Advances in the Pathogenic Research of Female Carriers with Symptomatic Duchenne Muscular Dystrophy / 现代生物医学进展

DMD/BMD is a X-linked recessive hereditary disease.It predominantly affects males.While female carriers do not have symptoms,due to their inactive X chromosome make it present mosaic.Recently,more and more papers reported that a clinically significant proportion of DMD/BMD female carriers have symptoms.They presented variable degrees of symptoms.But the mechanism of the pathogencity is still not clear.Most of the research considered that the dominating reason is the skewed X inactivation.It means that the predominant expression of the DMD mutant allele make the normal one have weak expression,thus no function dystrophin proteins could be generate,manifested as DMD/BMD.In this paper,we mainly summarized the relationship between skewed X inactivation and pathogenicity of the symptomatic DMD female carriers.

Maintenance of undifferentiated state of human embryonic stem cells in chemical defined medium at high clone density without exogenous cell factors / 中南大学学报(医学版)

Objective To establish human embryonic stem cells (hESCs) feeder-independent and cell factor-free culture system. Methods Effect of high and low clone densities of hESCs culture was compared and impact of the clone densities to hESCs culture media was analyzed. Results HESCs could maintain their undifferentiated states at high clone density (34 clones/cm2) without cell factors. At the same time,the bone morphology protein (BMP)-like induction of N2 and B27 supplements (NB) medium could be modulated by the clone density,and high level of BMP-like induction was accompanied by high clone density. Conclusion High clone density of hESCs can change the environments by themselves to maintain the undifferentiated states,which provides a new clue to explore the mechanism of undifferentiated states of hESCs and simplify the culture medium.