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Objective To evaluate the effect of dexmedetomidine on endoplasmic reticulum stress during intestinal ischemia-reperfusion (I/R) in mice.Methods Thirty SPF healthy male C57BL/6 mice,aged 8 weeks,were divided into 3 groups (n=10 each) using a random number table method:sham operation group (S group),intestinal I/R group (I/R group) and dexmedetomidine group (DEX group).The superior mesenteric artery was only isolated but not clamped in S group.The model of intestinal I/R injury was established by clamping superior mesenteric artery for 20 min followed by 24 h of reperfusion in I/R group and DEX group.Dexmedetomidine 25 μg/kg was intraperitoneally injected at 30 min before ischemia in DEX group,while the equal volume of normal saline was given instead of dexmedetomidine in S group and I/R group.Mice were sacrificed at 24 h of reperfusion,and small intestinal tissues was obtained for examination of the pathological changes and ultrastructure of intestinal epithelial cells and for determination of cell apoptosis,expression of CCAAT-enhancer binding protein homologous protein (CHOP),transcription factors (ATF4),and X-4 box binding protein 1 (XBP1) mRNA (by real-time polymerase chain reaction),and expression of CHOP,Bcl-2,Bax and caspase-3 in intestinal tissues (by Western bolt).The apoptosis index (AI) and ratio of Bcl-2 to Bax were calculated.Intestinal damage was assessed and scored according to Chiu.Results Compared with S group,Chiu's score and AI were significantly increased,the expression of CHOP,ATF4 and XBP-1 mRNA,CHOP,Bax and caspase-3 was up-regulated,and the expression of Bcl-2 was down-regulated,and Bcl-2/Bax ratio was decreased in I/R group and DEX group (P＜0.05).Compared with I/R group,Chiu's score and AI were significantly decreased,the expression of CHOP,ATF4 and XBP-1 mRNA,CHOP,Bax and caspase-3 was down-regulated,and the expression of Bcl-2 was up-regulated,and Bcl-2/Bax ratio was increased in DEX group (P＜0.05).Conclusion The mechanism by which dexmedetomidine reduces intestinal I/R injury may be related to regulating endoplasmic reticulum stress and inhibiting cell apoptosis in mice.
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BACKGROUND:Human hypoxia-inducible factor-1 alpha can regulate the expression of osteogenic and angiogenic genes, and promote osteogenic activity. OBJECTIVE:To observe the expression of osteogenic genes in rat bone marrow mesenchymal stem cells carrying human hypoxia-inducible factor-1 alpha slow virus infection. METHODS:Hypoxia-inducible factor-1 alpha was obtained from Hela cells using RT-PCR. Lentivirus expression vector plasmid carrying hypoxia-inducible factor-1 alpha (Lenti-HIF-1α-eGFP) was constructed. 293Ta cells with LentiPac HIV mixed packaging plasmid was packaged, and then lentivirus was obtained. Rat bone marrow mesenchymal stem cells were isolated and cultured using direct whole bone marrow adherent method. Bone marrow mesenchymal stem cells were identified using flow cytometry. Bone marrow mesenchymal stem cells were infected with slow virus for 1, 4, 7 and 14 days. Bone morphogenetic protein-2, osteocalcin, osteopontin and alkaline phosphatase expression levels were detected in bone marrow mesenchymal stem cells using real-time fluorescent quantitative PCR. RESULTS AND CONCLUSION:Bone marrow mesenchymal stem cells were effectively infected with Lenti-HIF-1α-eGFP. Real-time fluorescent quantitative PCR results revealed that bone morphogenetic protein-2, osteocalcin, osteopontin and alkaline phosphatase began to obviously overexpress from 4 days after infection with Lenti-HIF-1α-eGFP until 14 days. Results suggested that hypoxia-inducible factor-1 alpha could elevate the osteogenic activity of bone marrow mesenchymal stem cells.
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Objective To evaluate the relationship between the concentration of pentane in the exhaled air and degree of the lung injury in non-heart-beating (NHB) rabbits.Methods Twenty-four healthy male Japanese white rabbits weighing 2.4-3.0 kg were randomly divided into 4 groups ( n =6 each):A,B,C and D groups.The NHB model was established by exsanguination through the femoral artery.The exhaled gases were collected and lung tissues were removed at 0,30,60 and 120 min after cardiac arrest in A,B,C and D groups respectively.The concentration of pentane in the exhaled gases was detected immediately using the gas chromatography-mass spectrography.The wet to dry (W/D) lung weight ratio and content of malondialdehyde (MDA) in lung tissues were measured.The lung injury score (LIS) was recorded.The maximal volume ( Vmax ) of the lung was recorded when the airway pressure reached 30 cm H2O.Results Compared with groups A and B,the exhaled pentane concentration was significantly increased in group C,and the W/D ratio,content of MDA and LIS were significantly increased,while Vmax was significantly decreased in group D ( P ＜ 0.05).Compared with group C,W/D ratio and LIS were significantly increased in group D ( P ＜ 0.05 ).Conclusion The concentration of exhaled pentane can not reflect the degree of the lung injury in NHB rabbits.
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Objective To evaluate the anti-tumor effects of chemotherapeutic drugs on human gastric cancer cells. Methods From April 2006 to February 2007, 84 patients with gastric cancer underwent surgical resection at General Hospital of Jinan Military Command. The single-cell suspension of these gastric tumors was prepared. The gastric cancer cells were cultured with hydroxycamptothecin, cisplatin, adriamycin, 5-fluorouracil and mitomycin for 48 hours, and changes in activity of the gastric cancer cells were studied via MTT assay. The expression of survivin and PTEN was detected by immunohistochemistry. Data were analyzed by chi-square test, rank sum test and Fisher exact test. Results The anti-tumor effects of different chemotherapeutic drugs were different, and the poorly-differentiated gastric cancer cells were more sensitive to the cytotoxic effects of chemotherapeutic drugs than the well-differentiated gastric cancer cells. The expression levels of survivin in the signet ring cell carcinoma, mucinous adenocarcinoma and other poorly-differentiated adenocarcinoma were significantly higher than those in papillary carcinoma and tubular carcinoma (χ~2 = 10.625, P <0.05), while the expression of PTEN was inverse to that of survivin (χ~2 = 6.060, P < 0.05). The expression of survivin was related to the resistance of the gastric cancer cells to 5-fluorouracil and adriamycin (χ~2 = 6.609, 6.350, P < 0.05). Conclusions In vitro chemosensitivity assay is helpful in selecting the chemotherapeutic regimen for specific types of gastric cancer. Survivin may contribute to the chemotherapy-resistance of certain types of gastric cancer cells, and its expression is related to that of PTEN.
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Objective To study the correlation between chemotherapy drug sensitivity and the expression of P-glycoprotein protein(P-gp),lung resistant-related protein(LRP)in different esophageal carcinoma patients,which will offer experimental evidence for clinical individualized chemotherapy of esophageal carcinoma patients.Methods Selected fresh esophageal carcinoma's tissue,Common used drugs and chemoscheme for esophageal carcinoma were used for chemosensitivity testing of the primary cultured tumor cells.At the same time,immunohistochemistry method was used to detect the expression of P-gp and LRP of esophageal carcinoma cells.Results The chemotherapy drug sensitivity of single drug was different(P＜0.05).The combination of Tax and DDP had the best effect.DDP and NVB combination had a better effect than DDP and 5-FU combination.The sensitivity of DDP had no significant correlations with expression intensity of P-gp(P＞0.05),and it had significant correlation with expression intensity of LRP(P＜0.05).There were significant correlations between sensitivity of both NVB group and Tax group and expression intensity of P-gp and LRP(P＜0.05).There was no significant correlations between sensitivity of 5-FU and expression intensity of P-gp and LRP(P＞0.05).Conclusion The esophageal carcinoma chemosensitivity in vitro can indicate the sensitive drug of different patients,and guide individualized chemotherapy.The expression of P-gp and LRP has relationship with several chemotherapy drugs,which can provide base for individualized chemotherapy in clinic.
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OBJECTIVE@#To study the expressions of Cyclin D1 and p16 proteins in hypopharyngeal squamous cell carcinoma and their clinical significance.@*METHOD@#Immunohistochemical technology (P-V) was applied to detect the expression of Cyclin D1 and p16 in 36 cases of hypopharyngeal squamous cell carcinoma and 10 cases of normal epithelium.@*RESULT@#(1) The expression of cyclin D1 in the tumorous cell was significantly higher than that in normal epithelium (P 0.05); (3) There was correlation between the expression of Cyclin D1 and the expression of p16 (r(s) = -0.420, P < 0.05).@*CONCLUSION@#The over-expression of Cyclin D1 and the under-expression of p16 may play a significant role in the occurrence incidence and development of hypopharyngeal squamous cell carcinoma, and may be important indicators for cervical lymph node metastases.