• 作者： 李英雄; 陳琇青; 賴淑美
• 作者服務機構： 長庚紀念醫院心臟血管內科
• 中文摘要： 動脈粥瘤病變之發展牽涉到兩個重要之過程，即脂質之沈澱及纖維-細胞之增生。因脂質堆積而形成了動脈粥瘤之脂質核心。雖然以往對於人類動脈粥瘤脂質核心之超微結構有過研究，但在分子甚至原子層次之探討至今尚未描述。最近，高解析度電子顯微鏡之問世，已漸漸應用於觀察生物醫學標本之原子層次結構。因此，本篇研究之目的在利用高解析度電子顯微鏡探討人類動脈粥瘤硬化脂質核心之原子結構組織，及以與電子顯微鏡連線的X-光微分析儀探測粥瘤基質內各種元素之存在與分佈。希望藉此能發現結構上之新知，有助於瞭解動脈粥瘤硬化之致病機轉。 動脈粥瘤之標本取之於屍體解剖時人類主動脈壁。經清洗、風乾、研磨成粉末而置於銅網上供電子顯微鏡觀察。所使用之電子顯微鏡是日立H - 9000高解析度電子顯微鏡，在300KV之加速電壓下觀察標本之結構，尤其著重於結晶顆粒原子結構影像之探索。 在高解析度電子顯微鏡之觀察下，在動脈粥瘤脂質核心之無定形的基質中散佈著各種形狀，大小不一的微晶粒及晶粒。即使是晶粒，其結晶程度之完整性還是各有差異。在無定形之基質是由顆粒纖維狀之次結構交織而成。在高度完整之結晶可觀察到非常規則之晶格線。這些晶格線是由原子尺寸之點，直徑約為0.13.~0.15nm所排列而成。至於交界面之組織結構，在無定形基質相與結晶相之接觸處可觀察到顆粒纖維次結構緊緊地連接著晶格線。而在晶格相之接觸面可觀察到晶格線之配合非常一致及交界面之原子排列影像。至於動脈粥瘤基質內元素之存在，於X-光微分析儀之測試下，鈣元素是唯一到處可見而分佈廣泛者。因此我可以推測如下：(1) 無定形基質中的顆粒纖維所形成之網狀結構提供了有機的基質晶化之起點而有結構與調節之功能 (2)此種礦物元素之沈積在由無定形基質相轉化成結晶相的過程中扮演重要的角色。由這些結果顯示本篇研究已成功地觀察到人類動脈粥瘤硬化脂質核心晶粒之原子結構影像。提供有關脂質核心形成與進展之新知識，藉以瞭解其原子層次之病理機轉。
• 英文摘要： Atomic structural images in the calcified matrix of human atherosclerotic plaques were characterizedby high-resolution electron microscopy (HREM). The mineral elements distributed in the calcified matrixwere analysed by energy dispersive X-ray microanalysis, Careful HREM observations revealed that a largenumber of microcrystallites and crystal particles with a broad spectrum of crystal size and perfection wereembedded in the amorphous matrix of the calcified plaques. The amorphous phase in the calcified matrixwas made up of a dense network of granulo-fibrillar substructures. The lattice-fringes with regular ar-rangement of atom columns along the lattice arrays were clearly demonstrated in the crystalline particlesof the calcified plaques. A number of characteristic granulo-fibrillar substructures in the amorphous phasecould be seen to be tightly connected to the lattice-fringes in the crystalline phase along the interfaces be-tween the amorphous and crystalline phases. The crystal lattices at the boundary between two crystals werevery well matched with the periodicity of visible atoms continuous through the two crystals. The mineralelements such as calcium and phosphorus were detected to be diffusely distributed in the calcified matrixof the atherosclerotic plaques. Based on these findings, it is concluded that: (1) an interlacing networkof granulo-fibrillar substructures in the amorphous matrix may play a structural and/or regulatory role forthe organic matrix by providing sites for nucleation; and (2) the deposition of the mineral elements may beeffective for the transformation of the amorphous nucleation phase to well-crystallized nucleation phase.
• 中文關鍵字： atomic structure; atherosclerotic plaques; high-resolution electron microscopy; X-ray microanalysis.
• 英文關鍵字： --