Differential inhibition of polymorphonuclear leukocyte recruitment in vivo by dextran sulphate and fucoidan

The selectin-mediated rolling of leukocytes along the endothelial cells is a prerequisite step followed by firm adhesion and extravasation into the inflamed tissue. This initial contact can be suppressed by sulphated polysaccharides. We have studied the effect of sulphated polysaccharides on the ultimate polymorphonuclear leukocyte (PMN) recruitment and plasma leakage in rabbit skin in response to intradermal injection of various inflammatory mediators. PMN infiltration evoked by various PMN chemoattractants (FMLP, C5a desArg, LTB4 and IL-8) was significantly inhibited after intravenous injection of dextran sulphate (25 mg/kg), heparin (2 × 90 mg/kg) or fucoidan (1 mg/kg). PMN-dependent plasma leakage was equally well reduced by the different sulphated polymers. Vascular permeability induced by histamine or thrombin acting via a PMN-independent mechanism was not reduced. Fucoidan was the only polysaccharide able to suppress IL-1-induced PMN infiltration for 60–70%. Local administration of dextran sulphate had no effect on PMN-dependent plasma leakage. Differential inhibition of PMN recruitment was determined after injection of dextran sulphate or fucoidan depending on the type of insult. Therefore, these results suggest that different adhesion pathways are utilized during PMN recruitment in vivo in response to chemoattractants and IL-1

Thermal time models and predictions for germination of six provenances of Scots pine (Pinus sylvestris) in southern England

There has been little research on the benefits and risks associated with the use of seeds from more southerly seed sources. Temperature requirements and thermal time parameters were determined for six P. sylvestris provenances selected to represent a wide latitudinal range across the species. Distribution and thermal time parameters were used to predict field emergence under current and predicted future climatic conditions for southern England.There were significant differences among provenances in germination capacity. Southern provenances had a higher germination capacity, germinated earlier and more rapidly over a wider range of temperatures than northern provenances.Keywords: Provenance; climate change; seed source; thermal time model; dormanc

Dimensional Relations and Physical Properties of Wood of Acacia saligna, an Invasive Tree species growing in Botswana

Abstrac

Intradermal Anti-Loxosceles Fab Fragments Attenuate Dermonecrotic Arachnidism

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73371/1/j.1553-2712.1999.tb00133.x.pd

Chemokines in rheumatoid arthritis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46938/1/281_2004_Article_BF00832002.pd

Schipperen tussen NT２, NVT en NT１

Kroniek van het Nederlands als vreemde taa