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Sample records for affect cellular morphology

  1. Mps1 (Monopolar Spindle 1) Protein Inhibition Affects Cellular Growth and Pro-Embryogenic Masses Morphology in Embryogenic Cultures of Araucaria angustifolia (Araucariaceae)

    PubMed Central

    Douétts-Peres, Jackellinne C.; Cruz, Marco Antônio L.; Reis, Ricardo S.; Heringer, Angelo S.; de Oliveira, Eduardo A. G.; Elbl, Paula M.; Floh, Eny I. S.; Silveira, Vanildo

    2016-01-01

    Somatic embryogenesis has been shown to be an efficient tool for studying processes based on cell growth and development. The fine regulation of the cell cycle is essential for proper embryo formation during the process of somatic embryogenesis. The aims of the present work were to identify and perform a structural and functional characterization of Mps1 and to analyze the effects of the inhibition of this protein on cellular growth and pro-embryogenic mass (PEM) morphology in embryogenic cultures of A. angustifolia. A single-copy Mps1 gene named AaMps1 was retrieved from the A. angustifolia transcriptome database, and through a mass spectrometry approach, AaMps1 was identified and quantified in embryogenic cultures. The Mps1 inhibitor SP600125 (10 μM) inhibited cellular growth and changed PEMs, and these effects were accompanied by a reduction in AaMps1 protein levels in embryogenic cultures. Our work has identified the Mps1 protein in a gymnosperm species for the first time, and we have shown that inhibiting Mps1 affects cellular growth and PEM differentiation during A. angustifolia somatic embryogenesis. These data will be useful for better understanding cell cycle control during somatic embryogenesis in plants. PMID:27064899

  2. Geometric morphology of cellular solids

    SciTech Connect

    Schlei, B. R.; Prasad, L.; Skourikhine, A. N.

    2001-01-01

    We demonstrate how to derive morphological information from micrographs, i.e., grey-level images, of polymeric foams. The segmentation of the images is performed by applying a pulse-coupled neural network. This processing generates blobs of the foams walls/struts and voids, respectively. The contours of the blobs and their corresponding points form the input to a constrained Delaunay tessellation, which provides an unstructured grid of the material under consideration. The subsequently applied Chordal Axis Transform captures the intrinsic shape characteristics, and facilitates the identification and localization of key morphological features. While stochastic features of the polymeric foams struts/walls such as areas, aspect ratios, etc., already can be computed at this stage, the foams voids require further geometric processing. The voids are separated into single foam cells. This shape manipulation leads to a refinement of the initial blob contours, which then requires the repeated application of the constrained Delaunay tessellation and Chordal Axis Transform, respectively. Using minimum enclosing rectangles for each foam cell, finally the stochastic features of the foam voids are computed.

  3. Electrodynamic eigenmodes in cellular morphology.

    PubMed

    Cifra, M

    2012-09-01

    Eigenmodes of the spherical and ellipsoidal dielectric electromagnetic resonator have been analysed. The sizes and shape of the resonators have been chosen to represent the shape of the interphase and dividing animal cell. Electromagnetic modes that have shape exactly suitable for positioning of the sufficiently large organelles in cell (centrosome, nucleus) have been identified. We analysed direction and magnitude of dielectrophoretic force exerted on large organelles by electric field of the modes. We found that the TM(1m1) mode in spherical resonator acts by centripetal force which drags the large organelles which have higher permittivity than the cytosol to the center of the cell. TM-kind of mode in the ellipsoidal resonator acts by force on large polarizable organelles in a direction that corresponds to the movement of the centrosomes (also nucleus) observed during the cell division, i.e. to the foci of the ellipsoidal cell. Minimal required force (10(-16) N), gradient of squared electric field and corresponding energy (10(-16) J) of the mode have been calculated to have biological significance within the periods on the order of time required for cell division. Minimal required energy of the mode, in order to have biological significance, can be lower in the case of resonance of organelle with the field of the cellular resonator mode. In case of sufficient energy in the biologically relevant mode, electromagnetic field of the mode will act as a positioning or steering mechanism for centrosome and nucleus in the cell, thus contribute to the spatial and dynamical self-organization in biological systems. PMID:22750075

  4. Clinorotation affects soybean seedling morphology

    NASA Technical Reports Server (NTRS)

    Hilaire, Emmanuel; Guikema, James A.; Brown, Christopher S.

    1995-01-01

    Although spaceflight does not appear to significantly affect seed germination, it can influence subsequent plant growth. On STS-3 and SL-2, decreased growth (measured as plant length, fresh weight, and dry weight) was noted for pine, oat, and mung bean. In the CHROMEX-01 and 02 experiments with Haplopappus and in the CHROMEX-03 experiment with Arabidopsis, enhanced root growth was noted in the space-grown plants. In the CHROMEX-04 experiments with wheat, both leaf fresh weight and leaf area were diminished in the space-grown plants but there was no difference in total plant height (CS Brown, HG Levine, and AD Krikorian, unpublished data). These data suggest that microgravity impacts growth by whole plant partitioning of the assimilates. The objective of the present study was to determine the influence of clinorotation on the growth and the morphology of soybean seedlings grown in the Biological Research In Canister (BRIC) flight hardware. This experiment provided baseline data for a spaceflight experiment (BRIC-3) flown on STS-63 (February 3-11, 1995).

  5. Factors affecting spermatozoa morphology in beef bulls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate factors affecting sperm morphology of bulls (n=908) collected at 320 days of age. Bulls were a composite breed (50% Red Angus, 25% Charolais, and 25% Tarentaise) born from 2002 to 2008 to dams fed levels of feed during mid and late gestation that were expe...

  6. The Flagellum Attachment Zone: 'The Cellular Ruler' of Trypanosome Morphology.

    PubMed

    Sunter, Jack D; Gull, Keith

    2016-04-01

    A defining feature of Trypanosoma brucei cell shape is the lateral attachment of the flagellum to the cell body, mediated by the flagellum attachment zone (FAZ). The FAZ is a complex cytoskeletal structure that connects the flagellum skeleton through two membranes to the cytoskeleton. The FAZ acts as a 'cellular ruler' of morphology by regulating cell length and organelle position and is therefore critical for both cell division and life cycle differentiations. Here we provide an overview of the advances in our understanding of the composition, assembly, and function of the FAZ. PMID:26776656

  7. Characterization of Morphological and Cellular Events Underlying Oral Regeneration in the Sea Anemone, Nematostella vectensis.

    PubMed

    Amiel, Aldine R; Johnston, Hereroa T; Nedoncelle, Karine; Warner, Jacob F; Ferreira, Solène; Röttinger, Eric

    2015-01-01

    Cnidarians, the extant sister group to bilateria, are well known for their impressive regenerative capacity. The sea anemone Nematostella vectensis is a well-established system for the study of development and evolution that is receiving increased attention for its regenerative capacity. Nematostella is able to regrow missing body parts within five to six days after its bisection, yet studies describing the morphological, cellular, and molecular events underlying this process are sparse and very heterogeneous in their experimental approaches. In this study, we lay down the basic framework to study oral regeneration in Nematostella vectensis. Using various imaging and staining techniques we characterize in detail the morphological, cellular, and global molecular events that define specific landmarks of this process. Furthermore, we describe in vivo assays to evaluate wound healing success and the initiation of pharynx reformation. Using our described landmarks for regeneration and in vivo assays, we analyze the effects of perturbing either transcription or cellular proliferation on the regenerative process. Interestingly, neither one of these experimental perturbations has major effects on wound closure, although they slightly delay or partially block it. We further show that while the inhibition of transcription blocks regeneration in a very early step, inhibiting cellular proliferation only affects later events such as pharynx reformation and tentacle elongation. PMID:26633371

  8. Characterization of Morphological and Cellular Events Underlying Oral Regeneration in the Sea Anemone, Nematostella vectensis

    PubMed Central

    Amiel, Aldine R.; Johnston, Hereroa T.; Nedoncelle, Karine; Warner, Jacob F.; Ferreira, Solène; Röttinger, Eric

    2015-01-01

    Cnidarians, the extant sister group to bilateria, are well known for their impressive regenerative capacity. The sea anemone Nematostella vectensis is a well-established system for the study of development and evolution that is receiving increased attention for its regenerative capacity. Nematostella is able to regrow missing body parts within five to six days after its bisection, yet studies describing the morphological, cellular, and molecular events underlying this process are sparse and very heterogeneous in their experimental approaches. In this study, we lay down the basic framework to study oral regeneration in Nematostella vectensis. Using various imaging and staining techniques we characterize in detail the morphological, cellular, and global molecular events that define specific landmarks of this process. Furthermore, we describe in vivo assays to evaluate wound healing success and the initiation of pharynx reformation. Using our described landmarks for regeneration and in vivo assays, we analyze the effects of perturbing either transcription or cellular proliferation on the regenerative process. Interestingly, neither one of these experimental perturbations has major effects on wound closure, although they slightly delay or partially block it. We further show that while the inhibition of transcription blocks regeneration in a very early step, inhibiting cellular proliferation only affects later events such as pharynx reformation and tentacle elongation. PMID:26633371

  9. Targeted cellular ablation based on the morphology of malignant cells

    PubMed Central

    Ivey, Jill W.; Latouche, Eduardo L.; Sano, Michael B.; Rossmeisl, John H.; Davalos, Rafael V.; Verbridge, Scott S.

    2015-01-01

    Treatment of glioblastoma multiforme (GBM) is especially challenging due to a shortage of methods to preferentially target diffuse infiltrative cells, and therapy-resistant glioma stem cell populations. Here we report a physical treatment method based on electrical disruption of cells, whose action depends strongly on cellular morphology. Interestingly, numerical modeling suggests that while outer lipid bilayer disruption induced by long pulses (~100 μs) is enhanced for larger cells, short pulses (~1 μs) preferentially result in high fields within the cell interior, which scale in magnitude with nucleus size. Because enlarged nuclei represent a reliable indicator of malignancy, this suggested a means of preferentially targeting malignant cells. While we demonstrate killing of both normal and malignant cells using pulsed electric fields (PEFs) to treat spontaneous canine GBM, we proposed that properly tuned PEFs might provide targeted ablation based on nuclear size. Using 3D hydrogel models of normal and malignant brain tissues, which permit high-resolution interrogation during treatment testing, we confirmed that PEFs could be tuned to preferentially kill cancerous cells. Finally, we estimated the nuclear envelope electric potential disruption needed for cell death from PEFs. Our results may be useful in safely targeting the therapy-resistant cell niches that cause recurrence of GBM tumors. PMID:26596248

  10. Targeted cellular ablation based on the morphology of malignant cells.

    PubMed

    Ivey, Jill W; Latouche, Eduardo L; Sano, Michael B; Rossmeisl, John H; Davalos, Rafael V; Verbridge, Scott S

    2015-01-01

    Treatment of glioblastoma multiforme (GBM) is especially challenging due to a shortage of methods to preferentially target diffuse infiltrative cells, and therapy-resistant glioma stem cell populations. Here we report a physical treatment method based on electrical disruption of cells, whose action depends strongly on cellular morphology. Interestingly, numerical modeling suggests that while outer lipid bilayer disruption induced by long pulses (~100 μs) is enhanced for larger cells, short pulses (~1 μs) preferentially result in high fields within the cell interior, which scale in magnitude with nucleus size. Because enlarged nuclei represent a reliable indicator of malignancy, this suggested a means of preferentially targeting malignant cells. While we demonstrate killing of both normal and malignant cells using pulsed electric fields (PEFs) to treat spontaneous canine GBM, we proposed that properly tuned PEFs might provide targeted ablation based on nuclear size. Using 3D hydrogel models of normal and malignant brain tissues, which permit high-resolution interrogation during treatment testing, we confirmed that PEFs could be tuned to preferentially kill cancerous cells. Finally, we estimated the nuclear envelope electric potential disruption needed for cell death from PEFs. Our results may be useful in safely targeting the therapy-resistant cell niches that cause recurrence of GBM tumors. PMID:26596248

  11. Targeted cellular ablation based on the morphology of malignant cells

    NASA Astrophysics Data System (ADS)

    Ivey, Jill W.; Latouche, Eduardo L.; Sano, Michael B.; Rossmeisl, John H.; Davalos, Rafael V.; Verbridge, Scott S.

    2015-11-01

    Treatment of glioblastoma multiforme (GBM) is especially challenging due to a shortage of methods to preferentially target diffuse infiltrative cells, and therapy-resistant glioma stem cell populations. Here we report a physical treatment method based on electrical disruption of cells, whose action depends strongly on cellular morphology. Interestingly, numerical modeling suggests that while outer lipid bilayer disruption induced by long pulses (~100 μs) is enhanced for larger cells, short pulses (~1 μs) preferentially result in high fields within the cell interior, which scale in magnitude with nucleus size. Because enlarged nuclei represent a reliable indicator of malignancy, this suggested a means of preferentially targeting malignant cells. While we demonstrate killing of both normal and malignant cells using pulsed electric fields (PEFs) to treat spontaneous canine GBM, we proposed that properly tuned PEFs might provide targeted ablation based on nuclear size. Using 3D hydrogel models of normal and malignant brain tissues, which permit high-resolution interrogation during treatment testing, we confirmed that PEFs could be tuned to preferentially kill cancerous cells. Finally, we estimated the nuclear envelope electric potential disruption needed for cell death from PEFs. Our results may be useful in safely targeting the therapy-resistant cell niches that cause recurrence of GBM tumors.

  12. ST1571 (imatinib mesylate) reduces bone marrow cellularity and normalizes morphologic features irrespective of cytogenetic response.

    PubMed

    Hasserjian, Robert P; Boecklin, Federica; Parker, Sally; Chase, Andy; Dhar, Sunanda; Zaiac, Michael; Olavarria, Eduardo; Lampert, Irvin; Henry, Kristin; Apperley, Jane F; Goldman, John M

    2002-03-01

    The tyrosine kinase inhibitor STI571 (imatinib mesylate, Gleevec) is an effective treatment for chronic myeloid leukemia (CML). We examined bone marrow samples from 53 patients with CML who were receiving STI571 in 3 multicenter phase 2 trials to assess morphologic changes and cytogenetic response to this drug. In most patients with initially increased blasts, the bone marrow blast count rapidly decreased during STI571 therapy. Reductions in cellularity, the myeloid/erythroid ratio (commonly with relative erythroid hyperplasia), and reticulin fibrosis (if present pretreatment) also were seen in most patients, resulting in an appearance resembling normal marrow in many cases. Eighteen patients (34%) had some degree of cytogenetic response. Surprisingly, these striking morphologic changes occurred irrespective of any cytogenetic response to STI571. Thus, STI571 seems to affect the differentiation of CML cells in vivo, causing even extensively Philadelphia chromosome-positive hematopoiesis to exhibitfeatures resembling normal hematopoiesis. PMID:11888075

  13. Digital and traditional slides for teaching cellular morphology: a comparative analysis of learning outcomes.

    PubMed

    Solberg, Brooke L

    2012-01-01

    Recent advances in technology have brought forth an intriguing new tool for teaching hematopoietic cellular identification skills: the digital slide. Although digitized slides offer a number of appealing options for educators, little research has been done to examine how their utilization would impact learning outcomes. To fill that void, this study was designed to examine student performance, skill retention and transferability, and self-efficacy beliefs amongst undergraduate MLS students learning cellular morphology with digital versus traditional slides. Results showed that students learning with digital slides performed better on assessments containing only traditional slide specimens than students learning with traditional slides, both immediately following the learning activity and after a considerable duration of time. Students learning with digital slides also reported slightly higher levels of self-efficacy related to cellular identification. The findings of this study suggest that students learning cellular identification skills with digital slides are able to transfer that skill directly to traditional slides, and that their ability to identify cells is not negatively affected in present or future settings. PMID:23397880

  14. Morphological and cellular changes within embryonic striatal grafts associated with enriched environment and involuntary exercise.

    PubMed

    Döbrössy, Máté D; Dunnett, Stephen B

    2006-12-01

    Environmental enrichment (EE) and exercise have been implicated in influencing behaviour and altering neuronal processes associated with cellular morphology in both 'normal' and injured states of the CNS. Using a rodent model of Huntington's disease, we investigated whether prolonged EE or involuntary exercise can induce morphological and cellular changes within embryonic striatal transplants. Adult rats were trained on the Staircase test--requiring fine motor control to reach and collect reward pellets--prior to being lesioned unilaterally in the dorsal neostriatum with quinolinic acid. The lesioned animals received E15 whole ganglionic eminence cell suspension grafts followed by housing in EE or standard cages. Half of the animals in standard cages received daily forced exercise on a treadmill. The grafted animals showed significant functional recovery on both the Staircase test and in drug-induced rotation. Neither the housing conditions nor the training had an impact on the behaviour, with the exception of the treadmill reducing the ipsilateral drug-induced rotation observed amongst the lesioned animals. However, the animals housed in the EE had significantly increased striatal brain-derived neurotrophic factor (BDNF) levels, and graft neurons in these animals exhibited both greater spine densities and larger cell volumes. Animals on forced exercise regime had reduced BDNF levels and grafted cells with sparser spines. The study suggests that the context of the animal can affect the plasticity of transplanted cells. Appropriately exploiting the underlying, and yet unknown, mechanisms could lead the way to improved anatomical and potentially functional integration of the graft. PMID:17156383

  15. Short-term exposure to engineered nanomaterials affects cellular epigenome

    PubMed Central

    Lu, Xiaoyan; Miousse, Isabelle R.; Pirela, Sandra V.; Melnyk, Stepan; Koturbash, Igor; Demokritou, Philip

    2015-01-01

    Extensive incorporation of engineered nanomaterials (ENMs) into industrial and biomedical applications increases the risks of exposure to these potentially hazardous materials. While the geno- and cytotoxic effects of ENMs have been investigated, the potential of ENMs to target the cellular epigenome remains largely unknown. Our goal was to determine whether or not industry relevant ENMs can affect the epigenome at low cytotoxic doses. A panel of cells relevant to inhalation exposures such as human and murine macrophages (THP-1 and RAW264.7, respectively) and human small airway epithelial cells (SAEC) were exposed to printer-emitted engineered nanoparticles (PEPs), mild steel welding fumes (MS-WF), copper oxide (CuO), and titanium dioxide (TiO2) nanoparticles. Toxicological effects, including cytotoxicity, oxidative stress, and inflammatory responses were assessed, taking into consideration in-vitro dosimetry. The effects of ENMs on cellular epigenome were determined by addressing the global and transposable elements (TEs)-associated DNA methylation and expression of DNA methylation machinery and TEs. The percentage of ENMs-induced cytotoxicity for all cell lines was in the range of 0-15%. Oxidative stress was evident in SAEC after exposure to PEPs and in THP-1 when exposed to CuO. Additionally, exposure to ENMs resulted in modest alterations in DNA methylation of two most abundant TEs in mammalian genomes, LINE-1 and Alu/SINE, their transcriptional reactivation, and decreased expression of DNA methylation machinery in a cell-, dose-, and ENM-dependent manner. These results indicate that exposure to ENMs at environmentally relevant concentrations, aside from the geno- and cytotoxic effects, can also affect the epigenome of target cells. PMID:25938281

  16. Short-term exposure to engineered nanomaterials affects cellular epigenome.

    PubMed

    Lu, Xiaoyan; Miousse, Isabelle R; Pirela, Sandra V; Melnyk, Stepan; Koturbash, Igor; Demokritou, Philip

    2016-01-01

    Extensive incorporation of engineered nanomaterials (ENMs) into industrial and biomedical applications increases the risks of exposure to these potentially hazardous materials. While the geno- and cytotoxic effects of ENMs have been investigated, the potential of ENMs to target the cellular epigenome remains largely unknown. Our goal was to determine whether industry relevant ENMs can affect the epigenome at low cytotoxic doses. A panel of cells relevant to inhalation exposures such as human and murine macrophages (THP-1 and RAW264.7, respectively) and human small airway epithelial cells (SAEC) were exposed to printer-emitted engineered nanoparticles (PEPs), mild steel welding fumes (MS-WF), copper oxide (CuO) and titanium dioxide nanoparticles. Toxicological effects, including cytotoxicity, oxidative stress and inflammatory responses were assessed, taking into consideration in vitro dosimetry. The effects of ENMs on cellular epigenome were determined by addressing the global and transposable elements (TEs)-associated DNA methylation and expression of DNA methylation machinery and TEs. The percentage of ENMs-induced cytotoxicity for all cell lines was in the range of 0-15%. Oxidative stress was evident in SAEC after exposure to PEPs and in THP-1 when exposed to CuO. In addition, exposure to ENMs resulted in modest alterations in DNA methylation of two most abundant TEs in mammalian genomes, LINE-1 and Alu/SINE, their transcriptional reactivation, and decreased expression of DNA methylation machinery in a cell-, dose- and ENM-dependent manner. These results indicate that exposure to ENMs at environmentally relevant concentrations, aside from the geno- and cytotoxic effects, can also affect the epigenome of target cells. PMID:25938281

  17. Cellular and morphological aspects of fibrodysplasia ossificans progressiva

    PubMed Central

    Martelli, Anderson; Santos, Arnaldo Rodrigues

    2014-01-01

    Fibrodysplasia ossificans progressiva (FOP) is a rare congenital disease that causes bone formation within the muscles, tendons, ligaments and connective tissues. There is no cure for this disorder and only treatment of the symptoms is available. The purpose of this study was to review the literature and describe the clinical, cellular and molecular aspects of FOP. The material used for the study was obtained by reviewing scientific articles published in various literature-indexed databases. In view of its rarity and of the lack of insightful information and the unpredictability of its course, FOP is a challenging disorder for professionals who are confronted by it. However, this rare disease raises a great deal of interest because understanding the mechanism of mature bone formation can encourage research lines related to bone regeneration and the prevention of heterotopic ossification. PMID:25482313

  18. Cellular responses to endogenous electrochemical gradients in morphological development

    NASA Astrophysics Data System (ADS)

    Desrosiers, M. F.

    Endogenous electric fields give vectorial direction to morphological development in Zea mays (sweet corn) in response to gravity. Endogenous electrical fields are important because of their ability to influence: 1) intercellular organization and development through their effects on the membrane potential, 2) direct effects such as electrophoresis of membrane components, and 3) both intracellular and extracellular transport of charged compounds. Their primary influence is in providing a vectorial dimension to the progression of one physiological state to another. Gravity perception and transduction in the mesocotyl of vascular plants is a complex interplay of electrical and chemical gradients which ultimately provide the driving force for the resulting growth curvature called gravitropism. Among the earliest events in gravitropism are changes in impedance, voltage, and conductance between the vascular stele and the growth tissues, the cortex, in the mesocotyl of corn shoots. In response to gravistimulation: 1) a potential develops which is vectorial and of sufficient magnitude to be a driving force for transport between the vascular stele and cortex, 2) the ionic conductance changes within seconds showing altered transport between the tissues, and 3) the impedance shows a transient biphasic response which indicates that the mobility of charges is altered following gravistimulation and is possibly the triggering event for the cascade of actions which leads to growth curvature.

  19. Cellular responses to endogenous electrochemical gradients in morphological development

    NASA Technical Reports Server (NTRS)

    Desrosiers, M. F.

    1996-01-01

    Endogenous electric fields give vectorial direction to morphological development in Zea mays (sweet corn) in response to gravity. Endogenous electrical fields are important because of their ability to influence: (1) intercellular organization and development through their effects on the membrane potential, (2) direct effects such as electrophoresis of membrane components, and (3) both intracellular and extracellular transport of charged compounds. Their primary influence is in providing a vectorial dimension to the progression of one physiological state to another. Gravity perception and transduction in the mesocotyl of vascular plants is a complex interplay of electrical and chemical gradients which ultimately provide the driving force for the resulting growth curvature called gravitropism. Among the earliest events in gravitropism are changes in impedance, voltage, and conductance between the vascular stele and the growth tissues, the cortex, in the mesocotyl of corn shoots. In response to gravistimulation: (1) a potential develops which is vectorial and of sufficient magnitude to be a driving force for transport between the vascular stele and cortex, (2) the ionic conductance changes within seconds showing altered transport between the tissues, and (3) the impedance shows a transient biphasic response which indicates that the mobility of charges is altered following gravistimulation and is possibly the triggering event for the cascade of actions which leads to growth curvature.

  20. Closed-form density-based framework for automatic detection of cellular morphology changes.

    PubMed

    Duong, Tarn; Goud, Bruno; Schauer, Kristine

    2012-05-29

    A primary method for studying cellular function is to examine cell morphology after a given manipulation. Fluorescent markers attached to proteins/intracellular structures of interest in conjunction with 3D fluorescent microscopy are frequently exploited for functional analysis. Despite the central role of morphology comparisons in cell biological approaches, few statistical tools are available that allow biological scientists without a high level of statistical training to quantify the similarity or difference of fluorescent images containing multifactorial information. We transform intracellular structures into kernels and develop a multivariate two-sample test that is nonparametric and asymptotically normal to directly and quantitatively compare cellular morphologies. The asymptotic normality bypasses the computationally intensive calculations used by the usual resampling techniques to compute the P-value. Because all parameters required for the statistical test are estimated directly from the data, it does not require any subjective decisions. Thus, we provide a black-box method for unbiased, automated comparison of cell morphology. We validate the performance of our test statistic for finite synthetic samples and experimental data. Employing our test for the comparison of the morphology of intracellular multivesicular bodies, we detect changes in their distribution after disruption of the cellular microtubule cytoskeleton with high statistical significance in fixed samples and live cell analysis. These results demonstrate that density-based comparison of multivariate image information is a powerful tool for automated detection of cell morphology changes. Moreover, the underlying mathematics of our test statistic is a general technique, which can be applied in situations where two data samples are compared. PMID:22586080

  1. Personality and morphological traits affect pigeon survival from raptor attacks.

    PubMed

    Santos, Carlos D; Cramer, Julia F; Pârâu, Liviu G; Miranda, Ana C; Wikelski, Martin; Dechmann, Dina K N

    2015-01-01

    Personality traits have recently been shown to impact fitness in different animal species, potentially making them similarly relevant drivers as morphological and life history traits along the evolutionary pathways of organisms. Predation is a major force of natural selection through its deterministic effects on individual survival, but how predation pressure has helped to shape personality trait selection, especially in free-ranging animals, remains poorly understood. We used high-precision GPS tracking to follow whole flocks of homing pigeons (Columba livia) with known personalities and morphology during homing flights where they were severely predated by raptors. This allowed us to determine how the personality and morphology traits of pigeons may affect their risk of being predated by raptors. Our survival model showed that individual pigeons, which were more tolerant to human approach, slower to escape from a confined environment, more resistant to human handling, with larger tarsi, and with lighter plumage, were more likely to be predated by raptors. We provide rare empirical evidence that the personality of prey influences their risk of being predated under free-ranging circumstances. PMID:26489437

  2. Personality and morphological traits affect pigeon survival from raptor attacks

    PubMed Central

    Santos, Carlos D.; Cramer, Julia F.; Pârâu, Liviu G.; Miranda, Ana C.; Wikelski, Martin; Dechmann, Dina K. N.

    2015-01-01

    Personality traits have recently been shown to impact fitness in different animal species, potentially making them similarly relevant drivers as morphological and life history traits along the evolutionary pathways of organisms. Predation is a major force of natural selection through its deterministic effects on individual survival, but how predation pressure has helped to shape personality trait selection, especially in free-ranging animals, remains poorly understood. We used high-precision GPS tracking to follow whole flocks of homing pigeons (Columba livia) with known personalities and morphology during homing flights where they were severely predated by raptors. This allowed us to determine how the personality and morphology traits of pigeons may affect their risk of being predated by raptors. Our survival model showed that individual pigeons, which were more tolerant to human approach, slower to escape from a confined environment, more resistant to human handling, with larger tarsi, and with lighter plumage, were more likely to be predated by raptors. We provide rare empirical evidence that the personality of prey influences their risk of being predated under free-ranging circumstances. PMID:26489437

  3. Physicochemical, morphological and cellular uptake properties of lutein nanodispersions prepared by using surfactants with different stabilizing mechanisms.

    PubMed

    Tan, Tai Boon; Chu, Wern Cui; Yussof, Nor Shariffa; Abas, Faridah; Mirhosseini, Hamed; Cheah, Yoke Kqueen; Nehdi, Imededdine Arbi; Tan, Chin Ping

    2016-04-20

    In this study, we prepared a series of lutein nanodispersions via the solvent displacement method, by using surfactants with different stabilizing mechanisms. The surfactants used include Tween 80 (steric stabilization), sodium dodecyl sulfate (SDS; electrostatic stabilization), sodium caseinate (electrosteric stabilization) and SDS-Tween 80 (electrostatic-steric stabilization). We then characterized the resulting lutein nanodispersions in terms of their particle size, particle size distribution, zeta potential, lutein content, flow behavior, apparent viscosity, transmittance, color, morphological properties and their effects on cell viability and cellular uptake. The type of surfactant used significantly (p < 0.05) affected the physical properties of the nanodispersions, but the chemical properties (lutein content) remained unaffected. Transmission electron microscopy (TEM) images obtained from this study demonstrated that the solvent displacement method was capable of producing lutein nanodispersions containing spherical particles with sizes ranging from 66.20-125.25 nm, depending on the type of surfactant used. SDS and SDS-Tween 80 surfactants negatively affected the viability of the HT-29 cells used in this study. Thus, for the cellular uptake determination, only Tween 80 and sodium caseinate surfactants were used. The cellular uptake of the lutein nanodispersion stabilized by sodium caseinate was higher than that which was stabilized by Tween 80. All things considered, the type of surfactant with different stabilizing mechanisms did produce lutein nanodispersions with different characteristics. These findings would aid in future selection of surfactants in order to produce nanodispersions with desirable properties. PMID:27010495

  4. Cellular cofactors affecting hepatitis C virus infection and replication

    PubMed Central

    Randall, Glenn; Panis, Maryline; Cooper, Jacob D.; Tellinghuisen, Timothy L.; Sukhodolets, Karen E.; Pfeffer, Sebastien; Landthaler, Markus; Landgraf, Pablo; Kan, Sherry; Lindenbach, Brett D.; Chien, Minchen; Weir, David B.; Russo, James J.; Ju, Jingyue; Brownstein, Michael J.; Sheridan, Robert; Sander, Chris; Zavolan, Mihaela; Tuschl, Thomas; Rice, Charles M.

    2007-01-01

    Recently identified hepatitis C virus (HCV) isolates that are infectious in cell culture provide a genetic system to evaluate the significance of virus–host interactions for HCV replication. We have completed a systematic RNAi screen wherein siRNAs were designed that target 62 host genes encoding proteins that physically interact with HCV RNA or proteins or belong to cellular pathways thought to modulate HCV infection. This includes 10 host proteins that we identify in this study to bind HCV NS5A. siRNAs that target 26 of these host genes alter infectious HCV production >3-fold. Included in this set of 26 were siRNAs that target Dicer, a principal component of the RNAi silencing pathway. Contrary to the hypothesis that RNAi is an antiviral pathway in mammals, as has been reported for subgenomic HCV replicons, siRNAs that target Dicer inhibited HCV replication. Furthermore, siRNAs that target several other components of the RNAi pathway also inhibit HCV replication. MicroRNA profiling of human liver, human hepatoma Huh-7.5 cells, and Huh-7.5 cells that harbor replicating HCV demonstrated that miR-122 is the predominant microRNA in each environment. miR-122 has been previously implicated in positively regulating the replication of HCV genotype 1 replicons. We find that 2′-O-methyl antisense oligonucleotide depletion of miR-122 also inhibits HCV genotype 2a replication and infectious virus production. Our data define 26 host genes that modulate HCV infection and indicate that the requirement for functional RNAi for HCV replication is dominant over any antiviral activity this pathway may exert against HCV. PMID:17616579

  5. Building quantitative, three dimensional atlases of gene expression and morphology at cellular resolution

    PubMed Central

    Knowles, David W.; Biggin, Mark D.

    2013-01-01

    Animals comprise dynamic three-dimensional arrays of cells that express gene products in intricate spatial and temporal patterns that determine cellular differentiation and morphogenesis. A rigorous understanding of these developmental processes requires automated methods that quantitatively record and analyze complex morphologies and their associated patterns of gene expression at cellular resolution. Here we summarize light microscopy based approaches to establish permanent, quantitative datasets—atlases—that record this information. We focus on experiments that capture data for whole embryos or large areas of tissue in three dimensions, often at multiple time points. We compare and contrast the advantages and limitations of different methods and highlight some of the discoveries made. We emphasize the need for interdisciplinary collaborations and integrated experimental pipelines that link sample preparation, image acquisition, image analysis, database design, visualization and quantitative analysis. PMID:24123936

  6. The Flagellum Attachment Zone: ‘The Cellular Ruler’ of Trypanosome Morphology

    PubMed Central

    Sunter, Jack D.; Gull, Keith

    2016-01-01

    A defining feature of Trypanosoma brucei cell shape is the lateral attachment of the flagellum to the cell body, mediated by the flagellum attachment zone (FAZ). The FAZ is a complex cytoskeletal structure that connects the flagellum skeleton through two membranes to the cytoskeleton. The FAZ acts as a ‘cellular ruler’ of morphology by regulating cell length and organelle position and is therefore critical for both cell division and life cycle differentiations. Here we provide an overview of the advances in our understanding of the composition, assembly, and function of the FAZ. PMID:26776656

  7. Time Dependence of Tip Morphology during Cellular/Dendritic Arrayed Growth

    NASA Technical Reports Server (NTRS)

    Song, H.; Tewari, S. N.

    1996-01-01

    Succinonitrile-1.9 wt pct acetone has been directionally solidified in 0.7 X 0.7-cm-square cross section pyrex ampoules in order to observe the cell/dendrite tip morphologies, not influenced by the 'wall effects', which are present during growth in the generally used thin (about 200 gm) crucibles. The tips do not maintain a steady-state shape, as is generally assumed. Instead, they fluctuate within a shape envelope. The extent of fluctuation increases with decreasing growth speed, as the micro structure changes from the dendritic to cellular. The influence of natural convection has been examined by comparing these morphologies with those grown, without convection, in the thin ampoules.

  8. Cellular Responses during Morphological Transformation in Azospirillum brasilense and Its flcA Knockout Mutant

    PubMed Central

    Coumans, Joëlle V. F.; Poljak, Anne; Raftery, Mark J.; Pereg, Lily

    2014-01-01

    FlcA is a response regulator controlling flocculation and the morphological transformation of Azospirillum cells from vegetative to cyst-like forms. To understand the cellular responses of Azospirillum to conditions that cause morphological transformation, proteins differentially expressed under flocculation conditions in A. brasilense Sp7 and its flcA knockout mutant were investigated. Comparison of 2-DE protein profiles of wild-type (Sp7) and a flcA deletion mutant (Sp7-flcAΔ) revealed a total of 33 differentially expressed 2-DE gel spots, with 22 of these spots confidently separated to allow protein identification. Analysis of these spots by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and MASCOT database searching identified 48 proteins (≥10% emPAI in each spot). The functional characteristics of these proteins included carbon metabolism (beta-ketothiolase and citrate synthase), nitrogen metabolism (Glutamine synthetase and nitric oxide synthase), stress tolerance (superoxide dismutase, Alkyl hydroperoxidase and ATP-dependent Clp protease proteolytic subunit) and morphological transformation (transducer coupling protein). The observed differences between Sp7 wild-type and flcA− strains enhance our understanding of the morphological transformation process and help to explain previous phenotypical observations. This work is a step forward in connecting the Azospirillum phenome and genome. PMID:25502569

  9. Three-dimensional morphology and gene expression in the Drosophila blastoderm at cellular resolution II: dynamics

    PubMed Central

    Keränen, Soile VE; Fowlkes, Charless C; Luengo Hendriks, Cris L; Sudar, Damir; Knowles, David W; Malik, Jitendra; Biggin, Mark D

    2006-01-01

    Background To accurately describe gene expression and computationally model animal transcriptional networks, it is essential to determine the changing locations of cells in developing embryos. Results Using automated image analysis methods, we provide the first quantitative description of temporal changes in morphology and gene expression at cellular resolution in whole embryos, using the Drosophila blastoderm as a model. Analyses based on both fixed and live embryos reveal complex, previously undetected three-dimensional changes in nuclear density patterns caused by nuclear movements prior to gastrulation. Gene expression patterns move, in part, with these changes in morphology, but additional spatial shifts in expression patterns are also seen, supporting a previously proposed model of pattern dynamics based on the induction and inhibition of gene expression. We show that mutations that disrupt either the anterior/posterior (a/p) or the dorsal/ventral (d/v) transcriptional cascades alter morphology and gene expression along both the a/p and d/v axes in a way suggesting that these two patterning systems interact via both transcriptional and morphological mechanisms. Conclusion Our work establishes a new strategy for measuring temporal changes in the locations of cells and gene expression patterns that uses fixed cell material and computational modeling. It also provides a coordinate framework for the blastoderm embryo that will allow increasingly accurate spatio-temporal modeling of both the transcriptional control network and morphogenesis. PMID:17184547

  10. Temperature affects the silicate morphology in a diatom

    PubMed Central

    Javaheri, N.; Dries, R.; Burson, A.; Stal, L. J.; Sloot, P. M. A.; Kaandorp, J. A.

    2015-01-01

    Silica deposition by diatoms, a common component of the phytoplankton, has attracted considerable interest given the importance in ecology and materials science. There has recently been a great deal of research into the biological control of biosilicifcation, yet the in vivo physical and chemical effects have not been quantitatively investigated. We have grown the marine diatom Thalassiosira pseudonana in batch culture at three temperatures (14o, 18o, and 23 °C). We observed three distinct temperature-dependent growth phases. The morphology of silica was investigated using scanning electron microscopy followed by image analysis and supervised learning. The silica in the valves of the same species showed different structures: a mesh-like pattern in silicon-rich cultures and a tree-like pattern in silicon-limited cultures. Moreover, temperature affected this silica pattern, especially in silicon-limited cultures. We conclude that cells grown at 14 °C and 18 °C divide more successfully in Si-limited conditions by developing a tree-like pattern (lower silicification). PMID:26113515

  11. Teratogenic potency of valproate analogues evaluated by quantitative estimation of cellular morphology in vitro.

    PubMed

    Berezin, V; Kawa, A; Bojic, U; Foley, A; Nau, H; Regan, C; Edvardsen, K; Bock, E

    1996-10-01

    To develop a simple prescreening system for teratogenicity testing, a novel in vitro assay was established using computer assisted microscopy allowing automatic delineation of contours of stained cells and thereby quantitative determination of cellular morphology. The effects of valproic acid (VPA) and analogues with high as well as low teratogenic activities-(as previously determined in vivo)-were used as probes for study of the discrimination power of the in vitro model. VPA, a teratogenic analogue (+/-)-4-en-VPA, and a non-teratogenic analogue (E)-2-en-VPA, as well as the purified (S)- and (R)-enantiomers of 4-yn-VPA (teratogenic and non-teratogenic, respectively), were tested for their effects on cellular morphology of cloned mouse fibroblastoid L-cell lines, neuroblastoma N2a cells, and rat glioma BT4Cn cells, and were found to induce varying increases in cellular area: Furthermore, it was demonstrated that under the chosen conditions the increase in area correlated statistically significantly with the teratogenic potency of the employed compounds. Setting the cellular area of mouse L-cells to 100% under control conditions, the most pronounced effect was observed for (S)-4-yn-VPA (211%, P = < 0.001) followed by VPA (186%, P < 0.001), 4-en-VPA (169%, P < 0.001) and non-teratogenic 2-en-VPA (137%, P < 0.005) and (R)-4-yn-VPA (105%). This effect was independent of the choice of substrata, since it was observed on L-cells grown on plastic, fibronectin, laminin and Matrigel. However, when VPA-treated cells were exposed to an arginyl-glycyl-aspartate (RGD)-containing peptide to test whether VPA treatment was able to modulate RGD-dependent integrin interactions with components of the extracellular matrix, hardly any effect could be observed, whereas control cells readily detached from the substratum, indicating a changed substrate adhesion of the VPA-treated cells. The data thus indicate that measurement of cellular area may serve as a simple in vitro test in the

  12. Myoblasts from affected and non-affected FSHD muscles exhibit morphological differentiation defects

    PubMed Central

    Barro, Marietta; Carnac, Gilles; Flavier, Sébastien; Mercier, Jacques; Vassetzky, Yegor; Laoudj-Chenivesse, Dalila

    2010-01-01

    Abstract Facioscapulohumeral dystrophy (FSHD) is a muscular hereditary disease with a prevalence of 1 in 20,000 caused by a partial deletion of a subtelomeric repeat array on chromosome 4q. However, very little is known about the pathogenesis as well as the molecular and biochemical changes linked to the progressive muscle degeneration observed in these patients. Several studies have investigated possible pathophysiological pathways in FSHD myoblasts and mature muscle cells but some of these reports were apparently in contradiction. The discrepancy between these studies may be explained by differences between the sources of myoblasts. Therefore, we decided to thoroughly analyze affected and unaffected muscles from patients with FSHD in terms of vulnerability to oxidative stress, differentiation capacity and morphological abnormalities. We have established a panel of primary myoblast cell cultures from patients affected with FSHD and matched healthy individuals. Our results show that primary myoblasts are more susceptible to an induced oxidative stress than control myoblasts. Moreover, we demonstrate that both types of FSHD primary myoblasts differentiate into multi-nucleated myotubes, which present morphological abnormalities. Whereas control myoblasts fuse to form branched myotubes with aligned nuclei, FSHD myoblasts fuse to form either thin and branched myotubes with aligned nuclei or large myotubes with random nuclei distribution. In conclusion, we postulate that these abnormalities could be responsible for muscle weakness in patients with FSHD and provide an important marker for FSHD myoblasts. PMID:18505476

  13. Morphological study and comprehensive cellular constituents of milky spots in the human omentum

    PubMed Central

    Liu, Jiu-Yang; Yuan, Jing-Ping; Geng, Xia-Fei; Qu, Ai-Ping; Li, Yan

    2015-01-01

    Objective: To analyze morphological features of omental milky spots (MS). Method: Hematoxylin-eosin staining and immunohistochemistry technique were used to study the omental MS of gastric cancer (GC) patients and rectal cancer (RC) patients. We focused on morphological features of MS and conducted quantitative analysis on the cells number and cellular constituents. Differences in MS parameters between GC and RC were also analyzed. Results: Various shapes of MS were mainly round, oval, irregular form in the adipose and perivascular annular. The median MS perimeter was 2752 (range 817~7753) computer-based pixels. The median value of immune cells in one MS was 141 (43~650), comprising T lymphocytes (46.1%), B lymphocytes (28.4%), macrophages (12.4%) and other immune cells (13.1%). Relatively high density of vessels in MS could be calculated by micro-vessel density (MVD) as 4 (0~13). The median value of mesothelial cells loosely arranged in the surface layer was 5 (0~51). There were no significant differences in MS perimeter, MVD, the number of mesothelial cells, total immune cells, T lymphocytes and macrophages between GC and RC (P>0.05), while the number of MS B lymphocytes in RC was significantly higher than that in GC (P<0.001). Conclusion: MS are primary immune tissues in the omentum and structural bases for development and progression of peritoneal dissemination of GC and RC. Analyzing the morphology and cellular constituents could help understanding the mechanism of peritoneal metastasis. PMID:26722479

  14. Effects of temperature and cellular interactions on the mechanics and morphology of human cancer cells investigated by atomic force microscopy.

    PubMed

    Li, Mi; Liu, LianQing; Xi, Ning; Wang, YueChao; Xiao, XiuBin; Zhang, WeiJing

    2015-09-01

    Cell mechanics plays an important role in cellular physiological activities. Recent studies have shown that cellular mechanical properties are novel biomarkers for indicating the cell states. In this article, temperature-controllable atomic force microscopy (AFM) was applied to quantitatively investigate the effects of temperature and cellular interactions on the mechanics and morphology of human cancer cells. First, AFM indenting experiments were performed on six types of human cells to investigate the changes of cellular Young's modulus at different temperatures and the results showed that the mechanical responses to the changes of temperature were variable for different types of cancer cells. Second, AFM imaging experiments were performed to observe the morphological changes in living cells at different temperatures and the results showed the significant changes of cell morphology caused by the alterations of temperature. Finally, by co-culturing human cancer cells with human immune cells, the mechanical and morphological changes in cancer cells were investigated. The results showed that the co-culture of cancer cells and immune cells could cause the distinct mechanical changes in cancer cells, but no significant morphological differences were observed. The experimental results improved our understanding of the effects of temperature and cellular interactions on the mechanics and morphology of cancer cells. PMID:26354505

  15. Directional Solidification of a Binary Alloy into a Cellular Convective Flow: Localized Morphologies

    NASA Technical Reports Server (NTRS)

    Chen, Y.- J.; Davis, S. H.

    1999-01-01

    A steady, two dimensional cellular convection modifies the morphological instability of a binary alloy that undergoes directional solidification. When the convection wavelength is far longer than that of the morphological cells, the behavior of the moving front is described by a slow, spatial-temporal dynamics obtained through a multiple-scale analysis. The resulting system has a "parametric-excitation" structure in space, with complex parameters characterizing the interactions between flow, solute diffusion, and rejection. The convection stabilizes two dimensional disturbances oriented with the flow, but destabilizes three dimensional disturbances in general. When the flow is weak, the morphological instability behaves incommensurably to the flow wavelength, but becomes quantized and forced to fit into the flow-box as the flow gets stronger. At large flow magnitudes the instability is localized, confined in narrow envelopes with cells traveling with the flow. In this case the solutions are discrete eigenstates in an unbounded space. Their stability boundary and asymptotics are obtained by the WKB analysis.

  16. An analytical tool that quantifies cellular morphology changes from three-dimensional fluorescence images.

    PubMed

    Haass-Koffler, Carolina L; Naeemuddin, Mohammad; Bartlett, Selena E

    2012-01-01

    The most common software analysis tools available for measuring fluorescence images are for two-dimensional (2D) data that rely on manual settings for inclusion and exclusion of data points, and computer-aided pattern recognition to support the interpretation and findings of the analysis. It has become increasingly important to be able to measure fluorescence images constructed from three-dimensional (3D) datasets in order to be able to capture the complexity of cellular dynamics and understand the basis of cellular plasticity within biological systems. Sophisticated microscopy instruments have permitted the visualization of 3D fluorescence images through the acquisition of multispectral fluorescence images and powerful analytical software that reconstructs the images from confocal stacks that then provide a 3D representation of the collected 2D images. Advanced design-based stereology methods have progressed from the approximation and assumptions of the original model-based stereology even in complex tissue sections. Despite these scientific advances in microscopy, a need remains for an automated analytic method that fully exploits the intrinsic 3D data to allow for the analysis and quantification of the complex changes in cell morphology, protein localization and receptor trafficking. Current techniques available to quantify fluorescence images include Meta-Morph (Molecular Devices, Sunnyvale, CA) and Image J (NIH) which provide manual analysis. Imaris (Andor Technology, Belfast, Northern Ireland) software provides the feature MeasurementPro, which allows the manual creation of measurement points that can be placed in a volume image or drawn on a series of 2D slices to create a 3D object. This method is useful for single-click point measurements to measure a line distance between two objects or to create a polygon that encloses a region of interest, but it is difficult to apply to complex cellular network structures. Filament Tracer (Andor) allows automatic

  17. Effect of crystals and fibrous network polymer additives on cellular morphology of microcellular foams

    NASA Astrophysics Data System (ADS)

    Miyamoto, Ryoma; Utano, Tatsumi; Yasuhara, Shunya; Ishihara, Shota; Ohshima, Masahiro

    2015-05-01

    In this study, the core-back foam injection molding was used for preparing microcelluar polypropylene (PP) foam with either a 1,3:2,4 bis-O-(4-methylbenzylidene)-D-sorbitol gelling agent (Gel-all MD) or a fibros network polymer additive (Metablen 3000). Both agent and addiive could effectively control the celluar morphology in foams but somehow different ways. In course of cooling the polymer with Gel-all MD in the mold caity, the agent enhanced the crystal nucleation and resulted in the large number of small crystals. The crystals acted as effective bubble nucleation agent in foaming process. Thus, the agent reduced the cell size and increased the cell density, drastically. Furthermore, the small crystals provided an inhomogenuity to the expanding cell wall and produced the high open cell content with nano-scale fibril structure. Gell-all as well as Metablene 3000 formed a gel-like fibrous network in melt. The network increased the elongational viscosity and tended to prevent the cell wall from breaking up. The foaming temperature window was widened by the presence of the network. Especially, the temperature window where the macro-fibrous structure was formed was expanded to the higher temperature. The effects of crystal nucleating agent and PTFE on crystals' size and number, viscoelsticity, rheological propreties of PP and cellular morphology were compared and thorougly investigated.

  18. How Word Frequency Affects Morphological Processing in Monolinguals and Bilinguals

    ERIC Educational Resources Information Center

    Lehtonen, Minna; Laine, Matti

    2003-01-01

    The present study investigated processing of morphologically complex words in three different frequency ranges in monolingual Finnish speakers and Finnish-Swedish bilinguals. By employing a visual lexical decision task, we found a differential pattern of results in monolinguals vs. bilinguals. Monolingual Finns seemed to process low frequency and…

  19. Factors Affecting the Acquisition of Plural Morphology in Jordanian Arabic

    ERIC Educational Resources Information Center

    Albirini, Abdulkafi

    2015-01-01

    This study investigates the development of plural morphology in Jordanian Arab children, and explores the role of the predictability, transparency, productivity, and frequency of different plural forms in determining the trajectory that children follow in acquiring this complex inflectional system. The study also re-examines the development of the…

  20. Hypergravity Loading the Cultured Osteoblasts: Modeling and Experimental Analysis of Cellular Morphology and the Cytoskeleton

    NASA Technical Reports Server (NTRS)

    Searby, N. D.; Steele, C. R.; Globus, R. K.; Dalton, Bonnie P. (Technical Monitor)

    2001-01-01

    Bone forming cells, osteoblasts, respond to various mechanical forces, including mechanical strain and fluid-induced shear stress. This study examined whether osteoblasts detect changes in gravity as a mechanical force, as assessed by cellular morphology and dimensions of the cytoskeletal network. We used modeling to evaluate how gravity influences cell morphology given theoretical differences in densities between the surrounding medium, cytoplasm, and nucleus. A mechanical model was built based on analysis of axisymmetric shell structures (Fast4 software) to study the effects of 10 times gravity (10G) on cell height. The model indicated 0.02% decrease in overall cell height when the medium was 10% denser than the nucleus or cytoplasm, 5.9 x 10(exp-5)% decrease when the nucleus was 10% denser than the cytoplasm or medium, and 1.3 x 10(exp-5)% decrease when the cell cytoplasm was 10% denser than the nucleus or medium. To experimentally evaluate the influence of gravity, cultured primary fetal rat osteoblasts were grown to near confluence and centrifuged at 10G for 3 hours. Actin, microtubules, and nuclei were fluorescently labeled and analyzed by confocal microscopy to determine overall microtubule and actin network height. Centrifugation led to an apparent reduction in height of both the microtubule (-16%) and the actin (-20%) networks relative to stationary controls. Thus, both modeling and experiments indicate that hypergravity reduces the height of the osteoblast cell layer and their microtubule and actin networks. This combination of modeling and experimental analyses will help us to better understand the mechanical loading of osteoblasts.

  1. Clinorotation affects morphology and ethylene production in soybean seedlings

    NASA Technical Reports Server (NTRS)

    Hilaire, E.; Peterson, B. V.; Guikema, J. A.; Brown, C. S.; Sager, J. C. (Principal Investigator)

    1996-01-01

    The microgravity environment of spaceflight influences growth, morphology and metabolism in etiolated germinating soybean. To determine if clinorotation will similarly impact these processes, we conducted ground-based studies in conjunction with two space experiment opportunities. Soybean (Glycine max [L.] Merr.) seeds were planted within BRIC (Biological Research In Canister) canisters and grown for seven days at 20 degrees C under clinorotation (1 rpm) conditions or in a stationary upright mode. Gas samples were taken daily and plants were harvested after seven days for measurement of growth and morphology. Compared to the stationary upright controls, plants exposed to clinorotation exhibited increased root length (125% greater) and fresh weight (42% greater), whereas shoot length and fresh weight decreased by 33% and 16% respectively. Plants grown under clinorotation produced twice as much ethylene as the stationary controls. Seedlings treated with triiodo benzoic acid (TIBA), an auxin transport inhibitor, under clinorotation produced 50% less ethylene than the untreated control subjected to the same gravity treatment, whereas a treatment with 2,4-D increased ethylene by five-fold in the clinorotated plants. These data suggest that slow clinorotation influences biomass partitioning and ethylene production in etiolated soybean plants.

  2. Tunable Cosolvent Annealing Affects on Block Copolymer Morphology

    NASA Astrophysics Data System (ADS)

    Gotrik, Kevin; Son, Jeong Gon; Hannon, Adam; Alexander-Katz, Alfredo; Ross, Caroline

    2011-03-01

    Being able to precisely and reproducibly control block copolymer (BCP) morphology is of interest for lithographic applications due to the techniques ability to result in feature sizes ranging from 10-100nm. We explore the morphological phase behavior that thin films (30-40nm) of poly(styrene-b-dimethylsiloxane) (PS-PDMS, 45kg/mol, ~ 0.26 segmental Flory-Huggins interaction parameter) exhibit under different cosolvent vapors of toluene and heptane. Variation in the solvent conditions results in selective swelling of the different blocks of the copolymer depending on relative Hildebrand solubility parameters (e.g. PS- 18.5, toluene-18.3 (MPa)1/2) resulting in cylinders, spheres, lamella, and perforatted lamella self-assembled features which can be revealed by selectively etching the PS with an oxygen plasma (50W CF4). Here we describe precision solvent vapor control while doing in situ spectral reflectometry (230-1500nm) to track swelling of the BCP films as a function of time to gain insight into this BCP system.

  3. Factors affecting the acquisition of plural morphology in Jordanian Arabic.

    PubMed

    Albirini, Abdulkafi

    2015-07-01

    This study investigates the development of plural morphology in Jordanian Arab children, and explores the role of the predictability, transparency, productivity, and frequency of different plural forms in determining the trajectory that children follow in acquiring this complex inflectional system. The study also re-examines the development of the notion of default over several years. Sixty Jordanian children, equally divided among six age groups (three to eight years), completed an oral real-word pluralization task and a nonsense-word pluralization task. The findings indicate that feminine sound plurals are acquired before and extended to the other plural forms. Productivity and frequency seem to shape the acquisition patterns among younger children, but predictability becomes more critical at a later age. Younger children use the most productive plural as the default form, but older children tend to use two default forms based on frequency distributions in the adult language. The theoretical implications of the findings are discussed. PMID:25158792

  4. How Morphology Affects Singlet Fission in Crystalline Tetracene.

    PubMed

    Piland, Geoffrey B; Bardeen, Christopher J

    2015-05-21

    The dependence of exciton dynamics on the crystalline morphology of tetracene is investigated using time-resolved photoluminescence. Single crystals exhibit relatively slow singlet decays with times that range from 130 to 300 ps depending on the sample. This decay has an activation energy of ∼450 cm(-1) over the temperature range of 200-400 K. Single-crystal samples also exhibit more pronounced quantum beats due to the triplet pair spin coherences. Polycrystalline thin films grown by thermal evaporation have singlet decay times on the order of 70-90 ps with a much weaker temperature dependence. Many thin-film samples also exhibit a red-shifted excimer-like emission. When a polycrystalline thin film is thermally annealed to produce larger crystal domains, single-crystal behavior is recovered. We hypothesize that the different dynamics arise from the ability of singlet excitons in the thin films to sample regions with defects or packing motifs that accelerate singlet fission. PMID:26263258

  5. Habitat use affects morphological diversification in dragon lizards

    PubMed Central

    COLLAR, D C; SCHULTE, J A; O’MEARA, B C; LOSOS, J B

    2010-01-01

    Habitat use may lead to variation in diversity among evolutionary lineages because habitats differ in the variety of ways they allow for species to make a living. Here, we show that structural habitats contribute to differential diversification of limb and body form in dragon lizards (Agamidae). Based on phylogenetic analysis and ancestral state reconstructions for 90 species, we find that multiple lineages have independently adopted each of four habitat use types: rock-dwelling, terrestriality, semi-arboreality and arboreality. Given these reconstructions, we fit models of evolution to species’ morphological trait values and find that rock-dwelling and arboreality limit diversification relative to terrestriality and semi-arboreality. Models preferred by Akaike information criterion infer slower rates of size and shape evolution in lineages inferred to occupy rocks and trees, and model-averaged rate estimates are slowest for these habitat types. These results suggest that ground-dwelling facilitates ecomorphological differentiation and that use of trees or rocks impedes diversification. PMID:20345808

  6. Carbon availability affects diurnally controlled processes and cell morphology of Cyanothece 51142.

    PubMed

    Stöckel, Jana; Elvitigala, Thanura R; Liberton, Michelle; Pakrasi, Himadri B

    2013-01-01

    Cyanobacteria are oxygenic photoautotrophs notable for their ability to utilize atmospheric CO2 as the major source of carbon. The prospect of using cyanobacteria to convert solar energy and high concentrations of CO2 efficiently into biomass and renewable energy sources has sparked substantial interest in using flue gas from coal-burning power plants as a source of inorganic carbon. However, in order to guide further advances in this area, a better understanding of the metabolic changes that occur under conditions of high CO2 is needed. To determine the effect of high CO2 on cell physiology and growth, we analyzed the global transcriptional changes in the unicellular diazotrophic cyanobacterium Cyanothece 51142 grown in 8% CO2-enriched air. We found a concerted response of genes related to photosynthesis, carbon metabolism, respiration, nitrogen fixation, ribosome biosynthesis, and the synthesis of nucleotides and structural cell wall polysaccharides. The overall response to 8% CO2 in Cyanothece 51142 involves different strategies, to compensate for the high C/N ratio during both phases of the diurnal cycle. Our analyses show that high CO2 conditions trigger the production of carbon-rich compounds and stimulate processes such as respiration and nitrogen fixation. In addition, we observed that high levels of CO2 affect fundamental cellular processes such as cell growth and dramatically alter the intracellular morphology. This study provides novel insights on how diurnal and developmental rhythms are integrated to facilitate adaptation to high CO2 in Cyanothece 51142. PMID:23457634

  7. Carbon Availability Affects Diurnally Controlled Processes and Cell Morphology of Cyanothece 51142

    PubMed Central

    Stöckel, Jana; Elvitigala, Thanura R.; Liberton, Michelle; Pakrasi, Himadri B.

    2013-01-01

    Cyanobacteria are oxygenic photoautotrophs notable for their ability to utilize atmospheric CO2 as the major source of carbon. The prospect of using cyanobacteria to convert solar energy and high concentrations of CO2 efficiently into biomass and renewable energy sources has sparked substantial interest in using flue gas from coal-burning power plants as a source of inorganic carbon. However, in order to guide further advances in this area, a better understanding of the metabolic changes that occur under conditions of high CO2 is needed. To determine the effect of high CO2 on cell physiology and growth, we analyzed the global transcriptional changes in the unicellular diazotrophic cyanobacterium Cyanothece 51142 grown in 8% CO2-enriched air. We found a concerted response of genes related to photosynthesis, carbon metabolism, respiration, nitrogen fixation, ribosome biosynthesis, and the synthesis of nucleotides and structural cell wall polysaccharides. The overall response to 8% CO2 in Cyanothece 51142 involves different strategies, to compensate for the high C/N ratio during both phases of the diurnal cycle. Our analyses show that high CO2 conditions trigger the production of carbon-rich compounds and stimulate processes such as respiration and nitrogen fixation. In addition, we observed that high levels of CO2 affect fundamental cellular processes such as cell growth and dramatically alter the intracellular morphology. This study provides novel insights on how diurnal and developmental rhythms are integrated to facilitate adaptation to high CO2 in Cyanothece 51142. PMID:23457634

  8. Three-dimensional morphology and gene expression in the Drosophila blastoderm at cellular resolution I: data acquisition pipeline

    PubMed Central

    Luengo Hendriks, Cris L; Keränen, Soile VE; Fowlkes, Charless C; Simirenko, Lisa; Weber, Gunther H; DePace, Angela H; Henriquez, Clara; Kaszuba, David W; Hamann, Bernd; Eisen, Michael B; Malik, Jitendra; Sudar, Damir; Biggin, Mark D; Knowles, David W

    2006-01-01

    Background To model and thoroughly understand animal transcription networks, it is essential to derive accurate spatial and temporal descriptions of developing gene expression patterns with cellular resolution. Results Here we describe a suite of methods that provide the first quantitative three-dimensional description of gene expression and morphology at cellular resolution in whole embryos. A database containing information derived from 1,282 embryos is released that describes the mRNA expression of 22 genes at multiple time points in the Drosophila blastoderm. We demonstrate that our methods are sufficiently accurate to detect previously undescribed features of morphology and gene expression. The cellular blastoderm is shown to have an intricate morphology of nuclear density patterns and apical/basal displacements that correlate with later well-known morphological features. Pair rule gene expression stripes, generally considered to specify patterning only along the anterior/posterior body axis, are shown to have complex changes in stripe location, stripe curvature, and expression level along the dorsal/ventral axis. Pair rule genes are also found to not always maintain the same register to each other. Conclusion The application of these quantitative methods to other developmental systems will likely reveal many other previously unknown features and provide a more rigorous understanding of developmental regulatory networks. PMID:17184546

  9. Lung damage induced by butylated hydroxytoluene in mice. Biochemical, cellular, and morphologic characterization.

    PubMed

    Smith, L J

    1984-11-01

    This study was designed to characterize the biochemical, cellular, and morphologic events produced in mice by butylated hydroxytoluene (BHT) and to relate these events to changes in extracellular angiotensin-converting enzyme (ACE) activity. On Day 1 after the administration of BHT, bronchoalveolar lavage (BAL) ACE activity increased 4-fold (p less than 0.001), its specific activity relative to BAL protein increased 3-fold (p less than 0.001), and both type 1 cell damage and endothelial cell damage were detected by electron microscopy. The early increase in BAL ACE activity preceded changes in plasma ACE levels, BAL cell number, protein, lactate, and lactate dehydrogenase (LDH) activity in both plasma and BAL, and the ACE content of alveolar macrophages. On Day 2, BAL ACE activity increased 9-fold, BAL protein increased 4-fold (p less than 0.001), BAL LDH activity increased 34% (p less than 0.05), and the BAL cell count doubled (p less than 0.01). Changes in each animal's appearance, body weight, wet and dry lung weights, and plasma ACE levels occurred between Days 3 and 5. The BAL differential cell count, which consisted of greater than 95% macrophages in uninjured mice, did not change until Day 5 when there was a small increase in polymorphonuclear leukocytes (PMN). On Day 7, the number of PMN peaked, and some of the other measures of lung injury began returning toward normal. These results indicate that BAL ACE activity is a sensitive, early marker of BHT-induced lung injury, which appears to reflect damage to the cells of the alveolar-capillary barrier. In addition, PMN do not appear to play a major role in this model of lung injury. Because of its effects on angiotensin, bradykinin, and prostaglandins, the early release of ACE from damaged cells may modulate the subsequent injury. PMID:6093659

  10. Autofluorescence multiphoton microscopy for visualization of tissue morphology and cellular dynamics in murine and human airways

    PubMed Central

    Kretschmer, Sarah; Pieper, Mario; Hüttmann, Gereon; Bölke, Torsten; Wollenberg, Barbara; Marsh, Leigh M; Garn, Holger; König, Peter

    2016-01-01

    The basic understanding of inflammatory airway diseases greatly benefits from imaging the cellular dynamics of immune cells. Current imaging approaches focus on labeling specific cells to follow their dynamics but fail to visualize the surrounding tissue. To overcome this problem, we evaluated autofluorescence multiphoton microscopy for following the motion and interaction of cells in the airways in the context of tissue morphology. Freshly isolated murine tracheae from healthy mice and mice with experimental allergic airway inflammation were examined by autofluorescence multiphoton microscopy. In addition, fluorescently labeled ovalbumin and fluorophore-labeled antibodies were applied to visualize antigen uptake and to identify specific cell populations, respectively. The trachea in living mice was imaged to verify that the ex vivo preparation reflects the in vivo situation. Autofluorescence multiphoton microscopy was also tested to examine human tissue from patients in short-term tissue culture. Using autofluorescence, the epithelium, underlying cells, and fibers of the connective tissue, as well as blood vessels, were identified in isolated tracheae. Similar structures were visualized in living mice and in the human airway tissue. In explanted murine airways, mobile cells were localized within the tissue and we could follow their migration, interactions between individual cells, and their phagocytic activity. During allergic airway inflammation, increased number of eosinophil and neutrophil granulocytes were detected that moved within the connective tissue and immediately below the epithelium without damaging the epithelial cells or connective tissues. Contacts between granulocytes were transient lasting 3 min on average. Unexpectedly, prolonged interactions between granulocytes and antigen-uptaking cells were observed lasting for an average of 13 min. Our results indicate that autofluorescence-based imaging can detect previously unknown immune cell

  11. Autofluorescence multiphoton microscopy for visualization of tissue morphology and cellular dynamics in murine and human airways.

    PubMed

    Kretschmer, Sarah; Pieper, Mario; Hüttmann, Gereon; Bölke, Torsten; Wollenberg, Barbara; Marsh, Leigh M; Garn, Holger; König, Peter

    2016-08-01

    The basic understanding of inflammatory airway diseases greatly benefits from imaging the cellular dynamics of immune cells. Current imaging approaches focus on labeling specific cells to follow their dynamics but fail to visualize the surrounding tissue. To overcome this problem, we evaluated autofluorescence multiphoton microscopy for following the motion and interaction of cells in the airways in the context of tissue morphology. Freshly isolated murine tracheae from healthy mice and mice with experimental allergic airway inflammation were examined by autofluorescence multiphoton microscopy. In addition, fluorescently labeled ovalbumin and fluorophore-labeled antibodies were applied to visualize antigen uptake and to identify specific cell populations, respectively. The trachea in living mice was imaged to verify that the ex vivo preparation reflects the in vivo situation. Autofluorescence multiphoton microscopy was also tested to examine human tissue from patients in short-term tissue culture. Using autofluorescence, the epithelium, underlying cells, and fibers of the connective tissue, as well as blood vessels, were identified in isolated tracheae. Similar structures were visualized in living mice and in the human airway tissue. In explanted murine airways, mobile cells were localized within the tissue and we could follow their migration, interactions between individual cells, and their phagocytic activity. During allergic airway inflammation, increased number of eosinophil and neutrophil granulocytes were detected that moved within the connective tissue and immediately below the epithelium without damaging the epithelial cells or connective tissues. Contacts between granulocytes were transient lasting 3 min on average. Unexpectedly, prolonged interactions between granulocytes and antigen-uptaking cells were observed lasting for an average of 13 min. Our results indicate that autofluorescence-based imaging can detect previously unknown immune cell

  12. Reverse Signaling by Semaphorin-6A Regulates Cellular Aggregation and Neuronal Morphology

    PubMed Central

    Perez-Branguli, Francesc; Zagar, Yvrick; Shanley, Daniel K.; Graef, Isabella A.; Chédotal, Alain; Mitchell, Kevin J.

    2016-01-01

    The transmembrane semaphorin, Sema6A, has important roles in axon guidance, cell migration and neuronal connectivity in multiple regions of the nervous system, mediated by context-dependent interactions with plexin receptors, PlxnA2 and PlxnA4. Here, we demonstrate that Sema6A can also signal cell-autonomously, in two modes, constitutively, or in response to higher-order clustering mediated by either PlxnA2-binding or chemically induced multimerisation. Sema6A activation stimulates recruitment of Abl to the cytoplasmic domain of Sema6A and phos¡phorylation of this cytoplasmic tyrosine kinase, as well as phosphorylation of additional cytoskeletal regulators. Sema6A reverse signaling affects the surface area and cellular complexity of non-neuronal cells and aggregation and neurite formation of primary neurons in vitro. Sema6A also interacts with PlxnA2 in cis, which reduces binding by PlxnA2 of Sema6A in trans but not vice versa. These experiments reveal the complex nature of Sema6A biochemical functions and the molecular logic of the context-dependent interactions between Sema6A and PlxnA2. PMID:27392094

  13. Identification of multiple cellular uptake pathways of polystyrene nanoparticles and factors affecting the uptake: relevance for drug delivery systems.

    PubMed

    Firdessa, Rebuma; Oelschlaeger, Tobias A; Moll, Heidrun

    2014-01-01

    Nanoparticles may address challenges by human diseases through improving diagnosis, vaccination and treatment. The uptake mechanism regulates the type of threat a particle poses on the host cells and how a cell responds to it. Hence, understanding the uptake mechanisms and cellular interactions of nanoparticles at the cellular and subcellular level is a prerequisite for their effective biomedical applications. The present study shows the uptake mechanisms of polystyrene nanoparticles and factors affecting their uptake in bone marrow-derived macrophages, 293T kidney epithelial cells and L929 fibroblasts. Labeling with the endocytic marker FM4-64 and transmission electron microscopy studies show that the nanoparticles were internalized rapidly via endocytosis and accumulated in intracellular vesicles. Soon after their internalizations, nanoparticles trafficked to organelles with acidic pH. Analysis of the ultrastructural morphology of the plasma membrane invaginations or extravasations provides clear evidence for the involvement of several uptake routes in parallel to internalize a given type of nanoparticles by mammalian cells, highlighting the complexity of the nanoparticle-cell interactions. Blocking the specific endocytic pathways by different pharmacological inhibitors shows similar outcomes. The potential to take up nanoparticles varies highly among different cell types in a particle sizes-, time- and energy-dependent manner. Furthermore, infection and the activation status of bone marrow-derived macrophages significantly affect the uptake potential of the cells, indicating the need to understand the diseases' pathogenesis to establish effective and rational drug-delivery systems. This study enhances our understanding of the application of nanotechnology in biomedical sciences. PMID:25224362

  14. Effect of wavelength and fluence on morphology, cellular and genetic integrity of diabetic wounded human skin fibroblasts

    NASA Astrophysics Data System (ADS)

    Abrahamse, H.; Hawkins, D.; Houreld, N.

    2006-02-01

    An alternative treatment modality for diabetic wound healing includes low level laser therapy (LLLT). Biostimulation of such wounds may be of benefit to patients by reducing healing time. Structural, cellular and genetic events in diabetic wounded human skin fibroblasts (WS1) were evaluated after exposing cells in culture to a Helium-Neon (632.8nm), a Diode laser (830nm) and a Nd:YAG (Neodynium:Yttrium-Allumina-Gallium) laser (1064nm) at either 5J/cm2 or 16J/cm2. Cells were exposed twice a week and left 24 hours post-irradiation prior to measuring effects. Structural changes were evaluated by assessing colony formation, haptotaxis and chemotaxis. Cellular changes were evaluated using cell viability, (adenosine-triphosphate, ATP production), and proliferation, (alkaline phosphatase, ALP and basic fibroblast growth factor, bFGF expression), while the Comet assay evaluated DNA damage and cytotoxicity was determined assessing membrane permeability for lactate dehydrogenase (LDH). Caspase 3/7 activity was used as an estimate of apoptosis as a result of irradiation. The irradiated diabetic wounded cells showed structural, cellular as well as molecular resilience comparable to that of unwounded normal skin fibroblast cells. With regards to fluence, 5J/cm2 elicit positive cellular and structural responses while 16J/cm2 increases cellular and genetic damage and cellular morphology is altered. Different wavelengths of LLLT influences the beneficial outcomes of diabetic wounded cells and although all three wavelengths elicit cellular effects, the penetration depth of 830nm plays a significant role in the healing of diabetic wounded human fibroblast cells. Results from this study validate the contribution of LLLT to wound healing and elucidate the biochemical effects at a cellular level while highlighting the role of different dosages and wavelengths in LLLT.

  15. Titanium dioxide nanoparticles alter cellular morphology via disturbing the microtubule dynamics

    NASA Astrophysics Data System (ADS)

    Mao, Zhilei; Xu, Bo; Ji, Xiaoli; Zhou, Kun; Zhang, Xuemei; Chen, Minjian; Han, Xiumei; Tang, Qiusha; Wang, Xinru; Xia, Yankai

    2015-04-01

    Titanium dioxide (TiO2) nanoparticles (NPs) have been widely used in our daily lives, for example, in the areas of sunscreens, cosmetics, toothpastes, food products, and nanomedical reagents. Recently, increasing concern has been raised about their neurotoxicity, but the mechanisms underlying such toxic effects are still unknown. In this work, we employed a human neuroblastoma cell line (SH-SY5Y) to study the effects of TiO2 NPs on neurological systems. Our results showed that TiO2 NPs did not affect cell viability but induced noticeable morphological changes until 100 μg ml-1. Immunofluorescence detection showed disorder, disruption, retraction, and decreased intensity of the microtubules after TiO2 NPs treatment. Both α and β tubule expressions did not change in the TiO2 NP-treated group, but the percentage of soluble tubules was increased. A microtubule dynamic study in living cells indicated that TiO2 NPs caused a lower growth rate and a higher shortening rate of microtubules as well as shortened lifetimes of de novo microtubules. TiO2 NPs did not cause changes in the expression and phosphorylation state of tau proteins, but a tau-TiO2 NP interaction was observed. TiO2 NPs could interact with tubule heterodimers, microtubules and tau proteins, which led to the instability of microtubules, thus contributing to the neurotoxicity of TiO2 NPs.Titanium dioxide (TiO2) nanoparticles (NPs) have been widely used in our daily lives, for example, in the areas of sunscreens, cosmetics, toothpastes, food products, and nanomedical reagents. Recently, increasing concern has been raised about their neurotoxicity, but the mechanisms underlying such toxic effects are still unknown. In this work, we employed a human neuroblastoma cell line (SH-SY5Y) to study the effects of TiO2 NPs on neurological systems. Our results showed that TiO2 NPs did not affect cell viability but induced noticeable morphological changes until 100 μg ml-1. Immunofluorescence detection showed disorder

  16. Osmotic tolerance of in vitro produced porcine blastocysts assessed by their morphological integrity and cellular actin filament organization.

    PubMed

    Men, Hongsheng; Agca, Yuksel; Mullen, Steven F; Critser, Elizabeth S; Critser, John K

    2005-10-01

    This experiment investigated the osmotic tolerance limits of the morphology and the cellular actin filament organization of porcine blastocysts. In vitro produced Day 6 blastocysts were subjected to osmotic treatments with sucrose solutions of different osmolalities (75, 150, 210, 600, 1200, and 2400 mOsm) and one isotonic solution (NCSU-23, 285 mOsm). Blastocysts were then either fixed immediately, or cultured for 18 h and subsequently fixed with formalin. The morphology of the treated blastocysts was examined under a stereomicroscope and the integrity of the cellular actin filaments of the blastocysts was examined by confocal microscopy after staining with Alexa Fluor 488 phalloidin. The results indicated that there was a significant relationship between the osmotic levels and the probability of blastocysts exhibiting disrupted cellular actin filaments. In addition, blastocysts also collapsed in proportion to the levels of osmotic treatments. The osmotic tolerance limits which would maintain 70% of the blastocysts with their original morphology immediately after the treatment were 90 and 170%, respectively, of isotonicity. After 18 h of culture, the osmotic tolerance limits were 61 and 163%, respectively, of isotonicity. Similarly, the osmotic conditions relative to isotonicity which would maintain the integrity of cellular actin filaments in 70% of treated blastocysts had to be within the range of 87 and 147% immediately after the treatment and 87 and 169% after 18 h of culture. Collectively, these data indicate that in vitro produced porcine blastocysts are very sensitive to osmotic stress. This information can be used to optimize cryopreservation procedures for porcine embryos. PMID:16024011

  17. Contaminant loading in remote Arctic lakes affects cellular stress-related proteins expression in feral charr.

    USGS Publications Warehouse

    Wiseman, Steve; Jorgensen, Even H.; Maule, Alec G.; Vijayan, Mathilakath M.

    2011-01-01

    The remote Arctic lakes on Bjornoya Island, Norway, offer a unique opportunity to study possible affect of lifelong contaminant exposure in wild populations of landlocked Arctic charr (Salvelinus alpinus). This is because Lake Ellasjoen has persistent organic pollutant (POP) levels that are significantly greater than in the nearby Lake Oyangen. We examined whether this differential contaminant loading was reflected in the expression of protein markers of exposure and effect in the native fish. We assessed the expressions of cellular stress markers, including cytochrome P4501A (Cyp1A), heat shock protein 70 (hsp70), and glucocorticoid receptor (GR) in feral charr from the two lakes. The average polychlorinated biphenyl (PCB) load in the charr liver from Ellasjoen was approximately 25-fold higher than in individuals from Oyangen. Liver Cyp1A protein expression was significantly higher in individuals from Ellasjoen compared with Oyangen, confirming differential PCB exposure. There was no significant difference in hsp70 protein expression in charr liver between the two lakes. However, brain hsp70 protein expression was significantly elevated in charr from Ellasjoen compared with Oyangen. Also, liver GR protein expression was significantly higher in the Ellasjoen charr compared with Oyangen charr. Taken together, our results suggest changes to cellular stress-related protein expression as a possible adaptation to chronic-contaminant exposure in feral charr in the Norwegian high-Arctic.

  18. Morphology of Filamentous Fungi: Linking Cellular Biology to Process Engineering Using Aspergillus niger

    NASA Astrophysics Data System (ADS)

    Krull, Rainer; Cordes, Christiana; Horn, Harald; Kampen, Ingo; Kwade, Arno; Neu, Thomas R.; Nörtemann, Bernd

    In various biotechnological processes, filamentous fungi, e.g. Aspergillus niger, are widely applied for the production of high value-added products due to their secretion efficiency. There is, however, a tangled relationship between the morphology of these microorganisms, the transport phenomena and the related productivity. The morphological characteristics vary between freely dispersed mycelia and distinct pellets of aggregated biomass. Hence, advantages and disadvantages for mycel or pellet cultivation have to be balanced out carefully. Due to this inadequate understanding of morphogenesis of filamentous microorganisms, fungal morphology, along with reproducibility of inocula of the same quality, is often a bottleneck of productivity in industrial production. To obtain an optimisation of the production process it is of great importance to gain a better understanding of the molecular and cell biology of these microorganisms as well as the approaches in biochemical engineering and particle technique, in particular to characterise the interactions between the growth conditions, cell morphology, spore-hyphae-interactions and product formation. Advances in particle and image analysis techniques as well as micromechanical devices and their applications to fungal cultivations have made available quantitative morphological data on filamentous cells. This chapter provides the ambitious aspects of this line of action, focussing on the control and characterisation of the morphology, the transport gradients and the approaches to understand the metabolism of filamentous fungi. Based on these data, bottlenecks in the morphogenesis of A. niger within the complex production pathways from gene to product should be identified and this may improve the production yield.

  19. In situ CUTANEOUS CELLULAR IMMUNE RESPONSE IN DOGS NATURALLY AFFECTED BY VISCERAL LEISHMANIASIS

    PubMed Central

    ROSSI, Claudio Nazaretian; TOMOKANE, Thaise Yumie; BATISTA, Luis Fábio da Silva; MARCONDES, Mary; LARSSON, Carlos Eduardo; LAURENTI, Márcia Dalastra

    2016-01-01

    SUMMARY Thirty-eight dogs naturally affected by visceral leishmaniasis were recruited in Araçatuba, São Paulo State, Brazil - an endemic area for visceral leishmaniasis. The animals were distributed into one of two groups, according to their clinical and laboratory features, as either symptomatic or asymptomatic dogs. Correlations between clinical features and inflammatory patterns, cellular immune responses, and parasitism in the macroscopically uninjured skin of the ear were investigated. Histological skin patterns were similar in both groups, and were generally characterized by a mild to intense inflammatory infiltrate in the dermis, mainly consisting of mononuclear cells. There was no difference in the number of parasites in the skin (amastigotes/mm²) between the two groups. Concerning the characterization of the cellular immune response, the number of positive inducible nitric oxide synthase (iNOS+) cells was higher in the dermis of symptomatic than in asymptomatic dogs (p = 0.0368). A positive correlation between parasite density and macrophages density (p = 0.031), CD4+ T-cells (p = 0.015), and CD8+ T-cells (p = 0.023) was observed. Furthermore, a positive correlation between density of iNOS+ cells and CD3+ T-cells (p = 0.005), CD4+ T-cells (p = 0.001), and CD8+ T-cells (p = 0.0001) was also found. The results showed the existence of a non-specific chronic inflammatory infiltrate in the dermis of dogs affected by visceral leishmaniasis, characterized by the presence of activated macrophages and T-lymphocytes, associated to cutaneous parasitism, independent of clinical status. PMID:27410908

  20. In situ CUTANEOUS CELLULAR IMMUNE RESPONSE IN DOGS NATURALLY AFFECTED BY VISCERAL LEISHMANIASIS.

    PubMed

    Rossi, Claudio Nazaretian; Tomokane, Thaise Yumie; Batista, Luis Fábio da Silva; Marcondes, Mary; Larsson, Carlos Eduardo; Laurenti, Márcia Dalastra

    2016-07-11

    Thirty-eight dogs naturally affected by visceral leishmaniasis were recruited in Araçatuba, São Paulo State, Brazil - an endemic area for visceral leishmaniasis. The animals were distributed into one of two groups, according to their clinical and laboratory features, as either symptomatic or asymptomatic dogs. Correlations between clinical features and inflammatory patterns, cellular immune responses, and parasitism in the macroscopically uninjured skin of the ear were investigated. Histological skin patterns were similar in both groups, and were generally characterized by a mild to intense inflammatory infiltrate in the dermis, mainly consisting of mononuclear cells. There was no difference in the number of parasites in the skin (amastigotes/mm²) between the two groups. Concerning the characterization of the cellular immune response, the number of positive inducible nitric oxide synthase (iNOS+) cells was higher in the dermis of symptomatic than in asymptomatic dogs (p = 0.0368). A positive correlation between parasite density and macrophages density (p = 0.031), CD4+ T-cells (p = 0.015), and CD8+ T-cells (p = 0.023) was observed. Furthermore, a positive correlation between density of iNOS+ cells and CD3+ T-cells (p = 0.005), CD4+ T-cells (p = 0.001), and CD8+ T-cells (p = 0.0001) was also found. The results showed the existence of a non-specific chronic inflammatory infiltrate in the dermis of dogs affected by visceral leishmaniasis, characterized by the presence of activated macrophages and T-lymphocytes, associated to cutaneous parasitism, independent of clinical status. PMID:27410908

  1. Fibrillarin, a nucleolar protein, is required for normal nuclear morphology and cellular growth in HeLa cells

    SciTech Connect

    Amin, Mohammed Abdullahel; Matsunaga, Sachihiro; Ma, Nan; Takata, Hideaki; Yokoyama, Masami; Uchiyama, Susumu; Fukui, Kiichi . E-mail: kfukui@bio.eng.osaka-u.ac.jp

    2007-08-24

    Fibrillarin is a key small nucleolar protein in eukaryotes, which has an important role in pre-rRNA processing during ribosomal biogenesis. Though several functions of fibrillarin are known, its function during the cell cycle is still unknown. In this study, we confirmed the dynamic localization of fibrillarin during the cell cycle of HeLa cells and also performed functional studies by using a combination of immunofluorescence microscopy and RNAi technique. We observed that depletion of fibrillarin has almost no effect on the nucleolar structure. However, fibrillarin-depleted cells showed abnormal nuclear morphology. Moreover, fibrillarin depletion resulted in the reduction of the cellular growth and modest accumulation of cells with 4n DNA content. Our data suggest that fibrillarin would play a critical role in the maintenance of nuclear shape and cellular growth.

  2. Neuronal Morphology goes Digital: A Research Hub for Cellular and System Neuroscience

    PubMed Central

    Parekh, Ruchi; Ascoli, Giorgio A.

    2013-01-01

    Summary The importance of neuronal morphology in brain function has been recognized for over a century. The broad applicability of “digital reconstructions” of neuron morphology across neuroscience sub-disciplines has stimulated the rapid development of numerous synergistic tools for data acquisition, anatomical analysis, three-dimensional rendering, electrophysiological simulation, growth models, and data sharing. Here we discuss the processes of histological labeling, microscopic imaging, and semi-automated tracing. Moreover, we provide an annotated compilation of currently available resources in this rich research “ecosystem” as a central reference for experimental and computational neuroscience. PMID:23522039

  3. Neuronal morphology goes digital: a research hub for cellular and system neuroscience.

    PubMed

    Parekh, Ruchi; Ascoli, Giorgio A

    2013-03-20

    The importance of neuronal morphology in brain function has been recognized for over a century. The broad applicability of "digital reconstructions" of neuron morphology across neuroscience subdisciplines has stimulated the rapid development of numerous synergistic tools for data acquisition, anatomical analysis, three-dimensional rendering, electrophysiological simulation, growth models, and data sharing. Here we discuss the processes of histological labeling, microscopic imaging, and semiautomated tracing. Moreover, we provide an annotated compilation of currently available resources in this rich research "ecosystem" as a central reference for experimental and computational neuroscience. PMID:23522039

  4. Association of p60src with Triton X-100-Resistant Cellular Structure Correlates with Morphological Transformation

    NASA Astrophysics Data System (ADS)

    Hamaguchi, Michinari; Hanafusa, Hidesaburo

    1987-04-01

    More than 70% of wild-type Rous sarcoma virus p60v-src was found to be associated with a cellular structure resistant to nonionic detergent extraction that consists primarily of cytoskeletal proteins. On the other hand, nontransforming src proteins, including cellular p60c-src, nonmyristoylated forms, and those inactive in protein kinase, were found in the fraction solubilized by the detergent extraction. p60c-src was detergent-soluble even in transformed cells, suggesting that the association of p60v-src is not a result of cell transformation. Analyses with a variety of Rous sarcoma virus mutants showed a good correlation between the degree of association with the detergent-resistant structure and the extent of cell transformation caused by mutant src proteins, suggesting that this association may be significant for the process of cell transformation by Rous sarcoma virus.

  5. How orthographic transparency affects morphological processing in young readers with and without reading disability.

    PubMed

    Lázaro, Miguel; García, Laura; Burani, Cristina

    2015-10-01

    This study investigates how orthographic modifications to the stems of complex words affect morphological processing in proficient young Spanish readers and children with reading deficits. In a definition task all children, irrespective of their reading skill, were worse at defining derived words that had an orthographic alteration of the base stem than words with no orthographic alteration. In a go/no-go lexical decision task, an interaction between base frequency and orthographic alteration was found: base frequency affected derived words with no orthographic alteration more than words with alterations, irrespective of reading skill. Overall, results show that all children benefit from a high frequency base, skilled children outperform children with reading deficits and morphological processing is affected by orthographic alterations similarly in proficient and impaired readers. PMID:25899060

  6. Reflectance spectroscopy with polarized light: is it sensitive to cellular and nuclear morphology

    NASA Astrophysics Data System (ADS)

    Sokolov, Konstantin; Drezek, Rebekah A.; Gossage, Kirk; Richards-Kortum, Rebecca R.

    1999-12-01

    We present a method for selective detection of size-dependent scattering characteristics of epithelial cells in vivo based on polarized illumination and polarization sensitive detection of scattered light. We illustrate the method using phantoms designed to simulate squamous epithelial tissue and progressing to epithelial tissue in vitro and in vivo. Elastic light scattering spectroscopy with polarized illumination/detection dramatically reduces background signals due to both diffuse stromal scattering and hemoglobin absorption. Resulting spectra can be described as a linear combination of forward and backscattering components determined from Mie theory. Nuclear sizes and refractive indices extracted by fitting experimental spectra to this model agree well with previous measurements. Reflectance spectroscopy with polarized light can provide quantitative morphological information which could potentially be used for non-invasive detection of neoplastic changes.

  7. Anthocyanidins modulate the activity of human DNA topoisomerases I and II and affect cellular DNA integrity.

    PubMed

    Habermeyer, Michael; Fritz, Jessica; Barthelmes, Hans U; Christensen, Morten O; Larsen, Morten K; Boege, Fritz; Marko, Doris

    2005-09-01

    In the present study, we investigated the effect of anthocyanidins on human topoisomerases I and II and its relevance for DNA integrity within human cells. Anthocyanidins bearing vicinal hydroxy groups at the B-ring (delphinidin, DEL; cyanidin, CY) were found to potently inhibit the catalytic activity of human topoisomerases I and II, without discriminating between the IIalpha and the IIbeta isoforms. However, in contrast to topoisomerase poisons, DEL and CY did not stabilize the covalent DNA-topoisomerase intermediates (cleavable complex) of topoisomerase I or II. Using recombinant topoisomerase I, the presence of CY or DEL (> or = 1 microM) effectively prohibited the stabilization of the cleavable complex by the topoisomerase I poison camptothecin. We furthermore investigated whether the potential protective effect vs topoisomerase I poisons is reflected also on the cellular level, affecting the DNA damaging properties of camptothecin. Indeed, in HT29 cells, low micromolar concentrations of DEL (1-10 microM) significantly diminished the DNA strand breaking effect of camptothecin (100 microM). However, at concentrations > or = 50 microM, all anthocyanidins tested (delphinidin, cyanidin, malvidin, pelargonidin, and paeonidin), including those not interfering with topoisomerases, were found to induce DNA strand breaks in the comet assay. All of these analogues were able to compete with ethidium bromide for the intercalation into calf thymus DNA and to replace the minor groove binder Hoechst 33258. These data indicate substantial affinity to double-stranded DNA, which might contribute at least to the DNA strand breaking effect of anthocyanidins at higher concentrations (> or = 50 microM). PMID:16167831

  8. Propranolol affects stress-induced leukocytosis and cellular adhesion molecule expression.

    PubMed

    Kühlwein, E C; Irwin, M R; Ziegler, M G; Woods, V L; Kennedy, B; Mills, P J

    2001-12-01

    In this study, the impact of the beta-adrenergic antagonist propranolol on resting and acute psychological- and physical-stress-induced circulating leukocyte numbers and the density of cellular adhesion molecules was investigated. In a randomized double-blind crossover design, 45 healthy volunteers performed a 15-min public speaking task and 21 subjects performed a 16-min bicycle exercise after 5 days of ingesting a placebo and after 5 days of ingesting 100 mg/day propranolol. One week of ingesting propranolol modestly elevated the numbers of CD62L+ (P<0.019) but not CD62L- T-lymphocytes. Moreover, propranolol preferentially blunted-psychological stress-induced increases in naïve T-helper (CD4+CD62L+; P<0.049) and naïve T-cytotoxic lymphocytes (CD8+CD62L+; P<0.003), as well as activated T-cytotoxic lymphocytes (CD8+CD29+; P<0.005). However, exercise-induced increases in leukocyte numbers were enhanced following propranolol treatment (P<0.04). In contrast to the effect on the numbers of adhesion-molecule-bearing cells, there was only a modest effect of propranolol on stress-induced alterations of the density of CD62L, CD54 and CD11a. In this study, propranolol treatment interfered with the adrenergic regulation of circulating leukocyte numbers by blunting psychological stress effects but enhancing exercise effects. Propranolol affected the cell activation status to a lesser extent, as reflected by the density of adhesion molecules. PMID:11822472

  9. Cellular morphology of organic-inorganic hybrid foams based on alkali alumino-silicate matrix

    SciTech Connect

    Verdolotti, Letizia; Capasso, Ilaria; Lavorgna, Marino; Liguori, Barbara; Caputo, Domenico; Iannace, Salvatore

    2014-05-15

    Organic-inorganic hybrid foams based on an alkali alumino-silicate matrix were prepared by using different foaming methods. Initially, the synthesis of an inorganic matrix by using aluminosilicate particles, activated through a sodium silicate solution, was performed at room temperature. Subsequently the viscous paste was foamed by using three different methods. In the first method, gaseous hydrogen produced by the oxidization of Si powder in an alkaline media, was used as blowing agent to generate gas bubbles in the paste. In the second method, the porous structure was generated by mixing the paste with a “meringue” type of foam previously prepared by whipping, under vigorous stirring, a water solution containing vegetal proteins as surfactants. In the third method, a combination of these two methods was employed. The foamed systems were consolidated for 24 hours at 40°C and then characterized by FTIR, X-Ray diffraction, scanning electron microscopy (SEM) and compression tests. Low density foams (∼500 Kg/m{sup 3}) with good cellular structure and mechanical properties were obtained by combining the “meringue” approach with the use of the chemical blowing agent based on Si.

  10. Validation of vacuum-based refrigerated system for biobanking tissue preservation: analysis of cellular morphology, protein stability, and RNA quality.

    PubMed

    Condelli, Valentina; Lettini, Giacomo; Patitucci, Giuseppe; D'Auria, Fiorella; D'Amico, Michele; Vita, Giulia; Musto, Pellegrino; Cuomo, Carmela; Landriscina, Matteo

    2014-02-01

    Biobanks of fresh, unfixed human normal and malignant tissues represent a valuable source for gene expression analysis in translational cancer research and molecular pathology. However, the success of molecular and cellular analysis in both clinical and translational research is strongly dependent on the collection, handling, storage, and quality control of fresh human tissue samples. The aim of this study was to evaluate an innovative vacuum-based refrigerated system, as a logistically feasible technology to increase the collection of tissue specimens, preserving the integrity of cellular and molecular components. We tested randomly-selected tissues stored under vacuum at 4°C by using endpoints important for research and diagnosis, including tissue morphology, epitope stability, and RNA integrity. Gene expression was evaluated by qualitative and quantitative RT analysis of selected housekeeping and tissue-specific genes. Tissue morphology and overall protein stability were generally well preserved, being compromised only in gallbladder tissue. By contrast, phosphoprotein and RNA analysis demonstrated a time-dependent degree of degradation, with progressive loss of stability from 24 to 72 hours. However, this reduction in RNA quality did not represent a limitation for successful expression analysis of selected genes. Indeed, a comparative qualitative and quantitative RT-PCR analysis showed that RNA extracted from tissues stored under vacuum is suitable for gene expression profiling, but requires highly sensitive technologies, such as quantitative RT-PCR. These data suggest that the refrigerated vacuum-based system represents a suitable and feasible technology for routine transport of fresh specimens from surgery to biobanks, thus increasing the opportunity to collect biospecimens. PMID:24620768

  11. In-vivo imaging of inner retinal cellular morphology with adaptive optics - optical coherence tomography: challenges and possible solutions

    NASA Astrophysics Data System (ADS)

    Zawadzki, Robert J.; Jones, Steven M.; Kim, Dae Yu; Poyneer, Lisa; Capps, Arlie G.; Hamann, Bernd; Olivier, Scot S.; Werner, John S.

    2012-03-01

    Recent progress in retinal image acquisition techniques, including optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO), combined with improved performance of adaptive optics (AO) instrumentation, has resulted in improvement in the quality of in vivo images of cellular structures in the outer layers of the human retina. Despite the significant progress in imaging cone and rod photoreceptor mosaics, visualization of cellular structures in the inner retina has been achieved only with extrinsic contrast agents that have not been approved for use with humans. In this paper we describe the main limiting factors in visualizing inner retinal cells and the methods we implemented to reduce their effects on images acquired with AO-OCT. These include improving the system point spread function (AO performance), monitoring of motion artifacts (retinal motion tracking), and speckle pattern reduction (temporal and spatial averaging). Results of imaging inner retinal morphology and the improvement offered by the new UC Davis AOOCT system with spatio-temporal image averaging are presented.

  12. Cross-talk between Rho and Rac GTPases drives deterministic exploration of cellular shape space and morphological heterogeneity.

    PubMed

    Sailem, Heba; Bousgouni, Vicky; Cooper, Sam; Bakal, Chris

    2014-01-01

    One goal of cell biology is to understand how cells adopt different shapes in response to varying environmental and cellular conditions. Achieving a comprehensive understanding of the relationship between cell shape and environment requires a systems-level understanding of the signalling networks that respond to external cues and regulate the cytoskeleton. Classical biochemical and genetic approaches have identified thousands of individual components that contribute to cell shape, but it remains difficult to predict how cell shape is generated by the activity of these components using bottom-up approaches because of the complex nature of their interactions in space and time. Here, we describe the regulation of cellular shape by signalling systems using a top-down approach. We first exploit the shape diversity generated by systematic RNAi screening and comprehensively define the shape space a migratory cell explores. We suggest a simple Boolean model involving the activation of Rac and Rho GTPases in two compartments to explain the basis for all cell shapes in the dataset. Critically, we also generate a probabilistic graphical model to show how cells explore this space in a deterministic, rather than a stochastic, fashion. We validate the predictions made by our model using live-cell imaging. Our work explains how cross-talk between Rho and Rac can generate different cell shapes, and thus morphological heterogeneity, in genetically identical populations. PMID:24451547

  13. 1. Morphological Implication on Cellular Response to Mechanical Stress in Bone.

    PubMed

    Amizuka, Norio

    2016-08-01

    In bone, there are 3 distinct cell types: an osteoblast, a bone forming cell; an osteocyte embedded in bone matrix as a consequence of being differentiated from an osteoblast; and an osteoclast, a multinucleated giant cell responsible for bone resorption. Bone is always remodeled by replacing old bone with new bone (bone remodeling), by which bone can maintain its stiffness and flexibility. However, in an osteoporotic state, the disrupted balance between bone resorption and formation results in not only markedly reduced bone mass, but also in disorganized geometry of trabecules, which can often give rise to a bone fracture. Osteocytes located in their lacunae insert their fine cytoplasmic processes into narrow passageways referred to as osteocytic canaliculi. Neighboring osteocytes connect to each other by means of a gap junction in their cytoplasmic processes. Therefore, osteocytes and their lacunae/canaliculi appear to form functional syncytium called osteocytic lacunar canalicular system (OLCS). The geometrical distribution of OLCS is poorly arranged in immature bone, while it appears well-arranged distribution in mature bone (cortical bone), in which molecular transports and sensing mechanical stress seems to be efficient, and therefore, may be able to respond to mechanical stress. In this seminar, I will introduce our recent findings on the morphology and function of OLCS which may respond to mechanical stress. PMID:27441762

  14. Evaluating Cytotoxicity and Cellular Uptake from the Presence of Variously Processed Ti02 Nanostructured Morphologies

    SciTech Connect

    Chen, J.; Wong, S.; Zhou, H.; Santull, A.C.

    2010-05-01

    We evaluated the cytotoxicity of various morphological classes of TiO{sub 2} nanostructures (including 0-D nanoparticles, 1-D nanorods, and 3-D assemblies) toward living cells. These TiO{sub 2} nanostructures were modified with fluorescent dye molecules, mediated via a dopamine linkage, in order to facilitate a confocal study of their internalization. Specifically, we noted that both TiO{sub 2} 1-D nanorods and 0-D nanoparticles could internalize into cells after 24 h of incubation time. However, only incubation with TiO{sub 2} 1-D nanorods and 3-D micrometer-scale sea urchin-like assemblies at concentrations of up to 125 {mu}g/mL yielded data suggestive of cell viabilities of close to 100%. Moreover, upon irradiation with UV light for periods of a few minutes at energy densities of up to 1 J/cm{sub 2}, we observed up to 60% mortality rates, indicative of the cytotoxic potential of photoirradiated TiO{sub 2} nanostructures due to the generation of reactive oxygen species.

  15. Protein coronas on gold nanorods passivated with amphiphilic ligands affect cytotoxicity and cellular response to penicillin/streptomycin.

    PubMed

    Kah, James Chen Yong; Grabinski, Christin; Untener, Emily; Garrett, Carol; Chen, John; Zhu, David; Hussain, Saber M; Hamad-Schifferli, Kimberly

    2014-05-27

    We probe how amphiphilic ligands (ALs) of four different types affect the formation of protein coronas on gold nanorods (NRs) and their impact on cellular response. NRs coated with cetyltrimethylammonium bromide were ligand exchanged with polyoxyethylene[10]cetyl ether, oligofectamine, and phosphatidylserine (PS). Protein coronas from equine serum (ES) were formed on these NR-ALs, and their colloidal stability, as well as cell uptake, proliferation, oxidative stress, and gene expression, were examined. We find that the protein corona that forms and its colloidal stability are affected by AL type and that the cellular response to these NR-AL-coronas (NR-AL-ES) is both ligand and corona dependent. We also find that the presence of common cell culture supplement penicillin/streptomycin can impact the colloidal stability and cellular response of NR-AL and NR-AL-ES, showing that the cell response is not necessarily inert to pen/strep when in the presence of nanoparticles. Although the protein corona is what the cells see, the underlying surface ligands evidently play an important role in shaping and defining the physical characteristics of the corona, which ultimately impacts the cellular response. Further, the results of this study suggest that the cellular behavior toward NR-AL is mediated by not only the type of AL and the protein corona it forms but also its resulting colloidal stability and interaction with cell culture supplements. PMID:24758495

  16. Revealing the sequence and resulting cellular morphology of receptor-ligand interactions during Plasmodium falciparum invasion of erythrocytes.

    PubMed

    Weiss, Greta E; Gilson, Paul R; Taechalertpaisarn, Tana; Tham, Wai-Hong; de Jong, Nienke W M; Harvey, Katherine L; Fowkes, Freya J I; Barlow, Paul N; Rayner, Julian C; Wright, Gavin J; Cowman, Alan F; Crabb, Brendan S

    2015-02-01

    During blood stage Plasmodium falciparum infection, merozoites invade uninfected erythrocytes via a complex, multistep process involving a series of distinct receptor-ligand binding events. Understanding each element in this process increases the potential to block the parasite's life cycle via drugs or vaccines. To investigate specific receptor-ligand interactions, they were systematically blocked using a combination of genetic deletion, enzymatic receptor cleavage and inhibition of binding via antibodies, peptides and small molecules, and the resulting temporal changes in invasion and morphological effects on erythrocytes were filmed using live cell imaging. Analysis of the videos have shown receptor-ligand interactions occur in the following sequence with the following cellular morphologies; 1) an early heparin-blockable interaction which weakly deforms the erythrocyte, 2) EBA and PfRh ligands which strongly deform the erythrocyte, a process dependant on the merozoite's actin-myosin motor, 3) a PfRh5-basigin binding step which results in a pore or opening between parasite and host through which it appears small molecules and possibly invasion components can flow and 4) an AMA1-RON2 interaction that mediates tight junction formation, which acts as an anchor point for internalization. In addition to enhancing general knowledge of apicomplexan biology, this work provides a rational basis to combine sequentially acting merozoite vaccine candidates in a single multi-receptor-blocking vaccine. PMID:25723550

  17. Revealing the Sequence and Resulting Cellular Morphology of Receptor-Ligand Interactions during Plasmodium falciparum Invasion of Erythrocytes

    PubMed Central

    Weiss, Greta E.; Gilson, Paul R.; Taechalertpaisarn, Tana; Tham, Wai-Hong; de Jong, Nienke W. M.; Harvey, Katherine L.; Fowkes, Freya J. I.; Barlow, Paul N.; Rayner, Julian C.; Wright, Gavin J.; Cowman, Alan F.; Crabb, Brendan S.

    2015-01-01

    During blood stage Plasmodium falciparum infection, merozoites invade uninfected erythrocytes via a complex, multistep process involving a series of distinct receptor-ligand binding events. Understanding each element in this process increases the potential to block the parasite’s life cycle via drugs or vaccines. To investigate specific receptor-ligand interactions, they were systematically blocked using a combination of genetic deletion, enzymatic receptor cleavage and inhibition of binding via antibodies, peptides and small molecules, and the resulting temporal changes in invasion and morphological effects on erythrocytes were filmed using live cell imaging. Analysis of the videos have shown receptor-ligand interactions occur in the following sequence with the following cellular morphologies; 1) an early heparin-blockable interaction which weakly deforms the erythrocyte, 2) EBA and PfRh ligands which strongly deform the erythrocyte, a process dependant on the merozoite’s actin-myosin motor, 3) a PfRh5-basigin binding step which results in a pore or opening between parasite and host through which it appears small molecules and possibly invasion components can flow and 4) an AMA1–RON2 interaction that mediates tight junction formation, which acts as an anchor point for internalization. In addition to enhancing general knowledge of apicomplexan biology, this work provides a rational basis to combine sequentially acting merozoite vaccine candidates in a single multi-receptor-blocking vaccine. PMID:25723550

  18. Temporal dynamics of changes in reactive oxygen species (ROS) levels and cellular morphology are coordinated during complementary chromatic acclimation in Fremyella diplosiphon.

    PubMed

    Singh, Shailendra P; Miller, Haley L; Montgomery, Beronda L

    2013-10-14

    Fremyella diplosiphon alters the phycobiliprotein composition of its light-harvesting complexes, i.e., phycobilisomes, and its cellular morphology in response to changes in the prevalent wavelengths of light in the external environment in a phenomenon known as complementary chromatic acclimation (CCA). The organism primarily responds to red light (RL) and green light (GL) during CCA to maximize light absorption for supporting optimal photosynthetic efficiency. Recently, we found that RL-characteristic spherical cell morphology is associated with higher levels of reactive oxygen species (ROS) compared to growth under GL where lower ROS levels and rectangular cell shape are observed. The RL-dependent association of increased ROS levels with cellular morphology was demonstrated by treating cells with a ROS-scavenging antioxidant which resulted in the observation of GL-characteristic rectangular morphology under RL. To gain additional insights into the involvement of ROS in impacting cellular morphology changes during CCA, we conducted experiments to study the temporal dynamics of changes in ROS levels and cellular morphology during transition to growth under RL or GL. Alterations in ROS levels and cell morphology were found to be correlated with each other at early stages of acclimation of low white light-grown cells to growth under high RL or cells transitioned between growth in RL and GL. These results provide further general evidence that significant RL-dependent increases in ROS levels are temporally correlated with changes in morphology toward spherical. Future studies will explore the light-dependent mechanisms by which ROS levels may be regulated and the direct impacts of ROS on the observed morphology changes. PMID:24122367

  19. MOBP levels are regulated by Fyn kinase and affect the morphological differentiation of oligodendrocytes.

    PubMed

    Schäfer, Isabelle; Müller, Christina; Luhmann, Heiko J; White, Robin

    2016-03-01

    Oligodendrocytes are the myelinating glial cells of the central nervous system (CNS). Myelin is formed by extensive wrapping of oligodendroglial processes around axonal segments, which ultimately allows a rapid saltatory conduction of action potentials within the CNS and sustains neuronal health. The non-receptor tyrosine kinase Fyn is an important signaling molecule in oligodendrocytes. It controls the morphological differentiation of oligodendrocytes and is an integrator of axon-glial signaling cascades leading to localized synthesis of myelin basic protein (MBP), which is essential for myelin formation. The abundant myelin-associated oligodendrocytic basic protein (MOBP) resembles MBP in several aspects and has also been reported to be localized as mRNA and translated in the peripheral myelin compartment. The signals initiating local MOBP synthesis are so far unknown and the cellular function of MOBP remains elusive. Here, we show, by several approaches in cultured primary oligodendrocytes, that MOBP synthesis is stimulated by Fyn activity. Moreover, we reveal a new function for MOBP in oligodendroglial morphological differentiation. PMID:26801084

  20. Molecular and cellular targets affected by green tea extracts in vascular cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumption of green or black tea has been associated with a lower risk for the development of cardiovascular diseases, but despite many studies, a firm connection has not been delineated. Several molecular and cellular mechanisms may play a role in the preventive activity of tea. As reviewed here, ...

  1. Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants

    PubMed Central

    Nash, Michael A.; Christie, Fiona J.; Hahs, Amy K.; Livesley, Stephen J.

    2015-01-01

    Habitat complexity is a major determinant of structure and diversity of ant assemblages. Following the size-grain hypothesis, smaller ant species are likely to be advantaged in more complex habitats compared to larger species. Habitat complexity can act as an environmental filter based on species size and morphological traits, therefore affecting the overall structure and diversity of ant assemblages. In natural and semi-natural ecosystems, habitat complexity is principally regulated by ecological successions or disturbance such as fire and grazing. Urban ecosystems provide an opportunity to test relationships between habitat, ant assemblage structure and ant traits using novel combinations of habitat complexity generated and sustained by human management. We sampled ant assemblages in low-complexity and high-complexity parks, and high-complexity woodland remnants, hypothesizing that (i) ant abundance and species richness would be higher in high-complexity urban habitats, (ii) ant assemblages would differ between low- and high-complexity habitats and (iii) ants living in high-complexity habitats would be smaller than those living in low-complexity habitats. Contrary to our hypothesis, ant species richness was higher in low-complexity habitats compared to high-complexity habitats. Overall, ant assemblages were significantly different among the habitat complexity types investigated, although ant size and morphology remained the same. Habitat complexity appears to affect the structure of ant assemblages in urban ecosystems as previously observed in natural and semi-natural ecosystems. However, the habitat complexity filter does not seem to be linked to ant morphological traits related to body size. PMID:26528416

  2. Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants.

    PubMed

    Ossola, Alessandro; Nash, Michael A; Christie, Fiona J; Hahs, Amy K; Livesley, Stephen J

    2015-01-01

    Habitat complexity is a major determinant of structure and diversity of ant assemblages. Following the size-grain hypothesis, smaller ant species are likely to be advantaged in more complex habitats compared to larger species. Habitat complexity can act as an environmental filter based on species size and morphological traits, therefore affecting the overall structure and diversity of ant assemblages. In natural and semi-natural ecosystems, habitat complexity is principally regulated by ecological successions or disturbance such as fire and grazing. Urban ecosystems provide an opportunity to test relationships between habitat, ant assemblage structure and ant traits using novel combinations of habitat complexity generated and sustained by human management. We sampled ant assemblages in low-complexity and high-complexity parks, and high-complexity woodland remnants, hypothesizing that (i) ant abundance and species richness would be higher in high-complexity urban habitats, (ii) ant assemblages would differ between low- and high-complexity habitats and (iii) ants living in high-complexity habitats would be smaller than those living in low-complexity habitats. Contrary to our hypothesis, ant species richness was higher in low-complexity habitats compared to high-complexity habitats. Overall, ant assemblages were significantly different among the habitat complexity types investigated, although ant size and morphology remained the same. Habitat complexity appears to affect the structure of ant assemblages in urban ecosystems as previously observed in natural and semi-natural ecosystems. However, the habitat complexity filter does not seem to be linked to ant morphological traits related to body size. PMID:26528416

  3. LRRK2 and RAB7L1 coordinately regulate axonal morphology and lysosome integrity in diverse cellular contexts

    PubMed Central

    Kuwahara, Tomoki; Inoue, Keiichi; D’Agati, Vivette D.; Fujimoto, Tetta; Eguchi, Tomoya; Saha, Shamol; Wolozin, Benjamin; Iwatsubo, Takeshi; Abeliovich, Asa

    2016-01-01

    Leucine-rich repeat kinase 2 (LRRK2) has been linked to several clinical disorders including Parkinson’s disease (PD), Crohn’s disease, and leprosy. Furthermore in rodents, LRRK2 deficiency or inhibition leads to lysosomal pathology in kidney and lung. Here we provide evidence that LRRK2 functions together with a second PD-associated gene, RAB7L1, within an evolutionarily conserved genetic module in diverse cellular contexts. In C. elegans neurons, orthologues of LRRK2 and RAB7L1 act coordinately in an ordered genetic pathway to regulate axonal elongation. Further genetic studies implicated the AP-3 complex, which is a known regulator of axonal morphology as well as of intracellular protein trafficking to the lysosome compartment, as a physiological downstream effector of LRRK2 and RAB7L1. Additional cell-based studies implicated LRRK2 in the AP-3 complex-related intracellular trafficking of lysosomal membrane proteins. In mice, deficiency of either RAB7L1 or LRRK2 leads to prominent age-associated lysosomal defects in kidney proximal tubule cells, in the absence of frank CNS pathology. We hypothesize that defects in this evolutionarily conserved genetic pathway underlie the diverse pathologies associated with LRRK2 in humans and in animal models. PMID:27424887

  4. LRRK2 and RAB7L1 coordinately regulate axonal morphology and lysosome integrity in diverse cellular contexts.

    PubMed

    Kuwahara, Tomoki; Inoue, Keiichi; D'Agati, Vivette D; Fujimoto, Tetta; Eguchi, Tomoya; Saha, Shamol; Wolozin, Benjamin; Iwatsubo, Takeshi; Abeliovich, Asa

    2016-01-01

    Leucine-rich repeat kinase 2 (LRRK2) has been linked to several clinical disorders including Parkinson's disease (PD), Crohn's disease, and leprosy. Furthermore in rodents, LRRK2 deficiency or inhibition leads to lysosomal pathology in kidney and lung. Here we provide evidence that LRRK2 functions together with a second PD-associated gene, RAB7L1, within an evolutionarily conserved genetic module in diverse cellular contexts. In C. elegans neurons, orthologues of LRRK2 and RAB7L1 act coordinately in an ordered genetic pathway to regulate axonal elongation. Further genetic studies implicated the AP-3 complex, which is a known regulator of axonal morphology as well as of intracellular protein trafficking to the lysosome compartment, as a physiological downstream effector of LRRK2 and RAB7L1. Additional cell-based studies implicated LRRK2 in the AP-3 complex-related intracellular trafficking of lysosomal membrane proteins. In mice, deficiency of either RAB7L1 or LRRK2 leads to prominent age-associated lysosomal defects in kidney proximal tubule cells, in the absence of frank CNS pathology. We hypothesize that defects in this evolutionarily conserved genetic pathway underlie the diverse pathologies associated with LRRK2 in humans and in animal models. PMID:27424887

  5. Irradiation affects cellular properties and Eph receptor expression in human melanoma cells

    PubMed Central

    Mosch, Birgit; Pietzsch, Doreen; Pietzsch, Jens

    2012-01-01

    X-ray irradiation influences metastatic properties of tumor cells and, moreover, metastasis and cellular motility can be modified by members of the Eph receptor/ephrin family of receptor tyrosine kinases. We hypothesized that irradiation-induced changes in cellular properties relevant for metastasis in melanoma cells could be mediated by Eph receptor/ephrin signaling. In this pilot study, we analyzed one pre-metastatic (Mel-Juso) and three metastatic human melanoma (Mel-Juso-L3, A375, and A2058) cells lines and predominantly found anti-metastatic effects of X-ray irradiation with impaired cell growth, clonal growth and motility. Additionally, we observed an irradiation-induced increase in adhesion paralleled by a decrease in migration in Mel-Juso and Mel-Juso-L3 cells and, in part, also in A375 cells. We further demonstrate a decrease of EphA2 both in expression and activity at 7 d after irradiation paralleled by an upregulation of EphA3. Analyzing downstream signaling after irradiation, we detected decreased Src kinase phosphorylation, but unchanged focal adhesion kinase (FAK) phosphorylation, indicating, in part, irradiation-induced downregulation of signaling via the EphA2-Src-FAK axis in melanoma cells. However, to which extent this finding contributes to the modification of metastasis-relevant cellular properties remains to be elucidated. PMID:22568947

  6. Hydrogeologic factors affecting cavern morphology within rocks of Mississippian age in northwestern Arkansas

    SciTech Connect

    Fanning, B.J. . Dept. of Geology); Brahana, J.V. . Geological Survey)

    1993-02-01

    Cavern development within rocks of Mississippian age in northwestern Arkansas is associated with two Pleistocene erosional features, the Boston Mountains Plateau and the Springfield Plateau. Each plateau is characterized by a distinct stratigraphic sequence with unique lithologies. Cavern morphology (both cross-sectional and planimetric) in each plateau is the result of the complex interaction of numerous hydrogeologic factors. Four of the most dominant factors which affect cavern morphology appear to be: (1) composition and continuity of the confining units; (2) percentage of noncarbonate components in rocks of the cavern-forming interval; (3) nature and distribution of ground-water recharge to the cavern-forming interval; and (4) nature and distribution of fractures within the cavern-forming interval. Network maze patterns typically develop in the Pitkin Limestone, the formation in which most caverns form beneath the Boston Mountains Plateau. The Pitkin, a bioclastic limestone, is confined above by siltstones of the Cane Hill member of the Hale Formation and below by shales of the Fayetteville Formation. The maze pattern indicates that these caverns probably were formed by dissolution of the rock matrix by diffuse recharge moving vertically through leaky confining units. Single rooms are the dominant cavern morphology in the chert-dominated Boone Formation of the Springfield Plateau. Where the concentration of chert is greater than 50 percent, the Boone lacks structural integrity and fails to develop well-integrated conduit networks. Point recharge features in outcrop areas of the Boone Formation are not visible in most of the Springfield Plateau because the insoluble residuum masks the upper bedrock surface. Where the Boone Formation is less than 7 meters thick, surface karst features are more prevalent.

  7. Slight temperature changes affect protein affinity and cellular uptake/toxicity of nanoparticles

    NASA Astrophysics Data System (ADS)

    Mahmoudi, Morteza; Shokrgozar, Mohammad A.; Behzadi, Shahed

    2013-03-01

    It is known that what the cell actually ``sees'' at the nanoscale is an outer shell formed of `protein corona' on the surface of nanoparticles (NPs). The amount and composition of various proteins on the corona are strongly dependent on the biophysicochemical properties of NPs, which have been extensively studied. However, the effect of a small variation in temperature, due to the human circadian rhythm, on the composition of the protein corona and the affinity of various proteins to the surface of NPs, was ignored. Here, the effect of temperature on the composition of protein corona and the affinity of various proteins to the surface of NPs and, subsequently, cell responses to the protein coated NPs are probed. The results confirmed that cellular entrance, dispersion, and toxicity of NPs are strongly diverse with slight body temperature changes. This new finding can help scientists to maximise NP entrance to specific cells/organs with lower toxicity by adjusting the cellular/organ temperature.It is known that what the cell actually ``sees'' at the nanoscale is an outer shell formed of `protein corona' on the surface of nanoparticles (NPs). The amount and composition of various proteins on the corona are strongly dependent on the biophysicochemical properties of NPs, which have been extensively studied. However, the effect of a small variation in temperature, due to the human circadian rhythm, on the composition of the protein corona and the affinity of various proteins to the surface of NPs, was ignored. Here, the effect of temperature on the composition of protein corona and the affinity of various proteins to the surface of NPs and, subsequently, cell responses to the protein coated NPs are probed. The results confirmed that cellular entrance, dispersion, and toxicity of NPs are strongly diverse with slight body temperature changes. This new finding can help scientists to maximise NP entrance to specific cells/organs with lower toxicity by adjusting the cellular

  8. Intermittent hypoxia leads to functional reorganization of mitochondria and affects cellular bioenergetics in marine molluscs.

    PubMed

    Ivanina, Anna V; Nesmelova, Irina; Leamy, Larry; Sokolov, Eugene P; Sokolova, Inna M

    2016-06-01

    Fluctuations in oxygen (O2) concentrations represent a major challenge to aerobic organisms and can be extremely damaging to their mitochondria. Marine intertidal molluscs are well-adapted to frequent O2 fluctuations, yet it remains unknown how their mitochondrial functions are regulated to sustain energy metabolism and prevent cellular damage during hypoxia and reoxygenation (H/R). We used metabolic control analysis to investigate the mechanisms of mitochondrial responses to H/R stress (18 h at <0.1% O2 followed by 1 h of reoxygenation) using hypoxia-tolerant intertidal clams Mercenaria mercenaria and hypoxia-sensitive subtidal scallops Argopecten irradians as models. We also assessed H/R-induced changes in cellular energy balance, oxidative damage and unfolded protein response to determine the potential links between mitochondrial dysfunction and cellular injury. Mitochondrial responses to H/R in scallops strongly resembled those in other hypoxia-sensitive organisms. Exposure to hypoxia followed by reoxygenation led to a strong decrease in the substrate oxidation (SOX) and phosphorylation (PHOS) capacities as well as partial depolarization of mitochondria of scallops. Elevated mRNA expression of a reactive oxygen species-sensitive enzyme aconitase and Lon protease (responsible for degradation of oxidized mitochondrial proteins) during H/R stress was consistent with elevated levels of oxidative stress in mitochondria of scallops. In hypoxia-tolerant clams, mitochondrial SOX capacity was enhanced during hypoxia and continued rising during the first hour of reoxygenation. In both species, the mitochondrial PHOS capacity was suppressed during hypoxia, likely to prevent ATP wastage by the reverse action of FO,F1-ATPase. The PHOS capacity recovered after 1 h of reoxygenation in clams but not in scallops. Compared with scallops, clams showed a greater suppression of energy-consuming processes (such as protein turnover and ion transport) during hypoxia, indicated

  9. Effective Cellular Morphology Analysis for Differentiation Processes by a Fluorescent 1,3a,6a-Triazapentalene Derivative Probe in Live Cells

    PubMed Central

    Kamada, Rui; Tano, Fumi; Kudoh, Fuki; Kimura, Nozomi; Chuman, Yoshiro; Osawa, Ayumi; Namba, Kosuke; Tanino, Keiji; Sakaguchi, Kazuyasu

    2016-01-01

    Nuclear and cytoplasmic morphological changes provide important information about cell differentiation processes, cell functions, and signal responses. There is a strong desire to develop a rapid and simple method for visualizing cytoplasmic and nuclear morphology. Here, we developed a novel and rapid method for probing cellular morphological changes of live cell differentiation process by a fluorescent probe, TAP-4PH, a 1,3a,6a-triazapentalene derivative. TAP-4PH showed high fluorescence in cytoplasmic area, and visualized cytoplasmic and nuclear morphological changes of live cells during differentiation. We demonstrated that TAP-4PH visualized dendritic axon and spine formation in neuronal differentiation, and nuclear structural changes during neutrophilic differentiation. We also showed that the utility of TAP-4PH for visualization of cytoplasmic and nuclear morphologies of various type of live cells. Our visualizing method has no toxicity and no influence on the cellular differentiation and function. The cell morphology can be rapidly observed after addition of TAP-4PH and can continue to be observed in the presence of TAP-4PH in cell culture medium. Moreover, TAP-4PH can be easily removed after observation by washing for subsequent biological assay. Taken together, these results demonstrate that our visualization method is a powerful tool to probe differentiation processes before subsequent biological assay in live cells. PMID:27490470

  10. Aircraft noise exposure affects rat behavior, plasma norepinephrine levels, and cell morphology of the temporal lobe*

    PubMed Central

    Di, Guo-qing; Zhou, Bing; Li, Zheng-guang; Lin, Qi-li

    2011-01-01

    In order to investigate the physiological effects of airport noise exposure on organisms, in this study, we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d. For comparison, we also used unexposed control rats. Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels (L WECPN) of 75 and 80 dB for the two experimental groups. We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine (NE) by high performance liquid chromatography-fluorimetric detection (HPLC-FLD). We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy (TEM). Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number (P<0.05) and significantly longer center area duration (P<0.05) than control animals. After 29 d of airport noise exposure, the concentration of plasma NE of exposed rats was significantly higher than that of the control group (P<0.05). We also determined that the neuron and synapsis of the temporal lobe of rats showed signs of damage after aircraft noise of 80 dB exposure for 65 d. In conclusion, exposing rats to long-term aircraft noise affects their behaviors, plasma NE levels, and cell morphology of the temporal lobe. PMID:22135145

  11. Aircraft noise exposure affects rat behavior, plasma norepinephrine levels, and cell morphology of the temporal lobe.

    PubMed

    Di, Guo-Qing; Zhou, Bing; Li, Zheng-Guang; Lin, Qi-Li

    2011-12-01

    In order to investigate the physiological effects of airport noise exposure on organisms, in this study, we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d. For comparison, we also used unexposed control rats. Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels (L(WECPN)) of 75 and 80 dB for the two experimental groups. We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine (NE) by high performance liquid chromatography-fluorimetric detection (HPLC-FLD). We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy (TEM). Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number (P<0.05) and significantly longer center area duration (P<0.05) than control animals. After 29 d of airport noise exposure, the concentration of plasma NE of exposed rats was significantly higher than that of the control group (P<0.05). We also determined that the neuron and synapsis of the temporal lobe of rats showed signs of damage after aircraft noise of 80 dB exposure for 65 d. In conclusion, exposing rats to long-term aircraft noise affects their behaviors, plasma NE levels, and cell morphology of the temporal lobe. PMID:22135145

  12. SAMM50 Affects Mitochondrial Morphology through the Association of Drp1 in Mammalian Cells.

    PubMed

    Liu, Shuo; Gao, Yali; Zhang, Cheng; Li, Han; Pan, Shiyi; Wang, Xiaoli; Du, Shiming; Deng, Zixin; Wang, Lianrong; Song, Zhiyin; Chen, Shi

    2016-05-01

    Mitochondrial fission and fusion activities are important for cell survival and function. Drp1 is a GTPase protein responsible for mitochondrial division, and SAMM50 is responsible for protein sorting and assembly. We demonstrated that SAMM50 overexpression results in Drp1-dependent mitochondrial fragmentation in HeLa cells. However, the mitochondrial fragmentation induced by SAMM50 overexpression could be reversed through co-expression with MFN2. Furthermore, SAMM50 interacts with Drp1 both in vivo and in vitro. The mitochondria in SAMM50 knockdown HeLa cells displayed a swollen phenotype, and the levels of the SAM complex and OPA1, along with the mitochondrial Drp1 levels, significantly decreased. In addition, mitochondrial inheritance was impaired in SAMM50 silenced cells. These results suggest that SAMM50 affects the Drp1-dependent mitochondrial morphology. PMID:27059175

  13. Oxidized (non)-regenerated cellulose affects fundamental cellular processes of wound healing

    PubMed Central

    Wagenhäuser, M. U.; Mulorz, J.; Ibing, W.; Simon, F.; Spin, J. M.; Schelzig, H.; Oberhuber, A.

    2016-01-01

    In this study we investigated how hemostats such as oxidized regenerated cellulose (ORC, TABOTAMP) and oxidized non-regenerated cellulose (ONRC, RESORBA CELL) influence local cellular behavior and contraction of the extracellular matrix (ECM). Human stromal fibroblasts were inoculated in vitro with ORC and ONRC. Cell proliferation was assayed over time, and migration was evaluated by Live Cell imaging microscopy. Fibroblasts grown in collagen-gels were treated with ORC or ONRC, and ECM contraction was measured utilizing a contraction assay. An absolute pH decline was observed with both ORC and ONRC after 1 hour. Mean daily cell proliferation, migration and matrix contraction were more strongly inhibited by ONRC when compared with ORC (p < 0.05). When control media was pH-lowered to match the lower pH values typically seen with ORC and ONRC, significant differences in cell proliferation and migration were still observed between ONRC and ORC (p < 0.05). However, in these pH conditions, inhibition of matrix contraction was only significant for ONRC (p < 0.05). We find that ORC and ONRC inhibit fibroblast proliferation, migration and matrix contraction, and stronger inhibition of these essential cellular processes of wound healing were observed for ONRC when compared with ORC. These results will require further validation in future in vivo experiments to clarify the clinical implications for hemostat use in post-surgical wound healing. PMID:27557881

  14. Oxidized (non)-regenerated cellulose affects fundamental cellular processes of wound healing.

    PubMed

    Wagenhäuser, M U; Mulorz, J; Ibing, W; Simon, F; Spin, J M; Schelzig, H; Oberhuber, A

    2016-01-01

    In this study we investigated how hemostats such as oxidized regenerated cellulose (ORC, TABOTAMP) and oxidized non-regenerated cellulose (ONRC, RESORBA CELL) influence local cellular behavior and contraction of the extracellular matrix (ECM). Human stromal fibroblasts were inoculated in vitro with ORC and ONRC. Cell proliferation was assayed over time, and migration was evaluated by Live Cell imaging microscopy. Fibroblasts grown in collagen-gels were treated with ORC or ONRC, and ECM contraction was measured utilizing a contraction assay. An absolute pH decline was observed with both ORC and ONRC after 1 hour. Mean daily cell proliferation, migration and matrix contraction were more strongly inhibited by ONRC when compared with ORC (p < 0.05). When control media was pH-lowered to match the lower pH values typically seen with ORC and ONRC, significant differences in cell proliferation and migration were still observed between ONRC and ORC (p < 0.05). However, in these pH conditions, inhibition of matrix contraction was only significant for ONRC (p < 0.05). We find that ORC and ONRC inhibit fibroblast proliferation, migration and matrix contraction, and stronger inhibition of these essential cellular processes of wound healing were observed for ONRC when compared with ORC. These results will require further validation in future in vivo experiments to clarify the clinical implications for hemostat use in post-surgical wound healing. PMID:27557881

  15. Altered Competitive Fitness, Antimicrobial Susceptibility, and Cellular Morphology in a Triclosan-Induced Small-Colony Variant of Staphylococcus aureus

    PubMed Central

    Forbes, Sarah; Latimer, Joe; Bazaid, Abdulrahman

    2015-01-01

    Staphylococcus aureus can produce small-colony variants (SCVs) that express various phenotypes. While their significance is unclear, SCV propagation may be influenced by relative fitness, antimicrobial susceptibility, and the underlying mechanism. We have investigated triclosan-induced generation of SCVs in six S. aureus strains, including methicillin-resistant S. aureus (MRSA). Parent strains (P0) were repeatedly passaged on concentration gradients of triclosan using a solid-state exposure system to generate P10. P10 was subsequently passaged without triclosan to generate X10. Susceptibility to triclosan and 7 antibiotics was assessed at all stages. For S. aureus ATCC 6538, SCVs were further characterized by determining microbicide susceptibility and competitive fitness. Cellular morphology was examined using electron microscopy, and protein expression was evaluated through proteomics. Triclosan susceptibility in all SCVs (which could be generated from 4/6 strains) was markedly decreased, while antibiotic susceptibility was significantly increased in the majority of cases. An SCV of S. aureus ATCC 6538 exhibited significantly increased susceptibility to all tested microbicides. Cross-wall formation was impaired in this bacterium, while expression of FabI, a target of triclosan, and IsaA, a lytic transglycosylase involved in cell division, was increased. The P10 SCV was 49% less fit than P0. In summary, triclosan exposure of S. aureus produced SCVs in 4/6 test bacteria, with decreased triclosan susceptibility but with generally increased antibiotic susceptibility. An SCV derived from S. aureus ATCC 6538 showed reduced competitive fitness, potentially due to impaired cell division. In this SCV, increased FabI expression could account for reduced triclosan susceptibility, while IsaA may be upregulated in response to cell division defects. PMID:26033734

  16. Ocean acidification affects competition for space: projections of community structure using cellular automata.

    PubMed

    McCoy, Sophie J; Allesina, Stefano; Pfister, Catherine A

    2016-03-16

    Historical ecological datasets from a coastal marine community of crustose coralline algae (CCA) enabled the documentation of ecological changes in this community over 30 years in the Northeast Pacific. Data on competitive interactions obtained from field surveys showed concordance between the 1980s and 2013, yet also revealed a reduction in how strongly species interact. Here, we extend these empirical findings with a cellular automaton model to forecast ecological dynamics. Our model suggests the emergence of a new dominant competitor in a global change scenario, with a reduced role of herbivory pressure, or trophic control, in regulating competition among CCA. Ocean acidification, due to its energetic demands, may now instead play this role in mediating competitive interactions and thereby promote species diversity within this guild. PMID:26936244

  17. Cellular Intrinsic Mechanism Affecting the Outcome of AML Treated with Ara-C in a Syngeneic Mouse Model

    PubMed Central

    Tan, Dongming; Su, Guangsong; Zheng, Yanwen; He, Chao; Mao, Zhengwei J.; Singleton, Timothy P.; Yin, Bin

    2014-01-01

    The mechanisms underlying acute myeloid leukemia (AML) treatment failure are not clear. Here, we established a mouse model of AML by syngeneic transplantation of BXH-2 derived myeloid leukemic cells and developed an efficacious Ara-C-based regimen for treatment of these mice. We proved that leukemic cell load was correlated with survival. We also demonstrated that the susceptibility of leukemia cells to Ara-C could significantly affect the survival. To examine the molecular alterations in cells with different sensitivity, genome-wide expression of the leukemic cells was profiled, revealing that overall 366 and 212 genes became upregulated or downregulated, respectively, in the resistant cells. Many of these genes are involved in the regulation of cell cycle, cellular proliferation, and apoptosis. Some of them were further validated by quantitative PCR. Interestingly, the Ara-C resistant cells retained the sensitivity to ABT-737, an inhibitor of anti-apoptosis proteins, and treatment with ABT-737 prolonged the life span of mice engrafted with resistant cells. These results suggest that leukemic load and intrinsic cellular resistance can affect the outcome of AML treated with Ara-C. Incorporation of apoptosis inhibitors, such as ABT-737, into traditional cytotoxic regimens merits consideration for the treatment of AML in a subset of patients with resistance to Ara-C. This work provided direct in vivo evidence that leukemic load and intrinsic cellular resistance can affect the outcome of AML treated with Ara-C, suggesting that incorporation of apoptosis inhibitors into traditional cytotoxic regimens merits consideration for the treatment of AML in a subset of patients with resistance to Ara-C. PMID:25314317

  18. Grazer-induced morphological defense in Scenedesmus obliquus is affected by competition against Microcystis aeruginosa

    PubMed Central

    Zhu, Xuexia; Wang, Jun; Lu, Yichun; Chen, Qinwen; Yang, Zhou

    2015-01-01

    The green alga Scenedesmus is known for its phenotypic plasticity in response to grazing risk. However, the benefits of colony formation induced by infochemicals from zooplankton should come with costs. That is, a tradeoff in benefit-to-cost ratios is likely under complex environmental conditions. In this study, we hypothesized that the coexistence of Scenedesmus and its competitors decreases the formation of anti-grazer colonies in Scenedesmus. Results demonstrated that the presence of a competitor Microcystis aeruginosa inhibited inducible defensive colony formation of Scenedesmus obliquus, and the established defensive colonies negatively affected the competitive ability of S. obliquus. The proportion of induced defensive colonies in cultures was dependent on the relative abundance of competitors. Under low competition intensity, large amount of eight-celled colonies were formed but at the cost of decreased competitive inhibition on M. aeruginosa. By contrast, defensive colony formation of S. obliquus slacked in the presence of high competition intensity to maintain a high displacement rate (competitive ability). In conclusion, S. obliquus exhibited different responses to potential grazing pressure under different intensities of competition, i.e., Scenedesmus morphological response to grazing infochemicals was affected by competition against Microcystis. PMID:26224387

  19. Fetal radiofrequency radiation exposure from 800-1900 mhz-rated cellular telephones affects neurodevelopment and behavior in mice.

    PubMed

    Aldad, Tamir S; Gan, Geliang; Gao, Xiao-Bing; Taylor, Hugh S

    2012-01-01

    Neurobehavioral disorders are increasingly prevalent in children, however their etiology is not well understood. An association between prenatal cellular telephone use and hyperactivity in children has been postulated, yet the direct effects of radiofrequency radiation exposure on neurodevelopment remain unknown. Here we used a mouse model to demonstrate that in-utero radiofrequency exposure from cellular telephones does affect adult behavior. Mice exposed in-utero were hyperactive and had impaired memory as determined using the object recognition, light/dark box and step-down assays. Whole cell patch clamp recordings of miniature excitatory postsynaptic currents (mEPSCs) revealed that these behavioral changes were due to altered neuronal developmental programming. Exposed mice had dose-responsive impaired glutamatergic synaptic transmission onto layer V pyramidal neurons of the prefrontal cortex. We present the first experimental evidence of neuropathology due to in-utero cellular telephone radiation. Further experiments are needed in humans or non-human primates to determine the risk of exposure during pregnancy. PMID:22428084

  20. Protein source and choice of anticoagulant decisively affect nanoparticle protein corona and cellular uptake

    NASA Astrophysics Data System (ADS)

    Schöttler, S.; Klein, Katja; Landfester, K.; Mailänder, V.

    2016-03-01

    Protein adsorption on nanoparticles has been a focus of the field of nanocarrier research in the past few years and more and more papers are dealing with increasingly detailed lists of proteins adsorbed to a plethora of nanocarriers. While there is an urgent need to understand the influence of this protein corona on nanocarriers' interactions with cells the strong impact of the protein source on corona formation and the consequence for interaction with different cell types are factors that are regularly neglected, but should be taken into account for a meaningful analysis. In this study, the importance of the choice of protein source used for in vitro protein corona analysis is concisely investigated. Major and decisive differences in cellular uptake of a polystyrene nanoparticle incubated in fetal bovine serum, human serum, human citrate and heparin plasma are reported. Furthermore, the protein compositions are determined for coronas formed in the respective incubation media. A strong influence of heparin, which is used as an anticoagulant for plasma generation, on cell interaction is demonstrated. While heparin enhances the uptake into macrophages, it prevents internalization into HeLa cells. Taken together we can give the recommendation that human plasma anticoagulated with citrate seems to give the most relevant results for in vitro studies of nanoparticle uptake.Protein adsorption on nanoparticles has been a focus of the field of nanocarrier research in the past few years and more and more papers are dealing with increasingly detailed lists of proteins adsorbed to a plethora of nanocarriers. While there is an urgent need to understand the influence of this protein corona on nanocarriers' interactions with cells the strong impact of the protein source on corona formation and the consequence for interaction with different cell types are factors that are regularly neglected, but should be taken into account for a meaningful analysis. In this study, the importance

  1. Protein source and choice of anticoagulant decisively affect nanoparticle protein corona and cellular uptake.

    PubMed

    Schöttler, S; Klein, Katja; Landfester, K; Mailänder, V

    2016-03-14

    Protein adsorption on nanoparticles has been a focus of the field of nanocarrier research in the past few years and more and more papers are dealing with increasingly detailed lists of proteins adsorbed to a plethora of nanocarriers. While there is an urgent need to understand the influence of this protein corona on nanocarriers' interactions with cells the strong impact of the protein source on corona formation and the consequence for interaction with different cell types are factors that are regularly neglected, but should be taken into account for a meaningful analysis. In this study, the importance of the choice of protein source used for in vitro protein corona analysis is concisely investigated. Major and decisive differences in cellular uptake of a polystyrene nanoparticle incubated in fetal bovine serum, human serum, human citrate and heparin plasma are reported. Furthermore, the protein compositions are determined for coronas formed in the respective incubation media. A strong influence of heparin, which is used as an anticoagulant for plasma generation, on cell interaction is demonstrated. While heparin enhances the uptake into macrophages, it prevents internalization into HeLa cells. Taken together we can give the recommendation that human plasma anticoagulated with citrate seems to give the most relevant results for in vitro studies of nanoparticle uptake. PMID:26804616

  2. Altered lysosomal positioning affects lysosomal functions in a cellular model of Huntington's disease.

    PubMed

    Erie, Christine; Sacino, Matthew; Houle, Lauren; Lu, Michael L; Wei, Jianning

    2015-08-01

    Huntington's disease (HD) is a hereditary and devastating neurodegenerative disorder caused by a mutation in the huntingtin protein. Understanding the functions of normal and mutant huntingtin protein is the key to revealing the pathogenesis of HD and developing therapeutic targets. Huntingtin plays an important role in vesicular and organelle trafficking. Lysosomes are dynamic organelles that integrate several degradative pathways and regulate the activity of mammalian target of rapamycin complex 1 (mTORC1). In the present study, we found that the perinuclear accumulation of lysosomes was increased in a cellular model of HD derived from HD knock-in mice and primary fibroblasts from an HD patient. This perinuclear lysosomal accumulation could be reversed when normal huntingtin was overexpressed in HD cells. When we further investigated the functional significance of the increased perinuclear lysosomal accumulation in HD cells, we demonstrated that basal mTORC1 activity was increased in HD cells. In addition, autophagic influx was also increased in HD cells in response to serum deprivation, which leads to premature fusion of lysosomes with autophagosomes. Taken together, our data suggest that the increased perinuclear accumulation of lysosomes may play an important role in HD pathogenesis by altering lysosomal-dependent functions. PMID:25997742

  3. Modification of Cellular Cholesterol Content Affects Traction Force, Adhesion and Cell Spreading

    PubMed Central

    Norman, Leann L.; Oetama, Ratna J.; Dembo, Micah; Byfield, F.; Hammer, Daniel A.; Levitan, Irena; Aranda-Espinoza, Helim

    2011-01-01

    Cellular cholesterol is a critical component of the plasma membrane, and plays a key role in determining the physical properties of the lipid bilayer, such as elasticity, viscosity, and permeability. Surprisingly, it has been shown that cholesterol depletion increases cell stiffness, not due to plasma membrane stiffening, but rather, due to the interaction between the actin cytoskeleton and the plasma membrane. This indicates that traction stresses of the acto-myosin complex likely increase during cholesterol depletion. Here we use force traction microscopy to quantify the forces individual cells are exerting on the substrate, and total internal reflection fluorescence microscopy as well as interference reflection microscopy to observe cell–substrate adhesion and spreading. We show that single cells depleted of cholesterol produce larger traction forces and have large focal adhesions compared to untreated or cholesterol-enriched cells. Cholesterol depletion also causes a decrease in adhesion area for both single cells and monolayers. Spreading experiments illustrate a decrease in spreading area for cholesterol-depleted cells, and no effect on cholesterol-enriched cells. These results demonstrate that cholesterol plays an important role in controlling and regulating the cell–substrate interactions through the actin–plasma membrane complex, cell–cell adhesion, and spreading. PMID:21461187

  4. Histological Lesions and Cellular Response in the Skin of Alpine Chamois (Rupicapra r. rupicapra) Spontaneously Affected by Sarcoptic Mange

    PubMed Central

    Salvadori, Claudia; Lazzarotti, Camilla; Trogu, Tiziana; Lanfranchi, Paolo

    2016-01-01

    Population dynamics of chamois (genus Rupicapra, subfamily Caprinae) can be influenced by infectious diseases epizootics, of which sarcoptic mange is probably the most severe in the Alpine chamois (Rupicapra rupicapra rupicapra). In this study, skin lesions and cellular inflammatory infiltrates were characterized in 44 Alpine chamois affected by sarcoptic mange. Dermal cellular responses were evaluated in comparison with chamois affected by trombiculosis and controls. In both sarcoptic mange and trombiculosis, a significantly increase of eosinophils, mast cells, T and B lymphocytes, and macrophages was detected. Moreover, in sarcoptic mange significant higher numbers of T lymphocytes and macrophages compared to trombiculosis were observed. Lesions in sarcoptic mange were classified in three grades, according to crusts thickness, correlated with mite counts. Grade 3 represented the most severe form with crust thickness more than 3.5 mm, high number of mites, and severe parakeratosis with diffuse bacteria. Evidence of immediate and delayed hypersensitivity was detected in all three forms associated with diffuse severe epidermal hyperplasia. In grade 3, a significant increase of B lymphocytes was evident compared to grades 1 and 2, while eosinophil counts were significantly higher than in grade 1, but lower than in grade 2 lesions. An involvement of nonprotective Th2 immune response could in part account for severe lesions of grade 3. PMID:27403422

  5. Mutations in MCT8 in patients with Allan-Herndon-Dudley-syndrome affecting its cellular distribution.

    PubMed

    Kersseboom, Simone; Kremers, Gert-Jan; Friesema, Edith C H; Visser, W Edward; Klootwijk, Wim; Peeters, Robin P; Visser, Theo J

    2013-05-01

    Monocarboxylate transporter 8 (MCT8) is a thyroid hormone (TH)-specific transporter. Mutations in the MCT8 gene are associated with Allan-Herndon-Dudley Syndrome (AHDS), consisting of severe psychomotor retardation and disturbed TH parameters. To study the functional consequences of different MCT8 mutations in detail, we combined functional analysis in different cell types with live-cell imaging of the cellular distribution of seven mutations that we identified in patients with AHDS. We used two cell models to study the mutations in vitro: 1) transiently transfected COS1 and JEG3 cells, and 2) stably transfected Flp-in 293 cells expressing a MCT8-cyan fluorescent protein construct. All seven mutants were expressed at the protein level and showed a defect in T3 and T4 transport in uptake and metabolism studies. Three mutants (G282C, P537L, and G558D) had residual uptake activity in Flp-in 293 and COS1 cells, but not in JEG3 cells. Four mutants (G221R, P321L, D453V, P537L) were expressed at the plasma membrane. The mobility in the plasma membrane of P537L was similar to WT, but the mobility of P321L was altered. The other mutants studied (insV236, G282C, G558D) were predominantly localized in the endoplasmic reticulum. In essence, loss of function by MCT8 mutations can be divided in two groups: mutations that result in partial or complete loss of transport activity (G221R, P321L, D453V, P537L) and mutations that mainly disturb protein expression and trafficking (insV236, G282C, G558D). The cell type-dependent results suggest that MCT8 mutations in AHDS patients may have tissue-specific effects on TH transport probably caused by tissue-specific expression of yet unknown MCT8-interacting proteins. PMID:23550058

  6. Hippocampal morphology is differentially affected by reproductive experience in the mother.

    PubMed

    Pawluski, Jodi L; Galea, Liisa A M

    2006-01-01

    Pregnancy and mothering result in a number of hormonal, neurological, and behavioral changes that are necessary to ensure reproductive success. With subsequent reproductive experience (multiparity and mothering), further neurological and behavioral changes may result. Recent research has shown that previous motherhood enhances both hippocampus-dependent learning and memory and long-term potentiation (LTP); together with decreases in hippocampus volumes during pregnancy it is suggested that the hippocampus is affected by pregnancy and/or mothering. The present experiment aimed to investigate the effect of reproductive experience (nulli, primi-, and multiparity and mothering) on dendritic morphology in the CA1 and CA3 regions of the hippocampus. Brains were stained with a modified version of the single-section Golgi impregnation technique, and dendritic length, number of branch points, and spine density was analyzed for apical and basal regions of CA1 and CA3 pyramidal neurons. Primiparity and/or mothering resulted in dendritic remodeling in both the CA1 and CA3 hippocampal regions, and multiparity resulted in enhanced spine density in the basal CA1 region, which was positively correlated with number of male pups in a litter. These findings point to the effect of reproductive experience and offspring on plasticity in the hippocampus, an area not traditionally associated with motherhood. PMID:16216005

  7. MeCP2 Affects Skeletal Muscle Growth and Morphology through Non Cell-Autonomous Mechanisms

    PubMed Central

    Galli, Francesco; Tirone, Mario; Bellini, Elisa; Campana, Lara; Kilstrup-Nielsen, Charlotte; Rovere-Querini, Patrizia; Brunelli, Silvia; Landsberger, Nicoletta

    2015-01-01

    Rett syndrome (RTT) is an autism spectrum disorder mainly caused by mutations in the X-linked MECP2 gene and affecting roughly 1 out of 10.000 born girls. Symptoms range in severity and include stereotypical movement, lack of spoken language, seizures, ataxia and severe intellectual disability. Notably, muscle tone is generally abnormal in RTT girls and women and the Mecp2-null mouse model constitutively reflects this disease feature. We hypothesized that MeCP2 in muscle might physiologically contribute to its development and/or homeostasis, and conversely its defects in RTT might alter the tissue integrity or function. We show here that a disorganized architecture, with hypotrophic fibres and tissue fibrosis, characterizes skeletal muscles retrieved from Mecp2-null mice. Alterations of the IGF-1/Akt/mTOR pathway accompany the muscle phenotype. A conditional mouse model selectively depleted of Mecp2 in skeletal muscles is characterized by healthy muscles that are morphologically and molecularly indistinguishable from those of wild-type mice raising the possibility that hypotonia in RTT is mainly, if not exclusively, mediated by non-cell autonomous effects. Our results suggest that defects in paracrine/endocrine signaling and, in particular, in the GH/IGF axis appear as the major cause of the observed muscular defects. Remarkably, this is the first study describing the selective deletion of Mecp2 outside the brain. Similar future studies will permit to unambiguously define the direct impact of MeCP2 on tissue dysfunctions. PMID:26098633

  8. MeCP2 Affects Skeletal Muscle Growth and Morphology through Non Cell-Autonomous Mechanisms.

    PubMed

    Conti, Valentina; Gandaglia, Anna; Galli, Francesco; Tirone, Mario; Bellini, Elisa; Campana, Lara; Kilstrup-Nielsen, Charlotte; Rovere-Querini, Patrizia; Brunelli, Silvia; Landsberger, Nicoletta

    2015-01-01

    Rett syndrome (RTT) is an autism spectrum disorder mainly caused by mutations in the X-linked MECP2 gene and affecting roughly 1 out of 10.000 born girls. Symptoms range in severity and include stereotypical movement, lack of spoken language, seizures, ataxia and severe intellectual disability. Notably, muscle tone is generally abnormal in RTT girls and women and the Mecp2-null mouse model constitutively reflects this disease feature. We hypothesized that MeCP2 in muscle might physiologically contribute to its development and/or homeostasis, and conversely its defects in RTT might alter the tissue integrity or function. We show here that a disorganized architecture, with hypotrophic fibres and tissue fibrosis, characterizes skeletal muscles retrieved from Mecp2-null mice. Alterations of the IGF-1/Akt/mTOR pathway accompany the muscle phenotype. A conditional mouse model selectively depleted of Mecp2 in skeletal muscles is characterized by healthy muscles that are morphologically and molecularly indistinguishable from those of wild-type mice raising the possibility that hypotonia in RTT is mainly, if not exclusively, mediated by non-cell autonomous effects. Our results suggest that defects in paracrine/endocrine signaling and, in particular, in the GH/IGF axis appear as the major cause of the observed muscular defects. Remarkably, this is the first study describing the selective deletion of Mecp2 outside the brain. Similar future studies will permit to unambiguously define the direct impact of MeCP2 on tissue dysfunctions. PMID:26098633

  9. Cellular and molecular mechanisms affecting tumour radiosensitivity : An in vitro study

    NASA Astrophysics Data System (ADS)

    Power, Olive Mary

    The response of tumour cells in vitro to ionising radiation can, to a certain extent, predict the response of tumours to various radiotherapy treatment modalities. This thesis considers some of the factors known to be involved in the radiation response of human tumour cells in vitro. These parameters include radiation-induced cell-cycle perturbations, apoptosis and DNA damage repair. A panel of eight human tumour cell lines with markedly differing radiosensitivities were assessed in order to determine the key factors governing their radiation response. A wide range of doses spanning both the low dose region (0-2 Gy and 0-5 Gy) and the clinically relevant region (1-4 Gy) were used to determine whether differences in responses could distinguish cells which were radiosensitive or resistant. Ionising radiation produced a cell cycle delay in all cell lines in one or both of the cellular checkpoints. A Gl/S delay was detected in those cell lines that expressed wild-type p53, and the duration of this delay appeared to be directly related to the level of constitutive protein. p53 protein stabilisation was observed after 4 h, even at doses of 0-2 Gy, although a Gl/S delay was only detectable at higher doses. There was no direct relationship between p53 status and survival although wild-type p53 expression was more prevalent in the radiosensitive cell lines (3/4 sensitives are wild-type versus 2/4 resistants). A G2/M delay could only be detected at doses of > 1 Gy. This delay appeared to be dose independent in the resistant cell lines, suggesting a threshold dose of IGy, above which no further effect is observed. A radiation-induced reduction of cyclin B1 protein was observed in all cell lines implicating this protein in the induction of a G2/M delay. The duration of G2/M delay was significantly longer in the radiosensitive cell lines at 4 Gy (7-20 h versus 4-6 h at 4 Gy). The proportion of cells that exited the G2/M block and re-entered GO/G1 phase was also significantly

  10. Modeling physicochemical interactions affecting in vitro cellular dosimetry of engineered nanomaterials: application to nanosilver

    PubMed Central

    Mukherjee, Dwaipayan; Leo, Bey Fen; Royce, Steven G.; Porter, Alexandra E.; Ryan, Mary P.; Schwander, Stephan; Chung, Kian Fan; Tetley, Teresa D.; Zhang, Junfeng; Georgopoulos, Panos G.

    2014-01-01

    Engineered nanomaterials (ENMs) possess unique characteristics affecting their interactions in biological media and biological tissues. Systematic investigation of the effects of particle properties on biological toxicity requires a comprehensive modeling framework which can be used to predict ENM particokinetics in a variety of media. The Agglomeration-diffusion-sedimentation-reaction model (ADSRM) described here is stochastic, using a direct simulation Monte Carlo method to study the evolution of nanoparticles in biological media, as they interact with each other and with the media over time. Nanoparticle diffusion, gravitational settling, agglomeration, and dissolution are treated in a mechanistic manner with focus on silver ENMs (AgNPs). The ADSRM model utilizes particle properties such as size, density, zeta potential, and coating material, along with medium properties like density, viscosity, ionic strength, and pH, to model evolving patterns in a population of ENMs along with their interaction with associated ions and molecules. The model predictions for agglomeration and dissolution are compared with in vitro measurements for various types of ENMs, coating materials, and incubation media, and are found to be overall consistent with measurements. The model has been implemented for an in vitro case in cell culture systems to inform in vitro dosimetry for toxicology studies, and can be directly extended to other biological systems, including in vivo tissue subsystems by suitably modifying system geometry. PMID:25598696

  11. Mutations affecting sensitivity of the cellular slime mold Dictyostelium discoideum to DNA-damaging agents.

    PubMed

    Bronner, C E; Welker, D L; Deering, R A

    1992-09-01

    We describe 22 new mutants of D. discoideum that are sensitive to DNA damage. These mutants were isolated on the basis of sensitivity to either temperature, gamma-rays, or 4-nitroquinolone-1-oxide (4NQO). The doses of gamma-rays, ultraviolet light (UV), and 4NQO required to reduce the survival of colony-forming ability of these mutants to 10% (D10) range from 2% to 100% of the D10s for the nonmutant, parent strains. For most of the mutants, those which are very sensitive to one agent are very sensitive to all agents tested and those which are moderately sensitive to one agent, are moderately sensitive to all agents tested. One mutant is sensitive only to 4NQO. Linkage relationships have been examined for 13 of these mutants. This linkage information was used to design complementation tests to determine allelism with previously characterized complementation groups affecting sensitivity to radiation. 4 of the new mutants fall within previously identified complementation groups and 3 new complementation groups have been identified (radJ, radK and radL). Other new loci probably also exist among these new mutants. This brings the number of characterized mutants of D. discoideum which are sensitive to DNA-damaging agents to 33 and the number of assigned complementation groups to 11. PMID:1380652

  12. Telomere protein RAP1 levels are affected by cellular aging and oxidative stress

    PubMed Central

    Swanson, Mark J.; Baribault, Michelle E.; Israel, Joanna N.; Bae, Nancy S.

    2016-01-01

    Telomeres are important for maintaining the integrity of the genome through the action of the shelterin complex. Previous studies indicted that the length of the telomere did not have an effect on the amount of the shelterin subunits; however, those experiments were performed using immortalized cells with stable telomere lengths. The interest of the present study was to observe how decreasing telomere lengths over successive generations would affect the shelterin subunits. As neonatal human dermal fibroblasts aged and their telomeres became shorter, the levels of the telomere-binding protein telomeric repeat factor 2 (TRF2) decreased significantly. By contrast, the levels of one of its binding partners, repressor/activator protein 1 (RAP1), decreased to a lesser extent than would be expected from the decrease in TRF2. Other subunits, TERF1-interacting nuclear factor 2 and protection of telomeres protein 1, remained stable. The decrease in RAP1 in the older cells occurred in the nuclear and cytoplasmic fractions. Hydrogen peroxide (H2O2) stress was used as an artificial means of aging in the cells, and this resulted in RAP1 levels decreasing, but the effect was only observed in the nuclear portion. Similar results were obtained using U251 glioblastoma cells treated with H2O2 or grown in serum-depleted medium. The present findings indicate that TRF2 and RAP1 levels decrease as fibroblasts naturally age. RAP1 remains more stable compared to TRF2. RAP1 also responds to oxidative stress, but the response is different to that observed in aging. PMID:27446538

  13. Reduction of Cellular Expression Levels Is a Common Feature of Functionally Affected Pendrin (SLC26A4) Protein Variants

    PubMed Central

    de Moraes, Vanessa C S; Bernardinelli, Emanuele; Zocal, Nathalia; Fernandez, Jhonathan A; Nofziger, Charity; Castilho, Arthur M; Sartorato, Edi L; Paulmichl, Markus; Dossena, Silvia

    2016-01-01

    Sequence alterations in the pendrin gene (SLC26A4) leading to functionally affected protein variants are frequently involved in the pathogenesis of syndromic and nonsyndromic deafness. Considering the high number of SLC26A4 sequence alterations reported to date, discriminating between functionally affected and unaffected pendrin protein variants is essential in contributing to determine the genetic cause of deafness in a given patient. In addition, identifying molecular features common to the functionally affected protein variants can be extremely useful to design future molecule-directed therapeutic approaches. Here we show the functional and molecular characterization of six previously uncharacterized pendrin protein variants found in a cohort of 58 Brazilian deaf patients. Two variants (p.T193I and p.L445W) were undetectable in the plasma membrane, completely retained in the endoplasmic reticulum and showed no transport function; four (p.P142L, p.G149R, p.C282Y and p.Q413R) showed reduced function and significant, although heterogeneous, expression levels in the plasma membrane. Importantly, total expression levels of all of the functionally affected protein variants were significantly reduced with respect to the wild-type and a fully functional variant (p.R776C), regardless of their subcellular localization. Interestingly, reduction of expression may also reduce the transport activity of variants with an intrinsic gain of function (p.Q413R). As reduction of overall cellular abundance was identified as a common molecular feature of pendrin variants with affected function, the identification of strategies to prevent reduction in expression levels may represent a crucial step of potential future therapeutic interventions aimed at restoring the transport activity of dysfunctional pendrin variants. PMID:26752218

  14. Cellular basis of morphological variation and temperature-related plasticity in Drosophila melanogaster strains with divergent wing shapes.

    PubMed

    Torquato, Libéria Souza; Mattos, Daniel; Matta, Bruna Palma; Bitner-Mathé, Blanche Christine

    2014-12-01

    Organ shape evolves through cross-generational changes in developmental patterns at cellular and/or tissue levels that ultimately alter tissue dimensions and final adult proportions. Here, we investigated the cellular basis of an artificially selected divergence in the outline shape of Drosophila melanogaster wings, by comparing flies with elongated or rounded wing shapes but with remarkably similar wing sizes. We also tested whether cellular plasticity in response to developmental temperature was altered by such selection. Results show that variation in cellular traits is associated with wing shape differences, and that cell number may play an important role in wing shape response to selection. Regarding the effects of developmental temperature, a size-related plastic response was observed, in that flies reared at 16 °C developed larger wings with larger and more numerous cells across all intervein regions relative to flies reared at 25 °C. Nevertheless, no conclusive indication of altered phenotypic plasticity was found between selection strains for any wing or cellular trait. We also described how cell area is distributed across different intervein regions. It follows that cell area tends to decrease along the anterior wing compartment and increase along the posterior one. Remarkably, such pattern was observed not only in the selected strains but also in the natural baseline population, suggesting that it might be canalized during development and was not altered by the intense program of artificial selection for divergent wing shapes. PMID:25326715

  15. The transcriptional activities and cellular localization of the human estrogen receptor alpha are affected by the synonymous Ala87 mutation.

    PubMed

    Fernández-Calero, Tamara; Astrada, Soledad; Alberti, Alvaro; Horjales, Sofía; Arnal, Jean Francois; Rovira, Carlos; Bollati-Fogolín, Mariela; Flouriot, Gilles; Marin, Mónica

    2014-09-01

    Until recently, synonymous mutations (which do not change amino acids) have been much neglected. Some evidence suggests that this kind of mutations could affect mRNA secondary structure or stability, translation kinetics and protein structure. To explore deeper the role of synonymous mutations, we studied their consequence on the functional activity of the estrogen receptor alpha (ERα). The ERα is a ligand-inducible transcription factor that orchestrates pleiotropic cellular effects, at both genomic and non-genomic levels in response to estrogens. In this work we analyzed in transient transfection experiments, the activity of ERα carrying the synonymous mutation Ala87, a polymorphism involving about 5-10% of the population. In comparison to the wild type receptor, our results show that ERαA87 mutation reduces the transactivation efficiency of ERα on an ERE reporter gene while its expression level remains similar. This mutation enhances 4-OHT-induced transactivation of ERα on an AP1 reporter gene. Finally, the mutation affects the subcellular localization of ERα in a cell type specific manner. It enhances the cytoplasmic location of ERα without significant changes in non-genomic effects of E2. The functional alteration of the ERαA87 determined in this work highlights the relevance of synonymous mutations for biomedical and pharmacological points of view. PMID:24607813

  16. Alpha-Synuclein affects neurite morphology, autophagy, vesicle transport and axonal degeneration in CNS neurons

    PubMed Central

    Koch, J C; Bitow, F; Haack, J; d'Hedouville, Z; Zhang, J-N; Tönges, L; Michel, U; Oliveira, L M A; Jovin, T M; Liman, J; Tatenhorst, L; Bähr, M; Lingor, P

    2015-01-01

    Many neuropathological and experimental studies suggest that the degeneration of dopaminergic terminals and axons precedes the demise of dopaminergic neurons in the substantia nigra, which finally results in the clinical symptoms of Parkinson disease (PD). The mechanisms underlying this early axonal degeneration are, however, still poorly understood. Here, we examined the effects of overexpression of human wildtype alpha-synuclein (αSyn-WT), a protein associated with PD, and its mutant variants αSyn-A30P and -A53T on neurite morphology and functional parameters in rat primary midbrain neurons (PMN). Moreover, axonal degeneration after overexpression of αSyn-WT and -A30P was analyzed by live imaging in the rat optic nerve in vivo. We found that overexpression of αSyn-WT and of its mutants A30P and A53T impaired neurite outgrowth of PMN and affected neurite branching assessed by Sholl analysis in a variant-dependent manner. Surprisingly, the number of primary neurites per neuron was increased in neurons transfected with αSyn. Axonal vesicle transport was examined by live imaging of PMN co-transfected with EGFP-labeled synaptophysin. Overexpression of all αSyn variants significantly decreased the number of motile vesicles and decelerated vesicle transport compared with control. Macroautophagic flux in PMN was enhanced by αSyn-WT and -A53T but not by αSyn-A30P. Correspondingly, colocalization of αSyn and the autophagy marker LC3 was reduced for αSyn-A30P compared with the other αSyn variants. The number of mitochondria colocalizing with LC3 as a marker for mitophagy did not differ among the groups. In the rat optic nerve, both αSyn-WT and -A30P accelerated kinetics of acute axonal degeneration following crush lesion as analyzed by in vivo live imaging. We conclude that αSyn overexpression impairs neurite outgrowth and augments axonal degeneration, whereas axonal vesicle transport and autophagy are severely altered. PMID:26158517

  17. Phenomena affecting morphology of microporous poly(acrylonitrile) prepared via phase separation from solution

    SciTech Connect

    Legasse, R.R.; Weagley, R.J.; Leslie, P.K.; Schneider, D.A.

    1990-01-01

    This paper is concerned with controlling the morphology of microporous polymers prepared via thermal demixing of solutions. 2 wt % solutions of poly(acrylonitrile) in maleic anhydride, a poor solvent, are first cooled to produce separated polymer-rich and solvent-rich phases. Removing the solvent by freeze drying then produces a microporous material having a density of 33 mg/cm{sup 3}, a void fraction of 97%, and a pore size of about 10 {mu}m. We find that the morphology cannot be explained by existing models, which focus on phase diagrams and kinetics of phase transformations during cooling of the solution. In conflict with those models, we find that two radically different morphologies can be produced even when the polymer concentration and cooling path are held strictly constant. A hypothesis that polymer degradation causes the different morphologies is not supported by GPC, {sup 13}C NMR, and FTIR experiments. Instead, we offer evidence that the different microporous morphologies are caused by different polymer conformations in solutions having the same concentration and temperature. 11 refs., 3 figs.

  18. Insights into Embryo Defenses of the Invasive Apple Snail Pomacea canaliculata: Egg Mass Ingestion Affects Rat Intestine Morphology and Growth

    PubMed Central

    Gimeno, Eduardo J.; Heras, Horacio

    2014-01-01

    Background The spread of the invasive snail Pomacea canaliculata is expanding the rat lungworm disease beyond its native range. Their toxic eggs have virtually no predators and unusual defenses including a neurotoxic lectin and a proteinase inhibitor, presumably advertised by a warning coloration. We explored the effect of egg perivitellin fluid (PVF) ingestion on the rat small intestine morphology and physiology. Methodology/Principal Findings Through a combination of biochemical, histochemical, histopathological, scanning electron microscopy, cell culture and feeding experiments, we analyzed intestinal morphology, growth rate, hemaglutinating activity, cytotoxicity and cell proliferation after oral administration of PVF to rats. PVF adversely affects small intestine metabolism and morphology and consequently the standard growth rate, presumably by lectin-like proteins, as suggested by PVF hemaglutinating activity and its cytotoxic effect on Caco-2 cell culture. Short-term effects of ingested PVF were studied in growing rats. PVF-supplemented diet induced the appearance of shorter and wider villi as well as fused villi. This was associated with changes in glycoconjugate expression, increased cell proliferation at crypt base, and hypertrophic mucosal growth. This resulted in a decreased absorptive surface after 3 days of treatment and a diminished rat growth rate that reverted to normal after the fourth day of treatment. Longer exposure to PVF induced a time-dependent lengthening of the small intestine while switching to a control diet restored intestine length and morphology after 4 days. Conclusions/Significance Ingestion of PVF rapidly limits the ability of potential predators to absorb nutrients by inducing large, reversible changes in intestinal morphology and growth rate. The occurrence of toxins that affect intestinal morphology and absorption is a strategy against predation not recognized among animals before. Remarkably, this defense is rather similar to

  19. Morphological characterization of keratoconus-affected human corneas by SHG imaging and correlation analysis

    NASA Astrophysics Data System (ADS)

    Mercatelli, R.; Ratto, F.; Tatini, F.; Rossi, F.; Menabuoni, L.; Nicoletti, R.; Pini, R.; Pavone, Frederick; Cicchi, R.

    2016-03-01

    Keratoconus is an ophthalmic disease in which the cornea acquires an abnormal conical shape that prevents the correct focusing on the retina, causing visual impairment. The late diagnosis of keratoconus is among the principal causes of corneal transplantation surgery. In this study, we characterize the morphology of keratoconic corneas by means of the correlation of SHG images, finding that keratoconus can be diagnosed by analyzing the inclination of lamellae below Bowman's membrane. In addition, imaging performed with both sagittal and "en face" geometry demonstrated that this morphological features can be highlighted both ex vivo and in vivo.

  20. Glufosinate does not affect floral morphology and pollen viability in glufosinate-resistant cotton (Gossypium hirsutum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted to determine whether glufosinate treatments to glufosinate-resistant cotton caused changes in floral morphology, pollen viability, and seed set. Four glufosinate treatments were included: (1) glufosinate applied postemergence over the top (POST) at the four-leaf stage, (2) glu...

  1. Cellular localization of long non-coding RNAs affects silencing by RNAi more than by antisense oligonucleotides.

    PubMed

    Lennox, Kim A; Behlke, Mark A

    2016-01-29

    Thousands of long non-coding RNAs (lncRNAs) have been identified in mammalian cells. Some have important functions and their dysregulation can contribute to a variety of disease states. However, most lncRNAs have not been functionally characterized. Complicating their study, lncRNAs have widely varying subcellular distributions: some reside predominantly in the nucleus, the cytoplasm or in both compartments. One method to query function is to suppress expression and examine the resulting phenotype. Methods to suppress expression of mRNAs include antisense oligonucleotides (ASOs) and RNA interference (RNAi). Antisense and RNAi-based gene-knockdown methods vary in efficacy between different cellular compartments. It is not known if this affects their ability to suppress lncRNAs. To address whether localization of the lncRNA influences susceptibility to degradation by either ASOs or RNAi, nuclear lncRNAs (MALAT1 and NEAT1), cytoplasmic lncRNAs (DANCR and OIP5-AS1) and dual-localized lncRNAs (TUG1, CasC7 and HOTAIR) were compared for knockdown efficiency. We found that nuclear lncRNAs were more effectively suppressed using ASOs, cytoplasmic lncRNAs were more effectively suppressed using RNAi and dual-localized lncRNAs were suppressed using both methods. A mixed-modality approach combining ASOs and RNAi reagents improved knockdown efficacy, particularly for those lncRNAs that localize to both nuclear and cytoplasmic compartments. PMID:26578588

  2. Indomethacin induces cellular morphological change and migration via epithelial-mesenchymal transition in A549 human lung cancer cells: a novel cyclooxygenase-inhibition-independent effect.

    PubMed

    Kato, Tomoko; Fujino, Hiromichi; Oyama, Satomi; Kawashima, Tatsuo; Murayama, Toshihiko

    2011-12-01

    Levels of cyclooxygenase (COX)-2 and its metabolite prostaglandin E(2) (PGE(2)) are frequently increased in colon cancer and other cancers including lung cancer. Non-steroidal anti-inflammatory drugs are considered to have chemo-preventive effects on these diseases by reducing the biosynthesis of PGE(2) via their inhibition of COX-2. Although the COX-2/PGE(2) pathway may directly impact on lung carcinogenesis, some population-based cohort studies of NSAIDs showed no significant protective effects. In this study, using human non-small-cell lung cancer A549 cells, we examined the effects of indomethacin, a potent NSAID, on the growth and motility of lung cancer cells. Besides inhibiting PGE(2) production and cellular growth, indomethacin caused drastic morphological changes with a loss of stress fibers in a time- and dose-dependent manner. Interestingly, the change in cellular shape caused by indomethacin was not seen when the cells were treated with aspirin or diclofenac, two other NSAIDs, despite the concentrations used being sufficient to inhibit PGE(2) production. The indomethacin-induced morphological changes in A549 cells were accompanied by a reduction in levels of the adhesion molecule E-cadherin and a component of basal lamina, collagen IV, as well as an increase in the activity of a collagenase, matrix metalloprotease-9. Furthermore, indomethacin-induced shape changes resulted in enhanced motility via regulation of peroxisome proliferator-activated receptor γ. The dual effects of indomethacin, inhibition of cellular growth and enhancement of migration, would explain, to some extent, the difficulty in using this NSAID for lung cancer therapy. PMID:21840302

  3. Contractility as a global regulator of cellular morphology, velocity, and directionality in low-adhesive fibrillary micro-environments.

    PubMed

    Schuster, Simon L; Segerer, Felix J; Gegenfurtner, Florian A; Kick, Kerstin; Schreiber, Christoph; Albert, Max; Vollmar, Angelika M; Rädler, Joachim O; Zahler, Stefan

    2016-09-01

    Recent reports demonstrated that migration in fibrillary environments can be mimicked by spatial confinement achieved with micro-patterning [1]. Here we investigated whether a model system based on linearly structured surfaces allows to draw conclusions about migration of endothelial cells (ECs) in fibrillary 3D environments. We found that ECs on 3 μm wide tracks (termed as 1D) migrate less efficient in comparison to ECs on broader tracks in regard to velocity and directional persistence. The frequent changes of direction in ECs on narrow tracks are accompanied by pronounced cell rounding and membrane blebbing, while cells migrating with an elongated morphology display a single lamellipodium. This behavior is contractility-dependent as both modes can be provoked by manipulating activity of myosin II (blebbistatin or calyculin A, respectively). The comparison between 1D and 3D migrating cells revealed a striking similarity in actin architecture and in switching between two morphologies. ECs move more directed but slower upon inhibition of contractility in 1D and 3D, in contrast to 2D cell culture. We conclude that micro-patterning can be used to study morphological switches in a controlled manner with a prognostic value for 3D environments. Moreover, we identified blebbing as a new aspect of EC migration. PMID:27336186

  4. How Will Climate Change Affect Channel Morphology and Salmonid Habitat in Mountain Basins?

    NASA Astrophysics Data System (ADS)

    Buffington, J. M.; Goode, J.

    2010-12-01

    Riverine habitat for salmonids is intimately linked to channel morphology and fluvial processes (channel hydraulics, sediment transport and scour regime) which are, in turn, controlled by watershed hydrology and erosional processes that input sediment to the fluvial system. Climate change has the potential to alter the timing, magnitude, and style of sediment and water inputs to mountain rivers. Channel response to these changes may range from small-scale adjustments of channel characteristics (e.g., width, depth, grain size, scour depth) to larger-scale changes in channel type (e.g., metamorphosis from a pool-riffle channel to a plane-bed morphology). Identifying which parts of the river network will remain relatively stable in response to climate change, and which are likely to cross critical morphologic and scour thresholds is important for predicting effects on salmonid populations. Toward this end, a regime framework is presented for predicting the relative degree of morphologic stability and scour potential in different physiographic settings (different water and sediment regimes). Digital elevation models are used to explore the spatial distribution of these conditions and potential consequences for salmonid habitat across the landscape. Results suggest that the potential for scour and morphologic variability are strongly influenced by hydroclimate; snowmelt channels are relatively stable across floods of different magnitude, while rainfall-dominated channels are more variable and less stable. Transitional changes in hydrologic regime (mixed rain and snow) have the greatest potential for altering geomorphic conditions and salmonid habitat. However, the vulnerability of salmonids to climate-driven changes in scour regime depend on the species and its life history (i.e., depth to which eggs are buried and timing of incubation relative to scouring flows). Overall, the regime approach provides a useful first-order assessment of channel condition and response

  5. Nanoscale Roughness and Morphology Affect the IsoElectric Point of Titania Surfaces

    PubMed Central

    Borghi, Francesca; Vyas, Varun; Podestà, Alessandro; Milani, Paolo

    2013-01-01

    We report on the systematic investigation of the role of surface nanoscale roughness and morphology on the charging behaviour of nanostructured titania (TiO2) surfaces in aqueous solutions. IsoElectric Points (IEPs) of surfaces have been characterized by direct measurement of the electrostatic double layer interactions between titania surfaces and the micrometer-sized spherical silica probe of an atomic force microscope in NaCl aqueous electrolyte. The use of a colloidal probe provides well-defined interaction geometry and allows effectively probing the overall effect of nanoscale morphology. By using supersonic cluster beam deposition to fabricate nanostructured titania films, we achieved a quantitative control over the surface morphological parameters. We performed a systematical exploration of the electrical double layer properties in different interaction regimes characterized by different ratios of characteristic nanometric lengths of the system: the surface rms roughness Rq, the correlation length ξ and the Debye length λD. We observed a remarkable reduction by several pH units of IEP on rough nanostructured surfaces, with respect to flat crystalline rutile TiO2. In order to explain the observed behavior of IEP, we consider the roughness-induced self-overlap of the electrical double layers as a potential source of deviation from the trend expected for flat surfaces. PMID:23874708

  6. Motor Rotation Is Essential for the Formation of the Periplasmic Flagellar Ribbon, Cellular Morphology, and Borrelia burgdorferi Persistence within Ixodes scapularis Tick and Murine Hosts

    PubMed Central

    Sultan, Syed Z.; Sekar, Padmapriya; Zhao, Xiaowei; Manne, Akarsh; Liu, Jun; Wooten, R. Mark

    2015-01-01

    Borrelia burgdorferi must migrate within and between its arthropod and mammalian hosts in order to complete its natural enzootic cycle. During tick feeding, the spirochete transmits from the tick to the host dermis, eventually colonizing and persisting within multiple, distant tissues. This dissemination modality suggests that flagellar motor rotation and, by extension, motility are crucial for infection. We recently reported that a nonmotile flaB mutant that lacks periplasmic flagella is rod shaped and unable to infect mice by needle or tick bite. However, those studies could not differentiate whether motor rotation or merely the possession of the periplasmic flagella was crucial for cellular morphology and host persistence. Here, we constructed and characterized a motB mutant that is nonmotile but retains its periplasmic flagella. Even though ΔmotB bacteria assembled flagella, part of the mutant cell is rod shaped. Cryoelectron tomography revealed that the flagellar ribbons are distorted in the mutant cells, indicating that motor rotation is essential for spirochetal flat-wave morphology. The ΔmotB cells are unable to infect mice, survive in the vector, or migrate out of the tick. Coinfection studies determined that the presence of these nonmotile ΔmotB cells has no effect on the clearance of wild-type spirochetes during murine infection and vice versa. Together, our data demonstrate that while flagellar motor rotation is necessary for spirochetal morphology and motility, the periplasmic flagella display no additional properties related to immune clearance and persistence within relevant hosts. PMID:25690096

  7. Zonal changes in the three-dimensional morphology of the chondron under compression: The relationship among cellular, pericellular, and extracellular deformation in articular cartilage

    PubMed Central

    Choi, Jae Bong; Youn, Inchan; Cao, Li; Leddy, Holly A.; Gilchrist, Christopher L.; Setton, Lori A.; Guilak, Farshid

    2008-01-01

    The pericellular matrix (PCM) is a narrow region of tissue that completely surrounds chondrocytes in articular cartilage. Previous theoretical models of the “chondron” (the PCM with enclosed cells) suggest that the structure and properties of the PCM may significantly influence the mechanical environment of the chondrocyte. The objective of this study was to quantify changes in the 3D morphology of the chondron in situ at different magnitudes of compression applied to the cartilage extracellular matrix. Fluorescence immunolabeling for type VI collagen was used to identify the boundaries of the cell and PCM, and confocal microscopy was used to form 3D images of chondrons from superficial, middle, and deep zone cartilage in explants compressed to 0%, 10%, 30%, and 50% surface-to-surface strain. Lagrangian tissue strain, determined locally using texture correlation, was highly inhomogeneous and revealed depth-dependent properties of the extracellular matrix. Compression significantly decreased cell and chondron height and volume, depending on the zone and magnitude of compression. In the superficial zone, cellular-level strains were always lower than tissue-level strains. In the middle and deep zones, however, tissue strains below 25% were amplified at the cellular level, while tissue strains above 25% were decreased at the cellular level. These findings are consistent with previous theoretical models of the chondron, suggesting that the PCM can serve as either a protective layer for the chondrocyte or a transducer that amplifies strain, such that cellular-level strains are more homogenous throughout the tissue depth despite large inhomogeneities in local ECM strains. PMID:17397851

  8. Temporal regulation of global gene expression and cellular morphology in Xenopus kidney cells in response to clinorotation

    NASA Astrophysics Data System (ADS)

    Kitamoto, Junko; Fukui, Akimasa; Asashima, Makoto

    Here, we report changes gene expression and morphology of the renal epithelial cell line, A6, which was derived from Xenopus laevis adult kidney that had been induced by long-term culturing with a three-dimensional clinostat. An oligo microarray analysis on the A6 cells showed that mRNA levels for 52 out of 8091 genes were significantly altered in response to clinorotation. On day 5, there was no dramatic change in expression level, but by day 8 and day 10, either upregulation or downregulation of gene expression became evident. By day 15, the expression levels of 18 out of 52 genes had returned to the original levels, while the remaining 34 genes maintained the altered levels of expression. Quantitative analyses of gene expression by real-time PCR confirmed that changes in the mRNA levels of selected genes were found only under clinorotation and not under hypergravity (7 g) or ground control. Morphological changes including loss of dome-like structures and disorganization of both E-cadherin adherence junctions and cortical actin were also observed after 10 days of culturing with clinorotation. These results revealed that the expression of selected genes was altered specifically in A6 cells cultured under clinorotation.

  9. Cellular Growth and Mitochondrial Ultrastructure of Leishmania (Viannia) braziliensis Promastigotes Are Affected by the Iron Chelator 2,2-Dipyridyl

    PubMed Central

    Mesquita-Rodrigues, Camila; Menna-Barreto, Rubem F. S.; Sabóia-Vahia, Leonardo; Da-Silva, Silvia A. G.; de Souza, Elen M.; Waghabi, Mariana C.; Cuervo, Patrícia; De Jesus, José B.

    2013-01-01

    Background Iron is an essential element for the survival of microorganisms in vitro and in vivo, acting as a cofactor of several enzymes and playing a critical role in host-parasite relationships. Leishmania (Viannia) braziliensis is a parasite that is widespread in the new world and considered the major etiological agent of American tegumentary leishmaniasis. Although iron depletion leads to promastigote and amastigote growth inhibition, little is known about the role of iron in the biology of Leishmania. Furthermore, there are no reports regarding the importance of iron for L. (V.) braziliensis. Methodology/Principal Findings In this study, the effect of iron on the growth, ultrastructure and protein expression of L. (V.) braziliensis was analyzed by the use of the chelator 2,2-dipyridyl. Treatment with 2,2-dipyridyl affected parasites' growth in a dose- and time-dependent manner. Multiplication of the parasites was recovered after reinoculation in fresh culture medium. Ultrastructural analysis of treated promastigotes revealed marked mitochondrial swelling with loss of cristae and matrix and the presence of concentric membranar structures inside the organelle. Iron depletion also induced Golgi disruption and intense cytoplasmic vacuolization. Fluorescence-activated cell sorting analysis of tetramethylrhodamine ester-stained parasites showed that 2,2-dipyridyl collapsed the mitochondrial membrane potential. The incubation of parasites with propidium iodide demonstrated that disruption of mitochondrial membrane potential was not associated with plasma membrane permeabilization. TUNEL assays indicated no DNA fragmentation in chelator-treated promastigotes. In addition, two-dimensional electrophoresis showed that treatment with the iron chelator induced up- or down-regulation of proteins involved in metabolism of nucleic acids and coordination of post-translational modifications, without altering their mRNA levels. Conclusions Iron chelation leads to a

  10. Morphology of leukocytes from cats affected with alpha-mannosidosis and mucopolysaccharidosis VI (MPS VI).

    PubMed

    Alroy, J; Freden, G O; Goyal, V; Raghavan, S S; Schunk, K L

    1989-07-01

    The morphology and ultrastructure of circulating white blood cells from six Persian and from five Russian Blue/Siamese cats deficient in lysosomal activity of alpha-mannosidase and arylsulfatase B, respectively, were studied and compared to cells from corresponding normal and carrier cats. In cats with mannosidosis, light microscopic examination revealed vacuoles in lymphocytes and monocytes, whereas electron microscopic studies demonstrated additional vacuoles in neutrophils, eosinophils, and basophils. In cats with mucopolysaccharidosis VI (MPS VI), vacuoles containing metachromatic granules were observed in lymphocytes, neutrophils, eosinophils, and monocytes. Ultrastructural studies of these cells identified the accumulation of fibrillar material, which often was associated with lamellated membrane structures. PMID:2503918

  11. Oxidation rate of iron sulfides as affected by surface area, morphology, oxygen concentration and autotrophic bacteria

    SciTech Connect

    Pugh, C.E.

    1984-05-01

    The relationship between surface area and rate of oxidation of Fe sulphides (pyrite and marcasite) separated from Texas lignite was studied. The reaction kinetics with respect to Fe sulphide morphology and particle size were evaluated. The oxygen concentration and the presence of autotrophic Fe and S-oxidizing bacteria (thiobacillus ferro-oxidans) on the rate of oxidation were also evaluated. The formation of sulphate from Fe sulphide was selected to measure the rate of oxidation. Relative reaction rates for different morphological forms of Fe sulphide were: marcasite > framboidal pyrite > massive pyrite. As the surface area of pyrite doubled, reaction rate increased by a factor of 1.5. Sulphate production for the 5 to 2 ..mu..m fraction was twice that of the 50 to 20 ..mu..m fraction. Reaction rate was approximately fivefold greater for non-inoculated treatments at 20% O/sub 2/ compared with 0% O/sub 2/ and was approximately ninefold greater for the same treatment inoculated with T. ferro-oxidans.

  12. Two- and three- dimensional studies of dendritic morphology in magnesium alloy by means of synchrotron X-ray microtomography and cellular automaton modelling

    NASA Astrophysics Data System (ADS)

    Yang, M.; Guo, Z.; Xiong, S.

    2015-06-01

    Magnesium is the lightest structural material. As one of the dominant microstructure features, dendritic pattern determines the mechanical behaviour and performance of magnesium alloys. Dendritic topological observation was carried out on Mg-based alloy using synchrotron X-ray micro-tomography and the microstructure pattern of α-Mg dendrite was obtained. It was found that the α-Mg dendrite grew with eighteen primary stems, of which six lay in the (0001) basal plane, and the other twelve in the (1010) plane. An according numerical model based on the cellular automata method was developed. By defining a specific capturing functional mechanism, simulation of α-Mg dendrite in 3-D with eighteen branches was successfully achieved. The simulation results show that the model could reasonably describe the evolution of the dendritic microstructure and the subsequent dendrite morphology agrees well with that observed in the synchrotron X-ray tomography experiment.

  13. Eutrophication of Typical Chinese Shallow Lakes as affected by Hydrologic Characteristics and Lake-Basin Morphology

    NASA Astrophysics Data System (ADS)

    Huang, J.; Xu, Q.; Xi, B.; Wang, X.; Li, W.; Ji, D.; Jiang, T.

    2013-12-01

    The region below midstream of the Yangtze River is one of the areas in China that have a highest density of lakes, in particular shallow lakes. It has five nationally well-known freshwater lakes with largest sizes, namely the Poyang Lake, Doingting Lake, Taihu Lake, Chaohu Lake, and Hongze Lake. This region has 138 lakes with a water surface area of 10 km2 or larger. However, approximately 70% of the large- to medium-sized lakes in the eastern plains of China have been altered from pristine into reservoir-like conditions. Previous studies indicate that hydrologic characteristics and lake-basin morphology likely have important effects on the water quality (or eutrophication) of shallow lakes. However, little is known about quantitative relations among lake water quality, lake-basin morphology, and hydrologic characteristics. The objective of this study was to determine such quantitative relations using data on water quality, water ecology, hydrology, and basin morphology. The data were collected from 2008 to 2011 for ninety shallow lakes in the eastern plains of China. The results indicate that total nitrogen (TN), total phosphorus (TP), chlorophyll-a (Chl-a) concentrations decreased with increase of water depth. TN and TP concentrations in the lakes with a water depth of greater than 2m were less than those in the lakes with a water depth less than 2m. In addition, Chl-a concentration in the lakes with a surface area less than 25 km2 increased with the increase of relative water depth (Zr), whereas Chl-a concentration in the lakes with a surface area greater than 25 km2 decreased with the increase of Zr. Further, as influenced by hydrologic characteristics, the lakes in the upper reaches of the Yangtze River tended to have a better water quality than the lakes in the lower reaches, while the lakes that are hydraulically connected with the Yangtze River tended to have a better water quality than the lakes that are hydraulically disconnected from the river.

  14. Individual experience and evolutionary history of predation affect expression of heritable variation in fish personality and morphology

    PubMed Central

    Dingemanse, Niels J.; Van der Plas, Fons; Wright, Jonathan; Réale, Denis; Schrama, Maarten; Roff, Derek A.; Van der Zee, Els; Barber, Iain

    2009-01-01

    Predation plays a central role in evolutionary processes, but little is known about how predators affect the expression of heritable variation, restricting our ability to predict evolutionary effects of predation. We reared families of three-spined stickleback Gasterosteus aculeatus from two populations—one with a history of fish predation (predator sympatric) and one without (predator naive)—and experimentally manipulated experience of predators during ontogeny. For a suite of ecologically relevant behavioural (‘personality’) and morphological traits, we then estimated two key variance components, additive genetic variance (VA) and residual variance (VR), that jointly shape narrow-sense heritability (h2= VA/(VA + VR)). Both population and treatment differentially affected VA versus VR, hence h2, but only for certain traits. The predator-naive population generally had lower VA and h2 values than the predator-sympatric population for personality behaviours, but not morphological traits. Values of VR and h2 were increased for some, but decreased for other personality traits in the predator-exposed treatment. For some personality traits, VA and h2 values were affected by treatment in the predator-naive population, but not in the predator-sympatric population, implying that the latter harboured less genetic variation for behavioural plasticity. Replication and experimental manipulation of predation regime are now needed to confirm that these population differences were related to variation in predator-induced selection. Cross-environment genetic correlations (rA) were tight for most traits, suggesting that predator-induced selection can affect the evolution of the same trait expressed in the absence of predators. The treatment effects on variance components imply that predators can affect evolution, not only by acting directly as selective agents, but also by influencing the expression of heritable variation. PMID:19129142

  15. Diagnostic cellular abnormalities in neoplastic and non-neoplastic lesions of the epidermis: a morphological and statistical study

    PubMed Central

    Malhotra, Saurabh; Kazlouskaya, Viktoryia; Andres, Christian; Gui, Jiang; Elston, Dirk

    2013-01-01

    Background Distinguishing cellular abnormalities in reactive and malignant lesions is challenging. We compared the incidence and severity of cytological abnormalities in malignant/premalignant and benign epidermal lesions. Methods One hundred fifty-two biopsies representing 69 malignant/premalignant squamous lesions and 83 benign conditions were studied. Cytological features, including nuclear hyperchromasia, nuclear overlap (crowding), irregular nuclei, high nuclear/cytoplasmic (N/C) ratio, conspicuous nucleoli, delicate inconspicuous nucleoli, clumped chromatin, pleomorphic parakeratosis, normal and abnormal mitotic figures and necrotic keratinocytes, were evaluated and graded. Statistical analysis was performed. Results Irregular nuclei, increased N/C ratio, conspicuous single prominent nucleoli, nuclear overlap (crowding), pleomorphic parakeratosis, nuclear hyperchromasia, necrotic keratinocytes, normal and abnormal mitotic figures and coarse chromatin were seen more frequently in malignant neoplasms (p < 0.05). Abnormal mitotic figures, although uncommon (20.3%), were only noted in the malignant/premalignant group. Certain cytological features were common among both malignant and benign lesions, suggesting that they are of little value. Conclusion In the setting of an atypical cutaneous squamous proliferation, nuclear irregularity, increased N/C ratio, conspicuous nucleoli, crowding and hyperchromasia are the most useful indicators of malignancy. In contrast, mitotic figures, necrotic cells and coarse chromatin are less useful. The presence of abnormal mitotic figures is very helpful when present; however, their overall rarity limits their utility. PMID:23398548

  16. Real-Time Observation on Evolution of Droplets Morphology Affected by Electric Current Pulse in Al-Bi Immiscible Alloy

    NASA Astrophysics Data System (ADS)

    Zhu, Jing; Wang, Tongmin; Cao, Fei; Fu, Hongwang; Fu, Yanan; Xie, Honglan; Xiao, Tiqiao

    2013-05-01

    The evolution of Bi-rich droplets morphology in a solidifying Al-Bi immiscible alloy was directly observed using a synchrotron microradiography technique. The electric current pulse (ECP) was applied to control the solidification process of Al-Bi immiscible alloy. It was found that the electromagnetic pinch force and Marangoni force induced by ECP and temperature gradient, respectively, can significantly affect the distribution of Bi-rich droplets. The electromagnetic pinch force drove the droplets from the center to side; meanwhile, the Marangoni force lifted the droplets from the bottom to the top. As a result, the droplets finally distributed with a manner of "inverted triangle."

  17. Developmental Trenbolone Exposure Affects Adult Breeding Behavior, Fecundity and Morphology of Xenopus tropicalis

    EPA Science Inventory

    Trenbolone acetate is a synthetic androgen used as a growth promoter in the cattle industry. Its metabolite 17â-trenbolone (17â-T) has been detected downstream from cattle feedlots. It could be a concern to wildlife near these areas as previous studies show 17â-T exposure affects...

  18. The linker histone in Saccharomyces cerevisiae interacts with actin-related protein 4 and both regulate chromatin structure and cellular morphology.

    PubMed

    Georgieva, Milena; Staneva, Dessislava; Uzunova, Katya; Efremov, Toni; Balashev, Konstantin; Harata, Masahiko; Miloshev, George

    2015-02-01

    Chromatin structure promotes important epigenetic mechanisms that regulate cellular fate by organizing, preserving and controlling the way by which the genetic information works. Our understanding of chromatin and its functions is sparse and not yet well defined. The uncertainty comes from the complexity of chromatin and is induced by the existence of a large number of nuclear proteins that influence it. The intricate interaction among all these structural and functional nuclear proteins has been under extensive study in the recent years. Here, we show that Saccharomyces cerevisiae linker histone physically interacts with Arp4p (actin-related protein 4) which is a key subunit of three chromatin modifying complexes - INO80, SWR1 and NuA4. A single - point mutation in the actin - fold domain of Arp4p together with the knock-out of the gene for the linker histone in S. cerevisiae severely abrogates cellular and nuclear morphology and leads to complete disorganizing of the higher levels of chromatin organization. PMID:25542182

  19. Homology and Potential Cellular and Molecular Mechanisms for the Development of Unique Feather Morphologies in Early Birds.

    PubMed

    O'Connor, Jingmai K; Chiappe, Luis M; Chuong, Cheng-Ming; Bottjer, David J; You, Hailu

    2012-09-14

    At least two lineages of Mesozoic birds are known to have possessed a distinct feather morphotype for which there is no neornithine (modern) equivalent. The early stepwise evolution of apparently modern feathers occurred within Maniraptora, basal to the avian transition, with asymmetrical pennaceous feathers suited for flight present in the most basal recognized avian, Archaeopteryx lithographica. The number of extinct primitive feather morphotypes recognized among non-avian dinosaurs continues to increase with new discoveries; some of these resemble feathers present in basal birds. As a result, feathers between phylogenetically widely separated taxa have been described as homologous. Here we examine the extinct feather morphotypes recognized within Aves and compare these structures with those found in non-avian dinosaurs. We conclude that the "rachis dominated" tail feathers of Confuciusornis sanctus and some enantiornithines are not equivalent to the "proximally ribbon-like" pennaceous feathers of the juvenile oviraptorosaur Similicaudipteryx yixianensis. Close morphological analysis of these unusual rectrices in basal birds supports the interpretation that they are modified pennaceous feathers. Because this feather morphotype is not seen in living birds, we build on current understanding of modern feather molecular morphogenesis to suggest a hypothetical molecular developmental model for the formation of the rachis dominated feathers of extinct basal birds. PMID:24003379

  20. The Absence of Pupylation (Prokaryotic Ubiquitin-Like Protein Modification) Affects Morphological and Physiological Differentiation in Streptomyces coelicolor

    PubMed Central

    Seghezzi, Nicolas; Duchateau, Magalie; Gominet, Myriam; Kofroňová, Olga; Benada, Oldřich; Mazodier, Philippe

    2015-01-01

    ABSTRACT Protein turnover is essential in all living organisms for the maintenance of normal cell physiology. In eukaryotes, most cellular protein turnover involves the ubiquitin-proteasome pathway, in which proteins tagged with ubiquitin are targeted to the proteasome for degradation. In contrast, most bacteria lack a proteasome but harbor proteases for protein turnover. However, some actinobacteria, such as mycobacteria, possess a proteasome in addition to these proteases. A prokaryotic ubiquitination-like tagging process in mycobacteria was described and was named pupylation: proteins are tagged with Pup (prokaryotic ubiquitin-like protein) and directed to the proteasome for degradation. We report pupylation in another actinobacterium, Streptomyces coelicolor. Both the morphology and life cycle of Streptomyces species are complex (formation of a substrate and aerial mycelium followed by sporulation), and these bacteria are prolific producers of secondary metabolites with important medicinal and agricultural applications. The genes encoding the pupylation system in S. coelicolor are expressed at various stages of development. We demonstrated that pupylation targets numerous proteins and identified 20 of them. Furthermore, we established that abolition of pupylation has substantial effects on morphological and metabolic differentiation and on resistance to oxidative stress. In contrast, in most cases, a proteasome-deficient mutant showed only modest perturbations under the same conditions. Thus, the phenotype of the pup mutant does not appear to be due solely to defective proteasomal degradation. Presumably, pupylation has roles in addition to directing proteins to the proteasome. IMPORTANCE Streptomyces spp. are filamentous and sporulating actinobacteria, remarkable for their morphological and metabolic differentiation. They produce numerous bioactive compounds, including antifungal, antibiotic, and antitumor compounds. There is therefore considerable interest in

  1. Morphology of weld heat-affected zone liquation cracking in Ta-modified cast alloy 718

    SciTech Connect

    West, S.L.; Baeslack, W.A. . Dept. of Welding Engineering); Kelly, T.J. . Aircraft Engine Business Group)

    1989-11-01

    The authors' discuss some problems involved in the use of alloy 718 which is a precipitation-hardenable, nickel-base superalloy developed in the early 1960s for medium temperature (540-705{sup 0}C) aerospace applications. The use of Nb as a substitute for Al and Ti leads to a susceptibility to liquation cracking in the weld heat-affected zone (HAZ). This problem is discussed in detail in the article.

  2. Factors Affecting the Morphology of Pb-Based Glass Frit Coated with Ag Material Prepared by Electroless Silver Plating

    NASA Astrophysics Data System (ADS)

    Huang, Bei; Gan, Weiping; Zhou, Jian; Li, Yingfen; Lin, Tao; Liu, Xiaogang

    2014-05-01

    Pb-based glass frit coated with nanosilver material for Si solar cell applications has been directly prepared by electroless silver plating. Activation of the glass frit was accomplished by using glycol, with the aim of reducing the silver ions to elemental silver on the surface of the glass frit. Electroless silver plating onto the glass frit was successfully realized using two kinds of electroless plating bath. However, the morphology of the composite powder greatly affected the modality, sheet resistance, series resistance, and photoelectric conversion efficiency of the conducting silver films. We found that the activation temperature affected the number and distribution of silver nanoparticles. Meanwhile, the average grain size of the silver particles and the silver content in the Pb-based glass frit coated with Ag material could be controlled by adjusting the pH value and loading capacity, respectively, during plating.

  3. The multiple roles of cyclin E1 in controlling cell cycle progression and cellular morphology of Trypanosoma brucei.

    PubMed

    Gourguechon, Stéphane; Savich, Jason M; Wang, Ching C

    2007-05-11

    Regulation of eukaryotic cell cycle progression requires sequential activation and inactivation of cyclin-dependent kinases. Previous RNA interference (RNAi) experiments in Trypanosoma brucei indicated that cyclin E1, cdc2-related kinase (CRK)1 and CRK2 are involved in regulating G1/S transition, whereas cyclin B2 and CRK3 play a pivotal role in controlling the G2/M checkpoint. To search for potential interactions between the other cyclins and CRKs that may not have been revealed by the RNAi assays, we used the yeast two-hybrid system and an in vitro glutathione-S-transferase pulldown assay and observed interactions between cyclin E1 and CRK1, CRK2 and CRK3. Cyclins E1-E4 are homologues of yeast Pho80 cyclin. But yeast complementation assays indicated that none of them possesses a Pho80-like function. Analysis of cyclin E1+CRK1 and cyclin E1+CRK2 double knockdowns in the procyclic form of T. brucei indicated that the cells were arrested more extensively in the G1 phase beyond the cumulative effect of individual knockdowns. But BrdU incorporation was impaired significantly only in cyclin E1+CRK1-depleted cells, whereas a higher percentage of cyclin E1+CRK2 knockdown cells assumed a grossly elongated posterior end morphology. A double knockdown of cyclin E1 and CRK3 arrested cells in G2/M much more efficiently than if only CRK3 was depleted. Taken together, these data suggest multiple functions of cyclin E1: it forms a complex with CRK1 in promoting G1/S phase transition; it forms a complex with CRK2 in controlling the posterior morphogenesis during G1/S transition; and it forms a complex with CRK3 in promoting passage across the G2/M checkpoint in the trypanosome. PMID:17376478

  4. THE MULTIPLE ROLES OF CYCLIN E1 IN CONTROLLING CELL CYCLE PROGRESSION AND CELLULAR MORPHOLOGY OF TRYPANOSOMA BRUCEI

    PubMed Central

    Gourguechon, Stéphane; Savich, Jason M.; Wang, Ching C.

    2009-01-01

    SUMMARY Regulation of eukaryotic cell cycle progression requires sequential activation and inactivation of cyclin-dependent kinases. Previous RNA interference (RNAi) experiments in Trypanosoma brucei indicated that cyclin E1, cdc2-related kinase (CRK)1 and CRK2 are involved in regulating G1/S transition, whereas cyclin B2 and CRK3 play a pivotal role in controlling the G2/M checkpoint. To search for potential interactions between the other cyclins and CRKs that may not have been revealed by the RNAi assays, we used the yeast two-hybrid system and an in vitro GST pulldown assay and observed interactions between cyclin E1 and CRK1, CRK2 and CRK3. Cyclins E1-E4 are homologues of yeast Pho80 cyclin. But yeast complementation assays indicated that none of them possesses a Pho80-like function. Analysis of cyclin E1+CRK1 and cyclin E1+CRK2 double knockdowns in the procyclic form of T. brucei indicated that the cells were arrested more extensively in the G1 phase beyond the cumulative effect of individual knockdowns. But BrdU incorporation was significantly impaired only in cyclin E1+CRK1 depleted cells, whereas a higher percentage of cyclin E1+CRK2 knockdown cells assumed a grossly elongated posterior end morphology. A double knockdown of cyclin E1 and CRK3 arrested cells in G2/M much more efficiently than if CRK3 was depleted alone. Taken together, these data suggest multiple functions of cyclin E1. It forms a complex with CRK1 in promoting G1/S phase transition, with CRK2 in controlling the posterior morphogenesis during G1/S transition and with CRK3 in promoting passage across the G2/M checkpoint in the trypanosome. PMID:17376478

  5. Deiodinase knockdown affects zebrafish eye development at the level of gene expression, morphology and function.

    PubMed

    Houbrechts, Anne M; Vergauwen, Lucia; Bagci, Enise; Van Houcke, Jolien; Heijlen, Marjolein; Kulemeka, Bernard; Hyde, David R; Knapen, Dries; Darras, Veerle M

    2016-03-15

    Retinal development in vertebrates relies extensively on thyroid hormones. Their local availability is tightly controlled by several regulators, including deiodinases (Ds). Here we used morpholino technology to explore the roles of Ds during eye development in zebrafish. Transcriptome analysis at 3 days post fertilization (dpf) revealed a pronounced effect of knockdown of both T4-activating Ds (D1D2MO) or knockdown of T3-inactivating D3 (D3bMO) on phototransduction and retinoid recycling. This was accompanied by morphological defects (studied from 1 to 7 dpf) including reduced eye size, disturbed retinal lamination and strong reduction in rods and all four cone types. Defects were more prominent and persistent in D3-deficient fish. Finally, D3-deficient zebrafish larvae had disrupted visual function at 4 dpf and were less sensitive to a light stimulus at 5 dpf. These data demonstrate the importance of TH-activating and -inactivating Ds for correct zebrafish eye development, and point to D3b as a central player. PMID:26802877

  6. Rearing conditions differently affect the motor performance and cerebellar morphology of prenatally stressed juvenile rats.

    PubMed

    Ulupinar, Emel; Erol, Kevser; Ay, Hakan; Yucel, Ferruh

    2015-02-01

    The cerebellum is one of the most vulnerable parts of the brain to environmental changes. In this study, the effect of diverse environmental rearing conditions on the motor performances of prenatally stressed juvenile rats and its reflection to the cerebellar morphology were investigated. Prenatally stressed Wistar rats were grouped according to different rearing conditions (Enriched=EC, Standard=SC and Isolated=IC) after weaning. Six weeks later, male and female offspring from different litters were tested behaviorally. In rotarod and string suspension tests, females gained better scores than males. Significant gender and housing effects were observed especially on the motor functions requiring fine skills with the best performance by enriched females, but the worst by enriched males. The susceptibility of cerebellar macro- and micro-neurons to environmental conditions was compared using stereological methods. In female groups, no differences were observed in the volume proportions of cerebellar layers, soma sizes and the numerical densities of granule or Purkinje cells. However, a significant interaction between housing and gender was observed in the granule to Purkinje cell ratio of males, due to the increased numerical densities of the granule cells in enriched males. These data imply that proper functioning of the cerebellum relies on its well organized and evolutionarily conserved structure and circuitry. Although early life stress leads to long term behavioral and neurobiological consequences in the offspring, diverse rearing conditions can alter the motor skills of animals and synaptic connectivity between Purkinje and granular cells in a gender dependent manner. PMID:25315128

  7. Methyl jasmonate affects morphology, number and activity of endoplasmic reticulum bodies in Raphanus sativus root cells.

    PubMed

    Gotté, Maxime; Ghosh, Rajgourab; Bernard, Sophie; Nguema-Ona, Eric; Vicré-Gibouin, Maïté; Hara-Nishimura, Ikuko; Driouich, Azeddine

    2015-01-01

    The endoplasmic reticulum (ER) bodies are ER-derived structures that are found in Brassicaceae species and thought to play a role in defense. Here, we have investigated the occurrence, distribution and function of ER bodies in root cells of Raphanus sativus using a combination of microscopic and biochemical methods. We have also assessed the response of ER bodies to methyl jasmonate (MeJA), a phytohormone that mediates plant defense against wounding and pathogens. Our results show that (i) ER bodies do occur in different root cell types from the root cap region to the differentiation zone; (ii) they do accumulate a PYK10-like protein similar to the major marker protein of ER bodies that is involved in defense in Arabidopsis thaliana; and (iii) treatment of root cells with MeJA causes a significant increase in the number of ER bodies and the activity of β-glucosidases. More importantly, MeJA was found to induce the formation of very long ER bodies that results from the fusion of small ones, a phenomenon that has not been reported in any other study so far. These findings demonstrate that MeJA impacts the number and morphology of functional ER bodies and stimulates ER body enzyme activities, probably to participate in defense responses of radish root. They also suggest that these structures may provide a defensive system specific to root cells. PMID:25305245

  8. Element distribution and morphology of spotted golden goatfish fish scales as affected by demineralisation.

    PubMed

    Chuaychan, Sira; Benjakul, Soottawat; Nuthong, Pornpot

    2016-04-15

    Scales of spotted golden goatfish were subjected to non-collagenous protein removal followed by demineralisation with hydrochloric acid at different concentrations (0.25, 0.5, 0.75 and 1 M) for various times (30, 60 and 90 min). The morphology and element composition/distribution of scales from spotted golden goatfish as influenced by demineralisation conditions were determined. The appropriate demineralisation was pertained using 0.75 M hydrochloric acid for 30 min, in which the ash content was 0.62% (dry weight basis). The scales having non-collagenous protein removal with, and without, subsequent demineralisation were analysed for element content using X-ray fluorescence spectrometer. Images of different scales were determined using scanning electron microscopy (SEM) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). Based on the images, an external layer rich in inorganic elements was removed. Most of Ca and P were eliminated with the coincidental increases in organic substances (C, N and O) after demineralisation. Demineralisation therefore mainly removed the external layer of scales, which facilitated the further extraction of collagen or gelatin. PMID:26617021

  9. Morphological Characteristics of Maize Canopy Development as Affected by Increased Plant Density

    PubMed Central

    Song, Youhong; Rui, Yukui; Bedane, Guta; Li, Jincai

    2016-01-01

    Improving crop productivity through higher plant density requires a detailed understanding of organ development in response to increased interplant competition. The objective of this paper is thus to investigate the characteristics of organ development under increased interplant competition. A field experiment was conducted to investigate organ development across 4 maize plant densities i.e. 2, 6, 12 and 20 plants m–2 (referred to PD2, PD6, PD12 and PD20 respectively). In response to increased interplant competition, lengths of both laminae and sheaths increased in lower phytomers, but decreased in upper phytomers. Sheath extension appeared to be less sensitive to increased interplant competition than lamina extension. Extension of laminae and internodes responded to increased plant density as soon as onset of mild interplant competition, but did not respond any further to severe competition. Both lamina width and internode diameter were reduced due to a smaller growth rate in response to increased plant density. Overall, this study identified that organ expansion rate can be taken as the key morphological factor to determine the degree of interplant competition. PMID:27129101

  10. Mapping Quantitative Trait Loci Affecting Biochemical and Morphological Fruit Properties in Eggplant (Solanum melongena L.).

    PubMed

    Toppino, Laura; Barchi, Lorenzo; Lo Scalzo, Roberto; Palazzolo, Eristanna; Francese, Gianluca; Fibiani, Marta; D'Alessandro, Antonietta; Papa, Vincenza; Laudicina, Vito A; Sabatino, Leo; Pulcini, Laura; Sala, Tea; Acciarri, Nazzareno; Portis, Ezio; Lanteri, Sergio; Mennella, Giuseppe; Rotino, Giuseppe L

    2016-01-01

    Eggplant berries are a source of health-promoting metabolites including antioxidant and nutraceutical compounds, mainly anthocyanins and chlorogenic acid; however, they also contain some anti-nutritional compounds such as steroidal glycoalkaloids (SGA) and saponins, which are responsible for the bitter taste of the flesh and with potential toxic effects on humans. Up to now, Quantitative Trait Loci (QTL) for the metabolic content are far from being characterized in eggplant, thus hampering the application of breeding programs aimed at improving its fruit quality. Here we report on the identification of some QTL for the fruit metabolic content in an F2 intraspecific mapping population of 156 individuals, obtained by crossing the eggplant breeding lines "305E40" × "67/3." The same population was previously employed for the development of a RAD-tag based linkage map and the identification of QTL associated to morphological and physiological traits. The mapping population was biochemically characterized for both fruit basic qualitative data, like dry matter, °Brix, sugars, and organic acids, as well as for health-related compounds such chlorogenic acid, (the main flesh monomeric phenol), the two peel anthocyanins [i.e., delphinidin-3-rutinoside (D3R) and delphinidin-3-(p- coumaroylrutinoside)-5-glucoside (nasunin)] and the two main steroidal glycoalkaloids, solasonine, and solamargine. For most of the traits, one major QTL (PVE ≥10%) was spotted and putative orthologies with other Solanaceae crops are discussed. The present results supply valuable information to eggplant breeders on the inheritance of key fruit quality traits, thus providing potential tools to assist future breeding programs. PMID:26973692

  11. Bisphenol A affects placental layers morphology and angiogenesis during early pregnancy phase in mice.

    PubMed

    Tait, Sabrina; Tassinari, Roberta; Maranghi, Francesca; Mantovani, Alberto

    2015-11-01

    Bisphenol A (BPA) is a widespread endocrine disrupter mainly used in food contact plastics. Much evidence supports the adverse effects of BPA, particularly on susceptible groups such as pregnant women. The present study considered placental development - relevant for pregnancy outcomes and fetal nutrition/programming - as a potential target of BPA. Pregnant CD-1 mice were administered per os with vehicle, 0.5 (BPA05) or 50 mg kg(-1) (BPA50) body weight day(-1) of BPA, from gestational day (GD) 1 to GD11. At GD12, BPA50 induced significant degeneration and necrosis of giant cells, increased vacuolization in the junctional zone in the absence of glycogen accumulation and reduction of the spongiotrophoblast layer. In addition, BPA05 induced glycogen depletion as well as significant nuclear accumulation of β-catenin in trophoblasts of labyrinthine and spongiotrophoblast layers, supporting the activation of the Wnt/β-catenin pathway. Transcriptomic analysis indicated that BPA05 promoted and BPA50 inhibited blood vessel development and branching; morphologically, maternal vessels were narrower in BPA05 placentas, whereas embryonic and maternal vessels were irregularly dilated in the labyrinth of BPA50 placentas. Quantitative polymerase chain reaction evidenced an estrogen receptor β induction by BPA50, which did not correspond to downstream genes activation; indeed, the transcription factor binding sites analysis supported the AhR/Arnt complex as regulator of BPA50-modulated genes. Conversely, Creb appeared as the main transcription factor regulating BPA05-modulated genes. Embryonic structures (head, forelimb) showed divergent perturbations upon BPA05 or BPA50 exposure, potentially related to unbalanced embryonic nutrition and/or to modulation of genes involved in embryo development. Our findings support placenta as an important target of BPA, even at environmentally relevant dose levels. PMID:26063408

  12. Mapping Quantitative Trait Loci Affecting Biochemical and Morphological Fruit Properties in Eggplant (Solanum melongena L.)

    PubMed Central

    Toppino, Laura; Barchi, Lorenzo; Lo Scalzo, Roberto; Palazzolo, Eristanna; Francese, Gianluca; Fibiani, Marta; D'Alessandro, Antonietta; Papa, Vincenza; Laudicina, Vito A.; Sabatino, Leo; Pulcini, Laura; Sala, Tea; Acciarri, Nazzareno; Portis, Ezio; Lanteri, Sergio; Mennella, Giuseppe; Rotino, Giuseppe L.

    2016-01-01

    Eggplant berries are a source of health-promoting metabolites including antioxidant and nutraceutical compounds, mainly anthocyanins and chlorogenic acid; however, they also contain some anti-nutritional compounds such as steroidal glycoalkaloids (SGA) and saponins, which are responsible for the bitter taste of the flesh and with potential toxic effects on humans. Up to now, Quantitative Trait Loci (QTL) for the metabolic content are far from being characterized in eggplant, thus hampering the application of breeding programs aimed at improving its fruit quality. Here we report on the identification of some QTL for the fruit metabolic content in an F2 intraspecific mapping population of 156 individuals, obtained by crossing the eggplant breeding lines “305E40” × “67/3.” The same population was previously employed for the development of a RAD-tag based linkage map and the identification of QTL associated to morphological and physiological traits. The mapping population was biochemically characterized for both fruit basic qualitative data, like dry matter, °Brix, sugars, and organic acids, as well as for health-related compounds such chlorogenic acid, (the main flesh monomeric phenol), the two peel anthocyanins [i.e., delphinidin-3-rutinoside (D3R) and delphinidin-3-(p- coumaroylrutinoside)-5-glucoside (nasunin)] and the two main steroidal glycoalkaloids, solasonine, and solamargine. For most of the traits, one major QTL (PVE ≥10%) was spotted and putative orthologies with other Solanaceae crops are discussed. The present results supply valuable information to eggplant breeders on the inheritance of key fruit quality traits, thus providing potential tools to assist future breeding programs. PMID:26973692

  13. [MORPHOLOGICAL FEATURES OF RAT MUCOUS MEMBRANE OF THE TONGUE EARLY AFFECTED BY ACRYLIC RESIN MONOMER].

    PubMed

    Davydenko, V; Nidzelskiy, M; Starchenko, I; Davydenko, A; Kuznetsov, V

    2016-03-01

    Base materials, made on the basis of various derivatives of acrylic and methacrylic acids, have been widely used in prosthetic dentistry. Free monomer, affecting the tissues of prosthetic bed and the whole body, is always found in dentures. Therefore, study of the effect of acrylic resins' monomer on mucous membrane of the tongue is crucial. Rat tongue is very similar to human tongue, and this fact has become the basis for selecting these animals to be involved into the experiment. The paper presents the findings related to the effect of "Ftoraks" base acrylic resin monomer on the state of rat mucous membrane of the tongue and its regeneration. The microscopy has found that the greatest changes in the mucous membrane of the tongue occur on day 3 and 7 day after applying the monomer and are of erosive and inflammatory nature. Regeneration of tongue epithelium slows down. PMID:27119844

  14. spn-F encodes a novel protein that affects oocyte patterning and bristle morphology in Drosophila.

    PubMed

    Abdu, Uri; Bar, Dikla; Schüpbach, Trudi

    2006-04-01

    The anteroposterior and dorsoventral axes of the Drosophila embryo are established during oogenesis through the activities of Gurken (Grk), a Tgfalpha-like protein, and the Epidermal growth factor receptor (Egfr). spn-F mutant females produce ventralized eggs similar to the phenotype produced by mutations in the grk-Egfr pathway. We found that the ventralization of the eggshell in spn-F mutants is due to defects in the localization and translation of grk mRNA during mid-oogenesis. Analysis of the microtubule network revealed defects in the organization of the microtubules around the oocyte nucleus. In addition, spn-F mutants have defective bristles. We cloned spn-F and found that it encodes a novel coiled-coil protein that localizes to the minus end of microtubules in the oocyte, and this localization requires the microtubule network and a Dynein heavy chain gene. We also show that Spn-F interacts directly with the Dynein light chain Ddlc-1. Our results show that we have identified a novel protein that affects oocyte axis determination and the organization of microtubules during Drosophila oogenesis. PMID:16540510

  15. The UL24 protein of herpes simplex virus 1 affects the sub-cellular distribution of viral glycoproteins involved in fusion

    SciTech Connect

    Ben Abdeljelil, Nawel; Rochette, Pierre-Alexandre; Pearson, Angela

    2013-09-15

    Mutations in UL24 of herpes simplex virus type 1 can lead to a syncytial phenotype. We hypothesized that UL24 affects the sub-cellular distribution of viral glycoproteins involved in fusion. In non-immortalized human foreskin fibroblasts (HFFs) we detected viral glycoproteins B (gB), gD, gH and gL present in extended blotches throughout the cytoplasm with limited nuclear membrane staining; however, in HFFs infected with a UL24-deficient virus (UL24X), staining for the viral glycoproteins appeared as long, thin streaks running across the cell. Interestingly, there was a decrease in co-localized staining of gB and gD with F-actin at late times in UL24X-infected HFFs. Treatment with chemical agents that perturbed the actin cytoskeleton hindered the formation of UL24X-induced syncytia in these cells. These data support a model whereby the UL24 syncytial phenotype results from a mislocalization of viral glycoproteins late in infection. - Highlights: • UL24 affects the sub-cellular distribution of viral glycoproteins required for fusion. • Sub-cellular distribution of viral glycoproteins varies in cell-type dependent manner. • Drugs targeting actin microfilaments affect formation of UL24-related syncytia in HFFs.

  16. Lipid Biosynthetic Genes Affect Candida albicans Extracellular Vesicle Morphology, Cargo, and Immunostimulatory Properties

    PubMed Central

    Wolf, Julie M.; Espadas, Javier; Luque-Garcia, Jose; Reynolds, Todd

    2015-01-01

    Microbial secretion is integral for regulating cell homeostasis as well as releasing virulence factors during infection. The genes encoding phosphatidylserine synthase (CHO1) and phosphatidylserine decarboxylase (PSD1 and PSD2) are Candida albicans genes involved in phospholipid biosynthesis, and mutations in these genes affect mitochondrial function, cell wall thickness, and virulence in mice. We tested the roles of these genes in several agar-based secretion assays and observed that the cho1Δ/Δ and psd1Δ/Δ psd2Δ/Δ strains manifested less protease and phospholipase activity. Since extracellular vesicles (EVs) are surrounded by a lipid membrane, we investigated the effects of these mutations on EV structure, composition, and biological activity. The cho1Δ/Δ mutant releases EVs comparable in size to wild-type EVs, but EVs from the psd1Δ/Δ psd2Δ/Δ strain are much larger than those from the wild type, including a population of >100-nm EVs not observed in the EVs from the wild type. Proteomic analysis revealed that EVs from both mutants had a significantly different protein cargo than that of EVs from the wild type. EVs were tested for their ability to activate NF-κB in bone marrow-derived macrophage cells. While wild-type and psd1Δ/Δ psd2Δ/Δ mutant-derived EVs activated NF-κB, the cho1Δ/Δ mutant-derived EV did not. These studies indicate that the presence and absence of these C. albicans genes have qualitative and quantitative effects on EV size, composition, and immunostimulatory phenotypes that highlight a complex interplay between lipid metabolism and vesicle production. PMID:26024904

  17. Effects of antibacterial mineral leachates on the cellular ultrastructure, morphology, and membrane integrity of Escherichia coli and methicillin-resistant Staphylococcus aureus

    PubMed Central

    2010-01-01

    Background We have previously identified two mineral mixtures, CB07 and BY07, and their respective aqueous leachates that exhibit in vitro antibacterial activity against a broad spectrum of pathogens. The present study assesses cellular ultrastructure and membrane integrity of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli after exposure to CB07 and BY07 aqueous leachates. Methods We used scanning and transmission electron microscopy to evaluate E. coli and MRSA ultrastructure and morphology following exposure to antibacterial leachates. Additionally, we employed Baclight LIVE/DEAD staining and flow cytometry to investigate the cellular membrane as a possible target for antibacterial activity. Results Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging of E. coli and MRSA revealed intact cells following exposure to antibacterial mineral leachates. TEM images of MRSA showed disruption of the cytoplasmic contents, distorted cell shape, irregular membranes, and distorted septa of dividing cells. TEM images of E. coli exposed to leachates exhibited different patterns of cytoplasmic condensation with respect to the controls and no apparent change in cell envelope structure. Although bactericidal activity of the leachates occurs more rapidly in E. coli than in MRSA, LIVE/DEAD staining demonstrated that the membrane of E. coli remains intact, while the MRSA membrane is permeabilized following exposure to the leachates. Conclusions These data suggest that the leachate antibacterial mechanism of action differs for Gram-positive and Gram-negative organisms. Upon antibacterial mineral leachate exposure, structural integrity is retained, however, compromised membrane integrity accounts for bactericidal activity in Gram-positive, but not in Gram-negative cells. PMID:20846374

  18. Dietary inulin affects the morphology but not the sodium-dependent glucose and glutamine transport in the jejunum of broilers.

    PubMed

    Rehman, H; Rosenkranz, C; Böhm, J; Zentek, J

    2007-01-01

    Inulin, a prebiotic, is a fermentable oligosaccharide that may affect the intestinal mucosal architecture and the electrophysiological parameters. The effects of a diet with added inulin were tested on the jejunal morphology and electrogenic transport of Glc and Gln from the jejunal mucosa in broilers. Short-circuit current and transmucosal tissue resistance of jejunal flaps were measured in Ussing chambers. The feeding experiment was carried out in broilers (n = 40) using 1% inulin with an application period of 5 wk. The inulin-containing diet resulted in longer jejunal villi (P < 0.05) and deeper crypts (P < 0.01) than in control birds without affecting villus:crypt depth. Basal short-circuit current value remained unaffected by dietary treatment. Inulin supplementation did not modify the electrogenic transport of Glc and Gln in the jejunal mucosa. The basal value of transmucosal tissue resistance was significantly lower (P < 0.001) in the inulin-fed group compared with the control group. In conclusion, inulin supplementation affected the jejunal mucosal architecture but did not modify the electrogenic transport of Glc and amino acid under present experimental condition. PMID:17179425

  19. Calcium and ascorbic acid affect cellular structure and water mobility in apple tissue during osmotic dehydration in sucrose solutions.

    PubMed

    Mauro, Maria A; Dellarosa, Nicolò; Tylewicz, Urszula; Tappi, Silvia; Laghi, Luca; Rocculi, Pietro; Rosa, Marco Dalla

    2016-03-15

    The effects of the addition of calcium lactate and ascorbic acid to sucrose osmotic solutions on cell viability and microstructure of apple tissue were studied. In addition, water distribution and mobility modification of the different cellular compartments were observed. Fluorescence microscopy, light microscopy and time domain nuclear magnetic resonance (TD-NMR) were respectively used to evaluate cell viability and microstructural changes during osmotic dehydration. Tissues treated in a sucrose-calcium lactate-ascorbic acid solution did not show viability. Calcium lactate had some effects on cell walls and membranes. Sucrose solution visibly preserved the protoplast viability and slightly influenced the water distribution within the apple tissue, as highlighted by TD-NMR, which showed higher proton intensity in the vacuoles and lower intensity in cytoplasm-free spaces compared to other treatments. The presence of ascorbic acid enhanced calcium impregnation, which was associated with permeability changes of the cellular wall and membranes. PMID:26575708

  20. TDP-43 affects splicing profiles and isoform production of genes involved in the apoptotic and mitotic cellular pathways

    PubMed Central

    De Conti, Laura; Akinyi, Maureen V.; Mendoza-Maldonado, Ramiro; Romano, Maurizio; Baralle, Marco; Buratti, Emanuele

    2015-01-01

    In recent times, high-throughput screening analyses have broadly defined the RNA cellular targets of TDP-43, a nuclear factor involved in neurodegeneration. A common outcome of all these studies is that changing the expression levels of this protein can alter the expression of several hundred RNAs within cells. What still remains to be clarified is which changes represent direct cellular targets of TDP-43 or just secondary variations due to the general role played by this protein in RNA metabolism. Using an HTS-based splicing junction analysis we identified at least six bona fide splicing events that are consistent with being controlled by TDP-43. Validation of the data, both in neuronal and non-neuronal cell lines demonstrated that TDP-43 substantially alters the levels of isoform expression in four genes potentially important for neuropathology: MADD/IG20, STAG2, FNIP1 and BRD8. For MADD/IG20 and STAG2, these changes could also be confirmed at the protein level. These alterations were also observed in a cellular model that successfully mimics TDP-43 loss of function effects following its aggregation. Most importantly, our study demonstrates that cell cycle alterations induced by TDP-43 knockdown can be recovered by restoring the STAG2, an important component of the cohesin complex, normal splicing profile. PMID:26261209

  1. Plectin isoform P1b and P1d deficiencies differentially affect mitochondrial morphology and function in skeletal muscle

    PubMed Central

    Winter, Lilli; Kuznetsov, Andrey V.; Grimm, Michael; Zeöld, Anikó; Fischer, Irmgard; Wiche, Gerhard

    2015-01-01

    Plectin, a versatile 500-kDa cytolinker protein, is essential for muscle fiber integrity and function. The most common disease caused by mutations in the human plectin gene, epidermolysis bullosa simplex with muscular dystrophy (EBS-MD), is characterized by severe skin blistering and progressive muscular dystrophy. Besides displaying pathological desmin-positive protein aggregates and degenerative changes in the myofibrillar apparatus, skeletal muscle specimens of EBS-MD patients and plectin-deficient mice are characterized by massive mitochondrial alterations. In this study, we demonstrate that structural and functional alterations of mitochondria are a primary aftermath of plectin deficiency in muscle, contributing to myofiber degeneration. We found that in skeletal muscle of conditional plectin knockout mice (MCK-Cre/cKO), mitochondrial content was reduced, and mitochondria were aggregated in sarcoplasmic and subsarcolemmal regions and were no longer associated with Z-disks. Additionally, decreased mitochondrial citrate synthase activity, respiratory function and altered adenosine diphosphate kinetics were characteristic of plectin-deficient muscles. To analyze a mechanistic link between plectin deficiency and mitochondrial alterations, we comparatively assessed mitochondrial morphology and function in whole muscle and teased muscle fibers of wild-type, MCK-Cre/cKO and plectin isoform-specific knockout mice that were lacking just one isoform (either P1b or P1d) while expressing all others. Monitoring morphological alterations of mitochondria, an isoform P1b-specific phenotype affecting the mitochondrial fusion–fission machinery and manifesting with upregulated mitochondrial fusion-associated protein mitofusin-2 could be identified. Our results show that the depletion of distinct plectin isoforms affects mitochondrial network organization and function in different ways. PMID:26019234

  2. Plectin isoform P1b and P1d deficiencies differentially affect mitochondrial morphology and function in skeletal muscle.

    PubMed

    Winter, Lilli; Kuznetsov, Andrey V; Grimm, Michael; Zeöld, Anikó; Fischer, Irmgard; Wiche, Gerhard

    2015-08-15

    Plectin, a versatile 500-kDa cytolinker protein, is essential for muscle fiber integrity and function. The most common disease caused by mutations in the human plectin gene, epidermolysis bullosa simplex with muscular dystrophy (EBS-MD), is characterized by severe skin blistering and progressive muscular dystrophy. Besides displaying pathological desmin-positive protein aggregates and degenerative changes in the myofibrillar apparatus, skeletal muscle specimens of EBS-MD patients and plectin-deficient mice are characterized by massive mitochondrial alterations. In this study, we demonstrate that structural and functional alterations of mitochondria are a primary aftermath of plectin deficiency in muscle, contributing to myofiber degeneration. We found that in skeletal muscle of conditional plectin knockout mice (MCK-Cre/cKO), mitochondrial content was reduced, and mitochondria were aggregated in sarcoplasmic and subsarcolemmal regions and were no longer associated with Z-disks. Additionally, decreased mitochondrial citrate synthase activity, respiratory function and altered adenosine diphosphate kinetics were characteristic of plectin-deficient muscles. To analyze a mechanistic link between plectin deficiency and mitochondrial alterations, we comparatively assessed mitochondrial morphology and function in whole muscle and teased muscle fibers of wild-type, MCK-Cre/cKO and plectin isoform-specific knockout mice that were lacking just one isoform (either P1b or P1d) while expressing all others. Monitoring morphological alterations of mitochondria, an isoform P1b-specific phenotype affecting the mitochondrial fusion-fission machinery and manifesting with upregulated mitochondrial fusion-associated protein mitofusin-2 could be identified. Our results show that the depletion of distinct plectin isoforms affects mitochondrial network organization and function in different ways. PMID:26019234

  3. Deletion or Overexpression of Mitochondrial NAD+ Carriers in Saccharomyces cerevisiae Alters Cellular NAD and ATP Contents and Affects Mitochondrial Metabolism and the Rate of Glycolysis ▿

    PubMed Central

    Agrimi, Gennaro; Brambilla, Luca; Frascotti, Gianni; Pisano, Isabella; Porro, Danilo; Vai, Marina; Palmieri, Luigi

    2011-01-01

    The modification of enzyme cofactor concentrations can be used as a method for both studying and engineering metabolism. We varied Saccharomyces cerevisiae mitochondrial NAD levels by altering expression of its specific mitochondrial carriers. Changes in mitochondrial NAD levels affected the overall cellular concentration of this coenzyme and the cellular metabolism. In batch culture, a strain with a severe NAD depletion in mitochondria succeeded in growing, albeit at a low rate, on fully respiratory media. Although the strain increased the efficiency of its oxidative phosphorylation, the ATP concentration was low. Under the same growth conditions, a strain with a mitochondrial NAD concentration higher than that of the wild type similarly displayed a low cellular ATP level, but its growth rate was not affected. In chemostat cultures, when cellular metabolism was fully respiratory, both mutants showed low biomass yields, indicative of impaired energetic efficiency. The two mutants increased their glycolytic fluxes, and as a consequence, the Crabtree effect was triggered at lower dilution rates. Strikingly, the mutants switched from a fully respiratory metabolism to a respirofermentative one at the same specific glucose flux as that of the wild type. This result seems to indicate that the specific glucose uptake rate and/or glycolytic flux should be considered one of the most important independent variables for establishing the long-term Crabtree effect. In cells growing under oxidative conditions, bioenergetic efficiency was affected by both low and high mitochondrial NAD availability, which suggests the existence of a critical mitochondrial NAD concentration in order to achieve optimal mitochondrial functionality. PMID:21335394

  4. Use of a Generalized Additive Model to Investigate Key Abiotic Factors Affecting Microcystin Cellular Quotas in Heavy Bloom Areas of Lake Taihu

    PubMed Central

    Tao, Min; Xie, Ping; Chen, Jun; Qin, Boqiang; Zhang, Dawen; Niu, Yuan; Zhang, Meng; Wang, Qing; Wu, Laiyan

    2012-01-01

    Lake Taihu is the third largest freshwater lake in China and is suffering from serious cyanobacterial blooms with the associated drinking water contamination by microcystin (MC) for millions of citizens. So far, most studies on MCs have been limited to two small bays, while systematic research on the whole lake is lacking. To explain the variations in MC concentrations during cyanobacterial bloom, a large-scale survey at 30 sites across the lake was conducted monthly in 2008. The health risks of MC exposure were high, especially in the northern area. Both Microcystis abundance and MC cellular quotas presented positive correlations with MC concentration in the bloom seasons, suggesting that the toxic risks during Microcystis proliferations were affected by variations in both Microcystis density and MC production per Microcystis cell. Use of a powerful predictive modeling tool named generalized additive model (GAM) helped visualize significant effects of abiotic factors related to carbon fixation and proliferation of Microcystis (conductivity, dissolved inorganic carbon (DIC), water temperature and pH) on MC cellular quotas from recruitment period of Microcystis to the bloom seasons, suggesting the possible use of these factors, in addition to Microcystis abundance, as warning signs to predict toxic events in the future. The interesting relationship between macrophytes and MC cellular quotas of Microcystis (i.e., high MC cellular quotas in the presence of macrophytes) needs further investigation. PMID:22384128

  5. Use of a generalized additive model to investigate key abiotic factors affecting microcystin cellular quotas in heavy bloom areas of Lake Taihu.

    PubMed

    Tao, Min; Xie, Ping; Chen, Jun; Qin, Boqiang; Zhang, Dawen; Niu, Yuan; Zhang, Meng; Wang, Qing; Wu, Laiyan

    2012-01-01

    Lake Taihu is the third largest freshwater lake in China and is suffering from serious cyanobacterial blooms with the associated drinking water contamination by microcystin (MC) for millions of citizens. So far, most studies on MCs have been limited to two small bays, while systematic research on the whole lake is lacking. To explain the variations in MC concentrations during cyanobacterial bloom, a large-scale survey at 30 sites across the lake was conducted monthly in 2008. The health risks of MC exposure were high, especially in the northern area. Both Microcystis abundance and MC cellular quotas presented positive correlations with MC concentration in the bloom seasons, suggesting that the toxic risks during Microcystis proliferations were affected by variations in both Microcystis density and MC production per Microcystis cell. Use of a powerful predictive modeling tool named generalized additive model (GAM) helped visualize significant effects of abiotic factors related to carbon fixation and proliferation of Microcystis (conductivity, dissolved inorganic carbon (DIC), water temperature and pH) on MC cellular quotas from recruitment period of Microcystis to the bloom seasons, suggesting the possible use of these factors, in addition to Microcystis abundance, as warning signs to predict toxic events in the future. The interesting relationship between macrophytes and MC cellular quotas of Microcystis (i.e., high MC cellular quotas in the presence of macrophytes) needs further investigation. PMID:22384128

  6. Morphological changes to endothelial and interstitial cells and to the extra-cellular matrix in canine myxomatous mitral valve disease (endocardiosis).

    PubMed

    Han, R I; Clark, C H; Black, A; French, A; Culshaw, G J; Kempson, S A; Corcoran, B M

    2013-08-01

    Morphological and functional changes in endothelial and interstitial cells are considered central to myxomatous degeneration of the canine mitral valve (endocardiosis). The aim of this study was to describe and quantify changes in valve endothelial cells (VECs), interstitial cells (VICs) and the extra-cellular matrix (ECM) of the sub-endothelial zone of diseased valves using a combination of transmission electron microscopy, stereology and computer-aided image analysis. Marked degradation of the endothelium was evident in diseased valves, which coincided with significant degradation of the local ECM (P<0.001). There were decreases and increases in the numbers of VECs and VICs, respectively, in diseased valves, with particular accumulation of VICs subjacent to the valve surface (P<0.01). Overall, VICs were more pleomorphic than VECs in both normal and diseased valves, but for VECs, the degree of pleomorphism was significantly different in diseased valves (P<0.0001). The findings of the study confirm that canine myxomatous mitral valve disease is associated with marked endothelial damage, with attendant proliferation of subjacent activated myofibroblasts. The fact that similar endothelial changes are present in normal valves suggests these processes not only contribute to valve pathology, but may also represent life-long valve remodelling. PMID:23465752

  7. Chronic treatment with a precursor of cellular phosphatidylcholine ameliorates morphological and behavioral effects of aging in the mouse [correction of rat] hippocampus.

    PubMed

    Crespo, D; Megias, M; Fernandez-Viadero, C; Verduga, R

    2004-06-01

    Normal aging is commonly associated with a decline in memory, mainly for that related with newly acquired information. The hippocampal formation (HF) is a brain region that has been implicated in this dysfunction. Within the HF there are several cellular types, such as pyramidal cells, granule neurons of the dentate gyrus, and astrocytes. CDP-choline is a well-known intermediate in the biosynthesis of phosphatidylcholine, a phospholipid essential for neuronal membrane preservation and function; thus, this compound would attenuate the process of neuronal aging. To test this, three groups of male mice were used in this study. An adult 12-month-old group (ACG), a 24-month-old (OCG), and an old experimental group (OEG) were administered orally a solution of CDP-choline (150 mg/kg per day) from 12 up to 24 months. Experimental observations suggest that CDP-choline has a positive effect on memory (reference errors were attenuated), and hippocampal morphology resembled that of younger animals. PMID:15246991

  8. Salmonella adhesion, invasion and cellular immune responses are differentially affected by iron concentrations in a combined in vitro gut fermentation-cell model.

    PubMed

    Dostal, Alexandra; Gagnon, Mélanie; Chassard, Christophe; Zimmermann, Michael Bruce; O'Mahony, Liam; Lacroix, Christophe

    2014-01-01

    In regions with a high infectious disease burden, concerns have been raised about the safety of iron supplementation because higher iron concentrations in the gut lumen may increase risk of enteropathogen infection. The aim of this study was to investigate interactions of the enteropathogen Salmonella enterica ssp. enterica Typhimurium with intestinal cells under different iron concentrations encountered in the gut lumen during iron deficiency and supplementation using an in vitro colonic fermentation system inoculated with immobilized child gut microbiota combined with Caco-2/HT29-MTX co-culture monolayers. Colonic fermentation effluents obtained during normal, low (chelation by 2,2'-dipyridyl) and high iron (26.5 mg iron/L) fermentation conditions containing Salmonella or pure Salmonella cultures with similar iron conditions were applied to cellular monolayers. Salmonella adhesion and invasion capacity, cellular integrity and immune response were assessed. Under high iron conditions in pure culture, Salmonella adhesion was 8-fold increased compared to normal iron conditions while invasion was not affected leading to decreased invasion efficiency (-86%). Moreover, cellular cytokines IL-1β, IL-6, IL-8 and TNF-α secretion as well as NF-κB activation in THP-1 cells were attenuated under high iron conditions. Low iron conditions in pure culture increased Salmonella invasion correlating with an increase in IL-8 release. In fermentation effluents, Salmonella adhesion was 12-fold and invasion was 428-fold reduced compared to pure culture. Salmonella in high iron fermentation effluents had decreased invasion efficiency (-77.1%) and cellular TNF-α release compared to normal iron effluent. The presence of commensal microbiota and bacterial metabolites in fermentation effluents reduced adhesion and invasion of Salmonella compared to pure culture highlighting the importance of the gut microbiota as a barrier during pathogen invasion. High iron concentrations as

  9. Genotype-environment interactions affecting preflowering physiological and morphological traits of Brassica rapa grown in two watering regimes.

    PubMed

    El-Soda, Mohamed; Boer, Martin P; Bagheri, Hedayat; Hanhart, Corrie J; Koornneef, Maarten; Aarts, Mark G M

    2014-02-01

    Plant growth and productivity are greatly affected by drought, which is likely to become more threatening with the predicted global temperature increase. Understanding the genetic architecture of complex quantitative traits and their interaction with water availability may lead to improved crop adaptation to a wide range of environments. Here, the genetic basis of 20 physiological and morphological traits is explored by describing plant performance and growth in a Brassica rapa recombinant inbred line (RIL) population grown on a sandy substrate supplemented with nutrient solution, under control and drought conditions. Altogether, 54 quantitative trait loci (QTL) were identified, of which many colocated in 11 QTL clusters. Seventeen QTL showed significant QTL-environment interaction (Q×E), indicating genetic variation for phenotypic plasticity. Of the measured traits, only hypocotyl length did not show significant genotype-environment interaction (G×E) in both environments in all experiments. Correlation analysis showed that, in the control environment, stomatal conductance was positively correlated with total leaf dry weight (DW) and aboveground DW, whereas in the drought environment, stomatal conductance showed a significant negative correlation with total leaf DW and aboveground DW. This correlation was explained by antagonistic fitness effects in the drought environment, controlled by a QTL cluster on chromosome A7. These results demonstrate that Q×E is an important component of the genetic variance and can play a great role in improving drought tolerance in future breeding programmes. PMID:24474811

  10. Statin drugs mitigate cellular inflammatory response after ST elevation myocardial infarction, but do not affect in-hospital mortality

    PubMed Central

    Pourafkari, Leili; Visnjevac, Ognjen; Ghaffari, Samad; Nader, Nader D.

    2016-01-01

    Introduction: The objective was to examine the role of statins in modulating post-STEMI inflammation and related mortality. Methods: A total of 404 patients with STEMI were reviewed. Demographics, comorbidities, laboratory values, and outcomes were collected. The patients were grouped as STATIN and NOSTAT based on the use of statin drugs at the time of admission. Ninety-seven patients were receiving statin drugs. Results: The patients in the STATIN group were more likely to be hypertensive (53.6%), diabetic (37.1%) and to have previous coronary revascularization (9.3%). Following propensity matching of 89 patients in STATIN group to an equal number of patients in NOSTAT controls had lower neutrophil count 7.8 (6.8-8.4) compared to those in the NOSTAT group 9.1 (7.9-10.1). Although there was no difference in-hospital mortality between the two groups, the incidence of pump failure was lower in the STATIN group (5.6% vs. 15.7%; P < 0.01). Conclusion: Statin treatment prior to STEMI mitigates the cellular inflammatory response after the myocardial infarction, as evidenced by lower leukocyte and neutrophil cell counts in the STATIN group. PMID:27069565

  11. Collagen Substrate Stiffness Anisotropy Affects Cellular Elongation, Nuclear Shape, and Stem Cell Fate toward Anisotropic Tissue Lineage.

    PubMed

    Islam, Anowarul; Younesi, Mousa; Mbimba, Thomas; Akkus, Ozan

    2016-09-01

    Rigidity of substrates plays an important role in stem cell fate. Studies are commonly carried out on isotropically stiff substrate or substrates with unidirectional stiffness gradients. However, many native tissues are anisotropically stiff and it is unknown whether controlled presentation of stiff and compliant material axes on the same substrate governs cytoskeletal and nuclear morphology, as well as stem cell differentiation. In this study, electrocompacted collagen sheets are stretched to varying degrees to tune the stiffness anisotropy (SA) in the range of 1 to 8, resulting in stiff and compliant material axes orthogonal to each other. The cytoskeletal aspect ratio increased with increasing SA by about fourfold. Such elongation was absent on cellulose acetate replicas of aligned collagen surfaces indicating that the elongation was not driven by surface topography. Mesenchymal stem cells (MSCs) seeded on varying anisotropy sheets displayed a dose-dependent upregulation of tendon-related markers such as Mohawk and Scleraxis. After 21 d of culture, highly anisotropic sheets induced greater levels of production of type-I, type-III collagen, and thrombospondin-4. Therefore, SA has direct effects on MSC differentiation. These findings may also have ramifications of stem cell fate on other anisotropically stiff tissues, such as skeletal/cardiac muscles, ligaments, and bone. PMID:27377355

  12. Biophysical properties of dermal building-blocks affects extra cellular matrix assembly in 3D endogenous macrotissue.

    PubMed

    Urciuolo, F; Garziano, A; Imparato, G; Panzetta, V; Fusco, S; Casale, C; Netti, P A

    2016-03-01

    The fabrication of functional tissue units is one of the major challenges in tissue engineering due to their in vitro use in tissue-on-chip systems, as well as in modular tissue engineering for the construction of macrotissue analogs. In this work, we aim to engineer dermal tissue micromodules obtained by culturing human dermal fibroblasts into porous gelatine microscaffold. We proved that such stromal cells coupled with gelatine microscaffolds are able to synthesize and to assemble an endogenous extracellular matrix (ECM) resulting in tissue micromodules, which evolve their biophysical features over the time. In particular, we found a time-dependent variation of oxygen consumption kinetic parameters, of newly formed ECM stiffness and of micromodules self-aggregation properties. As consequence when used as building blocks to fabricate larger tissues, the initial tissue micromodules state strongly affects the ECM organization and maturation in the final macrotissue. Such results highlight the role of the micromodules properties in controlling the formation of three-dimensional macrotissue in vitro, defining an innovative design criterion for selecting tissue-building blocks for modular tissue engineering. PMID:26824879

  13. Innervation of Gill Lateral Cells in the Bivalve Mollusc Crassostrea virginica Affects Cellular Membrane Potential and Cilia Activity

    PubMed Central

    Catapane, Edward J; Nelson, Michael; Adams, Trevon; Carroll, Margaret A

    2016-01-01

    Gill lateral cells of Crassostrea virginica are innervated by the branchial nerve, which contains serotonergic and dopaminergic fibers that regulate cilia beating rate. Terminal release of serotonin or dopamine results in an increase or decrease, respectively, of cilia beating rate in lateral gill cells. In this study we used the voltage sensitive fluorescent probe DiBAC4(3) to quantify changes in gill lateral cell membrane potential in response to electrical stimulation of the branchial nerve or to applications of serotonin and dopamine, and correlate these changes to cilia beating rates. Application of serotonin to gill lateral cells caused prolonged membrane depolarization, similar to plateau potentials, while increasing cilia beating rate. Application of dopamine hyperpolarized the resting membrane while decreasing cilia beating rate. Low frequency (5 Hz) electrical stimulations of the branchial nerve, which cause terminal release of endogenous serotonin, or high frequency (20 Hz) stimulations, which cause terminal release of endogenous dopamine, had the same effects on gill lateral cell membrane potentials and cilia beating rate as the respective applications of serotonin or dopamine. The study shows that innervation of gill lateral cells by the branchial nerve affects membrane potential as well as cilia beating rate, and demonstrates a strong correlation between changes in membrane potential and regulation of cilia beating rate. The study furthers the understanding of serotonin and dopamine signaling in the innervation and regulation of gill cilia in bivalves. The study also shows that voltage sensitive fluorescent probes like DiBAC 4(3) can be successfully used as an alternative to microelectrodes to measure changes in membrane potential of ciliated gill cells and other small cells with fast moving cilia. PMID:27489887

  14. Monitoring of soil water storage along elevation transech on morphological diverse study-sites affected by soil erosion

    NASA Astrophysics Data System (ADS)

    Jaksik, Ondrej; Kodesova, Radka; Nikodem, Antonin; Fer, Miroslav; Klement, Ales; Kratina, Josef

    2015-04-01

    Soil water availability is one of the key factors determining plant growth. Spatial distribution of soil water content is influenced by many factors. For the field-scale, one of the most important factors is terrain and its shape. The goal of our study was to characterize soil water storage within the soil profile with respect to terrain attributes. Two morphologically diverse study sites were chosen, in order to monitor soil water storage during vegetation season. The first site Brumovice in located in the Southern Moravian Region. The original soil unit was Haplic Chernozem developed on loess, which was gradually degraded by soil erosion. In the steepest parts, due to substantial loss of soil material, soil is transformed to Regosol. As a result of consequently sedimentation of previously eroded material in toe slopes and terrain depressions colluvial soils are formed. The second site Vidim is placed in the Central Bohemia. Dominant soil unit in wider area is Haplic Luvisol on loess loam. Similar process of progressive soil transformation was identified. On each study site, two elevation transects were delimited, where each consists of 5 monitoring spots. Access tubes were installed in order to measure soil moisture in six different depths (10, 20, 30 40, 60 a 100 cm) using Profile Probe PR2. The monitoring was conducted during vegetation season: April - July 2012 in Brumovice and May - July 2013 in Vidim. The average soil water contents were calculated for following three layers: topsoil A (0-20 cm), subsoil B (20-40cm), and substrate (40-100cm). The soil water storage within the soil profile was also expressed. Sensors TMS3 were also used for continual soil water content monitoring in the depth of 0-15 cm. In addition undisturbed soil samples were taken from topsoil to measure soil hydraulic properties using the multistep outflow experiment. Data were used to assess retention ability of erosion affected soils. The soil water storage and particularly average

  15. Erythropoietin administration alone or in combination with endurance training affects neither skeletal muscle morphology nor angiogenesis in healthy young men.

    PubMed

    Larsen, Mads S; Vissing, Kristian; Thams, Line; Sieljacks, Peter; Dalgas, Ulrik; Nellemann, Birgitte; Christensen, Britt

    2014-10-01

    The aim was to investigate the ability of an erythropoiesis-stimulating agent (ESA), alone or in combination with endurance training, to induce changes in human skeletal muscle fibre and vascular morphology. In a comparative study, 36 healthy untrained men were randomly dispersed into the following four groups: sedentary-placebo (SP, n = 9); sedentary-ESA (SE, n = 9); training-placebo (TP, n = 10); or training-ESA (TE, n = 8). The ESA or placebo was injected once weekly. Training consisted of progressive bicycling three times per week for 10 weeks. Before and after the intervention period, muscle biopsies and magnetic resonance images were collected from the thigh muscles, blood was collected, body composition measured and endurance exercise performance evaluated. The ESA treatment (SE and TE) led to elevated haematocrit, and both ESA treatment and training (SE, TP and TE) increased maximal O2 uptake. With regard to skeletal muscle morphology, TP alone exhibited increases in whole-muscle cross-sectional area and fibre diameter of all fibre types. Also exclusively for TP was an increase in type IIa fibres and a corresponding decrease in type IIx fibres. Furthermore, an overall training effect (TP and TE) was statistically demonstrated in whole-muscle cross-sectional area, muscle fibre diameter and type IIa and type IIx fibre distribution. With regard to muscle vascular morphology, TP and TE both promoted a rise in capillary to muscle fibre ratio, with no differences between the two groups. There were no effects of ESA treatment on any of the muscle morphological parameters. Despite the haematopoietic effects of ESA, we provide novel evidence that endurance training rather than ESA treatment induces adaptational changes in angiogenesis and muscle morphology. PMID:25128327

  16. Plastic hatching timing by red-eyed treefrog embryos interacts with larval predator identity and sublethal predation to affect prey morphology but not performance.

    PubMed

    Touchon, Justin C; Wojdak, Jeremy M

    2014-01-01

    Many animals respond to predation risk by altering their morphology, behavior, or life-history. We know a great deal about the cues prey respond to and the changes to prey that can be induced by predation risk, but less is known about how plastic responses to predators may be affected by separate plastic responses occurring earlier in life, particularly during the embryonic period. Embryos of a broad array of taxa can respond to egg- or larval-stage risks by altering hatching timing, which may alter the way organisms respond to future predators. Using the red-eyed treefrog (Agalychnis callidryas), a model for understanding the effects of plasticity across life-stages, we assessed how the combined effects of induced variation in the timing of embryo hatching and variation in the larval predator community impacted tadpole morphology, pigmentation and swimming performance. We found that A. callidryas tadpoles developed deeper tail muscles and fins and darker pigmentation in response to fish predators, either when alone or in diverse community with other predators. Tadpoles altered morphology much less so to dragonfly naiads or water bugs. Interestingly, morphological responses to predators were also affected by induced differences in hatching age, with early and late-hatched tadpoles exhibiting different allometric relationships between tail height and body length in different predator environments. Beyond induced morphological changes, fish predators often damaged tadpoles' tails without killing them (i.e., sublethal predation), but these tadpoles swam equally quickly to those with fully intact tails. This was due to the fact that tadpoles with more damaged tails increased tail beats to achieve equal swimming speed. This study demonstrates that plastic phenotypic responses to predation risk can be influenced by a complex combination of responses to both the embryo and larval environments, but also that prey performance can be highly resilient to sublethal predation

  17. Plastic Hatching Timing by Red-Eyed Treefrog Embryos Interacts with Larval Predator Identity and Sublethal Predation to Affect Prey Morphology but Not Performance

    PubMed Central

    Touchon, Justin C.; Wojdak, Jeremy M.

    2014-01-01

    Many animals respond to predation risk by altering their morphology, behavior, or life-history. We know a great deal about the cues prey respond to and the changes to prey that can be induced by predation risk, but less is known about how plastic responses to predators may be affected by separate plastic responses occurring earlier in life, particularly during the embryonic period. Embryos of a broad array of taxa can respond to egg- or larval-stage risks by altering hatching timing, which may alter the way organisms respond to future predators. Using the red-eyed treefrog (Agalychnis callidryas), a model for understanding the effects of plasticity across life-stages, we assessed how the combined effects of induced variation in the timing of embryo hatching and variation in the larval predator community impacted tadpole morphology, pigmentation and swimming performance. We found that A. callidryas tadpoles developed deeper tail muscles and fins and darker pigmentation in response to fish predators, either when alone or in diverse community with other predators. Tadpoles altered morphology much less so to dragonfly naiads or water bugs. Interestingly, morphological responses to predators were also affected by induced differences in hatching age, with early and late-hatched tadpoles exhibiting different allometric relationships between tail height and body length in different predator environments. Beyond induced morphological changes, fish predators often damaged tadpoles’ tails without killing them (i.e., sublethal predation), but these tadpoles swam equally quickly to those with fully intact tails. This was due to the fact that tadpoles with more damaged tails increased tail beats to achieve equal swimming speed. This study demonstrates that plastic phenotypic responses to predation risk can be influenced by a complex combination of responses to both the embryo and larval environments, but also that prey performance can be highly resilient to sublethal predation

  18. Effect of ZnO morphology on affecting bactericidal property of ultra high molecular weight polyethylene biocomposite.

    PubMed

    Sharma, Rajeev Kumar; Agarwal, Meenakshi; Balani, Kantesh

    2016-05-01

    Bacterial infection of implants can be controlled by selective trapping of bacteria, followed with consequent killing by targeted antibacterial agents. Herein, the role of various ZnO morphologies, viz. micro-rods (R), nanoparticles (NP), and micro-disks (D) on antibacterial efficacy of ZnO via release of Zn(2+) and H2O2 is assessed, both as isolated powders and via incorporating them in cytocompatible ultra high molecular weight polyethylene (UHMWPE). Though ZnO is antibacterial, interestingly, all ZnO morphologies elicited a supportive growth of gram-negative bacteria (Escherichia coli) in culture medium (until 28-35μg/ml). But, all ZnO morphologies did elicit bactericidal effect on gram positive bacteria (Staphylococcus aureus or Staphylococcus epidermidis) both in culture medium (for 0-2.5μg/ml) or when incorporated (5-20wt.%) into UHMWPE. The bactericidal mechanisms were quantified for various ZnO morphologies via: (i) H2O2 production, (ii) Zn(2+) release, and (iii) the presence of surface oxygen vacancies. On one hand, where only ZnO(NP) elicited release of H2O2 in the absence of light, maximum Zn(2+) release was elicited by ZnO(D). Interestingly, when ZnO is incorporated as reinforcement (5-20wt.%), its antibacterial action against E. coli was vividly observed due to selective proliferation of bacteria only on friendly UHMWPE matrix. Hence, luring bacteria on affable UHMWPE surface can be complemented with their targeted killing by ZnO present in composite. PMID:26952491

  19. Extended incubation affects larval morphology, hatching success and starvation resistance in a terrestrially spawning fish, Galaxias maculatus (Jenyns 1842).

    PubMed

    Semmens, D; Swearer, S E

    2011-10-01

    The effect of extended incubation (delayed hatching) on larval morphology in the terrestrially spawning common galaxias Galaxias maculatus was investigated by inducing larvae to hatch 1 and 2 weeks after the normal 2 week incubation period. After 1 week of extended incubation, larvae were larger (longer in standard length, L(S), and greater in body depth) compared to controls (larvae that experienced normal incubation durations). After 2 weeks of extended incubation, larvae were smaller (shorter in L(S) and smaller in body depth) than larvae that experienced 1 week of extended incubation. Furthermore, eye area increased while yolk-sac size decreased monotonically with increasing incubation duration. These results suggest that larvae experiencing long periods of extended incubation are using somatic tissue to meet their metabolic demands. Larvae that experienced 2 weeks of extended incubation succumbed to starvation sooner than control larvae, but hatching success was not significantly different. Temperature mediated the effect of extended incubation on the morphology of larvae at hatching, most likely, through its effects on developmental rate and efficiency of yolk utilization. This study demonstrates some of the consequences of terrestrial spawning with extended incubation, which will assist in determining why this intriguing behaviour has evolved several times in a diverse range of taxa. PMID:21967585

  20. The Identification of Transposon-Tagged Mutations in Essential Genes That Affect Cell Morphology in Saccharomyces Cerevisiae

    PubMed Central

    Chun, K. T.; Goebl, M. G.

    1996-01-01

    The yeast Saccharomyces cerevisiae reproduces by budding, and many genes are required for proper bud development. Mutations in some of these genes cause cells to die with an unusual terminal morphology--elongated or otherwise aberrantly shaped buds. To gain insight into bud development, we set out to identify novel genes that encode proteins required for proper bud morphogenesis. Previous studies screened collections of conditional mutations to identify genes required for essential functions, including bud formation. However, genes that are not susceptible to the generation of mutations that cause a conditional phenotype will not be identified in such screens. To identify a more comprehensive collection of mutants, we used transposon mutagenesis to generate a large collection of lethal disruption mutations. This collection was used to identify 209 mutants with disruptions that cause an aberrant terminal bud morphology. The disruption mutations in 33 of these mutants identify three previously uncharacterized genes as essential, and the mutant phenotypes suggest roles for their products in bud morphogenesis. PMID:8770583

  1. Do calcium-mediated cellular signalling pathways, prostaglandin E2 (PGE2), estrogen or progesterone receptor antagonists, or bacterial endotoxins affect bovine placental function in vitro?

    PubMed

    Weems, Y S; Randel, R D; Carstens, G E; Welsh, T H; Weems, C W

    2004-04-01

    media treated with RU-486 increased (P < or = 0.05) at 4 and 8 h compared to vehicle controls and was not affected by other treatments (P > or = 0.05). Concentrations of PGE2 in media at 4 and 8 h were lower (P < or = 0.05) when compared to controls except treatment with PGE2 at 4 and 8h and RU-486 at 8h (P > or = 0.05). PGF2alpha was increased (P < or = 0.05) by RU-486 at 8h and no other treatment affected PGF2alpha at 4 or 8 h (P < or = 0.05). In conclusion, modulators of cellular calcium signalling pathways given alone do not affect bovine placental progesterone secretion at the days studied and progesterone receptor-mediated events appear to suppress placental progesterone, PGF2alpha, and PGE2 secretion in cattle. In addition, PGE2 does not appear to regulate bovine placental progesterone secretion when the corpus luteum is functional and bacterial endotoxin does not appear to affect bovine placental secretion of PGF2alpha or PGE2. PMID:15287156

  2. Cellular interference in craniofrontonasal syndrome: males mosaic for mutations in the X-linked EFNB1 gene are more severely affected than true hemizygotes

    PubMed Central

    Twigg, Stephen R.F.; Babbs, Christian; van den Elzen, Marijke E.P.; Goriely, Anne; Taylor, Stephen; McGowan, Simon J.; Giannoulatou, Eleni; Lonie, Lorne; Ragoussis, Jiannis; Akha, Elham Sadighi; Knight, Samantha J.L.; Zechi-Ceide, Roseli M.; Hoogeboom, Jeannette A.M.; Pober, Barbara R.; Toriello, Helga V.; Wall, Steven A.; Rita Passos-Bueno, M.; Brunner, Han G.; Mathijssen, Irene M.J.; Wilkie, Andrew O.M.

    2013-01-01

    Craniofrontonasal syndrome (CFNS), an X-linked disorder caused by loss-of-function mutations of EFNB1, exhibits a paradoxical sex reversal in phenotypic severity: females characteristically have frontonasal dysplasia, craniosynostosis and additional minor malformations, but males are usually more mildly affected with hypertelorism as the only feature. X-inactivation is proposed to explain the more severe outcome in heterozygous females, as this leads to functional mosaicism for cells with differing expression of EPHRIN-B1, generating abnormal tissue boundaries—a process that cannot occur in hemizygous males. Apparently challenging this model, males occasionally present with a more severe female-like CFNS phenotype. We hypothesized that such individuals might be mosaic for EFNB1 mutations and investigated this possibility in multiple tissue samples from six sporadically presenting males. Using denaturing high performance liquid chromatography, massively parallel sequencing and multiplex-ligation-dependent probe amplification (MLPA) to increase sensitivity above standard dideoxy sequencing, we identified mosaic mutations of EFNB1 in all cases, comprising three missense changes, two gene deletions and a novel point mutation within the 5′ untranslated region (UTR). Quantification by Pyrosequencing and MLPA demonstrated levels of mutant cells between 15 and 69%. The 5′ UTR variant mutates the stop codon of a small upstream open reading frame that, using a dual-luciferase reporter construct, was demonstrated to exacerbate interference with translation of the wild-type protein. These results demonstrate a more severe outcome in mosaic than in constitutionally deficient males in an X-linked dominant disorder and provide further support for the cellular interference mechanism, normally related to X-inactivation in females. PMID:23335590

  3. How do changes to plate thickness, length, and face-connectivity affect femoral cancellous bone's density and surface area? An investigation using regular cellular models.

    PubMed

    Anderson, I A; Carman, J B

    2000-03-01

    Models of regular cellular-solids representing femoral head 'medial group' bone were used to (1) compare thickness data for plate-like and beam-like structures at realistic surface areas and densities; (2) test the validity of a standard formula for trabecular thickness (Tb.Th); and (3) study how systematic changes in cancellous bone thicknesses, spacing, and face-connectivity affect relative density and surface area. Models of different face-connectivities, produced by plate removal from the unit cell, were fitted to bone density and surface area data. The medial group bone was anisotropic: the supero-inferior (SI) direction was the principal direction for bone plate alignment and the plane normal to this had the largest number of bone/void intersections per unit line length (P(I)). A comparison of boundary perimeter per unit area data, in planes normal to SI, with surface area data placed the medial group bone between prismatic structures in which walls are parallel to one principal direction and isotropic structures. Selective removal of plates from a closed-cell model produced a similar result. For the same relative density and surface-area, plate-like models had significantly thinner cross-sections than beam-like models. The formula for Tb.Th produced overestimates of model plate thickness by up to 20% at realistic femoral cancellous densities. Trends in data on surface area to volume ratio and density observed on sampled medial group bone could be simulated by plate thickness changes on models of intermediate face-connectivity (approximately 1.5) or by plate removal from models with relatively thick and short (low aspect-ratio) plates. The latter mechanism is unrealistic for it resulted in beam-like structures at low 'medial group' densities, an architecture unlike the predominantly plate-like bone in the sample. PMID:10673116

  4. Cortisol affects tight junction morphology between pavement cells of rainbow trout gills in single-seeded insert culture.

    PubMed

    Sandbichler, Adolf Michael; Farkas, Julia; Salvenmoser, Willi; Pelster, Bernd

    2011-12-01

    A primary culture system of rainbow trout gill pavement cells grown on permeable support (single-seeded insert, SSI) was used to examine histological and physiological changes induced by the addition of the corticosteroid hormone cortisol. Pavement cell epithelia were cultured under symmetrical conditions (L15 apical/L15 basolateral) and developed a high transepithelial resistance (TER, 6.84 ± 1.99 kΩ cm(2), mean ± SEM) with a low phenol red diffusion rate (PRD, 0.15 ± 0.03 μmol l(-1)/day). Addition of cortisol to the basolateral compartment increased TER twofold and reduced PRD threefold over a 5-day period. A similar increase in TER could be seen after 24 h apical freshwater (FW) in control cultures. In cortisol-treated cultures FW exposure did not change TER, but PRD increased significantly. Histochemical staining of the cytoskeleton of cells in SSI culture revealed a morphological partitioning into a single mucosal layer of polarized, polygonal cells featuring cortical F-actin rings which were comparable to F-actin rings of epithelial cells on the lamellar and filamental surface, and several unorganized serosal layers of cells with F-actin stress fibers. Addition of cortisol increased cell density by 18% and in the mucosal layer it led to smaller, less polygonal cells with increased height and increased cell contact area. In transmission electron microscopic images two pairs of cytoplasmatic electron-dense structures confining the zonula occludens apically and basally toward the zonula adhaerens were found. Addition of cortisol increased the distance between those paired structures, hence led to deeper tight junctions. The cortisol-induced increase in barrier properties, therefore, involves a structural fortification of the tight junctions which was not generally modified by a short 24-h apical freshwater stress. These results identify cortisol as a regulator of tight junction morphology between pavement cells of euryhaline fish such as the

  5. Electrical dual-sensing method for real-time quantitative monitoring of cell-secreted MMP-9 and cellular morphology during migration process.

    PubMed

    Tran, Trong Binh; Nguyen, Phuong Diem; Baek, Changyoon; Min, Junhong

    2016-03-15

    MMP-9 (92 kDa gelatinease), which is member of matrix metalloproteinases (MMPs) family, plays a crucial role in the breakdown of extracellular matrix (ECM) by degrading the major components of ECM that lead to tumor cell invasion and metastasis through the basement membrane. Our study presents the on-chip dual-sensing device for rapid detection of cell-secreted MMP-9 and corresponding cell morphology changes in real-time domain. The device consists of 2 sensing platforms (both are interdigitated array microelectrodes - IDAMs) within 1 common fluidic chamber: one detects the cell morphology responses via Electric Cell-substrate Impedance Sensing (ECIS) technique, meanwhile the other records the cleavage effect between cell-secreted MMP-9 and the surface immobilized peptide via the capacitance-based sensing method. Thanks to the selectivity of designed peptide, this approach allows the rapid and specific detection of MMP-9. In comparison with gold standard ELISA assay, the detection time was significantly reduced from over 4h to within 30 min with the wide detection range from 10 pM to 10nM. Finally, this study provides the novel model for MMP-9 protease direct detection from living cell and new insights in multi-purpose detection of cancer associated enzyme and cell migration behavior. PMID:26485177

  6. Bud endophytes of Scots pine produce adenine derivatives and other compounds that affect morphology and mitigate browning of callus cultures.

    PubMed

    Pirttilä, Anna Maria; Joensuu, Päivi; Pospiech, Helmut; Jalonen, Jorma; Hohtola, Anja

    2004-06-01

    Endophytes are found in meristematic bud tissues of Scots pine (Pinus sylvestris L.) especially prior to growth, which would suggest their involvement in growth of the bud. To test this hypothesis, production of phytohormones by two bacterial (Methylobacterium extorquens, Pseudomonas synxantha) and one fungal endophyte (Rhodotorula minuta) was studied by mass spectrometry. The most common gibberellins, auxins, or cytokinins were not detected in the fractions studied. Instead, M. extorquens and R. minuta produced adenine derivatives that may be used as precursors in cytokinin biosynthesis. A plant tissue culture medium was conditioned with the endophytes, and pine tissue cultures were started on the media. Tetracycline inhibited callus production, which was restored on the endophyte-conditioned media. In addition, conditioning mitigated browning of the Scots pine explants. However, a decrease in tissue size was observed on the endophyte-conditioned media. Addition of adenosine monophosphate in the plant culture medium restored callus production and increased growth of the tissues, but had no effect on browning. Therefore, production of adenine ribosides by endophytes may play some role in the morphological effect observed in the pine tissues. PMID:15153198

  7. CebR as a master regulator for cellulose/cellooligosaccharide catabolism affects morphological development in Streptomyces griseus.

    PubMed

    Marushima, Kazuya; Ohnishi, Yasuo; Horinouchi, Sueharu

    2009-10-01

    Streptomyces griseus mutants exhibiting deficient glucose repression of beta-galactosidase activity on lactose-containing minimal medium supplemented with a high concentration of glucose were isolated. One of these mutants had a 12-bp deletion in cebR, which encodes a LacI/GalR family regulator. Disruption of cebR in the wild-type strain caused the same phenotype as the mutant, indicating that CebR is required for glucose repression of beta-galactosidase activity. Recombinant CebR protein bound to a 14-bp inverted-repeat sequence (designated the CebR box) present in the promoter regions of cebR and the putative cellobiose utilization operon, cebEFG-bglC. The DNA-binding activity of CebR was impaired by cellooligosaccharides, including cellobiose, cellotriose, cellotetraose, cellopentaose, and cellohexaose. In agreement with this observation, transcription from the cebE and cebR promoters was greatly enhanced by the addition of cellobiose to the medium. Seven other genes containing one or two CebR boxes in their upstream regions were found in the S. griseus genome. Five of these genes encode putative secreted proteins: two cellulases, a cellulose-binding protein, a pectate lyase, and a protein of unknown function. These five genes and cebEFG-bglC were transcribed at levels 4 to 130 times higher in the DeltacebR mutant than in the wild-type strain, as determined by quantitative reverse transcription-PCR. These findings indicate that CebR is a master regulator of cellulose/cellooligosaccharide catabolism. Unexpectedly, the DeltacebR mutant formed very few aerial hyphae on lactose-containing medium, demonstrating a link between carbon source utilization and morphological development. PMID:19648249

  8. Brain morphological alterations and cellular metabolic changes in patients with generalized anxiety disorder: A combined DARTEL-based VBM and (1)H-MRS study.

    PubMed

    Moon, Chung-Man; Jeong, Gwang-Woo

    2016-05-01

    Generalized anxiety disorder (GAD) is characterized by emotional dysregulation and cognitive deficit in conjunction with brain morphometric and metabolic alterations. This study assessed the combined neural morphological deficits and metabolic abnormality in patients with GAD. Thirteen patients with GAD and 13 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted MRI and proton magnetic resonance spectroscopy ((1)H-MRS) at 3Tesla. In this study, the combination of voxel-based morphometry (VBM) and (1)H-MRS was used to assess the brain morphometric and metabolic alterations in GAD. The patients showed significantly reduced white matter (WM) volumes in the midbrain (MB), precentral gyrus (PrG), dorsolateral prefrontal cortex (DLPFC) and anterior limb of the internal capsule (ALIC) compared to the controls. In MRS study, the choline/creatine (Cho/Cr) and choline/N-acetylaspartate (Cho/NAA) ratios in the DLPFC were significantly lower in the patients. Particularly, the WM volume variation of the DLPFC was positively correlated with both of the Cho/Cr and Cho/NAA ratios in patients with GAD. This study provides an evidence for the association between the morphometric deficit and metabolic changes in GAD. This finding would be helpful to understand the neural dysfunction and pathogenesis in connection with cognitive impairments in GAD. PMID:26708039

  9. Perinatal exposure to bisphenol-A inhibits synaptogenesis and affects the synaptic morphological development in offspring male mice.

    PubMed

    Xu, Xiaohong; Xie, Lingdan; Hong, Xing; Ruan, Qin; Lu, Hongfei; Zhang, Qin; Zhang, Guangxia; Liu, Xingyi

    2013-05-01

    Our previous study indicated that perinatal exposure to low-dose BPA, one of the most common environmental endocrine disrupters, alters behavioral development in offspring mice. Given that synaptic structure of the hippocampus is closely related to behaviors, in the present study, we examined the effects of perinatal exposure to BPA (0.04, 0.4, and 4.0 mg kg(-1) day(-1)) on the synaptic density and the synaptic structural modification of pyramidal cells in hippocampus region CA1 and the expressions of synaptic proteins such as synapsin I and PSD-95 and glutamate NMDA and AMPA receptors in male offspring mice on postnatal day (PND) 14, 21, and 56. The results of electron microscope measurement showed that BPA significantly reduced the numeric synaptic density and altered the structural modification of synaptic interface of pyramidal cells with the enlarged synaptic cleft, the shortened active zone, and the thinned postsynaptic density (PSD) on PND 14, 21, and 56 and the increased curvature of synaptic interface on PND 14 and 21. Further analyses of Western blot indicated that BPA markedly reduced the levels of synapsin I and PSD-95 on PND 14, 21, and 56 and down-regulated NMDA receptor subunit NR1 and AMPA receptor subunit GluR1 during development and young adulthood. These results suggest that perinatal exposure to low level of BPA inhibits synaptogenesis and affects synaptic structural modification after birth. The reduced expressions of synaptic proteins synapsin I and PSD-95 and glutamate NMDA and AMPA receptors may be involved in the negative changes in the synaptic plasticity. PMID:23490186

  10. Barrier Island Morphology and Sediment Characteristics Affect the Recovery of Dune Building Grasses following Storm-Induced Overwash

    PubMed Central

    Brantley, Steven T.; Bissett, Spencer N.; Young, Donald R.; Wolner, Catherine W. V.; Moore, Laura J.

    2014-01-01

    Barrier islands are complex and dynamic systems that provide critical ecosystem services to coastal populations. Stability of these systems is threatened by rising sea level and the potential for coastal storms to increase in frequency and intensity. Recovery of dune-building grasses following storms is an important process that promotes topographic heterogeneity and long-term stability of barrier islands, yet factors that drive dune recovery are poorly understood. We examined vegetation recovery in overwash zones on two geomorphically distinct (undisturbed vs. frequently overwashed) barrier islands on the Virginia coast, USA. We hypothesized that vegetation recovery in overwash zones would be driven primarily by environmental characteristics, especially elevation and beach width. We sampled species composition and environmental characteristics along a continuum of disturbance from active overwash zones to relict overwash zones and in adjacent undisturbed environments. We compared species assemblages along the disturbance chronosequence and between islands and we analyzed species composition data and environmental measurements with Canonical Correspondence Analysis to link community composition with environmental characteristics. Recovering and geomorphically stable dunes were dominated by Ammophila breviligulata Fernaud (Poaceae) on both islands while active overwash zones were dominated by Spartina patens (Aiton) Muhl. (Poaceae) on the frequently disturbed island and bare sand on the less disturbed island. Species composition was associated with environmental characteristics only on the frequently disturbed island (p = 0.005) where A. breviligulata was associated with higher elevation and greater beach width. Spartina patens, the second most abundant species, was associated with larger sediment grain size and greater sediment size distribution. On the less frequently disturbed island, time since disturbance was the only factor that affected community

  11. Waterlogging in late dormancy and the early growth phase affected root and leaf morphology in Betula pendula and Betula pubescens seedlings.

    PubMed

    Wang, Ai-Fang; Roitto, Marja; Sutinen, Sirkka; Lehto, Tarja; Heinonen, Jaakko; Zhang, Gang; Repo, Tapani

    2016-01-01

    The warmer winters of the future will increase snow-melt frequency and rainfall, thereby increasing the risk of soil waterlogging and its effects on trees in winter and spring at northern latitudes. We studied the morphology of roots and leaves of 1-year-old silver birch (Betula pendula Roth) and pubescent birch (Betula pubescens Ehrh.) seedlings exposed to waterlogging during dormancy or at the beginning of the growing season in a growth-chamber experiment. The experiment included 4-week dormancy (Weeks 1-4), a 4-week early growing season (Weeks 5-8) and a 4-week late growing season (Weeks 9-12). The treatments were: (i) no waterlogging, throughout the experiment ('NW'); (ii) 4-week waterlogging during dormancy (dormancy waterlogging 'DW'); (iii) 4-week waterlogging during the early growing season (growth waterlogging 'GW'); and (iv) 4-week DW followed by 4-week GW during the early growing season ('DWGW'). Dormancy waterlogging affected the roots of silver birch and GW the roots and leaf characteristics of both species. Leaf area was reduced in both species by GW and DWGW. In pubescent birch, temporarily increased formation of thin roots was seen in root systems of GW seedlings, which suggests an adaptive mechanism with respect to excess soil water. Additionally, the high density of non-glandular trichomes and their increase in DWGW leaves were considered possible morphological adaptations to excess water in the soil, as was the constant density of stem lenticels during stem-diameter growth. The higher density in glandular trichomes of DWGW silver birch suggests morphological acclimation in that species. The naturally low density of non-glandular trichomes, low density of stem lenticels in waterlogged seedlings and decrease in root growth seen in DWGW and DW silver birch seedlings explain, at least partly, why silver birch grows more poorly relative to pubescent birch in wet soils. PMID:26420790

  12. The H3K4me3 Histone Demethylase Fbxl10 Is a Regulator of Chemokine Expression, Cellular Morphology, and the Metabolome of Fibroblasts

    PubMed Central

    Janzer, Andreas; Stamm, Katrin; Becker, Astrid; Zimmer, Andreas; Buettner, Reinhard; Kirfel, Jutta

    2012-01-01

    Fbxl10 (Jhdm1b/Kdm2b) is a conserved and ubiquitously expressed member of the JHDM (JmjC domain-containing histone demethylase) family. Fbxl10 was implicated in the demethylation of H3K4me3 or H3K36me2 thereby removing active chromatin marks and inhibiting gene transcription. Apart from the JmjC domain, Fbxl10 consists of a CxxC domain, a PHD domain, and an Fbox domain. By purifying the JmjC and the PHD domain of Fbxl10 and using different approaches we were able to characterize the properties of these domains in vitro. Our results suggest that Fbxl10 is rather a H3K4me3 than a H3K36me2 histone demethylase. The PHD domain exerts a dual function in binding H3K4me3 and H3K36me2 and exhibiting E3 ubiquitin ligase activity. We generated mouse embryonic fibroblasts stably overexpressing Fbxl10. These cells reveal an increase in cell size but no changes in proliferation, mitosis, or apoptosis. Using a microarray approach we were able to identify potentially new target genes for Fbxl10 including chemokines, the noncoding RNA Xist, and proteins involved in metabolic processes. Additionally, we found that Fbxl10 is recruited to the promoters of Ccl7, Xist, Crabp2, and RipK3. Promoter occupancy by Fbxl10 was accompanied by reduced levels of H3K4me3 but unchanged levels of H3K36me2. Furthermore, knockdown of Fbxl10 using small interfering RNA approaches showed inverse regulation of Fbxl10 target genes. In summary, our data reveal a regulatory role of Fbxl10 in cell morphology, chemokine expression, and the metabolic control of fibroblasts. PMID:22825849

  13. Gonadotropin-releasing hormone induces miR-132 and miR-212 to regulate cellular morphology and migration in immortalized LbetaT2 pituitary gonadotrope cells.

    PubMed

    Godoy, Joseph; Nishimura, Marin; Webster, Nicholas J G

    2011-05-01

    GnRH is central to the regulation of reproductive function. It acts on pituitary gonadotropes to stimulate LH and FSH synthesis and secretion. We had previously presented evidence for translational control of LHβ synthesis; therefore we investigated whether micro-RNAs might play a role in GnRH regulation in LβT2 cells. We show here that GnRH strongly induces the AK006051 gene transcript that encodes two micro-RNAs, miR-132 and miR-212, within the first intron. We show furthermore that the AK006051 promoter region is highly GnRH responsive. We verify that the p250Rho GTPase activating protein (GAP) is a target of miR-132/212 and show that GnRH treatment leads to a decrease in mRNA and protein expression. This reduction is blocked by an anti-miR to miR-132/212 and mimicked by a pre-miR-132. GnRH inhibits p250RhoGAP expression through a miR-132/212 response element within the 3'-untranslated region. The loss of p250RhoGAP expression leads to activation of Rac and marked increases in both the number and length of neurite-like processes extending from the cell. Knockdown of p250RhoGAP by small interfering RNA induces the same morphological changes observed with GnRH treatment. In addition, loss of p250RhoGAP causes an increase in cellular motility. Our findings suggest a novel pathway regulating long-term changes in cellular motility and process formation via the GnRH induction of miR-132/212 with the subsequent down-regulation of p250RhoGAP. PMID:21372146

  14. CELLULAR PATHOGENESIS OF DIABETIC GASTROENTEROPATHY

    PubMed Central

    Ördög, Tamás; Hayashi, Yujiro; Gibbons, Simon J.

    2010-01-01

    SUMMARY Gastroenteropathy manifesting in upper gastrointestinal symptoms, delayed gastric emptying, constipation, diarrhea and fecal incontinence occurs frequently in patients with diabetes mellitus and represents a significant health care burden. Current treatments are largely symptomatic and ineffective. Better understanding of the cellular and molecular pathogenesis of these disorders is required for the development of more effective therapies. Recent advances in our understanding of the inherent, high-level complexities of the control systems that execute and regulate gastrointestinal motility, together with the utilization of new experimental models and sophisticated physiological, morphological and molecular techniques have lead to the realization that diabetic gastroenteropathies cannot be ascribed to any singular defect or dysfunction. In fact, these disorders are multifactorial and involve a spectrum of metabolic and dystrophic changes that can potentially affect all key components of motor control including the systemic autonomic and enteric nervous systems, interstitial cells of Cajal and smooth muscle cells. Candidate pathomechanisms are also varied and include imbalance between pro- and anti-oxidative factors, altered trophic stimuli to mature cells and their progenitors, and, possibly, autoimmune factors. The goal of this paper is to review the cellular changes underlying diabetic gastroenteropathies and their potential causes, with particular focus on functional interactions between various cell types. It is proposed that diabetic gastroenteropathies should be considered a form of gastrointestinal neuromuscular dystrophy rather than a “functional” disorder. Future research should identify ways to block cytotoxic factors, support the regeneration of damaged cells and translate the experimental findings into new treatment modalities. PMID:19829287

  15. Loss of Cellular Sialidases Does Not Affect the Sialylation Status of the Prion Protein but Increases the Amounts of Its Proteolytic Fragment C1

    PubMed Central

    Katorcha, Elizaveta; Klimova, Nina; Makarava, Natallia; Savtchenko, Regina; Pan, Xuefang; Annunziata, Ida; Takahashi, Kohta; Miyagi, Taeko; Pshezhetsky, Alexey V.; d’Azzo, Alessandra; Baskakov, Ilia V.

    2015-01-01

    The central molecular event underlying prion diseases involves conformational change of the cellular form of the prion protein (PrPC), which is a sialoglycoprotein, into the disease-associated, transmissible form denoted PrPSc. Recent studies revealed a correlation between the sialylation status of PrPSc and incubation time to disease and introduced a new hypothesis that progression of prion diseases could be controlled or reversed by altering the sialylation level of PrPC. Of the four known mammalian sialidases, the enzymes that cleave off sialic acid residues, only NEU1, NEU3 and NEU4 are expressed in the brain. To test whether cellular sialidases control the steady-state sialylation level of PrPC and to identify the putative sialidase responsible for desialylating PrPC, we analyzed brain-derived PrPC from knockout mice deficient in Neu1, Neu3, Neu4, or from Neu3/Neu4 double knockouts. Surprisingly, no differences in the sialylation of PrPC or its proteolytic product C1 were noticed in any of the knockout mice tested as compared to the age-matched controls. However, significantly higher amounts of the C1 fragment relative to full-length PrPC were detected in the brains of Neu1 knockout mice as compared to WT mice or to the other knockout mice. Additional experiments revealed that in neuroblastoma cell line the sialylation pattern of C1 could be changed by an inhibitor of sialylatransferases. In summary, this study suggests that targeting cellular sialidases is apparently not the correct strategy for altering the sialylation levels of PrPC, whereas modulating the activity of sialylatransferases might offer a more promising approach. Our findings also suggest that catabolism of PrPC involves its α-cleavage followed by desialylation of the resulting C1 fragments by NEU1 and consequent fast degradation of the desialylated products. PMID:26569607

  16. Tetracapsuloides bryosalmonae infection affects the expression of genes involved in cellular signal transduction and iron metabolism in the kidney of the brown trout Salmo trutta.

    PubMed

    Kumar, Gokhlesh; Sarker, Subhodeep; Menanteau-Ledouble, Simon; El-Matbouli, Mansour

    2015-06-01

    Tetracapsuloides bryosalmonae is an enigmatic endoparasite which causes proliferative kidney disease in various species of salmonids in Europe and North America. The life cycle of the European strain of T. bryosalmonae generally completes in an invertebrate host freshwater bryozoan and vertebrate host brown trout (Salmo trutta) Linnaeus, 1758. Little is known about the gene expression in the kidney of brown trout during the developmental stages of T. bryosalmonae. In the present study, quantitative real-time PCR was applied to quantify the target genes of interest in the kidney of brown trout at different time points of T. bryosalmonae development. PCR primers specific for target genes were designed and optimized, and their gene expression levels were quantified in the cDNA kidney samples using SYBR Green Supermix. Expression of Rab GDP dissociation inhibitor beta, integral membrane protein 2B, NADH dehydrogenase 1 beta subcomplex subunit 6, and 26S protease regulatory subunit S10B were upregulated significantly in infected brown trout, while the expression of the ferritin M middle subunit was downregulated significantly. These results suggest that host genes involved in cellular signal transduction, proteasomal activities, including membrane transporters and cellular iron storage, are differentially upregulated or downregulated in the kidney of brown trout during parasite development. The gene expression pattern of infected renal tissue may support the development of intraluminal sporogonic stages of T. bryosalmonae in the renal tubular lumen of brown trout which may facilitate the release of viable parasite spores to transmit to the invertebrate host bryozoan. PMID:25786607

  17. NMDA-R inhibition affects cellular process formation in Tilapia melanocytes; a model for pigmented adrenergic neurons in process formation and retraction.

    PubMed

    Ogundele, Olalekan Michael; Okunnuga, Adetokunbo Adedotun; Fabiyi, Temitope Deborah; Olajide, Olayemi Joseph; Akinrinade, Ibukun Dorcas; Adeniyi, Philip Adeyemi; Ojo, Abiodun Ayodele

    2014-06-01

    Parkinson's disease has long been described to be a product of dopamine and (or) melanin loss in the substanstia nigra (SN). Although most studies have focused on dopaminergic neurons, it is important to consider the role of pigment cells in the etiology of the disease and to create an in vitro live cell model for studies involving pigmented adrenergic cells of the SN in Parkinsonism. The Melanocytes share specific features with the pigmented adrenergic neurons as both cells are pigmented, contain adrenergic receptors and have cellular processes. Although the melanocyte cellular processes are relatively short and observable only when stimulated appropriately by epinephrine and other factors or molecules. This study employs the manipulation of N-Methyl-D-Aspartate Receptor (NMDA-R), a major receptor in neuronal development, in the process formation pattern of the melanocyte in order to create a suitable model to depict cellular process elongation and shortening in pigmented adrenergic cells. NMDA-R is an important glutamate receptor implicated in neurogenesis, neuronal migration, maturation and cell death, thus we investigated the role of NMDA-R potentiation by glutamate/KCN and its inhibition by ketamine in the behavior of fish scale melanocytes in vitro. This is aimed at establishing the regulatory role of NMDA-R in this cell type (melanocytes isolated form Tilapia) in a similar manner to what is observable in the mammalian neurons. In vitro live cell culture was prepared in modified Ringer's solution following which the cells were treated as follows; Control, Glutamate, Ketamine, Glutamate + Ketamine, KCN + Ketamine and KCN. The culture was maintained for 10 min and the changes were captured in 3D-Time frame at 0, 5 and 10 min for the control and 5, 7 and 10 min for each of the treatment category. Glutamate treatment caused formation of short cellular processes localized directly on the cell body while ketamine treatment (inhibition of NMDA-R) facilitated

  18. Concentration of Fibrin and Presence of Plasminogen Affect Proliferation, Fibrinolytic Activity, and Morphology of Human Fibroblasts and Keratinocytes in 3D Fibrin Constructs

    PubMed Central

    Reinertsen, Erik; Skinner, Michael; Wu, Benjamin

    2014-01-01

    Fibrin is a hemostatic protein found in the clotting cascade. It is used in the operating room to stop bleeding and deliver cells and growth factors to heal wounds. However, formulations of clinically approved fibrin are optimized for hemostasis, and the extent to which biochemical and physical cues in fibrin mediate skin cell behavior is not fully understood nor utilized in the design of biomaterials. To determine if the concentration of fibrinogen and the presence of plasminogen affect cell behavior relevant to wound healing, we fabricated three-dimensional fibrin constructs made from 5, 10, or 20 mg/mL of clinical fibrin or plasminogen-depleted (PD) fibrin. We cultured dermal fibroblasts or epidermal keratinocytes in these constructs. Fibroblasts proliferated similarly in both types of fibrin, but keratinocytes proliferated more in low concentrations of clinical fibrin and less in PD fibrin. Clinical fibrin constructs with fibroblasts were less stiff and degraded faster than PD fibrin constructs with fibroblasts. Similarly, keratinocytes degraded clinical fibrin, but not PD fibrin. Fibroblast spreading varied with fibrin concentration in both types of fibrin. In conclusion, the concentration of fibrinogen and the presence of plasminogen affect fibroblast and keratinocyte proliferation, morphology, and fibrin degradation. Creating materials with heterogeneous regions of fibrin formulations and concentrations could be a novel strategy for controlling the phenotype of encapsulated fibroblasts and keratinocytes, and the subsequent biomechanical properties of the construct. However, other well-investigated aspects of wound healing remain to be utilized in the design of fibrin biomaterials, such as autocrine and paracrine signaling between fibroblasts, keratinocytes, and immune cells. PMID:24738616

  19. Clostridium botulinum type C hemagglutinin affects the morphology and viability of cultured mammalian cells via binding to the ganglioside GM3.

    PubMed

    Sugawara, Yo; Iwamori, Masao; Matsumura, Takuhiro; Yutani, Masahiro; Amatsu, Sho; Fujinaga, Yukako

    2015-09-01

    Botulinum neurotoxin is conventionally divided into seven serotypes, designated A-G, and is produced as large protein complexes through associations with non-toxic components, such as hemagglutinin (HA) and non-toxic non-HA. These non-toxic proteins dramatically enhance the oral toxicity of the toxin complex. HA is considered to have a role in toxin transport through the intestinal epithelium by carbohydrate binding and epithelial barrier-disrupting activity. Type A and B HAs disrupt E-cadherin-mediated cell adhesion, and, in turn, the intercellular epithelial barrier. Type C HA (HA/C) disrupts the barrier function by affecting cell morphology and viability, the mechanism of which remains unknown. In this study, we identified GM3 as the target molecule of HA/C. We found that sialic acid binding of HA is essential for the activity. It was abolished when cells were pre-treated with an inhibitor of ganglioside synthesis. Consistent with this, HA/C bound to a-series gangliosides in a glycan array. In parallel, we isolated clones resistant to HA/C activity from a susceptible mouse fibroblast strain. These cells lacked expression of ST-I, the enzyme that transfers sialic acid to lactosylceramide to yield GM3. These clones became sensitive to HA/C activity when GM3 was expressed by transfection with the ST-I gene. The sensitivity of fibroblasts to HA/C was reduced by expressing ganglioside synthesis genes whose products utilize GM3 as a substrate and consequently generate other a-series gangliosides, suggesting a GM3-specific mechanism. Our results demonstrate that HA/C affects cells in a GM3-dependent manner. PMID:26077172

  20. Acanthamoeba castellanii: cellular changes induced by chlorination.

    PubMed

    Mogoa, Emerancienne; Bodet, Charles; Legube, Bernard; Héchard, Yann

    2010-09-01

    Chlorination is a well-known disinfection method, used in water treatment to inactivate various microorganisms, it induces numerous cellular changes. Even though Acanthamoebae are frequently found in water, the cellular changes induced in Acanthamoebae have not been described in the literature. Acanthamoebae are pathogenic amoebae and may provide a reservoir for pathogenic bacteria such as Legionellapneumophila; it is consequently important to understand the response of this amoeba to chlorination, and our study was indeed aimed at examining cellular changes in Acanthamoebae following chlorination. Acanthamoeba trophozoites were treated at various chlorine concentrations (1-5mg/L). A 3-log reduction in Acanthamoebae population was achieved with 5mg/L of free chlorine. Confocal microscopy and flow cytometry experiments indicated that chlorination induced cell permeabilization, size reduction and likely intracellular thiol concentration. Our data show that among the non-cultivable cells some remained impermeabilized (negative staining with propidium iodide), thereby suggesting that these cells might remained viable. A similar state is described in other microorganisms as a VBNC (viable but not cultivable) state. Electron microscopy observations illustrate drastic morphological changes: the pseudopods disappeared and subcellular components, such as mitochondrion, were pronouncedly affected. In conclusion, depending on the concentration used, chlorination leads to many cellular effects on Acanthamoeba that could well arise in cell inactivation. PMID:20034490

  1. A single early postnatal estradiol injection affects morphology and gene expression of the ovary and parametrial adipose tissue in adult female rats.

    PubMed

    Alexanderson, Camilla; Stener-Victorin, Elisabet; Kullberg, Joel; Nilsson, Staffan; Levin, Max; Cajander, Stefan; Lönn, Lars; Lönn, Malin; Holmäng, Agneta

    2010-10-01

    Events during early life can affect reproductive and metabolic functions in adulthood. We evaluated the programming effects of a single early postnatal estradiol injection (within 3h after birth) in female rats. We assessed ovarian and parametrial adipose tissue morphology, evaluated gene expression related to follicular development and adipose tissue metabolism, and developed a non-invasive volumetric estimation of parametrial adipose tissue by magnetic resonance imaging. Estradiol reduced ovarian weight, increased antral follicle size and number of atretic antral follicles, and decreased theca interna thickness in atretic antral follicles. Adult estradiol-injected rats also had malformed vaginal openings and lacked corpora lutea, confirming anovulation. Estradiol markedly reduced parametrial adipose tissue mass. Adipocyte size was unchanged, suggesting reduced adipocyte number. Parametrial adipose tissue lipoprotein lipase activity was increased. In ovaries, estradiol increased mRNA expression of adiponectin, complement component 3, estrogen receptor α, and glucose transporter 3 and 4; in parametrial adipose tissue, expression of complement component 3 was increased, expression of estrogen receptor α was decreased, and expression of leptin, lipoprotein lipase, and hormone-sensitive lipase was unaffected. These findings suggest that early postnatal estradiol exposure of female rats result in long-lasting effects on the ovary and parametrial adipose tissue at adult age. PMID:19857573

  2. The affect of low-coherent light on microbial colony forming ability and morphology of some gram-positive and gram-negative bacteria

    NASA Astrophysics Data System (ADS)

    Popov, Denis E.; Tuchina, Elena S.; Chernova, Julia A.; Podshibyakin, Dmitry; Rudik, Dmitry V.; Samsonova, Maria; Gromov, Igor; Tuchin, Valery V.

    2005-06-01

    Gram-negative E. coli, gram-positive facultative anaerobe cocci Staphylococcus lugdensis, Micrococcus halobius, and Stomatococcus mucilaginosus as subjects of study were chosen. LEDs with spectrum maxima at 405 nm (without any exogenous sensitizer) and 660 nm (in conjunction with methylene blue) and power densities of 23 mW/cm2 and 5.7 mW/cm2 accordingly as continuous light sources were chosen. Photosensitized light's affect by methylene blue was studied on E. coli only. The original scheme of experiment set up was developed. It permits one to increase expositions quantity in each experiment for more certain trend's construction over dose curves and decrease parasite flora sowing. As a result of accomplished studies it was established that blue low-coherent light have unalike weak light's dose depending suppressing effect on cocci whereas red low-coherent light have a moderate dose-depended suppressing effect at low irradiation doses and a moderate dose-depended stimulating effect at high irradiation doses on sensitized by MeBlue E. coli. For all ofthis, but Staphylococcus morphology changes were observed.

  3. Genetic Dominance & Cellular Processes

    ERIC Educational Resources Information Center

    Seager, Robert D.

    2014-01-01

    In learning genetics, many students misunderstand and misinterpret what "dominance" means. Understanding is easier if students realize that dominance is not a mechanism, but rather a consequence of underlying cellular processes. For example, metabolic pathways are often little affected by changes in enzyme concentration. This means that…

  4. mGluR5 Positive and Negative Allosteric Modulators Differentially Affect Dendritic Spine Density and Morphology in the Prefrontal Cortex

    PubMed Central

    LaCrosse, Amber L.; Taylor, Sara B.; Nemirovsky, Natali E.; Gass, Justin T.; Olive, M. Foster

    2015-01-01

    Positive and negative allosteric modulators (PAMs and NAMs, respectively) of type 5 metabotropic glutamate receptors (mGluR5) are currently being investigated as novel treatments for neuropsychiatric diseases including drug addiction, schizophrenia, and Fragile X syndrome. However, only a handful of studies have examined the effects of mGluR5 PAMs or NAMs on the structural plasticity of dendritic spines in otherwise naïve animals, particularly in brain regions mediating executive function. In the present study, we assessed dendritic spine density and morphology in pyramidal cells of the medial prefrontal cortex (mPFC) after repeated administration of either the prototypical mGluR5 PAM 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB, 20 mg/kg), the clinically utilized mGluR5 NAM 1-(3-chlorophenyl)-3-(3-methyl-5-oxo-4H-imidazol-2-yl)urea (fenobam, 20 mg/kg), or vehicle in male Sprague-Dawley rats. Following once daily treatment for 10 consecutive days, coronal brain sections containing the mPFC underwent diolistic labeling and 3D image analysis of dendritic spines. Compared to vehicle treated animals, rats administered fenobam exhibited significant increases in dendritic spine density and the overall frequency of spines with small (<0.2 μm) head diameters, decreases in frequency of spines with medium (0.2–0.4 μm) head diameters, and had no changes in frequency of spines with large head diameters (>0.4 μm). Administration of CDPPB had no discernable effects on dendritic spine density or morphology, and neither CDPPB nor fenobam had any effect on spine length or volume. We conclude that mGluR5 PAMs and NAMs differentially affect mPFC dendritic spine structural plasticity in otherwise naïve animals, and additional studies assessing their effects in combination with cognitive or behavioral tasks are needed. PMID:25921744

  5. Morphological adaptation of rumen papillae during the dry period and early lactation as affected by rate of increase of concentrate allowance.

    PubMed

    Dieho, K; Bannink, A; Geurts, I A L; Schonewille, J T; Gort, G; Dijkstra, J

    2016-03-01

    . Microscopic morphology was affected by sampling day, but neither by concentrate treatment nor by their interaction, with a decrease in papilla and epithelium thickness during the lactation. In conclusion, the rumen papillae respond to changes in FOM intake and the magnitude of this response depends on the rate of increase of FOM intake. This response in surface area of the rumen papillae potentially facilitates the absorption of the volatile fatty acids. PMID:26805997

  6. Demonstration by real-time polymerase chain reaction that cellular DNA alkylation by novel aminoindoline compounds affects expression of the protooncogene c-myc.

    PubMed

    Nelson, Stephanie M; Ferguson, Lynnette R; Denny, William A

    2005-02-01

    Aminoindolines, analogues of the potent DNA alkylating agent seco-CBI-TMI, bind to and alkylate in the minor groove of AT-rich DNA in vitro. Here we extend the in vitro mechanism of action studies by treating cells in culture and examining the DNA binding patterns within AT-rich regions of the protooncogene locus c-myc, using a real-time polymerase chain reaction (PCR) stop assay. In addition, real-time reverse transcriptase (RT) PCR is used to examine the immediate effects of drug treatment on c-myc expression. These analyses demonstrate a concentration and time dependence for DNA alkylation at the chosen sites within the c-myc locus, as well as a prompt and significant downregulation of c-myc expression. While downregulation of this important growth regulator is likely not the only consequence of aminoindoline treatment, these studies begin to address the cellular pathways that are involved in the potent cytotoxic effects observed and provide insights for the future development of anticancer drugs of this class. PMID:15720128

  7. An Evolutionary Hybrid Cellular Automaton Model of Solid Tumour Growth

    PubMed Central

    Gerlee, P.; Anderson, A.R.A.

    2007-01-01

    We propose a cellular automaton model of solid tumour growth, in which each cell is equipped with a micro-environment response network. This network is modelled using a feed-forward artificial neural network, that takes environmental variables as an input and from these determines the cellular behaviour as the output. The response of the network is determined by connection weights and thresholds in the network, which are subject to mutations when the cells divide. As both available space and nutrients are limited resources for the tumour this gives rise to clonal evolution where only the fittest cells survive. Using this approach we have investigated the impact of the tissue oxygen concentration on the growth and evolutionary dynamics of the tumour. The results show that the oxygen concentration affects the selection pressure, cell population diversity and morphology of the tumour. A low oxygen concentration in the tissue gives rise to a tumour with a fingered morphology that contains aggressive phenotypes with a small apoptotic potential, while a high oxygen concentration in the tissue gives rise to a tumour with a round morphology containing less evolved phenotypes. The tissue oxygen concentration thus affects the tumour at both the morphological level and on the phenotype level. PMID:17374383

  8. Phase measurements of erythrocytes affected by metal ions with quantitative interferometric microscopy

    NASA Astrophysics Data System (ADS)

    Wang, Shouyu; Yan, Keding; Shan, Yanke; Xu, Mingfei; Liu, Fei; Xue, Liang

    2015-12-01

    Erythrocyte morphology is an important factor in disease diagnosis, however, traditional setups as microscopes and cytometers cannot provide enough quantitative information of cellular morphology for in-depth statistics and analysis. In order to capture variations of erythrocytes affected by metal ions, quantitative interferometric microscopy (QIM) is applied to monitor their morphology changes. Combined with phase retrieval and cell recognition, erythrocyte phase images, as well as phase area and volume, can be accurately and automatically obtained. The research proves that QIM is an effective tool in cellular observation and measurement.

  9. Carbon nanotubes affect the toxicity of CuO nanoparticles to denitrification in marine sediments by altering cellular internalization of nanoparticle

    NASA Astrophysics Data System (ADS)

    Zheng, Xiong; Su, Yinglong; Chen, Yinguang; Wan, Rui; Li, Mu; Huang, Haining; Li, Xu

    2016-06-01

    Denitrification is an important pathway for nitrate transformation in marine sediments, and this process has been observed to be negatively affected by engineered nanomaterials. However, previous studies only focused on the potential effect of a certain type of nanomaterial on microbial denitrification. Here we show that the toxicity of CuO nanoparticles (NPs) to denitrification in marine sediments is highly affected by the presence of carbon nanotubes (CNTs). It was found that the removal efficiency of total NOX‑-N (NO3‑-N and NO2‑-N) in the presence of CuO NPs was only 62.3%, but it increased to 81.1% when CNTs appeared in this circumstance. Our data revealed that CuO NPs were more easily attached to CNTs rather than cell surface because of the lower energy barrier (3.5 versus 36.2 kT). Further studies confirmed that the presence of CNTs caused the formation of large, incompact, non-uniform dispersed, and more negatively charged CuO-CNTs heteroaggregates, and thus reduced the nanoparticle internalization by cells, leading to less toxicity to metabolism of carbon source, generation of reduction equivalent, and activities of nitrate reductase and nitrite reductase. These results indicate that assessing nanomaterial-induced risks in real circumstances needs to consider the “mixed” effects of nanomaterials.

  10. Carbon nanotubes affect the toxicity of CuO nanoparticles to denitrification in marine sediments by altering cellular internalization of nanoparticle.

    PubMed

    Zheng, Xiong; Su, Yinglong; Chen, Yinguang; Wan, Rui; Li, Mu; Huang, Haining; Li, Xu

    2016-01-01

    Denitrification is an important pathway for nitrate transformation in marine sediments, and this process has been observed to be negatively affected by engineered nanomaterials. However, previous studies only focused on the potential effect of a certain type of nanomaterial on microbial denitrification. Here we show that the toxicity of CuO nanoparticles (NPs) to denitrification in marine sediments is highly affected by the presence of carbon nanotubes (CNTs). It was found that the removal efficiency of total NOX(-)-N (NO3(-)-N and NO2(-)-N) in the presence of CuO NPs was only 62.3%, but it increased to 81.1% when CNTs appeared in this circumstance. Our data revealed that CuO NPs were more easily attached to CNTs rather than cell surface because of the lower energy barrier (3.5 versus 36.2 kT). Further studies confirmed that the presence of CNTs caused the formation of large, incompact, non-uniform dispersed, and more negatively charged CuO-CNTs heteroaggregates, and thus reduced the nanoparticle internalization by cells, leading to less toxicity to metabolism of carbon source, generation of reduction equivalent, and activities of nitrate reductase and nitrite reductase. These results indicate that assessing nanomaterial-induced risks in real circumstances needs to consider the "mixed" effects of nanomaterials. PMID:27279546

  11. Carbon nanotubes affect the toxicity of CuO nanoparticles to denitrification in marine sediments by altering cellular internalization of nanoparticle

    PubMed Central

    Zheng, Xiong; Su, Yinglong; Chen, Yinguang; Wan, Rui; Li, Mu; Huang, Haining; Li, Xu

    2016-01-01

    Denitrification is an important pathway for nitrate transformation in marine sediments, and this process has been observed to be negatively affected by engineered nanomaterials. However, previous studies only focused on the potential effect of a certain type of nanomaterial on microbial denitrification. Here we show that the toxicity of CuO nanoparticles (NPs) to denitrification in marine sediments is highly affected by the presence of carbon nanotubes (CNTs). It was found that the removal efficiency of total NOX−-N (NO3−-N and NO2−-N) in the presence of CuO NPs was only 62.3%, but it increased to 81.1% when CNTs appeared in this circumstance. Our data revealed that CuO NPs were more easily attached to CNTs rather than cell surface because of the lower energy barrier (3.5 versus 36.2 kT). Further studies confirmed that the presence of CNTs caused the formation of large, incompact, non-uniform dispersed, and more negatively charged CuO-CNTs heteroaggregates, and thus reduced the nanoparticle internalization by cells, leading to less toxicity to metabolism of carbon source, generation of reduction equivalent, and activities of nitrate reductase and nitrite reductase. These results indicate that assessing nanomaterial-induced risks in real circumstances needs to consider the “mixed” effects of nanomaterials. PMID:27279546

  12. Formin’ cellular structures

    PubMed Central

    Bogdan, Sven; Schultz, Jörg; Grosshans, Jörg

    2014-01-01

    Members of the Diaphanous (Dia) protein family are key regulators of fundamental actin driven cellular processes, which are conserved from yeast to humans. Researchers have uncovered diverse physiological roles in cell morphology, cell motility, cell polarity, and cell division, which are involved in shaping cells into tissues and organs. The identification of numerous binding partners led to substantial progress in our understanding of the differential functions of Dia proteins. Genetic approaches and new microscopy techniques allow important new insights into their localization, activity, and molecular principles of regulation. PMID:24719676

  13. Egg storage duration and hatch window affect gene expression of nutrient transporters and intestine morphological parameters of early hatched broiler chicks.

    PubMed

    Yalcin, S; Gursel, I; Bilgen, G; Izzetoglu, G T; Horuluoglu, B H; Gucluer, G

    2016-05-01

    In recent years, researchers have given emphasis on the differences in physiological parameters between early and late hatched chicks within a hatch window. Considering the importance of intestine development in newly hatched chicks, however, changes in gene expression of nutrient transporters in the jejunum of early hatched chicks within a hatch window have not been studied yet. This study was conducted to determine the effects of egg storage duration before incubation and hatch window on intestinal development and expression of PepT1 (H+-dependent peptide transporter) and SGLT1 (sodium-glucose co-transporter) genes in the jejunum of early hatched broiler chicks within a 30 h of hatch window. A total of 1218 eggs obtained from 38-week-old Ross 308 broiler breeder flocks were stored for 3 (ES3) or 14 days (ES14) and incubated at the same conditions. Eggs were checked between 475 and 480 h of incubation and 40 chicks from each egg storage duration were weighed; chick length and rectal temperature were measured. The chicks were sampled to evaluate morphological parameters and PepT1 and SGLT1 expression. The remaining chicks that hatched between 475 and 480 h were placed back in the incubator and the same measurements were conducted with those chicks at the end of hatch window at 510 h of incubation. Chick length, chick dry matter content, rectal temperature and weight of small intestine segments increased, whereas chick weight decreased during the hatch window. The increase in the jejunum length and villus width and area during the hatch window were higher for ES3 than ES14 chicks. PepT1 expression was higher for ES3 chicks compared with ES14. There was a 10.2 and 17.6-fold increase in PepT1 and SGLT1 expression of ES3 chicks at the end of hatch window, whereas it was only 2.3 and 3.3-fold, respectively, for ES14 chicks. These results suggested that egg storage duration affected development of early hatched chicks during 30 h of hatch window. It can be concluded that

  14. The effect of controlled floods on decadal-scale changes in channel morphology and fine sediment storage in a debris-fan affected river canyon

    NASA Astrophysics Data System (ADS)

    Mueller, E. R.; Grams, P. E.; Schmidt, J. C.

    2013-12-01

    In 2011, a large magnitude flow release from Flaming Gorge Reservoir resulted in the third highest recorded discharge of the Green River downstream from Flaming Gorge Dam subsequent to its closure in 1963. Following this event, we made measurements of channel geometry, tracer gravel displacement, and sandbar sedimentology at four long-term monitoring reaches within the Canyon of Lodore in Dinosaur National Monument, Colorado. Here we integrate these data with nearly two decades of channel monitoring at these sites, encompassing five controlled floods, and providing a coarse resolution, but coherent, picture of channel response and changes in fine sediment storage in a canyon-bound river. We discuss these results in the context of long-term monitoring of controlled flood response along the Colorado River in Marble and Grand Canyons, Arizona. In Canyon of Lodore, moderate, short-duration controlled floods have had little effect on channel morphology or fine sediment storage. Alternatively, higher magnitude floods approaching the pre-dam mean annual flood, such as in 1999 and 2011, tended to be long duration and scoured fine sediment from the channel bed, in some places up to 5 m, while building eddy sandbars to within a meter of flood stage. This resulted in a net export of sediment from the monitored reaches. Between floods, eddy sand bars erode and the pools fill with fine sediment. We have observed only minor erosion or reworking of gravel bars and channel margin deposits stabilized by vegetation encroachment. The Green River in Canyon of Lodore is a scaled-down version of the Colorado River in debris fan-affected Marble and Grand Canyons. Both rivers now exist in varying degrees of sediment deficit due to upstream reservoirs. Coarse sediment from debris fans and hillslopes limits vertical incision and channel migration, focusing the post-dam geomorphic response to sediment imbalance on fine sediment located in eddy sandbars, pools, and channel margin deposits. In

  15. How do the physicochemical properties of nanoliposomes affect their interactions with the hCMEC/D3 cellular model of the BBB?

    PubMed

    Papadia, Konstantina; Markoutsa, Eleni; Antimisiaris, Sophia G

    2016-07-25

    Nanosized liposomes composed of 1,2-distearoyl-sn-glycerol-3-phosphatidylcholine (DSPC), cholesterol and polyethylene glycol-conjugated phospholipid (PEG), incorporating FITC-dextran (FITC) and in some cases also Rhodamine-conjugated phospholipid (RHO) (as labels) were constructed by the thin film hydration method, followed by extrusion; membranes with pore diameters from 50 to 400nm were used, while charged vesicles were produced by partially replacing DSPC with 1,2-distearoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DSPG). The uptake of liposomes by hCMED/D3 cells was evaluated by measuring FITC in cells, and their permeability across cell monolayers was evaluated, by measuring the FI of liposome associated-FITC and RHO in the receiving side of a monolayer-transwell system. Results prove that liposome size has a significant effect on their uptake and permeability (for both charged and non-charged vesicles). The effect of liposome charge on cell uptake was slight (but significant), however charge (in the range from -2 to -16mV) did not significantly affect vesicle permeability; a significant decrease was only demonstrated for the liposome with the highest charge. PMID:27286634

  16. The yield and quality of cellular and bacterial DNA extracts from human oral rinse samples are variably affected by the cell lysis methodology.

    PubMed

    Sohrabi, Mohsen; Nair, Raj G; Samaranayake, Lakshman P; Zhang, Li; Zulfiker, Abu Hasanat Md; Ahmetagic, Adnan; Good, David; Wei, Ming Q

    2016-03-01

    Recent culture-independent studies have enabled detailed mapping of human microbiome that has not been hitherto achievable by culture-based methods. DNA extraction is a key element of bacterial culture-independent studies that critically impacts on the outcome of the detected microbial profile. Despite the variations in DNA extraction methods described in the literature, no standardized technique is available for the purpose of microbiome profiling. Hence, standardization of DNA extraction methods is urgently needed to yield comparable data from different studies. We examined the effect of eight different cell lysis protocols on the yield and quality of the extracted DNA from oral rinse samples. These samples were exposed to cell lysis techniques based on enzymatic, mechanical, and a combination of enzymatic-mechanical methods. The outcome measures evaluated were total bacterial population, Firmicutes levels and human DNA contamination (in terms of surrogate GAPDH levels). We noted that all three parameters were significantly affected by the method of cell lysis employed. Although the highest yield of gDNA was obtained using lysozyme-achromopeptidase method, the lysozyme-zirconium beads method yielded the peak quantity of total bacterial DNA and Firmicutes with a lower degree of GAPDH contamination compared with the other methods. Taken together our data clearly points to an urgent need for a consensus, standardized DNA extraction technique to evaluate the oral microbiome using oral rinse samples. Further, if Firmicutes levels are the focus of investigation in oral rinse microbiome analyses then the lysozyme-zirconium bead method would be the method of choice in preference to others. PMID:26812577

  17. Perturbations of Amino Acid Metabolism Associated with Glyphosate-Dependent Inhibition of Shikimic Acid Metabolism Affect Cellular Redox Homeostasis and Alter the Abundance of Proteins Involved in Photosynthesis and Photorespiration1[W][OA

    PubMed Central

    Vivancos, Pedro Diaz; Driscoll, Simon P.; Bulman, Christopher A.; Ying, Liu; Emami, Kaveh; Treumann, Achim; Mauve, Caroline; Noctor, Graham; Foyer, Christine H.

    2011-01-01

    The herbicide glyphosate inhibits the shikimate pathway of the synthesis of amino acids such as phenylalanine, tyrosine, and tryptophan. However, much uncertainty remains concerning precisely how glyphosate kills plants or affects cellular redox homeostasis and related processes in glyphosate-sensitive and glyphosate-resistant crop plants. To address this issue, we performed an integrated study of photosynthesis, leaf proteomes, amino acid profiles, and redox profiles in the glyphosate-sensitive soybean (Glycine max) genotype PAN809 and glyphosate-resistant Roundup Ready Soybean (RRS). RRS leaves accumulated much more glyphosate than the sensitive line but showed relatively few changes in amino acid metabolism. Photosynthesis was unaffected by glyphosate in RRS leaves, but decreased abundance of photosynthesis/photorespiratory pathway proteins was observed together with oxidation of major redox pools. While treatment of a sensitive genotype with glyphosate rapidly inhibited photosynthesis and triggered the appearance of a nitrogen-rich amino acid profile, there was no evidence of oxidation of the redox pools. There was, however, an increase in starvation-associated and defense proteins. We conclude that glyphosate-dependent inhibition of soybean leaf metabolism leads to the induction of defense proteins without sustained oxidation. Conversely, the accumulation of high levels of glyphosate in RRS enhances cellular oxidation, possibly through mechanisms involving stimulation of the photorespiratory pathway. PMID:21757634

  18. Cellular resilience.

    PubMed

    Smirnova, Lena; Harris, Georgina; Leist, Marcel; Hartung, Thomas

    2015-01-01

    Cellular resilience describes the ability of a cell to cope with environmental changes such as toxicant exposure. If cellular metabolism does not collapse directly after the hit or end in programmed cell death, the ensuing stress responses promote a new homeostasis under stress. The processes of reverting "back to normal" and reversal of apoptosis ("anastasis") have been studied little at the cellular level. Cell types show astonishingly similar vulnerability to most toxicants, except for those that require a very specific target, metabolism or mechanism present only in specific cell types. The majority of chemicals triggers "general cytotoxicity" in any cell at similar concentrations. We hypothesize that cells differ less in their vulnerability to a given toxicant than in their resilience (coping with the "hit"). In many cases, cells do not return to the naive state after a toxic insult. The phenomena of "pre-conditioning", "tolerance" and "hormesis" describe this for low-dose exposures to toxicants that render the cell more resistant to subsequent hits. The defense and resilience programs include epigenetic changes that leave a "memory/scar" - an alteration as a consequence of the stress the cell has experienced. These memories might have long-term consequences, both positive (resistance) and negative, that contribute to chronic and delayed manifestations of hazard and, ultimately, disease. This article calls for more systematic analyses of how cells cope with toxic perturbations in the long-term after stressor withdrawal. A technical prerequisite for these are stable (organotypic) cultures and a characterization of stress response molecular networks. PMID:26536287

  19. Twenty Four-Hour Exposure to a 0.12 THz Electromagnetic Field Does Not Affect the Genotoxicity, Morphological Changes, or Expression of Heat Shock Protein in HCE-T Cells.

    PubMed

    Koyama, Shin; Narita, Eijiro; Shimizu, Yoko; Shiina, Takeo; Taki, Masao; Shinohara, Naoki; Miyakoshi, Junji

    2016-01-01

    To investigate the cellular effects of terahertz (THz) exposure, human corneal epithelial (HCE-T) cells derived from human eye were exposed to 0.12 THz radiation at 5 mW/cm² for 24 h, then the genotoxicity, morphological changes, and heat shock protein (Hsp) expression of the cells were examined. There was no statistically significant increase in the micronucleus (MN) frequency of cells exposed to 0.12 THz radiation compared with sham-exposed controls and incubator controls, whereas the MN frequency of cells treated with bleomycin for 1 h (positive control) did increase significantly. Similarly, there were no significant morphological changes in cells exposed to 0.12 THz radiation compared to sham-exposed controls and incubator controls, and Hsp expression (Hsp27, Hsp70, and Hsp90α) was also not significantly different between the three treatments. These results indicate that exposure to 0.12 THz radiation using the present conditions appears to have no or very little effect on MN formation, morphological changes, and Hsp expression in cells derived from human eye. PMID:27527204

  20. Twenty Four-Hour Exposure to a 0.12 THz Electromagnetic Field Does Not Affect the Genotoxicity, Morphological Changes, or Expression of Heat Shock Protein in HCE-T Cells

    PubMed Central

    Koyama, Shin; Narita, Eijiro; Shimizu, Yoko; Shiina, Takeo; Taki, Masao; Shinohara, Naoki; Miyakoshi, Junji

    2016-01-01

    To investigate the cellular effects of terahertz (THz) exposure, human corneal epithelial (HCE-T) cells derived from human eye were exposed to 0.12 THz radiation at 5 mW/cm2 for 24 h, then the genotoxicity, morphological changes, and heat shock protein (Hsp) expression of the cells were examined. There was no statistically significant increase in the micronucleus (MN) frequency of cells exposed to 0.12 THz radiation compared with sham-exposed controls and incubator controls, whereas the MN frequency of cells treated with bleomycin for 1 h (positive control) did increase significantly. Similarly, there were no significant morphological changes in cells exposed to 0.12 THz radiation compared to sham-exposed controls and incubator controls, and Hsp expression (Hsp27, Hsp70, and Hsp90α) was also not significantly different between the three treatments. These results indicate that exposure to 0.12 THz radiation using the present conditions appears to have no or very little effect on MN formation, morphological changes, and Hsp expression in cells derived from human eye. PMID:27527204

  1. Exposure to coal combustion residues during metamorphosis elevates corticosterone content and adversely affects oral morphology, growth, and development in Rana sphenocephala

    SciTech Connect

    Peterson, J.D.; Peterson, V.A.; Mendonca, M.T.

    2009-01-15

    Coal combustion residues (CCRs) are documented to negatively impact oral morphology, growth, and development in larval amphibians. It is currently unclear what physiological mechanisms may mediate these effects. Corticosterone, a glucocorticoid hormone, is a likely mediator because when administered exogenously it, like CCRs, also negatively influences oral morphology, growth, and development in larval amphibians. In an attempt to identify if corticosterone mediates these effects, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate and documented effects of sediment type on whole body corticosterone, oral morphology, and time to and mass at key metamorphic stages. Coal combustion residue treated tadpoles contained significantly more corticosterone than controls throughout metamorphosis. However, significantly more oral abnormalities occurred early in metamorphosis when differences in corticosterone levels between treatments were minimal. Overall, CCR-treated tadpoles took significantly more time to transition between key stages and gained less mass between stages than controls, but these differences between treatments decreased during later stages when corticosterone differences between treatments were greatest. Our results suggest endogenous increase in corticosterone content and its influence on oral morphology, growth and development is more complex than previously thought.

  2. Morphological restriction of human coronary artery endothelial cells substantially impacts global gene expression patterns

    PubMed Central

    Stiles, Jessica M; Pham, Robert; Rowntree, Rebecca K; Amaya, Clarissa; Battiste, James; Boucheron, Laura E; Mitchell, Dianne C; Bryan, Brad A

    2013-01-01

    Alterations in cell shape have been shown to modulate chromatin condensation and cell lineage specification; however, the mechanisms controlling these processes are largely unknown. Because endothelial cells experience cyclic mechanical changes from blood flow during normal physiological processes and disrupted mechanical changes as a result of abnormal blood flow, cell shape deformation and loss of polarization during coronary artery disease, we aimed to determine how morphological restriction affects global gene expression patterns. Human coronary artery endothelial cells (HCAECs) were cultured on spatially defined adhesive micropatterns, forcing them to conform to unique cellular morphologies differing in cellular polarization and angularity. We utilized pattern recognition algorithms and statistical analysis to validate the cytoskeletal pattern reproducibility and uniqueness of each micropattern, and performed microarray analysis on normal-shaped and micropatterned HCAECs to determine how constrained cellular morphology affects gene expression patterns. Analysis of the data revealed that forcing HCAECs to conform to geometrically-defined shapes significantly affects their global transcription patterns compared to nonrestricted shapes. Interestingly, gene expression patterns were altered in response to morphological restriction in general, although they were consistent regardless of the particular shape the cells conformed to. These data suggest that the ability of HCAECs to spread, although not necessarily their particular morphology, dictates their genomics patterns. PMID:23802622

  3. Virus-induced gene silencing of PEAM4 affects floral morphology by altering the expression pattern of PsSOC1a and PsPVP in pea.

    PubMed

    Chen, Zhe-Hao; Jia, Fei-Fei; Hu, Jiang-Qin; Pang, Ji-Liang; Xu, Lei; Wang, Li-Lin

    2014-01-15

    pea-MADS4 (PEAM4) regulates floral morphology in Pisum sativum L., however, its molecular mechanisms still remain unclear. Virus-induced gene silencing (VIGS) is a recently developed reverse genetic approach that facilities an easier and more rapid study of gene functions. In this study, the PEAM4 gene was effectively silenced by VIGS using a pea early browning virus (PEBV) in wild type pea JI992. The infected plants showed abnormal phenotypes, as the floral organs, especially the sepals and petals changed in both size and shape, which made the corolla less closed. The petals changed in morphology and internal symmetry with, the stamens reduced and carpel dehisced. Larger sepals and longer tendrils with small cauline leaves appeared, with some sepals turning into bracts, and secondary inflorescences with fused floral organs were formed, indicating a flower-to-inflorescence change. The infected plants also displayed a delayed and prolonged flowering time. The PEAM4-VIGS plants with altered floral morphology were similar to the pim (proliferating inflorescence meristem) mutant and also mimicked the phenotypes of ap1 mutants in Arabidopsis. The expression pattern of the homologous genes PsSOC1a and PsSVP, which were involved in flowering time and florescence morphological control downstream of PEAM4, were analyzed by real-time RT-PCR and mRNA in situ hybridization. PsSOC1a and PsSVP were ectopically expressed and enhanced in the floral meristems from PEAM4-silenced plants. Our data suggests that PEAM4 may have a similar molecular mechanism as AtAP1, which inhibits the expression of PsSOC1a and PsSVP in the floral meristem from the early stages of flower development. As such, in this way PEAM4 plays a crucial role in maintaining floral organ identity and flower development in pea. PMID:24331430

  4. Multianalyte Microphysiometry Reveals Changes in Cellular Bioenergetics Upon Exposure to Fluorescent Dyes

    PubMed Central

    Shinawi, Tesniem F.; Kimmel, Danielle W.; Cliffel, David E.

    2014-01-01

    Fluorescent dyes have been designed for internal cellular component specificity, and have been used extensively in the scientific community as a means to monitor cell growth, location, morphology, and viability. However, it is possible that the introduction of these dyes influences the basal function of the cell and, in turn, the results of these studies. Electrochemistry provides a non-invasive method for probing the unintended cellular affects of these dyes. The multianalyte microphysiometer (MAMP) is capable of simultaneous electrochemical measurement of extracellular metabolites in real-time. In this study, analytes central to cellular metabolism, glucose, lactate, oxygen, as well as extracellular acidification were monitored to determine the immediate metabolic effects of nuclear stains, including SYTO®, DAPI dilactate, Hoechst 33342, and FITC dyes upon the pheochromocytoma PC-12 cells and RAW 264.7 macrophages. The experimental results revealed that SYTO dye 13 significantly decreased glucose and oxygen consumption and increased extracellular acidification and lactate production in both cell lines, indicating a shift to anaerobic respiration. No other dyes caused significantly definitive changes in cellular metabolism upon exposure. This study shows that fluorescent dyes can have unintended effects on cellular metabolism and care should be taken when using these probes to investigate cellular function and morphology. PMID:24228839

  5. Comparison of the morphology of alkali–silica gel formed in limestones in concrete affected by the so-called alkali–carbonate reaction (ACR) and alkali–silica reaction (ASR)

    SciTech Connect

    Grattan-Bellew, P.E.; Chan, Gordon

    2013-05-15

    The morphology of alkali–silica gel formed in dolomitic limestone affected by the so-called alkali–carbonate reaction (ACR) is compared to that formed in a siliceous limestone affected by alkali–silica reaction (ASR). The particle of dolomitic limestone was extracted from the experimental sidewalk in Kingston, Ontario, Canada that was badly cracked due to ACR. The siliceous limestone particle was extracted from a core taken from a highway structure in Quebec, affected by ASR. Both cores exhibited marked reaction rims around limestone particles. The aggregate particles were polished and given a light gold coating in preparation for examination in a scanning electron microscope. The gel in the ACR aggregate formed stringers between the calcite crystals in the matrix of the rock, whereas gel in ASR concrete formed a thick layer on top of the calcite crystals, that are of the same size as in the ACR aggregate.

  6. How language affects children's use of derivational morphology in visual word and pseudoword processing: evidence from a cross-language study

    PubMed Central

    Casalis, Séverine; Quémart, Pauline; Duncan, Lynne G.

    2015-01-01

    Developing readers have been shown to rely on morphemes in visual word recognition across several naming, lexical decision and priming experiments. However, the impact of morphology in reading is not consistent across studies with differing results emerging not only between but also within writing systems. Here, we report a cross-language experiment involving the English and French languages, which aims to compare directly the impact of morphology in word recognition in the two languages. Monolingual French-speaking and English-speaking children matched for grade level (Part 1) and for age (Part 2) participated in the study. Two lexical decision tasks (one in French, one in English) featured words and pseudowords with exactly the same structure in each language. The presence of a root (R+) and a suffix ending (S+) was manipulated orthogonally, leading to four possible combinations in words (R+S+: e.g., postal; R+S−: e.g., turnip; R−S+: e.g., rascal; and R-S-: e.g., bishop) and in pseudowords (R+S+: e.g., pondal; R+S−: e.g., curlip; R−S+: e.g., vosnal; and R−S−: e.g., hethop). Results indicate that the presence of morphemes facilitates children's recognition of words and impedes their ability to reject pseudowords in both languages. Nevertheless, effects extend across accuracy and latencies in French but are restricted to accuracy in English, suggesting a higher degree of morphological processing efficiency in French. We argue that the inconsistencies found between languages emphasize the need for developmental models of word recognition to integrate a morpheme level whose elaboration is tuned by the productivity and transparency of the derivational system. PMID:25932018

  7. Foveal Morphology Affects Self-Perceived Visual Function and Treatment Response in Neovascular Age-Related Macular Degeneration: A Cohort Study

    PubMed Central

    Subhi, Yousif; Henningsen, Gitte Ø.; Larsen, Charlotte T.; Sørensen, Mette S.; Sørensen, Torben L.

    2014-01-01

    Objectives To investigate the relationship between foveal morphology and self-perceived visual function in patients with neovascular age-related macular degeneration (AMD) and whether foveal characteristics are associated with Ranibizumab treatment response on the self-perceived visual function. Methods This prospective cohort study included patients with newly diagnosed neovascular AMD found eligible for treatment with Ranibizumab. Foveal morphology of both eyes was assessed using spectral-domain optical coherence tomography and all patients were interviewed using the 39-item National Eye Institute Visual Function Questionnaire (VFQ). Patients were re-interviewed 3 and 12 months after initiation of treatment with Ranibizumab. We evaluated foveal morphology at baseline in relation to VFQ scores at baseline and clinically meaningful changes in VFQ after 3 and 12 months. Results VFQ scores correlated with central foveal thickness, central foveal thickness of neuroretina (CFN), foveal RPE elevation, foveal integrity of the photoreceptor inner segment/outer segment junction (IS/OS), and external limiting membrane. In a multiple linear regression model, only best-corrected visual acuity of the better eye (p<0.001) and the IS/OS status in the better eye (p = 0.012) remained significant (Adjusted R2 = 0.418). Lower baseline VFQ and a baseline CFN within 170–270 µm in the better eye were both associated with a clinically meaningful increase in the VFQ scores after 3 and 12 months. An absent foveal IS/OS band in the better eye was associated with a clinically meaningful decrease in the VFQ scores at 12 months. Conclusions Foveal morphology in the better eye influences the self-perceived visual function in patients with neovascular AMD and possesses a predictive value for change in the self-perceived visual function at 3 and 12 months after initiation of treatment. These findings may help clinicians provide patients more individualized information of their disease

  8. Markers of cellular senescence. Telomere shortening as a marker of cellular senescence

    PubMed Central

    2016-01-01

    The cellular senescence definition comes to the fact of cells irreversible proliferation disability. Besides the cell cycle arrest, senescent cells go through some morphological, biochemical, and functional changes which are the signs of cellular senescence. The senescent cells (including replicative senescence and stress-induced premature senescence) of all the tissues look alike. They are metabolically active and possess the set of characteristics in vitro and in vivo, which are known as biomarkers of aging and cellular senescence. Among biomarkers of cellular senescence telomere shortening is a rather elegant frequently used biomarker. Validity of telomere shortening as a marker for cellular senescence is based on theoretical and experimental data. PMID:26805432

  9. Markers of cellular senescence. Telomere shortening as a marker of cellular senescence.

    PubMed

    Bernadotte, Alexandra; Mikhelson, Victor M; Spivak, Irina M

    2016-01-01

    The cellular senescence definition comes to the fact of cells irreversible proliferation disability. Besides the cell cycle arrest, senescent cells go through some morphological, biochemical, and functional changes which are the signs of cellular senescence. The senescent cells (including replicative senescence and stress-induced premature senescence) of all the tissues look alike. They are metabolically active and possess the set of characteristics in vitro and in vivo, which are known as biomarkers of aging and cellular senescence. Among biomarkers of cellular senescence telomere shortening is a rather elegant frequently used biomarker. Validity of telomere shortening as a marker for cellular senescence is based on theoretical and experimental data. PMID:26805432

  10. Cellular Morphogenesis In Silico

    PubMed Central

    Shinbrot, Troy; Chun, Young; Caicedo-Carvajal, Carlos; Foty, Ramsey

    2009-01-01

    Abstract We describe a model that simulates spherical cells of different types that can migrate and interact either attractively or repulsively. We find that both expected morphologies and previously unreported patterns spontaneously self-assemble. Among the newly discovered patterns are a segmented state of alternating discs, and a “shish-kebab” state, in which one cell type forms a ring around a second type. We show that these unique states result from cellular attraction that increases with distance (e.g., as membranes stretch viscoelastically), and would not be seen in traditional, e.g., molecular, potentials that diminish with distance. Most of the states found computationally have been observed in vitro, and it remains to be established what role these self-assembled states may play in in vivo morphogenesis. PMID:19686642

  11. Direct and indirect sonication affect differently the microstructure and the morphology of ZnO nanoparticles: Optical behavior and its antibacterial activity.

    PubMed

    Sharifalhoseini, Zahra; Entezari, Mohammad H; Jalal, Razieh

    2015-11-01

    In the present study, the sono-synthesis of ZnO nanoparticles (NPs) was performed by simple, low-cost, and the environmentally friendly method. The synthesis of zinc oxide as an antibacterial agent was performed by an ultrasonic bath (low intensity) for the indirect sonication and a horn system (high intensity) for the direct sonication. The samples synthesized by these two kinds of sonication were compared with each other. Crystallographic structures and the morphologies of the resultant powders were determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns showed that both ZnO samples were crystallized in their pure phase. The TEM images confirmed that the morphologies of the products were completely different from each other. Based on the obtained analysis, the probable growth mechanisms were proposed for crystallization of both samples. The antibacterial activity of the synthesized species was evaluated by the colony count method against Escherichia coli O157:H7. Moreover, the optical behavior of the samples was studied by UV-vis spectroscopy and the variation of the ZnO band gap was compared. PMID:26186868

  12. Disruption of the pdhB Pyruvate Dehydrogenase Gene Affects Colony Morphology, In Vitro Growth and Cell Invasiveness of Mycoplasma agalactiae

    PubMed Central

    Hegde, Shivanand; Rosengarten, Renate; Chopra-Dewasthaly, Rohini

    2015-01-01

    The utilization of available substrates, the metabolic potential and the growth rates of bacteria can play significant roles in their pathogenicity. This study concentrates on Mycoplasma agalactiae, which causes significant economic losses through its contribution to contagious agalactia in small ruminants by as yet unknown mechanisms. This lack of knowledge is primarily due to its fastidious growth requirements and the scarcity of genetic tools available for its manipulation and analysis. Transposon mutagenesis of M. agalactiae type strain PG2 resulted in several disruptions throughout the genome. A mutant defective in growth in vitro was found to have a transposon insertion in the pdhB gene, which encodes a component of the pyruvate dehydrogenase complex. This growth difference was quite significant during the actively dividing logarithmic phase but a gradual recovery was observed as the cells approached stationary phase. The mutant also exhibited a different and smaller colony morphology compared to the wild type strain PG2. For complementation, pdhAB was cloned downstream of a strong vpma promoter and upstream of a lacZ reporter gene in a newly constructed complementation vector. When transformed with this vector the pdhB mutant recovered its normal growth and colony morphology. Interestingly, the pdhB mutant also had significantly reduced invasiveness in HeLa cells, as revealed by double immunofluorescence staining. This deficiency was recovered in the complemented strain, which had invasiveness comparable to that of PG2. Taken together, these data indicate that pyruvate dehydrogenase might be an important player in infection with and colonization by M. agalactiae. PMID:25799063

  13. Tsunami Affected Farmland Extraction Using Morphological Profiles (MPs) Method by Satellite Images Including SAR and Visible Near-Infrared Band Data

    NASA Astrophysics Data System (ADS)

    Yamada, Y.

    2015-04-01

    The agricultural fields along the coast were submerged under the sea water after the 2011 off the Pacific Coast of Tohoku Japan Tsunami. The conventional method of detecting Tsunami reached area by SAR satellite data is to compare the data obtained between previous to and after the Tsunami. However such kind of SAR data should be prepared prior to the natural disaster, but in many disaster cases, people have often encountered difficulties in finding such kind of data observed in advance in some regions. Therefore it is desirable to find a way to detect the flood suffering farmlands caused by a Tsunami, using only data observed after the disaster event. The morphological profiles (MPs) method are tested using ALOS/PALSAR and AVNIR-2 data. This MPs method is proposed as the tool for extracting information about the size, shape and the orientation of structures in single-band remote sensing images and has been improved to establish the extended morphological profiles(EMP) dealing with full-spectral information in the multi-/hyper-spectral data (Benediktsson, J.A. et al.,2003,2005). The author's work is intended to apply this MPs method to combined single polarization SAR data and visual and near-infrared bands data. The results approximately coincide with the farmland regions actually reached by the Tsunami. This MPs method requires only data once obtained soon after a disaster, light computer resources and very short turnaround time. It should be suitable for the detection of Tsunami reached areas or tidal wave reached areas, caused by a Typhoon for example, using satellite data only once obtained after a disaster.

  14. Quantifying morphological features of actin cytoskeletal filaments in plant cells based on mathematical morphology.

    PubMed

    Kimori, Yoshitaka; Hikino, Kazumi; Nishimura, Mikio; Mano, Shoji

    2016-01-21

    By quantifying the morphological properties of biological structures, we can better evaluate complex shapes and detect subtle morphological changes in organisms. In this paper, we propose a shape analysis method based on morphological image processing, and apply it to image analysis of actin cytoskeletal filaments in root hair cells of Arabidopsis thaliana. In plant cells, the actin cytoskeletal filaments have critical roles in various cellular processes such as vesicle trafficking and organelle motility. The dynamics of vesicles and organelles in plant cells depend on actin cytoskeletal filaments, regulating cell division and cell enlargement. To better understand the actin-dependent organelle motility, we attempted to quantify the organization of actin filaments in the root hair cells of the root hair defective 3 (rhd3) mutant. RHD3 is involved in actin organization, and its defect has been reported to affect the dynamics of various vesicles and organelles. We measured three shape features of the actin filaments in wild-type and mutant plants. One feature (thickness) was depicted on a grayscale; the others (describing the complexity of the filament network patterns in two-dimensional space) were depicted as binary features. The morphological phenotypes of the cytoskeletal filaments clearly differed between wild-type and mutant. Subtle variations of filament morphology among the mutants were detected and statistically quantified. PMID:26551157

  15. Diet complexity in early life affects survival in released pheasants by altering foraging efficiency, food choice, handling skills and gut morphology.

    PubMed

    Whiteside, Mark A; Sage, Rufus; Madden, Joah R

    2015-11-01

    Behavioural and physiological deficiencies are major reasons why reintroduction programmes suffer from high mortality when captive animals are used. Mitigation of these deficiencies is essential for successful reintroduction programmes. Our study manipulated early developmental diet to better replicate foraging behaviour in the wild. Over 2 years, we hand-reared 1800 pheasants (Phasianus colchicus), from 1 day old, for 7 weeks under different dietary conditions. In year one, 900 pheasants were divided into three groups and reared with (i) commercial chick crumb, (ii) crumb plus 1% live mealworm or (iii) crumb plus 5% mixed seed and fruit. In year two, a further 900 pheasants were divided into two groups and reared with (i) commercial chick crumb or (ii) crumb plus a combination of 1% mealworm and 5% mixed seed and fruit. In both years, the commercial chick crumb acted as a control treatment, whilst those with live prey and mixed seeds and fruits mimicking a more naturalistic diet. After 7 weeks reared on these diets, pheasants were released into the wild. Postrelease survival was improved with exposure to more naturalistic diets prior to release. We identified four mechanisms to explain this. Pheasants reared with more naturalistic diets (i) foraged for less time and had a higher likelihood of performing vigilance behaviours, (ii) were quicker at handling live prey items, (iii) were less reliant on supplementary feed which could be withdrawn and (iv) developed different gut morphologies. These mechanisms allowed the pheasants to (i) reduce the risk of predation by reducing exposure time whilst foraging and allowing more time to be vigilant; (ii) be better at handling and discriminating natural food items and not be solely reliant on supplementary feed; and (iii) have a better gut system to cope with the natural forage after the cessation of supplementary feeding in the spring. Learning food discrimination, preference and handling skills by the provision of a more

  16. An Analysis of Factors Affecting Genotyping Success from Museum Specimens Reveals an Increase of Genetic and Morphological Variation during a Historical Range Expansion of a European Spider

    PubMed Central

    Krehenwinkel, Henrik; Pekar, Stano

    2015-01-01

    Natural history collections house an enormous amount of plant and animal specimens, which constitute a promising source for molecular analyses. Storage conditions differ among taxa and can have a dramatic effect on the success of DNA work. Here, we analyze the feasibility of DNA extraction from ethanol preserved spiders (Araneae). We tested genotyping success using several hundred specimens of the wasp spider, Argiope bruennichi, deposited in two large German natural history collections. We tested the influence of different factors on the utility of specimens for genotyping. Our results show that not the specimen’s age, but the museum collection is a major predictor of genotyping success. These results indicate that long term storage conditions should be optimized in natural history museums to assure the utility of collections for DNA work. Using historical material, we also traced historical genetic and morphological variation in the course of a poleward range expansion of A. bruennichi by comparing contemporary and historical specimens from a native and an invasive population in Germany. We show that the invasion of A. bruennichi is tightly correlated with an historical increase of genetic and phenotypic variation in the invasive population. PMID:26309219

  17. Natural polyamines and synthetic analogs modify the growth and the morphology of Pyrus communis pollen tubes affecting ROS levels and causing cell death.

    PubMed

    Aloisi, Iris; Cai, Giampiero; Tumiatti, Vincenzo; Minarini, Anna; Del Duca, Stefano

    2015-10-01

    Polyamines (PAs) are small molecules necessary for pollen maturation and tube growth. Their role is often controversial, since they may act as pro-survival factors as well as factors promoting Programmed Cell Death (PCD). The aim of the present work was to evaluate the effect of exogenous PAs on the apical growth of pear (Pyrus communis) pollen tube and to understand if PAs and reactive oxygen species (ROS) are interconnected in the process of tip-growth. In the present study besides natural PAs, also aryl-substituted spermine and methoctramine (Met 6-8-6) analogs were tested. Among the natural PAs, Spm showed strongest effects on tube growth. Spm entered through the pollen tube tip, then diffused in the sub-apical region that underwent drastic morphological changes, showing enlarged tip. Analogs were mostly less efficient than natural PAs but BD23, an asymmetric synthetic PAs bearing a pyridine ring, showed similar effects. These effects were related to the ability of PAs to cause the decrease of ROS level in the apical zone, leading to cell death, counteracted by the caspase-3 inhibitor Ac-DEVD-CHO (DEVD). In conclusions, ROS are essential for pollen germination and a strict correlation between ROS regulation and PA concentration is reported. Moreover, an imbalance between ROS and PAs can be detrimental thereby driving pollen toward cell death. PMID:26398794

  18. An Analysis of Factors Affecting Genotyping Success from Museum Specimens Reveals an Increase of Genetic and Morphological Variation during a Historical Range Expansion of a European Spider.

    PubMed

    Krehenwinkel, Henrik; Pekar, Stano

    2015-01-01

    Natural history collections house an enormous amount of plant and animal specimens, which constitute a promising source for molecular analyses. Storage conditions differ among taxa and can have a dramatic effect on the success of DNA work. Here, we analyze the feasibility of DNA extraction from ethanol preserved spiders (Araneae). We tested genotyping success using several hundred specimens of the wasp spider, Argiope bruennichi, deposited in two large German natural history collections. We tested the influence of different factors on the utility of specimens for genotyping. Our results show that not the specimen's age, but the museum collection is a major predictor of genotyping success. These results indicate that long term storage conditions should be optimized in natural history museums to assure the utility of collections for DNA work. Using historical material, we also traced historical genetic and morphological variation in the course of a poleward range expansion of A. bruennichi by comparing contemporary and historical specimens from a native and an invasive population in Germany. We show that the invasion of A. bruennichi is tightly correlated with an historical increase of genetic and phenotypic variation in the invasive population. PMID:26309219

  19. Inactivation of the ampDE Operon Increases Transcription of algD and Affects Morphology and Encystment of Azotobacter vinelandii

    PubMed Central

    Núñez, Cinthia; Moreno, Soledad; Cárdenas, Luis; Soberón-Chávez, Gloria; Espín, Guadalupe

    2000-01-01

    Transcription of algD, encoding GDP-mannose dehydrogenase, the key enzyme in the alginate biosynthetic pathway, is highly regulated in Azotobacter vinelandii. We describe here the characterization of a Tn5 insertion mutant (AC28) which shows a higher level of expression of an algD::lacZ fusion. AC28 cells were morphologically abnormal and unable to encyst. The cloning and nucleotide sequencing of the Tn5-disrupted locus in AC28 revealed an operon homologous to the Escherichia coli ampDE operon. Tn5 was located within the ampD gene, encoding a cytosolic N-acetyl-anhydromuramyl-l-alanine amidase that participates in the intracellular recycling of peptidoglycan fragments. The ampE gene encodes a transmembrane protein, but the function of the protein is not known. We constructed strains carrying ampD or ampE mutations and one with an ampDE deletion. The strain with a deletion of the ampDE operon showed a phenotype similar to that of mutant AC28. The present work demonstrates that both alginate production and bacterial encystment are greatly influenced by the bacterial ability to recycle its cell wall. PMID:10940024

  20. Metronidazole-induced alterations in murine spermatozoa morphology.

    PubMed

    Mudry, Marta D; Palermo, Ana M; Merani, María S; Carballo, Marta A

    2007-02-01

    The aim of this work was to assess the effect of metronidazole (MTZ) on the stages of the seminiferous epithelial cycle and spermatozoa morphology when the drug is administered in human therapeutic doses to 60-day-old CFW male mice. The frequency of the stages was established by counting spermatocytes in pachytene and spermatids. Abnormalities in the flagellum or the head, lack of maturity and multiple malformations, were considered in the morphological analysis. Murine control strain was compared with MTZ treated group (v.ip 130 mg/kg/bw) both kept in standard captivity conditions. Cellular composition or number of stages in the seminiferous tubules were not altered in MTZ exposed animals, though the number of cells in stages I, V and XII was increased. The sperm cell morphology was severely affected by the treatment with potentially serious consequences on the normal fertilization process. Thus, the MTZ has to be considered as a conceivable thread regarding male fertility. PMID:17184970

  1. Understanding cellular architecture in cancer cells

    NASA Astrophysics Data System (ADS)

    Bianco, Simone; Tang, Chao

    2011-03-01

    Understanding the development of cancer is an important goal for today's science. The morphology of cellular organelles, such as the nucleus, the nucleoli and the mitochondria, which is referred to as cellular architecture or cytoarchitecture, is an important indicator of the state of the cell. In particular, there are striking difference between the cellular architecture of a healthy cell versus a cancer cell. In this work we present a dynamical model for the evolution of organelles morphology in cancer cells. Using a dynamical systems approach, we describe the evolution of a cell on its way to cancer as a trajectory in a multidimensional morphology state. The results provided by this work may increase our insight on the mechanism of tumorigenesis and help build new therapeutic strategies.

  2. Experimental sand burial affects seedling survivorship, morphological traits, and biomass allocation of Ulmus pumila var. sabulosa in the Horqin Sandy Land, China

    NASA Astrophysics Data System (ADS)

    Tang, Jiao; Busso, Carlos Alberto; Jiang, Deming; Musa, Ala; Wu, Dafu; Wang, Yongcui; Miao, Chunping

    2016-07-01

    As a native tree species, Ulmus pumila var. sabulosa (sandy elm) is widely distributed in the Horqin Sandy Land, China. However, seedlings of this species have to withstand various depths of sand burial after emergence because of increasing soil degradation, which is mainly caused by overgrazing, climate change, and wind erosion. An experiment was conducted to evaluate the changes in its survivorship, morphological traits, and biomass allocation when seedlings were buried at different burial depths: unburied controls and seedlings buried vertically up to 33, 67, 100, or 133 % of their initial mean seedling height. The results showed that partial sand burial treatments (i.e., less than 67 % burial) did not reduce seedling survivorship, which still reached 100 %. However, seedling mortality increased when sand burial was equal to or greater than 100 %. In comparison with the control treatment, seedling height and stem diameter increased at least by 6 and 14 % with partial burial, respectively. In the meantime, seedling taproot length, total biomass, and relative mass growth rates were at least enhanced by 10, 15.6, and 27.6 %, respectively, with the partial sand burial treatment. Furthermore, sand burial decreased total leaf area and changed biomass allocation in seedlings, partitioning more biomass to aboveground organs (e.g., leaves) and less to belowground parts (roots). Complete sand burial after seedling emergence inhibited its re-emergence and growth, even leading to death. Our findings indicated that seedlings of sandy elm showed some resistance to partial sand burial and were adapted to sandy environments from an evolutionary perspective. The negative effect of excessive sand burial after seedling emergence might help in understanding failures in recruitments of sparse elm in the study region.

  3. Genetic organization of pha gene locus affects phaC expression, poly(hydroxyalkanoate) composition and granule morphology in Pseudomonas corrugata.

    PubMed

    Solaiman, Daniel K Y; Ashby, Richard D; Licciardello, Grazia; Catara, Vittoria

    2008-02-01

    The complete sequence of the pha locus responsible for the biosynthesis of poly(hydroxyalkanoates) (PHAs) in Pseudomonas corrugata 388 was determined. As with the other known pseudomonad pha gene loci, the one in P. corrugata 388 also consists of phaC1 (1,680 bps; PHA synthase 1), phaZ (858 bp; PHA depolymerase) and phaC2 (1,683 bp; PHA synthase 2) genes. A BLAST search showed that the nucleotide sequences of these genes and the amino-acid sequences of their respective gene products are homologous to those of P. corrugata CFBP5454 and P. mediterranea CFBP5447. A putative intrinsic transcription terminator consisting of a dyad symmetry (24 bp; Delta G = -41.8 kcals) that precedes a stretch of dA residues was located in the phaC1-phaZ intergenic region. P. corrugata mutant-clones XI 32-1 and XI 32-4 were constructed in which this intergenic region was replaced with a selectable kanamycin-resistance gene. These mutant clones when grown on oleic acid for 48 h showed 4.7-to 7.0-fold increases of phaC1 and phaC2 relative expression in comparison to the initial inoculants, whereas the parental strain showed only 1.2- to 1.4-fold increases. Furthermore, in comparison to parental P. corrugata with only a few large PHA inclusion bodies, the mutants grown on oleic acid produce numerous smaller PHA granules that line the periphery of the cells. With glucose as a substrate, XI 32-1 and XI 32-4 clones produce mcl-PHA with a high content (26-31 mol%) of the mono-unsaturated 3-hydroxydodecenoate as a repeat-unit monomer. Our results show for the first time the effects of the phaC1-phaZ intergenic region on the substrate-dependent temporal expression of phaC1 and phaC2 genes, the repeat-unit composition of mcl-PHA, and the morphology of the PHA granules. PMID:17987331

  4. USP6 genetic rearrangements in cellular fibroma of tendon sheath.

    PubMed

    Carter, Jodi M; Wang, Xiaoke; Dong, Jie; Westendorf, Jennifer; Chou, Margaret M; Oliveira, Andre M

    2016-08-01

    Fibroma of tendon sheath is a benign (myo)fibroblastic neoplasm of the tenosynovial soft tissues, typically affecting the distal extremities. It is classically described as a paucicellular, densely collagenized tumor; however, cellular variants have been described. A subset of cellular fibromas of tendon sheath shares similar histological features with nodular fasciitis. As nodular fasciitis very frequently harbors rearrangement of ubiquitin-specific peptidase 6 (USP6), we hypothesized that cellular fibromas of tendon sheath with nodular fasciitis-like features may also contain USP6 rearrangements. Cases of fibroma of tendon sheath (n=19), including cellular (n=9) and classic (n=10) variants, were evaluated for USP6 rearrangement by fluorescence in situ hybridization studies. A subset of cases was tested for MYH9 rearrangements and MYH9-USP6 and CDH11-USP6 fusion products. Classic fibroma of tendon sheath occurred in 5 males and 5 females (median age 67 years, range 23-77 years) as soft tissue masses of the hand (n=4), finger (n=3), forearm (n=1) and foot (n=2). Cellular fibroma of tendon sheath occurred in 5 males and 4 females in a younger age group (median age 32 years, range 12-46 years) as small soft tissue masses of the finger (n=5), hand (n=3) and wrist (n=1). USP6 rearrangements were detected in 6/9 cellular fibromas of tendon sheath. Among cellular fibromas of tendon sheath with USP6 rearrangements, no MYH9 rearrangements were detected. By RT-PCR, neither the MYH9-USP6 or the CDH11-USP6 fusion products were detected in any case. Neither USP6 nor MYH9 rearrangement were detected in any classic fibroma of tendon sheath. We report for the first time the presence of USP6 rearrangements in a subset of cellular fibroma of tendon sheath. Based on the similar morphological and molecular genetic features, we suspect that a subset of cellular fibromas of tendon sheath are under-recognized examples of tenosynovial nodular fasciitis, driven by alternate USP6 fusion

  5. Integrated cellular systems

    NASA Astrophysics Data System (ADS)

    Harper, Jason C.

    The generation of new three-dimensional (3D) matrices that enable integration of biomolecular components and whole cells into device architectures, without adversely altering their morphology or activity, continues to be an expanding and challenging field of research. This research is driven by the promise that encapsulated biomolecules and cells can significantly impact areas as diverse as biocatalysis, controlled delivery of therapeutics, environmental and industrial process monitoring, early warning of warfare agents, bioelectronics, photonics, smart prosthetics, advanced physiological sensors, portable medical diagnostic devices, and tissue/organ replacement. This work focuses on the development of a fundamental understanding of the biochemical and nanomaterial mechanisms that govern the cell directed assembly and integration process. It was shown that this integration process relies on the ability of cells to actively develop a pH gradient in response to evaporation induced osmotic stress, which catalyzes silica condensation within a thin 3D volume surrounding the cells, creating a functional bio/nano interface. The mechanism responsible for introducing functional foreign membrane-bound proteins via proteoliposome addition to the silica-lipid-cell matrix was also determined. Utilizing this new understanding, 3D cellular immobilization capabilities were extended using sol-gel matrices endowed with glycerol, trehalose, and media components. The effects of these additives, and the metabolic phase of encapsulated S. cerivisiase cells, on long-term viability and the rate of inducible gene expression was studied. This enabled the entrapment of cells within a novel microfluidic platform capable of simultaneous colorimetric, fluorescent, and electrochemical detection of a single analyte, significantly improving confidence in the biosensor output. As a complementary approach, multiphoton protein lithography was utilized to engineer 3D protein matrices in which to

  6. Morphology and enzyme production of Trichoderma reesei Rut C-30 are affected by the physical and structural characteristics of cellulosic substrates.

    PubMed

    Peciulyte, Ausra; Anasontzis, George E; Karlström, Katarina; Larsson, Per Tomas; Olsson, Lisbeth

    2014-11-01

    The industrial production of cellulolytic enzymes is dominated by the filamentous fungus Trichoderma reesei (anamorph of Hypocrea jecorina). In order to develop optimal enzymatic cocktail, it is of importance to understand the natural regulation of the enzyme profile as response to the growth substrate. The influence of the complexity of cellulose on enzyme production by the microorganisms is not understood. In the present study we attempted to understand how different physical and structural properties of cellulose-rich substrates affected the levels and profiles of extracellular enzymes produced by T. reesei. Enzyme production by T. reesei Rut C-30 was studied in submerged cultures on five different cellulose-rich substrates, namely, commercial cellulose Avicel® and industrial-like cellulosic pulp substrates which consist mainly of cellulose, but also contain residual hemicellulose and lignin. In order to evaluate the hydrolysis of the substrates by the fungal enzymes, the spatial polymer distributions were characterised by cross-polarisation magic angle spinning carbon-13 nuclear magnetic resonance (CP/MAS (13)C-NMR) in combination with spectral fitting. Proteins in culture supernatants at early and late stages of enzyme production were labeled by Tandem Mass Tags (TMT) and protein profiles were analysed by liquid chromatography-tandem mass spectrometry. The data have been deposited to the ProteomeXchange with identifier PXD001304. In total 124 proteins were identified and quantified in the culture supernatants, including cellulases, hemicellulases, other glycoside hydrolases, lignin-degrading enzymes, auxiliary activity 9 (AA9) family (formerly GH61), supporting activities of proteins and enzymes acting on cellulose, proteases, intracellular proteins and several hypothetical proteins. Surprisingly, substantial differences in the enzyme profiles were found even though there were minor differences in the chemical composition between the cellulose-rich substrates

  7. Mitochondrial Mg2+ homeostasis decides cellular energy metabolism and vulnerability to stress

    PubMed Central

    Yamanaka, Ryu; Tabata, Sho; Shindo, Yutaka; Hotta, Kohji; Suzuki, Koji; Soga, Tomoyoshi; Oka, Kotaro

    2016-01-01

    Cellular energy production processes are composed of many Mg2+ dependent enzymatic reactions. In fact, dysregulation of Mg2+ homeostasis is involved in various cellular malfunctions and diseases. Recently, mitochondria, energy-producing organelles, have been known as major intracellular Mg2+ stores. Several biological stimuli alter mitochondrial Mg2+ concentration by intracellular redistribution. However, in living cells, whether mitochondrial Mg2+ alteration affect cellular energy metabolism remains unclear. Mg2+ transporter of mitochondrial inner membrane MRS2 is an essential component of mitochondrial Mg2+ uptake system. Here, we comprehensively analyzed intracellular Mg2+ levels and energy metabolism in Mrs2 knockdown (KD) cells using fluorescence imaging and metabolome analysis. Dysregulation of mitochondrial Mg2+ homeostasis disrupted ATP production via shift of mitochondrial energy metabolism and morphology. Moreover, Mrs2 KD sensitized cellular tolerance against cellular stress. These results indicate regulation of mitochondrial Mg2+ via MRS2 critically decides cellular energy status and cell vulnerability via regulation of mitochondrial Mg2+ level in response to physiological stimuli. PMID:27458051

  8. Mitochondrial Mg(2+) homeostasis decides cellular energy metabolism and vulnerability to stress.

    PubMed

    Yamanaka, Ryu; Tabata, Sho; Shindo, Yutaka; Hotta, Kohji; Suzuki, Koji; Soga, Tomoyoshi; Oka, Kotaro

    2016-01-01

    Cellular energy production processes are composed of many Mg(2+) dependent enzymatic reactions. In fact, dysregulation of Mg(2+) homeostasis is involved in various cellular malfunctions and diseases. Recently, mitochondria, energy-producing organelles, have been known as major intracellular Mg(2+) stores. Several biological stimuli alter mitochondrial Mg(2+) concentration by intracellular redistribution. However, in living cells, whether mitochondrial Mg(2+) alteration affect cellular energy metabolism remains unclear. Mg(2+) transporter of mitochondrial inner membrane MRS2 is an essential component of mitochondrial Mg(2+) uptake system. Here, we comprehensively analyzed intracellular Mg(2+) levels and energy metabolism in Mrs2 knockdown (KD) cells using fluorescence imaging and metabolome analysis. Dysregulation of mitochondrial Mg(2+) homeostasis disrupted ATP production via shift of mitochondrial energy metabolism and morphology. Moreover, Mrs2 KD sensitized cellular tolerance against cellular stress. These results indicate regulation of mitochondrial Mg(2+) via MRS2 critically decides cellular energy status and cell vulnerability via regulation of mitochondrial Mg(2+) level in response to physiological stimuli. PMID:27458051

  9. Cellular Stress Responses and Monitored Cellular Activities.

    PubMed

    Sawa, Teiji; Naito, Yoshifumi; Kato, Hideya; Amaya, Fumimasa

    2016-08-01

    To survive, organisms require mechanisms that enable them to sense changes in the outside environment, introduce necessary responses, and resist unfavorable distortion. Consequently, through evolutionary adaptation, cells have become equipped with the apparatus required to monitor their fundamental intracellular processes and the mechanisms needed to try to offset malfunction without receiving any direct signals from the outside environment. It has been shown recently that eukaryotic cells are equipped with a special mechanism that monitors their fundamental cellular functions and that some pathogenic proteobacteria can override this monitoring mechanism to cause harm. The monitored cellular activities involved in the stressed intracellular response have been researched extensively in Caenorhabditis elegans, where discovery of an association between key mitochondrial activities and innate immune responses was named "cellular associated detoxification and defenses (cSADD)." This cellular surveillance pathway (cSADD) oversees core cellular activities such as mitochondrial respiration and protein transport into mitochondria, detects xenobiotics and invading pathogens, and activates the endocrine pathways controlling behavior, detoxification, and immunity. The cSADD pathway is probably associated with cellular responses to stress in human inflammatory diseases. In the critical care field, the pathogenesis of lethal inflammatory syndromes (e.g., respiratory distress syndromes and sepsis) involves the disturbance of mitochondrial respiration leading to cell death. Up-to-date knowledge about monitored cellular activities and cSADD, especially focusing on mitochondrial involvement, can probably help fill a knowledge gap regarding the pathogenesis of lethal inflammatory syndromes in the critical care field. PMID:26954943

  10. Musical morphology.

    PubMed

    Chakravarty, M Mallar; Vuust, Peter

    2009-07-01

    Morphologic measures have long been used to determine the patho-anatomical signature of different neurologic disorders. However, these measures can also be used to determine effects of specific learning tasks and quantifiable human abilities on cerebral structure. Musicians provide interesting opportunities for this type of analysis as their various skills, such as rhythmic ability and pitch and harmony discrimination (acquired through years of practicing and playing) can be quantified and compared using distinct morphologic analyses. Here, we review magnetic resonance imaging-based morphologic analyses in the music and neuroscience literature and provide some results from our own analysis of rhythmic ability in a cohort of musicians. PMID:19673757

  11. Cellular Phone Towers

    MedlinePlus

    ... the call. How are people exposed to the energy from cellular phone towers? As people use cell ... where people can be exposed to them. The energy from a cellular phone tower antenna, like that ...

  12. Hierarchical cellular materials

    SciTech Connect

    Gibson, L.J.

    1991-01-01

    In this paper a method for estimating the contributions of both the composite and the cellular microstructures to the overall material properties and the mechanical efficiency of natural cellular solids will be described. The method will be demonstrated by focusing on the Young's modulus; similar techniques can be used for other material properties. The results suggest efficient microstructures for engineered cellular materials.

  13. Hierarchical cellular materials

    SciTech Connect

    Gibson, L.J.

    1991-12-31

    In this paper a method for estimating the contributions of both the composite and the cellular microstructures to the overall material properties and the mechanical efficiency of natural cellular solids will be described. The method will be demonstrated by focusing on the Young`s modulus; similar techniques can be used for other material properties. The results suggest efficient microstructures for engineered cellular materials.

  14. Sperm Shape (Morphology): Does It Affect Fertility?

    MedlinePlus

    ... decide whether a couple should use in vitro fertilization (IVF) to attempt a pregnancy. It is best ... genetic material. Once the sperm enters the egg, fertilization has a good chance of taking place. However, ...

  15. The Roles of Cellular Nanomechanics in Cancer

    PubMed Central

    Yallapu, Murali M.; Katti, Kalpana S.; Katti, Dinesh R.; Mishra, Sanjay R.; Khan, Sheema; Jaggi, Meena; Chauhan, Subhash C.

    2014-01-01

    The biomechanical properties of cells and tissues may be instrumental in increasing our understanding of cellular behavior and cellular manifestations of diseases such as cancer. Nanomechanical properties can offer clinical translation of therapies beyond what are currently employed. Nanomechanical properties, often measured by nanoindentation methods using atomic force microscopy, may identify morphological variations, cellular binding forces, and surface adhesion behaviors that efficiently differentiate normal cells and cancer cells. The aim of this review is to examine current research involving the general use of atomic force microscopy/nanoindentation in measuring cellular nanomechanics; various factors and instrumental conditions that influence the nanomechanical properties of cells; and implementation of nanoindentation methods to distinguish cancer cells from normal cells or tissues. Applying these fundamental nanomechanical properties to current discoveries in clinical treatment may result in greater efficiency in diagnosis, treatment, and prevention of cancer, which ultimately can change the lives of patients. PMID:25137233

  16. Single chemical modifications of the C-1027 enediyne core, a radiomimetic antitumor drug, affect both drug potency and the role of ataxia-telangiectasia mutated in cellular responses to DNA double-strand breaks.

    PubMed

    Kennedy, Daniel R; Gawron, Loretta S; Ju, Jianhua; Liu, Wen; Shen, Ben; Beerman, Terry A

    2007-01-15

    The radiomimetic enediyne C-1027 induces almost exclusively DNA double-strand breaks (DSB) and is extremely cytotoxic. Unique among radiomimetics, ataxia-telangiectasia mutated (ATM) is dispensable for cellular responses to C-1027-induced DNA damage. This study explores the biological activity of three recently bioengineered C-1027 analogues: 7''-desmethyl-C-1027 (desmethyl), 20'-deschloro-C-1027 (deschloro), and 22'-deshydroxy-C-1027 (deshydroxy). Each compound maintains the characteristic ability of radiomimetics to cleave DNA in cell-free systems, varying in activity from 2-fold (deschloro) to 55-fold (desmethyl) less than C-1027. The induction of cellular DNA breaks based on pulsed field gel electrophoresis, comet analysis, and gammaH2AX activation was in the same rank order as cell-free DNA break induction, although the amount of breaks induced by desmethyl is greatly reduced compared with the other analogues. Despite the disparity in inducing DNA DSBs, all of the analogues produced G2-M cell cycle arrest and activated DNA DSB damage response proteins, such as p53-Ser15 and Chk2-Thr68, at concentrations in concordance with their ability to inhibit cell growth. Interestingly, of the three analogues, only the desmethyl-induced DNA damage response was similar to C-1027, as it did not cause hypersensitive cell growth inhibition in the absence of ATM nor require the kinase to phosphorylate p53 or Chk2. These findings show that simple modifications of the chromophore of C-1027 can result in varied induction of, and cellular response to, DNA DSBs. PMID:17234789

  17. MORPHOLOGICAL CONTROL OF MITOCHONDRIAL BIOENERGETICS

    PubMed Central

    Yu, Tianzheng; Wang, Li; Yoon, Yisang

    2015-01-01

    The major function of mitochondria is production and supply of cellular energy. Mitochondria are highly dynamic organelles undergoing frequent shape changes via fission and fusion. Many studies have elucidated the molecular components mediating fission and fusion and their regulatory mechanisms, and mitochondrial shape change is now recognized as an essential cellular process that is closely associated with functional states of mitochondria. This review updates the recent advancements in fission and fusion mechanisms, and discusses the bi-directional relationship between mitochondrial morphology and energetic states in physio-pathological settings. PMID:25553448

  18. QUANTITATIVE MORPHOLOGY

    EPA Science Inventory

    Abstract: In toxicology, the role of quantitative assessment of brain morphology can be understood in the context of two types of treatment-related alterations. One type of alteration is specifically associated with treatment and is not observed in control animals. Measurement ...

  19. Waterlogging and submergence stress: affects and acclimation.

    PubMed

    Phukan, Ujjal J; Mishra, Sonal; Shukla, Rakesh Kumar

    2016-10-01

    Submergence, whether partial or complete, imparts some serious consequences on plants grown in flood prone ecosystems. Some plants can endure these conditions by embracing various survival strategies, including morphological adaptations and physiological adjustments. This review summarizes recent progress made in understanding of the stress and the acclimation responses of plants under waterlogged or submerged conditions. Waterlogging and submergence are often associated with hypoxia development, which may trigger various morphological traits and cellular acclimation responses. Ethylene, abscisic acid, gibberellic acid and other hormones play a crucial role in the survival process which is controlled genetically. Effects at the cellular level, including ATP management, starch metabolism, elemental toxicity, role of transporters and redox status have been explained. Transcriptional and hormonal interplay during this stress may provide some key aspects in understanding waterlogging and submergence tolerance. The level and degree of tolerance may vary depending on species or climatic variations which need to be studied for a proper understanding of waterlogging stress at the global level. The exploration of regulatory pathways and interplay in model organisms such as Arabidopsis and rice would provide valuable resources for improvement of economically and agriculturally important plants in waterlogging affected areas. PMID:26177332

  20. Modelling cellular behaviour

    NASA Astrophysics Data System (ADS)

    Endy, Drew; Brent, Roger

    2001-01-01

    Representations of cellular processes that can be used to compute their future behaviour would be of general scientific and practical value. But past attempts to construct such representations have been disappointing. This is now changing. Increases in biological understanding combined with advances in computational methods and in computer power make it possible to foresee construction of useful and predictive simulations of cellular processes.

  1. Ultrasensitive Phase-Resolved Imaging of Cellular Morphology and Dynamics

    NASA Astrophysics Data System (ADS)

    Choma, Michael A.; Ellerbee, Audrey; Izatt, Joseph A.

    Microscopy is an important imaging tool in modern clinical medicine and basic biomedical research. The retrieval of phase information from microscopic samples has a long history initiated by the development of the phase contrast microscope. This technique exploits the fact that optically thin samples such as cells diffract light secondary to local variations in optical index. Phase contrast microscopy has had an immeasurable impact by allowing the user to qualitatively visualize small, subcellular variations in optical index. Quantitative phase microscopy seeks to build upon the principles of phase contrast microscopy to extract quantitative measures relating to optical index, birefringence, motion, and flow. In addition to highlighting subcellular detail in unstained cells, quantitative phase techniques can measure picometer-scale cell motions, small changes in cell index, and even cytoplasmic flow. Because of its sensitivity to phase and its ability to reliably quantify and track changes in coherent wavefronts, interferometry has recently gained momentum as a technique for the implementation of quantitative phase microscopy. This chapter reviews interferometric phase contrast microscopy techniques, with an emphasis on broadband interferometric techniques which exploit the principles of OCT. Both the underlying theory as well biological applications are discussed. Although this chapter gives particular focus to biologically relevant applications, the methods are readily extendable for other, nonbiological applications.

  2. Effect of surface tension anisotropy on cellular morphologies

    NASA Technical Reports Server (NTRS)

    Mcfadden, G. B.; Coriell, S. R.; Sekerka, R. F.

    1988-01-01

    A three-dimensional weakly nonlinear analysis for conditions near the onset of instability at the crystal-melt interface was carried out to second order, taking into account the effects of latent heat generation and surface-tension anisotropy of the crystal-melt interface; particular consideration was given to the growth of a cubic crystal in the 001-, 011-, and 111-line directions. Numerical calculations by McFadden et al. (1987), performed for an aluminum-chromium alloy with the assumption of a linear temperature field and an isotropic surface tension, showed that only hexagonal nodes (and not hexagonal cells) occurred near the onset of instability. The results of the present analysis indicate that the nonlinear temperature field (which occurs when thermal conductivities of the crystal and the melt are different and/or the latent heat effects are not negligible) can modify this result and, for certain alloys and processing conditions, can cause the occurrence of hexagonal cells near the onset of instability.

  3. Innate Cellular Immune Responses in Aedes caspius (Diptera: Culicidae) Mosquitoes.

    PubMed

    Soliman, D E; Farid, H A; Hammad, R E; Gad, A M; Bartholomay, L C

    2016-03-01

    Mosquitoes transmit a variety of pathogens that have devastating consequences for global public and veterinary health. Despite their capacity to serve as vectors, these insects have a robust capacity to respond to invading organisms with strong cellular and humoral immune responses. In Egypt, Aedes caspius (Pallas, 1771) has been suspected to act as a bridge vector of Rift Valley Fever virus between animals and humans. Microscopic analysis of Ae. caspius hemolymph revealed the presence of phagocytic cells called granulocytes. We further evaluated cellular immune responses produced by Ae. caspius as a result of exposure to a Gram-negative, and Gram-positive bacterium, and to latex beads. After challenge, a rapid and strong phagocytic response against either a natural or synthetic invader was evident. Hemocyte integrity in bacteria-inoculated mosquitoes was not morphologically affected. The number of circulating granulocytes decreased with age, reducing the overall phagocytic capacity of mosquitoes over time. The magnitude and speed of the phagocytic response suggested that granulocytes act as an important force in the battle against foreign invaders, as has been characterized in other important mosquito vector species. PMID:26792848

  4. Cellular respiration: the nexus of stress, condition, and ornamentation.

    PubMed

    Hill, Geoffrey E

    2014-10-01

    A fundamental hypothesis for the evolution and maintenance of ornamental traits is that ornaments convey information to choosing females about the quality of prospective mates. A diverse array of ornaments (e.g., colors, morphological features, and behaviors) has been associated with a wide range of measures of individual quality, but decades of study of such indicator traits have failed to produce general mechanisms of honest signaling. Here, I propose that efficiency of cellular respiration, as a product of mitochondrial function, underlies the associations between ornamentation and performance for a broad range of traits across taxa. A large biomedical literature documents the fundamental biochemical links between oxidative phosphorylation (OXPHOS) and the production of reactive oxygen species (ROS), the process of metabolism, the function of the immune system, the synthesis of proteins, and the development and function of the nervous system. The production of virtually all ornaments whose expressions have been demonstrated to be condition-dependent is directly affected by the efficiency of cellular respiration, suggesting that the signaling of respiratory efficiency may be the primary function of such traits. Furthermore, the production of ornaments links to stress-response systems, including particularly the neuroendocrine system, through mitochondrial function, thereby makes ornamental traits effective signals of the capacity to withstand environmental perturbations. The identification of a unifying mechanism of honest signaling holds the potential to connect many heretofore-disparate fields of study related to stress and ornamentation, including neuroendocrinology, respiratory physiology, metabolic physiology, and immunology. PMID:24791751

  5. Cellular complexity captured in durable silica biocomposites

    PubMed Central

    Kaehr, Bryan; Townson, Jason L.; Kalinich, Robin M.; Awad, Yasmine H.; Swartzentruber, B. S.; Dunphy, Darren R.; Brinker, C. Jeffrey

    2012-01-01

    Tissue-derived cultured cells exhibit a remarkable range of morphological features in vitro, depending on phenotypic expression and environmental interactions. Translation of these cellular architectures into inorganic materials would provide routes to generate hierarchical nanomaterials with stabilized structures and functions. Here, we describe the fabrication of cell/silica composites (CSCs) and their conversion to silica replicas using mammalian cells as scaffolds to direct complex structure formation. Under mildly acidic solution conditions, silica deposition is restricted to the molecularly crowded cellular template. Inter- and intracellular heterogeneity from the nano- to macroscale is captured and dimensionally preserved in CSCs following drying and subjection to extreme temperatures allowing, for instance, size and shape preserving pyrolysis of cellular architectures to form conductive carbon replicas. The structural and behavioral malleability of the starting material (cultured cells) provides opportunities to develop robust and economical biocomposites with programmed structures and functions. PMID:23045634

  6. Cellular Reflectarray Antenna

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R.

    2010-01-01

    The cellular reflectarray antenna is intended to replace conventional parabolic reflectors that must be physically aligned with a particular satellite in geostationary orbit. These arrays are designed for specified geographical locations, defined by latitude and longitude, each called a "cell." A particular cell occupies nominally 1,500 square miles (3,885 sq. km), but this varies according to latitude and longitude. The cellular reflectarray antenna designed for a particular cell is simply positioned to align with magnetic North, and the antenna surface is level (parallel to the ground). A given cellular reflectarray antenna will not operate in any other cell.

  7. E-cadherin expression on human carcinoma cell affects trastuzumab-mediated antibody-dependent cellular cytotoxicity through killer cell lectin-like receptor G1 on natural killer cells.

    PubMed

    Yamauchi, Chisako; Fujii, Satoshi; Kimura, Taichi; Kuwata, Takeshi; Wada, Noriaki; Mukai, Hirofumi; Matsumoto, Naoki; Fukayama, Masashi; Ochiai, Atsushi

    2011-05-01

    Trastuzumab is a recombinant antibody drug that is widely used for the treatment of HER2-overexpressing breast carcinoma. Despite encouraging clinical results, many HER2-overexpressing carcinomas are primarily resistant to trastuzumab. We attempted to explain trastuzumab resistance and search for solutions. Since the killer cell lectin-like receptor G1 (KLRG1), an inhibitory receptor expressed on subsets of natural killer (NK) cells recognizes E-cadherin as ligands and may inhibit immune responses by regulating the effector function of NK cells, we used HER2-overexpressing carcinoma cells which were expressing E-cadherin to investigate the role of antibody-dependent cellular cytotoxicity (ADCC) through KLRG1 on NK cells in vitro and vivo. The results indicated that HER2-overexpressing carcinoma cells were killed by trastuzumab-mediated ADCC and the ADCC activity was reflected the degree of E-cadherin expression on carcinoma cells. We found that expression of E-cadherin was shown to be a predictor of response to trastuzumab-based treatment for HER2-overexpressing carcinomas, furthermore, trastuzumab-mediated ADCC was markedly enhanced by KLRG1-negative peripheral blood mononuclear cells (PBMCs(KLRG1(-))). PMID:21387286

  8. Cellular Host Responses to Gliomas

    PubMed Central

    Barish, Michael E.; Garcia, Elizabeth; Metz, Marianne Z.; Myers, Sarah M.; Gutova, Margarita; Frank, Richard T.; Miletic, Hrvoje; Kendall, Stephen E.; Glackin, Carlotta A.; Bjerkvig, Rolf; Aboody, Karen S.

    2012-01-01

    Background Glioblastoma multiforme (GBM) is the most aggressive type of malignant primary brain tumors in adults. Molecular and genetic analysis has advanced our understanding of glioma biology, however mapping the cellular composition of the tumor microenvironment is crucial for understanding the pathology of this dreaded brain cancer. In this study we identified major cell populations attracted by glioma using orthotopic rodent models of human glioma xenografts. Marker-specific, anatomical and morphological analyses revealed a robust influx of host cells into the main tumor bed and tumor satellites. Methodology/Principal Findings Human glioma cell lines and glioma spheroid orthotopic implants were used in rodents. In both models, the xenografts recruited large numbers of host nestin-expressing cells, which formed a ‘network’ with glioma. The host nestin-expressing cells appeared to originate in the subventricular zone ipsilateral to the tumor, and were clearly distinguishable from pericytes that expressed smooth muscle actin. These distinct cell populations established close physical contact in a ‘pair-wise’ manner and migrated together to the deeper layers of tumor satellites and gave rise to tumor vasculature. The GBM biopsy xenografts displayed two different phenotypes: (a) low-generation tumors (first in vivo passage in rats) were highly invasive and non-angiogenic, and host nestin-positive cells that infiltrated into these tumors displayed astrocytic or elongated bipolar morphology; (b) high-generation xenografts (fifth passage) had pronounced cellularity, were angiogenic with ‘glomerulus-like’ microvascular proliferations that contained host nestin-positive cells. Stromal cell-derived factor-1 and its receptor CXCR4 were highly expressed in and around glioma xenografts, suggesting their role in glioma progression and invasion. Conclusions/Significance Our data demonstrate a robust migration of nestin-expressing host cells to glioma, which

  9. CELLULAR MAGNESIUM HOMEOSTASIS

    PubMed Central

    Romani, Andrea M.P.

    2011-01-01

    Magnesium, the second most abundant cellular cation after potassium, is essential to regulate numerous cellular functions and enzymes, including ion channels, metabolic cycles, and signaling pathways, as attested by more than 1000 entries in the literature. Despite significant recent progress, however, our understanding of how cells regulate Mg2+ homeostasis and transport still remains incomplete. For example, the occurrence of major fluxes of Mg2+ in either direction across the plasma membrane of mammalian cells following metabolic or hormonal stimuli has been extensively documented. Yet, the mechanisms ultimately responsible for magnesium extrusion across the cell membrane have not been cloned. Even less is known about the regulation in cellular organelles. The present review is aimed at providing the reader with a comprehensive and up-to-date understanding of the mechanisms enacted by eukaryotic cells to regulate cellular Mg2+ homeostasis and how these mechanisms are altered under specific pathological conditions. PMID:21640700

  10. Cellular viability and genetic expression of human gingival fibroblasts to zirconia with enamel matrix derivative (Emdogain®)

    PubMed Central

    Kwon, Yong-Dae; Choi, Hyun-jung; Lee, Heesu; Lee, Jung-Woo; Weber, Hans-Peter

    2014-01-01

    PURPOSE The objective of this study was to investigate the biologic effects of enamel matrix derivative (EMD) with different concentrations on cell viability and the genetic expression of human gingival fibroblasts (HGF) to zirconia surfaces. MATERIALS AND METHODS Immortalized human gingival fibroblasts (HGF) were cultured (1) without EMD, (2) with EMD 25 µg/mL, and (3) with EMD 100 µg/mL on zirconia discs. MTT assay was performed to evaluate the cell proliferation activity and SEM was carried out to examine the cellular morphology and attachment. The mRNA expression of collagen type I, osteopontin, fibronectin, and TGF-β1 was evaluated with the real-time polymerase chain reaction (RT-PCR). RESULTS From MTT assay, HGF showed more proliferation in EMD 25 µg/mL group than control and EMD 100 µg/mL group (P<.05). HGFs showed more flattened cellular morphology on the experimental groups than on the control group after 4h culture and more cellular attachments were observed on EMD 25 µg/mL group and EMD 100 µg/mL group after 24h culture. After 48h of culture, cellular attachment was similar in all groups. The mRNA expression of type I collagen increased in a concentration dependent manner. The genetic expression of osteopontin, fibronectin, and TGF-β1 was increased at EMD 100 µg/mL. However, the mRNA expression of proteins associated with cellular attachment was decreased at EMD 25 µg/mL. CONCLUSION Through this short term culture of HGF on zirconium discs, we conclude that EMD affects the proliferation, attachment, and cell morphology of HGF cells. Also, EMD stimulates production of extracellular matrix collagen, osteopontin, and TGF-β1 in high concentration levels. CLINICAL RELEVANCE With the use of EMD, protective barrier between attached gingiva and transmucosal zirconia abutment may be enhanced leading to final esthetic results with implants. PMID:25352963

  11. Measurement Techniques for Cellular Biomechanics In Vitro

    PubMed Central

    Addae-Mensah, Kweku A; Wikswo, John P

    2014-01-01

    Living cells and tissues experience mechanical forces in their physiological environments that are known to affect many cellular processes. Also of importance are the mechanical properties of cells, as well as the microforces generated by cellular processes themselves in their microenvironments. The difficulty associated with studying these phenomena in vivo has led to alternatives such as using in vitro models. The need for experimental techniques for investigating cellular biomechanics and mechanobiology in vitro has fueled an evolution in the technology used in these studies. Particularly noteworthy are some of the new biomicroelectromechanical systems (BioMEMs) devices and techniques that have been introduced to the field. We describe some of the cellular micromechanical techniques and methods that have been developed for in vitro studies, and provide summaries of the ranges of measured values of various biomechanical quantities. We also briefly address some of our experiences in using these methods and include modifications we have introduced in order to improve them. PMID:18445766

  12. Effect of human immunodeficiency virus type 1 protein R (vpr) gene expression on basic cellular function of fission yeast Schizosaccharomyces pombe.

    PubMed Central

    Zhao, Y; Cao, J; O'Gorman, M R; Yu, M; Yogev, R

    1996-01-01

    The human immunodeficiency virus type 1 (HIV-1) Vpr protein affects cell morphology and prevents proliferation of human cells by induction of cell cycle G2 arrest. In this study, we used the fission yeast Schizosaccharomyces pombe as a model system to investigate the cellular effects of HIV-1 vpr gene expression. The vpr gene was cloned into an inducible fission yeast gene expression vector and expressed in wild-type S. pombe cells, and using these cells, we were able to demonstrate the specific Vpr-induced effects by induction and suppression of vpr gene expression. Induction of HIV-1 vpr gene expression affected S. pombe at the colonial, cellular, and molecular levels. Specifically, Vpr induced small-colony formation, polymorphic cells, growth delay, and cell cycle G2 arrest. Additionally, Vpr-induced G2 arrest appeared to be independent of cell size and morphological changes. The cell cycle G2 arrest correlated with increased phosphorylation of p34cdc2, suggesting negative regulation of mitosis by HIV-1 Vpr. Treatment of Vpr-induced cell with a protein phosphatase inhibitor, okadaic acid, transiently suppressed cell cycle arrest and morphological changes. This observation implicates possible involvement of protein phosphatase(s) in the effects of Vpr. Together, these data showed that the HIV-1 Vpr-induced cellular changes in S. pombe are similar to those observed in human cells. Therefore, the S. pombe system is suited for further investigation of the HIV-1 vpr gene functions. PMID:8709199

  13. A scientific role for Space Station Freedom: Research at the cellular level

    NASA Technical Reports Server (NTRS)

    Johnson, Terry C.; Brady, John N.

    1993-01-01

    The scientific importance of Space Station Freedom is discussed in light of the valuable information that can be gained in cellular and developmental biology with regard to the microgravity environment on the cellular cytoskeleton, cellular responses to extracellular signal molecules, morphology, events associated with cell division, and cellular physiology. Examples of studies in basic cell biology, as well as their potential importance to concerns for future enabling strategies, are presented.

  14. Cellular Homeostasis and Aging.

    PubMed

    Hartl, F Ulrich

    2016-06-01

    Aging and longevity are controlled by a multiplicity of molecular and cellular signaling events that interface with environmental factors to maintain cellular homeostasis. Modulation of these pathways to extend life span, including insulin-like signaling and the response to dietary restriction, identified the cellular machineries and networks of protein homeostasis (proteostasis) and stress resistance pathways as critical players in the aging process. A decline of proteostasis capacity during aging leads to dysfunction of specific cell types and tissues, rendering the organism susceptible to a range of chronic diseases. This volume of the Annual Review of Biochemistry contains a set of two reviews addressing our current understanding of the molecular mechanisms underlying aging in model organisms and humans. PMID:27050288

  15. Architected Cellular Materials

    NASA Astrophysics Data System (ADS)

    Schaedler, Tobias A.; Carter, William B.

    2016-07-01

    Additive manufacturing enables fabrication of materials with intricate cellular architecture, whereby progress in 3D printing techniques is increasing the possible configurations of voids and solids ad infinitum. Examples are microlattices with graded porosity and truss structures optimized for specific loading conditions. The cellular architecture determines the mechanical properties and density of these materials and can influence a wide range of other properties, e.g., acoustic, thermal, and biological properties. By combining optimized cellular architectures with high-performance metals and ceramics, several lightweight materials that exhibit strength and stiffness previously unachievable at low densities were recently demonstrated. This review introduces the field of architected materials; summarizes the most common fabrication methods, with an emphasis on additive manufacturing; and discusses recent progress in the development of architected materials. The review also discusses important applications, including lightweight structures, energy absorption, metamaterials, thermal management, and bioscaffolds.

  16. Irregular Cellular Learning Automata.

    PubMed

    Esnaashari, Mehdi; Meybodi, Mohammad Reza

    2015-08-01

    Cellular learning automaton (CLA) is a recently introduced model that combines cellular automaton (CA) and learning automaton (LA). The basic idea of CLA is to use LA to adjust the state transition probability of stochastic CA. This model has been used to solve problems in areas such as channel assignment in cellular networks, call admission control, image processing, and very large scale integration placement. In this paper, an extension of CLA called irregular CLA (ICLA) is introduced. This extension is obtained by removing the structure regularity assumption in CLA. Irregularity in the structure of ICLA is needed in some applications, such as computer networks, web mining, and grid computing. The concept of expediency has been introduced for ICLA and then, conditions under which an ICLA becomes expedient are analytically found. PMID:25291810

  17. Oleanolic acid and ursolic acid affect peptidoglycan metabolism in Listeria monocytogenes.

    PubMed

    Kurek, Anna; Grudniak, Anna M; Szwed, Magdalena; Klicka, Anna; Samluk, Lukasz; Wolska, Krystyna I; Janiszowska, Wirginia; Popowska, Magdalena

    2010-01-01

    The plant pentacyclic triterpenoids, oleanolic and ursolic acids, inhibit the growth and survival of many bacteria, particularly Gram-positive species, including pathogenic ones. The effect of these compounds on the facultative human pathogen Listeria monocytogenes was examined. Both acids affected cell morphology and enhanced autolysis of the bacterial cells. Autolysis of isolated cell walls was inhibited by oleanolic acid, but the inhibitory activity of ursolic acid was less pronounced. Both compounds inhibited peptidoglycan turnover and quantitatively affected the profile of muropeptides obtained after digestion of peptidoglycan with mutanolysin. These results suggest that peptidoglycan metabolism is a cellular target of oleanolic and ursolic acids. PMID:19894138

  18. The 37/67kDa laminin receptor (LR) inhibitor, NSC47924, affects 37/67kDa LR cell surface localization and interaction with the cellular prion protein

    PubMed Central

    Sarnataro, Daniela; Pepe, Anna; Altamura, Gennaro; De Simone, Imma; Pesapane, Ada; Nitsch, Lucio; Montuori, Nunzia; Lavecchia, Antonio; Zurzolo, Chiara

    2016-01-01

    The 37/67 kDa laminin receptor (LR) is a non-integrin protein, which binds both laminin-1 of the extracellular matrix and prion proteins, that hold a central role in prion diseases. The 37/67 kDa LR has been identified as interactor for the prion protein (PrPC) and to be required for pathological PrP (PrPSc) propagation in scrapie-infected neuronal cells, leading to the possibility that 37/67 kDa LR-PrPC interaction is related to the pathogenesis of prion diseases. A relationship between 37/67 kDa LR and PrPC in the presence of specific LR inhibitor compounds has not been investigated yet. We have characterized the trafficking of 37/67 kDa LR in both neuronal and non-neuronal cells, finding the receptor on the cell surface and nuclei, and identified the 67 kDa LR as the almost exclusive isoform interacting with PrPC. Here, we show that the treatment with the 37/67 kDa LR inhibitor, NSC47924, affects both the direct 37/67 kDa LR-PrPC interaction in vitro and the formation of the immunocomplex in live cells, inducing a progressive internalization of 37/67 kDa LR and stabilization of PrPC on the cell surface. These data reveal NSC47924 as a useful tool to regulate PrPC and 37/67 kDa LR trafficking and degradation, representing a novel small molecule to be tested against prion diseases. PMID:27071549

  19. Probing cellular behaviors through nanopatterned chitosan membranes

    NASA Astrophysics Data System (ADS)

    Yang, Chung-Yao; Sung, Chun-Yen; Shuai, Hung-Hsun; Cheng, Chao-Min; Yeh, Andrew

    2013-08-01

    This paper describes a high-throughput method for developing physically modified chitosan membranes to probe the cellular behavior of MDCK epithelial cells and HIG-82 fibroblasts adhered onto these modified membranes. To prepare chitosan membranes with micro/nanoscaled features, we have demonstrated an easy-to-handle, facile approach that could be easily integrated with IC-based manufacturing processes with mass production potential. These physically modified chitosan membranes were observed by scanning electron microscopy to gain a better understanding of chitosan membrane surface morphology. After MDCK cells and HIG-82 fibroblasts were cultured on these modified chitosan membranes for various culture durations (i.e. 1, 2, 4, 12 and 24 h), they were investigated to decipher cellular behavior. We found that both cells preferred to adhere onto a flat surface rather than on a nanopatterned surface. However, most (> 80%) of the MDCK cells showed rounded morphology and would suspend in the cultured medium instead of adhering onto the planar surface of negatively nanopatterned chitosan membranes. This means different cell types (e.g. fibroblasts versus epithelia) showed distinct capabilities/preferences of adherence for materials of varying surface roughness. We also showed that chitosan membranes could be re-used at least nine times without significant contamination and would provide us consistency for probing cell-material interactions by permitting reuse of the same substrate. We believe these results would provide us better insight into cellular behavior, specifically, microscopic properties and characteristics of cells grown under unique, nanopatterned cell-interface conditions.

  20. Morphology engineering of Aspergillus niger for improved enzyme production.

    PubMed

    Driouch, Habib; Sommer, Becky; Wittmann, Christoph

    2010-04-15

    Supplementation with silicate microparticles was used as novel approach to control the morphological development of Aspergillus niger, important as the major world source of citric acid and higher-value enzymes, in submerged culture. With careful variation of size and concentration of the micromaterial added, a number of distinct morphological forms including pellets of different size, free dispersed mycelium, and short hyphae fragments could be reproducibly created. Aluminum oxide particles similarly affected morphology, showing that this effect is largely independent of the chemical particle composition. Image analysis of morphological development of A. niger during the cultivation process showed that the microparticles influence the morphology by collision-induced disruption of conidia aggregates and probably also the hindrance of new spore-spore interactions in the very early stage of the process. Exemplified for different recombinant A. niger strains enzyme production could be strongly enhanced by the addition of microparticles. Linked to the formation of freely dispersed mycelium, titers for glucoamylase (GA) expressed as intracellular enzyme (88 U/mL) and fructofuranosidase secreted into the supernatant (77 U/mL), were up to fourfold higher in shake flasks. Moreover, accumulation of the undesired by-product oxalate was suppressed by up to 90%. The microparticle strategy could be successfully transferred to fructofuranosidase production in bioreactor, where a final titer of 160 U/mL could be reached. Using co-expression of GA with green fluorescent protein, enzyme production was localized in the cellular aggregates of A. niger. For pelleted growth, protein production was maximal only within a thin layer at the pellet surface and markedly decreased in the pellet interior, whereas the interaction with the microparticles created a highly active biocatalyst with the dominant fraction of cells contributing to production. PMID:19953678

  1. Teaching cellular engineering.

    PubMed

    Hammer, Daniel A; Waugh, Richard E

    2006-02-01

    Cellular engineering is one of the fastest growing subdisciplines in the field of Biomedical Engineering. It involves the application of engineering analysis to understand and control cellular behavior, with the ultimate objective of developing novel therapeutic or diagnostic approaches for the clinic or harnessing cellular function for commercial applications. Well-educated students in this area need strong foundational knowledge in engineering science, chemistry, and cell and molecular biology. In undergraduate curricula, the challenge is to include essential engineering skills plus appropriate levels of training in chemistry and biology while satisfying accreditation-mandated breadth in engineering training. At the graduate level, educators must accommodate students with diverse backgrounds and provide them with both a state-of-the-art understanding of the life sciences and the most advanced engineering skills. Engineering curricular content should include mechanics and materials, physical chemistry, transport phenomena, and control theory. Training from faculty with appointments and research programs in the life sciences is generally recommended, and additional life science content should also be integrated within the engineering curriculum. A capstone course in cellular engineering that includes opportunities for students to have hands-on experiences with state-of-the-art laboratory techniques is highly recommended. PMID:16450196

  2. Auxin and Cellular Elongation.

    PubMed

    Velasquez, Silvia Melina; Barbez, Elke; Kleine-Vehn, Jürgen; Estevez, José M

    2016-03-01

    Auxin is a crucial growth regulator in plants. However, a comprehensive understanding of how auxin induces cell expansion is perplexing, because auxin acts in a concentration- and cell type-dependent manner. Consequently, it is desirable to focus on certain cell types to exemplify the underlying growth mechanisms. On the other hand, plant tissues display supracellular growth (beyond the level of single cells); hence, other cell types might compromise the growth of a certain tissue. Tip-growing cells do not display neighbor-induced growth constraints and, therefore, are a valuable source of information for growth-controlling mechanisms. Here, we focus on auxin-induced cellular elongation in root hairs, exposing a mechanistic view of plant growth regulation. We highlight a complex interplay between auxin metabolism and transport, steering root hair development in response to internal and external triggers. Auxin signaling modules and downstream cascades of transcription factors define a developmental program that appears rate limiting for cellular growth. With this knowledge in mind, the root hair cell is a very suitable model system in which to dissect cellular effectors required for cellular expansion. PMID:26787325

  3. The New Cellular Immunology

    ERIC Educational Resources Information Center

    Claman, Henry N.

    1973-01-01

    Discusses the nature of the immune response and traces many of the discoveries that have led to the present state of knowledge in immunology. The new cellular immunology is directing its efforts toward improving health by proper manipulation of the immune mechanisms of the body. (JR)

  4. Cellular ageing mechanisms in osteoarthritis.

    PubMed

    Sacitharan, P K; Vincent, T L

    2016-08-01

    Age is the strongest independent risk factor for the development of osteoarthritis (OA) and for many years this was assumed to be due to repetitive microtrauma of the joint surface over time, the so-called 'wear and tear' arthritis. As our understanding of OA pathogenesis has become more refined, it has changed our appreciation of the role of ageing on disease. Cartilage breakdown in disease is not a passive process but one involving induction and activation of specific matrix-degrading enzymes; chondrocytes are exquisitely sensitive to changes in the mechanical, inflammatory and metabolic environment of the joint; cartilage is continuously adapting to these changes by altering its matrix. Ageing influences all of these processes. In this review, we will discuss how ageing affects tissue structure, joint use and the cellular metabolism. We describe what is known about pathways implicated in ageing in other model systems and discuss the potential value of targeting these pathways in OA. PMID:27215642

  5. Fabrication of cellular materials

    NASA Astrophysics Data System (ADS)

    Prud'homme, Robert K.; Aksay, Ilhan A.; Garg, Rajeev

    1996-02-01

    Nature uses cellular materials in applications requiring strength while, simultaneously, minimizing raw materials requirements. Minimizing raw materials is efficient both in terms of the energy expended by the organism to synthesize the structure and in terms of the strength- to-weight ratio of the structure. Wood is the most obvious example of cellular bio-materials, and it is the focus of other presentations in this symposium. The lightweight bone structure of birds is another excellent example where weight is a key criterion. The anchoring foot of the common muscle [Mytilus edulis] whereby it attaches itself to objects is a further example of a biological system that uses a foam to fill space and yet conserve on raw materials. In the case of the muscle the foam is water filled and the foot structure distributes stress over a larger area so that the strength of the byssal thread from which it is suspended is matched to the strength of interfacial attachment of the foot to a substrate. In these examples the synthesis and fabrication of the cellular material is directed by intercellular, genetically coded, biochemical reactions. The resulting cell sizes are microns in scale. Cellular materials at the next larger scale are created by organisms at the next higher level of integration. For example an African tree frog lays her eggs in a gas/fluid foam sack she builds on a branch overhanging a pond. The outside of the foam sack hardens in the sun and prevents water evaporation. The foam structure minimizes the amount of fluid that needs to be incorporated into the sack and minimizes its weight. However, as far as the developing eggs are concerned, they are in an aqueous medium, i.e. the continuous fluid phase of the foam. After precisely six days the eggs hatch, and the solidified outer wall re-liquefies and dumps the emerging tadpoles into the pond below. The bee honeycomb is an example of a cellular material with exquisite periodicity at millimeter length scales. The

  6. Inducing cellular senescence using defined genetic elements.

    PubMed

    Nakagawa, Hiroshi; Opitz, Oliver G

    2007-01-01

    Cellular senescence is generally defined as an irreversible state of G1 cell cycle arrest in which cells are refractory to growth factor stimulation. Cellular senescence can be induced through several different mechanisms. Primary mammalian cells display a finite life span, suggesting a mechanism that counts cell divisions. Those cells initially proliferate but eventually enter a state of permanent growth arrest, called replicative senescence. Erosion of telomeric DNA has emerged as a key factor in replicative senescence, which is antagonized during cell immortalization. Nevertheless, besides telomere shortening, there are other mechanisms inducing a growth arrest similar to the replicative senescencent phenotype. Oncogenic or mitogenic signals as well as DNA damage can induce such a phenotype of cellular senescence. All forms of cellular senescence share common signaling pathways and morphological features. Thereby, p53 seems to be essential for the senescence response. Many of these senescence inducing mechanisms can be experimentally recapitulated by the introduction of defined genetic elements. Replicative senescence due to telomere shortening can, for example, be induced by a dominant negative version of telomerase, premature senescence by the overexpression of oncogenic ras, or p16. PMID:17634581

  7. Cellular basis of memory for addiction.

    PubMed

    Nestler, Eric J

    2013-12-01

    DESPITE THE IMPORTANCE OF NUMEROUS PSYCHOSOCIAL FACTORS, AT ITS CORE, DRUG ADDICTION INVOLVES A BIOLOGICAL PROCESS: the ability of repeated exposure to a drug of abuse to induce changes in a vulnerable brain that drive the compulsive seeking and taking of drugs, and loss of control over drug use, that define a state of addiction. Here, we review the types of molecular and cellular adaptations that occur in specific brain regions to mediate addiction-associated behavioral abnormalities. These include alterations in gene expression achieved in part via epigenetic mechanisms, plasticity in the neurophysiological functioning of neurons and synapses, and associated plasticity in neuronal and synaptic morphology mediated in part by altered neurotrophic factor signaling. Each of these types of drug-induced modifications can be viewed as a form of "cellular or molecular memory." Moreover, it is striking that most addiction-related forms of plasticity are very similar to the types of plasticity that have been associated with more classic forms of "behavioral memory," perhaps reflecting the finite repertoire of adaptive mechanisms available to neurons when faced with environmental challenges. Finally, addiction-related molecular and cellular adaptations involve most of the same brain regions that mediate more classic forms of memory, consistent with the view that abnormal memories are important drivers of addiction syndromes. The goal of these studies which aim to explicate the molecular and cellular basis of drug addiction is to eventually develop biologically based diagnostic tests, as well as more effective treatments for addiction disorders. PMID:24459410

  8. Long-wave interactions in morphological and convective instabilities

    NASA Technical Reports Server (NTRS)

    Riley, D. S.; Davis, S. H.

    1990-01-01

    A binary liquid that undergoes directional solidification is susceptible to morphological and solutal-convective instabilities that cause the solid/liquid interface to change from a planar to a cellular state. This paper gives derivations for those long-wave evolution equations that describe the weak couplings between convection and interface morphology and gives some analytical results obtainable from these.

  9. Cellular growth in biofilms

    SciTech Connect

    Wood, B.D.; Whitaker, S.

    1999-09-20

    In this paper the authors develop a macroscopic evolutionary equation for the growth of the cellular phase starting from a microscopic description of mass transport and a simple structured model for product formation. The methods of continuum mechanics and volume averaging are used to develop the macroscopic representation by carefully considering the fluxes of chemical species that pertain to cell growth. The concept of structured models is extended to include the transport of reacting chemical species at the microscopic scale. The resulting macroscopic growth model is similar in form to previously published models for the transport of a single substrate and electron donor and for the production of cellular mass and exopolymer. The method of volume averaging indicated under what conditions the developed growth model is valid and provides an explicit connection between the relevant microscopic model parameters and their corresponding macroscopic counterparts.

  10. Cellular dysfunction in sepsis.

    PubMed

    Singer, Mervyn

    2008-12-01

    Cellular dysfunction is a commonplace sequelum of sepsis and other systemic inflammatory conditions. Impaired energy production (related to mitochondrial inhibition, damage, and reduced protein turnover) appears to be a core mechanism underlying the development of organ dysfunction. The reduction in energy availability appears to trigger a metabolic shutdown that impairs normal functioning of the cell. This may well represent an adaptive mechanism analogous to hibernation that prevents a massive degree of cell death and thus enables eventual recovery in survivors. PMID:18954700

  11. Radiolabeled cellular blood elements

    SciTech Connect

    Thakur, M.L.; Ezikowitz, M.D.; Hardeman, M.R.

    1985-01-01

    This book contains papers delivered by guest lectures and participants at the Advanced Study Institute's colloquium on Radiolabeled Cellular Blood Elements at Maratea, Italy on August 29, to September 9, 1982. The book includes chapters on basic cell physiology and critical reviews of data and experience in the preparation and use of radiolabeled cells, as well as reports on very recent developments, from a faculty that included experts on cell physiology in health and disease and on the technology of in vivo labeling.

  12. Crack Propagation in Bamboo's Hierarchical Cellular Structure

    PubMed Central

    Habibi, Meisam K.; Lu, Yang

    2014-01-01

    Bamboo, as a natural hierarchical cellular material, exhibits remarkable mechanical properties including excellent flexibility and fracture toughness. As far as bamboo as a functionally graded bio-composite is concerned, the interactions of different constituents (bamboo fibers; parenchyma cells; and vessels.) alongside their corresponding interfacial areas with a developed crack should be of high significance. Here, by using multi-scale mechanical characterizations coupled with advanced environmental electron microscopy (ESEM), we unambiguously show that fibers' interfacial areas along with parenchyma cells' boundaries were preferred routes for crack growth in both radial and longitudinal directions. Irrespective of the honeycomb structure of fibers along with cellular configuration of parenchyma ground, the hollow vessels within bamboo culm affected the crack propagation too, by crack deflection or crack-tip energy dissipation. It is expected that the tortuous crack propagation mode exhibited in the present study could be applicable to other cellular natural materials as well. PMID:24998298

  13. Differential cellular effects of electroporation and electrochemotherapy in monolayers of human microvascular endothelial cells.

    PubMed

    Meulenberg, Cécil J W; Todorovic, Vesna; Cemazar, Maja

    2012-01-01

    In vivo electroporation of tumours shows disruption of blood flow and creates a vascular effect with an initial rapid and transient vasoconstriction phase and a much longer lasting phase with changed microvascular endothelium. These changes are not well understood but are presumed to involve the cytoskeleton. The paper presents for the first time differential in vitro effects describing cytoskeleton changes and monolayer integrity changes by both electroporation and electrochemotherapy of monolayers of human microvascular endothelial cells (HMEC-1). After the application of electric field pulses, the morphology of cells, and both the F-actin and Beta-tubulin cytoskeleton proteins were affected. During both electroporation and electrochemotherapy, the initial phase of cellular damage was noticed at 10 min as swollen cells and honeycomb-like actin bundles. The electroporation-induced cellular effects, observed from electric pulses >150 V, were voltage-dependent and within 24 hrs partly recoverable. The electrochemotherapy-induced cellular effects developed at 2 hrs in spindle-like cells, and more densely packed F-actin and Beta-tubulin were observed, which were dependent on the amount of bleomycin and the voltages applied (>50 V). In addition, for electrochemotherapy with electric pulses >150 V cellular changes were not recoverable within 24 hrs. The effects on monolayer integrity were reflected in the enhanced monolayer permeability, with the electrochemotherapy showing an earlier onset and synergy. We conclude that electrochemotherapy as compared to electroporation leads within 24 hrs to a quicker and more pronounced monolayer integrity damage and endothelial cell death, which together provide further insight into the cellular changes of the vascular disruption of electrochemotherapy. PMID:23300747

  14. Predictability in cellular automata.

    PubMed

    Agapie, Alexandru; Andreica, Anca; Chira, Camelia; Giuclea, Marius

    2014-01-01

    Modelled as finite homogeneous Markov chains, probabilistic cellular automata with local transition probabilities in (0, 1) always posses a stationary distribution. This result alone is not very helpful when it comes to predicting the final configuration; one needs also a formula connecting the probabilities in the stationary distribution to some intrinsic feature of the lattice configuration. Previous results on the asynchronous cellular automata have showed that such feature really exists. It is the number of zero-one borders within the automaton's binary configuration. An exponential formula in the number of zero-one borders has been proved for the 1-D, 2-D and 3-D asynchronous automata with neighborhood three, five and seven, respectively. We perform computer experiments on a synchronous cellular automaton to check whether the empirical distribution obeys also that theoretical formula. The numerical results indicate a perfect fit for neighbourhood three and five, which opens the way for a rigorous proof of the formula in this new, synchronous case. PMID:25271778

  15. Probabilistic cellular automata.

    PubMed

    Agapie, Alexandru; Andreica, Anca; Giuclea, Marius

    2014-09-01

    Cellular automata are binary lattices used for modeling complex dynamical systems. The automaton evolves iteratively from one configuration to another, using some local transition rule based on the number of ones in the neighborhood of each cell. With respect to the number of cells allowed to change per iteration, we speak of either synchronous or asynchronous automata. If randomness is involved to some degree in the transition rule, we speak of probabilistic automata, otherwise they are called deterministic. With either type of cellular automaton we are dealing with, the main theoretical challenge stays the same: starting from an arbitrary initial configuration, predict (with highest accuracy) the end configuration. If the automaton is deterministic, the outcome simplifies to one of two configurations, all zeros or all ones. If the automaton is probabilistic, the whole process is modeled by a finite homogeneous Markov chain, and the outcome is the corresponding stationary distribution. Based on our previous results for the asynchronous case-connecting the probability of a configuration in the stationary distribution to its number of zero-one borders-the article offers both numerical and theoretical insight into the long-term behavior of synchronous cellular automata. PMID:24999557

  16. Quantum cellular automata

    NASA Astrophysics Data System (ADS)

    Porod, Wolfgang; Lent, Craig S.; Bernstein, Gary H.

    1994-06-01

    The Notre Dame group has developed a new paradigm for ultra-dense and ultra-fast information processing in nanoelectronic systems. These Quantum Cellular Automata (QCA's) are the first concrete proposal for a technology based on arrays of coupled quantum dots. The basic building block of these cellular arrays is the Notre Dame Logic Cell, as it has been called in the literature. The phenomenon of Coulomb exclusion, which is a synergistic interplay of quantum confinement and Coulomb interaction, leads to a bistable behavior of each cell which makes possible their use in large-scale cellular arrays. The physical interaction between neighboring cells has been exploited to implement logic functions. New functionality may be achieved in this fashion, and the Notre Dame group invented a versatile majority logic gate. In a series of papers, the feasibility of QCA wires, wire crossing, inverters, and Boolean logic gates was demonstrated. A major finding is that all logic functions may be integrated in a hierarchial fashion which allows the design of complicated QCA structures. The most complicated system which was simulated to date is a one-bit full adder consisting of some 200 cells. In addition to exploring these new concepts, efforts are under way to physically realize such structures both in semiconductor and metal systems. Extensive modeling work of semiconductor quantum dot structures has helped identify optimum design parameters for QCA experimental implementations.

  17. Effect of structure, topography and chemistry on fibroblast adhesion and morphology.

    PubMed

    Mateos-Timoneda, Miguel A; Castano, Oscar; Planell, Josep A; Engel, Elisabeth

    2014-07-01

    Surface biofunctionalisation of many biodegradable polymers is one of the used strategies to improve the biological activity of such materials. In this work, the introduction of collagen type I over the surface of a biodegradable polymer (poly lactic acid) processed in the forms of films and fibers leads to an enhancing of the cellular adhesion of human dermal fibroblast when compared to unmodified polymer and biomolecule-physisorbed polymer surface. The change of topography of the material does not affect the cellular adhesion but results in a higher proliferation of the fibroblast cultured over the fibers. Moreover, the difference of topography governs the cellular morphology, i.e. cells adopt a more stretched conformation where cultured over the films while a more elongated with lower area morphology are obtained for the cells grown over the fibers. This study is relevant for designing and modifying different biodegradable polymers for their use as scaffolds for different applications in the field of Tissue Engineering and Regenerative Medicine. PMID:24668270

  18. Aging cellular networks: chaperones as major participants.

    PubMed

    Soti, C; Csermely, P

    2007-01-01

    We increasingly rely on the network approach to understand the complexity of cellular functions. Chaperones (heat shock proteins) are key "networkers", which sequester and repair damaged proteins. In order to link the network approach and chaperones with the aging process, we first summarize the properties of aging networks suggesting a "weak link theory of aging". This theory suggests that age-related random damage primarily affects the overwhelming majority of the low affinity, transient interactions (weak links) in cellular networks leading to increased noise, destabilization and diversity. These processes may be further amplified by age-specific network remodelling and by the sequestration of weakly linked cellular proteins to protein aggregates of aging cells. Chaperones are weakly linked hubs (i.e., network elements with a large number of connections) and inter-modular bridge elements of protein-protein interaction, signalling and mitochondrial networks. As aging proceeds, the increased overload of damaged proteins is an especially important element contributing to cellular disintegration and destabilization. Additionally, chaperone overload may contribute to the increase of "noise" in aging cells, which leads to an increased stochastic resonance resulting in a deficient discrimination between signals and noise. Chaperone- and other multi-target therapies, which restore the missing weak links in aging cellular networks, may emerge as important anti-aging interventions. PMID:16814508

  19. Cellular phones: are they detrimental?

    PubMed

    Salama, Osama E; Abou El Naga, Randa M

    2004-01-01

    The issue of possible health effects of cellular phones is very much alive in the public's mind where the rapid increase in the number of the users of cell phones in the last decade has increased the exposure of people to the electromagnetic fields (EMFs). Health consequences of long term use of mobile phones are not known in detail but available data indicates the development of non specific annoying symptoms on acute exposure to mobile phone radiations. In an attempt to determine the prevalence of such cell phones associated health manifestations and the factors affecting their occurrence, a cross sectional study was conducted in five randomly selected faculties of Alexandria University. Where, 300 individuals including teaching staff, students and literate employee were equally allocated and randomly selected among the five faculties. Data about mobile phone's users and their medical history, their pattern of mobile usage and the possible deleterious health manifestations associated with cellular phone use was collected. The results revealed 68% prevalence of mobile phone usage, nearly three quarters of them (72.5%) were complainers of the health manifestations. They suffered from headache (43%), earache (38.3%), sense of fatigue (31.6%), sleep disturbance (29.5%), concentration difficulty (28.5%) and face burning sensation (19.2%). Both univariate and multivariate analysis were consistent in their findings. Symptomatic users were found to have significantly higher frequency of calls/day, longer call duration and longer total duration of mobile phone usage/day than non symptomatic users. For headache both call duration and frequency of calls/day were the significant predicting factors for its occurrence (chi2 = 18.208, p = 0.0001). For earache, in addition to call duration, the longer period of owning the mobile phone were significant predictors (chi2 = 16.996, p = 0.0002). Sense of fatigue was significantly affected by both call duration and age of the user

  20. Engineered nanomembranes for directing cellular organization toward flexible biodevices.

    PubMed

    Fujie, Toshinori; Ahadian, Samad; Liu, Hao; Chang, Haixin; Ostrovidov, Serge; Wu, Hongkai; Bae, Hojae; Nakajima, Ken; Kaji, Hirokazu; Khademhosseini, Ali

    2013-07-10

    Controlling the cellular microenvironment can be used to direct the cellular organization, thereby improving the function of synthetic tissues in biosensing, biorobotics, and regenerative medicine. In this study, we were inspired by the microstructure and biological properties of the extracellular matrix to develop freestanding ultrathin polymeric films (referred as "nanomembranes") that were flexible, cell adhesive, and had a morphologically tailorable surface. The resulting nanomembranes were exploited as flexible substrates on which cell-adhesive micropatterns were generated to align C2C12 skeletal myoblasts and embedded fibril carbon nanotubes enhanced the cellular elongation and differentiation. Functional nanomembranes with tunable morphology and mechanical properties hold great promise in studying cell-substrate interactions and in fabricating biomimetic constructs toward flexible biodevices. PMID:23758622

  1. A morphological investigation of sexual and lateral dimorphism in the developing metanephric kidney.

    PubMed

    Short, Kieran M; Smyth, Ian M

    2015-01-01

    Sexual dimorphism is a prominent feature of renal physiology and as a consequence, it differentially affects predisposition to many adult kidney diseases. Furthermore the left and right kidneys differ in terms of their position, size and involvement in congenital malformations of the urogenital tract. We set out to determine whether differences in the program of branching morphogenesis that establishes the basic architecture of the kidney were apparent with respect to either sex or laterality in mouse embryonic kidneys. This was achieved using a combination of optical projection tomography imaging and computational analysis of many spatial metrics describing the branched ureteric tree. We undertook a comprehensive assessment of twelve aspects of ureteric morphology across developmental time and we found no consistent differences between kidneys of different sexes or laterality. These results suggest that dimorphism is established after birth or at a physiological or cellular level that is not reflected in the morphology of the ureteric tree. PMID:26469293

  2. Drugs affecting glycosaminoglycan metabolism.

    PubMed

    Ghiselli, Giancarlo; Maccarana, Marco

    2016-07-01

    Glycosaminoglycans (GAGs) are charged polysaccharides ubiquitously present at the cell surface and in the extracellular matrix. GAGs are crucial for cellular homeostasis, and their metabolism is altered during pathological processes. However, little consideration has been given to the regulation of the GAG milieu through pharmacological interventions. In this review, we provide a classification of small molecules affecting GAG metabolism based on their mechanism of action. Furthermore, we present evidence to show that clinically approved drugs affect GAG metabolism and that this could contribute to their therapeutic benefit. PMID:27217160

  3. Control of cellular automata

    NASA Astrophysics Data System (ADS)

    Bagnoli, Franco; Rechtman, Raúl; El Yacoubi, Samira

    2012-12-01

    We study the problem of master-slave synchronization and control of totalistic cellular automata. The synchronization mechanism is that of setting a fraction of sites of the slave system equal to those of the master one (pinching synchronization). The synchronization observable is the distance between the two configurations. We present three control strategies that exploit local information (the number of nonzero first-order Boolean derivatives) in order to choose the sites to be synchronized. When no local information is used, we speak of simple pinching synchronization. We find the critical properties of control and discuss the best control strategy compared with simple synchronization.

  4. Cellular mechanics and motility

    NASA Astrophysics Data System (ADS)

    Hénon, Sylvie; Sykes, Cécile

    2015-10-01

    The term motility defines the movement of a living organism. One widely known example is the motility of sperm cells, or the one of flagellar bacteria. The propulsive element of such organisms is a cilium(or flagellum) that beats. Although cells in our tissues do not have a flagellum in general, they are still able to move, as we will discover in this chapter. In fact, in both cases of movement, with or without a flagellum, cell motility is due to a dynamic re-arrangement of polymers inside the cell. Let us first have a closer look at the propulsion mechanism in the case of a flagellum or a cilium, which is the best known, but also the simplest, and which will help us to define the hydrodynamic general conditions of cell movement. A flagellum is sustained by cellular polymers arranged in semi-flexible bundles and flagellar beating generates cell displacement. These polymers or filaments are part of the cellular skeleton, or "cytoskeleton", which is, in this case, external to the cellular main body of the organism. In fact, bacteria move in a hydrodynamic regime in which viscosity dominates over inertia. The system is thus in a hydrodynamic regime of low Reynolds number (Box 5.1), which is nearly exclusively the case in all cell movements. Bacteria and their propulsion mode by flagella beating are our unicellular ancestors 3.5 billion years ago. Since then, we have evolved to form pluricellular organisms. However, to keep the ability of displacement, to heal our wounds for example, our cells lost their flagellum, since it was not optimal in a dense cell environment: cells are too close to each other to leave enough space for the flagella to accomplish propulsion. The cytoskeleton thus developed inside the cell body to ensure cell shape changes and movement, and also mechanical strength within a tissue. The cytoskeleton of our cells, like the polymers or filaments that sustain the flagellum, is also composed of semi-flexible filaments arranged in bundles, and also in

  5. Morphological evolution of galaxies

    NASA Astrophysics Data System (ADS)

    Gardner, Jonathan P.; Heap, Sara R.; Malumuth, Eliot M.; Hill, Robert S.; Smith, Eric P.

    1997-05-01

    Recent studies of the Hubble Deep Field (Abraham et al. 1996) [1] and Medium Deep Survey (Driver, Windhorst & Griffiths 1995) [6] find that the frequency of irregular/peculiar/merger systems rises with increasing redshift. However, this finding must be carefully interpreted in light of UV images of low-redshift galaxies obtained by the Ultraviolet Imaging Telescope (Stecher et al. 1992) [9]. These UV images imply that K-correction effects may be at least partially responsible for the apparent increase in Irr galaxies with redshift. To assess the degree to which there is an overabundance of Irregular galaxies (relative to the present epoch), we must understand the degree to which the K-correction biases morphological studies. We demonstrate the importance of the morphological K-correction to the classification schemes used in the HDF. We find that high-redshift spiral galaxies are misclassified as Irr galaxies, while Elliptical/S0 galaxies, should not be affected substantially. We have been granted 40 orbits in Cycle 7 with STIS to place these conclusions on a statistical basis.

  6. Effects of Mechanical Properties on Tumor Invasion: Insights from a Cellular Model

    PubMed Central

    Li, Yingzi; Naveed, Hammad; Liang, Jie; Xu, Lisa X.

    2016-01-01

    Understanding the regulating mechanism of tumor invasion is of crucial importance for both fundamental cancer research and clinical applications. Previous in vivo experiments have shown that invasive cancer cells dissociate from the primary tumor and invade into the stroma, forming an irregular invasive morphology. Although cell movements involved in tumor invasion are ultimately driven by mechanical forces of cell-cell interactions and tumor-host interactions, how these mechanical properties affect tumor invasion is still poorly understood. In this study, we use a recently developed two-dimensional cellular model to study the effects of mechanical properties on tumor invasion. We study the effects of cell-cell adhesions as well as the degree of degradation and stiffness of extracellular matrix (ECM). Our simulation results show that cell-cell adhesion relationship must be satisfied for tumor invasion. Increased adhesion to ECM and decreased adhesion among tumor cells result in invasive tumor behaviors. When this invasive behavior occurs, ECM plays an important role for both tumor morphology and the shape of invasive cancer cells. Increased stiffness and stronger degree of degradation of ECM promote tumor invasion, generating more aggressive tumor invasive morphologies. It can also generate irregular shape of invasive cancer cells, protruding towards ECM. The capability of our model suggests it a useful tool to study tumor invasion and might be used to propose optimal treatment in clinical applications. PMID:25571562

  7. Mutations in the Borrelia burgdorferi Flagellar Type III Secretion System Genes fliH and fliI Profoundly Affect Spirochete Flagellar Assembly, Morphology, Motility, Structure, and Cell Division

    PubMed Central

    Gao, Lihui; Zhao, Xiaowei; Liu, Jun; Norris, Steven J.

    2015-01-01

    ABSTRACT The Lyme disease spirochete Borrelia burgdorferi migrates to distant sites in the tick vectors and mammalian hosts through robust motility and chemotaxis activities. FliH and FliI are two cytoplasmic proteins that play important roles in the type III secretion system (T3SS)-mediated export and assembly of flagellar structural proteins. However, detailed analyses of the roles of FliH and FliI in B. burgdorferi have not been reported. In this study, fliH and fliI transposon mutants were utilized to dissect the mechanism of the Borrelia type III secretion system. The fliH and fliI mutants exhibited rod-shaped or string-like morphology, greatly reduced motility, division defects (resulting in elongated organisms with incomplete division points), and noninfectivity in mice by needle inoculation. Mutants in fliH and fliI were incapable of translational motion in 1% methylcellulose or soft agar. Inactivation of either fliH or fliI resulted in the loss of the FliH-FliI complex from otherwise intact flagellar motors, as determined by cryo-electron tomography (cryo-ET). Flagellar assemblies were still present in the mutant cells, albeit in lower numbers than in wild-type cells and with truncated flagella. Genetic complementation of fliH and fliI mutants in trans restored their wild-type morphology, motility, and flagellar motor structure; however, full-length flagella and infectivity were not recovered in these complemented mutants. Based on these results, disruption of either fliH or fliI in B. burgdorferi results in a severe defect in flagellar structure and function and cell division but does not completely block the export and assembly of flagellar hook and filament proteins. PMID:25968649

  8. Self-generated morphology in lagoon reefs

    PubMed Central

    Hamblin, Michael G.

    2015-01-01

    The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia’s Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves—specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef. PMID:26175962

  9. Self-generated morphology in lagoon reefs.

    PubMed

    Blakeway, David; Hamblin, Michael G

    2015-01-01

    The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia's Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves-specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef. PMID:26175962

  10. Cellular Contraction and Polarization Drive Collective Cellular Motion.

    PubMed

    Notbohm, Jacob; Banerjee, Shiladitya; Utuje, Kazage J C; Gweon, Bomi; Jang, Hwanseok; Park, Yongdoo; Shin, Jennifer; Butler, James P; Fredberg, Jeffrey J; Marchetti, M Cristina

    2016-06-21

    Coordinated motions of close-packed multicellular systems typically generate cooperative packs, swirls, and clusters. These cooperative motions are driven by active cellular forces, but the physical nature of these forces and how they generate collective cellular motion remain poorly understood. Here, we study forces and motions in a confined epithelial monolayer and make two experimental observations: 1) the direction of local cellular motion deviates systematically from the direction of the local traction exerted by each cell upon its substrate; and 2) oscillating waves of cellular motion arise spontaneously. Based on these observations, we propose a theory that connects forces and motions using two internal state variables, one of which generates an effective cellular polarization, and the other, through contractile forces, an effective cellular inertia. In agreement with theoretical predictions, drugs that inhibit contractility reduce both the cellular effective elastic modulus and the frequency of oscillations. Together, theory and experiment provide evidence suggesting that collective cellular motion is driven by at least two internal variables that serve to sustain waves and to polarize local cellular traction in a direction that deviates systematically from local cellular velocity. PMID:27332131

  11. The effect of Freund's complete adjuvant on the cellular response in mice to sheep erythrocytes.

    PubMed Central

    Allan, D; Crampton, F I; Jenkins, P

    1975-01-01

    The effect of Freund's complete adjuvant on the cellular response in BALB/c mice to SRBC was studied using techniques based on immunocytoadherence (ICA), inhibition of ICA using an antiserum to the theta alloantigen, and immune adherence (IA). Particular attention was paid to the cellular morphology of the responding lymph nodes, details of which are described. Images Fig. 5 Fig. 6 PMID:1081922

  12. Unambiguous observation of shape effects on cellular fate of nanoparticles

    NASA Astrophysics Data System (ADS)

    Chu, Zhiqin; Zhang, Silu; Zhang, Bokai; Zhang, Chunyuan; Fang, Chia-Yi; Rehor, Ivan; Cigler, Petr; Chang, Huan-Cheng; Lin, Ge; Liu, Renbao; Li, Quan

    2014-03-01

    Cellular fate of nanoparticles is vital to application of nanoparticles to cell imaging, bio-sensing, drug delivery, suppression of drug resistance, gene delivery, and cytotoxicity analysis. However, the current studies on cellular fate of nanoparticles have been controversial due to complications of interplay between many possible factors. By well-controlled experiments, we demonstrated unambiguously that the morphology of nanoparticles independently determined their cellular fate. We found that nanoparticles with sharp shapes, regardless of their surface chemistry, size, or composition, could pierce the membranes of endosomes that carried them into the cells and escape to the cytoplasm, which in turn significantly reduced the cellular excretion rate of the nanoparticles. Such features of sharp-shaped nanoparticles are essential for drug delivery, gene delivery, subcellular targeting, and long-term tracking. This work opens up a controllable, purely geometrical and hence safe, degree of freedom for manipulating nanoparticle-cell interaction, with numerous applications in medicine, bio-imaging, and bio-sensing.

  13. Overexpression of p49/STRAP alters cellular cytoskeletal structure and gross anatomy in mice

    PubMed Central

    2014-01-01

    Background The protein p49/STRAP (SRFBP1) is a transcription cofactor of serum response factor (SRF) which regulates cytoskeletal and muscle-specific genes. Results Two conserved domains were found in the p49/STRAP protein. The SRF-binding domain was at its N-terminus and was highly conserved among mammalian species, xenopus and zebrafish. A BUD22 domain was found at its C-terminus in three sequence databases. The BUD22 domain was conserved among mammalian p49/STRAP proteins, and yeast cellular morphogenesis proteins, which is involved in ribosome biogenesis that affects growth rate and cell size. The endogenous p49/SRAP protein was localized mainly in the nucleus but also widely distributed in the cytoplasm, and was in close proximity to the actin. Transfected GFP-p49/STRAP protein co-localized with nucleolin within the nucleolus. Overexpression of p49/STRAP reduced actin content in cultured cells and resulted in smaller cell size versus control cells. Increased expression of p49/STRAP in transgenic mice resulted in newborns with malformations, which included asymmetric abdominal and thoracic cavities, and substantial changes in cardiac morphology. p49/STRAP altered the expression of certain muscle-specific genes, including that of the SRF gene, which is a key regulator of cardiac genes at the developmental, structural and maintenance level and has two SRE binding sites. Conclusions Since p49/STRAP is a co-factor of SRF, our data suggest that p49/STRAP likely regulates cell size and morphology through SRF target genes. The function of its BUD22 domain warrants further investigation. The observed increase in p49/STRAP expression during cellular aging may contribute to observed morphological changes in senescence. PMID:25183317

  14. Recent advances in morphological cell image analysis.

    PubMed

    Chen, Shengyong; Zhao, Mingzhu; Wu, Guang; Yao, Chunyan; Zhang, Jianwei

    2012-01-01

    This paper summarizes the recent advances in image processing methods for morphological cell analysis. The topic of morphological analysis has received much attention with the increasing demands in both bioinformatics and biomedical applications. Among many factors that affect the diagnosis of a disease, morphological cell analysis and statistics have made great contributions to results and effects for a doctor. Morphological cell analysis finds the cellar shape, cellar regularity, classification, statistics, diagnosis, and so forth. In the last 20 years, about 1000 publications have reported the use of morphological cell analysis in biomedical research. Relevant solutions encompass a rather wide application area, such as cell clumps segmentation, morphological characteristics extraction, 3D reconstruction, abnormal cells identification, and statistical analysis. These reports are summarized in this paper to enable easy referral to suitable methods for practical solutions. Representative contributions and future research trends are also addressed. PMID:22272215

  15. Engineering Cellular Metabolism.

    PubMed

    Nielsen, Jens; Keasling, Jay D

    2016-03-10

    Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds, and pharmaceuticals. However, making cells into efficient factories is challenging because cells have evolved robust metabolic networks with hard-wired, tightly regulated lines of communication between molecular pathways that resist efforts to divert resources. Here, we will review the current status and challenges of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation. PMID:26967285

  16. Effects of xenobiotics on fish tissues: morphological studies

    SciTech Connect

    Hawkes, J.W.

    1980-12-01

    Current applications of light and electron microscopy to investigations of changes in various tissues from fish exposed to xenobiotics have been reviewed. Emphasis has been placed on two types of contaminants, petroleum hydrocarbons and chlorobiphenyls, as examples of important xenobiotics found in the marine environment. Although the data are fragmentary because of the small number of studies, they clearly contribute new and valuable information to an understanding of the impact of these contaminants on the olfactory organ, liver, lens, and intestine from several species of fish. The morphological aspects of damage to the olfactory organs of fish exposed to petroleum hydrocarbons included hyperplasia and attenuation of the chemosensory cilia. In the liver of fish exposed to chlorobiphenyls, one of the most evident cellular anomalies was whorls of smooth endoplasmic reticulum. The rough endoplasmic reticulum appeared proliferated and its cisternae were dilated. Changes in the amount of lipid stored in the hepatocytes have been observed in fish exposed to both petroleum hydrocarbons and chlorobiphenyls. Some hydrocarbons affected eye tissues. Structural alterations that occurred during hydration of lens fiber cells and cataract formation were elucidated. A synopsis of the morphological changes in the intestine of fish exposed to petroleum hydrocarbons alone, chlorobiphenyls alone, and the combined contaminants is presented. All three groups of contaminant-exposed fish have subcellular inclusions that are distinctly abnormal. Recommendations for future studies include the need for further characterization of the range of normal tissue structure, comparative studies of additional species, and multiple contaminant exposures.

  17. Cellular Mechanisms Controlling Caspase Activation and Function

    PubMed Central

    Parrish, Amanda B.; Freel, Christopher D.; Kornbluth, Sally

    2013-01-01

    Caspases are the primary drivers of apoptotic cell death, cleaving cellular proteins that are critical for dismantling the dying cell. Initially translated as inactive zymogenic precursors, caspases are activated in response to a variety of cell death stimuli. In addition to factors required for their direct activation (e.g., dimerizing adaptor proteins in the case of initiator caspases that lie at the apex of apoptotic signaling cascades), caspases are regulated by a variety of cellular factors in a myriad of physiological and pathological settings. For example, caspases may be modified posttranslationally (e.g., by phosphorylation or ubiquitylation) or through interaction of modulatory factors with either the zymogenic or active form of a caspase, altering its activation and/or activity. These regulatory events may inhibit or enhance enzymatic activity or may affect activity toward particular cellular substrates. Finally, there is emerging literature to suggest that caspases can participate in a variety of cellular processes unrelated to apoptotic cell death. In these settings, it is particularly important that caspases are maintained under stringent control to avoid inadvertent cell death. It is likely that continued examination of these processes will reveal new mechanisms of caspase regulation with implications well beyond control of apoptotic cell death. PMID:23732469

  18. Conserved hippocampal cellular pathophysiology but distinct behavioural deficits in a new rat model of FXS.

    PubMed

    Till, Sally M; Asiminas, Antonis; Jackson, Adam D; Katsanevaki, Danai; Barnes, Stephanie A; Osterweil, Emily K; Bear, Mark F; Chattarji, Sumantra; Wood, Emma R; Wyllie, David J A; Kind, Peter C

    2015-11-01

    Recent advances in techniques for manipulating genomes have allowed the generation of transgenic animals other than mice. These new models enable cross-mammalian comparison of neurological disease from core cellular pathophysiology to circuit and behavioural endophenotypes. Moreover they will enable us to directly test whether common cellular dysfunction or behavioural outcomes of a genetic mutation are more conserved across species. Using a new rat model of Fragile X Syndrome, we report that Fmr1 knockout (KO) rats exhibit elevated basal protein synthesis and an increase in mGluR-dependent long-term depression in CA1 of the hippocampus that is independent of new protein synthesis. These defects in plasticity are accompanied by an increase in dendritic spine density selectively in apical dendrites and subtle changes in dendritic spine morphology of CA1 pyramidal neurons. Behaviourally, Fmr1 KO rats show deficits in hippocampal-dependent, but not hippocampal-independent, forms of associative recognition memory indicating that the loss of fragile X mental retardation protein (FMRP) causes defects in episodic-like memory. In contrast to previous reports from mice, Fmr1 KO rats show no deficits in spatial reference memory reversal learning. One-trial spatial learning in a delayed matching to place water maze task was also not affected by the loss of FMRP in rats. This is the first evidence for conservation across mammalian species of cellular and physiological hippocampal phenotypes associated with the loss of FMRP. Furthermore, while key cellular phenotypes are conserved they manifest in distinct behavioural dysfunction. Finally, our data reveal novel information about the selective role of FMRP in hippocampus-dependent associative memory. PMID:26243794

  19. Cellular basis of memory for addiction

    PubMed Central

    Nestler, Eric J.

    2013-01-01

    Despite the importance of numerous psychosocial factors, at its core, drug addiction involves a biological process: the ability of repeated exposure to a drug of abuse to induce changes in a vulnerable brain that drive the compulsive seeking and taking of drugs, and loss of control over drug use, that define a state of addiction. Here, we review the types of molecular and cellular adaptations that occur in specific brain regions to mediate addiction-associated behavioral abnormalities. These include alterations in gene expression achieved in part via epigenetic mechanisms, plasticity in the neurophysiological functioning of neurons and synapses, and associated plasticity in neuronal and synaptic morphology mediated in part by altered neurotrophic factor signaling. Each of these types of drug-induced modifications can be viewed as a form of “cellular or molecular memory.” Moreover, it is striking that most addiction-related forms of plasticity are very similar to the types of plasticity that have been associated with more classic forms of “behavioral memory,” perhaps reflecting the finite repertoire of adaptive mechanisms available to neurons when faced with environmental challenges. Finally, addiction-related molecular and cellular adaptations involve most of the same brain regions that mediate more classic forms of memory, consistent with the view that abnormal memories are important drivers of addiction syndromes. The goal of these studies which aim to explicate the molecular and cellular basis of drug addiction is to eventually develop biologically based diagnostic tests, as well as more effective treatments for addiction disorders. PMID:24459410

  20. Mitochondrial Morphology in Metabolic Diseases

    PubMed Central

    Galloway, Chad A.

    2013-01-01

    Abstract Significance: Mitochondria are the cellular energy-producing organelles and are at the crossroad of determining cell life and death. As such, the function of mitochondria has been intensely studied in metabolic disorders, including diabetes and associated maladies commonly grouped under all-inclusive pathological condition of metabolic syndrome. More recently, the altered metabolic profiles and function of mitochondria in these ailments have been correlated with their aberrant morphologies. This review describes an overview of mitochondrial fission and fusion machineries, and discusses implications of mitochondrial morphology and function in these metabolic maladies. Recent Advances: Mitochondria undergo frequent morphological changes, altering the mitochondrial network organization in response to environmental cues, termed mitochondrial dynamics. Mitochondrial fission and fusion mediate morphological plasticity of mitochondria and are controlled by membrane-remodeling mechanochemical enzymes and accessory proteins. Growing evidence suggests that mitochondrial dynamics play an important role in diabetes establishment and progression as well as associated ailments, including, but not limited to, metabolism–secretion coupling in the pancreas, nonalcoholic fatty liver disease progression, and diabetic cardiomyopathy. Critical Issues: While mitochondrial dynamics are intimately associated with mitochondrial bioenergetics, their cause-and-effect correlation remains undefined in metabolic diseases. Future Directions: The involvement of mitochondrial dynamics in metabolic diseases is in its relatively early stages. Elucidating the role of mitochondrial dynamics in pathological metabolic conditions will aid in defining the intricate form–function correlation of mitochondria in metabolic pathologies and should provide not only important clues to metabolic disease progression, but also new therapeutic targets. Antioxid. Redox Signal. 19, 415–430. PMID:22793999

  1. New structural and functional defects in polyphosphate deficient bacteria: A cellular and proteomic study

    PubMed Central

    2010-01-01

    Background Inorganic polyphosphate (polyP), a polymer of tens or hundreds of phosphate residues linked by ATP-like bonds, is found in all organisms and performs a wide variety of functions. PolyP is synthesized in bacterial cells by the actions of polyphosphate kinases (PPK1 and PPK2) and degraded by exopolyphosphatase (PPX). Bacterial cells with polyP deficiencies due to knocking out the ppk1 gene are affected in many structural and important cellular functions such as motility, quorum sensing, biofilm formation and virulence among others. The cause of this pleiotropy is not entirely understood. Results The overexpression of exopolyphosphatase in bacteria mimicked some pleitropic defects found in ppk1 mutants. By using this approach we found new structural and functional defects in the polyP-accumulating bacteria Pseudomonas sp. B4, which are most likely due to differences in the polyP-removal strategy. Colony morphology phenotype, lipopolysaccharide (LPS) structure changes and cellular division malfunction were observed. Finally, we used comparative proteomics in order to elucidate the cellular adjustments that occurred during polyP deficiency in this bacterium and found some clues that helped to understand the structural and functional defects observed. Conclusions The results obtained suggest that during polyP deficiency energy metabolism and particularly nucleoside triphosphate (NTP) formation were affected and that bacterial cells overcame this problem by increasing the flux of energy-generating metabolic pathways such as tricarboxilic acid (TCA) cycle, β-oxidation and oxidative phosphorylation and by reducing energy-consuming ones such as active transporters and amino acid biosynthesis. Furthermore, our results suggest that a general stress response also took place in the cell during polyP deficiency. PMID:20067623

  2. Cellular energy metabolism

    SciTech Connect

    Glaser, M.

    1991-06-01

    Studies have been carried out on adenylate kinase which is an important enzyme in determining the concentrations of the adenine nucleotides. An efficient method has been developed to clone mutant adenylate kinase genes in E. coli. Site-specific mutagenesis of the wild type gene also has been used to obtain forms of adenylate kinase with altered amino acids. The wild type and mutant forms of adenylate kinase have been overexpressed and large quantities were readily isolated. The kinetic and fluorescence properties of the different forms of adenylate kinase were characterized. This has led to a new model for the location of the AMP and ATP bindings sites on the enzyme and a proposal for the mechanism of substrate inhibition. Crystals of the wild type enzyme were obtained that diffract to at least 2.3 {angstrom} resolution. Experiments were also initiated to determine the function of adenylate kinase in vivo. In one set of experiments, E. coli strains with mutations in adenylate kinase showed large changes in cellular nucleotides after reaching the stationary phase in a low phosphate medium. This was caused by selective proteolytic degradation of the mutant adenylate kinase caused by phosphate starvation.

  3. Molecular and Cellular Biophysics

    NASA Astrophysics Data System (ADS)

    Jackson, Meyer B.

    2006-01-01

    Molecular and Cellular Biophysics provides advanced undergraduate and graduate students with a foundation in the basic concepts of biophysics. Students who have taken physical chemistry and calculus courses will find this book an accessible and valuable aid in learning how these concepts can be used in biological research. The text provides a rigorous treatment of the fundamental theories in biophysics and illustrates their application with examples. Conformational transitions of proteins are studied first using thermodynamics, and subsequently with kinetics. Allosteric theory is developed as the synthesis of conformational transitions and association reactions. Basic ideas of thermodynamics and kinetics are applied to topics such as protein folding, enzyme catalysis and ion channel permeation. These concepts are then used as the building blocks in a treatment of membrane excitability. Through these examples, students will gain an understanding of the general importance and broad applicability of biophysical principles to biological problems. Offers a unique synthesis of concepts across a wide range of biophysical topics Provides a rigorous theoretical treatment, alongside applications in biological systems Author has been teaching biophysics for nearly 25 years

  4. Electrosurgery with cellular precision.

    PubMed

    Palanker, Daniel V; Vankov, Alexander; Huie, Philip

    2008-02-01

    Electrosurgery, one of the most-often used surgical tools, is a robust but somewhat crude technology that has changed surprisingly little since its invention almost a century ago. Continuous radiofrequency is still used for tissue cutting, with thermal damage extending to hundreds of micrometers. In contrast, lasers developed 70 years later, have been constantly perfected, and the laser-tissue interactions explored in great detail, which has allowed tissue ablation with cellular precision in many laser applications. We discuss mechanisms of tissue damage by electric field, and demonstrate that electrosurgery with properly optimized waveforms and microelectrodes can rival many advanced lasers. Pulsed electric waveforms with burst durations ranging from 10 to 100 micros applied via insulated planar electrodes with 12 microm wide exposed edges produced plasma-mediated dissection of tissues with the collateral damage zone ranging from 2 to 10 microm. Length of the electrodes can vary from micrometers to centimeters and all types of soft tissues-from membranes to cartilage and skin could be dissected in liquid medium and in a dry field. This technology may allow for major improvements in outcomes of the current surgical procedures and development of much more refined surgical techniques. PMID:18270030

  5. Active Cellular Nematics

    NASA Astrophysics Data System (ADS)

    Duclos, Guillaume; Erlenkaemper, Christoph; Garcia, Simon; Yevick, Hannah; Joanny, Jean-François; Silberzan, Pascal; Biology inspired physics at mesoscales Team; Physical approach of biological problems Team

    We study the emergence of a nematic order in a two-dimensional tissue of apolar elongated fibroblast cells. Initially, these cells are very motile and the monolayer is characterized by giant density fluctuations, a signature of far-from-equilibrium systems. As the cell density increases because of proliferation, the cells align with each other forming large perfectly oriented domains while the cellular movements slow down and eventually freeze. Therefore topological defects characteristic of nematic phases remain trapped at long times, preventing the development of infinite domains. By analogy with classical non-active nematics, we have investigated the role of boundaries and we have shown that cells confined in stripes of width smaller than typically 500 µm are perfectly aligned in the stripe direction. Experiments performed in cross-shaped patterns show that both the number of cells and the degree of alignment impact the final orientation. Reference: Duclos G., Garcia S., Yevick H.G. and Silberzan P., ''Perfect nematic order in confined monolayers of spindle-shaped cells'', Soft Matter, 10, 14, 2014

  6. 47 CFR 22.909 - Cellular markets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Cellular markets. 22.909 Section 22.909... Cellular Radiotelephone Service § 22.909 Cellular markets. Cellular markets are standard geographic areas used by the FCC for administrative convenience in the licensing of cellular systems. Cellular...

  7. 47 CFR 22.909 - Cellular markets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Cellular markets. 22.909 Section 22.909... Cellular Radiotelephone Service § 22.909 Cellular markets. Cellular markets are standard geographic areas used by the FCC for administrative convenience in the licensing of cellular systems. Cellular...

  8. Cellular Structure Pattern in Dielectric Barrier Discharge

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Dong, Lifang; Liu, Weibo; Gao, Xing; Wei, Lingyan

    2015-12-01

    We report the observation of a cellular structure pattern in a dielectric barrier discharge system. The evolution sequence and phase diagram of the pattern are given. It is firstly observed that the "cell nucleus" fire three or even more times at a fixed location at the rising edge of the applied voltage, and that the "cell walls" which have the same discharge times with the "cell nucleus" are ignited slightly after the "cell nucleus". By observing a series of frames recorded by a high speed video camera, it is found that the cellular structure pattern consists of volume discharges (VDs) and surface discharges (SDs) corresponding to the "cell nucleus" and "cell walls" respectively. That VDs and SDs are ignited in turn for several times in each half cycle of the applied voltage confirms the fact that VDs induce the SDs and SDs also affect the following VDs.

  9. Klotho-Dependent Cellular Transport Regulation.

    PubMed

    Sopjani, M; Dërmaku-Sopjani, M

    2016-01-01

    Klotho is a transmembrane protein that in humans is encoded by the hKL gene. This protein is known to have aging suppressor effects and is predominantly expressed in the distal convoluted tubule of the kidney, parathyroid glands, and choroid plexus of the brain. The Klotho protein exists in both full-length membrane form and a soluble secreted form, which exerts numerous distinct functions. The extracellular domain of Klotho can be enzymatically cleaved off and released into the systemic circulation where it functions as β-glucuronidase and a hormone. Soluble Klotho is a multifunction protein present in the biological fluids including blood, urine, and cerebrospinal fluid of mammals. Klotho deficiency leads to multiple organ failure accompanied by early appearance of multiple age-related disorders and early death, whereas overexpression of Klotho results in the opposite effects. Klotho, an enzyme and hormone, has been reported to participate in the regulation of cellular transport processes across the plasma membrane either indirectly through inhibiting calcitriol (1,25(OH)2D3) formation or other mechanism, or by directly affecting transporter proteins, including ion channels, cellular carriers, and Na(+)/K(+)-ATPase. Accordingly, Klotho protein serves as a powerful regulator of cellular transport across the plasma membrane. Importantly, Klotho-dependent cellular transport regulation implies stimulatory or inhibitory effects. Klotho has been shown to play a key role in the regulation of multiple calcium and potassium ion channels, and various cellular carriers including the Na(+)-coupled cotransporters such as NaPi-IIa, NaPi-IIb, EAAT3, and EAAT4, CreaT1 as well as Na(+)/K(+)-ATPase. These regulations are parts of the antiaging function of Klotho, which will be discussing throughout this chapter. Clearly, further experimental efforts are required to investigate the effect of Klotho on other transport proteins and underlying molecular mechanisms by which Klotho

  10. Valleywide patterns of posteruption erosion and deposition in the South Fork Toutle River, Washington—evidence of valley morphology and hillslope-channel coupling affecting sediment supply, storage, and delivery

    NASA Astrophysics Data System (ADS)

    Major, J. J.; Mark, L.

    2009-12-01

    Following the May 1980 eruption of Mount St. Helens, greatly elevated sediment loads issued from river valleys heavily impacted by the eruption. The extraordinary sediment loads resulted chiefly from erosion of thick deposits of fresh volcanic sediment. Within 5 years of the eruption, loads from some basins returned to pre-eruption levels, whereas in others they remain elevated after nearly 3 decades. In the South Fork Toutle (SFT) River basin on the volcano’s west flank, sediment loads remain highly variable and commonly are equivalent to or exceed those measured in the early 1980s. To gain insights on the sources of the sediment loads, their longevity, and the causes of their anomalously high variability compared to neighboring basins, we examined vertical topographic changes among a time-series of digital elevation models (DEMs; RMSE ˜3m) made from aerial photographs and lidar of the 50-km-long valley. The DEMs represent posteruption conditions in June 1980, 2000, and 2003. Our examination reveals patterns of erosion and deposition that appear to be controlled by valley morphology and hillslope-channel coupling. Between 1980 and 2000, erosion and deposition were focused in alternating reach-scale hotspots (˜3 km long). Within 15 km of the summit, long-term net channel deposition predominated, but sandwiched a 3-km-long reach of intense erosion. Net deposition proximal to the volcano was likely the result of persistent sediment influx from the high, steep flanks of the volcano, composed of unconsolidated, readily erodible sediment prone to mass wasting. Reach-scale deposition downstream of reach-scale erosion occurred in reaches of valley expansion, in valley embayments, and where channels abutted steep hillslopes. In the valley’s distal 10 km, where the channel is less directly connected to hillslopes, where hillslope sediment sources capable of channel replenishment are more limited, and where sediment removal outpaced upstream sediment input, long

  11. Cellular senescence: when bad things happen to good cells.

    PubMed

    Campisi, Judith; d'Adda di Fagagna, Fabrizio

    2007-09-01

    Cells continually experience stress and damage from exogenous and endogenous sources, and their responses range from complete recovery to cell death. Proliferating cells can initiate an additional response by adopting a state of permanent cell-cycle arrest that is termed cellular senescence. Understanding the causes and consequences of cellular senescence has provided novel insights into how cells react to stress, especially genotoxic stress, and how this cellular response can affect complex organismal processes such as the development of cancer and ageing. PMID:17667954

  12. On Patterns in Affective Media

    NASA Astrophysics Data System (ADS)

    ADAMATZKY, ANDREW

    In computational experiments with cellular automaton models of affective solutions, where chemical species represent happiness, anger, fear, confusion and sadness, we study phenomena of space time dynamic of emotions. We demonstrate feasibility of the affective solution paradigm in example of emotional abuse therapy. Results outlined in the present paper offer unconventional but promising technique to design, analyze and interpret spatio-temporal dynamic of mass moods in crowds.

  13. Perfect cellular eutectic growth in directionally solidified NiAl-Cr(Mo) hypereutectic alloy

    NASA Astrophysics Data System (ADS)

    Shang, Zhao; Shen, Jun; Zhang, Jianfei; Wang, Lei; Fu, Hengzhi

    2012-09-01

    Cellular eutectic microstructures with fully lamellar morphology were observed in the directionally solidified Ni-31Al-32Cr-6Mo (at%) hypereutectic alloy at withdrawal rates of 15, 25 and 50 μm/s, but the morphologies of cellular microstructures did not change consecutively with increasing withdrawal rate. The growth interfaces were deep cellular at withdrawal rates of 15 and 50 μm/s, but it changed to be shallow cellular at rate of 25 μm/s. The reason is that the interface undercooling comes to minimum at the middle rate of 25 μm/s. If the interface undercooling decreases, the tendency of constitutional undercooling will be weaken. The small constitutional undercooling will increase the interface stability, so that the interface morphology changes from deep cellular to shallow cellular. The shallow cellular growth interface led to a perfect cellular eutectic microstructure, which was analogous to the planar eutectic microstructure. In this case, the widths of the intercellular regions were narrowest, no coarse or irregular plates existed at the cell boundaries, and the thicknesses of the lamellae were almost uniform. The properties of the alloy may be markedly improved.

  14. MSAT and cellular hybrid networking

    NASA Technical Reports Server (NTRS)

    Baranowsky, Patrick W., II

    1993-01-01

    Westinghouse Electric Corporation is developing both the Communications Ground Segment and the Series 1000 Mobile Phone for American Mobile Satellite Corporation's (AMSC's) Mobile Satellite (MSAT) system. The success of the voice services portion of this system depends, to some extent, upon the interoperability of the cellular network and the satellite communication circuit switched communication channels. This paper will describe the set of user-selectable cellular interoperable modes (cellular first/satellite second, etc.) provided by the Mobile Phone and described how they are implemented with the ground segment. Topics including roaming registration and cellular-to-satellite 'seamless' call handoff will be discussed, along with the relevant Interim Standard IS-41 Revision B Cellular Radiotelecommunications Intersystem Operations and IOS-553 Mobile Station - Land Station Compatibility Specification.

  15. Morphological remodeling of C. elegans neurons during aging is modified by compromised protein homeostasis

    PubMed Central

    Vayndorf, Elena M; Scerbak, Courtney; Hunter, Skyler; Neuswanger, Jason R; Toth, Marton; Parker, J Alex; Neri, Christian; Driscoll, Monica; Taylor, Barbara E

    2016-01-01

    Understanding cellular outcomes, such as neuronal remodeling, that are common to both healthy and diseased aging brains is essential to the development of successful brain aging strategies. Here, we used Caenorhabdits elegans to investigate how the expression of proteotoxic triggers, such as polyglutamine (polyQ)-expanded huntingtin and silencing of proteostasis regulators, such as the ubiquitin–proteasome system (UPS) and protein clearance components, may impact the morphological remodeling of individual neurons as animals age. We examined the effects of disrupted proteostasis on the integrity of neuronal cytoarchitecture by imaging a transgenic C. elegans strain in which touch receptor neurons express the first 57 amino acids of the human huntingtin (Htt) gene with expanded polyQs (128Q) and by using neuron-targeted RNA interference in adult wild-type neurons to knockdown genes encoding proteins involved in proteostasis. We found that proteostatic challenges conferred by polyQ-expanded Htt and knockdown of specific genes involved in protein homeostasis can lead to morphological changes that are restricted to specific domains of specific neurons. The age-associated branching of PLM neurons is suppressed by N-ter polyQ-expanded Htt expression, whereas ALM neurons with polyQ-expanded Htt accumulate extended outgrowths and other soma abnormalities. Furthermore, knockdown of genes important for ubiquitin-mediated degradation, lysosomal function, and autophagy modulated these age-related morphological changes in otherwise normal neurons. Our results show that the expression of misfolded proteins in neurodegenerative disease such as Huntington’s disease modifies the morphological remodeling that is normally associated with neuronal aging. Our results also show that morphological remodeling of healthy neurons during aging can be regulated by the UPS and other proteostasis pathways. Collectively, our data highlight a model in which morphological remodeling during

  16. ALS/FTLD-linked TDP-43 regulates neurite morphology and cell survival in differentiated neurons

    SciTech Connect

    Han, Jeong-Ho; Yu, Tae-Hoon; Ryu, Hyun-Hee; Jun, Mi-Hee; Ban, Byung-Kwan; Jang, Deok-Jin; Lee, Jin-A

    2013-08-01

    Tar-DNA binding protein of 43 kDa (TDP-43) has been characterized as a major component of protein aggregates in brains with neurodegenerative diseases such as frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). However, physiological roles of TDP-43 and early cellular pathogenic effects caused by disease associated mutations in differentiated neurons are still largely unknown. Here, we investigated the physiological roles of TDP-43 and the effects of missense mutations associated with diseases in differentiated cortical neurons. The reduction of TDP-43 by siRNA increased abnormal neurites and decreased cell viability. ALS/FTLD-associated missense mutant proteins (A315T, Q331K, and M337V) were partially mislocalized to the cytosol and neurites when compared to wild-type and showed abnormal neurites similar to those observed in cases of loss of TDP-43. Interestingly, cytosolic expression of wild-type TDP-43 with mutated nuclear localization signals also induced abnormal neurtie morphology and reduction of cell viability. However, there was no significant difference in the effects of cytosolic expression in neuronal morphology and cell toxicity between wild-type and missense mutant proteins. Thus, our results suggest that mislocalization of missense mutant TDP-43 may contribute to loss of TDP-43 function and affect neuronal morphology, probably via dominant negative action before severe neurodegeneration in differentiated cortical neurons. Highlights: • The function of nuclear TDP-43 in neurite morphology in mature neurons. • Partial mislocalization of TDP-43 missense mutants into cytosol from nucleus. • Abnormal neurite morphology caused by missense mutants of TDP-43. • The effect of cytosolic expression of TDP-43 in neurite morphology and in cell survival.

  17. Culturing Cells in 3D Ordered Cellular Solids

    NASA Astrophysics Data System (ADS)

    Lin, Keng-Hui; Lin, Wang-Jung; Lin, Jing-Ying

    2011-03-01

    Constructing a well-defined 3D microenvironment for cell growth is a key step for tissue engineering and mechanobiology. We demonstrate high-throughput fabrication of gelatin-based ordered cellular solids with tunable pore size and solid fraction. This process involves generating monodisperse liquid foam with a cross-flow microfluidic device. The monodisperse liquid foam was further processed into open-cell solid foam, which was used as scaffolds for 3D cell culture. Three distinct cell types were cultured under these conditions and displayed appropriate physiological, morphological, and functional characteristics. Epithelial cells formed cyst-like structures and were polarized inside pores, myoblasts adopted a tubular structure and fused into myotubes, and fibroblasts exhibited wide varieties of morphologies depending on their location inside the scaffolds. These ordered cellular solids therefore make possible the study of pore-size effects on cells.

  18. Heat and phosphate starvation effects on the proteome, morphology and chemical composition of the biomining bacteria Acidithiobacillus ferrooxidans.

    PubMed

    Ribeiro, Daniela A; Maretto, Danilo A; Nogueira, Fábio C S; Silva, Márcio J; Campos, Francisco A P; Domont, Gilberto B; Poppi, Ronei J; Ottoboni, Laura M M

    2011-06-01

    Acidithiobacillus ferrooxidans is a Gram negative, acidophilic, chemolithoautotrophic bacterium that plays an important role in metal bioleaching. During bioleaching, the cells are subjected to changes in the growth temperature and nutrients starvation. The aim of this study was to gather information about the response of the A.ferrooxidans Brazilian strain LR to K2HPO4 starvation and heat stress through investigation of cellular morphology, chemical composition and differential proteome. The scanning electron microscopic results showed that under the tested stress conditions, A. ferrooxidans cells became elongated while the Fourier transform infrared spectroscopy (FT-IR) analysis showed alterations in the wavenumbers between 850 and 1,275 cm(-1), which are related to carbohydrates, phospholipids and phosphoproteins. These findings indicate that the bacterial cell surface is affected by the tested stress conditions. A proteomic analysis, using 2-DE and tandem mass spectrometry, enabled the identification of 44 differentially expressed protein spots, being 30 due to heat stress (40°C) and 14 due to K2HPO4 starvation. The identified proteins belonged to 11 different functional categories, including protein fate, energy metabolism and cellular processes. The upregulated proteins were mainly from protein fate and energy metabolism categories. The obtained results provide evidences that A. ferrooxidans LR responds to heat stress and K2HPO4 starvation by inducing alterations in cellular morphology and chemical composition of the cell surface. Also, the identification of several proteins involved in protein fate suggests that the bacteria cellular homesostasis was affected. In addition, the identification of proteins from different functional categories indicates that the A. ferrooxidans response to higher than optimal temperatures and phosphate starvation involves global changes in its physiology. PMID:25187146

  19. Leucocyte cellular adhesion molecules.

    PubMed

    Yong, K; Khwaja, A

    1990-12-01

    Leucocytes express adhesion promoting receptors which mediate cell-cell and cell-matrix interactions. These adhesive interactions are crucial to the regulation of haemopoiesis and thymocyte maturation, the direction and control of leucocyte traffic and migration through tissues, and in the development of immune and non-immune inflammatory responses. Several families of adhesion receptors have been identified (Table). The leucocyte integrin family comprises 3 alpha beta heterodimeric membrane glycoproteins which share a common beta subunit, designated CD18. The alpha subunits of each of the 3 members, lymphocyte function associated antigen-1 (LFA-1), macrophage antigen-1 (Mac-1) and p150,95 are designated CD11a, b and c respectively. These adhesion molecules play a critical part in the immune and inflammatory responses of leucocytes. The leucocyte integrin family is, in turn, part of the integrin superfamily, members of which are evolutionally, structurally and functionally related. Another Integrin subfamily found on leucocytes is the VLA group, so-called because the 'very late activation antigens' VLA-1 and VLA-2 were originally found to appear late in T-cell activation. Members of this family function mainly as extracellular matrix adhesion receptors and are found both on haemopoietic and non-haemopoietic cells. They play a part in diverse cellular functions including tissue organisation, lymphocyte recirculation and T-cell immune responses. A third integrin subfamily, the cytoadhesins, are receptors on platelets and endothelial cells which bind extracellular matrix proteins. A second family of adhesion receptors is the immunoglobulin superfamily, members of which include CD2, LFA-3 and ICAM-1, which participate in T-cell adhesive interactions, and the antigen-specific receptors of T and B cells, CD4, CD8 and the MHC Class I and II molecules. A recently recognised family of adhesion receptors is the selectins, characterised by a common lectin domain. Leucocyte

  20. The sertolian epithelium in the testis of men affected by 'Sertoli-cell-only syndrome'.

    PubMed

    Tedde, G; Montella, A; Fiocca, D; Delrio, A N

    1993-01-01

    Because of the architectural complexity of the seminiferous epithelium, the Sertoli cell is extremely difficult to study. The individual cellular constituents of the tubular wall are intimately associated with one another; especially Sertoli cells and germinal cells are tightly connected. As implied by the name, Sertoli-cell-only syndrome (SCOS) is characterized by the presence of only Sertoli cells in the seminiferous tubule. The absence of germinal cells makes this condition ideal for the morphological study of Sertoli cell. Testicular biopsy specimens of subjects affected by SCOS were studied under light and electron microscopy. The Sertoli cells appeared to be morphologically normal, except for their shape, that appears to be columnar as result of the complete absence of the germinal cells. The cellular outlines were irregular, particularly at the base, but the cytoplasm contained normal organelles and inclusions. The presence of both pale and dark elements was evident. These differences in staining reflect the variability in concentration of glycogen particles and intermediate microfilaments in the cytoplasm. In spite of these differences between Sertoli cells in SCOS and those in normal subjects, SCOS represents a satisfactory model for the morphological and functional analysis of the Sertoli cells. PMID:7694556

  1. Morphological and Physiological Characterization of Listeria monocytogenes Subjected to High Hydrostatic Pressure

    PubMed Central

    Ritz, M.; Tholozan, J. L.; Federighi, M.; Pilet, M. F.

    2001-01-01

    High hydrostatic pressure is a new food preservation technology known for its capacity to inactivate spoilage and pathogenic microorganisms. That inactivation is usually assessed by the number of colonies growing on solid media after treatment. Under normal conditions the method does not permit recovery of damaged cells and may underestimate the number of cells that will remain viable and grow after a few days in high-pressure-processed foodstuffs. This study investigated the damage inflicted on Listeria monocytogenes cells treated by high pressure for 10 min at 400 MPa in pH 5.6 citrate buffer. Under these conditions, no cell growth occurred after 48 h on plate count agar. Scanning electron microscopy, light scattering by flow cytometry, and cell volume measurements were compared to evaluate the morphological changes in cells after pressurization. All these methods revealed that cellular morphology was not really affected. Esterase activity, as assessed either by enzymatic activity assays or by carboxy fluorescein diacetate fluorescence monitored by flow cytometry, was dramatically lowered, but not totally obliterated, under the effects of treatment. The measurement of propidium iodide uptake followed by flow cytometry demonstrated that membrane integrity was preserved in a small part of the population, although the membrane potential measured by analytical methods or evaluated by oxonol uptake was reduced from −86 to −5 mV. These results showed that such combined methods as fluorescent dyes monitored by flow cytometry and physiological activity measurements provide valuable indications of cellular viability. PMID:11319107

  2. Effect of cellular mobility on immune response

    NASA Astrophysics Data System (ADS)

    Pandey, R. B.; Mannion, R.; Ruskin, H. J.

    2000-08-01

    Mobility of cell types in our HIV immune response model is subject to an intrinsic mobility and an explicit directed mobility, which is governed by Pmob. We investigate how restricting the explicit mobility, while maintaining the innate mobility of a viral-infected cell, affects the model's results. We find that increasing the explicit mobility of the immune system cells leads to viral dominance for certain levels of viral mutation. We conclude that increasing immune system cellular mobility indirectly increases the virus’ inherent mobility.

  3. Three-dimensional morphogenesis of MDCK cells induced by cellular contractile forces on a viscous substrate.

    PubMed

    Imai, Misako; Furusawa, Kazuya; Mizutani, Takeomi; Kawabata, Kazushige; Haga, Hisashi

    2015-01-01

    Substrate physical properties are essential for many physiological events such as embryonic development and 3D tissue formation. Physical properties of the extracellular matrix such as viscoelasticity and geometrical constraints are understood as factors that affect cell behaviour. In this study, we focused on the relationship between epithelial cell 3D morphogenesis and the substrate viscosity. We observed that Madin-Darby Canine Kidney (MDCK) cells formed 3D structures on a viscous substrate (Matrigel). The structures appear as a tulip hat. We then changed the substrate viscosity by genipin (GP) treatment. GP is a cross-linker of amino groups. Cells cultured on GP-treated-matrigel changed their 3D morphology in a substrate viscosity-dependent manner. Furthermore, to elucidate the spatial distribution of the cellular contractile force, localization of mono-phosphorylated and di-phosphorylated myosin regulatory light chain (P-MRLCs) was visualized by immunofluorescence. P-MRLCs localized along the periphery of epithelial sheets. Treatment with Y-27632, a Rho-kinase inhibitor, blocked the P-MRLCs localization at the edge of epithelial sheets and halted 3D morphogenesis. Our results indicate that the substrate viscosity, the substrate deformation, and the cellular contractile forces induced by P-MRLCs play crucial roles in 3D morphogenesis. PMID:26374384

  4. Physical principles of genomic regulation through cellular nanoscale structure and implications for initiation of carcinogenesis

    NASA Astrophysics Data System (ADS)

    Backman, Vadim

    2011-03-01

    Although compelling evidence suggests that cellular nanoarchitecture and nanoscale environment where molecular interactions take place would be expected to significantly affect macromolecular processes, biological ramifications of cellular nanoscale organization have been largely unexplored. This understanding has been hampered in part by the diffraction limited resolution of optical microscopy. The talk will discuss a novel optical microscopy technique, partial wave spectroscopic (PWS) microscopy, that is capable of quantifying statistical properties of cell structure at the nanoscale. Animal and human studies demonstrated that an alteration in the statistical properties of the nanoscale mass density distribution in the cell nucleus (e.g. nuclear nanoarchitecture) is one of the earliest and ubiquitous events in carcinogenesis and precedes any other known morphological changes at larger length scales (e.g. microarchitecture). The talk will also discuss the physical principles of how the alteration in nuclear nanoarchitecture may modulate genomic processes and, in particular, gene transcription. Work done in collaboration with Hariharan Subramanian, Prabhakar Pradhan, Dhwanil Damania, Lusik Cherkezyan, Yolanda Stypula, Jun Soo Kim, Igal Szleifer, Northwestern University, Evanston, IL, Hemant K. Roy, Northshore University HealthSystems, Evanston, IL

  5. Morphological diversity of Paramoeba perurans trophozoites and their interaction with Atlantic salmon, Salmo salar L., gills.

    PubMed

    Wiik-Nielsen, J; Mo, T A; Kolstad, H; Mohammad, S N; Hytterød, S; Powell, M D

    2016-09-01

    Amoebic gill disease (AGD) caused by the ectoparasite Paramoeba perurans affects several cultured marine fish species worldwide. In this study, the morphology and ultrastructure of P. perurans in vitro and in vivo was investigated using scanning and transmission electron microscopy (SEM and TEM, respectively). Amoebae cultures contained several different morphologies ranging from a distinct rounded cell structure and polymorphic cells with pseudopodia of different lengths and shapes. SEM studies of the gills of AGD-affected Atlantic salmon, Salmo salar L., revealed the presence of enlarged swellings in affected gill filaments and fusion of adjacent lamellae. Spherical amoebae appeared to embed within the epithelium, and subsequently leave hemispherical indentations with visible fenestrations in the basolateral surface following their departure. These fenestrated structures corresponded to the presence of pseudopodia which could be seen by TEM to penetrate into the epithelium. The membrane-membrane interface contained an amorphous and slightly fibrous matrix. This suggests the existence of cellular glycocalyces and a role for extracellular products in mediating pathological changes in amoebic gill disease. PMID:26775899

  6. A Giant Vulvar Mass: A Case Study of Cellular Angiofibroma

    PubMed Central

    Aydın, Ümit; Terzi, Hasan; Turkay, Ünal; Eruyar, Ahmet Tuğrul; Kale, Ahmet

    2016-01-01

    Cellular angiofibroma is a mesenchymal tumor that affects both genders. Nucci et al. first described it in 1997. Cellular angiofibroma is generally a small and asymptomatic mass that primarily arises in the vulvar-vaginal region, although rare cases have been reported in the pelvic and extrapelvic regions. It affects women most often during the fifth decade of life. The treatment requires simple local excision due to low local recurrence and no chance of metastasization. The current study presents a case of angiofibroma in the vulvar region that measured approximately 20 cm. PMID:27293929

  7. Cellular compartmentalization of secondary metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors sh...

  8. Cellular therapy for haematological malignancies.

    PubMed

    Roddie, P H; Turner, M L

    2002-11-01

    The aim of this review was to summarize the recent progress made in the field of cellular therapeutics in haematological malignancy. The review also examined the role that the National Transfusion Services might play in the manufacture of new cellular therapeutic agents, given both their expertise in the safe provision of blood products and their possession of accredited cell manipulation facilities. Cellular therapy is entering an era in which novel cellular products will find increasing clinical use, particularly in the areas of haematopoietic stem cell transplantation and immunotherapy. The production of novel cell-based therapies, both in Europe and North America, is now under strict regulatory control and therefore collaboration with the National Transfusion Services in the manufacture of these agents may well be beneficial if the production standards demanded by the regulatory authorities are to be fulfilled. PMID:12437515

  9. Mathematical Modeling of Cellular Metabolism.

    PubMed

    Berndt, Nikolaus; Holzhütter, Hermann-Georg

    2016-01-01

    Cellular metabolism basically consists of the conversion of chemical compounds taken up from the extracellular environment into energy (conserved in energy-rich bonds of organic phosphates) and a wide array of organic molecules serving as catalysts (enzymes), information carriers (nucleic acids), and building blocks for cellular structures such as membranes or ribosomes. Metabolic modeling aims at the construction of mathematical representations of the cellular metabolism that can be used to calculate the concentration of cellular molecules and the rates of their mutual chemical interconversion in response to varying external conditions as, for example, hormonal stimuli or supply of essential nutrients. Based on such calculations, it is possible to quantify complex cellular functions as cellular growth, detoxification of drugs and xenobiotic compounds or synthesis of exported molecules. Depending on the specific questions to metabolism addressed, the methodological expertise of the researcher, and available experimental information, different conceptual frameworks have been established, allowing the usage of computational methods to condense experimental information from various layers of organization into (self-) consistent models. Here, we briefly outline the main conceptual frameworks that are currently exploited in metabolism research. PMID:27557541

  10. Effects of nanosecond pulse electric fields on cellular elasticity.

    PubMed

    Dutta, Diganta; Asmar, Anthony; Stacey, Michael

    2015-05-01

    We investigated the effects of a single 60 nanosecond pulsed electric field (nsPEF) of low (15 kV/cm) and high (60 kV/cm) field strengths on cellular morphology and membrane elasticity in Jurkat cells using fluorescent microscopy and atomic force microscopy (AFM). We performed force displacement measurements on cells using AFM and calculated the Young's modulus for membrane elasticity. Differential effects were observed depending upon pulsing conditions. We found that a single nsPEF of low field strength did not induce any apparent cytoskeletal breakdown and had minor morphological changes. Interestingly, force measurements and calculation of Young's modulus showed a significant decrease in membrane elasticity. A single nsPEF of high field strength induced stark morphological changes due to disruption of the actin cytoskeleton and a marked decrease in elasticity likely caused by irreversible membrane damage. We suggest that the cellular morphology is mainly dependent on stabilization by the actin cytoskeleton, while the elasticity changes are partially dependent on the cytoskeletal integrity. PMID:25732004

  11. Protection after stroke: cellular effectors of neurovascular unit integrity

    PubMed Central

    Posada-Duque, Rafael Andres; Barreto, George E.; Cardona-Gomez, Gloria Patricia

    2014-01-01

    Neurological disorders are prevalent worldwide. Cerebrovascular diseases (CVDs), which account for 55% of all neurological diseases, are the leading cause of permanent disability, cognitive and motor disorders and dementia. Stroke affects the function and structure of blood-brain barrier, the loss of cerebral blood flow regulation, oxidative stress, inflammation and the loss of neural connections. Currently, no gold standard treatments are available outside the acute therapeutic window to improve outcome in stroke patients. Some promising candidate targets have been identified for the improvement of long-term recovery after stroke, such as Rho GTPases, cell adhesion proteins, kinases, and phosphatases. Previous studies by our lab indicated that Rho GTPases (Rac and RhoA) are involved in both tissue damage and survival, as these proteins are essential for the morphology and movement of neurons, astrocytes and endothelial cells, thus playing a critical role in the balance between cell survival and death. Treatment with a pharmacological inhibitor of RhoA/ROCK blocks the activation of the neurodegeneration cascade. In addition, Rac and synaptic adhesion proteins (p120 catenin and N-catenin) play critical roles in protection against cerebral infarction and in recovery by supporting the neurovascular unit and cytoskeletal remodeling activity to maintain the integrity of the brain parenchyma. Interestingly, neuroprotective agents, such as atorvastatin, and CDK5 silencing after cerebral ischemia and in a glutamate-induced excitotoxicity model may act on the same cellular effectors to recover neurovascular unit integrity. Therefore, future efforts must focus on individually targeting the structural and functional roles of each effector of neurovascular unit and the interactions in neural and non-neural cells in the post-ischemic brain and address how to promote the recovery or prevent the loss of homeostasis in the short, medium and long term. PMID:25177270

  12. Evolution of cellular morpho-phenotypes in cancer metastasis.

    PubMed

    Wu, Pei-Hsun; Phillip, Jude M; Khatau, Shyam B; Chen, Wei-Chiang; Stirman, Jeffrey; Rosseel, Sophie; Tschudi, Katherine; Van Patten, Joshua; Wong, Michael; Gupta, Sonal; Baras, Alexander S; Leek, Jeffrey T; Maitra, Anirban; Wirtz, Denis

    2015-01-01

    Intratumoral heterogeneity greatly complicates the study of molecular mechanisms driving cancer progression and our ability to predict patient outcomes. Here we have developed an automated high-throughput cell-imaging platform (htCIP) that allows us to extract high-content information about individual cells, including cell morphology, molecular content and local cell density at single-cell resolution. We further develop a comprehensive visually-aided morpho-phenotyping recognition (VAMPIRE) tool to analyze irregular cellular and nuclear shapes in both 2D and 3D microenvironments. VAMPIRE analysis of ~39,000 cells from 13 previously sequenced patient-derived pancreatic cancer samples indicate that metastasized cells present significantly lower heterogeneity than primary tumor cells. We found the same morphological signature for metastasis for a cohort of 10 breast cancer cell lines. We further decipher the relative contributions to heterogeneity from cell cycle, cell-cell contact, cell stochasticity and heritable morphological variations. PMID:26675084

  13. Evolution of cellular morpho-phenotypes in cancer metastasis

    PubMed Central

    Wu, Pei-Hsun; Phillip, Jude M.; Khatau, Shyam B.; Chen, Wei-Chiang; Stirman, Jeffrey; Rosseel, Sophie; Tschudi, Katherine; Van Patten, Joshua; Wong, Michael; Gupta, Sonal; Baras, Alexander S.; Leek, Jeffrey T.; Maitra, Anirban; Wirtz, Denis

    2015-01-01

    Intratumoral heterogeneity greatly complicates the study of molecular mechanisms driving cancer progression and our ability to predict patient outcomes. Here we have developed an automated high-throughput cell-imaging platform (htCIP) that allows us to extract high-content information about individual cells, including cell morphology, molecular content and local cell density at single-cell resolution. We further develop a comprehensive visually-aided morpho-phenotyping recognition (VAMPIRE) tool to analyze irregular cellular and nuclear shapes in both 2D and 3D microenvironments. VAMPIRE analysis of ~39,000 cells from 13 previously sequenced patient-derived pancreatic cancer samples indicate that metastasized cells present significantly lower heterogeneity than primary tumor cells. We found the same morphological signature for metastasis for a cohort of 10 breast cancer cell lines. We further decipher the relative contributions to heterogeneity from cell cycle, cell-cell contact, cell stochasticity and heritable morphological variations. PMID:26675084

  14. Xenopus embryonic epidermis as a mucociliary cellular ecosystem to assess the effect of sex hormones in a non-reproductive context

    PubMed Central

    2014-01-01

    Background How important are sexual hormones beyond their function in reproductive biology has yet to be understood. In this study, we analyzed the effects of sex steroids on the biology of the embryonic amphibian epidermis, which represents an easily amenable model of non-reproductive mucociliary epithelia (MCE). MCE are integrated systems formed by multiciliated (MC), mucus-secreting (MS) and mitochondrion-rich (MR) cell populations that are shaped by their microenvironment. Therefore, MCE could be considered as ecosystems at the cellular scale, found in a wide array of contexts from mussel gills to mammalian oviduct. Results We showed that the natural estrogen (estradiol, E2) and androgen (testosterone, T) as well as the synthetic estrogen (ethinyl-estradiol, EE2), all induced a significant enhancement of MC cell numbers. The effect of E2, T and EE2 extended to the MS and MR cell populations, to varying degrees. They also modified the expression profile of RNA MCE markers, and induced a range of “non-typical” cellular phenotypes, with mixed identities and aberrant morphologies, as revealed by imaging analysis through biomarker confocal detection and scanning electron microscopy. Finally, these hormones also affected tadpole pigmentation, revealing an effect on the entire cellular ecosystem of the Xenopus embryonic skin. Conclusions This study reveals the impact in vivo, at the molecular, cellular, tissue and organism levels, of sex steroids on non-reproductive mucociliary epithelium biogenesis, and validates the use of Xenopus as a relevant model system in this field. PMID:24502321

  15. In vitro cellular uptake of evodiamine and rutaecarpine using a microemulsion

    PubMed Central

    Zhang, Yong-Tai; Huang, Zhe-Bin; Zhang, Su-Juan; Zhao, Ji-Hui; Wang, Zhi; Liu, Ying; Feng, Nian-Ping

    2012-01-01

    Objective To investigate the cellular uptake of evodiamine and rutaecarpine in a microemulsion in comparison with aqueous suspensions and tinctures. Materials and methods A microemulsion was prepared using the dropwise addition method. Mouse skin fibroblasts were cultured in vitro to investigate the optimal conditions for evodiamine and rutaecarpine uptake with different drug concentrations and administration times. Under optimal conditions, the cellular uptake of microemulsified drugs was assayed and compared to tinctures and aqueous suspensions. Rhodamine B labeling and laser scanning confocal microscopy (LSCM) were used to explore the distribution of fluorochrome transferred with the microemulsion in fibroblasts. Cellular morphology was also investigated, using optical microscopy to evaluate microemulsion-induced cellular toxicity. Results The maximum cellular drug uptake amounts were obtained with a 20% concentration (v/v) of microemulsion and an 8 hour administration time. Drug uptake by mouse skin fibroblasts was lowest when the drugs were loaded in microemulsion. After incubation with rhodamine B-labeled microemulsion for 8 hours, the highest fluorescence intensity was achieved, and the fluorochrome was primarily distributed in the cytochylema. No obvious cellular morphologic changes were observed with the administration of either the microemulsion or the aqueous suspension; for the tincture group, however, massive cellular necrocytosis was observed. Conclusion The lower cellular uptake with microemulsion may be due to the fact that most of the drug loaded in the microemulsion vehicle was transported via the intercellular space, while a small quantity of free drug (released from the vehicle) was ingested through transmembrane transport. Mouse skin fibroblasts rarely endocytosed evodiamine and rutaecarpine with a microemulsion as the vehicle. The microemulsion had no obvious effect on cellular morphology, suggesting there is little or no cellular toxicity

  16. Comparative study of plant responses to carbon-based nanomaterials with different morphologies.

    PubMed

    Lahiani, Mohamed H; Dervishi, Enkeleda; Ivanov, Ilia; Chen, Jihua; Khodakovskaya, Mariya

    2016-07-01

    The relationship between the morphology of carbon-based nanomaterials (CBNs) and the specific response of plants exposed to CBNs has not been studied systematically. Here, we prove that CBNs with different morphologies can activate cell growth, germination, and plant growth. A tobacco cell culture growth was found to increase by 22%-46% when CBNs such as helical multi-wall carbon nanotubes (MWCNTs), few-layered graphene, long MWCNTs, and short MWCNTs were added to the growth medium at a concentration of 50 μg ml(-1). The germination of exposed tomato seeds, as well as the growth of exposed tomato seedlings, were significantly enhanced by the addition of all tested CBNs. The presence of CBNs inside exposed seeds was confirmed by transmission electron microscopy and Raman spectroscopy. The effects of helical MWCNTs on gene expression in tomato seeds and seedlings were investigated by microarray technology and real time-PCR. Helical MWCNTs affected a number of genes involved in cellular and metabolic processes and response to stress factors. It was shown that the expression of the tomato water channel gene in tomato seeds exposed to helical MWCNTs was upregulated. These established findings demonstrate that CBNs with different morphologies can cause the same biological effects and share similar mechanisms in planta. PMID:27195934

  17. Comparative study of plant responses to carbon-based nanomaterials with different morphologies

    DOE PAGESBeta

    Lahiani, Mohamed H.; Dervishi, Enkeleda; Ivanov, Ilia; Chen, Jihua; Khodakovskaya, Mariya

    2016-05-19

    The relationship between the morphology of carbon-based nanomaterials (CBNs) and the specific response of plants exposed to CBNs has not been studied systematically. Here, we prove that CBNs with different morphologies can activate cell growth, germination, and plant growth. A tobacco cell culture growth was found to increase by 22%–46% when CBNs such as helical multi-wall carbon nanotubes (MWCNTs), few-layered graphene, long MWCNTs, and short MWCNTs were added to the growth medium at a concentration of 50 μg ml–1. The germination of exposed tomato seeds, as well as the growth of exposed tomato seedlings, were significantly enhanced by the additionmore » of all tested CBNs. The presence of CBNs inside exposed seeds was confirmed by transmission electron microscopy and Raman spectroscopy. The effects of helical MWCNTs on gene expression in tomato seeds and seedlings were investigated by microarray technology and real time-PCR. Helical MWCNTs affected a number of genes involved in cellular and metabolic processes and response to stress factors. It was shown that the expression of the tomato water channel gene in tomato seeds exposed to helical MWCNTs was upregulated. Furthermore, these established findings demonstrate that CBNs with different morphologies can cause the same biological effects and share similar mechanisms in planta.« less

  18. Comparative study of plant responses to carbon-based nanomaterials with different morphologies

    NASA Astrophysics Data System (ADS)

    Lahiani, Mohamed H.; Dervishi, Enkeleda; Ivanov, Ilia; Chen, Jihua; Khodakovskaya, Mariya

    2016-07-01

    The relationship between the morphology of carbon-based nanomaterials (CBNs) and the specific response of plants exposed to CBNs has not been studied systematically. Here, we prove that CBNs with different morphologies can activate cell growth, germination, and plant growth. A tobacco cell culture growth was found to increase by 22%–46% when CBNs such as helical multi-wall carbon nanotubes (MWCNTs), few-layered graphene, long MWCNTs, and short MWCNTs were added to the growth medium at a concentration of 50 μg ml‑1. The germination of exposed tomato seeds, as well as the growth of exposed tomato seedlings, were significantly enhanced by the addition of all tested CBNs. The presence of CBNs inside exposed seeds was confirmed by transmission electron microscopy and Raman spectroscopy. The effects of helical MWCNTs on gene expression in tomato seeds and seedlings were investigated by microarray technology and real time-PCR. Helical MWCNTs affected a number of genes involved in cellular and metabolic processes and response to stress factors. It was shown that the expression of the tomato water channel gene in tomato seeds exposed to helical MWCNTs was upregulated. These established findings demonstrate that CBNs with different morphologies can cause the same biological effects and share similar mechanisms in planta.

  19. Accumulation of distinct prelamin A variants in human diploid fibroblasts differentially affects cell homeostasis.

    PubMed

    Candelario, Jose; Borrego, Stacey; Reddy, Sita; Comai, Lucio

    2011-02-01

    Lamin A is a component of the nuclear lamina that plays a major role in the structural organization and function of the nucleus. Lamin A is synthesized as a prelamin A precursor which undergoes four sequential post-translational modifications to generate mature lamin A. Significantly, a large number of point mutations in the LMNA gene cause a range of distinct human disorders collectively known as laminopathies. The mechanisms by which mutations in lamin A affect cell function and cause disease are unclear. Interestingly, recent studies have suggested that alterations in the normal lamin A pathway can contribute to cellular dysfunction. Specifically, we and others have shown, at the cellular level, that in the absence of mutations or altered splicing events, increased expression of wild-type prelamin A results in a growth defective phenotype that resembles that of cells expressing the mutant form of lamin A, termed progerin, associated with Hutchinson-Gilford Progeria syndrome (HGPS). Remarkably, the phenotypes of cells expressing elevated levels of wild-type prelamin A can be reversed by either treatment with farnesyltransferase inhibitors or overexpression of ZMPSTE24, a critical prelamin A processing enzyme, suggesting that minor increases in the steady-state levels of one or more prelamin A intermediates is sufficient to induce cellular toxicity. Here, to investigate the molecular basis of the lamin A pathway toxicity, we characterized the phenotypic changes occurring in cells expressing distinct prelamin A variants mimicking specific prelamin A processing intermediates. This analysis demonstrates that distinct prelamin A variants differentially affect cell growth, nuclear membrane morphology, nuclear distribution of lamin A and the fundamental process of transcription. Expression of prelamin A variants that are constitutively farnesylated induced the formation of lamin A aggregates and dramatic changes in nuclear membrane morphology, which led to reduced

  20. Accumulation of distinct prelamin A variants in human diploid fibroblasts differentially affects cell homeostasis

    SciTech Connect

    Candelario, Jose; Borrego, Stacey; Reddy, Sita; Comai, Lucio

    2011-02-01

    Lamin A is a component of the nuclear lamina that plays a major role in the structural organization and function of the nucleus. Lamin A is synthesized as a prelamin A precursor which undergoes four sequential post-translational modifications to generate mature lamin A. Significantly, a large number of point mutations in the LMNA gene cause a range of distinct human disorders collectively known as laminopathies. The mechanisms by which mutations in lamin A affect cell function and cause disease are unclear. Interestingly, recent studies have suggested that alterations in the normal lamin A pathway can contribute to cellular dysfunction. Specifically, we and others have shown, at the cellular level, that in the absence of mutations or altered splicing events, increased expression of wild-type prelamin A results in a growth defective phenotype that resembles that of cells expressing the mutant form of lamin A, termed progerin, associated with Hutchinson-Gilford Progeria syndrome (HGPS). Remarkably, the phenotypes of cells expressing elevated levels of wild-type prelamin A can be reversed by either treatment with farnesyltransferase inhibitors or overexpression of ZMPSTE24, a critical prelamin A processing enzyme, suggesting that minor increases in the steady-state levels of one or more prelamin A intermediates is sufficient to induce cellular toxicity. Here, to investigate the molecular basis of the lamin A pathway toxicity, we characterized the phenotypic changes occurring in cells expressing distinct prelamin A variants mimicking specific prelamin A processing intermediates. This analysis demonstrates that distinct prelamin A variants differentially affect cell growth, nuclear membrane morphology, nuclear distribution of lamin A and the fundamental process of transcription. Expression of prelamin A variants that are constitutively farnesylated induced the formation of lamin A aggregates and dramatic changes in nuclear membrane morphology, which led to reduced

  1. Affective Learning.

    ERIC Educational Resources Information Center

    Brown, Charles T.

    This paper addresses itself to the question, "What does feeling have to do with knowing?" Two movements in affective education are discussed which have come into focus in recent years and which attempt to define the relationship between knowing and feeling. The first, a conscious application of the role of arousal in learning, emphasizes arousal…

  2. The effect of combined and separate infection by Alcaligenes faecalis and paramyxovirus (Yucaipa) on the surface morphology of the trachea in turkey poults.

    PubMed

    Yegana, Y; Weismen, Y; Herz, A; Schapira, R; Hod, I

    1985-10-01

    Sixty-seven 1-day-old turkey poults were inoculated in the infra orbital sinus with 3 x 10(8) Alcaligenes faecalis bacteria and/or by 10(5.8)EID 50/ ml of Yucaipa virus. Twenty-five similar birds served as controls. Identification of the agents inoculated was made during the development of disease by means of isolation and serological tests. During the development of the disease, the surface morphology of the trachea in the affected animals revealed cellular oedema associated with a mucus coating of the cilia. PMID:18766948

  3. Morphological representation in an endangered, polysynthetic language.

    PubMed

    Rice, Sally; Libben, Gary; Derwing, Bruce

    2002-01-01

    This article presents the results from an initial psycholinguistic study of patterns of morphological representation in Dene Suliné (Chipewyan), an indigenous and highly endangered language spoken in Northwestern Canada. Our investigation focused on how morphological knowledge in this polysynthetic language is affected across various levels of language attrition by employing a morphological segmentation task and an off-line lexical decision task. We discuss the manner in which these tasks target different aspects of morphological ability and then turn to methodological issues associated with conducting psycholinguistic studies with language users that differ in levels of age, education, literacy, and bilingualism (Dene- English). Finally, we report on the challenges of doing psycholinguistic research outside the confines of a university setting and make some recommendations to other researchers who might wish to undertake similar studies. PMID:12081415

  4. Continuum representations of cellular solids

    SciTech Connect

    Neilsen, M.K.

    1993-09-01

    Cellular materials consist of interconnected struts or plates which form cells. The struts or plates are constructed from a variety of metals, polymers, ceramics and wood products. Cellular materials are often used in impact limiters for shipping containers to protect the contents from accidental impact events. These materials exhibit a variety of complex behavior when subjected to crushing loads. This research focuses on the development of continuum representations of cellular solids that can be used in the finite element analysis of shipping container accidents. A significant portion of this work is the development of a new methodology to relate localized deformations to appropriate constitutive descriptions. This methodology provides the insight needed to select constitutive descriptions for cellular solids that capture the localized deformations that are observed experimentally. Constitutive relations are developed for two different cellular materials, aluminum honeycomb and polyurethane foam. These constitutive relations are based on plasticity and continuum damage theories. Plasticity is used to describe the permanent deformation exhibited by both aluminum honeycomb and polyurethane foam. Continuum damage is needed to capture the change in elastic parameters due to cracking of the polyurethane cell wall materials. The new constitutive description of polyurethane foam is implemented in both static and dynamic finite element codes, and analytical and numerical predictions are compared with available experimental data.

  5. Temperature affects the morphology and calcification of Emiliania huxleyi strains

    NASA Astrophysics Data System (ADS)

    Rosas-Navarro, Anaid; Langer, Gerald; Ziveri, Patrizia

    2016-05-01

    The global warming debate has sparked an unprecedented interest in temperature effects on coccolithophores. The calcification response to temperature changes reported in the literature, however, is ambiguous. The two main sources of this ambiguity are putatively differences in experimental setup and strain specificity. In this study we therefore compare three strains isolated in the North Pacific under identical experimental conditions. Three strains of Emiliania huxleyi type A were grown under non-limiting nutrient and light conditions, at 10, 15, 20 and 25 °C. All three strains displayed similar growth rate versus temperature relationships, with an optimum at 20-25 °C. Elemental production (particulate inorganic carbon (PIC), particulate organic carbon (POC), total particulate nitrogen (TPN)), coccolith mass, coccolith size, and width of the tube element cycle were positively correlated with temperature over the sub-optimum to optimum temperature range. The correlation between PIC production and coccolith mass/size supports the notion that coccolith mass can be used as a proxy for PIC production in sediment samples. Increasing PIC production was significantly positively correlated with the percentage of incomplete coccoliths in one strain only. Generally, coccoliths were heavier when PIC production was higher. This shows that incompleteness of coccoliths is not due to time shortage at high PIC production. Sub-optimal growth temperatures lead to an increase in the percentage of malformed coccoliths in a strain-specific fashion. Since in total only six strains have been tested thus far, it is presently difficult to say whether sub-optimal temperature is an important factor causing malformations in the field. The most important parameter in biogeochemical terms, the PIC : POC ratio, shows a minimum at optimum growth temperature in all investigated strains. This clarifies the ambiguous picture featuring in the literature, i.e. discrepancies between PIC : POC-temperature relationships reported in different studies using different strains and different experimental setups. In summary, global warming might cause a decline in coccolithophore's PIC contribution to the rain ratio, as well as improved fitness in some genotypes due to fewer coccolith malformations.

  6. General morphological and biological features of neoplasms: integration of molecular findings.

    PubMed

    Diaz-Cano, S J

    2008-07-01

    This review highlights the importance of morphology-molecular correlations for a proper implementation of new markers. It covers both general aspects of tumorigenesis (which are normally omitted in papers analysing molecular pathways) and the general mechanisms for the acquired capabilities of neoplasms. The mechanisms are also supported by appropriate diagrams for each acquired capability that include overlooked features such as mobilization of cellular resources and changes in chromatin, transcription and epigenetics; fully accepted oncogenes and tumour suppressor genes are highlighted, while the pathways are also presented as activating or inactivating with appropriate colour coding. Finally, the concepts and mechanisms presented enable us to understand the basic requirements for the appropriate implementation of molecular tests in clinical practice. In summary, the basic findings are presented to serve as a bridge to clinical applications. The current definition of neoplasm is descriptive and difficult to apply routinely. Biologically, neoplasms develop through acquisition of capabilities that involve tumour cell aspects and modified microenvironment interactions, resulting in unrestricted growth due to a stepwise accumulation of cooperative genetic alterations that affect key molecular pathways. The correlation of these molecular aspects with morphological changes is essential for better understanding of essential concepts as early neoplasms/precancerous lesions, progression/dedifferentiation, and intratumour heterogeneity. The acquired capabilities include self-maintained replication (cell cycle dysregulation), extended cell survival (cell cycle arrest, apoptosis dysregulation, and replicative lifespan), genetic instability (chromosomal and microsatellite), changes of chromatin, transcription and epigenetics, mobilization of cellular resources, and modified microenvironment interactions (tumour cells, stromal cells, extracellular, endothelium). The acquired

  7. The Morphological and Molecular Changes of Brain Cells Exposed to Direct Current Electric Field Stimulation

    PubMed Central

    Pelletier, Simon J.; Lagacé, Marie; St-Amour, Isabelle; Arsenault, Dany; Cisbani, Giulia; Chabrat, Audrey; Fecteau, Shirley; Lévesque, Martin

    2015-01-01

    Background: The application of low-intensity direct current electric fields has been experimentally used in the clinic to treat a number of brain disorders, predominantly using transcranial direct current stimulation approaches. However, the cellular and molecular changes induced by such treatment remain largely unknown. Methods: Here, we tested various intensities of direct current electric fields (0, 25, 50, and 100V/m) in a well-controlled in vitro environment in order to investigate the responses of neurons, microglia, and astrocytes to this type of stimulation. This included morphological assessments of the cells, viability, as well as shape and fiber outgrowth relative to the orientation of the direct current electric field. We also undertook enzyme-linked immunosorbent assays and western immunoblotting to identify which molecular pathways were affected by direct current electric fields. Results: In response to direct current electric field, neurons developed an elongated cell body shape with neurite outgrowth that was associated with a significant increase in growth associated protein-43. Fetal midbrain dopaminergic explants grown in a collagen gel matrix also showed a reorientation of their neurites towards the cathode. BV2 microglial cells adopted distinct morphological changes with an increase in cyclooxygenase-2 expression, but these were dependent on whether they had already been activated with lipopolysaccharide. Finally, astrocytes displayed elongated cell bodies with cellular filopodia that were oriented perpendicularly to the direct current electric field. Conclusion: We show that cells of the central nervous system can respond to direct current electric fields both in terms of their morphological shape and molecular expression of certain proteins, and this in turn can help us to begin understand the mechanisms underlying the clinical benefits of direct current electric field. PMID:25522422

  8. Morphological plasticity of astroglia: Understanding synaptic microenvironment

    PubMed Central

    2015-01-01

    Memory formation in the brain is thought to rely on the remodeling of synaptic connections which eventually results in neural network rewiring. This remodeling is likely to involve ultrathin astroglial protrusions which often occur in the immediate vicinity of excitatory synapses. The phenomenology, cellular mechanisms, and causal relationships of such astroglial restructuring remain, however, poorly understood. This is in large part because monitoring and probing of the underpinning molecular machinery on the scale of nanoscopic astroglial compartments remains a challenge. Here we briefly summarize the current knowledge regarding the cellular organisation of astroglia in the synaptic microenvironment and discuss molecular mechanisms potentially involved in use‐dependent astroglial morphogenesis. We also discuss recent observations concerning morphological astroglial plasticity, the respective monitoring methods, and some of the newly emerging techniques that might help with conceptual advances in the area. GLIA 2015;63:2133–2151 PMID:25782611

  9. Aging, Cellular Senescence, and Cancer

    PubMed Central

    Campisi, Judith

    2014-01-01

    For most species, aging promotes a host of degenerative pathologies that are characterized by debilitating losses of tissue or cellular function. However, especially among vertebrates, aging also promotes hyperplastic pathologies, the most deadly of which is cancer. In contrast to the loss of function that characterizes degenerating cells and tissues, malignant (cancerous) cells must acquire new (albeit aberrant) functions that allow them to develop into a lethal tumor. This review discusses the idea that, despite seemingly opposite characteristics, the degenerative and hyperplastic pathologies of aging are at least partly linked by a common biological phenomenon: a cellular stress response known as cellular senescence. The senescence response is widely recognized as a potent tumor suppressive mechanism. However, recent evidence strengthens the idea that it also drives both degenerative and hyper-plastic pathologies, most likely by promoting chronic inflammation. Thus, the senescence response may be the result of antagonistically pleiotropic gene action. PMID:23140366

  10. Aging, cellular senescence, and cancer.

    PubMed

    Campisi, Judith

    2013-01-01

    For most species, aging promotes a host of degenerative pathologies that are characterized by debilitating losses of tissue or cellular function. However, especially among vertebrates, aging also promotes hyperplastic pathologies, the most deadly of which is cancer. In contrast to the loss of function that characterizes degenerating cells and tissues, malignant (cancerous) cells must acquire new (albeit aberrant) functions that allow them to develop into a lethal tumor. This review discusses the idea that, despite seemingly opposite characteristics, the degenerative and hyperplastic pathologies of aging are at least partly linked by a common biological phenomenon: a cellular stress response known as cellular senescence. The senescence response is widely recognized as a potent tumor suppressive mechanism. However, recent evidence strengthens the idea that it also drives both degenerative and hyperplastic pathologies, most likely by promoting chronic inflammation. Thus, the senescence response may be the result of antagonistically pleiotropic gene action. PMID:23140366

  11. Fracture mechanics of cellular glass

    NASA Technical Reports Server (NTRS)

    Zwissler, J. G.; Adams, M. A.

    1981-01-01

    The fracture mechanics of cellular glasses (for the structural substrate of mirrored glass for solr concentrator reflecting panels) are discussed. Commercial and developmental cellular glasses were tested and analyzed using standard testing techniques and models developed from linear fracture mechanics. Two models describing the fracture behavior of these materials were developed. Slow crack growth behavior in cellular glass was found to be more complex than that encountered in dense glasses or ceramics. The crack velocity was found to be strongly dependent upon water vapor transport to the tip of the moving crack. The existence of a static fatigue limit was not conclusively established, however, it is speculated that slow crack growth behavior in Region 1 may be slower, by orders of magnitude, than that found in dense glasses.

  12. Cellular-based preemption system

    NASA Technical Reports Server (NTRS)

    Bachelder, Aaron D. (Inventor)

    2011-01-01

    A cellular-based preemption system that uses existing cellular infrastructure to transmit preemption related data to allow safe passage of emergency vehicles through one or more intersections. A cellular unit in an emergency vehicle is used to generate position reports that are transmitted to the one or more intersections during an emergency response. Based on this position data, the one or more intersections calculate an estimated time of arrival (ETA) of the emergency vehicle, and transmit preemption commands to traffic signals at the intersections based on the calculated ETA. Additional techniques may be used for refining the position reports, ETA calculations, and the like. Such techniques include, without limitation, statistical preemption, map-matching, dead-reckoning, augmented navigation, and/or preemption optimization techniques, all of which are described in further detail in the above-referenced patent applications.

  13. Quantitative Analysis of Mitochondrial Morphology and Membrane Potential in Living Cells Using High-Content Imaging, Machine Learning, and Morphological Binning

    PubMed Central

    Leonard, Anthony P.; Cameron, Robert B.; Speiser, Jaime L.; Wolf, Bethany J.; Peterson, Yuri K.; Schnellmann, Rick G.; Beeson, Craig C.; Rohrer, Baerbel

    2014-01-01

    Understanding the processes of mitochondrial dynamics (fission, fusion, biogenesis, and mitophagy) has been hampered by the lack of automated, deterministic methods to measure mitochondrial morphology from microscopic images. A method to quantify mitochondrial morphology and function is presented here using a commercially available automated high-content wide-field fluorescent microscopy platform and R programming-language-based semi-automated data analysis to achieve high throughput morphological categorization (puncta, rod, network, and large & round) and quantification of mitochondrial membrane potential. In conjunction with cellular respirometry to measure mitochondrial respiratory capacity, this method detected that increasing concentrations of toxicants known to directly or indirectly affect mitochondria (t-butyl hydroperoxide [TBHP], rotenone, antimycin A, oligomycin, ouabain, and carbonyl cyanide-p-trifluoromethoxyphenylhydrazone [FCCP]), decreased mitochondrial networked areas in cultured 661w cells to 0.60-0.80 at concentrations that inhibited respiratory capacity to 0.20-0.70 (fold change compared to vehicle). Concomitantly, mitochondrial swelling was increased from 1.4- to 2.3-fold of vehicle as indicated by changes in large & round areas in response to TBHP, oligomycin, or ouabain. Finally, the automated identification of mitochondrial location enabled accurate quantification of mitochondrial membrane potential by measuring intramitochondrial tetramethylrhodamine methyl ester (TMRM) fluorescence intensity. Administration of FCCP depolarized and administration of oligomycin hyperpolarized mitochondria, as evidenced by changes in intramitochondrial TMRM fluorescence intensities to 0.33- or 5.25-fold of vehicle control values, respectively. In summary, this high-content imaging method accurately quantified mitochondrial morphology and membrane potential in hundreds of thousands of cells on a per-cell basis, with sufficient throughput for pharmacological

  14. Arrested Development: High-Resolution Imaging of Foveal Morphology in Albinism

    PubMed Central

    McAllister, John T.; Dubis, Adam M.; Tait, Diane M.; Ostler, Shawn; Rha, Jungtae; Stepien, Kimberly E.; Summers, C. Gail; Carroll, Joseph

    2010-01-01

    Albinism, an inherited disorder of melanin biosynthesis, disrupts normal retinal development, with foveal hypoplasia as one of the more commonly associated ocular phenotypes. However the cellular integrity of the fovea in albinism is not well understood – there likely exist important anatomical differences that underlie phenotypic variability within the disease and that also may affect responsiveness to therapeutic intervention. Here, using spectral domain optical coherence tomography (SD-OCT) and adaptive optics (AO) retinal imaging, we obtained high-resolution images of the foveal region in six individuals with albinism. We provide a quantitative analysis of cone density and outer segment elongation demonstrating that foveal cone specialization is variable in albinism. In addition, our data reveal a continuum of foveal pit morphology, roughly aligning with schematics of normal foveal development based on post-mortem analyses. Different albinism subtypes, genetic mutations, and constitutional pigment background likely play a role in determining the degree of foveal maturation. PMID:20149815

  15. [The myocardial histo-hematic barrier as a morphological criterion to be used for forensic medical diagnostics of alcoholic cardiomyopathy].

    PubMed

    Yagmurov, O D

    2015-01-01

    The author estimates the effectiveness of morphological diagnostics of alcoholic cardiomyopathy taking into consideration the general patterns of the structural and functional organization of the heart with special reference to myocardial histo-hematic barrier (HHB) the components of which are characterized by specific structural and functional properties and close relationships between them. It was shown that the morphological changes in the histo-hematic barrier reflect the range of variability of its morphological components and may be used as the indicators of its integrity and stability in the case of disorder. The study has demonstrated that the structural and functional degradation as well as decay of myocardial components may occur under the influence of both an ultrastrong acute impact and latent chronic intoxication or the diseases accompanied by rapid or slow persisting disintegration of the structural organization of the organ. The author maintains that the maximally high informative value of the assessment of the morphological criteria for alcoholic cardiomyopathy can be achieved with the use of special immunohistochemical methods allowing the concrete components of the biological structures to be identified and giving the exact location of the cellular and tissue components in the affected regions. Such an approach permits to detect the developing pathological changes at the molecular level with a high degree of accuracy and visualize the structural reorganization, if any, of each component of the myocardial histo-hematic barrier responsible for the lesions associated with alcoholic cardiomyopathy. PMID:26245095

  16. Synthetic biology in cellular immunotherapy

    PubMed Central

    Chakravarti, Deboki; Wong, Wilson W.

    2015-01-01

    The adoptive transfer of genetically engineered T cells with cancer-targeting receptors has shown tremendous promise for eradicating tumors in clinical trials. This form of cellular immunotherapy presents a unique opportunity to incorporate advanced systems and synthetic biology approaches to create cancer therapeutics with novel functions. Here, we first review the development of synthetic receptors, switches, and circuits to control the location, duration, and strength of T cell activity against tumors. In addition, we discuss the cellular engineering and genome editing of host cells (or the chassis) to improve the efficacy of cell-based cancer therapeutics, and to reduce the time and cost of manufacturing. PMID:26088008

  17. Global properties of cellular automata

    SciTech Connect

    Jen, E.

    1986-04-01

    Cellular automata are discrete mathematical systems that generate diverse, often complicated, behavior using simple deterministic rules. Analysis of the local structure of these rules makes possible a description of the global properties of the associated automata. A class of cellular automata that generate infinitely many aperoidic temporal sequences is defined,a s is the set of rules for which inverses exist. Necessary and sufficient conditions are derived characterizing the classes of ''nearest-neighbor'' rules for which arbitrary finite initial conditions (i) evolve to a homogeneous state; (ii) generate at least one constant temporal sequence.

  18. Cellular automaton for chimera states

    NASA Astrophysics Data System (ADS)

    García-Morales, Vladimir

    2016-04-01

    A minimalistic model for chimera states is presented. The model is a cellular automaton (CA) which depends on only one adjustable parameter, the range of the nonlocal coupling, and is built from elementary cellular automata and the majority (voting) rule. This suggests the universality of chimera-like behavior from a new point of view: Already simple CA rules based on the majority rule exhibit this behavior. After a short transient, we find chimera states for arbitrary initial conditions, the system spontaneously splitting into stable domains separated by static boundaries, some synchronously oscillating and the others incoherent. When the coupling range is local, nontrivial coherent structures with different periodicities are formed.

  19. Adaptive stochastic cellular automata: Applications

    NASA Astrophysics Data System (ADS)

    Qian, S.; Lee, Y. C.; Jones, R. D.; Barnes, C. W.; Flake, G. W.; O'Rourke, M. K.; Lee, K.; Chen, H. H.; Sun, G. Z.; Zhang, Y. Q.; Chen, D.; Giles, C. L.

    1990-09-01

    The stochastic learning cellular automata model has been applied to the problem of controlling unstable systems. Two example unstable systems studied are controlled by an adaptive stochastic cellular automata algorithm with an adaptive critic. The reinforcement learning algorithm and the architecture of the stochastic CA controller are presented. Learning to balance a single pole is discussed in detail. Balancing an inverted double pendulum highlights the power of the stochastic CA approach. The stochastic CA model is compared to conventional adaptive control and artificial neural network approaches.

  20. Cellular senescence in aging primates.

    PubMed

    Herbig, Utz; Ferreira, Mark; Condel, Laura; Carey, Dee; Sedivy, John M

    2006-03-01

    The aging of organisms is characterized by a gradual functional decline of all organ systems. Mammalian somatic cells in culture display a limited proliferative life span, at the end of which they undergo an irreversible cell cycle arrest known as replicative senescence. Whether cellular senescence contributes to organismal aging has been controversial. We investigated telomere dysfunction, a recently discovered biomarker of cellular senescence, and found that the number of senescent fibroblasts increases exponentially in the skin of aging baboons, reaching >15% of all cells in very old individuals. In addition, the same cells contain activated ataxia-telangiectasia mutated kinase and heterochromatinized nuclei, confirming their senescent status. PMID:16456035

  1. Cellular basis of Alzheimer's disease.

    PubMed

    Bali, Jitin; Halima, Saoussen Ben; Felmy, Boas; Goodger, Zoe; Zurbriggen, Sebastian; Rajendran, Lawrence

    2010-12-01

    Alzheimer's disease (AD) is the most common form of neurodegenerative disease. A characteristic feature of the disease is the presence of amyloid-β (Aβ) which either in its soluble oligomeric form or in the plaque-associated form is causally linked to neurodegeneration. Aβ peptide is liberated from the membrane-spanning -amyloid precursor protein by sequential proteolytic processing employing β- and γ-secretases. All these proteins involved in the production of Aβ peptide are membrane associated and hence, membrane trafficking and cellular compartmentalization play important roles. In this review, we summarize the key cellular events that lead to the progression of AD. PMID:21369424

  2. Single-cell resolution of morphological changes in hemogenic endothelium.

    PubMed

    Bos, Frank L; Hawkins, John S; Zovein, Ann C

    2015-08-01

    Endothelial-to-hematopoietic transition (EHT) occurs within a population of hemogenic endothelial cells during embryogenesis, and leads to the formation of the adult hematopoietic system. Currently, the prospective identification of specific endothelial cells that will undergo EHT, and the cellular events enabling this transition, are not known. We set out to define precisely the morphological events of EHT, and to correlate cellular morphology with the expression of the transcription factors RUNX1 and SOX17. A novel strategy was developed to allow for correlation of immunofluorescence data with the ultrastructural resolution of scanning electron microscopy. The approach can identify single endothelial cells undergoing EHT, as identified by the ratio of RUNX1 to SOX17 immunofluorescence levels, and the morphological changes associated with the transition. Furthermore, this work details a new technical resource that is widely applicable for correlative analyses of single cells in their native tissue environments. PMID:26243871

  3. Multilayer Coating of Tetrandrine-loaded PLGA nanoparticles: Effect of surface charges on cellular uptake rate and drug release profile.

    PubMed

    Meng, Rui; Li, Ke; Chen, Zhe; Shi, Chen

    2016-02-01

    The effect of surface charges on the cellular uptake rate and drug release profile of tetrandrine-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (TPNs) was studied. Stabilizer-free nanoprecipitation method was used in this study for the synthesis of TPNs. A typical layer-by-layer approach was applied for multi-coating particles' surface with use of poly(styrene sulfonate) sodium salt (PSS) as anionic layer and poly(allylamine hydrochloride) (PAH) as cationic layer. The modified TPNs were characterized by different physicochemical techniques such as Zeta sizer, scanning electron microscopy and transmission electron microscopy. The drug loading efficiency, release profile and cellular uptake rate were evaluated by high performance liquid chromatography and confocal laser scanning microscopy, respectively. The resultant PSS/PAH/PSS/PAH/TPNs (4 layers) exhibited spherical-shaped morphology with the average size of 160.3±5.165 nm and zeta potential of-57.8 mV. The encapsulation efficiency and drug loading efficiency were 57.88% and 1.73%, respectively. Multi-layer coating of polymeric materials with different charges on particles' surface could dramatically influence the drug release profile of TPNs (4 layers vs. 3 layers). In addition, variable layers of surface coating could also greatly affect the cellular uptake rate of TPNs in A549 cells within 8 h. Overall, by coating particles' surface with those different charged polymers, precise control of drug release as well as cellular uptake rate can be achieved simultaneously. Thus, this approach provides a new strategy for controllable drug delivery. PMID:26838734

  4. Plant vacuole morphology and vacuolar trafficking

    PubMed Central

    Zhang, Chunhua; Hicks, Glenn R.; Raikhel, Natasha V.

    2014-01-01

    Plant vacuoles are essential organelles for plant growth and development, and have multiple functions. Vacuoles are highly dynamic and pleiomorphic, and their size varies depending on the cell type and growth conditions. Vacuoles compartmentalize different cellular components such as proteins, sugars, ions and other secondary metabolites and play critical roles in plants response to different biotic/abiotic signaling pathways. In this review, we will summarize the patterns of changes in vacuole morphology in certain cell types, our understanding of the mechanisms of plant vacuole biogenesis, and the role of SNAREs and Rab GTPases in vacuolar trafficking. PMID:25309565

  5. Modelling the morphology of migrating bacterial colonies

    NASA Astrophysics Data System (ADS)

    Nishiyama, A.; Tokihiro, T.; Badoual, M.; Grammaticos, B.

    2010-08-01

    We present a model which aims at describing the morphology of colonies of Proteus mirabilis and Bacillus subtilis. Our model is based on a cellular automaton which is obtained by the adequate discretisation of a diffusion-like equation, describing the migration of the bacteria, to which we have added rules simulating the consolidation process. Our basic assumption, following the findings of the group of Chuo University, is that the migration and consolidation processes are controlled by the local density of the bacteria. We show that it is possible within our model to reproduce the morphological diagrams of both bacteria species. Moreover, we model some detailed experiments done by the Chuo University group, obtaining a fine agreement.

  6. Morphological neural networks

    SciTech Connect

    Ritter, G.X.; Sussner, P.

    1996-12-31

    The theory of artificial neural networks has been successfully applied to a wide variety of pattern recognition problems. In this theory, the first step in computing the next state of a neuron or in performing the next layer neural network computation involves the linear operation of multiplying neural values by their synaptic strengths and adding the results. Thresholding usually follows the linear operation in order to provide for nonlinearity of the network. In this paper we introduce a novel class of neural networks, called morphological neural networks, in which the operations of multiplication and addition are replaced by addition and maximum (or minimum), respectively. By taking the maximum (or minimum) of sums instead of the sum of products, morphological network computation is nonlinear before thresholding. As a consequence, the properties of morphological neural networks are drastically different than those of traditional neural network models. In this paper we consider some of these differences and provide some particular examples of morphological neural network.

  7. Synthesis and cellular localization of porphyrinic pigments

    NASA Astrophysics Data System (ADS)

    Sareh, Sarah; Kong, Sarah; Parrales, Lenin; Jung, Anna; Cross, Kara; Röder, Beate; Isaac, Meden; Simonis, Ursula

    2009-06-01

    To determine factors that govern the uptake preference of photosensitizers in cellular organelles of human adenocarcinoma cells, diarginyl-dialkoxy- and diarginyl-dimethoxyphenylporphyrins (TPPs) and two of their corresponding indium(III) complexes were synthesized, characterized and incubated in androgen-sensitive human prostate adenocarcinoma cells LNCaP. The porphyrins revealed properties that are of importance for phototherapy. They are water-soluble, have their fourth Q-band absorbing at ~ 650 nm, are taken up in relatively high concentrations in LNCaP cells, and are phototoxic. Colocalization and phototoxicity studies revealed that all porphyrins localized preferentially to the lysosomes and invoked cell death when excited with 650 nm light. Compared to the corresponding methoxy-substituted TPPs, the diargininyl-dialkoxy-substituted porphyrins localized to a small extent in the mitochondria. The corresponding In(III) chloride complexes that are slightly less water-soluble were also taken up in the lysosomes of LnCaP cells. When the TPPs were compared to a pheophorbide derivative recently synthesized in our laboratory, it was determined that the TPPs have a preference for lysosomal localization, whereas the pheophorbide derivative co-localized to the mitochondria. Phototoxicity studies revealed that the longer chain dialkoxyTPPs were more effective in cell killing and induced greater morphological changes typical of apoptotic cell death than the shorter chain methoxy substituted porphyrins. The In(III) complexes seemed to be the most phototoxic. These results highlight that the type, nature, and substitution pattern of the chromophore modulate the extent of apoptotic cell death and influence cellular targeting.

  8. Factors Affecting Wound Healing

    PubMed Central

    Guo, S.; DiPietro, L.A.

    2010-01-01

    Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutaneous wound healing and the potential cellular and/or molecular mechanisms involved. The factors discussed include oxygenation, infection, age and sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition. A better understanding of the influence of these factors on repair may lead to therapeutics that improve wound healing and resolve impaired wounds. PMID:20139336

  9. Cannabinoid-induced actomyosin contractility shapes neuronal morphology and growth

    PubMed Central

    Roland, Alexandre B; Ricobaraza, Ana; Carrel, Damien; Jordan, Benjamin M; Rico, Felix; Simon, Anne; Humbert-Claude, Marie; Ferrier, Jeremy; McFadden, Maureen H; Scheuring, Simon; Lenkei, Zsolt

    2014-01-01

    Endocannabinoids are recently recognized regulators of brain development, but molecular effectors downstream of type-1 cannabinoid receptor (CB1R)-activation remain incompletely understood. We report atypical coupling of neuronal CB1Rs, after activation by endo- or exocannabinoids such as the marijuana component ∆9-tetrahydrocannabinol, to heterotrimeric G12/G13 proteins that triggers rapid and reversible non-muscle myosin II (NM II) dependent contraction of the actomyosin cytoskeleton, through a Rho-GTPase and Rho-associated kinase (ROCK). This induces rapid neuronal remodeling, such as retraction of neurites and axonal growth cones, elevated neuronal rigidity, and reshaping of somatodendritic morphology. Chronic pharmacological inhibition of NM II prevents cannabinoid-induced reduction of dendritic development in vitro and leads, similarly to blockade of endocannabinoid action, to excessive growth of corticofugal axons into the sub-ventricular zone in vivo. Our results suggest that CB1R can rapidly transform the neuronal cytoskeleton through actomyosin contractility, resulting in cellular remodeling events ultimately able to affect the brain architecture and wiring. DOI: http://dx.doi.org/10.7554/eLife.03159.001 PMID:25225054

  10. Diversity of dynamics and morphologies of invasive solid tumors

    NASA Astrophysics Data System (ADS)

    Jiao, Yang; Torquato, Salvatore

    2012-03-01

    Complex tumor-host interactions can significantly affect the growth dynamics and morphologies of progressing neoplasms. The growth of a confined solid tumor induces mechanical pressure and deformation of the surrounding microenvironment, which in turn influences tumor growth. In this paper, we generalize a recently developed cellular automaton model for invasive tumor growth in heterogeneous microenvironments [Y. Jiao and S. Torquato, PLoS Comput. Biol. 7, e1002314 (2011)] by incorporating the effects of pressure. Specifically, we explicitly model the pressure exerted on the growing tumor due to the deformation of the microenvironment and its effect on the local tumor-host interface instability. Both noninvasive-proliferative growth and invasive growth with individual cells that detach themselves from the primary tumor and migrate into the surrounding microenvironment are investigated. We find that while noninvasive tumors growing in "soft" homogeneous microenvironments develop almost isotropic shapes, both high pressure and host heterogeneity can strongly enhance malignant behavior, leading to finger-like protrusions of the tumor surface. Moreover, we show that individual invasive cells of an invasive tumor degrade the local extracellular matrix at the tumor-host interface, which diminishes the fingering growth of the primary tumor. The implications of our results for cancer diagnosis, prognosis and therapy are discussed.

  11. Overview of molecular, cellular, and genetic neurotoxicology.

    PubMed

    Wallace, David R

    2005-05-01

    /toxin combinations is they can be detected and measured shortly following exposure and before overt neuroanatomic damage or lesions. Intervention at this point, shortly following exposure, may prevent or at least attenuate further damage to the individual. The use of peripheral biomarkers to assess toxin damage in the CNS has numerous advantages: time-course analysis may be performed, ethical concerns with the use of human subjects can partially be avoided, procedures to acquire samples are less invasive, and in general, peripheral studies are easier to perform. Genetic neurotoxicology comprises two focuses--toxin-induced alterations in genetic expression and genetic alterations that affect toxin metabolism, distribution, and clearance. These differences can be beneficial or toxic. Polymorphisms have been shown to result in altered metabolism of certain toxins (paraoxonase and paraoxon). Conversely, it is possible that some polymorphisms may be beneficial and help prevent the formation of a toxic by-product of an exogenous agent (resistance to ozone-induced lung inflammation). It has also become clear that interactions of potential toxins are not straightforward as interactions with DNA, causing mutations. There are numerous agents that cause epigenetic responses (cellular alterations that are not mutagenic or cytotoxic). This finding suggests that many agents that may originally have been thought of as nontoxic should be re-examined for potential "indirect" toxicity. With the advancement of the human genome project and the development of a human genome map, the effects of potential toxins on single or multiple genes can be identified. Although collectively, the field of neurotoxicology has recently come a long way, it still has a long way to go reach its full potential. As technology and methodology advances continue and cooperation with other disciplines such as neuroscience, biochemistry, neurophysiology, and molecular biology is improved, the mechanisms of toxin action will be

  12. Wrinkling in Cellular Structured Composites

    NASA Astrophysics Data System (ADS)

    Kaynia, Narges; Li, Yaning; Boyce, Mary C.

    2013-03-01

    Many structured composites found in nature possess undulating and wrinkled interfacial layers that regulate mechanical, chemical, acoustic, adhesive, thermal, electrical and optical functions of the material. This research focused on the formation of wrinkling patterns in cellular structured composites and the effect of the wrinkling pattern on the overall structural response. The cellular composites consisted of stiffer interfacial layers constructing a network submerged in a soft matrix. Analytical and finite element models were developed to capture various aspects of the wrinkling mechanism. The characteristics of the undulation patterns and the instability modes were investigated as functions of model geometry and material composition. Mechanical experiments were designed to further explore the modeling results. The cellular composite samples were fabricated by using different types of elastomers and by varying the geometry and the material properties. The experimental and numerical results were consistent with the analytical predictions. The results in this research improve understanding of the mechanisms governing the undulation pattern formation in cellular composites and can be used to enable on-demand tunability of different functions to provide, among others, active control of wave propagation, mechanical stiffness and deformation, and material swelling and growth.

  13. Cellular Automata and the Humanities.

    ERIC Educational Resources Information Center

    Gallo, Ernest

    1994-01-01

    The use of cellular automata to analyze several pre-Socratic hypotheses about the evolution of the physical world is discussed. These hypotheses combine characteristics of both rigorous and metaphoric language. Since the computer demands explicit instructions for each step in the evolution of the automaton, such models can reveal conceptual…

  14. Morphology engineering - Osmolality and its effect on Aspergillus niger morphology and productivity

    PubMed Central

    2011-01-01

    Background The filamentous fungus Aspergillus niger is a widely used strain in a broad range of industrial processes from food to pharmaceutical industry. One of the most intriguing and often uncontrollable characteristics of this filamentous organism is its complex morphology, ranging from dense spherical pellets to viscous mycelia depending on culture conditions. Optimal productivity correlates strongly with a specific morphological form, thus making high demands on process control. Results In about 50 2L stirred tank cultivations the influence of osmolality on A. niger morphology and productivity was investigated. The specific productivity of fructofuranosidase producing strain A. niger SKAn 1015 could be increased notably from 0.5 to 9 U mg-1 h-1 around eighteen fold, by increasing the culture broth osmolality by addition of sodium chloride. The specific productivity of glucoamylase producing strain A. niger AB1.13, could be elevated using the same procedure. An optimal producing osmolality was shown to exist well over the standard osmolality at about 3.2 osmol kg-1 depending on the strain. Fungal morphology of all cultivations was examined by microscope and characterized by digital image analysis. Particle shape parameters were combined to a dimensionless Morphology number, which enabled a comprehensive characterization of fungal morphology correlating closely with productivity. A novel method for determination of germination time in submerged cultivations by laser diffraction, introduced in this study, revealed a decelerated germination process with increasing osmolality. Conclusions Through the introduction of the versatile Morphology number, this study provides the means for a desirable characterization of fungal morphology and demonstrates its relation to productivity. Furthermore, osmolality as a fairly new parameter in process engineering is introduced and found to affect fungal morphology and productivity. Osmolality might provide an auspicious and

  15. ALHAMBRA survey: morphological classification

    NASA Astrophysics Data System (ADS)

    Pović, M.; Huertas-Company, M.; Márquez, I.; Masegosa, J.; Aguerri, J. A. López; Husillos, C.; Molino, A.; Cristóbal-Hornillos, D.

    2015-03-01

    The Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) survey is a photometric survey designed to study systematically cosmic evolution and cosmic variance (Moles et al. 2008). It employs 20 continuous medium-band filters (3500 - 9700 Å), plus JHK near-infrared (NIR) bands, which enable measurements of photometric redshifts with good accuracy. ALHAMBRA covers > 4 deg2 in eight discontinuous regions (~ 0.5 deg2 per region), of theseseven fields overlap with other extragalactic, multiwavelength surveys (DEEP2, SDSS, COSMOS, HDF-N, Groth, ELAIS-N1). We detect > 600.000 sources, reaching the depth of R(AB) ~ 25.0, and photometric accuracy of 2-4% (Husillos et al., in prep.). Photometric redshifts are measured using the Bayesian Photometric Redshift (BPZ) code (Benítez et al. 2000), reaching one of the best accuracies up to date of δz/z <= 1.2% (Molino et al., in prep.). To deal with the morphological classification of galaxies in the ALHAMBRA survey (Pović et al., in prep.), we used the galaxy Support Vector Machine code (galSVM; Huertas-Company 2008, 2009), one of the new non-parametric methods for morphological classification, specially useful when dealing with low resolution and high-redshift data. To test the accuracy of our morphological classification we used a sample of 3000 local, visually classified galaxies (Nair & Abraham 2010), moving them to conditions typical of our ALHAMBRA data (taking into account the background, redshift and magnitude distributions, etc.), and measuring their morphology using galSVM. Finally, we measured the morphology of ALHAMBRA galaxies, obtaining for each source seven morphological parameters (two concentration indexes, asymmetry, Gini, M20 moment of light, smoothness, and elongation), probability if the source belongs to early- or late-type, and its error. Comparing ALHAMBRA morph COSMOS/ACS morphology (obtained with the same method) we expect to have qualitative separation in two main morphological

  16. Permanent embryo arrest: molecular and cellular concepts.

    PubMed

    Betts, D H; Madan, P

    2008-08-01

    Developmental arrest is one of the mechanisms responsible for the elevated levels of embryo demise during the first week of in vitro development. Approximately 10-15% of IVF embryos permanently arrest in mitosis at the 2- to 4-cell cleavage stage showing no indication of apoptosis. Reactive oxygen species (ROS) are implicated in this process and must be controlled in order to optimize embryo production. A stress sensor that can provide a key understanding of permanent cell cycle arrest and link ROS with cellular signaling pathway(s) is p66Shc, an adaptor protein for apoptotic-response to oxidative stress. Deletion of the p66Shc gene in mice results in extended lifespan, which is linked to their enhanced resistance to oxidative stress and reduced levels of apoptosis. p66Shc has been shown to generate mitochondrial H(2)O(2) to trigger apoptosis, but may also serve as an integration point for many signaling pathways that affect mitochondrial function. We have detected elevated levels of p66Shc and ROS within arrested embryos and believe that p66Shc plays a central role in regulating permanent embryo arrest. In this paper, we review the cellular and molecular aspects of permanent embryo arrest and speculate on the mechanism(s) and etiology of this method of embryo demise. PMID:18511487

  17. Conformational Sampling of Peptides in Cellular Environments☆

    PubMed Central

    Tanizaki, Seiichiro; Clifford, Jacob; Connelly, Brian D.; Feig, Michael

    2008-01-01

    Abstract Biological systems provide a complex environment that can be understood in terms of its dielectric properties. High concentrations of macromolecules and cosolvents effectively reduce the dielectric constant of cellular environments, thereby affecting the conformational sampling of biomolecules. To examine this effect in more detail, the conformational preference of alanine dipeptide, poly-alanine, and melittin in different dielectric environments is studied with computer simulations based on recently developed generalized Born methodology. Results from these simulations suggest that extended conformations are favored over α-helical conformations at the dipeptide level at and below dielectric constants of 5–10. Furthermore, lower-dielectric environments begin to significantly stabilize helical structures in poly-alanine at ɛ = 20. In the more complex peptide melittin, different dielectric environments shift the equilibrium between two main conformations: a nearly fully extended helix that is most stable in low dielectrics and a compact, V-shaped conformation consisting of two helices that is preferred in higher dielectric environments. An additional conformation is only found to be significantly populated at intermediate dielectric constants. Good agreement with previous studies of different peptides in specific, less-polar solvent environments, suggest that helix stabilization and shifts in conformational preferences in such environments are primarily due to a reduced dielectric environment rather than specific molecular details. The findings presented here make predictions of how peptide sampling may be altered in dense cellular environments with reduced dielectric response. PMID:17905846

  18. Hydrodynamics, Fungal Physiology, and Morphology.

    PubMed

    Serrano-Carreón, L; Galindo, E; Rocha-Valadéz, J A; Holguín-Salas, A; Corkidi, G

    2015-01-01

    common morphologies exhibited by filamentous microorganisms; (b) how hydrodynamic conditions affect morphology and physiology in filamentous cultures; and (c) techniques using digital image analysis to characterize the viability of filamentous microorganisms and mass transfer in multiphase dispersions. Representative case studies of fungi (Trichoderma harzianum and Pleurotus ostreatus) exhibiting different typical morphologies (disperse mycelia and pellets) are discussed. PMID:25652005

  19. Cellular proliferation, cellular viability, and biocompatibility of HA-ZnO composites.

    PubMed

    Saha, Naresh; Dubey, Ashutosh K; Basu, Bikramjit

    2012-01-01

    One of the important issues in the development of hydroxyapatite (HA)-based biomaterials is the prosthetic infection, which limits wider use of monolithic HA despite superior cellular response. Recently, we reported that ZnO addition to HA can induce bactericidal property. It is therefore important to assess how ZnO addition influences the cytotoxicity property and cell adhesion/proliferation on HA-ZnO composite surfaces in vitro. In the above perspective, the objective of this study is to investigate the cell type and material composition dependent cellular proliferation and viability of pressureless sintered HA-ZnO composites. The combination of cell viability data as well as morphological observations of cultured human osteoblast-like SaOS2 cells and mouse fibroblast L929 cells suggests that HA-ZnO composites containing 10 Wt % or lower ZnO exhibit the ability to support cell adhesion and proliferation. Both SaOS2 and L929 cells exhibit extensive multidirectional network of actin cytoskeleton and cell flattening on the lower ZnO containing (≤10 Wt %) HA-ZnO composites. The in vitro results illustrate how variation in ZnO content can influence significantly the cell vitality, as evaluated using MTT biochemical assay. Also, the critical statistical analysis reveals that ZnO addition needs to be carefully tailored to ensure good in vitro cytocompatibility. The underlying reasons for difference in biological properties are analyzed. It is suggested that surface wettability as well as dissolution of ZnO, both contribute to the observed differences in cellular viability and proliferation. PMID:22102555

  20. Influence of imperfections on effective properties of cellular solids

    SciTech Connect

    Grenestedt, J.L.

    1998-12-31

    The mechanical properties of cellular solids, or solid foams, is affected by imperfections such as wavy distortions of cell walls, variations in cell wall thickness, non-uniform cell shape, etc. The present paper is focused mainly on elastic stiffnesses of closed cell cellular solids. A perfect model is first discussed and shown to predict the behavior of PVC foams well. However, this model over-estimates the stiffnesses of aluminum foams. The relatively poor properties of the aluminum foam are believed to be caused by imperfections in the cells. The main body of the paper focuses on modeling different kinds of imperfections, and analyzing their impact on foam properties.

  1. Poly(vinyl alcohol)/gelatin Hydrogels Cultured with HepG2 Cells as a 3D Model of Hepatocellular Carcinoma: A Morphological Study

    PubMed Central

    Moscato, Stefania; Ronca, Francesca; Campani, Daniela; Danti, Serena

    2015-01-01

    It has been demonstrated that three-dimensional (3D) cell culture models represent fundamental tools for the comprehension of cellular phenomena both for normal and cancerous tissues. Indeed, the microenvironment affects the cellular behavior as well as the response to drugs. In this study, we performed a morphological analysis on a hepatocarcinoma cell line, HepG2, grown for 24 days inside a bioartificial hydrogel composed of poly(vinyl alcohol) (PVA) and gelatin (G) to model a hepatocellular carcinoma (HCC) in 3D. Morphological features of PVA/G hydrogels were investigated, resulting to mimic the trabecular structure of liver parenchyma. A histologic analysis comparing the 3D models with HepG2 cell monolayers and tumor specimens was performed. In the 3D setting, HepG2 cells were viable and formed large cellular aggregates showing different morphotypes with zonal distribution. Furthermore, β-actin and α5β1 integrin revealed a morphotype-related expression; in particular, the frontline cells were characterized by a strong immunopositivity on a side border of their membrane, thus suggesting the formation of lamellipodia-like structures apt for migration. Based on these results, we propose PVA/G hydrogels as valuable substrates to develop a long term 3D HCC model that can be used to investigate important aspects of tumor biology related to migration phenomena. PMID:25590431

  2. Cellularized Bilayer Pullulan-Gelatin Hydrogel for Skin Regeneration.

    PubMed

    Nicholas, Mathew N; Jeschke, Marc G; Amini-Nik, Saeid

    2016-05-01

    Skin substitutes significantly reduce the morbidity and mortality of patients with burn injuries and chronic wounds. However, current skin substitutes have disadvantages related to high costs and inadequate skin regeneration due to highly inflammatory wounds. Thus, new skin substitutes are needed. By combining two polymers, pullulan, an inexpensive polysaccharide with antioxidant properties, and gelatin, a derivative of collagen with high water absorbency, we created a novel inexpensive hydrogel-named PG-1 for "pullulan-gelatin first generation hydrogel"-suitable for skin substitutes. After incorporating human fibroblasts and keratinocytes onto PG-1 using centrifugation over 5 days, we created a cellularized bilayer skin substitute. Cellularized PG-1 was compared to acellular PG-1 and no hydrogel (control) in vivo in a mouse excisional skin biopsy model using newly developed dome inserts to house the skin substitutes and prevent mouse skin contraction during wound healing. PG-1 had an average pore size of 61.69 μm with an ideal elastic modulus, swelling behavior, and biodegradability for use as a hydrogel for skin substitutes. Excellent skin cell viability, proliferation, differentiation, and morphology were visualized through live/dead assays, 5-bromo-2'-deoxyuridine proliferation assays, and confocal microscopy. Trichrome and immunohistochemical staining of excisional wounds treated with the cellularized skin substitute revealed thicker newly formed skin with a higher proportion of actively proliferating cells and incorporation of human cells compared to acellular PG-1 or control. Excisional wounds treated with acellular or cellularized hydrogels showed significantly less macrophage infiltration and increased angiogenesis 14 days post skin biopsy compared to control. These results show that PG-1 has ideal mechanical characteristics and allows ideal cellular characteristics. In vivo evidence suggests that cellularized PG-1 promotes skin regeneration and may

  3. The role of actin networks in cellular mechanosensing

    NASA Astrophysics Data System (ADS)

    Azatov, Mikheil

    behavior as in cancer metastasis. In addition to stiffness, the local geometry or topography of the surface has been shown to modulate the movement, morphology, and cytoskeletal organization of cells. However, the effect of topography on fluctuations of intracellular structures, which arise from motor driven activity on a viscoelastic actin network are not known. I have used nanofabricated substrates with parallel ridges to show that the cell shape, the actin cytoskeleton and focal adhesions all align along the direction of the ridges, exhibiting a biphasic dependence on the spacing between ridges. I further demonstrated that palladin bands along actin stress fibers undergo a complex diffusive motion with velocities aligned along the direction of ridges. These results provide insight into the mechanisms of cellular mechanosensing of the environment, suggesting a complex interplay between the actin cytoskeleton and cellular adhesions in coordinating cellular response to surface topography. Overall, this work has advanced our understanding of mechanisms that govern cellular responses to their physical environment.

  4. Microfluidic Electroporation for Cellular Analysis and Delivery

    PubMed Central

    Geng, Tao

    2013-01-01

    Electroporation is a simple yet powerful technique for breaching cell membrane barrier. The applications of electroporation can be generally divided into two categories: the release of intracellular proteins, nucleic acids and other metabolites for analysis and the delivery of exogenous reagents such as genes, drugs and nanoparticles with therapeutic purposes or for cellular manipulation. In this review, we go over the basic physics associated with cell electroporation and highlight recent technological advances on microfluidic platforms for conducting electroporation. Within the context of its working mechanism, we summarize the accumulated knowledge on how the parameters of electroporation affect its performance for various tasks. We discuss various strategies and designs for conducting electroporation at microscale and then focus on analysis of intracellular contents and delivery of exogenous agents as two major applications of the technique. Finally, an outlook for future applications of microfluidic electroporation in increasingly diverse utilities is presented. PMID:23917998

  5. Spatial game in cellular automaton evacuation model

    NASA Astrophysics Data System (ADS)

    von Schantz, Anton; Ehtamo, Harri

    2015-11-01

    For numerical simulations of crowd dynamics in an evacuation we need a computationally light environment, such as the cellular automaton model (CA). By choosing the right model parameters, different types of crowd behavior and collective effects can be produced. But the CA does not answer why, when, and how these different behaviors and collective effects occur. In this article, we present a model, where we couple a spatial evacuation game to the CA. In the game, an agent chooses its strategy by observing its neighbors' strategies. The game matrix changes with the distance to the exit as the evacuation conditions develop. In the resulting model, an agent's strategy choice alters the parameters that govern its behavior in the CA. Thus, with our model, we are able to simulate how evacuation conditions affect the behavior of the crowd. Also, we show that some of the collective effects observed in evacuations are a result of the simple game the agents play.

  6. Control of a neuronal morphology program by an RNA-binding zinc finger protein, Unkempt

    PubMed Central

    Zarnack, Kathi; Durak, Omer; Murphy, Elisabeth A.; Cheloufi, Sihem; Gonzalez, Dilenny M.; Teplova, Marianna; Curk, Tomaž; Zuber, Johannes; Patel, Dinshaw J.; Ule, Jernej; Luscombe, Nicholas M.; Tsai, Li-Huei; Walsh, Christopher A.

    2015-01-01

    Cellular morphology is an essential determinant of cellular function in all kingdoms of life, yet little is known about how cell shape is controlled. Here we describe a molecular program that controls the early morphology of neurons through a metazoan-specific zinc finger protein, Unkempt. Depletion of Unkempt in mouse embryos disrupts the shape of migrating neurons, while ectopic expression confers neuronal-like morphology to cells of different nonneuronal lineages. We found that Unkempt is a sequence-specific RNA-binding protein and identified its precise binding sites within coding regions of mRNAs linked to protein metabolism and trafficking. RNA binding is required for Unkempt-induced remodeling of cellular shape and is directly coupled to a reduced production of the encoded proteins. These findings link post-transcriptional regulation of gene expression with cellular shape and have general implications for the development and disease of multicellular organisms. PMID:25737280

  7. Control of a neuronal morphology program by an RNA-binding zinc finger protein, Unkempt.

    PubMed

    Murn, Jernej; Zarnack, Kathi; Yang, Yawei J; Durak, Omer; Murphy, Elisabeth A; Cheloufi, Sihem; Gonzalez, Dilenny M; Teplova, Marianna; Curk, Tomaž; Zuber, Johannes; Patel, Dinshaw J; Ule, Jernej; Luscombe, Nicholas M; Tsai, Li-Huei; Walsh, Christopher A; Shi, Yang

    2015-03-01

    Cellular morphology is an essential determinant of cellular function in all kingdoms of life, yet little is known about how cell shape is controlled. Here we describe a molecular program that controls the early morphology of neurons through a metazoan-specific zinc finger protein, Unkempt. Depletion of Unkempt in mouse embryos disrupts the shape of migrating neurons, while ectopic expression confers neuronal-like morphology to cells of different nonneuronal lineages. We found that Unkempt is a sequence-specific RNA-binding protein and identified its precise binding sites within coding regions of mRNAs linked to protein metabolism and trafficking. RNA binding is required for Unkempt-induced remodeling of cellular shape and is directly coupled to a reduced production of the encoded proteins. These findings link post-transcriptional regulation of gene expression with cellular shape and have general implications for the development and disease of multicellular organisms. PMID:25737280

  8. [Affective dependency].

    PubMed

    Scantamburlo, G; Pitchot, W; Ansseau, M

    2013-01-01

    Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy. PMID:23888587

  9. Coordination of Cellular Dynamics Contributes to Tooth Epithelium Deformations.

    PubMed

    Morita, Ritsuko; Kihira, Miho; Nakatsu, Yousuke; Nomoto, Yohei; Ogawa, Miho; Ohashi, Kazumasa; Mizuno, Kensaku; Tachikawa, Tetsuhiko; Ishimoto, Yukitaka; Morishita, Yoshihiro; Tsuji, Takashi

    2016-01-01

    The morphologies of ectodermal organs are shaped by appropriate combinations of several deformation modes, such as invagination and anisotropic tissue elongation. However, how multicellular dynamics are coordinated during deformation processes remains to be elucidated. Here, we developed a four-dimensional (4D) analysis system for tracking cell movement and division at a single-cell resolution in developing tooth epithelium. The expression patterns of a Fucci probe clarified the region- and stage-specific cell cycle patterns within the tooth germ, which were in good agreement with the pattern of the volume growth rate estimated from tissue-level deformation analysis. Cellular motility was higher in the regions with higher growth rates, while the mitotic orientation was significantly biased along the direction of tissue elongation in the epithelium. Further, these spatio-temporal patterns of cellular dynamics and tissue-level deformation were highly correlated with that of the activity of cofilin, which is an actin depolymerization factor, suggesting that the coordination of cellular dynamics via actin remodeling plays an important role in tooth epithelial morphogenesis. Our system enhances the understanding of how cellular behaviors are coordinated during ectodermal organogenesis, which cannot be observed from histological analyses. PMID:27588418

  10. MEMS capacitive force sensors for cellular and flight biomechanics.

    PubMed

    Sun, Yu; Nelson, Bradley J

    2007-03-01

    Microelectromechanical systems (MEMS) are playing increasingly important roles in facilitating biological studies. They are capable of providing not only qualitative but also quantitative information on the cellular, sub-cellular and organism levels, which is instrumental to understanding the fundamental elements of biological systems. MEMS force sensors with their high bandwidth and high sensitivity combined with their small size, in particular, have found a role in this domain, because of the importance of quantifying forces and their effect on the function and morphology of many biological structures. This paper describes our research in the development of MEMS capacitive force sensors that have already demonstrated their effectiveness in the areas of cell mechanics and Drosophila flight dynamics studies. PMID:18458415

  11. A morphological study of the changes in the ultrastructure of a bacterial biofilm disrupted by an ac corona discharge in air

    NASA Astrophysics Data System (ADS)

    Stepanova, Olga; Rybalchenko, Oksana; Astafiev, Alexander; Orlova, Olga; Kudryavtsev, Anatoly; Kapustina, Valentina

    2016-08-01

    The morphology of bacterial cells and biofilms subjected to a low frequency (˜105 Hz) ac (˜10-1 A) corona discharge was investigated using electron microscopy. A low-frequency ac corona discharge in air is shown to have a bactericidal and bacteriostatic effect on Escherichia coli M17 culture at both the cellular and population levels. Corona exposure inhibits the formation of a microbial community and results in the destruction of formed biofilms. This paper presents data on changes in the ultrastructure of cells and biofilms after corona treatment. Our results suggest that the E. coli M17 cells inside biofilms are affected with results similar to sub-lethal and lethal thermal exposure. Some of the biological aspects of colony and biofilm cells death are evaluated. Morphological changes in the ultrastructure of the biofilms under corona treatment are described. Our results indicate that the heating effect is the main factor responsible for the corona-induced inactivation of bacteria.

  12. Emergence of Large-Scale Cell Morphology and Movement from Local Actin Filament Growth Dynamics

    PubMed Central

    Lacayo, Catherine I; Pincus, Zachary; VanDuijn, Martijn M; Wilson, Cyrus A; Fletcher, Daniel A; Gertler, Frank B; Mogilner, Alex; Theriot, Julie A

    2007-01-01

    Variations in cell migration and morphology are consequences of changes in underlying cytoskeletal organization and dynamics. We investigated how these large-scale cellular events emerge as direct consequences of small-scale cytoskeletal molecular activities. Because the properties of the actin cytoskeleton can be modulated by actin-remodeling proteins, we quantitatively examined how one such family of proteins, enabled/vasodilator-stimulated phosphoprotein (Ena/VASP), affects the migration and morphology of epithelial fish keratocytes. Keratocytes generally migrate persistently while exhibiting a characteristic smooth-edged “canoe” shape, but may also exhibit less regular morphologies and less persistent movement. When we observed that the smooth-edged canoe keratocyte morphology correlated with enrichment of Ena/VASP at the leading edge, we mislocalized and overexpressed Ena/VASP proteins and found that this led to changes in the morphology and movement persistence of cells within a population. Thus, local changes in actin filament dynamics due to Ena/VASP activity directly caused changes in cell morphology, which is coupled to the motile behavior of keratocytes. We also characterized the range of natural cell-to-cell variation within a population by using measurable morphological and behavioral features—cell shape, leading-edge shape, filamentous actin (F-actin) distribution, cell speed, and directional persistence—that we have found to correlate with each other to describe a spectrum of coordinated phenotypes based on Ena/VASP enrichment at the leading edge. This spectrum stretched from smooth-edged, canoe-shaped keratocytes—which had VASP highly enriched at their leading edges and migrated fast with straight trajectories—to more irregular, rounder cells migrating slower with less directional persistence and low levels of VASP at their leading edges. We developed a mathematical model that accounts for these coordinated cell-shape and behavior

  13. Toxicity of Functional Nano-Micro Zinc Oxide Tetrapods: Impact of Cell Culture Conditions, Cellular Age and Material Properties

    PubMed Central

    Papavlassopoulos, Heike; Mishra, Yogendra K.; Kaps, Sören; Paulowicz, Ingo; Abdelaziz, Ramzy; Elbahri, Mady; Maser, Edmund; Adelung, Rainer; Röhl, Claudia

    2014-01-01

    With increasing production and applications of nanostructured zinc oxide, e.g., for biomedical and consumer products, the question of safety is getting more and more important. Different morphologies of zinc oxide structures have been synthesized and accordingly investigated. In this study, we have particularly focused on nano-micro ZnO tetrapods (ZnO-T), because their large scale fabrication has been made possible by a newly introduced flame transport synthesis approach which will probably lead to several new applications. Moreover, ZnO-T provide a completely different morphology then classical spherical ZnO nanoparticles. To get a better understanding of parameters that affect the interactions between ZnO-T and mammalian cells, and thus their biocompatibility, we have examined the impact of cell culture conditions as well as of material properties on cytotoxicity. Our results demonstrate that the cell density of fibroblasts in culture along with their age, i.e., the number of preceding cell divisions, strongly affect the cytotoxic potency of ZnO-T. Concerning the material properties, the toxic potency of ZnO-T is found to be significantly lower than that of spherical ZnO nanoparticles. Furthermore, the morphology of the ZnO-T influenced cellular toxicity in contrast to surface charges modified by UV illumination or O2 treatment and to the material age. Finally, we have observed that direct contact between tetrapods and cells increases their toxicity compared to transwell culture models which allow only an indirect effect via released zinc ions. The results reveal several parameters that can be of importance for the assessment of ZnO-T toxicity in cell cultures and for particle development. PMID:24454775

  14. Thermodynamics of cellular statistical inference

    NASA Astrophysics Data System (ADS)

    Lang, Alex; Fisher, Charles; Mehta, Pankaj

    2014-03-01

    Successful organisms must be capable of accurately sensing the surrounding environment in order to locate nutrients and evade toxins or predators. However, single cell organisms face a multitude of limitations on their accuracy of sensing. Berg and Purcell first examined the canonical example of statistical limitations to cellular learning of a diffusing chemical and established a fundamental limit to statistical accuracy. Recent work has shown that the Berg and Purcell learning limit can be exceeded using Maximum Likelihood Estimation. Here, we recast the cellular sensing problem as a statistical inference problem and discuss the relationship between the efficiency of an estimator and its thermodynamic properties. We explicitly model a single non-equilibrium receptor and examine the constraints on statistical inference imposed by noisy biochemical networks. Our work shows that cells must balance sample number, specificity, and energy consumption when performing statistical inference. These tradeoffs place significant constraints on the practical implementation of statistical estimators in a cell.

  15. Optofluidic Detection for Cellular Phenotyping

    PubMed Central

    Tung, Yi-Chung; Huang, Nien-Tsu; Oh, Bo-Ram; Patra, Bishnubrata; Pan, Chi-Chun; Qiu, Teng; Paul, K. Chu; Zhang, Wenjun; Kurabayashi, Katsuo

    2012-01-01

    Quantitative analysis of the output of processes and molecular interactions within a single cell is highly critical to the advancement of accurate disease screening and personalized medicine. Optical detection is one of the most broadly adapted measurement methods in biological and clinical assays and serves cellular phenotyping. Recently, microfluidics has obtained increasing attention due to several advantages, such as small sample and reagent volumes, very high throughput, and accurate flow control in the spatial and temporal domains. Optofluidics, which is the attempt to integrate optics with microfluidic, shows great promise to enable on-chip phenotypic measurements with high precision, sensitivity, specificity, and simplicity. This paper reviews the most recent developments of optofluidic technologies for cellular phenotyping optical detection. PMID:22854915

  16. Hox Targets and Cellular Functions

    PubMed Central

    Sánchez-Herrero, Ernesto

    2013-01-01

    Hox genes are a group of genes that specify structures along the anteroposterior axis in bilaterians. Although in many cases they do so by modifying a homologous structure with a different (or no) Hox input, there are also examples of Hox genes constructing new organs with no homology in other regions of the body. Hox genes determine structures though the regulation of targets implementing cellular functions and by coordinating cell behavior. The genetic organization to construct or modify a certain organ involves both a genetic cascade through intermediate transcription factors and a direct regulation of targets carrying out cellular functions. In this review I discuss new data from genome-wide techniques, as well as previous genetic and developmental information, to describe some examples of Hox regulation of different cell functions. I also discuss the organization of genetic cascades leading to the development of new organs, mainly using Drosophila melanogaster as the model to analyze Hox function. PMID:24490109

  17. Peroxisome Metabolism and Cellular Aging

    PubMed Central

    Titorenko, Vladimir I.; Terlecky, Stanley R.

    2010-01-01

    The essential role of peroxisomes in fatty acid oxidation, anaplerotic metabolism, and hydrogen peroxide turnover is well established. Recent findings suggest these and other related biochemical processes governed by the organelle may also play a critical role in regulating cellular aging. The goal of this review is to summarize and integrate into a model, the evidence that peroxisome metabolism actually helps define the replicative and chronological age of a eukaryotic cell. In this model, peroxisomal reactive oxygen species (ROS) are seen as altering organelle biogenesis and function, and eliciting changes in the dynamic communication networks that exist between peroxisomes and other cellular compartments. At low levels, peroxisomal ROS activate an anti-aging program in the cell; at concentrations beyond a specific threshold, a pro-aging course is triggered. PMID:21083858

  18. Cellular solidification of transparent monotectics

    NASA Technical Reports Server (NTRS)

    Kaulker, W. F.

    1986-01-01

    Understanding how liquid phase particles are engulfed or pushed during freezing of a monotectic is addressed. The additional complication is that the solid-liquid interface is nonplanar due to constitutional undercooling. Some evidence of particle pushing where the particles are the liquid phase of the montectic was already observed. Cellular freezing of the succinonitrile-glycerol system also occurred. Only a few compositions were tested at that time. The starting materials were not especially pure so that cellular interface observed was likely due to the presence of unkown impurities, the major portion of which was water. Topics addressed include: the effort of modeling the particle pushing process using the computer, establishing an apparatus for the determination of phase diagrams, and the measurement of the temperature gradients with a specimen which will solidify on the temperature gradient microscope stage.

  19. Xtoys: Cellular automata on xwindows

    SciTech Connect

    Creutz, M.

    1995-08-15

    Xtoys is a collection of xwindow programs for demonstrating simulations of various statistical models. Included are xising, for the two dimensional Ising model, xpotts, for the q-state Potts model, xautomalab, for a fairly general class of totalistic cellular automata, xsand, for the Bak-Tang-Wiesenfield model of self organized criticality, and xfires, a simple forest fire simulation. The programs should compile on any machine supporting xwindows.

  20. Fluorescent Proteins in Cellular Organelles: Serious Pitfalls and Some Solutions

    PubMed Central

    Costantini, Lindsey M.

    2013-01-01

    Fluorescent proteins (FPs) have been powerful tools for cell biologists for over 15 years. The large variety of FPs available rarely comes with an instruction manual or a warning label. The potential pitfalls of the use of FPs in cellular organelles represent a significant concern for investigators. FPs generally did not evolve in the often distinctive physicochemical environments of subcellular organelles. In organelles, FPs can misfold, go dark, and even distort organelle morphology. In this minireview, we describe the issues associated with FPs in organelles and provide solutions to enable investigators to better exploit FP technology in cells. PMID:23971632

  1. Emulating fire propagation by using cellular nonlinear networks

    NASA Astrophysics Data System (ADS)

    Buscarino, A.; Fortuna, L.; Frasca, M.; Xibilia, M. G.

    2012-09-01

    In this paper a new approach based on Cellular Nonlinear Networks (CNNs) for modeling the diffusion of forest fires is presented. Based on a model relying on an hyperbolic reaction-diffusion equation, the proposed approach exploits the peculiarity of CNNs allowing the investigation of different types of forest fires, also considering specific morphological characteristics of the terrain and the presence of external perturbations like wind flows. Results show the emergence of particular phenomena really observed in wildfires, allowing to assess the validity of the approach.

  2. Overexpression of the microRNA miR-433 promotes resistance to paclitaxel through the induction of cellular senescence in ovarian cancer cells

    PubMed Central

    Weiner-Gorzel, Karolina; Dempsey, Eugene; Milewska, Malgorzata; McGoldrick, Aloysius; Toh, Valerie; Walsh, Aoibheann; Lindsay, Sinead; Gubbins, Luke; Cannon, Aoife; Sharpe, Daniel; O'Sullivan, Jacintha; Murphy, Madeline; Madden, Stephen F; Kell, Malcolm; McCann, Amanda; Furlong, Fiona

    2015-01-01

    Annually, ovarian cancer (OC) affects 240,000 women worldwide and is the most lethal gynecological malignancy. High-grade serous OC (HGSOC) is the most common and aggressive OC subtype, characterized by widespread genome changes and chromosomal instability and is consequently poorly responsive to chemotherapy treatment. The objective of this study was to investigate the role of the microRNA miR-433 in the cellular response of OC cells to paclitaxel treatment. We show that stable miR-433 expression in A2780 OC cells results in the induction of cellular senescence demonstrated by morphological changes, downregulation of phosphorylated retinoblastoma (p-Rb), and an increase in β-galactosidase activity. Furthermore, in silico analysis identified four possible miR-433 target genes associated with cellular senescence: cyclin-dependent kinase 6 (CDK6), MAPK14, E2F3, and CDKN2A. Mechanistically, we demonstrate that downregulation of p-Rb is attributable to a miR-433-dependent downregulation of CDK6, establishing it as a novel miR-433 associated gene. Interestingly, we show that high miR-433 expressing cells release miR-433 into the growth media via exosomes which in turn can induce a senescence bystander effect. Furthermore, in relation to a chemotherapeutic response, quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that only PEO1 and PEO4 OC cells with the highest miR-433 expression survive paclitaxel treatment. Our data highlight how the aberrant expression of miR-433 can adversely affect intracellular signaling to mediate chemoresistance in OC cells by driving cellular senescence. PMID:25684390

  3. Competitive potential of cellular mobile telecommunications

    SciTech Connect

    Ware, H.

    1983-02-03

    The Federal Communications Commission (FCC) has recently issued rules for the commercial operation of a telecommunications technology not previously in commercial use: the cellular mobile radio. The author has carefully considered the potential for competition between cellular systems and for competition between cellular radio and alternative communications technologies under the regulatory scheme which has been adopted by the FCC. He finds that competition between cellular and wire-line services can be viable if cellular cost and demand data are carefully tracked to avoid market congestion and if cellular or other techniques are not allowed to undercut selected local exchange rates.

  4. Quantification of Dynamic Morphological Drug Responses in 3D Organotypic Cell Cultures by Automated Image Analysis

    PubMed Central

    Härmä, Ville; Schukov, Hannu-Pekka; Happonen, Antti; Ahonen, Ilmari; Virtanen, Johannes; Siitari, Harri; Åkerfelt, Malin; Lötjönen, Jyrki; Nees, Matthias

    2014-01-01

    Glandular epithelial cells differentiate into complex multicellular or acinar structures, when embedded in three-dimensional (3D) extracellular matrix. The spectrum of different multicellular morphologies formed in 3D is a sensitive indicator for the differentiation potential of normal, non-transformed cells compared to different stages of malignant progression. In addition, single cells or cell aggregates may actively invade the matrix, utilizing epithelial, mesenchymal or mixed modes of motility. Dynamic phenotypic changes involved in 3D tumor cell invasion are sensitive to specific small-molecule inhibitors that target the actin cytoskeleton. We have used a panel of inhibitors to demonstrate the power of automated image analysis as a phenotypic or morphometric readout in cell-based assays. We introduce a streamlined stand-alone software solution that supports large-scale high-content screens, based on complex and organotypic cultures. AMIDA (Automated Morphometric Image Data Analysis) allows quantitative measurements of large numbers of images and structures, with a multitude of different spheroid shapes, sizes, and textures. AMIDA supports an automated workflow, and can be combined with quality control and statistical tools for data interpretation and visualization. We have used a representative panel of 12 prostate and breast cancer lines that display a broad spectrum of different spheroid morphologies and modes of invasion, challenged by a library of 19 direct or indirect modulators of the actin cytoskeleton which induce systematic changes in spheroid morphology and differentiation versus invasion. These results were independently validated by 2D proliferation, apoptosis and cell motility assays. We identified three drugs that primarily attenuated the invasion and formation of invasive processes in 3D, without affecting proliferation or apoptosis. Two of these compounds block Rac signalling, one affects cellular cAMP/cGMP accumulation. Our approach supports

  5. Influence of prepolymer composition on polyurethane morphology

    NASA Astrophysics Data System (ADS)

    Krishnamoorthy, Jayaraman; Jeong, Young Gyu; Hashida, Tomoko; Hsu, Shaw Ling

    2004-03-01

    Polyurethane chemistry is one of the most studied subjects. Yet many aspects remain unexplained. Polyurethanes are synthesized by the reaction of diisocyanate with diol in the presence of nucleophilic catalysts. Polyurethane prepolymers are obtained by reacting the polyester diol / polyether diol with diisocyanate, with [NCO] / [OH] > 1, resulting in isocyanate-terminated polyester/polyether mixture. Prepolymers thus synthesized can be cured at a later stage to realize various morphologies and structures. Though the initial composition and the final morphology are known, little is known about the intermediate prepolymer mixture. Due to the different reactivity of primary and secondary hydroxyl groups in the polyester and polyether towards isocyanate, prepolymer has a non-random distribution in terms of composition as blends and copolymers. Our aim is to characterize the prepolymer by different techniques and study how the different prepolymer composition, with varying polyester and polyether ratio, affects the morphology and phase separation kinetics of the final product.

  6. Juvenile morphology in baleen whale phylogeny

    NASA Astrophysics Data System (ADS)

    Tsai, Cheng-Hsiu; Fordyce, R. Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  7. Controlled morphology of biodegradable polymer blends

    NASA Astrophysics Data System (ADS)

    Buddhiranon, Sasiwimon; Kyu, Thein

    2009-03-01

    Phase diagrams of biodegradable polymer blends containing poly(ɛ-caprolactone) (PCL) and poly(d,l-lactic acid) (PDLLA) having two different molecular weights were established by means of cloud point measurement and differential scanning calorimetry. Subsequently, the theoretical phase diagram was calculated self-consistently based on the combination of Flory-Huggins free energy for liquid-liquid phase separation and phase field free energy for crystal solidification. The phase diagrams thus obtained were LCST type or hour-glass type, which depended on molecular weight of PDLLA utilized. Guided by the phase diagram, the emerged morphology was determined as a function of blend concentration and temperature. It appears that the morphology control is feasible that ultimately affects the end-use property of PCL/PDLLA blends. A wide variety of morphology of biodegradable polymer may be developed with the porous structure and pore size to control scaffold porosity and the rate of drug delivery.

  8. Juvenile morphology in baleen whale phylogeny

    NASA Astrophysics Data System (ADS)

    Tsai, Cheng-Hsiu; Fordyce, R. Ewan

    2014-08-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  9. Outline of Polish Morphology.

    ERIC Educational Resources Information Center

    Bidwell, Charles E.

    This volume, one of a series of concise but relatively exhaustive descriptions of the grammatical structures of the principal standard Slavic languages, contains an outline of Polish morphology. The four major sections are morphophonemics, nominal inflection, the Polish verb (Part 1--stem alternation and conjugation, and the Polish verb (Part…

  10. Eutectic-Alloy Morphology

    NASA Technical Reports Server (NTRS)

    Pirich, R. G.; Poit, W. J.

    1985-01-01

    Deviation in controlled-rod eutectic morphology anticipated for diffusion only crystal growth characterized at low solidification velocities. Naturally induced, gravity-related convective instabilities result in nonalined irregularly dispersed fibers or platelets. Lower solidification limit for controlled growth Bi/Mn alloys is 1 centimeter/ hour.

  11. OUTLINE OF UKRAINIAN MORPHOLOGY.

    ERIC Educational Resources Information Center

    BIDWELL, CHARLES E.

    SIMILAR IN FORMAT TO THE AUTHOR'S "OUTLINE OF BIELORUSSIAN MORPHOLOGY," THIS STRUCTURALLY-ORIENTED TREATMENT OF UKRAINIAN INCLUDES SECTIONS ON --(1) PHONOLOGY, (2) MORPHOPHONEMIC ALTERNATIONS, (3) THE NOUN, (4) THE ADJECTIVE, (5) PRONOUNS, (6) NUMERALS, AND (7) THE VERB. THE AUTHOR BASES HIS FINDINGS ON PUBLISHED HANDBOOKS AND GRAMMARS AS WELL AS…

  12. Cellular Instabilities and Self-Acceleration of Expanding Spherical Flames

    NASA Technical Reports Server (NTRS)

    Law, C. K.; Kwon, O. C.

    2003-01-01

    In the present investigation we aim to provide experimental information on and thereby understanding of the generation and propagation of spark-ignited, outwardly propagating cellular flames, with three major focuses. The first is to unambiguously demonstrate the influence of the four most important parameters in inducing hydrodynamic and diffusional-thermal cellularities, namely thermal expansion, flame thickness, non-unity Lewis number, and global activation energy. The second is to investigate the critical state for the onset of cellularity for the stretch-affected, expanding flame. The third is to identify and consequently quantify the phenomena of self-acceleration and possibly auto-turbulization of cellular flames. Due to space limitation the effects of activation energy and the critical state for the onset of cellularity will not be discussed herein. Experiments were conducted using C3H8-air and H2-O2-N2 mixtures for their opposite influences of non-equidiffusivity. The additional system parameters varied were the chamber pressure (p) and the mixture composition including the equivalence ratio (phi). From a sequence of the flame images we can assess the propensity of cell formation, and determine the instantaneous flame radius (R), the flame propagation rate, the global stretch rate experienced by the flame, the critical flame radius at which cells start to grow, and the average cell size.

  13. Mitochondrial Variability as a Source of Extrinsic Cellular Noise

    PubMed Central

    Johnston, Iain G.; Gaal, Bernadett; Neves, Ricardo Pires das; Enver, Tariq; Iborra, Francisco J.; Jones, Nick S.

    2012-01-01

    We present a study investigating the role of mitochondrial variability in generating noise in eukaryotic cells. Noise in cellular physiology plays an important role in many fundamental cellular processes, including transcription, translation, stem cell differentiation and response to medication, but the specific random influences that affect these processes have yet to be clearly elucidated. Here we present a mechanism by which variability in mitochondrial volume and functionality, along with cell cycle dynamics, is linked to variability in transcription rate and hence has a profound effect on downstream cellular processes. Our model mechanism is supported by an appreciable volume of recent experimental evidence, and we present the results of several new experiments with which our model is also consistent. We find that noise due to mitochondrial variability can sometimes dominate over other extrinsic noise sources (such as cell cycle asynchronicity) and can significantly affect large-scale observable properties such as cell cycle length and gene expression levels. We also explore two recent regulatory network-based models for stem cell differentiation, and find that extrinsic noise in transcription rate causes appreciable variability in the behaviour of these model systems. These results suggest that mitochondrial and transcriptional variability may be an important mechanism influencing a large variety of cellular processes and properties. PMID:22412363

  14. Role of Cellular Magnesium in Human Diseases

    PubMed Central

    Long, Samantha; Romani, Andrea MP

    2015-01-01

    Magnesium is required for many of the major organs to function and plays a crucial role in human and mammalian physiology. Magnesium is essential for the structure of bones and teeth, acts as a cofactor for more than 300 enzymes in the body, including binding to ATP for kinase reactions, and affects permeability of excitable membranes and neuromuscular transmission. Despite these essential roles, much is still unknown about magnesium physiology and homeostasis. Currently, nutritionists believe that the general population intakes insufficient magnesium daily through the diet. The effects of magnesium deficiency are, for the most part undetected, and simple, widespread assessments of magnesium intake remain unavailable for humans. Many of the patients admitted to hospitals or medical care facilities are unaware of their low magnesium levels. Moreover, because magnesium is predominantly an intracellular cation (>99%), serum magnesium levels remain a poor predictor of tissue magnesium content and availability. This review will discuss the effects of magnesium deficiency in various pathologies affecting the human population. The underlying causes for magnesium depletion in major physiological systems will be examined along with the involved signaling pathways and the main roles of magnesium homeostasis. Where possible (e.g. alcoholism), the implications of administering supplemental magnesium will be discussed. Ultimately, this review will advocate for the necessity of identifying easy and reproducible methods to assess serum and cellular magnesium levels and to identify magnesium deficiency in order to alleviate related pathological conditions. PMID:25839058

  15. Direct ribosomal binding by a cellular inhibitor of translation

    PubMed Central

    Colón-Ramos, Daniel A; Shenvi, Christina L; Weitzel, Douglas H; Gan, Eugene C; Matts, Robert; Cate, Jamie; Kornbluth, Sally

    2009-01-01

    During apoptosis and under conditions of cellular stress, several signaling pathways promote inhibition of cap-dependent translation while allowing continued translation of specific messenger RNAs encoding regulatory and stress-response proteins. We report here that the apoptotic regulator Reaper inhibits protein synthesis by binding directly to the 40S ribosomal subunit. This interaction does not affect either ribosomal association of initiation factors or formation of 43S or 48S complexes. Rather, it interferes with late initiation events upstream of 60S subunit joining, apparently modulating start-codon recognition during scanning. CrPV IRES–driven translation, involving direct ribosomal recruitment to the start site, is relatively insensitive to Reaper. Thus, Reaper is the first known cellular ribosomal binding factor with the potential to allow selective translation of mRNAs initiating at alternative start codons or from certain IRES elements. This function of Reaper may modulate gene expression programs to affect cell fate. PMID:16429152

  16. Cellular immune responses to HIV

    NASA Astrophysics Data System (ADS)

    McMichael, Andrew J.; Rowland-Jones, Sarah L.

    2001-04-01

    The cellular immune response to the human immunodeficiency virus, mediated by T lymphocytes, seems strong but fails to control the infection completely. In most virus infections, T cells either eliminate the virus or suppress it indefinitely as a harmless, persisting infection. But the human immunodeficiency virus undermines this control by infecting key immune cells, thereby impairing the response of both the infected CD4+ T cells and the uninfected CD8+ T cells. The failure of the latter to function efficiently facilitates the escape of virus from immune control and the collapse of the whole immune system.

  17. Quantum cellular automata without particles

    NASA Astrophysics Data System (ADS)

    Meyer, David A.; Shakeel, Asif

    2016-01-01

    Quantum cellular automata (QCA) constitute space and time homogeneous discrete models for quantum field theories (QFTs). Although QFTs are defined without reference to particles, computations are done in terms of Feynman diagrams, which are explicitly interpreted in terms of interacting particles. Similarly, the easiest QCA to construct are quantum lattice gas automata (QLGA). A natural question then is, which QCA are not QLGA? Here we construct a nontrivial example of such a QCA; it provides a simple model in 1 +1 dimensions with no particle interpretation at the scale where the QCA dynamics are homogeneous.

  18. Universal map for cellular automata

    NASA Astrophysics Data System (ADS)

    García-Morales, V.

    2012-08-01

    A universal map is derived for all deterministic 1D cellular automata (CAs) containing no freely adjustable parameters and valid for any alphabet size and any neighborhood range (including non-symmetrical neighborhoods). The map can be extended to an arbitrary number of dimensions and topologies and to arbitrary order in time. Specific CA maps for the famous Conway's Game of Life and Wolfram's 256 elementary CAs are given. An induction method for CAs, based in the universal map, allows mathematical expressions for the orbits of a wide variety of elementary CAs to be systematically derived.

  19. Therapeutic cloning and cellular reprogramming.

    PubMed

    Rodriguez, Ramon M; Ross, Pablo J; Cibelli, Jose B

    2012-01-01

    Embryonic stem cells are capable of differentiating into any cell-type present in an adult organism, and constitute a renewable source of tissue for regenerative therapies. The transplant of allogenic stem cells is challenging due to the risk of immune rejection. Nevertheless, somatic cell reprogramming techniques allow the generation of isogenic embryonic stem cells, genetically identical to the patient. In this chapter we will discuss the cellular reprogramming techniques in the context of regenerative therapy and the biological and technical barriers that they will need to overcome before clinical use. PMID:22457116

  20. Symmetry analysis of cellular automata

    NASA Astrophysics Data System (ADS)

    García-Morales, V.

    2013-01-01

    By means of B-calculus [V. García-Morales, Phys. Lett. A 376 (2012) 2645] a universal map for deterministic cellular automata (CAs) has been derived. The latter is shown here to be invariant upon certain transformations (global complementation, reflection and shift). When constructing CA rules in terms of rules of lower range a new symmetry, “invariance under construction” is uncovered. Modular arithmetic is also reformulated within B-calculus and a new symmetry of certain totalistic CA rules, which calculate the Pascal simplices modulo an integer number p, is then also uncovered.

  1. Primitive control of cellular metabolism

    NASA Technical Reports Server (NTRS)

    Mitz, M. A.

    1974-01-01

    It is pointed out that control substances must have existed from the earliest times in the evolution of life and that the same control mechanisms must exist today. The investigation reported is concerned with the concept that carbon dioxide is a primitive regulator of cell function. The effects of carbon dioxide on cellular materials are examined, taking into account questions of solubilization, dissociation, changes of charge, stabilization, structural changes, wettability, the exclusion of other gases, the activation of compounds, changes in plasticity, and changes in membrane permeability.

  2. The Cellular Basis of Aging

    PubMed Central

    Scoggin, Charles H.

    1981-01-01

    Normal cells have only a finite life span before they die. The process known as aging may occur as a result of continued damage to the cell or as a result of expression of predetermined information within the genetic structure of the cell. Both processes lead to progressive cellular dysfunction which is evidenced by the organs of the body as aging. By understanding how individual cells age we will gain insight into how the body as a whole ages. The impact of such knowledge on science and society is a matter of both conjecture and concern. PMID:7336718

  3. Protein accounting in the cellular economy

    PubMed Central

    Vázquez-Laslop, Nora; Mankin, Alexander S.

    2014-01-01

    Knowing the copy number of cellular proteins is critical for understanding cell physiology. By being able to measure the absolute synthesis rates of the majority of cellular proteins, Li et al. (2014) gain insights into key aspects of translation regulation and fundamental principles of cellular strategies to adjust protein synthesis according to the needs. PMID:24766801

  4. Protein accounting in the cellular economy.

    PubMed

    Vázquez-Laslop, Nora; Mankin, Alexander S

    2014-04-24

    Knowing the copy number of cellular proteins is critical for understanding cell physiology. By being able to measure the absolute synthesis rates of the majority of cellular proteins, Li et al. gain insights into key aspects of translation regulation and fundamental principles of cellular strategies to adjust protein synthesis according to the functional needs. PMID:24766801

  5. Mito-Morphosis: Mitochondrial Fusion, Fission, and Cristae Remodeling as Key Mediators of Cellular Function.

    PubMed

    Pernas, Lena; Scorrano, Luca

    2016-01-01

    Permanent residency in the eukaryotic cell pressured the prokaryotic mitochondrial ancestor to strategize for intracellular living. Mitochondria are able to autonomously integrate and respond to cellular cues and demands by remodeling their morphology. These processes define mitochondrial dynamics and inextricably link the fate of the mitochondrion and that of the host eukaryote, as exemplified by the human diseases that result from mutations in mitochondrial dynamics proteins. In this review, we delineate the architecture of mitochondria and define the mechanisms by which they modify their shape. Key players in these mechanisms are discussed, along with their role in manipulating mitochondrial morphology during cellular action and development. Throughout, we highlight the evolutionary context in which mitochondrial dynamics emerged and consider unanswered questions whose dissection might lead to mitochondrial morphology-based therapies. PMID:26667075

  6. Cellular bioenergetics of guanidinoacetic acid: the role of mitochondria.

    PubMed

    Ostojic, Sergej M

    2015-10-01

    Guanidinoacetic acid (GAA) is a natural precursor of creatine, and a possible substrate for the creatine kinase (CK) enzyme system, serving as a creatine mimetic. Its direct role in cellular bioenergetics has been confirmed in several studies, however GAA utilization by CK seems to be a second-rate as compared to creatine, and compartment-dependent. Here we discuss various factors that might affect GAA use in high-energy phosphoryl transfer in the cytosol and mitochondria. PMID:26255041

  7. Morphological stability of sapphire crystallization front

    NASA Astrophysics Data System (ADS)

    Baranov, V. V.; Nizhankovskyi, S. V.

    2016-03-01

    The main factors and specificity of growth conditions for sapphire and Ti:sapphire crystals, which affect the morphological stability of the crystal-melt interface, have been investigated with allowance for the concentration and radiative melt supercooling. It is shown that the critical sapphire growth rate is determined to a great extent by the optical transparency of the melt and the mixing conditions near the crystallization front.

  8. Volcanology and morphology

    NASA Technical Reports Server (NTRS)

    Bryan, W. B.

    1976-01-01

    Apollo 15 photographs of the southern parts of Serenitatis and Imbrium were used for a study of the morphology and distribution of wrinkle ridges. Volcanic and structural features along the south margin of Serenitatis were also studied, including the Dawes basalt cinder cones. Volcanic and structural features in crater Aitken were investigated as well. Study of crater Goclenius showed a close relationship between morphology of the impact crater and grabens which tend to parallel directions of the lunar grid. Similar trends were observed in the walls of crater Tsiolkovsky and other linear structures. Small craters of possible volcanic origin were also studied. Possible cinder cones were found associated with the Dawes basalt and in the floor of craters Aitken and Goclenius. Small pit craters were observed in the floors of these craters. Attempts were made to obtain contour maps of specific small features and to compare Orbiter and Apollo photographs to determine short term changes associated with other processes.

  9. Diamagnetic levitation causes changes in the morphology, cytoskeleton, and focal adhesion proteins expression in osteocytes.

    PubMed

    Qian, A R; Wang, L; Gao, X; Zhang, W; Hu, L F; Han, J; Li, J B; Di, S M; Shang, Peng

    2012-01-01

    Diamagnetic levitation technology is a novel simulated weightless technique and has recently been applied in life-science research. We have developed a superconducting magnet platform with large gradient high magnetic field (LG-HMF), which can provide three apparent gravity levels, namely, μg (diamagnetic levitation), 1g, and 2g for diamagnetic materials. In this study, the effects of LG-HMF on the activity, morphology, and cytoskeleton (actin filament, microtubules, and vimentin intermediate filaments) in osteocyte - like cell line MLO-Y4 were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods, hematoxylin-eosin (HE) staining, and laser scanning confocal microscopy (LSCM), respectively. The changes induced by LG-HMF in distribution and expression of focal adhesion (FA) proteins, including vinculin, paxillin, and talin in MLO-Y4 were determined by LSCM and Western blotting. The results showed that LG-HMF produced by superconducting magnet had no lethal effects on MLO-Y4. Compared to control, diamagnetic levitation (μg) affected MLO-Y4 morphology, nucleus size, cytoskeleton architecture, and FA proteins distribution and expression. The study indicates that osteocytes are sensitive to altered gravity and FA proteins (vinculin, paxillin, and talin) may be involved in osteocyte mechanosensation. The diamagnetic levitation may be a novel ground-based space-gravity simulator and can be used for biological experiment at cellular level. PMID:21216704

  10. The morphological evolution of the axial structure and the curved columnar grain in the weld

    NASA Astrophysics Data System (ADS)

    Han, Rihong; Lu, Shanping; Dong, Wenchao; Li, Dianzhong; Li, Yiyi

    2015-12-01

    The competitive growth of microstructures in the entire weld pool for both the Al-Cu alloy and the pure aluminum was simulated by the cellular automata method to comparatively investigate the micro-mechanisms for the morphological evolution of the axial structure and the curved columnar grain in the weld. The competitive mechanism of grains during the epitaxial growth and the morphological evolution of the grain structure in the weld with various welding speeds were studied. The results indicate that both the thermal conditions and the solidification characteristic of the weld metal exert an important influence on the grain competition and the resulting structure in the weld. For the Al-Cu alloy, the dendritic structure with a large S/L interface curvature appears during the epitaxial growth. The preferential orientation affects the competition result obviously. Owing to the anisotropic growth kinetics, the straight axial structure forms at low welding speeds. With the increase of the welding speed, the width of the axial region decreases and eventually disappears. For the pure aluminum, the S/L interface during the epitaxial growth is planar, and the grain competition is controlled by the thermal conditions completely. The columnar grains curve gradually to follow the highest temperature gradient direction at low welding speeds and become straight at high welding speeds.

  11. Cellular senescence and protein degradation

    PubMed Central

    Deschênes-Simard, Xavier; Lessard, Frédéric; Gaumont-Leclerc, Marie-France; Bardeesy, Nabeel; Ferbeyre, Gerardo

    2014-01-01

    Autophagy and the ubiquitin–proteasome pathway (UPP) are the major protein degradation systems in eukaryotic cells. Whereas the former mediate a bulk nonspecific degradation, the UPP allows a rapid degradation of specific proteins. Both systems have been shown to play a role in tumorigenesis, and the interest in developing therapeutic agents inhibiting protein degradation is steadily growing. However, emerging data point to a critical role for autophagy in cellular senescence, an established tumor suppressor mechanism. Recently, a selective protein degradation process mediated by the UPP was also shown to contribute to the senescence phenotype. This process is tightly regulated by E3 ubiquitin ligases, deubiquitinases, and several post-translational modifications of target proteins. Illustrating the complexity of UPP, more than 600 human genes have been shown to encode E3 ubiquitin ligases, a number which exceeds that of the protein kinases. Nevertheless, our knowledge of proteasome-dependent protein degradation as a regulated process in cellular contexts such as cancer and senescence remains very limited. Here we discuss the implications of protein degradation in senescence and attempt to relate this function to the protein degradation pattern observed in cancer cells. PMID:24866342

  12. Micromechanics of cellularized biopolymer networks

    PubMed Central

    Jones, Christopher A. R.; Cibula, Matthew; Feng, Jingchen; Krnacik, Emma A.; McIntyre, David H.; Levine, Herbert; Sun, Bo

    2015-01-01

    Collagen gels are widely used in experiments on cell mechanics because they mimic the extracellular matrix in physiological conditions. Collagen gels are often characterized by their bulk rheology; however, variations in the collagen fiber microstructure and cell adhesion forces cause the mechanical properties to be inhomogeneous at the cellular scale. We study the mechanics of type I collagen on the scale of tens to hundreds of microns by using holographic optical tweezers to apply pN forces to microparticles embedded in the collagen fiber network. We find that in response to optical forces, particle displacements are inhomogeneous, anisotropic, and asymmetric. Gels prepared at 21 °C and 37 °C show qualitative difference in their micromechanical characteristics. We also demonstrate that contracting cells remodel the micromechanics of their surrounding extracellular matrix in a strain- and distance-dependent manner. To further understand the micromechanics of cellularized extracellular matrix, we have constructed a computational model which reproduces the main experiment findings. PMID:26324923

  13. Collective specification of cellular development.

    PubMed

    Sachs, Tsvi

    2003-09-01

    Studies of chimeras and in vivo development demonstrate that cell lineages are often quite variable, apparently in response to chance perturbations. This points to an apparent contradiction: although individual cells are the units of genetic information and differentiation, not all cellular events need be precise for the development of functional organisms. The social organization of ants can serve as a metaphor that helps understand the mechanisms that underlie such development. Ants suggest that continued cellular interactions and environmental conditions could specify the proportion and general location of specialized units. Leaf venation is used as a concrete example of this general principle. A signal produced continuously by all cells specifies a requirement for vein differentiation. The cells that respond by differentiation then transport the signal away from the leaf; this removal acting as a feedback indicating that the requirement is being met. Because transport increases during vein differentiation, early initiation occurs in excess and vein 'competition' for the signal assures an acceptable outcome. Such specification would be robust since it does not depend on events in any single cell, and chance events, rather than being corrected or reversed, may be built upon in reaching an expected, collective phenotype. The absence of detailed information preceding development distinguishes this hypothesis from the common alternatives of a program or blueprint. Collective specification would have important implications for developmental plasticity and evolution. PMID:12938179

  14. Cellular uptake of metallated cobalamins.

    PubMed

    Tran, Mai Thanh Quynh; Stürup, Stefan; Lambert, Ian Henry; Gammelgaard, Bente; Furger, Evelyne; Alberto, Roger

    2016-03-16

    Cellular uptake of vitamin B12-cisplatin conjugates was estimated via detection of their metal constituents (Co, Pt, and Re) by inductively coupled plasma mass spectrometry (ICP-MS). Vitamin B12 (cyano-cob(iii)alamin) and aquo-cob(iii)alamin [Cbl-OH2](+), which differ in the β-axial ligands (CN(-) and H2O, respectively), were included as control samples. The results indicated that B12 derivatives delivered cisplatin to both cellular cytosol and nuclei with an efficiency of one third compared to the uptake of free cisplatin cis-[Pt(II)Cl2(NH3)2]. In addition, uptake of charged B12 derivatives including [Cbl-OH2](+), [{Co}-CN-{cis-PtCl(NH3)2}](+), [{Re}-{Co}-CN-{cis-PtCl(NH3)2}](+), and [{Co}-CN-{trans-Pt(Cyt)(NH3)2}](2+) (Cyt = cytarabin) was high compared to neutral B12, which implied the existence of an additional internalization pathway for charged B12 vitamin analogs. The affinities of the charged B12 derivatives to the B12 transporters HC, IF and TC were similar to that of native vitamin B12. PMID:26739575

  15. Cellular Therapy for Heart Failure.

    PubMed

    Psaltis, Peter J; Schwarz, Nisha; Toledo-Flores, Deborah; Nicholls, Stephen J

    2016-01-01

    The pathogenesis of cardiomyopathy and heart failure (HF) is underpinned by complex changes at subcellular, cellular and extracellular levels in the ventricular myocardium. For all of the gains that conventional treatments for HF have brought to mortality and morbidity, they do not adequately address the loss of cardiomyocyte numbers in the remodeling ventricle. Originally conceived to address this problem, cellular transplantation for HF has already gone through several stages of evolution over the past two decades. Various cell types and delivery routes have been implemented to positive effect in preclinical models of ischemic and nonischemic cardiomyopathy, with pleiotropic benefits observed in terms of myocardial remodeling, systolic and diastolic performance, perfusion, fibrosis, inflammation, metabolism and electrophysiology. To a large extent, these salubrious effects are now attributed to the indirect, paracrine capacity of transplanted stem cells to facilitate endogenous cardiac repair processes. Promising results have also followed in early phase human studies, although these have been relatively modest and somewhat inconsistent. This review details the preclinical and clinical evidence currently available regarding the use of pluripotent stem cells and adult-derived progenitor cells for cardiomyopathy and HF. It outlines the important lessons that have been learned to this point in time, and balances the promise of this exciting field against the key challenges and questions that still need to be addressed at all levels of research, to ensure that cell therapy realizes its full potential by adding to the armamentarium of HF management. PMID:27280304

  16. Cellular Biology of Prion Diseases

    PubMed Central

    Harris, David A.

    1999-01-01

    Prion diseases are fatal neurodegenerative disorders of humans and animals that are important because of their impact on public health and because they exemplify a novel mechanism of infectivity and biological information transfer. These diseases are caused by conformational conversion of a normal host glycoprotein (PrPC) into an infectious isoform (PrPSc) that is devoid of nucleic acid. This review focuses on the current understanding of prion diseases at the cell biological level. The characteristics of the diseases are introduced, and a brief history and description of the prion hypothesis are given. Information is then presented about the structure, expression, biosynthesis, and possible function of PrPC, as well as its posttranslational processing, cellular localization, and trafficking. The latest findings concerning PrPSc are then discussed, including cell culture systems used to generate this pathogenic isoform, the subcellular distribution of the protein, its membrane attachment, proteolytic processing, and its kinetics and sites of synthesis. Information is also provided on molecular models of the PrPC→PrPSc conversion reaction and the possible role of cellular chaperones. The review concludes with suggestions of several important avenues for future investigation. PMID:10398674

  17. Engineering cellular response using nanopatterned bulk metallic glass.

    PubMed

    Padmanabhan, Jagannath; Kinser, Emily R; Stalter, Mark A; Duncan-Lewis, Christopher; Balestrini, Jenna L; Sawyer, Andrew J; Schroers, Jan; Kyriakides, Themis R

    2014-05-27

    Nanopatterning of biomaterials is rapidly emerging as a tool to engineer cell function. Bulk metallic glasses (BMGs), a class of biocompatible materials, are uniquely suited to study nanopattern-cell interactions as they allow for versatile fabrication of nanopatterns through thermoplastic forming. Work presented here employs nanopatterned BMG substrates to explore detection of nanopattern feature sizes by various cell types, including cells that are associated with foreign body response, pathology, and tissue repair. Fibroblasts decreased in cell area as the nanopattern feature size increased, and fibroblasts could detect nanopatterns as small as 55 nm in size. Macrophages failed to detect nanopatterns of 150 nm or smaller in size, but responded to a feature size of 200 nm, resulting in larger and more elongated cell morphology. Endothelial cells responded to nanopatterns of 100 nm or larger in size by a significant decrease in cell size and elongation. On the basis of these observations, nondimensional analysis was employed to correlate cellular morphology and substrate nanotopography. Analysis of the molecular pathways that induce cytoskeletal remodeling, in conjunction with quantifying cell traction forces with nanoscale precision using a unique FIB-SEM technique, enabled the characterization of underlying biomechanical cues. Nanopatterns altered serum protein adsorption and effective substrate stiffness, leading to changes in focal adhesion density and compromised activation of Rho-A GTPase in fibroblasts. As a consequence, cells displayed restricted cell spreading and decreased collagen production. These observations suggest that topography on the nanoscale can be designed to engineer cellular responses to biomaterials. PMID:24724817

  18. Engineering Cellular Response Using Nanopatterned Bulk Metallic Glass

    PubMed Central

    2015-01-01

    Nanopatterning of biomaterials is rapidly emerging as a tool to engineer cell function. Bulk metallic glasses (BMGs), a class of biocompatible materials, are uniquely suited to study nanopattern–cell interactions as they allow for versatile fabrication of nanopatterns through thermoplastic forming. Work presented here employs nanopatterned BMG substrates to explore detection of nanopattern feature sizes by various cell types, including cells that are associated with foreign body response, pathology, and tissue repair. Fibroblasts decreased in cell area as the nanopattern feature size increased, and fibroblasts could detect nanopatterns as small as 55 nm in size. Macrophages failed to detect nanopatterns of 150 nm or smaller in size, but responded to a feature size of 200 nm, resulting in larger and more elongated cell morphology. Endothelial cells responded to nanopatterns of 100 nm or larger in size by a significant decrease in cell size and elongation. On the basis of these observations, nondimensional analysis was employed to correlate cellular morphology and substrate nanotopography. Analysis of the molecular pathways that induce cytoskeletal remodeling, in conjunction with quantifying cell traction forces with nanoscale precision using a unique FIB-SEM technique, enabled the characterization of underlying biomechanical cues. Nanopatterns altered serum protein adsorption and effective substrate stiffness, leading to changes in focal adhesion density and compromised activation of Rho-A GTPase in fibroblasts. As a consequence, cells displayed restricted cell spreading and decreased collagen production. These observations suggest that topography on the nanoscale can be designed to engineer cellular responses to biomaterials. PMID:24724817

  19. Molecular and Cellular Mechanisms of Muscle Aging and Sarcopenia and Effects of Electrical Stimulation in Seniors

    PubMed Central

    Barberi, Laura; Scicchitano, Bianca Maria

    2015-01-01

    The prolongation of skeletal muscle strength in aging and neuromuscular disease has been the objective of numerous studies employing a variety of approaches. It is generally accepted that cumulative failure to repair damage related to an overall decrease in anabolic processes is a primary cause of functional impairment in muscle. The functional performance of skeletal muscle tissues declines during post- natal life and it is compromised in different diseases, due to an alteration in muscle fiber composition and an overall decrease in muscle integrity as fibrotic invasions replace functional contractile tissue. Characteristics of skeletal muscle aging and diseases include a conspicuous reduction in myofiber plasticity (due to the progressive loss of muscle mass and in particular of the most powerful fast fibers), alteration in muscle-specific transcriptional mechanisms, and muscle atrophy. An early decrease in protein synthetic rates is followed by a later increase in protein degradation, to affect biochemical, physiological, and morphological parameters of muscle fibers during the aging process. Alterations in regenerative pathways also compromise the functionality of muscle tissues. In this review we will give an overview of the work on molecular and cellular mechanisms of aging and sarcopenia and the effects of electrical stimulation in seniors.. PMID:26913161

  20. The Cellular Automata for modelling of spreading of lava flow on the earth surface

    NASA Astrophysics Data System (ADS)

    Jarna, A.

    2012-12-01

    Volcanic risk assessment is a very important scientific, political and economic issue in densely populated areas close to active volcanoes. Development of effective tools for early prediction of a potential volcanic hazard and management of crises are paramount. However, to this date volcanic hazard maps represent the most appropriate way to illustrate the geographical area that can potentially be affected by a volcanic event. Volcanic hazard maps are usually produced by mapping out old volcanic deposits, however dynamic lava flow simulation gaining popularity and can give crucial information to corroborate other methodologies. The methodology which is used here for the generation of volcanic hazard maps is based on numerical simulation of eruptive processes by the principle of Cellular Automata (CA). The python script is integrated into ArcToolbox in ArcMap (ESRI) and the user can select several input and output parameters which influence surface morphology, size and shape of the flow, flow thickness, flow velocity and length of lava flows. Once the input parameters are selected, the software computes and generates hazard maps on the fly. The results can be exported to Google Maps (.klm format) to visualize the results of the computation. For validation of the simulation code are used data from a real lava flow. Comparison of the simulation results with real lava flows mapped out from satellite images will be presented.

  1. The cellular automata for modelling of spreading of lava flow on the earth surface

    NASA Astrophysics Data System (ADS)

    Jarna, Alexandra; Cirbus, Juraj

    2013-04-01

    Volcanic risk assessment is a very important scientific, political and economic issue in densely populated areas close to active volcanoes. Development of effective tools for early prediction of a potential volcanic hazard and management of crises are paramount. However, to this date volcanic hazard maps represent the most appropriate way to illustrate the geographical area that can potentially be affected by a volcanic event. Volcanic hazard maps are usually produced by mapping out old volcanic deposits, however dynamic lava flow simulation gaining popularity and can give crucial information to corroborate other methodologies. The methodology which is used here for the generation of volcanic hazard maps is based on numerical simulation of eruptive processes by the principle of Cellular Automata (CA). The python script is integrated into ArcToolbox in ArcMap (ESRI) and the user can select several input and output parameters which influence surface morphology, size and shape of the flow, flow thickness, flow velocity and length of lava flows. Once the input parameters are selected, the software computes and generates hazard maps on the fly. The results can be exported to Google Maps (.klm format) to visualize the results of the computation. For validation of the simulation code are used data from a real lava flow.

  2. Functional morphology of the integumentary system in fishes

    USGS Publications Warehouse

    Elliott, D.G.

    2011-01-01

    The integument that covers the outer surface of a fish’s body and fins is a multifunctional organ, with morphological features highly adapted to carry out these functions. The integument consists of two layers. The outer layer, the epidermis, is essentially cellular in structure, comprised of a multilayered epithelium that usually includes specialized cells. The inner layer, the dermis, is primarily a fibrous structure with relatively few cells, although it may contain scales, nerves, blood vessels, adipose tissue, and pigment cells.

  3. Composite alginate gels for tunable cellular microenvironment mechanics

    NASA Astrophysics Data System (ADS)

    Khavari, Adele; Nydén, Magnus; Weitz, David A.; Ehrlicher, Allen J.

    2016-08-01

    The mechanics of the cellular microenvironment can be as critical as biochemistry in directing cell behavior. Many commonly utilized materials derived from extra-cellular-matrix create excellent scaffolds for cell growth, however, evaluating the relative mechanical and biochemical effects independently in 3D environments has been difficult in frequently used biopolymer matrices. Here we present 3D sodium alginate hydrogel microenvironments over a physiological range of stiffness (E = 1.85 to 5.29 kPa), with and without RGD binding sites or collagen fibers. We use confocal microscopy to measure the growth of multi-cellular aggregates (MCAs), of increasing metastatic potential in different elastic moduli of hydrogels, with and without binding factors. We find that the hydrogel stiffness regulates the growth and morphology of these cell clusters; MCAs grow larger and faster in the more rigid environments similar to cancerous breast tissue (E = 4–12 kPa) as compared to healthy tissue (E = 0.4–2 kpa). Adding binding factors from collagen and RGD peptides increases growth rates, and change maximum MCA sizes. These findings demonstrate the utility of these independently tunable mechanical/biochemistry gels, and that mechanical confinement in stiffer microenvironments may increase cell proliferation.

  4. Composite alginate gels for tunable cellular microenvironment mechanics.

    PubMed

    Khavari, Adele; Nydén, Magnus; Weitz, David A; Ehrlicher, Allen J

    2016-01-01

    The mechanics of the cellular microenvironment can be as critical as biochemistry in directing cell behavior. Many commonly utilized materials derived from extra-cellular-matrix create excellent scaffolds for cell growth, however, evaluating the relative mechanical and biochemical effects independently in 3D environments has been difficult in frequently used biopolymer matrices. Here we present 3D sodium alginate hydrogel microenvironments over a physiological range of stiffness (E = 1.85 to 5.29 kPa), with and without RGD binding sites or collagen fibers. We use confocal microscopy to measure the growth of multi-cellular aggregates (MCAs), of increasing metastatic potential in different elastic moduli of hydrogels, with and without binding factors. We find that the hydrogel stiffness regulates the growth and morphology of these cell clusters; MCAs grow larger and faster in the more rigid environments similar to cancerous breast tissue (E = 4-12 kPa) as compared to healthy tissue (E = 0.4-2 kpa). Adding binding factors from collagen and RGD peptides increases growth rates, and change maximum MCA sizes. These findings demonstrate the utility of these independently tunable mechanical/biochemistry gels, and that mechanical confinement in stiffer microenvironments may increase cell proliferation. PMID:27484403

  5. Composite alginate gels for tunable cellular microenvironment mechanics

    PubMed Central

    Khavari, Adele; Nydén, Magnus; Weitz, David A.; Ehrlicher, Allen J.

    2016-01-01

    The mechanics of the cellular microenvironment can be as critical as biochemistry in directing cell behavior. Many commonly utilized materials derived from extra-cellular-matrix create excellent scaffolds for cell growth, however, evaluating the relative mechanical and biochemical effects independently in 3D environments has been difficult in frequently used biopolymer matrices. Here we present 3D sodium alginate hydrogel microenvironments over a physiological range of stiffness (E = 1.85 to 5.29 kPa), with and without RGD binding sites or collagen fibers. We use confocal microscopy to measure the growth of multi-cellular aggregates (MCAs), of increasing metastatic potential in different elastic moduli of hydrogels, with and without binding factors. We find that the hydrogel stiffness regulates the growth and morphology of these cell clusters; MCAs grow larger and faster in the more rigid environments similar to cancerous breast tissue (E = 4–12 kPa) as compared to healthy tissue (E = 0.4–2 kpa). Adding binding factors from collagen and RGD peptides increases growth rates, and change maximum MCA sizes. These findings demonstrate the utility of these independently tunable mechanical/biochemistry gels, and that mechanical confinement in stiffer microenvironments may increase cell proliferation. PMID:27484403

  6. Thermomechanical characterisation of cellular rubber

    NASA Astrophysics Data System (ADS)

    Seibert, H.; Scheffer, T.; Diebels, S.

    2016-01-01

    This contribution discusses an experimental possibility to characterise a cellular rubber in terms of the influence of multiaxiality, rate dependency under environmental temperature and its behaviour under hydrostatic pressure. In this context, a mixed open and closed cell rubber based on an ethylene propylene diene monomer is investigated exemplarily. The present article intends to give a general idea of the characterisation method and the considerable effects of this special type of material. The main focus lies on the experimental procedure and the used testing devices in combination with the analysis methods such as true three-dimensional digital image correlation. The structural compressibility is taken into account by an approach for a material model using the Theory of Porous Media with additional temperature dependence.

  7. [Cellular pathology of neurodegenerative disorders].

    PubMed

    Wakabayashi, Koichi

    2013-01-01

    Common cellular and molecular mechanisms including protein aggregation and inclusion body formation are involved in many neurodegenerative diseases. α-Synuclein is a major component of Lewy bodies in Parkinson's disease (PD) as well as in glial cytoplasmic inclusions in multiple system atrophy (MSA). Tau is a principal component of neurofibrillary and glial tangles in tauopathies. Recently, TDP-43 was identified as a component of ubiquitinated inclusions in amyotrophic lateral sclerosis and frontotemporal lobar degeneration. PD is traditionally considered a movement disorder with hallmark lesions in the brainstem pigmented nuclei. However, pathological changes occur in widespread regions of the central and peripheral nervous systems in this disease. Furthermore, primary glial involvement ("gliodegeneration") can be observed in PD and MSA as well as in tauopathy. The present article reviews abnormal protein accumulation and inclusion body formation inside and outside the central nervous system. PMID:23965852

  8. Regulation of cellular chromatin state

    PubMed Central

    Mishra, Rakesh K; Dhawan, Jyotsna

    2010-01-01

    The identity and functionality of eukaryotic cells is defined not just by their genomic sequence which remains constant between cell types, but by their gene expression profiles governed by epigenetic mechanisms. Epigenetic controls maintain and change the chromatin state throughout development, as exemplified by the setting up of cellular memory for the regulation and maintenance of homeotic genes in proliferating progenitors during embryonic development. Higher order chromatin structure in reversibly arrested adult stem cells also involves epigenetic regulation and in this review we highlight common trends governing chromatin states, focusing on quiescence and differentiation during myogenesis. Together, these diverse developmental modules reveal the dynamic nature of chromatin regulation providing fresh insights into the role of epigenetic mechanisms in potentiating development and differentiation. PMID:20592864

  9. Pressure-actuated cellular structures.

    PubMed

    Pagitz, M; Lamacchia, E; Hol, J M A M

    2012-03-01

    Shape changing structures will play an important role in future engineering designs since rigid structures are usually only optimal for a small range of service conditions. Hence, a concept for reliable and energy-efficient morphing structures that possess a large strength to self-weight ratio would be widely applicable. We propose a novel concept for morphing structures that is inspired by the nastic movement of plants. The idea is to connect prismatic cells with tailored pentagonal and/or hexagonal cross sections such that the resulting cellular structure morphs into given target shapes for certain cell pressures. An efficient algorithm for computing equilibrium shapes as well as cross-sectional geometries is presented. The potential of this novel concept is demonstrated by several examples that range from a flagellum like propulsion device to a morphing aircraft wing. PMID:22278936

  10. Force generation by cellular motors.

    PubMed

    Wanka, Friedrich; Van Zoelen, Everardus J J

    2003-01-01

    Cell motility processes in non-muscle cells depend on the activity of motor proteins that bind to either microtubules or actin filaments. From presently available data it must be concluded that the driving force is generated by transient interaction of the respective motors with microtubules or actin filaments which then activates the binding and hydrolysis of ATP. This reaction results in an abrupt discharge of the motor molecule, the direction of which is determined by the spatial orientation of its binding to the helical and polar vehicle. The latter is thereby propelled in its length direction and simultaneously undergoes an axial rotation, while the expelled motor exerts an oppositely directed current in the surrounding fluid, comparable to jet propulsion. Force production, propulsion velocities and energy requirements known from in vitro studies comply with those derived from the theory. The theory opens new ways for the understanding of cellular activities such as particle transport, mitosis and morphodynamics. PMID:14668925

  11. Cellular compartmentalization of secondary metabolism

    PubMed Central

    Kistler, H. Corby; Broz, Karen

    2015-01-01

    Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors shared with the most essential processes of the cell (e.g., amino acids, acetyl CoA, NADPH), enzymes for secondary metabolite synthesis are compartmentalized at conserved subcellular sites that position pathway enzymes to use these common biochemical precursors. Co-compartmentalization of secondary metabolism pathway enzymes also may function to channel precursors, promote pathway efficiency and sequester pathway intermediates and products from the rest of the cell. In this review we discuss the compartmentalization of three well-studied fungal secondary metabolite biosynthetic pathways for penicillin G, aflatoxin and deoxynivalenol, and summarize evidence used to infer subcellular localization. We also discuss how these metabolites potentially are trafficked within the cell and may be exported. PMID:25709603

  12. Cellular tolerance to pulsed heating

    NASA Astrophysics Data System (ADS)

    Simanovski, Dimitrii; Sarkar, M.; Irani, A.; O'Connell-Rodwell, C.; Contag, C.; Schwettman, H. Alan; Palanker, D.

    2005-04-01

    Many laser therapies involve significant heating of tissue with pulses varying from picoseconds to minutes in duration. In some of the applications heating is a primary goal, while in others it is an undesirable side effect. In both cases, if a hyperthermia is involved, the knowledge about the threshold temperature leading to irreversible cellular damage is critically important. We study the dependence of the threshold temperature on duration of the heat exposure in the range of 0.3 ms to 5 seconds. Thin layer of cells cultured in a Petri dish was exposed to a pulsed CO2 laser radiation. Laser beam was focused onto sample providing Gaussian intensity distribution in the focal plane with a beam diameter (2w) 2-10 mm. Surface temperature in the central part of the focal spot (1mm in diameter) was measured by thermal infrared (IR) emission from the sample, recorded with a fast IR detector. For pulses shorter than 1 s the temperature profile across the focal spot was found to closely correspond to the radial distribution of the laser beam intensity, thus allowing for accurate determination of temperature at any given distance from the center of the spot. Immediate cellular damage was assessed using vital staining with the live/dead fluorescent assay. Threshold temperatures were found to vary from 65 °C at 5 s of heating to 160 °C at pulses of 0.3 ms in duration. The shorter end of this range was limited by vaporization, which occurs during the laser pulse and results in mechanical damage to cells. Dependence of the maximal temperature on pulse duration could be approximated by Arrhenius law with activation energy being about 1 eV.

  13. Fundamental Limits to Cellular Sensing

    NASA Astrophysics Data System (ADS)

    ten Wolde, Pieter Rein; Becker, Nils B.; Ouldridge, Thomas E.; Mugler, Andrew

    2016-03-01

    In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at low concentrations. The signaling networks that transmit the information on the ligand concentration from the receptors into the cell have to filter this receptor input noise as much as possible. These networks, however, are also intrinsically stochastic in nature, which means that they will also add noise to the transmitted signal. In this review, we will first discuss how the diffusive transport and binding of ligand to the receptor sets the receptor correlation time, which is the timescale over which fluctuations in the state of the receptor, arising from the stochastic receptor-ligand binding, decay. We then describe how downstream signaling pathways integrate these receptor-state fluctuations, and how the number of receptors, the receptor correlation time, and the effective integration time set by the downstream network, together impose a fundamental limit on the precision of sensing. We then discuss how cells can remove the receptor input noise while simultaneously suppressing the intrinsic noise in the signaling network. We describe why this mechanism of time integration requires three classes (groups) of resources—receptors and their integration time, readout molecules, energy—and how each resource class sets a fundamental sensing limit. We also briefly discuss the scheme of maximum-likelihood estimation, the role of receptor cooperativity, and how cellular copy protocols differ from canonical copy protocols typically considered in the computational literature, explaining why cellular sensing systems can never reach the Landauer limit on the optimal trade

  14. Vesta's shape and morphology.

    PubMed

    Jaumann, R; Williams, D A; Buczkowski, D L; Yingst, R A; Preusker, F; Hiesinger, H; Schmedemann, N; Kneissl, T; Vincent, J B; Blewett, D T; Buratti, B J; Carsenty, U; Denevi, B W; De Sanctis, M C; Garry, W B; Keller, H U; Kersten, E; Krohn, K; Li, J-Y; Marchi, S; Matz, K D; McCord, T B; McSween, H Y; Mest, S C; Mittlefehldt, D W; Mottola, S; Nathues, A; Neukum, G; O'Brien, D P; Pieters, C M; Prettyman, T H; Raymond, C A; Roatsch, T; Russell, C T; Schenk, P; Schmidt, B E; Scholten, F; Stephan, K; Sykes, M V; Tricarico, P; Wagner, R; Zuber, M T; Sierks, H

    2012-05-11

    Vesta's surface is characterized by abundant impact craters, some with preserved ejecta blankets, large troughs extending around the equatorial region, enigmatic dark material, and widespread mass wasting, but as yet an absence of volcanic features. Abundant steep slopes indicate that impact-generated surface regolith is underlain by bedrock. Dawn observations confirm the large impact basin (Rheasilvia) at Vesta's south pole and reveal evidence for an earlier, underlying large basin (Veneneia). Vesta's geology displays morphological features characteristic of the Moon and terrestrial planets as well as those of other asteroids, underscoring Vesta's unique role as a transitional solar system body. PMID:22582254

  15. Experimental impact crater morphology

    NASA Astrophysics Data System (ADS)

    Dufresne, A.; Poelchau, M. H.; Hoerth, T.; Schaefer, F.; Thoma, K.; Deutsch, A.; Kenkmann, T.

    2012-04-01

    The research group MEMIN (Multidisciplinary Experimental and Impact Modelling Research Network) is conducting impact experiments into porous sandstones, examining, among other parameters, the influence of target pore-space saturation with water, and projectile velocity, density and mass, on the cratering process. The high-velocity (2.5-7.8 km/s) impact experiments were carried out at the two-stage light-gas gun facilities of the Fraunhofer Institute EMI (Germany) using steel, iron meteorite (Campo del Cielo IAB), and aluminium projectiles with Seeberg Sandstone as targets. The primary objectives of this study within MEMIN are to provide detailed morphometric data of the experimental craters, and to identify trends and characteristics specific to a given impact parameter. Generally, all craters, regardless of impact conditions, have an inner depression within a highly fragile, white-coloured centre, an outer spallation (i.e. tensile failure) zone, and areas of arrested spallation (i.e. spall fragments that were not completely dislodged from the target) at the crater rim. Within this general morphological framework, distinct trends and differences in crater dimensions and morphological characteristics are identified. With increasing impact velocity, the volume of craters in dry targets increases by a factor of ~4 when doubling velocity. At identical impact conditions (steel projectiles, ~5km/s), craters in dry and wet sandstone targets differ significantly in that "wet" craters are up to 76% larger in volume, have depth-diameter ratios generally below 0.19 (whereas dry craters are almost consistently above this value) at significantly larger diameters, and their spallation zone morphologies show very different characteristics. In dry craters, the spall zone surfaces dip evenly at 10-20° towards the crater centre. In wet craters, on the other hand, they consist of slightly convex slopes of 10-35° adjacent to the inner depression, and of sub-horizontal tensile

  16. Cluster Morphology Analysis

    PubMed Central

    Jacquez, Geoffrey M.

    2009-01-01

    Most disease clustering methods assume specific shapes and do not evaluate statistical power using the applicable geography, at-risk population, and covariates. Cluster Morphology Analysis (CMA) conducts power analyses of alternative techniques assuming clusters of different relative risks and shapes. Results are ranked by statistical power and false positives, under the rationale that surveillance should (1) find true clusters while (2) avoiding false clusters. CMA then synthesizes results of the most powerful methods. CMA was evaluated in simulation studies and applied to pancreatic cancer mortality in Michigan, and finds clusters of flexible shape while routinely evaluating statistical power. PMID:20234799

  17. Controlling Cellular Endocytosis at the Nanoscale

    NASA Astrophysics Data System (ADS)

    Battaglia, Giuseppe

    2011-03-01

    , amphiphilic molecules, and hydrophilic molecules without affecting the viability of cells or even triggering inflammatory pathways. Finally we show how size, surface chemistry and surface topology of the vesicles affect their interaction with the cell membrane and hence their cellular uptake. References: C. Lo Presti, M. Massignani, T. Smart, H. Lomas, and G. Battaglia J. Mater. Chem. (2009) 19, 3576-3590 H. Lomas, I. Canton, S. MacNeil, J. Du, S.P. Armes, A.J. Ryan, A.L. Lewis and G. Battaglia Adv. Mater. (2007). 19, 4238-4243 M. Massignani, I. Canton, N. Patikarnmonthon, N. J. Warren, S. P. Armes, A. L. Lewis and G. Battaglia, Nature Prec., 2010, http://hdl.handle.net/10101/npre.2010.4427.1 M. Massignani, C. LoPresti, A. Blanazs, J. Madsen, S. P. Armes, A. L. Lewis and G. Battaglia Small, 2009, 5, 2424-2432. M. Massignani, T. Sun, A. Blanazs, V. Hearnden, I. Canton, P. Desphande, S. Armes, S. MacNeil, A. Lewis and G. Battaglia PLoS One, 2010, 5, e10459.

  18. Vitamin E Supplementation Delays Cellular Senescence In Vitro

    PubMed Central

    La Fata, Giorgio; Seifert, Nicole; Weber, Peter; Mohajeri, M. Hasan

    2015-01-01

    Vitamin E is an important antioxidant that protects cells from oxidative stress-induced damage, which is an important contributor to the progression of ageing. Ageing can be studied in vitro using primary cells reaching a state of irreversible growth arrest called senescence after a limited number of cellular divisions. Generally, the most utilized biomarker of senescence is represented by the expression of the senescence associated β-galactosidase (SA-β-gal). We aimed here to study the possible effects of vitamin E supplementation in two different human primary cell types (HUVECs and fibroblasts) during the progression of cellular senescence. Utilizing an unbiased automated system, based on the detection of the SA-β-gal, we quantified cellular senescence in vitro and showed that vitamin E supplementation reduced the numbers of senescent cells during progression of ageing. Acute vitamin E supplementation did not affect cellular proliferation, whereas it was decreased after chronic treatment. Mechanistically, we show that vitamin E supplementation acts through downregulation of the expression of the cycline dependent kinase inhibitor P21. The data obtained from this study support the antiageing properties of vitamin E and identify possible mechanisms of action that warrant further investigation. PMID:26613084

  19. A synthetic biology approach to understanding cellular information processing

    PubMed Central

    Riccione, Katherine A; Smith, Robert P; Lee, Anna J; You, Lingchong

    2012-01-01

    The survival of cells and organisms requires proper responses to environmental signals. These responses are governed by cellular networks, which serve to process diverse environmental cues. Biological networks often contain recurring network topologies called ‘motifs’. It has been recognized that the study of such motifs allows one to predict the response of a biological network, and thus cellular behavior. However, studying a single motif in complete isolation of all other network motifs in a natural setting is difficult. Synthetic biology has emerged as a powerful approach to understanding the dynamic properties of network motifs. In addition to testing existing theoretical predictions, construction and analysis of synthetic gene circuits has led to the discovery of novel motif dynamics such as how the combination of simple motifs can lead to autonomous dynamics or how noise in transcription and translation can affect the dynamics of a motif. Here, we review developments in synthetic biology as they pertain to increasing our understanding of cellular information processing. We highlight several types of dynamic behaviors that diverse motifs can generate, including the control of input/output responses, the generation of autonomous spatial and temporal dynamics, as well as the influence of noise in motif dynamics and cellular behavior. PMID:23411668

  20. Vitamin E Supplementation Delays Cellular Senescence In Vitro.

    PubMed

    La Fata, Giorgio; Seifert, Nicole; Weber, Peter; Mohajeri, M Hasan

    2015-01-01

    Vitamin E is an important antioxidant that protects cells from oxidative stress-induced damage, which is an important contributor to the progression of ageing. Ageing can be studied in vitro using primary cells reaching a state of irreversible growth arrest called senescence after a limited number of cellular divisions. Generally, the most utilized biomarker of senescence is represented by the expression of the senescence associated β-galactosidase (SA-β-gal). We aimed here to study the possible effects of vitamin E supplementation in two different human primary cell types (HUVECs and fibroblasts) during the progression of cellular senescence. Utilizing an unbiased automated system, based on the detection of the SA-β-gal, we quantified cellular senescence in vitro and showed that vitamin E supplementation reduced the numbers of senescent cells during progression of ageing. Acute vitamin E supplementation did not affect cellular proliferation, whereas it was decreased after chronic treatment. Mechanistically, we show that vitamin E supplementation acts through downregulation of the expression of the cycline dependent kinase inhibitor P21. The data obtained from this study support the antiageing properties of vitamin E and identify possible mechanisms of action that warrant further investigation. PMID:26613084

  1. [Cellular metabolism of sodium and hypertension].

    PubMed

    Cusi, D; Colombo, R; Pozzoli, E; Bianchi, G

    1989-01-01

    Essential hypertension develops from interactions between genetic and environmental components. Studies on cell membrane ions (in particular the sodium ion) transport in essential hypertension were originally carried out in order to better understand the roles these two components play in a less complex system than the overall organ system or the single organs involved in blood pressure regulation. The theory supporting this experimental approach is based on the observation that cell membrane function affects all the phenomena involved in blood pressure regulation. Receptor function, hormonal secretion, cell volume regulation, ion transport and ion composition of the cell are all regulated at the cell membrane level. However the problem of the relevance of cellular sodium metabolism in the pathogenesis of essential hypertension and of the interpretation of the many conflicting results has grown in complexity with the growing mass of data published in the literature. At least part of this complexity seems related to methodological problems but part is surely due to real differences among the various populations or subpopulations studied. This review analyzes the main sources of the discrepancies, the different ion transport systems and the end point of the overall transport system as well as the steady state intracellular cation concentration in both genetic animal models of essential hypertension and in man. PMID:2702018

  2. Aspirin may influence cellular energy status.

    PubMed

    Kamble, Pratibha; Litvinov, Dmitry; Aluganti Narasimhulu, Chandrakala; Jiang, Xueting; Parthasarathy, Sampath

    2015-02-15

    In our previous findings, we have demonstrated that aspirin/acetyl salicylic acid (ASA) might induce sirtuins via aryl hydrocarbon receptor (Ah receptor). Induction effects included an increase in cellular paraoxonase 1 (PON1) activity and apolipoprotein A1 (ApoA1) gene expression. As predicted, ASA and salicylic acid (SA) treatment resulted in generation of H2O2, which is known to be an inducer of mitochondrial gene Sirt4 and other downstream target genes of Sirt1. Our current mass spectroscopic studies further confirm the metabolism of the drugs ASA and SA. Our studies show that HepG2 cells readily converted ASA to SA, which was then metabolized to 2,3-DHBA. HepG2 cells transfected with aryl hydrocarbon receptor siRNA upon treatment with SA showed the absence of a DHBA peak as measured by LC-MS/MS. MS studies for Sirt1 action also showed a peak at 180.9 m/z for the deacetylated and chlorinated product formed from N-acetyl lε-lysine. Thus an increase in Sirt4, Nrf2, Tfam, UCP1, eNOS, HO1 and STAT3 genes could profoundly affect mitochondrial function, cholesterol homeostasis, and fatty acid oxidation, suggesting that ASA could be beneficial beyond simply its ability to inhibit cyclooxygenase. PMID:25557764

  3. Cellular and molecular mechanisms in liver fibrogenesis.

    PubMed

    Novo, Erica; Cannito, Stefania; Paternostro, Claudia; Bocca, Claudia; Miglietta, Antonella; Parola, Maurizio

    2014-04-15

    Liver fibrogenesis is a dynamic and highly integrated molecular, tissue and cellular process, potentially reversible, that drives the progression of chronic liver diseases (CLD) towards liver cirrhosis and hepatic failure. Hepatic myofibroblasts (MFs), the pro-fibrogenic effector cells, originate mainly from activation of hepatic stellate cells and portal fibroblasts being characterized by a proliferative and survival attitude. MFs also contract in response to vasoactive agents, sustain angiogenesis and recruit and modulate activity of cells of innate or adaptive immunity. Chronic activation of wound healing and oxidative stress as well as derangement of epithelial-mesenchymal interactions are "major" pro-fibrogenic mechanisms, whatever the etiology. However, literature has outlined a complex network of pro-fibrogenic factors and mediators proposed to modulate CLD progression, with some of them being at present highly debated in the field, including the role of epithelial to mesenchymal transition and Hedgehog signaling pathways. Hypoxia and angiogenesis as well as inflammasomes are recently emerged as ubiquitous pro-inflammatory and pro-fibrogenic determinants whereas adipokines are mostly involved in CLD related to metabolic disturbances (metabolic syndrome and/or obesity and type 2 diabetes). Finally, autophagy as well as natural killer and natural killer-T cells have been recently proposed to significantly affect fibrogenic CLD progression. PMID:24631571

  4. Aspirin may influence cellular energy status

    PubMed Central

    Kamble, Pratibha; Litvinov, Dmitry; Narasimhulu, Chandrakala Aluganti; Jiang, Xueting; Parthasarathy, Sampath

    2015-01-01

    In our previous findings, we have demonstrated that aspirin/acetyl salicylic acid (ASA) might induce sirtuins via aryl hydrocarbon receptor (Ah receptor). Induction effects included an increase in cellular paraoxonase 1 (PON1) activity and apolipoprotein A1 (ApoA1) gene expression. As predicted, ASA and salicylic acid (SA) treatment resulted in generation of H2O2, which is known to be an inducer of mitochondrial gene Sirt4 and other downstream target genes of Sirt1. Our current mass spectroscopic studies further confirm the metabolism of the drugs ASA and SA. Our studies show that HepG2 cells readily converted ASA to SA, which was then metabolized to 2,3-DHBA. HepG2 cells transfected with aryl hydrocarbon receptor siRNA upon treatment with SA showed the absence of a DHBA peak as measured by LC-MS/MS. MS studies for Sirt1 action also showed a peak at 180.9 m/z for the deacetylated and chlorinated product formed from N-acetyl Lε-lysine. Thus an increase in Sirt4, Nrf2, Tfam, UCP1, eNOS, HO1 and STAT3 genes could profoundly affect mitochondrial function, cholesterol homeostasis, and fatty acid oxidation, suggesting that ASA could be beneficial beyond simply its ability to inhibit cyclooxygenase. PMID:25557764

  5. Precambrian sponges with cellular structures

    PubMed

    Li; Chen; Hua

    1998-02-01

    Sponge remains have been identified in the Early Vendian Doushantuo phosphate deposit in central Guizhou (South China), which has an age of approximately 580 million years ago. Their skeletons consist of siliceous, monaxonal spicules. All are referred to as the Porifera, class Demospongiae. Preserved soft tissues include the epidermis, porocytes, amoebocytes, sclerocytes, and spongocoel. Among thousands of metazoan embryos is a parenchymella-type of sponge larvae having a shoe-shaped morphology and dense peripheral flagella. The presence of possible amphiblastula larva suggests that the calcareous sponges may have an extended history in the Late Precambrian. The fauna indicates that animals lived 40 to 50 million years before the Cambrian Explosion. PMID:9452391

  6. Anodic Aluminum Oxide (AAO) Membranes for Cellular Devices

    NASA Astrophysics Data System (ADS)

    Ventura, Anthony P.

    Anodic Aluminum Oxide (AAO) membranes can be fabricated with a highly tunable pore structure making them a suitable candidate for cellular hybrid devices with single-molecule selectivity. The objective of this study was to characterize the cellular response of AAO membranes with varying pore sizes to serve as a proof-of-concept for an artificial material/cell synapse system. AAO membranes with pore diameters ranging from 34-117 nm were achieved via anodization at a temperature of -1°C in a 2.7% oxalic acid electrolyte. An operating window was established for this setup to create membranes with through-pore and disordered pore morphologies. C17.2 neural stem cells were seeded onto the membranes and differentiated via serum withdrawal. The data suggests a highly tunable correlation between AAO pore diameter and differentiated cell populations. Analysis of membranes before and after cell culture indicated no breakdown of the through-pore structure. Immunocytochemistry (ICC) showed that AAO membranes had increased neurite outgrowth when compared to tissue culture treated (TCT) glass, and neurite outgrowth varied with pore diameter. Additionally, lower neuronal percentages were found on AAO as compared to TCT glass; however, neuronal population was also found to vary with pore diameter. Scanning electron microscopy (SEM) and ICC images suggested the presence of a tissue-like layer with a mixed-phenotype population. AAO membranes appear to be an excellent candidate for cellular devices, but more work must be completed to understand the surface chemistry of the AAO membranes as it relates to cellular response.

  7. Cellular interactions with tissue-engineered microenvironments and nanoparticles

    NASA Astrophysics Data System (ADS)

    Pan, Zhi

    Tissue-engineered hydrogels composed of intermolecularlly crosslinked hyaluronan (HA-DTPH) and fibronectin functional domains (FNfds) were applied as a physiological relevant ECM mimic with controlled mechanical and biochemical properties. Cellular interactions with this tissue-engineered environment, especially physical interactions (cellular traction forces), were quantitatively measured by using the digital image speckle correlation (DISC) technique and finite element method (FEM). By correlating with other cell functions such as cell morphology and migration, a comprehensive structure-function relationship between cells and their environments was identified. Furthermore, spatiotemporal redistribution of cellular traction stresses was time-lapse measured during cell migration to better understand the dynamics of cell mobility. The results suggest that the reinforcement of the traction stresses around the nucleus, as well as the relaxation of nuclear deformation, are critical steps during cell migration, serving as a speed regulator, which must be considered in any dynamic molecular reconstruction model of tissue cell migration. Besides single cell migration, en masse cell migration was studied by using agarose droplet migration assay. Cell density was demonstrated to be another important parameter to influence cell behaviors besides substrate properties. Findings from these studies will provide fundamental design criteria to develop novel and effective tissue-engineered constructs. Cellular interactions with rutile and anatase TiO2 nanoparticles were also studied. These particles can penetrate easily through the cell membrane and impair cell function, with the latter being more damaging. The exposure to nanoparticles was found to decrease cell area, cell proliferation, motility, and contractility. To prevent this, a dense grafted polymer brush coating was applied onto the nanoparticle surface. These modified nanoparticles failed to adhere to and penetrate

  8. Morphology of urethral tissues

    NASA Astrophysics Data System (ADS)

    Müller, Bert; Schulz, Georg; Herzen, Julia; Mushkolaj, Shpend; Bormann, Therese; Beckmann, Felix; Püschel, Klaus

    2010-09-01

    Micro computed tomography has been developed to a powerful technique for the characterization of hard and soft human and animal tissues. Soft tissues including the urethra, however, are difficult to be analyzed, since the microstructures of interest exhibit X-ray absorption values very similar to the surroundings. Selective staining using highly absorbing species is a widely used approach, but associated with significant tissue modification. Alternatively, one can suitably embed the soft tissue, which requires the exchange of water. Therefore, the more recently developed phase contrast modes providing much better contrast of low X-ray absorbing species are especially accommodating in soft tissue characterization. The present communication deals with the morphological characterization of sheep, pig and human urethras on the micrometer scale taking advantage of micro computed tomography in absorption and phase contrast modes. The performance of grating-based tomography is demonstrated for freshly explanted male and female urethras in saline solution. The micro-morphology of the urethra is important to understand how the muscles close the urethra to reach continence. As the number of incontinent patients is steadily increasing, the function under static and, more important, under stress conditions has to be uncovered for the realization of artificial urinary sphincters, which needs sophisticated, biologically inspired concepts to become nature analogue.

  9. Scanning Ion Conductance Microscopic Study for Cellular Uptake of Cationic Conjugated Polymer Nanoparticles.

    PubMed

    Shan, Yuping; Panday, Namuna; Myoung, Yong; Twomey, Megan; Wang, Xuewen; Li, Wenzhi; Celik, Emrah; Moy, Vincent; Wang, Hongda; Moon, Joong Ho; He, Jin

    2016-04-01

    Positively charged conjugated polymer nanoparticles (CPNs) are emerging biomaterials exhibiting high levels of cellular entry. High rate of cellular entry efficiency is believed that the amphiphilic CPNs interact efficiently with the negatively charged hydrophobic cellular membranes. For the first time, the cell surface morphological changes of human cervical cancer cells treated with CPNs using a scanning probe microscopy technique, scanning ion conductance microscopy (SICM) are imaged. After 1 h of CPN incubation, distinct changes are observed in cell surface morphology such as interconnected protrusions and pits with sub-micrometer sizes, which are not observed from cells treated with positively charged polyethyleneimine (PEI) under the same treatment conditions. The change on cell surface morphology is quantified by surface roughness ratio, which is increased as CPN concentration increases, while the ratio first increases and then decreases as the incubation time increases. These results suggest that cells respond actively toward CPN with both positive charges on the side chain and the hydrophobicity from rigid aromatic backbone, which leads to subsequent endocytosis. In conclusion, it is demonstrated that SICM is a suitable imaging technique to reveal the dynamic alternations on the cell surface morphology at the early stage of nanoparticles endocytosis with high resolution. PMID:26757346

  10. HIV Infection: The Cellular Picture.

    ERIC Educational Resources Information Center

    Weber, Jonathan N.; Weiss, Robin A.

    1988-01-01

    Explains a key finding of the research which revealed that initial infection resulted from the binding of the human immunodeficiency virus to a molecule known as the CD4 antigen. Describes various assays used to determine the affect of antibodies on the ability of the virus to infect the cells. (RT)

  11. Mobile phone base station radiation does not affect neoplastic transformation in BALB/3T3 cells.

    PubMed

    Hirose, H; Suhara, T; Kaji, N; Sakuma, N; Sekijima, M; Nojima, T; Miyakoshi, J

    2008-01-01

    A large-scale in vitro study focusing on low-level radiofrequency (RF) fields from mobile radio base stations employing the International Mobile Telecommunication 2000 (IMT-2000) cellular system was conducted to test the hypothesis that modulated RF fields affect malignant transformation or other cellular stress responses. Our group previously reported that DNA strand breaks were not induced in human cells exposed to 2.1425 GHz Wideband Code Division Multiple Access (W-CDMA) radiation up to 800 mW/kg from mobile radio base stations employing the IMT-2000 cellular system. In the current study, BALB/3T3 cells were continuously exposed to 2.1425 GHz W-CDMA RF fields at specific absorption rates (SARs) of 80 and 800 mW/kg for 6 weeks and malignant cell transformation was assessed. In addition, 3-methylcholanthrene (MCA)-treated cells were exposed to RF fields in a similar fashion, to assess for effects on tumor promotion. Finally, the effect of RF fields on tumor co-promotion was assessed in BALB/3T3 cells initiated with MCA and co-exposed to 12-O-tetradecanoylphorbol-13-acetate (TPA). At the end of the incubation period, transformation dishes were fixed, stained with Giemsa, and scored for morphologically transformed foci. No significant differences in transformation frequency were observed between the test groups exposed to RF signals and the sham-exposed negative controls in the non-, MCA-, or MCA plus TPA-treated cells. Our studies found no evidence to support the hypothesis that RF fields may affect malignant transformation. Our results suggest that exposure to low-level RF radiation of up to 800 mW/kg does not indu