Postsynaptic and presynaptic effects of the calcium chelator BAPTA on synaptic transmission in rat hippocampal dentate granule neurons.

When applied to rat hippocampal slices, the permeable calcium chelator, BAPTA-AM, caused a reduction of both post-spike train slow afterhyperpolarizations (AHPs) and spike-frequency adaptation in dentate granule cells. This indicated that BAPTA-AM can, like microinjected EGTA, block calcium-activated potassium channels. At perforant pathway synapses, BAPTA-AM caused a reduction of inhibitory postsynaptic potentials (IPSPs) and an initial increase and later decrease of excitatory postsynaptic potentials (EPSPs). The initial increase in EPSPs may be caused by presynaptic spike-broadening owing to inhibition of calcium-activated potassium channels which normally regulate the duration of the presynaptic action potential. These channels may be affected at lower doses of chelator than synaptic transmitter release. BAPTA salt injected into individual dentate granule cells caused, as expected, decreased AHPs and spike-frequency adaptation. Also, paradoxically, both excitatory and inhibitory synaptic potentials were increased although input resistance was not.     

骨形态发生蛋白4转基因治疗大鼠的胫骨缺损

目的:观察基因工程技术构建人骨形态发生蛋白4复制缺陷腺病毒的成骨效果。方法:实验于2006-03/08在安徽医科大学第一附属医院实验动物中心完成。实验分组:选取普通级雄性SD大鼠30只,体质量(200±10)g,全部动物胫骨上端部分分别造成8mm×5mm长方形缺损。采用自身对照法,右侧骨缺损为实验组,左侧骨缺损为对照组。实验组植入人骨形态发生蛋白4复制缺陷腺病毒复合明胶海绵,对照组植入单纯明胶海绵。实验评估:术后分别于4,6,8周麻醉后处死10只动物,取材行X线、组织病理、免疫组织化学、透视电镜检查,观察成骨情况。结果:纳入30只大鼠,全部进入结果分析。①大鼠胫骨缺损X线、组织病理学检查结果:术后8周实验组和对照组骨缺损均得到修复,但实验组无论从成骨时间、成骨效果、新生骨量等方面都要优于对照组。其中各时间点实验组骨密度明显高于对照组,差异有显著性意义[4周:(95.91±16.33),(87.93±11.52);6周:(128.34±10.64),(102.41±9.81);8周:(138.36±10.49),(121.56±9.63);P<0.01]。各时间点实验组新生骨占骨缺损面积比明显高于对照组,差异有显著性意义[4周:(41.39±5.65)%,(26.58±5.62)%;6周:(80.35±7.25)%,(65.41±6.52)%;8周:(96.45±2.76)%,(82.22±7.30)%;P<0.01]②术后4周免疫组织化学染色结果:实验组软骨及骨痂内呈强阳性反应,而对照组骨痂内骨形态发生蛋白4表达微弱。结论:人骨形态发生蛋白4重组腺病毒具有良好的成骨活性,骨形态发生蛋白4直接转基因治疗能够加快骨缺损的修复。     

Severe Cerebral Venous and Sinus Thrombosis: Clinical Course,Imaging Correlates,and Prognosis

Background

Severe cerebral venous-sinus thrombosis (CVT) is a rare disease, and its clinical course, imaging correlates, as well as long-term prognosis have not yet been investigated systematically.

Methods

Multicenter retrospective study. Inclusion criteria were CVT, Glasgow coma scale ≤9, and treatment in the intensive care unit. Primary outcome was death or dependency, assessed by a modified Rankin Score (mRS) >2 at last follow-up.

Results

114 patients were included. At last follow-up (median 2.5 years), 38 patients (33.3 %) showed no or minor residual symptoms (mRS = 0 or 1), 12 (10.5 %) had a mild (mRS = 2), 13 (11.4 %) a moderate (mRS = 3), 12 (10.5 %) a severe disability (mRS = 4 or 5), and 39 (34.2 %) had died. In bivariate analysis, predictors of poor outcome were any signs of mass effect on imaging, clinical deterioration after admission, and age. In contrast, clinical symptoms on admission and parenchymal lesions per se, such as edema, infarction, or hemorrhage were not predictive. Multivariate predictors of poor outcome were an increase in National Institutes of Health Stroke Scale ≥3 after admission [odds ratio (OR) 6.7], bilateral motor signs in the further course (OR 9.2), and midline shift (OR 5.1).

Conclusion

The outcome of severe CVT is almost equally divided between severe impairment or death and survival with no or only mild handicap. Specifically, space-occupying mass effect and associated neurologic deterioration seem to determine a poor outcome. Therefore, early detection and treatment of mass effect should be the focus of critical care.

     

两种荧光显微成像系统亚细胞定位的对比

目的:应用高分辨率荧光显微成像系统采集细胞器探针图像,并与激光共聚焦显微成像系统进行对比。方法:实验于2003-05/2004-01在解放军总医院完成。①实验材料:鼠肺毛细血管内皮细胞株(1H11)由上海复旦张江生物公司提供;荧光探针Rhodamine-123,Lucifer Yellow,DiOC6[3],BODIPY(美国Sigma公司)。②细胞培养及荧光探针染色:细胞培养采用含体积分数为0.2胎牛血清的低糖DMEM培养基,密度5×107L-1。选择Rhodamine-123作为细胞线粒体特异性荧光探针,选择DiOC6[3]作为细胞内质网特异性荧光探针,选择BODIPY作为细胞高尔基体特异性荧光探针,选择Lucifer Yellow作为细胞溶酶体探针。前3个探针在完全避光条件下与培养的细胞共同孵育0.5h,后者则共同孵育15h。③高分辨率荧光成像系统的图像采集:线粒体荧光图像采集,选取经Rhodamine-123共孵育完成的细胞,选择激发滤色镜为BP460-490,吸收滤色镜为BA515,分光镜为DM500,另加一绿通道液晶滤光片,激发出Rhodamine-123的荧光。电荷耦合器件采集图像并送入计算机。重复上述步骤,采用DiOC6[3]标记内质网,BODIPY标记高尔基体,Lucifer Yellow标记细胞溶酶体,激发条件同Rhodamine-123。分别采集同一视野靶细胞DiOC6[3]、BODIPY或Lucifer Yellow的荧光图像,完成全部图像采集并储存在计算机中。④激光共聚焦显微成像系统的图像采集:选择经4种探针染色的靶细胞,使用氩离子激光器在488nm激发Rhodamine-123,Rhodamine-123荧光通过配置有530/60-G发射滤光片的通道1探测。重复上述步骤,在488nm激发DiOC6[3]和BODIPY,在457nm激发Lucifer yellow,3种荧光均由通道1探测,后2个探针的发射滤光片的配置为515/30-G,DiOC6[3]选择530/60-G。由光电倍增管接收信号并传输入计算机成像。结果:①高分辨率荧光成像系统所采集图像,靶细胞中由荧光探针Rhodamine-123染色的线粒体呈多个典型的小棒状或卵圆状,聚集在核周;Lucifer yellow染色的溶酶体呈多个非对称球型,在胞浆内随机分布,颗粒尺寸通常大于线粒体;荧光探针DiOC6[3]着色的内质网占据胞浆的很大空间,以囊状聚集为特征;BODIPY特异性地结合在高尔基体上,荧光图像显示围绕在细胞核周围呈条索状。②与高分辨率荧光成像系统比较,激光共聚焦显微成像系统所采集的图像其荧光强度基本相同,但分辨率低、细节显示模糊、胞浆中细胞器的准确分布信息和形态特征显示效果欠佳。结论:两种荧光显微成像系统均可采集到细胞器探针的荧光图像。但高分辨率荧光成像系统采集的荧光图像具有细节清晰、分辨度高、准确显示胞浆中细胞器的分布信息和形态特征等优点。     

Linkage of a tumor immune function and cell cycle de-regulation via a gene regulatory network subcircuit

Gene regulatory network (GRN) subcircuits have been described for cell fate progressions in animal development. The hallmark of these subcircuits is the integration of promoters, and positive- and negative-acting promoter binding proteins, such that an alteration in function of any one member of the defined subcircuit, occurring with a change in cell fate, defines a change in status for all other members of the subcircuit. Here we describe a GRN subcircuit that links a tumor immune function with cell cycle de-regulation. All members of this subcircuit have a predictable status change in response to rescue of the growth-controlled phenotype. Given the similarities between the molecular mechanisms underlying cell status changes in tumorigenesis and development, application of GRN paradigms to tumor progression is particularly apt and offers the hope of providing a more concise, reliable, and therapeutically useful series of predictions linking gene regulation and tumor progression.     

Malformations of the posterior fossa: current perspectives

Posterior fossa malformations are a special group of central nervous system anomalies that present during infancy with hypotonia, developmental delay, microcephaly, or hydrocephalus. Recent discoveries of the genetic and epigenetic factors that control hindbrain ontogenesis explain some of these disturbances in cerebellar development. A comprehensive classification of posterior fossa malformations is proposed with particular attention to Dandy-Walker malformation, Joubert syndrome, and other cerebellar hypoplasias. A rare form of cerebellar hypertrophy which caused repeated obstruction at the foramen magnum is recognized. The importance of the cerebellum in language, cognition, and brain growth is stressed.     

β-锗代-α-氨基酸衍生物的合成及抗肿瘤活性

自六十年代初期发现羧乙基锗倍半氧化物(Ge—132)广泛的生物活性以来,已有许多相应的有机锗化合物被发现,在抗肿瘤活性方面,因有毒性较低、抗瘤谱广等一系列优点而引起人们广泛的兴趣,但由于活性较低影响了应用及发展,据文献报道,有机锗倍半氧