Untersuchungen zur Bedeutung der S-Transnitrosylierungs-Reaktion für die Bildung, den Metabolismus und die Vermittlung der biologischen Aktivitäten von NO und S-Nitroso-Substanzen

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Fossil carotenoids and paleolimnology of meromictic Mahoney Lake, British Columbia, Canada

Vertical distribution of fossil carotenoids in a sediment core from meromictic Mahoney Lake was studied. Besides okenone and demethylated okenone, lutein and zeaxanthin and-carotene isomers were identified. No carotenoids typical for purple nonsulfur or green sulfur bacteria were detected. The ratio of zeaxanthin to lutein (above 1:1 in all samples) indicates a dominance of cyanobacteria over green algae in the phytoplankton assemblages of the past. Okenone, which is found exclusively in Chromatiaceae, was the dominating carotenoid in all sediment zones. The oldest sediment layers containing okenone were deposited 11 000 years ago. Between 9000 and 7000 and since 3000 years b.p., Chromatiaceae reached a considerable biomass in the lake. Vertical changes in okenone concentration were not related to changes of paleotemperatures. In contrast, okenone concentrations decreased during periods of volcanic ash input. During most of the lake history, however, mean okenone concentrations were positively correlated with sedimentation rates. This indicates that vertical changes of okenone concentration in the sediment reflect past changes of purple sulfur bacterial biomass in the lake. According to these results, the past limnology of Mahoney Lake resembled that of the present with a sulfide-containing monimolimnion and a well-developed population of okenone-bearing purple sulfur bacteria

A two-component regulatory system for self/non-self recognition in Ustilago maydis

AbstractIn U. maydis the multiallelic b locus controls sexual and pathogenic development. In the b locus a gene coding for a regulatory protein had been identified, and it was suggested that the interaction of two b polypeptides specified by different alleles programs sexual development in this fungus. We now demonstrate the existence of a second regulatory gene in the b locus. We term this gene bW and refer to the former as the bE gene. Both genes exist in many alleles. Although unrelated in primary sequence, both genes are similar in their overall organization. The gene products display allele-specific variability in their N-terminal domains, show a high degree of sequence conservation in the C-terminal domains, and contain a homeodomain-related motif. Genetic evidence is provided to show that the pair of bE and bW polypeptides encoded by different b alleles is the key regulatory species

Impact of long-term agricultural management practices on therhizosphere microbiome and plant health

Increasing food and energy demands have resulted in a considerable intensification of farming practices, whichbrought about severe consequences for agricultural soils during last decades. In order to maintain soil quality andhealth for the future, the development of more extensive and sustainable farming strategies is urgently needed.The soil and rhizosphere microbiome play an integral role in virtually all soil processes and are intimately linkedto plant performance. Various studies indicated that agricultural management practices affect soil microbiomes.We therefore hypothesized that this external impact is conveyed by the microbial communities to the currentcrops at the time of their establishment. We used twelve differently managed soils from three long-term fieldtrials established in 1978 (Therwil, Switzerland), 1992 (Bernburg, Germany), and 2006 (Thyrow, Germany) toanalyze the impact of various management strategies (crop rotation, fertilization, tillage) on soil and its associatedrhizosphere microbiomes under consideration of plant productivity, plant health, and the ability of the soils tosuppress soil-borne phytopathogens. The model plant lettuce (Lactuca sativa L.) was cultivated for ten weeks undergrowth-chamber conditions in these soils. High-throughput sequencing of bacterial 16S rRNA genes or fungalITS fragments, respectively, PCR- amplified from total community DNA of rhizosphere and soil samples showedsignificant differences in microbial community compositions between soils that originated from the different fieldsites and long-term farming practices. Moreover, differences depending on long-term agricultural managementin plant productivity and health as measured by RT-qPCR of stress-related plant genes were observed. Localizedanalysis of rhizosphere soil solution was performed using non-invasive sampling techniques with sorption filtersplaced onto the surface of soil-grown roots along the root observation windows with subsequent HPLC-MSprofiling. Amino acids, sugars and antifungal organic acids such as benzoic acid detected in the rhizosphere soilsolutions confirmed variations in concentrations depending on the site and management practice indicating differ-ent stress potentials of farming practices for plants. Agricultural management also affected soil suppressiveness tothe soil-borne model pathogen Rhizoctonia solani.Under controlled growth chamber conditions, we could show the legacy of long-term agricultural managementpractices on the establishment and performance of a subsequent plant generation and its associated rhizospheremicrobiome

Evaluation of vardenafil for the treatment of subjective tinnitus: a controlled pilot study

<p>Abstract</p> <p>Background</p> <p>Vardenafil (Levitra^®) represents a potent and highly selective phosphodiesterase type 5 (PDE5) inhibitor, which is established for treatment of various diseases. There are several unpublished reports from patients stating that vardenafil has a considerable therapeutic effect on their concomitant tinnitus. This pilot study was conducted to specifically assess the effect of vardenafil in patients with chronic tinnitus.</p> <p>Methods</p> <p>This trial was based on a prospective, randomized, double-blind, placebo-controlled, parallel group design. Fourty-two consecutive subjects with mon- or binaural chronic tinnitus received 10 mg vardenafil (N = 21) or matching placebo tablets (N = 21) administered orally twice a day over a period of 12 weeks. Clinical examination and data acquisition took place at each visit: at baseline, after 4 weeks, after 12 weeks (end of treatment with study medication), and at non-medicated follow-up after 16 weeks. Assessment of clinical effectiveness was based on a standardized tinnitus questionnaire (TQ), the Short Form 36 health survey (SF-36), audiometric measurements (mode, pitch and loudness of tinnitus; auditory thresholds) and biomarkers of oxidative stress in patients' blood (malondialdehyde, protein carbonyl, homocysteine and total antioxidative status). Therapeutic efficacy was evaluated by comparison of subjective and objective parameters with baseline data between both treatment groups (ANCOVA).</p> <p>Results</p> <p>Vardenafil had no superior efficacy over placebo in the treatment of chronic tinnitus during this study. The primary efficacy criterion 'TQ total score' failed to demonstrate significant improvement compared to placebo. Subjective reports of TQ subscales and general quality of life areas (SF-36), objective audiometric examinations as well as investigated biomarkers for oxidative stress did not reveal any significant treatment effects. The safety profile was favorable and consistent with that in other vardenafil studies.</p> <p>Conclusion</p> <p>Although hypoxia and ischemia play a special role in the pathogenesis of tinnitus, the PDE5-inhibitor-induced increase of nitric oxide-mediated vasodilatation exerted no specific influence on tinnitus symptomatology. Considering the unclear risk of rarely associated hearing impairment, systemic application of vardenafil or other PDE5 inhibitors prove to be not appropriate for therapy of chronic tinnitus.</p

S3-Leitlinie der Deutschen Gesellschaft für Gastroenterologie, Verdauungs- und Stoffwechselkrankheiten (DGVS) zur Prophylaxe, Diagnostik und Therapie der Hepatitis-B-Virusinfektion – (AWMF-Register-Nr. 021-11)

[No abstract available