scholarly journals CHANGES IN OUTLYING BONE MARROW ACCOMPANYING A LOCAL INCREASE OF TEMPERATURE WITHIN PHYSIOLOGICAL LIMITS

1936 ◽  
Vol 64 (2) ◽  
pp. 253-274 ◽  
Author(s):  
Charles Huggins ◽  
B. H. Blocksom
Keyword(s):  
Bone Marrow ◽  
Blood Cell ◽  
Common Factor ◽  
Cell Formation ◽  
Fat Distribution ◽  
Low Oxygen ◽  
Physiological Limits ◽  
Red Marrow ◽  
Normal Differentiation ◽  
Adult Bone

A great difference exists in the adult bone marrow of central bones as compared with outlying bones of the mammalia and avia, the distal bones being at a great disadvantage from the standpoint of blood cell production. Several experimental procedures are reported by which this disadvantage is overcome and in consequence fatty marrow of outlying bones is replaced by red marrow occurring chiefly at the epiphyseal regions, unless a low oxygen stimulus is also provided when marrow of the diaphysis becomes involved. A common factor in all of the experiments was an elevation of temperature beyond that prevailing in these distal regions, and it is felt that the evidence warrants the opinion that the cause of improvement is thermal. In some experiments, blood cell formation was increasing while the heat was adversely affecting the testis. The experiments permit construction of a general theory of fat distribution in bone marrow. In certain grafts of precartilage to other rats, normal differentiation into bone, cartilage, and marrow occurred, while in others cartilage and very small amounts of primitive marrow developed with slight, or no bone formation. Cartilage was always successfully engrafted. The capacity to form sinusoids in bone marrow is determined by the nature of the tissue rather than by the ingrowing endothelium.

Expression of connexin 43 (Cx43) is critical for normal hematopoiesis

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 917-924 ◽  
Author(s):  
Encarnacion Montecino-Rodriguez ◽  
Hyosuk Leathers ◽  
Kenneth Dorshkind
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
Blood Cell ◽  
Gap Junctions ◽  
Connexin 43 ◽  
Cell Formation ◽  
Cx43 Expression ◽  
Hematopoietic System ◽  
Blood Cell Formation

Abstract Gap junctions are intercellular channels, formed by individual structural units known as connexins (Cx), that allow the intercellular exchange of various messenger molecules. The finding that numbers of Cx43-type gap junctions in bone marrow are elevated during establishment and regeneration of the hematopoietic system has led to the hypothesis that expression of Cx43 is critical during the initiation of blood cell formation. To test this hypothesis, lymphoid and myeloid development were examined in mice with a targeted disruption of the gene encoding Cx43. Because Cx43−/− mice die perinatally, initial analyses were performed on Cx43−/−, Cx43+/−, and Cx43+/+ embryos and newborns. The data indicate that lack of Cx43 expression during embryogenesis compromises the terminal stages of primary T and B lymphopoiesis. Cx43−/− embryos and neonates had a reduced frequency of CD4+ and T-cell receptor-expressing thymocytes and surface IgM+cells compared to their Cx43+/+ littermates. Surprisingly, Cx43+/− embryos/neonates also showed defects in B- and T-cell development similar to those observed in Cx43−/− littermates, but their hematopoietic system was normal at 4 weeks of age. However, the regeneration of lymphoid and myeloid cells was severely impaired in the Cx43+/− mice after cytoablative treatment. Taken together, these data indicate that loss of a single Cx43 allele can affect blood cell formation. Finally, the results of reciprocal bone marrow transplants between Cx43+/+ and Cx43+/− mice and examination of hematopoietic progenitors and stromal cells in vitro indicates that the primary effects of Cx43 are mediated through its expression in the hematopoietic microenvironment.

scholarly journals BLOOD CELL FORMATION AND DISTRIBUTION IN RELATION TO THE MECHANISM OF THYROID-ACCELERATED METAMORPHOSIS IN THE LARVAL FROG

1923 ◽  
Vol 38 (5) ◽  
pp. 529-541 ◽  
Author(s):  
H. E. Jordan ◽  
C. C. Speidel
Keyword(s):  
Bone Marrow ◽  
Blood Cell ◽  
Metabolic Rate ◽  
Cell Formation ◽  
The Body ◽  
Red Bone Marrow ◽  
History Of ◽  
Regressive Change ◽  
Mesenchymal Precursor ◽  
Hemopoietic Organ

1. Thyroid-accelerated metamorphosis in the larval frog is accompanied by changes in the hemopoietic centers and in the blood cell distribution in the various regions of the body. These changes are interpreted as results of the fundamental change in basal metabolic rate induced by the thyroid treatment. 2. There is initiation of the shift of hemopoietic locus from the kidney, the larval hemopoietic organ, to the spleen, the adult hemopoietic organ. The spleen, being chiefly an erythrocyte producer, becomes of greater importance with the transition from the lower metabolic rate to the higher, since greater erythropoiesis becomes necessary to supply the physical basis for the maintenance of the higher metabolic rate. 3. It is suggested that the appearance of red bone marrow in the later history of the frog is correlated with a still higher metabolic rate. Phylogenetically, in the vertebrate series, red bone marrow is also associated with higher metabolic rate. 4. The new metabolic rate initiated in tadpoles by thyroid administration sets up a demand for (a) erythrocytes, (b) granulocytes and lymphoid phagocytes for distribution to regions of regressive change, (c) lymphocytes, (1) as progenitors of erythrocytes, granulocytes and phagocytes, (2) for promoting growth of cells in regions of progressive change. 5. Upon the hemopoietic reserve, which in the last analysis is the lymphocyte (and its mesenchymal precursor), depends the extent to which metamorphosis will proceed. Inability on the part of the hemopoietic centers, chiefly the spleen, to keep pace with the demand for blood cells during metamorphosis results in metamorphic stasis, a condition of anemia which is usually followed by death. 6. The growth-promoting function of leucocytes, as demonstrated by Carrel, is probably to be ascribed to the lymphocyte component of leucocytes. 7. The granulocytes have probably also a glandular function, and may exert a lytic effect upon adjacent tissues in regions of regressive change.

scholarly journals Hemogenic endothelium during development and beyond

Blood ◽  
2012 ◽  
Vol 119 (21) ◽  
pp. 4823-4827 ◽  
Author(s):  
Karen K. Hirschi
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Endothelial Cells ◽  
Blood Cell ◽  
Fetal Liver ◽  
Hemogenic Endothelium ◽  
Hematopoietic Stem ◽  
Adult Bone ◽  
Definitive Hematopoiesis ◽  
Yolk Sac Placenta

Abstract During embryonic development, multilineage HSCs/progenitor cells are derived from specialized endothelial cells, termed hemogenic endothelium, within the yolk sac, placenta, and aorta. Whether hemogenic endothelial cells contribute to blood cell development at other sites of definitive hematopoiesis, such as in the fetal liver and fetal bone marrow, is not known. Also unknown is whether such cells exist within the vasculature of adult bone marrow and generate hematopoietic stem cells after birth. These issues and their clinical relevance are discussed herein.

scholarly journals A distinct CD115- erythro-myeloid precursor present at the maternal-embryonic interface and in the bone marrow of adult mice

2021 ◽  
Author(s):  
Shweta Tikoo ◽  
Rohit Jain ◽  
Brendon Martinez ◽  
Renhua Song ◽  
Matthias Wielscher ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Blood Cell ◽  
Progenitor Cells ◽  
Alternative Pathway ◽  
Uterine Wall ◽  
Yolk Sac ◽  
Primary Site ◽  
Adult Mice ◽  
Adult Bone ◽  
Macrophage Precursors

During ontogeny, macrophages develop from CD115+ precursors, including erythro-myeloid progenitors (EMP). EMP arise in the embryonic yolk sac, the primary site of early haematopoiesis. In adults, CD115+ bone marrow-derived monocytes represent essential macrophage precursors. Herein, we identify a CD115- macrophage precursor within the adult bone marrow that is unrelated to the classical monocyte lineage but rather shares transcriptomic and functional characteristics of embryonic EMP. These EMPROR (for Erythro Myeloid Precursor) cells are capable of efficiently generating macrophages in disease settings. During early development, EMPROR cells were largely absent from the yolk sac but were instead found at the embryonic-maternal interface in the uterine wall. Unexpectedly, the latter site contains robust haematopoietic activity and harbours defined embryonic haematopoietic progenitor cells, including classical CD115+ EMP. Our data suggest the existence of an alternative pathway of macrophage generation in the adult. Further, we uncover a hitherto unknown site of earliest blood cell development.

Expression of connexin 43 (Cx43) is critical for normal hematopoiesis

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 917-924
Author(s):  
Encarnacion Montecino-Rodriguez ◽  
Hyosuk Leathers ◽  
Kenneth Dorshkind
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
Blood Cell ◽  
Gap Junctions ◽  
Connexin 43 ◽  
Cell Formation ◽  
Cx43 Expression ◽  
Hematopoietic System ◽  
Blood Cell Formation

Gap junctions are intercellular channels, formed by individual structural units known as connexins (Cx), that allow the intercellular exchange of various messenger molecules. The finding that numbers of Cx43-type gap junctions in bone marrow are elevated during establishment and regeneration of the hematopoietic system has led to the hypothesis that expression of Cx43 is critical during the initiation of blood cell formation. To test this hypothesis, lymphoid and myeloid development were examined in mice with a targeted disruption of the gene encoding Cx43. Because Cx43−/− mice die perinatally, initial analyses were performed on Cx43−/−, Cx43+/−, and Cx43+/+ embryos and newborns. The data indicate that lack of Cx43 expression during embryogenesis compromises the terminal stages of primary T and B lymphopoiesis. Cx43−/− embryos and neonates had a reduced frequency of CD4+ and T-cell receptor-expressing thymocytes and surface IgM+cells compared to their Cx43+/+ littermates. Surprisingly, Cx43+/− embryos/neonates also showed defects in B- and T-cell development similar to those observed in Cx43−/− littermates, but their hematopoietic system was normal at 4 weeks of age. However, the regeneration of lymphoid and myeloid cells was severely impaired in the Cx43+/− mice after cytoablative treatment. Taken together, these data indicate that loss of a single Cx43 allele can affect blood cell formation. Finally, the results of reciprocal bone marrow transplants between Cx43+/+ and Cx43+/− mice and examination of hematopoietic progenitors and stromal cells in vitro indicates that the primary effects of Cx43 are mediated through its expression in the hematopoietic microenvironment.

Development and study of a method for cell separation during white blood cell segmentation on images of bone marrow preparations in information and measurement systems for diagnostics of acute leukemia

2020 ◽  
pp. 68-72
Author(s):  
V.G. Nikitaev ◽  
A.N. Pronichev ◽  
V.V. Dmitrieva ◽  
E.V. Polyakov ◽  
A.D. Samsonova ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Blood Cell ◽  
Acute Leukemia ◽  
White Blood Cell ◽  
Cell Separation ◽  
Large Scale ◽  
Bone Marrow Cells ◽  
Automated Analysis ◽  
Cell Segmentation ◽  
Measurement Systems

The issues of using of information and measurement systems based on processing of digital images of microscopic preparations for solving large-scale tasks of automating the diagnosis of acute leukemia are considered. The high density of leukocyte cells in the preparation (hypercellularity) is a feature of microscopic images of bone marrow preparations. It causes the proximity of cells to eachother and their contact with the formation of conglomerates. Measuring of the characteristics of bone marrow cells in such conditions leads to unacceptable errors (more than 50%). The work is devoted to segmentation of contiguous cells in images of bone marrow preparations. A method of cell separation during white blood cell segmentation on images of bone marrow preparations under conditions of hypercellularity of the preparation has been developed. The peculiarity of the proposed method is the use of an approach to segmentation of cell images based on the watershed method with markers. Key stages of the method: the formation of initial markers and builds the lines of watershed, a threshold binarization, shading inside the outline. The parameters of the separation of contiguous cells are determined. The experiment confirmed the effectiveness of the proposed method. The relative segmentation error was 5 %. The use of the proposed method in information and measurement systems of computer microscopy for automated analysis of bone marrow preparations will help to improve the accuracy of diagnosis of acute leukemia.

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