sodium-pertechnetate-tc-99m and Pneumonia

Particulate air pollution is associated with cardiovascular morbidity and mortality. Fine particles with a diameter <2.5 microm (PM2.5) have an important role in triggering biological responses. These particles, and particularly the ultrafine fraction (<100 nm) penetrate deeply into the respiratory tract. Recently, we have demonstrated that ultrafine particles are able to translocate from the lung into the systemic circulation in hamsters and humans. In urban areas, diesel engines are considered to be the major source of PM2.5. We therefore evaluated the acute effect (1 h) of diesel exhaust particles (DEP) in a hamster model of peripheral vascular thrombosis induced by free-radical mediated endothelial injury, using intravenous Rose Bengal and local illumination. Intratracheal doses of 5-500 microg of DEP per animal induced inflammation with elevation of neutrophils, total proteins and histamine in bronchoalveolar lavage. DEP enhanced experimental arterial and venous platelet rich-thrombus formation in vivo. Blood samples taken from hamsters 30 and 60 min after instillation of DEP caused platelet activation, when analyzed in the Platelet Function Analyser (PFA-100). The direct addition of DEP to untreated hamster blood also caused platelet aggregation. These effects persisted up to 24 h after instillation. Our results provide plausible mechanistic explanations for the epidemiologically established link between air pollution and acute cardiovascular effects.

Topics: Adult; Air Pollutants; Animals; Bronchoalveolar Lavage Fluid; Cardiovascular Diseases; Cricetinae; Humans; Inhalation Exposure; Male; Middle Aged; Neutrophils; Particle Size; Platelet Function Tests; Pneumonia; Polystyrenes; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thrombosis; Vehicle Emissions

The value of immunoscintigraphy with technetium-99m (99Tcm) labelled anti-granulocyte monoclonal antibody (BW250/183) was studied prospectively in human immunodeficiency virus (HIV-1) antibody-positive patients presenting with fever without localizing symptoms or signs. Twenty-three studies were performed in 23 patients and the results of 99Tcm-anti-granulocyte imaging were compared with the definitive microbiological or cytological diagnosis. Twenty-one patients had an infective cause of pyrexia, one patient had disseminated lymphoma and one Kaposi sarcoma. 99Tcm-anti-granulocyte antibody imaging correctly identified the sites of infection in only five (24%) patients, four of whom had infective colitis (one also had bacterial pneumonia) and one of whom had cellulitis. Sixteen foci of infection were not localized by 99Tcm-anti-granulocyte immunoscintigraphy (false-negative scans). Six of these patients had Pneumocystis carinii pneumonia; other diagnoses in this group included bacterial or fungal pneumonia and bacteraemia secondary to line infections. 99Tcm-anti-granulocyte antibody did not accumulate in the patients with disseminated lymphoma and Kaposi sarcoma (true-negative scans). 99Tcm-anti-granulocyte imaging, therefore, appears useful in identifying extrathoracic infection in HIV-1 positive patients. Its lack of sensitivity for the identification of pulmonary infection means that its role in the investigation of HIV-1 antibody-positive patients with fever without localizing symptoms or signs is limited.

Topics: Adult; AIDS-Related Opportunistic Infections; Antibodies, Monoclonal; Antibody Specificity; Bacterial Infections; False Negative Reactions; False Positive Reactions; Fever of Unknown Origin; Granulocytes; HIV Infections; Humans; Immunoconjugates; Lung Neoplasms; Lymphoma, AIDS-Related; Male; Middle Aged; Mycoses; Pneumonia; Pneumonia, Pneumocystis; Prospective Studies; Radioimmunodetection; Sarcoma, Kaposi; Sodium Pertechnetate Tc 99m; Virus Diseases

A comprehensive radionuclide study of pulmonary circulation disorders in 55 children with acute pyo-destructive pneumonia (at the age of 1 month to 13 years) revealed the degree of vascular network reduction, pulmonary regional specific activity and changes in the time of the blood flow in the pulmonary circulation microcirculatory channel. These indices of disturbed pulmonary hemodynamics in combination with the results of total perfusion deficiency can serve as diagnostic markers of pulmonary circulation pathology and define a tendency to the generalization of a pyo-destructive process or enhancement of the blood flow of compensatory nature as well as prognosis of a course of disease.

Topics: Acute Disease; Adolescent; Child; Child, Preschool; Female; Humans; Infant; Male; Pneumonia; Pulmonary Circulation; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Aggregated Albumin