title: Cholinesterase activities determination in frozen blood samples: an improvement to the occupational monitoring in developing countries.
abstract: 1. Studies were carried out on rural workers in Brazil to determine the decrease in the activity of plasma butyrylcholinesterase (BChE), erythrocyte cholinesterase (AChE) associated with exposure to organophosphorus pesticides (OP). The goal of this work is to help prevent injury to these workers. 2. In developing countries the distance between area of pesticide use and reference laboratories is a drawback for analytical techniques, since cholinesterase activity determinations require fresh blood samples. Field methodologies can be a useful alternative to laboratory tests, however they are not as sensitive as those found in laboratories. 3. The modification of Ellman's Method presented in this paper allows blood samples to be frozen and maintain enzymatic stability: 7 days for AChE and 3 days for BChE. The proposed method is also more sensitive than Ellman's Method Modified by Magnotti (EMMM). 4. The results suggest that the Ellman Method Modified by Oliveira-Silva (EMMOS) is valid for monitoring procedures. This method represents an important contribution to the process of monitoring OP exposures, since the evaluations no longer have to be conducted near the site of OP use.
authors.affiliation: Oswaldo Cruz Foundation National School of Public Health, Rio de Janeiro, Brazil.
authors.forename: J J
authors.initials: JJ
authors.lastname: Oliveira-Silva
authors.forename: S R
authors.initials: SR
authors.lastname: Alves
authors.forename: A F
authors.initials: AF
authors.lastname: Inacio
authors.forename: A
authors.initials: A
authors.lastname: Meyer
authors.forename: P N
authors.initials: PN
authors.lastname: Sarcinelli
authors.forename: R C
authors.initials: RC
authors.lastname: Mattos
authors.forename: M F
authors.initials: MF
authors.lastname: Ferreira
authors.forename: J C
authors.initials: JC
authors.lastname: Cunha
authors.forename: J C
authors.initials: JC
authors.lastname: Moreira
mesh_terms: D000110:Acetylcholinesterase / Q000097:blood*; D002091:Butyrylcholinesterase / Q000097:blood*; D015925:Cryopreservation; D004784:Environmental Monitoring / Q000379:methods*; D004795:Enzyme Stability; D004912:Erythrocytes / Q000187:drug effects / Q000201:enzymology*; D005615:Freezing; D006801:Humans; D016273:Occupational Exposure / Q000032:analysis*; D010261:Paraoxon / Q000031:analogs & derivatives* / Q000494:pharmacology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: C121104:ethylparaoxon; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase; D010261:Paraoxon