4000/扩散张量成像对正常成人皮质脊髓束通路初步研究

目的：扩散张量成像（DTI）对健康成人皮质脊髓束通路的研究,分析不同部位皮质脊髓束通路FA值,为皮质脊髓束病理改变的研究提供正常解剖依据。材料与方法：健康成人30名, GE 1.5T及工作站行数据收集和后处理, 测量延髓、脑桥、大脑脚、基底节、放射冠及半卵园中心等层面的皮质脊髓束（CST）通路FA值。结果：延髓及半卵园中心平面的各层面FA值左右差异无显著性;脑桥、大脑脚、基底节、放射冠等水平面的各层面的FA值左右侧差异有显著性,可认为左侧较右侧高。结论：皮质脊髓束通路FA值左右侧在不同水平的层面上有差异,左侧高于右侧,可能与右利手有关。     

应用扩散张量和功能磁共振成像技术探讨皮质脊髓束与肌力的相关性

目的探讨脑梗死与脑肿瘤患者皮质脊髓束(corticospinaltract,CST)损伤对肢体肌力的影响。方法应用磁共振扩散张量成像(diffusiontensorimaging,DTI)和扩散张量纤维束成像(diffusiontensortractography,DTT)技术,并将DTI与功能磁共振成像(functionalMRimaging,fMRI)相结合,对脑梗死和脑肿瘤引起的皮质脊髓束损伤进行定位诊断,并观察皮质脊髓束损伤对患者肢体肌力的影响。对40例急性脑梗死(发病时间<72h)和113例脑肿瘤患者行MRI和扩散加权成像检查,其中部分患者再行增强扫描和fMRI检查。收集全部患者的磁共振扩散张量成像原始数据,然后行扩散张量纤维束成像,重建双侧皮质脊髓束,并将患侧皮质脊髓束的病理性改变对肢体肌力的影响进行相关性分析。结果(1)梗死区各向异性(FA)阈值为(0.336±0.065),对侧半球正常白质区FA阈值为(0.705±0.069),梗死白质区FA值显著低于健侧,两侧相比差异有显著性意义(t=15.823,P<0.001)。(2)扩散张量纤维束成像显示,脑梗死和脑肿瘤患者病变侧皮质脊髓束受压、变形、移位,部分断裂。(3)脑梗死皮质脊髓束损伤患者的肢体肌力降低率为67.50%(27/40),脑肿瘤为16.81%(19/113);组间差异有显著性意义(χ2=36.096,P<0.001)。(4)急性脑梗死和脑肿瘤累及皮质脊髓束内囊后肢致肌力降低率分别     

功能MRI和弥散张量纤维束示踪成像联合应用是评估脑出血患者躯体感觉功能恢复的有用工具？1例报告

研究背景：目前对中风之后的身体感觉机能障碍了解很少。 研究目的：我们试图证明应用功能性磁共振成像(fMRI)和扩散张量纤维束示踪(DTT)能使颅内出血(ICH)患者的身体感觉机能障碍康复。 研究设计,时间和地点：从2008年6月到11月在理疗与康复教研室进行病例研究。 参与人员：55岁的女患者,她起先右侧皮质和辐射冠自发性的颅内出血,造成左身严重的身体感觉机能障碍。 研究方法：应用PHILIPS公司Gyroscan Intera 1 .5 T扩散张量纤维束示踪系统和磁共振成像系统从开始之后的3-7周进行两个纵向评估。扩散张量纤维束示踪以分次的各向异性<0.2作为最终标准,磁共振成像通过手的触摸和被动运动来完成. 主要成果: 我们发现扩散张量纤维束示踪过程和磁共振成像上的皮质激活是伴随着身体感觉功能的恢复一起的. 研究结果: 受作用的一边在开始之后的第7周身体感觉功能会恢复到接近于正常的状态.从第3到7周的功能性磁共振成像上我们发现, 位于另一侧初级感觉皮质中心的皮质被活化.然而,在第3周的磁共振成像上却没有发生皮质激活功能而被动运动的激活功能在第7周比第3周显示的有所增强.在第3周对受创一侧(右侧)扩散张量纤维束示踪中我们没能发现内侧丘系.第7周的内侧丘系示踪, 一个内侧丘系沿着丘系内侧从辐射冠上升到初级感觉皮质. 结论: 我们证明了在这位患者的身体感觉机能恢复中应用到了功能性磁共振成像(fMRI)和扩散张量纤维束示踪(DTT). 我们推断在研究中风病人的身体感觉机能障碍的康复中功能性磁共振成像(fMRI)和扩散张量纤维束示踪(DTT)是有效的方法.     

磁共振扩散张量加权成像显示正常和病变肾脏的超微结构变化*☆

背景：磁共振弥散张量可对每个体素水分子扩散的各向异性作出准确的检测。利用扩散张量成像评价肾脏及其病变内水分子运动特征,可反映出肾组织超微结构的变化,有利于病变的早期诊断。 目的：验证磁共振扩散张量成像对正常肾脏和肾脏病变的临床诊断价值。 方法：选择健康对照组12例和24例肾脏病变患者行肾脏扩散张量成像检查,肾脏病变患者中肾癌7例,肾囊肿7例,肾积水10例。观察肾脏皮质、髓质以及病灶表观扩散系数、分数各向异性的变化,并行髓质纤维束成像。 结果与结论：正常肾脏中,肾皮质的表观扩散系数显著高于肾髓质(P=0.003),而肾髓质的分数各向异性显著高于肾皮质 (P < 0.05)。肾癌表观扩散系数低于正常肾皮质、髓质(P < 0.05),瘤体内分数各向异性显著低于正常肾髓质(P < 0.05)。肾囊肿表观扩散系数显著高于正常肾皮质、髓质(P < 0.05),分数各向异性显著低于肾皮质和髓质(P < 0.05)。扩散张量纤维束示踪图可重建出肾髓质纤维束的形态,从而反映出肾小管和集合管的结构变化。提示扩散张量成像能显示正常肾脏和肾脏病变的超微结构变化,可用于肾脏病变的早期诊断和病情监控。 关键词：磁共振;弥散;张量;肾脏病变;正常肾脏     

继发于脑桥缺血性卒中的双侧小脑中脚Wallerian变性

正Wallerian变性系轴索顺行性崩解及其所属髓鞘变性的过程,是继发于神经元胞体和近端轴索损伤的退行性变,最常累及皮质脊髓束和皮质脑桥束,累及脑桥-小脑通路者并不少见,但鲜为人所熟知。脑桥小脑束起源于对侧脑桥核(位于脑桥基底部),接受皮质脑桥束的传入,在脑桥上部水平交叉过中线,经小脑中脚达小脑皮质。当损害发生在一侧脑桥时,同侧脑桥核、     

DTI在基底核区脑出血病人运动功能恢复评估及康复机制研究的应用进展

基底核区脑出血病人常出现不同程度的运动功能障碍,皮质脊髓束（CST）损伤是致残的重要机制。弥散张量成像（DTI）作为目前惟一可活体研究CST的无创成像技术,可以直观评估病人运动功能的恢复,并能从传导束角度探寻运动功能康复的机制。     

弥散张量成像在高血压性脑出血中的临床应用初探

目的 应用磁共振弥散张量成像技术观察基底节区高血压性脑出血皮质脊髓束的受损情况,为临床干预治疗提供可靠依据.方法 对9例基底节区HICH患者进行磁共振弥散张量成像检查,分别测量患侧皮质脊髓束受压区及健侧皮质脊髓束相应区域的FA值,并重建一名患者的FA图、方向编码彩色图、双侧皮质脊髓束3D纤维束图.结果 患侧皮质脊髓束的FA值均较对侧降低,两侧相比差异有显著性意义(t=4.9041,P<0.05);患侧皮质脊髓束区FA值下降百分比和NIHSS评分有明显相关性(r=0.8336,P<0.05);皮质脊髓束3D纤维束图可显示病变侧皮质脊髓束受损情况.结论 通过弥散张量成像可以了解基底节区HICH患者的皮质脊髓束的损伤情况,这有助于临床医生全面掌握病情,开展干预性治疗.     

磁共振扩散张量技术在肥大性下橄榄核变性诊断中的应用(1例报道及文献复习)

目的报道1例继发于脑桥出血的肥大性下橄榄核变性病例并复习相关文献,论证头颅磁共振扩散张量成像(MR DTI)和弥散张量纤维束成像(DTT)技术用于肥大性下橄榄核变性诊断的临床价值和意义。方法收集1例患有眼肌阵挛和步态异常的男性39岁患者的临床资料。该患者分别接受MRI和DTI检查。结果 MRI显示其延髓右前外侧肥大结节灶,呈T1WI等信号、T2WI高信号、DWI高信号。MR DTI和DTT显示:(1)ADC值右侧大于左侧;(2)FA值右侧小于左侧;(3)右侧神经纤维束相对左侧减少变薄并部分呈现中断现象。结论 MR DTI和DTT在诊断肥大性下橄榄核变性时一定程度上优于常规MRI,影像学的发展提高了肥大性下橄榄核变性的诊断和鉴别诊断水平。     

基于小脑通路的弥散磁共振成像分析

目的探讨小脑-大脑皮层通路的白质连接模式。方法于2015年10月-2016年4月通过电子科技大学校园网公开招募20名健康被试并采集所有被试的弥散磁共振(dMRI)数据,通过概率性示踪法重建出小脑-大脑皮层之间的白质纤维束通路,包括齿状核-红核-丘脑-皮层(DTC)、额叶-脑桥-小脑(FPC)、顶叶-脑桥-小脑(PPC)、颞叶-脑桥-小脑(TPC)和枕叶-脑桥-小脑(OPC)。考察这些通路白质微结构的弥散参数,包括各向异性分数(FA)、平均扩散度(MD)、横向扩散度(AD)和径向扩散度(RD)。利用配对t检验考察各个纤维束弥散参数的对称性。结果在20名被试中均成功追踪出5组白质纤维束。DTC和OPC的各个参数均显示为双侧对称;TPC和PPC的FA存在不对称性,左侧高于右侧,差异有统计学意义(P0.05);左侧FPC和右侧PPC的RD值较对侧高,差异均有统计学意义(P0.05)。结论弥散磁共振数据能有效重构小脑-大脑间的白质纤维束,作为小脑输出纤维(DTC)的弥散参数具有双侧对称性。而额叶、顶叶、颞叶向小脑的输入纤维均显示双侧不对称性,这可能反映了小脑参与大脑非运动功能的不对称性。     

成人视放射弥散张量纤维束示踪成像的临床应用研究

目的 常规的影像手段对视放射纤维束的成像、分析缺乏特异性,为了弥补常规影像检查的不足,应用弥散张量成像(DTI)和弥散张量纤维束示踪成像(DTT)研究成人视放射的各向异性程度和视放射纤维束的构象特征.方法 对20例正常视放射和24例视放射区域病变的患者进行MR常规及DTI序列检查,分别测量双侧视放射区的部分各向异性(F...     

星形胶质细胞对天冬氨酸特异性半胱氨酸蛋白酶介导β淀粉样蛋白早期突触毒性作用的影响

目的探讨星形胶质细胞(astrocyte,AS)对天冬氨酸特异性半胱氨酸蛋白酶(cysteinyl aspartate specific proteinase,caspase)介导β淀粉样蛋白(β-amyloid,Aβ)早期突触毒性作用的影响,以期为进一步研究与血管性痴呆(vascular dementia,Va D)的发病机制奠定基础。方法以原代培养大鼠海马纯神经元体系(NE-S)及混合培养体系(MIX-S,主要包含神经元及AS)为研究对象,各体系分为6组:对照组、caspase-8抑制剂组、caspase-9抑制剂组、Aβ处理组、caspase-8抑制剂预处理加Aβ组和caspase-9抑制剂预处理加Aβ组。免疫荧光检测各组近胞体10μm段树突中突触后密度蛋白(postsynaptic density-95,PSD95)表达量的变化。结果 1在NE-S与MIX-S中,与对照组相比,caspase-8抑制剂组、caspase-9抑制剂组PSD95的表达量均无明显差异,Aβ处理组PSD95的表达量均显著降低(P均0.001)。2在NE-S中,与Aβ处理组相比,caspase-9抑制剂预处理加Aβ组PSD95的表达量显著回升至对照组水平,caspase-8抑制剂预处理加Aβ组则无显著改变;在MIX-S中的结果则相反,即caspase-8抑制剂预处理加Aβ组PSD95的表达量显著回升至对照组水平,而caspase-9抑制剂预处理加Aβ组则无显著改变。3MIX-S与NE-S两种培养系统间相比较,对照组间及Aβ处理组间PSD95的表达量均无显著差异,而caspase-8抑制剂预处理加Aβ组间及caspase-9抑制剂预处理加Aβ组间PSD95的表达量差异有显著性。结论在Aβ早期突触毒性作用中,AS参与caspase-8介导的死亡受体通路激活过程,且参与抑制神经元的线粒体通路。     

Impact of pediatric traumatic brain injury on hippocampal neurogenesis

Traumatic brain injury(TBI) is a major cause of mortality and morbidity in the pediatric population. With advances in medical care, the mortality rate of pediatric TBI has declined. However, more children and adolescents are living with TBI-related cognitive and emotional impairments, which negatively affects the quality of their life. Adult hippocampal neurogenesis plays an important role in cognition and mood regulation. Alterations in adult hippocampal neurogenesis are associated with a variety of neurological and neurodegenerative diseases, including TBI. Promoting endogenous hippocampal neurogenesis after TBI merits significant attention. However, TBI affects the function of neural stem/progenitor cells in the dentate gyrus of hippocampus, which results in aberrant migration and impaired dendrite development of adult-born neurons. Therefore, a better understanding of adult hippocampal neurogenesis after TBI can facilitate a more successful neuro-restoration of damage in immature brains. Secondary injuries, such as neuroinflammation and oxidative stress, exert a significant impact on hippocampal neurogenesis. Currently, a variety of therapeutic approaches have been proposed for ameliorating secondary TBI injuries. In this review, we discuss the uniqueness of pediatric TBI, adult hippocampal neurogenesis after pediatric TBI, and current efforts that promote neuroprotection to the developing brains, which can be leveraged to facilitate neuroregeneration.     

基于PEO模式的家庭作业治疗对卒中偏瘫患者功能预后的影响

目的 研究基于人-环境-作业（person-environment-occupation,PEO）模式的家庭作业治疗对卒中偏瘫患者上肢功能、日常生活活动能力及生活质量的影响。方法 前瞻性、连续纳入2020年1月—2020年12月南京市浦口人民医院（原南京市浦口区中心医院）康复医学科出院的卒中偏瘫患者,随机分为试验组和对照组,并分别建立微信群聊,对照组定期更新康复小视频,有任何问题随时咨询。试验组基于PEO模式,个性化更新每位患者的小视频,两组分别于出院时、出院3个月、6个月和12个月分别进行Fugl-Meyer运动功能量表上肢部分（Fugl-Meyer assessment upper extremity scale,FMA-UE）、日常生活活动能力Barthel指数（Barthel index,BI）及卒中专用生活质量量表（stroke-specific quality of life scale,SS-QOL）的评定。结果 最终纳入卒中偏瘫患者60例,平均年龄（63.10±6.83）岁,其中男性30例。将入组患者随机分为对照组和试验组各30例。组内比较显示,试验组出院3个月BI评分...     

ACS Chemical Neuroscience Molecule Spotlight on Dimebon

Dimebon (latrepirdine) is an antihistamine drug that has been used clinically in Russia since the early 1980s and is being studied jointly by Pfizer and Medivation for patients with Alzheimer's disease. The results from a pivotal Phase 3 clinical trial (CONNECTION) showed that Dimebon (latrepirdine) failed to meet its coprimary or secondary efficacy end points.     

The effects of cocaine on light-induced activity

Cocaine is a major stimulant drug which can have rewarding and locomotor activating effects. It is used by non-addicts to enhance concentration and performance in a work or social setting. It was suggested that cocaine may amplify the impact of mood and sensory stimulation on behaviour. Here we tested whether cocaine can enhance the impact of novel sensory stimulation on exploratory locomotor activity. In this study the effects of cocaine (0, 2.5, 5.0, 10 mg/kg, i.p.) on the locomotor response induced by on-off light stimulation with different light intensities (0, 22, 83, 440 lx) was investigated. Visual stimulation increased locomotor activity and grooming behaviour. Cocaine more dramatically increased locomotion and rearing behaviour but suppressed grooming. Also, visual stimulation effects on grooming were reduced by cocaine. The additive relationship between the cocaine and visual stimulation effects on locomotion and rearing combined with their opposing impact upon grooming point to independent mechanisms mediating cocaine- and visual stimulation-induced behavioural activation.     

Effects of Lithium on Inflammation

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Differential effects of dopamine melanin on norharman-induced toxicity in PC12 cells

Summary The food contaminant norharman structurally resembles MPTP a compound that selectively damages pigmented brain areas. Both compounds are sequestered and retained in melanin-containing neurons. The aim of the study was to examine whether intracellular melanin can modulate the toxicity of norharman in melanin-loaded PC12 cells. Dopamine melanin protected against norharman-induced upregulation of grp78, activation of caspase 3 and necrosis at low concentrations (5 and 50 μM). In contrast, at a high conentration (500 μM) there was a significantly increased expression of grp78, hsp90 and caspase 3 and a disassociation of melanin aggregates leading to dispersal of granules to swollen neurite terminals. In human populations, a long-term low-level exposure to toxicants with a high affinity to melanin will probably result in accumulation in melanin-containing neurons in vivo. Our data suggest that accumulation of a neurotoxicant in melanin-loaded cells may lead to increased cell stress, apoptotic signaling and disassociation of melanin aggregates.     

Computational study on effect of red blood cells on primary thrombus formation

The primary thrombus formation is a critical phenomenon both physiologically and pathologically. It has been seen that various mechanical factors are involved the regulation of primary thrombus formation through a series of physiological and biochemical processes, including blood flow and intercellular molecular bridges. However, it has not been fully understood how the existence of red blood cells contributes to the process of platelet thrombus formation. We computationally analyzed the motions of platelets in plasma layer above which red blood cells flow assuming a background simple shear flow of a shear rate of 1000 s(-1) using Stokesian dynamics. In the computation, fluid mechanical interactions between platelets and red blood cells were taken into account together with the binding forces via plasma proteins between two platelets and between a platelet and injured vessel wall. The process of the platelets aggregation was significantly dependent on whether red blood cells were present. When red blood cells were absent, the aggregate formed grew more vertically compared to the case with red blood cells. Conversely, when red blood cells were present, the aggregate spread more horizontally because the red blood cells constrained the vertical growth when the height of the aggregate reached the level of the red blood cells. Our results suggest that red blood cells mechanically play a significant role in primary thrombus formation, which accelerates the horizontal spread of the thrombus, and point out the necessity of considering the presence of red blood cells when investigating the mechanism of thrombus formation.     

Effects of immune activation on the retrieval of spatial memory

Objective

It has been shown that there are extensive interactions between the central nervous system and the immune system. The present study focused on the effects of lipopolysaccharide (LPS) on memory retrieval, to explore the interaction between immune activation and memory.

Methods

C57BL/6J mice (8 weeks old) were first trained in the Morris water maze to reach asymptotic performance. Then mice were tested 24 h after the last training session and LPS was administered (1.25 mg/kg, i.p.) 4 h prior to the testing. The retrieval of spatial memory was tested by probe trial, and the time spent in the target quadrant and the number of platform location crosses were recorded. ELISA was performed to detect interleukin-1β (IL-1β) protein level in the hippocampus of mice tested in the water maze.

Results

Although LPS induced overt sickness behavior and a significant increase in the level of IL-1β in the hippocampus of mice, there was no significant difference in the time spent in the target quadrant or in the number of platform location crosses between LPS-treated and control groups in the probe trial testing.

Conclusion

Immune activation induced by LPS does not impair the retrieval of spatial memory.