ABSTRACT
Background and purpose:The study hasfound that tumornecrosis factor-related apoptosis inducing ligand (TRAIL) can enhance the cytotoxic effect of chemotherapeutic drugs on tumor cells. The aim of our study was to investigate the effects of the tumor TRAIL and cisplatin combined application on the growth and apoptosis of human ovarian cancer cell lines SKOV3 and OVCAR3, and the possible mechanism.Methods:Under the combined application of cisplatin and TRAIL, MTT method and flow cytometry were used to detect the proliferation and apoptosis of SKOV3 of OVCAR3 cells; the mRNA expression levels of death receptors, DR4 and DR5, were detected by real-time lfuorescent quantitative polymerase chain reaction (RTFQ-PCR). At the same time, the protein expression levels of DR4 and DR5 were detected by Western blot.Results:SKOV3 and OVCAR3 cells were sensitive to TRAIL protein, and with the increasing of TRAIL protein concentration, cell growth inhibitory rate up to 64%. When the combination application of TRAIL and cisplatin, the inhibition rate of the two cells reached more than 92%, and the two drugs showed high synergistic effect, compared with the single drug group (P<0.05). Flowcytometry analysis indicated that the synergistic killing effect of TRAIL and cisplatin was mainly due to the cell apoptosis. RTFQ-PCR and Western blot detection results showed that the DR4 and DR5 were up-regulated under the combined application of TRAIL and cisplatin.Conclusion:In vitro, TRAIL and cisplatin combined application can signiifcantly inhibit the proliferation of human ovarian cancer cells and induce tumor cell apoptosis. TRAIL can obviously enhance the sensitivity of cisplatin to tumor cells. The mechanism may be related to the increased death receptor DR4 and DR5 expression level.
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The epidemiological effects of native and mutated YMDD motif in the HBV genome under the selective pressure of lamivudine were investigated. YMDD wild and mutation motif in HBV genome were detected by flow through reverse dot blots (FT-RDB) with KaiPuTM DNA HybriMax Rapid Hybridization Machine based on the principle of "Flow-through hybridization" and by the traditional Reverse Dot Blot assay. Sera from 1021 suspected lamivudine-resistant chronic HBV carders after more than 8 months of lamivudine therapy and the corresponding archived sera were collected and assayed. We found 35.94% were single type infections with 8.03% YMDD, 7.93% YIDD and 19.98% YVDD. It was also found that 64.06% were mixed infections including 1.96% YMDD and YIDD, 51.62% YMDD and YVDD, 1.96% YIDD and YVDD, 8.52% YMDD, YIDD and YVDD. The levels of infections containing YVDD motif reached 82.08%. The pretreatment infectious status were: YMDD single infection was 36.93%; YIDD single infection was 6.07%; YVDD single infection was 17.04%; YMDD and YIDD mixed infection was 0.97%; YMDD and YVDD mixed infection was33.99%; YIDD and YVDD mixed infection was 0.98%; YMDD, YIDD and YVDD mixed infection was 4.02%. Infections containing YVDD motif were only 56.03%. The 34.32% mutation rate of YMDD motif to YVDD was significantly higher than the 10.97% of YMDD to YIDD (U=10.98, P<0.05), as estimated by Mann-Whitney U-test for non-parametric data. HBV containing YVDD motif might have an evolutionary ascendancy and become the dominant type under the selective pressure of lamivudine.
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Objective To investigate T-bet mRNA expression on peripheral blood mononuclear cells (PBMCs) and its relations with allergen specific IgE (SIgE), eosinophile cationic protein (ECP) levels, and allergic symptom in patients with allergic rhinitis (AR). Methods The allergen, SIgE, and ECP in serum of patients with AR were detected by Unicap CAP system. Blood samples were taken from 15 healthy controls and 35 house dust mite allergic patients. PBMC was isolated by density gradient centrifugation and one part of them was cultured with mite allergen at a concentration of 50 μg/mL. PBMC was subjected to analysis of T-bet mRNA expression using semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Results The ratio of T-bet to β-actin mRNA levels was 0.418 ± 0. 101 in patients of AR and 0.706 ± 0.091 in healthy controls and the difference was significant (P ＜ 0.01). The expression intensity of T-bet mRNA was not related to varying severity of allergic symptom and ECP levels ( r = - 0.227, - 0.033, P ＞ 0.05). However, there was an inverse correlation between expression intensity of T-bet mRNA and SIgE concentration (r = -0.375, P ＜ 0.05). There was a positive correlation between SIgE and allergic symptom scores ( r = 0.426, P ＜ 0.05). After that PBMC was stimulated by mite allergen, the expression intensity of T-bet mRNA, ECP, and SIgE changed very little ( P ＞ 0.05). Conclusion Down-regulated expression of T-bet mRNA in mite-AR patients is not related to serum ECP and symptom scores but one of important links in the mechanism of imbalance of Th1/Th2 in the occurrence of AR. Specific allergen has no effect on T-bet mRNA, ECP, and SIgE of children and adults with AR in vitro. The level of SIgE objectively and directly indicates the severity of allergic symptom, but T-bet did not. T-bet may be one of indirect factors which affect the level of IgE.
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Objective To develop a nested PCR for the detection of early syphilis and genotyping of Treponema pallidum (TP), and to investigate the distribution of genotypes of TP in Guangzhou. Methods Specimens were consecutively collected from genital ulcers of patients with suspected chancre during 2002-2004, and were detected by dark-field microscopy and nested PCR. The acidic repeat protein (arp) gene and the T. pallidum repeat (tpr) gene family were amplified with the positive specimens above. The number of repeats presented in the arp gene and the restriction fragment length polymorphism by Mse I in the tpr gene were analyzed by electrophoresis. The strains were genotyped according to Pillay's criteria. Results Out of 62 patients with suspected chancre, 33 cases (53.2%) were positive by dark-field microscopy and 54 cases (87.1%) by nested PCR. Of 47 TP-positive specimens genotyped by arp gene, 36 (76.6%) were type 14, while of 49 cases genotyped by tpr gene 39 (79.6%) were type d. By combining genotypes of arp and tpr genes, 7 genotypes were found, including 14d (31, 66.0%), 13d (5, 10.6%), 14b (4, 8.5%), 12b (3, 6.4%), 12d (2, 4.3%), 15d(l, 2.2%) and 14i (1, 2.2%). Conclusions Nested PCR shows a high sensitivity in early detection of TP. Genotype 14d seems the predominant type of TP in Guangzhou.