Redesigning clinical office practices to improve performance levels in an individual practice association model HMO

Independent Health, a large health maintenance organization in western New York, is participating in a national initiative to redesign the way healthcare is delivered in the clinical office setting. The Idealized Design of Clinical Office Practices (IDCOP) project aims to initiate profound change in the ways physicians deliver care and treatment in the office; the focus is on demonstrating improvements in access to care, patient care, patient and staff satisfaction, and financial performance. Two clinical prototype test sites have successfully implemented an "open access policy," which enables most patients to see their physician on the day an appointment is requested. The two test sites also found improved clinical indicators (for diabetes and coronary heart disease) that positively affected the health of patients; reduced waiting time, enriching the overall experience of the office visit; and improved patient and staff satisfaction with the operational and care delivery modifications. This article describes the findings of the IDCOP initiative at Independent Health.

Mapping of the extracellular binding regions of the human interleukin-8 type B receptor

This study was undertaken to define the regions of the human interleukin-8 type B receptor (IL8RB) which are critical for binding the ligands interleukin-8, NAP-2 and GRO alpha. Peptides corresponding to the N-terminus region and the first extracellular loop of the receptor demonstrated statistically significant (p = 0.001) inhibition of IL-8 control binding levels (inhibition levels of 73.0 +/- 5.1% and 89.9 +/- 2.2% respectively). In contrast, NAP-2 binding was inhibited only by the peptide representing the first extracellular loop (63.2 +/- 2.3%), while GRO alpha binding was inhibited by portions of the N-terminus (49.7 +/- 14.9% and 41.8 +/- 14.9%), but not the first extracellular loop. We suggest that: a) the chemokine receptor IL8RB, known to bind three related ligands with high affinity, seems to do so via distinct contact points and b.) the first extracellular loop is significant in the binding event.

Structural and functional characterization of the human formyl peptide receptor ligand-binding region

The formyl peptide (N-formyl-1-methionyl-1-leucyl-1-phenylalanine [FMLP]) receptor is involved in the activation of neutrophils and their subsequent response to chemotactic N-formylated peptides. Recently, we found that the first extracellular loop closest to the N-terminal end of the FMLP receptor exhibited the strongest ligand binding compared with that shown by other extracellular regions. By constructing amino acid substitutional variants of this domain, we have determined that residues Arg-84 and Lys-85 on this loop play major roles in ligand-binding activity. Furthermore, random rearrangement of the residues of this receptor region demonstrated that the position of these charged amino acids did not affect their involvement in ligand binding, although their presence was essential for this binding to occur. We propose that the portion of the first N-terminal extracellular loop of the FMLP receptor containing residues Arg-84 and Lys-85 contributes significantly to the active site in ligand-receptor binding. We further propose that this binding is not dependent on defined structure but rather that these charged moieties may function as important "contacts" in receptor-ligand interactions.

Porphyromonas gingivalis trypsin-like protease: a possible natural ligand for the neutrophil formyl peptide receptor

Porphyromonous gingivalis is a periodontopathic Gram-negative anaerobe associated with chronic adult periodontitis. P. gingivalis proteases are considered important virulence factors in the pathogenesis of periodontal diseases. In addition, defective bactericidal activity of neutrophils has also been observed in periodontitis. In this report we describe the effects of trypsin-like protease(s) secreted from P. gingivalis cells on the ligand binding of FMLP receptor on neutrophils. It was observed that trypsin-like protease(s) from P. gingivalis stimulate neutrophils by means of superoxide anion production. Subsequently, the proteases were found to cleave the FMLP receptor protein as evident by direct labeling of the FMLP receptor molecule. These results suggest that trypsin-like protease(s) secreted from P. gingivalis cells contribute to attenuate the bactericidal activity of neutrophils by cleaving the polypeptide chain of the FMLP receptor molecule. The finding that neutrophils after the incubation with P. gingivalis released protease preparation fail to respond to further stimulation by FMLP suggests that P. gingivalis trypsin-like protease(s) may be a possible ligand for the FMLP receptor.

Recombinant expression and partial characterization of the human formyl peptide receptor

FMLP-receptor DNA was expressed in Escherichia coli. The expressed product could specifically bind FMLP. This is the first-reported expression of a functional FMLP receptor in Escherichia coli. We confirm that receptor glycosylation is not essential for ligand binding. A deletion mutant did not bind FMLP, suggesting that the deleted portion plays a role in ligand binding.

Identification of a gene encoding for the human formyl peptide receptor

The neutrophil FMLP receptor is involved in activation and subsequent response to certain chemotactic stimuli. The normal receptor has been reported to consist of several components, ranging in size from 43-94 kDa, and to contain both high and low affinity states. However, limited information is available on the gene/s which encode for the receptor. In this study, we have generated oligonucleotide probes derived from a published cDNA sequence encoding for one of the components of the FMLP receptor, and used these probes to amplify genomic DNA from HL-60 cells as well as normal human neutrophils, using the polymerase chain reaction. Such procedure resulted in the amplification of a single, approximately 1 kb fragment of genomic DNA identical in sequence to the cDNA described in the literature for one of the isoforms of the receptor. This finding supports the notion that the human FMLP receptor is encoded by at least one, intronless gene.

Isolation and partial characterization of the formyl peptide receptor components on human neutrophils

The receptor for formylated peptides such as FMLP has been reported to consist of glycoprotein components ranging from 24-95 kDa, and to exhibit both high and low affinity for ligand. Controversy exists on the molecular size and number of these components, and whether the different affinities represent distinct ligand binding sites. In this study, the receptor was found to be comprised of components, of 94, 68, and approximately 40 kDa molecular size. Competitive binding inhibition experiments showed that FMLP bound to the components in the following order from highest to lowest affinity: 68 kDa greater than approximately 40 kDa greater than 94 kDa. Our findings suggest that the FMLP receptor of human neutrophils contains at least three components, and that each component has a different affinity for FMLP.