The characteristic variability of grazing has potential consequences for intertidal productivity and community structure, particularly as many of the underlying functional relationships are thought to be non linear. As a first approximation, it can be hypothesised that grazing is patchy over short time periods before a more uniform coverage is established over longer time scales. This prediction is supported by relatively short term observations previously made of limpet foraging. We used eight arrays of wax disks on each of four shores to test the hypothesis that grazing is patchy in the short term, but that this pattern is lost as the pattern of grazing averages out over longer time scales. Wax disk arrays were exposed for two weeks at a time for a period of six weeks in 2001 and in 2002 using the same set of disk holes each time. Grazing at the same disk location could therefore be measured over two weeks and over longer periods by averaging successive deployments. We used all three successive deployments to estimate the average grazing at each disk location over a six week period in 2001 and 2002. All six deployments were used to characterise the pattern of grazing at longer time scales. The spatial pattern of grazing in arrays was summarized using semivariogram analyses. For two-week deployments, the average standardized semivariance of grazing for disks separated by 20 cm was less than one. This pattern implies spatial autocorrelation of grazing at this scale. There was no support for the hypothesis that small scale patchiness in grazing would disappear over time. The average strength of spatial autocorrelation increased when data were integrated over longer periods. A preliminary analysis indicated that the degree of autocorrelation within arrays increased with grazing intensity at short time scales. Surface roughness disrupted autocorrelation of grazing over both short and long time scales. The persistent patchiness of grazing is likely to have implications for biofilm productivity, particularly on smoother shores. (C) 2008 Elsevier B.V. All rights reserved.

Addition of cultured and then carefully-washed bovine pulmonary artery endothelial cells (EC) decreased (p < 0.05) human neutrophil elastase activity (HNE) in vitro. HNE activity was also decreased (p < 0.05) by addition of histone or protamine treated EC. However, addition of papain or trypsin treated EC decreased HNE activity less than addition of untreated cells suggesting that a protein rather than a difference in cell surface charge was responsible. Other observations suggest that EC anti-elastolytic activity was not due to binding of antiprotease from culture media but was dependent on EC protein synthesis. First, addition of EC grown previously in serum-free media decreased HNE activity the same (p < 0.05) as addition of EC cultured in media containing serum. Second, addition of EC treated beforehand with cycloheximide decreased HNE activity less than (p < 0.05) addition of untreated control EC. We conclude that EC most likely make and have antielastolytic activity on their surfaces and speculate that EC associated anti-elastolytic activity may modulate inflammatory, repair and other biologic processes involving neutrophil elastase.

"The Pulmonary Academic “Transitional Track”: A View from Junior Faculty." American Review of Respiratory Disease, 141(6), pp. 1389–1390

Complement activation and neutrophil release of proteolytic enzymes are thought to be important in the pathogenesis of the adult respiratory distress syndrome (ARDS). Levels of both C3a and elastolytic activity are reported to be elevated in bronchoalveolar lavage (BAL) samples from patients with ARDS. The relative specificity of elevated BAL levels of complement fragments and elastase to ARDS is unknown. We compared levels of these mediators of inflammation in the BAL of patients with ARDS to those of control populations including patients with pneumonia, sepsis, and other lung diseases such as sarcoidosis and bronchitis. C3a was measured as C3a DES ARG by radioimmunoassay. Elastase levels were measured by an ELISA which detects elastase bound to its inhibitor, alpha 1-protease inhibitor, and corrected for total protein concentration. BAL levels of elastase-alpha 1-protease inhibitor complex were elevated in patients with ARDS, and in patients who are at risk for ARDS, such as those with sepsis or pneumonia. Elevated levels of C3a DES ARG were detected in some patients with ARDS, but this increase was not consistently observed when compared with the other patient groups.

Neutrophil release of elastase is postulated to contribute to the pathogonesis of the adult respiratory distress syndrome (ARDS). This enzyme cleaves basement membrane and connective tissue proteins and is able to activate other inflammatory mediators. Extracellularly released elastase is rapidly complexed with inhibitor proteins, primarily alpha1-protease inhibitor. These enzyme-inhibitor complexes diffuse or are washed into the circulation before clearance. We postulated that patients with ARDS would have elevated plasma levels of elastase complex as compared to normals. We utilized an enzyme-linked immunoassay to quantify lavels of elastase bound to alpha1-protease inhibitor in plasma samples from patients with well-established ARDS, normal laboratory workers, and hospitalized patients with chronic noninfectious disease processes. The plasma level (mean ± SD) of elastase complex in normais was 98 ± 27 ng/mL and in hospitalized patients was 110 ± 41 ng/mL. Patients with ARDS had markedly elevated plasma lovels of elastase complex, 1,018 ± 901 ng/mL as compared to controls (P < .01). Elevated plasma levels of elastase in complex with alpha1-protease inhibitor in patients with ARDS suggest that neutrophil release of this degradative enzyme may be pathophysiologically related to the pulmonary and multiorgan injury that characterizes this disorder.