Über Modifikationen bei Cyanophyceen

Zusammenfassung Die Wirkung der geprüften Substanzen: 5 Farbstoffe, 2 Alkaloide, Formaldehyd, -Indolylessigsäure, Kupfersulfat, beschränkt sich fast ganz auf unspezifische Wachstumshemmung, die mit steigender Konzentration der Gifte zunimmt. Mitunter wird die Bildung der Heterocysten oder der Dauerzellen beeinträchtigt oder ganz unterdrückt, andererseits kann die Zahl der Het (beiCylindrospermum) auffallend vergrößert werden; die Gestalt der Dauerzellen kann etwas abgeändert werden. Morphogene Wirkungen an den Trichomen sind noch weniger ausgesprochen als sie auf starken Lösungen ungiftiger Mineralsalze beobachtet wurden. Die auffälligsten Reaktionen waren Verschmälerung und Verlängerung der Zellen beiCylindrospermum, Bildung von Gallertscheiden beiAnabaena variabilis, Zerfall der Trichome in Einzelzellen beiAnabaena apospora. Auch aus den am stärksten modifizierten und scheinbar geschädigten Trichomen gehen auf giftfreiem Nährboden wieder normale Lager hervor.Mit 14 TextabbildungenMit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Localization of the rat immunoglobulin heavy chain locus to chromosome 6

We have previously used rat/mouse somatic cell hybrids to localize the rat c-myc gene to chromosome 7 (Sümegi et al. 1983) and the rat immunoglobulin kappa locus to chromosome 4 (Perlmann et al. 1985). We now report that by utilizing rat/mouse somatic cell hybrids, we have localized the rat immunoglobulin heavy chain locus to chromosome 6.     

Macromolecular organization of chlorophyll a in aggregated chlorophyll ab protein complex as shown by circular dichroism at room and cryogenic temperatures

This report concerns the large circular dichroic (CD) signal of intact chloroplasts of higher plants. The CD spectra of chloroplasts are compared with the aggregated form of the light-harvesting chlorophyll $\text{a}\text{b}$ complex at 25°C and ?250°C. The light-harvesting chlorophyll aggregate has a CD of magnitude equal to or greater than chloroplasts, but of opposite sign, and it is not related to the CD of the unaggregated form, and hence its arrangement is an artefact compared to the arrangement in the chloroplast. We suggest that this preparation, which has pseudo-lamellar structure, is a clear example of a large CD signal being generated by macromolecular association. The asymmetry of organization in the chloroplast has an opposite sense to that of the aggregate, but affects only chlorophyll a, not chlorophyll b.     

Über Modifikationen bei Cyanophyceen

Ohne ZusammenfassungAuszug aus einer Dissertation der Naturwissenschaftlichen Fakultät der Universität München. — Zahlreiche Photographien sind im Nymphenburger Institut als Belege aufbewahrt.     

Identification of Multiple Novel Protein Biomarkers Shed by Human Serous Ovarian Tumors into the Blood of Immunocompromised Mice and Verified in Patient Sera

The most cancer-specific biomarkers in blood are likely to be proteins shed directly by the tumor rather than less specific inflammatory or other host responses. The use of xenograft mouse models together with in-depth proteome analysis for identification of human proteins in the mouse blood is an under-utilized strategy that can clearly identify proteins shed by the tumor. In the current study, 268 human proteins shed into mouse blood from human OVCAR-3 serous tumors were identified based upon human vs. mouse species differences using a four-dimensional plasma proteome fractionation strategy. A multi-step prioritization and verification strategy was subsequently developed to efficiently select some of the most promising biomarkers from this large number of candidates. A key step was parallel analysis of human proteins detected in the tumor supernatant, because substantially greater sequence coverage for many of the human proteins initially detected in the xenograft mouse plasma confirmed assignments as tumor-derived human proteins. Verification of candidate biomarkers in patient sera was facilitated by in-depth, label-free quantitative comparisons of serum pools from patients with ovarian cancer and benign ovarian tumors. The only proteins that advanced to multiple reaction monitoring (MRM) assay development were those that exhibited increases in ovarian cancer patients compared with benign tumor controls. MRM assays were facilely developed for all 11 novel biomarker candidates selected by this process and analysis of larger pools of patient sera suggested that all 11 proteins are promising candidate biomarkers that should be further evaluated on individual patient blood samples.     

Diastereomer Interconversion via Enolization: A Case Study

The three‐component reaction of indole, isobutyraldehyde, and methyl acetoacetate affords methyl 2‐(acetyl)‐3‐(1H‐indol‐3‐yl)‐4‐methylpentanoate as a single diastereomer. To investigate the origin of the observed diastereoselectivity, the thermodynamics and kinetics of interconversion of diastereomers 1 and 2 in solution were studied by a combination of ¹H nuclear magnetic resonance (NMR) spectroscopy, high‐performance liquid chromatography (HPLC), mass spectrometry, and deuteration experiments. The results indicate that interconversion is both acid‐ and base‐catalyzed, and that the alpha carbon is the only stereolabile center in the molecule. The evidence points to an enolization mechanism for the interconversion process. The selective precipitation of 1 in the presence of the equilibrium 1 ? 2 eventually results in the exclusive formation of 1 (crystallization‐induced asymmetric transformation). Chirality 27:779–783, 2015. © 2015 Wiley Periodicals, Inc.     

Long‐term effects of climate change on carbon storage and tree species composition in a dry deciduous forest

Forest vegetation and soils have been suggested as potentially important sinks for carbon (C) with appropriate management and thus are implicated as effective tools in stabilizing climate even with increasing anthropogenic release of CO₂. Drought, however, which is often predicted to increase in models of future climate change, may limit net primary productio (NPP) of dry forest types, with unknown effects on soil C storage. We studied C dynamics of a deciduous temperate forest of Hungary that has been subject to significant decreases in precipitation and increases in temperature in recent decades. We resampled plots that were established in 1972 and repeated the full C inventory by analyzing more than 4 decades of data on the number of living trees, biomass of trees and shrubs, and soil C content. Our analyses show that the decline in number and biomass of oaks started around the end of the 1970s with a 71% reduction in the number of sessile oak stems by 2014. Projected growth in this forest, based on the yield table's data for Hungary, was 4.6 kg C/m². Although new species emerged, this new growth and small increases in oak biomass resulted in only 1.9 kg C/m² increase over 41 years. The death of oaks increased inputs of coarse woody debris to the surface of the soil, much of which is still identifiable, and caused an increase of 15.5%, or 2.6 kg C/m², in the top 1 m of soil. Stability of this fresh organic matter input to surface soil is unknown, but is likely to be low based on the results of a colocated woody litter decomposition study. The effects of a warmer and drier climate on the C balance of forests in this region will be felt for decades to come as woody litter inputs decay, and forest growth remains impeded.