Hair follicle stem cells located bulge region of hair follicle,had characteristics of all adult stem cells,including slow-cycling,undifferentiated.They also had the abilities of self-renew and proliferation in vitro.CD34,K15,K19 and Nestin might be the makers of the hair follicle stem cells.They could be induced to differentiate to neurons,glial cells,keratinocytes,smooth muscle cells,melanocytes In vitro and neurons,melanocytes in vivo.There were many signals in regulating the hair follicle stem cells involved Wnt signal,BM Psignal and NFATc1 etc.

AIM To study the effects of ASA on proliferation and apoptosis of human lung Adenocarcinoma cell lines SPCA-1 in vivo. METHODS Cytotoxicity assay was tested by MTT method.Cell cycle was analyzed by flow cytometry(FCM).The morphology of the treated cells was observed by wright exclusion,Hoechest/PI exclusion, electron microscope. Apoptosis landder was evaluated by agarose gel electrophoresis of DNA. RESULTS ASA inhibited SPCA-1 cell proliferation in a time-and dose-dependent fashion(1.0～12.5 mmol?L -1,24 h～72 h). ASA increased the number of cells in G 0/G 1 and G 2/M phases,degrased the population of S phases at on 24 h and incresed apoptosis cells number. CONCLUSION ASA may inhibit the proliferation of SPCA-1 cell lines through effects on cell cycle and apoptosis.

Objective: To investigate the effect of Helicobacter pylori (H. pylori)　on the synthesis of cyclooxygenase-1 (COX-1)　and cyclooxygenase-2 (COX-2) in gastric epithelial cells. Methods: a VacA(+) and CagA(+) international standard H. pylori line NCTC11637 and a human gastric epithelial carcinoma cell line BGC-823 were used. Western Blotting was applied to detect the synthesis of cyclooxygenase. Results: The content of COX-2 protein increased obviously after the cells were incubated with H. pylori sonicating extract for 1　h and the increase lasted for at least 6　h whereas the content of COX-1 protein did not change during the incubation with H. pylori extract. H. pylori lipopolysaccharide (LPS) had no effect on COX-2 synthesis. Conclusion: H. pylori stimulated the synthesis of COX-2 in BGC-823 cells and the effect was LPS-independent.

Activated sludge is a complicated microbial ecosystem that has diversity. Based on the diversity,microorganisms are selected by acclimation condition:the survival of the fittest,otherwise eliminate through selection or contest. Moreover,microorganisms in activated sludge acclimatize themselves to acclimation conditions. In the process the ecosystem distributes and adjusts microbial niche over again. The theory of "selection and acclimatization" may be used to explain the mechanism of activated sludge acclimation. So then,original sludge,wastewater quality and treating process are major influencing factors for activated sludge acclimation.

Nitrite oxidoreductase(NXR) is the key enzyme responsible for the oxidation of NO2-to NO3-in nitrite-oxidizing bacteria.Since NXR is a dissoluble enzyme,located at the inner side of the membranes of cells,its function is dependent on the electron transfer chain related to membranes.This paper reviews the advances in study on NXR,including the structure,catalysis mechanism and the impact of different factors.New techniques applied in recent studies and research prospects are also presented.

Objective To explore the clinical features and surgical management of aged patients with acute cholecystitis,and try to command the opportunity and procedure of laparoseopic cholecystectomy(LC)better.Meth- ods Clinical data of 52 aged cases with acute cholecystits undergone LC were analyzed retrospectively.Results All of the patients(within 48h of the acute attack)were successfully recovered without serious operative complications. Conclusion Aged acute cholecystitis progressed rapidly and its operative difficulty and risk were higher;only if more attention was paid to perioperative managements and operative time and technical skill were mastered,early LC for the patients was safe and feasible.Therefore.it should be recommended in the great majority of cases except the des- perate patients whose general condition was too poor to operate.

Objective:To investigate the association between p53 codon 72 polymorphism and the prognosis of breast cancer pa-tients receiving chemotherapy and radiotherapy after surgery. Methods:A total of 427 breast cancer patients treated with chemo-radio-therapy after surgery at Beijing Cancer Hospital were selected for this study. Polymerase chain reaction–restriction fragment length polymorphism was adopted to analyze the p53 codon 72 polymorphism. Survival analysis was conducted to compare the disparities of recurrence and survival among the patients with different p53 codon 72 polymorphic variants. Results:The distribution of three geno-types of p53 codon 72 in our cohort is as follows:Pro/Pro 18.3%(78/427), Pro/Arg 44.0%(188/427), and Arg/Arg 37.7%(161/427). No significant difference was observed among the local recurrence-free survival (LRFS), loco-regional recurrence-free survival (LR-RFS), distant disease-free survival (DDFS), and overall survival (OS) among the three genotypes (all P>0.05). Among the 303 estro-gen receptor (ER)-positive patients, OS was significantly better in patients with Arg/Arg genotype than those with Pro/Pro genotype (χ2=6.33, P=0.042). The multivariate analysis showed that the p53 codon 72 polymorphism is an independent factor of prognosis for LRFS, LRRFS, DDFS, and OS of ER-positive patients. For the ER positive patients with Pro/Pro genotype, the local recurrence, local-regional recurrence, distant metastasis, and mortality risks were 5.9 (HR=5.9, 95%CI 1.1-31.1, P=0.036), 3.1 (HR = 3.1, 95% CI 1.1-9.1, P=0.039), 2.8 (HR=2.8, 95% CI 1.3-6.0, P=0.010), and 4.0 (HR=4.0, 95% CI 1.3-12.0, P=0.013) times higher than those with Arg/Arg genotype, respectively. Conclusion:For ER-positive breast cancer patients who underwent surgery and chemo-radiotherapy, the local recurrence, loco-regional recurrence, distant metastasis, and mortality risk with Pro/Pro genotype are significantly higher compared to those with Arg/Arg genotype.

Objective To review the important points in the preoperative assessment and the surgical technique in precise hepatic pedicle dissection in anatomical hepatic segmentectomy.Methods 104 patients who underwent anatomical hepatic segmentectomy were divided into two groups according to the different surgical approaches adopted in a prospective and non-randomized manner:the precise hepatic pedicle dissection group (the precise group,n=44) and the conventional hepatectomy group (the conventional group,n=60).The perioperative and follow-up data were analyzed.Patients who had primary liver cancer,including hepatocellular carcinoma and intrahepatic cholangiocellular carcinoma,were analyzed separately.Results (1) There was no perioperative death in the two groups.There was no significant differences in blood loss and transfusion between the 2 groups of patients (P=0.069,0.208; t=1.844,1.266).There was a significantly higher rate of vascular inflow occlusion (P=0.001).There were significantly longer periods of vascular inflow occlusion and operative time (P=0.001,0.001; t=3.849,3.574) in the precise group.There was no significant difference in postoperative complications (P=0.988) and the duration of postoperative hospital stay (P=0.509;t=0.662) between the two groups.(2) In patients with primary liver cancer,there were no significant differences between the precise group (n=29) and the conventional group (n=41) in tumor margin positivity,vascular invasion and pathological staging (P=0.985,0.630,0.769).(3) All patients were followed up for two years.When compared with the conventional group,the disease-free survival (P=0.012),overall survival (P =0.006),and median survival (16.5 ± 4.5mo vs.7.8 ± 3.8mo)were significantly longer in the precise group.Conclusion Precise hepatic pedicle dissection had the same safety and efficacy as conventional method in partial hepatectomy.For primary liver cancer,precise hepatic pedicle dissection had better survival compared to the conventional method when the surgical margin was negative.

Objective To investigate the relationship of serum albumin and circulation function and the prognosis of septic children.Met-hods A retrospective study was carried out on 92 septic children.These children were divided into 2 groups by the level of serum albumin:hypoalbuminemia group(albumin

Objective To establish a lineage tracing method with Lgr5-EGFP-CreERT2/ROSA26-stop-EYFP mouse for observing the role of Lgr5⁺ intestinal stem cells in the renovation of small intestine tissue, and investigate the effects of radiation on the reconstruction of small intestinal stem cell tissue. Methods-Lgr5-EGFP-CreERT2/ROSA26-stop-EYFP mice were identified by genotype analysis. Tamoxifen was used to induce the expression of fluorescent protein in mice. The differentiation of intestinal stem cells induced by Tamoxifen was observed by laser confocal microscopy. Lgr5-EGFP-CreERT2/ROSA26-stop-EYFP mice were irradiated with⁶⁰Co γ-rays, and the effects of irradiation on the reconstruction of small intestinal stem cell tissue were examined. Results-Double positive mice were obtained by identification of Lgr5 gene (174bp) in DNA extraction from the mice tail with PCR method. In mice treated with single injection of Tamoxifen (100mg/kg), it was observed by laser confocal scanning microscopy that the Lgr5⁺ intestinal stem cells started dividing at the 5th day after inducement, reached the top of the villi at the 7th day, fluorescence appeared in a few of whole intestinal villi at the 14th day, and spread over more intestinal villi with dense fluorescence at the 45th day. However, in mice exposed to 15Gy irradiation, the intestinal villi fell off seriously without fluorescence in crypts. Conclusion-The lineage tracing model of intestinal stem cell has been successfully established and then used to evaluate the irradiation injuries to intestinal stem cells.