Poly(2-hydroxyethyl methacrylate) microspheres/liquid poly(dimethylsiloxane) composition for correction of small defects in face: histological evaluation in animal experiment.

Two kinds of composition based on commercial liquid poly(dimethylsiloxane) and laboratory-made poly(2-hydroxyethyl methacrylate) (PHEMA) microspheres of different size fractions (30-40 or 125-180 microm) were prepared. Tissue reaction on injection of the compositions, optimum microsphere size and morphology were investigated in the experiments on rats. The microspheres induced foreign body reaction characterized by an increased content of fibroblasts and mild infiltration of injection field by inflammatory cells.

[Classification of pancreatic exocrine tumours].

Current international histologic classification of exocrine pancreatic tumours is presented. Macro- and microscopic characteristics of benign and malignant tumors are described. The role of immunohistochemistry in differential diagnosis is shown.

[Adult hepatoblastoma].

A rare case of hepatoblastoma is reported in a female of 47 years of age with literature review of these tumors in the adults. Microscopically the tumor was represented by the cells of embryonal and fetal types. Immunohistochemically expression of low-molecular cytokeratins as well as that of S-100 protein and hepatocyte antigen was observed.

Autoradiographic study of parasympathetic paragangliomas (chemodectomas) of the neck.

Study of the morphofunctional characteristics of chemodectomas of the neck by photoautoradiography (semithin sections) showed the absence of protein-producing and proliferative activity in light and dark tumor cells against the background of strained biosynthetic processes in stromal cells. Invasion of capillary walls by tumor cells with their release into the capillary lumen is a prerequisite for metastases of these tumors.

[Electron-radioautographic study of parasympathetic paragangliomas (chemodectomas) of the neck].

Chemodectomas, after the surgery, were studied in 7 patients. Morphologically their malignancy is proven on the basis of pronounced cell polymorphism, atypia, invasion of tumour cells through the vessel wall into their lumen. Besides rare mitoses, proliferative (DNA synthesis) and protein synthetic (RNA synthesis) activity in clear and dark cells was not observed in the presence of intensive biosynthetic processes in the stroma cells.