Cancer stem cells are defined as the unique subpopulation in the tumors that possess the abili-ty to initiate tumor growth and sustain self-renewal as well as metastatic potential.Accumulating evidences in recent years strongly indicate the existence of cancer stem cells in solid tumors of a wide variety of organs.In recent years,many cancer stem cells have been found,including leukemia,breast cancer,brain ttunor,liv-er cancer,colon carcinoma,etc.In this review,we will discuss the conception and origin of the gastric cancer stem cells,and their role in the development of multi-drug resistance.

Objective To study the effects of Tongqiao-Huoxue decoction on neuron apoptosis in the CA1 region of the hippocampus and the serum nidogen expression of vascular dementia(VaD) rats and to investigate its mechanism. Methods 40 healthy male SD rats were randomly divided into a normal group, a sham operation group, a model group, a TCM group, and a placebo group. VaD rat models were established by Olsson method. After the models were successfully prepared, the rats in the TCM group were fed Tongqiao-Huoxue decoction, the rats in the placebo group were fed distilled water. Morris water maze test was adopted to investigate their learning and memory abilities, TUNEL was used to assay hippocampal CA1 neurons apoptosis, ELISA kits was used to detect Nestin serum levels . Results The neuron apoptosis index in the CA1 region of the hippocampus in the TCM group was(37.01±2.23)%,which was(55.15±1.54)%in the placebo group;the difference was statistically significant(P<0.05).The serum nidogen was(4.47±0.31)ng/L in the TCM group, which was(3.42±0.43)ng/L in the placebo group;the difference was statistically significant(P<0.05). Compared to the VaD group, escape latency in the TCM group in the third, forth, and fifth day was significantly shorter(P<0.05), the number of cross platforms were significantly increased(t=3.521, P=0.000). Conclusion Tong qiao-Huoxue decoction can improve learning and memory impairment in VaD rats, which may be associated with its increasing serum nidogen expression and decreasing the neuron apoptosis in hippocampal CA1.

Objective:To observe the effects of dentin proseeded with BMSCs or PDLCs incorporated with PDLCs sheets and calci-nated ceramic bovine bone(CBB)in the reconstruction of periodontal tissue.Methods:Root dentin slices were prepared and pre-seeded with BMSCs or PDLCs from beagle dog.After cultivated in osteoinduction medium(OST groups)orα-modified eagle's medi-um(MEM groups)for 3 weeks,the dentin slices observed by scanning electron microscope (SEM).Then the slices were wrapped successively with PDLCs sheets and CBB as new constructs(BMSCs or PDLCs/dentin/PDLCs sheets/CBB).The new constructs were transplanted into nude mice subcutaneously,8 week after transplantation,samples were havested and examined by HE staining.Re-sults:Enough cells and extracellular matrices were detected on the dentin slices by SEM in vitro.A little new immature cementum-like tissue without periodontal-like tissue on the surface of the new construcs was observed in OST groups.By contrast,in MEM groups,periodontal-like without immature cementum-like tissue formation was observed.Conclusion:Dentin proseeded with BMSCs or PDLCs incorporated with PDLCs sheets and CBB cultured by MEM can promote periodontal-like tissue regeneration.Cultured with osteooinduction medium can promote cementum-like tissue regeneration.

砄bjective: To investigate the effect of calcitonin gene related peptide(CGRP) on calcification function of human dental pulp cells(HDPCs) in vitro . Methods: HDPCs cells were exposed to calcitonin gene related peptide at the dosages(mol/L) of 10 -12 , 10 -10 and 10 -8 for 3,6,9, 12 and 15 days respectively. Cell growth was studied by cell counting , alkaline phosphatase(AL) by a AL kit, osteocalin by immunoradiological tecnique and type I collagen mRNA expression by RT PCR. Results: CGRP did not show any effect on the growth of HDPCs, but it increased the expression of AL, osteocalin and type I collagen mRNA in HDPCs in a dose dependent and not time dependent manner. Conclusion: CGRP plays an important role in promoting differentiation and calcification function of HDPCs

AIM: To study the role of acylation stimula ting protein (ASP) in the differentiation of 3T3-F442A preadipocytes. METHODS: Differentiation of 3T3-F442A preadipocytes was induced by ASP. The morphological changes were observed by Oil-Red O staining and the di fferentiation rate was compared. TG synthesis and TG mass in these cells were al so assayed. DNA synthesis was measured by -TdR incorporation. A typical differentiation inducer, insulin, was used as a positive control to compare thes e results. RESULTS: (1) 3T3-F442A preadipocytes were induced to differentia te by ASP alone. Fat droplets were clearly visible in the cytoplasm of 3T3-F442A cells. The differentiation rate was high (90%), but no significant difference w as observed, compared with that in insulin group (95%). (2) In ASP group, TG syn thesis and TG mass were significantly increased, both of them were higher than t hat in control group (P0.05). CONCLUSION: As a new adipocytes hormone, ASP plays an important biological role in the differentiation of preadipocytes.

Objective To explore the influence of lung IL-10 on interstitial dendritic cells in multiple organ dysfunction syndrome(MODS),and its role in immunological dysfunction.Methods The model of MODS was replicated by injecting zymosan into the peritoneal cavity of C57BL/6 mice.The mice were then randomly divided into normal groups as well as the groups of 3-6 hours,12-48 hours,5-7 days and 10-12 days post trauma.The level of CCR7 mRNA in lung was detected by RT-PCR and the proteins of CCR7 and IL-10 were immunohistochemically stained.The number of mononuclear cells in MHC-II positive peripheral blood was determined by flow cytometry.Results At the early stage of injury(3-6 hours),the number of IL-10 positive cells and the expression of CCR7 increased,but the number of mononuclear cells in MHC-II positive peripheral blood decreased.At the stage of 12-48 hours,the number of IL-10 positive cells and the expression of CCR7 continued to increase obviously,and that of mononuclear cells in MHC-II positive peripheral blood went on decreasing.At the stage of 10-12 days,the number of IL-10 positive cells increased dramatically compared with that in normal group,but the expression of CCR7 declined obviously in contrast to that in 12-48 hours,and the number of mononuclear cells in MHC-II positive peripheral blood decreased to the lowest level.Conclusions The expression of IL-10 in lung could inhibit the excessive immunological damage induced by dendritic cells on the one hand,and it probably leads to immunosuppression by reducing the CCR7 expression of dendritic cells and the number of mononuclear cells in MHC-II positive peripheral blood on the other hand.

The fourth generation poly( amidoamine) dendrimers ( G4. 0 PAMAM) functionalized multiwalled carbon nanotube ( G4 . 0-MWCNTs ) was prepared by amidation between carboxylated multiwalled carbon nanotube (MWCNTs) and G4. 0 PAMAM. Then a novel hydrogen peroxide (H2O2) sensor was fabricated by electrodepositing Pd nanoparticles (NPs) on a glassy carbon electrode (GCE) modified with G4. 0-MWCNTs composites. The modified electrode was characterized by field emission scanning electron microscopy ( FESEM) , cyclic voltammetry ( CV) and electrochemical impedance spectroscopy ( EIS) . A large amounts of highly dispersion PdNPs could be well loaded on the surface of the G4. 0-MWCNTs, and the modified electrode exhibited excellent electrocatalytic activity towards the reduction of H2 O2 . Under the optimized conditions, the reduction peak currents of H2 O2 were linear to their concentrations in the range from 1. 0 × 10-9 mol/L to 1. 0×10-3 mol/L and the limit of detection of 2. 3×10-8 mol/L was obtained. The recovery of standard addition for human serum samples was 96 . 7%-103 . 1%.

Animal experiment on influenza virus infection carries certain biohazard risk, with a threat to the health of researchers and public health.The risk levels differ by influenza virus types and subtypes.This article combs the domestic and national laws and rules, and explores the biosafety management of animal study on influenza virus.

This paper proposes algorithm in predicting the RNA secondary structure that combines several sequence comparisons, searches the eigenvalue for subsequence division with dynamic programing, utilizing the minimum free energy method. Moreover, the paper assesses the results derived from this new algorithm based on base-pairs distance, climbing distance and morphology distance. The paper also compares the assessment result and the prediction results of different prediction tools, and analyzes the advantages of the new method and its improvement direction.
Algorithms ; Nucleic Acid Conformation ; RNA ; chemistry

Pancreatic cancer is a highly malignant neoplasm with dismal prognosis. The risk of recurrence and metastasis remains high even for patients who have undergone radical dissection. Therefore, adjuvant therapy after "curative" resection is crucial. However, consensus on the optimal management of pancreatic cancer after surgery has not been reached. Both chemotherapy and concurrent chemoradiation therapy have been advocated. Yet, based upon the results of published phase Ⅲ trials, the consensus and standard strategy of adjuvant treatment after pancreatic cancer surgery is still undo" debate. According to the results of GITSG and RTOG trials, the mainstream in North American is adjuvant chemoradiation. However, based on the results of ESPAC-1 and CONKO-001 studies, the oncologists in Europe usually recommend chemotherapy alone. Furthermore, the superiority of gemcitabine over 5-FU in the adjuvant setting is largely unclear. This article reviewed the main results of the clinical trials in the field of adjuvant treatment of pancreatic cancer.From the authors' view, both the standard dosage of gemcitabine (CONCO-001) and chemoradiation (RTOG-9704) after resection of pancreatic cancer could be considered as candidates for adjuvant strategy. However, the optimal therapy will have to be determined by trials with larger number of patients.