| 1. |
- Sandstrom, T, et al.
(author)
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Inflammatory cell response in bronchoalveolar lavage fluid after nitrogen dioxide exposure of healthy subjects: a dose-response study
- 1991
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In: European Respiratory Journal. - 1399-3003. ; 4:3, s. 332-339
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Journal article (peer-reviewed)abstract
- The combination of environmental chamber exposure and bronchoalveolar lavage (BAL) was used to study the effects of the common air pollutant nitrogen dioxide (NO2). Eighteen healthy nonsmokers were exposed to NO2 during 20 min in an exposure chamber during light bicycle ergometer work. All subjects were examined with BAL at least 3 wks before exposure, as a reference. The subjects were re-examined with BAL, in groups of eight, 24 h after exposure to 4, 7 and 10 mg NO2.m.3 (2.25, 4.0 and 5.5 ppm), respectively. An inflammatory cell response was found after exposure to all concentrations. An increase in the number of lymphocytes in BAL fluid was observed after 7 and 10 mg.m.3 (p less than 0.05 and 0.02, respectively). An increase in the number of mast cells, that appears to be dose-dependent, was found after exposure to all concentrations. The proportion of lysozyme positive alveolar macrophages was elevated after exposure to 7 mg.m.3. The inflammatory mediators fibronectin, hyaluronan, angiotensin converting enzyme (ACE) and beta 2-microglobulin were unchanged by exposure. Due to the findings of inflammatory cell changes far below the peak exposure limits for work places in industrialized countries, 9-18 mg.m.3, the safety of these limits is questioned. Studies are in progress in our laboratory using BAL to evaluate the effects of repeated NO2 exposure.
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| 2. |
- Sandberg, A.-S., et al.
(author)
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High dietary calcium level decreases colonic phytate degradation in pigs fed a rapeseed diet
- 1993
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In: Journal of Nutrition. - 0022-3166 .- 1541-6100. ; 123:3, s. 559-566
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Journal article (peer-reviewed)abstract
- The degradation of phytate (inositol hexaphosphate) in rapeseed meal diet not containing phytase activity was studied in 15 growing ileum-fistulated pigs. Stomach and small intestinal degradation and total gastrointestinal degradation were compared. The effect of addition of calcium carbonate to the rapeseed meal diet at two levels (9.2 and 18.5 g/kg diet) was investigated. A commercial barley-wheat-soybean diet with intrinsic phytase activity was used as reference. Phytate and its hydrolysis products in diets, ileal digesta and feces were determined by HPLC ion-pair chromatography. Hydrolysis of phytate in the stomach and small intestine was 35-45% in pigs fed the rapeseed meal diet independent of calcium addition, and 65% in pigs fed the reference diet. Total gastrointestinal degradation of phytate in pigs fed the rapeseed diet was 97, 77 and 42% (P < 0.001) when calcium intakes were 4.5, 9.9 and 15 g/d, respectively; total gastrointestinal degradation was 72% in pigs fed the reference diet. The intestinal phytate degradation pattern, when rapeseed diet was fed, indicated the activity of an unspecific phosphatase, whereas that of the reference diet indicated intrinsic dietary phytase activity. We conclude that dietary supplementation of calcium carbonate decreases the phytate degradation in the colon of pigs, but not in the stomach and small intestine.
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| 3. |
- Sandstrom, T, et al.
(author)
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Effects of repeated exposure to 4 ppm nitrogen dioxide on bronchoalveolar lymphocyte subsets and macrophages in healthy men
- 1992
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In: European Respiratory Journal. - 1399-3003. ; 5:9, s. 1092-1096
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Journal article (peer-reviewed)abstract
- Following the basal descriptive studies of the bronchoalveolar inflammatory cell response induced by single exposure with nitrogen dioxide (NO2) in man, it was considered important to clarify the cell response to repeated exposure with NO2. This investigation was, therefore, undertaken with bronchoalveolar lavage (BAL) 3 weeks before and 24 h after six repeated exposures with 4 ppm NO2 (7 mg.m-3) in ten healthy volunteers. The exposures were performed during 20 min and every second day. Analysis of the recovered BAL fluid demonstrated that repeated exposures to NO2 caused a lung cell response different from that reported after a single exposure. Amounts of lavaged alveolar macrophages, B-cells, and natural killer (NK)-cells were decreased and the T-helper-inducer/cytotoxic-suppressor cell ratio was altered, but there was no lymphocytosis or mastocytosis as after single exposure. Lymphocyte numbers in peripheral blood were reduced after exposure. These results suggest that repeated exposure with NO2 adversely affects the immune defence. This could contribute to the increased susceptibility to airway infections reported to be associated with NO2 exposure.
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| 4. |
- Sandstrom, T, et al.
(author)
-
Lipopolysaccharide (LPS) inhalation in healthy subjects increases neutrophils, lymphocytes and fibronectin levels in bronchoalveolar lavage fluid
- 1992
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In: European Respiratory Journal. - 1399-3003. ; 5:8, s. 992-996
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Journal article (peer-reviewed)abstract
- Bacterial endotoxin has been suggested as responsible for the development of subjective symptoms and transient or chronic lung function impairment seen after exposure to organic dusts in cotton mills, poultry houses, swine confinement buildings and saw mills. Animal experiments have demonstrated bronchoalveolar neutrophilia being the most prominent cell response in animals following bacterial lipopolysaccharide (LPS) inhalation. The present study was conducted to obtain information on some aspects of the early inflammatory response to inhaled LPS in man. Eight healthy nonsmoking subjects, 23-27 yrs old, underwent bronchoalveolar lavage (BAL), 3 h after a provocation test with 100 micrograms LPS from E. coli dissolved in 2 ml isotonic NaCl. The solution was aerosolized with a jet nebulizer and inhaled. The calculated dose delivered to the lung was approximately 25 micrograms, which equals exposure in some occupational settings. The BAL data for each individual subject were compared with data from a control BAL performed at least 6 weeks prior to the LPS challenge. The major cellular response to LPS, reflected in BAL fluid, was an approximately hundredfold increase in neutrophils. The total number of lymphocytes was on average tripled. The alveolar macrophage phagocytosis of opsonized yeast particles in vitro was significantly reduced. A further indicator of an ongoing inflammation was an increase in fibronectin. No changes were seen in the levels of BAL albumin, indicating that the elevated level of fibronectin could not be explained by an increased permeability, but rather by a local production. The results correspond with data from animal studies and further supports the hypothesis that bacterial LPS is important in the pulmonary reaction induced by organic dusts.
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