Intrazelluläre Bakterien – Freunde oder Feinde?

Legionärskrankheit aus Klimaanlagen? Augeninfektionen durch Kontaktlinsen? Bergen Protozoen und Niedere Tiere neue Krankheitserreger? Lange bevor es Tiere und Pflanzen gab, wurden die Zellen der einzelligen Lebewesen (Protozoen) von Bakterien befallen. Wir wissen somit, Infektionskrankheiten sind viel älter als die Menschheit. Und manche dieser garstigen Krankheitserreger haben sich gewissermaßen in den Menschen verirrt, da sie sonst in Protozoen, beispielsweise in Amöben, leben. Aber auch heute finden wir in jedem Tümpel, im Meer oder im Boden Protozoen und kleine Tiere, die von Mikroorganismen besiedelt werden. Den intensiven Kontakt mit solchen infizierten Kleinstlebewesen sollten wir meiden, aus ihrem Studium können wir jedoch eine Menge lernen

Candidatus Megaira polyxenophila' gen. nov., sp. nov.: Considerations on Evolutionary History, Host Range and Shift of Early Divergent Rickettsiae

“Neglected Rickettsiaceae” (i.e. those harboured by non-hematophagous eukaryotic hosts) display greater phylogenetic variability and more widespread dispersal than pathogenic ones; yet, the knowledge about their actual host range and host shift mechanism is scarce. The present work reports the characterization following the full-cycle rRNA approach (SSU rRNA sequence, specific in situ hybridization, and ultrastructure) of a novel rickettsial bacterium, herewith proposed as 'Candidatus Megaira polyxenophila' gen. nov., sp. nov. We found it in association with four different free-living ciliates (Diophrys oligothrix, Euplotes octocarinatus, Paramecium caudatum, and Spirostomum sp., all belonging to Alveolata, Ciliophora); furthermore it was recently observed as intracellular occurring in Carteria cerasiformis and Pleodorina japonica (Chlorophyceae, Chlorophyta). Phylogenetic analyses demonstrated the belonging of the candidate new genus to the family Rickettsiaceae (Alphaproteobacteria, Rickettsiales) as a sister group of the genus Rickettsia. In situ observations revealed the ability of the candidate new species to colonize either nuclear or cytoplasmic compartments, depending on the host organism. The presence of the same bacterial species within different, evolutionary distant, hosts indicates that 'Candidatus Megaira polyxenophila' recently underwent several distinct host shifts, thus suggesting the existence of horizontal transmission pathways. We consider these findings as indicative of an unexpected spread of rickettsial infections in aquatic communities, possibly by means of trophic interactions, and hence propose a new interpretation of the origin and phylogenetic diversification of rickettsial bacteria

The mitochondrial genomes of the ciliates Euplotes minuta and Euplotes crassus

Contains fulltext : 75729.pdf (publisher's version ) (Open Access)BACKGROUND: There are thousands of very diverse ciliate species from which only a handful mitochondrial genomes have been studied so far. These genomes are rather similar because the ciliates analysed (Tetrahymena spp. and Paramecium aurelia) are closely related. Here we study the mitochondrial genomes of the hypotrichous ciliates Euplotes minuta and Euplotes crassus. These ciliates are only distantly related to Tetrahymena spp. and Paramecium aurelia, but more closely related to Nyctotherus ovalis, which possesses a hydrogenosomal (mitochondrial) genome. RESULTS: The linear mitochondrial genomes of the hypotrichous ciliates Euplotes minuta and Euplotes crassus were sequenced and compared with the mitochondrial genomes of several Tetrahymena species, Paramecium aurelia and the partially sequenced mitochondrial genome of the anaerobic ciliate Nyctotherus ovalis. This study reports new features such as long 5'gene extensions of several mitochondrial genes, extremely long cox1 and cox2 open reading frames and a large repeat in the middle of the linear mitochondrial genome. The repeat separates the open reading frames into two blocks, each having a single direction of transcription, from the repeat towards the ends of the chromosome. Although the Euplotes mitochondrial gene content is almost identical to that of Paramecium and Tetrahymena, the order of the genes is completely different. In contrast, the 33273 bp (excluding the repeat region) piece of the mitochondrial genome that has been sequenced in both Euplotes species exhibits no difference in gene order. Unexpectedly, many of the mitochondrial genes of E. minuta encoding ribosomal proteins possess N-terminal extensions that are similar to mitochondrial targeting signals. CONCLUSION: The mitochondrial genomes of the hypotrichous ciliates Euplotes minuta and Euplotes crassus are rather different from the previously studied genomes. Many genes are extended in size compared to mitochondrial genes from other sources

Assessment of daily profiles of ADHD and ODD symptoms, and symptomatology related to ADHD medication, by parent and teacher ratings

DAYAS is a new two-part rating scale that assesses: (1) ADHD and ODD symptoms (externalising symptom ratings) and (2) symptomatology potentially related to ADHD medication (potentially medication-related symptoms) in real-world settings at different time periods throughout a normal school day. Data from a proof-of-concept study and two observational trials (Medikinet® retard [methylphenidate] and the Equasym XL® [methylphenidate] OBSEER study) evaluated: (1) validity of weekly externalising symptom ratings using DAYAS, in place of daily ratings; (2) reliability and internal consistency of DAYAS ratings for externalising symptoms and potentially medication-related symptoms; and (3) convergent and divergent validity of the externalising symptom ratings with existing validated scales. From the proof-of-concept study, daily scores by period of day and during the whole day correlated strongly with equivalent weekly scores (r = 0.83–0.92). Internal consistency of externalising symptom rating scales calculated from pooled data were acceptable or good by period of day (Cronbach’s alpha = 0.68–0.90) and very high for whole day scores (Cronbach’s alpha = 0.88–0.95). Internal consistency of the rating scale for potentially medication-related symptoms was also good for both teacher and parent ratings. From OBSEER data, correlations between FBB-ADHD total symptom scores and ratings on both parent and teacher versions of DAYAS were high (r = 0.73 and r = 0.84, respectively). Correlations between DAYAS and SDQ were highest for the SDQ subscales hyperactivity and conduct problems and substantially lower for pro-social behaviour, peers and emotional problems. The DAYAS rating scale had good internal consistency, and DAYAS scores correlated well with existing validated scales and the SDQ subscales hyperactivity and conduct problems. Weekly DAYAS scores (whole day and by period of day) could be considered a suitable replacement for daily assessment scores

What contributes to patient and parent satisfaction with medication in the treatment of children with ADHD? A report on the development of a new rating scale

Satisfaction with medication is important in the evaluation of overall treatment outcome. There is a lack of consistent and validated rating scales for satisfaction with medication in ADHD, therefore comparison across studies is difficult. Here, we analyse the psychometric properties of the satisfaction with medication scale (SAMS), a new item-based questionnaire that assesses satisfaction with ADHD medication. Furthermore, we evaluate the predictive effect of ADHD symptoms and quality of life (QoL) on satisfaction. Data on satisfaction with Equasym XL® (methylphenidate) were collected in the OBSEER study using the parent (SAMS-P, n = 589) and patient (SAMS-S, n = 552) versions of the SAMS questionnaire. Internal consistency, item-total and cross-informant correlations, and the stability of satisfaction ratings over time were assessed. Satisfaction with medication scores were then correlated with ratings of ADHD symptoms and QoL. Rates of overall satisfaction with Equasym XL® among parents and children were high (>70%), as was internal consistency for both SAMS-P and SAMS-S (Cronbach’s alpha > 0.9). Similarly, item-total correlations were high (r = 0.71–0.90) for SAMS-P and medium–high (r = 0.57–0.77) for SAMS-S. Cross-informant correlations and the stability of satisfaction ratings were moderate (r = 0.54–0.59 and 0.48–0.60, respectively). ADHD symptom and QoL ratings were significantly negative and positive predictors of satisfaction, explaining 36–52% of satisfaction variance at the final visit. The results show that parent and patient satisfaction was high and could be assessed reliably with the new SAMS questionnaire. Parent and patient ratings were moderately correlated, and symptom severity, functional impairment and QoL were the most significant predictors of satisfaction

An observational study of once-daily modified-release methylphenidate in ADHD: effectiveness on symptoms and impairment, and safety

ADHD affects over 5% of children worldwide. It is typically treated with stimulant medications, and methylphenidate (MPH) is the most commonly prescribed. This study investigated the effectiveness, on symptoms and impairment, and safety of Equasym XL®, a combination of 30% immediate-release and 70% modified-release MPH, in the treatment of ADHD in daily clinical practice. This open-label, observational, post-marketing surveillance study was conducted in 169 centres in Germany. Eligible patients, aged 6–17 years, were diagnosed with ADHD and about to begin treatment with Equasym XL®. Effectiveness was assessed by physicians using the clinical global impression (CGI) severity and improvement scales; teachers and parents completed questionnaires evaluating ADHD symptoms and behavioural problems (DAYAS, FBB-ADHD and SDQ-P). Assessments were carried out at baseline, after 1–3 and 6–12 weeks of treatment. Of 852 enrolled patients, 822 were evaluable; 25.30% were treatment naïve, 69.84% had previously received different MPH formulations, and 4.87% had received other medications. ADHD symptoms improved from baseline to last visit for the majority of patients for all outcome measures. According to physician ratings of core ADHD symptoms, 75.73% of patients showed improvements on the CGI-Improvement scale, 17.77% had no change, and 6.50% worsened. In teacher and parent ratings, the effectiveness of Equasym XL® was rated better than prior therapy at all measured time points across the day, particularly late morning (teachers) and early afternoon (parents). Equasym XL® was generally well tolerated; only 3.16% of patients permanently discontinued treatment due to adverse events. Equasym XL® is effective and well tolerated in daily clinical practice

Development and optimization of receptor fusion proteins for the inhibition of IL-6-type cytokines in vivo

Cytokines are small soluble proteins with regulatory functions in many biological processes including immune responses. Dysregulated cytokine signaling is often responsible for the development and maintenance of acute and chronic inflamma-tion. Current anti-cytokine therapies have substantially improved the treatment of inflammatory diseases. Cytokine-targeting drugs are usually biologics such as neutralizing antibodies or soluble receptors. To target cytokines that signal through heteromeric receptor complexes we developed a strategy that involves the inline fusion of the ligand binding domains of the corresponding receptor subunits. These receptor fusion proteins (RFPs) are highly potent and specific, monogenic by design, and therefore well suited for gene transfer approaches.The first part of this project deals with the development of a novel RFP targeting murine interleukin-31 (IL-31). IL-31, mostly involved in skin diseases, signals through heterodimeric receptor complexes comprised of the interleukin-31 receptor (IL-31R) and the oncostatin M receptor (OSMR) subunits. Inline fusion of domains D1-D4 of murine OSMR and domains D1-D2 of murine IL-31R connected by a flexible linker results in a potent inhibitor for murine IL-31 (mIL-31-RFP). To assess the inhibitory potential of mIL-31-RFP we established and characterized a cell-based system for the analysis of murine IL-31 and oncostatin M (OSM) signaling. mIL-31-RFP specifically inhibits IL-31-dependent signal-transduction and does not interfere with the activity of mOSM. In the second part of this project, we investigated, as a proof-of-principle for other monogenic RFPs, the potential of the previously described mIL-6-RFP to inhibit interleukin-6 (IL-6) in vivo. Therefore, transgenic mice that express mIL-6-RFP in an inducible and tissue-specific manner were generated and characterized. In a parallel approach, we re-engineered mIL-6-RFP by fusion to the Fc of mIgG2a (mIL-6-RFP-Fc) for enhanced inhibitory activity and improved protein expression by codon optimization. Upon application in mice, recombinant mIL-6-RFP-Fc inhibited IL-6-induced activation of the transcription factor STAT3 and ERK1/2 kinases in liver and kidney. Gene transfer through hydrodynamic plasmid delivery in mice resulted in hepatic production and secretion of mIL-6-RFP-Fc into the blood in considerable amounts, blocked hepatic acute-phase protein synthesis and improved kidney function in a renal ischemia and reperfusion injury model. The strategy described here is applicable for many cytokines involved in inflammatory and other diseases

Development and optimization of receptor fusion proteins for the inhibition of IL-6-type cytokines in vivo

Cytokines are small soluble proteins with regulatory functions in many biological processes including immune responses. Dysregulated cytokine signaling is often responsible for the development and maintenance of acute and chronic inflamma-tion. Current anti-cytokine therapies have substantially improved the treatment of inflammatory diseases. Cytokine-targeting drugs are usually biologics such as neutralizing antibodies or soluble receptors. To target cytokines that signal through heteromeric receptor complexes we developed a strategy that involves the inline fusion of the ligand binding domains of the corresponding receptor subunits. These receptor fusion proteins (RFPs) are highly potent and specific, monogenic by design, and therefore well suited for gene transfer approaches.The first part of this project deals with the development of a novel RFP targeting murine interleukin-31 (IL-31). IL-31, mostly involved in skin diseases, signals through heterodimeric receptor complexes comprised of the interleukin-31 receptor (IL-31R) and the oncostatin M receptor (OSMR) subunits. Inline fusion of domains D1-D4 of murine OSMR and domains D1-D2 of murine IL-31R connected by a flexible linker results in a potent inhibitor for murine IL-31 (mIL-31-RFP). To assess the inhibitory potential of mIL-31-RFP we established and characterized a cell-based system for the analysis of murine IL-31 and oncostatin M (OSM) signaling. mIL-31-RFP specifically inhibits IL-31-dependent signal-transduction and does not interfere with the activity of mOSM. In the second part of this project, we investigated, as a proof-of-principle for other monogenic RFPs, the potential of the previously described mIL-6-RFP to inhibit interleukin-6 (IL-6) in vivo. Therefore, transgenic mice that express mIL-6-RFP in an inducible and tissue-specific manner were generated and characterized. In a parallel approach, we re-engineered mIL-6-RFP by fusion to the Fc of mIgG2a (mIL-6-RFP-Fc) for enhanced inhibitory activity and improved protein expression by codon optimization. Upon application in mice, recombinant mIL-6-RFP-Fc inhibited IL-6-induced activation of the transcription factor STAT3 and ERK1/2 kinases in liver and kidney. Gene transfer through hydrodynamic plasmid delivery in mice resulted in hepatic production and secretion of mIL-6-RFP-Fc into the blood in considerable amounts, blocked hepatic acute-phase protein synthesis and improved kidney function in a renal ischemia and reperfusion injury model. The strategy described here is applicable for many cytokines involved in inflammatory and other diseases