Non-specific activation of human eosinophil functional responses by vasoactive intestinal peptide

Novel association between vasoactive intestinal peptide and CRTH2 receptor in recruiting eosinophils: a possible biochemical mechanism for allergic eosinophilic inflammation of the airways

We explored the relation between vasoactive intestinal peptide (VIP), CRTH2, and eosinophil recruitment. It is shown that CRTH2 expression by eosinophils from allergic rhinitis (AR) patients and eosinophil cell line (Eol-1 cells) was up-regulated by VIP treatment. This was functional and resulted in exaggerated migratory response of cells against PGD2. Nasal challenge of AR patients resulted in a significant increase of VIP contents in nasal secretion (ELISA), and the immunohistochemical studies of allergic nasal tissues showed significant expression of VIP in association with intense eosinophil recruitment. Biochemical assays showed that VIP-induced eosinophil chemotaxis from AR patients and Eol-1 cells was mediated through the CRTH2 receptor. Cell migration against VIP was sensitive to protein kinase C (PKC) and protein kinase A (PKA) inhibition but not to tyrosine kinase or p38 MAPK inhibition or calcium chelation. Western blot demonstrated a novel CRTH2-mediated cytosol-to-membrane translocation of PKC-ε, PKC-δ, and PKA-α, -γ, and -IIαreg in Eol-1 cells upon stimulation with VIP. Confocal images and FACS demonstrated a strong association and co-localization between VIP peptide and CRTH2 molecules. Further, VIP induced PGD2 secretion from eosinophils. Our results demonstrate the first evidence of association between VIP and CRTH2 in recruiting eosinophils.

Telemedicine: Benefits to advanced practice nursing and the communities they serve

PURPOSE

To review the use of telemedicine in a variety of advanced nursing practice settings, its contribution in expanding the service and role of the nurse practitioner, and the regulatory issues of reimbursement and licensure.

DATA SOURCES

Literature review of relevant journals, research articles, case examples, and web searches.

CONCLUSIONS

Although telemedicine has been utilized for many years, it has historically been used primarily by physicians. In recent years, telemedicine has been demonstrating its growing potential in advanced nursing practice in terms of economy, efficacy, and quality of care. When used appropriately, telemedicine complements advanced nursing practice in cost-effective ways and improves healthcare access to the populations served.

IMPLICATIONS FOR PRACTICE

Incorporating telemedicine into the advanced nursing practice can be rewarding for both clinicians and their patients. Because of the high variability that exists among state regulations and payer reimbursements, clinicians are advised to verify their respective Board of Nursing Examiners, State, and payers' policies prior to investing in the establishment of telemedicine in practice.