Reduced expression of the alphabeta T-cell antigen receptor by alveolar T-cells. (49/5082)

A previous study revealed that reduced expression (modulation) of the CD3 antigen is a common characteristic of alveolar T-cells in health and disease. As CD3 molecules are noncovalently bound to T-cell antigen receptors (TCR), it was hypothesized that modulation of TCR was also a feature of alveolar T-cells. To demonstrate this, lymphocytes from bronchoalveolar lavage fluid were stained with an anti-alphabeta TCR antibody and analysed by flow cytometry. The expression of alphabeta TCR by alveolar T-cells was evaluated by calculating mean fluorescence intensity (MFI) and was compared with alphabeta TCR expression by autologous blood T-cells. As anticipated from a previous study, modulation of TCR was observed not only in healthy volunteers but also in patients with pulmonary sarcoidosis, other pulmonary diseases, and nonpulmonary diseases. There were no significant differences in MFI of alveolar T-cells among the study groups. The degree of modulation assessed by the difference of MFI between blood and alveolar T-cells was greater for CD4+ cells than for CD8+ cells owing to the higher MFI of CD4+ blood T-cells. Coculture of alveolar macrophages with blood T-cells in vitro induced partial modulation of TCR. These results demonstrate the ubiquity of modulation of T-cell receptors on alveolar T-cells and suggest, in contrast to a previous report by other investigators that it is caused by some nonantigenic mechanism possibly inherent in the alveolar milieu. The implications of this phenomenon in in vivo immune responses of the lung need to be examined.  (+info)

Emphysematous lesions, inflammation, and fibrosis in the lungs of transgenic mice overexpressing platelet-derived growth factor. (50/5082)

Because of its expression pattern and its potent effects on mesenchymal cells, platelet-derived growth factor (PDGF) has been implicated as an important factor in epithelial-mesenchymal cell interactions during normal lung development and in the pathogenesis of fibrotic lung disease. To further explore the role of PDGF in these processes, we have developed transgenic mice that express the PDGF-B gene from the lung-specific surfactant protein C (SPC) promoter. Adult SPC-PDGFB transgenic mice exhibited lung pathology characterized by enlarged airspaces, inflammation, and fibrosis. Emphysematous changes frequently occurred throughout the lung, but inflammation and fibrotic lesions were usually confined to focal areas. The severity of this phenotype varied significantly among individual mice within the same SPC-PDGFB transgenic lineage. A pathology similar to that observed in adult mice was noted in lungs from transgenic mice as young as 1 week of age. Neonatal transgenic mice exhibited enlarged saccules and thickened primary septa. Results of these studies indicated that overexpression of PDGF-B induced distinct abnormalities in the developing and adult lung and led to a complex phenotype that encompassed aspects of both emphysema and fibrotic lung disease.  (+info)

Chlamydia pneumoniae in a free-ranging giant barred frog (Mixophyes iteratus) from Australia. (51/5082)

The koala biovar of Chlamydia pneumoniae was identified in lung tissue from a sick, free-ranging giant barred frog (Mixophyes iteratus) by using electron microscopy, C. pneumoniae-specific fluorescent-antibody staining, cell culture, and sequencing of the ompA, ompB and 16S rRNA genes. This is the first report of a chlamydial strain infecting both a homeotherm and a poikilotherm and only the fourth host (in addition to humans, koalas, and horses) to be naturally infected with this species of Chlamydia. The frog had severe, chronic, mononuclear pneumonia and nonregenerative anemia and pancytopenia.  (+info)

The lung in the immunocompromised patient. Infectious complications part 2. (52/5082)

Pulmonary infections decisively contribute to morbidity and mortality in immunocompromised patients. Bacterial, mycobacterial and infections with Pneumocystis carinii have been reviewed in an article in the last issue of Respiration. In this review, viral and fungal pulmonary infections are discussed in HIV-positive patients and in patients treated with high-dose chemotherapy, stem cell or solid-organ transplantation.  (+info)

Antineutrophil cytoplasmic antibodies in diffuse panbronchiolitis. (53/5082)

BACKGROUND: There are some reports of the coexistence of chronic suppurative lung diseases such as cystic fibrosis and systemic vasculitis. Diffuse panbronchiolitis has the same characteristics as chronic recurrent sinopulmonary infection and respiratory bronchiolitis. METHODS: Serum samples from 30 patients with diffuse panbronchiolitis and 57 patients with other pulmonary diseases were tested to find the titer of myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA). RESULTS: We found MPO-ANCA positivity in 4 patients with diffuse panbronchiolitis but not in those with other pulmonary diseases. CONCLUSIONS: Our findings show that MPO-ANCA is positive in some patients with diffuse panbronchiolitis. Careful attention should be paid to the combination of chronic pulmonary infection and various vasculitis.  (+info)

Outcome following pulmonary haemorrhage in very low birthweight neonates treated with surfactant. (54/5082)

AIM: To determine if pulmonary haemorrhage after surfactant treatment increases short and long term morbidity and mortality in neonates weighing <1500 g at birth. METHODS: Neonates weighing <1500 g at birth who developed pulmonary haemorrhage after surfactant treatment were identified from a database. Based on the change in FIO2, pulmonary haemorrhage was classified as mild, moderate, or severe. Controls were matched for birthweight, gestational age, Apgar scores and hospital. Chronic lung disease (CLD) was defined as the need for supplemental oxygen at 36 weeks of corrected gestational age. RESULTS: From January 1990 to May 1994, 94 of 787 (11.9%) neonates treated with surfactant developed pulmonary haemorrhage. Ten were excluded because of incomplete data or lack of controls. Eighty four were included for further analysis; two acceptable matches were found in 75, while only one match was possible in nine. For the pulmonary haemorrhage group, the mean (SD) birthweight was 917 (238) g, gestational age 27 (1.9) weeks. Pulmonary haemorrhage was severe in 39 (46%), moderate in 22 (26%), and mild in 23 (27%). Moderate and severe pulmonary haemorrhage were associated with chronic lung disease or death, OR 4.4 (confidence interval 1.3-15.7) and OR 7.8 (CI 2.6-28), respectively, while mild pulmonary haemorrhage was not, OR 1.8 (CI 0.55-5.8). pulmonary haemorrhage was associated with major intraventricular haemorrhage (IVH), OR 3.1 (CI 1.5-6.4), but not with minor IVH, OR 1.3 (CI 0.6-2. 6). In the survivors who could be assessed at >/=2 years, the differences in neurodevelopmental outcome among the two groups were not significant. CONCLUSIONS: In neonates treated with surfactant moderate and severe pulmonary haemorrhage is associated with an increased risk of death and short term morbidity. Pulmonary haemorrhage does not seem to be associated with increased long term morbidity.  (+info)

Association of air pollution with daily GP consultations for asthma and other lower respiratory conditions in London. (55/5082)

BACKGROUND: Very few published studies have looked at the effects of air pollution on health in the primary care setting. As part of a large study to examine the association between air pollution and a number of health outcomes, the relationship between daily GP consultations for asthma and other lower respiratory diseases (LRD) and air pollution in London was investigated. METHODS: Time-series analysis of daily numbers of GP consultations controlling for time trends, seasonal factors, day of week cycles, influenza, weather, pollen levels, and serial correlation was performed. Consultation data were available from between 268 718 and 295 740 registered patients from 45-47 London practices contributing to the General Practice Research Database during 1992-4. RESULTS: Positive associations, weakly significant and consistent across lags, were observed between asthma consultations and nitrogen dioxide (NO2) and carbon monoxide (CO) in children and particulate matter of less than 10 microm in diameter (PM10) in adults, and between other LRD consultations and sulphur dioxide (SO2) in children. A consistently negative association with ozone in children was observed in both disease categories. The effect estimates of most pollutants were much larger when analysed separately by season, particularly in the children: percentage change in asthma consultations during the warm season (April-September) for a 10-90th percentile increase in 24 hour NO2 lagged by one day = 13.2% (95% CI 5.6 to 21.3), with CO = 11.4% (95% CI 3.3 to 20.0), and with SO2 = 9.0% (95% CI 2.2 to 16.2). In adults the only association consistent over different lag periods was with PM10 = 9.2% (3.7 to 15.1). The associations of pollution and consultations for LRD were increased mainly in the winter months: percentage change in consultations by children in winter with NO2 = 7.2% (95% CI 2.8 to 11.6), CO = 6.2% (95% CI 2.3 to 10.2), and SO2 = 5.8% (95% CI 1.6 to 10.2). CONCLUSIONS: There are associations between air pollution and daily consultations for asthma and other lower respiratory disease in London. The most significant associations were observed in children and the most important pollutants were NO2, CO, and SO2. In adults the only consistent association was with PM10.  (+info)

Vitamin A supplementation for extremely-low-birth-weight infants. National Institute of Child Health and Human Development Neonatal Research Network. (56/5082)

BACKGROUND: Vitamin A supplementation may reduce the risk of chronic lung disease and sepsis in extremely-low-birth-weight infants. The results of our pilot study suggested that a dose of 5000 IU administered intramuscularly three times per week for four weeks was more effective than the lower doses given in past trials. METHODS: We performed a multicenter, blinded, randomized trial to assess the effectiveness and safety of this regimen as compared with sham treatment in 807 infants in need of respiratory support 24 hours after birth. The mean birth weight was 770 g in the vitamin A group and 769 g in the control group, and the respective gestational ages were 26.8 and 26.7 weeks. RESULTS: By 36 weeks' postmenstrual age, 59 of the 405 infants (15 percent) in the vitamin A group and 55 of the 402 infants (14 percent) in the control group had died. The primary outcome - death or chronic lung disease at 36 weeks' postmenstrual age - occurred in significantly fewer infants in the vitamin A group than in the control group (55 percent vs. 62 percent; relative risk, 0.89; 95 percent confidence interval, 0.80 to 0.99). Overall, 1 additional infant survived without chronic lung disease for every 14 to 15 infants who received vitamin A supplements. The proportions of infants in the vitamin A group and the control group who had signs of potential vitamin A toxicity were similar. The proportion of infants with serum retinol values below 20 microg per deciliter (0.70 micromol per liter) was lower in the vitamin A group than in the control group (25 percent vs. 54 percent, P<0.001). CONCLUSIONS: Intramuscular administration of 5000 IU of vitamin A three times per week for four weeks reduced biochemical evidence of vitamin A deficiency and slightly decreased the risk of chronic lung disease in extremely-low-birth-weight infants.  (+info)