Browsing by Subject "Lymphatics"

Now showing 1 - 2 of 2
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    Organ specificity of the structural organization and fine distribution of lymphatic capillary networks: Histochemical study
    (Murcia : F. Hernández, 2000) Kato, S.
    Histochemical studies of the microcirculatory system were reviewed with regard to the organ specificity of the structural organization and fine distribution of the lymphatic capillary network. The lymphatics and blood vessels are characterized by an enzyme-histochemical method using 5'-nucleotidase (5'- Nase), alkaline phosphatase (ALPase) andlor diaminopeptidase (DAPase) staining in additon to an immunohistochemical method. The 5'-Nase-positive lymphatic vessels can be distinguished histochemically from arterial and venous vessels based on ALPase and DAPase activity, respectively. The specificity and localization of the enzyme reactions were confirmed by comparative histochemical studies of the same specimen with light microscopy and scanning or transmission electron microscopy. These histochemical methods are discussed in relation to their ability to demonstrate the organ specificity of vascular networks under normal and pathological conditions.
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    Specification of arterial, venous, and lymphatic endothelial cells during embryonic development
    (Murcia : F. Hernández, 2010) Kume, Tsutomu
    The groundbreaking discovery about arterial and venous expression of ephrinB2 and EphB4, respectively, in early embryonic development has led to a new paradigm for vascular research, providing compelling evidence that arterial and venous endothelial cells are established by genetic mechanisms before circulation begins. For arterial specification, vascular endothelial growth factor (VEGF) induces expression of Notch signaling genes, including Notch1 and its ligand, Delta-like 4 (Dll4), and Foxc1 and Foxc2 transcription factors directly regulate Dll4 expression. Upon activation of Notch signaling, the Notch downstream genes, Hey1/2 in mice or gridlock in zebrafish, further promote arterial differentiation. On the other hand, the orphan nuclear receptor COUP-TFII is a determinant factor for venous specification by inhibiting expression of arterial specific genes, including Nrp1 and Notch. After arterial and venous endothelial cells differentiate, a subpopulation of venous endothelial cells is thought to become competent to acquire lymphatic endothelial cell fate by progressively expressing the transcription factors Sox18 and Prox1 to differentiate into lymphatic endothelial cells. Therefore, it has now evident that arterial-venous cell fate determination and subsequent lymphatic development are regulated by the multi-step regulatory system associated with the key signaling pathways and transcription factors. Furthermore, new signaling molecules as additional regulators in these processes have recently been identified. As the mechanistic basis for a link between signaling pathways and transcriptional networks in arterial, venous and lymphatic endothelial cells begins to be uncovered, it is now time to summarize the literature on this exciting topic and provide perspectives for future research in the field.