María José Hazen

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The occurrence and fate of additives in the aquatic environment is an emerging issue in environmental chemistry. This paper describes the ecotoxicological effects of the commonly used additive butylated hydroxyanisole (BHA) using a test battery, comprising of several different organisms and in vitro test systems, representing a proportion of the different(More)
Twenty habitually omnivorous subjects and 19 habitually lactoovovegetarian subjects aged 59-65 y collected feces during 4 consecutive days. The concentrations of bile acids in total feces did not differ between the omnivores and vegetarians, but the bile acid concentrations in fecal water were significantly lower in the vegetarians. The concentration of the(More)
The ever growing anthropogenic pressure to the environment has lead in 2007 to the revision of the existing legislation and the approval of the new European law regarding the production and importation of chemicals, known as REACH. This new legal framework supports the development of alternative methods to animal experimentation encouraging the improvement(More)
Butylated hydroxyanisole and propylparaben are phenolic preservatives commonly used in food, pharmaceutical and personal care products. Both chemicals have been subjected to extensive toxicological studies, due to the growing concern regarding their possible impacts on environmental and human health. However, the cytotoxicity and underlying mechanisms of(More)
The cytotoxic effect caused by the hypomethylating agent S-adenosyl-L-homocysteine (SAH) was compared with that of two drugs commonly used to induce DNA hypomethylation, 5-azacytidine and 5-aza-2′-deocycytidine. Two in vitro cytotoxicity tests, the tetrazolium MTT assay and the intracellular lactate dehydrogenase (LDH) activity test, suggest that SAH(More)
Propyl p-hydroxybenzoate, commonly referred to as propylparaben, is the most frequently used preservative to inhibit microbial growth and extend shelf life of a range of consumer products. The objective of this study was to provide further insight into the toxicological profile of this compound, because of the current discrepancy in the literature with(More)
The in vivo uptake of two cationic porphyrins: mesotetra (4-N-methylpyridyl) porphine (T4MPyP) and its zinc complex (ZnT4MPyP) was determined in Allium cepa meristematic cells. Both photosensitizers (10(-7) M for 4 h) penetrated into the nucleus producing a red fluorescence of chromatin under blue-violet (436 nm) exciting light. The ability of T4MPyP and(More)
The effects of pentachlorophenol have been studied on diverse biological systems both in vivo and in vitro, however the cellular basis of the pronounced cytotoxicity of this organochlorine compound is poorly understood. In this work, morphological and biochemical analyses were carried out to identify the primary targets of pentachlorophenol toxicity in(More)
Di(2-ethylhexyl)phthalate, triclosan and propylparaben are contaminants of emerging concern that have been subjected to extensive toxicological studies, but for which limited information is currently available concerning adverse effects on terrestrial plant systems. The Allium cepa test, which is considered one of the most efficient approaches to assess(More)
In the present work, we have continued our studies on harmine phototoxicity in human tumour cells. The toxicity of harmine in the dark was analysed by a quantitative neutral red uptake assay, and subcellular sensitive targets following harmine photosensitization were de fi ned by electron microscopic analysis of HeLa cells. The results obtained indicated(More)