Slow and Prolonged Activation of the p47 Protein Kinase during Hypersensitive Cell Death in a Culture of Tobacco Cells

To investigate the involvement of protein kinases in the signaling cascade that leads to hypersensitive cell death, we used a previously established system in which a fungal elicitor, xylanase from Trichoderma viride (TvX), induces a hypersensitive reaction in tobacco (Nicotiana tabacum) cells in culture (line XD6S). The elicitor induced the slow and prolonged activation of a p47 protein kinase, which has the characteristics of a family member of the mitogen-activated protein kinases. An inhibitor of protein kinases, staurosporine, and a blocker of Ca channels, Gd3+ ions, both of which blocked the TvX-induced hypersensitive cell death, inhibited the TvX-induced activation of p47 protein kinase. Moreover, an inhibitor of serine/threonine protein phosphatase alone induced both rapid cell death and the persistent activation of the p47 protein kinase. Thus, the p47 protein kinase might be a component of the signal transduction pathway that leads to hypersensitive cell death, and the regulation of the duration of activation of the p47 protein kinase might be important in determining the destiny of tobacco cells.

Long-term culture of lymphohematopoietic stem cells.

Pluripotent hematopoietic stem cells (PHSCs) show self-renewal and give rise to all blood cell types. The extremely low number of these cells in primary hematopoietic organs and the lack of culture systems that support proliferation of undifferentiated PHSCs have precluded the study of both the biology of these cells and their clinical application. We describe here cell lines and clones derived from PHSCs that were established from hematopoietic cells from the fetal liver or bone marrow of normal and p53-deficient mice with a combination of four growth factors. Most cell lines were Sca-1+, c-Kit+, PgP-1+, HSA+, and Lin- (B-220-, Joro 75-, 8C5-, F4/80-, CD4-, CD8-, CD3-, IgM-, and TER 119-negative) and expressed three new surface markers: Joro 177, Joro 184, and Joro 96. They did not synthesize RNA transcripts for several genes expressed at early stages of lymphocyte and myeloid/erythroid cell development. The clones were able to generate lymphoid, myeloid, and erythroid hematopoietic cells and to reconstitute the hematopoietic system of irradiated mice for a long time. The availability of lymphohematopoietic stem cell lines should facilitate the analysis of the molecular mechanisms that control self-renewal and differentiation and the development of efficient protocols for somatic gene therapy.

Time course modifications in organotypic culture of human neuroretina

The purpose of this study was to characterize organ culture of human neuroretina and to establish survival and early degeneration patterns of neural and glial cells. Sixteen neuroretina explants were prepared from 2 postmortem eyes of 2 individuals. Four explants were used as fresh retina controls, and 12 were evaluated at 3, 6, and 9 days of culture. Neuroretina explants (5 × 5 mm) were cultured in Transwell® dishes with the photoreceptor layer facing the supporting membrane. Culture medium (Neurobasal A-based) was maintained in contact with the membrane beneath the explant. Cryostat and ultrathin sections were prepared for immunohistochemistry and electron microscopy. Neuroretinal modifications were evaluated after toluidine blue staining and after immunostaining for neuronal and glial cell markers. Ultrastructural changes were analyzed by electron microscopy. From 0 to 9 days in culture, there was progressive retinal degeneration, including early pyknosis of photoreceptor nuclei, cellular vacuolization in the ganglion cell layer, decrease of both plexiform layer thicknesses, disruption and truncation of photoreceptor outer segments (OS), and marked reduction in the number of nuclei at both nuclear layers where the cells were less densely packed. At 3 days there was swelling of cone OS with impairment of pedicles, loss of axons and dendrites of horizontal and rod bipolar cells that stained for calbindin (CB) and protein kinase C (PKC-α), respectively. After 9 days, horizontal cells were pyknotic and without terminal tips. There were similar degenerative processes in the outer plexiform layer for rod bipolar cells and loss of axon terminal lateral varicosities in the inner plexiform layer. Glial fibrillary acidic protein (GFAP) staining did not reveal a dramatic increase of gliosis in Müller cells. However, some Müller cells were CB immunoreactive at 6 days of culture. Over 9 days of culture, human neuroretina explants underwent morphological changes in photoreceptors, particularly the OS and axon terminals, and in postsynaptic horizontal and bipolar cells. These early changes, not previously described in cultured human samples, reproduce some celullar modifications after retinal damage. Thus, this model may be suitable to evaluate therapeutic agents during retinal degeneration processes.

A seriation of the late prehistoric Santa Maria culture of northwestern Argentina / Ronald L. Weber, Field Museum of Natural History.

v.68:no.2(1968)

Material culture of the Chilcotin Athapaskans of west central British Columbia : collections in the Field Museum of Natural History / James W. VanStone.

n.s. no.20(1993)

Material culture of the Blackfoot (Blood) Indians of southern Alberta / James W. VanStone.

n.s. no.19(1992)

Le développement de la citoyenneté de l’Union européenne = The development of citizenship in the European Union. Research Papers in Law, 1/2006

No abstract.

The Social Impact of Migration and the Notion of Citizenship for the EU. Ensuing challenges and opportunities for the Union. CEPS Commentaries, 13 March 2014

Documenting the unwelcoming treatment extended by government officials to the poorest EU citizens from other member states, including denying them their EU rights, Elspeth Guild censures these officials for shattering the principle of equality of citizens and of disaggregating Europe into nationals of the member states who can be treated differently simply on the basis of their origins.

DEMOCRACY AND CITIZENSHIP IN NORTH AFRICA AFTER THE ARAB AWAKENING: CHALLENGES FOR EU AND US FOREIGN POLICY (EUSPRING). Arab Citizenship Review No. 4, April 2014. Egypt. Egypt’s Transition in Crisis: The Decline of Citizenship Rights

This series of policy briefs provides a regular update of debates concerning key rights issues in three Arab states, Morocco, Egypt and Tunisia. In a first round of briefs on the three countries, we provide background on these debates since the beginning of the Arab spring.

DEMOCRACY AND CITIZENSHIP IN NORTH AFRICA AFTER THE ARAB AWAKENING: CHALLENGES FOR EU AND US FOREIGN POLICY (EUSPRING). Arab Citizenship Review No. 6, October 2014. EGYPT. The Return to Authoritarianism and the Crisis of Citizenship Rights

Citizenship and democratic rights have been shrinking in Egypt with the rise of president Abd El Fattah El Sisi, widely popular among Egyptians who fear more violence and unrest in an increasingly volatile region. In this EU Spring Policy Brief, Moataz El Fegiery examines the political landscape in the run-up of parliamentary elections, arguing that the short term is likely to see further curtailment of acquired rights, further crackdown on the opposition and consolidation of military power. In the longer term, however, it is in the interest of Egyptian society and institutions as well as of Europe to reverse the politics of exclusion and ensure that freedoms, pluralism and participation prevent the rise of extremism and political violence.

American flower-garden directory : containing practical directions for the culture of plants in the flower-garden, hot-house, green-house, rooms, or parlour windows, for every month of the year .../

Includes index.