A review of the literature on the histogenesis and function of the carotid body suggests that the results and the original interpretations of embryological, histological and histochemical investigations have not provided a convincing explanation of the origin of this structure. That the carotid body is developed from mesoderm and is a sensory organ (chemoreceptor) seems unlikely because of: morphological similarities between some of the carotid body tumours and certain tumours of peripheral nerves; certain electron microscopic similarities between the cells of carotid body and adrenal medulla; chromatographic demonstration of catecholamines in the human carotid bodies; and contradictory results of both animal experiments and clinical observations concerning function of this structure.It is concluded that the carotid body arises from ectoderm and should probably be classified as a gland of internal secretion, related to the adrenal medulla and other paraganglia. (+info)
Prof. Eber Landau, the very first chief of Histology and Embryology Department at the University of Lithuania.
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The article deals with the scientific activities of professor Eber Landau carried out in Estonia, Lithuania and Switzerland. Professor E. Landau was born November 8, 1878, in a merchant's family in Rezekne, Latvia. On leaving a classical high school in Riga, E. Landau studied at the Medical Faculty of Tartu University, graduating it in 1902. Later he improved his qualification in histology and anatomy at Villafrenk Zoology station, at the Histology Laboratory in Munich, and in St. Petersburg under the guidance of professor P. Leshaft. In 1906-1912 Landau worked as a prosector assistant at the Anatomy Institute, headed by professor A. Rauber, Tartu University. In 1912 he was elected a director of the Anthropology Institute, Tartu. On the outbreak of the First World War, E. Landau, as a Russian citizen, was called to the army and served as a neurologist and psychiatrist in Paris military hospitals. In 1918, E. Landau returned to Bern and for 5 years worked at the Anatomy Institute headed by prof. H. Strasner. In December 1, 1923, E. Landau moved to Kaunas University. Here he established the Department of Histology and Embryology and headed the Department till 1932. From 1932 till 1950 Eber Landau worked as a professor at the University of Lausanne. Professor E. Landau retired in 1950, but he still continued his research work in the field of neurohistology. Professor E. Landau died October 30, 1959. He left behind him an ample scientific heritage: 175 scientific publications and 12 doctoral theses done under his guidance. (+info)
Molecular markers of cardiac endocardial cushion development.
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Endocardial cushions are precursors of mature heart valves. They form within the looped heart tube as discrete swellings and develop into thin, pliable leaflets that prevent regurgitation of blood. The embryonic origins of cardiac valves include endothelial, myocardial, and neural crest cells. Recently, an increasing number of animal models derived from mutational screens, gene inactivation, and transgenic studies have identified specific molecules required for normal development of the cardiac valves, and critical molecular pathways are beginning to emerge. To further this process, we have sought to assemble a diverse set of molecular markers encompassing all stages of cardiac valve development. Here, we provide a detailed comparative gene expression analysis of thirteen endocardial cushion markers. We identify endocardial cushion expression of the transcription factor Fog1, and we demonstrate active Wnt/beta-catenin signaling in developing endocardial cushions suggesting pathways that have not been previously appreciated to participate in cardiac valve formation. (+info)
ATLAS-plus: multimedia instruction in embryology, gross anatomy, and histology.
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ATLAS-plus [Advanced Tools for Learning Anatomical Structure] is a multimedia program used to assist in the teaching of anatomy at the University of Michigan Medical School. ATLAS-plus contains three courses: Histology, Embryology, and Gross Anatomy. In addition to the three courses, a glossary containing terms from the three courses is available. All three courses and the glossary are accessible in the ATLAS-plus environment. The ATLAS-plus environment provides a consistent set of tools and options so that the user can navigate easily and intelligently in and between the various courses and modules in the ATLAS-plus world. The program is a collaboration between anatomy and cell biology faculty, medical students, graphic artists, systems analysts, and instructional designers. (+info)
Development of the cardiovascular system: an interactive video computer program.
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The major aim of this project is to provide interactive video computer based courseware that can be used by the medical student and others to supplement his or her learning of this very important aspect of basic biomedical education. Embryology is a science that depends on the ability of the student to visualize dynamic changes in structure which occur in four dimensions--X, Y, Z, and time. Traditional didactic methods, including lectures employing photographic slides and laboratories employing histological sections, are limited to two dimensions--X and Y. The third spatial dimension and the dimension of time cannot be readily illustrated using these methods. Computer based learning, particularly when used in conjunction with interactive video, can be used effectively to illustrate developmental processes in all four dimensions. This methodology can also be used to foster the critical skills of independent learning and problem solving. (+info)
Medaka as a research organism: past, present and future.
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This introductory review briefly describes the history of medaka as a research organism and the previous accomplishments of the medaka field. The medaka genome project currently underway through the efforts of an international consortium, the Medaka Genome Initiative, and the future prospects for medaka research, particularly for genomic analyses, are also discussed. (+info)
From eggs to fossils: epigenesis and transformation of species in Pander's biology.
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Christian Heinrich Pander (1794-1865), a Russian scientist of German culture, is known for his epoch-making work in embryology, as well as for his important contributions to palaeontology. Indeed he viewed embryonic development and the history of the earth as two aspects of one and the same essential phenomenon, namely, a perpetual metamorphosis affecting the living world on different scales. He viewed embryology as a gradual, epigenetic transformation (as opposed to preformation) with an intermediary stage, the formation of simple germ-layers. As early as 1821, he argued more generally that species themselves transform under the influence of certain environmental factors. Pander thus embodies the very close link that existed between the triumph of epigenesis and the expansion of transformist theories in the early 19th century. (+info)
Formalizing concepts of species, sex and developmental stage in anatomical ontologies.
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MOTIVATION: Anatomy ontologies have a growing role in bioinformatics-for example, in indexing gene expression data in model organisms. To relate or draw conclusions from data so indexed, anatomy ontologies must be equipped with the formal vocabulary that would allow statements about meronomy to be qualified by constraints such as part of the male or part at the embryonic stage. Lacking such a vocabulary, anatomists have built this information into the structure of the ontology or into anatomical terms. For example, in the FlyBase anatomy for drosophila, the term larval abdominal segment encodes the stage in the term, while the terms male genital disc and female genital disc encode the sex. It remains implicit that a fly has one and only one of these parts during its larval stage. Such indicators of context can and should be represented explicitly in the ontology. RESULTS: The framework we have defined for anatomical ontologies allows the canonical anatomy structures of a given species to be those common to all sexes, and to have either male, female or hermaphrodite parts--but not combinations of the latter. Temporal aspects of development are addressed by associating a stage with organism parts and requiring a connected anatomy to have parts that exist at a common stage. Both sex and anatomical stage are represented by attributes. This formalization clarifies ontological structure and meaning and increases the capacity for formal reasoning about anatomy. The framework also supports generalizations such as vertebrate and invertebrate, thereby allowing the representation of anatomical structures that are common across a sub-phylum. (+info)