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

Aluminum (Al) is a simple trivalent cation incapable of redox changes. The toxicity of the metal has been the subject of much controversy in the past few decades. Although it has been generally believed that the metal is innocuous to human health, a causal role for Al has been established in dialysis dementia (Alfrey et al., 1976), osteomalacia (Bushinsky et al., 1995) and microcytic anemia without iron deficiency (Touam et al., 1983). Aluminum has also been implicated in Alzheimer's disease (AD) although a direct causal role has not been determined. The exact mechanism of Al toxicity is not known. However, there are several lines of evidence that show the metal's capacity to exacerbate oxidative events. The present review is intended to propose a coherent pathway linking Al-induced oxidative events to Alzheimer's disease. The preliminary segment is an introduction to reactive oxygen species and their potential involvement in the pathogenesis of AD and the generation of an inflammatory response. Evidence on the relation between AD and inflammatory processes is also presented. The epidemiological and clinical evidence of Al neurotoxicity is summarized in the second section of the review. Finally, a hypothesis indicating that aluminum can exacerbate AD by activating ROS generation and initiation of an inflammatory cascade is presented.
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PMID:Aluminum induced oxidative events and its relation to inflammation: a role for the metal in Alzheimer's disease. 1087 35

To understand the mechanisms responsible for aluminum (Al) toxicity and tolerance in plants, an expressed sequence tag (EST) approach was used to analyze changes in gene expression in roots of rye (Secale cereale L. cv Blanco) under Al stress. Two cDNA libraries were constructed (Al stressed and unstressed), and a total of 1,194 and 774 ESTs were generated, respectively. The putative proteins encoded by these cDNAs were uncovered by Basic Local Alignment Search Tool searches, and those ESTs showing similarity to proteins of known function were classified according to 13 different functional categories. A total of 671 known function genes were used to analyze the gene expression patterns in rye cv Blanco root tips under Al stress. Many of the previously identified Al-responsive genes showed expression differences between the libraries within 6 h of Al stress. Certain genes were selected, and their expression profiles were studied during a 48-h period using northern analysis. A total of 13 novel genes involved in cell elongation and division (tonoplast aquaporin and ubiquitin-like protein SMT3), oxidative stress (glutathione peroxidase, glucose-6-phosphate-dehydrogenase, and ascorbate peroxidase), iron metabolism (iron deficiency-specific proteins IDS3a, IDS3b, and IDS1; S-adenosyl methionine synthase; and methionine synthase), and other cellular mechanisms (pathogenesis-related protein 1.2, heme oxygenase, and epoxide hydrolase) were demonstrated to be regulated by Al stress. These genes provide new insights about the response of Al-tolerant plants to toxic levels of Al.
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PMID:Expressed sequence tag-based gene expression analysis under aluminum stress in rye. 1248 Oct 53

The resistance to erythropoietin, which is used to treat normochromic, normocytic anemia in chronic renal failure, can develop in patients with conditions such as iron deficiency, aluminum toxicity, hyperparathyroidism, chronic inflammatory diseases, and primary hematological disorders. We found amyloidosis in the bone marrow of a woman without any other etiology for erythropoietin resistance who was undergoing chronic hemodialysis. Her anemia did not improve, despite 6 months of erythropoietin therapy. Bone marrow amyloidosis was found to be the reason for erythropoietin-resistant anemia in our patient with chronic renal failure and renal anemia. We present the case of bone marrow amyloidosis because it is a very rare cause of erythropoietin resistance.
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PMID:Bone marrow amyloidosis with erythropoietin-resistant anemia in a patient undergoing chronic hemodialysis treatment. 1291 Nov 89

Iron deficiency is the most frequent form of nutritional anemia, and infants represent one of the major risk groups. The present study was meant to evaluate the iron content of infant diets cooked in iron utensils and in aluminum utensils prepared by volunteer mothers at home. The iron content was analyzed by atomic absorption spectrophotometry. The increase of iron in diets cooked in iron utensils was 12 to 44 times greater than in diets cooked in aluminum utensils. The pH and moisture of the diets cooked in the two types of utensils did not differ in a statistically significant manner. On the basis of these results, it was estimated that the increase in daily iron supply obtained by cooking the diet in iron utensils would be sufficient to satisfy the iron requirements of infants.
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PMID:[Iron content of infant diets cooked in iron utensils]. 1468 17

The anemia of chronic kidney disease is associated with cardiovascular disease, decreased quality of life, and mortality. The introduction of recombinant human erythropoietin (rHuEPO) has transformed the management of this condition. However, a significant proportion of patients fail to respond to even high doses of rHuEPO. Several factors have been implicated in the hyporesponsiveness to rHuEPO. Iron deficiency, whether absolute or functional, is considered the most important, and maintenance of adequate iron stores reduces rHuEPO requirements among patients on hemodialysis. However, traditional indices of iron that are currently utilized may not reflect iron stores accurately, and there is also increasing concern regarding the potential long-term toxicity of parenteral iron therapy. Infection and inflammation also influence the response to rHuEPO, both by disruption of iron metabolism and by eliciting the release of cytokines that inhibit erythropoiesis. Oxidative stress may contribute to rHuEPO hyporesponsiveness directly by promoting lipid peroxidation in cell membranes, leading to increased erythrocyte fragility and reduced life span and also through its strong association with inflammation. Severe hyperparathyroidism can lead to a reduced number of erythroid progenitor cells. Inadequate dialysis dose, aluminum overload, nutritional factors such as deficiencies of carnitine, vitamin B12, folic acid, and vitamin C can also reduce the efficacy of rHuEPO therapy. Hyporesponsiveness to rHuEPO presents a challenge to both diagnosis and management in an era where optimizing response to rHuEPO is critical both in limiting the burgeoning costs of anemia management and improving clinical outcomes in the dialysis population.
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PMID:Managing erythropoietin hyporesponsiveness. 1655 Dec 93

Anemia is a frequent complication of chronic kidney disease (CKD). Inadequate production of erythropoietin by the failing kidneys leads to decreased stimulation of the bone marrow to produce red blood cells (RBCs). Anemia of CKD develops early and worsens with progressive renal insufficiency. Although over 40% of patients with CKD are anemic, anemia in this population is under-recognized and undertreated. Of considerable importance, anemia is a risk factor for cardiovascular disease and is associated with higher rates of hospitalization and mortality. Despite the availability of erythropoiesis-stimulating proteins (ESPs) to stimulate RBC production in CKD patients, approximately three fourths of patients initiating dialysis have a hemoglobin <11 g/dL. The recognition of anemia of CKD begins with an estimation of glomerular filtration rate (GFR), which can be far lower than a normal serum creatinine might suggest, especially in the elderly and in those with poor nutrition and muscle mass. If GFR is <60 mL/min/1.73 m(2), hemoglobin should be checked. The anemia is diagnosed when the hemoglobin is <12 g/dL in a man or a postmenopausal woman, or <11 g/dL in a premenopausal woman. The cause of anemia should be investigated in these individuals; this can range from erythropoietin deficiency due to CKD, to deficiency of vitamin B(12) and/or folate, iron deficiency, blood loss, inflammation, malignancy, and aluminum intoxication. After other causes of anemia have been excluded, CKD is the most likely etiology, and it should be treated with an ESP. Currently, epoetin alfa and darbepoetin alfa are the only 2 ESPs approved for use in the United States. Extended dosing of ESP has potential advantages for the patient and may also improve resource utilization. Consequently, both agents have been tested for dosing at extended intervals. Adequate iron stores--defined as transferrin saturation >20% and ferritin >100 mg--as well as ESP administration are needed to produce an appropriate increase in hemoglobin. Poor response to treatment with ESP can be due to many factors, including presence of iron deficiency, inflammation, continued blood loss, and hemoglobinopathy.
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PMID:Practical approach to the diagnosis and treatment of anemia associated with CKD in elderly. 1709 34

Recombinant human erythropoietin (rHuEPO) has transformed the management chronic renal failure (CKD) and considerably improved the outcome of patients on regular chronic dialysis. However, a significant number of patients fail to respond to high of Erythropoiesis-stimulating agents (ESAs) and several causes of inadequate response to epoetin therapy have been identified. Some factors, such as gender, age, length of time on dialysis, type of dialysis and co-morbidities such as hemoglobinopathy, are not susceptible to clinical intervention. However, many other factors can be adjusted. Iron deficiency, whether functional or absolute, is the most common factor that limits the response to rHuEPO. Monitoring of iron parameters and a large use of iron supplementation result in an efficient epoetin response. Infection and inflammation have been shown to reduce responsiveness to ESAs by disrupting iron metabolism and increasing the release of pro-inflammatory cytokines that inhibit erythropoiesis. Increase dialysis dose is associated with improvements in anemia correction and reduced requirements for ESAs. Severe hyperparathyroidism and aluminum overload lead to a reduced number of responsive erythroid progenitor cells. Finally, a number of nutritional factors, such as deficiencies of carnitine, vitamin B12, folic acid, and vitamin C, are susceptible to alter erythropoiesis. Optimizing patient response to ESAs therefore requires consideration of many of well-established factors and is important for both patient outcomes and cost of treatment.
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PMID:[Factors affecting the response to erythropoiesis-stimulating agents]. 1737 70

Iron deficiency anemia is common in people with chronic kidney disease (CKD) and its importance in supporting erythropoiesis is unquestioned especially in those patients treated with erythropoietin. Clinical symptomatology such as fatigability, cold intolerance, failure to concentrate and poor effort intolerance is often attributed to anemia or uremia. That iron deficiency, per se, can cause these symptoms is poorly recognized. Clinical and animal studies that support the benefits of iron supplementation, independent of increasing hemoglobin, such as those on immune function, physical performance, thermoregulation, cognition, and restless leg syndrome and aluminum absorption is the subject of this narrative review.
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PMID:Nonhematological benefits of iron. 1780 3

The TaMATE1B gene (for multidrug and toxic compound extrusion) from wheat (Triticum aestivum) was isolated and shown to encode a citrate transporter that is located on the plasma membrane. TaMATE1B expression in roots was induced by iron deficiency but not by phosphorus deficiency or aluminum treatment. The coding region of TaMATE1B was identical in a genotype showing citrate efflux from root apices (cv Carazinho) to one that lacked citrate efflux (cv Egret). However, sequence upstream of the coding region differed between these two genotypes in two ways. The first difference was a single-nucleotide polymorphism located approximately 2 kb upstream from the start codon in cv Egret. The second difference was an 11.1-kb transposon-like element located 25 bp upstream of the start codon in cv Carazinho that was absent from cv Egret. The influence of these polymorphisms on TaMATE1B expression was investigated using fusions to green fluorescent protein expressed in transgenic lines of rice (Oryza sativa). Fluorescence measurements in roots of rice indicated that 1.5- and 2.3-kb regions upstream of TaMATE1B in cv Carazinho (which incorporated 3' regions of the transposon-like element) generated 20-fold greater expression in the apical 1 mm of root compared with the native promoter in cv Egret. By contrast, fluorescence in more mature tissues was similar in both cultivars. The presence of the single-nucleotide polymorphism alone consistently generated 2-fold greater fluorescence than the cv Egret promoter. We conclude that the transposon-like element in cv Carazinho extends TaMATE1B expression to the root apex, where it confers citrate efflux and enhanced aluminum tolerance.
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PMID:Transposon-mediated alteration of TaMATE1B expression in wheat confers constitutive citrate efflux from root apices. 2320 28

Heavy metals and trace elements play an important role in relation to the physiology and pathology of the nervous system. Neurologic diseases related to disorders of metabolism of copper and iron are reviewed. Copper disorders are divided into two classes: ATP7A- or ATP7B-related inherited copper transport disorders (Menkes disease, occipital horn syndrome, ATP7A-related distal motor neuropathy, and Wilson disease) and acquired diseases associated with copper deficiency or copper excess. Iron brain disorders are divided into genetic neurodegeneration with brain iron accumulation (NBIA, neuroferritinopathy, and aceruloplasminemia), genetic systemic iron accumulation with neurologic features (hemochromatosis), and acquired diseases associated with iron excess (superficial siderosis) or iron deficiency (restless leg syndrome). The main features of cadmium, lead, aluminum, mercury, and manganese toxicity are summarized.
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PMID:Disorders of heavy metals. 2436 57


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