DOCSLIB.ORG

Vascular Embryology and Angiogenesis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Vascular Embryology and Angiogenesis PART I Biology of Blood Vessels 1 Vascular Embryology and Angiogenesis Aglaia Ntokou, Inamul Kabir, Fatima Zahra Saddouk, and Daniel M. Greif In simple terms, the cardiovascular system consists of a sophisticated Finally, the outermost layer of the vessel wall is the adventitia, a collec- pump (i.e., the heart) and a remarkable array of tubes (i.e., the blood tion of loose connective tissue, fibroblasts, macrophages, cells express- and lymphatic vessels). Arteries and arterioles (the efferent blood ing stem-cell markers, and small vessels, known as the vasa vasorum, vessels in relation to the heart) deliver oxygen, nutrients, paracrine that perfuse the cells of larger arteries. hormones, blood and immune cells, and many other products to the This chapter summarizes many of the key molecular and cellular capillaries, small-caliber, thin-walled vascular tubes. These substances processes and underlying signals in the morphogenesis of the different are then transported through the capillary wall into the extravascu- layers of the blood vessel wall and of the circulatory system in general. lar tissues, where they participate in critical physiological processes. Specifically, for intimal development, it concentrates on early EC pat- In turn, waste products are transported from the extravascular space terning, specification and differentiation, lumen formation, branching, back into the blood capillaries and returned by the venules and veins metabolism, and lymphatic vessel morphogenesis. In the second sec- (the afferent vessels) to the heart. Alternatively, approximately 10% of tion, the development of the tunica media is divided into subsections the fluid returned to the heart courses via the lymphatic system to the examining the components of the media, VSMC origins, smooth mus- large veins. To develop normally, the embryo requires the delivery of cle cell (SMC) differentiation, and patterning of the developing VSMC nutrients and removal of waste products beginning early in develop- layers and the ECM. Finally, the chapter concludes with a succinct ment, and, indeed, the cardiovascular system functions early during summary of morphogenesis of the adventitia, adventitial stem cells, morphogenesis. and macrophages. Understanding these fundamental vascular devel- The fields of vascular embryology and angiogenesis have been opmental processes is important from a pathophysiological and ther- revolutionized through experimentation with model organisms. In apeutic standpoint because many diseases almost certainly involve the particular, this chapter focuses on key studies using common vas- recapitulation of developmental programs. For instance, in many vas- cular developmental models, including the mouse, zebrafish, chick, cular disorders, mature VSMCs dedifferentiate and exhibit increased and chick-quail transplants, each of which has its advantages. Among rates of proliferation, migration, and ECM synthesis through a process mammals, the most powerful genetic-engineering tools and the great- termed phenotypic switching.1 est breadth of mutants are readily available in the mouse. Furthermore, the mouse is a good model of many aspects of human vascular de- TUNICA INTIMA: ENDOTHELIUM velopment, and, in particular, the vasculature of the mouse retina is a powerful model as it develops postnatally and is visible externally. The Early Development zebrafish is a transparent organism that develops rapidly with a well- Development begins with the fertilization of the ovum by the sperm. described pattern of cardiovascular morphogenesis and sophisticated Chromosomes of the ovum and sperm fuse, and then a mitotic pe- genetic manipulations that are readily available. The chick egg is large riod ensues. The early 16- to 32-cell embryo, or morula, consists of with a yolk sac vasculature that is easily visualized and develops rapidly. a sphere of cells with an inner core termed the inner cell mass. The And finally, the coupling of chick-quail transplants with species-specific first segregation of the inner cell mass generates the hypoblast and antibodies allows for cell tracing experiments. The combination of stud- epiblast. The hypoblast gives rise to the extraembryonic yolk sac and ies with these powerful model systems, as well as others, has yielded key the epiblast to the amnion and the three germ layers of the embryo, insights into human vascular embryology and angiogenesis. known as the endoderm, mesoderm, and ectoderm. The epiblast is Although blood vessels are composed of three tissue layers, the vast divided into these layers in the process of gastrulation when many majority of the vascular-development literature has focused on the of the embryonic epiblast cells invaginate through the cranial-ca udal morphogenesis of the intima, or inner, layer. This intima consists of primitive streak and become the mesoderm and endoderm, while the a single layer of flat endothelial cells (ECs) that line the vessel lumen cells that remain in the embryonic epiblast become the ectoderm. and are elongated in the direction of flow. Moving radially outward, the Most of the cardiovascular system derives from the mesoderm, in- next layer is the media consisting of layers of circumferentially oriented cluding the initial ECs, which are first observed during gastrulation. vascular smooth muscle cells (VSMCs) and extracellular matrix (ECM) A notable exception to the mesodermal origin is the SMCs of the components, including elastin and collagen. In smaller vessels, such aortic arch and cranial vessels, which instead derive from the neural as capillaries, the mural cells consist of pericytes instead of VSMCs. crest cells of the ectoderm.2 1 2 PART I Biology of Blood Vessels Although ECs are thought to derive exclusively from mesodermal angiogenesis is often initiated by EC proliferation, which results in lu- origins, the other germ layers may play an important role in regulating men widening.14 The lumen then splits through transcapillary ECM the differentiation of the mesodermal cells to an EC fate. In a classic pillars or fusion and splitting of capillaries to generate more vessels.14 study of quail-chick intracelomic grafts, host ECs invaded limb bud In addition, the developing vascular tree is fine-tuned by the pruning grafts, whereas in internal organ grafts, EC precursors derived from of small vessels. Although not involved in the construction of the initial the graft itself.3 Thus the authors hypothesized that the endoderm (i.e., vascular plan, flow is an important factor in shaping the maturation from internal organ grafts) stimulates the emergence of ECs from asso- of the vascular system, determining which vessels mature and which ciated mesoderm, whereas the ectoderm (i.e., from the limb bud grafts) regress. For instance, unperfused vessels will regress. may have an inhibitory influence.3 Yet, the endoderm does not appear to be absolutely required for the initial formation of EC precursors.4,5 Arterial and Venous Endothelial Cell Differentiation The initial primitive vascular system is formed prior to the first car- Classically, it was thought that arterial and venous blood vessel iden- diac contraction, and the early development of ECs involves the inter- tity was established as a result of oxygenation and hemodynamic fac- play of multiple signaling pathways.6,7 This early vasculature develops tors, such as blood pressure, shear stress, and the direction of flow. through vasculogenesis, a two-step process in which mesodermal cells However, over the past two decades, it has become increasingly evi- differentiate into angioblasts in situ, which, in turn, subsequently co- dent that arterial-specific and venous-specific markers are segregated alesce into blood vessels.8 Early in this process, many EC progenitors to the proper vessels quite early in the program of vascular morpho- apparently pass through a bipotential hemangioblast stage in which genesis. For instance, ephrinB2, a transmembrane ligand, and one of they can give rise to endothelial or hematopoietic cells. Fibroblast its receptors, the EphB4 tyrosine kinase, are expressed in the mouse growth factor (FGF) 2 and bone morphogenetic protein (BMP) 4 sig- embryo in an arterial-specific and relatively venous-specific man- naling are required for mesoderm specification and its differentiation ner, respectively, prior to the onset of angiogenesis (Fig. 1.1).15–18 toward endothelial and hematopoietic cell fates.7 In addition, Indian EphrinB2 and EphB4 are each required for normal angiogenesis of hedgehog is secreted by the yolk sac visceral endoderm during vascu- both arteries and veins.16,17 However, in mice homozygous for a tau- logenesis and promotes the differentiation of posterior epiblast cells lacZ knock-in into the ephrinB2 or EphB4 locus (which renders the into both endothelial and hematopoietic cells.9,10 The visceral endo- mouse null for the gene of interest), lacZ staining is restricted to ar- derm also secretes vascular endothelial growth factor (VEGF), which is teries or veins, respectively.16,17 This result indicates that neither of widely implicated in EC biology. The ligand VEGF-A signals predomi- these signaling partners is required for the arterial and venous spec- nantly through receptor VEGFR2, and Veg fr2-null embryos lack blood ification of ECs. vessel islands and vasculogenesis and die in utero.11 Importantly, most Furthermore, even before initial ephrinB2 and EphB4 expression genes that specify an EC fate contain binding sites for the E-twenty-six and prior to the first heartbeat,
Load more

Recommended publications
  • Coronary Arterial Development Is Regulated by a Dll4-Jag1-Ephrinb2 Signaling Cascade
    RESEARCH ARTICLE Coronary arterial development is regulated by a Dll4-Jag1-EphrinB2 signaling cascade Stanislao Igor Travisano1,2, Vera Lucia Oliveira1,2, Bele´ n Prados1,2, Joaquim Grego-Bessa1,2, Rebeca Pin˜ eiro-Sabarı´s1,2, Vanesa Bou1,2, Manuel J Go´ mez3, Fa´ tima Sa´ nchez-Cabo3, Donal MacGrogan1,2*, Jose´ Luis de la Pompa1,2* 1Intercellular Signalling in Cardiovascular Development and Disease Laboratory, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain; 2CIBER de Enfermedades Cardiovasculares, Madrid, Spain; 3Bioinformatics Unit, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain Abstract Coronaries are essential for myocardial growth and heart function. Notch is crucial for mouse embryonic angiogenesis, but its role in coronary development remains uncertain. We show Jag1, Dll4 and activated Notch1 receptor expression in sinus venosus (SV) endocardium. Endocardial Jag1 removal blocks SV capillary sprouting, while Dll4 inactivation stimulates excessive capillary growth, suggesting that ligand antagonism regulates coronary primary plexus formation. Later endothelial ligand removal, or forced expression of Dll4 or the glycosyltransferase Mfng, blocks coronary plexus remodeling, arterial differentiation, and perivascular cell maturation. Endocardial deletion of Efnb2 phenocopies the coronary arterial defects of Notch mutants. Angiogenic rescue experiments in ventricular explants, or in primary human endothelial cells, indicate that EphrinB2 is a critical effector of antagonistic Dll4 and Jag1 functions in arterial morphogenesis. Thus, coronary arterial precursors are specified in the SV prior to primary coronary plexus formation and subsequent arterial differentiation depends on a Dll4-Jag1-EphrinB2 signaling *For correspondence: [email protected] (DMG); cascade. [email protected] (JLP) Competing interests: The authors declare that no Introduction competing interests exist.
    [Show full text]
  • CCM2 and CCM3 Proteins Contribute to Vasculogenesis and Angiogenesis in Human Placenta
    Histol Histopathol (2009) 24: 1287-1294 Histology and http://www.hh.um.es Histopathology Cellular and Molecular Biology CCM2 and CCM3 proteins contribute to vasculogenesis and angiogenesis in human placenta Gamze Tanriover1, Yasemin Seval1, Leyla Sati1, Murat Gunel2 and Necdet Demir1 1Department of Histology and Embryology, Akdeniz University, School of Medicine, Antalya, Turkey and 2 Department of Neurosurgery, Yale University, School of Medicine, New Haven, CT, USA Summary. Placenta as an ideal model to study Introduction angiogenic mechanisms have been established in previous studies. There are two processes, The placenta is a multifaceted organ that plays a vasculogenesis and angiogenesis, involved in blood critical role in maintaining and protecting the developing vessel formation during placental development. fetus. Normal development and function of the placenta Therefore, blood vessel formation is a crucial issue that requires extensive vasculogenesis and subsequent might cause vascular malformations. One of the vascular angiogenesis, in both maternal and fetal tissues. malformations is cerebral cavernous malformation Vasculogenesis is the formation of the primitive vascular (CCM) in the central nervous system, consisting of network de novo from progenitor cells, and angiogenesis endothelium-lined vascular channels without intervening is identified as the extension of blood vessels from normal brain parenchyma. Three CCM loci have been preexisting vascular structures (Demir et al., 1989, 2006; mapped as Ccm1, Ccm2, Ccm3 genes in CCM. In order Geva et al., 2002; Charnock-Jones et al., 2004). Many to investigate whether CCM proteins participate in blood factors, such as vascular endothelial growth factor vessel formation, we report here the expression patterns (VEGF), angiopoietins (Angpt-1 and -2) and their of CCM2 and CCM3 in developing and term human receptors are involved in the molecular regulation of placenta by means of immunohistochemistry and these diverse developmental steps.
    [Show full text]
  • Fetal Blood Flow and Genetic Mutations in Conotruncal Congenital Heart Disease
    Journal of Cardiovascular Development and Disease Review Fetal Blood Flow and Genetic Mutations in Conotruncal Congenital Heart Disease Laura A. Dyer 1 and Sandra Rugonyi 2,* 1 Department of Biology, University of Portland, Portland, OR 97203, USA; [email protected] 2 Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA * Correspondence: [email protected] Abstract: In congenital heart disease, the presence of structural defects affects blood flow in the heart and circulation. However, because the fetal circulation bypasses the lungs, fetuses with cyanotic heart defects can survive in utero but need prompt intervention to survive after birth. Tetralogy of Fallot and persistent truncus arteriosus are two of the most significant conotruncal heart defects. In both defects, blood access to the lungs is restricted or non-existent, and babies with these critical conditions need intervention right after birth. While there are known genetic mutations that lead to these critical heart defects, early perturbations in blood flow can independently lead to critical heart defects. In this paper, we start by comparing the fetal circulation with the neonatal and adult circulation, and reviewing how altered fetal blood flow can be used as a diagnostic tool to plan interventions. We then look at known factors that lead to tetralogy of Fallot and persistent truncus arteriosus: namely early perturbations in blood flow and mutations within VEGF-related pathways. The interplay between physical and genetic factors means that any one alteration can cause significant disruptions during development and underscore our need to better understand the effects of both blood flow and flow-responsive genes.
    [Show full text]
  • PDF Published Online: 21 May 2010
    Int. J. Dev. Biol. 54: 1033-1043 (2010) DEVELOPMENTALTHE INTERNATIONAL JOURNAL OF doi: 10.1387/ijdb.103105gs BIOLOGY www.intjdevbiol.com Primitive and definitive erythropoiesis in the yolk sac: a bird’s eye view GUOJUN SHENG* Laboratory for Early Embryogenesis, RIKEN Center for Developmental Biology, Kobe, Hyogo, Japan ABSTRACT The yolk sac is the sole niche and source of cells for primitive erythropoiesis from E1 to E5 of chicken development. It is also the main niche and source of cells for early definitive erythropoiesis from E5 to E12. A transition occurs during late embryonic development, after which the bone marrow becomes the major niche and intraembryonically-derived cells the major source. How the yolk sac is involved in these three phases of erythropoiesis is discussed in this review. Prior to the establishment of circulation at E2, specification of primitive erythrocytes is discussed in relation to that of two other cell types formed in the extraembryonic mesoderm, namely the smooth muscle and endothelial cells. Concepts of blood island, hemangioblast and hemogenic endothelium are also discussed. It is concluded that the chick embryo remains a powerful model for studying developmental hematopoiesis and erythropoiesis. KEY WORDS: chicken, primitive erythropoiesis, definitive erythropoiesis, hematopoiesis, yolk sac Introduction 2003; Siatskas and Boyd, 2000), hematological description of different blood lineages (Lucas and Jamroz, 1961), early vascular Studies on chicken hematopoietic development have been morphogenesis (Drake, 2003; Drake et al., 1998; Drake et al., instrumental in the establishment of several key concepts in the 2000) and developmental and adult immune systems (Davison et field, including B lymphocytes, hematopoietic stem cells, al., 2008).
    [Show full text]
  • Problem Is Also Further Confused by the Perplexing Mixture of Cells of Different Origin Brought About by the Early Established Circulation of the Body Fluids
    556 ZOOLOGY: C. R. STOCKARD composition. Coralium and Tubipora, for example, are compact forms, with little organic matter; and they are lower in magnesia than the genera with horny, organic axes, such as appear at the eric of the table. It is also noteworthy that the highest proportions of calcium phosphate are commonly found associated with high values for magnesia. 1 Published by permission of the Director of the U. S. Geological Survey. AN EXPERIMENTAL ANALYSIS OF THE ORIGIN AND RELA- TIONSHIP OF BLOOD CORPUSCLES AND THE LINING CELLS OF VESSELS By Charles R. Stockard DEPARTMENT OF ANATOMY, CORNELL UNIVERSITY MEDICAL SCHOOL Preented to the Academy. September 29. 1915 Studies on the origin and development of the cellular elements of the blood and the so-called endothelial cells which line the blood vessels in the normal embryo are peculiarly difficult on account of the important r61e that wandering mesenchyme cells play in these processes. The problem is also further confused by the perplexing mixture of cells of different origin brought about by the early established circulation of the body fluids. The development of no other embryonic tissue is so disturbed by mechanical and physical conditions. A study of living fish embryos with the high power microscope has made it possible to observe the behavior of the wandering cells and to follow them in their development. The disadvantages due to the inter- mixture of cells in the blood current have been overcome by the investi- gation of embryos in which a circulation of the blood is prevented from taking place. When the eggs of the fish, Fundulus heteroclitus, are treated during early developmental stages with weak solutions of alcohol, the resulting embryos in many cases never establish a blood circulation.
    [Show full text]
  • Extensive Vasculogenesis, Angiogenesis, and Organogenesis Precede Lethality in Mice Lacking All V Integrins
    Cell, Vol. 95, 507–519, November 13, 1998, Copyright ©1998 by Cell Press Extensive Vasculogenesis, Angiogenesis, and Organogenesis Precede Lethality in Mice Lacking All ␣v Integrins Bernhard L. Bader,*‡ Helen Rayburn,* their ligands. Significant expression of ␣v integrins has Denise Crowley,* and Richard O. Hynes*† been noted, in particular, in neural crest cells (Delannet * Howard Hughes Medical Institute et al., 1994), glial cells (Hirsch et al., 1994; Milner and Center for Cancer Research ffrench-Constant, 1994), muscle (Hirsch et al., 1994; Mc- and Department of Biology Donald et al., 1995; Martin and Sanes, 1997), osteoclasts Massachusetts Institute of Technology (Va¨ a¨ na¨ nen and Horton, 1995), epithelia (␣v␤6; Breuss et Cambridge, Massachusetts 02139 al., 1995; Huang et al., 1996), and blood vessels during development (Brooks et al., 1994a; Drake et al., 1995; Friedlander et al., 1995, 1996) or angiogenesis in re- Summary sponse to tumors (Brooks et al., 1994a, 1994b, 1996, 1998; Varner et al., 1995). ␣v integrins have been implicated in many develop- Among the ligands for various ␣v␤ integrins is fibro- mental processes and are therapeutic targets for inhi- nectin (FN), and results on mouse embryos lacking FN bition of angiogenesis and osteoporosis. Surprisingly, or FN receptor integrins suggest that ␣v integrins might ablation of the gene for the ␣v integrin subunit, elimi- be important receptors for FN during early development. nating all five ␣v integrins, although causing lethality, FN-null embryos fail to form notochord or somites allows considerable development and organogenesis (George et al., 1993; Georges-Labouesse et al., 1996), including, most notably, extensive vasculogenesis and whereas embryos null for either (Yang et al., 1993, 1995) angiogenesis.
    [Show full text]
  • Copyright by Steven A. Vokes 2002 the Dissertation Committee for Steven Alexander Vokes Certifies That This Is the Approved Version of the Following Dissertation
    Copyright by Steven A. Vokes 2002 The Dissertation Committee for Steven Alexander Vokes Certifies that this is the approved version of the following dissertation: The Role of Endoderm in Vascular Patterning Committee: Janice A. Fischer, Supervisor Paul A. Krieg , Co-Supervisor Alan M. Lloyd Arlen W. Johnson S. Martin Shankland R. Adron Harris The Role of Endoderm in Vascular Patterning by Steven Alexander Vokes, B.A. Dissertation Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy The University of Texas at Austin December, 2002 Dedication This work, symbolic of my higher education, is dedicated to my parents Carol and Emmett Vokes, who played such an integral role in its foundations. Acknowledgements I have been extremely fortunate to have excellent mentoring during my time in graduate school. I thank Paul Krieg for his suggestions, enthusiasm, encouragement and friendship during this learning process. He has taught me how to think (and write) critically and insightfully about science. I am also grateful to Amy Cheng Vollmer, my undergraduate mentor. She introduced me to the joys of scientific research, and continues to give me excellent advice whenever I need it most. I thank Peter Vize, whose conversations led to the first experiments described within. In daily interactions, I have benefited from a caste of talented co-workers and advisors. These include Craig Newman, Wendy Gerber, Ondine Cleaver, Tom Carroll, Eric Small, Rob Garriock, Martha Joe, Parker Antin, Ray Runyan, Jean Wilson, Carol Gregorio and all past and present members of the Krieg lab.
    [Show full text]
  • Glossary of Key Terms and Concepts - Chapter 8
    Glossary of Key Terms and Concepts - Chapter 8 Angioblasts - These "vessel-forming cells" may arise from any kind of mesoderm except prechordal plate mesoderm. Angioblastic cords - Angiocysts coalesce to form short blind-ended angioblastic cords. Angioblastic plexuses - Angioblastic cords coalesce to form complex interconnected vascular networks or plexuses. Angiocysts - These vesicles are formed by angioblasts during the process of vasculogenesis. Angiogenesis - This is the mechanism whereby preexisting vessels lengthen or branch by sprouting. Aortic arches - These vessels have been modified in humans to form the great vessels of the thorax (also see Ch. 7). Axis arteries - These central arteries of the limbs are derived from the 7th intersegmental arteries (upper limb) and 5th lumbar intersegmental arteries (lower limb). Blood islands - Blood islands are cysts of angioblasts containing hemoblasts. These coalesce to form blood vessels in the yolk sac and also form the coronary vasculature. Branchial arches - These are the gill bars of fish. Homologous structures of humans are more appropriately named "pharyngeal" arches. Cardinal system of veins - These veins drain the head and neck and body wall and extremities of the embryo. Anterior cardinals drain the head and neck and the trunk and lower extremities are drained by paired posterior cardinals. The posterior cardinal veins are replaced by subcardinal and supracardinal veins during the second month. Coronary vessels - These vessels of the heart form from epicardium as subepicardial plexuses fuse with sprouts of the aorta and coronary sinus to form the coronary arteries and coronary veins respectively. Endothelial cells - These cells arise from angioblasts to form the initial vascular network.
    [Show full text]
  • VEGFR-3 in Angiogenesis and Lymphangiogenesis
    VEGFR-3 in Angiogenesis and Lymphangiogenesis Lotta Jussila Molecular/Cancer Biology Laboratory Haartman Institute and Helsinki University Central Hospital Biomedicum Helsinki University of Helsinki Finland Academic dissertation To be publicly discussed, with the permission of the Medical Faculty of the University of Helsinki, in the lecture hall 3 of the Biomedicum Helsinki, Haartmaninkatu 8, Helsinki, on December 14th, 2001 at 12 o´clock noon. Helsinki, 2001 Supervised by Dr. Kari Alitalo Molecular/Cancer Biology Laboratory University of Helsinki Reviewed by Dr. Ulf Eriksson Ludwig Institute for Cancer Research Karolinska Institute and Dr. Hannu Sariola Institute of Biomedicine University of Helsinki Opponent Dr. Christer Betsholtz Department of Medical Biochemistry University of Göteborg ISBN 952-91-4175-0 (nid.) ISBN 952-10-0241-7 (pdf) Multiprint Oy Helsinki VEGFR-3 in Angiogenesis and Lymphangiogenesis 1 Contents Contents............................................................................................................. 1 Abbreviations ....................................................................................................... 2 List of Original Publications ...................................................................................... 3 Abstract ............................................................................................................. 4 Review of the literature .......................................................................................... 5 Blood vessel development ...........................................................................
    [Show full text]
  • EXTRACORONARY CARDIAC VEINS in the RAT1 the Present Work
    EXTRACORONARY CARDIAC VEINS IN THE RAT1 MYRON H. HALPERN Department of Anatomy, Unit-ersity of Michigan, Ann Arbor SIX FIGURES The present work had its inception in the discovery of vessels around the rat’s heart which did not correspond to anything previously described in other mammals. These ves- sels are a system of veins which begin on the heart and terminate in the anterior venae cavae. Two major veins eom- prise this system, each of which crosses the midline to empty into the contralateral anterior vena cava. They drain the conal region of the right ventricle and the ventrocephalic region of the left ventricle. The term “extracoronary” cardiac veins has been applied to these vessels by the author because they originate on the heart and terminate in remote vessels not otherwise associated with the coronary circulation. Al- though this system has been found to exist in certain fishes and amphibians, to the author’s knowledge it has never been recognized in mammals. These findings seemed to warrant a more detailed study of the adult cardiac venous drainage of the rat. To supplement this portion of the investigation, an embryologic study was undertaken. Both the adult and the embryonic patterns of the cardiac drainage were com- pared with the patterns found in the above vertebrates and were interpreted on the basis of these comparisons. MATERIAL AND METHODS For this study, the venous system of 85 adult rats were injected with latex preparatory to dissection. Of this number, Portion of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the University of Michigan.
    [Show full text]
  • Azygos Vein System Abnormality: Case Report
    Gülhane Týp Dergisi 2006; 48: 180-182 OLGU SUNUMU © Gülhane Askeri Týp Akademisi 2006 Azygos vein system abnormality: case report Necdet Kocabýyýk (*), Tunç Kutoðlu (**), Soner Albay (*), Bülent Yalçýn (*), Hasan Ozan (*) Summary Introduction Variations seen in the thoracic vein system are Abnormalities related to the azygos system are not rare (1). In a series related to the development of these veins. of 200 cases, Bergman et al. have reported the incidence of this anomaly During the dissection from the posterior medi- astinum of the 60-year-old male cadaver, it 26% (2). These abnormalities are generally explained by the embryolog- was observed that there was no complete ical development. Venous branching of the azygos vein varies (3). There accessory hemiazygos vein, and both posterior are two origins of the azygos and hemiazygos veins. By union of these intercostal veins and hemiazygos vein (above origins and regression of some parts, azygos system comes into its final T10 level) drained bilaterally to the azygos vein. Considering these types of variations is status (4). Different types of structures may occur when these veins important during imaging this region and surgi- develop. Abnormalities about azygos system and especially the variations cal operations. of the hemiazygos veins are not clearly described in the literature. In this Key words: Azygos vein, hemiazygos vein, superior vena cava, venous anomaly presentation absence of the accessory hemiazygos vein and possible causes of these types of variations are discussed in view of the embry- Özet ological development. Azigos ven sistem anomalisi: olgu sunumu Toraks ven sisteminde görülen varyasyonlar, embriyolojik olarak bu venlerin geliþimiyle ilgi- Case Report lidir.
    [Show full text]
  • Secretion of Placental Growth Factor Promotes Angiogenesis by Enhanced Fibroblast-Like Synoviocytes Via Cadherin-11 Interaction
    Interaction of Mesenchymal Stem Cells with Fibroblast-like Synoviocytes via Cadherin-11 Promotes Angiogenesis by Enhanced Secretion of Placental Growth Factor This information is current as of September 23, 2021. Su-Jung Park, Ki-Jo Kim, Wan-Uk Kim and Chul-Soo Cho J Immunol 2014; 192:3003-3010; Prepublished online 26 February 2014; doi: 10.4049/jimmunol.1302177 http://www.jimmunol.org/content/192/7/3003 Downloaded from References This article cites 50 articles, 15 of which you can access for free at: http://www.jimmunol.org/content/192/7/3003.full#ref-list-1 http://www.jimmunol.org/ Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication by guest on September 23, 2021 *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts Errata An erratum has been published regarding this article. Please see next page or: /content/192/10/4932.full.pdf The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2014 by The American Association of Immunologists, Inc. All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. The Journal of Immunology Interaction of Mesenchymal Stem Cells with Fibroblast-like Synoviocytes via Cadherin-11 Promotes Angiogenesis by Enhanced Secretion of Placental Growth Factor Su-Jung Park,* Ki-Jo Kim,† Wan-Uk Kim,*,† and Chul-Soo Cho*,‡ Bone marrow–derived mesenchymal stem cells (MSC) exist in the synovium of patients with rheumatoid arthritis (RA), yet the role of MSC in RA is elusive.
    [Show full text]