Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A lipoxygenase has been purified from rabbit reticulocyte-rich anaemic blood cells. It possesses a molecular weight of 78 000 and an isoelectric point of 5.5 and contains 5% neutral sugars and two iron atoms per enzyme molecule. The lipoxygenase has proved to be identical with the inhibitors of respiratory proteins described formerly. The actions of the lipoxygenase on linoleic acid, phospholipids, mitochondrial and erythrocyte membranes and electron transfer particles were studied. A special feature of the reticulocyte lipoxygenase is the suicidal character of its action on lipids. With electron transfer particles the reticulocyte lipoxygenase causes a loss of acid-labile sulfur which accompanies respiratory inhibition; the strong respiratory inhibition is not exerted by soybean lipoxygenase. The reticulocyte lipoxygenase acts preferably on mitochondrial membranes as compared with cell membranes of the erythrocyte; erythrocyte cytosol moderates the action on mitochondrial membranes. Furthermore, the lipoxygenase reaction can concomitantly and irreversibly inactivate sulfhydryl enzymes as demonstrated with muscle glyceraldehyde-3-phosphate dehydrogenase. The occurrence of the lipoxygenase here described is restricted to reticulocytes; very low amounts were observed in bone marrow and no lipoxygenase was detectable in normal blood. During the course of an experimental anaemia the lipoxygenase is produced owing to superinduction in large amounts, which may persist for a long time since they escape inactivation. Preliminary evidence was obtained for the occurrence of other lipoxygenases in tissues of lung, spleen, kidney and also epithelial tumours.
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PMID:The lipoxygenase of reticulocytes. Purification, characterization and biological dynamics of the lipoxygenase; its identity with the respiratory inhibitors of the reticulocyte. 11 25

Hypophosphatemia was induced in 2 cows by reducing phosphorus content in their feed after parturition. Serum inorganic phosphorus (Pi) values decreased to 1 mg/dl within 10 days after parturition; and RBC adenosine 5'-triphosphate (ATP) and reduced glutathione values decreased to 50 and 70% of baseline values, respectively. Methemoglobin concentration was moderately higher than normal. These changes preceded the onset of hemolysis, and anemia progressed with decreases in PCV, hemoglobin concentration, and RBC counts. Serum Pi resumed its normal value when anemia was most severe. This RBC disorder was confirmed to be characteristic of hemolytic anemia in cows resulting from hypophosphatemia. The RBC glycolytic intermediates, total triose phosphate (combined glyceraldehyde-3-phosphate and dihydroxyacetone phosphate content) and fructose-1,6-diphosphate, greatly increased in vivo and in vitro with decreases in serum or plasma Pi and RBC ATP. From our results, we concluded that inadequate Pi in the plasma impairs the function and viability of RBC by hindering the production of ATP via disturbance of reactions at the glyceraldehyde-3-phosphate dehydrogenase step.
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PMID:Hemolytic anemia and red blood cell metabolic disorder attributable to low phosphorus intake in cows. 293 26

Various disorders of the red cell skeleton and membrane have been described in hereditary spherocytosis. To elucidate which aberrations could be used for identification of HS patients in a Danish population, we examined ghosts from 17 HS patients and 20 normals by use of SDS-gel scanning, native spectrin extraction, and limited tryptic digestion. Compared to normals, HS patients had significantly lowered alpha-spectrin (p < 0.004), protein 4.2 (p < 0.025), and actin (p < 0.05), and significantly increased anion-transporter (p < 3 x 10(-6)) and glyceraldehyde-3-phosphate dehydrogenase (G3PD, p < 0.04). Sixteen out of 17 HS patients could be identified by aberrations of the anion-transporter or protein 4.2 outside a 95% confidence interval for normals. Extraction of native spectrin and limited tryptic digest showed no difference between normals and HS patients. RBC separated into young and old fractions were used to examine the occurrence of protein aberrations associated with RBC age. Young RBC contained more G3PD (35%) and less protein 4.1 (6.5%) and actin (8.7%) than old. In male HS patients an increased G3PD content showed a linear correlation (p < 0.001) with a low concentration of blood haemoglobin. We conclude that aberrations of G3PD, and possibly protein 4.1, and actin, are associated with anaemia in HS. Increased anion-transporter or lowered protein 4.2 may be useful for diagnosis of HS, and were inherited in five out of six families where two generations were available.
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PMID:Hereditary spherocytosis: diagnostic and anaemia-associated aberrations of ghost proteins. 819 7

Red blood cell (RBC) protein 4.2 deficiency is often associated with a moderate nonimmune hemolytic anemia, splenomegaly, and osmotically fragile RBCs resembling, but not identical to, hereditary spherocytosis (HS). In the Japanese type of protein 4.2 deficiency (protein 4.2Nippon), the anemia is associated with a point mutation in the protein 4.2 cDNA. In this report, we describe a patient with moderate and apparently episodic nonimmune hemolytic anemia with splenomegaly, spherocytosis, osmotically fragile RBCs, reduced whole cell deformability, and abnormally dense cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the proposita's RBC membrane proteins showed an 88% deficiency of protein 4.2 and a 30% deficiency of glyceraldehyde-3-phosphate dehydrogenase (band 6). Structural and molecular analyses of the proposita's protein 4.2 were normal. In contrast, limited tryptic digestion of the proposita's band 3 showed a homozygous abnormality in the cytoplasmic domain. Analysis of the pedigree disclosed six members who were heterozygotes for the band 3 structural abnormality and one member who was a normal homozygote. Direct sequence analysis of the abnormal band 3 tryptic peptide suggested that the structural abnormality resided at or near residue 40. Sequence analysis of the proposita's band 3 cDNA showed a 232G-->A mutation resulting in a 40glutamic acid-->lysine substitution (band 3Montefiore). Allele-specific oligonucleotide hybridization was used to probe for the mutation in the pedigree, showing that the proposita was homozygous, and the pedigree members who were heterozygous for the band 3 structural abnormality were also heterozygous for the band 3Montefiore mutation. The band 3Montefiore mutation was absent in 26 chromosomes from race-matched controls and in one pedigree member who did not express the band 3 structural abnormality. In coincidence with splenectomy, the proposita's anemia was largely corrected along with the disappearance of most spherocytes and considerable improvements of RBC osmotic fragility, whole cell deformability, and cell density. We conclude that this hereditary hemolytic anemia is associated with the homozygous state for band 3Montefiore (40glutamic acid-->lysine) and a decreased RBC membrane content of protein 4.2. We speculate that band 3 structural abnormalities can result in defective interactions with protein 4.2 and band 6, and in particular, that the region of band 3 containing 40glutamic acid is involved directly or indirectly in interactions with these proteins.
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PMID:Human erythrocyte protein 4.2 deficiency associated with hemolytic anemia and a homozygous 40glutamic acid-->lysine substitution in the cytoplasmic domain of band 3 (band 3Montefiore). 847 74

Two canine haemoplasma species have been recognised to date; Mycoplasma haemocanis (Mhc), which has been associated with anaemia in splenectomised or immunocompromised dogs, and "Candidatus Mycoplasma haematoparvum" (CMhp), recently described in an anaemic splenectomised dog undergoing chemotherapy. The study aim was to develop quantitative real-time PCR assays (qPCRs) incorporating an endogenous internal control to detect Mhc and CMhp and to apply these assays to DNA samples extracted from canine blood collected in Northern Tanzania (n=100) and from dogs presented to a Trinidadian veterinary hospital (n=185). QPCRs specific for Mhc and CMhp were designed using 16S rRNA gene sequence data, and each was duplexed with an assay specific for canine glyceraldehyde-3-phosphate dehydrogenase (GAPDH). The assays detected < or =10 copies of a sequence-specific haemoplasma plasmid per reaction and neither assay showed cross-reactivity with 10(6) copies of the sequence-specific plasmid from the non-target canine haemoplasma species. Nineteen of the 100 Tanzanian samples (19%) were positive for Mhc alone and one (1%) was dually infected. One Trinidadian sample was negative for canine GAPDH DNA and was excluded from the study. Of the 184 remaining Trinidadian samples, nine (4.9%) were positive for Mhc alone, five (2.7%) for CMhp alone, and two (1.1%) dually infected. This is the first report of canine haemoplasma qPCR assays that use an internal control to confirm the presence of amplifiable sample DNA, and their application to prevalence studies. Mhc was the most commonly detected canine haemoplasma species.
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PMID:Development and use of real-time PCR to detect and quantify Mycoplasma haemocanis and "Candidatus Mycoplasma haematoparvum" in dogs. 1964 27

Two hemoplasma species are known in dogs: Mycoplasma haemocanis (Mhc) and 'Candidatus Mycoplasma haematoparvum' (CMhp). Although their transmission routes are poorly understood, Rhipicephalus sanguineus has been suggested as a potential tick vector. The aim of the present study was to assess the prevalence, risk factors, and clinical importance of canine hemoplasmas in countries with a Mediterranean climate where R. sanguineus is highly prevalent using TaqMan real-time PCR, and to molecularly characterize the identified isolates. DNA (canine glyceraldehyde-3-phosphate dehydrogenase) was successfully amplified from all samples collected from 850 dogs in Italy, Spain, and Portugal, and 82 (9.6%) were PCR-positive for canine hemoplasmas (43 Mhc, 34 CMhp and 5 co-infected). The hemoplasma sample prevalence was significantly higher in Portugal (40%) than in Italy (9.5%) and Spain (2.5%). Risk factors for infection included living in kennels, young age, crossbreeding, and mange infection. No association was found with anemia. Phylogenetic analyses of the 16S rRNA and RNase P genes revealed >99% identity to other European isolates. In conclusion, canine hemoplasma infections were readily encountered in Mediterranean countries. The climate and living conditions seemed to influence canine hemoplasma prevalence. The clinical importance of canine hemoplasma infections appeared to be low, but the infection stage of the presented dogs was unknown.
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PMID:Prevalence and geographical distribution of canine hemotropic mycoplasma infections in Mediterranean countries and analysis of risk factors for infection. 1993 20

Erythropoietin (Epo) is the primary hormone that stimulates erythroid proliferation and differentiation through its cell surface receptor (EpoR) on erythroid progenitor cells. Previous studies have suggested that the bone marrow plays an important role in Epo's elimination. The changes in the EpoR mRNA levels and Epo's clearance in the bone marrow of 11 newborn lambs were studied to elucidate the role of EpoR in Epo's clearance under anemic conditions. Epo mRNA levels were measured by real-time polymerase chain reaction, and relative expression of EpoR was calculated by using the comparative CT method. The glyceraldehyde-3-phosphate dehydrogenase housekeeping gene was chosen as a control gene for the calculations. All lambs showed significant increase in bone marrow EpoR mRNA levels after phlebotomy-induced anemia. Epo's clearance determined from simultaneous pharmacokinetic studies with 125I-recombinant human Epo showed a significant increase after phlebotomy-induced anemia that was similar to the increase in EpoR. By day 28 after phlebotomy, EpoR mRNA levels and Epo clearance had returned toward baseline. These results indicate that the changes in Epo's clearance are not caused by body growth but result from significant changes in the pool of EpoR. A linear mixed-effect model was used to evaluate the quantitative relationship between EpoR and Epo's clearance. This analysis demonstrated a highly significant positive linear correlation between EpoR and Epo clearance. Together, these findings provide strong evidence that receptor-mediated Epo clearance is an important route for Epo's elimination.
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PMID:Evidence of receptor-mediated elimination of erythropoietin by analysis of erythropoietin receptor mRNA expression in bone marrow and erythropoietin clearance during anemia. 2010 88