Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The chronic severe anemia of patients with beta-thalassemia major stimulates extensive erythropoiesis, which results in circulating nucleated normoblasts. We devised a dual staining flow cytometric procedure in order to analyse the cell cycle and ploidy of these normoblasts. Peripheral blood cells of O blood-group type were first stained with Fluorescein Isothiocyanate (FITC)-conjugated anti-H lectin which labels erythroid cells (RBC and normoblasts) by green fluorescence, and then with propidium iodide (PI) which binds to DNA and thereby labels nucleated cells (leukocytes and normoblasts) by red fluorescence. The leukocytes and normoblasts present in the blood sample of thalassemic patients could be distinguished and "gated" based on their green fluorescence. The PI (red) fluorescence, i.e., the DNA histogram of each population, was thus obtained. The results indicated no statistically significant difference in the PI fluorescence of these two populations. Thus, in spite of the abnormal erythropoiesis in beta-thalassemia, the resultant orthochromatic normoblasts are normal with respect to their DNA content.
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PMID:Flow cytometric analysis of the ploidy of normoblasts in the peripheral blood of patients with beta-thalassemia. 843 76

Spontaneous rosette formation of uninfected erythrocytes around an erythrocyte infected with Plasmodium falciparum is a recently described in vitro phenomenon which is also present in infections with some other malarial species where sequestration of parasite infected erythrocytes is a characteristic. In the present studies, rosetting was established as a P. falciparum virulence factor, the expression of which is modified by a variety of host factors, such as host immunity, ABO blood group and haemoglobin phenotype. The molecules involved in rosetting seem to be distinct from those involved in endothelial cytoadherence, although they are often co-expressed on the same parasitised red cell. Rosette formation was shown not only to be a phenomenon of laboratory-propagated strains, but also to exist in wild clinical isolates from all major malarious areas of the world. In two studies performed in The Gambia, comprising 211 children with uncomplicated or cerebral malaria, a strong association was found between in vitro rosette formation and cerebral malaria, indicating that rosetting plays a role in the pathogenesis of severe P. falciparum disease. Anti-rosetting activity, presumably mediated by antibodies, was found in sera from patients in malaria-endemic areas, and it was demonstrated that such activity was more abundant in individuals with uncomplicated malaria than in those with cerebral disease, suggesting that humoral immunity protects against rosette formation in vivo. It was also demonstrated, by the use of several independent assays, that erythrocytes from individuals with sickle-cell trait, alpha- and beta-thalassaemia trait or with HbE, formed smaller and weaker rosettes than did normal (HbAA) red cells. The results also suggest that microcytosis per se is correlated to impaired rosette formation. Differences in rosetting ability were also seen between red cells of different ABO blood groups, with a diminished rosetting potential in blood group O red cells. Impaired rosette formation may thus contribute to the innate resistance to severe P. falciparum malaria that is known to exist in certain red cell disorders and in individuals of blood group O. Rosette formation was found to be governed by strong adhesive forces, with lectin-like bindings between parasite-derived proteins exposed on the P. falciparum-infected red cell surface, rosettins, and various carbohydrate moieties present on the uninfected erythrocyte. The strongest carbohydrate receptors seem to be contained within the blood group A or B antigens, and the rosettes were abolished by oligosaccharides mimicking these antigens. The binding between infected and uninfected erythrocytes was dependent on divalent cations and was sometimes sensitive to pH.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Erythrocyte rosetting in Plasmodium falciparum malaria--with special reference to the pathogenesis of cerebral malaria. 849 54

A novel probe, a 9-O-acetylated sialic acid binding lectin, namely achatininH (ATNH) has been used for the detection of changes on the cell surface during acute lymphoblastic leukemia (ALL). ATNH does not agglutinate normal human erythrocytes, however it is capable of agglutinating erythrocytes and peripheral blood mononuclear cells (PBMC) of patients suffering from ALL. The differential expression of a key receptor, 9-O-acetylated sialo glyco conjugate (9-O-AcSG), on PBMC was observed using a simple lymphoproliferative assay (LA). The extent of expression of 9-O-AcSG was used as an index to distinguish ALL patients of different clinical stages and assess the probability of relapse. The amount of ATNH needed for maximum stimulation served as a tool to indirectly measure the extent of expression of 9-O-AcSG on PBMC surface. The acetylated sialo glycoconjugate was expressed at a very high concentration during acute phase of the disease. Subsequently it decreased during treatment persisted during maintenance therapy and reappeared with relapse. PBMC of normal human donors required 80 times more ATNH in comparison to the untreated acute phase ALL patients. No cross reactivity was found in non Hodgkin's lymphoma, chronic myelogenous leukemia and thalassaemia patients.
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PMID:O-acetyl sialic acid binding lectin as a probe for detection of subtle change on cell surface induced during acute lymphoblastic leukemia (ALL) and its clinical application. 934 33