Millipore Sigma Vibrant Logo
 

sheets


2083 Results Búsqueda avanzada  
Mostrar
Productos (101)
Documentos (1,881)
Páginas (101)

Acote sus resultados Utilice los filtros siguientes para refinar su búsqueda

Tipo de documento

  • (1,163)
  • (360)
  • (328)
  • (15)
  • (14)
  • Mostrar más
¿No encuentra lo que está buscando?
Póngase en contacto con
el Servicio de Atención
al Cliente

 
¿Necesita ayuda para encontrar un documento?

  • The fate of outer hair cells after acoustic or ototoxic insults. 16777363

    In epithelial sheets, clearance of dead cells may occur by one of several routes, including extrusion into the lumen, phagocytic clearance by invading lymphocytes, or phagocytosis by neighboring cells. The fate of dead cochlear outer hair cells is unclear. We investigated the fate of the corpses of dead outer hair cells in guinea pigs and mice following drug or noise exposure. We examined whole mounts and plastic sections of normal and lesioned organ of Corti for the presence of prestin, a protein unique to outer hair cells. Supporting cells, which are devoid of prestin in the normal ear, contained clumps of prestin in areas of hair cell loss. The data show that cochlear supporting cells surround the corpses and/or debris of degenerated outer hair cells, and suggest that outer hair cell remains are phagocytosed by supporting cells within the epithelium.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB3580
    Nombre del producto:
    Anti-Green Fluorescent Protein Antibody

  • Roles of focal adhesions and fibronectin-mediated cohesion in proliferation of confluent fibroblasts. 19107843

    Multilayered fibroblast sheets have applications as cell transplants for tissue engineering. One way to increase their therapeutic efficacy is to increase cell numbers in a graft, but the factors influencing multilayered growth remain poorly understood. In this study, we investigated the roles of focal adhesion (FA) assembly and intercellular cohesion through fibronectin (FN) in the proliferation of normal human fibroblasts at confluence. Density-dependent growth-arrested fibroblasts resumed DNA synthesis when cultured in multilayer formation medium (MFM) containing transforming growth factor-beta1, ascorbic acid, and serum. This proliferation depended on alpha 5 beta 1-integrin-mediated cell-FN-cell interactions because blocking them with antibodies inhibited DNA synthesis. However, cell-FN-cell cohesion operated well regardless of exposure to MFM, judging from several parameters, including FN matrix deposition, activated beta1 integrin expression, and stress fiber development. Density-arrested cells formed few FAs at the cell center. Exposure of the cells to MFM induced the formation of vinculin-, paxillin-, and phosphotyrosine-containing FAs throughout the ventral cell-surface, indicating ROCK-mediated actomyosin contractile force generation. When the assembly of FAs was inhibited with either the ROCK inhibitor Y-27632 or the myosin II inhibitor blebbistatin, the up-regulation of DNA synthesis by MFM was suppressed. The drugs did not impair FN matrix deposition, activated beta1 integrin expression, and stress fiber development. Thus, these results indicate that the formation of FAs promotes the proliferation of confluent fibroblasts with the support of alpha 5 beta 1-integrin-mediated cell-FN-cell cohesion. The present findings provide insights into the rational design of high-density fibroblast transplants.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB349
    Nombre del producto:
    Anti-Amyloid Precursor Protein Antibody, A4(695), clone 1.D5

  • Transplanted sheets of human retina and retinal pigment epithelium develop normally in nude rats. 12137757

    This study investigated whether transplanted sheets of human fetal retina together with its retinal pigment epithelium (RPE) could develop and maintain their cytoarchitecture after long survival times. Transplant recipients were nine albino athymic nu/nu rats with a normal retina. The donor tissue was dissected from fetuses of 12-17 weeks gestational age. Transplants were analyzed at 5-12 months after surgery by light and electron microscopy, and immunohistochemistry with various antibodies specific for rhodopsin, S-antigen, transducin, neurofilament and synaptophysin. In 4 of 11 transplants, the RPE stayed as a monolayer sheet and supported the development of the retinal sheet with a normal lamination, including photoreceptor inner and outer segments. Cones and rods in the organized transplants were labeled with different photoreceptor markers. Inner and outer plexiform layers, containing cone pedicles and rods spherules, were immunoreactive for synaptophysin. As the recipients had a normal retina, transplant/host integration was not expected. However, at the transplant/host interface, there were sometimes areas without glial barriers, and neurofilament-containing processes could be observed crossing between transplant and host. In other, more disorganized transplants, the RPE cells were partially dispersed or clumped together in clusters. Such transplants developed photoreceptors in rosettes, often with inner and outer segments.In conclusion, sheets of human fetal retina transplanted together with its RPE to the subretinal space of nude rats can develop and maintain perfectly laminated transplants after long survival times, indicating the potential of applying cotransplantation to human patients with retinal diseases.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • Early fish myoseptal cells: insights from the trout and relationships with amniote axial tenocytes. 24622730

    The trunk muscle in fish is organized as longitudinal series of myomeres which are separated by sheets of connective tissue called myoseptum to which myofibers attach. In this study we show in the trout that the myoseptum separating two somites is initially acellular and composed of matricial components such as fibronectin, laminin and collagen I. However, myoseptal cells forming a continuum with skeletogenic cells surrounding axial structures are observed between adjacent myotomes after the completion of somitogenesis. The myoseptal cells do not express myogenic markers such as Pax3, Pax7 and myogenin but express several tendon-associated collagens including col1a1, col5a2 and col12a1 and angiopoietin-like 7, which is a secreted molecule involved in matrix remodelling. Using col1a1 as a marker gene, we observed in developing trout embryo an initial labelling in disseminating cells ventral to the myotome. Later, labelled cells were found more dorsally encircling the notochord or invading the intermyotomal space. This opens the possibility that the sclerotome gives rise not only to skeletogenic mesenchymal cells, as previously reported, but also to myoseptal cells. We furthermore show that myoseptal cells differ from skeletogenic cells found around the notochord by the specific expression of Scleraxis, a distinctive marker of tendon cells in amniotes. In conclusion, the location, the molecular signature and the possible sclerotomal origin of the myoseptal cells suggest that the fish myoseptal cells are homologous to the axial tenocytes in amniotes.
    Tipo de documento:
    Referencia
    Referencia del producto:
    06-570
    Nombre del producto:
    Anti-phospho-Histone H3 (Ser10) Antibody, Mitosis Marker

  • Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. 388439

    A method has been devised for the electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets. The method results in quantitative transfer of ribosomal proteins from gels containing urea. For sodium dodecyl sulfate gels, the original band pattern was obtained with no loss of resolution, but the transfer was not quantitative. The method allows detection of proteins by autoradiography and is simpler than conventional procedures. The immobilized proteins were detectable by immunological procedures. All additional binding capacity on the nitrocellulose was blocked with excess protein; then a specific antibody was bound and, finally, a second antibody directed against the first antibody. The second antibody was either radioactively labeled or conjugated to fluorescein or to peroxidase. The specific protein was then detected by either autoradiography, under UV light, or by the peroxidase reaction product, respectively. In the latter case, as little as 100 pg of protein was clearly detectable. It is anticipated that the procedure will be applicable to analysis of a wide variety of proteins with specific reactions or ligands.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • DNA single- and double-strand breaks by alkaline- and immuno-comet assay in lymphocytes of workers exposed to styrene. 19095051

    Occupational exposure to styrene was studied in 34 workers employed in the production of fiberglass-reinforced plastic sheets and compared to 29 unexposed healthy controls. We evaluated genotoxic effects induced by occupational styrene exposure in lymphocytes by alkaline version of the comet assay to detect single-strand breaks (SSBs), DNA oxidation products (formamido pyrimidine glycosilase (Fpg)- and endonuclease (Endo III)-sensitive sites) and DNA repair kinetics studies, as well as the neutral version of comet assay for DNA double-strand breaks (DSBs). An innovative aspect of this study was the use of immuno-comet assay, a new technique that recognizes DSBs with specific antibody by DAPI/FITC method. The battery of parameters included markers of external and internal exposure. Exposed workers showed significant high levels of SSBs (p0.0001) and DSBs (p0.0001) in neutral- and immuno-comet assay. A drastic decrease in DNA repair activity as compared to controls was observed (180 min vs. 35 min). Styrene workplace concentration significantly correlated with alkaline comet parameters (TM, p=0.013; TI, p=0.008), in negative with TL (p=0.022), and with DNA-base oxidation (TM Endo III, p=0.048 and TI Endo III, p=0.028). There was a significant negative correlation between urinary metabolites (MA+PGA) and TM Endo III (p=0.032) and TI Endo III (p=0.017).
    Tipo de documento:
    Referencia
    Referencia del producto:
    3299

  • The use of human mesenchymal stem cell-derived feeder cells for the cultivation of transplantable epithelial sheets. 19136703

    PURPOSE: To report the efficacy of human bone marrow-derived mesenchymal stem cells as a source of feeder cells for the cultivation of transplantable corneal epithelial cell sheets. METHODS: Human mesenchymal stem cells (marrow adherent stem cells; MASCs) were cultured in alpha-modified Eagle's medium with 10% serum and were treated with mitomycin C. Expression of cytokines in MASCs was confirmed by reverse transcription-polymerase chain reaction. Human limbal epithelial cells were cocultured with MASCs or 3T3 feeder cells to compare colony-forming efficiency (CFE). Limbal epithelial cells were cultured on MASCs or 3T3 feeder cells at the air-liquid interface to allow stratification, and stratified epithelial sheets were analyzed by immunohistochemistry against cytokeratin 3 (K3), K15, p63alpha, and ABCG2. Rabbit limbal epithelial cell sheets were cultivated with MASC feeder cells and transplanted to the ocular surface of the limbal-deficient rabbits. Epithelial grafts were observed by slit lamp microscopy for 4 weeks and then evaluated by histology and immunohistochemistry against K3 and K4. RESULTS: MASC feeder cells expressed keratinocyte growth factor, hepatocyte growth factor, and N-cadherin. The CFE of human limbal epithelial cells was similar in MASC and 3T3 feeder groups. Stratified cell sheets were successfully cultivated with MASC feeder cells expressing K3, K15, p63alpha, and ABCG2. Transplanted epithelial sheets regenerated the corneal phenotype in limbal-deficient rabbits. CONCLUSIONS: MASC-derived feeder cells are suitable for the engineering of epithelial sheets, avoiding the use of potentially hazardous xenologic feeder cells.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB4146

  • Epidermal cell turnover across tight junctions based on Kelvin's tetrakaidecahedron cell shape. 27894419

    In multicellular organisms, cells adopt various shapes, from flattened sheets of endothelium to dendritic neurons, that allow the cells to function effectively. Here, we elucidated the unique shape of cells in the cornified stratified epithelia of the mammalian epidermis that allows them to achieve homeostasis of the tight junction (TJ) barrier. Using intimate in vivo 3D imaging, we found that the basic shape of TJ-bearing cells is a flattened Kelvin's tetrakaidecahedron (f-TKD), an optimal shape for filling space. In vivo live imaging further elucidated the dynamic replacement of TJs on the edges of f-TKD cells that enables the TJ-bearing cells to translocate across the TJ barrier. We propose a spatiotemporal orchestration model of f-TKD cell turnover, where in the classic context of 'form follows function', cell shape provides a fundamental basis for the barrier homeostasis and physical strength of cornified stratified epithelia.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • Membrane properties for permeability testing: Skin versus synthetic membranes 29366943

    Synthetic membranes that are utilized in diffusion studies for topical and transdermal formulations are usually porous thin polymeric sheets for example cellulose acetate (CA) and polysulfones. In this study, the permeability of human skin was compared using two synthetic membranes: cellulose acetate and Strat-M membrane and lipophilic and hydrophilic compounds either as saturated or formulated solutions as well as marketed dosage forms. Our data suggests that hydrophilic compounds have higher permeation in Strat-M membranes compared with lipophilic ones. High variation in permeability values, a typical property of biological membranes, was not observed with Strat-M. In addition, the permeability of Strat-M was closer to that of human skin than that of cellulose acetate. Our results suggest that Strat-M with little or no lot to lot variability can be applied in pilot studies of diffusion tests instead of human skin and is a better substitute than a cellulose acetate.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • Heat shock attenuates VEGF expression in three-dimensional myoblast sheets deteriorating therapeutic efficacy in heart failure. 22129892

    Myoblast sheet transplantation is a promising novel treatment for ischemic heart failure. The aim of this study was to test the hypothesis that heat shock (HS) pre-treatment affects the angiogenic properties of myoblast sheets in vivo and in vitro.We studied HS preconditioning of L6 myoblast sheets in relation to their apoptosis, proliferation, and vascular endothelial growth factor (VEGF)-associated responses under normoxia and under hypoxia in vitro. In vivo evaluation of their therapeutic effect was performed with 60 male Wistar rats divided into 3 groups (20 each): sole left anterior descending (LAD) ligation (control); LAD ligation and non-conditioned sheet transplantation (L6 No-Shock); and LAD ligation and L6-heat shock conditioned sheet transplantation (L6 Heat-Shock). Left ventricular function was evaluated by echocardiography after 3, 10, and 28 days.Expression of HSP70/72 was strongly induced 24 hours after HS, and thereafter it decreased notably during 72 hours in hypoxia. Under normal growth conditions, HSP70/72 expression remained stable. HS delayed apoptosis-associated caspase-3 expression during 24-hour hypoxia compared to non-treated controls. However, VEGF expression reduced significantly in the heat shock pretreated sheets. Ejection fraction of the L6-myoblast HS pre-treatment group (L6 Heat-Shock) decreased gradually during follow-up, in the same pattern as the controls. However, these functional parameters improved in the L6-myoblast normal sheet group (L6 No-Shock) at the tenth day and remained significantly better.HS protects myoblast sheets from hypoxia-associated apoptosis in vitro, but reduces VEGF expression of the sheet, leading to lower therapeutic effect in heart failure.
    Tipo de documento:
    Referencia
    Referencia del producto:
    AB7356
    Nombre del producto:
    Anti-von Willebrand Factor Antibody