51 research outputs found

    Biomass pretreatment affects Ustilago maydis in producing itaconic acid

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    <p>Abstract</p> <p>Background</p> <p>In the last years, the biotechnological production of platform chemicals for fuel components has become a major focus of interest. Although ligno-cellulosic material is considered as suitable feedstock, the almost inevitable pretreatment of this recalcitrant material may interfere with the subsequent fermentation steps. In this study, the fungus <it>Ustilago maydis </it>was used to produce itaconic acid as platform chemical for the synthesis of potential biofuels such as 3-methyltetrahydrofuran. No studies, however, have investigated how pretreatment of ligno-cellulosic biomass precisely influences the subsequent fermentation by <it>U. maydis</it>. Thus, this current study aims to first characterize <it>U. maydis </it>in shake flasks and then to evaluate the influence of three exemplary pretreatment methods on the cultivation and itaconic acid production of this fungus. Cellulose enzymatically hydrolysed in seawater and salt-assisted organic-acid catalysed cellulose were investigated as substrates. Lastly, hydrolysed hemicellulose from fractionated beech wood was applied as substrate.</p> <p>Results</p> <p><it>U. maydis </it>was characterized on shake flask level regarding its itaconic acid production on glucose. Nitrogen limitation was shown to be a crucial condition for the production of itaconic acid. For itaconic acid concentrations above 25 g/L, a significant product inhibition was observed. Performing experiments that simulated influences of possible pretreatment methods, <it>U. maydis </it>was only slightly affected by high osmolarities up to 3.5 osmol/L as well as of 0.1 M oxalic acid. The production of itaconic acid was achieved on pretreated cellulose in seawater and on the hydrolysed hemicellulosic fraction of pretreated beech wood.</p> <p>Conclusion</p> <p>The fungus <it>U. maydis </it>is a promising producer of itaconic acid, since it grows as single cells (yeast-like) in submerged cultivations and it is extremely robust in high osmotic media and real seawater. Moreover, <it>U. maydis </it>can grow on the hemicellulosic fraction of pretreated beech wood. Thereby, this fungus combines important advantages of yeasts and filamentous fungi. Nevertheless, the biomass pretreatment does indeed affect the subsequent itaconic acid production. Although <it>U. maydis </it>is insusceptible to most possible impurities from pretreatment, high amounts of salts or residues of organic acids can slow microbial growth and decrease the production. Consequently, the pretreatment step needs to fit the prerequisites defined by the actual microorganisms applied for fermentation.</p

    Itaconic acid indicates cellular but not systemic immune system activation

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    Itaconic acid is produced by mammalian leukocytes upon pro-inflammatory activation. It appears to inhibit bacterial growth and to rewire the metabolism of the host cell by inhibiting succinate dehydrogenase. Yet, it is unknown whether itaconic acid acts only intracellularly, locally in a paracrine fashion, or whether it is even secreted from the inflammatory cells at meaningful levels in peripheral blood of patients with severe inflammation or sepsis. The aim of this study was to determine the release rate of itaconic acid from pro-inflammatory activated macrophages in vitro and to test for the abundance of itaconic acid in bodyfluids of patients suffering from acute inflammation. We demonstrate that excretion of itaconic acid happens at a low rate and that it cannot be detected in significant amounts in plasma or urine of septic patients or in liquid from bronchial lavage of patients with pulmonary inflammation. We conclude that itaconic acid may serve as a pro-inflammatory marker in immune cells but that it does not qualify as a biomarker in the tested body fluids

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    Classification of current anticancer immunotherapies

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    During the past decades, anticancer immunotherapy has evolved from a promising therapeutic option to a robust clinical reality. Many immunotherapeutic regimens are now approved by the US Food and Drug Administration and the European Medicines Agency for use in cancer patients, and many others are being investigated as standalone therapeutic interventions or combined with conventional treatments in clinical studies. Immunotherapies may be subdivided into “passive” and “active” based on their ability to engage the host immune system against cancer. Since the anticancer activity of most passive immunotherapeutics (including tumor-targeting monoclonal antibodies) also relies on the host immune system, this classification does not properly reflect the complexity of the drug-host-tumor interaction. Alternatively, anticancer immunotherapeutics can be classified according to their antigen specificity. While some immunotherapies specifically target one (or a few) defined tumor-associated antigen(s), others operate in a relatively non-specific manner and boost natural or therapy-elicited anticancer immune responses of unknown and often broad specificity. Here, we propose a critical, integrated classification of anticancer immunotherapies and discuss the clinical relevance of these approaches

    Causes and consequences of demographic change

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    Die Bevölkerungsdynamiken haben sich in den letzten Jahrhunderten entscheidend verändert. Im späten 18. Jahrhundert, vor dem Einsetzen des demografischen Wandels, waren die meisten Menschen unter 30, verheiratete Frauen bekamen 8 oder mehr Kinder und die Lebenserwartung lag unter 40 Jahren. Heute liegt die Lebenserwartung in den meisten entwickelten Volkswirtschaften über 80 Jahren, die Fertilitätsrate ist in fast allen reichen Ländern unter das Selbsterhaltungsniveau gefallen und das Durchschnittsalter der Bevölkerung liegt bei über 40. Vor dem Hintergrund dieser beispiellosen demografischen Veränderungen analysieren die fünf Aufsätze dieser Dissertation 1) die Rolle der öffentlichen Renten für den historischen Sterblichkeits- und Geburtenrückgang, 2) untersuchen die Folgen der Bevölkerungsalterung aus politökonomischer und makroökonomischer Sicht und 3) analysieren die Auswirkungen von Rentenanreizen auf die Arbeitsmarktbeteiligung älterer Menschen

    A systematic review on diagnostics and surgical treatment of adult right-sided Bochdalek hernias and presentation of the current management pathway

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    Purpose!#!Bochdalek hernia is a congenital diaphragmatic hernia. The incidence in adults is estimated around 0.17%. Right-sided hernias are much more seldom than left-sided ones because of faster closure of the right pleuroperitoneal canal and the protective effect of the liver. Due to its rarity, there have been no large prospective or retrospective studies following great need for evidence-based diagnostics and treatment strategies. In this systematic review, we evaluated the current evidence of diagnostics, treatment, and follow-up of adult right-sided Bochdalek hernias.!##!Methods!#!According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines a systematic literature review was conducted in PubMed and Cochrane library from 2004 to January 2021. The literature search included all studies with non-traumatic right-sided Bochdalek hernias. Literature on left- or both-sided, pregnancy-associated, pediatric, and other types of hernias were explicitly excluded. Quality assessment of the included studies was performed.!##!Results!#!Database search identified 401 records. After eligibility screening 41 studies describing 44 cases of right-sided non-traumatic Bochdalek hernias in adulthood were included for final analysis. Based upon the systematic literature review, the current diagnostic, therapeutic, and follow-up management pathway for this rare surgical emergency is presented.!##!Conclusion!#!This systematic review underlined that most studies investigating management of adult non-traumatic right-sided Bochdalek hernias are of moderate to low methodological quality. Hernias tend to occur more frequently in middle-aged and older women presenting with abdominal pain and dyspnea. A rapid and accurate diagnosis following surgical repair and regular follow-up is mandatory. High-quality studies focusing on the management of this rare entity are urgently needed
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