Über einen energieunabhängigen Me2+-H+-Austausch in der Auβenmembran von Rattenlebermitochondrien und seine Beziehungen zum energieunabhängigen Me+-H+-Austausch

AbstractIntact mitochondria are able to bind monovalent and divalent metal cations and to release protons in an energy-independent exchange process. Directly accessible binding sites exist in the outer membrane. They seem to be identical for monovalent and divalent metal ions. The inner membrane-matrix-fraction possesses exchange sites after ultrasonic disruption only for monovalent cations, but not for divalent cations

Über einen energieunabhängigen austausch der alkali-ionen Li+, Na+, K+, Rb+ und Cs+ GEGEN H+ in der membran intakter und desintegrierter rattenlebermitochondrien

Abstract1.1. The energy-independent exchange of alkali metal cations against protons was investigated in intact and disintegrated mitochondria. The exchange is not specific for different alkali metal ions.2.2. In intact mitochondria the apparent Km for the energy-independent exchange range from 5 to 25 mM (Cs+, Rb+, K+ 5–10 mM; Na+ 15 mM; Li+ 20 mM). At all ions studied the maximum release of protons was 15–20 nval/mg protein.3.3. In disintegrated mitochondria there are no differences between the alkali metal ions (apparent Km 30 mM; maximum H+-release 50 nval/mg protein).4.4. Directly accessible binding sites seem to exist in the outer membrane. Binding sites in the inner membrane are accessible only after disintegration, but not after addition of valinomycin + rotenone

Increased risk of venous thromboembolism in patients with acute leukaemia

Patients with malignancies have an increased risk for venous thromboembolisms (VTE), but data on patients with acute leukaemia are very limited so far. We found VTE in 12% of 455 patients with acute leukaemia, half of which occurred in association with central venous catheters, with equal risk of ALL and AML

Asymmetric response of forest and grassy biomes to climate variability across the African Humid Period : influenced by anthropogenic disturbance?

A comprehensive understanding of the relationship between land cover, climate change and disturbance dynamics is needed to inform scenarios of vegetation change on the African continent. Although significant advances have been made, large uncertainties exist in projections of future biodiversity and ecosystem change for the world's largest tropical landmass. To better illustrate the effects of climate–disturbance–ecosystem interactions on continental‐scale vegetation change, we apply a novel statistical multivariate envelope approach to subfossil pollen data and climate model outputs (TraCE‐21ka). We target paleoenvironmental records across continental Africa, from the African Humid Period (AHP: ca 14 700–5500 yr BP) – an interval of spatially and temporally variable hydroclimatic conditions – until recent times, to improve our understanding of overarching vegetation trends and to compare changes between forest and grassy biomes (savanna and grassland). Our results suggest that although climate variability was the dominant driver of change, forest and grassy biomes responded asymmetrically: 1) the climatic envelope of grassy biomes expanded, or persisted in increasingly diverse climatic conditions, during the second half of the AHP whilst that of forest did not; 2) forest retreat occurred much more slowly during the mid to late Holocene compared to the early AHP forest expansion; and 3) as forest and grassy biomes diverged during the second half of the AHP, their ecological relationship (envelope overlap) fundamentally changed. Based on these asymmetries and associated changes in human land use, we propose and discuss three hypotheses about the influence of anthropogenic disturbance on continental‐scale vegetation change