Acrylamide exposure impairs blood-cerebrospinal fluid barrier function

Previous studies show that chronic acrylamide exposure leads to central and peripheral neu- ropathy. However, the underlying mechanisms remained unclear. In this study, we examined the permeability of the blood-cerebrospinal fluid barrier, and its ability to secrete transthyretin and transport leptin of rats exposed to acrylamide for 7, 14, 21 or 28 days. Transthyretin levels in cerebrospinal fluid began to decline on day 7 after acrylamide exposure. The sodium fluorescein level in cerebrospinal fluid was increased on day 14 after exposure. Evans blue concentration in cerebrospinal fluid was increased and the cerebrospinal fluid/serum leptin ratio was decreased on days 21 and 28 after exposure. In comparison, the cerebrospinal fluid/serum albumin ratio was increased on day 28 after exposure. Our findings show that acrylamide exposure damages the blood-cerebrospinal fluid barrier and impairs secretory and transport functions. These changes may underlie acrylamide-induced neurotoxicity.     

Increased expression of Notch1 in temporal lobe epilepsy: animal models and clinical evidence

Temporal lobe epilepsy is associated with astrogliosis. Notchl signaling can induce astrogliosis in glioma. However, it remains unknown whether Notchl signaling is involved in the pathogenesis of epilepsy. This study investigated the presence of Notchl, hairy and enhancer of split-l, and glial fibrillary acidic protein in the temporal neocortex and hippocampus of lithium-pilocar- pine-treated rats. The presence of Notchl and hairy and enhancer of split-1 was also explored in brain tissues of patients with intractable temporal lobe epilepsy. Quantitative electroencephalo- gram analysis and behavioral observations were used as auxiliary measures. Results revealed that the presence of Notchl, hairy and enhancer of split-l, and glial fibriUary acidic protein were en- hanced in status epilepticus and vehicle-treated spontaneous recurrent seizures rats, but remain unchanged in the following groups： control, absence of either status epilepticus or spontaneous recurrent seizures, and zileuton-treated spontaneous recurrent seizures. Compared with patient control cases, the presences of Notch1 and hairy and enhancer of split- 1 were upregulated in the temporal neocortex of patients with intractable temporal lobe epilepsy. Therefore, these results suggest that Notchl signaling may play an important role in the onset of temporal lobe epilepsy via astrogliosis. Furthermore, zileuton may be a potential therapeutic strategy for temporal lobe epilepsy by blocking Notchl signaling.     

The optimal distance between two electrode tips during recording of compound nerve action potentials in the rat median nerve简

The distance between the two electrode tips can greatly influence the parameters used for record- ing compound nerve action potentials. To investigate the optimal parameters for these recordings in the rat median nerve, we dissociated the nerve using different methods and compound nerve action potentials were orthodromically or antidromically recorded with different electrode spac- ings. Compound nerve action potentials could be consistently recorded using a method in which the middle part of the median nerve was intact, with both ends dissociated from the surrounding fascia and a ground wire inserted into the muscle close to the intact part. When the distance be- tween two stimulating electrode tips was increased, the threshold and supramaximal stimulating intensity of compound nerve action potentials were gradually decreased, but the amplitude was not changed significantly. When the distance between two recording electrode tips was increased, the amplitude was gradually increased, but the threshold and supramaximal stimulating intensity exhibited no significant change. Different distances between recording and stimulating sites did not produce significant effects on the aforementioned parameters. A distance of 5 mm between recording and stimulating electrodes and a distance of 10 mm between recording and stimulating sites were found to be optimal for compound nerve action potential recording in the rat median nerve. In addition, the orthodromic compound action potential, with a biphasic waveform that was more stable and displayed less interference （however also required a higher threshold and higher supramaximal stimulus）, was found to be superior to the antidromic compound action potential.     

Optimal duration of percutaneous microballoon compression for treatment of trigeminal nerve injury简

Percutaneous microballoon compression of the trigeminal ganglion is a brand new operative technique for the treatment of trigeminal neuralgia. However, it is unclear how the procedure mediates pain relief, and there are no standardized criteria, such as compression pressure, compression time or balloon shape, for the procedure. In this study, percutaneous microballoon compression was performed on the rabbit trigeminal ganglion at a mean inflation pressure of 1,005 ± 150 mmHg for 2 or 5 minutes. At 1, 7 and 14 days after percutaneous microballoon compression, the large-diameter myelinated nerves displayed axonal swelling, rupture and demyelination under the electron microscope. Fragmentation of myelin and formation of digestion chambers were more evident after 5 minutes of compression. Image analyzer results showed that the diameter of trigeminal ganglion cells remained unaltered after compression. These experimental findings indicate that a 2-minute period of compression can suppress pain transduction. Immunohistochemical staining revealed that vascular endothelial growth factor expression in the ganglion cells and axons was significantly increased 7 days after trigeminal ganglion compression, however, the changes were similar after 2-minute compression and 5-minute compression. The upregulated expression of vascular endothelial growth factor in the ganglion cells after percutaneous microballoon compression can promote the repair of the injured nerve. These findings suggest that long-term compression is ideal for patients with recurrent trigeminal neuralgia.     

Adipose derived stem cells and nerve regeneration

Injuries to peripheral nerves are common and cause life-changing problems for patients alongside high social and health care costs for society. Current clinical treatment of peripheral nerve injuries predominantly relies on sacrificing a section of nerve from elsewhere in the body to provide a graft at the injury site. Much work has been done to develop a bioengineered nerve graft, precluding sacrifice of a functional nerve. Stem cells are prime candidates as accelerators of regeneration in these nerve grafts. This review examines the potential of adipose-derived stem cells to improve nerve repair assisted by bioengineered nerve grafts.     

Strategies for myelin regeneration: lessons learned from development

Myelin regeneration is indispensably important for patients suffering from several central nervous system （CNS） disorders such as multiple sclerosis （MS） and spinal cord injury （SCI）, because it is not only essential for restoring neurophysiology, but also protects denuded axons for secondary degeneration. Understanding the cellular and molecular mechanisms underlying remyelination is critical for the development of remyelination-specific therapeutic approaches. As remyelination shares certain common mechanisms with developmental myelination, knowledge from study of developmental myelination contributes greatly to emerging myelin regeneration therapies, best evidenced as the recently developed human anti-Nogo receptor interacting protein-1 （LINGO-1） monoclonal antibodies to treat MS patients in clinical trials.     

The potential of endogenous neurogenesis for brain repair and regeneration following traumatic brain injury

Traumatic brain injury （TBI） is the leading cause of death and disability of persons under 45 years old in the United States, affecting over 1.5 million individtials each year. It had been th ought that recovery from such injuries is severely limited due to the inability of the adult bra in to replace damaged neurons. However, recent studies indicate that the mature mammalian central nervous system （CNS） has the potential to replenish damaged neurons by proliferation and neuronal differentiation of adult neural stem/progenitor cells residing in the neurogenic regions in the brain. Furthermore, increasing evidence indicates that these endogenous stem/ progenitor cells may play regenerative and reparative roles in response to CNS injuries or diseases. In support of this notion, heightened levels of cell proliferation and neurogenesis have been ob- served in response to brain trauma or insults suggesting that the brain has the inherent potential to restore populations of damaged or destroyed neurons. This review will discuss the potential functions of adult neurogenesis and recent development of strategies aiming at harnessing this neurogenic capacity in order to repopulate and repair the injured brain.     

MR序列优化组合在创伤性脑损伤的诊断价值

目的分析MR诊断创伤性脑损伤(TBI)的价值,探讨TBI患者MR一站式诊断的可行性。方法对260例TBI病例进行MR序列组合扫描,包括小角度激发快速梯度回波序列(FLASH)、流动衰减反转恢复序列(FLAIR)、自旋回波(SE)T1WI、快速自旋回波(TSE)T2WI,比较MR序列组合和CT对各种类型TBI诊断的差异。结果脑实质内出血61例,MR显示61例,CT显示53例;硬膜下出血55例,MR显示55例,CT显示49例;硬膜外出血45例,MR显示45例,CT显示40例;脑挫(裂)伤35例,MR显示35例,CT显示25例;蛛网膜下腔出血35例,MR显示31例,CT显示33例;弥漫性轴索损伤29例,MR显示29例,CT显示5例。MR序列组合准确显示病变256例,CT为209例,两者差异有极显著统计学意义(P0.01),MR序列组合总体诊断敏感性高于CT。结论 MR序列组合(FLASH\FLAIR\T1WI\T2WI)诊断创伤性脑损伤明显优于CT,可列为TBI常规检查方法,实行TBI一站式诊断。     

预见性与相继性双侧去骨瓣减压治疗重型颅脑损伤疗效的差异

目的探讨分析预见性双侧去骨瓣减压术(BDC)与相继性双侧去骨瓣减压术治疗重型颅脑损伤的临床疗效差异,为临床优化治疗方案提供参考。方法将122例的重型颅脑损伤患者随机分为观察组和对照组。术后治疗方案基本相同,治疗3个月后患者均行格拉斯哥预后评分(GOS),比较两组患者术中急性脑组织膨出及术后切口疝发生率、GOS评分及并发症情况。结果术后观察组术中急性脑组织膨出、术后切口疝发生率均明显低于对照组(P0.05)。观察组GOS评分良好率明显高于对照组(P0.05),观察组病死率明显低于对照组(P0.05)。观察组中残率、重残率、植物化生存率与对照组比较,差异均无统计学意义(均P0.05)。观察组术后并发症发生率明显低于对照组(P0.05)。结论预见性双侧去骨瓣减压术用于治疗重型颅脑损伤近期临床疗效优于相继性双侧去骨瓣减压术,可显著改善预后及降低并发症,值得在临床推广应用。