组织工程化神经导管修复外周神经损伤

背景：神经导管技术理论上采用生物或非生物材料预制成合适的管状支架,桥接神经断端两侧,在提供神经再生微环境的同时通过神经诱导、营养作用促进神经再生。 目的：观察组织工程化神经导管修复外周神经损伤的临床效果。 方法：选择24例陈旧性上肢神经损伤患者,以患者自愿原则分2组治疗：试验组采用组织工程化神经导管修复,对照组采用自体周围体表感觉神经移植修复。治疗后随访6个月观察患者肢体神经损伤功能修复效果。 结果与结论：随访6个月后,两组肢体远端感觉运动功能与目测类比疼痛评分均较治疗前改善(P < 0.05),且试验组效果更好(P < 0.05);两组损伤侧感觉与运动神经传导速度均较治疗前改善(P < 0.05),且两组间差异无显著性意义。说明组织工程化神经导管材料符合神经修复导管支架的要求,临床应用疗效肯定。     

Malignant nerve sheath tumor of acoustic nerve

A malignant nerve sheath tumor of the acoustic nerve was found in a 54-year-old man whose right acoustic nerve signs had shown gradual worsening during the previous five years. No stigmata of von Recklinghausen's disease were noted. The tumor at autopsy extensively involved the brain stem, cerebellar hemisphere, tentorium of cerebellum, and cerebral occipitotemporal lobe on the right side. Histologically, the tumor was characterized by extreme hypercellularity, pleomorphism, and high mitotic activity. Ultrastructurally, there was an external lamina around the interdigitated cytoplasm of the tumor cells. Long-spacing collagens and junctional devices were also noted. This case is, to our knowledge, the first reported of a malignant nerve sheath tumor in the acoustic nerve.     

Peripheral nerve regeneration using acellular nerve grafts

Long gap peripheral nerve injuries usually require a graft to facilitate axonal regeneration into the distal nerve stump. The use of autografts is often limited because of graft availability and donor-site morbidity. We investigated whether acellular nerve allografts would provide an appropriate channel for the promotion and induction of sciatic nerve regeneration in rats. Axons sprouted from the proximal portion and reached the distal portion in the 1 cm-long grafts by 1 month. The number of axons in the regenerated nerves was similar to that of normal nerves at 1 month. Loading the grafts with betaNGF and VEGF increased the number and mean diameter of axons and neovascularization in the regenerated nerves at 1 month. The motor conduction velocity increased over time and reached 63 +/- 10% of that of normal nerves at 6 months. The nerve injuries treated with the acellular grafts had a significant improvement in motor, nociception, and proprioception function compared to untreated nerves. The results from this study suggest that acellular nerve allografts may be a useful biomaterial for functional peripheral nerve regeneration.     

单环刺缢及同种异体神经制成人工神经修复神经缺损

目的:研究去细胞的单环刺缢体壁和同种异体神经所构成的人工组织神经的组织相容性及其修复神经缺损的效果。方法:取大鼠40只随机分成实验组、自体神经组、硅胶管组、正常组。实验组将去细胞的单环刺缢体壁缝合成神经导管,其内充填去细胞的异体神经,修复大鼠10 mm坐骨神经缺损。术后4月,通过大体观察,组织形态学观察,了解该人工组织神经修复大鼠坐骨神经缺损的疗效。结果:该人工组织神经组织相容性良好,神经功能恢复效果正常组>自体神经组>实验组>硅胶管组,实验组疗效与自体神经组接近,明显优于硅胶管组。结论:将去细胞的单环刺缢体壁和同种异体神经制成人工组织神经修复周围神经缺损是可行的。     

合成材料神经导管与自体神经移植修复周围神经缺损的比较

背景：生物可降解材料制成的神经导管可在体内降解,避免出现的神经卡压等问题,因而受到越来越多的关注。 目的：比较自体神经移植与3种合成可生物降解材料神经导管在修复周围神经损伤的效果差异。 方法：通过电生理学检测,形态学观察等神经恢复效果评价方法,对比分析近年来常用的胶原神经导管、DL-乳酸-ε-己内酯神经导管、聚乙醇酸神经导管与自体神经移植修复周围神经缺损的效果。 结果与结论：虽然神经导管与自体神经移植相比在理论上有其优势的一面,但不同合成材料的神经导管之间在神经功能恢复中存在明显差异性,DL-乳酸-ε-己内酯神经导管修复效果与自体神经移植无明显差异,是较为理想的神经导管材料,聚乙醇酸神经导管因自身的因素影响其降解性能,在3种神经导管中的修复周围神经损伤效果最差,胶原神经导管需要交联剂改善其机械性能,其修复周围神经损伤效果居于前两者之间,因此,这3种神经导管在神经功能再生方面还有潜在的缺陷,不能完全替代自体神经移植,而且3者之间的性价比,还缺少足够的大样本长期随机对照实验结果来验证,还需要进一步的实验观察。     

Sural nerve defects after nerve biopsy or nerve transfer as a sensory regeneration model for peripheral nerve conduit implantation

Nerve repair after injury can be effectively accomplished by direct suture approximation of the proximal and distal segments. This is more successful if coadaptation can be achieved without tension. Currently, the gold standard repair of larger deficits is the transplantation of an autologous sensory sural nerve graft. However, a significant disadvantage of this technique is the inevitable donor morbidity (sensory loss, neuroma and scar formation) after harvesting of the sural nerve. Moreover, limitation of autologous donor nerve length and fixed diameter of the available sural nerve are major drawbacks of current autograft treatment. Another approach that was introduced for nerve repair is the implantation of alloplastic nerve tubes made of, for example, poly-l-lactide. In these, nerve stumps of the transected nerves are surgically bridged using the biosynthetic conduit. A number of experimental studies, primarily in rodents, indicate axonal regeneration and remyelination after implantation of various conduits. However, only limited clinical studies with conduit implantation have been performed in acute peripheral nerve injuries particularly on digital nerves. Clinical transfer of animal studies, which can be carefully calibrated for site and extent of injury, to humans is difficult to interpret due to the intrinsic variability in human nerve injuries. This prevents effective quantification of improvement and induces bias in the study. Therefore, standardization of lesion/repair in human studies is warranted.     

组织工程化神经修复周围神经创伤的应用

背景：近年来,随着生物工程技术以及组织工程化神经的发展给周围神经缺损的治疗带来了新的希望,已逐渐成为研究的焦点。 目的：从种子细胞、生物材料以及构建周围神经组织技术3个方面综述组织工程方法修复周围神经损伤的新进展。 方法：由第一作者在2013年7月应用计算机检索PubMed 数据库及CNKI 数据库,英文关键词为“tissue engineering,peripheral nerves,nerve injuries,stem cells,schwann cells,scaffold,growth factor”,中文关键词为“组织工程,周围神经,神经损伤,干细胞,许旺细胞,支架,生长因子”。选择内容与神经组织工程、周围神经损伤修复相关的文章,同一领域文献则选择近期发表或发表在权威杂志文章,共纳入63篇文献。 结果与结论：现阶段组织工程方法修复周围神经损伤的研究虽已取得很大进展,但大多停留于实验探索阶段。将组织工程神经应用于临床尚存下列问题亟待解决：①种子细胞来源及伦理。②细胞扩增后移植的免疫排斥。③移植细胞稳定性问题及致瘤性。④神经支架材料的降解速度、最佳孔隙率、导管厚度、形状等。⑤体外神经构建后移植修复时机。⑥各种神经生物因子的局部释放与调控等等。随着科技的发展,期待上述问题的解决,从而使得众多临床神经损伤患者受益。     

Electrical fields, nerve growth and nerve regeneration

The presence of voltage gradients within developing and damaged tissues led to the notion that the resultant electrical fields provide instructional cues to cells. Field effects on avian and amphibian neurones in vitro include increased differentiation, turning of neurites towards the cathode, increased rate of growth towards the cathode, resorption of anodefacing neurites, increased branching and increased filopodial activity. Electric fields enhance regeneration of damaged PNS and CNS neurones in animals as diverse as lampreys, frogs, rats and guinea-pigs, but the mechanisms by which fields produce their effects are not understood. Further examination of the interaction of fields with intracellular elements, such as the cytoskeleton and second messenger systems, may offer some insight.     

Mapping sensory nerve communications between peripheral nerve territories

The human cutaneous sensory map has been a work in progress over the past century, depicting sensory territories supplied by both the spinal and cranial nerves. Two critical discoveries, which shaped our understanding of cutaneous innervation, were sensory dermatome overlap between contiguous spinal levels and axial lines across areas where no sensory overlap exists. These concepts define current dermatome maps. We wondered whether the overlap between contiguous sensory territories was even tighter: if neural communications were present in the peripheral nerve territories consistently connecting contiguous spinal levels? A literature search using peer‐reviewed articles and established anatomy texts was performed aimed at identifying the presence of communications between sensory nerves in peripheral nerve territories and their relationship to areas of adjacent and non‐adjacent spinal or cranial nerves and axial lines (lines of discontinuity) in the upper and lower limbs, trunk and perineum, and head and neck regions. Our findings demonstrate the consistent presence of sensory nerve communications between peripheral nerve territories derived from spinal nerves within areas of axial lines in the upper and lower limbs, trunk and perineum, and head and neck. We did not find examples of communications crossing axial lines in the limbs or lines of discontinuity in the face, but did find examples crossing axial lines in the trunk and perineum. Sensory nerve communications are common. They unify concepts of cutaneous innervation territories and their boundaries, and refine our understanding of the sensory map of the human skin. Clin. Anat. 27:681–690, 2014. © 2013 Wiley Periodicals, Inc.     

Unmyelinated nerve fibers of the human mandibular nerve

The aim of this research is to find and to evaluate morphometorically the unmyelinated nerve fibers in the human mandibular nerve using a light microscope. Our report demonstrates for the first time the presence of the unmyelinated nerve fibers of the human mandibular nerve stained by a special method. Our results also indicate that there is a morphometric change with aging in the unmyelinated axons of the nerve.     

神经导管生物材料在神经修复中的应用

背景：神经导管是由天然或人工合成材料制成的、用于桥接神经断端的组织工程支架材料,具有引导和促进神经再生作用。 目的：总结近年来常用的神经导管生物材料在神经修复中的应用。 方法：由作者应用计算机检索维普数据库中与神经导管生物材料在神经修复中应用有关的文章,检索时限2002-01/ 2010-12。检索关键词：神经导管;生物材料;神经损伤;神经修复;神经再生。纳入标准：与神经导管生物材料在神经修复中应用有关的文章。排除标准：重复研究或较陈旧文献。根据纳入排除标准共保留相关文献30篇。 结果与结论：非生物降解材料由于其不可吸收性和对再生神经的远期不良影响使临床应用受到限制。生物降解材料在神经再生完成后可在体内降解吸收,无需二次手术取出,但目前未能利用生物降解材料完全仿制出具有天然神经结构的支架。生物衍生材料生物相容性好、排异反应小,可提供细胞外基质、胶原,起支架作用,但缺血后存在管形塌陷、再生不良、吸收瘢痕组织、增生及粘连等问题。神经导管生物材料在神经修复中的应用前景广阔,但单用一类材料难以制作出理想的神经导管生物材料,通过结合各类材料的优点,与神经营养因子、细胞外基质成分和许旺细胞等联合应用,制备新型具有生物活性的导管材料,将有利于神经修复进一步发展。     

A thirteenth cranial nerve: the cloacal nerve

The completion by vertebrates of micturition, defecation, and copulation via the cloaca or its derivatives is hypothesized to be best explained by the existence of a thirteenth cranial nerve, the cloacal nerve, which, similar to the facial and trigeminal nerves, functions as a mixed cranial nerve containing both general and special components.     

Formation and distribution of the sural nerve based on nerve fascicle and nerve fiber analyses

The formation and distribution of the sural nerve are presented on the basis of an investigation of 31 legs of Japanese cadavers using nerve fascicle and fiber analyses. Nerve fibers constituting the medial sural cutaneous nerve were designated as 'T', whereas those constituting the peroneal communicating branch were designated as 'F'. In 74.2% of cases (23/31), the T and F fibers joined each other in the leg, whereas in 9.7% of cases (3/31) they descended separately. In 16.1% of cases (5/31), the sural nerve was formed of only the T fibers. The sural nerve gave off lateral calcaneal branches and medial and lateral branches at the ankle. The lateral calcaneal branches always contained T fibers. The medial branches consisted of only T fibers, whereas most of the lateral branches consisted of only F fibers (71.0%; 22/31). In addition to the T and F fibers, P fibers, which derived from the superficial and deep peroneal nerves, formed the dorsal digital nerves. The P fibers were entirely supplied to the medial four and one-half toes. However, they were gradually replaced by the T and F fibers in the lateral direction. The 10th proper dorsal digital nerve consisted of T fibers only (38.7%; 12/31), of F fibers only (19.4%; 6/31) or of both T and F fibers (38.7%; 12/31). These findings suggest that the T fibers are essential nerve components for the skin and deep structures of the ankle and heel rather than the skin of the lateral side of the fifth toe. The designation of the medial sural cutaneous nerve should be avoided and only the T fibers are appropriate components for naming as the sural nerve.     

肌皮神经并正中神经及尺神经变异1例

在解剖一具老年男性标本时，见左侧肌皮神经并正中神经及尺神经形态变异(附图)。经查有关文献，此类变异较为少见，现报道如下：     

正常国人正中神经、尺神经、腓神经及腓肠神经刺激阈值的检测研究

目的：研究正常健康国人双侧正中神经、尺神经、腓神经及腓肠神经等四大周围神经刺激阈值正常值,为应用神经阈值诊断周围神经病变提供合理的数据。方法：健康志愿者20名中,男12名,女8名,分别检测双侧正中神经、尺神经、腓神经远端运动神经刺激阈值和腓肠感觉神经刺激阈值,对结果进行统计学分析。结果：上肢双侧正中神经、尺神经运动神经刺激阈值明显低于下肢腓神经运动神经刺激阈值。所测双侧正中神经、尺神经、腓神经和腓肠神经刺激阈值：左右两侧间差异无统计学意义,P值分别为0．39、0．11、0．07和0．51;男女性别间差异无统计学意义,P值分别为0．90、0．80、0．93、0．22、0．57、0．27、0．34和0．71;不同身高组间左右侧的差异也无统计学意义,P值分别为0．49、0．27、0．66、0．61、0．49、0．34、0．18、0．20。结论：上肢运动神经刺激阈值低于下肢,个体同名神经阈值左右侧间、不同性别者间、不同身高者间差异比较均无统计学意义;正常国人神经刺激阈值正常值范围可为周围神经病变的诊断提供参考依据。     

Unmyelinated nerve fiber analysis of the human oculomotor nerve

Unmyelinated nerve fibers of the oculomotor nerve have occasionally been observed in experimental animals with the use of electron microscopes, but no details concerning normal oculomotor nerves in humans have been published. We measured and analyzed unmyelinated nerve fibers in the human oculomotor nerve with an image analyzer and a computer, using a new staining method, the Luxol fast blue-periodic acid-Schiff-hematoxylin (LPH) discriminative staining method which is the only one suitable for morphometric research on nervous tissues. We studied the numbers and transverse areas of unmyelinated fibers of the oculomotor nerve in 20 cadavers. The number of unmyelinated axons did not change with age, but the mean transverse area decreased with age. These fibers were distributed diffusely in the transverse area of the oculomotor nerve, not localized in any part of the nerve. These findings may be important for the analysis of clinical and neurological signs in relation to aging and ophthalmologic functions.     

Evaluation of collagen nerve guide in facial nerve regeneration

Facial nerve paralysis due to resection of tumors or as a consequence of trauma is a frequently observed complication. Thus, in the present study, we evaluated a collagen nerve guide in facial nerve regeneration across a 5-mm nerve gap. This biological tube was manufactured from 3% collagen, coated over a Teflon tube used only as a template and submitted to thermal dehydration at 105°C for 24h. The collagen tube was implanted at the dorsal ramous of the facial nerve of five adult cats over a gap of 5mm. The facial nerve of the contralateral side was kept intact and used as control. Electrophysiological study was performed from 3 weeks after surgery, and histological and horseradish peroxidase labeling examination was carried out 8 weeks after implantation. Electrophysiological study confirmed the recovery of electrical activity of the collagenimplanted regenerated nerve. Light-microscopic examination of collagen tube-implanted specimens revealed a well vascularized regenerated nerve, which under an electron microscope showed many myelinated axons surrounded by Schwann cells and unmyelinated axons. Horseradish peroxidase staining demonstrated labeling of facial motoneurons in the brainstem and facial nerve terminals in the neuromuscular junction, also confirming restoration of the whole facial nerve tract from the reinnervated muscles, passing through the regenerated site to the brainstem. The collagen tube was very efficient as a nerve guide over a 5mm facial nerve gap and shows great promise as a nerve conduit.     

Variation of the spinal nerve compositions of thoracodorsal nerve

Thoracodorsal nerve distributes to the latissimus dorsi muscle. The aim of this study was to investigate the anatomic variation of the spinal nerve compositions of thoracodorsal nerve and to confirm which spinal nerve is a main component in participating amount. The most frequent type was consisted of C7 and C8 in 60%. Next frequent type was C6, C7, and C8 in 25%. Third type was C6 and C7 in 10% and fourth type was C7 alone in 5%. The diameter of each spinal nerve comprising thoracodorsal nerve was 1.20 +/- 0.23 (mean +/- SD) mm at C7, 0.43 +/- 0.15 mm at C8, and 0.33 +/- 0.09 mm at C6. These results show that the C7 nerve was the main component of thoracodorsal nerve and the anatomic variation appeared at the spinal nerve that participate by small amounts, as be excepted (C6 and C8).