However, they assumed that similar processes take place under the influence of microbes in living tissues, for example, in the heart. Likewise renal and intrahepatic calculi, heart calculi consist of mineral casings, by which bacteria colonies get covered, the bacteria often residing in the endocardium and on the mitral valves’ surface, but making their presence known only occasionally via infectious inflammation - endocarditis.
Bacteria live in the blood and precipitate apatite from it. Cardiolytes are formed - coral-like calculi weighting from 1 to 4 grams penetrated by organic films. They have to be surgically extracted out of the heart. Cardiolytes’ microstructure gave away their bacterial origin – they consist of the smallest corpuscles - globules, their size being less than one thousandth portion of a millimeter, and such constructions are normally built by bacteria. Globules inosculate, thus forming clusters, spheres or drusen in the shape of a flower.
A little later, the researchers managed to catch the builders. They turned out to be bacteria of the coccoid (spheric) shape connected by polysacharide threads. The researchers do not exclude the possibility that these are the very enterococci and streptococci, which cause infective endocarditis. At least, a lot of patients who had survived it, needed to remove calculi from the heart later, as physicians rarely manage to fully extirpate parasites. Endocarditis is over, but the survived microbes recover from antibiotics and go on living.
The researchers examined via the electron microscope how cardiolytes are formed. The cardiolytes were withdrawn during the heart operation in several clinics of Siberia. Natural samples were brought for comparison from the European part of Russia, Morocco and Columbia. The researchers produced a series of preparations from different sections of “calculi” - 2 by 2 millimeters. It has turned out that both natural apatites of organic origin and cardiolytes consist of similar globular formations. The globular structure is in general the indication of biogenic origin of minerals – for example, natural carbonates are arranged in the same way. In cardiolytes, globules, corresponding in shape to the organisms that constructed them, are sorted out by size – small ones are placed along the edges of the colony, while big ones are in the middle. This indicated to gradual drusen “maturing” in the environment saturated by organic matter that contained phosphorus and calcium.
Natural and “human” apatites differ in their chemical composition. The former are better crystallized, they contain less organic matter. It is not surprising because stones are million years old, and calculi are several years old. The source of calcium and phosphorus for “stone mason” bacteria are organophosphorus molecules, which are numerous both in blood and in natural water. Their cells artificially concentrate phosphorus and calcium around them, and there is no big difference from geochemistry perspective between the cardiac muscle and the bottom layer of water saturated with organic matter. Thus, the apatite in the cardiac muscle represents the initial stage of the process, and natural minerals constitute the final product.
Ability for biomineralization within the organism is closely connected with blood composition. Several years ago, biologists managed to reproduce microbe biofouling by phosphorite casings in the in vitro culture. Thus, for example, cyanobacteria are capable to get covered by the mineral within several hours. Having made sure that various “calculi” in the organism are built by bacteria, the search can be started as regards to means of impeding this construction.
Nadezda Markina | alfa
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