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排序方式: 共有270条查询结果,搜索用时 15 毫秒
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Machado RF Barst RJ Yovetich NA Hassell KL Kato GJ Gordeuk VR Gibbs JS Little JA Schraufnagel DE Krishnamurti L Girgis RE Morris CR Rosenzweig EB Badesch DB Lanzkron S Onyekwere O Castro OL Sachdev V Waclawiw MA Woolson R Goldsmith JC Gladwin MT;walk-PHaSST Investigators Patients 《Blood》2011,118(4):855-864
In adults with sickle cell disease (SCD), an increased tricuspid regurgitation velocity (TRV) by Doppler echocardiography is associated with increased morbidity and mortality. Although sildenafil has been shown to improve exercise capacity in patients with pulmonary arterial hypertension, it has not been evaluated in SCD. We therefore sought to determine whether sildenafil could improve exercise capacity in SCD patients with increased TRV and a low exercise capacity. A TRV ≥ 2.7 m/s and a 6-minute walk distance (6MWD) between 150 and 500 m were required for enrollment in this 16-week, double-blind, placebo-controlled sildenafil trial. After 74 of the screened subjects were randomized, the study was stopped early due to a higher percentage of subjects experiencing serious adverse events in the sildenafil arm (45% of sildenafil, 22% of placebo, P = .022). Subject hospitalization for pain was the predominant cause for this difference: 35% with sildenafil compared with 14% with placebo (P = .029). There was no evidence of a treatment effect on 6MWD (placebo-corrected effect -9 m; 95% confidence interval [95% CI] -56-38; P = .703), TRV (P = .503), or N-terminal pro-brain natriuretic peptide (P = .410). Sildenafil appeared to increase hospitalization rates for pain in patients with SCD. This study is registered at www.clinicaltrials.gov as NCT00492531. 相似文献
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Nouraie M Cheng K Niu X Moore-King E Fadojutimi-Akinsi MF Minniti CP Sable C Rana S Dham N Campbell A Ensing G Kato GJ Gladwin MT Castro OL Gordeuk VR 《Haematologica》2011,96(8):1092-1098
Background
Bone changes are common in sickle cell disease, but the pathogenesis is not fully understood. Tartrate-resistant acid phosphatase (TRACP) type 5b is produced by bone-resorbing osteoclasts. In other forms of hemolytic anemia, increased iron stores are associated with osteoporosis. We hypothesized that transfusional iron overload would be associated with increased osteoclast activity in patients with sickle cell disease.Design and Methods
We examined tartrate-resistant acid phosphatase 5b concentrations in patients with sickle cell disease and normal controls of similar age and sex distribution at steady state. Serum tartrate-resistant acid phosphatase 5b concentration was measured using an immunocapture enzyme assay and plasma concentrations of other cytokines were assayed using the Bio-Plex suspension array system. Tricuspid regurgitation velocity, an indirect measure of systolic pulmonary artery pressure, was determined by echocardiography.Results
Tartrate-resistant acid phosphatase 5b concentrations were higher in 58 adults with sickle cell disease than in 22 controls (medians of 4.4 versus 2.4 U/L, respectively; P=0.0001). Among the patients with sickle cell disease, tartrate-resistant acid phosphatase 5b independently correlated with blood urea nitrogen (standardized beta=0.40, P=0.003), interleukin-8 (standardized beta=0.30, P=0.020), and chemokine C-C motif ligand 5 (standardized beta=−0.28, P=0.031) concentrations, but not with serum ferritin concentration. Frequent blood transfusions (>10 units in life time) were not associated with higher tartrate-resistant acid phosphatase 5b levels in multivariate analysis. There were strong correlations among tartrate-resistant acid phosphatase 5b, alkaline phosphatase and tricuspid regurgitation velocity (r>0.35, P<0.001).Conclusions
Patients with sickle cell disease have increased osteoclast activity as reflected by serum tartrate-resistant acid phosphatase 5b concentrations. Our results may support a potential role of inflammation rather than increased iron stores in stimulating osteoclast activity in sickle cell disease. The positive relationships among tartrate-resistant acid phosphatase 5b, alkaline phosphatase and tricuspid regurgitation velocity raise the possibility of a common pathway in the pulmonary and bone complications of sickle cell disease. 相似文献267.
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McLaren CE Barton JC Gordeuk VR Wu L Adams PC Reboussin DM Speechley M Chang H Acton RT Harris EL Ruggiero AM Castro O;Hemochromatosis Iron Overload Screening Study Research Investigators 《American journal of hematology》2007,82(10):898-905
Elevated mean corpuscular volume (MCV) is common in persons with hemochromatosis associated with HFE C282Y homozygosity. We evaluated data from the subset of non-Hispanic white participants in the Hemochromatosis and Iron Overload Screening Study to determine if elevated MCV in C282Y homozygotes is related to this genotype or to serum iron measures. Regression analysis was used to model MCV and Hb from transferrin saturation (TfSat), serum ferritin (SF), mean corpuscular hemoglobin concentration, red blood cell count, age, HFE genotype, Field Center, and presence of liver-related abnormalities in C282Y homozygotes and control subjects without HFE mutations (wt/wt genotype). Mean MCV was higher in C282Y homozygotes than in HFE wt/wt controls (94.4 vs. 89.7 fL in women; 95.3 vs. 91.2 fL in men; P < 0.0001 for both). These differences were largely associated with increased mean TfSat and SF in C282Y homozygotes. Adjusted mean MCV was 92.0 fL (95% confidence interval, 91.1, 92.9) in female C282Y homozygotes and 90.9 fL (90.3, 91.5) in controls. Among women with SF in the reference range 20-200 microg/L, adjusted mean MCV was 92.9 fL, (91.7, 94.2) in C282Y homozygotes, 1.8 fL higher than in controls (P = 0.013). The adjusted mean MCV of male C282Y homozygotes and controls was similar (P = 0.30). Adjusted mean Hb was 0.2 g/dL higher in women with C282Y/C282Y than in controls. Greater mean MCV in C282Y homozygosity reflects increased mean TfSat and mean SF in men and women; an additional effect of genotype on MCV and Hb was detected in women. 相似文献
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Mehdi Nouraie Noel S. Reading Andrew Campbell Caterina P. Minniti Sohail R. Rana Lori Luchtman‐Jones Gregory J. Kato Mark T. Gladwin Oswaldo L. Castro Josef T. Prchal Victor R. Gordeuk 《British journal of haematology》2010,150(2):218-225
The genetic bases of the highly variable degrees of anaemia and haemolysis in persons with Hb SS are not fully known, but several studies have indicated that G6PD deficiency is not a factor. The G6PD202A and G6PD376G alleles and α‐thalassaemia were determined by molecular genetic testing in 261 children and adolescents with Hb SS in a multicentre study. G6PD202A,376G (G6PD A?) was defined as hemizygosity for both alleles in males and homozygosity in females. Among the participants 41% were receiving hydroxycarbamide. The prevalence of G6PD202A,376G was 13·6% in males and 3·3% in females with an overall prevalence of 8·7%. G6PD202A,376G was associated with a 10 g/l decrease in haemoglobin concentration (P = 0·008) but not with increased haemolysis as measured by lactate dehydrogenase, bilirubin, aspartate‐aminotransferase, reticulocyte count or a haemolytic component derived from these markers (P > 0·09). Similar results were found within a sub‐group of children who were not receiving hydroxycarbamide. By comparison, single and double α‐globin deletions were associated with progressively higher haemoglobin concentrations (P = 0·005 for trend), progressively lower values for haemolytic component (P = 0·007), and increased severe pain episodes (P < 0·001). In conclusion, G6PD202A,376G may be associated with lower haemoglobin concentration in sickle cell anaemia by a mechanism other than increased haemolysis. 相似文献