kaolinite and Intestinal-Diseases

Topics: Clinical Trials as Topic; Female; Humans; Intestinal Diseases; Kaolin; Male; Neoplasms; Radiation Injuries

Macrophages at the base of human gut associated lymphoid tissue (GALT), become loaded early in life with dark granular pigment that is rich in aluminium, silicon, and titanium. The molecular characteristics, intracellular distribution, and source of this pigment is described. Laser scanning and electron microscopy showed that pigmented macrophages were often closely related to collagen fibres and plasma cells in GALT of both small and large intestine and contained numerous phagolysosomes, previously described as granules, that are rich in electron dense submicron sized particles. Morphological assessment, x ray microanalysis, and image electron energy loss spectroscopy showed three distinct types of microparticle: type I - spheres of titanium dioxide, 100-200 nm diameter, characterised as the synthetic food-additive polymorph anatase; type II - aluminosilicates, < 100-400 nm in length, generally of flaky appearance, often with adsorbed surface iron, and mostly characteristic of the natural clay mineral kaolinite; and type III - mixed environmental silicates without aluminium, 100-700 nm in length and of variable morphology. Thus, this cellular pigment that is partly derived from food additives and partly from the environment is composed of inert inorganic microparticles and loaded into phagolysosomes of macrophages within the GALT of all human subjects. These observations suggest that the pathogenicity of this pigment should be further investigated since, in susceptible individuals, the same intracellular distribution of these three types of submicron particle causes chronic latent granulomatous inflammation.

Topics: Aluminum Silicates; Colitis, Ulcerative; Colonic Neoplasms; Crohn Disease; Electron Probe Microanalysis; Humans; Intestinal Diseases; Kaolin; Macrophages; Microscopy, Electron; Peyer's Patches; Pigments, Biological; Spectrum Analysis; Titanium

The efficacy of various adsorbents for endotoxin was tested in vitro and in vivo using a murine experimental model of gut-derived endotoxemia. A quantitative limulus amebocyte lysate microtiter test and the limulus amebocyte lysate tube test were used to determine intestinal and circulating levels of endotoxin. Kaopectate, kaolin/pectin mixture, kaolin, pectin, bentonite, charcoal particles, and lactulose were tested for their ability to bind endotoxins both in vitro and in vivo. The most effective material in the prevention of endotoxemia provided to be bentonite followed by Kaopectate and charcoal particles. Kaolin least effectively bound endotoxin at similar concentrations, while lactulose and pectin had minimal effects. Good correlation was shown between the ability of these drugs to bind endotoxin in vitro as compared with in vivo action.

Topics: Aluminum Silicates; Animals; Bentonite; Charcoal; Endotoxins; Escherichia coli; Female; In Vitro Techniques; Intestinal Diseases; Kaolin; Lactulose; Mice; Mice, Inbred Strains; Toxemia