Search results for "Kinesis"
showing 9 items of 39 documents
Microtubules and the First Cell Cycle in Cultured Mesophyll Protoplasts of Nicotiana
1990
When a protoplast is excised and cultured in vitro, an organized pattern of cell divisions must be reestablished to permit organogenesis, including plant regeneration. However, in a number of species protoplasts have proved to be very recalcitrant with regard to cell division and/or plant regeneration. In an attempt to find means to overcome the regeneration problem in recalcitrant species we are investigating the processes leading to cell division and morphogenesis in mesophyll protoplasts of the model system Nicotiana. Of particular interest are the initiation of the cell cycle and the coordination of progress through the cycles as a prerequisite for subsequent morphogenesis. Mesophyll pr…
Functional food science and behaviour and psychological functions
2017
INSERM-Unite 341 et Service de Nutrition, Hotel-Dieu, Paris, France. bellisle@imaginet.frThe impact of ingesting various foods on psychological and behavioural functions is a topic of both interest and concern to the general public. In this article, the scientific literature concerning demonstrated cause-and-effect relationships is reviewed, beginning with methodological considerations specific to the quantification of particular behaviours and psychological events. The essential function of food is to satisfy hunger and the need for essential nutrients. The contributions of macronutrients to appetite and satiety are described, as well as their impact on metabolism and energy balance. Funct…
p38α deficiency and oxidative stress cause cytokinesis failure in hepatocytes.
2015
Cytokinesis is the last step in mitosis and it implies re-organization of the actin cytoskeleton. Its failure is one of the major mechanisms of polyploidy and binucleation in mammals. Our aims were 1) to assess the role of redox-sensitive p38α MAPK in cytokinesis by studying the liver of wild type mice or liver-specific p38α knock-out mice; 2) to assess the role of oxidative stress associated with hepatocyte isolation on cytokinesis. When p38α was down-regulated in hepatocytes, MK2 phosphorylation on threonine 334 was completely abrogated. Activation of MNK-1, required for abscission of the intercellular bridge, was diminished. Key proteins of the RhoA pathway (phospho-PRK2, nuclear phospho…
3D Morphology, ultrastructure and development of Ceratomyxa puntazzi stages: first insights into the mechanisms of motility and budding in the Myxozo…
2012
Free, amoeboid movement of organisms within media as well as substrate-dependent cellular crawling processes of cells and organisms require an actin cytoskeleton. This system is also involved in the cytokinetic processes of all eukaryotic cells. Myxozoan parasites are known for the disease they cause in economical important fishes. Usually, their pathology is related to rapid proliferation in the host. However, the sequences of their development are still poorly understood, especially with regard to pre-sporogonic proliferation mechanisms. The present work employs light microscopy (LM), electron microscopy (SEM, TEM) and confocal laser scanning microscopy (CLSM) in combination with specific…
De novo formation of cytokeratin filament networks originates from the cell cortex in A-431 cells
2001
Of the three major cytoskeletal filament systems, the intermediate filaments are the least understood. Since they differ fundamentally from the actin- and microtubulebased networks by their lack of polarity, it has remained a mystery how and where these principally endless filaments are formed. Using a recently established epithelial cell system in which fluorescently labeled intermediate filaments of the cytokeratin type can be monitored in living cells, we address these issues. By multidimensional time-lapse fluorescence microscopy, we examine de novo intermediate filament network formation from non-filamentous material at the end of mitosis and show that it mirrors disassembly. It is dem…
The use of morphokinetics as a predictor of embryo implantation.
2011
Background Time-lapse observation presents an opportunity for optimizing embryo selection based on morphological grading as well as providing novel kinetic parameters, which may further improve accurate selection of viable embryos. The objective of this retrospective study was to identify the morphokinetic parameters specific to embryos that were capable of implanting. In order to compare a large number of embryos, with minimal variation in culture conditions, we have used an automatic embryo monitoring system. Methods Using a tri-gas IVF incubator with a built-in camera designed to automatically acquire images at defined time points, we have simultaneously monitored up to 72 individual emb…
The Australian Sheep-Goat Scale: An Evaluation of Factor Structure and Convergent Validity.
2018
The Australian Sheep-Goat Scale (ASGS) is a commonly used measure of belief in the paranormal. The scale contains items that index extrasensory perception (ESP), psychokinesis (PK), and life after death (LAD). Although, research employs the ASGS as both a general (unidimensional) and factorial (multidimensional) measure, few studies have examined the appropriateness of these solutions. Accordingly, the present paper tested the psychometric integrity of the ASGS via two studies. Study 1 assessed ASGS factorial structure using confirmatory factor analysis. To achieve this, merging of ASGS data from previously published studies and ongoing work created a heterogeneous sample of 1,601 responses…
Cuantificación de la calidad embrionaria mediante el consumo de oxígeno durante el proceso rutinario de incubación y desarrollo in vitro
2015
A pesar de la aplicación intensiva de las TRA y de las cada vez mayores tasas de éxito, hay ciertos aspectos de estos tratamientos que continúan sin resolverse, siendo una limitación importante el hecho de que sólo entre el 10-20% de los embriones transferidos al útero sean capaces de dar lugar a un embarazo a término. Esta limitación está promoviendo el desarrollo de nuevas técnicas no invasivas para seleccionar embriones más eficazmente que mediante el mero criterio morfológico. Las evidencias apoyadas por distintos trabajos encontrados en la literatura hacen que consideremos algunos métodos no invasivos, como la actividad metabólica de ovocitos y embriones, como buenos predictores de la …
Leukotriene B4-loaded microspheres: a new therapeutic strategy to modulate cell activation
2008
AbstractBackgroundLeukotriene B4(LTB4) is a potent inflammatory mediator that also stimulates the immune response. In addition, it promotes polymorphonuclear leukocyte phagocytosis, chemotaxis, chemokinesis and modulates cytokines release. Regarding chemical instability of the leukotriene molecule, in the present study we assessed the immunomodulatory activities conferred by LTB4released from microspheres (MS). A previous oil-in-water emulsion solvent extraction-evaporation method was chosen to prepare LTB4-loaded MS.ResultsIn the mice cremasteric microcirculation, intraescrotal injection of 0.1 ml of LTB4-loaded MS provoked significant increases in leukocyte rolling flux, adhesion and emig…