zeolites and illite

Malignant melanoma of the eye is an uncommon condition that is important to recognise. We describe three cases in which ocular foreign bodies have masqueraded as ocular malignant melanoma.. Interventional case reports.. Case 1 describes diathermy-induced carbon particle implantation, during plaque therapy for the treatment of uveal melanoma, mimicking recurrence with extra-scleral invasion. Case 2 shows a foreign body called 'mullite' mimicking conjunctival melanoma. Case 3 demonstrates a conjunctival foreign body called 'illite' that mimicked a limbal melanocytic lesion, clinically thought to be either melanocytoma or melanoma.. This report highlights the importance of careful history taking, examination, and appropriate biopsy in cases of suspected malignant melanoma, to prevent unnecessary and potentially radical treatment.

Topics: Adult; Aluminum Silicates; Carbon; Conjunctiva; Conjunctival Neoplasms; Diagnosis, Differential; Eye Foreign Bodies; Eye Injuries; Female; Humans; Male; Melanoma; Middle Aged; Minerals; Spectrometry, X-Ray Emission; Wounds, Nonpenetrating

The objective of this work was to coat aluminosilicate clays on an inert silica support, and to characterize the properties and stability of the clay-silica coating. Two polymers, polyacrylamide (PAM) and polyvinyl alcohol (PVA), were used to bind kaolinite, illite, and smectite onto silica grains. The clay-polymer composites were studied by X-ray diffraction, FTIR, and electrophoretic mobility. Clay coatings on silica grains were characterized by mass coverage, scanning electron microscopy, specific surface area, and pH stability. Silica sand was successfully coated with clays by using the two polymers, but with PVA, the clay coating had a greater mass coverage and was more stable against pH variations. Less polymer was needed for the clay coating using PVA as compared to using PAM. Clay-polymer complexes and pure clay minerals had similar cation exchange capacities and electrophoretic mobilities, indicating that overall surface charge of the clays was little affected by the polymers. Some decrease in hydrophilicity was observed for illite and smectite when clays where coated with the polymers. The methodology reported here allows the generation of a clay-based porous matrix, with hydraulic properties that can be varied by adjusting the grain size of the inert silica support.

Topics: Acrylic Resins; Adsorption; Aluminum Silicates; Clay; Electrophoresis; Hydrogen-Ion Concentration; Ion Exchange; Kaolin; Microscopy, Electron, Scanning; Minerals; Particle Size; Polyvinyl Alcohol; Silicates; Silicon Dioxide; Spectroscopy, Fourier Transform Infrared; Surface Properties; X-Ray Diffraction