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Papers by Laetiscia Lavoie

Research paper thumbnail of Hexachloronorbornene-based flame retardants in humans: Levels in maternal serum and milk

Environment International, 2014

Five hexachloronorbornene-based flame retardants, Dechlorane Plus (DP), Dechlorane 602 (Dec 602),... more Five hexachloronorbornene-based flame retardants, Dechlorane Plus (DP), Dechlorane 602 (Dec 602), Dechlorane 603 (Dec 603), Dechlorane 604 (Dec 604) and hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), were measured in human milk and maternal serum. Dec 602, Dec 603 and HCDBCO were detected in both sample matrices with detection frequencies over 60%. Dec 604 was not detected in serum and only detected in 4.8% of milk samples. DP was present in over 77-87% of serum and 40-50% of milk samples. DP levels found in this study were lower than those reported in two Chinese studies. The ratio of the two DP isomers found in human samples (f(anti-DP) = 0.8) remained similar to the ratio reported in the DP technical mixture. Levels of Dec 602 and Dec 603 in serum were correlated. Levels of Dec 602 and HCBDCO were also correlated in serum samples as well as in milk samples. These biomonitoring results have provided baseline information about the presence of these flame retardants in nursing women in Canada, which can be used for estimating human exposure to these chemicals.

Research paper thumbnail of Maternal and Cord-Blood Thyroid Hormone Levels and Exposure to Polybrominated Diphenyl Ethers and Polychlorinated Biphenyls During Early Pregnancy

American Journal of Epidemiology, 2013

Thyroid hormones play a critical role in the growth of many organs, especially the brain. Polybro... more Thyroid hormones play a critical role in the growth of many organs, especially the brain. Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) interact with the thyroid pathway and may disturb neurodevelopment. This prospective study was designed to examine associations between maternal blood PBDEs and PCBs in early pregnancy and levels of thyroid hormones in maternal and umbilical-cord blood. Levels of low-brominated PBDEs, 3 PCB congeners, total and free thyroid hormones (triiodothyronine (T3) and thyroxine (T4)), thyroid-stimulating hormone, thyroid peroxidase antibodies, iodine, selenium, and mercury were measured in 380 pregnant women in the first trimester who were recruited at the University Hospital Center of Sherbrooke (Quebec, Canada) between September 2007 and December 2008. Thyroid hormone levels were also assessed at delivery and in cord blood (n = 260). Data were analyzed on both a volume basis and a lipid basis. At less than 20 weeks of pregnancy, no relationship was statistically significant in volume-based analysis. In lipid-based models, an inverse association between maternal PBDEs and total T3 and total T4 and a direct association with free T3 and free T4 were observed. At delivery, in both analyses, we observed negative associations between maternal total T4, free T3, cord-blood free T4, and PBDEs and between maternal free T3 and PCBs. Our results suggest that exposure to PBDEs and PCBs in pregnancy may interfere with thyroid hormone levels.

Research paper thumbnail of Abdelouahab et al. Respond to "Maternal PBDEs and Thyroid Hormones

American Journal of Epidemiology, 2013

Research paper thumbnail of Procedural Pediatric Sedation by Nurses: Available, Competent, and Safe

International Journal of Pediatrics, 2012

Sedation and/or analgesia are standard of care for pediatric patients during painful intervention... more Sedation and/or analgesia are standard of care for pediatric patients during painful intervention or medical imaging requiring immobility. Physician availability is frequently insufficient to allow for all procedural sedation. A nurse-led sedation program was created at the Centre Hospitalier Universitaire de Sherbrooke (CHUS) to address this problem.Objective. To evaluate the effectiveness and the safety of our program.Methods. A retrospective study of all the procedural sedations done over one year was performed. Complications were separated in four categories: (1) major complications (call for help; unexpected admission, aspiration, and code); (2) reportable sedation events (oxygen saturation <90%, bradycardia (more than 2 SD below normal for the age of the child), and hypotension (more than 2 SD below normal for the age of the child); (3) difficult sedation (agitation, inadequate sedation, and failure to perform the procedure), (4) minor complications.Results. 448 patients, 2...

Research paper thumbnail of Hexachloronorbornene-based flame retardants in humans: Levels in maternal serum and milk

Environment International, 2014

Five hexachloronorbornene-based flame retardants, Dechlorane Plus (DP), Dechlorane 602 (Dec 602),... more Five hexachloronorbornene-based flame retardants, Dechlorane Plus (DP), Dechlorane 602 (Dec 602), Dechlorane 603 (Dec 603), Dechlorane 604 (Dec 604) and hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), were measured in human milk and maternal serum. Dec 602, Dec 603 and HCDBCO were detected in both sample matrices with detection frequencies over 60%. Dec 604 was not detected in serum and only detected in 4.8% of milk samples. DP was present in over 77-87% of serum and 40-50% of milk samples. DP levels found in this study were lower than those reported in two Chinese studies. The ratio of the two DP isomers found in human samples (f(anti-DP) = 0.8) remained similar to the ratio reported in the DP technical mixture. Levels of Dec 602 and Dec 603 in serum were correlated. Levels of Dec 602 and HCBDCO were also correlated in serum samples as well as in milk samples. These biomonitoring results have provided baseline information about the presence of these flame retardants in nursing women in Canada, which can be used for estimating human exposure to these chemicals.

Research paper thumbnail of Maternal and Cord-Blood Thyroid Hormone Levels and Exposure to Polybrominated Diphenyl Ethers and Polychlorinated Biphenyls During Early Pregnancy

American Journal of Epidemiology, 2013

Thyroid hormones play a critical role in the growth of many organs, especially the brain. Polybro... more Thyroid hormones play a critical role in the growth of many organs, especially the brain. Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) interact with the thyroid pathway and may disturb neurodevelopment. This prospective study was designed to examine associations between maternal blood PBDEs and PCBs in early pregnancy and levels of thyroid hormones in maternal and umbilical-cord blood. Levels of low-brominated PBDEs, 3 PCB congeners, total and free thyroid hormones (triiodothyronine (T3) and thyroxine (T4)), thyroid-stimulating hormone, thyroid peroxidase antibodies, iodine, selenium, and mercury were measured in 380 pregnant women in the first trimester who were recruited at the University Hospital Center of Sherbrooke (Quebec, Canada) between September 2007 and December 2008. Thyroid hormone levels were also assessed at delivery and in cord blood (n = 260). Data were analyzed on both a volume basis and a lipid basis. At less than 20 weeks of pregnancy, no relationship was statistically significant in volume-based analysis. In lipid-based models, an inverse association between maternal PBDEs and total T3 and total T4 and a direct association with free T3 and free T4 were observed. At delivery, in both analyses, we observed negative associations between maternal total T4, free T3, cord-blood free T4, and PBDEs and between maternal free T3 and PCBs. Our results suggest that exposure to PBDEs and PCBs in pregnancy may interfere with thyroid hormone levels.

Research paper thumbnail of Abdelouahab et al. Respond to "Maternal PBDEs and Thyroid Hormones

American Journal of Epidemiology, 2013

Research paper thumbnail of Procedural Pediatric Sedation by Nurses: Available, Competent, and Safe

International Journal of Pediatrics, 2012

Sedation and/or analgesia are standard of care for pediatric patients during painful intervention... more Sedation and/or analgesia are standard of care for pediatric patients during painful intervention or medical imaging requiring immobility. Physician availability is frequently insufficient to allow for all procedural sedation. A nurse-led sedation program was created at the Centre Hospitalier Universitaire de Sherbrooke (CHUS) to address this problem.Objective. To evaluate the effectiveness and the safety of our program.Methods. A retrospective study of all the procedural sedations done over one year was performed. Complications were separated in four categories: (1) major complications (call for help; unexpected admission, aspiration, and code); (2) reportable sedation events (oxygen saturation <90%, bradycardia (more than 2 SD below normal for the age of the child), and hypotension (more than 2 SD below normal for the age of the child); (3) difficult sedation (agitation, inadequate sedation, and failure to perform the procedure), (4) minor complications.Results. 448 patients, 2...