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

Twenty-four patients presenting an acute stroke with watershed cerebral infarct on CT scan or MRI were included in this retrospective study. Age was 63 +/- 14 years (mean +/- SD), and sex ratio was 2 men for 1 woman. Main clinical features were: in anterior location, lower limb weakness and frontal syndrome with transcortical motor aphasia in left lesions or spatial dyscalculia in right ones; in posterior location, brachiofacial weakness with constant quadranopsia and hypoesthesia, and Gerstmann syndrome in left lesion. There was no distinctive feature for subcortical and multiple infarcts. In bilateral infarcts, there were one pseudobulbar syndrome, and 2 pseudo brainstem syndromes with neuropsychological signs. Aetiologies were severe carotid artery disease in 14 cases, severe cardiopathy in 6, isolated cerebral angiitis in 1, essential thrombocythemia in 1, protein C deficiency with sickle cell disease in 1, and cholesterol emboli in 1 anatomical case. CBF performed in carotid artery occlusions or tight stenoses showed evidence of haemodynamic changes. Microembolic process can be proposed in the case with cholesterol emboli. Preventive treatment is discussed.
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PMID:Watershed cerebral infarcts: retrospective study of 24 cases. 135

More than a dozen primary hematologic disorders have been associated with ischemic stroke. Inherited deficiencies of antithrombin III, protein C, and protein S have been linked with stroke in case reports; optimal screening requires functional as well as antigenic assays. Antiphospholipid antibodies and lupus anticoagulants are the most frequently identified acquired states associated with ischemic stroke. Polycythemia vera, sickle cell anemia, sickle-C disease, and essential thrombocythemia are the major disorders of formed blood elements causing stroke. Special, step-wise screening for occult prothrombotic entities in stroke patients is recommended for young persons with stroke of uncertain cause, for those with prior venous thrombosis, for those with a family history of unusual thrombosis, and for those with no other explanation for recurrent stroke. Acquired, perhaps transient, abnormalities of platelets, coagulation inhibition, and fibrinolysis may contribute importantly to brain ischemia in synergy with other mechanisms, but at present these remain ill-defined. The contribution of prothrombotic diatheses to stroke is probably underrecognized and warrants further investigation.
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PMID:Hematologic disorders and ischemic stroke. A selective review. 186 63

Since thrombotic phenomena have important roles in the vasoocclusive manifestations in sickle cell disease (SCD), protein C (PC) was determined in 32 children with SCD during steady state and vasoocclusive crisis (VOC) and in controls. Children with SCD during steady state had significantly lower PC levels as compared to controls. During VOC there was marked decrease in PC as compared to levels during steady state, and these levels increased to initial levels or higher with clinical improvement. It is postulated that the decreased levels of PC in SCD are probably secondary to increased consumption as well as decreased production because of altered liver function. This data suggests that decreased levels of PC may increase the risk of thrombosis in these patients.
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PMID:Plasma protein C levels in children with sickle cell disease. 179 64

To investigate the status of the protein C-protein S anticoagulant pathway in sickle cell disease, we measured protein C, total and free protein S, and C4b-binding protein levels in 20 subjects with sickle cell disease (Hb SS or SC). Mean total and free protein S levels were both significantly lower in subjects with sickle cell disease than in normal individuals, but greater reductions were observed for free S. The free protein S level was below the mean -2 SD for normal subjects in 12 subjects with sickle cell disease; the total protein S level was below this level in three subjects. Mean C4b-binding protein levels were normal in subjects with sickle cell disease, both during painful crisis and in the steady state, and no correlation was observed between the levels of C4b-binding protein and free protein S, suggesting that the low free protein S level was not caused by increased levels of C4b-binding protein. Crossed immunoelectrophoresis of plasma samples from eight subjects with sickle cell disease showed marked reductions in free protein S, with normal levels of protein S bound to C4b-binding protein. In contrast to the protein S level, mean protein C activity was normal in subjects with sickle cell disease, both during painful crisis and in the steady state. However, the protein C level was below the mean -2 SD for normal subjects on at least one occasion in four subjects with sickle cell disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Protein S deficiency in sickle cell anemia. 296 24

Although large vessel thrombi are occasionally reported in patients with homozygous sickle cell disease, the role of intravascular coagulation in typical pain crises is controversial. Therefore, we studied 24 sickle cell patients during and between episodes of pain crisis, using several sensitive tests of hemostasis. Fibrinogen was measured by a clotting assay, beta-thromboglobulin (beta-TG) and fibrinopeptide A (FPA) were quantitated by radioimmunoassay, and protein C was determined by absorbing the zymogen from test plasma, activating it with thrombin-thrombomodulin complex, and measuring activity with a selective synthetic substrate. Fibrinogen was elevated in asymptomatic patients (355 +/- 145 mg/dl) but was no different from the value in these same patients during crisis (333 +/- 180 mg/dl, p greater than 0.1). Similarly, beta-TG 136 +/- 52 ng/ml vs 118 +/- 56; FPA 3.7 +/- 4.8 ng/ml vs 5.2 +/- 4.5, and protein C 71 +/- 20% vs 66 +/- 19 showed no important changes during crisis. However, all these values were significantly different from those in age- and sex-matched healthy controls. beta-TG, fibrinogen, and FPA were elevated (p less than 0.001, 0.005, and 0.05, respectively), and protein C was decreased (p less than 0.003). We conclude that while chronic intravascular coagulation is common in patients with sickle cell disease, there is no evidence that the pain crisis per se is a thrombotic event.
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PMID:Is sickle cell crisis a thrombotic event? 378 60

Seventeen parameters of coagulation and fibrinolysis were measured in 33 patients with sickle cell disease; 30 were tested in steady state (SS) and 19 in crisis (Cr). There were 16 patients in both groups. The same parameters were measured in 16 controls of similar ethnic origin (Black controls; BC) and 20 Caucasian controls (CC), all with HbA only. Highly significant differences (P < 0.001) between Black and Caucasian control groups were noted for: fibrinogen, fibrinopeptide-A (FPA), beta-thromboglobulin (beta TG) and D-dimer. Significant differences (P < 0.03) in plasminogen activator inhibitor (PAI) and functional antithrombin III levels were also noted. Results of the sickle cell patients were therefore compared with those of the Black controls. Sickle cell patients in SS had raised v Wf compared with BC, which increased further during Cr (P = 0.001), but showed no significant increase in fibrinogen. Functional protein C was reduced in SS (P = 0.004) but with no further fall in Cr, while free protein S was normal in SS but reduced in Cr (P = 0.02). Total protein S and ATIII were normal in SS and Cr. FPA and beta TG were not significantly raised in SS or Cr compared with BC. There were, however, highly significant increases in D-dimer and thrombin-antithrombin complexes (TAT) in both SS and Cr compared with BC (P < 0.001 for SS and Cr vs BC). Thus significant activation of coagulation with consequent increase in fibrinolysis occurs during both the sickle cell crisis and in the steady state.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Changes in coagulation and fibrinolysis in patients with sickle cell disease compared with healthy black controls. 760 84

Recent studies suggest that increased activity of the coagulation system, measured with sensitive assays for activation markers, may be important in the pathogenesis of vascular occlusion in sickle cell disease (SCD). Since most of these studies were carried out in adult patients and SCD is an inherited disorder with severe morbidity even in childhood, we decided to determine the activity of the coagulation system in children with SCD. In a prospective study markers of thrombin generation as well as coagulation inhibitors were investigated in 16 homozygous SCD patients and 16 age-matched control children. Significantly increased plasma concentrations of the prothrombin fragment F1+2 and of thrombin-antithrombin III (TAT) complexes were found in SCD patients. The levels of protein C activity and total and free protein S were significantly reduced in SCD patients as compared with control values. Plasma AT III levels were not different in the two groups. We conclude that, in children with SCD, evidence of enhanced thrombin generation is present, which may in part be due to reduced levels of the inhibitors proteins C and S. The clinical relevance of this coagulation imbalance has to be demonstrated.
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PMID:Enhanced thrombin generation in children with sickle cell disease. 819 93

Proteins C and S are vitamin K-dependent proteins with an essential anti-coagulant function. Protein C exists in an inactive form and is activated by a thrombin-thrombomodulin complex. Protein S combines with protein C and forms a stoichiometric complex which regulates coagulation in the presence of calcium. As patients with sickle cell disease (SCD) bear a high risk of developing thrombo-embolic disorders, we studied the coagulation derangement in 100 patients and 40 normal age- and sex-matched controls. The patients were clinically assessed and classified into sickle cell homozygotes (Hb SS), Hb S heterozygotes (Hb AS) and double heterozygotes for Hb S/beta 0-thalassaemia based on haematological parameters, red cell indices, Hb A2 and F levels and genetic studies. The proteins C and S were estimated and related to the type of the gene defect. The results showed significantly reduced levels of proteins C and S in SCD patients with the highest prevalence of deficiency in patients with a severe disease and frequent episodes of crisis. However, no significant differences were encountered in the level of proteins C and S in the same patients during the steady state and during episodes of crisis. It was concluded that the lower protein C and S levels in SCD is either due to decreased production or increased consumption though this reduction does not seem to play a role in producing thrombo-embolic disorders.
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PMID:Blood proteins C and S in sickle cell disease. 829 68

In sickle cell disease (SCD), vaso-occlusion is a complex process involving cellular, vascular and humoral factors and possibly thrombotic events. We studied three physiological inhibitors of the coagulation system, antithrombin III (AT III), protein C (PC) and protein S (PS), in three groups of subjects: 27 homozygous patients observed either in crisis or in a steady state, 23 heterozygous patients and 30 healthy subjects. PS study included the measurement of total and free PS antigen, PS activity and C4bBP antigen. In heterozygous subjects the results were similar to those of controls, but in homozygous subjects abnormalities of PS and to a lesser extent PC were observed. Values of PC were extremely variable with 10 cases lower than the normal range (2 SD of the mean) and 17 others within this range. In all cases total PS antigen was slightly reduced (77 +/- 18%, M +/- SD) with a more marked decrease of free antigen (59 +/- 17%) and normal values of C4bBP. Levels of PS activity were greatly reduced and lower than those of free antigen with a mean ratio of PS activity to free antigen of 0.6. These abnormalities were associated with significantly high concentrations of fibrinogen D-dimers. PS deficiency in SCD may be at least partly due to adsorption of free PS to aminophospholipids abnormally expressed on sickle cells membranes, microvesicles and activated platelets, while the discrepancy between PS activity and free antigen could reflect proteolytic inactivation of PS by traces of thrombin.
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PMID:Decreased protein S activity in sickle cell disease. 841 63

Protein C levels were determined in 40 Gabonese children with sickle cell disease, in the steady state and during vasoocclusive crisis. In comparison with 40 healthy controls matched for age and sex, there was a significant decrease in protein C activity in the patients, although no difference was found between protein C levels in the steady state and during crisis.
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PMID:Protein C activity in Gabonese children with sickle cell disease. 890 7


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