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3 results on '"Tim Laussmann"'

1. Dynamic monitoring of vital functions and tissue re-organization in Saturnia pavonia (Lepidoptera, Saturniidae) during final metamorphosis by non-invasive MRI

Author

Tim Laussmann, Paul Urspruch, Vera Flocke, Anton G. Windfelder, Hermann Aberle, Klaus Lunau, and Ulrich Flögel

Subjects
Medicine, Science
Abstract

Abstract Magnetic resonance imaging (MRI) is the key whole-body imaging technology for observing processes within a living object providing excellent resolution and contrast between soft tissues. In the present work, we exploited the non-destructive properties of MRI to track longitudinally the dynamic changes that take place in developing pupae of the Emperor Moth (Saturnia pavonia) during the last days before eclosion. While in diapause pupae, body fluid was almost homogeneously distributed over the internal compartments, as soon as wings, legs, flight muscles and the head region were fully developed, a significant redistribution of water levels occurred between thoracic and abdominal regions. During the last two days before eclosion, the developing moths transferred substantial amounts of liquid into the gut and the labial gland, and in case of females, into developing eggs. Concomitantly, the volume of the air sacs increased drastically and their expansion/compression became clearly visible in time-resolved MR images. Furthermore, besides ventilation of the tracheal system, air sacs are likely to serve as volume reservoir for liquid transfer during development of the moths inside their pupal case. In parallel, we were able to monitor noninvasively lipid consumption, cardiac activity and haemolymph circulation during final metamorphosis.

Published
2022
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2. Myocardial proteome analysis reveals reduced NOS inhibition and enhanced glycolytic capacity in areas of low local blood flow

Author

Tim Laussmann, Wolfgang Schlack, Christina Dominik Fingas, Jürgen Schrader, Ulrich K. M. Decking, Rolf Alexander Janosi, Georg Schlieper, and Anesthesiology

Subjects
Proteome, Hydrolases, Dehydrogenase, Biology, Arginine, Nitric Oxide, Biochemistry, Mass Spectrometry, Nitric oxide, Amidohydrolases, chemistry.chemical_compound, Dogs, Coronary Circulation, Genetics, Animals, Glycolysis, Electrophoresis, Gel, Two-Dimensional, Enzyme Inhibitors, Molecular Biology, Beta oxidation, Polyacrylamide gel electrophoresis, Phosphoglycerate kinase, Myocardium, Fatty Acids, Models, Cardiovascular, Molecular biology, Kinetics, chemistry, Myoglobin, Nitric Oxide Synthase, Asymmetric dimethylarginine, Energy Metabolism, Oxidation-Reduction, Biotechnology
Abstract

In the heart, in situ local myocardial blood flow (MBF) varies greater than 10-fold between individual areas and displays a spatially heterogeneous pattern. To analyze its molecular basis, we analyzed protein expression of low and high flow samples (300 mg, 150% of mean MBF, each n=30) of six beagle dogs by 2-D polyacrylamide gel electrophoresis (380 +/- 78 spots/gel). In low flow samples, dimethylarginine dimethylaminohydrolase (DDAH1) was increased greatly (+377%, compared with high flow samples). This increase resulted in a 75% reduction of asymmetric dimethylarginine (ADMA), the potent endogenous inhibitor of NO synthase, whereas eNOS showed no difference. Low flow samples exhibited enhanced expression of GAPDH (+89%) and phosphoglycerate kinase (+100%), whereas hydroxyacyl-CoA dehydrogenase, electron transfer flavoprotein, myoglobin, and desmin were decreased. Assessing local MBF on different days within 2 weeks revealed a high degree of MBF stability (r2 > 0.79). Thus, stable differences in local MBF are associated with significant differences in local gene and protein expression. In low flow areas, the increased DDAH1 reduces ADMA concentration and NOS inhibition, which strongly suggests enhanced NO formation. Low flow areas are also characterized by a higher glycolytic and a lower fatty acid oxidation capacity. Both the shift in substrate utilization and the rise in NO may contribute to the known lower oxygen consumption in these areas

Published
2002

3. Diphospho-myo-inositol phosphates in Dictyostelium and Polysphondylium: identification of a new bisdiphospho-myo-inositol tetrakisphosphate

Author

Komandla Malla Reddy, John R. Falck, K. Kishta Reddy, Günter Vogel, Tim Laussmann, and André Hansen

Subjects
Kinase, Stereochemistry, Inositol Phosphates, Biophysics, Stereoisomerism, Biochemistry, Dictyostelium discoideum, chemistry.chemical_compound, Structural Biology, Genetics, Animals, Inositol, Dictyostelium, Axenic, Nuclear Magnetic Resonance, Biomolecular, Molecular Biology, Polysphondylium, Phosphotransferases (Phosphate Group Acceptor), biology, Cell Biology, biology.organism_classification, Phosphotransferases (Alcohol Group Acceptor), chemistry, Myo-inositol, Enantiomer, Dictyosteliida
Abstract

The two major diphospho inositol phosphates from the axenic strain Dictyostelium discoideum AX2 were previously investigated and identified as 6-PP-InsP5 and 5,6-bis-PP-InsP4. In order to examine whether these findings are representative of Dictyostelids in general, five non-axenic wild-type species of Dictyostelium and two of Polysphondylium were studied. It was found that all of the Dictyostelium species exhibit similar patterns of diphospho inositol phosphates. By contrast, both of the Polysphondylium species contain 5-PP-InsP5 as the predominant isomer. Besides 5,6-bis-PP-InsP4, a new bis-PP-InsP4 was detected in Polysphondylium. This compound is either 1,5-bis-PP-InsP4 or its corresponding enantiomer 3,5-bis-PP-InsP5. The structures were elucidated by two-dimensional 1H-1H and 1H-31P NMR analysis. Additionally, they were confirmed using a specific 6-PP-InsP5-5-kinase from D. discoideum AX2 as an enantio-specific tool and enantiomerically pure reference standards.

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