IL-8 concentration in coronary sinus blood during early coronary reperfusion after ischemic arrest

Phenotypic analysis of chemokine-driven actin reorganization in primary human neutrophils

The chemokine-driven activation of CXC-type chemokine receptors 1/2 (CXCR1/2) and the subsequent reorganization of the neutrophilic actin are early key events in the induction of neutrophil migration toward centers of inflammation. In this study, an image analysis algorithm was developed to detect subtle chemokine-induced changes in the actin cytoskeleton of primary human neutrophils. By this means, a discrete early step of neutrophil activation was dissected that could be initiated by concentrations of growth-related oncogen α (Gro-α) or interleukin-8 (IL-8) just above their resting-state plasma levels. The associated half-maximal effective concentration (EC50) values for Gro-α and IL-8 of 8 and 22 pM, respectively, are between two and three orders of magnitude below the so-far reported EC50 values of these chemokines for the induction of neutrophilic calcium release, integrin expression, degranulation, and receptor internalization. Sch527123, a known inhibitor of CXCR2 (KD=49 pM) and with a lower potency/affinity also of CXCR1 (KD=3.9 nM), antagonized actin remodeling with half-maximal inhibitory concentration (IC50) values of 400 pM for the CXCR2-specific agonist Gro-α and of 36 nM for the CXCR1/2-promiscuous agonist IL-8. This observation indicates that the here-described early step of chemokine-driven actin reorganization is modulated by both CXCR1 and CXCR2. Thus, the imaging-based assay format, as developed in this work, may be employed in a phenotypic screening campaign to identify inhibitors of an early step in CXCR1/2-induced neutrophilic chemotaxis.

Selective cyclooxygenase-2 inhibition protects against myocardial damage in experimental acute ischemia

BACKGROUND

Acute myocardial infarction is associated with tissue inflammation. Early coronary reperfusion clearly improves the outcome but may help propagate the inflammatory response and enhance tissue damage. Cyclooxygenase-2 is an enzyme that catalyzes the initial step in the formation of inflammatory prostaglandins from arachidonic acid. Cyclooxygenase-2 levels are increased when ischemic cardiac events occur. The overall function of COX-2 in the inflammatory process generated by myocardial ischemic damage has not yet been elucidated.

GOAL

The objective of this study was to determine whether a selective cyclooxygenase-2 inhibitor (rofecoxib) could alter the evolution of acute myocardial infarction after reperfusion.

METHODS AND RESULTS

This study was performed with 48 mongrel dogs divided into two groups: controls and those treated with the drug. All animals were prepared for left anterior descending coronary artery occlusion. The dogs then underwent 180 minutes of coronary occlusion, followed by 30 minutes of reperfusion. Blood samples were collected from the venous sinus immediately before coronary occlusion and after 30 minutes of reperfusion for measurements of CPK-MB, CPK-MBm and troponin I. During the experiment we observed the mean blood pressure, heart rate and coronary flow. The coronary flow and heart rate did not change, but in the control group, there was blood pressure instability, in addition to maximal levels of CPK-MB post-infarction. The same results were observed for CPK-MBm and troponin I.

CONCLUSION

In a canine model of myocardial ischemia-reperfusion, selective inhibition of Cyclooxygenase-2 with rofecoxib was not associated with early detrimental effects on the hemodynamic profile or the gross extent of infarction; in fact, it may be beneficial by limiting cell necrosis.

Radial artery in myocardial revascularization

In the past decade, the use of the radial artery as a coronary artery bypass graft has been revitalized. However, there has been controversy regarding harvest techniques, antispasm protocols, and selection of target vessels. It is widely accepted that the patency of radial-artery grafts depends on the severity of native-vessel stenosis. Thus, radial artery grafts should be preferentially used for target vessels with high-grade (>75% stenosis) lesions. In this review article, we analyzed the current status of radial artery grafts as a coronary bypass conduit based on our personal experience and recently published literature data.

The effects of propofol on neutrophil function, lipid peroxidation and inflammatory response during elective coronary artery bypass grafting in patients with impaired ventricular function

BACKGROUND

Coronary artery bypass grafting (CABG) with cardiopulmonary bypass elicits a potent reperfusion injury and inflammatory response, more intense in patients with impaired myocardial function. Propofol has antioxidant properties which may attenuate such a response.

METHODS

In total, 27 patients with impaired left ventricular function undergoing CABG were randomly allocated to receive either target-controlled infusion propofol (P) or saline (S) immediately before aortic cross-clamp release until 4 h after reperfusion. Troponin-I, Urinary 8-epi PGF-2alpha isoprostane, coronary sinus and systemic malondialdehyde concentrations, Interleukin-6 (IL-6), -8 and -10 concentrations and leucocytes function studies (neutrophil respiratory burst, phagocytosis, CD-11b and CD-18 expression) were measured.

RESULTS

Propofol decreased MDA coronary sinus concentration at 1, 3 and 5 min after reperfusion (P<0.01); 60 min after reperfusion a significant difference between the two groups in systemic MDA concentrations was also seen. IL-6 concentration increases were significantly greater in Group S than Group P, 4 h after reperfusion [1118 (1333) pg ml(-1) vs 228 (105) pg ml(-1), P<0.01]. Serum IL-8 concentrations did not increase significantly in either group. Compared with baseline values IL-10 concentrations decreased after reperfusion but the values were higher in the propofol group than in the control group [22 (16) vs 11 (4) pg ml(-1), P<0.05]. No difference in leucocyte function or urinary isoprostane concentrations was demonstrated.

CONCLUSION

Propofol attenuates free-radical-mediated lipid peroxidation and systemic inflammation in patients with impaired myocardial function undergoing CABG.

Pulmonary Alveolar Microlithiasis

Pulmonary alveolar microlithiasis (PAM) is a rare idiopathic disease with unknown etiology and pathogenesis. The present work updates the world literature on PAM up to the end of 2001 by means of a full review, including minor reports in local languages (not English). Excluding secondary cases, a total of 424 cases have been reported worldwide, 269 of which were sporadic and showed a prevalence of the male sex and 155 of which were familial cases and prevalently affected the female sex. The highest number of cases has been reported in Europe, followed by Asia, especially Asia Minor, while the single nations with the greatest number of reported cases are Turkey, then Italy and the USA. The salient clinical features of PAM as described in the literature are analyzed: family history, clinical course, association with other diseases, presence of calcification in other organs. In the first cases, reported in the 60s and 70s, diagnosis was primarily made at autopsy, whereas nowadays diagnostic investigation is made above all by transbronchial biopsy and bronchoalveolar lavage. Radiological imaging is sufficient in cases where other family members are known to be affected, diagnosed by means of invasive techniques. There is no known treatment to date, while lung transplantation is performed in the severest cases. A better knowledge of the epidemiological characteristics of this rare disease could help to diagnose a larger number of cases and to gain insight into its etiology and pathogenesis, which are still unknown.