X-ray fluorescence analysis using synchrotron radiation (SRXRF), X-ray powder diffraction, and vibrational spectroscopy had been applied for determination of elemental and mineral composition of human salivary stones. By the X-ray powder diffraction analysis, the main constituents of salivary stones were found to be apatite and apatite plus whitlockite. The SRXRF method showed that Ca and P were the major elements, while other microelements such as Fe, Cu, Zn, Se, Br, Sr, Pb were also detected. The Ca/P molar ratio ranged from 1.39 to 2.35. These results were in agreement with the X-ray diffraction and vibrational spectroscopy data.

[Odontogenic total mediastinitis complicated by an arrosive hemorrhage from the major vessels of the neck]

Some recent results on testing the special double one-coordinate X-ray detector for digital subtraction angiography on synchrotron radiation from the VEPP-3 storage ring are presented. The obtained spatial resolution of the detector is in the range of 0.1–2.0 mm, which gives the possibility to investigate the lymphatic nodes of animals after injection of an iodine containing contrast agent. In preliminary experiments the mediastinum lymphatic nodes of rats that were alive were visualized at low iodine concentration.

BACKGROUND:Tracer studies are an important tool to obtain information about the processes involved in the immunological response. Colloidal gold is widely used as a tracer, but its small size of label can cause some difficulty during low-resolution analysis. To overcome this difficulty, we developed a new method to follow the route of tracer movement within lymph nodes.METHODS:We applied conventional X-ray analysis, X-ray fluorescence analysis (XFA) subtractional microscopy using synchrotron radiation (SR) beams, light microscopy, and ultrastructural analysis to study the distribution and quantity of colloidal gold coupled with albumin within rat parasternal lymph node 2, 4, 6, 8, and 10 h after intrapleural injection of the tracer.RESULTS:At all the time points XFA-SR revealed that tracer formed a circle with a maximum concentration in the node periphery. XFA-SR measured colloidal gold concentration in the nodes reached its maximum (0.5-0.75 weight %) in 6-8 h. Subtractional microscopy revealed superficially located groups of cells filled with colloidal gold tracer. Light microscopy and ultrastructural analysis confirmed that the tracer was concentrated in the reticular cells, situated in the sinuses of the node. Sinusoidal reticular cells concentrated tracer at much higher rates than sinusoidal macrophages. Four hours after injection, gold appeared in the lysosomes of the follicular reticular cells. At the same time point, evidence of antigen presentation was obtained. Antigen presentation proved to be an extremely rara event since only one ultrastructural incident was found in 150 analysed grids.CONCLUSIONS:SR is a valuable tool for the analysis of gold tracer passage within the living organism.

This work is devoted to the application of the liposomic forms of X-ray contrast agents which contain iodine to contrast mediastinal lymph nodes of laboratory animals. A highly-sensitive SRXFA helps to observe the transfer of small amounts of X-ray contrast agents to organs-targets — the mediastinal lymph nodes.

The possibilities of SR usage in experimental medicine are considered. X-ray contrast agents which contain gold, silver, iron, platinum and rhodium were used to examine mediastinal lymph nodes of laboratory animals. The possibilities of X-ray contrast substance transport and the nature of their distribution in the internal structures of the lymph nodes were studied as well.

The results are presented of the examination of normal and pathological human lymph nodes. The results have been derived by X-ray scanning difference microscopy and microtomography using synchrotron radiation from the storage ring VEPP-4 (Novosibirsk) and have been supplemented by the information gained from direct radiography using an X-ray tube as well as from the examination of the morphological structure of lymph nodes. The results of different methods are compared. The advantages of X-ray difference microscopy for research of the mechanism of functioning of the lymph nodes are indicated.