Biomedical subjects

Laura Gribaldo

Publications and source records attributed to Laura Gribaldo.

21 records · Page 2Linked to original sources

PubMed2002

In vitro tests for haematotoxicity: prediction of drug-induced myelosuppression by the CFU-GM assay.

In a prevalidation study, a standard operating procedure (SOP) for human and mouse in vitro tests was developed, for evaluating the potential haematotoxicity of xenobiotics in terms of their direct, adverse effects on the myeloid colony-forming unit (CFU-GM). Based on the adjustment of the mouse-derived maximum tolerated dose (MTD), a prediction model was set up to calculate the human MTD, and an international blind trial was designed to apply this model to the clinical neutropenia of 23 drugs including 17 antineoplastics. The model correctly predicted the human MTD for 20 drugs out of the 23 (87%). This high percentage of predictivity, and the reproducibility of the SOP testing, confirmed the scientific validation of this model, and suggest promising applications for developing and validating other in vitro methods for use in haematotoxicology.

Acute Disease↗

PubMed2002

Haematotoxicology: scientific basis and regulatory aspects.

Haematopoietic tissues are the targets of numerous xenobiotics. The purpose of in vitro haematotoxicology is the prediction of adverse haematological effects from toxicants on human haematopoietic targets under controlled experimental conditions in the laboratory. Building on its foundations in experimental haematology and the wealth of haematotoxicological data found in experimental oncology, this field of alternative toxicology has developed rapidly during the past decade. Preclinical and clinical drug development for anti-cancer drugs differs from that for other pharmaceuticals, because of the life-threatening nature of the disease. Treatment with anti-cancer drugs at clinically efficacious doses usually induces serious side-effects. The design of preclinical toxicology studies for anti-cancer drugs is intended to identify a safe clinical starting dose, characterise toxicities that could be encountered in human clinical trials, and determine whether these toxicities are reversible, manageable, and predictable. Although the myeloid colony-forming unit (CFU-GM) progenitor is most frequently evaluated, other defined progenitors and stem cells, as well as cell types found in the marrow stroma, can now be evaluated in vitro. Genetic damage to haematopoietic cells can occur in the absence of any overt haematological signs. The development of tissue-specific screening systems that are able to give information about the toxic effects of chemicals, drugs and environmental hazards on target genes is needed, in order to make preliminary decisions or to set priorities for selection among large groups of chemicals and possible drugs.

Animal Testing Alternatives↗

PubMedDate not supplied

Modulation of different stress pathways after styrene and styrene-7,8-oxide exposure in HepG2 cell line and normal human hepatocytes.

Styrene is one of the most important monomers produced worldwide. IARC classified styrene as a possible carcinogen to humans (group 2B). Styrene-7,8-oxide (SO) is the main reactive metabolite of styrene, and it is found to be genotoxic in several in vitro test systems. Styrene and styrene-7,8-oxide (SO) toxicity to HepG2 cells was investigated by evaluating end-points such as heat shock proteins (Hsps), metallothioneins (MT), apoptosis-related proteins, accumulation of styrene within the cells and expression of two isoforms of cytochrome P450. The potential activity of styrene and styrene-7,8-oxide in modulating gene expression was also investigated. The results showed induction of Hsp70, metallothioneins, BclX(S/L) and c-myc expression and a decrease in Bax expression in HepG2 after treatments, confirming that these compounds activated protective mechanisms. Moreover, up-regulation of TGFbeta2 and TGFbetaRIII in HepG2 cells was found after exposure to styrene, while in human primary hepatocytes these genes were down-regulated after both treatments. Finally, it was found that styrene and SO treatments did not induce CYP1A2 and CYP2E1 protein expression. In conclusion, both compounds caused toxic stress in HepG2 cells, with SO being more toxic; in the meantime, a different effect of the two compounds in HepG2 cells and primary human hepatocytes was observed regarding their activity in gene modulation.

Carcinogens↗