Talk:Abnormal Development - Heavy Metals: Difference between revisions

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==For chemical page - formaldehyde==
Embryo toxicity and teratogenicity of formaldehyde.
Embryo toxicity and teratogenicity of formaldehyde.
Thrasher JD, Kilburn KH.
Thrasher JD, Kilburn KH.
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"C-14 formaldehyde crosses the placenta and enters fetal tissues. The incorporated radioactivity is higher in fetal organs (i.e., brain and liver) than in maternal tissues. The incorporation mechanism has not been studied fully, but formaldehyde enters the single-carbon cycle and is incorporated as a methyl group into nucleic acids and proteins. Also, formaldehyde reacts chemically with organic compounds (e.g., deoxyribonucleic acid, nucleosides, nucleotides, proteins, amino acids) by addition and condensation reactions, thus forming adducts and deoxyribonucleic acid-protein crosslinks. "
"C-14 formaldehyde crosses the placenta and enters fetal tissues. The incorporated radioactivity is higher in fetal organs (i.e., brain and liver) than in maternal tissues. The incorporation mechanism has not been studied fully, but formaldehyde enters the single-carbon cycle and is incorporated as a methyl group into nucleic acids and proteins. Also, formaldehyde reacts chemically with organic compounds (e.g., deoxyribonucleic acid, nucleosides, nucleotides, proteins, amino acids) by addition and condensation reactions, thus forming adducts and deoxyribonucleic acid-protein crosslinks. "
==iron==
Am J Clin Nutr. 2003 Apr;77(4):924-30.
Maternal iron status influences iron transfer to the fetus during the third trimester of pregnancy.
O'Brien KO, Zavaleta N, Abrams SA, Caulfield LE.
Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205-2179, USA. kobrien@jhsph.edu
Abstract
BACKGROUND: The effect of maternal iron status on fetal iron deposition is uncertain. OBJECTIVE: We used a unique stable-isotope technique to assess iron transfer to the fetus in relation to maternal iron status. DESIGN: The study group comprised 41 Peruvian women. Of these women, 26 received daily prenatal supplements containing iron and folate (n = 11; Fe group) or iron, folate, and zinc (n = 15; Fe+Zn group) from week 10-24 of pregnancy to 1 mo postpartum. The remaining 15 women (control group) received iron supplementation only during the final month of pregnancy. During the third trimester of pregnancy (+/- SD: 32.9 +/- 1.4 wk gestation) oral 57Fe (10 mg) and intravenous 58Fe (0.6 mg) stable iron isotopes were administered to the women, and isotope enrichment and iron-status indicators were measured in cord blood at delivery. RESULTS: The net amount of 57Fe in the neonates' circulation (from maternal oral dosing) was significantly related to maternal iron absorption (P < 0.005) and inversely related to maternal iron status during the third trimester of pregnancy: serum ferritin (P < 0.0001), serum folate (P < 0.005), and serum transferrin receptors (P < 0.02). Significantly more 57Fe was transferred to the neonates in non-iron-supplemented women: 0.112 +/- 0.031 compared with 0.078 +/- 0.042 mg in the control group (n = 15) and the Fe and Fe+Zn groups (n = 24), respectively (P < 0.01). In contrast, 58Fe tracer in the neonates' circulation was not significantly related to maternal iron status. CONCLUSION: The transfer of dietary iron to the fetus is regulated in response to maternal iron status at the level of the gut.
PMID: 12663293

Revision as of 08:05, 31 July 2010

For chemical page - formaldehyde

Embryo toxicity and teratogenicity of formaldehyde. Thrasher JD, Kilburn KH. Arch Environ Health. 2001 Jul-Aug;56(4):300-11. Review. PMID: 11572272

"C-14 formaldehyde crosses the placenta and enters fetal tissues. The incorporated radioactivity is higher in fetal organs (i.e., brain and liver) than in maternal tissues. The incorporation mechanism has not been studied fully, but formaldehyde enters the single-carbon cycle and is incorporated as a methyl group into nucleic acids and proteins. Also, formaldehyde reacts chemically with organic compounds (e.g., deoxyribonucleic acid, nucleosides, nucleotides, proteins, amino acids) by addition and condensation reactions, thus forming adducts and deoxyribonucleic acid-protein crosslinks. "

iron

Am J Clin Nutr. 2003 Apr;77(4):924-30. Maternal iron status influences iron transfer to the fetus during the third trimester of pregnancy. O'Brien KO, Zavaleta N, Abrams SA, Caulfield LE.

Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205-2179, USA. kobrien@jhsph.edu Abstract BACKGROUND: The effect of maternal iron status on fetal iron deposition is uncertain. OBJECTIVE: We used a unique stable-isotope technique to assess iron transfer to the fetus in relation to maternal iron status. DESIGN: The study group comprised 41 Peruvian women. Of these women, 26 received daily prenatal supplements containing iron and folate (n = 11; Fe group) or iron, folate, and zinc (n = 15; Fe+Zn group) from week 10-24 of pregnancy to 1 mo postpartum. The remaining 15 women (control group) received iron supplementation only during the final month of pregnancy. During the third trimester of pregnancy (+/- SD: 32.9 +/- 1.4 wk gestation) oral 57Fe (10 mg) and intravenous 58Fe (0.6 mg) stable iron isotopes were administered to the women, and isotope enrichment and iron-status indicators were measured in cord blood at delivery. RESULTS: The net amount of 57Fe in the neonates' circulation (from maternal oral dosing) was significantly related to maternal iron absorption (P < 0.005) and inversely related to maternal iron status during the third trimester of pregnancy: serum ferritin (P < 0.0001), serum folate (P < 0.005), and serum transferrin receptors (P < 0.02). Significantly more 57Fe was transferred to the neonates in non-iron-supplemented women: 0.112 +/- 0.031 compared with 0.078 +/- 0.042 mg in the control group (n = 15) and the Fe and Fe+Zn groups (n = 24), respectively (P < 0.01). In contrast, 58Fe tracer in the neonates' circulation was not significantly related to maternal iron status. CONCLUSION: The transfer of dietary iron to the fetus is regulated in response to maternal iron status at the level of the gut.

PMID: 12663293