PubMed · 14046423
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
E M GREISHEIMER. 1963. PROGRESS IN PHYSIOLOGY.. https://pubmed.ncbi.nlm.nih.gov/14046423/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Blood products should be irradiated during allogeneic stem cell transplantation and before performing autologous stem cell harvest for prevention of acute transfusion-associated graft-versus-host disease (TA-GVHD). Usually, irradiation of all blood products is continued lifelong in the allogeneic setting. Up to now, no broadly accepted rules exist concerning autologous stem cell transplantation. We present here the results of an inquiry sent to 47 German transplantation centers regarding the transfusion policy following autologous stem cell transplantation. The results of 35 answering centers are included. Ten out of 35 centers offer irradiated blood products lifelong to their patients, mainly for the prevention of mistransfusion of non-irradiated blood components to allogeneic recipients. Twenty-two out of 35 centers administer irradiated blood products for a special time span after autologous stem cell transplantation. In most centers, this time span is from 3 to 6 months. Only few centers (4/35) expand this time span to 1-2 years after transplantation. A minority of centers (3/35) gave non-irradiated blood products to all of their patients or to patients not suffering from acute leukemia or after total body irradiation (TBI) containing preparative regimens. Most centers (19/35) deliver irradiated blood products irrespective of the conditioning regimen. Fifty-three percent of the centers decide to donate irradiated blood products not depending on immunological reconstitution. But in most centers some kind of hematological reconstitution is a major criterion for termination of irradiated blood products. Sixty-four percent of the centers made no difference in transfusion policy in regard to the underlying disease. No center experienced cases of proofed TA-GVHD. Guidelines should be worked out concerning transfusion policy after autologous stem cell transplantation.
C3b2-IgG complexes are formed during complement activation in serum by attachment of two C3b molecules (the proteolytically activated form of C3) to one IgG heavy chain (IgG HC) via ester bonds. Because of the presence of two C3b molecules, these complexes are very efficient activators of the alternative complement pathway. Likewise, dimeric C3b is known to enhance complement receptor 1-dependent phagocytosis, and dimeric C3d (the smallest thioester-containing fragment of C3) linked to a protein antigen facilitates CR2-dependent B-cell proliferation. Because the efficiency of all these interactions depends on the number of C3 fragments, we investigated whether C3b2-IgG complexes retained dimeric structure upon physiological inactivation. We used two-dimensional SDS-PAGE and Western blot to study the arrangement of the C3b molecules by analyzing the fragmentation pattern after cleavage of the ester bonds. Upon inactivation with factors H and I, a 185-kDa band was generated under reducing conditions. It released IgG HC and the 65-kDa fragment of C3b alpha' chain after hydrolysis of the ester bonds with hydroxylamine. The two C3b molecules were not 65-kDa-to-40-kDa linked, because neither ester-bonded 65 kDa HC nor 65 kDa-40 kDa fragments were observed, nor was a 40-kDa peptide released after hydroxylamine cleavage. Factor I and CR1 cleaved the C3b2-IgG molecule to its final physiological product, C3dg2-IgG, which migrated as a 133-kDa fragment in reduced form. This fragment released exclusively C3dg (the final physiological product of C3b inactivation by factor I) and IgG HC. C3dg2-HC appeared as a double band on SDS-PAGE only at low gel porosity, suggesting the presence of two conformers of the same composition. Our results suggest that, upon physiological inactivation, C3b2-IgG complexes retain dimeric inactivated C3b and C3dg, which allows bivalent binding to the corresponding complement receptors.
Explore the source record for details and available documents.