Osteopontin (OPN, also known as Eta-1), a noncollagenous matrix protein produced by macrophages and T lymphocytes, is expressed in granulomatous lesions caused by Mycobacterium tuberculosis infection. In the present study, we compared plasma concentrations of OPN in patients with active pulmonary tuberculosis with those of healthy control subjects and patients with sarcoidosis, another disease associated with granuloma formation. Plasma OPN levels were significantly higher in patients with tuberculosis (n = 48) than in control subjects (n = 34) and patients with sarcoidosis (n = 20). OPN levels correlated well with severity of pulmonary tuberculosis, as indicated by the size of lung lesions on chest X-ray films. Furthermore, chemotherapy resulted in a significant fall in plasma OPN levels. In patients with tuberculosis, plasma OPN concentrations correlated significantly with those of interleukin (IL)-12. In vitro experiments showed that OPN production by peripheral blood mononuclear cells infected with Mycobacterium bovis bacillus Calmette-Guérin preceded the synthesis of IL-12 and interferon-gamma and that the neutralizing anti-OPN monoclonal antibody significantly reduced the production of IL-12 and interferon-gamma. Our results suggest that OPN may be involved in the pathologic process associated with active pulmonary tuberculosis by inducing IL-12-mediated type 1 T helper cell responses.
Streptococci that colonize the mouth and upper respiratory tract tend to be considered harmless commensals. In 45 cases of acute pneumonia and/or pulmonary abscess and 25 cases of thoracic empyema, the predominant species recovered were anaerobic bacteria and the Streptococcus milleri group, which encompasses the oral species Streptococcus anginosus, Streptococcus constellatus, and Streptococcus intermedius. The isolation of most S. milleri organisms along with oral anaerobes indicated synergy between these groups. Studies in a mouse model of pneumonia demonstrated this synergy; mortality was higher, histopathologic abnormalities were more marked (reflecting acute pneumonia followed by pulmonary abscess or empyema), and viable bacteria were more numerous in the lungs of mice with mixed infections caused by the S. milleri group and anaerobes than in the lungs of those with monomicrobial infection. In vitro studies elucidated a possible mechanism of this synergistic effect: anaerobes may enhance the growth of the S. milleri group and/or inhibit the bactericidal activity of the host. We conclude that the S. milleri group is more important in pulmonary infections than has previously been recognized.
Summary.The relationship between Streptococcus constellatus, one of the species of the "Streptococcus milleri group ", and Prevotella intermedia was studied in a model of pneumonia in mice and in vitro to elucidate mechanisms of pathogenicity in " S . milleri group "-associated pulmonary infection. Acute pneumonia with or without empyema and lung abscess in mice with mixed infection resulted in 60 YO mortality rate, but there was only 10 YO mortality and mild pneumonia in each separate infection. Bacterial clearance of organisms, especially S. constellatus, in mixed infection was delayed. Enhancement of growth of S. constellatus was demonstrated when cultured with P. intermedia; growth was also stimulated by a culture filtrate of P. intermedia which also inhibited bactericidal activity of human neutrophils. In an examination of infectivity and bacterial clearance of S. constellatus with P. intermedia culture filtrate in vivo, there was 20 % mortality and delayed clearance of S. constellatus, although the infection was not as severe as that produced by the combination of both organisms. These results suggest that P. intermedia may act with S. constellatus in the production of pulmonary infections by stimulating its growth and suppressing bactericidal activity of the host.
This study quantified the impact of SSIs on resource consumption and confirmed significant cost variations among hospitals. These variations could not be explained by patient characteristics or infection type.
Results show that acetylcholine-induced coronary vasoconstriction in subjects with vasospastic angina correlates with hyperinsulinemia and enhanced insulin response, suggesting insulin resistance syndrome as a feature of vasospastic angina.
Strongyloidiasis is widely distributed in tropical and subtropical areas. Disseminated strongyloidiasis may develop in patients with immunodeficiencies. In the absence of early diagnosis and treatment, the prognosis of disseminated strongyloidiasis is extremely poor. We report a case of pulmonary strongyloidiasis that was successfully treated. The patient was an 83-year-old woman who had been receiving long-term oral prednisolone therapy for uveitis. The patient visited our emergency department complaining of breathing difficulties and diarrhea. A chest X-ray revealed a diffuse enhancement of interstitial shadows. A bronchoalveolar lavage (BAL) was performed, and both Gram staining and Grocott's staining revealed the presence of multiple filariform larvae of Strongyloides stercoralis in the bronchoalveolar lavage fluid (BALF). A stool examination performed at the same time also yielded S. stercoralis. The patient was diagnosed as having pulmonary strongyloidiasis and was treated with thiabendazole and ivermectin, in addition to antimicrobial agents; her respiratory symptoms and diarrhea improved, and S. stercoralis was not detected in subsequent follow-up examinations thereafter. In endemic areas of S. stercoralis, pulmonary strongyloidiasis should be considered as part of a differential diagnosis if chest imaging findings like alveolar and interstitial shadow patterns or lobar pneumonia are seen in patients with immunodeficiencies. (Internal Medicine 43: 731-736, 2004)
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