31 research outputs found
Apoptosis-Like Death in Bacteria Induced by HAMLET, a Human Milk Lipid-Protein Complex
Background: Apoptosis is the primary means for eliminating unwanted cells in multicellular organisms in order to preserve tissue homeostasis and function. It is characterized by distinct changes in the morphology of the dying cell that are orchestrated by a series of discrete biochemical events. Although there is evidence of primitive forms of programmed cell death also in prokaryotes, no information is available to suggest that prokaryotic death displays mechanistic similarities to the highly regulated programmed death of eukaryotic cells. In this study we compared the characteristics of tumor and bacterial cell death induced by HAMLET, a human milk complex of alpha-lactalbumin and oleic acid. Methodology/Principal Findings: We show that HAMLET-treated bacteria undergo cell death with mechanistic and morphologic similarities to apoptotic death of tumor cells. In Jurkat cells and Streptococcus pneumoniae death was accompanied by apoptosis-like morphology such as cell shrinkage, DNA condensation, and DNA degradation into high molecular weight fragments of similar sizes, detected by field inverse gel electrophoresis. HAMLET was internalized into tumor cells and associated with mitochondria, causing a rapid depolarization of the mitochondrial membrane and bound to and induced depolarization of the pneumococcal membrane with similar kinetic and magnitude as in mitochondria. Membrane depolarization in both systems required calcium transport, and both tumor cells and bacteria were found to require serine protease activity (but not caspase activity) to execute cell death. Conclusions/Significance: Our results suggest that many of the morphological changes and biochemical responses associated with apoptosis are present in prokaryotes. Identifying the mechanisms of bacterial cell death has the potential to reveal novel targets for future antimicrobial therapy and to further our understanding of core activation mechanisms of cell death in eukaryote cells
TRY plant trait database â enhanced coverage and open access
Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of traitâbased plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for âplant growth formâ. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and traitâenvironmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Micro-particle adhesion: Measurement and simulation
Solids processing unit operations are a basic component of most manufacturing processes, even when the final product is not strictly a dry solid. Processes like particle flow, mixing, storage, fluidization, and compaction are greatly affected by the cohesive forces between particles within powders and adhesive forces between powder particles and process surfaces. The ability to engineer particles with desirable handling properties represents an opportunity to reduce bottlenecking and overall manufacturing costs. The key parameters affecting particle cohesion and adhesion must be identified, quantified, and modeled to provide a science-based approach to manufacturing decision-making, improvement of existing process equipment, and materials selection and design. This thesis work focuses on the development of a detailed understanding of microparticle adhesion and a refinement of an experimentally validated modeling framework. While a number of surface forces become relevant when the primary particle diameter is reduced to 10 ÎŒm or below, the van der Waals (vdW) force dominates the interaction when relative humidity and electrostatics are minimized. A number of key parameters can have a profound effect on the strength of the vdW force, but this work is limited to characterizing particle size, particle shape, and surface roughness effects. The development of a novel particle tomography technique to simultaneously characterize particle shape and roughness using a focused ion beam and scanning electron microscope is emphasized. While this work examined materials and model systems that were of interest to the pharmaceutical industry, the insights gained in understanding particle-level adhesion phenomena are applicable to all particulate systems
Cancer-related fatigue and sleep deficiency in cancer care continuum: concepts, assessment, clusters, and management
Throughout the cancer continuum, patients are faced with the cancer- and treatment-related side effects that can have a negative impact on their overall quality of life. Cancer-related fatigue (CRF) and sleep deficiency are among the symptoms that patients and their caregivers most often experience. An increasing body of literature suggests that a strong correlation between CRF and sleep deficiency exists, indicating that they may be reciprocally related and that they may have similar underlying etiology. This paper aims at bringing together the opinions of leading cancer control (i.e., CRF and sleep) and oncology experts in order to increase the understanding of CRF and sleep deficiency's assessment, associated symptom clustering, symptom burden shared by caregivers, and CRF and sleep deficiency management in the cancer care context