Hereditary neuropathy with liability to pressure palsies

Summary Clinical, neurophysiological and pathological investigations were carried out in 11 affected members of 2 families with hereditary neuropathy with liability to pressure palsies (HNPP). The observations were related to findings in 261 cases of 47 families published in the literature. It was concluded that HNPP is a nosological entity characterized by the following diagnostic criteria: (1) an autosomal dominant inheritance; (2) the clinical presentation of a recurrent mononeuropathy simplex or multiplex, frequently related to an inadequate trauma to peripheral nerves; (3) a significant slowing of motor and sensory conduction velocity in clinically affected, but also in clinically unaffected nerves; (4) characteristic morphological findings in sural nerve biopsy featuring tomaculous swellings of myelin sheaths, transnodal myelination and segmental demyelination. The pathogenesis of HNPP is not clear. Hypothetical explanations of the pathogenesis of HNPP are discussed.In memory of Albert Bischoff (1921–1981), Professor of Neurology, University of Berne     

Richter’s hernia occurring through a 5-mm laparoscopy sheath incision

We report a case of postoperative Richter’s hernia presenting through a 5-mm sheath incision. A 58-year-old woman having undergone laparoscopic hysterectomy 8 days before presented with severe left abdominal pain, nausea and light-headedness. The hypothesis of a sigmoid volvulus was suggested based on peroperative rectum and sigmoid release, the X-ray finding, and pain evolution. A secondary laparoscopic procedure allowed both diagnosis of a Richter’s hernia through a 5-mm sheath incision and surgical repair of the hernia. The use of this sheath during the laparoscopic vagina suture caused extension of the wound. Large 5-mm sheath defect sufficient for a Richter’s hernia can be created by multiple passes with small instruments and require surgical closure at the end of laparoscopy. Laparoscopy is useful in cases of postoperative complications, particularly when other complementary examinations are less informative.     

Clinico‐genetic aspects of a pediatric non‐neurofibromatosis type 1 malignant triton tumor with loss of chromosome X

Malignant triton tumor (MTT) is an aggressive peripheral nerve sheath tumor with rhabdomyoblastic differentiation. Less than 100 cases have been described, being mostly male children with type 1 neurofibromatosis. We report a 6‐year‐old female with MTT and no diagnostic criteria for neurofibromatosis type 1. Cytogenetic analysis showed a 46,X,‐X[4]/46,XX[16] karyotype. She underwent a transfemoral amputation and chemotherapy and is free of disease 15 months after diagnosis. The few cytogenetic studies of MTT described in the literature have been inconclusive. Further cytogenetic analyses are needed to understand the role of chromosome X monosomy in the pathogenesis of this rare tumor. Pediatr Blood Cancer 2012; 59: 1320–1323. © 2012 Wiley Periodicals, Inc.     

Changes in the connective tissue sheath of Wistar rat nerve with aging

The alterations due to aging in the peripheral nerves can affect the physiology of these structures. Thus, the purpose of the present study was to describe the activity of the MMP-2 and MMP-9, as well as the structure and composition of the extracellular matrix of the rat sciatic nerve during maturation and aging. Our results have shown that the extracellular matrix of the sciatic nerve of 30-, 180- and 730-day-old Wistar rats present ultrastructural, morphometrical and biochemical changes during aging. The perineurium was the structure most affected by age, as evidenced by a decrease in thickness and in collagen fibril content. Cytochemical analysis detected proteoglycans in the basal membrane of Schwann cells and around perineural cells, as well as on the collagen fibrils of the perineurium and endoneurium at all ages. Biochemical analyses showed that the quantity of non-collagenous proteins was higher in 730-day-old animals compared to other ages, while the uronic acid content was higher in 30-day-old animals. Morphometrical analysis detected greater numbers of myelinated fibers and increased myelin thickness in 180-day-old animals. Zymography analysis detected greater amounts and activity of MMP-2 and MMP-9 in 180- and 730-day-old animals compared to younger rats. In conclusion, our results showed changes in the structural organization and composition of extracellular matrix of the sciatic nerve during aging, such as increase in the non-collagenous protein content and higher MMP-2 and MMP-9 activity, decrease in uronic acid concentration and in collagen fibril content in the perineurium, as well as degeneration of nerve fibers.     

Ursolic acid induces neural regeneration after sciatic nerve injury

In this study,we aimed to explore the role of ursolic acid in the neural regeneration of the injured sciatic nerve.BALB/c mice were used to establish models of sciatic nerve injury through unilateral sciatic nerve complete transection and microscopic anastomosis at 0.5 cm below the ischial tuberosity.The successfully generated model mice were treated with 10,5,or 2.5 mg/kg ursolic acid via intraperitoneal injection.Enzyme-linked immunosorbent assay results showed that serum S100 protein expression level gradually increased at 1-4 weeks after sciatic nerve injury,and significantly decreased at 8 weeks.As such,ursolic acid has the capacity to significantly increase S100 protein expression levels.Real-time quantitative PCR showed that S100 mRNA expression in the L4-6 segments on the injury side was increased after ursolic acid treatment.In addition,the muscular mass index in the soleus muscle was also increased in mice treated with ursolic acid.Toluidine blue staining revealed that the quantity and average diameter of myelinated nerve fibers in the injured sciatic nerve were significantly increased after treatment with ursolic acid.10 and 5 mg/kg of ursolic acid produced stronger effects than 2.5 mg/kg of ursolic acid.Our findings indicate that ursolic acid can dose-dependently increase S100 expression and promote neural regeneration in BALB/c mice following sciatic nerve injury.     

Developmental defects in zebrafish for classification of EGF pathway inhibitors

One of the major challenges when testing drug candidates targeted at a specific pathway in whole animals is the discrimination between specific effects and unwanted, off-target effects. Here we used the zebrafish to define several developmental defects caused by impairment of Egf signaling, a major pathway of interest in tumor biology. We inactivated Egf signaling by genetically blocking Egf expression or using specific inhibitors of the Egf receptor function. We show that the combined occurrence of defects in cartilage formation, disturbance of blood flow in the trunk and a decrease of myelin basic protein expression represent good indicators for impairment of Egf signaling. Finally, we present a classification of known tyrosine kinase inhibitors according to their specificity for the Egf pathway.     

加长型鞘在MPCNL治疗嵌顿性输尿管上段结石中的应用

目的：探讨加长型鞘在MPCNL术治疗嵌顿性输尿管上段结石中的应用效果。方法：回顾性分析本院2010年1月-2013年12月经MPCNL治疗嵌顿性输尿管上段结石112例患者的临床资料，其中2010年1月-2012年2月的60例作为对照组，术中仅用普通peel-away鞘，2012年3月-2013年12月的52例作为加长型鞘组，在普通peel-away鞘基础加用加长型鞘，观察比较两组患者的手术时间、术中出血量、术后并发症发生情况。结果：加长型鞘组的手术时间、术中出血量均明显少于对照组，术后并发症发生率明显低于对照组，差异均有统计学意义（P〈0.05）。结论：应用加长型鞘能明显提高MPCNL治疗嵌顿性输尿管上段结石的有效率，且安全性更高，值得临床推广应用。     

Acute and subacute myelopathy

Myelopathy is a term referring to any pathologic process affecting the spinal cord, and encompasses a broad spectrum of etiologies. The first step is to categorize myelopathy, according to the time to reach maximum deficit. Myelopathies are commonly classified as acute, subacute or chronic, for which the etiologies are totally different. Myelopathy is considered acute when the symptoms progress to their nadir in maximum 21 days after onset. Due to heterogeneity in pathogenesis, and the overlap in the clinical and imaging presentation among etiologies, acute myelopathy is considered as a diagnostic dilemma. A simple and efficient algorithm for timely identification of the underlying cause is thus useful. In this review, we provide a simplified approach for the differential diagnosis among all causes of acute myelopathies, and describe the principal clinical and imaging features of the main etiologies in adults, including recently characterized antibody-mediated myelitis, and its mimics.