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Crystallization During Volume Reduction Of Solutions With An Ion-Composition Corresponding To That In The Distal Tubuli, Inge Hojgaard, Anne-Marie Fornander, Mari-Anne Nilsson, Hans Goran Tiselius
Crystallization During Volume Reduction Of Solutions With An Ion-Composition Corresponding To That In The Distal Tubuli, Inge Hojgaard, Anne-Marie Fornander, Mari-Anne Nilsson, Hans Goran Tiselius
Scanning Microscopy
The effect of macromolecules on the crystallization in solutions with an ion-composition and a pH corresponding to that of urine in the distal part of the distal tubuli was examined by recording the number and volume of crystals in a Coulter Multisizer and by studying the crystal morphology with scanning electron microscopy at different degrees of evaporation. The experiments were carried out with 100 ml samples of salt solutions with and without different concentrations of dialysed urine (dU) from normal subjects. Addition of dU resulted in a greater number of crystals and a reduction in the mean crystal volume (MCV). …
The Nucleation And Growth Of Calcium Phosphate Crystals At Protein And Phosphatidylserine Liposome Surfaces, G. H. Nancollas, A. Tsortos, A. Zieba
The Nucleation And Growth Of Calcium Phosphate Crystals At Protein And Phosphatidylserine Liposome Surfaces, G. H. Nancollas, A. Tsortos, A. Zieba
Scanning Microscopy
The kinetics of calcium phosphate crystal growth at the surfaces of proteins and phospholipids has been investigated using free drift and constant composition methods in supersaturated calcium phosphate solutions (relative supersaturations: with respect to hydroxyapatite, HAP, σHAP = 15.0, and with respect to octacalcium phosphate, OCP, σOCP = 1. 9). Fibrinogen and collagen molecules adsorbed at hydrophobic surfaces as well as uncross-linked collagen fibrils induce ion binding and subsequent nucleation of calcium phosphate. The formation of OCP on phosphatidylserine vesicles introduced to highly supersaturated calcium phosphate solutions probably involves the interaction of the calcium ions with the ionized carboxylic groups …
Formation Of Hydrated Calcium Oxalates In The Presence Of Poly-L-Aspartic Acid, Jeffrey A. Wesson, Elaine Worcester
Formation Of Hydrated Calcium Oxalates In The Presence Of Poly-L-Aspartic Acid, Jeffrey A. Wesson, Elaine Worcester
Scanning Microscopy
The effect of poly-L-aspartic acid (PA) on the crystal structure of calcium oxalate crystals grown after spontaneous nucleation was evaluated as a function of relative supersaturation and calcium:oxalate ratio in a buffered salt solution, with pH and ionic strength in the range of normal human urine. PA was used as a model for naturally occurring acidic urine proteins that have been shown to inhibit nucleation and growth of calcium oxalate crystals. The crystals grown were characterized by optical microscopy and X-ray powder diffraction. It was observed that calcium oxalate monohydrate was the preferred crystalline form in the absence of added …
Crystallization And Stone Formation Inside The Nephron, Dirk J. Kok
Crystallization And Stone Formation Inside The Nephron, Dirk J. Kok
Scanning Microscopy
A model is presented visualizing the events leading to calcium-salt, crystal- and stone-formation inside the nephron. For each nephron segment, handling of urine components relevant to stone formation is considered and urine composition determined. This information was applied to nucleation experiments simulating passage of urine through a nephron. The model and in vitro experiments suggest that within normal transit times for the respective nephron segments, particles of a hydroxyapatite-like material first form near the bend in the Loop of Henle of juxtamedullary nephrons. From there on, calcium oxalate particles start to appear: first dihydrate, then monohydrate. In the collecting duct …