Biomedical subjects

R Andreoli

Publications and source records attributed to R Andreoli.

25 records · Page 2Linked to original sources

PubMedDate not supplied

[Urinary excretion of 4-vinyl phenol after experimental and occupational exposure to styrene].

Aim of this study was to assess the importance and the role of a minor metabolic route of styrene metabolism, involving the oxidation of the arene moiety of styrene, by means of the characterization of the conjugated urinary metabolites of 4-vinylphenol (4-VP). 4-vinylphenol-glucuronide (4-VP-G) and -sulfate (4-VP-S) were measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) from 174 workers belonging to three cohorts recruited in European countries, and from 26 volunteers exposed to 50 mg/m3 (11.8 ppm) of styrene for 8 h. The 4-VP conjugates represented about 0.5-1% of the total excretion of styrene metabolites. Both 4-VP-G and 4-VP-S are eliminated with a mono-phasic kinetic, the glucuronide being excreted faster (half-time, 2.2 +/- 0.2 h) than the sulfate (half-time 9.7 +/- 1.7 h). The urinary 4-VP was found to be significantly correlated both with airborne styrene (r = 0.607, p < 0.001) and the sum of MA and PGA (r = 0.903, p < 0.001 in 'end-of-shift' samples). A measurable background excretion of 4-VP was also found in all urine samples from controls not occupationally exposed to styrene. This background appears to be highly correlated to smoking (p < 0.001). Consequently, the use of 4-VP as a biomarker of styrene exposure is recommended for exposures exceeding 1 ppm.

Adult↗

PubMedDate not supplied

[Genetic polymorphism of biotransforming enzymes and genotoxic effects of styrenes].

A cross-sectional study was carried out on laminators producing glass-fibre reinforced plastics, to evaluate the role of genetic polymorphism of xenobiotic metabolising enzymes on the genotoxicity of styrene. Clastogenic effects, evaluated by the micronucleus test, are related with end-of-shift urinary concentration of 4-vinylphenol and seem to be modulated by NQO1 polymorphism; aneuploidogenic effects, evaluated by the identification of centromers in micronuclei using the fluorescence in situ hybridisation technique with a pancentromeric probe, are related with before-shift urinary levels of mandelic and phenylglyoxylic acids and seem to be modulated by the GSTM1 polymorphism.

Adult↗

PubMedDate not supplied

[Indicators of pulmonary epithelial damage among workers at a foundry exposed to airborne pollutants].

Foundry ambient air contains very high concentrations of noxious substances, such as particulate matter and gaseous pollutants, which can target the respiratory epithelium. Serum concentrations of the 16-kDa Clara cell protein (CC16-S) may reflect both the integrity of the epithelial barrier and smoke-induced Clara cell toxicity. To evaluate whether CC16-S is a sensitive biomarker of early respiratory disturbances, it was determined in a group of 35 foundry male workers (aged 41.1 +/- 6.9 years) examined both prior to and at the end of their work-shift (06:00 a.m.-02:00 p.m.). Exposure to inhalable/respirable dusts and PAH was characterized; urinary excretion of 1-hydroxypyrene (1-OH-P) and naphtol was measured to assess exposure to pyrene and naphthalene, respectively. CC16 serum levels decreased at the end of the shift (10.7 +/- 3.82 micrograms/L vs. 8.39 +/- 3.05 micrograms/L; p < 0.01); such decrements were significantly larger in more exposed workers. Although smokers had lower baseline values as compared to non smokers, both subgroups showed an average decrease of 30% in CC16-S concentrations at the end of shift. CC16-S was also negatively correlated with 1-OH-P, but not with naphtol concentrations. Decreased CC16-S levels can result from citotoxicity and would represent an useful biomarker of pneumotoxicity in foundry workers exposed to complex mixtures.

Air Pollution, Indoor↗

PubMedDate not supplied

[New biomarkers of exposure].

In this paper we have defined the new biomarkers of exposure (NBE) as those biomarkers discovered in the last five years and, among previously validated biomarkers, also those applied in different ranges of doses or those determined in biological matrices which differ from matrices originally considered. We examined the results from the surveys carried out by the main Italian research units involved in biological monitoring, i.e. those from the Universities of Brescia, Milan, Naples, Padua, Parma, Pavia, Turin and Verona. The data were collected using a standardized model and included the following: type of element or organic compound, type of biomarker, analytical technique and method, their relationship with environmental monitoring data, their relationship with effect indicators or effects in general, improvement with respect to old biomarkers, reference values. Twenty two NBEs were identified: 14 elements and chemical compounds as such or as metabolites, 4 examples of mixtures, 3 of new matrices, one of speciation. Among the others, aspects such as interest in requiring NBE, quality assurance, availability, cost-benefit ratio were discussed. We conclude that development of this specific field of research appears to be a crucial point for future improvement in risk assessment and health surveillance procedures.

Animals↗

PubMedDate not supplied

[Neuroendocrine and renal effects of inorganic lead].

In this study 371 workers occupationally exposed to inorganic Pb (range of blood lead concentrations, PbB: 100-800 microg/l) were examined in order to assess neuroendocrine and renal effects, with regard to exposure levels and ALAD polymorphism. Plasma prolactin, urinary excretion of plasmaproteins and renal tissue constituents were measured. None of such markers differed significantly between workers stratified according to PbB levels, except for heat-stable isoenzyme NAG-B: its very low prevalence of values above the upper reference limit increased significantly with increasing PbB. No significant differences were found in indicators by ALAD genotype. Our findings did not provide evidence of any renal and neuroendocrine effects in workers exposed to the current lead levels.

Adult↗

PubMedDate not supplied

[Chronobiological evaluation of effects biomarkers and sampling].

Occupational exposure to oxidants is often associated with an increase in the levels of oxidative DNA damage in urine. Besides 8-hydroxy-2'-deoxyguanosine (8-oxo-dG), other products of position-8 guanine oxidation have been identified in urine, including 8-hydroxy-guanine (8-oxo-G) and 8-hydroxyguanosine (8-oxy-Guo). The aim of the present study was the characterization of these effect biomarkers in terms of inter- and intra-individuals varaibility, as well as in terms of their excretion profile during a 24 h-period. Urine samples were collected from 11 volunteers (6 samples/day). Urine concentrations of 8-oxo-G, 8-oxo-Guo, and 8-oxo-dG were determined by liquid chromatography-tandem mass spectrometry. The inter-individual variability, expressed as variation coefficient, was 85-150% for 8-oxo-G, 20-45% for 8-oxo-Guo, and 30-45% for 8-oxo-dG. The statistical anaysis for repeated measurements showed that none of the biomarkers was affected by significant variation during the day (one-way ANOVA, p < 0.05), thus excluding the existence of a circadian rhythm. We conclude that the sampling time is not critical for the assessment of oxidative DNA damage in urine.

Adult↗

PubMedDate not supplied

[Heme oxygenase 1 expression in foundry workers].

Heme oxygenase 1 (HO-1) catalyses the oxidation of heme to biliverdin, and its expression is induced by oxidative stress. This study was aimed at assessing the role of metabolic polymorphisms (CYP1A1, CYP1B1, GSTM1, GSTP1, EPHX) in the modulation of HO-1 gene expression in 37 foundry workers. Blood and urine samples were obtained at the beginning (BS) and at the end (ES) of work shift, in February (T1) and June (T2). Urinary 1-hydroxypyrene (1-OHP) was measured as a tracer of PAH exposure. HO-1 gene expression in ES samples normalized to BS values (HO-1 ES/BS) was higher at T2 respect to T1. HO-1 gene induction was related to ES 1-OHP when considering either T2 samples or the combination of the two samplings. HO-1 ES/BS was significantly increased in subjects with at least a mutant allele for GSTP1 as compared to subjects with GSTP1AA genotype (1.23 +/- 0.002 vs 0.88 +/- 0.002, p < 0.05). Only in subjects with at least one vari.nt allele for GSTP1, a positive correlation between HO-1 ET/IT expression and 1-OHP FT levels was observed (r2 = 0.21, p = 0.016). The present study demonstrates a correlation between PAH exposure, as assessed by urinary 1-OHP, and the induction of HO-1 expression. Such a correlation seems to be limited to subjects bearing variant alleles for GSTP1. At the same exposure levels, these subjects showed a greater expression of HO-1 FT as compared to subjects with GSTP1 wild type genotype, possibly due to a higher oxidative stress in the subjects expressing the mutant GSTP1-1 isoform, which could imply a limited scavenging capacity.

Adult↗