| 1. |
- Blomqvist, G, et al.
(författare)
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Differences in lodgement of tumour cells in muscle and liver
- 1988
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Ingår i: Clinical and Experimental Metastasis. - 1573-7276. ; 6:4, s. 285-289
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Tidskriftsartikel (refereegranskat)abstract
- Differences in the lodgement of circulating tumour cells in various organs are considered an important factor in metastatic organ selection. The present vital microscopic studies show that the pattern of intravascular arrest of tumour cells in muscle after intra-arterial injection is similar to that observed earlier, in the liver, after intraportal injection. However, parallel isotope studies on the lodgement process (at 5 min and 3 h after injection) showed that the tumour cells trapped in the muscle microvasculature were destroyed at a higher rate than in the liver. Tumour cells kept in test tubes, and thus not being subjected to the shearing forces of the circulation, had a higher survival rate than cells trapped in the muscle. The results indicate that stronger retardation forces acting on the tumour cells in muscle (arterial dissemination) than in the liver (venous dissemination) may be one mechanism behind the increased tumour cell destruction in muscle.
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| 2. |
- Braide, M, et al.
(författare)
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Migration of human granulocytes in filters: effects of gravity and movable gradients of f-MLP
- 1994
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Ingår i: 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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Tidskriftsartikel (refereegranskat)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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| 3. |
- Braide, M, et al.
(författare)
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Optimized density gradient separation of leukocyte fractions from whole blood by adjustment of osmolarity
- 1986
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Ingår i: Journal of Immunological Methods. - : Elsevier BV. - 1872-7905 .- 0022-1759. ; 93:2, s. 183-191
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Tidskriftsartikel (refereegranskat)abstract
- Some of the compounds used for density gradient separation of blood cells have high osmolarities at the concentrations needed to create the required specific densities. Several mixed media use a combination of hyperosmolar shrinkage and red cell aggregation to improve cell separation. Due to the characteristics of Percoll density gradient medium the density and osmolarity of the gradient can be controlled separately. In the present study, Percoll gradients were used to determine the buoyant densities of different human blood cells at the osmolarities 300 mosM, 350 mosM and 400 mosM. Cell volumes were measured at the same osmolarities using a Coulter counter with channelyzer. As expected, the cell buoyant densities increased and the cell volumes decreased at the higher osmolarities used. There were, however, quantitative differences between the cells with respect to the effects of an increased osmolarity, making a 350 mosM density gradient the most effective in separating mononuclear leukocytes from polymorphonuclear leukocytes. A 400 mosM gradient offered the best possibilities to separate red blood cells from polymorphonuclear leukocytes. A one-step centrifugation procedure, based on these principles, is presented. This procedure makes possible the simultaneous purification of mononuclear leukocytes and polymorphonuclear leukocytes, suitable for functional assays.
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