We tested the hypothesis that the accumulation of bound autologous antibody on a "senescent epitope" identifies aged erythrocytes for phagocytic removal by macrophages. Erythrocytes were collected from mice maintained on a hypertransfusion protocol designed to yield cells of defined age. The mouse erythrocytes were assayed for the presence of bound antibody by measuring their susceptibility to ...

CMAJ • NOVEMBER 23, 2010 • 182(17) © 2010 Canadian Medical Association or its licensors E798 A22-year-old nulliparous woman in her 32nd week of pregnancy was referred to our emergency department because she had been unable to walk for three days. Three weeks before admission, she had felt a burning sensation in her lower thoracic region, which she attributed to the pregnancy. However, she had i...

The ploidy distribution of megakaryocytes shifts in response to platelet demand and thus provides a sensitive index of megakaryocytopoiesis. Flow cytometry (FCM) is a potentially valuable method for rapid determination of ploidy distributions of megakaryocyte populations; however, because megakaryocytes constitute only a very small proportion of the cells in unfractionated marrow, other rare ev...

In order to characterize the defect in erythroid homeostasis in chronic inflammatory states, the relationship between erythropoietin production and erythropoietic response was examined in rats with adjuvant disease. Exposure of adjuvant-injected rats to graded levels of lowered barometric pressure induced increases in plasma erythropoietin which were significantly less than those measured in no...

The rheologic properties of senescent erythrocytes have been examined using two models of red blood cell (RBC) aging. In the rabbit, aged erythrocytes were isolated after biotinylation, in vivo aging, and subsequent recovery on an avidin support. Aged RBCs from the mouse were obtained using the Ganzoni hypertransfusion model that suppresses erythropoiesis for prolonged periods of time allowing ...

The role of the kidney in foetal erythropoiesis was studied in newborn SD mice on the day of birth. Some of the homozygotes and heterozygotes of this strain are born anephric. Red cell production was evaluated by haematocrit levels, reticulocyte counts, and Fe-uptake in liver and RBC, the isotope given to the mothers during pregnancy. Erythropoiesis of the newborn with renal agenesis was not di...

E RYTHROPOIETIN is believed to be the prime physiologic regulator of erythropoiesis.1 It is generally assumed that erythropoietin production is chiefly controlled by the demands of tissues for oxygen relative to their oxygen supply.1 According to this hypothesis transfusion-induced polycythemia results in suppression of erythropoietin production ( and consequently of erythropoiesis ) by virtue ...

The immunohistochemical distribution of Forssman glycosphingolipid (GSL) in mouse hematopoietic tissue was examined by using light and electron microscopic immunoperoxidase methods with a highly specific rabbit anti-Forssman GSL antibody. Bone marrow, splenic red pulp, and thymic macrophages, which are closely associated with hematopoietic cells, were stained by the antibody, whereas hematopoie...