臺灣博碩士論文加值系統

前言
子癲前症(preeclampsia)是一種在妊娠20 週以後發生高血壓，蛋白尿及水腫的疾病，發生率約7%到10%，它是造成胎兒罹病及流產死亡最常見原因，及懷孕母親死亡的第二常見因素，它的確實病理機轉目前仍完全明白，而胎盤就是一個重要因素，一般相信胎盤中的絨毛(villus)異常與此疾病有密切關連，隨著懷孕週數增加，絨毛會增殖(proliferation)、移行(migration)及深入(invasion)子宮，形成胎兒與母親的養份交流站，因此絨毛上的滋養層細胞(trophoblastic cells)絕對是一個重要關鍵。胎盤中的滋養層細胞凋亡(apoptosis)與增殖與子癲前症是否有關，目前研究的資料仍不多，本篇研究主要目的在比較子癲前症與正常懷孕胎盤，其滋養層細胞凋亡及增殖的表現是否有所不同，以期更了解及解釋子癲前症的病理機轉。

研究材料與方法
胎盤組織是從7 位正常足月妊娠與7 位子癲前症取出，她們皆是接受剖腹生產，且在產程陣痛之前就生產，細胞凋亡的研究是利用TUNEL方法，在評估細胞增殖的方法是利用免疫組織化學染色法，測出Ki-67、 Bcl-2, BMP family (bone morphogenetic protein)、CD34、VEGF( vascular endothelial growth factor) & VEGF receptor-I在滋養層細胞的免疫組織化學表現。結果評估方式則是利用下列兩項：一為positive index rate(%) 代表染色有陽性反應者占所有細胞的比例。二為semiquantitative immunohistochemical Remmele score(IRS)。皆利用光學顯微鏡來做為計數工具，獲得平均值 ± 標準差。比較子癲前症與正常者胎盤滋養層細胞在凋亡與增殖表現的不同。

研究結果
在子癲前症胎盤滋養層細胞發生細胞凋亡的平均值是0.37 ± 0.04 % ，高於正常胎盤是0.18 ± 0.05%。Ki-67的表現在子癲前症滋養層細胞發生的平均值是4.60 ± 0.20%，高於正常胎盤3.96 ± 0.39%；細胞凋亡與Ki-67的表現在子癲前症病人較正常者來的顯著明顯。而Bcl-2 的 IRS 在子癲前症與正常者分別是 3.70 ± 0.86 和 4.03 ± 1.25，子癲前症雖較正常者低，但統計學上無明顯意義。VEGF在子癲前症胎盤裡陽性比例平均值7.02 ± 1.15，而正常者為6.68 ± 0.73，雖然子癲前症滋養層細胞質內VEGF 蛋白表現較正常者較高，但統計學上也無明顯差異，其他標誌例如 CD34、BMP protein family、VEGF receptor則兩者相同表現。



結論
子癲前症胎盤的滋養層細胞Apoptosis 及Ki-67的表現皆比正常者明顯增加，其原因可能和anti-apoptotic factor(Bcl-2 protein) 表現減少，或是因為胎盤絨毛血管內膜細胞功能異常造成組織缺氧，另一方面up-regulation proliferation 的表現(例如VEGF、Ki-67)；可見這些因子的表現在子癲前症的病理機轉上扮演著一定角色。

Abstract


Background
Preeclampsia is characterized by hypertension, edema, and proteinuria and affects 7-10% of all pregnancies. It is a major cause of maternal and fetal morbidity and mortality, but its etiology remains unknown. The human placenta is a tumorlike organ in which proliferation, migration, and invasion of extravillous trophoblastic cells take place. Trophoblastic cells migrate and invade the uterus and its vasculature to provide a vital link between the mother and the developing fetus. Trophoblastic cell play an important role in maintance of placental function. Little information, however, is available on the roles of apoptosis and proliferation in the trophoblast of placenta in relation to the pathophysiology of preeclampsia.

Objectives
The aim of the study was to compare the difference between preeclampsia and normal term pregnancy placenta in the expression of some proliferation and apoptotic/anti-apoptotic markers in the human placenta.


Materials and Methods
Placental samples were obtained form 7 normal uncomplicated term pregnancy and 7 preeclampsia patients. Placenta samples were collected during cesarean section. None of the patients were in labor. After extraction of the newborn, placental insertion was verified and the placenta was rapidly delivered. Placenta villi were corrected in the center part of the placenta avoiding infracted areas. Apoptosis was assessed by the terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling(TUNEL) method. Expression of Ki-67, Bcl-2, BMP family (bone morphogenetic protein)、CD 34、VEGF( vascular endothelial growth factor) & VEGF receptor-II were assessed using immunohistochemistry. Light microscopy was used to quantify its incidence. The positive index rate (%) was defined as (positive stain cells/ total nuclei) X 100 and expressed as mean ± SD. The Bcl-2 and VEGF expression were assessd by semiquantitative Immunohistochemical Remmele Score(IRS). For each placenta, 5 randomized fields are examined by light microscopy at a magnification of x 200(x 20 objective lens and x 10 eyepiece). Statistical significance was determined by using analysis of variance to compare the rates between normal and preeclampsia placentas. Statistical significance was considered to be present at P < 0.05. ( Mann Whitney U test).

Result
The TUNEL-positive cells of the placenta were trophoblast with cluster of nuclei and the TUNEL-positive index of these cells was 0.37% ± 0.04% and normal placenta was 0.18% ± 0.05%. The Ki-67-positive index cells was 4.6% ± 0.2% and normal placenta was 3.9% ± 0.3%. The incidence of apoptosis and Ki-67 expression were significantly higher in preeclampsia placentas compared with normal. In contrast the Bcl-2 expression was lower in preeclampsia than normal, although no significant difference. And VEGF protein was higher in preeclampsia than normal, although still no significanct difference. The other expression markers ( ex. CD34 , BMP protein family, VEGF receptor) were no statistical significance difference between preeclampsia and normal placentas.

Conclusion
These results suggest that trophoblast proliferation and apoptosis may paly a role in the pathophysiologic mechanisms of preeclampsia.

目錄
頁碼
中文摘要 I
英文摘要 IV
目錄 VIII
附表目錄 X
附圖目錄 XI
第一章 論文正文前言 1
第一節 研究背景 2
子癲前症 2
胎盤的凋亡與增殖 2
TUNEL 5
Ki-67 表現 5
骨誘導蛋白 6
CD34 7
血管內皮生長因子 7
第二節 研究目的 8
第二章 研究方法 8
第一節 研究材料 9
第二節 研究設計 11
第三節 統計方法 14
第三章 研究結果 15
第四章 討論 18
第一節 結果討論 18
第二節 研究限制 20
第五章 結論與建議 21
第一節 結論 21
第二節 建議 21



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附錄 41

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