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Vitamin A deficiency: A Permanent Cure Vitamin A deficiency: A Permanent Cure By Emory Sabatini Photo from: http://commons.wikimedia.org/wiki/File:Carrots_without_stems.JPG
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Vitamin A Essential nutrient for animal life Good for immune system and overall vision Found preformed in fruits and vegetables, or in beta-carotene form in orange organics Created w/in the body when… 2 retinal (vitamin A) molecules
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Vitamin A deficiency Happens when not enough vitamin A or Beta-carotene is obtained through diet, so not enough vitamin is found/produced in the body Symptoms include: Night blindness Xerophthalmia Keratomalacia Permanent blindness Death Xerophthalmia – one’s inability to produce tears due to vitamin A deificiency (seen internationally) Photo from: http://en.wikipedia.org/wiki/Subconjunctival_hemorrhage
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Deficiency statistics Is the most common and most deadly (if left untreated) vitamin deficiency in the world Approx. 250k – 500k children go blind from the deficiency, half of whom die w/in the next year Most common in Southeast Asia and Africa Photo from: http://en.wikipedia.org/wiki/Vitamin_A_deficiency A photo of where the deficiency is most common in the world
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Current treatments Vitamin supplementation – through vitamin A pills or food fortification (adding of nutrients to foods) to force the body to absorb the vitamin Dietary changes – eating foods high in Vitamin A or beta-carotene The only problem… Prenatal vitamins, which are high in Vitamin A None of these solutions are permanent or work in a long term setting! Photo from: http://en.wikipedia.org/wiki/Prenatal_vitamins
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New treatment design Genetically engineered E. coli (bacteria found in the intestine of humans) to consistently produce beta- carotene The genes that control the enzymes produced in the several pathways involved in the production of beta – carotene would be inserted into the E. coli The BCMO1enzyme is produced in the small intestine, so the E. coli would be placed there via oral medication Bacteria would thrive in the gut and would nourish the host for much longer than vitamin supplementation pills/foods
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Biosynthesis Pathways Glycolysis – the production of Glyceraldehyde 3- phosphate and pyruvic acid from glucose, which are the starting points in the MEP/DOXP pathway MEP/DOXP – takes G3P and pyruvic acid and produces isopentenyl pyrophosphate and dimethylallyl pyrophosphate Mevalonate – DMAPP -> geranylgeranyl pyrophosphate Phytoene Synthase – GGPP -> phytoene -> beta- carotene
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Glycolysis Pathway MEP/DOXP Pathway Mevalonate Pathway Phytoene Synthase BETA-CAROTENE!!
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Sensors Vitamin A sensors and beta-carotene sensors would be present in the bacteria to avoid overdose of either substance
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Advantages This is permanent – the host will probably never have to worry about Vitamin A deficiency for the rest of his/her life Most likely… The host will only have to use this treatment once in their lifetime – a bottle of these pills could supply several families for the rest of their lives Most likely…
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But… While I said this could be permanent and would only have to be taken once… I don’t know! The bacteria may not live forever in the gut, but they will thrive longer than vitamin supplementation will keep someone alive Because of this, the treatment may have to be used periodically in some people
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Potential problems Overdose – while the sensors on the bacteria should be able to control this, overdose is still possible as there is no way to control production while Vitamin A and beta-carotene are not present Infection – E. coli are harmless in most situations. But, the bacteria should still be prone to antibiotics in case something goes wrong Photo from: http://en.wikipedia.org/wiki/Escherichia_coli E. Coli live in the guts of humans, and do not appear to cause harm in a normal situation. But, they have been seen to cause food poisoning in some host bodies.
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Testing Two groups of rats would be tested in a pre- clinical trial It takes rats approx. 60 days to show signs of vitamin A deficiency. Signs are often seen shortly after deficiency administration is stopped Symptoms: Xerophthalmia Growth impairment Photo from: http://en.wikipedia.org/wiki/Rat
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Testing – Group 1 First group: Seeing if treatment design works at all EG: Rats w/ induced deficiency given treatment design w/ Vitamin A deficient diet CG: Rats w/ induced deficiency given no treatment w/ Vitamin A deficient diet SOCG: Rats w/ induced deficiency given vitamin A supplementation w/ Vitamin A deficient diet ECG: Rats w/ induced deficiency given normal E. coli bacteria w/ Vitamin A deficient diet PG: Rats w/ induced deficiency given deactivated E. coli w/ Vitamin A deficient diet
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Testing – Group 2 Second group: Seeing if sensors can control Vitamin A levels in the body EG: Rats w/ induced deficiency given treatment and kept on normal diet CG: Rats w/ induced deficiency given no treatment and kept on normal diet SOCG: Rats w/ induced deficiency given vitamin A supplementation and kept on normal diet ECG: Rats w/ induced deficiency given normal E. coli bacteria and kept on normal diet PG: Rats w/ induced deficiency given deactivated E. coli and kept on normal diet
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Testing – Moving on After the rats have been tested in the different components of the treatment, and the bacteria have been modified to manage problems that arose during testing, the pre-clinical trial would move on to larger animals, and eventually a clinical trial would test humans. W/ the humans, instead of inducing Vitamin A deficiency, the trial would be conducted in Asia and Africa where the condition is common With human patients, the trial would have to be closely monitored with government and Internal Review Board approval/oversight
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The Future If the treatment were to be successful, thousands of lives could be saved each year by a simple medication This treatment could also pave the way for treatments to other deficiency-related conditions, such as vitamin B, C, D, E, and K deficiency Photo from: http://en.wikipedia.org/wiki/Rickets Rickets is a disorder of the bones caused by Vitamin D, calcium or phosphorus deficiency
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Thank you!!!!!
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