垂体巨腺瘤MRI表现与激素水平的关系

分析６２例经临床，实验室检查及病理证实的垂体巨腺瘤的ＭＲＩ表现及与激素水平的关系。     

多巴胺激动药对大鼠垂体组织表达Pit-1作用的研究

 目的 研究多巴胺激动药对大鼠垂体组织表达Pit-1的作用.方法 成年雄性Wistar大鼠,随机分为3组,催乳素瘤(PRL)组、对照组和诺果宁组,各组按照实验程序操作.8周后处死动物,测定大鼠血清PRL水平;用免疫组化方法显示垂体组织PRL蛋白的表达和分布;用RT-PCR方法检测Pit-1 mRNA在两组垂体组织中的表达,以β-actin 作为内参照,借助于计算机凝胶成像系统分析表达量.结果 诺果宁组大鼠血清PRL水平和垂体重量均明显低于PRL瘤组(P＜0.01) , Pit-1 mRNA水平在诺果宁组较PRL瘤组明显降低(P＜0.01).结论 降低Pit-1的表达水平可能是诺果宁抗PRL瘤的重要机制之一.     

垂体腺瘤MRI与病理对照研究

目的分析垂体腺瘤的MRI表现与手术、病理关系.材料与方法对242例垂体腺瘤的MRI特征性表现进行分析,并与手术病理对照.结果大腺瘤(高度＞10 mm)161例,MRI平扫T1WI等信号101例,略低信号21例,混合信号39例,T2WI等信号112例,高信号11例,混合信号38例,增强后肿瘤实质部分均有强化,出血、囊变、坏死和钙化区无强化,微腺瘤(高度＜10mm)81例,MRI平扫表现为T1WI略低信号53例,等信号28例,T2WI等信号42例,高信号39例,注射Gd-DTPA后立即成像,77例呈相对低信号,4例呈等信号.手术和病理发现,T1WI等或略低信号区为肿瘤实质,T1WI低信号、T2WI高信号区为坏死或囊变区,T1WI、T2WI均呈高信号区为出血,手术和病理发现钙化6例,术前MRI未发现.结论MRI能清晰显示垂体瘤的大小、形态、轮廓和与周围结构的关系,可为制定手术方案提供重要依据.     

垂体腺瘤细胞VEGF表达与IL-1α和IL-6分泌的关系

目的：探讨HP75垂体腺瘤细胞株VEGF表达与细胞因子分泌的关系。方法：HP75细胞常规培养，采用ELISA方法分别检测VEGF、IL-1α和IL-6的水平。结果：（1）HP75细胞呈时间依赖性分泌VEGF、IL-1α和IL-6；（2）较大剂量的IL-1α呈剂量依赖性的刺激VEGF表达；（3）IL-6对VEGF的分泌无显著影响；（4）IL-1α和IL-6中和抗体对VEGF分泌无显著影响。结论：VEGF的表达与IL-1α的分泌密切相关，提示细胞因子在垂体腺瘤的生长过程中发挥一定作用。     

侵袭性垂体腺瘤发生的分子病理机制

目的　垂体腺瘤是颅内常见的单克隆性肿瘤 ,其生长缓慢 ,多为良性 ,但有相当一部分肿瘤可表现出侵袭性行为。侵袭性垂体腺瘤常引起一系列严重临床症状 ,致死率很高。在侵袭性垂体腺瘤的发生、发展中 ,某些基因起重要作用 ,如GSP ,MEN 1,P5 3,ras,Rb ,nm2 3基因等。人工合成的MMP 9抑制因子、溴麦角环肽、生长抑素、抗甲基化作用的药物可用于侵袭性垂体腺瘤的治疗。     

垂体腺瘤细胞VEGF表达与细胞因子分泌的关系

目的:探讨垂体腺瘤细胞株HP75 VEGF表达与细胞因子IL-1α和IL-6分泌的关系。方法:HP75细胞常规培养,经各种因素处理后,取培养上清液,采用ELISA方法分别检测VEGF、IL-1α和IL-6的分泌水平。结果:①HP75细胞时间依赖性分泌VEGF、IL-1α和IL-6;②较大剂量的IL-1α剂量依赖性的刺激VEGF表达;③所用各种剂量的IL-6对VEGF的分泌均无显著影响;④IL-1α和IL-6中和抗体对VEGF基础分泌无显著影响。结论:VEGF的表达与IL-1α和IL-6的分泌密切相关,提示细胞因子在垂体腺瘤的生长过程中发挥重要作用。     

垂体腺瘤卒中CT诊断

本文报道了24例垂体腺瘤卒中的CT 表现,除均具有垂体腺瘤的共同CT 表现以外,瘤卒中CT 征有:(1)平扫瘤体中局限密度增高;(2)瘤腔内较高密度液平;(3)增强后瘤体增强,出血灶无改变;(4)排除瘤内钙化之密度增高;(5)不同时期瘤内密度增高灶的CT 值呈动态改变。文中讨论了影响垂体腺瘤卒中检出率的若干因素,强调了CT 表现结合病史和临床表现对CT 诊断的意义.     

垂体腺瘤发生的基因调控研究进展

垂体腺瘤通常是良性的单克隆肿瘤,占颅内肿瘤的25%。垂体腺瘤的病因学还不清楚,可能有多种因素参与其发生和发展,有多种异源的癌基因和生长激素的异常表达[1-7],但也不一定是肿瘤发生的直接因素,特别是很多这些因子都是细胞转化后诱导的[8-9],可能实际上只是附带现象而不是病因     

垂体肿瘤转化基因在人垂体腺瘤中的表达

 目的用反转录-PCR方法定量研究垂体肿瘤转化基因(Pituitary tumortransforming gene,PTTG)mRNA在不同类型的垂体腺瘤中的表达,明确:(1)在不同类型的垂体腺瘤中,PTTG mRNA的表达是否存在细胞特异性,其表达量是否有差别;(2)PTTG mRNA的表达量与肿瘤分级分期的关系,从而进一步探讨PTTG在垂体腺瘤发生发展过程中的作用.方法 20例垂体腺瘤,手术中取出,迅速冻于液氮中保存.根据血清激素水平和临床表现确定腺瘤类型.根据影像学和术中所见对肿瘤分级和分期.用异硫氢酸胍一步法提取垂体腺瘤组织总RNA,用RT-PCR方法检测PTTG mRNA在各组垂体腺瘤组织中的表达.结果 20例垂体腺瘤患者,泌乳素(Prolactin,PRL)腺瘤6例,生长激素(Growth hormone,GH)腺瘤6例,无功能瘤8例.PTTG mRNA在所有PRL瘤、GH瘤和无功能瘤中有表达.PTTG mRNA在PRL、GH和无功能瘤中的表达量无明显差别.PTTG在Ⅱ级、Ⅲ级以及Ⅳ级垂体腺瘤组织中的表达量呈逐渐升高的趋势,组间比较有明显差别(P＜0.01),PTTG在A期、B期以及C期腺瘤的表达量呈逐渐升高的趋势,组间比较有明显差别(P＜0.01).结论 PTTG mRNA在PRL瘤、GH瘤以及无功能瘤中均有表达,PTTG mRNA表达量随着垂体肿瘤浸润程度的增高而升高,PTTG在垂体肿瘤发生和发展中起重要的作用.     

X射线诱导转录因子活化与凋亡的关系

目的 通过观察较高剂量照射的鼠胸腺细胞内几种转录因子活性的变化和胸腺细胞凋亡发展时程，探讨转录因子活性的变化在辐射诱导的免疫细胞凋亡中的作用。方法 通过电泳移动变化分析及流式细胞术的方法分别检测了2Gy X射线全身照射后胸腺细胞内转录因子NF－κB、CREB和OCT－1活性以及胸腺细胞凋亡的动态变化。结果 2Gy X射线全身照射后胸腺细胞内NF－κB两种二聚体p50/p50和p50/p65的DNA结合活性的变化存在着明显的区别，主要以p50/p50活性显著升高为特征，CREB OCT－1的活性也明显增强，活性高峰均出现了照射后4－12h，而它们的活性高峰又恰与2Gy照射诱导的胸腺细胞凋亡的高峰相吻合。结论 较高剂量电离辐射主要诱导NF－κB同源二聚体的DNA结合活性增强；3种转录因子NF－κB p50/50、CREB以及OCT－1可能在2Gy照射诱导的胸腺细胞内具有协同促进细胞凋亡的作用。     

尿激酶型纤溶酶原激活物在侵袭性垂体腺瘤中的表达及意义

 目的 探讨尿激酶型纤溶酶原激活物(uPA)在侵袭性垂体腺瘤和非侵袭性垂体腺瘤中的表达及其临床意义.方法 应用免疫组化法检测26例侵袭性垂体腺瘤和20例非侵袭性垂体腺瘤中uPA的表达,并结合临床资料分析.结果 uPA在侵袭性垂体腺瘤的表达明显高于在非侵袭性垂体腺瘤中的表达,uPA的表达水平与垂体腺瘤的侵袭性呈正相关.结论 uPA与垂体腺瘤侵袭性生长及复发相关,是影响预后的重要因素之一.     

Imaging of giant pituitary adenomas

We present five proven giant pituitary adenomas studied by CT and MRI, and review the clinical and imaging findings. Our aim was to examine the radiologic appearances and to search for criteria useful in distinguishing these tumors from other sellar and suprasellar tumours, mainly craniopharyngioma. The main differences from small adenomas were high prevalence of macrocysts, a more invasive behaviour and a clinical picture dominated by mass effect rather than endocrine disturbance. Factors supporting the diagnosis of pituitary adenoma in a giant intra- and suprasellar mass include: infrasellar extension, absence of calcification and presence of low-signal cysts on T1-weighted images. Received: 13 October 1997 Accepted: 25 February 1998     

CT scan of pituitary adenomas

Summary CT scan is an extremely useful, almost harmless means of diagnosing pituitary adenomas. Growth hormone (GH)-secreting adenomas tend to have higher absorption coefficient on plain CT than the nonfunctioning and prolactin (PRL)-secreting adenomas. The absorption coefficient on contrastenhanced CT does not identify the specific type of adenoma. Ring-like enhancement was observed in five nonfunctioning and four PRL-secreting adenomas with suprasellar extension, while cystic components were observed in four nonfunctioning and four PRL-secreting adenomas. In three of ten cases of PRL-secreting microadenomas, the site corresponding to the adenoma was not enhanced, whereas the normal pituitary was. A correlation exists between the size of PRL-secreting adenoma and the serum PRL level, but not between the size of GH-secreting adenomas and the serum GH level.     

Correlation between FDG-PET findings and GLUT1 expression in salivary gland pleomorphic adenomas

Objective  One reason for the difficulty in accurate preoperative pathological diagnosis of major salivary gland tumors with fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) is the tendency of pleomorphic adenomas to have a high, standardized uptake value (SUV). The expression of glucose transporter 1 (GLUT1) and the quantity of GLUT1 messenger RNA (mRNA) were analyzed in specimens of pleomorphic adenoma to identify whether GLUT1 is responsible for the increased glucose uptake in FDG-PET examinations of these tumors. Methods  Eighty salivary gland tumors resected at Yokohama City University Hospital were retrospectively investigated. FDG-PET was performed prior to surgery. PET images were evaluated by two experienced radiologists. GLUT1 was immunohistochemically stained, and GLUT1 mRNA density was quantified using real-time polymerase chain reaction in 10 of 40 pleomorphic adenomas. Results  The pleomorphic adenomas stained positively for GLUT1, and there was significant correlation between the GLUT1 index and the SUV in FDG-PET. Conclusions  GLUT1 is expressed in salivary gland pleomorphic adenomas. Furthermore, the GLUT1 index shows significant correlation with the SUV of FDGPET. This result suggests that GLUT1 plays an important role in increasing FDG uptake in salivary gland pleomorphic adenomas.     

Magnetic resonance imaging of pituitary adenomas

Today, MR is the only method needed for the morphological investigation of endocrine-active pituitary adenomas. In acromegaly and Cushings syndrome, the therapeutic attitude is directly dictated by MR data. We present the MR aspect of pituitary adenomas according to size, sex, age, endocrine activity and a few particular conditions such as hemorrhagic pituitary adenomas, pituitary adenomas during pregnancy, cavernous sinus invasion and postsurgical changes. When an intrasellar mass extending out of the sella turcica is detected, the goal of the MR examination is to indicate precisely the origin of the tumor, its extension in relation to the various surrounding structures, its structure and its enhancement in order to help in the differential diagnosis. Demonstration of very small pituitary adenomas remains a challenge. When SE T1- and Turbo SE T2-weighted sequences are non-diagnostic, enhanced imaging becomes mandatory; half-dose gadolinium injection, delayed sequence, dynamic imaging can be of some help.