Moczar M, Lecerf L, Mazzucotelli J P, Loisance D
Centre de Recherches Chirurgicales Henri Mondor, CNRS URA 1431, Creteil, France.
J Heart Valve Dis. 1996 Nov;5 Suppl 3:S276-83.
Twenty-two bovine pericardial Mitroflow prostheses were explanted after 73-114 months from either the aortic or mitral position because of clinical failure. All the samples exhibited cuspal tears and foldings. Eleven prostheses were calcified. The aim was to study biological factors involved in the structural deterioration.
Histologic and biochemical assays were carried out on the deteriorated, non-calcified and on the calcified leaflets. Labelled antibodies and avidinbiotinyilated peroxydase complex were used to detect plasma proteins and cells in the cusps.
Fibrin covered the cuspal surface and accumulated in the deep disrupted layers (19/22). Scattered fibronectin filaments were seen across the transversal sections (20/22). IgG, complement fractions C1q, C3, C4 (20/22), macrophages (sixteen) and cells containing granulocyte elastase were revealed in the altered matrix. These plasma proteins and cells were detected in the disintegrated matrix of non-calcified and of calcified leaflets. IgA was present in amorphous cuspal thickenings with lipid infiltration (12/22). Western blot analysis of the PBS-2% SDS extracts from the leaflets indicated the breakdown of fibrinogen/fibrin, fibronectin and of complement proteins C3, C4 and C5.
The results suggest the activation of the complement by the non-hemocompatible, chemically processed bovine pericardium. The bioactive peptides generated in this process can stimulate monocyte migration, phagocytosis and exocytosis of proteases able to degrade the glutaraldehyde cross-linked macromolecular matrix. These biological factors can contribute, together with the mechanical stress, to the structural deterioration of the bioprosthesis.
22个牛心包Mitroflow人工心脏瓣膜因临床功能衰竭，在植入主动脉或二尖瓣位置73 - 114个月后被取出。所有样本均出现瓣叶撕裂和折叠。11个瓣膜发生钙化。目的是研究参与结构退化的生物学因素。
对退化的、未钙化的和钙化的瓣叶进行组织学和生化分析。使用标记抗体和抗生物素蛋白 - 生物素化过氧化物酶复合物检测瓣叶中的血浆蛋白和细胞。
纤维蛋白覆盖瓣叶表面并积聚在深层破坏层（19/22）。在横切面上可见散在的纤连蛋白丝（20/22）。在改变的基质中发现了IgG、补体成分C1q、C3、C4（20/22）、巨噬细胞（16个）以及含有粒细胞弹性蛋白酶的细胞。在未钙化和钙化瓣叶的崩解基质中均检测到这些血浆蛋白和细胞。IgA存在于伴有脂质浸润的无定形瓣叶增厚处（12/22）。对瓣叶的PBS - 2% SDS提取物进行的蛋白质印迹分析表明纤维蛋白原/纤维蛋白、纤连蛋白以及补体蛋白C3、C4和C5发生了降解。
结果表明，经化学处理的非血液相容性牛心包可激活补体。在此过程中产生的生物活性肽可刺激单核细胞迁移、吞噬作用以及能够降解戊二醛交联大分子基质的蛋白酶的胞吐作用。这些生物学因素与机械应力共同作用，可导致生物假体的结构退化。
