Presence of ribonucleotide sequences complementary to Rous sarcoma virus (RSV) RNA in chicken cells infected with RSV.

RNA--RNA molecular hybridization between [125I] RNA from Rous sarcoma virus virions and RNAs isolated from various subcellular fractions, i.e. nuclei, mitochondria, free and membrane-bound polyribosomes, from tumors induced by RSV in chickens resulted in the formation of RNAase-resistant hybrids only with the RNA of mitochondria and membrane-bound polysomes. The origin of complementary regions in the RNAs from these organelles is discussed.

The expression of virus-specific nucleotide sequences in Rous sarcoma cells.

Poly(A)-enriched virus-specific mRNAs (v-mRNA) are revealed in the subcellular fractions (nuclei, mitochondria, polyribosomes and cytosol) from chicken and hamster Rous sarcoma cells. The qualitative and quantitative differences in v-mRNA populations from permissive and non-permissive tumors are shown. The sedimentation analysis of v-mRNAs allowed to ascertain the presence of three molecular classes of v-mRNA in nuclei and cytoplasm of chicken Rous sarcoma cells (35S, 28S and 22S, and 35S, 26-28S and 20S, respectively). While two size classes (33S and 20S) are shown in hamster Rous sarcoma nuclei, only 24S v-mRNA is revealed in the cytoplasm of its tumor tissue. Thus, the oncovirus gene expression is restricted in the non-permissive tumor cells, unlike of the permissive chicken Rous sarcoma cells, both in the level of transcription, and in the processing and transfer v-mRNAs from nucleus to cytoplasm. The virus gene function peculiarities in the tumors of birds and mammals are discussed.

Culture of human cells obtained with DNA from chick Rous sarcoma.

An infectious process was reproduced in the culture of chick embryo cells by means of DNA isolated from Rous chick sarcoma tissue (Carr-Zilber strain). This DNA preparation displays biological activity also in the culture of human embryo diploid cells (HEDC) which is manifested in: 1. discontinuous synthesis of avian oncovirus group-specific antigen; 2. enhancement of proliferative activity and morphological transformation of human cells; 3. continuous presence of virus-specific sequences as revealed by DNA/RNA hybridization. Producing complete oncornavirus by means of DNA isolated from Rous chick sarcoma in HEDC was unsuccessful. DNA preparation from gs negative chick embryo cells shows no infectious activity in HEDC culture.

Study of sequences of DNA of the human papilloma virus genotypes 6 and 16 in patients with cancer of vulva and cervix uteri.

Puntaction hybridization method was used to determine the incidence of the human papilloma virus infection in cases with the squamous cell cancer of the vulva and cervix uteri. The presence of sequences of DNA of the HPV genotype and 16 was found in 74.2% of cases, which points to a suspicion for the involvement of the above viruses in etiology of cervix uteri cancer, as well as vulva cancer.

[Subcellular localization of low-molecular RNA in the cells of chick embryos]. / Izuchenie subkletochnoi lokalizatsii nizkomolekuliarnykh RNK kletok émbrionov kur.

The subcellular distribution of chick embryo low molecular weight RNAs has been studied by the thermal phenol fractionation procedure. The major part of 8SII RNA, earlier discovered in some oncornaviruses and normal cells, was extracted by phenol at 4%. Our results thus give evidence of the cytoplasmic localization of this RNA. Another part of 8SII RNA, which has been extracted at 65 degrees, is thought to consist of newly synthesized molecules located in the nuclei. A similarity in subcellular distribution of low molecular weight RNAs from chick embryo and rat liver has been obtained, i. e. such a distribution may be of universal nature.

[Effect of thyroxine, insulin and cholesterol on the amount of cyclic adenosine monophosphate in normal and oncornavirus infected cells]. / Vliianie tiroksina, insulina i kholesterina na soderzhanie tsiklicheskogo adenozinmonofosfata v normal'mykh i zarazhennykh onkornavirusom kletkakh.

The intracellular concentration of cyclic AMP in normal cells and in cells infected with the Rous sarcoma virus (chicken fibroblasts) was determined by the method of saturation analysis (method of concurrent binding with protein). Thyroxine (2 mcg/ml) increased the level of cyclic AMP both in normal and infected cells, insulin (2 mcg/ml) decreased the concentration of cyclic AMP in infected cells, but cholesterol (5 mcg/ml) exerted no effect on this parameter in infected cells. The data are discussed from the point of view of a possible influence of hormones on the cholesterol accumulation in cells and on the adenylatecyclase activity in cell membranes.

[Antiviral activity of several nucleic acid components methylated in the N-position]. / Protivovirusnaia aktivnost' nekotorykh metilirovannykh v N-polozhenii komponentov nukleinovykh kislot.

The degree of reproducation of Rous sarcoma, mumps, and vaccinia viruses in chick embryo cell culture incubated in the presence of 9-methyladenine was considerably lower than reproducation of these viruses in the cells propagated without this substance. 1-methyluracil and 1-methylthymine reduced considerably the amount of Rous sarcoma virus produced by the cells as compared to the controls. The presence of these substances in the maintenance medium does not prevent virus infection of the cells, and their effect appears to be associated with nonspecific action on the late stages of the virus reproduction.

[Use of liposomes for vaccines design]. / Ispol'zovanie liposom dlia konstruirovaniia vaktsin.

Reviews reports on the creation of liposomal vaccines published during recent 25 years. Describes methods of antigen and immunomodulator incorporation in liposomes and their immunogenic properties. Presents data on development of influenza vaccines and prospects for their utilization as universal carriers of viral and bacterial antigens.

[The physicochemical characteristics of a chick embryo hydrolysate-based nutrient broth]. / Fiziko-khimicheskaia kharakteristika pitatel'nogo bul'ona na osnove gidrolizata kurinykh émbrionov.

The composition of dried nutrient broth, prepared on the basis of the fermentative hydrolysate of waste chick embryos, has been studied with the use of physicochemical analytical methods. The parameters of total and amino nitrogen, the content of amino acids, peptides, lipids, carbohydrates and microelements have been determined. The qualitative analysis of the peptide composition of the broth has been made. The heterogeneity of peptides with respect to their molecular weights (200--15,000 D and over) has been noted. As regards its physico-chemical composition, the broth is a valid medium, suitable for the cultivation of a wide spectrum of microorganisms.

[Quantitative cytochemical detection of enzymes in cultured cells following infection with Rous virus]. / Kolichestvennoe tsitokhimicheskoe vyiavlenia fermentov v kul'turakh kletok posle zarazheniia viruson Raus

The method of visual quantitative estimation was employed to determine the index of enzymes activity in embryonal cells cultures infected with Rous virus. In early terms (1-7 days after infection) a moderate production of diformazane was noted in the presence of glucoso-6-phosphatiosomerase, phosphoglucomutase, pyruvatoxidase, NAD. H2- and NADP. H-2-diaphorase, other enzymes showing no distinquishable deviations in the activity, as compared with the normal culture. In later terms (13-27 days) during the proliferation of the transformed cells there was found an increased level of the glycolysis enzymes activity, pentose cycle, hydrolysis of ortho-phosphoric acid monoethers and reduced lemon acid cycle and tissue respiration. Cytoplasmatic vacuoles formed in the transformed cells seem to represent hypertrophic lysosomes and phagolysosomes.

[Incorporation of influenza virus antigens into the envelope of the avian oncornavirus]. / Vkliuchenie antigenov virusa grippa v obolochku ptich'ego onkornavirusa.

The mixture of influenza virus and pseudotype of Rous sarcoma virus--RSV (PAB-A) grown in chick embryos or cell culture of chick fibroblasts produces a progeny which can be partially neutralized by a heterologous immune serum. The fraction of viral particles, the transformation activity of which is susceptible to suppression by both homologous anti-RSV (PAB-A) and heterologous serum, immune to influenza virus, amounts to approximately 20%. After passivation, these particles lose this property which suggests a non-genetical character of the phenomenon. Hence, dual infection results in phenotypic mixing and formation of particles with nucleoproteid of RSV (PAS-A) which contain antigens of avian sarcoma and influenza viruses in their envelopes.

[Oncornavirus activation and accumulation in cell cultures under the influence of hormones]. / Izuchenie aktivatsii i nakopleniia onkornavirusa v kul'turakh kletok pod vliianiem nekotoryk gormonov.

Sex hormones (testosterone, estradiol) and thyroxine would activate irregularly the production of the specific group antigen (GS-antigen) of avian ribodesoxyviruses in the culture of "normal" chick embryonal cells (CEC, phenotype C/O, GS-). The mentioned hormones as well as hydrocortisone and insulin would not prevent the Rous sarcoma virus (RSV) infecting of CEC, render no essential action on the accumulation of RSV in the infected CEC culture, and failed to activate the formation of mature RSV in virogenic cultures of rat (XC, R--B77) and mice cells (DBA--B77).

[Search for viral genetic information in human tumor DNA by means of transfection]. / Poiski virusogeneticheskoi informatsii v DNK opukholei cheloveka metodom transfektsii.

In embryonal human cell culture there was found the biological activity of DNA preparations, obtained from peripheral blood cells of acute leukemia patients, which was manifested in the production of virus-like RNA-containing particles, as evidenced by the radioisotope analysis findings and by the reverse transcriptase content in these particles. Also, a rapid growth of the cultures was noted. The DNA preparations from rhabdomyosarcoma, neurinoma and synovial sarcoma in man would cause only an enhancement of human embryonal cell cultures growth. No production of virus-like particles in the latter was noted.

[A change in the relative concentration of individual fractions of low molecular weight nuclear RNA in tumor tissues]. / Izmenenie otnositel'no soderzhaniia otdel'nykh fraktsii nizkomolekuliarnykh iadernykh RNK v opukholevykh tkaniakh

Low molecular weight nuclear RNAs (LMWN RNAs) of normal and neoplastic tissues: the rat liver and Zajdela hepatoma, mouse spleen and NK/Ly ascites tumor, as well as the cultures of normal chick embryo fibroblasts and of those transformed with Rous sarcoma virus were studied by electrophoresis in 8% and 15% polyacrylamide gels. As a result of the study no qualitative differences, i.e. differences in the number of LMWN RNA main fractions and their electrophoretic mobility were found. But there were revealed quantitative variations in the relative amount of definite fractions of these RNAs. An increase of the U3 RNA content in ascites tumors may be connected with an enhancement of the ribosomal RNA synthesis. Variations in the content of low molecular weight RNAs in oncogenic virus transformed cells may reflect an excessive synthesis of low molecular weight viral RNAs during the process of virus reproduction. The quantitative alterations observed seem to be of special value since LMWN RNAs are likely to perform regulatory functions.

[Transfer of the genetic information of oncornaviruses by means of tumor cell DNA]. / Perenos geneticheskoi informatsii onkornavirusov s pomoshch'iu DNK opukholevykh kletok

The infection process was reproduced in the culture of chick embryonal cells by means of: a) DNA isolated from chick Rous sarcoma (Carr-Zilber strain); b) DNA from blood cells of chicks with myeloblastosis (strain A); c) DNA from Rous virus malignified (Prague strain) rat cells (XC). Antigenic properties of the virus, transfected with DNA from chick Rous sarcoma, would differ from the original parental strain (Carr-Zilber RSV), that evidences the possibility of a partial transfer of genetic information in transfection. A suggestion is made on four presumable variants of oncornaviruses transfection by means of tumor cells DNA.