53 research outputs found

    Crenarchaeal Biofilm Formation under Extreme Conditions

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    Background: Biofilm formation has been studied in much detail for a variety of bacterial species, as it plays a major role in the pathogenicity of bacteria. However, only limited information is available for the development of archaeal communities that are frequently found in many natural environments. Methodology: We have analyzed biofilm formation in three closely related hyperthermophilic crenarchaeotes: Sulfolobus acidocaldarius, S. solfataricus and S. tokodaii. We established a microtitre plate assay adapted to high temperatures to determine how pH and temperature influence biofilm formation in these organisms. Biofilm analysis by confocal laser scanning microscopy demonstrated that the three strains form very different communities ranging from simple carpet-like structures in S. solfataricus to high density tower-like structures in S. acidocaldarius in static systems. Lectin staining indicated that all three strains produced extracellular polysaccharides containing glucose, galactose, mannose and N-acetylglucosamine once biofilm formation was initiated. While flagella mutants had no phenotype in two days old static biofilms of S. solfataricus, a UV-induced pili deletion mutant showed decreased attachment of cells. Conclusion: The study gives first insights into formation and development of crenarchaeal biofilms in extrem

    Podoplanin immunopositive lymphatic vessels at the implant interface in a rat model of osteoporotic fractures

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    Insertion of bone substitution materials accelerates healing of osteoporotic fractures. Biodegradable materials are preferred for application in osteoporotic patients to avoid a second surgery for implant replacement. Degraded implant fragments are often absorbed by macrophages that are removed from the fracture side via passage through veins or lymphatic vessels. We investigated if lymphatic vessels occur in osteoporotic bone defects and whether they are regulated by the use of different materials. To address this issue osteoporosis was induced in rats using the classical method of bilateral ovariectomy and additional calcium and vitamin deficient diet. In addition, wedge-shaped defects of 3, 4, or 5 mm were generated in the distal metaphyseal area of femur via osteotomy. The 4 mm defects were subsequently used for implantation studies where bone substitution materials of calcium phosphate cement, composites of collagen and silica, and iron foams with interconnecting pores were inserted. Different materials were partly additionally functionalized by strontium or bisphosphonate whose positive effects in osteoporosis treatment are well known. The lymphatic vessels were identified by immunohistochemistry using an antibody against podoplanin. Podoplanin immunopositive lymphatic vessels were detected in the granulation tissue filling the fracture gap, surrounding the implant and growing into the iron foam through its interconnected pores. Significant more lymphatic capillaries were counted at the implant interface of composite, strontium and bisphosphonate functionalized iron foam. A significant increase was also observed in the number of lymphatics situated in the pores of strontium coated iron foam. In conclusion, our results indicate the occurrence of lymphatic vessels in osteoporotic bone. Our results show that lymphatic vessels are localized at the implant interface and in the fracture gap where they might be involved in the removal of lymphocytes, macrophages, debris and the implants degradation products. Therefore the lymphatic vessels are involved in implant integration and fracture healing

    Reported and recorded sleepiness in obesity and depression

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    Civil war, flight, escape and expulsion are extremely stressful and assert a negative impact on refugees’ mental health. However scientific research about resilience and coping of refugees is scarce. Especially in the recent refugee crisis, calls have been made to consider factors contributing to coping and resilience in this vulnerable population. Therefore, the current research sought to investigate individual differences that could serve as antecedents of coping and contextual factors that might moderate these effects. Specifically, it took into account individual’s self-regulatory differences in terms of regulatory focus (i.e., a promotion focus on nurturance needs, ideals and gains vs. a prevention focus on security needs, oughts and losses). It furthermore explored contextual influences by considering Syrian refugees in Turkey (Sample 1, N = 273) and Germany (Sample 2, N = 169). Compared to Syrian refugees in Turkey, those in Germany had a stronger promotion focus. They also reported more problem-focused and less maladaptive coping, as well as less symptoms. Both promotion and prevention focus were positively related to problem-focused coping. Problem-focused coping, in turn, predicted more symptoms in Turkey but not in Germany. Furthermore, a stronger promotion focus was associated with less symptoms and maladaptive coping was associated with more symptoms in both samples. These results contribute to the coping literature in demonstrating that under certain conditions problem-focused coping can be maladaptive and extend the scarce previous work on self-regulation and coping. Most importantly, they highlight a promotion focus as a clear resilience factor and the role of maladaptive coping in increasing vulnerability. As such, they might inform the design of effective interventions among Syrian refugees and beyond

    Interaction modulation through arrays of clustered methyl-arginine protein modifications

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    Systematic analysis of human arginine methylation identifies two distinct signaling modes;either isolated modifications akin to canonical post-translational modification regulation, or clustered arrays within disordered protein sequence. Hundreds of proteins contain these methyl-arginine arrays and are more prone to accumulate mutations and more tightly expression-regulated than dispersed methylation targets. Arginines within an array in the highly methylated RNA-binding protein synaptotagmin binding cytoplasmic RNA interacting protein (SYNCRIP) were experimentally shown to function in concert, providing a tunable protein interaction interface. Quantitative immunoprecipitation assays defined two distinct cumulative binding mechanisms operating across 18 proximal arginine-glycine (RG) motifs in SYNCRIP. Functional binding to the methyltransferase PRMT1 was promoted by continual arginine stretches, whereas interaction with the methyl-binding protein SMN1 was arginine content-dependent irrespective of linear position within the unstructured region. This study highlights how highly repetitive modifiable amino acid arrays in low structural complexity regions can provide regulatory platforms, with SYNCRIP as an extreme example how arginine methylation leverages these disordered sequences to mediate cellular interactions

    Impact of Serum Cytokine Levels on EEG-Measured Arousal Regulation in Patients with Major Depressive Disorder and Healthy Controls

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    Background: In major depressive disorder (MDD), findings include hyperstable regulation of brain arousal measured by electroencephalography (EEG) vigilance analysis and alterations in serum levels of cytokines. It is also known that cytokines affect sleep-wake regulation. This study investigated the relationship between cytokines and EEG vigilance in participants with MDD and nondepressed controls, and the influence of cytokines on differences in vigilance between the two groups. Methods: In 60 patients with MDD and 129 controls, 15-min resting-state EEG recordings were performed and vigilance was automatically assessed with the VIGALL 2.0 (Vigilance Algorithm Leipzig). Serum levels of the wakefulness-promoting cytokines interleukin (IL)-4, IL-10, IL-13 and somnogenic cytokines tumor necrosis factor-alpha, interferon-gamma and IL-2 were measured prior to the EEG. Results: Summed wakefulness-promoting cytokines, but not somnogenic cytokines, were significantly associated with the time course of EEG vigilance in the MDD group only. In both groups, IL-13 was significantly associated with the course of EEG vigilance. In MDD compared to controls, a hyperstable EEG vigilance regulation was found, significant for group and group x time course interaction. After controlling for wakefulness-promoting cytokines, differences in vigilance regulation between groups remained significant. Conclusions: The present study demonstrated a relationship between wakefulness-promoting cytokines and objectively measured EEG vigilance as an indicator for brain arousal. Altered brain arousal regulation in MDD gives support for future evaluation of vigilance measures as a biomarker in MDD. Since interactions between cytokines and EEG vigilance only moderately differed between the groups and cytokine levels could not explain the group differences in EEG vigilance regulation, cytokines and brain arousal regulation are likely to be associated with MDD in independent ways. (C) 2016 S. Karger AG, Base

    Inflammatory Cytokines in General and Central Obesity and Modulating Effects of Physical Activity

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    Context Chronic systemic inflammation in obesity originates from local immune responses in visceral adipose tissue. However, assessment of a broad range of inflammation-mediating cytokines and their relationship to physical activity and adipometrics has scarcely been reported to date. Objective To characterize the profile of a broad range of pro-and anti-inflammatory cytokines and the impact of physical activity and energy expenditure in individuals with general obesity, central obesity, and non-obese subjects. Design, Setting, and Participants A cross-sectional study comprising 117 obese patients (body mass index (BMI) >= 30) and 83 non-obese community-based volunteers. Main Outcomes Measures Serum levels of interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12, IL-13, granulocyte-macrophage colony-stimulating factor (GM-CSF),interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha were measured. Physical activity and energy expenditure (MET) were assessed with actigraphy. Adipometrics comprised BMI, weight, abdominal-, waist-and hip-circumference, waist to hip ratio (WHR),and waist-to-height-ratio (WHtR). Results General obesity was associated with significantly elevated levels of IL-5, IL-10, IL-12, IL-13, IFN-gamma and TNF-alpha, central obesity with significantly elevated IL-5, IL-10, IL-12, IL-13 and IFN-gamma-levels. In participants with general obesity, levels of IL-4, IL-10 and IL-13 were significantly elevated in participants with low physical activity, even when controlled for BMI which was negatively associated with physical acitivity. Cytokines significantly correlated with adipometrics, particularly in obese participants. Conclusions Results confirm up-regulation of certain pro-and anti-inflammatory cytokines in obesity. In obese subjects, physical activity may lower levels and thus reduce pro-inflammatory effects of cytokines that may link obesity, insulin resistance and diabetes

    Influence of Thoracic Trauma on Fracture Healing in Long Bones—A Retrospective Analysis

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    Purpose: Pre-clinical studies indicate that concomitant thoracic trauma impairs fracture healing of long bones and reduces callus formation. The aim of this study was to investigate whether patients with accompanying chest trauma suffer from delayed fracture healing of long bones in comparison with patients with fractures of two long bones or isolated fractures. Patients and Methods: This is a clinical retrospective study from a level I trauma center. The patients were divided into three groups: (1) thoracic trauma and fracture of a long bone, (2) fractures of two long bones, (3) isolated fracture of a long bone. The fracture consolidation was defined using the radiographic union scale in tibial fractures (RUST). A RUST value of ≥10 six-to-eight months after definitive operative intervention represented complete fracture healing. Results: In the first group 19 (43.2%) fractures did not show full consolidation, in the second group 14 (45.2%) and 13 (41.9%) and in the third group 14 (36.8%). The analysis revealed no statistically significant differences between the groups regarding consolidation of the fractures six-to-eight months after definitive operative intervention (p = 0.84). Conclusions: Unlike previously reported pre-clinical data, this study did not demonstrate a negative effect on fracture consolidation in long bones when accompanied by thoracic trauma. Furthermore, the results demonstrated that concomitant fractures of two long bones does not have a negative effect on fracture consolidation
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