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Adsorption studies on clays III. The adsorption of diphtheria toxin by activated attapulgites, halloysite, and kaolin
Abstract
A satisfactory method has been devised which makes it possible to determine the adsorptive capacities of clays for diphtheria toxin. Studies indicate that the activated attapulgites are superior adsorbents for the toxin than halloysite and kaolin. Activated attapulgite HVM was found to be the best adsorbent, seven times more effective than kaolin, and about twice that of halloysite. Studies on intestinal adsorbent suspensions indicate that the activated attapulgites should be investigated clinically as ingredients in these preparations.
... As well as demonstrating that the clay mineral attapulgite (palygorskite) was more effective than kaolinite for the adsorption of alkaloids, bacteria, and toxins, Barr and Arnista (1957) found that halloysite was up to fi ve times more adsorbent than kaolinite for alkaloid and toxin adsorption. This is interesting in the context of animal geophagy since there is a suggestion that halloysite is a "favored" clay. ...
The use of kaolins in health has its origins in prehistoric times. Humans and other animals consume kaolin for gastrointestinal
ailments, digestive enhancement, and possibly nutritional supplementation. Kaolins are effective as hemostatic wound dressings,
because they can clot blood from traumatic injury, with little damage to tissue. Various forms of kaolin have been shown to
be antibacterial, and increasingly kaolins are being utilized in drug delivery. While nanoparticles of kaolin can have deleterious
effects on human tissues, modern understanding of the mineralogy of kaolins and their interactions with human cells allows
many health applications, reaching far beyond the prehistoric “first aid” uses.
The Tomtor massif of Paleozoic ultramafic alkaline rocks and carbonatites is located in the northern part of the Sakha Republic (Yakutia). The massif (its total area is ~ 250 km2) is ~ 20 km in diameter, with a rounded shape and a concentrically zoned structure. The core of the massif consists of carbonatites surrounded by a discontinuous ring of ultramafic rocks and foidolites. The outer part is composed of alkali and nepheline syenites. All rocks are weathered and covered with eluvium, which is the thickest after carbonatites enriched in phosphates and REE. The weathering profile consists of four layers, from the top: kaolinite-crandallite, siderite, goethite, and francolite. The highest-grade ores are observed in the bedded deposit which fills depressions in “sagging” eluvium. The ores are laminated and cryptogranular, with high Nb, Y, Sc, and REE contents (on average, 4.5% Nb2O5, 7-10% REE2O3, 0.75% Y2O3, and 0.06% Sc2O3). The highest-grade ores are natural Nb and REE concentrates. The total REE content in some layers is > 10%. The morphologic features of the highest-grade phosphate ores from the northern part of the Burannyi site were studied. The ore-forming minerals belong to the pyrochlore group, crandallite group (goyazite), and monazite-Ce. The pyrochlore group minerals occur mainly as crystals that were completely replaced by barium-strontium pyrochlore and/or plumbopyrochlore but retained the original faces; also, they occur as numerous conchoidal fragments. The grains of the pyrochlore group minerals sometimes have a zonal structure, with an unaltered pyrochlore core and a reaction rim. Goyazite occurs predominantly as colloform grains. According to SEM and TEM data, monazite occurs in the ores as ~ 50 nm particles, which cover the outer part of halloysite tubes (800–3000 nm long and 300 nm in diameter) as a dense layer and make up peculiar biomorphic aggregates. The mineralogical data, the occurrence of biomorphic aggregates, and the close association of organic remains with ore minerals suggest that the high-grade ores of the Tomtor deposit, including the Burannyi site, resulted from a hydrothermal-sedimentary process with a presumably important role of bioaccumulation of REE phosphates.
Several adsorbent materials were evaluated for their ability to bind Escherichia coli enterotoxins. Cholestyramine, a strong anion-exchange resin, bound the heat-labile and the heat-stable types of enterotoxin and reduced significantly their effects in some animal models. However, its efficacy in the treatment of diarrhoeic piglets appeared to be adversely affected by the presence of milk in the alimentary tract.
The effect of activated attapulgite upon endotoxins (lipopolysaccharides) of enterobacterial pathogens (enteropathogenic Escherichia coli and Shigella sonnei) was studied by means of the enterobacterial hemolysis and hemolysis inhibition tests and in vivo experiments in mice. It was found that activated attapulgite adsorbs the endotoxins as demonstrated by inhibition of enterobacterial hemolysis, elimination of the specific inhibitory effect of the antigens in hemolysis inhibition tests, and by die abolishment of toxicity in mice. The significance of the findings is discussed with particular reference to their bearing upon the clinical use of activated attapulgite in localized intestinal infections and other syndromes associated with these endotoxins.
An in vitro study was made of the adsorptive capacity of Claysorb for several representative human enteroviruses: poliovirus, types 1, 2, and 3; ECHO-9, and Coxsackie B-3. Within wide limits of virus concentration, temperature, pH, and duration of exposure, no specificity was evident in attaining a saturation adsorption level with a given clay concentration. Claysorb was superior to kaolin in comparison adsorption trials with these agents. These findings suggest a potential use for Claysorb in localized intestinal infections and other syndromes associated with enteroviruses.
Serum applied as a streak to a strip of filter-paper can be separated into six main bands, depending upon respective molecular weights (electrophoresis). When such bands of protein are exposed to a polyvalent anti-human serum diffusing in at right angles, at least 18 protein components can be identified as precipitation arcs (immunoelectrophoresis).Using immunoelectrophoresis, 202 sera taken at intervals from 86 patients with tuberculosis were compared with 160 sera from healthy persons and patients with non-tuberculous disease. With clinical recovery from tuberculosis, shrinkage of the beta-2 macroglobulin band was observed, and a gamma-1 globulin arc appeared or was accentuated. This finding suggests an early antibody response of large molecules, and a later defence by slowly developing small molecules, as seen in many common infections. The macroglobulins involved were found to be selectively adsorbed on attapulgite clay particles. This technique should be useful in developing serological tests for active tuberculosis.The apparatus used was designed and built by the authors at trivial cost. Its construction and operation are described.
The adsorption by attapulgite (a naturally occurring clay) of wild rabies virus in naturally rabid dogs was investigated. Attapulgite selectively absorbed rabies virus in the brain tissue of naturally rabid dogs and rejected rabies virus in extracts from the submaxillary salivary glands of the rabid dogs. Attapulgite rejected the neurotropic-adapted viruses lymphocytic choriomeningitis, Eastern equine and Western equine encephalitis, Japanese B encephalitis, and St. Louis encephalitis in the brain tissue of suckling mice.
Nine different absorption agents have been tested for their capacity to remove in vitro the toxic chemicals elaborated by
cultures of Shigella dysenteriae, Eberthella typhosa and Escherichia coli. The significance of the findings relative to clinical
application of adsorption agents is discussed.
Both thymocytes and splenocytes from B6 (H-2b) mice injected as neonates with C3H(H-2k) or (B6 X C3H)F1 cells exhibited specific nonresponsiveness to the H-2KD alloantigens in question. Thus, tolerance could be induced in strain combinations which did not share H-2 antigens. Induction of specific allotolerance did not require the presence of Thy-1.2+, Ia+ or G10-Sepharose-adherent cells in the donor inoculum, however injection of irradiated (1200 rad) cells was ineffective. Evidence of specific unresponsiveness was found as early as 5 days after birth and was not abrogated by adding either irradiated normal spleen cells or exogenous interleukin-2 in vitro. In fact, in some experiments there was evidence for the presence of stimulated helper T cells within the population of 'tolerant' cytotoxic T cells exposed to alloantigen. However, this could reflect the operation of a syngeneic mixed lymphocyte reaction directed at, for instance, fetal calf serum components expressed in the context of the tolerated Ia determinants.
A method for the quantitative determination of the adsorption of bacteria by clays has been described. Studies on the adsorption of four bacteria (all known causative agents in enteric infections) by activated attapulgite, halloysite, and kaolin have been carried out. The four bacteria were Staphyhcoccus aureus, Proteus vulgar is, Salmonella enteritides, and Sbigella paradysenteriae. Activated attapulgite was found to be superior to kaolin and halloysite as adsorbents for Staphyhcoccus aureus. None of the clays was found to be good adsorbents for the other bacteria. The results indicate that activated attapulgite warrants further investigation as an ingredient in intestinal adsorbent preparations.
Ion Exchange and Adsorption Agents in Medicine
- G. H. Martin
Rev. med. Suisse romande
- Kühne
J. Infectious Diseases
- Braafiadt
Am. J. Digest Diseases
- Greene
Münch, med. Wochschr
- Stumpf
Bull. acad. med., Paris
- Hayem
Am. J. Digest Diseases
- Swayne