[The prophylactic administration of interleukin-2 increases the survival of mice with an acute intra-abdominal infection caused by Staphylococcus aureus]. / Profilakticheskoe vvedenie interleikina-2 uvelichivaet vyzhivaemost' myshei s ostroi vnutribriushnoi infektsiei, vyzvannoi Staphylococcus aureus.

The effect of RIL-2 on the survival of mice with acute Staphylococcus aureus strain 5/2 intra-abdominal [correction of intraperitoneal] infection was studied. RIL-2 was ineffective when administered simultaneously with the LD100 dose of bacteria. Antibiotics (gentamycin or combination of penicillin and streptomycin) administered in the same fashion cured 100% of animals. However, RIL-2 proved to be effective when administered simultaneously with LD70 dose of bacteria. The prophylactic course of RIL-2 consisting of repeated injections on days 3, 2 and 1 before the challenge with LD100 dose of bacteria also resulted in the marked increase of the survival of mice. The hypothetical mechanisms of action and the prospects of RIL-2 application are discussed.

[The effect of recombinant interleukin-2 on the course of experimental staphylococcal peritonitis in mice]. / Vliianie rekombinantnogo interleikina-2 na techenie éksperimental'nogo stafilokokkovogo peritonita u myshei.

The effect of RIL-2 on the survival of mice with S. aureus--induced peritonitis was studied. Animals received bacterial suspension and RIL-2 as following: bacteria--on days 0, +2, RIL-2--day 0 (group 1); bacteria--days 0, +4, RIL-2--days 0, +2 (group 2); bacteria--days 0, +6, RIL-2--days 0, +2, +4 (group 3). RIL-2 exerted no protective effect in group 1. However, in groups 2 and 3, where the control animals survival was, resp., 56% and 38%, the RIL-2 treatment increased survival up to, resp., 84% and 70%. Antibiotics given instead of RIL-2 in analogous regimen decreased the survival in group 3 to the level of 25%. Thus, RIL-2 proved to be a potent therapeutic agent in the 2nd of 3d studied models of S. aureus--induced peritonitis in mice. The perspectives of RIL-2 use in the treatment of bacterial peritonitis, including porous ones, and of the immunodepression--aggravated conditions are discussed.

[Mouse hepatoblastoma: comparative aspects]. / Gepatoblastoma myshei v sravnitel'nom aspekte.

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.

[Stimulating action of the vaccinia virus on the development of spontaneous and induced neoplasms in mice]. / Stimuliruiushchee deistvie virusa ospovaktsiny na razvitie spontannykh i indutsirovannykh novoobrazovanii u myshei.

Vaccinia virus was shown to exert a stimulating effect on the emergence of spontaneous neoplasia and Rauscher virus-induced hemoblastoses in BALB/cJLacSto mice. The mechanism of the stimulating effect is discussed.

[Genetic and oncologic characteristics of CBA/CaLacSto mice]. / Geneticheskaia i onkologicheskaia kharakteristika myshei kinii CBA/CaLacSto.

400 male and female CBA/CaLacSto mice were analyzed from the age of two months to their death. The spontaneous malignancy incidence of frequency in this line amounted to 76.3% with prevailing hepatomas (65%), neoplasms of lung, fat tissue. Homozygosity of CBA/CaLacSto mice was revealed in all the gene under test.

[Isolation of sarcoma virus from noninbred rats]. / Vydelenie virusa sarkomy ot besporodnykh krys.

The data are presented on the activation of endogenous retrovirus in vaccinia virus--malignant transformed cells of rat tissue culture. Infection of the cells by Mazurenko mouse leukemia virus induced rat sarcoma virus. The latter was formed as a result of recombination of sarcoma virus-specific sequences received from the rat cells malignantly transformed by vaccinia virus and virus-helper (Mazurenko mouse leukemia virus).

[Spontaneous hepatomas in hybrid mice (CBA x C57Bl/6)F1]. / Issledovanie spontannykh gepatom myshei-gibridov (CBA x C57Bl/6)F1.

The spontaneous hepatomas of male mice (CBA X C57B1/6)F1 were studied using complex cytologic, histologic, immunochemical, and cytochemical methods. The AFP was detected in trace amount in the serum of tumour-bearing mice and in single cells of hepatomas. As a rule the hepatocarcinoma cells have the polymodal DNA distribution (2C-8C) with major peak of 4 C (in 18 out of 26 cases). More rarely the tumours with predominant diploid and octoploid cells were observed.

[Genetic and oncological characteristics of CC57BR/Mv mice]. / Geneticheskaia i onkologicheskaia kharakteristika myshei linii CC57BR/Mv.

The incidence of spontaneous malignancies in this line was 21.3% with predominance of haemoblastoses, adenomas of the lungs and liver. The study of the genetic character revealed homozygosis of mice CC57BR in all test genes.

[Ploidy level and alpha-fetoprotein production in spontaneous murine hematomas in relation to the degree of histological differentiation]. / Uroven' ploidnosti i produktsiia al'fa-fetoproteina v spontannykh gepatomakh myshei v zavisimosti ot stepeni gistologicheskoi differentsirovki.

Comparative morphological, cytospectrophotometric and immunochemical studies were carried out on 26 hepatocarcinomas of various malignancy excised from 21 F1 (CBA X C57B16) mice. It has been shown that in morphologically similar hepatomas the ploidy level and alpha-fetoprotein production intensity may vary markedly. Highly differentiated carcinomas usually of smaller sizes and homogeneous morphology have the modal class nuclei with tetraploid (6 cases) or octaploid (3 cases) DNA content. In moderately- and low-differentiated carcinomas the diploid class of nuclei significantly increased (in 4 out of 6 tumours). Large tumours morphologically heterogeneous according to the differentiation level had polymodal DNA distributions with predominating tetraploid nuclei (II cases).

[Oncological characteristics of C57Bl/6JY mice]. / Onkologicheskaia kharakteristika myshei linii C57Bl/6JY.

The oncological characteristic is presented for C57BL/6JY mice widely used in experiments. The mice over eighteen month had different spontaneous neoplasms among which hemoblastoses prevailed. The influence of sex, age and vaccination on the rate of spontaneous neoplasms in these mice is analyzed.

[Morphological and cytochemical characteristics of spontaneous hemoblastoses in AKR mice]. / Morfologicheskaia i tsitokhimicheskaia kharakteristika spontannykh gemoblastozov myshei linii AKR.

Spontaneous hemoblastoses of AKR mice are widely used in experimental oncology and hematology. To study their morphological characteristics, 500 AKR mice were used. Of these, 400 animals were followed up throughout their lives. Ten animals were sacrificed monthly out of the group of 100 rats. All the animals which died or were sacrificed were autopsied and subjected to cytological and histological studies. Besides, 36 animals with hemoblastoses were examined cytochemically for the activity of acid and alkaline phosphatases, peroxidase and nonspecific esterase and glycogen. Analysis of the data obtained suggests that hemoblastoses of AKR mice are the generalized forms of lymphosarcoma, characterized by a significant degree of cytochemical and cytological heterogeneity.

[Oncological characteristics of AKR/JY mice]. / Onkologicheskaia kharakteristika myshei linii AKR/JY.

The oncological characteristic of AKR/J mice widely used in experimental investigations is presented. The incidence of spontaneous hemoblastoses in this subline is sufficiently high during the last ten years, that allows to use this subline as an experimental model of hemoblastoses. The analysis of the influence of sex factors, age and vaccination on the rate of spontaneous tumours of the lymphoid tissue is given.

[Blastomogenic activity of 2-aminoacetophenone in Syrian hamsters]. / Blastomogennaia aktivnost' 2-aminoatsetofenona u siriiskikh khomiakov.

The blastomogenic activity of 2-aminoacetophenone (2-AAP)--one of the aromatic triptophan derivatives, found in the urine of leukemic patients, was studied on nonlineal Syrian hamsters, 2-AAP would induce the increased total incidence of tumors and raise the frequency of endocrine system tumors, especially adrenal adenomas. The results of the experiment indicate an insignificant blastomogenic activity of 2-AAP and correlate well with the results obtained on lineal mice.

[Morphological analysis of spontaneous hemoblastoses in dogs and cats]. / Morfologicheskii analiz spontannykh gemoblastozov sobak i koshek.

Information of the frequency and morphological characteristics of spontaneous hemoblastoses in dogs and cats observed in 1966-1978 are presented. Hemoblastoses were diagnosed in 90 dogs and 12 cats. Lymphoproliferative diseases were most frequent: lymphosarcomas (80 cases) and lymphocytic leukemias (11 cases). Ten dogs had mastocytomas and one--myeloid leukemia. The cell composition of the organs and tissues involved permitted to distinguish 3 cellular variants of lymphosarcoma: poorly differentiated, lymphoblastic, and prolymphocytic; in both species the poorly differentiated type of lymphosarcoma was predominant (47 cases). It is recommended to use spontaneous hemoblastoses of dogs and cats as an experimental model for investigations of the pathogenesis and therapy of human leukemias.