[Nucleic factor in the ascitic fluid in human ovarian tumors]. / Nukleinovyi faktor v astsiticheskoi zhidkosti pri opukholiakh iaichnika cheloveka.

Previously, there was found a low molecular weight 5S DNA in ascitic fluid of rats and mice with experimental tumors. This report shows the presence of the nucleic factor in ascitic fluid of ovarian tumor patients, its electrophoretic mobility methylene blue staining and the affinity to hydroxyapatite being similar to that in animals. Whereas in patients with persistant ascitis of a nontumor origin such factor was not detected.

[Resistance of ascitic fluid immunosuppressive factor DNA to pancreatic deoxyribonuclease]. / Ustoichivost' k pankreaticheskoi dezoksiribonukleaze DNK immunodepressivnogo faktora astsitnoi zhidkosti.

It was found that incubation of Ehrlich tumour ascitic fluid with pancreatic DNAse does not result in a destruction of 5S DNA in the immunodepressive factor. After phenol deproteination of the ascitic fluid the resistance of this nucleic factor to DNAse is lost. It is possible that the native nucleic factor is represented by DNP and contains a protein component. During polyacrylamide gel electrophoresis the mobility of the nucleic factor labelled with [3H]-thymidine and isolated after chromatography on hydroxyapatite is found to be nearly the same as that for transferine.

[Effect of the nucleic factor on lymphocyte cytotoxicity]. / Vliianie nukleinovogo faktora na tsitotoksichnost' limfotsitov.

Under study was the influence of the nucleic factor, isolated from Ehrlich tumor ascitic fluid, on cytotoxicity of in vitro lymphocytes of CC57Br mice immunized by L-cells. In a dose of 5--10 mkm/ml this factor was shown to suppress cytotoxicity of splenic cells as well as that of lymph nodes cells of previously immunized mice. Cellular DNA of non-lineal SHR mice, hepatic RNA of normal mice C3Ha (their genotype being similar to L-cells), of non-lineal SHR mice and syngeneic CC75Br in the same concentration failed to produce such effect.

Low-molecular weight nucleic acids in the blood of rats with Zajdela's hepatoma.

The phenolic method was employed to isolate 2--3 microgram/ml of nucleic acid from rat blood serum. Electrophoresis in an 8% polyacrylamide gel revealed 3 fractions corresponding to 7--9S RNA, and a highly polymer material retained at the beginning of the gel. The blood of the rats with transplanted Zajdela's hepatoma, pre-treated with CCl4, contained an immunodepressive nucleic factor (5S DNA) undetected in healthy animals. This factor may contribute to the suppression of antitumor immunity. The nucleic factor was not detected following treatment with CCl4 alone. It is suggested that the liver hinders nucleic factor transfer from the tumor environs into the blood.

[Structural peculiarities of the nucleic factor from ascitic fluid of tumors]. / Nekotorye osobennosti nukleinovogo faktora ia astsitnoi zhidkosti pri opukholiakh.

Several characteristics of the nucleic factor of tumors which is thought to play an important role in suppression of tumor immunity was investigated. This nucleic factor differs from native double-stranded DNA of eukaryotic nuclei by base composition (A: T: G : C = 1: 1.44 : 0.91: 0.69); its affinity to GAP and hyperchromic effect were lower than those in native DNA. Heating above 80 degrees in 1 N KOH destroyed the nucleic factor to fragments that could not be detected in 8% PAK electrophoresis. The results of this and previous reports lead us to a hypothesis that the nucleic factor is a DNA molecule consisting of single- and double-stranded regions, as well as short insertions of RNA. The double-stranded regions in this molecule possess non-parrallel breaks.

[Nonspecific suppressive effect of Ehrlich tumor ascitic fluid on transplantation immunity]. / Nespetsificheskoe podavliaiushchee deistvie astsitnoi zhidkosti opukholi na transplantatsionnyi immunitet.

The influence of syngeneic Ehrlich ascites tumour fluid on the survival of allogeneic skin allografts was investigated on CC57BR mice. A 3--4-day delay of the allograft rejection in mice injected with ascitic fluid was revealed. Preliminary transplantation of such allograft to mice with Ehrlich tumour produced no intensification of the immunodepressive action of the ascites fluid obtained from them. The data obtained indicated the preferential significance of the antigen-independent immunosuppressive factors of ascites tumour fluid in the suppression of the transplantation immunity in vivo.

[Extracellular nucleic acid in ascitic experimental tumors]. / Vnekletochnaia nucleinovaia kislota v astsitnykh éksperimental'nykh opukholiakh

By using the phenol method, employed for obtaining RNA, the factor possessing electrophoretic mobility close to that of more rapidly migrating conformomer 5 S p-RNA and resistant to the action of pancreatic RNA-s was isolated from noncellular ascitic fluid, Ehrlich and NK/Ly tumors, hepatoma 22a, Zajdela hepatoma, ovarian ascites tumor in rats. This factor is suggested to participate in suppression of antitumor immunity in cancer.

[Study of the factor of ascites fluid of Erlich tumor]. / Issledovanie faktora astsiticheskoi zhidkosti opukholi Erlikha

The factor of nucleic nature was isolated by phenol method from acellular ascitic fluid of Ehrlich tumor. DNA was found to be the main component of the factor concerned as indicated by chemical analysis after its purification with preparative electrophoresis in 2.5% polyacrylamid gel or centrifugation in CsCl gradient. Moreover, the factor can be destroyed in incubation with DNA-s. It is not improbable that this factor consists also of small amounts of RNA.

[Influence of fast electrons on the nucleic acid level and the biosynthsis of RNA in cells of the ascites tumor NK/Ly and the spleen of tumor-bearing mice]. / Vliianie bystrykh élektronov na soderzhanie nukleinovykh kislot i biosintez RNK v kletkakh astsitnoi opukholi NK/Ly i selezenke myshei-opukholemositelei

The results of investigations on total nucleic acids content and RNA turnover in the cells of tumor NK/Ly and of the spleen in tumor-bearing mice after single exposure to fast electrons are described. In every case the irradiation results in reliable changes of parameters under study. The pattern of changes in nucleic acids content and turnover in the spleen after the exposure to fast electrons is in a good agreement with the available data concerning the influence of x- and y-radiation. The irradiation action on nucleic acids content and turnover in ascites tumor NK/Ly cells is qualitatively and quantitatively similar to that in splenic cells.