1,721,017 research outputs found
Biomonitoring of human exposure to methyl bromide by isotope dilution mass spectrometry of peptide adducts
No full textA procedure for the determination of haemoglobin adducts formed by exposure to methyl bromide was evaluated as a possible method for the measurement of a biological index of exposure to the alkylating agent. The reaction products after in vitro incubation were used to design the chemical syntheses of deuterated peptides corresponding to the tryptic peptides where the modified residues had been identified. These peptides were used as standards for the quantitative evaluation of real samples, The correlation coefficient was r = 0.998 in the range 2.5-20 ppm. The relative standard deviation was about 3%, Blood samples were digested with trypsin and the mixture was analysed by liquid chromatography/electrospray mass spectrometry through selected ion monitoring of the mass signal relative to the modified peptides;, The analysis of blood samples from workers exposed to methyl bromide demonstrated the usefulness of this mass spectrometric-based method fur the monitoring of human exposure to the genotoxic alkylating agent via the synthesis of suitable peptide standards. This procedure is the first alternative method to the wed established monitoring of N-terminal adducts, the latter not being applicable to all alkylating agent
Fumigazione di terreni agricoli e derrate alimentari: la valutazione dell’esposizione professionale a bromuro di metile
No full textProteomic approach for the analysis of acrylamide-hemoglobin adducts Perspectives for biological monitoring
No full textThe formation of adducts between acrylamide and hemoglobin in vitro was investigated by using mass spectrometric methodologies to identify the amino acid residues sensitive to alkylation. Liquid chromatography-electrospray ionisation mass spectrometry analysis of either intact or trypsin-digested alpha- and beta-globin chains isolated from hemolysate samples incubated in vitro with acrylamide at different molecular ratios allowed us to identify Cys93 of beta-globin as the most reactive site in hemoglobin, according to a Michael-type addition reaction between acrylamide and the sulphydryl group of cysteine. The only other reactive sites were Cys 104 of alpha-globin and the N-terminal amino groups of both chains. The method developed, based on electrospray ionisation quadrupole time-of-flight tandem mass spectrometry analysis of intact globin chains was able to specifically detect low levels of adducts. In this way, rapid identification of alkylated portion of Hb was achieved to be potentially used as a biomarker for high-sensitivity biological monitorin
Determinazione di Benzene e Acido S-fenil mercapturico urinari nella valutazione dell’esposizione professionale a Benzene
No full textMASS-SPECTROMETRIC ANALYSIS OF RAT HEMOGLOBIN BY FAB-OVERLAPPING - PRIMARY STRUCTURE OF THE ALPHA-MAJOR AND OF 4 BETA-CONSTITUTIVE CHAINS
No full text1. The globin chain components of Sprague-Dawley rat hemoglobin were obtained by reverse-phase HPLC which showed the presence of two alpha-chain and four beta-chains. 2. The accurate molecular weight of each globin chain was determined by means of electrospray mass spectrometry. Extensive mass spectrometric analysis on several enzymatic digests by fast atom bombardment mass spectrometry (FAB-overlapping) meant to determine the complete sequence of the alpha-major and of the four beta-globins. 3. The primary structure of the alpha-major globin was found in agreement with literature data (Garrick et al., 1975 Biochem. J. 149, 245-258; Chua el al., 1987). 4. Sequence analysis of the four beta-globin chains showed that amino acid differences are restricted to two protein portions: the region 22-25 and 123-125, the remaining portions of the molecule being unchanged in the four globins. Furthermore, all the amino acid replacements correspond to single point DNA mutations and (with the exception of the substitution Asp 22 --> Asn in the beta(2)-globin) involve uncharged substitutions
Determinazione di Benzene e Acido S-fenil mercapturico urinari nella valutazione dell’esposizione professionale a Benzene
No full textSorveglianza sanitaria e valutazione del rischio in agricoltura : problemi emergenti e necessità di armonizzazione degli approcci
No full textAbout 1,7 millions of agricultural enterprises are present in Italy, with a total of about 2,500,000 workers, exposed, during their activities, to several risk factors, whose impact on workers’ health is still unclear. Reasonable doubts arise of a possible, significant underestimate of the cases of occupational diseases reported in the sector, in a general picture suggesting that muscle skeletal disorders and hearing loss are the leading cause of morbility. A main cause of underreporting is the relatively small proportion (45-60%) of agricultural workers provided with health surveillance at the workplace, and the fact that no more than 60% of the agricultural enterprises have done an acceptable risk assessment. Improving risk assessment and increasing health occupational surveillance are major objectives for the sector, which probably needs to be addressed by a specific legislation, different from the existing one, mainly addressed at industry. Risk assessment needs to be improved with the creation of specific tools, adequate to provide sound risk estimates avoiding the need of measuring risk factors in any enterprises. Finally, health surveillance must undergo a specific harmonization process, mainly achievable with guidelines, and must be based on structures adequate to reach agricultural workers directly at their workplaces. The problem of self employed workers and family enterprises must be considered, in order to avoid inequalities among workers in the access to prevention
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