Endothelial cells were prepared from bovine microvessels and grown in tissue culture. They contained factor VIII/von Willebrand antigen, the most specific market available for determination of the endothelial origin of cells in culture. The cultured cells formed complex tight junctions and contained few pinocytotic vessels. These properties are responsible for formation of the blood-brain barrier in vivo. When monolayers of the endothelial cells were exposed briefly to a calcium-free solution or treated with 1.6 M arabinose, distinctive morphological changes occurred in the intercellular contacts. In either case, a normal structure was reestablished following return to control medium. To assess the effect of these treatments on transcellular permeability, we measured the movement of sucrose labeled with carbon 14 across a monolayer of endothelial cells cultured on a collagen-coated nylon mesh. Removal of external calcium increased the rate of sucrose movement by 120%; the arabinose treatment increased transcellular flux by 40%.
Anatomy and physiology are taught in community colleges, liberal arts colleges, universities, and medical schools. The goals of the students vary, but educators in these diverse settings agree that success hinges on learning concepts rather than memorizing facts. In this article, educators from across the postsecondary educational spectrum expand on several points: (1) There is a problem with student perception that anatomy is endless memorization, whereas the ability to manage information and use reasoning to solve problems are ways that professionals work. This misperception causes students to approach the subject with the wrong attitude. (2) The process of learning to use information is as important as the concepts themselves. Using understanding to explain and make connections is a more useful long-term lesson than is memorization. Anatomy should be presented and learned as a dynamic basis for problem solving and for application in the practice and delivery of quality health care. (3) Integration of form and function must be explicit and universal across all systems. (4) Using only models, images, audiovisuals, or computers cannot lead students to the requisite reasoning that comes from investigative dissection of real tissue. (5) Some undergraduate courses require students to memorize excessive musculoskeletal detail. (6) Learning tissue biology is a particular struggle for medical students who have no background from an undergraduate course. (7) Medical professors and students see benefits when students have taken undergraduate courses in anatomy, histology, and physiology. If medical schools suggest these electives to applicants, medical students might arrive better prepared and, thus, be able to learn clinical correlations more efficiently in the limited allocated time of medical school curricula.
Glucocorticoid receptors were detected in the human inner ear. The highest concentration of glucocorticoid receptor protein was measured by enzyme-linked immunosorbent assay in the spiral ligament tissues; the lowest concentration of glucocorticoid receptors was measured in the macula of the saccule. The demonstration of the presence of glucocorticoid receptors in human Inner ear tissues provides a basis to consider the direct effects of glucocorticoid action on select inner ear cells, rather than assuming a systemic antiinflammatory or immunosuppressive effect during the therapeutic treatment of patients with given inner ear disorders.
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