~(125)I粒子永久性组织间植入内放射治疗大肠癌的研究进展

大肠癌是世界范围内最常见的癌症之一,在西方社会其发病率排在肿瘤的第2位,在我国的消化道肿瘤中排第4位。尽管手术、放疗、化疗技术不断提高,但5年生存率低于50%。随着科学技术的发展,125I粒子永久性组织间植入内放射已成为大肠癌治疗的新方法,本文综述了125I粒子永久性组织间植入内放射治疗大肠癌的研究进展。     

How to trace stem cells for MRI evaluation?

Applications of imaging techniques to visualize stem cells for monitoring, control and treatment of biological systems, in particular the brain, is at the forefront of investigations. These approaches involve the identification of stem and precursor cells that may be of various origins, but are related to specific clinical conditions, and the choice of the appropriate markers to achieve the required imaging while minimizing the side effects. This article will review examples of the contrast agent design for rational approaches in stem cell imaging. Potential pitfalls or side effects associated with contrast agents, in particular iron oxide nanoparticles, for cell labelling are also discussed.     

Can serotonin transporter genotype predict serotonergic function,chronicity, and severity of drinking?

Serotonin transporter (5-HTT) activity is greater in carriers of the long (L) vs. short (S) alleles of the 5-HTT-linked polymorphic region (5'-HTTLPR) among healthy control subjects but not alcohol-dependent adults. In 198 alcoholics, we determined the relationship between current or lifetime drinking and platelet 5-HTT function and density among allelic variants of the 5'-HTTLPR. SS subjects were younger than L-carriers (LL and LS) (p<0.0085) and had fewer years of lifetime drinking. For L-carriers, the mean of Bmax for paroxetine binding, but not Vmax for serotonin (5-HT) uptake, was lower than that for SS subjects (p<0.05). More L-carriers than their SS counterparts had Vmax for 5-HT uptake below 200 nmol/10(7) platelets-min (p<0.05) and Bmax for paroxetine binding below 600 nmol/mg protein (p<0.06). Current drinking (drinks per day during the past 14 days) correlated positively with Km and Vmax of platelet 5-HT uptake (p<0.05) and negatively with Bmax, but not Kd, of paroxetine binding (p<0.05) for L-carriers alone. Years of lifetime drinking correlated negatively with Km and Vmax of platelet 5-HT uptake (p<0.05) and B(max), but not Kd, of paroxetine binding (p<0.05) for L-carriers alone. Among L-carriers alone, there were higher levels of platelet 5-HT uptake and lower levels of platelet paroxetine binding with increased drinking, and more lifetime drinking was associated with modestly lower levels of 5-HT uptake and paroxetine binding. Thus, 5-HTT expression varies with current and lifetime drinking in L-carriers alone.     

Loss of thalamic serotonin transporters in early drug-naïve Parkinson’s disease patients is associated with tremor: an [<Superscript>123</Superscript>I]β-CIT SPECT study

In vitro studies revealed serotonin transporter (5-HTT) decline in Parkinson’s disease (PD). Yet, few studies investigated thalamic 5-HTT in vivo and its effect on PD heterogeneity. We analyzed thalamic [¹²³I]β-CIT binding (mainly reflecting 5-HTT binding) in 32 drug-naïve PD patients and 13 controls with SPECT. Twenty-six patients were examined twice (17 months apart). Based on UPDRS scores, we identified subgroups of patients with moderate/severe tremor (PD_T) and without tremor (PD_WT) at the time of clinical diagnosis. Additionally, depressive symptoms were evaluated using the Beck Depression Inventory (BDI) at baseline. Mean thalamic specific to non-specific [¹²³I]β-CIT binding ratio was lower in patients when compared to controls, and further decreased during follow-up. At baseline, average thalamic ratio was significantly lower in the PD_T than in the PD_WT subgroup. No correlation was found between BDI scores and thalamic binding ratios. Our findings show decline of [¹²³I]β-CIT binding to thalamic 5-HTT in PD and its possible contribution to tremor onset.     

Nigrostriatal involvement in ataxia with oculomotor apraxia type 1

Ataxia with oculomotor apraxia type 1 (AOA1) is a rare autosomal recessive neurodegenerative disease, recently associated with mutations in the aprataxin gene. Main features are early onset cerebellar ataxia, oculomotor apraxia and peripheral neuropathy. The presence of choreoathetosis or dystonia in some patients suggests basal ganglia involvement, but these structures appear preserved in a single case in which neuropathological examination was performed. To evaluate in vivo the nigrostriatal function we studied dopamine transporter (DAT) density with [¹²³I] 2beta-carbometoxy-3beta-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (FPCIT)-SPECT in four AOA1 patients and eight healthy volunteers. All patients showed ataxia and neuropathy; only one had chorea and none had dystonia. Comparing with controls, AOA1 patients showed a slight reduction of the average striatal DAT density, which was bilateral and uniform in caudate and putamen. Nigrostriatal impairment occurred even in the absence of extrapyramidal features. Our data suggest subclinical involvement of basal ganglia in AOA1.     

Use of a single [<Superscript>123</Superscript>I]-FP-CIT SPECT to predict the severity of clinical symptoms of Parkinson disease

The aim of this study was to assess the ability of a single SPECT performed in the early stage of Parkinson’s disease (PD) to predict disease severity in 19 patients with early PD. [¹²³I]-FP-CIT striatal uptake was expressed as a ratio of specific:nonspecific uptake for defined brain areas. Clinical severity was determined by the UPDRS at baseline and 12–15 months following the SPECT procedure. [¹²³I]-FP-CIT uptake in the contralateral putamen and striatum was correlated with UPDRS score at baseline, with a more significant correlation after 1-year interval. [¹²³I]-FP-CIT uptake in all areas was correlated with bradykinesia and rigidity subscores only at follow up visit. Significant correlations were found between [¹²³I]-FP-CIT uptake in the contralateral striatum, putamen and caudate and the difference between motor scores of 1-year interval (ΔUPDRS). These results suggest that disease severity might be anticipated by a single SPECT at an early stage of the disease.     

神经干细胞与脑胶质瘤干细胞☆

所有的肿瘤组织并不是由均一的肿瘤细胞所组成的,不同的细胞具有不同的增殖、浸润和转移能力,亦即肿瘤的异质性。其中存在少数担当着干细胞角色的肿瘤细胞,具有干细胞的基本特性,包括自我更新能力、无限的增殖能力和多向分化潜能,为肿瘤干细胞。神经干细胞具有很强的自我更新机制,获得较少突变即有可能恶性转化,而且干细胞存活时间较长,这意味着干细胞比成熟细胞发生细胞复制的错误几率更大,因外界环境的刺激而发生突变的机会更多,最终形成脑胶质瘤干细胞,同时调节神经干细胞增殖和自我更新的基因在脑胶质瘤的脑胶质瘤干细胞中也表达,这也是支持神经干细胞是脑胶质瘤干细胞来源的;也有推测认为它可能起源于已分化的细胞,由这些细胞突变发生去分化得来,并通过基因突变而获得了干细胞自我更新的特性,从而形成脑胶质瘤干细胞。通过探讨神经干细胞与脑胶质瘤干细胞,为脑胶质瘤的治疗提供依据。     

改良Nash差速贴壁联合阿糖胞苷法体外分离培养大鼠嗅球及嗅黏膜源性嗅鞘细胞*☆

背景：目前常用的嗅鞘细胞培养方法有差速贴壁法、化学抑制法、抗体亲和吸附法、补体法等,各自均存在优缺点,单一使用某种方法时细胞纯化率较低。 目的：拟采用改良Nash差速贴壁+阿糖胞苷法体外分离纯化大鼠嗅球及嗅黏膜来源的嗅鞘细胞。 设计、时间及地点：细胞学体外对照观察,于2007-11/2008-05在武汉大学人民医院骨科实验室和消化内科实验室完成。 材料：10周龄Sprague-Dauley大鼠10只,由武汉大学人民医院实验动物中心提供,阿糖胞苷由武汉大学人民医院制备。 方法：完整取大鼠双侧嗅球及剪取鼻中隔后1/3嗅黏膜,剪碎后胰酶消化,制成单细胞悬液,按1×109 L-1密度接种于未包被的25 cm2玻璃培养瓶中,18~20 h后将细胞悬液转移至另一未包被的25 cm 2玻璃培养瓶中（第1次差速贴壁）,24 h后再将细胞悬液转移至经多聚右旋赖氨酸包被的25 cm2塑料培养瓶或经多聚右旋赖氨酸包被的6孔培养板中（第2次差速贴壁）,接种培养48 h后半量换液以去除杂细胞。在差速贴壁培养后二三天,加入3.0~5.0 pmol/L阿糖胞苷去除残余成纤维细胞。 主要观察指标：嗅鞘细胞的形态观察、分裂增殖情况、免疫荧光染色鉴定结果及纯度测定。 结果：体外培养24 h嗅球源性嗅鞘细胞即可贴壁,而嗅黏膜源性嗅鞘细胞多在培养四五天后贴壁,两种来源的嗅鞘细胞形态相似,以双极或梭形细胞为主,少量为3极及多突起形多级细胞,同时夹杂扁平、煎鸡蛋形细胞。纯化培养10 d的嗅鞘细胞,胶质纤维酸性蛋白、神经生长因子受体p75免疫荧光染色及神经生长因子受体p75+hoechs免疫荧光双染后大部分双极或多极细胞膜、胞体、突起呈阳性,细胞纯度可达90%以上。 结论：改良Nash差速贴壁+阿糖胞苷法可在体外成功分离培养出高纯度的嗅球及嗅黏膜源性嗅鞘细胞,嗅球源性嗅鞘细胞贴壁时间及分裂增殖程度优于嗅黏膜源性嗅鞘细胞。     

生物衍生骨与骨髓间充质干细胞复合修复兔桡骨大段缺损

背景：生物衍生支架材料具备与自身骨相似的结构和微环境,具有较好的应用前景。 目的：探讨生物衍生骨复合成骨诱导的骨髓间充质干细胞修复兔桡骨的节段性骨缺损的可行性,并与单纯生物衍生骨进行比较。 设计、时间及地点：随机对照动物实验,于2007-01/2008-01在南华大学生命科学院实验室完成。 材料：同种异体骨经脱脂、脱蛋白、部分脱钙和冻干等方法处理后制备生物衍生骨支架材料,与自体骨髓间充质干细胞复合制备组织工程骨支架材料。 方法：25只健康成年新西兰大白兔双侧桡骨制备中段15 mm的骨缺损,随机取其中20只兔右侧桡骨为实验组植入组织工程骨,左侧为对照组植入单纯生物衍生骨,不做内外固定;另5只兔双侧骨缺损处不植入任何材料作为空白组。 主要观察指标：应用X射线放射学检查及组织学观察比较3组骨缺损修复的能力。 结果：X射线显示随时间延长骨折处骨痂逐渐增多, 实验组8周基本愈合,12周塑形完成;对照组骨痂少,愈合时间推迟;空白组术后12周骨缺损未见骨性修复,最后形成骨不连。术后2,4,8,12周实验组放射学检查评价新骨生成优于对照组 (P < 0.05)。组织学检查显示实验组术后4周时材料开始吸收,8周基本降解吸收被新生骨取代,12周完全修复;对照组明显推迟,新骨生成速度、生成量低于实验组(P < 0.05);空白组各时点均无新骨形成,最后缺损由纤维组织充填。 结论：成骨诱导的间充质干细胞／生物衍生骨复合构建组织工程化骨植入修复兔桡骨缺损能够加速新骨形成,其修复能力明显优于单纯生物衍生骨。