1. |
- Fang Kullander, Fang, 1962-
(author)
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Phylogeny and species diversity of the South and Southeast Asian cyprinid genus Danio Hamilton (Teleostei, Cyprinidae)
- 2001
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Doctoral thesis (other academic/artistic)abstract
- Danio Hamilton, in the wide sense, consists of 66 nominal species, of which about 45 are valid. Four species, viz. D. kakhienensis, D. laoensis, D. shanensis and D. browni, were revalidated in papers revising the genus. Six species were found to be new to science: Danio maetaengensis from northern Thailand; D. kyathit from northern Myanmar; D. apopyris, D. acrostomus and D. leptos form northern Laos; and D. roseus from northeastern Thailand and northwestern Laos. Daniops myersi was confirmed to be a junior synonym of D. laoensis.Three species groups have been recognized among Danio (s. l.) species based mainly on colour pattern and other morphological characters: the striped danios, the barred danios and the Danio dangila species group. The striped danios differ from barred danios in having more branched dorsal-fin rays, a complete lateral line, two pairs of short barbels and a P stripe extending to the end of the caudal-fin rays (instead of the P stripe being confined to the caudal peduncle).A few characters common to both striped and barred danios but absent in the Danio dangila species group are, e. g., a cleithral spot immediately behind the gill-opening and a skin groove on the supraorbital shelf. A phylogenetic analysis shows that Danio is paraphyletic. Two monophyletic groups can be recognized within the non-monophyletic genus Danio, one comprising only the Danio dangila species group, and the other including all the striped and barred danios. The first group thus represents the genus Danio (s. str.), and the latter a distinct genus Devario, with the type species D. devario. The monophyly of Danio is strongly supported, and its sister group is Esomus. Chela and Inlecypris are closely related to each other, and they form the sister group of Devario. Brachydanio is confirmed to be a junior synonym of Danio (s. str.). Danio erythromicron is excluded from both Danio (s. str.) and Devario. Its generic status is pending further study. The phylogenetic relationships of Sundadanio axelrodi and Danionella translucida to Danio (s. str.) and Devario remain unresolved.
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3. |
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4. |
- Belting, Mattias, et al.
(author)
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Glypican-1 is a vehicle for polyamine uptake in mammalian cells. A pivotal role for nitrosothiol-derived nitric oxide.
- 2003
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In: Journal of Biological Chemistry. - 1083-351X. ; 278:47, s. 47181-47189
-
Journal article (peer-reviewed)abstract
- Polyamines (putrescine, spermidine, and spermine) are essential for growth and survival of all cells. When polyamine biosynthesis is inhibited, there is up-regulation of import. The mammalian polyamine transport system is unknown. We have previously shown that the heparan sulfate (HS) side chains of recycling glypican-1 (Gpc-1) can sequester spermine, that intracellular polyamine depletion increases the number of NO-sensitive N-unsubstituted glucosamines in HS, and that NO-dependent cleavage of HS at these sites is required for spermine uptake. The NO is derived from S-nitroso groups in the Gpc-1 protein. Using RNA interference technology as well as biochemical and microscopic techniques applied to both normal and uptake-deficient cells, we demonstrate that inhibition of Gpc-1 expression abrogates spermine uptake and intracellular delivery. In unperturbed cells, spermine and recycling Gpc-1 carrying HS chains rich in N-unsubstituted glucosamines were co-localized. By exposing cells to ascorbate, we induced release of NO from the S-nitroso groups, resulting in HS degradation and unloading of the sequestered polyamines as well as nuclear targeting of the deglycanated Gpc-1 protein. Polyamine uptake-deficient cells appear to have a defect in the NO release mechanism. We have managed to restore spermine uptake partially in these cells by providing spermine NONOate and ascorbate. The former bound to the HS chains of recycling Gpc-1 and S-nitrosylated the core protein. Ascorbate released NO, which degraded HS and liberated the bound spermine. Recycling HS proteoglycans of the glypican-type may be plasma membrane carriers for cargo taken up by caveolar endocytosis.
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5. |
- Bischoff M. M. J., Fang C. M. , De Groot R. A. , Heijnen G. M. M. , Katsnelson M. I. , Kolesnychenko O. Yu. , De Kort R. , Lichtenstein A. I. , Quinn A. J. , de Parma A. L. V. , Yamada T. K. , and Van Kempen H.
(author)
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Scanning tunneling spectroscopy study of surface states of 3d metals: Chemical identification, magnetic contrast and orbital Kondo resonance states
- 2003
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In: Acta Physica Polonica A. ; , s. 231-
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Conference paper (peer-reviewed)
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6. |
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7. |
- Charpentier, Emmanuelle, et al.
(author)
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Novel cassette-based shuttle vector system for Gram-positive bacteria.
- 2004
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In: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 70:10, s. 6076-6085
-
Journal article (peer-reviewed)abstract
- Our understanding of staphylococcal pathogenesis depends on reliable genetic tools for gene expression analysis and tracing of bacteria. Here, we have developed and evaluated a series of novel versatile Escherichia coli-staphylococcal shuttle vectors based on PCR-generated interchangeable cassettes. Advantages of our module system include the use of (i) staphylococcal low-copy-number, high-copy-number, thermosensitive and theta replicons and selectable markers (choice of erythromycin, tetracycline, chloramphenicol, kanamycin, or spectinomycin); (ii) an E. coli replicon and selectable marker (ampicillin); and (iii) a staphylococcal phage fragment that allows high-frequency transduction and an SaPI fragment that allows site-specific integration into the Staphylococcus aureus chromosome. The staphylococcal cadmium-inducible P(cad)-cadC and constitutive P(blaZ) promoters were designed and analyzed in transcriptional fusions to the staphylococcal beta-lactamase blaZ, the Vibrio fischeri luxAB, and the Aequorea victoria green fluorescent protein reporter genes. The modular design of the vector system provides great flexibility and variety. Questions about gene dosage, complementation, and cis-trans effects can now be conveniently addressed, so that this system constitutes an effective tool for studying gene regulation of staphylococci in various ecosystems.
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8. |
- Chaudhuri, A, et al.
(author)
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Development of Duffy transgenic mouse: in vivo expression of human Duffy gene with -33T -> C promoter mutation in non-erythroid tissues
- 2004
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In: British Journal of Haematology. - : Wiley. - 0007-1048. ; 127:3, s. 356-359
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Journal article (peer-reviewed)abstract
- Blood group Duffy gene (FY) promoter in Duffy-negative individuals contains a point mutation in the GATA1 protein-binding motif, which was suggested to be responsible for erythroid suppression of FY. We developed two transgenic mouse lines with FY from both Duffy phenotypes. Transgenic mice with FY from Duffy-positive phenotype expressed Duffy protein both in red blood cells (RBCs) and non-erythroid tissues. Transgenic mice with FY from Duffy-negative phenotype did not express Duffy protein in RBCs, but it was expressed in non-erythroid tissues. This is the first in vivo experimental evidence showing the effect of -33T-->C promoter mutation on FY expression.
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9. |
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10. |
- Chen, Fang, 1963, et al.
(author)
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Effect of noise on automatic speech recognition system error rate
- 2000
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In: Proceedings of the Human Factors and Ergonomics Society Annual Meeting July 2000. - : SAGE Publications. - 2169-5067 .- 1071-1813. ; 44:37, s. 606-609
-
Conference paper (peer-reviewed)abstract
- Many studies have indicted that stress and workload can effect the recognition accuracy of the speech recognition system. This can include noise, vibration, G-force, information overload, vocal quality in noise, vocal quality and psychological stress, concurrent task performance and vocal fatigue. The commercially available speech recognition system has not yet reached the perfect design to recognize natural human speech. The military application of automatic speech recognition systems has been studied in a wide arrangement. Verbex’ Voice Master was recommended in its instruction book as especially suited well for use in a noisy environment. This system was selected as a candidate system for use in cockpits. Before implementing it in the cockpit, its strengths and weaknesses for special utterances need to be tested in a laboratory environment. The purpose of the study was to investigate the effects of noise on recognition accuracy in dual-task performance. The experiment was carried out in a noise-insulated room. The Verbex’ Voice Master speech recognition system was installed into the computer. Eleven male Swedish students were the subjects. Two noise levels were set up with a combination of mental workload and physical workload. The results showed that without noise and mental workload, the recognition accuracy could be as good as 99.4%. With noise and mental workload, the recognition accuracy could be reduced to 95%. The results indicated that noise had significant effects on the computer error while mental workload had significant effects on both subject error and computer error.
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11. |
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12. |
- Chen, Fang
(author)
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Localization of 3-D sound presented through headphone - Duration of sound presentation and localization accuracy
- 2003
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In: Journal of The Audio Engineering Society. - 1549-4950. ; 51:12, s. 1163-1171
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Journal article (peer-reviewed)abstract
- The relationship between the duration of a sound presentation and the accuracy of human localization is investigated. The three-dimensional sound is presented via headphones. The head-tracking system was integrated together with the sound presentation. Generalized head-related transfer functions (HRTFs) are used in the experiment. Six different types of sounds with durations of 0.5, 2, 4, and 6 seconds were presented in random order on any azimuth in the horizontal plane. Thirty subjects participated in the study. A special location indication system called DINC (directional indication compass) was developed. With DINC the judged location of every test can be recorded accurately. The results showed that the localization accuracy is significantly related to the duration of the sound presentation. As long as the sound has a broad frequency bandwidth, the sound type has little effect on the localization accuracy. A presentation of at least 4-second duration is recommended. There is no significant difference between male and female subjects in the accuracy of detection.
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14. |
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15. |
- Chen, Fang, 1963
(author)
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Speech interaction system how to increase its usability
- 2004
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In: The 8th International Conference on Spoken Language Processing, Interspeech 2004, ICSL. Jeju Island, Korea.
-
Conference paper (peer-reviewed)abstract
- This paper discussed different issues related to the usability of speech interaction system. It includes the usability concept, different design approaches, design process and evaluation questions for speech interaction system. Usability is a very fuzzy concept, especially when it related to the speech interaction system: it is hard to measure and it is very much context dependent. The traditional user-centered design approach may not be suitable for the speech interaction system design since the users might not have enough knowledge to see what the technology can do. Usage-centered design may be the better method but there is not comprehensive theory and methodology for the design process and evaluation.
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16. |
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17. |
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18. |
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19. |
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20. |
- Cheng, Fang, et al.
(author)
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Differences in the uptake and nuclear localization of anti-proliferative heparan sulfate between human lung fibroblasts and human lung carcinoma cells
- 2001
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In: Journal of Cellular Biochemistry. - : Wiley. - 0730-2312 .- 1097-4644. ; 83:4, s. 597-606
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Journal article (peer-reviewed)abstract
- Heparan sulfate inhibits the proliferation of normal human lung fibroblasts (HFL-1) but not of a human lung carcinoma cell-line (A549). in this study we investigated possible mechanisms and structural requirements by which anti proliferative heparan sulfates exerts its effects on binding, uptake and subcellular localisation. Both HFL-1 and A549 cells were incubated with I-125- or rhodamine-labeled L-iduronate-rich antiproliferative heparan sulfate species as well as L-iduronate-poor inactive ones. The anti proliferative heparan sulfate was bound to the cell surface on both HFL-1 and A549 cells, but to a lesser extent and with less affinity to A549 cells. Both cell types bound the anti proliferative heparan sulfate with one high- and with one low affinity site. The L-iduronate-poor heparan sulfate bound to a lesser extent and with less affinity to both cell types compared to the anti proliferative heparan sulfate. The antiproliferative heparan sulfate accumulated in the cytoplasm of HFL-1 cells after 24 h incubation, but after 72 h it was found evenly distributed in the nucleus. The time-scale for anti proliferative activity correlated with nuclear localization. In contrast, in A549 cells it was only found near the nuclear membrane. The inactive heparan sulfate was taken up in considerably smaller amounts compared to the antiproliferative heparan sulfate and could not be detected in the nucleus of either HFL-1 or A549 cells. Our data suggest that the anti proliferative activity of L-iduronate-rich heparan sulfate on normal fibroblasts may be due to direct effects on nuclear processes, such as gene transcription.
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21. |
- Cheng, Fang, et al.
(author)
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Nitric oxide-dependent processing of heparan sulfate in recycling S-nitrosylated glypican-1 takes place in caveolin-1 containing endosomes.
- 2002
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In: Journal of Biological Chemistry. - 1083-351X. ; 277:46, s. 44431-44439
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Journal article (peer-reviewed)abstract
- We have previously demonstrated intracellular degradation of the heparan sulfate side-chains in recycling glypican-1 by heparanase and by deaminative cleavage at N-unsubstituted glucosamine with nitric oxide derived from intrinsic nitrosothiols [see Ding, K., Mani, K., Cheng, F., Belting, M. and Fransson, L.-. (2002) J. Biol. Chem., 277, xxx-xxx; prepub M203383200]. To determine where and in what order events take place, we have visualized, by using confocal laser-scanning immunofluorescence microscopy, glypican-1 variants in unperturbed cells or arrested at various stages of processing. In unperturbed proliferating cells, glypican-1 was partly S-nitrosylated. Intracellular glypican-1 was enriched in endosomes, colocalized significantly with GM-1 ganglioside, caveolin-1 and Rab9-positive endosomes, and carried side-chains rich in N-unsubstituted glucosamine residues. However, such residues were scarce in cell-surface glypican-1. Brefeldin A-arrested glypican-1, which was non-S-nitrosylated and carried side-chains rich in N-unsubstituted glucosamines, colocalized extensively with caveolin-1 but not with Rab9. Suramin, which inhibits heparanase, induced the appearance of S-nitrosylated glypican-1 in caveolin-1-rich compartments. Inhibition of deaminative cleavage did not prevent heparanase from generating heparan sulfate oligosaccharides that colocalized strongly with caveolin-1. Growth-quiescent cells displayed extensive NO-dependent deaminative cleavage of heparan sulfate generating anhydromannose-terminating fragments which were partly associated with acidic vesicles. Proliferating cells generated such fragments during polyamine uptake. We conclude that recycling glypican-1 that is associated with caveolin-1-containing endosomes undergoes sequential N-desulfation/N-deacetylation, heparanase cleavage, S-nitrosylation, NO-release and deaminative cleavage of its side-chains in conjunction with polyamine uptake.
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22. |
- Di Cesare, PE, et al.
(author)
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Matrix-matrix interaction of cartilage oligomeric matrix protein and fibronectin
- 2002
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In: Matrix Biology. - 1569-1802. ; 21:5, s. 461-470
-
Journal article (peer-reviewed)abstract
- Recent work indicates that cartilage oligomeric matrix protein (COMP) plays an important role in extracellular matrix assembly and matrix-matrix protein interactions. In order to identify the proteins in extracellular matrix that interact with COMP, we used an ELISA-based solid-phase binding assay, which revealed a specific, high-affinity interaction between COMP and fibronectin. This interaction is concentration-dependent and saturable, and appears to occur under physiologically relevant conditions. Electron microscopy after negative staining and fragment binding analysis using the solid-phase assay revealed a predominant binding site for the COMP C-terminal globular domain to a molecular domain approximately 14 nm from the N-terminal domain of fibronectin, which can be inhibited by the presence of a polyclonal antibody specific for the C-terminal heptadecapeptide of COMP This interaction is further demonstrated in vivo by colocalization of both COMP and fibronectin in the chondrocyte pericellular matrix by laser confocal microscopy of chondrocytes grown in agarose culture, and by appositional and colocalization of these proteins in the growth plate of primates by immunohistochemistry. (C) 2002 Elsevier Science B.V./International Society of Matrix Biology. Published by Elsevier Science B.V. All rights reserved.
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23. |
- Ding, HT, et al.
(author)
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Parallel cloning, expression, purification and crystallization of human proteins for structural genomics
- 2002
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In: Acta Crystallographica. Section D: Biological Crystallography. - 1399-0047. ; 58, s. 2102-2108
-
Journal article (peer-reviewed)abstract
- 54 human genes were selected as test targets for parallel cloning, expression, purification and crystallization. Proteins from these genes were selected to have a molecular weight of between 14 and 50 kDa, not to have a high percentage of hydrophobic residues (i.e. more likely to be soluble) and to have no known crystal structures and were not known to be subunits of heterocomplexes. Four proteins containing transmembrane regions were selected for comparative tests. To date, 44 expression clones have been constructed with the Gateway(TM) cloning system (Invitrogen, The Netherlands). Of these, 35 clones were expressed as recombinant proteins in Escherichia coli strain BL21 (DE3)-pLysS, of which 12 were soluble and four have been purified to homogeneity. Crystallization conditions were screened for the purified proteins in 96-well plates under oil. After further refinement with the same device or by the hanging-drop method, crystals were grown, with needle, plate and prism shapes. A 2.12 Angstrom data set was collected for protein NCC27. The results provide insights into the high-throughput target selection, cloning, expression and crystallization of human genomic proteins.
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24. |
- Ding, Kan, et al.
(author)
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Copper-dependent autocleavage of glypican-1heparan sulfate by nitric oxide derived fromintrinsic nitrosothiols.
- 2002
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In: Journal of Biological Chemistry. - 1083-351X. ; 277:36, s. 33353-33360
-
Journal article (peer-reviewed)abstract
- Cell-surface heparan sulfate proteoglycans facilitate uptake of growth-promoting polyamines [ [Belting, M., Borsig, L., Fuster, M.M., Brown, J.R., Persson, L., Fransson,L.-. and Esko, J.D. (2002) Proc. Natl. Acad. Sci. U.S.A., 99, 371-376] ]. Increased polyamine uptake correlates with an increased number of positively charged N-unsubstituted glucosamine units in the otherwise polyanionic heparan sulfate chains of glypican-1. During intracellular recycling of glypican-1 there is an NO-dependent deaminative cleavage of heparan sulfate at these glucosamine units, which would eliminate the positive charges [ [Ding, K., Sandgren, S., Mani, K., Belting, M. and Fransson, L.-. (2001) J. Biol. Chem., 276, 46779-46791] ]. Here, using both biochemical and microscopic techniques, we have identified and isolated S-nitrosylated forms of glypican-1 as well as low-charged glypican-1 glycoforms containing heparan sulfate chains rich in N-unsubstituted glucosamines. The latter were converted to high-charged species upon treatment of cells with 1 mM L-ascorbate, which releases NO from nitrosothiols, resulting in deaminative cleavage of heparan sulfate at the N-unsubstituted glucosamines. S-nitrosylation and subsequent deaminative cleavage were abrogated by inhibition of a Cu 2+ /Cu + -redox cycle. Under cell-free conditions, purified, S-nitrosylated glypican-1 was able to autocleave its heparan sulfate chains when NO-release was triggered by L-ascorbate. The heparan sulfate fragments generated in cells during this auto-catalytic process contained terminal anhydromannose residues. We conclude that the core protein of glypican-1 can slowly accumulate NO as nitrosothiols while Cu 2+ is reduced to Cu +. Subsequent release of NO results in efficient deaminative cleavage of the heparan sulfate chains attached to the same core protein while Cu + is oxidized to Cu 2+.
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25. |
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26. |
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27. |
- Fang, AP, et al.
(author)
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Theoretical study of electromagnetically induced transparency in Er3+: YAlO3 crystal
- 2003
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In: Physica B: Condensed Matter. - 0921-4526. ; 328:3-4, s. 204-210
-
Journal article (peer-reviewed)abstract
- By using the density matrix theory of interaction between light and matter, and relevant parameter calculations of the relaxation rate, the dipole matrix elements and the ion density for a three-level ladder model, we have discussed theoretically the possibility to realize electromagnetically induced transparency (EIT) in Er3+:YA1O(3) crystal. (C) 2002 Elsevier Science B.V. All rights reserved.
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28. |
- Fang, Congqi, 1963, et al.
(author)
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Corrosion influence on bond in reinforced concrete
- 2004
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In: Cement and Concrete Research. - : Elsevier BV. - 0008-8846. ; 34:11, s. 2159-2167
-
Journal article (peer-reviewed)abstract
- The bond between reinforcing steel and the surrounding concrete can be deteriorated by corrosion. Pullout tests were carried out to evaluate the effects of corrosion on bond and bond-slip behavior, for a series of specimens with varying reinforcement corrosion levels between 0% and 9%, and for specimens with and without stirrups that provide confinement. Specimens with both smooth and deformed bars were tested. The tests were designed to provide the data required to assess the bond properties, including the ultimate bond strength and free-end slip for various degrees of corrosion under pullout loads. The specimens were tested in an NITS testing machine on which loads, slips and displacements were recorded. Some conclusions have been reached based on the test results.
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29. |
- Fang, Che
(author)
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Cytokines, alcohol metabolizing enzymes and stress-inducible ER proteins in alcoholic liver disease
- 2000
-
Doctoral thesis (other academic/artistic)abstract
- The release of inflammatory cytokines by Kupffer cells is believed to be a key step in the pathogenesis of alcoholic liver disease (ALD). Kupffer cells are activated not only by endotoxins [lipopolysaccharides (LPS)] but also by the lipid peroxidation products generated mainly via ethanol-inducible cytochrome P450 2E1 (CYP2E1) redox cycling. In addition, alcohol dehydrogenase class I (ADH1) is a major enzyme in the first step of ethanol metabolism, whereas induction of endoplasmic reticulum (ER) stress/heat shock proteins as a cellular adaptation in rat model of ALD has been related to the severity of liver injury and lipid peroxidation. The aims of the present studies were to better understand the role of alcohol, endotoxins, Kupffer cells, cytokines, CYP2E1, ADH1 and ER stress proteins in the pathogenesis of ALD. Using a modified competitive PCR and Western blot techniques, we evaluated zonated expression of several cytokines in the liver of rats infused intragastrically with chronic ethanol and the total enteral nutrition. Chronic ethanol treatment significantly increased perivenous expression of transforming growth factor-[beta]1 (TGF-[beta]1) and interleukin-1[beta] (IL-1[beta]) as well as panlobular expression of tumor necrosis factor-cc (TNF-[alpha]) mRNA. Chlormethiazole (CMZ), an inhibitor of CYP2E1 that has been shown to inhibit the development of ALD in this rat model, counteracted the effects of ethanol on the cytokine expression. Rats were treated in an intragastric dietary model with ethanol in a low-carbohydrate/high-fat liquid for 6 weeks. Some rats received LPS infused by minipumps intravenously for 4 weeks. Chronic endotoxin infusion alone resulted in a marked tolerance as judged by insignificant liver damage, increased hepatic expression of both proinflammatory cytokines (TNF-[alpha] and IL-1 [beta]) and anti-inflammatory cytokines (TGF-[beta]1, IL-10 and IL-4), as well as no influence on expression of LPS binding protein and CD14 endotoxin receptor. Additional chronic ethanol enhanced the expression of CYP2E1 protein as well as ADH1 mRNA. An increased pathology score was observed by ethanol, which might be related to an increased ratio of expression of proinflammatory over anti-inflammatory cytokines. Kupffer cell inactivation by Gadolinium chloride alleviated ethanol-induced steatosis as well as CYP2E1 induction, eliminated ED2-positive Kupffer cells, but did not affect inflammation and the expression of TNF-[alpha] and IL-1[beta] as well as the CD 14 receptor. By a combination of direct DNA sequencing with degenerate primer-mediated PCR and RACE, we successfully cloned the cDNA of a novel ERp29 protein from rat liver. Characterization of ERp29 showed that it interacts with ER stress protein BiP/GRP78 and is widely expressed and induced by ER stress. This suggests that ERp29 is functionally related to the major ER stress proteins and may have an important function in protein maturation and the stress defence in ER. Increase of ERp29 protein after chronic LPS exposure further proposes that it may counteract LPS-induced cytotoxicity and contribute to the observed endotoxin tolerance. We found a decrease of ERp29 expression in the Cyp2e1 knockout mice, which suggests possible regulatory relationship between ERp29 and CYP2E1. In conclusion, the present studies suggest that it is important to consider the balance of pro- and anti-inflammatory cytokine expression and different kinds of Kupffer cells in the development of ALD. CYP2E1 is involved in alcohol-induced liver injury, whereas ERp29 may function as a cellular adaptive response to chronic LPS exposure.
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30. |
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31. |
- Fang, Congqi, 1963, et al.
(author)
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The effect of corrosion on concrete bridges
- 2004
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In: Bridge Maintenance, Safety, Management and Cost / edited by Eiichi Watanabe, Dan M. Frangopol, Tomoaki Utsunomiya. - 9058096807
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Conference paper (peer-reviewed)
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32. |
- Fang, Hong
(author)
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Beta-lactam and metronidazole resistance in the Bacteroides fragilis group
- 2001
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Doctoral thesis (other academic/artistic)abstract
- The Bacteroides fragilis group organisms are anaerobic gram-negative bacilli. Ten species are currently included in this group. Members of the B. fragilis group are the major constituents of the normal colonic microflora and the most commonly encountered anaerobic bacteria in clinical specimens. beta-Lactam antibiotics and 5-nitroimidazoles have been extensively used against anaerobic bacteria. However, antibiotic resistance is increasingly common among anaerobic gram-negative bacilli. The classical mechanisms of resistance to beta-lactams are 1) production of beta-lactamases, 2) alteration of penicillinbinding proteins (PBPs), and 3) changes in outer membrane permeability to beta-lactams. The 5nitroimidazole molecule is a prodrug whose activation depends upon reduction of the nitro group in the absence of oxygen. Decreased uptake and altered reduction are believed to be responsible for metronidazole resistance. Five nim genes (A, B, C, D and E) have been identified in the B. fragilis group that confer resistance to 5-nitroimidazole antibiotics. Knowledge of the status and the mechanisms of resistance is critical for both the selection of antimicrobial therapy and the design of new antimicrobial agents. The purpose of this investigation was to study the mechanisms for and the prevalence of beta-lactam and metronidazole resistance in strains belonging to the B. fragilis group. PCR fingerprinting technique was used for characterization of beta-lactam-resistant B. fragilis strains. It was found that the imipenem-resistant B. fragilis strains presented unique PCR fingerprints. These strains produced high amounts of Zn++ dependent beta-lactamases, which were inactivated by EDTA but not by clavulanic acid. The ccrA gene coding for the metallo-beta-lactamase was detected by PCR. The purified PCR products of ccrA from two imipenem-resistant strains were sequenced. The nucleotide sequences of ccrA from these two strains shared >98% identity with the metallo-beta-lactamase gene from a control strain. Production of the metallo-beta-lactamases has been the most perplexing problem over the past 18 years since the first cases of such resistance appeared. These enzymes are capable of hydrolysing all beta-lactam agents except the monobactams, which have no antibacterial activity against Bacteroides, and are not inhibited by the available beta-lactamase inhibitors. The appearance of these enzymes has caused great concern in the clinic. To study the imipenem and metronidazole resistance profiles of B. fragilis group strains in faecal samples and to detect the corresponding resistance genes (ccrA and nim), 925 faecal samples were examined. It was noted that the incidences of imipenem-resistant and metronidazole-resistant B. fragilis group strains were low in the investigated diarrhoea patients. Simultaneous resistance to imipenem and metronidazole was detected, which is of great concern in clinical medicine. The proposed PCR assays may be useful in epidemiological studies on distribution of resistance genes in clinical isolates and in intestinal rnicrofiora. To investigate the mechanisms involved in beta-lactam resistance, two resistant mutants (238m and 1186m) of B. thetaiotaomicron were obtained from clinical isolates (238 and 1186) by selection with increasing concentrations of cefoxitin. The mutant strains showed decreased susceptibilities not only to cefoxitin but also to other beta-lactam antibiotics. Alterations in both penicillin-binding proteins (PBPs) and outer membrane proteins (OMPs) were observed in the mutants as compared to their parent strains. Further investigation found that the growth pattems and the morphological changes induced by cefoxitin were associated with the properties of PBPs The resistant mutants with deficiency in PBPs grew slower than the susceptible parent strains, and cefoxitin caused filamentation at sub-MIC in B. thetaiotaomicron.
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33. |
- Fang, Hong, et al.
(author)
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Effects of cefoxitin on the growth and morphology of Bacteroides thetaiotaomicron strains with different cefoxitin susceptibility
- 2002
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In: Anaerobe. - : Elsevier BV. - 1075-9964 .- 1095-8274. ; 8:2, s. 55-61
-
Journal article (peer-reviewed)abstract
- To examine the effects of cefoxitin on bacterial growth and cell morphology, two pairs of Bacteroides thetaiotaomicron strains (238, 238 m and 1186, 1186 m) with different susceptibilities to this antibiotic were investigated in the present study. B. thetaiotaomicron 238m and 1186m were resistant laboratory mutants originating from the susceptible wild-type strains B. thetaiotaomicron 238 and 1186, respectively. It has been shown, in a previous study, that the mutant strains had alterations in their penicillin-binding proteins (PBPs) as compared to the parent strains. In the present study, strains 238 and 238m presented almost identical genomic fingerprints by PCR, so did strains 1186 and 1186m, which indicates that the parent and mutant strains have similar genomic background. In comparison with the parent strains, the growth rate of mutant strains was slower in cultures without antibiotic. The growth patterns challenged with cefoxitin were also different between the parent and the mutant strains. In case of the morphological responses to cefoxitin, the mutant strains were more resistant to the effect of cefoxitin than the parent strains. In conclusion, the growth patterns and the morphological changes induced by cefoxitin, of the investigated strains, were associated with the properties of PBPs. The resistant mutants with deficiency in PBPs grew slower than the susceptible parent strains, and cefoxitin caused filamentation at sub-MIC in B. thetaiotaomicron.
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34. |
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35. |
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36. |
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37. |
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38. |
- Fang, Hong, et al.
(author)
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Selection of cefoxitin-resistant Bacteroides thetaiotaomicron mutants and mechanisms involved in beta-lactam resistance
- 2002
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In: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1058-4838 .- 1537-6591. ; 35, s. S47-S53
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Journal article (peer-reviewed)abstract
- The beta-lactam antibiotics are the most widely used of all the groups of antimicrobials, but beta-lactam resistance is increasingly common among members of the Bacteroides fragilis group. Three major mechanisms are involved in beta-lactam resistance, and they act together in certain instances. In the present study, 2 resistant mutants (238m and 1186m) of Bacteroides thetaiotaomicron, obtained from clinical isolates (238 and 1186) by selection with increasing concentrations of cefoxitin, showed decreased susceptibilities to cefoxitin and other beta-lactam antibiotics. Alterations in both penicillin-binding proteins (PBPs) and outer-membrane proteins (OMPs) were observed in the mutants in comparison with their parent strains. The similar alteration in OMPs was also observed in clinical isolates. In conclusion, the beta-lactam-resistant mutants of B. thetaiotaomicron with deficiency in both PBPs and OMPs can be selected for by exposure to cefoxitin, and several mechanisms are involved in the beta-lactam resistance in the strains investigated.
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39. |
- Fang, Tony
(author)
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A critique of Hofstede’s fifth national culture dimension
- 2003
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In: International Journal of Cross Cultural Management. - : SAGE Publications. - 1470-5958 .- 1741-2838. ; 3:3, s. 347-368
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Journal article (peer-reviewed)abstract
- Using indigenous knowledge of Chinese culture and philosophy, this article critiques Geert Hofstede’s fifth national culture dimension, i.e. ‘Confucian dynamism’, also referred to as ‘long-term orientation’. The basic premise on which the dimension is founded is scrutinized and the way in which this index has been constructed is assessed in detail. It is argued that there is a philosophical flaw inherent in this ‘new’ dimension. Given this fatal flaw and other methodological weaknesses, the usefulness of Hofstede’s fifth dimension is doubted. The article concludes by calling for new visions and perspectives in our cross cultural research.
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40. |
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41. |
- Fang, Tony
(author)
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Culture as a driving force for interfirm adaptation: A Chinese case
- 2001
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In: Industrial Marketing Management. - 0019-8501 .- 1873-2062. ; 30:1, s. 51-63
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Journal article (peer-reviewed)abstract
- The concept of interfirm adaptation is a critical component in the IMP (industrial marketing and purchasing) paradigm. The existing wisdom points to the “five metaphors” (investment, decision making, political process, learning, and evolution) as the cognitive map for understanding the mechanisms of interfirm adaptations. This article, however, reveals that culture can be a significant force driving interfirm adaptations. An empirical case of a Chinese shipyard negotiating large shipbuilding projects with Scandinavian ship owner and classification society is used to illustrate the role that culture plays in interfirm adaptations. The article concludes by suggesting adding a new metaphor—the culture metaphor—to the list of the metaphors to better understand the workings of interfirm adaptation in business relationships.
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42. |
- Fang, Tony
(author)
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The "coop-comp" Chinese negotiation strategy
- 2003
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In: Trust and antitrust in Asian business alliances. - Basingstoke : Palgrave Macmillan. - 9780230523579 ; , s. 121-150
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Book chapter (other academic/artistic)
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43. |
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44. |
- Fang, Tony
(author)
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The moon and the sun of culture.
- 2004
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In: The Academy of International Business (AIB), Competitive Paper. Stockholm, July 10-13..
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Conference paper (other academic/artistic)
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45. |
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46. |
- Fang, Tony, et al.
(author)
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Why did the Telia-Telenor merger fail?
- 2004
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In: International Business Review. - : Elsevier BV. - 0969-5931 .- 1873-6149. ; 13:5, s. 573-594
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Journal article (peer-reviewed)abstract
- The purpose of this article is to examine through a case study of the merger of Telia–Telenor why firms from apparently similar national cultures can fail to form a co-operative venture. Telia and Telenor were the largest telecom operators in Sweden and Norway, respectively. Both were government-owned with a strong monopoly over their respective national markets for a long time. Despite perceived similarities between the negotiating parties in national culture, corporate practice, and language, the negotiation eventually went askew and the ongoing merger ended in December 1999 after only two months in existence. We describe the process of the Telia–Telenor merger negotiation and analyze it from a cross-cultural management perspective. Our major finding is that historical sentiments, feelings and emotions, if not handled well, can cause fatal damage to cross-cultural business ventures.
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47. |
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48. |
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49. |
- Fransson, Lars-Åke, et al.
(author)
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Novel aspects of glypican glycobiology.
- 2004
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In: Cellular and Molecular Life Sciences. - : Springer Science and Business Media LLC. - 1420-9071 .- 1420-682X. ; 61:9, s. 1016-1024
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Research review (peer-reviewed)abstract
- Mutations in glypican genes cause dysmorphic and overgrowth syndromes in men and mice, abnormal development in flies and worms, and defective gastrulation in zebrafish and ascidians. All glypican core proteins share a characteristic pattern of 14 conserved cysteine residues. Upstream from the C-terminal membrane anchorage are 3–4 heparan sulfate attachment sites. Cysteines in glypican-1 can become nitrosylated by nitric oxide in a copper-dependent reaction. When glypican-1 is exposed to ascorbate, nitric oxide is released and participates in deaminative cleavage of heparan sulfate at sites where the glucosamines have a free amino group. This process takes place while glypican-1 recycles via a nonclassical, caveolin-1-associated route. Glypicans are involved in growth factor signalling and transport, e.g. of polyamines. Cargo can be unloaded from heparan sulfate by nitric oxide-dependent degradation. How glypican and its degradation products and the cargo exit from the recycling route is an enigma.
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50. |
- Fu, Zhan, et al.
(author)
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Evaluation of the difference between the driving behaviour of a Speech based and a speech-visual based task of an in-car computer
- 2004
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In: The 8th International Conference on Spoken Language Processing, Interspeech 2004, ICSL. Jeju Island, Korea.
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Conference paper (peer-reviewed)abstract
- To select the right modality for the interaction between drivers and the in-vehicle information system (IVIS) is crucial for safety reasons. This paper presents an experimental study to dress on this subject. The study was carried out on a 160 degree car-driving simulation lab. There are 10 subjects participated in the experiment. We compared the subjects driving behavior on speech input/output only and speech input with speech+visual output interaction modalities with a simple IVIS. To judge the safety status of subjects driving performance, two independent variables which includes the average division of over speed and the average division of the car out of lane were measured as dangerous extent. Result indicates that it is not significant differences of driving performance by using synthetic speech to replace the visual display in the IVIS. It indicated that the visual presentation of a multi-modal IVIS can be acts as redundancy or complementary modality for auditory presentation, which will aids in relieving the resource demand.
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