Thrombozytäre Serotoninkonzentration und Serotoninaufnahme bei Kindern und Jugendlichen: Korrelation zu depressivem, agressivem und suizidalem Verhalten

Bei 145 stationären Patienten der Kinder- und Jugendpsychiatrie der FSU Jena (4 bis 19 Jahre) wurden die thrombozytäre Serotoninkonzentration, sowie Maximalgeschwindigkeit Vmax und Affinitätskonstante Km des Serotonintransportes in die Thrombozyten anhand des Thrombozytenmodells bestimmt. Zeitnah wurden bei einem Teil der Patienten die Ausprägung depressiver (DIKJ) und aggressiver (EAS, FAF) Symptome testpsychologisch erhoben sowie Angaben über die Suizidalität erfasst). Es bestand eine negative Korrelation zwischen thrombozytärem Serotonin und dem Depressivitätsgrad. Unabhängig von der klinischen Diagnose ergaben sich signifikant niedrigere Serotoninkonzentrationen bei den Kindern und Jugendlichen, die unmittelbar vor der stationären Aufnahme einen Suizidversuch unternommen hatten. Hier waren zudem die Aufnahmeparameter Vmax und Km im Trend vermindert. Die vorliegenden Untersuchungen stützen die Auffassung, dass Depressivität in der Kindheit und Jugend mit einem Mangel an Serotonin im Thrombozyten und möglicherweise in zentralen Strukturen verbunden ist und ein relatives Defizit an Serotonin ein Suizidalitätsmarker sein könnte. Die serotonergen Veränderungen erwiesen sich eher als symptomabhängig, als dass sie nosologischen, diagnoseorientierten Kriterien folgten

Chromosomale Veränderungen oberflächlicher Harnblasenkarzinome hinsichtlich ihrer Rezidivität und Multifokalität

Harnblasenkarzinome sind die zweithäufigsten Tumore des Urogenitaltraktes und rezidivieren auch in oberflächlichen Stadien häufig. Die vorliegende Arbeit untersucht einen möglichen Zusammenhang chromosomaler Veränderungen oberflächlicher Harnblasenkarzinome pTaG1-2 hinsichtlich deren Rezidivhäufigkeit, der rezidivfreien Zeit und der Multifokalität dieser Tumore. Dazu wurde die Methode der Vergleichenden Genomischen Hybridisierung (CGH- Comparative Genomic Hybridization) angewandt. Es zeigte sich, dass Tumoren mit abnehmender durchschnittlicher rezidivfreier Zeit deutlich mehr Gesamtaberrationen. Tumoren mit einem kurzen Rezidivintervall hatten häufiger Verluste am Chromosom 11 sowie Zugewinne an den Chromosomen 1, 11 und 17. Die multifokalen Tumoren bildeten im Gegensatz zu den monofokalen vermehrt Zugewinne am Chromosom 1 sowie Verluste an 8p, 10q und Chromosom 11 aus. Weiterhin zeigten Tumore weiblicher Patienten deutlich mehr Verluste am Chromosom 10 als männliche Patienten. Somit können chromosomale Veränderungen gezeigt werden, welche Hinweise auf den klinischen Verlauf oberflächlicher Harnblasenkarzinome geben können

Mississippi River discharge over the last ~560,000years — Indications from X-ray fluorescence core-scanning

The long term history of terrigenous flux to the Gulf of Mexico via the Mississippi River is hardly known. We here present geochemical and sedimentological data to approximate the varying Mississippi River sediment influx into the northeastern Gulf of Mexico (GoM) over the last six glacial-interglacial cycles (MIS 1 to 14). Our study is based on the IMAGES sediment core MD02-2576 that was recovered from the DeSoto Canyon and is located ~ 200 km south to the recent Mississippi River delta and ~ 150 km east of the recent coastline of Florida. Concentrations of siliciclastic elements in bulk sediment samples were estimated from XRF scanning and calibrated by single bulk XRF-analyses. Elemental ratios of the sedimentary record correspond to ratios from the Mississippi River catchment rather than to the core close Alabama and Mobile River catchments. The siliciclastic major element potassium (K) with enhanced surface concentrations in the northwestern Mississippi River catchment shows varying occurrence downcore and here serves as a proxy for Mississippi River sediment discharge variability. Changes in sedimentation rate and magnetic susceptibility further support the variations in Mississippi River influx. Our data were compared with Mississippi River terrestrial archives in the form of loess and terrace deposits that back up our interpretations of enhanced glacial phase Mississippi River influx triggered by strengthened fluvial river runoff and changing fluvial and ice sheet dynamics. Mississippi River influx was at a maximum during glacial MIS 2/3, MIS 8 and MIS 10. Late glacial MIS 6 deviates from this pattern being a period of reduced Mississippi River influx at the core location, probably due to a westward shift of the Mississippi River delta

A high-resolution belemnite geochemical analysis of Early Cretaceous (Valanginian-Hauterivian) environmental and climatic perturbations

International audienceThe Early Cretaceous Weissert event, characterized by a positive carbon isotope excursion and coincident with the Paraná-Etendeka volcanism, saw a biogeochemical chain of events that ultimately led to an increase in carbon burial. A conclusive link between the Paraná-Etendeka volcanism and its impact upon the environment remains, however, elusive. Here we reconstruct temperature through the Weissert event from Mg/Ca ratios of belemnites from the Vocontian Trough (France) and SE Spain and use carbon isotopes to link our temperature reconstruction to marine records of carbon cycling. We provide evidence that the Paraná-Etendeka volcanism, unlike some large igneous provinces, did not cause a climate warming. The case can be made for cooling in the last stages of the Weissert event, which possibly reflects substantial CO 2 drawdown. In the absence of warming and consequent accelerated hydrological cycling and the relatively long duration of the eruptive phase of the Paraná-Etendeka, an alternate trigger for increased fertilization of the oceans is implicated

Carbon cycle history through the Jurassic–Cretaceous boundary: A new global δ13C stack

publisher: Elsevier articletitle: Carbon cycle history through the Jurassic–Cretaceous boundary: A new global δ13C stack journaltitle: Palaeogeography, Palaeoclimatology, Palaeoecology articlelink: http://dx.doi.org/10.1016/j.palaeo.2016.03.016 content_type: article copyright: Copyright © 2016 Published by Elsevier B.V

Biotic and environmental dynamics through the Late Jurassic-Early Cretaceous transition: evidence for protracted faunal and ecological turnover

The Late Jurassic to Early Cretaceous interval represents a time of environmental upheaval and cataclysmic events, combined with disruptions to terrestrial and marine ecosystems. Historically, the Jurassic/Cretaceous (J/K) boundary was classified as one of eight mass extinctions. However, more recent research has largely overturned this view, revealing a much more complex pattern of biotic and abiotic dynamics than has previously been appreciated. Here, we present a synthesis of our current knowledge of Late Jurassic–Early Cretaceous events, focusing particularly on events closest to the J/K boundary. We find evidence for a combination of short-term catastrophic events, large-scale tectonic processes and environmental perturbations, and major clade interactions that led to a seemingly dramatic faunal and ecological turnover in both the marine and terrestrial realms. This is coupled with a great reduction in global biodiversity which might in part be explained by poor sampling. Very few groups appear to have been entirely resilient to this J/K boundary ‘event’, which hints at a ‘cascade model’ of ecosystem changes driving faunal dynamics. Within terrestrial ecosystems, larger, more-specialised organisms, such as saurischian dinosaurs, appear to have suffered the most. Medium-sized tetanuran theropods declined, and were replaced by larger-bodied groups, and basal eusauropods were replaced by neosauropod faunas. The ascent of paravian theropods is emphasised by escalated competition with contemporary pterosaur groups, culminating in the explosive radiation of birds, although the timing of this is obfuscated by biases in sampling. Smaller, more ecologically diverse terrestrial non-archosaurs, such as lissamphibians and mammaliaforms, were comparatively resilient to extinctions, instead documenting the origination of many extant groups around the J/K boundary. In the marine realm, extinctions were focused on low-latitude, shallow marine shelf-dwelling faunas, corresponding to a significant eustatic sea-level fall in the latest Jurassic. More mobile and ecologically plastic marine groups, such as ichthyosaurs, survived the boundary relatively unscathed. High rates of extinction and turnover in other macropredaceous marine groups, including plesiosaurs, are accompanied by the origin of most major lineages of extant sharks. Groups which occupied both marine and terrestrial ecosystems, including crocodylomorphs, document a selective extinction in shallow marine forms, whereas turtles appear to have diversified. These patterns suggest that different extinction selectivity and ecological processes were operating between marine and terrestrial ecosystems, which were ultimately important in determining the fates of many key groups, as well as the origins of many major extant lineages. We identify a series of potential abiotic candidates for driving these patterns, including multiple bolide impacts, several episodes of flood basalt eruptions, dramatic climate change, and major disruptions to oceanic systems. The J/K transition therefore, although not a mass extinction, represents an important transitional period in the co-evolutionary history of life on Earth