Background and purpose: More than 90% of cancer patients are incurable because of drug resistance. Activation of PI3K/Akt/mTOR signaling pathway in breast cancer, as a target for chemotherapy drugs has become a hot topic of breast cancer treatment. This study aimed to investigate the effect and mechanism of XCL1 on the proliferation of drug-resistant breast cancer cell, whether is related with the mTOR signaling pathway. Methods:Established gemcitabine-resistant breast cancer cell lines (MDA-MB-231/Gem). CCK8 to detect the proliferation of MDA-MB-231 and MDA-MB-231/Gem, RT-PCR and ELISA to determine the XCL1 expression level of the two cell lines, Western blot to detect the expression of mTOR. Results:Compared with MDA-MB-231, MDA-MB-231/Gem showed an enhanced proliferative capacity. The expression of XCL1 was increased in the resistant cell lines. Both of protein level and phosphorylation level of mTOR increased in drug-resistant cell lines. The MDA-MB-231 added exogenous XCL1 for 24 h, showed an enhanced cell proliferation. Adding anti-XCL1 antibodies in MDA-MB-231/Gem could reduce cell proliferation and treating MDA-MB-231/Gem with the mTOR inhibitor could also reduce cell proliferation, as well as the XCL1 expression level. Conclusion:XCL1 promotes the proliferation of drug-resistant breast cancer cells mediated by activation of the mTOR pathway.

Objective To assess the characteristics of heart rate turbulencer (HRT) in elderly patients with decreased left ventricular diastolie function.Methods 40 patients were divided into two groups:20 patients with enlarged left atrium and 20 patients without enlarged left atrium.20 healthy people were selected as controls. Turbu1ence onset (TO) and turbulence slope (TS) were measured,and correlation was analyzed between TO,TS and the E/A,index of Macruz and heart rate variability (HRV).Results TO was higher (P<0.05) and TS was lower in patients (P<0.01),TO was higber in patients with enlarged left atrium than in with out enlarged lef atrium people (P<0.05) and TS was lower (P<0.01).TO was positively (P<0.01) and TS Was negatively (P<0.05),correlated with the index of Macruz.TO Was negatively (P<0.05) and TS was positively (P<0.05) related to SDNN and SDANN.Conclusion HRT can be used as a potential risk predictor in decreased left ventricular diastolic function patients.

Objective To identify a detailed biological characterization of mesenchymal stem cells (MSCs) isolated from hu‐man umbilical cord(UC) tissue regarding their morphology ,immunophenotype ,purity and proliferative capacity and establish a rea‐sonably cultured and amplified system .Methods After stripping off arteries and veins ,the remaining parts of umbilical cord were cut into 1 mm3 small sections and cultured with DMEM/F12 containing 10% fetal bovine serum .Adhere cells were obtained and the morphology of the cells was observed under inverted phase contrast microscope .The growth curves of them were drawn by CCK‐8 and the cell cycle and surface antigens (CD29 ,CD73 ,CD90 ,CD105 ,CD31 ,CD14 ,CD34 ,CD45 ,CD11b ,HLA‐DR) were detected by flow cytometry .Results Seven to ten days after primary culture ,adhere cells came out of fragments .The MSCs harvested were a high purity and mainly presented as a fibroblast‐like morphology .UC‐MSCs had a strong ability of proliferation through the cell growth curve .The special surface antigens CD29 ,CD73 ,CD90 ,CD105 were positive expression ,while CD31 ,CD14 ,CD34 ,CD45 , CD11b ,HLA‐DR were negative .More than 80% cells of MSCs were found at G0/G1 phase .Conclusion Human UC‐MSCs could be cultured and proliferated in vitro .

Objective To approach the dynamic changes of CD~+_ 34 cells and T lymphocyte subsets and best time of peripheral blood stem cell harvest when using rHuG-CSF for peripheral blood stem cell mobilization in donors and patients.Methods From 2001 to 2002 12 donors and 16 patients in Lanzhou General Hospital who received chemotherapy 7 days ago were injected rHuG-CSF 300 ?g/d for mobilization peripheral blood stem cells,and flow cytometry were used to detect the changes of CD~+_ 34 cells and T lymphocyte subsets for 5 days.Results (1)Before using rHuG-CSF,there was obvious difference between patients and donors in bone marrow CD~+_ 34 cells(P

Objective To explore the dynamic changes of CD34 + cells and T lymphocyte subsets and best time of harvesting peripheral blood stem cell when G-CSF was used for peripheral blood stem cell mobilization in donors and patients. Methods A total of 12 donors and 16 patients who received chemotherapy for 7 d were injected G-CSF of 300 ?g/d to mobilize peripheral blood stem cells for 5 d and flow cytometry were used to detect the changes of CD34 + cells and T lymphocyte subsets everyday for 5 d. Results ① Before G-CSF treatment, there were obvious differences in bone marrow CD34 + cells between patients and donors (P

Objective To dynamically observe the changes of the plasma superoxide dismutase(SOD) activity and malondialde-hyde(MDA) content of rabbits with hemorrhagic shock in high latitude .Methods 28 rabbits were randomly divided into 4 groups :0 .9% NaCl group ,7 .5% NaCl group ,Voluven(6% HES 130/0 .4) group and control group .The plasma SOD activity and MDA content were measured before shock .At 30 minutes of shock and 30 minutes later of volumetric resuscitation .Then the changes of MAP were observed .Results There were no static difference among 4 groups in the levels of SOD and MDA before shock ;at 30 minutes of shock ,the SOD activity was reduced signicantly and the MDA content was increased in each group (P<0 .01) .Afer fluid infusion there were no obvious change in the plasma levels of SOD and MDA compared with those of shock in 0 .9% NaCl group and in 7 .5% NaCl group(P>0 .05) ,whereas in Voluven group ,compared with those in 0 .9% NaCl and 7 .5% NaCl group the SOD activity was elevated signicantly and the MDA content was decreased (P<0 .01) .Conclusion Voluven can be used in scan-venging oxygen free redicals by recovering the plasma SOD activity in rabbits with hemorrhagic shock in high latitude .

Objective To obtain the near-infrared fluorescence image in vivo and find the relationship between the detecting depth and fluorescence probe concentration. Methods Signals of fluorescence probe in various depths of vivo and tissue phantom with cooled CCD camera were acquired. Results The fluorescence intensity informations with different fluorescence probe concentrations and depths in vivo and liquid phantom were obtained. Conclusion Relationship between fluorescence intensity,location and depth of detecting probe in vivo is found. The linear relation of fluorescence probe concentration and detecting intensity is simulated,which will be used as a reference for the experiment system.

This research is for the purpose of comparative analysis of the microbial flora structure in the chilled beef with no packing and cling film, which under the same terms of sale. It was used the V3 area fragment of 16S rDNA to carry on PCR-DGGE, Meanwhile used the 16S rDNA sequence to analysis the microbial flora structure of the two samples, according to the technology of clone .The research discovered that the flora structure displays a biggish difference; there was 6 OTU in the chilled beef with cling film, mainly was that Lactococcus(28%), Lactobacillus (26%), Carnobacterium(18%) and Brochothrix (10%); but there was 18 OTU in the chilled beef with no packing, mainly was that Lactococcus(28%), Brchothrix(18%), Acinetobacter (11%). The result indicates that cling film played a certain inhibitory action regarding the Staphylococcus as well as the cold pole bacteria and such bacterium. And it can provide a certain theory ba-sis for the meat processing in the department of microorganism’s control.

It is used the method of pure culture,Selected 32 strains,which were obvious difference in the shape,color and so on common characteristic,From the chilled beef with no packing and cling film on sale in this research;and it was included 12 strains from the chilled beef sample packed with cling film;20 strains from the chilled beef sample with no packing.Simultaneously selected 4 strains which were predominant in each bacterium from the two samples to conduct the further research,8 strains serial numbers are:S01～S08,S01～S04 from the chilled beef sample with no packing;S05～S08 from the chilled beef sample packed with cling film.Through ARDRA(Amplified ribosomal DNA restriction analysis) as well as 16S rDNA to clarify the bacterium's classified status.The physiological and chemical tests were done to determine the various bacteria respective genus.The experiment indicated:S01 is Pseudomonas putida;S02 is Shewanella cincia stain;S03 and S05 are the same Shewanella putrefaciens;S04 is Stenotrophomonas mal-tophilia;S06 is Psychrobacter;S07 is Staphylococcus sciuri;S08 is Microbacterium-laevaniformans.It was proved that two samples altogether have the same predominant bacterium.It can provide certain theory basis for the chilled meat processing craft as the preliminary investigation in the cultured microorganism situation in two samples.

With the development of the food industry in China,it has been found that food safety is becoming the biggest issue in the food manufacture and logistics. Accurate and timely to establish a risk assessment method in produce market is the challenge for food safety system. Predictive microbiology is a core early warning technology in the food safety risk assessment. According to the microorganism predicting model,the pathogen and spoilage microorganism's growth in food can be fast judgment in advance. And it plays an important part in controlling the growth of pathogen and the spoilage microorganism in food. This paper summarized the predictive microbiology model's establishment and the present research situation,and discussed the present situation and application of predictive microbiology in food safety risk assessment. The future trend of predictive microbiology in food safety risk assessment was prospected as well.