Objective To study the effects of hypoxia on repair of radiation damage and the possible mechanism. Methods Rat jejunal epithelium cell was taken as study object and divided into control group, irradiation group and irradiation-hypoxia group. The irradiation group was irradiated only once by 60 Co-? ray at the dose of 12 Gy and the irradiation-hypoxia group was treated with hypoxia (5% oxygen) for 6 h after irradiation. MTT was used to detect the survival rate of the irradiated cells, 3H-TdR incorporation was used to detect cell proliferation, and unscheduled DNA synthesis and single cell gel electrophoresis were used to detect DNA repair and flow cytometry was used to detect cell cycle. Results As compared with the irradiation group, the cells in the irradiation-hypoxia group repaired rapidly, proliferated obviously and the survival rate was increased about 10% (P

[Objective]Study on the Pathology shape structure of calcified cartilage one in Osteoarthritis knee joint and provide the theory for diagnosis and treatment of correlated disease.[Method]Osteoarthritis condyles of femur(n=21) were collected from knee joint replacement and the paraffin sections were prepared after fixation and decalcification.After stained with Safranin O/fast green,the shape structure of calcified cartilage zone was observed by microscope.[Result]Mean age of osteoarthritis patient was 65.57?7.43 yearsold;mean stature was(155.38+5.32)cm;mean weight was(59.95 ?8.99)kg;mean pathogenesis was(13.04?9.66) years.After stained with Safranin O/fast green,the pathological changes of calcified cartilage zone were defined as follow.Tidemark drift and thickening accompany with blood vessel invasion.The gap of tidemark increased width.Calcified cartilage zone desmoid changed or defect.[Conclusion]Calcified cartilage zone in Osteoarthritis knee joint taken place specific pathological changes.

Objective To evaluate the regulatory role of mTOR signaling in activation of renal interstitial fibroblasts and the potential effect on interstitial fibrosis. Methods 8-week old female C57BL/6 mice (n=30) underwent unilateral ureteral obstruction (UUO) to induce renal interstitial fibrosis. Animals were randomly divided into rapamycin (2 mg·kg-1· d-1) group and UUO group (vehicle-treated) (n=15 each group). Daily intraperitoneal injection of rapamycin or saline was applied to animals from day 1 before operation to the end of experiment.Three mice were sacrificed at day 1,3,7,14 respectively and kidneys were harvested for further analysis.NIH3T3 cells were stimulated by TGF-β for 12 hours with the presence or bsence of rapamycin (100 nmol/L). Results Immunofluorescent co-staining revealed that active fibroblasts highly expressed pS6K and α-SMA in kidney interstitium.Administation of rapamycin significantly inhibited activation of mTOR signaling in fibroblasts and ameliorated interstitial fibrosis of obstructed kidneys.Real-time PCR confirmed that rapamycin decreased the mRNA expression of FSP1,TGF-β,CTGF and Col4A1 in fibrotic kidneys. In vitro experiment revealed that TGF-β induced highly expression of pS6K and αSMA in cultured NIH3T3 cells,which could be markedly inhibited by rapamycin. Conclusions mTOR signaling highly activates in interstitial fibroblasts during kidney fibrosis.Inhibition of mTOR signaling by rapamycin decreases the activation of fibroblasts and ameliorates interstitial fibrosis.

Objective To establish osteochondral scaffolds with remained calcified cartilage zone for finding an ideal scaffold for tissue engineered repair of osteochondral defect.Methods Cartilage zone was harvested from fresh adult porcine knee to fabricate type Ⅱ collagen hydrogel.Bone blocks measuring 8 mm in diameter with calcified cartilage zone were prepared by trephine and acellular treatment was performed.Histological staining was used to identify complete removal of cells.To fabricate the osteochondral models containing calcified cartilage zone,type Ⅱ collagen was seeded onto the acellular bone blocks with calcified cartilage zone,lyophilized,and cross-linked with 10 g/L of genipin ethanol solution.Then cell seeding and scanning electron microscope were performed after the models were established.Results HE staining,toluidine blue staining,solid green staining,safranin O staining,and DAPI staining showed cells were completely removed from bone blocks by decellularized process.Porosity of type Ⅱ collagen sponge was (91.1 ±3.8) ％ and pore size was (79.7 ± 17.1) μm.Porosity of acellular bone blocks was (73.5 ±2.6)％ and pore size was (470.2 ± 158.8) μm.Cells seeded onto osteochondral scaffolds grew well by scanning electron microscope.Conclusion Osteochondral scaffolds with calcified cartilage zone provide good biocompatibility and suitable pore size and porosity and may be an ideal material for repairing osteochondral defect in tissue engineering.

Objective To investigate the effect of goat autologous serum at different concentrations on the proliferation of bone marrow-derived mesenchymal stem cells(bMSCs) for optimal serum dose.Methods Autologous serum was prepared from 6 goats at 12 months old,and their bMSCs were isolated from bone marrow.Then the obtain bMSCs were cultured in DMEM/F12 medium with supplement of 5%,10%,or 15% of corresponding autologous serum,and 10% fetal bovine serum served as control.The morphology of bMSCs,cells counting and MTT assay were observed or carried out.Results Morphology of the bMSCs in the different groups were similar.The proliferation of 5% autologous serum group was slower compared with that of 10% fetal bovine serum group(P

Esophageal cancer is a unique malignant disease in China. A fundamental difference exists between the Chinese population and the western population on esophageal cancer in terms of epidemiology, histogenesis, and carcinogenic risk factors. Therefore, ap-plying the western academic achievements to Chinese is difficult. Thus, Chinese scientists have the responsibility to conquer esopha-geal cancer in China. This article reviews the progress of esophageal cancer focused on the molecular mechanism for interactions of ge-netic and environmental risk factors and human esophageal multistage carcinogenesis.

Objective To investigate the feasibility of bone marrow mesenchymal stem cells (BMSCs) combined with type Ⅱ collagen-hyaluronic acid-oxidized chondroitin sulfate (Col Ⅱ-HA-OCS) biomimetic hydrogel to repair articular cartilage defect in porcine and the role of the transplanted cells played in the process of cartilage repair.Methods A articular cartilage defect model which remaining cartilage calcified zone was created in the knee of Bama minipigs,the autologous BMSCs was used as seeds for transplantation and was labeled by the 5,6-carboxyfluorescein diacetate succinimidyl ester (CFDA SE).Animals were randomly divided into three groups:Group A (blank group) was left untreated,group B (cell-free biomimetic hydrogel group) was filled with biomimetic hydrogel and group C (BMSCs combined with biomimetic hydrogel group) was filled with the CFDA SE labeled autologous BMSCs combined with biomimetic hydrogel.One month after the operation,BrdU labeled liquid was injected intravenously into the animals 24 h and 48 h before specimens were taken from the executed animals.Partial cartilage repaired tissue in Group C was taken,cryosectioned and stained with DAPI and BrdU immunofluorescence.Confocal laser scanning microscope was used to observe and count the cells.Specimens of the three groups were analyzed through gross observation and histological staining,and scored according to the international cartilage repair society (ICRS) gross morphological score and ICRS histological score.Results Laser scanning confocal microscopy showed (97.3 ± 2.6) ％ of the cells were derived from the implanted BMSCs in repaired tissue and that the ratio of these cells with proliferative capacity was (76.6 ± 2.5) ％.Gross observation suggested most of the cartilage defect areas in Group C were filled with ivory tissue,but those in Group A and B were still obvious depression.Histological staining showed the cartilage defect areas in Group C were filled with cartilage like tissue,which was well integrated with the surrounding normal cartilage,presented a few cartilage lacunas could be seen,and had contents of Col Ⅱ and glycosaminoglycan similar with the adjacent normal cartilage.There was almost no filler in the defect area in Group A.There was little fibrous tissue in the defect area in Group B.ICRS gross score was (8.3 ± 1.0) points in Group C,higher than that in Group A [(0.5 ± 0.6) points] and Group B [(2.3 ± 0.5) points] (P ＜ 0.05).ICRS histological score was (10.3 ± 2.4) points in Group C,higher than that in Group A [(0.5 ± 0.6) points] and Group B [(4.5 ± 1.0) points] (P ＜ 0.05).Conclusions BMSCs combined with Col Ⅱ-HA-OCS biomimetic hydrogel for repairing porcine articular cartilage defects can achieve satisfactory results.Implanted BMSCs are the main component of the cell composition in the repaired tissue and gradually differentiated into chondrocytes.

Objective To investigate the role of PI3K/Akt signaling in the regulation of epithelial-mesenchymal transition (EMT) of peritoneal mesothelial cells (PMCs) in peritoneal dialysis in vitro and in vivo.Methods The level of Phosphorylated serine/threonine kinase Akt and the expression of EMT associated gene and protein,including ZO-1,Vimentin and FN,were measured in mice EMT model.In vitro study,phosphorylation level and nuclear translocation of Akt,ZO-1 and Vimentin expression induced by TGF-β1 in human peritoneal mesothelial cells (HPMCs) were also observed.Moreover,HPMCs were pre-treated by one of PI3K/Akt inhibitor,LY294002,or transfected with dominant-negative Akt plasmid to inhibit PI3K/Akt signaling,then analyzed its effect on Zo-1 and Vimentin expression induced by TGF-β1.Results Compared with the control,thickened parietal peritoneum and remarkable decrease in mRNA and protein of the epithelial marker ZO-1,and notable increased in the expression of mesenchymal markers Vimentin and FN were observed in PD mice (all P ＜ 0.01).Moreover,the phosphorylation of Akt also significantly increased under above condition (P ＜ 0.01).In vitro study,with the stimulation of TGF-β1,the expression of Zo-l was down-regulated,while the expression of Vimentin increased (all P ＜ 0.01).In addition,TGF-β1 remarkably increased pAkt in HPMCs (all P ＜ 0.01) in dose-dependent.However,LY294002 and DN-Akt dramatically inhibited the vimentin expression in HPMCs induced by TGF-β1 after inhibition of pAkt.On the other hand,the expression of ZO-1 also was restored (P ＜ 0.01).Conclusion PI3K/Akt signaling is involved in EMT of peritoneal mesothelial cells in peritoneal dialysis,and may be a new target for the prevention and treatment of peritoneal fibrosis during PD.

Objective To investigate the role of oxidative stress in the epithelial-to-mesenchymal transdifferentiation (EMT) of peritoneal mesothelial cells in rat model of peritoneal fibrosis and the effect of probucol on peritoneal fibrosis. Methods The rat model of peritoneal fibrosis was induced by 4.25% high glucose peritoneal dialysis fluid (PDF). The rats were randomly divided into 4 groups:the control group, the saline group, the peritoneal fibrosis group, and the probucol group. A 4 hour peritoneal equilibration test (PET) was performed 4 weeks later. The peritoneal function and net ultrafiltration (UF) volume were determined. The level of malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) in peritoneal tissue were examined. The histology of peritoneal membrane was evaluated by light microscopy. E-cadherin and α-smooth muscle actin (α-SMA) protein expression was evaluated by immunohistochemical method and Western blot.Results The mesothelial cells were detached from peritoneal membrane in peritoneal firbosis rats. Comparing with the control rats, the thickness of visceral peritoneum, the level of MDA, and the-SMA protein expression were increased while the net ultrafiltration volume, the level of GSH-Px and E-cadherin protein expression were decreased in peritoneal firbosis rats. All these changes were reversed in the rats treated with probucol.Conclusion Oxidative stress plays an important role in transdifferentiation of peritoneal mesothelial cell in the peritoneal fibrosis rats. Probucol can improve structure and function of peritoneum, and partially reverse the EMT by reducing the oxidative stress.