| 1. |
- Malmqvist, K. G., et al.
(author)
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PIXE and proton microprobe advances at the Lund Institute of Technology
- 1989
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In: Nuclear Inst. and Methods in Physics Research, B. - 0168-583X. ; 40-41:PART 1, s. 685-689
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Journal article (peer-reviewed)abstract
- A review of recent advances in high-energy ion beam analysis at the Lund Institute of Technology is presented. A nonvacuum specimen chamber allows chemical speciation using a combination of ion beam analysis and controlled heating. The development of a new versatile scanning proton microbeam based on a new dedicated accelerator, an achromatic triplet lens and an advanced specimen chamber is outlined together with the performance of a microVAX-II/VMEbus-based data acquisition system.
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| 2. |
- Andersson-Engels, S., et al.
(author)
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Tissue diagnostics using laser-induced fluorescence
- 1989
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In: Berichte der Bunsengesellschaft für Physikalische Chemie. - : Wiley. - 0005-9021. ; 93:3, s. 335-342
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Journal article (peer-reviewed)abstract
- We have performed extensive investigations of laser-induced fluorescence in animal and human tissue aimed at instant tissue characterization. Autofluorescence, as well as specific fluorescence from HPD/DHE and other photosensitizers, has been utilized. The studies have been focused on the demarcation of malignant tumours and atheroscleortic plaques. A nitrogen laser or an excimer-pumped dye laser was used to induce fluorescence, which was analysed with an intensified optical multichannel system. A fibre-optic sensor system was developed for the clinical work. Multi-colour fluorescence imaging has also been demonstrated along a line and equipment for two-dimensional imaging is being constructed. Dimensionless spectroscopic functions, which are not affected by factors that are clinically uncontrollable have been employed for optimum tissue discrimination. The investigations have so far been performed in a time-integrated mode, but time-resolved studies are now being initiated to fully exploit the diagnostic power of tissue laser-induced fluorescence. In addition to a presentation of our own work a brief review of tissue fluorescence studies performed by other groups is also given.
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| 3. |
- Johansson, Hugo, et al.
(author)
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Herpes simplex type 1-induced Fc receptor binds to the Cgamma2-Cgamma3 interface region of IgG in the area that binds staphylococcal protein A
- 1989
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In: Immunology. - 0019-2805. ; 66:1, s. 8-13
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Journal article (peer-reviewed)abstract
- The binding site of immunoglobulin G (IgG) to herpes simplex virus (HSV) type 1-induced Fc receptor was investigated using human IgG Fc intermediate (Fc(i)) fragments, fragment D of staphylococcal protein A (SPA) and chemically modified human IgG. Human IgG Fc(i) fragment composed of one Cgamma2 and two Cgamma3 domains, bound strongly to HSV-1-infected cells. Fragment D, a monovalent subunit of SPA, inhibited the binding of radiolabelled human IgG Fc fragments to the HSV Fc receptor. Reductively methylated human IgG reacted equally well to HSV-infected cells, as did chemically unmodified IgG in contrast to N-acetylimidazole-modified and diethylpyrocarbonate-modifed human IgG, which were unreactive. These results suggest a similar binding site on human IgG for SPA and the HSV-1 Fc receptor with involvement of the amino acid residues Tyr and His but not Lys. The similarities of binding sites on the IgG molecule for the HSV-1 Fc receptor and rheumatoid factors (RF) may be important for understanding the mechanism of RF production in rheumatoid arthritis or other disease states.
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| 4. |
- Johansson, Hugo, et al.
(author)
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Interaction between herpes simplex type 1-induced Fc receptor and human and rabbit immunoglobulin G (IgG) domains
- 1986
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In: Immunology. - 0019-2805. ; 58:2, s. 251-255
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Journal article (peer-reviewed)abstract
- Cells infected with herpes simplex virus type 1 (HSV-1) express a cell surface receptor able to bind to the Fc region of immunoglobulin G (IgG). The ability of HSV-1-infected cells to bind 125I-labelled human and rabbit IgG and IgG fragments was studied to localize the site of interaction to the C gamma 2 or C gamma 3 domains of IgG. 125I-labelled IgG and IgG Fc fragments consisting of C gamma 2 and C gamma 3 domains bound strongly to HSV-infected cells and did not bind to uninfected cells. In contrast, 125I-labelled F(ab')2, Facb [consisting of F(ab')2 and C gamma 2 domains] and pFc' (consisting of C gamma 3 domains) fragments did not bind to any of these cells. Unlabelled IgG and IgG Fc fragments inhibited the interaction between 125I-labelled rabbit IgG Fc and the HSV Fc receptor, whereas F(ab')2, Facb and pFc' fragments failed to inhibit this interaction. These data indicate that the HSV Fc receptor requires both the C gamma 2 and C gamma 3 domains for interaction with the IgG molecule analogous to the known interaction of protein A of Staphylococcus aureus, the Fc binding proteins of Group A, C and G streptococci, and certain human rheumatoid factors.
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| 5. |
- Levin, J.C., et al.
(author)
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Production of very cold, highly charged ions by synchrotron radiation: Comparisons of the “scalpel” and “hammer” methods
- 1987
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In: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 262:1, s. 106-109
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Journal article (peer-reviewed)abstract
- Measurements of kinetic energies of highy charged argon ions produced by inner-shell photoionization and by ion-beam impact have been made using time-of-flight techniques. High-charge-state recoil ions produced by beams of ∼ 0.5-1 MeV/u Cl5+ are found to have energies one to two orders of magnitude higher than ions of the same charge produced by vacancy cascades following inner-shell photoionization by synchrotron radiation. The results may have application to the development of a very cold ion source useful for angle-resolved atomic collision studies.
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| 6. |
- Nardella, F A, et al.
(author)
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Fc epitopes for human rheumatoid factors and the relationships of rheumatoid factors to the Fc binding proteins of microorganisms
- 1988
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In: Scandinavian Journal of Rheumatology. Supplement. - : Informa UK Limited. - 1502-7740 .- 0300-9742 .- 1502-7732. ; 17:Suppl. 75, s. 190-198
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Journal article (peer-reviewed)abstract
- Work from our laboratories has shown that the major antigenic determinants for rheumatoid factors (RFs) are in the C gamma 2-C gamma 3 interface region of IgG in the same area that binds staphylococcal protein A (SPA). Furthermore, the Fc binding proteins of groups A, C and G streptococci as well as the Fc binding proteins induced on cell surfaces by herpes simplex virus type I also bind to the same area of IgG. These binding site similarities between RFs and the microbial Fc binding proteins suggested conformational similarities between the RF antigen combining regions and the Fc binding regions of the microbial proteins. This hypothesis was supported by the observation that antibodies to SPA bind to the antigen combining regions of most RFs as well as to the Fc binding region of the T15 group A streptococcal Fc binding protein. These findings indicate that RFs bear the conformational internal image of these microbial proteins and suggest that RFs could arise as antibodies to the idiotypic determinants on antibodies to microbial Fc binding proteins. Alternatively, microbial Fc binding proteins could present IgG to the immune system in a way that renders specific areas of the C gamma 2-C gamma 3 interface region immunogenic. These relationships between RFs and microbial Fc binding proteins may prove to be important for our understanding of the generation of RFs in rheumatoid arthritis.
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| 7. |
- Schröder, A K, et al.
(author)
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Binding of monoclonal IgM rheumatoid factor to streptococci via the antibody combining site
- 1987
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In: International Archives of Allergy and Applied Immunology. - 0020-5915. ; 83:1, s. 88-91
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Journal article (peer-reviewed)abstract
- Radiolabelled monoclonal IgM rheumatoid factors, four from patients with type II essential cryoglobulinaemia and one originating from a patient with rheumatoid arthritis, were tested for binding to group A, B, C and G streptococci and Escherichia coli. Two of the preparations exhibited different binding patterns for the streptococci, whereas the remaining three were not reactive. The binding of one of the factors to group A streptococci type 15 was inhibited by F(ab')2-fragments of anti-idiotypic antibodies but not anti-IgM Fc or F(ab')2 of normal rabbit IgG, indicating that the reaction was mediated via the antibody combining sites.
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| 8. |
- Schröder, A K, et al.
(author)
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Identification of the site on IgG Fc for interaction with streptococci of groups A, C and G
- 1987
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In: Immunology. - 0019-2805. ; 62:4, s. 523-527
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Journal article (peer-reviewed)abstract
- The interaction between living groups A, C and G streptococci and IgG Fc was studied using human IgG, IgG Fc and IgG Fc-intermediate (Fci) fragments, chemically modified human IgG and fragment D of staphylococcal protein A (SPA). Diethylpyrocarbonate modification of His or N-acetylimidazole modification of Tyr of human IgG resulted in the loss of its capacity to inhibit the binding of radiolabelled human IgG Fc to the group A streptococci types M1 and M55, and to the group C strain SC-1, indicating that the amino acids His and Tyr are involved in the binding. Lys seems not to participate in the binding of IgG to these bacteria, however, since reductive methylation of Lys did not reduce its inhibitory capacity. Fragment D of SPA also inhibited the binding of radiolabelled human IgG Fc to strains M1, M55 and SC-1. We have previously shown that these bacteria do not bind to IgG fragments consisting of only the C gamma 2 or C gamma 3 domains. On the basis of these results, and the known relative positions in space of the His and Tyr residues on IgG Fc, it is speculated whether streptococci with IgG Fc receptors, like SPA and rheumatoid factors, interact with IgG in the interface between the C gamma 2 and C gamma 3 domains and involve His 435 and one or more of Tyr 436, His 433 and His 310. The similarities in binding sites on IgG for RFs and these bacterial Fc binding proteins suggest structural similarities between them that may be relevant to the production of rheumatoid factors in rheumatoid arthritis.
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| 9. |
- Short, R. T., et al.
(author)
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Production of very-low-energy highly charged ions by synchrotron radiation
- 1986
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In: Physical Review Letters. - 1079-7114. ; 56:24, s. 2614-2617
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Journal article (peer-reviewed)abstract
- Very-low-energy highly charged ions have been produced by use of white and monochromatic x rays from a wiggler line at the Stanford Synchrotron Radiation Laboratory to generate vacancy cascades following inner-shell photoionization. Recoil-ion energies have been determined and are shown to correspond essentially to room temperatures, even for high charge states. Promising applications to study of the interaction of stellar radiation with cold matter, to high-brightness ionsource development, to precision spectroscopy, and to angle-resolved chemical-physics reactive-scattering studies are discussed.
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| 10. |
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