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91.
Florian Capito Romas Skudas Bernd Stanislawski Harald Kolmar 《Biotechnology progress》2013,29(1):265-274
Production of recombinant proteins, e.g. antibodies, requires constant real‐time monitoring to optimize yield and quality attributes and to respond to changing production conditions, such as host cell protein (HCP) titers. To date, this monitoring of mammalian cell culture‐based processes is done using laborious and time consuming enzyme‐linked immunosorbent assays (ELISA), two‐dimensional sodium dodecylsulphate polyacrylamide gel electrophoresis, and chromatography‐based systems. Measurements are usually performed off‐line, requiring regular sample withdrawal associated with increased contamination risk. As information is obtained retrospectively, the reaction time to adapt to process changes is too long, leading to lower yield and higher costs. To address the resulting demand for continuous online‐monitoring systems, we present a feasibility study using attenuated total reflection spectroscopy (ATR) to monitor mAb and HCP levels of NS0 cell culture in situ, taking matrix effects into account. Fifty‐six NS0 cell culture samples were treated with polyelectrolytes for semi‐selective protein precipitation. Additionally, part of the samples was subjected to filtration prior to analysis, to change the background matrix and evaluate effects on chemometric quantification models. General models to quantify HCP and mAb in both filtered and unfiltered matrix showed lower prediction accuracy compared to models designed for a specific matrix. HCP quantification in the range of 2,000–55,000 ng mL?1 using specific models was accurate for most samples, with results within the accepted limit of an ELISA assay. In contrast, mAb prediction was less accurate, predicting mAb in the range of 0.2–1.7 g L?1. As some samples deviated substantially from reference values, further investigations elucidating the suitability of ATR for monitoring are required. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013 相似文献
92.
María J. Barrero Borja Sese Bernd Kuebler Josipa Bilic Stephanie Boue Mercè Martí Juan Carlos Izpisua Belmonte 《Cell reports》2013,3(4):1005-1011
Highlights? Macrohistone variants are regulated during reprogramming and differentiation ? The levels of macrohistone variants modulate the efficiency of reprogramming ? MacroH2A.1 occupies pluripotency and differentiation genes in keratinocytes ? MacroH2A.1 occupancy prevents the gain of H3K4me2 during reprogramming 相似文献
93.
Bernd?Bergander Laurence?ErdurEmail author Bettina?Kallenbach-Dermutz Hans-Christian?Deter 《BioPsychoSocial medicine》2013,7(1):4
Introduction
Patients with chronic pain are found with highly variable clinical presentation and differing physical complaints. They are seen as a heterogenic group. Based on clinical observations, elderly patients seem to differ from younger patients with chronic pain. We examined whether there were systematic differences between young and old pain patients.Methods
As part of a routine evaluation of university hospital care, a newly developed psychosomatic treatment model for chronic somatoform pain disorders was examined. The basis for treatment efficacy was a target-oriented, specific somatic and psychological intervention that included a stable physician-patient relationship. Particular attention was paid to differences in treatment outcome with regard to changes in both physical and psychopathological symptom levels. We hypothesised that younger pain patients had higher psychological burden and benefitted more from our treatment than older pain patients.Results
Overall, 179 inpatients (57.5% women) with chronic pain were examined (age between 16 and 79 years). The group as a whole yielded high scores on the somatisation dimension (SCL-90) and showed a considerable amount of psychopathological symptoms, such as depressive mood and anxiety (HADS) and a great emotional instability (FPI-R). Age differences were only found with regards to patients’ degree of aggression (SCl-90): younger patients showed higher aggressive tendencies than older ones (p< 0.05). The treatment offered helped patients in both age groups especially with regard to reduction of depressive mood (HADS, p< 0.01) and anxiety levels (HADS, p< 0.01). Regression analysis showed different age groups and gender as significant predictors of anxiety reduction under therapy (R2=.108; model: p< 0.01).Discussion and conclusion
Results show that younger chronic pain patients suffer more from a considerable amount of psychological distress than older ones, but our treatment approach was equally effective in both groups. However, age and gender differences, as well as the patient’s baseline level of anxiety influenced the outcome. These factors need to be studied in future research.94.
Hexavalent chromium is a serious and widespread environmental pollutant. Although many bacteria have been identified that can transform highly water-soluble and toxic Cr(VI) to insoluble and relatively non-toxic Cr(III), bacterial bioremediation of Cr(VI) pollution is limited by a number of issues, in particular chromium toxicity to the remediating cells. To address this we sought to develop an immobilized enzymatic system for Cr(VI) remediation. To identify novel Cr(VI) reductase enzymes we first screened cell extracts from an Escherichia coli library of soluble oxidoreductases derived from a range of bacteria, but found that a number of these enzymes can reduce Cr(VI) indirectly, via redox intermediates present in the crude extracts. Instead, activity assays for 15 candidate enzymes purified as His6-tagged proteins identified E. coli NemA as a highly efficient Cr(VI) reductase (kcat/KM = 1.1×105 M−1s−1 with NADH as cofactor). Fusion of nemA to the polyhydroxyalkanoate synthase gene phaC from Ralstonia eutropha enabled high-level biosynthesis of functionalized polyhydroxyalkanoate granules displaying stable and active NemA on their surface. When these granules were combined with either Bacillus subtilis glucose dehydrogenase or Candida boidinii formate dehydrogenase as a cofactor regenerating partner, high levels of chromate transformation were observed with only low initial concentrations of expensive NADH cofactor being required, the overall reaction being powered by consumption of the cheap sacrificial substrates glucose or formic acid, respectively. This system therefore offers promise as an economic solution for ex situ Cr(VI) remediation. 相似文献
95.
Leonie E. Paulis Alexandra M. Klein Alexander Ghanem Tessa Geelen Bram F. Coolen Martin Breitbach Katrin Zimmermann Klaas Nicolay Bernd K. Fleischmann Wilhelm Roell Gustav J. Strijkers 《PloS one》2013,8(4)
Aims
Controversy exists in regard to the beneficial effects of transplanting cardiac or somatic progenitor cells upon myocardial injury. We have therefore investigated the functional short- and long-term consequences after intramyocardial transplantation of these cell types in a murine lesion model.Methods and Results
Myocardial infarction (MI) was induced in mice (n = 75), followed by the intramyocardial injection of 1−2×105 luciferase- and GFP-expressing embryonic cardiomyocytes (eCMs), skeletal myoblasts (SMs), mesenchymal stem cells (MSCs) or medium into the infarct. Non-treated healthy mice (n = 6) served as controls. Bioluminescence and fluorescence imaging confirmed the engraftment and survival of the cells up to seven weeks postoperatively. After two weeks MRI was performed, which showed that infarct volume was significantly decreased by eCMs only (14.8±2.2% MI+eCM vs. 26.7±1.6% MI). Left ventricular dilation was significantly decreased by transplantation of any cell type, but most efficiently by eCMs. Moreover, eCM treatment increased the ejection fraction and cardiac output significantly to 33.4±2.2% and 22.3±1.2 ml/min. In addition, this cell type exclusively and significantly increased the end-systolic wall thickness in the infarct center and borders and raised the wall thickening in the infarct borders. Repetitive echocardiography examinations at later time points confirmed that these beneficial effects were accompanied by better survival rates.Conclusion
Cellular cardiomyoplasty employing contractile and electrically coupling embryonic cardiomyocytes (eCMs) into ischemic myocardium provoked significantly smaller infarcts with less adverse remodeling and improved cardiac function and long-term survival compared to transplantation of somatic cells (SMs and MSCs), thereby proving that a cardiomyocyte phenotype is important to restore myocardial function. 相似文献96.
97.
Daniel Ritterskamp Christoph Feenders Daniel Bearup Bernd Blasius 《Theoretical Ecology》2016,9(4):501-512
Many empirical food webs contain multiple resources, which can lead to the emergence of sub-communities—partitions—in a food web that are weakly connected with each other. These partitions interact and affect the complete food web. However, the fact that food webs can contain multiple resources is often neglected when describing food web assembly theoretically, by considering only a single resource. We present an allometric, evolutionary food web model and include two resources of different sizes. Simulations show that an additional resource can lead to the emergence of partitions, i.e. groups of species that specialise on different resources. For certain arrangements of these partitions, the interactions between them alter the food web properties. First, these interactions increase the variety of emerging network structures, since hierarchical bodysize relationships are weakened. Therefore, they could play an important role in explaining the variety of food web structures that is observed in empirical data. Second, interacting partitions can destabilise the population dynamics by introducing indirect interactions with a certain strength between predator and prey species, leading to biomass oscillations and evolutionary intermittence. 相似文献
98.
99.
Benedikt Mothes Kirsten Bucher Susanne Ammon-Treiber Matthias Schwab Roland P. Piekorz Emilio Hirsch Bernd Nürnberg Sandra Beer-Hammer 《PloS one》2016,11(7)
The catalytical isoforms p110γ and p110δ of phosphatidylinositide 3-kinase γ (PI3Kγ) and PI3Kδ play an important role in the pathogenesis of asthma. Two key elements in allergic asthma are increased levels of eosinophils and IgE. Dual pharmacological inhibition of p110γ and p110δ reduces asthma-associated eosinophilic lung infiltration and ameliorates disease symptoms, whereas the absence of enzymatic activity in p110γKOδD910A mice increases IgE and basal eosinophil counts. This suggests that long-term inhibition of p110γ and p110δ might exacerbate asthma. Here, we analysed mice genetically deficient for both catalytical subunits (p110γ/δ-/-) and determined basal IgE and eosinophil levels and the immune response to ovalbumin-induced asthma. Serum concentrations of IgE, IL-5 and eosinophil numbers were significantly increased in p110γ/δ-/- mice compared to single knock-out and wildtype mice. However, p110γ/δ-/- mice were protected against OVA-induced infiltration of eosinophils, neutrophils, T and B cells into lung tissue and bronchoalveolar space. Moreover, p110γ/δ-/- mice, but not single knock-out mice, showed a reduced bronchial hyperresponsiveness. We conclude that increased levels of eosinophils and IgE in p110γ/δ-/- mice do not abolish the protective effect of p110γ/δ-deficiency against OVA-induced allergic airway inflammation. 相似文献
100.