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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution of colloids and labeled cells in organs is influenced by their intrinsic properties and by the state of the investigated subject. Iron deficiency remains an unsolved nutritional problem all over the world; one of its severe consequences is anemia. Because iron metabolism principally takes place in the liver, spleen, bone marrow, skeletal muscle and blood, we studied the effect of iron deficiency anemia on the biodistribution of 99mTc phytate, 99mTc gelatin colloid and 99mTc RBC (red blood cells labeled with 99mTc). Our results show that iron deficiency anemia modifies the pattern of biodistribution of the two colloids assayed. However, this behavior is different for both of them. This work contributes to studies that kinetically and statistically establish that iron deficiency anemia induces a significant inversion in the spleen-liver activity relationship when centellographic studies are performed with colloids such as 99mTc phytate.
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PMID:Effect of iron deficiency anemia on the biodistribution of 99mTc radiopharmaceuticals. 1672 Feb 52

Iron deficiency is the most widespread nutritional disorder in the world, affecting an estimated 1.2 billion people. Its prevalence is particularly high in developing countries (Africa, Asia, South America), but iron deficiency remains a public health problem in industrialised countries. Three successive stages of iron deficiency can be distinguished: iron store depletion, iron-deficient erythropoesis and iron-deficiency anemia. Investigations of iron deficiency should take into account the clinical background. In groups at risk (infants and children, women of childbearing age, pregnant women), management is limited to nutritional inquiries, gynecological examination, and oral iron supplementation. In men and post-menopausal women, iron deficiency is assumed to result from occult gastrointestinal bleeding, and this may necessitate upper and lower gastrointestinal endoscopy. Benign lesions are more frequently found in the upper digestive tract than in the lower digestive tract. When these investigations are negative and iron supplementation is unsuccessful, video-capsule endoscopy is recommended. Oral iron treatment is based on ferrous salts (200 mg/d). The duration of treatment depends on the severity of iron deficiency, ranging from three months for iron store depletion and iron-deficient erythropeisis to six months for iron-deficiency anemia.
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PMID:[Human iron deficiency]. 1673 92

Iron (Fe) is an essential trace metal involved in numerous cellular processes. Iron deficiency (ID) is reported as the most prevalent nutritional problem worldwide. Increasing evidence suggests that ID is associated with altered neurotransmitter metabolism and a risk factor for manganese (Mn) neurotoxicity. Though recent studies have established differences in which the female brain responds to ID-related neurochemical alterations versus the male brain, little is known about the interactions of dietary ID, Mn exposure, and sex on gamma-amino butyric acid (GABA). Male and female Sprague-Dawley rats were randomly divided into four dietary treatment groups: control (CN), control/Mn supplemented, ID, and ID/Mn supplemented. After 6 weeks of treatment, both ID diets caused a highly significant decrease in Fe concentrations across all brain regions compared to CN in both sexes. Both ID and Mn supplementation led to significant accumulation of Mn across all brain regions in both sexes. There was no main effect of sex on Fe or Mn accumulation. Striatal synaptosomes were utilized to examine the effect of dietary intervention on (3)H-GABA uptake. At 4 weeks, there was a significant correlation between Fe concentration and (3)H-GABA uptake in male rats (p < 0.05). At 6 weeks, there was a significant inverse correlation between Mn concentration and (3)H-GABA uptake in male and female rats and a postitive correlation between Fe concentration and (3)H-GABA uptake in female rats (p < 0.05). In conclusion, ID-associated Mn accumulation is similar in both sexes, with Mn levels affecting GABA uptake in both sexes in a comparable fashion.
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PMID:Brain manganese accumulation is inversely related to gamma-amino butyric acid uptake in male and female rats. 1703 2

Iron deficiency is a major human nutritional problem wherever plant-based diets are common. Using synchrotron x-ray fluorescence microtomography to directly visualize iron in Arabidopsis seeds, we show that iron is localized primarily to the provascular strands of the embryo. This localization is completely abolished when the vacuolar iron uptake transporter VIT1 is disrupted. Vacuolar iron storage is also critical for seedling development because vit1-1 seedlings grow poorly when iron is limiting. We have uncovered a fundamental aspect of seed biology that will ultimately aid the development of nutrient-rich seed, benefiting both human health and agricultural productivity.
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PMID:Localization of iron in Arabidopsis seed requires the vacuolar membrane transporter VIT1. 1712 12

Iron deficiency responses were investigated in roots of soybean, a Strategy I plant species. Soybean responds to iron deficiency by decreasing growth, both at the root and shoot level. Chlorotic symptoms in younger leaves were evident after a few days of iron deficiency, with chlorophyll content being dramatically decreased. Moreover, several important differences were found as compared with other species belonging to the same Strategy I. The main differences are (i) a lower capacity to acidify the hydroponic culture medium, that was also reflected by a lower H(+)-ATPase activity as determined in a plasma membrane-enriched fraction isolated from the roots; (ii) a drastically reduced activity of the phosphoenolpyruvate carboxylase enzyme; (iii) a decrease in both cytosolic and vacuolar pHs; (iv) an increase in the vacuolar phosphate concentration, and (v) an increased exudation of organic carbon, particularly citrate, phenolics, and amino acids. Apparently, in soybean roots, some of the responses to iron deficiency, such as the acidification of the rhizosphere and other related processes, do not occur or occur only at a lower degree. These results suggest that the biochemical mechanisms induced by this nutritional disorder are differently regulated in this plant. A possible role of inorganic phosphate in the balance of intracellular pHs is also discussed.
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PMID:Iron deficiency differently affects metabolic responses in soybean roots. 1722 58

Iron deficiency is the most common human nutritional disorder in the world. Iron absorptive capacity of the small intestine is known to be much limited and therefore large quantities of iron salts must be used to treat iron deficiency. As a result, significant amounts of iron may reach the large intestine. This study compared the capacities of the small and large intestine to transfer luminal iron to the venous blood in relationship with the expression in epithelial cells of proteins involved in iron absorption using a pig model. Intracaecal injection of iron sulphate corresponding with 2.5 and 5.0 mg elemental iron per kg body mass resulted in modest, transient, but significant (p<0.05) increases in iron concentration in the portal blood plasma. By comparing portal blood plasma iron concentrations following injection in the duodenal and caecal lumen, we calculated that 5 h after injection, iron colonic absorption represented approximately 14% of duodenal absorption. Caecal and proximal colon mucosa accumulated iron to a much lower extent than the duodenal mucosa. Isolated colonocytes were found to express divalent metal transporter (DMT1) and ferritin, but to a lesser extent than the duodenal enterocytes. Ferroportin was highly expressed in colonocytes. In these cells as well as in enterocytes ferroportin was found to be glycosylated. In short term experiments and at a concentration in the range of that measured in the aqueous phases recovered from the large intestine luminal content after iron injection, iron sulphate did not alter colonocyte viability. We concluded that the colonic epithelial cells that express proteins involved in iron absorption are able to transfer luminal iron to the venous blood even if its relative participation in the overall intestinal absorption appears to be modest under our experimental conditions.
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PMID:Comparative capacities of the pig colon and duodenum for luminal iron absorption. 1748 59

Iron deficiency, anemia, is the most prevalent nutritional problem in the world today. The objective of this study was to consider the effectiveness of consumption of iron fortified ready-to-eat cereal and pumpkin seed kernels as two sources of dietary iron on status of iron nutrition and response of hematological characteristics of women at reproductive ages. Eight healthy female, single or non pregnant subjects, aged 20-37 y consumed 30 g of iron fortified ready-to-eat cereal (providing 7.1 mg iron/day) plus 30 g of pumpkin seed kernels (providing 4.0 mg iron/day) for four weeks. Blood samples collected on the day 20 of menstrual cycles before and after consumption and indices of iron status such as reticulocyte count, hemoglobin (Hb), hematocrit (Ht), serum ferritin, iron, total iron-binding capacity (TIBC), transferrin and transferrin saturation percent were determined. Better response for iron status was observed after consumption period. The statistical analysis showed a significant difference between the pre and post consumption phase for higher serum iron (60 +/- 22 vs. 85 +/- 23 ug/dl), higher transferrin saturation percent (16.8 +/- 8.0 vs. 25.6 +/- 9.0%), and lower TIBC (367 +/- 31 vs. 339 +/- 31 ug/dl). All individuals had higher serum iron after consumption. A significant positive correlation (r=0.981, p=0.000) between the differences in serum iron levels and differences in transferrin saturation percentages and a significant negative correlation (r=-0.916, p<0.001) between the differences in serum iron levels and differences in TIBC was found, as well. Fortified foods contribute to maintaining optimal nutritional status and minimizing the likelihood of iron insufficiencies and use of fortified ready-to-eat cereals is a common strategy. The results showed that adding another food source of iron such as pumpkin seed kernels improves the iron status. Additional and longer studies using these two food products are recommended to further determine the effect of iron fortification on iron nutrition and status among the target population, and mainly in young children, adolescents, women of reproductive ages and pregnant women.
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PMID:Impact of daily consumption of iron fortified ready-to-eat cereal and pumpkin seed kernels (Cucurbita pepo) on serum iron in adult women. 1819 98

Manganese (Mn) deficiency is an important plant nutritional disorder in many parts of the world. Barley (Hordeum vulgare) genotypes differ considerably in their ability to grow in soils with low Mn(2+) availability. Differential genotypic Mn efficiency can be attributed to differences in Mn(2+) uptake kinetics in the low nanomolar concentration range. However, the molecular basis for these differences has not yet been clarified. We present here the identification and characterization of the first barley gene encoding a plasma membrane-localized metal transport protein able to transport Mn(2+). The gene is designated HvIRT1 (for IRON-REGULATED TRANSPORTER1) because it belongs to the ZIP gene family and has a high similarity to rice (Oryza sativa) OsIRT1. A novel yeast uptake assay based on inductively coupled plasma-mass spectrometry analysis of 31 different metal and metalloid ions showed that the HvIRT1 protein, in addition to Mn(2+), also transported Fe(2+)/Fe(3+), Zn(2+), and Cd(2+). Both Mn and iron deficiency induced an up-regulation of HvIRT1 in two barley genotypes differing in Mn efficiency, but the expression levels in all cases were highest (up to 40%) in the Mn-efficient genotype. The higher expression of HvIRT1 correlated with an increased Mn(2+) uptake rate. We conclude that HvIRT1 is an important component controlling Mn(2+) uptake in barley roots and contributes to genotypic differences in Mn(2+) uptake kinetics.
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PMID:Manganese efficiency in barley: identification and characterization of the metal ion transporter HvIRT1. 1861 14

Unlike other essential trace elements (e.g., zinc and iron) it is the toxicity of manganese (Mn) that is more common in human populations than its deficiency. Data suggest alterations in dopamine biology may drive the effects associated with Mn neurotoxicity, though recently gamma-aminobutyric acid (GABA) has been implicated. In addition, iron deficiency (ID), a common nutritional problem, may cause disturbances in neurochemistry by facilitating accumulation of Mn in the brain. Previous data from our lab have shown decreased brain tissue levels of GABA as well as decreased (3)H-GABA uptake in synaptosomes as a result of Mn exposure and ID. These results indicate a possible increase in the concentration of extracellular GABA due to alterations in expression of GABA transport and receptor proteins. In this study weanling-male Sprague-Dawley rats were randomly placed into one of four dietary treatment groups: control (CN; 35mg Fe/kg diet), iron-deficient (ID; 6mg Fe/kg diet), CN with Mn supplementation (via the drinking water; 1g Mn/l) (CNMn), and ID with Mn supplementation (IDMn). Using in vivo microdialysis, an increase in extracellular GABA concentrations in the striatum was observed in response to Mn exposure and ID although correlational analysis reveals that extracellular GABA is related more to extracellular iron levels and not Mn. A diverse effect of Mn exposure and ID was observed in the regions examined via Western blot and RT-PCR analysis, with effects on mRNA and protein expression of GAT-1, GABA(A), and GABA(B) differing between and within the regions examined. For example, Mn exposure reduced GAT-1 protein expression by approximately 50% in the substantia nigra, while increasing mRNA expression approximately four-fold, while in the caudate putamen mRNA expression was decreased with no effect on protein expression. These data suggest that Mn exposure results in an increase in extracellular GABA concentrations via altered expression of transport and receptor proteins, which may be the basis of the neurological characteristics of manganism.
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PMID:Manganese exposure alters extracellular GABA, GABA receptor and transporter protein and mRNA levels in the developing rat brain. 1877 89

Saccharomyces cerevisiae (baker's yeast) is an excellent model for understanding fundamental biological mechanisms that are conserved in Nature and that have an impact on human disease. The metal iron is a redox-active cofactor that plays critical biochemical roles in a broad range of functions, including oxygen transport, mitochondrial oxidative phosphorylation, chromatin remodelling, intermediary metabolism and signalling. Although iron deficiency is the most common nutritional disorder on the planet, little is known about the metabolic adjustments that cells undergo in response to iron deficit and the regulatory mechanisms that allow these adaptive responses. In the present article, we summarize recent work on genome-wide metabolic reprogramming in response to iron deficiency, mediated by specific mRNA degradation mechanisms that allow S. cerevisiae cells to adapt to iron deficiency.
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PMID:Post-transcriptional regulation of gene expression in response to iron deficiency: co-ordinated metabolic reprogramming by yeast mRNA-binding proteins. 1879 94


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