Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0002895 (sickle cell disease)
 11,747 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Strokes occurred in 17 of 310 children with homozygous sickle cell disease who were followed from birth, representing an incidence of 7.8% by the age of 14 years. Two children had subarachnoid hemorrhage, one having resolution of symptoms after aneurysm surgery and another dying of a presumed second hemorrhage 14 days later. The remaining 15 strokes were presumed to be cerebral infarction, although autopsy, angiographic, or computed tomographic evidence was available in only 8 children. There were 6 deaths, 2 in the acute event and 4 after recurrence, which occurred in 6 (46%) of 13 patients who survived the initial episode. There were 10 recurrent episodes at a median interval of 9 months after the initial event. Steady-state hematologic data revealed significantly higher leukocyte counts than in control subjects without strokes at age 1 year and in the last study preceding the stroke. The initial stroke coincided with an acutely lowered hemoglobin value in 5 patients (3 aplastic crises, 1 acute splenic sequestration, 1 probable pulmonary sequestration) and with painful crises in another 7 patients. We conclude that a high leukocyte count and an acute decrease of hemoglobin are risk factors for stroke in patients with homozygous sickle cell disease.
 ...
PMID:Stroke in a cohort of patients with homozygous sickle cell disease. 153 80

Regular red blood cell transfusions reduce the rate of recurrent cerebral infarction in sickle cell disease but lead to accumulation of excessive iron. We studied the effect on the prevention of recurrent stroke and the volume of blood transfused of a modified transfusion program in which the pretransfusion percentage of hemoglobin S (HbS) was maintained at 50%, rather than the conventional 30%. Fifteen patients with sickle cell disease and cerebral infarction who had been free of recurrent stroke for at least 4 years during which the pretransfusion HbS was maintained below 30% were assigned to a transfusion program in which the HbS was allowed to increase to 50%. Transfusion regimens included simple transfusion and manual and automated partial exchange transfusion. The duration of follow-up was 14 to 130 months with a median duration of 84 months. None of the 15 patients had a recurrent cerebral infarction during 1,023 patient-months in which the target pretransfusion HbS was 50%. Analysis of this finding, using a binomial distribution, indicates that there is less than a 5% chance that the risk per patient of recurrent stroke in the first year of the modified transfusion program is greater than 18%. One 23-year-old patient had a fatal intraventricular hemorrhage when the HbS was 30% and a 21-year-old patient had a fatal subarachnoid hemorrhage in the 40th week of pregnancy when the HbS was 29%. Blood requirements with simple transfusions decreased by 17% to 48% (mean 31%) when the target pretransfusion HbS level was increased from 30% to 50% (P less than .001). Manual or automated partial exchange transfusions and a target HbS level of 50% in eight patients reduced blood requirements by 33% to 99% (mean 67%) in comparison with simple transfusion and a target HbS level of 30% (P less than .001). This study offers evidence that a target pretransfusion HbS level of 50% affords a continuing high rate of protection against recurrent cerebral infarction in sickle cell disease after 4 years of a conventional transfusion program. Increasing the target HbS level from 30% to 50% provides a major reduction in blood requirements and lowers the rate of iron accumulation.
 ...
PMID:A modified transfusion program for prevention of stroke in sickle cell disease. 155 63

Major organ failure in sickle cell anemia is the direct consequence of the sickle cell evoked vasculopathy. Major organ failure is first clinically apparent as autosplenectomy, then during childhood presents as cerebral infarction and atrophy, and finally culminates in young adulthood as end stage renal failure (glomerulosclerosis), sickle chronic lung disease, intracranial hemorrhage, retinopathy, disabling leg ulcers, and generalized osteonecrosis. The vascular damage begins years before the overt clinical symptoms are apparent with no pain to act as a signal. Organ damage is progressive and irreversible. The rate of progression is genetically controlled from birth. Except for the management of life-threatening infections that are associated with the non-functioning spleen, disease expression has not been altered by therapy. The focus of future clinical investigations must be the prevention of the vasculopathy and tissue damage which is induced by the sickle red cell.
 ...
PMID:Sickle cell anemia and major organ failure. 210 35

Clinical and necropsy findings in 11 patients with sickle cell anemia (SS) indicate that intracranial hemorrhage (IH) is a delayed sequela of the same vasculopathy that causes cerebral infarction during childhood. Evidence of prior cerebral infarction during childhood included hemiparesis, seizures, an episode of coma, or mental retardation. Computerized tomography (CT) scans showed cerebral infarcts with lucent areas and dilated ventricles or cerebral atrophy. CT or magnetic resonance imaging (MRI) scans after the intracranial hemorrhage demonstrated intraventricular or intracerebral hemorrhages. Angiography or autopsy in seven patients showed widespread vascular occlusion and narrowing of arterial vessels. Moyamoya with internal carotid artery occlusion was identified in two cases. At the time of the IH, three patients were being treated with prophylactic transfusion regimens. We hypothesize that the central nervous system vasculopathy progresses over time and that arterial narrowing in both large and small vessels secondary to endothelial hyperplasia is followed by neovascularization and hemorrhage. Recognition of this pattern of delayed intracranial hemorrhage following cerebral infarction should encourage more intensive evaluation aimed at developing rational interventional therapy prior to a terminal intracranial hemorrhage.
 ...
PMID:Delayed intracranial hemorrhage following cerebral infarction in sickle cell anemia. 213 21

Patients with sickle cell anemia experience severe vascular occlusive phenomena including acute pain crisis and cerebral infarction. Obstruction occurs at both the microvascular and the arterial level, and the clinical presentation of vascular events is heterogeneous, suggesting a complex etiology. Interaction between sickle erythrocytes and the endothelium may contribute to vascular occlusion due to alteration of endothelial function. To investigate this hypothesis, human vascular endothelial cells were overlaid with sickle or normal erythrocytes and stimulated to synthesize DNA. The erythrocytes were sedimented onto replicate monolayers by centrifugation for 10 minutes at 17 g to insure contact with the endothelial cells. Incorporation of 3H-thymidine into endothelial cell DNA was markedly inhibited during contact with sickle erythrocytes. This inhibitory effect was enhanced more than twofold when autologous sickle plasma was present during endothelial cell labeling. Normal erythrocytes, with or without autologous plasma, had a modest effect on endothelial cell DNA synthesis. When sickle erythrocytes in autologous sickle plasma were applied to endothelial monolayers for 1 minute, 10 minutes, or 1 hour and then removed, subsequent DNA synthesis by the endothelial cells was inhibited by 30% to 40%. Although adherence of sickle erythrocytes to the endothelial monolayers was observed under these experimental conditions, the effect of sickle erythrocytes on endothelial DNA synthesis occurred in the absence of significant adherence. Hence, human endothelial cell DNA synthesis is partially inhibited by contact with sickle erythrocytes. The inhibitory effect of sickle erythrocytes occurs during a brief (1 minute) contact with the endothelial monolayers, and persists for at least 6 hours of 3H-thymidine labeling. These results indicate that interaction between sickle erythrocytes and the endothelium may result in altered endothelial function. This altered endothelial function may contribute to the development of vascular occlusive phenomena in patients with sickle cell anemia.
 ...
PMID:Sickle erythrocytes inhibit human endothelial cell DNA synthesis. 224 33

We studied 25 patients with sickle cell anemia and cerebral infarction. We classified lesions as to probable mechanism (large versus small vessel disease) based on the CT/MRI appearance of established infarction. Most patients had CT/MRI patterns of major cerebral vessel occlusion (41%) or border-zone (distal insufficiency) infarcts (31%) best explained by large cerebral vessel vasculopathy. Seven of 25 (28%) had either isolated subcortical (12%) or small cortical branch occlusion (16%) consistent with other mechanisms such as small vessel occlusion or embolism. These results suggest that most clinically recognized cerebral infarctions in sickle cell anemia are caused by large vessel disease, but this mechanism may not account for symptoms of cerebral ischemia in all cases.
 ...
PMID:Cerebral infarction in sickle cell anemia: mechanism based on CT and MRI. 338 16

The cause of stroke in a young adult can usually be ascertained with proper workup. One of the most common causes is atherosclerotic cerebrovascular disease, and cigarette smoking is an important risk factor in young adults. Several types of nonatherosclerotic cerebral vasculopathy can also result in premature cerebral infarction; these include cervicocephalic arterial dissection, nonpenetrating traumatic arterial disease, moyamoya disease, fibromuscular dysplasia, vasculitis, and migraine. Cardiac embolism may play a more important role than was previously thought, and hematologic disorders (eg, sickle cell disease, polycythemia rubra vera, coagulation problems) are known to predispose patients to stroke. A careful history of risk factors and a thorough neurologic and cardiovascular examination followed by adequate testing, including angiography, are essential to diagnosis.
 ...
PMID:Diagnosis of stroke in young adults. 356 68

Eleven patients with sickle cell disease and neurological symptoms underwent MRI examination. Cerebral infarcts of two types were found, those in the vascular distribution of the middle cerebral artery and those in the deep white matter. In the patient whose hydration and whose oxygenation of erythrocytes has been treated, MRI offers diagnostic advantages over arteriography and CT.
 ...
PMID:MRI of sickle cell cerebral infarction. 361 18

Sickle cell disease is known to predispose patients to the risk of cerebral infarction. However, only scattered reports exist of the neurological sequelae of the sickle cell trait. Only 8 cases are reported in the English literature, in some of which the sickle cell trait was not documented by hemoglobin electrophoresis. This report describes 2 men, age 35 and 24 years, who developed acute cerebral infarction. Investigation revealed no apparent cause for the lesion other than the sickle cell trait.
 ...
PMID:Cerebral infarction in sickle cell trait. 405 62

We treated two children with sickle cell disease and intracranial hemorrhage. The incidence of intracranial hemorrhage is increased in sickle cell disease, although not as markedly as that of cerebral infarction. Intracranial hemorrhage has a higher mortality, a lower rate of permanent neurologic impairment, and occurs more often in older patients than does cerebral infarction. Intracranial hemorrhage in adults is likely to be an intracerebral hemorrhage or a subarachnoid hemorrhage secondary to an aneurysm. Children, however, are more likely to have subarachnoid hemorrhage without an identifiable aneurysm. We hypothesize that both hemorrhages and infarcts are due to large-vessel cerebral vasculopathy secondary to the abnormal rheologic features of sickled cells.
 ...
PMID:Intracranial hemorrhage in children with sickle cell disease. 406 7


1 2 3 4 5 6 Next >>