Antibody enhancement of free-flow electrophoresis

Specific T cell clones and antibodies (ABs) were developed to study the efficiency of purifying closely associated T cells using Continuous Flow Electrophoresis System. Enhanced separation is accomplished by tagging cells first with ABs directed against the antigenic determinants on the cell surface and then with ABs against the Fc portion of the first AB. This second AB protrudes sufficiently beyond the cell membrane and glycocalyx to become the major overall cell surface potential determinant and thus causes a reduction of electrophoretic mobility. This project was divided into three phases. Phase one included development of specific T cell clones and separation of these specific clones. Phase two extends these principles to the separation of T cells from spleen cells and immunized lymph node cells. Phase three applies this double antibody technique to the separation of T cytotoxic cells from bone marrow

Molecular-specific urokinase antibodies

Antibodies have been developed against the different molecular forms of urokinase using synthetic peptides as immunogens. The peptides were synthesized specifically to represent those regions of the urokinase molecules which are exposed in the three-dimensional configuration of the molecule and are uniquely homologous to urokinase. Antibodies are directed against the lysine 158-isoleucine 159 peptide bond which is cleaved during activation from the single-chain (ScuPA) form to the bioactive double chain (54 KDa and 33 KDa) forms of urokinase and against the lysine 135 lysine 136 bond that is cleaved in the process of removing the alpha-chain from the 54 KDa form to produce the 33 KDa form of urokinase. These antibodies enable the direct measurement of the different molecular forms of urokinase from small samples of conditioned medium harvested from cell cultures

Antibodies Against Three Forms of Urokinase

Antibodies that bind to preselected regions of the urokinase molecule have been developed. These antibodies can be used to measure small quantities of each of three molecular forms of urokinase that could be contained in microsamples or conditioned media harvested from cultures of mammalian cells. Previously available antibodies and assay techniques do not yield both clear distinctions among, and measurements of, all three forms. Urokinase is a zymogen that is synthesized in a single-chain form, called ScuPA, which is composed of 411 amino acid residues (see figure). ScuPA has very little enzyme activity, but it can be activated in two ways: (1) by cleavage of the peptide bond lysine 158/isoleucine 159 and the loss of lysine 158 to obtain the high molecular-weight (HMW) form of the enzyme or (2) by cleavage of the bond lysine 135/lysine 136 to obtain the low-molecular-weight (LMW) form of the enzyme. The antibodies in question were produced in mice and rabbits by use of peptides as immunogens. The peptides were selected to obtain antibodies that bind to regions of ScuPA that include the lysine 158/isoleucine 159 and the lysine 135/lysine 136 bonds. The antibodies include monoclonal and polyclonal ones that yield indications as to whether either of these bonds is intact. The polyclonal antibodies include ones that preferentially bind to the HMW or LMW forms of the urokinase molecule. The monoclonal antibodies include ones that discriminate between the ScuPA and the HMW form. A combination of these molecular-specific antibodies will enable simultaneous assays of the ScuPA, HMW, and LMW forms in the same specimen of culture medium

Distribution of the different species of the Pseudallescheria boydii/Scedosporium apiospermum complex in French patients with cystic fibrosis

As various new sibling species within the Pseudallescheria boydii/Scedosporium apiospermum complex have been described recently with differences in their susceptibility to antifungals, this study was conducted in order to determine their respective frequency in cystic fibrosis. Results indicated that P. boydii largely predominated (62%), followed by S. apiospermum (24%), Scedosporium aurantiacum (10%) and Pseudallescheria minutispora (4%). Scedosporium dehoogii was not recovered in this study. The multiple correspondence factor analysis highlighted geographical discrepancies within species distribution: P. boydii was rarely encountered in Northern France, while S. apiospermum was less represented in the west of the country. Additionally, we demonstrated that all species encountered in the cystic fibrosis context were capable to chronically colonize the respiratory tract of patients. Molecular typing of a large set of environmental and clinical isolates should be conducted to delineate the epidemiology of each sibling species in the complex

Identification des réservoirs du complexe Scedosporium apiospermum au Maroc

Communications libresNational audienc

The contribution of deep learning to the semantic segmentation of 3D point-clouds in urban areas

peer reviewedSemantic segmentation in a large-scale urban environment is crucial for a deep and rigorous understanding of urban environments. The development of Lidar tools in terms of resolution and precision offers a good opportunity to satisfy the need of developing 3D city models. In this context, deep learning revolutionizes the field of computer vision and demonstrates a good performance in semantic segmentation. To achieve this objective, we propose to design a scientific methodology involving a method of deep learning by integrating several data sources (Lidar data, aerial images, etc) to recognize objects semantically and automatically. We aim at extracting automatically the maximum amount of semantic information in a urban environment with a high accuracy and performance

Prevalence of the sibling species of the Scedosporium apiospermum complex in cystic fibrosis context

Objectives: Cystic fibrosis is the most common genetic inherited disease in the European Caucasian population (frequency 1 out of 2500 births). Disease causes are mutations in the CFTR (cystic fibrosis transmembrane conductance regulator) gene, which encodes a chloride channel in the plasma membrane of several epithelial cells. However, prognosis essentially depends on the severity of the lesions in the lungs. The defective mucociliary clearance and the thickening of the bronchial mucus resulting from these mutations facilitate the entrapment of airborne microbes. Patients with such chronic pulmonary defect are at high risk for colonizations/infections by fungi, including the emergent pathogens of the Scedoporium apiospermum complex. This species complex ranks the second among the filamentous fungi colonizing the airways of CF patients. Recent molecular studies supported by morphological, physiological and genetic observations showed that the S. apiospermum complex comprises at least five distinct species. Antifungal susceptibility profiles and virulence of these sibling species showed differences. This study aims to determine the prevalence of the different species of S. apiospermum complex in the CF context and to analyze the chronic trait of these infections. Methods: A set of 50 epidemiologically unrelated isolates was analyzed to estimate the prevalence, all isolates having been recovered from distinct patients with CF followed up in different university hospitals from France and initially identified as belonging to the S. apiospermum complex. The internal transcribed spacer (ITS) regions 1 and 2 of the ribosomal RNA gene, a fragment of the nuclear gene calmodulin (CAL) and two regions (BT2 and TUB) within the ß-tubulin gene were amplified and sequenced as described by Gilgado et al. Additionally, sequential (from successive sputum samples from the same patient) and multiple (from the same clinical sample) isolates were genotyped by random amplification of polymorphic DNA (RAPD) using primers GC70, UBC-701 and UBC-703. Results and conclusion: Pseudallescheria boydii was the most common specie encountered (62% of the isolates) in the CF context, followed by S. apiospermum sensu stricto (24%) and S. aurantiacum (10%). These results contrast with the natural occurrence of these species in the environment, reinforcing the need for further studies aiming to elucidate the pathogenic mechanisms of these fungi. As reported by Kalsteis et al., S. apiospermum sensu stricto is the most prevalent specie in the environment, accounting for 58.7–77.7% of the isolates (depending on the habitat studied), while low prevalence were found for S. aurantiacum and P. boydii, which represented 4.8 (industrial areas) to 7.7% (parks and playgrounds) and 1.9–2.3% of the isolates, respectively. Likewise, Scedosporium dehoogii, which represented about 13.8–28.8% of the isolates from environmental samples, has not been described in a clinical context as yet. Moreover, our results suggest a clustering according to the geographic origin of the isolates: CF patients from the West of France were predominantly colonized by P. boydii. Events of chronic colonization were observed for each specie of S. apiospermum complex encountered in CF context. The RAPD genotyping demonstrated also that two different species could concomitantly colonize the same patient.