scholarly journals Toxicity of Bioactive and Probiotic Marine Bacteria and Their Secondary Metabolites in Artemia sp. and Caenorhabditis elegans as Eukaryotic Model Organisms

2013 ◽  
Vol 80 (1) ◽  
pp. 146-153 ◽  
Author(s):  
Anna Katrin Neu ◽  
Maria Månsson ◽  
Lone Gram ◽  
María J. Prol-García
Keyword(s):  
Adverse Effect ◽  
Caenorhabditis Elegans ◽  
Side Effects ◽  
Point Of View ◽  
Model Organisms ◽  
Content Type ◽  
Tropodithietic Acid ◽  
Antibiotic Compounds ◽  
Eukaryotic Organisms ◽  
Phaeobacter Inhibens

ABSTRACTWe have previously reported that some strains belonging to the marineActinobacteriaclass, thePseudoalteromonasgenus, theRoseobacterclade, and thePhotobacteriaceaeandVibrionaceaefamilies produce both antibacterial and antivirulence compounds, and these organisms are interesting from an applied point of view as fish probiotics or as a source of pharmaceutical compounds. The application of either organisms or compounds requires that they do not cause any side effects, such as toxicity in eukaryotic organisms. The purpose of this study was to determine whether these bacteria or their compounds have any toxic side effects in the eukaryotic organismsArtemiasp. andCaenorhabditis elegans.Arthrobacter davidanieliWX-11,Pseudoalteromonas luteoviolaceaS4060,P. piscicidaS2049,P. rubraS2471,Photobacterium halotoleransS2753, andVibrio coralliilyticusS2052 were lethal to either or both model eukaryotes. The toxicity ofP. luteoviolaceaS4060 could be related to the production of the antibacterial compound pentabromopseudilin, while the adverse effect observed in the presence ofP. halotoleransS2753 andV. coralliilyticusS2052 could not be explained by the production of holomycin nor andrimid, the respective antibiotic compounds in these organisms. In contrast, the tropodithietic acid (TDA)-producing bacteriaPhaeobacter inhibensDSM17395 andRuegeria mobilisF1926 and TDA itself had no adverse effect on the target organisms. These results reaffirm TDA-producingRoseobacterbacteria as a promising group to be used as probiotics in aquaculture, whereasActinobacteria,Pseudoalteromonas,Photobacteriaceae, andVibrionaceaeshould be used with caution.

scholarly journals Influence of Iron on Production of the Antibacterial Compound Tropodithietic Acid and Its Noninhibitory Analog in Phaeobacter inhibens

2015 ◽  
Vol 82 (2) ◽  
pp. 502-509 ◽  
Author(s):  
Paul W. D'Alvise ◽  
Christopher B. W. Phippen ◽  
Kristian F. Nielsen ◽  
Lone Gram
Keyword(s):  
Mass Spectrometry ◽  
Antibacterial Activity ◽  
High Resolution Mass Spectrometry ◽  
Biologically Active ◽  
Brown Pigment ◽  
Marine Broth ◽  
Content Type ◽  
Tropodithietic Acid ◽  
Antibacterial Compound ◽  
Phaeobacter Inhibens

ABSTRACTTropodithietic acid (TDA) is an antibacterial compound produced by somePhaeobacterandRuegeriaspp. of theRoseobacterclade. TDA production is studied in marine broth or agar since antibacterial activity in other media is not observed. The purpose of this study was to determine how TDA production is influenced by substrate components. High concentrations of ferric citrate, as present in marine broth, or other iron sources were required for production of antibacterially active TDA. However, when supernatants of noninhibitory, low-iron cultures ofPhaeobacter inhibenswere acidified, antibacterial activity was detected in a bioassay. The absence of TDA in nonacidified cultures and the presence of TDA in acidified cultures were verified by liquid chromatography–high-resolution mass spectrometry. A noninhibitory TDA analog (pre-TDA) was produced byP. inhibens,Ruegeria mobilisF1926, andPhaeobactersp. strain 27-4 under low-iron concentrations and was instantaneously converted to TDA when pH was lowered. Production of TDA in the presence of Fe3+coincides with formation of a dark brown substance, which could be precipitated by acid addition. From this brown pigment TDA could be liberated slowly with aqueous ammonia, and both direct-infusion mass spectrometry and elemental analysis indicated a [FeIII(TDA)2]xcomplex. The pigment could also be produced by precipitation of pure TDA with FeCl3. Our results raise questions about how biologically active TDA is produced in natural marine settings where iron is typically limited and whether the affinity of TDA to iron points to a physiological or ecological function of TDA other than as an antibacterial compound.

scholarly journals Small-Molecule Mn Antioxidants in Caenorhabditis elegans and Deinococcus radiodurans Supplant MnSOD Enzymes during Aging and Irradiation

mBio ◽  
2022 ◽  
Author(s):  
Elena K. Gaidamakova ◽  
Ajay Sharma ◽  
Vera Y. Matrosova ◽  
Olga Grichenko ◽  
Robert P. Volpe ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Caenorhabditis Elegans ◽  
Oxidative Damage ◽  
Small Molecule ◽  
Radiation Resistance ◽  
Deinococcus Radiodurans ◽  
Current Theory ◽  
Model Organisms ◽  
Content Type ◽  
Cellular Defense

The current theory of cellular defense against oxidative damage identifies antioxidant enzymes as primary defenders against ROS, with MnSOD being the preeminent superoxide (O 2 •− ) scavenger. However, MnSOD is shown to be dispensable both for radiation resistance and longevity in model organisms, the bacterium Deinococcus radiodurans and the nematode Caenorhabditis elegans .

The glycomes of Caenorhabditis elegans and other model organisms

2002 ◽  
Vol 69 ◽  
pp. 117-134 ◽  
Author(s):  
Stuart M. Haslam ◽  
David Gems ◽  
Howard R. Morris ◽  
Anne Dell
Keyword(s):  
Caenorhabditis Elegans ◽  
Current Knowledge ◽  
Structural Data ◽  
Model Organisms ◽  
Entire Genome ◽  
C Elegans ◽  
The Face ◽  
Area Of Concern ◽  
Nematode Worm

There is no doubt that the immense amount of information that is being generated by the initial sequencing and secondary interrogation of various genomes will change the face of glycobiological research. However, a major area of concern is that detailed structural knowledge of the ultimate products of genes that are identified as being involved in glycoconjugate biosynthesis is still limited. This is illustrated clearly by the nematode worm Caenorhabditis elegans, which was the first multicellular organism to have its entire genome sequenced. To date, only limited structural data on the glycosylated molecules of this organism have been reported. Our laboratory is addressing this problem by performing detailed MS structural characterization of the N-linked glycans of C. elegans; high-mannose structures dominate, with only minor amounts of complex-type structures. Novel, highly fucosylated truncated structures are also present which are difucosylated on the proximal N-acetylglucosamine of the chitobiose core as well as containing unusual Fucα1–2Gal1–2Man as peripheral structures. The implications of these results in terms of the identification of ligands for genomically predicted lectins and potential glycosyltransferases are discussed in this chapter. Current knowledge on the glycomes of other model organisms such as Dictyostelium discoideum, Saccharomyces cerevisiae and Drosophila melanogaster is also discussed briefly.

Synergistic action of propolis with levodopa in the management of Parkinsonism in Drosophila melanogaster

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
Emmanuel Tiyo Ayikobua ◽  
Josephine Kasolo ◽  
Keneth Iceland Kasozi ◽  
Ejike Daniel Eze ◽  
Abass Safiriyu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Drosophila Melanogaster ◽  
Side Effects ◽  
Motor Activity ◽  
Ethanolic Extract ◽  
Synergistic Action ◽  
Content Type ◽  
Treatment Groups ◽  
Ethanolic Extract Of Propolis ◽  
Different Doses

AbstractBackgroundThe Phosphatase and tensin-induced putative kinase 1 (PINK1B9) mutant for Drosophila melanogaster is a key tool that has been used in assessing the pathology of Parkinsonism and its possible remedy. This research was targeted toward determining the effects of ethanolic extract of propolis, with levodopa therapy in the management of Parkinsonism.MethodThe PINK1B9 flies were divided into groups and fed with the different treatment doses of ethanoic extract of propolis. The treatment groups were subjected to 21 days of administration of propolis and the levodopa at different doses after which percentage climbing index, antioxidant activity and lifespan studies were done.ResultsPropolis alone improved motor activity, antioxidant and lifespan in Drosophila melanogaster than in PINK1 flies. Propolis in combination with levodopa significantly (P<0.05) improved physiological parameters at higher than lower concentrations in Parkinsonism Drosophila melanogaster demonstrating its importance in managing side effects associated with levodopa.ConclusionPropolis is a novel candidate as an alternative and integrative medicinal option to use in the management of Parkinsonism in both animals and humans at higher concentrations.

Congenital Lymphatic Malformation and Aortic Aneurysm in a Patient with TSC2 Mutation

2019 ◽  
Vol 51 (01) ◽  
pp. 057-061 ◽  
Author(s):  
Adelheid Wiemer-Kruel ◽  
Hans Mayer ◽  
Peter Ewert ◽  
Stefan Martinoff ◽  
Hans-Henning Eckstein ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Side Effects ◽  
Aortic Aneurysm ◽  
Tuberous Sclerosis ◽  
Somatic Growth ◽  
Lymphatic Malformation ◽  
Aortic Aneurysms ◽  
Operative Intervention

AbstractWe present a 7-year-old boy with tuberous sclerosis and congenital segmental lymphedema (CSL) of the left leg, as well as two aortic aneurysms. He was treated with everolimus (EVE) since the age of 14 months. His CSL regressed under treatment with EVE. His first aneurysms required operative intervention at age of 17 months. Four months afterward a new aortic aneurysm had been detected above the Dracon graft, but this one remained stable since that time. The patient didn't experience severe side effects. EVE has been well tolerated without disturbance of somatic growth or serious adverse effect.

scholarly journals Autophagy-Related Protein ATG8 Has a Noncanonical Function for Apicoplast Inheritance in Toxoplasma gondii

mBio ◽  
2015 ◽  
Vol 6 (6) ◽  
Author(s):  
Maude F. Lévêque ◽  
Laurence Berry ◽  
Michael J. Cipriano ◽  
Hoa-Mai Nguyen ◽  
Boris Striepen ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Growth Conditions ◽  
Model Organisms ◽  
Secondary Endosymbiosis ◽  
Related Protein ◽  
Content Type ◽  
Superresolution Microscopy ◽  
Animal Pathogens ◽  
Cellular Components ◽  
Catabolic Process

ABSTRACT Autophagy is a catabolic process widely conserved among eukaryotes that permits the rapid degradation of unwanted proteins and organelles through the lysosomal pathway. This mechanism involves the formation of a double-membrane structure called the autophagosome that sequesters cellular components to be degraded. To orchestrate this process, yeasts and animals rely on a conserved set of autophagy-related proteins (ATGs). Key among these factors is ATG8, a cytoplasmic protein that is recruited to nascent autophagosomal membranes upon the induction of autophagy. Toxoplasma gondii is a potentially harmful human pathogen in which only a subset of ATGs appears to be present. Although this eukaryotic parasite seems able to generate autophagosomes upon stresses such as nutrient starvation, the full functionality and biological relevance of a canonical autophagy pathway are as yet unclear. Intriguingly, in T. gondii, ATG8 localizes to the apicoplast under normal intracellular growth conditions. The apicoplast is a nonphotosynthetic plastid enclosed by four membranes resulting from a secondary endosymbiosis. Using superresolution microscopy and biochemical techniques, we show that TgATG8 localizes to the outermost membrane of this organelle. We investigated the unusual function of TgATG8 at the apicoplast by generating a conditional knockdown mutant. Depletion of TgATG8 led to rapid loss of the organelle and subsequent intracellular replication defects, indicating that the protein is essential for maintaining apicoplast homeostasis and thus for survival of the tachyzoite stage. More precisely, loss of TgATG8 led to abnormal segregation of the apicoplast into the progeny because of a loss of physical interactions of the organelle with the centrosomes. IMPORTANCE By definition, autophagy is a catabolic process that leads to the digestion and recycling of eukaryotic cellular components. The molecular machinery of autophagy was identified mainly in model organisms such as yeasts but remains poorly characterized in phylogenetically distant apicomplexan parasites. We have uncovered an unusual function for autophagy-related protein ATG8 in Toxoplasma gondii: TgATG8 is crucial for normal replication of the parasite inside its host cell. Seemingly unrelated to the catabolic autophagy process, TgATG8 associates with the outer membrane of the nonphotosynthetic plastid harbored by the parasite called the apicoplast, and there it plays an important role in the centrosome-driven inheritance of the organelle during cell division. This not only reveals an unexpected function for an autophagy-related protein but also sheds new light on the division process of an organelle that is vital to a group of important human and animal pathogens.

Comparison of the reluctance laminated and solid rotor synchronous machine operating at high temperatures

2019 ◽  
Vol 38 (4) ◽  
pp. 1111-1119 ◽  
Author(s):  
Marcin Lefik ◽  
Krzysztof Komeza ◽  
Ewa Napieralska-Juszczak ◽  
Daniel Roger ◽  
Piotr Andrzej Napieralski
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Three Dimensional ◽  
Synchronous Machine ◽  
Point Of View ◽  
Heat Sources ◽  
Model Calculations ◽  
Content Type ◽  
Thermal Phenomenon ◽  
Practical Implications

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program including effect of rotation and the resulting eddy current losses. To analyse the thermal phenomenon, the 3D coupled thermal-fluid (CFD) model is used. Findings The presented results show clearly that laminated construction is much better from a point of view of efficiency and temperature. However, solid construction can be interesting for high speed machines due to their mechanical robustness. Research limitations/implications The main problem, despite the use of parallel calculations, is the long calculation time. Practical implications The obtained simulation and experimental results show the possibility of building a machine operating at a much higher ambient temperature than it was previously produced for example in the vicinity of the aircraft turbines. Originality/value The paper presents the application of fully three-dimensional coupled electromagnetic and thermal analysis of new machine constructions designed for elevated temperature.

Journey towards best practices in acting on early warning signs in complex projects within a Russian context

2015 ◽  
Vol 8 (4) ◽  
pp. 828-843 ◽  
Author(s):  
Gulnara Sharaborova ◽  
Derek H.T. Walker ◽  
Guinevere Gilbert
Keyword(s):  
Early Warning ◽  
Point Of View ◽  
Warning Signs ◽  
Theory And Practice ◽  
Doctoral Study ◽  
Content Type ◽  
Early Warning Signs ◽  
Complex Projects ◽  
Research Findings ◽  
Phd Thesis

Purpose – The purpose of this paper is to provide a summary report and reflect on a recently passed PhD thesis (Sharaborova, 2014b) related to project management topics. Design/methodology/approach – This paper focussed on narrative reflection upon the completed doctoral journey. Findings – This paper presents the thesis findings, the research models, the guide in dealing with the early warning signs that developed as a result of this research and the contribution made to theory and practice. Research limitations/implications – Limitations of the research and the perspectives of the further diffusion of the research findings are considered. Originality/value – This TRN is a PhD candidate’s point of view as well as the opinions of the scientific research supervisors about the doctoral study and its outcome. The paper could be useful for novice researchers who wish to conduct their research and did not yet make a decision.

Economic thought in the 17th and 18th centuries: a linguistic approach

2015 ◽  
Vol 23 (3) ◽  
pp. 260-270
Author(s):  
Iara Vigo de Lima
Keyword(s):  
Economic Thought ◽  
Point Of View ◽  
Content Type ◽  
Front Position ◽  
History Of ◽  
Epistemological Model ◽  
Theory Of Language ◽  
Theory Of Value ◽  
Linguistic Approach ◽  
Practical Implications

Purpose – The purpose of this paper is to analyse Michel Foucault’s new epistemological model regarding an analogy between the theory of language and economic thought in the seventeenth and eighteenth centuries. Design/methodology/approach – Through the scrutiny of language, Foucault intended to demonstrate that some analogies, among different branches of knowledge (interdiscursive practice), allow us to apprehend the underlying configuration of thought regarding ontological and epistemological conditions that have historically determined knowledge. He draws a parallel between four theoretical segments borrowed from general grammar (Attribution, Articulation, Designation and Derivation) and economic thought on wealth. Findings – One of the most remarkable propositions of this approach is that the theory of language and economic thought were epistemologically isomorphic in that context. What the theory of language stated in relation to “attribution” and “articulation” corresponded to the “theory of value” in economic thought. What grammar investigated regarding “designation” and “derivation” was analogous to the “theory of money and trade” in economic thought. The relationships that were – directly and diagonally – identified between and among them led to the conclusion that there was ‘a circular and surface causality’ in economic thought insofar as “circulation” preceded “production”. It was “superficial” because it could not find an explanation for the cause of “wealth”, which was only possible when “production” was placed in the front position of theories. Practical implications – Such an epistemological point of view can inspire other studies in the history of economic thought. Originality/value – This paper offers a perspective on how to think about the history of ontological and epistemological conditions of economic thought.

The moderating impact of emotions on customer equity drivers and loyalty intentions

2017 ◽  
Vol 29 (2) ◽  
pp. 239-264 ◽  
Author(s):  
Zohaib Razzaq ◽  
Salman Yousaf ◽  
Zhao Hong
Keyword(s):  
Service Delivery ◽  
Customer Service ◽  
Customer Loyalty ◽  
Positive Emotions ◽  
Survey Design ◽  
Emotional Responses ◽  
Point Of View ◽  
Customer Equity ◽  
Content Type ◽  
Loyalty Intentions

Purpose The purpose of this paper is to investigate the significant contribution of emotions along with other conventional loyalty drivers on the loyalty intentions. Design/methodology/approach The influence of three conventional loyalty drivers, i.e., value equity, brand equity, relationship equity on loyalty intentions was investigated by further exploring the moderating effects of negative and positive emotions. A sample of 834 Pakistani consumers in the supermarkets and banking industries was studied employing store-intercept survey design. Findings Consumer behavior is driven by emotions in both the supermarkets and banking context. Thus, in order to better predict customer loyalty intentions, the emotional component is crucial and should be included along with other cognitive components. Practical implications Since customers’ emotional responses throughout service delivery are strongly linked to loyalty, therefore supermarkets and bank service managers need to make sure that the customers experience with their services as pleasurable as possible and for this purpose, customer service employees need to be trained in order to better understand the customers’ emotional responses during the course of service delivery process. Originality/value The present study complements the existing literature regarding the role of emotions in service settings and offers a new point of view for the linkage among emotions, customer equity drivers and customer loyalty intentions.

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