Objectives: Respiratory failure is a lethal complication of COVID-19 that has remained resistant to drug therapy. Vasoactive intestinal peptide (VIP) is shown in nonclinical studies to upregulate surfactant production, inhibit cytokine synthesis, prevent cytopathy, and block replication of the severe acute respiratory syndrome coronavirus 2 virus in pulmonary cells. The study aims to determine whether Aviptadil (synthetic VIP) can improve survival and recovery in patients with COVID-19 respiratory failure compared with placebo and demonstrate biological effects in such patients.
View Article and Find Full Text PDFObjectives: We hypothesized performance improvement interventions would improve COPD guideline-recommended care and decrease COPD exacerbations in primary care clinic practices.
Methods: We initiated a performance improvement project in 12 clinics to improve COPD outcomes incorporating physician education, case management, web-based decision support (CareManager(TM)), and performance feedback. We collected baseline and one-year follow up data on 242 patients who had COPD with acute exacerbations.
Fibrosing mediastinitis and sclerosing cervicitis are fibrosclerotic disorders akin to retroperitoneal fibrosis, with presenting symptoms related to local pain or viscus obstruction or both. No definitive treatment is known. This is the first report of these disorders dramatically responding to tamoxifen citrate and prednisone.
View Article and Find Full Text PDFMagnetic resonance spectroscopy (MRS) is a non-invasive method of obtaining biochemical information. Patients or experimental animals are placed within a magnetic imaging device and specific patterns of chemical spectra, such as P31 patterns of adenosine triphosphate (ATP) can be recorded. We have injured the isolated rat lung by complement activation and hypoxia.
View Article and Find Full Text PDFThe role of neutrophils (PMNs) in ischemia-reperfusion injury after lung transplantation is unclear. If PMNs are involved in ischemia-reperfusion injury in the intact rat, then PMNs should sequester in the injured lung and PMN-depleted rats should develop less injury. Group A rats were treated with a rabbit anti-rat PMN antibody causing profound neutropenia (less than 100 PMNs/microL) and group B with control serum (greater than 2,000 PMNs/microL).
View Article and Find Full Text PDFCricothyroidotomy as a method of elective airway management, previously shunned by Jackson, was reintroduced to the medical community in 1976. This article examines available data indicating the utility and complications of elective cricothyroidotomy for long-term airway management and defines its place with respect to tracheotomy.
View Article and Find Full Text PDFWe investigated if cyclooxygenase metabolites of arachidonic acid were involved in ischemia-reperfusion lung injury by determining if inhibition of their production attenuated the injury. Isolated rat lungs were perfused with physiologic salt solution osmotically stabilized with Ficoll until circulating blood elements were not detected in lung effluent. Ischemia was induced by stopping ventilation and perfusion for 90 min.
View Article and Find Full Text PDFAm J Respir Cell Mol Biol
October 1990
We hypothesized that Iloprost, a long-acting prostacyclin analog, would inhibit neutrophil (PMN)-induced lung injury and decrease PMN adherence to vascular endothelium. Human PMNs infused into isolated buffer-perfused rat lungs subsequently stimulated with phorbol myristate acetate (PMA) resulted in lung injury as assessed by the accumulation of [125I]bovine serum albumin (125I-BSA) in lung parenchyma and alveolar lavage fluid. Addition of Iloprost to the lung perfusate, prior to activation of the PMNs, reduced lung injury as assessed by a decrease in the accumulation of 125I-BSA in the lung.
View Article and Find Full Text PDFWe retrospectively investigated if the clinical course of complicated parapneumonic effusions was altered by treatment with immediate drainage plus antibiotics vs antibiotics alone. The two groups of patients had no significant differences in age, duration of symptoms prior to hospitalization, initial maximum temperature, WBC count, or characteristics of the pleural fluid. There were no differences in the duration of hospitalization, fever, elevated WBC count, intravenous antibiotic therapy, or the time for roentgenographic resolution of the effusions.
View Article and Find Full Text PDFPulmonary hypertension occurs after the intravascular activation of complement. However, it is unclear which activated complement fragments are responsible for the pulmonary vascular constriction. We investigated the 21-carboxy-terminal peptide of C3a (C3a57-77) to see if it would cause pulmonary vascular constriction when infused into isolated buffer-perfused rat lungs.
View Article and Find Full Text PDFJ Appl Physiol (1985)
January 1990
Ischemia-reperfusion lung injury limits lung transplantation. Neutrophil activation and/or xanthine oxidase-mediated purine degradation may cause toxic oxygen metabolite production and lung injury. We investigated whether circulating blood elements are involved in the pathogenesis of ischemia-reperfusion lung injury.
View Article and Find Full Text PDFLipoxygenase metabolites of arachidonic acid have been proposed as possible mediators of hypoxic pulmonary vasoconstriction (HPV) in the rat. Since reduced glutathione (GSH) is a required substrate for the synthesis of the sulfidopeptide eicosanoid leukotriene C4 (LTC4), we reasoned that this specific GSH dependence of LTC4 synthesis might allow us to distinguish between the roles of sulfidopeptide leukotrienes and other 5-lipoxygenase metabolites of arachidonic acid. In the present study we have examined the effect of in vivo pretreatment with the GSH synthesis inhibitor buthionine sulfoximine (BSO) on both the hypoxic pressor response and lung leukotriene synthesis in the rat.
View Article and Find Full Text PDFArachidonate metabolites appear to be involved in lung injury caused by cobra venom factor (CVF)-induced complement and polymorphonuclear leukocyte (PMN) activation. These studies were designed to assess the effects of a dietary-induced deficiency of arachidonic acid on CVF-induced lung injury. Rats raised on an essential fatty acid-deficient (EFAD) diet exhibited the expected changes in fatty acid composition including decreased plasma levels of arachidonic acid and increased levels of 5,8,11-eicosatrienoic acid.
View Article and Find Full Text PDFInasmuch as the recruitment of polymorphonuclear leukocytes (PMNs) to inflammatory foci in vivo involves adhesion-dependent events (e.g., margination, diapedesis, and directed migration), we sought to characterize the relationship between the local accumulation of PMNs in sterile peritonitis and their surface expression of the adhesion-promoting plasma membrane glycoprotein, Mo1 (CD11b/CD18).
View Article and Find Full Text PDFThe susceptibility of lung tissue to ischemia-reperfusion injury has made distant procurement of heart-lung allografts difficult. The effects of hypothermia, ventilation without perfusion, and various reperfusion solutions (PSS/Ficoll or whole blood) on the development of ischemia-reperfusion lung injury were investigated. Use of an ex vivo rat lung model in which the above variables were individually varied permitted a direct approach for these studies.
View Article and Find Full Text PDFWe hypothesized that neutrophil adhesion and lung injury could occur independent of the surface receptor glycoprotein, Mo1 (C3bi receptor). We investigated whether preincubation of human neutrophil-derived cytoplasts (cell fragments that lack nuclei and granules and have a fixed number of surface Mo1 receptors) with plasma and lipopolysaccharide (LPS) would augment the cytoplasts' ability to cause lung injury when activated. We also investigated whether preincubating normal human neutrophils treated with anti-Mo1 antibody with plasma and LPS would increase the neutrophils' ability to adhere and cause lung injury.
View Article and Find Full Text PDFCerulein-induced acute pancreatitis in rats is associated with acute lung injury characterized by increased pulmonary microvascular permeability, increased wet lung weights, and histologic features of alveolar capillary endothelial cell and pulmonary parenchymal injury. The alveolar capillary permeability index is increased 1.8-fold after a 3-hour injury (0.
View Article and Find Full Text PDFIschemic-reperfusion lung injury is a factor potentially limiting the usefulness of distant organ procurement for heart-lung transplantation. Toxic oxygen metabolites are considered a major etiologic factor in reperfusion injury. Although oxygen-free radicals may be generated by many mechanisms, we investigated the role of xanthine oxidase in this injury process by using lodoxamide, a xanthine oxidase inhibitor, to inhibit ischemic-reperfusion injury in an isolated rat lung model.
View Article and Find Full Text PDFThe vast majority of patients who undergo mechanical ventilation are able to discontinue ventilatory assistance within a few days. Typically, patients who require only short-term mechanical ventilation do not have severe underlying lung disease, and the problem for which they require ventilatory support is most commonly rapidly reversible. In these patients on short-term ventilatory support, parameters of spontaneous ventilatory requirements and respiratory muscle strength, including minute ventilation, maximal voluntary ventilation, vital capacity, and maximal inspiratory pressure, are useful in predicting the success of discontinuation of mechanical ventilation.
View Article and Find Full Text PDFIntravenous injection of the complement activator, cobra venom factor (CVF), produces acute lung injury that is neutrophil-dependent and oxygen radical mediated. Using the ex vivo model of lung perfusion, the current studies were designed to measure the appearance of eicosanoids in relation to the development of pulmonary arterial hypertension and vascular permeability. Inhibitors of the cyclooxygenase and lipoxygenase pathways were also employed to assess the possible role of eicosanoids in these two functional responses.
View Article and Find Full Text PDFClin Immunol Immunopathol
February 1988
Mo1, LFA-1, and p150,95 are structurally related glycoproteins of the CD11/CD18 complex that are expressed on the membrane of human leukocytes. In the neutrophil, the surface expression of the CD11/CD18 complex is up-modulated (Mo1 greater than p150,95 much greater than LFA-1) by stimulatory factors that include calcium ionophore A23187, phorbol myristate acetate (PMA), and N-L-formyl-L-leucyl-L-phenylalanine (fMLP). Here, in an immunofluorescence analysis, we have examined CD11/CD18 glycoprotein expression by human monocytes, pulmonary alveolar macrophages (PAM, obtained by bronchoalveolar lavage), and breast milk macrophages (BMM) as compared to neutrophils before and after exposure to A23187 (1 microM), fMLP (0.
View Article and Find Full Text PDFThe polymorphonuclear leukocyte (neutrophil) is the most important phagocytic cell that defends the host against acute bacterial infection. Disorders of neutrophil function are suggested by recurrent cutaneous, periodontal, respiratory, or soft tissue infections. Staphylococcus aureus, gram-negative bacilli, and less commonly, Candida albicans, are the causative organisms.
View Article and Find Full Text PDFCobra venom factor (CVF)-induced systemic activation of the complement system in the rat has been shown to result in the development of acute lung microvascular injury and appearance in lungs and plasma of lipid peroxidation products. The pathogenesis of these events is dependent on complement and neutrophils and is sensitive to pretreatment of experimental animals with iron chelators or scavengers of hydroxyl radical. In order to further analyze the role of complement in the pathogenesis of acute lung injury in rats after systemic complement activation, two different CVFs have been employed in the present study.
View Article and Find Full Text PDF