PRMT7 Preserves Satellite Cell Regenerative Capacity

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Roméo Sébastien Blanc

2016-02-01

Full Text Available Regeneration of skeletal muscle requires the continued presence of quiescent muscle stem cells (satellite cells, which become activated in response to injury. Here, we report that whole-body protein arginine methyltransferase PRMT7−/− adult mice and mice conditionally lacking PRMT7 in satellite cells using Pax7-CreERT2 both display a significant reduction in satellite cell function, leading to defects in regenerative capacity upon muscle injury. We show that PRMT7 is preferentially expressed in activated satellite cells and, interestingly, PRMT7-deficient satellite cells undergo cell-cycle arrest and premature cellular senescence. These defects underlie poor satellite cell stem cell capacity to regenerate muscle and self-renew after injury. PRMT7-deficient satellite cells express elevated levels of the CDK inhibitor p21CIP1 and low levels of its repressor, DNMT3b. Restoration of DNMT3b in PRMT7-deficient cells rescues PRMT7-mediated senescence. Our findings define PRMT7 as a regulator of the DNMT3b/p21 axis required to maintain muscle stem cell regenerative capacity.

Appearance of differentiated cells derived from polar body nuclei in the silkworm, Bombyx mori

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Hiroki eSakai

2013-09-01

Full Text Available AbstractIn Bombyx mori, polar body nuclei are observed until 9h after egg lying, however, the fate of polar body nuclei remains unclear. To examine the fate of polar body nuclei, we employed a mutation of serosal cell pigmentation, pink-eyed white egg (pe. The heterozygous pe/+pe females produced black serosal cells in white eggs, while pe/pe females did not produce black serosal cells in white eggs. These results suggest that the appearance of black serosal cells in white eggs depends on the genotype (pe/ +pe of the mother. Because the polar body nuclei had +pe genes in the white eggs laid by a pe/ +pe female, polar body nuclei participate in development and differentiate into functional cell (serosal cells. Analyses of serosal cells pigmentation indicated that approximately 30% of the eggs contained polar-body-nucleus-derived cells. These results demonstrate that polar-body-nucleus-derived cells appeared at a high frequency under natural conditions. Approximately 80% of polar-body-nucleus-derived cells appeared near the anterior pole and the dorsal side, which is opposite to where embryogenesis occurs. The number of cells derived from the polar body nuclei was very low. Approximately 26 % of these eggs contained only one black serosal cell. PCR-based analysis revealed that the polar-body-nucleus-derived cells disappeared in late embryonic stages (stage 25. Overall, polar-body-nuclei-derived cells were unlikely to contribute to embryos.

Satellite cells in human skeletal muscle plasticity

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Tim eSnijders

2015-10-01

Full Text Available Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodelling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodelling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodelling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

Satellite cells in human skeletal muscle plasticity.

Science.gov (United States)

Snijders, Tim; Nederveen, Joshua P; McKay, Bryon R; Joanisse, Sophie; Verdijk, Lex B; van Loon, Luc J C; Parise, Gianni

2015-01-01

Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodeling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodeling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodeling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

Regulation of satellite cell function in sarcopenia

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Stephen E Alway

2014-09-01

Full Text Available The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell function that is impacted by the environment (niche of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse or rehabilitation in sarcopenic muscles. Nutritional intervention provides one therapeutic strategy to improve the satellite cell niche and systemic factors, with the goal of improving satellite cell function in aging muscles. Although many elderly persons consume various nutraceuticals with the hope of improving health, most of these compounds have not been thoroughly tested, and the impacts that they might have on sarcopenia, and satellite cell function are not clear. This review discusses data pertaining to the satellite cell responses and function in aging skeletal muscle, and the impact that three compounds: resveratrol, green tea catechins and β-Hydroxy-β-methylbutyrate have on regulating satellite cell function and therefore contributing to reducing sarcopenia or improving muscle mass after disuse in aging. The data suggest that these nutraceutical compounds improve satellite cell function during rehabilitative loading in animal models of aging after disuse (i.e., muscle regeneration. While these compounds have not been rigorously tested in humans, the data from animal models of aging provide a strong basis for conducting additional focused work to determine if these or other nutraceuticals can offset the muscle losses, or improve regeneration in sarcopenic muscles of older humans via improving satellite cell function.

Regulation of Satellite Cell Function in Sarcopenia

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Alway, Stephen E.; Myers, Matthew J.; Mohamed, Junaith S.

2014-01-01

The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell) function that is impacted by the environment (niche) of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse, or rehabilitation in sarcopenic muscles. Nutritional intervention provides one therapeutic strategy to improve the satellite cell niche and systemic factors, with the goal of improving satellite cell function in aging muscles. Although many elderly persons consume various nutraceuticals with the hope of improving health, most of these compounds have not been thoroughly tested, and the impacts that they might have on sarcopenia and satellite cell function are not clear. This review discusses data pertaining to the satellite cell responses and function in aging skeletal muscle, and the impact that three compounds: resveratrol, green tea catechins, and β-Hydroxy-β-methylbutyrate have on regulating satellite cell function and therefore contributing to reducing sarcopenia or improving muscle mass after disuse in aging. The data suggest that these nutraceutical compounds improve satellite cell function during rehabilitative loading in animal models of aging after disuse (i.e., muscle regeneration). While these compounds have not been rigorously tested in humans, the data from animal models of aging provide a strong basis for conducting additional focused work to determine if these or other nutraceuticals can offset the muscle losses, or improve regeneration in sarcopenic muscles of older humans via improving satellite cell function. PMID:25295003

Automatic segmentation of cell nuclei from confocal laser scanning microscopy images

International Nuclear Information System (INIS)

Kelemen, A.; Reist, H.W.

1997-01-01

A newly developed experimental method combines the possibility of irradiating more than a thousand cells simultaneous with an efficient colony-forming ability and with the capability of localizing a particle track through a cell nucleus together with the assessment of the energy transfer by digital superposition of the image containing the track with that of the cells. To assess the amount of energy deposition by particles traversing the cell nucleus the intersection lengths of the particle tracks have to be known. Intersection lengths can be obtained by determining the 3D surface contours of the irradiated cell nuclei. Confocal laser scanning microscopy using specific DNA fluorescent dye offers a possible way for the determination of the 3D shape of individual nuclei. Unfortunately, such experiments cannot be performed on living cells. One solution to this problem can be provided by building a statistical model of the shape of the nuclei of the exposed cells. In order to build such a statistical model, a large number of cell nuclei have to be identified and segmented from confocal laser scanning microscopy images. The present paper describes a method to perform this 3D segmentation in an automatic manner in order to create a solid basis for the statistical model. (author) 2 figs., 4 refs

Preparing nuclei from cells in monolayer cultures suitable for counting and for following synchronized cells through the cell cycle.

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Butler, W B

1984-08-15

A procedure is described for preparing nuclei from cells in monolayer culture so that they may be counted using an electronic particle counter. It takes only 10 to 15 min, and consists of swelling the cells in hypotonic buffer and then lysing them with the quaternary ammonium salt, ethylhexadecyldimethylammonium bromide. The cells are completely lysed, yielding a suspension of clean single nuclei which is stable, free of debris, and easily counted. The method was developed for a cell line of epithelial origin (MCF-7), which is often difficult to trypsinize to single cells. It works equally well at all cell densities up to and beyond confluence, and has been used with a variety of cells in culture, including 3T3 cells, bovine macrophages, rat mammary epithelial cells, mouse mammary tumor cell lines, and human fibroblasts. The size of the nuclei produced by this procedure is related to their DNA content, and the method is thus suitable for following cultures of synchronized cells through the cell cycle, and for performing differential counts of cells with substantial differences in DNA content.

Statistics of hits to bone cell nuclei

International Nuclear Information System (INIS)

Kruglikov, I.L.; Polig, E.; Jee, W.S.S.

1993-01-01

The statistics of hits to the nuclei of bone cells irradiated from alpha sources labeling bone tissue is described. It is shown that the law of remodeling of a bone structural unit (BSU), which describes the distribution of quiescence periodes of this unit, affects the statistics of hits. It the irradiation of bone cells occurs during the whole cell cycle, the mean number of hits is independent of the law of remodeling. In this case the variance of hits has the minimum value for constant quiescence periods of BSUs (deterministic remodeling) and the maximum value for exponentially distributed quiescence periods (random remodeling). For the first generation of bone cells, i.e. for the cells which existed at the moment of the uptake of the nuclide, the mean number of hits depends on the law of remodeling. For random remodeling the mean number is equal to the mean value for the complete remodeling cycle. For deterministic remodeling the mean is only half this value. For the first generation of bone cells, changing the law of remodeling from random to deterministic increases the probability of no hits to the nuclei of bone cells. For the same mean value of hits, the difference does not exceed 13.3% of the total number of cells. For the subsequent generations of bone cells, such a change of the law of remodeling decreases the probability of no hits up to 20.4% of the total number of cells. (orig.)

Cell nuclei segmentation in fluorescence microscopy images using inter- and intra-region discriminative information.

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Song, Yang; Cai, Weidong; Feng, David Dagan; Chen, Mei

2013-01-01

Automated segmentation of cell nuclei in microscopic images is critical to high throughput analysis of the ever increasing amount of data. Although cell nuclei are generally visually distinguishable for human, automated segmentation faces challenges when there is significant intensity inhomogeneity among cell nuclei or in the background. In this paper, we propose an effective method for automated cell nucleus segmentation using a three-step approach. It first obtains an initial segmentation by extracting salient regions in the image, then reduces false positives using inter-region feature discrimination, and finally refines the boundary of the cell nuclei using intra-region contrast information. This method has been evaluated on two publicly available datasets of fluorescence microscopic images with 4009 cells, and has achieved superior performance compared to popular state of the art methods using established metrics.

The role of satellite cells in muscle hypertrophy.

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Blaauw, Bert; Reggiani, Carlo

2014-02-01

The role of satellite cells in muscle hypertrophy has long been a debated issue. In the late 1980s it was shown that proteins remain close to the myonucleus responsible for its synthesis, giving rise to the idea of a nuclear domain. This, together with the observation that during various models of muscle hypertrophy there is an activation of the muscle stem cells, i.e. satellite cells, lead to the idea that satellite cell activation is required for muscle hypertrophy. Thus, satellite cells are not only responsible for muscle repair and regeneration, but also for hypertrophic growth. Further support for this line of thinking was obtained after studies showing that irradiation of skeletal muscle, and therefore elimination of all satellite cells, completely prevented overload-induced hypertrophy. Recently however, using different transgenic approaches, it has become clear that muscle hypertrophy can occur without a contribution of satellite cells, even though in most situations of muscle hypertrophy satellite cells are activated. In this review we will discuss the contribution of satellite cells, and other muscle-resident stem cells, to muscle hypertrophy both in mice as well as in humans.

Pervasive satellite cell contribution to uninjured adult muscle fibers.

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Pawlikowski, Bradley; Pulliam, Crystal; Betta, Nicole Dalla; Kardon, Gabrielle; Olwin, Bradley B

2015-01-01

Adult skeletal muscle adapts to functional needs, maintaining consistent numbers of myonuclei and stem cells. Although resident muscle stem cells or satellite cells are required for muscle growth and repair, in uninjured muscle, these cells appear quiescent and metabolically inactive. To investigate the satellite cell contribution to myofibers in adult uninjured skeletal muscle, we labeled satellite cells by inducing a recombination of LSL-tdTomato in Pax7(CreER) mice and scoring tdTomato+ myofibers as an indicator of satellite cell fusion. Satellite cell fusion into myofibers plateaus postnatally between 8 and 12 weeks of age, reaching a steady state in hindlimb muscles, but in extra ocular or diaphragm muscles, satellite cell fusion is maintained at postnatal levels irrespective of the age assayed. Upon recombination and following a 2-week chase in 6-month-old mice, tdTomato-labeled satellite cells fused into myofibers as 20, 50, and 80 % of hindlimb, extra ocular, and diaphragm myofibers, respectively, were tdTomato+. Satellite cells contribute to uninjured myofibers either following a cell division or directly without an intervening cell division. The frequency of satellite cell fusion into the skeletal muscle fibers is greater than previously estimated, suggesting an important functional role for satellite cell fusion into adult myofibers and a requirement for active maintenance of satellite cell numbers in uninjured skeletal muscle.

Study and modeling of the most energetic Active Galactic Nuclei with the Fermi satellite; Etude et modelisation des noyaux actifs de galaxie les plus energetiques avec le satellite Fermi

Energy Technology Data Exchange (ETDEWEB)

Sanchez, D.

2010-06-15

The Fermi satellite was launched in June 2008. The onboard LAT detector is dedicated to the study of galactic and extra-galactic gamma sources with an energy comprised between 200 MeV and 300 GeV. 1451 sources have been detected in less than 11 months. This document is divided into 6 chapters: 1) gamma astronomy, 2) the Fermi satellite, 3) the active galactic nuclei (NAG), 4) the observation of several blazars (PKS-2155-304 and PG-1553+113) and its simulation, 5) the observation of PKS-2155-304 with both RXTE and Fermi, and 6) conclusion

Vertical uniformity of cells and nuclei in epithelial monolayers.

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Neelam, Srujana; Hayes, Peter Robert; Zhang, Qiao; Dickinson, Richard B; Lele, Tanmay P

2016-01-22

Morphological variability in cytoskeletal organization, organelle position and cell boundaries is a common feature of cultured cells. Remarkable uniformity and reproducibility in structure can be accomplished by providing cells with defined geometric cues. Cells in tissues can also self-organize in the absence of directing extracellular cues; however the mechanical principles for such self-organization are not understood. We report that unlike horizontal shapes, the vertical shapes of the cell and nucleus in the z-dimension are uniform in cells in cultured monolayers compared to isolated cells. Apical surfaces of cells and their nuclei in monolayers were flat and heights were uniform. In contrast, isolated cells, or cells with disrupted cell-cell adhesions had nuclei with curved apical surfaces and variable heights. Isolated cells cultured within micron-sized square wells displayed flat cell and nuclear shapes similar to cells in monolayers. Local disruption of nuclear-cytoskeletal linkages resulted in spatial variation in vertical uniformity. These results suggest that competition between cell-cell pulling forces that expand and shorten the vertical cell cross-section, thereby widening and flattening the nucleus, and the resistance of the nucleus to further flattening results in uniform cell and nuclear cross-sections. Our results reveal the mechanical principles of self-organized vertical uniformity in cell monolayers.

BMP signaling regulates satellite cell-dependent postnatal muscle growth.

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Stantzou, Amalia; Schirwis, Elija; Swist, Sandra; Alonso-Martin, Sonia; Polydorou, Ioanna; Zarrouki, Faouzi; Mouisel, Etienne; Beley, Cyriaque; Julien, Anaïs; Le Grand, Fabien; Garcia, Luis; Colnot, Céline; Birchmeier, Carmen; Braun, Thomas; Schuelke, Markus; Relaix, Frédéric; Amthor, Helge

2017-08-01

Postnatal growth of skeletal muscle largely depends on the expansion and differentiation of resident stem cells, the so-called satellite cells. Here, we demonstrate that postnatal satellite cells express components of the bone morphogenetic protein (BMP) signaling machinery. Overexpression of noggin in postnatal mice (to antagonize BMP ligands), satellite cell-specific knockout of Alk3 (the gene encoding the BMP transmembrane receptor) or overexpression of inhibitory SMAD6 decreased satellite cell proliferation and accretion during myofiber growth, and ultimately retarded muscle growth. Moreover, reduced BMP signaling diminished the adult satellite cell pool. Abrogation of BMP signaling in satellite cell-derived primary myoblasts strongly diminished cell proliferation and upregulated the expression of cell cycle inhibitors p21 and p57 In conclusion, these results show that BMP signaling defines postnatal muscle development by regulating satellite cell-dependent myofiber growth and the generation of the adult muscle stem cell pool. © 2017. Published by The Company of Biologists Ltd.

Isolation of cell nuclei using inert macromolecules to mimic the crowded cytoplasm.

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Ronald Hancock

Full Text Available Cell nuclei are commonly isolated and studied in media which include millimolar concentrations of cations, which conserve the nuclear volume by screening the negative charges on chromatin and maintaining its compaction. However, two factors question if these ionic conditions correctly reproduce the environment of nuclei in vivo: the small-scale motion and conformation of chromatin in vivo are not reproduced in isolated nuclei, and experiments and theory suggest that small ions in the cytoplasm are not free in the soluble phase but are predominantly bound to macromolecules. We studied the possible role in maintaining the structure and functions of nuclei in vivo of a further but frequently overlooked property of the cytoplasm, the crowding or osmotic effects caused by diffusible macromolecules whose concentration, measured in several studies, is in the range of 130 mg/ml. Nuclei which conserved their volume in the cell and their ultrastructure seen by electron microscopy were released from K562 cells in media containing the inert polymer 70 kDa Ficoll (50% w/v or 70 kDa dextran (35% w/v to replace the diffusible cytoplasmic molecules which were dispersed on cell lysis with digitonin, with 100 microM K-Hepes buffer as the only source of ions. Immunofluorescence labelling and experiments using cells expressing GFP-fusion proteins showed that internal compartments (nucleoli, PML and coiled bodies, foci of RNA polymerase II were conserved in these nuclei, and nascent RNA transcripts could be elongated. Our observations are consistent with the hypothesis that crowding by diffusible cytoplasmic macromolecules is a crucial but overlooked factor which supports the nucleus in vivo by equilibrating the opposing osmotic pressure cause by the high concentration of macromolecules in the nucleus, and suggest that crowded media provide more physiological conditions to study nuclear structure and functions. They may also help to resolve the long-standing paradox

Using cell nuclei features to detect colon cancer tissue in hematoxylin and eosin stained slides.

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Jørgensen, Alex Skovsbo; Rasmussen, Anders Munk; Andersen, Niels Kristian Mäkinen; Andersen, Simon Kragh; Emborg, Jonas; Røge, Rasmus; Østergaard, Lasse Riis

2017-08-01

Currently, diagnosis of colon cancer is based on manual examination of histopathological images by a pathologist. This can be time consuming and interpretation of the images is subject to inter- and intra-observer variability. This may be improved by introducing a computer-aided diagnosis (CAD) system for automatic detection of cancer tissue within whole slide hematoxylin and eosin (H&E) stains. Cancer disrupts the normal control mechanisms of cell proliferation and differentiation, affecting the structure and appearance of the cells. Therefore, extracting features from segmented cell nuclei structures may provide useful information to detect cancer tissue. A framework for automatic classification of regions of interest (ROI) containing either benign or cancerous colon tissue extracted from whole slide H&E stained images using cell nuclei features was proposed. A total of 1,596 ROI's were extracted from 87 whole slide H&E stains (44 benign and 43 cancer). A cell nuclei segmentation algorithm consisting of color deconvolution, k-means clustering, local adaptive thresholding, and cell separation was performed within the ROI's to extract cell nuclei features. From the segmented cell nuclei structures a total of 750 texture and intensity-based features were extracted for classification of the ROI's. The nine most discriminative cell nuclei features were used in a random forest classifier to determine if the ROI's contained benign or cancer tissue. The ROI classification obtained an area under the curve (AUC) of 0.96, sensitivity of 0.88, specificity of 0.92, and accuracy of 0.91 using an optimized threshold. The developed framework showed promising results in using cell nuclei features to classify ROIs into containing benign or cancer tissue in H&E stained tissue samples. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

"Known Unknowns": Current Questions in Muscle Satellite Cell Biology.

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Cornelison, Ddw

2018-01-01

Our understanding of satellite cells, now known to be the obligate stem cells of skeletal muscle, has increased dramatically in recent years due to the introduction of new molecular, genetic, and technical resources. In addition to their role in acute repair of damaged muscle, satellite cells are of interest in the fields of aging, exercise, neuromuscular disease, and stem cell therapy, and all of these applications have driven a dramatic increase in our understanding of the activity and potential of satellite cells. However, many fundamental questions of satellite cell biology remain to be answered, including their emergence as a specific lineage, the degree and significance of heterogeneity within the satellite cell population, the roles of their interactions with other resident and infiltrating cell types during homeostasis and regeneration, and the relative roles of intrinsic vs extrinsic factors that may contribute to satellite cell dysfunction in the context of aging or disease. This review will address the current state of these open questions in satellite cell biology. © 2018 Elsevier Inc. All rights reserved.

Leucocytes, cytokines and satellite cells

DEFF Research Database (Denmark)

Paulsen, Gøran; Mikkelsen, Ulla Ramer; Raastad, Truls

2012-01-01

uncertain. The COX enzymes regulate satellite cell activity, as demonstrated in animal models; however the roles of the COX enzymes in human skeletal muscle need further investigation. We suggest using the term 'muscle damage' with care. Comparisons between studies and individuals must consider changes......-damaging exercise', primarily eccentric exercise. We review the evidence for the notion that the degree of muscle damage is related to the magnitude of the cytokine response. In the third and final section, we look at the satellite cell response to a single bout of eccentric exercise, as well as the role...... variation in individual responses to a given exercise should, however be expected. The link between cytokine and satellite cell responses and exercise-induced muscle damage is not so clear The systemic cytokine response may be linked more closely to the metabolic demands of exercise rather than muscle...

TAK1 modulates satellite stem cell homeostasis and skeletal muscle repair

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Ogura, Yuji; Hindi, Sajedah M.; Sato, Shuichi; Xiong, Guangyan; Akira, Shizuo; Kumar, Ashok

2015-01-01

Satellite cells are resident adult stem cells that are required for regeneration of skeletal muscle. However, signalling mechanisms that regulate satellite cell function are less understood. Here we demonstrate that transforming growth factor-β-activated kinase 1 (TAK1) is important in satellite stem cell homeostasis and function. Inactivation of TAK1 in satellite cells inhibits muscle regeneration in adult mice. TAK1 is essential for satellite cell proliferation and its inactivation causes precocious differentiation. Moreover, TAK1-deficient satellite cells exhibit increased oxidative stress and undergo spontaneous cell death, primarily through necroptosis. TAK1 is required for the activation of NF-κB and JNK in satellite cells. Forced activation of NF-κB improves survival and proliferation of TAK1-deficient satellite cells. Furthermore, TAK1-mediated activation of JNK is essential to prevent oxidative stress and precocious differentiation of satellite cells. Collectively, our study suggests that TAK1 is required for maintaining the pool of satellite stem cells and for regenerative myogenesis. PMID:26648529

Reduced satellite cell number in situ in muscular contractures from children with cerebral palsy.

Science.gov (United States)

Dayanidhi, Sudarshan; Dykstra, Peter B; Lyubasyuk, Vera; McKay, Bryon R; Chambers, Henry G; Lieber, Richard L

2015-07-01

Satellite cells (SC) are quiescent adult muscle stem cells critical for postnatal development. Children with cerebral palsy have impaired muscular growth and develop contractures. While flow cytometry previously demonstrated a reduced SC population, extracellular matrix abnormalities may influence the cell isolation methods used, systematically isolating fewer cells from CP muscle and creating a biased result. Consequently, the purpose of this study was to use immunohistochemistry on serial muscle sections to quantify SC in situ. Serial cross-sections from human gracilis muscle biopsies (n = 11) were labeled with fluorescent antibodies for Pax7 (SC transcriptional marker), laminin (basal lamina), and 4',6-diamidino-2-phenylindole (nuclei). Fluorescence microscopy under high magnification was used to identify SC based on labeling and location. Mean SC/100 myofibers was reduced by ∼70% (p muscle growth and apparent decreased responsiveness of CP muscle to exercise. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

HAMLET interacts with histones and chromatin in tumor cell nuclei.

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Düringer, Caroline; Hamiche, Ali; Gustafsson, Lotta; Kimura, Hiroshi; Svanborg, Catharina

2003-10-24

HAMLET is a folding variant of human alpha-lactalbumin in an active complex with oleic acid. HAMLET selectively enters tumor cells, accumulates in their nuclei and induces apoptosis-like cell death. This study examined the interactions of HAMLET with nuclear constituents and identified histones as targets. HAMLET was found to bind histone H3 strongly and to lesser extent histones H4 and H2B. The specificity of these interactions was confirmed using BIAcore technology and chromatin assembly assays. In vivo in tumor cells, HAMLET co-localized with histones and perturbed the chromatin structure; HAMLET was found associated with chromatin in an insoluble nuclear fraction resistant to salt extraction. In vitro, HAMLET bound strongly to histones and impaired their deposition on DNA. We conclude that HAMLET interacts with histones and chromatin in tumor cell nuclei and propose that this interaction locks the cells into the death pathway by irreversibly disrupting chromatin organization.

Automated segmentation and isolation of touching cell nuclei in cytopathology smear images of pleural effusion using distance transform watershed method

Science.gov (United States)

Win, Khin Yadanar; Choomchuay, Somsak; Hamamoto, Kazuhiko

2017-06-01

The automated segmentation of cell nuclei is an essential stage in the quantitative image analysis of cell nuclei extracted from smear cytology images of pleural fluid. Cell nuclei can indicate cancer as the characteristics of cell nuclei are associated with cells proliferation and malignancy in term of size, shape and the stained color. Nevertheless, automatic nuclei segmentation has remained challenging due to the artifacts caused by slide preparation, nuclei heterogeneity such as the poor contrast, inconsistent stained color, the cells variation, and cells overlapping. In this paper, we proposed a watershed-based method that is capable to segment the nuclei of the variety of cells from cytology pleural fluid smear images. Firstly, the original image is preprocessed by converting into the grayscale image and enhancing by adjusting and equalizing the intensity using histogram equalization. Next, the cell nuclei are segmented using OTSU thresholding as the binary image. The undesirable artifacts are eliminated using morphological operations. Finally, the distance transform based watershed method is applied to isolate the touching and overlapping cell nuclei. The proposed method is tested with 25 Papanicolaou (Pap) stained pleural fluid images. The accuracy of our proposed method is 92%. The method is relatively simple, and the results are very promising.

Isolation, Culture, Functional Assays, and Immunofluorescence of Myofiber-Associated Satellite Cells.

Science.gov (United States)

Vogler, Thomas O; Gadek, Katherine E; Cadwallader, Adam B; Elston, Tiffany L; Olwin, Bradley B

2016-01-01

Adult skeletal muscle stem cells, termed satellite cells, regenerate and repair the functional contractile cells in adult skeletal muscle called myofibers. Satellite cells reside in a niche between the basal lamina and sarcolemma of myofibers. Isolating single myofibers and their associated satellite cells provides a culture system that partially mimics the in vivo environment. We describe methods for isolating and culturing intact individual myofibers and their associated satellite cells from the mouse extensor digitorum longus muscle. Following dissection and isolation of individual myofibers we provide protocols for myofiber transplantation, satellite cell transfection, immune detection of satellite cell antigens, and assays to examine satellite cell self-renewal and proliferation.

Effective fiber hypertrophy in satellite cell-depleted skeletal muscle

Science.gov (United States)

McCarthy, John J.; Mula, Jyothi; Miyazaki, Mitsunori; Erfani, Rod; Garrison, Kelcye; Farooqui, Amreen B.; Srikuea, Ratchakrit; Lawson, Benjamin A.; Grimes, Barry; Keller, Charles; Van Zant, Gary; Campbell, Kenneth S.; Esser, Karyn A.; Dupont-Versteegden, Esther E.; Peterson, Charlotte A.

2011-01-01

An important unresolved question in skeletal muscle plasticity is whether satellite cells are necessary for muscle fiber hypertrophy. To address this issue, a novel mouse strain (Pax7-DTA) was created which enabled the conditional ablation of >90% of satellite cells in mature skeletal muscle following tamoxifen administration. To test the hypothesis that satellite cells are necessary for skeletal muscle hypertrophy, the plantaris muscle of adult Pax7-DTA mice was subjected to mechanical overload by surgical removal of the synergist muscle. Following two weeks of overload, satellite cell-depleted muscle showed the same increases in muscle mass (approximately twofold) and fiber cross-sectional area with hypertrophy as observed in the vehicle-treated group. The typical increase in myonuclei with hypertrophy was absent in satellite cell-depleted fibers, resulting in expansion of the myonuclear domain. Consistent with lack of nuclear addition to enlarged fibers, long-term BrdU labeling showed a significant reduction in the number of BrdU-positive myonuclei in satellite cell-depleted muscle compared with vehicle-treated muscle. Single fiber functional analyses showed no difference in specific force, Ca2+ sensitivity, rate of cross-bridge cycling and cooperativity between hypertrophied fibers from vehicle and tamoxifen-treated groups. Although a small component of the hypertrophic response, both fiber hyperplasia and regeneration were significantly blunted following satellite cell depletion, indicating a distinct requirement for satellite cells during these processes. These results provide convincing evidence that skeletal muscle fibers are capable of mounting a robust hypertrophic response to mechanical overload that is not dependent on satellite cells. PMID:21828094

Tissue-specific stem cells: Lessons from the skeletal muscle satellite cell

Science.gov (United States)

Brack, Andrew S.; Rando, Thomas A.

2012-01-01

In 1961, the satellite cell was first identified when electron microscopic examination of skeletal muscle demonstrated a cell wedged between the plasma membrane of the muscle fiber and the basement membrane. In recent years it has been conclusively demonstrated that the satellite cell is the primary cellular source for muscle regeneration and is equipped with the potential to self renew, thus functioning as a bone fide skeletal muscle stem cell (MuSC). As we move past the 50th anniversary of the satellite cell, we take this opportunity to discuss the current state of the art and dissect the unknowns in the MuSC field. PMID:22560074

Number of nuclei, mitotic activity and cell length in Cladophora sp thallus treated with cadmium and chromium

Directory of Open Access Journals (Sweden)

Monika Krajewska

2014-01-01

Full Text Available Cladophora sp., a fresh water, filamentous, multi-nucleate alga growing 16 days in the presence of cadmium and chromium at concentrations 10-4 10-8M was the subject of the experiment. Chromium ions reduced the number of nuclei and mitotic activity, and disturbed the correlation between cell length and number of nuclei, more than cadmium ions. Moreover, both tested metals caused the disappearance of cells with numerous nuclei with time of the culture. Only during the first (1-4 days of culture for both metals the concentration of 10-4M and especially of 10-8M increased the number of nuclei, mitotic index and the length of cells. Apical cells were more sensitive to metals than other thallus cells.

Protein Availability and Satellite Cell Dynamics in Skeletal Muscle.

Science.gov (United States)

Shamim, Baubak; Hawley, John A; Camera, Donny M

2018-06-01

Human skeletal muscle satellite cells are activated in response to both resistance and endurance exercise. It was initially proposed that satellite cell proliferation and differentiation were only required to support resistance exercise-induced hypertrophy. However, satellite cells may also play a role in muscle fibre remodelling after endurance-based exercise and extracellular matrix regulation. Given the importance of dietary protein, particularly branched chain amino acids, in supporting myofibrillar and mitochondrial adaptations to both resistance and endurance-based training, a greater understanding of how protein intake impacts satellite cell activity would provide further insight into the mechanisms governing skeletal muscle remodelling with exercise. While many studies have investigated the capacity for protein ingestion to increase post-exercise rates of muscle protein synthesis, few investigations have examined the role for protein ingestion to modulate satellite cell activity. Here we review the molecular mechanisms controlling the activation of satellite cells in response to mechanical stress and protein intake in both in vitro and in vivo models. We provide a mechanistic framework that describes how protein ingestion may enhance satellite activity and promote exercise adaptations in human skeletal muscle.

Refractometry of melanocyte cell nuclei using optical scatter images recorded by digital Fourier microscopy.

Science.gov (United States)

Seet, Katrina Y T; Nieminen, Timo A; Zvyagin, Andrei V

2009-01-01

The cell nucleus is the dominant optical scatterer in the cell. Neoplastic cells are characterized by cell nucleus polymorphism and polychromism-i.e., the nuclei exhibits an increase in the distribution of both size and refractive index. The relative size parameter, and its distribution, is proportional to the product of the nucleus size and its relative refractive index and is a useful discriminant between normal and abnormal (cancerous) cells. We demonstrate a recently introduced holographic technique, digital Fourier microscopy (DFM), to provide a sensitive measure of this relative size parameter. Fourier holograms were recorded and optical scatter of individual scatterers were extracted and modeled with Mie theory to determine the relative size parameter. The relative size parameter of individual melanocyte cell nuclei were found to be 16.5+/-0.2, which gives a cell nucleus refractive index of 1.38+/-0.01 and is in good agreement with previously reported data. The relative size parameters of individual malignant melanocyte cell nuclei are expected to be greater than 16.5.

Voluntary wheel running increases satellite cell abundance and improves recovery from disuse in gastrocnemius muscles from mice.

Science.gov (United States)

Brooks, Matthew J; Hajira, Ameena; Mohamed, Junaith S; Alway, Stephen E

2018-02-22

Reloading of atrophied muscles after hindlimb suspension unloading (HSU) can induce injury and prolong recovery. Low-impact exercise, such as voluntary wheel running, has been identified as a non-damaging rehabilitation therapy in rodents, but its effects on muscle function, morphology, and satellite cell activity after HSU are unclear. This study tested the hypothesis that low impact wheel running would increase satellite cell proliferation and improve recovery of muscle structure and function after HSU in mice. Young adult male and female C57BL/6 mice (n=6/group) were randomly placed into 5 groups. These included HSU without recovery (HSU), normal ambulatory recovery for 14 days after HSU (HSU+NoWR), and voluntary wheel running recovery for 14 days after HSU (HSU+WR). Two control groups were used: non-suspended mice-cage controls (Control) and voluntary wheel running controls (ControlWR). Satellite cell activation, was evaluated by providing mice 5-bromo-2'-deoxyuridine (BrdU) in their drinking water. As expected, HSU significantly reduced in vivo maximal force and decreased the in vivo fatigability and decreased type I and IIa myosin heavy chain (MHC) abundance in plantarflexor muscles. HSU+WR mice significantly improved plantarflexor fatigue resistance, increased type type I and IIa MHC abundance, increased fiber cross sectional area (CSA), and an increased the percentage of type I and IIA muscle fibers in the gastrocnemius muscle. HSU+WR mice also had a significantly greater percentage of BrdU-positive and Pax 7 positive nuclei inside muscle fibers and a greater MyoD to Pax 7 protein ratio when compared to HSU+NoWR mice. The mechanotransduction protein Yes-associated protein (YAP) was elevated with reloading after HSU, but HSU+WR had lower levels of the inactive phosphorylated YAP serine127 which may have contributed to increased satellite cell activation creased with reloading after HSU. These results indicate that voluntary wheel running increased YAP

Muscle Satellite Cell Protein Teneurin‐4 Regulates Differentiation During Muscle Regeneration

Science.gov (United States)

Ishii, Kana; Suzuki, Nobuharu; Mabuchi, Yo; Ito, Naoki; Kikura, Naomi; Fukada, So‐ichiro; Okano, Hideyuki; Takeda, Shin'ichi

2015-01-01

Abstract Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regeneration they acquire an activated stage, and initiate to proliferate and differentiate as myoblasts. The transmembrane protein teneurin‐4 (Ten‐4) is specifically expressed in the quiescent satellite cells; however, its cellular and molecular functions remain unknown. We therefore aimed to elucidate the function of Ten‐4 in muscle satellite cells. In the tibialis anterior (TA) muscle of Ten‐4‐deficient mice, the number and the size of myofibers, as well as the population of satellite cells, were reduced with/without induction of muscle regeneration. Furthermore, we found an accelerated activation of satellite cells in the regenerated Ten‐4‐deficient TA muscle. The cell culture analysis using primary satellite cells showed that Ten‐4 suppressed the progression of myogenic differentiation. Together, our findings revealed that Ten‐4 functions as a crucial player in maintaining the quiescence of muscle satellite cells. Stem Cells 2015;33:3017–3027 PMID:26013034

Use of Advanced Solar Cells for Commercial Communication Satellites

Science.gov (United States)

Bailey, Sheila G.; Landis, Geoffrey A.

1995-01-01

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

Sox2 promotes survival of satellite glial cells in vitro

International Nuclear Information System (INIS)

Koike, Taro; Wakabayashi, Taketoshi; Mori, Tetsuji; Hirahara, Yukie; Yamada, Hisao

2015-01-01

Sox2 is a transcriptional factor expressed in neural stem cells. It is known that Sox2 regulates cell differentiation, proliferation and survival of the neural stem cells. Our previous study showed that Sox2 is expressed in all satellite glial cells of the adult rat dorsal root ganglion. In this study, to examine the role of Sox2 in satellite glial cells, we establish a satellite glial cell-enriched culture system. Our culture method succeeded in harvesting satellite glial cells with the somata of neurons in the dorsal root ganglion. Using this culture system, Sox2 was downregulated by siRNA against Sox2. The knockdown of Sox2 downregulated ErbB2 and ErbB3 mRNA at 2 and 4 days after siRNA treatment. MAPK phosphorylation, downstream of ErbB, was also inhibited by Sox2 knockdown. Because ErbB2 and ErbB3 are receptors that support the survival of glial cells in the peripheral nervous system, apoptotic cells were also counted. TUNEL-positive cells increased at 5 days after siRNA treatment. These results suggest that Sox2 promotes satellite glial cell survival through the MAPK pathway via ErbB receptors. - Highlights: • We established satellite glial cell culture system. • Function of Sox2 in satellite glial cell was examined using siRNA. • Sox2 knockdown downregulated expression level of ErbB2 and ErbB3 mRNA. • Sox2 knockdown increased apoptotic satellite glial cell. • Sox2 promotes satellite glial cell survival through ErbB signaling

Sox2 promotes survival of satellite glial cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Koike, Taro, E-mail: koiket@hirakata.kmu.ac.jp; Wakabayashi, Taketoshi; Mori, Tetsuji; Hirahara, Yukie; Yamada, Hisao

2015-08-14

Sox2 is a transcriptional factor expressed in neural stem cells. It is known that Sox2 regulates cell differentiation, proliferation and survival of the neural stem cells. Our previous study showed that Sox2 is expressed in all satellite glial cells of the adult rat dorsal root ganglion. In this study, to examine the role of Sox2 in satellite glial cells, we establish a satellite glial cell-enriched culture system. Our culture method succeeded in harvesting satellite glial cells with the somata of neurons in the dorsal root ganglion. Using this culture system, Sox2 was downregulated by siRNA against Sox2. The knockdown of Sox2 downregulated ErbB2 and ErbB3 mRNA at 2 and 4 days after siRNA treatment. MAPK phosphorylation, downstream of ErbB, was also inhibited by Sox2 knockdown. Because ErbB2 and ErbB3 are receptors that support the survival of glial cells in the peripheral nervous system, apoptotic cells were also counted. TUNEL-positive cells increased at 5 days after siRNA treatment. These results suggest that Sox2 promotes satellite glial cell survival through the MAPK pathway via ErbB receptors. - Highlights: • We established satellite glial cell culture system. • Function of Sox2 in satellite glial cell was examined using siRNA. • Sox2 knockdown downregulated expression level of ErbB2 and ErbB3 mRNA. • Sox2 knockdown increased apoptotic satellite glial cell. • Sox2 promotes satellite glial cell survival through ErbB signaling.

Muscle Satellite Cell Protein Teneurin-4 Regulates Differentiation During Muscle Regeneration.

Science.gov (United States)

Ishii, Kana; Suzuki, Nobuharu; Mabuchi, Yo; Ito, Naoki; Kikura, Naomi; Fukada, So-Ichiro; Okano, Hideyuki; Takeda, Shin'ichi; Akazawa, Chihiro

2015-10-01

Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regeneration they acquire an activated stage, and initiate to proliferate and differentiate as myoblasts. The transmembrane protein teneurin-4 (Ten-4) is specifically expressed in the quiescent satellite cells; however, its cellular and molecular functions remain unknown. We therefore aimed to elucidate the function of Ten-4 in muscle satellite cells. In the tibialis anterior (TA) muscle of Ten-4-deficient mice, the number and the size of myofibers, as well as the population of satellite cells, were reduced with/without induction of muscle regeneration. Furthermore, we found an accelerated activation of satellite cells in the regenerated Ten-4-deficient TA muscle. The cell culture analysis using primary satellite cells showed that Ten-4 suppressed the progression of myogenic differentiation. Together, our findings revealed that Ten-4 functions as a crucial player in maintaining the quiescence of muscle satellite cells. © 2015 The Authors STEM CELLS published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Engineered matrices for skeletal muscle satellite cell engraftment and function.

Science.gov (United States)

Han, Woojin M; Jang, Young C; García, Andrés J

2017-07-01

Regeneration of traumatically injured skeletal muscles is severely limited. Moreover, the regenerative capacity of skeletal muscle declines with aging, further exacerbating the problem. Recent evidence supports that delivery of muscle satellite cells to the injured muscles enhances muscle regeneration and reverses features of aging, including reduction in muscle mass and regenerative capacity. However, direct delivery of satellite cells presents a challenge at a translational level due to inflammation and donor cell death, motivating the need to develop engineered matrices for muscle satellite cell delivery. This review will highlight important aspects of satellite cell and their niche biology in the context of muscle regeneration, and examine recent progresses in the development of engineered cell delivery matrices designed for skeletal muscle regeneration. Understanding the interactions of muscle satellite cells and their niche in both native and engineered systems is crucial to developing muscle pathology-specific cell- and biomaterial-based therapies. Copyright © 2016 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

Transient HIF2A inhibition promotes satellite cell proliferation and muscle regeneration.

Science.gov (United States)

Xie, Liwei; Yin, Amelia; Nichenko, Anna S; Beedle, Aaron M; Call, Jarrod A; Yin, Hang

2018-03-13

The remarkable regeneration capability of skeletal muscle depends on coordinated proliferation and differentiation of satellite cells. The self-renewal of satellite cells is critical for long-term maintenance of muscle regeneration potential. Hypoxia profoundly affects the proliferation, differentiation, and self-renewal of cultured myoblasts. However, the physiological relevance of hypoxia and hypoxia signaling in satellite cells in vivo remains largely unknown. Here, we report that satellite cells are in an intrinsic hypoxic state in vivo and express hypoxia-inducible factor 2A (HIF2A). HIF2A promotes the stemness and long-term homeostatic maintenance of satellite cells by maintaining the quiescence, increasing the self-renewal and blocking the myogenic differentiation of satellite cells. HIF2A stabilization in satellite cells cultured under normoxia augmented their engraftment potential in regenerative muscle. Reversely, HIF2A ablation led to the depletion of satellite cells and the consequent regenerative failure in the long-term. In contrast, transient pharmacological inhibition of HIF2A accelerated muscle regeneration by increasing satellite cell proliferation and differentiation. Mechanistically, HIF2A induces the quiescence/self-renewal of satellite cells by binding the promoter of Spry1 gene and activating Spry1 expression. These findings suggest that HIF2A is a pivotal mediator of hypoxia signaling in satellite cells and may be therapeutically targeted to improve muscle regeneration.

Cell nuclei and cytoplasm joint segmentation using the sliding band filter.

Science.gov (United States)

Quelhas, Pedro; Marcuzzo, Monica; Mendonça, Ana Maria; Campilho, Aurélio

2010-08-01

Microscopy cell image analysis is a fundamental tool for biological research. In particular, multivariate fluorescence microscopy is used to observe different aspects of cells in cultures. It is still common practice to perform analysis tasks by visual inspection of individual cells which is time consuming, exhausting and prone to induce subjective bias. This makes automatic cell image analysis essential for large scale, objective studies of cell cultures. Traditionally the task of automatic cell analysis is approached through the use of image segmentation methods for extraction of cells' locations and shapes. Image segmentation, although fundamental, is neither an easy task in computer vision nor is it robust to image quality changes. This makes image segmentation for cell detection semi-automated requiring frequent tuning of parameters. We introduce a new approach for cell detection and shape estimation in multivariate images based on the sliding band filter (SBF). This filter's design makes it adequate to detect overall convex shapes and as such it performs well for cell detection. Furthermore, the parameters involved are intuitive as they are directly related to the expected cell size. Using the SBF filter we detect cells' nucleus and cytoplasm location and shapes. Based on the assumption that each cell has the same approximate shape center in both nuclei and cytoplasm fluorescence channels, we guide cytoplasm shape estimation by the nuclear detections improving performance and reducing errors. Then we validate cell detection by gathering evidence from nuclei and cytoplasm channels. Additionally, we include overlap correction and shape regularization steps which further improve the estimated cell shapes. The approach is evaluated using two datasets with different types of data: a 20 images benchmark set of simulated cell culture images, containing 1000 simulated cells; a 16 images Drosophila melanogaster Kc167 dataset containing 1255 cells, stained for DNA and

Isolation, culture and biological characteristics of multipotent porcine skeletal muscle satellite cells.

Science.gov (United States)

Yang, Jinjuan; Liu, Hao; Wang, Kunfu; Li, Lu; Yuan, Hongyi; Liu, Xueting; Liu, Yingjie; Guan, Weijun

2017-12-01

Skeletal muscle has a huge regenerative potential for postnatal muscle growth and repair, which mainly depends on a kind of muscle progenitor cell population, called satellite cell. Nowadays, the majority of satellite cells were obtained from human, mouse, rat and other animals but rarely from pig. In this article, the porcine skeletal muscle satellite cells were isolated and cultured in vitro. The expression of surface markers of satellite cells was detected by immunofluorescence and RT-PCR assays. The differentiation capacity was assessed by inducing satellite cells into adipocytes, myoblasts and osteoblasts. The results showed that satellite cells isolated from porcine tibialis anterior were subcultured up to 12 passages and were positive for Pax7, Myod, c-Met, desmin, PCNA and NANOG but were negative for Myogenin. Satellite cells were also induced to differentiate into adipocytes, osteoblasts and myoblasts, respectively. These findings indicated that porcine satellite cells possess similar biological characteristics of stem cells, which may provide theoretical basis and experimental evidence for potential therapeutic application in the treatment of dystrophic muscle and other muscle injuries.

Opioid precursor protein isoform is targeted to the cell nuclei in the human brain

DEFF Research Database (Denmark)

Kononenko, Olga; Bazov, Igor; Watanabe, Hiroyuki

2017-01-01

to the cell nuclei in a model cellular system. This may be driven by bipartite nuclear localization signal (NLS) that is cryptic in the full-length PDYN molecule and becomes functional when signal peptide is truncated. Nuclear PDYN isoform was identified by western blot and radioimmunoassay in neuronal nuclei...

Inducible satellite cell depletion attenuates skeletal muscle regrowth following a scald-burn injury.

Science.gov (United States)

Finnerty, Celeste C; McKenna, Colleen F; Cambias, Lauren A; Brightwell, Camille R; Prasai, Anesh; Wang, Ye; El Ayadi, Amina; Herndon, David N; Suman, Oscar E; Fry, Christopher S

2017-11-01

Severe burns result in significant skeletal muscle cachexia that impedes recovery. Activity of satellite cells, skeletal muscle stem cells, is altered following a burn injury and likely hinders regrowth of muscle. Severe burn injury induces satellite cell proliferation and fusion into myofibres with greater activity in muscles proximal to the injury site. Conditional depletion of satellite cells attenuates recovery of myofibre area and volume following a scald burn injury in mice. Skeletal muscle regrowth following a burn injury requires satellite cell activity, underscoring the therapeutic potential of satellite cells in the prevention of prolonged frailty in burn survivors. Severe burns result in profound skeletal muscle atrophy; persistent muscle atrophy and weakness are major complications that hamper recovery from burn injury. Many factors contribute to the erosion of muscle mass following burn trauma, and we have previously shown concurrent activation and apoptosis of muscle satellite cells following a burn injury in paediatric patients. To determine the necessity of satellite cells during muscle recovery following a burn injury, we utilized a genetically modified mouse model (Pax7 CreER -DTA) that allows for the conditional depletion of satellite cells in skeletal muscle. Additionally, mice were provided 5-ethynyl-2'-deoxyuridine to determine satellite cell proliferation, activation and fusion. Juvenile satellite cell-wild-type (SC-WT) and satellite cell-depleted (SC-Dep) mice (8 weeks of age) were randomized to sham or burn injury consisting of a dorsal scald burn injury covering 30% of total body surface area. Both hindlimb and dorsal muscles were studied at 7, 14 and 21 days post-burn. SC-Dep mice had >93% depletion of satellite cells compared to SC-WT (P satellite cell proliferation and fusion. Depletion of satellite cells impaired post-burn recovery of both muscle fibre cross-sectional area and volume (P satellite cells in the aetiology of lean

Mobilisation of satellite cells following ischaemia and reperfusion in ...

African Journals Online (AJOL)

Enrique

inar is not disturbed, and migration to adjacent myofibres using tissue bridges ... or in group 2, the novel observation of the satellite cell breaking away ... satellite cells of group 1 were significantly longer than the group 2 cells .... Statistical analysis was by unpaired t-test with Welch's cor- ... or fully motile, interfibre myoblasts.

Muscle Satellite Cells: Exploring the Basic Biology to Rule Them.

Science.gov (United States)

Almeida, Camila F; Fernandes, Stephanie A; Ribeiro Junior, Antonio F; Keith Okamoto, Oswaldo; Vainzof, Mariz

2016-01-01

Adult skeletal muscle is a postmitotic tissue with an enormous capacity to regenerate upon injury. This is accomplished by resident stem cells, named satellite cells, which were identified more than 50 years ago. Since their discovery, many researchers have been concentrating efforts to answer questions about their origin and role in muscle development, the way they contribute to muscle regeneration, and their potential to cell-based therapies. Satellite cells are maintained in a quiescent state and upon requirement are activated, proliferating, and fusing with other cells to form or repair myofibers. In addition, they are able to self-renew and replenish the stem pool. Every phase of satellite cell activity is highly regulated and orchestrated by many molecules and signaling pathways; the elucidation of players and mechanisms involved in satellite cell biology is of extreme importance, being the first step to expose the crucial points that could be modulated to extract the optimal response from these cells in therapeutic strategies. Here, we review the basic aspects about satellite cells biology and briefly discuss recent findings about therapeutic attempts, trying to raise questions about how basic biology could provide a solid scaffold to more successful use of these cells in clinics.

Myostatin signals through Pax7 to regulate satellite cell self-renewal

International Nuclear Information System (INIS)

McFarlane, Craig; Hennebry, Alex; Thomas, Mark; Plummer, Erin; Ling, Nicholas; Sharma, Mridula; Kambadur, Ravi

2008-01-01

Myostatin, a Transforming Growth Factor-beta (TGF-β) super-family member, has previously been shown to negatively regulate satellite cell activation and self-renewal. However, to date the mechanism behind Myostatin function in satellite cell biology is not known. Here we show that Myostatin signals via a Pax7-dependent mechanism to regulate satellite cell self-renewal. While excess Myostatin inhibited Pax7 expression via ERK1/2 signaling, an increase in Pax7 expression was observed following both genetic inactivation and functional antagonism of Myostatin. As a result, we show that either blocking or inactivating Myostatin enhances the partitioning of the fusion-incompetent self-renewed satellite cell lineage (high Pax7 expression, low MyoD expression) from the pool of actively proliferating myogenic precursor cells. Consistent with this result, over-expression of Pax7 in C2C12 myogenic cells resulted in increased self-renewal through a mechanism which slowed both myogenic proliferation and differentiation. Taken together, these results suggest that increased expression of Pax7 promotes satellite cell self-renewal, and furthermore Myostatin may control the process of satellite cell self-renewal through regulation of Pax7. Thus we speculate that, in addition to the intrinsic factors (such as Pax7), extrinsic factors both positive and negative in nature, will play a major role in determining the stemness of skeletal muscle satellite cells

Recapitulation of Extracellular LAMININ Environment Maintains Stemness of Satellite Cells In Vitro.

Science.gov (United States)

Ishii, Kana; Sakurai, Hidetoshi; Suzuki, Nobuharu; Mabuchi, Yo; Sekiya, Ichiro; Sekiguchi, Kiyotoshi; Akazawa, Chihiro

2018-02-13

Satellite cells function as precursor cells in mature skeletal muscle homeostasis and regeneration. In healthy tissue, these cells are maintained in a state of quiescence by a microenvironment formed by myofibers and basement membrane in which LAMININs (LMs) form a major component. In the present study, we evaluated the satellite cell microenvironment in vivo and found that these cells are encapsulated by LMα2-5. We sought to recapitulate this satellite cell niche in vitro by culturing satellite cells in the presence of recombinant LM-E8 fragments. We show that treatment with LM-E8 promotes proliferation of satellite cells in an undifferentiated state, through reduced phosphorylation of JNK and p38. On transplantation into injured muscle tissue, satellite cells cultured with LM-E8 promoted the regeneration of skeletal muscle. These findings represent an efficient method of culturing satellite cells for use in transplantation through the recapitulation of the satellite cell niche using recombinant LM-E8 fragments. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Estradiol-promoted accumulation of receptor in nuclei of porcine endometrium cells. Immunogold electron microscopy of resting and estradiol-stimulated cells.

Science.gov (United States)

Sierralta, W D; Jakob, F; Thole, H; Engel, P; Jungblut, P W

1992-01-01

Endometrium was collected by curettage from castrated pigs, either untreated or exposed to estradiol in vivo by intrauterine injection, and processed for electron microscopy. The resin LR Gold was used for embedding, and sections were floated on droplets of 10 nm diameter gold particles, coated with the immunoglobulin-G1 (IgG1) fraction or its Fab2 fragment of a monospecific polyclonal antiserum raised in goats against the C-terminal half of the estradiol receptor. On average, only one gold particle per microns 2 became attached in the cytoplasmic area of untreated cells, whereas four were found over the nuclear area. These figures rose to 2-3/microns 2 and 15-26/microns 2, respectively, within 10 min after exposure to estradiol. The labeling intensities of nuclei in cell clusters and of coprocessed nuclei released from cells ruptured during curettage were identical in all situations. Nuclear pores were frequently tagged after estradiol treatment. The proportions of tagging densities in nuclei of untreated and estradiol-exposed cells corresponded to those of receptor contents measured in extracts of isolated nuclei by ligand binding. This correlation was not seen for the cytoplasmic compartment of untreated cells, the scarce tagging of which is interpreted by hidden antigenic determinants. Our morphological analyses support the conclusions drawn from biochemical data (Sierralta et al., 1992) of an estradiol-promoted translocation of receptor from the cytoplasm into the nucleus.

The Satellite Cell in Male and Female, Developing and Adult Mouse Muscle: Distinct Stem Cells for Growth and Regeneration

Science.gov (United States)

Neal, Alice; Boldrin, Luisa; Morgan, Jennifer Elizabeth

2012-01-01

Satellite cells are myogenic cells found between the basal lamina and the sarcolemma of the muscle fibre. Satellite cells are the source of new myofibres; as such, satellite cell transplantation holds promise as a treatment for muscular dystrophies. We have investigated age and sex differences between mouse satellite cells in vitro and assessed the importance of these factors as mediators of donor cell engraftment in an in vivo model of satellite cell transplantation. We found that satellite cell numbers are increased in growing compared to adult and in male compared to female adult mice. We saw no difference in the expression of the myogenic regulatory factors between male and female mice, but distinct profiles were observed according to developmental stage. We show that, in contrast to adult mice, the majority of satellite cells from two week old mice are proliferating to facilitate myofibre growth; however a small proportion of these cells are quiescent and not contributing to this growth programme. Despite observed changes in satellite cell populations, there is no difference in engraftment efficiency either between satellite cells derived from adult or pre-weaned donor mice, male or female donor cells, or between male and female host muscle environments. We suggest there exist two distinct satellite cell populations: one for muscle growth and maintenance and one for muscle regeneration. PMID:22662253

High-Yield Purification, Preservation, and Serial Transplantation of Human Satellite Cells

Directory of Open Access Journals (Sweden)

Steven M. Garcia

2018-03-01

Full Text Available Summary: Investigation of human muscle regeneration requires robust methods to purify and transplant muscle stem and progenitor cells that collectively constitute the human satellite cell (HuSC pool. Existing approaches have yet to make HuSCs widely accessible for researchers, and as a result human muscle stem cell research has advanced slowly. Here, we describe a robust and predictable HuSC purification process that is effective for each human skeletal muscle tested and the development of storage protocols and transplantation models in dystrophin-deficient and wild-type recipients. Enzymatic digestion, magnetic column depletion, and 6-marker flow-cytometric purification enable separation of 104 highly enriched HuSCs per gram of muscle. Cryostorage of HuSCs preserves viability, phenotype, and transplantation potential. Development of enhanced and species-specific transplantation protocols enabled serial HuSC xenotransplantation and recovery. These protocols and models provide an accessible system for basic and translational investigation and clinical development of HuSCs. : Garcia and colleagues report methods for efficient purification of satellite cells from human skeletal muscle. They use their approaches to demonstrate stem cell functions of endogenous satellite cells and to make human satellite cells accessible for sharing among researchers. Keywords: human satellite cell purification, serial transplantation, satellite cell cryopreservation

Phage T4 endonuclease V stimulates DNA repair replication in isolated nuclei from ultraviolet-irradiated human cells, including xeroderma pigmentosum fibroblasts

International Nuclear Information System (INIS)

Smith, C.A.; Hanawalt, P.C.

1978-01-01

The repair mode of DNA replication has been demonstrated in isolated nuclei from uv-irradiated human cells. Nuclei are incubated in a mixture containing [ 3 H]thymidine triphosphate and bromodeoxyuridine triphosphate in a 1:5 ratio. The 3 H at the density of parental DNA in alkaline CsCl density gradients is then a measure of repair. In nuclei prepared from WI38 cells 30 min after irradiation, repair replication is uv-dependent and proceeds at approximately the in vivo rate for 5 min. Repair replication is reduced in irradiated nuclei or in nuclei prepared immediately after irradiation. It is Mg 2+ -dependent and stimulated by added ATP and deoxyribonucleoside triphosphates. No repair replication is observed in nuclei from xeroderma pigmentosum (complementation group A) cells. However, upon addition of coliphage T4 endonuclease V, which specifically nicks DNA containing pyrimidine dimers, repair replication is observed in nuclei from irradiated xeroderma pigmentosum cells and is stimulated in WI38 nuclei. The reaction then persists for an hour and is dependent upon added ATP and deoxyribonucleoside triphosphates. The repair label is in stretches of roughly 35 nucleotides, as it is in intact cells. Added pancreatic DNase does not promote uv-dependent repair synthesis. Our results support the view that xeroderma pigmentosum (group A) cells are defective in the incision step of the DNA excision repair pathway, and demonstrate the utility of this system for probing DNA repair mechanisms

Robust and automated three-dimensional segmentation of densely packed cell nuclei in different biological specimens with Lines-of-Sight decomposition.

Science.gov (United States)

Mathew, B; Schmitz, A; Muñoz-Descalzo, S; Ansari, N; Pampaloni, F; Stelzer, E H K; Fischer, S C

2015-06-08

Due to the large amount of data produced by advanced microscopy, automated image analysis is crucial in modern biology. Most applications require reliable cell nuclei segmentation. However, in many biological specimens cell nuclei are densely packed and appear to touch one another in the images. Therefore, a major difficulty of three-dimensional cell nuclei segmentation is the decomposition of cell nuclei that apparently touch each other. Current methods are highly adapted to a certain biological specimen or a specific microscope. They do not ensure similarly accurate segmentation performance, i.e. their robustness for different datasets is not guaranteed. Hence, these methods require elaborate adjustments to each dataset. We present an advanced three-dimensional cell nuclei segmentation algorithm that is accurate and robust. Our approach combines local adaptive pre-processing with decomposition based on Lines-of-Sight (LoS) to separate apparently touching cell nuclei into approximately convex parts. We demonstrate the superior performance of our algorithm using data from different specimens recorded with different microscopes. The three-dimensional images were recorded with confocal and light sheet-based fluorescence microscopes. The specimens are an early mouse embryo and two different cellular spheroids. We compared the segmentation accuracy of our algorithm with ground truth data for the test images and results from state-of-the-art methods. The analysis shows that our method is accurate throughout all test datasets (mean F-measure: 91%) whereas the other methods each failed for at least one dataset (F-measure≤69%). Furthermore, nuclei volume measurements are improved for LoS decomposition. The state-of-the-art methods required laborious adjustments of parameter values to achieve these results. Our LoS algorithm did not require parameter value adjustments. The accurate performance was achieved with one fixed set of parameter values. We developed a novel and

Spectrin-like proteins in plant nuclei

NARCIS (Netherlands)

Ruijter, de N.C.A.; Ketelaar, T.; Blumenthal, S.S.D.; Emons, A.M.C.; Schel, J.H.N.

2000-01-01

We analysed the presence and localization of spectrin-like proteins in nuclei of various plant tissues, using several anti-erythrocyte spectrin antibodies on isolated pea nuclei and nuclei in cells. Western blots of extracted purified pea nuclei show a cross-reactive pair of bands at 220–240 kDa,

Regulation of the muscle fiber microenvironment by activated satellite cells during hypertrophy

Science.gov (United States)

Fry, Christopher S.; Lee, Jonah D.; Jackson, Janna R.; Kirby, Tyler J.; Stasko, Shawn A.; Liu, Honglu; Dupont-Versteegden, Esther E.; McCarthy, John J.; Peterson, Charlotte A.

2014-01-01

Our aim in the current study was to determine the necessity of satellite cells for long-term muscle growth and maintenance. We utilized a transgenic Pax7-DTA mouse model, allowing for the conditional depletion of > 90% of satellite cells with tamoxifen treatment. Synergist ablation surgery, where removal of synergist muscles places functional overload on the plantaris, was used to stimulate robust hypertrophy. Following 8 wk of overload, satellite cell-depleted muscle demonstrated an accumulation of extracellular matrix (ECM) and fibroblast expansion that resulted in reduced specific force of the plantaris. Although the early growth response was normal, an attenuation of hypertrophy measured by both muscle wet weight and fiber cross-sectional area occurred in satellite cell-depleted muscle. Isolated primary myogenic progenitor cells (MPCs) negatively regulated fibroblast ECM mRNA expression in vitro, suggesting a novel role for activated satellite cells/MPCs in muscle adaptation. These results provide evidence that satellite cells regulate the muscle environment during growth.—Fry, C. S., Lee, J. D., Jackson, J. R., Kirby, T. J., Stasko, S. A., Liu, H., Dupont-Versteegden, E. E., McCarthy, J. J., Peterson, C. A. Regulation of the muscle fiber microenvironment by activated satellite cells during hypertrophy. PMID:24376025

The quasi-parallel lives of satellite cells and atrophying muscle

Directory of Open Access Journals (Sweden)

Stefano eBiressi

2015-07-01

Full Text Available Skeletal muscle atrophy or wasting accompanies various chronic illnesses and the aging process, thereby reducing muscle function. One of the most important components contributing to effective muscle repair in postnatal organisms, the satellite cells, have recently become the focus of several studies examining factors participating in the atrophic process. We critically examine here the experimental evidence linking satellite cell function with muscle loss in connection with various diseases as well as aging, and in the subsequent recovery process. Several recent reports have investigated the changes in satellite cells in terms of their differentiation and proliferative capacity in response to various atrophic stimuli. In this regard, we review the molecular changes within satellite cells that contribute to their dysfunctional status in atrophy, with the intention of shedding light on novel potential pharmacological targets to counteract the loss of muscle mass.

Loss of niche-satellite cell interactions in syndecan-3 null mice alters muscle progenitor cell homeostasis improving muscle regeneration.

Science.gov (United States)

Pisconti, Addolorata; Banks, Glen B; Babaeijandaghi, Farshad; Betta, Nicole Dalla; Rossi, Fabio M V; Chamberlain, Jeffrey S; Olwin, Bradley B

2016-01-01

The skeletal muscle stem cell niche provides an environment that maintains quiescent satellite cells, required for skeletal muscle homeostasis and regeneration. Syndecan-3, a transmembrane proteoglycan expressed in satellite cells, supports communication with the niche, providing cell interactions and signals to maintain quiescent satellite cells. Syndecan-3 ablation unexpectedly improves regeneration in repeatedly injured muscle and in dystrophic mice, accompanied by the persistence of sublaminar and interstitial, proliferating myoblasts. Additionally, muscle aging is improved in syndecan-3 null mice. Since syndecan-3 null myofiber-associated satellite cells downregulate Pax7 and migrate away from the niche more readily than wild type cells, syxndecan-3 appears to regulate satellite cell homeostasis and satellite cell homing to the niche. Manipulating syndecan-3 provides a promising target for development of therapies to enhance muscle regeneration in muscular dystrophies and in aged muscle.

Does flat epithelial atypia have rounder nuclei than columnar cell change/hyperplasia? A morphometric approach to columnar cell lesions of the breast.

Science.gov (United States)

Yamashita, Yoshiko; Ichihara, Shu; Moritani, Suzuko; Yoon, Han-Seung; Yamaguchi, Masahiro

2016-06-01

Columnar cell lesions of the breast encompass columnar cell change/hyperplasia (CCC/CCH) and flat epithelial atypia (FEA). These have attracted researchers because emerging data suggest that FEA may represent the earliest histologically detectable non-obligate precursor of breast cancer. However, it is occasionally difficult to distinguish FEA from CCC/CCH because of similar histology. Although the nuclei of FEA are frequently described as relatively round compared with those of CCC/CCH, there are few morphometric studies to support this statement. The aim of this study was to provide objective data as to the nuclear shape in columnar cell lesions. As a shape descriptor, we adopted ellipticity that is defined by the formula 2b/2a, where a is the length of the long axis of the ellipse and b is the length of the short axis. Contrary to circularity, ellipticity reflects the overall configuration of an ellipse irrespective of surface irregularity. Our image analysis included generating whole slide images, extracting glandular cell nuclei, measuring nuclear ellipticity, and superimposing graded colors based on execution of results on the captured images. A total of 7917 nuclei extracted from 22 FEA images and 5010 nuclei extracted from 13 CCC/CCH images were analyzed. There was a significant difference in nuclear roundness between FEA and CCC/CCH with mean ellipticity values of 0.723 and 0.679, respectively (p < 0.001, Welch's t test). Furthermore, FEA with malignancy had significantly rounder nuclei than FEA without malignancy (p < 0.001). Our preliminary results suggest that nuclear ellipticity is a key parameter in reproducibly classifying columnar cell lesions of the breast.

Automatic Detection of Mitosis and Nuclei from Cytogenetic Images by CellProfiler Software for Mitotic Index Estimation

International Nuclear Information System (INIS)

Gonzalez, Jorge Ernesto; Romero, Ivonne; Garcia, Omar; Radl, Analia; Di Giorgio, Marina; Barquinero, Joan Francesc

2016-01-01

Mitotic Index (MI) estimation expressed as percentage of mitosis plays an important role as quality control endpoint. To this end, MI is applied to check the lot of media and reagents to be used throughout the assay and also to check cellular viability after blood sample shipping, indicating satisfactory/unsatisfactory conditions for the progression of cell culture. The objective of this paper was to apply the CellProfiler open-source software for automatic detection of mitotic and nuclei figures from digitized images of cultured human lymphocytes for MI assessment, and to compare its performance to that performed through semi-automatic and visual detection. Lymphocytes were irradiated and cultured for mitosis detection. Sets of images from cultures were analyzed visually and findings were compared with those using CellProfiler software. The CellProfiler pipeline includes the detection of nuclei and mitosis with 80% sensitivity and more than 99% specificity. We conclude that CellProfiler is a reliable tool for counting mitosis and nuclei from cytogenetic images, saves considerable time compared to manual operation and reduces the variability derived from the scoring criteria of different scorers. The CellProfiler automated pipeline achieves good agreement with visual counting workflow, i.e. it allows fully automated mitotic and nuclei scoring in cytogenetic images yielding reliable information with minimal user intervention. (authors)

Myostatin Suppression of Akirin1 Mediates Glucocorticoid-Induced Satellite Cell Dysfunction

Science.gov (United States)

Dong, Yanjun; Pan, Jenny S.; Zhang, Liping

2013-01-01

Glucocorticoids production is increased in many pathological conditions that are associated with muscle loss, but their role in causing muscle wasting is not fully understood. We have demonstrated a new mechanism of glucocorticoid-induced muscle atrophy: Dexamethasone (Dex) suppresses satellite cell function contributing to the development of muscle atrophy. Specifically, we found that Dex decreases satellite cell proliferation and differentiation in vitro and in vivo. The mechanism involved Dex-induced upregulation of myostatin and suppression of Akirin1, a promyogenic gene. When myostatin was inhibited in Dex-treated mice, Akirin1 expression increased as did satellite cell activity, muscle regeneration and muscle growth. In addition, silencing myostatin in myoblasts or satellite cells prevented Dex from suppressing Akirin1 expression and cellular proliferation and differentiation. Finally, overexpression of Akirin1 in myoblasts increased their expression of MyoD and myogenin and improved cellular proliferation and differentiation, theses improvements were no longer suppressed by Dex. We conclude that glucocorticoids stimulate myostatin which inhibits Akirin1 expression and the reparative functions of satellite cells. These responses attribute to muscle atrophy. Thus, inhibition of myostatin or increasing Akirin1 expression could lead to therapeutic strategies for improving satellite cell activation and enhancing muscle growth in diseases associated with increased glucocorticoid production. PMID:23516508

Myostatin suppression of Akirin1 mediates glucocorticoid-induced satellite cell dysfunction.

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Yanjun Dong

Full Text Available Glucocorticoids production is increased in many pathological conditions that are associated with muscle loss, but their role in causing muscle wasting is not fully understood. We have demonstrated a new mechanism of glucocorticoid-induced muscle atrophy: Dexamethasone (Dex suppresses satellite cell function contributing to the development of muscle atrophy. Specifically, we found that Dex decreases satellite cell proliferation and differentiation in vitro and in vivo. The mechanism involved Dex-induced upregulation of myostatin and suppression of Akirin1, a promyogenic gene. When myostatin was inhibited in Dex-treated mice, Akirin1 expression increased as did satellite cell activity, muscle regeneration and muscle growth. In addition, silencing myostatin in myoblasts or satellite cells prevented Dex from suppressing Akirin1 expression and cellular proliferation and differentiation. Finally, overexpression of Akirin1 in myoblasts increased their expression of MyoD and myogenin and improved cellular proliferation and differentiation, theses improvements were no longer suppressed by Dex. We conclude that glucocorticoids stimulate myostatin which inhibits Akirin1 expression and the reparative functions of satellite cells. These responses attribute to muscle atrophy. Thus, inhibition of myostatin or increasing Akirin1 expression could lead to therapeutic strategies for improving satellite cell activation and enhancing muscle growth in diseases associated with increased glucocorticoid production.

Estimation of absorbed dose in cell nuclei due to DNA-bound /sup 3/H

Energy Technology Data Exchange (ETDEWEB)

Saito, M; Ishida, M R; Streffer, C; Molls, M

1985-04-01

The average absorbed dose due to DNA-bound /sup 3/H in a cell nucleus was estimated by a Monte Carlo simulation for a model nucleus which was assumed to be spheroidal. The volume of the cell nucleus was the major dose-determining factor for cell nuclei which have the same DNA content and the same specific activity of DNA. This result was applied to estimating the accumulated dose in the cell nuclei of organs of young mice born from mother mice which ingested /sup 3/H-thymidine with drinking water during pregnancy. The values of dose-modifying factors for the accumulated dose due to DNA-bound /sup 3/H compared to the dose due to an assumed homogenous distribution of /sup 3/H in organ were found to be between about 2 and 6 for the various organs.

A myogenic precursor cell that could contribute to regeneration in zebrafish and its similarity to the satellite cell.

Science.gov (United States)

Siegel, Ashley L; Gurevich, David B; Currie, Peter D

2013-09-01

The cellular basis for mammalian muscle regeneration has been an area of intense investigation over recent decades. The consensus is that a specialized self-renewing stem cell, termed the satellite cell, plays a major role during the process of regeneration in amniotes. How broadly this mechanism is deployed within the vertebrate phylogeny remains an open question. A lack of information on the role of cells analogous to the satellite cell in other vertebrate systems is even more unexpected given the fact that satellite cells were first designated in frogs. An intriguing aspect of this debate is that a number of amphibia and many fish species exhibit epimorphic regenerative processes in specific tissues, whereby regeneration occurs by the dedifferentiation of the damaged tissue, without deploying specialized stem cell populations analogous to satellite cells. Hence, it is feasible that a cellular process completely distinct from that deployed during mammalian muscle regeneration could operate in species capable of epimorphic regeneration. In this minireview, we examine the evidence for the broad phylogenetic distribution of satellite cells. We conclude that, in the vertebrates examined so far, epimorphosis does not appear to be deployed during muscle regeneration, and that analogous cells expressing similar marker genes to satellite cells appear to be deployed during the regenerative process. However, the functional definition of these cells as self-renewing muscle stem cells remains a final hurdle to the definition of the satellite cell as a generic vertebrate cell type. © 2013 FEBS.

Does an NSAID a Day Keep Satellite Cells at Bay?

DEFF Research Database (Denmark)

Mackey, Abigail L

2013-01-01

the activity of satellite cells, the muscle stem cell responsible for repair and maintenance of skeletal muscle. The signaling pathways that are potentially modified by NSAID exposure are also considered. Growth factors as well as inflammatory cells and connective tissue appear to be key factors......, although this clearly requires further study. The long-term implications for the muscle of the apparent inhibitory effect of NSAIDs on satellite cells in younger individuals are not clear and it is possible these may first become apparent with chronic use in athletes training at a high level...... or with advancing age. Reports of the potential for NSAIDs to alter prostaglandin and growth factor signalling provide a basis for further study of the mechanism of NSAID action on satellite cells....

Response of Turkey Muscle Satellite Cells to Thermal Challenge. II. Transcriptome Effects in Differentiating Cells

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Kent M. Reed

2017-11-01

Full Text Available Background: Exposure of poultry to extreme temperatures during the critical period of post-hatch growth can seriously affect muscle development and thus compromise subsequent meat quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells by thermal challenge during differentiation. Our goal is to better define how thermal stress alters breast muscle ultrastructure and subsequent development.Results: Skeletal muscle satellite cells previously isolated from the Pectoralis major muscle of 7-wk-old male turkeys (Meleagris gallopavo from two breeding lines: the F-line (16 wk body weight-selected and RBC2 (randombred control line were used in this study. Cultured cells were induced to differentiate at 38°C (control or thermal challenge temperatures of 33 or 43°C. After 48 h of differentiation, cells were harvested and total RNA was isolated for RNAseq analysis. Analysis of 39.9 Gb of sequence found 89% mapped to the turkey genome (UMD5.0, annotation 101 with average expression of 18,917 genes per library. In the cultured satellite cells, slow/cardiac muscle isoforms are generally present in greater abundance than fast skeletal isoforms. Statistically significant differences in gene expression were observed among treatments and between turkey lines, with a greater number of genes affected in the F-line cells following cold treatment whereas more differentially expressed (DE genes were observed in the RBC2 cells following heat treatment. Many of the most significant pathways involved signaling, consistent with ongoing cellular differentiation. Regulation of Ca2+ homeostasis appears to be significantly affected by temperature treatment, particularly cold treatment.Conclusions: Satellite cell differentiation is directly influenced by temperature at the level of gene transcription with greater effects attributed to selection for fast growth. At lower temperature, muscle-associated genes in the

Altered Satellite Cell Responsiveness and Denervation Implicated in Progression of Rotator-Cuff Injury.

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Deanna Gigliotti

Full Text Available Rotator-cuff injury (RCI is common and painful; even after surgery, joint stability and function may not recover. Relative contributions to atrophy from disuse, fibrosis, denervation, and satellite-cell responsiveness to activating stimuli are not known.Potential contributions of denervation and disrupted satellite cell responses to growth signals were examined in supraspinatus (SS and control (ipsilateral deltoid muscles biopsied from participants with RCI (N = 27. Biopsies were prepared for explant culture (to study satellite cell activity, immunostained to localize Pax7, BrdU, and Semaphorin 3A in satellite cells, sectioning to study blood vessel density, and western blotting to measure the fetal (γ subunit of acetylcholine receptor (γ-AchR. Principal component analysis (PCA for 35 parameters extracted components identified variables that contributed most to variability in the dataset. γ-AchR was higher in SS than control, indicating denervation. Satellite cells in SS had a low baseline level of activity (Pax7+ cells labelled in S-phase versus control; only satellite cells in SS showed increased proliferative activity after nitric oxide-donor treatment. Interestingly, satellite cell localization of Semaphorin 3A, a neuro-chemorepellent, was greater in SS (consistent with fiber denervation than control muscle at baseline. PCAs extracted components including fiber atrophy, satellite cell activity, fibrosis, atrogin-1, smoking status, vascular density, γAchR, and the time between symptoms and surgery. Use of deltoid as a control for SS was supported by PCA findings since "muscle" was not extracted as a variable in the first two principal components. SS muscle in RCI is therefore atrophic, denervated, and fibrotic, and has satellite cells that respond to activating stimuli.Since SS satellite cells can be activated in culture, a NO-donor drug combined with stretching could promote muscle growth and improve functional outcome after RCI. PCAs

Altered Satellite Cell Responsiveness and Denervation Implicated in Progression of Rotator-Cuff Injury.

Science.gov (United States)

Gigliotti, Deanna; Leiter, Jeff R S; MacDonald, Peter B; Peeler, Jason; Anderson, Judy E

Rotator-cuff injury (RCI) is common and painful; even after surgery, joint stability and function may not recover. Relative contributions to atrophy from disuse, fibrosis, denervation, and satellite-cell responsiveness to activating stimuli are not known. Potential contributions of denervation and disrupted satellite cell responses to growth signals were examined in supraspinatus (SS) and control (ipsilateral deltoid) muscles biopsied from participants with RCI (N = 27). Biopsies were prepared for explant culture (to study satellite cell activity), immunostained to localize Pax7, BrdU, and Semaphorin 3A in satellite cells, sectioning to study blood vessel density, and western blotting to measure the fetal (γ) subunit of acetylcholine receptor (γ-AchR). Principal component analysis (PCA) for 35 parameters extracted components identified variables that contributed most to variability in the dataset. γ-AchR was higher in SS than control, indicating denervation. Satellite cells in SS had a low baseline level of activity (Pax7+ cells labelled in S-phase) versus control; only satellite cells in SS showed increased proliferative activity after nitric oxide-donor treatment. Interestingly, satellite cell localization of Semaphorin 3A, a neuro-chemorepellent, was greater in SS (consistent with fiber denervation) than control muscle at baseline. PCAs extracted components including fiber atrophy, satellite cell activity, fibrosis, atrogin-1, smoking status, vascular density, γAchR, and the time between symptoms and surgery. Use of deltoid as a control for SS was supported by PCA findings since "muscle" was not extracted as a variable in the first two principal components. SS muscle in RCI is therefore atrophic, denervated, and fibrotic, and has satellite cells that respond to activating stimuli. Since SS satellite cells can be activated in culture, a NO-donor drug combined with stretching could promote muscle growth and improve functional outcome after RCI. PCAs suggest

Muscle satellite cells are activated after exercise to exhaustion in Thoroughbred horses.

Science.gov (United States)

Kawai, M; Aida, H; Hiraga, A; Miyata, H

2013-07-01

Although satellite cells are well known as muscle stem cells capable of adding myonuclei during muscle repair and hypertrophy, the response of satellite cells in horse muscles to a run to exhaustion is still unknown. To investigate the time course of satellite cell activation in Thoroughbred horse muscle after running to exhaustion. We hypothesised that this type of intense exercise would induce satellite cell activation in skeletal muscle similar to a resistance exercise. Nine de-trained Thoroughbred horses (6 geldings and 3 mares) aged 3-6 years were studied. Biopsy samples were taken from the gluteus medius muscle of the horses before and 1 min, 3 h, 1 day, 3 days, 1 week and 2 weeks after a treadmill run to exhaustion. The numbers of satellite cells for each fibre type were determined by using immunofluorescence staining. Total RNA was extracted from these samples, and the expressions of interleukin (IL)-6, paired box transcriptional factor (Pax) 7, myogenic differentiation 1 (MyoD), myogenin, proliferating cell nuclear antigen (PCNA), insulin-like growth factor (IGF)-I and hepatocyte growth factor (HGF) mRNA were analysed using real-time reverse transcription-PCR. The numbers of satellite cells were significantly increased in type I and IIa fibres at 1 week and in type IIa/x fibre at 2 weeks post exercise. The expression of IL-6 mRNA increased significantly by 3 h post exercise. The expression of PCNA mRNA also increased by 1 day after running, indicating that running can initiate satellite cell proliferation. The expression of Pax7, MyoD, myogenin, IGF-I and HGF mRNA peaked at 1 week post exercise. Satellite cell activation and proliferation could be enhanced after a run to exhaustion without detectable injury as assessed by the histochemical analysis. Understanding the response of satellite cell activation to running exercise provides fundamental information about the skeletal muscle adaptation in Thoroughbred horses. © 2012 EVJ Ltd.

Change in ATP-ase activity and transport of rna of liver cell nuclei of pregnant rats and embryos following irradiation

International Nuclear Information System (INIS)

Shamsutdinova, G.T.; Mirkhamidova, P.; Ibragimkhodzhaeva, M.P.; Mirakhmedov, A.K.

1990-01-01

The effect of radiation on ATP-ase activity in rat liver nuclei and RNA transport of isolated liver nuclei in vitro is studied. It is shown that irradiation changes RNA transport from isolated liver cell nuclei of maternal organism and embryos. Irradiation during prefetus and fetus periods changes ATP-ase activity of embryon and maternal organism nuclei

Three dimensional analysis of histone methylation patterns in normal and tumor cell nuclei

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M Cremer

2009-06-01

Full Text Available Histone modifications represent an important epigenetic mechanism for the organization of higher order chromatin structure and gene regulation. Methylation of position-specific lysine residues in the histone H3 and H4 amino termini has been linked with the formation of constitutive and facultative heterochromatin as well as with specifically repressed single gene loci. Using an antibody, directed against dimethylated lysine 9 of histone H3 and several other lysine methylation sites, we visualized the nuclear distribution pattern of chromatin flagged by these methylated lysines in 3D preserved nuclei of normal and malignant cell types. Optical confocal serial sections were used for a quantitative evaluation. We demonstrate distinct differences of these histone methylation patterns among nuclei of different cell types after exit of the cell cycle. Changes in the pattern formation were also observed during the cell cycle. Our data suggest an important role of methylated histones in the reestablishment of higher order chromatin arrangements during telophase/early G1. Cell type specific histone methylation patterns are possibly causally involved in the formation of cell type specific heterochromatin compartments, composed of (pericentromeric regions and chromosomal subregions from neighboring chromosome territories, which contain silent genes.

Automatic Detection of Mitosis and Nuclei From Cytogenetic Images by CellProfiler Software for Mitotic Index Estimation.

Science.gov (United States)

González, Jorge Ernesto; Radl, Analía; Romero, Ivonne; Barquinero, Joan Francesc; García, Omar; Di Giorgio, Marina

2016-12-01

Mitotic Index (MI) estimation expressed as percentage of mitosis plays an important role as quality control endpoint. To this end, MI is applied to check the lot of media and reagents to be used throughout the assay and also to check cellular viability after blood sample shipping, indicating satisfactory/unsatisfactory conditions for the progression of cell culture. The objective of this paper was to apply the CellProfiler open-source software for automatic detection of mitotic and nuclei figures from digitized images of cultured human lymphocytes for MI assessment, and to compare its performance to that performed through semi-automatic and visual detection. Lymphocytes were irradiated and cultured for mitosis detection. Sets of images from cultures were analyzed visually and findings were compared with those using CellProfiler software. The CellProfiler pipeline includes the detection of nuclei and mitosis with 80% sensitivity and more than 99% specificity. We conclude that CellProfiler is a reliable tool for counting mitosis and nuclei from cytogenetic images, saves considerable time compared to manual operation and reduces the variability derived from the scoring criteria of different scorers. The CellProfiler automated pipeline achieves good agreement with visual counting workflow, i.e. it allows fully automated mitotic and nuclei scoring in cytogenetic images yielding reliable information with minimal user intervention. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

Energy Technology Data Exchange (ETDEWEB)

Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Ohashi, Kazuya; Wada, Eiji; Yuasa, Yuki; Shiozuka, Masataka; Nonomura, Yoshiaki; Matsuda, Ryoichi

2014-08-01

Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and its

Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

International Nuclear Information System (INIS)

Nagata, Yosuke; Ohashi, Kazuya; Wada, Eiji; Yuasa, Yuki; Shiozuka, Masataka; Nonomura, Yoshiaki; Matsuda, Ryoichi

2014-01-01

Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and its

The muscle stem cell niche : regulation of satellite cells during regeneration

NARCIS (Netherlands)

Boonen, K.J.M.; Post, M.J.

2008-01-01

Satellite cells are considered to be adult skeletal muscle stem cells. Their ability to regenerate large muscle defects is highly dependent on their specific niche. When these cells are cultured in vitro, the loss of this niche leads to a loss of proliferative capacity and defective regeneration

Myogenic potential of canine craniofacial satellite cells

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Rita Maria Laura La Rovere

2014-05-01

Full Text Available The skeletal fibres have different embryological origin; the extraocular and jaw-closer muscles develop from prechordal mesoderm while the limb and trunk muscles from somites. These different origins characterise also the adult muscle stem cells, known as satellite cells (SCs and responsible for the fibre growth and regeneration. The physiological properties of presomitic SCs and their epigenetics are poorly studied despite their peculiar characteristics to preserve muscle integrity during chronic muscle degeneration. Here we isolated SCs from canine somitic (SDM: vastus lateralis, rectus abdominus, gluteus superficialis, biceps femoris, psoas and presomitic (PSDM: lateral rectus, temporalis and retractor bulbi muscles as myogenic progenitor cells from young and old animals. In addition, SDM and PSDM satellite cells were obtained also from Golden retrievers affected by muscular dystrophy (GRMD. We characterised the lifespan, the myogenic potential and functions and oxidative stress of both somitic and presomitic SCs with the aim to reveal differences with ageing and between healthy and dystrophic animals. The different proliferation rate was consistent with higher telomerase activity in PSDM-SCs compared to SDM-SCs, although restricted at early passages. SDM-SCs express early (Pax7, MyoD and late (MyHC, Myogenin myogenic markers differently from PSDM-SCs resulting in a more efficient and faster cell differentiation. Taken together our results showed that PSDM-SCs elicit a stronger stem cell phenotype compared to SDM ones. Finally, myomiR expression profile reveals a unique epigenetic signature in GRMD satellite cells and miR-206, highly expressed in dystrophic SCs, seems to play a critical role in muscle degeneration. Thus, miR-206 could represent a potential target for novel therapeutic approaches.

On the occurrence of nuclei in mature sieve elements.

Science.gov (United States)

Event, R F; Davis, J D; Tucker, C M; Alfieri, F J

1970-12-01

The secondary phloem of 3 species of the Taxodiaceae and 13 species of woody dicotyledons was examined for the occurrence of nuclei in mature sieve elements. Nuclei were found in all mature sieve cells of Metasequoia glyptostroboides, Sequoia sempervirens and Taxodium distichum, and in some mature sieve-tube members in 12 of the 13 species of woody dicotyledons. Except for nuclei of sieve cells undergoing cessation of function, the nuclei in mature sieve cells of M. glyptostroboides, S. sempervirens and T. distichum were normal in appearance. The occurrence and morphology of nuclei in mature sieve-tube members of the woody dicotyledons were quite variable. Only 3 species, Robinia pseudoacacia, Ulmus americana and Vitis riparia, contained some mature sieve elements with apparently normal nuclei.

Isolation of Nuclei and Nucleoli.

Science.gov (United States)

Pendle, Alison F; Shaw, Peter J

2017-01-01

Here we describe methods for producing nuclei from Arabidopsis suspension cultures or root tips of Arabidopsis, wheat, or pea. These methods could be adapted for other species and cell types. The resulting nuclei can be further purified for use in biochemical or proteomic studies, or can be used for microscopy. We also describe how the nuclei can be used to obtain a preparation of nucleoli.

TRAF6 regulates satellite stem cell self-renewal and function during regenerative myogenesis

Science.gov (United States)

Hindi, Sajedah M.; Kumar, Ashok

2015-01-01

Satellite cells are a stem cell population within adult muscle and are responsible for myofiber regeneration upon injury. Satellite cell dysfunction has been shown to underlie the loss of skeletal muscle mass in many acquired and genetic muscle disorders. The transcription factor paired box-protein-7 (PAX7) is indispensable for supplementing the reservoir of satellite cells and driving regeneration in normal and diseased muscle. TNF receptor–associated factor 6 (TRAF6) is an adaptor protein and an E3 ubiquitin ligase that mediates the activation of multiple cell signaling pathways in a context-dependent manner. Here, we demonstrated that TRAF6-mediated signaling is critical for homeostasis of satellite cells and their function during regenerative myogenesis. Selective deletion of Traf6 in satellite cells of adult mice led to profound muscle regeneration defects and dramatically reduced levels of PAX7 and late myogenesis markers. TRAF6 was required for the activation of MAPKs ERK1/2 and JNK1/2, which in turn activated the transcription factor c-JUN, which binds the Pax7 promoter and augments Pax7 expression. Moreover, TRAF6/c-JUN signaling repressed the levels of the microRNAs miR-1 and miR-206, which promote differentiation, to maintain PAX7 levels in satellite cells. We also determined that satellite cell–specific deletion of Traf6 exaggerates the dystrophic phenotype in the mdx (a mouse model of Duchenne muscular dystrophy) mouse by blunting the regeneration of injured myofibers. Collectively, our study reveals an essential role for TRAF6 in satellite stem cell function. PMID:26619121

Response of turkey muscle satellite cells to thermal challenge. I. transcriptome effects in proliferating cells.

Science.gov (United States)

Reed, Kent M; Mendoza, Kristelle M; Abrahante, Juan E; Barnes, Natalie E; Velleman, Sandra G; Strasburg, Gale M

2017-05-06

Climate change poses a multi-dimensional threat to food and agricultural systems as a result of increased risk to animal growth, development, health, and food product quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells cultured under cold or hot thermal challenge to better define molecular mechanisms by which thermal stress alters breast muscle ultrastructure. Satellite cells isolated from the pectoralis major muscle of 7-weeks-old male turkeys from two breeding lines (16 weeks body weight-selected and it's randombred control) were proliferated in culture at 33 °C, 38 °C or 43 °C for 72 h. Total RNA was isolated and 12 libraries subjected to RNAseq analysis. Statistically significant differences in gene expression were observed among treatments and between turkey lines with a greater number of genes altered by cold treatment than by hot and fewer differences observed between lines than between temperatures. Pathway analysis found that cold treatment resulted in an overrepresentation of genes involved in cell signaling/signal transduction and cell communication/cell signaling as compared to control (38 °C). Heat-treated muscle satellite cells showed greater tendency towards expression of genes related to muscle system development and differentiation. This study demonstrates significant transcriptome effects on turkey skeletal muscle satellite cells exposed to thermal challenge. Additional effects on gene expression could be attributed to genetic selection for 16 weeks body weight (muscle mass). New targets are identified for further research on the differential control of satellite cell proliferation in poultry.

[A morphometric analysis of the nuclei and nucleoli in tumor cells in lymphogranulomatosis, diffuse large B-cell lymphoma and anaplastic large cell lymphoma].

Science.gov (United States)

Gorgidze, L A; Vorob'ev, I A

2009-01-01

To make a comparative morphometric analysis of the nuclei and nucleoli of tumor cells in lymphogranulomatosis (LGM), diffuse large B-cell lymphoma (DLBCL) and anaplastic large cell lymphoma (ALCL) for differential diagnosis of these lymphomas. Biopsy material (lymph node biopsies) was frozen in hexane, fixed and stained, then microscopic pictures were made. Mean area of tumor cell nuclei in LGM was 97.25 +/- 68.77 mcm2, in DLBCL and ALCL--55.89 +/- 20.13 mcm2 and 70.31 +/- 34.64 mcm2, respectively. The area differences were significant (p nucleoli of the former are larger than those of the latter. Mean area of the nucleoli in DLBCL was 3.05 +/- 1.58, in ALCL--5.53 +/- 4.94 mcm2. The differences are significant (p Nucleoli in Hodgkin 's cells are significantly larger than those in the tumor cells in ALCL and DLBCL and the nucleoli with the area more than 12 mcm2 can be used in differential diagnosis between LGM and DLBCL but not between LGM and ALCL.

Skeletal Muscle Satellite Cells Are Committed to Myogenesis and Do Not Spontaneously Adopt Nonmyogenic Fates

Science.gov (United States)

Starkey, Jessica D.; Yamamoto, Masakazu; Yamamoto, Shoko; Goldhamer, David J.

2011-01-01

The developmental potential of skeletal muscle stem cells (satellite cells) remains controversial. The authors investigated satellite cell developmental potential in single fiber and clonal cultures derived from MyoDiCre/+;R26REYFP/+ muscle, in which essentially all satellite cells are permanently labeled. Approximately 60% of the clones derived from cells that co-purified with muscle fibers spontaneously underwent adipogenic differentiation. These adipocytes stained with Oil-Red-O and expressed the terminal differentiation markers, adipsin and fatty acid binding protein 4, but did not express EYFP and were therefore not of satellite cell origin. Satellite cells mutant for either MyoD or Myf-5 also maintained myogenic programming in culture and did not adopt an adipogenic fate. Incorporation of additional wash steps prior to muscle fiber plating virtually eliminated the non-myogenic cells but did not reduce the number of adherent Pax7+ satellite cells. More than half of the adipocytes observed in cultures from Tie2-Cre mice were recombined, further demonstrating a non-satellite cell origin. Under adipogenesis-inducing conditions, satellite cells accumulated cytoplasmic lipid but maintained myogenic protein expression and did not fully execute the adipogenic differentiation program, distinguishing them from adipocytes observed in muscle fiber cultures. The authors conclude that skeletal muscle satellite cells are committed to myogenesis and do not spontaneously adopt an adipogenic fate. PMID:21339173

A global downregulation of microRNAs occurs in human quiescent satellite cells during myogenesis

NARCIS (Netherlands)

Koning, Merel; Werker, Paul M N; van Luyn, Marja J A; Krenning, Guido; Harmsen, Martin C

2012-01-01

During myogenesis, human satellite cells differentiate and form multinucleated myotubes, while a fraction of the human satellite cells enter quiescence. These quiescent satellite cells are able to activate, proliferate and contribute to muscle regeneration. Post-transcriptional regulation of

Lsd1 regulates skeletal muscle regeneration and directs the fate of satellite cells.

Science.gov (United States)

Tosic, Milica; Allen, Anita; Willmann, Dominica; Lepper, Christoph; Kim, Johnny; Duteil, Delphine; Schüle, Roland

2018-01-25

Satellite cells are muscle stem cells required for muscle regeneration upon damage. Of note, satellite cells are bipotent and have the capacity to differentiate not only into skeletal myocytes, but also into brown adipocytes. Epigenetic mechanisms regulating fate decision and differentiation of satellite cells during muscle regeneration are not yet fully understood. Here, we show that elevated levels of lysine-specific demethylase 1 (Kdm1a, also known as Lsd1) have a beneficial effect on muscle regeneration and recovery after injury, since Lsd1 directly regulates key myogenic transcription factor genes. Importantly, selective Lsd1 ablation or inhibition in Pax7-positive satellite cells, not only delays muscle regeneration, but changes cell fate towards brown adipocytes. Lsd1 prevents brown adipocyte differentiation of satellite cells by repressing expression of the novel pro-adipogenic transcription factor Glis1. Together, downregulation of Glis1 and upregulation of the muscle-specific transcription program ensure physiological muscle regeneration.

EFFECTS OF VOLUNTARY WHEEL RUNNING ON SATELLITE CELLS IN THE RAT PLANTARIS MUSCLE

Directory of Open Access Journals (Sweden)

Atsushi Kojima

2009-03-01

Full Text Available This study investigated the effects of voluntary wheel running on satellite cells in the rat plantaris muscle. Seventeen 5-week-old male Wistar rats were assigned to a control (n = 5 or training (n = 12 group. Each rat in the training group ran voluntarily in a running-wheel cage for 8 weeks. After the training period, the animals were anesthetized, and the plantaris muscles were removed, weighed, and analyzed immunohistochemically and biochemically. Although there were no significant differences in muscle weight or fiber area between the groups, the numbers of satellite cells and myonuclei per muscle fiber, percentage of satellite cells, and citrate synthase activity were significantly higher in the training group compared with the control group (p < 0.05. The percentage of satellite cells was also positively correlated with distance run in the training group (r = 0.61, p < 0.05. Voluntary running can induce an increase in the number of satellite cells without changing the mean fiber area in the rat plantaris muscle; this increase in satellite cell content is a function of distance run

Measurement of charge and energy spectra of heavy nuclei aboard Cosmos-936 artificial Earth satellite

International Nuclear Information System (INIS)

Dashin, S.A.; Marennyy, A.M.; Gertsen, G.P.

1982-07-01

Charge and energy spectra of heavy charged particles were measured. Measurements were performed by a package of dielectric track detectors mounted behind the shield of 60-80 kg m to the minus second power thick. The charge of nuclei was determined from the complete track length. A group of 1915 tracks of nuclei with Z 6 in the energy range 100-450 MeV/nuclon were identified. The differential charge spectrum of nuclei with 6 Z 28 and the energy spectrum of nuclei of the iron group were built

Effects of voluntary wheel running on satellite cells in the rat plantaris muscle.

Science.gov (United States)

Kurosaka, Mitsutoshi; Naito, Hisashi; Ogura, Yuji; Kojima, Atsushi; Goto, Katsumasa; Katamoto, Shizuo

2009-01-01

This study investigated the effects of voluntary wheel running on satellite cells in the rat plantaris muscle. Seventeen 5-week-old male Wistar rats were assigned to a control (n = 5) or training (n = 12) group. Each rat in the training group ran voluntarily in a running-wheel cage for 8 weeks. After the training period, the animals were anesthetized, and the plantaris muscles were removed, weighed, and analyzed immunohistochemically and biochemically. Although there were no significant differences in muscle weight or fiber area between the groups, the numbers of satellite cells and myonuclei per muscle fiber, percentage of satellite cells, and citrate synthase activity were significantly higher in the training group compared with the control group (p run in the training group (r = 0.61, p running can induce an increase in the number of satellite cells without changing the mean fiber area in the rat plantaris muscle; this increase in satellite cell content is a function of distance run. Key pointsThere is no study about the effect of voluntary running on satellite cells in the rat plantaris muscle.Voluntary running training causes an increase of citrate synthase activity in the rat plantaris muscle but does not affect muscle weight and mean fiber area in the rat plantaris muscle.Voluntary running can induce an increase in the number of satellite cells without hypertrophy of the rat plantaris muscle.

Reduced satellite cell population may lead to contractures in children with cerebral palsy.

Science.gov (United States)

Smith, Lucas R; Chambers, Henry G; Lieber, Richard L

2013-03-01

Satellite cells are the stem cells residing in muscle responsible for skeletal muscle growth and repair. Skeletal muscle in cerebral palsy (CP) has impaired longitudinal growth that results in muscle contractures. We hypothesized that the satellite cell population would be reduced in contractured muscle. We compared the satellite cell populations in hamstring muscles from participants with CP contracture (n=8; six males, two females; age range 6-15y; Gross Motor Function Classification System [GMFCS] levels II-V; 4 with hemiplegia, 4 with diplegia) and from typically developing participants (n=8; six males, two females, age range 15-18y). Muscle biopsies were extracted from the gracilis and semitendinosus muscles and mononuclear cells were isolated. Cell surface markers were stained with fluorescently conjugated antibodies to label satellite cells (neural cell adhesion molecule) and inflammatory and endothelial cells (CD34 and CD4 respectively). Cells were analyzed using flow cytometry to determine cell populations. After gating for intact cells a mean of 12.8% (SD 2.8%) were determined to be satellite cells in typically developing children, but only 5.3% (SD 2.3%; p0.05) suggesting the isolation procedure was valid. A reduced satellite cell population may account for the decreased longitudinal growth of muscles in CP that develop into fixed contractures or the decreased ability to strengthen muscle in CP. This suggests a unique musculoskeletal disease mechanism and provides a potential therapeutic target for debilitating muscle contractures. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

Cell nuclei attributed relational graphs for efficient representation and classification of gastric cancer in digital histopathology

Science.gov (United States)

Sharma, Harshita; Zerbe, Norman; Heim, Daniel; Wienert, Stephan; Lohmann, Sebastian; Hellwich, Olaf; Hufnagl, Peter

2016-03-01

This paper describes a novel graph-based method for efficient representation and subsequent classification in histological whole slide images of gastric cancer. Her2/neu immunohistochemically stained and haematoxylin and eosin stained histological sections of gastric carcinoma are digitized. Immunohistochemical staining is used in practice by pathologists to determine extent of malignancy, however, it is laborious to visually discriminate the corresponding malignancy levels in the more commonly used haematoxylin and eosin stain, and this study attempts to solve this problem using a computer-based method. Cell nuclei are first isolated at high magnification using an automatic cell nuclei segmentation strategy, followed by construction of cell nuclei attributed relational graphs of the tissue regions. These graphs represent tissue architecture comprehensively, as they contain information about cell nuclei morphology as vertex attributes, along with knowledge of neighborhood in the form of edge linking and edge attributes. Global graph characteristics are derived and ensemble learning is used to discriminate between three types of malignancy levels, namely, non-tumor, Her2/neu positive tumor and Her2/neu negative tumor. Performance is compared with state of the art methods including four texture feature groups (Haralick, Gabor, Local Binary Patterns and Varma Zisserman features), color and intensity features, and Voronoi diagram and Delaunay triangulation. Texture, color and intensity information is also combined with graph-based knowledge, followed by correlation analysis. Quantitative assessment is performed using two cross validation strategies. On investigating the experimental results, it can be concluded that the proposed method provides a promising way for computer-based analysis of histopathological images of gastric cancer.

Satellite NMR in Cu doped with transition impurities

International Nuclear Information System (INIS)

Slichter, C.P.

1979-01-01

Measurements were made of the conduction electron spin magnetization density, M/sub sigma/(R vector) near iron group atoms (Sc through Ni) in Cu. M/sub sigma/(R vector) produces an additional effective local field which shifts the NMR frequency of nearby shells of Cu nuclei relative to Cu nuclei far from all impurities. Resonances of nearby shells appear as weak satellites to the strong resonance of distant Cu nuclei (the main line). M/sub sigma/(R vector) at a given site is proportional through know constants to the splitting of the satellite from the main line. The shell was identified giving rise to the satellite in many cases by use of single crystals. A good approximation M/sub sigma/(R vector) is proportional to the spin susceptibility chi/sub s/ of the impurity. For CuCr we find a large temperature independent chi/sub s/, in contrast to CuMn and CuFe. The results lead to a picture of the electronic structure of Cr, Mn, and Fe along the lines of Schrieffer and Hirst as ions with integral numbers of d-electrons, possessing crystal field and spin-orbit couplings

Roles of Notch1 Signaling in Regulating Satellite Cell Fates Choices and Postnatal Skeletal Myogenesis.

Science.gov (United States)

Shan, Tizhong; Xu, Ziye; Wu, Weiche; Liu, Jiaqi; Wang, Yizhen

2017-11-01

Adult skeletal muscle stem cells, also called satellite cells, are indispensable for the growth, maintenance, and regeneration of the postnatal skeletal muscle. Satellite cells, predominantly quiescent in mature resting muscles, are activated after skeletal muscle injury or degeneration. Notch1 signaling is an evolutionarily conserved pathway that plays crucial roles in satellite cells homeostasis and postnatal skeletal myogenesis and regeneration. Activation of Notch1 signaling promotes the muscle satellite cells quiescence and proliferation, but inhibits differentiation of muscle satellite cells. Notably, the new roles of Notch1 signaling during late-stage of skeletal myogenesis including in post-differentiation myocytes and post-fusion myotubes have been recently reported. Here, we mainly review and discuss the regulatory roles of Notch1 in regulating satellite cell fates choices and skeletal myogenesis. J. Cell. Physiol. 232: 2964-2967, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Computer vision approach to morphometric feature analysis of basal cell nuclei for evaluating malignant potentiality of oral submucous fibrosis.

Science.gov (United States)

Muthu Rama Krishnan, M; Pal, Mousumi; Paul, Ranjan Rashmi; Chakraborty, Chandan; Chatterjee, Jyotirmoy; Ray, Ajoy K

2012-06-01

This research work presents a quantitative approach for analysis of histomorphometric features of the basal cell nuclei in respect to their size, shape and intensity of staining, from surface epithelium of Oral Submucous Fibrosis showing dysplasia (OSFD) to that of the Normal Oral Mucosa (NOM). For all biological activity, the basal cells of the surface epithelium form the proliferative compartment and therefore their morphometric changes will spell the intricate biological behavior pertaining to normal cellular functions as well as in premalignant and malignant status. In view of this, the changes in shape, size and intensity of staining of the nuclei in the basal cell layer of the NOM and OSFD have been studied. Geometric, Zernike moments and Fourier descriptor (FD) based as well as intensity based features are extracted for histomorphometric pattern analysis of the nuclei. All these features are statistically analyzed along with 3D visualization in order to discriminate the groups. Results showed increase in the dimensions (area and perimeter), shape parameters and decreasing mean nuclei intensity of the nuclei in OSFD in respect to NOM. Further, the selected features are fed to the Bayesian classifier to discriminate normal and OSFD. The morphometric and intensity features provide a good sensitivity of 100%, specificity of 98.53% and positive predicative accuracy of 97.35%. This comparative quantitative characterization of basal cell nuclei will be of immense help for oral onco-pathologists, researchers and clinicians to assess the biological behavior of OSFD, specially relating to their premalignant and malignant potentiality. As a future direction more extensive study involving more number of disease subjects is observed.

mTOR is necessary for proper satellite cell activity and skeletal muscle regeneration

Energy Technology Data Exchange (ETDEWEB)

Zhang, Pengpeng [Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); Liang, Xinrong; Shan, Tizhong [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); Jiang, Qinyang [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); College of Animal Science and Technology, Guangxi University, Nanning 530004 (China); Deng, Changyan [Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Zheng, Rong, E-mail: zhengrong@mail.hzau.edu.cn [Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Kuang, Shihuan, E-mail: skuang@purdue.edu [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States)

2015-07-17

The serine/threonine kinase mammalian target of rapamycin (mTOR) is a key regulator of protein synthesis, cell proliferation and energy metabolism. As constitutive deletion of Mtor gene results in embryonic lethality, the function of mTOR in muscle stem cells (satellite cells) and skeletal muscle regeneration remains to be determined. In this study, we established a satellite cell specific Mtor conditional knockout (cKO) mouse model by crossing Pax7{sup CreER} and Mtor{sup flox/flox} mice. Skeletal muscle regeneration after injury was severely compromised in the absence of Mtor, indicated by increased number of necrotic myofibers infiltrated by Evans blue dye, and reduced number and size of regenerated myofibers in the Mtor cKO mice compared to wild type (WT) littermates. To dissect the cellular mechanism, we analyzed satellite cell-derived primary myoblasts grown on single myofibers or adhered to culture plates. The Mtor cKO myoblasts exhibited defective proliferation and differentiation kinetics when compared to myoblasts derived from WT littermates. At the mRNA and protein levels, the Mtor cKO myoblasts expressed lower levels of key myogenic determinant genes Pax7, Myf5, Myod, Myog than did the WT myoblasts. These results suggest that mTOR is essential for satellite cell function and skeletal muscle regeneration through controlling the expression of myogenic genes. - Highlights: • Pax7{sup CreER} was used to delete Mtor gene in satellite cells. • Satellite cell specific deletion of Mtor impairs muscle regeneration. • mTOR is necessary for satellite cell proliferation and differentiation. • Deletion of Mtor leads to reduced expression of key myogenic genes.

mTOR is necessary for proper satellite cell activity and skeletal muscle regeneration

International Nuclear Information System (INIS)

Zhang, Pengpeng; Liang, Xinrong; Shan, Tizhong; Jiang, Qinyang; Deng, Changyan; Zheng, Rong; Kuang, Shihuan

2015-01-01

The serine/threonine kinase mammalian target of rapamycin (mTOR) is a key regulator of protein synthesis, cell proliferation and energy metabolism. As constitutive deletion of Mtor gene results in embryonic lethality, the function of mTOR in muscle stem cells (satellite cells) and skeletal muscle regeneration remains to be determined. In this study, we established a satellite cell specific Mtor conditional knockout (cKO) mouse model by crossing Pax7 CreER and Mtor flox/flox mice. Skeletal muscle regeneration after injury was severely compromised in the absence of Mtor, indicated by increased number of necrotic myofibers infiltrated by Evans blue dye, and reduced number and size of regenerated myofibers in the Mtor cKO mice compared to wild type (WT) littermates. To dissect the cellular mechanism, we analyzed satellite cell-derived primary myoblasts grown on single myofibers or adhered to culture plates. The Mtor cKO myoblasts exhibited defective proliferation and differentiation kinetics when compared to myoblasts derived from WT littermates. At the mRNA and protein levels, the Mtor cKO myoblasts expressed lower levels of key myogenic determinant genes Pax7, Myf5, Myod, Myog than did the WT myoblasts. These results suggest that mTOR is essential for satellite cell function and skeletal muscle regeneration through controlling the expression of myogenic genes. - Highlights: • Pax7 CreER was used to delete Mtor gene in satellite cells. • Satellite cell specific deletion of Mtor impairs muscle regeneration. • mTOR is necessary for satellite cell proliferation and differentiation. • Deletion of Mtor leads to reduced expression of key myogenic genes

Effect of TCEA3 on the differentiation of bovine skeletal muscle satellite cells

International Nuclear Information System (INIS)

Zhu, Yue; Tong, Hui-Li; Li, Shu-Feng; Yan, Yun-Qin

2017-01-01

Bovine muscle-derived satellite cells (MDSCs) are important for animal growth. In this study, the effect of transcription elongation factor A3 (TCEA3) on bovine MDSC differentiation was investigated. Western blotting, immunofluorescence assays, and cytoplasmic and nuclear protein isolation and purification techniques were used to determine the expression pattern and protein localization of TCEA3 in bovine MDSCs during in vitro differentiation. TCEA3 expression was upregulated using the CRISPR/Cas9 technique to study its effects on MDSC differentiation in vitro. TCEA3 expression gradually increased during the in vitro differentiation of bovine MDSCs and peaked on the 5th day of differentiation. TCEA3 was mainly localized in the cytoplasm of bovine MDSCs, and its expression was not detected in the nucleus. The level of TCEA3 was relatively higher in myotubes at a higher degree of differentiation than during early differentiation. After transfection with a TCEA3-activating plasmid vector (TCEA3 overexpression) for 24 h, the myotube fusion rate, number of myotubes, and expression levels of the muscle differentiation-related loci myogenin (MYOG) and myosin heavy chain 3 (MYH3) increased significantly during the in vitro differentiation of bovine MDSCs. After transfection with a TCEA3-inhibiting plasmid vector for 24 h, the myotube fusion rate, number of myotubes, and expression levels of MYOG and MYH3 decreased significantly. Our results indicated, for the first time, that TCEA3 promotes the differentiation of bovine MDSCs and have implications for meat production and animal rearing. - Highlights: • Muscle-derived satellite cell differentiation is promoted by TCEA3. • TCEA3 protein was localized in the cytoplasm, but not nuclei of bovine MDSCs. • TCEA3 levels increased as myotube differentiation increased. • TCEA3 affected myotube fusion, myotube counts, and MYOG and MYH3 levels.

Enhanced satellite cell proliferation with resistance training in elderly men and women

DEFF Research Database (Denmark)

Mackey, Abigail; Esmarck, B; Kadi, F

2007-01-01

In addition to the well-documented loss of muscle mass and strength associated with aging, there is evidence for the attenuating effects of aging on the number of satellite cells in human skeletal muscle. The aim of this study was to investigate the response of satellite cells in elderly men...... and women to 12 weeks of resistance training. Biopsies were collected from the m. vastus lateralis of 13 healthy elderly men and 16 healthy elderly women (mean age 76+/-SD 3 years) before and after the training period. Satellite cells were visualized by immunohistochemical staining of muscle cross.......15+/-0.06; mean+/-SD) and females (from 0.11+/-0.04 to 0.13+/-0.05). These results suggest that 12 weeks of resistance training is effective in enhancing the satellite cell pool in skeletal muscle in the elderly....

Determining the number of clusters for nuclei segmentation in breast cancer image

Science.gov (United States)

Fatichah, Chastine; Navastara, Dini Adni; Suciati, Nanik; Nuraini, Lubna

2017-02-01

Clustering is commonly technique for image segmentation, however determining an appropriate number of clusters is still challenging. Due to nuclei variation of size and shape in breast cancer image, an automatic determining number of clusters for segmenting the nuclei breast cancer is proposed. The phase of nuclei segmentation in breast cancer image are nuclei detection, touched nuclei detection, and touched nuclei separation. We use the Gram-Schmidt for nuclei cell detection, the geometry feature for touched nuclei detection, and combining of watershed and spatial k-Means clustering for separating the touched nuclei in breast cancer image. The spatial k-Means clustering is employed for separating the touched nuclei, however automatically determine the number of clusters is difficult due to the variation of size and shape of single cell breast cancer. To overcome this problem, first we apply watershed algorithm to separate the touched nuclei and then we calculate the distance among centroids in order to solve the over-segmentation. We merge two centroids that have the distance below threshold. And the new of number centroid as input to segment the nuclei cell using spatial k- Means algorithm. Experiment show that, the proposed scheme can improve the accuracy of nuclei cell counting.

Geomagnetically trapped carbon, nitrogen, and oxygen nuclei.

Science.gov (United States)

Mogro-Campero, A.

1972-01-01

Results of measurements carried out with the University of Chicago nuclear composition telescope on the Ogo 5 satellite, establishing the presence of 13- to 33-MeV/nucleon geomagnetically trapped C and O nuclei, with some evidence for N nuclei. These trapped nuclei were found at L less than or equal to 5 and near the geomagnetic equator. The data cover the period from Mar. 3, 1968, to Dec. 31, 1969. The distribution of CNO flux as a function of L is given. No change in the intensity of the average trapped CNO flux was detected by comparing data for 1968 and 1969. The results reported set a new value for the observed high energy limit of trapping as described by the critical adiabaticity parameter. The penetration of solar flare CNO up to L = 4 was observed twice in 1968, in disagreement with Stormer theory predictions. The effects of these results on some models for the origin of the trapped radiation are discussed.

Reduced satellite cell numbers and myogenic capacity in aging can be alleviated by endurance exercise.

Directory of Open Access Journals (Sweden)

Gabi Shefer

2010-10-01

Full Text Available Muscle regeneration depends on satellite cells, myogenic stem cells that reside on the myofiber surface. Reduced numbers and/or decreased myogenic aptitude of these cells may impede proper maintenance and contribute to the age-associated decline in muscle mass and repair capacity. Endurance exercise was shown to improve muscle performance; however, the direct impact on satellite cells in aging was not yet thoroughly determined. Here, we focused on characterizing the effect of moderate-intensity endurance exercise on satellite cell, as possible means to attenuate adverse effects of aging. Young and old rats of both genders underwent 13 weeks of treadmill-running or remained sedentary.Gastrocnemius muscles were assessed for the effect of age, gender and exercise on satellite-cell numbers and myogenic capacity. Satellite cells were identified in freshly isolated myofibers based on Pax7 immunostaining (i.e., ex-vivo. The capacity of individual myofiber-associated cells to produce myogenic progeny was determined in clonal assays (in-vitro. We show an age-associated decrease in satellite-cell numbers and in the percent of myogenic clones in old sedentary rats. Upon exercise, there was an increase in myofibers that contain higher numbers of satellite cells in both young and old rats, and an increase in the percent of myogenic clones derived from old rats. Changes at the satellite cell level in old rats were accompanied with positive effects on the lean-to-fat Gast muscle composition and on spontaneous locomotion levels. The significance of these data is that they suggest that the endurance exercise-mediated boost in both satellite numbers and myogenic properties may improve myofiber maintenance in aging.

HDAC4 regulates satellite cell proliferation and differentiation by targeting P21 and Sharp1 genes.

Science.gov (United States)

Marroncelli, Nicoletta; Bianchi, Marzia; Bertin, Marco; Consalvi, Silvia; Saccone, Valentina; De Bardi, Marco; Puri, Pier Lorenzo; Palacios, Daniela; Adamo, Sergio; Moresi, Viviana

2018-02-22

Skeletal muscle exhibits a high regenerative capacity, mainly due to the ability of satellite cells to replicate and differentiate in response to appropriate stimuli. Epigenetic control is effective at different stages of this process. It has been shown that the chromatin-remodeling factor HDAC4 is able to regulate satellite cell proliferation and commitment. However, its molecular targets are still uncovered. To explain the signaling pathways regulated by HDAC4 in satellite cells, we generated tamoxifen-inducible mice with conditional inactivation of HDAC4 in Pax7 + cells (HDAC4 KO mice). We found that the proliferation and differentiation of HDAC4 KO satellite cells were compromised, although similar amounts of satellite cells were found in mice. Moreover, we found that the inhibition of HDAC4 in satellite cells was sufficient to block the differentiation process. By RNA-sequencing analysis we identified P21 and Sharp1 as HDAC4 target genes. Reducing the expression of these target genes in HDAC4 KO satellite cells, we also defined the molecular pathways regulated by HDAC4 in the epigenetic control of satellite cell expansion and fusion.

Differential requirement for satellite cells during overload-induced muscle hypertrophy in growing versus mature mice.

Science.gov (United States)

Murach, Kevin A; White, Sarah H; Wen, Yuan; Ho, Angel; Dupont-Versteegden, Esther E; McCarthy, John J; Peterson, Charlotte A

2017-07-10

Pax7+ satellite cells are required for skeletal muscle fiber growth during post-natal development in mice. Satellite cell-mediated myonuclear accretion also appears to persist into early adulthood. Given the important role of satellite cells during muscle development, we hypothesized that the necessity of satellite cells for adaptation to an imposed hypertrophic stimulus depends on maturational age. Pax7 CreER -R26R DTA mice were treated for 5 days with vehicle (satellite cell-replete, SC+) or tamoxifen (satellite cell-depleted, SC-) at 2 months (young) and 4 months (mature) of age. Following a 2-week washout, mice were subjected to sham surgery or 10 day synergist ablation overload of the plantaris (n = 6-9 per group). The surgical approach minimized regeneration, de novo fiber formation, and fiber splitting while promoting muscle fiber growth. Satellite cell density (Pax7+ cells/fiber), embryonic myosin heavy chain expression (eMyHC), and muscle fiber cross sectional area (CSA) were evaluated via immunohistochemistry. Myonuclei (myonuclei/100 mm) were counted on isolated single muscle fibers. Tamoxifen treatment depleted satellite cells by ≥90% and prevented myonuclear accretion with overload in young and mature mice (p overload. Average muscle fiber CSA increased ~20% in young SC+ (p = 0.07), mature SC+ (p overload (p overload-induced hypertrophy is dependent on maturational age, and global responses to overload differ in young versus mature mice.

Akt1 deficiency diminishes skeletal muscle hypertrophy by reducing satellite cell proliferation.

Science.gov (United States)

Moriya, Nobuki; Miyazaki, Mitsunori

2018-02-14

Skeletal muscle mass is determined by the net dynamic balance between protein synthesis and degradation. Although the Akt/mechanistic target of rapamycin (mTOR)-dependent pathway plays an important role in promoting protein synthesis and subsequent skeletal muscle hypertrophy, the precise molecular regulation of mTOR activity by the upstream protein kinase Akt is largely unknown. In addition, the activation of satellite cells has been indicated as a key regulator of muscle mass. However, the requirement of satellite cells for load-induced skeletal muscle hypertrophy is still under intense debate. In this study, female germline Akt1 knockout (KO) mice were used to examine whether Akt1 deficiency attenuates load-induced skeletal muscle hypertrophy through suppressing mTOR-dependent signaling and satellite cell proliferation. Akt1 KO mice showed a blunted hypertrophic response of skeletal muscle, with a diminished rate of satellite cell proliferation following mechanical overload. In contrast, Akt1 deficiency did not affect the load-induced activation of mTOR signaling and the subsequent enhanced rate of protein synthesis in skeletal muscle. These observations suggest that the load-induced activation of mTOR signaling occurs independently of Akt1 regulation and that Akt1 plays a critical role in regulating satellite cell proliferation during load-induced muscle hypertrophy.

Proteinase activity in cell nuclei of rats exposed to γ-radiation and methyl nitrosourea

International Nuclear Information System (INIS)

Malakhova, L.V.; Surkenova, G.N.; Gaziev, A.I.

1990-01-01

Activity of nuclear proteinases in blood and liver cells of rats exposed to whole-body γ-irradiation (10 Gy) has been comparatively studied by the capacity of splitting the caseic substrate. Proteinase activity in nuclei of irradiated rat leukocytes was shown to increase by 2.5 times and to gradually decrease after 48 h reaching 150-160% as compared to the control. Two hours following a single injection of methyl nitrosourea the alteration in the activity of proteinases in nuclei of rat hepatocytes and leukocytes was different from the alteration of this index after γ-irradiation

HEXIM1 controls satellite cell expansion after injury to regulate skeletal muscle regeneration

Science.gov (United States)

Hong, Peng; Chen, Kang; Huang, Bihui; Liu, Min; Cui, Miao; Rozenberg, Inna; Chaqour, Brahim; Pan, Xiaoyue; Barton, Elisabeth R.; Jiang, Xian-Cheng; Siddiqui, M.A.Q.

2012-01-01

The native capacity of adult skeletal muscles to regenerate is vital to the recovery from physical injuries and dystrophic diseases. Currently, the development of therapeutic interventions has been hindered by the complex regulatory network underlying the process of muscle regeneration. Using a mouse model of skeletal muscle regeneration after injury, we identified hexamethylene bisacetamide inducible 1 (HEXIM1, also referred to as CLP-1), the inhibitory component of the positive transcription elongation factor b (P-TEFb) complex, as a pivotal regulator of skeletal muscle regeneration. Hexim1-haplodeficient muscles exhibited greater mass and preserved function compared with those of WT muscles after injury, as a result of enhanced expansion of satellite cells. Transplanted Hexim1-haplodeficient satellite cells expanded and improved muscle regeneration more effectively than WT satellite cells. Conversely, HEXIM1 overexpression restrained satellite cell proliferation and impeded muscle regeneration. Mechanistically, dissociation of HEXIM1 from P-TEFb and subsequent activation of P-TEFb are required for satellite cell proliferation and the prevention of early myogenic differentiation. These findings suggest a crucial role for the HEXIM1/P-TEFb pathway in the regulation of satellite cell–mediated muscle regeneration and identify HEXIM1 as a potential therapeutic target for degenerative muscular diseases. PMID:23023707

Depletion of Pax7+ satellite cells does not affect diaphragm adaptations to running in young or aged mice.

Science.gov (United States)

Murach, Kevin A; Confides, Amy L; Ho, Angel; Jackson, Janna R; Ghazala, Lina S; Peterson, Charlotte A; Dupont-Versteegden, Esther E

2017-10-01

Satellite cell depletion does not affect diaphragm adaptations to voluntary wheel running in young or aged mice. Satellite cell depletion early in life (4 months of age) has minimal effect on diaphragm phenotype by old age (24 months). Prolonged satellite cell depletion in the diaphragm does not result in excessive extracellular matrix accumulation, in contrast to what has been reported in hind limb muscles. Up-regulation of Pax3 mRNA+ cells after satellite cell depletion in young and aged mice suggests that Pax3+ cells may compensate for a loss of Pax7+ satellite cells in the diaphragm. Future investigations should focus on the role of Pax3+ cells in the diaphragm during adaptation to exercise and ageing. Satellite cell contribution to unstressed diaphragm is higher compared to hind limb muscles, which is probably attributable to constant activation of this muscle to drive ventilation. Whether satellite cell depletion negatively impacts diaphragm quantitative and qualitative characteristics under stressed conditions in young and aged mice is unknown. We therefore challenged the diaphragm with prolonged running activity in the presence and absence of Pax7+ satellite cells in young and aged mice using an inducible Pax7 CreER -R26R DTA model. Mice were vehicle (Veh, satellite cell-replete) or tamoxifen (Tam, satellite cell-depleted) treated at 4 months of age and were then allowed to run voluntarily at 6 months (young) and 22 months (aged). Age-matched, cage-dwelling, Veh- and Tam-treated mice without wheel access served as activity controls. Diaphragm muscles were analysed from young (8 months) and aged (24 months) mice. Satellite cell depletion did not alter diaphragm mean fibre cross-sectional area, fibre type distribution or extracellular matrix content in young or aged mice, regardless of running activity. Resting in vivo diaphragm function was also unaffected by satellite cell depletion. Myonuclear density was maintained in young satellite cell

Development of a stained cell nuclei counting system

Science.gov (United States)

Timilsina, Niranjan; Moffatt, Christopher; Okada, Kazunori

2011-03-01

This paper presents a novel cell counting system which exploits the Fast Radial Symmetry Transformation (FRST) algorithm [1]. The driving force behind our system is a research on neurogenesis in the intact nervous system of Manduca Sexta or the Tobacco Hornworm, which was being studied to assess the impact of age, food and environment on neurogenesis. The varying thickness of the intact nervous system in this species often yields images with inhomogeneous background and inconsistencies such as varying illumination, variable contrast, and irregular cell size. For automated counting, such inhomogeneity and inconsistencies must be addressed, which no existing work has done successfully. Thus, our goal is to devise a new cell counting algorithm for the images with non-uniform background. Our solution adapts FRST: a computer vision algorithm which is designed to detect points of interest on circular regions such as human eyes. This algorithm enhances the occurrences of the stained-cell nuclei in 2D digital images and negates the problems caused by their inhomogeneity. Besides FRST, our algorithm employs standard image processing methods, such as mathematical morphology and connected component analysis. We have evaluated the developed cell counting system with fourteen digital images of Tobacco Hornworm's nervous system collected for this study with ground-truth cell counts by biology experts. Experimental results show that our system has a minimum error of 1.41% and mean error of 16.68% which is at least forty-four percent better than the algorithm without FRST.

β-Hydroxy-β-methylbutyrate (HMB) enhances the proliferation of satellite cells in fast muscles of aged rats during recovery from disuse atrophy.

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Alway, Stephen E; Pereira, Suzette L; Edens, Neile K; Hao, Yanlei; Bennett, Brian T

2013-09-01

Loss of myonuclei by apoptosis is thought to contribute to sarcopenia. We have previously shown, that the leucine metabolite, β-hydroxy-β-methylbutyrate (HMB) suppresses apoptotic signaling and the apoptotic index (the ratio of apoptotic positive to apoptotic negative myonuclei) during muscle disuse and during reloading periods after disuse in aged rats. However, it was not clear if the apoptotic signaling indexes were due only to preservation of myonuclei or if perhaps the total myogenic pool increased as a result of HMB-mediated satellite cell proliferation as this would have also reduced the apoptotic index. In this study, we tested the hypothesis that HMB would augment myogenic cells (satellite cells) proliferation during muscle recovery (growth) after a period of disuse in senescent animals. The hindlimb muscles of 34 month old Fisher 344 × Brown Norway rats were unloaded for 14 days by hindlimb suspension (HLS), and then reloaded for 14 days. The rats received either Ca-HMB (340 mg/kg body weight; n = 16), or the vehicle (n = 10) by gavage throughout the experimental period. HMB prevented the functional decline in maximal plantar flexion isometric force production during the reloading period, but not during HLS. HMB-treatment enhanced the proliferation of muscle stem cells as shown by a greater percentage of satellite cells that had proliferated (more BrdU positive, Pax-7 positive, and more Pax7/Ki67 positive nuclei) and as a result, more differentiated stem cells were present (more MyoD/myogenin positive myonuclei), relative to total myonuclei, in reloaded plantaris muscles as compared to reloaded muscles from vehicle-treated animals. Furthermore HMB increased the nuclear protein abundance of proliferation markers, inhibitor of differentiation-2 and cyclin A, as compared to vehicle treatment in reloaded muscles. Although HMB increased phosphorylated Akt during reloading, other mTOR related proteins were not altered by HMB treatment. These data show that

MASTR directs MyoD-dependent satellite cell differentiation during skeletal muscle regeneration

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Mokalled, Mayssa H.; Johnson, Aaron N.; Creemers, Esther E.; Olson, Eric N.

2012-01-01

In response to skeletal muscle injury, satellite cells, which function as a myogenic stem cell population, become activated, expand through proliferation, and ultimately fuse with each other and with damaged myofibers to promote muscle regeneration. Here, we show that members of the Myocardin family of transcriptional coactivators, MASTR and MRTF-A, are up-regulated in satellite cells in response to skeletal muscle injury and muscular dystrophy. Global and satellite cell-specific deletion of MASTR in mice impairs skeletal muscle regeneration. This impairment is substantially greater when MRTF-A is also deleted and is due to aberrant differentiation and excessive proliferation of satellite cells. These abnormalities mimic those associated with genetic deletion of MyoD, a master regulator of myogenesis, which is down-regulated in the absence of MASTR and MRTF-A. Consistent with an essential role of MASTR in transcriptional regulation of MyoD expression, MASTR activates a muscle-specific postnatal MyoD enhancer through associations with MEF2 and members of the Myocardin family. Our results provide new insights into the genetic circuitry of muscle regeneration and identify MASTR as a central regulator of this process. PMID:22279050

MASTR directs MyoD-dependent satellite cell differentiation during skeletal muscle regeneration

OpenAIRE

Mokalled, Mayssa H.; Johnson, Aaron N.; Creemers, Esther E.; Olson, Eric N.

2012-01-01

Muscle repair is regulated by satellite cells, adult skeletal muscle stem cells that control muscle regeneration by proliferating and fusing with injured myofibers. MyoD is required for muscle regeneration; however, the mechanisms regulating MyoD expression in satellite cells are unclear. In this study, Olson and colleagues have demonstrated that deletion of MASTR and MRTF-A, two members of the Myocardin family of transcription factors, leads to skeletal muscle regeneration defects and down-r...

The behaviour of satellite cells in response to exercise: what have we learned from human studies?

DEFF Research Database (Denmark)

Kadi, Fawzi; Olsen, Steen Schytte

2005-01-01

Understanding the complex role played by satellite cells in the adaptive response to exercise in human skeletal muscle has just begun. The development of reliable markers for the identification of satellite cell status (quiescence/activation/proliferation) is an important step towards the underst......Understanding the complex role played by satellite cells in the adaptive response to exercise in human skeletal muscle has just begun. The development of reliable markers for the identification of satellite cell status (quiescence/activation/proliferation) is an important step towards...

Flavanol binding of nuclei from tree species.

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Feucht, W; Treutter, D; Polster, J

2004-01-01

Light microscopy was used to examine the nuclei of five tree species with respect to the presence of flavanols. Flavanols develop a blue colouration in the presence of a special p-dimethylaminocinnamaldehyde (DMACA) reagent that enables those nuclei loaded with flavanols to be recognized. Staining of the nuclei was most pronounced in both Tsuga canadensis and Taxus baccata, variable in Metasequoia glyptostroboides, faint in Coffea arabica and minimal in Prunus avium. HPLC analysis showed that the five species contained substantial amounts of different flavanols such as catechin, epicatechin and proanthocyanidins. Quantitatively, total flavanols were quite different among the species. The nuclei themselves, as studied in Tsuga seed wings, were found to contain mainly catechin, much lower amounts of epicatechin and traces of proanthocyanidins. Blue-coloured nuclei located centrally in small cells were often found to maximally occupy up to 90% of a cell's radius, and the surrounding small rim of cytoplasm was visibly free of flavanols. A survey of 34 gymnosperm and angiosperm species indicated that the first group has much higher nuclear binding capacities for flavanols than the second group.

Characterisation of equine satellite cell transcriptomic profile response to β-hydroxy-β-methylbutyrate (HMB).

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Szcześniak, Katarzyna A; Ciecierska, Anna; Ostaszewski, Piotr; Sadkowski, Tomasz

2016-10-01

β-Hydroxy-β-methylbutyrate (HMB) is a popular ergogenic aid used by human athletes and as a supplement to sport horses, because of its ability to aid muscle recovery, improve performance and body composition. Recent findings suggest that HMB may stimulate satellite cells and affect expressions of genes regulating skeletal muscle cell growth. Despite the scientific data showing benefits of HMB supplementation in horses, no previous study has explained the mechanism of action of HMB in this species. The aim of this study was to reveal the molecular background of HMB action on equine skeletal muscle by investigating the transcriptomic profile changes induced by HMB in equine satellite cells in vitro. Upon isolation from the semitendinosus muscle, equine satellite cells were cultured until the 2nd day of differentiation. Differentiating cells were incubated with HMB for 24 h. Total cellular RNA was isolated, amplified, labelled and hybridised to microarray slides. Microarray data validation was performed with real-time quantitative PCR. HMB induced differential expressions of 361 genes. Functional analysis revealed that the main biological processes influenced by HMB in equine satellite cells were related to muscle organ development, protein metabolism, energy homoeostasis and lipid metabolism. In conclusion, this study demonstrated for the first time that HMB has the potential to influence equine satellite cells by controlling global gene expression. Genes and biological processes targeted by HMB in equine satellite cells may support HMB utility in improving growth and regeneration of equine skeletal muscle; however, the overall role of HMB in horses remains equivocal and requires further proteomic, biochemical and pharmacokinetic studies.

A Delaunay Triangulation Approach For Segmenting Clumps Of Nuclei

International Nuclear Information System (INIS)

Wen, Quan; Chang, Hang; Parvin, Bahram

2009-01-01

Cell-based fluorescence imaging assays have the potential to generate massive amount of data, which requires detailed quantitative analysis. Often, as a result of fixation, labeled nuclei overlap and create a clump of cells. However, it is important to quantify phenotypic read out on a cell-by-cell basis. In this paper, we propose a novel method for decomposing clumps of nuclei using high-level geometric constraints that are derived from low-level features of maximum curvature computed along the contour of each clump. Points of maximum curvature are used as vertices for Delaunay triangulation (DT), which provides a set of edge hypotheses for decomposing a clump of nuclei. Each hypothesis is subsequently tested against a constraint satisfaction network for a near optimum decomposition. The proposed method is compared with other traditional techniques such as the watershed method with/without markers. The experimental results show that our approach can overcome the deficiencies of the traditional methods and is very effective in separating severely touching nuclei.

Automatic extraction of nuclei centroids of mouse embryonic cells from fluorescence microscopy images.

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Md Khayrul Bashar

Full Text Available Accurate identification of cell nuclei and their tracking using three dimensional (3D microscopic images is a demanding task in many biological studies. Manual identification of nuclei centroids from images is an error-prone task, sometimes impossible to accomplish due to low contrast and the presence of noise. Nonetheless, only a few methods are available for 3D bioimaging applications, which sharply contrast with 2D analysis, where many methods already exist. In addition, most methods essentially adopt segmentation for which a reliable solution is still unknown, especially for 3D bio-images having juxtaposed cells. In this work, we propose a new method that can directly extract nuclei centroids from fluorescence microscopy images. This method involves three steps: (i Pre-processing, (ii Local enhancement, and (iii Centroid extraction. The first step includes two variations: first variation (Variant-1 uses the whole 3D pre-processed image, whereas the second one (Variant-2 modifies the preprocessed image to the candidate regions or the candidate hybrid image for further processing. At the second step, a multiscale cube filtering is employed in order to locally enhance the pre-processed image. Centroid extraction in the third step consists of three stages. In Stage-1, we compute a local characteristic ratio at every voxel and extract local maxima regions as candidate centroids using a ratio threshold. Stage-2 processing removes spurious centroids from Stage-1 results by analyzing shapes of intensity profiles from the enhanced image. An iterative procedure based on the nearest neighborhood principle is then proposed to combine if there are fragmented nuclei. Both qualitative and quantitative analyses on a set of 100 images of 3D mouse embryo are performed. Investigations reveal a promising achievement of the technique presented in terms of average sensitivity and precision (i.e., 88.04% and 91.30% for Variant-1; 86.19% and 95.00% for Variant-2

Development of Space Qualified Microlens Arrays for Solar Cells Used on Satellite Power Systems

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Ömer Faruk Keser

2017-08-01

Full Text Available The power system, one of the main systems of satellite, provides energy required for the satellite. Solar cells are also the most used energy source in the power system. The third generation multi-junction solar cells are known as the ones with highest performance. One of the methods to increase the performance of the solar cells is anti-reflective surface coatings with the Micro Lens Array-MLA. It's expected that satellite technologies has high power efficiency and low mass. The space environment has many effects like atomic oxygen, radiation and thermal cycles. Researches for increasing the solar cells performance shows that MLA coated solar cell has increased light absorption performance and less cell heating with very low additional mass. However, it is established that few studies on MLA coatings of solar cells are not applicable on space platforms. In this study, the process of development of MLA which is convenient to space power systems is investigated in a methodological way. In this context, a method which is developed based on MLA coatings of multi-junction solar cells for satellite power systems is presented.

The Satellite Cell Niche Regulates the Balance between Myoblast Differentiation and Self-Renewal via p53.

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Flamini, Valentina; Ghadiali, Rachel S; Antczak, Philipp; Rothwell, Amy; Turnbull, Jeremy E; Pisconti, Addolorata

2018-03-13

Satellite cells are adult muscle stem cells residing in a specialized niche that regulates their homeostasis. How niche-generated signals integrate to regulate gene expression in satellite cell-derived myoblasts is poorly understood. We undertook an unbiased approach to study the effect of the satellite cell niche on satellite cell-derived myoblast transcriptional regulation and identified the tumor suppressor p53 as a key player in the regulation of myoblast quiescence. After activation and proliferation, a subpopulation of myoblasts cultured in the presence of the niche upregulates p53 and fails to differentiate. When satellite cell self-renewal is modeled ex vivo in a reserve cell assay, myoblasts treated with Nutlin-3, which increases p53 levels in the cell, fail to differentiate and instead become quiescent. Since both these Nutlin-3 effects are rescued by small interfering RNA-mediated p53 knockdown, we conclude that a tight control of p53 levels in myoblasts regulates the balance between differentiation and return to quiescence. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Assessment of satellite cell number and activity status in human skeletal muscle biopsies

DEFF Research Database (Denmark)

Mackey, Abigail; Kjaer, Michael; Charifi, Nadia

2009-01-01

The primary aim of our study was to validate the assessment of myonuclear and satellite cell number in biopsies from human skeletal muscle. We found that 25 type I and 25 type II fibers are sufficient to estimate the mean number of myonuclei per fiber. In contrast, the assessment of satellite cells...

A unique combination of anatomy and physiology in cells of the rat paralaminar thalamic nuclei adjacent to the medial geniculate body

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Smith, Philip H.; Bartlett, Edward L.; Kowalkowski, Anna

2010-01-01

The medial geniculate body (MGB) has three major subdivisions - ventral (MGV), dorsal (MGD) and medial (MGM). MGM is linked with paralaminar nuclei that are situated medial and ventral to MGV/MGD. Paralaminar nuclei have unique inputs and outputs when compared with MGV and MGD and have been linked to circuitry underlying some important functional roles. We recorded intracellularly from cells in the paralaminar nuclei in vitro. We found that they possess an unusual combination of anatomical and physiological features when compared to those reported for “standard” thalamic neurons seen in the MGV/MGD and elsewhere in the thalamus. Compared to MGV/MGD neurons, anatomically, 1) paralaminar cell dendrites can be long, branch sparingly and encompass a much larger area. 2) their dendrites may be smooth but can have well defined spines and 3) their axons can have collaterals that branch locally within the same or nearby paralaminar nuclei. When compared to MGV/MGD neurons physiologically 1) their spikes are larger in amplitude and can be shorter in duration and 2) can have dual afterhyperpolarizations with fast and slow components and 3) they can have a reduction or complete absence of the low threshold, voltage-sensitive calcium conductance that reduces or eliminates the voltage-dependent burst response. We also recorded from cells in the parafascicular nucleus, a nucleus of the posterior intralaminar nuclear group, because they have unusual anatomical features that are similar to some of our paralaminar cells. Like the labeled paralaminar cells, parafascicular cells had physiological features distinguishing them from typical thalamic neurons. PMID:16566009

[The coiled bodies and satellite microbodies of the oocyte nuclei in hibernating Rana temporaria frogs contain actin].

Science.gov (United States)

Tsvetkov, A G; Kvasov, I D; Khaĭtlina, S Iu; Parfenov, V N

1997-01-01

Immunocytochemical analysis of preparation of dispersed nuclei content in oocytes of III-IV stages of oogenesis, in terms of Dumont (1972), from hibernating grass frogs using monoclonal antibodies against actin, revealed two types of intranuclear structures containing this protein: coiled bodies (CB) and satellite microbodies (SM). Staining of these preparations with Rhodamin-phalloidin, known specifically to interact with fibrillar actin, did not reveal it in these structures. Results of our biochemical studies, using protease ESP32 specifically cutting only globular actin, are suggesting that both CB and SM contain globular actin. Gall et al. (1975) proposed that CB may be involved in assembling and sorting of small nuclear RNA for the three main RNA processing pathways: pre-mRNA splicing, pre-rRNA processing, and histone pre-mRNA 3'-end formation. Our finding of actin in CB allows a suggestion on actin involvement in the transport of RNA processing complexes from CB to some actual places where processing of RNA takes place. According to our previous data (Tsvetkov, Parfenov., 1994), SM participate in the karyosphere capsule formation. This process is preceded by SM fusion triggered presumably by actin.

The effects of low frequency electrical stimulation on satellite cell activity in rat skeletal muscle during hindlimb suspension

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Zhang Hong-Yu

2010-11-01

Full Text Available Abstract Background The ability of skeletal muscle to grow and regenerate is dependent on resident stem cells called satellite cells. It has been shown that chronic hindlimb unloading downregulates the satellite cell activity. This study investigated the role of low-frequency electrical stimulation on satellite cell activity during a 28 d hindlimb suspension in rats. Results Mechanical unloading resulted in a 44% reduction in the myofiber cross-sectional area as well as a 29% and 34% reduction in the number of myonuclei and myonuclear domains, respectively, in the soleus muscles (P vs the weight-bearing control. The number of quiescent (M-cadherin+, proliferating (BrdU+ and myoD+, and differentiated (myogenin+ satellite cells was also reduced by 48-57% compared to the weight-bearing animals (P P Conclusion This study shows that electrical stimulation partially attenuated the decrease in muscle size and satellite cells during hindlimb unloading. The causal relationship between satellite cell activation and electrical stimulation remain to be established.

Computational Topology Based Quantification Of Hepatocytes Nuclei In Lipopolysaccharide-Induced Liver Injury In Mice

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Rodrigo Rojas Moraleda

2016-06-01

The computational topology approach proposed successfully detected hepatocyte cells under several natural variations. We evaluated on a per-pixel basis how the segmentation performs on: i all nuclei in the images, ii big round nuclei considered belonging to hepatocytes cells (accuracy 87.2%, recall 80.3%, and iii nuclei regarded to non-parenchymal cells.  

More efficient repair of DNA double-strand breaks in skeletal muscle stem cells compared to their committed progeny

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Leyla Vahidi Ferdousi

2014-11-01

Full Text Available The loss of genome integrity in adult stem cells results in accelerated tissue aging and is possibly cancerogenic. Adult stem cells in different tissues appear to react robustly to DNA damage. We report that adult skeletal stem (satellite cells do not primarily respond to radiation-induced DNA double-strand breaks (DSBs via differentiation and exhibit less apoptosis compared to other myogenic cells. Satellite cells repair these DNA lesions more efficiently than their committed progeny. Importantly, non-proliferating satellite cells and post-mitotic nuclei in the fiber exhibit dramatically distinct repair efficiencies. Altogether, reduction of the repair capacity appears to be more a function of differentiation than of the proliferation status of the muscle cell. Notably, satellite cells retain a high efficiency of DSB repair also when isolated from the natural niche. Finally, we show that repair of DSB substrates is not only very efficient but, surprisingly, also very accurate in satellite cells and that accurate repair depends on the key non-homologous end-joining factor DNA-PKcs.

More efficient repair of DNA double-strand breaks in skeletal muscle stem cells compared to their committed progeny.

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Vahidi Ferdousi, Leyla; Rocheteau, Pierre; Chayot, Romain; Montagne, Benjamin; Chaker, Zayna; Flamant, Patricia; Tajbakhsh, Shahragim; Ricchetti, Miria

2014-11-01

The loss of genome integrity in adult stem cells results in accelerated tissue aging and is possibly cancerogenic. Adult stem cells in different tissues appear to react robustly to DNA damage. We report that adult skeletal stem (satellite) cells do not primarily respond to radiation-induced DNA double-strand breaks (DSBs) via differentiation and exhibit less apoptosis compared to other myogenic cells. Satellite cells repair these DNA lesions more efficiently than their committed progeny. Importantly, non-proliferating satellite cells and post-mitotic nuclei in the fiber exhibit dramatically distinct repair efficiencies. Altogether, reduction of the repair capacity appears to be more a function of differentiation than of the proliferation status of the muscle cell. Notably, satellite cells retain a high efficiency of DSB repair also when isolated from the natural niche. Finally, we show that repair of DSB substrates is not only very efficient but, surprisingly, also very accurate in satellite cells and that accurate repair depends on the key non-homologous end-joining factor DNA-PKcs. Copyright © 2014. Published by Elsevier B.V.

Systematic Morphometry of Catecholamine Nuclei in the Brainstem.

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Bucci, Domenico; Busceti, Carla L; Calierno, Maria T; Di Pietro, Paola; Madonna, Michele; Biagioni, Francesca; Ryskalin, Larisa; Limanaqi, Fiona; Nicoletti, Ferdinando; Fornai, Francesco

2017-01-01

Catecholamine nuclei within the brainstem reticular formation (RF) play a pivotal role in a variety of brain functions. However, a systematic characterization of these nuclei in the very same experimental conditions is missing so far. Tyrosine hydroxylase (TH) immune-positive cells of the brainstem correspond to dopamine (DA)-, norepinephrine (NE)-, and epinephrine (E)-containing cells. Here, we report a systematic count of TH-positive neurons in the RF of the mouse brainstem by using stereological morphometry. All these nuclei were analyzed for anatomical localization, rostro-caudal extension, volume, neuron number, neuron density, and mean neuronal area for each nucleus. The present data apart from inherent informative value wish to represent a reference for neuronal mapping in those studies investigating the functional anatomy of the brainstem RF. These include: the sleep-wake cycle, movement control, muscle tone modulation, mood control, novelty orienting stimuli, attention, archaic responses to internal and external stressful stimuli, anxiety, breathing, blood pressure, and innumerable activities modulated by the archaic iso-dendritic hard core of the brainstem RF. Most TH-immune-positive cells fill the lateral part of the RF, which indeed possesses a high catecholamine content. A few nuclei are medial, although conventional nosography considers all these nuclei as part of the lateral column of the RF. Despite the key role of these nuclei in psychiatric and neurological disorders, only a few of them aspired a great attention in biomedical investigation, while most of them remain largely obscure although intense research is currently in progress. A simultaneous description of all these nuclei is not simply key to comprehend the variety of brainstem catecholamine reticular neurons, but probably represents an intrinsically key base for understanding brain physiology and physiopathology.

Systematic Morphometry of Catecholamine Nuclei in the Brainstem

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Domenico Bucci

2017-11-01

Full Text Available Catecholamine nuclei within the brainstem reticular formation (RF play a pivotal role in a variety of brain functions. However, a systematic characterization of these nuclei in the very same experimental conditions is missing so far. Tyrosine hydroxylase (TH immune-positive cells of the brainstem correspond to dopamine (DA-, norepinephrine (NE-, and epinephrine (E-containing cells. Here, we report a systematic count of TH-positive neurons in the RF of the mouse brainstem by using stereological morphometry. All these nuclei were analyzed for anatomical localization, rostro-caudal extension, volume, neuron number, neuron density, and mean neuronal area for each nucleus. The present data apart from inherent informative value wish to represent a reference for neuronal mapping in those studies investigating the functional anatomy of the brainstem RF. These include: the sleep-wake cycle, movement control, muscle tone modulation, mood control, novelty orienting stimuli, attention, archaic responses to internal and external stressful stimuli, anxiety, breathing, blood pressure, and innumerable activities modulated by the archaic iso-dendritic hard core of the brainstem RF. Most TH-immune-positive cells fill the lateral part of the RF, which indeed possesses a high catecholamine content. A few nuclei are medial, although conventional nosography considers all these nuclei as part of the lateral column of the RF. Despite the key role of these nuclei in psychiatric and neurological disorders, only a few of them aspired a great attention in biomedical investigation, while most of them remain largely obscure although intense research is currently in progress. A simultaneous description of all these nuclei is not simply key to comprehend the variety of brainstem catecholamine reticular neurons, but probably represents an intrinsically key base for understanding brain physiology and physiopathology.

Impaired energy metabolism of senescent muscle satellite cells is associated with oxidative modifications of glycolytic enzymes

DEFF Research Database (Denmark)

Baraibar, Martín A; Hyzewicz, Janek; Rogowska-Wrzesinska, Adelina

2016-01-01

Accumulation of oxidized proteins is a hallmark of cellular and organismal aging. Adult muscle stem cell (or satellite cell) replication and differentiation is compromised with age contributing to sarcopenia. However, the molecular events related to satellite cell dysfunction during aging are not...

Retained Myogenic Potency of Human Satellite Cells from Torn Rotator Cuff Muscles Despite Fatty Infiltration.

Science.gov (United States)

Koide, Masashi; Hagiwara, Yoshihiro; Tsuchiya, Masahiro; Kanzaki, Makoto; Hatakeyama, Hiroyasu; Tanaka, Yukinori; Minowa, Takashi; Takemura, Taro; Ando, Akira; Sekiguchi, Takuya; Yabe, Yutaka; Itoi, Eiji

2018-01-01

Rotator cuff tears (RCTs) are a common shoulder problem in the elderly that can lead to both muscle atrophy and fatty infiltration due to less physical load. Satellite cells, quiescent cells under the basal lamina of skeletal muscle fibers, play a major role in muscle regeneration. However, the myogenic potency of human satellite cells in muscles with fatty infiltration is unclear due to the difficulty in isolating from small samples, and the mechanism of the progression of fatty infiltration has not been elucidated. The purpose of this study was to analyze the population of myogenic and adipogenic cells in disused supraspinatus (SSP) and intact subscapularis (SSC) muscles of the RCTs from the same patients using fluorescence-activated cell sorting. The microstructure of the muscle with fatty infiltration was observed as a whole mount condition under multi-photon microscopy. Myogenic differentiation potential and gene expression were evaluated in satellite cells. The results showed that the SSP muscle with greater fatty infiltration surrounded by collagen fibers compared with the SSC muscle under multi-photon microscopy. A positive correlation was observed between the ratio of muscle volume to fat volume and the ratio of myogenic precursor to adipogenic precursor. Although no difference was observed in the myogenic potential between the two groups in cell culture, satellite cells in the disused SSP muscle showed higher intrinsic myogenic gene expression than those in the intact SSC muscle. Our results indicate that satellite cells from the disused SSP retain sufficient potential of muscle growth despite the fatty infiltration.

Stochastic cellular automata model of cell migration, proliferation and differentiation: validation with in vitro cultures of muscle satellite cells.

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Garijo, N; Manzano, R; Osta, R; Perez, M A

2012-12-07

Cell migration and proliferation has been modelled in the literature as a process similar to diffusion. However, using diffusion models to simulate the proliferation and migration of cells tends to create a homogeneous distribution in the cell density that does not correlate to empirical observations. In fact, the mechanism of cell dispersal is not diffusion. Cells disperse by crawling or proliferation, or are transported in a moving fluid. The use of cellular automata, particle models or cell-based models can overcome this limitation. This paper presents a stochastic cellular automata model to simulate the proliferation, migration and differentiation of cells. These processes are considered as completely stochastic as well as discrete. The model developed was applied to predict the behaviour of in vitro cell cultures performed with adult muscle satellite cells. Moreover, non homogeneous distribution of cells has been observed inside the culture well and, using the above mentioned stochastic cellular automata model, we have been able to predict this heterogeneous cell distribution and compute accurate quantitative results. Differentiation was also incorporated into the computational simulation. The results predicted the myotube formation that typically occurs with adult muscle satellite cells. In conclusion, we have shown how a stochastic cellular automata model can be implemented and is capable of reproducing the in vitro behaviour of adult muscle satellite cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

Analyses of the differentiation potential of satellite cells from myoD-/-, mdx, and PMP22 C22 mice

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Huxley Clare

2005-03-01

Full Text Available Abstract Background Sporadic and sometimes contradictory studies have indicated changes in satellite cell behaviour associated with the progressive nature of human Duchenne muscular dystrophy (DMD. Satellite cell proliferation and number are reportedly altered in DMD and the mdx mouse model. We recently found that satellite cells in MSVski transgenic mice, a muscle hypertrophy model showing progressive muscle degeneration, display a severe ageing-related differentiation defect in vitro. We tested the hypothesis that similar changes contribute to the gradual loss of muscle function with age in mdx and PMP22 mice, a model of human motor and sensory neuropathy type 1A (HMSN1A. Methods Single extensor digitorum longus muscle fibres were cultured from mdx and PMP22 mice and age- and genetic background-matched controls. Mice at several ages were compared with regard to the differentiation of satellite cells, assayed as the proportion of desmin-expressing cells that accumulated sarcomeric myosin heavy chain. Results Satellite cells of 2 month, 6 month, and 12 month old mdx mice were capable of differentiating to a similar extent to age-matched wild type control animals in an in vitro proliferation/differentiation model. Strikingly, differentiation efficiency in individual 6 month and 12 month old mdx animals varies to a much higher extent than in age-matched controls, younger mdx animals, or PMP22 mice. In contrast, differentiation of myoblasts from all myoD null mice assayed was severely impaired in this assay system. The defect in satellite cell differentiation that occurs in some mdx animals arises from a delay in differentiation that is not overcome by IGF-1 treatment at any phase of cultivation. Conclusion Overall, a defect in satellite cell differentiation above that arising through normal ageing does not occur in mdx or PMP22 mouse models of human disease. Nonetheless, the impaired differentiation of satellite cells from some mdx animals

ADAMTS-1 Is Found in the Nuclei of Normal and Tumoral Breast Cells.

Directory of Open Access Journals (Sweden)

Suély V Silva

Full Text Available Proteins secreted in the extracellular matrix microenvironment (ECM by tumor cells are involved in cell adhesion, motility, intercellular communication and invasion. The tumor microenvironment is expansively modified and remodeled by proteases, resulting in important changes in both cell-cell and cell-ECM interactions and in the generation of new signals from the cell surface. Metalloproteinases belonging to the ADAMTS (a disintegrin and metalloprotease with thrombospondin motifs family have been implicated in tissue remodeling events observed in cancer development, growth and progression. Here we investigated the subcellular localization of ADAMTS-1 in normal-like (MCF10-A and tumoral (MCF7 and MDA-MB-231 human breast cells. ADAMTS-1 is a secreted protease found in the extracellular matrix. However, in this study we show for the first time that ADAMTS-1 is also present in the nuclei and nucleoli of the three mammary cell lines studied here. Our findings indicate that ADAMTS-1 has proteolytic functions in the nucleus through its interaction with aggrecan substrate.

Reduced Dnmt3a increases Gdf5 expression with suppressed satellite cell differentiation and impaired skeletal muscle regeneration.

Science.gov (United States)

Hatazawa, Yukino; Ono, Yusuke; Hirose, Yuma; Kanai, Sayaka; Fujii, Nobuharu L; Machida, Shuichi; Nishino, Ichizo; Shimizu, Takahiko; Okano, Masaki; Kamei, Yasutomi; Ogawa, Yoshihiro

2018-03-01

DNA methylation is an epigenetic mechanism regulating gene expression. In this study, we observed that DNA methyltransferase 3a (Dnmt3a) expression is decreased after muscle atrophy. We made skeletal muscle-specific Dnmt3a-knockout (Dnmt3a-KO) mice. The regeneration capacity after muscle injury was markedly decreased in Dnmt3a-KO mice. Diminished mRNA and protein expression of Dnmt3a were observed in skeletal muscles as well as in satellite cells, which are important for muscle regeneration, in Dnmt3a-KO mice. Dnmt3a-KO satellite cell showed smaller in size (length/area), suggesting suppressed myotube differentiation. Microarray analysis of satellite cells showed that expression of growth differentiation factor 5 (Gdf5) mRNA was markedly increased in Dnmt3a-KO mice. The DNA methylation level of the Gdf5 promoter was markedly decreased in Dnmt3a-KO satellite cells. In addition, DNA methylation inhibitor azacytidine treatment increased Gdf5 expression in wild-type satellite cells, suggesting Gdf5 expression is regulated by DNA methylation. Also, we observed increased inhibitor of differentiation (a target of Gdf5) mRNA expression in Dnmt3a-KO satellite cells. Thus, Dnmt3a appears to regulate satellite cell differentiation via DNA methylation. This mechanism may play a role in the decreased regeneration capacity during atrophy such as in aged sarcopenia.-Hatazawa, Y., Ono, Y., Hirose, Y., Kanai, S., Fujii, N. L., Machida, S., Nishino, I., Shimizu, T., Okano, M., Kamei, Y., Ogawa, Y. Reduced Dnmt3a increases Gdf5 expression with suppressed satellite cell differentiation and impaired skeletal muscle regeneration.

Pseudomagic nuclei

International Nuclear Information System (INIS)

Scharff-Goldhaber, G.

1979-01-01

It was shown previously that, below a critical angular momentum, yrast bands of nonmagic nuclei are well described by the two-parameter variable moment of inertia model. Some striking exceptions to this rule are found in nuclei which have the same mass number as doubly magic nuclei but possess either one (or two) proton pairs beyond a magic number and one (or two) neutron hole pairs, or vice versa. Yrast bands in these pseudomagic nuclei resemble those in magic nuclei. 17 references

Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

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Chatterjee, Somik [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Yin, Hongshan [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Department of Cardiovascular Medicine, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050051, Hebei (China); Nam, Deokhwa [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Li, Yong [Department of Pediatric Surgery, Center for Stem Cell Research and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030 (United States); Ma, Ke, E-mail: kma@houstonmethodist.org [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States)

2015-02-01

Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1{sup −/−} mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation.

Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

International Nuclear Information System (INIS)

Chatterjee, Somik; Yin, Hongshan; Nam, Deokhwa; Li, Yong; Ma, Ke

2015-01-01

Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1 −/− mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation

Mobilisation of satellite cells following ischaemia and reperfusion in ...

African Journals Online (AJOL)

Objective. To describe the morphological and morphometric features of activated skeletal muscle satellite cells in primates, using an ischaemic reperfusion model. Setting. The study was undertaken at the Biomedical Resource Centre and the Electron Microscopy Unit of the University of KwaZulu-Natal. Interventions.

Effect of incubation temperature on neuropeptide Y and neuropeptide Y receptors in turkey and chicken satellite cells.

Science.gov (United States)

Clark, Daniel L; McCormick, Janet L; Velleman, Sandra G

2018-05-01

Neuropeptide Y (NPY) is an appetite stimulating peptide released from the central nervous system and impacts the function of many different cell types. A recent transcriptome study showed that NPY expression was altered when turkey breast muscle satellite cells were incubated at low or high temperatures, suggesting NPY may mediate temperature effects on satellite cells. However, to date minimal information exists describing the expression and function of NPY in satellite cells. The objective of this study was to determine how temperature impacts NPY and NPY receptor gene expression in satellite cells isolated from turkeys and chickens with differing genetic lineages. Two broiler and two turkey breast muscle satellite cell lines were incubated at 35, 38 or 41 °C during proliferation and differentiation. In both turkey lines, NPY, and receptors NPY2R and NPY5R expression increased at elevated temperatures after 72 h of proliferation. During differentiation NPY and NPY5R expression increased in both turkey lines with higher temperatures, whereas NPY2R was minimally affected by temperature. In contrast, in both chicken cell lines there were few significant differences for NPY and NPY receptor expression across temperature during proliferation. During differentiation, the temperature effect was different in the two chicken cell lines. In the BPM8 chicken line, there were few differences in NPY and NPY receptors across temperature; whereas elevated temperatures increased NPY, NPY2R, and NPY5R expression in the 708 line. The differences between turkey and chicken lines suggest NPY has species specific satellite cell functions in response to heat stress. Copyright © 2018 Elsevier Inc. All rights reserved.

Identification of a major non-structural protein in the nuclei of Rift Valley fever virus-infected cells.

Science.gov (United States)

Struthers, J K; Swanepoel, R

1982-06-01

A non-structural protein of mol. wt. 34 X 10(3) was demonstrated in the nuclei of Rift Valley fever virus-infected Vero cells by SDS-polyacrylamide gel electro-phoresis. The protein appears to correspond to the virus-induced antigen demonstrated by indirect immunofluorescence in intranuclear inclusions.

[The distribution of NADPH-diaphorase and neuronal no synthase in rat medulla oblongata nuclei].

Science.gov (United States)

Chertok, V M; Kotsuba, A E

2013-01-01

The distribution of nitroxide ergic neurons in the medulla oblongata nuclei in Wistar rats (n = 8) was studied histochemically (NADPH-diaphorase) and using immunohistochemistry with an antiserum against neuronal form of nitric oxide synthase (nNOS). NADPH-diaphorase activity was found in large and small neurons of the sensory, autonomic and motor nuclei. The latter were especially rich in the cells demonstrating the activity of the enzyme. Unlike NADPH-diaphorase, nNOS in the corresponding nuclei was always detected in the fewer number of neurons, predominantly of small sizes. The sensory nuclei (nucleus of solitary tract, reticular parvocellular and lateral nuclei, spinal nucleus of the trigeminal nerve) contained 1.5-3 times more nNOS neurons than in motor nuclei. In some nuclei (nucleus ambiguus, hypoglossal nerve nucleus), containing numerous NADPH-diaphorase-positive neurons, immunoreactive cells were particularly rare.

Satellite cell frequency in cross-age transplanted rat extensor digitorum longus muscles

Czech Academy of Sciences Publication Activity Database

Rudež, M.; Carlson, B. M.; Sajko, Š.; Kubínová, Lucie; Wernig, A.; Eržen, I.

2004-01-01

Roč. 14, č. 3 (2004), s. 155-159 ISSN 1120-9992 Grant - others:European programme(XE) QLKG-1999-02034 Institutional research plan: CEZ:AV0Z5011922 Keywords : aging * confocal microscopy * satellite cell s Subject RIV: EA - Cell Biology

Advanced Solar Cells for Satellite Power Systems

Science.gov (United States)

Flood, Dennis J.; Weinberg, Irving

1994-01-01

The multiple natures of today's space missions with regard to operational lifetime, orbital environment, cost and size of spacecraft, to name just a few, present such a broad range of performance requirements to be met by the solar array that no single design can suffice to meet them all. The result is a demand for development of specialized solar cell types that help to optimize overall satellite performance within a specified cost range for any given space mission. Historically, space solar array performance has been optimized for a given mission by tailoring the features of silicon solar cells to account for the orbital environment and average operating conditions expected during the mission. It has become necessary to turn to entirely new photovoltaic materials and device designs to meet the requirements of future missions, both in the near and far term. This paper will outline some of the mission drivers and resulting performance requirements that must be met by advanced solar cells, and provide an overview of some of the advanced cell technologies under development to meet them. The discussion will include high efficiency, radiation hard single junction cells; monolithic and mechanically stacked multiple bandgap cells; and thin film cells.

Location of DNA-protein cross-links in mammalian cell nuclei

International Nuclear Information System (INIS)

Oleinick, N.L.

1985-01-01

DNA-protein cross-links (DPCs) occur in 1-3% of the bulk DNA of unirradiated cells, and dose-dependent increases in DPCs with γ- or UV-radiation can be detected by filter-binding. DPCs may contribute to cell lethality, since their formation is prevented by radical scavengers. Since the environment of DNA varies within eukaryotic nuclei, we have probed the composition and sub-nuclear location of DPCs. Both before and after irradiation, the major proteins cross-linked to DNA have molecular weights similar to known proteins of the nuclear matrix. The DNA cross-linked to protein is enriched in sequences which hybridize to mRNA or rRNA transcripts; such sequences are also found preferentially in preparations of nuclear matrix. When histone-depleted, matrix-associated DNA is separated from the DNA of the supercoiled ''loops'' by digestion with EcoRI and assayed for DPCs by filter binding, the frequency of DPCs is greater in the matrix. During repair of DPCs, protein-associated DNA becomes depleted in actively transcribing DNA, followed by reconstitution of the active-gene-enriched nuclear matrix. These data are consistent with known properties of the matrix and suggest the hypothesis that in intact cells, radiation-induced DPCs are primarily a product of matrix-associated DNA sequences and matrix protein

Selective localization of neptunium-237 in the nuclei of mammalian cells. Localisation selective du neptunium-237 au sein des noyaux des cellules de mammiferes

Energy Technology Data Exchange (ETDEWEB)

Galle, P.; Boulahdour, H. (Faculte de Medecine, 94 - Creteil (FR)); Metivier, H. (CEA Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (FR). Inst. de Protection et de Surete Nucleaire)

1992-01-01

After injection in the rat of soluble neptunium salt, the distribution of this element was studied at the subcellular level by electron microscopy and electron probe microanalysis. Abnormal structures have been observed by electron microscopy in the nuclei of hepatocytes, and the same structures have also been observed in the nuclei of the proximal tubules cells of the kidney. These structures are formed of clusters of very small and dense particles, several nanometers in diameter. The clusters are localized in the central part of the nuclei and they are separate from nucleoli and heterochromatin. Electron probe X-ray analysis of this cluster have shown that they contain neptunium associated with phosphorus. In the cell containing neptunium inclusions, other non specific lesions are also observed (nuclear pycnosis, mitochondrial depletion).

Early-age feed restriction affects viability and gene expression of satellite cells isolated from the gastrocnemius muscle of broiler chicks

Directory of Open Access Journals (Sweden)

Li Yue

2012-11-01

Full Text Available Abstract Background Muscle growth depends on the fusion of proliferate satellite cells to existing myofibers. We reported previously that 0–14 day intermittent feeding led to persistent retardation in myofiber hypertrophy. However, how satellite cells respond to such nutritional insult has not been adequately elucidated. Results One-day-old broiler chicks were allocated to control (Con, ad libitum feeding, intermittent feeding (IF, feed provided on alternate days and re-feeding (RF, 2 days ad libitum feeding after 12 days of intermittent feeding groups. Chickens were killed on Day 15 and satellite cells were isolated. When cultured, satellite cells from the IF group demonstrated significant retardation in proliferation and differentiation potential, while RF partly restored the proliferation rate and differentiation potential of the satellite cells. Significant up-regulation of insulin like growth factor I receptor (IGF-IR (P0.05 and thyroid hormone receptor α (TRα (P0.05, and down-regulation of growth hormone receptor (GHR (P0.01 and IGF-I (P0.01 mRNA expression was observed in freshly isolated IF satellite cells when compared with Con cells. In RF cells, the mRNA expression of IGF-I was higher (P0.05 and of TRα was lower (P0.01 than in IF cells, suggesting that RF restored the mRNA expression of TRα and IGF-I, but not of GHR and IGF-IR. The Bax/Bcl-2 ratio tended to increase in the IF group, which was reversed in the RF group (P0.05, indicating that RF reduced the pro-apoptotic influence of IF. Moreover, no significant effect of T3 was detected on cell survival in IF cells compared with Con (PP0.05 cells. Conclusions These data suggest that early-age feed restriction inhibits the proliferation and differentiation of satellite cells, induces changes in mRNA expression of the GH/IGF-I and thyroid hormone receptors in satellite cells, as well as blunted sensitivity of satellite cells to T3, and that RF partially reverses these effects. Thus

Outer nuclear membrane fusion of adjacent nuclei in varicella-zoster virus-induced syncytia.

Science.gov (United States)

Wang, Wei; Yang, Lianwei; Huang, Xiumin; Fu, Wenkun; Pan, Dequan; Cai, Linli; Ye, Jianghui; Liu, Jian; Xia, Ningshao; Cheng, Tong; Zhu, Hua

2017-12-01

Syncytia formation has been considered important for cell-to-cell spread and pathogenesis of many viruses. As a syncytium forms, individual nuclei often congregate together, allowing close contact of nuclear membranes and possibly fusion to occur. However, there is currently no reported evidence of nuclear membrane fusion between adjacent nuclei in wild-type virus-induced syncytia. Varicella-zoster virus (VZV) is one typical syncytia-inducing virus that causes chickenpox and shingles in humans. Here, we report, for the first time, an interesting observation of apparent fusion of the outer nuclear membranes from juxtaposed nuclei that comprise VZV syncytia both in ARPE-19 human epithelial cells in vitro and in human skin xenografts in the SCID-hu mouse model in vivo. This work reveals a novel aspect of VZV-related cytopathic effect in the context of multinucleated syncytia. Additionally, the information provided by this study could be helpful for future studies on interactions of viruses with host cell nuclei. Copyright © 2017 Elsevier Inc. All rights reserved.

MASTR directs MyoD-dependent satellite cell differentiation during skeletal muscle regeneration

NARCIS (Netherlands)

Mokalled, Mayssa H.; Johnson, Aaron N.; Creemers, Esther E.; Olson, Eric N.

2012-01-01

In response to skeletal muscle injury, satellite cells, which function as a myogenic stem cell population, become activated, expand through proliferation, and ultimately fuse with each other and with damaged myofibers to promote muscle regeneration. Here, we show that members of the Myocardin family

Automated objective determination of percentage of malignant nuclei for mutation testing.

Science.gov (United States)

Viray, Hollis; Coulter, Madeline; Li, Kevin; Lane, Kristin; Madan, Aruna; Mitchell, Kisha; Schalper, Kurt; Hoyt, Clifford; Rimm, David L

2014-01-01

Detection of DNA mutations in tumor tissue can be a critical companion diagnostic test before prescription of a targeted therapy. Each method for detection of these mutations is associated with an analytic sensitivity that is a function of the percentage of tumor cells present in the specimen. Currently, tumor cell percentage is visually estimated resulting in an ordinal and highly variant result for a biologically continuous variable. We proposed that this aspect of DNA mutation testing could be standardized by developing a computer algorithm capable of accurately determining the percentage of malignant nuclei in an image of a hematoxylin and eosin-stained tissue. Using inForm software, we developed an algorithm, to calculate the percentage of malignant cells in histologic specimens of colon adenocarcinoma. A criterion standard was established by manually counting malignant and benign nuclei. Three pathologists also estimated the percentage of malignant nuclei in each image. Algorithm #9 had a median deviation from the criterion standard of 5.4% on the training set and 6.2% on the validation set. Compared with pathologist estimation, Algorithm #9 showed a similar ability to determine percentage of malignant nuclei. This method represents a potential future tool to assist in determining the percent of malignant nuclei present in a tissue section. Further validation of this algorithm or an improved algorithm may have value to more accurately assess percentage of malignant cells for companion diagnostic mutation testing.

Proton irradiation effects of amorphous silicon solar cell for solar power satellite

Energy Technology Data Exchange (ETDEWEB)

Morita, Yousuke; Oshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Sasaki, Susumu; Kuroda, Hideo; Ushirokawa, Akio

1997-03-01

Flexible amorphous silicon(fa-Si) solar cell module, a thin film type, is regarded as a realistic power generator for solar power satellite. The radiation resistance of fa-Si cells was investigated by the irradiations of 3,4 and 10 MeV protons. The hydrogen gas treatment of the irradiated fa-Si cells was also studied. The fa-Si cell shows high radiation resistance for proton irradiations, compared with a crystalline silicon solar cell. (author)

''Tailed'' nuclei are a possible cell marker of radiational effects

International Nuclear Information System (INIS)

Kravtsov, V.Yu.; Starkova, E.V.; Nikiforov, A.M.; Fedortseva, R.F.; Loginova, Yu.A.; Yakovlev, A.F.

1997-01-01

Study of peripheral blood smears from irradiated patients (liquidators of consequences of the Chernobyl Atomic Electric Plant accident) has shown nuclei of some lymphocytes to have a protrusion into the cytoplasm. Such abnormal nuclei are called ''tailed'' nuclei (TN). The mean frequency of appearance of lymphocytes with TN in the group of irradiated patients (n=136) amounted to 0.59%, whereas in the group of healthy donors (n=50), 0.15% (the difference between the groups is statistically significant). The correlation coefficient between the indicators ''frequency of lymphocytes with NT'' and ''frequency of lymphocytes with dicentric chromosomes'' was 0.73 (n=47, p<0.001). By the method of bicolour FISH there was revealed localization of the near-centromere (not more than two signals) and telomere (not more than one signal) regions in the nuclear ''tails''. Abnormalities of the TN type in lymphocytes are likely to result from breakdowns of chromosomal bridges formed by dicentric chromosomes. (author)

I-motif DNA structures are formed in the nuclei of human cells

Science.gov (United States)

Zeraati, Mahdi; Langley, David B.; Schofield, Peter; Moye, Aaron L.; Rouet, Romain; Hughes, William E.; Bryan, Tracy M.; Dinger, Marcel E.; Christ, Daniel

2018-06-01

Human genome function is underpinned by the primary storage of genetic information in canonical B-form DNA, with a second layer of DNA structure providing regulatory control. I-motif structures are thought to form in cytosine-rich regions of the genome and to have regulatory functions; however, in vivo evidence for the existence of such structures has so far remained elusive. Here we report the generation and characterization of an antibody fragment (iMab) that recognizes i-motif structures with high selectivity and affinity, enabling the detection of i-motifs in the nuclei of human cells. We demonstrate that the in vivo formation of such structures is cell-cycle and pH dependent. Furthermore, we provide evidence that i-motif structures are formed in regulatory regions of the human genome, including promoters and telomeric regions. Our results support the notion that i-motif structures provide key regulatory roles in the genome.

Satellite Cells CD44 Positive Drive Muscle Regeneration in Osteoarthritis Patients

Science.gov (United States)

Scimeca, Manuel; Bonanno, Elena; Piccirilli, Eleonora; Baldi, Jacopo; Mauriello, Alessandro; Orlandi, Augusto; Tancredi, Virginia; Gasbarra, Elena; Tarantino, Umberto

2015-01-01

Age-related bone diseases, such as osteoarthritis and osteoporosis, are strongly associated with sarcopenia and muscle fiber atrophy. In this study, we analyzed muscle biopsies in order to demonstrate that, in osteoarthritis patients, both osteophytes formation and regenerative properties of muscle stem cells are related to the same factors. In particular, thanks to immunohistochemistry, transmission electron microscopy, and immunogold labeling we investigated the role of BMP-2 in muscle stem cells activity. In patients with osteoarthritis both immunohistochemistry and transmission electron microscopy allowed us to note a higher number of CD44 positive satellite muscle cells forming syncytium. Moreover, the perinuclear and cytoplasmic expression of BMP-2 assessed by in situ molecular characterization of satellite cells syncytia suggest a very strict correlation between BMP-2 expression and muscle regeneration capability. Summing up, the higher BMP-2 expression in osteoarthritic patients could explain the increased bone mineral density as well as decreased muscle atrophy in osteoarthrosic patients. In conclusion, our results suggest that the control of physiological BMP-2 balance between bone and muscle tissues may be considered as a potential pharmacological target in bone-muscle related pathology. PMID:26101529

Satellite Cells CD44 Positive Drive Muscle Regeneration in Osteoarthritis Patients

Directory of Open Access Journals (Sweden)

Manuel Scimeca

2015-01-01

Full Text Available Age-related bone diseases, such as osteoarthritis and osteoporosis, are strongly associated with sarcopenia and muscle fiber atrophy. In this study, we analyzed muscle biopsies in order to demonstrate that, in osteoarthritis patients, both osteophytes formation and regenerative properties of muscle stem cells are related to the same factors. In particular, thanks to immunohistochemistry, transmission electron microscopy, and immunogold labeling we investigated the role of BMP-2 in muscle stem cells activity. In patients with osteoarthritis both immunohistochemistry and transmission electron microscopy allowed us to note a higher number of CD44 positive satellite muscle cells forming syncytium. Moreover, the perinuclear and cytoplasmic expression of BMP-2 assessed by in situ molecular characterization of satellite cells syncytia suggest a very strict correlation between BMP-2 expression and muscle regeneration capability. Summing up, the higher BMP-2 expression in osteoarthritic patients could explain the increased bone mineral density as well as decreased muscle atrophy in osteoarthrosic patients. In conclusion, our results suggest that the control of physiological BMP-2 balance between bone and muscle tissues may be considered as a potential pharmacological target in bone-muscle related pathology.

[The frequency of sex chromatine occurring in cell nuclei of internal organs determined by the smear method (author's transl)].

Science.gov (United States)

Michailow, R

1975-09-05

The frequency of sex chromatine occurring in cell nuclei of twelve organs from 25 male and female corpses was determined using the smear method. It was found to be about 60% in the case of female, and about 6% in the case of male corpses.

The mechanism of total disintegration of heavy nuclei by fast hadrons and nuclei

International Nuclear Information System (INIS)

Strugalska-Gola, E.; Strugalski, Z.

1997-01-01

The mechanism of the total disintegration of atomic nuclei by fast hadrons and nuclei is considered. The passage of energetic hadrons through layers of intranuclear matter, accompanied by emission of fast nucleons with kinetic energies from about 20 up to about 500 MeV from definite local small regions in the nuclei around projectile courses in them, allows one to explain simply the occurrence of the total destruction of nuclei involved in the collisions. Light nuclei may be totally disintegrated by fast hadrons and nuclei; heavier nuclei may be totally disintegrated only in central collisions of nuclei with similar mass numbers

Nuclei of plants as a sink for flavanols.

Science.gov (United States)

Feucht, W; Polster, J

2001-01-01

Onion cepa (L.) and Tsuga canadensis (L.) Carr. were investigated histochemically on the association of flavanols to nuclei. The young roots of Onion cepa are totally devoid of flavanol structures. Therefore, the excised roots tips were directly incubated into different solutions of flavanols. After 3 h of incubation a flavanol binding on the nuclei was recognizable, as seen by a yellowish-brown tanning reaction. Still to ensure the presence of flavanols on the nuclei, subsequent staining with the p-dimethylaminocinnamaldehyde reagent (DMACA) resulted in an intense blue colouration. Tsuga canadensis has significant amounts of vacuolar flavanol deposits in all parts of the tree as indicated by the DMACA reagent. It is obvious that also the nuclei were associated strongly with flavanols which can be demonstrated particularly elegant in the cells of the seed wings by histochemical methods. However, the mode of flavanol release from the original deposits is not yet clear.

Evidence of heterogeneity within bovine satellite cells isolated from young and adult animals.

Science.gov (United States)

Li, J; Gonzalez, J M; Walker, D K; Hersom, M J; Ealy, A D; Johnson, S E

2011-06-01

Satellite cells are a heterogeneous population of myogenic precursors responsible for muscle growth and repair in mammals. The objectives of the experiment were to examine the growth rates and degree of heterogeneity within bovine satellite cells (BSC) isolated from young and adult animals. The BSC were harvested from the semimembranosus of young (4.3 ± 0.5 d) and adult (estimated 24 to 27 mo) cattle and cultured en masse. Young animal BSC re-enter the cell cycle sooner and reach maximal 5-ethynyl-2'-deoxyuridine (EdU) incorporation earlier (P animals after 3, 4, and 5 d in culture. These results indicate that BSC from young animals activate, proliferate, and differentiate sooner than isolates from adult animals. Lineage heterogeneity within BSC was examined using antibodies specific for Pax7 and Myf5, lineage markers of satellite cells, and myoblasts. Immunocytochemistry revealed the majority of Pax7-expressing BSC also express Myf5; a minor population (~5%) fails to exhibit Myf5 immunoreactivity. The percentage of Pax7:Myf5 BSC from young animals decreases sooner (P cell clones were established and analyzed after 10 d. Colonies segregated into 2 groups based upon population doubling time. Immunostaining of the slow-growing colonies (population doubling time ≥ 3 d) revealed that a portion exhibited asymmetric distribution of the lineage markers Pax7 and Myf5, similar to self-renewable mouse muscle stem cells. In summary, these results offer insight into the heterogeneity of BSC and provide evidence for subtle differences between rodent and bovine myogenic precursors.

DNA synthesis in HeLa cells and isolated nuclei after treatment with an inhibitor of spermidine synthesis, methyl glyoxal bis(guanylhydrazone).

Science.gov (United States)

Krokan, H; Eriksen, A

1977-02-01

Addition of methyl glyoxal bis(guanylhydrazone) to HeLa S3 suspension cultures resulted in increased putrescine levels and decreased spermidine and spermine levels preceding a drop in incorporation of [3H]thymidine, [3H]uridine and [14C]leucine into macromolecules. When putrescine, spermidine, spermine or cadaverine was added simultaneously with methyl glyoxal bis(guanylhydrazone), the drug had no detectable effect on the synthesis of macromolecules. In nuclei isolated from cells treated with methyl glyoxal bis(guanylhydrazone) the reduction in the rate of DNA synthesis was equal to the reduction of [3H]thymidine incorporation in the corresponding whole cells. The capability of the nuclei to synthesize DNA could not be restored by adding spermidine or spermine to the system in vitro. The rate of DNA chain elongation was only reduced slightly by methyl glyoxal bis(guanylhydrazone) indicating that decreased levels of spermidine and spermine lead to a decrease in the number of replication units active in DNA synthesis within each cell.

Frequency of M-cadherin-stained satellite cells declines in human muscles during aging

Czech Academy of Sciences Publication Activity Database

Sajko, Š.; Kubínová, Lucie; Cvetko, E.; Kreft, M.; Wernig, A.; Eržen, I.

2004-01-01

Roč. 52, č. 2 (2004), s. 179-185 ISSN 0022-1554 Grant - others:European programme(XE) QLKG-1999-02034 Institutional research plan: CEZ:AV0Z5011922 Keywords : satellite cells * skeletal muscle * stereology Subject RIV: EA - Cell Biology Impact factor: 2.513, year: 2004

[Some morphometric parameters of nucleoli and nuclei in invasive ductal breast carcinomas in women].

Science.gov (United States)

Karpinska-Kaczmarczyk, Katarzyna

2009-01-01

The purpose of this study was to correlate seven morphometric parameters of nucleoli and nuclei of invasive ductal cancer cells with some clinico-pathological factors such as age, tumor size, axillary lymph node status, MIB-1 proliferation index, and estrogen receptor expression in tumor cells. Methyl green-pyronin Y (MG-PY) was used for simultaneous staining of nuclei and nucleoli in histological sections of 150 invasive ductal breast carcinomas. Next, morphometric parameters of nucleoli and nuclei of tumor cells were measured with computerized image analysis. Nuclear area and number of nucleoli in breast tumor cells were greater in younger axillary node-negative patients. The number of nucleoli and nucleolar shape polymorphism were reduced in tumors measuring 20 mm or less or with lower histological grade. Nuclear area, nucleolar number, and nucleolar polymorphism in carcinomas with low proliferation index and estrogen receptor expression were smaller than in carcinomas with high proliferation index and no estrogen receptor expression. Nucleolar area in primary tumors without axillary node involvement was greater than in tumors with more than three axillary nodes positive. MG-PY selectively and simultaneously stains nucleoli and nuclei of tumor cells enabling standardized and reproducible examination of these structures with computerized image analysis. Univariate statistical analysis disclosed that some morphometric parameters of nucleoli and nuclei of tumor cells correlated with several established clinico-pathological prognostic factors. Therefore, the prognostic significance of these parameters should be studied in a larger group of patients with invasive ductal breast carcinomas.

Exotic nuclei

International Nuclear Information System (INIS)

Villari, A.C.C.

1990-01-01

The actual tendencies to study exotic nuclei; applications of exotic nuclei beams in material study and medicine; recent results obtained by GANIL and Berkeley Laboratories of measurements of binding energy and radii of light nuclei; the future experiences to be carry out in several international laboratories and; proposal of studies in Brazil using Pelletron-USP accelerator and the LINAC superconductor accelerator, in construction in the same laboratory, are presented. (M.C.K.)

TIME COURSE ALTERATIONS OF SATELLITE CELL EVENTS IN RESPONSE TO LIGHT MODERATE ENDURANCE TRAINING IN WHITE GASTROCNEMIUS MUSCLE OF THE RAT

Directory of Open Access Journals (Sweden)

Zong-Yan Cai

2012-01-01

Full Text Available This study investigated satellite cells and their related molecular events adapted to light moderate endurance training in the white gastrocnemius muscle of the rat. The white gastrocnemius muscle of male Sprague-Dawley rats that had been trained for 4 weeks and 8 weeks, with control rats being analysed alongside them, was selected for analysis (n=3 per group. The training protocol consisted of treadmill running at 20 m · min-1 for 30 min on a 0% grade, for 3 days · week-1. Immunohistochemical staining coupled with image analysis was used for quantification. To provide deeper insight into the cell layer, 40 sections per rat, corresponding to 120 values per group, were obtained as a mean value for statistical comparison. The results indicated that at week 4, training effects increased the vascular endothelial growth factor (VEGF content and c-met positive satellite cell numbers. At week 8, the training effect was attenuated for VEGF and c-met satellite cell numbers, but it increased in the muscle fibre area. Additionally, c-met positive satellite cell numbers correlated with VEGF content (r = 0.79, p<0.05. In conclusion, this study suggests that light moderate endurance training could stimulate satellite cell activation that might be related to VEGF signalling. Additionally, the satellite cells activated by moderate endurance training might contribute to slight growth in myocytes.

Adapted physical exercise enhances activation and differentiation potential of satellite cells in the skeletal muscle of old mice.

Science.gov (United States)

Cisterna, Barbara; Giagnacovo, Marzia; Costanzo, Manuela; Fattoretti, Patrizia; Zancanaro, Carlo; Pellicciari, Carlo; Malatesta, Manuela

2016-05-01

During ageing, a progressive loss of skeletal muscle mass and a decrease in muscle strength and endurance take place, in the condition termed sarcopenia. The mechanisms of sarcopenia are complex and still unclear; however, it is known that muscle atrophy is associated with a decline in the number and/or efficiency of satellite cells, the main contributors to muscle regeneration. Physical exercise proved beneficial in sarcopenia; however, knowledge of the effect of adapted physical exercise on the myogenic properties of satellite cells in aged muscles is limited. In this study the amount and activation state of satellite cells as well as their proliferation and differentiation potential were assessed in situ by morphology, morphometry and immunocytochemistry at light and transmission electron microscopy on 28-month-old mice submitted to adapted aerobic physical exercise on a treadmill. Sedentary age-matched mice served as controls, and sedentary adult mice were used as a reference for an unperturbed control at an age when the capability of muscle regeneration is still high. The effect of physical exercise in aged muscles was further analysed by comparing the myogenic potential of satellite cells isolated from old running and old sedentary mice using an in vitro system that allows observation of the differentiation process under controlled experimental conditions. The results of this ex vivo and in vitro study demonstrated that adapted physical exercise increases the number and activation of satellite cells as well as their capability to differentiate into structurally and functionally correct myotubes (even though the age-related impairment in myotube formation is not fully reversed): this evidence further supports adapted physical exercise as a powerful, non-pharmacological approach to counteract sarcopenia and the age-related deterioration of satellite cell capabilities even at very advanced age. © 2016 Anatomical Society.

Nuclei transmutation by collisions with fast hadrons and nuclei

International Nuclear Information System (INIS)

Strugalski, Z.; Strugalska-Gola, E.; Drzymala, A.

1998-01-01

Atomic nuclei change their mass- and charge-numbers if bombarded by fast hadrons and nuclei; the transmutation appears as a complicated process. It proceeds in a definite way - through a few stages or phases. Adequate identification of the nucleons and light nuclear fragments emitted and evaporated in a hadron-nucleus or nucleus-nucleus collisions and in the collision-induced intranuclear reactions allows one to estimate quantitatively the nuclei transmutations in the various stages (phases) of the process

Pair correlations in nuclei

International Nuclear Information System (INIS)

Shimizu, Yoshifumi

2009-01-01

Except for the closed shell nuclei, almost all nuclei are in the superconducting state at their ground states. This well-known pair correlation in nuclei causes various interesting phenomena. It is especially to be noted that the pair correlation becomes weak in the excited states of nuclei with high angular momentum, which leads to the pair phase transition to the normal state in the high spin limit. On the other hand, the pair correlation becomes stronger in the nuclei with lower nucleon density than in those with normal density. In the region of neutron halo or skin state of unstable nuclei, this phenomenon is expected to be further enhanced to be observed compared to the ground state of stable nuclei. An overview of those interesting aspects caused via the pair correlation is presented here in the sections titled 'pair correlations in ground states', pair correlations in high spin states' and 'pair correlations in unstable nuclei' focusing on the high spin state. (S. Funahashi)

Modulation of Higher Order Chromatin Conformation in Mammalian Cell Nuclei Can Be Mediated by Polyamines and Divalent Cations.

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Ashwat Visvanathan

Full Text Available The organisation of the large volume of mammalian genomic DNA within cell nuclei requires mechanisms to regulate chromatin compaction involving the reversible formation of higher order structures. The compaction state of chromatin varies between interphase and mitosis and is also subject to rapid and reversible change upon ATP depletion/repletion. In this study we have investigated mechanisms that may be involved in promoting the hyper-condensation of chromatin when ATP levels are depleted by treating cells with sodium azide and 2-deoxyglucose. Chromatin conformation was analysed in both live and permeabilised HeLa cells using FLIM-FRET, high resolution fluorescence microscopy and by electron spectroscopic imaging microscopy. We show that chromatin compaction following ATP depletion is not caused by loss of transcription activity and that it can occur at a similar level in both interphase and mitotic cells. Analysis of both live and permeabilised HeLa cells shows that chromatin conformation within nuclei is strongly influenced by the levels of divalent cations, including calcium and magnesium. While ATP depletion results in an increase in the level of unbound calcium, chromatin condensation still occurs even in the presence of a calcium chelator. Chromatin compaction is shown to be strongly affected by small changes in the levels of polyamines, including spermine and spermidine. The data are consistent with a model in which the increased intracellular pool of polyamines and divalent cations, resulting from depletion of ATP, bind to DNA and contribute to the large scale hyper-compaction of chromatin by a charge neutralisation mechanism.

Ranked retrieval of segmented nuclei for objective assessment of cancer gene repositioning

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Cukierski William J

2012-09-01

Full Text Available Abstract Background Correct segmentation is critical to many applications within automated microscopy image analysis. Despite the availability of advanced segmentation algorithms, variations in cell morphology, sample preparation, and acquisition settings often lead to segmentation errors. This manuscript introduces a ranked-retrieval approach using logistic regression to automate selection of accurately segmented nuclei from a set of candidate segmentations. The methodology is validated on an application of spatial gene repositioning in breast cancer cell nuclei. Gene repositioning is analyzed in patient tissue sections by labeling sequences with fluorescence in situ hybridization (FISH, followed by measurement of the relative position of each gene from the nuclear center to the nuclear periphery. This technique requires hundreds of well-segmented nuclei per sample to achieve statistical significance. Although the tissue samples in this study contain a surplus of available nuclei, automatic identification of the well-segmented subset remains a challenging task. Results Logistic regression was applied to features extracted from candidate segmented nuclei, including nuclear shape, texture, context, and gene copy number, in order to rank objects according to the likelihood of being an accurately segmented nucleus. The method was demonstrated on a tissue microarray dataset of 43 breast cancer patients, comprising approximately 40,000 imaged nuclei in which the HES5 and FRA2 genes were labeled with FISH probes. Three trained reviewers independently classified nuclei into three classes of segmentation accuracy. In man vs. machine studies, the automated method outperformed the inter-observer agreement between reviewers, as measured by area under the receiver operating characteristic (ROC curve. Robustness of gene position measurements to boundary inaccuracies was demonstrated by comparing 1086 manually and automatically segmented nuclei. Pearson

Local NSAID infusion inhibits satellite cell proliferation in human skeletal muscle after eccentric exercise

DEFF Research Database (Denmark)

Mikkelsen, U R; Langberg, H; Helmark, I C

2009-01-01

Despite the widespread consumption of nonsteroidal anti-inflammatory drugs (NSAIDs), the influence of these drugs on muscle satellite cells is not fully understood. The aim of the present study was to investigate the effect of a local NSAID infusion on satellite cells after unaccustomed eccentric...... exercise in vivo in human skeletal muscle. Eight young healthy males performed 200 maximal eccentric contractions with each leg. An NSAID was infused via a microdialysis catheter into the vastus lateralis muscle of one leg (NSAID leg) before, during, and for 4.5 h after exercise, with the other leg working...... cells (CD68(+) or CD16(+) cells) was not significantly increased in either of the legs 8 days after exercise and was unaffected by the NSAID. The main finding in the present study was that the NSAID infusion for 7.5 h during the exercise day suppressed the exercise-induced increase in the number...

Integrity of chromatin and replicating DNA in nuclei released from fission yeast by semi-automated grinding in liquid nitrogen

Science.gov (United States)

2011-01-01

Background Studies of nuclear function in many organisms, especially those with tough cell walls, are limited by lack of availability of simple, economical methods for large-scale preparation of clean, undamaged nuclei. Findings Here we present a useful method for nuclear isolation from the important model organism, the fission yeast, Schizosaccharomyces pombe. To preserve in vivo molecular configurations, we flash-froze the yeast cells in liquid nitrogen. Then we broke their tough cell walls, without damaging their nuclei, by grinding in a precision-controlled motorized mortar-and-pestle apparatus. The cryo-ground cells were resuspended and thawed in a buffer designed to preserve nuclear morphology, and the nuclei were enriched by differential centrifugation. The washed nuclei were free from contaminating nucleases and have proven well-suited as starting material for genome-wide chromatin analysis and for preparation of fragile DNA replication intermediates. Conclusions We have developed a simple, reproducible, economical procedure for large-scale preparation of endogenous-nuclease-free, morphologically intact nuclei from fission yeast. With appropriate modifications, this procedure may well prove useful for isolation of nuclei from other organisms with, or without, tough cell walls. PMID:22088094

Integrity of chromatin and replicating DNA in nuclei released from fission yeast by semi-automated grinding in liquid nitrogen.

Science.gov (United States)

Givens, Robert M; Mesner, Larry D; Hamlin, Joyce L; Buck, Michael J; Huberman, Joel A

2011-11-16

Studies of nuclear function in many organisms, especially those with tough cell walls, are limited by lack of availability of simple, economical methods for large-scale preparation of clean, undamaged nuclei. Here we present a useful method for nuclear isolation from the important model organism, the fission yeast, Schizosaccharomyces pombe. To preserve in vivo molecular configurations, we flash-froze the yeast cells in liquid nitrogen. Then we broke their tough cell walls, without damaging their nuclei, by grinding in a precision-controlled motorized mortar-and-pestle apparatus. The cryo-ground cells were resuspended and thawed in a buffer designed to preserve nuclear morphology, and the nuclei were enriched by differential centrifugation. The washed nuclei were free from contaminating nucleases and have proven well-suited as starting material for genome-wide chromatin analysis and for preparation of fragile DNA replication intermediates. We have developed a simple, reproducible, economical procedure for large-scale preparation of endogenous-nuclease-free, morphologically intact nuclei from fission yeast. With appropriate modifications, this procedure may well prove useful for isolation of nuclei from other organisms with, or without, tough cell walls.

Integrity of chromatin and replicating DNA in nuclei released from fission yeast by semi-automated grinding in liquid nitrogen

Directory of Open Access Journals (Sweden)

Givens Robert M

2011-11-01

Full Text Available Abstract Background Studies of nuclear function in many organisms, especially those with tough cell walls, are limited by lack of availability of simple, economical methods for large-scale preparation of clean, undamaged nuclei. Findings Here we present a useful method for nuclear isolation from the important model organism, the fission yeast, Schizosaccharomyces pombe. To preserve in vivo molecular configurations, we flash-froze the yeast cells in liquid nitrogen. Then we broke their tough cell walls, without damaging their nuclei, by grinding in a precision-controlled motorized mortar-and-pestle apparatus. The cryo-ground cells were resuspended and thawed in a buffer designed to preserve nuclear morphology, and the nuclei were enriched by differential centrifugation. The washed nuclei were free from contaminating nucleases and have proven well-suited as starting material for genome-wide chromatin analysis and for preparation of fragile DNA replication intermediates. Conclusions We have developed a simple, reproducible, economical procedure for large-scale preparation of endogenous-nuclease-free, morphologically intact nuclei from fission yeast. With appropriate modifications, this procedure may well prove useful for isolation of nuclei from other organisms with, or without, tough cell walls.

From heavy nuclei to super-heavy nuclei

International Nuclear Information System (INIS)

Theisen, Ch.

2003-01-01

The existence of super-heavy nuclei has been predicted nearly fifty years ago. Due to the strong coulomb repulsion, the stabilisation of these nuclei is possible only through shell effects. The reasons for this fragile stability, as well as the theoretical predictions concerning the position of the island of stability are presented in the first part of this lecture. In the second part, experiments and experimental techniques which have been used to synthesize or search for super-heavy elements are described. Spectroscopic studies performed in very heavy elements are presented in the following section. We close this lecture with techniques that are currently being developed in order to reach the superheavy island and to study the structure of very-heavy nuclei. (author)

Muscle atrophy reversed by growth factor activation of satellite cells in a mouse muscle atrophy model.

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Simon Hauerslev

Full Text Available Muscular dystrophies comprise a large group of inherited disorders that lead to progressive muscle wasting. We wanted to investigate if targeting satellite cells can enhance muscle regeneration and thus increase muscle mass. We treated mice with hepatocyte growth factor and leukemia inhibitory factor under three conditions: normoxia, hypoxia and during myostatin deficiency. We found that hepatocyte growth factor treatment led to activation of the Akt/mTOR/p70S6K protein synthesis pathway, up-regulation of the myognic transcription factors MyoD and myogenin, and subsequently the negative growth control factor, myostatin and atrophy markers MAFbx and MuRF1. Hypoxia-induced atrophy was partially restored by hepatocyte growth factor combined with leukemia inhibitory factor treatment. Dividing satellite cells were three-fold increased in the treatment group compared to control. Finally, we demonstrated that myostatin regulates satellite cell activation and myogenesis in vivo following treatment, consistent with previous findings in vitro. Our results suggest, not only a novel in vivo pharmacological treatment directed specifically at activating the satellite cells, but also a myostatin dependent mechanism that may contribute to the progressive muscle wasting seen in severely affected patients with muscular dystrophy and significant on-going regeneration. This treatment could potentially be applied to many conditions that feature muscle wasting to increase muscle bulk and strength.

Studies of exotic nuclei

International Nuclear Information System (INIS)

Angelique, J.C.; Orr, N.A.

1997-01-01

The study of the nuclei far off stability valley is of much interest for testing the nuclear models established for the stable nuclei but also for astrophysics to understand the nucleosynthesis. Experiments aim to measure the mass and lifetime, to build the decay schemes and also to study the structure and the properties of these nuclei. The radioactive beam group focused its research on light neutron-rich nuclei having a halo neutron structure. Mass measurements in N ∼ Z nuclei namely in A ∼ 60-80 proton-rich nuclei, important for understanding the rp process, are mentioned, as well as in nuclei in the 100 Sn region. In the newly obtained 26 O and 28 O nuclei the lifetimes, the probabilities of emission of one for more neutrons were determined. The data analysis has permitted to determine also for the first time the lifetimes of 27,29 F and 30 Ne. Studies of nuclei in the 100 Sn region, near the proton drip line in the ground and isomeric states are now under way. The spectroscopy (energy levels, gamma emissions, etc.) of the neutron-rich nuclei produced by the 36 S fragmentation has been carried out in 31 Ne, 17 B and 29 F. Studies by Coulomb excitation of the 2 + excited states and associated probability B (E2) in O, Ne, Ni and Zn are now analysed

Nuclei pulposi formation from the embryonic notochord occurs normally in GDF-5-deficient mice.

Science.gov (United States)

Maier, Jennifer A; Harfe, Brian D

2011-11-15

The transition of the mouse embryonic notochord into nuclei pulposi was determined ("fate mapped") in vivo in growth and differentiating factor-5 (GDF-5)-null mice using the Shhcre and R26R alleles. To determine whether abnormal nuclei pulposi formation from the embryonic notochord was responsible for defects present in adult nuclei pulposi of Gdf-5-null mice. The development, maintenance, and degeneration of the intervertebral disc are not understood. Previously, we demonstrated that all cells in the adult nucleus pulposus of normal mice are derived from the embryonic notochord. Gdf-5-null mice have been reported to contain intervertebral discs in which the nucleus pulposus is abnormal. It is currently unclear if disc defects in Gdf-5-null mice arise during the formation of nuclei pulposi from the notochord during embryogenesis or result from progressive postnatal degeneration of nuclei pulposi. Gdf-5 messenger RNA expression was examined in the discs of wild-type embryos by RNA in situ hybridization to determine when and where this gene was expressed. To examine nucleus pulposus formation in Gdf-5-null mice, intervertebral discs in which embryonic notochord cells were marked were analyzed in newborn and 24-week-old mice. Our Gdf-5 messenger RNA in situ experiments determined that this gene is localized to the annulus fibrosus and not the nucleus pulposus in mouse embryos. Notochord fate-mapping experiments revealed that notochord cells in Gdf-5-null mice correctly form nuclei pulposi. Our data suggest that the defects reported in the nucleus pulposus of adult Gdf-5-null mice do not result from abnormal patterning of the embryonic notochord. The use of mouse alleles to mark cells that produce all cell types that reside in the adult nucleus pulposus will allow for a detailed examination of disc formation in other mouse mutants that have been reported to contain disc defects.

Population transfer HMQC for half-integer quadrupolar nuclei

International Nuclear Information System (INIS)

Wang, Qiang; Xu, Jun; Feng, Ningdong; Deng, Feng; Li, Yixuan; Trébosc, Julien; Lafon, Olivier; Hu, Bingwen; Chen, Qun; Amoureux, Jean-Paul

2015-01-01

This work presents a detailed analysis of a recently proposed nuclear magnetic resonance method [Wang et al., Chem. Commun. 49(59), 6653-6655 (2013)] for accelerating heteronuclear coherence transfers involving half-integer spin quadrupolar nuclei by manipulating their satellite transitions. This method, called Population Transfer Heteronuclear Multiple Quantum Correlation (PT-HMQC), is investigated in details by combining theoretical analyses, numerical simulations, and experimental investigations. We find that compared to instant inversion or instant saturation, continuous saturation is the most practical strategy to accelerate coherence transfers on half-integer quadrupolar nuclei. We further demonstrate that this strategy is efficient to enhance the sensitivity of J-mediated heteronuclear correlation experiments between two half-integer quadrupolar isotopes (e.g., 27 Al- 17 O). In this case, the build-up is strongly affected by relaxation for small T 2 ′ and J coupling values, and shortening the mixing time makes a huge signal enhancement. Moreover, this concept of population transfer can also be applied to dipolar-mediated HMQC experiments. Indeed, on the AlPO 4 -14 sample, one still observes experimentally a 2-fold shortening of the optimum mixing time albeit with no significant signal gain in the 31 P-( 27 Al) experiments

Proinflammatory cytokine tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) suppresses satellite cell self-renewal through inversely modulating Notch and NF-κB signaling pathways.

Science.gov (United States)

Ogura, Yuji; Mishra, Vivek; Hindi, Sajedah M; Kuang, Shihuan; Kumar, Ashok

2013-12-06

Satellite cell self-renewal is an essential process to maintaining the robustness of skeletal muscle regenerative capacity. However, extrinsic factors that regulate self-renewal of satellite cells are not well understood. Here, we demonstrate that TWEAK cytokine reduces the proportion of Pax7(+)/MyoD(-) cells (an index of self-renewal) on myofiber explants and represses multiple components of Notch signaling in satellite cell cultures. The number of Pax7(+) cells is significantly increased in skeletal muscle of TWEAK knock-out (KO) mice compared with wild-type in response to injury. Furthermore, Notch signaling is significantly elevated in cultured satellite cells and in regenerating myofibers of TWEAK-KO mice. Forced activation of Notch signaling through overexpression of the Notch1 intracellular domain (N1ICD) rescued the TWEAK-mediated inhibition of satellite cell self-renewal. TWEAK also activates the NF-κB transcription factor in satellite cells and inhibition of NF-κB significantly improved the number of Pax7(+) cells in TWEAK-treated cultures. Furthermore, our results demonstrate that a reciprocal interaction between NF-κB and Notch signaling governs the inhibitory effect of TWEAK on satellite cell self-renewal. Collectively, our study demonstrates that TWEAK suppresses satellite cell self-renewal through activating NF-κB and repressing Notch signaling.

Reduced satellite cell density and myogenesis in Wagyu compared with Angus cattle as a possible explanation of its high marbling.

Science.gov (United States)

Fu, X; Yang, Q; Wang, B; Zhao, J; Zhu, M; Parish, S M; Du, M

2018-05-01

Mechanisms responsible for excellent marbling in Japanese black cattle, Wagyu, remain to be established. Because both muscle cells and intramuscular adipocytes are developed from mesenchymal progenitor cells during early muscle development, we hypothesized that intramuscular progenitor cells in Wagyu cattle have attenuated myogenic capacity in favor of adipogenesis, leading to high marbling but reduced muscle growth. Biceps femoris muscle biopsy samples were obtained from both Angus (n=3) and Wagyu (n=3) cattle at 12 months of age. Compared with Angus, the density of satellite cells was much lower in Wagyu muscle (by 45.8±10%, PAngus cattle. Because satellite cells are derived from fetal myogenic cells, the reduction in satellite cell density together with lower muscle fiber formation suggests that myogenesis was attenuated during early muscle development in Wagyu cattle. Given the shared pool of mesenchymal progenitor cells, the attenuated myogenesis likely shifts progenitor cells to adipogenesis during early development, which may contribute to high intramuscular adipocyte formation in Wagyu cattle.

Association of pKi-67 with satellite DNA of the human genome in early G1 cells.

Science.gov (United States)

Bridger, J M; Kill, I R; Lichter, P

1998-01-01

pKi-67 is a nucleolar antigen that provides a specific marker for proliferating cells. It has been shown previously that pKi-67's distribution varies in a cell cycle-dependent manner: it coats all chromosomes during mitosis, accumulates in nuclear foci during G1 phase (type I distribution) and localizes within nucleoli in late G1 S and G2 phase (type II distribution). Although no function has as yet been ascribed to pKi-67, it has been found associated with centromeres in G1. In the present study the distribution pattern of pKi-67 during G1 in human dermal fibroblasts (HDFs) was analysed in more detail. Synchronization experiments show that in very early G1 cells pKi-67 coincides with virtually all satellite regions analysed, i.e. with centromeric (alpha-satellite), telomeric (minisatellite) and heterochromatic blocks (satellite III) on chromosomes 1 and Y (type Ia distribution). In contrast, later in the G1 phase, a smaller fraction of satellite DNA regions are found collocalized with pKi-67 foci (type Ib distribution). When all pKi-67 becomes localized within nucleoli, even fewer satellite regions remain associated with the pKi-67 staining. However, all centromeric and short arm regions of the acrocentric chromosomes, which are in very close proximity to or even contain the rRNA genes, are collocalized with anti-pKi-67 staining throughout the remaining interphase of the cell cycle. Thus, our data demonstrate that during post-mitotic reformation and nucleogenesis there is a progressive decline in the fraction of specific satellite regions of DNA that remain associated with pKi-67. This may be relevant to nucleolar reformation following mitosis.

IGF-1 colocalizes with muscle satellite cells following acute exercise in humans.

Science.gov (United States)

Grubb, Amanda; Joanisse, Sophie; Moore, Daniel R; Bellamy, Leeann M; Mitchell, Cameron J; Phillips, Stuart M; Parise, Gianni

2014-04-01

Insulin-like growth factor-1 (IGF-1) regulates stem cell proliferation and differentiation in vitro. The aim of this study was to quantify the change in satellite cell (SC) specific IGF-1 colocalization following exercise. We observed a significant increase (p IGF-1 colocalization from baseline to 72 h after a bout of resistance exercise. This strongly supports a role for IGF-1 in human SC function following exercise.

The asymptotic hadron spectrum, anti-nuclei, hyper-nuclei and quark phase

International Nuclear Information System (INIS)

Glendenning, N.K.

1978-01-01

The only hope of determining the hadronic spectrum in the high mass region is through a study of matter produced in very high energy nuclear collisions. Along the way, exotic nuclei, i.e., anti-nuclei and hyper-nuclei may be produced in appreciable numbers, and the detection of a quark phase may be possible. (orig.) [de

Solar array experiments on the SPHINX satellite. [Space Plasma High voltage INteraction eXperiment satellite

Science.gov (United States)

Stevens, N. J.

1974-01-01

The Space Plasma, High Voltage Interaction Experiment (SPHINX) is the name given to an auxiliary payload satellite scheduled to be launched in January 1974. The principal experiments carried on this satellite are specifically designed to obtain the engineering data on the interaction of high voltage systems with the space plasma. The classes of experiments are solar array segments, insulators, insulators with pin holes and conductors. The satellite is also carrying experiments to obtain flight data on three new solar array configurations: the edge illuminated-multijunction cells, the teflon encased cells, and the violet cells.

Circularly Polarized Transparent Microstrip Patch Reflectarray Integrated with Solar Cell for Satellite Applications

OpenAIRE

Zainud-Deen, S. H.; El-Shalaby, N. A.; Gaber, S. M.; Malhat, H. A.

2016-01-01

Circularly polarized (CP) transparent microstrip reflectarray antenna is integrated with solar cell for small satellite applications at 10 GHz. The reflectarray unit cell consists of a perfect electric conductor (PEC) square patch printed on an optically transparent substrate with the PEC ground plane. A comparison between using transparent conducting polymers and using the PEC in unit-cell construction has been introduced. The waveguide simulator is used to calculate the required compensatio...

Level structures in Yb nuclei far from stable nuclei

International Nuclear Information System (INIS)

Hashizume, Akira

1982-01-01

Applying n-γ, γ-γ coincidence techniques, the excited levels in 158 Yb and in 157 Yb nuclei were studied. Stress is placed ona neutron detection technique to assign (HI,xn) reactions which produce the nuclei far from β stability line. (author)

Differential satellite cell density of type I and II fibres with lifelong endurance running in old men

DEFF Research Database (Denmark)

Mackey, Abigail; Karlsen, A; Couppé, C

2014-01-01

AIM: To investigate the influence of lifelong endurance running on the satellite cell pool of type I and type II fibres in healthy human skeletal muscle. METHODS: Muscle biopsies were collected from 15 healthy old trained men (O-Tr) who had been running 43 ± 16 (mean ± SD) kilometres a week for 28...... ± 9 years. Twelve age-matched untrained men (O-Un) and a group of young trained and young untrained men were recruited for comparison. Frozen sections were immunohistochemically stained for Pax7, type I myosin and laminin, from which fibre area, the number of satellite cells, and the relationship......-Un. A strong positive relationship between fibre size and satellite cell content was detected in trained individuals. In line with a history of myofibre repair, a greater number of fibres with centrally located myonuclei were detected in O-Tr. CONCLUSION: Lifelong endurance training (i) does not deplete...

Using satellite-based measurements to explore spatiotemporal scales and variability of drivers of new particle formation

Science.gov (United States)

New particle formation (NPF) can potentially alter regional climate by increasing aerosol particle (hereafter particle) number concentrations and ultimately cloud condensation nuclei. The large scales on which NPF is manifest indicate potential to use satellite-based (inherently ...

Optimized Fast-FISH with a-satellite probes: acceleration by microwave activation

Directory of Open Access Journals (Sweden)

Durm M.

1997-01-01

Full Text Available It has been shown for several DNA probes that the recently introduced Fast-FISH (fluorescence in situ hybridization technique is well suited for quantitative microscopy. For highly repetitive DNA probes the hybridization (renaturation time and the number of subsequent washing steps were reduced considerably by omitting denaturing chemical agents (e.g., formamide. The appropriate hybridization temperature and time allow a clear discrimination between major and minor binding sites by quantitative fluorescence microscopy. The well-defined physical conditions for hybridization permit automatization of the procedure, e.g., by a programmable thermal cycler. Here, we present optimized conditions for a commercially available X-specific a-satellite probe. Highly fluorescent major binding sites were obtained for 74oC hybridization temperature and 60 min hybridization time. They were clearly discriminated from some low fluorescent minor binding sites on metaphase chromosomes as well as in interphase cell nuclei. On average, a total of 3.43 ± 1.59 binding sites were measured in metaphase spreads, and 2.69 ± 1.00 in interphase nuclei. Microwave activation for denaturation and hybridization was tested to accelerate the procedure. The slides with the target material and the hybridization buffer were placed in a standard microwave oven. After denaturation for 20 s at 900 W, hybridization was performed for 4 min at 90 W. The suitability of a microwave oven for Fast-FISH was confirmed by the application to a chromosome 1-specific a-satellite probe. In this case, denaturation was performed at 630 W for 60 s and hybridization at 90 W for 5 min. In all cases, the results were analyzed quantitatively and compared to the results obtained by Fast-FISH. The major binding sites were clearly discriminated by their brightness

Solar satellites

Energy Technology Data Exchange (ETDEWEB)

Poher, C.

1982-01-01

A reference system design, projected costs, and the functional concepts of a satellite solar power system (SSPS) for converting sunlight falling on solar panels of a satellite in GEO to a multi-GW beam which could be received by a rectenna on earth are outlined. Electricity transmission by microwaves has been demonstrated, and a reference design system for supplying 5 GW dc to earth was devised. The system will use either monocrystalline Si or concentrator GaAs solar cells for energy collection in GEO. Development is still needed to improve the lifespan of the cells. Currently, the cell performance degrades 50 percent in efficiency after 7-8 yr in space. Each SSPS satellite would weigh either 34,000 tons (Si) or 51,000 tons (GaAs), thereby requiring the fabrication of a heavy lift launch vehicle or a single-stage-to-orbit transport in order to minimize launch costs. Costs for the solar panels have been estimated at $500/kW using the GaAs technology, with transport costs for materials to GEO being $40/kg.

Solar satellites

Science.gov (United States)

Poher, C.

A reference system design, projected costs, and the functional concepts of a satellite solar power system (SSPS) for converting sunlight falling on solar panels of a satellite in GEO to a multi-GW beam which could be received by a rectenna on earth are outlined. Electricity transmission by microwaves has been demonstrated, and a reference design system for supplying 5 GW dc to earth was devised. The system will use either monocrystalline Si or concentrator GaAs solar cells for energy collection in GEO. Development is still needed to improve the lifespan of the cells. Currently, the cell performance degrades 50 percent in efficiency after 7-8 yr in space. Each SSPS satellite would weigh either 34,000 tons (Si) or 51,000 tons (GaAs), thereby requiring the fabrication of a heavy lift launch vehicle or a single-stage-to-orbit transport in order to minimize launch costs. Costs for the solar panels have been estimated at $500/kW using the GaAs technology, with transport costs for materials to GEO being $40/kg.

Robust nuclei segmentation in cyto-histopathological images using statistical level set approach with topology preserving constraint

Science.gov (United States)

Taheri, Shaghayegh; Fevens, Thomas; Bui, Tien D.

2017-02-01

Computerized assessments for diagnosis or malignancy grading of cyto-histopathological specimens have drawn increased attention in the field of digital pathology. Automatic segmentation of cell nuclei is a fundamental step in such automated systems. Despite considerable research, nuclei segmentation is still a challenging task due noise, nonuniform illumination, and most importantly, in 2D projection images, overlapping and touching nuclei. In most published approaches, nuclei refinement is a post-processing step after segmentation, which usually refers to the task of detaching the aggregated nuclei or merging the over-segmented nuclei. In this work, we present a novel segmentation technique which effectively addresses the problem of individually segmenting touching or overlapping cell nuclei during the segmentation process. The proposed framework is a region-based segmentation method, which consists of three major modules: i) the image is passed through a color deconvolution step to extract the desired stains; ii) then the generalized fast radial symmetry transform is applied to the image followed by non-maxima suppression to specify the initial seed points for nuclei, and their corresponding GFRS ellipses which are interpreted as the initial nuclei borders for segmentation; iii) finally, these nuclei border initial curves are evolved through the use of a statistical level-set approach along with topology preserving criteria for segmentation and separation of nuclei at the same time. The proposed method is evaluated using Hematoxylin and Eosin, and fluorescent stained images, performing qualitative and quantitative analysis, showing that the method outperforms thresholding and watershed segmentation approaches.

Regulation of myogenesis and skeletal muscle regeneration: effects of oxygen levels on satellite cell activity.

Science.gov (United States)

Chaillou, Thomas; Lanner, Johanna T

2016-12-01

Reduced oxygen (O 2 ) levels (hypoxia) are present during embryogenesis and exposure to altitude and in pathologic conditions. During embryogenesis, myogenic progenitor cells reside in a hypoxic microenvironment, which may regulate their activity. Satellite cells are myogenic progenitor cells localized in a local environment, suggesting that the O 2 level could affect their activity during muscle regeneration. In this review, we present the idea that O 2 levels regulate myogenesis and muscle regeneration, we elucidate the molecular mechanisms underlying myogenesis and muscle regeneration in hypoxia and depict therapeutic strategies using changes in O 2 levels to promote muscle regeneration. Severe hypoxia (≤1% O 2 ) appears detrimental for myogenic differentiation in vitro, whereas a 3-6% O 2 level could promote myogenesis. Hypoxia impairs the regenerative capacity of injured muscles. Although it remains to be explored, hypoxia may contribute to the muscle damage observed in patients with pathologies associated with hypoxia (chronic obstructive pulmonary disease, and peripheral arterial disease). Hypoxia affects satellite cell activity and myogenesis through mechanisms dependent and independent of hypoxia-inducible factor-1α. Finally, hyperbaric oxygen therapy and transplantation of hypoxia-conditioned myoblasts are beneficial procedures to enhance muscle regeneration in animals. These therapies may be clinically relevant to treatment of patients with severe muscle damage.-Chaillou, T. Lanner, J. T. Regulation of myogenesis and skeletal muscle regeneration: effects of oxygen levels on satellite cell activity. © FASEB.

Satellite cell response to erythropoietin treatment and endurance training in healthy young men

DEFF Research Database (Denmark)

Hoedt, Andrea; Christensen, Britt; Nellemann, Birgitte

2016-01-01

KEY POINT: Erythropoietin (Epo) treatment may induce myogenic differentiation factor (MyoD) expression and prevent apoptosis in satellite cells (SCs) in murine and in vitro models. Endurance training stimulates SC proliferation in vivo in murine and human skeletal muscle. In the present study, we......-receptor interaction. Moreover, endurance training, but not Epo treatment, increases the SC content in type II myofibres, as well as the content of MyoD(+) SCs. Collectively, our results suggest that Epo treatment can regulate human SCs in vivo, supported by Epo receptor mRNA expression in human SCs. In effect, long......-term Epo treatment during disease conditions involving anaemia may impact SCs and warrants further investigation. Satellite cell (SC) proliferation is observed following erythropoitin treatment in vitro in murine myoblasts and endurance training in vivo in human skeletal muscle. The present study aimed...

A method for estimating the accuracy of measurements of optical characteristics of the nuclei of blood cells in the diagnosis of acute leukemia

Science.gov (United States)

Polyakov, E. V.; Nikitaev, V. G.

2017-01-01

The work is devoted to investigation of the random component of the measurement error of the nuclei structure characteristics, which are used in the method of structural elements to measure the differences of blood cells of different types. This method is realized in information-measuring system of the analysis of micropreparations of blood cells in the diagnosis of acute leukemia and its variants.

FOXP3+ T Cells Recruited to Sites of Sterile Skeletal Muscle Injury Regulate the Fate of Satellite Cells and Guide Effective Tissue Regeneration

Science.gov (United States)

Castiglioni, Alessandra; Basso, Veronica; Vezzoli, Michela; Monno, Antonella; Almada, Albert E.; Mondino, Anna; Wagers, Amy J.; Manfredi, Angelo A.; Rovere-Querini, Patrizia

2015-01-01

Muscle injury induces a classical inflammatory response in which cells of the innate immune system rapidly invade the tissue. Macrophages are prominently involved in this response and required for proper healing, as they are known to be important for clearing cellular debris and supporting satellite cell differentiation. Here, we sought to assess the role of the adaptive immune system in muscle regeneration after acute damage. We show that T lymphocytes are transiently recruited into the muscle after damage and appear to exert a pro-myogenic effect on muscle repair. We observed a decrease in the cross-sectional area of regenerating myofibers after injury in Rag2-/- γ-chain-/- mice, as compared to WT controls, suggesting that T cell recruitment promotes muscle regeneration. Skeletal muscle infiltrating T lymphocytes were enriched in CD4+CD25+FOXP3+ cells. Direct exposure of muscle satellite cells to in vitro induced Treg cells effectively enhanced their expansion, and concurrently inhibited their myogenic differentiation. In vivo, the recruitment of Tregs to acutely injured muscle was limited to the time period of satellite expansion, with possibly important implications for situations in which inflammatory conditions persist, such as muscular dystrophies and inflammatory myopathies. We conclude that the adaptive immune system, in particular T regulatory cells, is critically involved in effective skeletal muscle regeneration. Thus, in addition to their well-established role as regulators of the immune/inflammatory response, T regulatory cells also regulate the activity of skeletal muscle precursor cells, and are instrumental for the proper regeneration of this tissue. PMID:26039259

Differential expression of FGF receptors and of myogenic regulatory factors in primary cultures of satellite cells originating from fast (EDL) and slow (Soleus) twitch rat muscles.

Science.gov (United States)

Martelly, I; Soulet, L; Bonnavaud, S; Cebrian, J; Gautron, J; Barritault, D

2000-11-01

In the rat, the fast and slow twitch muscles respectively Extensor digitorum longus (EDL) and Soleus present differential characteristics during regeneration. This suggests that their satellite cells responsible for muscle growth and repair represent distinct cellular populations. We have previously shown that satellite cells dissociated from Soleus and grown in vitro proliferate more readily than those isolated from EDL muscle. Fibroblast growth factors (FGFs) are known as regulators of myoblast proliferation and several studies have revealed a relationship between the response of myoblasts to FGF and the expression of myogenic regulatory factors (MRF) of the MyoD family by myoblasts. Therefore, we presently examined the possibility that the satellite cells isolated from EDL and Soleus muscles differ in the expression of FGF receptors (FGF-R) and of MRF expression. FGF-R1 and -R4 were strongly expressed in proliferating cultures whereas FGF-R2 and R3 were not detected in these cultures. In differentiating cultures, only -R1 was present in EDL satellite cells while FGF-R4 was also still expressed in Soleus cells. Interestingly, the unconventional receptor for FGF called cystein rich FGF receptor (CFR), of yet unknown function, was mainly detected in EDL satellite cell cultures. Soleus and EDL satellite cell cultures also differed in the expression MRFs. These results are consistent with the notion that satellite cells from fast and slow twitch muscles belong to different types of myogenic cells and suggest that satellite cells might play distinct roles in the formation and diversification of fast and slow fibres.

Characterisation of equine satellite cell transcriptomic profile response to ?-hydroxy-?-methylbutyrate (HMB)

OpenAIRE

Szcze?niak, Katarzyna A.; Ciecierska, Anna; Ostaszewski, Piotr; Sadkowski, Tomasz

2016-01-01

?-Hydroxy-?-methylbutyrate (HMB) is a popular ergogenic aid used by human athletes and as a supplement to sport horses, because of its ability to aid muscle recovery, improve performance and body composition. Recent findings suggest that HMB may stimulate satellite cells and affect expressions of genes regulating skeletal muscle cell growth. Despite the scientific data showing benefits of HMB supplementation in horses, no previous study has explained the mechanism of action of HMB in this spe...

K-bar-mesic nuclei

International Nuclear Information System (INIS)

Dote, Akinobu; Akaishi, Yoshinori; Yamazaki, Toshimitsu

2005-01-01

New nuclei 'K-bar-Mesic Nuclei' having the strangeness are described. At first it is shown that the strongly attractive nature of K-bar N interaction is reasoned inductively from consideration of the relation between Kaonic hydrogen atom and Λ (1405) which is an excited state of hyperon Λ. The K-bar N interactions are reviewed and summarized into three categories: 1. Phenomenological approach with density dependent K-bar N interaction (DD), relativistic mean field (RMF) approach, and hybrid of them (RMF+DD). 2. Boson exchange model. 3. Chiral SU(3) theory. The investigation of some light K-bar-nuclei by Akaishi and Yamazaki using phenomenological K-bar N interaction is explained in detail. Studies by antisymmetrized molecular dynamics (AMD) approach are also presented. From these theoretical researches, the following feature of K-bar-mesic nuclei are revealed: 1) Ground state is discrete and bound by 100 MeV or more. 2) Density is very high in side the K-bar-mesic nuclei. 3) Strange structures develop which are not seen in ordinary nuclei. Finally some recent experiments to explore K-bar-mesic nuclei are reviewed. (S. Funahashi)

Vestibular nuclei characterized by calcium-binding protein immunoreactivity and tract tracing in Gekko gecko.

Science.gov (United States)

Song, Jing; Wang, Wenbo; Carr, Catherine E; Dai, Zhendong; Tang, Yezhong

2013-02-01

Immunohistochemical techniques were used to describe the distribution of the calcium binding proteins calretinin, calbindin and parvalbumin as well as synaptic vesicle protein 2 in the vestibular nuclei of the Tokay gecko (Gekko gecko). In addition, tract tracing was used to investigate connections between the vestibular nerves and brainstem nuclei. Seven vestibular nuclei were recognized: the nuclei cerebellaris lateralis (Cerl), vestibularis dorsolateralis (Vedl), ventrolateralis (Vevl), ventromedialis (Vevm), tangentialis (Vetg), ovalis (VeO) and descendens (Veds). Vestibular fibers entered the brainstem with the ascending branch projecting to Vedl and Cerl, the lateral descending branch to Veds, and the medial descending branch to ipsilateral Vevl. Cerl lay most rostral, in the cerebellar peduncle. Vedl, located rostrally, was ventral to the cerebellar peduncle, and consisted of loosely arranged multipolar and monopolar cells. Vevl was found at the level of the vestibular nerve root and contained conspicuously large cells and medium-sized cells. Veds is a large nucleus, the most rostral portion of which is situated lateral and ventral to Vevl, and occupies much of the dorsal brainstem extending caudally through the medulla. VeO is a spherically shaped cell group lateral to the auditory nucleus magnocellularis and dorsal to the caudal part of Vevl. Vevm and Vetg were small in the present study. Except for VeO, all other vestibular nuclei appear directly comparable to counterparts in other reptiles and birds based on their location, cytoarchitecture, and connections, indicating these are conserved features of the vestibular system. Copyright © 2012 Elsevier B.V. All rights reserved.

Candidate solar cell materials for photovoltaic conversion in a solar power satellite /SPS/

Science.gov (United States)

Glaser, P. E.; Almgren, D. W.

1978-01-01

In recognition of the obstacles to solar-generated baseload power on earth, proposals have been made to locate solar power satellites in geosynchronous earth orbit (GEO), where solar energy would be available 24 hours a day during most of the time of the year. In an SPS, the electricity produced by solar energy conversion will be fed to microwave generators forming part of a planar phase-array transmitting antenna. The antenna is designed to precisely direct a microwave beam of very low intensity to one or more receiving antennas at desired locations on earth. At the receiving antenna, the microwave energy will be safely and efficiently reconverted to electricity and then be transmitted to consumers. An SPS system will include a number of satellites in GEO. Attention is given to the photovoltaic option for solar energy conversion in GEO, solar cell requirements, the availability of materials, the implication of large production volumes, requirements for high-volume manufacture of solar cell arrays, and the effects of concentration ratio on solar cell array area.

Spermidine-Activated Satellite Cells Are Associated with Hypoacetylation in ACVR2B and Smad3 Binding to Myogenic Genes in Mice.

Science.gov (United States)

Zhang, Luchu; Gong, Huiying; Sun, Qinwei; Zhao, Ruqian; Jia, Yimin

2018-01-17

Spermidine is an acetyltransferase inhibitor and a specific inducer of autophagy. Recently, spermidine is identified as a potential therapeutic agent for age-related muscle atrophy and inherited myopathies. However, the effect of spermidine on nonpathological skeletal muscle remains unclear. In this study, long-term spermidine administration in mice lowered the mean cross-sectional area of the gastrocnemius muscle and reduced the expression of myosin heavy chain isoforms in the muscle, which was associated with ubiquitination. Moreover, spermidine supplementation induced autophagy in satellite cells and enhanced satellite cell proliferation. ChIP assay revealed that spermidine repressed H3K56ac in the promoter of ACVR2B and lowered the binding affinity of Smad3 to the promoters of Myf5 and MyoD. Altogether, our results indicate that long-term administration of spermidine can activate satellite cells, as well as enhance autophagy, eventually resulting in muscle atrophy. In addition, H3K56ac and Smad3 emerged as key determinants of satellite cell activation.

The molecular responses of skeletal muscle satellite cells to continuous expression of IGF-1: implications for the rescue of induced muscular atrophy in aged rats

Science.gov (United States)

Chakravarthy, M. V.; Booth, F. W.; Spangenburg, E. E.

2001-01-01

Approximately 50% of humans older than 85 years have physical frailty due to weak skeletal muscles. This indicates a need for determining mechanisms to combat this problem. A critical cellular factor for postnatal muscle growth is a population of myogenic precursor cells called satellite cells. Given the complex process of sarcopenia, it has been postulated that, at some point in this process, a limited satellite cell proliferation potential could become rate-limiting to the regrowth of old muscles. It is conceivable that if satellite cell proliferative capacity can be maintained or enhanced with advanced age, sarcopenia could potentially be delayed or prevented. Therefore, the purposes of this paper are to describe whether IGF-I can prevent muscular atrophy induced by repeated cycles of hindlimb immobilization, increase the in vitro proliferation in satellite cells from these muscles and, if so, the molecular mechanisms by which IGF-I mediates this increased proliferation. Our results provide evidence that IGF-I can enhance aged muscle regrowth possibly through increased satellite cell proliferation. The results also suggest that IGF-I enhances satellite cell proliferation by decreasing the cell cycle inhibitor, p27Kip1, through the PI3'-K/Akt pathway. These data provide molecular evidence for IGF-I's rescue effect upon aging-associated skeletal muscle atrophy.

[Automated morphometric evaluation of the chromatin structure of liver cell nuclei after vagotomy].

Science.gov (United States)

Butusova, N N; Zhukotskiĭ, A V; Sherbo, I V; Gribkov, E N; Dubovaia, T K

1989-05-01

The morphometric analysis of the interphase chromatine structure of the hepatic cells nuclei was carried out on the automated TV installation for the quantitative analysis of images "IBAS-2" (by the OPTON firm, the FRG) according to 50 optical and geometric parameters during various periods (1.2 and 4 weeks) after the vagotomy operation. It is determined that upper-molecular organisation of chromatine undergoes the biggest changes one week after operation, and changes of granular component are more informative than changes of the nongranular component (with the difference 15-20%). It was also revealed that chromatine components differ in tinctorial properties, which are evidently dependent on physicochemical characteristics of the chromatine under various functional conditions of the cell. As a result of the correlation analysis the group of morphometric indices of chromatine structure was revealed, which are highly correlated with level of transcription activity of chromatine during various terms after denervation. The correlation quotient of these parameters is 0.85-0.97. The summing up: vagus denervation of the liver causes changes in the morphofunctional organisation of the chromatine.

Nuclei size in relation to nuclear status and aneuploidy rate for 13 chromosomes in donated four cells embryos

DEFF Research Database (Denmark)

Agerholm, I.E.; Hnida, C.; Cruger, D.G.

2008-01-01

Purpose The aim was to elucidate if the nuclear size and number are indicative of aberrant chromosome content in human blastomeres and embryos. Methods The number of nuclei and the nucleus and blastomere size were measured by a computer controlled system for multilevel analysis. Then the nuclei...... were enumerated for 13 chromosomes by a combination of PNA and DNA probes. Results In the mononucleated embryos there was no difference in the mean size of chromosomally normal and abnormal nuclei but a significant difference in the mean nuclei size of nuclei that had gained chromosomes compared...... to nuclei that had lost chromosomes. The nuclei from multinucleated blastomeres had a significant smaller mean size and the frequency of chromosomally aberrant blastomeres was significantly higher. Conclusion The mean nuclear size is not a marker for the chromosome content in mononucleated embryos. However...

Precise mass measurements of exotic nuclei--the SHIPTRAP Penning trap mass spectrometer

International Nuclear Information System (INIS)

Herfurth, F.; Ackermann, D.; Block, M.; Dworschak, M.; Eliseev, S.; Hessberger, F.; Hofmann, S.; Kluge, H.-J.; Maero, G.; Martin, A.; Mazzocco, M.; Rauth, C.; Vorobjev, G.; Blaum, K.; Ferrer, R.; Neidherr, D.; Chaudhuri, A.; Marx, G.; Schweikhard, L.; Neumayr, J.

2007-01-01

The SHIPTRAP Penning trap mass spectrometer has been designed and constructed to measure the mass of short-lived, radioactive nuclei. The radioactive nuclei are produced in fusion-evaporation reactions and separated in flight with the velocity filter SHIP at GSI in Darmstadt. They are captured in a gas cell and transfered to a double Penning trap mass spectrometer. There, the cyclotron frequencies of the radioactive ions are determined and yield mass values with uncertainties ≥4.5·10 -8 . More than 50 nuclei have been investigated so far with the present overall efficiency of about 0.5 to 2%

The activity of satellite cells and myonuclei following 8 weeks of strength training in young men with suppressed testosterone levels

DEFF Research Database (Denmark)

Kvorning, T; Kadi, F; Schjerling, P

2015-01-01

AIM: To investigate how suppression of endogenous testosterone during an 8-week strength training period influences the activity of satellite cells and myonuclei. METHODS: Twenty-two moderately trained young men participated in this randomized, placebo-controlled, and double-blinded intervention...... from the mid-portion of the vastus lateralis muscle. RESULTS: Testosterone resting level in goserelin was 10-20 times lower compared with placebo, and the training-induced increase in the level of testosterone was abolished in goserelin. Training increased satellite cells number in type II fibres by 20...... of testosterone. The data indicate that low testosterone levels could reduce the differentiation of satellite cells to myonuclei via the bone morphogenetic proteins signalling pathway, resulting in reduced increases in lean leg mass....

Exposure of mouse cumulus cell nuclei to porcine ooplasmic extract eliminates TATA box protein binding to chromatin, but has no effect on DNA methylation

OpenAIRE

Tong, Guo Qing; Heng, Boon Chin; Ng, Soon Chye

2006-01-01

Purpose: The low cloning efficiency with SCNT is due to incomplete or partial reprogramming of the donor somatic cell nuclei after microinjection into the enucleated oocyte. A possible solution may be to initiate nuclear reprogramming prior to SCNT.

Measurement of apoptosis by SCAN©, a system for counting and analysis of fluorescently labelled nuclei

Directory of Open Access Journals (Sweden)

Neta Shlezinger

2014-11-01

Full Text Available Apoptosis-like programmed cell death (A-PCD is a universal process common to all types of eukaryotic organisms. Because A-PCD-associated processes are conserved, it is possible to define A-PCD by a standard set of markers. Many of the popular methods to measure A-PCD make use of fluorescent ligands that change in intensity or cellular localization during A-PCD. In single cell organisms, it is possible to quantify levels of A-PCD by scoring the number of apoptotic cells using flow cytometry instruments. In a multicellular organism, quantification of A-PCD is more problematic due to the complex nature of the tissue. The situation is further complicated in filamentous fungi, in which nuclei are divided between compartments, each containing a number of nuclei, which can also migrate between the compartments. We developed SCAN©, a System for Counting and Analysis of Nuclei, and used it to measure A-PCD according to two markers – chromatin condensation and DNA strand breaks. The package includes three modules designed for counting the number of nuclei in multi-nucleated domains, scoring the relative number of nuclei with condensed chromatin, and calculating the relative number of nuclei with DNA strand breaks. The method provides equal or better results compared with manual counting, the analysis is fast and can be applied on large data sets. While we demonstrated the utility of the software for measurement of A-PCD in fungi, the method is readily adopted for measurement of A-PCD in other types of multicellular specimens.

Gamow-Teller decay of T = 1 nuclei to odd-odd N = Z nuclei

Energy Technology Data Exchange (ETDEWEB)

Lisetskiy, A F [National Superconducting Cyclotron Laboratory, MSU, East Lansing, MI 48824 (United States); Gelberg, A [Institute for Nuclear Physics, University of Cologne, 50937 Cologne (Germany); Institute of Physical and Chemical Reasearch (RIKEN), Wako, 351-0198 (Japan); Brentano, P von [Institute for Nuclear Physics, University of Cologne, 50937 Cologne (Germany)

2005-01-01

Transition strengths of Gamow-Teller decay of T{sub z} = {+-}1 nuclei to N = Z odd-odd nuclei have been calculated in a two-nucleon approximation for spherical and deformed nuclei. The results obtained for the latter are quite close to the values obtained by full-space shell-model calculations and to the experiment.

MicroRNA-133 Controls Brown Adipose Determination in Skeletal Muscle Satellite Cells by Targeting Prdm16

DEFF Research Database (Denmark)

Yin, Hang; Pasut, Alessandra; Soleimani, Vahab D

2013-01-01

Brown adipose tissue (BAT) is an energy-dispensing thermogenic tissue that plays an important role in balancing energy metabolism. Lineage-tracing experiments indicate that brown adipocytes are derived from myogenic progenitors during embryonic development. However, adult skeletal muscle stem cells...... (satellite cells) have long been considered uniformly determined toward the myogenic lineage. Here, we report that adult satellite cells give rise to brown adipocytes and that microRNA-133 regulates the choice between myogenic and brown adipose determination by targeting the 3'UTR of Prdm16. Antagonism...... of microRNA-133 during muscle regeneration increases uncoupled respiration, glucose uptake, and thermogenesis in local treated muscle and augments whole-body energy expenditure, improves glucose tolerance, and impedes the development of diet-induced obesity. Finally, we demonstrate that miR-133 levels...

Three-dimensional maps of all chromosomes in human male fibroblast nuclei and prometaphase rosettes.

Directory of Open Access Journals (Sweden)

Andreas Bolzer

2005-05-01

Full Text Available Studies of higher-order chromatin arrangements are an essential part of ongoing attempts to explore changes in epigenome structure and their functional implications during development and cell differentiation. However, the extent and cell-type-specificity of three-dimensional (3D chromosome arrangements has remained controversial. In order to overcome technical limitations of previous studies, we have developed tools that allow the quantitative 3D positional mapping of all chromosomes simultaneously. We present unequivocal evidence for a probabilistic 3D order of prometaphase chromosomes, as well as of chromosome territories (CTs in nuclei of quiescent (G0 and cycling (early S-phase human diploid fibroblasts (46, XY. Radial distance measurements showed a probabilistic, highly nonrandom correlation with chromosome size: small chromosomes-independently of their gene density-were distributed significantly closer to the center of the nucleus or prometaphase rosette, while large chromosomes were located closer to the nuclear or rosette rim. This arrangement was independently confirmed in both human fibroblast and amniotic fluid cell nuclei. Notably, these cell types exhibit flat-ellipsoidal cell nuclei, in contrast to the spherical nuclei of lymphocytes and several other human cell types, for which we and others previously demonstrated gene-density-correlated radial 3D CT arrangements. Modeling of 3D CT arrangements suggests that cell-type-specific differences in radial CT arrangements are not solely due to geometrical constraints that result from nuclear shape differences. We also found gene-density-correlated arrangements of higher-order chromatin shared by all human cell types studied so far. Chromatin domains, which are gene-poor, form a layer beneath the nuclear envelope, while gene-dense chromatin is enriched in the nuclear interior. We discuss the possible functional implications of this finding.

Neuron-Derived ADAM10 Production Stimulates Peripheral Nerve Injury-Induced Neuropathic Pain by Cleavage of E-Cadherin in Satellite Glial Cells.

Science.gov (United States)

Li, Jian; Ouyang, Qing; Chen, Cheng-Wen; Chen, Qian-Bo; Li, Xiang-Nan; Xiang, Zheng-Hua; Yuan, Hong-Bin

2017-09-01

Increasing evidence suggests the potential involvement of metalloproteinase family proteins in the pathogenesis of neuropathic pain, although the underlying mechanisms remain elusive. Using the spinal nerve ligation model, we investigated whether ADAM10 proteins participate in pain regulation. By implementing invitro methods, we produced a purified culture of satellite glial cells to study the underlying mechanisms of ADAM10 in regulating neuropathic pain. Results showed that the ADAM10 protein was expressed in calcitonin gene-related peptide (CGRP)-containing neurons of the dorsal root ganglia, and expression was upregulated following spinal nerve ligation surgery invivo. Intrathecal administration of GI254023X, an ADAM10 selective inhibitor, to the rats one to three days after spinal nerve ligation surgery attenuated the spinal nerve ligation-induced mechanical allodynia and thermal hyperalgesia. Intrathecal injection of ADAM10 recombinant protein simulated pain behavior in normal rats to a similar extent as those treated by spinal nerve ligation surgery. These results raised a question about the relative contribution of ADAM10 in pain regulation. Further results showed that ADAM10 might act by cleaving E-cadherin, which is mainly expressed in satellite glial cells. GI254023X reversed spinal nerve ligation-induced downregulation of E-cadherin and activation of cyclooxygenase 2 after spinal nerve ligation. β-catenin, which creates a complex with E-cadherin in the membranes of satellite glial cells, was also downregulated by spinal nerve ligation surgery in satellite glial cells. Finally, knockdown expression of β-catenin by lentiviral infection in purified satellite glial cells increased expression of inducible nitric oxide synthase and cyclooxygenase 2. Our findings indicate that neuron-derived ADAM10 production stimulates peripheral nerve injury-induced neuropathic pain by cleaving E-cadherin in satellite glial cells. © 2017 American Academy of Pain Medicine

Effect of β-hydroxy-β-methylbutyrate on miRNA expression in differentiating equine satellite cells exposed to hydrogen peroxide.

Science.gov (United States)

Chodkowska, Karolina A; Ciecierska, Anna; Majchrzak, Kinga; Ostaszewski, Piotr; Sadkowski, Tomasz

2018-01-01

Skeletal muscle injury activates satellite cells to initiate processes of proliferation, differentiation, and hypertrophy in order to regenerate muscle fibers. The number of microRNAs and their target genes are engaged in satellite cell activation. β-Hydroxy-β-methylbutyrate (HMB) is known to prevent exercise-induced muscle damage. The purpose of this study was to evaluate the effect of HMB on miRNA and relevant target gene expression in differentiating equine satellite cells exposed to H 2 O 2 . We hypothesized that HMB may regulate satellite cell activity, proliferation, and differentiation, hence attenuate the pathological processes induced during an in vitro model of H 2 O 2 -related injury by changing the expression of miRNAs. Equine satellite cells (ESC) were isolated from the samples of skeletal muscle collected from young horses. ESC were treated with HMB (24 h) and then exposed to H 2 O 2 (1 h). For the microRNA and gene expression assessment microarrays, technique was used. Identified miRNAs and genes were validated using real-time qPCR. Cell viability, oxidative stress, and cell damage were measured using colorimetric method and flow cytometry. Analysis of miRNA and gene profile in differentiating ESC pre-incubated with HMB and then exposed to H 2 O 2 revealed difference in the expression of 27 miRNAs and 4740 genes, of which 344 were potential target genes for identified miRNAs. Special attention was focused on differentially expressed miRNAs and their target genes involved in processes related to skeletal muscle injury. Western blot analysis showed protein protection in HMB-pre-treated group compared to control. The viability test confirmed that HMB enhanced cell survival after the hydrogen peroxide exposition. Our results suggest that ESC pre-incubated with HMB and exposed to H 2 O 2 could affect expression on miRNA levels responsible for skeletal muscle development, cell proliferation and differentiation, and activation of tissue repair after

Pairing correlations in nuclei

International Nuclear Information System (INIS)

Baba, C.V.K.

1988-01-01

There are many similarities between the properties of nucleons in nuclei and electrons in metals. In addition to the properties explainable in terms of independent particle motion, there are many important co-operative effects suggesting correlated motion. Pairing correlation which leads to superconductivity in metals and several important properties in nuclei , is an exmple of such correlations. An attempt has been made to review the effects of pairing correlations in nuclei. Recent indications of reduction in pairing correlations at high angular momenta is discussed. A comparision between pairing correlations in the cases of nuclei and electrons in metals is attempted. (author). 20 refs., 10 figs

Satellite cell proliferation in adult skeletal muscle

Science.gov (United States)

Booth, Frank W. (Inventor); Thomason, Donald B. (Inventor); Morrison, Paul R. (Inventor); Stancel, George M. (Inventor)

1995-01-01

Novel methods of retroviral-mediated gene transfer for the in vivo corporation and stable expression of eukaryotic or prokaryotic foreign genes in tissues of living animals is described. More specifically, methods of incorporating foreign genes into mitotically active cells are disclosed. The constitutive and stable expression of E. coli .beta.-galactosidase gene under the promoter control of the Moloney murine leukemia virus long terminal repeat is employed as a particularly preferred embodiment, by way of example, establishes the model upon which the incorporation of a foreign gene into a mitotically-active living eukaryotic tissue is based. Use of the described methods in therapeutic treatments for genetic diseases, such as those muscular degenerative diseases, is also presented. In muscle tissue, the described processes result in genetically-altered satellite cells which proliferate daughter myoblasts which preferentially fuse to form a single undamaged muscle fiber replacing damaged muscle tissue in a treated animal. The retroviral vector, by way of example, includes a dystrophin gene construct for use in treating muscular dystrophy. The present invention also comprises an experimental model utilizable in the study of the physiological regulation of skeletal muscle gene expression in intact animals.

Topology of genes and nontranscribed sequences in human interphase nuclei

International Nuclear Information System (INIS)

Scheuermann, Markus O.; Tajbakhsh, Jian; Kurz, Anette; Saracoglu, Kaan; Eils, Roland; Lichter, Peter

2004-01-01

Knowledge about the functional impact of the topological organization of DNA sequences within interphase chromosome territories is still sparse. Of the few analyzed single copy genomic DNA sequences, the majority had been found to localize preferentially at the chromosome periphery or to loop out from chromosome territories. By means of dual-color fluorescence in situ hybridization (FISH), immunolabeling, confocal microscopy, and three-dimensional (3D) image analysis, we analyzed the intraterritorial and nuclear localization of 10 genomic fragments of different sequence classes in four different human cell types. The localization of three muscle-specific genes FLNA, NEB, and TTN, the oncogene BCL2, the tumor suppressor gene MADH4, and five putatively nontranscribed genomic sequences was predominantly in the periphery of the respective chromosome territories, independent from transcriptional status and from GC content. In interphase nuclei, the noncoding sequences were only rarely found associated with heterochromatic sites marked by the satellite III DNA D1Z1 or clusters of mammalian heterochromatin proteins (HP1α, HP1β, HP1γ). However, the nontranscribed sequences were found predominantly at the nuclear periphery or at the nucleoli, whereas genes tended to localize on chromosome surfaces exposed to the nuclear interior

Otolith-Canal Convergence In Vestibular Nuclei Neurons

Science.gov (United States)

Dickman, J. David; Si, Xiao-Hong

2002-01-01

The current final report covers the period from June 1, 1999 to May 31, 2002. The primary objective of the investigation was to determine how information regarding head movements and head position relative to gravity is received and processed by central vestibular nuclei neurons in the brainstem. Specialized receptors in the vestibular labyrinths of the inner ear function to detect angular and linear accelerations of the head, with receptors located in the semicircular canals transducing rotational head movements and receptors located in the otolith organs transducing changes in head position relative to gravity or linear accelerations of the head. The information from these different receptors is then transmitted to central vestibular nuclei neurons which process the input signals, then project the appropriate output information to the eye, head, and body musculature motor neurons to control compensatory reflexes. Although a number of studies have reported on the responsiveness of vestibular nuclei neurons, it has not yet been possible to determine precisely how these cells combine the information from the different angular and linear acceleration receptors into a correct neural output signal. In the present project, rotational and linear motion stimuli were separately delivered while recording responses from vestibular nuclei neurons that were characterized according to direct input from the labyrinth and eye movement sensitivity. Responses from neurons receiving convergent input from the semicircular canals and otolith organs were quantified and compared to non-convergent neurons.

Age-specific functional epigenetic changes in p21 and p16 in injury-activated satellite cells

Science.gov (United States)

Li, Ju; Han, Suhyoun; Cousin, Wendy; Conboy, Irina M.

2014-01-01

The regenerative capacity of muscle dramatically decreases with age because old muscle stem cells fail to proliferate in response to tissue damage. Here we uncover key age-specific differences underlying this proliferative decline: namely, the genetic loci of CDK inhibitors (CDKI) p21 and p16 are more epigenetically silenced in young muscle stem cells, as compared to old, both in quiescent cells and those responding to tissue injury. Interestingly, phosphorylated ERK (pERK) induced in these cells by ectopic FGF-2 is found in association with p21 and p16 promoters, and moreover, only in the old cells. Importantly, in the old satellite cells FGF-2/pERK silences p21 epigenetically and transcriptionally, which leads to reduced p21 protein levels and enhanced cell proliferation. In agreement with the epigenetic silencing of the loci, young muscle stem cells do not depend as much as old on ectopic FGF/pERK for their myogenic proliferation. In addition, other CDKIs, such asp15INK4B and p27KIP1, become elevated in satellite cells with age, confirming and explaining the profound regenerative defect of old muscle. This work enhances our understanding of tissue aging, promoting strategies for combating age-imposed tissue degeneration. PMID:25447026

The influence of capillarization on satellite cell pool expansion and activation following exercise-induced muscle damage in healthy young men.

Science.gov (United States)

Nederveen, Joshua P; Joanisse, Sophie; Snijders, Tim; Thomas, Aaron C Q; Kumbhare, Dinesh; Parise, Gianni

2018-03-15

Skeletal muscle stem cells (satellite cells) play a crucial role in repair and remodelling of muscle in response to exercise. Satellite cells are in close spatial proximity to muscle capillaries and therefore may be influenced by them. In this study, we describe the activation and expansion of the satellite cell pool in response to eccentric contraction-induced muscle damage in individuals with significantly different levels of muscle capillarization. Individuals with greater capillarization and capacity for muscle perfusion demonstrated enhanced activation and/or expansion of the satellite cell pool allowing for an accelerated recovery of muscle function. These results provide insight into the critical relationship between muscle capillarization and satellite cells during skeletal muscle repair. Factors that determine the skeletal muscle satellite cell (SC) response remain incompletely understood. It is known, however, that SC activation status is closely related to the anatomical relationship between SCs and muscle capillaries. We investigated the impact of muscle fibre capillarization on the expansion and activation status of SCs following a muscle-damaging exercise protocol in healthy young men. Twenty-nine young men (21 ± 0.5 years) performed 300 unilateral eccentric contractions (180 deg s -1 ) of the knee extensors. Percutaneous muscle biopsies from the vastus lateralis and blood samples from the antecubital vein were taken prior to (Pre) exercise and at 6, 24, 72 and 96 h of post-exercise recovery. A comparison was made between subjects who had a relative low mixed muscle capillary-to-fibre perimeter exchange index (CFPE; Low group) and high mixed muscle CFPE index (High group) at baseline. Type I and type II muscle fibre size, myonuclear content, capillarization, and SC response were determined via immunohistochemistry. Overall, there was a significant correlation (r = 0.39; P < 0.05) between the expansion of SC content (change in total Pax7

Nuclei and quantum worlds

International Nuclear Information System (INIS)

Chomaz, Ph.

2000-01-01

This document gathers the slides and their commentaries that have been presented at the conference 'physics and fundamental questions' by P. Chomaz. The author reviews the different quantum aspects of nuclei: tunnel effect, symmetries, magic numbers, wave functions, size, shapes and deformations. The author shows that nuclei are quantum objects of great complexity, their structures are not yet well understood and the study of exotic nuclei will continue bringing valuable information

Solar array experiments on the Sphinx satellite

Science.gov (United States)

Stevens, N. J.

1973-01-01

The Space Plasma, High Voltage Interaction Experiment (SPHINX) is the name given to an auxiliary payload satellite scheduled to be launched in January 1974. The principal experiments carried on this satellite are specifically designed to obtain the engineering data on the interaction of high voltage systems with the space plasma. The classes of experiments are solar array segments, insulators, insulators with pin holes and conductors. The satellite is also carrying experiments to obtain flight data on three new solar array configurations; the edge illuminated-multijunction cells, the Teflon encased cells and the violet cells.

Superdeformed nuclei

International Nuclear Information System (INIS)

Janssens, R.V.F.; Khoo, T.L.

1991-01-01

Superdeformation was first proposed some twenty years ago to explain the fission isomers observed in some actinide nuclei. It was later realized that superdeformed shapes can occur at high angular momentum in lighter nuclei. The interest in the mechanisms responsible for these exotic shapes has increased enormously with the discovery of a superdeformed band of nineteen discrete lines in 152 Dy (8). At about the same time, evidence for highly deformed nuclei (axis ratio 3:2) was also reported near 132 Ce(9). Striking properties emerged from the first experiments, such as the essentially constant energy spacing between transitions (picket-fence spectra), the unexpectedly strong population of superdeformed bands at high spins, and the apparent lack of a link between the superdeformed states and the yrast levels. These findings were reviewed by Nolan and Twin. The present article follows upon their work and discusses the wealth of information that has since become available. This includes the discovery of a new island of superdeformation near A = 190, the detailed spectroscopy of ground and excited bands in the superdeformed well near A = 150 and A = 190, the surprising occurrence of superdeformed bands with identical transition energies in nuclei differing by one or two mass units, and the improved understanding of mechanisms responsible for the feeding into and the decay out of the superdeformed states

Detection of nuclei in 4D Nomarski DIC microscope images of early Caenorhabditis elegans embryos using local image entropy and object tracking

Directory of Open Access Journals (Sweden)

Hamahashi Shugo

2005-05-01

Full Text Available Abstract Background The ability to detect nuclei in embryos is essential for studying the development of multicellular organisms. A system of automated nuclear detection has already been tested on a set of four-dimensional (4D Nomarski differential interference contrast (DIC microscope images of Caenorhabditis elegans embryos. However, the system needed laborious hand-tuning of its parameters every time a new image set was used. It could not detect nuclei in the process of cell division, and could detect nuclei only from the two- to eight-cell stages. Results We developed a system that automates the detection of nuclei in a set of 4D DIC microscope images of C. elegans embryos. Local image entropy is used to produce regions of the images that have the image texture of the nucleus. From these regions, those that actually detect nuclei are manually selected at the first and last time points of the image set, and an object-tracking algorithm then selects regions that detect nuclei in between the first and last time points. The use of local image entropy makes the system applicable to multiple image sets without the need to change its parameter values. The use of an object-tracking algorithm enables the system to detect nuclei in the process of cell division. The system detected nuclei with high sensitivity and specificity from the one- to 24-cell stages. Conclusion A combination of local image entropy and an object-tracking algorithm enabled highly objective and productive detection of nuclei in a set of 4D DIC microscope images of C. elegans embryos. The system will facilitate genomic and computational analyses of C. elegans embryos.

Inflammatory sensitization of nociceptors depends on activation of NMDA receptors in DRG satellite cells.

Science.gov (United States)

Ferrari, Luiz Fernando; Lotufo, Celina Monteiro; Araldi, Dionéia; Rodrigues, Marcos A; Macedo, Larissa P; Ferreira, Sérgio H; Parada, Carlos Amilcar

2014-12-23

The present study evaluated the role of N-methyl-D-aspartate receptors (NMDARs) expressed in the dorsal root ganglia (DRG) in the inflammatory sensitization of peripheral nociceptor terminals to mechanical stimulation. Injection of NMDA into the fifth lumbar (L5)-DRG induced hyperalgesia in the rat hind paw with a profile similar to that of intraplantar injection of prostaglandin E2 (PGE2), which was significantly attenuated by injection of the NMDAR antagonist D(-)-2-amino-5-phosphonopentanoic acid (D-AP-5) in the L5-DRG. Moreover, blockade of DRG AMPA receptors by the antagonist 6,7-dinitroquinoxaline-2,3-dione had no effect in the PGE2-induced hyperalgesia in the paw, showing specific involvement of NMDARs in this modulatory effect and suggesting that activation of NMDAR in the DRG plays an important role in the peripheral inflammatory hyperalgesia. In following experiments we observed attenuation of PGE2-induced hyperalgesia in the paw by the knockdown of NMDAR subunits NR1, NR2B, NR2D, and NR3A with antisense-oligodeoxynucleotide treatment in the DRG. Also, in vitro experiments showed that the NMDA-induced sensitization of cultured DRG neurons depends on satellite cell activation and on those same NMDAR subunits, suggesting their importance for the PGE2-induced hyperalgesia. In addition, fluorescent calcium imaging experiments in cultures of DRG cells showed induction of calcium transients by glutamate or NMDA only in satellite cells, but not in neurons. Together, the present results suggest that the mechanical inflammatory nociceptor sensitization is dependent on glutamate release at the DRG and subsequent NMDAR activation in satellite glial cells, supporting the idea that the peripheral hyperalgesia is an event modulated by a glutamatergic system in the DRG.

Structure of neutron-rich nuclei

International Nuclear Information System (INIS)

Nazarewicz, W.

2000-01-01

Complete text of publication follows. The uncharted regions of the (N,Z) plane contain information that can answer many questions of fundamental importance for science: How many protons and neutrons can be clustered together by the strong interaction to form a bound nucleus? What are the proton and neutron magic numbers of the exotic nuclei? What are the properties of very short-lived exotic nuclei with extreme neutron-to-proton ratios? What is the effective nucleon-nucleon interaction in a nucleus that has a very large neutron excess? Nuclear life far from stability is different from that around the stability line; the promised access to completely new combinations of proton and neutron numbers offers prospects for new structural phenomena. The main objective of this talk is to discuss some of the challenges and opportunities of research with exotic nuclei. The covered topics will include: Theoretical challenges; Skins and halos in heavy nuclei; Shape coexistence in exotic nuclei; Beta-decays of neutron-rich nuclei. (author)

X-ray reflection from cold matter in the nuclei of active galaxies

International Nuclear Information System (INIS)

Pounds, K.A.; Nandra, K.; Stewart, G.C.; George, I.M.; Fabian, A.C.

1990-01-01

The evidence accumulated over the past few years for strong soft X-ray emission from active galactic nuclei has been interpreted as black body emission from the innermost stable region of an accretion disk feeding the putative black hole at the centre of the active nucleus, a view given strong support by the rapid variability of some soft X-ray components. More recently, new X-ray data from the Exosat and Ginga satellites have revealed a second indicator of optically thick matter in the vicinity of the active nucleus, in the form of an iron K-fluorescence line at ≅ 6.4 keV. We report the discovery of two further common features of continuum absorption and reflection, revealed in a composite spectrum from twelve Ginga observations of Seyfert-type active galactic nuclei. Most of these spectral features are shown to be well modelled by reprocessing of the hard X-ray power-law continuum in a slab (or perhaps a disk) of cold matter. There is also evidence for a substantial line-of-sight column of photoionized material. (author)

Energetic Nuclei, Superdensity and Biomedicine

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Baldin, A. M.

1977-01-01

High-energy, relativistic nuclei were first observed in cosmic rays. Studing these nuclei has provided an opportunity for analyzing the composition of cosmic rays and for experimentally verifying principles governing the behavior of nuclear matter at high and super-high temperatures. Medical research using accelerated nuclei is suggested.…

Problem of ''deformed'' superheavy nuclei

International Nuclear Information System (INIS)

Sobiczewski, A.; Patyk, Z.; Muntian, I.

2000-08-01

Problem of experimental confirmation of deformed shapes of superheavy nuclei situated in the neighbourhood of 270 Hs is discussed. Measurement of the energy E 2+ of the lowest 2+ state in even-even species of these nuclei is considered as a method for this confirmation. The energy is calculated in the cranking approximation for heavy and superheavy nuclei. The branching ratio p 2+ /p 0+ between α decay of a nucleus to this lowest 2+ state and to the ground state 0+ of its daughter is also calculated for these nuclei. The results indicate that a measurement of the energy E 2+ for some superheavy nuclei by electron or α spectroscopy is a promising method for the confirmation of their deformed shapes. (orig.)

Bands and chromosome arrangement in interphase nuclei

International Nuclear Information System (INIS)

Bianchi, N.O.; Bianchi, M.A.; Matayoshi, T.

1977-01-01

Chromosomes from the vole mouse Akodon dolores and from laboratory mouse showed the presence of G-bands after 3 minutes digestion with trypsin and Giemsa stain. Simultaneously, 30- to 40% of the interphase nuclei exhibited a dark ring parallel to the nuclear contour and a radial array of the chromatin in the internal and external regions of the ring. The origin and meaning of this ring image was analyzed by combining progressive trypsinizations with other methods such as C-banding procedures, autoradiography with 3 HTdR, staining with quinacrine mustard and 33258 Hoechst fluorochromes. Moreover, the presence of the dark ring was also investigated in cells treated with actinomycin and in control cells not subjected to any treatment. The results obtained allowed to assume that in interphase nuclei the chromosomes have chromatin bridges which connect the dark G-bands and that these bridges are probably involved in maintaining an ordered architecture of the nucleus with fixed chromosome positions in regard to the nuclear envelope and in regard to other chromosomes. Trypsinization produces a disruption of the interphase chromatin arrangement and the subsequent appearance of a dark ring formed by the combination of constitutive heterochromatin and dark G-bands. (auth.)

Critical-point nuclei

International Nuclear Information System (INIS)

Clark, R.M.

2004-01-01

It has been suggested that a change of nuclear shape may be described in terms of a phase transition and that specific nuclei may lie close to the critical point of the transition. Analytical descriptions of such critical-point nuclei have been introduced recently and they are described briefly. The results of extensive searches for possible examples of critical-point behavior are presented. Alternative pictures, such as describing bands in the candidate nuclei using simple ΔK = 0 and ΔK = 2 rotational-coupling models, are discussed, and the limitations of the different approaches highlighted. A possible critical-point description of the transition from a vibrational to rotational pairing phase is suggested

IN VITRO EXAMINATION OF ONTOGENESIS OF DEVELOPING NEURONAL CELLS IN VAGAL NUCLEI IN MEDULLA OBLONGATA IN NEWBORNS

Science.gov (United States)

Islami, Hilmi; Shabani, Ragip; Bexheti, Sadi; Behluli, Ibrahim; Šukalo, Aziz; Raka, Denis; Koliqi, Rozafa; Haliti, Naim; Dauti, Hilmi; Krasniqi, Shaip; Disha, Mentor

2008-01-01

The development of neuron cells in vagal nerve nuclei in medulla oblongata was studied in vitro in live newborns and stillborns from different cases. Morphological changes were studied in respiratory nuclei of dorsal motor centre (DMNV) and nucleus tractus solitarius (NTS) in medulla oblongata. The material from medulla oblongata was fixated in 10μ buffered formalin solution. Fixated material was cut in series of 10μ thickness, with starting point from obex in ± 4 mm thickness. Special histochemical and histoenzymatic methods for central nervous system were used: cresyl echt violet coloring, tolyidin blue, Sevier-Munger modification and Grimelius coloring. In immature newborns (abortions and immature) in dorsal motor nucleus of the vagus (DMNV) population stages S1, S2, S3 are dominant. In neuron population in vagal sensory nuclei (NTS) stages S1, S2 are dominant. In more advanced stages of development of newborns (premature), in DMNV stages S3 and S4 are seen and in NTS stages S2 and S3 are dominant. In mature phase of newborns (maturity) in vagal nucleus DMNV stages S5 and S6 are dominant, while in sensory nucleus NTS stages S4 and S5 are dominant. These data suggest that neuron population in dorsal motor nucleus of the vagus (DMNV) are more advanced in neuronal maturity in comparison with sensory neuron population of vagal sensory nucleus NTS. This occurrence shows that phylogenetic development of motor complex is more advanced than the sensory one, which is expected to take new information’s from the extra uterine life after birth (extra uterine vagal phenotype) PMID:19125713

Cluster structures in light nuclei

International Nuclear Information System (INIS)

Horiuchi, H.

2000-01-01

Complete text of publication follows. Clustering in neutron-rich nuclei is discussed. To understand the novel features (1,2,3) of the clustering in neutron-rich nuclei, the basic features of the clustering in stable nuclei (4) are briefly reviewed. In neutron-rich nuclei, the requirement of the stability of clusters is questioned and the threshold rule is no more obeyed. Examples of clustering in Be and B isotopes (4,5) are discussed in some detail. Possible existence of novel type of clustering near neutron dripline is suggested (1). (author)

Implications of the Galilean satellites ice envelope explosions. 3

International Nuclear Information System (INIS)

Agafonova, I.I.; Drobyshevski, E.M.

1985-01-01

Secondary explosions of the primary ice fragments ejected in the explosion of the electrolyzed massive ice envelopes of the Galilean satellites are capable of imparting velocities of up to 5 km s -1 to the secondary fragments. As a result, the secondary fragments can enter the orbits of the irregular satellites and the Trojan libration orbits. Since the icy mix of the fragments contains hydrocarbons and particulate material (silicates and the like), after ice sublimation from the surface layers the Trojans should reveal type C and RD spectra typical for Jupiter's irregular satellites, comet nuclei and other distant ice bodies of similar origin. Among the Trojans there cannot be rocky or metallic objects which are known to exist in the main asteroid belt. It is shown that a velocity perturbation of 150-200 m s -1 resulting from a purely mechanical impact of two bodies may be sufficient to move collision fragments from the orbits of the Trojans to horseshoe-shaped trajectories with a subsequent transfer to the cometary orbits of Jupiter's family. (Auth.)

miR-378 attenuates muscle regeneration by delaying satellite cell activation and differentiation in mice.

Science.gov (United States)

Zeng, Ping; Han, Wanhong; Li, Changyin; Li, Hu; Zhu, Dahai; Zhang, Yong; Liu, Xiaohong

2016-09-01

Skeletal muscle mass and homeostasis during postnatal muscle development and regeneration largely depend on adult muscle stem cells (satellite cells). We recently showed that global overexpression of miR-378 significantly reduced skeletal muscle mass in mice. In the current study, we used miR-378 transgenic (Tg) mice to assess the in vivo functional effects of miR-378 on skeletal muscle growth and regeneration. Cross-sectional analysis of skeletal muscle tissues showed that the number and size of myofibers were significantly lower in miR-378 Tg mice than in wild-type mice. Attenuated cardiotoxin-induced muscle regeneration in miR-378 Tg mice was found to be associated with delayed satellite cell activation and differentiation. Mechanistically, miR-378 was found to directly target Igf1r in muscle cells both in vitro and in vivo These miR-378 Tg mice may provide a model for investigating the physiological and pathological roles of skeletal muscle in muscle-associated diseases in humans, particularly in sarcopenia. © The Author 2016. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Inelastic collisions of neon-22 nuclei with nuclei in photoemulsion at 90 GeV/c momentum

International Nuclear Information System (INIS)

Vokalova, A.; Krasnov, S.A.; Tolstov, K.D.

1985-01-01

The experimental data obtained according to the analysis of 4303 inelastic interactions of the relativistic neon-22 nuclei with the nuclei in photoemulsion are presented. The multiplicities and angular distributions are shown as the functions of the disintegration degree of the colliding nuclei. It is shown that the same number of interacting nucleons of the projectile neon and carbon nuclei are connected with the different impact parameters with the target nucleus

Interactions of 10.6 GeV/n gold nuclei with light and heavy target nuclei in nuclear emulsion

International Nuclear Information System (INIS)

Cherry, M.L.; Denes-Jones, P.

1994-03-01

We have investigated the particle production and fragmentation of nuclei participating in the interactions of 10.6 GeV/n gold nuclei in nuclear emulsions. A new criteria has been developed to distinguish between the interactions of these gold nuclei with the light (H, C, N, O) and heavy (Ag, Br) target nuclei in the emulsion. This has allowed separate analyzes of the multiplicity and pseudo-rapidity distributions of the singly charged particles emitted in Au-(H, C, N, O) and Au-(Ag, Br) interactions, as well as of the models of breakup of the projectile and target nuclei. The pseudo-rapidity distributions show strong forward asymmetries, particularly for the interactions with the light nuclei. Heavy target nuclei produce a more severe breakup of the projectile gold nucleus than do the lighter targets. A negative correlation between the number of fragments emitted from the target nuclei and the degree of centrality of the collisions has been observed, which can be attributed to the total destruction of the relatively light target nuclei by these very heavy projectile nuclei. (author). 14 refs, 11 figs, 1 tab

Fibromodulin: a master regulator of myostatin controlling progression of satellite cells through a myogenic program.

Science.gov (United States)

Lee, Eun Ju; Jan, Arif Tasleem; Baig, Mohammad Hassan; Ashraf, Jalaluddin Mohammad; Nahm, Sang-Soep; Kim, Yong-Woon; Park, So-Young; Choi, Inho

2016-08-01

Differentiation of muscle satellite cells (MSCs) involves interaction of the proteins present in the extracellular matrix (ECM) with MSCs to regulate their activity, and therefore phenotype. Herein, we report fibromodulin (FMOD), a member of the proteoglycan family participating in the assembly of ECM, as a novel regulator of myostatin (MSTN) during myoblast differentiation. In addition to having a pronounced effect on the expression of myogenic marker genes [myogenin (MYOG) and myosin light chain 2 (MYL2)], FMOD was found to maintain the transcriptional activity of MSTN Moreover, coimmunoprecipitation and in silico studies performed to investigate the interaction of FMOD helped confirm that it antagonizes MSTN function by distorting its folding and preventing its binding to activin receptor type IIB. Furthermore, in vivo studies revealed that FMOD plays an active role in healing by increasing satellite cell recruitment to sites of injury. Together, these findings disclose a hitherto unrecognized regulatory role for FMOD in MSCs and highlight new mechanisms whereby FMOD circumvents the inhibitory effects of MSTN and triggers myoblast differentiation. These findings offer a basis for the design of novel MSTN inhibitors that promote muscle regeneration after injury or for the development of pharmaceutical agents for the treatment of different muscle atrophies.-Lee, E. J., Jan, A. T., Baig, M. H., Ashraf, J. M., Nahm, S.-S., Kim, Y.-W., Park, S.-Y., Choi, I. Fibromodulin: a master regulator of myostatin controlling progression of satellite cells through a myogenic program. © FASEB.

Activation of satellite cells and the regeneration of human skeletal muscle are expedited by ingestion of nonsteroidal anti-inflammatory medication

DEFF Research Database (Denmark)

Mackey, Abigail L; Rasmussen, Lotte Klejs; Kadi, Fawzi

2016-01-01

muscles of one leg. Muscle biopsies were collected from the vastus lateralis muscles before and after stimulation (2.5 h and 2, 7, and 30 d) and were assessed for satellite cells and regeneration by immunohistochemistry and real-time RT-PCR, and we also measured telomere length. After injury, and compared...... activation of satellite cells and muscle remodeling during large-scale regeneration of injured human skeletal muscle.-Mackey, A. L., Rasmussen, L. K., Kadi, F., Schjerling, P., Helmark, I. C., Ponsot, E., Aagaard, P., Durigan, J. L. Q., Kjaer, M. Activation of satellite cells and the regeneration of human......With this study we investigated the role of nonsteroidal anti-inflammatory drugs (NSAIDs) in human skeletal muscle regeneration. Young men ingested NSAID [1200 mg/d ibuprofen (IBU)] or placebo (PLA) daily for 2 wk before and 4 wk after an electrical stimulation-induced injury to the leg extensor...

Quarks in Few Body Nuclei

Directory of Open Access Journals (Sweden)

Holt Roy J.

2016-01-01

Full Text Available Electron scattering at very high Bjorken x from hadrons provides an excellent test of models, has an important role in high energy physics, and from nuclei, provides a window into short range correlations. Light nuclei have a key role because of the relatively well-known nuclear structure. The development of a novel tritium target for Jefferson Lab has led to renewed interest in the mass three system. For example, deep inelastic scattering experiments in the light nuclei provide a powerful means to determine the neutron structure function. The isospin dependence of electron scattering from mass-3 nuclei provide information on short range correlations in nuclei. The program using the new tritium target will be presented along with a summary of other experiments aimed at revealing the large-x structure of the nucleon.

FOP is a centriolar satellite protein involved in ciliogenesis.

Directory of Open Access Journals (Sweden)

Joanna Y Lee

Full Text Available Centriolar satellites are proteinaceous granules that are often clustered around the centrosome. Although centriolar satellites have been implicated in protein trafficking in relation to the centrosome and cilium, the details of their function and composition remain unknown. FOP (FGFR1 Oncogene Partner is a known centrosome protein with homology to the centriolar satellite proteins FOR20 and OFD1. We find that FOP partially co-localizes with the satellite component PCM1 in a cell cycle-dependent manner, similarly to the satellite and cilium component BBS4. As for BBS4, FOP localization to satellites is cell cycle dependent, with few satellites labeled in G1, when FOP protein levels are lowest, and most labeled in G2. FOP-FGFR1, an oncogenic fusion that causes a form of leukemia called myeloproliferative neoplasm, also localizes to centriolar satellites where it increases tyrosine phosphorylation. Depletion of FOP strongly inhibits primary cilium formation in human RPE-1 cells. These results suggest that FOP is a centriolar satellite cargo protein and, as for several other satellite-associated proteins, is involved in ciliogenesis. Localization of the FOP-FGFR1 fusion kinase to centriolar satellites may be relevant to myeloproliferative neoplasm disease progression.

Interferometric measurements of dry mass content in nuclei and cytoplasm in the life cycle of antheridial filaments cells of Chara vulgaris L. in their successive developmental stages

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Hanna Kuran

2015-01-01

Full Text Available Interferometric measurements of the nucleus and cytoplasm dry mass during interphase in the successive stages of development of antheridial filaments of Chara vulgaris demonstrated that the dry mass and surface area of cell nuclei double in size in each of the successive generations of the filaments, whereas neither the surface nor the dry mass of the cytoplasm increase in such proportion in the same period. In the successive stages of development of the antheridial filaments the dry mass and surface area of the nuclei and cytoplasm gradually diminish.

Complete destruction of heavy nuclei by hadrons and nuclei

International Nuclear Information System (INIS)

Tolstov, K.D.

1980-01-01

The total disintegration is considered of Ag and Pb nuclei and 4 He, 12 C nuclei With a momentum of 4.5 GeV/c per nucleon. It is shown that nucleons are mainly emitted, and there is no residual nUcleus the mass of which is comparable to that of the primary nucleus. The probability of total nucleus disintegration is considered as a function of projectile energy and the mass. The multiplicity, energy and emission angle of particles are considerred as well. It is shown that the density of nuclear matter in the overlap zone of colliding nuclei exceeds the usual one by a factor of approximately 4. A comparison is made with interaction models. A conclusion is drawn of the collective interaction mechanism (perhaps, of the shock wave type) of particle ejection from the target nucleus at the first stage of interaction and of explosive decay of the residual nucleus at the next one

Embryonic effects transmitted by male mice irradiated with 512 MeV/u 56Fe nuclei

International Nuclear Information System (INIS)

Wiley, L.M.; Van Beek, M.E.A.B.; Raabe, O.G.

1994-01-01

High-energy, high-charge nuclei may contribute substantially to the yearly equivalent dose in space flight from galactic cosmic radiation (GCR) at solar minimum. The largest single heavy-ion component is 56 Fe. We used the mouse embryo chimera assay to test 512 MeV/u 56 Fe nuclei for effects on the rate of proliferation of embryonic cells transmitted by sperm from irradiated mice. Male CD1 mice were acutely irradiated with 0.01, 0.05, or 0.1 Gy (LET, 184 keV/μm; fluence, 3.5 x 10 4 -3.3 x 10 5 nuclei/cm 2 ; average dose rate, 0.02 Gy/min) at the Lawrence Berkeley Laboratory BEVATRON/BEVALAC Facility in Berkeley, CA. Irradiated males were bred weekly for 7 weeks to nonirradiated females and their four-cell embryos were paired with control embryos, forming aggregation chimeras. After 30-35 h of culture, chimeras were dissociated to obtain open-quotes proliferation ratiosclose quotes (number of cells contributed by the embryo from the irradiated male/total number of cells in the chimera). Significant dose-dependent decreases in proliferation ratios were obtained across all three dose groups for postirradiation week 2 (P 56 Fe nuclei. However, up to 47% of sperm during postirradiation weeks 1 and 2 transmitted proliferation ratios that were at or below one standard deviation from control mean proliferation ratios. 26 refs., 4 figs., 10 tabs

Creatine supplementation augments the increase in satellite cell and myonuclei number in human skeletal muscle induced by strength training

DEFF Research Database (Denmark)

Olsen, Steen; Aagaard, Per; Kadi, Fawzi

2006-01-01

The present study investigated the influence of creatine and protein supplementation on satellite cell frequency and number of myonuclei in human skeletal muscle during 16 weeks of heavy-resistance training. In a double-blinded design 32 healthy, male subjects (19-26 years) were assigned to stren......The present study investigated the influence of creatine and protein supplementation on satellite cell frequency and number of myonuclei in human skeletal muscle during 16 weeks of heavy-resistance training. In a double-blinded design 32 healthy, male subjects (19-26 years) were assigned...

High-spin excitations of atomic nuclei

International Nuclear Information System (INIS)

Xu Furong; National Laboratory of Heavy Ion Physics, Lanzhou; Chinese Academy of Sciences, Beijing

2004-01-01

The authors used the cranking shell model to investigate the high-spin motions and structures of atomic nuclei. The authors focus the collective rotations of the A∼50, 80 and 110 nuclei. The A∼50 calculations show complicated g spectroscopy, which can have significant vibration effects. The A≅80 N≅Z nuclei show rich shape coexistence with prolate and oblate rotational bands. The A≅110 nuclei near the r-process path can have well-deformed oblate shapes that become yrast and more stable with increasing rotational frequency. As another important investigation, the authors used the configuration-constrained adiabatic method to calculate the multi-quasiparticle high-K states in the A∼130, 180 and superheavy regions. The calculations show significant shape polarizations due to quasi-particle excitations for soft nuclei, which should be considered in the investigations of high-K states. The authors predicted some important high-K isomers, e.g., the 8 - isomers in the unstable nuclei of 140 Dy and 188 Pb, which have been confirmed in experiments. In superheavy nuclei, our calculations show systematic existence of high-K states. The high-K excitations can increase the productions of synthesis and the survival probabilities of superheavy nuclei. (authors)

Methods to isolate a large amount of generative cells, sperm cells and vegetative nuclei from tomato pollen for omics analysis

Directory of Open Access Journals (Sweden)

Yunlong eLu

2015-06-01

Full Text Available The development of sperm cells from microspores involves a set of finely regulated molecular and cellular events and the coordination of these events. The mechanisms underlying these events and their interconnections remain a major challenge. Systems analysis of genome-wide molecular networks and functional modules with high-throughput omics approaches is crucial for understanding the mechanisms; however, this study is hindered because of the difficulty in isolating a large amount of cells of different types, especially generative cells (GCs, from the pollen. Here, we optimized the conditions of tomato pollen germination and pollen tube growth to allow for long-term growth of pollen tubes in vitro with sperm cells (SCs generated in the tube. Using this culture system, we developed methods for isolating GCs, SCs and vegetative-cell nuclei (VN from just-germinated tomato pollen grains and growing pollen tubes and their purification by Percoll density gradient centrifugation. The purity and viability of isolated GCs and SCs were confirmed by microscopy examination and fluorescein diacetate staining, respectively, and the integrity of VN was confirmed by propidium iodide staining. We could obtain about 1.5 million GCs and 2.0 million SCs each from 180 mg initiated pollen grains, and 10 million VN from 270 mg initiated pollen grains germinated in vitro in each experiment. These methods provide the necessary preconditions for systematic biology studies of SC development and differentiation in higher plants.

Methods to isolate a large amount of generative cells, sperm cells and vegetative nuclei from tomato pollen for "omics" analysis.

Science.gov (United States)

Lu, Yunlong; Wei, Liqin; Wang, Tai

2015-01-01

The development of sperm cells (SCs) from microspores involves a set of finely regulated molecular and cellular events and the coordination of these events. The mechanisms underlying these events and their interconnections remain a major challenge. Systems analysis of genome-wide molecular networks and functional modules with high-throughput "omics" approaches is crucial for understanding the mechanisms; however, this study is hindered because of the difficulty in isolating a large amount of cells of different types, especially generative cells (GCs), from the pollen. Here, we optimized the conditions of tomato pollen germination and pollen tube growth to allow for long-term growth of pollen tubes in vitro with SCs generated in the tube. Using this culture system, we developed methods for isolating GCs, SCs and vegetative cell nuclei (VN) from just-germinated tomato pollen grains and growing pollen tubes and their purification by Percoll density gradient centrifugation. The purity and viability of isolated GCs and SCs were confirmed by microscopy examination and fluorescein diacetate staining, respectively, and the integrity of VN was confirmed by propidium iodide staining. We could obtain about 1.5 million GCs and 2.0 million SCs each from 180 mg initiated pollen grains, and 10 million VN from 270 mg initiated pollen grains germinated in vitro in each experiment. These methods provide the necessary preconditions for systematic biology studies of SC development and differentiation in higher plants.

The shape of nuclei

International Nuclear Information System (INIS)

Mackintosh, R.S.

1977-01-01

For the class of nuclei which are 'strongly deformed' it is possible to introduce the idea of an empirically measurable static nuclear shape. The limitations of this concept as applied to nuclei (fundamentally quantum-mechanical objects) are discussed. These are basically the limitations of the rotational model which must be introduced in order to define and measure nuclear shape. A unified discussion of the ways in which the shape has been parametrized is given with emphasis on the fact that different parametrizations correspond to different nuclear structures. Accounts of the various theoretical procedures for calculating nuclear shapes and of the interaction between nuclear shapes and nuclear spectroscopy are given. A coherent account of a large subset of nuclei (strongly deformed nuclei) can be given by means of a model in which the concept of nuclear shape plays a central role. (author)

Structure of Warm Nuclei

International Nuclear Information System (INIS)

Aaberg, S.; Uhrenholt, H.

2009-01-01

We study the structure of nuclei in the energy region between the ground state and the neutron separation energy, here called warm nuclei. The onset of chaos in the nucleus as excitation energy is increased is briefly reviewed. Chaos implies fluctuations of energies and wave functions qualitatively the same for all chaotic nuclei. On the other hand, large structure effects are seen, e.g. in the level-density function at same excitation energies. A microscopic model for the level density is reviewed and we discuss effects on structure of the total level-density function, parity enhancement, and the spin distribution function. Comparisons to data are performed at the neutron separation energy for all observed nuclei, and structure of the level-density function for a few measured cases. The role of structure effects in the level-density function for fission dynamics is exemplified.

Dynamic polarisation of nuclei

International Nuclear Information System (INIS)

Borghini, M.; Abragam, A.

1961-01-01

In magnetic fields of about 13000 gauss, at a temperature of 1.5 deg. K, in samples of about 2 mm 3 , we have obtained by the 'solid effect' (application of a magnetic field at an appropriate frequency around 35000 MHz), nuclear polarizations /I of a few percent: 19 per cent for hydrogen nuclei in single crystals of La 2 Mg 3 (NO 3 ) 12 , 24H 2 O; 5 per cent for hydrogen nuclei in polystyrene; 6 per cent for fluorine nuclei in single crystals of LiF. (author) [fr

Solar power satellites: Commercialization and socio-economic impacts

International Nuclear Information System (INIS)

Storelli, V.

1993-01-01

Commercialization prospects for solar power satellites are assessed with reference to their possible impacts on the viability of the fossil fuel market and on international energy and environmental policies. The technical aspects which are examined include: solar panel sizing in relation to solar cell efficiency; the development of point-contact solar cell technology; the feasibility of the use of lunar materials; microwave transmission from the moon; optimum satellite positioning; the use of robots for in-space satellite assembly; satellite transmitted power for hydrogen production and storage; marketable product estimated development time

Space Solar Power: Satellite Concepts

Science.gov (United States)

Little, Frank E.

1999-01-01

Space Solar Power (SSP) applies broadly to the use of solar power for space related applications. The thrust of the NASA SSP initiative is to develop concepts and demonstrate technology for applying space solar power to NASA missions. Providing power from satellites in space via wireless transmission to a receiving station either on earth, another celestial body or a second satellite is one goal of the SSP initiative. The sandwich design is a satellite design in which the microwave transmitting array is the front face of a thin disk and the back of the disk is populated with solar cells, with the microwave electronics in between. The transmitter remains aimed at the earth in geostationary orbit while a system of mirrors directs sunlight to the photovoltaic cells, regardless of the satellite's orientation to the sun. The primary advantage of the sandwich design is it eliminates the need for a massive and complex electric power management and distribution system for the satellite. However, it requires a complex system for focusing sunlight onto the photovoltaic cells. In addition, positioning the photovoltaic array directly behind the transmitting array power conversion electronics will create a thermal management challenge. This project focused on developing designs and finding emerging technology to meet the challenges of solar tracking, a concentrating mirror system including materials and coatings, improved photovoltaic materials and thermal management.

Optimized High Temperature PEM Fuel Cell & High Pressure PEM Electrolyser for Regenerative Fuel Cell Systems in GEO Telecommunication Satellites

Directory of Open Access Journals (Sweden)

Farnes Jarle

2017-01-01

Full Text Available Next generation telecommunication satellites will demand increasingly more power. Power levels up to 50 kW are foreseen for the next decades. Battery technology that can sustain up to 50 kW for eclipse lengths of up to 72 minutes will represent a major impact on the total mass of the satellite, even with new Li-ion battery technologies. Regenerative fuel cell systems (RFCS were identified years ago as a possible alternative to rechargeable batteries. CMR Prototech has investigated this technology in a series of projects initiated by ESA focusing on both the essential fuel cell technology, demonstration of cycle performance of a RFCS, corresponding to 15 years in orbit, as well as the very important reactants storage systems. In the last two years the development has been focused towards optimising the key elements of the RFCS; the HTPEM fuel cell and the High Pressure PEM electrolyser. In these ESA activities the main target has been to optimise the design by reducing the mass and at the same time improve the performance, thus increasing the specific energy. This paper will present the latest development, including the main results, showing that significant steps have been taken to increase TRL on these key components.

Diffraction scattering and disintegration of 3He nuclei by atomic nuclei

International Nuclear Information System (INIS)

Koval'chuk, V.I.

2006-01-01

Within diffraction model framework a method of cross sections calculation for scattering and disintegration of weakly-bounded two-clustered nuclei by nuclei when both of its clusters are changed has been proposed. The experimental elastic scattering cross sections of 3 He by 40 Ca, 90 Zr and coincidence spectra of disintegration products from 28 Si( 3 He,dp) have been described

Neutron rich nuclei

International Nuclear Information System (INIS)

Foucher, R.

1979-01-01

If some β - emitters are particularly interesting to study in light, medium, and heavy nuclei, another (and also) difficult problem is to know systematically the properties of these neutron rich nuclei far from the stability line. A review of some of their characteristics is presented. How far is it possible to be objective in the interpretation of data is questioned and implications are discussed

Automated recognition of cell phenotypes in histology images based on membrane- and nuclei-targeting biomarkers

International Nuclear Information System (INIS)

Karaçalı, Bilge; Vamvakidou, Alexandra P; Tözeren, Aydın

2007-01-01

Three-dimensional in vitro culture of cancer cells are used to predict the effects of prospective anti-cancer drugs in vivo. In this study, we present an automated image analysis protocol for detailed morphological protein marker profiling of tumoroid cross section images. Histologic cross sections of breast tumoroids developed in co-culture suspensions of breast cancer cell lines, stained for E-cadherin and progesterone receptor, were digitized and pixels in these images were classified into five categories using k-means clustering. Automated segmentation was used to identify image regions composed of cells expressing a given biomarker. Synthesized images were created to check the accuracy of the image processing system. Accuracy of automated segmentation was over 95% in identifying regions of interest in synthesized images. Image analysis of adjacent histology slides stained, respectively, for Ecad and PR, accurately predicted regions of different cell phenotypes. Image analysis of tumoroid cross sections from different tumoroids obtained under the same co-culture conditions indicated the variation of cellular composition from one tumoroid to another. Variations in the compositions of cross sections obtained from the same tumoroid were established by parallel analysis of Ecad and PR-stained cross section images. Proposed image analysis methods offer standardized high throughput profiling of molecular anatomy of tumoroids based on both membrane and nuclei markers that is suitable to rapid large scale investigations of anti-cancer compounds for drug development

Baryon resonances in nuclei

International Nuclear Information System (INIS)

Arenhoevel, H.

1977-01-01

The field of baryon resonances in nuclei is reviewed. Theoretical developments and experimental evidence as well are discussed. Special emphasis is laid on electromagnetic processes for the two nucleon system. Some aspects of real isobars in nuclei are touched upon. (orig.) [de

Localization Microscopy Analyses of MRE11 Clusters in 3D-Conserved Cell Nuclei of Different Cell Lines.

Science.gov (United States)

Eryilmaz, Marion; Schmitt, Eberhard; Krufczik, Matthias; Theda, Franziska; Lee, Jin-Ho; Cremer, Christoph; Bestvater, Felix; Schaufler, Wladimir; Hausmann, Michael; Hildenbrand, Georg

2018-01-22

In radiation biophysics, it is a subject of nowadays research to investigate DNA strand break repair in detail after damage induction by ionizing radiation. It is a subject of debate as to what makes up the cell's decision to use a certain repair pathway and how the repair machinery recruited in repair foci is spatially and temporarily organized. Single-molecule localization microscopy (SMLM) allows super-resolution analysis by precise localization of single fluorescent molecule tags, resulting in nuclear structure analysis with a spatial resolution in the 10 nm regime. Here, we used SMLM to study MRE11 foci. MRE11 is one of three proteins involved in the MRN-complex (MRE11-RAD50-NBS1 complex), a prominent DNA strand resection and broken end bridging component involved in homologous recombination repair (HRR) and alternative non-homologous end joining (a-NHEJ). We analyzed the spatial arrangements of antibody-labelled MRE11 proteins in the nuclei of a breast cancer and a skin fibroblast cell line along a time-course of repair (up to 48 h) after irradiation with a dose of 2 Gy. Different kinetics for cluster formation and relaxation were determined. Changes in the internal nano-scaled structure of the clusters were quantified and compared between the two cell types. The results indicate a cell type-dependent DNA damage response concerning MRE11 recruitment and cluster formation. The MRE11 data were compared to H2AX phosphorylation detected by γH2AX molecule distribution. These data suggested modulations of MRE11 signal frequencies that were not directly correlated to DNA damage induction. The application of SMLM in radiation biophysics offers new possibilities to investigate spatial foci organization after DNA damaging and during subsequent repair.

Ice nuclei in marine air: biogenic particles or dust?

Directory of Open Access Journals (Sweden)

S. M. Burrows

2013-01-01

Full Text Available Ice nuclei impact clouds, but their sources and distribution in the atmosphere are still not well known. Particularly little attention has been paid to IN sources in marine environments, although evidence from field studies suggests that IN populations in remote marine regions may be dominated by primary biogenic particles associated with sea spray. In this exploratory model study, we aim to bring attention to this long-neglected topic and identify promising target regions for future field campaigns. We assess the likely global distribution of marine biogenic ice nuclei using a combination of historical observations, satellite data and model output. By comparing simulated marine biogenic immersion IN distributions and dust immersion IN distributions, we predict strong regional differences in the importance of marine biogenic IN relative to dust IN. Our analysis suggests that marine biogenic IN are most likely to play a dominant role in determining IN concentrations in near-surface-air over the Southern Ocean, so future field campaigns aimed at investigating marine biogenic IN should target that region. Climate-related changes in the abundance and emission of biogenic marine IN could affect marine cloud properties, thereby introducing previously unconsidered feedbacks that influence the hydrological cycle and the Earth's energy balance. Furthermore, marine biogenic IN may be an important aspect to consider in proposals for marine cloud brightening by artificial sea spray production.

Long-term insulin-like growth factor-I expression in skeletal muscles attenuates the enhanced in vitro proliferation ability of the resident satellite cells in transgenic mice

Science.gov (United States)

Chakravarthy, M. V.; Fiorotto, M. L.; Schwartz, R. J.; Booth, F. W.

2001-01-01

Insulin-like growth factor-I (IGF-I) overexpression for 1-month in mouse skeletal muscle increases satellite cell proliferation potential. However, it is unknown whether this beneficial enhancement by IGF-I expression would persist over a longer-term duration in aged mice. This is an important issue to address if a prolonged course of IGF-I is to be used clinically in muscle-wasting conditions where satellite cells may become limiting. Using the IGF-I transgenic (IGF-I Tg) mouse that selectively expresses the IGF-I transgene in striated muscles, we found that 18-months of continuous IGF-I overexpression led to a loss in the enhanced in vitro proliferative capacity of satellite cells from Tg skeletal muscles. Also 18-month-old IGF-I Tg satellite cells lost the enhanced BrdU incorporation, greater pRb and Akt phosphorylations, and decreased p27(Kip1) levels initially observed in cells from 1-month-old IGF-I Tg mice. The levels of those biochemical markers reverted to similar values seen in the 18-months WT littermates. These findings, therefore, suggest that there is no further beneficial effect on enhancing satellite cell proliferation ability with persistent long-term expression of IGF-I in skeletal muscles of these transgenic mice.

Nucleons in nuclei, however

International Nuclear Information System (INIS)

Grange, P.; Mathiot, J.F.; Roy-Stephan, M.; Frascaria, R.; Gales, S.

1990-01-01

The topics presented at the 1989 Joliot-Curie Lectures are reported. Two main subjects were retained: a simplified description of the N-body motion of particles in the quasi-particle configuration; study of the dynamics of nuclear components which are not described by nucleons in their ground state. The following themes were presented: quasiparticles and the Green functions, relativistic aspects of the quasiparticle concept, the dimensions of nucleons in the nuclei and the EMC effect, quarks and gluons in the nuclei, the delta in the nuclei, the strangeness, quasiparticles far from the Fermi sea, diffusion of electrons, stellar evolution and nucleosynthesis [fr

Reflection asymmetric shapes in nuclei

International Nuclear Information System (INIS)

Ahmad, I.; Carpenter, M.P.; Emling, H.

1989-01-01

Experimental data show that there is no even-even nucleus with a reflection asymmetric shape in its ground state. Maximum octupole- octupole correlations occur in nuclei in the mass 224 (N∼134, Z∼88) region. Parity doublets, which are the characteristic signature of octupole deformation, have been observed in several odd mass Ra, Ac and Pa nuclei. Intertwined negative and positive parity levels have been observed in several even-even Ra and Th nuclei above spin ∼8ℎ. In both cases, the opposite parity states are connected by fast El transitions. In some medium-mass nuclei intertwined negative and positive parity levels have also been observed above spin ∼7ℎ. The nuclei which exhibit octupole deformation in this mass region are 144 Ba, 146 Ba and 146 Ce; 142 Ba, 148 Ce, 150 Ce and 142 Xe do not show these characteristics. No case of parity doublet has been observed in the mass 144 region. 32 refs., 16 figs., 1 tab

Solid state NMR, basic theory and recent progress for quadrupole nuclei with half-integer spin

International Nuclear Information System (INIS)

Dieter, F.

1998-01-01

This review describes the basic theory and some recently developed techniques for the study of quadrupole nuclei with half integer spins in powder materials. The latter is connected to the introduction of the double rotation (DOR) by A. Samoson et al. (1) and to the introduction of the multiple quantum magic-angle spinning (MQ MAS) technique by L. Frydman et. al. (2). For integer spins, especially the solid-state deuterium magnetic resonance, we refer to the review of G.L. Hoatson and R.L. Vold: '' 2 H-NMR Spectroscopy of Solids and Liquid Crystals'' (3). For single crystals we refer to O. Kanert and M. Mehring: ''Static quadrupole effects in disordered cubic solids''(4) and we would like also to mention the ''classic'' review of M.H. Cohen and F. Reif: ''Quadrupole effects in NMR studies of solids'' (5). Some more recent reviews in the field under study are D. Freude and J. Haase ''Quadrupole effects in solid-state NMR'' (6). Ch. Jager: ''Satellite Transition Spectroscopy of Quadrupolar Nuclei'' (7) and B.F. Chmelka and J.W. Zwanziger: ''Solid State NMR Line Narrowing Methods for Quadrupolar Nuclei - Double Rotation and Dynamic-Angle Spinning'' (8). A survey of nuclear quadrupole frequency data published before the end of 1982 is given by H. Chihara and N. Nakamura in Landolt-Bornstein, Vol. 20 (9). Values of the chemical shift of quadrupole nuclei in solids can be found in books such as ''Multinuclear NMR'' edited by J. Mason (10). In section 9 of ref (6) some electric field gradient and chemical shift data published from 1983 to 1992 for the most studied quadrupole nuclei sup 27 Al, sup 23 Na, and sup 17 O are given

Precision measurement of the mass difference between light nuclei and anti-nuclei

CERN Document Server

Adam, Jaroslav; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahmed, Ijaz; Ahn, Sang Un; Aimo, Ilaria; Aiola, Salvatore; Ajaz, Muhammad; Akindinov, Alexander; Alam, Sk Noor; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Armesto Perez, Nestor; Arnaldi, Roberta; Aronsson, Tomas; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Ball, Markus; Baltasar Dos Santos Pedrosa, Fernando; Baral, Rama Chandra; Barbano, Anastasia Maria; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartalini, Paolo; Bartke, Jerzy Gustaw; Bartsch, Esther; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batista Camejo, Arianna; Batyunya, Boris; Batzing, Paul Christoph; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bello Martinez, Hector; Bellwied, Rene; Belmont Iii, Ronald John; Belmont Moreno, Ernesto; Belyaev, Vladimir; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhat, Inayat Rasool; Bhati, Ashok Kumar; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Biswas, Saikat; Bjelogrlic, Sandro; Blanco, Fernando; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Boldizsar, Laszlo; Bombara, Marek; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Borri, Marcello; Bossu, Francesco; Botje, Michiel; Botta, Elena; Boettger, Stefan; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Broker, Theo Alexander; Browning, Tyler Allen; Broz, Michal; Brucken, Erik Jens; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Buxton, Jesse Thomas; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calero Diaz, Liliet; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Carena, Francesco; Carena, Wisla; Castillo Castellanos, Javier Ernesto; Castro, Andrew John; Casula, Ester Anna Rita; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Chartier, Marielle; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chelnokov, Volodymyr; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Chochula, Peter; Choi, Kyungeon; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Connors, Megan Elizabeth; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortes Maldonado, Ismael; Cortese, Pietro; Cosentino, Mauro Rogerio; Costa, Filippo; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dahms, Torsten; Dainese, Andrea; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; De Caro, Annalisa; De Cataldo, Giacinto; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; Deisting, Alexander; Deloff, Andrzej; Denes, Ervin Sandor; D'Erasmo, Ginevra; Di Bari, Domenico; Di Mauro, Antonio; Di Nezza, Pasquale; Diaz Corchero, Miguel Angel; Dietel, Thomas; Dillenseger, Pascal; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni; Domenicis Gimenez, Diogenes; Donigus, Benjamin; Dordic, Olja; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent; Dupieux, Pascal; Ehlers Iii, Raymond James; Elia, Domenico; Engel, Heiko; Erazmus, Barbara Ewa; Erhardt, Filip; Eschweiler, Dominic; Espagnon, Bruno; Estienne, Magali Danielle; Esumi, Shinichi; Evans, David; Evdokimov, Sergey; Eyyubova, Gyulnara; Fabbietti, Laura; Fabris, Daniela; Faivre, Julien; Fantoni, Alessandra; Fasel, Markus; Feldkamp, Linus; Felea, Daniel; Feliciello, Alessandro; Feofilov, Grigorii; Ferencei, Jozef; Fernandez Tellez, Arturo; Gonzalez Ferreiro, Elena; Ferretti, Alessandro; Festanti, Andrea; Figiel, Jan; Araujo Silva Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Fleck, Martin Gabriel; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Francescon, Andrea; Frankenfeld, Ulrich Michael; Fuchs, Ulrich; Furget, Christophe; Furs, Artur; Fusco Girard, Mario; Gaardhoeje, Jens Joergen; Gagliardi, Martino; Gago Medina, Alberto Martin; Gallio, Mauro; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Gao, Chaosong; Garabatos Cuadrado, Jose; Garcia-Solis, Edmundo Javier; Gargiulo, Corrado; Gasik, Piotr Jan; Germain, Marie; Gheata, Andrei George; Gheata, Mihaela; Ghosh, Premomoy; Ghosh, Sanjay Kumar; Gianotti, Paola; Giubellino, Paolo; Giubilato, Piero; Gladysz-Dziadus, Ewa; Glassel, Peter; Gomez Ramirez, Andres; Gonzalez Zamora, Pedro; Gorbunov, Sergey; Gorlich, Lidia Maria; Gotovac, Sven; Grabski, Varlen; Graczykowski, Lukasz Kamil; Grelli, Alessandro; Grigoras, Alina Gabriela; Grigoras, Costin; Grigoryev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grynyov, Borys; Grion, Nevio; Grosse-Oetringhaus, Jan Fiete; Grossiord, Jean-Yves; Grosso, Raffaele; Guber, Fedor; Guernane, Rachid; Guerzoni, Barbara; Gulbrandsen, Kristjan Herlache; Gulkanyan, Hrant; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Haake, Rudiger; Haaland, Oystein Senneset; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Hanratty, Luke David; Hansen, Alexander; Harris, John William; Hartmann, Helvi; Harton, Austin Vincent; Hatzifotiadou, Despina; Hayashi, Shinichi; Heckel, Stefan Thomas; Heide, Markus Ansgar; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Hess, Benjamin Andreas; Hetland, Kristin Fanebust; Hilden, Timo Eero; Hillemanns, Hartmut; Hippolyte, Boris; Hristov, Peter Zahariev; Huang, Meidana; Humanic, Thomas; Hussain, Nur; Hussain, Tahir; Hutter, Dirk; Hwang, Dae Sung; Ilkaev, Radiy; Ilkiv, Iryna; Inaba, Motoi; Ionita, Costin; Ippolitov, Mikhail; Irfan, Muhammad; Ivanov, Marian; Ivanov, Vladimir; Izucheev, Vladimir; Jacobs, Peter Martin; Jahnke, Cristiane; Jang, Haeng Jin; Janik, Malgorzata Anna; Pahula Hewage, Sandun; Jena, Chitrasen; Jena, Satyajit; Jimenez Bustamante, Raul Tonatiuh; Jones, Peter Graham; Jung, Hyungtaik; Jusko, Anton; Kalinak, Peter; Kalweit, Alexander Philipp; Kamin, Jason Adrian; Kang, Ju Hwan; Kaplin, Vladimir; Kar, Somnath; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karpechev, Evgeny; Kebschull, Udo Wolfgang; Keidel, Ralf; Keijdener, Darius Laurens; Keil, Markus; Khan, Kamal; Khan, Mohammed Mohisin; Khan, Palash; Khan, Shuaib Ahmad; Khanzadeev, Alexei; Kharlov, Yury; Kileng, Bjarte; Kim, Beomkyu; Kim, Do Won; Kim, Dong Jo; Kim, Hyeonjoong; Kim, Jinsook; Kim, Mimae; Kim, Minwoo; Kim, Se Yong; Kim, Taesoo; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Kiss, Gabor; Klay, Jennifer Lynn; Klein, Carsten; Klein, Jochen; Klein-Boesing, Christian; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Kobayashi, Taiyo; Kobdaj, Chinorat; Kofarago, Monika; Kohler, Markus Konrad; Kollegger, Thorsten; Kolozhvari, Anatoly; Kondratev, Valerii; Kondratyeva, Natalia; Kondratyuk, Evgeny; Konevskikh, Artem; Kouzinopoulos, Charalampos; Kovalenko, Vladimir; Kowalski, Marek; Kox, Serge; Koyithatta Meethaleveedu, Greeshma; Kral, Jiri; Kralik, Ivan; Kravcakova, Adela; Krelina, Michal; Kretz, Matthias; Krivda, Marian; Krizek, Filip; Kryshen, Evgeny; Krzewicki, Mikolaj; Kubera, Andrew Michael; Kucera, Vit; Kucheryaev, Yury; Kugathasan, Thanushan; Kuhn, Christian Claude; Kuijer, Paulus Gerardus; Kulakov, Igor; Kumar, Jitendra; Lokesh, Kumar; Kurashvili, Podist; Kurepin, Alexander; Kurepin, Alexey; Kuryakin, Alexey; Kushpil, Svetlana; Kweon, Min Jung; Kwon, Youngil; La Pointe, Sarah Louise; La Rocca, Paola; Lagana Fernandes, Caio; Lakomov, Igor; Langoy, Rune; Lara Martinez, Camilo Ernesto; Lardeux, Antoine Xavier; Lattuca, Alessandra; Laudi, Elisa; Lea, Ramona; Leardini, Lucia; Lee, Graham Richard; Lee, Seongjoo; Legrand, Iosif; Lehnert, Joerg Walter; Lemmon, Roy Crawford; Lenti, Vito; Leogrande, Emilia; Leon Monzon, Ildefonso; Leoncino, Marco; Levai, Peter; Li, Shuang; Li, Xiaomei; Lien, Jorgen Andre; Lietava, Roman; Lindal, Svein; Lindenstruth, Volker; Lippmann, Christian; Lisa, Michael Annan; Ljunggren, Hans Martin; Lodato, Davide Francesco; Lonne, Per-Ivar; Loggins, Vera Renee; Loginov, Vitaly; Loizides, Constantinos; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lowe, Andrew John; Lu, Xianguo; Luettig, Philipp Johannes; Lunardon, Marcello; Luparello, Grazia; Maevskaya, Alla; Mager, Magnus; Mahajan, Sanjay; Mahmood, Sohail Musa; Maire, Antonin; Majka, Richard Daniel; Malaev, Mikhail; Maldonado Cervantes, Ivonne Alicia; Malinina, Liudmila; Mal'Kevich, Dmitry; Malzacher, Peter; Mamonov, Alexander; Manceau, Loic Henri Antoine; Manko, Vladislav; Manso, Franck; Manzari, Vito; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Margutti, Jacopo; Marin, Ana Maria; Markert, Christina; Marquard, Marco; Martashvili, Irakli; Martin, Nicole Alice; Martin Blanco, Javier; Martinengo, Paolo; Martinez Hernandez, Mario Ivan; Martinez-Garcia, Gines; Martinez Pedreira, Miguel; Martynov, Yevgen; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Massacrier, Laure Marie; Mastroserio, Annalisa; Matyja, Adam Tomasz; Mayer, Christoph; Mazer, Joel Anthony; Mazzoni, Alessandra Maria; Mcdonald, Daniel; Meddi, Franco; Menchaca-Rocha, Arturo Alejandro; Meninno, Elisa; Mercado-Perez, Jorge; Meres, Michal; Miake, Yasuo; Mieskolainen, Matti Mikael; Mikhaylov, Konstantin; Milano, Leonardo; Milosevic, Jovan; Minervini, Lazzaro Manlio; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz Czeslaw; Mitra, Jubin; Mitu, Ciprian Mihai; Mohammadi, Naghmeh; Mohanty, Bedangadas; Molnar, Levente; Montano Zetina, Luis Manuel; Montes Prado, Esther; Morando, Maurizio; Moreira De Godoy, Denise Aparecida; Moretto, Sandra; Morreale, Astrid; Morsch, Andreas; Muccifora, Valeria; Mudnic, Eugen; Muhlheim, Daniel Michael; Muhuri, Sanjib; Mukherjee, Maitreyee; Muller, Hans; Mulligan, James Declan; Gameiro Munhoz, Marcelo; Murray, Sean; Musa, Luciano; Musinsky, Jan; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Naru, Muhammad Umair; Nattrass, Christine; Nayak, Kishora; Nayak, Tapan Kumar; Nazarenko, Sergey; Nedosekin, Alexander; Nellen, Lukas; Ng, Fabian; Nicassio, Maria; Niculescu, Mihai; Niedziela, Jeremi; Nielsen, Borge Svane; Nikolaev, Sergey; Nikulin, Sergey; Nikulin, Vladimir; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Norman, Jaime; Nyanin, Alexander; Nystrand, Joakim Ingemar; Oeschler, Helmut Oskar; Oh, Saehanseul; Oh, Sun Kun; Ohlson, Alice Elisabeth; Okatan, Ali; Okubo, Tsubasa; Olah, Laszlo; Oleniacz, Janusz; Oliveira Da Silva, Antonio Carlos; Oliver, Michael Henry; Onderwaater, Jacobus; Oppedisano, Chiara; Ortiz Velasquez, Antonio; Oskarsson, Anders Nils Erik; Otwinowski, Jacek Tomasz; Oyama, Ken; Ozdemir, Mahmut; Pachmayer, Yvonne Chiara; Pagano, Paola; Paic, Guy; Pajares Vales, Carlos; Pal, Susanta Kumar; Pan, Jinjin; Pandey, Ashutosh Kumar; Pant, Divyash; Papikyan, Vardanush; Pappalardo, Giuseppe; Pareek, Pooja; Park, Woojin; Parmar, Sonia; Passfeld, Annika; Paticchio, Vincenzo; Paul, Biswarup; Pawlak, Tomasz Jan; Peitzmann, Thomas; Pereira Da Costa, Hugo Denis Antonio; Pereira De Oliveira Filho, Elienos; Peresunko, Dmitry Yurevich; Perez Lara, Carlos Eugenio; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petrov, Viacheslav; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Pikna, Miroslav; Pillot, Philippe; Pinazza, Ombretta; Pinsky, Lawrence; Piyarathna, Danthasinghe; Ploskon, Mateusz Andrzej; Planinic, Mirko; Pluta, Jan Marian; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Polishchuk, Boris; Poljak, Nikola; Poonsawat, Wanchaloem; Pop, Amalia; Porteboeuf, Sarah Julie; Porter, R Jefferson; Pospisil, Jan; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puccio, Maximiliano; Puddu, Giovanna; Pujahari, Prabhat Ranjan; Punin, Valery; Putschke, Jorn Henning; Qvigstad, Henrik; Rachevski, Alexandre; Raha, Sibaji; Rajput, Sonia; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Razazi, Vahedeh; Read, Kenneth Francis; Real, Jean-Sebastien; Redlich, Krzysztof; Reed, Rosi Jan; Rehman, Attiq Ur; Reichelt, Patrick Simon; Reicher, Martijn; Reidt, Felix; Ren, Xiaowen; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; Rettig, Felix Vincenz; Revol, Jean-Pierre; Reygers, Klaus Johannes; Riabov, Viktor; Ricci, Renato Angelo; Richert, Tuva Ora Herenui; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Ristea, Catalin-Lucian; Rivetti, Angelo; Rocco, Elena; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roeed, Ketil; Rogochaya, Elena; Rohr, David Michael; Roehrich, Dieter; Romita, Rosa; Ronchetti, Federico; Ronflette, Lucile; Rosnet, Philippe; Rossi, Andrea; Roukoutakis, Filimon; Roy, Ankhi; Roy, Christelle Sophie; Roy, Pradip Kumar; Rubio Montero, Antonio Juan; Rui, Rinaldo; Russo, Riccardo; Ryabinkin, Evgeny; Ryabov, Yury; Rybicki, Andrzej; Sadovskiy, Sergey; Safarik, Karel; Sahlmuller, Baldo; Sahoo, Pragati; Sahoo, Raghunath; Sahoo, Sarita; Sahu, Pradip Kumar; Saini, Jogender; Sakai, Shingo; Saleh, Mohammad Ahmad; Salgado Lopez, Carlos Alberto; Salzwedel, Jai Samuel Nielsen; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sanchez Castro, Xitzel; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Santagati, Gianluca; Sarkar, Debojit; Scapparone, Eugenio; Scarlassara, Fernando; Scharenberg, Rolf Paul; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schuchmann, Simone; Schukraft, Jurgen; Schulc, Martin; Schuster, Tim Robin; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Rebecca Michelle; Seeder, Karin Soraya; Seger, Janet Elizabeth; Sekiguchi, Yuko; Selyuzhenkov, Ilya; Senosi, Kgotlaesele; Seo, Jeewon; Serradilla Rodriguez, Eulogio; Sevcenco, Adrian; Shabanov, Arseniy; Shabetai, Alexandre; Shadura, Oksana; Shahoyan, Ruben; Shangaraev, Artem; Sharma, Ankita; Sharma, Natasha; Shigaki, Kenta; Shtejer Diaz, Katherin; Sibiryak, Yury; Siddhanta, Sabyasachi; Sielewicz, Krzysztof Marek; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Silvestre, Catherine Micaela; Simatovic, Goran; Simonetti, Giuseppe; Singaraju, Rama Narayana; Singh, Ranbir; Singha, Subhash; Singhal, Vikas; Sinha, Bikash; Sarkar - Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Slupecki, Maciej; Smirnov, Nikolai; Snellings, Raimond; Snellman, Tomas Wilhelm; Soegaard, Carsten; Soltz, Ron Ariel; Song, Jihye; Song, Myunggeun; Song, Zixuan; Soramel, Francesca; Sorensen, Soren Pontoppidan; Spacek, Michal; Spiriti, Eleuterio; Sputowska, Iwona Anna; Spyropoulou-Stassinaki, Martha; Srivastava, Brijesh Kumar; Stachel, Johanna; Stan, Ionel; Stefanek, Grzegorz; Steinpreis, Matthew Donald; Stenlund, Evert Anders; Steyn, Gideon Francois; Stiller, Johannes Hendrik; Stocco, Diego; Strmen, Peter; Alarcon Do Passo Suaide, Alexandre; Sugitate, Toru; Suire, Christophe Pierre; Suleymanov, Mais Kazim Oglu; Sultanov, Rishat; Sumbera, Michal; Symons, Timothy; Szabo, Alexander; Szanto De Toledo, Alejandro; Szarka, Imrich; Szczepankiewicz, Adam; Szymanski, Maciej Pawel; Takahashi, Jun; Tanaka, Naoto; Tangaro, Marco-Antonio; Tapia Takaki, Daniel Jesus; Tarantola Peloni, Attilio; Tariq, Mohammad; Tarzila, Madalina-Gabriela; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terasaki, Kohei; Terrevoli, Cristina; Teyssier, Boris; Thaeder, Jochen Mathias; Thomas, Deepa; Tieulent, Raphael Noel; Timmins, Anthony Robert; Toia, Alberica; Trogolo, Stefano; Trubnikov, Victor; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vajzer, Michal; Vala, Martin; Valencia Palomo, Lizardo; Vallero, Sara; Van Der Maarel, Jasper; Van Hoorne, Jacobus Willem; Van Leeuwen, Marco; Vanat, Tomas; Vande Vyvre, Pierre; Varga, Dezso; Diozcora Vargas Trevino, Aurora; Vargyas, Marton; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vauthier, Astrid; Vechernin, Vladimir; Veen, Annelies Marianne; Veldhoen, Misha; Velure, Arild; Venaruzzo, Massimo; Vercellin, Ermanno; Vergara Limon, Sergio; Vernet, Renaud; Verweij, Marta; Vickovic, Linda; Viesti, Giuseppe; Viinikainen, Jussi Samuli; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Vinogradov, Alexander; Vinogradov, Leonid; Vinogradov, Yury; Virgili, Tiziano; Vislavicius, Vytautas; Viyogi, Yogendra; Vodopyanov, Alexander; Volkl, Martin Andreas; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; Von Haller, Barthelemy; Vorobyev, Ivan; Vranic, Danilo; Vrlakova, Janka; Vulpescu, Bogdan; Vyushin, Alexey; Wagner, Boris; Wagner, Jan; Wang, Hongkai; Wang, Mengliang; Wang, Yifei; Watanabe, Daisuke; Weber, Michael; Weber, Steffen Georg; Wessels, Johannes Peter; Westerhoff, Uwe; Wiechula, Jens; Wikne, Jon; Wilde, Martin Rudolf; Wilk, Grzegorz Andrzej; Wilkinson, Jeremy John; Williams, Crispin; Windelband, Bernd Stefan; Winn, Michael Andreas; Yaldo, Chris G; Yamaguchi, Yorito; Yang, Hongyan; Yang, Ping; Yano, Satoshi; Yasnopolskiy, Stanislav; Yin, Zhongbao; Yokoyama, Hiroki; Yoo, In-Kwon; Yurchenko, Volodymyr; Yushmanov, Igor; Zaborowska, Anna; Zaccolo, Valentina; Zaman, Ali; Zampolli, Chiara; Correia Zanoli, Henrique Jose; Zaporozhets, Sergey; Zarochentsev, Andrey; Zavada, Petr; Zavyalov, Nikolay; Zbroszczyk, Hanna Paulina; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Haitao; Zhang, Xiaoming; Zhang, Yonghong; Zhao, Chengxin; Zhigareva, Natalia; Zhou, Daicui; Zhou, You; Zhou, Zhuo; Zhu, Hongsheng; Zhu, Jianhui; Zhu, Xiangrong; Zichichi, Antonino; Zimmermann, Alice; Zimmermann, Markus Bernhard; Zinovjev, Gennady; Zyzak, Maksym

2015-08-17

The measurement of the mass differences for systems bound by the strong force has reached a very high precision with protons and anti-protons. The extension of such measurement from (anti-)baryons to (anti-)nuclei allows one to probe any difference in the interactions between nucleons and anti-nucleons encoded in the (anti-)nuclei masses. This force is a remnant of the underlying strong interaction among quarks and gluons and can be described by effective theories, but cannot yet be directly derived from quantum chromodynamics. Here we report a measurement of the difference between the ratios of the mass and charge of deuterons (d) and anti-deuterons ($\\bar{d}$), and $^{3}{\\rm He}$ and $^3\\overline{\\rm He}$ nuclei carried out with the ALICE (A Large Ion Collider Experiment) detector in Pb-Pb collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV. Our direct measurement of the mass-over-charge differences confirm CPT invariance to an unprecedented precision in the sector of light nuclei. This funda...

Neonatal Phosphate Nutrition Alters in Vivo and in Vitro Satellite Cell Activity in Pigs

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Chad H. Stahl

2012-05-01

Full Text Available Satellite cell activity is necessary for postnatal skeletal muscle growth. Severe phosphate (PO₄ deficiency can alter satellite cell activity, however the role of neonatal PO₄ nutrition on satellite cell biology remains obscure. Twenty-one piglets (1 day of age, 1.8 ± 0.2 kg BW were pair-fed liquid diets that were either PO₄ adequate (0.9% total P, supra-adequate (1.2% total P in PO₄ requirement or deficient (0.7% total P in PO₄ content for 12 days. Body weight was recorded daily and blood samples collected every 6 days. At day 12, pigs were orally dosed with BrdU and 12 h later, satellite cells were isolated. Satellite cells were also cultured in vitro for 7 days to determine if PO₄ nutrition alters their ability to proceed through their myogenic lineage. Dietary PO₄ deficiency resulted in reduced (P < 0.05 sera PO₄ and parathyroid hormone (PTH concentrations, while supra-adequate dietary PO₄ improved (P < 0.05 feed conversion efficiency as compared to the PO₄ adequate group. In vivo satellite cell proliferation was reduced (P < 0.05 among the PO₄ deficient pigs, and these cells had altered in vitro expression of markers of myogenic progression. Further work to better understand early nutritional programming of satellite cells and the potential benefits of emphasizing early PO₄ nutrition for future lean growth potential is warranted.

Satellite cell senescence underlies myopathy in a mouse model of limb-girdle muscular dystrophy 2H

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Kudryashova, Elena; Kramerova, Irina; Spencer, Melissa J.

2012-01-01

Mutations in the E3 ubiquitin ligase tripartite motif-containing 32 (TRIM32) are responsible for the disease limb-girdle muscular dystrophy 2H (LGMD2H). Previously, we generated Trim32 knockout mice (Trim32–/– mice) and showed that they display a myopathic phenotype accompanied by neurogenic features. Here, we used these mice to investigate the muscle-specific defects arising from the absence of TRIM32, which underlie the myopathic phenotype. Using 2 models of induced atrophy, we showed that TRIM32 is dispensable for muscle atrophy. Conversely, TRIM32 was necessary for muscle regrowth after atrophy. Furthermore, TRIM32-deficient primary myoblasts underwent premature senescence and impaired myogenesis due to accumulation of PIAS4, an E3 SUMO ligase and TRIM32 substrate that was previously shown to be associated with senescence. Premature senescence of myoblasts was also observed in vivo in an atrophy/regrowth model. Trim32–/– muscles had substantially fewer activated satellite cells, increased PIAS4 levels, and growth failure compared with wild-type muscles. Moreover, Trim32–/– muscles exhibited features of premature sarcopenia, such as selective type II fast fiber atrophy. These results imply that premature senescence of muscle satellite cells is an underlying pathogenic feature of LGMD2H and reveal what we believe to be a new mechanism of muscular dystrophy associated with reductions in available satellite cells and premature sarcopenia. PMID:22505452

Barriers in the energy of deformed nuclei

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V. Yu. Denisov

2014-06-01

Full Text Available Interaction energy between two nuclei considering to their deformations is studied. Coulomb and nuclear in-teraction energies, as well as the deformation energies of both nuclei, are taken into account at evaluation of the interaction energy. It is shown that the barrier related to the interaction energy of two nuclei depends on the de-formations and the height of the minimal barrier is evaluated. It is obtained that the heavier nucleus-nucleus sys-tems have large deformation values at the lowest barrier. The difference between the barrier between spherical nuclei and the lowest barrier between deformed nuclei increases with the mass and the charge of the interacting nuclei.

Skeletal muscle wasting with disuse atrophy is multi-dimensional: the response and interaction of myonuclei, satellite cells and signaling pathways

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Naomi Elisabeth Brooks

2014-03-01

Full Text Available Maintenance of skeletal muscle is essential for health and survival. There are marked losses of skeletal muscle mass as well as strength and physiological function under conditions of low mechanical load, such as space flight, as well as ground based models such as bed rest, immobilisation, disuse and various animal models. Disuse atrophy is caused by mechanical unloading of muscle and this leads to reduced muscle mass without fibre attrition. Skeletal muscle stem cells (satellite cells and myonuclei are integrally involved in skeletal muscle responses to environmental changes that induce atrophy. Myonuclear domain size is influenced differently in fast and slow twitch muscle, but also by different models of muscle wasting, a factor that is not yet understood. Although the myonuclear domain is 3-dimensional this is rarely considered. Apoptosis as a mechanism for myonuclear loss with atrophy is controversial, whereas cell death of satellite cells has not been considered. Molecular signals such as myostatin/SMAD pathway, MAFbx and MuRF1 E3 ligases of the ubiquitin proteasome pathway and IGF1-AKT-mTOR pathway are 3 distinctly different contributors to skeletal muscle protein adaptation to disuse. Molecular signalling pathways activated in muscle fibres by disuse are rarely considered within satellite cells themselves despite similar exposure to unloading or low mechanical load. These molecular pathways interact with each other during atrophy and also when various interventions are applied that could alleviate atrophy. Re-applying mechanical load is an obvious method to restore muscle mass, however how nutrient supplementation (e.g. amino acids may further enhance recovery (or reduce atrophy despite unloading or ageing is currently of great interest. Satellite cells are particularly responsive to myostatin and to growth factors. Recently, the hibernating squirrel has been identified as an innovative model to study resistance to atrophy.

The nucleus is irreversibly shaped by motion of cell boundaries in cancer and non-cancer cells.

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Tocco, Vincent J; Li, Yuan; Christopher, Keith G; Matthews, James H; Aggarwal, Varun; Paschall, Lauren; Luesch, Hendrik; Licht, Jonathan D; Dickinson, Richard B; Lele, Tanmay P

2018-02-01

Actomyosin stress fibers impinge on the nucleus and can exert compressive forces on it. These compressive forces have been proposed to elongate nuclei in fibroblasts, and lead to abnormally shaped nuclei in cancer cells. In these models, the elongated or flattened nuclear shape is proposed to store elastic energy. However, we found that deformed shapes of nuclei are unchanged even after removal of the cell with micro-dissection, both for smooth, elongated nuclei in fibroblasts and abnormally shaped nuclei in breast cancer cells. The lack of shape relaxation implies that the nuclear shape in spread cells does not store any elastic energy, and the cellular stresses that deform the nucleus are dissipative, not static. During cell spreading, the deviation of the nucleus from a convex shape increased in MDA-MB-231 cancer cells, but decreased in MCF-10A cells. Tracking changes of nuclear and cellular shape on micropatterned substrata revealed that fibroblast nuclei deform only during deformations in cell shape and only in the direction of nearby moving cell boundaries. We propose that motion of cell boundaries exert a stress on the nucleus, which allows the nucleus to mimic cell shape. The lack of elastic energy in the nuclear shape suggests that nuclear shape changes in cells occur at constant surface area and volume. © 2017 Wiley Periodicals, Inc.

Actin polymerisation at the cytoplasmic face of eukaryotic nuclei

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David-Watine Brigitte

2006-05-01

Full Text Available Abstract Background There exists abundant molecular and ultra-structural evidence to suggest that cytoplasmic actin can physically interact with the nuclear envelope (NE membrane system. However, this interaction has yet to be characterised in living interphase cells. Results Using a fluorescent conjugate of the actin binding drug cytochalasin D (CD-BODIPY we provide evidence that polymerising actin accumulates in vicinity to the NE. In addition, both transiently expressed fluorescent actin and cytoplasmic micro-injection of fluorescent actin resulted in accumulation of actin at the NE-membrane. Consistent with the idea that the cytoplasmic phase of NE-membranes can support this novel pool of perinuclear actin polymerisation we show that isolated, intact, differentiated primary hepatocyte nuclei support actin polymerisation in vitro. Further this phenomenon was inhibited by treatments hindering steric access to outer-nuclear-membrane proteins (e.g. wheat germ agglutinin, anti-nesprin and anti-nucleoporin antibodies. Conclusion We conclude that actin polymerisation occurs around interphase nuclei of living cells at the cytoplasmic phase of NE-membranes.

Tracking of cell nuclei for assessment of in vitro uptake kinetics in ultrasound-mediated drug delivery using fibered confocal fluorescence microscopy.

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Derieppe, Marc; de Senneville, Baudouin Denis; Kuijf, Hugo; Moonen, Chrit; Bos, Clemens

2014-10-01

Previously, we demonstrated the feasibility to monitor ultrasound-mediated uptake of a cell-impermeable model drug in real time with fibered confocal fluorescence microscopy. Here, we present a complete post-processing methodology, which corrects for cell displacements, to improve the accuracy of pharmacokinetic parameter estimation. Nucleus detection was performed based on the radial symmetry transform algorithm. Cell tracking used an iterative closest point approach. Pharmacokinetic parameters were calculated by fitting a two-compartment model to the time-intensity curves of individual cells. Cells were tracked successfully, improving time-intensity curve accuracy and pharmacokinetic parameter estimation. With tracking, 93 % of the 370 nuclei showed a fluorescence signal variation that was well-described by a two-compartment model. In addition, parameter distributions were narrower, thus increasing precision. Dedicated image analysis was implemented and enabled studying ultrasound-mediated model drug uptake kinetics in hundreds of cells per experiment, using fiber-based confocal fluorescence microscopy.

Structure of Light Neutron-rich Nuclei

International Nuclear Information System (INIS)

Dlouhy, Zdenek

2007-01-01

In this contribution we searched for irregularities in various separation energies in the frame of mass measurement of neutron-rich nuclei at GANIL. On this basis we can summarize that the new doubly magic nuclei are 8 He, 22 O and 24 O. They are characterized by extra stability and, except 24 O, they cannot accept and bind additional neutrons. However, if we add to these nuclei a proton we obtain 9 Li and 25 F which are the core for two-neutron halo nucleus 11 Li and enables that fluorine can bound even 6 more neutrons, respectively. In that aspect the doubly magic nuclei in the neutron-rich region can form the basis either for neutron halo or very neutron-rich nuclei. (Author)

Extrachromosomal circles of satellite repeats and 5S ribosomal DNA in human cells

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Cohen Sarit

2010-03-01

Full Text Available Abstract Background Extrachomosomal circular DNA (eccDNA is ubiquitous in eukaryotic organisms and was detected in every organism tested, including in humans. A two-dimensional gel electrophoresis facilitates the detection of eccDNA in preparations of genomic DNA. Using this technique we have previously demonstrated that most of eccDNA consists of exact multiples of chromosomal tandemly repeated DNA, including both coding genes and satellite DNA. Results Here we report the occurrence of eccDNA in every tested human cell line. It has heterogeneous mass ranging from less than 2 kb to over 20 kb. We describe eccDNA homologous to human alpha satellite and the SstI mega satellite. Moreover, we show, for the first time, circular multimers of the human 5S ribosomal DNA (rDNA, similar to previous findings in Drosophila and plants. We further demonstrate structures that correspond to intermediates of rolling circle replication, which emerge from the circular multimers of 5S rDNA and SstI satellite. Conclusions These findings, and previous reports, support the general notion that every chromosomal tandem repeat is prone to generate eccDNA in eukryoric organisms including humans. They suggest the possible involvement of eccDNA in the length variability observed in arrays of tandem repeats. The implications of eccDNA on genome biology may include mechanisms of centromere evolution, concerted evolution and homogenization of tandem repeats and genomic plasticity.

Cosmology and unstable nuclei

International Nuclear Information System (INIS)

Schramm, D.N.

1995-01-01

Primordial nucleosynthesis has established itself as one of the three pillars of Big Bang cosmology. Many of the Big Bang Nucleosynthesis reactions involve unstable nuclei. Hence there is a tight relationship hetween the subject of this conference and cosmology. The prime role of unstable nuclei in cosmology is related to lithium synthesis and the lack of cosmological synthesis of Be and B. These nuclei will thus be focused upon. Nucleosynthesis involves comparing calculated abundances with observed abundances. In general, abundance determinations are dominated by systematic rather than statistical errors, and work on bounding systematics is crucial. The quark-hadron inspired inhomogeneous calculations now unanimously agree that only relatively small variations in Ω b are possible vis-a-vis the homogeneous model; hence the robustness of Ω b ∼0.05 is now apparent. (These calculations depend critically on unstable nuclei.) The above argues that the bulk of the baryons in the universe are not producing visible light. A comparison with the ROSAT cluster data is also shown to be consistent with the standard BBN model. Ω b ∼1 seems to be definitely excluded, so if Ω TOTAL =1, as some recent observations may hint, then non-baryonic dark matter is required. The implications of the recently reported halo microlensing events are discussed. In summary, it is argued that the physics of unstable nuclei affects the fundamental dark matter argument. ((orig.))

Vibrational-rotational model of odd-odd nuclei

International Nuclear Information System (INIS)

Afanas'ev, A.V.; Guseva, T.V.; Tamberg, Yu.Ya.

1988-01-01

The rotational vibrational (RV) model of odd nuclei is generalized to odd-odd nuclei. The hamiltonian, wave functions and matrix elements of the RV-model of odd-odd nuclei are obtained. The expressions obtained for matrix elements of the RV-model of odd-odd nuclei can be used to study the role of vibrational additions in low-lying two-particle states of odd-odd deformed nuclei. Such calculations permit to study more correctly the residual neutron-proton interaction of valent nucleons with respect to collectivization effects

Replication labeling patterns and chromosome territories typical of mammalian nuclei are conserved in the early metazoan Hydra.

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Alexandrova, Olga; Solovei, Irina; Cremer, Thomas; David, Charles N

2003-12-01

To investigate the evolutionary conservation of higher order nuclear architecture previously described for mammalian cells we have analyzed the nuclear architecture of the simple polyp Hydra. These diploblastic organisms have large nuclei (8-10 microm) containing about 3x10(9) bp of DNA organized in 15 chromosome pairs. They belong to the earliest metazoan phylum and are separated from mammals by at least 600 million years. Single and double pulse labeling with halogenated nucleotides (bromodeoxyuridine, iododeoxyuridine and chlorodeoxyuridine) revealed striking similarities to the known sequence of replication labeling patterns in mammalian nuclei. These patterns reflect a persistent nuclear arrangement of early, mid-, and late replicating chromatin foci that could be identified during all stages of interphase over at least 5-10 cell generations. Segregation of labeled chromatids led after several cell divisions to nuclei with single or a few labeled chromosome territories. In such nuclei distinct clusters of labeled chromatin foci were separated by extended nuclear areas with non-labeled chromatin, which is typical of a territorial arrangement of interphase chromosomes. Our results indicate the conservation of fundamental features of higher order chromatin arrangements throughout the evolution of metazoan animals and suggest the existence of conserved mechanism(s) controlling this architecture.

Nuclei with exotic constituents

International Nuclear Information System (INIS)

Yamazaki, Toshimitsu.

1990-08-01

We discuss various interesting features in the behavior of exotic constituents of nuclei such as hyperons and mesons, in particular, with emphases on the aspect of exotic halos which are formed in general by short-range repulsion and long-range attraction. Specifically, Λ and Σ hypernuclei and pionic nuclei are discussed. (author)

The colours of Hubble Sc galaxy nuclei

International Nuclear Information System (INIS)

Iskudaryan, S.G.

1975-01-01

The colorimetric data on the nuclei of the Sc galaxies are given. Comparison of the following parameters: color of a nucleus, integral color of a galaxy, Byurakan class, and spectral type of normal spirals gives the possibility to conclude: (1) The colors of the nuclei of the Sc galaxies have a high dispersion in its values. In all Byurakan classes the galaxies with intensely red and blue nuclei occur; (2) Some Sc galaxies exhibit a discrepancy between the spectral and morphological types. The results of colorimetry of nuclei indicate that almost all such Sc galaxies have intensely red nuclei which, naturally, provide for these late spectral types. It can be assumed that the intensely red color of the nuclei of such Sc galaxies is a result of a new type of activity of these nuclei; and (3) some Sc galaxies show the characteristics of the Markarian objects

A new immuno- dystrophin-deficient model, the NSG-mdx4Cv mouse, provides evidence for functional improvement following allogeneic satellite cell transplantation

Science.gov (United States)

Arpke, Robert W.; Darabi, Radbod; Mader, Tara L.; Zhang, Yu; Toyama, Akira; Lonetree, Cara-lin; Nash, Nardina; Lowe, Dawn A.; Perlingeiro, Rita C.R.; Kyba, Michael

2013-01-01

Transplantation of a myogenic cell population into an immunodeficient recipient is an excellent way of assessing the in vivo muscle-generating capacity of that cell population. To facilitate both allogeneic and xenogeneic transplantations of muscle-forming cells in mice we have developed a novel immunodeficient muscular dystrophy model, the NSG-mdx4Cv mouse. The IL2Rg mutation, which is linked to the Dmd gene on the X chromosome, simultaneously depletes NK cells and suppresses thymic lymphomas, issues that limit the utility of the SCID/mdx model. The NSG-mdx4Cv mouse presents a muscular dystrophy of similar severity to the conventional mdx mouse. We show that this animal supports robust engraftment of both pig and dog muscle mononuclear cells. The question of whether satellite cells prospectively isolated by flow cytometry can confer a functional benefit upon transplantation has been controversial. Using allogeneic Pax7-ZsGreen donors and NSG-mdx4Cv recipients, we demonstrate definitively that as few as 900 FACS-isolated satellite cells can provide functional regeneration in vivo, in the form of an increased mean maximal force-generation capacity in cell-transplanted muscles, compared to a sham-injected control group. These studies highlight the potency of satellite cells to improve muscle function, and the utility of the NSG-mdx4Cv model for studies on muscle regeneration and Duchenne muscular dystrophy therapy. PMID:23606600

The correlation between uptake of methyl green and Feulgen staining intensity of cell nuclei. An image analysis study

DEFF Research Database (Denmark)

Lyon, H; Schulte, E; Hoyer, P E

1989-01-01

were stored in the computer, making it possible to measure the same cells in the Feulgen-restained sections. Image analysis gave results which invalidate the sequential methods as opposed to the simultaneous method. Mean optical densities were significantly increased for both dyes with the simultaneous...... method after formaldehyde fixation as compared to Carnoy fixation. The quantitative correlation of Methyl Green and DNA in the simultaneous technique was found to parallel exactly that of the Feulgen stain. In conclusion, the simultaneous Methyl Green-Pyronin technique is recommended while the sequential......Paraffin sections of rat tissue fixed in either formaldehyde solution (3.6% w/v) or in Carnoy's fluid were stained using standardized Methyl Green-Pyronin procedures with the dyes used either simultaneously or in sequence. The sections were evaluated for the uptake of the two dyes by cell nuclei...

Light scattering microscopy measurements of single nuclei compared with GPU-accelerated FDTD simulations

International Nuclear Information System (INIS)

Stark, Julian; Rothe, Thomas; Kienle, Alwin; Kieß, Steffen; Simon, Sven

2016-01-01

Single cell nuclei were investigated using two-dimensional angularly and spectrally resolved scattering microscopy. We show that even for a qualitative comparison of experimental and theoretical data, the standard Mie model of a homogeneous sphere proves to be insufficient. Hence, an accelerated finite-difference time-domain method using a graphics processor unit and domain decomposition was implemented to analyze the experimental scattering patterns. The measured cell nuclei were modeled as single spheres with randomly distributed spherical inclusions of different size and refractive index representing the nucleoli and clumps of chromatin. Taking into account the nuclear heterogeneity of a large number of inclusions yields a qualitative agreement between experimental and theoretical spectra and illustrates the impact of the nuclear micro- and nanostructure on the scattering patterns. (paper)

Light scattering microscopy measurements of single nuclei compared with GPU-accelerated FDTD simulations.

Science.gov (United States)

Stark, Julian; Rothe, Thomas; Kieß, Steffen; Simon, Sven; Kienle, Alwin

2016-04-07

Single cell nuclei were investigated using two-dimensional angularly and spectrally resolved scattering microscopy. We show that even for a qualitative comparison of experimental and theoretical data, the standard Mie model of a homogeneous sphere proves to be insufficient. Hence, an accelerated finite-difference time-domain method using a graphics processor unit and domain decomposition was implemented to analyze the experimental scattering patterns. The measured cell nuclei were modeled as single spheres with randomly distributed spherical inclusions of different size and refractive index representing the nucleoli and clumps of chromatin. Taking into account the nuclear heterogeneity of a large number of inclusions yields a qualitative agreement between experimental and theoretical spectra and illustrates the impact of the nuclear micro- and nanostructure on the scattering patterns.

Nuclei in high forms

International Nuclear Information System (INIS)

Szymanski, Z.; Berger, J.F.; Heenen, P.H.; Heyde, K.; Haas, B.; Janssens, R.; Paya, D.; Gogny, D.; Huber, G.; Bjoernholm, S.; Brack, M.

1991-01-01

The purpose of 1991 Joliot-Curie Summer School is to review the most advances in the understanding of the nuclei physics after the considerable progress in gamma spectroscopy. It covers the following topics: Highly and super-deformed nuclei, nuclear structures, mean-field approach and beyond, fission isomers, nuclear excitations with long lifetime and metal clusters

Exotic nuclei: another aspect of nuclear structure

International Nuclear Information System (INIS)

Dobaczewski, J.; Blumenfeld, Y.; Flocard, H.; Garcia Borge, M.J.; Nowacki, F.; Rombouts, S.; Theisen, Ch.; Marques, F.M.; Lacroix, D.; Dessagne, P.; Gaeggeler, H.

2002-01-01

This document gathers the lectures made at the Joliot Curie international summer school in 2002 whose theme that year was exotic nuclei. There were 11 contributions whose titles are: 1) interactions, symmetry breaking and effective fields from quarks to nuclei; 2) status and perspectives for the study of exotic nuclei: experimental aspects; 3) the pairing interaction and the N = Z nuclei; 4) borders of stability region and exotic decays; 5) shell structure of nuclei: from stability to decay; 6) variational approach of system with a few nucleons; 7) from heavy to super-heavy nuclei; 8) halos, molecules and multi-neutrons; 9) macroscopic approaches for fusion reactions; 10) beta decay: a tool for spectroscopy; 11) the gas phase chemistry of super-heavy elements

Exotic nuclei and radioactive beams

International Nuclear Information System (INIS)

Chomaz, P.

1996-01-01

The Nuclei called exotic are all the nuclei that it is necessary to recreate in laboratory to study them. Their life time is too short -in relation to earth age- for it remains enough on earth. The researchers are going to have at their s disposal at GANIL (Caen) with the S.P.I.R.A.L. project, exotic nuclei beams and will study new kinds of nuclear reactions to better understand the atom nucleus. (N.C.). 2 refs., 9 figs

Isotope shifts in unstable nuclei

International Nuclear Information System (INIS)

Rebel, H.

1980-05-01

Current experimental investigations of isotope shifts in atomic spectra of unstable nuclei and the resulting information about size and shape of nuclei far off stability are discussed with reference to some representative examples. (orig.)

Dynamic polarization of radioactive nuclei

International Nuclear Information System (INIS)

Kiselev, Yu.F.; Lyuboshits, V.L.; )

2001-01-01

Radioactive nuclei, embedded into a frozen polarized proton target, atr proposed to polarize by means of some dynamic polarization methods. Angular distributions of γ-quanta emitted ny 22 Na(3 + ) in the cascade β-γ-radiation are calculated. It is shown that this distribution does not depend on the spin temperature sing at the Boltzmann distribution of populations among the Zeeman magnetic substates, whereas the tensor polarization of quadrupole nuclei, placed in the electric field of the crystal, causes the considerable sing dependence. The new method promises wide opportunities for the magnetic structure investigations as well as for the study of spin-spin interaction dynamics of rare nuclei in dielectrics. Physical-technical advantages and disadvantages of the given method are discussed for the polarization of heavy nuclei in the on-line implantation mode [ru

Intralaminar nuclei of the thalamus in Lewy body diseases.

Science.gov (United States)

Brooks, Daniel; Halliday, Glenda M

2009-02-16

Although the intralaminar thalamus is a target of alpha-synuclein pathology in Parkinson's disease, the degree of neuronal loss in Lewy body diseases has not been assessed. We have used unbiased stereological techniques to quantify neuronal loss in intralaminar thalamic nuclei concentrating alpha-synuclein pathology (the anterodorsal, cucullar, parataenial, paraventricular, central medial, central lateral and centre-median/parafascicular complex) in different clinical forms of Lewy body disease (Parkinson's disease with and without dementia, and dementia with Lewy bodies, N=21) compared with controls (N=5). Associations were performed in the Lewy body cases between intralaminar cell loss and the main diagnostic clinical (parkinsonism, dementia, fluctuation in consciousness, and visual hallucinations) and pathological (Braak stage of Parkinson's disease) features of these diseases, as well as between cell loss and the scaled severity of the alpha-synuclein deposition within the intralaminar thalamus. As expected, significant alpha-synuclein accumulation occurred in the intralaminar thalamus in the cases with Lewy body disease. Pathology concentrated anteriorly and in the central lateral and paraventricular nuclei was related to the Braak stage of Parkinson's disease, ageing, and the presence of dementia. Across all types of Lewy body cases there was substantial atrophy and neuronal loss in the central lateral, cucullar and parataenial nuclei, and neuronal loss without atrophy in the centre-median/parafascicular complex. Cases with visual hallucinations showed a greater degree of atrophy of the cucullar nucleus, possibly due to amygdala denervation. The significant degeneration demonstrated in the intralaminar thalamus is likely to contribute to the movement and cognitive dysfunction observed in Lewy body disorders.

Eta mesons in nuclei

International Nuclear Information System (INIS)

Liu, L.C.

1987-01-01

The possibility of producing eta-mesic nuclei by the use of pions is discussed. If these nuclei are observed experimentally, then the binding energies of the eta in this new nuclear matter can be used to extract accurately the eta-N-N* coupling constant in a nucleus. The framework for these calculations is the coupled channel isobar model

Satellites of radio AGN in SDSS: Insights into agn triggering and feedback

Energy Technology Data Exchange (ETDEWEB)

Pace, Cameron; Salim, Samir, E-mail: cjpace@indiana.edu, E-mail: salims@indiana.edu [Indiana University, Department of Astronomy, Swain Hall West 319, Bloomington, IN 47405-7105 (United States)

2014-04-10

We study the effects of radio jets on galaxies in their vicinity (satellites) and the role of satellites in triggering radio-loud active galactic nuclei (AGNs). The study compares the aggregate properties of satellites of a sample of 7220 radio AGNs at z < 0.3 (identified by Best and Heckman from the SDSS and NVSS+FIRST surveys) to the satellites of a control sample of radio-quiet galaxies, which are matched in redshift, color, luminosity, and axis ratio, as well as by environment type: field galaxies, cluster members, and brightest cluster galaxies (BCGs). Remarkably, we find that radio AGNs exhibit on average a 50% excess (17σ significance) in the number of satellites within 100 kpc even though the cluster membership was controlled (e.g., radio BCGs have more satellites than radio-quiet BCGs, etc.). Satellite excess is not confirmed for high-excitation sources, which are only 2% of radio AGN. Extra satellites may be responsible for raising the probability for hot gas AGN accretion via tidal effects or may otherwise enhance the intensity or duration of the radio-emitting phase. Furthermore, we find that the incidence of radio AGNs among potential hosts (massive ellipticals) is similar for field galaxies and for non-BCG cluster members, suggesting that AGN fueling depends primarily on conditions in the host halo rather than the parent, cluster halo. Regarding feedback, we find that radio AGNs, either high or low excitation, have no detectable effect on star formation in their satellites, as neither induced star formation nor star formation quenching is present in more than ∼1% of radio AGN.

Satellites of radio AGN in SDSS: Insights into agn triggering and feedback

International Nuclear Information System (INIS)

Pace, Cameron; Salim, Samir

2014-01-01

We study the effects of radio jets on galaxies in their vicinity (satellites) and the role of satellites in triggering radio-loud active galactic nuclei (AGNs). The study compares the aggregate properties of satellites of a sample of 7220 radio AGNs at z < 0.3 (identified by Best and Heckman from the SDSS and NVSS+FIRST surveys) to the satellites of a control sample of radio-quiet galaxies, which are matched in redshift, color, luminosity, and axis ratio, as well as by environment type: field galaxies, cluster members, and brightest cluster galaxies (BCGs). Remarkably, we find that radio AGNs exhibit on average a 50% excess (17σ significance) in the number of satellites within 100 kpc even though the cluster membership was controlled (e.g., radio BCGs have more satellites than radio-quiet BCGs, etc.). Satellite excess is not confirmed for high-excitation sources, which are only 2% of radio AGN. Extra satellites may be responsible for raising the probability for hot gas AGN accretion via tidal effects or may otherwise enhance the intensity or duration of the radio-emitting phase. Furthermore, we find that the incidence of radio AGNs among potential hosts (massive ellipticals) is similar for field galaxies and for non-BCG cluster members, suggesting that AGN fueling depends primarily on conditions in the host halo rather than the parent, cluster halo. Regarding feedback, we find that radio AGNs, either high or low excitation, have no detectable effect on star formation in their satellites, as neither induced star formation nor star formation quenching is present in more than ∼1% of radio AGN.

Multifragmentation of hot nuclei

International Nuclear Information System (INIS)

Tamain, B.

1990-10-01

It is difficult to deposit a large amount (∼ 1 Gev) of excitation energy into a nucleus. And if one wants to deposit large excitation energy values, the best way consists of shooting a given target nucleus with several nucleons, which can be achieved by using intermediate energy (10-100 MeV/nucleon) heavy ions. Such very excited objects were named hot nuclei. The study of hot nuclei has been undertaken only for 7 years because intermediate energy heavy ion facilities were not available before. The game is then to determine the decay properties of such nuclei, their limits of existence. Their study is connected with general properties of nuclear matter: namely its equation of state. Of special interest, is the onset of a new decay mechanism: multifragmentation, which is the non-sequential disassembly of a hot nucleus into several light nuclei (often called intermediate-mass fragments or IMF) or particles. This paper, shows how this mechanism can reflect fundamental properties of nuclear matter, but also how its experimental signature is difficult to establish. Multifragmentation has also been studied by using very energetic projectiles (protons and heavy ions) in the relativistic or ultra-relativistic region. The multifragmentation question of hot nuclei is far from being solved. One knows that IMF production increases when the excitation energy brought into a system is strongly increased, but very little is known about the mechanisms involved and a clear onset for multifragmentation is not established

Prognostic significance of morphometric parameters of nucleoli and nuclei of invasive ductal breast carcinomas.

Science.gov (United States)

Karpińska-Kaczmarczyk, Katarzyna; Kram, Andrzej; Kaczmarczyk, Mariusz; Domagała, Wenancjusz

2009-01-01

The aim of this study was to evaluate associations between seven morphometric parameters of the nucleoli and nuclei of methyl green and pyronin Y (MG-PY) stained tumour cells of invasive ductal breast carcinoma with relapse-free survival (RFS) and overall survival (OS) time. Histological sections from 150 invasive ductal breast cancers were stained with MG-PY and the following parameters were evaluated by computer image analysis: the nucleolar area, long to short nucleolar axis ratio, nucleolar shape parameter assessing the degree of nucleolar roundness, long to short nuclear axis ratio, number of nucleoli in the nucleus and the percentage of the nuclear cross-section surface area occupied by the nucleoli. A statistically significant association between a nucleolar shape polymorphism and the number of nucleoli in the nuclei of tumour cells and the RFS but not OS was found in the entire group of patients as well as patients with axillary lymph node metastases. A higher polymorphism of nucleolar shape and a higher number of nucleoli in the nuclei of breast cancer cells were associated with decreased relapse-free survival (p nucleoli in MG-PY stained histological sections can be useful in the analysis of associations between nucleolar parameters and prognosis of patients with invasive breast cancer.

[Properties and localization of Mg- and Ca-ATpase activities in wheat embryo cell nuclei].

Science.gov (United States)

Vasil'eva, N A; Belkina, G G; Stepanenko, S Y; Atalykova, F I; Oparin, A I

1978-05-01

The isolated nuclei of wheat embryo possess the ATPase activity. The addition of Mg2+ and Ca2+ significantly increases the activities of nuclear ATPases, whereas Hg2+, Cu2+ and Mn2+ inhibit the activity. The activating effect of Mg2+ is enhanced by an addition of Na and K ions. The activity of wheat embryo nuclear Mg-ATPase is higher than its Ca-ATPase activity; both ATPases also differ in their pH optima. Separation of total nuclear protein according to the solubility of its individual protein components in wheat and strong salt solutions, using the detergents, as well as ammonium sulfate precipitation and dialysis do not result in separation of Mg-activated and Ca-activated ATPases, although their levels of activities and ratios change in the course of fractionation. The Mg- and Ca-ATPase activities of the wheat embryo nuclei were found in the nuclear fraction of albumin, in nonhistone proteins and nuclear membranes. In the albumin nuclear fraction and subfractions of non-histone proteins the higher level of activity is observed in Ca-ATPase, whereas in the nuclei and soluble fractions of residual proteins in Mg-ATPase.

The first estimates of global nucleation mode aerosol concentrations based on satellite measurements

Directory of Open Access Journals (Sweden)

M. Kulmala

2011-11-01

Full Text Available Atmospheric aerosols play a key role in the Earth's climate system by scattering and absorbing solar radiation and by acting as cloud condensation nuclei. Satellites are increasingly used to obtain information on properties of aerosol particles with a diameter larger than about 100 nm. However, new aerosol particles formed by nucleation are initially much smaller and grow into the optically active size range on time scales of many hours. In this paper we derive proxies, based on process understanding and ground-based observations, to determine the concentrations of these new particles and their spatial distribution using satellite data. The results are applied to provide seasonal variation of nucleation mode concentration. The proxies describe the concentration of nucleation mode particles over continents. The source rates are related to both regional nucleation and nucleation associated with more restricted sources. The global pattern of nucleation mode particle number concentration predicted by satellite data using our proxies is compared qualitatively against both observations and global model simulations.

Phosphoprotein phosphatase of bovine spleen cell nuclei: physicochemical properties

International Nuclear Information System (INIS)

Rezyapkin, V.I.; Leonova, L.E.; Komkova, A.I.

1986-01-01

The physicochemical properties of phosphoprotein phosphatase (EC 1.3.1.16) from bovine spleen cell nuclei were studied. The enzyme possesses broad substrate specificity and catalyzes the dephosphorylation of phosphocasein, ATP, ADP, and p-nitrophenyl phosphate (pNPP). K/sub m/ for ATP, ADP, and pNPP are equal to 0.44, 0.43, and 1.25 mM, respectively. M/sub r/ of the enzyme, according to the data of gel filtraction of Sephadex G-75 and electrophoresis in polyacrylamide gel of various concentrations is ∼ 33,000. In electrophoresis in the presence of SDS, two protein bands with M/sub r/ 12,000 and 18,000 are detected. In the enzyme molecule, acid amino acid residues predominate; two free SH groups and two disulfide bridges are detected. Phosphoprotein phosphatase is a glycoprotein, containing ∼ 22% carbonhydrates. The protein possesses a supplementary absorption maximum at 560 nm. Ammonium molybdate is a competitive inhibitor with K/sub i/ 0.37 μM, while sodium fluoride is a noncompetitive inhibitor with K/sub i/ 1.3 mM. Incubation in the presence of 2 mM phenylmethylsulfonyl fluoride for 25 h leads to a loss of ∼ 46% of the enzymatic activity. Ammonium molybdate, sodium fluoride, and PMSF are reversible inhibitors. Modifications of the SH groups, NH 2 groups, and histidine leads to a decrease in the enzymatic activity. Incubation of phosphoprotein phosphatase with [γ- 32 P]ATP leads to the incorporation of 0.33 mole 33 P per mole of the enzyme. The mechanism of hydrolysis of the phosphodiester bond, catalyzed by the enzyme, is discussed

nuclei

Directory of Open Access Journals (Sweden)

Minkov N.

2016-01-01

Full Text Available We study the effects of quadrupole-octupole deformations on the energy and magnetic properties of high-K isomeric states in even-even heavy and superheavy nuclei. The neutron two-quasiparticle (2qp isomeric energies and magnetic dipole moments are calculated within a deformed shell model with the Bardeen-Cooper- Schrieffer (BCS pairing interaction over a wide range of quadrupole and octupole deformations. We found that in most cases the magnetic moments exhibit a pronounced sensitivity to the octupole deformation, while the 2qp energies indicate regions of nuclei in which the presence of high-K isomeric states may be associated with the presence of octupole softness or even with octupole deformation. In the present work we also examine the influence of the BCS pairing strength on the energy of the blocked isomer configuration. We show that the formation of 2qp energy minima in the space of quadrupole-octupole and eventually higher multipolarity deformations is a subtle effect depending on nuclear pairing correlations.

Are there multiquark bags in nuclei

International Nuclear Information System (INIS)

Kondratyuk, L.A.; Scmatkov, M.Zh.

1983-01-01

Arguments are presented favouring the idea that multiquark bags do eXist in nuclei. Such hypothesis makes possible to reveal the relationship among three different scopes of phenomena: deep inelastic scattering of leptons by nUclei, large q 2 (where q 2 is a square of momentum transfer) behaviour of the form factors of light nuclei and yield of cumulative proton.s

Electron scattering for exotic nuclei

International Nuclear Information System (INIS)

Suda, T.

2013-01-01

An electron scattering facility is under construction in RIKEN RI Beam Factory, Japan, which is dedicated to the structure studies of short-lived nuclei. This is the world's first and currently only facility of its type. The construction is nearly completed, and the first electron scattering experiment off short-lived nuclei will be carried out in the beginning of next year. The charge density distributions of short-lived nuclei will be precisely determined by elastic electron scattering for the first time. Physics pursued at this facility including future perspectives are explained

The decay of hot nuclei

International Nuclear Information System (INIS)

Moretto, L.G.; Wozniak, G.J.

1988-11-01

The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs

Changes of the size of liver cell nuclei after X-radiation and galactosamine application

Energy Technology Data Exchange (ETDEWEB)

Schneikert, D

1974-10-23

The behaviour of cell nuclei in the rat liver eight days and three months after a single irradiation with 800 R is observed in the present study. A significantly changed nuclear pattern was found in the animals killed after 8 days; the curve of the nuclear volume shows a strong displacement to the right in the polyploid region. This trend is weakly exhibited in the grown rats killed after three months. The influence of X-radiation shows a nuclear displacement in the young rats which approximates to the pattern of the grown-up, non-treated rats. The two-peaked slope becomes three-peaked and furthermore shows a right displacement in the region in which the nuclear volume curve of the grown-up rats is found. If the pre-irradiated animals receive a galactosamine injection 1 day before being killed, the right displacement is even more apparent and the changes in the ploidy pattern are mostly highly significant.

Thermodynamics of pairing phase transition in nuclei

International Nuclear Information System (INIS)

Karim, Afaque; Ahmad, Shakeb

2014-01-01

The pairing gaps, pairing energy, heat capacity and entropy are calculated within BCS (Bardeen- Cooper-Schrieffer) based quasi particle approach, including thermal fluctuations on pairing field within pairing model for all nuclei (light, medium, heavy and super heavy nuclei). Quasi particles approach in BCS theory was introduced and reformulated to study various properties. For thermodynamic behavior of nuclei at finite temperatures, the anomalous averages of creation and annihilation operators are introduced. It is solved self consistently at finite temperatures to obtain BCS Hamiltonian. After doing unitary transformation, we obtained the Hamiltonian in the diagonal form. Thus, one gets temperature dependence gap parameter and pairing energy for nuclei. Moreover, the energy at finite temperatures is the sum of the condensation energy and the thermal energy of fermionic quasi particles. With the help of BCS Hamiltonian, specific heat, entropy and free energy are calculated for different nuclei. In this paper the gap parameter occupation number and pairing energy as a function of temperature which is important for all the light, medium, heavy and super heavy nuclei is calculated. Moreover, the various thermo dynamical quantities like specific heat, entropy and free energy is also obtained for different nuclei. Thus, the thermodynamics of pairing phase transition in nuclei is studied

On the distribution of quarks in nuclei

International Nuclear Information System (INIS)

Baldin, A.M.; Panebrattsev, V.S.; Stavinskij, V.S.

1984-01-01

On the basis of the data on cumulative proton, deuteron and nuclear fragment production in hadr on-nucleon reactions and deep inelastic muon-nucleon scattering quark distributions in light, intemediate and heavy nuclei have been investigated. Conditions of limiting fragmentation of hadrons and nuclei in the studied processes have been investigated to obtain quark-parton structure functions (Gs 2 ) of the studied hadrons or nuclei. Invariant differential cross sections of π + , π - , K + meson production on aluminium, deuterium and lead nuclei and their dependence on scale variable at the transverse momentum value Psub(T) approximately 0 have been obtained. Properties of structure functions G 2 and behaviour of different nuclei differential cross sections of limiting fragmentation have been investigated. It is concluded that considered regularities testify to the presence of multiquark states in nuclei, different by its structure from nUcleons

Collisions with nuclei

International Nuclear Information System (INIS)

Gulamov, K.G.

1987-01-01

It is well known that interactions of high energy particles with nuclei, owing to possible intranuclear rescatterings, may provide information about the space-time behaviour of the production process. Therefore the main goals of these investigations are related with the attempts to study the space-time process of hadronization of coloured quarks and gluons produced at the initial stage of an interaction to white final state particles and to clarify the influence of composite quark-gluon structure of both the projectile and target on features of the production mechanisms. Since in both the initial and final states of these reactions the authors have strongly interacting multiparticle systems, it is of importance to study the collective properties of these systems. The questions to the point are: what is the degree of collectivization of particles newly produced in collisions with nuclei and what is the influence of the collective nature of a nucleus itself on the production mechanisms, in particular, what are the manifestations of possible multinucleon (multiquark) configurations in nuclei? It is obvious that the reductability of, say, hadron-nucleus (hA) interaction to hadron-nucleon (hN) collisions is directly related to the above problems. Due to time limitations the author discusses here only a few aspects of low p/sub t/ hA interactions which in his opinion are of importance for better understanding of general regularities of collisions with nuclei and for further investigations of the above problems

Incorporation of thymidine into onion root meristematic cell nuclei in presence of hydroxyurea and its role in recovery of mitotic activity

OpenAIRE

H. Habdas

2015-01-01

Hydroxyurea treatment of onion roots induced mitotic block which was released by transfer of bulbs to water, and also to some extent by addition of cold or 3H-thymidine to hydroxyurea solutions. In presence of hydroxyurea there was noted very intense incorporation of 3H-thymidine into cell nuclei, giving labelling index of 40-70%. However, all the mitotic figures appearing in presence of hydroxyurea and 3H-thymidine were unlabelled. On the other hand, labelled mitotic figures were obtained wh...

Spectroscopy of heavy fissionable nuclei

Indian Academy of Sciences (India)

2015-08-05

Aug 5, 2015 ... Nuclei in the actinide chain and beyond are prone to fission owing to ... mass nuclei are typically more difficult, because the intensity is .... j15/2 neutron alignments in a region where shell stablization effects are crucial.

Localization Microscopy Analyses of MRE11 Clusters in 3D-Conserved Cell Nuclei of Different Cell Lines

Directory of Open Access Journals (Sweden)

Marion Eryilmaz

2018-01-01

Full Text Available In radiation biophysics, it is a subject of nowadays research to investigate DNA strand break repair in detail after damage induction by ionizing radiation. It is a subject of debate as to what makes up the cell’s decision to use a certain repair pathway and how the repair machinery recruited in repair foci is spatially and temporarily organized. Single-molecule localization microscopy (SMLM allows super-resolution analysis by precise localization of single fluorescent molecule tags, resulting in nuclear structure analysis with a spatial resolution in the 10 nm regime. Here, we used SMLM to study MRE11 foci. MRE11 is one of three proteins involved in the MRN-complex (MRE11-RAD50-NBS1 complex, a prominent DNA strand resection and broken end bridging component involved in homologous recombination repair (HRR and alternative non-homologous end joining (a-NHEJ. We analyzed the spatial arrangements of antibody-labelled MRE11 proteins in the nuclei of a breast cancer and a skin fibroblast cell line along a time-course of repair (up to 48 h after irradiation with a dose of 2 Gy. Different kinetics for cluster formation and relaxation were determined. Changes in the internal nano-scaled structure of the clusters were quantified and compared between the two cell types. The results indicate a cell type-dependent DNA damage response concerning MRE11 recruitment and cluster formation. The MRE11 data were compared to H2AX phosphorylation detected by γH2AX molecule distribution. These data suggested modulations of MRE11 signal frequencies that were not directly correlated to DNA damage induction. The application of SMLM in radiation biophysics offers new possibilities to investigate spatial foci organization after DNA damaging and during subsequent repair.

Incorporation of tritiated thymidine and uridine in normal and endopolyploid nuclei of differentiated tissue

International Nuclear Information System (INIS)

Bansal, Y.K.; Sen, Sumitra

1987-01-01

Rate of replication and transcription between normal and giant endopolyploid nuclei of differentiated tissue of Hordeum vulgare L. (2n=14) roots and Phlox drummondii Hook. (2n=14) and Zea mays L. (2n=20) endosperms were studied by labelling experiments with tritiated thymidine and uridine. The incorporation of thymidine and uridine was identical in both diploid and giant endopolyploid nuclei of the roots of H. vulgare. The endosperm cells of P. drummondii and Z. mays, however, exhibit markedly different labelling pattern in normal (i.e. triploid) and endopolyploid nuclei where both replication and transcription were rather high. The nutritive function of the endosperm is probably responsible for this high degree of activity. (author). 14 refs., 10 figs., 3 tables

The use of bead beating to prepare suspensions of nuclei for flow cytometry from fresh leaves, herbarium leaves, petals and pollen.

Science.gov (United States)

Roberts, Andy V

2007-12-01

"Bead beating" is commonly used to release DNA from cells for genomic studies but it was used here to prepare suspensions of plant nuclei for measurement of DNA amounts by flow cytometry. Plant material was placed in 2-ml screw-capped tubes containing beads of zirconia/silica (2.5 mm diameter) or glass (2.5 or 1.0 mm diameter) and 1 ml of lysis buffer. The tubes were mechanically shaken with an FP120 FastPrep Cell Disrupter to release intact nuclei from plant tissue by the impact of the beads. The nuclei were then stained with propidium iodide (PI) and analyzed by flow cytometry. The method was tested using fresh leaves, fresh petals and herbarium leaves of Rosa canina, leaves and pollen of R. rugosa, and fresh leaves of Petroselinum crispum, Nicotiana tabacum, and Allium cepa. Batches of 12 samples of fresh leaves were prepared, simultaneously, in 45 s by bead beating in the Cell Disrupter. In flow cytometry histograms, nuclei of fresh leaves gave G(1)/G(0) peaks with CVs of less than 3.0% and nuclei from fresh petals and herbarium leaves of R. canina, and pollen of the generative nuclei of R. rugosa gave peaks with coefficients of variation (CVs) of less than 4.0%. DNA amounts estimated from 24-month-old herbarium leaves, using P. crispum as an internal standard, were less than those of fresh leaves by a small but significant amount. Suspensions of nuclei can be prepared rapidly and conveniently from a diversity of tissues by bead beating. Exposure of laboratory workers to harmful substances in the lysis buffer is minimized. (c) 2007 International Society for Analytical Cytology

From heavy nuclei to super-heavy nuclei; Des noyaux lourds aux super-lourds

Energy Technology Data Exchange (ETDEWEB)

Theisen, Ch

2003-01-01

The existence of super-heavy nuclei has been predicted nearly fifty years ago. Due to the strong coulomb repulsion, the stabilisation of these nuclei is possible only through shell effects. The reasons for this fragile stability, as well as the theoretical predictions concerning the position of the island of stability are presented in the first part of this lecture. In the second part, experiments and experimental techniques which have been used to synthesize or search for super-heavy elements are described. Spectroscopic studies performed in very heavy elements are presented in the following section. We close this lecture with techniques that are currently being developed in order to reach the superheavy island and to study the structure of very-heavy nuclei. (author)

Colliding nuclei

International Nuclear Information System (INIS)

Balian, Roger; Remaud, Bernard; Suraud, E.; Durand, Dominique; Tamain, Bernard; Gobbi, A.; Cugnon, J.; Drapier, Olivier; Govaerts, Jan; Prieels, Rene

1995-09-01

This 14. international school Joliot-Curie of nuclear physic deals with nuclei in collision at high energy. Nine lectures are included in the proceedings of this summer school: 1 - From statistical mechanics outside equilibrium to transport equations (Balian, R.); 2 - Modeling of heavy ions reactions (Remaud, B.); 3 - Kinetic equations in heavy ions physics (Suraud, E.); 4 - Colliding nuclei near the Fermi energy (Durand, D.; Tamain, B.); 5 - From the Fermi to the relativistic energy domain: which observable? For which physics? (Gobbi, A.); 6 - Collisions at relativistic and ultra relativistic energies, Theoretical aspects (Cugnon, J.); 7 - Quark-gluon plasma: experimental signatures (Drapier, O.); 8 - Electroweak interaction: a window on physics beyond the standard model (Govaerts, J.); 9 - Symmetry tests in β nuclear process: polarization techniques (Prieels, R.)

Symmetry and Phase Transitions in Nuclei

International Nuclear Information System (INIS)

Iachello, F.

2009-01-01

Phase transitions in nuclei have received considerable attention in recent years, especially after the discovery that, contrary to expectations, systems at the critical point of a phase transition display a simple structure. In this talk, quantum phase transitions (QPT), i.e. phase transitions that occur as a function of a coupling constant that appears in the quantum Hamiltonian, H, describing the system, will be reviewed and experimental evidence for their occurrence in nuclei will be presented. The phase transitions discussed in the talk will be shape phase transitions. Different shapes have different symmetries, classified by the dynamic symmetries of the Interacting Boson Model, U(5), SU(3) and SO(6). Very recently, the concept of Quantum Phase Transitions has been extended to Excited State Quantum Phase Transitions (ESQPT). This extension will be discussed and some evidence for incipient ESQPT in nuclei will be presented. Systems at the critical point of a phase transition are called 'critical systems'. Approximate analytic formulas for energy spectra and other properties of 'critical nuclei', in particular for nuclei at the critical point of the second order U(5)-SO(6) transition, called E(5), and along the line of first order U(5)-SU(3) transitions, called X(5), will be presented. Experimental evidence for 'critical nuclei' will be also shown. Finally, the microscopic derivation of shape phase transitions in nuclei within the framework of density functional methods will be briefly discussed.(author)

Deformation and shape coexistence in medium mass nuclei

International Nuclear Information System (INIS)

Meyer, R.A.

1985-01-01

Emerging evidence for deformed structures in medium mass nuclei is reviewed. Included in this review are both nuclei that are ground state symmetric rotors and vibrational nuclei where there are deformed structures at excited energies (shape coexistence). For the first time, Nilsson configurations in odd-odd nuclei within the region of deformation are identified. Shape coexistence in nuclei that abut the medium mass region of deformation is also examined. Recent establishment of a four-particle, four-hole intruder band in the double subshell closure nucleus 96 Zr 56 is presented and its relation to the nuclear vibron model is discussed. Special attention is given to the N=59 nuclei where new data have led to the reanalysis of 97 Sr and 99 Zr and the presence of the [404 9/2] hole intruder state as isomers in these nuclei. The low energy levels of the N=59 nuclei from Z=38 to 50 are compared with recent quadrupole-phonon model calculations that can describe their transition from near-rotational to single closed shell nuclei. The odd-odd N=59 nuclei are discussed in the context of coexisting shape isomers based on the (p[303 5/2]n[404 9/2])2 - configuration. Ongoing in-beam (t,p conversion-electron) multiparameter measurements that have led to the determination of monopole matrix elements for even-even 42 Mo nuclei are presented, and these are compared with initial estimates using IBA-2 calculations that allow mixing of normal and cross subshell excitations. Lastly, evidence for the neutron-proton 3 S 1 force's influence on the level structure of these nuclei is discussed within the context of recent quadrupole-phonon model calculations. (Auth.)

Strength of Coriolis Coupling in actinide nuclei

International Nuclear Information System (INIS)

Peker, L.K.; Rasmussen, J.O.; Hamilton, J.H.

1982-01-01

Coriolis Coupling V/sub cor/ plays an important role in deformed nuclei. V/sub cor/ is proportional to h 2 /J[j (j + 1) -Ω (Ω + 1)]/sup 1/2/ and therefore is particularly significant in the nuclei with large j and low Ω Nilsson levels close to Fermi surface: n(i/sub 13/2/) in A = 150 to 170 rare-earth nuclei and p(i/sub 13/2/) and n(j/sub 15/2/) in A greater than or equal to 224 actinide nuclei. Because of larger j (n(j/sub 15/2/) versus n(i/sub 13/2/)) and smaller deformations (β approx. = 0.22 versus β 0.28) it was reasonable to expect that in actinide nuclei Coriolis effects are stronger than in the rare earth nuclei. Recently it was realized that the strength of observed Coriolis effects depends not only on the genuine Coriolis Coupling but also on the interplay between Coriolis ad pairing forces which leads to an interference between the wave functions of two mixing rotational bands. As a consequence the effective interaction V/sub eff/ of both bands is an oscillating function of the degree of shell filling (or chemical potential lambda F). It was shown that in the rare earth nuclei this interference strongly influenced conclusions about the trends in the Coriolis coupling strength and explained many of the observed band-mixing features (the sharpness of back banding curves, details of the blocking effect etc.). From theoretical analysis it was concluded that in the majority of actinide nuclei the effective interaction V/sub eff/ is strong, and therefore the Coriolis band-mixing have to be very strong. In this paper we would like to demonstrate that contrary to these predictions experimental data suggest that Coriolis band mixing in studied actinide nuclei is relatively weak and possibly significantly weaker than in rare earth nuclei

The cell nuclei of skeletal muscle cells are transcriptionally active in hibernating edible dormice

Directory of Open Access Journals (Sweden)

Muller Sylviane

2009-03-01

Full Text Available Abstract Background Skeletal muscle is able to react in a rapid, dynamic way to metabolic and mechanical stimuli. In particular, exposure to either prolonged starvation or disuse results in muscle atrophy. At variance, in hibernating animals muscle atrophy may be scarce or absent after bouts of hibernation i.e., periods of prolonged (months inactivity and food deprivation, and muscle function is fully preserved at arousal. In this study, myocytes from the quadriceps muscle of euthermic and hibernating edible dormice were investigated by a combination of morphological, morphometrical and immunocytochemical analyses at the light and electron microscopy level. The focus was on cell nuclei and mitochondria, which are highly sensitive markers of changing metabolic rate. Results Findings presented herein demonstrate that: 1 the general histology of the muscle, inclusive of muscle fibre shape and size, and the ratio of fast and slow fibre types are not affected by hibernation; 2 the fine structure of cytoplasmic and nuclear constituents is similar in euthermia and hibernation but for lipid droplets, which accumulate during lethargy; 3 during hibernation, mitochondria are larger in size with longer cristae, and 4 myonuclei maintain the same amount and distribution of transcripts and transcription factors as in euthermia. Conclusion In this study we demonstrate that skeletal muscle cells of the hibernating edible dormouse maintain their structural and functional integrity in full, even after months in the nest. A twofold explanation for that is envisaged: 1 the maintenance, during hibernation, of low-rate nuclear and mitochondrial activity counterbalancing myofibre wasting, 2 the intensive muscle stimulation (shivering during periodic arousals in the nest, which would mimic physical exercise. These two factors would prevent muscle atrophy usually occurring in mammals after prolonged starvation and/or inactivity as a consequence of prevailing catabolism

Monopole transitions in hot nuclei

Energy Technology Data Exchange (ETDEWEB)

Sujkowski, Z. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

1994-12-31

Monopole transitions can be a signature of shape changing in a hot, pulsating nucleus (the low energy E0 mode) and/or a measure of the compressibility of finite nuclei (GMR, the breathing mode). Experimental information pertaining to GMR is reviewed. Recipes for deducing the incompressibility modules for infinite nuclear matter from data on GMR are discussed. Astrophysical implications are outlined. The first attempts at locating the GMR strength in moderately hot nuclei are described. Prospects for improving the experimental techniques to make an observation of this strength in selected nuclei unambiguous are discussed. (author). 46 refs, 8 figs.

Monopole transitions in hot nuclei

International Nuclear Information System (INIS)

Sujkowski, Z.

1994-01-01

Monopole transitions can be a signature of shape changing in a hot, pulsating nucleus (the low energy E0 mode) and/or a measure of the compressibility of finite nuclei (GMR, the breathing mode). Experimental information pertaining to GMR is reviewed. Recipes for deducing the incompressibility modules for infinite nuclear matter from data on GMR are discussed. Astrophysical implications are outlined. The first attempts at locating the GMR strength in moderately hot nuclei are described. Prospects for improving the experimental techniques to make an observation of this strength in selected nuclei unambiguous are discussed. (author). 46 refs, 8 figs

Cavitation inception from bubble nuclei

DEFF Research Database (Denmark)

Mørch, Knud Aage

2015-01-01

, and experimental investigations of bubbles and cavitation inception have been presented. These results suggest that cavitation nuclei in equilibrium are gaseous voids in the water, stabilized by a skin which allows diffusion balance between gas inside the void and gas in solution in the surrounding liquid....... The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure-time history of the water. A recent model...

Hydroxyurea Treatment and Development of the Rat Cerebellum: Effects on the Neurogenetic Profiles and Settled Patterns of Purkinje Cells and Deep Cerebellar Nuclei Neurons.

Science.gov (United States)

Martí, Joaquín; Santa-Cruz, M C; Serra, Roger; Hervás, José P

2016-11-01

The current paper analyzes the development of the male and female rat cerebellum exposed to hydroxyurea (HU) (300 or 600 mg/kg) as embryo and collected at postnatal day 90. Our study reveals that the administration of this drug compromises neither the cytoarchitecture of the cerebellar cortex nor deep nuclei (DCN). However, in comparison with the saline group, we observed that several cerebellar parameters were lower in the HU injected groups. These parameters included area of the cerebellum, cerebellar cortex length, molecular layer area, Purkinje cell number, granule cell counts, internal granular layer, white matter and cerebellar nuclei areas, and number of deep cerebellar nuclei neurons. These features were larger in the rats injected with saline, smaller in those exposed to 300 mg/kg of HU and smallest in the group receiving 600 mg/kg of this agent. No sex differences in the effect of the HU were observed. In addition, we infer the neurogenetic timetables and the neurogenetic gradients of PCs and DCN neurons in rats exposed to either saline or HU as embryos. For this purpose, 5-bromo-2'-deoxyuridine was injected into pregnant rats previously administered with saline or HU. This thymidine analog was administered following a progressively delayed cumulative labeling method. The data presented here show that systematic differences exist in the pattern of neurogenesis and in the spatial location of cerebellar neurons between rats injected with saline or HU. No sex differences in the effect of the HU were observed. These findings have implications for the administration of this compound to women in gestation as the effects of HU on the development of the cerebellum might persist throughout their offsprings' life.

Interspecies somatic cell nuclear transfer in Asiatic cheetah using nuclei derived from post-mortem frozen tissue in absence of cryo-protectant and in vitro matured domestic cat oocytes.

Science.gov (United States)

Moulavi, F; Hosseini, S M; Tanhaie-Vash, N; Ostadhosseini, S; Hosseini, S H; Hajinasrollah, M; Asghari, M H; Gourabi, H; Shahverdi, A; Vosough, A D; Nasr-Esfahani, M H

2017-03-01

Recent accomplishments in the field of somatic cell nuclear transfer (SCNT) hold tremendous promise to prevent rapid loss of animal genetic resources using ex situ conservation technology. Most of SCNT studies use viable cells for nuclear transfer into recipient oocytes. However, preparation of live cells in extreme circumstances, in which post-mortem material of endangered/rare animals is improperly retained frozen, is difficult, if not impossible. This study investigated the possibility of interspecies-SCNT (iSCNT) in Asiatic cheetah (Acinonyx jubatus venaticus), a critically endangered subspecies, using nuclei derived from frozen tissue in absence of cryo-protectant at -20 °C and in vitro matured domestic cat oocytes. No cells growth was detected in primary culture of skin and tendon pieces or following culture of singled cells prepared by enzymatic digestion. Furthermore, no live cells were detected following differential viable staining and almost all cells had ruptured membrane. Therefore, direct injection of donor nuclei into enucleated cat oocytes matured in vitro was carried out for SCNT experiments. Early signs of nuclear remodeling were observed as early as 2 h post-iSCNT and significantly increased at 4 h post-iSCNT. The percentages of iSCNT reconstructs that cleaved and developed to 4-16 cell and morula stages were 32.3 ± 7.3, 18.2 ± 9.8 and 5.9 ± 4.3%, respectively. However, none of the iSCNT reconstructs developed to the blastocyst stage. When domestic cat somatic and oocytes were used for control SCNT and parthenogenetic activation, the respective percentages of oocytes that cleaved (51.3 ± 13.9 and 77.3 ± 4.0%) and further developed to the blastocyst stage (11.3 ± 3.3 and 16.8 ± 3.8%) were comparable. In summary, this study demonstrated that enucleated cat oocytes can partially remodel and reactivate non-viable nuclei of Asiatic cheetah and support its reprogramming back to the embryonic stage. To our knowledge, this is

Electron-microscope study of cloud and fog nuclei

Energy Technology Data Exchange (ETDEWEB)

Ogiwara, S; Okita, T

1952-01-01

Droplets of clouds on a mountain and of fog in an urban area were captured and the form, nature and size of their nuclei were studied by means of an electron-microscope and by a chamber of constant humidity. These nuclei have similar form and nature to the hygroscopic particles in haze and to the artificially produced combustion particles. No sea-salt nuclei were found in our observations, therefore, sea-spray appears to be an insignificant source of condensation nuclei. It was found that both the cloud and the fog nuclei originated in combustion products which were the mixture of hygroscopic and non-hygroscopic substances, and that the greater part of the nuclei did not contain pure sulfuric acid.

Quarks in nuclei

International Nuclear Information System (INIS)

Rho, M.; CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette

1983-01-01

Some features of quark degrees of freedom in nuclei are discussed in the light of recent developments in QCD. The principal aim of this talk is to propose, and give a tentative support to, the motion that one can study through nuclear matter different facets of the vacuum structure implied by quantum chromodynamics (QCD). This will be done using the recent (exciting) results obtained in particle physics, in particular lattice gauge calculations. Relevance of this aspect of problem to quark degrees of freedom as well as meson degrees of freedom in nuclei will be discussed. (orig.)

Hemispheric aerosol vertical profiles: anthropogenic impacts on optical depth and cloud nuclei.

Science.gov (United States)

Clarke, Antony; Kapustin, Vladimir

2010-09-17

Understanding the effect of anthropogenic combustion upon aerosol optical depth (AOD), clouds, and their radiative forcing requires regionally representative aerosol profiles. In this work, we examine more than 1000 vertical profiles from 11 major airborne campaigns in the Pacific hemisphere and confirm that regional enhancements in aerosol light scattering, mass, and number are associated with carbon monoxide from combustion and can exceed values in unperturbed regions by more than one order of magnitude. Related regional increases in a proxy for cloud condensation nuclei (CCN) and AOD imply that direct and indirect aerosol radiative effects are coupled issues linked globally to aged combustion. These profiles constrain the influence of combustion on regional AOD and CCN suitable for challenging climate model performance and informing satellite retrievals.

Muscle Fiber Characteristics, Satellite Cells and Soccer Performance in Young Athletes

Directory of Open Access Journals (Sweden)

Thomas I. Metaxas, Athanasios Mandroukas, Efstratios Vamvakoudis, Kostas Kotoglou, Björn Ekblom, Konstantinos Mandroukas

2014-09-01

Full Text Available This study is aimed to examine the muscle fiber type, composition and satellite cells in young male soccer players and to correlate them to cardiorespiratory indices and muscle strength. The participants formed three Groups: Group A (n = 13, 11.2 ± 0.4yrs, Group B (n=10, 13.1 ± 0.5yrs and Group C (n = 9, 15.2 ± 0.6yrs. Muscle biopsies were obtained from the vastus lateralis. Peak torque values of the quadriceps and hamstrings were recorded and VO2max was measured on the treadmill. Group C had lower type I percentage distribution compared to A by 21.3% (p < 0.01, while the type IIA relative percentage was higher by 18.1% and 18.4% than in Groups A and B (p < 0.05. Groups B and C had higher cross-sectional area (CSA values in all fiber types than in Group A (0.05 < p < 0.001. The number of satellite cells did not differ between the groups. Groups B and C had higher peak torque at all angular velocities and absolute VO2max in terms of ml·min-1 than Group A (0.05 < p < 0.001. It is concluded that the increased percentage of type IIA muscle fibers noticed in Group C in comparison to the Groups A and B should be mainly attributed to the different workload exercise and training programs. The alteration of myosin heavy chain (MHC isoforms composition even in children is an important mechanism for skeletal muscle characteristics. Finally, CSA, isokinetic muscle strength and VO2max values seems to be expressed according to age.

Influence of exercise contraction mode and protein supplementation on human skeletal muscle satellite cell content and muscle fiber growth

DEFF Research Database (Denmark)

Farup, Jean; Rahbek, Stine Klejs; Riis, Simon

2014-01-01

-specific association between emergence of satellite cells (SCs), muscle growth, and remodeling in response to 12 wk unilateral resistance training performed as eccentric (Ecc) or concentric (Conc) resistance training ± whey protein (Whey, 19.5 g protein + 19.5 g glucose) or placebo (Placebo, 39 g glucose......Skeletal muscle satellite cells (SCs) are involved in remodeling and hypertrophy processes of skeletal muscle. However, little knowledge exists on extrinsic factors that influence the content of SCs in skeletal muscle. In a comparative human study, we investigated the muscle fiber type......) supplementation. Muscle biopsies (vastus lateralis) were analyzed for fiber type-specific SCs, myonuclei, and fiber cross-sectional area (CSA). Following training, SCs increased with Conc in both type I and type II fibers (P

Highly multiplexed targeted DNA sequencing from single nuclei.

Science.gov (United States)

Leung, Marco L; Wang, Yong; Kim, Charissa; Gao, Ruli; Jiang, Jerry; Sei, Emi; Navin, Nicholas E

2016-02-01

Single-cell DNA sequencing methods are challenged by poor physical coverage, high technical error rates and low throughput. To address these issues, we developed a single-cell DNA sequencing protocol that combines flow-sorting of single nuclei, time-limited multiple-displacement amplification (MDA), low-input library preparation, DNA barcoding, targeted capture and next-generation sequencing (NGS). This approach represents a major improvement over our previous single nucleus sequencing (SNS) Nature Protocols paper in terms of generating higher-coverage data (>90%), thereby enabling the detection of genome-wide variants in single mammalian cells at base-pair resolution. Furthermore, by pooling 48-96 single-cell libraries together for targeted capture, this approach can be used to sequence many single-cell libraries in parallel in a single reaction. This protocol greatly reduces the cost of single-cell DNA sequencing, and it can be completed in 5-6 d by advanced users. This single-cell DNA sequencing protocol has broad applications for studying rare cells and complex populations in diverse fields of biological research and medicine.

Investigating the spectral characteristics of backscattering from heterogeneous spheroidal nuclei using broadband finite-difference time-domain simulations

Science.gov (United States)

Chao, Guo-Shan; Sung, Kung-Bin

2010-02-01

Backscattered light spectra have been used to extract size distribution of cell nuclei in epithelial tissues for noninvasive detection of precancerous lesions. In existing experimental studies, size estimation is achieved by assuming nuclei as homogeneous spheres or spheroids and fitting the measured data with models based on Mie theory. However, the validity of simplifying nuclei as homogeneous spheres has not been thoroughly examined. In this study, we investigate the spectral characteristics of backscattering from models of spheroidal nuclei under plane wave illumination using three-dimensional finite-difference time-domain (FDTD) simulation. A modulated Gaussian pulse is used to obtain wavelength dependent scattering intensity with a single FDTD run. The simulated model of nuclei consists of a nucleolus and randomly distributed chromatin condensation in homogeneous cytoplasm and nucleoplasm. The results show that backscattering spectra from spheroidal nuclei have similar oscillating patterns to those from homogeneous spheres with the diameter equal to the projective length of the spheroidal nucleus along the propagation direction. The strength of backscattering is enhanced in heterogeneous spheroids as compared to homogeneous spheroids. The degree of which backscattering spectra of heterogeneous nuclei deviate from Mie theory is highly dependent on the distribution of chromatin/nucleolus but not sensitive to nucleolar size, refractive index fluctuation or chromatin density.

Microdosimetry of haemopoietic stem cells irradiated by α particles from the short-lived products of 222Rn decays in fat cells and haemopoietic tissue

International Nuclear Information System (INIS)

Charlton, D.E.; Utteridge, T.D.; University of South Australia, Pooraka, SA; Beddoe, A.H.

1996-01-01

The Monte Carlo method is used to model fat cells and the nuclei of stem cells in haemopoietic tissue where 222 Rn is dissolved in different amounts in the fat and tissue. Calculations are performed for fat cells of diameters 50 and 100 μm and for stem cell nuclei of 8 and 16 μm diameters for various fractions of fat filling the volume. Average doses (and their distributions) to stem cell nuclei from single passages of α particles are presented. In addition to dose, the relationship between LET and dose is obtained, illustrating the importance of 'stoppers' in the calculations. The annual average dose equivalent for a concentration of 1 Bq/m 3 in air agrees well with other authors at 12 μSv/year. The method also allows the calculation of the fraction of stem cell nuclei hit annually. Here for 1 Bq/m 3 , stem cell nuclei of diameter 8 μm and 100% fat filing 15 x 10 -7 of the stem cell nuclei are hit. (Author)

Fiber type specific response of skeletal muscle satellite cells to high-intensity resistance training in dialysis patients

DEFF Research Database (Denmark)

Molsted, Stig; Andersen, Jesper Løvind; Harrison, Adrian Paul

2015-01-01

Introduction. The aim was to investigate the effect of high-intensity resistance training on satellite cell (SC) and myonuclear number in the muscle of patients undergoing dialysis. Methods. Patients (n=21) underwent a 16-week control period, followed by 16 weeks of resistance training thrice...

The dynamics of the nuclei-nuclei interactions at very high energies

International Nuclear Information System (INIS)

Blaizot, J.P.

1988-01-01

The lectures on the dynamics of nuclei-nuclei interactions at very high energies, presented in the Summer School on Nuclear Physics and Particle Physics (1988), are shown. The equation of state of the hadronic matter is analyzed, by means of simple models, and some orders of magnitude can be asserted. The main characteristics of the high energy hadronic interactions are recalled. The basis of the dynamics of the relativistic fluids are given. Applications of this dynamics in the description of the space-time evolution of a plasma, generated by heavy ions collision, are carried out [fr

Age of heart disease presentation and dysmorphic nuclei in patients with LMNA mutations.

Science.gov (United States)

Core, Jason Q; Mehrabi, Mehrsa; Robinson, Zachery R; Ochs, Alexander R; McCarthy, Linda A; Zaragoza, Michael V; Grosberg, Anna

2017-01-01

Nuclear shape defects are a distinguishing characteristic in laminopathies, cancers, and other pathologies. Correlating these defects to the symptoms, mechanisms, and progression of disease requires unbiased, quantitative, and high-throughput means of quantifying nuclear morphology. To accomplish this, we developed a method of automatically segmenting fluorescently stained nuclei in 2D microscopy images and then classifying them as normal or dysmorphic based on three geometric features of the nucleus using a package of Matlab codes. As a test case, cultured skin-fibroblast nuclei of individuals possessing LMNA splice-site mutation (c.357-2A>G), LMNA nonsense mutation (c.736 C>T, pQ246X) in exon 4, LMNA missense mutation (c.1003C>T, pR335W) in exon 6, Hutchinson-Gilford Progeria Syndrome, and no LMNA mutations were analyzed. For each cell type, the percentage of dysmorphic nuclei, and other morphological features such as average nuclear area and average eccentricity were obtained. Compared to blind observers, our procedure implemented in Matlab codes possessed similar accuracy to manual counting of dysmorphic nuclei while being significantly more consistent. The automatic quantification of nuclear defects revealed a correlation between in vitro results and age of patients for initial symptom onset. Our results demonstrate the method's utility in experimental studies of diseases affecting nuclear shape through automated, unbiased, and accurate identification of dysmorphic nuclei.

Electric monopole transitions from low energy excitations in nuclei

CERN Document Server

Wood, J L; De Coster, C; Heyde, Kris L G

1999-01-01

Electric monopole (E0) properties are studied across the entire nuclear mass surface. Besides an introductory discussion of various model results (shell model, geometric vibrational and rotational models, algebraic models), we point out that many of the largest E0 transition strengths, $\\rho^2$(E0), are associated with shape mixing. We discuss in detail the manifestation of E0 transitions and present extensive data for~: single-closed shell nuclei, vibrational nuclei, well-deformed nuclei, nuclei that exhibit sudden ground-state changes, and nuclei that exhibit shape coexistence and intruder states. We also give attention to light nuclei, odd-A nuclei, and illustrate a suggested relation between $\\rho^2$(E0) and isotopic shifts.

Effect of low dose radiation on thymocyte cytosol and nuclei protein synthesis in mice

International Nuclear Information System (INIS)

Meng Qingyong; Chen Shali; Liu Shuzheng

2003-01-01

Objective: To the effect of low dose radiation on thymocyte cytosol and nuclei protein synthesis in mice. Methods: The expression of proteins was analyzed by gel filtration with Sephadex G-100 and HPLC based on separation of proteins on thymocyte cytosol and nuclei after whole-body irradiation with 75 mGy X-rays and sham-irradiation, and their biological activity was examined by mouse splenocyte proliferation and chromosome aberration of human peripheral blood lymphocytes. Results: HPLC analysis showed that there was a marked increase in expression of 61.4 kD protein in the extract of thymocyte cytosol and 30.4 kD protein in the extract of thymocyte nuclei in comparison with the corresponding fractions from the sham-irradiated control mice. These protein fractions from the thymocyte cytosol and nuclei of the irradiated mice showed both stimulating effect on normal T cell proliferation and protective effect on chromosome damage induced by high dose radiation. Conclusion: These findings might have implications in study of mechanism of immunoenhancement and cytogenetic adaptive response induced by low dose radiation

Characterization of rat primary trigeminal satellite glial cells and associated extracellular vesicles under normal and inflammatory conditions

DEFF Research Database (Denmark)

Vinterhøj, Hye Sook Han; Stensballe, Allan; Duroux, Meg

2018-01-01

Satellite glial cells (SGCs) in sensory ganglia contribute to the pathogenesis of chronic pain, potentially through mediating extracellular or paracrine signaling. Recently, extracellular vesicles (EVs) in the form of exosomes have been found to play an important role in cell-cell communication....... Results demonstrated that SGCs shed vesicles in the size range of exosomes (>150 nm) but with altered protein expression upon LPS-activation. Proteomic profiling of SGCs-shed EVs showed that a number of proteins were differentially regulated upon LPS stimulation such as junction plakoglobin and myosin 9...

Improved and Reproducible Flow Cytometry Methodology for Nuclei Isolation from Single Root Meristem

Directory of Open Access Journals (Sweden)

Thaís Cristina Ribeiro Silva

2010-01-01

Full Text Available Root meristems have increasingly been target of cell cycle studies by flow cytometric DNA content quantification. Moreover, roots can be an alternative source of nuclear suspension when leaves become unfeasible and for chromosome analysis and sorting. In the present paper, a protocol for intact nuclei isolation from a single root meristem was developed. This proceeding was based on excision of the meristematic region using a prototypical slide, followed by short enzymatic digestion and mechanical isolation of nuclei during homogenization with a hand mixer. Such parameters were optimized for reaching better results. Satisfactory nuclei amounts were extracted and analyzed by flow cytometry, producing histograms with reduced background noise and CVs between 3.2 and 4.1%. This improved and reproducible technique was shown to be rapid, inexpensive, and simple for nuclear extraction from a single root tip, and can be adapted for other plants and purposes.

Symmetry energy, unstable nuclei and neutron star crusts

Energy Technology Data Exchange (ETDEWEB)

Iida, Kei [Kochi University, Department of Natural Science, Kochi (Japan); RIKEN Nishina Center, Saitama (Japan); Oyamatsu, Kazuhiro [RIKEN Nishina Center, Saitama (Japan); Aichi Shukutoku University, Department of Human Informatics, Aichi (Japan)

2014-02-15

The phenomenological approach to inhomogeneous nuclear matter is useful to describe fundamental properties of atomic nuclei and neutron star crusts in terms of the equation of state of uniform nuclear matter. We review a series of researches that we have developed by following this approach. We start with more than 200 equations of state that are consistent with empirical masses and charge radii of stable nuclei and then apply them to describe matter radii and masses of unstable nuclei, proton elastic scattering and total reaction cross sections off unstable nuclei, and nuclei in neutron star crusts including nuclear pasta. We finally discuss the possibility of constraining the density dependence of the symmetry energy from experiments on unstable nuclei and even observations of quasi-periodic oscillations in giant flares of soft gamma-ray repeaters. (orig.)

Using satellite-based measurements to explore ...

Science.gov (United States)

New particle formation (NPF) can potentially alter regional climate by increasing aerosol particle (hereafter particle) number concentrations and ultimately cloud condensation nuclei. The large scales on which NPF is manifest indicate potential to use satellite-based (inherently spatially averaged) measurements of atmospheric conditions to diagnose the occurrence of NPF and NPF characteristics. We demonstrate the potential for using satellite-measurements of insolation (UV), trace gas concentrations (sulfur dioxide (SO2), nitrogen dioxide (NO2), ammonia (NH3), formaldehyde (HCHO), ozone (O3)), aerosol optical properties (aerosol optical depth (AOD), Ångström exponent (AE)), and a proxy of biogenic volatile organic compound emissions (leaf area index (LAI), temperature (T)) as predictors for NPF characteristics: formation rates, growth rates, survival probabilities, and ultrafine particle (UFP) concentrations at five locations across North America. NPF at all sites is most frequent in spring, exhibits a one-day autocorrelation, and is associated with low condensational sink (AOD×AE) and HCHO concentrations, and high UV. However, there are important site-to-site variations in NPF frequency and characteristics, and in which of the predictor variables (particularly gas concentrations) significantly contribute to the explanatory power of regression models built to predict those characteristics. This finding may provide a partial explanation for the reported spatia

Cluster structure in Cf nuclei

International Nuclear Information System (INIS)

Singh, Shailesh K.; Biswal, S.K.; Bhuyan, M.; Patra, S.K.; Gupta, R.K.

2014-01-01

Due to the availability of advance experimental facilities, it is possible to probe the nuclei upto their nucleon level very precisely and analyzed the internal structure which will help us to resolve some mysterious problem of the decay of nuclei. Recently, the relativistic nuclear collision, confirmed the α cluster type structure in the 12 C which is the mile stone for the cluster structure in nuclei. The clustering phenomena in light and intermediate elements in nuclear chart is very interesting. There is a lot of work done by our group in the clustering behaviour of the nuclei. In this paper, the various prospectus of clustering in the isotopes of Cf nucleus including fission state is discussed. Here, 242 Cf isotope for the analysis, which is experimentally known is taken. The relativistic mean field model with well established NL3 parameter set is taken. For getting the exact ground state configuration of the isotopes, the calculation for minimizing the potential energy surface is performed by constraint method. The clustering structure of other Cf isotopes is discussed

Critical and shape-unstable nuclei

CERN Document Server

Cailliau, M; Husson, J P; Letessier, J; Mang, H J

1973-01-01

The authors' experimental work on the decay of neutron deficient mercury osmium nuclei, some other studies at ISOLDE (CERN) and their first theoretical analysis show that the nuclei around /sup 186/Pt (Z=78, N=108) are at the limit of spherical, oblate, prolate nuclei, have (the even one) their first 0/sup +/ excited states at very low energy; quasi- rotational bands are associated to these states. The energy of this O/sup +/ state in /sup 186-/Pt deviate from the Kumar value: angular shape instability is not enough to explain this result. The authors look at radial shape and pairing fluctuations. The position of the 4p-4n state must also be known. (0 refs).

Protonic decay of oriented nuclei

International Nuclear Information System (INIS)

Kadmensky, S.G.

2002-01-01

On the basis of the multiparticle theory of protonic decay, the angular distributions of protons emitted by oriented spherical and deformed nuclei in the laboratory frame and in the internal coordinate frame of deformed parent nuclei are constructed with allowance for symmetry with respect to time inversion. It is shown that, because of the deep-subbarrier character of protonic decay, the adiabatic approximation is not applicable to describing the angular distributions of protons emitted by oriented deformed nuclei and that the angular distribution of protons in the laboratory frame does not coincide with that in the internal coordinate frame. It is demonstrated that these angular distributions coincide only if the adiabatic and the semiclassical approximation are simultaneously valid

Coulomb energy differences in mirror nuclei

International Nuclear Information System (INIS)

Lenzi, Silvia M

2006-01-01

By comparing the excitation energies of analogue states in mirror nuclei, several nuclear structure properties can be studied as a function of the angular momentum up to high spin states. They can be described in the shell model framework by including electromagnetic and nuclear isospin-non-conserving interactions. Calculations for the mirror energy differences in nuclei of the f 7/2 shell are described and compared with recent experimental data. These studies are extended to mirror nuclei in the upper sd and fp shells

Is there chirality in atomic nuclei?

International Nuclear Information System (INIS)

Meng Jie

2009-01-01

Static chiral symmetries are common in nature, for example, the macroscopic spirals of snail shells, the microscopic handedness of certain molecules, and human hands. The concept of chirality in atomic nuclei was first proposed in 1997, and since then many efforts have been made to understand chiral symmetry and its spontaneous breaking in atomic nuclei. Recent theoretical and experimental progress in the verification of chirality in atomic nuclei will be reviewed, together with a discussion of the problems that await to be solved in the future. (authors)

Solar photovoltaic research and development program of the Air Force Aero Propulsion Laboratory. [silicon solar cell applicable to satellite power systems

Science.gov (United States)

Wise, J.

1979-01-01

Progress is reported in the following areas: laser weapon effects, solar silicon solar cell concepts, and high voltage hardened, high power system technology. Emphasis is placed on solar cells with increased energy conversion efficiency and radiation resistance characteristics for application to satellite power systems.

3D Segmentations of Neuronal Nuclei from Confocal Microscope Image Stacks

Directory of Open Access Journals (Sweden)

Antonio eLaTorre

2013-12-01

Full Text Available In this paper, we present an algorithm to create 3D segmentations of neuronal cells from stacks of previously segmented 2D images. The idea behind this proposal is to provide a general method to reconstruct 3D structures from 2D stacks, regardless of how these 2D stacks have been obtained. The algorithm not only reuses the information obtained in the 2D segmentation, but also attempts to correct some typical mistakes made by the 2D segmentation algorithms (for example, under segmentation of tightly-coupled clusters of cells. We have tested our algorithm in a real scenario --- the segmentation of the neuronal nuclei in different layers of the rat cerebral cortex. Several representative images from different layers of the cerebral cortex have been considered and several 2D segmentation algorithms have been compared. Furthermore, the algorithm has also been compared with the traditional 3D Watershed algorithm and the results obtained here show better performance in terms of correctly identified neuronal nuclei.

Study of the experimental data of multifragmentation of gold and krypton nuclei on interactions with photoemulsion nuclei at high energies

International Nuclear Information System (INIS)

Saleh, Z.A.; Abdel-Hafez, A.

2002-01-01

Results from EMU-01/12 collaboration for the experimental data on multifragmentation of gold residual nuclei created in the interactions with photoemulsion nuclei at the energy of 10.7 GeV/nucleon are presented together with the experimental data on multifragmentation of krypton created on the interactions with photoemulsion nuclei at energy of 0.9 GeV/nucleon. The data are analyzed in the frame of the statistical model of multifragmentation. It is obvious that there are two regimes for nuclear multifragmentation: the former is when less than one-half of nucleons of projectile nucleus are knocked out, the later is when more than one-half of nucleons are knocked out. Residual nuclei with masses close to each other created at different reactions are fragmented practically simultaneously when more than one-half of nucleons of original nuclei are knocked out. These results give an indication that projectiles other than Gold and Krypton may give the same characterization on interaction with emulsion nuclei at high energies

Spectroscopy of very heavy nuclei with a view to study super-heavy nuclei

International Nuclear Information System (INIS)

Khalfallah, F.

2007-08-01

Within the recent years, the spectroscopic study of single particle orbitals of very heavy elements (VHE) has become possible with the development of increasingly efficient experimental setups. This allows us, through nuclear deformation, to access with these deformed nuclei to orbitals situated around the Fermi level in the spherical superheavy elements (SHE) and learn more about the nuclear structure of these nuclei. The aim of this work is the spectroscopic studies of heavy and very heavy elements. Because of the experimental difficulties associated with the fusion reactions in the VHE region, a detailed optimization studies is essential. Simulation of energy loss and angular straggling of these nuclei due to the interaction in the target and to neutron's evaporation was carried out and allowed us to optimize the angular acceptance of the separators according to the target thickness. An extensive survey and exploration in the VHE region was also conducted on the basis of cross section's systematics in the literature and simulations carried out using the statistical code Hivap. In this framework, the possible extension of the range of validity of a set of Hivap parameters was investigated. This work has enabled us to prepare a list of experiments of interest for the production of very heavy nuclei. In this thesis, our work was concentrated on the spectroscopy of the nuclei No 256 et Rf 256 for which two experimental proposals were accepted. The octupole deformations predicted in the actinides region is studied in another part of this thesis, a part witch is dedicated to the gamma spectroscopy of Pa 223 . The data from a new experiment carried out using the Jurogam-Ritu-Great setup are analysed and compared to previous results. They confirm the octupole deformed shape in this nucleus. (author)

Hot nuclei and fragmentation

International Nuclear Information System (INIS)

Guerreau, D.

1993-01-01

A review is made of the present status concerning the production of nuclei above 5 MeV temperature. Considerable progress has been made recently on the understanding of the formation and the fate of such hot nuclei. It appears that the nucleus seems more stable against temperature than predicted by static calculations. However, the occurrence of multifragment production at high excitation energies is now well established. The various experimental features of the fragmentation process are discussed. (author) 59 refs., 12 figs

Immunocytochemical demonstration of polyamines in nucleoli and nuclei

DEFF Research Database (Denmark)

Shin, Masashi; Nakamuta, Hiromichi; Oda-Ueda, Naoko

2008-01-01

in both nucleoli and nuclei of a variety of cell types. Detection of nucleolar and nuclear PAs required novel pretreatment procedures involving protease and/or DNase digestion of specimens prior to immunoreaction. Double fluorescence staining confirmed the localizations. This suggests that PAs may...... be important to the formation of ribosomes in nucleoli, as well as adds support to biochemical studies suggesting that PAs are involved in many biological events in the nucleus. Further biochemical studies will be needed to substantiate this hypothesis....

Space satellite power system. [conversion of solar energy by photovoltaic solar cell arrays

Science.gov (United States)

Glaser, P. E.

1974-01-01

The concept of a satellite solar power station was studied. It is shown that it offers the potential to meet a significant portion of future energy needs, is pollution free, and is sparing of irreplaceable earth resources. Solar energy is converted by photovoltaic solar cell arrays to dc energy which in turn is converted into microwave energy in a large active phased array. The microwave energy is beamed to earth with little attenuation and is converted back to dc energy on the earth. Economic factors are considered.

Major new sources of biological ice nuclei

Science.gov (United States)

Moffett, B. F.; Hill, T.; Henderson-Begg, S. K.

2009-12-01

Almost all research on biological ice nucleation has focussed on a limited number of bacteria. Here we characterise several major new sources of biogenic ice nuclei. These include mosses, hornworts, liverworts and cyanobacteria. Ice nucleation in the eukaryotic bryophytes appears to be ubiquitous. The temperature at which these organisms nucleate is that at which the difference in vapour pressure over ice and water is at or close to its maximum. At these temperatures (-8 to -18 degrees C) ice will grow at the expense of supercooled water. These organisms are dependent for their water on occult precipitation - fog, dew and cloudwater which by its nature is not collected in conventional rain gauges. Therefore we suggest that these organism produce ice nuclei as a water harvesting mechanism. Since the same mechanism would also drive the Bergeron-Findeisen process, and as moss is known to become airborne, these nuclei may have a role in the initiation of precipitation. The properties of these ice nuclei are very different from the well characterised bacterial nuclei. We will also present DNA sequence data showing that, although related, the proteins responsible are only very distantly related to the classical bacterial ice nuclei.

Structure and clusters of light unstable nuclei

International Nuclear Information System (INIS)

En'yo, Yoshiko

2010-01-01

As it is known, cluster structures are often observed in light nuclei. In the recent evolution of unstable nuclear research (on nuclei having unbalanced number of neutron and proton) further new types of clusters are coming to be revealed. In this report, structures of light unstable nuclei and some of the theoretical models to describe them are reviewed. The following topics are picked up. 1. Cluster structure and theoretical models, 2. Cluster structure of unstable nuclei (low excited state). 3. Cluster structure of neutron excess beryllium isotopes. 4. Cluster gas like state in C isotope. 5. Dineutron structure of He isotopes. Numbers of strange nuclear structures of light nuclei are illustrated. Antisymmetrized molecular dynamics (AMD) is the recently developed theoretical framework which has been successfully used in heavy ion reactions and nuclear structure studies. Successful application of AMD to the isotopes of Be, B and C are illustrated. (S. Funahashi)

Perturbative many-body approaches to finite nuclei

International Nuclear Information System (INIS)

Hjort-Jensen, M.; Engeland, T.; Holt, A.; Osnes, E.

1992-06-01

In this work the authors discuss various approaches to the effective interaction appropriate for finite nuclei. The methods reviewed are the folded-diagram method of Kuo and co-workers and the summation of the folded diagrams as advocated by Lee and Suzuki. Examples of applications to sd-shell nuclei from previous works are discussed together with hitherto unpublished results for nuclei in pf-shell. Since the method of Lee and Suzuki is found to yield the best converged results, this method is applied to calculate the effective interaction for nuclei in the pf-shell. For the calculation of the effective interaction, three recent versions of the Bonn meson-exchange potential model have been used. These versions are fitted to the same set of data and differ only in the strength of the tensor force. The importance of the latter for finite nuclei is discussed. 67 refs., 17 figs., 7 tabs

A new spin-oriented nuclei facility: POLAREX

Directory of Open Access Journals (Sweden)

Etilé A.

2014-03-01

Full Text Available Using the On-Line Nuclear Orientation method, POLAREX (POLARization of EXotic nuclei is a new facility allowing to study the anisotropic decay of spin-oriented nuclei. Based on the combination of on-line implantation of radioactive nuclei with Low Temperature Nuclear Orientation technique and Nuclear Magnetic Resonance, POLAREX allows to measure nuclear electromagnetic moments and ground-state spins, in the aim to get information about the wave function composition of the nuclear state. Polarized nuclei can also be used to study fundamental interactions involving nuclear β-decay asymmetries. The POLAREX infrastructure will be installed at Accélérateur Linéaire auprés du Tandem d’Orsay in order to study neutron-rich nuclei, some of which have not been studied yet. Will be presented here, all the possibilities of this new facility and a non exhaustive scientific program.

Formation and decay of hot nuclei

International Nuclear Information System (INIS)

Tamain, B.

1992-09-01

The mechanisms involved in hot nuclei formation and decay and their eventual connexion with fundamental properties of nuclear matter are discussed, i.e. its equation of state is considered. After a brief review of the reactions in which hot nuclei can be formed, the variables which are used to describe them, the corresponding theoretical descriptions and their limits when extreme states are reached are discussed. Experimental evidences for hot nuclei formation are presented, with the corresponding decay properties used as signatures. (R.P.) 64 refs.; 25 figs.; 2 tabs

Elusive active galactic nuclei

Science.gov (United States)

Maiolino, R.; Comastri, A.; Gilli, R.; Nagar, N. M.; Bianchi, S.; Böker, T.; Colbert, E.; Krabbe, A.; Marconi, A.; Matt, G.; Salvati, M.

2003-10-01

A fraction of active galactic nuclei do not show the classical Seyfert-type signatures in their optical spectra, i.e. they are optically `elusive'. X-ray observations are an optimal tool to identify this class of objects. We combine new Chandra observations with archival X-ray data in order to obtain a first estimate of the fraction of elusive active galactic nuclei (AGN) in local galaxies and to constrain their nature. Our results suggest that elusive AGN have a local density comparable to or even higher than optically classified Seyfert nuclei. Most elusive AGN are heavily absorbed in the X-rays, with gas column densities exceeding 1024 cm-2, suggesting that their peculiar nature is associated with obscuration. It is likely that in elusive AGN the nuclear UV source is completely embedded and the ionizing photons cannot escape, which prevents the formation of a classical narrow-line region. Elusive AGN may contribute significantly to the 30-keV bump of the X-ray background.

Satellite glial cell P2Y12 receptor in the trigeminal ganglion is involved in lingual neuropathic pain mechanisms in rats

Directory of Open Access Journals (Sweden)

Katagiri Ayano

2012-03-01

Full Text Available Abstract Background It has been reported that the P2Y12 receptor (P2Y12R is involved in satellite glial cells (SGCs activation, indicating that P2Y12R expressed in SGCs may play functional roles in orofacial neuropathic pain mechanisms. However, the involvement of P2Y12R in orofacial neuropathic pain mechanisms is still unknown. We therefore studied the reflex to noxious mechanical or heat stimulation of the tongue, P2Y12R and glial fibrillary acidic protein (GFAP immunohistochemistries in the trigeminal ganglion (TG in a rat model of unilateral lingual nerve crush (LNC to evaluate role of P2Y12R in SGC in lingual neuropathic pain. Results The head-withdrawal reflex thresholds to mechanical and heat stimulation of the lateral tongue were significantly decreased in LNC-rats compared to sham-rats. These nocifensive effects were apparent on day 1 after LNC and lasted for 17 days. On days 3, 9, 15 and 21 after LNC, the mean relative number of TG neurons encircled with GFAP-immunoreactive (IR cells significantly increased in the ophthalmic, maxillary and mandibular branch regions of TG. On day 3 after LNC, P2Y12R expression occurred in GFAP-IR cells but not neuronal nuclei (NeuN-IR cells (i.e. neurons in TG. After 3 days of successive administration of the P2Y12R antagonist MRS2395 into TG in LNC-rats, the mean relative number of TG neurons encircled with GFAP-IR cells was significantly decreased coincident with a significant reversal of the lowered head-withdrawal reflex thresholds to mechanical and heat stimulation of the tongue compared to vehicle-injected rats. Furthermore, after 3 days of successive administration of the P2YR agonist 2-MeSADP into the TG in naïve rats, the mean relative number of TG neurons encircled with GFAP-IR cells was significantly increased and head-withdrawal reflex thresholds to mechanical and heat stimulation of the tongue were significantly decreased in a dose-dependent manner compared to vehicle-injected rats

Nuclei quadrupole coupling constants in diatomic molecule

International Nuclear Information System (INIS)

Ivanov, A.I.; Rebane, T.K.

1993-01-01

An approximate relationship between the constants of quadrupole interaction of nuclei in a two-atom molecule is found. It enabled to establish proportionality of oscillatory-rotation corrections to these constants for both nuclei in the molecule. Similar results were obtained for the factors of electrical dipole-quadrupole screening of nuclei. Applicability of these relationships is proven by the example of lithium deuteride molecule. 4 refs., 1 tab

Nuclei at the limits of particle stability

International Nuclear Information System (INIS)

Mueller, A.C.

1993-01-01

The properties and synthesis of nuclei at the limits of particle stability are reviewed. Nuclear reactions were induced and studied by means of the 'exotic' nuclear beams, i.e. beams of radioactive drip-line nuclei. The beams are mostly generated in heavy-ion projectile fragmentation. The cases of both neutron-rich and proton-rich nuclei are discussed. (K.A.) 270 refs.; 13 figs.; 1 tab

Size and Albedo of Irregular Saturnian Satellites from Spitzer Observations

Science.gov (United States)

Mueller, Michael; Grav, T.; Trilling, D.; Stansberry, J.; Sykes, M.

2008-09-01

Using MIPS onboard the Spitzer Space Telescope, we observed the thermal emission (24 and, for some targets, 70 um) of eight irregular satellites of Saturn: Albiorix, Siarnaq, Paaliaq, Kiviuq, Ijiraq, Tarvos, Erriapus, and Ymir. We determined the size and albedo of all targets. An analysis of archived MIPS observations of Phoebe reproduces Cassini results very accurately, thereby validating our method. For all targets, the geometric albedo is found to be low, probably below 10% and clearly below 15%. Irregular satellites are much darker than the large regular satellites. Their albedo is, however, quite similar to that of small bodies in the outer Solar System (such as cometary nuclei, Jupiter Trojans, or TNOs). This is consistent with color measurements as well as dynamical considerations which suggest a common origin of the said populations. There appear to be significant object-to-object albedo differences. Similar albedos found for some members of dynamical clusters support the idea that they may have originated in the breakup of a parent body. For three satellites, thermal data at two wavelengths are available, enabling us to constrain their thermal properties. Sub-solar temperatures are similar to that found from Cassini's Phoebe fly-by. This suggests a rather low thermal inertia, as expected for regolith-covered objects. This work is based on observations made with the Spitzer Space Telescope, which is operated by JPL under a contract with NASA. Support for this work was provided by NASA.

Perineuronal satellite neuroglia in the telencephalon of New Caledonian crows and other Passeriformes: evidence of satellite glial cells in the central nervous system of healthy birds?