[Comparative study of lymph node gangliosides and blood serum of normal and T-lymphotrophic baboons]. / Sravnitel'noe izuchenie gangliozidov limfaticheskikh uzlov i syvorotki krovi pavianov-gamadrilov v norme i pri T-kletochnykh limfomakh.

The gangliosides from the lymph nodes and blood sera of normal and T-lymphomic baboons were studied. In lymph nodes the major gangliosides were identified as GM3 and GD3, those in blood sera--as GM3, GM1 and GD3. Gangliosides GM3 and GD3 contained N-acetyl as well as N-glycoloyl neuraminic acids. In gangliosides isolated from lymph nodes and blood sera of T-lymphomic baboons the levels of N-glycoloyl neuraminic acid markedly exceeded that in normal tissues. In tumour lymph nodes the GM3/GD3 ratio was shifted towards GD3.

[Ganglioside (GD3) in serum of cancer patients]. / Gangliozid (GD3) v syvorotke krovi rakovykh bol'nykh.

Gangliosides were studied in blood serum of healthy volunteers and of patients with cancer of mammary gland and stomach. Blood serum of the majority of patients with cancer and only 15% of healthy persons were shown to contain ganglioside GD3 which was detected in blood of patients with some other tumors.

[Gangliosides GM3 and GD3 in human stomach and breast tumors]. / Gangliozidy GM3 i GD3 v opukholiakh zheludka i molochnoi zhelezy cheloveka.

Gangliosides of human gastric and mammary tumours and of homologous normal tissues were studied by using biochemical methods and specific antisera. It was found that in most cases GM3, GD3 and GM1 are predominant gangliosides, whereas several polar components are minor ones. A comparison of the relative amount of ganglioside fractions revealed that in gastric tumours the per cent content of polar compounds is higher than in intact tissue; however, the absolute content of all gangliosides is markedly increased. A comparative study of the composition of mammary tumour and normal tissue gangliosides demonstrated two types of changes: i) the absolute content of all gangliosides in tumour tissue was increased and, ii) the increase in the content of total gangliosides was paralleled with the appearance of a new fraction (presumably GM4), the decrease of the GD3 content and the disappearance of polar gangliosides. A possible mechanism of this effect is discussed.

[Gangliosides modulate lipoxygenase oxidation in human lymphocytes]. / Gangliozidy moduliruiut lipoxsigenaznoe okislenie v limfotsitakh cheloveka.

Using reverse phase high performance chromatography with UV-detection, the arachidonic acid cascade in human peripheral blood lymphocytes (PBL) was studied. It was found that PBL oxidized arachidonic acid via the lipoxygenase pathway, 12-hydroxyeicosatetraenoic acid (12-HETE) being the major metabolite of endogenous arachidonic acid. Exogenous arachidonic acid added to human PBL suspensions increased 12-HETE synthesis 5-7 times. In another experimental series the effects of gangliosides (GD3, GM1 and GM3) on lipoxygenase-catalyzed oxidation of arachidonic acid in human lymphocytes were investigated. All the gangliosides tested stimulated PBL to secrete 12-HETE both from endogenous and exogenous arachidonic acid. In most cases the stimulating effect of GD3 was much more apparent that those of GM1 and GM3.

[Ganglioside GM3 derivatives and their immunomodulating effect]. / Proizvodnye gangliozida GM3 i ikh immunomoduliruiushchii éffekt.

The derivatives of ganglioside GM3-NeuLacCer. NeuLacSph and NeuAcLacSphAc-were obtained and their immunomodulating properties studied. These substances are shown to inhibit lymphocyte blast-transformation independently of their ceramide structure. On the contrary, the stimulation by the above GM3-derivatives of Con A-induced T-suppressor activity depends significantly on the structure of their ceramide moiety.

[The effect of gangliosides on experimental influenza infection]. / Vliianie gangliozidov na éksperimental'nuiu grippoznuiu infektsiiu.

Experiments in two strains of mice; CBA, susceptible to influenza, and CBAXC57Bl/cXFl, resistant to it, demonstrated stimulation of influenza infection caused by gangliosides. The stimulating effect of gangliosides (GMl, GDla, GTlb) seems to be explained by their insertion into plasma membranes of epithelial cells of the respiratory tract and by an increase, due to it, of the number of superficial virus-specific receptors.

[New types of polymerizable phosphatidylcholines, synthesis and properties]. / Novye tipy polimerizuemykh fosfatidilkholinov, sintez i svoistva.

Phosphatidylcholines bearing 11-methacryloylaminoundecanoyl or 12-keto-10-octadecanoyl residues were synthesized. Both phosphatidylcholines are easily polymerized under UV irradiation. The second phospholipid produces liposomes which, after polymerization, acquire an increased stability to deteriorating factors (organic solvents, detergents and human plasma).

[Effect of prostaglandins on lipid transfer between high- and low-density lipoproteins in human plasma]. / Vliianie prostaglandinov na lipidnyi perenos mezhdu lipoproteinami vysokoi i nizkoi plotnosti plazmy cheloveka.

Prostaglandin (PG) E1 was shown to stimulate the transfer of phosphatidylcholine and cholesterol esters from human high density lipoproteins to low density lipoproteins. The enhancement of the interlipoprotein lipid transfer by PGE1 was observed both at low prostaglandin concentrations under conditions of spontaneous exchange as well as in the presence of the lipoprotein-depleted plasma and the partly purified lipid transfer plasma protein. At the same time PGE2 showed no significant influence on the interlipoprotein lipid transfer. It is supposed that the effect of PGE1 is due to the PGE1-induced reorganization of the high density lipoprotein surface and that the PG-lipoprotein interaction is a factor which regulates cholesterol homeostasis.

[Glycosphingolipids from human T-lymphoma MOLT-4 cells]. / Glikosfingolipidy kletok T-limfomy MOLT-4 cheloveka.

The glycosphingolipids of human lymphoma MOLT-4 cells were studied, using biochemical methods and specific antisera to gangliosides. The major neutral glycosphingolipids were found to be glucosyl- and lactosyl ceramides. GM3, GM2, GM1 and GD1a were identified as ganglioside components.

[Inhibition of the cytotoxic activity of natural killer cells by glycosphingolipids. Effect of the structure of carbohydrate chains]. / Ingibirovanie tsitotoksicheskoi aktivnosti estestvennykh killerov glikosfingolipidami. Vliianie struktury oligosakharidnykh tsepei.

The ability of various glycosphingolipids to inhibit the cytotoxic activity of natural killer (NK) cells was studied. The inhibitory effect was found to depend on the structure and concentration of the glycosphingolipids. Gangliosides SiaLacCer inhibited the NK activity most effectively and their inhibitory effect depended on the structure of sialic acids: the N-acetyl form was more active than the N-glycoloyl form. Elongation of the carbohydrate chain decreased the inhibitory effect and monosialogangliosides NeuGcGgOse3Cer and NeuAcGgOse4Cer were practically inactive. The inhibitory ability of disialogangliosides depended on the structure of the carbohydrate chain as well as on the structure and attachment site of the sialic acids. Previously it was found that ganglioside (NeuAc)2LacCer, which is absent or very low in normal blood, is produced by a number of tumors and alongside with NeuAcLacCer is present in elevated amounts in the blood of tumor-bearing subjects. Elevated concentration of these gangliosides in the blood of tumor hosts may inhibit apparently the NK activity and thus contribute to the escape of tumor cells from host immune surveillance.

[Glycosphingolipids and antitumor immunity]. / Glikosfingolipidy i protivoopukholevyi immunitet.

Glycosphingolipids are immunogenic components of cell surface whose composition and structure change during the cell transformation. The contemporary state of the question about the influence of glycosphingolipids on specific and non-specific antitumour immunity is considered. The available information about shedding of glycosphingolipids from the tumour cell surface, about the change of the ganglioside content in blood serum of the tumour host and about the effect of glycolipids on immunocompetent cells is analyzed. The results obtained by the authors in studies of the influence of glycosphingolipids on effector cells of the body natural resistance system to tumour are discussed.

[Gangliosides of murine B-lymphoma MORC-406]. / Gangliozidy B-limfomy MORC-406 myshei.

Gangliosides of murine B-lymphoma MOPC-406 were studied, using biochemical methods and specific antibodies. The lymphoma was found to contain 12 ganglioside components which were identified as N-acetyl and N-glycoloyl forms of SiaLacCer, SiaGgOse3Cer, II3SiaGgOse4Cer, IV3SiaGgOse4Cer and II3IV3Sia2GgOse4Cer.

[DNA-phospholipid interactions. A study using lipid-specific fluorescent and photoreactive probes]. / DNK-fosfolipidnoe vzaimodeistvie. Issledovanie s pomoshch'iu lipidspetsificheskikh fluorestsentnykh i fotoreaktivnykh zondov.

The interaction of phospholipids with phage T7 DNA was investigated using anthryl-vinyl-labeled and photoactivable phosphatidylcholine and sphingomyelin. Fluorescence polarization studies demonstrated that, in the presence of DNA, the fluorophore mobility is diminished as its distance from the polar head-group is increased. Immobilization of lipid chains is enhanced by Ca2+ ions, the effect being more pronounced for sphingomyelin than for phosphatidylcholine derivatives. On the other hand, phospholipids with a photoactivable group could not be crosslinked to DNA in the DNA-phospholipid complexes, evidencing against the presence of contacts between lipids and DNA.