[The induction of cancer of the large intestine in Macaca fascicularis monkeys with 1,2-dimethylhydrazine].

Continuous subcutaneous administration of 16 mg/kg body weight 1,2-dimethylhydrazine three times a month (total dose--1080-3696 mg) to Macaca fascicularis monkeys induced cancer invariably confined to the colon within 34-47 weeks. Biologic, clinical, histologic features and natural course of the tumor proved similar to those of its human counterpart.

[Electrophoretic mobility of the cells of non-T, non-B acute lymphoblastic leukemia].

In order to ascertain the possibility of the use of electrophoretic mobility (EPM) as one of the criterion for delicate identification of the leukemic cell, a study was made of the EPM of blast cells having an approximately equal status of differentiation. A study was also made of lymphoblasts of the most frequently occurring variant of acute lymphoblastic leukemia, namely of the non-T, non-B variant. It has been established that the given cells are marked by the similar values of the EPM, which greatly exceed the analogous characteristics of normal mature B lymphocytes, being lower as compared with the EPM of T lymphocytes.

[Dependence of the antitumor activity of nitroso alkyl urea derivatives on their chemical structure].

The antitumour activity of 10 analogs of nitroso alkyl urea was studied on 6 tumour strains. It was shown that antitumour effect depends upon the gentle structural changes of substances (changes of side chain, the position of aromatic nucleus in it, as well as the nature, quantity and position of substitutes in the nucleus). 7 compounds out of 10 analogs of nitroso alkyl urea have manifested antitumour activity.

Induction of gastric cancer in monkeys by N-methyl-N-nitro-N-nitrosoguanidine (MNNG).

N-methyl-N-nitro-N-nitrosoguanidine (MNNG) was administered to 9 Macaca fascicularis monkeys (7 males and 2 females) through a tube at a dose of 40 mg/kg body weight 3 times a month. Tumors of the pyloric part of the stomach were observed in 2 male monkeys after MNNG doses of 800 and 848 mg/kg body weight, with a latent period of tumor development of 49 and 50 weeks, respectively. Histologically, in one case the tumor was a solid carcinoma, and in the other it had a mixed structure showing alternating solid and signet ring cell carcinoma areas.

[The induction of stomach cancer in monkeys with N-methyl-N'-nitro-N-nitrosoguanidine].

Gastric tumors were detected in 2 out of 9 apes following MNNG treatment with a total dose of 800-848 mg/kg (40 mg/kg, thrice a month, 49-50 weeks, via gastric probe). The characteristics, course, symptoms and histologic patterns of the tumors proved comparable with similar neoplasms in humans.

[Ultrastructural characteristics of immunologic subvariants of acute T-cell lymphoblastic leukemia].

Ultrastructural comparison was conducted between different immunological subvariants of T-cell acute lymphoblastic leukemia (T-ALL). Using the panel of monoclonal antibodies the cases of T-ALL were categorized into the following subvariants (early-T-, mature-T- and mature, activated-T-cell ALL). It has been shown that cells of these subvariants differ from each other in their ultrastructure and at the same time they reflect the submicroscopic features of corresponding normal counterparts.

[The current criteria of cell identification in acute lymphoblastic leukemia].

The categorization of subvariants of acute lymphoblastic leukemia (ALL) is made on the basis of the data from literature on the study of immunological phenotype, gene rearrangements, chromosomal abnormalities and oncogene expression in neoplastic lymphoid cells. It is supposed, that such combined approach to categorization of ALL will promote further development of precise identification of leukemic cells and, consequently, the elaboration of optimal regimen of the therapy.

[Decreased isoproterenol sensitivity of the salivary epithelium in mice with transplanted tumors].

The proliferative response of secretory cells of parotid glands to isoproterenol could not be observed in tumour-bearing mice, while in normal mice a ten-fold increase was usually observed. Mice with subcutaneous allografts of normal tissue (tail fragments) demonstrated sensitivity similar to normal mice. Apparently, a lack of sensitivity in tumour-bearing mice is characteristic of the tumour-host interaction.

[Ultrastructural characteristics of the histological forms of breast tumors].

Differences in ultrastructurally-differentiated and undifferentiated cells distribution were established in such non-invasive and invasive histological patterns of breast cancer as medullar carcinoma, mucinous, adenoid-cystic and lobular invasive cancer by means of electron microscopy. It was shown that a certain histological pattern is not necessarily matched by a relevant degree of ultrastructural differentiation of tumor cells. Tumor tissues of a similar histological pattern sometimes revealed different ratios of ultrastructurally-differentiated and undifferentiated cells, which may be responsible for the peculiarities in the clinical behavior of the said neoplasms.

[Ultrastructural tissue-specific signs of the cells of cancerous tumors of the human breast].

Ultrastructural analysis of mammary carcinoma (45 cases) and its metastasis in the lymph nodes (21 cases) revealed the tissue specific features of the mammary gland: big ducts and intercellular canaliculi, microvilli, various specialized cell-to-cell contacts, basal membrane. Tissue specific features are not associated with a certain organ. In mammary carcinoma, they are more pronounced in carcinomas in situ, invasive tumours of the 1st grade of malignancy (adenocarcinoma) and specific histologic variants.

[Interpretation of the results of various histochemical reactions used in pathological anatomy].

Some approaches to correct interpretation of indices of histochemical reactions most often used in pathologo-anatomic investigations are analysed on the basis of the author's personal observations and literature data. It is shown that direct interpretation of results of histochemical reactions according to the conventional scheme (negative reaction--the absence of the substrate in question, low-positive reaction--a low content, and highly positive reaction--a high content) is not always justifiable. One and the same histochemical phenomenon may have different meanings and reflect various functional states of the structure under study.