Search results for "rats"
showing 10 items of 3537 documents
Synthesis and cell surface display of class II determinants by long-term propagated rat T line cells
1987
We have investigated the capacity of the encephalitogenic BS rat T cell line bs 83 and its variant clone bs 83.III.C6 to synthesize and express RT1.B-specific class II molecule subsets defined by monoclonal antibodies (mAb) MRC-OX6 and MRC-OX3. Earlier studies had indicated that mAb MRC-OX6 recognizes three distinct molecular species: an immature oligomeric polypeptide chain complex comprised of the polymorphic subunits alpha, beta and the invariant proteins of the gamma group; a biosynthetic intermediate composed of post-translationally modified alpha, beta and gamma chain (denoted p35) and a fully glycosylated alpha, beta two-chain complex derived from the plasma membrane. MRC-OX3 was sho…
Study of the dynamics of biomolecules by high speed atomic force microscopy and surface enhanced Raman spectroscopy
2015
This thesis focuses on the coupling of High–Speed Atomic Force Microscopy (HS-AFM) and Surface Enhanced Raman Spectroscopy (SERS) for biomolecule analysis. We have designed a fabrication protocol to manufacture “SERS-active” substrates. The efficacy of gold, silver and gold-silver bimetallic crystalline nanoparticle substrates were evaluated. We have investigated the impact of optical and morphological features of the substrates on Raman signal intensity by analyzing well-known samples such as bipyridine ethylene and methylene blue molecules. We took an interest in three distinct biological problematics with HS-AFM and SERS analyses. First, we have detected the chemical signature of cytochr…
Electron Microscopic Contrast of the Cytoskeleton and Junctional Complexes of Intestinal Epithelial Cells by Ethanolic Phosphotungstic Acid
2000
After glutaraldehyde fixation and treatment with ethanolic phosphotungstic acid (E-PTA) before plastic embedding, sections of rat large intestine showed a characteristic electron contrasting pattern in epithelial cells. The axis of microvilli, terminal web, a thin band below the luminal plasma membrane, centrioles and junctional complexes (tight junctions, adherens junctions, and desmosomes) appeared highly contrasted. In addition to protein components of microfilaments and intermediate filaments, proteins from the junctional complexes could also be implicated in the contrasting reaction with E-PTA. Mitochondrial membranes, chromatin masses, and nucleoli of enterocytes showed considerable e…
Biodegradation of differently cross-linked collagen membranes: an experimental study in the rat.
2005
Contains fulltext : 47774.pdf (Publisher’s version ) (Closed access) The aim of the present study was to compare the biodegradation of differently cross-linked collagen membranes in rats. Five commercially available and three experimental membranes (VN) were included: (1) BioGide (BG) (non-cross-linked porcine type I and III collagens), (2) BioMend (BM), (3) BioMendExtend (BME) (glutaraldehyde cross-linked bovine type I collagen), (4) Ossix (OS) (enzymatic-cross-linked bovine type I collagen), (5) TutoDent (TD) (non-cross-linked bovine type I collagen, and (6-8) VN(1-3) (chemical cross-linked porcine type I and III collagens). Specimens were randomly allocated in unconnected subcutaneous po…
Tomografía computarizada aplicada al estudio del esqueleto de los primeros vertebrados
2022
Los conodontos son un grupo de vertebrados extintos que poseen unas piezas mineralizadas llamadas elementos conodontales. Aunque son importantes herramientas para datar y correlacionar, su importancia paleobiológica ha sido históricamente descuidada debido a su pequeño tamaño y las técnicas de estudio disponibles. El presente trabajo pretende hacer una revisión actualizada del conocimiento paleobiológico del grupo a la luz del uso de las nuevas técnicas tomográficas.
The effect of pregnancy on orthodontic tooth movement in rats
2012
Introduction: The purpose of this study was to investigate the effect of pregnancy on orthodontic tooth movement in Wistar rats. Material and Methods: Forty eight female three-month old Wistar rats with an average weight of 250 ±25 g r were selected and randomly divided into two experimental (pregnant) and control groups (non-pregnant). Maxillary central incisors were tipped distally by insertion of springs exerting 30g force. Two, seven and fourteen days after spring insertion animals were sacrificed. Then the mesioincisal distance between maxillary incisors were measured. Subsequently, histological sections were prepared to count osteoclasts under a light microscope. The data on the exten…
Effect of psychological stress on orthodontic tooth movement in rats
2010
Introduction: The purpose of this study was to investigate the effect of psychological stress on orthodontic tooth movement in Wistar rats. Materials and methods: Forty-eight female ten-week old Wistar rats with an average weight of 188 ±12 gr were selected and randomly divided into two experimental and control groups. The experimental group received crowded environment-induced and cat odour stresses 4 weeks before spring insertion. On the 29th day in both groups, maxillary incisors were moved by the insertion of springs and exactly after 7 days, 9 rats from each group and after 14 days the remaining rats were sacrificed. Then the mesioincisal distance between maxillary incisors was measure…
Étude de deux formations carbonifères du Morvan méridional dans le cadre de l'orogenèse hercynienne (Région du Creusot, Saône-et-Loire).
2006
18 pages; National audience; Dans la région creusotine, deux formations sédimentaires, l'une d'un âge incertain, Dévonien, Dévono-Dinantien, Dinantien, selon les auteurs, et l'autre du Stéphanien supérieur, ont été étudiées. La première nommée Formation (Fm) des Alouettes, est bordée au nord par le granite d'Uchon responsable d'un métamorphisme de contact. Des filons de microgranite la recoupent. Elle est d'abord constituée par une alternance de grès et de siltites laminées charbonneuses dans lesquelles on rencontre des rides de courant, figures d'érosion ainsi que des racines de Lépidophytes (Stigmaria) et des tiges d'Equisétales (Bornia). Cette partie est recouverte par des conglomérats à…
La transgression cénomanienne et l'âge des "Tourtias" du nord du bassin de Paris (F) et du bassin de Mons (B).
2010
29 pages; National audience
Stability of phospholipase D in primary astrocytes.
2002
Induction of expression and proteolytic breakdown of phospholipase D (PLD) isoforms in primary astrocyte cultures have been investigated. Astrocytes express both PLD1 and 2 and are dependent on PLD activity for cell proliferation [K. Kotter, J. Klein, J. Neurochem. 73 (1999) 2517]. Competitive RT-PCR analysis demonstrated a higher level of PLD1 mRNA than PLD2 mRNA (8.9 vs. 0.9amol/microg RNA, respectively). Treatment of astroglial cultures with the phorbol ester, 4beta-phorbol-12beta,13alpha-dibutyrate (0.1 microM), for 24-48h selectively induced PLD1b but not PLD1a or 2 expression as shown by PCR and Western blot; the effect was sensitive to Go 6976. In cells transiently permeabilized with…