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DIESEL EXHAUST CAUSES ACUTE INFLAMMATORY RESPONSE

Biomedical researchers have shown that diesel emissions in healthy young adults can cause a marked pulmonary and systemic inflammatory response involving a variety of cell types. Once thought environmentally friendly, diesel engines have been shown to generate up to 100 times more tiny pollutant particles than similar-sized gas engines. Their particles are extremely small, remain in the air for longer periods, and go deeper into the lung. After exposing 11 Australian men and 4 women, average age 24, the researchers concluded that significant short-term diesel exhaust exposure produced a well-defined and marked systemic pulmonary inflammatory response in the healthy volunteers. The research appears in the March issue of the American Journal of Respiratory and Critical Care Medicine.

RESPIRATORY VIRUSES AFFECT WHEEZING INFANTS AND CHILDREN

Clinicians should focus their attention on rhinovirus in older children or respiratory syncytial virus (RSV) in infants to either prevent or treat wheezing attacks. They found that respiratory viruses were present in 82 percent(18 out of 22) of the wheezing infants, with RSV detected in 68 percent of the diagnoses. In 83 percent of the older wheezing children (40 out of 48), they also detected viruses, with 71 percent of those diagnosed harboring rhinoviruses. In addition, they also detected rhinovirus in 40 percent of the infants and 33 percent of the older children who had no clinical symptoms. The study appears in the March issue of the American Journal of Respiratory and Critical Care Medicine.

THE IMPACT OF HUMAN IMMUNODEFICIENCY VIRUS ON TUBERCULOSIS TREATMENT

Among 26 human immunodeficiency virus (HIV)-positive tuberculosis (TB) patients who died during their treatment, TB caused death early in the treatment process for about half of the study group. Later deaths resulted from a pneumonia strain. During the study of 376 cases of TB, of which 190 were HIV-positive, the researchers discovered that profound immune suppression was a strong risk factor for death. They warned that deterioration in a patient already receiving anti-TB therapy should prompt an aggressive search for additional infections. If none can be found, treatment with antifungal and antibacterial agents should begin. The study involved 28,522 black South African gold miners who have a TB incidence three times higher than the general population. It was published in the March issue of the American Journal of Respiratory and Critical Care Medicine.

TYPE OF INTERFERON ENHANCES INFLAMMATORY RESPONSE IN LUNG

According to these investigators, viral infections can play an important role in making asthma worse. However, interferon, a protein produced by cells that produces immunity, can limit the spread of viral infection. Recently, however, these researchers have discovered that a type of interferon called interferon-gamma produced during viral infection primes large cells in the lung called macrophages to release more inflammatory material during allergic responses. They believe that excess production of interferon- gamma could be the responsible inflammatory agent in susceptible individuals with either viral- or allergen-induced asthma. Their research appears in the March issue of the American Journal of Respiratory Cell and Molecular Biology.

For the complete text of the articles, see the ATS Journal Online Website at www.atsjournals.org. To request complimentary journalist access to the site, or to be put on a mailing list for a monthly ATS Media Memo and Â鶹´«Ã½ Briefs, please contact Lori Atkins at (212) 315-6442, by fax at (212) 315-6455, or [email protected].

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