Optic chiasm glioma,electrolyte abnormalities,nonobstructive hydrocephalus and ascites

A 4-year-old girl with optic chiasm glioma (OCG), nonobstructive hydrocephalus and ventriculoperitoneal shunt is described, in whom marked ascites developed. The ascitic fluid was protein-rich and its amount correlated with cerebrospinal fluid (CSF) protein. The CSF protein level and the amount of ascitic fluid were influenced by chemotherapy. Very unusual hypernatremia, up to 190 mEq/l, with no associated alteration in mental status, was also found. It is suggested that altered absorption ability owing to the high protein content was the cause of both the nonobstructive hydrocephalus and the ascites. The unusual well being with very high sodium concentrations may have resulted from osmoreceptor dysfunction, presumably caused by hypothalamic involvement as well as by the high CSF protein. This combination of findings may point toward specific characteristics of OCG. In an effort to reduce the amount of the ascitic fluid, a further chemotherapeutic trial may be done, before converting the shunt to the vetriculoatrial system. Med. Pediatr. Oncol. 29:33–35, 1997. © 1997 Wiley-Liss, Inc.     

立体定向放射治疗联合替莫唑胺治疗复发性脑胶质瘤的疗效

目的：探讨立体定向放射治疗联合替莫唑胺治疗复发性脑胶质瘤的临床疗效。方法：回顾性总结36例复 发性脑胶质瘤患者的临床资料,其中24例患者予以立体定向放射治疗联合替莫唑胺治疗(SRT-TMZ组),12例患者予 以立体定向放射治疗(SRT组),比较2组的临床疗效及不良反应。结果：复发性脑胶质瘤治疗后总有效率为66.67%, 总局控率为93.94%,无晚期不良反应。其中SRT-TMZ组的总有效率为77.27%,局控率为95.45%;优于SRT组,但差异 无统计学意义(P>0.05)。33例患者0.5,1,2,3年生存率分别为90.91%,63.64%,42.42%,15.15%,其中SRT-TMZ组 0.5,1,2,3年生存率分别为95.45%,72.72%,54.54%,22.73%;SRT组0.5,1,2,3年生存率分别为81.82%,45.45%, 18.18%,0%。生存分析显示SRT-TMZ组生存时间长于SRT组(30.00个月 vs 14.00个月,P=0.010)。结论：立体定向放射 治疗联合替莫唑胺是姑息性治疗复发性脑胶质瘤的有效手段,对于提高患者近期疗效和生存率有积极作用。     

双配体修饰的阿霉素脂质体靶向于脑胶质瘤的体外研究

目的筛选和优化转铁蛋白、叶酸共同修饰的阿霉素脂质体的处方及制备工艺,以期得到具有良好的脑胶质瘤靶向治疗作用的给药系统。方法采用薄膜分散和硫酸铵梯度法制备阿霉素脂质体。将叶酸连接至二硬脂酸磷脂酰乙醇胺-聚乙二醇2000(DSPE-PEG2000-NH2)得到DSPE-PEG2000-Folic,考察不同磷脂种类、药脂比、水化介质和载药时间,对脂质体粒径、包封率和稳定性的影响,确定脂质体的处方工艺。以大鼠的脑毛细血管内皮细胞(bEnd3)和星形胶质细胞组成体外血脑屏障(blood-brain barrier,BBB),并结合大鼠胶质瘤C6细胞,构建体外模拟胶质瘤靶向治疗的复合BBB模型。考察阿霉素脂质体在bEnd3细胞中的摄取机制和透过BBB的转运速率及对C6细胞的毒性。结果确定了DSPC作为主要磷脂组分,并以120 mmol.L 1的硫酸铵作为水化介质,药脂比为1∶1 5,载药时间选择60 min,成功制备了高包封率和稳定性的双配体脂质体。其在bEnd3细胞中摄取远大于普通脂质体(P<0.05),摄取过程受网格蛋白和小窝内陷介导的细胞内吞作用,并受转铁蛋白和叶酸的影响;同时其在BBB模型中的药物透过速率、及其进一步透过BBB后对下层C6细胞的毒性,均显著高于其他脂质体组。结论转铁蛋白和叶酸共同修饰的阿霉素脂质体具有较好的体外脑胶质瘤靶向治疗作用。     

4-aminopyridine causes apoptosis and blocks an outward rectifier K+ channel in malignant astrocytoma cell lines

Among the ion channels and pumps activated by growth factor stimulation, K⁺ channels have been implicated in the growth and proliferation of several cancer cell lines. The role of these channels in central nervous system tumors, however, has not been described. This study used the malignant astrocytoma cell lines U87 and A172. 4-Aminopyridine (4-AP) inhibition of proliferation was dose dependent, and assessment using a TUNEL in situ assay revealed that apoptosis occurred in U87 cells with wild-type p53 but not in A172 cells with mutant p53 (24-hr incubation with 4 mM 4-AP). In patch clamp experiments, we identified two types of K⁺ currents in both cell lines, a charybdotoxin-sensitive Ca²⁺-activated K⁺ channel and a 4-AP-sensitive outward rectifier K⁺ current. The outward rectifier current was blocked by 4-AP in a dose-dependent manner, with half-maximal block occurring at 3.9 mM. The blocking effect of 4 mM 4-AP was noticeable at potentials as low as −65 mV and was statistically significant at −60 mV and above, suggesting that 4-AP-sensitive current is active at physiological potentials. By contrast, charybdotoxin (1 μM) and tetraethylammonium · Cl (2 mM) blocked the Ca²⁺-activated K⁺ channel in both cell lines but had no appreciable effect on cell growth. Our findings reveal that 4-AP inhibits proliferation and the outward rectifier K⁺ channel in both U87 and A172 cells. More studies are needed, however, to describe the mechanism by which K⁺ channels influence proliferation and induce apoptosis. J. Neurosci. Res. 48:122–127, 1997. © 1997 Wiley-Liss, Inc.     

重组腺相关病毒载体介导血管抑素基因治疗大鼠脑胶质瘤的实验研究

目的制备大鼠脑胶质瘤模型,注射腺相关病毒血管抑素基因重组载体(AAV-AS),观察对脑胶质瘤的治疗效果。方法皮下接种C6脑胶质瘤细胞制备大鼠胶质瘤模型,皮下注射AAV-AS,24天后取材,观察瘤重、肿瘤坏死率和血管计数,RTP-CR法检测AS转录。结果AAVAS治疗组肿瘤体积明显缩小,坏死明显,血管计数减少,RT-PCR法检测到AS转录。结论AAV-AS在大鼠体内可以表达,通过抑制血管生成而抑制肿瘤生长,促进肿瘤坏死。     

Recurrent NF1 gene mutation in a patient with oligosymptomatic neurofibromatosis type 1 (NF1)

We report a 21-year-old male with symptomatic optic glioma who does not fulfill the diagnosis of neurofibromatosis 1 (NF1) according to standard NIH criteria. Analysis of the NF1 gene revealed a recurrent mutation in exon 37 (C6792A or Y2264X). This nonsense mutation causes skipping of exon 37 during the splicing process and is predicted to result in a protein shortened by 34 amino acid residues. The mutation was detected in all tissues examined (blood lymphocytes, oral mucosa, and dermal fibroblasts). The same mutation was previously found in 3 patients with clinically confirmed NF1. To our knowledge, this is the first report of an adult patient carrying a putative (non-mosaic) NF1 gene mutation in multiple tissues but not fulfilling the NIH criteria for the clinical diagnosis of NF1. Am. J. Med. Genet. 86:328–330, 1999.     

促血管生成素表达与人脑胶质瘤血管生成的关系研究

目的:研究促血管生成素(angiopoie-tins,Angs)蛋白表达水平与血管内皮生长因子(vascular endothelial growth factar,VEGF)和肿瘤内微血管密度(microvascular density,MVD)的关系,探讨其在人脑胶质瘤血管生成中的作用。方法:采用免疫组化方法检测42例人脑胶质瘤组织中Ang-1、Ang-2和VEGF的蛋白表达水平,并以抗CD34单克隆抗体显示血管内皮细胞,根据CD34阳性的血管计数来判定MVD。结果:42例人脑胶质瘤中,Ang-1+肿瘤的MVD比Ang-1-肿瘤高,但两者差异无统计学意义,P=0·156;Ang-2-和Ang-2+平均MVD分别是27·67和49·63,Ang-2+肿瘤MVD显著高于Ang-2-肿瘤,P=0·000。VEGF阳性表达时,Ang-2+肿瘤平均MVD显著高于Ang-2-肿瘤,分别为56·00和36·75,P=0·001;而VEGF阴性组中,Ang-2+肿瘤平均MVD与Ang-2-肿瘤几乎相等,分别为53·17和47·36,P=0·109。随胶质瘤恶性程度增加,Ang-1和Ang-2阳性表达率均升高,但Ang-2升高更明显,不同级别间Ang-2表达水平差异有统计学意义。结论:Ang-2高表达与人脑胶质瘤血管新生密切相关,Ang-2可以作为评价胶质瘤血管生成及恶性程度的一个重要指标。VEGF存在时,Ang-2过表达可促使肿瘤血管生成。肿瘤防治杂志,2005,12(19):1472-1475     

缓激肽对大鼠脑微血管内皮细胞和星形胶质细胞及胶质瘤细胞影响的体外研究

目的:体外探讨缓激肽(bradykinin,BK)的作用靶点细胞及BK选择性开放血脑屏障的可能机制。方法:通过免疫荧光测定脑血管内皮细胞、胶质细胞及C6细胞在不同剂量BK作用前后的细胞内钙离子变化,并且通过WesternBlot测定三组细胞的BKB2受体表达水平。结果:小剂量BK可以引起肿瘤细胞内的钙离子水平升高,而只有大剂量BK才能触发星形胶质细胞内的钙离子水平变化,脑血管内皮细胞对大、小剂量BK均无任何反应;三组细胞BKB2受体的WesternBlot整合密度值(integrateddensityvalue,IDV)分别为5000.12±1110.21(n=2)、18480.88±4119.86(n=3)和63032.13±2802.71(n=4),组间比较差异有统计学意义。结论:BK的直接作用靶点是星形胶质细胞及肿瘤细胞,两种细胞B2受体表达水平差异是小剂量BK选择性开放血肿瘤屏障的物质基础;BK可能通过某些细胞间信使起到调节脑血管内皮细胞通透性的作用。