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ZusammenfassungDer Aufsatz bietet den ersten konsistenten Überblick über den Wandel der politischen Positionen der protestantischen Theologie in der DDR. Mit Hilfe von Anregungen aus der Cambridge School der Ideengeschichte geht der Text der Frage nach, inwieweit die ostdeutsche evangelische Theologie Resistenzpotential gegenüber dem politischen Anpassungsdruck des SED-Regimes aufzubringen vermochte. Dabei widersprechen die Autoren der in der Forschung verbreiteten Auffassung, die Protestanten hätten die Theologie in obrigkeitstreuer Tradition einmal mehr den neuen Verhältnissen angepasst. Vielmehr lässt sich ein deutlicher Bruch nach 1945 erkennen, eine jahrelang anhaltende Kritik an der atheistischen Regierung und ein theologisches Ringen um ein angemessenes Obrigkeitsverständnis. Erst äußere Anlässe brachten die Kirchen dazu, ihre fundamentalkritische Theologie Zug um Zug aufzugeben. Dazu gehört die Zementierung der deutschen Teilung, die den Rückhalt der ostdeutschen Kirchen in der gesamtdeutschen EKD schwächte, oder auch die Ungleichheit in der Verteilung der Machtmittel, die die Kirchen an den Staat auslieferten. Neben diesen strukturellen Gründen benennen die Autoren ideelle Motive wie die Kritik an der Institution EKD, durch die sich die jüngeren Theologen von der älteren Generation ablösen wollten. Einflussreich waren auch internationale ökumenische Diskurse, die seit den siebziger Jahren den Kapitalismus zunehmend kritisch und den Sozialismus entsprechend positiv einordneten. Obwohl die wenigen verbliebenen Christen sich immer wieder unangepasst verhielten, ließ sich die Theologie insgesamt mehr und mehr zur Rechtfertigung des Anpassungsweges einspannen. Nicht sie bestimmte die politische Haltung. Vielmehr gaben äußere Faktoren die theologischen Positionsbestimmungen der Kirche vor.
In order to identify possible experimental signatures of the superfluid to Mott-insulator quantum phase transition we calculate the charge structure factor S(k, ω) for the one-dimensional Bose-Hubbard model using the dynamical density-matrix renormalisation group (DDMRG) technique. Particularly we analyse the behaviour of S(k, ω) by varying – at zero temperature–the Coulomb interaction strength within the first Mott lobe. For strong interactions, in the Mott-insulator phase, we demonstrate that the DDMRG results are well reproduced by a strong-coupling expansion, just as the quasi-particle dispersion. In the super-fluid phase we determine the linear excitation spectrum near k = 0. In one dimension, the amplitude mode is absent which mean-field theory suggests for higher dimensions.
Abstract
We present experiments on the luminescence of excitons confined in a potential trap at milli-Kelvin bath temperatures under continuous-wave (cw) excitation. They reveal several distinct features like a kink in the dependence of the total integrated luminescence intensity on excitation laser power and a bimodal distribution of the spatially resolved luminescence. Furthermore, we discuss the present state of the theoretical description of Bose–Einstein condensation of excitons with respect to signatures of a condensate in the luminescence. The comparison of the experimental data with theoretical results with respect to the spatially resolved as well as the integrated luminescence intensity shows the necessity of taking into account a Bose–Einstein condensed excitonic phase in order to understand the behaviour of the trapped excitons.
Abstract
In the 21st century, most of the world’s glaciers are expected to retreat due to further global warming. The range of this predicted retreat varies widely as a result of uncertainties in climate and glacier models. To calibrate and validate glacier models, past records of glacier mass balance are necessary, which often only span several decades. Long-term reconstructions of glacier mass balance could increase the precision of glacier models by providing the required calibration data. Here we show the possibility of applying shrub growth increments as an on-site proxy for glacier summer mass balance, exemplified by Salix shrubs in Finse, Norway. We further discuss the challenges which this method needs to meet and address the high potential of shrub growth increments for reconstructing glacier summer mass balance in remote areas.
Patients with atrial fibrillation (AF) often present with typical angina pectoris and mildly elevated levels of cardiac troponin (non-ST-segment elevation myocardial infarction) during an acute episode of AF. However, in a large proportion of these patients, significant coronary artery disease is excluded by coronary angiography, which suggests that AF itself influences myocardial blood flow. The present review summarizes the effect of AF on the occurrence of ventricular oxidative stress, redox-sensitive signaling pathways and gene expression, and microcirculatory flow abnormalities in the left ventricle.
Heart Rate Reduction by Ivabradine Improves Aortic Compliance in Apolipoprotein E-Deficient Mice
(2012)
Background: Impaired vascular compliance is associated with cardiovascular mortality. The effects of heart rate on vascular compliance are unclear. Therefore, we characterized effects of heart rate reduction (HRR) by I(f) current inhibition on aortic compliance and underlying molecular mechanisms in apolipoprotein E-deficient (ApoE<sup>–</sup>/<sup>–</sup>) mice. Methods: ApoE<sup>–</sup>/<sup>–</sup> mice fed a high-cholesterol diet and wild-type (WT) mice were treated with ivabradine (20 mg/kg/d) or vehicle for 6 weeks. Compliance of the ascending aorta was evaluated by MRI. Results: Ivabradine reduced heart rate by 113 ± 31 bpm (∼19%) in WT mice and by 133 ± 6 bpm (∼23%) in ApoE<sup>–</sup>/<sup>–</sup> mice. Compared to WT controls, ApoE<sup>–</sup>/<sup>–</sup> mice exhibited reduced distensibility and circumferential strain. HRR by ivabradine increased distensibility and circumferential strain in ApoE<sup>–</sup>/<sup>–</sup> mice but did not affect both parameters in WT mice. Ivabradine reduced aortic protein and mRNA expression of the angiotensin II type 1 (AT1) receptor and reduced rac1-GTPase activity in ApoE<sup>–</sup>/<sup>–</sup> mice. Moreover, membrane translocation of p47<sup>phox</sup> was inhibited. In ApoE<sup>–</sup>/<sup>–</sup> mice, HRR induced anti-inflammatory effects by reduction of aortic mRNA expression of IL-6, TNF-alpha and TGF-beta. Conclusion: HRR by ivabradine improves vascular compliance in ApoE<sup>–</sup>/<sup>–</sup> mice. Contributing mechanisms include downregulation of the AT1 receptor, attenuation of oxidative stress and modulation of inflammatory cytokine expression.
The human brain is distinguished by its remarkable size, high energy consumption, and cognitive abilities compared to all other mammals and non-human primates. However, little is known about what has accelerated brain evolution in the human lineage. One possible explanation is that the appearance of advanced communication skills and language has been a driving force of human brain development. The phenotypic adaptations in brain structure and function which occurred on the way to modern humans may be associated with specific molecular signatures in today’s human genome and/or transcriptome. Genes that have been linked to language, reading, and/or autism spectrum disorders are prime candidates when searching for genes for human-specific communication abilities. The database and genome-wide expression analyses we present here revealed a clustering of such communication-associated genes (COAG) on human chromosomes X and 7, in particular chromosome 7q31-q36. Compared to the rest of the genome, we found a high number of COAG to be differentially expressed in the cortices of humans and non-human primates (chimpanzee, baboon, and/or marmoset). The role of X-linked genes for the development of human-specific cognitive abilities is well known. We now propose that chromosome 7q31-q36 also represents a hot spot for the evolution of human-specific communication abilities. Selective pressure on the T cell receptor beta locus on chromosome 7q34, which plays a pivotal role in the immune system, could have led to rapid dissemination of positive gene variants in hitchhiking COAG.
The autism susceptibility locus on human chromosome 7q32 contains the maternally imprinted MEST and the non-imprinted COPG2 and TSGA14 genes. Autism is a disorder of the ‘social brain’ that has been proposed to be due to an overbalance of paternally expressed genes. To study regulation of the 7q32 locus during anthropoid primate evolution, we analyzed the methylation and expression patterns of MEST, COPG2, and TSGA14 in human, chimpanzee, Old World monkey (baboon and rhesus macaque), and New World monkey (marmoset) cortices. In all human and anthropoid primate cortices, the MEST promoter was hemimethylated, as expected for a differentially methylated imprinting control region, whereas the COPG2 and TSGA14 promoters were completely demethylated, typical for transcriptionally active non-imprinted genes. The MEST gene also showed comparable mRNA expression levels in all analyzed species. In contrast, COPG2 expression was downregulated in the human cortex compared to chimpanzee, Old and New World monkeys. TSGA14 either showed no differential regulation in the human brain compared to chimpanzee and marmoset or a slight upregulation compared to baboon. The human-specific downregulation supports a role for COPG2 in the development of a ‘social brain’. Promoter methylation patterns appear to be more stable during evolution than gene expression patterns, suggesting that other mechanisms may be more important for inter-primate differences in gene expression.
Tetrasomy 9p is a rare chromosomal syndrome and about 30% of known cases exhibit mosaicism. Approximately 50 of the reported cases with tetrasomy 9p mosaicism show a characteristic facial appearance, growth failure, and developmental delay. However, 3 patients with mosaicism for isochromosome 9p and a normal phenotype have also been reported. We report 2 additional cases of clinically normal young females with tetrasomy 9p mosaicism, one of whom also exhibited X chromosome aneuploidy mosaicism leading to an overall of 6 different cell lines. STR analysis performed on this complex mosaic case indicated that the extra isochromosome was of maternal origin while the X chromosome aneuploidy was of paternal origin, indicating a postzygotic event.
The aim of this study was to analyse the predictive power of several clinical baseline parameters and the de-/remineralisation properties of in vivo etched sites measured with quantitative light-induced fluorescence (QLF) for subsequent 2-year caries increment. At baseline, in 44 children (8.23 ± 1.5 years) two areas (diameter 2 mm) of the buccal surface of a primary posterior tooth were etched with 36% phosphoric acid gel for 1 and 4 min, respectively. The etched sites were analysed immediately after etching (ΔQ1) and 24 h (ΔQ2) later by QLF. Additionally, caries status (deft/DMFT and initial caries), approximal plaque, bleeding on probing, and the patient’s current use of fluorides were recorded. In the 2-year follow-up, 29 children were re-assessed. After clinical examination, the caries increment was calculated (ΔDMFT) and correlated with the baseline clinical variables and the QLF readings. Results showed a significant positive correlation between ΔQ<sub>1 min</sub> and the ΔDMFT (r = 0.44, p = 0.02). The ΔDMFT was significantly correlated with the baseline deft (r = 0.56, p = 0.002), cavitated active caries lesions (r = 0.52, p = 0.003), and filled teeth (r = 0.53, p = 0.003). In a regression analysis the use of fluoridated salt (SC = –0.10) and fluoride gel (SC = –0.14) were negatively associated with ΔDMFT. In conclusion, these findings suggest that the demineralisation properties of the etched sites and the outcome of the 24-hour measurements with QLF are significantly associated with caries increment. Previous caries experience strongly correlated with caries increment in this group of children.
Effectiveness of Varenicline as an Aid to Smoking Cessation in Primary Care: An Observational Study
(2012)
Aims: Although varenicline is commonly prescribed in primary care, information on smoking-related comorbidities and the effectiveness of varenicline in this context in Germany is scarce. This study assessed the efficacy and safety of varenicline in a large sample of patients seeking smoking cessation treatment through their general practitioners. The frequency of comorbidities was also evaluated. Methods: This was a 12-week, prospective, observational, non-comparative phase IV trial conducted in Germany. Abstinence rates at week 12 were evaluated by verbal reporting using the nicotine use inventory. Results: Overall, 1,391 subjects were enrolled; 1,177 received study medication and were evaluated for effectiveness and safety. At the end of the study, 71.1% (95% confidence interval 68.5–73.7) of subjects were abstinent. There were a total of 205 all-causality adverse events; 2.2% were classified as serious or severe. There were no fatal adverse events. At inclusion, 66.7% of participants had at least 1 concurrent comorbidity, with chronic obstructive pulmonary disease (35.5%), hypertension (29.6%) and depression (10.4%) being the most commonly reported. Conclusion: These real-world data indicate that varenicline is an effective and well-tolerated smoking cessation treatment when used in the primary care setting including patients with smoking-related comorbidities.
Background: In postoperative sepsis, mortality is increased due to the surgically induced immune dysfunction. Further causes of this traumatic effect on the immune system include burn injuries and polytrauma, as well as endogenous traumata like stroke. Several animal models have been defined to analyse the characteristics of trauma-induced immune suppression. This article will correlate our results from animal studies and clinical observations with the recent literature on postoperative immune suppression. Methods: The previously described model of surgically induced immune dysfunction (SID) was performed in mice by laparotomy and manipulation of the small intestine in the antegrade direction. Blood samples were collected 6 and 72 h following SID to analyse the white blood cell count and corticosterone levels. To assess the postoperative immune status in humans, we analysed expression of HLA-DR on monocytes of 118 patients by flow cytometry prior to and 24, 48 and 72 h after surgery. Results: The postoperative immune suppression in our SID model is characterised by lymphocytopenia and significantly increased corticosterone levels in mice dependent on the degree of surgical trauma. This is comparable to the postoperative situation in humans: major and especially long-lasting surgery results in a significantly reduced expression of HLA-DR on circulating monocytes. Previous studies describe a similar situation following burn injury and endogenous trauma, i.e. stroke. Conclusions: We suggest the completion of our previously published sepsis classification due to the immune status at the onset of sepsis: type A as the spontaneously acquired sepsis and type B as sepsis in trauma-induced pre-existing immune suppression.
Background/Aims: Only rather few data on the validity of screening questionnaires to detect problem drinking in adolescents exist. The aim of this study was to compare the performance of the Alcohol Use Disorders Identification Test (AUDIT), its short form AUDIT-C, the Substance Module of the Problem Oriented Screening Instrument for Teenagers (POSIT), and CRAFFT (acronym for car, relax, alone, forget, family, and friends). Methods: The questionnaires were filled in by 9th and 10th graders from two comprehensive schools. All students received an interview using the alcohol section of the Composite International Diagnostic Interview. Alcohol abuse and alcohol dependence according to DSM-IV as well as episodic heavy drinking served as criteria to validate the screening instruments. Results: All 9th and 10th graders (n = 225) of both schools participated. No significant differences were found for areas under the receiver operating characteristic curves ranging from 0.810 to 0.872. Cronbach’s alpha was satisfactory (0.77–0.80) but poor for CRAFFT (0.64). Different cut-offs are discussed. Conclusions: Considering validity as well as reliability, AUDIT, AUDIT-C and POSIT performed well; however, the POSIT is quite lengthy. AUDIT-C showed good psychometric properties and has clear advantages because of its brevity.
Background: Among the five somatostatin receptors (sst<sub>1</sub>-sst<sub>5</sub>), the sst<sub>3</sub> receptor displays a distinct pharmacological profile. Like sst<sub>2</sub>, the sst<sub>3</sub> receptor efficiently internalizes radiolabeled somatostatin analogs. Unlike sst<sub>2</sub>, however, internalized sst<sub>3</sub> receptors are rapidly transferred to lysosomes for degradation. Apart from this, very little is known about the clinical relevance of the sst<sub>3</sub> receptor, which may in part be due to the lack of specific monoclonal sst<sub>3</sub> antibodies. Methods: Here, we have extensively characterized the novel rabbit monoclonal anti-human sst<sub>3</sub> antibody UMB-5 using transfected cells and receptor-expressing tissues. UMB-5 was then subjected to immunohistochemical staining of a series of 190 formalin-fixed, paraffin-embedded normal and neoplastic human tissues. Results: Specificity of UMB-5 was demonstrated by detection of a broad band migrating at a molecular weight of 70,000–85,000 in immunoblots from human pituitary. After enzymatic deglycosylation, the size of this band decreased to a molecular weight of 45,000. Tissue immunostaining was completely abolished by pre-adsorption of UMB-5 with its immunizing peptide. In addition, UMB-5 detected distinct cell populations in human tissues like pancreatic islands, anterior pituitary, adrenal cortex, adrenal medulla, and enteric ganglia, similar to that seen with a rabbit polyclonal antibody generated against a different carboxyl-terminal epitope of the sst<sub>3</sub> receptor. In a comparative immunohistochemical study, UMB-5 yielded predominant plasma membrane staining in the majority of pituitary adenomas, pheochromocytomas, and a subset of neuroendocrine tumors. The sst<sub>3</sub> receptor was also present in many glioblastomas, pancreatic, breast, cervix, and ovarian carcinomas. Conclusion: The rabbit monoclonal antibody UMB-5 may prove of great value in the identification of sst<sub>3</sub>-expressing tumors during routine histopathological examinations. Given its unique trafficking properties, these tumors may be potential candidates for sst<sub>3</sub>-directed receptor radiotherapy.
Background: To analyze the relation and distribution of mean, systolic and diastolic ocular perfusion pressure (OPP) in telemedical homemonitoring of patients with primary open-angle glaucoma (POAG). Methods: 70 patients with POAG measured intraocular pressure (IOP) and blood pressure at home for a period of 6 months with the Goldmann applanation self-tonometer Ocuton S and the blood pressure device boso medicus PC. Twenty-four-hour profiles were taken every 4 weeks in addition to single measurements in the morning and evening once a week. All measured values were transmitted to an electronic patient record, which calculated OPP by taking systolic, diastolic and mean arterial blood pressure and subtracting IOP. Results: We analyzed 3,282 values of mean, systolic and diastolic OPP. The quantity of values below the risk levels of the Barbados Eye Studies was calculated. We found values lower than the risk levels for LE: 49 (1.5%)/RE: 60 (1.8%) systolic OPP, LE: 1,623 (49.5%)/RE: 1,761 (53.7%) diastolic OPP and LE: 687 (20.9%)/RE: 794 (24.2%) mean OPP. The individual average OPP levels of all 70 patients below the risk levels showed the following distribution: LE: 4 (5.7%)/RE: 6 (8.6%) systolic OPP, LE: 19 (27.1%)/RE: 20 (28.6%) diastolic OPP and LE: 10 (14.3%)/RE: 10 (14.3%) mean OPP. Conclusion: The individual distribution of different OPP values in POAG patients is not easy to interpret for clinical ophthalmologists. Precise practicable guidelines for clinical use still have to be determined.
Background: Alveolar soft-part sarcoma (ASPS) is a rare sarcoma often occurring in young patients that is characterized by the unbalanced translocation der(17)t(X;17) (p11;q25). Although itusuallyshowsan indolent clinical course, the prognosis is usually poor in advanced disease. Since standard chemotherapy regimens used in soft-tissue sarcomas lack efficacy in ASPS, new therapeutic options are needed. We investigated the efficacy of trabectedin, which has demonstrated activity in a variety of cancer types including some of the most prevalent translocation-related sarcomas. Patients and Methods: 7 patients with metastatic or advanced ASPS treated with trabectedin in the Sarcoma Center Berlin-Brandenburg and the University Hospital of Greifswald were analyzed for median progression-free survival (mPFS), overall survival (OS), and therapy-related toxicity. Results: In 6 patients with documented disease progression, disease stabilization was reached with trabectedin; only 1 patient experienced progressive disease. The mPFS and OS were 7 months and 21 months, respectively, since the start of trabectedin treatment. Overall, no severe Common Toxicity Criteria (CTC) grade 3 or 4 toxicity was observed. Conclusions: The poor prognosis of patients with ASPS has so far been due to the unavailability of effective systemic treatments. Trabectedin can be considered the only currently registered drug with clinical activity in this disease.
Background: There is evidence that the borderline symptomatology of the mother longitudinally predicts the number of borderline criteria met by the children. However, possible underlying mechanisms have rarely been examined. In line with transactional models of borderline personality disorder (BPD), we analyzed a broad concept of maladaptive mother-child interactions of mothers with BPD symptoms towards their children, including insensitive parenting and mother-child discrepancies, in reporting the child's psychopathological behavior. Sampling/Methods: The sample was drawn from the population-based Greifswald Family Study and consisted of 295 children and their biological mothers. Both were examined at two points in time, first when the children were about 15 years old (T₀) and again 5 years later (T<sub>1</sub>), using path analyses. Results: Maladaptive mother-child interactions (especially an overprotective and rejecting parenting style and high discrepancies regarding internalizing problems) mediate the longitudinal transmission of borderline symptoms from mother to child. Furthermore, our data revealed that this result is consistent for various youth symptoms which are associated with BPD such as impulsivity or dissociation. Conclusion: The data of the current study imply that the transmission of borderline symptoms from mother to child is mediated by maladaptive mother-child interactions. For this reason early and professional support may be useful to prevent these children from developing severe psychopathology.
Background: Controversy surrounds the questions whether co-occurring depression has negative effects on cognitivebehavioral therapy (CBT) outcomes in patients with panic disorder (PD) and agoraphobia (AG) and whether treatment for PD and AG (PD/AG) also reduces depressive symptomatology. Methods: Post-hoc analyses of randomized clinical trial data of 369 outpatients with primary PD/AG (DSM-IV-TR criteria) treated with a 12-session manualized CBT (n = 301) and a waitlist control group (n = 68). Patients with comorbid depression (DSM-IV-TR major depression, dysthymia, or both: 43.2% CBT, 42.7% controls) were compared to patients without depression regarding anxiety and depression outcomes (Clinical Global Impression Scale [CGI], Hamilton Anxiety Rating Scale [HAM-A], number of panic attacks, Mobility Inventory [MI], Panic and Agoraphobia Scale, Beck Depression Inventory) at post-treatment and follow-up (categorical). Further, the role of severity of depressive symptoms on anxiety/depression outcome measures was examined (dimensional). Results: Comorbid depression did not have a significant overall effect on anxiety outcomes at post-treatment and follow-up, except for slightly diminished post-treatment effect sizes for clinician-rated CGI (p = 0.03) and HAM-A (p = 0.008) when adjusting for baseline anxiety severity. In the dimensional model, higher baseline depression scores were associated with lower effect sizes at post-treatment (except for MI), but not at follow-up (except for HAM-A). Depressive symptoms improved irrespective of the presence of depression. Conclusions: Exposure-based CBT for primary PD/AG effectively reduces anxiety and depressive symptoms, irrespective of comorbid depression or depressive symptomatology.
Colonization and infection of wounds represent a major reason for the impairment of tissue repair. Recently, it has been reported that tissue-tolerable plasma (TTP) is highly efficient in the reduction of the bacterial load of the skin. In the present study, the antiseptic efficacy of TTP was compared to that of octenidine hydrochloride with 2-phenoxyethanol. Both antiseptic methods proved to be highly efficient. Cutaneous treatment of the skin with octenidine hydrochloride and 2-phenoxyethanol leads to a 99% elimination of the bacteria, and 74% elimination is achieved by TTP treatment. Technical challenges with an early prototype TTP device could be held responsible for the slightly reduced antiseptic properties of TTP, compared to a standard antiseptic solution, since the manual treatment of the skin surface with a small beam of the TTP device might have led to an incomplete coverage of the treated area.
Background: To determine the suitability of different superimposed high-frequency jet ventilation (SHFJV) application methods during tracheal bleeding. Objective: To determine the effect of SHFJV on the aspiration of blood during tracheal bleeding. Methods: A test lung was ventilated using SHFJV via a rigid endoscope, a jet laryngoscope and a 4-lumen jet catheter. Packed red blood cells (PRBCs) were injected into the artificial trachea caudally to the rigid endoscope and jet laryngoscope ventilation, and both caudally and cranially during ventilation via the 4-lumen jet catheter, and the migration of PRBCs during ventilation was studied using continuous video recording. Results: Migration of blood into the lower respiratory tract did not occur during SHFJV via the rigid endoscope and jet laryngoscope and via the 4-lumen jet catheter with the bleeding caudal to ventilation source. If the bleeding was cranial to the 4-lumen jet catheter ventilation, migration of blood into the lower respiratory tract was seen when reflux of blood reached the entrainment area. From this area, blood is transported within the jet stream into the lower respiratory tract. Conclusions: SHFJV protects the lower respiratory tract from blood aspiration in case of tracheal bleeding. During SHFJV via the 4-lumen jet catheter, aspiration of blood only occurs if bleeding is localized cranial to the 4-lumen jet catheter ventilation. In case of heavy tracheal bleeding, the jet sources should be positioned cranial to the site of bleeding.
Background: In clinical practice, treatment of genital tract infections is based on administration of either antibiotics or antiseptics. While antibiotics may be applied systemically or topically, antiseptics may be applied only topically. In case of bacterial vaginosis (BV), antibiotic therapy may often be limited and side effects due to systemic administration may develop. Polihexanide (PHMB) is a promising option for the topical treatment of genital tract infections, in particular BV and vaginitis. Method: A systematic search for publications on the use of PHMB for the treatment of genital infections in two electronic databases was performed. Titles, abstracts and citations were imported into a reference database. Duplicates were removed and two reviewers assessed each identified publication separately. Results: Among a total of 204 references, 3 prospective randomized trials were identified. Two trials treated BV infections with PHMB in comparison to clindamycin as antibiotic standard therapy with no significant differences either in safety or in efficacy. The third controlled trial investigated the clinical efficacy of PHMB compared to placebo in the treatment of human papilloma virus. Patients treated with PHMB daily for up to 16-weeks showed significantly higher (52%) clearance of genital warts as compared to patients treated with placebo (4%). Conclusion: PHMB may be a clinically effective alternative for the treatment of BV and human papilloma virus. Although PHMB-based antiseptics are available since the late 90s, controlled trials to investigate its clinical potential for antiseptic treatment are scant. Clinical use of antiseptics for the treatment of infectious diseases should be explored and supported further.
Despite a plethora of therapeutic approaches, the injection of local anaesthetics itself remains one of the most painful and dreadful procedures among children. Stimulation of acupoint LI4 is associated with analgesic effects in dentistry. Goal of the study To investigate whether stimulation of LI4, added to standard therapy (ST), reduces pain and distress during injection of local anaesthetic (LA) in comparison with ST alone. Materials and Methods Children, scheduled for dental treatment in local anaesthesia on 2 separate days were enrolled in this trial, approved by local ethics commission. On one day each child received bilateral acupuncture of LI4 point, using indwelling fixed “New Pyonex” needles (0.2 x 1.5 mm; Seirin, Japan). The parents of the children were asked to stimulate the needles by massage. Standardized injection of LA was performed 5 min following acupuncture. The needles were withdrawn at the end of dental treatment. On the other day of treatment children received LA injection without acupuncture. The order of treatment days (acupuncture first or vice versa) was randomised. Primary endpoint was the pain intensity during LA injection reported by children on Visual Rating Scale from 0=no pain to 10=maximal pain imaginable (VRS-11). Secondary endpoints were parent- and dentist-assessed pain intensity (measured on Numeric Rating Scale 1-10), patients’ heart rate before and during dental treatment and satisfaction with received therapy (measured on Numerical Rating Scale 1-5.) Side effects of LI4 stimulation were also recorded. Results and Discussion The data of 49 children (22 females; age 10 ± 4 yrs; mean ± SD), who completed both visits, were analysed. Children reported less pain with than without acupuncture: 2.2 ± 2.5 vs. 3.9 ± 2.7; mean ± SD, p<0.001. Heart rate decreased after LI4 stimulation compared to ST alone throughout the dental treatment (p<0.05). LI4 stimulation was safe and raised better satisfaction with the treatment among children and parents, than ST alone (p<0.05). Other secondary endpoints were comparable between both sessions. Conclusion Stimulation of acupuncture point LI4 reduces pain and autonomous stress during injection of local anaesthetics in paediatric dentistry.
Primary Pan-CT is associated with improved clinical course and outcome in polytrauma patients
(2012)
The early clinical management of patients with polytrauma remains challenging. Clinical examination is unreliable in identifying the presence and severity of injuries, and diagnostic imaging plays a central role in the evaluation of the injury pattern. In the last decade, whole body multi slice computed tomography (Pan-CT) performed immediately after admission gained recognition in Europe and United States. Its utility and value, given the lack of accuracy data and concerns about unnecessary exposure to radiation, is undefined. The primary objective of this retrospective cohort study was to compare survival of multiple trauma (polytrauma) patients (Injury Severity Score [ISS] ≥ 16) prior to (1999 - 2002) and after (2002 - 2004) the introduction of a Pan-CT-based trauma resuscitation algorithm at a maximum care university medical centre. Secondary objectives were to compare the complication rates and duration of intensive care treatment. The study included 123 patients (mean age 34.6 years [SD 16.8], mean ISS 26.7 [SD 8.7]) in the control and 104 (mean age 39.8 years [SD 20.0], mean ISS 28.6 [SD 10.5]) patients in the intervention period. Die Baseline criteria were well balanced amongst both cohorts except for age (34.6 versus 39.8 years, p = 0.034). Both cohorts had a similar predicted probability of survival using the TRISS method (77.5 versus 77.6%, p = 0.979). Raw mortality decreased markedly but not statistically significantly in Pan-CT cohort (17.9 versus 11.5%, risk ratio (RR) 0.65, 95% confidence interval (CI) 0.34 - 1.24). However, after adjustment for injury severity, by mortality odds ratio of 0.40 (95% CI 0.17 – 0.95, p = 0.038) Pan-CT patients were 2.5 times more likely to survive. The mean difference in the duration of ICU treatment (5.1, 95% CI 1.2 – 9.0 days), days on respirator (5.3, 95% CI 2.0 - 8.6), and number of complications (0.4, 95% CI 0.2 – 0.8) was statistically significant and in favour of the Pan-CT-period.
The learning theory of panic disorder differs between panic attacks and anxious apprehension as distinct emotional states. Acute panic is accompanied by extreme fear, experience of strong body symptoms reflecting autonomic surge and flight tendencies. In contrast, anxious apprehension is associated with hypervigilance towards bodily sensations and increased distress when subtle somatic symptoms are identified. Following animal models, these clinical entities reflect different stages of defensive reactivity depending upon the imminence of interoceptive or exteroceptive threat cues with lowest distance to threat during panic attacks. We tested this model by investigating the dynamics of defensive reactivity in a large group of patients suffering from panic disorder and agoraphobia (PD/AG) prior to a multicenter controlled clinical trial. Three hundred forty-five patients participated in a standardized behavioral avoidance test (being entrapped in a small, dark chamber for 10 minutes). Defensive reactivity was assessed measuring avoidance and escape behavior, self reports of anxiety and panic symptoms, autonomic arousal (heart rate and skin conductance), and potentiation of the startle reflex before and during the exposure period of the behavioral avoidance test. While 125 patients showed strong anxious apprehension during the task (as indexed by increased reports of anxiety, elevated physiological arousal, and startle potentiation), 72 patients escaped from the test chamber. Active escape was initiated at the peak of the autonomic surge accompanied by an inhibition of the startle response as predicted by the animal model. These physiological responses were observed during 34 reported panic attacks as well. We found evidence that defensive reactivity in PD/AG patients is dynamically organized ranging from anxious apprehension to panic with increasing proximity of interoceptive threat. Importantly, the patients differed quite substantially according defensive reactivity during the behavioral avoidance test despite all patients received the same principal diagnosis. These differences can be explained in part by differences in the disposition according to two genetic variants previously associated with panic disorder. Patients carrying the risk variant of a polymorphism in the neuropeptide S receptor gene showed an overall increased heart rate during the whole behavioral avoidance test reflecting an enhanced sympathomimetic activation and consequently arousal level. During the entrapment situation in which heart rate further increased over an already elevated baseline level, risk variant carriers were prone to experience more panic symptoms. This is in line with the learning perspective of panic disorder, postulating that internal cues of elevated arousal increase the chance of experiencing another panic attack once they have been associated with aversive responses. Furthermore, the risk variant of a polymorphism in the monoamine oxidase A gene was observed to augment the occurrence of panic attacks and escape behavior preparation. In addition, we find evidence that suggest an enhanced resistance to corrective learning experiences as indicated by a lack of a reduction of avoiding and escaping behavior during repeated test chamber exposures in wait-list control patients carrying the risk gene variant. Both effects may strengthen the learning mechanism hypothesized to be involved in the pathogenesis of panic disorder. Exteroceptive and interoceptive cues previously associated with the initial panic attack might trigger subsequent attacks in risk allele carriers more rapidly while simultaneously the opportunity to dissolve once established associations due to contradictory experiences is limited. Now, differential dispositions regarding defensive reactivity in PD/AG patients has to be linked to mechanisms supposed to be involved in exposure based therapy. First outcome evaluations of the clinical trial indicated that a behavioral therapy variant suggested to be linked with higher fear activation during exposure exercises is more effective than another. Further analyses have to proof whether those patients showing a clear specific fear response during the behavioral avoidance test benefit more than others from exposure based therapy.
Chaetognaths are a fascinating taxon with unique features and a great impact on marine food webs as primary predators of zooplankton. Their phylogenetic position has been subject to many speculations ever since their discovery and even contemporary phylogenomic methods have not yet been able to suggest a stable hypothesis on their phylogenetic position within the Bilateria. Neuroanatomical studies may contribute new aspects to this discussion. This study aims to provide new insights into the chaetognath nervous system using a fresh set of methods to determine characters for a phylogenetic discussion. The method of choice in this case was immunohistochemistry combined with confocal microscopy. Experiments were conducted with a host of antibodies. The most effective target antigenes were RFamides (a family of neuropeptides), synapsins (synaptic proteins), tyrosinated tubulin (a cytoskeletal element, especially in neurites) and BrdU (bromodeoxyuridin, a proliferation marker). Each of those markers was of great use in highlighting certain aspects of the nervous system. A fresh look at the development of juvenile chaetognaths shortly after hatching revealed that the ventral nerve center (VNC) is developing earlier than the brain and that the production of neurotransmitters has already started at hatching. Specifically, some neurons exhibit RFmide-like immunoreactivity (ir). Neurogenesis continues for about five days after hatching and the mode of division in the neuronal stemcells is asymmetrical. In adult chaetognaths, the brain is divided into a stomatogastric anterior and a sensory posterior neuropil domain. It contains a set of individually identifiable neurons that exhibit RFamide-like ir. The study highlights the interspecific variation of brain architecture between representatives of spadellids and sagittids. The VNC consists of two lateral bands of somata that flank a central neuropil. Within the VNC exists a serial arrangement of neurons with RFamide-like ir. A variety of other neurotransmitters and related substances are also present in both, the brain and the VNC. More interspecific differences and similarities were explored in another part of the study, comparing even more different chaetognath species and focusing on the VNC and its internal structure. The two species of Krohnitta have an unusual distribution of nuclei that is not clearly separated into two lateral bands like in other species. Many of the sagittid species exhibit a striation pattern of the neuropil that is mostly absent in other groups and some of their nerve nets show varying degrees of order as opposed to the rather disorganized nerve net in other groups. In addition, immunohistochemical methods were applied to several specimens of Gnathostomula sp. in order to test one of the many hypotheses about the chaetognaths phylogenetic position, a sister-group relationship to gnathostomulids. A comparison between the two taxa, taking into account also other gnathifera and platyhelminthes, makes a sistergroup relationship between chaetognaths and gnathostomulids very unlikely. In conclusion, chaetognaths remain in an enigmatic phylogenetic position and likely branched off close to the deuterostome/protostome split.
Rainbow trout (Oncorhynchus mykiss) represents the third most produced species of diadromous fish, with the total production of 0,732 million tonnes in 2009. More than one third of this production comes from Europe, where it is dominated by Norway, Italy and France. Germany is the fifth biggest producer in Europe, producing 21 thousand tonnes of rainbow trout in the value of 6,1 million Euro. However, the conditions in the intensive aquaculture often increase the disease susceptibility to many pathogens. One of the highest economic threats for a salmonids aquaculture is the causative agent of furunculosis, Aeromonas salmonicida subsp. salmonicida. Several strategies have been developed to protect the fish, but the traditional methods are either laborious or represent a potential risk for the environment. The selective breeding established more than 35 years ago in the brackish waters of Baltic Sea represent a attractive alternative, delivering a novel strain of rainbow trout better adapted to the brackish environment and exhibiting reduced mortality in the infection with A.salmonicida. Nevertheless, no information was available about the fundaments of this phenomenon. Thus, the aim of presented study was the identification of immune adaptations, which occurred during the 30 years of selection and favoured increased survival of “born” trout to the bacterial diseas es. In the presented work, the peritoneal cavity of rainbow trout has been used as a model for the investigation of disease resistance in fish. In the first chapter, the peritoneal cavity has been described as a unique niche of teleost immune system and the kinetic of peritoneal leukocytes induced by the stimulation has been analysed. Furthermore, a unique set of monoclonal antibodies has been used to evaluate the contribution of distinct cell populations on the inflammation and its resolution. In the second part of the study, the transcriptional changes of peritoneal leukocytes have been evaluated using the GRASP microarray. The following analysis provided unique insights into the local immune response in rainbow trout. The unprecedented combination of both data sets offers an unparalleled description of the local immune response in teleost fish and can be summarized into following facts. In general, the obtained results revealed, that the unstimulated peritoneal cavity is populated predominantly by lymphocytes with IgM+ Bcells being the major cells type. The rapid changes in the composition induced by the stimulation were underlined by the upregulation of major proinflammatory molecules such as IL1β, IL8 and TNFα within 12hpi. Although the initial phase of the reaction was dominated by myeloid cells, the cavity underwent within 72 hours two complete changes in the composition corresponding with the massive changes in the transcriptome. Eventually, the resolution of inflammation was marked by an increasing number of lymphocytes and correlated with the downregulation of pro-inflammatory genes to the initial level and upregulation of anti-inflammatory cytokines IL10 and TGFβ. Besides the general observations common to all treatments and both strains, our experiments revealed also remarkable differences between the antigenic stimulation and reaction towards pathogen. From these differences following conclusions can be drawn; the infection induces comparable reaction pattern as the stimulation, although the intensity of the reaction and number of cells is higher. These observations correlated with the higher expression of inflammatory molecules after the infection. Viable bacteria also prolong the myeloid phase of the reaction and delay the resolution of inflammation. Finally, model of peritoneal inflammation caused by A. salmonicida has been applied also to the second strain of rainbow trout, known for its higher resistance to infection. The comparison of obtained data suggested that resistant trout reacted to the antigenic stimulation and infection with a lower number of cells despite minor differences in the expression level of major pro-inflammatory molecules during early stages of the infection. Eventually, the resolution of inflammation and onset of adaptive immune response occurred in resistant trout almost 24 hours earlier and was correlating with an increased expression of anti-inflammatory cytokines IL10 and TGFβ. Notably, the increased survival of resistant strain correlates with the increased expression of antibacterial proteins such as NRAMP and hepcidin. Taken together, obtained data provided unprecedented insights into the local immune response in teleost fish and identified features conserved during the selection breeding in the brackish water of Baltic Sea. Additionally, combination of cellular and molecular data elucidates the peritoneal inflammation in fish and suggested high conservation of the immune response in the evolution.
Hantaviruses (family Bunyaviridae) are enveloped viruses with a segmented RNA genome of negative polarity. They can cause two different diseases in humans, the hemorrhagic fever with renal syndrome in Europe and Asia and the hantavirus cardiopulmonary syndrome in America. The transmission to humans is mainly indirect by inhalation of aerosolized virus-contaminated rodent excreta. In contrast to the initial assumption that hantaviruses are mainly carried by rodents, during the last years many novel hantaviruses were detected in shrews, moles and recently in bats. These findings raise important questions about the evolutionary history of hantaviruses, their host association and adaptation, the role and frequency of spillover infections and host switch events. This study aims to prove the presence, geographical distribution and host association of the rodent-borne Tula virus (TULV) and the shrew-associated Seewis virus (SWSV) in Central Europe. For this purpose, novel laboratory techniques for molecular and serological hantavirus detection were developed. Initially, a broad-spectrum molecular assay to identify small mammal species from Central Europe was developed. This novel assay is based on PCR amplification using degenerated primers targeting the cytochrome b (cyt b) gene, nucleotide sequence analysis of the amplified cyt b gene portion and followed by pairwise sequence comparison to published sequences using the BLAST function of GenBank. Different small mammal species prevalent in Central Europe could be determined by this new approach, including not only representatives of various Rodentia and Soricomorpha, but also representatives of the orders Erinaceomorpha, Lagomorpha, Carnivora and Chiroptera. For characterization of insectivore-borne hantavirus Thottapalayam virus (TPMV), specific monoclonal antibodies were generated that detect native virus in infected mammalian cells. For the detection of TPMV-specific antibodies, Asian house shrew Suncus murinus immunoglobulin G (IgG)-specific antibodies were produced in laboratory mice and rabbit. Using this anti-shrew IgG and recombinant TPMV nucleocapsid (N) protein, an indirect enzyme-linked immunosorbent assay (ELISA) was developed allowing the detection of TPMV N protein-specific antibodies in immunized and experimentally TPMV infected shrews. A Pan-Hantavirus SYBR-Green RT-qPCR was developed for the search to novel hantaviruses. By this novel RT-qPCR and other conventional RT-PCR approaches, TULV infections were identified for the first time in the Eurasian water vole Arvicola amphibius from different regions in Germany and Switzerland. The phylogenetic analyses of the different partial TULV small (S)-, medium (M)- and large (L)-genome segment sequences from A. amphibius, with those of Microtus arvalis- and M. agrestis-derived TULV lineages, revealed a geographical, but host-independent clustering and may suggest multiple TULV spillover or a potential host switch from M. arvalis or M. agrestis to A. amphibius. In a further comprehensive study, different shrew species (Sorex araneus, S. minutus, S. coronatus, and S. alpinus) were collected in Germany, Czech Republic, and Slovakia and screened by another L-segment-targeting Pan-Hantavirus RT-PCR approach. This screening revealed hantavirus L-segment sequences in a large number of S. araneus and a few S. minutus indicating a broad geographical distribution of this hantavirus. For detailed analyses, S-segment sequences were obtained, from S. araneus and S. minutus. The sequences demonstrated their similarity to SWSV sequences from Hungary, Finland, Austria and Germany. A detailed phylogenetic analysis showed low intra-cluster sequence variability, but high inter-cluster divergence suggesting a long-term SWSV evolution in local shrew populations. In conclusion, the investigations demonstrated a broad geographical distribution and multiple spillover infections of rodent-borne TULV and shrew-borne SWSV in Europe. The finding of putative spillover transmissions described here and in other studies underline the current problem of the hantavirus reservoir host definition. In contrast to the hypothesis of a long-standing hantavirus–rodent (small mammal) host coevolution, the investigations support a more dynamic evolutionary history of hantavirus diversification including spillover infections and host-switch events. In future in vitro and in vivo infection studies as well as field studies has to define factors determining the host specificity of these hantaviruses.
This thesis will discuss the different fields of application of the two soft ionization techniques ESI and MALDI in microbial proteomics and their importance for a better understanding of bacteria physiology. The general development in the past 25 years coming from 2D-gel analysis and protein identification by peptide mass fingerprint analysis via MALDI-TOF to genome wide quantitative LC-ESI-MS experiments with fast and sensitive ESI instruments is exemplary shown for the Gram-positive bacterium Bacillus subtilis in article I. Even though 2D-PAGE in conjunction with MALDI-MS is still an important tool in proteomic research, the more recently established global quantitative LC-ESI-MS workflows gain more and more relevance as they overcome 2D-PAGE based protein restrictions and enable the acquisition of higher accurate protein quantities. In article II such a workflow was used to analyze the physiological adaptation of Staphylococcus aureus to vancomycin treatment on a global-scale. Also post-translational modifications of proteins, that are important for regulation of their activity and allow rapid adaption to changed environmental conditions, could be analyzed by LC-ESI-MS workflows using special enrichment strategies (article III and IV). Despite the mentioned discrimination and less accurate quantification of proteins, 2D-PAGE analyses are still advantageous when analyzing large-scale time series experiments. To gain highly time resolved data but also very accurate relative quantities on a global-scale, 2D-PAGE-MALDI-MS and LC-ESI-MS techniques have been combined to investigate dynamic proteome adaptations of B. subtilis during nutrition shift as part of a global systems biology approach (article V). Also absolute quantities of proteins are of high interest for systems biology, but are still challenging to obtain on large-scale as well as with sufficient accuracy. In article VI a method that again combined 2D-PAGE-MALDI-MS and LC-ESI-MS was introduced to gain absolute protein quantities on global-scale. Utilizing the complementarity of 2D-PAGE and LC-ESI-MS this new workflow enabled fast and cost efficient data acquisition on absolute scale. In article VII we described for the first time a global quantitative LC-MALDI-MS workflow. Cross validation with an LTQ Orbitrap proofed that LC-MALDI-MS is able to process complex samples and obtain highly reliable quantities. The comparative analysis of data gained with both instrument types revealed biases for certain biochemical properties of MALDI as well as ESI instruments, resulting in a general complementarity of both ionization techniques. Article I Becher, D., Büttner, K., Moche, M., Hessling, B., Hecker, M., 2011. From the genome sequence to the protein inventory of Bacillus subtilis. Proteomics 11, 2971–2980. Article II Hessling,B., Bonn,F., Herbst,F.-A., Rappen,G.-M., Bernhardt,J., Hecker,M. and Becher,D. Global proteome analysis of vancomycin stress in Staphylococcus aureus. Submitted to Mol. Cell Proteomics. Article III Elsholz, A.K.W., Turgay, K., Michalik, S., Hessling, B., Gronau, K., Oertel, D., Mäder, U., Bernhardt, J., Becher, D., Hecker, M., Gerth, U., 2012. Global impact of protein arginine phosphorylation on the physiology of Bacillus subtilis. Proc. Natl. Acad. Sci. U.S.A. 109, 7451–7456. Article IV Chi, B.K., Gronau, K., Mäder, U., Hessling, B., Becher, D., Antelmann, H., 2011. S-bacillithiolation protects against hypochlorite stress in Bacillus subtilis as revealed by transcriptomics and redox proteomics. Mol. Cell Proteomics 10, M111.009506. Article V Buescher,J.M., Liebermeister,W., Jules,M., Uhr,M., Muntel,J., Botella,E., Hessling,B., Kleijn,R.J., Le Chat,L., Lecointe,F., et al. (2012) Global network reorganization during dynamic adaptations of Bacillus subtilis metabolism. Science, 335, 1099–1103. Article VI Maass, S., Sievers, S., Zühlke, D., Kuzinski, J., Sappa, P.K., Muntel, J., Hessling, B., Bernhardt, J., Sietmann, R., Völker, U., Hecker, M., Becher, D., 2011. Efficient, global-scale quantification of absolute protein amounts by integration of targeted mass spectrometry and two-dimensional gel-based proteomics. Anal. Chem. 83, 2677–2684. Article VII Hessling,B., Büttner,K., Hecker,M. and Becher,D. Global relative quantification with LC-MALDI – cross-validation with LTQ-Orbitrap proves reliability and reveals complementary ionization preferences. Submitted to Mol. Cell Proteomics.
Chronic infections, including periodontal infections, may reduce lung function. To date, there are hardly any population-based studies evaluating the association between periodontitis and lung function. However, there are some studies that used variables associated with obstructive pulmonary diseases (FEV1, FEV1/FVC). Thus, we aimed to assess the potential association of periodontal diseases with lung volumes and airflow limitation in the population-based Study of Health in Pomerania (SHIP). Of 3300 participants aged 25-85 years of the 5-year follow-up (SHIP-1), 1809 subjects participated in lung function examinations. 1465 subjects were included in the analyses. Lung function was measured using spirometry, body plethysmography, helium dilution, and diffusing capacity for carbon monoxide. Periodontal status was assessed by clinical attachment loss, probing depth, and number of missing teeth. Linear regression models using fractional polynomials were used to assess linear and non-linear associations between periodontal disease and lung function adjusting for confounders. Adjusting for age, sex, waist circumference, physical activity, diabetes, asthma, and time between core and pulmonary examination, mean attachment loss was significantly associated with variables of dynamic and static lung volumes, airflow limitation and hyperinflation. Total lung capacity and diffusing capacity for carbon monoxide were not associated with mean attachment loss. Adjustment for smoking and height considerably changed coefficients indicating profound confounding. Including fibrinogen and high sensitive CRP into fully adjusted models did not change coefficients of mean attachment loss. Restricted to never smokers, mean attachment loss was significantly associated with FEV1, FVC, and RV/TLC. Relations with lung function were confirmed for mean probing depth, extent measures of attachment loss/probing depth, and number of missing teeth. Periodontal disease was significantly associated with decreased lung function. Systemic inflammation did not provide a mechanism linking both diseases. However, cohort studies evaluating lung function in the current manner are needed to confirm results from this study and to assess a causal relationship. Furthermore, it needs to be investigated with the help of randomized clinical trials whether prevention or treatment of periodontitis might have a beneficial impact on lung function.
The biological decontamination and sterilization is a crucial processing step in producing and reprocessing of medical devices. Since polymer-based materials are increasingly used for the production of medical devices, the application of conventional sterilization processes are restricted to a certain extent. Conventional sterilization techniques on the basis of high temperatures, toxic gases, or ionizing radiation can be detrimental to the functionality and performance of polymeric materials. For this reason, alternative, gentle, and efficient decontamination processes are required. One possible approach is the use of non-thermal physical plasmas. Especially atmospheric pressure plasma is receiving great interest due to the absence of vacuum systems which is highly attractive for the practical applicability. Its mechanisms of action enable the efficient killing and inactivation of micro-organisms which are attributed to the interaction of plasma-generated reactive oxygen and nitrogen species (ROS, RNS) as well as plasma-emitted (V)UV radiation. Owing to the moderate gas temperatures (near or at room temperature) so-called cold plasmas are well-suitable for the treatment of heat-sensitive materials, such as polymers, without affecting their bulk properties. The present work focuses on the investigation of atmospheric pressure plasma processes for the biological decontamination of polymers. The objective is to help elucidate on the one hand the impact of varied plasma process parameters on the inactivation of micro-organisms and on the other hand the influence of plasma on the surface properties of the substrate. The investigations were performed by means of a high-frequency driven plasma jet (from the product line kINPen) operated with argon and argon-oxygen mixtures. Three main aspects were analyzed: 1. The effect of plasma on the viability of micro-organisms dependent on working gas, treatment time, and the sample distance (distance between the jet nozzle and the substrate). 2. The plasma-based removal of microbial biofilms. 3. The effects of the plasma treatment on the surface properties of selected polymers. Additionally to the capability of the applied plasma jet in killing microbes the efficacy of this plasma jet for the removal of complex biological systems (e.g. biofilms) is shown. To model cell constituents of bacteria different synthetic polymers were chosen to gain insight into the decomposition process responsible for biofilm degradation. By investigating the impact of atmospheric pressure plasma on physico-chemical surface properties of various synthetic aliphatic and aromatic polymers the interaction mechanisms between plasma and plasma-exposed material are discussed. These studies are accompanied by applying different optical plasma diagnostic techniques (optical emission spectroscopy and two-photon absorption laser induced fluorescence spectroscopy) to obtain information on the plasma gas phase which contributes to the elucidation of the reaction mechanisms occurring during plasma exposure. Moreover, it is presented to which extent the plasma treatment influences the surface properties of polymers during the plasma-based bio-decontamination process and further, the benefits of surface-functionalized polymers for biomedical application is discussed.
The goal of this thesis was to study the systematic relationships within the superfamily Sylvioidea (Aves: Passeriformes) in general and within the closely related families Acrocephalidae and Locustellidae in particular, by means of DNA sequences. Sylvioidea itself and families therein were the focus of many studies based as well on morphological characters as on DNA. Due to their morphological similarity and their presumably rapid radiation most studies failed to solve relationships between sylvioidean families and also demarcations of single families and relations within are still in progress. In this study, an enlargement of previous datasets, both taxa and number of DNA sequences, and more sophisticated analysis methods were used to improve the resolution in Sylvioidea, Acrocephalidae and Locustellidae. In addition, the applicability of barcoding in Acrocephalidae was tested. The monophyly of Sylvioidea could be supported and the families Paridae and Remizidae, which were sometimes still included, clustered among the outgroup taxa. Four families, Nicatoridae, Panuridae, Alaudidae, and Macrosphenidae constitute basal splits within Sylvioidea. The division of the former sylviid/timaliid clade in five families, Sylviidae, Leiothrichidae, Pellorneidae, Timaliidae, and Zosteropidae was supported. Scotocerca, Erythrocercus, and Hylia, previously supposed to be members of Cettiidae, were shown not to belong to this family. As the three genera are also morphologically and ecologically different, they were here proposed to be elevated to family rank, Scotocercidae, Erythrocercidae and Hyliidae, respectively. The family Acrocephalidae consisted of the four genera, Nesillas, Acrocephalus, Hippolais, and Chloropeta. In the analysis for this thesis, the latter three appeared to be non-monophyletic. One Acrocephalus species, A. aedon was sister to a clade containing four species of Hippolais as well as two out of three Chloropeta species. They were all merged in the genus Iduna, based on the DNA evidence and shared morphological and ecological characters. Iduna had priority over Hippolais or Chloropeta according to the International Code of Zoological Nomenclature. The one remaining Chloropeta species (C. gracilirostris) had to be renamed to Calamonastides as Chloropeta was no longer available for this taxon. Seven genera were included in the re-analysis of the family Locustellidae: Locustella, Bradypterus, Megalurus, Dromaeocercus, Schoenicola, Cincloramphus, and Eremiornis. Apart from the monotypic genera Dromaeocercus and Eremiornis and Schoenicola, of which only one species was included, the remaining genera were found to be non-monophyletic. One clade contained all Locustella species, Megalurus pryeri and all Asian/Oriental Bradypterus species. All species in this clade were synonymized with Locustella, as the type species of Locustella was included, whereas the type species of Bradypterus fell in a different clade. Therefore, the remaining African Bradypterus species retained their genus name, and Dromaeocercus was renamed to Bradypterus as it clustered within Bradypterus. Cincloramphus, intermingling with the remaining Megalurus species, was synonymized with the latter. Barcoding, growing in popularity for delimiting species, was tested in its applicability for Acrocephalidae. Fourteen taxa currently recognized as full species would fall under the 2% threshold of sequence divergence proposed for delimiting species using the mitochondrial cytochrome b gene. It was also shown that it is important to clarify which part of a DNA sequence is used, as different parts can give different results regarding the 2% threshold. In addition, the choice of “complete deletion” or “pairwise deletion” in calculating genetic distances is important, if incomplete are sequences used.
Quantum-Kinetic Modeling of Electron Release in Low-Energy Surface Collisions of Atoms and Molecules
(2012)
In this work we present a theoretical description of electron release in the collision of atomic and molecular projectiles with metallic and especially dielectric surfaces. The associated electron yield, the secondary electron emission coefficient, is an important input parameter for numerical simulations of dielectric barrier discharges and other bounded low-temperature gas discharges. The available reference data for emission coefficients is, however, very sparse and often uncertain, especially for molecular projectiles. With the present work we aim to contribute to the filling of these gaps by providing a flexible and easy-to-use model that allows for a convenient calculation of the emission coefficient and related quantities for a wide range of projectile-surface systems and the most dominant reaction channels.
In this thesis, all three BVMOs from Pseudomonas putida NCIMB10007, that were known to be responsible for the ability of this strain to degrade camphor since the 1950s were successfully made available as recombinant biocatalysts. While the genomic sequence of 2,5-DKCMO was available from the database, the genes encoding 3,6-DKCMO and OTEMO had to be identified using certain PCR-techniques first. All three enzymes were cloned into standard plasmids enabling convenient expression in E. coli facilitating the application of the enzymes in organic chemistry. Their synthetic potential was already reported during the 1990s, but at that time their efficient application was limited due to difficulties with respect to low production levels and insufficient purity and separation of enzyme fractions. These drawbacks are now overcome. Furthermore, biochemical characterization of the camphor-degrading BVMOs was performed including the substrate spectra of these enzymes. Thereby OTEMO turned out not only to have a broad substrate scope accepting mono- and bicyclic aliphatic and arylaliphatic ketones, but also to efficiently convert alpha/beta-unsaturated cycloalkanones due to the similarity of these compounds to OTEMOs natural substrate. Finally, the major limitation in the synthetic application of Type II BVMOs was addressed by searching a flavin-reductase suitable for coupling to these two-component oxygenases. Putative candidates from the respective P. putida strain were identified by the use of amino acid motifs conserved in other representatives of two-component systems. While these enzymes failed, flavin-reductase Fre from E. coli - that also contained the motifs - was shown to enhance the activity of the DKCMOs when applied as crude cell extract as well as pure enzyme. This finding represents a key step for future application of Type II BVMOs.
Written language in the public sphere (shop signs, advertisements, placards, graffiti, etc.) constitutes the “Linguistic Landscape” of an urban agglomeration. An examination of such displays gives us an insight into function, status and spread of certain languages. Here, the study of linguistic landscapes does not only bear a purely linguistic dimension, but necessarily links to other fields such as politics, semiotics, urban development, communication and literacy. In this case study the cityscapes of the Moldovan capital Chisinau and the Lithuanian capital Vilnius will be analyzed. Peripheral and central districts of the cities have been chosen. From each of these districts, data on the number of mother tongue speakers have been obtained. Two corpora, each containing 1000 items of specimen of written language have been made and contextualized with the help of GPS tracking to ensure the possibility of future diachronic research. The data for these corpora was collected in December 2010 and March 2011. The aim of this study is two-fold: On the one hand this approach gives an insight into the general use of different languages in Moldova and Lithuanian as well as on the functional domains they fulfill. On the other hand the distribution of different languages on signs in each district shows how minority languages such as Russian are represented in public. The results suggest that the linguistic landscape of Chisinau is actually very diverse and alongside Romanian, English and especially Russian are used frequently. The functional domains differ though. Whereas the national language is part of almost all shop signs and advertising in general, it is usually used in conjunction with Russian. Informal displays of written language such as graffiti or small placards are mostly written in Russian alone. Other minority languages in Moldova such as Gagauz and Ukrainian were almost never visible on written displays of language in the city. In contrast to that the linguistic landscape of Vilnius is far less diverse and although the Lithuanian capital is home to sizeable Russian- and Polish-speaking minorities, these demographic patterns do not show. Yet, apart from Lithuanian English is an integral part of the linguistic landscape, especially in advertising.
Acute pancreatitis is a common clinical inflammatory disease with variable severity from mild, self-limiting attacks to a severe lethal attack with a high mortality. In most of the cases, acute pancreatitis is either caused by gallstone obstruction or excessive alcohol consumption. Clinical symptoms include elevated levels (minimum 3 times than normal) of pancreatic enzymes such as amylase or lipase in serum. It is generally believed that earliest event in acute pancreatitis occur in acinar cells which includes premature protease activation and cytoplasmic vacuole formation. Premature trypsinogen activation has been considered as chief culprit as it can activate other proteases in a cascade like manner in acinar cells. Trypsin activity takes place in a biphasic curve with elevated levels at 1 h and 8 h in the initial stages up to 24 h in caerulein induced pancreatitis in mice. It has been shown that cytoplasmic vacuoles observed in pancreatitis are of autophagic nature. The role of autophagy for the disease onset and its role in trypsinogen is much of a debate. Hence, we studied the relation between autophagosome formation and trypsinogen activation in first 12h of pancreatitis. Although autophagosomes were found to be co-localised with trypsin in vivo, this was found to be a late event occuring only by 4 h. Substrate specific trypsin activity and western blotting from both sub-cellular fractions over the time course of pancreatitis and multiple fractions prepared from 1 h caerulein induced pancreatic tissue revealed that trypsin activity observed at 1 h occured in a zymogen enriched fraction. In line simultaneous confocal imaging of trypsin activity and autophagosome formation in hyperstimulated acini isolated from GFP-LC3 mice showed that both processes are independent and take place in parallel. Furthermore, protease inhibition by gabexate mesilate did not prevent autophagosome formation indicating that trypsinogen activation is not a prerequisite for vacuole formation. Even though, autophagosomes and active trypsin were found to be co-localised around 30 minutes to some degree upon cholecystokinin hyperstimulation, the earliest trypsin activation started to appear by 15 minutes and was independent of autophagosomes. The earliest active trypsin was found to be co-localised along with the cis-Golgi complex suggesting that the Golgi apparatus and its pre-condensed zymogen granules are the compartment responsible for the trypsinogen activation. 2) Protease activation in pancreatic acinar cells considered as the early hallmark event in the acute pancreatitis. However, the disease is aggravated by the infiltration of the leukocytes. Activated proteases mediate acinar cell injury and hereby cause the release of chemokines, which in turn attract inflammatory cells. Transmigrated inflammatory cells cause systemic damage that deteriorates the condition of the disease. Neutrophil elastase has been reported to be involved in the dissociation of cell-cell contact at adherens junctions by the extracellular cleavage of E-cadherin. This subsequently leads to transmigration of leukocytes into the epithelial tissue during the initial phase of experimental pancreatitis and aggravates the disease condition. On the other hand, pancreatic elastase substantially contributes to acinar cell necrosis. In this study, ZD0892, an orally bioavailable dual inhibitor against both elastases was tested for its efficacy to ameliorate severity in acute pancreatitis. ZD0892 orally fed mice showed increased survival compared to the control group in the taurocholate model of severe pancreatitis. In the initial stages of pancreatitis up to 24 h, the severity markers were found to be significantly lower in the inhibitor treated group. Treatment of mice with ZD0892 did not impede the defensive property of the leukocytes such as phagocytosis or oxidative burst. In caerulein induced pancreatitis, a mild form of acute pancreatitis, in rats, the local damage measured as serum amylase and lipase, wet dry ratio, and pancreatic myeloperoxidase levels were significantly lower in the inhibitor group. Systemic inflammatory parameters such as myeloperoxidase activity in lung was found to be significantly lower in the inhibitor fed rats. Inhibitor feeding resulted in lesser elastolytic activity compared to control group indicating that extracellular matrix was less damaged. Prophylactic treatment of pancreatitis with an orally available inhibitor with a dual specificity against pancreatic elastase and PMN-elastase was shown to ameliorate both local and systemic damage. Hence, in overall, ZD0892 treatment is proved to be beneficial to the mice and rats in experimental pancreatitis and should be considered for treatment in humans as the substance has been already studied in phase I and II trails for other indications.
Streptococcus pneumoniae (pneumococci) are Gram-positive cocci and commensals of the human upper respiratory tract. Pneumococcal pathogenesis requires adherence to host cells and dissemination through cellular barriers and to evade host defense mechanisms. The Pneumococcal surface protein C (PspC) is an important virulence factor which has a crucial role in pneumococcal adhesion to host cells and immune evasion by manipulating the host complement system. To elucidate the pneumococcal adherence and uptake mechanism via factor H glycosaminoglycans (dermatan sulfate and heparin) were employed as competitive inhibitors in infection experiments with epithelial cells or human polymorphonuclear leukocytes (PMNs). Glycosaminoglycans significantly inhibited the FH mediated pneumococcal adherence and subsequent invasion to host epithelial cells. Furthermore, the short consensus repeats of FH which promotes the adhesion of pneumococci to host cells were identified by blocking experiments with domain mapped antibodies for specific regions of FH. Moreover, this study indicates that FH acts as adhesion molecule via cellular receptors recognized as integrin CR3 on human PMNs. Binding of Factor H loaded pneumococci to integrins CR3 was assessed by flow cytometry. Pneumococci coated with Factor H showed a significantly increased association with PMNs. This interaction was blocked by anti-CR3 antibodies and Pra1. This project further aims to study mechanisms of pneumococcal endocytosis by host cells, their intracellular fate, and the pathogen induced host cell signal transduction cascades including the calcium signaling upon pneumococcal infection of host cells via the PspC-hpIgR interaction. To assess now the role of protein tyrosine kinases (PTKs) during pneumococcal infection via PspC, cell culture infections were performed in presence of pharmacological inhibitors of PTKs and MAPKs or by employing genetic interference techniques. Blocking the function of Src or ER1/2 and JNK and genetic-knock down of Src and FAK reduced significantly internalization of pneumococci. These data indicated the importance of a coordinated signaling between Src PTKs, ERK1/2, and JNK during PspC-pIgR-mediated uptake of pneumococci by host epithelial cells. The impact of host cells intracellular calcium concentrations on pneumococcal PspC-hpIgR mediated internalization was studied. Intracellular calcium measurement of epithelial cells performed in the presence of pneumococci suggested a calcium influx in host epithelial cells and importantly this calcium influx was PspC- hpIgR specific as pspC-deficient pneumococci were unable to mediate calcium mobilization in host cells. The increase in intracellular calcium [Ca2+]i was dependent on phospholipase C as pretreatment of cells with a phospholipase C-specific inhibitor abolished the increase in [Ca2+]i. Furthermore, role of host intracellular calcium concentrations during pneumococcal internalization was demonstrated by employing specific pharmacological inhibitors and calcium chelators in epithelial cell culture infection assays. The results revealed that elevated host cells calcium concentrations diminished pneumococcal internalization while lower calcium concentration in host epithelial cells promoted pneumococcal uptake. This study further demonstrates that dynamin, clathrin and caveolin play a key role during pneumococcal endocytosis into host cells via PspC-hpIgR. The use of specific pharmacological inhibitors or genetic interference approaches against dynamin, clathrin and caveolin in epithelial cell culture infection assays significantly blocked pneumococcal uptake. Furthermore, confocal microscopy revealed that pneumococci co-localize with clathrin. At later stages of the infection the pathogen is sorted to early, late and recycling endosomes as indicated by co-localization of pneumococci with endosomal markers such as Rab5, Rab4, Rab 7, and Lamp1. In order to get further insights into PspC-hpIgR mediated uptake mechanisms, a chimeric PspC was constructed and expressed heterologously on the surface of Lactococcus lactis. Immunofluorescence staining, immunoblot and flow cytometric analysis of L. lactis confirmed the expression of PspC on the bacterial surface. Moreover the ability of recombinant lactococci expressing PspC to adhere to and to invade pIgR-expressing epithelial cells confirmed the functional activity of PspC when exposed on the lactococcal surface. PspC expressing lactococci confirmed the specificity of PspC-hpIgR mediated endocytosis in host epithelial cells as PspC deficient lactococci were not taken up by these host cells. Confocal microscopic analysis demonstrated that only PspC expressing lactococci were sorted to early, late and recycling endosomes, similar to the intracellular fate of S. pneumoniae.
Independence is a basic concept of probability theory and statistics. In a lot of fields of sciences, dependency of different variables is gained lots of attention from scientists. A measure, named information dependency, is proposed to express the dependency of a group of random variables. This measure is defined as the Kullback-Leibler divergence of a joint distribution with respect to a product-marginal distribution of these random variables. In the bivariate case, this measure is known as mutual information of two random variables. Thus, the measure information dependency has a strong relationship with the Information Theory. The thesis aims to give a thorough study of the information dependency from both mathematical and practical viewpoints. Concretely, we would like to research three following problems: 1. Proving that the information dependency is a useful tool to express the dependency of a group of random variables by comparing it with other measures of dependency. 2. Studying the methods to estimate the information dependency based on the samples of a group of random variables. 3. Investigating how the Independent Component Analysis problem, an interesting problem in statistics, can be solved using information dependency.
Abstract Atmospheric Pressure Discharges have attracted much interest in recent years. The development of a new processes based on this discharge needs a clear understanding of plasma and discharge physics and chemistry. At the present time much attention is paid to the chemical processes in barrier discharge plasma in various gas mixtures, since the understanding of these processes is necessary for the development of industrial reactors. Besides these, hydrocarbons are being used for the formation of diamond like or amorphous carbon (DLC) films. Specially, hydrogenated amorphous carbon (a-C: H) and plasma polymerization. In this work we have used Dielectric Barrier Discharge (DBD) a plasma device used to investigate simple hydrocarbon reactions in a plasma phase. Our aim of plasma phase chemical reaction studies is to form molecular hydrogen, higher order hydrocarbons CnHm up to n ≥ 12 series and nitrogen - containing organic complexes using simple hydrocarbons. Deposition of thin organic films or DLC films were carried out using the DBD. In this study we have chosen certain combination of gases such as C2Hm/N2 (m = 2, 4, 6) and C2Hm/Ar (m = 2, 4, 6); the purpose of using N2 and Ar gases are to dilute and stabilize the hydrocarbon plasma and to investigate plasma chemical reactions with nitrogen gas. All reactions were carried out under an atmospheric pressure (300 mbar) with gas ratio 1:2; Experiments were performed by applying high voltage with a frequency 5.5 kHz. The plasma phase diagnostics have been investigated using mass spectrometry and FTIR spectroscopy. Formation of molecular hydrogen, N-containing organic complexes and higher order hydrocarbons with C ≥ 12, have been investigated with mass spectrometry. FTIR spectroscopy reveals the formation of substituted alkanes (sp3), alkenes (sp2) and alkynes (sp) and nitrogen containing functional groups from the individual gases which are used in this work. Abundant formation of acetylene occurs with C2H6 and C2H4 as precursor gases. Amorphous hydrogenated carbon nitride (a-CNx:H) films have been deposited on Si (100) and glass substrates using gas mixtures C2Hm/N2 (m = 2, 4, 6). Surface chemical compositions have been derived from Fourier Transform Infrared Reflection Absorption Spectroscopy (FT-IRRAS) and X-ray Photo electron Spectroscopy (XPS). FT-IRRAS and XPS show the presence of sp, sp2 and sp3 bonds of carbon and nitrogen for C2Hm/N2 thin films. Various functional groups such as amines, saturated and unsaturated alkyl groups have been identified. Thin films obtained from C2H2/N2 and C2H4/N2 gas mixture had a larger N/C ratio when compared to the film obtained from C2H6/N2. Thickness, refractive index and extinction co-efficient were investigated by ellipsometry. Rate of deposition have been investigated. Different surface morphology has been derived using Scanning Electron Microscopy. Amorphous hydrogenated carbon (a-C:H) films or diamond like carbon (DLC) films have been deposited on Si (100) and glass substrates using gas mixtures C2Hm/Ar (m = 2, 4, 6). Diagnostics for the deposited films have been done using different spectroscopic techniques. Surface chemical compositions have been derived from Fourier Transform Infrared Reflection Absorption Spectroscopy (FT-IRRAS) and X-ray Photo electron Spectroscopy (XPS). FT-IRRAS show the presence of sp, sp2 and sp3 bonds of carbon and hydrogen for C2Hm/Ar (m = 2, 4, 6) thin films. The characteristic peak for C1s has been observed from XPS. Thickness, refractive index and extinction co-efficient were investigated by ellipsometry. Rate of deposition have been investigated.
This thesis describes investigations of metal clusters stored in an ion-cyclotron resonance (ICR) trap, as well as corresponding trap research and development. Charged clusters are produced and investigated in the experimental setup Cluster-Trap, comprising a cluster-ion source, an ICR trap and a time-of-flight (ToF) mass spectrometer. In the framework of its move to the new building of the Institute of Physics, new components have been added to the ClusterTrap setup. A radio-frequency ion trap is now used for cluster ion preparation prior to the performance of cluster experiments in the ICR trap. A quadrupole ion deflector allows an optimized usage of the ICR trap, as well as simultaneous use of several ion sources and detectors. The implementation of a potential lift at the ToF mass spectrometer enables a more flexible operation of the setup with ion energies up to several hundreds of electron volts. The new components have been tested and characterized, and the experimental procedures have been adapted. An important aspect of cluster investigations is the manipulation of trapped ions by application of appropriate excitation fields. For the ICR trap, a vector representation model has been developed for quick analysis of radial excitation fields, applied to the quarter-segmented ring electrode of an ICR trap. Its application has been demonstrated for asymmetric radial quadrupolar excitation of stored cluster ions, confirming the observation of unintended ion ejection from the trap. Investigation of multiply negatively charged metal clusters at ClusterTrap has been continued. By the "electron-bath" technique, i.e. simultaneous storage of cluster mono-anions and electrons in the ICR trap, high charge states are produced up to a limit which arises from restrictions for ion trapping. A modification of the electron bath, which bypasses this limit, has been introduced and demonstrated by the first-time production and detection of aluminum cluster anions carrying five excess electrons (penta-anions). Results of the penta-anion production as a function of the trapping voltage relate to the Coulomb potentials of the cluster anions involved, in agreement with previous findings. The observed poly-anionic clusters are meta-stable and their abundance as a function of the cluster size is determined by their lifetimes. Observed poly-anion abundances are described by a thermionic-emission approach, by means of the Richardson-Dushman formula. The height of the Coulomb potential in the formula is decreased to match experimental data, thus accounting for electron tunneling. Poly-anions are observed only above a minimum cluster size, the appearance size. To determine this limit from experimental results, a new data evaluation method has been introduced, which considers the poly-anion lifetimes and respective abundances of a range of cluster sizes. As a result, the experimental appearance size is larger than the smallest poly-anionic cluster observed, in contrast to previous approaches.
In aged humans, stroke is a major cause of disability for which no neuroprotective measures are available. In animal studies of focal ischemia, short-term hypothermia often reduces infarct size. Nevertheless, efficient neuroprotection requires long-term, regulated lowering of whole-body temperature. Previously, it is reported that post-stroke exposure to hydrogen sulfide (H2S) effectively lowers whole-body temperature and confers neuroprotection in aged animals. Here we report for the first time that the animals exposed to H2S the normal sleep–wake oscillations are replaced by a low-amplitude EEG dominated by a 4-Hz rhythmicactivity, reminiscent of EEG recordings in hibernating animals. In the present study using magnetic resonance imaging, reverse transcriptase polymerase chain reaction, western blotting and immunofluorescence, we characterized the central nervous system response to H2S -induced hypothermia and report, that annexin A1, a major constituent of peripheral leukocytes that is upregulated after stroke, was consistently downregulated in polymorphonuclear cells in the peri-lesional cortex of post-ischemic, aged rat brain after 48 hours of hypothermia induced by exposure to H2S. This might be due to the reduced kinetics of recruitment, adherence and infiltration of PMN cells by H2S -induced hypothermia. Our findings further suggest that, in contrast to monotherapies that have thus far uniformly failed in clinical practice, prolonged hypothermia has pleiotropic effects on brain physiology that may be necessary for effective protection of the brain after stroke.
Thiol or sulfhydryl groups are highly reactive functional groups in cellular systems. Molecules carrying thiol groups are mostly derivatives of the amino acid cysteine and are grouped as low molecular weight (LMW)-thiols: coenzyme A (CoA), glutathione (GSH) or bacillithiol (BSH). LMW-thiols can help in the maintenance of the reduced cellular environment as so called redox-buffers. Additionally, they act as co-factors in enzyme reactions or help in the detoxification of reactive oxygen or nitrogen species, electrophilic compounds or thiophilic metalloids (arsenite, tellurite). In proteins from different organisms cysteine is underrepresented compared to other amino acids, but still overtakes diverse roles. It is an important determinant in the tertiary and quaternary structure of proteins. The nucleophilic character of the thiol or thiolate group, respectively, makes cysteine the catalytically active amino acids of different enzymes. As a precursor cysteine participates in the formation of Fe-S clusters and coordinates different co-factors like heme, iron or zinc. The main goal of this study was the investigation of the different cellular thiol pools, now defined as the thiolome. The thiolome is the entity of the cellular thiol pools, i.e. LMW-thiols and protein thiols, and the dynamics between these pools. In Bacillus subtilis and Staphylococcus aureus mixed disulfides between protein thiols and free LMW-thiols, so called S-thiolations, were identified in different proteins in response to the thiol specific reagent diamide. Some of these S-thiolations were located at catalytically active cysteine residues. Subsequent analysis of metabolites supports this: the S-thiolation of the cobalamine-independent methionine-synthase MetE led to a decrease of the cellular methionine content. Additionally, the conversion of threonine to different branched-chain amino acids (BCAAs) was disrupted by the S-thiolation of the branched-chain amino acid aminotransferase YwaA, thereby probably inducing the synthesis of ppGpp, the alarmon of the stringent response. In addition to the identification of S-thiolations a technique was established which allowed the discrimination between intra- and intermolecular disulfides. The non-reducing/ reducing diagonal gel electrophoresis was applied to B. subtilis and S. aureus and confirmed known existing disulfide bonds, e.g. in alkyl hydroperoxide reductase AhpC or the thiol peroxidase Tpx. In response to diamide an increase of specific disulfide bonds in different proteins was observed. The analysis of the LMW-thiol content by an HPLC-approach allowed the observation of the dynamics of the thiolome. In response to diamide the reduced LMW-thiol content decreased by 75%, reduced protein thiols by 60%. Collaborations with other working groups allowed the identification of BSH in this approach. Additionally, an unknown thiol was found that is likely a derivative of BSH. Screening of the LMW-thiol content of different S. aureus-strains under various growth conditions revealed that strains 8325-4 and SH1000 lack BSH. The lack of BSH was attributed to an 8 bp-duplication in the bshC-gene that encodes the last enzyme of the BSH-synthesis. BSH-production was restored by transducing plasmid-borne functional BshC from strain Newman into strains 8325-4 and SH1000. The reconstitution of the BSH-synthesis aided in the resistance to the antibiotic fosfomycin but did not increase the resistance to different oxidants (diamide, sodium hypochlorite, hydrogen peroxide). The production of BSH had also positive effects on the survival of S. aureus inside human bronchial epithelial cells and murine macrophages in phagocytosis assays. Additionally, a GSH-uptake was observed into S. aureus which has before been known as a GSH-free bacterium. Taken together, this thesis provides the first insights into both, the LMW-thiol- and protein thiol pool of low GC, Gram-positive bacteria under different conditions. A plethora of different methodologies was used to describe the thiolome. The bacterial thiolome is a sophisticated system which is tightly regulated, but also flexible enough to not rely on determined molecules like BSH. The influences of the thiolome are not restricted to its own system and regulation, but also affect different branches of cellular physiology like the metabolism of BCAAs.
In the framework of the current work has been the plasma initiated and surface catalysed species conversion studied in low pressure and atmospheric plasmas. The aim of the work is to improve the understanding of the internal processes in order to increase the energy efficiency as well as the selectivity of the reaction products of future plasma devices. Beside many technical applications of plasmas, air purification shows great potential. Over the last decades, plasma based pollution control has proofed its ability to remove harmful contaminants or annoying odours from an air stream. However, the energy efficiency and the selectivity of the products are a remaining challenge.
Motivated by these issues, a multi stage packed-bed reactor has been used to remove admixed ethylene and toluene from an air stream. It has been found that the maximum toluene destruction has been 60%, whereas ethylene has been nearly completely removed. The specific energy β has been between 120 and 1600 JL-1. Fourier Transform Infrared spectroscopy, FTIR spectroscopy, has been used to identify and quantify the species H2O, CO2, CO, O3, HNO3, HCN, CH2O, CH2O2, N2O and NO2. However, none of these experiments led to the detection of NO.
The embedment of packing material into a plasma volume leads to increased surface effects. In order to study them, the inner side of a tube reactor, made of Pyrex, served as the surface under study and has been exposed to a rf plasma for 1h. The surface effects of the plasma treatment have been investigated indirectly by studying the oxidation of NO into NO2. After the plasma exposure, the reactor has been evacuated and filled with a gas mixture of 1% NO in N2 / Ar. Both species have been measured using quantum cascade laser absorption spectroscopy, QCLAS. It has been found that, using oxygen containing plasmas, the NO concentration decreased whereas the NO2 concentration increased. Therefore, oxygen containing plasmas are able to deposit oxygen on the surface. The filling with NO leads to the oxidation via the Eley-Rideal mechanism. A simplified model calculation supports these assumptions.
For a more comfortable application of the QCLAS, a compact multi channel spectrometer has been developed, TRIPLE Q. It combines the high time resolution with the possibility to measure the concentration of at least three infrared active species simultaneously. Due to the high time resolution, a huge number of spectra have to be analysed. In order to calculate absolute number densities, an algorithm has been developed which automatically treats typical phenomena like pulse jitter, rapid passage effect or variations of the intensity of the laser pulses.
The gas temperature is an important parameter in plasma physics. Using the TRIPLE Q system, the gas temperature has been determined for pulsed dc plasmas. For this case, NO has been used as a probe gas. From the spectra, the temperature has been calculated using the line ratio method. The relative intensity of the absorption structures of NO at 1900.5cm-1 and 1900.08cm-1 depend on the temperature. Therefore, the ratio has been used to calculate the gas temperature with a time resolution in the μs range.
Vibrationally excited nitrogen can be an energy reservoir that plays an important role in plasma chemistry. In N2 / N2O plasmas, vibrationally excited N2 can undergo relaxation via a resonant vibration vibration coupling between vibrationally excited N2 and N2O. Due to such an efficient energy transfer, the method allows one to study the relaxation of vibrationally excited N2. Using this method, molecules, which are not infrared active, can be monitored. This approach has extended the field of scientific and commercial applications of the QCLAS.
The leading hypothesis of why organisms age is the “Free Radical Theory of Aging”, which states that the accumulation of reactive oxygen species (ROS), such as superoxide (O2•-) and hydrogen peroxide (H2O2), causes protein, lipid and DNA damage and leads to the observed age-related decline of cells and tissues. A major obstacle in analyzing the role of oxidative stress in aging organisms is the inability to precisely localize and quantify the oxidants, to identify proteins and pathways that might be affected, and ultimately, to correlate changes in oxidant levels with the lifespan of the organism. To directly monitor the onset and extent of oxidative stress during the lifespan of Caenorhabditis elegans, we utilized the fluorescent H2O2 sensor protein HyPer, which enabled us to quantify endogenous peroxide levels in different tissues of living animals in real time. We made the surprising observation that wildtype C. elegans is exposed to very high peroxide levels during development. Peroxide levels drop rapidly as the animals mature, and low peroxide levels then prevail throughout the reproductive age, after which an age-accompanying increase of peroxide level is observed. These results were in excellent agreement with findings obtained by using the highly quantitative redox proteomic technique OxICAT, which monitors the oxidation status of redox-sensitive proteins as read-out for onset, localization, and protein targets of oxidative stress. By using OxICAT, we detected increased protein thiol oxidation during the development of C. elegans and in aging animals. Many processes in C. elegans might potentially contribute to the elevated peroxide levels observed during development, including cuticle formation, apoptosis, proliferation, gametogenesis, or ROS signaling. The finding that all investigated C. elegans mutants regardless of their lifespan are exposed to high developmental peroxide levels argues for ROS accumulation to be a universal and necessary event. Yet, recovery from the early oxidative boost might determine the subsequent adult lifespan, as we found that long-lived daf-2 mutants transition faster to reducing conditions than short-lived daf-16 mutants, which retain higher peroxide levels throughout their mature life. These results suggest that changes in the cellular oxidant homeostasis, encountered at a very early stage in life, might determine subsequent redox levels and potentially the lifespan of organisms. Manipulation of developmental oxidant levels using glucose restriction or a short bolus of superoxide caused a disruption in developmental growth, a delay in reproduction, and a shortened lifespan. These results suggest that developmental oxidant levels are fine-tuned and optimized. Future experiments are aimed to investigate the sources of developmental hydrogen peroxide, and to elucidate whether active down-regulation of antioxidant enzymes during the larval period might foster peroxide accumulation. Preliminary results indicate that this might indeed be the case for peroxiredoxin 2, whose expression was significantly lower during development than at later stages in life. Finally, we investigated whether the observed variances in the developmental peroxide levels of individual worms within a synchronized wildtype population might be responsible for the observed significant variances in lifespan, and hence could serve as a predictor for adult lifespan. Preliminary results revealed that neither too low nor too high peroxide levels during development are beneficial for the lifespan of wildtype worms, suggesting that ROS level during development might be optimized for maximized lifespan. Future experiments aim to reveal the processes that are affected by ROS and which might influence the individual’s lifespan early in life.
The widespread use of natural and synthetic estrogens or chemicals with estrogenic activities is causing an increasing accumulation of estrogenic compounds in the environment. Already at very low concentrations these estrogenics can severely affect the wildlife, particularly in an aquatic environment. For these reasons measuring devices for detecting estrogen contaminations are in great demand. The majority of the analytical methods and bioassays on the market so far, lack semi-online adaptability, and usually cannot be used for automatic and continuous determination. Therefore, we have embarked on the development of new systems, which are able to fulfil those demands. The EstraMonitor combines recombinant A. adeninivorans G1212/YRC102-hERa-phyK yeast cells as the microbial component with an amperometric detection method to analyze estrogenic contaminations. A. adeninivorans G1212/YRC102-hERa-phyK was constructed by Kaiser et al. (2010). These cells were engineered to co-express the human estrogen receptor (hERa) gene and the inducible phytase (phyK, derived from Klebsiella sp. ASR1) reporter gene under control of a promoter with estrogen response elements (EREs). In the presence of estrogenic substances, such as 17ß -estradiol (E2), the phyK gene is expressed and recombinant phytase is secreted into the media. The level of phytase is quantified by amperometric detection using substrate p-aminophenyl phosphate (p-APP). Phytase dephosphorylates p-aminophenyl phosphate (p-APP) into an intermediate product p-aminophenol (p-AP). p-AP is electroactive and oxidized at the electrode. This generates electrons and produces a current which is proportional to the level of phytase activity. Since phytase activity is directly correlated to the E2 concentration, the estrogenic activity can thus be calculated from the current measured. The microbial component of the EstraMonitor, the non-immobilized A. adeninivorans G1212/YRC102-hERa-phyK, works well with the amperometric method in a quantitative manner. The optimal applied potential determined for amperometric measurements was 150 mV and provided a low background signal for the amperometric detection. The half maximal effective concentration (EC50) and limit of detection (LoD) values for E2 obtained from amperometric measurements with the EstraMonitor were 69.9 ng L-1 and 44.5 ng L-1, respectively. The measuring procedure of the EstraMonitor system including incubation of A. adeninivorans G1212/YRC102-hERa-phyK cells with E2, subsequently incubation with electrochemical substrate (p-APP), and signal recordation is completed within only 4 h and 10 min. Out of this total time, amperometric detection including substrate incubation and signals recordation takes only 10 min out of total time. The use of immobilized cells for a microbial biosensor is an essential advantage of the EstraMonitor system because it allows easy-handiness next to long-term stability and reusability. Immobilized A. adeninivorans G1212/YRC102-hERa-phyK cells revealed excellent properties which make them very suitable for semi-online, automatic and continuous monitoring. They were stable up to 30 days when stored at 4 °C. Furthermore, they could be reused up to 15 times. The EC50 and LoD values achieved for E2 using immobilized cells in combination with amperometric detection were 20.9 and 8.3 ng L-1, respectively. Furthermore, this application also removes the need to separate cells by centrifugation, to sterilize the samples as well as to cultivate repeatly. Additionally, both immobilized and non-immobilized A. adeninivorans G1212/YRC102-hERa-phyK cells remain fully functional in a wide range of untreated wastewater samples and in environments containing up to 5% NaCl. To enhance the sensitivity and reduce the time for estrogenic determination, an alternative A. adeninivorans G1214/YRC103-hERa-phyK strain was developed. This strain can produce a detectable amount of phytase within 2 h after induction with E2. It offers an improved microbial component in terms of sensitivity and time-effectiveness. In addition, to reduce the cost for estrogenic detection an alternative substrate, ascorbic acid 2-phosphate (AA2P), was tested. AA2P, which is both cheap and widely available, performed better than p-APP. The EC50 and LoD values for E2 obtained with AA2P were 15.69 and 0.92 ng L-1 versus 20.09 and 8.3 ng L-1 when examined with p-APP, respectively. Taken together, the EstraMonitor is an automated system with respect to sample cycling, sample measuring and calibration supplemented with an alarm function. This system makes it possible to control estrogenic activity semi-online, automatically and continuously. These are advantages of the EstraMonitor compared to other estrogenic detection systems. It can thus be concluded that, the EstraMonitor is a powerful and feasible semi-online device for monitoring estrogenic activity especially adapted for the use in sewage treatment plants.
Non-thermal atmospheric pressure plasma has recently been shown to have broad application potential for medical as well as industrial purposes. Improved wound healing and tissue decontamination have been described as consequences of non- thermal plasma treatment. However, thus far the underlying molecular mechanisms in human tissues have only been partially characterized. In this work a two-dimensional difference in-gel electrophoresis (2D-DIGE) approach was used and an analysis-workflow to study the response of human cells to atmospheric pressure non-thermal plasma was established. Human S9 bronchial epithelial cells were used as a model for airway epithelial cells. They were treated with atmospheric pressure plasma jet (APPJ) for different periods of time. Subsequently, time-resolved comparative proteome analysis was used to study the complex cellular adaptation reactions after a 120 sec plasma treatment, which accelerated wound healing in a clinically relevant model. The results indicate, that intracellular oxidative stress due to the non-thermal plasma treatment either leads to cell death or to proliferation. The oxidative stress response, mediated by Nrf2, appears to play a pivotal role in molecular signalling and might be a key pathway determining the fate of stressed cells. This thesis demonstrates changes in Nrf2-expression after non-thermal plasma treatment. Furthermore, potential protein biomarker candidates for evaluation of oxidative stress after non-thermal plasma treatment were identified. Finally, it is shown, that the cytosolic concentrations of IL-1beta and IL-33 were decreased following non-thermal plasma treatment. Thus, modulation of innate immune response by non-thermal plasma treatment of epithelial cells (ENTplas treatment) is concluded.
The worldwide distribution and prevalence of melioidosis, an infectious disease caused by the soil-dwelling Gram-negative bacterium Burkholderia pseudomallei, is unknown. In Vietnam, sporadic cases of melioidosis have been reported for decades, but clinical and epidemiological data for the indigenous population are still scarce. In this study, we reviewed clinical and demographic data of patients with culture-proven melioidosis diagnosed at a single large referral hospital in Hanoi between November 1997 and December 2005. The clinical manifestations of melioidosis with fatal septicaemia as the most common presentation, a high rate of underlying diseases and a peak of cases admitted during the wet season were similar to studies from other endemic areas. The geographical origin of melioidosis patients shows that melioidosis exists in at least 18 northern provinces. The characterization of clinical B. pseudomallei strains by multilocus sequence typing identified 17 different sequence types (STs), ten of which have (as yet) not been found outside Vietnam. Several of these STs presumably were generated through recent evolutionary events in this rapidly diversifying bacterial species, and thus restricted geographic distribution may be a consequence of limited time passed since emergence. In order to define the distribution of the bacterium in the environment, our study also aimed to develop a more sensitive culture method for the detection of B. pseudomallei from soil samples in endemic areas compared to the currently used culture method based on soil dispersion in water. Our newly developed protocol involving soil dispersion in a polyethylene glycol and sodium deoxycholate solution increased the yield of viable B. pseudomallei from soil samples. Comparative testing of soil samples from Northeast Thailand covering a wide range of B. pseudomallei concentrations demonstrated a significantly higher recovery (p < 0.0001) of B. pseudomallei colony forming units by the new method compared to the conventional method. Our data indicate that using the detergents polyethylene glycol and sodium deoxycholate not only results in a higher recovery of viable B. pseudomallei, but also results in a shift in the bacterial species recovered from soil samples. Molecular methods based on direct bacterial nucleic acid extraction from environmental samples and subsequent amplification have the potential to overcome many restrictions of traditional microbiological approaches. Moreover, culture-dependent methods require special expertise in recognizing B. pseudomallei colony morphologies. Thus, a highly sensitive culture-independent DNA-based method that allows direct quantification of B. pseudomallei from soil is needed, particularly in diagnostic laboratories outside endemic areas. We therefore aimed to establish a protocol for B. pseudomallei soil DNA isolation, purification and quantification by qPCR targeting a type three secretion system 1 single copy gene. This assay was validated using 40 soil samples from Northeast Thailand that underwent parallel bacteriological culture. All 26 samples that were B. pseudomallei-positive by direct culture were B. pseudomallei qPCR-positive, with a median of 1.84 x 104 genome equivalents (range 3.65 x 102 to 7.85 x 105) per gram of soil. This was 10.6 fold (geometric mean; range 1.1 to 151.3) higher than the bacterial count as defined by culture. Moreover, the qPCR detected B. pseudomallei in seven samples (median 36.9 genome equivalents per g soil; range 9.4 to 47.3), which were negative on direct culture. These seven positives were reproduced using a nested PCR targeting a second, independent B. pseudomallei-specific sequence. Two samples were direct culture and qPCR negative but nested PCR positive. Five samples were negative by both PCR methods and culture. In conclusion, this is the first report on a series of cases describing clinical and epidemiological features of melioidosis and corresponding Burkholderia pseudomallei strains from northern Vietnam. Moreover, our newly developed culture-based and PCR-based methods provide highly specific and sensitive tools for the quantitative environmental surveillance of B. pseudomallei.
Understanding the interaction between climate variability and ice sheet behavior is critical due to scenarios of future climate warming and the consequent contribution of Greenland ice sheet melting to sea-level rise and its potential to influence thermohaline circulation. This thesis investigates the role of ocean forcing by the West Greenland Current (WGC) on the dynamics of West Greenland ice sheet behavior, with focus on Jakobshavn Isbræ, in the Disko Bugt area of central West Greenland. High-resolution sediment cores, obtained during a cruise of the RV ‘Maria S. Merian’ in 2007, provide a long-term Holocene perspective on climate variability off West Greenland. These records cover the last 8000 years with increasing resolution through to periods of historical and instrumental data series. Paleoenvironmental reconstructions, based on the calcareous and agglutinated benthic foraminiferal assemblage, reveal significant variations in the water mass properties (e.g. temperature and salinity) of the WGC. From 8 to 6 cal. ka BP, a relatively warm WGC enhances meltwater production (ice retreat) in Disko Bugt. Holocene ‘thermal optimum-like’ conditions prevailed from 5.5 to 3.5 cal. ka BP, associated with minimum ice sheet extent in eastern Disko Bugt. Long-term cooling of oceanographic conditions is recognized from c. 3.5 cal. ka BP towards the present day. Superimposed on this millennial scale cooling trend, centennial scale variability within the WGC is reconstructed: i) the 2.7 cal. ka BP ‘cooling event’; ii) the Roman Warm Period; iii) the Medieval Climate Anomaly; and iv) the Little Ice Age. Over the past 100 years, oceanographic conditions remain relatively cool and multidecadal variability in the WGC’s ocean temperatures show close correlation with the ice marg in position of Jakobshavn Isbræ and phases of the Atlantic Multi-decadal Oscillation (AMO). Cold (warm) phases correlate with stabilization/re-advance (retreat) of Jakobshavn Isbræ and a negative (high) index of the AMO. It has been demonstrated that variations in ocean temperature are an important factor that influence ice sheet behavior on a range of times scales, underlining the close coupling of ice-ocean interactions during the Holocene. Warmer ocean temperatures influence the stability of marine terminating ice sheets and glaciers, causing basal melting and glacier acceleration, whereas ocean cooling supports stabilization and advance of ice margin.
Dilated Cardiomyopathy is a chronic myocardial disease characterized by progressive depression of contractile function and ventricular dilatation. It is the leading cause of heart failure and the most common reason for heart transplantation. Besides genetic causes, viral infection and autoimmune response are considered to play a major role in the etiology of the disease. Among different viruses that cause the disease, Coxsackievirus B3 (CVB3) is predominantly associated with the development and progression of the disease. Moreover, Coxsackievirus induced myocarditis in the mouse mimics human myocarditis and dilated cardiomyopathy. In the murine model, the disease progresses over a period of 90 days from acute myocarditis to chronic myocarditis and further develops into dilated cardiomyopathy and congestive heart failure. Though much is known about the progression of the disease, the molecular events occurring after infection with CVB3 are not completely understood. In the current study, comparative proteomic analysis of A.BY/SnJ mouse hearts 84 days post infection (84 d p.i.) with CVB3 and age-matched non-infected mouse hearts was performed. 2D-DIGE and gel-free LC-MS/MS were used to characterize the changes occurring at the molecular level and Western Blot analysis as well as immunohistochemical staining was carried out for validation of results. A total of 101 distinct proteins were identified as displaying dilated cardiomyopathy-associated changes in A.BY/SnJ mouse hearts 84 d p.i. compared to age matched controls. Comprehensive analysis by both DIGE and gel-free proteomics revealed proteins related to lipid metabolism (18%), carbohydrate metabolism (14%), cell morphogenesis (14%) and respiratory electron transport chain (9%) to display significantly altered levels in diseased mouse hearts. The significant increase in extracellular matrix proteins observed in mouse hearts 84 d p.i. indicated extensive fibrosis. On the other hand, proteins related to energy metabolism were identified at lower levels in infected mouse hearts than in controls. These proteomics data and the decrease in activities measured for complexes I-IV of the respiratory electron transport chain in A.BY/SnJ mouse hearts 84 d p.i compared to age matched controls, indicate a diminished energy supply in the dilated hearts of CVB3 infected mice. Furthermore, proteins associated with muscle contraction were identified at lower levels in mouse hearts 84 d p.i. compared to age matched controls indicating compromised myocardial contractility due to virus induced dilated cardiomyopathy. While extracellular matrix proteins and contractile proteins were identified in the DIGE analysis, proteins of lipid metabolism which are mostly mitochondrial in origin and have a pI > 7 were identified by gel-free proteomics indicating the advantages of both methods. Gel based analysis also aided in the identification of protein isoforms/ species which allows conclusions on post translational modifications and protein processing. Thus, the current study also identified infection related changes in the phosphorylation of selected proteins. Phosphospecific staining of the gels demonstrated increased phosphorylation of myosin regulatory light chain - ventricular isoform, actin - aortic smooth muscle isoform, heat shock protein 90B, and heat shock protein beta-1 in infected mouse hearts. Extensive degradation of proteins was not observed in the dilated heart. As described earlier, virus induced dilated cardiomyopathy develops over a period of 90 days in the murine model during which the mice also grow and undergo aging. Since aging is one of the factors influencing the susceptibility of animals to disease, age dependent changes in the proteome of mouse hearts were also studied by comparing 4 months old (84d) A.BY/SnJ mice with 1 month old mice as controls. Complementary analyses by 2D-DIGE and gel-free LC-MS/MS analysis revealed 96 distinct proteins displaying age associated differences in intensity. These proteins are related to lipid metabolism (19%), protein transport (17%) and electron transport chain (12%). Mitochondrial proteins such as carnitine-o-palmitoyltranferase 1, carnitine-o-palmitoyltranferase 2, and carnitine-O-acetyltransferase involved in lipid metabolism and transport were identified at significantly higher levels indicating higher energy demand in 4 months old mice compared to controls. This conclusion is complemented by observation of decreases in the levels of respiratory electron transport chain proteins especially of subunits of ATP synthase as a member of complex V. Furthermore, an increase in intracellular transport proteins was also observed in 4 months old mouse hearts compared to one month old controls. An increase in the level of vesicular transport proteins likely constitutes a secondary effect leading to endoplasmic reticulum associated protein degradation. In the two studies described above, altered mitochondrial functioning and thereby decreased energy/ATP production was very prominent indicating the role of mitochondria in health and disease. The exchange of ADP/ATP across the mitochondrial membrane is carried out by the carrier protein adenine nucleotide translocase1 (ANT1). To improve understanding of the influence of ANT1 in the heart, comparative proteomic analysis using gel-free LC-MS/MS was performed with hearts of 3 months old rats over-expressing ANT1 using hearts from age-matched wild type animals as controls. A total of four hundred and thirty three proteins were identified with at least two peptides, of which eighty seven proteins displayed small but significant (p<0.05) changes in intensity. Proteins related to integrin linked kinase signalling and myocardial contraction displayed increased levels whereas proteins of the mitochondrial respiratory electron transport chain displayed decreased levels in ANT1 overexpressing hearts compared to wild type animals. Oxyblot analysis performed to study changes in the protein oxidation did not reveal any significant difference in the oxidative state of the proteins between the wild type and transgenic animals. To understand the influence of ANT1 overexpression in virus induced dilated cardiomyopathy, comparative proteomic analyses was performed for the mitochondrial fractions from the hearts of 8 months old rats of the wild type and ANT1 transgenic animals infected with CVB3. Of a total of 370 identified proteins, 83 proteins displayed altered levels in ANT1 overexpressing animals compared to controls. Proteins related to mitochondrial electron transport chain, fatty acid metabolism, contractility and cell structure displayed decreased levels in the infected transgenic animals compared to controls indicating decreased energy metabolism and myocardial contractility besides compromised cell structure. Besides viral causes of dilated cardiomyopathy, autoimmunity also plays a major role in the development of myocarditis and dilated cardiomyopathy. Therefore proteomic analyses of experimental models of autoimmune myocarditis generated by active immunization of rats with peptides of FcγIIa receptor -CEPPWIQVLKEDTVTL (peptide 1) designated as FcR animals and CRCRMEETGISEPI (peptide 2) designated as FcR2 animals- was performed. Of the 303 proteins identified with at least two peptides by gel-free LC-MS/MS analysis. 43 proteins displayed intensities greater than 1.2 fold in FcR rat hearts and 49 proteins displayed intensities greater than 1.2 fold in FcR2 rat hearts compared to animals injected with KLH adjuvant treated as controls. The majority of the alterations (>70%) were observed in both autoimmune models. Thus, immunization leading to an induction of the acute phase response signalling was observed in both experimental setups. Furthermore, the increased amount of proteins such as lumican or procollagen alpha 1, type 1 indicated the presence of fibrosis after immunization independent of the peptide used. In summary, using proteomics the current thesis addresses the changes in protein profiles of two models of dilated cardiomyopathy, namely, virus induced dilated cardiomyopathy and autoimmunity induced dilated cardiomyopathy in mouse and rat models of disease. 2D-DIGE and gel-free LC-MS/MS analysis are complementary techniques which provided a comprehensive view of the changes in the protein profile of hearts of the different animal models. Altered mitochondrial function resulting in decreased energy metabolism and compromised myocardial contractility were prominent in viral models of cardiomyopathy whereas intense acute phase response signalling was observed as a characteristic feature of autoimmune dilated cardiomyopathy. Altered mitochondrial function was also prominent in age associated changes in the heart of A.BY/SnJ mice indicating the role and influence of mitochondria in health and in disease.
The general stress response comprises approximately 200 genes and is driven by the alternative sigma factor SigB. Besides the process of sporulation with approximately 500 involved gene products under initial control of Spo0A are the two most significant and extensive cellular responses that can be observed in B. subtilis. The general stress response provides vegetative growing as well as non-growing and non-sporulating cells with a comprehensive cross-protective and preventive multiple stress resistance to various hostile environmental conditions. In contrast, the endospore is the most resistant but also dormant cell type produced by B. subtilis. The scope of this study was the identification of regulatory cascades driven by the general stress response sigma factor SigB to further elucidate the structure and function of the general stress regulon itself and to uncover potential intersections between the SigB response and other major developmental programs in the regulatory network of B. subtilis. It could be shown that the general stress regulon member yqgZ encodes a functional paralogue of Spx, the global regulator of the diamide stress regulon in B. subtilis. Global transcriptome and proteome studies led to the characterization of an YqgZ sub-regulon consisting of 53 positively and 18 negatively regulated genes. Due to its stringent SigB-dependent expression as well as its concerted action with SigB in regulation of its target genes YqgZ was renamed to MgsR which stands for “modulator of the general stress response”. Activity control of MgsR is stringently controlled at multiple levels. In addition to induction by SigB these mechanisms include (i) a positive autoregulatory loop of MgsR on the transcription level of its own structural gene, (ii) a post-translational redox-sensitive activation step by the formation of an intramolecular disulfide-bond within a conserved -CXXC-motif and (iii) rapid proteolytic degradation of MgsR by the ClpCP and ClpXP proteases, resul ting in extremely short in vivo half-lifes below 6 minutes. It was demonstrated that the activation of SigB is a prerequisite but not sufficient for a full expression of all general stress genes and that the SigB-dependent expression of MgsR provides the opportunity for additional redox-sensitive signal-reception, -processing and -integration beyond the primary decision of SigB activation. Our results describe a regulatory cascade integrating secondary oxidative stress signals into a SigB mediated regulatory cascade that is aimed at a precise fine tuning of target gene expression whose products are necessary for proper management of oxidative stress. Although primary oxidative stress stimuli do not typically induce SigB, our observation of redox-sensitive control by MgsR and several other reports that pointed at the implication of the general stress proteins in oxidative stress management led to the proposal that secondary oxidative stress may be a common component of multip le severe physical stress stimuli. This assumption could be supported by the results of a comprehensive phenotype screening of 94 mutants in single general stress genes upon treatment with hydrogen peroxide and the superoxide generating agent paraquat. A substantial amount of 62 mutants (66%) displayed significantly decreased survival rates in response to oxidative stress. The information gained by this phenotypic screening analysis provides a valuable basis for more directed assays to elucidate the biochemical functions of many so far uncharacterized general stress proteins and demonstrates that the SigB response and the regulatory fine tuning by MgsR plays a pivotal role in protection from secondary oxidative stress. Furthermore, it has been intensively discussed throughout the literature of the last years that the general stress response and the process of sporulation may represent mutually exclusive survival strategies of a non-growing B. subtilis cell, but the molecular basis for this assumption was missing until recently. By the identification of a functional SigB-type promoter (PsigB) adjacent to the spo0E, this gene was newly assigned to the general stress regulon. The spo0E gene encodes a phosphatase that specifically inactivates the master regulator of sporulation Spo0A~P by dephosphorylation. The SigB dependent induction of spo0E causes a block of sporulation specific transcription and produces a sporulation deficient phenotype. This effect was overcome by a deletion of the spo0E-SigB promoter, thus clearly addresses SigB activity. This regulatory mechanism is the first example for an integration of SigB inducing stimuli into the decision making process of sporulation initiation that provides a link to interconnect these two dominant and very likely mutually exclusive responses in the regulatory network of B. subtilis. The data presented here provide deeper insights into the structure and function of the general stress regulon in stress management.
Beams of ions and electrons are a source of free energy which can be transferred to waves via an instability. Beams exist in almost all plasma environments, but their instabilities are particularly important for the dynamics of space plasmas. In the absence of collisions, the instability drives waves to large amplitudes and forms nonlinear structures such as solitary waves. The electric fields in these waves can scatter particles in the background plasma, or disrupt currents. Both of these effects are important for the overall dynamics of the plasma. In this thesis, both electron and ion beam plasma instabilities have been investigated in the linear plasma device VINETA and using a Particle-in-Cell simulation. The electron beam instability has been demonstrated by previous authors to be a useful diagnostic for the plasma density. The spatial resolution of previous results was confirmed at a few millimetres, and a temporal resolution of 1ms was shown for the first time. An ion beam was generated with a double plasma discharge. Compared to space, this environment and indeed most laboratory plasmas have considerably higher collisionality and a limited spatial extent which introduces gradients in the plasma. Gradients perpendicular to the beam propagation direction are linked to a decrease of both the wavelength and amplitude of the instability. It was observed in both experiment and simulation that gradients in sheaths at the boundaries of the plasma not only affect the time averaged plasma parameters, but also excite instabilities. Fluctuations within the sheath spread the beam in velocity space, effectively increasing its temperature. Warmer beams require a higher drift velocity to excite an instability. This was also confirmed by experimental and numerical results. Collisions are shown to be the dominant damping force for the electron beam instability. For ions, collisions play an important role in the simulation, but appear to be overshadowed by Landau damping from impurities in the experiment. When boundary conditions are removed from the simulation, wave amplitudes increase and nonlinear effects become important. Saturation by particle trapping and coalescence of phase space holes is observed, which could eventually lead to the solitary waves as they are observed in space plasmas.