卵胞质移植、克隆与逆向克隆

目的:最近人类卵细胞间的胞质移植被作为人类辅助生殖生物技术的手段并成为研究热点。本文回顾了该领域的研究进展和存在的问题,并以此为基础提出“逆向克隆技术”这一新概念。资料来源:应用计算机检索PUBMED 1998-01/2006-12期间的相关文章,检索词为“ooplasmic transfer,mitochondria heteroplasmy,animal cloning”,并限定文章语言种类为English。同时计算机检索万方数据库1998-01/2006-12期间的相关文章,检索词为“胞质转移,线粒体异质性,动物克隆”,并限定文章语言种类为中文。资料选择:对资料进行初审,并查看每篇文献后的引文。纳入标准:文章所述内容应与卵胞质移植、克隆或逆向克隆研究相关。排除标准:重复研究或Meta分析类文章。资料提炼:共收集到126篇相关文献,31篇文献符合纳入标准,排除的95篇文献为内容陈旧或重复。符合纳入标准的31篇文献中,17篇涉及卵胞质移植,13篇涉及动物克隆,1篇涉及逆克隆。资料综合:人类的生殖技术领域发展迅速,卵胞质移植技术得到广泛应用。研究表明,卵胞质对受精和胚胎发育具有重要作用,其中线粒体与受精和胚胎发育关系最为密切。大量实验对细胞质与细胞核的相互作用、基因组的重编程机制上进一步研究,同时也在技术上不断改进。克隆技术有广阔的应用前景,同时也存在着不少问题,基于此提出以胞质转移为基础的“逆向克隆技术”。结论:线粒体对卵母细胞的受精和胚胎发育有显著影响,但卵胞质移植可能导致线粒体的异质性及其潜在的问题还需要进一步研究。以卵胞质转移为基础的“逆向克隆技术”是否能达到克隆动物的结果前景喜人。     

Involvement of the Intestinal Microbiota in the Appearance of Multiple Sclerosis: Aloe vera and Citrus bergamia as Potential Candidates for Intestinal Health

Multiple sclerosis (MS) is a neurological and inflammatory autoimmune disease of the Central Nervous System in which selective activation of T and B lymphocytes prompts a reaction against myelin, inducing demyelination and axonal loss. Although MS is recognized to be an autoimmune pathology, the specific causes are many; thus, to date, it has been considered a disorder resulting from environmental factors in genetically susceptible individuals. Among the environmental factors hypothetically involved in MS, nutrition seems to be well related, although the role of nutritional factors is still unclear. The gut of mammals is home to a bacterial community of about 2000 species known as the “microbiota”, whose composition changes throughout the life of each individual. There are five bacterial phylas that make up the microbiota in healthy adults: Firmicutes (79.4%), Bacteroidetes (16.9%), Actinobacteria (2.5%), Proteobacteria (1%) and Verrucomicrobia (0.1%). The diversity and abundance of microbial populations justifies a condition known as eubiosis. On the contrary, the state of dysbiosis refers to altered diversity and abundance of the microbiota. Many studies carried out in the last few years have demonstrated that there is a relationship between the intestinal microflora and the progression of multiple sclerosis. This correlation was also demonstrated by the discovery that patients with MS, treated with specific prebiotics and probiotics, have greatly increased bacterial diversity in the intestinal microbiota, which might be otherwise reduced or absent. In particular, natural extracts of Aloe vera and bergamot fruits, rich in polyphenols and with a high percentage of polysaccharides (mostly found in indigestible and fermentable fibers), appear to be potential candidates to re-equilibrate the gut microbiota in MS patients. The present review article aims to assess the pathophysiological mechanisms that reveal the role of the microbiota in the development of MS. In addition, the potential for supplementing patients undergoing early stages of MS with Aloe vera as well as bergamot fibers, on top of conventional drug treatments, is discussed.     

Six new cases of CRB2-related syndrome and a review of clinical findings in 28 reported patients

The Crumbs homolog-2 (CRB2)-related syndrome (CRBS-RS) is a rarely encountered condition initially described as a triad comprising ventriculomegaly, Finnish nephrosis, and elevated alpha-fetoprotein levels in maternal serum and amniotic fluid. CRB2-related syndrome is caused by biallelic, pathogenic variants in the CRB2 gene. Recent reports of CRB2-RS have highlighted renal disease with persistent proteinuria and steroid-resistant nephrotic syndrome (SRNS). We report six new and review 28 reported patients with pathogenic variants in CRB2. We compare clinical features and variant information in CRB2 in patients with CRB2-RS and in those with isolated renal disease. The kidneys were the most frequently involved body system and 11 patients had only renal manifestations with SRNS or nephrotic syndrome. Central nervous system involvement was the next most common manifestation, followed by cardiac findings that included Scimitar syndrome. There was a significant clustering of pathogenic variants for CRB2-RS in exons 8 and 10, whereas pathogenic variants in exons 12 and 13 were associated with isolated renal disease. Further information is needed to determine optimal management but monitoring for renal and ocular complications should be considered.