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Biomedical subjects

D Usiglio

Publications and source records attributed to D Usiglio.

6 recordsLinked to original sources
PubMed1996

Sensitization to para-tertiary-butylphenolformaldehyde resin.

BACKGROUND: Phenolformaldehyde resins, especially the para-tertiary-butylphenolformaldehyde resin (PTBP-FR), are widely used in industry and in numerous materials of everyday use, such as glues, adhesives, or inks. They can cause many occupational and nonoccupational cases of dermatitis. PATIENTS AND METHODS: Forty-one patients with positive patch test results to PTBP-FR were selected for this study. They were patch-tested with a series of chemically related compounds and cross-reactions were noted. RESULTS: Phenolformaldehyde resin (PF-R) was frequently positive (65.8%), whereas other compounds gave a much smaller number of positive results. Cases of occupational exposure (24.4%), location of the dermatitis (hands were involved in 46.3% of cases), and possible sources of exposure (shoes were the responsible agent in 12.2% of cases) were evaluated. CONCLUSIONS: Phenolformaldehyde resins are an important cause of contact dermatitis and must be studied chemically and clinically to improve the prognosis of sensitized patients.

Adolescent↗
PubMed1992

Comparative assessment of the cytotoxic effects of different xenobiotics in three hepatoma cell lines.

MH1C1, HTC and HEPA 1c1c7 hepatoma cell lines were selected in this study as the bioindicators of the cytotoxicity induced by six chemicals: butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), cycloheximide (CHE), cyclophosphamide (CPA), potassium dichromate (Cr VI) and 2,4-dinitrophenol (DNP). The concentrations used were in the range from 10(-6) mol/l to 10(-2) mol/l, and the exposure time was 24 h. Two end-points were measured to evaluate cytotoxicity: the detachment of dead cells from the monolayer (CS), as evaluated by detection of the total macromolecules present in the cell monolayers solubilized in alkali and the loss of colony-forming efficiency (CF). The dose-response curves were different from one compound to another, but generally similar with the two assays, the colony formation being the most sensitive test. Some technical problems like the toxicity of the solvents at the highest concentrations, the different sizes of colonies, the unspecific cellular detachment due to overgrowth during the experimental time, can be overcome by accurate standardization of the protocols used for each cell line. The sensitivity of the three cell lines was very similar, with some differences in the case of compounds exerting intermediate toxic effects, like CHE and DNP. The most toxic compound was Cr (VI), the least toxic one was CPA. The low cytotoxic effects displayed by CPA could be due to a lack of bioactivation and/or an increase of the inactivating enzymes, which are typical of hepatoma cell lines.

Animals↗