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

Infection is the main factor of morbidity and mortality in children with sickle cell disease (SCD). The objective of this study is to determine it's epidemiologic outline in senegalese children and adolescents with SCD. We retrospectively studied infection data in all the charts of a cohort of 323 patients with SCD (307 SS, 13 SC and 3 s beta + thalassemia) followed at Albert Royer children hospital from january 1991 to december 1997. Serum sampling was systematically made for HIV and antigen HBs serology in all patients we received in the last 3 months (october to december 1997). Patients were aged from 5 months to 22 years (medium age = 8 years). 813 infection episodes were diagnosed, concerning 184 patients (56 per cent). SS patients were more affected (59 per cent) than the others (23 per cent, p = 0.04). ENT and broncho-pulmonary onsets were more frequent but had a generally benign course. Menigitidis, septicemia and osteomyelitis were exclusively diagnosed in SS patients. Their prevalences in this group were respectively: 1.0 per cent, 4.9 per cent and 9.8 per cent. HIV serology was determined in 155 patients, including 41 per cent with blood transfusion antecedents. All tests were negative. HBs antigen was determined in 104 patients and seroprevalence was 7.7 per cent in the whole group and 6.0 per cent in patients with transfusion antecedents and 7.7 per cent for the others. Plasmodium falciparum malaria onset was observed in 9.6 per cent of our patients and there was no case of cerebral malaria. Infection was involved in 9 of the 11 cases of death. Then infection constitute the major problem in children and adolescents with SCD in Dakar. However prevalences of severe onsets are comparable to data in Europe despite our poor follow up conditions. Senegal haplotype may lead to a good tolerance of SCD. Negative HIV serology and low HBs antigen seroprevalence in transfused patients are attributed to a relatively low level of HIV prevalence in the general population and a good transfusion security in Senegal.
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PMID:[Infections in Senegalese children and adolescents with sickle cell anemia: epidemiological aspects]. 1466 92

Infections constitute a principal cause of morbidity and mortality in sickle cell anemia (SCA). Here we present evidence to suggest that a polymorphism (G-463A MPO) in the gene encoding the myeloperoxidase (MPO) enzyme, important for the host defense system, may significantly increase susceptibility to infection in SCA.
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PMID:Association of the G-463A myeloperoxidase polymorphism with infection in sickle cell anemia. 1599 36

Infection of human erythrocytes by the malarial parasite, Plasmodium falciparum, results in complex membrane sorting and signaling events in the mature erythrocyte. These events appear to rely heavily on proteins resident in erythrocyte lipid rafts. Over the past five years, we and others have undertaken a comprehensive characterization of major proteins present in erythrocyte detergent-resistant membrane lipid rafts and determined which of these proteins traffic to the host-derived membrane that bounds the intraerythrocytic parasite. The data suggest that raft association is necessary but not sufficient for vacuolar recruitment, and that there is likely a mechanism of active uptake of a subset of erythrocyte detergent-resistant membrane proteins. Of the ten internalized proteins, few have been evaluated for a role in malarial entry. The beta(2)-adrenergic receptor and heterotrimeric G protein G(s) signaling pathway proteins regulate invasion. The implications of these differences are discussed. In addition, the latter finding indicates that erythrocytes possess important signaling pathways. These signaling cascades may have important influences on in vivo malarial infection, as well as on erythrocyte membrane flexibility and adhesiveness in sickle cell anemia. With respect to malarial infection, host signaling components alone are not sufficient to induce formation of the malarial vacuole. Parasite proteins are likely to have a major role in making the intraerythrocytic environment conducive for vacuole formation. Such interactions should be the focus of future efforts to understand malarial infection of erythrocytes since host- and parasite-targeted interventions are urgently needed to combat this terrible disease.
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PMID:Lipid rafts and malaria parasite infection of erythrocytes. 1661 83

Clinical and hematological characteristics of 14 patients with sickle cell anemia; one heterozygous AS, and 7, with diagnostic of microcytic hypochromic anemia were analyzed. Hemoglobin phenotypes were identified by electrophoresis, fetal hemoglobin was quantificated for alkaline denaturation and the HbA2 for ionic exchange chromatography; -alpha3,7 -thalassemia was detected by mutation identification using polymerase chain reaction (PCR). SS phenotype was confirmed in 10 patients, two were SSF increased, one was SSFincreasedA2increased, and one was ASFincreased (HbF = 2%). The patient diagnosed as AS was SSFincreased (HbF = 21%). AD-patients presented a moderate clinical course of the illness. Five microcytic hypochromic anemia patients were HbAA, one was HbAAA2increased and another HbAAFincreased; those patients present a high hematological and clinical variation. beta-thalassemia was 19%. -alpha3,7-thalassemia was not detected. Infection was most frequent clinical manifestation (respiratory tract infection and intestinal parasitism). These results shows that -alpha3,7-thalassemia are not modulator genetic factors of clinical and hematological manifestations of patients with microcytic hypochromic anemia and sickle cell anemia. We suggest that environmental factors such as respiratory tract infection and intestinal parasitism may be affect the course of illness.
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PMID:[Hematological and clinical profile in sickle cell or thalassemic patients]. 1682 61

Infection and bacteremia are common in sickle cell disease. We hypothesized that, consistent with evidence for the genetic modulation of other disease complications, the risk of developing bacteremia might also be genetically modulated. Accordingly, we studied the association of single nucleotide polymorphisms (SNPs) in candidate genes with the risk of bacteremia in sickle cell anemia. We found significant associations with SNPs in IGF1R and genes of the TGF-beta /BMP pathway (BMP6, TGFBR3, BMPR1A, SMAD6 and SMAD3). We suggest that both IGF1R and the TGF-beta /BMP pathway could play important roles in immune function in sickle cell anemia and their polymorphisms may help identify a "bacteremia-prone" phenotype.
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PMID:Association of polymorphisms of IGF1R and genes in the transforming growth factor- beta /bone morphogenetic protein pathway with bacteremia in sickle cell anemia. 1688 51

Sickle cell anemia is a disease caused by production of abnormal hemoglobin. Infection, acute splenic sequestration crisis, aplastic crises, acute chest syndrome, stroke, cholelithiasis, renal disease and pain are the major complications. Unilateral or bilateral diaphragm paralysis maybe seen following phrenic nerve injury and with a variety of motor-neuron diseases, myelopathies, neuropathies, and myopathies. Prominent right hemi-diaphragma elevation was observed on chest radiograph of a 14 years' old female patient with sickle cell disease. Her medical history yielded neither trauma nor intra-thoracic surgery. She didn't have either motor deficit or sensation disorder on any region of her body. Thorax CT yielded no lesion except the significantly elevated right diaphragm. Her cranial CT showed no lesion, too. Diagnosis of right hemidiaphragm paralysis was confirmed by positive Hitzenberg Sniff test on fluoroscopy. Although several pathophysiologic mechanisms are known to be involved and lead to central neurologic complications in sickle cell disease, involvement of peripheric nerves have not been reported. Here we present a 14 years' old female patient with sickle cell anemia and unilateral diaphragm paralysis, co-existence of which have not been reported so far.
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PMID:Co-existince of sickle cell disease and hemidiaphragm paralysis. 1720 26

In a retrospective review, 3 (3.8%) of 78 patients developed recurrent posterior reversible encephalopathy syndrome. Underlying clinical conditions included sickle cell disease, antibody-positive autoimmune disease, and allogeneic bone marrow transplantation. Infection (bacterial/viral) was suspected or documented in both episodes in all 3 patients. Evidence of endothelial injury (schistocyte formation and increased lactate dehydrogenase) was documented in all patients, and multiple organ dysfunction syndrome developed during the hospital course of all admissions.
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PMID:"Recurrent" posterior reversible encephalopathy syndrome: report of 3 cases--PRES can strike twice! 1725 48

Sickle cell disease results from the presence of abnormal beta globin chains within hemoglobin and may be manifested in anemia, vaso-occlusion, and superimposed infection. The gene that causes sickle cell disease is particularly prevalent in populations of African origin; approximately 8% of African Americans and 40% of the members of some African tribes carry the gene for hemoglobin S. Over time, the disease produces various musculoskeletal abnormalities as a result of chronic anemia; these include marrow hyperplasia, reversion of yellow marrow to red marrow, and, occasionally, extramedullary hematopoiesis. Familiarity with the imaging features of sickle cell disease is important for the diagnosis and management of complications. Ischemia and infarction are common complications that may have long-term effects on the growth of bone; these conditions have characteristic radiographic appearances. Infection may be more difficult to identify. Both infection and infarction may occur in muscle and soft tissue alone, without involving bone. However, osteomyelitis must be diagnosed early and treated immediately to prevent bone destruction and deformity; therefore, care must be taken to achieve an accurate diagnosis by identifying or excluding bone involvement. The clinical and radiographic features of acute osteomyelitis may be particularly difficult to distinguish from those of bone infarction. In that context, magnetic resonance (MR) imaging may be useful. At MR imaging, findings of cortical defects, adjacent fluid collections in soft tissue, and bone marrow enhancement are suggestive of infection.
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PMID:Musculoskeletal manifestations of sickle cell disease. 1762 Apr 64

Erythrocytes lack mitochondria and nuclei, key organelles in the regulation of apoptosis. Until recently, erythrocytes were thus not considered subject to this type of cell death. However, exposure of erythrocytes to the Ca2+ ionophore ionomycin was shown to induce cell shrinkage, cell membrane blebbing and breakdown of phosphatidylserine asymmetry with subsequent phosphatidylserine exposure at the cell surface, all typical features of apoptosis. Further studies revealed the participation of ion channels in the regulation of erythrocyte "apoptosis." Osmotic shock, oxidative stress and energy depletion all activate a Ca2(+)-permeable non-selective cation channel in the erythrocyte cell membrane. The subsequent increase of Ca2+ concentration stimulates a scramblase leading to breakdown of cell membrane phosphatidylserine asymmetry and activates Ca2+ sensitive K+ (Gardos) channels leading to KCl loss and (further) cell shrinkage. Phosphatidylserine exposure and cell shrinkage are blunted in the nominal absence of extracellular Ca2+, in the presence of the cation channel inhibitors amiloride or ethylisopropylamiloride, at increased extracellular K+ or in the presence of the Gardos channel inhibitors clotrimazole or charybdotoxin. Thus, increase of cytosolic Ca2+ and cellular loss of K+ participate in the triggering of erythrocyte scramblase. Nevertheless, phosphatidylserine exposure is not completely abrogated in the nominal absence of Ca2+, pointing to additional Ca2(+)-independent pathways. One of those is activation of sphingomyelinase with subsequent formation of ceramide which in turn leads to stimulation of erythrocyte scramblase. The exposure of phosphatidylserine at the extracellular face of the cell membrane stimulates phagocytes to engulf the apoptotic erythrocytes. Thus, sustained activation of the cation channels eventually leads to clearance of affected erythrocytes from peripheral blood. Erythropoietin inhibits the non-selective cation channel and thus interferes with erythrocyte "apoptosis." Susceptibility to scramblase activation is enhanced in thalassemia, sickle cell disease and glucose-6-phosphate dehydrogenase deficiency. Infection with Plasmodium falciparum leads to activation of the cation channel eventually triggering erythrocyte "apoptosis."
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PMID:Erythrocyte ion channels in regulation of apoptosis. 1872 42

In the paediatric service of the teaching hospital of Brazzaville, 582 files of children hospitalized were studied from January 1995 to December 2003. To determine tuberculosis frequency among sickle cell children and estimate the clinical and paraclinical aspects, a case-control study of tubercular patients with HIV negative serology was carried out by comparing at the same time a cohort of 75 sickle cell patients versus 125 patients without sickle cell disease. The results of these studies are as follows. The main assessment is the high frequency of tuberculosis. In 1995 the tuberculosis rate reaches 8%, in 2003 it was up to 13.6%, and 20.6% in 2000 due to the serious consequences of the recurrent wars between 1993 and 1999. Another cause of that high frequency is the rate of HIV/aids patients with a frequency of 2.5% of hospitalization ranging from 1.6 to 3.2%, among them 35% of the tubercular patients were seropositive. The tuberculosis prevalence was 7.4% among sickle cell patients versus 14.2% among control patients. Infection was more often identified in control patients (51.2%) than in sickle cell patients (24%). 68% of the parents were really poor and 18.5% of the children were evicted from their home by war. The pulmonary localizations were prevailing in groups of patients with sickle cell disease as well as in group of control patients. Pleuritis was observed in 8% of the patients with sickle cell disease versus 16.8% for control patients (P = 0.02). No patient with sickle cell disease had a miliary. Anergia to tuberculin test was reported in 35.8% sickle cell patients versus 10.4% for the control patients (P = 0.001). Tuberculosis prevalence is higher among control patients than in sickle cell patients. The high proportion of clinical and paraclinical data of tuberculosis did not significantly differ from the two groups. Evolution was good for 98% of the patients, 1.4% of them died; 74% of deceased patients were affected by HIV/aids.
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PMID:[Child tuberculosis at the teaching hospital of Brazzaville from 1995 to 2003]. 1895 10


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