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Medical Forum / General / Laboratory / September 2004Iron accumulation in HIV-infected patients
<<snip>> iron accumulation found in these patients is caused by unknown mechanisms <<snip>> Biometals. 2004 Aug;17(4):443-50. Related Articles, Links Effects of AZT on cellular iron homeostasis. Bozzi A, Brisdelli F, D'Alessandro AM, D'Andrea G, Lizzi AR, Rinaldi AC, Oratore A. Department of Biomedical Sciences and Technologies, University of L'Aquila, Via Vetoio, Coppito 2, 67100 L'Aquila, Italy. bozzi@cc.univaq.it 3'-azido-3'-deoxythymidine (AZT), the first chemotherapeutic drug approved by FDA for treatment of HIV-infected patients and still used in combination therapy, has been shown to induce, upon prolonged exposure, severe bone marrow toxicity manifested as anemia, neutropenia and siderosis. These toxic effects are caused by inhibition of heme synthesis and, as a consequence, transferrin receptor (TfR) number appears increased and so iron taken up by cells. Since iron overload can promote the frequency and severity of many infections, siderosis is viewed as a further burden for AIDS patients. We have previously demonstrated that AZT-treated K562 cells showed an increase of the number of TfRs located on the surface of the plasma membrane without affecting their biosynthesis, but slowing down their endocytotic pathway. In spite of the higher number of receptors on the plasma-membrane of AZT-treated cells, intracellular accumulation of iron showed a similar level in control and in drug-exposed cells. The chelating ability of AZT and of its phosphorylated derivatives, both in an acellular system and in K562 cells, was also checked. The results demonstrated that AZT and AZTMP were uneffective as iron chelators, while AZTTP displayed a significant capacity to remove iron from transferrin (Tf). Our results suggest that AZT may be not directly involved in the iron overloading observed upon its prolonged use in AIDS therapy. The iron accumulation found in these patients is instead caused by other unknown mechanisms that need further studies to be clarified. PMID: 15259365 [PubMed - in process] -------------------------------------------------------------------------- ------ Who loves ya. Tom  SignatureJesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://pages.ivillage.com/ironjustice/manisaherbivore DEAD PEOPLE WALKING http://pages.ivillage.com/ironjustice/deadpeoplewalking Care to post a copy of the article that won you the Nobel Prize in Medicine? I 'll be happy to post your personal announcement that you were awarded one. But I can't find your name on any real articles. SignatureStev Lenon 91B20 '68-'69 When the dawn came up like thunder slenon@tampabay.rr.com http://web.tampabay.rr.com/stevglo/index.html/slhomepage92kword.htm >Subject: Re: Iron accumulation in HIV-infected patients <<snip>> iron accumulation found in these patients is caused by unknown mechanisms <<snip>> Biometals. 2004 Aug;17(4):443-50. Related Articles, Links Effects of AZT on cellular iron homeostasis. Bozzi A, Brisdelli F, D'Alessandro AM, D'Andrea G, Lizzi AR, Rinaldi AC, Oratore A. Department of Biomedical Sciences and Technologies, University of L'Aquila, Via Vetoio, Coppito 2, 67100 L'Aquila, Italy. bozzi@cc.univaq.it 3'-azido-3'-deoxythymidine (AZT), the first chemotherapeutic drug approved by FDA for treatment of HIV-infected patients and still used in combination therapy, has been shown to induce, upon prolonged exposure, severe bone marrow toxicity manifested as anemia, neutropenia and siderosis. These toxic effects are caused by inhibition of heme synthesis and, as a consequence, transferrin receptor (TfR) number appears increased and so iron taken up by cells. Since iron overload can promote the frequency and severity of many infections, siderosis is viewed as a further burden for AIDS patients. We have previously demonstrated that AZT-treated K562 cells showed an increase of the number of TfRs located on the surface of the plasma membrane without affecting their biosynthesis, but slowing down their endocytotic pathway. In spite of the higher number of receptors on the plasma-membrane of AZT-treated cells, intracellular accumulation of iron showed a similar level in control and in drug-exposed cells. The chelating ability of AZT and of its phosphorylated derivatives, both in an acellular system and in K562 cells, was also checked. The results demonstrated that AZT and AZTMP were uneffective as iron chelators, while AZTTP displayed a significant capacity to remove iron from transferrin (Tf). Our results suggest that AZT may be not directly involved in the iron overloading observed upon its prolonged use in AIDS therapy. The iron accumulation found in these patients is instead caused by other unknown mechanisms that need further studies to be clarified. PMID: 15259365 [PubMed - in process] -------------------------------------------------------------------------- ------ Who loves ya. Tom SignatureJesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://pages.ivillage.com/ironjustice/manisaherbivore DEAD PEOPLE WALKING http://pages.ivillage.com/ironjustice/deadpeoplewalking Anemia and iron deficiency: effects on pregnancy outcome Lindsay H Allen From the Department of Nutrition, University of California, Davis. This article reviews current knowledge of the effects of maternal anemia and iron deficiency on pregnancy outcome. A considerable amount of information remains to be learned about the benefits of maternal iron supplementation on the health and iron status of the mother and her child during pregnancy and postpartum. Current knowledge indicates that iron deficiency anemia in pregnancy is a risk factor for preterm delivery and subsequent low birth weight, and possibly for inferior neonatal health. Data are inadequate to determine the extent to which maternal anemia might contribute to maternal mortality. Even for women who enter pregnancy with reasonable iron stores, iron supplements improve iron status during pregnancy and for a considerable length of time postpartum, thus providing some protection against iron deficiency in the subsequent pregnancy. Mounting evidence indicates that maternal iron deficiency in pregnancy reduces fetal iron stores, perhaps well into the first year of life. This deserves further exploration because of the tendency of infants to develop iron deficiency anemia and because of the documented adverse consequences of this condition on infant development. The weight of evidence supports the advisability of routine iron supplementation during pregnancy. http://www.nutrition.org/cgi/content/abstract/130/11/2821?ijkey=89990f6a1ba50b60 6e19404403b7e4b5a969171e&keytype2=tf_ipsecsha SignatureMike Collins UK Mike&heather-at-oakwellmount-dot-freeserve-dot-co-dot-uk >Subject: Re: Iron accumulation in HIV-infected patients >From: "Mike Collins" mike&heather@acornwellmount.freeserve.co.uk [quoted text clipped - 25 lines] > >http://www.nutrition.org/cgi/content/abstract/130/11/2821?ijkey=89990f6a1ba50b60 6e19404403b7e4b5a969171e&keytype2=tf_ipsecsha Your article is quite .. old .. http://herbivore.7h.com/anemia.html 'They' have admitted .. "everything we thought about anemia in women is WRONG .. and everything we thought about anemia in children is wrong .." So in effect they are saying .. "that guy in Calgary .. is .. right .." So .. Try to keep .. up .. Eh .. Who loves ya. Tom SignatureJesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://pages.ivillage.com/ironjustice/manisaherbivore DEAD PEOPLE WALKING http://pages.ivillage.com/ironjustice/deadpeoplewalking > iron accumulation found in these patients is caused by unknown mechanisms >The iron > accumulation found in these patients is instead caused by other unknown > mechanisms that need further studies to be clarified. Yet another own goal ? BTW You can stop hiding now - tha nasty badger has gone back to the UK >Subject: Re: Iron accumulation in HIV-infected patients >From: "Manky Badger" spam@puritanDOTfreeserve.FULLSTOPcoSPOTuk [quoted text clipped - 10 lines] > >BTW You can stop hiding now - tha nasty badger has gone back to the UK Deem yourself lucky .. that your ability to FIND a person mirrors your abilities in .. medicine .. Because the last fk who raised his hand to me .. had a bitch of a time finding a wheelchair .. Dig .. ? Comprendez .. ? Underfkgstand .. ? <<snip>> iron accumulation found in these patients is caused by unknown mechanisms <<snip>> Biometals. 2004 Aug;17(4):443-50. Related Articles, Links Effects of AZT on cellular iron homeostasis. Bozzi A, Brisdelli F, D'Alessandro AM, D'Andrea G, Lizzi AR, Rinaldi AC, Oratore A. Department of Biomedical Sciences and Technologies, University of L'Aquila, Via Vetoio, Coppito 2, 67100 L'Aquila, Italy. bozzi@cc.univaq.it 3'-azido-3'-deoxythymidine (AZT), the first chemotherapeutic drug approved by FDA for treatment of HIV-infected patients and still used in combination therapy, has been shown to induce, upon prolonged exposure, severe bone marrow toxicity manifested as anemia, neutropenia and siderosis. These toxic effects are caused by inhibition of heme synthesis and, as a consequence, transferrin receptor (TfR) number appears increased and so iron taken up by cells. Since iron overload can promote the frequency and severity of many infections, siderosis is viewed as a further burden for AIDS patients. We have previously demonstrated that AZT-treated K562 cells showed an increase of the number of TfRs located on the surface of the plasma membrane without affecting their biosynthesis, but slowing down their endocytotic pathway. In spite of the higher number of receptors on the plasma-membrane of AZT-treated cells, intracellular accumulation of iron showed a similar level in control and in drug-exposed cells. The chelating ability of AZT and of its phosphorylated derivatives, both in an acellular system and in K562 cells, was also checked. The results demonstrated that AZT and AZTMP were uneffective as iron chelators, while AZTTP displayed a significant capacity to remove iron from transferrin (Tf). Our results suggest that AZT may be not directly involved in the iron overloading observed upon its prolonged use in AIDS therapy. The iron accumulation found in these patients is instead caused by other unknown mechanisms that need further studies to be clarified. PMID: 15259365 [PubMed - in process] -------------------------------------------------------------------------- ------ Who loves ya. Tom SignatureJesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://pages.ivillage.com/ironjustice/manisaherbivore DEAD PEOPLE WALKING http://pages.ivillage.com/ironjustice/deadpeoplewalking 1: Food Nutr Bull. 2003 Sep;24(3):268-74 Recent experience with fortification of foods and beverages with iron for the control of iron-deficiency anemia in Brazilian children. Beinner MA, Lamounier JA. Department of Health Sciences, University of Brasilia, Brazil. mbeinner@yahoo.com Iron-deficiency-anemia affects 30% of the world population. Women of reproductive age and children are the most affected. Iron supplementation in the form of tablets and syrups has not been successful in developing countries, and iron deficiency is still the most important deficiency related to malnutrition. Iron-deficiency anemia affects physical and cognitive development at an early age in children, often resulting in irreversible outcomes. Studies from the last two decades have shown that the prevalence of iron-deficiency anemia can be reduced given adequate investments and political will directed at iron fortification of foods and liquids. A successful low-cost iron-fortification program incorporates implementation and strategic use of communication for program inception where education is in the forefront. A review of the available reports from experience in Brazil with iron fortification of foods and liquids is presented. Publication Types: Review Review, Tutorial PMID: 14564931 [PubMed - indexed for MEDLINE] SignatureMike Collins UK Mike&heather-at-oakwellmount-dot-freeserve-dot-co-dot-uk >Subject: Re: Iron accumulation in HIV-infected patients >From: "Mike Collins" mike&heather@acornwellmount.freeserve.co.uk [quoted text clipped - 33 lines] > >PMID: 14564931 [PubMed - indexed for MEDLINE] Malnutrition .. ? Hmmm .. That would lead one to believe there may be a .. lack of .. food .. IN .. the study group .. But .. THAT .. in no way has any BEARING on .. iron deficiency .. in NORMAL .. nourished .. people .. does it .. Nope .. it doesn't .. Who loves ya. Tom SignatureJesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://pages.ivillage.com/ironjustice/manisaherbivore DEAD PEOPLE WALKING http://pages.ivillage.com/ironjustice/deadpeoplewalking >> Subject: Re: Iron accumulation in HIV-infected patients >> From: "Mike Collins" mike&heather@acornwellmount.freeserve.co.uk [quoted text clipped - 48 lines] > But .. THAT .. in no way has any BEARING on .. iron deficiency .. in > NORMAL .. nourished .. people .. does it .. Well said. Actually it does have a bearing on normally fed people but is even more true (certainly in Britain) of the large percentage of young women who are undernourished because they are vegetarian. Avoiding iron deficiency anaemia on this unnatural diet is much harder than the more natural omnivorous diet we evolved to eat. But with sufficient iron supplementation even vegetarians can avoid the problems of iron deficiency. SignatureMike Collins UK Mike&heather-at-oakwellmount-dot-freeserve-dot-co-dot-uk >Subject: Re: Iron accumulation in HIV-infected patients >From: "Mike Collins" mike&heather@acornwellmount.freeserve.co.uk [quoted text clipped - 61 lines] >But with sufficient iron supplementation even vegetarians can avoid the >problems of iron deficiency. The ONLY way they are deficient is if they simply don't .. eat .. EVERY food contains iron and if the body needs it .. it gets it .. It is found in exhaust fumes .. ------------------------------------------------------ Hunt JR. Nonheme iron absorption, fecal ferritin excretion, and blood indexes of iron status in women consuming controlled lactoovovegetarian diets for 8 wk. Am J Clin Nutr 69:944-52, 1999. Iron absorption from vegetarian diets is a concern because these diets eliminate meat, which contains considerable amounts of highly absorbable iron, and because these diets commonly contain more inhibitors of iron absorption, such as phytic acid. Nonheme iron absorption, blood indices of iron status, and fecal ferritin excretion were measured in women consuming controlled lacto-ovo-vegetarian and non-vegetarian diets. Twenty-one women of child-bearing age consumed both weighed diets for 8 wk each. In comparison to the non-vegetarian diet, the lacto-ovo-vegetarian diet contained similar amounts of iron and calcium, about 20% more ascorbic acid from fruits and vegetables, and 3 times as much phytic acid from whole grains and legumes, but no meat, poultry or fish. The results indicated 1) a 70% decrease in nonheme iron absorption from a lacto-ovo-vegetarian diet, 2) an associated decrease in fecal ferritin excretion, suggesting partial physiological adaptation to increase the efficiency of iron absorption, and 3) an insensitivity of blood iron indices, including serum ferritin, to substantial differences in dietary iron absorption for 8 weeks. These findings are consistent with other studies showing that vegetarians have lower body iron stores, but not necessarily a higher risk of anemia or iron deficiency under these dietary conditions ----------------------------------------- Who loves ya. Tom SignatureJesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://pages.ivillage.com/ironjustice/manisaherbivore DEAD PEOPLE WALKING http://pages.ivillage.com/ironjustice/deadpeoplewalking > >Subject: Re: Iron accumulation in HIV-infected patients >>From: "Manky Badger" spam@puritanDOTfreeserve.FULLSTOPcoSPOTuk [quoted text clipped - 22 lines] > Comprendez .. ? > Underfkgstand .. ? Why so confrontational? Why can't you disagree without being disagree-able ? It's a shame you chose to avoid what could have been a scintillating discussion. I've so many questions for you, things I'd like to ask... >Subject: Re: Iron accumulation in HIV-infected patients >From: "Manky Badger" spam@puritanDOTfreeserve.FULLSTOPcoSPOTuk [quoted text clipped - 33 lines] >to avoid what could have been a scintillating discussion. I've so many >questions for you, things I'd like to ask... But then you may have embarrassed yourself by .. peeing yourself by my .. presence .. or as in the case of women .. have your knees buckle .. In YOUR case .. either one might happen .. Who loves ya. Tom SignatureJesus Was A Vegetarian! http://jesuswasavegetarian.7h.com Man Is A Herbivore! http://pages.ivillage.com/ironjustice/manisaherbivore DEAD PEOPLE WALKING http://pages.ivillage.com/ironjustice/deadpeoplewalking > >Subject: Re: Iron accumulation in HIV-infected patients >>From: "Manky Badger" spam@puritanDOTfreeserve.FULLSTOPcoSPOTuk [quoted text clipped - 40 lines] > > In YOUR case .. either one might happen .. We'll find out next time I'm over...... |
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