B cells in ADA deficiency

Deficiency of the enzyme adenosine deaminase (ADA) results in severe lymphopenia in humans. Mice with an inactivating mutation in the ADA gene also exhibit profound lymphopenia, as well as pulmonary insufficiency and ribcage abnormalities. In fact, the mouse model has a phenotype that is remarkably similar to that of the human disease, making the mice valuable tools for unraveling the mechanism of lymphocyte destruction in absence of this housekeeping gene. T cell deficiency in ADA deficiency has been extensively studied by others, revealing a block in early thymocyte development. In contrast, our studies revealed that early B cell development in the bone marrow is normal. ADA-deficient mice, however, exhibit profound defects in germinal center formation, preventing antigen-dependent B cell maturation in the spleen. ADA-deficient spleen B cells display significant defects in proliferation and activation signaling, and produce more IgM than their normal counterparts, suggesting that extrafollicular plasmablasts are overrepresented. B cells from ADA-deficient mouse spleens undergo apoptosis more readily than those from normal mouse spleens. Levels of ADA's substrates, adenosine and 2′-deoxyadenosine, are elevated in both bone marrow and spleen in ADA-deficient mice. S ′-adenosyihomoeysteine hydrolase (SAH hydrolase) activity is significantly inhibited in both locales, as well. dATP levels, though, are only elevated in spleen, where B cell development is impaired, and not in bone marrow, where B cell ontogeny is normal. This finding points to dATP as the causative agent of lymphocyte death in ADA deficiency. ADA deficiency results in inhibition of the enzyme ribonucleotide reductase, thereby depleting nucleoside pools needed for DNA repair. Another mouse model that lacks a functional gene encoding a protein involved in DNA repair and/or cell cycle checkpoint regulation, p53-binding protein 1, exhibits blocks in T and B cell development that are similar to those seen in ADA-deficient mice. Unraveling the mechanisms of lymphocyte destruction in ADA deficiency may further understanding of lymphocyte biology, facilitate better chemotherapeutic treatment for lymphoproliferative diseases, and improve gene and enzyme therapy regimens attempted for ADA deficiency. ^

Ada Westhofen-Robinson, Brustbild

Signatur des Originals: S 36/F06032

Ada Westhofen-Robinson, Rollenbild, in: Carl Maria von Weber: Oberon

Signatur des Originals: S 36/F06033

Ada von Westhoven-Robinson, Brustbild

Signatur des Originals: S 36/F07227

Ada Cavendish, Rollenbild, Kniestück, Profil

Signatur des Originals: S 36/F08366

Ada Kilian, Rollenbild, Brustbild

Signatur des Originals: S 36/F08939

Ada Neilson als Queen Elizabeth, Rollenbild, Kniestück, in: The Armada

Signatur des Originals: S 36/F09403

Ada Neilson als Queen Elizabeth, Szenenfoto, in: The Armada

Signatur des Originals: S 36/F09404

Liane Haid als Ada Rasmus, Rollenbild, Brustbild, Profil, in: Hermann Grund: Die unvollkommene Liebe

Signatur des Originals: S 36/F10744

Ada Adini, Brustbild, Profil

Signatur des Originals: S 36/G04545

M. B. Royo y S. E. Wendt (ed.). Homenaje a Aída Barbagelata. In Memorian, Buenos Aires, Actualidad Producciones, 1994, 2 tomos, 461 y 555 pp.

Fil: Nápoli, Juan Tobías. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

M. B. Royo y S. E. Wendt (ed.). Homenaje a Aída Barbagelata. In Memorian, Buenos Aires, Actualidad Producciones, 1994, 2 tomos, 461 y 555 pp.

Fil: Nápoli, Juan Tobías. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Behavior competence development through e-learning: experience at the undergraduate level in the context of Aula a Distancia Abierta (ADA) Madrid, Spain

This communication presents the results of an innovative approach for competencedevelopment suggesting a new methodology for the integration of these elements in professional development within the ADA initiative (AulaaDistanciaAbierta, Distance and Open Classroom) of the Community of Madrid. The main objective of this initiative is to promote the use of Information and Communication Technologies (ICTs) for educational activities by creating a new learning environment structured on the premises of commitment to self–learning, individual work, communication and virtual interaction, and self and continuous assessment. Results from this experience showed that conceptualization is a positive contribution to learning, as students added names and characteristics to competences and abilities that were previously unknown or underestimated. Also, the diversity of participants’ disciplines indicated multidimensional interest in this idea and supported the theory that this approach to competencedevelopment could be successful in all knowledge areas.

Ada User Guide for LEGO MINDSTORMS NXT

The purpose of this guide is to introduce the robotics kit LEGO MINDSTORMS NXT to the Ada community. All the steps required to complete a working Ada application running under the LEGO MINDSTORMS NXT are covered..