| 1. |
- Wahlgren, M, et al.
(författare)
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Adhesion of Plasmodium falciparum-infected erythrocytes to human cells and secretion of cytokines (IL-1-beta, IL-1RA, IL-6, IL-8, IL-10, TGF beta, TNF alpha, G-CSF, GM-CSF
- 1995
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Ingår i: Scandinavian journal of immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 42:6, s. 626-636
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Brandt, JC, et al.
(författare)
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A Goddard High Resolution Spectrograph atlas of echelle observations of the HgMn star chi Lupi
- 1999
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Ingår i: The Astronomical Journal. - : American Astronomical Society. - 1538-3881 .- 0004-6256. ; 117:3, s. 1505-1548
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Tidskriftsartikel (refereegranskat)abstract
- Observations of the ultra-sharp-lined, chemically peculiar star chi Lupi taken by the Goddard High Resolution Spectrograph in echelle mode are presented. Thirty-six intervals of the spectral region between 1249 and 2688 Angstrom are covered with resolving powers in the range 75,000-93,000. Line identifications are provided, and the observed spectra are compared with synthetic spectra calculated using the SYNTHE program and associated line lists with changes to the line lists. The significance of these spectra for the chi Lupi Pathfinder Project and the closely related atomic physics effort is discussed in a companion paper.
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| 3. |
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| 4. |
- Chen, Q, et al.
(författare)
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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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Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 187:1, s. 15-23
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Tidskriftsartikel (refereegranskat)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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| 5. |
- Fernandez, V, et al.
(författare)
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Small, clonally variant antigens expressed on the surface of the Plasmodium falciparum-infected erythrocyte are encoded by the rif gene family and are the target of human immune responses
- 1999
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Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 190:10, s. 1393-1403
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Tidskriftsartikel (refereegranskat)abstract
- Disease severity in Plasmodium falciparum infections is a direct consequence of the parasite's efficient evasion of the defense mechanisms of the human host. To date, one parasite-derived molecule, the antigenically variant adhesin P. falciparum erythrocyte membrane protein 1 (PfEMP1), is known to be transported to the infected erythrocyte (pRBC) surface, where it mediates binding to different host receptors. Here we report that multiple additional proteins are expressed by the parasite at the pRBC surface, including a large cluster of clonally variant antigens of 30–45 kD. We have found these antigens to be identical to the rifins, predicted polypeptides encoded by the rif multigene family. These parasite products, formerly called rosettins after their identification in rosetting parasites, are prominently expressed by fresh isolates of P. falciparum. Rifins are immunogenic in natural infections and strain-specifically recognized by human immune sera in immunoprecipitation of surface-labeled pRBC extracts. Furthermore, human immune sera agglutinate pRBCs digested with trypsin at conditions such that radioiodinated PfEMP1 polypeptides are not detected but rifins are detected, suggesting the presence of epitopes in rifins targeted by agglutinating antibodies. When analyzed by two-dimensional electrophoresis, the rifins resolved into several isoforms in the pI range of 5.5–6.5, indicating molecular microheterogeneity, an additional potential novel source of antigenic diversity in P. falciparum. Prominent polypeptides of 20, 22, 76–80, 140, and 170 kD were also detected on the surfaces of pRBCs bearing in vitro–propagated or field-isolated parasites. In this report, we describe the rifins, the second family of clonally variant antigens known to be displayed by P. falciparum on the surface of the infected erythrocyte.
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| 6. |
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| 7. |
- Sikstrom, C. M, et al.
(författare)
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New Zr II oscillator strengths and the zirconium conflict in the HgMn star chi Lupi
- 1999
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Ingår i: Astronomy & Astrophysics. - 0004-6361. ; 343:1, s. 297-302
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Tidskriftsartikel (refereegranskat)abstract
- Lifetimes on the sub-nanosecond scale for the levels v(2)D(3/2), v(2)F(3/2) and v(2)F(5/2) in the 4d5s5p configuration in Zr II have been measured, using the method of laser-induced fluorescence. Combined with branching fractions obtained with the Lund Ultraviolet (UV) Fourier Transform Spectrometer (FTS), experimental oscillator strengths have been derived. From Hubble Space Telescope/Goddard High-Resolution Spectrograph spectra, the zirconium abundance in the HgMn star chi Lupi has been determined from Zr II and Zr III lines. More than an order of magnitude difference in the Zr II abundance has been derived from these ionization stages. The difference is much too large to be explained by uncertainties in the oscillator strengths. Possible explanations of this difference have to be found in the stellar models, such as the influence of non-LTE or diffusion.
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| 8. |
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| 9. |
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| 10. |
- Barragan, A, et al.
(författare)
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Plasmodium falciparum: molecular background to strain-specific rosettedisruption by glycosaminoglycans and sulfated glycoconjugates
- 1999
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Ingår i: Experimental parasitology. - : Elsevier BV. - 0014-4894 .- 1090-2449. ; 91:2, s. 133-143
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Tidskriftsartikel (refereegranskat)abstract
- Rosetting, the adhesion of Plasmodium falciparum-infected erythrocytes to uninfected erythrocytes, is a virulent parasite phenotype associated with the occurrence of severe malaria, e.g., cerebral malaria. Compounds with specific anti-rosetting activity are potential therapeutic agents. Glycosaminoglycans and sulfated glycoconjugates were found to disrupt rosettes in a strain- and isolate-specific manner. Rosette disruption was strongly connected to the presence of N-sulfate groups in heparin/heparan sulfate as demonstrated by modified heparin preparations. This finding was corroborated by the disruption of rosettes with mono- and disaccharides derived from heparin/heparan sulfate that contained N-sulfated glucosamine. Furthermore, heparinase III treatment of erythrocyte cultures infected by FCR3S1 (and to some extent TM 284) P. falciparum strains abolished rosetting. Heparinase III treatment of the uninfected erythrocytes prior to mixing with the infected culture impeded formation of rosettes, indicating that the rosetting receptors at least partially are of glycosaminoglycan nature.
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