The surface tensions of amine-, hydroxyl-, and methyl-terminated poly(dimethylsiloxane) (PDMS) oligomers with molecular weights ranging from 1000 to 75 000 are measured by pendant drop tensiometry. The surface tension increases with molecular weight for the methyl-terminated polymers, decreases with molecular weight for the amine-terminated polymers, and is nearly independent of molecular weight for the hydroxyl-terminated polymers. This behavior is attributed to differences in surface tension of the end groups and the repeat unit of the chain ( . -

Cystic fibrosis is characterized in the lungs by neutrophil-dominated inflammation mediated significantly by neutrophil elastase (NE). Previous work has shown that

No abstract

Background Plasma homocysteine levels are modulated by nutritional and genetic factors, among which is the enzyme methylenetetrahydrofolate reductase (MTHFR). A common defective (thermolabile) variant of this enzyme is causally associated with elevated plasma homocysteine, itself an independent risk factor for coronary heart disease.

No abstract

No abstract

No abstract

Protease-antiprotease balance in 17 patients with unilateral community-acquired pneumonia (CAP) was characterized (day 6+/-0.8). Levels and activities of alpha-1 antitrypsin (A1AT), secretory leucoprotease inhibitor (SLPI), and neutrophil elastase (NE) were quantified. Lobes were designated as infected or uninvolved according to the presence of an infiltrate on chest radiograph. NE levels in infected lobes were higher than those in uninvolved lobes, and NE levels were significantly elevated in both, compared with that in control lobes (n=18; P<.01). A1AT and SLPI levels were similar in infected and uninvolved lobes and were significantly elevated, compared with those in control lobes (P<.05 and P<.005, respectively). Anti-NE activity in infected lobes was less than that in control or uninvolved lobes (P<.05); values in the latter 2 were similar. Free NE was detected in 7 of the infected samples, indicating that anti-NE capacity is impaired. Both A1AT and SLPI were cleaved or complexed in infected lobes, and A1AT was oxidized in infected lobes. We conclude that mean elastase levels are increased and that mean anti-elastase capacity is decreased in pneumonic lobes.