Previous studies show that chronic acrylamide exposure leads to central and peripheral neu-ropathy. However, the underlying mechanisms remained unclear. In this study, we examined the permeability of the blood-cerebrospinal lfuid barrier, and its ability to secrete transthyretin and transport leptin of rats exposed to acrylamide for 7, 14, 21 or 28 days. Transthyretin levels in cerebrospinal lfuid began to decline on day 7 after acrylamide exposure. The sodium lfuorescein level in cerebrospinal lfuid was increased on day 14 after exposure. Evans blue concentration in cerebrospinal lfuid was increased and the cerebrospinal lfuid/serum leptin ratio was decreased on days 21 and 28 after exposure. In comparison, the cerebrospinal lfuid/serum albumin ratio was increased on day 28 after exposure. Our ifndings show that acrylamide exposure damages the blood-cerebrospinal lfuid barrier and impairs secretory and transport functions. These changes may underlie acrylamide-induced neurotoxicity.

Ischemic edema can alter the structure and permeability of the blood-brain barrier. Recent stud-ies have reported that progesterone reduces cerebral edema after cerebral ischemia. However, the underlying mechanism of this effect has not yet been elucidated. In the present study, pro-gesterone effectively reduced Evans blue extravasation in the ischemic penumbra, but not in the ischemic core, 48 hours after cerebral ischemia in rats. Progesterone also inhibited the down-reg-ulation of gene and protein levels of occludin and zonula occludens-1 in the penumbra. These results indicate that progesterone may effectively inhibit the down-regulation of tight junctions, thereby maintaining the integrity of the blood-brain barrier and reducing cerebral edema.

定量动态增强 MRI 在脑高低级别胶质瘤术前病理分级中的应用研究

目的：探讨定量动态增强 MRI（T1-DCE MRI）在脑高低级别胶质瘤术前病理分级中的应用价值。方法选择经手术病理证实的30例脑胶质瘤患者为研究对象，其中低级别（WHOⅠ、Ⅱ级）胶质瘤15例，高级别（WHO Ⅲ、Ⅳ级）胶质瘤15例。全部病例均行3T 常规 MR 增强及 MR 灌注成像检查，原始灌注图像数据经工作站软件处理，构建容量转移常数（Ktrans ）、回流速率常数（Kep ）、血管外细胞外容积分数（Ve ）图，选择 ROI，计算 Ktrans 、Kep 和 Ve 值。高低级别胶质瘤 Ktrans 、Kep 和 Ve 值与病理分级进行 Pearson 相关性分析。结果Ktrans 、Kep 和 Ve 值与病理学分级具有明显相关性（r＝0．934，0．837，0．807）。各参数高低级别胶质瘤患者间比较有明显的统计学差异，随着肿瘤级别的增高，Ktrans 、Kep 和 Ve 值增高。结论通过 Permeability 技术测量肿瘤血管 Ktrans 、Kep 和 Ve 值，可以了解肿瘤微血管灌注状态，对高低级别胶质瘤进行较为精确的术前分级。

乙酰唑胺和anordiol对注射水通道蛋白1-cRNA的爪蟾卵母细胞渗透水通透性的影响

AIM: To study the effects of acetazolamide and anordiol on osmotic water permeability in aquaporin 1 (AQP1)-cRNA injected Xenopus oocyte and their mechanisms. METHODS: AQP1 gene constructed in pBluescript was transcripted into cRNA in vitro and then the cRNA was injected in Xenopus oocytes. The effects of acetazolamide and anordiol on the water transport function of AQP1 were observed by assaying the osmotic swelling of oocytes.In addition, their effects on protein expression of AQP1 were quantitatively investigated by Western blotting method.RESULTS: After incubation for 15 min or 72 h, acetazolamide, a carbonic anhydrase inhibitor, equally reduced the water permeability of AQP1-cRNA injected oocyte in a dose-dependent manner. After incubation for 72 h, anordiol,an antiestrogen with partial estrogenic activity, reduced the osmotic water permeability dose dependently as well;however, no discernable action was observed after incubation with anordiol for 15 min. The Western blotting analysis showed that acetazolamide did not influence the protein expression of AQP1. However, after incubation for 72 h with anordiol (10 μmol/L), the quantity of AQP1 in the oocyte membrane was decreased dramatically (P＜0.05). CONCLUSION: Both acetazolamide and anordiol inhibited the osmotic water permeability of AQP1cRNA injected oocyte, but their mechanisms were different. Acetazolamide functionally inhibited the osmotic water permeability of AQP1, whereas anordiol primarily decreased the amount of AQP1 protein in the oocyte membrane.