Age-related changes of apoptotic cell death in human lymphocytes

Apoptosis seems to be involved in immunosenescence associated with aging. Moreover, in lymphocytes (PBL) of patients with Alzheimer's disease, an increased susceptibility to the apoptotic pathway has been described possibly due to impaired protection of oxidative stress. Accordingly, it seemed to be of particular interest to investigate the contribution of normal aging to the susceptibility from human lymphocytes to programmed cell death. We could show that PBL from elderly individuals (>60 years) accumulate apoptosing cells to a significant higher extent in spontaneous and activation-induced cell death compared to younger controls (<35 years). Treatment with the oxidative stressor 2-deoxy-D-ribose or with agonistic-CD95-antibody pronounced this effect even more implicating a higher sensitivity to reactive oxygen species and a higher functional CD95 expression, respectively. In addition, expression of the activation markers HLA-DR and CD95 was significantly increased in CD3+-cells of aged subjects, while expression of CD25 did not seem to be affected by age. Expression of Bcl-2 was increased in aging and correlated with the number of apoptotic cells

Current use of Spatial Information Technology in Megacity Management

One objective of FIG Commission 3 focuses on promoting the use of Spatial Infrastructure Management (SIM)-tools at different administrative levels for decision makers and citizens to support the goals of participatory democracy. In this context FIG Commission 3 has set up the Working Group WG3.2 Spatial Data Infrastructures in Mega cities, which aims at identifying relevant spatial tools to support development and use of spatial data infrastructure (SDI) by city authorities in the world’s largest cities. The strategy of the work program emphasizes key problems of mega cities by reviewing SDI developments in existing mega cities, documenting case studies, including lessons learned about solutions for problems and should finally lead to a toolkit for use of best practises in SDI for managing mega cities. To complement the results of direct correspondence with administrations of mega cities one important part of this project concentrates on a background research of existing sources about overall use of SDI in mega cities. The objective of this paper is to discuss the results of an internet search concerning the use of Spatial Information Technology in the world’s currently existing mega cities. The search starts from a nationwide view on the execution and the progression status of SDI’s in the home countries of mega cities and zooms in to the specific aspects of spatial data management in the metropolitan areas of special interest. As a result we come to the conclusion, that current SDI development in mega cities covers the whole range from first stage conceptual ideas up to an almost complete operational SDI availability

Age-related increase of oxidative stress-induced apoptosis in mice prevention by Ginkgo biloba extract (EGb761)

Enhanced apoptosis and elevated levels of reactive oxygen species (ROS) play a major role in aging. In addition, several neurodegenerative diseases are associated with increased oxidative stress and apoptosis in neuronal tissue. Antioxidative treatment has neuro-protective effects. The aim of the present study was to evaluate changes of susceptibility to apoptotic cell death by oxidative stress in aging and its inhibition by the antioxidant Ginkgo biloba extract EGb761. We investigated basal and ROS-induced levels of apoptotic lymphocytes derived from the spleen in young (3 months) and old (24 months) mice. ROS were induced by 2-deoxy-D-ribose (dRib) that depletes the intracellular pool of reduced glutathione. Lymphocytes from aged mice accumulate apoptotic cells to a significantly higher extent under basal conditions compared to cells from young mice. Treatment with dRib enhanced this difference, implicating a higher sensitivity to ROS in aging. Apoptosis can be reduced in vitro by treatment with EGb761. In addition, mice were treated daily with 100mg/kg EGb761 per os over a period of two weeks. ROS-induced apoptosis was significantly reduced in the EGb761 group. Interestingly, this effect seemed to be more pronounced in old mice

Reduced antioxidant enzyme activity in brains of mice transgenic for human presenilin-1 with single or multiple mutations

Alzheimer's disease-related mutations in the presenilin-1 gene (PS1) are leading to an elevated production of neurotoxic beta-amyloid 1-42 and may additionally enhance oxidative stress. Here, we provide in vivo evidence indicating that brains of transgenic mice expressing different human Alzheimer-linked PS1 mutations exhibit a reduced activity of two antioxidant enzymes. For this purpose, mice transgenic for human PS1 and for single and multiple PS1 mutations were generated. Mice with multiple PS1 mutations showed a significantly decreased activity of the antioxidant enzymes Cu/Zn superoxide dismutase and glutathione reductase already at an age of 3-4 months. As expected, this effect was less pronounced for the mice with a single PS1 mutation. By contrast, animals bearing normal human PS1 showed significantly elevated enzyme activities relative to non-transgenic littermate controls

Detection of a conformational change in Gγ upon binding Gβ in living cells

AbstractInteraction induced changes in the conformation of proteins are frequently the molecular basis for the modulation of their activities. Although proteins perform their functions in cells, surrounded by many potential interaction partners, the studies of their conformational changes have been mainly restricted to in vitro studies. Ste4p (Gβ) and Ste18p (Gγ) are the subunits of a heterotrimeric G-protein in the yeast Saccharomyces cerevisiae. A split-ubiquitin based conformational sensor was used to detect a major structural rearrangement in Ste18p upon binding to Ste4p. Based on these in vivo results and the solved structure of the mammalian Gβγ, we propose that Gγ of yeast adopts an equally extended structure, which is only induced upon association with Gβ

Entwicklung eines Farbkalibrierungssystems für ein Mehrkamerasystem zur 3D Rekonstruktion von Personen

In diesem Paper werden drei Varianten zur Farbkalibrierung eines Mehrkamerasystems für die 3D-Rekonstruktion von Personen vorgestellt, um eine Generierung von fehlerfreien Texturen zu ermöglichen. Besonderer Fokus wird dabei auf die Anforderungen zum Einsatz eines konventionellen Referenzcharts in der Umgebung eines volumetrischen Videostudios gelegt. Im Rahmen der Masterarbeit konnte gezeigt werden, wie wichtig es ist, dass neben der farbmetrischen und lichttechnischen Stabilität der Leuchten eine identische Beleuchtung der Charts für alle Kameras gewährleistet wird. Als Alternative werden in Kürze zwei aktive, d.h. selbstleuchtende Kalibrierobjekte vorgestellt. Die erste Variante verwendet die RGBModule der verbauten Studioleuchten, das zweite sieht den Aufbau einer LED-Leuchte mit RGBA-Emitter vor

Effects of EGb 761® Ginkgo biloba extract on mitochondrial function and oxidative stress

As major sources of reactive oxygen species (ROS), mitochondrial structures are exposed to high concentrations of ROS and may therefore be particularly susceptible to oxidative damage. Mitochondrial damage could play a pivotal role in the cell death decision. A decrease in mitochondrial energy charge and redox state, loss of transmembrane potential (depolarization), mitochondrial respiratory chain impairment, and release of substances such as calcium and cytochrome c all contribute to apoptosis. These mitochondrial abnormalities may constitute a part of the spectrum of chronic oxidative stress in Alzheimer's disease. Accumulation of amyloid beta (Abeta) in form of senile plaques is also thought to play a central role in the pathogenesis of Alzheimer's disease mediated by oxidative stress. In addition, increasing evidence shows that Abeta generates free radicals in vitro, which mediate the toxicity of this peptide. In our study, PC12 cells were used to examine the protective features of EGb 761(definition see editorial) on mitochondria stressed with hydrogen peroxide and antimycin, an inhibitor of complex III. In addition, we investigated the efficacy of EGb 761 in Abeta-induced MTT reduction in PC12 cells. Moreover, we examined the effects of EGb 761 on ROS levels and ROS-induced apoptosis in lymphocytes from aged mice after in vivo administration. Here, we will report that EGb 761 was able to protect mitochondria from the attack of hydrogen peroxide, antimycin and Abeta. Furthermore, EGb 761 reduced ROS levels and ROS-induced apoptosis in lymphocytes from aged mice treated orally with EGb 761 for 2 weeks. Our data further emphasize neuroprotective properties of EGb 761, such as protection against Abeta-toxicity, and antiapoptotic properties, which are probably due to its preventive effects on mitochondria

Alzheimer's disease-like alterations in peripheral cells from presenilin-1 transgenic mice

Many cases of early-onset inherited Alzheimer's disease (AD) are caused by mutations in the presenilin-1 (PS1) gene. Expression of PS1 mutations in cell culture systems and in primary neurons from transgenic mice increases their vulnerability to cell death. Interestingly, enhanced vulnerability to cell death has also been demonstrated for peripheral lymphocytes from AD patients. We now report that lymphocytes from PS1 mutant transgenic mice show a similar hypersensitivity to cell death as do peripheral cells from AD patients and several cell culture systems expressing PS1 mutations. The cell death-enhancing action of mutant PS1 was associated with increased production of reactive oxygen species and altered calcium regulation, but not with changes of mitochondrial cytochrome c. Our study further emphasizes the pathogenic role of mutant PS1 and may provide the fundamental basis for new efforts to close the gap between studies using neuronal cell lines transfected with mutant PS1, neurons from transgenic animals, and peripheral cells from AD patients. Copyright 2001 Academic Press

Are landscape structures insurmountable barriers for foraging bees? A mark-recapture study with two solitary pollen specialist species

To investigate whether landscape structures act as insurmountable barriers for foraging bees, we conducted mark-recapture studies with two pollen-specialist solitary species. Foraging options of the bees were confined to host plant stands across different landscape structures. Differences in altitude of more than 130 m were overcome and forests covering a distance of up to 480 m were crossed by Chelostoma florisomne. A broad river and a motorway with intense traffic did not represent insurmountable barriers for Hoplitis adunca. For C. florisomne, total foraging distances of up to 650 m were measured, but foraging females were recorded predominantly on host plant patches available in relatively close vicinity to their nesting site. While landscape structures might impede foraging in endangered bees, the investigated landscape structures clearly did not act as insurmountable physical barriers for the two common solitary bee species tested in our stud