| 1. |
- Andersson-Engels, S., et al.
(författare)
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A Comparison of tumor demarcation potential for various hematoporphyrin derivatives and phtalocyanine using laser-induced fluorescence
- 1988
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X. ; 907, s. 80-86
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Konferensbidrag (refereegranskat)abstract
- Laser-induced fluorescence data for rats injected with the different tumor-marking drugs, dihematoporphyrin ether, poly hematoporphyrin esters, hematoporphyrin and phtalocyanine, are presented. Studies were performed at two different excitation wavelengths. Comparisons between the different drugs are made with regard to fluorescence intensity and tumor demarcation capability. Further, the origin of the differences in fluorescence characteristics is briefly di scussed.
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| 2. |
- Andersson-Engels, S., et al.
(författare)
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Tissue diagnostics using laser-induced fluorescence
- 1989
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Ingår i: Berichte der Bunsengesellschaft für Physikalische Chemie. - : Wiley. - 0005-9021. ; 93:3, s. 335-342
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Tidskriftsartikel (refereegranskat)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. |
- Andersson-Engels, S., et al.
(författare)
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Aspects of tumour demarcation in rats by means of laser-induced fluorescence and haematoporphyrin derivatives
- 1988
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Ingår i: Lasers in Medical Science. - 0268-8921. ; 3:239, s. 239-248
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Tidskriftsartikel (refereegranskat)abstract
- The effects of different parameters of interest for the localization of malignant tumours in situ by means of laser-induced fluorescence and haematoporphyrin derivatives were investigated. Such parameters are drug composition, drug concentration, laser pulse energy and excitation wavelength. In order to assess the relative merits of the two tumour-seeking agents Photofrin (haematoporphyrin derivative) and Photofrin II (dihaematoporphyrin ether) we have performed a comparative study on rat tissues. The results suggest that Photofrin is at least as good as the therapeutically more potent agent Photofrin II. A linear relation between drug dose and recorded porphyrin fluorescence intensity was also found. Using not only the porphyrin fluorescence, but also natural tissue autofluorescence, better tumour demarcation is observed when utilizing an excitation wavelength shorter than the porphyrin excitation peak at 405 nm.
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| 4. |
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| 5. |
- Andersson-Engels, Stefan, et al.
(författare)
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Tumour marking properties of different haematoporphyrins and tetrasulfonated phthalocyanine - A comparison
- 1989
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Ingår i: Lasers in Medical Science. - 0268-8921. ; 4:2, s. 115-123
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Tidskriftsartikel (refereegranskat)abstract
- Several photosensitizers were screened for their tumour-marking ability using laserinduced fluorescence in Wistar/Furth rats bearing subcutaneous adenocarcinomas inoculated in muscle. Of the studied photosensitizers, dihaematoporphyrin ether appeared to exhibit the best tumour-demarcation properties. Polyhaematoporphyrin ester and tetrasulfonated phthalocyanine were almost as good although the fluorescence yield was much lower. Monomeric haematoporphyrin also showed some tumour-marking qualities. By forming fluorescence intensity ratios, information from both the blue and the red spectral regions were used to provide the highest tumour-to-muscle contrast. Two excitation wavelengths were used, of which 337 nm rather than 405 nm excitation light seemed to yield a better tumour demarcation, due to a greater difference in the superimposing autofluorescence between tumour and surrounding tissue. The study included measurements on many inner organs in an attempt to gain a better understanding of the interaction between the drugs and various kinds of tissue.
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| 6. |
- Andersson, P. S., et al.
(författare)
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TISSUE CHARACTERIZATION USING LASER-INDUCED FLUORESCENCE.
- 1987
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Ingår i: Conference on Lasers and Electro-Optics. - 0936659491 ; 14, s. 46-48
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Konferensbidrag (refereegranskat)abstract
- In cancer tumor detection, tissue autofluorescence and characteristic features of injected hematoporphyrin derivative (HPD) can be utilized. The authors have studied the importance of the excitation wavelength for the achievable contrast between tumor and surrounding tissue using a rat tumor model. They have also compared the relative merits of two HPD preparations for tumor fluorescence detection. The real-time capability of the fluorescence technique is discussed.
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| 7. |
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| 8. |
- Ankerst, J., et al.
(författare)
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Decreased responsiveness to immune complexes of granulocytes from patients with acute leukemia in remission demonstrated by microcalorimetry
- 1984
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Ingår i: Leukemia Research. - : Elsevier BV. - 0145-2126. ; 8:6, s. 997-1002
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Tidskriftsartikel (refereegranskat)abstract
- Functional activity of granulocytes from healthy individuals and from patients with acute leukemia in remission was studied. The increase of heat production rate (metabolic activity) after stimulation of the blood cells with in vitro formed immune complexes was measured by microcalorimeters of heat conduction type. It was demonstrated that increased heat production rate after exposure to immune complexes was significantly lower (p<0.0005) in 9 patients with acute leukemia with a remission duration of less than 6 months than in 25 healthy volunteers.
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| 9. |
- Ankerst, J, et al.
(författare)
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Laser-induced Fluorescence Studies of Hematoporphyrin Derivative (hpd) In Normal and Tumor-tissue of Rat
- 1984
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Ingår i: Applied Spectroscopy. - : SAGE Publications. - 1943-3530 .- 0003-7028. ; 38:6, s. 890-896
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Tidskriftsartikel (refereegranskat)abstract
- Fluorescence studies of hematoporphyrin derivative (HPD) in normal and tumor tissue of rat were performed with nitrogen laser excitation and optical multi-channel detection. Fifteen types of tissue including inoculated tumor were investigated for rats at different delays after HPD injection. Optimum contrast functions and other criteria for discriminating tumor tissue from normal tissue are discussed. The results should have implications for practical human HPD endoscopy.
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| 10. |
- Ankerst, J., et al.
(författare)
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Microcalorimetry as a tool for the detection of complement-dependent cytotoxicity
- 1985
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Ingår i: Journal of Immunological Methods. - : Elsevier BV. - 0022-1759. ; 77:2, s. 267-274
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Tidskriftsartikel (refereegranskat)abstract
- Microcalorimetry using a 4-channel static ampoule microcalorimeter of thermopile type has been evaluated as a tool for the detection of complement-dependent cytotoxicity against the surface antigens of living cells. Cytotoxic reactions mediated by a rabbit antiserum against human white blood cells and by 2 different monoclonal antibodies recognizing a melanoma-associated antigen on a human melanoma cell line were studied. The cytotoxic reactions were registered as a decrease of the heat production rate when the cells were exposed to antibodies in the presence of active complement as compared to the heat production rate of the cells exposed to the same antibodies in the presence of inactive complement. This investigation shows that microcalorimetry can be used as a highly sensitive method for the detection of complement-dependent immune reactions, detecting antibody dilutions higher than 10-5. It also indicates that microcalorimetry may become a particularly important technique in the analysis of the kinetics of cytotoxic immune reactions in vitro.
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