Kiyohito Shinno

Oxidized LDL in Carotid Plaques and Plasma Associates With Plaque Instability

Objective—Oxidation of LDL plays a significant pathogenic role in atherosclerosis. In this study, we attempted to clarify the correlation between the morphology of human atherosclerotic plaques and the oxidized LDL (OxLDL) levels in plasma and carotid plaques. Methods and Results—OxLDL levels (ng/&mgr;g apolipoprotein B) in plasma and carotid plaques from 44 patients undergoing carotid endarterectomy and OxLDL levels in 17 control plasma and 9 normal intima samples were determined by a sandwich ELISA by using specific antibodies against OxLDL (DLH3) and apolipoprotein B. The plaques were immunohistochemically classified as macrophage (M&phgr;)-rich and M&phgr;-poor. In paired samples from individual patients, plaque OxLDL was nearly 70 times higher than plasma OxLDL (mean±SEM, 11.9±1.7 vs 0.18±0.01 ng/&mgr;g apoB, P <0.0001). The OxLDL level was significantly higher in M&phgr;-rich- than M&phgr;-poor plaques (19.6±2.8 vs 5.50±0.77ng/&mgr;g apoB, P <0.0001) and corresponded with DLH3 antigen positivity of the plaques. In patients with M&phgr;-rich plaques, plasma OxLDL was significantly higher than in the controls (0.20±0.02 vs 0.13±0.01ng/&mgr;g apoB, P =0.02). Conclusions—Our results suggest that LDL undergoes further oxidation in plaques, and that high plasma and plaque levels of OxLDL are correlated with the vulnerability to rupture of atherosclerotic lesions.

Clinicopathological significance of lipid peroxidation in carotid plaques

Several reports have suggested an association between lipid peroxidation and human carotid atherosclerosis, but few reports have demonstrated a link between lipid peroxidation and carotid plaques in humans. In this study, we investigated the relationship between clinical features, histopathological characteristics and lipid peroxidation in patients undergoing carotid endarterectomy (CEA). Forty-one carotid plaques were obtained. A portion of the most severe lesions was subjected to histopathologic examination, and the remainder of the plaques examined for lipid peroxidation. Thiobarbituric acid-reactive substances (TBARS) values were determined as a marker for lipid peroxidation. The lipid-rich core (LC) and macrophage infiltration (Mphi) component as a percentage of total plaque area were measured morphometrically. Based on the results, all plaques were classified into four groups. Group I (GI): LC <10%; Group IIa (GIIa): LC 10-30%, Mphi <5%; Group IIb (GIIb): LC 10-30%, Mphi < or = 5%, and Group III (GIII): LC < or =30%. The plaque TBARS values of GIII were significantly higher than those of GI, GIIa, and GIIb. The TBARS values of GIIb were one-and-a-half times higher than those of GIIa. Our results show that lipid peroxidation in carotid plaques is significantly associated with carotid atherosclerosis, especially plaque instability. These findings provide direct evidence of an association between lipid peroxidation and human atherosclerosis.

Multiple cavernous hemangiomas of the orbits

Intraocular tumors were detected in both orbits simultaneously by computed tomography scanning in a 45-year-old woman complaining of proptosis of the right eye, decreased visual acuity, and diplopia. The tumor in the right orbit was resected by the subfrontal extradural approach, and that in the left orbit by the Krönlein-Berke method. The right tumor was found on the side of the external ear of the muscle cone and the left tumor was located inferiorly on the side of the external ear of the muscle cone. Both tumors were cavernous hemangiomas with identical macroscopic and histologic features.

Carotid endarterectomy with external shunt: a new device and indication for use: technical note.

OBJECTIVE We designed a new external shunt system and evaluated its indications and efficacy in patients undergoing carotid endarterectomy (CEA). METHODS In 8 of 332 CEA procedures, external shunts were placed between the common carotid artery and the internal carotid artery (ICA). This procedure was implemented for one of two indications: 1) a change in electroencephalographic and/or somatosensory evoked potential readings immediately after ICA occlusion, or 2) elongation of the ICA made safe insertion of an internal shunt impossible. In addition, a shunt was placed between the common carotid artery and the external carotid artery to establish collateral circulation from the external carotid artery to the intracranial circulation, which is essential during ICA occlusion. RESULTS All external shunts were functional, and electroencephalography and somatosensory evoked potentials demonstrated no significant abnormalities during the CEAs. All patients awoke from surgery without manifestation of new neurological deficits. CONCLUSION Our new external shunt device proved safe and efficacious in cases that did not permit the placement of an internal shunt.