Molecular regulation of hematopoiesis

The molecular nature of stem cell regulatory pathways has been determined using a variety of genetic approaches, including genetic loss-of-function and gain-of-function studies. These have provided several important concepts regarding the molecular control of hematopoiesis. First, some genes have binary functions and are either on or off in various biological states, while other genes function in a continuum and have different effects at different levels. Secondly, while perturbations in single...

Intestinal iron transport

Our current understanding of intestinal non-heme iron transport is illustrated in Figure 13.1. Iron absorption takes place in an acidic environment in the proximal small intestine, just distal to the gastric outlet. Most non-heme dietary iron is in the ferric (Fe3+) form. It is reduced to Fe2+ by a brush border ferrireductase, most likely the recently identified duo- Fig. 13.1 Current understanding of intestinal non-heme iron absorption The cartoon shows an absorptive enterocyte from the...

Immunopathogenesis of idiopathic aplastic anemia

The most direct evidence that IAA may be an autoimmune disorder has come from the clinical observation that patients Table 12.4 Classification of the bone marrow failure (BMF) syndromes. Table 12.4 Classification of the bone marrow failure (BMF) syndromes. Autosomal dominant Autosomal recessive Neutropenia, exocrine pancreatic insufficiency, metaphyseal dysostosis Absent megakaryocytes in bone marrow, late BMF Thrombocytopenia with absent radii syndrome Bilateral radial aplasia, lower limb...