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Cellular Patterns (cellular + pattern)
Selected AbstractsCellular patterns in the inner retina of adult zebrafish: Quantitative analyses and a computational model of their formationTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2004David A. Cameron Abstract The mechanisms that control cellular pattern formation in the growing vertebrate central nervous system are poorly understood. In an effort to reveal mechanistic rules of cellular pattern formation in the central nervous system, quantitative spatial analysis and computational modeling techniques were applied to cellular patterns in the inner retina of the adult zebrafish. All the analyzed cell types were arrayed in nonrandom patterns tending toward regularity; specifically, they were locally anticlustered. Over relatively large spatial scales, only one cell type exhibited consistent evidence for pattern regularity, suggesting that cellular pattern formation in the inner retina is dominated by local anticlustering mechanisms. Cross-correlation analyses revealed independence between the patterns of different cell types, suggesting that cellular pattern formation may involve multiple, independent, homotypic anticlustering mechanisms. A computational model of cellular pattern formation in the growing zebrafish retina was developed, which featured an inhibitory, homotypic signaling mechanism, arising from differentiated cells, that controlled the spatial profile of cell fate decisions. By adjusting the spatial profile of this decaying-exponential signal, the model provided good estimates of all the cellular patterns that were observed in vivo, as objectively judged by quantitative spatial pattern analyses. The results support the hypothesis that cellular pattern formation in the inner retina of zebrafish is dominated by a set of anticlustering mechanisms that may control events at, or near, the spatiotemporal point of cell fate decision. J. Comp. Neurol. 471:11,25, 2004. © 2004 Wiley-Liss, Inc. [source] Chrysophanol induces necrosis through the production of ROS and alteration of ATP levels in J5 human liver cancer cellsMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 7 2010Chi-Cheng Lu Abstract Anthraquinone compounds have been shown to induce apoptosis in different cancer cell types. Effects of chrysophanol, an anthraquinone compound, on cancer cell death have not been well studied. The goal of this study was to examine if chrysophanol had cytotoxic effects and if such effects involved apoptosis or necrosis in J5 human liver cancer cells. Chrysophanol induced necrosis in J5 cells in a dose- and time-dependent manner. Non-apoptotic cell death was induced by chrysophanol in J5 cells and was characterized by caspase independence, delayed externalization of phosphatidylserine and plasma membrane disruption. Blockage of apoptotic induction by a general caspase inhibitor (z-VAD-fmk) failed to protect cells against chrysophanol-induced cell death. The levels of reactive oxygen species production and loss of mitochondrial membrane potential (,,m) were also determined to assess the effects of chrysophanol. However, reductions in adenosine triphosphate levels and increases in lactate dehydrogenase activity indicated that chrysophanol stimulated necrotic cell death. In summary, human liver cancer cells treated with chrysophanol exhibited a cellular pattern associated with necrosis and not apoptosis. [source] An idealized numerical simulation of mammatus-like cloudsATMOSPHERIC SCIENCE LETTERS, Issue 1 2006Katharine M. Kanak Abstract A three-dimensional numerical simulation of mammatus-like clouds is presented. A portion of a cirrus outflow anvil cloud is simulated including cloud ice and snow microphysical representations. The simulated mammatus clouds appear in a cellular pattern and are compared with the few available previously published physical observations of mammatus. Copyright © 2006 Royal Meteorological Society [source] Ecological correlates of body size in relation to cell size and cell number: patterns in flies, fish, fruits and foliageBIOLOGICAL REVIEWS, Issue 2 2007Jeff Arendt Abstract Body size is important to most aspects of biology and is also one of the most labile traits. Despite its importance we know remarkably little about the proximate (developmental) factors that determine body size under different circumstances. Here, I review what is known about how cell size and number contribute to phenetic and genetic variation in body size in Drosophila melanogaster, several fish, and fruits and leaves of some angiosperms. Variation in resources influences size primarily through changes in cell number while temperature acts through cell size. The difference in cellular mechanism may also explain the differences in growth trajectories resulting from food and temperature manipulations. There is, however, a poorly recognized interaction between food and temperature effects that needs further study. In addition, flies show a sexual dimorphism in temperature effects with the larger sex responding by changes in cell size and the smaller sex showing changes in both cell size and number. Leaf size is more variable than other organs, but there appears to be a consistent difference between how shade-tolerant and shade-intolerant species respond to light level. The former have larger leaves via cell size under shade, the latter via cell number in light conditions. Genetic differences, primarily from comparisons of D. melanogaster, show similar variation. Direct selection on body size alters cell number only, while temperature selection results in increased cell size and decreased cell number. Population comparisons along latitudinal clines show that larger flies have both larger cells and more cells. Use of these proximate patterns can give clues as to how selection acts in the wild. For example, the latitudinal pattern in D. melanogaster is usually assumed to be due to temperature, but the cellular pattern does not match that seen in laboratory selection at different temperatures. [source] Endometrial glandular and stromal breakdown, part 1: Cytomorphological appearanceDIAGNOSTIC CYTOPATHOLOGY, Issue 9 2006C.M.I.A.C., Keiko Shimizu C.T. Abstract Endometrial carcinoma is the most common invasive neoplasm of the female reproductive tract. Early detection and accurate diagnosis of these lesions and its precursor by endometrial cytology is now accepted in Japan and regarded as an effective primary method of evaluating endometrial pathology (atypical hyperplasia or carcinoma). Careful cytomorphologic evaluation of the abnormal endometrial lesions has made possible an accurate and reproducible microscopic assessment. The current study was conducted to determine the significance of endometrial cytology on disordered endometrium associated with anovulation when compared with endometrial hyperplasia. From January 1998 through April 2004, 144 cases on which histopathological diagnoses were obtained by endometrial curettage after taken direct endometrial sample by Endocyte. The materials comprise 49 cases of normal proliferative endometrium, and 63 cases of endometrial hyperplasia without atypia were prepared as control cases. The cytomorphology was examined involving so-called endometrial glandular and stromal breakdown (EGBD). EGBD cases evidenced significant numbers of stromal cells condensed and formed compact nests with hyperchromatic nuclei and little or no cytoplasm. They were often associated with fragmented clusters of endometrial glands with condensed cluster of stromal cells. Both the fragmented cluster of endometrial glands and condensed cluster of stromal cells are a characteristic cytologic feature of EGBD endometrium on the cyto-architectural diagnosis. The combination of these cellular patterns is highly specific to this abnormal pathological condition in EGBD endometrium. To improve the accuracy of the cytodiagnosis, it is important that the cytology of the EGBD endometrium should be diagnosed negative; as a result, we can achieve successful endometrial cytology with cyto-architectural criteria for the endometrial pathology. Diagn. Cytopathol. 2006;34:609,613. © 2006 Wiley,Liss, Inc. [source] Extracellular biology of Myxococcus xanthusFEMS MICROBIOLOGY REVIEWS, Issue 2 2010Anna Konovalova Abstract Myxococcus xanthus has a lifecycle characterized by several social interactions. In the presence of prey, M. xanthus is a predator forming cooperatively feeding colonies, and in the absence of nutrients, M. xanthus cells interact to form multicellular, spore-filled fruiting bodies. Formation of both cellular patterns depends on extracellular functions including the extracellular matrix and intercellular signals. Interestingly, the formation of these patterns also depends on several activities that involve direct cell,cell contacts between M. xanthus cells or direct contacts between M. xanthus cells and the substratum, suggesting that M. xanthus cells have a marked ability to distinguish self from nonself. Genome-wide analyses of the M. xanthus genome reveal a large potential for protein secretion. Myxococcus xanthus harbours all protein secretion systems required for translocation of unfolded and folded proteins across the cytoplasmic membrane and an intact type II secretion system. Moreover, M. xanthus contains 60 ATP-binding cassette transporters, two degenerate type III secretion systems, both of which lack the parts in the outer membrane and the needle structure, and an intact type VI secretion system for one-step translocation of proteins across the cell envelope. Also, analyses of the M. xanthus proteome reveal a large protein secretion potential including many proteins of unknown function. [source] Cellular patterns in the inner retina of adult zebrafish: Quantitative analyses and a computational model of their formationTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2004David A. Cameron Abstract The mechanisms that control cellular pattern formation in the growing vertebrate central nervous system are poorly understood. In an effort to reveal mechanistic rules of cellular pattern formation in the central nervous system, quantitative spatial analysis and computational modeling techniques were applied to cellular patterns in the inner retina of the adult zebrafish. All the analyzed cell types were arrayed in nonrandom patterns tending toward regularity; specifically, they were locally anticlustered. Over relatively large spatial scales, only one cell type exhibited consistent evidence for pattern regularity, suggesting that cellular pattern formation in the inner retina is dominated by local anticlustering mechanisms. Cross-correlation analyses revealed independence between the patterns of different cell types, suggesting that cellular pattern formation may involve multiple, independent, homotypic anticlustering mechanisms. A computational model of cellular pattern formation in the growing zebrafish retina was developed, which featured an inhibitory, homotypic signaling mechanism, arising from differentiated cells, that controlled the spatial profile of cell fate decisions. By adjusting the spatial profile of this decaying-exponential signal, the model provided good estimates of all the cellular patterns that were observed in vivo, as objectively judged by quantitative spatial pattern analyses. The results support the hypothesis that cellular pattern formation in the inner retina of zebrafish is dominated by a set of anticlustering mechanisms that may control events at, or near, the spatiotemporal point of cell fate decision. J. Comp. Neurol. 471:11,25, 2004. © 2004 Wiley-Liss, Inc. [source] Patterning of diverse mammalian cell types in serum free medium with photoablationBIOTECHNOLOGY PROGRESS, Issue 2 2009Vipra Dhir Abstract Integration of living cells with novel microdevices requires the development of innovative technologies for manipulating cells. Chemical surface patterning has been proven as an effective method to control the attachment and growth of diverse cell populations. Patterning polyelectrolyte multilayers through the combination of layer-by-layer self-assembly technique and photolithography offer a simple, versatile, and silicon compatible approach that overcomes chemical surface patterning limitations, such as short-term stability and low-protein adsorption resistance. In this study, direct photolithographic patterning of two types of multilayers, PAA (poly acrylic acid)/PAAm (poly acryl amide) and PAA/PAH (poly allyl amine hydrochloride), were developed to pattern mammalian neuronal, skeletal, and cardiac muscle cells. For all studied cell types, PAA/PAAm multilayers behaved as a cytophobic surface, completely preventing cell attachment. In contrast, PAA/PAH multilayers have shown a cell-selective behavior, promoting the attachment and growth of neuronal cells (embryonic rat hippocampal and NG108-15 cells) to a greater extent, while providing little attachment for neonatal rat cardiac and skeletal muscle cells (C2C12 cell line). PAA/PAAm multilayer cellular patterns have also shown a remarkable protein adsorption resistance. Protein adsorption protocols commonly used for surface treatment in cell culture did not compromise the cell attachment inhibiting feature of the PAA/PAAm multilayer patterns. The combination of polyelectrolyte multilayer patterns with different adsorbed proteins could expand the applicability of this technology to cell types that require specific proteins either on the surface or in the medium for attachment or differentiation, and could not be patterned using the traditional methods. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] | ||||||||||