Volume 3 Issue 1 by Fei Guan
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MLA
Luc Perneel, Fei Guan, Long Peng, Hasan Fayyad-Kazan, Martin Timmerman, “Rea... more Citation/Export
MLA
Luc Perneel, Fei Guan, Long Peng, Hasan Fayyad-Kazan, Martin Timmerman, “Real-time capabilities in the standard Linux Kernel: How to enable and use them?”, January 15 Volume 3 Issue 1 , International Journal on Recent and Innovation Trends in Computing and Communication (IJRITCC), ISSN: 2321-8169, PP: 131 - 135, DOI: 10.17762/ijritcc2321-8169.150127
APA
Luc Perneel, Fei Guan, Long Peng, Hasan Fayyad-Kazan, Martin Timmerman, January 15 Volume 3 Issue 1, “Real-time capabilities in the standard Linux Kernel: How to enable and use them?”, International Journal on Recent and Innovation Trends in Computing and Communication (IJRITCC), ISSN: 2321-8169, PP: 131 - 135, DOI: 10.17762/ijritcc2321-8169.150127
Papers by Fei Guan
Cimetidine (CIM), a histamine-2-receptor antagonist, has a long history of safe use in gastric ac... more Cimetidine (CIM), a histamine-2-receptor antagonist, has a long history of safe use in gastric acid-mediated gastrointestinal disorders. In this study, we used CIM, as an adjuvant, with pEGFP-Sj26 GST (the recombinant plasmid containing enhanced green fluorescent protein gene and the gene encoding 26 kDa glutathione S-transferase of Schistosoma japonicum) DNA vaccine to immunized mice and attempted to enhance the protective effect against S. japonicum. The results showed that the reduction rate of worm and egg burdens in the pEGFP-Sj26GST plus CIM group were 79.0% and 68.4%, respectively, significantly higher than that in pEGFP-Sj26GST alone group (27.0% and 22.5%, P<0.01). Compared with the pEGFP-Sj26GST alone group, mice immunized with pEGFP-Sj26GST plus CIM showed an elevated level of IFN-γ and IL-12 and a low level of IL-10 in splenocytes, while the levels of IL-4 and IL-5 showed no difference between the two groups. Our data also demonstrated that the percentage of CD4(+)CD25(+) regulatory T cells (Tregs) was significantly decreased in the spleens of mice immunized with pEGFP-Sj26GST plus CIM. All these findings suggest that CIM as a potential schistosome DNA vaccine adjuvant can enhance the protective effect of pEGFP-Sj26GST vaccine.
Biochemical and biophysical research communications, Jan 14, 2014
The role of autophagy in Hif-1α modulated activation of hepatic stellate cells was illustrated in... more The role of autophagy in Hif-1α modulated activation of hepatic stellate cells was illustrated in current work. Autophagy markers were determined in livers of Schistosoma japonicum infected mice and hypoxia or LPS treated human hepatic stellate cell, LX-2 cells. The action of Hif-1 to autophagy was defined as increase of autophagy markers was significantly suppressed in Hif-1α siRNA transfected cells upon hypoxia or LPS stimulation. The function of autophagy in activation of LX-2 cells was assessed as increase of activation markers was blocked using autophagy inhibitors under hypoxia and LPS stimulation. Conclusively, Hif-1α regulates activation of hepatic stellate cell by modulating autophagy.
A forced hydrolysis technique was used for preparing Sm 2 O 3 nanoscale powders at low processing... more A forced hydrolysis technique was used for preparing Sm 2 O 3 nanoscale powders at low processing temperatures. The technique used samarium oxide, nitric acid and urea as sources and had a potential for large-scale production for industrial applications. The various factors which influenced the sizes and coagulation of powder particles have been discussed in detail, and the influence mechanisms have been evaluated theoretically, the option result was found to be at 0.05 M Sm 3+ , 1.5 h isothermal maintenance at 90 • C. When the concentration of urea was kept at 1.0 M, the particles obtained by this method were spherical, the average size was 40 nm. The catalytic activity for the esterification of phthalic anhydride with octanol was also studied. The results showed that the nanoscale powder of Sm 2 O 3 was favored of increasing yield of ester and decreasing reaction time.
Veterinary Parasitology, 2012
Schistosomiasis is an important zoonosis and some livestock especially bovine and swine play a cr... more Schistosomiasis is an important zoonosis and some livestock especially bovine and swine play a crucial role on the disease transmission in endemic areas. The gold standard for animal Schistosoma japonicum infection is fecal examination although indirect agglutination assay (IHA) is so far mostly used in field survey and laboratory examination. Lack of sensitivity, poor practicality and high false positivity limit the use of those methods for routine veterinary detection as well as human diagnosis. A novel immunomagnetic bead ELISA based on IgY (egg yolk immunoglobulin) was developed for detection of circulating schistosomal antigen (CSA) in sera of hosts infected with S. japonicum. To assess the application of this method for diagnosis of domestic animal schistosomiasis with urine sample, the immunomagnetic bead ELISA based on IgY (IgY-IMB-ELISA) was employed in the present study to detect CSA in urine of murine schistosomiasis with either light (10 S. japonicum cercariae infection per mouse) or heavy infection (30 S. japonicum cercariae infection per mouse). The results showed that the CSA levels in urine of heavily and lightly infected mice reached a peak in 8 and 10 weeks after infection, respectively, remaining at a constant plateau in both groups by the end of the experiment (14 weeks after infection). The CSA level in urine of heavily infected mice was much higher than that of lightly infected mice from 8 to 14 weeks after infection. The effect of praziquantel treatment on the CSA level in urine of heavily infected mice was also investigated. It was found that the CSA level in urine of heavily infected mice with treatment was much lower than that of untreated mice at 4 weeks post-treatment, although still higher than that of control mice, and then gradually descended to the background level by 8 weeks after treatment. Our findings suggested that the IgY-IMB-ELISA may be an efficient and practical tool in non-invasive diagnosis of schistosome infection based on antigen detection, and evaluation of the efficacy of chemotherapy as well.
RNA, 2007
U1A protein negatively autoregulates itself by polyadeniylation inhibition of its own pre-mRNA by ... more U1A protein negatively autoregulates itself by polyadeniylation inhibition of its own pre-mRNA by binding as two molecules to a 39UTR-located Polyadeniylation Inhibitory Element (PIE). The (U1A)2-PIE complex specifically blocks U1A mRNA biosynthesis by inhibiting polyA tail addition, leading to lower mRNA levels. U1 snRNP bound to a 59ss-like sequence, which we call a U1 site, in the 39UTRs of certain papillomaviruses leads to inhibition of viral late gene expression via a similar mechanism. Although such U1 sites can also be artificially used to potently silence reporter and endogenous genes, no naturally occurring U1 sites have been found in eukaryotic genes. Here we identify a conserved U1 site in the human U1A gene that is, unexpectedly, within a bipartite element where the other part represses the U1 site via a base-pairing mechanism. The bipartite element inhibits U1A expression via a synergistic action with the nearby PIE. Unexpectedly, synergy is not based on stabilizing binding of the inhibitory factors to the 39UTR, but rather is a property of the larger ternary complex. Inhibition targets the biosynthetic step of polyA tail addition rather than altering mRNA stability. This is the first example of a functional U1 site in a cellular gene and of a single gene containing two dissimilar elements that inhibit nuclear polyadeniylation. Parallels with other examples where U1 snRNP inhibits expression are discussed. We expect that other cellular genes will harbor functional U1 sites. .
Proceedings of the National Academy of Sciences, 2003
Reducing or eliminating expression of a given gene is likely to require multiple methods to ensur... more Reducing or eliminating expression of a given gene is likely to require multiple methods to ensure coverage of all of the genes in a given mammalian cell. We and others [Furth, P. A., Choe, W. T., Rex, J. H., Byrne, J. C., and Baker, C. C. (1994) Mol. Cell. Biol. 14, 5278 -5289] have previously shown that U1 small nuclear (sn) RNA, both natural or with 5 end mutations, can specifically inhibit reporter gene expression in mammalian cells. This inhibition occurs when the U1 snRNA 5 end base pairs near the polyadeniylation signal of the reporter gene's pre-mRNA. This base pairing inhibits poly(A) tail addition, a key, nearly universal step in mRNA biosynthesis, resulting in degradation of the mRNA. Here we demonstrate that expression of endogenous mammalian genes can be efficiently inhibited by transiently or stably expressed 5 end-mutated U1 snRNA. Also, we determine the inhibitory mechanism and establish a set of rules to use this technique and to improve the efficiency of inhibition. Two U1 snRNAs base paired to a single pre-mRNA act synergistically, resulting in up to 700-fold inhibition of the expression of specific reporter genes and 25-fold inhibition of endogenous genes. Surprisingly, distance from the U1 snRNA binding site to the poly(A) signal is not critical for inhibition, instead the U1 snRNA must be targeted to the terminal exon of the pre-mRNA. This could reflect a disruption by the 5 end-mutated U1 snRNA of the definition of the terminal exon as described by the exon definition model. mutant U1 snRNAs ͉ gene expression inhibition ͉ polyadeniylation inhibition † To whom correspondence may be addressed.
Pigment Cell & Melanoma Research, 2008
The protease-activated receptor-2 (PAR-2) is a seven transmembrane G-protein-coupled receptor tha... more The protease-activated receptor-2 (PAR-2) is a seven transmembrane G-protein-coupled receptor that could be activated by serine protease cleavage or by synthetic peptide agonists. We showed earlier that activation of PAR-2 with Ser-Leu-Ile-Gly-Arg-Leu-NH(2) (SLIGRL), a known PAR-2 activating peptide, induces keratinocyte phagocytosis and increases skin pigmentation, indicating that PAR-2 regulates pigmentation by controlling phagocytosis of melanosomes. Here, we show that Leu-Ile-Gly-Arg-NH(2) (LIGR) can also induce skin pigmentation. Both SLIGRL and LIGR increased melanin deposition in vitro and in vivo, and visibly darkened human skins grafted onto severe combined immuno-deficient (SCID) mice. Both SLIGRL and LIGR stimulated Rho-GTP activation resulting in keratinocyte phagocytosis. Interestingly, LIGR activates only a subset of the PAR-2 signaling pathways, and unlike SLIGRL, it does not induce inflammatory processes. LIGR did not affect many PAR-2 signaling pathways, including [Ca(2+)] mobilization, cAMP induction, the induction of cyclooxgenase-2 (COX-2) expression and the secretion of prostaglandin E2, interleukin-6 and -8. PAR-2 siRNA inhibited LIGR-induced phagocytosis, indicating that LIGR signals via PAR-2. Our data suggest that LIGR is a more specific regulator of PAR-2-induced pigmentation relative to SLIGRL. Therefore, enhancing skin pigmentation by topical applications of LIGR may result in a desired tanned-like skin color, without enhancing inflammatory processes, and without the need of UV exposure.
Pharmacological Research, 2011
The cancer preventive activities of tea (Camellia sinensis Theaceae) have been studied extensivel... more The cancer preventive activities of tea (Camellia sinensis Theaceae) have been studied extensively. Inhibition of tumorigenesis by green tea extracts and tea polyphenols has been demonstrated in different animal models, including those for cancers of the skin, lung, oral cavity, esophagus, stomach, small intestine, colon, bladder, liver, pancreas, prostate, and mammary glands. Many studies in cell lines have demonstrated the modulation of signal transduction and metabolic pathways by (−)-epigallocatechin-3-gallate (EGCG), the most abundant and active polyphenol in green tea. These molecular events can result in cellular changes, such as enhancement of apoptosis, suppression of cell proliferation, and inhibition of angiogenesis. Nevertheless, the molecular mechanisms of inhibition of carcinogenesis in animals and humans remain to be further investigated. Future research directions in this area are discussed.
Parasitology Research, 2011
It has been known that parasites developed sophisticated strategies to escape from the host immun... more It has been known that parasites developed sophisticated strategies to escape from the host immune assault. More recently, one strategy to induce immune evasion involved CD4(+)CD25(+) regulatory T cells (Tregs). Mice were infected with Schistosoma japonicum cercariae and then injected intraperitoneally with anti-CD25 monoclonal antibody (anti-CD25 mAb). The results showed that the percentages of CD4(+)CD25(+) Tregs in mice were expanded by S. japonicum infection, and it could be partially blocked by anti-CD25 mAb. Worm burden in anti-CD25 mAb group (23.17 ± 6.94) was significantly lower than that in infected group (30.17 ± 5.85). The level of interferon gamma was increased with anti-CD25 mAb administration; meanwhile, lower concentration of interleukin 10 was observed in the same group. These results suggest that CD4(+)CD25(+) Tregs contribute to the escape of S. japonicum from the host immune responses, while anti-CD25 mAb can partially block CD4(+)CD25(+) Tregs and enhance the protective immunity to the parasite by Th1-type immune response.
Molecular and Cellular Biology, 2003
The human U1 snRNP-specific U1A protein autoregulates its own production by binding to and inhibi... more The human U1 snRNP-specific U1A protein autoregulates its own production by binding to and inhibiting the polyadeniylation of its own pre-mRNA. Previous work demonstrated that a short sequence of U1A protein is essential for autoregulation and contains three distinct activities, which are (i) cooperative binding of two U1A proteins to a 50-nucleotide region of U1A pre-mRNA called polyadeniylation-inhibitory element RNA, (ii) formation of a novel homodimerization surface, and (iii) inhibition of polyadeniylation by inhibition of poly(A) polymerase (PAP). In this study, we purified and analyzed 11 substitution mutant proteins, each having one or two residues in this region mutated. In 5 of the 11 mutant proteins, we found that particular amino acids associate with one activity but not another, indicating that they can be uncoupled. Surprisingly, in three mutant proteins, these activities were improved upon, suggesting that U1A autoregulation is selected for suboptimal inhibitory efficiency. The effects of these mutations on autoregulatory activity in vivo were also determined. Only U1A and U170K are known to regulate nuclear polyadeniylation by PAP inhibition; thus, these results will aid in determining how widespread this type of regulation is. Our molecular dissection of the consequences of conformational changes within an RNP complex presents a powerful example to those studying more complicated pre-mRNA-regulatory systems.
Materials Chemistry and Physics, 2001
Nanocrystalline nickel powders were prepared from aqueous solution by reducing their correspondin... more Nanocrystalline nickel powders were prepared from aqueous solution by reducing their corresponding metal salts under suitable conditions. The experimental conditions including the types and concentration of protective agents, feeding order and the pH of the solution that influence the average particle size were studied in detail. X-ray powder diffraction patterns show that the nickel powder is cubic crystallite. The average particle size of the ultrafine nickel powder is 50 nm. In addition, we also studied the effect of particle size in liquid phase dehydrogenation of 2-butanol. The results show that the smaller particle size is favored of increasing catalytic activity.
Journal of Agricultural and Food Chemistry, 2013
Tocopherols are the major source of dietary vitamin E. In this study, the growth inhibitory effec... more Tocopherols are the major source of dietary vitamin E. In this study, the growth inhibitory effects of different forms of tocopherols (T), tocopheryl phosphates (TP), and tocopherol quinones (TQ) on human colon cancer HCT116 and HT29 cells were investigated. δ-T was more active than γ-T in inhibiting colon cancer cell growth, decreasing cancer cell colony formation, and inducing apoptosis; however, α-T was rather ineffective. Similarly, the rate of cellular uptake also followed the ranking order δ-T > γ-T ≫ α-T. TP and TQ generally had higher inhibitory activities than their parent compounds. Interestingly, the γ forms of TP and TQ were more active than the δ forms in inhibiting cancer cell growth, whereas the α forms were the least effective. The potencies of γ-TQ and δ-TQ (showing IC50 values of ∼0.8 and ∼2 μM on HCT116 cells after a 72 h incubation, respectively) were greater than 100-fold and greater than 20-fold higher, respectively, than those of their parent tocopherols. Induction of cancer cell apoptosis by δ-T, γ-TP, and γ-TQ was characterized by the cleavage of caspase 3 and PARP1 and DNA fragmentation. These studies demonstrated the higher growth inhibitory activity of δ-T than γ-T, the even higher activities of the γ forms of TP and TQ, and the ineffectiveness of the α forms of tocopherol and their metabolites against colon cancer cells.
Foodborne Pathogens and Disease, 2013
Vaccination is the most effective and cost-effective way to treat hepatitis B virus (HBV) infecti... more Vaccination is the most effective and cost-effective way to treat hepatitis B virus (HBV) infection. Collective data suggest that helminth infections affect immune responses to some vaccines. Therefore, it is important to reveal the effects of helminth infections on the efficacy of protective vaccines in countries with highly prevalent helminth infections. In the present work, effects of Trichinella spiralis infection on the protective efficacy of HBV vaccine in a mouse model were investigated. This study demonstrated that the enteric stage of T. spiralis infection could inhibit the proliferative response of spleen lymphocytes to hepatitis B surface antigen (HBsAg) and lead to lower levels of anti-HBsAg antibodies, interferon-γ, and interleukin (IL)-2, along with higher levels of IL-4 and IL-5. However, these immunological differences are absent in the muscle stage of T. spiralis infection. The results suggest that the muscle stage of T. spiralis infection does not affect the immune response to HBV vaccination, while the enteric-stage infection results in a reduced immune response to HBsAg.
Experimental Parasitology, 2014
Cancer Prevention Research, 2012
The cancer preventive activity of vitamin E has been extensively discussed, but the activities of... more The cancer preventive activity of vitamin E has been extensively discussed, but the activities of specific forms of tocopherols have not received sufficient attention. Herein, we compared the activities of δ-tocopherol (δ-T), γ-T, and α-T in a colon carcinogenesis model. Male F344 rats, seven weeks old, were given two weekly subcutaneous injections of azoxymethane (AOM) each at a dose of 15 mg/kg body weight. Starting 1 week before the AOM injection, the animals were maintained on a modified AIN76A diet, or the same diet containing 0.2% of δ-T, γ-T, α-T, or a γ-T-rich mixture of tocopherols (γ-TmT), until the termination of the experiment at 8 weeks after the second AOM injection. δ-T treatment showed the strongest inhibitory effect, decreasing the numbers of aberrant crypt foci by 62%. γ-T and γ-TmT were also effective, but α-T was not. Immunohistochemical analysis showed that δ-T and γ-T treatments reduced the levels of 4-hydroxynonenal and nitrotyrosine and the expression of cyclin D1 in the colon, preserved the expression of PPAR-γ, and decreased the serum levels of prostaglandin E2 and 8-isoprostane. Supplementation with 0.2% δ-T, γ-T, or α-T increased the respective levels of tocopherols and their side-chain degradation metabolites in the serum and colon tissues. Rather high concentrations of δ-T and γ-T and their metabolites were found in colon tissues. Our study provides the first evidence for the much higher cancer preventive activity of δ-T and γ-T than α-T in a chemically induced colon carcinogenesis model. It further suggests that δ-T is more effective than γ-T.
Applied Surface Science, 2004
Applied Surface Science, 2005
Applied Surface Science, 2004
Silane coupling reagent (3-mercaptopropyl trimethoxysilane (MPTS)) was prepared on single-crystal... more Silane coupling reagent (3-mercaptopropyl trimethoxysilane (MPTS)) was prepared on single-crystal Si substrate to form two-dimensional self-assembled monolayer (SAM) and the terminal -SH group in the film was in situ oxidized to -SO 3 H group to endow the film with good chemisorption ability. Thus, ZrO 2 thin film were deposited on the oxidized MPTS-SAM, by enhanced hydrolysis of zirconium sulfate (Zr(SO 4 ) 2 Á4H 2 O) solution in the presence of HCl at 70 8C, making use of the chemisorption ability of the -SO 3 H group. The thickness of the films was determined with an ellipsometer, while the chemical feature, phase composition, thermal stability, and morphology of the films were analyzed by means of Fourier transformation infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction analysis, thermogravimetric analysis, and atomic force microscopy. As the results, the as-deposited ZrO 2 film was composed of nanocrystalline tetragonal ZrO 2 (t-ZrO 2 ) and an amorphous basic zirconium sulfate. The annealing of the films at 500 8C led to crystallization to t-ZrO 2 , while further heating to 800 8C eliminated S in the film, and the ZrO 2 film consisted of nanocrystalline tetragonal ZrO 2 and monoclinic ZrO 2 in this case. The as-deposited ZrO 2 thin films were compact and crack-free, showing quadratically-looking features which were not observed previously, while the thickness of the ZrO 2 films decreased with increasing annealing temperature. Since the ZrO 2 film was well adhered to the MPTS-SAM, it might find promising application in the surface-modification of single-crystal Si and SiC in microelectromechanical systems (MEMS). #
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Volume 3 Issue 1 by Fei Guan
MLA
Luc Perneel, Fei Guan, Long Peng, Hasan Fayyad-Kazan, Martin Timmerman, “Real-time capabilities in the standard Linux Kernel: How to enable and use them?”, January 15 Volume 3 Issue 1 , International Journal on Recent and Innovation Trends in Computing and Communication (IJRITCC), ISSN: 2321-8169, PP: 131 - 135, DOI: 10.17762/ijritcc2321-8169.150127
APA
Luc Perneel, Fei Guan, Long Peng, Hasan Fayyad-Kazan, Martin Timmerman, January 15 Volume 3 Issue 1, “Real-time capabilities in the standard Linux Kernel: How to enable and use them?”, International Journal on Recent and Innovation Trends in Computing and Communication (IJRITCC), ISSN: 2321-8169, PP: 131 - 135, DOI: 10.17762/ijritcc2321-8169.150127
Papers by Fei Guan
MLA
Luc Perneel, Fei Guan, Long Peng, Hasan Fayyad-Kazan, Martin Timmerman, “Real-time capabilities in the standard Linux Kernel: How to enable and use them?”, January 15 Volume 3 Issue 1 , International Journal on Recent and Innovation Trends in Computing and Communication (IJRITCC), ISSN: 2321-8169, PP: 131 - 135, DOI: 10.17762/ijritcc2321-8169.150127
APA
Luc Perneel, Fei Guan, Long Peng, Hasan Fayyad-Kazan, Martin Timmerman, January 15 Volume 3 Issue 1, “Real-time capabilities in the standard Linux Kernel: How to enable and use them?”, International Journal on Recent and Innovation Trends in Computing and Communication (IJRITCC), ISSN: 2321-8169, PP: 131 - 135, DOI: 10.17762/ijritcc2321-8169.150127