Search

Gastro-esophageal reflux and related pulmonary bile acid aspiration were prospectively investigated as possible contributors to postlung transplant bronchiolitis obliterans syndrome (BOS). We also studied the impact of aspiration on pulmonary surfactant collectin proteins SP-A and SP-D and on surfactant phospholipids—all important components of innate immunity in the lung. Proximal and distal esophageal 24-h pH testing and broncho-alveolar lavage fluid (BALF) bile acid assays were performed prospectively at 3-month posttransplant in 50 patients. BALF was also assayed for SP-A, SP-D and phospholipids expressed as ratio to total lipids: phosphatidylcholine; dipalmitoylphosphatidylcholine; phosphatidylglycerol (PG); phosphatidylinositol; sphingomyelin (SM) and lysophosphatidylcholine. Actuarial freedom from BOS was assessed.

On exposure to a realistic ozone dose, an enhanced mRNA accumulation for phenyalanine ammonia-lyase (EC 4.3.1.5), naringenin–chalcone synthase [malonyl–CoA:4-coumaroyl–CoA malonyltransferase (cyclising); EC 2.3.1.74] and chalcone isomerase [flavanone lyase (decyclising); EC 5.5.1.6] genes, whose products are involved in the biosynthesis of phenylpropanoid molecules, flavonoid pigments and isoflavonoid phytoalexins, was observed in primary leaves of the bean (Phaseolus vulgaris L.) cv. Pinto. This cultivar was previously known to be ozone-sensitive on the basis of the appearance of macroscopic foliar injury, but not in coeval leaves of the bean cv. Groffy, known to be ozone-resistant on the basis of the aforementioned criterion. Distinct time patterns were observed in Pinto leaves for the ozone-dependent enhanced mRNA accumulation for the aforementioned genes, which in all cases largely preceded the appearance of visible injury symptoms. These results lend support to the view of ozone as an abiotic elicitor of plant defence responses. By analogy with other case studies, it is also suggested that proneness to develop visible ozone symptoms might rest on a sequence of molecular events similar to that leading to the hypersensitive response during plant–pathogen incompatible interactions. Keywords: chalcone isomerase, chalcone synthase, ozone, Phaseolus vulgaris L., phenylalanine ammonia-lyase.

Unfolding behaviour of different allelic variants of high Mrglutenin subunits has been studied by transverse urea gradient gel electrophoresis, a system in which a gradient of urea (from 0 to 8 M) is generated perpendicularly to the direction of migration. A different unfolding pattern is observed between x- and y-type subunits. The former type of subunits generally present a broad unfolding pattern without any clear transition, as urea concentration increases, suggesting the existence of several conformational intermediates. On the contrary most of the y-type subunits present an unfolding pattern showing an abrupt decrease in mobility, with a single inflection point at the midpoint of the transition indicative of a protein unfolding in a single, cooperative, two-state transition. Native and bacterial expressed subunits, differing for the size of the repetitive domain, were used to assess the role of variation in size of such region on unfolding behaviour. Free energy values associated to unfolding process were calculated for most of the y-type subunits presenting a two state transition. In particular, different values were found for subunit Dy10 and Dy12, with the former being larger than the latter, suggesting a different stability of the two subunits. Possible implications for qualitative differences associated to allelic subunits are also discussed.

We report the construction of modified highMrglutenin subunit genes with variable lengths of the repetitive domain and their expression inEscherichia coli. The modified glutenin subunits showed anomalously slow migration by SDS–PAGE characteristic of these polypeptides. Changes in the size of the repetitive domain correlated with both the migration behaviour on SDS–PAGE and with the surface hydrophobicities of the polypeptides measured by RP–HPLC. These constructs made it possible to obtain direct evidence for the first time that the anomalous electrophoretic mobilities of highMrglutenin subunits in SDS–PAGE, compared with globular proteins, are mainly due to the repetitive domain. These constructs should be useful for establishing the role of the repetitive domain of highMrglutenin subunits in determining the viscoelastic properties of dough. They also offer the possibility of creating new genetic variability for wheat improvement.