Yolanda Lorenzo

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The role of dietary antioxidants in human health remains controversial. Fruits and vegetables in the diet are associated with lower rates of chronic disease, and this is often attributed to their content of antioxidants, and a resulting protection against oxidative stress. However, large-scale human trials with antioxidant supplements have shown, if(More)
DNA damage is commonly measured at the level of individual cells using the so-called comet assay (single-cell gel electrophoresis). As the frequency of DNA breaks increases, so does the fraction of the DNA extending towards the anode, forming the comet tail. Comets with almost all DNA in the tail are often referred to as 'hedgehog' comets and are widely(More)
MicroRNAs (miRNAs) are noncoding RNAs that regulate expression of target mRNAs and are controlled by tumor suppressors and oncogenes. Altered expression of specific miRNAs in several tumor types and its association with poor prognosis parameters have been reported. Fewer data are available on its impact on patients' survival. We studied the impact of the(More)
The comet assay is a valuable experimental tool aimed at mapping DNA damage in human cells in vivo for environmental and occupational monitoring, as well as for therapeutic purposes, such as storage prior to transplant, during tissue engineering, and in experimental ex vivo assays. Furthermore, due to its great versatility, the comet assay allows to explore(More)
INTRODUCTION Deregulation of Polycomb member Bmi-1 is involved in cell proliferation and human oncogenesis. Modulation of Bmi-1 is found in several tumor tissues, including primary breast carcinomas; however, analysis of Bmi-1 in plasma of cancer patients has not been reported. This is the first study that evaluates Bmi-1 in plasma by using a large series(More)
We studied by real-time PCR cyclin D1 and thymidylate synthase (TS) mRNA in plasma as possible markers of clinical outcome in breast cancer. We observed poor outcome in patients with presence of cyclin D1 mRNA in good-prognosis groups, such as negative vascular invasion. Presence of both markers was associated with non-response to treatment after relapse.(More)
Experiments were conducted to determine the validity of two common genotoxicity testing procedures, the comet assay and the micronucleus (MN) test, when applied to nanoparticles (NP). The comet assay is used to detect strand breaks (SB) induced in cellular DNA. There is a possibility of obtaining false positive results, if residual NP remain in proximity to(More)
The comet assay (single-cell gel electrophoresis) is a sensitive and simple method for measuring DNA damage. An early modification of the assay involved the application of specific repair endonucleases to convert lesions to breaks; thus, for example, endonuclease III was used to measure oxidized pyrimidines. This concept has now been extended to produce an(More)
Nanogenotoxicity is a crucial endpoint in safety testing of nanomaterials as it addresses potential mutagenicity, which has implications for risks of both genetic disease and carcinogenesis. Within the NanoTEST project, we investigated the genotoxic potential of well-characterised nanoparticles (NPs): titanium dioxide (TiO2) NPs of nominal size 20 nm, iron(More)
AIMS Dietary antioxidants, including vitamin C, may be in part responsible for the cancer-preventive effects of fruits and vegetables. Human intervention trials with clinical endpoints have failed to confirm their protective effects, and mechanistic studies have given inconsistent results. Our aim was to investigate antioxidant/ pro-oxidant effects of(More)