Krinke G J, Vidotto N, Weber E
Toxicology Department, Novartis Crop Protection AG, Stein, Switzerland.
Toxicol Pathol. 2000 Jan-Feb;28(1):113-21. doi: 10.1177/019262330002800114.
Teased-fiber technique is the best approach for studying peripheral myelinated nerve fibers in their continuity. It enables the assessment of size of myelin segments formed by Schwann cells and characterization of pathologic changes affecting the internodia, the paranodal regions, and the invested axons. Fiber teasing is performed on prestained proximodistally oriented portions of peripheral nerves. Specimens about 10 mm long are stained for 24-48 hours in Sudan black and then transferred to glycerin, where, using a pair of fine forceps and a stereomicroscope, they are separated into smaller fiber bundles from which single fibers are isolated. The work is performed on a glass slide with an adhesive surface (albuminized or "superfrost"), on which the fibers are placed in strict proximodistal orientation. Following drying in an oven, the slides are mounted with glycerin-gelatine (same as used for frozen sections). The changes, when present, can usually be recognized during the preparation, but fibers are reexamined and changes confirmed in mounted slides. Photographic reconstruction of the fibers facilitates their assessment and enables the documentation of findings. The teased-fiber technique is auxiliary to histopathology, and to limit the workload and save costs, it can be performed on only a few specimens selected for better characterization of changes recognized or suspected in tissue sections. In particular, segmental demyelination and early stages of Wallerian or secondary axonal degeneration can be recognized in teased fibers. Segmental demyelination is characterized by loss of fully myelinated segments and their replacement by newly formed short and thin segments, remyelinating the preserved axon. The early stage of secondary axonal degeneration is recognized by formation of ovoidal fiber fragments in the midinternodal region.
teased-fiber技术是研究外周有髓神经纤维连续性的最佳方法。它能够评估施万细胞形成的髓鞘节段大小，并对影响结间区、结旁区和被包裹轴突的病理变化进行特征描述。纤维分离是在外周神经预先染色的近远侧定向部分上进行的。将约10毫米长的标本在苏丹黑中染色24至48小时，然后转移至甘油中，在那里，使用一对精细镊子和体视显微镜，将它们分离成较小的纤维束，从中分离出单根纤维。这项工作在具有粘性表面（白蛋白化或“超低温冻存”）的载玻片上进行，纤维以严格的近远侧方向放置在其上。在烤箱中干燥后，将载玻片用甘油明胶（与用于冷冻切片的相同）封固。如有变化，通常在制备过程中即可识别，但纤维需重新检查并在封固后的载玻片上确认变化。纤维的摄影重建有助于对其进行评估，并能记录研究结果。 teased-fiber技术是组织病理学的辅助手段，为限制工作量和节省成本，仅对少数选定的标本进行该技术操作，以更好地表征在组织切片中识别或怀疑的变化。特别是，节段性脱髓鞘以及华勒氏变性或继发性轴索变性的早期阶段可在分离的纤维中识别出来。节段性脱髓鞘的特征是完全髓鞘化节段的丧失，并被新形成的短而细的节段取代，这些节段对保留的轴突进行再髓鞘化。继发性轴索变性的早期阶段通过结间区中部卵圆形纤维片段的形成来识别。
