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Adhesion And Endocytosis Of Calcium Oxalate Crystals On Renal Tubular Cells, Y. Kohjimoto, S. Ebisuno, M. Tamura, T. Ohkawa

Scanning Microscopy

The present investigation was designed to study interactions between Madin-Darby canine kidney (MOCK) cells and calcium oxalate monohydrate (COM) crystals and to clarify the significance of these crystal-cell interactions in stone pathogenesis.

MOCK cells cultured in the presence of COM crystals showed a time-dependent uptake of crystals; this was specific for COM crystals. In the dynamic model system designed to study these phenomena under more physiological conditions, COM crystals adhered to the cell surface and were subsequently internalized. In this endocytotic process, the microvilli of the cell appeared to play an important role. The observation by scanning electron microscopy of …

Role Of Calcium Oxalate Monohydrate Crystal Interactions With Renal Epithelial Cells In The Pathogenesis Of Nephrolithiasis: A Review, John C. Lieske, Mary S. Hammes, F. Gary Toback

Scanning Microscopy

Renal tubular fluid in the distal nephron is supersaturated with calcium and oxalate ions that nucleate to form crystals of calcium oxalate monohydrate (COM), the most common crystal in renal stones. How these nascent crystals are retained in the nephron to form calculi in certain individuals is not known. Recent studies from this laboratory have demonstrated that COM crystals can bind within seconds to the apical surface of renal epithelial cells, suggesting one mechanism whereby crystals could be retained in the tubule. Adherence of crystals to cells along the nephron may be opposed by specific urinary anions such as glycosaminoglycans, …

In Vivo Early Plaque Colonization On Smooth Titanium Surface, A. Carrassi, A. Sardella, L. Rimondini

Cells and Materials

Plaque development on pure titanium in a 24-hour period is described in an in vivo human model. Stents with titanium and root cementum specimens were applied to volunteers, who suspended oral hygiene procedures for 24 hours. The specimens were removed at 2, 4 and 24 hours and studied with a scanning electron microscope. A global area of 240 µm x 300 µm, composed of the sum of twelve 20 µm x 25 µm fields randomly selected, was examined for each specimen. The presence of cocci, short rods, long rods and bacterial aggregation, and bacteria density was recorded for each field. …

The Effect Of Vitronectin And Other Extracellular Matrix Molecules On Endothelial Expansion And Plasminogen Activation, P. Anne Underwood, Penny A. Bean

Cells and Materials

Endothelial recovery following procedures used to alleviate blood vessel occlusion is modulated by the local extracellular matrix upon which it has to migrate and proliferate. This extracellular material is derived from vessel wall cells, and plasma proteins which bind to the exposed surfaces. We have demonstrated that vitronectin adsorbs efficiently to tissue culture polystyrene in competition with other plasma proteins, which suggests that it may adsorb to biomaterial surfaces in vivo. We have compared the adhesion, migration and proliferation of human umbilical artery endothelial cells on surface-coated vitronectin, with other extracellular matrix molecules encountered in this environment, namely fibronectin, …