Subject to examination were 80 patients with gastric carcinoma and 80 control patients admitted to the same medical institutions but with no malignant diseases. The groups were compared by sex, age and residence. Different levels of exposure to hypothetic factors were assessed by means of standard tests employed in the examination of matched pairs. It has been established that such habits as tobacco-smoking, consumption of alcoholic drinks and coffee in large amounts as well as the presence of malignant diseases in the familial anamnesis increase the risk of affliction with gastric carcinoma.

DNA level measured by flow cytometry and estrogen and progesterone receptors assayed in tissue samples obtained from 85 malignant and 16 benign lesions of the breast. All the benign tumors revealed 2c DNA content and most of them were receptor-negative, while 74.1% of breast carcinomas displayed aneuploidy. Three patients (3.5%) had two lines of aneuploid cells. Many aneuploid tumors were receptor-negative. Preoperative radiation treatment (14-20 Gy) did not significantly influence the level of steroid hormone receptors in tumors. Estrogen receptor level was higher in menopausal patients than in premenopausal ones.

Medico-genetic examinations of 122 patients with multiple and/or early-onset basalioma revealed 5 cases of basal cell nevus syndrome. Clinical data on 5 probands and 3 first-degree relatives with the syndrome are presented.

Ha-ras restriction fragments' length polymorphism (RFLP) in white blood cells and stomach tissues from patients with carcinoma and ulcer of the stomach was examined. Genomic DNAs were digested with Xho I, Pvu II, Pst I, Msp I, Bcn I, Mva I, Bsp RI. No Ha-ras-1 polymorphic variants specifically associated with the cancer disease were detected. RFLP of the 3'-noncoding sequence of c-Ha-ras-1 gene had got features of the definite human population. The cells forming the tissue were examined and individual peculiarity of the methylated residues disposition seemed to influence RFLP of the 5'-noncoding sequence of c-Ha-ras-1.

A complex (population, clinico-familial, cytogenetic and biochemical) investigation was performed in 50 cases of thyroid medullary cancer and their relatives. The study evaluated the diagnostic value of tests used to identify hereditary forms of the disease which accounted for one-third of the cases. Guidelines for identification of groups at high risk for thyroid medullary carcinoma are discussed.

The receptor status of the tumors examined in 74 patients with breast cancer was found to correlate with its ploidy and proliferative activity as evidenced by flow cytometry and it failed to correlate with a histological tumor type and metastatic involvement of regional lymph nodes. In terms of DNA content, the receptor-positive tumors were more frequently diploid, the receptor-negative ones were aneuploid. The proliferation index (PI) for the receptor-negative tumors was significantly higher than that for the receptor-positive ones. The diploid tumors showed lower proliferative activity than the aneuploid ones. Among the aneuploid tumors, PI for infiltrative lobular cancer was significantly lower than that for infiltrative duct cancer. Early in invasion, duct carcinoma was predominantly diploid, of grade I-IIA malignancy and more infrequently metastasized into regional lymph nodes. Grade IIB-III malignant tumors were chiefly aneuploid and more frequently metastasized into regional lymph nodes.

Recent data on the role of human papillomaviruses in the arising and development of cervical neoplasia are reviewed. Cervical dysplasia is characterized, its natural history and the role of papillomaviruses in arising of dysplasia and cervical cancer are described. Modern results on identification of the capsid antigen and DNA of human papillomaviruses in different cervical lesions are presented. Several types of papillomaviruses with different oncogenic potential, as well as molecular aspects of the virus gene expression and cellular differentiation are discussed.

In the normal salivary gland, the monoclonal antibody to keratin 8 immuno-morphologically identifies the epithelium that covers acini and ducts. The monoclonal antibodies to keratin 17 and vimentin detect normal myoepithelium. The two keratins are found both in the epithelioid and mesenchyma-like components of pleomorphic adenoma, suggesting a single epithelial nature of this tumor. In all the morphological components of the pleomorphic adenoma, there are cells that combine protein expression of intermediate filaments normally labelling different cell subpopulations. This fact provides support for the hypothesis that the pleomorphic adenoma originates from bipotent precursor cells. A particular phenotype of pleomorphic adenoma elements is realized under the control of the local density of cells and microenvironment, as a result of which the cells expressing vimentin predominate in the mesenchymal component, keratin 8 in the epithelial tubular one.

Flow cytofluorometry has been used to examine the tumor ploidy in 32 patients with benign mammary tumors and 41 patients with mammary carcinomas; the relationship between the tumor ploidy and the disease prognosis has been under study. Chicken red cells whose DNA content is invariable and is almost 3 times lower were used as the inner reference sample for diploid cells. All the obtained DNA histograms of benign mammary tumors were diploid (the DNA index 1), those of malignant tumors aneuploid in 26 (63%) and diploid in 15 (37%) cases. Analysis of the late results of treatment has shown that the process progress is significantly more often in the patients with the aneuploid DNA content in the tumor cells (chi 2 = 10.2; p less than 0.01), this progress being due to delayed metastases to the lymph nodes, bones, and viscerae; the 5-year survival rate is lower (chi 2 = 4.19; p less than 0.05) than in diploid malignant tumors.

A study was made of the expression of the cellular oncogens c--myc, c--sis and c--abl in mononuclears from normal donors and patients with different patterns of leukemia and hemopoietic dysplasia using spot hybridization on nitrocellulose filters with virus homologs of the given oncogens. Altogether 43 persons were examined. No specific expression of the oncogens indicated was established whatever the pattern of leukemia. The relationship between the expression of these oncogens and the efficacy of the treatment of acute myeloblastic leukemia was demonstrated. However, in the given investigations, no differences were identified in the expression of oncogens in the leukemic and normal cells stimulated with PHA and phorbolic ether. Enhanced expression of cellular oncogens myc, sis and abl occurred in acute leukemia.

Employment of isoelectrofocussing techniques for the determination of proteinase alpha 1-inhibitor (p alpha 1i) phenotypes helped detect original rare phenotypes. Their accurate identification should be performed with a set of standard sera. The findings of studies on the number of p alpha 1i by Mancini's immunoprecipitation test are analyzed, as are the data of phenotype studies by p alpha 1i isoelectrofocussing in children suffering from acute leukemia and sepsis. The findings evidence a drastic increase of p alpha 1i number, parallelled by the emergence of a manifest anode fraction of a common Pi MM phenotype; this may be regarded as a manifestation of a rare Pi MM anode phenotype in phenotyping. The possible reasons of this phenomenon are discussed; the authors emphasize the significance of analyzing rare p alpha 1i phenotypical variants with standard sera.

Seven patients with various adrenal processes (1 cortical hyperplasia, 6 adenomas, 1 cortical carcinoma, 1 malignant pheochromocytoma) have been examined using ultrasonic technique, computer-aided tomography, hormonal tests, and flow cytometry. The findings have been correlated to the results of cytologic and histologic studies. One of the aims of the study was to find out whether DNA content was a factor permitting the diagnosis of the adrenal tumor nature. A diploid distribution of the DNAs with a varying content of proliferating cells has been found in benign tumors of the adrenals, whereas the malignant tumors have been aneuploid with varying ratios of the diploid to aneuploid tumor cells. Study of the DNA content by flow cytometry helps assess the cell ploidy distribution in the studied population and their proliferative activity, thus permitting a more accurate morphologic characterization of the tumor and, possibly, giving more reliable diagnostic criteria.

The dispersion of the Alu-family DNA repeats in phytohemagglutinin-stimulated lymphocytes from peripheral blood of normal donors as well as in nonstimulated bone marrow cells of four patients suffering from acute leukemia was studied by hybridization on metaphase chromosomes in situ. DNA of bacteriophage lambda CAR42 clone containing the insertion of at least 8 copies of Alu-family DNA-repeats and labelled with tritium was used as a probe in hybridization. All patients with acute leukemia had the same pattern of changes in hybridization of the bone marrow cells. It consists of silver grains clustering over 3q26, 8p12, 14q24. The pattern may reflect amplification transposition of Alu-family DNA repeats in the human genome connected with cellular differentiation or malignant transformation of blood cells.

In the cells of tumors induced with methylcholanthrene in wild type and mutant (pink-eyed dilution) Djungarian hamsters non-random involvement in structural changes of certain chromosomes (Xp, 3p and 3q, 7q, 8q) was revealed. In addition, characteristic feature of the majority of tumors was varied number of double-minutes chromosomes (DMs). In some tumors, the markers with long homogeneously or differentially stained regions (HSRs and DSRs) were also present. The DMs, HSRs and DSRs are known as the structures containing amplified genes.

The method of circular dichroism (CD) has been used to investigate the reconstitution of mononucleosomes from C3HA mice liver and ascitic hepatoma 22A cells chromatin. It has been revealed that the more unfolding state of DNA in ascitic nucleosomes (discovered earlier) is determined by the peculiarities of the interactions between DNA and the dimers H2A-H2B, as well as by the linker histones of the H1 group. The investigation of the DNA folding in the oligonucleosome chains with increasing ionic strength has shown complete invariability of the DNA compactness in the ascitic chromatin up to 100 mM NaCl, while in liver nucleosomes an additional folding of the linker portion of the DNA was observed within the range of 20-40 mM NaCl. Oligonucleosomes from ascitic chromatin are less inclined to association upon increasing ionic strength, as compared with those from liver chromatin.

The composition and structure of nucleosomic fragments isolated from the ascitic hepatoma 22A cells, liver and from cells of C3HA mice in norm and after partial hepatectomy were investigated. Via electrophoresis in 1.5% agarose gel with the emplogment of reperic restrictive DNA fragments and with the help of mathematical processing, the value of the nucleosomic DNA repeat in ascitic hepatoma 22A was calculated to be 187 b.p., and in regenerating liver--196 b.p. The absence of the H1 degree subfraction in chromatin of ascitic hepatoma 22A cells was found. Lower electrophoretic mobility in 5% polyacrylamid gel of nucleosomic chromatin fragments of ascitic hepatoma 22A as compared with their counterparts from healthy mice liver was established. The method of circular dichroism allowed to reveal differences in the RNA and protein structural state in nucleosomes of normal and tumour cells. The structure of nucleosomes of regenerating mice liver of the C3HA strain did not differ from that of normal liver of the same mice.

The multifactorial nature of breast cancer was established based on population and family study, the contribution of genetic factors being 52% (premenopausal--62 and postmenopausal--39%). Genetic heterogeneity of different coefficients of inheritance of breast cancer with the portion of common genes was shown to be 53%. The analysis of breast cancer interaction with other malignant neoplasms revealed that the development of other malignant neoplasms was the result of the influence of partially common genes. On the basis of data obtained in this study, the tables of repeated risk for the relatives have been worked out which may be used for medico-genetic consultations.