Relationship of lipoprotein-associated phospholipase A2 and oxidized low density lipoprotein in carotid atherosclerosis.

Plasma levels of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) and oxidized low density lipoprotein (oxLDL) have been identified as risk factors for cardiovascular disease. Lp-PLA(2) is the sole enzyme responsible for the hydrolysis of oxidized phospholipids on LDL particles in atherosclerotic plaques. We have studied the relationship between Lp-PLA(2) and oxLDL in carotid endarterectomy (CEA) tissues and in matched plasmas. In extracts from CEA anatomical segments, the levels of oxLDL were significantly associated with the levels of Lp-PLA(2) protein (r = 0.497) and activity (r = 0.615). OxLDL and Lp-PLA(2) mass/activity were most abundant in the carotid bifurcation and internal segments where plaque was most abundant. In extracts from CEA atheroma, the levels of oxLDL and Lp-PLA(2) were significantly correlated (r = 0.634). In matched plasma and atheroma extracts, the levels of Lp-PLA(2) were negatively correlated (r = - 0.578). The ratio of Lp-PLA(2) to oxLDL was higher in atheromatous tissue (277:1) than in normal tissue (135:1) and plasma (13:1). Immunohistochemical experiments indicated that in plaques, oxLDL and Lp-PLA(2) existed in overlapping but distinctly different distribution. Fluorescence microscopy showed both oxLDL and Lp-PLA(2) epitopes on the same LDL particle in plasma but not in plaque. These results suggest that the relationship between Lp-PLA(2) and oxLDL in the atherosclerotic plaque is different from that in the plasma compartment.

Minimally invasive talc insufflation: a new technique with no need for thoracoscopy.

Talc insufflation is usually performed by thoracic surgeons in the operating room through video-assisted thoracoscopic surgery (VATS) or by pulmonologists in a specially equipped suite (medical thoracoscopy). These techniques can cause postoperative pain, require placement of port sites through small incisions, and increase waiting time and cost for patients who have no need for visual inspection of the pleura, biopsy, or apical bleb resection. Poudrage (French for powdering) with asbestos-free talcum powder (talc) is a proven technique with wide acceptance for treatment of pneumothorax. Use of a small, 4 g, canister of talc under pressure is a commonly used method to aerosolize and apply it using the supplied Teflon catheters. This report describes a patient who was too ill for almost any formal procedure in whom we performed talc poudrage by an even less invasive technique, using controlled permissive pneumothorax in the radiology suite by using a small needle, guide wire, and dilator with no thoracoscopy ports. Given the increased expense, frequent waiting time delay, and diminished access to care, we believe this technique deserves consideration in patients who are poor surgical candidates and perhaps in the young patient with no computed tomography evidence that might suggest the need for apical bleb resection, biopsy, or additional investigation.