BACKGROUND: The implanted cartilage calls can synthesize cartilage matrix as cartilage in cartilage tissue enginsedng, and the density of implanted cells is the key point.OBJECTIVE: To evaluate the effect of cell seeding concentration on the chondrogenic differentiation of the adipose dadved sromal cells (ADSCs).DESIGN, TIME AND SETTING: The in vitro cellular-scaffold observation was performed at the cytobiological laboratory of China Medical University from November 2007 to July 2008.MATERIALS: Six male SD rata with clean grade were supplied by the Experimental Animal Center of China Medical University.METHODS: Totally 5 g/L type ; collagen solution and 20 g/L chitosan was mixed in a mould with volume ratio of 7:3, after lyophillization, it was cut into pieces with 5 mm ～ 5 mm x 2 mm, followed by crosslinking with ethanol contained of 2% chondroitic acid at room temperature. After washing with double distilled water and freeze drying, the chitosan-collagen-chondroitin sulfate copolymar matrices scaffolds were harvested. ADSCs isolated from rat inguinal fat pads were digested with collagenase and trypsase. The prepared scaffolds were randomly divided into 3 groups, and the third passage cells with density of 2×10 9/L,2×10 109/L, and 2×10 11/L were seeded into chitosan-coflagen-chondroitin sulfate scaffolds, and cultured in chondrogenic medium for 3 weeks.MAIN OUTCOME MEASURES: The expression of cartilage specificity gene was detected by hematoxylin-eosin staining, type Ⅱ collagen immunohistochemical staining and RT-PCR.RESULTS: Hematoxylin-eosin staining showed that after 3 weeks of culture, the cell proliferated and differentiated well, especially in 2x101～/L group, more extrocelluer matrices were produced and cartilage lacuna-structure could be seen. The type Ⅱ collagen was positive expressed in each group, which showed a gradually increasing tendency with the cell seeding concentration increasing. RT-PCR showed that the expression of proteoglycen and type Ⅱ collagen mRNA were slowly increased. However the expression of Ⅹ collagen mRNA was decreased with increasing cell seeding concentration.CONCLUSION: The chitosan-collagen-chondroitin sulfate copolymer matrices can provide an appropdate environment for the generation of cartilage-like tissues and high call seeding concentration of 2×1010/L facilitate ADSCs to differentiate into cartilage.

Objective To evaluate the character of the collagen-chitosan-chondroitin sulfate scaffold seeded with rat adipose tissue-derived stromal cells. Methods A dipose tissue were harvested from 6 weeks old Wistar rats and the stromal cells were harvested by type Ⅰ collagenase and then cultured in vitro. Type Ⅰ collagen was fully mixed with chitosan, freeze-dried and cross-linked with chondroitin sulfate, then freeze-dried again and sterilized by ethylene oxide. The pore diameter, water content, porosity of the scaffold were tested. The adipose tissue-derived stromal cells were digested, seeded into the plates, scaffold, and cen-trifuged into pellet, and then induced into cartilage. MTT detection for cell proliferation was done. After 3 weeks, the cell morphology, and cell proliferation and adhesion were observed, and chondrngenic differenti-ation was also analyzed. Results The pore diameter, water content, porosity tested for the scaffold showed an appropriate form. Cell proliferation showed faster in the scaffold and pellet culture system after 5 day, there was still cell proliferation in the scaffold system after 14 days but no obvious changes in the pellet cul-ture system; ceils on the scaffold proliferated densely showed by histological staining, but there was a scaf-fold structure residues in the inner layer. The finding of type Ⅱ immunohistochemistry stain showed that cells express strong positive for type Ⅱ collagen in the scaffold and pellet culture system whereas it was weakly positive in the plate culture system; the specific mRNA for cartilage, type Ⅱ collagen, aggrecan and SOX-9 were expressed in all three systems showed by RT-PCR, but type X collagen was expressed continu-ously in the plate culture system and expressed after 21 days in the pellet culture system, whereas it was not detected in the collagen-chitosan-chondroitin sulfate scaffold system. Conclusion The parameters of the collagen-chitosan-chondroitin sulfate scaffold were suitable in our study. The results suggested that it can promote the adipose tissue-derived stromal cells proliferation and chondrogenic differentiation better than the plate and pellet culture systems and maintain the phenotype of chondrocytes well; it is the optimal choice for cartilage tissue engineering in the future.

Objective To investigate the correlation between 8 single nucleotide polymorphisms(SNPs) of FOXO3A gene and human longevity in Bama county.Methods Genotyping of FOXO3A gene was performed by TaqMan-PCR technique for 177 longevous peolpe(aged 90-110) from Bama longevity area and 148 healthy controls(aged 48-89) from Bama non-longevity area.Results Minor allele frequencies of 5 known FOXO3A SNPs(rs2764264,rs9400239,rs13217795,rs2802288 and rs2802292)in cases were significantly higher than those in controls(P5%).Frequency of haplotype 'AG'in cases was significantly higher than that in controls,and frequency of haplotype 'TTTGTC'in cases was significantly lower than that in controls(P

Objective To investigate the role of Heme oxygenase-1 in the effect of hyperbaric oxygen preconditioning (HBOP) against the brain edema formation after experimental intracerebral hemorrhage in rats.Methods The study was carried out by animal experiment in two steps by using 54 Spradgue-Dawley rats weighting from 300-350 g.In the first step,rats were treated with HBOP (HBOP group,n =3) or with sham pre-conditioning (Sham pre-conditioning group,n =3).All the rats were sacrificed 24 h after the preconditioning,and basal ganglion of brain tissue was taken for detect HO-1 level by using western blot analysis.In the second step,rats were divided into 4 groups (n =12 in each group):HBOP +ZnPP group,in which rats had a micro-pump intra-peritoneally implanted containing a specific HO-1 inhibitor ZnPPⅨ (Zinc protoporphyrin IX,0.01 mg/kg),Sham pre-conditioning + Znpp group,HBOP + DMSO group,in which rats with a intra-peritoneal micro-pump containing 2 mL Dimethyl sulfoxide (DMSO,a solvent vehicle) and Sham pre-conditioning + DMSO group before HBOP.At 24 hours after the pre-conditioning,rats received an infusion of 100 μL autologous blood into the caudate nucleus to form a simulated intracerebrum hemorrhage (ICH),and were sacrificed 72 h later for brain water content measurements.All data were analyzed by using Stata 7.0 software and statistical analyses were carried out by two-tailed Student t test.Results Compared with the Sham pre-conditioning group,the HBOP group had significant higher level of HO-1.Compared with the Sham pre-conditioning + DMSO group,the HBOP + DMSO group had a significant lower level of water content in the ipsilateral basal ganglion [(81.4 ± 0.9) ％ vs.(82.6 ± 0.8) ％ (P ＜ 0.05)],however,peritoneal infusion of ZnPP Ⅸ before HBOP abolished HBOP-induced protection against brain edema formation after experimental ICH [(82.8 ± 0.9) ％ vs.(82.6 ± 0.7) ％ (P ＞ 0.05)].Conclusions Hyperbaric oxygen preconditioning attenuate brain edema formation after experimental ICH in rats,and this protection is attributed to the activation of HO-1.

Objective To explore the relationship between DLG value and planning dose distribution and actual treatment dose distribution.Methods IMRT and VMAT plans were generated in Eclipse TPS for a typical whole pelvis case,separately.For IMRT plan,MLC position and actual fluence were calculated for each DLG value with the same optimal fluence.Plans with different DLGs of 0 cm and 0.3 cm were compared by several dosimetric indexes.For exploring the PTV mean dose difference between planning dose and actual IMRT or VMAT treatment,planning dose was recalculated with fixed MLC position and different DLGs.Results Dosimetric differences of PTV V50,rectum V40,bladder V40,small bowel V35,left and right femoral head Dmax were 1.49％,0.72％,0.82％,0.68％,0.02 and 0.14 Gy respectively,the average leaf pair width of MLC segments was correlated with DLG (R2 =0.996,P ＜0.05) and reduced with the increase of DLG.In actual treatment,3.95％ and 1.5％ mean dose reduction in PTV were observed while DLG increased per 0.1 cm in the typical pelvis case,in IMRT and VMAT treatment respectively.Conclusions DLG can result in the change of MLC position and the dose difference between planning and actual treatment.

Objective To study the changes of mesenteric arterioles on the contractile response to norepinephrine in patients with cirrhosis and portal hypertension (PHT) caused by hepatitis B after treatment by high-dose vitamin C.Methods Eleven PHT patients and 6 non-PHT volunteer were those undergoing their respective surgeriesat in our hospital from January 2010 to June 2011.The PHT patients were randomly assigned to vitamin C treatment group and placebo treatment group.After admission and before induction of anesthesia,blood taken to mesure plasma concentration of malonaldehyde (MDA).Intraoperative portal pressure was measured.We took the third level intestinal mesentery vessels with their mesentery next to the jejunum and studied the contractile response to norepinephrine of the intestinal mesenteric arterioles.We also measured RhoA/ROCK pathway associated proteins' expression and activity changes by Western-blot method.Results The average value of the plasma MDA of PHT patients with cirrhosis was much higher than that of non-PHT patients.After treatment by vitamin C,the value decreased.The dose-response curve of isolated mesenteric arterioles to norepinephrine from PHT patients with cirrhosis shifted to the right,and the EC50 value was higher than that of non-PHT patients.But this phenomenon was reversed after the patients treated with vitamin C.The protein expression of RhoA in mesenteric arteries did not change significantly among the three groups.But the protein expression and activity of ROCK-1 was significantly reduced in PHT patients with cirrhosis.After treatment with vitamin C,the expression and activity of ROCK-1 in mesenteric arteries of cirrhosis was significantly increased.Conclusion The PHT patients with cirrhosis are in the situation of oxidative stress.The high-dose vitamin C treatment can reduce oxidative stress level and improve contractile hyporeactivity of mesenteric arterioles of PHT patients with cirrhosis to norepinephrine.The protein expression and activity increasement of ROCK in RhoA/ ROCK pathway is involved in thisphenomenon.

Objective To investigate the effects of hyperbaric oxygen preconditioning (HBOP) on brain edema, inflammatory reaction and neuronal cell apoptosis induced by experimental hemorrhage in rats. Method Eighteen male Spraque-Dawley rats, weighing 300 - 350 g,received five successive sessions of HBOP with 3 atmosphere absolute pressure and 100% O2 one hour daily for five successive days, and other eighteen rats received five successive sessions of pretreatment with one atmosphere absolute pressure, air, one hour daily for five successive days. Twenty-four hours after the final pre-conditioning, rats received an infusion of 100 μL autologous blood into the basal ganglion. Seventy-two hours later, rats were sacrificed for brain edema measurements in 12 rats of each group. The histopathological changes around the hematoma were observed microscopically, and the neuronal cell apoptosis was detected by using the terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) in six rats of each group. Data of brain water content were analyzed by using Stata 7.0 software and statistical analysis was carried out by two-tailed Student t -test. Results Compared with the control group, HBOP significantly attenuated brain edema 72 hours after intra-cerebral hemorrhage in experimental rats (81. 6± 0. 7% vs. 82. 8± 0.9%, P < 0.01). Inflammatory cell infiltration and neuronal cell apoptosis were also significantly decreased in the HBOP group. Conclusions HBOP protects the rats against brain edema formation, and quells inflammatory reaction and neuronal cell apoptosis following intra-cerebral hemorrhage in experimental rats.

The conventional therapy for arteriosclerosis obliterans (ASO) is Western medicine. However, it has some adverse effects and does not respond to some patients, and it is also very expensive.

Objective To investigate the antitumor effect of tumor necrosis factor-related apoptosis-inducing ligand(TRAIL) gene transfection mediated by adenovirus into human pancreatic carcinoma cell line Panc-1,and the mechanisms involved in this effect.Methods TRAIL gene was transfected into pancreatic cancer cell line Panc-1 by an adenovirus vector(Ad-TRAIL).Level of TRAIL mRNA expression was determined using RT-PCR,and TRAIL protein synthesis was evaluated with Western blot.Cell-growth activities were determined by MTT assay.The bystander effect was observed by co-culturing the Panc-1 cells with and without the transfected TRAIL gene at different ratios.Apoptosis in pancreatic cancer cells was detected by flow cytometry.Proaspase-8 and procaspase-3 proteins were determined by Western blot.Results The stable overexpression of TRAIL was detected in Panc-1 cells transfected by Ad-TRAIL.Ad-TRAIL significantly inhibited cell viability of Panc-1 cells.Furthermore,co-culture of cancer cells transfected with TRAIL resulted in the nontransfected cell inhibition by bystander effect.Moreover,the percentage of apoptotic cells was significantly higher in the Ad-TRAIL-treatment group compared to the control groups(P

In recent years,medical colleges have generally accepted the higher education assessment(evaluation).How to put the good practices and experience we obtained during the educational assessment into the daily teaching management and achieve normalization of teaching evaluation is of great significance to continuously improving the teaching quality.It is the primary condition to establish the evaluation index system for evaluating clinical teaching quality by regular teaching assessment. In this paper,the author constructed a clinical teaching quality evaluation index system through systematic research and exploration.