Altered immune reconstitution of B and T cells precedes the onset of clinical symptoms of chronic graft-versus-host disease and is influenced by the type of onset.

We analyzed lymphocyte subpopulations and cytokines 3 months after allogeneic hematopoietic stem cell transplantation aiming to identify predictive cellular and serum markers for chronic graft-versus-host disease (cGVHD). Samples of 49 patients (pts) (no cGVHD (n = 14), subsequent quiescent onset (n = 16), de novo onset of cGVHD (n = 19)) were analyzed in the absence of active GVHD by flow cytometry and enzyme-linked immunosorbent assay. All mean absolute cell counts are presented as cells per microliter; relative cell counts are presented as percentage of lymphocytes. Pts with subsequent de novo cGVHD had significantly higher relative and absolute counts of CD4+ T cells including higher absolute counts of CD4+ memory T cells (22.36%; 206.55/µl; 136/µl, respectively) compared to pts with subsequent quiescent onset of cGVHD (12.41%; 83.42/µl; 54.3/µl) and pts without cGVHD (10.55%) with regard to relative counts of CD4+ T cells. Similarly, significantly more relative and absolute regulatory T cell numbers (CD4+FOXP3+) were detected in pts with de novo onset of cGVHD (3.08% and 24.63/µl) compared to those in pts without (1.25% and 9.06/µl) or with quiescent onset of cGVHD (1.15% and 6.91/µl). Finally, relative B cell counts, including naïve and memory B cells, were also significantly decreased in pts developing quiescent cGVHD (0.85, 0.73, 0.12% resp.) when compared to pts with de novo onset (5.61, 5.24, 0.38%). The results demonstrate that alterations in immune reconstitution are already present before onset of clinical symptoms and differ between de novo and quiescent onset of disease.

Dating of pore waters with (129)I: relevance for the origin of marine gas hydrates

Pore waters associated with gas hydrates at Blake Ridge in the Atlantic Ocean were dated by measuring their iodine-129/iodine ratios. Samples collected from sediments with ages between 1.8 and 6 million years ago consistently yield ages around 55 million years ago. These ages, together with the strong iodine enrichment observed in the pore waters, suggest that the origin of iodine is related to organic material of early Tertiary age, which probably is also the source of the methane in the gas hydrates at this location.

Confusion of laterally inverted mirror-images: a relationship to brain anatomy?

Whereas in the monkey brain the representation of spatial direction (left/ right) is the same for visual and for tactual inflow, in the human brain visual and tactual lateral directions are not aligned with respect to one another. This anatomical feature of the human brain may account in part for the particular difficulty young sighted children have with laterally inverted forms. A small group of children who were totally blind since birth distinguished mirror pairs by touch significantly more easily than did sighted children of comparable age; and monkeys succeeded at cross-modal recognition of laterally inverted mirror pairs better (relative to control pairs) than did sighted children.