[Therapeutic and preventive activities of lamivudine on HBV re-activation in HBV carriers with immunodeficiency].
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Adult↗
Biomedical subjects
Yi Chen
Publications and source records attributed to Yi Chen.
[Management and prognosis of metastatic ovarian carcinoma from nongenital tract].
OBJECTIVE: To study the management and prognosis of nongenital metastatic ovarian carcinoma. METHODS: Thirty-four patients with nongenital metastatic ovarian carcinoma who were admitted in to Zhongnan Hospital of Wuhan University between 1998 and 2004 were analyzed retrospectively. RESULTS: The median survival time of group A (optimal cytoreductive surgery), group B (optimal cytoreductive surgery + chemotherapy), group C (sub-optimal cytoreductive surgery) and group D (sub-optimal cytoreductive surgery + chemotherapy) was 5.0, 10.0, 4.0 and 6.5 months, respectively. The difference was significant between groups A and B, B and C, as well as between group C and D (P < 0.05). CONCLUSIONS: Most of nongenital metastatic ovarian carcinomas come from tumors of stomach and intestine. Optimal cytoreductive surgery and chemotherapy play an important role in the management and prognosis of nongenital metastatic ovarian carcinoma.
Adult↗
[Separation of interleukin-18 on a weak anion exchange monolithic column].
A weak anion exchange column was prepared and a separation method of interleukin-18 (IL-18) was developed on the column. The chromatographic column with glycidyl methacrylate as functional monomer and ethylene dimethacrylate as cross-linker was prepared by a free radical polymerization within a 64 mm x 4.6 mm i.d. column. The epoxide groups of the column were modified by a reaction with diethylamine that affords ionizable functionalities required for ion exchange chromatography. The influences of the contents of the cross-linker and porogen on column pressure were investigated. The factors influencing the separation, such as stationary phases, buffers, pH values, salts, and contents of organic solvent, were studied. The optimal conditions for separating IL-18 from its related proteins were obtained. The proposed method is simple, sensitive, rapid and reproducible.
Anion Exchange Resins↗
[Separation and purification of proteins on monolithic anion-exchange columns].
A monolithic anion-exchange column with glycidyl methacrylate as the functional monomer and ethylene dimethacrylate as the cross linker was prepared by a free radical polymerization. The epoxide groups of the column were modified respectively by triethylamine, diethylamine and ethylenediamine that afforded anionic functionalities required for the anion-exchange chromatographic mode. The properties of the monolithic columns were investigated and the columns were successfully used as stationary phases of high performance liquid chromatography for the separation of proteins. For chromatographic analysis the effects of mobile phase composition and pH on the separation were investigated. The optimum separation for bovine serum albumin, lysozyme and glutathione was achieved with a gradient elution of mobile phase A (0.01 mol/L Tris-HCl (pH 7.0)) and mobile phase B (mobile phase A + 1.0 mol/L NaCl) with a flow rate of 1.0 mL/min at 25 degrees C. The optimum purification for cellulase enzyme was obtained with a gradient elution of mobile phase A (0.01 mol/L Tris-HCl (pH 7.1)) and mobile phase B (mobile phase A + 1.0 mol/L KBr) with the same flow rate and temperature. The columns exhibited good stability, and cellulase enzyme could be separated and purified quickly on the monolithic anion-exchange column modified by diethylamine.
Anion Exchange Resins↗
[Effects of xianggui pill on cytokine in endometriosis model rat].
OBJECTIVE: To study the adjustment of Xianggui pill on the cytokine of endometriosis model rat, and investigate the mechanism of Xianggui pill on the treatment of endometriosis. METHOD: To set up endometriosis model by rat self-endometria transplantation, drench sodium chloride, Xianggui pill elixation or Danazol after grouping, and to detect the contents of interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) by ELISA. RESULT: The contents of IL-8, TNF-alpha in the peripheral blood and peritoneal fluid of model group were higher than that of the blank group; The quality of allotopia growth intima tissue, the quantity of macrophage in peritoneal fluid and the contents of IL-8, TNF-alpha in the Xianggui pill group and Danazol group were all lower than those of the model group; but there was no significant difference of each target between the Xianggui pill group and Danazol group. CONCLUSION: Xianggui pill can restrain significantly the growth of allotopia intima tissue, and has apparently adjustment to the cytokine.
Animals↗
[Design and synthesis of quinoxaline derivatives and their antitumor activities].
AIM: To design and synthesize novel quinoxaline derivatives as antitumor agents. METHODS: Using 4-chloro-2-nitroaniline as a starting compound, followed by substitution, reductive cyclization, oxidation, and chlorination, to give the key intermediate 2,7-dichloroquinoxaline (7), which reacted with different phenolic compounds to afford quinoxaline derivatives. RESULTS: The structures of the target molecules were characterized by elemental analysis, 1H NMR, MS, and IR. CONCLUSION: At concentration of 1 x 10(-4) mol x L(-1), some of the derivatives showed equal antitumor activities to XK469.
Animals↗
[Synthesis, characterization and evaluation of octadecyl ester-bonded monolithic column].
An ester-bonded monolithic silica column for reversed-phase high performance liquid chromatography was synthesized by reacting stearic acid with gamma-glycidoxypropyltrimethoxysilane and coupling the intermediate product onto monolithic silica column. Characterization of the prepared column was carried out with Fourier transformation infrared spectrometry and elemental analysis. The chromatographic properties of the packing were evaluated by using benzene, biphenyl, and anthracene as samples and methanol-water as binary mobile phase. The column back-pressure and separation effect were also evaluated for fast separation. The results show that the stationary phase has satisfactory chromatographic properties and resists hydrolysis between pH = 2 - 8, and it can be used for the fast-separation of solutes efficiently.
Anthracenes↗
[Expression of cyclooxygenase-2, hMLH1 and hMSH2 proteins, and their relationship with microsatellite instability in gastric carcinoma].
OBJECTIVE: To investigate the expression of cyclooxygenase-2 (COX-2), human mut-l homologue 1 (hMLH1) and human mut-s homologue 2 (hMSH2) proteins in human paired gastric carcinoma (GC) and adjacent normal mucosa, and analyze their relationship with microsatellite instability (MSI). METHODS: The protein expressions were examined by western blotting. Five MSI loci were assessed by PCR. RESULTS: In 30 surgically excised GC tissues, the overexpression rate of COX-2, the low expression rate of hMLH1 and hMSH2 were 66.7%, 40% and 33.3%, respectively. Significant differences were found when compared with those of adjacent normal mucosa (P < 0.05). MSI was detected in 13 GC. The number of MSI-H (MSI-High, > or = 2 loci), MSI-L (MSI-Low, only one locus), and MSS (microsatellite stable) were 9, 4 and 17, respectively. The number of low expression rates of COX-2, hMLH1 and hMSH2 in MSI-H were 6, 8 and 5, respectively. There were significant differences compared to that of MSS (P < 0.05). CONCLUSION: The results suggest that microsatellite instability pathway is probably involved in the carcinogenesis of gastric carcinoma, which is frequently accompanied by low expression of hMLH1 and hMSH2, and may be also by low expression of COX-2.
Adaptor Proteins, Signal Transducing↗
[Fast separation of nicotinamide and nicotinic acid with molecularly imprinted monolithic column].
Nicotinamide has been employed as template for the preparation of molecularly imprinted monolithic polymer (MIP) which was used as liquid chromatographic stationary phase. It showed that the nicotinamide-MIP monolithic column was capable of recognizing the difference between nicotinamide and nicotinic acid, while the non-imprinted polymer had no such ability. The content of organic solvent, flow rate and pH of the mobile phase were investigated in the experiments. The following high performance liquid chromatographic conditions were selected: column, 50 mm x 4.6 mm i.d.; mobile phase, water; flow rate, 7.0 mL/min; experiment temperature, room temperature. The resolution between nicotinamide and nicotinic acid was 1.8. The results showed that the two compounds could be separated by the nicotinamide-MIP monolithic column. The column is very useful for the enrichment and detection of nicotinamide in body fluids.
Chromatography, High Pressure Liquid↗
HDR-192Ir intraluminal brachytherapy in treatment of malignant obstructive jaundice.
AIM: To determine the feasibility and safety of intraluminal brachytherapy in treatment of malignant obstructive jaundice (MOJ) and to evaluate the clinical effect of intraluminal brachytherapy on stent patency and patient survival. METHODS: Thirty-four patients with MOJ were included in this study. Having biliary stent placed, all patients were classified into intraluminal brachytherapy group (group A, n = 14) and control group (group B, n = 20) according to their own choice. Intraluminal brachytherapy regimen included: HDR-192Ir was used in the therapy, fractional doses of 4-7 Gy were given every 3-6 d for 3-4 times, and standard points were established at 0.5-1.0 cm. Some patients of both groups received transcatheter arterial chemoembolization (TACE) after stent placement. RESULTS: In group A, the success rate of intraluminal brachytherapy was 98.0%, RTOG grade 1 acute radiation morbidity occurred in 3 patients, RTOG/EORTC grade 1 late radiation morbidity occurred in 1 patient. Mean stent patency of group A (12.6 mo) was significantly longer than that of group B (8.3 mo) (P<0.05). There was no significant difference in the mean survival (9.4 mo vs 6.0 mo) between the two groups. CONCLUSION: HDR-192Ir intraluminal brachytherapy is a safe palliative therapy in treating MOJ, and it may prolong stent patency and has the potentiality of extending survival of patients with MOJ.
Aged↗
Fingerprinting of Salvia miltiorrhiza Bunge by non-aqueous capillary electrophoresis compared with high-speed counter-current chromatography.
The component of the traditional Chinese medicine (TCM) can be influenced by soil, climate, and growth stage, and fingerprint is an important means in its quality control. Our previous studies showed that high-speed counter-current chromatography (HSCCC) was helpful in the development of fingerprint of TCM. Since the HSCCC method is new, it is necessary to compare it with conventional ones, such as high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC) and high-performance capillary electrophoresis (HPCE). Comparison with HPLC was conducted in our previous study. In this study, HSCCC was compared with non-aqueous capillary electrophoresis (NACE). With NACE, seven stable components were separated within 55 min, respectively, from three crude samples of Salvia miltiorrhiza Bunge from different growth locations. In HSCCC separation, 12 components were separated, respectively, with good correspondence and precision within 13 h. Both NACE and HSCCC were effective in showing whole concentration distribution of all kinds of constituents. Principles of these two methods were very different, which led to different elution sequences and relative contents of peaks. HSCCC showed better performance in analysis of tanshinones, which made its fingerprint containing more chemical information than that of NACE. It was further proven that HSCCC could be a feasible and cost-effective method in the development of the fingerprint of TCM.
Countercurrent Distribution↗
Sol-gel-derived ceramic-carbon nanotube nanocomposite electrodes: tunable electrode dimension and potential electrochemical applications.
Nanocomposite electrodes made of sol-gel-derived ceramic-carbon nanotube are fabricated by doping mutliwalled carbon nanotubes (MWNTs) into a silicate gel matrix. The electrochemical behavior and potential electrochemical applications of the ceramic-carbon nanotube nanocomposite electrodes (CCNNEs) are also studied. The as-prepared CCNNEs exhibit a tunable dimension ranging from conventional electrode to nanoelectrode ensemble (NEE), depending on the amount of the MWNT dispersed in the silica sol and finally doped within the gel matrix. A high content of the MWNT (i.e., higher than 1.5 mg/mL in the sol) leads to the formation of the CCNNE characteristic of an electrode of conventional dimension, while a low content (typically lower than 0.10 mg/mL) essentially yields the CCNNE like a nanoelectrode ensemble. The NEE is demonstrated to possess good electrocatalytic activity toward the oxidation of ascorbic acid (AA), and the CCNNE of conventional dimension is found to possess remarkable electrocatalytic activity toward the oxidation of glutathione (both reduced and oxidized forms, GSH and GSSG). These properties of the CCNNEs essentially offer a new electrochemical approach for the detection of AA, GSH, and GSSG. The possible essence of the tailor-made dimensions of the CCNNEs is also presented and discussed.
Journal Article↗
Hematopoietic gene expression profile in zebrafish kidney marrow.
The zebrafish kidney marrow is considered to be the organ of definitive hematopoiesis, analogous to the mammalian bone marrow. We have sequenced 26,143 ESTs and isolated 304 cDNAs with putative full-length ORF from a zebrafish kidney marrow cDNA library. The ESTs formed 7,742 assemblies, representing both previously identified zebrafish ESTs (56%) and recently discovered zebrafish ESTs (44%). About 30% of these EST assemblies have orthologues in humans, including 1,282 disease-associated genes in the Online Mendelian Inheritance in Man (OMIM) database. Comparison of the effective and regulatory molecules related to erythroid functions across species suggests a good conservation from zebrafish to human. Interestingly, both embryonic and adult zebrafish globin genes showed higher homology to the human embryonic globin genes than to the human fetal/adult ones, consistent with evo-devo correlation hypothesis. In addition, conservation of a whole set of transcription factors involved in globin gene switch suggests the regulatory network for such remodeling mechanism existed before the divergence of the teleost and the ancestor of mammals. We also carried out whole-mount mRNA in situ hybridization assays for 493 cDNAs and identified 80 genes (16%) with tissue-specific expression during the first five days of zebrafish development. Twenty-six of these genes were specifically expressed in hematopoietic or vascular tissues, including three previously unidentified zebrafish genes: coro1a, nephrosin, and dab2. Our results indicate that conserved genetic programs regulate vertebrate hematopoiesis and vasculogenesis, and support the role of the zebrafish as an important animal model for studying both normal development and the molecular pathogenesis of human blood diseases.
Animals↗
Modest actomyosin energy conservation increases myocardial postischemic function.
We have proposed that pharmacological preconditioning, leading to PKC-epsilon activation, in hearts improves postischemic functional recovery through a decrease in actomyosin ATPase activity and subsequent ATP conservation. The purpose of the present study was to determine whether moderate PKC-independent decreases in actomyosin ATPase are sufficient to improve myocardial postischemic function. Rats were given propylthiouracil (PTU) for 8 days to induce a 25% increase in beta-myosin heavy chain with a 28% reduction in actomyosin ATPase activity. Recovery of postischemic left ventricular developed pressure (LVDP) was significantly higher in PTU-treated rat hearts subjected to 30 min of global ischemia than in control hearts: 57.9 +/- 6.2 vs. 32.6 +/- 5.1% of preischemic values. In addition, PTU-treated hearts exhibited a delayed onset of rigor contracture during ischemia and a higher global ATP content after ischemia. In the second part of our study, we demonstrated a lower maximal actomyosin ATPase and a higher global ATP content after ischemia in human troponin T (TnT) transgenic mouse hearts. In mouse hearts with and without a point mutation at F110I of human TnT, recovery of postischemic LVDP was 55.4 +/- 5.5 and 62.5 +/- 14.5% compared with 20.0 +/- 2.9% in nontransgenic mouse hearts after 35 min of global ischemia. These results are consistent with the hypothesis that moderate decreases in actomyosin ATPase activity result in net ATP conservation that is sufficient to improve postischemic contractile function.
Actomyosin↗
Reprogramming DNA-directed reactions on the basis of a DNA conformational change.
A strategy has been developed for switching chemical reactions between two identical reagents on the basis of DNA duplex-triplex transition. In response to the change of solution pH, a DNA complex changes its conformation and repositions chemical reagents that are conjugated with DNA strands. As a result, chemical reactions are reprogrammed. This strategy is expected to be applicable to sophisticated chemical syntheses.
Acylation↗
A DNA nanomachine based on a duplex-triplex transition.
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Base Sequence↗
Electrostatic layer-by-layer assembled carbon nanotube multilayer film and its electrocatalytic activity for O2 reduction.
Multilayer films of shortened multiwalled carbon nanotubes (MWNTs) are homogeneously and stably assembled on glassy carbon electrodes with the layer-by-layer (LBL) method, based on electrostatic interaction of positively charged poly(diallyldimethylammonium chloride) and negatively charged and shortened MWNTs. The film assembly and electrochemical property as well as the electrocatalytic activity toward O2 reduction of the MWNT multilayer film are studied. Scanning electron microscopy, the quartz crystal microbalance technique, ultraviolet-visible-near-infrared spectroscopy, and cyclic voltammetry are used for characterization of film assembly. Experimental results revealed that film growth is uniform, almost with the same coverage of the MWNTs in each layer, and that the assembled MWNTs are mainly in the form of small bundles or single tubes on the electrodes. Electrochemical studies indicate that the LBL assembled MWNT films possess a remarkable electrocatalytic activity toward O2 reduction in alkaline media. This property, combined with the well-dispersed, porous and conductive features of the MWNT film illustrated with the LBL method, suggests the potential application of the MWNT film for constructing an efficient alkaline air electrode for energy conversions.
Journal Article↗
Pseudolarix acid B inhibits angiogenesis by antagonizing the vascular endothelial growth factor-mediated anti-apoptotic effect.
Angiogenesis is controlled by a number of growth factors, including vascular endothelial growth factor (VEGF). In this study, pseudolarix acid B, isolated from the traditional Chinese medicinal plant Pseudolarix kaempferi and originally identified as an early pregnancy-terminating agent, was evaluated for its potential as an angiogenesis inhibitor, using in vitro and in vivo models. After exposure to pseudolarix acid B 0.625-5 microM for 72 h, the proliferation of human umbilical vein endothelial cells was significantly inhibited. Pseudolarix acid B 0.313-2.5 microM for 24 h potently blocked the VEGF-induced tube formation of human umbilical vein endothelial cells in a dose-dependent manner. Matrigel plug assays disclosed that pseudolarix acid B reduced angiogenesis induced by VEGF in vivo. In addition, pseudolarix acid B antagonized VEGF-mediated anti-apoptotic effects on serum-deprived human umbilical vein endothelial cells and increased apoptosis of endothelial cells induced by VEGF in Matrigel plug assays. Moreover, pseudolarix acid B significantly inhibited VEGF-induced tyrosine phosphorylation of kinase insert domain-containing receptor/fetal liver kinase-1 (KDR/flk-1), in correlation with a marked decrease in the phosphorylation of Akt and extracellular signal-regulated kinases (ERK). These findings collectively suggest that pseudolarix acid B possesses anti-angiogenic activity. One of the main anti-angiogenesis mechanisms of pseudolarix acid B may involve antagonism of the VEGF-mediated anti-apoptosis effect via inhibition of KDR/flk-1, ERK1/2, and Akt phosphorylation in endothelial cells.
Angiogenesis Inhibitors↗