Search results for "VITRO"
showing 10 items of 2786 documents
Polmunary epithelial barrier formation on biodegradable poly-L-lactic-acid (PLLA) membrane
2016
Aims: Investigation of epithelial barrier formation using PLLA membranes for application in bioengineering. Background: The development of functional and biocompatible substitutes for damaged tissue or organs is a major challenge in biomedical engineering. The epithelial barrier plays a central role in tissue homeostasis and immunity preventing damage and contamination of the interstitial tissues. Different in vitro models of the lung and intestinal epithelial barriers have been well characterized, however these tend to use non-biodegradable and/or poorly biocompatible scaffolds. Therefore, there is a need for better supports for epithelial cells for future applications in tissue engineerin…
The gap junctional intercellular communication is no prerequisite for the stabilization of xenobiotic metabolizing enzyme activities in primary rat l…
1995
In primary monocultures of adult rat liver parenchymal cells (PC), the activities of the xenobiotic metabolizing enzymes microsomal epoxide hydrolase (mEHb), soluble epoxide hydrolase (sEH), glutathione S-transferases (GST), and phenolsulfotransferase (ST) were reduced after 7 d to values below 33% of the initial activities. Furthermore, the gap junctional intercellular communication (GJIC), measured after microinjection by dye transfer, decreased from 90% on Day 1 to undetectable values after 5 d in monoculture. Co-culture of PC with nonparenchymal rat liver epithelial cells (NEC) increased (98% on Day 1) and stabilized (82% on Day 7) the homotypic GJIC of PC. Additionally, most of the mea…
A rapid rosetting method for separation of hemocyte sub-populations of Drosophila melanogaster.
2003
Hemocytes, cellular elements of the innate immune system in insects, play a crucial role in the cellular and humoral immune response. Although a significant amount of information has been collected on their differentiation and function, our understanding of hemocyte development is far from complete. Their characterisation is mostly based on morphological criteria. However, molecular markers were recently identified, defining functional subsets by the aid of monoclonal antibodies. Isolated subsets of hemocytes, in sufficient quantity and purity could help to analyse their development in vitro and also to further define their molecular characteristics. Here we describe an antibody-based roset…
Quantitative contributions of IgG, IgM and C3 to erythrophagocytosis and rosette formation by peritoneal macrophages, and anti-opsonin activity of de…
1976
In vitro phagocytosis by guinea pig peritoneal macrophages of immune complexes (EA) was shown to be dependent on IgG antibody in a dose-dependent fashion. C3b enhanced phagocytosis of EA at limited IgG antibody concentrations only. When IgM antibody was used for sensitization of sheep red blood cells (SRBC), phagocytosis and rosette formation did not occur in the absence of bound C3. The polyanion, dextran sulfate 500 (DS), was shown to depress both rosette formation and phagocytosis of EAIgG, C1423 and EAIgMC1423, as well as immune adherence of human group 0 erythrocytes and hemolytic activity of C3. This effect of DS was seen only when it was actually present in the incubation medium.
Predictive variables of in vitro fertilization and pre-implantation embryo development in the mouse
2002
The present study aims to analyze the cause-effect relationships among several in-vitro fertilization and pre-implantation embryo development variables in the mouse. Superovulation of hybrid (C57Bl/6JIco female X CBA/JIco male) female mice of 4-6 weeks of age was induced by a priming injection of pregnant mare's serum gonadotropin at the estrus stage of the estrous cycle followed after a 48-hr interval by human chrorionic gonadotropin. Ovulated cumulus-enclosed oocytes were inseminated with sperm from hybrid males of 12-16 weeks of age. The multiple linear regression analyses performed indicated that (a) total number of ovulated oocytes is a good predictor of both fertilization frequency an…
Concentration-Dependent Protection by Ethanol Extract of Propolis against γ-Ray-Induced Chromosome Damage in Human Blood Lymphocytes
2010
Radioprotection with natural products may be relevant to the mitigation of ionizing radiation-induced damage in mammalian systems; in this sense, propolis extracts have shown effects such as antioxidant, antitumoral, anti-inflammatory, and immunostimulant. We report for the first time a cytogenetic study to evaluate the radioprotective effect,in vitro, of propolis against radiation-induced chromosomal damage. Lymphocytes were cultured with increasing concentrations of ethanol extract of propolis (EEP), including 20, 40, 120, 250, 500, 750, 1000, and 2000 μg mL−1and then exposed to 2 Gyγ-rays. A significant and concentration-dependent decrease is observed in the frequency of chromosome aberr…
A neoepitope generated by an FLT3 internal tandem duplication (FLT3-ITD) is recognized by leukemia-reactive autologous CD8+ T cells.
2006
Abstract The FLT3 receptor tyrosine kinase is expressed in more than 90% of acute myelogeneous leukemias (AMLs), up to 30% of which carry an internal tandem duplication (ITD) within the FLT3 gene. Although varying duplication sites exist, most FLT3-ITDs affect a single protein domain. We analyzed the FLT3-ITD of an AML patient for encoding HLA class I–restricted immunogenic peptides. One of the tested peptides (YVDFREYEYY) induced in vitro autologous T-cell responses restricted by HLA-A*0101 that were also detectable ex vivo. These peptide-reactive T cells recognized targets transfected with the patient's FLT3-ITD, but not wild-type FLT3, and recognized the patient's AML cells. Our results …
Enhancing production and cytotoxic activity of polymeric soluble FasL-based chimeric proteins by concomitant expression of soluble FasL.
2012
International audience; Membrane FasL is the natural trigger of Fas-mediated apoptosis. A soluble homotrimeric counterpart (sFasL) also exists which is very weakly active, and needs oligomerization beyond its trimeric state to induce apoptosis. We recently generated a soluble FasL chimera by fusing the immunoglobulin-like domain of the leukemia inhibitory factor receptor gp190 to the extracellular region of human FasL, which enabled spontaneous dodecameric homotypic polymerization of FasL. This polymeric soluble human FasL (pFasL) displayed anti-tumoral activity in vitro and in vivo without systemic cytotoxicity in mouse. In the present work, we focused on the improvement of pFasL, with two…
Effect of simvastatin on desaturase activities in liver from lean and obese zucker rats
1993
The effect of simvastatin, a hypocholesterolemic drug, on the biosynthesis of arachidonic acid was studied in obese and lean Zucker rats. After administration of 2 mg/kg body weight/d for 13 d, delta 6 and delta 5 desaturase activities were measured in liver microsomes at two substrate concentrations. In untreated rats, the delta 6 desaturation rate was similar in the obese and lean rats when measured at saturating substrate levels, whereas delta 5 desaturation was lower in the obese animals. Treatment with simvastatin did not change delta 6 desaturation in either phenotype but increased delta 5 desaturation in obese rats to reach the unchanged rate observed in lean animals. The changes wer…
Effect of Salt-Loading and Spontaneous Hypertension on in Vitro Metabolism of [1-14C]Linoleic and [2-14C]Dihomo-γ-linolenic Acids
1993
The present study compared the effect of spontaneous hypertension and salt-loading on in vitro metabolism of 18:2n-6 (linoleic acid) and 20:3n-6 (dihomo-gamma-linolenic acid). Ten weanling spontaneously hypertensive rats (SHR) and 10 normotensive Wistar-Kyoto rats (WKY) maintained on a rodent lab chow were given tap water with (n = 5) or without (n = 5) addition of 1% NaCl for 4 weeks. Thereafter, animals were killed and liver microsomes were prepared. Aliquots of microsomes suspended in the phosphate-sucrose buffer containing MgCl2, ATP, CoA, and NADPH were incubated with 0.3 microCi of [1-14C]-18:2n-6 or [2-14C]-20:3n-6 at 37 degrees C for 15 min. The activity of delta 6- and delta 5-desa…