| 1. |
- Chen, Q, et al.
(author)
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Identification of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) as the rosetting ligand of the malaria parasite P. falciparum
- 1998
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In: The Journal of experimental medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 187:1, s. 15-23
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Journal article (peer-reviewed)abstract
- Severe Plasmodium falciparum malaria is characterized by excessive sequestration of infected and uninfected erythrocytes in the microvasculature of the affected organ. Rosetting, the adhesion of P. falciparum–infected erythrocytes to uninfected erythrocytes is a virulent parasite phenotype associated with the occurrence of severe malaria. Here we report on the identification by single-cell reverse transcriptase PCR and cDNA cloning of the adhesive ligand P. falciparum erythrocyte membrane protein 1 (PfEMP1). Rosetting PfEMP1 contains clusters of glycosaminoglycan-binding motifs. A recombinant fusion protein (Duffy binding-like 1–glutathione S transferase; Duffy binding-like-1–GST) was found to adhere directly to normal erythrocytes, disrupt naturally formed rosettes, block rosette reformation, and bind to a heparin-Sepharose matrix. The adhesive interactions could be inhibited with heparan sulfate or enzymes that remove heparan sulfate from the cell surface whereas other enzymes or similar glycosaminoglycans of a like negative charge did not affect the binding. PfEMP1 is suggested to be the rosetting ligand and heparan sulfate, or a heparan sulfate–like molecule, the receptor both for PfEMP1 binding and naturally formed erythrocyte rosettes.
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| 2. |
- Hallböök, F, et al.
(author)
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Characterization and evaluation of NGF antisense oligonucleotides : inhibition of NGF synthesis in transfected COS cells.
- 1997
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In: Antisense and Nucleic Acid Drug Development. - 1087-2906 .- 2168-6599. ; 7:2, s. 89-100
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Journal article (peer-reviewed)abstract
- We present a system for the assessment of the inhibiting capacity of antisense oligonucleotides. The aim of this study was to identify an oligonucleotide that can inhibit chicken nerve growth factor (NGF) synthesis. Five antisense chicken NGF phosphorothioate oligonucleotides, AS1-5, were designed and were tested for their capacity to inhibit NGF expression in COS cells. COS cells that transiently expressed chicken NGF were treated with the oligonucleotides, and NGF expression was analyzed using a bioassay and Western blotting for NGF protein. Two oligonucleotides, AS 1 and AS 5, were more capable than the others of inhibiting expression compared with nonsense oligonucleotide, and they targeted the translational initiation and stop sites. The chicken NGF is expressed at a high level from an adenovirus major late promoter, and AS 1 was capable of inhibiting more than 80% of the NGF expression as determined using the bioassay and Western blotting. Expression of another member of the NGF gene family, neurotrophin-4, was not affected by treatment of the antisense oligonucleotides. A 10-fold lower concentration of the AS 1 oligonucleotide could be used to inhibit NGF synthesis if the cellular uptake was facilitated using lipofectin compared with addition of oligonucleotide directly to the culture medium. The amount of oligonucleotide taken up by the cells was similar in the lipofectin-treated cells as in the cells treated by a 10-fold higher concentration of medium-supplemented nucleotide. This system based on COS cells can facilitate evaluation of the capacity of inhibiting antisense oligonucleotides, particularly targeting those genes in which endogenous products are present in low levels and are difficult to analyze.
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| 3. |
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| 4. |
- Skagerlund, J., et al.
(author)
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Evaluation of an automatic method to extract the grating coupling coefficient in different types of fabricated DFB lasers
- 1998
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In: IEEE Journal of Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9197 .- 1558-1713. ; 34, s. 141-146
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Journal article (peer-reviewed)abstract
- Distributed feedback (DFB) laser parameters such as grating coupling coefficient, effective indices, facet reflectances, and the phases of facet reflectances have been determined using a method based on least-square fitting of theoretical spectra to measured, subthreshold DFB laser emission spectra. The only inputs needed are geometrical parameters such as length, grating period, and internal grating phase shifts. A larger number of devices have been successfully characterized, and consistent results have been obtained in both 1.3- mu;m multi-quantum-well (MQW) DFB lasers with both facets as-cleaved, and in 1.55- mu;m MQW DFB lasers with no, one, or two facets as-cleaved
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| 5. |
- Trollsås, M., et al.
(author)
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The influence of the molecular structure on the second-order nonlinear optical properties of pyroelectric liquid crystalline polymers
- 1998
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In: American Chemical Society Symposium Series (ACS). - Washington, DC : American Chemical Society. - 0097-6156 .- 1947-5918. ; 695, s. 315-327
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Journal article (peer-reviewed)abstract
- Pyroelectric Liquid Crystal Polymers (PLCP), a novel class of material with intrinsic polar order developed in our laboratory, are discussed. Thin films (2-4µm) of PLCP were prepared by photopolymerization of ferroelectric liquid crystalline monomers in the chiral smectic C (SmC*) phase. The poly(acrylate) materials have been structurally modified in order to improve their nonlinear optical and thermal properties. Further are their longterm nonlinear optical properties discussed based on results from second harmonic generation (SHG), spontaneous polarization (Ps), and dielectric spectroscopy.
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