EKG und klinischer Verlauf vor und nach Implantation eines konventionellen Schrittmachers zur Evaluierung eines Kollektives mit verminderter Prognose:eine retrospektive Analyse an 298 Patienten der Schüchtermannklinik aus den Jahren 1997 bis 2000

Anhand klinischer,elektrokardiographischer und echokardiographischer Befunde untersuchten wir,welche Parameter sich auf die Prognose von Schrittmacherpatienten auswirken. Vor der Schrittmacherimplantation lag bei 75% der Patienten die QRS-Breite unter 120 msec,danach zeigten 77,2% der Patienten stimulationsbedingt eine QRS-Breite über 120 msec, bei 6,7% der Patienten war der stimulierte QRS-Komplex über 200 msec breit. Im Untersuchungszeitraum von 45 Monaten verstarben 14 von 177 nachbetreuten Patienten. In der multivariaten Analyse zeigten sich die Breite der stimulerten QRS-Komplexe über 200 ms und das präoperative NYHA-Stadium statistisch signifikant für die Ein-Jahres-Mortalität nach der Schrittmacherimplantation. Zusammenfassend kann das Ausmaß der stimulationsinduzierten QRS-Verbreiterung nach der Schrittmacherimplantation als Marker für ein erhöhtes Mortalitätsrisiko im ersten Jahr nach dem Eingriff angesehen werden

How mathematical modelling elucidates signalling in Bacillus subtilis

P>Appropriate stimulus perception, signal processing and transduction ensure optimal adaptation of bacteria to environmental challenges. In the Gram-positive model bacterium Bacillus subtilis signalling networks and molecular interactions therein are well-studied, making this species a suitable candidate for the application of mathematical modelling. Here, we review systems biology approaches, focusing on chemotaxis, sporulation, sigma B-dependent general stress response and competence. Processes like chemotaxis and Z-ring assembly depend critically on the subcellular localization of proteins. Environmental response strategies, including sporulation and competence, are characterized by phenotypic heterogeneity in isogenic cultures. The examples of mathematical modelling also include investigations that have demonstrated how operon structure and signalling dynamics are intricately interwoven to establish optimal responses. Our review illustrates that these interdisciplinary approaches offer new insights into the response of B. subtilis to environmental challenges. These case studies reveal modelling as a tool to increase the understanding of complex systems, to help formulating hypotheses and to guide the design of more directed experiments that test predictions

The Membrane Transporter OAT7 (SLC22A9) Is Not a Susceptibility Factor for Osteoporosis in Europeans

Bone production, maintenance, and modeling are a well-balanced process involving mineralization by osteoblasts and resorption by osteoclasts. Sex steroid hormones, including their conjugated forms, contribute majorly to maintaining this balance. Recently, variants in the SLC22A9 gene have been associated with osteoporosis in Korean females. We had recently shown that SLC22A9, encoding organic anion transporter 7 (OAT7), is an uptake transporter of estrone sulfate and identified several genetic variants in Europeans leading to functional consequences in vitro. We therefore hypothesized that SLC22A9 genetic variants may contribute to the pathophysiology of osteoporosis in Europeans. To test this hypothesis, we examined the associations of SLC22A9 variants with bone quality, fractures, and bone turnover markers. We genotyped SLC22A9 variants in 5,701 (2,930 female) subjects (age range, 20–93 years) extracted from the population-based Study of Health in Pomerania (SHIP and SHIP-TREND) covered by the Illumina Infinium HumanExome BeadChip version v1.0 (Exome Chip). Descriptive data (e.g., history of fractures), ultrasonography of the calcaneus, as well as serum concentrations of carboxy-terminal telopeptide of type I collagen, amino-terminal propeptide of type I procollagen, and vitamin D were determined. Comprehensive statistical analyses revealed no association between low-frequency and rare SLC22A9 variants and bone quality, fractures, and bone turnover markers. Our results indicate that single genetic SLC22A9 variants do not have a major impact on osteoporosis risk prediction in Europeans, yet findings need to be replicated in larger-scale studies

Urine Metabolomics by 1H-NMR Spectroscopy Indicates Associations between Serum 3,5-T2 Concentrations and Intermediary Metabolism in Euthyroid Humans

Context: 3,5-Diiodo-L-thyronine (3,5-T2) is a thyroid hormone metabolite which exhibited versatile effects in rodent models, including the prevention of insulin resistance or hepatic steatosis typically forced by a high-fat diet. With respect to euthyroid humans, we recently observed a putative link between serum 3,5-T2 and glucose but not lipid metabolism. Objective: The aim of the present study was to widely screen the urine metabolome for associations with serum 3,5-T2 concentrations in healthy individuals. Study Design and Methods: Urine metabolites of 715 euthyroid participants of the population-based Study of Health in Pomerania (SHIP-TREND) were analyzed by 1H-NMR spectroscopy. Multinomial logistic and multivariate linear regression models were used to detect associations between urine metabolites and serum 3,5-T2 concentrations. Results: Serum 3,5-T2 concentrations were positively associated with urinary levels of trigonelline, pyroglutamate, acetone and hippurate. In detail, the odds for intermediate or suppressed serum 3,5-T2 concentrations doubled owing to a 1-standard deviation (SD) decrease in urine trigonelline levels, or increased by 29-50% in relation to a 1-SD decrease in urine pyroglutamate, acetone and hippurate levels. Conclusion: Our findings in humans confirmed the metabolic effects of circulating 3,5-T2 on glucose and lipid metabolism, oxidative stress and enhanced drug metabolism as postulated before based on interventional pharmacological studies in rodents. Of note, 3,5-T2 exhibited a unique urinary metabolic profile distinct from previously published results for the classical thyroid hormones

Environmental Factors Affecting the Expression of pilAB as Well as the Proteome and Transcriptome of the Grass Endophyte Azoarcus sp. Strain BH72

gene encoding the structural protein of type IV pili that are essential for plant colonization appears to be regulated in a population density-dependent manner.. The expression of one of them was shown to be induced in plant roots. sp. to analyze mechanisms and molecules involved in the population-dependent gene expression in this endophyte in future

The Involvement of the McsB Arginine Kinase in Clp-Dependent Degradation of the MgsR Regulator in Bacillus subtilis

Regulated ATP-dependent proteolysis is a common feature of developmental processes and plays also a crucial role during environmental perturbations such as stress and starvation. The Bacillus subtilis MgsR regulator controls a subregulon within the stress- and stationary phase σB regulon. After ethanol exposition and a short time-window of activity, MgsR is ClpXP-dependently degraded with a half-life of approximately 6 min. Surprisingly, a protein interaction analysis with MgsR revealed an association with the McsB arginine kinase and an in vivo degradation assay confirmed a strong impact of McsB on MgsR degradation. In vitro phosphorylation experiments with arginine (R) by lysine (K) substitutions in McsB and its activator McsA unraveled all R residues, which are essentially needed for the arginine kinase reaction. Subsequently, site directed mutagenesis of the MgsR substrate was used to substitute all arginine residues with glutamate (R-E) to mimic arginine phosphorylation and to test their influence on MgsR degradation in vivo. It turned out, that especially the R33E and R94/95E residues (RRPI motif), the latter are adjacently located to the two redox-sensitive cysteines in a 3D model, have the potential to accelerate MgsR degradation. These results imply that selective arginine phosphorylation may have favorable effects for Clp dependent degradation of short-living regulatory proteins. We speculate that in addition to its kinase activity and adaptor function for the ClpC ATPase, McsB might also serve as a proteolytic adaptor for the ClpX ATPase in the degradation mechanism of MgsR

Unchaining miniBacillus PG10:Relief of FlgM-mediated repression of autolysin genes

Cell chaining in Bacillus subtilis is naturally observed in a subset of cells during exponential growth and during biofilm formation. However, the recently constructed large-scale genome-minimized B. subtilis strain PG10 displays a severe and permanent defect in cell separation, as it exclusively grows in the form of long filaments of nonseparated cells. In this study, we investigated the underlying mechanisms responsible for the incomplete cell division of PG10 by genomic and transcriptomic analyses. Repression of the SigD regulon, including the major autolysin gene lytF, was identified as the cause for the cell separation problem of PG10. It appeared that SigD-regulated genes are downregulated in PG10 due to the absence of the flagellar export apparatus, which normally is responsible for secretion of FlgM, the anti-sigma factor of SigD. Although mild negative effects on growth and cell morphology were observed, deletion of flgM could revert the aberrant cell-chaining phenotype and increased transformation efficiency. Interestingly, our work also demonstrates the occurrence of increased antisense transcription of slrR, a transcriptional repressor of autolysin genes, in PG10 and provides further understanding for this observation. In addition to revealing the molecular basis of the cell separation defect in PG10, our work provides novel targets for subsequent genome reduction efforts and future directions for further optimization of miniBacillus PG10. IMPORTANCE Reduction of the size of bacterial genomes is relevant for understanding the minimal requirements for cellular life as well as from a biotechnological point of view. Although the genome-minimized Bacillus subtilis strain PG10 displays several beneficial traits as a microbial cell factory compared to its parental strain, a defect at the final stage of cell division was introduced during the genome reduction process. By genetic and transcriptomic analyses, we identified the underlying reasons for the cell separation problem of PG10. In addition to enabling PG10 to grow in a way similar to that of B. subtilis wild-type strains, our work points toward subsequent targets for fine-tuning and further reduction of the genome of PG10. Moreover, solving the cell separation defect facilitates laboratory handling of PG10 by increasing the transformation efficiency, among other means. Overall, our work contributes to understanding and improving biotechnologically attractive minimal bacterial cell factories

Effect of Experimental Thyrotoxicosis onto Blood Coagulation: A Proteomics Study

Background: Hyperthyroidism is known to induce a hypercoagulable state. It stimulates plasma levels of procoagulative factors and reduces fibrinolytic activity. So far most of the data have been derived from patients with endogenous hyperthyroidism with a wide variability in the underlying pathogenesis and severity of the disease. Objectives: In this study we experimentally induced thyrotoxicosis in healthy volunteers to explore the effects of thyroxine excess on the plasma proteome. Using a shotgun proteomics approach, the abundance of plasma proteins was monitored before, during and after thyrotoxicosis. Methods: Sixteen healthy male subjects were sampled at baseline, 4 and 8 weeks under 250 µg/day thyroxine p.o., as well as 4 and 8 weeks after stopping the application. Plasma proteins were analyzed after depletion of 6 high-abundance proteins (MARS6) by LC-ESI-MS/MS mass spectrometry. Mass spectrometric raw data were processed using a label-free, intensity-based workflow. Subsequently, the linear dependence between protein abundances and fT4 levels were calculated using a Pearson correlation. Results: All subjects developed biochemical thyrotoxicosis, and this effect was reversed within the first 4 weeks of follow-up. None of the volunteers noticed any subjective symptoms. Levels of 10 proteins involved in the coagulation cascade specifically correlated with fT4, supporting an influence of thyroid hormone levels on blood coagulation even at nonpathological levels. Conclusions: The results suggest that experimental thyrotoxicosis exerts selective and specific thyroxine-induced effects on coagulation markers. Our study design allows assessment of thyroid hormone effects on plasma protein levels without secondary effects of other diseases or therapies

Comparison of genotyping using pooled DNA samples (allelotyping) and individual genotyping using the affymetrix genome-wide human SNP array 6.0

Background: Genome-wide association studies (GWAS) using array-based genotyping technology are widely used to identify genetic loci associated with complex diseases or other phenotypes. The costs of GWAS projects based on individual genotyping are still comparatively high and increase with the size of study populations. Genotyping using pooled DNA samples, as also being referred as to allelotyping approach, offers an alternative at affordable costs. In the