Cytokinesis in bloodstream stage Trypanosoma brucei requires a family of katanins and spastin

Microtubule severing enzymes regulate microtubule dynamics in a wide range of organisms and are implicated in important cell cycle processes such as mitotic spindle assembly and disassembly, chromosome movement and cytokinesis. Here we explore the function of several microtubule severing enzyme homologues, the katanins (KAT80, KAT60a, KAT60b and KAT60c), spastin (SPA) and fidgetin (FID) in the bloodstream stage of the African trypanosome parasite, Trypanosoma brucei. The trypanosome cytoskeleton is microtubule based and remains assembled throughout the cell cycle, necessitating its remodelling during cytokinesis. Using RNA interference to deplete individual proteins, we show that the trypanosome katanin and spastin homologues are non-redundant and essential for bloodstream form proliferation. Further, cell cycle analysis revealed that these proteins play essential but discrete roles in cytokinesis. The KAT60 proteins each appear to be important during the early stages of cytokinesis, while downregulation of KAT80 specifically inhibited furrow ingression and SPA depletion prevented completion of abscission. In contrast, RNA interference of FID did not result in any discernible effects. We propose that the stable microtubule cytoskeleton of T. brucei necessitates the coordinated action of a family of katanins and spastin to bring about the cytoskeletal remodelling necessary to complete cell divisio

Heavy Ion Carcinogenesis and Human Space Exploration

Prior to the human exploration of Mars or long duration stays on the Earth s moon, the risk of cancer and other diseases from space radiation must be accurately estimated and mitigated. Space radiation, comprised of energetic protons and heavy nuclei, has been show to produce distinct biological damage compared to radiation on Earth, leading to large uncertainties in the projection of cancer and other health risks, while obscuring evaluation of the effectiveness of possible countermeasures. Here, we describe how research in cancer radiobiology can support human missions to Mars and other planets

Outcome assessment in dermatology clinical trials and cochrane reviews: call for a dermatology‐specific outcome taxonomy

Background: Standardized outcome reporting is crucial for trial evidence synthesis and translation of findings into clinical decision making. The OMERACT 2.0 Filter and COMET outcome domain taxonomy propose frameworks for consistent reporting of outcomes. There is an absence of a uniform dermatology-specific reporting strategy that uses precise and consistent outcome definitions.Objectives: Our aim was to map efficacy/effectiveness outcomes assessed in dermatological trials to the OMERACT 2.0 Filter as a starting point for developing an outcome taxonomy in dermatology.Methods: We critically appraised 10 Cochrane Skin Reviews randomly selected from all 69 Cochrane Skin Reviews published until 01/2015 and the 220 trials included covering a broad spectrum of dermatological conditions and interventions. Efficacy/effectiveness outcomes were mapped to core areas and domains according to the OMERACT 2.0 Filter. The extracted trial outcomes were used for critical appraisal of outcome reporting in dermatology trials and for the preliminary development of a dermatology-specific outcome taxonomy.Results: The allocation of 1,086 extracted efficacy/effectiveness outcomes to the OMERACT 2.0 Filter resulted in a hierarchically structured dermatology-specific outcome classification. In 506 outcomes (47%) the outcome concept to be measured was insufficiently described, hindering meaningful evidence synthesis. Although the core areas assessed in different dermatology trials of the same condition overlap considerably, quantitative evidence synthesis usually failed due to imprecise outcome definitions, non-comparable outcome measurement instruments, metrics and reporting.Conclusions: We present an efficacy/effectiveness outcome classification as a starting point for a dermatology-specific taxonomy to provide trialists and reviewers with the opportunity to better synthesize and compare evidence