Main description:

In 1868, Ernst Neumann recognized that blood cells re quire continuous replenishment during postnata1life. Before him, the assumption was that cells of the blood, like nerves once formed in the embryo, remain in the body throughout life. Neumann also recognized that this process occurred within the bone marrow, because this tissue provided a fa vorable environment for proliferation and differentiation of blood cell precursors. Vera Danchakoff, the Russian embryologist working in the US, in 1916 made an analogy to the soil and the seed. Bone marrow forms the soil, providing a favorable environment for the growth of seed, the hemopoietic stem cell, and other progenitor cells. Imagine in the remote past a heap of similar tree seeds. These seeds develop in our moderate climate into a tall and many branched tree. Suppose the wind bears a part of the seeds away and brings them to a land possessing different environmental conditions, we will say the arc tic lands. There the seeds may develop but they may pro duce trees no higher than our moss.

Contents:

Hemopoietic Microenvironments Historical Perspectives, Status, and Projections.- Historical Perspectives, Status, and Projections.- Definition.- Radiation Protection by Marrow Transplantation.- The Spleen Colony Assay.- Antecedents of the Hemopoietic Microenvironment Concept.- Homing.- Unexplained Failure of Marrow Isografts.- Spleen Colony Types.- Decision.- Spleen Colony Retransplantation.- Effect of Erythropoietin Deprivation on Spleen Colony Types.- Visualization of Erythropoietin-Sensitive Stem Cell Colonies.- Decision for Lineage-Specific Differentiation.- Endoclonal Origin of the Second Line of Differentiation.- The Working Hypothesis.- Tests of the Working Hypothesis.- Bone Marrow Colonies and Characteristics.- Hemopoietic Colony Characteristics in Transplanted Spleen or Bone Marrow Stroma.- Whole Spleen Stroma Transplant 'Cure' of Sl/Sld Anemia.- Effect of Mouse Hemopoietic Microenvironments on Rat CFU-S.- Microenvironmental Control of Eosinophilic Granulocyte Response to Tetanus Toxoid.- Microenvironmental Control of Mast Cell Differentiation.- Dissecting the Hemopoietic Microenvironment.- Other Evidence of the Roles of Marrow, Spleen, and Thymus Organ Stroma in Hemopoiesis and Lymphopoiesis.- Hemopoiesis on Intraperitoneal Cellulose Acetate Membranes.- CFU-S Heterogeneity.- Reversible Effect of Marrow and Spleen Microenvironments on Thymic Progenitor Cell Differentiation and Proliferation.- Reversible Predisposition of CFU-S for Direction of Differentiation.- Hemopoietic Hormone (Growth Factor) Receptors.- Pluripotency of Hemopoietic CFU-S for Lymphoid Differentiation.- Lymphoid-Inductive Microenvironments.- In Vitro Bone Marrow Cultures.- Early Methods.- The Dexter Method.- The Greenberger Modification.- B-Lymphocyte Cultures.- Distinctive Stromal Cells of Erythroid and Granuloid Spleen Colonies.- Erythroid Colonies.- Granuloid Colonies.- Other Candidate for In Vivo Hemopoietic Microenvironment Stromal Cells.- Hemopoiesis.- Random or Controlled?.- Projections.- Malignancy-Inducing Microenvironments?.- References.- Molecular and Cellular Traffic Across the Marrow Sinuses.- Marrow Structure.- Arterial and Venous Circulation.- Marrow Sinuses.- Marrow Nerves.- Evidence for Discrimination in the Release of Marrow Cells.- Factors Governing Release of Hemopoietic Cells.- Biophysical Properties of Developing Hemopoietic Cells.- Cell Releasing Factors.- Control of Blood Flow in Marrow.- The Anatomical Process of Release.- Ultrastructural Features of Reticulocyte Egress.- Modeling Reticulocyte Egress.- Ultrastructural Features of White Cell Egress.- Ultrastructural Features of Platelet Release.- Release of Immature Cells in Healthy Subjects.- Release of Immature Cells in Pathological States.- Release from and Reentry into Marrow of Stem Cells and Progenitor Cells.- References.- In Vivo Microscopy of Hemopoietic Tissue.- In Vivo Microscopic Methods.- Basic Methods.- Transillumination Methods.- Epi-illumination Methods.- In Vivo Microscopic Studies of Hemopoietic Tissue.- References.- Fatty Involution of Marrow and the Role of Adipose Tissue in Hemopoiesis.- Distribution of Red and Yellow Marrow.- The Role of Bone.- Ectopic Implantation of Bone Marrow.- Marrow Adipocyte.- Development.- Structure.- Function.- Distinct from Extramedullary Adipocytes.- Functional Differences.- Heterogeneity of Marrow Adipocytes.- Marrow Adipocytes in Culture.- Conclusions.- References.- Hematopoiesis on Artificial Membranes.- Hematopoiesis on Flat CEM.- Hematopoiesis On Stromally-Enriched, IP-Implanted Tubular CEM.- Hematopoiesis and Proteoglycans.- Role of Bone and Tooth Matrix Proteins in Hematopoiesis.- Irradiation of Stromal Cells.- Studies of Scraped, Devitalized, and Reimplanted CEM.- Overall Perspective and Significance of Hematopoiesis on CEM.- References.- Cellular Components of Stroma In Vivo in Comparison with In Vitro Systems.- Cellular Components of the Stroma.- Reticular Cells In Vivo.- Fibroblastic Reticular Cells in Long-Term Cell Culture.- Macrophages.- Macrophages of Bone Marrow Origin in Long-Term Culture.- References.- Stromal Cells in Long-Term Bone Marrow Cultures.- Cell Types in Adherent Layer.- Growth Factor Production by Adherent Cells.- Studies in Other Species Including Human.- Lymphoid Growth and Long-Term Culture.- TC-1 Cell Line.- Hypothesis.- References.- Cultured Stromal Cell Lines from Hemopoietic Tissues.- The Hemopoietic Microenvironment.- Putative Functions.- Nature of Stromal Cells.- Primary Cultures of Bone Marrow Stromal Cells.- The Requirement for Permanent Stromal Cell Lines.- Hemopoietic Stromal Cell Lines.- Derivation.- Growth.- Morphology.- Adipogenesis.- Cytoplasmic Enzymes.- Extracellular Matrix.- Cell Surface Markers.- Classification.- Long-Term In Vitro Hemopoiesis.- Colony Stimulating Factors (CSF).- Differentiation-Restraining Activities.- Other Regulators of Hemopoiesis.- Leukemia Cell Inhibitory Activity (LCIA).- Promotion of Leukemia Cell Growth.- Promoters of Leukemia Cell Differentiation.- Transplantation and Tumorigenesis.- Modulation of In Vitro Functions.- Tissue and Cell-Lineage Specificity.- Summary.- References.- Cellular Interactions in the Regulation of Human Hemopoiesis In Vitro.- Normal Hemopoiesis.- Role of T-Cells.- Role of Monocytes.- Role of NK Cells.- Abnormal Hemopoiesis.- Aplastic Anemia.- References.- The Collagenous Hemopoietic Microenvironment.- The Genetically-Distinct Types of Collagen.- Type I Collagen.- Type II Collagen.- Type III Collagen.- Type IV Collagen.- Type V Collagen.- Type VI Collagen.- Type VII Collagen.- Type VIII Collagen.- Type IX Collagen.- Type X Collagen.- Type XI Collagen.- Collagenous Bone Marrow Stroma.- Synthesis of Collagenous Matrix by Stromal Cells of the Bone Marrow.- Bone Marrow Collagen in Hematologic Disorders.- Myelofibrosis.- Future Prospects.- References.- The Hemopoietic Extracellular Matrix.- The Role of the Extracellular Matrix in Regulating Cell Growth and Differentiation.- Characterization of Noncollagenous Extracellular Matrix Macromolecules Found in Bone and Bone Marrow.- Fibronectin.- Laminin.- Proteoglycans.- Other Extracellular Matrix Proteins of Bone and Bone Marrow.- Summary of Extracellular Matrix Macromolecules Found in Bone and Bone Marrow.- Identification of Extracellular Matrix Proteins in the Stroma of Long-Term Bone Marrow Cell Cultures.- Fibronectin and Laminin.- Proteoglycans.- Summary of Extracellular Matrix Glycoproteins and Proteoglycans Produced in Long-Term Bone Marrow Cultures.- The Role of Extracellular Matrix Components in Regulating Hemopoiesis in Long-Term Bone Marrow Cultures.- Reconstitution of Bone and Bone Marrow In Vivo by Ectopic Implantation of Devitalized, DemineralizedBone Matrix.- Studies of the Abnormal Hemopoietic Microenvironment of Sl/Sld Mice.- Summary.- References.- Bone Marrow Microenvironment Clinical Observations.- Clinical Implications.- Functional Abnormalities of Cellular Components of Bone Marrow Microenvironment.- T-Lymphocytes.- Bone Marrow Macrophages.- Bone Marrow Fibroblasts.- References.