The ability of the mouse neuroblastoma cell line NTR to proliferate at 40 degrees C correlates with the position of the temperature optimum of protein kinases A and C activities in the region of higher temperatures compared to those for cells of the original line N18AI, and with higher thermostability of protein kinase A after its heating at various elevated temperatures. The found changes in protein kinases A and C in the cells of NTR line mean that the selection of variants, capable of growing at elevated temperatures, is accompanied with conformational protein changes.

It has been found that irradiation in doses 0.5-2.0 Gy does not enhance the frequency of sister chromatid exchanges in cells of patients with Down's syndrome and ataxia-telangiectasia compared to the normal cells. In the case of ataxia, this phenomenon was accompanied with radioresistant replicative DNA synthesis, whereas in two cases of Down's syndrome the replicative DNA synthesis was found to be as radiosensitive as in the norm. According to these data, the mechanism of sister chromatid exchanges proposed in our previous publication (Pleskach et al., 1988) seems to be rather doubtful.

Karyological analysis of 6 cell lines with distinct tumorigenic properties of mouse strains C3H/He and CBA/Ca has been carried out using differential chromosome staining. All the cell lines are characterized by a decreased number of copies of normal chromosome 7, the increased number of normal copies of chromosome 10 being specific of the cell lines with intermediate tumorigenicity. Cell lines with maximum tumorigenicity differed from all other lines by the increased number of copies of chromosome 5 and by the decreased number of copies of chromosome 6. A wide independent variability was observed in the number of chromosomes and of several types of abnormal chromosomes throughout the neoplastic evolution of cells, to begin from the early immortal passages. But the proportion of normal chromosomes per cell in the studied lines revealed relatively stable values. The potential phenotypical heterogenicity of the lines with maximum tumorigenicity, expressed in their clonal progeny, was associated with the instability in the number of chromosome 15 copies in cells of these lines. It is concluded that multiple genetic events are required in the spontaneous neoplastic evolution of fibroblasts, and only specific traits of the karyotypic instability, associated with the variability of the number of copies of specific chromosomes, may constitute the genetic basis for the above process.

Morphological, electron microscopic, histospectrophotometric and morphometric (mean nuclear surface and ellipticity coefficient) studies of small cortical adenomas were performed. Surgical (kidneys removed because of renal cell carcinoma and shrinkage) and autopsy (atrophic kidney) materials were used. Total 142 adenomas were found in 93 out of 592 observations. The incidence of adenomas in kidneys with renal cell carcinoma was 12%, in contracted kidneys 19.2 and 19.44% (surgical and autopsy material). Electron microscopic examination was performed in 15 adenoma cases. Comparative quantitative DNA determination was performed in sections stained by Feulgen using plug-method on the microscope spectrum analyzers in 20 cases of adenoma and 15 cases of renal cell carcinoma identical histologically to adenocarcinoma. This combined study revealed the adenomas heterogeneity. Only part of them (well differentiated with diploid DNA-histograms and nuclei up to 32 mm2 may be referred to adenomas. All the others morphologically and morphometrically are close to adenocarcinomas. The type of DNA distribution and mean nuclear surface are most important for differential diagnosis between renal adenoma and carcinoma.

Immunoblotting and immunochemistry were used to study the expression of a c-src gene-encoded protein in human lung tumors. The authors were the first to identify this otherwise rarely expressed protooncogene in as many as 60% of lung malignancies of various histogenesis. The expression of c-src protein was increased not only in neuroendocrine tumors (small-cell cancer and atypical carcinoid) but also in non-small-cell tumors such as adenocarcinoma, bronchoalveolar and squamous-cell lung cancer. A weak correlation between protein expression and degree of cell differentiation was established for squamous-cell tumors. The study failed to identify the oncoprotein in the normal tissue and benign lesions. Immunoblotting using Mab 327 monoclonal antibodies and the immunohistochemical method employing TBR polyclonal serum yielded similar data. To summarize, an increased expression of pp60c-src was observed in lung cancer of various histology.

Morphogenetic and molecular-biological features of the lung peripheral tumours (small-cell carcinoma, atypical and typical carcinoid) were studied on the surgical material from 68 patients. Spectrum of histologic, histochemical, immunohistochemical (immunohistochemistry of oncoproteins c-fos, c-myc, c-ras, c-sis and c-src) methods, DNA histospectrophotometry by plug-method, electron microscopy, semithin section morphometry, statistical and correlation analysis were used. Small-cell carcinoma is shown to be a heterogeneous group of tumours that includes tumours with endocrine cell differentiation, endocrine and epidermoid and/or glandular, undifferentiated cell carcinoma. Lymphocyte-like carcinoma and intermediate cell carcinoma with endocrine cell differentiation are distinguished from other types of lung carcinoma by their low, sometimes diploid DNA content that does not correlate with its malignancy as well as by a low level of expression of cell oncogenes c-fos, c-ras, c-sis. Small-cell carcinoma with endocrine cell differentiation, atypical and typical lung carcinoids represent a unique histogenetic group of endocrine lung tumours that differ from each other by the degree of anaplasia.

Two cases of associated Recklinghausen's disease and different forms of schizophrenia (sluggish psychopathlike and shift-like paranoid) are described. Of special interest was the fact that such association was observed in two brothers. Based on the clinical material suggested, the conclusion was made about the modifying influence of the organism process in Recklinghausen's disease (brain gliosis) on the schizophrenic process, thereby creating certain difficulties in the diagnosis. It is also assumed that the age of the onset of Recklinghausen's disease may determine the clinical picture of the mental pathology.

A study was made of the prevalence and clinical pleomorphism of neuromuscular diseases in the Krasnodar territory. The incidence of the diseases is 15.7 per 100,000 population (738 patients). Primary progressive myodystrophies are most prevalent (6.9 per 100,000 population). The humeroscapular and facial form (1.36 per 100,000 population) and Duchenne's form (1.15 per 100,000 population) occur less frequently. The remaining forms are an extreme rarity. Secondary amyotrophies occur more seldom (23.2%). Of these, there prevail Charcot-Marie amyotrophy (2.69 per 100,000 population). The myasthenia incidence constitutes 3.05 per 100,000 population. The myotonic syndromes were encountered in 12.3%. Of these, Thomsen's myotonia occurred most frequently (1.55 per 100,000 population).

The structure of 12 spontaneous hepatoblastomas found in old (average age 26.5 months) male mice is described. There were considerable strain differences in their incidence: 0.5% (1/194), 0.5% (1/194) and 5% (10/198) in strain C57B1, CBA and F1 (CBA X C57B1), respectively. This proves the importance of genetic factor the role of which in the development of human hepatoblastoma is not established so far. Mouse hepatoblastoma develops almost invariably within or adjacent to liver cell tumours (adenoma or carcinoma). There was a correlation between the incidence of liver cell tumours within a given strain treated with different doses of carcinogen but such correlation was absent in mice of different strains. Histologically and ultrastructurally, mouse hepatoblastoma corresponds to the anaplastic variant of human hepatoblastoma. As distinct from human tumour, mouse hepatoblastoma does not contain alpha-fetoprotein. One tumour was transplanted to the syngeneic host and passed 30 transplant generations retaining the structure of a primary tumour with areas of osteoid tissue and foci of squamous cell metaplasia. Mouse hepatoblastoma may be induced by carcinogens. Likewise, according to the literature, risk of hepatoblastoma is higher in children whose mothers were exposed to the potential carcinogens before or during the pregnancy.

Morphologic and cytophotometric characteristics of tumours and tumour-like lesions of the stomach, colon and rectum from 267 patients were compared in the biopsy material. There was a diploid DNA distribution in the adenomas and tumour-like lesions of colon and rectum. The correlation between the proliferative activity and the epithelial dysplasia degree was noted in adenomas; aneuploid cells were found in 5 adenomas. 53% of gastric carcinoma and 64% of colon and rectum carcinomas were aneuploid (the difference is not significant). Poorly differentiated adenocarcinoma much more frequently (the difference is significant) was found in the aneuploid tumours, well differentiated adenocarcinoma and signet cell carcinoma- in the diploid tumours. DNA index (1.09-1.50) of the aneuploid cells of gastric carcinoma was in 42% cases in the near diploid--triploid region while in colon and rectum carcinoma (60.5%) it was in the triploid--tetraploid region. The type of DNA distribution, particularly in the diploid tumours, should be controlled cytologically.

Polymorphism of the human c-Ha-ras-1 gene has been analysed in 66 BamHI restricted DNAs from blood of 35 patients with "inherited" breast cancer, 7 fibroadenoma patients, 13 healthy first-degree relatives and 11 unaffected controls. Two "common" and four "unusual" alleles were detected. The frequency of "common" (6.6 and 7.4 kb) and "unusual" (6.9 kb) alleles was identical to that in the control and unaffected groups (65.8, 17.1 and 7.1%). Rare alleles (7.6 and 7.8 kb) were only detected in breast cancer patients and in healthy first-degree relatives. A 8.0 kb allele specific for control patients was also detected. No absolute relationship between the genetic predisposition to breast cancer and the Ha-ras genotype was assumed.

It has been established that acute lymphoblastic leukemia cells showing identical immunological phenotype have similar morphometric values and electrophoretic mobility that significantly distinguish them from lymphoblasts of other subvariants. These results have evidenced the expedience of using these criteria for correct identification of leukemic cells. Besides that, similarity of phenotypic features of leukemic cells of a particular line, having identical differentiation status, has supported the opinion on their lineal affiliation.

Analysis of home and foreign literature underlies the discussion of the significance of cytogenetic variations (frequency of aberrant cells and SCE-heteromorphism of C-chromatin and brittleness of chromosomes as indices of chromosome instability in oncological patients.