Iron status

Leaf intercellular fluid harvested from healthy plants (IP) reflects the environmental conditions that may be encountered by bacterial cells during pathogenesis [9]. To examine whether the expression of pelD relative to pelEv.uidA was influenced by the iron status in IP, pelD.-.uidA activity was recorded in bacterial cells grown under such conditions. Activity of pelD uidA was andysed in wild-type and cbrE-1 (ch sobactin deficient mutant)backgrounds. 

Although EPO deficiency is the primary cause of CKD anemia, iron deficiency is often present, and it is essential to assess and monitor the CKD patient s iron status (NKF-K/DOQI guidelines). Iron stores in patients with CKD should be maintained so that transferrin saturation (TSAT) is greater than 20% and serum ferritin is greater than 100 ng/mL (100 mcg/L or 225 pmol/L). If iron stores are not maintained appropriately, epoetin or darbepoetin will not be effective, and most CKD patients will require iron supplementation. Oral iron therapy can be used, but it is often ineffective, particularly in CKD patients on dialysis. Therefore, intravenous iron therapy is used extensively in these patients. Details of the pharmacology, pharmacokinetics, adverse effects, interactions, dose, and administration of erythropoietin and iron products have been discussed previously. 

When initiating erythropoietin products, assess the patient s iron status. 

Gastrointestinal absorption of lead is influenced by dietary and nutritional calcium and iron status. An inverse relationship has been observed between dietary calcium intake and PbB concentration (Mahaffey et al. 1986 Ziegler et al. 1978). Complexation with calcium (and phosphate) in the gastrointestinal tract and competition for a common transport protein have been proposed as possible mechanisms for this interaction (Barton et al. 1978a Heard and Chamberlain 1982). Absorption of lead from the... 

Pollitt E Univ of California, Administration, Davis, CA The effects of lead and iron interaction on behavioral development the effects of iron treatment on iron status, blood lead level, and behavioral development in children with elevated lead levels and iron deficiency U. S. Department of Agriculture, Competitive Research... 

Mahaffey KR, Annest JL. 1986. Association of erythrocyte protoporphyrin with blood lead level and iron status in the Second National Health and Nutrition Examination Survey, 1976-1980. Environ Res 41 327-338. 

Marcus AH, Schwartz J. 1987. Dose-response curves for erythrocyte protoporphyrin vs blood lead Effects of iron status. Environ Res 44 221-227. 

Morrison JN, Quatermann J. 1987. The relationship between iron status and lead absorption in rats. Biol Trace Element Res 14 115-126. 

Yip R, Norris TN, Anderson AS. 1981. Iron status of children with elevated blood lead concentrations. JPediatr 98 922-925. 

Zinc protoporphyrin IX is a normal metabolite that is formed in trace amounts during haem biosynthesis. However, in iron deficiency or in impaired iron utilization, zinc becomes an alternative substrate for ferrochelatase and elevated levels of zinc protoporphyrin IX, which has a known low affinity for oxygen, are formed. This zinc-for-iron substitution is one of the first biochemical responses to iron depletion, and erythrocyte zinc protoporphyrin is therefore a very sensitive index of bone-marrow iron status (Labbe et ah, 1999). In addition, zinc protoporphyrin may regulate haem catabolism by acting as a competitive inhibitor of haem oxygenase, the key enzyme of the haem degradation pathway. However, it has been reported... 

More detailed knowledge of the mechanisms of iron absorption from the gastrointestinal tract of mammals has advanced by leaps and bounds in the last few years, with the cloning of key participants at both the apical and basolateral faces of the mucosal endothelial cells. The extraordinarily far-sighted contribution of William Crosby and Marcel Conrad, nearly 40 years ago (Conrad and Crosby, 1963 Crosby, 1963), reminded us of the key role of body iron status in determining the level at which iron absorption will be set within the cells of the crypts of Lieberkiihn when they differentiate and move up to the villus tips to play their key role in... 

American Academy of Pediatrics, Committee on Nutrition. 1978B. Relationship between iron status and incidence of infection in infancy. Pediatrics 62, 246-250. 

Bailey. L.B. cl al. Folacin and Iron Status and Hematological Findings in Black and Spanish American Adolescents. On Geriatr. Sot,. 27, 444 1I982i. 

Infants with Iron Deficiency. B. l.o/off (Case Western Reserve University) and associates repotted that "Several consistent results have emerged from five studies of the behavior and development of infant with iron-deliciency anemia, a condition that affects at least 21) to 25 percent of the world s babies." All live studies used careful de lin it ions of iron status and included comparison groups without anemia All showed that infants with anemia scored lower on tests of mental development administered before treatment than infants without anemia did. 

Larsson G, Milsom I, Lindstedt G, Rybo G. The influence of a low-dose combined oral contraceptive on menstrual blood loss and iron status. Contraception 1992 46(4) 327-334. 

Absorption of iron by the individual varies with age, iron status, the amount and chemical form of the iron ingested, and with conditions in the gastrointestinal tract, only about 5—15% of iron in the diet being normally absorbed. Ferrous iron, as the sulphate, gluconate, fumarate or lactate or as ferrous ammonium sulphate, is appreciably taken up into the bloodstream from the duodenum, especially in the presence of ascorbic acid, a reducing agent. Little difference was found in the extent of their absorption between ferrous sulphate and the various chelates, but ferric ammonium citrate or polysaccharide complexes were only very poorly absorbed22)... 

Dietary NTA has also been shown to increase the iron status of lactating mice and their pups87. ... 

Greger JL, Chang MM, Radanowski GN. 1995. Comparison of tissue retention of aluminum and Ga-67 Effects of iron status in rats. Toxicology 100 1-9. 

Ittel TH, Kinzel S, Ortmanns A, et al. 1996. Effect of iron status on the intestinal absorption of aluminum A reappraisal. Kidney Int 50 1879-1888. 

The majority of body iron is not chelatable (iron from cytochromes and hemoglobin). There are two major pools of chelatable iron by DFO (19). The first is that delivered from the breakdown of red cells by macrophages. DFO competes with transferrin for iron released from macrophages. DFO will also compete with other plasma proteins for this iron, when transferrin becomes saturated in iron overload. The quantity of chelatable iron from this turnover is 20mg/day in healthy individuals and iron chelated from this pool is excreted in the urine (19). The second major pool of iron available to DFO is derived from the breakdown of ferritin and hemosiderin. The ferritin is catabolized every 72 hours in hepatocytes, predominantly within lysosomes (I). DFO can chelate iron that remains within lysosomes shortly after ferritin catabolism or once this iron reaches a dynamic, transiently chelatable, cytosolic low-molecular-weight iron pool (20). Cellular iron status, the rate of uptake of exogenous iron, and the rate of ferritin catabolism are influent on the level of a labile iron pool (21). Excess ferritin and... 

MuntaneJ, Mitjavila MT Rodriquez MC, etal. Dietary lipid and iron status modulate lipid peroxidation in rats with induced adjuvant arthritis. J Nutr 1995 125(7) 1930-1937. 

Campbell WW, Beard JL, Joseph LJ, et al. 1997. Chromium picolinate supplementation and resistive training by older men Efects on iron-status and hematologic indexes. Am J Clin Nutr 66 944-949. 

It has been further reported that not only the calcium metabolism but also other minerals and other aspects of mineral status may be influenced by CPPs. Ait-Oukhatar et al. (1997) found that in young iron-deficient rats, CPP-bound iron had a positive effect on some parameters of iron status and metabolism, such as mean cell volume, haemoglobulin and haematocrit, and a negative effect on some parameters, such as urine iron. Other parameters,... 

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