No abstract

The xylem surface of seedlings, stem material and roots of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) were inoculated with strains of Heterobasidion annosum s. str. and H. parviporum s. str. The depth of necrosis in wounded spruce increased at a linear rate for at least seven weeks of incubation, but the rate of necrotic spread was significantly faster in infected wounds. In wounded pine the necrosis was maintained at a more superficial level for several weeks. Both spruce and pine sapwood were initially infected by hyphae of both species. In spruce, the hyphae advanced at a constant rate behind the necrotic front. On the contrary, after 1-2 weeks living H. parviporum hyphae were rare in pine rays. Heterobasidion annosum hyphae survived in pine rays, phloem and tracheids, despite a heavy accumulation of phenolics and resins and were able to penetrate into the sapwood at a linear rate although slower than infections in spruce. Histochemistry and quantitative estimates demonstrated that peroxidase activity was initially higher in spruce sapwood than in pine. Within three days of incubation, the activity in spruce sapwood disappeared concurrently with deepening necrosis. However, in pine, in both control and infected samples, there was a significant increase in peroxidase activity in the area surrounding the superficial necrosis, up to the wound surface and in the cambium and phloem around the wound. After wounding and infection, the content of soluble protein increased significantly in wood of older trees but not in seedlings. Infection resulted in an increased formation of lipophilic extractives in both spruce and pine but to a significantly greater degree in the latter, whereas the amount of hydrophilic compounds decreased in both. High-performance liquid chromatography (HPLC) analyses of lipophilic extracts showed that inoculation of pine with the two species of Heterobasidion increased the amounts of pinosylvin, its monomethylether and several other phenolics as also resinous compounds. The results obtained may be relevant in explaining the known higher resistance of Scots pine to H. parviporum.

Complement-dependent cytotoxicity or flow cytometric lymphocyte crossmatch (LXM) tests may fail to detect clinically significant antibodies (Abs) against non-human leukocyte antigen (HLA). A flow cytometric endothelial precursor cell crossmatch (EPCXM) test (XM-ONE) is available for detection of Abs against donor endothelial precursor cells (EPCs). We showed that lymphocytes co-purified with EPCs can be used in LXM tests allowing simultaneous detection of Abs reactive with donor EPCs and lymphocytes. The lymphocyte population co-purified with EPCs on anti-Tie-2 Ab-coupled magnetic beads contained CD 8(+) and CD 4(+) T-cells, B-cells, and natural killer (NK)- and natural killer T (NKT)-cells. HLA class I antigen expression was slightly higher on CD 3(+) lymphocytes co-purified on Tie-2 Ab beads than on unseparated lymphocytes, whereas HLA class I and II antigen levels on CD 19(+) lymphocytes were not significantly different. Sera from 10 patients with panel-reactive Abs were tested on cells from nine donors using flow cytometric LXM and EPCXM tests. There was a very good correlation (R(2) = 0.94) between the channel shift values obtained on unseparated and Tie-2 Ab bead-isolated T-lymphocytes, whereas the correlation between the channel shift values obtained on the two B-lymphocyte populations was lower (R(2) = 0.71). T- and B-lymphocytes co-purified with EPCs can be used in LXM tests enabling simultaneous detection of donor lymphocyte- and EPC-reactive Abs in a single-tube XM-ONE assay.

An ELISA with structurally defined ABH antigens will allow the antibody class and fine specificity of ABO antibodies to be determined, which may improve risk assessment in ABO-incompatible transplantation.