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.

Under the background of "Three Whole Education", the College of Biomedical Engineering of Chongqing Medical University builds the rule of undergraduate tutors, promotes the effective connection among the entrance -in school -graduation education, integrates the innovative education and teaching throughout into the undergraduate period, and implements "4+1" education models of theory teaching - ability training - competetion incubation - atmosphere building to create innovative classroom transcripts, finally realizing the all-around education of innovative undergraduate talents. Through the innovation and practices, we will continue to refine educational effects.

Objective:To explore the changes of bone mineral density (BMD) and type H vessel, which was recently identified as strongly positive for CD31 and Endomucin (CD31 hiEmcn hi) in long bone from ovariectomized (OVX) mice compared withSham group. Methods:C57BL/6Jwild-type mice were used for experiments and bone tissuewas collected. Eight-week-old female mice were randomly divided into bilateral ovariectomy (OVX) and a sham operation (Sham). The bilateral ovaries were exposed and removed in the OVX group. In the sham group, the ovaries were only exposed but left intact. After 4weeks, these mice were killed for experiment and the femurs were collected for Micro CT scanning in order to observe the changes of bone mineral density (BMD) and trabecular indexes, including bone volume (BV), total volume of interest (TV), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number (Tb.N). The fresh tibia of each mouse was fixed, decalcified, dehydrated and embedded for immunostaining. All experimental data were analyzed with t-test. Results:Mouse femora from two groups were dissected at 4 week time points, and the attached soft tissue was completely removed for Micro CT scanning. BMD in OVX is 0.11±0.01 g/cm 3 and 0.21±0.01 g/cm 3 in Sham, which indicated the BMD in OVX significantly decreased. The results showed significant difference between the groups ( P=0.001). The microarchitecture in trabecular bone changed. BV/TV in OVX is 11.52%±1.77% and 25.87%±1.31% in Sham, which indicated the BV/TV in OVX significantly decreased. The results showed significant difference between the groups ( P<0.05). Tb.N in OVX is 1.67±0.33/mm and 2.95±0.82/mm in Sham, which indicated the Tb.N in OVX slightly decreased. The results showed no significant difference between the groups ( P=0.066). Tb.Th in OVX is 0.06±0.01 mm and 0.07±0.01 mm in Sham, which indicated the Tb.Th in OVX significantly thinned. The results showed significant difference between the groups ( P=0.021). Tb.Sp in OVX is 0.29±0.15 mm and 0.19±0.01 mm in Sham, which indicated the Tb.Sp in OVX significantly increased. The results showed significant difference between the groups ( P<0.05). In the groups BMD decreased and trabecular microstructure was broken. Both BMD and trabecular indexes (BV/TV, Tb. Th, Tb. Sp) showed significant changes in OVX group compared with Sham ( P<0.05) except Tb.N. We next examined the expression of CD31 and EMCN via immunostaining in order to observe the changes of type H vessel.By immunostaining, the percentage of HV/TV in OVX group was 9.14%±0.99% and 29.33%±1.22% in the sham-operated mice. Dramatically decreased type H vessels in the metaphysis of OVX mice were observed compared with that of Sham control mice. The results showed significant difference between the groups ( P<0.05). Conclusion:In this study, ovariectomized mice, a widely used model for postmenopausal osteoporosis, exhibited significantly reduced type H vessels accompanied by reduced BMD, which indicatedtype H vessel involved in the occurrence of postmenopausal osteoporosis.

At present, there is still a big gap between China and developed countries in the field of high-end medical devices, and the ability of independent innovation needs to be improved. In order to comprehensively cultivate innovative talents in the field of medical devices and promote the development of the field of medical devices, the biomedical engineering major of Chongqing Medical University has put forward a "Trinity" innovative talent training system in the field of medical devices, including the teaching of theoretical knowledge, the improvement of practical skills and the guarantee of the innovation system, and established a four stage curriculum system framework of "Perception-Understanding-Enlightenment-Challenge" to form a characteristic course with ultrasonic treatment equipment as the main line. After three years of practice, the results of this training mode show that the innovative ability, professional connotation construction quality and employment postgraduate entrance examination rate of our college students have been steadily improved. The exploration of this talent training mode has reference significance for the cultivation of innovative talents in the field of medical devices in higher medical colleges and universities in China.