黄韧带退变与腰椎管狭窄症椎管形态的变化

背景：目前研究发现Ⅰ型及Ⅱ型胶原在结缔组织的增殖与分化、软骨的形成和吸收等过程中起十分重要的作用。 目的：探讨腰椎黄韧带退变与腰椎管狭窄症椎管形态变化的相关性。 方法：收集中央型腰椎管狭窄症36例和外伤性腰椎骨折20例患者的黄韧带标本分别为实验组和对照组,采用酶联免疫吸附法测定Ⅰ型和Ⅱ型胶原;CT测量腰椎硬膜横截面积;黄韧带行苏木精-伊红和Masson染色,观察组织病理学变化。 结果与结论：实验组黄韧带厚度、Ⅰ型及Ⅱ型胶原含量高于对照组,腰椎硬膜横截面积和Ⅰ型/Ⅱ型比值低于对照组(P <　0.05);病理学显示实验组黄韧带弹性纤维排列紊乱,数量减少,胶原纤维增生。提示腰椎黄韧带Ⅰ型、Ⅱ型胶原含量及Ⅰ型/Ⅱ型比值发生改变,可能引起黄韧带厚度增加,导致椎管横截面积减小,参与腰椎管狭窄症的发生。关键词：黄韧带;腰椎管狭窄症;Ⅰ型胶原;Ⅱ型胶原;病理学 型/II型比值 doi:10.3969/j.issn.1673-8225.2012.17.001     

Regional difference in the appearance of apoptotic cell death in the ligamentum flavum of the human cervical spine

Ossification or calcification of the ligamentum flavum (LF) is relatively common in the middle and lower cervical, thoracic, and lumbar spine but extremely rare in the upper cervical region. This clinical fact suggests that there exist local factors promoting or preventing ossification or calcification of LF. However, little is known about the differences in the ultrastructure and cellular alterations of the LF between the different spinal levels, even in the cervical spine. With electron microscopy, we examined samples of LF collected surgically from the upper and lower cervical spine regions; we then studied the apoptotic appearance of ligament cells using a preferential labeling method. We found direct evidence of apoptosis of ligament cells in the LF. Apoptosis was more apparent in the upper region samples than in the lower region samples. The spaces around the normal fibroblasts were filled with thick collagen fibrils, but the collagen fibrils disappeared around the apoptotic bodies and thin fibrils were formed. The difference of the level of apoptosis may correlate to the ultrastructual difference of LF, and our data will benefit further investigations seeking to clarify the mechanism of various pathological conditions in the human LF.     

Spinal balance failure: a potential cause of spinal ligament ossification

Ossification of the posterior longitudinal ligament (OPLL) and of the ligamentum flavum (OLF), as well as calcification of ligamentum nuchae in the cervical spine and ossification of ligamentum flavum in the thoracic spine, are common types of spinal ligament ossification. As is known, the pathogenesis of OPLL and OLF has been unclear until recently, and mechanical stress assumably plays an important role. In this paper, we try to make a hypothesis that spinal balance failure (characterized by the gravity line, spinal curvature and flexion/extension in the sagittal plane), may play more important roles than any other factors in the development of ligament ossified diseases. Moreover, different stress thresholds and flexion/extension frequency may induce various ossification regions. It is supported by the conclusions that drawn from literature review: (1) OPLL and OLF seldom occur in lumbar spine which is of stiffer and lower-frequency motion than cervical spine, although its range of motion (ROM) was relatively great. (2) Spinal ligament ossification often appears in the cervical spine, which is significantly flexible with a larger motion range. (3) OLF is often seen in the thoracic spine, which is farthest away from the gravity line for thoracic kyphosis. (4) Many OPLL or OLF patients are often found with a local kyphosis or high segmental ROM. (5) The prevalence of ossification is higher in the larger stress regions, as described above, indicating that there may be a stress threshold for the spinal ligaments.     

腰椎黄韧带肥厚骨化的数字化表现

目的　通过对腰椎退变黄韧带的数字化重建,为影像诊断和临床手术规划,提供立体直观的形态学依据。 方法　收集腰腿痛患者薄层螺旋CT影像资料,在后处理工作站中观察退变黄韧带形态及分布,选取轴位像中黄韧带厚度大于4 mm和/或有钙化患者63例,男31例,女32例,年龄32~80岁。将原始数据导入Mimics16.0软件重建图像,观察其形态、分布。 结果　315个腰椎节段中205个节段出现黄韧带肥厚和/或骨化。黄韧带单纯肥厚占总出现节段79.51%,单纯骨化占6.34%,肥厚伴骨化占14.15%。205个节段全部成功建模,肥厚黄韧带建模形态有合页状、不规则片状和柱状;骨化黄韧带建模形态有短柱状、短锥状、不规则片状;肥厚伴骨化黄韧带重建后形态各异。 结论　数字化技术重建黄韧带能清楚显示其分布、形态、邻近结构,还可将所建退变黄韧带模型与腰椎骨性模型随意组合、切割,便于立体直观地显示病变细节。     

骨桥蛋白及其受体在黄韧带骨化症黄韧带细胞中的表达及其意义

BACKGROUND: The exact pathogenesis of ossification of ligamentum flavum has not been elucidated yet. And osteopontin may be an important factor involved in the ossification of ligamentum flavum. OBJECTIVE: To clarify the expression and significance of osteopontin and its receptors, CD44 and integrin-β3, in ligamentum flavum cells between normal controls and patients with ossification of ligamentum flavum.   METHODS: Ligamentum flavum tissues were obtained from normal adult controls and adult patients with ossification of ligamentum flavum (n=8 per group) who underwent thoracic/lumbar posterior decompression surgery. Ligmentum flavum cells were separated, cultured and identified in vitro, and osteopontin, CD44, integrin-β3 were stained using immunocytochemistry method and observed under inverted phase contrast microscope. And the mRNA expressions of osteopontin, CD44, integrin-β3 were measured by RT-PCR. RESULTS AND CONCLUSION: Immunocytochemistry results showed that the stronger positive staining for osteopontin, CD44, integrin-β3 was observed in the ossification of ligamentum flavum group than the control group (P < 0.01). The mRNA expressions of osteopontin, CD44 and integrin-β3 were also higher in the ossification of ligamentum flavum group than the control group (P < 0.05). These findings indicate that osteopontin and its receptors, CD44 and integrin-β3, in ligamentum flavum cells may play an important role in ossification of ligamentum flavum.      

腰椎肥厚黄韧带中细胞凋亡及凋亡因子caspase-3、fas、p53的表达

文题释义： 黄韧带：由左右两部分组成,韧带上下分别附着于上位椎板的前下方,下位椎板的上缘,连接椎弓板,参与围成椎管,控制脊柱过度前屈,维持脊柱稳定。黄韧带肥厚可造成椎管管腔减小及椎间孔狭窄,硬膜囊和脊神经根的压迫,从而产生临床症状。 免疫组织化学技术：是用标记的特异性抗体(或抗原)对组织内的抗原(或抗体)的分布进行定位、定性、定量检测,经过组织化学呈色反应在组织原位显示抗原(或抗体),如各种蛋白质、多肽、磷脂和多糖等成分的一门技术。 背景：腰椎管狭窄症是造成老年人步态紊乱和腰腿痛的关键原因之一,黄韧带肥厚是导致腰椎管狭窄症的主要病理机制,目前关于黄韧带的影像学及病理研究较多,关于细胞凋亡的研究较少。                                                   目的：检测肥厚黄韧带组织中的细胞凋亡率及凋亡因子caspase-3、fas、p53的表达,为深入了解黄韧带退变的机制提供实验依据。          方法：实验组50个经MRI及术后测量证实肥厚黄韧带标本(L₂-S₁)来自50例腰椎管狭窄症行后路减压手术自愿捐赠的患者,男22例,女28例,年龄32-74岁,平均54.46岁;对照组30个经MRI及术后测量证实非肥厚黄韧带标本(L₂-S₁)来自30例腰椎间盘突出症行手术及腰椎爆裂骨折行手术患者,男19例,女11例,年龄19-67岁,平均47.27岁。采用TUNEL染色法检测黄韧带中的凋亡细胞率,用SP免疫组织化学法检测caspase-3、fas、p53的表达。研究通过了新疆医科大学第六附属医院伦理委员会批准,伦理编号为LFYLLSJ2016007。                                           结果与结论：①TUNEL染色示实验组的平均凋亡细胞率高于对照组[(37.80±3.04)%,(13.18±1.34)%,t=41.83,P < 0.001];②SP免疫组织化学染色示实验组caspase-3、fas、p53阳性表达率均为100%,对照组caspase-3、fas、p53阳性表达率为13.3%,16.7%,10%,两组比较差异均有统计学意义(P < 0.001)。结果表明,腰椎肥厚黄韧带组织中细胞凋亡增加,肥厚黄韧带中细胞凋亡与caspase-3、fas、p53的表达上调具有一定的相关性。 ORCID: 0000-0002-0539-5510(张方新) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

The Lumbar Ligamentum Flavum Does Not Have Two Layers and Is Confluent with the Interspinous Ligament: Anatomical Study with Application to Surgical and Interventional Pain Procedures

Numerous authors over the years have reported that the lumbar ligamentum flavum has two layers. Our routine cadaveric dissections raised the question whether this understanding is correct, as we always have observed only one layer. Thus, the goal of this cadaveric study was to reevaluate the layers of the ligamentum flavum. Twenty lumbar levels from five fresh-frozen cadaveric specimens were used in this study. After dissection of the lumbar spine, the ligamentum flavum and interspinous ligament were exposed. Each lumbar level was transected through the zygapophyseal joint, and hematoxylin and eosin staining, Masson's trichrome staining and Verhoeff-van Gieson staining were performed. Continuation of the interspinous ligament and ligamentum flavum were observed invariably. There was no evidence of the existence of a two-layered ligamentum flavum. The lumbar ligamentum flavum does not consist of two layers, but is confluent instead with the interspinous ligament that attaches to the zygapophyseal joints. To convey this anatomy better, we suggest describing the lumbar ligamentum flavum as a structure that consists of interlaminar and interspinous parts. Precise knowledge of the ligamentum flavum's anatomy can be of clinical value, particularly when epidural anesthesia or lumbar puncture are performed. Clin. Anat. 32:34–40, 2019. © 2019 Wiley Periodicals, Inc.     

经椎板间隙内窥镜下分开黄韧带切除椎间盘

背景：经椎板间隙途径内窥镜下间盘切除需游离黄韧带,后者如果辅助连续扩张器及工作通道进行操作,无论切口多小(甚至3-5 mm),均可完整保留黄韧带。 目的：介绍经椎板间隙内窥镜下分开黄韧带切除椎间盘的应用。 方法：采用经椎板间隙内窥镜下分开黄韧带椎间盘切除治疗16 例男性患者和14例女性患者,平均年龄(48±15)岁,主诉单下肢根性疼痛,病变位于L_3-4间隙1例,L_4-5间隙13例,L₅-S₁间隙16例,其中间盘向上脱出游离者4例,向下脱出游离者7例,所有患者术中电生理监测,在工作通道中分开黄韧带,间盘切除撤出工作通道后,黄韧带可自行复位。 结果与结论：操作时间20-40 min,治疗后随访时间(149±108) d。治疗中电生理监测无异常,椎间盘切除症状均得以改善。经核磁随访显示：脱出间盘组织已完全摘除,黄韧带保留完整,所有患者无相关并发症。结果可见经椎板间隙内窥镜下分开黄韧带切除脱出的间盘组织,是一种可行的操作方式。     

Morphologic and histologic study of the ligamentum flavum in the thoraco-lumbar region

The ligamentum flavum, of which there are only a few studies in the literature, has several features discussed in this work. On the macroscopic level, it has a metameric arrangement it has two layers, superficial and deep, whose fibers are oppposite, and it has close relations with the tendons of attachment of some spinal erector muscles. On the microscopic level, its structure is unique for a ligament, because of a predominance of elastic fibers, because of its intrinsic innervation at each level of the spine, and because this innervation grows poorer with increasing degeneration. The ligamentum flavum constitutes an active ligament, with an essential biomechanical role. Its injury is probably not without consequences, and therefore there are many technical problems about the surgical interlaminar approach.     

人黄韧带细胞骨化发生过程中的自噬

文题释义： 黄韧带骨化症：是由于脊柱黄韧带发生骨向分化而形成的一种韧带骨化疾病,常导致椎管狭窄,造成脊髓受压,并产生不可逆损害,出现肢体感觉障碍,严重的将导致瘫痪。目前对黄韧带骨化病因学研究取得了一定的进展,但其具体的发病机制仍未完全明确。 自噬：因外界或自身环境的改变,细胞器和胞内蛋白通过溶酶体进行分解消化并重新利用,从而达到适应外界环境、维持细胞内环境稳定的过程,是真核细胞特有一种表现形式。 MAPK信号通路：是生物体内重要的信号转导系统之一,它可以被物理应激、炎性细胞因子、生长因子以及细胞复合物等一系列细胞外信号或刺激激活,从而参与介导细胞生长、发育、分裂以及分化等多种生理及病理过程。在哺乳动物细胞中MAPK信号通路的主要信号分子包括ERK1/2、JNK以及P38等。 背景：黄韧带骨化发生的病理机制尚不清楚,临床上无有效的药物或非手术治疗的方法。目前研究发现,骨桥蛋白与自噬在成骨过程中均发挥重要作用,二者在黄韧带骨化中的作用尚不清楚。 目的：通过对骨桥蛋白和自噬在黄韧带骨化发生机制的研究,尝试找出药物治疗的潜在作用靶点。 方法：①黄韧带骨化病、胸椎骨折或单纯腰椎间盘突出症患者行后路全椎板切除减压获取黄韧带,将标本分为骨化组和非骨化组,每组各取8例标本,通过免疫组化染色观察骨桥蛋白、骨钙素及自噬指标Beclin-1、LC3、P62的表达;②通过组织块贴壁法进行黄韧带细胞的分离培养,并用不同质量浓度的骨桥蛋白干预不同时间来构建体外黄韧带细胞骨化模型;③非骨化组黄韧带细胞用不同浓度的自噬抑制剂3-甲基腺嘌呤干预后,再用100 μg/L骨桥蛋白诱导,应用Western blot检测骨化指标碱性磷酸酶、骨钙素的表达变化;④用100 μg/L骨桥蛋白干预非骨化黄韧带细胞,并在0,15,30,60,120 min终止骨化诱导过程,应用Western blot检测MAPK信号通路中重要分子ERK1/2、JNK、P38的磷酸化情况;⑤非骨化组黄韧带细胞用ERK1/2特异的磷酸化阻滞剂U0126阻断ERK1/2通路磷酸化后,再用100 μg/L骨桥蛋白诱导,应用Western blot检测碱性磷酸酶以及骨钙素的表达变化。 结果与结论：①骨化黄韧带和非骨化黄韧带组织骨钙素、骨桥蛋白的免疫组化均呈阳性表达;骨化黄韧带组织中Beclin-1呈阳性表达,而LC3及P62未见明显阳性结果;非黄韧带骨化组织中Beclin-1、LC3、P62均呈阳性表达;②与非骨化组比较,骨化组黄韧带细胞中碱性磷酸酶和骨钙素的表达增加;骨桥蛋白可诱导黄韧带骨化,骨桥蛋白的作用具有浓度相关性和时间相关性;③自噬强弱与骨化程度呈负相关,即自噬越明显,骨化作用越弱;④骨桥蛋白能使MAPK信号通路磷酸化,并具有一定的时间相关性;抑制MAPK磷酸化过程后,骨桥蛋白仍然能够诱导黄韧带细胞的骨化;⑤结果表明,黄韧带骨化发生过程中,信号通路上ERK1/2、骨桥蛋白、骨钙素、碱性磷酸酶分子的上下游关系为：ERK1/2→骨桥蛋白→骨钙素/碱性磷酸酶。 ORCID: 0000-0003-0008-9802(许国峰) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Spinal cord gray matter demyelination in multiple sclerosis-a novel pattern of residual plaque morphology

The extent and pattern of gray matter (GM) demyelination in the spinal cord in multiple sclerosis (MS) has not been examined in detail. Human autopsy material was obtained from 36 MS cases and 12 controls. Transverse sections were taken from five levels of the spinal cord (upper cervical, lower cervical, upper thoracic, lower thoracic and lumbar levels) and the extent of GM and white matter (WM) demyelination evaluated using proteolipid protein immunohistochemistry (IHC). The proportion of the GM that was demyelinated (33%) was significantly greater than the proportion of demyelinated WM (20%) (P < 0.0001). Similarly, demyelination was more extensive in the GM than in the WM at each of the five cord levels. The extent of GM demyelination was not significantly different between the five cord levels while WM demyelination was greatest at the upper cervical level. Morphologically, the borders of a proportion of the GM plaques show a strict respect for the GM/WM boundary. We demonstrate that extensive demyelination occurs in the GM of the spinal cord in MS. Myelin protein IHC reveals a novel pattern of residual plaque morphology challenging previous work suggesting that MS plaques display a total disregard for anatomical boundaries.     

MRI T2WI量化指标评估胸椎黄韧带骨化症手术预后的价值

文题释义：胸椎黄韧带骨化症：是一种病理性的异位骨化,起病隐匿,其病因及发病机制仍不清楚,部分学者认为与遗传、代谢异常、生活环境及退变等因素相关。胸椎黄韧带骨化症是导致胸椎管狭窄的最常见、最重要原因,由于胸脊髓血供较脆弱,当椎管狭窄时可明显影响脊髓血液循环,造成脊髓功能障碍,主要症状表现为下肢的感觉运动障碍。 受试者工作特征(ROC)曲线：就是以假阳性概率为横轴,真阳性为纵轴所组成的坐标图,和受试者在特定刺激条件下由于采用不同的判断标准得出的不同结果画出的曲线。 背景：MRI对于胸脊髓病变具有较高的灵敏性,能够通过脊髓受压的形态及信号强度变化来评估脊髓受损情况,并且对胸椎管狭窄症患者手术预后有提示作用。 目的：分析MRI T2WI量化指标对胸椎黄韧带骨化症患者手术预后的评估价值,并建立预后不良的预测模型,为其预后评估提供参考。 方法：回顾性分析2010年1月至2019年1月沧州市中心医院87例行胸椎管后壁切除减压术且完成术后随访的胸椎黄韧带骨化症患者的临床与影像学资料。根据术后6个月随访时的JOA评分改善率将患者分为预后优良组(改善率≥50%)和预后不良组(改善率<50%)。比较两组患者年龄、性别、病程、JOA评分、骨化物Sato分型、脊髓矢状径残余率、脊髓横截面积、脊髓高信号分布、脊髓信号强度比值、高信号范围、胸椎局部后凸角、后凸角矫正度数、减压节段数以及脑脊液漏变化。单因素分析有显著性差异的指标。采用受试者工作特征曲线(ROC)进行预后分析,纪录曲线下面积及预测界值。多因素Logistic回归分析确定预后不良的独立危险因素,并建立预测模型。 结果与结论：①预后优良组与预后不良组患者病程、JOA评分、脊髓矢状径残余率、脊髓横截面积、脊髓信号强度比值、高信号范围比较差异有显著性意义(P < 0.05);②ROC曲线分析显示,上述各指标预测手术预后不良的曲线下面积分别为0.670,0.733,0.647,0.715,0.753和0.765,预测界值分别为13个月、4 分、29.8%、0.25 cm²、1.593和13.64 mm。病程与脊髓矢状径残余率预测价值较低(ROC曲线下面积 < 0.7);JOA评分、脊髓横截面积、脊髓信号强度比值与高信号范围具有中等预测价值(ROC曲线下面积 0.7-0.9)。脊髓信号强度比值联合高信号范围预测预后不良的ROC曲线下面积为0.791。③多因素Logistic回归分析显示：JOA评分、脊髓横截面积、脊髓信号强度比值联合高信号范围为预后不良的独立危险因素(P < 0.05),并据此建立预测模型,该模型预测预后不良的曲线下面积为0.890,显著高于JOA评分、脊髓横截面积、脊髓信号强度比值联合高信号范围预测的曲线下面积(P < 0.05)。④结果证实,对胸椎黄韧带骨化症患者而言,在MRI量化指标中,脊髓信号强度比值联合高信号范围具有最高的手术预测价值,JOA评分与MRI T2WI量化指标相结合,可更好地预测术后风险。 ORCID: 0000-0003-3354-1228(申沧海) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Central projections of spinal dorsal roots in the monkey. II. Lower thoracic,lumbosacral and coccygeal dorsal roots

A study of the central distribution of lower thoracic, lumbosacral and coccygeal dorsal roots (DR) was made in 11 monkeys. Degeneration resulting from 17 individual dorsal rhizotomies was studied in multiple spinal and medullary sections stained by the Nauta technic. At the rhizotomy level all DR project fibers to: (1) portions of laminae III and IV, (2) the intermediomedial nucleus, and (3) portions of laminae VII, VIII and IX. Lower thoracic, lumbar and the first sacral (S1) DR project in overlapping fashion to particular portions of Clarke's column; ascending and descending fibers terminate in a spatially organized manner. Lower lumbar DR project to medial lamina VI throughout the lumbar enlargement. DR fibers reach cell groups of lamina IX via two trajectories, one of which is dominant in the lumbar enlargement. Ascending DR fibers in the fasciculus gracilis: (1) arise caudal to T7, (2) exhibit only general segregation due to overlap, and (3) project in an overlapping somatotopic fashion throughout the rostrocaudal extent of the nucleus gracilis. Zones of the nucleus gracilis receiving fibers are organized, so that: (1) DR of the lumbar enlargement project to a central core region, (2) lower thoracic and upper lumbar DR project to narrow oblique laminae lateral to the core, and (3) S1 and Co1 DR project to crescent-shaped dorsomedial regions. Less autonomous terminal representation of DR fibers was found in the nucleus gracilis than in other posterior column nuclei.     

The cat vertebral column: stance configuration and range of motion

This study examined the configuration of the vertebral column of the cat during independent stance and in various flexed positions. The range of motion in the sagittal plane is similar across most thoracic and lumbar joints, with the exception of a lesser range at the transition region from thoracic-type to lumbar-type vertebrae. The upper thoracic column exhibits most of its range in dorsiflexion and the lower thoracic and lumbar in ventroflexion. Lateral flexion is limited to less than 5° at all segments. The range in torsion is almost 180° and occurs primarily in the midthoracic region, T4-T11. Contrary to the depiction in most atlases, the standing cat exhibits several curvatures, including a mild dorsiflexion in the lower lumbar segments, a marked ventroflexion in the lower thoracic and upper lumbar segments, and a profound dorsiflexion in the upper thoracic (above T9) and cervical segments. The curvatures are not significantly changed by altering stance distance but are affected by head posture. During stance, the top of the scapula lies well above the spines of the thoracic vertebrae, and the glenohumeral joint is just below the bodies of vertebrae T3-T5. Using a simple static model of the vertebral column in the sagittal plane, it was estimated that the bending moment due to gravity is bimodal with a dorsiflexion moment in the lower thoracic and lumbar region and a ventroflexion moment in the upper thoracic and cervical region. Given the bending moments and the position of the scapula during stance, it is proposed that two groups of scapular muscles provide the major antigravity support for the head and anterior trunk. Levator scapulae and serratus ventralis form the lateral group, inserting on the lateral processes of cervical vertebrae and on the ribs. The major and minor rhomboids form the medial group, inserting on the spinous tips of vertebrae from C4 to T4. It is also proposed that the hypaxial muscles, psoas major, minor, and quadratus lumborum could support the lumbar trunk during stance. Received: 2 January 1997 / Accepted: 23 September 1997     

Anatomical studies on the ovine spinal cord

The root attachment lengths were consistently greater in the cranial cervical (C3), midthoracic (T7), caudal lumbar (L5) and cranial sacral (S1) cord segment levels than the corresponding caudal cervical, caudal thoracic, cranial lumbar and caudal sacral levels respectively. As to the root emergence length the greatest values were obtained bilaterally at C3, T1, L4 and S1 cord segment levels respectively. The interroot intervals were maximum at C3, T13, L1 and S1 cord levels in the respective regions. The longest cord segments were located at C2, T13, L3 and S1 levels; the shortest were at C8, T1, L6, and S4 cord levels. The greatest diameter and cross-sectional area were confined to the last cervical, first 2 thoracic, last lumbar and first sacral cord segment levels. The spinal cord segments C2, T13, L4 and S1 were most voluminous in the respective regions. The topography of cord segments and the level of termination of the spinal cord have been studied and recorded.     

An ultrastructural study on the ligamentum flavum of the cervical spine in patients with ossification of the posterior longitudinal ligament

Some histological analyses of the ossification of the posterior longitudinal ligament (OPLL) have been reported, but no ultrastructural studies of the ligamentum flavum (LF) in patients with OPLL have been published to date. To understand the pathology of the ossification of the spinal ligament, we examined, by electron microscopy, ultrastructural changes in the LF in cases of OPLL and made a comparison with the LF in cervical spondylotic myelopathy (CSM). Subjects were three men and two women with cervical OPLL who underwent longitudinal spinous process-splitting laminoplasty. During surgery, a small piece of the LF was collected from C2–C3 to C7–T1 and was then analyzed by light and electron microscopy. We observed atrophic elastic bundles with a two-layer structure and disarrangement, a partially torn area, the disappearance of microfibrils, and an enlarged interstitium with an irregular alignment of collagen fibrils. We observed some properties of a cell preceding its death: the initial phase may be the disappearance of the plasma-membrane, followed by the scattering of many organellae around its degenerated nucleus. Finally, many extracellular plasma membrane-invested particles that resemble matrix vesicles remain there without phagocytosis. These results suggest that ultrastructural abnormalities exist in the spinal ligament in cases of ossification of the spinal ligament.     

大白鼠脊髓向延髓外侧网状核投射的体部定位——HRP顺行法研究

向大白鼠脊髓的颈、腰膨大和胸髓右侧半分别注入HRP或WGA—HRP,研究了脊髓向延髓外侧网状核的投射。 1.双侧的三叉神经下亚核同时接受颈、胸和腰髓来的投射。 2.大白鼠脊髓主要投射于外侧网状核的尾侧半,有一定的体部定位关系。颈髓投射于双侧大细胞亚核的外侧2/3及与共相邻接的一部分小细胞亚核内,以同侧投射为主。胸髓投射于双侧的大细胞亚核的内侧2/3和与之相邻接的一部分小细胞亚核内,两侧无明显差別。腰髓投射于双侧小细胞亚核和与之相邻接的部分大细胞亚核内,以对侧投射为主。它们相互间有部分重叠。 3.颈、胸和腰髓内外侧网状核投射的神经元位于从背角至腹角的灰质内,越边投射的神经元比不越边投射的神经元位置更靠腹侧。     

Spinal Cord Neuronal Pathology in Multiple Sclerosis

The objective of this study was to assess neuronal pathology in the spinal cord in multiple sclerosis (MS), both within myelinated and demyelinated tissue. Autopsy material was obtained from 38 MS cases and 21 controls. Transverse sections were taken from three spinal cord levels and stained using Luxol Fast Blue/Cresyl Violet and myelin protein immunohistochemistry. Measurements of neuronal number and size were made for all neurons within the anterior horns of the gray matter. Neurons were classified as motoneurons or interneurons according to size criteria. In comparison with controls, both motoneuron and interneuron number were reduced in MS cases at the upper cervical (interneuron P  = 0.0549; motoneuron P  = 0.0073) and upper thoracic (interneuron P  = 0.0507; motoneuron P  = 0.0144), but not the lumbar level. Interneuron cross-sectional area was reduced in MS cases at all levels (upper cervical, P  = 0.0000; upper thoracic, P  = 0.0002; lumbar, P  = 0.0337). Neuronal loss appears to be predominantly related to local gray matter plaques, whereas interneuron atrophy occurs in both myelinated and demyelinated areas.     

Identification of cells of origin of long fiber connections in the cat's spinal cord by means of the retrograde axonal horseradish peroxidase technique

The location of the cells of origin of the propriospinal and long ascending spinal fibers has been determined by injecting horseradish peroxidase (HRP) unilaterally into the white and gray matter of the cat's spinal cord at cervical, thoracic and lumbar levels. In all cases retrogradely labeled neurons were present in the intermediate zone throughout the spinal cord. Caudal to the injections labeled neurons were also present in the dorsal horn, the column of Clarke and the area of the spinal border cells.     

Viscoelastic properties of the cervical spinal ligaments under fast strain-rate deformations

The mechanical response of ligaments under fast strain-rate deformations is a necessary input into computational models that are used for injury assessment. However, this information frequently is not available for the ligaments that are routinely injured in fast-rate loading scenarios. In the current study, experiments were conducted at fast strain rates for the cervical spinal ligaments: the anterior longitudinal ligament, the posterior longitudinal ligament and the ligamentum flavum. Bone-ligament-bone complexes at three spine levels were harvested for mechanical testing. Displacement-controlled sub-failure uniaxial tensile tests were performed in both load-relaxation and sinusoidal conditions. A nonlinear (separable) viscoelastic model was used to examine the experimental data. An unexpected result of the modeling was that the instantaneous elastic functions could be approximated as linear for these strain rates. A five-parameter model was sufficient to characterize the ligament viscoelastic responses and had good predictive capacity under different applied loading conditions.