1,720,977 research outputs found
HETEROGENEITY OF DNA AND RNA IN HUNTER PATIENTS
No full textGenomic DNA and total RNA from lymphoblasts of nine unrelated Italian patients affected with Hunter syndrome were analyzed using a human cDNA clone coding for the lysosomal enzyme iduronate-2-sulphatase (IDS). Southern blot analysis resulted in patterns similar to the normal control for seven of the patients analyzed; an aberrant pattern was observed in two patients (F.N. and P.D.), suggesting deletions/rearrangement in the IDS gene. Northern blot analysis showed in seven patients, a pattern similar to the normal control; for patients F.N. and P.D. the pattern was atypical, i.e., normal RNA species were absent whereas two different transcripts occurred. These data confirm the heterogeneity of the molecular defects causing Hunter disease. © 1993 Springer-Verlag
SECRETION AND INCREASE OF INTRACELLULAR CuZn SUPEROXIDE DISMUTASE CONTENT IN HUMAN NEUROBLASTOMA SK-N-BE CELLS SUBJECTED TO OXIDATIVE STRESS
No full textCuZn superoxide dismutase (SOD) secretion was detected in media of [S-35]cysteine-labeled human neuroblastoma SK-N-BE cells precipitated with antihuman CuZn SOD antibodies. The ability of Fe2+/ascorbate oxidative stress to induce CuZn SOD in SK-N-BE cells was evaluated by Western blot analysis. The results showed that, like human hepatocarcinoma cells and human fibroblasts, SK-N-BE cells secrete CuZn SOD. In addition, the CuZn SOD concentration was higher in cells subjected to oxidative stress than in unstressed cells. The secretion of CuZn SOD and the ability of Fe2+/ascorbate to increase its protein content in SK-N-BE cells indicates that this enzyme protects the brain from damage induced by oxidative stress. (C) 1998 Elsevier Science Inc
Inhibitors of Ras farnesylation revert the increased resistance tooxidative stress in K-Ras transformed NIH 3T3 cells.
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Cell-to-cell contact between normal fibroblasts and lymphoblasts deficient in lysosomal enzymes.
No full textCell-to-cell contact between normal fibroblasts and lymphoblasts deficient in lysosomal enzymes.
No full textHuman lymphoblasts deficient in iduronate sulfatase or in α-N-acetylglucosaminidase acquire discrete levels of enzyme activity after co-culture with human normal skin fibroblasts. This occurs by direct cell-to-cell contact and not by uptake of secreted fibroblast enzyme. The process is dependent on time and on the number of fibroblasts used. Electron-microscopic examination of the co-culture of the two cell types reveals extensive region of intimate contact. Fibroblastic projections appear frequently in close apposition witt lymphoblast invaginations; a diffuse micropinocytotic activity is evident only in fibroblastic cells. © 1992
Inhibitors of Ras farnesylation revert the increased resistance to oxidative stress in K-Ras transformed NIH 3T3 cells.
Full text linkFree fatty acids modulate LDL receptor activity in BHK-21 cells
No full textIt has been shown that dietary fatty acids affect serum low density lipoprotein (LDL) levels, but the mechanism responsible for this effect is still under debate. Here we investigate the effect of different free fatty acids on LDL receptor activity in BHK-21 cells. These cells possess a classical LDL receptor strongly regulated by substances like 25-OH-cholesterol or lovastatin. Preincubation of cells for 24 h with both oleic (cis 18:1) and its trans counterpart, elaidic acid, enhanced 125I-LDL binding, internalization and degradation, being oleic acid more effective than elaidic acid. Among polyunsaturated fatty acids (PUFA) of the n-6 series arachidonic acid (20:4) enhanced LDL receptor activity more than linoleic acid (18:2), and among PUFA of the n-3 series docosahexaenoic (22:6) and eicosapentaenoic acids (20:5) were more effective compared to alpha-linolenic acid (18:3). Conversely, preincubation of cells with saturated fatty acids, palmitic (16:0) and stearic (18:0) acids, decreased binding, internalization and degradation of 125I-LDL. Scatchard analysis of binding data obtained with palmitic and oleic acids showed that these two fatty acids affect LDL receptor number without altering receptor affinity. The regulatory effect of free fatty acids on LDL receptor activity in BHK-21 cells is consistent with the hypothesis that the ability of fatty acids to modulate LDL-cholesterol levels in vivo is mediated, at least in part, by an action on receptor-dependent uptake of LDL
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