BACKGROUND:It is not fuly understood that whetherp53 inhibitor can directly intervene in the viability of bone marrow mesenchymal stem cels and the possible mechanism. OBJECTIVE:To investigate the effect of p53 inhibitor, PFT-α, on the aging process of bone marrow mesenchymal stem cels in late-phase amplification and to discover the key target to delay the replicative senescence of human bone marrow mesenchymal stem cels. METHODS:The expression levels ofp53,p21, andp15 mRNA in human bone marrow mesenchymal stem cels in both early and late-phase amplification were detected by quantitative PCR assay. Then, human bone marrow mesenchymal stem cels in late-phase amplification were respectively treated with 20 μmol/L PFT-α or an equivalent amount of dimethyl sulfoxide for 2 weeks. The positive rate of aging cels was determined by SA-β-Gal staining. The apoptosis was detected by TUNEL staining. Human bone marrow mesenchymal stem cels were treated with 300 μmol/L H2O2 for 30 minutes, and then celular anti-oxidative stress capacity was detected by cel counting kit-8 assay. RESULTS AND CONCLUSION:The quantitative PCR assay showed that the mRNA expression level ofp15, p21 andp53 in human bone marrow mesenchymal stem cels in late-phase amplification was significantly increased (1.45±0.23), (1.51±0.14) and (1.78±0.14) times as much as that in early phase amplification (P < 0.05). The positive rate of aging cels in PFT-α group was significantly lower than that in the dimethyl sulfoxide group[(41±5)%vs. (63±7)%,P < 0.05)]. However, there was no significant difference in apoptosis rate between PFT-α group and dimethyl sulfoxide group. After treatment with H2O2, the absorbance value in the PFT-α group was(1.27±0.13) times as much as that in the dimethyl sulfoxide group (P < 0.001). The above results demonstrate that the activation ofp53 signaling pathway may be an important factor of causing aging of human bone marrow mesenchymal stem cels. Application ofp53 inhibitor PFT-αcan enhance the anti-oxidative stress capacity of human bone marrow mesenchymal stem cels in late phrase amplification.

BACKGROUND:The main way for long-segmental ureteral reconstruction may cause a lot of traumas and complications. Therefore, to seek a new repair method is urgent. OBJECTIVE:To investigate the feasibility of a tissue-engineered tubular graft for ureteral reconstruction. METHODS:Bone marrow mesenchymal stem cels and smooth muscle cels of rabbits were seeded into the two surfaces of bladder acelular matrix and cultivated for 7 days. Then the graft was used to prepare a 4-cm long tissue-engineered tubular graft, which was regarded as experimental group. Smooth muscle cels seeded onto the bladder acelular matrix was used to construct the tissue-engineered tubular graft as control group. Twenty-five New Zealand rabbits were randomly divided into experimental group (n=20) and control group (n=5), and two kinds of tubular grafts covered with omentum were implanted into the two groups, respectively, for repair of ureteral defects. Hematoxylin-eosin staining and immunohistochemical detection were performed at 2, 4, 8 weeks after implantation. RESULTS AND CONCLUSION:In the experimental group, hematoxylin-eosin staining showed epithelial coverage and muscle fibers on the lumen of tissue-engineered tubular grafts at 8 weeks after implantation; immunohistochemistry showed that anti-AE1/AE3 antibody and anti-uroplakinⅢa antibody were positive, confirming that there were mature epithelial cels on the lumen of tissue-engineered tubular grafts. In the control group, five rabbits were dead within 2 weeks after removal of ureteral scaffold, and autopsy showed scar formation inside the graft and severe hydronephrosis. These results demonstrate that it is feasible to construct the tissue-engineered tubular graft using bone marrow mesenchymal stem cels and smooth muscle cels into the bladder acelular matrix for ureteral reconstruction. Bone marrow mesenchymal stem cels can potentialy promote urothelial regeneration.

High-speed counter-current chromatographic ( HSCCC ) method was successfully used to separate and purify prim-O-glucosylcimifugin and 5-0-methylvisammioside from Saposhnikovia divaricata(Thicz. ) Schis-chk. ,a traditional Chinese herb,with a solvent system composed of ethyl acetate-n-butanol-water(2:7:9,V/V). The lower phase of the system was used as the mobile phase at the flow rate of 2.0 mL/min,and the upper phase was used as the stationary phase. The separation produced a total 13.9 mg prim-O-glucosylcimifugin and 25.0 mg 5-0-methylvisammioside with the purity of 98. 1% and 99.2% determined by high performance liquid chromatography (HPLC) from 316 mg of crude sample from S. divaricata. The structures of isolated compounds were identified by ESI-MS,~1H NMR and ~(13)C NMR.

BACKGROUND:Urothelial cells are important seeding cells for urinary tissue engineering, but they are difficult to proliferate in vitro. Several studies have shown that bone marrow mesenchymal stem cells can differentiate into urothelial cells, but how these cells functions in vivo in epithelium generation after implantation, and the application of these cells in tissue engineering, are rarely studied. OBJECTIVE:To explore the isolation and proliferation of rabbit bone marrow mesenchymal stem cells that are induced into urothelial cells in combination with rabbit bladder acellular matrix to construct tissue-engineered grafts, and to assess the effect of the induced cells as seeding cells. METHODS:Twelve 8-week-old male New Zealand white rabbits were chosen to obtain bone marrow samples through tibia puncture, and to isolate bone marrow mesenchymal stem cells by density gradient centrifugation. Then the fourth or fifth generation of bone marrow mesenchymal stem cells were cultured in conditioned medium for 2 weeks, and then identified by PCR and immunofluorescence. After that, the induced cells were seeded on rabbit bladder acellular matrix to construct tissue-engineered grafts for bladder repairing. Another 12 rabbits served as control group, and urothelial cells combined with bladder acellular matrix was used for bladder repairing. RESULTS AND CONCLUSION:Bone marrow mesenchymal stem cells were successful y cultured and proliferated in vitro. After induction, PCR detection suggested that stem cellmarker (CD44) expression decreased, and epithelial cellmarker (UP1a) expression increased in the induced cells. Immunofluorescence staining demonstrated that the induced cells rather than bone marrow mesenchymal stem cells were positive for specific urothelial marker, UP1a. A stable continuous epithelial layer was observed on tissue-engineered grafts constructed by induced cells after 2 weeks, similar to the grafts built by urothelial cells. Induced bone marrow mesenchymal stem cells can differentiate into urothelial cells that can be used as seeding cells for urinary tissue engineering, which may be another choice out of urothelial cells.

BACKGROUND:Cationic liposome-mediated celltransfection is reliable and repeatable. However the transfection efficiency is often low.
OBJECTIVE:To study the optimized methods for gene transfection mediated by liposome into N2a cells (mouse neuroblastma cells).
METHODS:Using traditional adherent method and improved suspension method, 500 ng recombinant plasmid pcDNA3-GFP carrying green fluorescence protein was transfected into N2a cells in 24-wel culture plate, which was mediated by 1.5μL Lipofectamine?LTX Reagent. The expression of green fluorescent protein was observed by inverted fluorescence microscope, and the transfection efficiencies at different transfection ways were calculated. By using improved suspension transfection method, 500 ng plasmid DNA was transfected with different doses of Lipofectamine?LTX Reagent (1.0, 1.5, 2.0, 2.5μL). The optimal ratio of liposome and DNA was explored.
RESULTS AND CONCLUSION:The transfection efficiency of suspension transfection method was significantly higher than that of the tranditional adherent method (P<0.01) when using 1.5μL liposome/500 ng DNA. The transfection efficiency of the 1.0, 1.5, 2.0, 2.5μL Lipofectamine?LTX on 500 ng plasmid DNA was respectively (76.60±3.85)%, (80.00±4.17)%, (88.00±5.89)%, (54.96±4.23)%. It showed the 500 ng DNA and 2.0μL liposome achieve the highest transfection efficiency.

Objective To analyze the safety and effectiveness of ambulatory surgery in inguinal herniorraphy.Methods The clinical data of 3 852 cases of inguinal hernia repair patients admitted from January 2009 to December 2013 in this single center was analyzed retrospectively.Cases of emergency surgery were excluded.Results All patients had long-term follow-up (12-60 months).1 575 patients underwent day-surgery,mean operation time was (43.84 ± 12.35) min,mean time of ambulation was (1.12 ± 0.91) d,mean time of recovery was (5.78 ± 1.12) d,mean hospitalization was (1.34 ± 0.48) d,mean hospitalization cost was (7 546.49 ±2 962.57) RMB.In contrast,there were 511 patients underwent a non day-surgery,mean operation time was (48.59 ± 14.52) min,mean time of ambulation was (2.43 ± 1.38) d,mean time of recovery was (7.46 ± 2.62) d,mean hospitalization was (4.8 ± 2.91) d,mean hospitalization cost was (9 165.16 ± 4 281.83) RMB.Patients with day-surgery were significantly superior to those with non day-surgery in operation time (P =0.000),mean time of ambulation (P =0.000),mean hospitalization (9 =0.000),mean hospitalization cost (P =0.000) and mean time of recovery (P =0.000).Infection and readmission in non day-surgery patients was higher than that in day-surgery (P =0.000).There was no difference in postoperation pain and hernia recurrence.Conclusions Ambulatory surgery in inguinal herniorraphy is safe with similar recurrence rate;but significantly lower cost and shorter hospitalization.

AIM:To investigate the effect of 18 alpha-glycyrrhetinic acid (18α-GA) on delaying the senescent progress and promoting the proliferation in late-passage bone marrow mesenchymal stem cells ( BMSCs ) .METHODS:Late-passage BMSCs were incubated with 2.0 mg /L 18α-GA or the same volume of DMSO for 30 d, and the cells were harvested to determine the proteasome activity .The expression of senescence-related proteins p53, p21 and p16 was detec-ted by senescence-associated β-galactosidase ( SA-β-Gal) staining and Western blot .The cell proliferation , the expression level of cell cycle-related proteins and cell cycle distribution of the cells were measured by CCK -8 assay, BrdU incorpora-tion, Western blot and flow cytometry.RESULTS:Compared with DMSO group, the proteasome activity in 18α-GA group increased significantly by about 0.2 times (P<0.01).SA-β-Gal-positive cells in 18α-GA group decreased, and cell stai-ning was lighter.The contents of p53 and p21 in 18α-GA group were decreased (P<0.05).The results of CCK-8 assay showed that the A value in 18α-GA group was 0.3 times higher than that in DMSO group (P<0.01).BrdU incorporation showed the increased proliferation in 18α-GA group compared with DMSO group ( P<0.05).The cells in G1 phase in 18α-GA group decreased significantly compared with DMSO group , while the cells in S phase increased significantly ( P<0.05).The expression level of cyclin D1 in 18α-GA group was 2.8 times higher than that in DMSO group (P<0.01), and the CDK4 level was 1.4 times higher than that in DMSO group (P<0.05).CONCLUSION:Activation of the pro-teasome activity by 18α-GA delays the aging process in the BMSCs and promotes the cell proliferation via up -regulation of the cell cycle-related proteins .

BACKGROUND:Up to date,there is not an acceptable method for isolating,culture and amplifying human adipose-derived mesenchymal stem cells (hADSCs).OBJECTIVE:To explore the most effective way to obtain highly homogenous and undifferentiated hADSCs.DESIGN,TIME AND SETTING:The in vitro cytology experiment was performed at the Key Laboratory of Pathobiology,Ministry of Education,Jilin University from June to December 2008.MATERIALS:Human abdominal adipose tissue resected in the surgery was supplied by the Affiliated Hospital of Jilin University,The informed consent was obtained from patients.METHODS:Human adipose tissue was removed connective tissue and blood vessel,followed by incubation in 0.1% type I collagenase for 60 minutes at 37℃,filtrated then centrifuged.Consequently,the subnatant precipitation was cultured with LG-DMEM containing 10% fetal bovine serum,incubated at 6-well plate with density of 1×10~9/L,and placed in incubator of 5% CO_2 at 37 ℃.The cultured cells were passaged when the cells reached 80%-90% confiuency,and the 3~(rd) passage of cells were induced to osteogenic and adipogenic differentiation.MAIN OUTCOME MEASURES:Morphological characteristics of hADSCs were observed by laser scanning confocal microscope.Immunophenotypes,cell cycle and growth curve of hADSCs were detected by flow cytometry and immunofiuorescent techniques.In addition,the multiple differentiation potential of hADSCs was detected.RESULTS:hADSCs presented fibroblast-like morphological feature with a flocked array.The 3~(rd) passage of hADSCs had unique immunophenotypes and they were positive for CD73,CD44,CD166,CD105 and CD29,but negative for CD31,CD34,CD45 and HLA-DR.Cell cycle result showed that they had the typical growth characteristics of stem calls,namely,83.81% cells stayed at G_0/G_1 stage,only 16.19% cells were stayed at S+G_2/M stage;The latent phase of the primary culture cells was 2 days prior to and after incubation,followed by 3-6 days of logarithmical proliferation,reached a peak at day 6,and entering the growth platform phase with lower growth speed.The alkaline phosphatase was positive expressed at week 2 of osteogenic induction.And the positive expression of oil-O red staining could be seen at day 3 of adipogenic induction.CONCLUSION:Cells contamination can be reduced by removing connective tissue and blood vessel of adipose tissue,and 0.1% type Ⅰ collagenase for 60 minutes can effective separated stroma cell to matrix fiber,furthermore,ensure a sufficient contact between collagenase and tissures,which provide an supportive for harvesting highly homogenous hADSCs.

Objective To assess the effect of hybrid debranching technique in treatment of patients with traumatic aortic arch rupture combined with pseudoaneurysm.Methods Clinical data of 3 patients with traumatic aortic arch rupture combined with pseudoaneurysm repaired using debranching technique from June 2011 to June 2013 were analyzed to determine their clinical features and treatment options.Hypersound or computed tomography angiography (CTA) was performed to confirm the therapeutic effects at postoperative 1 week,3,6,and 12 months as well as annually thereafter.Results All patients underwent operation uneventfully.Operation time was 6.8-10.5 hours (mean,7.6 hours) and intraoperative blood loss was 250-450 ml (mean,310 ml).Length of stay was 26-45 days (mean,32 days).There were no deaths at the 0.5-2 years of follow-up.Hypersound or CTA revealed no leakage of contrast medium after operation.Conclusion Hybrid debranching technique greatly reduces surgical trauma and provides satisfactory outcome and good function recovery.

Objective To establish a long-term culture system for mouse spermatogonial stem cells(SSCs). Methods Testis cells from 4-6 days postpartum male transgenic BALB/C mice were collected by a modified two-step enzymatic digestion method.After three differential adherence selections,the enriched germ cells were finally suspended in StemPro-34 SFM medium supplemented with other nutrients factors and plated on mouse embryonic fibroblast(MEF)feeder layer.20 ng/ml Glial cell line-derived neurotrophic factor,10 ng/ml basic fibroblast growth factor and 200 ng/ml GDNF-family receptor al were added to the serum-free medium to promote SSCs proliferation.Aduh male BALB/C mice,4-5 weeks old,underwent intraperitoneal injection of 40 mg/kg busulfan as recipient mice.Cultured SSCs were also injected into the seminiferous tubules of the left recipient testis through micromanipulator and right testis as self-control.Testes of recipient mice were observed by a fluorescence stereomicroscope and HE stains at 2 months after transplantation. Results By improved digestion method,the vitality of isolated testis cells was more than 98%and the stem cells was enriched about 18.5 fold. 1-2 days after transferred to MEF feeder, the round germ cells started to proliferate and had the shape of paired or aligned undifferentiated spermatogonia connected by cytoplasmic bridges. After 3-4 days, SSCs proliferated continuously and formed typical colonies. SSCs from BALB/c mice could be cultured and passaged in a steady state for 3 months. Cryostat section through the transplanted testis showed that most of seminiferous tubules were filled with germ cells expressing EGFP.HE staining further showed clearly that seminiferous tubules contained complete spermatogenesis.Conclusions SSCs from BALB/c mice could be cultured in an improved culture system for 3 months.The culture system could facilitate understanding the regulatory mechanism that governs SSCs and might provide an opportunity for the cure of infertility.