[Mesothelium and malignant mesothelioma of the pericardium].

Malignant mesothelioma of the pericardium is characterized by atypical solid growth of mesothelium with formation of atypical cavities, slits surrounded by a fibrous stroma. Unless early biopsy, diagnosis and surgery, the prognosis is unfavourable. It is desirable to create immunomorphological test for mesothelium.

[Blastomogenic action of combined total external and local internal (131I) irradiation on adult rats].

In the combined irradiation (the total dose of the thyroid uptake--15000 rad) the total incidence of tumors was close to that in isolated X-irradiation, but their multiplicity was much higher. The incidence of thyroid tumors (16.6%) was close to that in iodine-131 administration (17.

[Granulomatous lesions in the lungs of experimental animals].

Granulomatous lesions of the lungs and regional bronchopulmonary lymph nodes in laboratory animals which developed spontaneously but were of epidemic nature are described. Stages of the development of pulmonary lymphoepithelioid granulomas and giant cells, the appearance of caseose-like necrosis, and the development of sclerosis of the nodules are observed. The features of sclerosing of the nodules, localization of histiocytes, macrophages, and collagen fibers are similar to those in a silicotic process in the lungs developing upon administration of Si.

[Morphogenesis of emphysema in occupational lung diseases (clinico-anatomical comparisons)].

The distinction of pneumoconiosis and occupational (dust) bronchites in the clinic of occupational lung pathology required morphological justification of such divisions. Examinations of 37 fatal cases with dust pathology of the lungs showed that in two thirds of the cases predominantly obstructive bronchitis forms of emphysema and compensatory perinodular forms of emphysema in silicosis could be diagnosed morphologically. A less marked diffuse character of emphysema in focal forms of pneumoconiosis is conducive to the inclusion of compensatory mechanisms preventing the development of pneumonial and cardial insufficiency.

[Alveolar microlithiasis].

A total of three observations on alveolar microlithiasis are described: two in female patients aged 19 and 44, and one in a man aged 56 years. In two patients diagnosis was established following biopsy of the lung tissue, and in one--posthumously. Basing on the literature data, the authors discuss problems of pathogenesis, clinico-morphological manifestations and differential diagnosis of the disease.

[Pathological anatomy, etiology and pathogenesis of remote sequelae of radiation dust exposure].

Thorium (Th) is one of the widely spread radioactive substances in nature, and together with other aerosols it can penetrate into the organism. The article considers relationships between various histological forms of neoplasms induced by a radioactive dust agent containing Th and the power of this etiological factor (total body dose and its power). In experiments with 3000 white rats a 150 rad dose accumulated in the lungs during 15--21 months led to an increase in the number of cases of reticulosarcoma, a 300 rad dose produced no such effects.