Retinal ganglion cell degeneration is supposed to be mediated by reactive oxygen species (ROS) and advanced glycation end products (AGEs). The alpha2-adrenergic agonist, 5-bromo-N-(4,5-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine (brimonidine; UK-14,304), is said to exert a neuroprotective effect. To investigate these mechanisms in detail, we exposed rat whole mounts to glyoxal or H(2)O(2) and treated them with either UK-14,304 alone or additionally with the phosphatidylinositide 3 kinase (PI3) kinase inhibitor, 2-(4-Morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (Ly 294002).
View Article and Find Full Text PDFPurpose: Methylglyoxal and glyoxal are intermediates of advanced glycation end products (AGEs). These substances, as well as hydrogen peroxide, induce retinal neurons to reduce their intracellular pH and augment their production of reactive oxygen species, leading to apoptosis. Because these processes may play a role in diabetic retinopathy, the authors undertook this study to investigate the protective action of dorzolamide, an inhibitor of carbonic anhydrase, on retinal neural cells.
View Article and Find Full Text PDFThe ganglioside GD3 (Neu5Ac alpha8Neu5Ac alpha3Gal beta4GlcCer) is an intracellular lipid messenger that induces apoptosis by targeting mitochondria in various cell types. GD3 can also promote apoptosis when externally added to cells. Previous studies showed that the proapoptotic effects of GD3 can be counteracted by 9-O-acetylation.
View Article and Find Full Text PDFGraefes Arch Clin Exp Ophthalmol
December 2002
Background: Methylglyoxal and glyoxal, intermediate products of glycation, are known to accelerate glycation and the formation of advanced glycation endproducts (AGEs). These mechanisms may play a role in the degenerative progression of diabetic retinopathy and macular degeneration. The present study was undertaken to elucidate the retinal neurotoxicity of the Maillard reaction intermediate alpha-oxoaldehyde glyoxal.
View Article and Find Full Text PDFCarbohydr Res
December 2000
About 25-35% of human T cells display the CDw60 ganglioside (9-O-acetyl-GD3) antigen at the cell surface [E.P. Rieber, in W.
View Article and Find Full Text PDFStimulation of human monocyte-derived-macrophages (MDM) with interferon gamma induces the L-tryptophan degrading enzyme indoleamine 2,3-dioxygenase (IDO). It has been well documented that the growth of some intra-cellular parasites such as Chlamydia and Toxoplasma in human fibroblasts and glioblastoma cells is inhibited by IDO mediated L-tryptophan depletion. We have recently shown that IDO induction in cord blood MDM is also responsible for the growth inhibition of extra-cellular group B streptococci and thus for the first time shown an anti-bacterial effect of IDO activation.
View Article and Find Full Text PDFStimulation with lipopolysaccharide (LPS) initiated monocytes to produce interleukin-2 receptor light chain (p55 IL-2R). After stimulation with LPS for 48 hr, considerable quantities of soluble IL-2R were found in the supernatants of monocytes, exceeding even the amount of soluble IL-2R produced by activated T lymphocytes. Cell-associated p55 IL-2R was also increased during the first 24 hr of stimulation, after which time it remained constant.
View Article and Find Full Text PDFMouse macrophage precursor cells with natural killer (NK) like activity, derived from in vitro culture of light-fraction-bone marrow cells in the presence of colony-stimulating factor 1 (CSF-1) and low dose IL-2, were incubated with high dose (1000 U/ml) IL-2. After 3 days of incubation, cells had developed from NK like (killing Yac-1 but not P815) into LAK-like (killing both YAC-1 and P815) effector cells. Morphological studies revealed that LAK activity occurred at the time when macrophage precursors with NK like activity containing few cytoplasmic granules had further differentiated into cells with abundant azurophilic granules in their cytoplasma.
View Article and Find Full Text PDFRecombinant mouse interferon-gamma (IFN-gamma) was encapsulated into multilamellar vesicles and the proportion of encapsulated IFN-gamma determined by biological activity was 19%. The distribution of 125I-labeled IFN-gamma liposomes in C57BL/6 mice was analyzed. After an initial enrichment of liposomes in lung, more than 60% of total 125I-labeled IFN-gamma was accumulated in spleen and liver.
View Article and Find Full Text PDFThis report describes a clinical trial with Interleukin 2 (IL-2) on a 17-month old male child with combined immunodeficiency (Nezelof's syndrome). IL-2 was prepared from conditioned media of phytohemagglutinin-stimulated leukocytes from buffy coats. The purification of IL-2 involved chromatography on Matrex Blue A sepharose and gel filtration chromatography.
View Article and Find Full Text PDFInterleukin 2 was purified 100 000-fold to apparent homogeneity from the supernatants of mitogen-stimulated human blood leukocytes. A sequence of three purification steps was used: affinity chromatography on the bound dye cibacron blue, gel filtration on Ultrogel AcA44, and reversed-phase high-performance liquid chromatography on hexyl phase. The resulting interleukin 2 had a specific activity of 2 X 10(6) U/mg protein, and was free of pyrogenicity in the rabbit test.
View Article and Find Full Text PDFMacrophage cytotoxicity factor (MCF) was purified in 3 consecutive steps including adsorption chromatography on Matrex Gel Red A, hydrophobic chromatography on phenylalanine-Sepharose, and isoelectric focusing. MCF was characterized as a protein with a m.w.
View Article and Find Full Text PDFSupernatants from Concanavalin A-stimulated murine spleen cells were subjected to hydrophobic interaction chromatography on phenyl-Sepharose. Macrophage cytotoxicity factor (MCF), macrophage migration inhibitory factor (MIF), T-helper cell-replacing factor (TRF) and colony-stimulating factor (CSF) were bound at high ionic strength and were released stepwise at low ionic strength. CSF thus could be separated from MCF, MIF and TRF and the bulk of other proteins.
View Article and Find Full Text PDF