In vitro model of atherosclerosis using coculture of arterial wall cells and macrophage

In order to determine the precise mechanism of the interactions between different types of cells, which are common phenomena in tissues and organs, the importance of coculture techniques are becoming increasingly important. In the area of cardiology, artificial arteries have been developed, based on the understanding of physiological communication of the arterial smooth muscle cells (SMC), endothelial cells (EC), and the extracellular matrix (ECM). In the study of atherosclerosis, the modification of low-density lipoprotein (LDL), which result in the recruitment and accumulation of white blood cells, especially, monocytes/macrophages, and foam cell formation, are hypothesized. Although there are well known animal models, an in vitro model of atherogenesis with a precisely known atherogenesis mechanism has not yet been developed. In this paper, an arterial wall reconstruction model using rabbit primary cultivated aortic SMCs and ECs, was shown. In addition, human peripheral monocytes were used and the transmigration of monocytes was observed by scanning electron and laser confocal microscopy. Monocyte differentiation into macrophages was shown by immunohistochemistry and comprehensive gene expression analysis. With the modified form of LDL, the macrophages were observed to accumulate lipids with a foamy appearance and differentiate into the foam cells in the ECM between the ECs and SMCs in the area of our coculture model.

A Case of Thromboexclusion with Axillo-Bifemoral Bypass Grafting for Unresectable Abdominal Aortic Aneurysm / 日本心臓血管外科学会雑誌

We performed the thromboexclusion procedure with reconstruction by an axillo-bifemoral bypass for unresectable abdominal aortic aneurysm combined with chronic renal faliure, and obtained satisfactory postoperative result. The patient was a 68-year-old male who suffered from a huge abdominal aortic aneurysm (AAA) and had a history of hypertension and chronic renal failure. The AAA was accompanied with a saccular portion 10cm in diameter which compressed and eroded the vertebral body. Aortic cross-clamping above the bilateral renal arteries was inevitable for resection in spite of the renal dysfunction. We decided that direct manipulation of the aneurysm was impossible despite it being on the verge of rupture, considering the high operative mortality. We employed the exclusion-bypass method to stabilize the aneurysm, that is, we constructed axillo-bifemoral bypass using a knitted Dacron T-graft 8mm in diameter and then intercepted the bilateral common iliac arteries by suture closure. Postoperative intraaneurysmal thrombosis progressed rapidly from the distal side, then it halted just below the bilateral renal arteries on the 12th postoperative day. Renal arterial flow was maintained and renal function improved. Bleeding from the operative wound occurred suddenly on the 5th postoperative day. Although this appeared to be disseminated intravascular coagulation initially, it had resulted from augmentation of fibrinolysis due do acceleration of coagulation. The markers of fibrinolysis for example α₂ plasmin inhibitor (α₂PI) and plasmin-α₂ plasmin inhibitor complex (PIC) were useful for diagnosis, and tranexam acid and aprotinin were effective for therapy. Although the exclusion-bypass method is technically less invasive and useful for high-risk AAA, the postoperative management is not easy because of the acceleration of the coagulation-fibrinolysis system.