Inappropriate use of D-dimer assay and pulmonary CT angiography in the evaluation of suspected acute pulmonary embolism.

The authors question whether the d-dimer assay and pulmonary computed tomography angiography (CTA) are being used appropriately to evaluate suspected acute pulmonary embolism (PE) at their hospital. To answer this question, a retrospective review was performed on all emergency department (ED) patients who underwent d-dimer assay and/or CTA from August 15, 2008, to August 14, 2009. The authors' algorithm for diagnosing PE requires that patients with low or intermediate probability of acute PE undergo a d-dimer assay, followed by CTA if the d-dimer is positive.

Bottom water warming in the North Pacific Ocean.

Observations of changes in the properties of ocean waters have been restricted to surface or intermediate-depth waters, because the detection of change in bottom water is extremely difficult owing to the small magnitude of the expected signals. Nevertheless, temporal changes in the properties of such deep waters across an ocean basin are of particular interest, as they can be used to constrain the transport of water at the bottom of the ocean and to detect changes in the global thermohaline circulation. Here we present a comparison of a trans-Pacific survey completed in 1985 (refs 4, 5) and its repetition in 1999 (ref.

Spring phenology trends in Alberta, Canada: links to ocean temperature.

Warmer winter and spring temperatures have been noted over the last century in Western Canada. Earlier spring plant development in recent decades has been reported for Europe, but not for North America. The first-bloom dates for Edmonton, Alberta, were extracted from four historical data sets, and a spring flowering index showed progressively earlier development.

Effects of colchicine on IgE-mediated early and late airway reactions.

Background: The pathogenesis of bronchial asthma is thought to involve elements of both acute and chronic inflammation. Hence, there is growing interest in the potential of immunomodulatory drugs in asthma therapy. This study examines the effects of the anti-inflammatory compound colchicine on early and late allergen-induced, IgE-mediated airway reactions.

An assessment of the effects of glucocorticoids on degranulation, chemotaxis, binding to vascular endothelium and formation of leukotriene B4 by purified human neutrophils.

Glucocorticoids exert their actions through a time-dependent, receptor-mediated, protein synthesis- and RNA synthesis-dependent mechanism. We have assessed the effects of 24-h culture of human neutrophils with dexamethasone on degranulation, chemotaxis, binding to vascular endothelium and formation of leukotriene B4. Purified neutrophils contained an average of 2896 [3H]dexamethasone binding sites per cell with a Kd of 4.

Leukotriene B4 as a mediator of early and late reactions to antigen in humans: the effect of systemic glucocorticoid treatment in vivo.

The role played by leukotriene B4 (LTB4) in human allergic reactions has been the subject of recent interest and speculation. To characterize further the role of this mediator, we quantitated LTB4 levels in nasal washing by radioimmunoassay in 13 atopic subjects during immediate and late reactions after nasal antigen challenge while the subjects were taking placebo or prednisone (20 mg every 8 hours for 48 hours) in a double-blind, placebo-controlled, crossover protocol and compared these levels with levels of seven nonatopic subjects undergoing similar nasal antigen challenge. Nasal antigen challenge of atopic subjects resulted in an increase in LTB4 levels during the immediate reaction in 10 of 13 subjects (9/13 with a greater than 50% increase over baseline) with no similar increase observed in nonatopic subjects (p less than 0.

Generation of leukotriene B4 by human lung fragments and purified human lung mast cells.

Leukotriene B4 (LTB4) is a potent stimulus for neutrophil chemotaxis, aggregation, and activation. Although this mediator has been postulated as a possible stimulus for the neutrophil accumulation seen after mast cell triggering in vivo, the ability of human mast cells to produce this leukotriene has never been described. The purpose of this study was to investigate the ability of purified human lung mast cells and mast cells in lung fragments to generate leukotriene B4 after immunologic (anti-IgE) and nonimmunologic (calcium ionophore, A23187) activation.

The role of cyclooxygenase and lipoxygenase mediators in oxidant-induced lung injury.

Infusion of the oxidant lipid peroxide tert-butyl hydroperoxide (t-bu-OOH) causes pulmonary vasoconstriction and increases vascular permeability in isolated perfused rabbit lungs. We have previously shown that t-bu-OOH stimulates arachidonic acid metabolism, increasing the synthesis of the cyclooxygenase products. The current experiments were designed to determine the role that cyclooxygenase- and lipoxygenase-derived mediators play in the lung injury caused by t-bu-OOH.

Purified human basophils do not generate LTB4.

We investigated the release of the 5-lipoxygenase derivatives of arachidonic acid (AA) in purified human basophils and compared them with similar results obtained in the human lung mast cell. We have shown that purified basophils (average purity = 51 +/- 6%) challenged with 0.1 microgram/ml anti-IgE released histamine (35 +/- 9%), and LTC4 (32 +/- 10 ng/10(6) cells) but failed to release measurable quantities of immunoreactive LTB4.

Recurrent pulmonary infections in patients with chronic lymphocytic leukemia and hypogammaglobulinemia.

We describe two patients with concomitant recurrent pulmonary infections due to encapsulated organisms and chronic lymphocytic leukemia and hypogammaglobulinemia. We discuss the cases as a subset of acquired hypogammaglobulinemia in adults, focusing on the possible role of impaired defense mechanisms and emphasizing the importance of aggressive therapy with gamma globulin, antibiotics, and good pulmonary toilet to reduce morbidity.

Intrabronchial lesion on computed tomography secondary to blood clot.

A case of a blood clot simulating an intrabronchial neoplasm on computed tomography is presented. Although an intrabronchial lesion in a patient with hemoptysis is usually a malignancy, other etiologies must be considered. Computed tomography is an excellent modality for detecting and evaluating intrabronchial pathology but bronchoscopy is necessary for tissue diagnosis.