Local blood flow changes in malignant brain tumours under induced hypertension

Summary Changes in tumour blood flow under an induced hypertensive state were examined in malignant brain tumours to know if the precondition for the effectiveness of induced hypertensive chemotherapy — relative increase in tumour blood flow — are fulfilled. Tumour blood flow was measured under both a resting and an induced hypertensive state in 12 patients with various malignant brain tumours (6 gliomas, 6 metastatic brain tumours) using xenon-enhanced computed tomography. The blood pressure was elevated 40% above the systemic blood pressure of the resting state by the infusion of angiotensin II. Tumour blood flow increased 30% on average above the normal brain tissue blood flow after the induction of an induced hypertensive state (p < 0.05). The tumour blood flow increased in 11 cases of malignant tumours, but decreased in one case with massive brain oedema after induced hypertension. The increase in blood flow was higher in hypervascular tumours and less in hypovascular tumours. Therefore, induced hypertensive chemotherapy probably will be more effective in hypervascular malignant brain tumours with small mass effects.     

血卟啉衍生物(HpD)—激光对缺血小鼠肾脏的影响—光镜、组化和电镜观察

经尾静脉给雄性昆明小鼠注入HpD(10mg/kg体重),48小时后阻断肾动脉,造成缺血、缺氧的肾脏模型。然后用250—300J/cm~2剂量的630nm波长激光照射小鼠肾脏。最早出现的形态学改变是间质水肿和毛细血管破坏。近端小管上皮细胞在光照后6小时出现形态学改变,其它结构均在光照后24小时发生坏死。超微结构主要是线粒体、内质网和细胞核的破坏。肾酶的损伤程度为Cytox>AKP>ACP>SDH。实验结果表明,断血肾脏对血卟啉光动力学作用敏感性降低,但血管损伤加重。因此,血管损伤不是造成实质细胞损伤的始动因素,氧在血卟啉光动力学作用中是必需的。     

Wnt-1诱导分泌蛋白1在直肠癌中的表达及其临床意义

目的定量检测Wnt-1诱导分泌蛋白1（Wnt-1 induced secreted protein-1，WISP-1）基因在人直肠癌及远端正常直肠组织中的表达，为进一步研究该基因功能提供线索。方法提取人直肠癌及癌旁正常直肠组织总RNA，采用实时RT—PCR分析WISP-1的表达，再对PCR结果进行分析。结果WISP-1 mRNA在直肠癌组织中的表达水平显著高于癌旁正常直肠组织，差异有统计学意义（P〈0．05）。WISP-1的表达与肿瘤的分化程度、Dukes分期及淋巴结转移等因素有相关性。结论WISP-1基因的异常表达可能与直肠癌的发生、发展有关，有望成为直肠癌诊断预后的标志物和治疗的新靶点。     

碱性成纤维细胞生长因子对受照后大鼠血脑屏障的影响

目的评价定量检测放射性血脑屏障（BBB）破坏的不同方法，探讨碱性成纤维细胞生长因子（bFGF）对放射性BBB破坏的保护作用。方法60只急性放射性脑损伤模型大鼠（直线加速器6MeV电子束单次照射25Gy）分为单纯照射组和照射前尾静脉注射bFGF组（250ng／kg），并设未照射对照组；分别于照射后2、7和30d采用脑干-湿重法检测脑含水量，并用单次静脉注射3mg／kg伊文氏蓝（EB）后脑组织的EB含量法评估BBB破坏情况。结果照射后脑组织含水量和EB含量均较对照组明显增高，注射bFGF组脑组织含水量和EB含量均低于单纯照射组（P〈0．05）。受照后不同日期的脑组织EB含量差异有统计学意义（P〈0．05），而脑含水量差异没有统计学意义。结论注射EB后检测脑组织，浓度法较干湿重法测脑含水量能更好地反映BBB的破坏情况；bFGF对受照后BBB破坏有保护作用。     

Fas、Bcl-2在γ射线体外诱发的白血病小鼠骨髓细胞中的表达

目的 :观察 Fas、Bcl- 2在 γ射线体外诱发的急性淋巴细胞白血病小鼠骨髓细胞中表达情况 ,以探讨辐射致癌的机制。方法 :采用 4次 1.75 Gyγ射线全身照射 BAL B/ c小鼠诱发白血病模型 ,通过流式细胞仪对照射后白血病组、未癌变组及对照组小鼠骨髓细胞中 Fas、Bcl- 2的表达进行检测 ;应用抗 Fas抗体诱导细胞凋亡 ,进一步观察 Fas、Bcl- 2的表达对骨髓细胞凋亡的影响。 结果 :白血病小鼠骨髓细胞 Fas表达较未癌变组及对照组明显下降 (P<0 .0 1) ,而 Bcl- 2的表达明显增强 (P<0 .0 1) ;白血病小鼠骨髓细胞明显耐受抗 Fas抗体诱导的细胞凋亡。 结论 :Fas低表达、Bcl- 2高表达导致了细胞凋亡受到抑制 ,这可能是辐射引起小鼠急性淋巴细胞白血病的机制之一。     

~(60)Coγ射线照射诱发小鼠恶性肿瘤

目的：建立γ射线诱发小鼠恶性肿瘤动物模型。方法：BALB／c小鼠经^60Coγ射线全身照射，每次吸收剂量1．75Gy，吸收剂量率0．88Gy／min，每周1次，共4次。照后每隔1～2个月处死一批小鼠，分别取胸腺、肺脏、肝脏、脾脏、肾脏、胃、生殖腺、肠系膜、盲肠、大脑等组织器官，甲醛溶液固定后进行病理学检查及裸鼠致瘤实验。结果：照后15个月BALB／c小鼠出现的肿瘤类型以白血病为主，并发现汗腺瘤及恶性卵黄囊瘤；白血病经病理学证实为淋巴细胞型白血病；白血病及汗腺瘤的裸鼠致瘤实验已稳定连续传至第12代。结论：成功建立^60Coγ射线体外诱发的小鼠恶性肿瘤动物模型。     

化疗药物性静脉炎及渗漏损伤的动物实验模型研究概况

化疗药物性静脉炎及渗漏损伤的动物实验模型是研究体内化疗药物性静脉炎及渗漏损伤的发病机制和评价各种治疗方法的重要条件。化疗药物性静脉炎及渗漏损伤的实验研究进展缓慢,其主要原因是缺乏理想的动物模型。依文献报道,化疗药物性静脉炎模型主要以大白兔耳缘静脉注射长春瑞滨等化疗药物为多见,化疗药物渗漏损伤模型主要以大鼠及大白兔背部皮下注射盐酸阿霉素等化疗药物为多见。文章就近年来常用的一些化疗药物性静脉炎及渗漏损伤的动物模型综述如下。     

母体钙代谢与补钙对妊娠的影响

妊娠期缺钙严重影响母婴的安全健康 ,其原因是由于妊娠期母体钙代谢发生变化 ,使母体血清游离钙离子浓度降低 ,血清铅浓度增高。有关研究表明 ,母体缺钙导致血铅竞争性过高 ,使胎儿身长、体重均小于胎龄儿 ,胎儿宫内发育迟缓的发生率增高 ,甚至发生早产、死胎等。同时发现血清钙离子可能对内源性一氧化氮合成释放起调节作用 ,而内皮素是最强的缩血管物质之一 ,母体补钙可调节一氧化氮与内皮素的平衡 ,从而降低妊高征的发生率。因此孕期补充钙剂是非常重要的。     

脑干听觉诱发电位诊断听神经瘤的假阳性分析

综合分析ＢＡＥＰ各项指标，应用ＣＰＡ病变的ＢＡＥＰ４型诊断标准，从６００例可疑听神经瘤患者中，诊断出ＣＰＡ肿瘤５４例，同时发现４例假阳性。本文的假阳性率为７％（４／５８），较多数文献报道为低。在诊断听神经瘤中，ＢＡＥＰ的峰间期比波的绝对潜伏期准确，只有Ⅰ～Ⅲ峰间期增大所导致的Ⅰ～Ⅴ峰间期增大，才有诊断价值，ＢＡＥＰ只有定位作用，无定性价值，故ＢＡＥＰ诊断听神经瘤必须结合临床表现才有意义。在临床上即使已有明确的长束征时，但ＢＡＥＰ无健侧Ⅳ～Ⅴ波的改变，仍可排除肿瘤的诊断。在ＢＡＥＰ的Ⅳ型中，当健侧Ⅳ～Ⅴ波正常时，应参考复合检查，若其阴性则可排除肿瘤的诊断。     

Metalloproteinase activity is present in rat urine and derived from the renal cortex

Summary: Matrix metalloproteinases (MP) are important candidates for the degradation of extracellular matrix, but the role of MP in the diseased kidney remains poorly understood. to examine the significance of urinary MP, we first investigated the characteristics of MP in normal rat urine and renal cortex, and then evaluated the urinary MP activity in anti-thymocyte induced glomerulonephritis (Thy.1 GN). Metalloproteinase activity was measured as the EDTA-inhibitable degradation of [³H] gelatin. the enzyme was purified from urine and the renal cortex homogenate in normal Wistar rats by using several chromatographic and gel filtration methods. Both materials contained the identical molecular weight (Mr 126 kDa by gel permeation method) of gelatin-degrading enzymes, the activity of which was inhibited by metal chelating agents and reactivated by ZnC1₂ but not by other proteinase inhibitors. Thy.1 GN was induced by intravenous injection of rabbit anti-thymocyte serum into rats, and daily urine was collected at sequential time points. Urinary MP activity was markedly reduced soon after the serum injection, and returned to the control level in 9 weeks. Conversely, urinary MP-inhibitor activity (Mr 30 kDa), determined as inhibiting activity against MP derived from renal cortex, showed serial changes strikingly reflected as urinary MP activity. These findings suggested that rat urine contained the MP which seemed to be derived from the renal cortex, and the urinary MP activity was decreased in Thy.1 GN model, probably due to the presence of MP-inhibitor. As urinary MP is likely to reflect intra-renal MP, the evaluation of urinary MP may be useful to search metabolic alteration of extracellular matrix in the diseased kidney.