[Ossifying fibromyxoid tumor].

Ossifying fibromyxoid tumor (OFMT) is a rare tumor of unknown histogenesis. It consists of chains and trabecules of ovoid cells in the fibromyxoid stroma (ICD code 8842/0). Tumor is frequently surrounded in part by a capsule of laminar bone. It is more frequent in males 14-79 years of age, mean 44 years. Soft tissues of extremities is a preferable location, but body, neck, oral cavity, mediastinum and retroperitoneal tissue can also be the site of OFMT. More than 100 OFMT cases are reported abroad. It is frequently masked by other tumors of soft tissues. We describe 3 cases in our country: 2 in 65 and 66 year old females and in a 44 year old male. Lipoma and soft tissue sarcoma were suspected clinically. Fibroblasts were found cytologically before operation in one case. Diagnosis was established after total biopsy of the tumor. One of the females is under observation after the operation without recurrence during more than two years. Preoperative diagnosis is sometimes possible when characteristic osteoblastic foci are observed.

Structural and functional properties of Langmuir films of antibodies based on amphiphilic polyelectrolytes.

We optimized the procedure for the formation of Langmuir films of antibodies based on amphiphilic polyelectrolytes and studied the physicochemical and immunochemical properties of the films obtained. Their immunochemical properties were compared with the immunochemical activity of antibodies in Langmuir films without amphiphilic polyelectrolytes and with antibodies adsorbed on the surface of polystyrene and graphite. The efficiency of immune adsorption by the films based on amphiphilic polyelectrolytes was shown to be greater; the affinity of antibodies and surface concentration of their active conformation depended on the type of amphiphilic polyelectrolytes used to obtain the films. We investigated the structure of these films at the surface of highly oriented pyrolytic graphite using the method of atomic force microscopy. Changes in the structure of the films under study caused by the increase of surface pressure were demonstrated.

[The use of atomic-force microscopy for the analysis of microbiological objects]. / Ispol'zovanie atomno-silovoi mikroskopii dlia analiza mikrobiologicheskikh ob''ektov.

Atomic force microscopy (AFM) was used for the analysis of rickettsiae and viruses. The specificity of interaction was evaluated on the basis of the adsorption of the analyzed antigen on the polymer-antibody film. The film was formed and transferred onto highly oriented pyrolytic graphite (HOPG) by the method of Langmuir-Schaefer with the use of amphiphilic polymers, alkylated polyethyleneimines. According to the data of AFM, polymer-antibody film was 10-30 nm thick and had ruptures, uneven surface. AFM images of Coxiella burnetii, rotavirus and Venezuelan equine encephalitis virus, immunoadsorbed on the antibody film, were obtained. C.burnetii, due to their size equal to (700-900) x (300-500) x Z = 200 nm, were clearly visible on the underlying surface and could be directly counted. Individual virus particles (60-80 nm) cold not be identified on such surface. To analyze such preparations, the program of image analysis was developed. The program classified the registered image with a certain standard. This program determined the presence of virus antigen on the underlying affinity surface with a high degree of precision.