Publications by authors named "Ambrose J"

This study reports the association of elevated serum lipoprotein(a) levels with angiographically extensive coronary disease and the presence of totally occluded coronary arteries, as well as the association of elevated lipoprotein(a) with unstable angina. These results support the role of lipoprotein(a) in the human atherothrombotic process.

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To evaluate the role of angiotensin II (AII) on diastolic function during post-myocardial infarction (MI) ventricular remodeling, coronary ligation or sham operation was performed in male Sprague-Dawley rats. Experimental animals were maintained on either irbesartan, a selective AT1-receptor antagonist, or no treatment. Measurement of cardiac hypertrophy, diastolic function, and sarcoendoplasmic reticulum adenosine triphosphatase (ATPase; SERCA) and phospholamban (PLB) gene expression was assessed at 6 weeks after MI.

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Objectives: The purpose of this study was the investigation of the in vivo role of lipoprotein(a) [Lp(a)] and inflammatory infiltrates in the human coronary atherosclerotic plaque and their correlation with the clinical syndrome of presentation.

Background: Lipoprotein(a) is an atherogenic and thrombogenic lipoprotein, and has been implicated in the pathogenesis of acute coronary syndromes. Lipoprotein(a) induces monocyte chemoattraction and smooth muscle cell activation in vitro.

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Objectives: This study evaluated the clinical safety and long-term results of rotational atherectomy (RA) followed by low-pressure balloon dilatation (percutaneous transluminal coronary angioplasty [PTCA]) for the treatment of in-stent restenosis (ISR).

Background: In-stent restenosis is associated with a high incidence of recurrence after interventional treatment. Because ISR is due to neointimal hyperplasia, rotational ablation may be a more effective treatment than PTCA.

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Abciximab (c7E3 Fab, ReoPro), a platelet glycoprotein (GP) IIb/IIIa inhibitor, decreases acute ischemic complications after percutaneous coronary interventions. Recently, abciximab was shown to decrease thrombin generation in vitro in a static system. To assess whether abciximab can decrease fibrin formation in blood from patients, we quantified both platelet thrombi and fibrin deposition by using an ex vivo flow chamber model.

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Objective: We sought to determine whether a prolonged QRS-interval duration is associated with decreased left ventricular (LV) systolic function.

Background: The 12-lead electrocardiogram (ECG) is a routine test for suspected cardiac disease. Although several scoring systems have been devised to estimate LV systolic function, no studies have examined the direct relationship between QRS duration alone and LV systolic function.

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Balloon angioplasty (percutaneous transluminal coronary angioplasty, PTCA) is an established common strategy in the treatment of acute myocardial infarction (MI) with high success rates but a 5-10% incidence of reclosure/reinfarction due to thrombus and/or intimal flaps. Directional coronary atherectomy (DCA) by removing plaque/thrombus and achieving larger postprocedural luminal diameter may further decrease the incidence of reclosure/reinfarction, with a resultant better in-hospital outcome in this setting. We analyzed the clinical, procedural and in-hospital outcome of patients who underwent DCA or PTCA within 48 h of MI.

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Peroneal nerve palsy of nontraumatic origin is extremely rare. We report a case of peroneal nerve palsy that was not attributable to causes previously described in the literature.

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One hundred four patients presenting with acute myocardial infarction < 24 hours after onset were randomized to 2 groups: group I (n = 52) was treated with balloon angioplasty followed electively with Gianturco Roubin II stents, and group II was treated with conventional balloon angioplasty alone (n = 52). All lesions were suitable for stenting. Baseline clinical, demographic, and angiographic characteristics were similar in the 2 groups.

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The ability to achieve rapid and sustained reperfusion in cases of acute MI with an interventional approach constitutes a true revolution in the practice of cardiology. This article discusses those interventions.

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We investigated the clinical and angiographic risk profile of slow flow during rotational atherectomy. Lesion length, angina at rest, and use of beta blockers correlated independently with slow flow in the univariate as well as in the multivariate analysis.

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OBJECTIVE: To investigate the relationships between coronary atherosclerotic plaque injury, lesion morphology, and activation of the coagulation cascade. BACKGROUND: Balloon angioplasty of coronary lesions may result in intracoronary thrombin generation and activity. It is unknown whether the angiographic morphology of the lesion prior to intervention, an indicator of the presence of thrombus in the lesion, is a determinant of the degree of coagulation cascade activation.

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In this prospective randomized study of the use of the Terumo glide wire compared with the standard straight wire for crossing of severely stenotic aortic valves, the glide wire was shown to significantly decrease the fluoroscopy time of the procedure and to lower by 3.4 times the need for crossover to the alternative technique.

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The evolution and progression of thrombus and dissection after percutaneous transluminal coronary angioplasty (PTCA) are unknown. As part of the protocol of the Thrombolysis and Angioplasty in Unstable Angina (TAUSA) trial, 1 and 15 minutes post-PTCA angiograms were routinely performed and evaluated by the core laboratory for the presence of thrombus and either minor or major dissection. Thrombus was present at 1 minute in 4.

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Objectives: This study sought to correlate angiographically detected complex lesions and intracoronary thrombus with the severity of clinical presentation in unstable angina (UA).

Background: Unstable angina is usually related to acute thrombosis superimposed on a disrupted plaque. Complex and thrombotic lesions are more prevalent in UA and have been associated with a worse prognosis.

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Pseudoaneurysm (PA) formation is a well-documented complication of femoral arterial puncture in patients undergoing percutaneous cardiac procedures. Besides surgical repair, there has been success in obliterating the PAs by Duplex ultrasound guided compression (mostly those < 4.0 cm).

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Background: Recent observations suggest that thrombosis in vivo is initiated via the tissue factor (TF) pathway. The TF activity of human coronary atheroma has not been reported.

Methods And Results: Directional coronary atherectomy (DCA) specimens from 63 lesions were analyzed with the use of a quantitative TF-specific activity assay.

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Anti-bull sperm monoclonal antibodies (mAbs), generated against intra-acrosomal and surface antigens, were evaluated for their functional significance. In experiment I, the influence of mAbs on the bovine sperm-oocyte interaction in vitro was tested on a total of 493 oocytes in either three or four replicate trials. Although the number of sperm bound per zona increased significantly over untreated control samples (23.

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The overall objective of this series of experiments is to generate immunological markers that may elucidate bull sperm surface changes in vitro. Here we report the initial experiments of the study, involving the production and characterization of monoclonal antibodies (mAbs) again bull sperm. BALB/c mice were immunized with phosphate-buffered saline (PBS)-washed whole bull sperm, and their spleen cells were fused with NS-1 myeloma cells in two separate cell fusion experiments, resulting in the generation of 15 mAbs.

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Thrombus formation on a fissured or disrupted atherosclerotic plaque is the main pathogenetic mechanism for the acute coronary syndromes of myocardial infarction and unstable angina. Myocardial infarction results from an acute total occlusion of the artery, while unstable angina is secondary in most cases to mural thrombus formation. Thrombus formation has also been implicated in chronic atherosclerotic disease progression and in restenosis following coronary angioplasty.

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