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- Braide, M, et al.
(author)
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Migration of human granulocytes in filters: effects of gravity and movable gradients of f-MLP
- 1994
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In: Biorheology. - THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB : PERGAMON-ELSEVIER SCIENCE LTD. - 0006-355X .- 1878-5034. ; 31:6, s. 617-630
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Journal article (peer-reviewed)abstract
- The Boyden chamber technique for chemotaxis uses a mesh filter that constitutes a matrix for cell locomotion and, at the same time, creates a local restriction for convective fluid movements that allows the establishment of a diffusive concentration gradient of chemotactic substance in the filter. In the present study, the Boyden chamber was modified by the introduction of a filter sandwich that allowed cell migration both upwards and downwards and by the use of a fluid density gradient controlling cell buoyancy and mechanically supporting a movable chemotactic gradient. This method was used to study chemotaxis and random migration of human granulocytes under the influence of gravitational forces and movable gradients of f-MLP. The results show that gravity affected cell motion significantly during random migration but not during chemotaxis. The rate of chemotactic migration was dependent on the steepness of the spatio-temporal f-MLP gradients. A stationary spatial gradient produced less migration than a gradient that was slowly moved through the filter sandwich in a direction opposite to that of the cell migration. The presence of f-MLP at constant concentration caused a minor, statistically insignificant, increase of the rate of random migration.
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| 2. |
- Holgers, K M, et al.
(author)
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Clinical, immunological and bacteriological evaluation of adverse reactions to skin-penetrating titanium implants in the head and neck region
- 1992
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In: Contact Dermatitis. - : Wiley. - 0105-1873. ; 27:1, s. 1-7
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Journal article (peer-reviewed)abstract
- Between 1977 and October 1989, 445 patients have been treated with bone-anchored skin-penetrating titanium implants for anchorage of facial prostheses or bone-conducting hearing aids, at the Ear, Nose and Throat Department at Sahlgren's Hospital in Gothenburg. The majority of patients had no adverse skin reactions, while a few patients were responsible for the majority of the adverse reactions. The aim of our study was to analyse differences between these groups. We started a clinical study on 9 patients with a clinical history of adverse skin reactions around the titanium implants and 9 patients without adverse skin reactions were used as controls. None of the patients had delayed hypersensitivity to titanium. Microbiological analyses showed that when there was clinical irritation, Staphylococcus aureus could be isolated.
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| 3. |
- Löfgren, Anders, et al.
(author)
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Copolymers of 1,5-dioxepan-2-one and L- or D,L-dilactide: in vivo degradation behaviour
- 1994
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In: Journal of Biomaterials Science. Polymer Edition. - 0920-5063. ; 6:5, s. 411-423
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Journal article (peer-reviewed)abstract
- Copolymers of 1,5-dioxepan-2-one (DXO) and L- or D,L-dilactide have been synthesized and characterized. The molar ratio of the two monomers was around 20/80 of DXO and L- or D,L-lactide respectively. In vivo studies on rats revealed significant differences in tissue response between the semicrystalline DXO/L-LA copolymer and the amorphous DXO/D,L-LA copolymer. The materials were characterized pre- and post-implantation by size-exclusion chromatography (SEC), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), and light-microscopy. Degradation seems to follow an autocatalytic hydrolysis mechanism. The amorphous copolymer was degraded at a faster rate and gave a less pronounced foreign body reaction as compared to the semicrystalline one.
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