Research progress on autophagic flux regulation in cataract / 国际眼科杂志(Guoji Yanke Zazhi)

Autophagic flux refers to a series of dynamic process of autophagic bilayer membrane formation, autophagosome formation, autophagolysosomes formation and degradation. The etiology of cataract is complex, including congenital abnormalities in lens development due to genetic mutations, oxidative damage due to aging, abnormalities in glucose metabolism due to diabetes, and proliferation of lens epithelial cells(LECs)stimulated by postoperative inflammatory factor, all of which are associated with the development of cataracts. A growing number of research in recent years have discovered that altering the status of LECs can contribute to the pathophysiological process of cataract by regulating autophagic flux. This review summarized the impacts of autophagic flux regulation on cataract.

Biocompatibility and effect on bone formation of a native acellular porcine pericardium: Results of in vitro and in vivo / 北京大学学报(医学版)

OBJECTIVE@#To examine the morphology and biocompatibility of a native acellular porcine pericardium (APP) in vitro and to evaluate its barrier function and effects on osteogenesis when used in guided bone regeneration (GBR) in vivo.@*METHODS@#First, the morphology of APP (BonanGenⓇ) was detected using a scanning electron microscope (SEM). Next, for biocompatibility test, proliferation of human bone marrow mesenchymal stem cells (hBMSCs) were determined using cell counting kit-8 (CCK-8) after being seeded 1, 3 and 7 days. Meanwhile, the cells stained with phalloidine and 4, 6-diamidino-2-phenylindole (DAPI) were observed using a confocal laser scanning microscopy (CLSM) to view the morphology of cell adhesion and pattern of cell proliferation on day 5. A 3-Beagle dog model with 18 teeth extraction sockets was used for the further research in vivo. These sites were randomly treated by 3 patterns below: filled with Bio-OssⓇand coverd by APP membrane (APP group), filled with Bio-OssⓇand covered by Bio-GideⓇmembrane (BG group) and natural healing (blank group). Micro-CT and hematoxylin-eosin (HE) were performed after 4 and 12 weeks.@*RESULTS@#A bilayer and three-dimensional porous ultrastructure was identified for APP through SEM. In vitro, APP facilitated proliferation and adhesion of hBMSCs, especially after 7 days (P < 0.05). In vivo, for the analysis of the whole socket healing, no distinct difference of new bone ratio was found between all the three groups after 4 weeks (P>0.05), however significantly more new bone regeneration was detected in APP group and BG group in comparison to blank group after 12 weeks (P < 0.05). The radio of bone formation below the membrane was significantly higher in APP group and BG group than blank group after 4 and 12 weeks (P < 0.05), however, the difference between APP group and BG group was merely significant in 12 weeks (P < 0.05). Besides, less resorption of buccal crest after 4 weeks and 12 weeks was observed in APP group of a significant difference compared in blank group (P < 0.05). The resorption in BG group was slightly lower than blank group (P>0.05).@*CONCLUSION@#APP showed considerable biocompatibility and three-dimentional structure. Performing well as a barrier membrane in the dog alveolar ridge preservation model, APP significantly promoted bone regeneration below it and reduced buccal crest resorption. On the basis of this study, APP is a potential osteoconductive and osteoinductive biomaterial.

Efficacy of two barrier membranes and deproteinized bovine bone mineral on bone regeneration in extraction sockets: A microcomputed tomographic study in dogs / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effect of two barrier membranes [multilaminated small intestinal submucosa (mSIS) and bioresorable collagen membrane (Bio-Gide)] combined with deproteinized bovine bone mineral Bio-Oss on guided bone regeneration through a canine extraction sockets model.@*METHODS@#The distal roots of 18 premolars of the Beagle' s bilateral maxillary and mandibular were removed, and 18 extraction sockets were obtained. They were randomly divided into 3 groups, and the following procedures were performed on the sockets: (1) filled with Bio-Oss and covered by mSIS (mSIS group), (2) filled with Bio-Oss and covered by Bio-Gide (BG group), (3) natural healing (blank control group). Micro-computed tomograph (Micro-CT) was performed 4 and 12 weeks after surgery to eva-luate the new bone regeneration in the sockets of each group.@*RESULTS@#The postoperative healing was uneventful in all the animals, and no complications were observed through the whole study period. Micro-CT analysis showed that the new bone fraction in the mSIS group and the BG group was significantly higher than that in the blank control group at the end of 4 weeks and 12 weeks (P < 0.05), and more new bone fraction was observed in the mSIS group than in the BG group, but the difference was not statistically significant (P>0.05). The new bone fraction of coronal third part of the socket in the mSIS group and BG group at the end of 4 weeks were significantly higher than that of the middle and apical third part of each group (P < 0.05). The values of bone mineral density were similar at 4 weeks in all the groups (P>0.05), but were significantly higher than that in the control group at the end of 12 weeks (P < 0.05). The bone morphometric analysis showed that the trabecular number and trabecular spacing were significantly better in the mSIS group and the BG group than in the control group at the end of 4 weeks and 12 weeks (P < 0.05), while the value in the mSIS group was slightly higher than in the BG group, but the difference was not statistically significant (P>0.05). The difference in trabecular thickness between all the groups was not statistically significant (P>0.05).@*CONCLUSION@#mSIS membrane as a barrier membrane combined with deproteinized bovine bone mineral can enhance new bone formation in canine extraction sockets, similar to Bio-Gide collagen membrane.

Preparation and osteogenic effect study of small intestinal submucosa sponge / 北京大学学报(医学版)

OBJECTIVE@#To prepare and evaluate the basic properties in vitro of a novel small intestinal submucosa (SIS) sponge, and to describe the bone formation ability of the SIS sponge in vivo.@*METHODS@#The SIS sponge was prepared by freeze-drying method. To evaluate the physicochemical properties of the sponge, electron microscope observation, porosity test, water absorption ability and mechanical property were conducted in vitro. The cytotoxicity of the SIS sponge was performed by cell counting kit-8 method. In vivo experiments, eighteen extraction sockets of premolar of three Beagle dogs were randomly divided into three groups: SIS sponge group (SIS sponge), positive control group (Bio-Oss granules and Bio-Gide membrane) and control group(no treatment). The animals were sacrificed 4 weeks and 12 weeks after operation, and micro computed tomography (Micro-CT) was applied to measure the bone volume fraction (BV/TV) and bone mineralized density (BMD). The data were analyzed with one-way ANOVA.@*RESULTS@#The average pore diameter of the SIS sponge was (194.90±30.39) μm, the porosity was 92.31%±0.24%, the water absorption rate was 771.50%±40.90%, and the compressive elastic modulus was (2.20±0.19) kPa. There was no significant difference in cell proliferation ability between SIS sponge and control group (P>0.05). Micro-CT quantitative results showed that BV/TV of SIS sponge group (52.81%±3.21%) and positive control group (58.30%±9.36%) were significantly higher than that of control group (38.65%±4.80%) 4 weeks after operation (P < 0.05). The BMD of SIS sponge group [(887.09±61.02) mg/cm3], positive control group [(952.05±132.78) mg/cm3] and control group [(879.29±74.27) mg/cm3] showed no statistical difference 4 weeks after operation (P>0.05). The BV/TV of positive control group (60.57%± 6.56%) was significantly higher than that of SIS sponge group (47.89%±3.59%) and control group (42.99%±2.54%) 12 weeks after operation (P < 0.05). BMD of SIS sponge group [(1047±89.95) mg/cm3] and positive control group [(1101.37±98.85) mg/cm3] were significantly higher than that of control group [(890.36±79.79) mg/cm3] 12 weeks after operation (P < 0.05).@*CONCLUSION@#The SIS sponge has satisfying physicochemical properties and biocompatibility. The SIS sponge significantly increased bone volume fraction in the early stage of bone formation (4 weeks) and bone mineralized density in the late stage of bone formation (12 weeks).

Comparison of clinical curative effect between open surgery and endovascular repair of abdominal aortic aneurysm in China / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To compare clinical curative effects of open surgery (OS) or endovascular repair (EVAR) for patients with abdominal aortic aneurysm (AAA) in China.</p><p><b>DATA SOURCES</b>We performed a comprehensive search of both English and Chinese literatures involving case studies on retrograde OS or EVAR of AAA in China from January 1976 to December 2010.</p><p><b>STUDY SELECTION</b>According to the inclusion criteria, 76 articles were finally analyzed to compare patient characteristics, clinical success, complications, and prognosis.</p><p><b>RESULTS</b>We analyzed a total of 2862 patients with 1757 undergoing OS (OS group) and 1105 undergoing EVAR (EVAR group). There was no significant difference in the success rate of the procedures. Operative time, length of ICU stay, fasting time, duration of total postoperative stay, blood loss, and blood transfusion requirements during the procedure were significantly lower in the EVAR group. A 30-day follow up revealed more cardiac, renal, pulmonary, and visceral complications in the OS group (P < 0.01). Low-limb ischemia, however, was more common in the EVAR group (P < 0.05). The 30-day mortality rate, including aorta-related and non-aorta related mortality, was significantly lower in the EVAR group (P < 0.01). In the follow-up period, there were more patients with occlusions of artificial vessel and late endoleak in the EVAR group (P < 0.01). The overall late mortality rate was higher in the OS group (P < 0.01), especially non-aorta-related late mortality and mortality during the fourth to the sixth year (P < 0.01).</p><p><b>CONCLUSIONS</b>EVAR was safer and less invasive for AAA patients. Patients suffered fewer complications and recovered sooner. However, complications such as artificial vessel occlusion, low-limb ischemia, and endoleak were common in EVAR. Clinicians should carry out further research to solve these complications and improve the efficacy of EVAR.</p>

The mechanism of transforming growth factor beta1 in myofibroblast differentiation / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the mechanism underlying myofibroblast differentiation induced by transforming growth factor (TGF) beta1 in obliterative bronchiolitis following lung transplantation.</p><p><b>METHODS</b>Heterotopic tracheal transplantation was performed in Smad3 wild-type and knock-out mice to simulate the lung transplantation in human. Murine tracheal fibroblasts cultivated in primary culture were used for in vitro study. Immunohistochemistry, immunocytochemistry, Western Blotting, RT-PCR and DNA electrophoresis mobility gel shift assay were conducted to detect the expression of alpha-smooth muscle actin (alphaSMA), the marker of fibroblast-myofibroblast differentiation, and the activation of Smad3, p38 and ERK1/2.</p><p><b>RESULTS</b>In affected airways of experimental obliterative bronchiolitis, abundant expression of alphaSMA were found. In vitro study for tracheal fibroblasts, the activation of Smad3 by TGF-beta1 presents as three major forms, phosphorylation, nuclear translocation and DNA binding. In Smad3 wild-type fibroblasts, TGF-beta1 induces the increase of the myofibroblasts transformation, characterized by the elevation of alphaSMA, both at transcription and protein level. While in Smad3 knock-out fibroblasts, the transformation of myofibroblasts induced by TGF-beta1 is significantly decreased (t = 2.080, P = 0.027; t = 1.982, P = 0.032), but not completely abolished. Further study in Smad3-deficient fibroblasts demonstrates that p38 and ERK1/2 could be activated by TGF-beta1 and result in fibroblast differentiation.</p><p><b>CONCLUSIONS</b>TGF-beta1 could promote the transformation of fibroblasts into myofibroblasts in Smad3 dependent and independent signal pathways, especially the Smad3 dependent path, and result in the development of obliterative bronchiolitis.</p>