23 research outputs found

    Voltera's Solution of the Wave Equation as Applied to Three-Dimensional Supersonic Airfoil Problems

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    A surface integral is developed which yields solutions of the linearized partial differential equation for supersonic flow. These solutions satisfy boundary conditions arising in wing theory. Particular applications of this general method are made, using acceleration potentials, to flat surfaces and to uniformly loaded lifting surfaces. Rectangular and trapezoidal plan forms are considered along with triangular forms adaptable to swept-forward and swept-back wings. The case of the triangular plan form in sideslip is also included. Emphasis is placed on the systematic application of the method to the lifting surfaces considered and on the possibility of further application

    Diffuse Alveolar Hemorrhage

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    This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Diffuse alveolar hemorrhage[DAH] is a serious condition that can be life threatening. It can be caused by a constellation of disorders which presents with hemoptysis, anemia, and diffuse alveolar infiltrates. Respiratory failure from DAH can be so severe that it has been called an ARDS mimic/imitator. Early recognition is crucial because prompt diagnosis and treatment are required for survival. DAH should be distinguished from other causes of pulmonary hemorrhage caused by localized pulmonary abnormalities and the bronchial circulation. Early bronchoscopy with bronchoalveolar lavage (BAL) is generally required to confirm the diagnosis of DAH and rule out infection. Progressively bloody bronchoalveolar lavage samples can distinguish DAH. Systemic vasculitis is one of the most common causes of DAH and can be pathologically defined by the presence of cellular inflammation, vessel destruction, tissue necrosis, and eventually, organ dysfunction. Corticosteroids and immunosuppressive agents remain the gold standard for the treatment. The following case illustrates a patient who was dependent on dialysis, then presented with hemoptysis. Bronchoscopy demonstrated progressively bloody bronchoalveolar lavage samples consistent with diffuse alveolar hemorrhage. Serologic testing was consistent with microscopic polyangiitis. The patient experienced a clinical remission with cyclophosphamide and corticosteroids

    Systemic lupus erythematosus and diffuse alveolar hemorrhage, etiology and novel treatment strategies.

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    Diffuse alveolar hemorrhage is a severe respiratory complication of systemic lupus erythematosus. The illness develops over hours to a few days and is the systemic lupus erythematosus-associated syndrome with highest mortality. Although no specific symptoms have been identified, a number of features are associated with diffuse alveolar hemorrhage, with a drop in blood hemoglobin the most prominent. Dyspnea, blood-stained sputum, diffuse infiltrates identified by chest imaging, elevated single breath-diffusing capacity for monoxide, thrombocytopenia and C3 hypocomplementemia are other commonly reported signs of diffuse alveolar hemorrhage. The etiology is not completely understood but many patients develop diffuse alveolar hemorrhage concomitant with lupus nephritis, suggesting immune complex-driven pathology. Biopsy studies have identified both cases with capillaritis and a bland non-inflammatory phenotype. An animal model of diffuse alveolar hemorrhage has indicated requirement of B lymphocytes and complement receptor-mediated apoptotic body phagocytosis by monocytes as part of the pathogenesis. This review will discuss considerations when diagnosing the condition and available therapies. Infections and other causes of hemorrhage have to be excluded as these require different treatment strategies. Methylprednisolone and cyclophosphamide remain the most commonly used therapies. Plasmapheresis and rituximab are other beneficial treatment options. A few studies have also considered intrapulmonary Factor VII therapy, extracorporeal membrane oxygenation and mesenchymal stem cell therapy. There is an unmet need of better definition of diffuse alveolar hemorrhages etiology and pathology for development of improved treatment strategies

    Granulocyte-macrophage colony stimulatory factor enhances the pro-inflammatory response of interferon-γ-treated macrophages to pseudomonas aeruginosa infection

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    Pseudomonas aeruginosa is an opportunistic pathogen that can cause severe infections at compromised epithelial surfaces, such those found in burns, wounds, and in lungs damaged by mechanical ventilation or recurrent infections, particularly in cystic fibrosis (CF) patients. CF patients have been proposed to have a Th2 and Th17-biased immune response suggesting that the lack of Th1 and/or over exuberant Th17 responses could contribute to the establishment of chronic P. aeruginosa infection and deterioration of lung function. Accordingly, we have observed that interferon (IFN)-γ production by peripheral blood mononuclear cells from CF patients positively correlated with lung function, particularly in patients chronically infected with P. aeruginosa. In contrast, IL-17A levels tended to correlate negatively with lung function with this trend becoming significant in patients chronically infected with P. aeruginosa. These results are in agreement with IFN-γ and IL-17A playing protective and detrimental roles, respectively, in CF. In order to explore the protective effect of IFN-γ in CF, the effect of IFN-γ alone or in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF), on the ability of human macrophages to control P. aeruginosa growth, resist the cytotoxicity induced by this bacterium or promote inflammation was investigated. Treatment of macrophages with IFN-γ, in the presence and absence of GM-CSF, failed to alter bacterial growth or macrophage survival upon P. aeruginosa infection, but changed the inflammatory potential of macrophages. IFN-γ caused up-regulation of monocyte chemoattractant protein-1 (MCP-1) and TNF-α and down-regulation of IL-10 expression by infected macrophages. GM-CSF in combination with IFN-γ promoted IL-6 production and further reduction of IL-10 synthesis. Comparison of TNF-α vs. IL-10 and IL-6 vs. IL-10 ratios revealed the following hierarchy in regard to the pro-inflammatory potential of human macrophages infected with P. aeruginosa: untreated < treated with GM-CSF < treated with IFN-γ < treated with GM-CSF and IFN-γ

    Diffuse Alveolar Hemorrhage: Take a Look at the Air Side of the Lung

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    Local pulmonary administration of factor VIIa (rFVIIa) in diffuse alveolar hemorrhage (DAH) &amp;ndash; a review of a new treatment paradigm

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    Lars Heslet1, J&amp;oslash;rn Dalsgaard Nielsen2, Steen Nepper-Christensen31Serendex ApS, Parkovsvej 20, Gentofte, DK 2820 Denmark; 2Department of Hematology, University Hospital of Copenhagen, Rigshospitalet, Denmark; 3Department of Otolaryngology/Head and Neck Surgery, University Hospital of Copenhagen, Rigshospitalet, DenmarkBackground: Diffuse alveolar hemorrhage (DAH) is a clinical syndrome with typical symptoms dyspnea and hemoptysis. DAH is a complication of specific diseases, in some cases with acute catastrophic hemoptysis, while other patients present low grade alveolar bleeding with a need of chronic transfusion as in pulmonary hemosiderosis.Methods: Current literature in the PubMed database and other sources was reviewed in order to evaluate the current treatment recommendations, efficacy of this treatment, and finally the risk of complications after off-label use of rFVIIa in respect to DAH.Objectives: (i) To elucidate the clinical aspects of alveolar hemorrhage, (ii) to develop a simple diagnostic algorithm in order to separate DAH from other important pulmonary diseases with similar clinical picture and comparably high mortality. Such an algorithm has important therapeutic consequences because these diseases: acute lung injury (ALI), acute respiratory distress syndrome (ARDS) and bronchiolitis obliterans organizing pneumonia (BOOP) have different therapies, (iii) to evaluate and discuss whether local pulmonary administration may improve outcome and reduce mortality in DAH, and (iv) to suggest a treatment schedule.Results: Hitherto the diagnosis and treatment of DAH has been based on anecdotal reports. The treatment has relied on different unspecific treatment modalities based on a mixture of treatment of the underlying disease and treatment without evidence targeted to stop the alveolar bleeding. However, recently a number of publications have advocated the use of intrapulmonary rFVIIa. Even in severe bleeding DAH has been shown to respond promptly without thromboembolic complication when FVIIa was administered locally via the air side, because the FVIIa does not penetrate the alveolo-capillary membrane to the blood-side. The incidence of DAH (in the US and Europe is 100,000&amp;ndash;150,000, and 50,000 patients annually are at risk of developing DAH following hematopoietic stem cell transplant (HSCT) and autoimmune diseases. Finally 50,000&amp;ndash;100,000 patients may be falsely categorized as having acute respiratory distress syndrome/acute lung injury (ARDS/ALI) because DAH and ARDS cannot be separated clinically. A new treatment paradigm of DAH is proposed as no other intervention has been able to ensure pulmonary hemostasis in DAH. The diagnosis of DAH is simple, a series of broncho-alveolar washes which become increasingly bloody. This test should be performed in all patients with pulmonary opacities in order to separate ARDS/ALI from DAH. FVIIa administrated via pulmonary route is &amp;quot;drug of choice&amp;quot;, because it stops bleeding in the life-threatening syndrome DAH. Hemostasis is obtained after only one to two small doses of FVIIa (50 &amp;micro;g/kg body weight per dose) and after hemostasis the oxygen transport quickly improves.Conclusion: Intrapulmonary administration of rFVIIa is recommended as the treatment of choice for DAH and blast lung injury (BLI) because the treatment has been shown to be successful and uncomplicated in spite of the fact that only a small series of DAH has been documented.Keywords: coagulation factor FVIIa, diffuse alveolar hemorrhage, hemosiderosis, blast lung injury, local pulmonary treatment, biologics, bronchoalveolar lavage, diagnosis, algorithm, new treatment recommendatio

    Acute radiation syndrome (ARS) &amp;ndash; treatment of the reduced host defense

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    Lars Heslet1, Christiane Bay2, Steen Nepper-Christensen31Serendex ApS, Gentofte; 2University of Copenhagen, Medical Faculty, Copenhagen; 3Department of Head and Neck Surgery, Otorhinolaryngology, K&amp;oslash;ge University Hospital, K&amp;oslash;ge, DenmarkBackground: The current radiation threat from the Fukushima power plant accident has prompted rethinking of the contingency plan for prophylaxis and treatment of the acute radiation syndrome (ARS). The well-documented effect of the growth factors (granulocyte colony-stimulating factor [G-CSF] and granulocyte-macrophage colony-stimulating factor [GM-CSF]) in acute radiation injury has become standard treatment for ARS in the United States, based on the fact that growth factors increase number and functions of both macrophages and granulocytes.Methods: Review of the current literature.Results: The lungs have their own host defense system, based on alveolar macrophages. After radiation exposure to the lungs, resting macrophages can no longer be transformed, not even during systemic administration of growth factors because G-CSF/GM-CSF does not penetrate the alveoli. Under normal circumstances, locally-produced GM-CSF receptors transform resting macrophages into fully immunocompetent dendritic cells in the sealed-off pulmonary compartment. However, GM-CSF is not expressed in radiation injured tissue due to defervescence of the macrophages. In order to maintain the macrophage&amp;rsquo;s important role in host defense after radiation exposure, it is hypothesized that it is necessary to administer the drug exogenously in order to uphold the barrier against exogenous and endogenous infections and possibly prevent the potentially lethal systemic infection, which is the main cause of death in ARS.Recommendation: Preemptive treatment should be initiated after suspected exposure of a radiation dose of at least ~2 Gy by prompt dosing of 250&amp;ndash;400 &amp;micro;g GM-CSF/m2 or 5 &amp;micro;g/kg G-CSF administered systemically and concomitant inhalation of GM-CSF ~ 300 mcg per day for at least 14&amp;ndash;21 days.Conclusion: The present United States standard for prevention and treatment of ARS standard intervention should consequently be modified into the combined systemic administration of growth factors and inhaled GM-CSF to ensure the sustained systemic and pulmonary host defense and thus prevent pulmonary dysfunction.Keywords: inhaled and systemically administered GM-CSF, ARS, host defense, orchestration of pulmonary host respons
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