Publications

The integrin alpha9beta1 has been shown to be widely expressed on smooth muscle and epithelial cells, and to mediate adhesion to the extracellular matrix proteins osteopontin and tenascin-C. We have found that the peptide sequence this integrin recognizes in tenascin-C is highly homologous to the sequence recognized by the closely related integrin alpha4beta1, in the inducible endothelial ligand, vascular cell adhesion mole-cule-1 (VCAM-1). We therefore sought to determine whether alpha9beta1 also recognizes VCAM-1, and whether any such interaction would be biologically significant. In this report, we demonstrate that alpha9beta1 mediates stable cell adhesion to recombinant VCAM-1 and to VCAM-1 induced on human umbilical vein endothelial cells by tumor necrosis factor-alpha. Furthermore, we show that alpha9beta1 is highly and selectively expressed on neutrophils and is critical for neutrophil migration on VCAM-1 and tenascin-C. Finally, alpha9beta1 and alpha4 integrins contribute to neutrophil chemotaxis across activated endothelial monolayers. These observations suggest a possible role for alpha9beta1/VCAM-1 interactions in extravasation of neutrophils at sites of acute inflammation.

OBJECTIVES

To estimate the proportion of seniors in a large health maintenance organization (HMO) who had been asked about their end-of-life care preferences (EOLCPs) by a clinician and who had completed an advance directive (AD). To examine the association of having had an EOLCP discussion and AD completion.

SUBJECTS AND METHODS

A random sample of HMO members aged 65 years or older were asked to complete a mailed survey about health and health-related issues in 1996. Data provided by 5117 seniors (80% response rate) were used to estimate the prevalence of EOLCP and AD among seniors overall and in specific risk groups. Bivariate and multiple logistic regression models were used to identify predictors of AD completion, especially having been asked about EOLCP.

RESULTS

One third of seniors reported having an AD on file with the HMO, but only 15% had talked with a clinician about EOLCP. Both having been asked about EOLCP and having an AD were positively associated with age, but not significantly associated with sex, race/ethnicity, marital status, or self-rated health status. Having been asked by a clinician about EOLCP was significantly associated with completion of an AD.

CONCLUSION

Clinicians can play an important role in increasing AD completion rates among seniors by bringing up the subject of EOLCPs.