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排序方式: 共有416条查询结果,搜索用时 0 毫秒
411.
A Negative Direct Antiglobulin Test with Strong IgG Red Cell Autoantibodies Present in the Serum of a Patient with Autoimmune Haemolytic Anaemia 总被引:1,自引:0,他引:1
M. B. van't Veer P. M. V. van Wieringen I. van Leeuwen M. A. M. Overbeeke A. E. G. KR. von dem Borne C. P. Engelfriet 《British journal of haematology》1981,49(3):383-386
The case is presented of a boy with an autoimmune haemolytic anaemia of 10 years duration. He had a positive direct antiglobulin test with IgG and complement detected on the red cells and with IgG autoantibodies in the serum. During a recent episode of severe haemolysis, the Hb level fell to 3.8 g/dl and the direct antiglobulin test became negative although his autoantibodies still reacted with all the red cells in a panel. The serum reacted more strongly with C- and e-positive cells. The Rh phenotype of the patient was CcDee as it had always been. Possible explanations of the unexpected findings are discussed. 相似文献
412.
Evidence for a pretranslational defect in hereditary and acquired myeloperoxidase deficiency 总被引:1,自引:0,他引:1
Tobler A; Selsted ME; Miller CW; Johnson KR; Novotny MJ; Rovera G; Koeffler HP 《Blood》1989,73(7):1980-1986
413.
414.
Higazi AA; Upson RH; Cohen RL; Manuppello J; Bognacki J; Henkin J; McCrae KR; Kounnas MZ; Strickland DK; Preissner KT; Lawler J; Cines DB 《Blood》1996,88(2):542-551
Binding of urokinase-type plasminogen activator (uPA) to its glycosylphosphatidylinositol-anchored receptor (uPAR) initiates signal transduction, adhesion, and migration in certain cell types. To determine whether some of these activities may be mediated by associations between the uPA/uPAR complex and other cell surface proteins, we studied the binding of complexes composed of recombinant, soluble uPA receptor (suPAR) and single chain uPA (scuPA) to a cell line (LM-TK- fibroblasts) that does not express glycosylphosphatidylinositol (GPI)-anchored proteins to eliminate potential competition by endogenous uPA receptors. scuPA induced the binding of suPAR to LM-TK- cells. Binding of labeled suPAR/scuPA was inhibited by unlabeled complex, but not by scuPA or suPAR added separately, indicating cellular binding sites had been formed that are not present in either component. Binding of the complex was inhibited by low molecular weight uPA (LMW-uPA) indicating exposure of an epitope found normally in the isolated B chain of two chain uPA (tcuPA), but hidden in soluble scuPA. Binding of LMW-uPA was independent of its catalytic site and was associated with retention of its enzymatic activity. Additional cell binding epitopes were generated within suPAR itself by the aminoterminal fragment of scuPA, which itself does not bind to LM-TK- cells. When scuPA bound to suPAR, a binding site for alpha 2-macroglobulin receptor/LDL receptor-related protein (alpha 2 MR/LRP) was lost, while binding sites for cell-associated vitronectin and thrombospondin were induced. In accord with this, the internalization and degradation of cell-associated tcuPA and tcuPA-PAI- 1 complexes proceeded less efficiently in the presence of suPAR. Further, little degradation of suPAR was detected, suggesting that cell- bound complex dissociated during the initial stages of endocytosis. Thus, the interaction of scuPA with its receptor causes multiple functional changes within the complex including the dis-appearance of an epitope in scuPA involved in its clearance from the cell surface and the generation of novel epitopes that promote its binding to proteins involved in cell adhesion and signal transduction. 相似文献
415.
SL Miles RM Niles S Pittock R Vile J Davies JL Winters NE Abu-Yaghi A Grothey M Siddiqui J Kaur L Hartmann KR Kalli L Pease D Kravitz S Markovic JS Pulido 《Retina (Philadelphia, Pa.)》2012,32(9):1959-1966
PURPOSE:: To determine if there is a factor in the serum of patients with bilateral diffuse uveal melanocytic proliferation (BDUMP) that causes melanocytic proliferation. METHODS:: Human melanocytes and melanoma cells were grown and exposed to serum or plasma of patients with BDUMP, other neoplastic conditions, or control media. Preliminary studies using serum were conducted in an unmasked fashion. In addition, IgG-depleted and IgG-enriched plasma was also tested in a similar fashion. Experiments using plasma were conducted triple masked. To show that the proliferation was melanocyte selective, human dermal fibroblasts, keratinocytes, and ovarian cancer cells were treated with plasma of the BDUMP cases or controls, and the effect of this exposure on their proliferation was quantified. RESULTS:: At 72 hours, the serum of BDUMP patients caused statistically significant increased proliferation of normal human melanocytes. Further studies at 6 days demonstrated similar findings. In addition, melanocytes grown in BDUMP serum exhibited a disorganized morphology with foci of multilayered cells. Cultured melanoma cells also showed statistically significant increase in growth in serum from BDUMP patients compared with controls. Masked plasma studies further confirmed these findings and showed that the IgG fraction appeared to contain the melanocyte growth-stimulating factor. The human fibroblasts, keratinocytes, and ovarian cancer cells did not show an increase in growth with the BDUMP plasma treatment. CONCLUSION:: Patients with BDUMP have a factor in the IgG fraction that selectively causes melanocyte proliferation. How it causes proliferation of human melanocytes and melanoma cells needs to be further elucidated. 相似文献
416.
Matthias Antz Katarzyna Berodt Dietmar Bänsch Sabine Ernst KR Julian Chun Kazuhiro Satomi Boris Schmidt Sigrid Boczor Feifan Ouyang Karl-Heinz Kuck 《Clinical research in cardiology》2008,97(2):110-117
Ablation of symptomatic ventricular tachycardia (VT) in patients with coronary artery disease is frequently performed using
the three dimensional mapping system CARTO. In the amplitude map, bipolar potentials of <1.5 mV are considered abnormal and
represent damaged myocardium due to previous infarction. This pathological electrical area can be arrhythmogenic, serving
as the substrate for reentrant VT. The purpose of this study was to correlate the size of the endocardial substrate with the
success of VT catheter ablation. Included in this retrospective analysis were 69 consecutive patients with coronary artery
disease who underwent ablation for symptomatic clinical VT using CARTO. The voltage maps were analyzed and the area with abnormal
bipolar electrograms (<1.5 mV) was determined using geometric approximation models. The area of abnormal electrograms was
divided into three sizes: small (≤15 cm2; 11 patients), medium (16–99 cm2; 50 patients), and large (≥100 cm2; 8 patients). Patient characteristics were not different between the three substrate groups in regard to age, tachycardia
cycle length, or number of radiofrequency applications, however differed significantly between the small, medium and large
group in regard to left ventricular ejection fraction (44 ± 12% vs. 32 ± 9% vs. 21 ± 7%, respectively; P = 0.001). Overall, there was a significant correlation between myocardial infarction locations and endocardial substrate
sizes (P = 0.031), such that 73% of small substrates were found after inferior myocardial infarctions, and 100% of large substrates
after anterior and multiple myocardial infarctions (P = 0.003). After ablation, inducibility of ventricular arrhythmias was more rare in patients with small substrates compared
to patients with medium or large substrates (small substrates: 9%, medium and large substrates: 43%, P = 0.043). Although during follow-up of 25 ± 17 months (1 day to 72 months) there was no significant difference between endocardial
substrate sizes in regard to recurrence rates (small: 27%, medium: 38%, large: 50%, P = 0.588), patients with a small substrate did not have fast VT or ventricular fibrillation (VF), in contrast to 30% and 38%
of patients with medium and large substrates, respectively. We conclude that in patients with coronary artery disease a small
area of low amplitude bipolar potentials (≤15 cm2) was seen more often after inferior myocardial infarction than after anterior and multiple infarctions. After ablation, patients
with small substrates were rarely inducible and showed a more benign course during follow-up (trend towards fewer arrhythmia
recurrences and no fast VT or VF). As a result smaller arrhythmogenic substrates appear to be better amenable to catheter
ablation than larger substrates. 相似文献