Pulmonary host defenses and oropharyngeal pathogens
Article Abstract:
Although lung tissue has traditionally been perceived as sterile, evidence indicates that this is not always the case. Oropharyngeal (related to the pharynx and mouth) bacteria have been isolated from lung tissue of healthy individuals. Also, one microbiologic study of dogs found oropharyngeal organisms in 89 percent of the lungs examined. A review is presented of the immune responses that may be involved in lower respiratory tract response to oropharyngeal bacteria. These bacteria seem to be frequently present in lower respiratory tracts, but infrequently result in pneumonia. The sequence of events involved in lower respiratory tract infection and the response of the immune system have been demonstrated in an animal model that can be used to study pulmonary inflammation or immune response. Clearance of oropharyngeal bacteria from the lungs and phagocytic cell (immune cell) response to infection are important aspects of the host defense system. The results of some studies suggest the polymorphonuclear leukocytes (PMS; a type of white blood cell involved in immune response) are recruited to augment host defenses in response to Streptococcus salivarius and Branhamella catarrhalis invasion. Some possible mechanisms of PMS recruitment are discussed. Immunoglobulins G and A have also been implicated in pulmonary immune response and have been detected in bronchoalveolar washings from healthy patients. The precise role of these agents in the body's defense is not clear. Immunization with non-typable Hemophilus influenzae (NTHI) has been shown to induce both serum and bronchoalveolar antibody response. Experiments in mice have indicated enhanced lower respiratory tract clearance of NTHI after immunization with a monoclonal antibody, which indicates that the development of an vaccine for NTHI disease may be feasible. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: American Journal of Medicine
Subject: Health care industry
ISSN: 0002-9343
Year: 1990
User Contributions:
Comment about this article or add new information about this topic:
Tissue-plasminogen activator for pulmonary embolism resulting in shock: two case reports and discussion of the literature
Article Abstract:
Pulmonary embolism (PE) is a blockage of the pulmonary artery, the major blood vessel supplying the lungs, by an embolus, or blood clot. There are 650,000 to 750,000 cases of PE and 200,000 PE-related deaths each year in the United States. When an embolus blocks more than 25 to 50 percent of the artery, major changes in circulation develop. An increase in pulmonary artery pressure causes impaired function of the right heart ventricle and leads to death within the first hour in 11 percent of cases, and within six hours, 85 percent of untreated cases. Blockage of more than 80 percent of the pulmonary blood vessels results in shock, characterized by abnormally low blood pressure and inadequate supply of blood to tissues. Studies have compared the effects of anticoagulants, drugs that prevent blood clotting, with those of thrombolytic agents, which break down existing clots, in treating PE. Thrombolytic agents may be particularly beneficial in treating PE associated with shock. Improvement in the circulation within the lungs was more completely achieved by treatment with the thrombolytic agents streptokinase and urokinase than with the anticoagulant heparin. Animal and human studies have shown that the new thrombolytic agent recombinant human tissue-type plasminogen activator (rt-PA) is both safe and effective in treating PE. Cases are described of two patients with PE resulting in shock who were successfully treated with rt-PA. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: American Journal of Medicine
Subject: Health care industry
ISSN: 0002-9343
Year: 1991
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Choices, beliefs, and infectious disease dynamics. Sensitivity to scale in contingent valuation: the importance of the budget constraint
- Abstracts: Streptokinase therapy for deep vein thrombosis: a comprehensive review of the English literature. Varicella hepatitis in the immunocompromised adult: a case report and review of the literature
- Abstracts: Touching all the bases in diagnostic test assessment. Clinical deterioration in patients with idiopathic pulmonary fibrosis: causes and assessment
- Abstracts: Is it time for a comprehensive AIDS medical center? Aortoesophageal fistula: a comprehensive review of the literature