Biomedical subjects
Publications and source records attributed to B Norberg.
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The incidence of oxalate-induced radial-segmented (RS) nuclei in lymphocytes from peripheral blood correlated closely with the diameter of the cell and with the diameter of the nucleus; the majority of RS nuclei were found in large lymphocytes. This observation supports the basic hypotheses, that large lymphocytes from peripheral blood represent a later stage in the cell cycle than small lymphocytes, that the tubulin content of lymphocytes increases during the interphase and that the incidence of RS nuclei reflects the tubulin content of the cells within the various size classes.
The direction of lymphocytes with amoeboid movement configuration (AMC) was evaluated by means of electron microscopy of ultrathin sections of post-capillary high-endothelium venules (HE-venules) from rat lymph nodes. Out of 104 lymphocytes, 68 lymphocytes appeared to be on their way towards the lumen of the HE-venule and 36 lymphocytes appeared to be moving away from the venular lumen at the moment of fixation. This difference, which was statistically significant (p=0.0024), is thought to reflect the relative size of the migration stream of lymphocytes at the moment of fixation.
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The locomotive behaviour of human lymphocytes in coverslip preparations of clotted autoplasma was studied at +37 degrees C. Lymphocytes isolated from peripheral blood or from the tonsils did not move prior to membrane activation by means of incubation with phytohemagglutinin (PHA). After PHA stimulation the locomotion of 19 lymphocytes was analysed by time-lapse fliming. The locomotion was random, as evidenced by a median locomotive index of 0.64 (Q1-Q3 0.04-0.75) and comparatively slow, median velocity 15 mum/min (Q1-Q3 12-18). The locomotion of 5 other lymphocytes was studied at high magnification. It is suggested that the characteristic polarity of wandering lymphocytes, indicating the direction of movement, can be utilized in the analysis of the lymphocyte traffic in tissue sections of post-capillary high-endothelium venules.
Thin sections of lymph nodes from 14 rats were examined by phase contrast microscopy as regards direction of lymphoctes with amoeboid movement configuration (AMC) relative to the basement membrane of post-capillary high-endothelium venules (HE-cenules). Out of 118 lymphocytes with AMC, 82 appeared to be on theyr way into the venule from the lymph node parenchyma. This observation suggests that the lymphocyte traffic over the HE-venules is bi-directional, with the main migratory stream of lymphocytes from the lymph node parenchyma into the post-capillary venules.
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Bone marrow cells with spontaneous radial segmentation of the nuclei from three patients with acute myeloid leukaemia were analysed by means of electron microscopy. The centriole was found in the centre of the cluster of nuclear segments. Cytoplasmic microtubules were found in the intersegmental clefts and in the pericentriolar area. The present observations support the hypothesis that spontaneous radial segmentation of the nuclei in tumour cells is due to a microtubule-associated contractile process, by which the nucleus is folded into segments.
Griseofulvin inhibited the chemotaxis of polymorphonuclear leucocytes (PMN's) in vitro in the concentration range 0.1-1.0 mug/ml, i.e. at concentrations comparable to those obtained in serum during peroral treatment with griseofulvin. It is suggested that PMN chemotaxis is inhibited by griseofulvin interference with the redistribution of cytoplasmic microtubules, which is thought to be essential in the direction-finding of PMNs during chemotaxis. Furthermore, it is suggested that the griseofulvin inhibition of PMN chemotaxis - together with the previously known pharmacodynamic properties of griseofulvin - may provide the rationale for griseofulvin therapy in PMN-mediated tissue injury of the gut.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.