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Sample records for daughter cell formation

  1. Control of daughter centriole formation by the pericentriolar material.

    PubMed

    Loncarek, Jadranka; Hergert, Polla; Magidson, Valentin; Khodjakov, Alexey

    2008-03-01

    Controlling the number of its centrioles is vital for the cell, as supernumerary centrioles cause multipolar mitosis and genomic instability. Normally, one daughter centriole forms on each mature (mother) centriole; however, a mother centriole can produce multiple daughters within a single cell cycle. The mechanisms that prevent centriole 'overduplication' are poorly understood. Here we use laser microsurgery to test the hypothesis that attachment of the daughter centriole to the wall of the mother inhibits formation of additional daughters. We show that physical removal of the daughter induces reduplication of the mother in S-phase-arrested cells. Under conditions when multiple daughters form simultaneously on a single mother, all of these daughters must be removed to induce reduplication. The number of daughter centrioles that form during reduplication does not always match the number of ablated daughter centrioles. We also find that exaggeration of the pericentriolar material (PCM) by overexpression of the PCM protein pericentrin in S-phase-arrested CHO cells induces formation of numerous daughter centrioles. We propose that that the size of the PCM cloud associated with the mother centriole restricts the number of daughters that can form simultaneously.

  2. Asymmetric Inheritance of Mother Versus Daughter Centrosome in Stem Cell Division

    PubMed Central

    Yamashita, Yukiko M.; Mahowald, Anthony P.; Perlin, Julie R.; Fuller, Margaret T.

    2007-01-01

    Adult stem cells often divide asymmetrically to produce one self-renewed stem cell and one differentiating cell, thus maintaining both populations. The asymmetric outcome of stem cell divisions can be specified by an oriented spindle and local self-renewal signals from the stem cell niche. Here we show that developmentally programmed asymmetric behavior and inheritance of mother and daughter centrosomes underlies the stereotyped spindle orientation and asymmetric outcome of stem cell divisions in the Drosophila male germ line. The mother centrosome remains anchored near the niche while the daughter centrosome migrates to the opposite side of the cell before spindle formation. PMID:17255513

  3. Asymmetric cell divisions in flowering plants - one mother, "two-many" daughters.

    PubMed

    Ranganath, R M

    2005-09-01

    Plant development shows a fascinating range of asymmetric cell divisions. Over the years, however, cellular differentiation has been interpreted mostly in terms of a mother cell dividing mitotically to produce two daughter cells of different fates. This popular view has masked the significance of an entirely different cell fate specification pathway, where the mother cell first becomes a coenocyte and then cellularizes to simultaneously produce more than two specialized daughter cells. The "one mother - two different daughters" pathways rely on spindle-assisted mechanisms, such as translocation of the nucleus/spindle to a specific cellular site and orientation of the spindle, which are coordinated with cell-specific allocation of cell fate determinants and cytokinesis. By contrast, during "coenocyte-cellularization" pathways, the spindle-assisted mechanisms are irrelevant since cell fate specification emerges only after the nuclear divisions are complete, and the number of specialized daughter cells produced depends on the developmental context. The key events, such as the formation of a coenocyte and migration of the nuclei to specific cellular locations, are coordinated with cellularization by unique types of cell wall formation. Both one mother - two different daughters and the coenocyte-cellularization pathways are used by higher plants in precise spatial and time windows during development. In both the pathways, epigenetic regulation of gene expression is crucial not only for cell fate specification but also for its maintenance through cell lineage. In this review, the focus is on the coenocyte-cellularization pathways in the context of our current understanding of the asymmetric cell divisions. Instances where cell differentiation does not involve an asymmetric division are also discussed to provide a comprehensive account of cell differentiation.

  4. Stem cells. Asymmetric apportioning of aged mitochondria between daughter cells is required for stemness.

    PubMed

    Katajisto, Pekka; Döhla, Julia; Chaffer, Christine L; Pentinmikko, Nalle; Marjanovic, Nemanja; Iqbal, Sharif; Zoncu, Roberto; Chen, Walter; Weinberg, Robert A; Sabatini, David M

    2015-04-17

    By dividing asymmetrically, stem cells can generate two daughter cells with distinct fates. However, evidence is limited in mammalian systems for the selective apportioning of subcellular contents between daughters. We followed the fates of old and young organelles during the division of human mammary stemlike cells and found that such cells apportion aged mitochondria asymmetrically between daughter cells. Daughter cells that received fewer old mitochondria maintained stem cell traits. Inhibition of mitochondrial fission disrupted both the age-dependent subcellular localization and segregation of mitochondria and caused loss of stem cell properties in the progeny cells. Hence, mechanisms exist for mammalian stemlike cells to asymmetrically sort aged and young mitochondria, and these are important for maintaining stemness properties. Copyright © 2015, American Association for the Advancement of Science.

  5. Fast Mechanically Driven Daughter Cell Separation Is Widespread in Actinobacteria.

    PubMed

    Zhou, Xiaoxue; Halladin, David K; Theriot, Julie A

    2016-08-30

    Dividing cells of the coccoid Gram-positive bacterium Staphylococcus aureus undergo extremely rapid (millisecond) daughter cell separation (DCS) driven by mechanical crack propagation, a strategy that is very distinct from the gradual, enzymatically driven cell wall remodeling process that has been well described in several rod-shaped model bacteria. To determine if other bacteria, especially those in the same phylum (Firmicutes) or with similar coccoid shapes as S. aureus, might use a similar mechanically driven strategy for DCS, we used high-resolution video microscopy to examine cytokinesis in a phylogenetically wide range of species with various cell shapes and sizes. We found that fast mechanically driven DCS is rather rare in the Firmicutes (low G+C Gram positives), observed only in Staphylococcus and its closest coccoid relatives in the Macrococcus genus, and we did not observe this division strategy among the Gram-negative Proteobacteria In contrast, several members of the high-G+C Gram-positive phylum Actinobacteria (Micrococcus luteus, Brachybacterium faecium, Corynebacterium glutamicum, and Mycobacterium smegmatis) with diverse shapes ranging from coccoid to rod all undergo fast mechanical DCS during cell division. Most intriguingly, similar fast mechanical DCS was also observed during the sporulation of the actinobacterium Streptomyces venezuelae Much of our knowledge on bacterial cytokinesis comes from studying rod-shaped model organisms such as Escherichia coli and Bacillus subtilis Less is known about variations in this process among different bacterial species. While cell division in many bacteria has been characterized to some extent genetically or biochemically, few species have been examined using video microscopy to uncover the kinetics of cytokinesis and daughter cell separation (DCS). In this work, we found that fast (millisecond) DCS is exhibited by species in two independent clades of Gram-positive bacteria and is particularly prevalent

  6. Parents' Marital Distress, Divorce, and Remarriage: Links with Daughters' Early Family Formation Transitions

    ERIC Educational Resources Information Center

    Amato, Paul R.; Kane, Jennifer B.

    2011-01-01

    The authors used data from the Add Health study to estimate the effects of parents' marital status and relationship distress on daughters' early family formation transitions. Outcomes included traditional transitions (marriage and marital births) and nontraditional transitions (cohabitation and nonmarital births). Relationship distress among…

  7. Parents' Marital Distress, Divorce, and Remarriage: Links with Daughters' Early Family Formation Transitions

    ERIC Educational Resources Information Center

    Amato, Paul R.; Kane, Jennifer B.

    2011-01-01

    The authors used data from the Add Health study to estimate the effects of parents' marital status and relationship distress on daughters' early family formation transitions. Outcomes included traditional transitions (marriage and marital births) and nontraditional transitions (cohabitation and nonmarital births). Relationship distress among…

  8. Fast Mechanically Driven Daughter Cell Separation Is Widespread in Actinobacteria

    PubMed Central

    Zhou, Xiaoxue; Halladin, David K.

    2016-01-01

    ABSTRACT Dividing cells of the coccoid Gram-positive bacterium Staphylococcus aureus undergo extremely rapid (millisecond) daughter cell separation (DCS) driven by mechanical crack propagation, a strategy that is very distinct from the gradual, enzymatically driven cell wall remodeling process that has been well described in several rod-shaped model bacteria. To determine if other bacteria, especially those in the same phylum (Firmicutes) or with similar coccoid shapes as S. aureus, might use a similar mechanically driven strategy for DCS, we used high-resolution video microscopy to examine cytokinesis in a phylogenetically wide range of species with various cell shapes and sizes. We found that fast mechanically driven DCS is rather rare in the Firmicutes (low G+C Gram positives), observed only in Staphylococcus and its closest coccoid relatives in the Macrococcus genus, and we did not observe this division strategy among the Gram-negative Proteobacteria. In contrast, several members of the high-G+C Gram-positive phylum Actinobacteria (Micrococcus luteus, Brachybacterium faecium, Corynebacterium glutamicum, and Mycobacterium smegmatis) with diverse shapes ranging from coccoid to rod all undergo fast mechanical DCS during cell division. Most intriguingly, similar fast mechanical DCS was also observed during the sporulation of the actinobacterium Streptomyces venezuelae. PMID:27578753

  9. Complete Budding and Asymmetric Division of Primitive Model Cells To Produce Daughter Vesicles with Different Interior and Membrane Compositions

    PubMed Central

    2011-01-01

    Asymmetric cell division is common in biology and plays critical roles in differentiation and development. Unicellular organisms are often used as model systems for understanding the origins and consequences of asymmetry during cell division. Although basic as compared to mammalian cells, these are already quite complex. We report complete budding and asymmetric fission of very simple nonliving model cells to produce daughter vesicles that are chemically distinct in both interior and membrane compositions. Our model cells are based on giant lipid vesicles (GVs, 10–30 μm) encapsulating a polyethylene glycol (PEG)/dextran aqueous two-phase system (ATPS) as a crowded and compartmentalized cytoplasm mimic. Ternary lipid compositions were used to provide coexisting micrometer-scale liquid disordered (Ld) and liquid ordered (Lo) domains in the membranes. ATPS-containing vesicles formed buds when sucrose was added externally to provide increased osmotic pressure, such that they became not only morphologically asymmetric but also asymmetric in both their interior and their membrane compositions. Further increases in osmolality drove formation of two chemically distinct daughter vesicles, which were in some cases connected by a lipid nanotube (complete budding), and in others were not (fission). In all cases, separation occurred at the aqueous–aqueous phase boundary, such that one daughter vesicle contained the PEG-rich aqueous phase and the other contained the dextran-rich aqueous phase. PEGylated lipids localized in the Lo domain resulted in this membrane domain preferentially coating the PEG-rich bud prior to division, and subsequently the PEG-rich daughter vesicle. Varying the mole ratio of lipids resulted in excess surface area of Lo or Ld membrane domains such that, upon division, this excess portion was inherited by one of the daughter vesicles. In some cases, a second “generation” of aqueous phase separation and budding could be induced in these daughter

  10. Daughter Cells and Erythroid Cells Budding from PGCCs and Their Clinicopathological Significances in Colorectal Cancer

    PubMed Central

    Zhang, Dan; Yang, Xiaoyun; Yang, Zhengduo; Fei, Fei; Li, Shuyuan; Qu, Jie; Zhang, Mingqing; Li, Yuwei; Zhang, Xipeng; Zhang, Shiwu

    2017-01-01

    Purpose: We previously reported that polyploid giant cancer cells (PGCCs) induced by cobalt chloride (CoCl2) exhibit cancer stem cell properties. Daughter cells generated by PGCCs possess epithelial mesenchymal transition (EMT) phenotype changes and EMT plays an important role in cancer development and progression. This study investigated the characteristics of PGCCs from LoVo and HCT116 induced by CoCl2 and the clinicopathological significances of PGCCs in colorectal cancer (CRC). Materials and Methods: Western blotting and immunocytochemical staining were used to compare the expression levels of EMT-related proteins between PGCCs with budding daughter cells and the control cells. In addition, tissue samples were collected from 159 patients with CRC for analysis of PGCCs, vasculogenic mimicry (VM), and single stromal PGCCs with budding, as well as immunohistochemical staining for cathepsin B, vimentin, and hemoglobin A. Results: Single PGCCs induced by CoCl2 formed spheroids in vitro. Poorly differentiated CRCs showed the highest numbers of PGCCs and VM, and expression of cathepsin B. There was greater expression of EMT-related proteins in PGCCs with budding daughter cells than in control cells. The expression of vimentin located in PGCC nuclei. Single stomal PGCCs with budding were detected in 27.45% of well differentiated, 50% of moderately differentiated, and 90.20% of poorly differentiated CRC samples. PGCCs can generate erythroid cells that express delta-hemoglobin to form VM. Erythroid cells generated by PGCCs were positive for hemoglobin A immunocytochemical staining. Conclusion: PGCCs from LoVo and HCT116 treated by CoCl2 exhibited cancer stem cell properties. The number of PGCCs and VM were associated with CRC differentiation and daughter cells budded from PGCCs may promote the lymph node metastasis via expression of EMT-related proteins. PGCCs and their newly generated erythroid cells form VM structures. PMID:28261349

  11. Bacterial division. Mechanical crack propagation drives millisecond daughter cell separation in Staphylococcus aureus.

    PubMed

    Zhou, Xiaoxue; Halladin, David K; Rojas, Enrique R; Koslover, Elena F; Lee, Timothy K; Huang, Kerwyn Casey; Theriot, Julie A

    2015-05-01

    When Staphylococcus aureus undergoes cytokinesis, it builds a septum, generating two hemispherical daughters whose cell walls are only connected via a narrow peripheral ring. We found that resolution of this ring occurred within milliseconds ("popping"), without detectable changes in cell volume. The likelihood of popping depended on cell-wall stress, and the separating cells split open asymmetrically, leaving the daughters connected by a hinge. An elastostatic model of the wall indicated high circumferential stress in the peripheral ring before popping. Last, we observed small perforations in the peripheral ring that are likely initial points of mechanical failure. Thus, the ultrafast daughter cell separation in S. aureus appears to be driven by accumulation of stress in the peripheral ring and exhibits hallmarks of mechanical crack propagation.

  12. Modeling partitioning of Min proteins between daughter cells after septation in Escherichia coli

    NASA Astrophysics Data System (ADS)

    Sengupta, Supratim; Rutenberg, Andrew

    2007-09-01

    Ongoing sub-cellular oscillation of Min proteins is required to block minicelling in Escherichia coli. Experimentally, Min oscillations are seen in newly divided cells and no minicells are produced. In model Min systems many daughter cells do not oscillate following septation because of unequal partitioning of Min proteins between the daughter cells. Using the 3D model of Huang et al, we investigate the septation process in detail to determine the cause of the asymmetric partitioning of Min proteins between daughter cells. We find that this partitioning problem arises at certain phases of the MinD and MinE oscillations with respect to septal closure and it persists independently of parameter variation. At most 85% of the daughter cells exhibit Min oscillation following septation. Enhanced MinD binding at the static polar and dynamic septal regions, consistent with cardiolipin domains, does not substantially increase this fraction of oscillating daughters. We believe that this problem will be shared among all existing Min models and discuss possible biological mechanisms that may minimize partitioning errors of Min proteins following septation.

  13. Proteomics analysis for asymmetric inheritance of preexisting proteins between mother and daughter cells in budding yeast.

    PubMed

    Okada, Mitsuhiro; Kusunoki, Shunta; Ishibashi, Yuko; Kito, Keiji

    2017-06-01

    In budding yeast, a mother cell can produce a finite number of daughter cells over its life. The accumulation of a variety of types of damaged components has an impact on the aging process. Asymmetrical inheritance during cell division causes these aberrant intracellular constituents to be retained in mother cells and prevents them from segregating to daughter cells. However, the understanding of asymmetrical inheritance of individual proteins that are damaged or old age, and their relevance to the aging process, has been limited. The aim of this study is to propose a proteomics strategy for asymmetrical inheritance of preexisting proteins between mother and daughter cells. During synchronous culture for one generation, newly synthesized proteins were labeled with stable isotope amino acids to discriminate preexisting proteins originally expressed in mother cells, followed by separation of mother and daughter cells using a conventional method based on biotin labeling. Isotope incorporation ratios for individual proteins were quantified using mass spectrometry. We successfully identified 21 proteins whose preexisting versions were asymmetrically inherited in mother cells, including plasma membrane transporter involved in the aging process and organelle-anchoring proteins related to the stress response to misfolded proteins. Thus, our approach would be useful for making catalog of asymmetrically inherited proteins. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

  14. Discontinuous Cyclone Movement of Mediterranean cyclones identified through formation analysis of daughter cyclones

    NASA Astrophysics Data System (ADS)

    Ziv, Baruch; Saaroni, Hadas; Harpaz, Tzvi

    2016-04-01

    A new algorithm developed performs an automated classification methodology for daughter cyclones (DCs) formation, with respect to the thermal field of the parent cyclones (PCs). The classification has been applied to winter Mediterranean Cyclones. The algorithm assigns a DC to one of seven types, according to the following considerations: Has the cyclone formed on a front? Is that a cold, a warm or a quasi-stationary front? Is this front part of the frontal system of the PC or of a non-parental system? If none of the above applies, has the cyclone formed within the warm sector? The measures used are the temperature gradient, temperature advection and temperature Laplacian, computed at the formation location of the DC and the temperature difference between the DC and the PC, each derived from the 850-hPa wind and temperature fields. Out of 4,303 DCs analyzed, 85% were identified to belong to one of the 7 predefined types, implying that 15% cannot be related to either baroclinic or thermal factors. More than half were formed at their PCs' frontal system, third on a non-parental frontal system and only 13% within the warm sector of the PC. Most of the cyclones, formed on the PC's cold front, were found at mountain lee locations, whereas cyclones formed on the warm front were generated mostly over the Aegean and the Adriatic Sea. The new methodology exposed a unique DC formation which is actually a Discontinuous Cyclone Movement (DCM), imposed by an encounter with geographical forcing. This formation was identified in 5.9% of the DC formations and is characterized by the following features: 1) parent-daughter distance (d) <1000 Km, 2) the area enclosed by the inner isobar surrounding both the PC and the DC should be less than 2d, 3) the PC should last no more than 18 hours after the DC has been first detected. DCM events found among DCs formed on warm fronts of PCs, to their east, are suggested as a mechanism which enables the PC to cross topographic barriers

  15. Prolonged prometaphase blocks daughter cell proliferation despite normal completion of mitosis.

    PubMed

    Uetake, Yumi; Sluder, Greenfield

    2010-09-28

    The mitotic checkpoint maintains genomic stability by blocking the metaphase-anaphase transition until all kinetochores attach to spindle microtubules [1, 2]. However, some defects are not detected by this checkpoint. With low concentrations of microtubule-targeting agents, the checkpoint eventually becomes satisfied, though the spindles may be short and/or multipolar [3, 4] and the fidelity of chromosome distribution and cleavage completion are compromised. In real life, environmental toxins, radiation, or chemotherapeutic agents may lead to completed but inaccurate mitoses. It has been assumed that once the checkpoint is satisfied and cells divide, the daughter cells would proliferate regardless of prometaphase duration. However, when continuously exposed to microtubule inhibitors, untransformed cells eventually slip out of mitosis after 12-48 hr and arrest in G1 [5-8] (see also [9]). Interestingly, transient but prolonged treatments with nocodazole allow completion of mitosis, but the daughter cells arrest in interphase [10, 11] (see also [9, 12]). Here we characterize the relationship between prometaphase duration and the proliferative capacity of daughter cells. Our results reveal the existence of a mechanism that senses prometaphase duration; if prometaphase lasts >1.5 hr, this mechanism triggers a durable p38- and p53-dependent G1 arrest of the daughter cells despite normal division of their mothers. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. The Arabidopsis Receptor Kinase ZAR1 Is Required for Zygote Asymmetric Division and Its Daughter Cell Fate

    PubMed Central

    Jia, Peng-Fei; Tang, Jun; Li, Hong-Ju; Liu, Jie; Yang, Wei-Cai

    2016-01-01

    Asymmetric division of zygote is critical for pattern formation during early embryogenesis in plants and animals. It requires integration of the intrinsic and extrinsic cues prior to and/or after fertilization. How these cues are translated into developmental signals is poorly understood. Here through genetic screen for mutations affecting early embryogenesis, we identified an Arabidopsis mutant, zygotic arrest 1 (zar1), in which zygote asymmetric division and the cell fate of its daughter cells were impaired. ZAR1 encodes a member of the RLK/Pelle kinase family. We demonstrated that ZAR1 physically interacts with Calmodulin and the heterotrimeric G protein Gβ, and ZAR1 kinase is activated by their binding as well. ZAR1 is specifically expressed micropylarly in the embryo sac at eight-nucleate stage and then in central cell, egg cell and synergids in the mature embryo sac. After fertilization, ZAR1 is accumulated in zygote and endosperm. The disruption of ZAR1 and AGB1 results in short basal cell and an apical cell with basal cell fate. These data suggest that ZAR1 functions as a membrane integrator for extrinsic cues, Ca2+ signal and G protein signaling to regulate the division of zygote and the cell fate of its daughter cells in Arabidopsis. PMID:27014878

  17. The Arabidopsis Receptor Kinase ZAR1 Is Required for Zygote Asymmetric Division and Its Daughter Cell Fate.

    PubMed

    Yu, Tian-Ying; Shi, Dong-Qiao; Jia, Peng-Fei; Tang, Jun; Li, Hong-Ju; Liu, Jie; Yang, Wei-Cai

    2016-03-01

    Asymmetric division of zygote is critical for pattern formation during early embryogenesis in plants and animals. It requires integration of the intrinsic and extrinsic cues prior to and/or after fertilization. How these cues are translated into developmental signals is poorly understood. Here through genetic screen for mutations affecting early embryogenesis, we identified an Arabidopsis mutant, zygotic arrest 1 (zar1), in which zygote asymmetric division and the cell fate of its daughter cells were impaired. ZAR1 encodes a member of the RLK/Pelle kinase family. We demonstrated that ZAR1 physically interacts with Calmodulin and the heterotrimeric G protein Gβ, and ZAR1 kinase is activated by their binding as well. ZAR1 is specifically expressed micropylarly in the embryo sac at eight-nucleate stage and then in central cell, egg cell and synergids in the mature embryo sac. After fertilization, ZAR1 is accumulated in zygote and endosperm. The disruption of ZAR1 and AGB1 results in short basal cell and an apical cell with basal cell fate. These data suggest that ZAR1 functions as a membrane integrator for extrinsic cues, Ca2+ signal and G protein signaling to regulate the division of zygote and the cell fate of its daughter cells in Arabidopsis.

  18. The ER Stress Surveillance (ERSU) pathway regulates daughter cell ER protein aggregate inheritance.

    PubMed

    Piña, Francisco J; Niwa, Maho

    2015-09-01

    Stress induced by cytoplasmic protein aggregates can have deleterious consequences for the cell, contributing to neurodegeneration and other diseases. Protein aggregates are also formed within the endoplasmic reticulum (ER), although the fate of ER protein aggregates, specifically during cell division, is not well understood. By simultaneous visualization of both the ER itself and ER protein aggregates, we found that ER protein aggregates that induce ER stress are retained in the mother cell by activation of the ER Stress Surveillance (ERSU) pathway, which prevents inheritance of stressed ER. In contrast, under conditions of normal ER inheritance, ER protein aggregates can enter the daughter cell. Thus, whereas cytoplasmic protein aggregates are retained in the mother cell to protect the functional capacity of daughter cells, the fate of ER protein aggregates is determined by whether or not they activate the ERSU pathway to impede transmission of the cortical ER during the cell cycle.

  19. Late type of daughter cell wall synthesis in one of the Chlorellaceae, Parachlorella kessleri (Chlorophyta, Trebouxiophyceae).

    PubMed

    Yamamoto, Maki; Kurihara, Ippei; Kawano, Shigeyuki

    2005-08-01

    Autosporulation is a common mode of propagation for unicellular algae. Autospore-forming species of Chlorellaceae, Chlorella vulgaris Beijerinck, C. sorokiniana Shihira et Krauss, C. lobophora Andreyeva, and Parachlorella kessleri (Fott et Nováková) Krienitz et al. have glucosamine as the main constituent of their rigid cell wall. Recent phylogenetic analyses have showed that the Chlorellaceae divided into two sister groups: the Chlorella-clade and the Parachlorella-clade. We compared the cell wall structure and synthesis of the daughter cell wall in the four species by electron microscopy using rapid freezing and freeze substitution methods. The cell wall of C. vulgaris, C. sorokiniana, and C. lobophora consisted of an electron-dense thin layer with an average thickness of 17-20, 22, and 19 nm, respectively. In these three species, daughter cell wall synthesis occurred on the outer surface of the plasma membrane in the early cell-growth phase. The cell wall of P. kessleri, however, was electron-transparent and 54-59 nm in thickness. Ruthenium red staining of P. kessleri indicated that ruthenium-red-specific polysaccharides accumulated over the outer surface of the plasma membrane. Immunoelectron microscopic observation with an anti-beta-1, 3-glucan antibody and staining with wheat germ agglutinin (WGA) indicated that the cell wall contained beta-1, 3-glucan and WGA specific N-acetyl-beta-D-glucosamine. In P. kessleri, daughter cell wall synthesis began after successive protoplast division. The daughter cell wall synthesis during autosporulation in the four species of Chlorellaceae can be classified into two types-the early and the late types.

  20. TopBP1 is required at mitosis to reduce transmission of DNA damage to G1 daughter cells

    PubMed Central

    Pedersen, Rune Troelsgaard; Kruse, Thomas; Nilsson, Jakob

    2015-01-01

    Genome integrity is critically dependent on timely DNA replication and accurate chromosome segregation. Replication stress delays replication into G2/M, which in turn impairs proper chromosome segregation and inflicts DNA damage on the daughter cells. Here we show that TopBP1 forms foci upon mitotic entry. In early mitosis, TopBP1 marks sites of and promotes unscheduled DNA synthesis. Moreover, TopBP1 is required for focus formation of the structure-selective nuclease and scaffold protein SLX4 in mitosis. Persistent TopBP1 foci transition into 53BP1 nuclear bodies (NBs) in G1 and precise temporal depletion of TopBP1 just before mitotic entry induced formation of 53BP1 NBs in the next cell cycle, showing that TopBP1 acts to reduce transmission of DNA damage to G1 daughter cells. Based on these results, we propose that TopBP1 maintains genome integrity in mitosis by controlling chromatin recruitment of SLX4 and by facilitating unscheduled DNA synthesis. PMID:26283799

  1. [Response of HeLa cells to mitomycine C. III. The analysis of nucleoli of mother and daughter cells].

    PubMed

    Petrov, Iu P; Neguliaev, Iu A; Tsupkina, N V

    2014-01-01

    The comparative analysis of the number of nucleoli in cells of the established HeLa-M line was carried out before and after exposure to mitomycin C in a concentration of 10 μg/ml for 2 h. Using time-lapse microscopy, nucleoli in mother and their respective daughter cells were computed. It has been shown that the average number of nucleoli per cell is generally higher in daughter cells than in mother cells, and a standard deviation, on the contrary, decreases. An average number of nucleoli in daughter cells, whose mother cells had been treated with mitomycin C, was higher than in corresponding cells of control group. The separate analysis has been performed for the cells having from 1 to 4 nucleoli. Nonrandom complete coincidence of the number of nucleoli in mather and daughter cells has been typicaly shown for about 1/7 of the total cell population. Mitomycin C reduces this value of about 1.5 times.

  2. Daughter cell separation is controlled by cytokinetic ring-activated cell wall hydrolysis

    PubMed Central

    Uehara, Tsuyoshi; Parzych, Katherine R; Dinh, Thuy; Bernhardt, Thomas G

    2010-01-01

    During bacterial cytokinesis, hydrolytic enzymes are used to split wall material shared by adjacent daughter cells to promote their separation. Precise control over these enzymes is critical to prevent breaches in wall integrity that can cause cell lysis. How these potentially lethal hydrolases are regulated has remained unknown. Here, we investigate the regulation of cell wall turnover at the Escherichia coli division site. We show that two components of the division machinery with LytM domains (EnvC and NlpD) are direct regulators of the cell wall hydrolases (amidases) responsible for cell separation (AmiA, AmiB and AmiC). Using in vitro cell wall cleavage assays, we show that EnvC activates AmiA and AmiB, whereas NlpD activates AmiC. Consistent with these findings, we show that an unregulated EnvC mutant requires functional AmiA or AmiB but not AmiC to induce cell lysis, and that the loss of NlpD phenocopies an AmiC− defect. Overall, our results suggest that cellular amidase activity is regulated spatially and temporally by coupling their activation to the assembly of the cytokinetic ring. PMID:20300061

  3. Daughter cell separation is controlled by cytokinetic ring-activated cell wall hydrolysis.

    PubMed

    Uehara, Tsuyoshi; Parzych, Katherine R; Dinh, Thuy; Bernhardt, Thomas G

    2010-04-21

    During bacterial cytokinesis, hydrolytic enzymes are used to split wall material shared by adjacent daughter cells to promote their separation. Precise control over these enzymes is critical to prevent breaches in wall integrity that can cause cell lysis. How these potentially lethal hydrolases are regulated has remained unknown. Here, we investigate the regulation of cell wall turnover at the Escherichia coli division site. We show that two components of the division machinery with LytM domains (EnvC and NlpD) are direct regulators of the cell wall hydrolases (amidases) responsible for cell separation (AmiA, AmiB and AmiC). Using in vitro cell wall cleavage assays, we show that EnvC activates AmiA and AmiB, whereas NlpD activates AmiC. Consistent with these findings, we show that an unregulated EnvC mutant requires functional AmiA or AmiB but not AmiC to induce cell lysis, and that the loss of NlpD phenocopies an AmiC(-) defect. Overall, our results suggest that cellular amidase activity is regulated spatially and temporally by coupling their activation to the assembly of the cytokinetic ring.

  4. The ER Stress Surveillance (ERSU) pathway regulates daughter cell ER protein aggregate inheritance

    PubMed Central

    Piña, Francisco J; Niwa, Maho

    2015-01-01

    Stress induced by cytoplasmic protein aggregates can have deleterious consequences for the cell, contributing to neurodegeneration and other diseases. Protein aggregates are also formed within the endoplasmic reticulum (ER), although the fate of ER protein aggregates, specifically during cell division, is not well understood. By simultaneous visualization of both the ER itself and ER protein aggregates, we found that ER protein aggregates that induce ER stress are retained in the mother cell by activation of the ER Stress Surveillance (ERSU) pathway, which prevents inheritance of stressed ER. In contrast, under conditions of normal ER inheritance, ER protein aggregates can enter the daughter cell. Thus, whereas cytoplasmic protein aggregates are retained in the mother cell to protect the functional capacity of daughter cells, the fate of ER protein aggregates is determined by whether or not they activate the ERSU pathway to impede transmission of the cortical ER during the cell cycle. DOI: http://dx.doi.org/10.7554/eLife.06970.001 PMID:26327697

  5. Purification of G1 daughter cells from different Saccharomycetes species through an optimized centrifugal elutriation procedure.

    PubMed

    Marbouty, Martial; Ermont, Caroline; Dujon, Bernard; Richard, Guy-Franck; Koszul, Romain

    2014-05-01

    Centrifugal elutriation discriminates cells according to their sedimentation coefficients, generating homogeneous samples well suited for genomic comparative approaches. It can, for instance, isolate G1 daughter cells from a Saccharomyces cerevisiae unsynchronized population, alleviating ageing and cell-cycle biases when conducting genome-wide/single-cell studies. The present report describes a straightforward and robust procedure to determine whether a cell population of virtually any yeast species can be efficiently elutriated, while offering solutions to optimize success. This approach was used to characterize elutriation parameters and S-phase progression of four yeast species (S. cerevisiae, Candida glabrata, Lachancea kluyveri and Pichia sorbitophila) and could theoretically be applied to any culture of single, individual cells. Copyright © 2014 John Wiley & Sons, Ltd.

  6. Polarization of Diploid Daughter Cells Directed by Spatial Cues and GTP Hydrolysis of Cdc42 in Budding Yeast

    PubMed Central

    Narayan, Monisha; Chou, Ching-Shan; Park, Hay-Oak

    2013-01-01

    Cell polarization occurs along a single axis that is generally determined by a spatial cue. Cells of the budding yeast exhibit a characteristic pattern of budding, which depends on cell-type-specific cortical markers, reflecting a genetic programming for the site of cell polarization. The Cdc42 GTPase plays a key role in cell polarization in various cell types. Although previous studies in budding yeast suggested positive feedback loops whereby Cdc42 becomes polarized, these mechanisms do not include spatial cues, neglecting the normal patterns of budding. Here we combine live-cell imaging and mathematical modeling to understand how diploid daughter cells establish polarity preferentially at the pole distal to the previous division site. Live-cell imaging shows that daughter cells of diploids exhibit dynamic polarization of Cdc42-GTP, which localizes to the bud tip until the M phase, to the division site at cytokinesis, and then to the distal pole in the next G1 phase. The strong bias toward distal budding of daughter cells requires the distal-pole tag Bud8 and Rga1, a GTPase activating protein for Cdc42, which inhibits budding at the cytokinesis site. Unexpectedly, we also find that over 50% of daughter cells lacking Rga1 exhibit persistent Cdc42-GTP polarization at the bud tip and the distal pole, revealing an additional role of Rga1 in spatiotemporal regulation of Cdc42 and thus in the pattern of polarized growth. Mathematical modeling indeed reveals robust Cdc42-GTP clustering at the distal pole in diploid daughter cells despite random perturbation of the landmark cues. Moreover, modeling predicts different dynamics of Cdc42-GTP polarization when the landmark level and the initial level of Cdc42-GTP at the division site are perturbed by noise added in the model. PMID:23437206

  7. Structure and functional regulation of RipA, a mycobacterial enzyme essential for daughter cell separation.

    PubMed

    Ruggiero, Alessia; Marasco, Daniela; Squeglia, Flavia; Soldini, Silvia; Pedone, Emilia; Pedone, Carlo; Berisio, Rita

    2010-09-08

    Cell separation depends on cell-wall hydrolases that cleave the peptidoglycan layer connecting daughter cells. In Mycobacterium tuberculosis, this process is governed by the predicted endopeptidase RipA. In the absence of this enzyme, the bacterium is unable to divide and exhibits an abnormal phenotype. We here report the crystal structure of a relevant portion of RipA, containing its catalytic-domain and an extra-domain of hitherto unknown function. The structure clearly demonstrates that RipA is produced as a zymogen, which needs to be activated to achieve cell-division. Bacterial cell-wall degradation assays and proteolysis experiments strongly suggest that activation occurs via proteolytic processing of a fully solvent exposed loop identified in the crystal structure. Indeed, proteolytic cleavage at this loop produces an activated form, consisting of the sole catalytic domain. Our work provides the first evidence of self-inhibition in cell-disconnecting enzymes and opens a field for the design of novel antitubercular therapeutics. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Chromatin remodeling modulates radiosensitivity of the daughter cells derived from cell population exposed to low- and high-LET irradiation

    PubMed Central

    Chen, Xiaoyan; Zhu, Lin; Zhang, Hang; Wang, Chen; Shao, Chunlin

    2017-01-01

    Radiation effects are dependent of linear energy transfer (LET), but it is still obscure whether the daughter cells (DCs) derived from irradiated population are radioresistance and much less the underlying mechanism. With the measurements of survival, proliferation and γH2AX foci, this study shows that the DCs from γ-ray irradiated cells (DCs-γ) became more radioresistant than its parent control without irradiation, but the radiosensitivity of DCs from α-particle irradiated cells (DCs-α) was not altered. After irradiation with equivalent doses of γ-rays and α-particles, the foci number of histone H3 lysine 9 dimethylation (H3K9me3) and the activity of histone deacetylase (HDAC) in DCs-γ was extensively higher than these in DCs-α and its parent control, indicating that a higher level of heterochromatin was formed in DCs-γ but not in DCs-α. Treatment of cells with SAHA (an inhibitor of HDAC) decreased the level of heterochromatin domains by inhibiting the expressions of H3K9m3 and HP-1a proteins and triggering the expression of acetylated core histone H3 (Ac-H3). When cells were treated with SAHA, the radioresistance phenotype of DCs-γ was eliminated so that the radiosensitivities of DCs-γ, DCs-α and their parent cells approached to same levels. Our current results reveal that γ-rays but not α-particles could induce chromatin remodeling and heterochromatinization which results in the occurrence of radioresistance of DCs, indicating that the combination treatment of irradiation and HDAC inhibitor could serve as a potential cancer therapy strategy, especially for the fraction radiotherapy of low-LET irradiation. PMID:28881774

  9. Control of Neural Daughter Cell Proliferation by Multi-level Notch/Su(H)/E(spl)-HLH Signaling

    PubMed Central

    Bivik, Caroline; MacDonald, Ryan B.; Gunnar, Erika; Mazouni, Khalil; Schweisguth, Francois; Thor, Stefan

    2016-01-01

    The Notch pathway controls proliferation during development and in adulthood, and is frequently affected in many disorders. However, the genetic sensitivity and multi-layered transcriptional properties of the Notch pathway has made its molecular decoding challenging. Here, we address the complexity of Notch signaling with respect to proliferation, using the developing Drosophila CNS as model. We find that a Notch/Su(H)/E(spl)-HLH cascade specifically controls daughter, but not progenitor proliferation. Additionally, we find that different E(spl)-HLH genes are required in different neuroblast lineages. The Notch/Su(H)/E(spl)-HLH cascade alters daughter proliferation by regulating four key cell cycle factors: Cyclin E, String/Cdc25, E2f and Dacapo (mammalian p21CIP1/p27KIP1/p57Kip2). ChIP and DamID analysis of Su(H) and E(spl)-HLH indicates direct transcriptional regulation of the cell cycle genes, and of the Notch pathway itself. These results point to a multi-level signaling model and may help shed light on the dichotomous proliferative role of Notch signaling in many other systems. PMID:27070787

  10. Comparative transcriptional profiling analysis of the two daughter cells from tobacco zygote reveals the transcriptome differences in the apical and basal cells

    PubMed Central

    2010-01-01

    Background In angiosperm, after the first asymmetric zygotic cell division, the apical and basal daughter cells follow distinct development pathways. Global transcriptome analysis of these two cells is essential in understanding their developmental differences. However, because of the difficulty to isolate the in vivo apical and basal cells of two-celled proembryo from ovule and ovary in higher plants, the transcriptome analysis of them hasn't been reported. Results In this study, we developed a procedure for isolating the in vivo apical and basal cells of the two-celled proembryo from tobacco (Nicotiana tabacum), and then performed a comparative transcriptome analysis of the two cells by suppression subtractive hybridization (SSH) combined with macroarray screening. After sequencing, we identified 797 differentially expressed ESTs corresponding to 299 unigenes. Library sequence analysis successfully identified tobacco homologies of genes involved in embryogenesis and seed development. By quantitative real-time PCR, we validated the differential expression of 40 genes, with 6 transcripts of them specifically expressed in the apical or basal cell. Expression analysis also revealed some transcripts displayed cell specific activation in one of the daughter cells after zygote division. These differential expressions were further validated by in situ hybridization (ISH). Tissue expression pattern analysis also revealed some potential roles of these candidate genes in development. Conclusions The results show that some differential or specific transcripts in the apical and basal cells of two-celled proembryo were successfully isolated, and the identification of these transcripts reveals that these two daughter cells possess distinct transcriptional profiles after zygote division. Further functional work on these differentially or specifically expressed genes will promote the elucidation of molecular mechanism controlling early embryogenesis. PMID:20699003

  11. Comparative transcriptional profiling analysis of the two daughter cells from tobacco zygote reveals the transcriptome differences in the apical and basal cells.

    PubMed

    Hu, Tian-Xiang; Yu, Miao; Zhao, Jie

    2010-08-11

    In angiosperm, after the first asymmetric zygotic cell division, the apical and basal daughter cells follow distinct development pathways. Global transcriptome analysis of these two cells is essential in understanding their developmental differences. However, because of the difficulty to isolate the in vivo apical and basal cells of two-celled proembryo from ovule and ovary in higher plants, the transcriptome analysis of them hasn't been reported. In this study, we developed a procedure for isolating the in vivo apical and basal cells of the two-celled proembryo from tobacco (Nicotiana tabacum), and then performed a comparative transcriptome analysis of the two cells by suppression subtractive hybridization (SSH) combined with macroarray screening. After sequencing, we identified 797 differentially expressed ESTs corresponding to 299 unigenes. Library sequence analysis successfully identified tobacco homologies of genes involved in embryogenesis and seed development. By quantitative real-time PCR, we validated the differential expression of 40 genes, with 6 transcripts of them specifically expressed in the apical or basal cell. Expression analysis also revealed some transcripts displayed cell specific activation in one of the daughter cells after zygote division. These differential expressions were further validated by in situ hybridization (ISH). Tissue expression pattern analysis also revealed some potential roles of these candidate genes in development. The results show that some differential or specific transcripts in the apical and basal cells of two-celled proembryo were successfully isolated, and the identification of these transcripts reveals that these two daughter cells possess distinct transcriptional profiles after zygote division. Further functional work on these differentially or specifically expressed genes will promote the elucidation of molecular mechanism controlling early embryogenesis.

  12. Timing of ribosome synthesis during ascosporogenesis of yeast cells: evidence for early function of haploid daughter genomes.

    PubMed Central

    Emanuel, J R; Magee, P T

    1981-01-01

    During meiosis and sporulation in Saccharomyces cerevisiae, the recessive genetic marker for cycloheximide resistance, believed to be due to an altered ribosomal protein (C. S. McLaughlin, p. 815-827, in M. Nomura et al., ed., Ribosomes, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y.), is expressed as early as meiosis II. Ribosomal ribonucleic acid synthesis peaks near the time that cycloheximide resistance begins to appear. Less than 25% of the 17S and 25S ribonucleic acid of the vegetative cells persists in spores, but pulse-labeling studies indicate that greater than 90% of the stable ribonucleic acid made after 6 h survives in spores. These results indicate that the haploid daughter genomes begin to function near the time of meiosis II. PMID:7009580

  13. Systematic analysis of asymmetric partitioning of yeast proteome between mother and daughter cells reveals "aging factors" and mechanism of lifespan asymmetry.

    PubMed

    Yang, Jing; McCormick, Mark A; Zheng, Jiashun; Xie, Zhengwei; Tsuchiya, Mitsuhiro; Tsuchiyama, Scott; El-Samad, Hana; Ouyang, Qi; Kaeberlein, Matt; Kennedy, Brian K; Li, Hao

    2015-09-22

    Budding yeast divides asymmetrically, giving rise to a mother cell that progressively ages and a daughter cell with full lifespan. It is generally assumed that mother cells retain damaged, lifespan limiting materials ("aging factors") through asymmetric division. However, the identity of these aging factors and the mechanisms through which they limit lifespan remain poorly understood. Using a flow cytometry-based, high-throughput approach, we quantified the asymmetric partitioning of the yeast proteome between mother and daughter cells during cell division, discovering 74 mother-enriched and 60 daughter-enriched proteins. While daughter-enriched proteins are biased toward those needed for bud construction and genome maintenance, mother-enriched proteins are biased towards those localized in the plasma membrane and vacuole. Deletion of 23 of the 74 mother-enriched proteins leads to lifespan extension, a fraction that is about six times that of the genes picked randomly from the genome. Among these lifespan-extending genes, three are involved in endosomal sorting/endosome to vacuole transport, and three are nitrogen source transporters. Tracking the dynamic expression of specific mother-enriched proteins revealed that their concentration steadily increases in the mother cells as they age, but is kept relatively low in the daughter cells via asymmetric distribution. Our results suggest that some mother-enriched proteins may increase to a concentration that becomes deleterious and lifespan-limiting in aged cells, possibly by upsetting homeostasis or leading to aberrant signaling. Our study provides a comprehensive resource for analyzing asymmetric cell division and aging in yeast, which should also be valuable for understanding similar phenomena in other organisms.

  14. Systematic analysis of asymmetric partitioning of yeast proteome between mother and daughter cells reveals “aging factors” and mechanism of lifespan asymmetry

    PubMed Central

    Yang, Jing; McCormick, Mark A.; Zheng, Jiashun; Xie, Zhengwei; Tsuchiya, Mitsuhiro; Tsuchiyama, Scott; El-Samad, Hana; Ouyang, Qi; Kaeberlein, Matt; Kennedy, Brian K.; Li, Hao

    2015-01-01

    Budding yeast divides asymmetrically, giving rise to a mother cell that progressively ages and a daughter cell with full lifespan. It is generally assumed that mother cells retain damaged, lifespan limiting materials (“aging factors”) through asymmetric division. However, the identity of these aging factors and the mechanisms through which they limit lifespan remain poorly understood. Using a flow cytometry-based, high-throughput approach, we quantified the asymmetric partitioning of the yeast proteome between mother and daughter cells during cell division, discovering 74 mother-enriched and 60 daughter-enriched proteins. While daughter-enriched proteins are biased toward those needed for bud construction and genome maintenance, mother-enriched proteins are biased towards those localized in the plasma membrane and vacuole. Deletion of 23 of the 74 mother-enriched proteins leads to lifespan extension, a fraction that is about six times that of the genes picked randomly from the genome. Among these lifespan-extending genes, three are involved in endosomal sorting/endosome to vacuole transport, and three are nitrogen source transporters. Tracking the dynamic expression of specific mother-enriched proteins revealed that their concentration steadily increases in the mother cells as they age, but is kept relatively low in the daughter cells via asymmetric distribution. Our results suggest that some mother-enriched proteins may increase to a concentration that becomes deleterious and lifespan-limiting in aged cells, possibly by upsetting homeostasis or leading to aberrant signaling. Our study provides a comprehensive resource for analyzing asymmetric cell division and aging in yeast, which should also be valuable for understanding similar phenomena in other organisms. PMID:26351681

  15. Formative cell divisions: principal determinants of plant morphogenesis.

    PubMed

    Smolarkiewicz, Michalina; Dhonukshe, Pankaj

    2013-03-01

    Formative cell divisions utilizing precise rotations of cell division planes generate and spatially place asymmetric daughters to produce different cell layers. Therefore, by shaping tissues and organs, formative cell divisions dictate multicellular morphogenesis. In animal formative cell divisions, the orientation of the mitotic spindle and cell division planes relies on intrinsic and extrinsic cortical polarity cues. Plants lack known key players from animals, and cell division planes are determined prior to the mitotic spindle stage. Therefore, it appears that plants have evolved specialized mechanisms to execute formative cell divisions. Despite their profound influence on plant architecture, molecular players and cellular mechanisms regulating formative divisions in plants are not well understood. This is because formative cell divisions in plants have been difficult to track owing to their submerged positions and imprecise timings of occurrence. However, by identifying a spatiotemporally inducible cell division plane switch system applicable for advanced microscopy techniques, recent studies have begun to uncover molecular modules and mechanisms for formative cell divisions. The identified molecular modules comprise developmentally triggered transcriptional cascades feeding onto microtubule regulators that now allow dissection of the hierarchy of the events at better spatiotemporal resolutions. Here, we survey the current advances in understanding of formative cell divisions in plants in the context of embryogenesis, stem cell functionality and post-embryonic organ formation.

  16. Impact of genetic merit for milk somatic cell score of sires and maternal grandsires on herd life of their daughters.

    PubMed

    Miller, R H; Norman, H D; Wright, J R; Cole, J B

    2009-05-01

    A retrospective study of the impact of the estimated breeding values of sires and maternal grandsires for somatic cell score (SCS) on productive life (PL) of Holsteins and Jerseys was conducted. Data included records from 2,626,425 Holstein and 142,725 Jersey cows. The sires and maternal grandsires of cows were required to have been available through artificial insemination and to have predicted transmitting ability (PTA) SCS evaluations based on 35 or more daughters. A weighted function (WPTA) of sire and maternal grandsire PTA for SCS was used: (sire PTA + 0.5 maternal grandsire PTA)/1.5. The 3 dependent variables were PL, frequency of cows culled for mastitis, and first-lactation SCS. The model included effects of herd, birth year, and WPTA (WPTA was categorized into groups: <2.70, 2.70 to 2.79, ..., 3.20 to 3.29, > or =3.30). For analysis of first-lactation SCS, calving year and calving month were substituted for birth year. Differences among WPTA groups were highly significant: as WPTA increased, PL decreased, whereas percentage culled for mastitis and first-lactation SCS increased. The range in PL from lowest to highest WPTA was 5.07 mo for Holsteins and 4.73 mo for Jerseys. Corresponding differences for percentage culled for mastitis were 7.0 and 5.6% and for SCS were 0.95 and 1.04 (for Holsteins and Jerseys, respectively). Although phenotypic studies suggest that cows with extremely low SCS were less resistant to mastitis, our results showed consistent improvements in PL, percentage culled for mastitis, and SCS of daughters when bulls were chosen for low PTA SCS.

  17. Raising Strong Daughters.

    ERIC Educational Resources Information Center

    Gadeberg, Jeanette

    In response to an alarming drop in girls' self-esteem in early adolescence, this parents' guide provides suggestions for raising daughters to become confident, healthy, and independent. Chapter 1, "Yesterday's Daughters," examines how cultural messages inhibit girls' development. Chapter 2, "Raising an Opinionated Daughter,"…

  18. Raising Strong Daughters.

    ERIC Educational Resources Information Center

    Gadeberg, Jeanette

    In response to an alarming drop in girls' self-esteem in early adolescence, this parents' guide provides suggestions for raising daughters to become confident, healthy, and independent. Chapter 1, "Yesterday's Daughters," examines how cultural messages inhibit girls' development. Chapter 2, "Raising an Opinionated Daughter,"…

  19. Persistent competition among stem cells and their daughters in the Drosophila ovary germline niche.

    PubMed

    Rhiner, Christa; Díaz, Begoña; Portela, Marta; Poyatos, Juan F; Fernández-Ruiz, Irene; López-Gay, Jesús M; Gerlitz, Offer; Moreno, Eduardo

    2009-03-01

    Cell competition is a short-range cell-cell interaction leading to the proliferation of winner cells at the expense of losers, although either cell type shows normal growth in homotypic environments. Drosophila Myc (dMyc; Dm-FlyBase) is a potent inducer of cell competition in wing epithelia, but its role in the ovary germline stem cell niche is unknown. Here, we show that germline stem cells (GSCs) with relative lower levels of dMyc are replaced by GSCs with higher levels of dMyc. By contrast, dMyc-overexpressing GSCs outcompete wild-type stem cells without affecting total stem cell numbers. We also provide evidence for a naturally occurring cell competition border formed by high dMyc-expressing stem cells and low dMyc-expressing progeny, which may facilitate the concentration of the niche-provided self-renewal factor BMP/Dpp in metabolically active high dMyc stem cells. Genetic manipulations that impose uniform dMyc levels across the germline produce an extended Dpp signaling domain and cause uncoordinated differentiation events. We propose that dMyc-induced competition plays a dual role in regulating optimal stem cell pools and sharp differentiation boundaries, but is potentially harmful in the case of emerging dmyc duplications that facilitate niche occupancy by pre-cancerous stem cells. Moreover, competitive interactions among stem cells may be relevant for the successful application of stem cell therapies in humans.

  20. Formation of a cylindrical bridge in cell division

    NASA Astrophysics Data System (ADS)

    Citron, Daniel; Schmidt, Laura E.; Reichl, Elizabeth; Ren, Yixin; Robinson, Douglas; Zhang, Wendy W.

    2007-11-01

    In nature, the shape transition associated with the division of a mother cell into two daughter cells proceeds via a variety of routes. In the cylinder-thinning route, which has been observed in Dictyostelium and most animal cells, the mother cell first forms a broad bridge-like region, also known as a furrow, between two daughter cells. The furrow then rapidly evolves into a cylindrical bridge, which thins and eventually severs the mother cell into two. The fundamental mechanism underlying this division route is not understood. Recent experiments on Dictyostelium found that, while the cylinder-thinning route persists even when key actin cross-linking proteins are missing, it is disrupted by the removal of force-generating myosin-II proteins. Other measurements revealed that mutant cells lacking myosin-II have a much more uniform tension over the cell surface than wild-type cells. This suggests that tension variation may be important. Here we use a fluid model, previously shown to reproduce the thinning dynamics [Zhang & Robinson, PNAS 102, 7186 (2005)], to test this idea. Consistent with the experiments, the model shows that the cylinder formation process occurs regardless of the exact viscoelastic properties of the cell. In contrast to the experiments, a tension variation in the model hinders, rather then expedites, the cylinder formation.

  1. Microdosimetry of astatine-211 single-cell irradiation: role of daughter polonium-211 diffusion.

    PubMed

    Palm, Stig; Humm, John L; Rundqvist, Robert; Jacobsson, Lars

    2004-02-01

    A microdosimetric analysis of previously published data on 211At-albumin, free 211At, and 211At-C215 irradiation of Colo-205 cells in a slowly rotating single-cell suspension is presented. A custom-built computer program based on the Monte Carlo method was used to simulate the irradiation and the energy deposition in individual cell nuclei. Separate simulations were made for the assumption that the 211Po atom stays in the position where it is created, and that it diffuses away. The mean event number at which 37% of all cells survived, n37, and the frequency mean specific energy per event, zF, were estimated. The Poisson distribution of events and simulated single and multievent distributions of specific energy were used to find the single-cell specific energy at which the probability of survival is reduced to 37%, z37. The calculated single-cell radiosensitivity values show that 211Po atoms, created on a cell surface by the decay of 211At atoms, will diffuse from the cell during its life-span. The increasing distance to the cell nucleus will drastically decrease the probability of the emitted alpha particle to hit the nucleus. This will result in fewer alpha-particle events in the cell nucleus. For dispersed cells, the diffusion of 211Po atoms will reduce the total dose from cell-bound 211At by a factor of 2.

  2. Unreplicated DNA remaining from unperturbed S phases passes through mitosis for resolution in daughter cells.

    PubMed

    Moreno, Alberto; Carrington, Jamie T; Albergante, Luca; Al Mamun, Mohammed; Haagensen, Emma J; Komseli, Eirini-Stavroula; Gorgoulis, Vassilis G; Newman, Timothy J; Blow, J Julian

    2016-09-27

    To prevent rereplication of genomic segments, the eukaryotic cell cycle is divided into two nonoverlapping phases. During late mitosis and G1 replication origins are "licensed" by loading MCM2-7 double hexamers and during S phase licensed replication origins activate to initiate bidirectional replication forks. Replication forks can stall irreversibly, and if two converging forks stall with no intervening licensed origin-a "double fork stall" (DFS)-replication cannot be completed by conventional means. We previously showed how the distribution of replication origins in yeasts promotes complete genome replication even in the presence of irreversible fork stalling. This analysis predicts that DFSs are rare in yeasts but highly likely in large mammalian genomes. Here we show that complementary strand synthesis in early mitosis, ultrafine anaphase bridges, and G1-specific p53-binding protein 1 (53BP1) nuclear bodies provide a mechanism for resolving unreplicated DNA at DFSs in human cells. When origin number was experimentally altered, the number of these structures closely agreed with theoretical predictions of DFSs. The 53BP1 is preferentially bound to larger replicons, where the probability of DFSs is higher. Loss of 53BP1 caused hypersensitivity to licensing inhibition when replication origins were removed. These results provide a striking convergence of experimental and theoretical evidence that unreplicated DNA can pass through mitosis for resolution in the following cell cycle.

  3. Unreplicated DNA remaining from unperturbed S phases passes through mitosis for resolution in daughter cells

    PubMed Central

    Moreno, Alberto; Carrington, Jamie T.; Al Mamun, Mohammed; Haagensen, Emma J.; Komseli, Eirini-Stavroula; Gorgoulis, Vassilis G.; Newman, Timothy J.; Blow, J. Julian

    2016-01-01

    To prevent rereplication of genomic segments, the eukaryotic cell cycle is divided into two nonoverlapping phases. During late mitosis and G1 replication origins are “licensed” by loading MCM2-7 double hexamers and during S phase licensed replication origins activate to initiate bidirectional replication forks. Replication forks can stall irreversibly, and if two converging forks stall with no intervening licensed origin—a “double fork stall” (DFS)—replication cannot be completed by conventional means. We previously showed how the distribution of replication origins in yeasts promotes complete genome replication even in the presence of irreversible fork stalling. This analysis predicts that DFSs are rare in yeasts but highly likely in large mammalian genomes. Here we show that complementary strand synthesis in early mitosis, ultrafine anaphase bridges, and G1-specific p53-binding protein 1 (53BP1) nuclear bodies provide a mechanism for resolving unreplicated DNA at DFSs in human cells. When origin number was experimentally altered, the number of these structures closely agreed with theoretical predictions of DFSs. The 53BP1 is preferentially bound to larger replicons, where the probability of DFSs is higher. Loss of 53BP1 caused hypersensitivity to licensing inhibition when replication origins were removed. These results provide a striking convergence of experimental and theoretical evidence that unreplicated DNA can pass through mitosis for resolution in the following cell cycle. PMID:27516545

  4. O-Glycosylation of Axl2/Bud10p by Pmt4p Is Required for Its Stability, Localization, and Function in Daughter Cells

    PubMed Central

    Sanders, Sylvia L.; Gentzsch, Martina; Tanner, Widmar; Herskowitz, Ira

    1999-01-01

    Cells of the yeast Saccharomyces cerevisiae choose bud sites in a manner that is dependent upon cell type: a and α cells select axial sites; a/α cells utilize bipolar sites. Mutants specifically defective in axial budding were isolated from an α strain using pseudohyphal growth as an assay. We found that a and α mutants defective in the previously identified PMT4 gene exhibit unipolar, rather than axial budding: mother cells choose axial bud sites, but daughter cells do not. PMT4 encodes a protein mannosyl transferase (pmt) required for O-linked glycosylation of some secretory and cell surface proteins (Immervoll, T., M. Gentzsch, and W. Tanner. 1995. Yeast. 11:1345–1351). We demonstrate that Axl2/Bud10p, which is required for the axial budding pattern, is an O-linked glycoprotein and is incompletely glycosylated, unstable, and mislocalized in cells lacking PMT4. Overexpression of AXL2 can partially restore proper bud-site selection to pmt4 mutants. These data indicate that Axl2/Bud10p is glycosylated by Pmt4p and that O-linked glycosylation increases Axl2/ Bud10p activity in daughter cells, apparently by enhancing its stability and promoting its localization to the plasma membrane. PMID:10366591

  5. Origin of Individuality of Two Daughter Cells during the Division Process Examined by the Simultaneous Measurement of Growth and Swimming Property Using an On-Chip Single-Cell Cultivation System

    PubMed Central

    Umehara, Senkei; Inoue, Ippei; Wakamoto, Yuichi; Yasuda, Kenji

    2007-01-01

    We examined the origin of individuality of two daughter cells born from an isolated single Escherichia coli mother cell during its cell division process by monitoring the change in its swimming behavior and tumbling frequency using an on-chip single-cell cultivation system. By keeping the isolated condition of an observed single cell, we compared its growth and swimming property within a generation and over up to seven generations. It revealed that running speed decreased as cell length smoothly increased within each generation, whereas tumbling frequency fluctuated among generations. Also found was an extraordinary tumbling mode characterized by the prolonged duration of pausing in predivisional cells after cell constriction. The observed prolonged pausing may imply the coexistence of two distinct control systems in a predivisional cell, indicating that individuality of daughter cells emerges after a mother cell initiates constriction and before it gets physically separated into two new cell bodies. PMID:17496044

  6. Tethered Magnets Are the Key to Magnetotaxis: Direct Observations of Magnetospirillum magneticum AMB-1 Show that MamK Distributes Magnetosome Organelles Equally to Daughter Cells

    PubMed Central

    Kiyokawa, Ayako; Uesugi, Chika; Kikuchi, Yousuke; Oestreicher, Zachery; Morii, Kaori; Eguchi, Yukako; Fukumori, Yoshihiro

    2017-01-01

    ABSTRACT Magnetotactic bacteria are a unique group of bacteria that synthesize a magnetic organelle termed the magnetosome, which they use to assist with their magnetic navigation in a specific type of bacterial motility called magneto-aerotaxis. Cytoskeletal filaments consisting of the actin-like protein MamK are associated with the magnetosome chain. Previously, the function of MamK was thought to be in positioning magnetosome organelles; this was proposed based on observations via electron microscopy still images. Here, we conducted live-cell time-lapse fluorescence imaging analyses employing highly inclined and laminated optical sheet microscopy, and these methods enabled us to visualize detailed dynamic movement of magnetosomes in growing cells during the entire cell cycle with high-temporal resolution and a high signal/noise ratio. We found that the MamK cytoskeleton anchors magnetosomes through a mechanism that requires MamK-ATPase activity throughout the cell cycle to prevent simple diffusion of magnetosomes within the cell. We concluded that the static chain-like arrangement of the magnetosomes is required to precisely and consistently segregate the magnetosomes to daughter cells. Thus, the daughter cells inherit a functional magnetic sensor that mediates magneto-reception. PMID:28790202

  7. An inhibitor of yeast cyclin-dependent protein kinase plays an important role in ensuring the genomic integrity of daughter cells.

    PubMed Central

    Nugroho, T T; Mendenhall, M D

    1994-01-01

    The gene encoding a 40-kDa protein, previously studied as a substrate and inhibitor of the yeast cyclin-dependent protein kinase, Cdc28, has been cloned. The DNA sequence reveals that p40 is a highly charged protein of 32,187 Da with no significant homology to other proteins. Overexpression of the gene encoding p40, SIC1, produces cells with an elongated but morphology similar to that of cells with depleted levels of the CLB gene products, suggesting that p40 acts as an inhibitor of Cdc28-Clb complexes in vivo. A SIC1 deletion is viable and has highly increased frequencies of broken and lost chromosomes. The deletion strain segregates out many dead cells that are primarily arrested at the G2 checkpoint in an asymmetric fashion. Only daughters and young mothers display the lethal defect, while experienced mothers appear to grow normally. These results suggest that negative regulation of Cdc28 protein kinase activity by p40 is important for faithful segregation of chromosomes to daughter cells. Images PMID:8164683

  8. Clonal mature adipocyte production of proliferative-competent daughter cells requires lipid export prior to cell division

    USDA-ARS?s Scientific Manuscript database

    Numerous in vitro observations have been published to show that mature adipocytes may resume proliferation and begin to populate the adipofibroblast fraction or form other cell types. In the present study, we evaluated clonal cultures of mature pig-derived adipocytes as they began to reestablish the...

  9. Compartmentalization of ER-Bound Chaperone Confines Protein Deposit Formation to the Aging Yeast Cell.

    PubMed

    Saarikangas, Juha; Caudron, Fabrice; Prasad, Rupali; Moreno, David F; Bolognesi, Alessio; Aldea, Martí; Barral, Yves

    2017-03-20

    In order to produce rejuvenated daughters, dividing budding yeast cells confine aging factors, including protein aggregates, to the aging mother cell. The asymmetric inheritance of these protein deposits is mediated by organelle and cytoskeletal attachment and by cell geometry. Yet it remains unclear how deposit formation is restricted to the aging lineage. Here, we show that selective membrane anchoring and the compartmentalization of the endoplasmic reticulum (ER) membrane confine protein deposit formation to aging cells during division. Supporting the idea that the age-dependent deposit forms through coalescence of smaller aggregates, two deposits rapidly merged when placed in the same cell by cell-cell fusion. The deposits localized to the ER membrane, primarily to the nuclear envelope (NE). Strikingly, weakening the diffusion barriers that separate the ER membrane into mother and bud compartments caused premature formation of deposits in the daughter cells. Detachment of the Hsp40 protein Ydj1 from the ER membrane elicited a similar phenotype, suggesting that the diffusion barriers and farnesylated Ydj1 functioned together to confine protein deposit formation to mother cells during division. Accordingly, fluorescence correlation spectroscopy measurements in dividing cells indicated that a slow-diffusing, possibly client-bound Ydj1 fraction was asymmetrically enriched in the mother compartment. This asymmetric distribution depended on Ydj1 farnesylation and intact diffusion barriers. Taking these findings together, we propose that ER-anchored Ydj1 binds deposit precursors and prevents them from spreading into daughter cells during division by subjecting them to the ER diffusion barriers. This ensures that the coalescence of precursors into a single deposit is restricted to the aging lineage.

  10. Tethered Magnets Are the Key to Magnetotaxis: Direct Observations of Magnetospirillum magneticum AMB-1 Show that MamK Distributes Magnetosome Organelles Equally to Daughter Cells.

    PubMed

    Taoka, Azuma; Kiyokawa, Ayako; Uesugi, Chika; Kikuchi, Yousuke; Oestreicher, Zachery; Morii, Kaori; Eguchi, Yukako; Fukumori, Yoshihiro

    2017-08-08

    Magnetotactic bacteria are a unique group of bacteria that synthesize a magnetic organelle termed the magnetosome, which they use to assist with their magnetic navigation in a specific type of bacterial motility called magneto-aerotaxis. Cytoskeletal filaments consisting of the actin-like protein MamK are associated with the magnetosome chain. Previously, the function of MamK was thought to be in positioning magnetosome organelles; this was proposed based on observations via electron microscopy still images. Here, we conducted live-cell time-lapse fluorescence imaging analyses employing highly inclined and laminated optical sheet microscopy, and these methods enabled us to visualize detailed dynamic movement of magnetosomes in growing cells during the entire cell cycle with high-temporal resolution and a high signal/noise ratio. We found that the MamK cytoskeleton anchors magnetosomes through a mechanism that requires MamK-ATPase activity throughout the cell cycle to prevent simple diffusion of magnetosomes within the cell. We concluded that the static chain-like arrangement of the magnetosomes is required to precisely and consistently segregate the magnetosomes to daughter cells. Thus, the daughter cells inherit a functional magnetic sensor that mediates magneto-reception.IMPORTANCE Half a century ago, bacterial cells were considered a simple "bag of enzymes"; only recently have they been shown to comprise ordered complexes of macromolecular structures, such as bacterial organelles and cytoskeletons, similar to their eukaryotic counterparts. In eukaryotic cells, the positioning of organelles is regulated by cytoskeletal elements. However, the role of cytoskeletal elements in the positioning of bacterial organelles, such as magnetosomes, remains unclear. Magnetosomes are associated with cytoskeletal filaments that consist of the actin-like protein MamK. In this study, we focused on how the MamK cytoskeleton regulates the dynamic movement of magnetosome organelles

  11. The Bacterial Septal Ring Protein RlpA is a Lytic Transglycosylase that Contributes to Rod Shape and Daughter Cell Separation in Pseudomonas aeruginosa

    PubMed Central

    Jorgenson, Matthew A.; Chen, Yan; Yahashiri, Atsushi; Popham, David L.; Weiss, David S.

    2014-01-01

    Summary Rare lipoprotein A (RlpA) is a widely-conserved outer membrane protein of unknown function that has previously only been studied in Escherichia coli, where it localizes to the septal ring and scattered foci along the lateral wall, but mutants have no phenotypic change. Here we show rlpA mutants of Pseudomonas aeruginosa form chains of short, fat cells when grown in low osmotic strength media. These morphological defects indicate RlpA is needed for efficient separation of daughter cells and maintenance of rod shape. Analysis of peptidoglycan sacculi from an rlpA deletion mutant revealed increased tetra and hexasaccharides that lack stem peptides (hereafter called “naked glycans”). Incubation of these sacculi with purified RlpA resulted in release of naked glycans containing 1,6-anhydro N-acetylmuramic acid ends. RlpA did not degrade sacculi from wild-type cells unless the sacculi were subjected to a limited digestion with an amidase to remove some of the stem peptides. Thus, RlpA is a lytic transglycosylase with a strong preference for naked glycan strands. We propose that RlpA activity is regulated in vivo by substrate availability, and that amidases and RlpA work in tandem to degrade peptidoglycan in the division septum and lateral wall. PMID:24806796

  12. Mother-daughter asymmetry of pH underlies aging and rejuvenation in yeast.

    PubMed

    Henderson, Kiersten A; Hughes, Adam L; Gottschling, Daniel E

    2014-09-04

    Replicative aging in yeast is asymmetric-mother cells age but their daughter cells are rejuvenated. Here we identify an asymmetry in pH between mother and daughter cells that underlies aging and rejuvenation. Cytosolic pH increases in aging mother cells, but is more acidic in daughter cells. This is due to the asymmetric distribution of the major regulator of cytosolic pH, the plasma membrane proton ATPase (Pma1). Pma1 accumulates in aging mother cells, but is largely absent from nascent daughter cells. We previously found that acidity of the vacuole declines in aging mother cells and limits lifespan, but that daughter cell vacuoles re-acidify. We find that Pma1 activity antagonizes mother cell vacuole acidity by reducing cytosolic protons. However, the inherent asymmetry of Pma1 increases cytosolic proton availability in daughter cells and facilitates vacuole re-acidification and rejuvenation.

  13. Lyme disease and relapsing fever Borrelia elongate through zones of peptidoglycan synthesis that mark division sites of daughter cells

    PubMed Central

    Jutras, Brandon Lyon; Scott, Molly; Parry, Bradley; Biboy, Jacob; Gray, Joe; Vollmer, Waldemar; Jacobs-Wagner, Christine

    2016-01-01

    Agents that cause Lyme disease, relapsing fever, leptospirosis, and syphilis belong to the phylum Spirochaetae—a unique lineage of bacteria most known for their long, spiral morphology. Despite the relevance to human health, little is known about the most fundamental aspects of spirochete growth. Here, using quantitative microscopy to track peptidoglycan cell-wall synthesis, we found that the Lyme disease spirochete Borrelia burgdorferi displays a complex pattern of growth. B. burgdorferi elongates from discrete zones that are both spatially and temporally regulated. In addition, some peptidoglycan incorporation occurs along the cell body, with the notable exception of a large region at the poles. Newborn cells inherit a highly active zone of peptidoglycan synthesis at midcell that contributes to elongation for most of the cell cycle. Concomitant with the initiation of nucleoid separation and cell constriction, second and third zones of elongation are established at the 1/4 and 3/4 cellular positions, marking future sites of division for the subsequent generation. Positioning of elongation zones along the cell is robust to cell length variations and is relatively precise over long distances (>30 µm), suggesting that cells ‟sense” relative, as opposed to absolute, cell length to establish zones of peptidoglycan synthesis. The transition from one to three zones of peptidoglycan growth during the cell cycle is also observed in relapsing fever Borrelia. However, this mode of growth does not extend to representative species from other spirochetal genera, suggesting that this distinctive growth mode represents an evolutionary divide in the spirochete phylum. PMID:27506799

  14. Interplay between the dividing cell and its neighbors regulates adherens junction formation during cytokinesis in epithelial tissue.

    PubMed

    Herszterg, Sophie; Leibfried, Andrea; Bosveld, Floris; Martin, Charlotte; Bellaiche, Yohanns

    2013-02-11

    How adherens junctions (AJs) are formed upon cell division is largely unexplored. Here, we found that AJ formation is coordinated with cytokinesis and relies on an interplay between the dividing cell and its neighbors. During contraction of the cytokinetic ring, the neighboring cells locally accumulate Myosin II and produce the cortical tension necessary to set the initial geometry of the daughter cell interface. However, the neighboring cell membranes impede AJ formation. Upon midbody formation and concomitantly to neighboring cell withdrawal, Arp2/3-dependent actin polymerization oriented by the midbody maintains AJ geometry and regulates AJ final length and the epithelial cell arrangement upon division. We propose that cytokinesis in epithelia is a multicellular process, whereby the cooperative actions of the dividing cell and its neighbors define a two-tiered mechanism that spatially and temporally controls AJ formation while maintaining tissue cohesiveness.

  15. Segrosome Complex Formation during DNA Trafficking in Bacterial Cell Division.

    PubMed

    Oliva, María A

    2016-01-01

    Bacterial extrachromosomal DNAs often contribute to virulence in pathogenic organisms or facilitate adaptation to particular environments. The transmission of genetic information from one generation to the next requires sufficient partitioning of DNA molecules to ensure that at least one copy reaches each side of the division plane and is inherited by the daughter cells. Segregation of the bacterial chromosome occurs during or after replication and probably involves a strategy in which several protein complexes participate to modify the folding pattern and distribution first of the origin domain and then of the rest of the chromosome. Low-copy number plasmids rely on specialized partitioning systems, which in some cases use a mechanism that show striking similarity to eukaryotic DNA segregation. Overall, there have been multiple systems implicated in the dynamic transport of DNA cargo to a new cellular position during the cell cycle but most seem to share a common initial DNA partitioning step, involving the formation of a nucleoprotein complex called the segrosome. The particular features and complex topologies of individual segrosomes depend on both the nature of the DNA binding protein involved and on the recognized centromeric DNA sequence, both of which vary across systems. The combination of in vivo and in vitro approaches, with structural biology has significantly furthered our understanding of the mechanisms underlying DNA trafficking in bacteria. Here, I discuss recent advances and the molecular details of the DNA segregation machinery, focusing on the formation of the segrosome complex.

  16. Identification of a multifunctional protein, PhaM, that determines number, surface to volume ratio, subcellular localization and distribution to daughter cells of poly(3-hydroxybutyrate), PHB, granules in Ralstonia eutropha H16.

    PubMed

    Pfeiffer, Daniel; Wahl, Andreas; Jendrossek, Dieter

    2011-11-01

    A two-hybrid approach was applied to screen for proteins with the ability to interact with PHB synthase (PhaC1) of Ralstonia eutropha. The H16_A0141 gene (phaM) was identified in the majority of positive clones. PhaM (26.6 kDa) strongly interacted with PhaC1 and with phasin PhaP5 but not with PhaP1 or other PHB granule-associated proteins. A ΔphaM mutant accumulated only one or two large PHB granules instead of three to six medium-sized PHB granules of the wild type, and distribution of granules to daughter cells was disordered. All three phenotypes (number, size and distribution of PHB granules) were reversed by reintroduction of phaM. Purified PhaM revealed DNA-binding properties in gel mobility shift experiments. Expression of a fusion of the yellow fluorescent protein (eYfp) with PhaM resulted in formation of many small fluorescent granules that were bound to the nucleoid region. Remarkably, an eYfp-PhaP5 fusion localized at the cell poles in a PHB-negative background and overexpression of eYfp-PhaP5 in the wild type conferred binding of PHB granules to the cell poles. In conclusion, subcellular localization of PHB granules in R. eutropha depends on a concerted expression of at least three PHB granule-associated proteins, namely PhaM, PhaP5 and PHB synthase PhaC1.

  17. Autophagosome formation in mammalian cells.

    PubMed

    Burman, Chloe; Ktistakis, Nicholas T

    2010-12-01

    Autophagy is a fundamental intracellular trafficking pathway conserved from yeast to mammals. It is generally thought to play a pro-survival role, and it can be up regulated in response to both external and intracellular factors, including amino acid starvation, growth factor withdrawal, low cellular energy levels, endoplasmic reticulum (ER) stress, hypoxia, oxidative stress, pathogen infection, and organelle damage. During autophagy initiation a portion of the cytosol is surrounded by a flat membrane sheet known as the isolation membrane or phagophore. The isolation membrane then elongates and seals itself to form an autophagosome. The autophagosome fuses with normal endocytic traffic to mature into a late autophagosome, before fusing with lysosomes. The molecular machinery that enables formation of an autophagosome in response to the various autophagy stimuli is almost completely identified in yeast and-thanks to the observed conservation-is also being rapidly elucidated in higher eukaryotes including mammals. What are less clear and currently under intense investigation are the mechanism by which these various autophagy components co-ordinate in order to generate autophagosomes. In this review, we will discuss briefly the fundamental importance of autophagy in various pathophysiological states and we will then review in detail the various players in early autophagy. Our main thesis will be that a conserved group of heteromeric protein complexes and a relatively simple signalling lipid are responsible for the formation of autophagosomes in mammalian cells.

  18. The Levels of "Rappaccini's Daughter."

    ERIC Educational Resources Information Center

    Hands, Charles B.

    1970-01-01

    Nathaniel Hawthorne's short story "Rappaccini's Daughter" reflects the author's view that inherent in the human dilemma are ambiguous ironies which cannot be resolved. Although Hawthorne (unlike Ralph Waldo Emerson) perceives evil as an extraordinarily potent force, he offers no clear moral solutions in this story, but examines various…

  19. Mother and Daughter Reports about Upward Transfers

    ERIC Educational Resources Information Center

    Lin, I-Fen

    2008-01-01

    Using 619 mother-daughter dyads interviewed in the 1997 National Longitudinal Surveys of Mature Women and Young Women, this study examines the assistance that adult daughters provide to their mothers and its covariates. Mothers and daughters have low levels of agreement on transfers. Using mothers' reports identifies different covariates of…

  20. Turner phenotype in mother and daughter.

    PubMed

    Muasher, S; Baramki, T A; Diggs, E S

    1980-12-01

    Two females are described, mother and daughter, who had the Turner phenotype and spontaneous sexual development. The mother is short and had ovulatory menstrual cycles, normal breast development, X-chromatin negative buccal smear, 45,X chromosomal pattern in her peripheral blood lymphocytes, and 45,X/46,X,r(X) mosaicism in her skin, with the majority of the cells (85%) showing X monosomy. She had a successful uncomplicated pregnancy at the age of 25 years. The daughter is short and had spontaneous sexual development, including menstruation at the age of 15 years. Her buccal smear was X-chromatin negative and karyotypes from peripheral blood lymphocytes and skin fibroblasts showed a 45,X chromosome constitution. Her menstrual cycles are irregular and, most probably, anovulatory. She has a horseshoe kidney. Six women with a 45, X chromosome complement are known to have delivered normal infants with no chromosomal abnormality. Five children with 45,X mosaicism have been born to mothers with 45,X mosaicism; all had a 46,XX cell line as well. This is the first report of a 45,X female born to a mother with mosaicism composed of 2 abnormal cell lines, 1 with X monosomy and 1 with a ring X chromosome.

  1. Positioning of polarity formation by extracellular signaling during asymmetric cell division.

    PubMed

    Seirin Lee, Sungrim

    2016-07-07

    Anterior-posterior (AP) polarity formation of cell membrane proteins plays a crucial role in determining cell asymmetry, which ultimately generates cell diversity. In Caenorhabditis elegans, a single fertilized egg cell (P0), its daughter cell (P1), and the germline precursors (P2 and P3 cells) form two exclusive domains of different PAR proteins on the membrane along the anterior-posterior axis. However, the phenomenon of polarity reversal has been observed in which the axis of asymmetric cell division of the P2 and P3 cells is formed in an opposite manner to that of the P0 and P1 cells. The extracellular signal MES-1/SRC-1 has been shown to induce polarity reversal, but the detailed mechanism remains elusive. Here, using a mathematical model, I explore the mechanism by which MES-1/SRC-1 signaling can induce polarity reversal and ultimately affect the process of polarity formation. I show that a positive correlation between SRC-1 and the on-rate of PAR-2 is the essential mechanism underlying polarity reversal, providing a mathematical basis for the orientation of cell polarity patterns.

  2. Drosophila neuroblasts as a new model for the study of stem cell self-renewal and tumour formation

    PubMed Central

    Li, Song; Wang, Hongyan; Groth, Casper

    2014-01-01

    Drosophila larval brain stem cells (neuroblasts) have emerged as an important model for the study of stem cell asymmetric division and the mechanisms underlying the transformation of neural stem cells into tumour-forming cancer stem cells. Each Drosophila neuroblast divides asymmetrically to produce a larger daughter cell that retains neuroblast identity, and a smaller daughter cell that is committed to undergo differentiation. Neuroblast self-renewal and differentiation are tightly controlled by a set of intrinsic factors that regulate ACD (asymmetric cell division). Any disruption of these two processes may deleteriously affect the delicate balance between neuroblast self-renewal and progenitor cell fate specification and differentiation, causing neuroblast overgrowth and ultimately lead to tumour formation in the fly. In this review, we discuss the mechanisms underlying Drosophila neural stem cell self-renewal and differentiation. Furthermore, we highlight emerging evidence in support of the notion that defects in ACD in mammalian systems, which may play significant roles in the series of pathogenic events leading to the development of brain cancers. PMID:24965943

  3. Silicon Formation for Solar Cells

    NASA Technical Reports Server (NTRS)

    Sancier, K.

    1985-01-01

    Highly pure silicon obtained for solar cells by proposed technique that sprays liquid-sodium droplets into SiF4 gas. Resulting freely flowing powder of silicon and sodium fluoride will not adhere to reactor walls and easily transferred to melt separator to recover silicon.

  4. Direct formate fuel cells: A review

    NASA Astrophysics Data System (ADS)

    An, L.; Chen, R.

    2016-07-01

    Direct formate fuel cells (DFFC), which convert the chemical energy stored in formate directly into electricity, are recently attracting more attention, primarily because of the use of the carbon-neutral fuel and the low-cost electrocatalytic and membrane materials. As an emerging energy technology, the DFFC has made a rapid progress in recent years (currently, the state-of-the-art power density is 591 mW cm-2 at 60 °C). This article provides a review of past research on the development of this type of fuel cell, including the working principle, mechanisms and materials of the electrocatalytic oxidation of formate, singe-cell designs and performance, as well as innovative system designs. In addition, future perspectives with regard to the development of this fuel cell system are also highlighted.

  5. Characterization and Localization of Insoluble Organic Matrices Associated with Diatom Cell Walls: Insight into Their Roles during Cell Wall Formation

    PubMed Central

    Tesson, Benoit; Hildebrand, Mark

    2013-01-01

    Organic components associated with diatom cell wall silica are important for the formation, integrity, and function of the cell wall. Polysaccharides are associated with the silica, however their localization, structure, and function remain poorly understood. We used imaging and biochemical approaches to describe in detail characteristics of insoluble organic components associated with the cell wall in 5 different diatom species. Results show that an insoluble organic matrix enriched in mannose, likely the diatotepum, is localized on the proximal surface of the silica cell wall. We did not identify any organic matrix embedded within the silica. We also identified a distinct material consisting of glucose polymer with variable localization depending on the species. In some species this component was directly involved in the morphogenesis of silica structure while in others it appeared to be only a structural component of the cell wall. A novel glucose-rich structure located between daughter cells during division was also identified. This work for the first time correlates the structure, composition, and localization of insoluble organic matrices associated with diatom cell walls. Additionally we identified a novel glucose polymer and characterized its role during silica structure formation. PMID:23626714

  6. Mast cells mediate malignant pleural effusion formation.

    PubMed

    Giannou, Anastasios D; Marazioti, Antonia; Spella, Magda; Kanellakis, Nikolaos I; Apostolopoulou, Hara; Psallidas, Ioannis; Prijovich, Zeljko M; Vreka, Malamati; Zazara, Dimitra E; Lilis, Ioannis; Papaleonidopoulos, Vassilios; Kairi, Chrysoula A; Patmanidi, Alexandra L; Giopanou, Ioanna; Spiropoulou, Nikolitsa; Harokopos, Vaggelis; Aidinis, Vassilis; Spyratos, Dionisios; Teliousi, Stamatia; Papadaki, Helen; Taraviras, Stavros; Snyder, Linda A; Eickelberg, Oliver; Kardamakis, Dimitrios; Iwakura, Yoichiro; Feyerabend, Thorsten B; Rodewald, Hans-Reimer; Kalomenidis, Ioannis; Blackwell, Timothy S; Agalioti, Theodora; Stathopoulos, Georgios T

    2015-06-01

    Mast cells (MCs) have been identified in various tumors; however, the role of these cells in tumorigenesis remains controversial. Here, we quantified MCs in human and murine malignant pleural effusions (MPEs) and evaluated the fate and function of these cells in MPE development. Evaluation of murine MPE-competent lung and colon adenocarcinomas revealed that these tumors actively attract and subsequently degranulate MCs in the pleural space by elaborating CCL2 and osteopontin. MCs were required for effusion development, as MPEs did not form in mice lacking MCs, and pleural infusion of MCs with MPE-incompetent cells promoted MPE formation. Once homed to the pleural space, MCs released tryptase AB1 and IL-1β, which in turn induced pleural vasculature leakiness and triggered NF-κB activation in pleural tumor cells, thereby fostering pleural fluid accumulation and tumor growth. Evaluation of human effusions revealed that MCs are elevated in MPEs compared with benign effusions. Moreover, MC abundance correlated with MPE formation in a human cancer cell-induced effusion model. Treatment of mice with the c-KIT inhibitor imatinib mesylate limited effusion precipitation by mouse and human adenocarcinoma cells. Together, the results of this study indicate that MCs are required for MPE formation and suggest that MC-dependent effusion formation is therapeutically addressable.

  7. Mutagenicity of radon and radon daughters

    SciTech Connect

    Evans, H.H.

    1991-01-01

    The objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose rate dependence and the nature of the DNA lesion will be studied, using the thymidine kinase and HPRT loci to measure mutation frequency. A deficiency in DNA repair is shown to lead to a greater proportion of mutants with intergenic lesions. The cytotoxic effects of radon and its daughters are similar in human TK6 lymphoblasts and mouse L5178Y lymphoblasts, the cell line used in previous experiments. The results of molecular analysis of four spontaneous and 25 X-radiation induced HPRT{sup {minus}} mutants. Eleven radon-induced HPRT{sup {minus}} mutants have been isolated, and will be analyzed in a similar fashion. 9 figs.

  8. Mutagenicity of radon and radon daughters

    NASA Astrophysics Data System (ADS)

    Evans, H. H.

    The objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose rate dependence and the nature of the DNA lesion will be studied, using the thymidine kinase and HPRT loci to measure mutation frequency. A deficiency in DNA repair is shown to lead to a greater proportion of mutants with intergenic lesions. The cytotoxic effects of radon and its daughters are similar in human TK6 lymphoblasts and mouse L5178Y lymphoblasts, the cell line used in previous experiments. The results of molecular analysis of four spontaneous and 25 X-radiation induced HPRT(-) mutants. Eleven radon-induced HPRT(-) mutants have been isolated, and will be analyzed in a similar fashion.

  9. Mast cells mediate malignant pleural effusion formation

    PubMed Central

    Giannou, Anastasios D.; Marazioti, Antonia; Spella, Magda; Kanellakis, Nikolaos I.; Apostolopoulou, Hara; Psallidas, Ioannis; Prijovich, Zeljko M.; Vreka, Malamati; Zazara, Dimitra E.; Lilis, Ioannis; Papaleonidopoulos, Vassilios; Kairi, Chrysoula A.; Patmanidi, Alexandra L.; Giopanou, Ioanna; Spiropoulou, Nikolitsa; Harokopos, Vaggelis; Aidinis, Vassilis; Spyratos, Dionisios; Teliousi, Stamatia; Papadaki, Helen; Taraviras, Stavros; Snyder, Linda A.; Eickelberg, Oliver; Kardamakis, Dimitrios; Iwakura, Yoichiro; Feyerabend, Thorsten B.; Rodewald, Hans-Reimer; Kalomenidis, Ioannis; Blackwell, Timothy S.; Agalioti, Theodora; Stathopoulos, Georgios T.

    2015-01-01

    Mast cells (MCs) have been identified in various tumors; however, the role of these cells in tumorigenesis remains controversial. Here, we quantified MCs in human and murine malignant pleural effusions (MPEs) and evaluated the fate and function of these cells in MPE development. Evaluation of murine MPE-competent lung and colon adenocarcinomas revealed that these tumors actively attract and subsequently degranulate MCs in the pleural space by elaborating CCL2 and osteopontin. MCs were required for effusion development, as MPEs did not form in mice lacking MCs, and pleural infusion of MCs with MPE-incompetent cells promoted MPE formation. Once homed to the pleural space, MCs released tryptase AB1 and IL-1β, which in turn induced pleural vasculature leakiness and triggered NF-κB activation in pleural tumor cells, thereby fostering pleural fluid accumulation and tumor growth. Evaluation of human effusions revealed that MCs are elevated in MPEs compared with benign effusions. Moreover, MC abundance correlated with MPE formation in a human cancer cell–induced effusion model. Treatment of mice with the c-KIT inhibitor imatinib mesylate limited effusion precipitation by mouse and human adenocarcinoma cells. Together, the results of this study indicate that MCs are required for MPE formation and suggest that MC-dependent effusion formation is therapeutically addressable. PMID:25915587

  10. Differential spheroid formation by oral cancer cells.

    PubMed

    Lee, Carlin; Lee, Casey; Atakilit, Amha; Siu, Amanda; Ramos, Daniel M

    2014-12-01

    Squamous cell carcinomas (SCC) make up 96% of all oral cancers. Most laboratory SCC studies grow cells as a monolayer, which does not accurately represent the disease in vivo. We used a more relevant multicellular spheroid (MCS) model to study this disease. The SCC9β6KDFyn cell line, which expresses full-length β6 and a kinase dead Fyn formed the largest MCS. Cell adhesive properties are dynamic and N-cadherin was increased in the largest MCS. c-Raf mediates the survival of tumor cells and was consistently expressed both in monolayers and in the MCS by SCC9β6D1 cells which lack the β6 cytoplasmic tail and, do not activate Fyn. SCC9β6KDFyn cells also express high levels of c-Raf when grown as spheroids in which Fyn suppression stimulates MCS formation. Tumor microenvironment and growth patterns modulate cell behavior and suppression of Fyn kinase may promote MCS growth.

  11. Functional modification of adipocytes by grape seed extract impairs their pro-tumorigenic signaling on colon cancer stem cells and the daughter cancer cells

    PubMed Central

    Raina, Komal; Agarwal, Rajesh

    2014-01-01

    With global rise in obesity, it is imperative that we identify obesity-driven factors that increase growth and progression of colorectal cancer (CRC), and also discover and develop agents with anti-CRC efficacy under obese conditions. Here in, we investigated grape seed extract (GSE), a well-defined agent with both preventive and anti-CRC efficacy, for its potential to impair pro-tumorigenic signaling of adipocytes on CRC/colon cancer stem cells (CSCs) and associated molecular mechanisms, to control CRC under obese conditions. GSE treatment significantly decreased the growth and invasion promoting effects of both mouse and human adipocytes on CRC cells. Moreover, GSE exerted a direct inhibitory effect, as well as it strongly reduced the growth promoting signals of adipocytes, on colon CSCs. These GSE effects were associated with a decrease in both mRNA and protein levels of various CSC-associated molecules. Notably, GSE effects on adipocytes were not due to changes in lipid content, but by inducing the ‘browning’ of adipocytes as evidenced by an increase in UCP-1 mRNA level and mitochondriogenesis. Together, these findings, for the first time, suggest the ability of GSE to induce ‘brown remodeling’ of white adipocytes, which causes functional modification of adipocytes thus impairing their pro-tumorigenic signals on colon CSCs/CRC cells. PMID:25294814

  12. Functional modification of adipocytes by grape seed extract impairs their pro-tumorigenic signaling on colon cancer stem cells and the daughter cancer cells.

    PubMed

    Kumar, Sushil; Kumar, Dileep; Raina, Komal; Agarwal, Rajesh; Agarwal, Chapla

    2014-10-30

    With global rise in obesity, it is imperative that we identify obesity-driven factors that increase growth and progression of colorectal cancer (CRC), and also discover and develop agents with anti-CRC efficacy under obese conditions. Here in, we investigated grape seed extract (GSE), a well-defined agent with both preventive and anti-CRC efficacy, for its potential to impair pro-tumorigenic signaling of adipocytes on CRC/colon cancer stem cells (CSCs) and associated molecular mechanisms, to control CRC under obese conditions. GSE treatment significantly decreased the growth and invasion promoting effects of both mouse and human adipocytes on CRC cells. Moreover, GSE exerted a direct inhibitory effect, as well as it strongly reduced the growth promoting signals of adipocytes, on colon CSCs. These GSE effects were associated with a decrease in both mRNA and protein levels of various CSC-associated molecules. Notably, GSE effects on adipocytes were not due to changes in lipid content, but by inducing the 'browning' of adipocytes as evidenced by an increase in UCP-1 mRNA level and mitochondriogenesis. Together, these findings, for the first time, suggest the ability of GSE to induce 'brown remodeling' of white adipocytes, which causes functional modification of adipocytes thus impairing their pro-tumorigenic signals on colon CSCs/CRC cells.

  13. Associative memory cells: Formation, function and perspective

    PubMed Central

    Wang, Jin-Hui; Cui, Shan

    2017-01-01

    Associative learning and memory are common activities in life, and their cellular infrastructures constitute the basis of cognitive processes. Although neuronal plasticity emerges after memory formation, basic units and their working principles for the storage and retrieval of associated signals remain to be revealed. Current reports indicate that associative memory cells, through their mutual synapse innervations among the co-activated sensory cortices, are recruited to fulfill the integration, storage and retrieval of multiple associated signals, and serve associative thinking and logical reasoning. In this review, we aim to summarize associative memory cells in their formation, features and functional impacts. PMID:28408978

  14. The Toxoplasma gondii centrosome is the platform for internal daughter budding as revealed by a Nek1 kinase mutant.

    PubMed

    Chen, Chun-Ti; Gubbels, Marc-Jan

    2013-08-01

    The pathology and severity of toxoplasmosis results from the rapid replication cycle of the apicomplexan parasite Toxoplasma gondii. The tachyzoites divide asexually through endodyogeny, wherein two daughter cells bud inside the mother cell. Before mitosis is completed, the daughter buds form around the duplicated centrosomes and subsequently elongate to serve as the scaffold for organellogenesis and organelle partitioning. The molecular control mechanism of this process is poorly understood. Here, we characterized a T. gondii NIMA-related kinase (Nek) ortholog that was identified in a chemical mutagenesis screen. A temperature-sensitive mutant, V-A15, possesses a Cys316Arg mutation in TgNek1 (a novel mutant allele in Neks), which is responsible for growth defects at the restrictive temperature. Phenotypic analysis of V-A15 indicated that TgNek1 is essential for centrosome splitting, proper formation of daughter cells and faithful segregation of genetic material. In vitro kinase assays showed that the mutation abolishes the kinase activity of TgNek1. TgNek1 is recruited to the centrosome prior to its duplication and localizes on the duplicated centrosomes facing the spindle poles in a cell-cycle-dependent manner. Mutational analysis of the activation loop suggests that localization and activity are spatio-temporally regulated by differential phosphorylation. Collectively, our results identified a novel temperature-sensitive allele for a Nek kinase and highlight its essential function in centrosome splitting in Toxoplasma. Moreover, these results conclusively show for the first time that Toxoplasma bud assembly is facilitated by the centrosome because defective centrosome splitting results in single daughter cell budding.

  15. Cytoskeleton assembly in Toxoplasma gondii cell division

    PubMed Central

    Anderson-White, Brooke; Beck, Josh R.; Chen, Chun-Ti; Meissner, Markus; Bradley, Peter J.; Gubbels, Marc-Jan

    2014-01-01

    Cell division across members of the protozoan parasite phylum Apicomplexa displays a surprising diversity between different species as well as between different life stages of the same parasite. In most cases, infection of a host cell by a single parasite results in the formation of a polyploid cell from which individual daughters bud in a process dependent on a final round of mitosis. Unlike other apicomplexans, Toxoplasma gondii divides by a binary process consisting of internal budding that results in only two daughter cells per round of division. Since T. gondii is experimentally accessible and displays the simplest division mode, it has manifested itself as a model for apicomplexan daughter formation. Here we review newly emerging insights in the prominent role that assembly of the cortical cytoskeletal scaffold plays in the process of daughter parasite formation. PMID:22878103

  16. Genome-wide maps of polyadenylation reveal dynamic mRNA 3'-end formation in mammalian cell lineages.

    PubMed

    Wang, Li; Dowell, Robin D; Yi, Rui

    2013-03-01

    Post-transcriptional regulation, often mediated by miRNAs and RNA-binding proteins at the 3' untranslated regions (UTRs) of mRNAs, is implicated in important roles in the output of transcriptome. To decipher this layer of gene regulation, it is essential to measure global mRNA expression quantitatively in a 3'-UTR-specific manner. Here we establish an experimental and bioinformatics pipeline that simultaneously determines 3'-end formation by leveraging local nucleotide composition and quantitatively measures mRNA expression by sequencing polyadenylated transcripts. When applied to purified mouse embryonic skin stem cells and their daughter lineages, we identify 18,060 3' UTRs representing 12,739 distinct mRNAs that are abundantly expressed in the skin. We determine that ∼78% of UTRs are formed by using canonical A[A/U]UAAA polyadenylation signals, whereas ∼22% of UTRs use alternative signals. By comparing to relative and absolute mRNA abundance determined by qPCR, our RNA-seq approach can precisely measure mRNA fold-change and accurately determine the expression of mRNAs over four orders of magnitude. Surprisingly, only 829 out of 12,739 genes show differential 3'-end usage between embryonic skin stem cells and their immediate daughter cells, whereas the numbers increase to 933 genes when comparing embryonic skin stem cells with the more remotely related hair follicle cells. This suggests an evolving diversity instead of switch-like dynamics in 3'-end formation during development. Finally, core components of the miRNA pathway including Dicer, Dgcr8, Xpo5, and Argonautes show dynamic 3'-UTR formation patterns, indicating a self-regulatory mechanism. Together, our quantitative analysis reveals a dynamic picture of mRNA 3'-end formation in tissue stem cell lineages in vivo.

  17. My daughter's daughter: the tragedy of late stage miscarriage.

    PubMed

    Hughes, Tara

    2014-04-01

    This article sets out my observations of my daughter's difficult pregnancy and late-stage miscarriage. I share this information to raise awareness that the specialist support for women going through this is not always in place and doesn't fully prepare women for this experience. Even though this can be uncomfortable for maternity professionals, the care that women receive, especially during labour and birth, has a massive impact on them and their families. There are many opportunities for midwives to make a positive difference at this difficult time. My granddaughter, Jess, died at five months gestation and was later confirmed to have Turner Syndrome. Turner Syndrome is a chromosomal abnormality that only affects girls and is related to the partial or complete deletion of the X chromosome. Not all affected girls are miscarried and an estimated one in 2000 girls born in the UK has Turner Syndrome.

  18. The plant cell cycle: Pre-Replication complex formation and controls.

    PubMed

    Brasil, Juliana Nogueira; Costa, Carinne N Monteiro; Cabral, Luiz Mors; Ferreira, Paulo C G; Hemerly, Adriana S

    2017-03-16

    The multiplication of cells in all living organisms requires a tight regulation of DNA replication. Several mechanisms take place to ensure that the DNA is replicated faithfully and just once per cell cycle in order to originate through mitoses two new daughter cells that contain exactly the same information from the previous one. A key control mechanism that occurs before cells enter S phase is the formation of a pre-replication complex (pre-RC) that is assembled at replication origins by the sequential association of the origin recognition complex, followed by Cdt1, Cdc6 and finally MCMs, licensing DNA to start replication. The identification of pre-RC members in all animal and plant species shows that this complex is conserved in eukaryotes and, more importantly, the differences between kingdoms might reflect their divergence in strategies on cell cycle regulation, as it must be integrated and adapted to the niche, ecosystem, and the organism peculiarities. Here, we provide an overview of the knowledge generated so far on the formation and the developmental controls of the pre-RC mechanism in plants, analyzing some particular aspects in comparison to other eukaryotes.

  19. The plant cell cycle: Pre-Replication complex formation and controls

    PubMed Central

    Brasil, Juliana Nogueira; Costa, Carinne N. Monteiro; Cabral, Luiz Mors; Ferreira, Paulo C. G.; Hemerly, Adriana S.

    2017-01-01

    Abstract The multiplication of cells in all living organisms requires a tight regulation of DNA replication. Several mechanisms take place to ensure that the DNA is replicated faithfully and just once per cell cycle in order to originate through mitoses two new daughter cells that contain exactly the same information from the previous one. A key control mechanism that occurs before cells enter S phase is the formation of a pre-replication complex (pre-RC) that is assembled at replication origins by the sequential association of the origin recognition complex, followed by Cdt1, Cdc6 and finally MCMs, licensing DNA to start replication. The identification of pre-RC members in all animal and plant species shows that this complex is conserved in eukaryotes and, more importantly, the differences between kingdoms might reflect their divergence in strategies on cell cycle regulation, as it must be integrated and adapted to the niche, ecosystem, and the organism peculiarities. Here, we provide an overview of the knowledge generated so far on the formation and the developmental controls of the pre-RC mechanism in plants, analyzing some particular aspects in comparison to other eukaryotes. PMID:28304073

  20. Contribution of Vascular Cells to Neointimal Formation

    PubMed Central

    Yuan, Falei; Wang, Dong; Xu, Kang; Wang, Jixian; Zhang, Zhijun; Yang, Li; Yang, Guo-Yuan; Li, Song

    2017-01-01

    The de-differentiation and proliferation of smooth muscle cells (SMCs) are widely accepted as the major contributor to vascular remodeling. However, recent studies indicate that vascular stem cells (VSCs) also play an important role, but their relative contribution remains to be elucidated. In this study, we used genetic lineage tracing approach to further investigate the contribution of SMCs and VSCs to neointimal thickening in response to endothelium denudation injury or artery ligation. In vitro and in vivo analysis of MYH11-cre/Rosa-loxP-RFP mouse artery showed that SMCs proliferated at a much slower rate than non-SMCs. Upon denudation or ligation injury, two distinct types of neointima were identified: Type-I neointimal cells mainly involved SMCs, while Type II mainly involved non-SMCs. Using Sox10-cre/Rosa-loxP-LacZ mice, we found that Sox10+ cells were one of the cell sources in neointima. In addition, lineage tracing using Tie2-cre/Rosa-LoxP-RFP showed that endothelial cells also contributed to the neointimal formation, but rarely transdifferentiated into mesenchymal lineages. These results provide a novel insight into the contribution of vascular cells to neointima formation, and have significant impact on the development of more effective therapies that target specific vascular cell types. PMID:28060852

  1. [Altering of phragmoplast orientation as a result of excessive centrifugal movement in the absence of cell plate].

    PubMed

    Shamina, N V; Kovaleva, N M; Shatskaia, O A

    2006-01-01

    The inability of phragmoplast to stop its centrifugal movement after reaching the mother cell membrane is described in abnormal meiosis with the arrest of cell plate formation. The excess of phragmoplast expansion leads to rotation of the whole telophase figure (phragmoplast with daughter nuclei) within the cell through 90 degrees. It has been suggested that this phenomenon may occur because of a the lack of signal stopping cytokinesis. Such a signal arises due to formation of daughter cell membranes.

  2. Transport vesicle formation in plant cells.

    PubMed

    Hwang, Inhwan; Robinson, David G

    2009-12-01

    In protein trafficking, transport vesicles bud from donor compartments and carry cargo proteins to target compartments with which they fuse. Thus, vesicle formation is an essential step in protein trafficking. As for mammals, plant cells contain the three major types of vesicles: COPI, COPII, and CCV and the major molecular players in vesicle-mediated protein transport are also present. However, plant cells generally contain more isoforms of the coat proteins, ARF GTPases and their regulatory proteins, as well as SNAREs. In addition, plants have established some unique subfamilies, which may reflect plant cell-specific conditions such as the absence of an ER-Golgi intermediate compartment and the combined activities of the TGN and early endosome. Thus, even though we are still at an early stage in understanding the physiological function of these proteins, it is already clear that vesicle-mediated protein transport in plant cells displays both similarities as well as differences in animal cells.

  3. Raising Confident, Competent Daughters: Strategies for Parents.

    ERIC Educational Resources Information Center

    Ransome, Whitney, Ed.; And Others

    This booklet contains five essays designed to help parents raise confident, competent daughters. They focus on ways that parents can help their preadolescent and adolescent daughters: (1) speak up in class, articulate their thoughts, and speak with self-confidence in various academic and social situations; (2) develop an interest and aptitude for…

  4. Raising Confident, Competent Daughters: Strategies for Parents.

    ERIC Educational Resources Information Center

    Ransome, Whitney, Ed.; And Others

    This booklet contains five essays designed to help parents raise confident, competent daughters. They focus on ways that parents can help their preadolescent and adolescent daughters: (1) speak up in class, articulate their thoughts, and speak with self-confidence in various academic and social situations; (2) develop an interest and aptitude for…

  5. A hypothesis of target cell formation in sickle cell disease.

    PubMed

    Wong, P

    2016-08-01

    A fraction of erythrocytes appear as target cells in stained blood smears in sickle cell disease, due to a inheritance of the hemoglobin variant Hb S, polymerizing upon deoxygenation. These cells appear in a three dimension as thin cups. A process of their formation in this disease is proposed based on a band 3-based mechanism of the erythrocyte shape control, able to explain the erythrocyte echinocytosis by glucose depletion. It indicates that their formation is due to a stomatocytogenic slow outward transport of the dibasic form of endogenous Pi with an H(+) by band 3, promoted by the decrease of the Donnan ratio, which decreases cell pH and volume, attributed by a decrease of cell KCl concentration by the higher efflux of K(+)Cl(-) cotransport and Ca(2+) activation of the Gardos channel. Its implications are briefly discussed with respect to target cells per se, target cell formation in other hemoglobinopathies, acquired and inherited disorders of the lipid metabolism and dehydrated hereditary stomatocytosis as well as a stomatocyte presence in a double heterozygote of Hb S and Hb C and of an involvement of the process of target cell formation in acanthocytosis in acquired and inherited disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Continuum Theory of Dislocations: Cell Structure Formation

    NASA Astrophysics Data System (ADS)

    Limkumnerd, Surachate; Sethna, James P.

    2005-03-01

    Line-like topological defects inside metals are called dislocations. These dislocations in late stages of hardening form patterns called cell structures. We are developing a mesoscale theory for the formation of cell structures that systematically derives the order parameter fields and evolution laws from the conserved topological Burgers vector density or the Nye dislocation tensor. (In classical plasticity theories, describing scales large compared to these cells, one normally bypasses the complicated motions of the dislocations by supplying yield surface and plastic hardening function in order to determine the evolution of state variables.) Using Landau approach and a closure approximation, an evolution equation for the dislocation density tensor is obtained by employing simple symmetry arguments and the constraint that the elastic energy must decrease with time at fixed stress. The evolution laws lead to singularity formation at finite times, which we expect will be related to the formation of cell walls. Implementation of finite difference simulations using the upwind scheme and the results in one and higher dimensions will be discussed.

  7. Solar cell contact formation using laser ablation

    DOEpatents

    Harley, Gabriel; Smith, David D.; Cousins, Peter John

    2015-07-21

    The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline material layer; and forming conductive contacts in the plurality of contact holes.

  8. Solar cell contact formation using laser ablation

    DOEpatents

    Harley, Gabriel; Smith, David D.; Cousins, Peter John

    2014-07-22

    The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline materiat layer; and forming conductive contacts in the plurality of contact holes.

  9. Solar cell contact formation using laser ablation

    DOEpatents

    Harley, Gabriel; Smith, David; Cousins, Peter

    2012-12-04

    The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline material layer; and forming conductive contacts in the plurality of contact holes.

  10. Orientation of endothelial cell division is regulated by VEGF signaling during blood vessel formation

    PubMed Central

    Zeng, Gefei; Taylor, Sarah M.; McColm, Janet R.; Kappas, Nicholas C.; Kearney, Joseph B.; Williams, Lucy H.; Hartnett, Mary E.; Bautch, Victoria L.

    2007-01-01

    New blood vessel formation requires the coordination of endothelial cell division and the morphogenetic movements of vessel expansion, but it is not known how this integration occurs. Here, we show that endothelial cells regulate division orientation during the earliest stages of blood vessel formation, in response to morphogenetic cues. In embryonic stem (ES) cell–derived vessels that do not experience flow, the plane of endothelial cytokinesis was oriented perpendicular to the vessel long axis. We also demonstrated regulated cleavage orientation in vivo, in flow-exposed forming retinal vessels. Daughter nuclei moved away from the cleavage plane after division, suggesting that regulation of endothelial division orientation effectively extends vessel length in these developing vascular beds. A gain-of-function mutation in VEGF signaling increased randomization of endothelial division orientation, and this effect was rescued by a transgene, indicating that regulation of division orientation is a novel mechanism whereby VEGF signaling affects vessel morphogenesis. Thus, our findings show that endothelial cell division and morphogenesis are integrated in developing vessels by flow-independent mechanisms that involve VEGF signaling, and this cross talk is likely to be critical to proper vessel morphogenesis. PMID:17068148

  11. Contribution of radon and radon daughters to respiratory cancer.

    PubMed Central

    Harley, N; Samet, J M; Cross, F T; Hess, T; Muller, J; Thomas, D

    1986-01-01

    This article reviews studies on the contribution of radon and radon daughters to respiratory cancer and proposes recommendations for further research, particularly a national radon survey. The steady-state outdoor radon concentration averages 200 pCi/m3, and indoor levels are about 4 times higher. The primary source of radon in homes is the underlying soil; entry depends on multiple variables and reduced ventilation for energy conservation increases indoor radon levels. Occupational exposures are expressed in units of radon daughter potential energy concentration or working level (WL). Cumulative exposure is the product of the working level and the time exposed. The unit for cumulative exposure is the working level month (WLM). The occupational standard for radon exposure is 4 WLM/year, and 2 WLM/year has been suggested as a guideline for remedial action in homes. Epidemiologic studies show that miners with cumulative radon daughter exposures somewhat below 100 WLM have excess lung cancer mortality. Some 3% to 8% of miners studied have developed lung cancer attributable to radon daughters. All of the underground mining studies show an increased risk of lung cancer with radon daughter exposure. All cell types of lung cancer increased with radon exposure. If radon and smoking act in a multiplicative manner, then the risk for smokers could be 10 times that for nonsmokers. The potential risk of lung cancer appears to be between 1 and 2 per 10,000/WLM, which yields a significant number of lung cancers as some 220 million persons in the United States are exposed on average to 10 to 20 WLM/lifetime. PMID:3830103

  12. Asymmetric segregation of the tumor suppressor brat regulates self-renewal in Drosophila neural stem cells.

    PubMed

    Betschinger, Joerg; Mechtler, Karl; Knoblich, Juergen A

    2006-03-24

    How stem cells generate both differentiating and self-renewing daughter cells is unclear. Here, we show that Drosophila larval neuroblasts-stem cell-like precursors of the adult brain-regulate proliferation by segregating the growth inhibitor Brat and the transcription factor Prospero into only one daughter cell. Like Prospero, Brat binds and cosegregates with the adaptor protein Miranda. In larval neuroblasts, both Brat and Prospero are required to inhibit self-renewal in one of the two daughter cells. While Prospero regulates cell-cycle gene transcription, Brat acts as a posttranscriptional inhibitor of dMyc. In brat or prospero mutants, both daughter cells grow and behave like neuroblasts leading to the formation of larval brain tumors. Similar defects are seen in lethal giant larvae (lgl) mutants where Brat and Prospero are not asymmetric. We have identified a molecular mechanism that may control self-renewal and prevent tumor formation in other stem cells as well.

  13. Fixed drug eruption to ibuprofen in daughter and father.

    PubMed

    Al Aboud, Khalid; Ramesh, V; Al Hawsawi, Khalid

    2003-12-01

    Fixed drug eruption (FDE) is a common cutaneous reaction which may be seen in reaction to several medications. The usual etiologic agents associated with FDE are phenazones, sulfonamides, and tetracyclines. Often the causative agent is made out from the patients history; in some cases, oral challenge or topical testing may be required. The pathophysiology of FDE is unclear. Cell-mediated, rather than humoral immunity is thought to be involved. Herein we report a case of FDE in a daughter and father.

  14. Pattern formation in cell membrane adhesion

    NASA Astrophysics Data System (ADS)

    Discher, Dennis; Hategan, A.; Sengupta, K.; Sackmann, E.

    2004-03-01

    Strong adhesion of highly active cells often nucleates focal adhesions or related structures that are, over time, reinforced by cytoskeleton (actin, etc.). Red cells lack such complex adhesion systems, but they are shown here to also exhibit complex spatial patterns within an adhesive contact zone. While strong adhesion and spreading of the red cell to a dense poly-L-lysine surface appears complete in < 1 s by reflective interference microscopy, over longer times of 10-15 min or more distinct patterns in fluorescently labeled membrane components emerge. The fluorescent lipid Fl-PE (fluorescein phosphoethanolamine), in particular, is seen to diffuse and reorganize (eg. worm-like domains of <500 nm) within the contact zone, independent of whether the cell is intact or ruptured. Lipid patterns are accompanied by visible perturbations in band 3 distribution and weaker perturbations in membrane skeleton actin. Although fluorescent poly-L-lysine is shown to be uniform under cells, pressing down on the membrane quenches the lipid patterns and reveals the topographical basis for pattern formation. Regions of strong contact are thus separated by regions where the membrane is more distant from the surface.

  15. User's manual for the DAD-1 data acquisition daughter board for the SuperCard-2

    SciTech Connect

    Ferron, J.R.

    1993-05-01

    A detailed description of how to use the DAD-1 data acquisition daughter board is given. The DAD-1 daughter board is used with the SuperCard-2, a VME format processor board manufactured by CSP Inc. that is based on the Intel i860 microprocessor. The daughter board provides high speed acquisition of digital data through a general purpose input port. Data are transferred through direct memory access operations to the memory on the SuperCard-2 board at a rate up to 40 million, 14 bit samples per second. A first-in, first-out memory is used to buffer the data during the transfer. Several different data acquisition operating modes are available that make a combination of a SuperCard-2 processor board and a DAD-1 daughter board suitable for a wide range of real time data analysis and feedback control functions.

  16. Glucocorticoid resistance of migration and gene expression in a daughter MDA-MB-231 breast tumour cell line selected for high metastatic potential

    PubMed Central

    Fietz, Ebony R.; Keenan, Christine R.; López-Campos, Guillermo; Tu, Yan; Johnstone, Cameron N.; Harris, Trudi; Stewart, Alastair G.

    2017-01-01

    Glucocorticoids are commonly used to prevent chemotherapy-induced nausea and vomiting despite a lack of understanding of their direct effect on cancer progression. Recent studies suggest that glucocorticoids inhibit cancer cell migration. However, this action has not been investigated in estrogen receptor (ER)-negative breast tumour cells, although activation of the glucocorticoid receptor (GR) is associated with a worse prognosis in ER-negative breast cancers. In this study we have explored the effect of glucocorticoids on the migration of the ER-negative MDA-MB-231 human breast tumour cell line and the highly metastatic MDA-MB-231-HM.LNm5 cell line that was generated through in vivo cycling. We show for the first time that glucocorticoids inhibit 2- and 3-dimensional migration of MDA-MB-231 cells. Selection of cells for high metastatic potential resulted in a less migratory cell phenotype that was resistant to regulation by glucocorticoids and showed decreased GR receptor expression. The emergence of glucocorticoid resistance during metastatic selection may partly explain the apparent disparity between the clinical and in vitro evidence regarding the actions of glucocorticoids in cancer. These findings highlight the highly plastic nature of tumour cells, and underscore the need to more fully understand the direct effect of glucocorticoid treatment on different stages of metastatic progression. PMID:28262792

  17. Plk1 relieves centriole block to reduplication by promoting daughter centriole maturation.

    PubMed

    Shukla, Anil; Kong, Dong; Sharma, Meena; Magidson, Valentin; Loncarek, Jadranka

    2015-08-21

    Centrosome overduplication promotes mitotic abnormalities, invasion and tumorigenesis. Cells regulate the number of centrosomes by limiting centriole duplication to once per cell cycle. The orthogonal orientation between a mother and a daughter centriole, established at the time of centriole duplication, is thought to block further duplication of the mother centriole. Loss of orthogonal orientation (disengagement) between two centrioles during anaphase is considered a licensing event for the next round of centriole duplication. Disengagement requires the activity of Polo-like kinase 1 (Plk1), but how Plk1 drives this process is not clear. Here we employ correlative live/electron microscopy and demonstrate that Plk1 induces maturation and distancing of the daughter centriole, allowing reduplication of the mother centriole even if the original daughter centriole is still orthogonal to it. We find that mother centrioles can undergo reduplication when original daughter centrioles are only ∼80 nm apart, which is the distance centrioles normally reach during prophase.

  18. Novel solar cells in a wire format.

    PubMed

    Chen, Tao; Qiu, Longbin; Yang, Zhibin; Peng, Huisheng

    2013-06-21

    Photovoltaic devices in a wire format have recently attracted increasing attention as, compared with the conventional planar structure, they show unique and promising advantages. For instance, they are light-weight and can be easily woven into clothes or integrated into other structures, which enable applications in electronic textiles and various complex devices. In this tutorial review, the recent advancement in photovoltaic wires including both dye-sensitized and polymer solar cells are described. Two main architectures based on a single core-sheath fiber and twisted fibers are carefully illustrated with an emphasis on the comparison of various substrates which have been focused in past development. The current challenge including low energy conversion efficiency and low stability and future direction of the wire-shaped cell have been finally summarized.

  19. Radionuclide daughter inventory generator code: DIG

    SciTech Connect

    Fields, D.E.; Sharp, R.D.

    1985-09-01

    The Daughter Inventory Generator (DIG) code accepts a tabulation of radionuclide initially present in a waste stream, specified as amounts present either by mass or by activity, and produces a tabulation of radionuclides present after a user-specified elapsed time. This resultant radionuclide inventory characterizes wastes that have undergone daughter ingrowth during subsequent processes, such as leaching and transport, and includes daughter radionuclides that should be considered in these subsequent processes or for inclusion in a pollutant source term. Output of the DIG code also summarizes radionuclide decay constants. The DIG code was developed specifically to assist the user of the PRESTO-II methodology and code in preparing data sets and accounting for possible daughter ingrowth in wastes buried in shallow-land disposal areas. The DIG code is also useful in preparing data sets for the PRESTO-EPA code. Daughter ingrowth in buried radionuclides and in radionuclides that have been leached from the wastes and are undergoing hydrologic transport are considered, and the quantities of daughter radionuclide are calculated. Radionuclide decay constants generated by DIG and included in the DIG output are required in the PRESTO-II code input data set. The DIG accesses some subroutines written for use with the CRRIS system and accesses files containing radionuclide data compiled by D.C. Kocher. 11 refs.

  20. Mother-daughter communication about HPV vaccine.

    PubMed

    McRee, Annie-Laurie; Reiter, Paul L; Gottlieb, Sami L; Brewer, Noel T

    2011-03-01

    Parent-child conversations about human papillomavirus (HPV) vaccine may provide parents with the opportunity to talk with their daughters about sexual health. We sought to characterize mothers' communication with their adolescent daughters about HPV vaccine. We surveyed 609 mothers of girls aged between 11 and 20 years living in North Carolina in Fall 2008. We used logistic regression to identify the correlates of mother-daughter communication. Most mothers (81%) reported having discussed HPV vaccine with their daughters. For almost half of these families (47%), discussion of HPV vaccine led to a conversation about sex. This was more common among mothers who believed that their daughters may be sexually active (odds ratio [OR]: 1.88; 95% confidence interval [CI]: 1.25-2.83), had greater knowledge of HPV vaccine (OR: 2.46; 95% CI: 1.07-5.64), lived in urban areas (OR: 1.75; 95% CI: 1.21-2.54), or reported being born-again Christians (OR: 1.74; 95% CI: 1.17-2.58). Most mothers who talked with their daughters about HPV vaccine reported having discussed the reasons for and against getting vaccinated (86%). Mothers most commonly reported having discussed the potential HPV vaccine benefits, usually protection against cervical cancer (56%), and less frequently reported having discussed the perceived disadvantages of HPV vaccine. HPV vaccine conversations may provide opportunities for sexual health promotion and sexually transmitted infection (STI) prevention. Copyright © 2011 Society for Adolescent Health and Medicine. All rights reserved.

  1. Mother-daughter communication about HPV vaccine

    PubMed Central

    McRee, Annie-Laurie; Reiter, Paul L.; Gottlieb, Sami L.; Brewer, Noel T.

    2011-01-01

    Purpose Parent-child conversations about HPV vaccine may provide parents with opportunities to talk with their daughters about sexual health. We sought to characterize mothers’ communication with their adolescent daughters about HPV vaccine. Methods We surveyed 609 mothers of girls aged 11–20 living in North Carolina in fall 2008. We used logistic regression to identify correlates of mother-daughter communication. Results Most mothers (81%) reported discussing HPV vaccine with their daughters. For almost half of these families (47%), discussing HPV vaccine led to a conversation about sex. This was more common among mothers who believed their daughters may be sexually active (OR: 1.88, 95%CI: 1.25–2.83), had greater knowledge of HPV vaccine (OR: 2.46, 95%CI: 1.07–5.64), lived in urban areas (OR: 1.75, 95%CI: 1.21–2.54), or reported being born-again Christians (OR: 1.74, 95%CI: 1.17–2.58). Most mothers who talked with their daughters about HPV vaccine reported discussing reasons for and against getting vaccinated (86%). Mothers most commonly reported discussing potential HPV vaccine benefits, usually protection against cervical cancer (56%), and less frequently reported discussing perceived negatives of HPV vaccine. Conclusions HPV vaccine conversations may provide opportunities for sexual health promotion and STI prevention. PMID:21338906

  2. Organic Tandem Solar Cells: Design and Formation

    NASA Astrophysics Data System (ADS)

    Chen, Chun-Chao

    polyelectrolyte layer functioning as the surface dipole formation layer to provide better electrical contact with the photoactive layer. Due to the effectiveness of the conjugated polyelectrolyte layer, performance improvement was also observed. Furthermore, other issues regarding the semi-transparent tandem solar cells (e.g., photocurrent matching, exterior color tuning, and transparency tuning) are all explored to optimize best performance. In Chapter 5 and 6, the architectures of double- and triple-junction tandem solar cells are explored. Theoretically, triple-junction tandem solar cells with three photoactive absorbers with cascaded energy bandgaps have the potential to achieve higher performance, in comparison with double-junction tandem solar cells. Such expectations can be ascribed to the minimized carrier thermalization loss and further improved light absorption. However, the design of triple-junction solar cells often involves sophisticated multiple layer deposition as well as substantial optimization. Therefore, there is a lack of successful demonstrations of triple-junction solar cells outperforming the double-junction counterparts. To solve the incompatible issues related to the layer deposition in the fabrication, we proposed a novel architecture of inverted-structure tandem solar cells with newly designed interconnecting layers. Our design of interconnecting layers does not only focus on maintaining the orthogonal solution processing advantages, but also provides an excellent compatibility in the energy level alignment to allow different absorber materials to be used. Furthermore, we also explored the light management inside the double- and triple-junction tandem solar cells. The study of light management was carried out through optical simulation method based transfer matrix formalism. The intention is to obtain a balanced photocurrent output from each subcells inside the tandem solar cell, thus the minimal recombination loss at the contact of interconnecting

  3. Neural Stem Cells in Drosophila: Molecular Genetic Mechanisms Underlying Normal Neural Proliferation and Abnormal Brain Tumor Formation

    PubMed Central

    Saini, Nidhi; Reichert, Heinrich

    2012-01-01

    Neural stem cells in Drosophila are currently one of the best model systems for understanding stem cell biology during normal development and during abnormal development of stem cell-derived brain tumors. In Drosophila brain development, the proliferative activity of neural stem cells called neuroblasts gives rise to both the optic lobe and the central brain ganglia, and asymmetric cell divisions are key features of this proliferation. The molecular mechanisms that underlie the asymmetric cell divisions by which these neuroblasts self-renew and generate lineages of differentiating progeny have been studied extensively and involve two major protein complexes, the apical complex which maintains polarity and controls spindle orientation and the basal complex which is comprised of cell fate determinants and their adaptors that are segregated into the differentiating daughter cells during mitosis. Recent molecular genetic work has established Drosophila neuroblasts as a model for neural stem cell-derived tumors in which perturbation of key molecular mechanisms that control neuroblast proliferation and the asymmetric segregation of cell fate determinants lead to brain tumor formation. Identification of novel candidate genes that control neuroblast self-renewal and differentiation as well as functional analysis of these genes in normal and tumorigenic conditions in a tissue-specific manner is now possible through genome-wide transgenic RNAi screens. These cellular and molecular findings in Drosophila are likely to provide valuable genetic links for analyzing mammalian neural stem cells and tumor biology. PMID:22737173

  4. My Daughter the Scientist? Mothers' Perceptions of the Shift in Their Daughter's Personal Science Identities

    ERIC Educational Resources Information Center

    Farland-Smith, Donna

    2016-01-01

    This study reports on the perspective of mothers whose daughters underwent an extensive inquiry-focused interactive one-week science camp, which involved female middle school students and university scientists. This study focused on nine mother's perceptions of the impact the camp had on their daughter's science identities. Following the camp,…

  5. Contact formation in gallium arsenide solar cells

    NASA Technical Reports Server (NTRS)

    Weizer, Victor G.; Fatemi, Navid S.

    1988-01-01

    Gold and gold-based alloys, commonly used as solar cell contact materials, are known to react readily with gallium arsenide. Experiments were performed to identify the mechanisms involved in these GaAs-metal interactions. It is shown that the reaction of GaAs with gold takes place via a dissociative diffusion process. It is shown further that the GaAs-metal reaction rate is controlled to a very great extent by the condition of the free surface of the contact metal, an interesting example of which is the previously unexplained increase in the reaction rate that has been observed for samples annealed in a vacuum environment as compared to those annealed in a gaseous ambient. A number of other hard-to-explain observations, such as the low-temperature formation of voids in the gold lattice and crystallite growth on the gold surface, are explained by invoking this mechanism.

  6. Sons and daughters in China.

    PubMed

    Robey, B

    1985-11-01

    Demographers from the East-West Population Institute (EWPI) and the China State Family Planning Commission, jointly analyzing data from computer tapes of China's 1982 national fertility survey, have produced new evidence of the extent to which families in China prefer male children. Evidence exists in almost every part of China that couples prefer sons to daughters, according to researchers Fred Arnold and Liu Zhaoxiang. Only Beijing and Shanghai are exceptions to this pattern. The persistence of such attidues in China demonstrates the difficulty of overcoming deeply rooted Confucian traditions. Following the Chinese revolution, the government guaranteed sexual equality in political, economic, and cultural life, but patriarchal attitudes still prevail, particularly in the countryside. Historically, couples have favored sons for a variety of reasons, including to continue the family name, provide security for the parents' old age, add to the family labor force, and perform ancestral rites. Believing that such attitudes block successful implementation of China's 1-child family policy, the government has launched a campaign to try to change them. At the time of the time of the 1982 fertility survey, China's 1-child certificate program had been in effect for 3 years. The program provides incentives such as monetary bonuses, preferential housing allocation, and special consideration for the child in education and job assignments to couples who agree not to have a 2nd child. According to the survey, 37% of all 1-child couples had accepted the 1-child certificate. Significantly, 60% of all 1-child certificate holders have a son. Of couples whose 1st child was a boy, 40% obtained the 1-child certificate, versus only 34% of those whose 1st child was a girl. Despite penalties for renouncing the 1-child certificate, about 1 out of every 10 mothers in the program had given birth to a 2nd child by the time of the survey. The 1st child of these mothers was twice as likely to be

  7. Role of the N-Acetylmuramoyl-l-Alanyl Amidase, AmiA, of Helicobacter pylori in Peptidoglycan Metabolism, Daughter Cell Separation, and Virulence.

    PubMed

    Chaput, Catherine; Ecobichon, Chantal; Pouradier, Nadine; Rousselle, Jean-Claude; Namane, Abdelkader; Boneca, Ivo G

    2016-09-01

    The human gastric pathogen, Helicobacter pylori, is becoming increasingly resistant to most available antibiotics. Peptidoglycan (PG) metabolism is essential to eubacteria, hence, an excellent target for the development of new therapeutic strategies. However, our knowledge on PG metabolism in H. pylori remains poor. We have further characterized an isogenic mutant of the amiA gene encoding a N-acetylmuramoyl-l-alanyl amidase. The amiA mutant displayed long chains of unseparated cells, an impaired motility despite the presence of intact flagella and a tolerance to amoxicillin. Interestingly, the amiA mutant was impaired in colonizing the mouse stomach suggesting that AmiA is a valid target in H. pylori for the development of new antibiotics. Using reverse phase high-pressure liquid chromatography, we analyzed the PG muropeptide composition and glycan chain length distribution of strain 26695 and its amiA mutant. The analysis showed that H. pylori lacked muropeptides with a degree of cross-linking higher than dimeric muropeptides. The amiA mutant was also characterized by a decrease of muropeptides carrying 1,6-anhydro-N-acetylmuramic acid residues, which represent the ends of the glycan chains. This correlated with an increase of very long glycan strands in the amiA mutant. It is suggested that these longer glycan strands are trademarks of the division site. Taken together, we show that the low redundancy on genes involved in PG maturation supports H. pylori as an actractive alternative model to study PG metabolism and cell shape regulation.

  8. Role of the N-Acetylmuramoyl-l-Alanyl Amidase, AmiA, of Helicobacter pylori in Peptidoglycan Metabolism, Daughter Cell Separation, and Virulence

    PubMed Central

    Chaput, Catherine; Ecobichon, Chantal; Pouradier, Nadine; Rousselle, Jean-Claude; Namane, Abdelkader

    2016-01-01

    The human gastric pathogen, Helicobacter pylori, is becoming increasingly resistant to most available antibiotics. Peptidoglycan (PG) metabolism is essential to eubacteria, hence, an excellent target for the development of new therapeutic strategies. However, our knowledge on PG metabolism in H. pylori remains poor. We have further characterized an isogenic mutant of the amiA gene encoding a N-acetylmuramoyl-l-alanyl amidase. The amiA mutant displayed long chains of unseparated cells, an impaired motility despite the presence of intact flagella and a tolerance to amoxicillin. Interestingly, the amiA mutant was impaired in colonizing the mouse stomach suggesting that AmiA is a valid target in H. pylori for the development of new antibiotics. Using reverse phase high-pressure liquid chromatography, we analyzed the PG muropeptide composition and glycan chain length distribution of strain 26695 and its amiA mutant. The analysis showed that H. pylori lacked muropeptides with a degree of cross-linking higher than dimeric muropeptides. The amiA mutant was also characterized by a decrease of muropeptides carrying 1,6-anhydro-N-acetylmuramic acid residues, which represent the ends of the glycan chains. This correlated with an increase of very long glycan strands in the amiA mutant. It is suggested that these longer glycan strands are trademarks of the division site. Taken together, we show that the low redundancy on genes involved in PG maturation supports H. pylori as an actractive alternative model to study PG metabolism and cell shape regulation. PMID:27447281

  9. Daughters mimic sterile neutrinos (almost!) perfectly

    NASA Astrophysics Data System (ADS)

    Hasenkamp, Jasper

    2014-09-01

    Since only recently, cosmological observations are sensitive to hot dark matter (HDM) admixtures with sub-eV mass, mhdmeff < eV, that are not fully-thermalised, Δ Neff < 1. We argue that their almost automatic interpretation as a sterile neutrino species is neither from theoretical nor practical parsimony principles preferred over HDM formed by decay products (daughters) of an out-of-equilibrium particle decay. While daughters mimic sterile neutrinos in Neff and mhdmeff, there are opportunities to assess this possibility in likelihood analyses. Connecting cosmological parameters and moments of momentum distribution functions, we show that—also in the case of mass-degenerate daughters with indistinguishable main physical effects—the mimicry breaks down when the next moment, the skewness, is considered. Predicted differences of order one in the root-mean-squares of absolute momenta are too small for current sensitivities.

  10. Radon and its daughters in vivo

    SciTech Connect

    Rundo, J.

    1983-01-01

    Some aspects of the behavior of radon and its short-lived daughters in vivo are described and a relationship between the radon exhalation rate and time after a meal is demonstrated. A major but short-lived postprandial increase in the exhalation rate of radon produced from skeletally-deposited radium was observed and a similar effect in exhalation rate of environmental radon by persons containing no radium was noted. Persons living in houses with elevated concentrations of radon may contain sufficient activity for its detection by external gamma-ray counting. Some of the activity observed is due to inhaled daughter-products in the chest, and some to daughter-products associated with and produced by the decay of radon throughout the body. 3 references, 8 figures. (MF)

  11. Sample chambers with mother-daughter mode

    SciTech Connect

    Wilk, P.A.; Gregorich, K.E.; Hoffman, D.C.

    2001-07-12

    A set of eight stand-alone sample chambers with a common interface were constructed at LBNL for improved detection of alpha and fission decay chains over currently used designs. The stainless steel chambers (see Figure 1 for a schematic and Figure 2 for a photograph of a completed chamber) were constructed to allow for low background detection of a daughter event by removal of the sample following the detection of a parent event. This mother-daughter mode of operation has been utilized successfully with our Merry-go-Round (MG) detection system [Gregorich 1994].

  12. Zoonotic Anatrichosomiasis in a Mother and Daughter

    PubMed Central

    Hellstein, John W.; Lanzel, Emily A.

    2014-01-01

    Zoonotic anatrichosomiasis in a mother and daughter is reported. Both presented with a 10-week history of multiple painful oral ulcers. Biopsy specimens revealed the presence of small, coiled trichuroid nematodes with distinctive morphological features, including stichocytes and paired bacillary bands. This represents an unusual infection by a zoonotic Anatrichosoma species. PMID:24899034

  13. Melancholic Mothering: Mothers, Daughters and Family Violence

    ERIC Educational Resources Information Center

    Kenway, Jane; Fahey, Johannah

    2008-01-01

    Through selected theories of melancholia, this paper seeks to shed some fresh interpretive light on the reproduction and disruption of gender, violence and family turmoil across generations of mothers and daughters. The originality of the paper lies in its exploratory deployment of theories of melancholia to consider issues of women, violence and…

  14. Humanistic Treatment of Father-Daughter Incest.

    ERIC Educational Resources Information Center

    Giarretto, Henry

    1978-01-01

    Following a case study of father-daughter incest, the author comments on the prevalence of incest and describes Santa Clara County's Child Sexual Abuse Treatment Program (CSATP). The founding of CSATP, its treatment model for incestuous families, and its preliminary results are covered. (SJL)

  15. White piedra in a mother and daughter.

    PubMed

    Roshan, Anupama S; Janaki, C; Parveen, B

    2009-07-01

    White Piedra is a superficial fungal infection of the hair caused by Trichosporon asahii. It is also known as trichomycosis nodosa or trichomycosis nodularis. We report two cases of White Piedra in a mother and her daughter for the rarity of such occurrence.

  16. Melancholic Mothering: Mothers, Daughters and Family Violence

    ERIC Educational Resources Information Center

    Kenway, Jane; Fahey, Johannah

    2008-01-01

    Through selected theories of melancholia, this paper seeks to shed some fresh interpretive light on the reproduction and disruption of gender, violence and family turmoil across generations of mothers and daughters. The originality of the paper lies in its exploratory deployment of theories of melancholia to consider issues of women, violence and…

  17. Catholic Girls: The Mother-Daughter Nexus

    ERIC Educational Resources Information Center

    Keary, Anne

    2011-01-01

    This paper examines Catholic girlhood, womanhood and the mother-daughter relationship, and its socio-historical construction within a range of disparate discourses. The aim of the paper is to deconstruct dominant patriarchal constructions and images of femininity, particularly those embedded within the doctrine of Catholicism. Moreover, the paper…

  18. Catholic Girls: The Mother-Daughter Nexus

    ERIC Educational Resources Information Center

    Keary, Anne

    2011-01-01

    This paper examines Catholic girlhood, womanhood and the mother-daughter relationship, and its socio-historical construction within a range of disparate discourses. The aim of the paper is to deconstruct dominant patriarchal constructions and images of femininity, particularly those embedded within the doctrine of Catholicism. Moreover, the paper…

  19. Horizons: A Mother-Daughter Mathematics Club.

    ERIC Educational Resources Information Center

    Boling, Kimberly B.; Larson, Carol Novillis

    2002-01-01

    Describes a successful mother/daughter math club started by a third grade teacher which is designed to help participants increase positive feelings about mathematics; further develop problem-solving skills, especially involving construction and spatial visualization tasks; and become familiar with women's contributions to the world of mathematics.…

  20. Enabling cell-cell communication via nanopore formation: structure, function and localization of the unique cell wall amidase AmiC2 of Nostoc punctiforme.

    PubMed

    Büttner, Felix M; Faulhaber, Katharina; Forchhammer, Karl; Maldener, Iris; Stehle, Thilo

    2016-04-01

    To orchestrate a complex life style in changing environments, the filamentous cyanobacterium Nostoc punctiforme facilitates communication between neighboring cells through septal junction complexes. This is achieved by nanopores that perforate the peptidoglycan (PGN) layer and traverse the cell septa. The N-acetylmuramoyl-l-alanine amidase AmiC2 (Npun_F1846; EC 3.5.1.28) in N. punctiforme generates arrays of such nanopores in the septal PGN, in contrast to homologous amidases that mediate daughter cell separation after cell division in unicellular bacteria. Nanopore formation is therefore a novel property of AmiC homologs. Immunofluorescence shows that native AmiC2 localizes to the maturing septum. The high-resolution crystal structure (1.12 Å) of its catalytic domain (AmiC2-cat) differs significantly from known structures of cell splitting and PGN recycling amidases. A wide and shallow binding cavity allows easy access of the substrate to the active site, which harbors an essential zinc ion. AmiC2-cat exhibits strong hydrolytic activity in vitro. A single point mutation of a conserved glutamate near the zinc ion results in total loss of activity, whereas zinc removal leads to instability of AmiC2-cat. An inhibitory α-helix, as found in the Escherichia coli AmiC(E. coli) structure, is absent. Taken together, our data provide insight into the cell-biological, biochemical and structural properties of an unusual cell wall lytic enzyme that generates nanopores for cell-cell communication in multicellular cyanobacteria. The novel structural features of the catalytic domain and the unique biological function of AmiC2 hint at mechanisms of action and regulation that are distinct from other amidases. The AmiC2-cat structure has been deposited in the Protein Data Bank under accession number 5EMI. © 2016 Federation of European Biochemical Societies.

  1. Enhanced retention of the alpha-particle-emitting daughters of Actinium-225 by liposome carriers.

    PubMed

    Sofou, Stavroula; Kappel, Barry J; Jaggi, Jaspreet S; McDevitt, Michael R; Scheinberg, David A; Sgouros, George

    2007-01-01

    Targeted alpha-particle emitters hold great promise as therapeutics for micrometastatic disease. Because of their high energy deposition and short range, tumor targeted alpha-particles can result in high cancer-cell killing with minimal normal-tissue irradiation. Actinium-225 is a potential generator for alpha-particle therapy: it decays with a 10-day half-life and generates three alpha-particle-emitting daughters. Retention of (225)Ac daughters at the target increases efficacy; escape and distribution throughout the body increases toxicity. During circulation, molecular carriers conjugated to (225)Ac cannot retain any of the daughters. We previously proposed liposomal encapsulation of (225)Ac to retain the daughters, whose retention was shown to be liposome-size dependent. However, daughter retention was lower than expected: 22% of theoretical maximum decreasing to 14%, partially due to the binding of (225)Ac to the phospholipid membrane. In this study, Multivesicular liposomes (MUVELs) composed of different phospholipids were developed to increase daughter retention. MUVELs are large liposomes with entrapped smaller lipid-vesicles containing (225)Ac. PEGylated MUVELs stably retained over time 98% of encapsulated (225)Ac. Retention of (213)Bi, the last daughter, was 31% of the theoretical maximum retention of (213)Bi for the liposome sizes studied. MUVELs were conjugated to an anti-HER2/neu antibody (immunolabeled MUVELs) and were evaluated in vitro with SKOV3-NMP2 ovarian cancer cells, exhibiting significant cellular internalization (83%). This work demonstrates that immunolabeled MUVELs might be able to deliver higher fractions of generated alpha-particles per targeted (225)Ac compared to the relative fractions of alpha-particles delivered by (225)Ac-labeled molecular carriers.

  2. Enhanced Retention of the α-particle Emitting Daughters of Actinium-225 by Liposome Carriers

    PubMed Central

    Stavroula, Sofou; Kappel, Barry J.; Jaggi, Jaspreet S.; McDevitt, Michael R.; Scheinberg, David A.; Sgouros, George

    2008-01-01

    Targeted α-particle emitters hold great promise as therapeutics for micrometastatic disease. Because of their high energy deposition and short range, tumor targeted α-particles can result in high cancer-cell killing with minimal normal-tissue irradiation. Actinium-225 is a potential generator for α-particle therapy: it decays with a 10-day half-life and generates three α-particle emitting daughters. Retention of 225Ac daughters at the target increases efficacy; escape and distribution throughout the body increases toxicity. During circulation, molecular carriers conjugated to 225Ac cannot retain any of the daughters. We previously proposed liposomal encapsulation of 225Ac to retain the daughters, whose retention was shown to be liposome-size dependent. However, daughter retention was lower than expected: 22% of theoretical maximum decreasing to 14%, partially due to binding of 225Ac to the phospholipid membrane. In this study, MUltiVEsicular Liposomes (MUVELs) composed of different phospholipids were developed to increase daughter retention. MUVELs are large liposomes with entrapped smaller lipid-vesicles containing 225Ac. PEGylated MUVELs stably retained over time 98% of encapsulated 225Ac. Retention of 213Bi, the last daughter, was 31% of the theoretical maximum retention of 213Bi for the liposome sizes studied. MUVELs were conjugated to an anti-HER2/neu antibody (immunolabeled MUVELs), and were evaluated in vitro with SKOV3-NMP2 ovarian cancer cells, exhibiting significant cellular internalization (83%). This work demonstrates that immunolabeled MUVELs could be able to deliver higher fractions of generated α-particles per targeted 225Ac compared to the relative fractions of α-particles delivered by 225Ac-labeled molecular carriers. PMID:17935286

  3. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Radon daughter exposure monitoring. 57.5037... Radon daughter exposure monitoring. (a) In all mines at least one sample shall be taken in exhaust mine air by a competent person to determine if concentrations of radon daughters are present. Sampling...

  4. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Radon daughter exposure monitoring. 57.5037... Radon daughter exposure monitoring. (a) In all mines at least one sample shall be taken in exhaust mine air by a competent person to determine if concentrations of radon daughters are present. Sampling...

  5. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Radon daughter exposure monitoring. 57.5037... Radon daughter exposure monitoring. (a) In all mines at least one sample shall be taken in exhaust mine air by a competent person to determine if concentrations of radon daughters are present. Sampling...

  6. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Radon daughter exposure monitoring. 57.5037... Radon daughter exposure monitoring. (a) In all mines at least one sample shall be taken in exhaust mine air by a competent person to determine if concentrations of radon daughters are present. Sampling...

  7. 30 CFR 57.5037 - Radon daughter exposure monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Radon daughter exposure monitoring. 57.5037... Radon daughter exposure monitoring. (a) In all mines at least one sample shall be taken in exhaust mine air by a competent person to determine if concentrations of radon daughters are present. Sampling...

  8. Gifted Women Scientists: Voices of Mothers and Daughters.

    ERIC Educational Resources Information Center

    Handel, Ruth D.

    1994-01-01

    This paper explores intergenerational socialization into science through case studies of eight research biologists who are mothers of daughters. The study examined ways in which mothers foster or fail to foster orientation to science fields, daughters' perspectives on science professions, influential factors, and the daughters' pride in their…

  9. Formation of multilayer aggregates of mammalian cells by dielectrophoresis

    NASA Astrophysics Data System (ADS)

    Sebastian, Anil; Buckle, Anne-Marie; Markx, Gerard H.

    2006-09-01

    The formation of aggregates of mammalian cells at interdigitated oppositely castellated electrodes by positive dielectrophoresis was investigated. It is shown that, by using a constant small flow of fresh sorbitol iso-osmotic buffer through the chamber to remove ions leaking from the cells, a high positive DEP force can be maintained throughout the formation of the aggregates. Flow-rate dependent optima were found in the aggregate height as a function of the electrode size. It is shown that at low flow rates the creation of aggregates of mammalian cells with heights over 150 µm is feasible using relatively low voltages (20 Vpk-pk, 1 MHz). The formation of layered aggregates of two specialized cell types—stromal cells and Jurkat T lymphocytes—is demonstrated. The work confirms that dielectrophoresis can be reliably used for the formation of aggregates with three-dimensional architectures, which could be used as artificial microniches for the study of interactions between cells.

  10. Formation and cultivation of medaka primordial germ cells.

    PubMed

    Li, Zhendong; Li, Mingyou; Hong, Ni; Yi, Meisheng; Hong, Yunhan

    2014-07-01

    Primordial germ cell (PGC) formation is pivotal for fertility. Mammalian PGCs are epigenetically induced without the need for maternal factors and can also be derived in culture from pluripotent stem cells. In egg-laying animals such as Drosophila and zebrafish, PGCs are specified by maternal germ plasm factors without the need for inducing factors. In these organisms, PGC formation and cultivation in vitro from indeterminate embryonic cells have not been possible. Here, we report PGC formation and cultivation in vitro from blastomeres dissociated from midblastula embryos (MBEs) of the fish medaka (Oryzias latipes). PGCs were identified by using germ-cell-specific green fluorescent protein (GFP) expression from a transgene under the control of the vasa promoter. Embryo perturbation was exploited to study PGC formation in vivo, and dissociated MBE cells were cultivated under various conditions to study PGC formation in vitro. Perturbation of somatic development did not prevent PGC formation in live embryos. Dissociated MBE blastomeres formed PGCs in the absence of normal somatic structures and of known inducing factors. Most importantly, under culture conditions conducive to stem cell derivation, some dissociated MBE blastomeres produced GFP-positive PGC-like cells. These GFP-positive cells contained genuine PGCs, as they expressed PGC markers and migrated into the embryonic gonad to generate germline chimeras. Our data thus provide evidence for PGC preformation in medaka and demonstrate, for the first time, that PGC formation and derivation can be obtained in culture from early embryos of medaka as a lower vertebrate model.

  11. [The study of daughter rediae Echinostoma caproni (Trematoda) in vitro cultivation].

    PubMed

    Ataev, G L

    2014-01-01

    Methods of in vitro cultivation were used to examine the feeding and reproductive behaviors of daughter rediae of Echinostoma caproni. It was noted that under conditions of in vitro cultivation, rediae fed on tissues of the mollusc Biomphalaria glabrata, on rediae and cercariae of E. daikenaensis and E. congoensis, and on sporocysts and cercariae of Schistosoma mansoni. No cases of cannibalism of daughter rediae E. caproni by their offspring rediae were observed, although they could feed on their own cercariae. When kept in mediae containing (B. glabrata embryonic) Bge cells, rediae E. caproni gradually turned to feeding on these cells and stayed away other objects. Under conditions of in vitro cultivation, daughter rediae E. caproni were capable of forming redial and cercarial embryos. However, no cases of return from producing of cercariae to producing of rediae were observed. These in vitro data confirm the results of previous studies of this species's parthenithae performed in vivo (ATaeB and dp., 2007).

  12. Closure of supporting cell scar formations requires dynamic actin mechanisms.

    PubMed

    Hordichok, Andrew J; Steyger, Peter S

    2007-10-01

    In many vertebrate inner ear sensory epithelia, dying sensory hair cells are extruded, and the apices of surrounding supporting cells converge to re-seal the epithelial barrier between the electrochemically-distinct endolymph and perilymph. These cellular mechanisms remain poorly understood. Dynamic microtubular mechanisms have been proposed for hair cell extrusion; while contractile actomyosin-based mechanisms are required for cellular extrusion and closure in epithelial monolayers. The hypothesis that cytoskeletal mechanisms are required for hair cell extrusion and supporting cell scar formation was tested using bullfrog saccules incubated with gentamicin (6h), and allowed to recover (18h). Explants were then fixed, labeled for actin and cytokeratins, and viewed with confocal microscopy. To block dynamic cytoskeletal processes, disruption agents for microtubules (colchicine, paclitaxel) myosin (Y-27632, ML-9) or actin (cytochalasin D, latrunculin A) were added during treatment and recovery. Microtubule disruption agents had no effect on hair cell extrusion or supporting cell scar formation. Myosin disruption agents appeared to slow down scar formation but not hair cell extrusion. Actin disruption agents blocked scar formation, and largely prevented hair cell extrusion. These data suggest that actin-based cytoskeletal processes are required for hair cell extrusion and supporting cell scar formation in bullfrog saccules.

  13. Closure of supporting cell scar formations requires dynamic actin mechanisms

    PubMed Central

    Hordichok, Andrew J.; Steyger, Peter S.

    2007-01-01

    In many vertebrate inner ear sensory epithelia, dying sensory hair cells are extruded, and the apices of surrounding supporting cells converge to re-seal the epithelial barrier between the electrochemically-distinct endolymph and perilymph. These cellular mechanisms remain poorly understood. Dynamic microtubular mechanisms have been proposed for hair cell extrusion; while contractile actomyosin-based mechanisms are required for cellular extrusion and closure in epithelial monolayers. The hypothesis that cytoskeletal mechanisms are required for hair cell extrusion and supporting cell scar formation was tested using bullfrog saccules incubated with gentamicin (6 hours), and allowed to recover (18 hours). Explants were then fixed, labeled for actin and cytokeratins, and viewed with confocal microscopy. To block dynamic cytoskeletal processes, disruption agents for microtubules (colchicine, paclitaxel) myosin (Y-27632, ML-9) or actin (cytochalasin D, latrunculin A) were added during treatment and recovery. Microtubule disruption agents had no effect on hair cell extrusion or supporting cell scar formation. Myosin disruption agents appeared to slow down scar formation but not hair cell extrusion. Actin disruption agents blocked scar formation, and largely prevented hair cell extrusion. These data suggest that actin-based cytoskeletal processes are required for hair cell extrusion and supporting cell scar formation in bullfrog saccules. PMID:17716843

  14. Daughters mimic sterile neutrinos (almost!) perfectly

    SciTech Connect

    Hasenkamp, Jasper

    2014-09-01

    Since only recently, cosmological observations are sensitive to hot dark matter (HDM) admixtures with sub-eV mass, m{sub hdm}{sup eff} < eV, that are not fully-thermalised, Δ N{sub eff} < 1. We argue that their almost automatic interpretation as a sterile neutrino species is neither from theoretical nor practical parsimony principles preferred over HDM formed by decay products (daughters) of an out-of-equilibrium particle decay. While daughters mimic sterile neutrinos in N{sub eff} and m{sub hdm}{sup eff}, there are opportunities to assess this possibility in likelihood analyses. Connecting cosmological parameters and moments of momentum distribution functions, we show that—also in the case of mass-degenerate daughters with indistinguishable main physical effects—the mimicry breaks down when the next moment, the skewness, is considered. Predicted differences of order one in the root-mean-squares of absolute momenta are too small for current sensitivities.

  15. Sucrose-mediated giant cell formation in the genus Neisseria.

    PubMed

    Johnson, K G; McDonald, I J

    1976-03-01

    Growth of Neisseria perflava, Neisseria cinerea, and Neisseria sicca strain Kirkland in media supplemented with sucrose (0.5 to 5.0% w/v) resulted in the formation of giant cells. Response to sucrose was specific in that a variety of other carbohydrates did not mediate giant cell formation. Giant cells appeared only under growth conditions and did not lyse upon transfer to medium lacking sucrose or upon resuspension in hypotonic media. Reversion of giant to normal cells occurred when giant cells were used as inocula and allowed to multiply in media lacking sucrose.

  16. A Kinetic Model for Cell Damage Caused by Oligomer Formation.

    PubMed

    Hong, Liu; Huang, Ya-Jing; Yong, Wen-An

    2015-10-06

    It is well known that the formation of amyloid fiber may cause invertible damage to cells, although the underlying mechanism has not been fully understood. In this article, a microscopic model considering the detailed processes of amyloid formation and cell damage is constructed based on four simple assumptions, one of which is that cell damage is raised by oligomers rather than mature fibrils. By taking the maximum entropy principle, this microscopic model in the form of infinite mass-action equations together with two reaction-convection partial differential equations (PDEs) has been greatly coarse-grained into a macroscopic system consisting of only five ordinary differential equations (ODEs). With this simple model, the effects of primary nucleation, elongation, fragmentation, and protein and seeds concentration on amyloid formation and cell damage have been extensively explored and compared with experiments. We hope that our results will provide new insights into the quantitative linkage between amyloid formation and cell damage.

  17. Adolescents with Nonresident Fathers: Are Daughters more Disadvantaged than Sons?

    PubMed Central

    Mitchell, Katherine Stamps; Booth, Alan; King, Valarie

    2009-01-01

    This study examined sons' and daughters' involvement with nonresident fathers and associated outcomes (N=4,663). Results indicate that sons and daughters report equal involvement with nonresident fathers on most measures of father investment, although sons report more overnight visits, sports, and movies, and feeling closer to their fathers compared to daughters. Sons and daughters generally benefit from nonresident father involvement in the same way in internalizing and externalizing problems and grades. However, feeling close to one's nonresident father is associated with lower internalizing problems for daughters than sons. These findings suggest that nonresident fathers should be encouraged to be equally involved with their sons and daughters, as such involvement is associated with higher levels of well-being for both sons and daughters. PMID:20161448

  18. The Par complex and integrins direct asymmetric cell division in adult intestinal stem cells.

    PubMed

    Goulas, Spyros; Conder, Ryan; Knoblich, Juergen A

    2012-10-05

    The adult Drosophila midgut is maintained by intestinal stem cells (ISCs) that generate both self-renewing and differentiating daughter cells. How this asymmetry is generated is currently unclear. Here, we demonstrate that asymmetric ISC division is established by a unique combination of extracellular and intracellular polarity mechanisms. We show that Integrin-dependent adhesion to the basement membrane induces cell-intrinsic polarity and results in the asymmetric segregation of the Par proteins Par-3, Par-6, and aPKC into the apical daughter cell. Cell-specific knockdown and overexpression experiments suggest that increased activity of aPKC enhances Delta/Notch signaling in one of the two daughter cells to induce terminal differentiation. Perturbing this mechanism or altering the orientation of ISC division results in the formation of intestinal tumors. Our data indicate that mechanisms for intrinsically asymmetric cell division can be adapted to allow for the flexibility in lineage decisions that is required in adult stem cells.

  19. Trichinella spiralis: nurse cell formation with emphasis on analogy to muscle cell repair

    PubMed Central

    Wu, Zhiliang; Sofronic-Milosavljevic, Lj; Nagano, Isao; Takahashi, Yuzo

    2008-01-01

    Trichinella infection results in formation of a capsule in infected muscles. The capsule is a residence of the parasite which is composed of the nurse cell and fibrous wall. The process of nurse cell formation is complex and includes infected muscle cell response (de-differentiation, cell cycle re-entry and arrest) and satellite cell responses (activation, proliferation and differentiation). Some events that occur during the nurse cell formation are analogous to those occurring during muscle cell regeneration/repair. This article reviews capsule formation with emphasis on this analogy. PMID:18710582

  20. Mechanisms behind signet ring cell carcinoma formation.

    PubMed

    Fukui, Yasuhisa

    2014-08-08

    Signet ring cell carcinomas are highly malignant dedifferentiated adenocarcinomas. There are no cell-cell interactions between these round-shaped cells. They contain huge numbers of vacuoles, filled with mucins, which are secreted from the cells. The mechanism behind this phenotype has recently begun to be elucidated. In highly differentiated adenocarcinomas the ErbB2/ErbB3 complex is activated, which is followed by phosphatidylinositol 3-kinase (PI3K) activation. p38 MAP kinase is activated downstream of PI3K and adherens junctions are disrupted via Rac1 activation. Loss of adherens junctions leads to the disappearance of tight junctions, which results in a loss of cell-cell interactions. Secretion of mucin is enhanced by activation of PI3K. One of the mucins - Muc4 - can activate ErbB2. Under normal conditions Muc4 and ErbB2 are separated by adherens and tight junctions, however in signet ring cells they are able to interact, since these junctions have been lost. Therefore, an activation loop is formed, consisting of ERbB2/ErbB3-Muc4-ErbB2/ErbB3. As a result, the ErbB2/ErbB3 signaling pathway becomes constitutively activated, cell-cell interactions are lost, and signet ring carcinomas are formed. As a result of constitutive activation of the ErbB2/ErbB3 complex, cell growth is continuously enhanced. Some signet ring cell carcinomas have been found to have mutations in the E-cadherin gene, which fits the above hypothesis. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. User`s manual for the DAD-1 data acquisition daughter board for the SuperCard-2

    SciTech Connect

    Ferron, J.R.

    1993-05-01

    A detailed description of how to use the DAD-1 data acquisition daughter board is given. The DAD-1 daughter board is used with the SuperCard-2, a VME format processor board manufactured by CSP Inc. that is based on the Intel i860 microprocessor. The daughter board provides high speed acquisition of digital data through a general purpose input port. Data are transferred through direct memory access operations to the memory on the SuperCard-2 board at a rate up to 40 million, 14 bit samples per second. A first-in, first-out memory is used to buffer the data during the transfer. Several different data acquisition operating modes are available that make a combination of a SuperCard-2 processor board and a DAD-1 daughter board suitable for a wide range of real time data analysis and feedback control functions.

  2. Alpha particle spectra and microdosimetry of radon daughters

    SciTech Connect

    Caswell, R.S.; Coyne, J.J.

    1992-12-31

    We are interested in understanding the physics of the process by which radon-daughter alpha particles irradiate cells, leading to the induction of cancer. We are focusing initially on two aspects: the alpha spectra incident upon cells, which are needed for input to biophysical models of cancer induction; and microdosimetric spectra and parameters which give information on radiation quality. Adapting an analytical method previously developed for neutron radiation, we have calculated the alpha-particle slowing-down spectra (the spectra incident upon cells) and, subsequently, the microdosimetric spectra and parameters for various cell nuclei or site diameters. Results will be presented from three modes of program operation. MODE 1 is for the thin, plane source of radon-daughter activity adjacent to the epithelium. MODE 2 is for the thick source layer (the mucous-serous layer) adjacent to the epithelium. MODE4 is for cylindrical airways of various radii, lined by the mucous-serous layer. MODE 1 is most useful for understanding the problem; MODE 4 is most anatomically relevant. MODE 3 is not discussed in this paper. Alpha-particle spectra and microdosimetric spectra and parameters are studied as a function of cell depth, {sup 218}Po/{sup 214}Po ratio, airway radius, and cell nucleus or the site size. Also available from the calculation is mean dose as a function of depth below the airway surface. The results described here are available on personal computer diskettes. We are beginning to compare our studies with the calculations of other workers and plan to extend the calculations to the nanometer target level.

  3. Acidosis Promotes Metastasis Formation by Enhancing Tumor Cell Motility.

    PubMed

    Riemann, A; Schneider, B; Gündel, D; Stock, C; Gekle, M; Thews, O

    2016-01-01

    The tumor microenvironment is characterized by hypoxia, acidosis as well as other metabolic and biochemical alterations. Its role in cancer progression is increasingly appreciated especially on invasive capacity and the formation of metastasis. The effect of acidosis on metastasis formation of two rat carcinoma cell lines was studied in the animal model. In order to analyze the pH dependency of different steps of metastasis formation, invasiveness, cell adhesion and migration of AT-1 prostate cancer cells as well as possible underlying cell signaling pathways were studied in vitro. Acidosis significantly increased the formation of lung metastases of both tumor cell lines in vivo. In vitro, extracellular acidosis neither enhanced invasiveness nor affected cell adhesion to a plastic or to an endothelial layer. However, cellular motility was markedly elevated at pH 6.6 and this effect was sustained even when extracellular pH was switched back to pH 7.4. When analyzing the underlying mechanism, a prominent role of ROS in the induction of migration was observed. Signaling through the MAP kinases ERK1/2 and p38 as well as Src family kinases was not involved. Thus, cancer cells in an acidic microenvironment can acquire enhanced motility, which is sustained even if the tumor cells leave their acidic microenvironment e.g. by entering the blood stream. This increase depended on elevated ROS production and may contribute to the augmented formation of metastases of acidosis-primed tumor cells in vivo.

  4. Mathematical modeling of dormant cell formation in growing biofilm

    PubMed Central

    Chihara, Kotaro; Matsumoto, Shinya; Kagawa, Yuki; Tsuneda, Satoshi

    2015-01-01

    Understanding the dynamics of dormant cells in microbial biofilms, in which the bacteria are embedded in extracellular matrix, is important for developing successful antibiotic therapies against pathogenic bacteria. Although some of the molecular mechanisms leading to bacterial persistence have been speculated in planktonic bacterial cell, how dormant cells emerge in the biofilms of pathogenic bacteria such as Pseudomonas aeruginosa remains unclear. The present study proposes four hypotheses of dormant cell formation; stochastic process, nutrient-dependent, oxygen-dependent, and time-dependent processes. These hypotheses were implemented into a three-dimensional individual-based model of biofilm formation. Numerical simulations of the different mechanisms yielded qualitatively different spatiotemporal distributions of dormant cells in the growing biofilm. Based on these simulation results, we discuss what kinds of experimental studies are effective for discriminating dormant cell formation mechanisms in biofilms. PMID:26074911

  5. Shared vision between fathers and daughters in family businesses: the determining factor that transforms daughters into successors

    PubMed Central

    Overbeke, Kathy K.; Bilimoria, Diana; Somers, Toni

    2015-01-01

    Family businesses are critical to the United States economy, employing 63% of the workforce and generating 57% of GDP (University of Vermont, 2014). Family business continuity, however, remains elusive as approximately 70% of family businesses do not survive the second generation (Poza, 2013). In order to augment our understanding of how next generation leaders are chosen in family businesses, we examine daughter succession. Using a sample of pairs of family business fathers and daughters and drawing on an earlier study of the dearth of successor daughters in family businesses (Overbeke et al., 2013), we reveal that shared vision between fathers and daughters is central to daughter succession. Self-efficacy and gender norms influence shared vision and when fathers and daughters share a vision for the future of the company, daughters are likely to be transformed into successors. PMID:26074830

  6. Shared vision between fathers and daughters in family businesses: the determining factor that transforms daughters into successors.

    PubMed

    Overbeke, Kathy K; Bilimoria, Diana; Somers, Toni

    2015-01-01

    Family businesses are critical to the United States economy, employing 63% of the workforce and generating 57% of GDP (University of Vermont, 2014). Family business continuity, however, remains elusive as approximately 70% of family businesses do not survive the second generation (Poza, 2013). In order to augment our understanding of how next generation leaders are chosen in family businesses, we examine daughter succession. Using a sample of pairs of family business fathers and daughters and drawing on an earlier study of the dearth of successor daughters in family businesses (Overbeke et al., 2013), we reveal that shared vision between fathers and daughters is central to daughter succession. Self-efficacy and gender norms influence shared vision and when fathers and daughters share a vision for the future of the company, daughters are likely to be transformed into successors.

  7. African American mother-daughter communication about sex and daughters' sexual behavior: does college racial composition make a difference?

    PubMed

    Bynum, Mia Smith

    2007-04-01

    This study examined the influence of African American mothers' communication about sexual topics on the sexual attitudes and behavior of their college-enrolled daughters. Daughters were enrolled at a historically Black college/university (HBCU) or a predominantly White institution (PWI) to assess whether and how college racial context might affect daughters' sexual attitudes and behavior. Findings indicated that daughters at the HBCU had less permissive attitudes about premarital sex than their counterparts at the PWI. This result was especially true for daughters of mothers with more conservative attitudes about premarital sex and who discussed such topics infrequently. Last, the combination of positive mother-daughter communication and fewer discussions about sexual topics resulted in lower levels of sexual experience among the daughters.

  8. Membrane tether formation from blebbing cells.

    PubMed Central

    Dai, J; Sheetz, M P

    1999-01-01

    Membrane tension has been proposed to be important in regulating cell functions such as endocytosis and cell motility. The apparent membrane tension has been calculated from tether forces measured with laser tweezers. Both membrane-cytoskeleton adhesion and membrane tension contribute to the tether force. Separation of the plasma membrane from the cytoskeleton occurs in membrane blebs, which could remove the membrane-cytoskeleton adhesion term. In renal epithelial cells, tether forces are significantly lower on blebs than on membranes that are supported by cytoskeleton. Furthermore, the tether forces are equal on apical and basolateral blebs. In contrast, tether forces from membranes supported by the cytoskeleton are greater in apical than in basolateral regions, which is consistent with the greater apparent cytoskeletal density in the apical region. We suggest that the tether force on blebs primarily contains only the membrane tension term and that the membrane tension may be uniform over the cell surface. Additional support for this hypothesis comes from observations of melanoma cells that spontaneously bleb. In melanoma cells, tether forces on blebs are proportional to the radius of the bleb, and as large blebs form, there are spikes in the tether force in other cell regions. We suggest that an internal osmotic pressure inflates the blebs, and the pressure calculated from the Law of Laplace is similar to independent measurements of intracellular pressures. When the membrane tension term is subtracted from the apparent membrane tension over the cytoskeleton, the membrane-cytoskeleton adhesion term can be estimated. In both cell systems, membrane-cytoskeleton adhesion was the major factor in generating the tether force. PMID:10585959

  9. Foam cell formation by particulate matter (PM) exposure: a review.

    PubMed

    Cao, Yi; Long, Jimin; Ji, Yuejia; Chen, Gui; Shen, Yuexin; Gong, Yu; Li, Juan

    2016-11-01

    Increasing evidence suggests that exposure of particulate matter (PM) from traffic vehicles, e.g., diesel exhaust particles (DEP), was associated with adverse vascular effects, e.g., acceleration of atherosclerotic plaque progression. By analogy, engineered nanoparticles (NPs) could also induce similar effects. The formation of lipid laden foam cells, derived predominately from macrophages and vascular smooth muscle cells (VSMC), is closely associated with the development of atherosclerosis and adverse vascular effects. We reviewed current studies about particle exposure-induced lipid laden foam cell formation. In vivo studies using animal models have shown that exposure of air pollution by PM promoted lipid accumulation in alveolar macrophages or foam cells in plaques, which was likely associated with pulmonary inflammation or systemic oxidative stress, but not blood lipid profile. In support of these findings, in vitro studies showed that direct exposure of cultured macrophages to DEP or NP exposure, with or without further exposure to external lipids, promoted intracellular lipid accumulation. The mechanisms remained unknown. Although a number studies found increased reactive oxygen species (ROS) or an adaptive response to oxidative stress, the exact role of oxidative stress in mediating particle-induced foam cell formation requires future research. There is currently lack of reports concerning VSMC as a source for foam cells induced by particle exposure. In the future, it is necessary to explore the role of foam cell formation in particle exposure-induced atherosclerosis development. In addition, the formation of VSMC derived foam cells by particle exposure may also need extensive studies.

  10. Chloride influx provokes lamellipodium formation in microglial cells.

    PubMed

    Zierler, Susanna; Frei, Eva; Grissmer, Stephan; Kerschbaum, Hubert H

    2008-01-01

    Lamellipodium extension and retraction is the driving force for cell migration. Although several studies document that activation of chloride channels are essential in cell migration, little is known about their contribution in lamellipodium formation. To address this question, we characterized chloride channels and transporters by whole cell recording and RT-PCR, respectively, as well as quantified lamellipodium formation in murine primary microglial cells as well as the microglial cell-line, BV-2, using time-lapse microscopy. The repertoire of chloride conducting pathways in BV-2 cells included, swelling-activated chloride channels as well as the KCl cotransporters, KCC1, KCC2, KCC3, and KCC4. Swelling-activated chloride channels were either activated by a hypoosmotic solution or by a high KCl saline, which promotes K(+) and Cl(-) influx instead of efflux by KCCs. Conductance through swelling-activated chloride channels was completely blocked by flufenamic acid (200 microM), SITS (1 mM) and DIOA (10 microM). By exposing primary microglial cells or BV-2 cells to a high KCl saline, we observed a local swelling, which developed into a prominent lamellipodium. Blockade of chloride influx by flufenamic acid (200 microM) or DIOA (10 microM) as well as incubation of cells in a chloride-free high K(+) saline suppressed formation of a lamellipodium. We assume that local swellings, established by an increase in chloride influx, are a general principle in formation of lamellipodia in eukaryotic cells.

  11. Radon and radon daughter measurements in solar buildings.

    PubMed

    George, A C; Knutson, E O; Franklin, H

    1983-08-01

    Measurements of radon and radon daughters in 11 buildings in five states, using active or passive solar heating, showed no significant excess in concentrations over the levels measured in buildings with conventional heating systems. Radon levels in two buildings using rock storage in their active solar systems exceeded the U.S. Nuclear Regulatory Commission's limit of 3 pCi/l. for continuous exposure in uncontrolled areas. In the remainder of the buildings, radon concentrations were found to be at levels considered to be normal. It appears that the slightly elevated indoor radon concentrations result from the local geological formations and from the tightening of the buildings rather than as a result of the solar heating technology.

  12. Parents' personality clusters and eating disordered daughters' personality and psychopathology.

    PubMed

    Amianto, Federico; Ercole, Roberta; Marzola, Enrica; Abbate Daga, Giovanni; Fassino, Secondo

    2015-11-30

    The present study explores how parents' personality clusters relate to their eating disordered daughters' personality and psychopathology. Mothers and fathers were tested with the Temperament Character Inventory. Their daughters were assessed with the following: Temperament and Character Inventory, Eating Disorder Inventory-2, Symptom Checklist-90, Parental Bonding Instrument, Attachment Style Questionnaire, and Family Assessment Device. Daughters' personality traits and psychopathology scores were compared between clusters. Daughters' features were related to those of their parents. Explosive/adventurous mothers were found to relate to their daughters' borderline personality profile and more severe interoceptive awareness. Mothers' immaturity was correlated to their daughters' higher character immaturity, inadequacy, and depressive feelings. Fathers who were explosive/methodic correlated with their daughters' character immaturity, severe eating, and general psychopathology. Fathers' character immaturity only marginally related to their daughters' specific features. Both parents' temperament clusters and mothers' character clusters related to patients' personality and eating psychopathology. The cluster approach to personality-related dynamics of families with an individual affected by an eating disorder expands the knowledge on the relationship between parents' characteristics and daughters' illness, suggesting complex and unique relationships correlating parents' personality traits to their daughters' disorder. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Effects of asbestos fibers on cell division, cell survival, and formation of thioguanine-resistant mutants in Chinese hamster ovary cells

    SciTech Connect

    Kenne, K.; Ljungquist, S.; Ringertz, N.R.

    1986-04-01

    The ability of crocidolite fibers to induce point mutations and mitotic abnormalities in Chinese hamster ovary (CHO) cells was examined in cell cultures. The purpose has been to study the possibilities for establishing in vitro test methods to quantify genetic damage induced by asbestos and other mineral fibers. Results obtained with the CHO/hypoxanthine guanine phosphoribosyl transferase system indicated that crocidolite fibers per se do not significantly increase the number of thioguanine-resistant mutants. Crocidolite fibers also failed to potentiate the mutagenicity of benzo(a)pyrene. Time-lapse cinematography and microscopy showed that asbestos (crocidolite) fibers were markedly cytotoxic. Among surviving cells some underwent abnormal cell divisions which resulted in multi- and micronucleate cells. Many cells that contained a few asbestos fibers, however, underwent mitosis and successfully formed two mononucleate daughter cells capable of further divisions. Individual, fiber-containing cells were examined by time-lapse television recordings for 4-5 days. During this time period some cells underwent six divisions and generated an almost normal number of daughter cells. Cells which contained fibers that were longer or equivalent to the diameter of the mitotic cell (20 ..mu..m), showed different forms of mitotic abnormalities. The frequency of multinucleate cells was drastically increased following exposure to asbestos fibers. Only rarely, however, did these cells divide to produce viable daughter cells capable of continued cell multiplication. The frequency of multinucleate cells was dependent on the dose of exposure to asbestos fibers and could possible be used as an index of the degree of mitotic disturbances induced by mineral fibers.

  14. Suppression of T cell-induced osteoclast formation

    SciTech Connect

    Karieb, Sahar; Fox, Simon W.

    2013-07-12

    Highlights: •Genistein and coumestrol prevent activated T cell induced osteoclast formation. •Anti-TNF neutralising antibodies prevent the pro-osteoclastic effect of activated T cells. •Phytoestrogens inhibit T cell derived TNF alpha and inflammatory cytokine production. •Phytoestrogens have a broader range of anti-osteoclastic actions than other anti-resorptives. -- Abstract: Inhibition of T cell derived cytokine production could help suppress osteoclast differentiation in inflammatory skeletal disorders. Bisphosphonates are typically prescribed to prevent inflammatory bone loss but are not tolerated by all patients and are associated with an increased risk of osteonecrosis of the jaw. In light of this other anti-resorptives such as phytoestrogens are being considered. However the effect of phytoestrogens on T cell-induced osteoclast formation is unclear. The effect of genistein and coumestrol on activated T cell-induced osteoclastogenesis and cytokine production was therefore examined. Concentrations of genistein and coumestrol (10{sup −7} M) previously shown to directly inhibit osteoclast formation also suppressed the formation of TRAP positive osteoclast induced by con A activated T cells, which was dependent on inhibition of T cell derived TNF-α. While both reduced osteoclast formation their mechanism of action differed. The anti-osteoclastic effect of coumestrol was associated with a dual effect on con A induced T cell proliferation and activation; 10{sup −7} M coumestrol significantly reducing T cell number (0.36) and TNF-α (0.47), IL-1β (0.23) and IL-6 (0.35) expression, whereas genistein (10{sup −7} M) had no effect on T cell number but a more pronounced effect on T cell differentiation reducing expression of TNF-α (0.49), IL-1β (0.52), IL-6 (0.71) and RANKL (0.71). Phytoestrogens therefore prevent the pro-osteoclastic action of T cells suggesting they may have a role in the control of inflammatory bone loss.

  15. Mutagenicity of radon and radon daughters. Annual progress report

    SciTech Connect

    Evans, H.H.

    1991-12-01

    The objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose rate dependence and the nature of the DNA lesion will be studied, using the thymidine kinase and HPRT loci to measure mutation frequency. A deficiency in DNA repair is shown to lead to a greater proportion of mutants with intergenic lesions. The cytotoxic effects of radon and its daughters are similar in human TK6 lymphoblasts and mouse L5178Y lymphoblasts, the cell line used in previous experiments. The results of molecular analysis of four spontaneous and 25 X-radiation induced HPRT{sup {minus}} mutants. Eleven radon-induced HPRT{sup {minus}} mutants have been isolated, and will be analyzed in a similar fashion. 9 figs.

  16. The cell equator - more than poles apart.

    PubMed

    Dhar, Pawan

    2004-03-01

    Cytokinesis is the last ritual of a dividing cell. Determining the position and horizon of the cell furrow is important for equal distribution of cytoplasmic content between the two daughter cells. The traditional view promotes a classical sequence of bipolar spindle formation followed by cytokinesis. However, a new understanding has recently emerged that uncouples these events. The cell-furrow formation seems to ignore spindle polarity and is instead dependent on the stability and dynamics of cortical microtubules.

  17. Signaling events in pathogen-induced macrophage foam cell formation.

    PubMed

    Shaik-Dasthagirisaheb, Yazdani B; Mekasha, Samrawit; He, Xianbao; Gibson, Frank C; Ingalls, Robin R

    2016-08-01

    Macrophage foam cell formation is a key event in atherosclerosis. Several triggers induce low-density lipoprotein (LDL) uptake by macrophages to create foam cells, including infections with Porphyromonas gingivalis and Chlamydia pneumoniae, two pathogens that have been linked to atherosclerosis. While gene regulation during foam cell formation has been examined, comparative investigations to identify shared and specific pathogen-elicited molecular events relevant to foam cell formation are not well documented. We infected mouse bone marrow-derived macrophages with P. gingivalis or C. pneumoniae in the presence of LDL to induce foam cell formation, and examined gene expression using an atherosclerosis pathway targeted plate array. We found over 30 genes were significantly induced in response to both pathogens, including PPAR family members that are broadly important in atherosclerosis and matrix remodeling genes that may play a role in plaque development and stability. Six genes mainly involved in lipid transport were significantly downregulated. The response overall was remarkably similar and few genes were regulated in a pathogen-specific manner. Despite very divergent lifestyles, P. gingivalis and C. pneumoniae activate similar gene expression profiles during foam cell formation that may ultimately serve as targets for modulating infection-elicited foam cell burden, and progression of atherosclerosis.

  18. BONE FORMATION INDUCED IN MOUSE THIGH BY CULTURED HUMAN CELLS

    PubMed Central

    Anderson, H. Clarke; Coulter, P. R.

    1967-01-01

    Cultured FL human amnion cells injected intramuscularly into cortisone-conditioned mice proliferate to form discrete nodules which become surrounded by fibroblasts. Within 12 days, fibroblastic zones differentiate into cartilage which calcifies to form bone. Experiments were conducted to test the hypothesis that FL cells behave as an inductor of bone formation. In the electron microscope, FL cells were readily distinguished from surrounding fibroblasts. Transitional forms between the two cell types were not recognized. Stains for acid mucopolysaccharides emphasized the sharp boundary between metachromatic fibroblastic and cartilaginous zones and nonmetachromatic FL cells. 35S was taken up preferentially by fibroblasts and chondrocytes and then deposited extracellularly in a manner suggesting active secretion of sulfated mucopolysaccharides. FL cells showed negligible 35S utilization and secretion. FL cells, labeled in vitro with thymidine-3H, were injected and followed radioautographically, during bone formation. Nuclear label of injected FL cells did not appear in adjacent fibroblasts in quantities sufficient to indicate origin of the latter from FL cells. The minimal fibroblast nuclear labeling seen may represent reutilization of label from necrotic FL cells. It is suggested that FL cells injected into the mouse thigh induced cartilage and bone formation by host fibroblasts. PMID:4226746

  19. Bone formation induced in mouse thigh by cultured human cells.

    PubMed

    Anderson, H C; Coulter, P R

    1967-04-01

    Cultured FL human amnion cells injected intramuscularly into cortisone-conditioned mice proliferate to form discrete nodules which become surrounded by fibroblasts. Within 12 days, fibroblastic zones differentiate into cartilage which calcifies to form bone. Experiments were conducted to test the hypothesis that FL cells behave as an inductor of bone formation. In the electron microscope, FL cells were readily distinguished from surrounding fibroblasts. Transitional forms between the two cell types were not recognized. Stains for acid mucopolysaccharides emphasized the sharp boundary between metachromatic fibroblastic and cartilaginous zones and nonmetachromatic FL cells. (35)S was taken up preferentially by fibroblasts and chondrocytes and then deposited extracellularly in a manner suggesting active secretion of sulfated mucopolysaccharides. FL cells showed negligible (35)S utilization and secretion. FL cells, labeled in vitro with thymidine-(3)H, were injected and followed radioautographically, during bone formation. Nuclear label of injected FL cells did not appear in adjacent fibroblasts in quantities sufficient to indicate origin of the latter from FL cells. The minimal fibroblast nuclear labeling seen may represent reutilization of label from necrotic FL cells. It is suggested that FL cells injected into the mouse thigh induced cartilage and bone formation by host fibroblasts.

  20. The mother-daughter love affair across the generations.

    PubMed

    Klockars, L; Sirola, R

    2001-01-01

    The relationship between mother and daughter is the basis for all love relationships throughout life. Through the eyes and hands of the mother, the intimate and caring nature of love is transmitted from generation to generation. Mother-daughter love is also the beginning of heterosexual love and of sensual pleasure. However, sexuality separates and alienates mother and daughter. As a consequence, the daughter's identification with the mother becomes the most important transmitter of love. We review psychoanalytic studies of the development and fate of the mother-daughter love relationship, with particular attention to the change of the daughter's early love for the mother to identification with the mother and falling in love with a man, and to the significance of sexuality in this developmental process.

  1. The Formation of Germ Cell for Organizational Learning

    ERIC Educational Resources Information Center

    Ivaldi, Silvia; Scaratti, Giuseppe

    2016-01-01

    Purpose: The aim of the paper is to analyze the process of "germ cell" formation by framing it as an opportunity for promoting organizational learning and transformation. The paper aims to specifically answer two research questions: Why does the "germ cell" have a pivotal role in organization's transformation? and Which…

  2. Sexual biofilm formation in Candida tropicalis opaque cells.

    PubMed

    Jones, Stephen K; Hirakawa, Matthew P; Bennett, Richard J

    2014-04-01

    Candida albicans and Candida tropicalis are opportunistic fungal pathogens that can transition between white and opaque phenotypic states. White and opaque cells differ both morphologically and in their responses to environmental signals. In C. albicans, opaque cells respond to sexual pheromones by undergoing conjugation, while white cells are induced by pheromones to form sexual biofilms. Here, we show that sexual biofilm formation also occurs in C. tropicalis but, unlike C. albicans, biofilms are formed exclusively by opaque cells. C. tropicalis biofilm formation was dependent on the pheromone receptors Ste2 and Ste3, confirming the role of pheromone signalling in sexual biofilm development. Structural analysis of C. tropicalis sexual biofilms revealed stratified communities consisting of a basal layer of yeast cells and an upper layer of filamentous cells, together with an extracellular matrix. Transcriptional profiling showed that genes involved in pheromone signalling and conjugation were upregulated in sexual biofilms. Furthermore, FGR23, which encodes an agglutinin-like protein, was found to enhance both mating and sexual biofilm formation. Together, these studies reveal that C. tropicalis opaque cells form sexual biofilms with a complex architecture, and suggest a conserved role for sexual agglutinins in mediating mating, cell cohesion and biofilm formation. © 2014 John Wiley & Sons Ltd.

  3. The Formation of Germ Cell for Organizational Learning

    ERIC Educational Resources Information Center

    Ivaldi, Silvia; Scaratti, Giuseppe

    2016-01-01

    Purpose: The aim of the paper is to analyze the process of "germ cell" formation by framing it as an opportunity for promoting organizational learning and transformation. The paper aims to specifically answer two research questions: Why does the "germ cell" have a pivotal role in organization's transformation? and Which…

  4. Sexual Biofilm Formation in Candida tropicalis Opaque Cells

    PubMed Central

    Jones, Stephen K.; Hirakawa, Matthew P.; Bennett, Richard J.

    2014-01-01

    Summary Candida albicans and Candida tropicalis are opportunistic fungal pathogens that can transition between white and opaque phenotypic states. White and opaque cells differ both morphologically and in their responses to environmental signals. In C. albicans, opaque cells respond to sexual pheromones by undergoing conjugation, while white cells are induced by pheromones to form sexual biofilms. Here, we show that sexual biofilm formation also occurs in C. tropicalis but, unlike C. albicans, biofilms are formed exclusively by opaque cells. C. tropicalis biofilm formation was dependent on the pheromone receptors Ste2 and Ste3, confirming the role of pheromone signaling in sexual biofilm development. Structural analysis of C. tropicalis sexual biofilms revealed stratified communities consisting of a basal layer of yeast cells and an upper layer of filamentous cells, together with an extracellular matrix. Transcriptional profiling showed that genes involved in pheromone signaling and conjugation were upregulated in sexual biofilms. Furthermore, FGR23, which encodes an agglutinin-like protein, was found to enhance both mating and sexual biofilm formation. Together, these studies reveal that C. tropicalis opaque cells form sexual biofilms with a complex architecture, and suggest a conserved role for sexual agglutinins in mediating mating, cell cohesion and biofilm formation. PMID:24612417

  5. Mothers and Daughters Go to Work: The Relationship of Mothers' Occupations to Daughters' Career Aspirations.

    ERIC Educational Resources Information Center

    Mickelson, Roslyn Arlin; Velasco, Anne E.

    This paper examines maternal influences on daughters' choices of occupations. Using a survey of high school seniors in Charlotte (North Carolina) as the primary data source, the career choices of adolescent girls and the influences of their mothers' occupations on their occupational expectations were studied. Previous research has suggested that…

  6. Cultural and noncultural predictors of health outcomes in Korean daughter and daughter-in-law caregivers.

    PubMed

    Kim, Jin-Sun; Lee, Eun-Hyun

    2003-01-01

    In Western cultures, adverse health effects resulting from providing care for impaired elders is well documented for family caregivers, but little is known about the health of Korean caregivers. This study examined the level of depression and physical health of 120 daughter and daughter-in-law caregivers who cared for cognitively or functionally impaired elderly in Korea. It was hypothesized that cultural factors would have a greater effect on caregivers' health outcomes than noncultural factors, but, contrary to this expectation, the effects of noncultural factors were found to outweigh those of cultural factors. Moreover, the caregivers in this study reported a relatively high level of depression, and more caregivers rated their own health as "poor" than did Western caregivers in previous studies. Family caregiving for the impaired elderly is stressful and negatively affects Korean caregivers' health outcomes regardless of societal values such as filial piety and familism regarding parent care in Korea. Culturally acceptable and sensible support programs may be useful in sustaining long-term care at home by Korean daughter and daughter-in-law caregivers. Further family caregiving studies in the Korean sociocultural context are recommended.

  7. Cell-fusion method to visualize interphase nuclear pore formation.

    PubMed

    Maeshima, Kazuhiro; Funakoshi, Tomoko; Imamoto, Naoko

    2014-01-01

    In eukaryotic cells, the nucleus is a complex and sophisticated organelle that organizes genomic DNA to support essential cellular functions. The nuclear surface contains many nuclear pore complexes (NPCs), channels for macromolecular transport between the cytoplasm and nucleus. It is well known that the number of NPCs almost doubles during interphase in cycling cells. However, the mechanism of NPC formation is poorly understood, presumably because a practical system for analysis does not exist. The most difficult obstacle in the visualization of interphase NPC formation is that NPCs already exist after nuclear envelope formation, and these existing NPCs interfere with the observation of nascent NPCs. To overcome this obstacle, we developed a novel system using the cell-fusion technique (heterokaryon method), previously also used to analyze the shuttling of macromolecules between the cytoplasm and the nucleus, to visualize the newly synthesized interphase NPCs. In addition, we used a photobleaching approach that validated the cell-fusion method. We recently used these methods to demonstrate the role of cyclin-dependent protein kinases and of Pom121 in interphase NPC formation in cycling human cells. Here, we describe the details of the cell-fusion approach and compare the system with other NPC formation visualization methods. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Model for antibody mediated cell aggregation: rosette formation

    SciTech Connect

    Perelson, A.S.

    1984-01-01

    Models are developed for the formation of cellular aggregates, called rosettes, composed of a central lymphocyte and surrounding antibody coated red blood cells. Kinetic and equilibrium models are considered from both the deterministic and stochastic viewpoints. Analytic solutions are given to the system of nonlinear ordinary differential equations that describe the formation of different size rosettes in the cases of both reversible and irreversible red cell adhesion. A comparison of the stochastic model with experimental data indicates that there may exist heterogeneity within the lymphocyte population with regard to the number of chemical bonds required to bind a red cell to a lymphocyte. 24 references, 2 figures.

  9. Atmosphere purification of radon and radon daughter elements

    DOEpatents

    Stein, L.

    1974-01-01

    A method of removing radon and radon daughter elements from an atmosphere containing these elements by passing the atmosphere through a bed of fluorinating compound whereby the radon and radon daughters are oxidized to their respective fluorides is discussed. These fluorides adhere to the fluorinating compound and are thus removed from the atmosphere which may then be recirculated. A method for recovering radon and separating radon from its daughter elements is also described. (Official Gazette)

  10. Overview of current radon and radon daughter research at LBL

    SciTech Connect

    Not Available

    1983-01-01

    This report provides a brief summary of radon and radon daughter research at Lawrence Berkeley Laboratory. The radon and radon daughter research program has two broad goals: (1) the study of sources of radon and its subsequent transport into houses, and (2) research on the behavior of radon daughters in indoor environments. Additional research effort is directed to several auxiliary areas, including development of instrumentation and monitoring techniques, studies of indoor air movement, and measurement and control of indoor particulate concentrations.

  11. Nanopore formation in neuroblastoma cells following ultrashort electric pulse exposure

    NASA Astrophysics Data System (ADS)

    Roth, Caleb C.; Payne, Jason A.; Wilmink, Gerald J.; Ibey, Bennett L.

    2011-03-01

    Ultrashort or nanosecond electrical pulses (USEP) cause repairable damage to the plasma membranes of cells through formation of nanopores. These nanopores are able to pass small ions such as sodium, calcium, and potassium, but remain impermeable to larger molecules like trypan blue and propidium iodide. What remains uncertain is whether generation of nanopores by ultrashort electrical pulses can inhibit action potentials in excitable cells. In this paper, we explored the sensitivity of excitable cells to USEP using Calcium Green AM 1 ester fluorescence to measure calcium uptake indicative of nanopore formation in the plasma membrane. We determined the threshold for nanopore formation in neuroblastoma cells for three pulse parameters (amplitude, pulse width, and pulse number). Measurement of such thresholds will guide future studies to determine if USEP can inhibit action potentials without causing irreversible membrane damage.

  12. The role of Cbln1 on Purkinje cell synapse formation.

    PubMed

    Ito-Ishida, Aya; Okabe, Shigeo; Yuzaki, Michisuke

    2014-06-01

    Cbln1 is a glycoprotein which belongs to the C1q family. In the cerebellum, Cbln1 is produced and secreted from granule cells and works as a strong synapse organizer between Purkinje cells and parallel fibers, the axons of the granule cells. In this update article, we will describe the molecular mechanisms by which Cbln1 induces synapse formation and will review our findings on the axonal structural changes which occur specifically during this process. We will also describe our recent finding that Cbln1 has a suppressive role in inhibitory synapse formation between Purkinje cells and molecular layer interneurons. Our results have revealed that Cbln1 plays an essential role to establish parallel fiber-Purkinje cell synapses and to regulate balance between excitatory and inhibitory input on Purkinje cells.

  13. Feminist attitudes and mother-daughter relationships in adolescence.

    PubMed

    Notar, M; McDaniel, S A

    1986-01-01

    In spite of the growing amount of research on women's issues, there are few empirical studies of mother-daughter relationships, and almost none on the effects of the major women's movement of our times on relationships between mothers and daughters. In this study of late adolescent daughters' perceptions of their relationships with their mothers, two alternative hypotheses are examined: (1) feminism, with its emphasis on bonding among women, strengthens relations between adolescent daughters and their mothers, or (2) feminism as a force of social change, both attitudinal and behavioral, weakens the adolescent daughter-mother relationship. Based on 102 questionnaires completed by university-age women in the winter of 1983, it was found that the majority of daughters who have a good relationship with their mothers see both themselves and their mothers as feminist. However, these daughters do not attribute their positive mother-daughter relationship explicitly to feminism. For the minority of daughters who claim to have a poor relationship with their mothers, they attribute the problems to feminism.

  14. Mother-daughter in vitro fertilization triplet surrogate pregnancy.

    PubMed

    Michelow, M C; Bernstein, J; Jacobson, M J; McLoughlin, J L; Rubenstein, D; Hacking, A I; Preddy, S; Van der Wat, I J

    1988-02-01

    A successful triplet pregnancy has been established in a surrogate gestational mother following the transfer of five embryos fertilized in vitro. The oocytes were donated by her biological daughter, and the sperm obtained from the daughter's husband. The daughter's infertility followed a total abdominal hysterectomy performed for a postpartum hemorrhage as a result of a placenta accreta. Synchronization of both their menstrual cycles was obtained using oral contraceptive suppression for 2 months, followed by stimulation of both the surrogate gestational mother and her daughter such that embryo transfer would occur at least 48 hr after the surrogate gestational mother's own ovulation. This case raises a number of medical, social, psychological, and ethical issues.

  15. Enhanced product formation in continuous fermentations with microbial cell recycle

    SciTech Connect

    Bull, D.N.; Young, M.D.

    1981-02-01

    The effect of partial recycle of microbial cells on the operation of a chemostat has been investigated for two fermentations. Stable steady states with and without partial cell recycle were obtained for the conversion of d-sorbitol to L-sorbose by Gluconobacter oxydans subsp. suboxydans 1916B and for the conversion of glucose to 2-ketogluconic acid by Serratia marcescens NRRl B-486. The employment of partial cell recycle dramatically increased product formation rates for both fermentations.

  16. UNUSUAL FORMATIONS OF ERGASTOPLASM IN PAROTID ACINOUS CELLS OF MICE

    PubMed Central

    Parks, Harold F.

    1962-01-01

    The ergastoplasm (granular endoplasmic reticulum) of parotid acinous cells of the mouse is described with special emphasis on unusual forms of this membranous system. In the majority of the acinous cells the ergastoplasm appeared in sections to consist of a large number of separate flattened cisternae. In some acinous cells, however, the ergastoplasm was disposed as a very small number of large membranous formations. Although extensive and complicated in form, these latter formations could be seen, from the examination of a single section, to consist of a single expanse of membrane continuous with the nuclear envelope. Certain acinous cells exhibited ergastoplasmic formations which appeared to represent intermediate stages of a fragmentation or metamorphosis of the larger formations toward the more usual form of ergastoplasm. These observations suggest the possibility that the early elaboration of ergastoplasm consists in the production, in relation to the nuclear envelope, of large, complicated membranous formations that subsequently sever their connection with the nuclear envelope and form a large number of separate, or tenuously connected, cisternae. The majority of the large, complicated ergastoplasmic formations were seen in parotid glands of mice that had been starved for 4 days and subsequently fed for a variable number of hours, but some were found in glands that were not subjected to experimental treatment. The tissues studied were prepared for electron microscopic examination by fixation in osmium tetroxide, dehydration in alcohol, imbedding in butyl methacrylate, sectioning with a glass knife, staining with lead hydroxide, and sandwiching with formvar. PMID:14483961

  17. Germ cell formation from embryonic stem cells and the use of somatic cell nuclei in oocytes.

    PubMed

    Pelosi, Emanuele; Forabosco, Antonino; Schlessinger, David

    2011-03-01

    Embryonic stem cells (ESCs) have remarkable properties of pluripotency and self-renewal, along with the retention of chromosomal integrity. Germ cells function as a kind of "transgenerational stem cells," transmitting genetic information from one generation to the next. The formation of putative primordial germ cells (PGCs) and germ cells from mouse and human ESCs (hESCs) has, in fact, been shown, and the apparent derivation of functional mouse male gametes has also been described. Additionally, investigators have successfully reprogrammed somatic nuclei into a pluripotent state by inserting them into ESCs or oocytes. This would enable the generation of ESCs genetically identical to the somatic cell donor and their use in cell therapy. However, these methodologies are still inefficient and their mechanisms poorly understood. Until full comprehension of these processes is obtained, clinical applications remain remote. Nevertheless, they represent promising tools in the future, enhancing methods of therapeutic cloning and infertility treatment.

  18. Pulp stem cells: implication in reparative dentin formation.

    PubMed

    Dimitrova-Nakov, Sasha; Baudry, Anne; Harichane, Yassine; Kellermann, Odile; Goldberg, Michel

    2014-04-01

    Many dental pulp stem cells are neural crest derivatives essential for lifelong maintenance of tooth functions and homeostasis as well as tooth repair. These cells may be directly implicated in the healing process or indirectly involved in cell-to-cell diffusion of paracrine messages to resident (pulpoblasts) or nonresident cells (migrating mesenchymal cells). The identity of the pulp progenitors and the mechanisms sustaining their regenerative capacity remain largely unknown. Taking advantage of the A4 cell line, a multipotent stem cell derived from the molar pulp of mouse embryo, we investigated the capacity of these pulp-derived precursors to induce in vivo the formation of a reparative dentin-like structure upon implantation within the pulp of a rodent incisor or a first maxillary molar after surgical exposure. One month after the pulp injury alone, a nonmineralized fibrous matrix filled the mesial part of the coronal pulp chamber. Upon A4 cell implantation, a mineralized osteodentin was formed in the implantation site without affecting the structure and vitality of the residual pulp in the central and distal parts of the pulp chamber. These results show that dental pulp stem cells can induce the formation of reparative dentin and therefore constitute a useful tool for pulp therapies. Finally, reparative dentin was also built up when A4 progenitors were performed by alginate beads, suggesting that alginate is a suitable carrier for cell implantation in teeth.

  19. Laser-induced endothelial cell activation supports fibrin formation

    PubMed Central

    Atkinson, Ben T.; Jasuja, Reema; Chen, Vivien M.; Nandivada, Prathima; Furie, Bruce

    2010-01-01

    Laser-induced vessel wall injury leads to rapid thrombus formation in an animal thrombosis model. The target of laser injury is the endothelium. We monitored calcium mobilization to assess activation of the laser-targeted cells. Infusion of Fluo-4 AM, a calcium-sensitive fluorochrome, into the mouse circulation resulted in dye uptake in the endothelium and circulating hematopoietic cells. Laser injury in mice treated with eptifibatide to inhibit platelet accumulation resulted in rapid calcium mobilization within the endothelium. Calcium mobilization correlated with the secretion of lysosomal-associated membrane protein 1, a marker of endothelium activation. In the absence of eptifibatide, endothelium activation preceded platelet accumu-lation. Laser activation of human umbilical vein endothelial cells loaded with Fluo-4 resulted in a rapid increase in calcium mobilization associated cell fluorescence similar to that induced by adenosine diphosphate (10μM) or thrombin (1 U/mL). Laser activation of human umbilical vein endothelial cells in the presence of corn trypsin inhibitor treated human plasma devoid of platelets and cell microparticles led to fibrin for-mation that was inhibited by an inhibitory monoclonal anti–tissue factor antibody. Thus laser injury leads to rapid endothelial cell activation. The laser activated endothelial cells can support formation of tenase and prothrombinase and may be a source of activated tissue factor as well. PMID:20675401

  20. The spindle position checkpoint: how to deal with spindle misalignment during asymmetric cell division in budding yeast.

    PubMed

    Fraschini, Roberta; Venturetti, Marianna; Chiroli, Elena; Piatti, Simonetta

    2008-06-01

    During asymmetric cell division, spindle positioning is critical to ensure the unequal segregation of polarity factors and generate daughter cells with different sizes or fates. In budding yeast the boundary between mother and daughter cell resides at the bud neck, where cytokinesis takes place at the end of the cell cycle. Since budding and bud neck formation occur much earlier than bipolar spindle formation, spindle positioning is a finely regulated process. A surveillance device called the SPOC (spindle position checkpoint) oversees this process and delays mitotic exit and cytokinesis until the spindle is properly oriented along the division axis, thus ensuring genome stability.

  1. Mast Cells Contribute to Scar Formation During Fetal Wound Healing

    PubMed Central

    Wulff, Brian C.; Parent, Allison E.; Meleski, Melissa A.; DiPietro, Luisa A.; Schrementi, Megan E.; Wilgus, Traci A.

    2011-01-01

    Scar formation is a potentially detrimental process of tissue restoration in adults, affecting organ form and function. During fetal development, cutaneous wounds heal without inflammation or scarring at early stages of development, but begin to heal with significant inflammation and scarring as the skin becomes more mature. One possible cell type that could regulate the change from scarless to fibrotic healing is the mast cell. We show here that dermal mast cells in scarless wounds generated at embryonic day 15 (E15) are fewer in number, less mature and do not degranulate in response to wounding as effectively as mast cells of fibrotic wounds made at embryonic day 18 (E18). Differences were also observed between cultured mast cells from E15 and E18 skin with regard to degranulation and preformed cytokine levels. Injection of mast cell lysates into E15 wounds disrupted scarless healing, suggesting that mast cells interfere with scarless repair. Finally, wounds produced at E18, which normally heal with a scar, healed with significantly smaller scars in mast cell-deficient KitW/W-v mice compared to Kit+/+ littermates. Together, these data suggest that mast cells enhance scar formation, and that these cells may mediate the transition from scarless to fibrotic healing during fetal development. PMID:21993557

  2. Cell Adhesion in Epidermal Development and Barrier Formation

    PubMed Central

    Sumigray, Kaelyn D.; Lechler, Terry

    2015-01-01

    Cell–cell adhesions are necessary for structural integrity and barrier formation of the epidermis. Here, we discuss insights from genetic and cell biological studies into the roles of individual cell–cell junctions and their composite proteins in regulating epidermal development and function. In addition to individual adhesive functions, we will discuss emerging ideas on mechanosensation/transduction of junctions in the epidermis, noncanonical roles for adhesion proteins, and crosstalk/interdependencies between the junctional systems. These studies have revealed that cell adhesion proteins are connected to many aspects of tissue physiology including growth control, differentiation, and inflammation. PMID:25733147

  3. Modeling cell-death patterning during biofilm formation

    NASA Astrophysics Data System (ADS)

    Ghosh, Pushpita; Ben-Jacob, Eshel; Levine, Herbert

    2013-12-01

    Self-organization by bacterial cells often leads to the formation of a highly complex spatially-structured biofilm. In such a bacterial biofilm, cells adhere to each other and are embedded in a self-produced extracellular matrix (ECM). Bacillus substilis bacteria utilize localized cell-death patterns which focuses mechanical forces to form wrinkled sheet-like structures in three dimensions. A most intriguing feature underlying this biofilm formation is that vertical buckling and ridge location is biased to occur in region of high cell-death. Here we present a spatially extended model to investigate the role of the bacterial secreted ECM during the biofilm formation and the self-organization of cell-death. Using this reaction-diffusion model we show that the interaction between the cell's motion and the ECM concentration gives rise to a self-trapping instability, leading to variety of cell-death patterns. The resultant spot patterns generated by our model are shown to be in semi-quantitative agreement with recent experimental observation.

  4. Kinetics of Formation and Asymmetrical Distribution of Hsp104-Bound Protein Aggregates in Yeast.

    PubMed

    Paoletti, Camille; Quintin, Sophie; Matifas, Audrey; Charvin, Gilles

    2016-04-12

    Budding yeast cells have a finite replicative life span; that is, a mother cell produces only a limited number of daughter cells before it slows division and dies. Despite the gradual aging of the mother cell, all daughters are born rejuvenated and enjoy a full replicative lifespan. It has been proposed that entry of mother cells into senescence is driven by the progressive accumulation and retention of damaged material, including protein aggregates. This additionally allows the daughter cells to be born damage free. However, the mechanism underlying such asymmetrical segregation of protein aggregates by mother and daughter cells remains controversial, in part because of the difficulties inherent in tracking the dynamics and fate of protein aggregates in vivo. To overcome such limitations, we have developed single-cell real-time imaging methodology to track the formation of heat-induced protein aggregates in otherwise unperturbed dividing cells. By combining the imaging data with a simple computational model of protein aggregation, we show that the establishment of asymmetrical partitioning of protein aggregates upon division is driven by the large bud-specific dilution rate associated with polarized growth and the absence of significant mother/bud exchange of protein aggregates during the budded phase of the cell cycle. To our knowledge, this study sheds new light on the mechanism of establishment of a segregation bias, which can be accounted for by simple physical arguments.

  5. College Daughters' Relationships with Their Fathers: A 15 Year Study

    ERIC Educational Resources Information Center

    Nielsen, Linda

    2007-01-01

    Data collected from 1990 until 2004 from 423 college women show that, although the majority felt they had a loving relationship with their fathers, the vast majority felt that the mother-daughter relationship was more communicative, more emotionally intimate, and more comfortable. Daughters and mothers knew one another better and were more…

  6. Childhood Stress, Behavioural Symptoms and Mother-Daughter Pubertal Development.

    ERIC Educational Resources Information Center

    Kim, Kenneth; Smith, Peter K.

    1998-01-01

    Daughter's early childhood stress, conflict in the family environment, childhood behavioral symptoms, early puberty, and early dating behavior are related to mothers' early menarche and sexual involvement by a retrospective self-report survey (21 mothers; 28 daughters). Intended as a test of Belsky's theory, alternative explanations for findings…

  7. Atmosphere purification of radon and radon daughter elements

    DOEpatents

    Stein, L.

    1973-12-11

    A method for purifying an atmosphere of radon and radon daughter elements which may be contained therein by contacting the atmosphere with a fluorinating solution, whereby the radon and radon daughters are oxidized to their respective fluorides is discussed. The fluorides dissolve in the fluorinating solutlon and are removed from the atmosphere, which may then be recirculated. (Official Gazette)

  8. The Maternal Gift: Mothers' Investment in Their Daughters' Higher Education

    ERIC Educational Resources Information Center

    Cooper, Linda

    2017-01-01

    This article explores the degree to which mothers participate in decisions surrounding their daughters' university choices in the English higher education sector, based on a gendered PhD study involving mother and adult daughter pairings in southern England. Examples are given of how extended middle-class mothering practices are enabling their…

  9. Incest and Its Meaning: The Perspectives of Fathers and Daughters.

    ERIC Educational Resources Information Center

    Phelan, Patricia

    1995-01-01

    Interviews with 40 fathers and stepfathers and 44 biologic daughters and stepdaughters involved in incestuous activity revealed their recollection of events, their thoughts, and interpretations. Fathers' thoughts were dominated by themes of sexual gratification, control, power, anger, and rights and responsibilities; daughters reported disbelief,…

  10. Bilateral familial Hirayama disease in a father and daughter

    PubMed Central

    Pandey, Sanjay; Jain, Shruti

    2016-01-01

    We are reporting a case of bilateral familial Hirayama disease where a father and daughter are the affected members of the family with the similar distribution of their weakness and wasting. To the best of our knowledge, bilateral familial Hirayama disease has not been described in father and daughter. PMID:27293344

  11. Adolescents with Nonresident Fathers: Are Daughters More Disadvantaged than Sons?

    ERIC Educational Resources Information Center

    Mitchell, Katherine Stamps; Booth, Alan; King, Valarie

    2009-01-01

    This study examined sons' and daughters' involvement with nonresident fathers and associated outcomes (N = 4,663). Results indicated that sons and daughters reported equal involvement with nonresident fathers on most measures of father investment, although sons reported more overnight visits, sports, and movies and feeling closer to their fathers…

  12. Fathers as Mentors to Daughters. Radcliffe Institute Working Paper.

    ERIC Educational Resources Information Center

    Kahn, Diana Grossman

    Research literature on female achievers has consistently shown that the encouragement of fathers who act as mentors to their daughters is particularly important. To examine the behavior of fathers with their daughters, female junior and senior college students (N=114) completed an 11-page questionnaire about their personal background. Some of the…

  13. Posttraumatic Stress in Women with Breast Cancer and Their Daughters.

    ERIC Educational Resources Information Center

    Boyer, Bret A.; Bubel, Denise; Jacobs, Sheri R.; Knolls, Michelle L.; Harwell, Valerie D.; Goscicka, Magdalena; Keegan, Anne

    2002-01-01

    Twenty-one percent of the surveyed women (N=133) with cancer and 13% of their daughters (N=64) reported symptoms of posttraumatic stress disorder (PTSD). Prevalence of PTSD symptoms in daughters appears comparable to women with breast cancer. Discusses intergenerational patterns in reaction to breast cancer. (JDM)

  14. Impact of Elderly Mother's Death on Middle Age Daughters.

    ERIC Educational Resources Information Center

    Moss, Miriam S.; And Others

    1993-01-01

    Examined middle aged daughters' (n=107) responses to death of their mother. In first six months of bereavement, many daughters experienced themes of holding on and letting go. Depression, grief, somatic reactions, impact on sense of self, acceptance of death, and ways in which ties with mother endure were differentially associated with…

  15. Aggregation of red blood cells: From rouleaux to clot formation

    NASA Astrophysics Data System (ADS)

    Wagner, Christian; Steffen, Patrick; Svetina, Saša

    2013-06-01

    Red blood cells are known to form aggregates in the form of rouleaux. This aggregation process is believed to be reversible, but there is still no full understanding on the adhesion mechanism. There are at least two competing models, based either on bridging or on depletion. We review recent experimental results on the single cell level and theoretical analyses of the depletion model and of the influence of the cell shape on the adhesion strength. Another important aggregation mechanism is caused by activation of platelets. This leads to clot formation which is life-saving in the case of wound healing, but also a major cause of death in the case of a thrombus induced stroke. We review historical and recent results on the participation of red blood cells in clot formation.

  16. Human papillomavirus 16 E5 induces bi-nucleated cell formation by cell-cell fusion

    SciTech Connect

    Hu Lulin; Plafker, Kendra; Vorozhko, Valeriya; Zuna, Rosemary E.; Hanigan, Marie H.; Gorbsky, Gary J.; Plafker, Scott M.; Angeletti, Peter C.; Ceresa, Brian P.

    2009-02-05

    Human papillomaviruses (HPV) 16 is a DNA virus encoding three oncogenes - E5, E6, and E7. The E6 and E7 proteins have well-established roles as inhibitors of tumor suppression, but the contribution of E5 to malignant transformation is controversial. Using spontaneously immortalized human keratinocytes (HaCaT cells), we demonstrate that expression of HPV16 E5 is necessary and sufficient for the formation of bi-nucleated cells, a common characteristic of precancerous cervical lesions. Expression of E5 from non-carcinogenic HPV6b does not produce bi-nucleate cells. Video microscopy and biochemical analyses reveal that bi-nucleates arise through cell-cell fusion. Although most E5-induced bi-nucleates fail to propagate, co-expression of HPV16 E6/E7 enhances the proliferation of these cells. Expression of HPV16 E6/E7 also increases bi-nucleated cell colony formation. These findings identify a new role for HPV16 E5 and support a model in which complementary roles of the HPV16 oncogenes lead to the induction of carcinogenesis.

  17. In vitro myelin formation using embryonic stem cells

    PubMed Central

    Kerman, Bilal E.; Kim, Hyung Joon; Padmanabhan, Krishnan; Mei, Arianna; Georges, Shereen; Joens, Matthew S.; Fitzpatrick, James A. J.; Jappelli, Roberto; Chandross, Karen J.; August, Paul; Gage, Fred H.

    2015-01-01

    Myelination in the central nervous system is the process by which oligodendrocytes form myelin sheaths around the axons of neurons. Myelination enables neurons to transmit information more quickly and more efficiently and allows for more complex brain functions; yet, remarkably, the underlying mechanism by which myelination occurs is still not fully understood. A reliable in vitro assay is essential to dissect oligodendrocyte and myelin biology. Hence, we developed a protocol to generate myelinating oligodendrocytes from mouse embryonic stem cells and established a myelin formation assay with embryonic stem cell-derived neurons in microfluidic devices. Myelin formation was quantified using a custom semi-automated method that is suitable for larger scale analysis. Finally, early myelination was followed in real time over several days and the results have led us to propose a new model for myelin formation. PMID:26015546

  18. Open-cell cloud formation over the Bahamas

    NASA Technical Reports Server (NTRS)

    2002-01-01

    What atmospheric scientists refer to as open cell cloud formation is a regular occurrence on the back side of a low-pressure system or cyclone in the mid-latitudes. In the Northern Hemisphere, a low-pressure system will draw in surrounding air and spin it counterclockwise. That means that on the back side of the low-pressure center, cold air will be drawn in from the north, and on the front side, warm air will be drawn up from latitudes closer to the equator. This movement of an air mass is called advection, and when cold air advection occurs over warmer waters, open cell cloud formations often result. This MODIS image shows open cell cloud formation over the Atlantic Ocean off the southeast coast of the United States on February 19, 2002. This particular formation is the result of a low-pressure system sitting out in the North Atlantic Ocean a few hundred miles east of Massachusetts. (The low can be seen as the comma-shaped figure in the GOES-8 Infrared image from February 19, 2002.) Cold air is being drawn down from the north on the western side of the low and the open cell cumulus clouds begin to form as the cold air passes over the warmer Caribbean waters. For another look at the scene, check out the MODIS Direct Broadcast Image from the University of Wisconsin. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  19. Solvent effect on columnar formation in solar-cell geometry

    NASA Astrophysics Data System (ADS)

    Park, J. H.; Sosa-Vargas, L.; Takanishi, Y.; Kim, K. H.; Kim, Y. S.; Park, Y. W.; Yamamoto, J.; Labardi, M.; Lagerwall, J. P. F.; Shimizu, Y.; Scalia, G.

    2016-03-01

    The efficiency of the conduction of photocurrent in discotic liquid crystals is known to depend on the quality of the columnar organization. Solvents have shown to be able to influence the formation of wire structures on substrates promoting very long and ordered wired formations or bulkier structures depending on the affinity of the solvent with parts of the molecular structure of discotics. Here we present a study on the effect of solvents when the liquid crystal is confined between two substrates with the columns running perpendicular to them, geometry used in solar cells. We focused on toluene and dodecane, solvents that have shown to promote on substrates the formation of aligned and long nanowires and bulk large and isolated fibers, respectively. The phase transition behavior indicates that toluene does not interfere with the columnar formation while dodecane strongly influence increasing the disorder in the structure.

  20. Synapse formation during embryogenesis on ganglion cells lacking a periphery

    PubMed Central

    Landmesser, Lynn; Pilar, G.

    1974-01-01

    1. The development of transmission was studied in chick ciliary ganglia that had been deprived of their periphery during early embryonic development. 2. Peripherally deprived neurones in the ganglion differentiate in normal numbers and send functional axons into the post-ganglionic nerve. 3. Ganglion cells lacking a periphery follow the normal developmental sequence sending out transient dendrites at the time ganglion cell synapses are formed, and later retracting them when calyces appear. 4. Synapses, which appear functionally and ultrastructurally normal, form on all ganglion cells at the normal time and transmission is normal until Stage 34. Therefore information from the periphery is not required for ganglion cell synapse formation per se. 5. From Stages 35 to 38 most cells die, so that only 8% of the original number of cells remain in the operated ganglion. Transmission fails in many cells during this same time, but precedes cell loss by only a short time, so that deafferentation probably does not contribute substantially to cell death. 6. Both ciliary and choroid cells achieve full cytologic differentiation and are distinct from each other, indicating that the periphery is not required for the elaboration of the distinctive characteristics of these cells. Presynaptic fibres also differentiate into typical bouton as well as calyciform endings. Therefore, the type of preganglionic ending does not depend on ganglion cells establishing proper peripheral contacts. 7. It has not been possible to ascertain whether ganglion cell specificity is affected by the periphery. 8. Peripheral removal affects ganglion cell migration, so that two ganglia are formed. Approximately half of the cells migrate into the remnant optic cup forming a second misplaced ganglion. Ciliary and choroid cells occur in both ganglia and these cells go through the typical sequence of events described above. ImagesPlate 1Plate 2Plate 3 PMID:4373567

  1. Multiwell cell culture plate format with integrated microfluidic perfusion system

    NASA Astrophysics Data System (ADS)

    Domansky, Karel; Inman, Walker; Serdy, Jim; Griffith, Linda G.

    2006-01-01

    A new cell culture analog has been developed. It is based on the standard multiwell cell culture plate format but it provides perfused three-dimensional cell culture capability. The new capability is achieved by integrating microfluidic valves and pumps into the plate. The system provides a means to conduct high throughput assays for target validation and predictive toxicology in the drug discovery and development process. It can be also used for evaluation of long-term exposure to drugs or environmental agents or as a model to study viral hepatitis, cancer metastasis, and other diseases and pathological conditions.

  2. Polydatin Inhibits Formation of Macrophage-Derived Foam Cells

    PubMed Central

    Wu, Min; Liu, Meixia; Guo, Gang; Zhang, Wengao; Liu, Longtao

    2015-01-01

    Rhizoma Polygoni Cuspidati, a Chinese herbal medicine, has been widely used in traditional Chinese medicine for a long time. Polydatin, one of the major active ingredients in Rhizoma Polygoni Cuspidati, has been recently shown to possess extensive cardiovascular pharmacological activities. In present study, we examined the effects of Polydatin on the formation of peritoneal macrophage-derived foam cells in Apolipoprotein E gene knockout mice (ApoE−/−) and explored the potential underlying mechanisms. Peritoneal macrophages were collected from ApoE−/− mice and cultured in vitro. These cells sequentially were divided into four groups: Control group, Model group, Lovastatin group, and Polydatin group. Our results demonstrated that Polydatin significantly inhibits the formation of foam cells derived from peritoneal macrophages. Further studies indicated that Polydatin regulates the metabolism of intracellular lipid and possesses anti-inflammatory effects, which may be regulated through the PPAR-γ signaling pathways. PMID:26557864

  3. Characterization of Commercial Li-ion Cells in Pouch Format

    NASA Technical Reports Server (NTRS)

    Jeevarajan, Judith

    2014-01-01

    The li-ion pouch design cells exhibit similar behavior under off-nominal conditions as those in metal cans that do not have the internal safety devices. Safety should be well characterized before batteries are designed. Some of the li-ion pouch cell designs studied in this program reacted most violently to overcharge conditions at the medium rates but were tolerant to overcharge at very low rates. Some pouch cell designs have higher tolerance to vacuum exposures than some others. A comparison of the pouch material itself does not show a correlation between this tolerance and the number of layers or composition of the pouch indicating that this is a property of the electrode stack design inside the pouch. Reduced pressure (8 to 10 psi) test environments show that the extent of capacity degradation under reduced pressure environments is much less than that observed under vacuum conditions. Lithium-ion Pouch format cells are not necessarily true polymer cells.

  4. Graphene-Induced Pore Formation on Cell Membranes

    NASA Astrophysics Data System (ADS)

    Duan, Guangxin; Zhang, Yuanzhao; Luan, Binquan; Weber, Jeffrey K.; Zhou, Royce W.; Yang, Zaixing; Zhao, Lin; Xu, Jiaying; Luo, Judong; Zhou, Ruhong

    2017-02-01

    Examining interactions between nanomaterials and cell membranes can expose underlying mechanisms of nanomaterial cytotoxicity and guide the design of safer nanomedical technologies. Recently, graphene has been shown to exhibit potential toxicity to cells; however, the molecular processes driving its lethal properties have yet to be fully characterized. We here demonstrate that graphene nanosheets (both pristine and oxidized) can produce holes (pores) in the membranes of A549 and Raw264.7 cells, substantially reducing cell viability. Electron micrographs offer clear evidence of pores created on cell membranes. Our molecular dynamics simulations reveal that multiple graphene nanosheets can cooperate to extract large numbers of phospholipids from the membrane bilayer. Strong dispersion interactions between graphene and lipid-tail carbons result in greatly depleted lipid density within confined regions of the membrane, ultimately leading to the formation of water-permeable pores. This cooperative lipid extraction mechanism for membrane perforation represents another distinct process that contributes to the molecular basis of graphene cytotoxicity.

  5. Stromal cells in chronic inflammation and tertiary lymphoid organ formation.

    PubMed

    Buckley, Christopher D; Barone, Francesca; Nayar, Saba; Bénézech, Cecile; Caamaño, Jorge

    2015-01-01

    Inflammation is an unstable state. It either resolves or persists. Why inflammation persists and the factors that define tissue tropism remain obscure. Increasing evidence suggests that tissue-resident stromal cells not only provide positional memory but also actively regulate the differential accumulation of inflammatory cells within inflamed tissues. Furthermore, at many sites of chronic inflammation, structures that mimic secondary lymphoid tissues are observed, suggesting that chronic inflammation and lymphoid tissue formation share common activation programs. Similarly, blood and lymphatic endothelial cells contribute to tissue homeostasis and disease persistence in chronic inflammation. This review highlights our increasing understanding of the role of stromal cells in inflammation and summarizes the novel immunological role that stromal cells exert in the persistence of inflammatory diseases.

  6. The Role of Runx1 in Embryonic Blood Cell Formation.

    PubMed

    Yzaguirre, Amanda D; de Bruijn, Marella F T R; Speck, Nancy A

    2017-01-01

    The de novo generation of hematopoietic stem and progenitor cells (HSPC) occurs solely during embryogenesis from a population of epithelial cells called hemogenic endothelium (HE). During midgestation HE cells in multiple intra- and extraembryonic vascular beds leave the vessel wall as they transition into HSPCs in a process termed the endothelial to hematopoietic transition (EHT). Runx1 expression in HE cells orchestrates the transcriptional switch necessary for the transdifferentiation of endothelial cells into functional HSPCs. Runx1 is widely considered the master regulator of developmental hematopoiesis because it plays an essential function during specification of the hematopoietic lineage during embryogenesis. Here we review the role of Runx1 in embryonic HSPC formation, with a particular focus on its role in hemogenic endothelium.

  7. Induction of platelet formation from megakaryocytoid cells by nitric oxide.

    PubMed

    Battinelli, E; Willoughby, S R; Foxall, T; Valeri, C R; Loscalzo, J

    2001-12-04

    Although the growth factors that regulate megakaryocytopoiesis are well known, the molecular determinants of platelet formation from mature megakaryocytes remain poorly understood. Morphological changes in megakaryocytes associated with platelet formation and removal of senescent megakaryocytes are suggestive of an apoptotic process. Previously, we have established that nitric oxide (NO) can induce apoptosis in megakaryocytoid cell lines. To determine whether there is an association between NO-induced apoptosis and platelet production, we exposed Meg-01 cells to S-nitrosoglutathione (GSNO) with or without thrombopoeitin (TPO) pretreatment and used flow cytometry and electron microscopy to assess platelet-sized particle formation. Meg-01 cells treated with TPO alone produced few platelet-sized particles (<3% of total counts), whereas treatment with GSNO alone produced a significant percentage of platelet-sized particles (22 +/- 4% of total counts); when combined with TPO pretreatment, however, GSNO led to a marked increase in platelet-sized particle production (48 +/- 3% of total counts). Electron microscopy confirmed that Meg-01 cells treated with TPO and GSNO yielded platelet-sized particles with morphological features specific for platelet forms. The platelet-sized particle population appears to be functional, because addition of calcium, fibrinogen, and thrombin receptor-activating peptide led to aggregation. These results demonstrate that NO facilitates platelet production, thereby establishing the essential role of NO in megakaryocyte development and thrombopoiesis.

  8. ERBB3 is required for metastasis formation of melanoma cells

    PubMed Central

    Tiwary, S; Preziosi, M; Rothberg, P G; Zeitouni, N; Corson, N; Xu, L

    2014-01-01

    Melanoma is curable when it is at an early phase but is lethal once it becomes metastatic. The recent development of BRAFV600E inhibitors (BIs) showed great promise in treating metastatic melanoma, but resistance developed quickly in the treated patients, and these inhibitors are not effective on melanomas that express wild-type BRAF. Alternative therapeutic strategies for metastatic melanoma are urgently needed. Here we report that ERBB3, a member of the epidermal growth factor receptor family, is required for the formation of lung metastasis from both the BI-sensitive melanoma cell line, MA-2, and the BI-resistant melanoma cell line, 451Lu-R. Further analyses revealed that ERBB3 does not affect the initial seeding of melanoma cells in lung but is required for their further development into overt metastases, indicating that ERBB3 might be essential for the survival of melanoma cells after they reach the lung. Consistent with this, the ERBB3 ligand, NRG1, is highly expressed in mouse lungs and induces ERBB3-depdnent phosphorylation of AKT in both MA-2 and 451Lu-R cells in vitro. These findings suggest that ERBB3 may serve as a target for treating metastatic melanomas that are resistant to BIs. In support of this, administration of the pan-ERBB inhibitor, canertinib, significantly suppresses the metastasis formation of BI-resistant melanoma cell lines. PMID:25000258

  9. A Jupiter Orbiter mother/daughter spacecraft concept

    NASA Technical Reports Server (NTRS)

    Duxbury, J. H.

    1975-01-01

    The feasibility of a tandem launch of a mother/daughter spacecraft pair with a single launch vehicle for a 1981 Mariner Jupiter Orbiter mission is described. The mother is a close derivative of the three-axis stabilized Mariner Jupiter Saturn 1977 spacecraft with the addition of a Viking-type propulsion module for orbit capture; it concentrates on the planetology and satellite science objectives. The daughter is a small, simple spin-stabilized spacecraft taking advantage of the mother's transit and delivery capabilities; it obtains in-situ measurements of the surrounding planetary environment. A conceptual design of the daughter spacecraft is presented.

  10. Radon daughter considerations in a nuclear power plant

    SciTech Connect

    VanderMey, T.J.

    1987-07-01

    A boiling water reactor in the start-up phase experienced a significant number of personnel contamination monitor alarms caused by radon daughter plateout on hard hats, clothing, and shoes. Alarm frequencies were compared to environmental conditions and ventilation system operations to determine the effects of various factors on radon plateout. High normal ventilation, radon daughter concentrations in the plant were found to be similar to outdoor concentrations, and alarm frequencies were inversely related to relative humidity. When ventilation systems were shutdown, indoor radon levels and personnel contamination monitor alarm rates increased significantly. In this paper some suggestions for accounting for radon daughter contamination in monitoring and training programs are presented.

  11. A Jupiter Orbiter mother/daughter spacecraft concept

    NASA Technical Reports Server (NTRS)

    Duxbury, J. H.

    1975-01-01

    The feasibility of a tandem launch of a mother/daughter spacecraft pair with a single launch vehicle for a 1981 Mariner Jupiter Orbiter mission is described. The mother is a close derivative of the three-axis stabilized Mariner Jupiter Saturn 1977 spacecraft with the addition of a Viking-type propulsion module for orbit capture; it concentrates on the planetology and satellite science objectives. The daughter is a small, simple spin-stabilized spacecraft taking advantage of the mother's transit and delivery capabilities; it obtains in-situ measurements of the surrounding planetary environment. A conceptual design of the daughter spacecraft is presented.

  12. Quercetin suppresses intracellular ROS formation, MMP activation, and cell motility in human fibrosarcoma cells.

    PubMed

    Lee, Dong Eun; Chung, Min-Yu; Lim, Tae Gyu; Huh, Won Bum; Lee, Hyong Joo; Lee, Ki Won

    2013-09-01

    Cell metastasis is a major cause of death from cancer and can arise from excessive levels of oxidative stress. The objective of this study was to investigate whether the natural flavonoid quercetin can inhibit matrix metalloproteinase (MMP)-2 and -9 activities through the attenuation of reactive oxygen species (ROS) formation, an event expected to lead to the inhibition of cell motility. To induce sustained ROS formation, cells were treated with phenazine methosulfate (PMS; 1 μM). Noncytotoxic concentrations of quercetin inhibited PMS-induced increases in cell motility in HT1080 human fibrosarcoma (HT1080) cells. While nearly 100% of cells were observed to migrate after 24 h of PMS treatment, quercetin significantly (P < 0.01) suppressed this effect. We also found that quercetin, up to 10 μg/mL, attenuated PMS-induced MMP-2 activation. We then investigated whether the decreased levels of MMP-2 activation could be attributable to lower levels of ROS formation by quercetin. We found that quercetin treatments significantly attenuated PMS-induced ROS formation (P < 0.01) and resulted in decreased cell motility associated with a reduction in MMP-2 and -9 activitiy in HT1080 cells, even in the absence of PMS treatment. Collectively, these results suggest that quercetin inhibits cell motility via the inhibition of MMP activation in HT1080 cells in the presence and absence of PMS. This is likely to be a result of the suppression of intracellular ROS formation by quercetin. © 2013 Institute of Food Technologists®

  13. Spectroscopy of 253No and its daughters

    NASA Astrophysics Data System (ADS)

    Lopez-Martens, A.; Wiborg-Hagen, T.; Hauschild, K.; Chelnokov, M. L.; Chepigin, V. I.; Curien, D.; Dorvaux, O.; Drafta, G.; Gall, B.; Görgen, A.; Guttormsen, M.; Isaev, A. V.; Izosimov, I. N.; Kabachenko, A. P.; Katrasev, D. E.; Kutsarova, T.; Kuznetsov, A. N.; Larsen, A. C.; Malyshev, O. N.; Minkova, A.; Mullins, S.; Nyhus, H. T.; Pantelica, D.; Piot, J.; Popeko, A. G.; Saro, S.; Scintee, N.; Siem, S.; Syed, N. U. H.; Sokol, E. A.; Svirikhin, A. I.; Yeremin, A. V.

    2011-02-01

    New high-statistics data have been obtained on the decay properties of 253No and its daughters using the reaction 207Pb(48Ca, 2n)253No. This was made possible thanks to an improved transmission of fusion-evaporation residues through the VASSILISSA recoil separator and an increased efficiency of the GABRIELA detector setup. The decay schemes of 253No and 249Fm have been revisited. The known level scheme of 249Fm has been confirmed, including a new level at 669 keV excitation energy. The observation of L X-rays in coincidence with the α decay of 249Fm gives additional support to the ground-state configuration of 1/2[631] instead of 5/2[622] for 245Cf. In both 249Fm and 245Cf, the interpretation of the data has been checked by comparing experimental α-particle and γ-ray spectra with realistic simulations of the decay cascades and of the interaction of particles and photons in the detectors of GABRIELA. The population of a 0.7 ms isomeric state attributed to 253No is confirmed by an α-tagged calorimetric measurement and the corresponding γ and electron decay spectra are presented. Possible evidence for more than one isomer is given and a tentative partial decay scheme is discussed in the light of the available experimental data, systematics and theoretical expectations.

  14. Lawson Wilkins: recollections by his daughter

    PubMed Central

    2014-01-01

    Lawson Wilkins is well known as the “father” of the field of pediatric endocrinology, and his scientific accomplishments and legacy are thoroughly documented in this edition and elsewhere. Less well known, though, is what the man himself was like. Here, his daughter, Elizabeth McMaster, recalls the personal side of Dr. Wilkins including his upbringing as the son of a prominent Baltimore doctor, his medical education, establishment of a successful pediatric practice, and eventually the founding of the endocrine clinic at Johns Hopkins. Interwoven with anecdotes and reminiscences, this account provides a vivid sense of Wilkins’ personality and life, from his boisterous nature and devotion to his family and career, to the tragic personal losses he endured. He was a man who threw himself fully into everything he did, whether it was making his own liqueur during Prohibition, collecting specimens from abnormally large circus performers as part of his earliest endocrine research, arranging raucous, impromptu singing parties, sailing the Chesapeake with friends, writing a definitive textbook of Pediatric Endocrinology, training a legion of fellows, or the pioneering work for which he is still known today. PMID:25024712

  15. Activity ratios of thorium daughters in vivo

    SciTech Connect

    Toohey, R.E.; Rundo, J.; Sha, J.Y.; Essling, M.A.; Pedersen, J.C.; Slane, J.M.

    1984-01-01

    A computerized method of least squares has been used to analyze the /sup 228/Ac and /sup 212/Pb-/sup 212/Bi and daughter ..gamma..-ray spectra obtained in vivo from 133 former workers at a thorium refinery. In addition, the exhalation rate of /sup 220/Rn was determined for each subject and expressed as pCi of emanating /sup 224/Ra. This value was added to the /sup 212/Pb value determined from the ..gamma..-ray measurements to obtain the total /sup 224/Ra present, and the ratio of /sup 224/Ra to /sup 228/Ac was calculated. Values of the ratio ranged from 0.52 +- 0.32 to 2.1 +- 1.7, with a weighted mean of 0.92 +- 0.17. However, it appears that the ratio observed in a given case is characteristic for that case alone; the computed mean value may not be meaningful. The least squares fitting procedure and the overall calibration of the counting system were validated by measurements of /sup 224/Ra in the lungs of one subject postmortem, compared with results obtained from the same subject in vivo. 6 references, 5 figures.

  16. Effect of supercooling and cell volume on intracellular ice formation.

    PubMed

    Prickett, Richelle C; Marquez-Curtis, Leah A; Elliott, Janet A W; McGann, Locksley E

    2015-04-01

    Intracellular ice formation (IIF) has been linked to death of cells cryopreserved in suspension. It has been assumed that cells can be supercooled by 2 to 10°C before IIF occurs, but measurements of the degree of supercooling that cells can tolerate are often confounded by changing extracellular temperature and solutions of different osmolality (which affect the cell volume). The purpose of this study was to examine how the incidence of IIF in the absence of cryoprotectants is affected by the degree of supercooling and cell volume. Human umbilical vein endothelial cells were suspended in isotonic (300 mOsm) and hypertonic (∼600 to 700 mOsm) solutions and exposed to supercooling ranging from 2 to 10°C before extracellular ice was nucleated. The number of cells undergoing IIF was examined in a cryostage (based on the darkening of cells upon intracellular freezing ("flashing")) as a function of the degree of supercooling, and cell survival post-thaw was assessed using a membrane integrity assay. We found that while the incidence of IIF increased with supercooling in both isotonic and hypertonic solutions, it was higher in the isotonic solution at any given degree of supercooling. Since cells in hypertonic solution were shrunken due to water efflux, we hypothesized that the difference in IIF behavior could be attributed to the decreased volume of cells in the hypertonic solution. Our results confirm that cells with a smaller diameter before extracellular ice nucleation have a decreased probability of IIF and suggest that cell volume could play a more significant role in the incidence of IIF than the extracellular ice nucleation temperature. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Aroma formation by immobilized yeast cells in fermentation processes.

    PubMed

    Nedović, V; Gibson, B; Mantzouridou, T F; Bugarski, B; Djordjević, V; Kalušević, A; Paraskevopoulou, A; Sandell, M; Šmogrovičová, D; Yilmaztekin, M

    2015-01-01

    Immobilized cell technology has shown a significant promotional effect on the fermentation of alcoholic beverages such as beer, wine and cider. However, genetic, morphological and physiological alterations occurring in immobilized yeast cells impact on aroma formation during fermentation processes. The focus of this review is exploitation of existing knowledge on the biochemistry and the biological role of flavour production in yeast for the biotechnological production of aroma compounds of industrial importance, by means of immobilized yeast. Various types of carrier materials and immobilization methods proposed for application in beer, wine, fruit wine, cider and mead production are presented. Engineering aspects with special emphasis on immobilized cell bioreactor design, operation and scale-up potential are also discussed. Ultimately, examples of products with improved quality properties within the alcoholic beverages are addressed, together with identification and description of the future perspectives and scope for cell immobilization in fermentation processes. Copyright © 2014 John Wiley & Sons, Ltd.

  18. A hydrodynamic microchip for formation of continuous cell chains

    NASA Astrophysics Data System (ADS)

    Khoshmanesh, Khashayar; Zhang, Wei; Tang, Shi-Yang; Nasabi, Mahyar; Soffe, Rebecca; Tovar-Lopez, Francisco J.; Rajadas, Jayakumar; Mitchell, Arnan

    2014-05-01

    Here, we demonstrate the unique features of a hydrodynamic based microchip for creating continuous chains of model yeast cells. The system consists of a disk shaped microfluidic structure, containing narrow orifices that connect the main channel to an array of spoke channels. Negative pressure provided by a syringe pump draws fluid from the main channel through the narrow orifices. After cleaning process, a thin layer of water is left between the glass substrate and the polydimethylsiloxane microchip, enabling leakage beneath the channel walls. A mechanical clamp is used to adjust the operation of the microchip. Relaxing the clamp allows leakage of liquid beneath the walls in a controllable fashion, leading to formation of a long cell chain evenly distributed along the channel wall. The unique features of the microchip are demonstrated by creating long chains of yeast cells and model 15 μm polystyrene particles along the side wall and analysing the hydrogen peroxide induced death of patterned cells.

  19. Exocytosis of macrophage lysosomes leads to digestion of apoptotic adipocytes and foam cell formation[S

    PubMed Central

    Haka, Abigail S.; Barbosa-Lorenzi, Valéria C.; Lee, Hyuek Jong; Falcone, Domenick J.; Hudis, Clifford A.; Dannenberg, Andrew J.

    2016-01-01

    Many types of apoptotic cells are phagocytosed and digested by macrophages. Adipocytes can be hundreds of times larger than macrophages, so they are too large to be digested by conventional phagocytic processes. The nature of the interaction between macrophages and apoptotic adipocytes has not been studied in detail. We describe a cellular process, termed exophagy, that is important for macrophage clearance of dead adipocytes and adipose tissue homeostasis. Using mouse models of obesity, human tissue, and a cell culture model, we show that macrophages form hydrolytic extracellular compartments at points of contact with dead adipocytes using local actin polymerization. These compartments are acidic and contain lysosomal enzymes delivered by exocytosis. Uptake and complete degradation of adipocyte fragments, which are released by extracellular hydrolysis, leads to macrophage foam cell formation. Exophagy-mediated foam cell formation is a highly efficient means by which macrophages internalize large amounts of lipid, which may ultimately overwhelm the metabolic capacity of the macrophage. This process provides a mechanism for degradation of objects, such as dead adipocytes, that are too large to be phagocytosed by macrophages. PMID:27044658

  20. Formation and specification of a Drosophila dopaminergic precursor cell.

    PubMed

    Watson, Joseph D; Crews, Stephen T

    2012-09-01

    Dopaminergic neurons play important roles in animal behavior, including motivation, reward and locomotion. The Drosophila dopaminergic H-cell interneuron is an attractive system for studying the genetics of neural development because analysis is focused on a single neuronal cell type. Here we provide a mechanistic understanding of how MP3, the precursor to the H-cell, forms and acquires its identity. We show that the gooseberry/gooseberry-neuro (gsb/gsb-n) transcription factor genes act to specify MP3 cell fate. It is proposed that single-minded commits neuroectodermal cells to a midline fate, followed by a series of signaling events that result in the formation of a single gsb(+)/gsb-n(+) MP3 cell per segment. The wingless signaling pathway establishes a midline anterior domain by activating expression of the forkhead transcription factors sloppy paired 1 and sloppy paired 2. This is followed by hedgehog signaling that activates gsb/gsb-n expression in a subgroup of anterior cells. Finally, Notch signaling results in the selection of a single MP3, with the remaining cells becoming midline glia. In MP3, gsb/gsb-n direct H-cell development, in large part by activating expression of the lethal of scute and tailup H-cell regulatory genes. Thus, a series of signaling and transcriptional events result in the specification of a unique dopaminergic precursor cell. Additional genetic experiments indicate that the molecular mechanisms that govern MP3/H-cell development might also direct the development of non-midline dopaminergic neurons.

  1. Formation and specification of a Drosophila dopaminergic precursor cell

    PubMed Central

    Watson, Joseph D.; Crews, Stephen T.

    2012-01-01

    Dopaminergic neurons play important roles in animal behavior, including motivation, reward and locomotion. The Drosophila dopaminergic H-cell interneuron is an attractive system for studying the genetics of neural development because analysis is focused on a single neuronal cell type. Here we provide a mechanistic understanding of how MP3, the precursor to the H-cell, forms and acquires its identity. We show that the gooseberry/gooseberry-neuro (gsb/gsb-n) transcription factor genes act to specify MP3 cell fate. It is proposed that single-minded commits neuroectodermal cells to a midline fate, followed by a series of signaling events that result in the formation of a single gsb+/gsb-n+ MP3 cell per segment. The wingless signaling pathway establishes a midline anterior domain by activating expression of the forkhead transcription factors sloppy paired 1 and sloppy paired 2. This is followed by hedgehog signaling that activates gsb/gsb-n expression in a subgroup of anterior cells. Finally, Notch signaling results in the selection of a single MP3, with the remaining cells becoming midline glia. In MP3, gsb/gsb-n direct H-cell development, in large part by activating expression of the lethal of scute and tailup H-cell regulatory genes. Thus, a series of signaling and transcriptional events result in the specification of a unique dopaminergic precursor cell. Additional genetic experiments indicate that the molecular mechanisms that govern MP3/H-cell development might also direct the development of non-midline dopaminergic neurons. PMID:22874915

  2. Pyrintegrin Induces Soft Tissue Formation by Transplanted or Endogenous Cells

    PubMed Central

    Shah, Bhranti S.; Chen, Mo; Suzuki, Takahiro; Embree, Mildred; Kong, Kimi; Lee, Chang H.; He, Ling; Xiang, Lusai; Ahn, Jeffrey A.; Ding, Sheng; Mao, Jeremy J.

    2017-01-01

    Focal adipose deficiency, such as lipoatrophy, lumpectomy or facial trauma, is a formidable challenge in reconstructive medicine, and yet scarcely investigated in experimental studies. Here, we report that Pyrintegrin (Ptn), a 2,4-disubstituted pyrimidine known to promote embryonic stem cells survival, is robustly adipogenic and induces postnatal adipose tissue formation in vivo of transplanted adipose stem/progenitor cells (ASCs) and recruited endogenous cells. In vitro, Ptn stimulated human adipose tissue derived ASCs to differentiate into lipid-laden adipocytes by upregulating peroxisome proliferator-activated receptor (PPARγ) and CCAAT/enhancer-binding protein-α (C/EBPα), with differentiated cells increasingly secreting adiponectin, leptin, glycerol and total triglycerides. Ptn-primed human ASCs seeded in 3D-bioprinted biomaterial scaffolds yielded newly formed adipose tissue that expressed human PPARγ, when transplanted into the dorsum of athymic mice. Remarkably, Ptn-adsorbed 3D scaffolds implanted in the inguinal fat pad had enhanced adipose tissue formation, suggesting Ptn’s ability to induce in situ adipogenesis of endogenous cells. Ptn promoted adipogenesis by upregulating PPARγ and C/EBPα not only in adipogenesis induction medium, but also in chemically defined medium specifically for osteogenesis, and concurrently attenuated Runx2 and Osx via BMP-mediated SMAD1/5 phosphorylation. These findings suggest Ptn’s novel role as an adipogenesis inducer with a therapeutic potential in soft tissue reconstruction and augmentation. PMID:28128224

  3. Blockade of mast cell activation reduces cutaneous scar formation.

    PubMed

    Chen, Lin; Schrementi, Megan E; Ranzer, Matthew J; Wilgus, Traci A; DiPietro, Luisa A

    2014-01-01

    Damage to the skin initiates a cascade of well-orchestrated events that ultimately leads to repair of the wound. The inflammatory response is key to wound healing both through preventing infection and stimulating proliferation and remodeling of the skin. Mast cells within the tissue are one of the first immune cells to respond to trauma, and upon activation they release pro-inflammatory molecules to initiate recruitment of leukocytes and promote a vascular response in the tissue. Additionally, mast cells stimulate collagen synthesis by dermal fibroblasts, suggesting they may also influence scar formation. To examine the contribution of mast cells in tissue repair, we determined the effects the mast cell inhibitor, disodium cromoglycate (DSCG), on several parameters of dermal repair including, inflammation, re-epithelialization, collagen fiber organization, collagen ultrastructure, scar width and wound breaking strength. Mice treated with DSCG had significantly reduced levels of the inflammatory cytokines IL-1α, IL-1β, and CXCL1. Although DSCG treatment reduced the production of inflammatory mediators, the rate of re-epithelialization was not affected. Compared to control, inhibition of mast cell activity caused a significant decrease in scar width along with accelerated collagen re-organization. Despite the reduced scar width, DSCG treatment did not affect the breaking strength of the healed tissue. Tryptase β1 exclusively produced by mast cells was found to increase significantly in the course of wound healing. However, DSCG treatment did not change its level in the wounds. These results indicate that blockade of mast cell activation reduces scar formation and inflammation without further weakening the healed wound.

  4. Blockade of Mast Cell Activation Reduces Cutaneous Scar Formation

    PubMed Central

    Ranzer, Matthew J.; Wilgus, Traci A.; DiPietro, Luisa A.

    2014-01-01

    Damage to the skin initiates a cascade of well-orchestrated events that ultimately leads to repair of the wound. The inflammatory response is key to wound healing both through preventing infection and stimulating proliferation and remodeling of the skin. Mast cells within the tissue are one of the first immune cells to respond to trauma, and upon activation they release pro-inflammatory molecules to initiate recruitment of leukocytes and promote a vascular response in the tissue. Additionally, mast cells stimulate collagen synthesis by dermal fibroblasts, suggesting they may also influence scar formation. To examine the contribution of mast cells in tissue repair, we determined the effects the mast cell inhibitor, disodium cromoglycate (DSCG), on several parameters of dermal repair including, inflammation, re-epithelialization, collagen fiber organization, collagen ultrastructure, scar width and wound breaking strength. Mice treated with DSCG had significantly reduced levels of the inflammatory cytokines IL-1α, IL-1β, and CXCL1. Although DSCG treatment reduced the production of inflammatory mediators, the rate of re-epithelialization was not affected. Compared to control, inhibition of mast cell activity caused a significant decrease in scar width along with accelerated collagen re-organization. Despite the reduced scar width, DSCG treatment did not affect the breaking strength of the healed tissue. Tryptase β1 exclusively produced by mast cells was found to increase significantly in the course of wound healing. However, DSCG treatment did not change its level in the wounds. These results indicate that blockade of mast cell activation reduces scar formation and inflammation without further weakening the healed wound. PMID:24465509

  5. Mast cell mediators and peritoneal adhesion formation in the rat.

    PubMed

    Langer, J C; Liebman, S M; Monk, P K; Pelletier, G J

    1995-09-01

    We have previously shown that mast cell stabilization attenuates peritoneal adhesion formation in the rat. The present study investigated the mechanism of this protection. Adhesions were created in weanling rats using cecal scraping and application of 95% ethanol. Rats received specific blockers for the mast cell products histamine, serotonin (5HT), leukotriene D4, and platelet activating factor intraperitoneally 30 min before laparotomy and at the time of abdominal closure. Control animals received saline. Adhesions were assessed blindly 1 week later using a standardized scale. Adhesion formation was not affected by histamine blockade using combined mepyramine and ranitidine, 5-HT1 blockade using methysergide, 5-HT3 blockade using ondansetron, leukotriene D4 blockade using MK-571, or platelet activating factor blockade using WEB-2086. However, blockade of the 5-HT2 receptor using ketanserin resulted in significant dose-dependent attenuation of adhesions compared to saline. These data suggest that mast cells mediate peritoneal adhesion formation in the rat through release of serotonin acting on 5HT2 receptors. Further understanding of this process may lead to new strategies for the prevention of postoperative adhesions.

  6. Mother/daughter intergenerational interviews: insights into qualitative interviewing.

    PubMed

    Clendon, Jill

    As part of a larger study examining the social history of the Well Child/Health and Development Record Book in New Zealand, mother-daughter intergenerational dyad interviews were undertaken. The inter-generational dyad interviews were utilised to explore why mothers often keep their children's Well Child/Health and Development Record Books (Plunket Books) well beyond the five years of age that the Well Child Nurse stops visiting. Mother-daughter intergenerational dyad interviews are not a commonly used method of interview but can elicit valuable information that may otherwise be overlooked. This article discusses the method with which the interviews were undertaken and argues that successful construction of mother/daughter intergenerational dyad interviews is the result of a combination of context and the resulting interaction between the mother, daughter and interviewer/researcher.

  7. Do Daughters Bring Out a Dad's 'Softer Side'?

    MedlinePlus

    ... wanted to learn if different brain responses to boys and girls might affect how dads treat their sons and ... the same to sad-faced photos of their boys and girls, daughters' smiles elicited stronger responses in areas of ...

  8. Residential radon daughter monitor based on alpha spectroscopy

    SciTech Connect

    Nazaroff, W.W.

    1980-05-01

    The radioactive daughters of radon-222 pose a serious indoor air quality problem in some circumstances. A technique for measuring the concentrations of these radioisotopes in air is presented. The method involves drawing air through a filter; then, for two time intervals after sampling, counting the alpha decays from polonium-218 and polonium-214 on the filter. The time intervals are optimized to yield the maximum resolution between the individual daughter concentrations. For a total measurement time of 50 minutes, individual daughter concentrations of 1.0 nanocuries per cubic meter are measured with an uncertainty of 20%. A prototype of a field monitor based on this technique is described, as is a field test in which the prototype was used to measure radon daughter concentrations as a function of ventilation conditions in an energy-efficient house.

  9. Weighting factors of sire daughter information in international genetic evaluations.

    PubMed

    Fikse, W F; Banos, G

    2001-07-01

    International genetic evaluations of dairy bulls are currently based on national genetic evaluation results. Total number of daughters in a country is used to weight national information, but may not optimally reflect the precision of a sire's daughter contribution to international genetic evaluations. This study investigates the impact of alternative weighting factors on international evaluation results. A conventional progeny test scheme was simulated for two dairy cattle populations, with semen exchange at a fixed rate after each generation. True breeding values for both populations were generated as bivariate normal deviates. Each cow had three lactation records in one country only. After 10 generations of selection, all records were used in national breeding value prediction. National breeding values of bulls were used as input to international evaluations. Seven different weighting factors were evaluated: 1) total number of daughters; 2) total number of lactations; 3) as (one) also adjusted for finite contemporary group size; 4) as (three) also adjusted for distribution of daughters over contemporary groups; 5) effective daughter contribution considering finite contemporary group size and correlation between repeated records; 6) as (five) also considering the reliability of the daughter dam evaluation; and 7) as (five) also considering the reliability of the daughter female ancestors' evaluations. Using the last two weighting factors yielded empirically unbiased estimates of sire variance. Using total number of daughters overestimated genetic variance by up to 7%. In general, international breeding values were marginally affected by choice of weighting factor. The effect was larger when different national evaluation models had been applied in the two countries. International reliabilities for the last two weighting factors were close to expectation, whereas using total number of daughters resulted in 1 to 4% negative bias. In practice, different countries

  10. Incest and its meaning: the perspectives of fathers and daughters.

    PubMed

    Phelan, P

    1995-01-01

    This article describes incestuous events and the structure of meaning surrounding the events by biologic fathers and stepfathers and biologic daughters and stepdaughters. Using a symbolic interaction framework the study is guided by the thesis that the meanings people attach to incestuous events are central to understanding the phenomena of incest. Data were obtained from indepth interviews with 40 men (14 natural fathers and 26 stepfathers) and 44 children (18 biologic daughters and 26 stepdaughters). The interviews emphasized fathers' and daughters' recollection of events and their thoughts and interpretations of the incestuous activity while it was occurring. Both fathers and daughters reported that the sexual activity grew out of already existing family interactions. However, fathers and daughters' cognitions surrounding the events differed dramatically. Many of the fathers said their thoughts were dominated by themes of sexual gratification, control, power and anger, and rights and responsibilities vis-à-vis their role as father or stepfather. Daughters reported disbelief, confusion, guilt, and anger. According to fathers, they completely misread their child's reaction to what was happening. Although fathers said that they knew what they were doing was wrong, few reported that they were concerned with possible legal consequences.

  11. Contamination of individuals by radon daughters: a preliminary study

    SciTech Connect

    Stebbings, J.H.; Dignam, J.J.

    1988-03-01

    Body radon daughter contamination reflects relative individual respiratory exposures to radon daughters; counts can be related both to household radon levels and to lung cancer risk factors such as sex and tobacco smoking. Radon daughters were counted by gamma spectroscopy from 180 adult residents of eastern Pennsylvania. A seven-position, 35-min scan was conducted in a mobile body counter, generally during afternoon or evening hours. Track-etch detectors for household radon were distributed, and were recovered from 80% of the subjects. Over 75% of the population had environmentally enhanced radon daughter contamination. House radon levels were strongly related, as anticipated, to radon daughter contamination in the 112 subjects for whom both sets of measurements were available (p less than .001); basement measurements were as strongly related to personal contamination as were living area measurements; bedroom measurements were slightly more strongly correlated. Both sex (p less than .02) and cigarette smoking (p less than .01) significantly modified the relationships, after nonlinear adjustment for travel times. Using a logarithmic model, a given house living-area radon level was associated in females with body contamination by radon daughters 2-3 times that in males. Nonsmokers had 2-4 times higher levels of contamination than smokers. Results are for the total of internal and external contamination, these being highly correlated in preliminary experiments. Time usage and activity patterns of the subjects are believed to be important in explaining these findings, and may become important variables in radon risk assessment.

  12. Risks for Hypertension among Undiagnosed African American Mothers and Daughters

    PubMed Central

    Taylor, Jacquelyn Y.

    2009-01-01

    Introduction This study examines risks for high blood pressure (BP) among undiagnosed African American (AA) mothers and daughters, because AA children are at risk for hypertension due to familial influences. Method This study was cross-sectional in design and included 70 AA mother and daughter participants from the Detroit metropolitan area. Results BP readings clinically diagnostic of hypertension were found for mothers (25.7%) and daughters (54.3%), although they were undiagnosed. Many participants with BP readings in pre-hypertension or hypertension categories were overweight or obese (mothers, 90.9%; daughters, 50.2%). Fewer underweight or normal weight mothers (25.0%) and daughters (64.3%) had BP readings indicative of hypertension. Lower diastolic BP was associated with higher body mass index (BMI) among mothers (r = −.34, p = .045). Higher systolic blood pressure was positively related to potassium consumption among daughters and total AAs (r = .55, p = .005 and r = .41, p = .003 respectively). Discussion Early screening for hypertension is needed to improve health among AAs. Health providers should use American Academy of Pediatrics (AAP) guidelines for determining hypertension in children. Research on familial and environment influences on BP among children is recommended to determine early risk for hypertension development. PMID:19875025

  13. Upward Communication About Cancer Screening—Adolescent Daughter to Mother

    PubMed Central

    MOSAVEL, MAGHBOEBA; PORTS, KATIE A.

    2015-01-01

    Substantial breast and cervical cancer disparities exist in the United States, particularly among African American women with low social economic status. There is considerable potential for discussions about cancer prevention between mothers and daughters. However, upward communication, from child to parent, remains a relatively novel research area, and it remains unclear how receptive mothers would be to messages from their daughter about cancer, a topic that may be considered culturally inappropriate for daughters to initiate. In this study, we simulated cancer message delivery to daughters and then conducted direct observation of daughters as they recalled and shared the message with their mother or female elder. We found that daughters were able to successfully recall and deliver a cancer appeal to their mother and mothers were generally receptive to this message. Not only did mothers listen to their daughters’ appeals, but also daughters’ knowledge of cancer was considerably improved by the opportunity to educate her female elder. Moreover, daughters’ nonverbal communication suggested a surprisingly relaxed demeanor. The potential of young people to impact the screening behavior of their female elders is very promising in terms of reducing cancer disparities. PMID:25848895

  14. Polyphenols action against oxidative stress formation in endothelial cells.

    PubMed

    Łuczaj, Wojciech; Zapora, Ewa; Szczepański, Marek; Wnuczko, Krzysztof; Skrzydlewska, Elzbieta

    2009-01-01

    The aim of this study was to investigate the influence of epigallocatechin-3-gallate (EGCG), theaflavins (TFs) and black tea extract (BTE) on oxidative stress formation as well as on antioxidant system of human vein endothelial cells (HUVEC). HUVEC were incubated for 0,5 h with 100 mM tert-butyl hydroperoxide (t-BHP) for oxidative stress formation. The influence of EGCG, TFs, and BTE on oxidative stress and antioxidant system parameters was investigated by the pre-incubation for 2 h with 50 mg/mL of each compound. Half hour exposure to t-BHP caused statistically significant decrease in GSH-Px activity and in the content of GSH, vitamin A, vitamin E as well as tryptophan. Moreover, pretreatment of cells with t-BHP caused statistically significant increase in activities of Cu,Zn-SOD, GSSG-R and in the level of MDA and dityrosine. Pretreated with t-BHP endothelial cells, subjected to EGCG, TFs and black tea extract, are partially protected against oxidative activity of t-BHP causing statistically significant increase in GSH-Px activity, GSH and tryptophan level and decrease in MDA and dityrosine level in comparison with HUVEC pretreated with t-BHP group. These results indicate the beneficial effect of tea polyphenolic compounds on HUVEC antioxidant abilities and, in consequence, their protective effect in cell components.

  15. Emitter formation in dendritic web silicon solar cells

    NASA Technical Reports Server (NTRS)

    Meier, D. L.; Rohatgi, A.; Campbell, R. B.; Alexander, P.; Fonash, S. J.; Singh, R.

    1984-01-01

    The use of liquid dopants and liquid masks for p-n junction formation in dendritic web solar cells was investigated and found to be equivalent to the use of gaseous dopants and CVD SiO2 masks previously used. This results in a projected cost reduction of 0.02 1980$/Watt for a 25 MW/year production line, and makes possible junction formation processes having a higher throughput than more conventional processes. The effect of a low-energy (0.4 keV) hydrogen ion implant on dendritic web solar cells was also investigated. Such an implant was observed to improve Voc and Jsc substantially. Measurements of internal quantum efficiency suggest that it is the base of the cell, rather than the emitter, which benefits from the hydrogen implant. The diffusion length for electrons in the p-type base increased from 53 microns to 150 microns in one case, with dendritic web cell efficiency being boosted to 15.2 percent. The mechanism by which low-energy hydrogen ions can penetrate deeply into the silicon to effect the observed improvement is not known at this time.

  16. Molecular mechanism of parallel fiber-Purkinje cell synapse formation.

    PubMed

    Mishina, Masayoshi; Uemura, Takeshi; Yasumura, Misato; Yoshida, Tomoyuki

    2012-01-01

    The cerebellum receives two excitatory afferents, the climbing fiber (CF) and the mossy fiber-parallel fiber (PF) pathway, both converging onto Purkinje cells (PCs) that are the sole neurons sending outputs from the cerebellar cortex. Glutamate receptor δ2 (GluRδ2) is expressed selectively in cerebellar PCs and localized exclusively at the PF-PC synapses. We found that a significant number of PC spines lack synaptic contacts with PF terminals and some of residual PF-PC synapses show mismatching between pre- and postsynaptic specializations in conventional and conditional GluRδ2 knockout mice. Studies with mutant mice revealed that in addition to PF-PC synapse formation, GluRδ2 is essential for synaptic plasticity, motor learning, and the restriction of CF territory. GluRδ2 regulates synapse formation through the amino-terminal domain, while the control of synaptic plasticity, motor learning, and CF territory is mediated through the carboxyl-terminal domain. Thus, GluRδ2 is the molecule that bridges synapse formation and motor learning. We found that the trans-synaptic interaction of postsynaptic GluRδ2 and presynaptic neurexins (NRXNs) through cerebellin 1 (Cbln1) mediates PF-PC synapse formation. The synaptogenic triad is composed of one molecule of tetrameric GluRδ2, two molecules of hexameric Cbln1 and four molecules of monomeric NRXN. Thus, GluRδ2 triggers synapse formation by clustering four NRXNs. These findings provide a molecular insight into the mechanism of synapse formation in the brain.

  17. Formation of extracellular matrix by cultured rat mesangial cells.

    PubMed Central

    Ishimura, E.; Sterzel, R. B.; Budde, K.; Kashgarian, M.

    1989-01-01

    Formation of extracellular matrix (ECM) by mesangial cells (MCs) contributes to progressive glomerulosclerosis. The authors investigated the production and distribution of ECM constituents by cultured rat MCs, using immunocytochemistry and immunoelectron microscopy. Staining for all ECM constituents increased after serum feeding. Localization was strictly intracellular until confluency, when extracellular deposition of collagen IV and laminin appeared, followed by fibronectin and collagen III. In parallel, the intracellular staining for these proteins diminished markedly. Neither extracellular deposition nor intracellular loss was observed for collagen I and thrombospondin. On surfaces coated with collagen IV or laminin, extracellular deposition of ECM constituents clearly preceded confluency. These results indicate that synthesis of ECM constituents parallels MC growth, and that extracellular deposition of ECM occurs at cell-cell contact. Collagen IV or laminin secreted by MCs in the substratum accelerates production and facilitates secretion of other ECM constituents in an autocrine fashion. Images Figure 1 Figure 3 Figure 5 Figure 6 Figure 8 PMID:2650558

  18. Pristionchus pacificus vulva formation: polarized division, cell migration, cell fusion, and evolution of invagination.

    PubMed

    Kolotuev, Irina; Podbilewicz, Benjamin

    2004-02-15

    Tube formation is a widespread process during organogenesis. Specific cellular behaviors participate in the invagination of epithelial monolayers that form tubes. However, little is known about the evolutionary mechanisms of cell assembly into tubes during development. In Caenorhabditis elegans, the detailed step-to-step process of vulva formation has been studied in wild type and in several mutants. Here we show that cellular processes during vulva development, which involve toroidal cell formation and stacking of rings, are conserved between C. elegans and Pristionchus pacificus, two species of nematodes that diverged approximately 100 million years ago. These cellular behaviors are divided into phases of cell proliferation, short-range migration, and cell fusion that are temporally distinct in C. elegans but not in P. pacificus. Thus, we identify heterochronic changes in the cellular events of vulva development between these two species. We find that alterations in the division axes of two equivalent vulval cells from Left-Right cleavage in C. elegans to Anterior-Posterior division in P. pacificus can cause the formation of an additional eighth ring. Thus, orthogonal changes in cell division axes with alterations in the number and sequence of cell fusion events result in dramatic differences in vulval shape and in the number of rings in the species studied. Our characterization of vulva formation in P. pacificus compared to C. elegans provides an evolutionary-developmental foundation for molecular genetic analyses of organogenesis in different species within the phylum Nematoda.

  19. Mothers' and Fathers' Perceptions of Their Adolescent Daughters' Shape, Weight, and Body Esteem: Are They Accurate?

    ERIC Educational Resources Information Center

    Geller, Josie; Srikameswaran, Suja; Zaitsoff, Shannon L.; Cockell, Sarah J.; Poole, Gary D.

    2003-01-01

    Examined parents' awareness of their daughters' attitudes, beliefs, and feelings about their bodies. Sixty-six adolescent daughters completed an eating disorder scale, a body figure rating scale, and made ratings of their shape and weight. Greater discrepancies between parents' estimates of daughters' body esteem and daughters' self-reported body…

  20. Mothers' and Fathers' Perceptions of Their Adolescent Daughters' Shape, Weight, and Body Esteem: Are They Accurate?

    ERIC Educational Resources Information Center

    Geller, Josie; Srikameswaran, Suja; Zaitsoff, Shannon L.; Cockell, Sarah J.; Poole, Gary D.

    2003-01-01

    Examined parents' awareness of their daughters' attitudes, beliefs, and feelings about their bodies. Sixty-six adolescent daughters completed an eating disorder scale, a body figure rating scale, and made ratings of their shape and weight. Greater discrepancies between parents' estimates of daughters' body esteem and daughters' self-reported body…

  1. Mothers with breast cancer and their adult daughters: the relationship between mothers' reaction to breast cancer and their daughters' emotional and neuroimmune status.

    PubMed

    Cohen, Miri; Pollack, Shimon

    2005-01-01

    The objectives of this study were to assess the associations between psychologic distress of patients with breast cancer and of their adult daughters; and to assess the associations between mothers' psychologic distress and daughters' psychologic distress, stress hormone levels, natural cytotoxic activity (NCA), and Th1 cytokine secretion. Eighty mothers with breast cancer and 80 adult daughters participated in the study. They completed the Symptom Check List (SCL-90R) questionnaire. In addition, daughters completed a set of questions on their health status and habits and on the effects of their mothers' disease on their own lives. Thirty milliliters of heparinized venous blood and a first early-morning urine sample were collected from daughters between 8:00 and 9:00 am. Spontaneous and interleukin-2 (IL-2)-induced NCA, in vitro IL-2 and IL-12 secretion, and levels of plasma cortisol and urinary catecholamines were tested in daughters. Forty-seven healthy women, age- and education- matched to daughters, completed the psychologic, immunologic, and hormonal tests, and served as a control group. Psychologic distress of mothers and daughters was highly correlated. However, mothers experienced a higher level of distress than daughters. Mothers with advanced disease and their daughters were more distressed than mothers with primary disease and their daughters. Daughters' distress was also related to their subjective caregiving burden and the frequency of meetings with mothers. Higher distressed daughters had lower IL-2-induced NCA and decreased in vitro IL-2 and IL-12 secretion. Norepinephrine secretion level mediated the relationship between daughters' level of distress and their immune functions. Cortisol mediated only the relationship between daughters' distress and IL-2 secretion. This initial study shows that the psychologic distress of mothers with breast cancer and that of their adult daughters are similar. Stress hormone secretions and immune functions of

  2. Schwann Cells in Neuromuscular Junction Formation and Maintenance.

    PubMed

    Barik, Arnab; Li, Lei; Sathyamurthy, Anupama; Xiong, Wen-Cheng; Mei, Lin

    2016-09-21

    The neuromuscular junction (NMJ) is a tripartite synapse that is formed by motor nerve terminals, postjunctional muscle membranes, and terminal Schwann cells (TSCs) that cover the nerve-muscle contact. NMJ formation requires intimate communications among the three different components. Unlike nerve-muscle interaction, which has been well characterized, less is known about the role of SCs in NMJ formation and maintenance. We show that SCs in mice lead nerve terminals to prepatterned AChRs. Ablating SCs at E8.5 (i.e., prior nerve arrival at the clusters) had little effect on aneural AChR clusters at E13.5, suggesting that SCs may not be necessary for aneural clusters. SC ablation at E12.5, a time when phrenic nerves approach muscle fibers, resulted in smaller and fewer nerve-induced AChR clusters; however, SC ablation at E15.5 reduced AChR cluster size but had no effect on cluster density, suggesting that SCs are involved in AChR cluster maturation. Miniature endplate potential amplitude, but not frequency, was reduced when SCs were ablated at E15.5, suggesting that postsynaptic alterations may occur ahead of presynaptic deficits. Finally, ablation of SCs at P30, after NMJ maturation, led to NMJ fragmentation and neuromuscular transmission deficits. Miniature endplate potential amplitude was reduced 3 d after SC ablation, but both amplitude and frequency were reduced 6 d after. Together, these results indicate that SCs are not only required for NMJ formation, but also necessary for its maintenance; and postsynaptic function and structure appeared to be more sensitive to SC ablation. Neuromuscular junctions (NMJs) are critical for survival and daily functioning. Defects in NMJ formation during development or maintenance in adulthood result in debilitating neuromuscular disorders. The role of Schwann cells (SCs) in NMJ formation and maintenance was not well understood. We genetically ablated SCs during development and after NMJ formation to investigate the consequences

  3. Schwann Cells in Neuromuscular Junction Formation and Maintenance

    PubMed Central

    Barik, Arnab; Li, Lei; Sathyamurthy, Anupama; Xiong, Wen-Cheng

    2016-01-01

    The neuromuscular junction (NMJ) is a tripartite synapse that is formed by motor nerve terminals, postjunctional muscle membranes, and terminal Schwann cells (TSCs) that cover the nerve-muscle contact. NMJ formation requires intimate communications among the three different components. Unlike nerve-muscle interaction, which has been well characterized, less is known about the role of SCs in NMJ formation and maintenance. We show that SCs in mice lead nerve terminals to prepatterned AChRs. Ablating SCs at E8.5 (i.e., prior nerve arrival at the clusters) had little effect on aneural AChR clusters at E13.5, suggesting that SCs may not be necessary for aneural clusters. SC ablation at E12.5, a time when phrenic nerves approach muscle fibers, resulted in smaller and fewer nerve-induced AChR clusters; however, SC ablation at E15.5 reduced AChR cluster size but had no effect on cluster density, suggesting that SCs are involved in AChR cluster maturation. Miniature endplate potential amplitude, but not frequency, was reduced when SCs were ablated at E15.5, suggesting that postsynaptic alterations may occur ahead of presynaptic deficits. Finally, ablation of SCs at P30, after NMJ maturation, led to NMJ fragmentation and neuromuscular transmission deficits. Miniature endplate potential amplitude was reduced 3 d after SC ablation, but both amplitude and frequency were reduced 6 d after. Together, these results indicate that SCs are not only required for NMJ formation, but also necessary for its maintenance; and postsynaptic function and structure appeared to be more sensitive to SC ablation. SIGNIFICANCE STATEMENT Neuromuscular junctions (NMJs) are critical for survival and daily functioning. Defects in NMJ formation during development or maintenance in adulthood result in debilitating neuromuscular disorders. The role of Schwann cells (SCs) in NMJ formation and maintenance was not well understood. We genetically ablated SCs during development and after NMJ formation to

  4. Vesicle Size Regulates Nanotube Formation in the Cell.

    PubMed

    Su, Qian Peter; Du, Wanqing; Ji, Qinghua; Xue, Boxin; Jiang, Dong; Zhu, Yueyao; Lou, Jizhong; Yu, Li; Sun, Yujie

    2016-04-07

    Intracellular membrane nanotube formation and its dynamics play important roles for cargo transportation and organelle biogenesis. Regarding the regulation mechanisms, while much attention has been paid on the lipid composition and its associated protein molecules, effects of the vesicle size has not been studied in the cell. Giant unilamellar vesicles (GUVs) are often used for in vitro membrane deformation studies, but they are much larger than most intracellular vesicles and the in vitro studies also lack physiological relevance. Here, we use lysosomes and autolysosomes, whose sizes range between 100 nm and 1 μm, as model systems to study the size effects on nanotube formation both in vivo and in vitro. Single molecule observations indicate that driven by kinesin motors, small vesicles (100-200 nm) are mainly transported along the tracks while a remarkable portion of large vesicles (500-1000 nm) form nanotubes. This size effect is further confirmed by in vitro reconstitution assays on liposomes and purified lysosomes and autolysosomes. We also apply Atomic Force Microscopy (AFM) to measure the initiation force for nanotube formation. These results suggest that the size-dependence may be one of the mechanisms for cells to regulate cellular processes involving membrane-deformation, such as the timing of tubulation-mediated vesicle recycling.

  5. Biological surface engineering: a simple system for cell pattern formation.

    PubMed

    Zhang, S; Yan, L; Altman, M; Lässle, M; Nugent, H; Frankel, F; Lauffenburger, D A; Whitesides, G M; Rich, A

    1999-07-01

    Biological surface engineering using synthetic biological materials has a great potential for advances in our understanding of complex biological phenomena. We developed a simple system to engineer biologically relevant surfaces using a combination of self-assembling oligopeptide monolayers and microcontact printing (muCP). We designed and synthesized two oligopeptides containing a cell adhesion motif (RADS)n (n = 2 and 3) at the N-terminus, followed by an oligo(alanine) linker and a cysteine residue at the C-terminus. The thiol group of cysteine allows the oligopeptides to attach covalently onto a gold-coated surface to form monolayers. We then microfabricated a variety of surface patterns using the cell adhesion peptides in combination with hexa-ethylene glycol thiolate which resist non-specific adsorption of proteins and cells. The resulting patterns consist of areas either supporting or inhibiting cell adhesion, thus they are capable of aligning cells in a well-defined manner, leading to specific cell array and pattern formations.

  6. Genistein suppresses smooth muscle cell-derived foam cell formation through tyrosine kinase pathway.

    PubMed

    Lin, Jinghan; Xu, Yi; Zhao, Tingting; Sun, Lina; Yang, Meimei; Liu, Tingjiao; Sun, Hui; Zhang, Liming

    2015-08-07

    Genistein, as a protein tyrosine kinase inhibitor, has been shown to possess anti-atherosclerotic effects. Since the smooth muscle cell-derived foam cells are key components of atherosclerotic plaques. The aim of this study is to investigate the influence of genistein on foam cell transformation from vascular smooth muscle cells and possible mechanisms contributing to these effects. Vascular smooth muscle cells exposed to ox-LDL developed into foam cell, as demonstrated by Oil Red O staining and cholesterol content analysis. Ox-LDL induced phenotype transformation of smooth muscle cells, decreased expression of α-actin and increased expression of CD68 (a specific marker for monocytes, can also function as a subtype of scavenger receptors). The expression of scavenger receptors CD36 and LOX-1 was measured, and their role in foam cell formation in the presence of genistein, daidzein (a structurally similar analogue of genistein) and herbimycin A (a commonly tyrosine kinase inhibitor). The results showed that foam cell formation was markedly reduced by genistein and herbimycin A, as well as the expression of CD68, CD36 and LOX-1. However, daidzein had no such effect. In addition, genistein-induced down-regulation of CD68, CD36 and LOX-1 could be reversed by sodium orthovanadate (a membrane-permeable protein tyrosine phosphatase inhibitor). The results showed that ox-LDL induce smooth muscle cell-derived foam cell formation and transform the phenotype of smooth muscle cell. While tyrosine kinase inhibitor, genistein could suppress smooth muscle cell-derived foam cell formation through inhibiting the protein expressions of CD68, CD36 and LOX-1. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. A microfluidic direct formate fuel cell on paper.

    PubMed

    Copenhaver, Thomas S; Purohit, Krutarth H; Domalaon, Kryls; Pham, Linda; Burgess, Brianna J; Manorothkul, Natalie; Galvan, Vicente; Sotez, Samantha; Gomez, Frank A; Haan, John L

    2015-08-01

    We describe the first direct formate fuel cell on a paper microfluidic platform. In traditional membrane-less microfluidic fuel cells (MFCs), external pumping consumes power produced by the fuel cell in order to maintain co-laminar flow of the anode stream and oxidant stream to prevent mixing. However, in paper microfluidics, capillary action drives flow while minimizing stream mixing. In this work, we demonstrate a paper MFC that uses formate and hydrogen peroxide as the anode fuel and cathode oxidant, respectively. Using these materials we achieve a maximum power density of nearly 2.5 mW/mg Pd. In a series configuration, our MFC achieves an open circuit voltage just over 1 V, and in a parallel configuration, short circuit of 20 mA absolute current. We also demonstrate that the MFC does not require continuous flow of fuel and oxidant to produce power. We found that we can pre-saturate the materials on the paper, stop the electrolyte flow, and still produce approximately 0.5 V for 15 min. This type of paper MFC has potential applications in point-of-care diagnostic devices and other electrochemical sensors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Cell collectivity regulation within migrating cell cluster during Kupffer's vesicle formation in zebrafish

    PubMed Central

    Matsui, Takaaki; Ishikawa, Hiroshi; Bessho, Yasumasa

    2015-01-01

    Although cell adhesion is thought to fasten cells tightly, cells that adhere to each other can migrate directionally. This group behavior, called “collective cell migration,” is observed during normal development, wound healing, and cancer invasion. Loss-of-function of cell adhesion molecules in several model systems of collective cell migration results in delay or inhibition of migration of cell groups but does not lead to dissociation of the cell groups, suggesting that mechanisms of cells staying assembled as a single cell cluster, termed as “cell collectivity,” remain largely unknown. During the formation of Kupffer's vesicle (KV, an organ of laterality in zebrafish), KV progenitors form a cluster and migrate together toward the vegetal pole. Importantly, in this model system of collective cell migration, knockdown of cell adhesion molecules or signal components leads to failure of cell collectivity. In this review, we summarize recent findings in cell collectivity regulation during collective migration of KV progenitor cells and describe our current understanding of how cell collectivity is regulated during collective cell migration. PMID:26000276

  9. Cell collectivity regulation within migrating cell cluster during Kupffer's vesicle formation in zebrafish.

    PubMed

    Matsui, Takaaki; Ishikawa, Hiroshi; Bessho, Yasumasa

    2015-01-01

    Although cell adhesion is thought to fasten cells tightly, cells that adhere to each other can migrate directionally. This group behavior, called "collective cell migration," is observed during normal development, wound healing, and cancer invasion. Loss-of-function of cell adhesion molecules in several model systems of collective cell migration results in delay or inhibition of migration of cell groups but does not lead to dissociation of the cell groups, suggesting that mechanisms of cells staying assembled as a single cell cluster, termed as "cell collectivity," remain largely unknown. During the formation of Kupffer's vesicle (KV, an organ of laterality in zebrafish), KV progenitors form a cluster and migrate together toward the vegetal pole. Importantly, in this model system of collective cell migration, knockdown of cell adhesion molecules or signal components leads to failure of cell collectivity. In this review, we summarize recent findings in cell collectivity regulation during collective migration of KV progenitor cells and describe our current understanding of how cell collectivity is regulated during collective cell migration.

  10. Maternal body mass index and daughters' age at menarche.

    PubMed

    Keim, Sarah A; Branum, Amy M; Klebanoff, Mark A; Zemel, Babette S

    2009-09-01

    The role of intergenerational influences on age at menarche has not been explored far beyond the association between mothers' and daughters' menarcheal ages. Small size at birth and childhood obesity have been associated with younger age at menarche, but the influence of maternal overweight or obesity on daughters' age at menarche has not been thoroughly examined. In a follow-up study of the prospective Collaborative Perinatal Project, grown daughters were asked in 1987-1991 for their age at menarche. Data from the original Collaborative Perinatal Project (1959-1966) included their mothers' height and prepregnancy weight. In the follow-up study, 597 of 627 daughters had complete menarche and maternal data available and were included in the present analysis. We used polytomous logistic regression to examine the association between maternal overweight (body mass index [BMI] = 25-29.9 km/m) or obesity (BMI >or= 30) and daughter's age at menarche (daughters of obese mothers experienced younger age at menarche (OR for menarche at daughters in this study, possibly via unmeasured shared factors.

  11. Graphene-Induced Pore Formation on Cell Membranes

    PubMed Central

    Duan, Guangxin; Zhang, Yuanzhao; Luan, Binquan; Weber, Jeffrey K.; Zhou, Royce W.; Yang, Zaixing; Zhao, Lin; Xu, Jiaying; Luo, Judong; Zhou, Ruhong

    2017-01-01

    Examining interactions between nanomaterials and cell membranes can expose underlying mechanisms of nanomaterial cytotoxicity and guide the design of safer nanomedical technologies. Recently, graphene has been shown to exhibit potential toxicity to cells; however, the molecular processes driving its lethal properties have yet to be fully characterized. We here demonstrate that graphene nanosheets (both pristine and oxidized) can produce holes (pores) in the membranes of A549 and Raw264.7 cells, substantially reducing cell viability. Electron micrographs offer clear evidence of pores created on cell membranes. Our molecular dynamics simulations reveal that multiple graphene nanosheets can cooperate to extract large numbers of phospholipids from the membrane bilayer. Strong dispersion interactions between graphene and lipid-tail carbons result in greatly depleted lipid density within confined regions of the membrane, ultimately leading to the formation of water-permeable pores. This cooperative lipid extraction mechanism for membrane perforation represents another distinct process that contributes to the molecular basis of graphene cytotoxicity. PMID:28218295

  12. Magnetization of individual yeast cells by in situ formation of iron oxide on cell surfaces

    NASA Astrophysics Data System (ADS)

    Choi, Jinsu; Lee, Hojae; Choi, Insung S.; Yang, Sung Ho

    2017-09-01

    Magnetic functionalization of living cells has intensively been investigated with the aim of various bioapplications such as selective separation, targeting, and localization of the cells by using an external magnetic field. However, the magnetism has not been introduced to individual living cells through the in situ chemical reactions because of harsh conditions required for synthesis of magnetic materials. In this work, magnetic iron oxide was formed on the surface of living cells by optimizing reactions conditions to be mild sufficiently enough to sustain cell viability. Specifically, the reactive LbL strategy led to formation of magnetically responsive yeast cells with iron oxide shells. This facile and direct post-magnetization method would be a useful tool for remote manipulation of living cells with magnetic interactions, which is an important technique for the integration of cell-based circuits and the isolation of cell in microfluidic devices.

  13. Germ cells influence cord formation and Leydig cell gene expression during mouse testis development.

    PubMed

    Rios-Rojas, Clarissa; Spiller, Cassy; Bowles, Josephine; Koopman, Peter

    2016-04-01

    It is widely accepted that, during the development of testes in the mammalian embryo, male germ cells are influenced by signals from the surrounding somatic cells, but not vice versa, so that germ cells are dispensable for the formation of testes. We now demonstrate that development of the mouse fetal testis is compromised in the absence of germ cells. Using two- and three-dimensional imaging techniques, we reveal that W(e)/W(e) mutant testes devoid of germ cells have misshapen and poorly organized cords. We also found that mutant gonads have fewer Sertoli cells than normal and that the Leydig cells express key markers at higher than normal levels. These observations point to the existence of germ cell-derived signals that directly or indirectly affect the Sertoli and Leydig cell populations, and provide a new paradigm for the organogenesis of the mammalian testes. © 2015 Wiley Periodicals, Inc.

  14. Formation of nanofilms on cell surfaces to improve the insertion efficiency of a nanoneedle into cells

    SciTech Connect

    Amemiya, Yosuke; Kawano, Keiko; Matsusaki, Michiya; Akashi, Mitsuru; Nakamura, Noriyuki; Nakamura, Chikashi

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer We examined the insertion efficiency of nanoneedles into fibroblast and neural cells. Black-Right-Pointing-Pointer Nanofilms formed on cell surfaces improved the insertion efficiency of nanoneedles. Black-Right-Pointing-Pointer Nanofilms improved the insertion efficiency even in Y27632-treated cells. -- Abstract: A nanoneedle, an atomic force microscope (AFM) tip etched to 200 nm in diameter and 10 {mu}m in length, can be inserted into cells with the aid of an AFM and has been used to introduce functional molecules into cells and to analyze intracellular information with minimal cell damage. However, some cell lines have shown low insertion efficiency of the nanoneedle. Improvement in the insertion efficiency of a nanoneedle into such cells is a significant issue for nanoneedle-based cell manipulation and analysis. Here, we have formed nanofilms composed of extracellular matrix molecules on cell surfaces and found that the formation of the nanofilms improved insertion efficiency of a nanoneedle into fibroblast and neural cells. The nanofilms were shown to improve insertion efficiency even in cells in which the formation of actin stress fibers was inhibited by the ROCK inhibitor Y27632, suggesting that the nanofilms with the mesh structure directly contributed to the improved insertion efficiency of a nanoneedle.

  15. Notch1-Dll4 signaling and mechanical force regulate leader cell formation during collective cell migration

    PubMed Central

    Riahi, Reza; Sun, Jian; Wang, Shue; Long, Min; Zhang, Donna D.; Wong, Pak Kin

    2015-01-01

    At the onset of collective cell migration, a subset of cells within an initially homogenous population acquires a distinct “leader” phenotype with characteristic morphology and motility. However, the factors driving leader cell formation as well as the mechanisms regulating leader cell density during the migration process remain to be determined. Here, we use single cell gene expression analysis and computational modeling to show that leader cell identity is dynamically regulated by Dll4 signaling through both Notch1 and cellular stress in a migrating epithelium. Time-lapse microscopy reveals that Dll4 is induced in leader cells after the creation of the cell-free region and leader cells are regulated via Notch1-Dll4 lateral inhibition. Furthermore, mechanical stress inhibits Dll4 expression and leader cell formation in the monolayer. Collectively, our findings suggest that a reduction of mechanical force near the boundary promotes Notch1-Dll4 signaling to dynamically regulate the density of leader cells during collective cell migration. PMID:25766473

  16. Notch1-Dll4 signalling and mechanical force regulate leader cell formation during collective cell migration.

    PubMed

    Riahi, Reza; Sun, Jian; Wang, Shue; Long, Min; Zhang, Donna D; Wong, Pak Kin

    2015-03-13

    At the onset of collective cell migration, a subset of cells within an initially homogenous population acquires a distinct 'leader' phenotype with characteristic morphology and motility. However, the factors driving the leader cell formation as well as the mechanisms regulating leader cell density during the migration process remain to be determined. Here we use single-cell gene expression analysis and computational modelling to show that the leader cell identity is dynamically regulated by Dll4 signalling through both Notch1 and cellular stress in a migrating epithelium. Time-lapse microscopy reveals that Dll4 is induced in leader cells after the creation of the cell-free region and leader cells are regulated via Notch1-Dll4 lateral inhibition. Furthermore, mechanical stress inhibits Dll4 expression and leader cell formation in the monolayer. Collectively, our findings suggest that a reduction of mechanical force near the boundary promotes Notch1-Dll4 signalling to dynamically regulate the density of leader cells during collective cell migration.

  17. Dynamic formation of oriented patches in chondrocyte cell cultures.

    PubMed

    Grote, Marcus J; Palumberi, Viviana; Wagner, Barbara; Barbero, Andrea; Martin, Ivan

    2011-10-01

    Growth factors have a significant impact not only on the growth dynamics but also on the phenotype of chondrocytes (Barbero et al. in J. Cell. Phys. 204:830-838, 2005). In particular, as chondrocytes approach confluence, the cells tend to align and form coherent patches. Starting from a mathematical model for fibroblast populations at equilibrium (Mogilner et al. in Physica D 89:346-367, 1996), a dynamic continuum model with logistic growth is developed. Both linear stability analysis and numerical solutions of the time-dependent nonlinear integro-partial differential equation are used to identify the key parameters that lead to pattern formation in the model. The numerical results are compared quantitatively to experimental data by extracting statistical information on orientation, density and patch size through Gabor filters.

  18. Coordinate Stimulation of Macrophages by Microparticles and TLR Ligands Induces Foam Cell Formation1

    PubMed Central

    Keyel, Peter A; Tkacheva, Olga A.; Larregina, Adriana T.; Salter, Russell D

    2012-01-01

    Aberrant activation of macrophages in arterial walls by oxidized lipoproteins can lead to atherosclerosis. Oxidized lipoproteins convert macrophages to foam cells through lipid uptake and TLR signaling. To investigate the relative contributions of lipid uptake and TLR signaling in foam cell formation, we established an in vitro assay utilizing liposomes of defined lipid compositions. We found that TLRs signaling through Trif promoted foam cell formation by inducing both NF-KB signaling and Type I IFN production, whereas TLRs that do not induce IFN, like TLR2, did not enhance foam cell formation. Addition of IFNα to TLR2 activator promoted robust foam cell formation. TLR signaling further required PPARα, as inhibition of PPARα blocked foam cell formation. We then investigated the ability of endogenous microparticles (MP) to contribute to foam cell formation. We found that lipid containing MP promoted foam cell formation, which was enhanced by TLR stimulation or IFNα. These MP also stimulated foam cell formation in a human skin model. However, these MP suppressed TNFα production and T cell activation, showing that foam cell formation can occur by immunosuppressive microparticles. Taken together, the data reveal novel signaling requirements for foam cell formation and suggest that uptake of distinct types of MP in the context of activation of multiple distinct TLR can induce foam cell formation. PMID:23018455

  19. Formation and Toxicity of Soluble Polyglutamine Oligomers in Living Cells

    PubMed Central

    Lajoie, Patrick; Snapp, Erik Lee

    2010-01-01

    Background Aggregation and cytotoxicity of mutant proteins containing an expanded number of polyglutamine (polyQ) repeats is a hallmark of several diseases, including Huntington's disease (HD). Within cells, mutant Huntingtin (mHtt) and other polyglutamine expansion mutant proteins exist as monomers, soluble oligomers, and insoluble inclusion bodies (IBs). Determining which of these forms constitute a toxic species has proven difficult. Recent studies support a role for IBs as a cellular coping mechanism to sequester levels of potentially toxic soluble monomeric and oligomeric species of mHtt. Methodology/Principal Findings When fused to a fluorescent reporter (GFP) and expressed in cells, the soluble monomeric and oligomeric polyglutamine species are visually indistinguishable. Here, we describe two complementary biophysical fluorescence microscopy techniques to directly detect soluble polyglutamine oligomers (using Htt exon 1 or Httex1) and monitor their fates in live cells. Photobleaching analyses revealed a significant reduction in the mobilities of mHttex1 variants consistent with their incorporation into soluble microcomplexes. Similarly, when fused to split-GFP constructs, both wildtype and mHttex1 formed oligomers, as evidenced by the formation of a fluorescent reporter. Only the mHttex1 split-GFP oligomers assembled into IBs. Both FRAP and split-GFP approaches confirmed the ability of mHttex1 to bind and incorporate wildtype Htt into soluble oligomers. We exploited the irreversible binding of split-GFP fragments to forcibly increase levels of soluble oligomeric mHttex1. A corresponding increase in the rate of IBs formation and the number formed was observed. Importantly, higher levels of soluble mHttex1 oligomers significantly correlated with increased mutant cytotoxicity, independent of the presence of IBs. Conclusions/Significance Our study describes powerful and sensitive tools for investigating soluble oligomeric forms of expanded polyglutamine

  20. Parental encouragement of dieting promotes daughters' early dieting.

    PubMed

    Balantekin, Katherine N; Savage, Jennifer S; Marini, Michele E; Birch, Leann L

    2014-09-01

    Dieting to lose weight is common among female adolescents. This research investigated the association between maternal and paternal encouragement to diet and their daughters' self-reported "early dieting" (prior to age 11 y) and adolescent dieting (between 11 y and 15 y), and how parental encouragement to diet is related to changes in daughters' BMI percentiles. Participants in this study were 174 non-Hispanic white girls and their parents, assessed when daughters were 9-, 11-, 13-, and 15 y. The Parent Encouragement of Child Weight Loss Scale was used to measure encouragement to diet. Logistic regression was used to examine the relationship between parental encouragement to diet and daughters' reports of dieting by 11 y and by 15 y, adjusting for daughters' weight status at baseline. Compared with girls whose mothers didn't encourage dieting, girls who were encouraged to diet were twice as likely to diet by 11 y; girls who were encouraged by their fathers were also twice as likely to diet by 11 y. Girls who were encouraged to diet by both parents were 8 times more likely to report early dieting than girls who were not. Neither maternal nor paternal encouragement predicted the emergence of dieting during adolescence. Girls who dieted and had parental encouragement to do so had increases in BMI percentile from 9 y to 15 y. Findings reveal that parental encouragement to diet may be counterproductive and that parents need alternative approaches to promote healthy patterns of intake and growth among young girls.

  1. Fabric-based alkaline direct formate microfluidic fuel cells.

    PubMed

    Domalaon, Kryls; Tang, Catherine; Mendez, Alex; Bernal, Franky; Purohit, Krutarth; Pham, Linda; Haan, John; Gomez, Frank A

    2017-04-01

    Fabric-based microfluidic fuel cells (MFCs) serve as a novel, cost-efficient alternative to traditional FCs and batteries, since fluids naturally travel across fabric via capillary action, eliminating the need for an external pump and lowering production and operation costs. Building on previous research with Y-shaped paper-based MFCs, fabric-based MFCs mitigate fragility and durability issues caused by long periods of fuel immersion. In this study, we describe a microfluidic fabric-based direct formate fuel cell, with 5 M potassium formate and 30% hydrogen peroxide as the anode fuel and cathode oxidant, respectively. Using a two-strip, stacked design, the optimized parameters include the type of encasement, the barrier, and the fabric type. Surface contact of the fabric and laminate sheet expedited flow and respective chemical reactions. The maximum current (22.83 mA/cm(2) ) and power (4.40 mW/cm(2) ) densities achieved with a 65% cotton/35% polyester blend material are a respective 8.7% and 32% higher than previous studies with Y-shaped paper-based MFCs. In series configuration, the MFCs generate sufficient energy to power a handheld calculator, a thermometer, and a spectrum of light-emitting diodes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Cadmium stimulates osteoclast-like multinucleated cell formation in mouse bone marrow cell cultures

    SciTech Connect

    Miyahara, Tatsuro; Takata, Masakazu; Miyata, Masaki; Nagai, Miyuki; Sugure, Akemi; Kozuka, Hiroshi; Kuze, Shougo )

    1991-08-01

    Most of cadmium (Cd)-treated animals have been reported to show osteoporosis-like changes in bones. This suggests that Cd may promote bone loss by a direct action on bone. It was found that Cd stimulated prostaglandin E{sub 2}(PGE{sub 2}) production in the osteoblast-like cell, MC3T3-E1. Therefore, Cd stimulates bone resorption by increasing PGE{sub 2} production. Recently, several bone marrow cell culture systems have been developed for examining the formation of osteoclast-like multinucleated cells in vitro. As osteoblasts produce PGE{sub 2} by Cd-induced cyclooxygenase and may play an important role in osteoclast formation, the present study was undertaken to clarify the possibility that Cd might stimulate osteoclast formation in a mouse bone marrow culture system.

  3. Arsenic promotes centrosome abnormalities and cell colony formation in p53 compromised human lung cells

    SciTech Connect

    Liao Weiting; Lin Pinpin; Cheng, T.-S.; Yu, H.-S.; Chang, Louis W.

    2007-12-01

    Epidemiological evidence indicated that residents, especially cigarette smokers, in arseniasis areas had significantly higher lung cancer risk than those living in non-arseniasis areas. Thus, an interaction between arsenic and cigarette smoking in lung carcinogenesis was suspected. p53 dysfunction or mutation in lung epithelial cells was frequently observed in cigarette smokers. Our present study was to explore the differential effects by arsenic on H1355 cells (human lung adenocarcinoma cell line with mutation in p53), BEAS-2B (immortalized lung epithelial cell with functional p53) and pifithrin-{alpha}-treated BEAS-2B cells (p53-inhibited cells). These cells were treated with different doses of sodium arsenite (0, 0.1, 1, 5 and 10 {mu}M) for 48 h. A greater reduction in cell viability was observed in the BEAS-2B cells vs. p53 compromised cells (H1355 or p53-inhibited BEAS-2B). Similar observation was also made on 7-day cell survival (growth) study. TUNEL analysis confirmed that there was indeed a significantly reduced arsenite-induced apoptosis found in p53-compromised cells. Centrosomal abnormality has been attributed to eventual chromosomal missegregation, aneuploidy and tumorigenesis. In our present study, reduced p21 and Gadd45a expressions and increased centrosomal abnormality (atopic and multiple centrosomes) were observed in both arsenite-treated H1355 and p53-inhibited BEAS-2B cells as compared with similarly treated BEAS-2B cells. Increased anchorage-independent growth (colony formation) of BEAS-2B cells co-treated with pifithrin-{alpha} and 5 {mu}M sodium arsenite was also observed in soft agar. Our present investigation demonstrated that arsenic would act specifically on p53 compromised cells (either with p53 dysfunction or inhibited) to induce centrosomal abnormality and colony formation. These findings provided strong evidence on the carcinogenic promotional role of arsenic, especially under the condition of p53 dysfunction.

  4. Apicoplast fatty acid synthesis is essential for pellicle formation at the end of cytokinesis in Toxoplasma gondii.

    PubMed

    Martins-Duarte, Érica S; Carias, Maira; Vommaro, Rossiane; Surolia, Namita; de Souza, Wanderley

    2016-09-01

    The apicomplexan protozoan Toxoplasma gondii, the causative agent of toxoplasmosis, harbors an apicoplast, a plastid-like organelle with essential metabolic functions. Although the FASII fatty acid biosynthesis pathway located in the apicoplast is essential for parasite survival, the cellular effects of FASII disruption in T. gondii had not been examined in detail. Here, we combined light and electron microscopy techniques - including focused ion beam scanning electron microscopy (FIB-SEM) - to characterize the effect of FASII disruption in T. gondii, by treatment with the FASII inhibitor triclosan or by inducible knockdown of the FASII component acyl carrier protein. Morphological analyses showed that FASII disruption prevented cytokinesis completion in T. gondii tachyzoites, leading to the formation of large masses of 'tethered' daughter cells. FIB-SEM showed that tethered daughters had a mature basal complex, but a defect in new membrane addition between daughters resulted in incomplete pellicle formation. Addition of exogenous fatty acids to medium suppressed the formation of tethered daughter cells and supports the notion that FASII is essential to generate lipid substrates required for the final step of parasite division.

  5. Meanings adult daughters attach to a parent's death.

    PubMed

    Kerr, R B

    1994-08-01

    The purpose of this qualitative study was to explore how meanings adult daughters attached to their parent's death influenced the duration of their grief. The sample consisted of 67 adult daughters, ages 35 to 69 years, who had lost a parent 1 to 3 years earlier. Respondents were asked to explore their perceptions about their parent's death, their lifelong parent-daughter relationship, and any lifestyle changes that occurred after a parent's death. Categories were identified from the interview questions, and themes within each category were developed from the interview data. Results indicated that how respondents experienced a parent's death--including their guilt, regrets, or anticipatory grief, shifts in other family relationships, and changes in lifestyle--influenced the duration of their grief. The findings suggest that the subjective experience of grief may be an important area for further research as well as for assessment and intervention.

  6. Dowry calculations: daughter's rights in her parental family.

    PubMed

    Kishwar, M

    1993-01-01

    The practice of dowry in India has become identified as the primary cause of women's oppression. It sets families apart in the fight over dowry payments and results in violence against daughters including infanticide. Daughter's get their share of inheritance at the time of marriage under traditional Hindu law. The Dowry Prohibition Act outlaws this practice. On the other hand, customary law allowed entitlements to women which Victorian norms bypassed, thereby paving the way for the disinheritance of women. The ownership of land was vested exclusively in men, and, as land became scarce and women's labor became devalued, women came to be treated as mere dependents and considered as a liability. With the entrance of men into government service as policemen and bank and postal clerks, their status increased, while women continued working in the peasant economy. Government job holders received the biggest dowries because of their access to economic opportunities. Under the Hindu Succession Act, fathers were allowed to will away property in whosoever's favor, which led to the disinheritance of daughters in favor of sons. Inheritance laws increasingly moved in favor of men and against women. Changing marriage patterns also emerged, as paying exorbitant dowries was perceived as a way of upward social mobility. The wife inherited everything at the expense of daughters, and widows automatically got a pension after the husband. Therefore, the wife's right had a stronger social sanction than the rights of daughters in parental property, especially the right to live in the parental home and take care of old parents, should be the solution to this injustice. Thus, parents would look at daughters in the same light as sons, and the culture of women's devaluation would come to an end.

  7. Protective layer formation on magnesium in cell culture medium.

    PubMed

    Wagener, V; Virtanen, S

    2016-06-01

    In the past, different studies showed that hydroxyapatite (HA) or similar calcium phosphates can be precipitated on Mg during immersion in simulated body fluids. However, at the same time, in most cases a dark grey or black layer is built under the white HA crystals. This layer seems to consist as well of calcium phosphates. Until now, neither the morphology nor its influence on Mg corrosion have been investigated in detail. In this work commercially pure magnesium (cp) was immersed in cell culture medium for one, three and five days at room temperature and in the incubator (37 °C, 5% CO2). In addition, the influence of proteins on the formation of a corrosion layer was investigated by adding 20% of fetal calf serum (FCS) to the cell culture medium in the incubator. In order to analyze the formed layers, SEM images of cross sections, X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDX) and Fourier Transformed Infrared Spectroscopy (FTIR) measurements were carried out. Characterization of the corrosion behavior was achieved by electrochemical impedance spectroscopy (EIS) and by potentio-dynamic polarization in Dulbecco's Modified Eagle's Medium (DMEM) at 37°C. Surface analysis showed that all formed layers consist mainly of amorphous calcium phosphate compounds. For the immersion at room temperature the Ca/P ratio indicates the formation of HA, while in the incubator probably pre-stages to HA are formed. The different immersion conditions lead to a variation in layer thicknesses. However, electrochemical characterization shows that the layer thickness does not influence the corrosion resistance of magnesium. The main influencing factor for the corrosion behavior is the layer morphology. Thus, immersion at room temperature leads to the highest corrosion protection due to the formation of a compact outer layer. Layers formed in the incubator show much worse performances due to completely porous structures. The

  8. Velocardiofacial syndrome in father and daughter: What is the mechanism for the deletion 22(q11.2q11.2) in only the daughter?

    SciTech Connect

    Magenis, R.E.; Gunter, K.; Toth-Fejel, S.

    1994-09-01

    E.G. had marked feeding difficulty noted at birth; the cause was determined to be a paralyzed palate. In 1992 chromosome studies were performed because of the provisional diagnosis of velocardiofacial syndrome, and a small interstitial deletion of chromosome 22 was found. Recently the family was seen in our Genetics Clinic. The father had unusual facial features shared by his daughter, a paralyzed upper lip and a history of repaired Tetralogy of Fallot. His chromosomes appeared normal. FISH studies were performed on the child`s peripheral blood using the ONCOR DiGeorge region probe (D22S75) and the deletion verified. However, the father`s chromosomes were not deleted for the ONCOR probe (D22S75) and probe DO832 sent to us by Peter Scambler. Skin cells were then obtained and no deletion was detected in a total of 66 cells examined using both probes. Several questions arise from these data: does the father have velocardiofacial syndrome? Does he have occult mosaicism? Does he have a molecular deletion not detected by the probes used? And was this deletion somehow {open_quotes}amplified{close_quotes} in his daughter?

  9. PERP regulates enamel formation via effects on cell-cell adhesion and gene expression.

    PubMed

    Jheon, Andrew H; Mostowfi, Pasha; Snead, Malcolm L; Ihrie, Rebecca A; Sone, Eli; Pramparo, Tiziano; Attardi, Laura D; Klein, Ophir D

    2011-03-01

    Little is known about the role of cell-cell adhesion in the development of mineralized tissues. Here we report that PERP, a tetraspan membrane protein essential for epithelial integrity, regulates enamel formation. PERP is necessary for proper cell attachment and gene expression during tooth development, and its expression is controlled by P63, a master regulator of stratified epithelial development. During enamel formation, PERP is localized to the interface between the enamel-producing ameloblasts and the stratum intermedium (SI), a layer of cells subjacent to the ameloblasts. Perp-null mice display dramatic enamel defects, which are caused, in part, by the detachment of ameloblasts from the SI. Microarray analysis comparing gene expression in teeth of wild-type and Perp-null mice identified several differentially expressed genes during enamel formation. Analysis of these genes in ameloblast-derived LS8 cells upon knockdown of PERP confirmed the role for PERP in the regulation of gene expression. Together, our data show that PERP is necessary for the integrity of the ameloblast-SI interface and that a lack of Perp causes downregulation of genes that are required for proper enamel formation.

  10. Tagging radon daughters in low-energy scintillation detectors

    NASA Astrophysics Data System (ADS)

    McCarty, Kevin B.

    2011-12-01

    One problematic source of background in scintillator-based low-energy solar neutrino experiments such as Borexino is the presence of radon gas and its daughters. The mean lifetime of the α-emitter 214Po in the radon chain is sufficiently short, 0.24 ms, that its decay, together with that immediately preceding of 214Bi, is easily recognized as a “coincidence event.” This fact, combined with the capability of α/β pulse-shape discrimination, makes it possible to tag decays of 222Rn and its first four daughters via a likelihood-based method.

  11. Transcriptional insights into the CD8(+) T cell response to infection and memory T cell formation.

    PubMed

    Best, J Adam; Blair, David A; Knell, Jamie; Yang, Edward; Mayya, Viveka; Doedens, Andrew; Dustin, Michael L; Goldrath, Ananda W

    2013-04-01

    After infection, many factors coordinate the population expansion and differentiation of CD8+ effector and memory T cells. Using data of unparalleled breadth from the Immunological Genome Project, we analyzed the CD8+ T cell transcriptome throughout infection to establish gene-expression signatures and identify putative transcriptional regulators. Notably, we found that the expression of key gene signatures can be used to predict the memory-precursor potential of CD8+ effector cells. Long-lived memory CD8+ cells ultimately expressed a small subset of genes shared by natural killer T and γδ T cells. Although distinct inflammatory milieu and T cell precursor frequencies influenced the differentiation of CD8+ effector and memory populations, core transcriptional signatures were regulated similarly, whether polyclonal or transgenic, and whether responding to bacterial or viral model pathogens. Our results provide insights into the transcriptional regulation that influence memory formation and CD8+ T cell immunity.

  12. Adherence to Intestinal Cells Promotes Biofilm Formation in Vibrio cholerae.

    PubMed

    Sengupta, Chirantana; Mukherjee, Oindrilla; Chowdhury, Rukhsana

    2016-11-15

    Vibrio cholerae, the etiological agent of cholera, is known to form biofilms to persist in the environment. It is demonstrated here that even during infection, biofilm genes are upregulated, and microscopic observation indicated that biofilm formation is initiated almost immediately after adherence of V. cholerae to intestinal cells. About 7-fold upregulation of the biofilm regulatory gene vpsT was observed within 30 minutes of adherence of V. cholerae to the intestinal cell line INT 407, and a massive induction of about 700-fold was observed in rabbit ileal loops. The upregulation was observed in the classical and El Tor biotype strains of serogroup O1 that is most frequently associated with epidemic cholera. vpsT upregulation was primarily dependent on the virulence master regulator AphA. Of possible clinical relevance was the observation that V. cholerae in the INT 407-associated biofilms was significantly more resistant to antibiotics than unadhered planktonic cells. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  13. Mechanical roles of apical constriction, cell elongation, and cell migration during neural tube formation in Xenopus.

    PubMed

    Inoue, Yasuhiro; Suzuki, Makoto; Watanabe, Tadashi; Yasue, Naoko; Tateo, Itsuki; Adachi, Taiji; Ueno, Naoto

    2016-12-01

    Neural tube closure is an important and necessary process during the development of the central nervous system. The formation of the neural tube structure from a flat sheet of neural epithelium requires several cell morphogenetic events and tissue dynamics to account for the mechanics of tissue deformation. Cell elongation changes cuboidal cells into columnar cells, and apical constriction then causes them to adopt apically narrow, wedge-like shapes. In addition, the neural plate in Xenopus is stratified, and the non-neural cells in the deep layer (deep cells) pull the overlying superficial cells, eventually bringing the two layers of cells to the midline. Thus, neural tube closure appears to be a complex event in which these three physical events are considered to play key mechanical roles. To test whether these three physical events are mechanically sufficient to drive neural tube formation, we employed a three-dimensional vertex model and used it to simulate the process of neural tube closure. The results suggest that apical constriction cued the bending of the neural plate by pursing the circumference of the apical surface of the neural cells. Neural cell elongation in concert with apical constriction further narrowed the apical surface of the cells and drove the rapid folding of the neural plate, but was insufficient for complete neural tube closure. Migration of the deep cells provided the additional tissue deformation necessary for closure. To validate the model, apical constriction and cell elongation were inhibited in Xenopus laevis embryos. The resulting cell and tissue shapes resembled the corresponding simulation results.

  14. What women with breast cancer discuss with clinicians about risk for their adolescent daughters.

    PubMed

    Maloney, Erin; Edgerson, Shawna; Robson, Mark; Offit, Ken; Brown, Richard; Bylund, Carma; Kissane, David W

    2012-01-01

    Recorded conversations between women undergoing BRCA genetic counseling with clinicians (N = 16) and follow-up consultation letters (N = 16) were analyzed to determine how and when communicating genetic risk information to women's adolescent daughters is discussed. Themes from conversations included mothers' worries about their daughters, perceptions of their daughters' coping, educational information, and clinicians' willingness or reluctance to communicate directly with daughters about their genetic risk. Letters referred to daughters when informing mothers about autosomal dominant inheritance patterns, psychosocial considerations, and screening recommendations. Results inform the value of educating mothers about how they might discuss these issues with their adolescent daughters.

  15. Carbon onions as nanoscopic pressure cells for diamond formation

    NASA Astrophysics Data System (ADS)

    Banhart, F.; Ajayan, P. M.

    1996-08-01

    SPHERICAL particles of carbon consisting of concentric graphite-like shells ('carbon onions') can be formed by electron irradiation of graphitic carbon materials1,2. Here we report that, when such particles are heated to ~700 °C and irradiated with electrons, their cores can be transformed to diamond. Under these conditions the spacing between layers in the carbon onions decreases from 0.31 in the outer shells (slightly less than the 0.34-nm layer spacing of graphite) to about 0.22 nm in the core, indicating considerable compression towards the particle centres. We find that this compression allows diamond to nucleate-in effect the carbon onions act as nanoscopic pressure cells for diamond formation.

  16. Membrane tether formation from outer hair cells with optical tweezers.

    PubMed Central

    Li, Zhiwei; Anvari, Bahman; Takashima, Masayoshi; Brecht, Peter; Torres, Jorge H; Brownell, William E

    2002-01-01

    Optical tweezers were used to characterize the mechanical properties of the outer hair cell (OHC) plasma membrane by pulling tethers with 4.5-microm polystyrene beads. Tether formation force and tether force were measured in static and dynamic conditions. A greater force was required for tether formations from OHC lateral wall (499 +/- 152 pN) than from OHC basal end (142 +/- 49 pN). The difference in the force required to pull tethers is consistent with an extensive cytoskeletal framework associated with the lateral wall known as the cortical lattice. The apparent plasma membrane stiffness, estimated under the static conditions by measuring tether force at different tether length, was 3.71 pN/microm for OHC lateral wall and 4.57 pN/microm for OHC basal end. The effective membrane viscosity was measured by pulling tethers at different rates while continuously recording the tether force, and estimated in the range of 2.39 to 5.25 pN x s/microm. The viscous force most likely results from the viscous interactions between plasma membrane lipids and the OHC cortical lattice and/or integral membrane proteins. The information these studies provide on the mechanical properties of the OHC lateral wall is important for understanding the mechanism of OHC electromotility. PMID:11867454

  17. Light induced polaron formation in perovskite solar cell devices

    NASA Astrophysics Data System (ADS)

    Neukirch, Amanda; Nie, Wanyi; Blancon, Jean-Christophe; Appavoo, Kannatassen; Tsai, Hsinhan; Chhowalla, Manish; Alam, Muhammad; Sfeir, Matthew; Katan, Claudine; Even, Jacky; Crochet, Jared; Gupta, Gautum; Mohite, Aditya; Tretiak, Sergei

    The need for a low-cost, clean, and abundant source of energy has generated large amounts of research in solution processed solar cell materials. The lead halide perovskite has rapidly developed as a serious candidate for the active layer of photovoltaic devices. The efficiencies of devices made with this material have increased from 3.5% to over 20% in around 5 years. Despite the remarkable progress associated with perovskite materials, there are still fundamental questions regarding their lack of photo-stability over prolonged solar irradiation that need to be addressed. Recent experiments on photo-degradation under constant illumination have found fast self-healing by resting the device in the dark for less than 1 minute. Density functional theory and symmetry analysis show that localized charge states couple to local structural lattice distortions and methyl ammonium quasistatic configurations. Once translational symmetry is lost, additional bonding configurations become symmetry allowed, triggering localized charges in the vicinity over time under constant illumination, thus seeding the formation of macroscopic charged domains and preventing efficient charge extraction. Here we present an in-depth study of polaron formation and binding energy at the atomistic level.

  18. An improved alkaline direct formate paper microfluidic fuel cell.

    PubMed

    Galvan, Vicente; Domalaon, Kryls; Tang, Catherine; Sotez, Samantha; Mendez, Alex; Jalali-Heravi, Mehdi; Purohit, Krutarth; Pham, Linda; Haan, John; Gomez, Frank A

    2016-02-01

    Paper-based microfluidic fuel cells (MFCs) are a potential replacement for traditional FCs and batteries due to their low cost, portability, and simplicity to operate. In MFCs, separate solutions of fuel and oxidant migrate through paper due to capillary action and laminar flow and, upon contact with each other and catalyst, produce electricity. In the present work, we describe an improved microfluidic paper-based direct formate FC (DFFC) employing formate and hydrogen peroxide as the anode fuel and cathode oxidant, respectively. The dimensions of the lateral column, current collectors, and cathode were optimized. A maximum power density of 2.53 mW/cm(2) was achieved with a DFFC of surface area 3.0 cm(2) , steel mesh as current collector, 5% carbon to paint mass ratio for cathode electrode and, 30% hydrogen peroxide. The longevity of the MFC's detailed herein is greater than eight hours with continuous flow of streams. In a series configuration, the MFCs generate sufficient energy to power light-emitting diodes and a handheld calculator.

  19. The cytological changes of tobacco zygote and proembryo cells induced by beta-glucosyl Yariv reagent suggest the involvement of arabinogalactan proteins in cell division and cell plate formation

    PubMed Central

    2012-01-01

    Background In dicotyledonous plant, the first asymmetric zygotic division and subsequent several cell divisions are crucial for proembryo pattern formation and later embryo development. Arabinogalactan proteins (AGPs) are a family of extensively glycosylated cell surface proteins that are thought to have important roles in various aspects of plant growth and development, including embryogenesis. Previous results from our laboratory show that AGPs are concerned with tobacco egg cell fertilization and zygotic division. However, how AGPs interact with other factors involved in zygotic division and proembryo development remains unknown. Results In this study, we used the tobacco in vitro zygote culture system and series of meticulous cell biology techniques to investigate the roles of AGPs in zygote and proembryo cell division. For the first time, we examined tobacco proembryo division patterns detailed to every cell division. The bright-field images and statistical results both revealed that with the addition of an exogenous AGPs inhibitor, beta-glucosyl Yariv (beta-GlcY) reagent, the frequency of aberrant division increased remarkably in cultured tobacco zygotes and proembryos, and the cell plate specific locations of AGPs were greatly reduced after beta-GlcY treatment. In addition, the accumulations of new cell wall materials were also significantly affected by treating with beta-GlcY. Detection of cellulose components by Calcofluor white stain showed that strong fluorescence was located in the newly formed wall of daughter cells after the zygotic division of in vivo samples and the control samples from in vitro culture without beta-GlcY treatment; while there was only weak fluorescence in the newly formed cell walls with beta-GlcY treatment. Immunocytochemistry examination with JIM5 and JIM7 respectively against the low- and high-esterified pectins displayed that these two pectins located in opposite positions of zygotes and proembryos in vivo and the polarity was

  20. The cytological changes of tobacco zygote and proembryo cells induced by beta-glucosyl Yariv reagent suggest the involvement of arabinogalactan proteins in cell division and cell plate formation.

    PubMed

    Yu, Miao; Zhao, Jie

    2012-08-01

    In dicotyledonous plant, the first asymmetric zygotic division and subsequent several cell divisions are crucial for proembryo pattern formation and later embryo development. Arabinogalactan proteins (AGPs) are a family of extensively glycosylated cell surface proteins that are thought to have important roles in various aspects of plant growth and development, including embryogenesis. Previous results from our laboratory show that AGPs are concerned with tobacco egg cell fertilization and zygotic division. However, how AGPs interact with other factors involved in zygotic division and proembryo development remains unknown. In this study, we used the tobacco in vitro zygote culture system and series of meticulous cell biology techniques to investigate the roles of AGPs in zygote and proembryo cell division. For the first time, we examined tobacco proembryo division patterns detailed to every cell division. The bright-field images and statistical results both revealed that with the addition of an exogenous AGPs inhibitor, beta-glucosyl Yariv (beta-GlcY) reagent, the frequency of aberrant division increased remarkably in cultured tobacco zygotes and proembryos, and the cell plate specific locations of AGPs were greatly reduced after beta-GlcY treatment. In addition, the accumulations of new cell wall materials were also significantly affected by treating with beta-GlcY. Detection of cellulose components by Calcofluor white stain showed that strong fluorescence was located in the newly formed wall of daughter cells after the zygotic division of in vivo samples and the control samples from in vitro culture without beta-GlcY treatment; while there was only weak fluorescence in the newly formed cell walls with beta-GlcY treatment. Immunocytochemistry examination with JIM5 and JIM7 respectively against the low- and high-esterified pectins displayed that these two pectins located in opposite positions of zygotes and proembryos in vivo and the polarity was not affected by

  1. ZO-1 controls endothelial adherens junctions, cell-cell tension, angiogenesis, and barrier formation.

    PubMed

    Tornavaca, Olga; Chia, Minghao; Dufton, Neil; Almagro, Lourdes Osuna; Conway, Daniel E; Randi, Anna M; Schwartz, Martin A; Matter, Karl; Balda, Maria S

    2015-03-16

    Intercellular junctions are crucial for mechanotransduction, but whether tight junctions contribute to the regulation of cell-cell tension and adherens junctions is unknown. Here, we demonstrate that the tight junction protein ZO-1 regulates tension acting on VE-cadherin-based adherens junctions, cell migration, and barrier formation of primary endothelial cells, as well as angiogenesis in vitro and in vivo. ZO-1 depletion led to tight junction disruption, redistribution of active myosin II from junctions to stress fibers, reduced tension on VE-cadherin and loss of junctional mechanotransducers such as vinculin and PAK2, and induced vinculin dissociation from the α-catenin-VE-cadherin complex. Claudin-5 depletion only mimicked ZO-1 effects on barrier formation, whereas the effects on mechanotransducers were rescued by inhibition of ROCK and phenocopied by JAM-A, JACOP, or p114RhoGEF down-regulation. ZO-1 was required for junctional recruitment of JACOP, which, in turn, recruited p114RhoGEF. ZO-1 is thus a central regulator of VE-cadherin-dependent endothelial junctions that orchestrates the spatial actomyosin organization, tuning cell-cell tension, migration, angiogenesis, and barrier formation.

  2. Cortisol response patterns in depressed women and their healthy daughters at risk: Comparison with healthy women and their daughters.

    PubMed

    Gonul, Ali Saffet; Cetinkalp, Sevki; Tunay, Sebnem; Polat, Irmak; Simsek, Fatma; Aksoy, Burcu; Kizilates, Gozde; Erdogan, Yigit; Coburn, Kerry L

    2017-02-01

    A dysfunctional hypothalamic pituitary adrenal (HPA) axis is widely accepted as a significant pathophysiological aspect of Major Depressive Disorder (MDD). Despite studies suggesting that a dysfunctional HPA axis might be present before the clinical syndrome becomes apparent, the functioning of the HPA axis in high-risk populations has not been well defined. The aim of the present study was to investigate the HPA axis functioning of mothers suffering from MDD and their healthy daughters compared to age- and sex-matched healthy controls. This design allowed a comparison of HPA axis functional differences among daughter and mother groups. HPA axis function was evaluated with a modified dexamethasone/corticotropin-releasing hormone (Dex/CRH) test, which was performed after obtaining the diurnal adrenocorticotropic hormone (ACTH) and cortisol values at 8:00, 16:00, and 23:00 h. We found that MDD mothers and their daughters had low morning cortisol and the MDD mothers additionally had low-morning ACTH compared with controls. Dexamethasone suppressed both cortisol and ACTH in all groups and subsequent HPA axis stimulation by CRH-evoked a lower cortisol response but a higher ACTH response among subjects with MDD mothers. Although high-risk daughters had comparable cortisol levels after CRH infusion, the AUC for ACTH was greater than those of controls. These patterns of results suggest that multiple level HPA dysfunctions are present in both MDD patients and their high-risk carrying daughters. However, insufficient cortisol secretion was only present in MDD mothers, while the daughters could compensate cortisol levels during CRH challenge. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Micronucleus formation induced by dielectric barrier discharge plasma exposure in brain cancer cells

    NASA Astrophysics Data System (ADS)

    Kaushik, Nagendra K.; Uhm, Hansup; Ha Choi, Eun

    2012-02-01

    Induction of micronucleus formation (cytogenetic damage) in brain cancer cells upon exposure of dielectric barrier discharge plasma has been investigated. We have investigated the influence of exposure and incubation times on T98G brain cancer cells by using growth kinetic, clonogenic, and micronucleus formation assay. We found that micronucleus formation rate directly depends on the plasma exposure time. It is also shown that colony formation capacity of cells has been inhibited by the treatment of plasma at all doses. Cell death and micronucleus formation are shown to be significantly elevated by 120 and 240 s exposure of dielectric barrier discharge plasma.

  4. Human germ cell formation in xenotransplants of induced pluripotent stem cells carrying X chromosome aneuploidies

    PubMed Central

    Dominguez, Antonia A.; Chiang, H. Rosaria; Sukhwani, Meena; Orwig, Kyle E.; Reijo Pera, Renee A.

    2014-01-01

    Turner syndrome is caused by complete or partial loss of the second sex chromosome and is characterized by spontaneous fetal loss in >90% of conceptions. Survivors possess an array of somatic and germline clinical characteristics. Induced pluripotent stem cells (iPSCs) offer an opportunity for insight into genetic requirements of the X chromosome linked to Turner syndrome. We derived iPSCs from Turner syndrome and control individuals and examined germ cell development as a function of X chromosome composition. We demonstrate that two X chromosomes are not necessary for reprogramming or maintenance of pluripotency and that there are minimal differences in gene expression, at the single cell level, linked to X chromosome aneuploidies. Formation of germ cells, as assessed in vivo through a murine xenotransplantation model, indicated that undifferentiated iPSCs, independent of X chromosome composition, are capable of forming germ-cell-like cells (GCLCs) in vivo. In combination with clinical data regarding infertility in women with X chromosome aneuploidies, results suggest that two intact X chromosomes are not required for human germ cell formation, qualitatively or quantitatively, but rather are likely to be required for maintenance of human germ cells to adulthood. PMID:25242416

  5. Human germ cell formation in xenotransplants of induced pluripotent stem cells carrying X chromosome aneuploidies.

    PubMed

    Dominguez, Antonia A; Chiang, H Rosaria; Sukhwani, Meena; Orwig, Kyle E; Reijo Pera, Renee A

    2014-09-22

    Turner syndrome is caused by complete or partial loss of the second sex chromosome and is characterized by spontaneous fetal loss in >90% of conceptions. Survivors possess an array of somatic and germline clinical characteristics. Induced pluripotent stem cells (iPSCs) offer an opportunity for insight into genetic requirements of the X chromosome linked to Turner syndrome. We derived iPSCs from Turner syndrome and control individuals and examined germ cell development as a function of X chromosome composition. We demonstrate that two X chromosomes are not necessary for reprogramming or maintenance of pluripotency and that there are minimal differences in gene expression, at the single cell level, linked to X chromosome aneuploidies. Formation of germ cells, as assessed in vivo through a murine xenotransplantation model, indicated that undifferentiated iPSCs, independent of X chromosome composition, are capable of forming germ-cell-like cells (GCLCs) in vivo. In combination with clinical data regarding infertility in women with X chromosome aneuploidies, results suggest that two intact X chromosomes are not required for human germ cell formation, qualitatively or quantitatively, but rather are likely to be required for maintenance of human germ cells to adulthood.

  6. Increased human hybridoma formation by electrofusion of human B cells with heteromyeloma SPAM-8 cells.

    PubMed

    Panova, I; Gustafsson, B

    1995-06-01

    A fusion protocol was designed for the optimal production of hybridomas following electrofusion of human B cells with cells of the heteromyeloma fusion partner SPAM-8. Peripheral blood lymphocytes showed an average fusion efficiency of 0.4 x 10(-4) whereas Epstein-Barr virus-transformed B cells showed fusion efficiencies ranging from 6.2 x 10(-4) to 9.0 x 10(-4). Similar results were obtained with bone marrow-derived lymphocytes. Trypsin treatment of the cells prior to electrofusion further increased the fusion efficiency to 12.3 x 10(-4). In comparison, conventional polyethylene glycol-induced fusion resulted in a fusion efficiency of 0.8 x 10(-4). Thus, electrofusion of human B cells with SPAM-8 heteromyeloma cells introduced a 15-fold increase in hybridoma formation as compared to the conventional fusion method.

  7. Myosin II-mediated cell shape changes and cell intercalation contribute to primitive streak formation

    PubMed Central

    Song, Feifei; Sang, Helen M.; Martin, René; Knölker, Hans-Joachim; MacDonald, Michael P; Weijer, Cornelis J

    2016-01-01

    Primitive streak formation in the chick embryo involves large scale highly coordinated flows of over 100.000 cells in the epiblast. These large scale tissue flows and deformations can be correlated with specific anisotropic cell behaviours in the forming mesendoderm through a combined light-sheet microscopy and computational analysis. Relevant behaviours include apical contraction, elongation along the apical-basal axis followed by ingression as well as asynchronous directional cell intercalation of small groups of mesendoderm cells. Cell intercalation is associated with sequential, directional contraction of apical junctions, the onset, localisation and direction of which correlate strongly with the appearance of active Myosin II cables in aligned apical junctions in neighbouring cells. Use of a class specific Myosin inhibitors and gene specific knockdowns show that apical contraction and intercalation are Myosin II dependent and also reveal critical roles for Myosin I and Myosin V family members in the assembly of junctional Myosin II cables. PMID:25812521

  8. Hyaluronan cable formation by ocular trabecular meshwork cells.

    PubMed

    Sun, Ying Ying; Keller, Kate E

    2015-10-01

    :polycytidylic acid (polyI:C), a potent inducer of HA cables, and outflow rates were monitored for 72 h. PolyI:C had no significant effect on outflow resistance in porcine anterior segments perfused at physiological pressure. Collectively, HAS gene expression, HA concentration and configuration are differentially modified in response to several treatments that induce ECM remodeling in TM cells. In ocular TM cells, our data suggests that the most important determinant of HA cable formation appears to be the ratio of HA chains produced by the different HAS genes. However, the act of rearranging pericellular HA into cable-like structures does not appear to influence aqueous outflow resistance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Membrane electrolytic cell for minimizing hypochlorite and chlorate formation

    SciTech Connect

    Fair, D. L.; Justice, D. D.; Woodard Jr., K. E.

    1985-07-09

    An electrolytic cell for the electrolysis of an alkali metal chloride brine is comprised of an anode compartment and a cathode compartment separated by a cation exchange membrane. The anode is comprised of an unflattened expanded structure of a valve metal selected from the group consisting of titanium, tantalum, niobium, and alloys thereof. At least one side of the anode has as the electrochemically active surface an electrodeposited layer of a valve metal oxide. A plurality of cracks traverse the electrodeposited layer and a coating of a platinum metal group oxide covers the electrodeposited layer and substantially fills the cracks. The cationic exchange membrane is comprised of a laminated structure having a first surface adapted to contact an anolyte in which the ion exchange groups are predominately sulfonic acid groups. The first surface is also in contact with the electrochemically active surface of the anode. A second surface of the cation exchange membrane, adapted to contact a catholyte, has ion exchange groups which are predominately carboxylic acid groups. The cathode positioned in the cathode compartment is spaced apart from the cation exchange membrane. The cell operates with both a low chlorine overvoltage and a low oxygen overvoltage. During electrolysis of alkali metal chloride brines, the formation of hypochlorite and chlorate ions is minimized and the alkali metal hydroxides produced have low chlorate concentrations and are suitable for use without further treatment in chlorate-sensitive applications. Spent brine treatment is simplified and at reduced costs.

  10. Cartilage formation in the CELLS 'double bubble' hardware

    NASA Technical Reports Server (NTRS)

    Duke, P. J.; Arizpe, Jorge; Montufar-Solis, Dina

    1991-01-01

    The CELLS experiment scheduled to be flown on the first International Microgravity Laboratory is designed to study the effect of microgravity on the cartilage formation, by measuring parameters of growth in a differentiating cartilage cell culture. This paper investigates the conditions for this experiment by studying cartilage differentiation in the 'bubble exchange' hardware with the 'double bubble' design in which the bubbles are joined by a flange which also overlays the gasket. Four types of double bubbles (or double gas permeable membranes) were tested: injection-molded bubbles 0.01- and 0.005-in. thick, and compression molded bubbles 0.015- and 0.01-in. thick. It was found that double bubble membranes of 0.005- and 0.010-in. thickness supported cartilage differentiation, while the 0.015-in. bubbles did not. It was also found that nodule count, used in this study as a parameter, is not the best measure of the amount of cartilage differentiation.

  11. Cartilage formation in the CELLS 'double bubble' hardware

    NASA Technical Reports Server (NTRS)

    Duke, P. J.; Arizpe, Jorge; Montufar-Solis, Dina

    1991-01-01

    The CELLS experiment scheduled to be flown on the first International Microgravity Laboratory is designed to study the effect of microgravity on the cartilage formation, by measuring parameters of growth in a differentiating cartilage cell culture. This paper investigates the conditions for this experiment by studying cartilage differentiation in the 'bubble exchange' hardware with the 'double bubble' design in which the bubbles are joined by a flange which also overlays the gasket. Four types of double bubbles (or double gas permeable membranes) were tested: injection-molded bubbles 0.01- and 0.005-in. thick, and compression molded bubbles 0.015- and 0.01-in. thick. It was found that double bubble membranes of 0.005- and 0.010-in. thickness supported cartilage differentiation, while the 0.015-in. bubbles did not. It was also found that nodule count, used in this study as a parameter, is not the best measure of the amount of cartilage differentiation.

  12. The Good Daughter Dilemma: Latinas Managing Family and School Demands

    ERIC Educational Resources Information Center

    Espinoza, Roberta

    2010-01-01

    This study documents strategies employed by Latina doctoral graduate students to balance family relationships with the demands of school to maintain their status of a "good daughter". In-depth interviews reveal some women integrate family and school by explaining the demands placed on them to enlist support while others keep their two social…

  13. Discovering and Constructing Our Identities: Reading "The Favorite Daughter"

    ERIC Educational Resources Information Center

    Elijah, Rosebud

    2014-01-01

    For everyone--children, parents, teachers--who have experienced instances in their lives where they have been teased, alienated, isolated, shunned, Allen Say gives us the beautifully illustrated book "The Favorite Daughter." In this book (a Notable Social Studies Trade Book for 2013), author and illustrator Say wraps and unwraps issues…

  14. Nathaniel Hawthorne's Garden of Eden Story: "Rappaccini's Daughter."

    ERIC Educational Resources Information Center

    Meixner, Linda L.

    1990-01-01

    Presents a four-day lesson plan for secondary U.S. literature or Bible-and-literature classes, using the Garden of Eden story and Nathaniel Hawthorne's "Rappaccini's Daughter." Identifies objectives, materials, procedure, and evaluation measures. Develops students' ability to discover analogies and irony in literary texts. Lists teacher…

  15. Nathaniel Hawthorne's Garden of Eden Story: "Rappaccini's Daughter."

    ERIC Educational Resources Information Center

    Meixner, Linda L.

    1990-01-01

    Presents a four-day lesson plan for secondary U.S. literature or Bible-and-literature classes, using the Garden of Eden story and Nathaniel Hawthorne's "Rappaccini's Daughter." Identifies objectives, materials, procedure, and evaluation measures. Develops students' ability to discover analogies and irony in literary texts. Lists teacher…

  16. Discovering and Constructing Our Identities: Reading "The Favorite Daughter"

    ERIC Educational Resources Information Center

    Elijah, Rosebud

    2014-01-01

    For everyone--children, parents, teachers--who have experienced instances in their lives where they have been teased, alienated, isolated, shunned, Allen Say gives us the beautifully illustrated book "The Favorite Daughter." In this book (a Notable Social Studies Trade Book for 2013), author and illustrator Say wraps and unwraps issues…

  17. Dissident Daughters? The Psychic Life of Class Inheritance

    ERIC Educational Resources Information Center

    Hey, Valerie; George, Rosalyn

    2013-01-01

    This paper arose through a chance meeting between the two authors who are feminist mothers of teenage and 20 years plus daughters. We were attending an Economic and Social Research Council-funded seminar focusing on "new femininities" in the light of post-feminism and their worth and currency within the new politics of consumption and lifestyle.…

  18. An Exploration of Mothers' Attitudes towards Their Daughters' Menarche

    ERIC Educational Resources Information Center

    Bennett, Clare; Harden, Jane

    2014-01-01

    Menarche is a significant milestone for young women, representing an important juncture between girlhood and maturation. The limited literature that exists suggests that a mother's reaction to her daughter's first periods can shape her experiences and perceptions of menstruation which, in turn, may impact on her self-image and, consequently,…

  19. Father-Daughter Incest: Data from an Anonymous Computerized Survey

    ERIC Educational Resources Information Center

    Stroebel, Sandra S.; O'Keefe, Stephen L.; Beard, Keith W.; Kuo, Shih-Ya; Swindell, Samuel V. S.; Kommor, Martin J.

    2012-01-01

    Retrospective data were entered anonymously by 1,521 adult women using computer-assisted self-interview. Nineteen were classified as victims of father-daughter incest, and 241 were classified as victims of sexual abuse by an adult other than their father before reaching 18 years of age. The remaining 1,261 served as controls. Incest victims were…

  20. Working Mothers and Daughters' Sex-Role Indentification in Brazil.

    ERIC Educational Resources Information Center

    Pasquali, Luiz; Callegari, Anna Irma

    1978-01-01

    Responses of 104 female adolescents to the Thematic Apperception Test (TAT) 7GF card and to the Scenotest (SCT) were analyzed in order to determine the influence of the mother's place of work (at home or away) and her job satisfaction on the daughter's sex-role identification. (Author/JMB)

  1. Humor in Father-Daughter Immigration Narratives of Resistance

    ERIC Educational Resources Information Center

    Gallo, Sarah

    2016-01-01

    This article draws from an ethnography on Mexican immigrant fathers and their children to examine humor in immigration narratives as acts of resistance. The analysis focuses on the devices employed by a father and daughter during their everyday talk and co-narration of an incident with police officers. Findings illustrate how the form and content…

  2. An Exploration of Mothers' Attitudes towards Their Daughters' Menarche

    ERIC Educational Resources Information Center

    Bennett, Clare; Harden, Jane

    2014-01-01

    Menarche is a significant milestone for young women, representing an important juncture between girlhood and maturation. The limited literature that exists suggests that a mother's reaction to her daughter's first periods can shape her experiences and perceptions of menstruation which, in turn, may impact on her self-image and, consequently,…

  3. Humor in Father-Daughter Immigration Narratives of Resistance

    ERIC Educational Resources Information Center

    Gallo, Sarah

    2016-01-01

    This article draws from an ethnography on Mexican immigrant fathers and their children to examine humor in immigration narratives as acts of resistance. The analysis focuses on the devices employed by a father and daughter during their everyday talk and co-narration of an incident with police officers. Findings illustrate how the form and content…

  4. Hoping for a Phoenix: Shanghai Fathers and Their Daughters

    ERIC Educational Resources Information Center

    Xu, Qiong; Yeung, Wei-Jun Jean

    2013-01-01

    Intergenerational relationships and gender roles in China are in transition because of ideational and structural changes resulting from social movements and policies in the past half a century. Using a mixed-methods design, we examine Shanghai fathers' involvement in their adolescent daughters' lives. In contrast to traditional stereotypes,…

  5. A Case Study of a Mother/Daughter Science Club.

    ERIC Educational Resources Information Center

    Chandler, Frances Tate; Parsons, Sharon

    This paper describes a case study of a Mother/Daughter Science Club which was established to explore the issue of adolescent girls' increasingly negative attitudes towards science and math. Data was collected on participants' (n=40, 20 pre-adolescent fifth-grade girls and their mothers) attitudes toward math and science through the use of…

  6. Dissident Daughters? The Psychic Life of Class Inheritance

    ERIC Educational Resources Information Center

    Hey, Valerie; George, Rosalyn

    2013-01-01

    This paper arose through a chance meeting between the two authors who are feminist mothers of teenage and 20 years plus daughters. We were attending an Economic and Social Research Council-funded seminar focusing on "new femininities" in the light of post-feminism and their worth and currency within the new politics of consumption and lifestyle.…

  7. Parental intention to have daughters receive the human papillomavirus vaccine

    PubMed Central

    Ogilvie, Gina S.; Remple, Valencia P.; Marra, Fawziah; McNeil, Shelly A.; Naus, Monika; Pielak, Karen L.; Ehlen, Thomas G.; Dobson, Simon R.; Money, Deborah M.; Patrick, David M.

    2007-01-01

    Background Concerns have been raised that parents may be reluctant to have their daughters receive the human papillomavirus (HPV) vaccine, because of a belief that doing so might be interpreted as condoning earlier and more frequent sexual activity. We determined intentions regarding vaccination among Canadian parents and factors that predicted parental intention to have their daughters vaccinated against HPV. Methods Parents of children 8–18 years of age, recruited from across Canada, were asked to respond to questions in the context of a grade 6, publicly funded, school-based HPV vaccine program. We performed backward logistic regression analysis to identify factors predictive of parents' intention to have their daughters vaccinated against HPV. Results Of the 1350 respondents with female children, more than 70% (73.8%; 95% confidence interval [CI] 71.5%– 76.1%) intended to have their daughters undergo vaccination against HPV. In multivariable modelling, parents who had positive attitudes toward vaccines (odds ratio [OR] 9.9, 95% CI 4.7–21.1), those who were influenced by subjective norms (OR 9.2, 95% CI 6.6–12.9), those who felt that the vaccine had limited influence on sexual behaviour (OR 3.2, 95% CI 2.2–4.6) and those who thought someone they knew was likely to get cervical cancer (OR 1.5, 95% CI 1.1–2.1) were more likely to intend that their daughters receive the HPV vaccine. Parents who were older (v. younger) (OR 0.6, 95% CI 0.4–0.8) and those who resided in British Columbia or Yukon Territory (v. Atlantic Canada) (OR 0.5, 95% CI 0.3–0.9) were less likely to intend that their daughters receive the HPV vaccine. Interpretation Most of the parents surveyed intended that their daughters would receive vaccination against HPV. Overall attitudes toward vaccines in general and toward the HPV vaccine in particular constituted the most significant predictor of parental intention with regard to vaccination. PMID:18056599

  8. Myotube formation is affected by adipogenic lineage cells in a cell-to-cell contact-independent manner.

    PubMed

    Takegahara, Yuki; Yamanouchi, Keitaro; Nakamura, Katsuyuki; Nakano, Shin-ichi; Nishihara, Masugi

    2014-05-15

    Intramuscular adipose tissue (IMAT) formation is observed in some pathological conditions such as Duchenne muscular dystrophy (DMD) and sarcopenia. Several studies have suggested that IMAT formation is not only negatively correlated with skeletal muscle mass but also causes decreased muscle contraction in sarcopenia. In the present study, we examined w hether adipocytes affect myogenesis. For this purpose, skeletal muscle progenitor cells were transfected with siRNA of PPARγ (siPPARγ) in an attempt to inhibit adipogenesis. Myosin heavy chain (MHC)-positive myotube formation was promoted in cells transfected with siPPARγ compared to that of cells transfected with control siRNA. To determine whether direct cell-to-cell contact between adipocytes and myoblasts is a prerequisite for adipocytes to affect myogenesis, skeletal muscle progenitor cells were cocultured with pre- or mature adipocytes in a Transwell coculture system. MHC-positive myotube formation was inhibited when skeletal muscle progenitor cells were cocultured with mature adipocytes, but was promoted when they were cocultured with preadipocytes. Similar effects were observed when pre- or mature adipocyte-conditioned medium was used. These results indicate that preadipocytes play an important role in maintaining skeletal muscle mass by promoting myogenesis; once differentiated, the resulting mature adipocytes negatively affect myogenesis, leading to the muscle deterioration observed in skeletal muscle pathologies. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Polymer Solar Cells: Solubility Controls Fiber Network Formation.

    PubMed

    van Franeker, Jacobus J; Heintges, Gaël H L; Schaefer, Charley; Portale, Giuseppe; Li, Weiwei; Wienk, Martijn M; van der Schoot, Paul; Janssen, René A J

    2015-09-16

    The photoactive layer of polymer solar cells is commonly processed from a four-component solution, containing a semiconducting polymer and a fullerene derivative dissolved in a solvent-cosolvent mixture. The nanoscale dimensions of the polymer-fullerene morphology that is formed upon drying determines the solar cell performance, but the fundamental processes that govern the size of the phase-separated polymer and fullerene domains are poorly understood. Here, we investigate morphology formation of an alternating copolymer of diketopyrrolopyrrole and a thiophene-phenyl-thiophene oligomer (PDPPTPT) with relatively long 2-decyltetradecyl (DT) side chains blended with [6,6]-phenyl-C71-butyric acid methyl ester. During solvent evaporation the polymer crystallizes into a fibrous network. The typical width of these fibers is analyzed by quantification of transmission electron microscopic images, and is mainly determined by the solubility of the polymer in the cosolvent and the molecular weight of the polymer. A higher molecular weight corresponds to a lower solubility and film processing results in a smaller fiber width. Surprisingly, the fiber width is not related to the drying rate or the amount of cosolvent. We have made solar cells with fiber widths ranging from 28 to 68 nm and found an inverse relation between fiber width and photocurrent. Finally, by mixing two cosolvents, we develop a ternary solvent system to tune the fiber width. We propose a model based on nucleation-and-growth which can explain these measurements. Our results show that the width of the semicrystalline polymer fibers is not the result of a frozen dynamical state, but determined by the nucleation induced by the polymer solubility.

  10. Diclofenac in Arabidopsis cells: Rapid formation of conjugates.

    PubMed

    Fu, Qiuguo; Ye, Qingfu; Zhang, Jianbo; Richards, Jaben; Borchardt, Dan; Gan, Jay

    2017-03-01

    Pharmaceutical and personal care products (PPCPs) are continuously introduced into the soil-plant system, through practices such as agronomic use of reclaimed water and biosolids containing these trace contaminants. Plants may accumulate PPCPs from soil, serving as a conduit for human exposure. Metabolism likely controls the final accumulation of PPCPs in plants, but is in general poorly understood for emerging contaminants. In this study, we used diclofenac as a model compound, and employed (14)C tracing, and time-of-flight (TOF) and triple quadruple (QqQ) mass spectrometers to unravel its metabolism pathways in Arabidopsis thaliana cells. We further validated the primary metabolites in Arabidopsis seedlings. Diclofenac was quickly taken up into A. thaliana cells. Phase I metabolism involved hydroxylation and successive oxidation and cyclization reactions. However, Phase I metabolites did not accumulate appreciably; they were instead rapidly conjugated with sulfate, glucose, and glutamic acid through Phase II metabolism. In particular, diclofenac parent was directly conjugated with glutamic acid, with acyl-glutamatyl-diclofenac accounting for >70% of the extractable metabolites after 120-h incubation. In addition, at the end of incubation, >40% of the spiked diclofenac was in the non-extractable form, suggesting extensive sequestration into cell matter. The rapid formation of non-extractable residue and dominance of diclofenac-glutamate conjugate uncover previously unknown metabolism pathways for diclofenac. In particular, the rapid conjugation of parent highlights the need to consider conjugates of emerging contaminants in higher plants, and their biological activity and human health implications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Effect of cell-substratum interaction on hemicyst formation by MDCK cells.

    PubMed

    Rabito, C A; Tchao, R; Valentich, J; Leighton, J

    1980-06-01

    On impermeable substrata MDCK cells, a cell line derived from normal dog kidney, forms a confluent monolayer that is studded with numerous hemicysts. Previous studies with this cell line suggest that thes hemicysts develop as a result of active fluid accumulation between cell sheet and substratum. However, the formation of hemicysts as a multifocal phenomenon is still unexplained. The results presented here show that the hemicysts are not only expressions of active transport of solutes and water, but also of cell-substratum interaction. The increase in number and size of the hemicyst produced by dbcAMP may be explained by a decrease in the adhesive strength to substrata produced by this compound. Moreover, when the strength of the cell-substratum adhesion was increased the number of hemicysts was reduced or abolished. On the contrary, when this strength was reduced, larger hemicysts occurred, covering practically all the area available for growth. Results from cinematographic time lapse studies, showing that 90% of the area of the monolayer is able to produce hemicysts, also suggest that hemicyst formation as a multifocal phenomenon is more an expression of local variations in cell-substratum interaction than of regional changes in transepithelial active transport.

  12. Loss of Centrobin Enables Daughter Centrioles to Form Sensory Cilia in Drosophila.

    PubMed

    Gottardo, Marco; Pollarolo, Giulia; Llamazares, Salud; Reina, Jose; Riparbelli, Maria G; Callaini, Giuliano; Gonzalez, Cayetano

    2015-08-31

    Sensory cilia are organelles that convey information to the cell from the extracellular environment. In vertebrates, ciliary dysfunction results in ciliopathies that in humans comprise a wide spectrum of developmental disorders. In Drosophila, sensory cilia are found only in the neurons of type I sensory organs, but ciliary dysfunction also has dramatic consequences in this organism because it impairs the mechanosensory properties of bristles and chaetae and leads to uncoordination, a crippling condition that causes lethality shortly after eclosion. The cilium is defined by the ciliary membrane, a protrusion of the cell membrane that envelops the core structure known as the axoneme, a microtubule array that extends along the cilium from the basal body. In vertebrates, basal body function requires centriolar distal and subdistal appendages and satellites. Because these structures are acquired through centriole maturation, only mother centrioles can serve as basal bodies. Here, we show that although centriole maturity traits are lacking in Drosophila, basal body fate is reserved to mother centrioles in Drosophila type I neurons. Moreover, we show that depletion of the daughter-centriole-specific protein Centrobin (CNB) enables daughter centrioles to dock on the cell membrane and to template an ectopic axoneme that, although structurally defective, protrudes out of the cell and is enveloped by a ciliary membrane. Conversely, basal body capability is inhibited in mother centrioles modified to carry CNB. These results reveal the crucial role of CNB in regulating basal body function in Drosophila ciliated sensory organs.

  13. Multagenicity of radon and radon daughters. Final technical report, January 1, 1993--December 31, 1996

    SciTech Connect

    Evans, H.H.

    1997-06-01

    The objective of this research was to investigate the dose-response relationship with regard to the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose-rate dependence was studied, as well as the nature of the DNA lesions. The effect of DNA repair on the lethal and mutagenic effects of exposure and on the character of the DNA lesions was investigated by comparing the response of L5178Y strains that differ in their ability to rejoin X radiation-induced DNA double strand breaks. The nature of radon/radon daughter-induced mutational lesions in human lymphoblasts was also investigated.

  14. Spheroid Formation of Hepatocarcinoma Cells in Microwells: Experiments and Monte Carlo Simulations

    PubMed Central

    Tabaei, Seyed R.; Park, Jae Hyeok; Na, Kyuhwan; Chung, Seok; Zhdanov, Vladimir P.

    2016-01-01

    The formation of spherical aggregates during the growth of cell population has long been observed under various conditions. We observed the formation of such aggregates during proliferation of Huh-7.5 cells, a human hepatocarcinoma cell line, in a microfabricated low-adhesion microwell system (SpheroFilm; formed of mass-producible silicone elastomer) on the length scales up to 500 μm. The cell proliferation was also tracked with immunofluorescence staining of F-actin and cell proliferation marker Ki-67. Meanwhile, our complementary 3D Monte Carlo simulations, taking cell diffusion and division, cell-cell and cell-scaffold adhesion, and gravity into account, illustrate the role of these factors in the formation of spheroids. Taken together, our experimental and simulation results provide an integrative view of the process of spheroid formation for Huh-7.5 cells. PMID:27571565

  15. Spheroid Formation of Hepatocarcinoma Cells in Microwells: Experiments and Monte Carlo Simulations.

    PubMed

    Wang, Yan; Kim, Myung Hee; Tabaei, Seyed R; Park, Jae Hyeok; Na, Kyuhwan; Chung, Seok; Zhdanov, Vladimir P; Cho, Nam-Joon

    2016-01-01

    The formation of spherical aggregates during the growth of cell population has long been observed under various conditions. We observed the formation of such aggregates during proliferation of Huh-7.5 cells, a human hepatocarcinoma cell line, in a microfabricated low-adhesion microwell system (SpheroFilm; formed of mass-producible silicone elastomer) on the length scales up to 500 μm. The cell proliferation was also tracked with immunofluorescence staining of F-actin and cell proliferation marker Ki-67. Meanwhile, our complementary 3D Monte Carlo simulations, taking cell diffusion and division, cell-cell and cell-scaffold adhesion, and gravity into account, illustrate the role of these factors in the formation of spheroids. Taken together, our experimental and simulation results provide an integrative view of the process of spheroid formation for Huh-7.5 cells.

  16. Self-organization and advective transport in the cell polarity formation for asymmetric cell division.

    PubMed

    Seirin Lee, Sungrim; Shibata, Tatsuo

    2015-10-07

    Anterior-Posterior (AP) polarity formation of cell membrane proteins plays a crucial role in determining cell asymmetry, which depends not only on the several genetic process but also biochemical and biophysical interactions. The mechanism of AP formation of Caenorhabditis elegans embryo is characterized into the three processes: (i) membrane association and dissociation of posterior and anterior proteins, (ii) diffusion into the membrane and cytosol, and (iii) active cortical and cytoplasmic flows induced by the contraction of the acto-myosin cortex. We explored the mechanism of symmetry breaking and AP polarity formation using self-recruitment model of posterior proteins. We found that the AP polarity pattern is established over wide range in the total mass of polarity proteins and the diffusion ratio in the cytosol to the membrane. We also showed that the advective transport in both membrane and cytosol during the establishment phase affects optimal time interval of establishment and positioning of the posterior domain, and plays a role to increase the robustness in the AP polarity formation by reducing the number of posterior domains for the sensitivity of initial conditions. We also demonstrated that a proper ratio of the total mass to cell size robustly regulate the length scale of the posterior domain.

  17. The Daughter's Disenchantment: Incest as Pedagogy in Fairy Tales and Kathryn Harrison's the Kiss

    ERIC Educational Resources Information Center

    Marshall, Elizabeth

    2004-01-01

    The Kiss, is described as a controversial memoir about father-daughter incest that disturbed the cultural silence in a "well heeled" home. The emotional and psychological terrain of the daughter's experience is discussed.

  18. In Vitro Formation of β Cell Pseudoislets Using Islet-Derived Endothelial Cells

    PubMed Central

    Spelios, Michael G.; Kenna, Lauren A.; Wall, Bonnie; Akirav, Eitan M.

    2013-01-01

    β cell pseudoislets (PIs) are used for the in vitro study of β-cells in a three-dimensional (3-D) configuration. Current methods of PI induction require unique culture conditions and extensive mechanical manipulations. Here we report a novel co-culture system consisting of high passage β-cells and islet-derived endothelial cells (iECs) that results in a rapid and spontaneous formation of free-floating PIs. PI structures were formed as early as 72 h following co-culture setup and were preserved for more than 14 d. These PIs, composed solely of β-cells, were similar in size to that of native islets and showed an increased percentage of proinsulin-positive cells, increased insulin gene expression in response to glucose stimulation, and restored glucose-stimulated insulin secretion when compared to β-cells cultured as monolayers. Key extracellular matrix proteins that were absent in β-cells cultured alone were deposited by iECs on PIs and were found in and around the PIs. iEC-induced PIs are a readily available tool for examining β cell function in a native 3-D configuration and can be used for examining β-cell/iEC interactions in vitro. PMID:24015227

  19. In vivo differentiation of induced pluripotent stem cells into neural stem cells by chimera formation.

    PubMed

    Choi, Hyun Woo; Hong, Yean Ju; Kim, Jong Soo; Song, Hyuk; Cho, Ssang Gu; Bae, Hojae; Kim, Changsung; Byun, Sung June; Do, Jeong Tae

    2017-01-01

    Like embryonic stem cells, induced pluripotent stem cells (iPSCs) can differentiate into all three germ layers in an in vitro system. Here, we developed a new technology for obtaining neural stem cells (NSCs) from iPSCs through chimera formation, in an in vivo environment. iPSCs contributed to the neural lineage in the chimera, which could be efficiently purified and directly cultured as NSCs in vitro. The iPSC-derived, in vivo-differentiated NSCs expressed NSC markers, and their gene-expression pattern more closely resembled that of fetal brain-derived NSCs than in vitro-differentiated NSCs. This system could be applied for differentiating pluripotent stem cells into specialized cell types whose differentiation protocols are not well established.

  20. In vivo differentiation of induced pluripotent stem cells into neural stem cells by chimera formation

    PubMed Central

    Choi, Hyun Woo; Hong, Yean Ju; Kim, Jong Soo; Song, Hyuk; Cho, Ssang Gu; Bae, Hojae; Kim, Changsung; Byun, Sung June; Do, Jeong Tae

    2017-01-01

    Like embryonic stem cells, induced pluripotent stem cells (iPSCs) can differentiate into all three germ layers in an in vitro system. Here, we developed a new technology for obtaining neural stem cells (NSCs) from iPSCs through chimera formation, in an in vivo environment. iPSCs contributed to the neural lineage in the chimera, which could be efficiently purified and directly cultured as NSCs in vitro. The iPSC-derived, in vivo-differentiated NSCs expressed NSC markers, and their gene-expression pattern more closely resembled that of fetal brain-derived NSCs than in vitro-differentiated NSCs. This system could be applied for differentiating pluripotent stem cells into specialized cell types whose differentiation protocols are not well established. PMID:28141814

  1. Energy deposition and radiation quality of radon and radon daughters. Final report

    SciTech Connect

    Karam, L.R.; Caswell, R.S.

    1996-09-09

    This program was aimed at creating a quantitative physical description, at the micrometer and nanometer levels, of the physical interactions of the alpha particles from radon and its daughters with cells at risk in the bronchial epithelium. The authors calculated alpha-particle energy spectra incident upon the cells and also energy deposition spectra in micrometer- and nanometer-sized sites as a function of cell depth, site size, airway diameter, activities of {sup 218}Po and {sup 214}Po, and other parameters. These data are now being applied, using biophysical models of radiation effects, to predict cell killing, mutations, and cell transformation. The model predictions are then compared to experimental biophysical, biochemical, and biological information. These studies contribute to a detailed understanding of the mechanisms of the biological effectiveness of the radiations emitted by radon and its progeny.

  2. Barriers to physical activity: qualitative data on caregiver-daughter perceptions and practices.

    PubMed

    Gordon-Larsen, Penny; Griffiths, Paula; Bentley, Margaret E; Ward, Dianne S; Kelsey, Kristine; Shields, Kenitra; Ammerman, Alice

    2004-10-01

    There is little research on household and physical environment barriers to physical activity, particularly in minority populations at high risk for obesity and inactivity. Few studies include data on caregiver and daughter dyads. Formative data were used to develop intervention strategies and pathways for the Girls Rule! obesity prevention intervention, in under-studied high-risk pre-adolescents. Participants included 12 African-American girls (mean age 7.8 years) and their 11 primary female caregivers (mean age 41.8 years)--eight mother-daughter dyads and three grandmother-granddaughter dyads--for a total of 51 interviews across 23 participants interviewed from April to October 2000.A qualitative approach was used for 51 semistructured in-depth interviews with 11 dyads (female caregiver and girl), consisting of up to three interviews per respondent (mean=2.4 interviews per respondent). Interviews were transcribed, coded, and systematically analyzed between January 2002 and January 2003 to identify recurrent patterns and themes related to physical activity. Findings indicate clear preference of the girls for sedentary, rather than active, behaviors. Caregivers were unaware of the amount of TV viewed and found positive benefits of TV viewing, including safe supervision of their daughters. Barriers to physical activity include perceived lack of affordable and accessible recreation facilities and low caregiver motivation. Potential intervention strategies identified by respondents include walking for exercise and transportation and several low-cost, favored physical activities, such as hopscotch, jumping rope, and dance. These findings point toward several physical activity and obesity intervention strategies that can guide obesity prevention efforts.

  3. Interordinal chimera formation between medaka and zebrafish for analyzing stem cell differentiation.

    PubMed

    Hong, Ni; Chen, Songlin; Ge, Ruowen; Song, Jianxing; Yi, Meisheng; Hong, Yunhan

    2012-08-10

    Chimera formation is a standard test for pluripotency of stem cells in vivo. Interspecific chimera formation between distantly related organisms offers also an attractive approach for propagating endangered species. Parameters influencing interspecies chimera formation have remained poorly elucidated. Here, we report interordinal chimera formation between medaka and zebrafish, which separated ∼320 million years ago and exhibit a more than 2-fold difference in developmental speed. We show that, on transplantation into zebrafish blastulae, both noncultivated blastomeres and long-term cultivated embryonic stem (ES) cells of medaka adopted the zebrafish developmental program and differentiated into physiologically functional cell types including pigment cells, blood cells, and cardiomyocytes. We also show that medaka ES cells express differentiation gene markers during chimeric embryogenesis. Therefore, the evolutionary distance and different embryogenesis speeds do not produce donor-host incompatibility to compromise chimera formation between medaka and zebrafish, and molecular markers are valuable for analyzing lineage commitment and cell differentiation in interspecific chimeric embryos.

  4. Lateral inhibition-induced pattern formation controlled by the size and geometry of the cell.

    PubMed

    Seirin Lee, Sungrim

    2016-09-07

    Pattern formation in development biology is one of the fundamental processes by which cells change their functions. It is based on the communication of cells via intra- and intercellular dynamics of biochemicals. Thus, the cell is directly involved in biochemical interactions. However, many theoretical approaches describing biochemical pattern formation have usually neglected the cell's role or have simplified the subcellular process without considering cellular aspects despite the cell being the environment where biochemicals interact. On the other hand, recent experimental observations suggest that a change in the physical conditions of cell-to-cell contact can result in a change in cell fate and tissue patterning in a lateral inhibition system. Here we develop a mathematical model by which biochemical dynamics can be directly observed with explicitly expressed cell structure and geometry in higher dimensions, and reconsider pattern formation by lateral inhibition of the Notch-Delta signaling pathway. We explore how the physical characteristic of cell, such as cell geometry or size, influences the biochemical pattern formation in a multi-cellular system. Our results suggest that a property based on cell geometry can be a novel mechanism for symmetry breaking inducing cell asymmetry. We show that cell volume can critically influence cell fate determination and pattern formation at the tissue level, and the surface area of the cell-to-cell contact can directly affect the spatial range of patterning.

  5. Latina Daughters' Childbearing Attitudes: The Role of Maternal Expectations and Education Communication

    ERIC Educational Resources Information Center

    Mireles-Rios, Rebeca; Romo, Laura F.

    2014-01-01

    Adolescent girls' and their mothers' expectations for their daughters' college attainment, mother-daughter communication about education, and daughters' early childbearing attitudes were examined in 146 U.S.-raised Latina girls (mean age = 14.4 years) and their mostly immigrant mothers. Through structural equation modeling, we…

  6. Mother and Daughter Perceptions of Their Relationships: The Influence of Adolescent Pregnancy Status.

    ERIC Educational Resources Information Center

    Townsend, Janet K.; Worobey, John

    1987-01-01

    Examined perceived relationships between 95 mothers and their adolescent daughters to determine if there was a significant difference in mother-daughter relationshhip as perceived by pregnant versus nonpregnant adolescents, and whether mothers of these two groups differed in their feelings for their daughters. Found no striking differences between…

  7. Homework Headaches: How I Got My Special Needs Daughter to Do Homework

    ERIC Educational Resources Information Center

    Frye, Cyndi

    2007-01-01

    In this article, the author, a graduate student in special education, relates how she got her daughter with special needs to do homework. Her daughter's temper tantrums, when asked to do her homework, ruined the whole evening for their family. The author describes her daughter's homework intervention program which she developed and implemented.…

  8. Homework Headaches: How I Got My Special Needs Daughter to Do Homework

    ERIC Educational Resources Information Center

    Frye, Cyndi

    2007-01-01

    In this article, the author, a graduate student in special education, relates how she got her daughter with special needs to do homework. Her daughter's temper tantrums, when asked to do her homework, ruined the whole evening for their family. The author describes her daughter's homework intervention program which she developed and implemented.…

  9. Daughter's Perceptions of Being Mothered by an Incest Survivor: A Phenomenological Study.

    ERIC Educational Resources Information Center

    Voth, Peggy Funk; Tutty, Leslie M.

    1999-01-01

    Presents results of an analysis on the experiences of daughters of incest survivors. Reports that daughters responded with a lack of affection toward their mothers, and had complications in differentiation and integration of a negative self-view. Notes that mother's ultimate disclosure of incest history helped the daughter offset difficulties.…

  10. Latina Daughters' Childbearing Attitudes: The Role of Maternal Expectations and Education Communication

    ERIC Educational Resources Information Center

    Mireles-Rios, Rebeca; Romo, Laura F.

    2014-01-01

    Adolescent girls' and their mothers' expectations for their daughters' college attainment, mother-daughter communication about education, and daughters' early childbearing attitudes were examined in 146 U.S.-raised Latina girls (mean age = 14.4 years) and their mostly immigrant mothers. Through structural equation modeling, we…

  11. A Tale of Mother and Daughter

    PubMed Central

    2010-01-01

    Loving science and nature and being a scientist can be very different, yet the two are so intertwined in a scientist's life that you will certainly experience both aspects. This essay presents my perspective on how, as one who loves science and nature, I came to fall in love with centrosome behavior in stem cells and how I came to run a lab as a scientist. When I started, there was a big gap between my love for science and my experience as a scientist. I filled this gap by learning a “laid-back confidence.” PMID:20048256

  12. Formation of thin walled ceramic solid oxide fuel cells

    DOEpatents

    Claar, Terry D.; Busch, Donald E.; Picciolo, John J.

    1989-01-01

    To reduce thermal stress and improve bonding in a high temperature monolithic solid oxide fuel cell (SOFC), intermediate layers are provided between the SOFC's electrodes and electrolyte which are of different compositions. The intermediate layers are comprised of a blend of some of the materials used in the electrode and electrolyte compositions. Particle size is controlled to reduce problems involving differential shrinkage rates of the various layers when the entire structure is fired at a single temperature, while pore formers are provided in the electrolyte layers to be removed during firing for the formation of desired pores in the electrode layers. Each layer includes a binder in the form of a thermosetting acrylic which during initial processing is cured to provide a self-supporting structure with the ceramic components in the green state. A self-supporting corrugated structure is thus formed prior to firing, which the organic components of the binder and plasticizer removed during firing to provide a high strength, high temperature resistant ceramic structure of low weight and density.

  13. Daughter neglect, women's work, and marriage: Pakistan and Bangladesh compared.

    PubMed

    Miller, B D

    1984-01-01

    This article looks at juvenile sex ratios, juvenile mortality, women's work roles and marriage patterns in Pakistan and bangladesh in order to assess whether patterns previously observed in India, namely, daughter neglect in the northwest and equal juvenile sex ratios in the eastern part of the country, are carried over into the 2 adjacent nations, Pakistan and Bangladesh, respectively. The Indian study indicates that nationwide sex ratio data, sample survey data on childhood mortality, longitudinal population records in several locations and ethonographic evidence all point to inequalities in mortality as the prime cause of unbalanced sex ratios. The juvenile sex ratios of Pakistan and Bangladesh are very different from 1 another. Whereas there are no regional contrasts among juvenile sex ratios within Bangladesh, it is greater within Pakistan. Sex ratio data correspond roughly to what the mortality data indicate in terms of the contrast between Pakistan and Bangladesh. The evidence on juvenile mortality in both countries is too scant to support an airtight argument that juvenile females in Pakistan have much higher mortality rates than boys, while mortality rates are more balanced in Bangladesh. But the existing evidence clearly points to that conclusion. The immediate causes of the greater sex-differential mortality in Pakistan cannot be documented in the available ethnographic literature. Biased allocation of food, medical care, and love might be operating. Looking at the economic and sociocultural complex that promotes much differences between Pakistan and Bangladesh, it is argued that, in both countries, class-based variations in both women's work and marriage patterns exist and are important. It is hypothesized that females in Pakistan are little valued for agricultural labor, and pose an economic liability on their families who need to provide a large dowry with her marriage to compensate for the daughter's low economic utility to the agrucultural workforce

  14. The contribution of cell-cell signaling and motility to bacterial biofilm formation

    PubMed Central

    Shrout, Joshua D.; Tolker-Nielsen, Tim; Givskov, Michael; Parsek, Matthew R.

    2011-01-01

    Many bacteria grow attached to a surface as biofilms. Several factors dictate biofilm formation, including responses by the colonizing bacteria to their environment. Here we review how bacteria use cell-cell signaling (also called quorum sensing) and motility during biofilm formation. Specifically, we describe quorum sensing and surface motility exhibited by the bacterium Pseudomonas aeruginosa, a ubiquitous environmental organism that acts as an opportunistic human pathogen in immunocompromised individuals. P. aeruginosa uses acyl-homoserine lactone signals during quorum sensing to synchronize gene expression important to the production of polysaccharides, rhamnolipid, and other virulence factors. Surface motility affects the assembly and architecture of biofilms, and some aspects of motility are also influenced by quorum sensing. While some genes and their function are specific to P. aeruginosa, many aspects of biofilm development can be used as a model system to understand how bacteria differentially colonize surfaces. PMID:22053126

  15. Effect of uneven red cell influx on formation of cell-free layer in small venules.

    PubMed

    Namgung, Bumseok; Kim, Sangho

    2014-03-01

    This study examined how the uneven influx of red blood cells (RBCs) from feeding vessels influences formation of cell-free layer (CFL) in the downstream vessel of a venular bifurcation. Spatio-temporal variations of the CFL width along the downstream vessel (19-41-μm inner diameter, D) were determined at 0.5D intervals from 0.5D to 3.0D away from the bifurcation. Upstream flow conditions were quantified by the ratio of volume flow rates (Q*=Q(High)/Q(Low)) between high flow (Q(High)) and low flow feeding (Q(Low)) vessels. The RBC aggregation level in the rats was adjusted to be at healthy human levels by infusing Dextran 500. Our results suggested that the CFL formation process could be seen only from 2.0D away from the bifurcating point. The mean CFL width at the wall adjacent to the feeding vessel with a higher flow rate was consistently greater than that at the opposite wall, leading to an asymmetric CFL formation in the vessel. A positive relation (P<0.05) between the asymmetry of the CFL width and the volume flow rate ratio (Q*) was found. Our numerical prediction showed that flow resistance in the venular network could be significantly increased by the asymmetric formation of CFL downstream and this effect might become more pronounced under pathological flow conditions such as hyper-aggregating and/or low shear conditions.

  16. Expression of an accessory cell phenotype by hairy cells during lymphocyte colony formation in agar culture.

    PubMed

    Farcet, J P; Gourdin, M F; Testa, U; Andre, C; Jouault, H; Reyes, F

    1983-01-01

    Human T lymphocytes require the cooperation of accessory cells to generate lymphocyte colonies in agar culture under PHA stimulation. Various hairy cell enriched fractions, as well as normal monocytes, have been found to be able to initiate colony formation by normal lymphocytes. Leukemic monocytes from CMML patients were also effective, but not the leukemic lymphocytes from CLL patients. The phenotype expressed by HC in agar colonies was further studied using cell surface and enzymatic markers. We have concluded that HC in agar culture in the presence of both normal T lymphocytes and PHA lose the B phenotype that they express in vivo and function like an accessory cell in contrast to normal or leukemic B lymphocytes.

  17. Commensal Microbiota and CD8+ T Cells Shape the Formation of Invariant NKT Cells

    PubMed Central

    Wei, Bo; Wingender, Gerhard; Fujiwara, Daisuke; Chen, Diana YuHui; McPherson, Michael; Brewer, Sarah; Borneman, James; Kronenberg, Mitchell; Braun, Jonathan

    2012-01-01

    Commensal bacteria play an important role in formation of the immune system, but the mechanisms involved are incompletely understood. In this study, we analyze CD1d-restricted invariant NKT (iNKT) cells in germfree mice and in two colonies of C57BL/6 mice termed conventional flora and restricted flora (RF), stably bearing commensal microbial communities of diverse but distinct composition. In germfree mice, iNKT cells were moderately reduced, suggesting that commensal microbiota were partially required for the antigenic drive in maintaining systemic iNKT cells. Surprisingly, even greater depletion of iNKT cell population occurred in RF mice. This was in part attributable to reduced RF levels of intestinal microbial taxa (Sphingomonas spp.) known to express antigenic glycosphingolipid products. However, memory and activated CD8+ T cells were also expanded in RF mice, prompting us to test whether CD8+ T cell activity might be further depleting iNKT cells. Indeed, iNKT cell numbers were restored in RF mice bearing the CD8α−/− genotype or in adult wild-type RF mice acutely depleted with anti-CD8 Ab. Moreover, iNKT cells were restored in RF mice bearing the Prf1−/− phenotype, a key component of cytolytic function. These findings indicate that commensal microbiota, through positive (antigenic drive) and negative (cytolytic depletion by CD8+ T cells) mechanisms, profoundly shape the iNKT cell compartment. Because individuals greatly vary in the composition of their microbial communities, enteric microbiota may play an important epigenetic role in the striking differences in iNKT cell abundance in humans and therefore in their potential contribution to host immune status. PMID:20048124

  18. Co-culturing of follicles with interstitial cells in collagen gel reproduce follicular development accompanied with theca cell layer formation

    PubMed Central

    2011-01-01

    Background The mechanism of theca cell layer formation in mammalian ovaries has not been elucidated; one reason is that there is no follicle culture system that can reproduce theca cell layer formation in vitro. Therefore, a three-dimensional follicle culture system that can reproduce theca cell layer formation is required. Methods A collagen gel was used in the follicle culture system. To determine the optimum conditions for follicle culture that can reproduce theca cell layer formation, the effects of hormonal treatment and cell types co-cultured with follicles were examined. In addition, immunohistochemistry was used to examine the properties of the cell layers formed in the outermost part of follicles. Results Follicles maintained a three-dimensional shape and grew in collagen gel. By adding follicle-stimulating hormone (FSH) and co-culturing with interstitial cells, the follicles grew well, and cell layers were formed in the outermost part of follicles. Immunohistochemistry confirmed that the cells forming the outermost layers of the follicles were theca cells. Conclusion In this study, follicle culture system that can reproduce theca cell layer formation in vitro was established. In our opinion, this system is suitable for the analysis of theca cell layer formation and contributes to our understanding of the mechanisms of folliculogenesis. PMID:22176614

  19. Cytokinesis defines a spatial landmark for hepatocyte polarization and apical lumen formation

    PubMed Central

    Wang, Ting; Yanger, Kilangsungla; Stanger, Ben Z.; Cassio, Doris; Bi, Erfei

    2014-01-01

    ABSTRACT By definition, all epithelial cells have apical–basal polarity, but it is unclear how epithelial polarity is acquired and how polarized cells engage in tube formation. Here, we show that hepatocyte polarization is linked to cytokinesis using the rat hepatocyte cell line Can 10. Before abscission, polarity markers are delivered to the site of cell division in a strict spatiotemporal order. Immediately after abscission, daughter cells remain attached through a unique disc-shaped structure, which becomes the site for targeted exocytosis, resulting in the formation of a primitive bile canaliculus. Subsequently, oriented cell division and asymmetric cytokinesis occur at the bile canaliculus midpoint, resulting in its equal partitioning into daughter cells. Finally, successive cycles of oriented cell division and asymmetric cytokinesis lead to the formation of a tubular bile canaliculus, which is shared by two rows of hepatocytes. These findings define a novel mechanism for cytokinesis-linked polarization and tube formation, which appears to be broadly conserved in diverse cell types. PMID:24706948

  20. Receptor-like kinase ACR4 restricts formative cell divisions in the Arabidopsis root.

    PubMed

    De Smet, Ive; Vassileva, Valya; De Rybel, Bert; Levesque, Mitchell P; Grunewald, Wim; Van Damme, Daniël; Van Noorden, Giel; Naudts, Mirande; Van Isterdael, Gert; De Clercq, Rebecca; Wang, Jean Y; Meuli, Nicholas; Vanneste, Steffen; Friml, Jirí; Hilson, Pierre; Jürgens, Gerd; Ingram, Gwyneth C; Inzé, Dirk; Benfey, Philip N; Beeckman, Tom

    2008-10-24

    During the development of multicellular organisms, organogenesis and pattern formation depend on formative divisions to specify and maintain pools of stem cells. In higher plants, these activities are essential to shape the final root architecture because the functioning of root apical meristems and the de novo formation of lateral roots entirely rely on it. We used transcript profiling on sorted pericycle cells undergoing lateral root initiation to identify the receptor-like kinase ACR4 of Arabidopsis as a key factor both in promoting formative cell divisions in the pericycle and in constraining the number of these divisions once organogenesis has been started. In the root tip meristem, ACR4 shows a similar action by controlling cell proliferation activity in the columella cell lineage. Thus, ACR4 function reveals a common mechanism of formative cell division control in the main root tip meristem and during lateral root initiation.

  1. Cell sheet transplantation of cultured mesenchymal stem cells enhances bone formation in a rat nonunion model.

    PubMed

    Nakamura, Akifumi; Akahane, Manabu; Shigematsu, Hideki; Tadokoro, Mika; Morita, Yusuke; Ohgushi, Hajime; Dohi, Yoshiko; Imamura, Tomoaki; Tanaka, Yasuhito

    2010-02-01

    Orthopedic surgeons have long been troubled by cases involving nonunion of fractured bones. This study aimed to enhance bone union by cell sheet transplantation of mesenchymal stem cells. A nonunion model was made in rat femur, and rat bone marrow cells were cultured in medium containing dexamethasone and ascorbic acid phosphate to create a cell sheet that could be scraped off as a single sheet. Cell sheets were transplanted onto fractured femurs without a scaffold in the model. X-ray and histological analysis were performed at 2, 4 and 8 weeks. Ultrasonography and biomechanical analysis were performed at 8 weeks. X-ray photographs and histological sections showed callus formation around the fracture site in the cell sheet-transplanted group (sheet group). Bone union was obtained in the sheet group at 8 weeks. By contrast, the control group (without sheet transplantation) showed nonunion of the femur. The results of pullout evaluation in the vertical direction of the femur in the sheet group were significantly better than that of the control group. Analysis of the origin of de novo formed bone using the Sry gene, which was used as a marker for donor cells, showed that transplanted cells without scaffolds could survive and differentiate into osteogenic lineage cells in vivo. These results showed that the femoral fracture in our model was completely cured by the transplantation of a cell sheet created by tissue engineering techniques. Thus, we think that cell sheet transplantation can contribute to hard tissue reconstruction in cases involving nonunion, bone defects and osteonecrosis. (c) 2009 Elsevier Inc. All rights reserved.

  2. Coping among African-American daughters caring for aging parents.

    PubMed

    Jones-Cannon, Sheila; Davis, Bertha L

    2005-01-01

    A higher proportion of African-American caregivers reported having suffered physical and mental problems because of caregiving (U. S. Department of Health & Human Services, 2005). The purpose of this study was to examine the coping strategies of African-American daughters who have functioned as caregivers. The Neuman Systems model was utilized as the framework for this study. An exploratory design utilizing qualitative and quantitative methodologies was conducted in two phases. Phase I (N = 44) consisted of a series of focus groups sessions and Phase II (N = 106) participants completed the Basic Interview Schedule Survey. Findings revealed than other groups to report dementia and stroke in their care recipients that daughters who attended support groups had increased family involvement, were religious and coped better with caregiving. This study concluded that religion gave most participants a strong tolerance for the caregiving situation and served to mediate the caregiving strain.

  3. A father marries his daughters: a case of incestuous polygamy.

    PubMed

    Myers, Wade C; Brasington, Steve J

    2002-09-01

    Polygamy is a risk factor for incest. This case report of incest and polygamy portrays the dynamics that dominated this family's identity. The father indoctrinated and groomed his biological daughter and stepdaughter for sexual gratification in a cult-like atmosphere, and secretly married both of them. He justified his acts to the family members under the guise of religion, but he later denied allegations of polygamy and sexual contact with his daughters when confronted by the authorities. Ultimately, his parental rights were terminated in family court. The authors interviewed the primary victim and reviewed extensive evidence, including videotapes of the victims talking with detectives and also privately amongst each other. Videotape dialogue excerpts capture how these young girls individually coped with the sexual abuse and responded to becoming child wives in a polygamous family. Criminal charges ultimately were not pursued because the key witness refused to testify against her biological father.

  4. Velo-facio-skeletal syndrome in a mother and daughter

    SciTech Connect

    Teebi, A.S.; Meyn, M.S.; Meyers-Seifer, C.H.

    1995-07-31

    We present a woman and her daughter with an apparently new short stature syndrome associated with facial and skeletal anomalies and hypernasality. Manifestations included hypertelorism with broad and high nasal bridge, epicanthal folds, narrow and high arched palate, mild mesomelic brachymelia, short broad hands, prominent finger pads, hyperextensibility of hand joints, small feet, nasal voice, and normal intelligence. The mother had short stubby thumbs and the daughter had posteriorly angulated ears and delayed bone age. The morphology of the nose and the hypernasality are reminiscent to those in the velo-cardio-facial syndrome. High resolution banding and fluorescent in situ hybridization studies showed no evidence of 22q11 deletions. Differentiation from Aarskog syndrome and Robinow syndrome is discussed. 9 refs., 5 figs., 3 tabs.

  5. Menarche and puberty in daughters of amenorrheic women.

    PubMed

    Ben-Rafael, Z; Blankstein, J; Sack, J; Lunenfeld, B; Oelsner, G; Serr, D M; Mashiach, S

    1983-12-16

    Twenty-six daughters born to amenorrheic women after gonadotropin-induced ovulation were studied at 10 to 16 years of age. The aim of the study was to assess whether the mothers' condition, namely, amenorrhea and infertility followed by the pharmacologic induction of ovulation, had any effect on their female offspring in terms of endocrine disorders at puberty. The daughters were found to have normal onset of puberty as well as normal physical and mental development. The mean age at menarche, body weight, and height were similar to those of the general female population in Israel. A functioning hypothalamic-pituitary-ovarian axis was evidenced by the appearance of menarche followed by regular cycles. These data form a reassuring sample for the clinicians, the treated mothers, and their offspring.

  6. Latina Mother–Daughter Dyads: Relations Between Attachment and Sexual Behavior Under the Influence of Alcohol or Drugs

    PubMed Central

    Dillon, Frank R.; Rojas, Patria; Schwartz, Seth J.; Duan, Rui

    2009-01-01

    Associations among mother-daughter attachment, mother and daughter substance abuse, and daughter’s sexual behavior under the influence of drugs and alcohol were investigated among 158 adult U.S. Latina daughters. Latina daughters were sampled from four mother–daughter dyad types: substance abusing mother and daughter, substance abusing mother only, substance abusing daughter only, and nonsubstance-abusing mother and daughter. Substance abusing daughters with substance abusing mothers, and daughters who were less strongly attached to their mothers, reported more sex under the influence of drugs. Age, marital status, substance abuse, and mother’s substance abuse all influenced the daughter’s sex under the influence of alcohol. An unexpected positive association between attachment and sex under the influence of alcohol was found for daughters who were more closely attached to a substance abusing mother. Implications for future research, and HIV/AIDS and drug prevention and treatment programs for Latinas are discussed. PMID:19399605

  7. A Critical Review of Alpha Radionuclide Therapy—How to Deal with Recoiling Daughters?

    PubMed Central

    de Kruijff, Robin M.; Wolterbeek, Hubert T.; Denkova, Antonia G.

    2015-01-01

    This review presents an overview of the successes and challenges currently faced in alpha radionuclide therapy. Alpha particles have an advantage in killing tumour cells as compared to beta or gamma radiation due to their short penetration depth and high linear energy transfer (LET). Touching briefly on the clinical successes of radionuclides emitting only one alpha particle, the main focus of this article lies on those alpha-emitting radionuclides with multiple alpha-emitting daughters in their decay chain. While having the advantage of longer half-lives, the recoiled daughters of radionuclides like 224Ra (radium), 223Ra, and 225Ac (actinium) can do significant damage to healthy tissue when not retained at the tumour site. Three different approaches to deal with this problem are discussed: encapsulation in a nano-carrier, fast uptake of the alpha emitting radionuclides in tumour cells, and local administration. Each approach has been shown to have its advantages and disadvantages, but when larger activities need to be used clinically, nano-carriers appear to be the most promising solution for reducing toxic effects, provided there is no accumulation in healthy tissue. PMID:26066613

  8. Unusual Father-to-Daughter Transmission of Incontinentia Pigmenti Due to Mosaicism in IP Males.

    PubMed

    Fusco, Francesca; Conte, Matilde Immacolata; Diociaiuti, Andrea; Bigoni, Stefania; Branda, Maria Francesca; Ferlini, Alessandra; El Hachem, Maya; Ursini, Matilde Valeria

    2017-09-01

    Incontinentia pigmenti (IP; Online Mendelian Inheritance in Man catalog #308300) is an X-linked dominant ectodermal disorder caused by mutations of the inhibitor of κ polypeptide gene enchancer in B cells, kinase γ (IKBKG)/ nuclear factor κB, essential modulator (NEMO) gene. Hemizygous IKBKG/NEMO loss-of-function (LoF) mutations are lethal in males, thus patients are female, and the disease is always transmitted from an IP-affected mother to her daughter. We present 2 families with father-to-daughter transmission of IP and provide for the first time molecular evidence that the combination of somatic and germ-line mosaicism for IKBKG/NEMO loss of function mutations in IP males resulted in the transmission of the disease to a female child. We searched for the IKBKG/NEMO mutant allele in blood, urine, skin, and sperm DNA and found that the 2 fathers were somatic and germ-line mosaics for the p.Gln132×mutation or the exon 4-10 deletion of IKBKG/NEMO, respectively. The highest level of IKBKG/NEMO mutant cells was detected in the sperm, which might explain the recurrence of the disease. We therefore recommend careful clinical evaluation in IP male cases and the genetic investigation in sperm DNA to ensure correct genetic counseling and prevent the risk of paternal transmission of IP. Copyright © 2017 by the American Academy of Pediatrics.

  9. Short-lived Rn-222 daughters in cryogenic liquids

    SciTech Connect

    Pelczar, Krzysztof; Frodyma, Nikodem; Wójcik, Marcin

    2013-08-08

    In this paper a detection method of α emitters from {sup 222}Rn decay chain, present in cryogenic liquids, using bare Si-PIN diodes immersed in the liquids is presented. Properties of ionized {sup 222}Rn daughters deduced from conducted measurements are outlined. Life-time of positive ions was found to be of the order of 10 s, and nonzero content of electronegative ions was observed.

  10. Dynamics of phragmoplastin in living cells during cell plate formation and uncoupling of cell elongation from the plane of cell division.

    PubMed Central

    Gu, X; Verma, D P

    1997-01-01

    The cell plate is formed by the fusion of Golgi apparatus-derived vesicles in the center of the phragmoplast during cytokinesis in plant cells. A dynamin-like protein, phragmoplastin, has been isolated and shown to be associated with cell plate formation in soybean by using immunocytochemistry. In this article, we demonstrate that similar to dynamin, phragmoplastin polymerizes to form oligomers. We fused soybean phragmoplastin with the green fluorescence protein (GFP) and introduced it into tobacco BY-2 cells to monitor the dynamics of early events in cell plate formation. We demonstrate that the chimeric protein is functional and targeted to the cell plate during cytokinesis in transgenic cells. GFP-phragmoplastin was found to appear first in the center of the forming cell plate, and as the cell plate grew outward, it redistributed to the growing margins of the cell plate. The redistribution of phragmoplastin may require microtubule reorganization because the microtubule-stabilizing drug taxol inhibited phragmoplastin redistribution. Our data show that throughout the entire process of cytokinesis, phragmoplastin is concentrated in the area in which membrane fusion is active, suggesting that phragmoplastin participates in an early membrane fusion event during cell plate formation. Based on the dynamics of GFP-phragmoplastin, it appears that the process of cell plate formation is completed in two phases. The first phase is confined to the cylinder of the phragmoplast proper and is followed by a second phase that deposits phragmoplast vesicles in a concentric fashion, resulting in a ring of fluorescence, with the concentration of vesicles being higher at the periphery. In addition, overexpression of GFP-phragmoplastin appears to act as a dominant negative, slowing down the completion of cell plate formation, and often results in an oblique cell plate. The latter appears to uncouple cell elongation from the plane of cell division, forming twisted and elongated cells

  11. Myotube formation is affected by adipogenic lineage cells in a cell-to-cell contact-independent manner

    SciTech Connect

    Takegahara, Yuki; Yamanouchi, Keitaro Nakamura, Katsuyuki; Nakano, Shin-ichi; Nishihara, Masugi

    2014-05-15

    Intramuscular adipose tissue (IMAT) formation is observed in some pathological conditions such as Duchenne muscular dystrophy (DMD) and sarcopenia. Several studies have suggested that IMAT formation is not only negatively correlated with skeletal muscle mass but also causes decreased muscle contraction in sarcopenia. In the present study, we examined w hether adipocytes affect myogenesis. For this purpose, skeletal muscle progenitor cells were transfected with siRNA of PPARγ (siPPARγ) in an attempt to inhibit adipogenesis. Myosin heavy chain (MHC)-positive myotube formation was promoted in cells transfected with siPPARγ compared to that of cells transfected with control siRNA. To determine whether direct cell-to-cell contact between adipocytes and myoblasts is a prerequisite for adipocytes to affect myogenesis, skeletal muscle progenitor cells were cocultured with pre- or mature adipocytes in a Transwell coculture system. MHC-positive myotube formation was inhibited when skeletal muscle progenitor cells were cocultured with mature adipocytes, but was promoted when they were cocultured with preadipocytes. Similar effects were observed when pre- or mature adipocyte-conditioned medium was used. These results indicate that preadipocytes play an important role in maintaining skeletal muscle mass by promoting myogenesis; once differentiated, the resulting mature adipocytes negatively affect myogenesis, leading to the muscle deterioration observed in skeletal muscle pathologies. - Highlights: • We examined the effects of pre- and mature adipocytes on myogenesis in vitro. • Preadipocytes and mature adipocytes affect myoblast fusion. • Preadipocytes play an important role in maintaining skeletal muscle mass. • Mature adipocytes lead to muscle deterioration observed in skeletal muscle pathologies.

  12. Prenatal effects of maternal smoking on daughters' smoking: nicotine or testosterone exposure?

    PubMed Central

    Kandel, D B; Udry, J R

    1999-01-01

    OBJECTIVES: The purpose of this study was to specify the effect of prenatal fetal exposure to maternal cotinine and testosterone on daughters' smoking in adolescence and adulthood. METHODS: Longitudinal causal models were estimated among 240 White mother-daughter pairs from the Child Health and Development Study. Mothers and daughters were reinterviewed when daughters were aged 15 to 17 years, and daughters were interviewed at 27 to 30 years of age. Blood samples were obtained from both parents during pregnancy and from adult daughters. RESULTS: Testosterone and smoking were positively correlated among mothers during their pregnancy and among adult daughters. Maternal prenatal cotinine had no direct effect on daughters' smoking; self-reported smoking in pregnancy did have a direct effect. Smoking among daughters during adolescence was determined by maternal prenatal testosterone and self-reported maternal smoking during pregnancy and postnatally. Smoking among adult daughters reflected chronic smoking since adolescence and the continuing effect of postnatal maternal smoking. Prenatal maternal testosterone affected adult daughters' testosterone. CONCLUSIONS: Estimates of the impact of prenatal maternal smoking depend on the measure of smoking. Prenatal testosterone exposure is a previously unrecognized risk factor for smoking among female offspring. PMID:10474556

  13. Macrophage conditioned medium induced cellular network formation in MCF-7 cells through enhanced tunneling nanotube formation and tunneling nanotube mediated release of viable cytoplasmic fragments.

    PubMed

    Patheja, Pooja; Sahu, Khageswar

    2017-04-12

    Infiltrating macrophages in tumor microenvironment, through their secreted cytokines and growth factors, regulate several processes of cancer progression such as cancer cell survival, proliferation, invasion, metastasis and angiogenesis. Recently, intercellular cytoplasmic bridges between cancer cells referred as tunneling nanotubes (TNTs) have been recognized as novel mode of intercellular communication between cancer cells. In this study, we investigated the effect of inflammatory mediators present in conditioned medium derived from macrophages on the formation of TNTs in breast adenocarcinoma cells MCF-7. Results show that treatment with macrophage conditioned medium (MɸCM) not only enhanced TNT formation between cells but also stimulated the release of independently migrating viable cytoplasmic fragments, referred to as microplasts, from MCF-7 cells. Time lapse microscopy revealed that microplasts were released from parent cancer cells in extracellular space through formation of TNT-like structures. Mitochondria, vesicles and cytoplasm could be transferred from parent cell body to microplasts through connecting TNTs. The microplasts could also be resorbed into the parent cell body by retraction of the connecting TNTs. Microplast formation inhibited in presence cell migration inhibitor, cytochalasin-B. Notably by utilizing migratory machinery within microplasts, distantly located MCF-7 cells formed several TNT based intercellular connections, leading to formation of physically connected network of cells. Together, these results demonstrate novel role of TNTs in microplast formation, novel modes of TNT formation mediated by microplasts and stimulatory effect of MɸCM on cellular network formation in MCF-7 cells mediated through enhanced TNT and microplast formation.

  14. Intention to Seek Mental Health Treatment for Adolescent Girls: Comparison of Predictors in Mothers and Daughters

    PubMed Central

    Logsdon, M. Cynthia; Pinto, Melissa D.; LaJoie, A. Scott; Hertweck, Paige; Lynch, Tania; Flamini, Laura

    2013-01-01

    PROBLEM To examine predictors of intention to seek mental health treatment for adolescent girls in mothers and daughters. METHODS In this cross-sectional study, mothers and adolescent daughters (n = 71) completed measures of behavioral attitudes, subjective norms, perceived behavioral control, and intention to seek mental health treatment for the adolescent daughter. FINDINGS Behavioral attitude and perceived behavioral control predicted intention to seek mental health treatment among mothers. Behavioral attitude predicted intention among daughters. There were no associations between mothers and daughters on study variables. CONCLUSIONS To promote shared decision making and engagement in mental health treatment, clinicians may target interventions to the mother’s perceived behavioral control and behavioral attitudes of daughters and mothers. Based upon study results, clinicians should promote shared decision making and concordance between mothers and daughters on attitudes toward mental health treatment. PMID:24180603

  15. Mitochondrial quality control during inheritance is associated with lifespan and mother-daughter age asymmetry in budding yeast.

    PubMed

    McFaline-Figueroa, José Ricardo; Vevea, Jason; Swayne, Theresa C; Zhou, Chun; Liu, Christopher; Leung, Galen; Boldogh, Istvan R; Pon, Liza A

    2011-10-01

    Fluorescence loss in photobleaching experiments and analysis of mitochondrial function using superoxide and redox potential biosensors revealed that mitochondria within individual yeast cells are physically and functionally distinct. Mitochondria that are retained in mother cells during yeast cell division have a significantly more oxidizing redox potential and higher superoxide levels compared to mitochondria in buds. Retention of mitochondria with more oxidizing redox potential in mother cells occurs to the same extent in young and older cells and can account for the age-associated decline in total cellular mitochondrial redox potential in yeast as they age from 0 to 5 generations. Deletion of Mmr1p, a member of the DSL1 family of tethering proteins that localizes to mitochondria at the bud tip and is required for normal mitochondrial inheritance, produces defects in mitochondrial quality control and heterogeneity in replicative lifespan (RLS). Long-lived mmr1Δ cells exhibit prolonged RLS, reduced mean generation times, more reducing mitochondrial redox potential and lower mitochondrial superoxide levels compared to wild-type cells. Short-lived mmr1Δ cells exhibit the opposite phenotypes. Moreover, short-lived cells give rise exclusively to short-lived cells, while the majority of daughters of long-lived cells are long lived. These findings support the model that the mitochondrial inheritance machinery promotes retention of lower-functioning mitochondria in mother cells and that this process contributes to both mother-daughter age asymmetry and age-associated declines in cellular fitness.

  16. Aurora B–mediated localized delays in nuclear envelope formation facilitate inclusion of late-segregating chromosome fragments

    PubMed Central

    Karg, Travis; Warecki, Brandt; Sullivan, William

    2015-01-01

    To determine how chromosome segregation is coordinated with nuclear envelope formation (NEF), we examined the dynamics of NEF in the presence of lagging acentric chromosomes in Drosophila neuroblasts. Acentric chromosomes often exhibit delayed but ultimately successful segregation and incorporation into daughter nuclei. However, it is unknown whether these late-segregating acentric fragments influence NEF to ensure their inclusion in daughter nuclei. Through live analysis, we show that acentric chromosomes induce highly localized delays in the reassembly of the nuclear envelope. These delays result in a gap in the nuclear envelope that facilitates the inclusion of lagging acentrics into telophase daughter nuclei. Localized delays of nuclear envelope reassembly require Aurora B kinase activity. In cells with reduced Aurora B activity, there is a decrease in the frequency of local nuclear envelope reassembly delays, resulting in an increase in the frequency of acentric-bearing, lamin-coated micronuclei. These studies reveal a novel role of Aurora B in maintaining genomic integrity by promoting the formation of a passageway in the nuclear envelope through which late-segregating acentric chromosomes enter the telophase daughter nucleus. PMID:25877868

  17. Neuronal connections, cell formation and cell migration in the perinatal human hippocampal dentate gyrus.

    PubMed

    Seress, L

    1998-06-01

    Jean Piaget's "stage theory" suggests that cognitive development proceeds in discrete steps, among which the first is the sensorimotor period that occupies the first two years. In recent years it became clear that an intact and mature hippocampus is necessary for memory formation both in experimental animals and in human. In the present experiments the perinatal morphological development of the human hippocampus was studied to describe structural changes that may correlate with the developmental changes of intellectual growth. Our results suggest that cell formation in the human hippocampus terminates several weeks before birth, but immature cells migrate to their final positions through the first six postnatal months. The newborn hippocampus contains all cell types and cell layers that are characteristic for the adult hippocampus. However, changes of the light microscopic features of the postsynaptic target neurons of hippocampal granule cells indicate that connections between granule cells and their target neurons are immature at birth and develop through an extended period of time that may last for three years. Since this neuronal connection is the first link in the chain of the main hippocampal synaptic circuitry, it may be suggested that human hippocampus is functionally impaired at birth. This period of light microscopic morphological maturation correlates well with the time period of Piaget's first stage of cognitive development. It can also be suggested that the prolonged postnatal development of some neuronal circuitries in the human hippocampus may be responsible for the psychological phenomenon of "infantile amnesia", that is the lack of memory traces from the early postnatal period.

  18. Establishment of cell polarity by afadin during the formation of embryoid bodies.

    PubMed

    Komura, Hitomi; Ogita, Hisakazu; Ikeda, Wataru; Mizoguchi, Akira; Miyoshi, Jun; Takai, Yoshimi

    2008-01-01

    Afadin directly links nectin, an immunoglobulin-like cell-cell adhesion molecule, to actin filaments (F-actin) at adherens junctions (AJs). The nectin-afadin complex is important for the formation of not only AJs but also tight junctions (TJs) in epithelial cells. Studies using afadin-knockout mice have revealed that afadin is indispensable for embryonic development by organizing the formation of cell-cell junctions. However, the molecular mechanism of cell-cell junction disorganization during embryonic development in afadin-knockout mice is poorly understood. To address this, we took advantage of embryoid bodies (EBs) as a model system. The formation of cell-cell junctions including AJs and TJs was impaired in afadin-null EBs. The proper accumulation of the Par complex and the activation of Cdc42 and atypical PKC (aPKC), which are crucial for the formation of cell polarity, were also inhibited by knockout of afadin. In addition, the disruption of afadin caused the abnormal deposition of laminin and the dislocalization of its receptors integrin alpha(6) and integrin beta(1). These results indicate that afadin organizes the formation of cell-cell junctions by regulating cell polarization in early embryonic development.

  19. Complement-dependent control of teratoma formation by embryonic stem cells.

    PubMed

    Koch, Cody A; Jordan, Corinne E; Platt, Jeffrey L

    2006-10-01

    The fetus has pluripotent stem cells that when transferred to mature individuals can generate tumors. However, for reasons yet unknown, tumors form rarely in the fetus and/or the mother during normal gestation. We questioned whether the complement system might protect against tumor formation by pluripotent stem cells. Murine embryonic stem cells were notably more susceptible than cardiomyocytes differentiated from those cells to lysis by complement in heterologous and homologous sera. Treatment of embryonic stem cells with heterologous serum averted tumor formation after residual cells were transplanted into mice. Confirming the importance of homologous complement in preventing formation of tumors, untreated embryonic stem cells formed tumors more quickly in C3-deficient than in wild-type mice. Susceptibility of embryonic stem cells to complement required an intact alternative pathway and was owed at least in part to a relative deficiency of sialic acid on cell surfaces compared with differentiated cells. Susceptibility to complement and resistance to tumors was inversely related to the number of cells transferred. These findings show that formation of tumors from embryonic stem cells is controlled in part by the alternative pathway of complement and suggest that susceptibility to complement might represent a general property of pluripotent stem cells that can be exploited to prevent tumor formation.

  20. Shear flow-induced formation of tubular cell protrusions in multiple myeloma cells

    PubMed Central

    Porat, Ziv; Yaron, Itamar; Katz, Ben-Zion; Kam, Zvi; Geiger, Benjamin

    2011-01-01

    Exposure of live cells to shear flow induces major changes in cell shape, adhesion to the extracellular matrix, and migration. In the present study, we show that exposure of cultured multiple myeloma (MM) cells to shear flow of 4–36 dynes/cm2 triggers the extension of long tubular protrusions (denoted FLow-Induced Protrusions, or FLIPs) in the direction of the flow. These FLIPs were found to be rich in actin, contain few or no microtubules and, apart from endoplasmic reticulum (ER)-like membranal structures, are devoid of organelles. Studying the dynamics of this process revealed that FLIPs elongate at their tips in a shear force-dependent manner, and retract at their bases. Examination of this force dependence revealed considerable heterogeneity in the mechanosensitivity of individual cells, most likely reflecting the diversity of the malignant B-cell population. The mechanisms underlying FLIP formation following mechanical perturbation, and their relevance to the cellular trafficking of MM cells, are discussed. PMID:21344380

  1. Multinuclear giant cell formation is enhanced by down-regulation of Wnt signaling in gastric cancer cell line, AGS

    SciTech Connect

    Kim, Shi-Mun; Kim, Rockki; Ryu, Jae-Hyun; Jho, Eek-Hoon; Song, Ki-Joon; Jang, Shyh-Ing; Kee, Sun-Ho . E-mail: keesh@korea.ac.kr

    2005-08-01

    AGS cells, which were derived from malignant gastric adenocarcinoma tissue, lack E-cadherin-mediated cell adhesion but have a high level of nuclear {beta}-catenin, which suggests altered Wnt signal. In addition, approximately 5% of AGS cells form multinuclear giant cells in the routine culture conditions, while taxol treatment causes most AGS cells to become giant cells. The observation of reduced nuclear {beta}-catenin levels in giant cells induced by taxol treatment prompted us to investigate the relationship between Wnt signaling and giant cell formation. After overnight serum starvation, the shape of AGS cells became flattened, and this morphological change was accompanied by decrease in Myc expression and an increase in the giant cell population. Lithium chloride treatment, which inhibits GSK3{beta} activity, reversed these serum starvation effects, which suggests an inverse relationship between Wnt signaling and giant cell formation. Furthermore, the down-regulation of Wnt signaling caused by the over-expression of ICAT, E-cadherin, and Axin enhanced giant cell formation. Therefore, down-regulation of Wnt signaling may be related to giant cell formation, which is considered to be a survival mechanism against induced cell death.

  2. KLF4-dependent perivascular cell plasticity mediates pre-metastatic niche formation and metastasis.

    PubMed

    Murgai, Meera; Ju, Wei; Eason, Matthew; Kline, Jessica; Beury, Daniel W; Kaczanowska, Sabina; Miettinen, Markku M; Kruhlak, Michael; Lei, Haiyan; Shern, Jack F; Cherepanova, Olga A; Owens, Gary K; Kaplan, Rosandra N

    2017-10-01

    A deeper understanding of the metastatic process is required for the development of new therapies that improve patient survival. Metastatic tumor cell growth and survival in distant organs is facilitated by the formation of a pre-metastatic niche that is composed of hematopoietic cells, stromal cells and extracellular matrix (ECM). Perivascular cells, including vascular smooth muscle cells (vSMCs) and pericytes, are involved in new vessel formation and in promoting stem cell maintenance and proliferation. Given the well-described plasticity of perivascular cells, we hypothesized that perivascular cells similarly regulate tumor cell fate at metastatic sites. We used perivascular-cell-specific and pericyte-specific lineage-tracing models to trace the fate of perivascular cells in the pre-metastatic and metastatic microenvironments. We show that perivascular cells lose the expression of traditional vSMC and pericyte markers in response to tumor-secreted factors and exhibit increased proliferation, migration and ECM synthesis. Increased expression of the pluripotency gene Klf4 in these phenotypically switched perivascular cells promoted a less differentiated state, characterized by enhanced ECM production, that established a pro-metastatic fibronectin-rich environment. Genetic inactivation of Klf4 in perivascular cells decreased formation of a pre-metastatic niche and metastasis. Our data revealed a previously unidentified role for perivascular cells in pre-metastatic niche formation and uncovered novel strategies for limiting metastasis.

  3. Live-Cell Analysis of Mitotic Spindle Formation in Taxol-Treated Cells

    PubMed Central

    Hornick, Jessica E.; Bader, Jason R.; Tribble, Emily K.; Trimble, Kayleigh; Breunig, J. Scott; Halpin, Elizabeth S.; Vaughan, Kevin T.; Hinchcliffe, Edward H.

    2009-01-01

    Taxol functions to suppress the dynamic behavior of individual microtubules, and induces multipolar mitotic spindles. However, little is known about the mechanisms by which taxol disrupts normal bipolar spindle assembly in vivo. Using live imaging of GFP-α tubulin expressing cells, we examined spindle assembly after taxol treatment. We find that as taxol-treated cells enter mitosis, there is a dramatic redistribution of the microtubule network from the centrosomes to the cell cortex. As they align there, the cortical microtubules recruit NuMA to their embedded ends, followed by the kinesin motor HSET. These cortical microtubules then bud off to form cytasters, which fuse into multipolar spindles. Cytoplasmic dynein and dynactin do not re-localize to cortical microtubules, and disruption of dynein/dynactin interactions by over-expression of p50 “dynamitin” does not prevent cytaster formation. Taxol added well before spindle poles begin to form induces multipolarity, but taxol added after nascent spindle poles are visible—but before NEB is complete—results in bipolar spindles. Our results suggest that taxol prevents rapid transport of key components, such as NuMA, to the nascent spindle poles. The net result is loss of mitotic spindle pole cohesion, microtubule re-distribution, and cytaster formation. PMID:18481305

  4. Tunneling nanotube formation is stimulated by hypoxia in ovarian cancer cells

    PubMed Central

    Vogel, Rachel I.; Thayanithy, Venugopal; Wong, Phillip; Teoh, Deanna; Geller, Melissa A.; Steer, Clifford J.; Subramanian, Subbaya; Lou, Emil

    2016-01-01

    In this study, we demonstrated that hypoxic conditions stimulated an increase in tunneling nanotube (TNT) formation in chemoresistant ovarian cancer cells (SKOV3, C200). We found that suppressing the mTOR pathway using either everolimus or metformin led to suppression of TNT formation in vitro, verifying TNTs as a potential target for cancer-directed therapy. Additionally, TNT formation was detected in co-cultures including between platinum-resistant SKOV3 cells, between SKOV3 cells and platinum-chemosensitive A2780 cells, and between SKOV3 cells cultured with benign ovarian epithelial (IOSE) cells; these findings indicate that TNTs are novel conduits for malignant cell interactions and tumor cell interactions with other cells in the microenvironment. When chemoresistant C200 and parent chemosensitive A2780 cells were co-cultured, chemoresistant cells displayed a higher likelihood of TNT formation to each other than to chemosensitive malignant or benign epithelial cells. Hypoxia-induced TNT formation represents a potential mechanism for intercellular communication in ovarian cancer and other forms of invasive refractory cancers. PMID:27223082

  5. Control of cell fate by the formation of an architecturally complex bacterial community

    PubMed Central

    Vlamakis, Hera; Aguilar, Claudio; Losick, Richard; Kolter, Roberto

    2008-01-01

    Bacteria form architecturally complex communities known as biofilms in which cells are held together by an extracellular matrix. Biofilms harbor multiple cell types, and it has been proposed that within biofilms individual cells follow different developmental pathways, resulting in heterogeneous populations. Here we demonstrate cellular differentiation within biofilms of the spore-forming bacterium Bacillus subtilis, and present evidence that formation of the biofilm governs differentiation. We show that motile, matrix-producing, and sporulating cells localize to distinct regions within the biofilm, and that the localization and percentage of each cell type is dynamic throughout development of the community. Importantly, mutants that do not produce extracellular matrix form unstructured biofilms that are deficient in sporulation. We propose that sporulation is a culminating feature of biofilm formation, and that spore formation is coupled to the formation of an architecturally complex community of cells. PMID:18381896

  6. A Comparison of the Perceptions of the Mother-Daughter Relationship of Black Pregnant and Nonpregnant Teenagers.

    ERIC Educational Resources Information Center

    Rogers, Earline; Lee, Sally Hughes

    1992-01-01

    Examined perceived relationships between pregnant and nonpregnant teenage girls and their mothers (n=52 mother-daughter dyads). Nonpregnant daughters and their mothers felt significantly more intimacy toward each other than did pregnant daughters and their mothers. Correlations of mother and daughter scores revealed that intimacy scores of mothers…

  7. 29 CFR 825.122 - Definitions of spouse, parent, son or daughter, next of kin of a covered servicemember, adoption...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of a covered servicemember, adoption, foster care, son or daughter on active duty or call to active..., adoption, foster care, son or daughter on active duty or call to active duty status, son or daughter of a... the employee when the employee was a son or daughter as defined in paragraph (c) of this section....

  8. BCL6 interacting corepressor contributes to germinal center T follicular helper cell formation and B cell helper function

    PubMed Central

    Yang, Jessica A.; Tubo, Noah J.; Gearhart, Micah D.; Bardwell, Vivian J.; Jenkins, Marc K.

    2015-01-01

    CD4+ germinal center (GC) T follicular helper (GC-Tfh) cells help B cells become long-lived plasma cells and memory cells. The transcriptional repressor BCL6 plays a key role in GC-Tfh formation by inhibiting the expression of genes that promote differentiation into other lineages. We determined whether BCOR, a component of a Polycomb repressive complex that interacts with the BCL6 BTB domain, influences GC-Tfh differentiation. T cell-targeted BCOR deficiency led to a substantial loss of peptide:MHCII-specific GC-Tfh cells following Listeria monocytogenes infection and a 2-fold decrease following immunization with a peptide in CFA. The reduction in GC-Tfh cells was associated with diminished plasma cell and GC B cell formation. Thus, T cell-expressed BCOR is critical for optimal GC-Tfh differentiation and humoral immunity. PMID:25964495

  9. The effects of substrate elasticity on endothelial cell network formation and traction force generation.

    PubMed

    Califano, Joseph P; Reinhart-King, Cynthia A

    2009-01-01

    While the growth factors and cytokines known to influence angiogenesis and vasculogenesis have garnered widespread attention, less is known about how the mechanical environment affects blood vessel formation and cell assembly. In this study, we investigate the relationship between substrate elasticity, endothelial cell-cell connectivity and traction force generation. We find that on more compliant substrates, endothelial cells self-assemble into network-like structures independently of additional exogenous growth factors or cytokines. These networks form from the assembly of sub-confluent endothelial cells on compliant (E = 200-1000Pa) substrates, and results from both the proliferation and migration of endothelial cells. Interestingly, stabilization of these cell-cell connections and networks requires fibronectin polymerization. Traction Force Microscopy measurements indicate that individual endothelial cells on compliant substrates exert forces which create substrate stains that propagate from the cell edge. We speculate that these strains draw the cells together and initiate self-assembly. Notably, endothelial cell network formation on compliant substrates is dynamic and transient; as cell number and substrate strains increase, the networks fill in through collective cell movements from the network edges. Our results indicate that network formation is mediated in part by substrate mechanics and that cellular traction force may promote cell-cell assembly by directing cell migration.

  10. Formate: an Energy Storage and Transport Bridge between Carbon Dioxide and a Formate Fuel Cell in a Single Device.

    PubMed

    Vo, Tracy; Purohit, Krutarth; Nguyen, Christopher; Biggs, Brenna; Mayoral, Salvador; Haan, John L

    2015-11-01

    We demonstrate the first device to our knowledge that uses a solar panel to power the electrochemical reduction of dissolved carbon dioxide (carbonate) into formate that is then used in the same device to operate a direct formate fuel cell (DFFC). The electrochemical reduction of carbonate is carried out on a Sn electrode in a reservoir that maintains a constant carbon balance between carbonate and formate. The electron-rich formate species is converted by the DFFC into electrical energy through electron release. The product of DFFC operation is the electron-deficient carbonate species that diffuses back to the reservoir bulk. It is possible to continuously charge the device using alternative energy (e.g., solar) to convert carbonate to formate for on-demand use in the DFFC; the intermittent nature of alternative energy makes this an attractive design. In this work, we demonstrate a proof-of-concept device that performs reduction of carbonate, storage of formate, and operation of a DFFC. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Lysophosphatidic acid directly induces macrophage-derived foam cell formation by blocking the expression of SRBI.

    PubMed

    Chen, Linmu; Zhang, Jun; Deng, Xiao; Liu, Yan; Yang, Xi; Wu, Qiong; Yu, Chao

    2017-09-23

    The leading cause of morbidity and mortality is the result of cardiovascular disease, mainly atherosclerosis. The formation of macrophage foam cells by ingesting ox-LDL and focal retention in the subendothelial space are the hallmarks of the early atherosclerotic lesion. Lysophosphatidic acid (LPA), which is a low-molecular weight lysophospholipid enriched in oxidized LDL, exerts a range of effects on the cardiovascular system. Previous reports show that LPA increases the uptake of ox-LDL to promote the formation of foam cells. However, as the most active component of ox-LDL, there is no report showing whether LPA directly affects foam cell formation. The aim of this study was to investigate the effects of LPA on foam cell formation, as well as to elucidate the underlying mechanism. Oil red O staining and a Cholesterol/cholesteryl ester quantitation assay were used to evaluate foam cell formation in Raw264.7 macrophage cells. We utilized a Western blot and RT-PCR to investigate the relationship between LPA receptors and lipid transport related proteins. We found that LPA promoted foam cell formation, using 200 μM for 24 h. Meanwhile, the expression of the Scavenger receptor BI (SRBI), which promotes the efflux of free cholesterol, was decreased. Furthermore, the LPA1/3 receptor antagonist Ki16425 significantly abolished the LPA effects, indicating that LPA1/3 was involved in the foam cell formation and SRBI expression induced by LPA. Additionally, the LPA-induced foam cell formation was blocked with an AKT inhibitor. Our results suggest that LPA-enhanced foam cell formation is mediated by LPA1/3 -AKT activation and subsequent SRBI expression. Copyright © 2017. Published by Elsevier Inc.

  12. Cell-size distribution in epithelial tissue formation and homeostasis.

    PubMed

    Puliafito, Alberto; Primo, Luca; Celani, Antonio

    2017-03-01

    How cell growth and proliferation are orchestrated in living tissues to achieve a given biological function is a central problem in biology. During development, tissue regeneration and homeostasis, cell proliferation must be coordinated by spatial cues in order for cells to attain the correct size and shape. Biological tissues also feature a notable homogeneity of cell size, which, in specific cases, represents a physiological need. Here, we study the temporal evolution of the cell-size distribution by applying the theory of kinetic fragmentation to tissue development and homeostasis. Our theory predicts self-similar probability density function (PDF) of cell size and explains how division times and redistribution ensure cell size homogeneity across the tissue. Theoretical predictions and numerical simulations of confluent non-homeostatic tissue cultures show that cell size distribution is self-similar. Our experimental data confirm predictions and reveal that, as assumed in the theory, cell division times scale like a power-law of the cell size. We find that in homeostatic conditions there is a stationary distribution with lognormal tails, consistently with our experimental data. Our theoretical predictions and numerical simulations show that the shape of the PDF depends on how the space inherited by apoptotic cells is redistributed and that apoptotic cell rates might also depend on size. © 2017 The Author(s).

  13. Aggregate formation affects ultrasonic disruption of microalgal cells.

    PubMed

    Wang, Wei; Lee, Duu-Jong; Lai, Juin-Yih

    2015-12-01

    Ultrasonication is a cell disruption process of low energy efficiency. This study dosed K(+), Ca(2+) and Al(3+) to Chlorella vulgaris cultured in Bold's Basal Medium at 25°C and measured the degree of cell disruption under ultrasonication. Adding these metal ions yielded less negatively charged surfaces of cells, while with the latter two ions large and compact cell aggregates were formed. The degree of cell disruption followed: control=K(+)>Ca(2+)>Al(3+) samples. Surface charges of cells and microbubbles have minimal effects on the microbubble number in the proximity of the microalgal cells. Conversely, cell aggregates with large size and compact interior resist cell disruption under ultrasonication. Staining tests revealed high diffusional resistance of stains over the aggregate interior. Microbubbles may not be effective generated and collapsed inside the compact aggregates, hence leading to low cell disruption efficiencies. Effective coagulation/flocculation in cell harvesting may lead to adverse effect on subsequent cell disruption efficiency. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Generation to generation: discrimination and harassment experiences of physician mothers and their physician daughters.

    PubMed

    Shrier, Diane K; Zucker, Alyssa N; Mercurio, Andrea E; Landry, Laura J; Rich, Michael; Shrier, Lydia A

    2007-01-01

    To examine bias and sexual harassment experiences of physician mothers and their physician daughters; correlations of these experiences with career satisfaction, stress at work, stress at home, and percentage of women in specialty; and influences of the mother on her daughter's experiences. A convenience sample of 214 families with mother and daughter physicians was sent a 56-item survey that included questions on bias and sexual harassment experiences. Statistical comparisons were made within 136 dyads where both mother and daughter returned the questionnaire. Eighty-four percent of mothers and 87% of daughters responded. Mothers and daughters reported similarly high rates and severity of sexual harassment before medical school, while in residency/fellowship, while in practice/work setting, and by teachers and supervisors. Daughters reported higher rates of harassment during medical school and by patients, mothers by colleagues. Gender and racial/ethnic discrimination was lower for daughters compared with their mothers, but gender discrimination was still substantial. Compared with other daughters, daughters who experienced discrimination or sexual harassment reported lower career satisfaction and more stress at work and at home and worked in specialties with fewer women. Gender discrimination and sexual harassment remain entrenched in medical education and professional workplaces. Maternal role models and mentors were not as protective as anticipated. Leadership of medical institutions and professional associations must deal more effectively with persistent discrimination and harassment or risk the loss of future leaders.

  15. Maternal weight status modulates the effects of restriction on daughters' eating and weight

    PubMed Central

    Francis, LA; Birch, LL

    2008-01-01

    OBJECTIVE To examine the effects of overweight and normal-weight mothers' restriction in child feeding on daughters' eating in the absence of hunger (EAH) and body mass index (BMI) change from age 5 to age 9 y. DESIGN Longitudinal study of the health and development of young girls. SUBJECTS A total of 91 overweight and 80 normal-weight mothers and their daughters, assessed when daughters were ages 5, 7, and 9 y. MEASUREMENTS Measures included maternal restriction of daughters' intake at age 5 y, and daughters' EAH and BMI change from age 5 to 9 y. RESULTS There were no overall differences in the level of restriction that overweight and normal-weight mothers used. However, overweight mothers' restrictive feeding practices when daughters were age 5 y predicted daughters' EAH over time, and higher EAH scores were associated with greater BMI change from age 5 to 9 y. These relationships did not hold for daughters of normal-weight mothers. CONCLUSION More adverse effects of restriction on daughters' EAH, and links between EAH and BMI change were only noted among daughters of overweight mothers. These findings highlight the need for a better understanding of factors that contribute to within-group variation in eating behavior and weight status. PMID:15782227

  16. Attacks on linking: stressors and identity challenges for mothers of daughters with long lasting anorexia nervosa.

    PubMed

    Tuval-Mashiach, Rivka; Hasson-Ohayon, Ilanit; Ilan, Adi

    2014-01-01

    The purpose of the current study was to focus on the subjective experience of mothers of daughters with ongoing anorexia nervosa. Specifically, we explored the stressors faced by these mothers while coping with their daughters' illnesses; we also looked at how they experienced their maternal selves and roles, and their perceived competence in coping with their daughters' illnesses. Two related aspects were found to be central in the participants' experiences. One aspect was their network of relationships and how these relationships were challenged or compromised as a result of their daughters' illnesses. This aspect included the mothers' relationships with their daughters, the mothers' relationships with other family members and with their spouses/partners, the mothers' relationships with the professionals treating their daughters, and the mothers' relationships with themselves. The second related aspect was the challenge presented to the participants' self-perception as 'good mothers' by their daughters' illnesses. The findings showed that coping with a daughter's eating disorder (ED) posed a significant obstacle to the mother's ability to maintain a satisfying relationship with her daughter and her environment, as well as to maintain a positive maternal self-perception. The implications of these findings for professionals working with caregivers are discussed, and a more nuanced, gender-specific attitude is suggested in working with mothers caring for daughters with EDs.

  17. Boundary Vector Cells in the subiculum of the hippocampal formation

    PubMed Central

    Lever, Colin; Burton, Stephen; Jeewajee, Ali; O’Keefe, John; Burgess, Neil

    2009-01-01

    ‘Boundary Vector Cells’ were predicted to exist by computational models of the environmental inputs underlying the spatial firing patterns of hippocampal place cells (O’Keefe and Burgess, 1996; Burgess et al., 2000; Hartley et al., 2000). Here we report the existence of cells fulfilling this description in recordings from the subiculum of freely moving rats. These cells may contribute environmental information to place cell firing, complementing path integrative information. Their relationship to other cell types, including medial entorhinal ‘border cells’, is discussed. PMID:19657030

  18. Effects of irradiated biodegradable polymer in endothelial cell monolayer formation

    NASA Astrophysics Data System (ADS)

    Arbeitman, Claudia R.; del Grosso, Mariela F.; Behar, Moni; García Bermúdez, Gerardo

    2013-11-01

    In this work we study cell adhesion, proliferation and cell morphology of endothelial cell cultured on poly-L-lactide acid (PLLA) modified by heavy ion irradiation. Thin films of PLLA samples were irradiated with sulfur (S) at energies of 75 MeV and gold (Au) at 18 MeV ion-beams. Ion beams were provided by the Tandar (Buenos Aires, Argentina) and Tandetron (Porto Alegre, Brazil) accelerators, respectively. The growth of a monolayer of bovine aortic endothelial cells (BAEC) onto unirradiated and irradiated surfaces has been studied by in vitro techniques in static culture. Cell viability and proliferation increased on modified substrates. But the results on unirradiated samples, indicate cell death (necrosis/apoptosis) with the consequent decrease in proliferation. We analyzed the correlation between irradiation parameters and cell metabolism and morphology.

  19. Notch signaling acts before cell division to promote asymmetric cleavage and cell fate of neural precursor cells.

    PubMed

    Bhat, Krishna Moorthi

    2014-10-21

    Asymmetric cell divisions in the central nervous system generate neurons of diverse fates. In Drosophila melanogaster, the protein Numb localizes asymmetrically to dividing neural precursor cells such that only one daughter cell inherits Numb. Numb inhibits Notch signaling in this daughter cell, resulting in a different cell fate from the Notch-induced fate in the other-Numb-negative-daughter cell. Precursor cells undergo asymmetric cytokinesis generating daughter cells of different sizes. I found that inactivation of Notch in fly embryonic neural precursor cells disrupted the asymmetric positioning of the cleavage furrow and produced daughter cells of the same size and fate. Moreover, inactivation of Notch at different times altered the degree of asymmetric Numb localization, such that earlier inactivation of Notch caused symmetric distribution of Numb and later inactivation produced incomplete asymmetric localization of Numb. The extent of asymmetrically localized Numb positively correlated with the degree of asymmetric cytokinesis and the size disparity in daughter cells. Loss of Numb or expression of constitutively active Notch led to premature specification of the precursor cells into the fate of one of the daughter cells. Thus, in addition to its role in the specification of daughter cell fate after division, Notch controls Numb localization in the precursor cells to determine the size and fate of daughter cells. Numb also inhibits Notch signaling in precursor cells to prevent Notch-induced differentiation of the precursor cell, forming an autoregulatory loop.

  20. Embryoid body formation from embryonic and induced pluripotent stem cells: Benefits of bioreactors.

    PubMed

    Rungarunlert, Sasitorn; Techakumphu, Mongkol; Pirity, Melinda K; Dinnyes, Andras

    2009-12-31

    Embryonic stem (ES) cells have the ability to differentiate into all germ layers, holding great promise not only for a model of early embryonic development but also for a robust cell source for cell-replacement therapies and for drug screening. Embryoid body (EB) formation from ES cells is a common method for producing different cell lineages for further applications. However, conventional techniques such as hanging drop or static suspension culture are either inherently incapable of large scale production or exhibit limited control over cell aggregation during EB formation and subsequent EB aggregation. For standardized mass EB production, a well defined scale-up platform is necessary. Recently, novel scenario methods of EB formation in hydrodynamic conditions created by bioreactor culture systems using stirred suspension systems (spinner flasks), rotating cell culture system and rotary orbital culture have allowed large-scale EB formation. Their use allows for continuous monitoring and control of the physical and chemical environment which is difficult to achieve by traditional methods. This review summarizes the current state of production of EBs derived from pluripotent cells in various culture systems. Furthermore, an overview of high quality EB formation strategies coupled with systems for in vitro differentiation into various cell types to be applied in cell replacement therapy is provided in this review. Recently, new insights in induced pluripotent stem (iPS) cell technology showed that differentiation and lineage commitment are not irreversible processes and this has opened new avenues in stem cell research. These cells are equivalent to ES cells in terms of both self-renewal and differentiation capacity. Hence, culture systems for expansion and differentiation of iPS cells can also apply methodologies developed with ES cells, although direct evidence of their use for iPS cells is still limited.

  1. Antibody formation by bone marrow cells in irradiated mice

    PubMed Central

    Playfair, J. H. L.; Purves, Elizabeth C.

    1971-01-01

    Bone marrow-thymus cooperation experiments were carried out in lethally irradiated mice with sheep red blood cells (SRBC) as the antigen and direct plaque-forming cells (PFC) as the end point. Various parameters were altered, with the following results: (1) Above 800 rad, the response by marrow cells alone, as well as the increase due to added thymus cells, was independent of irradiation dose. (2) The response of marrow cells was greatest at high SRBC concentrations, but the co-operative effect of thymus cells was most evident at lower SRBC levels, and completely absent at high levels. (3) Increasing the number of marrow cells, without thymus, gave increasing numbers of PFC, but the dose-response curve did not suggest cell synergism. (4) Thymectomy and antithymocyte serum treatment of host or donor did not prevent the response by marrow cells alone. It was concluded that this was a true IgM response by antibody-forming precursors from the marrow, unaided by thymus-derived cells. PMID:4934135

  2. Stem cells catalyze cartilage formation by neonatal articular chondrocytes in 3D biomimetic hydrogels

    NASA Astrophysics Data System (ADS)

    Lai, Janice H.; Kajiyama, Glen; Smith, Robert Lane; Maloney, William; Yang, Fan

    2013-12-01

    Cartilage loss is a leading cause of disability among adults and effective therapy remains elusive. Neonatal chondrocytes (NChons) are an attractive allogeneic cell source for cartilage repair, but their clinical translation has been hindered by scarce donor availability. Here we examine the potential for catalyzing cartilage tissue formation using a minimal number of NChons by co-culturing them with adipose-derived stem cells (ADSCs) in 3D hydrogels. Using three different co-culture models, we demonstrated that the effects of co-culture on cartilage tissue formation are dependent on the intercellular distance and cell distribution in 3D. Unexpectedly, increasing ADSC ratio in mixed co-culture led to increased synergy between NChons and ADSCs, and resulted in the formation of large neocartilage nodules. This work raises the potential of utilizing stem cells to catalyze tissue formation by neonatal chondrocytes via paracrine signaling, and highlights the importance of controlling cell distribution in 3D matrices to achieve optimal synergy.

  3. A spindle-independent cleavage pathway controls germ cell formation in Drosophila

    PubMed Central

    Cinalli, Ryan M.; Lehmann, Ruth

    2013-01-01

    The primordial germ cells (PGCs) are the first cells to form during Drosophila melanogaster embryogenesis. While the process of somatic cell formation has been studied in detail, the mechanics of PGC formation are poorly understood. Here, using 4D multi-photon imaging combined with genetic and pharmacological manipulations, we find that PGC formation requires an anaphase spindle-independent cleavage pathway. In addition to utilizing core regulators of cleavage, including the small GTPase RhoA (Drosophila Rho) and the Rho associated kinase, ROCK (Drosophila Rok), we show that this pathway requires Germ cell-less (Gcl), a conserved BTB-domain protein not previously implicated in cleavage mechanics. This alternate form of cell formation suggests that organisms have evolved multiple molecular strategies for regulating the cytoskeleton during cleavage. PMID:23728423

  4. On the formation of germ cells: The good, the bad and the ugly.

    PubMed

    Chuva de Sousa Lopes, Susana M; Roelen, Bernard A J

    2010-03-01

    Mammalian germ cells are powerful cells, the only ones that transmit information to the next generation ensuring the continuation of the species. But "with great power, comes great responsibility", meaning that germ cells are only a few steps away from turning carcinogenic. Despite recent advances little is known about germ cell formation in mammals, predominantly because of the inaccessibility of these cells. Moreover, it is difficult to pin down what in essence is characteristic of a germ cell, as germ cells keep changing place, morphology, expression markers and epigenetic identity. Formation of (primordial) germ cells in primate ES cell cultures would therefore be helpful to identify molecular signalling pathways associated with germ cell differentiation and to study epigenetic changes in germ cells. In addition, the in vitro derivation of functional germ cells from ES cells could be used in combination with therapeutic cloning to generate patient-specific ES cell lines, and can have applications in animal breeding. In this review we present the state-of-the-art on how mouse and human germ cells are formed in vivo (the good), we discuss the link between germ cells, pluripotency and germ cell tumours (the bad) and show that despite continuous progress in trying to differentiate germ cells in vitro (the ugly) the generation of functional germ cells is still a real challenge.

  5. miR-17 inhibition enhances the formation of kidney cancer spheres with stem cell/ tumor initiating cell properties.

    PubMed

    Lichner, Zsuzsanna; Saleh, Carol; Subramaniam, Venkateswaran; Seivwright, Annetta; Prud'homme, Gerald Joseph; Yousef, George Makram

    2015-03-20

    Renal cell carcinoma (RCC) is an aggressive disease, with 35% chance of metastasis. The 'cancer stem cell' hypothesis suggests that a subset of cancer cells possess stem cell properties and is crucial in tumor initiation, metastasis and treatment resistance. We isolated RCC spheres and showed that they exhibit cancer stem cell/ tumor initiating cell-like properties including the formation of self-renewing spheres, high tumorigenicity and the ability to differentiate to cell types of the original tumor. Spheres showed increased expression of stem cell-related transcription factors and mesenchymal markers. miRNAs were differentially expressed between RCC spheres and their parental cells. Inhibition of miR-17 accelerated the formation of RCC spheres which shared molecular characteristics with the spontaneous RCC spheres. Target prediction pointed out TGFβ pathway activation as a possible mechanism to drive RCC sphere formation. We demonstrate that miR-17 overexpression interferes with the TGFβ-EMT axis and hinders RCC sphere formation; and validated TGFBR2 as a direct and biologically relevant target during this process. Thus, a single miRNA may have an impact on the formation of highly tumorigenic cancer spheres of kidney cancer.

  6. Commentary on Becoming a Daughter: Trauma is a powerful teacher.

    PubMed

    Veach, Patricia McCarthy

    2006-06-01

    Personal life crises profoundly impact genetic counselor practice. In this commentary, themes from Matloff's (in press) article, Becoming a Daughter are highlighted and expanded upon. These themes include: personal impact of a life crisis, and professional impact vis a vis empathy countertransference, self-disclosure, nondirectiveness, and self-confidence. Strategies that help genetic counselors manage personal life crises within their clinical practice and also promote their professional development are emphasized, including normalization of life crises, self-reflection, boundary-setting, and use of peer supervision and consultation.

  7. Paroxysmal kinesigenic dyskinesia in a mother and daughter.

    PubMed

    Khan, Waqas Ullah; Staios, G; Rana, Abdul Qayyum

    2010-06-01

    We report a rare case of familial paroxysmal kinesigenic dyskinesia. A 42-year-old woman and her 13-year-old daughter both presented with episodic curling of their hand and arm. These events were triggered by sudden movements and would last several seconds. Both patients' symptoms were unilateral and their physical and neurological examinations were normal. Treatment with carbamazepine improved their symptoms. Although an uncommon movement disorder it is important to recognize the clinical presentation of paroxysmal kinesigenic dyskinesia as most patients respond very well to medical treatment.

  8. Volcanic output of long-lived radon daughters

    NASA Astrophysics Data System (ADS)

    Lambert, G.; Ardouin, B.; Polian, G.

    1982-12-01

    The long-lived radon daughter concentrations of 11 volcano exhausts have been measured, with attention to the Po-210 activities. These activities are found to be 100,000 to 1,000,000 times greater than in a typical atmosphere. A total volcanic Po-210 output of 50,000 Ci/year can be estimated by balancing the total deposition, atmospheric production, and extra sources of this nuclide. In view of these results, it appears plausible to normalize the volcanic production of volatile elements to this Po-210 output.

  9. Effect of deformations and orientations in 100Sn daughter radioactivity

    NASA Astrophysics Data System (ADS)

    Sawhney, Gudveen; Sharma, Kanishka; Sharma, Manoj K.; Gupta, Raj K.

    2016-05-01

    Based on the preformed cluster model (PCM), we have extended our earlier study to investigate the effects of nuclear deformations and orientations of nuclei in context of ground-state de-excitation of Xe to Gd parents, resulting in a doubly closed shell 100Sn daughter and the complementary clusters. The comparison is also made with spherical choice of fragments to extract exclusive picture of the dynamics involved. Since PCM is based on collective clusterization picture, the preformation and penetration probabilities are shown to get modified considerably by inclusion of the quadrupole deformations (β2i) alone, which in turn affects the decay half-lives of the clusters.

  10. Sodium formate induces autophagy and apoptosis via the JNK signaling pathway of photoreceptor cells.

    PubMed

    Wang, Ying; Xu, Shao-Lin; Xu, Wen-Jing; Yang, Hai-Yan; Hu, Ping; Li, Yu-Xin

    2016-02-01

    Incidents associated with methanol intoxication resulting from the consumption of fake wine occur not infrequently worldwide. Certain individuals are made blind due to methanol poisoning. The present study aimed to investigate the effects of sodium formate exposure on photoreceptor cells (661W cells). The 661W cells were exposed to sodium formate for 6‑24 h and cell viability was determined using a 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyl‑2H‑tetrazolium bromide (MTT) assay. Subsequently, the 661W cells were exposed to 15 or 30 mM sodium formate for 24 h. The level of apoptosis was determined using Hoechst 33342/propidium iodide staining, visualizing the cells under a fluorescence microscope, and annexin V‑fluorescein isothiocyanate staining, using flow cytometric analysis. Intracellular reactive oxygen species (ROS) were measured using 2',7'‑dichlorofluorescein diacetate (DCFH‑DA) staining, followed by flow cytometric analysis. Autophagy of the 661W cells was measured by monodansylcadaverine staining. The activation of phosphorylated c‑Jun N‑terminal kinase (p‑JNK), B‑cell lymphoma (Bcl‑2), Bcl‑2‑associated X protein, cleaved caspase‑3, cleaved caspase‑9 and microtubule‑associated protein 1A/1B‑light chain 3 (LC3) was assessed by western blotting. The effects of Z‑VAD‑fmk (a pan‑caspase inhibitor) and SP600125 (a JNK inhibitor) on the viability of the sodium formate‑induced 661W cells were determined using an MTT assay. Sodium formate treatment induced a decrease in the viability of the 661W cells in a time‑ and a dose‑dependent manner. In addition, sodium formate at concentrations of 15 or 30 mM markedly increased the level of apoptosis and the ROS levels, as measured by DCFH‑DA staining of the 661W cells. Additionally, 661W cells exposed to sodium formate for 24 h exhibited increased levels of p‑JNK, Bax, cleaved caspase‑3, cleaved caspase‑9 and LC3II (the phosphatidylethanolamine‑modified form

  11. Transient cell–cell interactions in neural circuit formation

    PubMed Central

    Chao, Daniel L.; Ma, Le; Shen, Kang

    2011-01-01

    The wiring of the nervous system requires a complex orchestration of developmental events. Emerging evidence suggests that transient cell–cell interactions often serve as positional cues for axon guidance and synaptogenesis during the assembly of neural circuits. In contrast to the relatively stable cellular interactions between synaptic partners in mature circuits, these transient interactions involve cells that are not destined to be pre- or postsynaptic cells. Here we review the roles of these transient cell–cell interactions in a variety of developmental contexts and describe the mechanisms through which they organize neural connections. PMID:19300445

  12. Programmed cell death for defense against anomaly and tumor formation

    SciTech Connect

    Kondo, Sohei; Norimura, Toshiyuki; Nomura, Taisei

    1995-12-31

    Cell death after exposure to low-level radiation is often considered evidence that radiation is poisonous, however small the dose. Evidence has been accumulating to support the notion that cell death after low-level exposure to radiation results from activation of suicidal genes {open_quote}programmed cell death{close_quote} or {open_quote}apoptosis{close_quote} - for the health of the whole body. This paper gives experimental evidence that embryos of fruit flies and mouse fetuses have potent defense mechanisms against teratogenic or tumorigenic injury caused by radiation and carcinogens, which function through programmed cell death.

  13. The muscle satellite cell at 50: the formative years

    PubMed Central

    2011-01-01

    In February 1961, Alexander Mauro described a cell 'wedged' between the plasma membrane of the muscle fibre and the surrounding basement membrane. He postulated that it could be a dormant myoblast, poised to repair muscle when needed. In the same month, Bernard Katz also reported a cell in a similar location on muscle spindles, suggesting that it was associated with development and growth of intrafusal muscle fibres. Both Mauro and Katz used the term 'satellite cell' in relation to their discoveries. Today, the muscle satellite cell is widely accepted as the resident stem cell of skeletal muscle, supplying myoblasts for growth, homeostasis and repair. Since 2011 marks both the 50th anniversary of the discovery of the satellite cell, and the launch of Skeletal Muscle, it seems an opportune moment to summarise the seminal events in the history of research into muscle regeneration. We start with the 19th-century pioneers who showed that muscle had a regenerative capacity, through to the descriptions from the mid-20th century of the underlying cellular mechanisms. The journey of the satellite cell from electron microscope curio, to its gradual acceptance as a bona fide myoblast precursor, is then charted: work that provided the foundations for our understanding of the role of the satellite cell. Finally, the rapid progress in the age of molecular biology is briefly discussed, and some ongoing debates on satellite cell function highlighted. PMID:21849021

  14. Nicotinate-Curcumin Impedes Foam Cell Formation from THP-1 Cells through Restoring Autophagy Flux

    PubMed Central

    Gu, Hong-Feng; Li, Hai-Zhe; Tang, Ya-Ling; Tang, Xiao-Qing; Zheng, Xi-Long; Liao, Duan-Fang

    2016-01-01

    Our previous studies have indicated that a novel curcumin derivate nicotinate-curcumin (NC) has beneficial effects on the prevention of atherosclerosis, but the precise mechanisms are not fully understood. Given that autophagy regulates lipid metabolism, the present study was designed to investigate whether NC decreases foam cell formation through restoring autophagy flux in oxidized low-density lipoprotein (ox-LDL)-treated THP-1 cells. Our results showed that ox-LDL (100 μg/ml) was accumulated in THP-1 cells and impaired autophagy flux. Ox-LDL-induced impairment of autophagy was enhanced by treatment with the autophagy inhibitor chloroquine (CQ) and rescued by the autophagy inducer rapamycin. The aggregation of ox-LDL was increased by CQ, but decreased by rapamycin. In addition, colocalization of lipid droplets with LC3-II was remarkably reduced in ox-LDL group. In contrast, NC (10 μM) rescued the impaired autophagy flux by significantly increasing level of LC3-II, the number of autophagolysosomes, and the degradation of p62 in ox-LDL-treated THP-1 cells. Inhibition of the PI3K-Akt-mTOR signaling was required for NC-rescued autophagy flux. Notably, our results showed that NC remarkably promoted the colocalization of lipid droplets with autophagolysosomes, increased efflux of cholesterol, and reduced ox-LDL accumulation in THP-1 cells. However, treatment with 3-methyladenine (3-MA) or CQ reduced the protective effects of NC on lipid accumulation. Collectively, the findings suggest that NC decreases lipid accumulation in THP-1 cells through restoring autophagy flux, and further implicate that NC may be a potential therapeutic reagent to reverse atherosclerosis. PMID:27128486

  15. Mesenchymal stem cells injection in degenerated intervertebral disc: cell leakage may induce osteophyte formation.

    PubMed

    Vadalà, Gianluca; Sowa, Gwendolyn; Hubert, Mark; Gilbertson, Lars G; Denaro, Vincenzo; Kang, James D

    2012-05-01

    Recent studies have shown that mesenchymal stem cell (MSC)-based therapy might be an effective approach for the treatment of intervertebral disc degeneration (IDD). However, many unanswered questions remain before clinical translation, such as the most effective stem cell type, a reliable transplantation method, including the carrier choice, and the fate of stem cells after misdirected delivery, among others. The objective of the study was to evaluate the fate and effect of allogenic bone marrow MSCs after transplantation into an IDD model. The L2-3, L3-4 and L4-5 intervertebral discs (IVDs) of four rabbits were stabbed to create IDD. Rabbit MSCs were expanded in vitro and in part transduced with retrovirus/eGFP. After 3 weeks, 1 × 10(5) MSCs were injected into the IVDs. The rabbits were followed by X-ray and MRI 3 and 9 weeks after injection. Then the animals were sacrificed and the spines analysed histologically. MRI showed no signs of regeneration. X-ray and gross anatomy inspection demonstrated large anterolateral osteophytes. Histological analysis showed that the osteophytes were composed of mineralized tissue surrounded by chondrocytes, with the labelled MSCs among the osteophyte-forming cells. The labelled MSCs were not found in the nucleus. Inflammatory cells were not observed in any injected IVDs. These results raise concern that MSCs can migrate out of the nucleus and undesirable bone formation may occur. While cause cannot be inferred from this study, the presence of MSCs in the osteophytes suggests a potential side-effect with this approach. IVD regeneration strategies need to focus on cell carrier systems and annulus-sealing technologies to avoid pitfalls.

  16. Distinct tissue formation by heterogeneous printing of osteo- and endothelial progenitor cells.

    PubMed

    Fedorovich, Natalja E; Wijnberg, Hans M; Dhert, Wouter J A; Alblas, Jacqueline

    2011-08-01

    The organ- or tissue-printing approach, based on layered deposition of cell-laden hydrogels, is a new technique in regenerative medicine suitable to investigate whether mimicking the anatomical organization of cells, matrix, and bioactive molecules is necessary for obtaining or improving functional engineered tissues. Currently, data on performance of multicellular printed constructs in vivo are limited. In this study we illustrate the ability of the system to print intricate porous constructs containing two different cell types--endothelial progenitors and multipotent stromal cells--and show that these grafts retain heterogeneous cell organization after subcutaneous implantation in immunodeficient mice. We demonstrate that cell differentiation leading to the expected tissue formation occurs at the site of the deposited progenitor cell type. While perfused blood vessels are formed in the endothelial progenitor cell-laden part of the constructs, bone formation is taking place in the multipotent stromal cell-laden part of the printed grafts.

  17. Human NK cell development requires CD56-mediated motility and formation of the developmental synapse

    PubMed Central

    Mace, Emily M.; Gunesch, Justin T.; Dixon, Amera; Orange, Jordan S.

    2016-01-01

    While distinct stages of natural killer (NK) cell development have been defined, the molecular interactions that shape human NK cell maturation are poorly understood. Here we define intercellular interactions between developing NK cells and stromal cells which, through contact-dependent mechanisms, promote the generation of mature, functional human NK cells from CD34+ precursors. We show that developing NK cells undergo unique, developmental stage-specific sustained and transient interactions with developmentally supportive stromal cells, and that the relative motility of NK cells increases as they move through development in vitro and ex vivo. These interactions include the formation of a synapse between developing NK cells and stromal cells, which we term the developmental synapse. Finally, we identify a role for CD56 in developmental synapse structure, NK cell motility and NK cell development. Thus, we define the developmental synapse leading to human NK cell functional maturation. PMID:27435370

  18. Latino Mother/Daughter Dyadic Attachment as a Mediator for Substance Use Disorder and Emotional Abuse

    PubMed Central

    Kanamori, Mariano; Weissman, Jessica; De La Rosa, Mario; Trepka, Mary Jo; Rojas, Patria; Cano, Miguel Angel; Melton, James; Unterberger, Alayne

    2015-01-01

    Background To date, no studies have investigated emotional abuse of adult Latina women by their mothers despite evidence that emotional maternal abuse may significantly contribute to the emotional abuse experienced by Latina women in their lifetime. Methods Cross-sectional data including 316 women was analyzed using mediation and logistic regression. Results Overall, 7.1% of mothers and 24.1% of daughters abused drugs; and, 19.5% of daughters were emotionally abused by their mothers. Mother's attachment to her daughter mediated the association between mother's drug abuse and emotionally abusing her adult daughter (Indirect effect: 0.863). Discussion Latina women can serve as perpetrators of emotional abuse of their adult children. Since drug-abusing daughters are more likely to be victims of emotional abuse by their mothers and drug-abusing mothers are more likely to abuse their daughters, drug-rehabilitation practitioners should incorporate a family abuse component into rehabilitation programs. PMID:26614091

  19. Effect of aspirin on tumour cell colony formation and evolution.

    PubMed

    Wodarz, Dominik; Goel, Ajay; Boland, C Richard; Komarova, Natalia L

    2017-09-01

    Aspirin is known to reduce the risk of colorectal cancer (CRC) incidence, but the underlying mechanisms are not fully understood. In a previous study, we quantified the in vitro growth kinetics of different CRC tumour cell lines treated with varying doses of aspirin, measuring the rate of cell division and cell death. Here, we use these measured parameters to calculate the chances of successful clonal expansion and to determine the evolutionary potential of the tumour cell lines in the presence and absence of aspirin. The calculations indicate that aspirin increases the probability that a single tumour cell fails to clonally expand. Further, calculations suggest that aspirin increases the evolutionary potential of an expanding tumour cell colony. An aspirin-treated tumour cell population is predicted to result in the accumulation of more mutations (and is thus more virulent and more difficult to treat) than a cell population of the same size that grew without aspirin. This indicates a potential trade-off between delaying the onset of cancer and increasing its evolutionary potential through chemoprevention. Further work needs to investigate to what extent these findings apply to in vivo settings, and to what degree they contribute to the epidemiologically documented aspirin-mediated protection. © 2017 The Author(s).

  20. Raman scattering evidence of hydrohalite formation on frozen yeast cells.

    PubMed

    Okotrub, K A; Surovtsev, N V

    2013-02-01

    We studied yeast cells in physiological solution during freezing by Raman microspectroscopy technique. The purpose was to find out the origin of a sharp peak near ∼3430cm(-1) in Raman spectrum of frozen mammalian cells, observed earlier (J. Dong et al., Biophys. J. 99 (2010) 2453), which presumably could be used as an indicator of intracellar ice appearance. We have shown that this line (actually doublet of 3408 and 3425cm(-1)) corresponds to Raman spectrum of hydrohalite (NaCl⋅2H(2)O), which is formed as the result of the eutectic crystallization of the liquid solution around the cells. We also show that the spatial distribution of hydrohalite in the sample significantly depends on the cooling rate. At lower cooling rate (1°C/min), products of eutectic crystallization form layer on the cell surface which thickness varies for different cells and can reach ∼1μm in thickness. At higher cooling rate (20°C/min), the hydrohalite distribution appears more homogeneous, in the sample, and the eutectic crystallization layer around the cells was estimated to be less than ∼20nm. These experimental results are consistent with scenarios predicted by the two-factor hypothesis for freezing induced cell injury. This work demonstrates a potential of Raman microspectroscopy to study peculiarities of the eutectic crystallization around single cells in vivo with the high spatial resolution.

  1. Robust optimization of a mathematical model to design a dynamic cell formation problem considering labor utilization

    NASA Astrophysics Data System (ADS)

    Vafaeinezhad, Moghadaseh; Kia, Reza; Shahnazari-Shahrezaei, Parisa

    2016-11-01

    Cell formation (CF) problem is one of the most important decision problems in designing a cellular manufacturing system includes grouping machines into machine cells and parts into part families. Several factors should be considered in a cell formation problem. In this work, robust optimization of a mathematical model of a dynamic cell formation problem integrating CF, production planning and worker assignment is implemented with uncertain scenario-based data. The robust approach is used to reduce the effects of fluctuations of the uncertain parameters with regards to all possible future scenarios. In this research, miscellaneous cost parameters of the cell formation and demand fluctuations are subject to uncertainty and a mixed-integer nonlinear programming model is developed to formulate the related robust dynamic cell formation problem. The objective function seeks to minimize total costs including machine constant, machine procurement, machine relocation, machine operation, inter-cell and intra-cell movement, overtime, shifting labors between cells and inventory holding. Finally, a case study is carried out to display the robustness and effectiveness of the proposed model. The tradeoff between solution robustness and model robustness is also analyzed in the obtained results.

  2. Endothelial cell motility, coordination and pattern formation during vasculogenesis.

    PubMed

    Czirok, Andras

    2013-01-01

    How vascular networks assemble is a fundamental problem of developmental biology that also has medical importance. To explain the organizational principles behind vascular patterning, we must understand how can tissue level structures be controlled through cell behavior patterns like motility and adhesion that, in turn, are determined by biochemical signal transduction processes? We discuss the various ideas that have been proposed as mechanisms for vascular network assembly: cell motility guided by extracellular matrix alignment (contact guidance), chemotaxis guided by paracrine and autocrine morphogens, and multicellular sprouting guided by cell-cell contacts. All of these processes yield emergent patterns, thus endothelial cells can form an interconnected structure autonomously, without guidance from an external pre-pattern. © 2013 Wiley Periodicals, Inc.

  3. Laser-based techniques for living cell pattern formation

    NASA Astrophysics Data System (ADS)

    Hopp, Béla; Smausz, Tomi; Papdi, Bence; Bor, Zsolt; Szabó, András; Kolozsvári, Lajos; Fotakis, Costas; Nógrádi, Antal

    2008-10-01

    In the production of biosensors or artificial tissues a basic step is the immobilization of living cells along the required pattern. In this paper the ability of some promising laser-based methods to influence the interaction between cells and various surfaces is presented. In the first set of experiments laser-induced patterned photochemical modification of polymer foils was used to achieve guided adherence and growth of cells to the modified areas: (a) Polytetrafluoroethylene was irradiated with ArF excimer laser ( λ=193 nm, FWHM=20 ns, F=9 mJ/cm2) in presence of triethylene tetramine liquid photoreagent; (b) a thin carbon layer was produced by KrF excimer laser ( λ=248 nm, FWHM=30 ns, F=35 mJ/cm2) irradiation on polyimide surface to influence the cell adherence. It was found that the incorporation of amine groups in the PTFE polymer chain instead of the fluorine atoms can both promote and prevent the adherence of living cells (depending on the applied cell types) on the treated surfaces, while the laser generated carbon layer on polyimide surface did not effectively improve adherence. Our attempts to influence the cell adherence by morphological modifications created by ArF laser irradiation onto polyethylene terephtalate surface showed a surface roughness dependence. This method was effective only when the Ra roughness parameter of the developed structure did not exceed the 0.1 micrometer value. Pulsed laser deposition with femtosecond KrF excimer lasers ( F=2.2 J/cm2) was effectively used to deposit structured thin films from biomaterials (endothelial cell growth supplement and collagen embedded in starch matrix) to promote the adherence and growth of cells. These results present evidence that some surface can be successfully altered to induce guided cell growth.

  4. Morphology and ultrastructure of Interfilum and Klebsormidium (Klebsormidiales, Streptophyta) with special reference to cell division and thallus formation

    PubMed Central

    Mikhailyuk, Tatiana; Holzinger, Andreas; Massalski, Andrzej; Karsten, Ulf

    2014-01-01

    Representatives of the closely related genera, Interfilum and Klebsormidium, are characterized by unicells, dyads or packets in Interfilum and contrasting uniseriate filaments in Klebsormidium. According to the literature, these distinct thallus forms originate by different types of cell division, sporulation (cytogony) versus vegetative cell division (cytotomy), but investigations of their morphology and ultrastructure show a high degree of similarity. Cell walls of both genera are characterized by triangular spaces between cell walls of neighbouring cells and the parental wall or central space among the walls of a cell packet, exfoliations and projections of the parental wall and cap-like and H-like fragments of the cell wall. In both genera, each cell has its individual cell wall and it also has part of the common parental wall or its remnants. Therefore, vegetative cells of Interfilum and Klebsormidium probably divide by the same type of cell division (sporulation-like). Various strains representing different species of the two genera are characterized by differences in cell wall ultrastructure, particularly the level of preservation, rupture or gelatinization of the parental wall surrounding the daughter cells. The differing morphologies of representatives of various lineages result from features of the parental wall during cell separation and detachment. Cell division in three planes (usual in Interfilum and a rare event in Klebsormidium) takes place in spherical or short cylindrical cells, with the chloroplast positioned perpendicularly or obliquely to the filament (dyad) axis. The morphological differences are mainly a consequence of differing fates of the parental wall after cell division and detachment. The development of different morphologies within the two genera mostly depends on characters such as the shape of cells, texture of cell walls, mechanical interactions between cells and the influence of environmental conditions. PMID:26504365

  5. VE-cadherin interacts with cell polarity protein Pals1 to regulate vascular lumen formation.

    PubMed

    Brinkmann, Benjamin F; Steinbacher, Tim; Hartmann, Christian; Kummer, Daniel; Pajonczyk, Denise; Mirzapourshafiyi, Fatemeh; Nakayama, Masanori; Weide, Thomas; Gerke, Volker; Ebnet, Klaus

    2016-09-15

    Blood vessel tubulogenesis requires the formation of stable cell-to-cell contacts and the establishment of apicobasal polarity of vascular endothelial cells. Cell polarity is regulated by highly conserved cell polarity protein complexes such as the Par3-aPKC-Par6 complex and the CRB3-Pals1-PATJ complex, which are expressed by many different cell types and regulate various aspects of cell polarity. Here we describe a functional interaction of VE-cadherin with the cell polarity protein Pals1. Pals1 directly interacts with VE-cadherin through a membrane-proximal motif in the cytoplasmic domain of VE-cadherin. VE-cadherin clusters Pals1 at cell-cell junctions. Mutating the Pals1-binding motif in VE-cadherin abrogates the ability of VE-cadherin to regulate apicobasal polarity and vascular lumen formation. In a similar way, deletion of the Par3-binding motif at the C-terminus of VE-cadherin impairs apicobasal polarity and vascular lumen formation. Our findings indicate that the biological activity of VE-cadherin in regulating endothelial polarity and vascular lumen formation is mediated through its interaction with the two cell polarity proteins Pals1 and Par3.

  6. miR-17 inhibition enhances the formation of kidney cancer spheres with stem cell/tumor initiating cell properties

    PubMed Central

    Lichner, Zsuzsanna; Saleh, Carol; Subramaniam, Venkateswaran; Seivwright, Annetta; Prud'homme, Gerald Joseph; Yousef, George Makram

    2015-01-01

    Renal cell carcinoma (RCC) is an aggressive disease, with 35% chance of metastasis. The ‘cancer stem cell’ hypothesis suggests that a subset of cancer cells possess stem cell properties and is crucial in tumor initiation, metastasis and treatment resistance. We isolated RCC spheres and showed that they exhibit cancer stem cell/tumor initiating cell-like properties including the formation of self-renewing spheres, high tumorigenicity and the ability to differentiate to cell types of the original tumor. Spheres showed increased expression of stem cell-related transcription factors and mesenchymal markers.  miRNAs were differentially expressed between RCC spheres and their parental cells. Inhibition of miR-17 accelerated the formation of RCC spheres which shared molecular characteristics with the spontaneous RCC spheres. Target prediction pointed out TGFβ pathway activation as a possible mechanism to drive RCC sphere formation. We demonstrate that miR-17 overexpression interferes with the TGFβ-EMT axis and hinders RCC sphere formation; and validated TGFBR2 as a direct and biologically relevant target during this process. Thus, a single miRNA may have an impact on the formation of highly tumorigenic cancer spheres of kidney cancer. PMID:25011053

  7. A Theoretical Model of Jigsaw-Puzzle Pattern Formation by Plant Leaf Epidermal Cells

    PubMed Central

    Higaki, Takumi; Kutsuna, Natsumaro; Akita, Kae; Takigawa-Imamura, Hisako; Yoshimura, Kenji; Miura, Takashi

    2016-01-01

    Plant leaf epidermal cells exhibit a jigsaw puzzle–like pattern that is generated by interdigitation of the cell wall during leaf development. The contribution of two ROP GTPases, ROP2 and ROP6, to the cytoskeletal dynamics that regulate epidermal cell wall interdigitation has already been examined; however, how interactions between these molecules result in pattern formation remains to be elucidated. Here, we propose a simple interface equation model that incorporates both the cell wall remodeling activity of ROP GTPases and the diffusible signaling molecules by which they are regulated. This model successfully reproduces pattern formation observed in vivo, and explains the counterintuitive experimental results of decreased cellulose production and increased thickness. Our model also reproduces the dynamics of three-way cell wall junctions. Therefore, this model provides a possible mechanism for cell wall interdigitation formation in vivo. PMID:27054467

  8. [Inhibitory effect of ilexpernoside C from Ilex pernyi on aggregated LDL-induced foam cells formation].

    PubMed

    Lun, Qi-Xing; Liu, Bing-Lin; Li, Jun; Zhao, Yun-Fang; Zheng, Jiao; Tu, Peng-Fei

    2016-02-01

    The aggregation of macrophage-derived foam cells on vascular wall is considered to be a main cause of atherosclerosis. In the present study, we evaluated the inhibitory effect of the compound ilexpernoside C (IC1) extracted from Ilex pernyi (Aquifoliaceae) on foam cell formation in THP-1 macrophages cells which were induced by low density lipoproteins aggregates (LDL aggregates). Results showed that IC1 could significantly inhibit the formation of foam cells. The analysis on related receptors of foam cells indicated that IC1 could significantly decrease the expression of low density lipoprotein-related receptor 1(LRP1). Therefore, these findings indicated that IC1 inhibited the formation of foam cells by inhibiting endocytosis of macrophages, thus it may act as a potential anti-atherosclerotic agent. Copyright© by the Chinese Pharmaceutical Association.

  9. Like Mother, Like Daughter? Dietary and Non-Dietary Bone Fracture Risk Factors in Mothers and Their Daughters

    PubMed Central

    SOBAS, Kamila; WADOLOWSKA, Lidia; SLOWINSKA, Malgorzata Anna; CZLAPKA-MATYASIK, Magdalena; WUENSTEL, Justyna; NIEDZWIEDZKA, Ewa

    2015-01-01

    Background: The aim of this study was to demonstrate similarities and differences between mothers and daughters regarding dietary and non-dietary risk factors for bone fractures and osteoporosis. Methods: The study was carried out in 2007–2010 on 712 mothers (29–59 years) and daughters (12–21 years) family pairs. In the sub-sample (170 family pairs) bone mineral density (BMD) was measured for the forearm by dual-energy x-ray absorptiometry (DXA). The consumption of dairy products was determined with a semi-quantitative food frequency questionnaire (ADOS-Ca) and calcium intake from the daily diet was calculated. Results: The presence of risk factors for bone fractures in mothers and daughters was significantly correlated. The Spearman rank coefficient for dietary factors of fracture risk was 0.87 (P<0.05) in whole sub-sample, 0.94 (P<0.05) in bottom tercile of BMD, 0.82 (P<0.05) in middle tercile of BMD, 0.54 (P>0.05) in upper tercile of BMD and for non-dietary factors of fracture risk was 0.83 (P<0.05) in whole sub-sample, 0.86 (P<0.05) in bottom tercile of BMD, 0.93 (P<0.05) in middle tercile of BMD, 0.65 (P<0.05) in upper tercile of BMD. Conclusions: Our results confirm the role of the family environment for bone health and document the stronger effect of negative factors of the family environment as compared to other positive factors on bone fracture risk. PMID:26576372

  10. Functional Anatomy of T Cell Activation and Synapse Formation

    PubMed Central

    Fooksman, David R.; Vardhana, Santosh; Vasiliver-Shamis, Gaia; Liese, Jan; Blair, David; Waite, Janelle; Sacristán, Catarina; Victora, Gabriel; Zanin-Zhorov, Alexandra; Dustin, Michael L.

    2010-01-01

    T cell activation and function require a structured engagement of antigen-presenting cells. These cell contacts are characterized by two distinct dynamics in vivo: transient contacts resulting from promigratory junctions called immunological kinapses or prolonged contacts from stable junctions called immunological synapses. Kinapses operate in the steady state to allow referencing to self-peptide-MHC (pMHC) and searching for pathogen-derived pMHC. Synapses are induced by T cell receptor (TCR) interactions with agonist pMHC under specific conditions and correlate with robust immune responses that generate effector and memory T cells. High-resolution imaging has revealed that the synapse is highly coordinated, integrating cell adhesion, TCR recognition of pMHC complexes, and an array of activating and inhibitory ligands to promote or prevent T cell signaling. In this review, we examine the molecular components, geometry, and timing underlying kinapses and synapses. We integrate recent molecular and physiological data to provide a synthesis and suggest ways forward. PMID:19968559

  11. Trunk neural crest cells: formation, migration and beyond.

    PubMed

    Vega-Lopez, Guillermo A; Cerrizuela, Santiago; Aybar, Manuel J

    2017-01-01

    Neural crest cells (NCCs) are a multipotent, migratory cell population that generates an astonishingly diverse array of cell types during vertebrate development. The trunk neural crest has long been considered of particular significance. First, it has been held that the trunk neural crest has a morphogenetic role, acting to coordinate the development of the peripheral nervous system, secretory cells of the endocrine system and pigment cells of the skin. Second, the trunk neural crest additionally has skeletal potential. However, it has been demonstrated that a key role of the trunk neural crest streams is to organize the innervation of the intestine. Although trunk NCCs have a limited capacity for self-renewal, sometimes they become neural-crest-derived tumor cells and reveal the fact that that NCCs and tumor cells share the same molecular machinery. In this review we describe the routes taken by trunk NCCs and consider the signals and cues that pattern these trajectories. We also discuss recent advances in the characterization of the properties of trunk NCCs for various model organisms in order to highlight common themes. Finally, looking to the future, we discuss the need to translate the wealth of data from animal studies to the clinical area in order to develop treatments for neural crest-related human diseases.

  12. Mechanisms underlying the formation of induced pluripotent stem cells.

    PubMed

    González, Federico; Huangfu, Danwei

    2016-01-01

    Human pluripotent stem cells (hPSCs) offer unique opportunities for studying human biology, modeling diseases, and therapeutic applications. The simplest approach so far to generate human PSC lines is through reprogramming of somatic cells from an individual by defined factors, referred to simply as reprogramming. Reprogramming circumvents the ethical controversies associated with human embryonic stem cells (hESCs) and nuclear transfer hESCs (nt-hESCs), and the resulting induced pluripotent stem cells (hiPSCs) retain the same basic genetic makeup as the somatic cell used for reprogramming. Since the first report of iPSCs by Takahashi and Yamanaka (Cell 2006, 126:663-676), the molecular mechanisms of reprogramming have been extensively investigated. A better mechanistic understanding of reprogramming is fundamental not only to iPSC biology and improving the quality of iPSCs for therapeutic use, but also to our understanding of the molecular basis of cell identity, pluripotency, and plasticity. Here, we summarize the genetic, epigenetic, and cellular events during reprogramming, and the roles of various factors identified thus far in the reprogramming process. WIREs Dev Biol 2016, 5:39-65. doi: 10.1002/wdev.206 For further resources related to this article, please visit the WIREs website.

  13. CD22 is required for formation of memory B cell precursors within germinal centers

    PubMed Central

    Chappell, Craig P.; Draves, Kevin E.

    2017-01-01

    CD22 is a BCR co-receptor that regulates B cell signaling, proliferation and survival and is required for T cell-independent Ab responses. To investigate the role of CD22 during T cell-dependent (TD) Ab responses and memory B cell formation, we analyzed Ag-specific B cell responses generated by wild-type (WT) or CD22-/- B cells following immunization with a TD Ag. CD22-/- B cells mounted normal early Ab responses yet failed to generate either memory B cells or long-lived plasma cells, whereas WT B cells formed both populations. Surprisingly, B cell expansion and germinal center (GC) differentiation were comparable between WT and CD22-/- B cells. CD22-/- B cells, however, were significantly less capable of generating a population of CXCR4hiCD38hi GC B cells, which we propose represent memory B cell precursors within GCs. These results demonstrate a novel role for CD22 during TD humoral responses evident during primary GC formation and underscore that CD22 functions not only during B cell maturation but also during responses to both TD and T cell-independent antigens. PMID:28346517

  14. The co-injection of somatic cells with embryonic stem cells affects teratoma formation and the properties of teratoma-derived stem cell-like cells.

    PubMed

    Gong, Seung Pyo; Kim, Boyun; Kwon, Hyo Sook; Yang, Woo Sub; Jeong, Jae-Wook; Ahn, Jiyeon; Lim, Jeong Mook

    2014-01-01

    The aim of this study was to assess the biological reactions triggered by stem cell transplantation related to phenotypic alteration, host-to-cell response, chromosomal stability, transcriptional alteration, and stem cell-like cell re-expansion. B6CBAF1 mouse embryonic stem cells (ESCs) were injected subcutaneously into homologous or heterologous (B6D2F1) recipients, and heterologous injections were performed with or without co-injection of B6D2F1 fetal fibroblasts. All homologous injections resulted in teratoma formation, whereas a sharp decrease in formation was detected after heterologous injection (100 vs. 14%; p<0.05). The co-injection of somatic cells in heterologous injections enhanced teratoma formation significantly (14 vs. 75%; p<0.05). Next, ESC-like cell colonies with the same genotype as parental ESCs were formed by culturing teratoma-dissociated cells. Compared with parental ESCs, teratoma-derived ESC-like cells exhibited significantly increased aneuploidy, regardless of homologous or heterologous injections. Repopulation of the parental ESCs was the main factor that induced chromosomal instability, whereas the co-injection of somatic cells did not restore chromosomal normality. Different genes were expressed in the parental ESCs and teratoma-derived ESC-like cells; the difference was larger with parental vs. heterologous than parental vs. homologous co-injections. The co-injection of somatic cells decreased this difference further. In conclusion, the host-to-cell interactions triggered by ESC transplantation could be modulated by co-injection with somatic cells. A mouse model using homologous or heterologous transplantation of stem cells could help monitor cell adaptability and gene expression after injection.

  15. Inducible and Constitutive β-Galactosidase Formation in Cells Recovering from Protein Synthesis Inhibition1

    PubMed Central

    Soreq, Hermona; Kaplan, Ruth

    1971-01-01

    Inducible and constitutive β-galactosidase formation and radioactive amino acid incorporation were measured in cells recovering from various treatments which inhibit protein synthesis in the cell. Undelayed β-galactosidase formation was found in stringent auxotrophs recovering from amino acid starvation, in cells recovering from glycerol or potassium starvation, and in bacteria recovering from puromycin treatment. Delayed β-galactosidase formation was found in relaxed auxotrophs recovering from amino acid starvation and in prototrophs recovering from chloramphenicol or from tetracycline treatment. The length of this delay was directly proportional to the duration of the treatment. All cells recovering from the various treatments exhibited a slightly decreased rate of β-galactosidase formation and an increase in radioactive amino acid incorporation. PMID:4945186

  16. Becoming the Parent of a GLB Son or Daughter

    PubMed Central

    GRAFSKY, ERIKA L.

    2014-01-01

    Recent research has documented the importance of parental reactions to disclosure for sexual minority youth (SMY) (e.g., Ryan, Huebner, Diaz, & Sanchez, 2009). The purpose of this study was to develop a deeper understanding of the parent perspective of the disclosure to family experience of SMY ages 14-21. In-depth interviews were conducted with eight parents in the United States who had experienced a child disclose their lesbian, gay, or bisexual (LGB) orientation to them. Constructivist grounded theory and symbolic interaction theory informed the methodology and data analysis for the project. Analysis revealed that the process of becoming the parent of an LGB son or daughter is an appropriate narrative to conceptualize the parental experience of the disclosure to family process. The findings highlight how disclosure introduces new roles into the existing family system, which affects the consideration and interpretation of the salience of particular identities, such as being the parent of an LGB son or daughter. Understanding how parents experience the disclosure to family process - particularly, how they understand and re-envision the meaning of being a parent - is crucial for research and intervention to help families become supportive of SMY. Limitations and suggestions for future research are presented. PMID:25685111

  17. Retention of Radium-225 and Its Daughter Radioisotopes in Bone

    SciTech Connect

    Mirzadeh, Saed; Garland, Marc A; Kennel, Steve J

    2008-01-01

    The natural bone seeking tendency of Ra+2, similar to the other alkali metal ions, coupled with the short range high LET of -particle emissions are an ideal combination for localized therapy, and recently 11.4 d 223Ra has been studied for therapy of bone tumors in rats and humans [1,2]. Actinium-225 is also an attractive radioisotope for endo-radiotherapy in a single decay chain from 225Ac, over 26 MeV (~70% of total) is carried by four - particles ranging in energy from 5.7 to 8.4 MeV [3,4]. Although Ac+3 does not home naturally to bone (rather to liver) [5,6], its parent, 225Ra ( -, t1/2 = 15 d), can be used as an in vivo source for 225Ac. A pivotal question for the 225Ra/225Ac in vivo generator system is whether translocation of the daughter nuclei occurs prior to or following the uptake of 225Ra by the bone. In order to assess potential collateral damage to soft tissue organs it is essential to quantitate the extent to which 225Ac is retained in organs following the uptake of 225Ra. We have attempted to answer these questions by investigating the extent of translocation of 225Ac and 213Bi, two daughter radioisotopes of 225Ra, following retention of initially pure 225Ra in bone in normal mice.

  18. Cluster emissions with ? daughter from neutron-rich nuclei

    NASA Astrophysics Data System (ADS)

    Kumar, Satish; Batra, J. S.; Gupta, Raj K.

    1996-02-01

    Cluster emissions from neutron-rich 0954-3899/22/2/006/img2, and 0954-3899/22/2/006/img3 nuclei are studied within the preformed cluster model of Malik and Gupta. Q-value estimates of the decays selected on the basis of shell effects in binding energies and their relative preformation probabilities show that these nuclei are stable (Q<0) against 0954-3899/22/2/006/img4 and 0954-3899/22/2/006/img5 decays and all the metastable (Q>0) decays are of non-alpha-like heavy clusters. The most probable decays (minimum half-life times) are the ones with a doubly magic 0954-3899/22/2/006/img6 nucleus as the daughter nucleus, arising due to the WKB penetrability. Compared to the presently measurable alpha-like cluster decays of the corresponding neutron-deficient parents into a 0954-3899/22/2/006/img7 daughter nucleus, these decays are suppressed by many orders of magnitude.

  19. Latina daughters' childbearing attitudes: the role of maternal expectations and education communication.

    PubMed

    Mireles-Rios, Rebeca; Romo, Laura F

    2014-05-01

    Adolescent girls' and their mothers' expectations for their daughters' college attainment, mother-daughter communication about education, and daughters' early childbearing attitudes were examined in 146 U.S.-raised Latina girls (mean age = 14.4 years) and their mostly immigrant mothers. Through structural equation modeling, we tested in the present study a 3-path mediating model to identify mechanisms underlying the association between maternal expectations and daughters' childbearing attitudes. There was evidence to suggest that self-reported mother-daughter communication about education and the daughters' achievement orientation, as measured by their expectations to attend college and self-reported grades, were 2 mediating factors by which maternal college expectations for daughters were linked to their childbearing attitudes. Specifically, higher maternal expectations were associated with increased reported education communication, which in turn was associated with higher achievement orientation. In turn, higher achievement orientation was associated with the girls' desire to have a first child at older ages and more rejecting attitudes toward the prospect of an adolescent pregnancy. The findings underscore the crucial role that Latina mothers can play in both supporting their daughters' goals to pursue higher education and motivating daughters to avoid early childbearing. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  20. Communication about sex and HPV among Puerto Rican mothers and daughters.

    PubMed

    Colón-López, Vivian; Fernández-Espada, Natalie; Vélez, Camille; Gonzalez, Velda J; Diaz-Toro, Elba C; Calo, William A; Savas, Lara S; Pattatucci, Angela; Fernández, María E

    2017-08-01

    Although opportunities to vaccinate against human papillomavirus (HPV) are available, vaccination rates in Puerto Rico remain low. Communication between parents and adolescents about sexual topics may influence decisions about HPV vaccination uptake, particularly among young women; yet, few studies have addressed this issue. This qualitative study explored Puerto Rican mothers' and daughters' communication on sex-related topics, and HPV, including the HPV vaccine. Thirty participants, including 9 mothers and 21 daughters, participated in seven focus groups. Participants were divided into groups of mothers and daughters, and further stratified by vaccination status. Transcripts were analyzed using a modified grounded theory approach to identify emergent themes. Focus group data revealed four main themes: (1) limited parent-daughter communication about sex-related topics; (2) daughters' discomfort discussing sex-related topics with their parents; (3) parental focus on abstinence; and, (4) limited parent-daughter communication about HPV and the HPV vaccine. Although daughters in this study struggled with feelings of embarrassment, invasion of privacy, encouragement of abstinence, and the fear of parents' reaction to them being sexually active prior to marriage, they also recognized the need to increase the parent-daughter communication about sex-related topics including HPV and the HPV vaccine. Educational efforts should target both daughters and parents to increase communication skills and self-efficacy and to enable them to discuss sexual health in open and nonjudgmental conversations.

  1. Measurements of the deposition rates of radon daughters on indoor surfaces

    SciTech Connect

    Toohey, R.E.; Essling, M.A.; Rundo, J.; Hengde, W.

    1983-01-01

    The deposition rates of radon daughters on indoor surfaces have been measured by exposing the window of a proportional counter to the air of a house with high concentrations of radon and its daughters. Deposition velocities for unattached RaA and RaB of approximately 4 mm sec/sup -1/ were obtained by dividing the deposition rates by the concentrations of unattached daughters in the air. These results agree with those obtained by other workers but are dependent on the assumptions made about the fractions of the daughters which are attached to the atmospheric aerosol.

  2. Directional Bleb Formation in Spherical Cells under Temperature Gradient

    PubMed Central

    Oyama, Kotaro; Arai, Tomomi; Isaka, Akira; Sekiguchi, Taku; Itoh, Hideki; Seto, Yusuke; Miyazaki, Makito; Itabashi, Takeshi; Ohki, Takashi; Suzuki, Madoka; Ishiwata, Shin'ichi

    2015-01-01

    Living cells sense absolute temperature and temporal changes in temperature using biological thermosensors such as ion channels. Here, we reveal, to our knowledge, a novel mechanism of sensing spatial temperature gradients within single cells. Spherical mitotic cells form directional membrane extensions (polar blebs) under sharp temperature gradients (≥∼0.065°C μm−1; 1.3°C temperature difference within a cell), which are created by local heating with a focused 1455-nm laser beam under an optical microscope. On the other hand, multiple nondirectional blebs are formed under gradual temperature gradients or uniform heating. During heating, the distribution of actomyosin complexes becomes inhomogeneous due to a break in the symmetry of its contractile force, highlighting the role of the actomyosin complex as a sensor of local temperature gradients. PMID:26200871

  3. Colony formation and interleukin 2 production by leukaemic human T cells.

    PubMed Central

    Krajewski, A S; Dewar, A E; Seidelin, P H; Murray, R

    1983-01-01

    PHA-induced colony formation and interleukin 2 (IL-2) production were studied in four patients with T cell leukaemia (three cases OKT4+/T helper and one case OKT8+/T cytotoxic suppressor). Cases of T helper cell leukaemia showed colony formation that was comparable to normal purified blood T cells and was not dependent on the addition of conditioned medium, containing IL-2 activity, to cultures. In contrast the T suppressor cell leukaemia formed colonies only when cultures were supplemented with IL-2 containing medium. When IL-2 production by PHA stimulated cells was measured culture supernatants from the three T helper cell leukaemias all showed normal or high levels of activity, when compared to normal blood mononuclear cells, whereas the T suppressor cell leukaemia showed no activity. PMID:6604606

  4. Matrix elasticity of void-forming hydrogels controls transplanted-stem-cell-mediated bone formation

    NASA Astrophysics Data System (ADS)

    Huebsch, Nathaniel; Lippens, Evi; Lee, Kangwon; Mehta, Manav; Koshy, Sandeep T.; Darnell, Max C.; Desai, Rajiv M.; Madl, Christopher M.; Xu, Maria; Zhao, Xuanhe; Chaudhuri, Ovijit; Verbeke, Catia; Kim, Woo Seob; Alim, Karen; Mammoto, Akiko; Ingber, Donald E.; Duda, Georg N.; Mooney, David J.

    2015-12-01

    The effectiveness of stem cell therapies has been hampered by cell death and limited control over fate. These problems can be partially circumvented by using macroporous biomaterials that improve the survival of transplanted stem cells and provide molecular cues to direct cell phenotype. Stem cell behaviour can also be controlled in vitro by manipulating the elasticity of both porous and non-porous materials, yet translation to therapeutic processes in vivo remains elusive. Here, by developing injectable, void-forming hydrogels that decouple pore formation from elasticity, we show that mesenchymal stem cell (MSC) osteogenesis in vitro, and cell deployment in vitro and in vivo, can be controlled by modifying, respectively, the hydrogel’s elastic modulus or its chemistry. When the hydrogels were used to transplant MSCs, the hydrogel’s elasticity regulated bone regeneration, with optimal bone formation at 60 kPa. Our findings show that biophysical cues can be harnessed to direct therapeutic stem cell behaviours in situ.

  5. Bacterial lipopolysaccharide induces osteoclast formation in RAW 264.7 macrophage cells

    SciTech Connect

    Islam, Shamima; Hassan, Ferdaus; Tumurkhuu, Gantsetseg; Dagvadorj, Jargalsaikhan; Koide, Naoki; Naiki, Yoshikazu; Mori, Isamu; Yoshida, Tomoaki; Yokochi, Takashi . E-mail: yokochi@aichi-med-u.ac.jp

    2007-08-24

    Lipopolysaccharide (LPS) is a potent bone resorbing factor. The effect of LPS on osteoclast formation was examined by using murine RAW 264.7 macrophage cells. LPS-induced the formation of multinucleated giant cells (MGC) in RAW 264.7 cells 3 days after the exposure. MGCs were positive for tartrate-resistant acid phosphatase (TRAP) activity. Further, MGC formed resorption pits on calcium-phosphate thin film that is a substrate for osteoclasts. Therefore, LPS was suggested to induce osteoclast formation in RAW 264.7 cells. LPS-induced osteoclast formation was abolished by anti-tumor necrosis factor (TNF)-{alpha} antibody, but not antibodies to macrophage-colony stimulating factor (M-CSF) and receptor activator of nuclear factor (NF)-{kappa}B ligand (RANKL). TNF-{alpha} might play a critical role in LPS-induced osteoclast formation in RAW 264.7 cells. Inhibitors of NF-{kappa}B and stress activated protein kinase (SAPK/JNK) prevented the LPS-induced osteoclast formation. The detailed mechanism of LPS-induced osteoclast formation is discussed.

  6. Numerical simulation of water transport and intracellular ice formation for freezing of endothelial cells.

    PubMed

    Zhao, G; Xu, Y; Ding, W P; Hu, M B

    2013-01-01

    Endothelial cell detachment may cause failure of blood vessel and corneal cryopreservation, and thus successful cryopreservation of endothelial cells is regarded to be the first step to optimize cryopreservation of endothelial cells containing tissues. In this study, the pre-determined biophysical parameters were incorporated into the model for intracellular ice formation (IIF) and the growth of intracellular ice crystals (ICG) to calculate cell water loss, supercooling of intracellular solution, intracellular ice formation and the growth of intracellular ice crystals. The optimal protocols were determined according to the combination effect of both solution injury and IIF injury.

  7. VE-cadherin interacts with cell polarity protein Pals1 to regulate vascular lumen formation

    PubMed Central

    Brinkmann, Benjamin F.; Steinbacher, Tim; Hartmann, Christian; Kummer, Daniel; Pajonczyk, Denise; Mirzapourshafiyi, Fatemeh; Nakayama, Masanori; Weide, Thomas; Gerke, Volker; Ebnet, Klaus

    2016-01-01

    Blood vessel tubulogenesis requires the formation of stable cell-to-cell contacts and the establishment of apicobasal polarity of vascular endothelial cells. Cell polarity is regulated by highly conserved cell polarity protein complexes such as the Par3-aPKC-Par6 complex and the CRB3-Pals1-PATJ complex, which are expressed by many different cell types and regulate various aspects of cell polarity. Here we describe a functional interaction of VE-cadherin with the cell polarity protein Pals1. Pals1 directly interacts with VE-cadherin through a membrane-proximal motif in the cytoplasmic domain of VE-cadherin. VE-cadherin clusters Pals1 at cell–cell junctions. Mutating the Pals1-binding motif in VE-cadherin abrogates the ability of VE-cadherin to regulate apicobasal polarity and vascular lumen formation. In a similar way, deletion of the Par3-binding motif at the C-terminus of VE-cadherin impairs apicobasal polarity and vascular lumen formation. Our findings indicate that the biological activity of VE-cadherin in regulating endothelial polarity and vascular lumen formation is mediated through its interaction with the two cell polarity proteins Pals1 and Par3. PMID:27466317

  8. Mechanical Model of Geometric Cell and Topological Algorithm for Cell Dynamics from Single-Cell to Formation of Monolayered Tissues with Pattern

    PubMed Central

    Kachalo, Sëma; Naveed, Hammad; Cao, Youfang; Zhao, Jieling; Liang, Jie

    2015-01-01

    Geometric and mechanical properties of individual cells and interactions among neighboring cells are the basis of formation of tissue patterns. Understanding the complex interplay of cells is essential for gaining insight into embryogenesis, tissue development, and other emerging behavior. Here we describe a cell model and an efficient geometric algorithm for studying the dynamic process of tissue formation in 2D (e.g. epithelial tissues). Our approach improves upon previous methods by incorporating properties of individual cells as well as detailed description of the dynamic growth process, with all topological changes accounted for. Cell size, shape, and division plane orientation are modeled realistically. In addition, cell birth, cell growth, cell shrinkage, cell death, cell division, cell collision, and cell rearrangements are now fully accounted for. Different models of cell-cell interactions, such as lateral inhibition during the process of growth, can be studied in detail. Cellular pattern formation for monolayered tissues from arbitrary initial conditions, including that of a single cell, can also be studied in detail. Computational efficiency is achieved through the employment of a special data structure that ensures access to neighboring cells in constant time, without additional space requirement. We have successfully generated tissues consisting of more than 20,000 cells starting from 2 cells within 1 hour. We show that our model can be used to study embryogenesis, tissue fusion, and cell apoptosis. We give detailed study of the classical developmental process of bristle formation on the epidermis of D. melanogaster and the fundamental problem of homeostatic size control in epithelial tissues. Simulation results reveal significant roles of solubility of secreted factors in both the bristle formation and the homeostatic control of tissue size. Our method can be used to study broad problems in monolayered tissue formation. Our software is publicly

  9. Differentiated cytoplasmic granule formation in quiescent and non-quiescent cells upon chronological aging

    PubMed Central

    Lee, Hsin-Yi; Cheng, Kuo-Yu; Chao, Jung-Chi; Leu, Jun-Yi

    2016-01-01

    Stationary phase cultures represent a complicated cell population comprising at least two different cell types, quiescent (Q) and non-quiescent (NQ) cells. Q and NQ cells have different lifespans and cell physiologies. However, less is known about the organization of cytosolic protein structures in these two cell types. In this study, we examined Q and NQ cells for the formation of several stationary phase-prevalent granule structures including actin bodies, proteasome storage granules, stress granules, P-bodies, the compartment for unconventional protein secretion (CUPS), and Hsp42-associated stationary phase granules (Hsp42-SPGs). Most of these structures preferentially form in NQ cells, except for Hsp42-SPGs, which are enriched in Q cells. When nutrients are provided, NQ cells enter mitosis less efficiently than Q cells, likely due to the time requirement for reorganizing some granule structures. We observed that heat shock-induced misfolded proteins often colocalize to Hsp42-SPGs, and Q cells clear these protein aggregates more efficiently, suggesting that Hsp42-SPGs may play an important role in the stress resistance of Q cells. Finally, we show that the cell fate of NQ cells is largely irreversible even if they are allowed to reenter mitosis. Our results reveal that the formation of different granule structures may represent the early stage of cell type differentiation in yeast stationary phase cultures. PMID:28357341

  10. RNA processing body (P-body) dynamics in mesophyll protoplasts re-initiating cell division.

    PubMed

    Bhullar, Dilbag S; Sheahan, Michael B; Rose, Ray J

    2016-12-07

    The ability of plants to regenerate lies in the capacity of differentiated cells to reprogram and re-enter the cell cycle. Reprogramming of cells requires changes in chromatin organisation and gene expression. However, there has been less focus on changes at the post transcription level. We have investigated P-bodies, sites of post transcriptional gene regulation, in plant cell reprogramming in cultured mesophyll protoplasts; by using a YFP-VARICOSE (YFP-VCSc) translational fusion. We showed an early increase in P-body number and volume, followed by a decline, then a subsequent continued increase in P-body number and volume as cell division was initiated and cell proliferation continued. We infer that plant P-bodies have a role to play in reprogramming the mature cell and re-initiating the cell division cycle. The timing of the first phase is consistent with the degredation of messages no longer required, as the cell transits to the division state, and may also be linked to the stress response associated with division induction in cultured cells. The subsequent increase in P-body formation, with partitioning to the daughter cells during the division process, suggests a role in the cell cycle and its re-initiation in daughter cells. P-bodies were shown to be mobile in the cytoplasm and show actin-based motility which facilitates their post-transcriptional role and partitioning to daughter cells.

  11. Dynamics of vegetative cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana

    NASA Technical Reports Server (NTRS)

    Kuang, A.; Musgrave, M. E.

    1996-01-01

    Ultrastructural changes of pollen cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana were studied. The pollen cytoplasm develops a complicated ultrastructure and changes dramatically during these stages. Lipid droplets increase after generative cell formation and their organization and distribution change with the developmental stage. Starch grains in amyloplasts increase in number and size during generative and sperm cell formation and decrease at pollen maturity. The shape and membrane system of mitochondria change only slightly. Dictyosomes become very prominent, and numerous associated vesicles are observed during and after sperm cell formation. Endoplasmic reticulum appears extensively as stacks during sperm cell formation. Free and polyribosomes are abundant in the cytoplasm at all developmental stages although they appear denser at certain stages and in some areas. In mature pollen, all organelles are randomly distributed throughout the vegetative cytoplasm and numerous small particles appear. Organization and distribution of storage substances and appearance of these small particles during generative and sperm cell formation and pollen maturation are discussed.

  12. Dynamics of vegetative cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana

    NASA Technical Reports Server (NTRS)

    Kuang, A.; Musgrave, M. E.

    1996-01-01

    Ultrastructural changes of pollen cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana were studied. The pollen cytoplasm develops a complicated ultrastructure and changes dramatically during these stages. Lipid droplets increase after generative cell formation and their organization and distribution change with the developmental stage. Starch grains in amyloplasts increase in number and size during generative and sperm cell formation and decrease at pollen maturity. The shape and membrane system of mitochondria change only slightly. Dictyosomes become very prominent, and numerous associated vesicles are observed during and after sperm cell formation. Endoplasmic reticulum appears extensively as stacks during sperm cell formation. Free and polyribosomes are abundant in the cytoplasm at all developmental stages although they appear denser at certain stages and in some areas. In mature pollen, all organelles are randomly distributed throughout the vegetative cytoplasm and numerous small particles appear. Organization and distribution of storage substances and appearance of these small particles during generative and sperm cell formation and pollen maturation are discussed.

  13. Intact vinculin protein is required for control of cell shape, cell mechanics, and rac-dependent lamellipodia formation

    NASA Technical Reports Server (NTRS)

    Goldmann, Wolfgang H.; Ingber, Donald E.

    2002-01-01

    Studies were carried out using vinculin-deficient F9 embryonic carcinoma (gamma229) cells to analyze the relationship between structure and function within the focal adhesion protein vinculin, in the context of control of cell shape, cell mechanics, and movement. Atomic force microscopy studies revealed that transfection of the head (aa 1-821) or tail (aa 811-1066) domain of vinculin, alone or together, was unable to fully reverse the decrease in cell stiffness, spreading, and lamellipodia formation caused by vinculin deficiency. In contrast, replacement with intact vinculin completely restored normal cell mechanics and spreading regardless of whether its tyrosine phosphorylation site was deleted. Constitutively active rac also only induced extension of lamellipodia when microinjected into cells that expressed intact vinculin protein. These data indicate that vinculin's ability to physically couple integrins to the cytoskeleton, to mechanically stabilize cell shape, and to support rac-dependent lamellipodia formation all appear to depend on its intact three-dimensional structure.

  14. TCPs, WUSs, and WINDs: families of transcription factors that regulate shoot meristem formation, stem cell maintenance, and somatic cell differentiation.

    PubMed

    Ikeda, Miho; Ohme-Takagi, Masaru

    2014-01-01

    In contrast to somatic mammalian cells, which cannot alter their fate, plant cells can dedifferentiate to form totipotent callus cells and regenerate a whole plant, following treatment with specific phytohormones. However, the regulatory mechanisms and key factors that control differentiation-dedifferentiation and cell totipotency have not been completely clarified in plants. Recently, several plant transcription factors that regulate meristem formation and dedifferentiation have been identified and include members of the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP), WUSCHEL (WUS), and WOUND INDUCED DEDIFFERENTIATION (WIND1) families. WUS and WIND positively control plant cell totipotency, while TCP negatively controls it. Interestingly, TCP is a transcriptional activator that acts as a negative regulator of shoot meristem formation, and WUS is a transcriptional repressor that positively maintains totipotency of the stem cells of the shoot meristem. We describe here the functions of TCP, WUS, and WIND transcription factors in the regulation of differentiation-dedifferentiation by positive and negative transcriptional regulators.

  15. Intact vinculin protein is required for control of cell shape, cell mechanics, and rac-dependent lamellipodia formation

    NASA Technical Reports Server (NTRS)

    Goldmann, Wolfgang H.; Ingber, Donald E.

    2002-01-01

    Studies were carried out using vinculin-deficient F9 embryonic carcinoma (gamma229) cells to analyze the relationship between structure and function within the focal adhesion protein vinculin, in the context of control of cell shape, cell mechanics, and movement. Atomic force microscopy studies revealed that transfection of the head (aa 1-821) or tail (aa 811-1066) domain of vinculin, alone or together, was unable to fully reverse the decrease in cell stiffness, spreading, and lamellipodia formation caused by vinculin deficiency. In contrast, replacement with intact vinculin completely restored normal cell mechanics and spreading regardless of whether its tyrosine phosphorylation site was deleted. Constitutively active rac also only induced extension of lamellipodia when microinjected into cells that expressed intact vinculin protein. These data indicate that vinculin's ability to physically couple integrins to the cytoskeleton, to mechanically stabilize cell shape, and to support rac-dependent lamellipodia formation all appear to depend on its intact three-dimensional structure.

  16. Quantum dot-based molecular imaging of cancer cell growth using a clone formation assay.

    PubMed

    Geng, Xia-Fei; Fang, Min; Liu, Shao-Ping; Li, Yan

    2016-10-01

    This aim of the present study was to investigate clonal growth behavior and analyze the proliferation characteristics of cancer cells. The MCF‑7 human breast cancer cell line, SW480 human colon cancer cell line and SGC7901 human gastric cancer cell line were selected to investigate the morphology of cell clones. Quantum dot‑based molecular targeted imaging techniques (which stained pan‑cytokeratin in the cytoplasm green and Ki67 in the cell nucleus yellow or red) were used to investigate the clone formation rate, cell morphology, discrete tendency, and Ki67 expression and distribution in clones. From the cell clone formation assay, the MCF‑7, SW480 and SGC7901 cells were observed to form clones on days 6, 8 and 12 of cell culture, respectively. These three types of cells had heterogeneous morphology, large nuclear:cytoplasmic ratios, and conspicuous pathological mitotic features. The cells at the clone periphery formed multiple pseudopodium. In certain clones, cancer cells at the borderline were separated from the central cell clusters or presented a discrete tendency. With quantum dot‑based molecular targeted imaging techniques, cells with strong Ki67 expression were predominantly shown to be distributed at the clone periphery, or concentrated on one side of the clones. In conclusion, cancer cell clones showed asymmetric growth behavior, and Ki67 was widely expressed in clones of these three cell lines, with strong expression around the clones, or aggregated at one side. Cell clone formation assay based on quantum dots molecular imaging offered a novel method to study the proliferative features of cancer cells, thus providing a further insight into tumor biology.

  17. Quantum dot-based molecular imaging of cancer cell growth using a clone formation assay

    PubMed Central

    Geng, Xia-Fei; Fang, Min; Liu, Shao-Ping; Li, Yan

    2016-01-01

    This aim of the present study was to investigate clonal growth behavior and analyze the proliferation characteristics of cancer cells. The MCF-7 human breast cancer cell line, SW480 human colon cancer cell line and SGC7901 human gastric cancer cell line were selected to investigate the morphology of cell clones. Quantum dot-based molecular targeted imaging techniques (which stained pan-cytokeratin in the cytoplasm green and Ki67 in the cell nucleus yellow or red) were used to investigate the clone formation rate, cell morphology, discrete tendency, and Ki67 expression and distribution in clones. From the cell clone formation assay, the MCF-7, SW480 and SGC7901 cells were observed to form clones on days 6, 8 and 12 of cell culture, respectively. These three types of cells had heterogeneous morphology, large nuclear:cytoplasmic ratios, and conspicuous pathological mitotic features. The cells at the clone periphery formed multiple pseudopodium. In certain clones, cancer cells at the borderline were separated from the central cell clusters or presented a discrete tendency. With quantum dot-based molecular targeted imaging techniques, cells with strong Ki67 expression were predominantly shown to be distributed at the clone periphery, or concentrated on one side of the clones. In conclusion, cancer cell clones showed asymmetric growth behavior, and Ki67 was widely expressed in clones of these three cell lines, with strong expression around the clones, or aggregated at one side. Cell clone formation assay based on quantum dots molecular imaging offered a novel method to study the proliferative features of cancer cells, thus providing a further insight into tumor biology. PMID:27572664

  18. Collagen-IV supported embryoid bodies formation and differentiation from buffalo (Bubalus bubalis) embryonic stem cells

    SciTech Connect

    Taru Sharma, G.; Dubey, Pawan K.; Verma, Om Prakash; Pratheesh, M.D.; Nath, Amar; Sai Kumar, G.

    2012-08-03

    Graphical abstract: EBs formation, characterization and expression of germinal layers marker genes of in vivo developed teratoma using four different types of extracellular matrices. Highlights: Black-Right-Pointing-Pointer Collagen-IV matrix is found cytocompatible for EBs formation and differentiation. Black-Right-Pointing-Pointer Established 3D microenvironment for ES cells development and differentiation into three germ layers. Black-Right-Pointing-Pointer Collagen-IV may be useful as promising candidate for ES cells based therapeutic applications. -- Abstract: Embryoid bodies (EBs) are used as in vitro model to study early extraembryonic tissue formation and differentiation. In this study, a novel method using three dimensional extracellular matrices for in vitro generation of EBs from buffalo embryonic stem (ES) cells and its differentiation potential by teratoma formation was successfully established. In vitro derived inner cell masses (ICMs) of hatched buffalo blastocyst were cultured on buffalo fetal fibroblast feeder layer for primary cell colony formation. For generation of EBs, pluripotent ES cells were seeded onto four different types of extracellular matrices viz; collagen-IV, laminin, fibronectin and matrigel using undifferentiating ES cell culture medium. After 5 days of culture, ESCs gradually grew into aggregates and formed simple EBs having circular structures. Twenty-six days later, they formed cystic EBs over collagen matrix with higher EBs formation and greater proliferation rate as compared to other extracellular matrices. Studies involving histological observations, fluorescence microscopy and RT-PCR analysis of the in vivo developed teratoma revealed that presence of all the three germ layer derivatives viz. ectoderm (NCAM), mesoderm (Flk-1) and endoderm (AFP). In conclusion, the method described here demonstrates a simple and cost-effective way of generating EBs from buffalo ES cells. Collagen-IV matrix was found cytocompatible as it

  19. Biophysical Properties of Scaffolds Modulate Human Blood Vessel Formation from Circulating Endothelial Colony-Forming Cells

    NASA Astrophysics Data System (ADS)

    Critser, Paul J.; Yoder, Mervin C.

    A functional vascular system forms early in development and is continually remodeled throughout the life of the organism. Impairment to the regeneration or repair of this system leads to tissue ischemia, dysfunction, and disease. The process of vascular formation and remodeling is complex, relying on local microenvironmental cues, cytokine signaling, and multiple cell types to function properly. Tissue engineering strategies have attempted to exploit these mechanisms to develop functional vascular networks for the generation of artificial tissues and therapeutic strategies to restore tissue homeostasis. The success of these strategies requires the isolation of appropriate progenitor cell sources which are straightforward to obtain, display high proliferative potential, and demonstrate an ability to form functional vessels. Several populations are of interest including endothelial colony-forming cells, a subpopulation of endothelial progenitor cells. Additionally, the development of scaffolds to deliver and support progenitor cell survival and function is crucial for the formation of functional vascular networks. The composition and biophysical properties of these scaffolds have been shown to modulate endothelial cell behavior and vessel formation. However, further investigation is needed to better understand how these mechanical properties and biophysical properties impact vessel formation. Additionally, several other cell populations are involved in neoangiogenesis and formation of tissue parenchyma and an understanding of the potential impact of these cell populations on the biophysical properties of scaffolds will also be needed to advance these strategies. This chapter examines how the biophysical properties of matrix scaffolds can influence vessel formation and remodeling and, in particular, the impact on in vivo human endothelial progenitor cell vessel formation.

  20. Changes in rRNA transcription influence proliferation and cell fate within a stem cell lineage.

    PubMed

    Zhang, Qiao; Shalaby, Nevine A; Buszczak, Michael

    2014-01-17

    Ribosome biogenesis drives cell growth and proliferation, but mechanisms that modulate this process within specific lineages remain poorly understood. Here, we identify a Drosophila RNA polymerase I (Pol I) regulatory complex composed of Under-developed (Udd), TAF1B, and a TAF1C-like factor. Disruption of udd or TAF1B results in reduced ovarian germline stem cell (GSC) proliferation. Female GSCs display high levels of ribosomal RNA (rRNA) transcription, and Udd becomes enriched in GSCs relative to their differentiating daughters. Increasing Pol I transcription delays differentiation, whereas reducing rRNA production induces both morphological changes that accompany multicellular cyst formation and specific decreased expression of the bone morphogenetic protein (BMP) pathway component Mad. These findings demonstrate that modulating rRNA synthesis fosters changes in the cell fate, growth, and proliferation of female Drosophila GSCs and their daughters.

  1. Mechanosensitive store-operated calcium entry regulates the formation of cell polarity.

    PubMed

    Huang, Yi-Wei; Chang, Shu-Jing; I-Chen Harn, Hans; Huang, Hui-Ting; Lin, Hsi-Hui; Shen, Meng-Ru; Tang, Ming-Jer; Chiu, Wen-Tai

    2015-09-01

    Ca(2+) -mediated formation of cell polarity is essential for directional migration which plays an important role in physiological and pathological processes in organisms. To examine the critical role of store-operated Ca(2+) entry, which is the major form of extracellular Ca(2+) influx in non-excitable cells, in the formation of cell polarity, we employed human bone osteosarcoma U2OS cells, which exhibit distinct morphological polarity during directional migration. Our analyses showed that Ca(2+) was concentrated at the rear end of cells and that extracellular Ca(2+) influx was important for cell polarization. Inhibition of store-operated Ca(2+) entry using specific inhibitors disrupted the formation of cell polarity in a dose-dependent manner. Moreover, the channelosomal components caveolin-1, TRPC1, and Orai1 were concentrated at the rear end of polarized cells. Knockdown of TRPC1 or a TRPC inhibitor, but not knockdown of Orai1, reduced cell polarization. Furthermore, disruption of lipid rafts or overexpression of caveolin-1 contributed to the downregulation of cell polarity. On the other hand, we also found that cell polarity, store-operated Ca(2+) entry activity, and cell stiffness were markedly decreased by low substrate rigidity, which may be caused by the disorganization of actin filaments and microtubules that occurs while regulating the activity of the mechanosensitive TRPC1 channel.

  2. MBD3 inhibits formation of liver cancer stem cells

    PubMed Central

    Li, Ruizhi; He, Qihua; Han, Shuo; Zhang, Mingzhi; Liu, Jinwen; Su, Ming; Wei, Shiruo; Wang, Xuan; Shen, Li

    2017-01-01

    Liver cancer cells can be reprogrammed into induced cancer stem cells (iCSCs) by exogenous expression of the reprogramming transcription factors Oct4, Sox2, Klf4 and c-Myc (OSKM). The nucleosome remodeling and deacetylase (NuRD) complex is essential for reprogramming somatic cells. In this study, we investigated the function of NuRD in the induction of liver CSCs. We showed that suppression of methyl-CpG binding domain protein 3 (MBD3), a core subunit of the NuRD repressor complex, together with OSKM transduction, induces conversion of liver cancer cells into stem-like cells. Expression of the transcription factor c-JUN is increased in MBD3-depleted iCSCs, and c-JUN activates endogenous pluripotent genes and regulates iCSC-related genes. These results indicate that MBD3/NuRD inhibits the induction of iCSCs, while c-JUN facilitates the generation of CSC-like properties. The iCSC reprogramming approach devised here provides a novel platform for dissection of the disordered signaling in liver CSCs. In addition, our results indicate that c-JUN may serve as a potential target for liver cancer therapy. PMID:27894081

  3. Kinetics of Lipofuscin Formation in Aging Retinal Pigment Epithelium Cells

    NASA Astrophysics Data System (ADS)

    Family, Fereydoon; Mazzitello, K. I.; Arizmendi, C. M.; Grossniklaus, Hans E.

    2010-03-01

    Lipofuscin is a deposit that is formed over time by aggregation and clustering of incompletely degraded membrane material in various types of cells. Lipofuscin is made of free-radical-damaged protein and fat and is known to be present in age- related macular dgeneration (AMD), Alzheimer disease, and Parkinson disease. AMD is the leading cause of blindness in adults. The degradation of retinal pigment epithelium cells (RPE) through accumulation of lipsofuscin is considered a significant pathogenic factor in the development of AMD. We will present the results of a study of the kinetics of lipofuscin growth in RPE cells using Kinetic Monte Carlo simulations and scaling theory on a cluster aggregation model. The model captures the essential physics of lipofuscin growth in the cells. A remarkable feature is that small particles may be removed from the cells while the larger ones become fixed and grow by aggregation. We compare our results with the number of lipofuscin granules in eyes with early age-related degeneration.

  4. Investigation of Contact Formation during Silicon Solar Cell Production

    NASA Astrophysics Data System (ADS)

    Mojrová, Barbora

    2016-05-01

    This article deals with the investigation of the influence of sintering conditions on the formation process of screen printed contacts on passivated boron doped P+ emitters. The experiment was focused on measuring of resistance changes of two thick film pastes during firing processes with different conditions. Two different temperature profiles were compared at an atmospheric concentration of O2. The influence of the O2 concentration on resistance was investigated for one profile. A rapid thermal processing furnace modified for in-situ resistance measurements was used. The change of resistance was measured simultaneously with the temperature.

  5. Application of laser annealing to solar cell junction formation

    NASA Technical Reports Server (NTRS)

    Katzeff, J. S.; Lopez, M.; Josephs, R. H.

    1981-01-01

    The possibility of using high-energy Q-switched Nd:glass lasers to form pn junctions in solar cells by annealing ion-implanted substrates is investigated. The properties of laser annealed cells are analyzed by electrical, transmission electron microscopy, Rutherford backscattering and secondary ion mass spectrometry techniques. Tests indicate the laser annealed substrates to be damage-free and electrically active. Similar reference analysis of ion-implanted furnace-annealed substrates reveals the presence of residual defects in the form of dislocation lines and loops with substantial impurity redistribution evident for some anneal temperature/time regimes. Fabricated laser annealed cells exhibit excellent conversion efficiency. It is noted that additional improvements are anticipated once the anneal parameters for a back surface field are optimized.

  6. Formation and maintenance of the Golgi apparatus in plant cells.

    PubMed

    Ito, Yoko; Uemura, Tomohiro; Nakano, Akihiko

    2014-01-01

    The Golgi apparatus plays essential roles in intracellular trafficking, protein and lipid modification, and polysaccharide synthesis in eukaryotic cells. It is well known for its unique stacked structure, which is conserved among most eukaryotes. However, the mechanisms of biogenesis and maintenance of the structure, which are deeply related to ER-Golgi and intra-Golgi transport systems, have long been mysterious. Now having extremely powerful microscopic technologies developed for live-cell imaging, the plant Golgi apparatus provides an ideal system to resolve the question. The plant Golgi apparatus has unique features that are not conserved in other kingdoms, which will also give new insights into the Golgi functions in plant life. In this review, we will summarize the features of the plant Golgi apparatus and transport mechanisms around it, with a focus on recent advances in Golgi biogenesis by live imaging of plants cells. © 2014 Elsevier Inc. All rights reserved.

  7. Biofilm formation on polystyrene in detached vs. planktonic cells of polyhydroxyalkanoate-accumulating Halomonas venusta.

    PubMed

    Berlanga, Mercedes; Domènech, Òscar; Guerrero, Ricardo

    2014-12-01

    Biofilm development is characterized by distinct stages of initial attachment, microcolony formation and maturation (sessile cells), and final detachment (dispersal of new, planktonic cells). In this work we examined the influence of polyhydroxyalkanoate (PHA) accumulation on bacterial surface properties and biofilm formation on polystyrene in detached vs. planktonic cells of an environmental strain isolated from microbial mats, Halomonas venusta MAT28. This strain was cultured either in an artificial biofilm in which the cells were immobilized on alginate beads (sessile) or as free-swimming (planktonic) cells. For the two modes of growth, conditions allowing or preventing PHA accumulation were established. Cells detached from alginate beads and their planktonic counterparts were used to study cell surface properties and cellular adhesion on polystyrene. Detached cells showed a slightly higher affinity than planktonic cells for chloroform (Lewis-acid) and a greater hydrophobicity (affinity for hexadecane and hexane). Those surface characteristics of the detached cells may explain their better adhesion on polystyrene compared to planktonic cells. Adhesion to polystyrene was not significantly different between H. venusta cells that had accumulated PHA vs. those that did not. These observations suggest that the surface properties of detached cells clearly differ from those of planktonic cells and that for at least the first 48 h after detachment from alginate beads H. venusta retained the capacity of sessile cells to adhere to polystyrene and to form a biofilm. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  8. Rap1 integrates tissue polarity, lumen formation, and tumorigenicpotential in human breast epithelial cells

    SciTech Connect

    Itoh, Masahiko; Nelson, Celeste M.; Myers, Connie A.; Bissell,Mina J.

    2006-09-29

    Maintenance of apico-basal polarity in normal breast epithelial acini requires a balance between cell proliferation, cell death, and proper cell-cell and cell-extracellular matrix signaling. Aberrations in any of these processes can disrupt tissue architecture and initiate tumor formation. Here we show that the small GTPase Rap1 is a crucial element in organizing acinar structure and inducing lumen formation. Rap1 activity in malignant HMT-3522 T4-2 cells is appreciably higher than in S1 cells, their non-malignant counterparts. Expression of dominant-negative Rap1 resulted in phenotypic reversion of T4-2 cells, led to formation of acinar structures with correct apico-basal polarity, and dramatically reduced tumor incidence despite the persistence of genomic abnormalities. The resulting acini contained prominent central lumina not observed when other reverting agents were used. Conversely, expression of dominant-active Rap1 in T4-2 cells inhibited phenotypic reversion and led to increased invasiveness and tumorigenicity. Thus, Rap1 acts as a central regulator of breast architecture, with normal levels of activation instructing apical polarity during acinar morphogenesis, and increased activation inducing tumor formation and progression to malignancy.

  9. Inhibition of macrophage-derived foam cell formation by ezetimibe via the caveolin-1/MAPK pathway.

    PubMed

    Qin, Li; Yang, Yun-Bo; Yang, Yi-Xin; Zhu, Neng; Liu, Zheng; Ni, Ya-Guang; Li, Shun-Xiang; Zheng, Xi-Long; Liao, Duan-Fang

    2016-02-01

    Ezetimibe, a selective inhibitor of intestinal cholesterol absorption, effectively reduces plasma cholesterol, but its effect on atherosclerosis is unclear. Foam cell formation has been implicated as a key mediator during the development of atherosclerosis. The purpose of this study was to investigate the effects of ezetimibe on foam cell formation and explore the underlying mechanism. The results presented here show that ezetimibe reduces atherosclerotic lesions in apolipoprotein E deficient (apoE-/-) mice by lowering cholesterol levels. Treatment of macrophages with Chol:MβCD resulted in foam cell formation, which was concentration-dependently inhibited by the presence of ezetimibe. Mechanically, ezetimibe treatment downregulated the expression of CD36 and scavenger receptor class B1 (SR-B1), but upregulated the expression of apoE and caveolin-1 in macrophage-derived foam cells, which kept consistent with our microarray results. Moreover, treatment with ezetimibe abrogated the increase of phospho-extracellular signal regulated kinase (ERK) 1/2 and their nuclear accumulation in foam cells. Inhibition of the MAPK pathway by the MEK inhibitor PD98059 attenuated the inhibitory effect of ezetimibe on the expression of p-ERK1/2 and caveolin-1. Taken together, these results showed that ezetimibe suppressed foam cell formation via the caveolin-1/MAPK signalling pathway, suggesting that inhibition of foam cell formation might be a novel mechanism underlying the anti-atherosclerotic effect of ezetimibe.

  10. The effect of size on dislocation cell formation and strain hardening in aluminium

    NASA Astrophysics Data System (ADS)

    Yu, Qian; Mishra, Raja K.; Morris, John W.; Minor, Andrew M.

    2014-06-01

    The formation of dislocation cells has a significant impact on the strain hardening behaviour of metals. Dislocation cells can form in metals with a characteristic size defined by three-dimensional tangles of dislocations that serve as "walls" and less dense internal regions. It has been proposed that inhibiting the formation of dislocation cells could improve the strain hardening behaviour of metals such as Al. Here we employ in situ scanning electron microscope compression testing of pure Al single crystal pillars with physical dimensions larger, close to and smaller than the reported cell size in Al, respectively, to investigate the possible size effect on the formation of dislocation cell and the consequent change of mechanical properties. We observed that the formation of dislocation cells is inhibited as the pillar size decreases to a critical value and simultaneously both the strength and the strain hardening behaviour become strongly enhanced. This phenomenon is discussed in terms of the effect of dimensional restriction on the formation of dislocation cells. The reported mechanism could be applied in polycrystalline Al where the tunable physical dimension could be grain size instead of sample size, providing insight into Al alloy design.

  11. Pattern formation of Rho GTPases in single cell wound healing

    PubMed Central

    Simon, Cory M.; Vaughan, Emily M.; Bement, William M.; Edelstein-Keshet, Leah

    2013-01-01

    The Rho GTPases—Rho, Rac, and Cdc42—control an enormous variety of processes, many of which reflect activation of these GTPases in spatially confined and mutually exclusive zones. By using mathematical models and experimental results to establish model parameters, we analyze the formation and segregation of Rho and Cdc42 zones during Xenopus oocyte wound repair and the role played by Abr, a dual guanine nucleotide exchange factor–GTPase-activating protein, in this process. The Rho and Cdc42 zones are found to be best represented as manifestations of spatially modulated bistability, and local positive feedback between Abr and Rho can account for the maintenance and dynamic properties of the Rho zone. In contrast, the invocation of an Abr-independent positive feedback loop is required to account for Cdc42 spatial bistability. In addition, the model replicates the results of previous in vivo experiments in which Abr activity is manipulated. Further, simulating the model with two closely spaced wounds made nonintuitive predictions about the Rho and Cdc42 patterns; these predictions were confirmed by experiment. We conclude that the model is a useful tool for analysis of Rho GTPase signaling and that the Rho GTPases can be fruitfully considered as components of intracellular pattern formation systems. PMID:23264464

  12. High-Throughput Single-Cell Derived Sphere Formation for Cancer Stem-Like Cell Identification and Analysis

    PubMed Central

    Chen, Yu-Chih; Ingram, Patrick N.; Fouladdel, Shamileh; McDermott, Sean P.; Azizi, Ebrahim; Wicha, Max S.; Yoon, Euisik

    2016-01-01

    Considerable evidence suggests that many malignancies are driven by a cellular compartment that displays stem cell properties. Cancer stem-like cells (CSCs) can be identified by expression of cell surface markers or enzymatic activity, but these methods are limited by phenotypic heterogeneity and plasticity of CSCs. An alternative phenotypic methodology based on in-vitro sphere formation has been developed, but it is typically labor-intensive and low-throughput. In this work, we present a 1,024-microchamber microfluidic platform for single-cell derived sphere formation. Utilizing a hydrodynamic capturing scheme, more than 70% of the microchambers capture only one cell, allowing for monitoring of sphere formation from heterogeneous cancer cell populations for identification of CSCs. Single-cell derived spheres can be retrieved and dissociated for single-cell analysis using a custom 96-gene panel to probe heterogeneity within the clonal CSC spheres. This microfluidic platform provides reliable and high-throughput sphere formation for CSC identification and downstream clonal analysis. PMID:27292795

  13. High-Throughput Single-Cell Derived Sphere Formation for Cancer Stem-Like Cell Identification and Analysis

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Chih; Ingram, Patrick N.; Fouladdel, Shamileh; McDermott, Sean P.; Azizi, Ebrahim; Wicha, Max S.; Yoon, Euisik

    2016-06-01

    Considerable evidence suggests that many malignancies are driven by a cellular compartment that displays stem cell properties. Cancer stem-like cells (CSCs) can be identified by expression of cell surface markers or enzymatic activity, but these methods are limited by phenotypic heterogeneity and plasticity of CSCs. An alternative phenotypic methodology based on in-vitro sphere formation has been developed, but it is typically labor-intensive and low-throughput. In this work, we present a 1,024-microchamber microfluidic platform for single-cell derived sphere formation. Utilizing a hydrodynamic capturing scheme, more than 70% of the microchambers capture only one cell, allowing for monitoring of sphere formation from heterogeneous cancer cell populations for identification of CSCs. Single-cell derived spheres can be retrieved and dissociated for single-cell analysis using a custom 96-gene panel to probe heterogeneity within the clonal CSC spheres. This microfluidic platform provides reliable and high-throughput sphere formation for CSC identification and downstream clonal analysis.

  14. Mother-daughter dyadic approach for starting preconception counseling at puberty in girls with diabetes.

    PubMed

    Charron-Prochownik, Denise; Fischl, Andrea Rodgers; Choi, Jessica; Schmitt, Patricia L; White, Neil H; Becker, Dorothy; Downs, Julie; Hannan, Margaret; Thurheimer, Jennifer; Sereika, Susan M

    2014-12-29

    Preconception counseling (PC) significantly and inexpensively reduces risks of reproductive-health complications for women with diabetes. Our validated technology-based preconception counseling intervention, READY-Girls, is tailored for female teens with type 1 (T1D) and type 2 (T2D) diabetes and targets decision-making regarding effective family planning and seeking PC. Our teen-focused research was instrumental in changing the American Diabetes Association's Practice Recommendations to specify that preconception counseling should "Start at puberty…". This directive requires support from well-informed mothers of teens. Our goal is to provide both teen girls and their mothers with preconception counseling knowledge, and provide mothers with sex-communication training. Evaluation should focus on mother-daughter dyads. This feasibility study explored mother's and daughter's awareness and knowledge of diabetes and pregnancy, and preconception counseling; and compared mother-daughter responses using dyadic analyses. A mixed-method design was conducted with 10 mothers of daughters with T1D. Mothers were given READY-Girls intervention and completed knowledge and support questionnaires. Their responses were compared to those of their daughter's who were participating in a large randomized, control intervention trial with READY-Girls. The major theme from one-on-one interviews was, "I know nothing about diabetes/pregnancy risks and PC". Mother's and daughter's perceptions of having limited knowledge were confirmed by low knowledge scores. Mothers perceived giving higher levels of support compared to their daughter's perceptions of receiving support. Mothers can play a vital role in initiating discussions regarding reproductive-health with their daughters and reinforcing preconception counseling. Mother-daughter team approach for starting preconception counseling at puberty in girls with diabetes is feasible. Mother-daughter dyadic analyses can be important to explore

  15. PROX1 Promotes Secretory Granule Formation in Medullary Thyroid Cancer Cells.

    PubMed

    Ishii, Jun; Yazawa, Takuya; Chiba, Tomohiro; Shishido-Hara, Yukiko; Arimasu, Yuu; Sato, Hanako; Kamma, Hiroshi

    2016-03-01

    Mechanisms of endocrine secretory granule (SG) formation in thyroid C cells and medullary thyroid cancer (MTC) cells have not been fully elucidated. Here we directly demonstrated that PROX1, a developmental homeobox gene, is transcriptionally involved in SG formation in MTC, which is derived from C cells. Analyses using gene expression databases on web sites revealed that, among thyroid cancer cells, MTC cells specifically and highly express PROX1 as well as several SG-forming molecule genes. Immunohistochemical analyses showed that in vivo MTC and C cells expressed PROX1, although follicular thyroid cancer and papillary thyroid cancer cells, normal follicular cells did not. Knockdown of PROX1 in an MTC cells reduced SGs detected by electron microscopy, and decreased expression of SG-related genes (chromogranin A, chromogranin B, secretogranin II, secretogranin III, synaptophysin, and carboxypeptidase E). Conversely, the introduction of a PROX1 transgene into a papillary thyroid cancer and anaplastic thyroid cancer cells induced the expression of SG-related genes. Reporter assays using the promoter sequence of chromogranin A showed that PROX1 activates the chromogranin A gene in addition to the known regulatory mechanisms, which are mediated via the cAMP response element binding protein and the repressor element 1-silencing transcription factor. Furthermore, chromatin immunoprecipitation-PCR assays demonstrated that PROX1 binds to the transcriptional regulatory element of the chromogranin A gene. In conclusion, PROX1 is an important regulator of endocrine SG formation in MTC cells.

  16. Predictors of perceived benefits and drawbacks of using paid service among daughter and daughter-in-law caregivers of people with dementia.

    PubMed

    Moon, Heehyul

    2016-01-01

    This study examines the types of benefits and drawbacks of a sample of daughter and daughter-in-law caregivers (CG) of people with dementia and explores the predictors associated with the identified benefits and drawbacks. The current study used a secondary analysis of a purposive sample of 102 daughters or daughters-in-law living in Northeast Ohio who were required to be using at least 8 hours of paid services per week to help in caring for their care recipient (CR) with Alzheimer's disease or other memory problems. Logistic regression was used. All respondents answered that there were benefits of having the paid help, but 51% of them reported drawbacks as well. The analyses revealed that predictors of each identified benefit and drawback were different. Information about benefits and drawbacks of paid help is useful for service providers to design better services for CGs of people with dementia.

  17. Down-regulation of MUC1 in cancer cells inhibits cell migration by promoting E-cadherin/catenin complex formation

    SciTech Connect

    Yuan Zhenglong; Wong, Sandy; Borrelli, Alexander; Chung, Maureen A.

    2007-10-26

    MUC1, a tumor associated glycoprotein, is over-expressed in most cancers and can promote proliferation and metastasis. The objective of this research was to study the role of MUC1 in cancer metastasis and its potential mechanism. Pancreatic (PANC1) and breast (MCF-7) cancer cells with stable 'knockdown' of MUC1 expression were created using RNA interference. {beta}-Catenin and E-cadherin protein expression were upregulated in PANC1 and MCF-7 cells with decreased MUC1 expression. Downregulation of MUC1 expression also induced {beta}-catenin relocation from the nucleus to the cytoplasm, increased E-cadherin/{beta}-catenin complex formation and E-cadherin membrane localization in PANC1 cells. PANC1 cells with 'knockdown' MUC1 expression had decreased in vitro cell invasion. This study suggested that MUC1 may affect cancer cell migration by increasing E-cadherin/{beta}-catenin complex formation and restoring E-cadherin membrane localization.

  18. Down-regulation of MUC1 in cancer cells inhibits cell migration by promoting E-cadherin/catenin complex formation.

    PubMed

    Yuan, Zhenglong; Wong, Sandy; Borrelli, Alexander; Chung, Maureen A

    2007-10-26

    MUC1, a tumor associated glycoprotein, is over-expressed in most cancers and can promote proliferation and metastasis. The objective of this research was to study the role of MUC1 in cancer metastasis and its potential mechanism. Pancreatic (PANC1) and breast (MCF-7) cancer cells with stable 'knockdown' of MUC1 expression were created using RNA interference. beta-Catenin and E-cadherin protein expression were upregulated in PANC1 and MCF-7 cells with decreased MUC1 expression. Downregulation of MUC1 expression also induced beta-catenin relocation from the nucleus to the cytoplasm, increased E-cadherin/beta-catenin complex formation and E-cadherin membrane localization in PANC1 cells. PANC1 cells with 'knockdown' MUC1 expression had decreased in vitro cell invasion. This study suggested that MUC1 may affect cancer cell migration by increasing E-cadherin/beta-catenin complex formation and restoring E-cadherin membrane localization.

  19. Bone Niches, Hematopoietic Stem Cells, and Vessel Formation

    PubMed Central

    Tamma, Roberto; Ribatti, Domenico

    2017-01-01

    Bone marrow (BM) is a source of hematopoietic stem cells (HSCs). HSCs are localized in both the endosteum, in the so-called endosteal niche, and close to thin-walled and fenestrated sinusoidal vessel in the center of BM, in the so-called vascular niche. HSCs give rise to all types of mature blood cells through a process finely controlled by numerous signals emerging from the bone marrow niches where HSCs reside. This review will focus on the description of the role of BM niches in the control of the fate of HSCs and will also highlight the role of the BM niches in the regulation of vasculogenesis and angiogenesis. Moreover, alterations of the signals in niche microenvironment are involved in many aspects of tumor progression and vascularization and further knowledge could provide the basis for the development of new therapeutic strategies. PMID:28098778

  20. DISTRIBUTION OF RADIOACTIVITY IN AUTOLYZED CELL WALL OF BACILLUS CEREUS DURING SPHEROPLAST FORMATION1

    PubMed Central

    Kronish, Donald P.; Mohan, Raam R.; Schwartz, Benjamin S.

    1964-01-01

    Kronish, Donald P. (Warner-Lambert Research Institute, Morris Plains, N.J.), Raam R. Mohan, and Benjamin S. Schwartz. Distribution of radioactivity in autolyzed cell wall of Bacillus cereus during spheroplast formation. J. Bacteriol. 87:581–587. 1964.—Spheroplasts of Bacillus cereus strain T were produced from cells grown in the presence of uniformly labeled C14-glucose. At regular intervals during spheroplast formation, enzymatically degraded cell wall was isolated by a new procedure. Radioactivity of solubilized cell wall in cell-free material increased from 2.5 to 42% of the total incorporated label during spheroplast formation. The rate of cell-wall degradation as measured by increase in radioactivity was biphasic with relative slopes of 2.0 and 5.0. During autolytic depolymerization of B. cereus cell wall, two major components were solubilized at different rates. Chemical fractionation revealed these to be a peptide and a mucopeptide. The possibility of two enzymes being involved in spheroplast formation and cell-wall degradation is discussed. Images PMID:14127573

  1. Study of budding yeast colony formation and its characterizations by using circular granular cell

    NASA Astrophysics Data System (ADS)

    Aprianti, D.; Haryanto, F.; Purqon, A.; Khotimah, S. N.; Viridi, S.

    2016-03-01

    Budding yeast can exhibit colony formation in solid substrate. The colony of pathogenic budding yeast can colonize various surfaces of the human body and medical devices. Furthermore, it can form biofilm that resists drug effective therapy. The formation of the colony is affected by the interaction between cells and with its growth media. The cell budding pattern holds an important role in colony expansion. To study this colony growth, the molecular dynamic method was chosen to simulate the interaction between budding yeast cells. Every cell was modelled by circular granular cells, which can grow and produce buds. Cohesion force, contact force, and Stokes force govern this model to mimic the interaction between cells and with the growth substrate. Characterization was determined by the maximum (L max) and minimum (L min) distances between two cells within the colony and whether two lines that connect the two cells in the maximum and minimum distances intersect each other. Therefore, it can be recognized the colony shape in circular, oval, and irregular shapes. Simulation resulted that colony formation are mostly in oval shape with little branch. It also shows that greater cohesion strength obtains more compact colony formation.

  2. Formation of tetrahydrocurcumin by reduction of curcumin with cultured plant cells of Marchantia polymorpha.

    PubMed

    Shimoda, Kei; Kubota, Naoji; Hirano, Hirotaka; Matsumoto, Masahiro; Hamada, Hatsuyuki; Hamada, Hiroki

    2012-04-01

    Cultured plant cells of Marchantia polymorpha, Nicotiana tabacum, Phytolacca americana, Catharanthus roseus, and Gossypium hirsutum were examined for their ability to reduce curcumin. Only M. polymorpha cells converted curcumin into tetrahydrocurcumin in 90% yield in one day. Time-course experiment revealed a two-step formation of tetrahydrocurcumin via dihydrocurcumin.

  3. Arabidopsis R-SNARE Proteins VAMP721 and VAMP722 Are Required for Cell Plate Formation

    PubMed Central

    Liu, Peng; Hao, Huaiqing; Jin, Jing Bo; Lin, Jinxing

    2011-01-01

    Background Cell plate formation during plant cytokinesis is facilitated by SNARE complex-mediated vesicle fusion at the cell-division plane. However, our knowledge regarding R-SNARE components of membrane fusion machinery for cell plate formation remains quite limited. Methodology/Principal Findings We report the in vivo function of Arabidopsis VAMP721 and VAMP722, two closely sequence-related R-SNAREs, in cell plate formation. Double homozygous vamp721vamp722 mutant seedlings showed lethal dwarf phenotypes and were characterized by rudimentary roots, cotyledons and hypocotyls. Furthermore, cell wall stubs and incomplete cytokinesis were frequently observed in vamp721vamp722 seedlings. Confocal images revealed that green fluorescent protein-tagged VAMP721 and VAMP722 were preferentially localized to the expanding cell plates in dividing cells. Drug treatments and co-localization analyses demonstrated that punctuate organelles labeled with VAMP721 and VAMP722 represented early endosomes overlapped with VHA-a1-labeled TGN, which were distinct from Golgi stacks and prevacuolar compartments. In addition, protein traffic to the plasma membrane, but not to the vacuole, was severely disrupted in vamp721vamp722 seedlings by subcellular localization of marker proteins. Conclusion/Significance These observations suggest that VAMP721 and VAMP722 are involved in secretory trafficking to the plasma membrane via TGN/early endosomal compartment, which contributes substantially to cell plate formation during plant cytokinesis. PMID:22022536

  4. Formation of newly synthesized adeno-associated virus capsids in the cell nucleus.

    PubMed

    Bell, Peter; Vandenberghe, Luk H; Wilson, James M

    2014-06-01

    Adeno-associated virus (AAV) particles inside the nucleus of a HEK 293 cell are shown by electron microscopy. Cells have been triple-transfected for vector production and were analyzed for capsid formation three days later. Newly assembled particle are visible as seemingly unstructured conglomerates or crystal-like arrays.

  5. Daughters at Risk of Female Genital Mutilation: Examining the Determinants of Mothers' Intentions to Allow Their Daughters to Undergo Female Genital Mutilation.

    PubMed

    Pashaei, Tahereh; Ponnet, Koen; Moeeni, Maryam; Khazaee-pool, Maryam; Majlessi, Fereshteh

    2016-01-01

    Female genital mutilation (FGM) is still a common practice in many countries in Africa and the Middle East. Understanding the determinants of FGM can lead to more active interventions to prevent this harmful practice. The goal of this study is to explore factors associated with FGM behavior among Iranian mothers and their daughters. Based on Ajzen's theory of planned behavior, we examined the predictive value of attitudes, subjective norms, perceived behavioral control and several socio-demographic variables in relation to mothers' intentions to mutilate their daughters. A paper-and-pencil survey was conducted among 300 mothers (mean age = 33.20, SD = 9.09) who had at least one daughter and who lived in Ravansar, a county in Kermanshah Province in Iran. Structural equation modeling was used to investigate the relationships among the study variables. Our results indicate that attitude is the strongest predictor of mothers' intentions to allow their daughters to undergo FGM, followed by subjective norms. Compared to younger mothers, older mothers have more positive attitudes toward FGM, perceive themselves as having more control over their behavior and demonstrate a greater intention to allow their daughter to undergo FGM. Furthermore, we found that less educated mothers and mothers living in rural areas had more positive attitudes toward FGM and feel more social pressure to allow FGM. The model accounts for 93 percent of the variance in the mothers' intentions to allow their daughters to undergo FGM. Intervention programs that want to decrease FGM might focus primarily on converting mothers' neutral or positive feelings toward FGM into negative attitudes and on alleviating the perceived social pressure to mutilate one's daughter. Based on our findings, we provide recommendations about how to curtail mothers' intentions to allow their daughters to undergo FGM.

  6. Daughters at Risk of Female Genital Mutilation: Examining the Determinants of Mothers’ Intentions to Allow Their Daughters to Undergo Female Genital Mutilation

    PubMed Central

    Pashaei, Tahereh; Ponnet, Koen; Moeeni, Maryam; Khazaee-pool, Maryam; Majlessi, Fereshteh

    2016-01-01

    Female genital mutilation (FGM) is still a common practice in many countries in Africa and the Middle East. Understanding the determinants of FGM can lead to more active interventions to prevent this harmful practice. The goal of this study is to explore factors associated with FGM behavior among Iranian mothers and their daughters. Based on Ajzen’s theory of planned behavior, we examined the predictive value of attitudes, subjective norms, perceived behavioral control and several socio-demographic variables in relation to mothers’ intentions to mutilate their daughters. A paper-and-pencil survey was conducted among 300 mothers (mean age = 33.20, SD = 9.09) who had at least one daughter and who lived in Ravansar, a county in Kermanshah Province in Iran. Structural equation modeling was used to investigate the relationships among the study variables. Our results indicate that attitude is the strongest predictor of mothers’ intentions to allow their daughters to undergo FGM, followed by subjective norms. Compared to younger mothers, older mothers have more positive attitudes toward FGM, perceive themselves as having more control over their behavior and demonstrate a greater intention to allow their daughter to undergo FGM. Furthermore, we found that less educated mothers and mothers living in rural areas had more positive attitudes toward FGM and feel more social pressure to allow FGM. The model accounts for 93 percent of the variance in the mothers’ intentions to allow their daughters to undergo FGM. Intervention programs that want to decrease FGM might focus primarily on converting mothers’ neutral or positive feelings toward FGM into negative attitudes and on alleviating the perceived social pressure to mutilate one’s daughter. Based on our findings, we provide recommendations about how to curtail mothers’ intentions to allow their daughters to undergo FGM. PMID:27031613

  7. Biofilm formation and antibiotic susceptibility in dispersed cells versus planktonic cells from clinical, industry and environmental origins.

    PubMed

    Berlanga, Mercedes; Gomez-Perez, Laura; Guerrero, Ricardo

    2017-08-02

    We examined the cell-surface physicochemical properties, the biofilm formation capability and the antibiotic susceptibility in dispersed cells (from an artificial biofilm of alginate beads) and compared with their planktonic (free-swimming) counterparts. The strains used were from different origins, such as clinical (Acinetobacter baumannii AB4), cosmetic industry (Klebsiella oxytoca EU213, Pseudomonas aeruginosa EU190), and environmental (Halomonas venusta MAT28). In general, dispersed cells adhered better to surfaces (measured as the "biofilm index") and had a greater hydrophobicity [measured as the microbial affinity to solvents (MATS)] than planktonic cells. The susceptibility to two antibiotics (ciprofloxacin and tetracycline) of dispersed cells was higher compared with that of their planktonic counterparts (tested by the "bactericidal index"). Dispersed and planktonic cells exhibited differences in cell permeability, especially in efflux pump activity, which could be related to the differences observed in susceptibility to antibiotics. At 1 h of biofilm formation in microtiter plates, dispersed cells treated with therapeutic concentration of ciprofloxacin yielded a lower biofilm index than the control dispersed cells without ciprofloxacin. With respect to the planktonic cells, the biofilm index was similar with and without the ciprofloxacin treatment. In both cases there were a reduction of the number of bacteria measured as viable count of the supernatant. The lower biofilm formation in dispersed cells with ciprofloxacin treatment may be due to a significant increase of biofilm disruption with respect to the biofilm from planktonic cells. From a clinical point of view, biofilms formed on medical devices such as catheters, cells that can be related to an infection were the dispersed cells. Our results showed that early treatment with ciprofloxacin of dispersed cells could diminishe bacterial dispersion and facilitate the partial elimination of the new

  8. Dscam-Mediated Cell Recognition Regulates Neural Circuit Formation

    PubMed Central

    Hattori, Daisuke; Millard, S. Sean; Wojtowicz, Woj M.; Zipursky, S. Lawrence

    2009-01-01

    The Dscam family of immunoglobulin cell surface proteins mediates recognition events between neurons that play an essential role in the establishment of neural circuits. The Drosophila Dscam1 locus encodes tens of thousands of cell surface proteins via alternative splicing. These isoforms exhibit exquisite isoform-specific binding in vitro that mediates homophilic repulsion in vivo. These properties provide the molecular basis for self-avoidance, an essential developmental mechanism that allows axonal and dendritic processes to uniformly cover their synaptic fields. In a mechanistically similar fashion, homophilic repulsion mediated by Drosophila Dscam2 prevents processes from the same class of cells from occupying overlapping synaptic fields through a process called tiling. Genetic studies in the mouse visual system support the view that vertebrate DSCAM also promotes both self-avoidance and tiling. By contrast, DSCAM and DSCAM-L promote layer-specific targeting in the chick visual system, presumably through promoting homophilic adhesion. The fly and mouse studies underscore the importance of homophilic repulsion in regulating neural circuit assembly, whereas the chick studies suggest that DSCA Mproteins may mediate a variety of different recognition events during wiring in a context-dependent fashion. PMID:18837673

  9. Oligomer formation of tau protein hyperphosphorylated in cells.

    PubMed

    Tepper, Katharina; Biernat, Jacek; Kumar, Satish; Wegmann, Susanne; Timm, Thomas; Hübschmann, Sabrina; Redecke, Lars; Mandelkow, Eva-Maria; Müller, Daniel J; Mandelkow, Eckhard

    2014-12-05

    Abnormal phosphorylation ("hyperphosphorylation") and aggregation of Tau protein are hallmarks of Alzheimer disease and other tauopathies, but their causative connection is still a matter of debate. Tau with Alzheimer-like phosphorylation is also present in hibernating animals, mitosis, or during embryonic development, without leading to pathophysiology or neurodegeneration. Thus, the role of phosphorylation and the distinction between physiological and pathological phosphorylation needs to be further refined. So far, the systematic investigation of highly phosphorylated Tau was difficult because a reliable method of preparing reproducible quantities was not available. Here, we generated full-length Tau (2N4R) in Sf9 cells in a well defined phosphorylation state containing up to ∼20 phosphates as judged by mass spectrometry and Western blotting with phospho-specific antibodies. Despite the high concentration in living Sf9 cells (estimated ∼230 μm) and high phosphorylation, the protein was not aggregated. However, after purification, the highly phosphorylated protein readily formed oligomers, whereas fibrils were observed only rarely. Exposure of mature primary neuronal cultures to oligomeric phospho-Tau caused reduction of spine density on dendrites but did not change the overall cell viability. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Oligomer Formation of Tau Protein Hyperphosphorylated in Cells*

    PubMed Central

    Tepper, Katharina; Biernat, Jacek; Kumar, Satish; Wegmann, Susanne; Timm, Thomas; Hübschmann, Sabrina; Redecke, Lars; Mandelkow, Eva-Maria; Müller, Daniel J.; Mandelkow, Eckhard

    2014-01-01

    Abnormal phosphorylation (“hyperphosphorylation”) and aggregation of Tau protein are hallmarks of Alzheimer disease and other tauopathies, but their causative connection is still a matter of debate. Tau with Alzheimer-like phosphorylation is also present in hibernating animals, mitosis, or during embryonic development, without leading to pathophysiology or neurodegeneration. Thus, the role of phosphorylation and the distinction between physiological and pathological phosphorylation needs to be further refined. So far, the systematic investigation of highly phosphorylated Tau was difficult because a reliable method of preparing reproducible quantities was not available. Here, we generated full-length Tau (2N4R) in Sf9 cells in a well defined phosphorylation state containing up to ∼20 phosphates as judged by mass spectrometry and Western blotting with phospho-specific antibodies. Despite the high concentration in living Sf9 cells (estimated ∼230 μm) and high phosphorylation, the protein was not aggregated. However, after purification, the highly phosphorylated protein readily formed oligomers, whereas fibrils were observed only rarely. Exposure of mature primary neuronal cultures to oligomeric phospho-Tau caused reduction of spine density on dendrites but did not change the overall cell viability. PMID:25339173

  11. Lipid body formation during maturation of human mast cells.

    PubMed

    Dichlberger, Andrea; Schlager, Stefanie; Lappalainen, Jani; Käkelä, Reijo; Hattula, Katarina; Butcher, Sarah J; Schneider, Wolfgang J; Kovanen, Petri T

    2011-12-01

    Lipid droplets, also called lipid bodies (LB) in inflammatory cells, are important cytoplasmic organelles. However, little is known about the molecular characteristics and functions of LBs in human mast cells (MC). Here, we have analyzed the genesis and components of LBs during differentiation of human peripheral blood-derived CD34(+) progenitors into connective tissue-type MCs. In our serum-free culture system, the maturing MCs, derived from 18 different donors, invariably developed triacylglycerol (TG)-rich LBs. Not known heretofore, the MCs transcribe the genes for perilipins (PLIN)1-4, but not PLIN5, and PLIN2 and PLIN3 display different degrees of LB association. Upon MC activation and ensuing degranulation, the LBs were not cosecreted with the cytoplasmic secretory granules. Exogenous arachidonic acid (AA) enhanced LB genesis in Triacsin C-sensitive fashion, and it was found to be preferentially incorporated into the TGs of LBs. The large TG-associated pool of AA in LBs likely is a major precursor for eicosanoid production by MCs. In summary, we demonstrate that cultured human MCs derived from CD34(+) progenitors in peripheral blood provide a new tool to study regulatory mechanisms involving LB functions, with particular emphasis on AA metabolism, eicosanoid biosynthesis, and subsequent release of proinflammatory lipid mediators from these cells.

  12. Role of microRNA-21 in the formation of insulin-producing cells from pancreatic progenitor cells.

    PubMed

    Bai, Chunyu; Li, Xiangchen; Gao, Yuhua; Wang, Kunfu; Fan, Yanan; Zhang, Shuang; Ma, Yuehui; Guan, Weijun

    2016-02-01

    MicroRNAs (miRNAs) regulate insulin secretion, pancreas development, and beta cell differentiation. In this study, to screen for miRNAs and their targets that function during insulin-producing cells (IPCs) formation, we examined the messenger RNA and microRNA expression profiles of pancreatic progenitor cells (PPCs) and IPCs using microarray and deep sequencing approaches, respectively. Combining our data with that from previous reports, we found that miR-21 and its targets play an important role in the formation of IPCs. However, the function of miR-21 in the formation of IPCs from PPCs is poorly understood. Therefore, we over-expressed or inhibited miR-21 and expressed small interfering RNAs of miR-21 targets in PPCs to investigate their functions in IPCs formation. We found that miR-21 acts as a bidirectional switch in the formation of IPCs by regulating the expression of target and downstream genes (SOX6, RPBJ and HES1). Small interfering RNAs were used to knock down these genes in PPCs to investigate their effects on IPCs formation. Single expression of si-RBPJ, si-SOX6 and si-HES1 in PPCs showed that si-RBPJ was an inhibitor, and that si-SOX6 and si-HES1 were promoters of IPCs formation, although si-HES1 induced formation of IPCs at higher rates than si-SOX6. These results suggest that endogenous miRNAs involved in the formation of IPCs from PPCs should be considered in the development of an effective cell transplant therapy for diabetes.

  13. Bone formation in vitro and in nude mice by human osteosarcoma cells.

    PubMed

    Ogose, A; Motoyama, T; Hotta, T; Watanabe, H; Takahashi, H E

    1995-01-01

    Osteosarcomas contain variable amounts of bony tissue, but the mechanism of bone formation by osteosarcoma is not well understood. While a number of cultured human osteosarcoma cell lines have been established, they are maintained by different media and differ qualitatively with regard to bone formation. We examined different media for their ability to support bone formation in vitro and found the alpha-modification of Eagle's minimal essential medium supplemented with beta glycerophosphate was best for this purpose, because it contained the proper calcium and phosphate concentrations. Subsequently, we compared seven human osteosarcoma cell lines under the same experimental conditions to clarify their ability to induce bone formation. NOS-1 cells most frequently exhibited features of bone formation in vitro and in nude mice. Collagen synthesis by tumour cells themselves seemed to be the most important factor for bone volume. However, even HuO9 cells, which lacked collagen synthesis and failed to form bone in vitro, successfully formed tumours containing bone in nude mice. Histological analysis of HuO9 cells in diffusion chambers implanted in nude mice and the findings of polymerase chain reaction indicated that the phenomenon was probably due to bone morphogenetic protein.

  14. Oxygen-consuming chlor alkali cell configured to minimize peroxide formation

    DOEpatents

    Chlistunoff, Jerzy B.; Lipp, Ludwig; Gottesfeld, Shimshon

    2006-08-01

    Oxygen-consuming zero gap chlor-alkali cell was configured to minimize peroxide formation. The cell included an ion-exchange membrane that divided the cell into an anode chamber including an anode and a cathode chamber including an oxygen gas diffusion cathode. The cathode included a single-piece of electrically conducting graphitized carbon cloth. Catalyst and polytetrafluoroethylene were attached to only one side of the cloth. When the cathode was positioned against the cation exchange membrane with the catalyst side away from the membrane, electrolysis of sodium chloride to chlorine and caustic (sodium hydroxide) proceeded with minimal peroxide formation.

  15. Reduction of radon daughter concentrations in structures. [UMTRA project

    SciTech Connect

    Not Available

    1982-12-01

    A structure was identified in Salt Lake City wherein uranium mill tailings had been used in the construction and where unusually high levels of radon daughter concentrations (RDC's) existed. The physical and radiological characteristics of the structure were assessed. Ventilation techniques were investigated to assess their effectiveness in reducing RDC's. A preferred set of equipment was identified, installed in the structure and operated to reduce RDC's. Parametric studies were conducted to determine if supplying fresh air or recirculating air through electrostatic precipitators is more effective in reducing RDC's. Fresh air was found to be more effective in reducing RDC's. RDC's have been reduced to levels at or near the target of 0.03 working level under optimal ventilation conditions. Natural gas consumption with the new equipment is about 39% higher than with the original equipment. Electrical energy usage and electrical demand are respectively 50 and 44% higher with the new equipment than with the original equipment. 16 refs., 14 figs., 8 tabs.

  16. Removal of 222Rn daughters from metal surfaces

    NASA Astrophysics Data System (ADS)

    Zuzel, G.; Wojcik, M.; Majorovits, B.; Lampert, M. O.; Wendling, P.

    2015-08-01

    Removal of the long-lived 222Rn daughters (210Pb, 210Bi and 210Po) from copper, stainless steel and germanium surfaces was investigated. As cleaning techniques etching and electro-polishing was applied to samples in a form of discs exposed earlier to a strong radon source. Reduction of the 210Pb activity was tested using a HPGe spectrometer, for 210Bi a beta spectrometer and for 210Po an alpha spectrometer was used. According to the conducted measurements electro-polishing was always more efficient compared to etching and in case of copper the activity reduction factors for 210Pb, 210Bi and 210Po were between 200 and 400. Etching does not remove 210Po from copper but works very efficiently from germanium. Results obtained for 210Pb and 210Bi for etched stainless steel were worse but still slightly better than those achieved for copper.

  17. Removal of {sup 222}Rn daughters from metal surfaces

    SciTech Connect

    Zuzel, G.; Wojcik, M.; Majorovits, B.; Lampert, M. O.; Wendling, P.

    2015-08-17

    Removal of the long-lived {sup 222}Rn daughters ({sup 210}Pb, {sup 210}Bi and {sup 210}Po) from copper, stainless steel and germanium surfaces was investigated. As cleaning techniques etching and electro-polishing was applied to samples in a form of discs exposed earlier to a strong radon source. Reduction of the {sup 210}Pb activity was tested using a HPGe spectrometer, for {sup 210}Bi a beta spectrometer and for {sup 210}Po an alpha spectrometer was used. According to the conducted measurements electro-polishing was always more efficient compared to etching and in case of copper the activity reduction factors for {sup 210}Pb, {sup 210}Bi and {sup 210}Po were between 200 and 400. Etching does not remove {sup 210}Po from copper but works very efficiently from germanium. Results obtained for {sup 210}Pb and {sup 210}Bi for etched stainless steel were worse but still slightly better than those achieved for copper.

  18. Process for recovery of daughter isotopes from a source material

    SciTech Connect

    Tranter, Troy J.; Todd, Terry A.; Lewis, Leroy C.; Henscheid, Joseph P.

    2005-10-04

    The invention includes a method of separating isotopes from a mixture containing at least two isotopes in a solution. A first isotope is precipitated and is collected from the solution. A daughter isotope is generated and collected from the first isotope. The invention includes a method of producing an actinium-225/bismuth-213 product from a material containing thorium-229 and thorium-232. A solution is formed containing nitric acid and the material and iodate is added to form a thorium iodate precipitate. A supernatant is separated from the thorium iodate precipitate and a second volume of nitric acid is added to the precipitate. The precipitate is stored and a decay product comprising actinium-225 and bismuth-213 is generated in the second volume of nitric acid which is then separated from the thorium iodate precipitate, filtered, and treated using at least one chromatographic procedure. The invention also includes a system for producing an actinium-225/bismuth-213 product.

  19. Father-daughter incest: data from an anonymous computerized survey.

    PubMed

    Stroebel, Sandra S; O'Keefe, Stephen L; Beard, Keith W; Kuo, Shih-Ya; Swindell, Samuel V S; Kommor, Martin J

    2012-01-01

    Retrospective data were entered anonymously by 1,521 adult women using computer-assisted self-interview. Nineteen were classified as victims of father-daughter incest, and 241 were classified as victims of sexual abuse by an adult other than their father before reaching 18 years of age. The remaining 1,261 served as controls. Incest victims were more likely than controls to endorse feeling damaged, psychologically injured, estranged from one or both parents, and shamed by others when they tried to open up about their experience. They had been eroticized early on by the incest experience, and it interfered with their adult sexuality. Incest victims experienced coitus earlier than controls and after reaching age 18 had more sex partners and were more likely to have casual sex outside their primary relationship and engage in sex for money than controls. They also had worse scores on scales measuring depression, sexual satisfaction, and communication about sex than controls.

  20. Mummified daughters of King Tutankhamun: archeologic and CT studies.

    PubMed

    Hawass, Zahi; Saleem, Sahar N

    2011-11-01

    The purpose of this study was to use MDCT to examine two mummies found in the tomb of King Tutankhamun to estimate their gestational ages at mummification, to determine the mummification method, and to investigate the congenital deformities of one of the mummies that had been suspected at previous medical examinations. MDCT was performed on the mummies of the daughters of King Tutankhamun (article numbers 317a and 317b), and the images were reconstructed and subjected to forensic imaging analysis. The gestational ages at mummification of mummies 317a and 317b were estimated to be approximately 24.7 and 36.78 weeks. The skeletal congenital anomalies of mummy 317b suggested at past radiographic analysis were ruled out. The results of this study may set a precedent for use of CT and forensic image analysis in the study of ancient mummified fetuses.

  1. Density of founder cells affects spatial pattern formation and cooperation in Bacillus subtilis biofilms.

    PubMed

    van Gestel, Jordi; Weissing, Franz J; Kuipers, Oscar P; Kovács, Akos T

    2014-10-01

    In nature, most bacteria live in surface-attached sedentary communities known as biofilms. Biofilms are often studied with respect to bacterial interactions. Many cells inhabiting biofilms are assumed to express 'cooperative traits', like the secretion of extracellular polysaccharides (EPS). These traits can enhance biofilm-related properties, such as stress resilience or colony expansion, while being costly to the cells that express them. In well-mixed populations cooperation is difficult to achieve, because non-cooperative individuals can reap the benefits of cooperation without having to pay the costs. The physical process of biofilm growth can, however, result in the spatial segregation of cooperative from non-cooperative individuals. This segregation can prevent non-cooperative cells from exploiting cooperative neighbors. Here we examine the interaction between spatial pattern formation and cooperation in Bacillus subtilis biofilms. We show, experimentally and by mathematical modeling, that the density of cells at the onset of biofilm growth affects pattern formation during biofilm growth. At low initial cell densities, co-cultured strains strongly segregate in space, whereas spatial segregation does not occur at high initial cell densities. As a consequence, EPS-producing cells have a competitive advantage over non-cooperative mutants when biofilms are initiated at a low density of founder cells, whereas EPS-deficient cells have an advantage at high cell densities. These results underline the importance of spatial pattern formation for competition among bacterial strains and the evolution of microbial cooperation.

  2. Expression of PGK1 By Prostate Cancer Cells Induces Bone Formation

    PubMed Central

    Jung, Younghun; Shiozawa, Yusuke; Wang, Jianhua; Wang, Jingcheng; Wang, Zhuo; Pedersen, Elisabeth A.; Lee, Clara H.; Hall, Christopher L.; Hogg, Phillip J.; Krebsbach, Paul H.; Keller, Evan T.; Taichman, Russell S.

    2009-01-01

    Prostate cancer (PCa) is one of the solid tumors that metastasize to the bone. Once there, the phenotype of the bone lesions becomes depends upon the balance between osteoblastogenesis and osteoclastogenesis. We previously reported that over-expression of phosphoglycerate kinase 1 (PGK1) in PCa cell lines enhanced bone formation at the metastatic site in vivo. Here, the role of PGK1 in the bone formation was further explored. We demonstrate that PCa-derived PGK1 induces osteoblastic differentiation of bone marrow stromal cells. We also found that PGK1 secreted by PCa inhibits osteoclastogenesis. Finally, the expression levels of the bone specific markers in PCa cell themselves were higher in cells over expressing PGK1 than controls. Together, these data suggest that PGK1 secreted by PCa regulates bone formation at the metastatic site by increasing osteoblastic activity, decreasing osteoclastic function, and expressing an osteoblastic phenotype by PCa themselves. PMID:19825988

  3. Daughter Species Abundances in Comet C/2014 Q2 (Lovejoy)

    NASA Astrophysics Data System (ADS)

    McKay, Adam; Cochran, Anita; Dello Russo, Neil; Kelley, Michael

    2015-11-01

    We present analysis of high spectral resolution optical spectra of C/2014 Q2 (Lovejoy) acquired with the Tull Coude spectrometer on the 2.7-meter Harlan J. Smith Telescope at McDonald Observatory and the ARCES spectrometer mounted on the 3.5-meter Astrophysical Research Consortium Telescope at Apache Point Observatory. Both Tull Coude and ARCES provide high spectral resolution (R=30,000-60,000) and a large spectral range of approximately 3500-10000 Angstroms. We obtained two observation epochs, one in February 2015 at a heliocentric distance of 1.3 AU, and another in May 2015 at a heliocentric distance of 1.9 AU. Another epoch in late August 2015 at a heliocentric distance of 3.0 AU is scheduled. We will present production rates of the daughter species CN, C3, CH, C2, and NH2. We will also present H2O production rates derived from the [OI]6300 emission, as well as measurements of the flux ratio of the [OI]5577 Angstrom line to the sum of the [OI]6300 and [OI]6364 Angstrom lines (sometimes referred to as the oxygen line ratio). This ratio is indicative of the CO2 abundance of the comet. As we have observations at several heliocentric distances, we will examine how production rates and mixing ratios of the various species change with heliocentric distance. We will compare our oxygen line measurements to observations of CO2 made with Spitzer, as well as our other daughter species observations to those of candidate parent molecules made at IR wavelengths.

  4. Epistolary and Emotional Education: The Letters of an Irish Father to His Daughter, 1747-1752

    ERIC Educational Resources Information Center

    Ruberg, Willemijn

    2008-01-01

    The letters Bishop Edward Synge (1691-1762) wrote to his daughter Alicia (1733-1807) in 1747-1752 are discussed to show how correspondence from a father to a daughter could be used to teach a teenage girl how to spell and write letters. Moreover, these letters are an excellent source to show how emotional behaviour was taught. Instructions on…

  5. Caring for a Daughter with Intellectual Disabilities in Managing Menstruation: A Mother's Perspective

    ERIC Educational Resources Information Center

    Chou, Yueh-Ching; Lu, Zxy-Yann Jane

    2012-01-01

    Background: The concerns of mothers and their experiences while providing help to their daughters with intellectual disability (ID) and considerable support needs during menstruation have rarely been addressed. This qualitative study explored mothers' experiences and perceptions of managing their daughters' menstruation. Method: Twelve Taiwanese…

  6. Adolescent Daughters' Romantic Competence: The Role of Divorce, Quality of Parenting, and Maternal Romantic History

    ERIC Educational Resources Information Center

    Shulman, Shmuel; Zlotnik, Aynat; Shachar-Shapira, Lital; Connolly, Jennifer; Bohr, Yvonne

    2012-01-01

    This study examined the links between parental divorce, quality of maternal parenting, spousal relationships and middle adolescent romantic competence in 80 mother-adolescent daughter pairs (40 divorced). Mothers were asked to describe their attitudes and behaviors with regard to their daughters' romantic behavior. In addition, mothers were…

  7. She Has Great Spirit: Insight into Relationships between American Indian Dads and Daughters

    ERIC Educational Resources Information Center

    Reinhardt, Martin James; Perry Evenstad, Jan; Faircloth, Susan

    2012-01-01

    Data from this preliminary study, the American Indian--Dads and Daughters Survey, shed light on how American Indian fathers think and feel about their relationships with their daughters. Respondents represent an array of tribal affiliations, age, occupations, socioeconomic status, and geographical/geopolitical locations, helping to ensure that…

  8. Some Observations of a Father on the Development of His Daughter

    ERIC Educational Resources Information Center

    NAMTA Journal, 2016

    2016-01-01

    This father gives some brief observations of his daughter beginning at the time of her entrance into a Montessori school at the age of three years through the age of six. Through his observations and interactions with his daughter, he gains an awareness of the beauty of the work of the child and leaves the reader with a simple yet powerful…

  9. Caring for a Daughter with Intellectual Disabilities in Managing Menstruation: A Mother's Perspective

    ERIC Educational Resources Information Center

    Chou, Yueh-Ching; Lu, Zxy-Yann Jane

    2012-01-01

    Background: The concerns of mothers and their experiences while providing help to their daughters with intellectual disability (ID) and considerable support needs during menstruation have rarely been addressed. This qualitative study explored mothers' experiences and perceptions of managing their daughters' menstruation. Method: Twelve Taiwanese…

  10. Mother-Daughter Agreement on Adolescent Adopted Chinese Girls' Academic Performance and Internalizing Symptoms

    ERIC Educational Resources Information Center

    Tan, Tony Xing; Marn, Travis

    2014-01-01

    This study reported mother-daughter agreement on adolescent adopted Chinese girls' adjustment. Data on the girls' academic performance and internalizing syndromes were collected from the adopted Chinese girls and their adoptive mothers separately. The adoptive mothers also provided data on mother-daughter relationship quality. There were 219 girls…

  11. From Mother to Daughter: Changes in Intergenerational Educational and Occupational Mobility in Germany

    ERIC Educational Resources Information Center

    Minello, Alessandra; Blossfeld, Hans-Peter

    2014-01-01

    Recent decades have seen a dramatic expansion in the educational attainment and occupational opportunities of German women. Both the educational and occupational positions of the mothers and those of their daughters are continuously changing across cohorts. Our study aims to detect the probability of daughters to experience maternal-line…

  12. She Has Great Spirit: Insight into Relationships between American Indian Dads and Daughters

    ERIC Educational Resources Information Center

    Reinhardt, Martin James; Perry Evenstad, Jan; Faircloth, Susan

    2012-01-01

    Data from this preliminary study, the American Indian--Dads and Daughters Survey, shed light on how American Indian fathers think and feel about their relationships with their daughters. Respondents represent an array of tribal affiliations, age, occupations, socioeconomic status, and geographical/geopolitical locations, helping to ensure that…

  13. Marital and Parent-Child Relationships in Families with Daughters Who Have Eating Disorders

    ERIC Educational Resources Information Center

    Latzer, Yael; Lavee, Yoav; Gal, Sharon

    2009-01-01

    This study assesses and compares the relationship between parents' marital quality, parent-child relationship, and severity of eating-related psychopathology in families with and without eating disorders. Data are collected from the mother, father, and daughter of 30 families with a daughter diagnosed with anorexia or bulimia and from 30 matched…

  14. Like Mother, Like Daughter? A Study of the Socialization of Need for Achievement in Girls.

    ERIC Educational Resources Information Center

    Berens, Anne E.

    A study was conducted to: (1) compare mothers and daughters on their needs for achievement and affiliation and their attitudes to success and failure; and (2) relate the mother's child-raising practices to the daughter's needs. Questionnaires were filled out by mothers and children, and observations of mother-child interaction were made. Ss were…

  15. Conversational Styles of Mothers and Their Preadolescent and Middle Adolescent Daughters.

    ERIC Educational Resources Information Center

    Beaumont, Sherry L.

    2000-01-01

    Compared conversational styles mothers used with preadolescent and middle adolescent daughters with styles used with friends. Found that with friends, mothers used a high involvement style with high rates of overlaps and simultaneous speech, whereas with daughters, they used a high considerateness style with low rates of overlaps and simultaneous…

  16. A Healthy Lifestyle Program for Latino Daughters and Mothers: The BOUNCE Overview and Process Evaluation

    ERIC Educational Resources Information Center

    Olvera, Norma N.; Knox, Brook; Scherer, Rhonda; Maldonado, Gabriela; Sharma, Shreela V.; Alastuey, Lisa; Bush, Jill A.

    2008-01-01

    Background: Few family-based healthy lifestyle programs for Latinos have been conducted, especially family programs targeting mother-daughter dyads. Purpose: To assess the acceptability and feasibility of the Behavior Opportunities Uniting Nutrition Counseling and Exercise (BOUNCE) program designed for Latino mother-daughter pairs. Methods: 92…

  17. Having a Daughter with a Disability: Is It Different for Girls?

    ERIC Educational Resources Information Center

    Horne, Richard, Ed.

    1990-01-01

    This guide focuses on some of the realities parents must face in helping their daughters with disabilities to become more self-reliant and, ultimately, independent. The degree to which daughters with a disability are encouraged to strive for an independent life may be critically less than for sons. These differences have far-reaching implications…

  18. Daughters and Mothers Exercising Together: Effects of Home- and Community-Based Programs.

    ERIC Educational Resources Information Center

    Ransdell, Lynda B.; Taylor, Alison; Oakland, Darcie; Schmidt, Jenny; Moyer-Mileur, Laurie; Shultz, Barry

    2003-01-01

    Compared the effectiveness of home- and community-based physical activity interventions that targeted mothers and daughters to increase physical activity and improve health- related fitness. Data on dyads from community- and home-based programs indicated that mothers and daughters responded positively to both types of programs. Home-based physical…

  19. Internal and Interpersonal: The Family Transmission of Father-Daughter Incest.

    ERIC Educational Resources Information Center

    Greenspun, Wendy S.

    1994-01-01

    Utilizes psychoanalytic and family systems theories to describe dynamics in families with father-daughter incest. The pattern in incest is explained via the concept of projective identification; experiences of victimization are played out in the marriage. The victimized daughter is later triangulated into this marital dynamic, setting the stage…

  20. Common Themes in the Experiences of Mother-Daughter Incest Survivors: Implications for Counseling.

    ERIC Educational Resources Information Center

    Ogilvie, Beverly; Daniluk, Judith

    1995-01-01

    Studied mother-daughter incest. Common themes were extracted from in-depth interviews with survivors of mother-perpetrated sexual abuse, some of which parallel the experience of survivors of other forms of child sexual abuse, and some of which are more specific to mother-daughter incest. Discusses themes and counseling implications. (JBJ)