Magnetic Resonance Imaging Findings in Patients with Tarsal Tunnel Syndrome

Tarsal tunnel syndrome (TTS) is a common entrapment syndrome whose diagnosis can be difficult. We compared preoperative magnetic resonance imaging (MRI) and operative findings in 23 consecutive TTS patients (28 sides) whose mean age was 74.5 years. The 1.5T MRI sequence was 3D T2* fat suppression. We compared the MRI findings with surgical records and intraoperative videos to evaluate them. MRI- and surgical findings revealed that a ganglion was involved on one side (3.6%), and the other 27 sides were diagnosed with idiopathic TTS. MRI visualized the nerve compression point on 23 sides (82.1%) but failed to reveal details required for surgical planning. During surgery of the other five sides (17.9%), three involved varices, and on one side each, there was connective tissue entrapment or nerve compression due to small vascular branch strangulation. MRI studies were useful for nerve compression due to a mass lesion or idiopathic factors. Although MRI revealed the compression site, it failed to identify the specific involvement of varices and small vessel branches and the presence of connective tissue entrapment.     

染铅大鼠铁过载致神经元损伤特殊染色法分析

目的探讨长期铅暴露大鼠铁过载对神经元的损伤。方法SD大鼠母代与子代分别设对照、低、高剂量铅暴露组（母代：800、1 500 mg/L,子代：300、900 mg/L 乙酸铅饮水方式染毒）连续70周;电感耦合等离子体发射光谱仪（ICP-AES）测血液和海马元素铅及铁,同部位海马石蜡切片分别行铁染色及硫堇染色并进行图片融合。结果染铅后,大鼠血和海马铅及海马铁含量均增加（P<0.01）;低、高剂量铅暴露组子代大鼠海马CA3区铁沉积IOD值分别为（5 930.71±2 517.68）和（1 1382.43±2 551.14）,均高于对照组的（3 786.78±1 256.37）,差异有统计学意义（P<0.01）;低、高剂量铅暴露组子代大鼠海马CA1区的神经元数量分别为（70.71±11.80）、（70.37±17.53）个/视野,均低于对照组的（83.71±12.60）个/视野,差异有统计学意义（P<0.01）;图像融合显示,染铅大鼠神经元内铁沉积增加而神经元数量及层数减少,损伤加重。结论基于铁染色和硫堇染色图像融合可直观地观察铅暴露大鼠铁过载部位神经元损伤。     

Yield-Point Phenomenon and Plastic Bands in Ferrite–Pearlite Steels

Lüders deformation is one type of discontinuous yielding in ferrite–pearlite steel. The yield-point phenomenon and localized plastic bands are two features of the Lüders phenomenon. It is believed that the yield-point phenomenon is related to the formation of plastic bands, but the correlation between them is unclear. In this study, this correlation was investigated by examining the global and local deformation behaviors in the tension processes of four ferrite–pearlite steels (carbon content, 0.05–0.3%; pearlite fraction, 1.2–32%) via an extensometer and digital image correlation (DIC) technique. The main obtained results are as follows: (1) the degree of yield drop decreased with an increase in the pearlite fraction (the magnitude of the yield stress drop was 8.6–0 MPa), and (2) a plastic band was formed at a certain stress level smaller than the upper yield stress; when the stress level was larger than 92% of the upper yield stress, the upper yield point disappeared.     

The salience network is activated during self‐recognition from both first‐person and third‐person perspectives

We usually observe ourselves from two perspectives. One is the first‐person perspective, which we perceive directly with our own eyes, and the other is the third‐person perspective, which we observe ourselves in a mirror or a picture. However, whether the self‐recognition associated with these two perspectives has a common or separate neural basis remains unclear. To address this, we used functional magnetic resonance imaging to examine brain activity while participants viewed pretaped video clips of themselves and others engaged in meal preparation taken from first‐person and third‐person perspectives. We found that the first‐person behavioral videos of the participants and others induced greater activation in the premotor‐intraparietal region. In contrast, the third‐person behavioral videos induced greater activation in the default mode network compared with the first‐person videos. Regardless of the perspective, the videos of the participants induced greater activation in the salience network than the videos of others. On the other hand, the videos of others induced greater activation in the precuneus and lingual gyrus than the videos of the participants. These results suggest that the salience network is commonly involved in self‐recognition from both perspectives, even though the brain regions involved in action observation for the two perspectives are distinct.     

A subcortical magnocellular pathway is responsible for the fast processing of topological properties of objects: A transcranial magnetic stimulation study

Rapid object recognition has survival significance. The extraction of topological properties (TP) is proposed as the starting point of object perception. Behavioral evidence shows that TP processing takes precedence over other geometric properties and can accelerate object recognition. However, the mechanism of the fast TP processing remains unclear. The magnocellular (M) pathway is well known as a fast route to convey “coarse” information, compared with the slow parvocellular (P) pathway. Here, we hypothesize that the fast processing of TP occurs in a subcortical M pathway. We applied single‐pulse transcranial magnetic stimulation (TMS) over the primary visual cortex to temporarily disrupt cortical processing. Besides, stimuli were designed to preferentially engage M or P pathways (M‐ or P‐biased conditions). We found that, when TMS disrupted cortical function at the early stages of stimulus processing, non‐TP shape discrimination was strongly impaired in both M‐ and P‐biased conditions, whereas TP discrimination was not affected in the M‐biased condition, suggesting that early M processing of TP is independent of the visual cortex, but probably occurs in a subcortical M pathway. Using an unconscious priming paradigm, we further found that early M processing of TP can accelerate object recognition by speeding up the processing of other properties, e.g., orientation. Our findings suggest that the human visual system achieves efficient object recognition by rapidly processing TP in the subcortical M pathway.     

肝、肺并发上皮样血管内皮瘤2例报告

目的探讨肝、肺并发上皮样血管内皮瘤的临床特点,提高对其认识。方法报告2例肝肺并发上皮样血管内皮瘤病例,结合相关文献分析该病的临床特点。结果EHE是一种少见的低度恶性血管性肿瘤,肝肺并发者极为罕见,且易误诊为转移瘤。结论肝肺并发EHE临床表现无特异性,肝脏EHE影像学有一定的特征性,病理仍然是确诊EHE的唯一手段。     

先验约束水平集方法提取乳腺超声病灶

超声图像自动分割技术具有重要的应用价值,同时面临很大挑战。本文针对乳腺超声图像局部分割需求。通过区域生长法自动快速提取初始分割区域作为水平集的初始条件,实现先验区域约束的作用,显著提高分割准确度;基于CV模型进行全局信息和区域信息的拟合,提高了弱边界的定位准确度;增加速度能量项,使零水平集更快地收敛在边界处;对经典水平集模型的一些能量项进行删减调整,以降低计算复杂度。分割实验结果表明,本文方法能够较为准确快速地实现病灶分割,有一定的临床辅助价值。     

扶桑花抗生育成分对早孕小鼠黄体影响的定量研究

本文处用图像分析仪 ,以核浆比和数密度为指标 ,研究了不同浓度的扶桑花提取物—HR 1对早孕小鼠黄本组织学的影响。结果表明 :(1)小鼠黄体细胞的核浆比和数密度 ,随给药剂量 (0、 4、 10、 10 0、10 0 0mg/kg/d)的增加而增加 ,其中 10 0和 10 0 0mg/kg/d两组的黄体细胞核浆比和数密度明显高于对照组(p <0 .0 5) ;(2 )黄体组织学的定性观察显示 ,给药各组的黄体细胞明显退化 ,细胞缩小 ,细胞界限不清。这些结果提示 ,扶桑花提取物的抗早孕作用与妊娠黄体受损有关。     

女性盆腔的MRI三维重建

目的:三维重建女性盆腔内器官和盆壁的复杂几何结构,为临床对女性盆腔内器官疾病的诊断和治疗提供解剖学依据.方法:选取一系列层厚为0.8 mm磁共振成像(MRI)的图像,运用三维图像重建软件MIMICS进行图像重建,建立其三维几何结构.结果:获得了闭孔内肌、肛提肌、膀胱、尿道、阴道、直肠等的独立三维几何结构,从解剖结构上完全还原其相对位置.结论:所获得的三维模型真实地反映了其解剖构型和几何外形,为临床诊断和治疗女性盆腔内器官的病变提供了解剖学依据,对教学亦有一定实用意义.