Gene/Protein Disease Symptom Drug Enzyme Compound
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 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sickle cell disease (SCD) patients are prone to develop complications that include stroke, acute chest syndrome, and other crises. Some of these complications require chronic transfusion therapy or red cell exchange (RCE), either for therapeutic or prophylactic reasons. Due to a discrepancy of red cell antigens between African Americans and Caucasians (majority blood donors), the incidence of alloantibody formation is very high, which makes it difficult to find compatible red cell units, especially for urgent RCE. Some of the above conditions require immediate oxygen delivery to the tissues. Thus, SCD patients undergoing RCE should receive red blood cells with special attributes that include matching for Rh and Kell blood group antigens; RBCs should be fresh in order to provide (1) immediate oxygen delivery and (2) longer surviving cells to reduce the interval between RCE. Also, these units should be pre-storage leukoreduced to prevent febrile non-hemolytic reactions and screened for sickle cell traits to avoid transfusing red cells containing HbS. This requires a concerted effort between the apheresis unit, the local blood bank, and the central blood supplier.
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PMID:Blood bank issues associated with red cell exchanges in sickle cell disease. 1717 80

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

The Cooperative Study of Sickle Cell Disease reported that dactylitis, severe anemia, and leukocytosis in very young children with sickle cell disease (SCD) increased the risk of later adverse outcomes, including death, stroke, frequent pain, and recurrent acute chest syndrome. This model has not been validated in other cohorts. We evaluated its performance in the Dallas Newborn Cohort, a newborn inception cohort of children with SCD. We studied 168 children (55% male, 97% sickle cell anemia) with a mean follow-up of 7.1 years who provided 1188 patient-years of observation. Of the 23 (13.7%) subjects who experienced adverse events, 2 (1.2%) died, 14 (8.3%) had a stroke, 4 (2.4%) had frequent pain, and 3 (1.8%) had recurrent acute chest syndrome. No relationship existed between early clinical predictors and later adverse outcomes, with the possible exception of leukocyte count. Most subjects who experienced adverse events were predicted to be at low risk for those events. No subject who was predicted to be at high risk actually experienced an adverse outcome. The sensitivity of the model did not rise above 20% until specificity fell below 60%. We suggest that this model not be used as a criterion to initiate early interventions for SCD.
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PMID:Prediction of adverse outcomes in children with sickle cell anemia: a study of the Dallas Newborn Cohort. 1790 76

beta-Thalassemia major and sickle cell disease (SCD) are among the most common hereditary disorders worldwide. The supportive treatment of beta-thalassemia major requires chronic, life-long RBC transfusions, which cause progressive iron overload and the potential for impaired endocrine, cardiac and hepatic function. The phenotype of thalassemia major is reliably predicted by its genotype. In contrast, SCD is a variable genetic disease caused by a single amino acid substitution in the beta chain of human hemoglobin. Manifestations of SCD are quite varied, but generally result from the tendency of Hb S to irreversibly polymerize under physiologic stressors such as hypoxemia and acidosis. The polymerization causes perturbations in the erythrocyte integrity that promote vaso-occlusion and which manifest as clinical events such as severe painful episodes, acute chest syndrome, splenic infarction, stroke and avascular necrosis of target joints. The only cure proved for these disorders is correction of the genetic defect by allogeneic hematopoietic cell transplantation (HCT). We illustrate the pediatric experience of HCT for hemoglobinopathies and discuss how these results affect future therapeutic decisions in children who inherit these disorders.
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PMID:Hematopoietic cell transplantation for thalassemia and sickle cell disease: past, present and future. 1805 30

Asthma is a common comorbidity in sickle cell disease (SCD) with a reported prevalence of 30-70%. The high frequency of asthma in this population cannot be attributed to genetic predisposition alone, and likely reflects in part, the contribution of overlapping mechanisms shared between these otherwise distinct disorders. There is accumulating evidence that dysregulated arginine metabolism and in particular, elevated arginase activity contributes to pulmonary complications in SCD. Derangements of arginine metabolism are also emerging as newly appreciated mechanism in both asthma and pulmonary hypertension independent of SCD. Patients with SCD may potentially be at risk for an asthma-like condition triggered or worsened by hemolysis-driven release of erythrocyte arginase and low nitric oxide bioavailability, in addition to classic familial asthma. Mechanisms that contributed to asthma are complex and multifactorial, influenced by genetic polymorphisms as well as environmental and infectious triggers. Given the association of asthma with inflammation, oxidative stress and hypoxemia, factors known to contribute to a vasculopathy in SCD, and the consequences of these factors on sickle erythrocytes, comorbid asthma would likely contribute to a vicious cycle of sickling and subsequent complications of SCD. Indeed a growing body of evidence documents what should come as no surprise: Asthma in SCD is associated with acute chest syndrome, stroke, pulmonary hypertension, and early mortality, and should therefore be aggressively managed based on established National Institutes of Health Guidelines for asthma management. Barriers to appropriate asthma management in SCD are discussed as well as strategies to overcome these obstacles in order to provide optimal care.
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PMID:Asthma management: reinventing the wheel in sickle cell disease. 1922 84

Homozygous, sickle-cell disease (SCD) is responsible for acute complication, especially anaemic crisis and special situation such as acute chest syndrome, stroke and acute priapism. Pregnancy sickle-cell disease presents high risk for the mother and the fetus. In these indications, blood transfusion is the main therapy aiming to reduce anaemia in order to restore hemoglobin's rate or to increase normal Hb proportion. This study aims to assess the short-term efficiency of the red cell transfusion in SCD homozygous form. One hundred and twelve homozygous sickle-cell patients were enrolled in this prospective study: 59 females and 53 males, median age is 21,8 years (extremes: 2 and 45 years). These patients are mostly with very low income. Two groups of patients are included in this study. In the first group, patients present acute anemia crisis caused by infections disease (malaria, bacterial infections). In the second group (20 cases), SCD patients have particularly situations: pregnancy (10 cases); stroke (six cases); cardiac failure (two cases) and priapism (two cases). Transfusion treatment in first group is simple regimen. Transfusion of EC increased median Hb level at 2,9 g/dl (extremes: 1,1 and 4,7). In the second group of patients, 16 cases were transfused by manual partial exchange (1-3) and four patients received simple regimen of transfusion. Median Hb level was 3,1g/dl (extremes: 2,4-4,9 g/dl). HbS percentage reduction was after PTE between -30 and -66,8% (median: -52,6%). According to our diagnostic possibilities (blood serologic test), we have not found any contamination by HIV, HBV and HCV (virus).
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PMID:[Blood transfusion assessment to 112 homozygous sickle-cell disease patients in university hospital of Brazzaville]. 1936 4

Sickle cell trait occurs in approximately 300 million people worldwide, with the highest prevalence of approximately 30% to 40% in sub-Saharan Africa. Long considered a benign carrier state with relative protection against severe malaria, sickle cell trait occasionally can be associated with significant morbidity and mortality. Sickle cell trait is exclusively associated with rare but often fatal renal medullary cancer. Current cumulative evidence is convincing for associations with hematuria, renal papillary necrosis, hyposthenuria, splenic infarction, exertional rhabdomyolysis, and exercise-related sudden death. Sickle cell trait is probably associated with complicated hyphema, venous thromboembolic events, fetal loss, neonatal deaths, and preeclampsia, and possibly associated with acute chest syndrome, asymptomatic bacteriuria, and anemia in pregnancy. There is insufficient evidence to suggest an independent association with retinopathy, cholelithiasis, priapism, leg ulcers, liver necrosis, avascular necrosis of the femoral head, and stroke. Despite these associations, the average life span of individuals with sickle cell trait is similar to that of the general population. Nonetheless, given the large number of people with sickle cell trait, it is important that physicians be aware of these associations.
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PMID:Complications associated with sickle cell trait: a brief narrative review. 1939 83

Low steady state haemoglobin oxygen saturation in patients with sickle cell anaemia has been associated with the degree of anaemia and haemolysis. How much pulmonary dysfunction contributes to low saturation is not clear. In a prospective study of children and adolescents with sickle cell disease aged 3-20 years at steady state and matched controls, 52% of 391 patients versus 24% of 63 controls had steady state oxygen saturation <99% (P < 0.0001), 9% of patients versus no controls had saturation <95% (P = 0.008) and 8% of patients versus no controls had exercise-induced reduction in saturation > or =3%. Decreasing haemoglobin concentration (P < or = 0.001) and increasing haemolysis (P < or = 0.003) but not pulmonary function tests were independent predictors of both lower steady-state saturation and exercise-induced reduction in saturation. Neither history of stroke nor history of acute chest syndrome was significantly associated with lower steady-state oxygen saturation or exercise-induced reduction in saturation. Tricuspid regurgitation velocity was higher in patients with lower steady state haemoglobin oxygen saturation (P = 0.003) and with greater decline in oxygen saturation during the six-minute walk (P = 0.022). In conclusion, lower haemoglobin oxygen saturation is independently associated with increasing degrees of anaemia and haemolysis but not pulmonary function abnormalities among children and adolescents with sickle cell disease.
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PMID:Prospective evaluation of haemoglobin oxygen saturation at rest and after exercise in paediatric sickle cell disease patients. 1969 21

Pulmonary hypertension (PH) is associated with adverse outcomes in adults with sickle-cell disease (SCD), but its importance in children is less clear. The aim of this study was to define the incidence and causes of PH in pediatric patients with SCD. Children with SCD (n = 310) and matched controls (n = 54) were prospectively enrolled under basal conditions. Participants underwent echocardiography, pulse oximetry, 6-minute walk tests, and hematologic testing. Echocardiographic measures were compared between patients with SCD and control subjects before and after adjusting for hemoglobin. Correlations of echocardiographic and clinical parameters were determined. Tricuspid regurgitation velocity (TRV) was elevated compared to controls (2.28 vs 2.10 m/s, p <0.0001). Increased TRV was associated with left ventricular diastolic diameter, hemoglobin, and estimated left atrial pressure. TRV remained elevated when controlling for left ventricular diameter and left atrial pressure. Echocardiographically derived pulmonary resistance was not significantly different between patients with SCD and controls, although it was elevated in the SCD subgroup with elevated TRV. When controlling for hemoglobin, TRV was no longer statistically different, but pulmonary insufficiency velocity, septal wall thickness, and estimated pulmonary resistance were statistically higher. TRV, pulmonary insufficiency end-diastolic velocity, and markers of increased cardiac output were correlated with indicators of adverse functional status, including history of acute chest syndrome, stroke, transfusions, and 6-minute walk distance. In conclusion, children with SCD had mildly increased TRV that was correlated with increased cardiac output and left ventricular filling pressures. Hemoglobin-adjusted analysis also suggested a contribution of primary vascular changes.
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PMID:Prospective echocardiography assessment of pulmonary hypertension and its potential etiologies in children with sickle cell disease. 1969 50

Sickle cell disease (SCD) is a genetically inherited condition caused by a point mutation in the beta globin gene. This results in the production of the abnormal hemoglobin, sickle hemoglobin (HbS). Hydroxycarbamide, is an antimetabolite/cytotoxic which works by inhibiting ribonucleotide reductase, blocking the synthesis of DNA and arresting cells in the S phase. In sickle cell anemia, it promotes fetal hemoglobin (HbF) synthesis, improves red cell hydration, decreases neutrophil and platelet count, modifies red cell endothelial cell interactions and acts as a nitric oxide donor. Trials have shown the clinical benefit of hydroxycarbamide in a subpopulation of adult patients with SCD, with a 44% reduction in the median annual rate of painful crises, a decrease in the incidence of acute chest syndrome and an estimated 40% reduction in overall mortality over a 9-year observational period. Its use in pediatrics has also been well established; trials have shown it is well tolerated and does not impair growth or development. In addition it decreases the number and duration of hospital attendences. A number of emerging uses of hydroxycarbamide currently are being investigated, such as stroke prevention.
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PMID:Role of hydroxycarbamide in prevention of complications in patients with sickle cell disease. 1981 73


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