Fluiddynamik des Kammerwassers beim chronischen einfachen Glaukom: Mechanismen der Drucknormalisierung durch ein künstliches Abflusssystem

Zusammenfassung: Die Wechselwirkung zwischen Kräften, Verteilung und Absorption des Kammerwassers im subkonjunktivalen Gewebe wird anhand eines kürzlich publizierten theoretischen Modells untersucht, das die Produktion von Flüssigkeit im Auge und deren Eliminierung durch das Trabekelwerk, das uveosklerale Gewebe und einen Shunt beschreibt. Zielgröße dabei ist der intraokulare Druck. Die Mechanismen von neu geschaffenen Abflusswegen werden mithilfe der Theorie der porösen Medien dargestellt, die sich auf ein Sickerkissen beziehen, das unter dem subkonjunktivalen Gewebe liegt. Die rechnerische Analyse basiert auf der Geometrie und den Parametern, die das Zu- und Abflusssystem charakterisieren. Diese sind durch die Produktion von Kammerwasser, den chirurgisch angelegten Abflusskanal, sodann durch die Resorption in den episkleralen Gefäßen und durch die hydraulischen Eigenschaften des subkonjunktivalen Gewebes und des Sickerkissens sowie durch dessen Geometrie gegeben. Anhand parametrischer Untersuchungen können klinische Befunde physikalisch begründet werde

Thyroid Dysplasia in Wistar Hannover GALAS Rats

Thyroid dysplasia was recognized in WistarHan GALAS rats and confirmed as a heritable congenital disorder. The gene or genes involved were not identified, but homozygous animals with thyroid dysplasia also exhibited stunted growth, had reduced pituitary gland growth hormone (GH) and were hypothyroid. Heterozygous animals exhibited thyroid dysplasia with normal thyroid hormonal homeostasis and no difference in the incidence of preneoplastic or neoplastic lesions in oncogenicity studies

Phosphorylation of phytochrome B inhibits light-induced signaling via accelerated dark reversion in Arabidopsis

The photoreceptor phytochrome B (phyB) interconverts between the biologically active Pfr (lmax = 730 nm) and inactive Pr (lmax = 660 nm) forms in a red/far-red–dependent fashion and regulates, as molecular switch, many aspects of lightdependent development in Arabidopsis thaliana. phyB signaling is launched by the biologically active Pfr conformer and mediated by specific protein–protein interactions between phyB Pfr and its downstream regulatory partners, whereas conversion of Pfr to Pr terminates signaling. Here, we provide evidence that phyB is phosphorylated in planta at Ser-86 located in the N-terminal domain of the photoreceptor. Analysis of phyB-9 transgenic plants expressing phospho-mimic and nonphosphorylatable phyB–yellow fluorescent protein (YFP) fusions demonstrated that phosphorylation of Ser-86 negatively regulates all physiological responses tested. The Ser86Asp and Ser86Ala substitutions do not affect stability, photoconversion, and spectral properties of the photoreceptor, but light-independent relaxation of the phyBSer86Asp Pfr into Pr, also termed dark reversion, is strongly enhanced both in vivo and in vitro. Faster dark reversion attenuates red light–induced nuclear import and interaction of phyBSer86Asp-YFP Pfr with the negative regulator PHYTOCHROME INTERACTING FACTOR3 compared with phyB–green fluorescent protein. These data suggest that accelerated inactivation of the photoreceptor phyB via phosphorylation of Ser-86 represents a new paradigm for modulating phytochrome-controlled signaling

Neighbor Detection Induces Organ-Specific Transcriptomes, Revealing Patterns Underlying Hypocotyl-Specific Growth.

In response to neighbor proximity, plants increase the growth of specific organs (e.g., hypocotyls) to enhance access to sunlight. Shade enhances the activity of Phytochrome Interacting Factors (PIFs) by releasing these bHLH transcription factors from phytochrome B-mediated inhibition. PIFs promote elongation by inducing auxin production in cotyledons. In order to elucidate spatiotemporal aspects of the neighbor proximity response, we separately analyzed gene expression patterns in the major light-sensing organ (cotyledons) and in rapidly elongating hypocotyls of Arabidopsis thaliana PIFs initiate transcriptional reprogramming in both organs within 15 min, comprising regulated expression of several early auxin response genes. This suggests that hypocotyl growth is elicited by both local and distal auxin signals. We show that cotyledon-derived auxin is both necessary and sufficient to initiate hypocotyl growth, but we also provide evidence for the functional importance of the local PIF-induced response. With time, the transcriptional response diverges increasingly between organs. We identify genes whose differential expression may underlie organ-specific elongation. Finally, we uncover a growth promotion gene expression signature shared between different developmentally regulated growth processes and responses to the environment in different organs

Flood retention in alpine catchments equipped with complex hydropower schemes - A case study of the upper Aare catchment in Switzerland

The simulation of run-off in alpine catchment areas is an important issue for the optimal operation of hydropower plants for normal flow conditions, but also during flood events. A semi-lumped numerical approach combines hydrological modelling and operation of hydraulic elements. It allows simulation of operating mode of complex storage hydropower plants and its impacts on the downstream river system for different scenarios. The modelling of the upper Aare catchment with the Oberhasli hydropower scheme in Switzerland is presented. The effect of the existing reservoirs and their management, taking into account preventive turbining, on flood routing in the Aare River upstream of Lake Brienz is presented for the 2005 and 1987 flood events. The enhancement project KWOplus, which contains a considerable increase of storage volume in the main reservoir as well as in turbining capacity, is estimated

An unusual case of suprascapular nerve neuropathy: a case report

<p>Abstract</p> <p>Introduction</p> <p>Suprascapular nerve neuropathy constitutes an unusual cause of shoulder weakness, with the most common etiology being nerve compression from a ganglion cyst at the suprascapular or spinoglenoid notch. We present a puzzling case of a man with suprascapular nerve neuropathy that may have been associated with an appendectomy. The case was attributed to nerve injury as the most likely cause that may have occurred during improper post-operative patient mobilization.</p> <p>Case presentation</p> <p>A 23-year-old Caucasian man presented to an orthopedic surgeon with a history of left shoulder weakness of several weeks' duration. The patient complained of pain and inability to lift minimal weight, such as a glass of water, following an appendectomy. His orthopedic clinical examination revealed obvious atrophy of the supraspinatus and infraspinatus muscles and 2 of 5 muscle strength scores on flexion resistance and external rotation resistance. Magnetic resonance imaging showed diffuse high signal intensity within the supraspinatus and infraspinatus muscles and early signs of minimal fatty infiltration consistent with denervation changes. No compression of the suprascapular nerve in the suprascapular or spinoglenoid notch was noted. Electromyographic studies showed active denervation effects in the supraspinatus muscle and more prominent in the left infraspinatus muscle. The findings were compatible with damage to the suprascapular nerve, especially the part supplying the infraspinatus muscle. On the basis of the patient's history, clinical examination, and imaging studies, the diagnosis was suspected to be associated with a possible traction injury of the suprascapular nerve that could have occurred during the patient's transfer from the operating table following an appendectomy.</p> <p>Conclusion</p> <p>Our case report may provide important insight into patient transfer techniques used by hospital personnel, may elucidate the clinical significance of careful movement of patients following general anesthesia, and may have important implications for patient safety techniques, including those outlined in the World Health Organization Surgical Safety Checklist program.</p

CWH43 is required for the introduction of ceramides into GPI anchors in Saccharomyces cerevisiae

After glycosylphosphatidylinositols (GPIs) are added to GPI proteins of Saccharomyces cerevisiae, the fatty acid in sn-2 of the diacylglycerol moiety can be replaced by a C26:0 fatty acid by a deacylation–reacylation cycle catalysed by Per1p and Gup1p. Furthermore the diacylglycerol moiety of the yeast GPI anchor can also be replaced by ceramides. CWH43 of yeast is homologous to PGAP2, a gene that recently was implicated in a similar deacylation reacylation cycle of GPI proteins in mammalian cells, where PGAP2 is required for the reacylation of monoradylglycerol-type GPI anchors. Here we show that mutants lacking CWH43 are unable to synthesize ceramide-containing GPI anchors, while the replacement of C18 by C26 fatty acids on the primary diacylglycerol anchor by Per1p and Gup1p is still intact. CWH43 contains the COG3568 metal hydrolase motif, which is found in many eukaryotic and prokaryotic enzymes. The conserved His 802 residue of this motif was identified as being essential for ceramide remodelling. Ceramide remodelling is not required for the normal integration of GPI proteins into the cell wall. All remodelling reactions are dependent on prior removal of the inositol-linked fatty acid by Bst1p