You-nan Chen

Sichuan University, Chengdu, Sichuan Sheng, China

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Publications (8)5.09 Total impact

  • Chinese medical journal 02/2013; 126(3):578-85. · 0.90 Impact Factor
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    ABSTRACT: To evaluate the diagnostic value of serum galactomannan antigen (GM) and (1→3)-β-D-glucan antigen (BG) assay in invasive fungal infections (IFI) in the patients with hematologic malignancies and the role in monitoring therapeutic response. Fifty one patients with hematological malignancies met the criteria for inclusion: (1) body temperature above 38°C for 48 hours, (2) failure to respond to broad-spectrum antibiotic treatment, or (3) temperature rose again after the responded drop. Blood samples were collected twice at the first week, then once a week in at least four weeks. The double antibody sandwich enzyme-linked immunosorbent assay (ELISA) and colorimetric assay were used for detecting GM and BG. The positive GM test is defined as two consecutive tests at different time GM value > 0.5 or > 0.8 and the positive G test is defined as BG value > 80 pg/ml. The patients were assigned into four groups as proven, probable, possible, and non-fungal infection respectively, and 21 normal volunteers were as controls. Two hundred and forty serum samples were collected from 51 patients including 2 of proven IFI, 26 probable IFI, 17 possible IFI and 6 non-fungal infection. The true-positive group including the proven and probable groups, and true negative group was the non-fungal infection group. GM tests were positive in 21 of 28 cases in true positive group, and only one of 6 cases in non-fungal infection. The sensitivity, specificity, positive predictive value and negative predictive value were 75%, 83.3%, 95.5% and 41.7%, respectively. G tests were positive in all 28 cases of the true positive group, and 4 in 6 non-fungal infection cases. The sensitivity, specificity, positive predictive value and negative predictive value were 100%, 33.3%, 87.5% and 100%, respectively. G test is more sensitive than GM test (P = 0.015), but there was no significant difference in specificity of the two tests (P = 0.242). In 19 of 21 patients with GM test positive, anti-fungal treatment was effective, and GM value gradually decreased to negative, two invalid patients were persistent with GM test positive. After two weeks treatment, the average GM value was significantly lower in the effective group than in the ineffective group (P < 0.05). BG values in the responded patients showed a gradual decline similar to that of GM values, but not to negative. The changes of BG value in ineffective group varied with a trend upward. The changes in BG value had no relation with treatment effectiveness. Serum GM and BG antigens detection provides strong evidence for early diagnosis of IFI. Combination of GM and G tests can improve the diagnostic specificity and reduce the false positive GM test seems superior to G test for monitoring GM and BG values during treatment.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 01/2011; 32(1):43-6.
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    ABSTRACT: To investigate the effect of immunosuppression agent Everolimus on the viability and function of insuloma cells (INS-1) and pancreatic islet cells cultured in vitro. INS-1 cells and islets were treated with a series of concentrations of immunosuppression agents (Everolimus, Cyclosporin A, Sirolimus and Mycophenolate Mofetil). The viability of INS-1 cells and rat pancreatic islets were determined with MTT and the function of INS-1 cells and rat pancreatic islets was evaluated with Glucose-stimulated insulin secretion assay. Above the clinical blood concentration, the inhibition rate of islet cell proliferation in the high concentration group of Everolimus and Sirolimus was significantly lower than that of Cyclosporin A and Mycophenolate Mofetil group (P < 0.05); Everolimus in the blood drug level, like other immunosuppressive agents, can inhibit the function of insulin secretion, and the stimulation index of each group was no significant difference. Compared to Mycophenolate Mofetil and Cyclosporin A, Everilimus and Sirolimus demonstrate lower toxicity effect on INS-1 cells and rat pancreatic islets in vitro and Everolimus is expected as a new type of immunosuppressive agent used in clinical islet transplantation.
    Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 01/2010; 41(1):68-72.
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    ABSTRACT: To compare the effects of enteral nutrition (EN) and parenteral nutrition (PN) on gut mucosal barrier function and intestinal epithelial tight junctions in rats after surgical stress. Fifty SD rats with surgical trauma were randomly divided into three groups: total parenteral nutrition (TPN) group and enteral nutrition (EN) group with isocaloric and isonitrogenous nutrition and placebo group. Nutrients were administered via the neck vein and needle jejunostomy for the TPN group. The homogenated tissues of liver, lung, and mesenteric lymph nodes were cultured to determine the bacterial translocations rates. The transmembrane binding proteins (occludin) were measured with immunohistochemistry. The ultrastructure and morphology of intestinal epithelial tight junctions were observed by electron microscope. The feces in cecum were cultured for anaerobic bacterial growth analyses. The EN group had more lactobacteria and bifydobacteria than the TPN group, but not statistical significant. The EN group had greater expression of occludin in the intestines than the TPN group. Furthermore, the intestinal epithelial tight junction and microvilli of the EN group were more intact compared with those of the TPN group. The bacterial translocations rates of liver, lung and mesenteric lymph nodes were significantly lower in the EN group than in the TPN group. Neither EN nor standard PN maintains intestinal membrane barriers. But EN increases the expression of transmember binding proteins, maintains the gut epithelial tight junction, improves intestinal mucosal barrier and reduces gut bacterial translocation.
    Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 07/2009; 40(4):615-8.
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    ABSTRACT: To investigate the effects of ecoimmunonutrition supplement on intestinal microecology, epithelial tight junctions, and barrier function in rats with surgical stress. Seventy SD rats after surgical trauma were randomly divided into four groups:(1) placebo group,(2)total parenteral nutrition(TPN) group,(3)enteral nutrition(EN) group and (4)ecoimmunonutrition (EEN)group respectively. Rats received isocaloric and isonitrogenous nutrition. Nutrients were administered via the neck vein and the needle jejunostomy for five days. The homogenated tissues of liver, lung, and mesenteric lymph nodes were cultured to determine the bacterial translocation rate. The transmembrane binding proteins(occludin) was measured by immunohistochemistry. The ultrastructure and morphology of intestinal epithelial tight junctions in the intestine were observed by electron microscope. The feces in cecum was cultured for anaerobic bacterial growth and analysed. The amounts of lactobacteria and bifidobacteria in EEN group were significantly higher than those in TPN group(P<0.05). The expression levels of occludin in the intestine was significantly higher in EEN group than that in TPN and EN group. Furthermore, the intestinal epithelial tight junction and microvilli of EEN group were more intact compared with those of TPN group. The bacterial translocation rates of liver, lung and mesenteric lymph nodes were significantly lower in EEN and EN group than those in TPN group(P<0.05). Application of ecoimmunonutrition can protect intestinal mucosal barrier in rats with operative stress, increase the expression of occludin, maintain the gut epithelial tight junction, and eliminate gut bacterial translocation.
    Zhonghua wei chang wai ke za zhi = Chinese journal of gastrointestinal surgery 05/2009; 12(3):306-9.
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    ABSTRACT: Mesenchymal stem cells (MSCs) play an important role in the development and growth of tumor cells. The purpose of this study is to confirm the effect of MSCs on tumor cell growth in vitro and in vivo and to elucidate the mechanism. MSCs were isolated from mouse bone marrow and cocultured with murine hepatoma H22, lymphoma (YAC-1 and EL-4) and rat insulinoma INS-1 cell lines. The growth inhibitory effect of MSCs on tumor cells was tested through MTT and 3H-TdR incorporation assay. The apoptosis induction effect of MSCs on tumor cells was assessed with flow cytometry (FCM) and RT-PCR assay. MSCs were inoculated into BALB/c mice alone or coinoculated with ascitogenous hepatoma cells intraperitonealy, respectively. The tumor growth inhibition of MSCs was investigaed through the incidence and volume of ascites formation, and the immunosuppression effect was studied with splenocyte response to ConA stimulation test and T cell subsets analysis (FCM). The results showed that MSCs exhibited a number-dependent growth inhibitory effect on murine tumor cell lines in vitro and inhibited the growth of ascitogenous hepatoma cells in vivo without host immunosuppression. MSCs could upregulate tumor cells mRNA expression of cell cycle negative regulator p21 and apoptosis associated protease caspase 3. The findings of this experimental study demonstrated that MSCs had potential inhibitory effects on tumor cell growth in vitro and in vivo without host immunosuppression, by inducing apoptotic cell death and G(0)/G(1) phase arrest of cancer cells.
    Cancer biology & therapy 03/2008; 7(2):245-51. · 3.29 Impact Factor
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    ABSTRACT: To screen the target rhesus genes and give some basic genetic evidences to its value as one of the most important animal model in biomedical study, we constructed a cDNA expression library from liver tissue of a healthy rhesus monkey. With Trizol reagent, the total RNA was extracted from healthy rhesus liver tissue. By mutant Moloney Murine Leukemia Virus Reverse Transcriptase (MMLV-RT), the first-strand cDNA was synthesized from purified mRNA, and subsequently the second-strand cDNA was generated via E. coli DNA polymerase I . Then, the EcoR I adapter was added to the synthesized double-strand cDNA, which was subsequently digested by Xho I restriction enzyme and fractionated with CHROMA APIN-400 column. The fractionated cDNA fragments to be longer than 0. 5 kb were ligated into lambda ZAP express vector to form the phagemid cDNA recombinants, which were further packaged into the lambda ZAP cDNA library according to the standard protocol with phage lambda Gold packaging extract. In order to get more stable clones with larger quantity, the primary library was amplified through infecting the host strain XL1-Blue MRF'. Then, the library titre, recombinant rate and length of inserted cDNA were measured, respectively. The capacity of the primary stand or unamplified library was 1. 2X 10(6) pfu. The titers of the unamplified library or the amplified library was 1.1 X 10(6) mixture, pfu/mL or 7. 7 X 10(9) pfu/mL respectively, the percentages of recombinants were 99. 3% and 98. 2%, and the average lengths of the inserts were 2.0 kb and 2. 3 kb, respectively. An excellent cDNA expression library has been constructed successfully, which would lay solid foundation for transplantation study and pre-clinic evaluation of related drugs.
    Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 07/2007; 38(3):378-81.
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    ABSTRACT: Porcine liver performing efficient physiological functions in the human body is prerequisite for successful liver xenotransplantation. However, the protein differences between pig and human remain largely unexplored. Therefore, we investigated the liver expression profile of a highly inbred minipig line. A cDNA library was constructed from liver tissue of an inbred Banna minipig. Two hundred randomly selected clones were sequenced then analysed by BLAST programme. Alignments of the sequences showed 44% encoded previously known porcine genes. Among the 56% unknown genes, sequences of 72 clones had high similarities with known genes of other species and the similarities to human were mostly above 0.80. The other 40 clones showing no similarity to genes in National Centre for Biotechnology Information are newly discovered, expressed sequence tags specific to liver of inbred Banna minipig. Twenty-two of the 200 clones had full length encoding regions, 38 complete 5' terminal sequences and 140 complete 3' terminal sequences. These newly discovered expression sequences may be an important resource for research involving physiological characteristics and medical usage of inbred pigs and contribute to matching studies in xenotransplantation.
    Chinese medical journal 06/2007; 120(9):739-42. · 0.90 Impact Factor