1,720,964 research outputs found
A new respirometric endpoint-based biosensor to assess the relative toxicity of chemicals on immobilized human cells
No full textCytological evidence for 5-azacytidine-induced demethylation of the heterochromatic regions of human chromosomes
No full textPersistence of increased levels of ribosomal gene activity in CHO-K1 cells treated in vitro with demethylating agents
No full textA new respirometric endpoint-based biosensor to assess the relative toxicity of chemicals on immobilized human cells
No full textSeveral functional and biochemical parameters have been proposed as biomarkers of effect of environmental pollutants. A rapid biosensor working with immobilized human U-937 cells was developed and applied to environmentally relevant chemicals with different structures and toxicological pathways, i.e. benzalkonium chloride, clofibric acid, diclofenac, mercury nitrate, ofloxacin, and sodium dodecyl sulphate. Respiration of cells was relied upon as a comprehensive biochemical effect for screening purposes. Analytical parameter (?ppmO2) and toxicological index (respiratory inhibition, ?%) measured after 1 h of exposure were utilized for dose–response relationship study. Results (toxicity rating scales based on ?50% and steepness) were compared with those obtained by the same approach previously optimized on Saccharomyces cerevisiae. The toxicity rating scale obtained by the biomarker based on human mitochondrial and cell metabolic activities compared well with previous scale obtained on yeast cells and with available in-vivo acute toxicity indexes; respiration was confirmed as toxicological endpoint reliably measurable by the biosensor
Anti 5-methylcytosine antibodies as a tool for detecting in mammalian cells spontaneous or induced DNA hypo and hypermethylation associated with chromatin compaction
No full textComputer assisted analysis of the methylation status of individual interphase nuclei in human cultured cells.
No full textMethylation levels of normal and chronic lymphocytic leukemia B lymphocytes: Computer-assisted quantitative analysis of anti-5-methylcytosine antibody binding to individual binding.
No full textThe Loss of Methyl Groups in DNA of Tumor Cells and Tissues: The Immunochemical Approach
No full textNuclear methylation levels in normal and cancerous thyroid cells
No full textBackground: Most cancers show abnormal DNA methylation and a positive correlation between hypomethylation and tumour progression. Patients and Methods: In our laboratory the extent of DNA methylation in individual nuclei in normal, cancer and non-cancer thyroid tissue samples was quantified according to a previously described method of computer-assisted semi-quantitative analysis. Cancer and non-cancer samples were obtained from nine patients with different thyroid pathologies (one multinodular goitre and eight carcinomas). Quantitative analysis was performed in two sets of samples, i.e. individual nuclei from touch preparations and from tissue sections. Results: In all cancer specimens a statistically significant decrease of heterochromatin methylation was consistently observed. In both sets of samples a direct cot-relation was consistently observed between the extent of chromatin demethylation and the degree of malignancy. Conclusion: Our preliminary results suggest that our method of cell-by-cell detection of intranuclear methylation abnormalities may be a useful tool in early identification of thyroid cancer lesions
DNA methylation of peripheral blood lymphocyte level in healthy subjects matched for MTHFR gene polymorphism and smoking habit.
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