| 1. |
- Jones, Dylan T, et al.
(författare)
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Albumin activates the AKT signaling pathway and protects B-chronic lymphocytic leukemia cells from chlorambucil- and radiation-induced apoptosis.
- 2003
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 101:8, s. 3174-80
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Tidskriftsartikel (refereegranskat)abstract
- Activation of the phosphatidylinositol 3- kinase/AKT pathway antagonizes apoptosis in diverse cellular systems. We previously showed that human plasma activated AKT and potently blocked the ability of chlorambucil or gamma radiation to induce apoptosis of B-chronic lymphocytic leukemia (CLL) cells. Here we report experiments that identify albumin as the major component of plasma that blocks CLL cell killing by chlorambucil or radiation. Intact plasma depleted of albumin by chromatography on Cibacron blue-Sepharose or plasma from a subject with analbuminemia failed either to activate AKT or to protect CLL cells from chlorambucil-induced apoptosis. Both functions were restored by re-addition of albumin. The protective action of albumin as well as AKT activation was compromised by the binding of lipids. Fluorescence-activated cell sorter (FACScan) analysis demonstrated the uptake of fluoresceinated albumin by CLL cells. Accumulation of albumin in intracellular vesicles was also shown by confocal microscopy. Indirect inhibition of AKT activation by the phosphatidylinositol 3-kinase inhibitor LY294002 reversed the blockade of chlorambucil-induced killing by plasma albumin. The data suggest that activation of AKT consequent to binding of albumin by CLL cells blocks chlorambucil- and radiation-induced apoptosis. Strategies designed to block albumin-induced antiapoptotic signaling may, therefore, be of value in enhancing cytotoxic drug action on CLL cells.
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| 2. |
- Engelhard, D, et al.
(författare)
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Early and late invasive pneumococcal infection following stem cell transplantation: a European Bone Marrow Transplantation survey
- 2002
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048. ; 117:2, s. 444-450
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Tidskriftsartikel (refereegranskat)abstract
- Streptococcus pneumoniae (S. pneumoniae) may cause severe and lethal infections months and years following stem cell transplantation (SCT). In a prospective survey over a 3.5-year period, we assessed the incidence, risk factors and outcome for invasive pneumococcal infection (IPI) following SCT. Fifty-one episodes of IPI were reported: 43 episodes after bone marrow transplantation (BMT) and 8 after peripheral blood stem cell transplantation (PBSCT); 35 after allogeneic SCT and 16 after autologous SCT. Seven IPI episodes, all bacteraemias, were defined as early, occurring 1-35 d (median 3 d) post transplantation. Forty-four episodes were defined as late (greater than or equal to 100 d post SCT), occurring 4 months to 10 years (median 17 months) post transplantation. The incidences of early and late IPI were 2.03/1000 and 8.63/1000 transplantations respectively (P = 0.001). A higher incidence of late IPI was observed after BMT than after PBSCT (10.99 versus 3.23/1000; P < 0.01) and after allogeneic versus autologous SCT (12.20 versus 4.60/1000; P < 0.01). There was a higher estimated incidence of IPI in allogeneic patients with than in those without graft-versus-host disease (GVHD) (18.85 versus 8.25/1000; P = 0.015). The mortality rate was 20%, including 2/7 of early and 8/44 of late IPI. S. pneumoniae is a rare but important complication during the aplastic phase after SCT. In conclusion, S. pneumoniae is a significant cause of morbidity late post-transplantation, especially in allogeneic patients, and particularly those with GVHD. The high IPI mortality rate, both early and late post-transplantation, requires preventive approaches, mainly effective immunization.
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| 3. |
- Lucht, W, et al.
(författare)
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Climatic control of the high-latitude vegetation greening trend and Pinatubo effect
- 2002
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 296:5573, s. 1687-1689
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Tidskriftsartikel (refereegranskat)abstract
- A biogeochemical model of vegetation using observed climate data predicts the high northern latitude greening trend over the past two decades observed by satellites and a marked setback in this trend after the Mount Pinatubo, volcano eruption in 1991. The observed trend toward earlier spring budburst and increased maximum leaf area is produced by the model as a consequence of biogeochemical vegetation responses mainly to changes in temperature. The post-Pinatubo decline in vegetation in 1992-1993 is apparent as the effect of temporary cooling caused by the eruption. High-latitude CO2 uptake during these years is predicted as a consequence of the differential response of heterotrophic respiration and net primary production.
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