A new monoclonal antibody (3D3) generated with human respiratory mucins and directed against Lewis determinants

We have prepared a monoclonal antibody (MAb), 3D3, raised againstpurified human respiratory mucins. This antibody recognizedmucins and proteolytically derived glycopeptides. The epitoperecognized by the antibody was destroyed by -L-fucosidase, indicatingthat it was present on the carbohydrate moieties. Structuralspecificity was determined by adsorption on a variety of synthetic,insolubilized oligosaccharides. Several lines of evidence indicatethat the 3D3 MAb reacted strongly with the Lewis (Le^b) antigen,but also recognized Le^a and Le^y determinants. This antibodymight be useful to study mucin secretion. human bronchial mucins Lewis b     

Five specificity patterns of (1----3)-alpha-L-fucosyltransferase activity defined by use of synthetic oligosaccharide acceptors. Differential expression of the enzymes during human embryonic development and in adult tissues.

The use of synthetic trisaccharides as acceptors led to the definition of five main (1----3)-alpha-L-fucosyltransferase activity patterns in human adult tissues: (I). Myeliod cells, granulocytes, monocytes, and lymphoblasts, transfer an alpha-L-fucopyranosyl group to O-3 of a 2-acetamido-2-deoxy-D-glucosyl residue of H blood-group Type 2 oligosaccharide [alpha-L-Fucp-(1----2)-beta-D-Galp-(1----4)-beta-D-GlcpNAc----R] with Mn2+ as activator. (II) Brain has the same acceptor specificity pattern as myeloid cells, but can also use Co2+ as activator. (III) Plasma and liver transfer an alpha-L-furopyranosyl group to H blood-group Type 2 and to sialyl-N-acetyllactosamine [alpha-NeuAc-(2----3)-beta-D-Galp-(1----4)-beta-D-GlcpNAc----R]. (IV) Intestine, gall bladder, kidney, and milk have the same activity as (III), but also transfer an alpha-L-fucopyranosyl group to O-4 of a 2-acetamido-2-deoxy-D-glucose residue of H blood-group Type 1 [alpha-L-Fucp-(1----2)-beta-D-Galp-(1----3)-beta-D-GlcpNAc----R] and sialyl Type 1 [alpha-NeuAc-(1----3)-beta-D-Galp-(1----3)-beta-D-GlcpNAc----R]. (V) Stomach mucosa is not able to use sialyl-N-acetyllactosamine, but can transfer an alpha-L-fucopyranosyl group to the other Type 1 and Type 2 acceptors. Unlike in adult tissue, a single myeloid-like pattern of (1----3)-alpha-L-fucosyltransferase activity was found at early stages of development in all tissues tested. This embryonic enzyme is later progressively replaced by enzymes or mixtures of enzymes having the corresponding adult patterns of enzyme expression. All lymphoblastoid cell lines and half of the tumor epithelial cell lines tested expressed the myeloid-like pattern of enzyme found in normal embryonic tissues. The remaining tumor epithelial cell lines expressed different forms of (1----3/4)-alpha-L-fucosyltransferase acceptor specificity patterns.     

Insights into the expression of ABH and Lewis antigens through human bone marrow transplantation.

Twelve information bone marrow transplants, with at least one difference in ABO and/or Lewis types between donor and recipient, were retrospectively studied. ABH and Lewis antigens were determined in plasma, erythrocytes, and lymphocytes. Donor lymphocytes acquired the ABH and Lewis antigens from the recipient's plasma in the same way that donor erythrocytes acquired the Lewis antigens from it. Lymphocytotoxicity detected type 1 ABH and Lewis antigens only, providing evidence for the existence of combined ABH and Lewis antigens on lymphocytes. This was in contrast with the ABH antigens on type 2 chains of red cells, which are devoid of Lewis specificities. The differences in genetic control, probable chemical structure, and cellular origin of these two types of ABH antigens are presented in a theoretical model that accounts for most of the known data.     

A new hadrosaurid dentary from the latest Maastrichtian of the Pyrenees (north Spain) and the high diversity of the duck-billed dinosaurs of the Ibero-Armorican Realm at the very end of the Cretaceous

In the latest Maastrichtian, the European hadrosauroid fauna was more diverse than those of North America and Asia. The European record of hadrosaurid dentaries is an example of this diversity, and most of the sites with mandibular remains are located in the Ibero-Armorican Realm. Within the Iberian Peninsula, most of the remains are located in the Tremp Basin (South Central Pyrenees). Two of the three valid hadrosaurid taxa defined in this basin are from the Blasi sites (Arén, Huesca province): Arenysaurus ardevoli (Blasi-3) and Blasisaurus canudoi (Blasi-1). A new locality in Blasi (Blasi 3.4) has provided a new dentary from an indeterminate euhadrosaurid. This dentary presents some characters intermediate between Arenysaurus and Blasisaurus, some characters similar to Pararhabdodon isonensis (from the nearby province of Lleida), and some characters of its own. Nevertheless, due to its fragmentary character, without dentition or its edentulous anterior part, it cannot be determined above the level of Euhadrosauria. It thus represents a fourth Iberian euhadrosaurian taxon in the Ibero-Armorican Realm, different from Arenysaurus, Blasisaurus and Pararhabdodon, increasing the diversity of hadrosauroids in this realm at the very end of the Cretaceous.     

Towards Productive Cities: Environmental Assessment of the Food‐Energy‐Water Nexus of the Urban Roof Mosaic

Cities are rapidly growing and need to look for ways to optimize resource consumption. Metropolises are especially vulnerable in three main systems, often referred to as the FEW (i.e., food, energy, and water) nexus. In this context, urban rooftops are underutilized areas that might be used for the production of these resources. We developed the Roof Mosaic approach, which combines life cycle assessment with two rooftop guidelines, to analyze the technical feasibility and environmental implications of producing food and energy, and harvesting rainwater on rooftops through different combinations at different scales. To illustrate, we apply the Roof Mosaic approach to a densely populated neighborhood in a Mediterranean city. The building‐scale results show that integrating rainwater harvesting and food production would avoid relatively insignificant emissions (13.9–18.6 kg CO₂ eq/inhabitant/year) in the use stage, but their construction would have low environmental impacts. In contrast, the application of energy systems (photovoltaic or solar thermal systems) combined with rainwater harvesting could potentially avoid higher CO₂ eq emissions (177–196 kg CO₂ eq/inhabitant/year) but generate higher environmental burdens in the construction phase. When applied at the neighborhood scale, the approach can be optimized to meet between 7% and 50% of FEW demands and avoid up to 157 tons CO₂ eq/year. This approach is a useful guide to optimize the FEW nexus providing a range of options for the exploitation of rooftops at the local scale, which can aid cities in becoming self‐sufficient, optimizing resources, and reducing CO₂ eq emissions.     

Robustness and stability of the gene regulatory network involved in DV boundary formation in the Drosophila wing

Gene regulatory networks have been conserved during evolution. The Drosophila wing and the vertebrate hindbrain share the gene network involved in the establishment of the boundary between dorsal and ventral compartments in the wing and adjacent rhombomeres in the hindbrain. A positive feedback-loop between boundary and non-boundary cells and mediated by the activities of Notch and Wingless/Wnt-1 leads to the establishment of a Notch dependent organizer at the boundary. By means of a Systems Biology approach that combines mathematical modeling and both in silico and in vivo experiments in the Drosophila wing primordium, we modeled and tested this regulatory network and present evidence that a novel property, namely refractoriness to the Wingless signaling molecule, is required in boundary cells for the formation of a stable dorsal-ventral boundary. This new property has been validated in vivo, promotes mutually exclusive domains of Notch and Wingless activities and confers stability to the dorsal-ventral boundary. A robustness analysis of the regulatory network complements our results and ensures its biological plausibility.     

Xenotransplantation: the importance of the Galalpha1,3Gal epitope in hyperacute vascular rejection

The transplantation of organs from other species into humans is considered to be a potential solution to the shortage of human donor organs. Organ transplantation from pig to human, however, results in hyperacute rejection, initiated by the binding of human natural antidonor antibody and complement. The major target antigen of this natural antibody is the terminal disaccharide Galalphal,3Gal, which is synthesized by Galbeta1,4GlcNAc alpha1,3-galactosyltransferase. Here we review our current knowledge of this key enzyme. A better understanding of structure, enzyme properties, and expression pattern of alpha1,3-galactosyltransferase has opened up several novel therapeutic approaches to prevent hyperacute vascular rejection. Cloning, and expression in vitro of the corresponding cDNA, has allowed to develop strategies to induce immune tolerance, and deplete or neutralize the natural xenoreactive antibody. Elucidation of the genomic structure has led to the production of transgenic animals that are lacking alpha1,3-galactosyltransferase activity. A detailed knowledge of the enzyme properties has formed the basis of approaches to modify donor organ glycosylation by intracellular competition. Study of the expression pattern of alpha1,3-galactosyltransferase has helped to understand the mechanism of hyperacute rejection in discordant xenotransplantation, and that of complement-mediated, natural immunity against interspecies transmission of retroviruses.