Neural Tube Defects - Power Point

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Neural Tube Defects : 

Neural Tube Defects Group 10 Jennifer Kim, Tatiana Backiev, Theresa Geraghty, Latasha Guy, Sharon Joseph, & Haroon Vohra

Normal formation of a neural tube : 

Normal formation of a neural tube 18th Day  Development of neural plate 24th Day  Upper portion closes 26th Day  Lower portion closes http://www.mun.ca/biology/desmid/brian/BIOL3530/DB_Ch11/fig11_9.jpg

What is a neural tube defect? : 

What is a neural tube defect? Malformation of the embryo’s central nervous system Anencephaly: Cephalic (head) end of neural tube fails to close and results in an absence of major portion of brain, skull, and scalp. Spina Bifida: Exposure of spinal and nerves. Most common birth defect in U.S. (1:1000 pregnancies)

Who is at risk? : 

Who is at risk? Women of childbearing age Previous pregnancy with a NTD or having a relative with such a defect Maternal medical conditions such as diabetes, obesity, and epilepsy

Prevention : 

Prevention Folic acid importance (1964) Daily recommended dose from United States Public Health Service of folic acid (Vitamin B9): 400-800 mcg/day Fortified Diet: Bread, pasta, rice, cereals. Multivitamin Natural Diet: liver, orange juice, green leafy vegetables, legumes, etc http://blog.lib.umn.edu/ster0171/socks/broccoli.jpg

Signs & Symptoms : 

Signs & Symptoms No physical signs and symptoms during pregnancy Spina Bifida and Anencephaly aforementioned Tests to detect: Maternal Blood Test (MSAFP: Maternal Serum Alpha Fetoprotein) Amniocentesis Ultrasound of fetal spine

Treatment : 

Treatment Anencephaly: No Treatment Available, Usually Death Spina Bifida: Surgery used to close opening on back Shunt surgically installed to drain out CSF Spina Bifida Occulta: No treatment needed

Folic Acid Metabolism : 

Folic Acid Metabolism Biochemical function of folates are to act as coenzymes in single carbon transfer reactions. Folate is involved in many different metabolic pathways that are all interrelated. Thus a block in one pathway, disrupts all others For this reason, there is NO conclusive evidence yet as to the definite mechanism to answer question: why does taking folic acid prevent NTDs?

Pathways of Folate : 

Pathways of Folate http://www3.interscience.wiley.com.bluestem.csu.edu:2048/cgi-bin/fulltext/64000444/PDFSTART?CRETRY=1&SRETRY=0

Folate Derivatives : 

Folate Derivatives Folic Acid  DHF  THF  THF.C1 C1: Various active forms of THF involved in specific reactions Methyl-THF: Methionine Synthesis Methylene-THF: Thymidine Monophosphate Synthesis Formyl-THF: Purine Biosynthesis Formimino-THF: Interconversion intermediate Methenyl-THF: Interconversion Intermediate

Folate in Thymidalte Cycle : 

Folate in Thymidalte Cycle dTMP dUMP Dihydrofolate reductase 5,10 Methylene-THF Thymidylate synthase THF DHF Serine hydroxymethyltransferase

The Activated Methyl Cycle : 

The Activated Methyl Cycle

5,10 MTHFR(Methylenetetrahydrofolate Reductase) : 

5,10 MTHFR(Methylenetetrahydrofolate Reductase) Form of tetrahydrofolate located in the cytoplasm of cells that is an intermediate in metabolism   MTHFR, coenzyme that accepts and donates methenyl (CH) groups   Important in homocysteine metabolism Irreversibly reduces 5,10 methylenetetrahydrofolate (substrate) to 5-methyltetrahydrofolate (product) MTHFR converts 5,10 methylene-THF to 5-Methyl THF directing it to methylation of homocysteine synthesis

Methionine Synthase : 

Methionine Synthase Enzyme- catalyzes the reaction between: N5-methyltetrahydrofolate + l-homocysteine To form = Deficiency in this enzyme leads to an accumulation of : and neurological abnormalities including NTDs. Homocysteine can be converted to methionine by various B-vitamins e.g. Folic Acid. Not enough folic acid in the diet= elevated amounts of Homocysteine=greater possibility of Neural Tube Defects.

MORE FOLIC ACID FOR ALL WOMEN!!! : 

MORE FOLIC ACID FOR ALL WOMEN!!!

To Find More Information: : 

To Find More Information: http://www.cdc.gov/ncbddd/folicacid/index.html http://dietary-supplements.info.nih.gov/factsheets/folate.asp http://www.fda.gov/AboutFDA/WhatWeDo/History/ProductRegulation/SelectionsFromFDLIUpdateSeriesonFDAHistory/ucm091883.htm