Stuck in time – a new Chaenothecopsis species with proliferating ascomata from Cunninghamia resin and its fossil ancestors in European amber

Resin protects wounded trees from microbial infection, but also provides a suitable substrate for the growth of highly specialized fungi. Chaenothecopsis proliferatus is described growing on resin of Cunninghamia lanceolata from Hunan Province, China. The new fungus is compared with extant species and two new fossil specimens from Eocene Baltic and Oligocene Bitterfeld ambers. The Oligocene fossil had produced proliferating ascomata identical to those of the newly described species and to other extant species of the same lineage. This morphology may represent an adaptation to growing near active resin flows: the proliferating ascomata can effectively rejuvenate if partially overrun by fresh, sticky exudate. Inward growth of fungal hyphae into resin has only been documented from Cenozoic amber fossils suggesting comparatively late occupation of resin as substrate by fungi. Still, resinicolous Chaenothecopsis species were already well adapted to their special ecological niche by the Eocene, and the morphology of these fungi has since remained remarkably constant.     

Repair of Left Ventricular Assist Device Driveline Damage Directly at the Transcutaneous Exit Site

With increasing support duration of cardiac assist devices, transcutaneous drivelines remain a weak point of the therapy. First, they can be an entry point for infections, and second, cable lesions and even electrical failures due to material fatigue and eventual carelessness can occur. We report a case of a damaged outer sheath of a ventricular assist device driveline cable directly at the exit site, where the standard repair procedure with self‐fusing tape may lead to biocompatibility problems and irritation of the entrance through the skin. Therefore, a new procedure was developed using a special sleeve expander tool and a highly expandable latex tubing to stabilize the defect in a flexible and biocompatible manner. A patient experienced a fracture of the outer sheath of a HeartWare HVAD driveline directly at the skin entrance (approximately 15 mm long, 5 mm distal from the skin). The metal strands and the electrical functionality were yet not affected, therefore, a pump exchange was not indicated. After considering several conventional solutions for repair as not applicable, a new approach was developed: a sleeve expander tool was applied, which allowed radial stretching of the latex tubing. After preparations of the tool and the cable site, the pump was briefly disconnected, the tubing was moved over the connector and was released at the site of fracture. The problem could be solved by keeping the cable's flexibility and without additional risks to the skin. Within a still ongoing (5‐month) follow‐up, the skin entrance returned to perfect condition and no further intervention was necessary. In conclusion, this method allows a quick stabilization and repair of damaged driveline isolations even near the exit site, resulting in a biocompatible surface and consistent flexibility of the cable.     

Platelet-derived growth factor triggers PKA-mediated signalling by a redox-dependent mechanism in rat renal mesangial cells

Inflammatory glomerular kidney diseases are often accompanied with a massive production of reactive oxygen species (ROS) that affect the function of the glomerular filtration barrier and contribute to mesangiolysis via the induction of cell death in mesangial cells. Intriguingly, ROS also trigger fine-tuned signalling processes that affect gene expression and cell proliferation or migration. To define such redox-driven signalling devices, a proteomics approach was performed to identify the formation of protein complexes induced by ROS. To this end, protein lysates of human podocytes were treated with or without hydrogen peroxide (250 μM). Thereafter cell lysates were subjected to diagonal 2D gel electrophoresis and putative redox-affected proteins were analysed by MS/MS analysis. Among others, the regulatory subunit of protein kinase A (PKA) could be identified that forms homodimers under oxidative conditions. To evaluate whether ROS dependent dimerization of PKA also occurs in a more physiological setting, rat mesangial cells were treated with platelet-derived growth factor-BB (PDGF-BB) to induce ROS formation. This regimen resulted in a redox dependent dimerization of the R-subunits of PKA. To demonstrate whether PDGF-BB induced ROS formation affects PKA dependent pathways, the effects of PDGF-BB on phosphorylation of serine 157 of vasodilator stimulated protein (VASP) a classical target of PKA were analysed. Interestingly PDGF-BB induced VASP phosphorylation in a ROS dependent manner but independent of changes in cAMP levels. Taken together, we demonstrate a redox-mediated activation of PKA by PDGF-BB thus highlighting a physiological role of ROS as regulator of PKA activity in rat mesangial cells.     

Neurophysiology and the Problem of Human Free Will: A Case of “Nihil Sub Sole Novum”?

Over the last decade in Germany, a number of neuroscientists—and among them most prominently Wolf Singer—have claimed to be able to offer scientific evidence derived from neurophysiologic findings to conclusively negate the existence of human free will. In this paper, Singer’s position is examined according to its principal characteristics in order to answer the question whether it is a novel position as opposed to a position pertaining to one of the traditions of western philosophy and anthropology. Furthermore, we try to judge whether the neurobiological findings Singer and others use to justify their position are apt to satisfy the criteria for the presence of scientific evidence, i.e., if they are good reasons to believe that human will is unfree.     

The use of Ginkgo biloba in healthy elderly

To promote health-conscious behavior in the aging society and gain insight into the sources of knowledge on which preventive strategies are based, analyzing the behavior of elderly people who are recognized as highly health conscious may be useful. We focused on the use of Ginkgo biloba, which is commonly considered to be effective in preventing cognitive decline and dementia, among elderly adults. A total of 1,672 questionnaires were distributed among geriatric participants (60–94 years) who attended university lectures at 22 universities throughout Germany. Response rate was 36.1 %. We collected data on demographic characteristics, preventive strategies (use of Ginkgo and other supplements), health-conscious behavior, sources of knowledge concerning health behavior, and factors associated with the participants’ concept of aging. The prevalence of Ginkgo use was 15.3 %. Ginkgo was assumed to be effective for cognitive enhancement and the treatment of cognitive decline by two thirds of the surveyed participants and one third believed Ginkgo to be effective for preventing dementia. Ginkgo use was significantly higher among participants using natural remedies and herbal and food supplements. The use of Ginkgo was recommended by physicians (57.3 %), chemists (16 %), and healthcare magazines (10.7 %). Food supplements were taken by 65.8 % of the sample: this percentage was significantly higher among subjects who exhibited health-conscious behavior. “Knowledge” about strategies to enhance cognition or prevent cognitive decline among the elderly do not appear to be evidence based. Thus, there is a need to establish reliable and independent sources of scientific information for healthcare professionals and the general public.