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Query: UMLS:C0002895 (sickle cell disease)
 11,747 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Viruses have been shown to cause bone marrow aplasia in animals and have been implicated in bone marrow failure in man; however, until recently, a specific link between human viral infection and bone marrow failure has not been proven. In 1975 Cossart and colleagues found a serum parvovirus-like virus (SPLV, sometimes referred to as B19) in human serum. Antibody to this virus is present in the sera of 30-45% of healthy adults (Y. E. Cossart, P. P. Mortimer, unpublished observations). However, evidence for a direct link came from work by Pattison et al. who found five children with transient aplastic crisis of sickle cell disease and evidence of active infection with SPLV. This association was later confirmed in a large series of children with sickle cell disease and aplastic crisis in Jamaica. We have studied the effects of virus-containing material on haematopoiesis, using in vitro colony-forming assays to look for direct evidence for a role of SPLV in bone marrow aplasia. We show here that SPLV-containing sera inhibit erythropoiesis in culture. Moreover, in a child with hereditary spherocytosis who developed transient aplastic crisis, a strong inhibitory effect of the patient's serum on erythropoiesis correlated with the presence of virus.
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PMID:A human parvovirus-like virus inhibits haematopoietic colony formation in vitro. 683 76

The amount of trapped plasma in the microhematocrit red blood cell column of samples from 25 normal individuals and 102 patients was investigated. The mean value for the normal individuals was 1.53%, and the mean values for the samples from the patient groups ranged from 1.41% to 1.82%. These groups included patients with sickle cell disease, iron deficiency, and hereditary spherocytosis. There was an inverse correlation between trapped plasma and the MCH in the samples from patients with iron-deficiency (MCH less than or equal to 25.0 pg). These findings have relevance to the determination of the PCV and derived red blood cell indices.
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PMID:Trapped plasma in the microhematocrit. 713 20

We have investigated adenylate cyclase in ghosts from normal and pathologic human red blood cells. Basic parameters such as specific activity, apparent Michaelis constant (KMapp), and response to effectors: sodium fluoride (NaF), 5'-guanylyl imidodiphosphate (Gpp (NH)p), isoproterenol, and PGE1 were investigated. Basal and NaF-stimulated activities were measured in ghosts from patients with hereditary spherocytosis, sickle cell disease, and various unidentified hemolytic anemias. Both activities were increased in any of these pathologic conditions as compared with those of normal red blood cells. Normal values were found in patients with hereditary spherocytosis after splenectomy and in patients with heterozygous sickle cell disease. There was a good correlation between the reticulocyte count and adenylate cyclase activity in hereditary spherocytosis and in sickle cell disease with reticulocyte count lower than 10%. The enzyme activity of the first group was about three times that of the second group. There was no correlation at all in sickle cell disease with higher reticulocytosis and in the group of unidentified hemolytic anemias. These results suggest that increased adenylate cyclase activities are not specific of any of these diseases. In the patients with hereditary spherocytosis, the adenylate cyclase activity seems to be essentially related to younger mean age of red blood cell population while in the patients with sickle cell disease and in others with unidentified hemolytic anemias some additional factors might interfere directly with the enzyme and alter its activity.
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PMID:Human red cell membrane adenylate cyclase in normal subjects and patients with hereditary spherocytosis, sickle cell disease and unidentified hemolytic anemias. 743 18

In reflection contrast erythrocytes show characteristic interference lines consisting of alternating maxima and minima. The distance between neighboring interference lines corresponds to a difference in cell thickness of about 113 nm. Some visual and graphic methods for quantitative morphological analysis are described; their application is demonstrated using unstained and stained blood smears of normal individuals and patients with hereditary spherocytosis, sickle cell anemia, and thalassemia.
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PMID:Quantitative morphological analysis of erythrocytes by reflection contrast microscopy. 743 32

2-Butoxyethanol causes hemolysis in rodents but not in humans. 2-Butoxyethanol-induced hemolysis is primarily due to the effect of its metabolite 2-butoxyacetic acid (BAA). 2-Butoxyacetic acid did not cause hemolytic effects when incubated with blood from a limited number of normal individuals. Because 2-butoxyethanol is contained in many consumer products, the possibility that there may be human subpopulations susceptible to hemolysis by BAA was examined. 2-Butoxyacetic acid was incubated with red blood cells from healthy young and older individuals and with red blood cells from patients with hereditary spherocytosis and sickle cell disease. After incubation of red blood cells with or without 2.0 mM BAA for up to 4 h, conditions that readily hemolyzed rat red blood cells, there was no increase in hemolysis or changes in mean cellular volume or morphology. The deformability of erythrocytes treated with BAA was also measured using a nuclepore filtration technique. No changes in deformability due to treatment with BAA were detected. Although BAA is a potent cause of hemolysis in rats, red blood cells in humans, including the elderly and patients with two disorders marked by chronic hemolysis, were not susceptible to BAA-induced hemolysis or loss of deformability.
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PMID:Hemolysis and deformability of erythrocytes exposed to butoxyacetic acid, a metabolite of 2-butoxyethanol: II. Resistance in red blood cells from humans with potential susceptibility. 802 14

Although many RBC rheological properties have been previously described in detail, the biochemical mechanisms leading to premature destruction of red blood cells are less clear. However, several biochemical processes have been suggested as possible mechanisms for membrane structural alterations (e.g., crosslinking of membrane proteins, oxidant damage, binding of cytoplasmic proteins, and altered intracellular ion composition). We have carried out a series of studies aimed at evaluating the effects of calcium-regulated membrane-bound hemoglobin (Hbm) on RBC and derived ghost rheologic behavior. Intracellular calcium was elevated by 10 microM A23187, with cell deformability determined via the Cell Transit Analyzer (CTA). Our results indicate: 1) Linear, positive correlations between Hbm and average RBC rigidity and 2) a marked influence of heterogeneous calcium concentration on both Hbm and rheologic properties for various subpopulation. These findings therefore suggest the importance of hemoglobin-membrane interactions as a determinant of erythrocyte deformability, and may be relevant to RBC aging as well as to diseases such as sickle cell anemia, hereditary spherocytosis and thalassemia.
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PMID:Effects of calcium permeabilization on RBC rheologic behavior. 872 82

Parvovirus B19 is usually associated with an acute, self-limited disease in children. In patients with a congenital hemolytic anemia, infection with this virus can cause an aplastic crisis. We describe such a crisis in an adult with asymptomatic hereditary spherocytosis. The association between acute red blood cell aplasia and infection with parvovirus B19 is well described in patients with hereditary hemolytic anemia, particularly sickle cell anemia. This association has also been described, although less frequently, in patients with other inherited hemolytic diseases, such as hereditary spherocytosis. In children, human parvovirus B19 causes an acute self-limited illness known as erythema infectiosum (fifth disease). In immunocompromised individuals, chronic infections can occur and cause a severe, persistent anemia. In pregnant women, infection can, but usually does not, lead to fetal infection. An infected fetus can have severe anemia, congestive heart failure, generalized edema (fetal hydrops) and even death. Most cases of aplastic crises associated with parvovirus B19 in patients with hereditary spherocytosis have been reported in children and adolescents. In this paper we describe an aplastic crisis in a 28 year old man with asymptomatic hereditary spherocytosis.
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PMID:Aplastic crisis associated with parvovirus B19 in an adult with hereditary spherocytosis. 930 16

Gall stones in children have been commonly described in hereditary spherocytosis and sickle cell anaemia. In North India thalassemia is the commonest haemolytic anaemia. We studied the incidence of gall stones sonographically in children with thalassemia major. Of the 64 multitransfused children with thalassemia major studied (age range 5-20 years) none had symptoms of biliary colic or evidence of gall stones on sonography. The study has demonstrated that patients with thalassemia major are not prone to develop gall stones.
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PMID:Multitransfused children with thalassemia major do not have gallstones. 938 51

In order to investigate the tyrosine phosphorylation of band 3, we performed immunoblotting of intact red cells using anti-phosphotyrosine antibody of 21 patients with sickle cell disorders (11 SS, 5 Sbeta, 5 SC), 7 patients with beta thalassemias (5 beta thal intermedia, 2 deltabeta thal), 10 normal controls, and 1 patient with hereditary spherocytosis. They had not received transfusion for the last 4 months and all were clinically stable. Our results showed an increased tyrosine phosphorylation of two proteins, in the 100 and 80 kD regions, in sickle cell and beta-thalassemic red cells when compared to the normal controls and to the patient with hereditary spherocytosis. Immunoprecipitation of the lysed red cells with anti-band 3 antibody and immunoblotting with anti-phosphotyrosine antibody confirmed that the 100 kD tyrosine phosphorylated protein was band 3. In the sickle cell disease group, the band 3 tyrosine phosphorylation varied from 2- to 10-fold increase compared to control (x +/- SD; SS = 7.8- +/- 2.7-fold; SC = 3.8- +/- 1.3-fold; Sbeta = 5.2- +/- 2.0-fold). It was also higher in the beta-thalassemic group (beta-thal = 4.3- +/- 3.7-fold). There was no significant difference in tyrosine phosphorylation among the various groups tested, except when we compared the phosphorylation in intact red cells of patients with sickle cell anemia and hemoglobinopathy SC (U = 6, P < 0.02). The tyrosine phosphorylation of band 3 was increased in hemoglobinopathies even in the absence of high reticulocyte count. At least two mechanisms might be involved in the increased tyrosine phosphorylation of band 3 in these hemoglobin disorders, probably related to the endogenous reactive oxygen intermediates generated by the abnormal erythrocyte: an inhibition of protein tyrosine phosphatase activity or an activation of the protein tyrosine kinase p72syk.
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PMID:Increased tyrosine phosphorylation of band 3 in hemoglobinopathies. 966 75

Splenectomy in childhood usually is required for hematologic disorders such as hereditary spherocytosis, immune thrombocytopenic purpura, or sickle cell disease. The laparoscopic approach for splenectomy in children has been developed and advanced over the past 5 years. New techniques and equipment allow the procedure to be performed safely and effectively. This article details the technique and reports the results of 63 infants, children, and adolescents who underwent laparoscopic splenectomy for hematologic disorders. Although operating times were longer than for open splenectomy, the narcotic requirement was less and length of stay was shorter.
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PMID:Laparoscopic splenectomy. 984 Sep


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