Science.gov

Sample records for nutra cells workpackage

  1. Nutra-ergonomics: influence of nutrition on physical employment standards and the health of workers.

    PubMed

    Shearer, Jane; Graham, Terry E; Skinner, Tina L

    2016-06-01

    The importance of ergonomics across several scientific domains, including biomechanics, psychology, sociology, and physiology, have been extensively explored. However, the role of other factors that may influence the health and productivity of workers, such as nutrition, is generally overlooked. Nutra-ergonomics describes the interface between workers, their work environment, and performance in relation to their nutritional status. It considers nutrition to be an integral part of a safe and productive workplace that encompasses physical and mental health as well as the long-term wellbeing of workers. This review explores the knowledge, awareness, and common practices of nutrition, hydration, stimulants, and fortified product use employed prior to physical employment standards testing and within the workplace. The influence of these nutra-ergonomic strategies on physical employment standards, worker safety, and performance will be examined. Further, the roles, responsibilities, and implications for the applicant, worker, and the employer will be discussed within the context of nutra-ergonomics, with reference to the provision and sustainability of an environment conducive to optimize worker health and wellbeing. Beyond physical employment standards, workplace productivity, and performance, the influence of extended or chronic desynchronization (irregular or shift work) in the work schedule on metabolism and long-term health, including risk of developing chronic and complex diseases, is discussed. Finally, practical nutra-ergonomic strategies and recommendations for the applicant, worker, and employer alike will be provided to enhance the short- and long-term safety, performance, health, and wellbeing of workers.

  2. Seed Pro-Nutra Care: A tool for characterization of seed storage proteins and database of bioactive peptides having potential health benefits.

    PubMed

    Kumar, Anil; Goyal, Ajay; Goel, Anshita; Pandey, Dinesh

    2014-01-01

    Seed storage proteins, the major food proteins, possess unique physicochemical characteristics which determine their nutritional importance and influence their utilization by humans. Here, we describe a database driven tool named Seed Pro-Nutra Care which comprises a systematic compendium of seed storage proteins and their bioactive peptides influencing several vital organ systems for maintenance of health. Seed Pro-Nutra Careis an integrated resource on seed storage protein. This resource help in the (I) Characterization of proteins whether they belong to seed storage protein group or not. (II) Identification the bioactive peptides with their sequences using peptide name (III) Determination of physico chemical properties of seed storage proteins. (IV) Epitope identification and mapping (V) Allergenicity prediction and characterization. Seed Pro-Nutra Care is a compilation of data on bioactive peptides present in seed storage proteins from our own collections and other published and unpublished sources. The database provides an information resource of a variety of seed related biological information and its use for nutritional and biomedical application. http://www.gbpuat-cbsh.ac.in/departments/bi/database/seed_pro_nutra_care/

  3. Stem cells in biology and disease - ESTOOLS International Symposium.

    PubMed

    Pistoi, Sergio

    2010-01-01

    ESTOOLS was the first EU-funded project entirely devoted to the study of human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). The final meeting of the consortium took place in Lisbon from 26 to 28 May 2010 and gathered 298 researchers from 27 countries. A dense programme of scientific sessions and outreach activities and an ethics workshop gave an all-round overview of the challenges, perspectives and ethical issues of this exciting field. The ESTOOLS consortium was launched in 2006 as a 4-year EU-funded 6th Framework (FP6) project, with a total funding of 12 million euro. The project has been the largest European consortium devoted to the study of human ESCs, teaming up 21 research groups in 10 countries. After the discovery of human induced pluripotent stem cells (iPSCs) by Shinya Yamanaka and James Thomson in 2007, the consortium opened a new workpackage dedicated to this groundbreaking field, and became the first to devote EU funding to study human iPSCs. The Lisbon meeting marked the end of the consortiums funding cycle, but it was more than a wrap-up of its overall work and achievements, providing a showcase of cutting-edge research in human pluripotent stem cells, with the participation of international leaders in the field.

  4. Stem Cells

    MedlinePlus

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  5. Clinical and biomarker profiling of prodromal Alzheimer's disease in workpackage 5 of the Innovative Medicines Initiative PharmaCog project: a 'European ADNI study'.

    PubMed

    Galluzzi, S; Marizzoni, M; Babiloni, C; Albani, D; Antelmi, L; Bagnoli, C; Bartres-Faz, D; Cordone, S; Didic, M; Farotti, L; Fiedler, U; Forloni, G; Girtler, N; Hensch, T; Jovicich, J; Leeuwis, A; Marra, C; Molinuevo, J L; Nobili, F; Pariente, J; Parnetti, L; Payoux, P; Del Percio, C; Ranjeva, J-P; Rolandi, E; Rossini, P M; Schönknecht, P; Soricelli, A; Tsolaki, M; Visser, P J; Wiltfang, J; Richardson, J C; Bordet, R; Blin, O; Frisoni, G B

    2016-06-01

    In the field of Alzheimer's disease (AD), the validation of biomarkers for early AD diagnosis and for use as a surrogate outcome in AD clinical trials is of considerable research interest. To characterize the clinical profile and genetic, neuroimaging and neurophysiological biomarkers of prodromal AD in amnestic mild cognitive impairment (aMCI) patients enrolled in the IMI WP5 PharmaCog (also referred to as the European ADNI study). A total of 147 aMCI patients were enrolled in 13 European memory clinics. Patients underwent clinical and neuropsychological evaluation, magnetic resonance imaging (MRI), electroencephalography (EEG) and lumbar puncture to assess the levels of amyloid β peptide 1-42 (Aβ42), tau and p-tau, and blood samples were collected. Genetic (APOE), neuroimaging (3T morphometry and diffusion MRI) and EEG (with resting-state and auditory oddball event-related potential (AO-ERP) paradigm) biomarkers were evaluated. Prodromal AD was found in 55 aMCI patients defined by low Aβ42 in the cerebrospinal fluid (Aβ positive). Compared to the aMCI group with high Aβ42 levels (Aβ negative), Aβ positive patients showed poorer visual (P = 0.001), spatial recognition (P < 0.0005) and working (P = 0.024) memory, as well as a higher frequency of APOE4 (P < 0.0005), lower hippocampal volume (P = 0.04), reduced thickness of the parietal cortex (P < 0.009) and structural connectivity of the corpus callosum (P < 0.05), higher amplitude of delta rhythms at rest (P = 0.03) and lower amplitude of posterior cingulate sources of AO-ERP (P = 0.03). These results suggest that, in aMCI patients, prodromal AD is characterized by a distinctive cognitive profile and genetic, neuroimaging and neurophysiological biomarkers. Longitudinal assessment will help to identify the role of these biomarkers in AD progression. © 2016 The Association for the Publication of the Journal of Internal Medicine.

  6. Cells, cells, and more cells.

    PubMed

    Bhatti, M Tariq; Gres, Katherine E; Petitto, Virginia B; Cross, Shelley Ann

    2007-01-01

    A 64-year-old woman presented with bilateral optic nerve swelling, vitreous cells, and cerebrospinal fluid monocytic pleocytosis. A chest radiograph and computed tomography demonstrated a lesion in the left lung, which histologically was confirmed to be a small-cell lung carcinoma. The serum was positive for the anti-CV2 (anti-CRMP-5) antibody. Following treatment with chemoradiation the optic nerve swelling and vitritis resolved. The differential diagnosis of uveal-meningeal diseases is discussed and the pathophysiology and clinical manifestations of paraneoplastic syndromes reviewed.

  7. T Cells

    MedlinePlus

    ... Cells Share this page Facebook Twitter Email T Cells Definition of MS Myelin Immune-Mediated Disease T ... other immune cells. Three broad categories of T cells Helper T cells augment the immune response by ...

  8. Cell division

    MedlinePlus Videos and Cool Tools

    ... the first 12 hours after conception, the fertilized egg cell remains a single cell. After approximately 30 ... at the end of 3 days, the fertilized egg cell has become a berry-like structure made ...

  9. Galvanic Cells

    ERIC Educational Resources Information Center

    Young, I. G.

    1973-01-01

    Many standard physical chemistry textbooks contain ambiguities which lead to confusion about standard electrode potentials, calculating cell voltages, and writing reactions for galvanic cells. This article shows how standard electrode potentials can be used to calculate cell voltages and deduce cell reactions. (Author/RH)

  10. Stem cells.

    PubMed

    Behr, Björn; Ko, Sae Hee; Wong, Victor W; Gurtner, Geoffrey C; Longaker, Michael T

    2010-10-01

    Stem cells are self-renewing cells capable of differentiating into multiple cell lines and are classified according to their origin and their ability to differentiate. Enormous potential exists in use of stem cells for regenerative medicine. To produce effective stem cell-based treatments for a range of diseases, an improved understanding of stem cell biology and better control over stem cell fate are necessary. In addition, the barriers to clinical translation, such as potential oncologic properties of stem cells, need to be addressed. With renewed government support and continued refinement of current stem cell methodologies, the future of stem cell research is exciting and promises to provide novel reconstructive options for patients and surgeons limited by traditional paradigms.

  11. Engineering Cell-Cell Signaling

    PubMed Central

    Milano, Daniel F.; Natividad, Robert J.; Asthagiri, Anand R.

    2014-01-01

    Juxtacrine cell-cell signaling mediated by the direct interaction of adjoining mammalian cells is arguably the mode of cell communication that is most recalcitrant to engineering. Overcoming this challenge is crucial for progress in biomedical applications, such as tissue engineering, regenerative medicine, immune system engineering and therapeutic design. Here, we describe the significant advances that have been made in developing synthetic platforms (materials and devices) and synthetic cells (cell surface engineering and synthetic gene circuits) to modulate juxtacrine cell-cell signaling. In addition, significant progress has been made in elucidating design rules and strategies to modulate juxtacrine signaling based on quantitative, engineering analysis of the mechanical and regulatory role of juxtacrine signals in the context of other cues and physical constraints in the microenvironment. These advances in engineering juxtacrine signaling lay a strong foundation for an integrative approach to utilizing synthetic cells, advanced ‘chassis’ and predictive modeling to engineer the form and function of living tissues. PMID:23856592

  12. Engineering cell-cell signaling.

    PubMed

    Blagovic, Katarina; Gong, Emily S; Milano, Daniel F; Natividad, Robert J; Asthagiri, Anand R

    2013-10-01

    Juxtacrine cell-cell signaling mediated by the direct interaction of adjoining mammalian cells is arguably the mode of cell communication that is most recalcitrant to engineering. Overcoming this challenge is crucial for progress in biomedical applications, such as tissue engineering, regenerative medicine, immune system engineering and therapeutic design. Here, we describe the significant advances that have been made in developing synthetic platforms (materials and devices) and synthetic cells (cell surface engineering and synthetic gene circuits) to modulate juxtacrine cell-cell signaling. In addition, significant progress has been made in elucidating design rules and strategies to modulate juxtacrine signaling on the basis of quantitative, engineering analysis of the mechanical and regulatory role of juxtacrine signals in the context of other cues and physical constraints in the microenvironment. These advances in engineering juxtacrine signaling lay a strong foundation for an integrative approach to utilize synthetic cells, advanced 'chassis' and predictive modeling to engineer the form and function of living tissues.

  13. Fuel cells

    NASA Astrophysics Data System (ADS)

    1984-12-01

    The US Department of Energy (DOE), Office of Fossil Energy, has supported and managed a fuel cell research and development (R and D) program since 1976. Responsibility for implementing DOE's fuel cell program, which includes activities related to both fuel cells and fuel cell systems, has been assigned to the Morgantown Energy Technology Center (METC) in Morgantown, West Virginia. The total United States effort of the private and public sectors in developing fuel cell technology is referred to as the National Fuel Cell Program (NFCP). The goal of the NFCP is to develop fuel cell power plants for base-load and dispersed electric utility systems, industrial cogeneration, and on-site applications. To achieve this goal, the fuel cell developers, electric and gas utilities, research institutes, and Government agencies are working together. Four organized groups are coordinating the diversified activities of the NFCP. The status of the overall program is reviewed in detail.

  14. Cell Phones

    MedlinePlus

    ... These base stations operate at higher power than cell phones. The RF exposures people experience from base stations are typically much lower than from cell phones because base station antennas are mounted on ...

  15. Photoelectrochemical cells

    NASA Astrophysics Data System (ADS)

    Nozik, A. J.

    1980-02-01

    The application of photoelectrochemical systems based on photoactive semiconducting electrodes to the problem of solar energy conversion and chemical synthesis is discussed. Three types of cells are described: electrochemical photovoltaic cells (wherein optical energy is converted into electrical energy); photoelectrolysis cells (wherein optical energy is converted into chemical free energy); and photocatalytic cells (wherein optical energy provides the activation energy for exoergic chemical reactions). The critical semiconductor electrode properties for these cells are the band gap, the flat-band potential, and the photoelectrochemical stability. No semiconductor electrode material is yet known for which all three parameters are simultaneously optimized. An interesting configurational variation of photoelectrolysis cells, labelled 'photochemical diodes', is described. These diodes comprise cells that have been collapsed into monolithic particles containing no external wires. Recent advances in several areas of photoelectrochemical systems are also described.

  16. Types of Stem Cells

    MedlinePlus

    ... Stem Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... Learn About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

  17. Electrolytic cell

    NASA Astrophysics Data System (ADS)

    Bullock, J. S.; Hale, B. D.

    1984-09-01

    An apparatus is described for the separation of the anolyte and the catholyte during electrolysis. The electrolyte flows through an electrolytic cell between the oppositely charged electrodes. The cell is equipped with a wedge-shaped device, the tapered end is located between the electrodes on the effluent side of the cell. The wedge diverts the flow of the electrolyte to either side of the wedge, substantially separating the anolyte and the catholyte.

  18. Cell Chauvinism

    ERIC Educational Resources Information Center

    Keller, Dolores Elaine

    1972-01-01

    Indicates that biological terminology, such as mother cell'' and labels of sex factors in bacteria, reflect discrimination against females by reinforcing perpetuation of stereotyped gender roles. (AL)

  19. Cell Migration

    PubMed Central

    Trepat, Xavier; Chen, Zaozao; Jacobson, Ken

    2015-01-01

    Cell migration is fundamental to establishing and maintaining the proper organization of multicellular organisms. Morphogenesis can be viewed as a consequence, in part, of cell locomotion, from large-scale migrations of epithelial sheets during gastrulation, to the movement of individual cells during development of the nervous system. In an adult organism, cell migration is essential for proper immune response, wound repair, and tissue homeostasis, while aberrant cell migration is found in various pathologies. Indeed, as our knowledge of migration increases, we can look forward to, for example, abating the spread of highly malignant cancer cells, retarding the invasion of white cells in the inflammatory process, or enhancing the healing of wounds. This article is organized in two main sections. The first section is devoted to the single-cell migrating in isolation such as occurs when leukocytes migrate during the immune response or when fibroblasts squeeze through connective tissue. The second section is devoted to cells collectively migrating as part of multicellular clusters or sheets. This second type of migration is prevalent in development, wound healing, and in some forms of cancer metastasis. PMID:23720251

  20. Cell Chauvinism

    ERIC Educational Resources Information Center

    Keller, Dolores Elaine

    1972-01-01

    Indicates that biological terminology, such as mother cell'' and labels of sex factors in bacteria, reflect discrimination against females by reinforcing perpetuation of stereotyped gender roles. (AL)

  1. Unit Cells

    ERIC Educational Resources Information Center

    Olsen, Robert C.; Tobiason, Fred L.

    1975-01-01

    Describes the construction of unit cells using clear plastic cubes which can be disassembled, and one inch cork balls of various colors, which can be cut in halves, quarters, or eighths, and glued on the inside face of the cube, thus simulating a unit cell. (MLH)

  2. Unit Cells

    ERIC Educational Resources Information Center

    Olsen, Robert C.; Tobiason, Fred L.

    1975-01-01

    Describes the construction of unit cells using clear plastic cubes which can be disassembled, and one inch cork balls of various colors, which can be cut in halves, quarters, or eighths, and glued on the inside face of the cube, thus simulating a unit cell. (MLH)

  3. Fuel Cells

    ERIC Educational Resources Information Center

    Hawkins, M. D.

    1973-01-01

    Discusses the theories, construction, operation, types, and advantages of fuel cells developed by the American space programs. Indicates that the cell is an ideal small-scale power source characterized by its compactness, high efficiency, reliability, and freedom from polluting fumes. (CC)

  4. Fuel Cells

    ERIC Educational Resources Information Center

    Hawkins, M. D.

    1973-01-01

    Discusses the theories, construction, operation, types, and advantages of fuel cells developed by the American space programs. Indicates that the cell is an ideal small-scale power source characterized by its compactness, high efficiency, reliability, and freedom from polluting fumes. (CC)

  5. Host cells and cell banking.

    PubMed

    Stacey, Glyn N; Merten, Otto-Wilhelm

    2011-01-01

    Gene therapy based on the use of viral vectors is entirely dependent on the use of animal cell lines, mainly of mammalian origin, but also of insect origin. As for any biotechnology product for clinical use, viral -vectors have to be produced with cells derived from an extensively characterized cell bank to maintain the appropriate standard for assuring the lowest risk for the patients to be treated. Although many different cell types and lines have been used for the production of viral vectors, HEK293 cells or their derivatives have been extensively used for production of different vector types: adenovirus, oncorectrovirus, lentivirus, and AAV vectors, because of their easy handling and the possibility to grow them adherently in serum-containing medium as well as in suspension in serum-free culture medium. Despite this, these cells are not necessarily the best for the production of a given viral vector, and there are many other cell lines with significant advantages including superior growth and/or production characteristics, which have been tested and also used for the production of clinical vector batches. This chapter presents basic -considerations concerning the characterization of cell banks, in the first part, and, in the second part, practically all cell lines (at least when public information was available) established and developed for the production of the most important viral vectors (adenoviral, oncoretroviral, lentiviral, AAV, baculovirus).

  6. Cell polarity

    PubMed Central

    Romereim, Sarah M

    2011-01-01

    Despite extensive genetic analysis of the dynamic multi-phase process that transforms a small population of lateral plate mesoderm into the mature limb skeleton, the mechanisms by which signaling pathways regulate cellular behaviors to generate morphogenetic forces are not known. Recently, a series of papers have offered the intriguing possibility that regulated cell polarity fine-tunes the morphogenetic process via orienting cell axes, division planes and cell movements. Wnt5a-mediated non-canonical signaling, which may include planar cell polarity, has emerged as a common thread in the otherwise distinct signaling networks that regulate morphogenesis in each phase of limb development. These findings position the limb as a key model to elucidate how global tissue patterning pathways direct local differences in cell behavior that, in turn, generate growth and form. PMID:22064549

  7. Fuel cells 101

    SciTech Connect

    Hirschenhofer, J.H.

    1999-07-01

    This paper discusses the various types of fuel cells, the importance of cell voltage, fuel processing for natural gas, cell stacking, fuel cell plant description, advantages and disadvantages of the types of fuel cells, and applications. The types covered include: polymer electrolyte fuel cell, alkaline fuel cell, phosphoric acid fuel cell; molten carbonate fuel cell, and solid oxide fuel cell.

  8. 9. ENGINE TEST CELL BUILDING INTERIOR. CELL ACCESS ELEVATOR, CELLS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. ENGINE TEST CELL BUILDING INTERIOR. CELL ACCESS ELEVATOR, CELLS 2 AND 4, BASEMENT LEVEL. LOOKING SOUTHEAST. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  9. Bi-Cell Unit for Fuel Cell.

    DTIC Science & Technology

    The patent concerns a bi-cell unit for a fuel cell . The bi-cell unit is comprised of two electrode packs. Each of the electrode packs includes an...invention relates in general to a bi-cell unit for a fuel cell and in particular, to a bi-cell unit for a hydrazine-air fuel cell .

  10. Electrochemical cell

    DOEpatents

    Redey, L.I.; Vissers, D.R.; Prakash, J.

    1996-07-16

    An electrochemical cell is described having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm{sup 3}; the cell can be 90% recharged in three hours and can operate at temperatures below 160 C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6{times}10{sup 4}cm{sup 2}/g of Ni. 6 figs.

  11. Electrochemical cell

    DOEpatents

    Redey, L.I.; Vissers, D.R.; Prakash, J.

    1994-02-01

    An electrochemical cell is described having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm[sup 3]; the cell can be 90% recharged in three hours and can operate at temperatures below 160 C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6[times]10[sup 4] cm[sup 2]/g of Ni. 8 figures.

  12. T Cells

    MedlinePlus

    ... Cells d What Causes MS? Disproved Theories Viruses Clusters d Who Gets MS? Pediatric MS African Americans ... Learn More Relapsing-remitting MS (RRMS) Learn More Clusters Learn More Viruses Learn More Disproved Theories Learn ...

  13. Electrochemical cell

    DOEpatents

    Redey, Laszlo I.; Vissers, Donald R.; Prakash, Jai

    1994-01-01

    An electrochemical cell having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm.sup.3 ; the cell can be 90% recharged in three hours and can operate at temperatures below 160.degree. C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6.times.10.sup.4 cm.sup.2 /g of Ni.

  14. Electrochemical cell

    DOEpatents

    Redey, Laszlo I.; Vissers, Donald R.; Prakash, Jai

    1996-01-01

    An electrochemical cell having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm.sup.3 ; the cell can be 90% recharged in three hours and can operate at temperatures below 160.degree. C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6.times.10.sup.4 cm.sup.2 /g of Ni.

  15. Electrochemical cell

    DOEpatents

    Redey, Laszlo I.; Vissers, Donald R.; Prakash, Jai

    1994-01-01

    An electrochemical cell having an alkali metal negative electrode such as sodium and a positive electrode including Ni or transition metals, separated by a .beta." alumina electrolyte and NaAlCl.sub.4 or other compatible material. Various concentrations of a bromine, iodine and/or sulfur containing additive and pore formers are disclosed, which enhance cell capacity and power. The pore formers may be the ammonium salts of carbonic acid or a weak organic acid or oxamide or methylcellulose.

  16. Electrochemical cell

    SciTech Connect

    Maloney, D.E.

    1984-04-24

    A process and cell for electrolysis of alkali metal halides, especially sodium chloride, are described, wherein the anolyte and catholyte compartments are separated by a fluorinated ion-exchange membrane whose surface facing the catholyte compartment is of a polymer having carboxylic functionality and which has a roughness which does not exceed 1.5 microns. Such a cell and process operate at high current efficiency, low voltage and low power consumption.

  17. Solar Cells

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The Heat Exchanger Method (HEM) produces high efficiency crystal ingots in an automated well-insulated furnace offering low equipment, labor and energy costs. The "grown" silicon crystals are used to make solar cells, or photovoltaic cells which convert sunlight directly into electricity. The HEM method is used by Crystal Systems, Inc. and was developed under a NASA/Jet Propulsion Laboratory contract. The square wafers which are the result of the process are sold to companies manufacturing solar panels.

  18. Load cell

    DOEpatents

    Spletzer, Barry L.

    2001-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs which can be combined to determine any one of the six general load components.

  19. Load cell

    DOEpatents

    Spletzer, Barry L.

    1998-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components.

  20. Air cell

    NASA Astrophysics Data System (ADS)

    Okamura, Okiyoshi; Wakasa, Masayuki; Tamanoi, Yoshihito

    1991-04-01

    The present invention relates to an air cell. This air cell provides a compact light-weight power source for model aircraft permitting them to fly for an extended period so that they may be used for such practical purposes as crop dusting, surveying, and photographing. The cell is comprised of a current collector so disposed between a magnesium, zinc, or aluminum alloy cathode and a petroleum graphite anode that it is in contact with the anode. The anode is formed by adding polytetrafluoroethylene dispersion liquid in a mixture of active carbon and graphite powder, pouring the mixture into a mold and heating it to form the anode. It is fabricated by a plurality of anode sections and is formed with at least one hole so that it can provide a cell which is compact in size and light in weight yet is capable of generating a high output. The anode, the cathode, and a separator are wetted by an electrolytic liquid. The electrolyte is continuously supplied through the life of the cell.

  1. Electrochemical cell

    DOEpatents

    Redey, Laszlo I.; Myles, Kevin M.; Vissers, Donald R.; Prakash, Jai

    1996-01-01

    An electrochemical cell with a positive electrode having an electrochemically active layer of at least one transition metal chloride. A negative electrode of an alkali metal and a compatible electrolyte including an alkali metal salt molten at cell operating temperature is included in the cell. The electrolyte is present at least partially as a corrugated .beta." alumina tube surrounding the negative electrode interior to the positive electrode. The ratio of the volume of liquid electrolyte to the volume of the positive electrode is in the range of from about 0.1 to about 3. A plurality of stacked electrochemical cells is disclosed each having a positive electrode, a negative electrode of an alkali metal molten at cell operating temperature, and a compatible electrolyte. The electrolyte is at least partially present as a corrugated .beta." alumina sheet separating the negative electrode and interior to the positive electrodes. The alkali metal is retained in a porous electrically conductive ceramic, and seals for sealing the junctures of the electrolyte and the adjacent electrodes at the peripheries thereof.

  2. Electrochemical cell

    DOEpatents

    Nagy, Zoltan; Yonco, Robert M.; You, Hoydoo; Melendres, Carlos A.

    1992-01-01

    An electrochemical cell has a layer-type or sandwich configuration with a Teflon center section that houses working, reference and counter electrodes and defines a relatively narrow electrolyte cavity. The center section is surrounded on both sides with thin Teflon membranes. The membranes are pressed in place by a pair of Teflon inner frames which are in turn supported by a pair of outer metal frames. The pair of inner and outer frames are provided with corresponding, appropriately shaped slits that are in plane generally transverse to the plane of the working electrode and permit X-ray beams to enter and exit the cell through the Teflon membranes that cover the slits so that the interface between the working electrode and the electrolyte within the cell may be analyzed by transmission geometry. In one embodiment, the center section consists of two parts, one on top of the other. Alternatively, the center section of the electrochemical cell may consist of two intersliding pieces or may be made of a single piece of Teflon sheet material. The electrolyte cavity is shaped so that the electrochemical cell can be rotated 90.degree. in either direction while maintaining the working and counter electrodes submerged in the electrolyte.

  3. Electrochemical cell

    DOEpatents

    Nagy, Z.; Yonco, R.M.; You, H.; Melendres, C.A.

    1992-08-25

    An electrochemical cell has a layer-type or sandwich configuration with a Teflon center section that houses working, reference and counter electrodes and defines a relatively narrow electrolyte cavity. The center section is surrounded on both sides with thin Teflon membranes. The membranes are pressed in place by a pair of Teflon inner frames which are in turn supported by a pair of outer metal frames. The pair of inner and outer frames are provided with corresponding, appropriately shaped slits that are in plane generally transverse to the plane of the working electrode and permit X-ray beams to enter and exit the cell through the Teflon membranes that cover the slits so that the interface between the working electrode and the electrolyte within the cell may be analyzed by transmission geometry. In one embodiment, the center section consists of two parts, one on top of the other. Alternatively, the center section of the electrochemical cell may consist of two intersliding pieces or may be made of a single piece of Teflon sheet material. The electrolyte cavity is shaped so that the electrochemical cell can be rotated 90[degree] in either direction while maintaining the working and counter electrodes submerged in the electrolyte. 5 figs.

  4. Electrochemical cell

    DOEpatents

    Redey, L.I.; Myles, K.M.; Vissers, D.R.; Prakash, J.

    1996-07-02

    An electrochemical cell is described with a positive electrode having an electrochemically active layer of at least one transition metal chloride. A negative electrode of an alkali metal and a compatible electrolyte including an alkali metal salt molten at cell operating temperature is included in the cell. The electrolyte is present at least partially as a corrugated {beta}{double_prime} alumina tube surrounding the negative electrode interior to the positive electrode. The ratio of the volume of liquid electrolyte to the volume of the positive electrode is in the range of from about 0.1 to about 3. A plurality of stacked electrochemical cells is disclosed each having a positive electrode, a negative electrode of an alkali metal molten at cell operating temperature, and a compatible electrolyte. The electrolyte is at least partially present as a corrugated {beta}{double_prime} alumina sheet separating the negative electrode and interior to the positive electrodes. The alkali metal is retained in a porous electrically conductive ceramic, and seals for sealing the junctures of the electrolyte and the adjacent electrodes at the peripheries thereof. 8 figs.

  5. Cell Phones

    PubMed Central

    Sansone, Lori A.

    2013-01-01

    Cell phones are a relatively novel and evolving technology. While the potential benefits of this technology continue to emerge, so do the potential psychosocial risks. For example, one psychosocial risk is user stress, which appears to be related to feeling compelled to promptly respond to cell-phone activity in order to maintain spontaneity and access with others. Other potential psychosocial risks include disruptions in sleep; the user’s risk of exposure to cyberbullying, particularly the unwanted exposure of photographs and/or videos of the victim; and overuse, particularly among adolescents. With regard to the latter phenomenon, the boundaries among overuse, misuse, dependence, and addiction are not scientifically clear. Therefore, while cell phones are a convenient and expedient technology, they are not without their potential psychosocial hazards. PMID:23439568

  6. Electrochemical cell

    DOEpatents

    Kaun, Thomas D.

    1984-01-01

    An improved secondary electrochemical cell is disclosed having a negative electrode of lithium aluminum, a positive electrode of iron sulfide, a molten electrolyte of lithium chloride and potassium chloride, and the combination that the fully charged theoretical capacity of the negative electrode is in the range of 0.5-1.0 that of the positive electrode. The cell thus is negative electrode limiting during discharge cycling. Preferably, the negative electrode contains therein, in the approximate range of 1-10 volume % of the electrode, an additive from the materials of graphitized carbon, aluminum-iron alloy, and/or magnesium oxide.

  7. Electrochemical cell

    DOEpatents

    Redey, L.I.; Vissers, D.R.; Prakash, J.

    1994-08-23

    An electrochemical cell is described having an alkali metal negative electrode such as sodium and a positive electrode including Ni or transition metals, separated by a [beta] alumina electrolyte and NaAlCl[sub 4] or other compatible material. Various concentrations of a bromine, iodine and/or sulfur containing additive and pore formers are disclosed, which enhance cell capacity and power. The pore formers may be the ammonium salts of carbonic acid or a weak organic acid or oxamide or methylcellulose. 6 figs.

  8. Electrochemical cell

    DOEpatents

    Kaun, T.D.

    An improved secondary electrochemical cell is disclosed having a negative electrode of lithium aluminum, a positive electrode of iron sulfide, a molten electrolyte of lithium chloride and potassium chloride, and the combination that the fully charged theoretical capacity of the negative electrode is in the range of 0.5 to 1.0 that of the positive electrode. The cell thus is negative electrode limiting during discharge cycling. Preferably, the negative electrode contains therein, in the approximate range of 1 to 10 volume % of the electrode, an additive from the materials of graphitized carbon, aluminum-iron alloy, and/or magnesium oxide.

  9. Cell Libraries

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A NASA contract led to the development of faster and more energy efficient semiconductor materials for digital integrated circuits. Gallium arsenide (GaAs) conducts electrons 4-6 times faster than silicon and uses less power at frequencies above 100-150 megahertz. However, the material is expensive, brittle, fragile and has lacked computer automated engineering tools to solve this problem. Systems & Processes Engineering Corporation (SPEC) developed a series of GaAs cell libraries for cell layout, design rule checking, logic synthesis, placement and routing, simulation and chip assembly. The system is marketed by Compare Design Automation.

  10. Stem Cell Information: Glossary

    MedlinePlus

    ... a fluid-filled cavity (the blastocoel ), and a cluster of cells on the interior (the inner cell ... the female body. Inner cell mass (ICM) —The cluster of cells inside the blastocyst . These cells give ...

  11. Photoelectrodialytic cell

    DOEpatents

    Murphy, G.W.

    1983-09-13

    A multicompartment photoelectrodialytic demineralization cell is provided with a buffer compartment interposed between the product compartment and a compartment containing an electrolyte solution. Semipermeable membranes separate the buffer compartment from the product and electrolyte compartments. The buffer compartment is flushed to prevent leakage of the electrolyte compartment from entering the product compartment. 3 figs.

  12. Photovoltaic cell

    DOEpatents

    Gordon, Roy G.; Kurtz, Sarah

    1984-11-27

    In a photovoltaic cell structure containing a visibly transparent, electrically conductive first layer of metal oxide, and a light-absorbing semiconductive photovoltaic second layer, the improvement comprising a thin layer of transition metal nitride, carbide or boride interposed between said first and second layers.

  13. Potent Cells

    ERIC Educational Resources Information Center

    Liu, Dennis

    2007-01-01

    It seems hard to believe that Dolly the cloned sheep was born 10 years ago, kindling furious arguments over the prospects and ethics of cloning a human. Today, the controversy over cloning is entwined, often confused, with concerns over the use of human embryonic stem cells. Most people are unclear what cloning is, and they know even less when it…

  14. Potent Cells

    ERIC Educational Resources Information Center

    Liu, Dennis

    2007-01-01

    It seems hard to believe that Dolly the cloned sheep was born 10 years ago, kindling furious arguments over the prospects and ethics of cloning a human. Today, the controversy over cloning is entwined, often confused, with concerns over the use of human embryonic stem cells. Most people are unclear what cloning is, and they know even less when it…

  15. Nonaqueous cell

    SciTech Connect

    Brand, L.E.; Chi, I.; Granstaff, S.M. Jr.; Vyas, B.

    1988-06-28

    A nonaqueous cell is described comprising lithium negative electrode, positive electrode comprising active material and electrolyte comprising solvent and current carrying species characterized in that the solvent comprises at least 15 mole percent ethylene carbonate, at least 15 mole percent propylene carbonate and at least 15 mole percent polyethylene glycol dialkyl ether.

  16. 19. Oblique, typical cell (south cells) from rear of cell; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Oblique, typical cell (south cells) from rear of cell; view to north, 65mm lens with electronic flash illumination. - Tule Lake Project Jail, Post Mile 44.85, State Route 139, Newell, Modoc County, CA

  17. Cell Proliferation, Cell Death, and Size Regulation

    DTIC Science & Technology

    1998-10-01

    Cell Death , and Size Regulation PRINCIPAL INVESTIGATOR: Nicholas E. Baker, Ph.D. CONTRACTING ORGANIZATION: Albert Einstein College of Medicine of Yeshiva...SUBTITLE 5. FUNDING NUMBERS Cell Proliferation, Cell Death , and Size Regulation DAMD17-97-1-7034 6. AUTHOR(S) Nicholas E. Baker, Ph.D. 7. PERFORMING...Contains unpublished data 5 CELL PROLIFERATION, CELL DEATH , AND SIZE REGULATION INTRODUCTION Cell proliferation and cell death come to attention through

  18. Electrochemical cell

    SciTech Connect

    Walsh, F.M.

    1986-12-23

    This patent describes an electrochemical cell having a metal anode wherein the metal is selected from zinc and cadmium; a bromine cathode; and an aqueous electrolyte containing a metal bromide, the metal bromide having the same metal as the metal of the anode. The improvement described here comprises: a bromine complexing agent in the aqueous metal bromide electrolyte, the complexing agent consisting solely of a quaternary ammonium salt of an N-organo substituted alpha amino acid, ester, or betaine.

  19. Eukaryotic cells and their cell bodies: Cell Theory revised.

    PubMed

    Baluska, Frantisek; Volkmann, Dieter; Barlow, Peter W

    2004-07-01

    Cell Theory, also known as cell doctrine, states that all eukaryotic organisms are composed of cells, and that cells are the smallest independent units of life. This Cell Theory has been influential in shaping the biological sciences ever since, in 1838/1839, the botanist Matthias Schleiden and the zoologist Theodore Schwann stated the principle that cells represent the elements from which all plant and animal tissues are constructed. Some 20 years later, in a famous aphorism Omnis cellula e cellula, Rudolf Virchow annunciated that all cells arise only from pre-existing cells. General acceptance of Cell Theory was finally possible only when the cellular nature of brain tissues was confirmed at the end of the 20th century. Cell Theory then rapidly turned into a more dogmatic cell doctrine, and in this form survives up to the present day. In its current version, however, the generalized Cell Theory developed for both animals and plants is unable to accommodate the supracellular nature of higher plants, which is founded upon a super-symplasm of interconnected cells into which is woven apoplasm, symplasm and super-apoplasm. Furthermore, there are numerous examples of multinucleate coenocytes and syncytia found throughout the eukaryote superkingdom posing serious problems for the current version of Cell Theory. To cope with these problems, we here review data which conform to the original proposal of Daniel Mazia that the eukaryotic cell is composed of an elemental Cell Body whose structure is smaller than the cell and which is endowed with all the basic attributes of a living entity. A complement to the Cell Body is the Cell Periphery Apparatus, which consists of the plasma membrane associated with other periphery structures. Importantly, boundary structures of the Cell Periphery Apparatus, although capable of some self-assembly, are largely produced and maintained by Cell Body activities and can be produced from it de novo. These boundary structures serve not only as

  20. Dry cell battery poisoning

    MedlinePlus

    Acidic dry cell batteries contain: Manganese dioxide Ammonium chloride Alkaline dry cell batteries contain: Sodium hydroxide Potassium hydroxide Lithium dioxide dry cell batteries contain: Manganese dioxide

  1. Red blood cells, multiple sickle cells (image)

    MedlinePlus

    Sickle cell anemia is an inherited disorder in which abnormal hemoglobin (the red pigment inside red blood cells) is produced. The abnormal hemoglobin causes red blood cells to assume a sickle shape, like the ones seen in this photomicrograph.

  2. Antiparietal cell antibody test

    MedlinePlus

    APCA; Anti-gastric parietal cell antibody; Atrophic gastritis - anti-gastric parietal cell antibody; Gastric ulcer - anti-gastric parietal cell antibody; Pernicious anemia - anti-gastric parietal cell antibody; Vitamin B12 - anti-gastric ...

  3. Stem Cell Basics

    MedlinePlus

    ... healthy cells replace damaged cells in adult organisms. Stem cell research is one of the most fascinating areas of ... as with many expanding fields of scientific inquiry, research on stem cells raises scientific questions as rapidly as it generates ...

  4. Murine Mueller cells are progenitor cells for neuronal cells and fibrous tissue cells

    SciTech Connect

    Florian, Christian; Langmann, Thomas; Weber, Bernhard H.F.; Morsczeck, Christian

    2008-09-19

    Mammalian Mueller cells have been reported to possess retinal progenitor cell properties and generate new neurons after injury. This study investigates murine Mueller cells under in vitro conditions for their capability of dedifferentiation into retinal progenitor cells. Mueller cells were isolated from mouse retina, and proliferating cells were expanded in serum-containing medium. For dedifferentiation, the cultured cells were transferred to serum-replacement medium (SRM) at different points in time after their isolation. Interestingly, early cell passages produced fibrous tissue in which extracellular matrix proteins and connective tissue markers were differentially expressed. In contrast, aged Mueller cell cultures formed neurospheres in SRM that are characteristic for neuronal progenitor cells. These neurospheres differentiated into neuron-like cells after cultivation on laminin/ornithine cell culture substrate. Here, we report for the first time that murine Mueller cells can be progenitors for both, fibrous tissue cells and neuronal cells, depending on the age of the cell culture.

  5. Giant Cell Arteritis

    MedlinePlus

    ... Patient / Caregiver Diseases & Conditions Giant Cell Arteritis Giant Cell Arteritis Fast Facts Giant cell arteritis (GCA) is ... polymyalgia rheumatica (also called PMR). What is giant cell arteritis? GCA is a type of vasculitis or ...

  6. CORONAL CELLS

    SciTech Connect

    Sheeley, N. R. Jr.; Warren, H. P. E-mail: harry.warren@nrl.navy.mil

    2012-04-10

    We have recently noticed cellular features in Fe XII 193 A images of the 1.2 MK corona. They occur in regions bounded by a coronal hole and a filament channel, and are centered on flux elements of the photospheric magnetic network. Like their neighboring coronal holes, these regions have minority-polarity flux that is {approx}0.1-0.3 times their flux of majority polarity. Consequently, the minority-polarity flux is 'grabbed' by the majority-polarity flux to form low-lying loops, and the remainder of the network flux escapes to connect with its opposite-polarity counterpart in distant active regions of the Sun. As these regions are carried toward the limb by solar rotation, the cells disappear and are replaced by linear plumes projecting toward the limb. In simultaneous views from the Solar Terrestrial Relations Observatory and Solar Dynamics Observatory spacecraft, these plumes project in opposite directions, extending away from the coronal hole in one view and toward the hole in the other view, suggesting that they are sky-plane projections of the same radial structures. We conclude that these regions are composed of closely spaced radial plumes, extending upward like candles on a birthday cake and visible as cells when seen from above. We suppose that a coronal hole has this same discrete, cellular magnetic structure, but that it is not seen until the encroachment of opposite-polarity flux closes part or all of the hole.

  7. Ion Channels, Cell Volume, Cell Proliferation and Apoptotic Cell Death

    NASA Astrophysics Data System (ADS)

    Lang, Florian; Gulbins, Erich; Szabo, Ildiko; Vereninov, Alexey; Huber, Stephan M.

    At some stage cell proliferation requires an increase in cell volume and a typical hallmark of apoptotic cell death is cell shrinkage. The respective alterations of cell volume are accomplished by altered regulation of ion transport including ion channels. Thus, cell proliferation and apoptosis are both paralleled by altered activity of ion channels, which play an active part in these fundamental cellular mechanisms. Activation of anion channels allows exit of Cl?, osmolyte and HCO3 ? leading to cell shrinkage and acidification of the cytosol. K+ exit through K+ channels leads to cell shrinkage and a decrease in intracellular K+ concentration. K+ channel activity is further important for maintenance of the cell membrane potential - a critical determinant of Ca2+ entry through Ca2+ channels. Cytosolic Ca2+ may both activate mechanisms required for cell proliferation and stimulate enzymes executing apoptosis. The effect of enhanced cytosolic Ca2+ activity depends on the magnitude and temporal organisation of Ca2+ entry. Moreover, a given ion channel may support both cell proliferation and apoptosis, and specific ion channel blockers may abrogate both fundamental cellular mechanisms, depending on cell type, regulatory environment and condition of the cell. Clearly, further experimental effort is needed to clarify the role of ion channels in the regulation of cell proliferation and apoptosis.

  8. Molluscan cells in culture: primary cell cultures and cell lines

    PubMed Central

    Yoshino, T. P.; Bickham, U.; Bayne, C. J.

    2013-01-01

    In vitro cell culture systems from molluscs have significantly contributed to our basic understanding of complex physiological processes occurring within or between tissue-specific cells, yielding information unattainable using intact animal models. In vitro cultures of neuronal cells from gastropods show how simplified cell models can inform our understanding of complex networks in intact organisms. Primary cell cultures from marine and freshwater bivalve and gastropod species are used as biomonitors for environmental contaminants, as models for gene transfer technologies, and for studies of innate immunity and neoplastic disease. Despite efforts to isolate proliferative cell lines from molluscs, the snail Biomphalaria glabrata Say, 1818 embryonic (Bge) cell line is the only existing cell line originating from any molluscan species. Taking an organ systems approach, this review summarizes efforts to establish molluscan cell cultures and describes the varied applications of primary cell cultures in research. Because of the unique status of the Bge cell line, an account is presented of the establishment of this cell line, and of how these cells have contributed to our understanding of snail host-parasite interactions. Finally, we detail the difficulties commonly encountered in efforts to establish cell lines from molluscs and discuss how these difficulties might be overcome. PMID:24198436

  9. DNA-cell conjugates

    DOEpatents

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2016-05-03

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  10. Indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Weinberg, Irving

    1991-01-01

    The direction for InP solar cell research; reduction of cell cost; increase of cell efficiency; measurements needed to better understand cell performance; n/p versus p/n; radiation effects; major problems in cell contacting; and whether the present level of InP solar cell research in the USA should be maintained, decreased, or increased were considered.

  11. Can mesenchymal cells undergo collective cell migration?

    PubMed Central

    Theveneau, Eric

    2011-01-01

    Cell migration is critical for proper development of the embryo and is also used by many cell types to perform their physiological function. For instance, cell migration is essential for immune cells to monitor the body and for epithelial cells to heal a wound whereas, in cancer cells, acquisition of migratory capabilities is a critical step toward malignancy. Migratory cells are often categorized into two groups: (1) mesenchymal cells, produced by an epithelium-to-mesenchyme transition, that undergo solitary migration and (2) epithelial-like cells which migrate collectively. However, on some occasions, mesenchymal cells may travel in large, dense groups and exhibit key features of collectively migrating cells such as coordination and cooperation. Here, using data published on neural crest cells, a highly invasive mesenchymal cell population that extensively migrate throughout the embryo, we explore the idea that mesenchymal cells, including cancer cells, might be able to undergo collective cell migration under certain conditions and discuss how they could do so. PMID:22274714

  12. Cell cycle regulation in hematopoietic stem cells.

    PubMed

    Pietras, Eric M; Warr, Matthew R; Passegué, Emmanuelle

    2011-11-28

    Hematopoietic stem cells (HSCs) give rise to all lineages of blood cells. Because HSCs must persist for a lifetime, the balance between their proliferation and quiescence is carefully regulated to ensure blood homeostasis while limiting cellular damage. Cell cycle regulation therefore plays a critical role in controlling HSC function during both fetal life and in the adult. The cell cycle activity of HSCs is carefully modulated by a complex interplay between cell-intrinsic mechanisms and cell-extrinsic factors produced by the microenvironment. This fine-tuned regulatory network may become altered with age, leading to aberrant HSC cell cycle regulation, degraded HSC function, and hematological malignancy.

  13. Fuel cell

    SciTech Connect

    Struthers, R.C.

    1983-06-28

    An improved fuel cell comprising an anode section including an anode terminal, an anode fuel, and an anolyte electrolyte, a cathode section including a cathode terminal, an electron distributor and a catholyte electrolyte, an ion exchange section between the anode and cathode sections and including an ionolyte electrolyte, ion transfer membranes separating the ionolyte from the anolyte and the catholyte and an electric circuit connected with and between the terminals conducting free electrons from the anode section and delivering free electrons to the cathode section, said ionolyte receives ions of one polarity moving from the anolyte through the membrane related thereto preventing chemical equilibrium in the anode section and sustaining chemical reaction and the generating of free electrons therein, said ions received by the ionolyte from the anolyte release different ions from the ionolyte which move through the membrane between the ionolyte and catholyte and which add to the catholyte.

  14. Photoelectrochemical cell

    DOEpatents

    Rauh, R. David; Boudreau, Robert A.

    1983-06-14

    A photoelectrochemical cell comprising a sealed container having a light-transmitting window for admitting light into the container across a light-admitting plane, an electrolyte in the container, a photoelectrode in the container having a light-absorbing surface arranged to receive light from the window and in contact with the electrolyte, the surface having a plurality of spaced portions oblique to the plane, each portion having dimensions at least an order of magnitude larger than the maximum wavelength of incident sunlight, the total surface area of the surface being larger than the area of the plane bounded by the container, and a counter electrode in the container in contact with the electrolyte.

  15. CellTracks: Cell analysis system for rare cell detection

    NASA Astrophysics Data System (ADS)

    Kagan, Michael T.; Trainer, Michael N.; Bendele, Teresa; Rao, Chandra; Horton, Allen; Tibbe, Arjan G.; Greve, Jan; Terstappen, Leon W. M. M.

    2002-06-01

    The CellTracks system is a Compact Disk-based cell analyzer that, similar to flow cytometry, differentiates cells that are aligned while passing through focused laser beams. In CellTracks, only immuno-magnetically labeled cells are aligned and remain in position for further analysis. This feature is important in those cases were the cells are relatively infrequent. Epithelium derived tumor cells in peripheral blood are extremely rare but can be present in the blood of cancer patients. The certainty that an event present in a gate is, indeed, an epithelial cell with the assumed characteristics diminishes with the number of events in the analysis gate. Additional and preferably independent information on the individual events aids in the correct classification of the event as an epithelium derived tumor cell. Epithelial cells are immuno-magnetically selected from 7.5 mL of blood and magnetically aligned in the sample chamber between a series of parallel thin film nickel lines. The CD head scans along all nickel lines and captures the fluorescence signals of the objects between the lines. Objects that immuno-phenotypically classify as epithelial tumor cells are revisited for imaging to determine if the identified objects indeed classify as epithelial tumors cells or as debris derived from epithelial cells.

  16. NKT Cell Responses to B Cell Lymphoma

    PubMed Central

    Li, Junxin; Sun, Wenji; Subrahmanyam, Priyanka B.; Page, Carly; Younger, Kenisha M.; Tiper, Irina V.; Frieman, Matthew; Kimball, Amy S.; Webb, Tonya J.

    2014-01-01

    Natural killer T (NKT) cells are a unique subset of CD1d-restricted T lymphocytes that express characteristics of both T cells and natural killer cells. NKT cells mediate tumor immune-surveillance; however, NKT cells are numerically reduced and functionally impaired in lymphoma patients. Many hematologic malignancies express CD1d molecules and co-stimulatory proteins needed to induce anti-tumor immunity by NKT cells, yet most tumors are poorly immunogenic. In this study, we sought to investigate NKT cell responses to B cell lymphoma. In the presence of exogenous antigen, both mouse and human NKT cell lines produce cytokines following stimulation by B cell lymphoma lines. NKT cell populations were examined ex vivo in mouse models of spontaneous B cell lymphoma, and it was found that during early stages, NKT cell responses were enhanced in lymphoma-bearing animals compared to disease-free animals. In contrast, in lymphoma-bearing animals with splenomegaly and lymphadenopathy, NKT cells were functionally impaired. In a mouse model of blastoid variant mantle cell lymphoma, treatment of tumor-bearing mice with a potent NKT cell agonist, α-galactosylceramide (α-GalCer), resulted in a significant decrease in disease pathology. Ex vivo studies demonstrated that NKT cells from α-GalCer treated mice produced IFN-γ following α-GalCer restimulation, unlike NKT cells from vehicle-control treated mice. These data demonstrate an important role for NKT cells in the immune response to an aggressive hematologic malignancy like mantle cell lymphoma. PMID:24955247

  17. Integrated circuit cell library

    NASA Technical Reports Server (NTRS)

    Whitaker, Sterling R. (Inventor); Miles, Lowell H. (Inventor)

    2005-01-01

    According to the invention, an ASIC cell library for use in creation of custom integrated circuits is disclosed. The ASIC cell library includes some first cells and some second cells. Each of the second cells includes two or more kernel cells. The ASIC cell library is at least 5% comprised of second cells. In various embodiments, the ASIC cell library could be 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more comprised of second cells.

  18. Automated Cell-Cutting for Cell Cloning

    NASA Astrophysics Data System (ADS)

    Ichikawa, Akihiko; Tanikawa, Tamio; Matsukawa, Kazutsugu; Takahashi, Seiya; Ohba, Kohtaro

    We develop an automated cell-cutting technique for cell cloning. Animal cells softened by the cytochalasin treatment are injected into a microfluidic chip. The microfluidic chip contains two orthogonal channels: one microchannel is wide, used to transport cells, and generates the cutting flow; the other is thin and used for aspiration, fixing, and stretching of the cell. The injected cell is aspirated and stretched in the thin microchannel. Simultaneously, the volumes of the cell before and after aspiration are calculated; the volumes are used to calculate the fluid flow required to aspirate half the volume of the cell into the thin microchannel. Finally, we apply a high-speed flow in the orthogonal microchannel to bisect the cell. This paper reports the cutting process, the cutting system, and the results of the experiment.

  19. Electrochemical cell

    SciTech Connect

    Notten, P.H.L.

    1991-12-10

    This patent describes an electrochemical cell comprising a negative electrode. It comprises an electrochemical active material consisting of an intermetallic compound of the formula AB{sub m}C{sub n} wherein m plus n is between 4.8 and 5.4, n has a value of up to 0.6 and greater than 0, A is a Mischmetall or at least one element of the group consisting of Y, Ti, Hf, Zr, Ca, Th, La and the remaining rare earth metals, B is at least two elements selected from the group consisting of Ni, Co, Cu, Fe and Mn and C consists of at least one element selected from the group consisting of Al, Cr, and Si, and has a CaCu{sub 5} structure, and a catalytic material at the surface of which hydrogen exhibits a large electrochemical activity, the catalytic material having a composition of formula DE{sub 3} wherein D is at least one element selected from the group consisting of Cr, Mo and W and E is at least one element selected from the group consisting of Ni and Co.

  20. Cell tracking for cell image analysis

    NASA Astrophysics Data System (ADS)

    Bise, Ryoma; Sato, Yoichi

    2017-04-01

    Cell image analysis is important for research and discovery in biology and medicine. In this paper, we present our cell tracking methods, which is capable of obtaining fine-grain cell behavior metrics. In order to address difficulties under dense culture conditions, where cell detection cannot be done reliably since cell often touch with blurry intercellular boundaries, we proposed two methods which are global data association and jointly solving cell detection and association. We also show the effectiveness of the proposed methods by applying the method to the biological researches.

  1. Tumor cell "dead or alive": caspase and survivin regulate cell death, cell cycle and cell survival.

    PubMed

    Suzuki, A; Shiraki, K

    2001-04-01

    Cell death and cell cycle progression are two sides of the same coin, and these two different phenomenons are regulated moderately to maintain the cellular homeostasis. Tumor is one of the disease states produced as a result of the disintegrated regulation and is characterized as cells showing an irreversible progression of cell cycle and a resistance to cell death signaling. Several investigations have been performed for the understanding of cell death or cell cycle, and cell death research has remarkably progressed in these 10 years. Caspase is a nomenclature referring to ICE/CED-3 cysteine proteinase family and plays a central role during cell death. Recently, several investigations raised some possible hypotheses that caspase is also involved in cell cycle regulation. In this issue, therefore, we review the molecular basis of cell death and cell cycle regulated by caspase in tumor, especially hepatocellular carcinoma cells.

  2. Fuel cell arrangement

    DOEpatents

    Isenberg, Arnold O.

    1987-05-12

    A fuel cell arrangement is provided wherein cylindrical cells of the solid oxide electrolyte type are arranged in planar arrays where the cells within a plane are parallel. Planes of cells are stacked with cells of adjacent planes perpendicular to one another. Air is provided to the interior of the cells through feed tubes which pass through a preheat chamber. Fuel is provided to the fuel cells through a channel in the center of the cell stack; the fuel then passes the exterior of the cells and combines with the oxygen-depleted air in the preheat chamber.

  3. Fuel cell arrangement

    DOEpatents

    Isenberg, A.O.

    1987-05-12

    A fuel cell arrangement is provided wherein cylindrical cells of the solid oxide electrolyte type are arranged in planar arrays where the cells within a plane are parallel. Planes of cells are stacked with cells of adjacent planes perpendicular to one another. Air is provided to the interior of the cells through feed tubes which pass through a preheat chamber. Fuel is provided to the fuel cells through a channel in the center of the cell stack; the fuel then passes the exterior of the cells and combines with the oxygen-depleted air in the preheat chamber. 3 figs.

  4. Nanostructured Solar Cells.

    PubMed

    Chen, Guanying; Ning, Zhijun; Ågren, Hans

    2016-08-09

    We are glad to announce the Special Issue "Nanostructured Solar Cells", published in Nanomaterials. This issue consists of eight articles, two communications, and one review paper, covering major important aspects of nanostructured solar cells of varying types. From fundamental physicochemical investigations to technological advances, and from single junction solar cells (silicon solar cell, dye sensitized solar cell, quantum dots sensitized solar cell, and small molecule organic solar cell) to tandem multi-junction solar cells, all aspects are included and discussed in this issue to advance the use of nanotechnology to improve the performance of solar cells with reduced fabrication costs.

  5. Sickle Cell Anemia

    MedlinePlus

    Sickle cell anemia is a disease in which your body produces abnormally shaped red blood cells. The cells are shaped like a crescent or sickle. They don' ... problem causes sickle cell anemia. People with the disease are born with two sickle cell genes, one ...

  6. Cell death pathways in directly irradiated cells and cells exposed to medium from irradiated cells.

    PubMed

    Jella, Kishore Kumar; Garcia, Amaya; McClean, Brendan; Byrne, Hugh J; Lyng, Fiona M

    2013-03-01

    The aim of this study was to compare levels of apoptosis, necrosis, mitotic cell death and senescence after treatment with both direct radiation and irradiated cell conditioned medium. Human keratinocytes (HaCaT cell line) were irradiated (0.005, 0.05 and 0.5 Gy) using a cobalt 60 teletherapy unit. For bystander experiments, the medium was harvested from donor HaCaT cells 1 hour after irradiation and transferred to recipient HaCaT cells. Clonogenic assay, apoptosis, necrosis, mitotic cell death, senescence and cell cycle analysis were measured in both directly irradiated cells and bystander cells A reduction in cell survival was observed for both directly irradiated cells and irradiated cell conditioned medium (ICCM)-treated cells. Early apoptosis and necrosis was observed predominantly after direct irradiation. An increase in the number of cells in G2/M phase was observed at 6 and 12 h which led to mitotic cell death after 72 h following direct irradiation and ICCM treatment. No senescence was observed in the HaCaT cell line following either direct irradiation or treatment with ICCM. This study has shown that directly irradiated cells undergo apoptosis, necrosis and mitotic cell death whereas ICCM-treated cells predominantly undergo mitotic cell death.

  7. Deformability of Tumor Cells versus Blood Cells

    PubMed Central

    Shaw Bagnall, Josephine; Byun, Sangwon; Begum, Shahinoor; Miyamoto, David T.; Hecht, Vivian C.; Maheswaran, Shyamala; Stott, Shannon L.; Toner, Mehmet; Hynes, Richard O.; Manalis, Scott R.

    2015-01-01

    The potential for circulating tumor cells (CTCs) to elucidate the process of cancer metastasis and inform clinical decision-making has made their isolation of great importance. However, CTCs are rare in the blood, and universal properties with which to identify them remain elusive. As technological advancements have made single-cell deformability measurements increasingly routine, the assessment of physical distinctions between tumor cells and blood cells may provide insight into the feasibility of deformability-based methods for identifying CTCs in patient blood. To this end, we present an initial study assessing deformability differences between tumor cells and blood cells, indicated by the length of time required for them to pass through a microfluidic constriction. Here, we demonstrate that deformability changes in tumor cells that have undergone phenotypic shifts are small compared to differences between tumor cell lines and blood cells. Additionally, in a syngeneic mouse tumor model, cells that are able to exit a tumor and enter circulation are not required to be more deformable than the cells that were first injected into the mouse. However, a limited study of metastatic prostate cancer patients provides evidence that some CTCs may be more mechanically similar to blood cells than to typical tumor cell lines. PMID:26679988

  8. Making new beta cells from stem cells.

    PubMed

    Colman, Alan

    2004-06-01

    In 2000, Shapiro et al. provided compelling "proof of principle" data showing that the transplantation of human islets, purified from cadaveric material, could restore severely diabetic, Type 1 patients to insulin independence. This demonstration prompted renewed efforts to find an alternative and sustainable source of surrogate islet cells for cell therapy. Experiments involving adult ductal and liver "stem" cells, or embryonic stem cells, are prominent amongst these endeavors and are reviewed in this article. Whilst there are many published claims to success in converting ES cells into insulin secreting, glucose responsive cells, all require careful reinterpretation in the light of findings that cells can adsorb insulin present in growth media. It is likely that work with adult cells is less prone to this potential artifact and significant progress has been made in producing insulin-secreting cells. Assessment of in vivo function in the surrogate cells is most frequently made using cell transplantation into toxin-induced, diabetic mice, but this model is rarely used to maximal advantage. In many cases, it remains unclear whether reductions in the hyperglycemia result from insulin secretion from the transplanted cells or are due to recovery of endogenous islet function. In this latter context, experiments are reviewed where endogenous stimulation of recovery is engendered even by irradiated donor cells.

  9. Cell culture purity issues and DFAT cells

    SciTech Connect

    Wei, Shengjuan; Bergen, Werner G.; Zan, Linsen; Dodson, Michael V.

    2013-04-12

    Highlights: •DFAT cells are progeny cells derived from dedifferentiated mature adipocytes. •Common problems in this research is potential cell contamination of initial cultures. •The initial cell culture purity is crucial in DFAT cell research field. -- Abstract: Dedifferentiation of mature adipocytes, in vitro, has been pursued/documented for over forty years. The subsequent progeny cells are named dedifferentiated adipocyte-derived progeny cells (DFAT cells). DFAT cells are proliferative and likely to possess mutilineage potential. As a consequence, DFAT cells and their progeny/daughter cells may be useful as a potential tool for various aspects of tissue engineering and as potential vectors for the alleviation of several disease states. Publications in this area have been increasing annually, but the purity of the initial culture of mature adipocytes has seldom been documented. Consequently, it is not always clear whether DFAT cells are derived from dedifferentiated mature (lipid filled) adipocytes or from contaminating cells that reside in an impure culture.

  10. Processing, physico-chemical, sensory and nutritional evaluation of protein, mineral and vitamin enriched peanut chikki - an Indian traditional sweet.

    PubMed

    Pallavi, Byrappa Vasu; Chetana, Ramakrishna; Reddy, Sunkireddy Yella

    2014-01-01

    Chikki, a popular Indian traditional sweet snack prepared from peanut was enriched with protein, minerals and vitamins by incorporating soy protein isolate, calcium carbonate, ferrous fumerate, vitamin A and folic acid to meet the growing demand for health foods. The enriched nutra chikki was evaluated for physico-chemical characteristics such as moisture, texture, peroxide value (PV), fatty acid composition in comparison with control peanut chikki. Nutra chikki, which had initial moisture content of 2-3%, did not alter much up to 60 days of storage at 27 °C and 37 °C. PV increased gradually at 27 °C, whereas at 37 °C, it was higher. Hardness of nutra chikki did not change significantly when stored at 27 °C up to 105 days, but at 37 °C a gradual increase in hardness was observed after 45 days. These results of nutra chikki were similar and comparable with those of control chikki. Nutra chikki had 18% protein, 20% fat, 6.42% Ca, 1.7% Fe, 4000 μg vitamin A and 2660 μg folic acid. Protein digestibility corrected amino acid score of nutra chikki was 0.78 whereas that of control chikki was 0.73. The fatty acid composition of control and nutra chikki was same as both contain peanuts as oil source. The formulation and process parameters for preparation of protein, mineral and vitamin enriched peanut chikki, were standardized. The storage stability and quality parameters of enriched chikki were comparable with those of control chikki.

  11. Electrochemical cell

    SciTech Connect

    Heuts, J.J.F.; Frens, G.

    1987-10-27

    An electrochemical cell is described comprising a negative electrode. The electrochemically active material consists of an intermetallic compound forming a hydride with hydrogen, which compound has the CaCu/sub 5/-structure and the compositional formula AB/sub m/C/sub n/, where m+n is between 4.8 and 5.4, and where n is between 0.05 and 0.6. A consists of Mischmetall or of at least one element selected from the group consisting of Y, Ti, Hf, Zr, Ca, Th, La and the remaining rare earth metals, in which the total atomic quantities of the elements Y, Ti, Hf and Zr may not be more than 40% of A. B consists of two or more elements selected from the group consisting of Ni, Co, Cu, Fe and Mn, the maximum atomic quantity per gram atom of A is being for Ni:3.5, for Co:3.5, for Cu:3.5, for Fe:2.0 and for Mn:1.0. C consists of at least one element selected from the group consisting of Al, Cr and Si in the following atomic quantities: Al:0.05-0.6, Cr:0.05-0.5 and Si:0.05-0.5, characterized in that the electrochemically active material of the negative electrode also comprises an intermetallic compound forming a hydride with hydrogen, of the compositional formula DNihd pE/sub q/ in an amount from 5 to 45% by weight calculated on the total amount of electrochemically active material, where p+q is between 4.8 and 5.4, where p is between 3.5 and 5.4, where q has a value from 0 to 1.5. D is selected from the group formed by La and Mischmetall, and E consists of one or more elements selected from the group consisting of Co, Cr, Mn and Cu.

  12. Fuel cell-fuel cell hybrid system

    DOEpatents

    Geisbrecht, Rodney A.; Williams, Mark C.

    2003-09-23

    A device for converting chemical energy to electricity is provided, the device comprising a high temperature fuel cell with the ability for partially oxidizing and completely reforming fuel, and a low temperature fuel cell juxtaposed to said high temperature fuel cell so as to utilize remaining reformed fuel from the high temperature fuel cell. Also provided is a method for producing electricity comprising directing fuel to a first fuel cell, completely oxidizing a first portion of the fuel and partially oxidizing a second portion of the fuel, directing the second fuel portion to a second fuel cell, allowing the first fuel cell to utilize the first portion of the fuel to produce electricity; and allowing the second fuel cell to utilize the second portion of the fuel to produce electricity.

  13. Red blood cells, sickle cell (image)

    MedlinePlus

    ... is an inherited blood disease in which the red blood cells produce abnormal pigment (hemoglobin). The abnormal hemoglobin causes deformity of the red blood cells into crescent or sickle-shapes, as seen in ...

  14. Cell culture purity issues and DFAT cells.

    PubMed

    Wei, Shengjuan; Bergen, Werner G; Hausman, Gary J; Zan, Linsen; Dodson, Michael V

    2013-04-12

    Dedifferentiation of mature adipocytes, in vitro, has been pursued/documented for over forty years. The subsequent progeny cells are named dedifferentiated adipocyte-derived progeny cells (DFAT cells). DFAT cells are proliferative and likely to possess mutilineage potential. As a consequence, DFAT cells and their progeny/daughter cells may be useful as a potential tool for various aspects of tissue engineering and as potential vectors for the alleviation of several disease states. Publications in this area have been increasing annually, but the purity of the initial culture of mature adipocytes has seldom been documented. Consequently, it is not always clear whether DFAT cells are derived from dedifferentiated mature (lipid filled) adipocytes or from contaminating cells that reside in an impure culture.

  15. Mammary stem cells have myoepithelial cell properties

    PubMed Central

    Prater, Michael D.; Petit, Valérie; Russell, I. Alasdair; Giraddi, Rajshekhar; Shehata, Mona; Menon, Suraj; Schulte, Reiner; Kalajzic, Ivo; Rath, Nicola; Olson, Michael F.; Metzger, Daniel; Faraldo, Marisa M.; Deugnier, Marie-Ange; Glukhova, Marina A.; Stingl, John

    2014-01-01

    Contractile myoepithelial cells dominate the basal layer of the mammary epithelium and are considered to be differentiated cells. However, we observe that up to 54% of single basal cells can form colonies when seeded into adherent culture in the presence of agents that disrupt acin-myosin interactions, and on average, 65% of the single-cell-derived basal colonies can repopulate a mammary gland when transplanted in vivo. This indicates that a high proportion of basal myoepithelial cells can give rise to a mammary repopulating unit (MRU). We demonstrate that myoepithelial cells, flow-sorted using 2 independent myoepithelial-specific reporter strategies, have MRU capacity. Using an inducible lineage tracing approach we follow the progeny of α-smooth muscle actin-expressing myoepithelial cells and show that they function as long-lived lineage-restricted stem cells in the virgin state and during pregnancy. PMID:25173976

  16. Cell Membrane Softening in Cancer Cells

    NASA Astrophysics Data System (ADS)

    Schmidt, Sebastian; Händel, Chris; Käs, Josef

    Biomechanical properties are useful characteristics and regulators of the cell's state. Current research connects mechanical properties of the cytoskeleton to many cellular processes but does not investigate the biomechanics of the plasma membrane. We evaluated thermal fluctuations of giant plasma membrane vesicles, directly derived from the plasma membranes of primary breast and cervical cells and observed a lowered rigidity in the plasma membrane of malignant cells compared to non-malignant cells. To investigate the specific role of membrane rigidity changes, we treated two cell lines with the Acetyl-CoA carboxylase inhibitor Soraphen A. It changed the lipidome of cells and drastically increased membrane stiffness by up regulating short chained membrane lipids. These altered cells had a decreased motility in Boyden chamber assays. Our results indicate that the thermal fluctuations of the membrane, which are much smaller than the fluctuations driven by the cytoskeleton, can be modulated by the cell and have an impact on adhesion and motility.

  17. Beta Cell Breakthroughs

    MedlinePlus

    ... says Douglas Melton, PhD, a biologist at the Harvard Stem Cell Institute. Fluctuating blood glucose levels do ... journal Cell, Melton reported that his team at Harvard managed to turn human stem cells into beta ...

  18. Sickle cell test

    MedlinePlus

    The sickle cell test looks for the abnormal hemoglobin in the blood that causes the disease sickle ... done to tell if a person has abnormal hemoglobin that causes sickle cell disease and sickle cell ...

  19. [Pancreatic cancer stem cell].

    PubMed

    Hamada, Shin; Masamune, Atsushi; Shimosegawa, Tooru

    2015-05-01

    Prognosis of pancreatic cancer remains dismal due to the resistance against conventional therapies. Metastasis and massive invasion toward surrounding organs hamper radical resection. Small part of entire cancer cells reveal resistance against chemotherapy or radiotherapy, increased tumorigenicity and migratory phenotype. These cells are called as cancer stem cells, as a counter part of normal stem cells. In pancreatic cancer, several cancer stem cell markers have been identified, which enabled detailed characterization of pancreatic cancer stem cells. Recent researches clarified that conventional chemotherapy itself could increase cancer cells with stem cell-phenotype, suggesting the necessity of cancer stem cell-targeting therapy. Based on these observations, pancreatic cancer stem cell-targeting therapies have been tested, which effectively eliminated cancer stem cell fraction and attenuated cancer progression in experimental models. Clinical efficacy of these therapies need to be evaluated, and cancer stem cell-targeting therapy will contribute to improve the prognosis of pancreatic cancer.

  20. Closed Large Cell Clouds

    Atmospheric Science Data Center

    2013-04-19

    article title:  Closed Large Cell Clouds in the South Pacific     ... unperturbed by cyclonic or frontal activity. When the cell centers are cloudy and the main sinking motion is concentrated at cell ...

  1. Liver cancer stem cells.

    PubMed

    Sell, Stewart; Leffert, Hyam L

    2008-06-10

    In an effort to review the evidence that liver cancer stem cells exist, two fundamental questions must be addressed. First, do hepatocellular carcinomas (HCC) arise from liver stem cells? Second, do HCCs contain cells that possess properties of cancer stem cells? For many years the finding of preneoplastic nodules in the liver during experimental induction of HCCs by chemicals was interpreted to support the hypothesis that HCC arose by dedifferentiation of mature liver cells. More recently, recognition of the role of small oval cells in the carcinogenic process led to a new hypothesis that HCC arises by maturation arrest of liver stem cells. Analysis of the cells in HCC supports the presence of cells with stem-cell properties (ie, immortality, transplantability, and resistance to therapy). However, definitive markers for these putative cancer stem cells have not yet been found and a liver cancer stem cell has not been isolated.

  2. Inside the Cell

    MedlinePlus

    ... Business Basics Describes functions shared by virtually all cells: making fuel and proteins, transporting materials and disposing of wastes. » more Chapter 3: On the Job: Cellular Specialties Explains how cells specialize. Features a number of cell types: nerves, ...

  3. Sickle cell anemia - resources

    MedlinePlus

    Resources - sickle cell anemia ... The following organizations are good resources for information on sickle cell anemia : American Sickle Cell Anemia Association -- www.ascaa.org National Heart, Blood, and Lung Institute -- www. ...

  4. Lung cancer - small cell

    MedlinePlus

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC are ...

  5. Fuel cells: A survey

    NASA Technical Reports Server (NTRS)

    Crowe, B. J.

    1973-01-01

    A survey of fuel cell technology and applications is presented. The operating principles, performance capabilities, and limitations of fuel cells are discussed. Diagrams of fuel cell construction and operating characteristics are provided. Photographs of typical installations are included.

  6. Advances in cell culture

    SciTech Connect

    Maramorosch, K. )

    1987-01-01

    This book presents papers on advances in cell culture. Topics covered include: Genetic changes in the influenza viruses during growth in cultured cells; The biochemistry and genetics of mosquito cells in culture; and Tree tissue culture applications.

  7. Kidney cell electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P.

    1979-01-01

    A kidney cell electrophoresis technique is described in four parts: (1) the development and testing of electrophoresis solutions; (2) optimization of freezing and thawing; (3) procedures for evaluation of separated kidney cells; and (4) electrophoretic mobility characteristics of kidney cells.

  8. Kidney cell electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P.

    1980-01-01

    The following aspects of kidney cell electrophoresis are discussed: (1) the development and testing of electrophoresis solutions; (2) optimization of freezing and thawing; (3) procedures for evaluation of separated kidney cells; and (4) electrophoretic mobility characterization of kidney cells.

  9. CellFinder: a cell data repository.

    PubMed

    Stachelscheid, Harald; Seltmann, Stefanie; Lekschas, Fritz; Fontaine, Jean-Fred; Mah, Nancy; Neves, Mariana; Andrade-Navarro, Miguel A; Leser, Ulf; Kurtz, Andreas

    2014-01-01

    CellFinder (http://www.cellfinder.org) is a comprehensive one-stop resource for molecular data characterizing mammalian cells in different tissues and in different development stages. It is built from carefully selected data sets stemming from other curated databases and the biomedical literature. To date, CellFinder describes 3394 cell types and 50 951 cell lines. The database currently contains 3055 microscopic and anatomical images, 205 whole-genome expression profiles of 194 cell/tissue types from RNA-seq and microarrays and 553 905 protein expressions for 535 cells/tissues. Text mining of a corpus of >2000 publications followed by manual curation confirmed expression information on ∼900 proteins and genes. CellFinder's data model is capable to seamlessly represent entities from single cells to the organ level, to incorporate mappings between homologous entities in different species and to describe processes of cell development and differentiation. Its ontological backbone currently consists of 204 741 ontology terms incorporated from 10 different ontologies unified under the novel CELDA ontology. CellFinder's web portal allows searching, browsing and comparing the stored data, interactive construction of developmental trees and navigating the partonomic hierarchy of cells and tissues through a unique body browser designed for life scientists and clinicians.

  10. CellFinder: a cell data repository

    PubMed Central

    Stachelscheid, Harald; Seltmann, Stefanie; Lekschas, Fritz; Fontaine, Jean-Fred; Mah, Nancy; Neves, Mariana; Andrade-Navarro, Miguel A.; Leser, Ulf; Kurtz, Andreas

    2014-01-01

    CellFinder (http://www.cellfinder.org) is a comprehensive one-stop resource for molecular data characterizing mammalian cells in different tissues and in different development stages. It is built from carefully selected data sets stemming from other curated databases and the biomedical literature. To date, CellFinder describes 3394 cell types and 50 951 cell lines. The database currently contains 3055 microscopic and anatomical images, 205 whole-genome expression profiles of 194 cell/tissue types from RNA-seq and microarrays and 553 905 protein expressions for 535 cells/tissues. Text mining of a corpus of >2000 publications followed by manual curation confirmed expression information on ∼900 proteins and genes. CellFinder’s data model is capable to seamlessly represent entities from single cells to the organ level, to incorporate mappings between homologous entities in different species and to describe processes of cell development and differentiation. Its ontological backbone currently consists of 204 741 ontology terms incorporated from 10 different ontologies unified under the novel CELDA ontology. CellFinder’s web portal allows searching, browsing and comparing the stored data, interactive construction of developmental trees and navigating the partonomic hierarchy of cells and tissues through a unique body browser designed for life scientists and clinicians. PMID:24304896

  11. Glial cells: Old cells with new twists

    PubMed Central

    Ndubaku, Ugo; de Bellard, Maria Elena

    2008-01-01

    Summary Based on their characteristics and function – migration, neural protection, proliferation, axonal guidance and trophic effects – glial cells may be regarded as probably the most versatile cells in our body. For many years, these cells were considered as simply support cells for neurons. Recently, it has been shown that they are more versatile than previously believed – as true stem cells in the nervous system – and are important players in neural function and development. There are several glial cell types in the nervous system: the two most abundant are oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. Although both of these cells are responsible for myelination, their developmental origins are quite different. Oligodendrocytes originate from small niche populations from different regions of the central nervous system, while Schwann cells develop from a stem cell population (the neural crest) that gives rise to many cell derivatives besides glia and which is a highly migratory group of cells. PMID:18068219

  12. Cell Proliferation, Cell Death, and Size Regulation

    DTIC Science & Technology

    2000-10-01

    generated in part by apoptosis of excess cells during development. We identified a mutation named pineapple eye (pie ) that has too few cells in the...predicted to encode a novel 582 amino acid protein, perhaps interacting with molybdopterin. It is possible that the pie gene encodes a novel enzyme protecting against cell death during growth and development.

  13. Snail modulates cell metabolism in MDCK cells

    SciTech Connect

    Haraguchi, Misako; Indo, Hiroko P.; Iwasaki, Yasumasa; Iwashita, Yoichiro; Fukushige, Tomoko; Majima, Hideyuki J.; Izumo, Kimiko; Horiuchi, Masahisa; Kanekura, Takuro; Furukawa, Tatsuhiko; Ozawa, Masayuki

    2013-03-22

    Highlights: ► MDCK/snail cells were more sensitive to glucose deprivation than MDCK/neo cells. ► MDCK/snail cells had decreased oxidative phosphorylation, O{sub 2} consumption and ATP content. ► TCA cycle enzyme activity, but not expression, was lower in MDCK/snail cells. ► MDCK/snail cells showed reduced PDH activity and increased PDK1 expression. ► MDCK/snail cells showed reduced expression of GLS2 and ACLY. -- Abstract: Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP{sup +}-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of

  14. Sertoli cells as biochambers

    NASA Technical Reports Server (NTRS)

    Cameron, Don F. (Inventor); Sanberg, Paul R. (Inventor); Saporta, Samuel (Inventor); Hushen, Joelle J. (Inventor)

    2004-01-01

    According to the present invention, there is provided a biological chamber system having a biochamber defined by outer walls of Sertoli cells. Also provided is a transplantation facilitator including a biochamber. A method of making biochambers by co-culturing facilitator cells and therapeutic cells and then aggregating the facilitator celes is also provided. Also provided is a method of transplanting cells by incorporating transplant cells into a biochamber and transplanting the biochamber containing the transplant cells.

  15. Stem Cell Sciences plc.

    PubMed

    Daniels, Sebnem

    2006-09-01

    Stem Cell Sciences' core objective is to develop safe and effective stem cell-based therapies for currently incurable diseases. In order to achieve this goal, Stem Cell Sciences recognizes the need for multiple technologies and a globally integrated stem cell initiative. The key challenges for the successful application of stem cells in the clinic is the need for a reproducible supply of pure, fully characterized stem cells that have been grown in suitable conditions for use in the clinic.

  16. Snail modulates cell metabolism in MDCK cells.

    PubMed

    Haraguchi, Misako; Indo, Hiroko P; Iwasaki, Yasumasa; Iwashita, Yoichiro; Fukushige, Tomoko; Majima, Hideyuki J; Izumo, Kimiko; Horiuchi, Masahisa; Kanekura, Takuro; Furukawa, Tatsuhiko; Ozawa, Masayuki

    2013-03-22

    Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of key enzymes. This results in enhanced glucose dependency and leads to cell death under low-glucose conditions. On the other hand, the reduced requirements for oxygen and nutrients from the surrounding environment, might confer the resistance to cell death induced by hypoxia and malnutrition. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Nanostructured Solar Cells

    PubMed Central

    Chen, Guanying; Ning, Zhijun; Ågren, Hans

    2016-01-01

    We are glad to announce the Special Issue “Nanostructured Solar Cells”, published in Nanomaterials. This issue consists of eight articles, two communications, and one review paper, covering major important aspects of nanostructured solar cells of varying types. From fundamental physicochemical investigations to technological advances, and from single junction solar cells (silicon solar cell, dye sensitized solar cell, quantum dots sensitized solar cell, and small molecule organic solar cell) to tandem multi-junction solar cells, all aspects are included and discussed in this issue to advance the use of nanotechnology to improve the performance of solar cells with reduced fabrication costs.

  18. Stem Cell Research

    SciTech Connect

    Verfaillie, Catherine

    2009-01-23

    We have identified a population of primitive cells in normal human post-natal bone marrow that can, at the single cell level, differentiate in many ways and also proliferate extensively. These cells can differentiate in vitro into most mesodermal cell types (for example, bone cells, and others), as well as cells into cells of the nervous system. The finding that stem cells exist in post-natal tissues with previously unknown proliferation and differentiation potential opens up the possibility of using them to treat a host of degenerative, traumatic or congenital diseases.

  19. Heterostructure solar cells

    NASA Technical Reports Server (NTRS)

    Chang, K. I.; Yeh, Y. C. M.; Iles, P. A.; Morris, R. K.

    1987-01-01

    The performance of gallium arsenide solar cells grown on Ge substrates is discussed. In some cases the substrate was thinned to reduce overall cell weight with good ruggedness. The conversion efficiency of 2 by 2 cm cells under AMO reached 17.1 percent with a cell thickness of 6 mils. The work described forms the basis for future cascade cell structures, where similar interconnecting problems between the top cell and the bottom cell must be solved. Applications of the GaAs/Ge solar cell in space and the expected payoffs are discussed.

  20. Gaucher cell, photomicrograph (image)

    MedlinePlus

    Gaucher disease is called a "lipid storage disease" where abnormal amounts of lipids called "glycosphingolipids" are stored in special cells called reticuloendothelial cells. Classically, the nucleus is ...

  1. Human memory B cells.

    PubMed

    Seifert, M; Küppers, R

    2016-12-01

    A key feature of the adaptive immune system is the generation of memory B and T cells and long-lived plasma cells, providing protective immunity against recurring infectious agents. Memory B cells are generated in germinal center (GC) reactions in the course of T cell-dependent immune responses and are distinguished from naive B cells by an increased lifespan, faster and stronger response to stimulation and expression of somatically mutated and affinity matured immunoglobulin (Ig) genes. Approximately 40% of human B cells in adults are memory B cells, and several subsets were identified. Besides IgG(+) and IgA(+) memory B cells, ∼50% of peripheral blood memory B cells express IgM with or without IgD. Further smaller subpopulations have additionally been described. These various subsets share typical memory B cell features, but likely also fulfill distinct functions. IgM memory B cells appear to have the propensity for refined adaptation upon restimulation in additional GC reactions, whereas reactivated IgG B cells rather differentiate directly into plasma cells. The human memory B-cell pool is characterized by (sometimes amazingly large) clonal expansions, often showing extensive intraclonal IgV gene diversity. Moreover, memory B-cell clones are frequently composed of members of various subsets, showing that from a single GC B-cell clone a variety of memory B cells with distinct functions is generated. Thus, the human memory B-cell compartment is highly diverse and flexible. Several B-cell malignancies display features suggesting a derivation from memory B cells. This includes a subset of chronic lymphocytic leukemia, hairy cell leukemia and marginal zone lymphomas. The exposure of memory B cells to oncogenic events during their generation in the GC, the longevity of these B cells and the ease to activate them may be key determinants for their malignant transformation.

  2. The plastic liver: differentiated cells, stem cells, every cell?

    PubMed Central

    Hindley, Christopher J.; Mastrogiovanni, Gianmarco; Huch, Meritxell

    2014-01-01

    The liver is capable of full regeneration following several types and rounds of injury, ranging from hepatectomy to toxin-mediated damage. The source of this regenerative capacity has long been a hotly debated topic. The damage response that occurs when hepatocyte proliferation is impaired is thought to be mediated by oval/dedifferentiated progenitor cells, which replenish the hepatocyte and ductal compartments of the liver. Recently, reports have questioned whether these oval/progenitor cells truly serve as the facultative stem cell of the liver following toxin-mediated damage. In this issue of the JCI, Kordes and colleagues use lineage tracing to follow transplanted rat hepatic stellate cells, a resident liver mesenchymal cell population, in hosts that have suffered liver damage. Transplanted stellate cells repopulated the damaged rat liver by contributing to the oval cell response. These data establish yet another cell type of mesenchymal origin as the progenitor for the oval/ductular response in the rat. The lack of uniformity between different damage models, the extent of the injury to the liver parenchyma, and potential species-specific differences might be at the core of the discrepancy between different studies. Taken together, these data imply a considerable degree of plasticity in the liver, whereby several cell types can contribute to regeneration. PMID:25401467

  3. Accessory cells for β-cell transplantation.

    PubMed

    Staels, W; De Groef, S; Heremans, Y; Coppens, V; Van Gassen, N; Leuckx, G; Van de Casteele, M; Van Riet, I; Luttun, A; Heimberg, H; De Leu, N

    2016-02-01

    Despite recent advances, insulin therapy remains a treatment, not a cure, for diabetes mellitus with persistent risk of glycaemic alterations and life-threatening complications. Restoration of the endogenous β-cell mass through regeneration or transplantation offers an attractive alternative. Unfortunately, signals that drive β-cell regeneration remain enigmatic and β-cell replacement therapy still faces major hurdles that prevent its widespread application. Co-transplantation of accessory non-islet cells with islet cells has been shown to improve the outcome of experimental islet transplantation. This review will highlight current travails in β-cell therapy and focuses on the potential benefits of accessory cells for islet transplantation in diabetes.

  4. [Exosomes and Immune Cells].

    PubMed

    Seo, Naohiro

    2017-05-01

    In addition to the cytokines and cytotoxic granules, exosomes have been known as the intercellular communicator and cytotoxic missile of immune cells for the past decade. It has been well known that mature dendritic cell(DC)-derived exosomes participate in the T cell and natural killer(NK)cell activation, while immature DCs secrete tolerogenic exosomes for regulatory T(Treg)cell generation. Treg cell-derived EVs act as a suppressor against pathogenic type-1 T helper(Th1)cell responses. CD8+ T cells produce tumoricidal exosomes for preventing tumor invasion and metastasis transiently after T cell receptor(TCR)-mediated stimulation. Thus, immune cells produce functional exosomes in the activation state- and/or differentiation stage-dependent manner. In this review, the role of immune cell-derived exosomes will be introduced, focusing mainly on immune reaction against tumor.

  5. Cell mechanics: a dialogue

    NASA Astrophysics Data System (ADS)

    Tao, Jiaxiang; Li, Yizeng; Vig, Dhruv K.; Sun, Sean X.

    2017-03-01

    Under the microscope, eukaryotic animal cells can adopt a variety of different shapes and sizes. These cells also move and deform, and the physical mechanisms driving these movements and shape changes are important in fundamental cell biology, tissue mechanics, as well as disease biology. This article reviews some of the basic mechanical concepts in cells, emphasizing continuum mechanics description of cytoskeletal networks and hydrodynamic flows across the cell membrane. We discuss how cells can generate movement and shape changes by controlling mass fluxes at the cell boundary. These mass fluxes can come from polymerization/depolymerization of actin cytoskeleton, as well as osmotic and hydraulic pressure-driven flow of water across the cell membrane. By combining hydraulic pressure control with force balance conditions at the cell surface, we discuss a quantitative mechanism of cell shape and volume control. The broad consequences of this model on cell mechanosensation and tissue mechanics are outlined.

  6. Cell mechanics: a dialogue.

    PubMed

    Tao, Jiaxiang; Li, Yizeng; Vig, Dhruv K; Sun, Sean X

    2017-03-01

    Under the microscope, eukaryotic animal cells can adopt a variety of different shapes and sizes. These cells also move and deform, and the physical mechanisms driving these movements and shape changes are important in fundamental cell biology, tissue mechanics, as well as disease biology. This article reviews some of the basic mechanical concepts in cells, emphasizing continuum mechanics description of cytoskeletal networks and hydrodynamic flows across the cell membrane. We discuss how cells can generate movement and shape changes by controlling mass fluxes at the cell boundary. These mass fluxes can come from polymerization/depolymerization of actin cytoskeleton, as well as osmotic and hydraulic pressure-driven flow of water across the cell membrane. By combining hydraulic pressure control with force balance conditions at the cell surface, we discuss a quantitative mechanism of cell shape and volume control. The broad consequences of this model on cell mechanosensation and tissue mechanics are outlined.

  7. Cell mechanics: a dialogue

    PubMed Central

    Tao, Jiaxiang; Li, Yizeng; Vig, Dhruv K; Sun, Sean X

    2017-01-01

    Under the microscope, eukaryotic animal cells can adopt a variety of different shapes and sizes. These cells also move and deform, and the physical mechanisms driving these movements and shape changes are important in fundamental cell biology, tissue mechanics, as well as disease biology. This article reviews some of the basic mechanical concepts in cells, emphasizing continuum mechanics description of cytoskeletal networks and hydrodynamic flows across the cell membrane. We discuss how cells can generate movement and shape changes by controlling mass fluxes at the cell boundary. These mass fluxes can come from polymerization/depolymerization of actin cytoskeleton, as well as osmotic and hydraulic pressure-driven flow of water across the cell membrane. By combining hydraulic pressure control with force balance conditions at the cell surface, we discuss a quantitative mechanism of cell shape and volume control. The broad consequences of this model on cell mechanosensation and tissue mechanics are outlined. PMID:28129208

  8. Cell surface engineering of mesenchymal stem cells.

    PubMed

    Sarkar, Debanjan; Zhao, Weian; Gupta, Ashish; Loh, Wei Li; Karnik, Rohit; Karp, Jeffrey M

    2011-01-01

    By leveraging the capacity to promote regeneration, stem cell therapies offer enormous hope for solving some of the most tragic illnesses, diseases, and tissue defects world-wide. However, a significant barrier to the effective implementation of cell therapies is the inability to target a large quantity of viable cells with high efficiency to tissues of interest. Systemic infusion is desired as it minimizes the invasiveness of cell therapy, and maximizes practical aspects of repeated doses. However, cell types such as mesenchymal stem cells exhibit a poor homing capability or lose their capacity to home following culture expansion (i.e. FASEB J 21:3197-3207, 2007; Circulation 108:863-868, 2003; Stroke: A Journal of Cerebral Circulation 32:1005-1011; Blood 104:3581-3587, 2004). To address this challenge, we have developed a simple platform technology to chemically attach cell adhesion molecules to the cell surface to improve the homing efficiency to specific tissues. This chemical approach involves a stepwise process including (1) treatment of cells with sulfonated biotinyl-N-hydroxy-succinimide to introduce biotin groups on the cell surface, (2) addition of streptavidin that binds to the biotin on the cell surface and presents unoccupied binding sites, and (3) attachment of biotinylated targeting ligands that promote adhesive interactions with vascular endothelium. Specifically, in our model system, a biotinylated cell rolling ligand, sialyl Lewisx (SLeX), found on the surface of leukocytes (i.e., the active site of the P-selectin glycoprotein ligand (PSGL-1)), is conjugated on MSC surface. The SLeX engineered MSCs exhibit a rolling response on a P-selectin coated substrate under shear stress conditions. This indicates that this approach can be used to potentially target P-selectin expressing endothelium in the more marrow or at sites of inflammation. Importantly, the surface modification has no adverse impact on MSCs' native phenotype including their multilineage

  9. Resident vascular progenitor cells.

    PubMed

    Torsney, Evelyn; Xu, Qingbo

    2011-02-01

    Homeostasis of the vessel wall is essential for maintaining its function, including blood pressure and patency of the lumen. In physiological conditions, the turnover rate of vascular cells, i.e. endothelial and smooth muscle cells, is low, but markedly increased in diseased situations, e.g. vascular injury after angioplasty. It is believed that mature vascular cells have an ability to proliferate to replace lost cells normally. On the other hand, recent evidence indicates stem/progenitor cells may participate in vascular repair and the formation of neointimal lesions in severely damaged vessels. It was found that all three layers of the vessels, the intima, media and adventitia, contain resident progenitor cells, including endothelial progenitor cells, mesenchymal stromal cells, Sca-1+ and CD34+ cells. Data also demonstrated that these resident progenitor cells could differentiate into a variety of cell types in response to different culture conditions. However, collective data were obtained mostly from in vitro culture assays and phenotypic marker studies. There are many unanswered questions concerning the mechanism of cell differentiation and the functional role of these cells in vascular repair and the pathogenesis of vascular disease. In the present review, we aim to summarize the data showing the presence of the resident progenitor cells, to highlight possible signal pathways orchestrating cell differentiation toward endothelial and smooth muscle cells, and to discuss the data limitations, challenges and controversial issues related to the role of progenitors. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited".

  10. Cancer stem cell-like cells from a single cell of oral squamous carcinoma cell lines

    SciTech Connect

    Felthaus, O.; Ettl, T.; Gosau, M.; Driemel, O.; Brockhoff, G.; Reck, A.; Zeitler, K.; Hautmann, M.; Reichert, T.E.; Schmalz, G.; Morsczeck, C.

    2011-04-01

    Research highlights: {yields} Four oral squamous cancer cell lines (OSCCL) were analyzed for cancer stem cells (CSCs). {yields} Single cell derived colonies of OSCCL express CSC-marker CD133 differentially. {yields} Monoclonal cell lines showed reduced sensitivity for Paclitaxel. {yields} In situ CD133{sup +} cells are slow cycling (Ki67-) indicating a reduced drug sensitivity. {yields} CD133{sup +} and CSC-like cells can be obtained from single colony forming cells of OSCCL. -- Abstract: Resistance of oral squamous cell carcinomas (OSCC) to conventional chemotherapy or radiation therapy might be due to cancer stem cells (CSCs). The development of novel anticancer drugs requires a simple method for the enrichment of CSCs. CSCs can be enriched from OSCC cell lines, for example, after cultivation in serum-free cell culture medium (SFM). In our study, we analyzed four OSCC cell lines for the presence of CSCs. CSC-like cells could not be enriched with SFM. However, cell lines obtained from holoclone colonies showed CSC-like properties such as a reduced rate of cell proliferation and a reduced sensitivity to Paclitaxel in comparison to cells from the parental lineage. Moreover, these cell lines differentially expressed the CSC-marker CD133, which is also upregulated in OSCC tissues. Interestingly, CD133{sup +} cells in OSCC tissues expressed little to no Ki67, the cell proliferation marker that also indicates reduced drug sensitivity. Our study shows a method for the isolation of CSC-like cell lines from OSCC cell lines. These CSC-like cell lines could be new targets for the development of anticancer drugs under in vitro conditions.

  11. Stem cell therapy without the cells

    PubMed Central

    Maguire, Greg

    2013-01-01

    As an example of the burgeoning importance of stem cell therapy, this past month the California Institute for Regenerative Medicine (CIRM) has approved $70 million to create a new network of stem cell clinical trial centers. Much work in the last decade has been devoted to developing the use of autologous and allogeneic adult stem cell transplants to treat a number of conditions, including heart attack, dementia, wounds, and immune system-related diseases. The standard model teaches us that adult stem cells exists throughout most of the body and provide a means to regenerate and repair most tissues through replication and differentiation. Although we have often witnessed the medical cart placed in front of the scientific horse in the development of stem cell therapies outside of academic circles, great strides have been made, such as the use of purified stem cells1 instead of whole bone marrow transplants in cancer patients, where physicians avoid re-injecting the patients with their own cancer cells.2 We most often think of stem cell therapy acting to regenerate tissue through replication and then differentiation, but recent studies point to the dramatic effects adult stem cells exert in the repair of various tissues through the release of paracrine and autocrine substances, and not simply through differentiation. Indeed, up to 80% of the therapeutic effect of adult stem cells has been shown to be through paracrine mediated actions.3 That is, the collected types of molecules released by the stem cells, called the secretome, or stem cell released molecules (SRM), number in the 100s, including proteins, microRNA, growth factors, antioxidants, proteasomes, and exosomes, and target a multitude of biological pathways through paracrine actions. The composition of the different molecule types in SRM is state dependent, and varies with cell type and conditions such as age and environment. PMID:24567776

  12. Dummy Cell Would Improve Performance Of Fuel-Cell Stack

    NASA Technical Reports Server (NTRS)

    Suljak, G. T.

    1993-01-01

    Interposition of dummy cell between stack of alkaline fuel cells and accessory section of fuel-cell powerplant proposed to overcome operational deficiencies plaguing end-most active cell. Cell in combination with additional hydrogen/coolant separator plate keeps end cell warmer and drier. End cell 96th in stack of fuel cells.

  13. Specific cell cycle synchronization with butyrate and cell cycle analysis

    USDA-ARS?s Scientific Manuscript database

    Synchronized cells have been invaluable for many kinds of cell cycle and cell proliferation studies. Butyrate induces cell cycle arrest and apoptosis in MDBK cells. To explore the possibility of using butyrate-blocked cells to obtain synchronized cells, we investigated the property of the cell cyc...

  14. Dummy Cell Would Improve Performance Of Fuel-Cell Stack

    NASA Technical Reports Server (NTRS)

    Suljak, G. T.

    1993-01-01

    Interposition of dummy cell between stack of alkaline fuel cells and accessory section of fuel-cell powerplant proposed to overcome operational deficiencies plaguing end-most active cell. Cell in combination with additional hydrogen/coolant separator plate keeps end cell warmer and drier. End cell 96th in stack of fuel cells.

  15. Nanocomposite Photoelectrochemical Cells

    NASA Technical Reports Server (NTRS)

    Narayan, Sri R.; Kindler, Andrew; Whitacre, Jay F.

    2007-01-01

    Improved, solid-state photoelectrochemical cells for converting solar radiation to electricity have been proposed. (In general, photoelectrochemical cells convert incident light to electricity through electrochemical reactions.) It is predicted that in comparison with state-of-the-art photoelectrochemical cells, these cells will be found to operate with greater solar-to-electric energy-conversion efficiencies.

  16. Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

    SciTech Connect

    Varga, Nora; Vereb, Zoltan; Rajnavoelgyi, Eva; Nemet, Katalin; Uher, Ferenc; Sarkadi, Balazs; Apati, Agota

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer MSC like cells were derived from hESC by a simple and reproducible method. Black-Right-Pointing-Pointer Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. Black-Right-Pointing-Pointer MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth of undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.

  17. Chromosomal differentiation of cells

    SciTech Connect

    1993-12-31

    Chapter 16, discusses the chromosomal differentiation of cells. The chromosomes of differentiated cells have been much less studies than those of meristematic or germline cells, probably because such cells do not usually divide spontaneously. However, in many cases they can be induced to undergo mitosis. 26 refs., 2 figs.

  18. Dictyostelium cell death

    PubMed Central

    Levraud, Jean-Pierre; Adam, Myriam; Luciani, Marie-Françoise; de Chastellier, Chantal; Blanton, Richard L.; Golstein, Pierre

    2003-01-01

    Cell death in the stalk of Dictyostelium discoideum, a prototypic vacuolar cell death, can be studied in vitro using cells differentiating as a monolayer. To identify early events, we examined potentially dying cells at a time when the classical signs of Dictyostelium cell death, such as heavy vacuolization and membrane lesions, were not yet apparent. We observed that most cells proceeded through a stereotyped series of differentiation stages, including the emergence of “paddle” cells showing high motility and strikingly marked subcellular compartmentalization with actin segregation. Paddle cell emergence and subsequent demise with paddle-to-round cell transition may be critical to the cell death process, as they were contemporary with irreversibility assessed through time-lapse videos and clonogenicity tests. Paddle cell demise was not related to formation of the cellulose shell because cells where the cellulose-synthase gene had been inactivated underwent death indistinguishable from that of parental cells. A major subcellular alteration at the paddle-to-round cell transition was the disappearance of F-actin. The Dictyostelium vacuolar cell death pathway thus does not require cellulose synthesis and includes early actin rearrangements (F-actin segregation, then depolymerization), contemporary with irreversibility, corresponding to the emergence and demise of highly polarized paddle cells. PMID:12654899

  19. Molten carbonate fuel cell

    DOEpatents

    Kaun, Thomas D.; Smith, James L.

    1987-01-01

    A molten electrolyte fuel cell with an array of stacked cells and cell enclosures isolating each cell except for access to gas manifolds for the supply of fuel or oxidant gas or the removal of waste gas, the cell enclosures collectively providing an enclosure for the array and effectively avoiding the problems of electrolyte migration and the previous need for compression of stack components, the fuel cell further including an inner housing about and in cooperation with the array enclosure to provide a manifold system with isolated chambers for the supply and removal of gases. An external insulated housing about the inner housing provides thermal isolation to the cell components.

  20. Individual cell sorting.

    PubMed

    Stovel, R T; Sweet, R G

    1979-01-01

    Current cell sorting machines do not preserve the individual identity of processed cells; after analysis, the cells are assigned to a subpopulation where they are pooled with other similar cells. This paper reports progress on a system that sorts cells individually to precise locations on a microscope slide and preserves them for further observation with a light microscope while recording flow measurement data for each cell. Various electronic and mechanical modifications to an existing sorting machine are described that increase drop placement accuracy and permit individual cell sorting.

  1. Stem Cell Organoid Engineering

    PubMed Central

    Yin, Xiaolei; Mead, Benjamin E.; Safaee, Helia; Langer, Robert; Karp, Jeffrey M.; Levy, Oren

    2016-01-01

    Organoid systems leverage the self-organizing properties of stem cells to create diverse multi-cellular tissue proxies. Most organoid models only represent single or partial components of a tissue, and it is often difficult to control the cell type, organization, and cell-cell/cell-matrix interactions within these systems. Herein, we discuss basic approaches to generate stem cell-based organoids, their advantages and limitations, and how bioengineering strategies can be used to steer the cell composition and their 3D organization within organoids to further enhance their utility in research and therapies. PMID:26748754

  2. Cytokinesis in animal cells.

    PubMed

    D'Avino, Pier Paolo; Giansanti, Maria Grazia; Petronczki, Mark

    2015-02-13

    Cell division ends with the physical separation of the two daughter cells, a process known as cytokinesis. This final event ensures that nuclear and cytoplasmic contents are accurately partitioned between the two nascent cells. Cytokinesis is one of the most dramatic changes in cell shape and requires an extensive reorganization of the cell's cytoskeleton. Here, we describe the cytoskeletal structures, factors, and signaling pathways that orchestrate this robust and yet highly dynamic process in animal cells. Finally, we discuss possible future directions in this growing area of cell division research and its implications in human diseases, including cancer.

  3. Cell tracking using nanoparticles.

    PubMed

    Vaccaro, Dennis E; Yang, Meiheng; Weinberg, James S; Reinhardt, Christopher P; Groman, Ernest V

    2008-09-01

    Tracking cells in regenerative medicine is becoming increasingly important for basic cell therapy science, for cell delivery optimization and for accurate biodistribution studies. This report describes nanoparticles that utilize stable-isotope metal labels for multiple detection technologies in preclinical studies. Cells labeled with nanoparticles can be imaged by electron microscopy, fluorescence, and magnetic resonance. The nanoparticle-labeled cells can be quantified by neutron activation, thereby allowing, with the use of standard curves, the determination of the number of labeled cells in tissue samples from in vivo sources. This report describes the characteristics of these nanoparticles and methods for using these nanoparticles to label and track cells.

  4. Fluorescence activated cell sorting.

    NASA Technical Reports Server (NTRS)

    Bonner, W. A.; Hulett, H. R.; Sweet, R. G.; Herzenberg, L. A.

    1972-01-01

    An instrument has been developed for sorting biological cells. The cells are rendered differentially fluorescent and incorporated into a small liquid stream illuminated by a laser beam. The cells pass sequentially through the beam, and fluorescent light from the cells gives rise to electrical signals. The stream is broken into a series of uniform size drops downstream of the laser. The cell signals are used to give appropriate electrostatic charges to drops containing the cells. The drops then pass between two charged plates and are deflected to appropriate containers. The system has proved capable of providing fractions containing large numbers of viable cells highly enriched in a particular functional type.

  5. Molten carbonate fuel cell

    DOEpatents

    Kaun, T.D.; Smith, J.L.

    1986-07-08

    A molten electrolyte fuel cell is disclosed with an array of stacked cells and cell enclosures isolating each cell except for access to gas manifolds for the supply of fuel or oxidant gas or the removal of waste gas. The cell enclosures collectively provide an enclosure for the array and effectively avoid the problems of electrolyte migration and the previous need for compression of stack components. The fuel cell further includes an inner housing about and in cooperation with the array enclosure to provide a manifold system with isolated chambers for the supply and removal of gases. An external insulated housing about the inner housing provides thermal isolation to the cell components.

  6. Engineering Stem Cell Organoids.

    PubMed

    Yin, Xiaolei; Mead, Benjamin E; Safaee, Helia; Langer, Robert; Karp, Jeffrey M; Levy, Oren

    2016-01-07

    Organoid systems leverage the self-organizing properties of stem cells to create diverse multi-cellular tissue proxies. Most organoid models only represent single or partial components of a tissue, and it is often difficult to control the cell type, organization, and cell-cell/cell-matrix interactions within these systems. Herein, we discuss basic approaches to generate stem cell-based organoids, their advantages and limitations, and how bioengineering strategies can be used to steer the cell composition and their 3D organization within organoids to further enhance their utility in research and therapies.

  7. Fuel cells seminar

    SciTech Connect

    1996-12-01

    This year`s meeting highlights the fact that fuel cells for both stationary and transportation applications have reached the dawn of commercialization. Sales of stationary fuel cells have grown steadily over the past 2 years. Phosphoric acid fuel cell buses have been demonstrated in urban areas. Proton-exchange membrane fuel cells are on the verge of revolutionizing the transportation industry. These activities and many more are discussed during this seminar, which provides a forum for people from the international fuel cell community engaged in a wide spectrum of fuel cell activities. Discussions addressing R&D of fuel cell technologies, manufacturing and marketing of fuel cells, and experiences of fuel cell users took place through oral and poster presentations. For the first time, the seminar included commercial exhibits, further evidence that commercial fuel cell technology has arrived. A total of 205 papers is included in this volume.

  8. Modeling collective cell motility

    NASA Astrophysics Data System (ADS)

    Rappel, Wouter-Jan

    Eukaryotic cells often move in groups, a critical aspect of many biological and medical processes including wound healing, morphogenesis and cancer metastasis. Modeling can provide useful insights into the fundamental mechanisms of collective cell motility. Constructing models that incorporate the physical properties of the cells, however, is challenging. Here, I discuss our efforts to build a comprehensive cell motility model that includes cell membrane properties, cell-substrate interactions, cell polarity, and cell-cell interaction. The model will be applied to a variety of systems, including motion on micropatterned substrates and the migration of border cells in Drosophila. This work was supported by NIH Grant No. P01 GM078586 and NSF Grant No. 1068869.

  9. Chicken NK cell receptors.

    PubMed

    Straub, Christian; Neulen, Marie-Luise; Sperling, Beatrice; Windau, Katharina; Zechmann, Maria; Jansen, Christine A; Viertlboeck, Birgit C; Göbel, Thomas W

    2013-11-01

    Natural killer cells are innate immune cells that destroy virally infected or transformed cells. They recognize these altered cells by a plethora of diverse receptors and thereby differ from other lymphocytes that use clonally distributed antigen receptors. To date, several receptor families that play a role in either activating or inhibiting NK cells have been identified in mammals. In the chicken, NK cells have been functionally and morphologically defined, however, a conclusive analysis of receptors involved in NK cell mediated functions has not been available. This is partly due to the low frequencies of NK cells in blood or spleen that has hampered their intensive characterization. Here we will review recent progress regarding the diverse NK cell receptor families, with special emphasis on novel families identified in the chicken genome with potential as chicken NK cell receptors.

  10. Innate Memory T cells

    PubMed Central

    Jameson, Stephen C.; Lee, You Jeong; Hogquist, Kristin A.

    2015-01-01

    Memory T cells are usually considered to be a feature of a successful immune response against a foreign antigen, and such cells can mediate potent immunity. However, in mice, alternative pathways have been described, through which naïve T cells can acquire the characteristics and functions of memory T cells without encountering specific foreign antigen or the typical signals required for conventional T cell differentiation. Such cells reflect a response to the internal rather the external environment, and hence such cells are called innate memory T cells. In this review, we describe how innate memory subsets were identified, the signals that induce their generation and their functional properties and potential role in the normal immune response. The existence of innate memory T cells in mice raises questions about whether parallel populations exist in humans, and we discuss the evidence for such populations during human T cell development and differentiation. PMID:25727290

  11. Leukemia - B-Cell Prolymphocytic Leukemia and Hairy Cell Leukemia

    MedlinePlus

    ... and Hairy Cell Leukemia: Introduction Request Permissions Leukemia - B-cell Prolymphocytic Leukemia and Hairy Cell Leukemia: Introduction ... t k e P Types of Cancer Leukemia - B-cell Prolymphocytic Leukemia and Hairy Cell Leukemia Guide ...

  12. [Cell cycle regulation in cancer stem cells].

    PubMed

    Takeishi, Shoichiro

    2015-05-01

    In addition to the properties of self-renewal and multipotency, cancer stem cells share the characteristics of their distinct cell cycle status with somatic stem cells. Cancer stem cells (CSCs) are maintained in a quiescent state with this characteristic conferring resistance to anticancer therapies that target dividing cells. Elucidation of the mechanisms of CSC quiescence might therefore be expected to provide further insight into CSC behaviors and lead to the elimination of cancer. This review summarizes several key regulators of the cell cycle in CSCs as well as attempts to define future challenges in this field, especially from the point of view of the application of our current understandings to the clinical medicine.

  13. Space solar cell research

    NASA Technical Reports Server (NTRS)

    Flood, Dennis J.

    1989-01-01

    A brief overview is given of the scope of the NASA space solar cell research and development program. Silicon cells, gallium arsenide cells, indium phosphide cells, and superlattice solar cells are addressed, indicating the state of the art of each type in outer space and their advantages and drawbacks for use in outer space. Contrasts between efficiency in space and on earth are pointed out.

  14. Space solar cell research

    NASA Technical Reports Server (NTRS)

    Flood, Dennis J.

    1989-01-01

    A brief overview is given of the scope of the NASA space solar cell research and development program. Silicon cells, gallium arsenide cells, indium phosphide cells, and superlattice solar cells are addressed, indicating the state of the art of each type in outer space and their advantages and drawbacks for use in outer space. Contrasts between efficiency in space and on earth are pointed out.

  15. Kidney cell electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P. W.

    1985-01-01

    Tasks were undertaken in support of two objectives. They are: (1) to carry out electrophoresis experiments on cells in microgravity; and (2) assess the feasibility of using purified kidney cells from embryonic kidney cultures as a source of important cell products. Investigations were carried out in the following areas: (1) ground based electrophoresis technology; (2) cell culture technology; (3) electrophoresis of cells; (4) urokinase assay research; (5) zero-g electrophoresis; and (6) flow cytometry.

  16. Technology Status: Fuel Cells and Electrolysis Cells

    NASA Technical Reports Server (NTRS)

    Mcbryar, H.

    1978-01-01

    The status of the baselined shuttle fuel cell as well as the acid membrane fuel cell and space-oriented water electrolysis technologies are presented. The more recent advances in the alkaline fuel cell technology area are the subject of a companion paper. A preliminary plan for the focusing of these technologies towards regenerative energy storage applications in the multi-hundred kilowatt range is also discussed.

  17. B cell helper assays.

    PubMed

    Abrignani, Sergio; Tonti, Elena; Casorati, Giulia; Dellabona, Paolo

    2009-01-01

    Activation, proliferation and differentiation of naïve B lymphocytes into memory B cells and plasma cells requires engagement of the B cell receptor (BCR) coupled to T-cell help (1, 2). T cells deliver help in cognate fashion when they are activated upon recognition of specific MHC-peptide complexes presented by B cells. T cells can also deliver help in a non-cognate or bystander fashion, when they do not find specific MHC-peptide complexes on B cells and are activated by alternative mechanisms. T-cell dependent activation of B cells can be studied in vitro by experimental models called "B cell helper assays" that are based on the co-culture of B cells with activated T cells. These assays allow to decipher the molecular bases for productive T-dependent B cell responses. We show here examples of B cell helper assays in vitro, which can be reproduced with any subset of T lymphocytes that displays the appropriate helper signals.

  18. Screening of solar cells

    NASA Technical Reports Server (NTRS)

    Appelbaum, J.; Chait, A.; Thompson, D. A.

    1993-01-01

    Because solar cells in a production batch are not identical, screening is performed to obtain similar cells for aggregation into arrays. A common technique for screening is based on a single operating point of the I-V characteristic of the cell, usually the maximum power point. As a result, inferior cell matching may occur at the actual operating points. Screening solar cells based on the entire I-V characteristic will inherently result in more similar cells in the array. An array consisting of more similar cells is likely to have better overall characteristics and more predictable performance. Solar cell screening methods and cell ranking are discussed. The concept of a mean cell is defined as a cell 'best' representing all the cells in the production batch. The screening and ranking of all cells are performed with respect to the mean cell. The comparative results of different screening methods are illustrated on a batch of 50 silicon cells of the Space Station Freedom.

  19. Visualization of Cell-Cell Interaction Contacts

    PubMed Central

    2011-01-01

    T-cell activation requires interactions of T-cell antigen receptors (TCR) and peptides presented by major histocompatibility complex molecules (MHCp) in an adhesive junction between the T-cell and antigen-presenting cell (APC). Stable junctions with bull's eye supramolecular activation clusters (SMACs) have been defined as immunological synapses. The term synapse works in this case because it joins roots for “same” and “fasten,” which could be translated as “fasten in the same place.” These structures maintain T-cell-APC interaction and allow directed secretion. We have proposed that SMACs are not really clusters, but are analogous to higher order membrane-cytoskeleton zones involved in amoeboid locomotion including a substrate testing lamellipodium, an adhesive lamella and anti-adhesive uropod. Since T-cells can also integrate signaling during locomotion over antigen presenting cells, it is important to consider adhesive junctions maintained as cells move past each other. This combination of movement (kine-) and fastening (-apse) can be described as a kinapse or moving junction. Synapses and kinapses operate in different stages of T-cell priming. Optimal effector functions may also depend upon cyclical use of synapses and kinapses. Visualization of these structures in vitro and in vivo presents many distinct challenges that will be discussed in this paper. PMID:22299060

  20. Analytical pyrolysis of cells and cell fragments

    SciTech Connect

    Faix, O.; Bertelt, E.

    1995-12-01

    Wood of spruce, beech and birch was disintegrated without chemical pretreatment after 10 minutes of steaming at 110{degrees}C in a laboratory defibrator. Fibers, vessels, and fragments of secondary wall were separated by wet screening. A hydrocylon was used for separation of middle lamellae. By using analytical pyrolysis-GC/MS, parenchymatic cells were found to be richer in lignin than the other cells. The lignin content of middle lamellae was 35% (beech, spruce) and 39% (birch). In agreement with the literature, the S/G ratios of the vessels and middle lamellae was lower than those of the other cells and cell fragments.

  1. Liver cell adenoma and liver cell adenomatosis

    PubMed Central

    Barthelmes, Ludger

    2005-01-01

    During the last three decades liver cell adenoma and liver cell adenomatosis have emerged as new clinical entities in hepato-logical practice due to the widespread use of oral contraceptives and increased imaging of the liver. On review of published series there is evidence that 10% of liver cell adenomas progress to hepatocellular carcinoma, diagnosis is best made by open or laparoscopic excision biopsy, and the preferred treatment modality is resection of the liver cell adenoma to prevent bleeding and malignant transformation. In liver cell adenomatosis, the association with oral contraceptive use is not as high as in solitary liver cell adenomas. The risk of malignant transformation is not increased compared with solitary liver cell adenomas. Treatment consists of close monitoring and imaging, resection of superficially located, large (>4 cm) or growing liver cell adenomas. Liver transplantation is the last resort in case of substantive concern about malignant transformation or for large, painful adenomas in liver cell adenomatosis after treatment attempts by liver resection. PMID:18333188

  2. Bioelectrochemistry of cell surfaces

    NASA Astrophysics Data System (ADS)

    Dolowy, Krzysztof

    This paper deals with processes and phenomena of cell surface bioelectrochemistry in which charges do not move across the cell membrane. First, electrochemical properties of the cell membrane and the cell medium interface are described, and different electric potentials present in biological systems are defined. Methods of cell electrophoresis are then discussed. It is shown that none of the simple electrochemical models of the cell membrane can explain the dependence of cell electrophoretic mobility upon ionic strength and other electrochemical properties of the cell membrane, such as the difference in cell membrane charge as determined electrochemically and biochemically, or the effect of neuraminidase, pH, or membrane potential change on cell electrophoretic mobility. Thus, it is apparent that conclusions drawn from electrophoretic mobility data on the basis of simple models are false. The more complex multilayer-electrochemical model of the cell membrane is then described and shown to explain most electrochemical properties of the cell membrane. Next, different electrochemical techniques that were applied to study cell surfaces are described. It is shown that colloid titration, isoelectric focusing, and partition of cells between two immiscible phases is dependent not only on electrical properties of the cell membrane, but also on the energy of adsorption at cell surfaces of organic molecules used in these methods. Powder electrodes, cell polarography, conductometric titration, and Donnan potential methods are described and it is shown that these methods also produce results of doubtful value and are also often misinterpreted. The contact potential difference method produces results difficult to interpret and only electro-osmotic measurements and potential sensitive molecules are valuable methods. The colloid particle interaction theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO) as applied to cell interactions is discussed. It is shown that the

  3. Mast cells enhance T cell activation: Importance of mast cell-derived TNF

    NASA Astrophysics Data System (ADS)

    Nakae, Susumu; Suto, Hajime; Kakurai, Maki; Sedgwick, Jonathon D.; Tsai, Mindy; Galli, Stephen J.

    2005-05-01

    Mast cells are not only important effector cells in immediate hypersensitivity reactions and immune responses to pathogens but also can contribute to T cell-mediated disorders. However, the mechanisms by which mast cells might influence T cells in such settings are not fully understood. We find that mast cells can enhance proliferation and cytokine production in multiple T cell subsets. Mast cell-dependent enhancement of T cell activation can be promoted by FcRI-dependent mast cell activation, TNF production by both mast cells and T cells, and mast cell-T cell contact. However, at high concentrations of cells, mast cells can promote T cell activation independent of IgE or TNF. Finally, mast cells also can promote T cell activation by means of soluble factors. These findings identify multiple mechanisms by which mast cells can influence T cell proliferation and cytokine production. allergy | asthma | autoimmunity | cytokines | immune response

  4. Single cell mechanics of keratinocyte cells.

    PubMed

    Lulevich, Valentin; Yang, Hsin-ya; Isseroff, R Rivkah; Liu, Gang-yu

    2010-11-01

    Keratinocytes represent the major cell type of the uppermost layer of human skin, the epidermis. Using AFM-based single cell compression, the ability of individual keratinocytes to resist external pressure and global rupturing forces is investigated and compared with various cell types. Keratinocytes are found to be 6-70 times stiffer than other cell types, such as white blood, breast epithelial, fibroblast, or neuronal cells, and in contrast to other cell types they retain high mechanic strength even after the cell's death. The absence of membrane rupturing peaks in the force-deformation profiles of keratinocytes and their high stiffness during a second load cycle suggests that their unique mechanical resistance is dictated by the cytoskeleton. A simple analytical model enables the quantification of Young's modulus of keratinocyte cytoskeleton, as high as 120-340 Pa. Selective disruption of the two major cytoskeletal networks, actin filaments and microtubules, does not significantly affect keratinocyte mechanics. F-actin is found to impact cell deformation under pressure. During keratinocyte compression, the plasma membrane stretches to form peripheral blebs. Instead of blebbing, cells with depolymerized F-actin respond to pressure by detaching the plasma membrane from the cytoskeleton underneath. On the other hand, the compression force of keratinocytes expressing a mutated keratin (cell line, KEB-7) is 1.6-2.2 times less than that for the control cell line that has normal keratin networks. Therefore, we infer that the keratin intermediate filament network is responsible for the extremely high keratinocyte stiffness and resilience. This could manifest into the rugged protective nature of the human epidermis.

  5. Quantitative Characterization of Cell Behaviors through Cell Cycle Progression via Automated Cell Tracking

    PubMed Central

    Wang, Yuliang; Jeong, Younkoo; Jhiang, Sissy M.; Yu, Lianbo; Menq, Chia-Hsiang

    2014-01-01

    Cell behaviors are reflections of intracellular tension dynamics and play important roles in many cellular processes. In this study, temporal variations in cell geometry and cell motion through cell cycle progression were quantitatively characterized via automated cell tracking for MCF-10A non-transformed breast cells, MCF-7 non-invasive breast cancer cells, and MDA-MB-231 highly metastatic breast cancer cells. A new cell segmentation method, which combines the threshold method and our modified edge based active contour method, was applied to optimize cell boundary detection for all cells in the field-of-view. An automated cell-tracking program was implemented to conduct live cell tracking over 40 hours for the three cell lines. The cell boundary and location information was measured and aligned with cell cycle progression with constructed cell lineage trees. Cell behaviors were studied in terms of cell geometry and cell motion. For cell geometry, cell area and cell axis ratio were investigated. For cell motion, instantaneous migration speed, cell motion type, as well as cell motion range were analyzed. We applied a cell-based approach that allows us to examine and compare temporal variations of cell behavior along with cell cycle progression at a single cell level. Cell body geometry along with distribution of peripheral protrusion structures appears to be associated with cell motion features. Migration speed together with motion type and motion ranges are required to distinguish the three cell-lines examined. We found that cells dividing or overlapping vertically are unique features of cell malignancy for both MCF-7 and MDA-MB-231 cells, whereas abrupt changes in cell body geometry and cell motion during mitosis are unique to highly metastatic MDA-MB-231 cells. Taken together, our live cell tracking system serves as an invaluable tool to identify cell behaviors that are unique to malignant and/or highly metastatic breast cancer cells. PMID:24911281

  6. Microscale Fuel Cells

    SciTech Connect

    Holladay, Jamie D.; Viswanathan, Vish V.

    2005-11-03

    Perhaprs some of the most innovative work on fuel cells has been the research dedicated to applying silicon fabrication techniques to fuel cells technology creating low power microscale fuel cells applicable to microelectro mechanical systems (MEMS), microsensors, cell phones, PDA’s, and other low power (0.001 to 5 We) applications. In this small power range, fuel cells offer the decoupling of the energy converter from the energy storage which may enable longer operating times and instant or near instant charging. To date, most of the microscale fuel cells being developed have been based on proton exchange membrane fuel cell technology (PEMFC) or direct methanol fuel cell (DMFC) technology. This section will discuss requirements and considerations that need to be addressed in the development of microscale fuel cells, as well as some proposed designs and fabrication strategies.

  7. Bacterial Cell Wall Components

    NASA Astrophysics Data System (ADS)

    Ginsberg, Cynthia; Brown, Stephanie; Walker, Suzanne

    Bacterial cell-surface polysaccharides cells are surrounded by a variety of cell-surface structures that allow them to thrive in extreme environments. Components of the cell envelope and extracellular matrix are responsible for providing the cells with structural support, mediating intercellular communication, allowing the cells to move or to adhere to surfaces, protecting the cells from attack by antibiotics or the immune system, and facilitating the uptake of nutrients. Some of the most important cell wall components are polysaccharide structures. This review discusses the occurrence, structure, function, and biosynthesis of the most prevalent bacterial cell surface polysaccharides: peptidoglycan, lipopolysaccharide, arabinogalactan, and lipoarabinomannan, and capsular and extracellular polysaccharides. The roles of these polysaccharides in medicine, both as drug targets and as therapeutic agents, are also described.

  8. Plant stem cell niches.

    PubMed

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  9. Tetraspanins in Cell Migration

    PubMed Central

    Jiang, Xupin; Zhang, Jiaping; Huang, Yuesheng

    2015-01-01

    Tetraspanins are a superfamily of small transmembrane proteins that are expressed in almost all eukaryotic cells. Through interacting with one another and with other membrane and intracellular proteins, tetraspanins regulate a wide range of proteins such as integrins, cell surface receptors, and signaling molecules, and thereby engage in diverse cellular processes ranging from cell adhesion and migration to proliferation and differentiation. In particular, tetraspanins modulate the function of proteins involved in all determining factors of cell migration including cell–cell adhesion, cell–ECM adhesion, cytoskeletal protrusion/contraction, and proteolytic ECM remodeling. We herein provide a brief overview of collective in vitro and in vivo studies of tetraspanins to illustrate their regulatory functions in the migration and trafficking of cancer cells, vascular endothelial cells, skin cells (keratinocytes and fibroblasts), and leukocytes. We also discuss the involvement of tetraspanins in various pathologic and remedial processes that rely on cell migration and their potential value as targets for therapeutic intervention. PMID:26091149

  10. Apigenin inhibits renal cell carcinoma cell proliferation.

    PubMed

    Meng, Shuai; Zhu, Yi; Li, Jiang-Feng; Wang, Xiao; Liang, Zhen; Li, Shi-Qi; Xu, Xin; Chen, Hong; Liu, Ben; Zheng, Xiang-Yi; Xie, Li-Ping

    2017-03-21

    Apigenin, a natural flavonoid found in vegetables and fruits, has antitumor activity in several cancer types. The present study evaluated the effects and mechanism of action of apigenin in renal cell carcinoma (RCC) cells. We found that apigenin suppressed ACHN, 786-0, and Caki-1 RCC cell proliferation in a dose- and time-dependent manner. A comet assay suggested that apigenin caused DNA damage in ACHN cells, especially at higher doses, and induced G2/M phase cell cycle arrest through ATM signal modulation. Small interfering RNA (siRNA)-mediated p53 knockdown showed that apigenin-induced apoptosis was likely p53 dependent. Apigenin anti-proliferative effects were confirmed in an ACHN cell xenograft mouse model. Apigenin treatment reduced tumor growth and volume in vivo, and immunohistochemical staining revealed lower Ki-67 indices in tumors derived from apigenin-treated mice. These findings suggest that apigenin exposure induces DNA damage, G2/M phase cell cycle arrest, p53 accumulation and apoptosis, which collectively suppress ACHN RCC cell proliferation in vitro and in vivo. Given its antitumor effects and low in vivo toxicity, apigenin is a highly promising agent for treatment of RCC.

  11. Mechanical guidance through cell-cell and cell-surface contact during multicellular streaming

    NASA Astrophysics Data System (ADS)

    Wang, Chenlu; Driscoll, Meghan; Gupta, Satyandra K.; Parent, Carole; Losert, Wolfgang

    2014-03-01

    During collective cell migration, mechanical forces arise from the extracellular matrix (ECM) through cell-surface contact and from other cells through cell-cell contact. These forces regulate the motion of migrating cell groups. To determine how these mechanical interactions balance during cell migration, we measured the shape dynamics of Dictyostelium discoideum cells at the multicellular streaming stage. We found that cells can coordinate their motion by synchronizing protrusion waves that travel along their membranes when they form proper cell-cell adhesion and cell-surface adhesion. In addition, our experiments on live actin labeled cells show that intracellular actin polymerization actively responds to the change of cell-cell/surface adhesion and helps to stabilize multicellular migration streams. Our finding suggests that the coordination of motion between neighboring cells in collective migration requires a balance between cell-cell adhesion and cell-surface adhesion, and that the cell cytoskeleton plays an important role in this balance.

  12. Induction of Functional Hair-Cell-Like Cells from Mouse Cochlear Multipotent Cells

    PubMed Central

    Liu, Quanwen; Shen, Yi; Chen, Jiarong; Ding, Jie; Tang, Zihua; Zhang, Cui; Chen, Jianling; Li, Liang; Chen, Ping; Wang, Jinfu

    2016-01-01

    In this paper, we developed a two-step-induction method of generating functional hair cells from inner ear multipotent cells. Multipotent cells from the inner ear were established and induced initially into progenitor cells committed to the inner ear cell lineage on the poly-L-lysine substratum. Subsequently, the committed progenitor cells were cultured on the mitotically inactivated chicken utricle stromal cells and induced into hair-cell-like cells containing characteristic stereocilia bundles. The hair-cell-like cells exhibited rapid permeation of FM1-43FX. The whole-cell patch-clamp technique was used to measure the membrane currents of cells differentiated for 7 days on chicken utricle stromal cells and analyze the biophysical properties of the hair-cell-like cells by recording membrane properties of cells. The results suggested that the hair-cell-like cells derived from inner ear multipotent cells were functional following differentiation in an enabling environment. PMID:27057177

  13. Thin cells for space

    NASA Technical Reports Server (NTRS)

    Storti, G.; Wohlgemuth, J.; Wrigley, C.

    1979-01-01

    Research and pilot line production efforts directed towards the fabrication of high efficiency ultrathin silicon solar cells (50 micrometers) are reported. Conventional ultrathin cells with air-mass-zero (AM0) efficiencies exceeding 14% and coplanar back contact cells with AM0 efficiencies up to 11.7% were developed. The primary mechanisms limiting efficiency were determined in both types of cells, and they are discussed within the context of further improving efficiency. Results of pilot line production of conventional ultrathin cells are also presented. Average AM0 efficiencies of 12% were readily achieved for 2000 cell production runs.

  14. Microfluidics for manipulating cells.

    PubMed

    Mu, Xuan; Zheng, Wenfu; Sun, Jiashu; Zhang, Wei; Jiang, Xingyu

    2013-01-14

    Microfluidics, a toolbox comprising methods for precise manipulation of fluids at small length scales (micrometers to millimeters), has become useful for manipulating cells. Its uses range from dynamic management of cellular interactions to high-throughput screening of cells, and to precise analysis of chemical contents in single cells. Microfluidics demonstrates a completely new perspective and an excellent practical way to manipulate cells for solving various needs in biology and medicine. This review introduces and comments on recent achievements and challenges of using microfluidics to manipulate and analyze cells. It is believed that microfluidics will assume an even greater role in the mechanistic understanding of cell biology and, eventually, in clinical applications.

  15. Natural Killer Cell Memory

    PubMed Central

    O’Sullivan, Timothy E.; Sun, Joseph C.; Lanier, Lewis L.

    2015-01-01

    Natural killer (NK) cells have historically been considered short-lived cytolytic cells that can rapidly respond against pathogens and tumors in an antigen-independent manner, and then undergo cell death. Recently, however, NK cells have been shown to possess traits of adaptive immunity, and can acquire immunological memory in a similar manner to T and B cells. In this review, we discuss evidence for NK cell memory and the mechanisms involved in the generation and survival of these innate lymphocytes. PMID:26488815

  16. Cytokinesis in Animal Cells

    PubMed Central

    D’Avino, Pier Paolo; Giansanti, Maria Grazia; Petronczki, Mark

    2015-01-01

    Cell division ends with the physical separation of the two daughter cells, a process known as cytokinesis. This final event ensures that nuclear and cytoplasmic contents are accurately partitioned between the two nascent cells. Cytokinesis is one of the most dramatic changes in cell shape and requires an extensive reorganization of the cell’s cytoskeleton. Here, we describe the cytoskeletal structures, factors, and signaling pathways that orchestrate this robust and yet highly dynamic process in animal cells. Finally, we discuss possible future directions in this growing area of cell division research and its implications in human diseases, including cancer. PMID:25680833

  17. Alloreactive T cell clones.

    PubMed

    Fitch, F W

    1984-01-01

    T cell clones are useful models for studying lymphocyte function both at the level of the individual cell and in interacting systems. Murine cytolytic and non- cytolyic T cell clones have been obtained with relative ease, and the particular procedure used to derive and maintain T cell clones may influence profoundly the characteristics of the resulting cells. The method of choice depends on the specific question to be asked. Although some clones have characteristics that would have been expected on the basis of results observed with bulk cell populations, other clones have rather unexpected properties. Although most T cell clones appear to be either cytolytic or non-cytolytic, this distinction is not always absolute. A high proportion of both cytolytic and non-cytolytic T cell clones have dual reactivity. This is true for cells which by other criteria appear to be true clones. The frequency of such cells is high enough to suggest that most if not all T cells may have reactivity for more than one antigenic determinant or that antigenic determinants recognized by T cells are shared widely and unexpectedly. It is not clear whether one or two different antigen receptors account for such dual reactivity. The nature of the T cell receptor for antigen remains obscure. T cell clones, because of their homogeneous nature, should make it easier to answer these important immunological questions. Although it remains to be determined how many distinct molecules account for the numerous biological activities found in the culture supernatants from antigen-stimulated T cell clones, it is clear that these factors influence several different types of cells that are involved directly and indirectly in immune responses. IL-2 stimulates both cytolytic and non-cytolytic T cells to proliferate. BCSF causes polyclonal activation of B cells, and there may be other factors which influence B cell responses to antigenic stimulation. IL-3 apparently stimulates maturation of immature T cells

  18. Assessment of pancreas cells

    NASA Technical Reports Server (NTRS)

    Vanoss, C. J.

    1978-01-01

    Pancreatic islets were obtained from guinea pig pancreas by the collagenase method and kept alive in tissue culture prior to further studies. Pancreas cell morphology was studied by standard histochemical techniques using light microscopy. Preparative vertical electrophoresis-levitation of dispersed fetal guinea pig pancreas cells was conducted in phosphate buffer containing a heavy water (D20) gradient which does not cause clumping of cells or alter the osmolarity of the buffers. The faster migrating fractions tended to be enriched in beta-cell content. Alpha and delta cells were found to some degree in most fractions. A histogram showing the cell count distribution is included.

  19. Natural Killer Cell Memory.

    PubMed

    O'Sullivan, Timothy E; Sun, Joseph C; Lanier, Lewis L

    2015-10-20

    Natural killer (NK) cells have historically been considered short-lived cytolytic cells that can rapidly respond against pathogens and tumors in an antigen-independent manner and then undergo cell death. Recently, however, NK cells have been shown to possess traits of adaptive immunity and can acquire immunological memory in a manner similar to that of T and B cells. In this review, we discuss evidence of NK cell memory and the mechanisms involved in the generation and survival of these innate lymphocytes.

  20. Pluripotent stem cells for Schwann cell engineering.

    PubMed

    Ma, Ming-San; Boddeke, Erik; Copray, Sjef

    2015-04-01

    Tissue engineering of Schwann cells (SCs) can serve a number of purposes, such as in vitro SC-related disease modeling, treatment of peripheral nerve diseases or peripheral nerve injury, and, potentially, treatment of CNS diseases. SCs can be generated from autologous stem cells in vitro by recapitulating the various stages of in vivo neural crest formation and SC differentiation. In this review, we survey the cellular and molecular mechanisms underlying these in vivo processes. We then focus on the current in vitro strategies for generating SCs from two sources of pluripotent stem cells, namely embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Different methods for SC engineering from ESCs and iPSCs are reviewed and suggestions are proposed for optimizing the existing protocols. Potential safety issues regarding the clinical application of iPSC-derived SCs are discussed as well. Lastly, we will address future aspects of SC engineering.

  1. Alternative Cell Death Pathways and Cell Metabolism

    PubMed Central

    Fulda, Simone

    2013-01-01

    While necroptosis has for long been viewed as an accidental mode of cell death triggered by physical or chemical damage, it has become clear over the last years that necroptosis can also represent a programmed form of cell death in mammalian cells. Key discoveries in the field of cell death research, including the identification of critical components of the necroptotic machinery, led to a revised concept of cell death signaling programs. Several regulatory check and balances are in place in order to ensure that necroptosis is tightly controlled according to environmental cues and cellular needs. This network of regulatory mechanisms includes metabolic pathways, especially those linked to mitochondrial signaling events. A better understanding of these signal transduction mechanisms will likely contribute to open new avenues to exploit our knowledge on the regulation of necroptosis signaling for therapeutic application in the treatment of human diseases. PMID:23401689

  2. T helper cell cytotoxicity

    SciTech Connect

    Penna, A.; Glasebrook, A.

    1986-03-01

    It has recently been shown that helper T cells (Lyt2/sup -/, L3T4/sup +/) can express cytolytic activity when activated by antigen (Ag). The authors have studied the phenomenon of T helper cell cytotoxicity using cloned lines of Ag-reactive T cells and T hybrids. Cytotoxicity was determined by coculture of T cells with /sup 51/Cr-labelled Ag presenting cells (APC) and/or non-APC (bystander cells). A high frequency of Ag-specific L3T4/sup +/ T cell clones (> 90%) and hybrids (> 50%) were found to be cytotoxic. Cytotoxicity as determined by /sup 51/Cr release was maximal at 20 hr with little or no cytotoxicity detectable at 6 hr. Target cells, either APC or bystander cells, were killed provided the T cells were stimulated by Ag. Not all of the B cells used as APC were susceptible targets even if able to promote bystander killing. Monoclonal antibodies directed against L3T4, LFA-1 and T cell receptor molecules were able to block the cytotoxicity indicating a requirement for specific activation of the T cells. Cyclosporin A (CsA) reduced the cytotoxic activity of helper T hybrids and clones, while it did not affect the cytotoxic activity of Lyt2/sup +/, L3T4/sup -/ cytolytic T cell (CTL) clones. The delayed expression of cytotoxic activity, the lysis of bystander cells and inhibition by CsA suggest that the cytolytic mechanism is mediated by a soluble factor and different from the cytolytic mechanism of CTL. The phenomenon of cytotoxic T helper cells may be relevant to suppression of B cell immune responses in vivo.

  3. Colorectal cancer stem cells.

    PubMed

    Salama, Paul; Platell, Cameron

    2009-10-01

    Somatic stem cells reside at the base of the crypts throughout the colonic mucosa. These cells are essential for the normal regeneration of the colonic epithelium. The stem cells reside within a special 'niche' comprised of intestinal sub-epithelial myofibroblasts that tightly control their function. It has been postulated that mutations within these adult colonic stem cells may induce neoplastic changes. Such cells can then dissociate from the epithelium and travel into the mesenchyme and thus form invasive cancers. This theory is based on the observation that within a colon cancer, less than 1% of the neoplastic cells have the ability to regenerate the tumour. It is this group of cells that exhibits characteristics of colonic stem cells. Although anti-neoplastic agents can induce remissions by inhibiting cell division, the stem cells appear to be remarkably resistant to both standard chemotherapy and radiotherapy. These stem cells may therefore persist after treatment and form the nucleus for cancer recurrence. Hence, future treatment modalities should focus specifically on controlling the cancer stem cells. In this review, we discuss the biology of normal and malignant colonic stem cells.

  4. The cell cycle as a brake for β-cell regeneration from embryonic stem cells.

    PubMed

    El-Badawy, Ahmed; El-Badri, Nagwa

    2016-01-13

    The generation of insulin-producing β cells from stem cells in vitro provides a promising source of cells for cell transplantation therapy in diabetes. However, insulin-producing cells generated from human stem cells show deficiency in many functional characteristics compared with pancreatic β cells. Recent reports have shown molecular ties between the cell cycle and the differentiation mechanism of embryonic stem (ES) cells, assuming that cell fate decisions are controlled by the cell cycle machinery. Both β cells and ES cells possess unique cell cycle machinery yet with significant contrasts. In this review, we compare the cell cycle control mechanisms in both ES cells and β cells, and highlight the fundamental differences between pluripotent cells of embryonic origin and differentiated β cells. Through critical analysis of the differences of the cell cycle between these two cell types, we propose that the cell cycle of ES cells may act as a brake for β-cell regeneration. Based on these differences, we discuss the potential of modulating the cell cycle of ES cells for the large-scale generation of functionally mature β cells in vitro. Further understanding of the factors that modulate the ES cell cycle will lead to new approaches to enhance the production of functional mature insulin-producing cells, and yield a reliable system to generate bona fide β cells in vitro.

  5. Single-cell growth analysis in a mixed cell culture

    NASA Astrophysics Data System (ADS)

    Ando, Jun; Bato, Mary Grace P.; Daria, Vincent Ricardo

    2008-06-01

    We perform single cell analysis of cell growth in a mixed cell culture. Two species of yeast cells: Saccharomyces cerevisiae and Candida albicans, are optically trapped using focused continuous-wave near infrared laser. Cell growth for both cells is inhibited only when the two species of cells are in contact with each other. This indicates cell-cell interaction mediated cell growth inhibition mechanism. Single cell level analysis of cell growth studied here contributes to the further understanding of yeast growth arrest in a mixed yeast culture.

  6. Giant Cell Arteritis

    MedlinePlus

    Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

  7. Regulatory T cells.

    PubMed

    Thompson, Claire; Powrie, Fiona

    2004-08-01

    Regulatory T (TR) cells are a subset of T cells that function to control immune responses. Different populations of TR cells have been described, including thymically derived CD4(+)CD25+ TR cells and Tr1 cells induced in the periphery through exposure to antigen. A transcription factor, Foxp3, has been identified that is essential for CD4(+)CD25+ TR cell development and function. There is now evidence that transforming growth factor-beta might play a role in this pathway. CD4(+)CD25+ TR cells proliferate extensively in vivo in an antigen-specific manner, and can respond to both self and foreign peptides. By suppressing excessive immune responses, TR cells play a key role in the maintenance of self-tolerance, thus preventing autoimmune disease, as well as inhibiting harmful inflammatory diseases such as asthma and inflammatory bowel disease.

  8. Stem Cell Transplant

    MedlinePlus

    ... transplant is a procedure that infuses healthy blood stem cells into your body to replace your damaged or ... A bone marrow transplant is also called a stem cell transplant. A bone marrow transplant may be necessary ...

  9. Red blood cell production

    MedlinePlus

    ... to one part of the body or another. Red blood cells are an important element of blood. Their job ... is carried to and eliminated by the lungs. Red blood cells are formed in the red bone marrow of ...

  10. Odontogenic ghost cell tumour with clear cell components: clear cell odontogenic ghost cell tumour?

    PubMed

    Yoon, Jung Hoon; Ahn, Sang Gun; Kim, Su Gwan; Kim, Jin

    2004-07-01

    A case of odontogenic ghost cell tumour (OGCT) with clear cell components was encountered in the mandible of a 63-year-old man. The tumour revealed ameloblastomatous-type epithelial components accompanied by clusters of ghost cells and dentinoid juxtaposed to the odontogenic epithelium. In addition, some areas of the tumour tissue showed sheets and islands of clear, glycogen containing epithelial cells, which were separated by a thin fibrous connective tissue stroma. Both ameloblastic and clear cells exhibited positive immunoreactivities for cytokeratin 19 and AE1/3. It is not known whether this tumour represents a clear cell change of a pre-existing OGCT or a separate and distinct neoplasm derived de novo from the odontogenic epithelium. This tumour was given the term 'clear cell OGCT' because it captures the clear cell components, which is one of the most prominent distinguishing features of the tumour.

  11. White Blood Cell Count

    MedlinePlus

    ... limited. Home Visit Global Sites Search Help? White Blood Cell Count Share this page: Was this page helpful? ... Count; Leukocyte Count; White Count Formal name: White Blood Cell Count Related tests: Complete Blood Count , Blood Smear , ...

  12. Single-cell nanosurgery.

    PubMed

    Zeigler, Maxwell B; Chiu, Daniel T

    2013-01-01

    This chapter explains the steps necessary to perform laser surgery upon single adherent mammalian cells, where individual organelles are extracted from the cells by optical tweezers and the cells are monitored post-surgery to check their viability. Single-cell laser nanosurgery is used in an increasing range of methodologies because it offers great flexibility. Its main advantages are (a) there is not any physical contact with the cells so they remain in a sterile environment, (b) high spatial selectivity so that single organelles can be extracted from specific areas of individual cells, (c) the method can be conducted in the cell's native media, and (d) in comparison to other techniques that target single cells, such as micromanipulators, laser nanosurgery has a comparatively high throughput.

  13. Fluorescence Live Cell Imaging

    PubMed Central

    Ettinger, Andreas

    2014-01-01

    Fluorescence microscopy of live cells has become an integral part of modern cell biology. Fluorescent protein tags, live cell dyes, and other methods to fluorescently label proteins of interest provide a range of tools to investigate virtually any cellular process under the microscope. The two main experimental challenges in collecting meaningful live cell microscopy data are to minimize photodamage while retaining a useful signal-to-noise ratio, and to provide a suitable environment for cells or tissues to replicate physiological cell dynamics. This chapter aims to give a general overview on microscope design choices critical for fluorescence live cell imaging that apply to most fluorescence microscopy modalities, and on environmental control with a focus on mammalian tissue culture cells. In addition, we provide guidance on how to design and evaluate fluorescent protein constructs by spinning disk confocal microscopy. PMID:24974023

  14. Cell phone explosion.

    PubMed

    Atreya, Alok; Kanchan, Tanuj; Nepal, Samata; Pandey, Bhuwan Raj

    2016-03-01

    Cell phone explosions and resultant burn injuries are rarely reported in the scientific literature. We report a case of cell phone explosion that occurred when a young male was listening to music while the mobile was plugged in for charging.

  15. FUEL CELL ELECTRODE MATERIALS

    DTIC Science & Technology

    FUEL CELL ELECTRODE MATERIALS. RAW MATERIAL SELECTION INFLUENCES POLARIZATION BUT IS NOT A SINGLE CONTROLLING FACTOR. AVAILABLE...DATA INDICATES THAT AN INTERRELATIONSHIP OF POROSITY, AVERAGE PORE VOLUME, AND PERMEABILITY CONTRIBUTES TO ELECTRODE FUEL CELL BEHAVIOR.

  16. Sickle Cell Information Center

    MedlinePlus

    ... procedure for stem cell transplantation from healthy, ... NYT, Nature, Wash Post, SciAm, CNN - Google Custom Search Sickle ... summarizing medical research on sickle-cell anemia. NYT, Nature, Wash Post, SciAm, CNN - Google Custom Search Genetic ...

  17. Learn About Stem Cells

    MedlinePlus

    ... to survive, including the umbilical cord and the placenta that nourishes the developing fetus. Basic cell biology ... types but cannot generate support structures like the placenta and umbilical cord. Other cells are multipotent, meaning ...

  18. Sickle Cell Disease

    MedlinePlus

    ... About Us Overview of CDC’s work. Advancements in Sickle Cell Disease New supplement from the American Journal of Preventive Medicine describes the state of sickle cell disease related care in the United States. Read Supplement ...

  19. Stem cells remember their grade.

    PubMed

    Lo Celso, Cristina; Scadden, David T

    2007-08-16

    The stem cell state is understood based on what cells do in performance assays, crude measures of a highly refined state. In this issue of Cell Stem Cell, Dykstra et al. (2007) reveal stem cell gradation and the extent to which that gradation is retained in stem cell daughters of hematopoietic stem cells.

  20. Diagram of Cell to Cell Communication

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Diagram depicts the importance of cell-cell communication as central to the understanding of cancer growth and progression, the focus of the NASA bioreactor demonstration system (BDS-05) investigation. Microgravity studies will allow us to unravel the signaling and communication between these cells with the host and potential development of therapies for the treatment of cancer metastasis. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: Emory University.

  1. Cell-cell connectivity: desmosomes and disease.

    PubMed

    Brooke, Matthew A; Nitoiu, Daniela; Kelsell, David P

    2012-01-01

    Cell-cell connectivity is an absolute requirement for the correct functioning of cells, tissues and entire organisms. At the level of the individual cell, direct cell-cell adherence and communication is mediated by the intercellular junction complexes: desmosomes, adherens, tight and gap junctions. A broad spectrum of inherited, infectious and auto-immune diseases can affect the proper function of intercellular junctions and result in either diseases affecting specific individual tissues or widespread syndromic conditions. A particularly diverse group of diseases result from direct or indirect disruption of desmosomes--a consequence of their importance in tissue integrity, their extensive distribution, complex structure, and the wide variety of functions their components accomplish. As a consequence, disruption of desmosomal assembly, structure or integrity disrupts not only their intercellular adhesive function but also their functions in cell communication and regulation, leading to such diverse pathologies as cardiomyopathy, epidermal and mucosal blistering, palmoplantar keratoderma, woolly hair, keratosis, epidermolysis bullosa, ectodermal dysplasia and alopecia. Here, as well as describing the importance of the other intercellular junctions, we focus primarily on the desmosome, its structure and its role in disease. We will examine the various pathologies that result from impairment of desmosome function and thereby demonstrate the importance of desmosomes to tissues and to the organism as a whole.

  2. Germ Cell Differentiation from Pluripotent Cells

    PubMed Central

    Medrano, Jose V.; Pera, Renee A. Reijo; Simón, Carlos

    2014-01-01

    Infertility is a medical condition with an increasing impact in Western societies with causes linked to toxins, genetics, and aging (primarily delay of motherhood). Within the different pathologies that can lead to infertility, poor quality or reduced quantity of gametes plays an important role. Gamete donation and therefore demand on donated sperm and eggs in fertility clinics is increasing. It is hoped that a better understanding of the conditions related to poor gamete quality may allow scientists to design rational treatments. However, to date, relatively little is known about human germ cell development in large part due to the inaccessibility of human development to molecular genetic analysis. It is hoped that pluripotent human embryonic stem cells and induced pluripotent stem cells may provide an accessible in vitro model to study germline development; these cells are able to differentiate to cells of all three primary embryonic germ layers, as well as to germ cells in vitro. We review the state of the art in germline differentiation from pluripotent stem cells. PMID:23329632

  3. Diagram of Cell to Cell Communication

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Diagram depicts the importance of cell-cell communication as central to the understanding of cancer growth and progression, the focus of the NASA bioreactor demonstration system (BDS-05) investigation. Microgravity studies will allow us to unravel the signaling and communication between these cells with the host and potential development of therapies for the treatment of cancer metastasis. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: Emory University.

  4. Cell cycle regulates cell type in the Arabidopsis sepal.

    PubMed

    Roeder, Adrienne H K; Cunha, Alexandre; Ohno, Carolyn K; Meyerowitz, Elliot M

    2012-12-01

    The formation of cellular patterns during development requires the coordination of cell division with cell identity specification. This coordination is essential in patterning the highly elongated giant cells, which are interspersed between small cells, in the outer epidermis of the Arabidopsis thaliana sepal. Giant cells undergo endocycles, replicating their DNA without dividing, whereas small cells divide mitotically. We show that distinct enhancers are expressed in giant cells and small cells, indicating that these cell types have different identities as well as different sizes. We find that members of the epidermal specification pathway, DEFECTIVE KERNEL1 (DEK1), MERISTEM LAYER1 (ATML1), Arabidopsis CRINKLY4 (ACR4) and HOMEODOMAIN GLABROUS11 (HDG11), control the identity of giant cells. Giant cell identity is established upstream of cell cycle regulation. Conversely, endoreduplication represses small cell identity. These results show not only that cell type affects cell cycle regulation, but also that changes in the cell cycle can regulate cell type.

  5. Fuel cells feasibility

    NASA Technical Reports Server (NTRS)

    Schonfeld, D.; Charng, T.

    1981-01-01

    The technical and economic status of fuel cells is assessed with emphasis on their potential benefits to the Deep Space Network. The fuel cell, what it is, how it operates, and what its outputs are, is reviewed. Major technical problems of the fuel cell and its components are highlighted. Due to these problems and economic considerations it is concluded that fuel cells will not become commercially viable until the early 1990s.

  6. Increased voltage photovoltaic cell

    NASA Technical Reports Server (NTRS)

    Ross, B.; Bickler, D. B.; Gallagher, B. D. (Inventor)

    1985-01-01

    A photovoltaic cell, such as a solar cell, is provided which has a higher output voltage than prior cells. The improved cell includes a substrate of doped silicon, a first layer of silicon disposed on the substrate and having opposite doping, and a second layer of silicon carbide disposed on the first layer. The silicon carbide preferably has the same type of doping as the first layer.

  7. Regenerative fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, Larry L.; Kackley, Nancy D.; Laconti, Anthony B.

    1992-01-01

    A development status evaluation is presented for moderate-temperature, single-unit, regenerative fuel cells using either alkaline or solid polymer proton-exchange membrane (PEM) electrolytes. Attention is given to the results thus far obtained for Pt, Ir, Rh, and Na(x)Pt3O4 catalysts. Alkaline electrolyte tests have been performed on a half-cell basis with a floating-electrode cell; PEM testing has been with complete fuel cells, using Nafion 117.

  8. Regenerative fuel cells

    NASA Astrophysics Data System (ADS)

    Swette, Larry L.; Kackley, Nancy D.; Laconti, Anthony B.

    A development status evaluation is presented for moderate-temperature, single-unit, regenerative fuel cells using either alkaline or solid polymer proton-exchange membrane (PEM) electrolytes. Attention is given to the results thus far obtained for Pt, Ir, Rh, and Na(x)Pt3O4 catalysts. Alkaline electrolyte tests have been performed on a half-cell basis with a floating-electrode cell; PEM testing has been with complete fuel cells, using Nafion 117.

  9. Cross Cell Sandwich Core

    NASA Technical Reports Server (NTRS)

    Ford, Donald B. (Inventor)

    2004-01-01

    A sandwich core comprises two faceplates separated by a plurality of cells. The cells are comprised of walls positioned at oblique angles relative to a perpendicular axis extending through the faceplates. The walls preferably form open cells and are constructed from open cells and are constructed from rows of ribbons. The walls may be obliquely angled relative to more than one plane extending through the perpendicular axis.

  10. Clonogenic Assay: Adherent Cells

    PubMed Central

    Rafehi, Haloom; Orlowski, Christian; Georgiadis, George T.; Ververis, Katherine; El-Osta, Assam; Karagiannis, Tom C.

    2011-01-01

    The clonogenic (or colony forming) assay has been established for more than 50 years; the original paper describing the technique was published in 19561. Apart from documenting the method, the initial landmark study generated the first radiation-dose response curve for X-ray irradiated mammalian (HeLa) cells in culture1. Basically, the clonogenic assay enables an assessment of the differences in reproductive viability (capacity of cells to produce progeny; i.e. a single cell to form a colony of 50 or more cells) between control untreated cells and cells that have undergone various treatments such as exposure to ionising radiation, various chemical compounds (e.g. cytotoxic agents) or in other cases genetic manipulation. The assay has become the most widely accepted technique in radiation biology and has been widely used for evaluating the radiation sensitivity of different cell lines. Further, the clonogenic assay is commonly used for monitoring the efficacy of radiation modifying compounds and for determining the effects of cytotoxic agents and other anti-cancer therapeutics on colony forming ability, in different cell lines. A typical clonogenic survival experiment using adherent cells lines involves three distinct components, 1) treatment of the cell monolayer in tissue culture flasks, 2) preparation of single cell suspensions and plating an appropriate number of cells in petri dishes and 3) fixing and staining colonies following a relevant incubation period, which could range from 1-3 weeks, depending on the cell line. Here we demonstrate the general procedure for performing the clonogenic assay with adherent cell lines with the use of an immortalized human keratinocyte cell line (FEP-1811)2. Also, our aims are to describe common features of clonogenic assays including calculation of the plating efficiency and survival fractions after exposure of cells to radiation, and to exemplify modification of radiation-response with the use of a natural antioxidant

  11. [Hairy cell leukemia].

    PubMed

    Dietrich, S; Andrulis, M; Zenz, T

    2015-04-01

    Hairy cell leukemia was initially described as a distinct entity in 1958. It is rare B-cell malignancy characterized by an indolent course. Advances in the treatment and understanding of the biology of hairy cell leukemia have made the disease exquisitely amenable to treatment. This review summarizes the present understanding of hairy cell leukemia with a particular focus on the development of novel and targeted approaches to treatment.

  12. Fish Stem Cell Cultures

    PubMed Central

    Hong, Ni; Li, Zhendong; Hong, Yunhan

    2011-01-01

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on “Fish Stem Cells and Nuclear Transfer”, we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer. PMID:21547056

  13. Kidney Cell Electrophoresis

    NASA Technical Reports Server (NTRS)

    Todd, P.

    1985-01-01

    Materials and procedures for microgravity electrophoresis of living human embryonic kidney cells were evaluated, ground support in the form of analytical cell electrophoresis and flow cytometry was provided and cells returned from space flight were analyzed. Preflight culture media, electrophoresis buffer, fraction collection media, temperature profiles, and urokinase assay procedures were tested prior to flight. Electrophoretic mobility distributions of aliquots of the cell population to be fractionated in flight were obtained. The protocol established and utilized is given.

  14. Fuel cell status, 1994

    NASA Astrophysics Data System (ADS)

    Hirschenhofer, John H.

    1994-11-01

    Fuel cells are increasingly being used for commercial purposes in various countries worldwide because of their high efficiency environmental benefits. Among the nations which are pioneering the use of fuel cells are Australia, the United States, England, Japan, Germany, Netherlands, Belgium and Canada. These countries use fuel cells to augment the capacity of and improve the reliability of power plants fueled by natural gas.

  15. Cell phones and cancer

    MedlinePlus

    Cancer and cell phones; Do cell phones cause cancer? ... Several major studies show no link between cell phones and cancer at this time. However, since the information available is based on short-term studies, the impact of many years of ...

  16. Adventures with Cell Phones

    ERIC Educational Resources Information Center

    Kolb, Liz

    2011-01-01

    Teachers are finding creative ways to turn the basic cell phone from a digital distraction into a versatile learning tool. In this article, the author explains why cell phones are important in learning and suggests rather than banning them that they be integrated into learning. She presents activities that can be done on a basic cell phone with a…

  17. Solar Photovoltaic Cells.

    ERIC Educational Resources Information Center

    Mickey, Charles D.

    1981-01-01

    Reviews information on solar radiation as an energy source. Discusses these topics: the key photovoltaic material; the bank theory of solids; conductors, semiconductors, and insulators; impurity semiconductors; solid-state photovoltaic cell operation; limitations on solar cell efficiency; silicon solar cells; cadmium sulfide/copper (I) sulfide…

  18. Photoelectrochemical Solar Cells.

    ERIC Educational Resources Information Center

    McDevitt, John T.

    1984-01-01

    This introduction to photoelectrochemical (PEC) cells reviews topics pertaining to solar energy conversion and demonstrates the ease with which a working PEC cell can be prepared with n-type silicon as the photoanode and a platinum counter electrode (both immersed in ethanolic ferrocene/ferricenium solutions). Experiments using the cell are…

  19. Solar Photovoltaic Cells.

    ERIC Educational Resources Information Center

    Mickey, Charles D.

    1981-01-01

    Reviews information on solar radiation as an energy source. Discusses these topics: the key photovoltaic material; the bank theory of solids; conductors, semiconductors, and insulators; impurity semiconductors; solid-state photovoltaic cell operation; limitations on solar cell efficiency; silicon solar cells; cadmium sulfide/copper (I) sulfide…

  20. Islet Cell Transplantation

    MedlinePlus

    ... person who has type 1 diabetes must take insulin daily to live. Transplanted islet cells, however, can take over the work of the destroyed cells. The beta cells in these islets will begin to make and release insulin. Researchers hope islet transplantation will help people with ...

  1. Reprogramming of somatic cells.

    PubMed

    Rajasingh, Johnson

    2012-01-01

    Reprogramming of adult somatic cells into pluripotent stem cells may provide an attractive source of stem cells for regenerative medicine. It has emerged as an invaluable method for generating patient-specific stem cells of any cell lineage without the use of embryonic stem cells. A revolutionary study in 2006 showed that it is possible to convert adult somatic cells directly into pluripotent stem cells by using a limited number of pluripotent transcription factors and is called as iPS cells. Currently, both genomic integrating viral and nonintegrating nonviral methods are used to generate iPS cells. However, the viral-based technology poses increased risk of safety, and more studies are now focused on nonviral-based technology to obtain autologous stem cells for clinical therapy. In this review, the pros and cons of the present iPS cell technology and the future direction for the successful translation of this technology into the clinic are discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Mesothelial cell transplantation.

    PubMed

    Witkowicz, Joanna

    2008-05-01

    Mesothelial cells are an integral part of the peritoneum and play an important role in maintaining its structural and functional properties. In the recent years a number of studies on mesothelial cells have been performed to evaluate the localization, secretional properties and the ability of regeneration and transdifferentiation of these cells. They are also involved in the repair of the peritoneum damage following surgery or peritonitis. Mesothelial cells produce several cytokines, growth factors and extracellular matrix components, possessing anti-inflammatory and immunomodulatory properties. Because of their plasticity, these cells are able to form a new cell type like fibroblast, endothelial and smooth muscle cell, chondrocyte, osteoblast, adipocyte or neuron. The first step involves mesothelial cell transdifferentiation into progenitor cells with the capacity of further differentiation. In this paper the current knowledge concerning the mesothelial cell differentiation and transplantation has been reviewed. Own mesothelial cells of a patient are used in transplantation. They are sampled, cultured in vitro and then they can be used in the prevention and treatment of post-operative abdominal adhesions, incisional hernias, repair of peritoneal membrane of patients on long-term peritoneal dialysis, the prevention of ischemic myocardial damage, nerve regeneration and genetically modified recombinant protein secretion. Inevitably, more potential applications of transplanted mesothelial cell will be available over the next few years.

  3. Cell Culture Made Easy.

    ERIC Educational Resources Information Center

    Dye, Frank J.

    1985-01-01

    Outlines steps to generate cell samples for observation and experimentation. The procedures (which use ordinary laboratory equipment) will establish a short-term primary culture of normal mammalian cells. Information on culture vessels and cell division and a list of questions to generate student interest and involvement in the topics are…

  4. Mammalian Cell Culture Simplified.

    ERIC Educational Resources Information Center

    Moss, Robert; Solomon, Sondra

    1991-01-01

    A tissue culture experiment that does not require elaborate equipment and that can be used to teach sterile technique, the principles of animal cell line maintenance, and the concept of cell growth curves is described. The differences between cancerous and normal cells can be highlighted. The procedure is included. (KR)

  5. Photoelectrochemical Solar Cells.

    ERIC Educational Resources Information Center

    McDevitt, John T.

    1984-01-01

    This introduction to photoelectrochemical (PEC) cells reviews topics pertaining to solar energy conversion and demonstrates the ease with which a working PEC cell can be prepared with n-type silicon as the photoanode and a platinum counter electrode (both immersed in ethanolic ferrocene/ferricenium solutions). Experiments using the cell are…

  6. Biomarkers of cell senescence

    DOEpatents

    Dirmi, Goberdhan P.; Campisi, Judith; Peacocke, Monica

    1996-01-01

    The present invention provides a biomarker system for the in vivo and in vitro assessment of cell senescence. In the method of the present invention, .beta.-galactosidase activity is utilized as a means by which cell senescence may be assessed either in in vitro cell cultures or in vivo.

  7. Biomarkers of cell senescence

    DOEpatents

    Dimri, Goberdhan P.; Campisi, Judith; Peacocke, Monica

    1998-01-01

    The present invention provides a biomarker system for the in vivo and in vitro assessment of cell senescence. In the method of the present invention, .beta.-galactosidase activity is utilized as a means by which cell senescence may be assessed either in vitro cell cultures or in vivo.

  8. Lithium Cell Reactions.

    DTIC Science & Technology

    1985-02-01

    Page 1. INVESTIGATION OF CHEMICAL, ELECTROCHEMICAL AND PARASITIC REACTIONS IN LITHIUM - THIONYL CHLORIDE CELLS ....... ................. 1 1.1 INTRODUCTION...OF LITHIUM - THIONYL CHLORIDE CELLS. ................ 56 1.4.1 Carbon Limited Overdischarge...............56 1.4.1.1 Background... LITHIUM THIONYL - CHLORIDE CELLS. .. ............ ...... 101 1.5.1 Background. ....... ............ .... 101 1.5.2 Microphotography

  9. Adventures with Cell Phones

    ERIC Educational Resources Information Center

    Kolb, Liz

    2011-01-01

    Teachers are finding creative ways to turn the basic cell phone from a digital distraction into a versatile learning tool. In this article, the author explains why cell phones are important in learning and suggests rather than banning them that they be integrated into learning. She presents activities that can be done on a basic cell phone with a…

  10. B cells flying solo.

    PubMed

    Groom, Joanna; Mackay, Fabienne

    2008-01-01

    Systemic autoimmunity such as systemic lupus erythematosus (SLE) is associated with the loss of B-cell tolerance, B-cell dysregulation and autoantibody production. While some autoantibodies may contribute to the pathology seen with SLE, numerous studies have shown that dysregulation of T-cell function is another critical aspect driving disease. The positive results obtained in clinical trials using T-cell- or B-cell-specific treatments have suggested that cooperation between T and B cells probably underlies disease progression in many patients. A similar cooperative mechanism seemed to explain SLE developing in mice overexpressing the B-cell-activating factor from the tumor necrosis factor family (BAFF). However, surprisingly, T-cell-deficient BAFF transgenic (Tg) mice develop SLE similar to T-cell-sufficient BAFF Tg mice, and the disease was linked to innate activation of B cells and production of proinflammatory autoantibody isotypes. In conclusion, dysregulated innate activation of B cells alone can drive disease independently of T cells, and as such this aspect represents a new pathogenic mechanism in autoimmunity.

  11. Biomarkers of cell senescence

    DOEpatents

    Dirmi, G.P.; Campisi, J.; Peacocke, M.

    1996-02-13

    The present invention provides a biomarker system for the in vivo and in vitro assessment of cell senescence. In the method of the present invention, {beta}-galactosidase activity is utilized as a means by which cell senescence may be assessed either in in vitro cell cultures or in vivo. 1 fig.

  12. Biomarkers of cell senescence

    DOEpatents

    Dimri, G.P.; Campisi, J.; Peacocke, M.

    1998-08-18

    The present invention provides a biomarker system for the in vivo and in vitro assessment of cell senescence. In the method of the present invention, {beta}-galactosidase activity is utilized as a means by which cell senescence may be assessed either in vitro cell cultures or in vivo. 1 fig.

  13. Rapidly refuelable fuel cell

    DOEpatents

    Joy, Richard W.

    1983-01-01

    This invention is directed to a metal-air fuel cell where the consumable metal anode is movably positioned in the cell and an expandable enclosure, or bladder, is used to press the anode into contact with separating spacers between the cell electrodes. The bladder may be depressurized to allow replacement of the anode when consumed.

  14. Cell Culture Made Easy.

    ERIC Educational Resources Information Center

    Dye, Frank J.

    1985-01-01

    Outlines steps to generate cell samples for observation and experimentation. The procedures (which use ordinary laboratory equipment) will establish a short-term primary culture of normal mammalian cells. Information on culture vessels and cell division and a list of questions to generate student interest and involvement in the topics are…

  15. Mammalian Cell Culture Simplified.

    ERIC Educational Resources Information Center

    Moss, Robert; Solomon, Sondra

    1991-01-01

    A tissue culture experiment that does not require elaborate equipment and that can be used to teach sterile technique, the principles of animal cell line maintenance, and the concept of cell growth curves is described. The differences between cancerous and normal cells can be highlighted. The procedure is included. (KR)

  16. Cell-cell connection to cardiac disease.

    PubMed

    Sheikh, Farah; Ross, Robert S; Chen, Ju

    2009-08-01

    Intercalated disks (ICDs) are highly organized cell-cell adhesion structures, which connect cardiomyocytes to one another. They are composed of three major complexes: desmosomes, fascia adherens, and gap junctions. Desmosomes and fascia adherens junction are necessary for mechanically coupling and reinforcing cardiomyocytes, whereas gap junctions are essential for rapid electrical transmission between cells. Because human genetics and mouse models have revealed that mutations and/or deficiencies in various ICD components can lead to cardiomyopathies and arrhythmias, considerable attention has focused on the biologic function of the ICD. This review will discuss recent scientific developments related to the ICD and focus on its role in regulating cardiac muscle structure, signaling, and disease.

  17. Mesangial cells initiate compensatory tubular cell hypertrophy.

    PubMed

    Sinuani, I; Beberashvili, I; Averbukh, Z; Cohn, M; Gitelman, I; Weissgarten, J

    2010-01-01

    Unilateral nephrectomy results in compensatory renal growth, in which both the size and the functional capacity of the remaining kidney are increased. The functional adaptation to the removal of the contralateral kidney consists mostly of an increase in the glomerular filtration rate of the remaining kidney, and hypertrophy of cells comprising the nephron, mainly of the proximal tubular cells. Although the phenomenon of single kidney hypertrophy has been known for the past thousand years and despite intensive research over the past century, the mechanism of this process still remains unclear. The present article reviews the role of mesangial cells in compensatory renal hypertrophy. 2010 S. Karger AG, Basel.

  18. Molecular Mechanisms of HTLV-1 Cell-to-Cell Transmission

    PubMed Central

    Gross, Christine; Thoma-Kress, Andrea K.

    2016-01-01

    The tumorvirus human T-cell lymphotropic virus type 1 (HTLV-1), a member of the delta-retrovirus family, is transmitted via cell-containing body fluids such as blood products, semen, and breast milk. In vivo, HTLV-1 preferentially infects CD4+ T-cells, and to a lesser extent, CD8+ T-cells, dendritic cells, and monocytes. Efficient infection of CD4+ T-cells requires cell-cell contacts while cell-free virus transmission is inefficient. Two types of cell-cell contacts have been described to be critical for HTLV-1 transmission, tight junctions and cellular conduits. Further, two non-exclusive mechanisms of virus transmission at cell-cell contacts have been proposed: (1) polarized budding of HTLV-1 into synaptic clefts; and (2) cell surface transfer of viral biofilms at virological synapses. In contrast to CD4+ T-cells, dendritic cells can be infected cell-free and, to a greater extent, via viral biofilms in vitro. Cell-to-cell transmission of HTLV-1 requires a coordinated action of steps in the virus infectious cycle with events in the cell-cell adhesion process; therefore, virus propagation from cell-to-cell depends on specific interactions between cellular and viral proteins. Here, we review the molecular mechanisms of HTLV-1 transmission with a focus on the HTLV-1-encoded proteins Tax and p8, their impact on host cell factors mediating cell-cell contacts, cytoskeletal remodeling, and thus, virus propagation. PMID:27005656

  19. Stochastic elimination of cancer cells.

    PubMed Central

    Michor, Franziska; Nowak, Martin A; Frank, Steven A; Iwasa, Yoh

    2003-01-01

    Tissues of multicellular organisms consist of stem cells and differentiated cells. Stem cells divide to produce new stem cells or differentiated cells. Differentiated cells divide to produce new differentiated cells. We show that such a tissue design can reduce the rate of fixation of mutations that increase the net proliferation rate of cells. It has, however, no consequence for the rate of fixation of neutral mutations. We calculate the optimum relative abundance of stem cells that minimizes the rate of generating cancer cells. There is a critical fraction of stem cell divisions that is required for a stochastic elimination ('wash out') of cancer cells. PMID:14561289

  20. Killer cells in atherosclerosis.

    PubMed

    Kyaw, Tin; Tipping, Peter; Toh, Ban-Hock; Bobik, Alex

    2017-05-05

    Cytotoxic lymphocytes (killer cells) play a critical role in host defence mechanisms, protecting against infections and in tumour surveillance. They can also exert detrimental effects in chronic inflammatory disorders and in autoimmune diseases. Tissue cell death and necrosis are prominent features of advanced atherosclerotic lesions including vulnerable/unstable lesions which are largely responsible for most heart attacks and strokes. Evidence for accumulation of killer cells in both human and mouse lesions together with their cytotoxic potential strongly suggest that these cells contribute to cell death and necrosis in lesions leading to vulnerable plaque development and potentially plaque rupture. Killer cells can be divided into two groups, adaptive and innate immune cells depending on whether they require antigen presentation for activation. Activated killer cells detect damaged or stressed cells and kill by cytotoxic mechanisms that include perforin, granzymes, TRAIL or FasL and in some cases TNF-α. In this review, we examine current knowledge on killer cells in atherosclerosis, including CD8 T cells, CD28- CD4 T cells, natural killer cells and γδ-T cells, mechanisms responsible for their activation, their migration to developing lesions and effector functions. We also discuss pharmacological strategies to prevent their deleterious vascular effects by preventing/limiting their cytotoxic effects within atherosclerotic lesions as well as potential immunomodulatory therapies that might better target lesion-resident killer cells, to minimise any compromise of the immune system, which could result in increased susceptibility to infections and reductions in tumour surveillance. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Cell-ECM traction force modulates endogenous tension at cell-cell contacts.

    PubMed

    Maruthamuthu, Venkat; Sabass, Benedikt; Schwarz, Ulrich S; Gardel, Margaret L

    2011-03-22

    Cells in tissues are mechanically coupled both to the ECM and neighboring cells, but the coordination and interdependency of forces sustained at cell-ECM and cell-cell adhesions are unknown. In this paper, we demonstrate that the endogenous force sustained at the cell-cell contact between a pair of epithelial cells is approximately 100 nN, directed perpendicular to the cell-cell interface and concentrated at the contact edges. This force is stably maintained over time despite significant fluctuations in cell-cell contact length and cell morphology. A direct relationship between the total cellular traction force on the ECM and the endogenous cell-cell force exists, indicating that the cell-cell tension is a constant fraction of the cell-ECM traction. Thus, modulation of ECM properties that impact cell-ECM traction alters cell-cell tension. Finally, we show in a minimal model of a tissue that all cells experience similar forces from the surrounding microenvironment, despite differences in the extent of cell-ECM and cell-cell adhesion. This interdependence of cell-cell and cell-ECM forces has significant implications for the maintenance of the mechanical integrity of tissues, mechanotransduction, and tumor mechanobiology.

  2. [Cell transplant and regenerative stem cell therapy].

    PubMed

    Prosper, F

    2008-01-01

    The derivation of the first human embryonic stem cell lines as well as the notion of the unexpected plasticity and potential of the adult stem cells has significantly impacted the biomedical research. Many of the tissues long believe to lack any regenerative capacity has demonstrated otherwise. Patients alike physicians expectations for treatment of incurable diseases have also fuelled this field and in occasions have led to unrealistic expectations. In the next pages I review some of the tissue specific stem cells that have been used either in preclinical models or even in clinical research. Despite the effort of numerous investigators, more questions that answers remain in the field of cell therapy and only careful and independent -not biased- research will allow us to translate some of this findings into clinical application.

  3. Skeletal muscle satellite cells

    NASA Technical Reports Server (NTRS)

    Schultz, E.; McCormick, K. M.

    1994-01-01

    Evidence now suggests that satellite cells constitute a class of myogenic cells that differ distinctly from other embryonic myoblasts. Satellite cells arise from somites and first appear as a distinct myoblast type well before birth. Satellite cells from different muscles cannot be functionally distinguished from one another and are able to provide nuclei to all fibers without regard to phenotype. Thus, it is difficult to ascribe any significant function to establishing or stabilizing fiber type, even during regeneration. Within a muscle, satellite cells exhibit marked heterogeneity with respect to their proliferative behavior. The satellite cell population on a fiber can be partitioned into those that function as stem cells and those which are readily available for fusion. Recent studies have shown that the cells are not simply spindle shaped, but are very diverse in their morphology and have multiple branches emanating from the poles of the cells. This finding is consistent with other studies indicating that the cells have the capacity for extensive migration within, and perhaps between, muscles. Complexity of cell shape usually reflects increased cytoplasmic volume and organelles including a well developed Golgi, and is usually associated with growing postnatal muscle or muscles undergoing some form of induced adaptive change or repair. The appearance of activated satellite cells suggests some function of the cells in the adaptive process through elaboration and secretion of a product. Significant advances have been made in determining the potential secretion products that satellite cells make. The manner in which satellite cell proliferative and fusion behavior is controlled has also been studied. There seems to be little doubt that cellcell coupling is not how satellite cells and myofibers communicate. Rather satellite cell regulation is through a number of potential growth factors that arise from a number of sources. Critical to the understanding of this form

  4. Cell and gene therapy.

    PubMed

    Rao, Rajesh C; Zacks, David N

    2014-01-01

    Replacement or repair of a dysfunctional gene combined with promoting cell survival is a two-pronged approach that addresses an unmet need in the therapy of retinal degenerative diseases. In this chapter, we discuss various strategies toward achieving both goals: transplantation of wild-type cells to replace degenerating cells and to rescue gene function, sequential gene and cell therapy, and in vivo reprogramming of rods to cones. These approaches highlight cutting-edge advances in cell and gene therapy, and cellular lineage conversion in order to devise new therapies for various retinal degenerative diseases.

  5. Making Ultrathin Solar Cells

    NASA Technical Reports Server (NTRS)

    Cogan, George W.; Christel, Lee A.; Merchant, J. Thomas; Gibbons, James F.

    1991-01-01

    Process produces extremely thin silicon solar cells - only 50 micrometers or less in thickness. Electrons and holes have less opportunity to recombine before collected at cell surfaces. Efficiency higher and because volume of silicon small, less chance of radiation damage in new cells. Initial steps carried out at normal thickness to reduce breakage and avoid extra cost of special handling. Cells then thinned mechanically and chemically. Final cell includes reflective layer on back surface. Layer bounces unabsorbed light back into bulk silicon so it absorbs and produces useful electrical output.

  6. Nail stem cells.

    PubMed

    Sellheyer, Klaus

    2013-03-01

    Our knowledge on stem cells of the hair follicle has increased exponentially after the bulge was characterized as the stem cell niche two decades ago. In contrast, little is known about stem cells in the nail unit. Whereas hair follicles are plentiful and easy to access, the human body has only twenty nails and they are rarely biopsied. Therefore, examining fetal material offers unique advantages. In the following mini-review, our current knowledge on nail stem cells is summarized and analogies to the hair follicle stem cells are drawn.

  7. The microbial cell cycle

    SciTech Connect

    Nurse, P.; Streiblova, E.

    1984-01-01

    This book concentrates on the major problems of cell cycle control in microorganisms. A wide variety of microorganisms, ranging from bacteria and yeasts to hyphal fungi, algae, and ciliates are analyzed, with emphasis on the basic similarities among the organisms. Different ways of looking at cell cycle control which emphasize aspects of the problem such as circadian rhythms, limit cycle oscillators, and cell size models, are considered. New approaches such as the study of cell cycle mutants, and cloning of cell cycle control genes are also presented.

  8. Transparent ultraviolet photovoltaic cells.

    PubMed

    Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

    2016-02-15

    Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future.

  9. Fuel Cell Handbook update

    SciTech Connect

    Owens, W.R.; Hirschenhofer, J.H.; Engleman, R.R. Jr.; Stauffer, D.B.

    1993-11-01

    The objective of this work was to update the 1988 version of DOE`s Fuel Cell Handbook. Significant developments in the various fuel cell technologies required revisions to reflect state-of-the-art configurations and performance. The theoretical presentation was refined in order to make the handbook more useful to both the casual reader and fuel cell or systems analyst. In order to further emphasize the practical application of fuel cell technologies, the system integration information was expanded. In addition, practical elements, such as suggestions and guidelines to approximate fuel cell performance, were provided.

  10. Stem Cells and Aging.

    PubMed

    Koliakos, George

    2017-02-01

    The article is a presentation at the 4th Conference of ESAAM, which took place on October 30-31, 2015, in Athens, Greece. Its purpose was not to cover all aspects of cellular aging but to share with the audience of the Conference, in a 15-minute presentation, current knowledge about the rejuvenating and repairing somatic stem cells that are distinct from other stem cell types (such as embryonic or induced pluripotent stem cells), emphasize that our body in old age cannot take advantage of these rejuvenating cells, and provide some examples of novel experimental stem cell applications in the field of rejuvenation and antiaging biomedical research.

  11. Making Ultrathin Solar Cells

    NASA Technical Reports Server (NTRS)

    Cogan, George W.; Christel, Lee A.; Merchant, J. Thomas; Gibbons, James F.

    1991-01-01

    Process produces extremely thin silicon solar cells - only 50 micrometers or less in thickness. Electrons and holes have less opportunity to recombine before collected at cell surfaces. Efficiency higher and because volume of silicon small, less chance of radiation damage in new cells. Initial steps carried out at normal thickness to reduce breakage and avoid extra cost of special handling. Cells then thinned mechanically and chemically. Final cell includes reflective layer on back surface. Layer bounces unabsorbed light back into bulk silicon so it absorbs and produces useful electrical output.

  12. Mast cell activation disorders.

    PubMed

    Akin, Cem

    2014-01-01

    Disorders associated with mast cell activation range from relatively common IgE-mediated disease and chronic urticaria to rarer conditions such as mastocytosis or monoclonal mast cell activation disorder. Mast cell activation disorders can be mechanistically classified into primary (associated with abnormal production of mast cells that carry pathologic markers of clonality), secondary (normal mast cells activated in reaction to a microenvironmental trigger), and idiopathic (no etiology is found). Clinical presentations, diagnostic criteria as well as general principles of a stepwise therapy approach are discussed.

  13. Cell-cell and intracellular lactate shuttles.

    PubMed

    Brooks, George A

    2009-12-01

    Once thought to be the consequence of oxygen lack in contracting skeletal muscle, the glycolytic product lactate is formed and utilized continuously in diverse cells under fully aerobic conditions. 'Cell-cell' and 'intracellular lactate shuttle' concepts describe the roles of lactate in delivery of oxidative and gluconeogenic substrates as well as in cell signalling. Examples of the cell-cell shuttles include lactate exchanges between between white-glycolytic and red-oxidative fibres within a working muscle bed, and between working skeletal muscle and heart, brain, liver and kidneys. Examples of intracellular lactate shuttles include lactate uptake by mitochondria and pyruvate for lactate exchange in peroxisomes. Lactate for pyruvate exchanges affect cell redox state, and by itself lactate is a ROS generator. In vivo, lactate is a preferred substrate and high blood lactate levels down-regulate the use of glucose and free fatty acids (FFA). As well, lactate binding may affect metabolic regulation, for instance binding to G-protein receptors in adipocytes inhibiting lipolysis, and thus decreasing plasma FFA availability. In vitro lactate accumulation upregulates expression of MCT1 and genes coding for other components of the mitochondrial reticulum in skeletal muscle. The mitochondrial reticulum in muscle and mitochondrial networks in other aerobic tissues function to establish concentration and proton gradients necessary for cells with high mitochondrial densities to oxidize lactate. The presence of lactate shuttles gives rise to the realization that glycolytic and oxidative pathways should be viewed as linked, as opposed to alternative, processes, because lactate, the product of one pathway, is the substrate for the other.

  14. Fuel Cell/Electrochemical Cell Voltage Monitor

    NASA Technical Reports Server (NTRS)

    Vasquez, Arturo

    2012-01-01

    A concept has been developed for a new fuel cell individual-cell-voltage monitor that can be directly connected to a multi-cell fuel cell stack for direct substack power provisioning. It can also provide voltage isolation for applications in high-voltage fuel cell stacks. The technology consists of basic modules, each with an 8- to 16-cell input electrical measurement connection port. For each basic module, a power input connection would be provided for direct connection to a sub-stack of fuel cells in series within the larger stack. This power connection would allow for module power to be available in the range of 9-15 volts DC. The relatively low voltage differences that the module would encounter from the input electrical measurement connection port, coupled with the fact that the module's operating power is supplied by the same substack voltage input (and so will be at similar voltage), provides for elimination of high-commonmode voltage issues within each module. Within each module, there would be options for analog-to-digital conversion and data transfer schemes. Each module would also include a data-output/communication port. Each of these ports would be required to be either non-electrical (e.g., optically isolated) or electrically isolated. This is necessary to account for the fact that the plurality of modules attached to the stack will normally be at a range of voltages approaching the full range of the fuel cell stack operating voltages. A communications/ data bus could interface with the several basic modules. Options have been identified for command inputs from the spacecraft vehicle controller, and for output-status/data feeds to the vehicle.

  15. Stress and stem cells.

    PubMed

    Tower, John

    2012-01-01

    The unique properties and functions of stem cells make them particularly susceptible to stresses and also lead to their regulation by stress. Stem cell division must respond to the demand to replenish cells during normal tissue turnover as well as in response to damage. Oxidative stress, mechanical stress, growth factors, and cytokines signal stem cell division and differentiation. Many of the conserved pathways regulating stem cell self-renewal and differentiation are also stress-response pathways. The long life span and division potential of stem cells create a propensity for transformation (cancer) and specific stress responses such as apoptosis and senescence act as antitumor mechanisms. Quiescence regulated by CDK inhibitors and a hypoxic niche regulated by FOXO transcription factor function to reduce stress for several types of stem cells to facilitate long-term maintenance. Aging is a particularly relevant stress for stem cells, because repeated demands on stem cell function over the life span can have cumulative cell-autonomous effects including epigenetic dysregulation, mutations, and telomere erosion. In addition, aging of the organism impairs function of the stem cell niche and systemic signals, including chronic inflammation and oxidative stress.

  16. Parameterization of solar cells

    NASA Technical Reports Server (NTRS)

    Appelbaum, J.; Chait, A.; Thompson, D.

    1992-01-01

    The aggregation (sorting) of the individual solar cells into an array is commonly based on a single operating point on the current-voltage (I-V) characteristic curve. An alternative approach for cell performance prediction and cell screening is provided by modeling the cell using an equivalent electrical circuit, in which the parameters involved are related to the physical phenomena in the device. These analytical models may be represented by a double exponential I-V characteristic with seven parameters, by a double exponential model with five parameters, or by a single exponential equation with four or five parameters. In this article we address issues concerning methodologies for the determination of solar cell parameters based on measured data points of the I-V characteristic, and introduce a procedure for screening of solar cells for arrays. We show that common curve fitting techniques, e.g., least squares, may produce many combinations of parameter values while maintaining a good fit between the fitted and measured I-V characteristics of the cell. Therefore, techniques relying on curve fitting criteria alone cannot be directly used for cell parameterization. We propose a consistent procedure which takes into account the entire set of parameter values for a batch of cells. This procedure is based on a definition of a mean cell representing the batch, and takes into account the relative contribution of each parameter to the overall goodness of fit. The procedure is demonstrated on a batch of 50 silicon cells for Space Station Freedom.

  17. PURE CULTURES OF CELLS

    PubMed Central

    Carrel, Alexis

    1912-01-01

    In experiment I a group of ameboid cells was isolated from a culture of cardiac muscle sixty-three days old, and cultivated in plasma. After several passages, they formed a dense tissue from which ameboid cells radiated. The culture was divided into two parts. The part cultivated in plasma alone kept its morphological characters and continued to produce ameboid cells. The part cultivated upon silk in plasma became modified; the cells lost their ameboid characters, and were transformed into large elongated cells which were united in chains, or interlaced to form a network. In experiment II the round cells taken from a culture of connective tissue seventy-four days old multiplied rapidly. They transformed themselves into elongated cells and produced, after a few passages, a mass of dense connective tissue. From the tissue a large number of elongated cells were constantly growing. In both experiments the tissues originated from the ameboid or round cells extirpated from cultures that were sixty-three and seventy-four days old respectively. These cultures were still growing actively thirty and forty days later; that is, more than one hundred days after the extirpation of the original fragments from the organism. These experiments show that from old cultures it is possible to isolate and propagate cells that belong to a definite type. A tissue, formed by a pure strain of cells, can be obtained in this way, and this new method may be of value in cytological investigations. PMID:19867562

  18. Islet cell development.

    PubMed

    Rojas, Anabel; Khoo, Adrian; Tejedo, Juan R; Bedoya, Francisco J; Soria, Bernat; Martín, Franz

    2010-01-01

    Over the last years, there has been great success in driving stem cells toward insulin-expressing cells. However, the protocols developed to date have some limitations, such as low reliability and low insulin production. The most successful protocols used for generation of insulin-producing cells from stem cells mimic in vitro pancreatic organogenesis by directing the stem cells through stages that resemble several pancreatic developmental stages. Islet cell fate is coordinated by a complex network of inductive signals and regulatory transcription factors that, in a combinatorial way, determine pancreatic organ specification, differentiation, growth, and lineage. Together, these signals and factors direct the progression from multipotent progenitor cells to mature pancreatic cells. Later in development and adult life, several of these factors also contribute to maintain the differentiated phenotype of islet cells. A detailed understanding of the processes that operate in the pancreas during embryogenesis will help us to develop a suitable source of cells for diabetes therapy. In this chapter, we will discuss the main transcription factors involved in pancreas specification and beta-cell formation.

  19. Programmed cell death.

    PubMed

    Samuilov, V D; Oleskin, A V; Lagunova, E M

    2000-08-01

    This paper reviews data on programmed cell death (apoptosis) in animals and plants. Necrosis is a pathological scenario of cell death, which entails an inflammatory response in animal tissues. Apoptosis results in the disintegration of animal/plant cells into membrane vesicles enclosing the intracellular content, which are thereupon engulfed by adjacent or specialized cells (phagocytes) in animals. Plants lack such specialized cells, and plant cell walls prevent phagocytosis. The paper considers the main molecular mechanisms of apoptosis in animals and the pathways of activation of caspases, evolutionarily conserved cysteine proteases. A self-contained section concerns itself with the process of programmed cell death (PCD) in microorganisms including: 1) cell death in the myxomycete Dictyostelium discoideum and the parasitic flagellate Trypanosoma cruzi; 2) PCD in genetically manipulated yeast expressing the proapoptotic Bax and Bak proteins; 3) the death of a part of a prokaryotic cell population upon the depletion of nutrient resources or under stress; 4) the elimination of cells after a loss of a plasmid encoding a stable cytotoxic agent in combination with an unstable antidote; and 5) PCD in phage-infected bacterial cells.

  20. Freezing human ES cells.

    PubMed

    Trish, Erin; Dimos, John; Eggan, Kevin

    2006-10-12

    Here we demonstrate how our lab freezes HuES human embryonic stem cell lines. A healthy, exponentially expanding culture is washed with PBS to remove residual media that could otherwise quench the Trypsin reaction. Warmed 0.05% Trypsin-EDTA is then added to cover the cells, and the plate allowed to incubate for up to 5 mins at room temperature. During this time cells can be observed rounding, and colonies lifting off the plate surface. Gentle repeated pipetting will remove cells and colonies from the plate surface. Trypsinized cells are placed in a standard conical tube containing pre-warmed hES cell media to quench remaining trypsin, and then spun. Cells are resuspended growth media at a concentration of approximately one million cells in one mL of media, a concentration such that one frozen aliquot is sufficient to resurrect a culture on a 10 cm plate. After cells are adequately resuspended, ice cold freezing media is added at equal volume. Cell suspensions are mixed thoroughly, aliquoted into freezing vials, and allowed to slowly freeze to -80 C over 24 hours. Frozen cells can then moved to the vapor phase of liquid nitrogen for long term storage, or remain at -80 for approximately six months.

  1. Chlorophyll sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Glenn, D. F.

    1984-06-01

    The photovoltaic properties of the green plant pigment chlorophyll-a (Chl-a) were investigated in photoelectrochemical and solid state solar cells. Both types of cells utilized a thin film of Chl-a electro-deposited on a SnO2 optically transparent electrode. Solid state cells were fabricated by vapor depositing a thin layer of metal on top of the Chl-A to produce a SnO2/Chl-a/metal sandwich cell. Photoelectrochemical cells were assembled by immersing the SnO2/Chl-a electrode in an aqueous electrolyte solution along with a counter electrode. Both types of Chl-a cells were generally characterized by a strong dependence of he photoactivity on the other cell components and a surprisingly large photovoltage. Photoelectrochemical cells of SnO2/l-a/aq.AlCl3 were seen to produce photovoltages as high as 1.1 V and photocurrents of 1.1 micro A/sq cm while a solid state cell of SnO2/Chl-a/Al could produce 1.4 V and an initial photocurrent of 200 micro A/sq cm. This photoactivity was strongly time dependent in both configurations. Despite this fact, these cells are the most powerful Chl-a sensitized solar cells yet reported.

  2. Hematopoietic Stem Cells Therapies.

    PubMed

    Chivu-Economescu, Mihaela; Rubach, Martin

    2017-01-01

    Stem cell-based therapies are recognized as a new way to treat various diseases and injuries, with a wide range of health benefits. The goal is to heal or replace diseased or destroyed organs or body parts with healthy new cells provided by stem cell transplantation. The current practical form of stem cell therapy is the hematopoietic stem cells transplant applied for the treatment of hematological disorders. There are over 2100 clinical studies in progress concerning hematopoietic stem cell therapies. All of them are using hematopoietic stem cells to treat various diseases like: cancers, leukemia, lymphoma, cardiac failure, neural disorders, auto-immune diseases, immunodeficiency, metabolic or genetic disorders. Several challenges are to be addressed prior to developing and applying large scale cell therapies: 1) to explain and control the mechanisms of differentiation and development toward a specific cell type needed to treat the disease, 2) to obtain a sufficient number of desired cell type for transplantation, 3) to overcome the immune rejection and 4) to show that transplanted cells fulfill their normal functions in vivo after transplants.

  3. Stress and stem cells

    PubMed Central

    Tower, John

    2013-01-01

    The unique properties and functions of stem cells make them particularly susceptible to stresses and also lead to their regulation by stress. Stem cell division must respond to the demand to replenish cells during normal tissue turnover as well as in response to damage. Oxidative stress, mechanical stress, growth factors, and cytokines signal stem cell division and differentiation. Many of the conserved pathways regulating stem cell self-renewal and differentiation are also stress-response pathways. The long life span and division potential of stem cells create a propensity for transformation (cancer) and specific stress responses such as apoptosis and senescence act as antitumor mechanisms. Quiescence regulated by CDK inhibitors and a hypoxic niche regulated by FOXO transcription factor function to reduce stress for several types of stem cells to facilitate long-term maintenance. Aging is a particularly relevant stress for stem cells, because repeated demands on stem cell function over the life span can have cumulative cell-autonomous effects including epigenetic dysregulation, mutations, and telomere erosion. In addition, aging of the organism impairs function of the stem cell niche and systemic signals, including chronic inflammation and oxidative stress. PMID:23799624

  4. Cell biology. Metabolic control of cell death.

    PubMed

    Green, Douglas R; Galluzzi, Lorenzo; Kroemer, Guido

    2014-09-19

    Beyond their contribution to basic metabolism, the major cellular organelles, in particular mitochondria, can determine whether cells respond to stress in an adaptive or suicidal manner. Thus, mitochondria can continuously adapt their shape to changing bioenergetic demands as they are subjected to quality control by autophagy, or they can undergo a lethal permeabilization process that initiates apoptosis. Along similar lines, multiple proteins involved in metabolic circuitries, including oxidative phosphorylation and transport of metabolites across membranes, may participate in the regulated or catastrophic dismantling of organelles. Many factors that were initially characterized as cell death regulators are now known to physically or functionally interact with metabolic enzymes. Thus, several metabolic cues regulate the propensity of cells to activate self-destructive programs, in part by acting on nutrient sensors. This suggests the existence of "metabolic checkpoints" that dictate cell fate in response to metabolic fluctuations. Here, we discuss recent insights into the intersection between metabolism and cell death regulation that have major implications for the comprehension and manipulation of unwarranted cell loss.

  5. Biosensing with cell phones.

    PubMed

    Preechaburana, Pakorn; Suska, Anke; Filippini, Daniel

    2014-07-01

    Continued progress in cell-phone devices has made them powerful mobile computers, equipped with sophisticated, permanent physical sensors embedded as the default configuration. By contrast, the incorporation of permanent biosensors in cell-phone units has been prevented by the multivocal nature of the stimuli and the reactions involved in biosensing and chemical sensing. Biosensing with cell phones entails the complementation of biosensing devices with the physical sensors and communication and processing capabilities of modern cell phones. Biosensing, chemical-sensing, environmental-sensing, and diagnostic capabilities would thus be supported and run on the residual capacity of existing cell-phone infrastructure. The technologies necessary to materialize such a scenario have emerged in different fields and applications. This article addresses the progress on cell-phone biosensing, the specific compromises, and the blend of technologies required to craft biosensing on cell phones.

  6. Myosins in cell junctions

    PubMed Central

    Liu, Katy C.; Cheney, Richard E.

    2012-01-01

    The development of cell-cell junctions was a fundamental step in metazoan evolution, and human health depends on the formation and function of cell junctions. Although it has long been known that actin and conventional myosin have important roles in cell junctions, research has begun to reveal the specific functions of the different forms of conventional myosin. Exciting new data also reveals that a growing number of unconventional myosins have important roles in cell junctions. Experiments showing that cell junctions act as mechanosensors have also provided new impetus to understand the functions of myosins and the forces they exert. In this review we will summarize recent developments on the roles of myosins in cell junctions. PMID:22954512

  7. Overview of Cell Synchronization.

    PubMed

    Banfalvi, Gaspar

    2017-01-01

    The widespread interest in cell synchronization is maintained by the studies of control mechanism involved in cell cycle regulation. During the synchronization distinct subpopulations of cells are obtained representing different stages of the cell cycle. These subpopulations are then used to study regulatory mechanisms of the cycle at the level of macromolecular biosynthesis (DNA synthesis, gene expression, protein synthesis), protein phosphorylation, development of new drugs, etc. Although several synchronization methods have been described, it is of general interest that scientists get a compilation and an updated view of these synchronization techniques. This introductory chapter summarizes: (1) the basic concepts and principal criteria of cell cycle synchronizations, (2) the most frequently used synchronization methods, such as physical fractionation (flow cytometry, dielectrophoresis, cytofluorometric purification), chemical blockade, (3) synchronization of embryonic cells, (4) synchronization at low temperature, (5) comparison of cell synchrony techniques, (6) synchronization of unicellular organisms, and (7) the effect of synchronization on transfection.

  8. Cell sorting apparatus

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Rembaum, Alan (Inventor); Molday, Robert S. (Inventor)

    1980-01-01

    Polymeric functional microspheres containing metal or metal compounds are formed by addition polymerization of a covalently bondable olefinic monomer such as hydroxyethylmethacrylate in the presence of finely divided metal or metal oxide particles, such as iron, gold, platinum or magnetite, which are embedded in the resulting microspheres. The microspheres can be covalently bonded to chemotherapeutic agents, antibodies, or other proteins providing a means for labeling or separating labeled cells. Labeled cells or microspheres can be concentrated at a specific body location such as in the vicinity of a malignant tumor by applying a magnetic field to the location and then introducing the magnetically attractable microspheres or cells into the circulatory system of the subject. Labeled cells can be separated from a cell mixture by applying a predetermined magnetic field to a tube in which the mixture is flowing. After collection of the labeled cells, the magnetic field is discontinued and the labeled sub-cell population recovered.

  9. Intraoperative Stem Cell Therapy

    PubMed Central

    Coelho, Mónica Beato; Cabral, Joaquim M.S.; Karp, Jeffrey M.

    2013-01-01

    Stem cells hold significant promise for regeneration of tissue defects and disease-modifying therapies. Although numerous promising stem cell approaches are advancing in clinical trials, intraoperative stem cell therapies offer more immediate hope by integrating an autologous cell source with a well-established surgical intervention in a single procedure. Herein, the major developments in intraoperative stem cell approaches, from in vivo models to clinical studies, are reviewed, and the potential regenerative mechanisms and the roles of different cell populations in the regeneration process are discussed. Although intraoperative stem cell therapies have been shown to be safe and effective for several indications, there are still critical challenges to be tackled prior to adoption into the standard surgical armamentarium. PMID:22809140

  10. Cell viability assays: introduction.

    PubMed

    Stoddart, Martin J

    2011-01-01

    The measurement of cell viability plays a fundamental role in all forms of cell culture. Sometimes it is the main purpose of the experiment, such as in toxicity assays. Alternatively, cell viability can be used to -correlate cell behaviour to cell number, providing a more accurate picture of, for example, anabolic -activity. There are wide arrays of cell viability methods which range from the most routine trypan blue dye exclusion assay to highly complex analysis of individual cells, such as using RAMAN microscopy. The cost, speed, and complexity of equipment required will all play a role in determining the assay used. This chapter aims to provide an overview of many of the assays available today.

  11. Cell Factory Engineering.

    PubMed

    Davy, Anne Mathilde; Kildegaard, Helene Faustrup; Andersen, Mikael Rørdam

    2017-03-22

    Rational approaches to modifying cells to make molecules of interest are of substantial economic and scientific interest. Most of these efforts aim at the production of native metabolites, expression of heterologous biosynthetic pathways, or protein expression. Reviews of these topics have largely focused on individual strategies or cell types, but collectively they fall under the broad umbrella of a growing field known as cell factory engineering. Here we condense >130 reviews and key studies in the art into a meta-review of cell factory engineering. We identified 33 generic strategies in the field, all applicable to multiple types of cells and products, and proven successful in multiple major cell types. These apply to three major categories: production of native metabolites and/or bioactives, heterologous expression of biosynthetic pathways, and protein expression. This meta-review provides general strategy guides for the broad range of applications of rational engineering of cell factories. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Natural killer cell deficiency.

    PubMed

    Orange, Jordan S

    2013-09-01

    Natural killer (NK) cells are part of the innate immune defense against infection and cancer and are especially useful in combating certain viral pathogens. The utility of NK cells in human health has been underscored by a growing number of persons who are deficient in NK cells and/or their functions. This can be in the context of a broader genetically defined congenital immunodeficiency, of which there are more than 40 presently known to impair NK cells. However, the abnormality of NK cells in certain cases represents the majority immunologic defect. In aggregate, these conditions are termed NK cell deficiency. Recent advances have added clarity to this diagnosis and identified defects in 3 genes that can cause NK cell deficiency, as well as some of the underlying biology. Appropriate consideration of these diagnoses and patients raises the potential for rational therapeutic options and further innovation.

  13. Human regulatory B cells control the TFH cell response.

    PubMed

    Achour, Achouak; Simon, Quentin; Mohr, Audrey; Séité, Jean-François; Youinou, Pierre; Bendaoud, Boutahar; Ghedira, Ibtissem; Pers, Jacques-Olivier; Jamin, Christophe

    2017-07-01

    Follicular helper T (TFH) cells support terminal B-cell differentiation. Human regulatory B (Breg) cells modulate cellular responses, but their control of TFH cell-dependent humoral immune responses is unknown. We sought to assess the role of Breg cells on TFH cell development and function. Human T cells were polyclonally stimulated in the presence of IL-12 and IL-21 to generate TFH cells. They were cocultured with B cells to induce their terminal differentiation. Breg cells were included in these cultures, and their effects were evaluated by using flow cytometry and ELISA. B-cell lymphoma 6, IL-21, inducible costimulator, CXCR5, and programmed cell death protein 1 (PD-1) expressions increased on stimulated human T cells, characterizing TFH cell maturation. In cocultures they differentiated B cells into CD138(+) plasma and IgD(-)CD27(+) memory cells and triggered immunoglobulin secretions. Breg cells obtained by Toll-like receptor 9 and CD40 activation of B cells prevented TFH cell development. Added to TFH cell and B-cell cocultures, they inhibited B-cell differentiation, impeded immunoglobulin secretions, and expanded Foxp3(+)CXCR5(+)PD-1(+) follicular regulatory T cells. Breg cells modulated IL-21 receptor expressions on TFH cells and B cells, and their suppressive activities involved CD40, CD80, CD86, and intercellular adhesion molecule interactions and required production of IL-10 and TGF-β. Human Breg cells control TFH cell maturation, expand follicular regulatory T cells, and inhibit the TFH cell-mediated antibody secretion. These novel observations demonstrate a role for the Breg cell in germinal center reactions and suggest that deficient activities might impair the TFH cell-dependent control of humoral immunity and might lead to the development of aberrant autoimmune responses. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  14. Erratum: Consumption of whole grains and cereal fiber and total and cause-specific mortality: prospective analysis of 367,442 individuals.

    PubMed

    Huang, Tao; Xu, Min; Lee, Albert; Cho, Susan; Qi, Lu

    2015-04-16

    This is an Erratum to BMC Medicine 2015, 13:59, highlighting previously undeclared competing interests and including more information in the acknowledgements section.Please see related article: http://www.biomedcentral.com/1741-7015/13/59. The statement in the competing interests should read as follows: This study is funded by unrestricted research fund from NutraSource. Susan Cho is founder and owner of NutraSource and Albert Lee is an employee of NutraSource. The other authors declare that they have no competing interests. The following information should be included in the acknowledgements section: The authors also thank Dr. Yi K Park at National Cancer Institute for her guidance in the study design.

  15. Nevoid basal cell carcinoma syndrome

    MedlinePlus

    NBCC syndrome; Gorlin-Goltz syndrome; Basal cell nevus syndrome; BCNS; Basal cell cancer - nevoid basal cell carcinoma syndrome ... Nevoid basal cell carcinoma nevus syndrome is a rare genetic condition. The gene linked to the syndrome is known as PTCH (" ...

  16. Sickle Cell Crisis (For Teens)

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Sickle Cell Crisis (Pain Crisis) KidsHealth > For Teens > Sickle Cell ... drepanocíticas (Crisis de dolor) What Is a Sickle Cell Crisis? Sickle cell disease changes the shape of ...

  17. High Red Blood Cell Count

    MedlinePlus

    Symptoms High red blood cell count By Mayo Clinic Staff A high red blood cell count is an increase in oxygen-carrying cells in your bloodstream. Red blood cells transport oxygen from your lungs to tissues throughout ...

  18. Membrane Cells for Brine Electrolysis.

    ERIC Educational Resources Information Center

    Tingle, M.

    1982-01-01

    Membrane cells were developed as alternatives to mercury and diaphragm cells for the electrolysis of brine. Compares the three types of cells, focusing on the advantages and disadvantages of membrane cells. (JN)

  19. Cutaneous hamartoma with pagetoid cells.

    PubMed

    Piérard-Franchimont, C; Dosal, F L; Estrada, J A; Piérard, G E

    1991-04-01

    We report an unusual cutaneous hamartoma with pagetoid cells characterized by the presence of intraepidermal cells resembling Toker's cells of the nipple. These cells were EMA positive and could be related to the histogenesis of some Paget's disease.

  20. Membrane Cells for Brine Electrolysis.

    ERIC Educational Resources Information Center

    Tingle, M.

    1982-01-01

    Membrane cells were developed as alternatives to mercury and diaphragm cells for the electrolysis of brine. Compares the three types of cells, focusing on the advantages and disadvantages of membrane cells. (JN)

  1. Cell-to-cell binding induced by different lectins.

    PubMed

    Rutishauser, U; Sachs, L

    1975-05-01

    The cell-to-cell binding induced by concanavalin A (Con A) and the lectins from wheatgerm, soybean, and waxbean has been analyzed by measuring the ability of single cells to bind to lectin-coated cells immobilized on nylon fibers. The cells used were lymphoma, myeloid leukemia, and normal fibroblast cells. With all lectins, cell-to-cell binding was inhibited if both cells were prefixed with glutaraldehyde. However, in most cases cell-to-cell binding was enhanced when only the lectin-coated cell was prefixed. With normal fibroblasts, treatment of either one or both cells with trypsin enhanced the cell-to-cell binding induced by Con A and the wheatgerm lectin. Neuraminidase, which increases the number of receptors for soybean agglutinin, increased cell-to-cell binding only if both cells were treated. Although cell-to-cell binding induced by the lectins from soybean and wheatgerm could be partially reversed by the appropriate competitive saccharide inhibitor, binding induced by Con A could not be reversed. The experiments indicate that cell-to-cell binding induced by a lectin can be prevented by an insufficient density of receptors for the lectin, insufficient receptor mobility, or induced clustering of receptors. These effects can explain the differences in cell-to-cell binding and agglutination observed with different cell types and lectins. They also suggest that cell-to-cell binding induced by different lectins with a variety of cell types is initiated by a mechanism involving the alignment of complementary receptors on the colliding cells for the formation of multiple cell-to-lectin-to-cell bridges.

  2. Nestin(+) cells direct inflammatory cell migration in atherosclerosis.

    PubMed

    Del Toro, Raquel; Chèvre, Raphael; Rodríguez, Cristina; Ordóñez, Antonio; Martínez-González, José; Andrés, Vicente; Méndez-Ferrer, Simón

    2016-09-02

    Atherosclerosis is a leading death cause. Endothelial and smooth muscle cells participate in atherogenesis, but it is unclear whether other mesenchymal cells contribute to this process. Bone marrow (BM) nestin(+) cells cooperate with endothelial cells in directing monocyte egress to bloodstream in response to infections. However, it remains unknown whether nestin(+) cells regulate inflammatory cells in chronic inflammatory diseases, such as atherosclerosis. Here, we show that nestin(+) cells direct inflammatory cell migration during chronic inflammation. In Apolipoprotein E (ApoE) knockout mice fed with high-fat diet, BM nestin(+) cells regulate the egress of inflammatory monocytes and neutrophils. In the aorta, nestin(+) stromal cells increase ∼30 times and contribute to the atheroma plaque. Mcp1 deletion in nestin(+) cells-but not in endothelial cells only- increases circulating inflammatory cells, but decreases their aortic infiltration, delaying atheroma plaque formation and aortic valve calcification. Therefore, nestin expression marks cells that regulate inflammatory cell migration during atherosclerosis.

  3. Mechanics and regulation of cell shape during the cell cycle.

    PubMed

    Clark, Andrew G; Paluch, Ewa

    2011-01-01

    Many cell types undergo dramatic changes in shape throughout the cell cycle. For individual cells, a tight control of cell shape is crucial during cell division, but also in interphase, for example during cell migration. Moreover, cell cycle-related cell shape changes have been shown to be important for tissue morphogenesis in a number of developmental contexts. Cell shape is the physical result of cellular mechanical properties and of the forces exerted on the cell. An understanding of the causes and repercussions of cell shape changes thus requires knowledge of both the molecular regulation of cellular mechanics and how specific changes in cell mechanics in turn effect global shape changes. In this chapter, we provide an overview of the current knowledge on the control of cell morphology, both in terms of general cell mechanics and specifically during the cell cycle.

  4. Cell-to-cell transmission can overcome multiple donor and target cell barriers imposed on cell-free HIV.

    PubMed

    Zhong, Peng; Agosto, Luis M; Ilinskaya, Anna; Dorjbal, Batsukh; Truong, Rosaline; Derse, David; Uchil, Pradeep D; Heidecker, Gisela; Mothes, Walther

    2013-01-01

    Virus transmission can occur either by a cell-free mode through the extracellular space or by cell-to-cell transmission involving direct cell-to-cell contact. The factors that determine whether a virus spreads by either pathway are poorly understood. Here, we assessed the relative contribution of cell-free and cell-to-cell transmission to the spreading of the human immunodeficiency virus (HIV). We demonstrate that HIV can spread by a cell-free pathway if all the steps of the viral replication cycle are efficiently supported in highly permissive cells. However, when the cell-free path was systematically hindered at various steps, HIV transmission became contact-dependent. Cell-to-cell transmission overcame barriers introduced in the donor cell at the level of gene expression and surface retention by the restriction factor tetherin. Moreover, neutralizing antibodies that efficiently inhibit cell-free HIV were less effective against cell-to-cell transmitted virus. HIV cell-to-cell transmission also efficiently infected target T cells that were relatively poorly susceptible to cell-free HIV. Importantly, we demonstrate that the donor and target cell types influence critically the extent by which cell-to-cell transmission can overcome each barrier. Mechanistically, cell-to-cell transmission promoted HIV spread to more cells and infected target cells with a higher proviral content than observed for cell-free virus. Our data demonstrate that the frequently observed contact-dependent spread of HIV is the result of specific features in donor and target cell types, thus offering an explanation for conflicting reports on the extent of cell-to-cell transmission of HIV.

  5. NKT cells in leishmaniasis.

    PubMed

    Zamora-Chimal, Jaime; Hernández-Ruiz, Joselín; Becker, Ingeborg

    2017-04-01

    The role of NKT cells in the resistance or susceptibility towards Leishmania infections remains to be defined, since controversial data persist. The response of these cells seems to depend on many variables such as the infection site, the number of infecting parasites, the virulence of the strain and the Leishmania species. We here revise the activation pathways leading to NKT cell activation. NKT cells can be activated by the direct pathway, in which Leishmania glycolipids are presented by CD1d molecules on antigen presenting cells, such as dendritic cells (DC), leading to the secretion of diverse cytokines by NKT. NKT cells can also be activated by the indirect pathway, in which Leishmania glycolipids, such as LPG, stimulate TLR2 in DC, inducing their IL-12 production, which in turn activates NKT cells. The review further analyzes the role of NKT cells in disease development, both in humans as in mouse models. Finally we propose the activation of NKT cells for controlling Leishmania infections. Copyright © 2016 Elsevier GmbH. All rights reserved.

  6. Nanofluidic fuel cell

    NASA Astrophysics Data System (ADS)

    Lee, Jin Wook; Kjeang, Erik

    2013-11-01

    Fuel cells are gaining momentum as a critical component in the renewable energy mix for stationary, transportation, and portable power applications. State-of-the-art fuel cell technology benefits greatly from nanotechnology applied to nanostructured membranes, catalysts, and electrodes. However, the potential of utilizing nanofluidics for fuel cells has not yet been explored, despite the significant opportunity of harnessing rapid nanoscale reactant transport in close proximity to the reactive sites. In the present article, a nanofluidic fuel cell that utilizes fluid flow through nanoporous media is conceptualized and demonstrated for the first time. This transformative concept captures the advantages of recently developed membraneless and catalyst-free fuel cell architectures paired with the enhanced interfacial contact area enabled by nanofluidics. When compared to previously reported microfluidic fuel cells, the prototype nanofluidic fuel cell demonstrates increased surface area, reduced activation overpotential, superior kinetic characteristics, and moderately enhanced fuel cell performance in the high cell voltage regime with up to 14% higher power density. However, the expected mass transport benefits in the high current density regime were constrained by high ohmic cell resistance, which could likely be resolved through future optimization studies.

  7. Mast Cell Function

    PubMed Central

    da Silva, Elaine Zayas Marcelino; Jamur, Maria Célia

    2014-01-01

    Since first described by Paul Ehrlich in 1878, mast cells have been mostly viewed as effectors of allergy. It has been only in the past two decades that mast cells have gained recognition for their involvement in other physiological and pathological processes. Mast cells have a widespread distribution and are found predominantly at the interface between the host and the external environment. Mast cell maturation, phenotype and function are a direct consequence of the local microenvironment and have a marked influence on their ability to specifically recognize and respond to various stimuli through the release of an array of biologically active mediators. These features enable mast cells to act as both first responders in harmful situations as well as to respond to changes in their environment by communicating with a variety of other cells implicated in physiological and immunological responses. Therefore, the critical role of mast cells in both innate and adaptive immunity, including immune tolerance, has gained increased prominence. Conversely, mast cell dysfunction has pointed to these cells as the main offenders in several chronic allergic/inflammatory disorders, cancer and autoimmune diseases. This review summarizes the current knowledge of mast cell function in both normal and pathological conditions with regards to their regulation, phenotype and role. PMID:25062998

  8. CELL RESPIRATION STUDIES

    PubMed Central

    Daland, Geneva A.; Isaacs, Raphael

    1927-01-01

    1. The oxygen consumption of blood of normal individuals, when the hemoglobin is saturated with oxygen, is practically zero within the limits of experimental error of the microspirometer used. 2. The oxygen consumed in a microspirometer by the blood of patients with chronic myelogenous leucemia with a high white blood cell count, and of one with leucocytosis from sepsis, was proportional to the number of adult polymorphonuclear neutrophils in the blood. 3. No correlation could be made between the rate of oxygen absorption and the total number of white blood cells in the blood, or the total number of immature cells, or the number of red blood cells, or the amount of oxyhemoglobin. 4. The blood of patients with chronic myelogenous leucemia continued to use oxygen in the microspirometer longer than that of normal individuals, and the hemoglobin, in the leucemic bloods, became desaturated even though exposed to air. 5. In blood in which the bulk. of the cells were immature and the mature cells few, the oxygen consumption was lower than in blood in which the mature cells predominated. The rate of oxygen consumption of the immature cells was relatively low as compared to the mature. 6. The slower rate of oxygen absorption by the immature leucocytes in chronic myelogenous leucemia as compared to the mature cells, places them, in accord with Warburg's reports, in the class of the malignant tissues in this respect rather than in the group of young or embryonic cells. PMID:19869329

  9. Reflections on cell competition.

    PubMed

    Baillon, Ludovic; Basler, Konrad

    2014-08-01

    Cell competition is a process by which otherwise viable cells are actively eliminated due to the presence of more competitive cells. It is a conserved phenomenon and occurs in various developmental and experimental contexts. Competitive elimination represents a safeguard mechanism that potentiates animal development. However, the process can also be hijacked, for example, by cancer cells to promote and sustain malignancy. One of the challenges facing the field is that the term "cell competition" is used to describe a variety of phenomena whose relatedness is under debate. The goals of this review are to provide an overview of the literature on cell competition-like phenomena, highlight where there are discrepancies, and, when possible, provide alternative interpretations to reconcile the dissonance. Central to this is a comparison of the various models of cell competition. With our critical examination we seek to draw attention to future prospects in the field of cell competition. We believe that the elucidation of the interplay between loser and winner cells in the process of cell competition will provide new targets for the development of cancer therapeutics. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Single cell wound repair

    PubMed Central

    Abreu-Blanco, Maria Teresa; Verboon, Jeffrey M

    2011-01-01

    Cell wounding is a common event in the life of many cell types, and the capacity of the cell to repair day-to-day wear-and-tear injuries, as well as traumatic ones, is fundamental for maintaining tissue integrity. Cell wounding is most frequent in tissues exposed to high levels of stress. Survival of such plasma membrane disruptions requires rapid resealing to prevent the loss of cytosolic components, to block Ca2+ influx and to avoid cell death. In addition to patching the torn membrane, plasma membrane and cortical cytoskeleton remodeling are required to restore cell function. Although a general understanding of the cell wound repair process is in place, the underlying mechanisms of each step of this response are not yet known. We have developed a model to study single cell wound repair using the early Drosophila embryo. Our system combines genetics and live imaging tools, allowing us to dissect in vivo the dynamics of the single cell wound response. We have shown that cell wound repair in Drosophila requires the coordinated activities of plasma membrane and cytoskeleton components. Furthermore, we identified an unexpected role for E-cadherin as a link between the contractile actomyosin ring and the newly formed plasma membrane plug. PMID:21922041

  11. T Cells in Fish

    PubMed Central

    Nakanishi, Teruyuki; Shibasaki, Yasuhiro; Matsuura, Yuta

    2015-01-01

    Cartilaginous and bony fish are the most primitive vertebrates with a thymus, and possess T cells equivalent to those in mammals. There are a number of studies in fish demonstrating that the thymus is the essential organ for development of T lymphocytes from early thymocyte progenitors to functionally competent T cells. A high number of T cells in the intestine and gills has been reported in several fish species. Involvement of CD4+ and CD8α+ T cells in allograft rejection and graft-versus-host reaction (GVHR) has been demonstrated using monoclonal antibodies. Conservation of CD4+ helper T cell functions among teleost fishes has been suggested in a number studies employing mixed leukocyte culture (MLC) and hapten/carrier effect. Alloantigen- and virus-specific cytotoxicity has also been demonstrated in ginbuna and rainbow trout. Furthermore, the important role of cell-mediated immunity rather than humoral immunity has been reported in the protection against intracellular bacterial infection. Recently, the direct antibacterial activity of CD8α+, CD4+ T-cells and sIgM+ cells in fish has been reported. In this review, we summarize the recent progress in T cell research focusing on the tissue distribution and function of fish T cells. PMID:26426066

  12. Simple Cell Balance Circuit

    NASA Technical Reports Server (NTRS)

    Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

    2012-01-01

    A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

  13. The Chlamydomonas cell cycle.

    PubMed

    Cross, Frederick R; Umen, James G

    2015-05-01

    The position of Chlamydomonas within the eukaryotic phylogeny makes it a unique model in at least two important ways: as a representative of the critically important, early-diverging lineage leading to plants; and as a microbe retaining important features of the last eukaryotic common ancestor (LECA) that has been lost in the highly studied yeast lineages. Its cell biology has been studied for many decades and it has well-developed experimental genetic tools, both classical (Mendelian) and molecular. Unlike land plants, it is a haploid with very few gene duplicates, making it ideal for loss-of-function genetic studies. The Chlamydomonas cell cycle has a striking temporal and functional separation between cell growth and rapid cell division, probably connected to the interplay between diurnal cycles that drive photosynthetic cell growth and the cell division cycle; it also exhibits a highly choreographed interaction between the cell cycle and its centriole-basal body-flagellar cycle. Here, we review the current status of studies of the Chlamydomonas cell cycle. We begin with an overview of cell-cycle control in the well-studied yeast and animal systems, which has yielded a canonical, well-supported model. We discuss briefly what is known about similarities and differences in plant cell-cycle control, compared with this model. We next review the cytology and cell biology of the multiple-fission cell cycle of Chlamydomonas. Lastly, we review recent genetic approaches and insights into Chlamydomonas cell-cycle regulation that have been enabled by a new generation of genomics-based tools. © 2015 The Authors The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.

  14. Biology of Schwann cells.

    PubMed

    Kidd, Grahame J; Ohno, Nobuhiko; Trapp, Bruce D

    2013-01-01

    The fundamental roles of Schwann cells during peripheral nerve formation and regeneration have been recognized for more than 100 years, but the cellular and molecular mechanisms that integrate Schwann cell and axonal functions continue to be elucidated. Derived from the embryonic neural crest, Schwann cells differentiate into myelinating cells or bundle multiple unmyelinated axons into Remak fibers. Axons dictate which differentiation path Schwann cells follow, and recent studies have established that axonal neuregulin1 signaling via ErbB2/B3 receptors on Schwann cells is essential for Schwann cell myelination. Extracellular matrix production and interactions mediated by specific integrin and dystroglycan complexes are also critical requisites for Schwann cell-axon interactions. Myelination entails expansion and specialization of the Schwann cell plasma membrane over millimeter distances. Many of the myelin-specific proteins have been identified, and transgenic manipulation of myelin genes have provided novel insights into myelin protein function, including maintenance of axonal integrity and survival. Cellular events that facilitate myelination, including microtubule-based protein and mRNA targeting, and actin based locomotion, have also begun to be understood. Arguably, the most remarkable facet of Schwann cell biology, however, is their vigorous response to axonal damage. Degradation of myelin, dedifferentiation, division, production of axonotrophic factors, and remyelination all underpin the substantial regenerative capacity of the Schwann cells and peripheral nerves. Many of these properties are not shared by CNS fibers, which are myelinated by oligodendrocytes. Dissecting the molecular mechanisms responsible for the complex biology of Schwann cells continues to have practical benefits in identifying novel therapeutic targets not only for Schwann cell-specific diseases but other disorders in which axons degenerate.

  15. Successful differentiation to T cells, but unsuccessful B-cell generation, from B-cell-derived induced pluripotent stem cells.

    PubMed

    Wada, Haruka; Kojo, Satoshi; Kusama, Chie; Okamoto, Naoki; Sato, Yorino; Ishizuka, Bunpei; Seino, Ken-ichiro

    2011-01-01

    Forced expression of certain transcription factors in somatic cells results in generation of induced pluripotent stem (iPS) cells, which differentiate into various cell types. We investigated T-cell and B-cell lineage differentiation from iPS cells in vitro. To evaluate the impact of iPS cell source, murine splenic B-cell-derived iPS (B-iPS) cells were generated after retroviral transduction of four transcription factors (Oct4, Sox2, Klf4 and c-Myc). B-iPS cells were identical to embryonic stem (ES) cells and mouse embryonic fibroblast (MEF)-derived iPS cells in morphology, ES cell marker expression as well as teratoma and chimera mouse formation. Both B-iPS and MEF-derived iPS cells differentiated into lymphocytes in OP9 co-culture systems. Both efficiently differentiated into T-cell lineage that produced IFN-γ on T-cell receptor stimulation. However, iPS cells including B-iPS cells were relatively resistant to B-cell lineage differentiation. One of the reasons of the failure of B-cell lineage differentiation seemed due to a defect of Pax5 expression in the differentiated cells. Therefore, current in vitro differentiation systems using iPS cells are sufficient for inducing T-cell but not B-cell lineage.

  16. Cell Research and Technology Workshop

    NASA Technical Reports Server (NTRS)

    Hutchby, J.

    1985-01-01

    Four major areas in solar cell research and technology were considered. The areas were: (1) the silicon cell; (2) the GaAs cell; (3) the multibandgap cell; and (4) novel ideas. In each area material research issues, cell research issues, and the cell technology that needs development are considered.

  17. Cell-Substrate Adhesion by Amoeboid Cells

    NASA Astrophysics Data System (ADS)

    Flanders, Bret; Panta, Krishna

    Amoeboid migration is a rapid (10 μm min-1) mode of migration that some tumor cells exhibit. To permit such rapid movement, the adhesive contacts between the cell and the substrate must be relatively short-lived and weak. In this study, we investigate the basic adhesive character of amoeboid cells (D. discoideum) in contact with silanized glass substrates. We observe the initiation and spreading of the adhesive contacts that these cells establish as they settle under gravity onto the substrate and relax towards mechanical equilibrium. The use of interference reflection microscopy and cellular tethering measurements have allowed us to determine the basic adhesive properties of the cell: the membrane-medium interfacial energy; the bending modulus; the equilibrium contact angle; and the work of adhesion. We find the time scale on which settling occurs to be longer than expected. Implications of these results on adhesion and migration will be discussed. The authors are grateful for support from NSF (CBET-1451903) and NIH (1R21EY026392).

  18. New Cell Sources for T Cell Engineering and Adoptive Immunotherapy

    PubMed Central

    Themeli, Maria; Rivière, Isabelle; Sadelain, Michel

    2017-01-01

    The promising clinical results obtained with engineered T cells, including chimeric antigen receptor (CAR) therapy, call for further advancements to facilitate and broaden their applicability. One potentially beneficial innovation is to exploit new T cell sources that reduce the need for autologous cell manufacturing and enable cell transfer across histocompatibility barriers. Here we review emerging T cell engineering approaches that utilize alternative T cell sources, which include virus-specific or T cell receptor-less allogeneic T cells, expanded lymphoid progenitors, and induced pluripotent stem cell (iPSC)-derived T lymphocytes. The latter offer the prospect for true off-the-shelf, genetically enhanced, histocompatible cell therapy products. PMID:25842976

  19. Isolation of rare cancer cells from blood cells using dielectrophoresis.

    PubMed

    Salmanzadeh, Alireza; Sano, Michael B; Shafiee, Hadi; Stremler, Mark A; Davalos, Rafael V

    2012-01-01

    In this study, we investigate the application of contactless dielectrophoresis (cDEP) for isolating cancer cells from blood cells. Devices with throughput of 0.2 mL/hr (equivalent to sorting 3×10(6) cells per minute) were used to trap breast cancer cells while allowing blood cells through. We have shown that this technique is able to isolate cancer cells in concentration as low as 1 cancer cell per 10(6) hematologic cells (equivalent to 1000 cancer cells in 1 mL of blood). We achieved 96% trapping of the cancer cells at 600 kHz and 300 V(RMS).

  20. Embryonic stem cell-somatic cell fusion and postfusion enucleation.

    PubMed

    Sumer, Huseyin; Verma, Paul J

    2015-01-01

    Embryonic stem (ES) cells are able to reprogram somatic cells following cell fusion. The resulting cell hybrids have been shown to have similar properties to pluripotent cells. It has also been shown that transcriptional changes can occur in a heterokaryon, without nuclear hybridization. However it is unclear whether these changes can be sustained following removal of the dominant ES nucleus. In this chapter, methods are described for the cell fusion of mouse tetraploid ES cells with somatic cells and enrichment of the resulting heterokaryons. We next describe the conditions for the differential removal of the ES cell nucleus, allowing for the recovery of somatic cells.

  1. Solar cell shingle

    NASA Technical Reports Server (NTRS)

    Forestieri, A. F.; Ratajczak, A. F.; Sidorak, L. G. (Inventor)

    1977-01-01

    A solar cell shingle was made of an array of solar cells on a lower portion of a substantially rectangular shingle substrate made of fiberglass cloth or the like. The solar cells may be encapsulated in flourinated ethylene propylene or some other weatherproof translucent or transparent encapsulant to form a combined electrical module and a roof shingle. The interconnected solar cells were connected to connectors at the edge of the substrate through a connection to a common electrical bus or busses. An overlap area was arranged to receive the overlap of a cooperating similar shingle so that the cell portion of the cooperating shingle may overlie the overlap area of the roof shingle. Accordingly, the same shingle serves the double function of an ordinary roof shingle which may be applied in the usual way and an array of cooperating solar cells from which electrical energy may be collected.

  2. Stochasticity and Cell Fate

    PubMed Central

    Losick, Richard; Desplan, Claude

    2008-01-01

    Summary Fundamental to living cells is the capacity to differentiate into subtypes with specialized attributes. Understanding the way cells acquire their fates is a major challenge in developmental biology. How cells adopt a particular fate is usually thought of as being deterministic, and in the large majority of cases it is. That is, cells acquire their fate by virtue of their lineage or their proximity to an inductive signal from another cell. In some cases, however, and in organisms ranging from bacteria to humans, cells choose one or another pathway of differentiation stochastically without apparent regard to environment or history. Stochasticity has important mechanistic requirements as we discuss. We will also speculate on why stochasticity is advantageous, and even critical in some circumstances, to the individual, the colony, or the species. PMID:18388284

  3. Amorphous silicon solar cells

    NASA Astrophysics Data System (ADS)

    Takahashi, K.; Konagai, M.

    The fabrication, performance, and applications of a-Si solar cells are discussed, summarizing the results of recent experimental investigations and trial installations. Topics examined include the fundamental principles and design strategies of solar power installations; the characteristics of monocrystalline-Si solar cells; techniques for reducing the cost of solar cells; independent, linked, and hybrid solar power systems; proposed satellite solar power systems; and the use of solar cells in consumer appliances. Consideration is given to the history of a-Si, a-Si fabrication techniques, quality criteria for a-Si films, solar cells based on a-Si, and techniques for increasing the efficiency and lowering the cost of a-Si solar cells. Graphs, diagrams, drawings, and black-and-white and color photographs are provided.

  4. Dot junction solar cells

    NASA Technical Reports Server (NTRS)

    Daud, T.; Crotty, G. T.

    1986-01-01

    A design of solar cells with reduced junction area on the cell surface is investigated for reduction of saturation current and increase in open-circuit voltage. Equidiameter dot junctions distributed across the surface of the cell offer an efficient alternative, with variations in dot diameter and in the spacing between dots giving the required variations in the ratio of junction area to total surface area. A simplified analysis for short-circuit current and other cell parameters, which enables cell design optimization, is presented. Experimental solar-cell performance results, as functions of different area ratios, are presented and compared with the model. It is shown that saturation current reduction is possible for achieving efficiencies as high as 18 percent in flat-plate terrestrial applications.

  5. Melanoma stem cells.

    PubMed

    Roesch, Alexander

    2015-02-01

    The cancer stem cell concept significantly broadens our understanding of melanoma biology. However, this concept should be regarded as an integral part of a holistic cancer model that also includes the genetic evolution of tumor cells and the variability of cell phenotypes within a dynamic tumor microenvironment. The biologic complexity and methodological difficulties in identifying cancer stem cells and their biomarkers are currently impeding the direct translation of experimental findings into clinical practice. Nevertheless, it is these methodological shortcomings that provide a new perspective on the phenotypic heterogeneity and plasticity of melanoma with important consequences for future therapies. The development of new combination treatment strategies, particularly with regard to overcoming treatment resistance, could significantly benefit from targeted elimination of cell subpopulations with cancer stem cell properties. © 2015 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  6. Cell Therapy in Dermatology

    PubMed Central

    Petrof, Gabriela; Abdul-Wahab, Alya; McGrath, John A.

    2014-01-01

    Harnessing the regenerative capacity of keratinocytes and fibroblasts from human skin has created new opportunities to develop cell-based therapies for patients. Cultured cells and bioengineered skin products are being used to treat patients with inherited and acquired skin disorders associated with defective skin, and further clinical trials of new products are in progress. The capacity of extracutaneous sources of cells such as bone marrow is also being investigated for its plasticity in regenerating skin, and new strategies, such as the derivation of inducible pluripotent stem cells, also hold great promise for future cell therapies in dermatology. This article reviews some of the preclinical and clinical studies and future directions relating to cell therapy in dermatology, particularly for inherited skin diseases associated with fragile skin and poor wound healing. PMID:24890834

  7. Memory B cells.

    PubMed

    Kurosaki, Tomohiro; Kometani, Kohei; Ise, Wataru

    2015-03-01

    The immune system can remember a previously experienced pathogen and can evoke an enhanced response to reinfection that depends on memory lymphocyte populations. Recent advances in tracking antigen-experienced memory B cells have revealed the existence of distinct classes of cells that have considerable functional differences. Some of these differences seem to be determined by the stimulation history during memory cell formation. To induce rapid recall antibody responses, the contributions of other types of cells, such as memory T follicular helper cells, have also now begun to be appreciated. In this Review, we discuss these and other recent advances in our understanding of memory B cells, focusing on the underlying mechanisms that are required for rapid and effective recall antibody responses.

  8. STUDIES OF CELL DEFORMABILITY

    PubMed Central

    Weiss, Leonard

    1967-01-01

    Cells grown in suspension culture were incubated with EDTA-disodium salt and shown to have more easily deformable surfaces and raised electrophoretic mobility than controls, following this treatment. The reversibility of these observations by the addition of calcium ions, and other parallel experiments, support the conclusion that, in these cells, calcium is bound to anionic sites at the cell periphery, some of which are located at the cellular electrokinetic surface. These cells should, therefore, exhibit demonstrable calcium-sensitive aggregation, if current theories on the role of calcium in the physiological situation are correct. The fact that no calcium-sensitive aggregation was observed suggests that calcium does not form "bridges" between the adjacent anionic sites on different cells, and does not act directly by its effects on the diffuse electrical double-layer in this situation. An alternative hypothesis is advanced for the role played by calcium in cell adhesion and separation processes. PMID:4964313

  9. Mechanical plasticity of cells

    NASA Astrophysics Data System (ADS)

    Bonakdar, Navid; Gerum, Richard; Kuhn, Michael; Spörrer, Marina; Lippert, Anna; Schneider, Werner; Aifantis, Katerina E.; Fabry, Ben

    2016-10-01

    Under mechanical loading, most living cells show a viscoelastic deformation that follows a power law in time. After removal of the mechanical load, the cell shape recovers only incompletely to its original undeformed configuration. Here, we show that incomplete shape recovery is due to an additive plastic deformation that displays the same power-law dynamics as the fully reversible viscoelastic deformation response. Moreover, the plastic deformation is a constant fraction of the total cell deformation and originates from bond ruptures within the cytoskeleton. A simple extension of the prevailing viscoelastic power-law response theory with a plastic element correctly predicts the cell behaviour under cyclic loading. Our findings show that plastic energy dissipation during cell deformation is tightly linked to elastic cytoskeletal stresses, which suggests the existence of an adaptive mechanism that protects the cell against mechanical damage.

  10. [Regulatory T cells].

    PubMed

    Marinić, Igor; Gagro, Alenka; Rabatić, Sabina

    2006-12-01

    Regulatory T-cells are a subset of T cells that have beene extensively studied in modern immunology. They are important for the maintenance of peripheral tolerance, and have an important role in various clinical conditions such as allergy, autoimmune disorders, tumors, infections, and in transplant medicine. Basically, this population has a suppressive effect on the neighboring immune cells, thus contributing to the local modulation and control of immune response. There are two main populations of regulatory T cells - natural regulatory T cells, which form a distinct cellular lineage, develop in thymus and perform their modulatory action through direct intercellular contact, along with the secreted cytokines; and inducible regulatory T cells, which develop in the periphery after contact with the antigen that is presented on the antigen presenting cell, and their primary mode of action is through the interleukin 10 (IL-10) and transforming growth factor beta (TGF-alpha) cytokines. Natural regulatory T cells are activated through T cell receptor after contact with specific antigen and inhibit proliferation of other T cells in an antigen independent manner. One of the major difficulties in the research of regulatory T cells is the lack of specific molecular markers that would identify these cells. Natural regulatory T cells constitutively express surface molecule CD25, but many other surface and intracellular molecules (HLA-DR, CD122, CD45RO, CD62, CTLA-4, GITR, PD-1, Notch, FOXP3, etc.) are being investigated for further phenotypic characterization of these cells. Because regulatory T cells have an important role in establishing peripheral tolerance, their importance is manifested in a number of clinical conditions. In the IPEX syndrome (immunodysregulation, polyendocrinopathy and enteropathy, X-linked), which is caused by mutation in Foxp3 gene that influences the development and function of regulatory T cells, patients develop severe autoimmune reactions that

  11. The CLL cell microenvironment.

    PubMed

    Burger, Jan A

    2013-01-01

    Cross talk between CLL cells and accessory stromal cells in specialized tissue microenvironments, such as the secondary lymphoid organs, favors CLL progression by promoting malignant B cell growth and drug resistance. Disrupting the cross talk between CLL cells and their milieu is an attractive, novel strategy for treating CLL patients. This chapter summarizes current knowledge about cellular and molecular interactions between CLL cells and their supportive tissue microenvironment and the therapeutic targets that are emerging, focusing on the CXCR4-CXCL12 axis and small molecule inhibitors that are targeting the B cell receptor-associated kinases SYK, BTK, and PI3Kδ. Clinically relevant aspects of these new therapeutics will be discussed, along with an outlook into future biologically oriented therapeutic strategies. The rapid progress in dissecting the CLL microenvironment and the promising early results of these new targeted treatments in CLL indicate that CLL has become a role model for microenvironment-dependent cancers.

  12. Regulatory T cell memory

    PubMed Central

    Rosenblum, Michael D.; Way, Sing Sing; Abbas, Abul K.

    2016-01-01

    Memory for antigen is a defining feature of adaptive immunity. Antigen-specific lymphocyte populations show an increase in number and function after antigen encounter and more rapidly re-expand upon subsequent antigen exposure. Studies of immune memory have primarily focused on effector B cells and T cells with microbial specificity, using prime challenge models of infection. However, recent work has also identified persistently expanded populations of antigen-specific regulatory T cells that protect against aberrant immune responses. In this Review, we consider the parallels between memory effector T cells and memory regulatory T cells, along with the functional implications of regulatory memory in autoimmunity, antimicrobial host defence and maternal fetal tolerance. In addition, we discuss emerging evidence for regulatory T cell memory in humans and key unanswered questions in this rapidly evolving field. PMID:26688349

  13. Oral Rigosertib for Squamous Cell Carcinoma

    ClinicalTrials.gov

    2016-05-18

    Head and Neck Squamous Cell Carcinoma; Anal Squamous Cell Carcinoma; Lung Squamous Cell Carcinoma; Cervical Squamous Cell Carcinoma; Esophageal Squamous Cell Carcinoma; Skin Squamous Cell Carcinoma; Penile Squamous Cell Carcinoma

  14. Traction in smooth muscle cells varies with cell spreading

    NASA Technical Reports Server (NTRS)

    Tolic-Norrelykke, Iva Marija; Wang, Ning

    2005-01-01

    Changes in cell shape regulate cell growth, differentiation, and apoptosis. It has been suggested that the regulation of cell function by the cell shape is a result of the tension in the cytoskeleton and the distortion of the cell. Here we explore the association between cell-generated mechanical forces and the cell morphology. We hypothesized that the cell contractile force is associated with the degree of cell spreading, in particular with the cell length. We measured traction fields of single human airway smooth muscle cells plated on a polyacrylamide gel, in which fluorescent microbeads were embedded to serve as markers of gel deformation. The traction exerted by the cells at the cell-substrate interface was determined from the measured deformation of the gel. The traction was measured before and after treatment with the contractile agonist histamine, or the relaxing agonist isoproterenol. The relative increase in traction induced by histamine was negatively correlated with the baseline traction. On the contrary, the relative decrease in traction due to isoproterenol was independent of the baseline traction, but it was associated with cell shape: traction decreased more in elongated than in round cells. Maximum cell width, mean cell width, and projected area of the cell were the parameters most tightly coupled to both baseline and histamine-induced traction in this study. Wide and well-spread cells exerted larger traction than slim cells. These results suggest that cell contractility is controlled by cell spreading.

  15. Quantitative methods for analyzing cell-cell adhesion in development.

    PubMed

    Kashef, Jubin; Franz, Clemens M

    2015-05-01

    During development cell-cell adhesion is not only crucial to maintain tissue morphogenesis and homeostasis, it also activates signalling pathways important for the regulation of different cellular processes including cell survival, gene expression, collective cell migration and differentiation. Importantly, gene mutations of adhesion receptors can cause developmental disorders and different diseases. Quantitative methods to measure cell adhesion are therefore necessary to understand how cells regulate cell-cell adhesion during development and how aberrations in cell-cell adhesion contribute to disease. Different in vitro adhesion assays have been developed in the past, but not all of them are suitable to study developmentally-related cell-cell adhesion processes, which usually requires working with low numbers of primary cells. In this review, we provide an overview of different in vitro techniques to study cell-cell adhesion during development, including a semi-quantitative cell flipping assay, and quantitative single-cell methods based on atomic force microscopy (AFM)-based single-cell force spectroscopy (SCFS) or dual micropipette aspiration (DPA). Furthermore, we review applications of Förster resonance energy transfer (FRET)-based molecular tension sensors to visualize intracellular mechanical forces acting on cell adhesion sites. Finally, we describe a recently introduced method to quantitate cell-generated forces directly in living tissues based on the deformation of oil microdroplets functionalized with adhesion receptor ligands. Together, these techniques provide a comprehensive toolbox to characterize different cell-cell adhesion phenomena during development. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Traction in smooth muscle cells varies with cell spreading

    NASA Technical Reports Server (NTRS)

    Tolic-Norrelykke, Iva Marija; Wang, Ning

    2005-01-01

    Changes in cell shape regulate cell growth, differentiation, and apoptosis. It has been suggested that the regulation of cell function by the cell shape is a result of the tension in the cytoskeleton and the distortion of the cell. Here we explore the association between cell-generated mechanical forces and the cell morphology. We hypothesized that the cell contractile force is associated with the degree of cell spreading, in particular with the cell length. We measured traction fields of single human airway smooth muscle cells plated on a polyacrylamide gel, in which fluorescent microbeads were embedded to serve as markers of gel deformation. The traction exerted by the cells at the cell-substrate interface was determined from the measured deformation of the gel. The traction was measured before and after treatment with the contractile agonist histamine, or the relaxing agonist isoproterenol. The relative increase in traction induced by histamine was negatively correlated with the baseline traction. On the contrary, the relative decrease in traction due to isoproterenol was independent of the baseline traction, but it was associated with cell shape: traction decreased more in elongated than in round cells. Maximum cell width, mean cell width, and projected area of the cell were the parameters most tightly coupled to both baseline and histamine-induced traction in this study. Wide and well-spread cells exerted larger traction than slim cells. These results suggest that cell contractility is controlled by cell spreading.

  17. Multijunction Cell Workshop

    NASA Technical Reports Server (NTRS)

    Kurtz, Sarah; Curtis, Henry

    1996-01-01

    Topics discussed include : (1) What needs to be done to fly GaInP/GaAs cells in the ENTECH linear concentrator for SCARLET 11; (2) wrap-through or wrap-around contacts - whether they available and useful, and the reasons why they are not used more; (3) directions to consider, including use of superlattices, 3 or 4 junctions, stacked cells, etc.; and (4) measurements - does every cell need to be tested under both red and blue illumination?

  18. Rechargeable Magnesium Power Cells

    NASA Technical Reports Server (NTRS)

    Koch, Victor R.; Nanjundiah, Chenniah; Orsini, Michael

    1995-01-01

    Rechargeable power cells based on magnesium anodes developed as safer alternatives to high-energy-density cells like those based on lithium and sodium anodes. At cost of some reduction in energy density, magnesium-based cells safer because less susceptible to catastrophic meltdown followed by flames and venting of toxic fumes. Other advantages include ease of handling, machining, and disposal, and relatively low cost.

  19. Immobilized Cell Research

    DTIC Science & Technology

    1990-10-31

    beads, the plasmid is twice as stable as in cells In a process where immobilized cells produce material grown in continuous culture over 200...carrageenan) or chemically cross-linked, or- Penicillium chrysogenum than in washed freely suspended ganic polymer (Ca-alginate, polyacrylamide, and mycelium ...these materials are formed into the freely suspended cells stopped after 6 days. If the beads of several millimeters in diameter by allowing the

  20. Direct hydrocarbon fuel cells

    DOEpatents

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  1. Granular cell ameloblastoma.

    PubMed

    Martin, Yakob; Sathyakumar, M; Premkumar, Jeyanthi; Magesh, K T

    2017-01-01

    A 42-year-female patient presented with a swelling on the left side of the face for the past 10 years. The radiograph shows multilocular radiolucency with evidence of root resorption. Histopathology reveals fibrous connective tissue exhibiting numerous odontogenic epithelial islands with peripheral tall columnar cells showing a reversal of polarity. The center of the island shows stellate reticulum like cells. The connective tissue also shows the presence of extensive coarse granular eosinophilic cells distributed throughout the section.

  2. Heterojunction solar cell

    SciTech Connect

    Olson, J.M.

    1994-08-30

    A high-efficiency single heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer. 1 fig.

  3. Heterojunction solar cell

    DOEpatents

    Olson, Jerry M.

    1994-01-01

    A high-efficiency single heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. The conversion effiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer.

  4. Heterojunction solar cell

    DOEpatents

    Olson, J.M.

    1994-08-30

    A high-efficiency single heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer. 1 fig.

  5. Systems cell biology

    PubMed Central

    Mast, Fred D.; Ratushny, Alexander V.

    2014-01-01

    Systems cell biology melds high-throughput experimentation with quantitative analysis and modeling to understand many critical processes that contribute to cellular organization and dynamics. Recently, there have been several advances in technology and in the application of modeling approaches that enable the exploration of the dynamic properties of cells. Merging technology and computation offers an opportunity to objectively address unsolved cellular mechanisms, and has revealed emergent properties and helped to gain a more comprehensive and fundamental understanding of cell biology. PMID:25225336

  6. Solar cell encapsulation

    NASA Technical Reports Server (NTRS)

    Gupta, Amitava (Inventor); Ingham, John D. (Inventor); Yavrouian, Andre H. (Inventor)

    1983-01-01

    A polymer syrup for encapsulating solar cell assemblies. The syrup includes uncrosslinked poly(n-butyl)acrylate dissolved in n-butyl acrylate monomer. Preparation of the poly(n-butyl)acrylate and preparation of the polymer syrup is disclosed. Methods for applying the polymer syrup to solar cell assemblies as an encapsulating pottant are described. Also included is a method for solar cell construction utilizing the polymer syrup as a dual purpose adhesive and encapsulating material.

  7. Cells as Drops and Drops as Cells

    NASA Astrophysics Data System (ADS)

    Dufresne, Eric R.

    2013-03-01

    How do the mechanical properties of tissues emerge from the interactions of individual cells? To shed some light on this fundamental biological question, we consider a model system of clusters of cohesive cells adherent to soft substrates. We quantify traction forces over a wide range of cluster sizes. The scaling of traction stresses with cluster size suggests the emergence of an apparent surface tension for large colonies. To explore the possible impact of cellular surface tension on physiology, we consider the behavior of liquid droplets on soft substrates. In this case, we find that the competition of surface tension and substrate elasticity can lead to rich phenomenology, mimicking certain aspects of the physiology of cells and tissues.

  8. The mast cell: a multifunctional effector cell.

    PubMed

    Crivellato, Enrico; Ribatti, Domenico; Mallardi, Franco; Beltrami, Carlo Alberto

    2003-01-01

    Mast cells (MC) are recognized key cells of type I hypersensitivity reactions. Several lines of evidence, however, indicate that MC not only express critical effector functions in classic IgE-associated allergic disorders, but also play important roles in host defence against parasites, bacteria and perhaps even viruses. Indeed, it is now clear that MC can contribute to host defence in the context of either acquired or innate immune responses through the release of a myriad of pro-inflammatory and immunoregulatory molecules and the expression of a wide spectrum of surface receptors for cytokines and chemokines. Moreover, there is growing evidence that MC exert distinct nonimmunological functions, playing a relevant role in tissue homeostasis, remodeling and fibrosis as well as in the processes of tissue angiogenesis. In this review, we provide a small insight into the biology of mast cells and their potential implications in human pathology.

  9. Differentiated human stem cells resemble fetal, not adult, β cells.

    PubMed

    Hrvatin, Sinisa; O'Donnell, Charles W; Deng, Francis; Millman, Jeffrey R; Pagliuca, Felicia Walton; DiIorio, Philip; Rezania, Alireza; Gifford, David K; Melton, Douglas A

    2014-02-25

    Human pluripotent stem cells (hPSCs) have the potential to generate any human cell type, and one widely recognized goal is to make pancreatic β cells. To this end, comparisons between differentiated cell types produced in vitro and their in vivo counterparts are essential to validate hPSC-derived cells. Genome-wide transcriptional analysis of sorted insulin-expressing (INS(+)) cells derived from three independent hPSC lines, human fetal pancreata, and adult human islets points to two major conclusions: (i) Different hPSC lines produce highly similar INS(+) cells and (ii) hPSC-derived INS(+) (hPSC-INS(+)) cells more closely resemble human fetal β cells than adult β cells. This study provides a direct comparison of transcriptional programs between pure hPSC-INS(+) cells and true β cells and provides a catalog of genes whose manipulation may convert hPSC-INS(+) cells into functional β cells.

  10. Improving Cell Engraftment in Cardiac Stem Cell Therapy

    PubMed Central

    Xie, Xiaoyun

    2016-01-01

    Myocardial infarction (MI) affects millions of people worldwide. MI causes massive cardiac cell death and heart function decrease. However, heart tissue cannot effectively regenerate by itself. While stem cell therapy has been considered an effective approach for regeneration, the efficacy of cardiac stem cell therapy remains low due to inferior cell engraftment in the infarcted region. This is mainly a result of low cell retention in the tissue and poor cell survival under ischemic, immune rejection and inflammatory conditions. Various approaches have been explored to improve cell engraftment: increase of cell retention using biomaterials as cell carriers; augmentation of cell survival under ischemic conditions by preconditioning cells, genetic modification of cells, and controlled release of growth factors and oxygen; and enhancement of cell survival by protecting cells from excessive inflammation and immune surveillance. In this paper, we review current progress, advantages, disadvantages, and potential solutions of these approaches. PMID:26783405

  11. Nestin+ cells direct inflammatory cell migration in atherosclerosis

    PubMed Central

    del Toro, Raquel; Chèvre, Raphael; Rodríguez, Cristina; Ordóñez, Antonio; Martínez-González, José; Andrés, Vicente; Méndez-Ferrer, Simón

    2016-01-01

    Atherosclerosis is a leading death cause. Endothelial and smooth muscle cells participate in atherogenesis, but it is unclear whether other mesenchymal cells contribute to this process. Bone marrow (BM) nestin+ cells cooperate with endothelial cells in directing monocyte egress to bloodstream in response to infections. However, it remains unknown whether nestin+ cells regulate inflammatory cells in chronic inflammatory diseases, such as atherosclerosis. Here, we show that nestin+ cells direct inflammatory cell migration during chronic inflammation. In Apolipoprotein E (ApoE) knockout mice fed with high-fat diet, BM nestin+ cells regulate the egress of inflammatory monocytes and neutrophils. In the aorta, nestin+ stromal cells increase ∼30 times and contribute to the atheroma plaque. Mcp1 deletion in nestin+ cells—but not in endothelial cells only— increases circulating inflammatory cells, but decreases their aortic infiltration, delaying atheroma plaque formation and aortic valve calcification. Therefore, nestin expression marks cells that regulate inflammatory cell migration during atherosclerosis. PMID:27586429

  12. Characterization of Amniotic Stem Cells

    PubMed Central

    Koike, Chika; Zhou, Kaixuan; Takeda, Yuji; Fathy, Moustafa; Okabe, Motonori; Yoshida, Toshiko; Nakamura, Yukio; Kato, Yukio

    2014-01-01

    Abstract The amnion membrane is developed from embryo-derived cells, and amniotic cells have been shown to exhibit multidifferentiation potential. These cells represent a desirable source for stem cells for a variety of reasons. However, to date very few molecular analyses of amnion-derived cells have been reported, and efficient markers for isolating the stem cells remain unclear. This paper assesses the characterization of amnion-derived cells as stem cells by examining stemness marker expressions for amnion-derived epithelial cells and mesenchymal cells by flow cytometry, immunocytochemistry, and quantitative PCR. Flow cytometry revealed that amnion epithelial cells expressed CD133, CD 271, and TRA-1-60, whereas mecenchymal cells expressed CD44, CD73, CD90, and CD105. Immunohistochemistry showed that both cells expressed the stemness markers Oct3/4, Sox2, Klf4, and SSEA4. Stemness genes' expression in amnion epithelial cells, mesenchymal cells, fibroblast, bone marrow–derived mesenchymal stem cells (MSCs), and induced pluripotent stem cells (iPSCs) was compared by quantitative reverse-transcription polymerase chain reaction (RT-PCR). Amnion-derived epithelial cells and mesenchymal cells expressed Oct3/4, Nanog, and Klf4 more than bone marrow–derived MSCs. The sorted TRA1-60–positive cells expressed Oct3/4, Nanog, and Klf4 more than unsorted cells or TRA1-60–negative cells. TRA1-60 can be a marker for isolating amnion epithelial stem cells. PMID:25068631

  13. Analysing immune cell migration.

    PubMed

    Beltman, Joost B; Marée, Athanasius F M; de Boer, Rob J

    2009-11-01

    The visualization of the dynamic behaviour of and interactions between immune cells using time-lapse video microscopy has an important role in modern immunology. To draw robust conclusions, quantification of such cell migration is required. However, imaging experiments are associated with various artefacts that can affect the estimated positions of the immune cells under analysis, which form the basis of any subsequent analysis. Here, we describe potential artefacts that could affect the interpretation of data sets on immune cell migration. We propose how these errors can be recognized and corrected, and suggest ways to prevent the data analysis itself leading to biased results.

  14. Myeloproliferative neoplasm stem cells.

    PubMed

    Mead, Adam J; Mullally, Ann

    2017-03-23

    Myeloproliferative neoplasms (MPNs) arise in the hematopoietic stem cell (HSC) compartment as a result of the acquisition of somatic mutations in a single HSC that provides a selective advantage to mutant HSC over normal HSC and promotes myeloid differentiation to engender a myeloproliferative phenotype. This population of somatically mutated HSC, which initiates and sustains MPNs, is termed MPN stem cells. In >95% of cases, mutations that drive the development of an MPN phenotype occur in a mutually exclusive manner in 1 of 3 genes: JAK2, CALR, or MPL The thrombopoietin receptor, MPL, is the key cytokine receptor in MPN development, and these mutations all activate MPL-JAK-STAT signaling in MPN stem cells. Despite common biological features, MPNs display diverse disease phenotypes as a result of both constitutional and acquired factors that influence MPN stem cells, and likely also as a result of heterogeneity in the HSC in which MPN-initiating mutations arise. As the MPN clone expands, it exerts cell-extrinsic effects on components of the bone marrow niche that can favor the survival and expansion of MPN stem cells over normal HSC, further sustaining and driving malignant hematopoiesis. Although developed as targeted therapies for MPNs, current JAK2 inhibitors do not preferentially target MPN stem cells, and as a result, rarely induce molecular remissions in MPN patients. As the understanding of the molecular mechanisms underlying the clonal dominance of MPN stem cells advances, this will help facilitate the development of therapies that preferentially target MPN stem cells over normal HSC.

  15. Nanocrystal Solar Cells

    SciTech Connect

    Gur, Ilan

    2006-01-01

    This dissertation presents the results of a research agenda aimed at improving integration and stability in nanocrystal-based solar cells through advances in active materials and device architectures. The introduction of 3-dimensional nanocrystals illustrates the potential for improving transport and percolation in hybrid solar cells and enables novel fabrication methods for optimizing integration in these systems. Fabricating cells by sequential deposition allows for solution-based assembly of hybrid composites with controlled and well-characterized dispersion and electrode contact. Hyperbranched nanocrystals emerge as a nearly ideal building block for hybrid cells, allowing the controlled morphologies targeted by templated approaches to be achieved in an easily fabricated solution-cast device. In addition to offering practical benefits to device processing, these approaches offer fundamental insight into the operation of hybrid solar cells, shedding light on key phenomena such as the roles of electrode-contact and percolation behavior in these cells. Finally, all-inorganic nanocrystal solar cells are presented as a wholly new cell concept, illustrating that donor-acceptor charge transfer and directed carrier diffusion can be utilized in a system with no organic components, and that nanocrystals may act as building blocks for efficient, stable, and low-cost thin-film solar cells.

  16. Microencapsulation Of Living Cells

    NASA Technical Reports Server (NTRS)

    Chang, Manchium; Kendall, James M.; Wang, Taylor G.

    1989-01-01

    In experimental technique, living cells and other biological materials encapsulated within submillimeter-diameter liquid-filled spheres. Sphere material biocompatible, tough, and compliant. Semipermeable, permitting relatively small molecules to move into and out of sphere core but preventing passage of large molecules. New technique promises to make such spherical capsules at high rates and in uniform, controllable sizes. Capsules injected into patient through ordinary hypodermic needle. Promising application for technique in treatment of diabetes. Also used to encapsulate pituitary cells and thyroid hormone adrenocortical cells for treatment of other hormonal disorders, to encapsulate other secreting cells for transplantation, and to package variety of pharmaceutical products and agricultural chemicals for controlled release.

  17. Solar cell radiation handbook

    NASA Technical Reports Server (NTRS)

    Tada, H. Y.; Carter, J. R., Jr.

    1977-01-01

    Solar cell theory cells are manufactured, and how they are modeled mathematically is reviewed. The interaction of energetic charged particle radiation with solar cells is discussed in detail and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Finally, an extensive body of data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence is presented.

  18. Molten salt lithium cells

    DOEpatents

    Raistrick, I.D.; Poris, J.; Huggins, R.A.

    1980-07-18

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400 to 500/sup 0/C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell which may be operated at temperatures between about 100 to 170/sup 0/C. The cell is comprised of an electrolyte, which preferably includes lithium nitrate, and a lithium or lithium alloy electrode.

  19. Molten salt lithium cells

    DOEpatents

    Raistrick, Ian D.; Poris, Jaime; Huggins, Robert A.

    1983-01-01

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400.degree.-500.degree. C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell (10) which may be operated at temperatures between about 100.degree.-170.degree. C. Cell (10) comprises an electrolyte (16), which preferably includes lithium nitrate, and a lithium or lithium alloy electrode (12).

  20. Molten salt lithium cells

    DOEpatents

    Raistrick, Ian D.; Poris, Jaime; Huggins, Robert A.

    1982-02-09

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400.degree.-500.degree. C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell (10) which may be operated at temperatures between about 100.degree.-170.degree. C. Cell (10) comprises an electrolyte (16), which preferably includes lithium nitrate, and a lithium or lithium alloy electrode (12).

  1. Fuel cell technology program

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A fuel cell technology program was established to advance the state-of-the art of hydrogen oxygen fuel cells using low temperature, potassium hydroxide electrolyte technology as the base. Cell and component testing confirmed that low temperature, potassium hydroxide electrolyte technology is compatible with the requirements of the space shuttle Phase B contractors. Testing of the DM-1 powerplant demonstrated all of the important requirements of the shuttle except operating life. Testing also identified DM-1 powerplant life limiting mechanisms; hydrogen pump gear wear and pressurization of the cell stack over its design limits.

  2. Bacterial Cell Mechanics.

    PubMed

    Auer, George K; Weibel, Douglas B

    2017-07-25

    Cellular mechanical properties play an integral role in bacterial survival and adaptation. Historically, the bacterial cell wall and, in particular, the layer of polymeric material called the peptidoglycan were the elements to which cell mechanics could be primarily attributed. Disrupting the biochemical machinery that assembles the peptidoglycan (e.g., using the β-lactam family of antibiotics) alters the structure of this material, leads to mechanical defects, and results in cell lysis. Decades after the discovery of peptidoglycan-synthesizing enzymes, the mechanisms that underlie their positioning and regulation are still not entirely understood. In addition, recent evidence suggests a diverse group of other biochemical elements influence bacterial cell mechanics, may be regulated by new cellular mechanisms, and may be triggered in different environmental contexts to enable cell adaptation and survival. This review summarizes the contributions that different biomolecular components of the cell wall (e.g., lipopolysaccharides, wall and lipoteichoic acids, lipid bilayers, peptidoglycan, and proteins) make to Gram-negative and Gram-positive bacterial cell mechanics. We discuss the contribution of individual proteins and macromolecular complexes in cell mechanics and the tools that make it possible to quantitatively decipher the biochemical machinery that contributes to bacterial cell mechanics. Advances in this area may provide insight into new biology and influence the development of antibacterial chemotherapies.

  3. Fuel cell technology program

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A fuel cell technology program was established to advance the state-of-the-art of hydrogen-oxygen fuel cells using low temperature, potassium hydroxide electrolyte technology as the base. Program tasks are described consisting of baseline cell design and stack testing, hydrogen pump design and testing, and DM-2 powerplant testing and technology extension efforts. A baseline cell configuration capable of a minimum of 2000 hours of life was defined. A 6-cell prototype stack, incorporating most of the scheme cell features, was tested for a total of 10,497 hours. A 6-cell stack incorporating all of the design features was tested. The DM-2 powerplant with a 34 cell stack, an accessory section packaged in the basic configuration anticipated for the space shuttle powerplant and a powerplant control unit, was defined, assembled, and tested. Cells were used in the stack and a drag-type hydrogen pump was installed in the accessory section. A test program was established, in conjunction with NASA/JSC, based on space shuttle orbiter mission. A 2000-hour minimum endurance test and a 5000-hour goal were set and the test started on August 8, 1972. The 2000-hour milestone was completed on November 3, 1972. On 13 March 1973, at the end of the thirty-first simulated seven-day mission and 5072 load hours, the test was concluded, all goals having been met. At this time, the DM-2 was in excellent condition and capable of additional endurance.

  4. T cells in pregnancy.

    PubMed

    Piccinni, Marie-Pierre

    2005-01-01

    Maternal tolerance of the fetal allograft could be the result of the integration of numerous mechanisms promoted by different cells present in the decidua. Decidual macrophages and dendritic cells, which are found in close association with T lymphocytes are the most potent activators of T lymphocyte responses and could play a sentinel function for the immune system, initiating antigen-specific T cell responses to fetal antigens. T cell cytokines produced in response to fetal molecules could have a role in the maintenance or in the failure of pregnancy. The levels of LIF, IL-4, IL-10 and M-CSF produced by decidual T cells of women suffering from unexplained spontaneous abortion are lower than those of normal pregnant women indicating that these cytokines may contribute to the maintenance of pregnancy. T cells from the cumulus oophorus surrounding the preimplantation embryo produce LIF and IL-4. These findings suggest that cytokines produced by maternal T cells create a suitable microenvironment for preimplantation embryo development and maintenance of pregnancy. T cell cytokine profile could be modulated by the hormones present in the microenvironment of T cells: high doses of progesterone present at fetomaternal interface and in the cumulus induce the production of IL-4 and LIF, whereas relaxin induces IFN-gamma production.

  5. Chromophobe cell renal carcinoma.

    PubMed

    Megumi, Y; Nishimura, K

    1998-01-01

    Chromophobe cell renal carcinoma is a recently established subtype of renal cell carcinoma. Herein we report a case of chromophobe cell renal carcinoma in a 67-year-old male patient who occasionally underwent computed tomography. In a microscopic study with hematoxylin and eosin stain, clear eosinophilic cytoplasm, and a moderately atypical nucleus were observed. And it was stained positively by Hale's colloidal iron. Ultrastructurally, the cytoplasm was filled with numerous microvesicles. From these results, this tumor was pathologically diagnosed as chromophobe cell renal carcinoma.

  6. Single cell dynamic phenotyping

    PubMed Central

    Patsch, Katherin; Chiu, Chi-Li; Engeln, Mark; Agus, David B.; Mallick, Parag; Mumenthaler, Shannon M.; Ruderman, Daniel

    2016-01-01

    Live cell imaging has improved our ability to measure phenotypic heterogeneity. However, bottlenecks in imaging and image processing often make it difficult to differentiate interesting biological behavior from technical artifact. Thus there is a need for new methods that improve data quality without sacrificing throughput. Here we present a 3-step workflow to improve dynamic phenotype measurements of heterogeneous cell populations. We provide guidelines for image acquisition, phenotype tracking, and data filtering to remove erroneous cell tracks using the novel Tracking Aberration Measure (TrAM). Our workflow is broadly applicable across imaging platforms and analysis software. By applying this workflow to cancer cell assays, we reduced aberrant cell track prevalence from 17% to 2%. The cost of this improvement was removing 15% of the well-tracked cells. This enabled detection of significant motility differences between cell lines. Similarly, we avoided detecting a false change in translocation kinetics by eliminating the true cause: varied proportions of unresponsive cells. Finally, by systematically seeking heterogeneous behaviors, we detected subpopulations that otherwise could have been missed, including early apoptotic events and pre-mitotic cells. We provide optimized protocols for specific applications and step-by-step guidelines for adapting them to a variety of biological systems. PMID:27708391

  7. [Endothelial cell adhesion molecules].

    PubMed

    Ivanov, A N; Norkin, I A; Puchin'ian, D M; Shirokov, V Iu; Zhdanova, O Iu

    2014-01-01

    The review presents current data concerning the functional role of endothelial cell adhesion molecules belonging to different structural families: integrins, selectins, cadherins, and the immunoglobulin super-family. In this manuscript the regulatory mechanisms and factors of adhesion molecules expression and distribution on the surface of endothelial cells are discussed. The data presented reveal the importance of adhesion molecules in the regulation of structural and functional state of endothelial cells in normal conditions and in pathology. Particular attention is paid to the importance of these molecules in the processes of physiological and pathological angiogenesis, regulation of permeability of the endothelial barrier and cell transmigration.

  8. Hair cell ribbon synapses

    PubMed Central

    Brandt, Andreas; Lysakowski, Anna

    2010-01-01

    Hearing and balance rely on the faithful synaptic coding of mechanical input by the auditory and vestibular hair cells of the inner ear. Mechanical deflection of their stereocilia causes the opening of mechanosensitive channels, resulting in hair cell depolarization, which controls the release of glutamate at ribbon-type synapses. Hair cells have a compact shape with strong polarity. Mechanoelectrical transduction and active membrane turnover associated with stereociliar renewal dominate the apical compartment. Transmitter release occurs at several active zones along the basolateral membrane. The astonishing capability of the hair cell ribbon synapse for temporally precise and reliable sensory coding has been the subject of intense investigation over the past few years. This research has been facilitated by the excellent experimental accessibility of the hair cell. For the same reason, the hair cell serves as an important model for studying presynaptic Ca2+ signaling and stimulus-secretion coupling. In addition to common principles, hair cell synapses differ in their anatomical and functional properties among species, among the auditory and vestibular organs, and among hair cell positions within the organ. Here, we briefly review synaptic morphology and connectivity and then focus on stimulus-secretion coupling at hair cell synapses. PMID:16944206

  9. NK cells and interferons.

    PubMed

    Paolini, Rossella; Bernardini, Giovanni; Molfetta, Rosa; Santoni, Angela

    2015-04-01

    The role of Natural Killer cells in host defense against infections as well as in tumour surveillance has been widely appreciated for a number of years. Upon recognition of "altered" cells, NK cells release the content of cytolytic granules, leading to the death of target cells. Moreover, NK cells are powerful producers of chemokines and cytokines, particularly Interferon-γ (IFN-γ), of which they are the earliest source upon a variety of infections. Despite being armed to fight against pathogens, NK cells become fully functional upon an initial phase of activation that requires the action of several cytokines, including type I IFNs. Type I IFNs are now recognized as key players in antiviral defense and immune regulation, and evidences from both mouse models of disease and in vitro studies support the existence of an alliance between type I IFNs and NK cells to ensure effective protection against viral infections. This review will focus on the role of type I IFNs in regulating NK cell functions to elicit antiviral response and on NK cell-produced IFN-γ beneficial and pathological effects. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Photosynthetic Photovoltaic Cells

    DTIC Science & Technology

    2007-06-21

    PHOTOSYNTHETIC PHOTOVOLTAIC CELLS 5b. GRANT NUMBER F49620-02-1-0399 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER MARC A. BALDO 5e. TASK...building an ’antenna’ on top of a conventional solar cell. Biomimetic organic solar cells operate as follows: The antenna absorbs the light, and acts to...no longer must absorb all the light. Thus, its quantum efficiency can approach 100% potentially doubling the performance of organic solar cells. 15

  11. Raman activated cell sorting.

    PubMed

    Song, Yizhi; Yin, Huabing; Huang, Wei E

    2016-08-01

    Single cell Raman spectra (SCRS) are intrinsic biochemical profiles and 'chemical images' of single cells which can be used to characterise phenotypic changes, physiological states and functions of cells. On the base of SCRS, Raman activated cell sorting (RACS) provides a label-free cell sorting approach, which can link single cells to their chemical or phenotypic profiles. Overcoming naturally weak Raman signals, establishing Raman biomarker as sorting criteria to RACS and improving specific sorting technology are three challenges of developing RACS. Advances on Raman spectroscopy such as stimulated Raman scattering (SRS) and pre-screening helped to increase RACS sorting speed. Entire SCRS can be characterised using pattern recognition methods, and specific Raman bands can be extracted as biomarkers for RACS. Recent advances on cell sorting technologies based on microfluidic device and surface-ejection enable accurate and reliable single cell sorting from complex samples. A high throughput RACS will be achievable in near future by integrating fast Raman detection system such as SRS with microfluidic RACS and Raman activated cell ejection (RACE).

  12. Applications of Cell Microencapsulation.

    PubMed

    Opara, Emmanuel C

    2017-01-01

    The goal of this chapter is to provide an overview of the different purposes for which the cell microencapsulation technology can be used. These include immunoisolation of non-autologous cells used for cell therapy; immobilization of cells for localized (targeted) delivery of therapeutic products to ablate, repair, or regenerate tissue; simultaneous delivery of multiple therapeutic agents in cell therapy; spatial compartmentalization of cells in complex tissue engineering; expansion of cells in culture; and production of different probiotics and metabolites for industrial applications. For each of these applications, specific examples are provided to illustrate how the microencapsulation technology can be utilized to achieve the purpose. However, successful use of the cell microencapsulation technology for whatever purpose will ultimately depend upon careful consideration for the choice of the encapsulating polymers, the method of fabrication (cross-linking) of the microbeads, which affects the permselectivity, the biocompatibility and the mechanical strength of the microbeads as well as environmental parameters such as temperature, humidity, osmotic pressure, and storage solutions.The various applications discussed in this chapter are illustrated in the different chapters of this book and where appropriate relevant images of the microencapsulation products are provided. It is hoped that this outline of the different applications of cell microencapsulation would provide a good platform for tissue engineers, scientists, and clinicians to design novel tissue constructs and products for therapeutic and industrial applications.

  13. Haploid animal cells.

    PubMed

    Wutz, Anton

    2014-04-01

    Haploid genetics holds great promise for understanding genome evolution and function. Much of the work on haploid genetics has previously been limited to microbes, but possibilities now extend to animal species, including mammals. Whereas haploid animals were described decades ago, only very recent advances in culture techniques have facilitated haploid embryonic stem cell derivation in mammals. This article examines the potential use of haploid cells and puts haploid animal cells into a historical and biological context. Application of haploid cells in genetic screening holds promise for advancing the genetic exploration of mammalian genomes.

  14. Beta cell dynamics: beta cell replenishment, beta cell compensation and diabetes.

    PubMed

    Cerf, Marlon E

    2013-10-01

    Type 2 diabetes, characterized by persistent hyperglycemia, arises mostly from beta cell dysfunction and insulin resistance and remains a highly complex metabolic disease due to various stages in its pathogenesis. Glucose homeostasis is primarily regulated by insulin secretion from the beta cells in response to prevailing glycemia. Beta cell populations are dynamic as they respond to fluctuating insulin demand. Beta cell replenishment and death primarily regulate beta cell populations. Beta cells, pancreatic cells, and extra-pancreatic cells represent the three tiers for replenishing beta cells. In rodents, beta cell self-replenishment appears to be the dominant source for new beta cells supported by pancreatic cells (non-beta islet cells, acinar cells, and duct cells) and extra-pancreatic cells (liver, neural, and stem/progenitor cells). In humans, beta cell neogenesis from non-beta cells appears to be the dominant source of beta cell replenishment as limited beta cell self-replenishment occurs particularly in adulthood. Metabolic states of increased insulin demand trigger increased insulin synthesis and secretion from beta cells. Beta cells, therefore, adapt to support their physiology. Maintaining physiological beta cell populations is a strategy for targeting metabolic states of persistently increased insulin demand as in diabetes.

  15. A brief history of T cell help to B cells

    PubMed Central

    Crotty, Shane

    2015-01-01

    In celebration of the 50th anniversary of the discovery of B cells, I take a look back at the history of T cell help to B cells, which was discovered 47 years ago. In addition, I summarize and categorize the distinct molecules that are expressed by CD4+ T cells that constitute ‘help’ to B cells, and particularly the molecules expressed by T follicular helper (TFH) cells, which are the specialized providers of help to B cells. PMID:25677493

  16. A brief history of T cell help to B cells.

    PubMed

    Crotty, Shane

    2015-03-01

    In celebration of the 50th anniversary of the discovery of B cells, I take a look back at the history of T cell help to B cells, which was discovered 47 years ago. In addition, I summarize and categorize the distinct molecules that are expressed by CD4(+) T cells that constitute 'help' to B cells, and particularly the molecules expressed by T follicular helper (TFH) cells, which are the specialized providers of help to B cells.

  17. A three-dimensional flow control concept for single-cell experiments on a microchip. 1. Cell selection, cell retention, cell culture, cell balancing, and cell scanning.

    PubMed

    Peng, Xing Yue; Li, Paul C H

    2004-09-15

    An ideal microchip for single-cell experiments should be able to allow us to culture cells, to select any desired single cell from a group, to retain the cell for convenient cellular signal detection, and to deliver any buffer or reagent directly to the cell at any time during continual detection and observation. Most importantly, any negative impact on the live cell should be minimized. To accomplish all these functions, we developed a three-dimensional liquid flow control concept and employed special liquid flow fields to manipulate and retain a single yeast cell freely in the chip. A zero-speed point was controlled to retain the cell for three-dimensional cell balancing and cell scanning. A dispersive flow delivered reagents at a high speed to very near the cell and provided them to the cell at a low speed. No force stronger than its gravitational force was exerted on the cell, which could be balanced on different positions on an arc-sloping wall, thus minimizing any negative impact on the cell due to strong liquid flows. Specifically, we demonstrate on-chip single-cell culture, cell wall removal, and reagent delivery. Subsequently, single-cell fluorescence detection was performed, and noise filtering and background correction were applied for data processing.

  18. Polarized cells, polarized views: asymmetric cell division in hematopoietic cells.

    PubMed

    Pham, Kim; Sacirbegovic, Faruk; Russell, Sarah M

    2014-01-01

    It has long been recognized that alterations in cell shape and polarity play important roles in coordinating lymphocyte functions. In the last decade, a new aspect of lymphocyte polarity has attracted much attention, termed asymmetric cell division (ACD). ACD has previously been shown to dictate or influence many aspects of development in model organisms such as the worm and the fly, and to be disrupted in disease. Recent observations that ACD also occurs in lymphocytes led to exciting speculations that ACD might influence lymphocyte differentiation and function, and leukemia. Dissecting the role that ACD might play in these activities has not been straightforward, and the evidence to date for a functional role in lymphocyte fate determination has been controversial. In this review, we discuss the evidence to date for ACD in lymphocytes, and how it might influence lymphocyte fate. We also discuss current gaps in our knowledge, and suggest approaches to definitively test the physiological role of ACD in lymphocytes.

  19. Polarized Cells, Polarized Views: Asymmetric Cell Division in Hematopoietic Cells

    PubMed Central

    Pham, Kim; Sacirbegovic, Faruk; Russell, Sarah M.

    2014-01-01

    It has long been recognized that alterations in cell shape and polarity play important roles in coordinating lymphocyte functions. In the last decade, a new aspect of lymphocyte polarity has attracted much attention, termed asymmetric cell division (ACD). ACD has previously been shown to dictate or influence many aspects of development in model organisms such as the worm and the fly, and to be disrupted in disease. Recent observations that ACD also occurs in lymphocytes led to exciting speculations that ACD might influence lymphocyte differentiation and function, and leukemia. Dissecting the role that ACD might play in these activities has not been straightforward, and the evidence to date for a functional role in lymphocyte fate determination has been controversial. In this review, we discuss the evidence to date for ACD in lymphocytes, and how it might influence lymphocyte fate. We also discuss current gaps in our knowledge, and suggest approaches to definitively test the physiological role of ACD in lymphocytes. PMID:24550912

  20. Fuel Cell Demonstration Program

    SciTech Connect

    Gerald Brun

    2006-09-15

    In an effort to promote clean energy projects and aid in the commercialization of new fuel cell technologies the Long Island Power Authority (LIPA) initiated a Fuel Cell Demonstration Program in 1999 with six month deployments of Proton Exchange Membrane (PEM) non-commercial Beta model systems at partnering sites throughout Long Island. These projects facilitated significant developments in the technology, providing operating experience that allowed the manufacturer to produce fuel cells that were half the size of the Beta units and suitable for outdoor installations. In 2001, LIPA embarked on a large-scale effort to identify and develop measures that could improve the reliability and performance of future fuel cell technologies for electric utility applications and the concept to establish a fuel cell farm (Farm) of 75 units was developed. By the end of October of 2001, 75 Lorax 2.0 fuel cells had been installed at the West Babylon substation on Long Island, making it the first fuel cell demonstration of its kind and size anywhere in the world at the time. Designed to help LIPA study the feasibility of using fuel cells to operate in parallel with LIPA's electric grid system, the Farm operated 120 fuel cells over its lifetime of over 3 years including 3 generations of Plug Power fuel cells (Lorax 2.0, Lorax 3.0, Lorax 4.5). Of these 120 fuel cells, 20 Lorax 3.0 units operated under this Award from June 2002 to September 2004. In parallel with the operation of the Farm, LIPA recruited government and commercial/industrial customers to demonstrate fuel cells as on-site distributed generation. From December 2002 to February 2005, 17 fuel cells were tested and monitored at various customer sites throughout Long Island. The 37 fuel cells operated under this Award produced a total of 712,635 kWh. As fuel cell technology became more mature, performance improvements included a 1% increase in system efficiency. Including equipment, design, fuel, maintenance, installation

  1. Stem cell mobilization.

    PubMed

    Cottler-Fox, Michele H; Lapidot, Tsvee; Petit, Isabelle; Kollet, Orit; DiPersio, John F; Link, Dan; Devine, Steven

    2003-01-01

    Successful blood and marrow transplant (BMT), both autologous and allogeneic, requires the infusion of a sufficient number of hematopoietic progenitor/stem cells (HPCs) capable of homing to the marrow cavity and regenerating a full array of hematopoietic cell lineages in a timely fashion. At present, the most commonly used surrogate marker for HPCs is the cell surface marker CD34, identified in the clinical laboratory by flow cytometry. Clinical studies have shown that infusion of at least 2 x 10(6) CD34(+) cells/kg recipient body weight results in reliable engraftment as measured by recovery of adequate neutrophil and platelet counts approximately 14 days after transplant. Recruitment of HPCs from the marrow into the blood is termed mobilization, or, more commonly, stem cell mobilization. In Section I, Dr. Tsvee Lapidot and colleagues review the wide range of factors influencing stem cell mobilization. Our current understanding focuses on chemokines, proteolytic enzymes, adhesion molecules, cytokines and stromal cell-stem cell interactions. On the basis of this understanding, new approaches to mobilization have been designed and are now starting to undergo clinical testing. In Section II, Dr. Michele Cottler-Fox describes factors predicting the ability to mobilize the older patient with myeloma. In addition, clinical approaches to improving collection by individualizing the timing of apheresis and adjusting the volume of blood processed to achieve a desired product are discussed. Key to this process is the daily enumeration of blood CD34(+) cells. Newer methods of enumerating and mobilizing autologous blood HPCs are discussed. In Section III, Dr. John DiPersio and colleagues provide data on clinical results of mobilizing allogeneic donors with G-CSF, GM-CSF and the combination of both as relates to the number and type of cells collected by apheresis. Newer methods of stem cell mobilization as well as the relationship of graft composition on immune reconstitution

  2. Cell-Cell Adhesion and Breast Cancer.

    DTIC Science & Technology

    1998-01-01

    Staging of breast cancer. In: K.I. Bland and E.M. Copeland (eds.), The breast: Comprehensive management of benign and malignant diseases , pp. 313-330... desmosomes . The physical strength of adhesion between two cells is likely to be dependent upon a number of factors, including the number of adhesion

  3. Fuel cells and fuel cell catalysts

    DOEpatents

    Masel, Richard I.; Rice, Cynthia A.; Waszczuk, Piotr; Wieckowski, Andrzej

    2006-11-07

    A direct organic fuel cell includes a formic acid fuel solution having between about 10% and about 95% formic acid. The formic acid is oxidized at an anode. The anode may include a Pt/Pd catalyst that promotes the direct oxidation of the formic acid via a direct reaction path that does not include formation of a CO intermediate.

  4. Wnt-Dependent Control of Cell Polarity in Cultured Cells.

    PubMed

    Runkle, Kristin B; Witze, Eric S

    2016-01-01

    The secreted ligand Wnt5a regulates cell polarity and polarized cell movement during development by signaling through the poorly defined noncanonical Wnt pathway. Cell polarity regulates most aspects of cell behavior including the organization of apical/basolateral membrane domains of epithelial cells, polarized cell divisions along a directional plane, and front rear polarity during cell migration. These characteristics of cell polarity allow coordinated cell movements required for tissue formation and organogenesis during embryonic development. Genetic model organisms have been used to identify multiple signaling pathways including Wnt5a that are required to establish cell polarity and regulate polarized cell behavior. However, the downstream signaling events that regulate these complex cellular processes are still poorly understood. The methods below describe assays to study Wnt5a-induced cell polarity in cultured cells, which may facilitate our understanding of these complex signaling pathways.

  5. Molecular mechanisms controlling the cell cycle in embryonic stem cells.

    PubMed

    Abdelalim, Essam M

    2013-12-01

    Embryonic stem (ES) cells are originated from the inner cell mass of a blastocyst stage embryo. They can proliferate indefinitely, maintain an undifferentiated state (self-renewal), and differentiate into any cell type (pluripotency). ES cells have an unusual cell cycle structure, consists mainly of S phase cells, a short G1 phase and absence of G1/S checkpoint. Cell division and cell cycle progression are controlled by mechanisms ensuring the accurate transmission of genetic information from generation to generation. Therefore, control of cell cycle is a complicated process, involving several signaling pathways. Although great progress has been made on the molecular mechanisms involved in the regulation of ES cell cycle, many regulatory mechanisms remain unknown. This review summarizes the current knowledge about the molecular mechanisms regulating the cell cycle of ES cells and describes the relationship existing between cell cycle progression and the self-renewal.

  6. Single-cell sequencing in stem cell biology.

    PubMed

    Wen, Lu; Tang, Fuchou

    2016-04-15

    Cell-to-cell variation and heterogeneity are fundamental and intrinsic characteristics of stem cell populations, but these differences are masked when bulk cells are used for omic analysis. Single-cell sequencing technologies serve as powerful tools to dissect cellular heterogeneity comprehensively and to identify distinct phenotypic cell types, even within a 'homogeneous' stem cell population. These technologies, including single-cell genome, epigenome, and transcriptome sequencing technologies, have been developing rapidly in recent years. The application of these methods to different types of stem cells, including pluripotent stem cells and tissue-specific stem cells, has led to exciting new findings in the stem cell field. In this review, we discuss the recent progress as well as future perspectives in the methodologies and applications of single-cell omic sequencing technologies.

  7. Crosstalk between stem cell and cell cycle machineries.

    PubMed

    Kareta, Michael S; Sage, Julien; Wernig, Marius

    2015-12-01

    Pluripotent stem cells, defined by an unlimited self-renewal capacity and an undifferentiated state, are best typified by embryonic stem cells. These cells have a unique cell cycle compared to somatic cells as defined by a rapid progression through the cell cycle and a minimal time spent in G1. Recent reports indicate that pluripotency and cell cycle regulation are mechanistically linked. In this review, we discuss the reciprocal co-regulation of these processes, how this co-regulation may prevent differentiation, and how cellular reprogramming can re-establish the unique cell cycle regulation in induced pluripotent stem cells. Copyright © 2015. Published by Elsevier Ltd.

  8. Dedifferentiated adipocyte-derived progeny cells (DFAT cells): Potential stem cells of adipose tissue.

    PubMed

    Wei, Shengjuan; Zan, Linsen; Hausman, Gary J; Rasmussen, Theodore P; Bergen, Werner G; Dodson, Michael V

    2013-07-01

    Analyses of mature adipocytes have shown that they possess a reprogramming ability in vitro, which is associated with dedifferentiation. The subsequent dedifferentiated fat cells (DFAT cells) are multipotent and can differentiate into adipocytes and other cell types as well. Mature adipocytes can be easily obtained by biopsy, and the cloned progeny cells are homogeneous in vitro. Therefore, DFAT cells (a new type of stem cell) may provide an excellent source of cells for tissue regeneration, engineering and disease treatment. The dedifferentiation of mature adipocytes, the multipotent capacity of DFAT cells and comparisons and contrasts with mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPS) are discussed in this review.

  9. Stem cell regulation: Implications when differentiated cells regulate symmetric stem cell division.

    PubMed

    Høyem, Marte Rørvik; Måløy, Frode; Jakobsen, Per; Brandsdal, Bjørn Olav

    2015-09-07

    We use a mathematical model to show that if symmetric stem cell division is regulated by differentiated cells, then changes in the population dynamics of the differentiated cells can lead to changes in the population dynamics of the stem cells. More precisely, the relative fitness of the stem cells can be affected by modifying the death rate of the differentiated cells. This result is interesting because stem cells are less sensitive than differentiated cells to environmental factors, such as medical therapy. Our result implies that stem cells can be manipulated indirectly by medical treatments that target the differentiated cells.

  10. Transparent solar cell module

    NASA Technical Reports Server (NTRS)

    Antonides, G. J.; Dillard, P. A.; Fritz, W. M.; Lott, D. P.

    1979-01-01

    Modified solar cell module uses high transmission glass and adhesives, and heat dissipation to boost power per unit area by 25% (9.84% efficiency based on cell area at 60 C and 100 mW/sq cm flux). Design is suited for automatic production and is potentially more cost effective.

  11. NCAM regulates cell motility.

    PubMed

    Prag, Søren; Lepekhin, Eugene A; Kolkova, Kateryna; Hartmann-Petersen, Rasmus; Kawa, Anna; Walmod, Peter S; Belman, Vadym; Gallagher, Helen C; Berezin, Vladimir; Bock, Elisabeth; Pedersen, Nina

    2002-01-15

    Cell migration is required during development of the nervous system. The regulatory mechanisms for this process, however, are poorly elucidated. We show here that expression of or exposure to the neural cell adhesion molecule (NCAM) strongly affected the motile behaviour of glioma cells independently of homophilic NCAM interactions. Expression of the transmembrane 140 kDa isoform of NCAM (NCAM-140) caused a significant reduction in cellular motility, probably through interference with factors regulating cellular attachment, as NCAM-140-expressing cells exhibited a decreased attachment to a fibronectin substratum compared with NCAM-negative cells. Ectopic expression of the cytoplasmic part of NCAM-140 also inhibited cell motility, presumably via the non-receptor tyrosine kinase p59(fyn) with which NCAM-140 interacts. Furthermore, we showed that the extracellular part of NCAM acted as a paracrine inhibitor of NCAM-negative cell locomotion through a heterophilic interaction with a cell-surface receptor. As we showed that the two N-terminal immunoglobulin modules of NCAM, which are known to bind to heparin, were responsible for this inhibition, we presume that this receptor is a heparan sulfate proteoglycan. A model for the inhibitory effect of NCAM is proposed, which involves competition between NCAM and extracellular components for the binding to membrane-associated heparan sulfate proteoglycan.

  12. "Angular" plasma cell cheilitis.

    PubMed

    da Cunha Filho, Roberto Rheingantz; Tochetto, Lucas Baldissera; Tochetto, Bruno Baldissera; de Almeida, Hiram Larangeira; Lorencette, Nádia Aparecida; Netto, José Fillus

    2014-03-17

    Plasma cell cheilitis is an extremely rare disease, characterized by erythematous-violaceous, ulcerated and asymptomatic plaques, which evolve slowly. The histological characteristics include dermal infiltrate composed of mature plasmocytes. We report a case of Plasma cell angular cheilitis in a 58-year-old male, localized in the lateral oral commissure.

  13. Programmed cell death

    SciTech Connect

    1995-12-31

    The purpose of this conference to provide a multidisciplinary forum for exchange of state-of-the-art information on the role programmed cell death plays in normal development and homeostasis of many organisms. This volume contains abstracts of papers in the following areas: invertebrate development; immunology/neurology; bcl-2 family; biochemistry; programmed cell death in viruses; oncogenesis; vertebrate development; and diseases.

  14. Fuel cell generator

    DOEpatents

    Isenberg, Arnold O.

    1983-01-01

    High temperature solid oxide electrolyte fuel cell generators which allow controlled leakage among plural chambers in a sealed housing. Depleted oxidant and fuel are directly reacted in one chamber to combust remaining fuel and preheat incoming reactants. The cells are preferably electrically arranged in a series-parallel configuration.

  15. Tumor cell metabolism

    PubMed Central

    Romero-Garcia, Susana; Lopez-Gonzalez, Jose Sullivan; B´ez-Viveros, José Luis; Aguilar-Cazares, Dolores

    2011-01-01

    Cancer is a genetic disease that is caused by mutations in oncogenes, tumor suppressor genes and stability genes. The fact that the metabolism of tumor cells is altered has been known for many years. However, the mechanisms and consequences of metabolic reprogramming have just begun to be understood. In this review, an integral view of tumor cell metabolism is presented, showing how metabolic pathways are reprogrammed to satisfy tumor cell proliferation and survival requirements. In tumor cells, glycolysis is strongly enhanced to fulfill the high ATP demands of these cells; glucose carbons are the main building blocks in fatty acid and nucleotide biosynthesis. Glutaminolysis is also increased to satisfy NADPH regeneration, whereas glutamine carbons replenish the Krebs cycle, which produces metabolites that are constantly used for macromolecular biosynthesis. A characteristic feature of the tumor microenvironment is acidosis, which results from the local increase in lactic acid production by tumor cells. This phenomenon is attributed to the carbons from glutamine and glucose, which are also used for lactic acid production. Lactic acidosis also directs the metabolic reprogramming of tumor cells and serves as an additional selective pressure. Finally, we also discuss the role of mitochondria in supporting tumor cell metabolism. PMID:22057267

  16. Cells and Hypotonic Solutions.

    ERIC Educational Resources Information Center

    Bery, Julia

    1985-01-01

    Describes a demonstration designed to help students better understand the response of plant and animal cells to hypotonic solutions. The demonstration uses a balloon inside a flexible, thin-walled cardboard box. Air going in corresponds to water entering by osmosis, and, like real cells, if stretched enough, the balloon will burst. (DH)

  17. Mesangial cell biology

    SciTech Connect

    Abboud, Hanna E.

    2012-05-15

    Mesangial cells originate from the metanephric mesenchyme and maintain structural integrity of the glomerular microvascular bed and mesangial matrix homeostasis. In response to metabolic, immunologic or hemodynamic injury, these cells undergo apoptosis or acquire an activated phenotype and undergo hypertrophy, proliferation with excessive production of matrix proteins, growth factors, chemokines and cytokines. These soluble factors exert autocrine and paracrine effects on the cells or on other glomerular cells, respectively. MCs are primary targets of immune-mediated glomerular diseases such as IGA nephropathy or metabolic diseases such as diabetes. MCs may also respond to injury that primarily involves podocytes and endothelial cells or to structural and genetic abnormalities of the glomerular basement membrane. Signal transduction and oxidant stress pathways are activated in MCs and likely represent integrated input from multiple mediators. Such responses are convenient targets for therapeutic intervention. Studies in cultured MCs should be supplemented with in vivo studies as well as examination of freshly isolated cells from normal and diseases glomeruli. In addition to ex vivo morphologic studies in kidney cortex, cells should be studied in their natural environment, isolated glomeruli or even tissue slices. Identification of a specific marker of MCs should help genetic manipulation as well as selective therapeutic targeting of these cells. Identification of biological responses of MCs that are not mediated by the renin–angiotensin system should help development of novel and effective therapeutic strategies to treat diseases characterized by MC pathology.

  18. Electrochemical cell stack assembly

    DOEpatents

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    2010-06-22

    Multiple stacks of tubular electrochemical cells having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films arranged in parallel on stamped conductive interconnect sheets or ferrules. The stack allows one or more electrochemical cell to malfunction without disabling the entire stack. Stack efficiency is enhanced through simplified gas manifolding, gas recycling, reduced operating temperature and improved heat distribution.

  19. Transparent solar cell module

    NASA Technical Reports Server (NTRS)

    Antonides, G. J.; Dillard, P. A.; Fritz, W. M.; Lott, D. P.

    1979-01-01

    Modified solar cell module uses high transmission glass and adhesives, and heat dissipation to boost power per unit area by 25% (9.84% efficiency based on cell area at 60 C and 100 mW/sq cm flux). Design is suited for automatic production and is potentially more cost effective.

  20. Fuel cells: Operating flexibly

    NASA Astrophysics Data System (ADS)

    Lee, Young Moo

    2016-09-01

    Fuel cells typically function well only in rather limited temperature and humidity ranges. Now, a proton exchange membrane consisting of ion pair complexes is shown to enable improved fuel cell performance under a wide range of conditions that are unattainable with conventional approaches.

  1. Playing the Cell Game.

    ERIC Educational Resources Information Center

    Madrazo, Gerry M., Jr.; Wood, Carol A.

    1980-01-01

    Discusses the use of games to facilitate learning scientific concepts and principles. Describes the Cell Game, which simulates plant and animal cells; the Energy Quest, which requires players to buy property that generates largest amounts of electricity; the Blood Flow Game, which illustrates circulation of blood through the human body. (CS)

  2. Fuel cell market applications

    SciTech Connect

    Williams, M.C.

    1995-12-31

    This is a review of the US (and international) fuel cell development for the stationary power generation market. Besides DOE, GRI, and EPRI sponsorship, the US fuel cell program has over 40% cost-sharing from the private sector. Support is provided by user groups with over 75 utility and other end-user members. Objectives are to develop and demonstrate cost-effective fuel cell power generation which can initially be commercialized into various market applications using natural gas fuel by the year 2000. Types of fuel cells being developed include PAFC (phosphoric acid), MCFC (molten carbonate), and SOFC (solid oxide); status of each is reported. Potential international applications are reviewed also. Fuel cells are viewed as a force in dispersed power generation, distributed power, cogeneration, and deregulated industry. Specific fuel cell attributes are discussed: Fuel cells promise to be one of the most reliable power sources; they are now being used in critical uninterruptible power systems. They need hydrogen which can be generated internally from natural gas, coal gas, methanol landfill gas, or other fuels containing hydrocarbons. Finally, fuel cell development and market applications in Japan are reviewed briefly.

  3. Tilted fuel cell apparatus

    DOEpatents

    Cooper, John F.; Cherepy, Nerine; Krueger, Roger L.

    2005-04-12

    Bipolar, tilted embodiments of high temperature, molten electrolyte electrochemical cells capable of directly converting carbon fuel to electrical energy are disclosed herein. The bipolar, tilted configurations minimize the electrical resistance between one cell and others connected in electrical series. The tilted configuration also allows continuous refueling of carbon fuel.

  4. Cell Maintenance Systems

    NASA Technical Reports Server (NTRS)

    Morrison, D. R.

    1985-01-01

    Living human cells require attachment to a suitable surface and special culture conditions in order to grow. These requirements are modified and amplified when cells are taken into a weightless environment. Special handling and maintenance systems are required for routine laboratory procedures conducted in the Orbiter and in the Spacelab. Methods were developed to maintain cells in special incubators designed for the Orbiter middeck, however, electrophoresis and other experiments require cells to be harvested off of the culture substrate before they can be processed or used. The cell transport assembly (CTA) was flown on STS-8, and results show that improvements are required to maintain adequate numbers of cells in this device longer than 48 hours. The life sciences middeck centrifuge probably can be used, but modifications will be required to transfer cells from the CTA and keep the cells sterile. Automated systems such as the Skylab SO-15 flight hardware and crew operated systems are being evaluated for use on the Space Shuttle, Spacelab, and Space Station research modules.

  5. Langerhans Cells in Vitiligo.

    PubMed

    Narayanan, R B; Lavania, R K; Girdhar, B K

    1986-01-01

    Langerhans cells (LC) were defined by indirect immunofluore-scence using OKT6 monoclonal antibody in the early lesions of 10 untreated vitiligo patients. The distribution and the numbers of OKT6 + epidermal LC in the lesions was similar to that observed in the normal skin. In the dermal infiltrates of some of the lesion, T6 '+ cells were visualized.

  6. Animal cell hydraulics

    PubMed Central

    Charras, Guillaume T.; Mitchison, Timothy J.; Mahadevan, L.

    2009-01-01

    Summary Water is the dominant ingredient of cells and its dynamics are crucial to life. We and others have suggested a physical picture of the cell as a soft, fluid-infiltrated sponge, surrounded by a water-permeable barrier. To understand water movements in an animal cell, we imposed an external, inhomogeneous osmotic stress on cultured cancer cells. This forced water through the membrane on one side, and out on the other. Inside the cell, it created a gradient in hydration, that we visualized by tracking cellular responses using natural organelles and artificially introduced quantum dots. The dynamics of these markers at short times were the same for normal and metabolically poisoned cells, indicating that the cellular responses are primarily physical rather than chemical. Our finding of an internal gradient in hydration is inconsistent with a continuum model for cytoplasm, but consistent with the sponge model, and implies that the effective pore size of the sponge is small enough to retard water flow significantly on time scales (∼10–100 seconds) relevant to cell physiology. We interpret these data in terms of a theoretical framework that combines mechanics and hydraulics in a multiphase poroelastic description of the cytoplasm and explains the experimentally observed dynamics quantitatively in terms of a few coarse-grained parameters that are based on microscopically measurable structural, hydraulic and mechanical properties. Our fluid-filled sponge model could provide a unified framework to understand a number of disparate observations in cell morphology and motility. PMID:19690051

  7. The Constitution by Cell

    ERIC Educational Resources Information Center

    Greenhut, Stephanie; Jones, Megan

    2010-01-01

    On their visit to the National Archives Experience in Washington, D.C., students in Jenni Ashley and Gay Brock's U.S. history classes at the Potomac School in McLean, Virginia, participated in a pilot program called "The Constitution by Cell." Armed with their cell phones, a basic understanding of the Constitution, and a willingness to…

  8. Closed Small Cell Clouds

    Atmospheric Science Data Center

    2013-04-19

    ... (right)   The structure of tightly packed "closed cells" in a layer of marine stratocumulus over the southeastern Pacific Ocean ... into interesting structures such as those shown here. These cells are notably small, with diameters ranging from 10-15 kilometers, instead ...

  9. Cell Phones for Education

    ERIC Educational Resources Information Center

    Roberson, James H.; Hagevik, Rita A.

    2008-01-01

    Cell phones are fast becoming an integral part of students' everyday lives. They are regarded as important companions and tools for personal expression. School-age children are integrating the cell phone as such, and thus placing a high value on them. Educators endeavor to instill in students a high value for education, but often meet with…

  10. PLATINUM AND FUEL CELLS

    EPA Science Inventory

    Platinum requirements for fuel cell vehicles (FCVS) have been identified as a concern and possible problem with FCV market penetration. Platinum is a necessary component of the electrodes of fuel cell engines that power the vehicles. The platinum is deposited on porous electrodes...

  11. Stem Cells in Prostate

    DTIC Science & Technology

    2005-03-01

    disease upon aging, specifically prostate cancer and benign prostatic hyperplasia . In order to study the cell differentiation lineage associated with...specifically prostate cancer and benign prostatic hyperplasia . In order to study the cell differentiation lineage associated with normal and diseased prostate

  12. CEROLYTE FUEL CELL.

    DTIC Science & Technology

    construction of a power plant for space. A 50-watt cerolyte battery will be constructed and a 500-watt fuel - cell power plant will be designed. Research...evaluation of a 500-watt cerolyte fuel - cell power system for space. During the first quarter work has been concentrated in the first two areas.

  13. The Constitution by Cell

    ERIC Educational Resources Information Center

    Greenhut, Stephanie; Jones, Megan

    2010-01-01

    On their visit to the National Archives Experience in Washington, D.C., students in Jenni Ashley and Gay Brock's U.S. history classes at the Potomac School in McLean, Virginia, participated in a pilot program called "The Constitution by Cell." Armed with their cell phones, a basic understanding of the Constitution, and a willingness to…

  14. Fuel Cells for Society

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Through a SBIR contract with Lewis Research Center, ElectroChem, Inc. developed a hydrogen/oxygen fuel cell. The objective for Lewis Research Center's collaboration with ElectroChem was to develop a fuel cell system that could deliver 200-W (minimum) approximately to 10kWh of electrical energy.

  15. PLATINUM AND FUEL CELLS

    EPA Science Inventory

    Platinum requirements for fuel cell vehicles (FCVS) have been identified as a concern and possible problem with FCV market penetration. Platinum is a necessary component of the electrodes of fuel cell engines that power the vehicles. The platinum is deposited on porous electrodes...

  16. Biosensors for Cell Analysis.

    PubMed

    Zhou, Qing; Son, Kyungjin; Liu, Ying; Revzin, Alexander

    2015-01-01

    Biosensors first appeared several decades ago to address the need for monitoring physiological parameters such as oxygen or glucose in biological fluids such as blood. More recently, a new wave of biosensors has emerged in order to provide more nuanced and granular information about the composition and function of living cells. Such biosensors exist at the confluence of technology and medicine and often strive to connect cell phenotype or function to physiological or pathophysiological processes. Our review aims to describe some of the key technological aspects of biosensors being developed for cell analysis. The technological aspects covered in our review include biorecognition elements used for biosensor construction, methods for integrating cells with biosensors, approaches to single-cell analysis, and the use of nanostructured biosensors for cell analysis. Our hope is that the spectrum of possibilities for cell analysis described in this review may pique the interest of biomedical scientists and engineers and may spur new collaborations in the area of using biosensors for cell analysis.

  17. Cell migration, freshly squeezed.

    PubMed

    Welch, Matthew D

    2015-02-12

    Migrating cells exhibit distinct motility modes and can switch between modes based on chemical or physical cues. Liu et al. and Ruprecht et al. now describe how confinement and contractility influence motility mode plasticity and instigate a mode termed stable bleb migration in embryonic and tumor cells.

  18. Red cell membrane disorders.

    PubMed

    Narla, J; Mohandas, N

    2017-05-01

    Significant advances have been made in our understanding of the structural basis for altered cell function in various inherited red cell membrane disorders with reduced red cell survival and resulting hemolytic anemia. The current review summarizes these advances as they relate to defining the molecular and structural basis for disorders involving altered membrane structural organization (hereditary spherocytosis [HS] and hereditary elliptocytosis [HE]) and altered membrane transport function (hereditary overhydrated stomatocytosis and hereditary xerocytosis). Mutations in genes encoding membrane proteins that account for these distinct red cell phenotypes have been identified. These molecular insights have led to improved understanding of the structural basis for altered membrane function in these disorders. Weakening of vertical linkage between the lipid bilayer and spectrin-based membrane skeleton leads to membrane loss in HS. In contrast, weakening of lateral linkages among different skeletal proteins leads to membrane fragmentation and decreased surface area in HE. The degrees of membrane loss and resultant increases in cell sphericity determine the severity of anemia in these two disorders. Splenectomy leads to amelioration of anemia by increasing the circulatory red cell life span of spherocytic red cells that are normally sequestered by the spleen. Disordered membrane cation permeability and resultant increase or decrease in red cell volume account for altered cellular deformability of hereditary overhydrated stomatocytosis and hereditary xerocytosis, respectively. Importantly, splenectomy is not beneficial in these two membrane transport disorders and in fact contraindicated due to severe postsplenectomy thrombotic complications. © 2017 John Wiley & Sons Ltd.

  19. Sickle Cell Trait

    MedlinePlus

    ... Websites About Us Information For… Media Policy Makers Sickle Cell Trait Language: English (US) Español (Spanish) Recommend on Facebook Tweet Share Compartir Get Screened for Sickle Cell Trait Did you know there’s more than one ...

  20. [Acute plasma cell leukemia].

    PubMed

    Monsalbe, V; Domíngues, C; Roa, I; Busel, D; González, S

    1989-01-01

    Plasma Cell Leukemia is a very rare form of plasmocytic dyscrasia, whose clinical and pathological characteristics warrant its recognition as a distinct subentity. We report the case of a 60 years old man who presented a rapidly fatal acute plasma cell leukemia, with multiple osteolytic lesions, hipercalcemia, renal and cardiac failure.

  1. Playing the Cell Game.

    ERIC Educational Resources Information Center

    Madrazo, Gerry M., Jr.; Wood, Carol A.

    1980-01-01

    Discusses the use of games to facilitate learning scientific concepts and principles. Describes the Cell Game, which simulates plant and animal cells; the Energy Quest, which requires players to buy property that generates largest amounts of electricity; the Blood Flow Game, which illustrates circulation of blood through the human body. (CS)

  2. Cells and Hypotonic Solutions.

    ERIC Educational Resources Information Center

    Bery, Julia

    1985-01-01

    Describes a demonstration designed to help students better understand the response of plant and animal cells to hypotonic solutions. The demonstration uses a balloon inside a flexible, thin-walled cardboard box. Air going in corresponds to water entering by osmosis, and, like real cells, if stretched enough, the balloon will burst. (DH)

  3. Basal cell cancer (image)

    MedlinePlus

    ... biopsy is needed to prove the diagnosis of basal cell carcinoma. Treatment varies depending on the size, depth, and location of the cancer. Early treatment by a dermatologist may result in a cure ... is required to watch for new sites of basal cell cancer.

  4. Retinal stem cells and potential cell transplantation treatments.

    PubMed

    Lin, Tai-Chi; Hsu, Chih-Chien; Chien, Ke-Hung; Hung, Kuo-Hsuan; Peng, Chi-Hsien; Chen, Shih-Jen

    2014-11-01

    The retina, histologically composed of ten delicate layers, is responsible for light perception and relaying electrochemical signals to the secondary neurons and visual cortex. Retinal disease is one of the leading clinical causes of severe vision loss, including age-related macular degeneration, Stargardt's disease, and retinitis pigmentosa. As a result of the discovery of various somatic stem cells, advances in exploring the identities of embryonic stem cells, and the development of induced pluripotent stem cells, cell transplantation treatment for retinal diseases is currently attracting much attention. The sources of stem cells for retinal regeneration include endogenous retinal stem cells (e.g., neuronal stem cells, Müller cells, and retinal stem cells from the ciliary marginal zone) and exogenous stem cells (e.g., bone mesenchymal stem cells, adipose-derived stem cells, embryonic stem cells, and induced pluripotent stem cells). The success of cell transplantation treatment depends mainly on the cell source, the timing of cell harvesting, the protocol of cell induction/transplantation, and the microenvironment of the recipient's retina. This review summarizes the different sources of stem cells for regeneration treatment in retinal diseases and surveys the more recent achievements in animal studies and clinical trials. Future directions and challenges in stem cell transplantation are also discussed.

  5. Molecular Mechanisms of HTLV-1 Cell-to-Cell Transmission.

    PubMed

    Gross, Christine; Thoma-Kress, Andrea K

    2016-03-09

    The tumorvirus human T-cell lymphotropic virus type 1 (HTLV-1), a member of the delta-retrovirus family, is transmitted via cell-containing body fluids such as blood products, semen, and breast milk. In vivo, HTLV-1 preferentially infects CD4⁺ T-cells, and to a lesser extent, CD8⁺ T-cells, dendritic cells, and monocytes. Efficient infection of CD4⁺ T-cells requires cell-cell contacts while cell-free virus transmission is inefficient. Two types of cell-cell contacts have been described to be critical for HTLV-1 transmission, tight junctions and cellular conduits. Further, two non-exclusive mechanisms of virus transmission at cell-cell contacts have been proposed: (1) polarized budding of HTLV-1 into synaptic clefts; and (2) cell surface transfer of viral biofilms at virological synapses. In contrast to CD4⁺ T-cells, dendritic cells can be infected cell-free and, to a greater extent, via viral biofilms in vitro. Cell-to-cell transmission of HTLV-1 requires a coordinated action of steps in the virus infectious cycle with events in the cell-cell adhesion process; therefore, virus propagation from cell-to-cell depends on specific interactions between cellular and viral proteins. Here, we review the molecular mechanisms of HTLV-1 transmission with a focus on the HTLV-1-encoded proteins Tax and p8, their impact on host cell factors mediating cell-cell contacts, cytoskeletal remodeling, and thus, virus propagation.

  6. Cell-in-Cell Death Is Not Restricted by Caspase-3 Deficiency in MCF-7 Cells

    PubMed Central

    Wang, Shan; He, Meifang; Li, Linmei; Liang, Zhihua; Zou, Zehong

    2016-01-01

    Purpose Cell-in-cell structures are created by one living cell entering another homotypic or heterotypic living cell, which usually leads to the death of the internalized cell, specifically through caspase-dependent cell death (emperitosis) or lysosome-dependent cell death (entosis). Although entosis has attracted great attention, its occurrence is controversial, because one cell line used in its study (MCF-7) is deficient in caspase-3. Methods We investigated this issue using MCF-7 and A431 cell lines, which often display cell-in-cell invasion, and have different levels of caspase-3 expression. Cell-in-cell death morphology, microstructures, and signaling pathways were compared in the two cell lines. Results Our results confirmed that MCF-7 cells are caspase-3 deficient with a partial deletion in the CASP-3 gene. These cells underwent cell death that lacked typical apoptotic properties after staurosporine treatment, whereas caspase-3-sufficient A431 cells displayed typical apoptosis. The presence of caspase-3 was related neither to the lysosome-dependent nor to the caspase-dependent cell-in-cell death pathway. However, the existence of caspase-3 was associated with a switch from lysosome-dependent cell-in-cell death to the apoptotic cell-in-cell death pathway during entosis. Moreover, cellular hypoxia, mitochondrial swelling, release of cytochrome C, and autophagy were observed in internalized cells during entosis. Conclusion The occurrence of caspase-independent entosis is not a cell-specific process. In addition, entosis actually represents a cellular self-repair system, functioning through autophagy, to degrade damaged mitochondria resulting from cellular hypoxia in cell-in-cell structures. However, sustained autophagy-associated signal activation, without reduction in cellular hypoxia, eventually leads to lysosome-dependent intracellular cell death. PMID:27721872

  7. Photovoltaic solar cell

    DOEpatents

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2015-09-08

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  8. Mast cells and inflammation.

    PubMed

    Frenzel, Laurent; Hermine, Olivier

    2013-03-01

    The prominent role for mast cells in the inflammatory response has been increasingly well documented in recent years. Mast cells not only contribute to maintain homeostasis via degranulation and to generate IgE-mediated allergic reactions, but also sit at a major crossroads for both innate and adaptive immune responses. The part played by mast cells in chronic inflammatory diseases such as rheumatoid arthritis and multiple sclerosis identifies mast cells as a valuable treatment target in these diseases. Tyrosine-kinase inhibitors targeting the c-Kit mast cell receptor have been found effective in treating rheumatoid arthritis, asthma, and multiple sclerosis. When used in combination with other available drugs, tyrosine-kinase inhibitors may improve the therapeutic management of these diseases.

  9. Storing Blood Cells

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The National Cancer Institute worked with Goddard Space Flight Center to propose a solution to the blood-cell freezing problem. White blood cells and bone marrow are stored for future use by leukemia patients as a result of Goddard and Jet Propulsion Laboratory expertise in electronics and cryogenics. White blood cell and bone marrow bank established using freezing unit. Freezing unit monitors temperature of cells themselves. Thermocouple placed against polyethylene container relays temperature signals to an electronic system which controls small heaters located outside container. Heaters allow liquid nitrogen to circulate at constant temperature and maintain consistent freezing rate. Ability to freeze, store, and thaw white cells and bone marrow without damage is important in leukemia treatment.

  10. Normal Untreated Jurkat Cells

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Biomedical research offers hope for a variety of medical problems, from diabetes to the replacement of damaged bone and tissues. Bioreactors, which are used to grow cells and tissue cultures, play a major role in such research and production efforts. The objective of the research was to define a way to differentiate between effects due to microgravity and those due to possible stress from non-optimal spaceflight conditions. These Jurkat cells, a human acute T-cell leukemia was obtained to evaluate three types of potential experimental stressors: a) Temperature elevation; b) Serum starvation; and c) Centrifugal force. The data from previous spaceflight experiments showed that actin filaments and cell shape are significantly different for the control. These normal cells serve as the baseline for future spaceflight experiments.

  11. Dental pulp stem cells

    PubMed Central

    Ashri, Nahid Y.; Ajlan, Sumaiah A.; Aldahmash, Abdullah M.

    2015-01-01

    Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from their relative accessibility and pleasant handling properties. The purpose of this article is to review the biological principles of periodontal tissue engineering, along with the challenges facing the development of a consistent and clinically relevant tissue regeneration platform. This article includes an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors. PMID:26620980

  12. Normal Untreated Jurkat Cells

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Biomedical research offers hope for a variety of medical problems, from diabetes to the replacement of damaged bone and tissues. Bioreactors, which are used to grow cells and tissue cultures, play a major role in such research and production efforts. The objective of the research was to define a way to differentiate between effects due to microgravity and those due to possible stress from non-optimal spaceflight conditions. These Jurkat cells, a human acute T-cell leukemia was obtained to evaluate three types of potential experimental stressors: a) Temperature elevation; b) Serum starvation; and c) Centrifugal force. The data from previous spaceflight experiments showed that actin filaments and cell shape are significantly different for the control. These normal cells serve as the baseline for future spaceflight experiments.

  13. PEM regenerative fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, Larry L.; Laconti, Anthony B.; Mccatty, Stephen A.

    1993-01-01

    This paper will update the progress in developing electrocatalyst systems and electrode structures primarily for the positive electrode of single-unit solid polymer proton exchange membrane (PEM) regenerative fuel cells. The work was done with DuPont Nafion 117 in complete fuel cells (40 sq cm electrodes). The cells were operated alternately in fuel cell mode and electrolysis mode at 80 C. In fuel cell mode, humidified hydrogen and oxygen were supplied at 207 kPa (30 psi); in electrolysis mode, water was pumped over the positive electrode and the gases were evolved at ambient pressure. Cycling data will be presented for Pt-Ir catalysts and limited bifunctional data will be presented for Pt, Ir, Ru, Rh, and Na(x)Pt3O4 catalysts as well as for electrode structure variations.

  14. Single-Cell Metabolomics.

    PubMed

    Emara, Samy; Amer, Sara; Ali, Ahmed; Abouleila, Yasmine; Oga, April; Masujima, Tsutomu

    2017-01-01

    The dynamics of a cell is always changing. Cells move, divide, communicate, adapt, and are always reacting to their surroundings non-synchronously. Currently, single-cell metabolomics has become the leading field in understanding the phenotypical variations between them, but sample volumes, low analyte concentrations, and validating gentle sample techniques have proven great barriers toward achieving accurate and complete metabolomics profiling. Certainly, advanced technologies such as nanodevices and microfluidic arrays are making great progress, and analytical techniques, such as matrix-assisted laser desorption ionization (MALDI), are gaining popularity with high-throughput methodology. Nevertheless, live single-cell mass spectrometry (LCSMS) values the sample quality and precision, turning once theoretical speculation into present-day applications in a variety of fields, including those of medicine, pharmaceutical, and agricultural industries. While there is still room for much improvement, it is clear that the metabolomics field is progressing toward analysis and discoveries at the single-cell level.

  15. Cell manipulation in microfluidics.

    PubMed

    Yun, Hoyoung; Kim, Kisoo; Lee, Won Gu

    2013-06-01

    Recent advances in the lab-on-a-chip field in association with nano/microfluidics have been made for new applications and functionalities to the fields of molecular biology, genetic analysis and proteomics, enabling the expansion of the cell biology field. Specifically, microfluidics has provided promising tools for enhancing cell biological research, since it has the ability to precisely control the cellular environment, to easily mimic heterogeneous cellular environment by multiplexing, and to analyze sub-cellular information by high-contents screening assays at the single-cell level. Various cell manipulation techniques in microfluidics have been developed in accordance with specific objectives and applications. In this review, we examine the latest achievements of cell manipulation techniques in microfluidics by categorizing externally applied forces for manipulation: (i) optical, (ii) magnetic, (iii) electrical, (iv) mechanical and (v) other manipulations. We furthermore focus on history where the manipulation techniques originate and also discuss future perspectives with key examples where available.

  16. Neural stem cells.

    PubMed

    Kennea, Nigel L; Mehmet, Huseyin

    2002-07-01

    Neural stem cells (NSCs) have the ability to self-renew, and are capable of differentiating into neurones, astrocytes and oligodendrocytes. Such cells have been isolated from the developing brain and more recently from the adult central nervous system. This review aims to provide an overview of the current research in this evolving area. There is now increasing knowledge of the factors controlling the division and differentiation of NSCs during normal brain development. In addition, the cues for differentiation in vitro, and the possibility of transdifferentiation are reviewed. The discovery of these cells in the adult brain has encouraged research into their role during neurogenesis in the normal mature brain and after injury. Lastly other sources of neural precursors are discussed, and the potential for stem cells to be used in cell replacement therapy for brain injury or degenerative brain diseases with a particular emphasis on cerebral ischaemia and Parkinson's disease. Copyright 2002 John Wiley & Sons, Ltd.

  17. [Stem cell colloquy: conclusion].

    PubMed

    Tubiana, Maurice

    2002-10-01

    The stem cell data presented and discussed during the symposium raise the hope that important medical progress can be made in several fields: neuro-degenerative diseases, those linked to cellular deficit, some aspects of aging linked to cellular degeneration, and the treatment of cancers that may harm normal tissues at risk of being infiltrated by malignant cells. Three main types of stem cells are available. (i) Those present in normal adult tissue: contrary to what was believed, some data suggest that certain adult stem cells have a great plasticity (they can differentiate into cells different from those in tissues from which they were taken) and can proliferate in vitro without losing their properties. Nevertheless, their use faces several obstacles: in ill or elderly subjects, then these cells can be limited in number or not multiply well in vitro. In this case, auto-grafting of the cells cannot be used. They must be sought in another subject, and allo-grafting causes difficult and sometimes insoluble problems of immunological tolerance. (ii) Embryonic stem cells from surplus human embryos, obtained by in vitro fertilisation, which the parents decide not to use: these cells have a great potential for proliferation and differentiation, but can also encounter problems of immunological intolerance. (iii) Cells obtained from cell nuclear transfer in oocytes: these cells are well tolerated, since they are genetically and immunologically identical to those of the host. All types of stem cells can be obtained with them. However, they do present problems. For obtaining them, female oocytes are needed, which could lead to their commercialization. Moreover, the first steps for obtaining these cells are identical to those used in reproductive cloning. It therefore appears that each type of cell raises difficult scientific and practical problems. More research is needed to overcome these obstacles and to determine which type of stem cell constitutes the best solution for

  18. Whole-cell biocomputing

    NASA Technical Reports Server (NTRS)

    Simpson, M. L.; Sayler, G. S.; Fleming, J. T.; Applegate, B.

    2001-01-01

    The ability to manipulate systems on the molecular scale naturally leads to speculation about the rational design of molecular-scale machines. Cells might be the ultimate molecular-scale machines and our ability to engineer them is relatively advanced when compared with our ability to control the synthesis and direct the assembly of man-made materials. Indeed, engineered whole cells deployed in biosensors can be considered one of the practical successes of molecular-scale devices. However, these devices explore only a small portion of cellular functionality. Individual cells or self-organized groups of cells perform extremely complex functions that include sensing, communication, navigation, cooperation and even fabrication of synthetic nanoscopic materials. In natural systems, these capabilities are controlled by complex genetic regulatory circuits, which are only partially understood and not readily accessible for use in engineered systems. Here, we focus on efforts to mimic the functionality of man-made information-processing systems within whole cells.

  19. Phalange Tactile Load Cell

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert (Inventor); Griffith, Bryan Kristian (Inventor)

    2010-01-01

    A tactile load cell that has particular application for measuring the load on a phalange in a dexterous robot system. The load cell includes a flexible strain element having first and second end portions that can be used to mount the load cell to the phalange and a center portion that can be used to mount a suitable contact surface to the load cell. The strain element also includes a first S-shaped member including at least three sections connected to the first end portion and the center portion and a second S-shaped member including at least three sections coupled to the second end portion and the center portion. The load cell also includes eight strain gauge pairs where each strain gauge pair is mounted to opposing surfaces of one of the sections of the S-shaped members where the strain gauge pairs provide strain measurements in six-degrees of freedom.

  20. Cell-Size Control

    PubMed Central

    Amodeo, Amanda A.; Skotheim, Jan M.

    2015-01-01

    Cells of a given type maintain a characteristic cell size to function efficiently in their ecological or organismal context. They achieve this through the regulation of growth rates or by actively sensing size and coupling this signal to cell division. We focus this review on potential size-sensing mechanisms, including geometric, external cue, and titration mechanisms. Mechanisms that titrate proteins against DNA are of particular interest because they are consistent with the robust correlation of DNA content and cell size. We review the literature, which suggests that titration mechanisms may underlie cell-size sensing in Xenopus embryos, budding yeast, and Escherichia coli, whereas alternative mechanisms may function in fission yeast. PMID:26254313

  1. Physics of adherent cells

    NASA Astrophysics Data System (ADS)

    Schwarz, Ulrich S.; Safran, Samuel A.

    2013-07-01

    One of the most unique physical features of cell adhesion to external surfaces is the active generation of mechanical force at the cell-material interface. This includes pulling forces generated by contractile polymer bundles and networks, and pushing forces generated by the polymerization of polymer networks. These forces are transmitted to the substrate mainly by focal adhesions, which are large, yet highly dynamic adhesion clusters. Tissue cells use these forces to sense the physical properties of their environment and to communicate with each other. The effect of forces is intricately linked to the material properties of cells and their physical environment. Here a review is given of recent progress in our understanding of the role of forces in cell adhesion from the viewpoint of theoretical soft matter physics and in close relation to the relevant experiments.

  2. Whole-cell biocomputing

    NASA Technical Reports Server (NTRS)

    Simpson, M. L.; Sayler, G. S.; Fleming, J. T.; Applegate, B.

    2001-01-01

    The ability to manipulate systems on the molecular scale naturally leads to speculation about the rational design of molecular-scale machines. Cells might be the ultimate molecular-scale machines and our ability to engineer them is relatively advanced when compared with our ability to control the synthesis and direct the assembly of man-made materials. Indeed, engineered whole cells deployed in biosensors can be considered one of the practical successes of molecular-scale devices. However, these devices explore only a small portion of cellular functionality. Individual cells or self-organized groups of cells perform extremely complex functions that include sensing, communication, navigation, cooperation and even fabrication of synthetic nanoscopic materials. In natural systems, these capabilities are controlled by complex genetic regulatory circuits, which are only partially understood and not readily accessible for use in engineered systems. Here, we focus on efforts to mimic the functionality of man-made information-processing systems within whole cells.

  3. Solar cell radiation handbook

    NASA Technical Reports Server (NTRS)

    Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

    1982-01-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  4. Donor cell leukemia.

    PubMed

    Ruiz-Arguelles, Alejandro

    2012-04-01

    Minimal residual disease refers to the tumour cells that are still present in a given patient after completion of a therapeutic scheme. The demonstration and quantification of residual neoplastic cells has a crucial impact in clinical decision making, for it might prompt continuation of treatment, while the absence of such cells might serve as evidence to withdraw therapy. Therefore, both sensitivity and specificity of the methods used to unravel residual neoplastic cells must be highly reliable and robust. Flow cytometry has been widely used for this purpose, and its clinical performance depends mainly on the criteria of interpretation, rather than in the technique by itself; molecular biology techniques have proved to be highly sensitive and specific but unfortunately they cannot be used in all patients or in all types of leukemia. Finally, the development of donor cell leukemia in transplanted patients, might mimic residual disease and add more confusion to an already controversial issue. These topics are discussed in this paper.

  5. Mast cell leukemia.

    PubMed

    Georgin-Lavialle, Sophie; Lhermitte, Ludovic; Dubreuil, Patrice; Chandesris, Marie-Olivia; Hermine, Olivier; Damaj, Gandhi

    2013-02-21

    Mast cell leukemia (MCL) is a very rare form of aggressive systemic mastocytosis accounting for < 1% of all mastocytosis. It may appear de novo or secondary to previous mastocytosis and shares more clinicopathologic aspects with systemic mastocytosis than with acute myeloid leukemia. Symptoms of mast cell activation-involvement of the liver, spleen, peritoneum, bones, and marrow-are frequent. Diagnosis is based on the presence of ≥ 20% atypical mast cells in the marrow or ≥ 10% in the blood; however, an aleukemic variant is frequently encountered in which the number of circulating mast cells is < 10%. The common phenotypic features of pathologic mast cells encountered in most forms of mastocytosis are unreliable in MCL. Unexpectedly, non-KIT D816V mutations are frequent and therefore, complete gene sequencing is necessary. Therapy usually fails and the median survival time is < 6 months. The role of combination therapies and bone marrow transplantation needs further investigation.

  6. Cell Radiation Experiment System

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R.

    2010-01-01

    The cell radiation experiment system (CRES) is a perfused-cell culture apparatus, within which cells from humans or other animals can (1) be maintained in homeostasis while (2) being exposed to ionizing radiation during controlled intervals and (3) being monitored to determine the effects of radiation and the repair of radiation damage. The CRES can be used, for example, to determine effects of drug, radiation, and combined drug and radiation treatments on both normal and tumor cells. The CRES can also be used to analyze the effects of radiosensitive or radioprotectant drugs on cells subjected to radiation. The knowledge gained by use of the CRES is expected to contribute to the development of better cancer treatments and of better protection for astronauts, medical-equipment operators, and nuclear-power-plant workers, and others exposed frequently to ionizing radiation.

  7. Polymer solar cells

    NASA Astrophysics Data System (ADS)

    Li, Gang; Zhu, Rui; Yang, Yang

    2012-03-01

    Recent progress in the development of polymer solar cells has improved power-conversion efficiencies from 3% to almost 9%. Based on semiconducting polymers, these solar cells are fabricated from solution-processing techniques and have unique prospects for achieving low-cost solar energy harvesting, owing to their material and manufacturing advantages. The potential applications of polymer solar cells are broad, ranging from flexible solar modules and semitransparent solar cells in windows, to building applications and even photon recycling in liquid-crystal displays. This Review covers the scientific origins and basic properties of polymer solar cell technology, material requirements and device operation mechanisms, while also providing a synopsis of major achievements in the field over the past few years. Potential future developments and the applications of this technology are also briefly discussed.

  8. Cell Cycle and Cell Size Dependent Gene Expression Reveals Distinct Subpopulations at Single-Cell Level

    PubMed Central

    Dolatabadi, Soheila; Candia, Julián; Akrap, Nina; Vannas, Christoffer; Tesan Tomic, Tajana; Losert, Wolfgang; Landberg, Göran; Åman, Pierre; Ståhlberg, Anders

    2017-01-01

    Cell proliferation includes a series of events that is tightly regulated by several checkpoints and layers of control mechanisms. Most studies have been performed on large cell populations, but detailed understanding of cell dynamics and heterogeneity requires single-cell analysis. Here, we used quantitative real-time PCR, profiling the expression of 93 genes in single-cells from three different cell lines. Individual unsynchronized cells from three different cell lines were collected in different cell cycle phases (G0/G1 – S – G2/M) with variable cell sizes. We found that the total transcript level per cell and the expression of most individual genes correlated with progression through the cell cycle, but not with cell size. By applying the random forests algorithm, a supervised machine learning approach, we show how a multi-gene signature that classifies individual cells into their correct cell cycle phase and cell size can be generated. To identify the most predictive genes we used a variable selection strategy. Detailed analysis of cell cycle predictive genes allowed us to define subpopulations with distinct gene expression profiles and to calculate a cell cycle index that illustrates the transition of cells between cell cycle phases. In conclusion, we provide useful experimental approaches and bioinformatics to identify informative and predictive genes at the single-cell level, which opens up new means to describe and understand cell proliferation and subpopulation dynamics. PMID:28179914

  9. Interferon-alpha and dexamethasone inhibit adhesion of T cells to endothelial cells and synovial cells

    PubMed Central

    Eguchi, K.; Kawakami, A.; Nakashima, M.; Ida, H.; Sakito, S.; Matsuoka, N.; Terada, K.; Sakai, M.; Kawabe, Y.; Fukuda, T.; Ishimaru, T.; Kurouji, K.; Fujita, N.; Aoyagi, T.; Maeda, K.; Nagataki, S.

    1992-01-01

    We investigated whether interferon-gamma (IFN-γ), interferon-alpha (IFN-α) and glucocorticoids affected the adhesion of T cells to human umbilical endothelial cells or human synovial cells. About 30% of peripheral blood T cells could bind to unstimulated endothelial cells, but only a few T cells could bind to unstimulated synovial cells. When both endothelial cells and synovial cells were cultured with recombinant IFN-γ (rIFN-γ), the percentage of T cell binding to both types of cells increased in a dose-dependent manner. rIFN-α and dexamethasone blocked the T cell binding to unstimulated endothelial cells. Furthermore, rIFN-α and dexamethasone suppressed T cell binding to both endothelial cells and synovial cells stimulated by IFN-γ, and also inhibited intercellular adhesion molecule-1 (ICAM-1) expression on both endothelial cells and synovial cells stimulated by IFN-γ. These results suggest that IFN-α and glucocorticoids may inhibit T cell binding to endothelial cells or synovial cells by modulating adhesion molecule expression on these cells. PMID:1606729

  10. Cell cycle regulation in human embryonic stem cells: links to adaptation to cell culture.

    PubMed

    Barta, Tomas; Dolezalova, Dasa; Holubcova, Zuzana; Hampl, Ales

    2013-03-01

    Cell cycle represents not only a tightly orchestrated mechanism of cell replication and cell division but it also plays an important role in regulation of cell fate decision. Particularly in the context of pluripotent stem cells or multipotent progenitor cells, regulation of cell fate decision is of paramount importance. It has been shown that human embryonic stem cells (hESCs) show unique cell cycle characteristics, such as short doubling time due to abbreviated G1 phase; these properties change with the onset of differentiation. This review summarizes the current understanding of cell cycle regulation in hESCs. We discuss cell cycle properties as well as regulatory machinery governing cell cycle progression of undifferentiated hESCs. Additionally, we provide evidence that long-term culture of hESCs is accompanied by changes in cell cycle properties as well as configuration of several cell cycle regulatory molecules.

  11. Induction of Germ Cell-like Cells from Porcine Induced Pluripotent Stem Cells

    PubMed Central

    Wang, Hanning; Xiang, Jinzhu; Zhang, Wei; Li, Junhong; Wei, Qingqing; Zhong, Liang; Ouyang, Hongsheng; Han, Jianyong

    2016-01-01

    The ability to generate germ cells from pluripotent stem cells (PSCs) is valuable for human regenerative medicine and animal breeding. Germ cell-like cells (GCLCs) have been differentiated from mouse and human PSCs, but not from porcine PSCs, which are considered an ideal model for stem cell applications. Here, we developed a defined culture system for the induction of primordial germ cell-like cells (PGCLCs) from porcine induced PSCs (piPSCs). The identity of the PGCLCs was characterized by observing cell morphology, detecting germ cell marker gene expression and evaluating epigenetic properties. PGCLCs could further differentiate into spermatogonial stem cell-like cells (SSCLCs) in vitro. Importantly, meiosis occurred during SSCLC induction. Xenotransplantation of GCLCs into seminiferous tubules of infertile immunodeficient mice resulted in immunohistochemically identifiable germ cells in vivo. Overall, our study provides a feasible strategy for directing piPSCs to the germ cell fate and lays a foundation for exploring germ cell development mechanisms. PMID:27264660

  12. Mesenchymal stromal cell cryopreservation.

    PubMed

    Renzi, Sabrina; Lombardo, Tina; Dotti, Silvia; Dessì, Sara S; De Blasio, Pasquale; Ferrari, Maura

    2012-06-01

    The advent of stem cells and stem cell-based therapies for specific diseases requires particular knowledge of laboratory procedures, which not only guarantee the continuous production of cells, but also provide them an identity and integrity as close as possible to their origin. Their cryopreservation at temperatures below -80°C and typically below -140°C is of paramount importance. This target can be achieved by incorporating high molar concentrations of cryoprotectant mixtures that preserve cells from deleterious ice crystal formation. Usually, dimethyl sulfoxide (DMSO) and animal proteins are used as protectant reagents, but unexpected changes in stem cell fate and downstream toxicity effects have been reported, limiting their wide use in clinical settings. In scientific reviews, there are not much data regarding viability of mesenchymal stromal cells (MSCs) after the freezing/thawing process. During our routine analysis, a poor resistance to cryopreservation of these cells was observed, as well as their weak ability to replicate. This is an important point in the study of MSCs; moreover, it represents a limit for preservation and long-term storage. For this reason, MSCs isolated from equine, ovine, and rodent bone marrow and equine adipose tissue were compared using different cryopreservation solutions for this study of vitality. Our findings showed the best results regarding cell viability using a solution of fetal bovine serum with addition of 10% DMSO. In particular, we noted an increase in survival of equine bone marrow MSCs. This parameter has been evaluated by Trypan blue staining at fixed times (0, 24, and 48 hours post-thaw). This result highlights the fact that equine bone marrow MSCs are the frailest we analyzed. Therefore, it could be useful to delve further into this topic in order to improve the storage possibility for these cells and their potential use in cell-based therapies.

  13. Single Cell Isolation and Analysis

    PubMed Central

    Hu, Ping; Zhang, Wenhua; Xin, Hongbo; Deng, Glenn

    2016-01-01

    Individual cell heterogeneity within a population can be critical to its peculiar function and fate. Subpopulations studies with mixed mutants and wild types may not be as informative regarding which cell responds to which drugs or clinical treatments. Cell to cell differences in RNA transcripts and protein expression can be key to answering questions in cancer, neurobiology, stem cell biology, immunology, and developmental biology. Conventional cell-based assays mainly analyze the average responses from a population of cells, without regarding individual cell phenotypes. To better understand the variations from cell to cell, scientists need to use single cell analyses to provide more detailed information for therapeutic decision making in precision medicine. In this review, we focus on the recent developments in single cell isolation and analysis, which include technologies, analyses and main applications. Here, we summarize the historical background, limitations, applications, and potential of single cell isolation technologies. PMID:27826548

  14. High efficiency solar cell processing

    NASA Technical Reports Server (NTRS)

    Ho, F.; Iles, P. A.

    1985-01-01

    At the time of writing, cells made by several groups are approaching 19% efficiency. General aspects of the processing required for such cells are discussed. Most processing used for high efficiency cells is derived from space-cell or concentrator cell technology, and recent advances have been obtained from improved techniques rather than from better understanding of the limiting mechanisms. Theory and modeling are fairly well developed, and adequate to guide further asymptotic increases in performance of near conventional cells. There are several competitive cell designs with promise of higher performance ( 20%) but for these designs further improvements are required. The available cell processing technology to fabricate high efficiency cells is examined.

  15. Reversing breast cancer stem cell into breast somatic stem cell.

    PubMed

    Wijaya, L; Agustina, D; Lizandi, A O; Kartawinata, M M; Sandra, F

    2011-02-01

    Stem cells have an important role in cell biology, allowing tissues to be renewed by freshly created cells throughout their lifetime. The specific micro-environment of stem cells is called stem cell niche; this environment influences the development of stem cells from quiescence through stages of differentiation. Recent advance researches have improved the understanding of the cellular and molecular components of the micro-environment--or niche--that regulates stem cells. We point out an important trend to the study of niche activity in breast cancers. Breast cancer has long been known to conserve a heterogeneous population of cells. While the majority of cells that make up tumors are destined to differentiate and eventually stop dividing, only minority populations of cells, termed cancer stem cell, possess extensive self renewal capability. These cancer stem cells possess characteristics of both stem cells and cancer cells. Breast cancer stem cells reversal to breast somatic stem cells offer a new therapy, that not only can stop the spread of breast cancer cells, but also can differentiate breast cancer stem cells into normal breast somatic stem cells. These can replace damaged breast tissue. Nevertheless, the complexity of realizing this therapy approach needs further research.

  16. Dedifferentiation of committed epithelial cells into stem cells in vivo

    PubMed Central

    Tata, Purushothama Rao; Mou, Hongmei; Pardo-Saganta, Ana; Zhao, Rui; Prabhu, Mythili; Prabhu, Mythili; Law, Brandon M.; Vinarsky, Vladimir; Cho, Josalyn L.; Breton, Sylvie; Sahay, Amar; Medoff, Benjamin D.; Rajagopal, Jayaraj

    2014-01-01

    Summary Cellular plasticity contributes to the regenerative capacity of plants, invertebrates, teleost fishes, and amphibians. In vertebrates, differentiated cells are known to revert into replicating progenitors, but these cells do not persist as stable stem cells. We now present evidence that differentiated airway epithelial cells can revert into stable and functional stem cells in vivo. Following the ablation of airway stem cells, we observed a surprising increase in the proliferation of committed secretory cells. Subsequent lineage tracing demonstrated that the luminal secretory cells had dedifferentiated into basal stem cells. Dedifferentiated cells were morphologically indistinguishable from stem cells and they functioned as well as their endogenous counterparts to repair epithelial injury. Indeed, single secretory cells clonally dedifferentiated into multipotent stem cells when they were cultured ex vivo without basal stem cells. In contrast, direct contact with a single basal stem cell was sufficient to prevent secretory cell dedifferentiation. In analogy to classical descriptions of amphibian nuclear reprogramming, the propensity of committed cells to dedifferentiate was inversely correlated to their state of maturity. This capacity of committed cells to dedifferentiate into stem cells may play a more general role in the regeneration of many tissues and in multiple disease states, notably cancer. PMID:24196716

  17. Oscillating Cell Culture Bioreactor

    NASA Technical Reports Server (NTRS)

    Freed, Lisa E.; Cheng, Mingyu; Moretti, Matteo G.

    2010-01-01

    To better exploit the principles of gas transport and mass transport during the processes of cell seeding of 3D scaffolds and in vitro culture of 3D tissue engineered constructs, the oscillatory cell culture bioreactor provides a flow of cell suspensions and culture media directly through a porous 3D scaffold (during cell seeding) and a 3D construct (during subsequent cultivation) within a highly gas-permeable closed-loop tube. This design is simple, modular, and flexible, and its component parts are easy to assemble and operate, and are inexpensive. Chamber volume can be very low, but can be easily scaled up. This innovation is well suited to work with different biological specimens, particularly with cells having high oxygen requirements and/or shear sensitivity, and different scaffold structures and dimensions. The closed-loop changer is highly gas permeable to allow efficient gas exchange during the cell seeding/culturing process. A porous scaffold, which may be seeded with cells, is fixed by means of a scaffold holder to the chamber wall with scaffold/construct orientation with respect to the chamber determined by the geometry of the scaffold holder. A fluid, with/without biological specimens, is added to the chamber such that all, or most, of the air is displaced (i.e., with or without an enclosed air bubble). Motion is applied to the chamber within a controlled environment (e.g., oscillatory motion within a humidified 37 C incubator). Movement of the chamber induces relative motion of the scaffold/construct with respect to the fluid. In case the fluid is a cell suspension, cells will come into contact with the scaffold and eventually adhere to it. Alternatively, cells can be seeded on scaffolds by gel entrapment prior to bioreactor cultivation. Subsequently, the oscillatory cell culture bioreactor will provide efficient gas exchange (i.e., of oxygen and carbon dioxide, as required for viability of metabolically active cells) and controlled levels of fluid

  18. Solid oxide fuel cell generator

    DOEpatents

    Di Croce, A. Michael; Draper, Robert

    1993-11-02

    A solid oxide fuel cell generator has a plenum containing at least two rows of spaced apart, annular, axially elongated fuel cells. An electrical conductor extending between adjacent rows of fuel cells connects the fuel cells of one row in parallel with each other and in series with the fuel cells of the adjacent row.

  19. Low White Blood Cell Count

    MedlinePlus

    Symptoms Low white blood cell count By Mayo Clinic Staff A low white blood cell count (leukopenia) is a decrease in disease-fighting cells ( ... a decrease in a certain type of white blood cell (neutrophil). The definition of low white blood cell ...

  20. 10. ENGINE TEST CELL BUILDING INTERIOR. CELL 4, MOUNTING STAND. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. ENGINE TEST CELL BUILDING INTERIOR. CELL 4, MOUNTING STAND. LOOKING NORTHWEST. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  1. 13. ENGINE TEST CELL BUILDING INTERIOR. EQUIPMENT ROOM SERVING CELLS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. ENGINE TEST CELL BUILDING INTERIOR. EQUIPMENT ROOM SERVING CELLS 2 AND 4. LOOKING SOUTHEAST. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  2. ZINC ROUGHER CELLS ON LEFT, ZINC CLEANER CELLS ON RIGHT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ZINC ROUGHER CELLS ON LEFT, ZINC CLEANER CELLS ON RIGHT, LOOKING NORTH. NOTE ONE STYLE OF DENVER AGITATOR IN LOWER RIGHT CELL. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  3. 11. ENGINE TEST CELL BUILDING INTERIOR. CONTROL ROOM FOR CELLS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. ENGINE TEST CELL BUILDING INTERIOR. CONTROL ROOM FOR CELLS 2 AND 4. LOOKING SOUTHEAST. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  4. View of cell block eight (left), cell block seven, and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of cell block eight (left), cell block seven, and southwest guard tower, looking from cell block eight roof - Eastern State Penitentiary, 2125 Fairmount Avenue, Philadelphia, Philadelphia County, PA

  5. Fuel Cells Vehicle Systems Analysis (Fuel Cell Freeze Investigation)

    SciTech Connect

    Pesaran, A.; Kim, G.; Markel, T.; Wipke, K.

    2005-05-01

    Presentation on Fuel Cells Vehicle Systems Analysis (Fuel Cell Freeze Investigation) for the 2005 Hydrogen, Fuel Cells & Infrastructure Technologies Program Annual Review held in Arlington, Virginia on May 23-26, 2005.

  6. Embryonic stem cells: testing the germ-cell theory.

    PubMed

    Hochedlinger, Konrad

    2011-10-25

    The exact cellular origin of embryonic stem cells remains elusive. Now a new study provides compelling evidence that embryonic stem cells, established under conventional culture conditions, originate from a transient germ-cell state.

  7. Cell block eleven (left) and cell block fifteen, looking from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cell block eleven (left) and cell block fifteen, looking from cell block two into the "Death Row" exercise yard - Eastern State Penitentiary, 2125 Fairmount Avenue, Philadelphia, Philadelphia County, PA

  8. Advanced fuel cell development

    NASA Astrophysics Data System (ADS)

    Pierce, R. D.; Baumert, B.; Claar, T. D.; Fousek, R. J.; Huang, H. S.; Kaun, T. D.; Krumpelt, M.; Minh, N.; Mrazek, F. C.; Poeppel, R. B.

    1985-01-01

    Fuel cell research and development activities at Argonne National Laboratory (ANL) during the period January through March 1984 are described. These efforts have been directed principally toward seeking alternative cathode materials to NiO for molten carbonate fuel cells. Based on an investigation of the thermodynamically stable phases formed under cathode conditions, a number of prospective alternative cathode materials have been identified. From the list of candidates, LiFeO2, Li2MnO3, and ZnO were selected for further investigation. During this quarter, they were doped to promote conductivity and tested for solubility and ion migration in the cell environment. An investigation directed to understanding in cell densification of anode materials was initiated. In addition, calculations were made to evaluate the practicality of controlling sulfur accumulation in molten carbonate fuel cells by bleed off of a portion of the anode gas that could be recycled to the cathode. In addition, a model is being developed to predict the performance of solid oxide fuel cells as a function of cell design and operation.

  9. How Deep Cells Feel

    NASA Astrophysics Data System (ADS)

    Buxboim, Amnon; Eckels, Edward C.; Discher, Dennis E.

    2011-03-01

    Lacking eyes to see and ears to hear, cells can still sense their microenvironment by physically touching and deforming, thus sensing not only their immediate surroundings but also feeling beyond the cell-matrix interface. To elucidate how deeply cells feel we cultured mesenchymal stem cells on gels-made microfilms with controlled elasticity (E) and thickness (h). After 36hrs in culture cells spread area was smaller on thick and on soft than on thin and on stiff films, respectively, and correlated with nuclei morphology. Transition in spread area was obtained at <5 microns gel thickness. Transcription levels of Lamin-A predominantly decreased with E and in a similar fashion to Lamin-A expression levels increased with h. RNA levels of histones and of chromatin-remodeling enzymes were similar for stiff gels and for soft but thin films but suppression of cell contractility resulted in transcriptional profiles that were uncorrelated with matrix-emerging cues. We conclude that cells actively sense up to 20 microns into soft, adipose-like matrix. Cellular response to E and h includes cytoskeletal reorganization, NE remodeling with evidence of coupling between matrix-emerging signals and regulation of gene expression

  10. The redoubtable cell.

    PubMed

    Reynolds, Andrew

    2010-09-01

    The cell theory--the thesis that all life is made up of one or more cells, the fundamental structural and physiological unit-is one of the most celebrated achievements of modern biological science. And yet from its very inception in the nineteenth century it has faced repeated criticism from some biologists. Why do some continue to criticize the cell theory, and how has it managed nevertheless to keep burying its undertakers? The answers to these questions reveal the complex nature of the cell theory and the cell concept on which it is based. Like other scientific 'laws', the assertion that all living things are made of cells purchases its universality at the expense of abstraction. If, however, this law is regarded merely as a widely applicable empirical generalization with notable exceptions, it still remains too important to discard. Debate about whether the cell or the organism standpoint provides the more correct account of anatomical, physiological, and developmental facts illustrates the tension between our attempts to express the truth about reality in conceptual terms conducive to a unified human understanding. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Lung Epithelial Progenitor Cells

    PubMed Central

    Rawlins, Emma L.

    2008-01-01

    The current enthusiasm for stem cell research stems from the hope that damaged or diseased tissues may one day be repaired through the manipulation of endogenous or exogenous stem cells. The postnatal human respiratory system is highly accessible and provides unique opportunities for the application of such techniques. Several putative adult lung epithelial stem cells have been identified in the mouse model system. However, their in vivo capabilities to contribute to different lineages, and their control mechanisms, remain unclear. If stem cell–based therapies are to be successful in the lung, it is vitally important that we understand the normal behavior of adult lung stem cells, and how this is regulated. Lung embryonic progenitor cells are much better defined and characterized than their adult counterparts. Moreover, experiments on a variety of developing tissues are beginning to uncover general mechanisms by which embryonic progenitors influence final organ size and structure. This provides a framework for the study of lung embryonic progenitor cells, facilitating experimental design and interpretation. A similar approach to investigating adult lung stem cells could produce rapid advances in the field. PMID:18684716

  12. Internet Fuel Cells Forum

    SciTech Connect

    Sudhoff, Frederick A.

    1996-08-01

    The rapid development and integration of the Internet into the mainstream of professional life provides the fuel cell industry with the opportunity to share new ideas with unprecedented capabilities. The U.S. Department of Energy's (DOE's) Morgantown Energy Technology Center (METC) has undertaken the task to maintain a Fuel Cell Forum on the Internet. Here, members can exchange ideas and information pertaining to fuel cell technologies. The purpose of this forum is to promote a better understanding of fuel cell concepts, terminology, processes, and issues relating to commercialization of fuel cell power technology. The Forum was developed by METC to provide those interested with fuel cell conference information for its current concept of exchanging ideas and information pertaining to fuel cells. Last August, the Forum expanded to an on-line and world-wide network. There are 250 members, and membership is growing at a rate of several new subscribers per week. The forum currently provides updated conference information and interactive information exchange. Forum membership is encouraged from utilities, industry, universities, and government. Because of the public nature of the internet, business sensitive, confidential, or proprietary information should not be placed on this system. The Forum is unmoderated; therefore, the views and opinions of authors expressed in the forum do not necessarily state or reflect those of the U.S. government or METC.

  13. Classification of cell death

    PubMed Central

    Kroemer, G; Galluzzi, L; Vandenabeele, P; Abrams, J; Alnemri, ES; Baehrecke, EH; Blagosklonny, MV; El-Deiry, WS; Golstein, P; Green, DR; Hengartner, M; Knight, RA; Kumar, S; Lipton, SA; Malorni, W; Nuñez, G; Peter, ME; Tschopp, J; Yuan, J; Piacentini, M; Zhivotovsky, B; Melino, G

    2009-01-01

    Different types of cell death are often defined by morphological criteria, without a clear reference to precise biochemical mechanisms. The Nomenclature Committee on Cell Death (NCCD) proposes unified criteria for the definition of cell death and of its different morphologies, while formulating several caveats against the misuse of words and concepts that slow down progress in the area of cell death research. Authors, reviewers and editors of scientific periodicals are invited to abandon expressions like ‘percentage apoptosis’ and to replace them with more accurate descriptions of the biochemical and cellular parameters that are actually measured. Moreover, at the present stage, it should be accepted that caspase-independent mechanisms can cooperate with (or substitute for) caspases in the execution of lethal signaling pathways and that ‘autophagic cell death’ is a type of cell death occurring together with (but not necessarily by) autophagic vacuolization. This study details the 2009 recommendations of the NCCD on the use of cell death-related terminology including ‘entosis’, ‘mitotic catastrophe’, ‘necrosis’, ‘necroptosis’ and ‘pyroptosis’. PMID:18846107

  14. The beta cell immunopeptidome.

    PubMed

    Dudek, Nadine L; Purcell, Anthony W

    2014-01-01

    Type 1 diabetes results from the autoimmune-mediated destruction of insulin-secreting beta cells, leading to beta cell loss and insulin deficiency. Presentation of peptides derived from beta cell proteins to autoreactive lymphocytes is critical for the development of disease, and the list of antigens recognized is increasing. A number of these proteins are found within the beta cell secretory granules, which are transiently exposed to the immune system during normal cellular function. How the interplay of environmental and genetic determinants culminates in destructive autoimmunity remains to be clearly defined. Nonconventional presentation of peptide ligands, posttranslational modification of peptides, and the role of the gut microbiome in the development of the immune system are all considered central topics in disease pathogenesis. Each of these may provide a mechanism by which presentation of antigenic peptides in the target tissue differs from presentation in the thymus, allowing autoreactive cells to escape tolerance induction. The high metabolic demand on pancreatic islets, the high concentration of granule proteins, and the susceptibility of islets to cellular stress may all contribute to the presentation of abnormal ligands in the pancreas. Moreover, the finding that small molecules can alter the repertoire of peptides presented by major histocompatibility complex molecules provides a tantalizing hypothesis for the presentation of autoantigenic peptides in the presence of microbial or endogenous metabolites. In this chapter, we provide an overview of the immunopeptidome of beta cells and the key factors that may influence presentation of beta cell antigens to the immune system.

  15. Stretching cells with DEAs

    NASA Astrophysics Data System (ADS)

    Akbari, S.; Rosset, S.; Shea, H. R.

    2012-04-01

    Biological cells regulate their biochemical behavior in response to mechanical stress present in their organism. Most of the available cell cultures designed to study the effect of mechanical stimuli on cells are cm2 area, far too large to monitor single cell response or have a very low throughput. We have developed two sets of high throughput single cell stretcher devices based on dielectric elastomer microactuators to stretch groups of individual cells with various strain levels in a single experiment. The first device consists of an array of 100 μm x 200 μm actuators on a non-stretched PDMS membrane bonded to a Pyrex chip, showing up to 4.7% strain at the electric field of 96 V/μm. The second device contains an array of 100 μm x 100 μm actuators on a 160% uniaxially prestretched PDMS membrane suspended over a frame. 37% strain is recorded at the nominal electric field of 114 V/μm. The performance of these devices as a cell stretcher is assessed by comparing their static and dynamic behavior.

  16. Mast cells and inflammation.

    PubMed

    Stassen, Michael; Hültner, Lothar; Müller, Christian; Schmitt, Edgar

    2002-01-01

    Mast cells have long been recognized as potent producers of a large panel of biologically highly active mediators such as biogenic amines, arachidonic acid metabolites, cytokines and chemokines, but most of their biological functions have been elusive and speculative. By taking advantage of mast cell-deficient mice, the role of mast cells in a variety of experimental settings can now be studied in detail and such approaches have dramatically altered and enlarged our knowledge about mast cell biology and function. Herein we will focus on the role of mast cells in inflammatory reactions of diverse origin, such as delayed type hypersensitivity, atopy, immune complex-mediated inflammation and innate immune responses. From the current standpoint, there is no doubt that the most outstanding and beneficial feature of mast cells is their recently discovered ability to induce a life-saving inflammatory response rapidly upon encountering microbes and microbial constituents. Nevertheless, the picture is also emerging that mast cells are deeply involved in the induction and maintenance of a variety of severe allergic and autoimmune diseases. However, a deeper understanding of their activation and immune-modulatory capacity might open a new window for the development of curative strategies.

  17. Ellipsoidal cell flow system

    DOEpatents

    Salzman, Gary C.; Mullaney, Paul F.

    1976-01-01

    The disclosure relates to a system incorporating an ellipsoidal flow chamber having light reflective walls for low level light detection in practicing cellular analysis. The system increases signal-to-noise ratio by a factor of ten over prior art systems. In operation, laser light passes through the primary focus of the ellipsoid. A controlled flow of cells simultaneously passes through this focus so that the laser light impinges on the cells and is modulated by the cells. The reflective walls of the ellipsoid reflect the cell-modulated light to the secondary focus of the ellipsoid. A tapered light guide at the secondary focus picks up a substantial portion of modulated reflective light and directs it onto a light detector to produce a signal. The signal is processed to obtain the intensity distribution of the modulated light and hence sought after characteristics of the cells. In addition, cells may be dyed so as to fluoresce in response to the laser light and their fluorescence may be processed as cell-modulated light above described. A light discriminating filter would be used to distinguish reflected modulated laser light from reflected fluorescent light.

  18. Llgl1 Connects Cell Polarity with Cell-Cell Adhesion in Embryonic Neural Stem Cells.

    PubMed

    Jossin, Yves; Lee, Minhui; Klezovitch, Olga; Kon, Elif; Cossard, Alexia; Lien, Wen-Hui; Fernandez, Tania E; Cooper, Jonathan A; Vasioukhin, Valera

    2017-06-05

    Malformations of the cerebral cortex (MCCs) are devastating developmental disorders. We report here that mice with embryonic neural stem-cell-specific deletion of Llgl1 (Nestin-Cre/Llgl1(fl/fl)), a mammalian ortholog of the Drosophila cell polarity gene lgl, exhibit MCCs resembling severe periventricular heterotopia (PH). Immunohistochemical analyses and live cortical imaging of PH formation revealed that disruption of apical junctional complexes (AJCs) was responsible for PH in Nestin-Cre/Llgl1(fl/fl) brains. While it is well known that cell polarity proteins govern the formation of AJCs, the exact mechanisms remain unclear. We show that LLGL1 directly binds to and promotes internalization of N-cadherin, and N-cadherin/LLGL1 interaction is inhibited by atypical protein kinase C-mediated phosphorylation of LLGL1, restricting the accumulation of AJCs to the basolateral-apical boundary. Disruption of the N-cadherin-LLGL1 interaction during cortical development in vivo is sufficient for PH. These findings reveal a mechanism responsible for the physical and functional connection between cell polarity and cell-cell adhesion machineries in mammalian cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Basic cell culture.

    PubMed

    Pollard, J W

    1990-01-01

    This article will describe the basic techniques required for successful cell culture. It will also act to introduce some of the other chapters in this volume. It is not intended, as this volume is not, to describe the establishment of a tissue culture laboratory, nor to provide a historical or theoretical survey of cell culture. There are several books that adequately cover these areas, including the now somewhat dated but still valuable volume by Paul (1), the multi-authored Methods in Enzymology volume edited by Jakoby and Pastan (2), and the new edition of Freshney (3). Instead, this chapter's focus will be on the techniques for establishing primary rodent cell cultures from embryos and adult skin, maintaining and subculturing these fibro-blasts and their transformed derivatives, and the isolation of genetically pure strains. The cells described are all derived from Chinese hamsters since, to date, these cells, have proved to be the most useful for somatic cell genetics (4,5). The techniques, however, are generally applicable to most fibroblastic cell types.

  20. Cell line provenance.

    PubMed

    Freshney, R Ian

    2002-07-01

    Cultured cell lines have become an extremely valuable resource, both in academic research and in industrial biotechnology. However, their value is frequently compromised by misidentification and undetected microbial contamination. As detailed elsewhere in this volume, the technology, both simple and sophisticated, is available to remedy the problems of misidentification and contamination, given the will to apply it. Combined with proper records of the origin and history of the cell line, assays for authentication and contamination contribute to the provenance of the cell line. Detailed records should start from the initiation or receipt of the cell line, and should incorporate data on the donor as well as the tissue from which the cell line was derived, should continue with details of maintenance, and include any accidental as well as deliberate deviations from normal maintenance. Records should also contain details of authentication and regular checks for contamination. With this information, preferably stored in a database, and suitable backed up, the provenance of the cell line so created makes the cell line a much more valuable resource, fit for validation in industrial applications and more likely to provide reproducible experimental results when disseminated for research in other laboratories.

  1. Rethinking Guard Cell Metabolism.

    PubMed

    Santelia, Diana; Lawson, Tracy

    2016-11-01

    Stomata control gaseous fluxes between the internal leaf air spaces and the external atmosphere and, therefore, play a pivotal role in regulating CO2 uptake for photosynthesis as well as water loss through transpiration. Guard cells, which flank the stomata, undergo adjustments in volume, resulting in changes in pore aperture. Stomatal opening is mediated by the complex regulation of ion transport and solute biosynthesis. Ion transport is exceptionally well understood, whereas our knowledge of guard cell metabolism remains limited, despite several decades of research. In this review, we evaluate the current literature on metabolism in guard cells, particularly the roles of starch, sucrose, and malate. We explore the possible origins of sucrose, including guard cell photosynthesis, and discuss new evidence that points to multiple processes and plasticity in guard cell metabolism that enable these cells to function effectively to maintain optimal stomatal aperture. We also discuss the new tools, techniques, and approaches available for further exploring and potentially manipulating guard cell metabolism to improve plant water use and productivity. © 2016 American Society of Plant Biologists. All Rights Reserved.

  2. Mast cells and mastocytosis

    PubMed Central

    2008-01-01

    Mast cells have been recognized for well over 100 years. With time, human mast cells have been documented to originate from CD34+ cells, and have been implicated in host responses in both innate and acquired immunity. In clinical immunology, they are recognized for their central role in IgE-mediated degranulation and allergic inflammation by virtue of their expression of the high-affinity receptor for IgE and release of potent proinflammatory mediators. In hematology, the clinical disease of mastocytosis is characterized by a pathologic increase of mast cells in tissues, often associated with mutations in KIT, the receptor for stem cell factor. More recently, and with increased understanding of how human mast cells are activated through receptors including the high-affinity receptor for IgE and KIT, specific tyrosine kinase inhibitors have been identified with the potential to interrupt signaling pathways and thus limit the proliferation of mast cells as well as their activation through immunoglobulin receptors. PMID:18684881

  3. Modulating cell-cell communication with a high-throughput label-free cell assay.

    PubMed

    Li, Guangshan; Lai, Fang; Fang, Ye

    2012-02-01

    A high-throughput label-free cell assay for modulating cell-cell communication is demonstrated with the Epic® system, a resonant waveguide grating sensor platform. Natural killer (NK) cells are known to be able to recognize abnormal cells (e.g., cancer cells and cells presenting intercellular adhesion molecule 1 [ICAM1] through cell surface receptors) and kill them. In this study, the effect of effecter cells NK92MI on two kinds of target cells, cervical cancer cells (HeLa) and Chinese hamster ovarian cells overexpressing ICAM1 (CHO-ICAM1), was examined. Living target cells' response to NK92MI cells was monitored in real time and measured as wavelength shift in picometers. The authors showed that the detectability of target cell response is affected by multiple factors: the ratio of effecter cells to target cells (E/T), the interaction time of the two types of cells, and the target cell type. For example, with the effecter cells NK92MI and the same incubation time of 16 h, a minimal E/T ratio of 1 is required to detect HeLa cell response, whereas an E/T of 0.5 is sufficient to detect CHO-ICAM1 cell response. The authors confirmed that NK92MI cell-mediated target cell cytotoxicity results in negative optical signals and is associated with apoptosis mainly through caspase pathways. Distinct optical signals could be generated with the pretreatment of the target cells with various known pharmaceutical reagents, making the assay useful for discovering new chemicals that may affect cell-cell communications.

  4. Cell of Origin and Cancer Stem Cell Phenotype in Medulloblastomas

    DTIC Science & Technology

    2015-07-01

    AWARD NUMBER: W81XWH-14-1-0115 TITLE: Cell of Origin and Cancer Stem Cell Phenotype in Medulloblastomas PRINCIPAL INVESTIGATOR: Kyuson Yun...SUBTITLE Cell of Origin and Cancer Stem Cell Phenotype in Medulloblastomas 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1-0115 5c. PROGRAM...hypothesis, we proposed to transform neural stem cells (NSCs) and neural progenitor cells (NPCs) in vivo by expressing an activated form of Notch1 (N1ICD

  5. Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells

    DTIC Science & Technology

    2016-10-01

    AWARD NUMBER: W81XWH-15-1-0644 TITLE: Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells PRINCIPAL INVESTIGATOR: Chun-Ju...Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0644 5c. PROGRAM ELEMENT...Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Cancer stem cells (CSCs), a cell population with acquired perpetuating self-renewal properties

  6. T cell activation.

    PubMed

    Smith-Garvin, Jennifer E; Koretzky, Gary A; Jordan, Martha S

    2009-01-01

    This year marks the 25th anniversary of the first Annual Review of Immunology article to describe features of the T cell antigen receptor (TCR). In celebration of this anniversary, we begin with a brief introduction outlining the chronology of the earliest studies that established the basic paradigm for how the engaged TCR transduces its signals. This review continues with a description of the current state of our understanding of TCR signaling, as well as a summary of recent findings examining other key aspects of T cell activation, including cross talk between the TCR and integrins, the role of costimulatory molecules, and how signals may negatively regulate T cell function.Acronyms and DefinitionsAdapter protein: cellular protein that functions to bridge molecular interactions via characteristic domains able to mediate protein/protein or protein/lipid interactions Costimulation: signals delivered to T cells by cell surface receptors other than the TCR itself that potentiate T cell activation cSMAC: central supramolecular activation cluster Immunoreceptor tyrosine-based activation motif (ITAM): a short peptide sequence in the cytoplasmic tails of key surface receptors on hematopoietic cells that is characterized by tyrosine residues that are phosphorylated by Src family PTKs, enabling the ITAM to recruit activated Syk family kinases Inside-out signaling: signals initiated by engagement of immunoreceptors that lead to conformational changes and clustering of integrins, thereby increasing the affinity and avidity of the integrins for their ligands NFAT: nuclear factor of activated T cells PI3K: phosphoinositide 3-kinase PKC: protein kinase C PLC: phospholipase C pMHC: peptide major histocompatibility complex (MHC) complex pSMAC: peripheral supramolecular activation cluster PTK: protein tyrosine kinase Signal transduction: biochemical events linking surface receptor engagement to cellular responses TCR: T cell antigen receptor

  7. Dye Sensitized Solar Cells

    PubMed Central

    Wei, Di

    2010-01-01

    Dye sensitized solar cell (DSSC) is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed. PMID:20480003

  8. Systems cell biology.

    PubMed

    Mast, Fred D; Ratushny, Alexander V; Aitchison, John D

    2014-09-15

    Systems cell biology melds high-throughput experimentation with quantitative analysis and modeling to understand many critical processes that contribute to cellular organization and dynamics. Recently, there have been several advances in technology and in the application of modeling approaches that enable the exploration of the dynamic properties of cells. Merging technology and computation offers an opportunity to objectively address unsolved cellular mechanisms, and has revealed emergent properties and helped to gain a more comprehensive and fundamental understanding of cell biology. © 2014 Mast et al.

  9. Estimating cell populations

    NASA Technical Reports Server (NTRS)

    White, B. S.; Castleman, K. R.

    1981-01-01

    An important step in the diagnosis of a cervical cytology specimen is estimating the proportions of the various cell types present. This is usually done with a cell classifier, the error rates of which can be expressed as a confusion matrix. We show how to use the confusion matrix to obtain an unbiased estimate of the desired proportions. We show that the mean square error of this estimate depends on a 'befuddlement matrix' derived from the confusion matrix, and how this, in turn, leads to a figure of merit for cell classifiers. Finally, we work out the two-class problem in detail and present examples to illustrate the theory.

  10. Mechanochemical cell biology.

    PubMed

    Cross, R A; McAinsh, A D; Straube, A

    2011-12-01

    Eukaryotic systems self-organise by using molecular railways to shuttle specific sets of molecular components to specific locations. In this way, cells are enabled to become larger, more complex and more varied, subtle and effective in their activities. Because of the fundamental importance of molecular railways in eukaryotic systems, understanding how these railways work is an important research goal. Mechanochemical cell biology is a newly circumscribed subject area that concerns itself with the molecular and cell biological mechanisms of motorised directional transport in living systems. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Cells in Space

    NASA Technical Reports Server (NTRS)

    Sibonga, Jean D. (Editor); Mains, Richard C. (Editor); Fast, Thomas N. (Editor); Callahan, Paul X. (Editor); Winget, Charles M. (Editor)

    1989-01-01

    Discussions and presentations addressed three aspects of cell research in space: the suitability of the cell as a subject in microgravity experiments, the requirements for generic flight hardware to support cell research, and the potential for collaboration between academia, industry, and government to develop these studies in space. Synopses are given for the presentations and follow-on discussions at the conference and papers are presented from which the presentations were based. An Executive Summary outlines the recommendations and conclusions generated at the conference.

  12. Cell Growth Enhancement

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Exogene Corporation uses advanced technologies to enhance production of bio-processed substances like proteins, antibiotics and amino acids. Among them are genetic modification and a genetic switch. They originated in research for Jet Propulsion Laboratory. Extensive experiments in cell growth through production of hemoglobin to improve oxygen supply to cells were performed. By improving efficiency of oxygen use by cells, major operational expenses can be reduced. Greater product yields result in decreased raw material costs and more efficient use of equipment. A broad range of applications is cited.

  13. Cell adhesion under flow.

    PubMed

    Ley, Klaus

    2009-01-01

    Cell adhesion under flow is a central function of the microcirculation during inflammation, hemostasis, and immune regulation. This special issue of Microcirculation explores the common and distinct mechanisms that myeloid cells, lymphocytes, platelets, and sickle erythrocytes use to adhere to microvascular endothelium and the underlying basement membrane structures. A common theme in these processes is the need for rapid integrin activation, often initiated by binding of ligands to their cognate G protein-coupled receptors, followed by adhesion strengthening associated with integrin redistribution and outside-in signaling. These elements have been identified for all cells tested except sickle erythrocytes.

  14. Estimating cell populations

    NASA Technical Reports Server (NTRS)

    White, B. S.; Castleman, K. R.

    1981-01-01

    An important step in the diagnosis of a cervical cytology specimen is estimating the proportions of the various cell types present. This is usually done with a cell classifier, the error rates of which can be expressed as a confusion matrix. We show how to use the confusion matrix to obtain an unbiased estimate of the desired proportions. We show that the mean square error of this estimate depends on a 'befuddlement matrix' derived from the confusion matrix, and how this, in turn, leads to a figure of merit for cell classifiers. Finally, we work out the two-class problem in detail and present examples to illustrate the theory.

  15. Bipolar fuel cell

    DOEpatents

    McElroy, James F.

    1989-01-01

    The present invention discloses an improved fuel cell utilizing an ion transporting membrane having a catalytic anode and a catalytic cathode bonded to opposite sides of the membrane, a wet-proofed carbon sheet in contact with the cathode surface opposite that bonded to the membrane and a bipolar separator positioned in electrical contact with the carbon sheet and the anode of the adjacent fuel cell. Said bipolar separator and carbon sheet forming an oxidant flowpath, wherein the improvement comprises an electrically conductive screen between and in contact with the wet-proofed carbon sheet and the bipolar separator improving the product water removal system of the fuel cell.

  16. Double heterojunction solar cells

    SciTech Connect

    Cacheux, J.A.

    1980-03-04

    A photovoltaic cell is disclosed comprising two heterojunctions between three component semiconductors Ga/sub 1-x/ Al/sub x/ as with X varying from 0 to 9, GaAs, and Ge which have respective bandgaps of 0.66, 1. And 2.4 ev, lattice constants matching at 0.07% and expansion coefficients matching at 1.7%. The cell is mounted in a cell device comprising a parallelepipedal unit, a fresnel lens, a tapering cavity within said unit, partially filled up with a lens shaped antireflecting transparent material and a radiator, said device forming a sunlight concentrator.

  17. PLUTONIUM ELECTROREFINING CELLS

    DOEpatents

    Mullins, L.J. Jr.; Leary, J.A.; Bjorklund, C.W.; Maraman, W.J.

    1963-07-16

    Electrorefining cells for obtaining 99.98% plutonium are described. The cells consist of an impure liquid plutonium anode, a molten PuCl/sub 3/-- alkali or alkaline earth metal chloanode, a molten PuCl/sub 3/-alkali or alkaline earth metal chloride electrolyte, and a nonreactive cathode, all being contained in nonreactive ceramic containers which separate anode from cathode by a short distance and define a gap for the collection of the purified liquid plutonium deposited on the cathode. Important features of these cells are the addition of stirrer blades on the anode lead and a large cathode surface to insure a low current density. (AEC)

  18. Cells on chips

    NASA Astrophysics Data System (ADS)

    El-Ali, Jamil; Sorger, Peter K.; Jensen, Klavs F.

    2006-07-01

    Microsystems create new opportunities for the spatial and temporal control of cell growth and stimuli by combining surfaces that mimic complex biochemistries and geometries of the extracellular matrix with microfluidic channels that regulate transport of fluids and soluble factors. Further integration with bioanalytic microsystems results in multifunctional platforms for basic biological insights into cells and tissues, as well as for cell-based sensors with biochemical, biomedical and environmental functions. Highly integrated microdevices show great promise for basic biomedical and pharmaceutical research, and robust and portable point-of-care devices could be used in clinical settings, in both the developed and the developing world.

  19. Energy: Reimagine Fuel Cells

    SciTech Connect

    Lemmon, John P.

    2015-09-24

    New types of fuel cell on the horizon could eliminate the need for such trade-offs and ease the integration of renewables into the grid. Currently, fuel cells are used to generate only electricity and heat. They can be modified to store energy and produce liquid fuels such as methanol, thanks to breakthroughs in materials and designs. Developing fuel cells with a battery mode is one focus of the programme I direct at the US Advanced Research Projects Agency–Energy (ARPA-E). I lead 13 projects across academia, industry and national laboratories.

  20. Dye sensitized solar cells.

    PubMed

    Wei, Di

    2010-03-16

    Dye sensitized solar cell (DSSC) is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO(2), ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed.

  1. Plasticity of osteoprogenitor cells.

    PubMed

    Lafage-Proust, Marie Hélène; Thomas, Thierry; Guignandon, Alain; Malaval, Luc; Rattner, Aline; Vico, Laurence

    2007-12-01

    Plasticity is the ability to give rise to cell types whose phenotype is different from that of the source tissue. Osteoblasts originate in progenitors located in the bone marrow or around blood vessels. Marrow stromal cells can differentiate into adipocytes, in part at the expense of osteoblasts. The osteoblast-adipocyte balance is influenced by systemic factors, chiefly hormones, and local factors in the microenvironment, as well as by mechanical loads, which induce or suppress the activity of transcription factors crucial to the differentiation of each cell type. New insights into the molecular mechanisms involved in controlling the osteoblast-adipocyte balance are unlocking doors to a vast array of innovative treatment strategies.

  2. Quantum well solar cells

    NASA Astrophysics Data System (ADS)

    Barnham, K. W. J.; Ballard, I.; Connolly, J. P.; Ekins-Daukes, N. J.; Kluftinger, B. G.; Nelson, J.; Rohr, C.

    2002-04-01

    This paper reviews the experimental and theoretical studies of quantum well solar cells with an aim of providing the background to the more detailed papers on this subject in these proceedings. It discusses the way quantum wells enhance efficiency in real, lattice matched material systems and fundamental studies of radiative recombination relevant to the question of whether such enhancements are possible in ideal cells. A number of theoretical models for quantum well solar cells (QWSCs) are briefly reviewed and more detail is given of our own group's model of the dark-currents. The temperature and field dependence of QWSCs are all briefly reviewed.

  3. Cadmium sulphide solar cell

    SciTech Connect

    Bassett, P.J.; Verheijen, A.W.

    1984-07-31

    The invention relates to the manufacture of cadmium sulphide solar cells. A cell is formed of a glass substrate 10, a front contact 12 made, for example, of tin oxide, a cadmium sulphide layer 14 and a copper sulphide layer 16, the junction between the layers 14 and 16 is photovoltaic. In order to form a rear contact 18 on the copper sulphide layer, the invention proposes vapor depositing a mixed layer of copper and copper oxide onto the sulphide layer. The invention also describes a method of heat treatment following the formation of the rear contact in order to optimise the electrical performance of the cell.

  4. White cell design considerations

    NASA Technical Reports Server (NTRS)

    Hannan, Paul

    1989-01-01

    The White cell is a unit-magnification image relay system consisting of three noncoaxial spherical mirrors of equal curvature. The cell is used to provide a long optical path in a relatively small physical space. Multiple reflections are used, in a manner similar to a unstable laser resonator. A particular application is an optical delay line on the input of a streak camera to allow for the finite triggering time of the sweep start. This paper addresses the first- and third-order properties of the White cell. A displacement sensitivity analysis is included.

  5. [Retroperitoneal germ cell tumor].

    PubMed

    Borrell Palanca, A; García Garzón, J; Villamón Fort, R; Domenech Pérez, C; Martínez Lorente, A; Gunthner, S; García Sisamón, F

    1999-03-01

    We report a case of retroperitoneal extragonadal germ-cell tumor in an 17 years old patient who presented with aedema and pain in left inferior extremity asociated with hemopthysis caused by pulmonar metastasis, who was treated with chemotherapy and resection of residual mass and pulmonary nodes. Dyagnosis was stableshed by fine neadle aspiration biopsy of the wass. We comment on the difficult of stableshing differential dyagnosis between retroperitoneal extragonadal germ-cell tumor and metastasis of a testicular tumor. Dyagnosis is stableshed by the finding of a histologically malignant germ-cell tumor with normal testis. We considered physical examination and ecographyc exploration enough for a correct dyagnosis.

  6. CLO: The cell line ontology

    PubMed Central

    2014-01-01

    Background Cell lines have been widely used in biomedical research. The community-based Cell Line Ontology (CLO) is a member of the OBO Foundry library that covers the domain of cell lines. Since its publication two years ago, significant updates have been made, including new groups joining the CLO consortium, new cell line cells, upper level alignment with the Cell Ontology (CL) and the Ontology for Biomedical Investigation, and logical extensions. Construction and content Collaboration among the CLO, CL, and OBI has established consensus definitions of cell line-specific terms such as ‘cell line’, ‘cell line cell’, ‘cell line culturing’, and ‘mortal’ vs. ‘immortal cell line cell’. A cell line is a genetically stable cultured cell population that contains individual cell line cells. The hierarchical structure of the CLO is built based on the hierarchy of the in vivo cell types defined in CL and tissue types (from which cell line cells are derived) defined in the UBERON cross-species anatomy ontology. The new hierarchical structure makes it easier to browse, query, and perform automated classification. We have recently added classes representing more than 2,000 cell line cells from the RIKEN BRC Cell Bank to CLO. Overall, the CLO now contains ~38,000 classes of specific cell line cells derived from over 200 in vivo cell types from various organisms. Utility and discussion The CLO has been applied to different biomedical research studies. Example case studies include annotation and analysis of EBI ArrayExpress data, bioassays, and host-vaccine/pathogen interaction. CLO’s utility goes beyond a catalogue of cell line types. The alignment of the CLO with related ontologies combined with the use of ontological reasoners will support sophisticated inferencing to advance translational informatics development. PMID:25852852

  7. Conversion of primordial germ cells to pluripotent stem cells: methods for cell tracking and culture conditions.

    PubMed

    Nagamatsu, Go; Suda, Toshio

    2013-01-01

    Primordial germ cells (PGCs) are unipotent cells committed to germ lineage: PGCs can only differentiate into gametes in vivo. However, upon fertilization, germ cells acquire the capacity to differentiate into all cell types in the body, including germ cells. Therefore, germ cells are thought to have the potential for pluripotency. PGCs can convert to pluripotent stem cells in vitro when cultured under specific conditions that include bFGF, LIF, and the membrane-bound form of SCF (mSCF). Here, the culture conditions which efficiently convert PGCs to pluripotent embryonic germ (EG) cells are described, as well as methods used for identifying pluripotent candidate cells during culture.

  8. HDAC2 regulates cell proliferation, cell cycle progression and cell apoptosis in esophageal squamous cell carcinoma EC9706 cells

    PubMed Central

    Li, Shenglei; Wang, Feng; Qu, Yunhui; Chen, Xiaoqi; Gao, Ming; Yang, Jianping; Zhang, Dandan; Zhang, Na; Li, Wencai; Liu, Hongtao

    2017-01-01

    Increasing evidence has demonstrated that histone deacetylase 2 (HDAC2) participates in the regulation of a variety of biological processes in numerous tumors. However, the potential role of HDAC2 in the development and progression of esophageal squamous cell carcinoma (ESCC) remains elusive. Immunohistochemistry was utilized to detect the expression of HDAC2, Cell Counting Kit-8 was used to determine the cell proliferation, and flow cytometry was employed to investigate cell cycle and cell apoptosis. Finally, western blotting was employed to detect the protein expression of cyclin D1, p21, B cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax). The present study found that expression of HDAC2 protein in ESCC tissues was significantly increased compared with atypical hyperplasia tissues and normal esophageal mucosa (P<0.001). The expression of HDAC2 was not associated with the age or gender of patients (P>0.05), but was closely associated with the histological grade, invasion depth, tumor-node-metastasis stage and lymph node metastasis, respectively (all P<0.001). HDAC2 small interfering RNA effectively downregulated the expression of HDAC2 protein in ESCC EC9706 cells. Downregulation of HDAC2 expression evidently inhibited cell proliferation, arrested cell cycle at the G0/G1 phase and induced cell apoptosis in ESCC EC9706 cells, coupled with increased expression of p21 and Bax proteins and decreased expression of cyclin D1 and Bcl-2 proteins. Overall, the present findings suggest that HDAC2 may play an important role in the development and progression of ESCC and be considered as a novel molecular target for the treatment of ESCC. PMID:28123574

  9. Physical mechanisms redirecting cell polarity and cell shape

    PubMed Central

    Terenna, Courtney R.; Makushok, Tatyana; Velve-Casquillas, Guilhem; Baigl, Damien; Chen, Yong; Bornens, Michel; Paoletti, Anne; Piel, Matthieu; Tran, Phong T.

    2010-01-01

    Summary The fission yeast Schizosaccharomyces pombe has a cylindrical rod-shape that is organized and maintained by interactions between the microtubule, cell membrane, and actin cytoskeleton; i.e., microtubules deliver factors to the cell tips that subsequently recruit the actin machinery to direct localized cell growth [1]. Mutations affecting any components in this pathway lead to bent, branched, or round cells [2]. In this context, the cytoskeleton controls cell polarity and thus dictates cell shape. Here, we use soft-lithography techniques to construct microfluidic channels in order to control the shape of cells. We show that by physically forcing wildtype rod-shaped cells to grow bent, they will re-organize their cytoskeleton and re-direct cell polarity to make new ectopic cell tips. In addition, by physically forcing bent or round mutant cells to conform to the wildtype rod-shape, cells will reverse their mutational phenotypes by re-organizing their cytoskeleton to maintain proper wildtype-like microtubule, cell membrane proteins, and actin localizations. Our study provides direct evidence that the cytoskeleton controls cell polarity and cell shape and demonstrates that cell shape also controls the organization of the cytoskeleton, in a feedback loop. We present a model of the feedback loop which explains how fission yeast cells maintain a rod-shape, and how perturbation of specific parameters of the loop can lead to different cell shapes. PMID:19026544

  10. Stem cell biology and cell transplantation therapy in the retina.

    PubMed

    Osakada, Fumitaka; Hirami, Yasuhiko; Takahashi, Masayo

    2010-01-01

    Embryonic stem (ES) cells, which are derived from the inner cell mass of mammalian blastocyst stage embryos, have the ability to differentiate into any cell type in the body and to grow indefinitely while maintaining pluripotency. During development, cells undergo progressive and irreversible differentiation into specialized adult cell types. Remarkably, in spite of this restriction in potential, adult somatic cells can be reprogrammed and returned to the naive state of pluripotency found in the early embryo simply by forcing expression of a defined set of transcription factors. These induced pluripotent stem (iPS) cells are molecularly and functionally equivalent to ES cells and provide powerful in vitro models for development, disease, and drug screening, as well as material for cell replacement therapy. Since functional impairment results from cell loss in most central nervous system (CNS) diseases, recovery of lost cells is an important treatment strategy. Although adult neurogenesis occurs in restricted regions, the CNS has poor potential for regeneration to compensate for cell loss. Thus, cell transplantation into damaged or diseased CNS tissues is a promising approach to treating various neurodegenerative disorders. Transplantation of photoreceptors or retinal pigment epithelium cells derived from human ES cells can restore some visual function. Patient-specific iPS cells may lead to customized cell therapy. However, regeneration of retinal function will require a detailed understanding of eye development, visual system circuitry, and retinal degeneration pathology. Here, we review the current progress in retinal regeneration, focusing on the therapeutic potential of pluripotent stem cells.

  11. Cell Shape and Cell Division in Fission Yeast Minireview

    PubMed Central

    Piel, Matthieu; Tran, Phong T.

    2010-01-01

    The fission yeast Schizosaccharomyces pombe has served as an important model organism for investigating cellular morphogenesis. This unicellular rod-shaped fission yeast grows by tip extension and divides by medial fission. In particular, microtubules appear to define sites of polarized cell growth by delivering cell polarity factors to the cell tips. Microtubules also position the cell nucleus at the cell middle, marking sites of cell division. Here, we review the microtubule-dependent mechanisms that regulate cell shape and cell division in fission yeast. PMID:19906584

  12. Cell therapy for diabetes mellitus: an opportunity for stem cells?

    PubMed

    Soria, B; Bedoya, F J; Tejedo, J R; Hmadcha, A; Ruiz-Salmerón, R; Lim, S; Martin, F

    2008-01-01

    Diabetes is a chronic disease characterized by a deficit in beta cell mass and a failure of glucose homeostasis. Both circumstances result in a variety of severe complications and an overall shortened life expectancy. Thus, diabetes represents an attractive candidate for cell therapy. Reversal of diabetes can be achieved through pancreas and islet transplantation, but shortage of donor organs has prompted an intensive search for alternative sources of beta cells. This achievement has stimulated the search for appropriate stem cell sources. Both embryonic and adult stem cells have been used to generate surrogate beta cells or otherwise restore beta cell functioning. In this regard, several studies have reported the generation of insulin-secreting cells from embryonic and adult stem cells that normalized blood glucose values when transplanted into diabetic animal models. Due to beta cell complexity, insulin-producing cells generated from stem cells do not possess all beta cell attributes. This indicates the need for further development of methods for differentiation and selection of completely functional beta cells. While these problems are overcome, diabetic patients may benefit from therapeutic strategies based on autologous stem cell therapies addressing late diabetic complications. In this article, we discuss the recent progress in the generation of insulin-producing cells from embryonic and adult stem cells, together with the challenges for the clinical use of diabetes stem cell therapy.

  13. Stem cells and transplant arteriosclerosis.

    PubMed

    Xu, Qingbo

    2008-05-09

    Stem cells can differentiate into a variety of cells to replace dead cells or to repair damaged tissues. Recent evidence indicates that stem cells are involved in the pathogenesis of transplant arteriosclerosis, an alloimmune initiated vascular stenosis that often results in transplant organ failure. Although the pathogenesis of transplant arteriosclerosis is not yet fully understood, recent developments in stem cell research have suggested novel mechanisms of vascular remodeling in allografts. For example, stem cells derived from the recipient may repair damaged endothelial cells of arteries in transplant organs. Further evidence suggests that stem cells or endothelial progenitor cells may be released from both bone marrow and non-bone marrow tissues. Vascular stem cells appear to replenish cells that died in donor vessels. Concomitantly, stem/progenitor cells may also accumulate in the intima, where they differentiate into smooth muscle cells. However, several issues concerning the contribution of stem cells to the pathogenesis of transplant arteriosclerosis are controversial, eg, whether bone marrow-derived stem cells can differentiate into smooth muscle cells that form neointimal lesions of the vessel wall. This review summarizes recent research on the role of stem cells in transplant arteriosclerosis, discusses the mechanisms of stem cell homing and differentiation into mature endothelial and smooth muscle cells, and highlights the controversial issues in the field.

  14. Multipotent Stem Cell and Reproduction.

    PubMed

    Khanlarkhani, Neda; Baazm, Maryam; Mohammadzadeh, Farzaneh; Najafi, Atefeh; Mehdinejadiani, Shayesteh; Sobhani, Aligholi

    2016-01-01

    Stem cells are self-renewing and undifferentiated cell types that can be differentiate into functional cells. Stem cells can be classified into two main types based on their source of origin: Embryonic and Adult stem cells. Stem cells also classified based on the range of differentiation potentials into Totipotent, Pluripotent, Multipotent, and Unipotent. Multipotent stem cells have the ability to differentiate into all cell types within one particular lineage. There are plentiful advantages and usages for multipotent stem cells. Multipotent Stem cells act as a significant key in procedure of development, tissue repair, and protection. The accessibility and adaptability of these amazing cells create them a great therapeutic choice for different part of medical approaches, and it becomes interesting topic in the scientific researches to found obvious method for the most advantageous use of MSC-based therapies. Recent studies in the field of stem cell biology have provided new perspectives and opportunities for the treatment of infertility disorders.

  15. Immunobiology of natural killer cells

    SciTech Connect

    Lotzova, E.; Herberman, R.B.

    1986-01-01

    This book combines research from many disciplines into a review of natural killer (NK) cell-mediated immunity in humans and experimental animal system. Topics for the volumes include: Volume I: Assays for NK Cell Cytotoxicity; Their Values and Pitfalls. Separation and Characterization of Phenotypically Distinct Subsets of NK Cells. Ultrastructure and Cytochemistry of the Human Large Granular Lymphocytes. Phylogeny and Ontogeny of NK Cells. Tissue and Organ distribution of NK Cells. Genetic Control of NK Cell Activity in Rodents. Phenotype, Functional Heterogeneity, and Lineage of Natural Killer Cells. Target Cell Structures, Recognition Sites, and the Mechanism of NK Cytotoxicity. Natural Killer Cytotoxic Factors (NKCF) Role in Cell-Mediated Cytotoxicity. Characteristics of Cultured NK Cells. Lectin-Dependent Killer Cells. MLC-Induced Cytotoxicity as a Model for the Development and Regulation of NK Cytotoxicity. LGL Lymphoproliferative Diseases in Man and Experimental Animals: The Characteristics of These Cells and Their Potential Experimental Uses. Index.

  16. NK Cells and Cancer Immunoediting.

    PubMed

    Guillerey, Camille; Smyth, Mark J

    2016-01-01

    Natural killer (NK) cells are innate lymphoid cells (ILC) known for their ability to recognize and rapidly eliminate infected or transformed cells. Consequently, NK cells are fundamental for host protection against virus infections and malignancies. Even though the critical role of NK cells in cancer immunosurveillance was suspected years ago, the underlying mechanisms took time to be unraveled. Today, it is clear that anti-tumor functions of NK cells are tightly regulated and expand far beyond the simple killing of malignant cells. In spite of tremendous steps made in understanding the NK cell biology, further work is warranted to fully exploit the anticancer potential of these cells. Indeed, tumor-mediated immune suppression hampers NK cell activity, thus complicating their stimulation for therapeutic purposes. Herein, we review the current knowledge of NK cell functions in anti-tumor immunity . We discuss NK cell activity in the cancer immunoediting process with particular emphasis on the elimination and escape phases.

  17. Altered glycosylation in tumor cells

    SciTech Connect

    Reading, C.L. ); Hakomori, S. ); Marcus, D.M. )

    1988-01-01

    This book contains the proceeding on the following: Glycoconjugates of normal and tumor cells; Glycosyltransferases in normal and neoplastic cells; Mammalian lectins of normal tissues and tumor cells; and Immune recognition of carbohydrates and clinical applications.

  18. Stem Cell Transplants (For Teens)

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Stem Cell Transplants KidsHealth > For Teens > Stem Cell Transplants Print ... Does it Take to Recover? Coping What Are Stem Cells? As you probably remember from biology class, every ...

  19. Information on Stem Cell Research

    MedlinePlus

    ... Home » Current Research » Focus on Research Focus on Stem Cell Research Stem cells possess the unique ability to differentiate ... virus infection. To search the complete list of stem cell research projects funded by NIH please go to NIH ...

  20. Fuel cell system with interconnect

    DOEpatents

    Liu, Zhien; Goettler, Richard

    2016-12-20

    The present invention includes an integrated planar, series connected fuel cell system having electrochemical cells electrically connected via interconnects, wherein the anodes of the electrochemical cells are protected against Ni loss and migration via an engineered porous anode barrier layer.