Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Normal and iron-deficient rats were exposed to 90% O2 at 760 Torr for 24 or 48 h. Erythrocyte response to hyperoxia was monitored by potassium (rubidium) influx studies, by storage stress, and by ultrastructural studies. Normal rat erythrocytes exhibited morphological changes and decrease of ouabain-sensitive potassium influx compared to unexposed controls. Both components of erythrocyte potassium influx were affected by iron deficiency. Erythrocytes from unexposed iron-deficient rats showed a 50% increase in ouabain-sensitive potassium influx compared to controls. Iron-deficient rats exposed to hyperoxia for 24 or 48 h, had erythrocytes with morphological changes. Erythrocytes of iron-deficient rats exposed for 24 h showed no influx change; those exposed for 48 h showed a decrease of ouabain-sensitive influx compared to erythrocytes of controls.
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PMID:Response of the iron-deficient erythrocyte in the rat to hyperoxia. 64 73

It is now apparent that the rate of microsomal drug metabolism in experimental animals is subject to alteration by such dietary deficiencies as protein, vatamins, fats and minerals. The evidence, both published and unpublished, showing the effects of iron, magnesium, and potassium dificiencies on the hepatic metabolism of foreign compounds in rats is discussed. Iron deficiency has been shown to lead to a marked stimulation in hepatic metabolism, in vitro and in vivo, of both Type I (aminopyrine) and Type II (aniline) substrates. Magnesium-deficient rats have been shown to have markedly lower in vivo and in vitro rates of hepatic drug metabolism, but the monovalent intracellular mineral potassium had no apparent effect on the in vitro enzymatic conversion of foreign compounds. Hypokalemia has been shown to alter the in vivo disposition of aminopyrine and pentobarbital as evidenced by an increased plasma half-life of aminopyrine and a longer pentobarbital sleeping time in potassium-deficient animals. Large segments of the world's population are in less than satisfactory nutritional status with respect to iron, magnesium, potassium, copper, and zinc and the relevancy to man of the data discussed must be ascertained. The role of dietary minerals in nonhepatic microsomal drug metabolism is also not yet known.
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PMID:Hepatic drug metabolism in iron-, magnesium- and potassium-deficient rats. 82 59

The influences of iron deficiency on the cochlear iron enzymes and adenosine triphosphatase were studied in 68 iron-deficient rats and 68 control rats (normal and with chronic anemia). A disorderly or topographic distribution and reduction or disappearance of the cochlear succinic dehydrogenase and peroxidase reaction products were found in 37.8% of the rats fed on a basic iron-deficient diet for 14 to 100 days. The activity of cochlear sodium-potassium-dependent adenosine triphosphatase in iron-deficient rats was slightly increased, compared to that in normal controls. These results suggest that iron deficiency would produce significant abnormalities of succinic dehydrogenase and peroxidase activity, which in turn would disturb cell respiration and initiate peroxidative damage to the inner ear cells, result in sensorineural hearing loss, or provide a pathologic basis for cochlear deafness.
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PMID:Changes in the cochlear iron enzymes and adenosine triphosphatase in experimental iron deficiency. 217 94

A group of 50 patients (26 men and 24 women, mean age 50 +/- 19 years and range 21 to 67) on chronic hemodialysis (HD) and with basal levels of hemoglobin (Hb) less than or equal to 8 g/dl was treated with recombinant human erythropoietin (r-HuEpo) during 3 months. r-HuEpo was started at 50 U/kg I.V. 3 times a week, immediately after each session of HD, for 4 weeks, and this dose was increased in steps of 25 U/kg until a Hb level of 12 g/dl or a maximum dose of 100 U/kg were reached. Complete blood counts and biochemical profile were performed before the first dose of r-HuEpo and once weekly and monthly respectively during the period of treatment. In 8 patients the red-cell life span was studied with cromium 51 labelled erythrocytes just before and after treatment. One patient had a grand mal seizure and the r-HuEpo was discontinued. In 44 patients the mean hematocrit increased from 21.8% to 32.1% and in the other 5 there were no response because of iron deficiency. There were no changes in leucocytes and platelets counts and consistent decreases in iron and ferritin serum concentrations were observed despite oral supplementation of iron. In the 8 patients studied the shortened erythrocyte survival did not suffer any significant variation with r-HuEpo. Predialysis creatinine, urea and phosphorus blood levels increased significantly at 3th month of treatment but there was no increase in potassium. In 32.6% of previously normotensive and hypertensive patients an increase in blood pressure was founded. Thrombosis of arteriovenous fistulas and other severe clinical side effects were not observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Treatment of anemia in patients with chronic kidney insufficiency in hemodialysis with erythropoietin]. 222 Apr 24

Therapy with recombinant human erythropoietin (rHuEPO) can reverse anemia and improve the quality of life in anemic hemodialysis patients. However, therapy is costly and must be used efficiently. An initial rHuEPO dose less than 50 U/kg intravenously three times weekly may be adequate to achieve a hematocrit of 30-33% in many patients. Acquired iron deficiency is a common problem during rHuEPO therapy and must be prevented with oral and parenteral iron replacement to maintain the efficacy of rHuEPO. Patients should be monitored carefully for additional problems including: an increase in blood pressure; onset of seizures or headaches; increased blood potassium, phosphate, and creatinine concentrations; enhanced coagulability resulting in dialyzer and vascular access clotting; and myalgias with a 'flu-like' syndrome.
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PMID:Practical approach to initiation of recombinant human erythropoietin therapy and prevention and management of adverse effects. 226 Jun 19

Fourteen nondialyzed patients with chronic renal insufficiency (serum creatinine 265 to 972 mumol/L [3.0 to 11.0 mg/dL]) and severe anemia (hematocrit less than 30%) were randomized to receive either recombinant human erythropoietin (r-HuEPO) or a placebo subcutaneously thrice weekly for 12 weeks or until reaching a hematocrit of 38% to 40%. Anemia was significantly ameliorated in the treated patients. No acceleration in the progression of renal failure (1/serum creatinine v time) or change in serum potassium was noted for either the placebo or treated group over the 12-week period. Six of seven treated patients had a significant decrease in serum ferritin and percent transferrin saturation (plasma iron/total iron-binding capacity). This resulted in functional iron deficiency and the requirement for iron supplementation. The average systolic and diastolic blood pressure did not differ significantly between the two groups of patients during the study. Quality of life was improved in all r-HuEPO-treated patients but not in those in the placebo group. This study demonstrates the safety and efficacy of r-HuEPO in the correction of anemia in predialysis patients without adverse effects on renal function over a 12-week period. Improved patient well-being as a result of the correction of anemia resulted in one patient refusing appropriate initiation of dialysis therapy.
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PMID:The use of recombinant human erythropoietin in the correction of anemia in predialysis patients and its effect on renal function: a double-blind, placebo-controlled trial. 268 5

During the past 20 years there have been great developments in the scientific understanding of the role of nutrition in health and physical performance. Epidemiological and physiological studies have provided evidence that certain forms of dietary behaviour may be linked with an increased risk of developing disorders such as high blood pressure, coronary artery disease and some cancers. This has resulted in dietary recommendations that are intended to reduce the incidence of these disorders in the community. The science of nutrition in relation to sports performance has progressed from empirical studies investigating the effects of dietary manipulations, such as restriction and supplementation, to the direct investigation of the physiological basis of the specific nutritional demands of hard physical exercise. This review is based on the premise that it is "what comes out' rather than "what goes in', which provides the clues to ideal nutrition for athletic performance. Various aspects of the physical demands of athletic exercise are viewed as stresses that induce specific biochemical, and hence nutritional, strains in the athlete. Training is the predominant demand in the athletic lifestyle. This is characterised by acute bouts of high power output. During one hour of hard training an athlete may expend 30% of his or her total 24-hour energy output. These high power outputs have important implications for energy substrate and water requirements. Carbohydrate, specifically muscle glycogen, is an obligatory fuel for the high power outputs demanded by athletic sports. Muscle glycogen is a limiting factor in hard exercise because it is held in limited amounts, utilised rapidly by intense exercise, and fatigue occurs when it is depleted to low levels in the active muscles. Liver glycogen may also be exhausted by hard exercise and low blood glucose contributes to fatigue. High sweat rates are demanded during severe exercise and large water deficits commensurate with energy expenditure are incurred during extended periods of hard training and competition. Salt, potassium, and magnesium are lost in nutritionally significant amounts in the sweat, but vitamins and trace elements are not. Adaptive mechanisms protect athletes against electrolyte depletion. Iron loss in sweat may contribute to the iron deficiency seen in some endurance runners. Protein is degraded and amino acids are oxidised during physical exercise. Protein is also retained during muscle building training. Recent investigations indicate that the minimal protein requirements of athletes may be substantially higher than those for sedentary persons.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Nutrition and sports performance. 639 Jun 9

Studies of red cell metabolism, erythropoeitin concentration, iron and folate status were made in 48 children with protein-energy malnutrition in Johannesburg (altitude 1800 m). Biochemical evidence of iron deficiency was presented in 26% cases on admission and developed in 90% during recovery. Biochemical evidence of folate deficiency was present in 14% of cases on admission and resolved on dietary therapy alone. Serum erythropoeitin was increased on admission and remained elevated during recovery. There was no relationship between serum erythropoeitin and Hb concentrations. Key enzymes in the red cell glycolytic and hexose monophosphate pathways and red cell membrane showed increased activity. Red cell adenosine triphosphate concentration was increased and unstable. Red cell potassium was decreased and, in the fatal cases, red cell sodium was increased. The possible significance and practical implications of these findings are discussed.
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PMID:Mechanisms of anemia in protein-energy malnutrition in Johannesburg. 646 Dec 44

Ionizing radiation is currently used for prevention of transfusion associated graft versus host disease (TAGVHD). As radiation damage is associated with the production of activated oxygen species, the aim of this study was to observe the immediate effect of ionizing radiation on red cell membrane and intracellular oxidative defense systems. Neonatal and iron deficiency (IDA) cells, known for their increased sensitivity to oxidative stress, were chosen and compared with normal cells. Irradiation was performed in doses of 1500 cGy, 3000 cGy and 5000 cGy. GSH and methemoglobin levels and the activity of different antioxidant enzymes, measured under optimal in vitro conditions, were preserved in all cells after irradiation. Only radiation at the highest does of 5000 cGy, caused significant potassium leakage in neonatal cells and insignificant increase in IDA cells. Thus, cells with increased sensitivity to oxidative stress are more susceptible to damage by ionizing radiation than normal cells.
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PMID:Effect of radiation on red cell membrane and intracellular oxidative defense systems. 872 21

Red blood cell formation relies on the contributions of a variety of substances, including iron, vitamins, and protein. Therapeutic intervention with Epoetin alfa changes the requirements for these erythropoietic ingredients, frequently necessitating modifications in nutritional prescriptions. Nursing knowledge and management of the nutritional components that affect erythropoiesis can help ensure optimal patient response to therapy. Case study illustrations of iron deficiency and potassium excess are used to demonstrate potential nursing interventions.
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PMID:Epoetin alfa--focus on nutritional therapy. Case study of the anemic patient. 890 Jun 89


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