Objective To investigate the reversing effects on drug resistance of gastric carcinoma by suppressing PI3K/PKB signal pathway,and explore its implicated mechanism.Methods MTT assay was used to test the inhibitory effects of VCR alone or VCR in combination with PI3K/PKB inhibitor,LY294002 on SGC7901/VCR cells.The SGC7901 treated with or without LY294002 served as control.The protein levels of PKB and phospho-PKB in the above VCR cells were determined by Western blot analysis.The mRNA expressions of MDR1,Bax and Bcl-2 were evaluated by semi-quantitative PCR with ?-actin as the inner control.The apoptosis was detected by flow cytometry.Tumor volume on the tumor-bearing mice transplanted by SGC7901/VCR cells or cells treated by VCR,LY294002 and their combination respectively was measure for the in vivo effect of LY294002.Results LY294002 enhanced the sensitivities of SGC7901/VCR cells to VCR significantly,and promoted the apoptosis rate induced by VCR prominently,with their corresponding drug resistant index decreasing from 40.45 to 8.50.The protein level of phospho-PKB was reduced,and the mRNA expression levels of MDR1 and Bcl-2 were inhibited(P

Objective To observe the influence of Lycium Barbarum polysaccharide(LBP) on FasL expression in H22-bearing mice and to explore its anti-tumor mechanism.Methods Kunming mice were randomized into the model group,and low-and high-dose LBP(in the dose of 0.625 and 1.250 g?kg-1?d-1 respectively) groups.H22-bearing mice models were induced through right subaxillary inoculation of H22-ascitic cells.Three days after inoculation,LBP group were given LBP for 14 days.Hematoxylin and eosin(HE) staining method was used to examine the tumor cell density,tumor cell mitotic count,and lymphocyte infiltration in tumor interstitial tissue.FasL expression was observed in the three groups with immunohistochemical method.Results Tumor cell mitotic count was decreased in the two LBP groups(P

The pharmacokinetics and tissue distributions of the novel paclitaxel microemulsion based on the L-OH lipid complex made in our laboratory were studied in this article with the commercial paclitaxel injection in cremophor as reference preparation by injected intravenously with single dose of 5 mg x kg(-1) in rats. LC-MS/MS method was used to determine the drug concentration in plasma and calculate the pharmacokinetic parameters. [3H]-paclitaxel was used to reveal the tissue distributions of different organs in 0.5 h, 3 h, 24 h and 120 h. The results indicated that the AUC of the emulsion group descended to 42.55%, with the CLz and Vz increased by 2.27 times and 3.81 times respectively. Tissue distribution results revealed that the emulsion showed a significantly increase in liver and spleen with a peak concentration up to 5 times; a slightly increase was observed in lung with no statistical differences; a significantly decrease in heart, kidney, gastrointestinal tract, bone marrow, aorta, thymus, pancreas, fat, muscle, skin, seminal vesicle, reproductive organs and brain with a drop of 40%-80%. These results indicated that paclitaxel microemulsion based on L-OH lipid complexes can remarkably reduced the blood exposure, accelerate plasma clearance rate and increase distribution volume. The fact that paclitaxel microemulsion tended to be uptake by reticuloendothelial system (RES) contributed to the target in liver, spleen and lung, and help to reduce the toxicity in blood, heart, kidney and gastrointestinal tract.

Objective To explore the relationship of the expression level of monocyte Chemotactic protein-1 and nuclear factor κB(NF κB)with atrial fibrosis of atrial fibrillation patients with rheumatic heart disease.Methods About 200 mg right atrial tissue were taken from 26 patients with rheumatic heart disease undergoing valve replacement surgery and divided into sinus rhythm (SR) group (n=12) and atrial fibrillation (AF) group (n=14).Masson staining and atrial myocardial fibrosis markers were used to determine the level of fibrosis.The mRNA levels of cytokines in atrial tissue were measured by reverse transcription polymerase chain reaction (RT-PCR)The protein level of MCP-1 and phosphorylation of NFκB in atrial tissue were detected by Western blotting.Results Compared with SR group,the AF group showed that collagen volume fraction (AF:0.42 ± 0.03;SR:0.13 ± 0.02),the mRNA levels of myocardial fibrosis markers such as transforming growth factor (TGF)-β1,type Ⅰ collagen and type Ⅲ collagen,and cytokines such as IL-1β and TNF-α,and the protein level of MCP-1 (AF:0.170±0.003;SR:0.040±0.005) and level of phosphorylation of NF-κB (AF:0.35 ± 0.02;SR:0.12 ± 0.03) were significantly increased (all P＜0.05).In addition,the expression levels of cytokines,the protein expression level of MCP1 and the phosphorylation level of NF-κB were positively correlated with collagen volume fraction of the right atrial myocardial tissue (all P＜0.05).Conclusions Activation of NF-κB may induce the expression of MCP-1 in the myocardial tissue of patients with rheumatic heart disease,and sequentially stimulate the secretion of cytokines and extracellular matrix deposition,and finally participate in the occurrence and persistence of atrial fibrillation.

Objective To evaluate the relationship between the mechanism underlying docosahexaenoic acid (DHA)-induced regulation of angiopoietin expression and Src-suppressed C kinase substrate (SSeCKS) in human brain vascular pericytes (HBVPs) subjected to oxygen-glucose deprivation and restoration (OGD/R).Methods HBVPs were seeded in 96-well or in 6-well plates at a density of 2× 105 cells/ml and divided into 5 groups (n =18 each) using a random number table:control group (group C),OGD/R group,DHA group (group D),SSeCKS gene silencing group (group S) and SSeCKS gene silencing plus DHA group (group SD).The model of OGD/R injury was established as follows:the cells were subjected to O2-glucose deprivation for 24 h in glucose-and serum-free culture medium aerated with 94％ N2-5％ CO2-1％ O2 followed by restoration of O2-glucose supply for 6 h in high-glucose DMEM culture medium in normal atmosphere.DHA was added at 1 h before hypoxia with the final concentration of 40 μmol/L in group D.Small interfering RNA induced SSeCKS gene silencing in S and SD groups.Subsequently,DHA with the final concentration of 40 μmol/L was added at 1 h before hypoxia in group SD.At 6 h of reoxygenation,the cell survival rate was determined by CCK-8 assay,the amount of LDH released was detected using ELISA,and the expression of SSeCKS,angiopoietin-1 (Ang-1) and Ang-2 was detected by Western blot.Results Compared with group C,the cell survival rate was significantly decreased,the amount of LDH released was increased,the expression of SSeCKS and Ang-1 was down-regulated,the expression of Ang-2 was up-regulated,and Ang-1/Ang-2 ratio was decreased in group OGD/R,and the expression of SSeCKS was down-regulated in group S (P＜0.05).Compared with group OGD/R,the cell survival rate was significantly increased,the amount of LDH released was decreased,the expression of SSeCKS and Ang-1 was up-regulated,the expression of Ang-2 was down-regulated,and Ang-1/Ang-2 ratio was increased in group D (P＜O.05),and no significant change was found in the parameters mentioned above in group SD (P＞0.05).Compared with group D,the cell survival rate was significantly decreased,the amount of LDH released was increased,the expression of SSeCKS and Ang-1 was down-regulated,the expression of Ang-2 was up-regulated,and Ang-1/Ang-2 ratio was decreased in group SD (P＜0.05).Conclusion The mechanism by which DHA increases the ratio of Ang-1/Ang-2 may be totally related to up-regulation of SSeCKS expression in HBVPs subjected to OGD/R.

Objective To evaluate the effects of docosahexaenoic acid ( DHA) on the expression of angiotensin?2 ( Ang?2) and vascular endothelial growth factor ( VEGF) in rat brain microvascular endo?thelial cells (BMVECs) subjected to oxygen?glucose deprivation (OGD). Methods Primarily cultured rat BMVECs were divided into 3 groups ( n=18 each) using a random number table: control group ( group C) , OGD group and DHA group. The cells were cultured with glucose?free and serum?free DMEM culture medium in OGD and DHA groups. In group DHA, DHA 40μmol was added, and then the cells were ex?posed to 1%O2?5%CO2?94%N2 in an air?tight incubator. The cells were cultured in the normal glucose and normal oxygen conditions in group C. All the cells were cultured for 24 h. Cell apoptosis was detected using Annexin V∕propidium iodide flow cytometry assay, and the apoptosis rate was calculated. The concentra?tions of Ang?2, VEGF, prostaglandin E2 ( PGE2 ) and prostacyclin ( PGI2 ) in the supernatant of the cul?ture medium were determined by enzyme?linked immunosorbent assay. The expression of Ang?2 mRNA and VEGF mRNA in cells was detected by real?time polymerase chain reaction. The expression of cyclooxygen?ase?2 ( COX?2) protein in cells was detected by Western blot. Results Compared with group C, the ap?
optosis rate and concentrations of Ang?2, VEGF, PGE2 and PGI2 in the supernatant were significantly in?creased, and the expression of Ang?2 mRNA, VEGF mRNA and COX?2 protein was significantly up?regu?lated in OGD and DHA groups (P<0.05). Compared with group OGD, the apoptosis rate and concentra?tions of Ang?2, VEGF, PGE2 and PGI2 in the supernatant were significantly decreased, and the expression of Ang?2 mRNA, VEGF mRNA and COX?2 protein was significantly down?regulated in group DHA ( P<0.05) . Conclusion DHA can inhibit the expression of Ang?2 and VEGF in rat brain BMVECs subjected to OGD and reduce cell apoptosis, and down?regulated expression of COX?2 protein is involved in the mecha?nism.

Aim To observe whether the inhibition of PI3K/PKB signal pathway by LY294002[PI3K pathway inhibitor] could improve the sensitivities of human gastric carcinoma cell line SGC7901 and SGC7901/VCR to anti-cancer drugs.Methods The sensitivities of SGC7901 and SGC7901/VCR to chemotherapeutic drug VCR were detected by MTT.The MDR1 and XIAP mRNA expression levels were evaluated by semi-quantitative RT-PCR,and their protein levels were detected by immunocytochemistry.The PKB and phospho-PKB protein levels were detected by Western blot and the apoptosis ratio was detected by flow cytometry.Results 2?10-5mol?L-1LY294002 enhanced the sensitivities of SGC7901 and SGC7901/VCR cells to VCR(P

Objective To compare the image quality between volumetric high-resolution CT (VHRCT)and conventional high-resolution CT(CHRCT),and investigate the feasibility of VHRCT.Methotis Catphan 412 phantom was scanned with protocols of CHRCT and VHRCT on a set of GE Lightspeed VCE.The spatial-resolution(LP/cm),noise(standard deviation iu an ROI)and radiation dose (CTDI)were recorded for each CT scan.Difference of noise between CHRCT and VHRCT were evaluated by paired t test.In clinical study.32 patients were scanned with VHRCT and CHRCT protocols.The image quality of CHRCT and VHRCT was rated and compared.The quality difference between CHRCT and VHRCT was assessed by Wilcoxon paired signed rank sum test.Results In phantom study.the in-plane spatial-resolution of both VHRCT and CHRCT was 11 LP/cm for axial images and 12 LP/cm for coronal reformatted images.The noise of VHRCT and CHRCT was(69.18±2.77)HU and(54.62±2.12)HU respectively(t=-15.929.P＜0.01)at the same dose level.The radiation dose of VHRCT was 19.09 mGy higher than CHRCT at the same noise level.In clinical study.the quality assessment scores of VHRCT axial images and CHRCT axial images were 3.22 and 3.24 respectively.with no significant difference(Z=-0.319,P＞0.05).The qualily assessment scores of VHRCT coronal reformatted images and CHRCT coronal reformatted images were 3.05 and 1.88 respectively with significant difference(Z=-5.088.P＜0.01).Conclusion The image qualitv of VHRCT cross-sectional image is similar to that of CHRCT.Muhiplanar images with high resolution of VHRCT are recommended.The radiation dose of VHRCT remains to be optimized.

AIM: To explore the effect of deoxynivalenol on apoptosis and proliferation of mouse thymocytes in vivo. METHODS: Effect of deoxynivalenol at different concentrations on apoptosis and proliferation of mouse thymocytes in vivo were studied with animal experiment, electron microscopic observation, DNA agarose gel electrophoresis and flow cytometric analyses. RESULTS: FCM analysis showed that the apoptosis rates of the thymocytes in DON groups (0 5 mg/kg, 1 mg/kg, 2 mg/kg, 4 mg/kg and 8 mg/kg) were significantly higher than that in control ( P

This study examined the promoter methylation of APO-1/CD95 (Fas) gene in bladder urothelial carcinoma and analyzed the relationship between the Fas promoter methylation and the biological behavior of bladder cancer. Promoter methylation of Fas gene was detected by methylation-specific PCR (MSP) in 4 bladder cancer cell lines, 50 human bladder urothelial carcinoma samples and l0 normal bladder tissue samples. Correlation of the aberrant methylation of Fas promoter with the clinicopathological parameters was statistically analyzed. The results showed that Fas was down-regulated at both mRNA and protein level in bladder cancer cell lines and tissue samples of bladder urothelial carcinoma. The positive rate of Fas protein expression in bladder urothelial carcinoma was 34.0% (17/50), significantly lower than that in normal bladder tissues (70.0%, 7/10) (P<0.01). Fas promoter methylation was detected, and the positive rate of Fas promoter methylation in bladder urothelial carcinoma was 42.0% (21/50), which was obviously higher than that in normal bladder tissues (0.0%, 0/10) (P<0.01). The aberrant methylation of Fas promoter was reversely correlated with Fas protein expression (P<0.05). Furthermore, the positive rates of Fas promoter methylation in high-grade and low-grade bladder urothelial carcinoma were 73.3% (11/15) and 34.2% (12/35), respectively, with significant difference shown (P<0.05). No statistical significance was found in the Fas promoter methylation among different clinical stages of bladder cancer. It was concluded that Fas promoter hypermethylation plays an important role in the pathogenesis of bladder urothelial carcinoma and may serve as a prognostic indicator of bladder urothelial carcinoma.