another five species as highly suitable for reintroductions. Associations between the ranking order and different ranking criteria revealed that a species’ threat and rarity in Thuringia and its protection status had the highest representation in the ranking, followed by threat in Germany, regional decline and habitat affiliation. In contrast, international threat and responsibility of Thuringia for its conservation had only low representation in the ranking, probably because these characteristics applied to only a few species. The ranking list gives a selection of species for reintroductions, which combined with additional information based on comprehensive local and floristic knowledge, allows the identification of the species with the highest priority. Our method can be transferred to other regions or habitat types.
Der diesjährige 9. Trockenrasen-Sonderteil von Tuexenia beginnt mit einem Bericht über die aktuellen Aktivitäten der European Dry Grassland Group (EDGG). Zunächst geben wir einen Überblick über die Entwicklung der Mitgliederzahl. Dann berichten wir vom letzten European Dry Grassland Meeting in Zamość (Polen, 2013) und vom letzten European Dry Grassland Field Workshop in Chakassien (Russland, 2013) und informieren über künftige Veranstaltungen der EDGG. Anschließend erläutern wir die Publikationsaktivitäten der EDGG. Im zweiten Teil des Editorials geben wir eine Einführung zu den fünf Artikeln des diesjährigen Trockenrasen-Sonderteils: Zwei davon beschäftigen sich mit der Syntaxonomie von Trockenrasen in Osteuropa: Der eine Artikel präsentiert erstmalig eine nach internationalen Nomenklaturregeln gültige Liste der Trockenrasengesellschaften Serbiens während der andere die Ergebnisse des zweiten EDGG-Field Workshop 2010 nach Podolien (Ukraine) vorstellt. Im dritten Artikel werden kryophytische Steppen in Südsibirien (Russland) analysiert. Der vierte Artikel analysiert in Böhmen (Tschechien) die bestimmenden Kräfte für Artenreichtum und Artenzusammensetzung der Trockenrasen. Der fünfte Artikel befasst sich mit der Auswahl von Wiederansiedlungsarten am Beispiel der Steppenrasen in Thüringen (Deutschland).
We present the data of the 2nd research expedition of the European Dry Grassland Group (EDGG), which was conducted in 2010 in Central Podolia, Ukraine. The aim was to collect plot data to compare Ukrainian dry grasslands with those of other parts of Europe in terms of syntaxonomy and biodiversity. We sampled 21 nested-plot series (0.0001–100 m2) and 184 normal plots (10 m2) covering the full variety of dry grassland types occurring in the study region. For all plots, we recorded species composi-tion of terrestrial vascular plants, bryophytes and lichens, while for the 226 10-m2 plots we estimated and measured percentage cover of all species, structural, topographic, soil and landuse parameters. The 10-m² plots were used for phytosociological classification based on iteratively refined TWINSPAN classification as well as for DCA ordination. Differences between the derived vegetation types with respect to environmental conditions and species richness were assessed with ANOVAs. We assigned our plots to nine association-level units but refrained from placing them into formal associations with two exceptions. In the study area, dry grasslands of the Festuco-Brometea were far more common than those of the Koelerio-Corynephoretea. Among the Festuco-Brometea, xeric Festucetalia valesiacae grasslands were more frequent and represented by the Festucion valesiacae (2 associations, including the Allio taurici-Dichanthietum ischaemi ass. nova) and the Stipion lessingianae (1) compared to the Brachypodietalia pinnati with the Agrostio vinealis-Avenulion schellianae (3). The Koelerio-Corynephoretea were represented by three associations, each from a different order and alliance: basiphilous outcrops (Alysso alyssoidis-Sedetalia: Alysso alyssoidis-Sedion?), acidophilous outcrops (Sedo-Scleranthetalia: Veronico dillenii-Sedion albi?) and mesoxeric sandy grasslands (Trifolio arvensis-Festucetalia ovinae: Agrostion vinealis). We discuss the issue of the mesoxeric order Galietalia veri placed within the Molinio-Arrhenatheretea by Ukrainian authors and conclude that the content of that order would probably be better placed in the mesoxeric orders of the Koelerio-Corynephoretea and Festuco-Brometea. Other syntaxonomic questions could not be solved with our geographically limited dataset and await a supraregional analysis, e.g. whether the Ukrainian outcrop communities should be assigned to the same alliances as known from Central Europe or rather represent new vicariant units. The analysis of the biodiversity patterns showed that at a grain size of 10 m2, Podolian Koelerio-Corynephoretea communities were overall richer than Festuco-Brometea communities (46.4 vs. 40.6 species). This difference was due to the Koelerio-Corynephoretea containing twice as many bryophytes and nine times more lichens, while vascular plant species richness did not differ significantly between classes. The orders within the classes showed no real differences in species richness. The richness patterns observed in Podolia were almost the opposite of those usually found in dry grasslands, where Brachypodietalia pinnati are richer than Festucetalia valesiacae, and these richer than stands of the Koelerio-Corynpehoretea – and we do not have a good explanation for these idiosyncrasies. In conclusion, Podolian dry grasslands behave quite unexpectedly regarding biodiversity, and their syntaxonomy is still poorly understood. These knowledge gaps can only be addressed with supranational analyses based on comprehensive datasets.
Heterogenous subtypes of breast cancer need to be analyzed separately. Pooling of datasets can provide reasonable sample sizes but dataset bias is an important concern. We assembled a combined dataset of 579 Affymetrix microarrays from triple negative breast cancer (TNBC) in Gene Expression Omnibus (GEO) series GSE31519. We developed a method for selecting comparable datasets and to control for the amount of dataset bias of individual probesets.
MTO1-deficient mouse model mirrors the human phenotype showing complex I defect and cardiomyopathy
(2014)
Recently, mutations in the mitochondrial translation optimization factor 1 gene (MTO1) were identified as causative in children with hypertrophic cardiomyopathy, lactic acidosis and respiratory chain defect. Here, we describe an MTO1-deficient mouse model generated by gene trap mutagenesis that mirrors the human phenotype remarkably well. As in patients, the most prominent signs and symptoms were cardiovascular and included bradycardia and cardiomyopathy. In addition, the mutant mice showed a marked worsening of arrhythmias during induction and reversal of anaesthesia. The detailed morphological and biochemical workup of murine hearts indicated that the myocardial damage was due to complex I deficiency and mitochondrial dysfunction. In contrast, neurological examination was largely normal in Mto1-deficient mice. A translational consequence of this mouse model may be to caution against anaesthesia-related cardiac arrhythmias which may be fatal in patients.
Background: Alzheimer's disease is a common debilitating dementia with known heritability, for which 20 late onset susceptibility loci have been identified, but more remain to be discovered. This study sought to identify new susceptibility genes, using an alternative gene-wide analytical approach which tests for patterns of association within genes, in the powerful genome-wide association dataset of the International Genomics of Alzheimer's Project Consortium, comprising over 7 m genotypes from 25,580 Alzheimer's cases and 48,466 controls.
Principal findings: In addition to earlier reported genes, we detected genome-wide significant loci on chromosomes 8 (TP53INP1, p = 1.4×10−6) and 14 (IGHV1-67 p = 7.9×10−8) which indexed novel susceptibility loci.
Significance: The additional genes identified in this study, have an array of functions previously implicated in Alzheimer's disease, including aspects of energy metabolism, protein degradation and the immune system and add further weight to these pathways as potential therapeutic targets in Alzheimer's disease.