Acute-phase concentrations of soluble fibrinogen inhibit neutrophil adhesion under flow conditions in vitro through interactions with ICAM-1 and MAC-1 (CD11b/CD18).

BACKGROUND: Immobilized fibrinogen and fibrin facilitate leukocyte adhesion, as they are potent ligands for leukocyte MAC-1 (CD11b/CD18). However, fibrinogen in its soluble form also binds to MAC-1, albeit with low affinity. The level of soluble fibrinogen is increased during chronic and acute inflammation, but the function of this increase is unknown. OBJECTIVES: To study the effect of soluble fibrinogen in concentrations found in severe acute inflammation on leukocyte adhesion. METHODS: Isolated leukocytes and soluble fibrinogen were studied in various in vitro settings under static and under flow conditions. RESULTS: Soluble fibrinogen functioned as a natural antagonist of neutrophil functions that are dependent on MAC-1, such as the respiratory burst induced by unopsonized zymosan and adhesion to ICAM-1 and heparin. In addition, soluble fibrinogen inhibited lymphocyte function-associated antigen 1-dependent lymphocyte binding to ICAM-1 through a direct interaction with ICAM-1. Soluble fibrinogen reduced MAC-1-dependent binding of interleukin-8-activated neutrophils to ICAM-1-expressing cells under flow conditions. Importantly soluble fibrinogen in acute-phase concentrations (4-10 mg mL(-1) ) dose-dependently reduced neutrophil firm adhesion to tumor necrosis factor-α-activated endothelium to 40% under flow conditions. CONCLUSIONS: We propose a model in which the increased circulating concentrations of soluble fibrinogen found during the acute-phase response can act as a natural antagonist of leukocyte recruitment, and therefore might contribute to the resolution of inflammation.

[Retrospective application of the performance indicator 'hip fracture: operate within 24 hours' in 217 patients treated at the University Medical Centre Utrecht in 2000-2003: reduction in postoperative pneumonia but not mortality]. / De prestatie-indicator 'heupfractuur: opereren binnen 24 uur' retrospectief toegepast bij 217 patiënten in het universitair medisch centrum utrecht, 2000-2003: postoperatiefminder vaak pneumonie, maar niet minder sterfte.

OBJECTIVE: To evaluate whether patients with hip fracture who undergo surgery within 24 hours--which has been propagated as an indicator of quality care--is associated with a reduced risk of mortality and complications, compared with later surgery. DESIGN: Retrospective status study based on a prospectively designed electronic medical record. METHOD: Data were collected on patients aged > or =60 years who were admitted to the University Medical Centre Utrecht, the Netherlands, between 1 January 2000 and 31 December 2003 for hip fracture. Outcomes were compared in patients who underwent surgery within 24 hours and those who underwent surgery after more than 24 hours. The primary outcome measure was mortality (in-hospital, after 3 months, 12 year and 3 years after discharge). Secondary outcome measures were postoperative complications, postoperative duration ofhospital stay and admission to long-term care facilities. We corrected for age, gender and pre-existing comorbidity. RESULTS: A total of 217 patients were included. In the 150 patients who underwent surgery within 24 hours, the mean age was 80.5 years, 75% were female and 28% were class III or IV according to the American Society of Anesthesiologists (ASA). In the 67 patients who underwent surgery after more than 24 hours, the mean age was 80.9 years, 82% were female, and 49% were ASA class III or IV. After correcting for published risk factors, there was no relationship between the timing of surgery and mortality. Fewer patients treated within 24 hours developed pneumonia postoperatively. In this study population, the only risk factor for mortality was the preoperative condition of the patient. CONCLUSION: Postoperative pneumonia occurred less frequently in patients with hip fracture who underwent surgery within 24 hours. Postoperative mortality was related to poor patient condition but not the timing of surgery. Early surgery should be avoided in patients with severe comorbidity who are not optimally prepared for surgery.

[Diagnostic image (304). A woman with microcalcifications at mammography]. / Diagnose in beeld (304). Een vrouw met microcalcificaties op het mammogram.

A 72-year-old woman had temporary microcalcifications in the nipple area at mammography, possibly caused by skin care products.