Dejerine-Sottas disease with a novel de novo dominant mutation, Ser 149 Arg, of the peripheral myelin protein 22

The Ser149Arg mutation of peripheral myelin protein 22 (PMP22) was found in a 19-year-old woman with a sporadic case of Dejerine-Sottas disease. The patient showed delayed motor development. She walked for the first time with support at the age of 2 years. Scoliosis developed at age 4 years. Her walking ability was best at age 11. Thereafter, she showed progressive muscle weakness and sensory disturbances in the distal extremities. At the age of 18 years, the use of a wheelchair became necessary. Motor and sensory nerve conduction studies showed absent motor and sensory responses on electrical stimulation of the limb nerves. A sural nerve biopsy specimen showed marked decreases in the numbers of both large and small myelinated fibers, abundant onion-bulb formation, and hypomyelination. Electron microscopic observation revealed the presence of demyelinated axons and myelin sheaths disproportionately thin relative to axon diameter. That this was a de novo mutation was established by parentage testing and PMP22 gene analysis of the parents. The mutation seems to be novel and dominant. Received: 12 April 1999 / Accepted: 14 June 1999     

大鼠新基因PMP22CD的克隆以及多克隆抗体的制备

目的:通过PCR克隆PMP22CD基因,构建原核表达载体PET-32a(+)/PMP22CD,表达并纯化蛋白,制备多克隆抗体,为研究该基因的功能奠定基础.方法:通过PCR的方法克隆PMP22CD基因,选择抗原性较强的C-端,构建原核表达载体PET32a(+)/PMP22CD,在大肠杆菌BL21(DE3 Lysis)中诱导表达,SDS-PAGE分析重组蛋白以包涵体的形式存在,应用电洗脱的方式获得重组蛋白,免疫新西兰大白兔,获得抗血清,通过琼脂糖双扩和Western Blot检测抗血清效价和特异性.结果:经测序鉴定成功克隆PMP22CD基因,并构建PET-32a(+)/PMP22CD重组质粒,表达融合蛋白,免疫新西兰大白兔,获得PMP22CD多克隆抗体.结论:得到了纯化的PET-32a(+)/PMP22CD融合蛋白,获得了效价高、特异性强的抗体.     

HPLC测定赤参丹中丹酚酸B含量

目的为保证药物安全有效,完善赤参丹质量标准,对赤参丹中丹酚酸B进行了含量测定方法的研究。方法HPLC色谱条件：Kromasoil C18（250mm×4．6mm,5μm）;甲醇．乙腈-甲酸-水（28：10：1：61）为流动相,检测波长为286nm,流速1．0mL·min^-1。结果丹酚酸B在浓度0．1083～1．2998μg内线性关系良好（r=0．9998）。样品的平均回收率为98．7％,RSD为1．7％。结论本方法简便可靠,结果稳定,重复性好,可准确测定赤参丹中丹酚酸B的含量。     

妇科手术中发现的原发性阑尾癌5例分析

 目的  探讨阑尾癌与右侧附件肿瘤的异同点,以期提高阑尾癌术前诊断率。方法  本文就临床诊断附件肿瘤而行妇科手术中确诊为阑尾癌或伴发腹腔假黏液瘤(pseudomyxoma peritonei,PMP)的5例患者进行分析,总结临床症状、影像学检查、胃肠镜检查、血清肿瘤标志物、术中发现等方面的特征。结果  阑尾癌与右侧附件肿瘤在临床表现、影像学、生化指标等方面有很多共同点,但特异性不足。结论  虽然阑尾肿瘤非常罕见,但对于右侧盆腔肿块要充分考虑阑尾来源的可能性,从影像学等各方面入手可提高阑尾癌的术前诊断率。     

罕见病网络互助信息平台构建及模式探析

以腹膜假性黏液瘤网络交流互助平台的构建升级与发展为例,构建罕见病网络互助信息平台模型,推广罕见疾病网络互助模式,指出存在的问题及相应的解决办法。     

Myelin structure is unaltered in chemotherapy-induced peripheral neuropathy

Purpose

Alterations in mRNA for myelin proteins are reported in animal models of chemotherapy-induced peripheral neuropathies (CIPN); however, ultrastructural changes in aldehyde-fixed and plastic-embedded myelin are not evident by electron microscopy. Therefore, we used X-ray diffraction (XRD) to investigate more subtle changes in myelin sheath structure from unfixed nerves.

Experimental design

We used in vivo chronic animal models of CIPN in female Wistar rats, administering cisplatin (CDDP 2 mg/kg, i.p. twice/week), paclitaxel (PT 10 mg/kg, i.v. once/week) or bortezomib (0.20 mg/kg, i.v. three times/week) over a total period of 4 weeks. Animal weights were monitored, and tail nerve conduction velocity (NCV) was determined at the end of the treatments to assess the occurrence of peripheral neuropathy. Sciatic nerves were collected and the myelin structure was analyzed using electron microscopy (EM) and XRD.

Results

All the rats treated with the chemotherapy agents developed peripheral neuropathy, as indicated by a decrease in NCV values; however, light and electron microscopy indicated no severe pathological alterations of the myelin morphology. XRD also did not demonstrate significant differences between sciatic nerves in treated vs. control rats with respect to myelin period, relative amount of myelin, membrane structure, and regularity of membrane packing.

Conclusions

These results indicate that experimental peripheral neuropathy caused by CDDP, PT, and bortezomib—which are among the most widely used chemotherapy agents—does not significantly affect the structure of internodal myelin in peripheral nerve.     

Early onset demyelinating Charcot‐Marie‐Tooth disease caused by a novel in‐frame isoleucine deletion in peripheral myelin protein 2

Peripheral myelin protein 2 (PMP2) is a small protein located on the cytoplasmic side of compact myelin, involved in the lipids transport and in the myelination process. In the last years few families affected with demyelinating Charcot‐Marie‐Tooth neuropathy (CMT1), caused by PMP2 mutations, have been identified. In this study we describe the first case of a PMP2 in‐frame deletion. PMP2 was analyzed by direct sequencing after exclusion of the most frequent CMT‐associated genes by using a next generation sequencing (NGS) genes panel. Sanger sequencing was used for family's segregation analysis. Molecular modeling analysis was used to evaluate the mutation impact on the protein structure. A novel PMP2: p.I50del has been identified in a child with early onset CMT1 and in three affected family members. All family members show an early onset demyelinating neuropathy without other distinguish features. Molecular modeling analysis and in silico evaluations do not suggest a strong impact on the overall protein structure, but a most likely altered protein function. This study suggests the importance to add PMP2 in CMT NGS genes panels or, at most, to test it after major CMT1 genes exclusion, due to the lack of diagnostic‐addressing additional features.