BACKGROUND:Adipose-derived stem cels are a kind of mesenchyam stem cels with multipotent differentiation capacity, which have more advantages than bone marrow mesenchymal stem cels in tissue engineering research. OBJECTIVE: To establish a method to isolate and purify adipose-derived stem cels from human subcutaneous adipose tissues folowed byin vitro amplification and osteoblastic/adipogenic differentiation.
METHODS: Adipose-derived stem cels were isolated from human subcutaneous adipose tissue and cultured by density gradient centrifugation and adherent culture. Cel morphology and growth features were observed under inverted microscope. Adipose-derived stem cels at passages 2 and 5 were selected for viability measurement using cel counting kit-8 method, and then cel growth curves were drawn. The immunophenotype identification was analyzed by flow cytometry. Passage 5 cels underwent osteoblastic/adipogenic induction to confirm the multi-differentiation potential.
RESULTS AND CONCLUSION: (1) Using density gradient centrifugation and adherent culture method, high-purity human adipose-derived stem cels can be successfuly isolated from human adipose tissues. (2) The growth process of human adipose-derived stem cels includes stagnant phase, logarithmic phase and plateau phase, which meets the growth rhythm of normal cels. Moreover, the population doubling time is shorter. (3). Human adipose-derived stem cels are positive for stem cel-related antigens, with low immunogenicity and the multi-differentiation potential. (4) Labeling human adipose-derived stem cels with DAPI is a simple efficient labeled method, and the labeling rate is high but the cytotoxicity is low

OBJECTIVE To realize the circumstances of the antibiotic application during perioperational period and evaluate the rational application of antimicrobial agents in department of gastrointestinal Surgery in a hospital.METHODS Retrospective study for 210 patients in the department of gastrointestinal Surgery form Jan 2007 to Dec 2008 was carried out randomly.RESULTS The antibacterial agents were used in all patients during perioperation.The antibacterial agents used most frequently were Metronidazole and Cephalosporins,The combined use cases accounted for 90.5%.The average period of treatment was 7 days.The incidence of surgical site infection was 8.6%.Only 55.6% patient′s samples were examined and drug susceptibility test were detected.CONCLUSIONS The irrational applications of prophylactic antibiotitcs during the perioperative period are serious,such as the average time of using antibiotics was too long,unreasonable frequently sort changing and low rate for samples detecting.

ObjectiveTo investigate the impact of metal plate on radiation dose distribution by Monte Carlo (MC) code. MethodsThe metal plates with 0. 4 thick were placed in water at 5 cm, all the plate irradiated with 6 MV X-ray were simulated by MC code, SSD =100 cm. The percentage depth dose with or without metal implants were compared. ResultsThe surface absorbed doses on incident plane of stainless steel plate and titanium plate were increased by 19. 6％ and 15.7％ respectively as compared water,the dose influence was less than 1.5％ more than 0. 3 cm outside the incidence plane. The doses on the exit surface of stainless steel plate and titanium plate were lowered by 8. 6％ and 8. 2％ when compared with water, the dose impacts of this places where were from the exit surface of stainless steel plate 、titanium plate more than 1.2 cm,0. 9 cm were less than 1.5％. The surface absorbed doses on incident plane of stainless steel plate were increased by 3.9％ respectively as titanium plate, the dose of the exit surface of stainless steel plate and titanium plate was similar. Conclusions MC method is a fast and accurate calculation method. The influence of metal plate on the radiotherapy dose distribution is significant. Under the such condition, the impact of stainless steel plate is much more than that of titanium alloy plate.