Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0032285 (pneumonia)
 54,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Corticosteroids have previously been found to be protective against the mortality of radiation pneumonitis in mice, even when given well after lethal lung irradiation. We explored the possibility that this effect was due to their well-known anti-inflammatory actions by giving various nonsteroidal inhibitors of arachidonate metabolism to groups of mice that had received 19 Gy to the thorax (bilaterally). Treatments of four cyclooxygenase inhibitors, one lipoxygenase inhibitor, and one leukotriene receptor antagonist, given by various routes in various doses, were commenced 10 weeks after irradiation or sham irradiation and continued throughout the period when death from radiation pneumonitis occurs, 11-26 weeks after irradiation. Each of the treatments had the appropriate effect on arachidonate metabolism in the lungs as assessed by LTB4 and PGE2 levels in lung lavage fluid. The principal end point was mortality. The 5-lipoxygenase inhibitor diethylcarbamazine and the LTD4/LTE4 receptor antagonist LY 171883 markedly reduced mortality in dose-response fashion. The effects of cyclooxygenase inhibitors were divergent; piroxicam and ibuprofen were marginally protective, indomethacin in all doses accelerated mortality, and aspirin reduced mortality in a dose-response fashion. These results suggest that the protective effect of corticosteroids in radiation pneumonitis can be tentatively attributed to their anti-inflammatory actions, and that nonsteroidal anti-inflammatory agents, particularly those that affect lipoxygenase products, may offer equal or better protection than corticosteroids against mortality due to radiation pneumonitis.
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PMID:Effects of some nonsteroidal anti-inflammatory agents on experimental radiation pneumonitis. 188 88

Amiodarone (ADR), a new antiarrhythmic drug for life-threatening cardiac arrhythmias, causes pneumonitis or lung fibrosis in a sizeable minority of patients. The cause of lung damage is not known. We have shown that infusion of 10 mg amiodarone into the inflow circuit of ventilated and perfused rabbit lungs causes immediate increase in pulmonary artery pressure (mean +/- SEM) (from 13.6 +/- 1.2 to 40.6 +/- 9.5 mm Hg, p less than 0.01) and pulmonary edema with marked increase in the pulmonary generation of thromboxane and leukotrienes C4 and/or D4. Albumin (2 g%) in the perfusate prevents any increase in lung perfusion pressure or edema formation. When lung perfusion pressure increase is blocked with the combined cyclooxygenase and lipoxygenase inhibitor enolicam sodium (CG5391B, 35 microM in perfusate), significant lung edema still occurs after amiodarone, indicating that amiodarone causes increased alveolar-capillary membrane permeability. Addition of catalase (100 U/ml) or superoxide dismutase and catalase (100 U/ml each) to perfusate fails to protect from amiodarone lung injury. Immediate infusion of amiodarone (10 mg) into lungs ventilated with room air (ADR + RA) causes an increase in lung weight gain from baseline (delta W) of 5.7 +/- 1.5 g/min. Compared with ADR + RA, ventilation of lungs with 4% O2 (delta W = 0.7 +/- 0.3 g/min, p less than 0.05), pretreatment of rabbits for 3 days with butylated hydroxyanisole (BHA, 100 mg/kg/day i.p., delta W = 0.05 +/- 0.02 g/min, p less than 0.01), pretreatment of rabbits for 3 days with vitamin E (Vit E, 300 U/day orally, delta W = 0.6 +/- 0.2 g/min, p less than 0.05), or addition of N-acetylcysteine to the lung perfusate (NAC, 5 mM, delta W = 0.1 +/- 0.08 g/min, p less than 0.01) all protect from lung edema formation after amiodarone. Amiodarone (100 mg) also caused a marked increase in luminol-enhanced lung chemiluminescence, lung production of superoxide anion (O2-), and tissue levels of lung glutathione disulfide. These results suggest that amiodarone causes lung injury by an oxidant mechanism.
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PMID:Amiodarone causes acute oxidant lung injury in ventilated and perfused rabbit lungs. 245 31

We examined the airway secretory apparatus of adult sheep with experimental pneumonia to look for morphologic and lectin-binding correlates of increased mucus production. The animals were inoculated in the right caudal lobar bronchus either with starch broth containing Pasteurella haemolytica (INF, n = 6), starch broth alone (SHAM, n = 6), or with P. haemolytica and subsequently treated (INF/T, n = 5) with 2 mg/kg indomethacin, subcutaneously three times daily for 6 days. In the INF and INF/T groups, a localized pneumonic infiltrate containing P. haemolytica organisms was present. The bronchi (18-23rd generation) adjacent to the pneumonic lesion had an increased gland volume fraction (6.3 +/- 3.7% in INF, 11.3 +/- 2.4% in INF/T, and 3.1 +/- 1.9% in SHAM, p less than 0.05 among the three). The mean population densities of BSA-reactive (identifying alpha-D-gal) cells were 41.9 +/- 2.7% in the INF, 40.1 +/- 5.6% in the INF/T, versus 14.3 +/- 1.5% in the SHAM group (p less than 0.05), while the corresponding values for PNA-reactive [identifying beta-D-gal(1----3)-D-galNAc] cells were 28.8 +/- 5.1%, 0%, and 0%, respectively. Nor morphologic abnormalities were seen in the trachea, but BSA staining was shifted to morphologically different mucous cells in the INF and INF/T. We conclude that in localized P. haemolytica pneumonia in sheep (1) there are morphologic changes of the airway secretory apparatus adjacent to the lesion, (2) the glycoconjugate profile of secretory cells adjacent to and remote from the lesion is altered, and (3) cyclooxygenase products influence the chemical composition of secretory cells.
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PMID:Lectin-detectable effects of localized pneumonia on airway mucous cell populations: role of cyclooxygenase metabolites. 249 33

Eicosanoid production during phagocytosis of pyogenic bacteria by rabbit alveolar macrophages was studied as a model of early events in the pathogenesis of pneumonia. Adherent alveolar macrophages, prelabelled with [3H]-arachidonic acid (AA), were incubated with live, opsonized Staphylococcus aureus or Pseudomonas aeruginosa (bacteria:macrophage ratio of 50:1) at 37 degrees C for 90 min. Supernatant eicosanoids were extracted and separated by reverse phase high performance liquid chromatography (RP-HPLC). While the amounts of labelled PGE2, TXB2, and PGD2 produced in response to the two organisms were equal, the amount of PGF2 alpha elicited by S. aureus amounted to three times that released during macrophage challenge with P. aeruginosa. Overall, preferential release of cyclooxygenase products occurred during phagocytosis of S. aureus. In contrast, eicosanoids identified presumptively as oxygenated metabolites of AA predominated in cultures challenged with opsonized P. aeruginosa. Live, non-opsonized P. aeruginosa elicited the same profile of eicosanoids, but in reduced amounts. Inhibitor studies indicated that these AA derivatives were not synthesized via the macrophage lipoxygenase pathway. Their production was dependent on the viability of P. aeruginosa. Macrophages challenged with opsonized, heat-killed P. aeruginosa resulted in production of an eicosanoid profile similar to that elicited by S. aureus. Secondary metabolism by P. aeruginosa of eicosanoids released from the macrophage did not contribute to the unique profile produced during the interaction of this organism with labelled macrophages. Our data indicate that during binding to macrophages, the primary human pathogen, P. aeruginosa, specifically modulates the profile of eicosanoids produced. This effect on inflammatory mediators may be of biological significance in the pathogenesis of pneumonia.
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PMID:Eicosanoids produced during interactions between Pseudomonas aeruginosa and alveolar macrophages are species-dependent. 250 45

The initial experience with cardiac bypass in fetal lambs resulted in early fetal death from placental insufficiency. Subsequent work in our laboratory indicated that vasoactive cyclooxygenase products were released as mediators of this response. The placental dysfunction could be blocked by the administration of indomethacin, allowing longer fetal survival. This unmasked a more subacute (but fatal) problem: fetal surgical stress resulted in diminished fetal cardiac output and progressive metabolic acidosis and contributed to the placental vasoconstriction. In acute studies, when indomethacin was given and the stress response was inhibited by the use of total spinal anesthesia, the fetus maintained normal blood gas levels, cardiac output, placental blood flow, and acid-base status for several hours after bypass. We hypothesized that beyond this point, no further fetal or placental compromise would occur and that this management technique would thus allow long-term fetal survival. With the use of total spinal anesthesia and sterile technique for long-term study, 12 fetal lambs at 120 days (80%) gestation underwent exposure, line placement, and cannulation for fetal cardiac bypass. Indomethacin was given intravenously on obtaining venous access. After 20 minutes of normothermic cardiac bypass at flow rates of 250 to 300 ml/kg/min, the fetus was weaned from bypass, the cannulas and lines were removed, the uterus and abdomen were closed, and the ewe and fetus were allowed to recover. There was one maternal death (pneumonia) and one early abortion (of twins); the remaining 10 ewes progressed to term. At term, five healthy lambs that had undergone fetal cardiac bypass were delivered (including one twin), four ewes delivered a mummified study fetus and one or two healthy siblings, and one delivered a dead term fetus. With the use of techniques that inhibit fetal stress and block placental vasoconstriction, cardiac bypass can be performed in single-gestation fetal lambs with a high degree of recovery and survival (80% in this study). The cause of the elevated abortion rate associated with twin gestation is unclear.
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PMID:Long-term survivors of fetal cardiac bypass in lambs. 819 83

The major determinant of abnormal pulmonary gas exchange in patients with pneumonia is characterized by marked increases in intrapulmonary shunt combined with mild to moderate ventilation-perfusion (VA/Q) inequalities. Other mechanisms influencing the levels of arterial hypoxemia, such as disequilibrium of alveolar to endcapillary oxygen diffusion or increased intrapulmonary parenchymal oxygen uptake, are trivial in the clinical arena. These pathophysiological findings mostly concur with the structural derangement of pneumonic areas. On breathing oxygen, the dispersion of pulmonary blood flow, an index sensitive to both normal and low VA/Q ratios, increases (worsens), suggesting that hypoxic pulmonary vasoconstriction is abolished, whereas intrapulmonary shunt remains unchanged. This response differs from that developed by patients with acute respiratory distress syndrome (ARDS) in whom shunt increases moderately, thereby suggesting the development of reabsorption atelectasis, but VA/Q abnormalities remain unaltered. The effects of different drugs aimed at blocking the cyclooxygenase pathway to potentially enhance the mitigated hypoxic pulmonary vasoconstriction in the consolidated lung regions have shown to be individually variable and, in general, minimally beneficial; in contrast, the recent introduction of aerosolized vasodilators may benefit patients.
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PMID:Update '96 on pulmonary gas exchange pathophysiology in pneumonia. 888 58

Iatrogenic respiratory disorders include bronchic manifestations (asthma, bronchospasm, cough) and bronchiolar manifestations (constrictive or proliferative bronchiolitis). Many pharmacologic agents can induce a bronchospasm. The bronchospasm induced by acetylsalicylic acid and nonsteroidal anti-inflammatory agents, often severe, is mediated by the inhibition of the cyclooxygenase enzyme; it can be prevented by eviction of the drug or desensitization. Leukotriene receptor antagonists and 5-lipoxygenase inhibitors may also be useful. Beta-blockers including cardioselective beta-blockers, cholinergic agonists, inhaled agents, angiotensin-converting enzyme inhibitors (ACE), vindesine, histamine liberators, etc..., can also induce a bronchospasm. Most of the same agents can also induce an isolated cough, particularly beta-blockers, inhaled agents, and ACE, which cause 75% of the reported cases of iatrogenic cough. ACE-induced cough usually disappears within 1 to 4 days after withdrawal of the treatment, confirming the diagnosis; ACE-induced cough may be prevented by sodium cromoglycate. The risk of obliterans bronchiolitis with expiratory airflow impairment during rheumatoid arthritis is increased by D-penicillamine. Many drugs can be involved in the pathogenesis of bronchiolitis obliterans organizing pneumonia, which presents with various clinical and radiological aspects. The physician has to keep in mind that bronchospasm, cough, or bronchiolitis of unknown origin, may have a iatrogenic cause.
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PMID:[Iatrogenic drug-induced bronchospasm, cough, and bronchiolitis. Etiologic and physiopathologic aspects]. 892 89

The purpose of this study was to determine the effects of aminoguanidine (AG) and meclofenamate (MEC) on depressed contractility of small pulmonary artery (PA) rings isolated from a rat model of acute Pseudomonas pneumonia. Contractility of PA rings from lungs of control or pneumonia rats was assessed in vitro by obtaining cumulative concentration-contraction curves to potassium chloride (KCl), phenylephrine (PE), and prostaglandin F2alpha (PGF2alpha) on rings treated with or without MEC (1.0 microM), AG (100 microM), or AG + MEC. Vessels from pneumonia rats exhibited significant attenuation of the contractile responses to KCl, PE, and PGF2alpha. MEC restored the KCl and PGF2alpha contractile responses to control values, but had no effect on the attenuated PE contractile response. In contrast, AG restored the PE contractile response, and only partially affected contractile responses to KCl and PGF2alpha, MEC + AG restored the contractile responses of all three agonists. We conclude that both excess nitric oxide (NO) and cyclooxygenase products contribute to the depressed pulmonary vascular contractility observed in rats with acute pneumonia. The relative importance of NO and cyclooxygenase products in this phenomenon depends on the contractile agonist studied.
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PMID:Pulmonary artery contractility in pneumonia: role of cyclooxygenase products and nitric oxide. 1047 Oct 9

Mammalian cells contain two related but unique isoforms of cyclooxygenase (COX-1 and COX-2). COX-1 is expressed constitutively in a majority of tissues and is involved in the production of prostaglandins (PGs) that modulate normal physiologic functions. COX-2 is inducible by various stimuli and is involved in the production of PGs that modulate physiologic events in development, cell growth, and inflammation. With the exception of peribronchial glands and chondrocytes of peribronchial cartilage, COX-2 is not detectable in the normal lung of nonhuman primates. We evaluated COX-2 expression by immunohistochemical methods in the inflammatory lesions of two cynomolgus monkeys (Macaca fascicularis) with acute severe pneumonia. Both monkeys exhibited acute severe bronchopneumonia; histologically, lung lesions were characterized by infiltration of large numbers of neutrophils and fewer macrophages, mild bronchial epithelial hyperplasia, and slight type-2 pneumocyte hyperplasia. In both monkeys, mild to marked COX-2 immunoreactivity was detected within the cytoplasm of macrophages, bronchial epithelial cells, type-2 pneumocytes, and endothelial cells of blood vessels. No COX-2 immunoreactivity was detectable in the neutrophils that constituted >90% of the inflammatory cells. These observations suggest that in acute inflammatory lung lesions in nonhuman primates 1) COX-2 is induced in the bronchial and alveolar epithelial cells, 2) macrophages are the primary inflammatory cells that exhibit COX-2, and 3) neutrophils do not express COX-2.
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PMID:Cyclooxygenase-2 expression in inflammatory lung lesions of nonhuman primates. 1105 86

Adverse reactions to acetylsalicylic acid (aspirin, ASA) and other non-steroidal anti-inflammatory drugs (NSAIDs) are the second most important cause of adverse drug reactions (ARDs) after beta-lactams. They produce various clinical manifestations and can affect different organs. Gastrointestinal reactions (pyrosis, vomiting, gastralgia), neurological reactions (tinnitus, deafness, vertigo), blood dyscrasias, and nephrotoxic and hepatotoxic reactions are well known.NSAIDs are the drugs of choice in the treatment of chronic arthropathies and other childhood connective-tissue diseases and are also commonly used in the treatment of febrile and acute inflammatory processes. Not all NAIDs are authorized for use in the pediatric population but their spectrum of use varies according to the entity for which they are indicated and the legislation of the country. Published studies on the prevalence of aspirin intolerance in patients with bronchial asthma show a fair amount of disagreement. This may be due to (i) the method of selecting asthmatic patients for the study, which differs according to whether all asthmatic patients are included or only those dependent on corticoids; (ii) the diagnostic method used, whether based on clinical criteria or oral provocation tests, which will affect the number of patients with a diagnosis of intolerance. In children aged less than 10 years, including children with asthma, the prevalence is low, while among children and young adults aged 10-20 years old, the prevalence is estimated at 10 %. Some hypotheses attempt to explain the mechanisms through which adverse reactions to NAIDs take place. One hypothesis attributes the reaction to a reaginic immunological mechanism but this hypothesis has only been confirmed in exceptional cases. The theory of the cyclooxygenase pathway, currently the most widely accepted, is based on the ability of NSAIDs to inhibit the cyclooxygenase pathway of arachidonic acid metabolism, leading to prostaglandin depletion and an increase in leukotrienes. The discovery of two isoforms of the cyclooxygenase enzymes, COX-1 and COX-2, has represented a great advance in our understanding of the mechanism of action of NSAIDs and has also elucidated the problem of cross-reactivities. According to the theory of viral infection, aspirin-induced asthma could be caused by chronic viral infection since, after initial exposure to the virus, cytotoxic lymphocytes are produced. Their activity is inhibited by prostaglandin E2 (PGE2); aspirin and other NSAIDs block PGE2 production and allow cytotoxic lymphocytes to attack and eliminate the respiratory tract cells infected by the virus. During this reaction lysosomal enzymes and mediators are released, which could precipitate an asthmatic crisis.Clinically, five types of reaction have been identified: 1. Respiratory illness with aspirin sensitivity. 2. Aspirin-induced urticarial disease. 3. Allergic reactions to NSAIDs and aspirin. 4 and 5. Aseptic meningitis and pneumonitis due to hypersensitivity. The latter are exceptional and are published as case reports. They have never been associated with aspirin or acetaminophen and usually occur in patients undergoing prolonged treatment. Diagnosis is based on a detailed history. Skin tests are not valid and in vitro tests are not widely used. Provocation tests with aspirin and NSAIDs definitively identify sensitized patients but their indications and limitations should be kept in mind. In children, certain features of adverse reactions to NSAIDs are observed in relation to their incidence and clinical manifestations. Acetaminophen is considered the drug of choice but further studies of other alternatives in children are required.
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PMID:[Special features of NSAID intolerance in children]. 1278 61


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