Eksperimental'naia onkologiia最新文献

Nutrition (general caloricity, protein and fat content), immune system indices, hormonal status, neovascularization or proliferative processes are discussed in the review from the standpoint of their influence on mechanisms of the antitumour resistance. It is confirmed that such peculiarities of nutrition as moderate reduction of general caloricity and decrease of fat content can be considered as means increasing the antitumour resistance.

Two tissue-specific water-soluble antigens AG1 and AG2 are revealed in immunobiochemical analysis of human squamous epithelium extract. It is established that AG2 with the molecular weight of about 10 kD is of immunodiagnostic significance, being a marker of squamous cell carcinoma of different organs.

The association of simian T-cell leukemia virus with baboons malignant lymphoma was studied. Proviral DNA integrated in cells of lymphoid organs was detected in 19 of 21 sick animals examined. Only 4 of 10 monkeys from high risk colony without clinical manifestations had virus-specific sequences in their cellular DNAs. As a rule, S(H)TLV-I-infected cells monoclonally proliferated both in lymphomatous and healthy baboons. The restriction patterns with EcoRI, HindIII, PstI, BamHI of S(H)TLV-I provirus were similar but not identical to those of prototype HTLV-I and STLV-I isolates.

Genotoxicity of tar samples collected at the Kemerovo and Altai by-product coke plants has been studied, the contribution of benz(a)pyrene (BP) into the total mutagenic activity of extracts being estimated. Both direct and indirect mutagenicity of the samples is determined in the Ames test. A direct mutagenic effect of coal tar may be attributed neither to the BP action nor to other polycyclic aromatic hydrocarbons. The onset of the His revertant induction in Salmonella typhimurium strains Ta 100 and TA 97 treated with the coal tar activated by the S-9 mixture is observed in doses containing BP an order lower than threshold of its activity found in sole experiment. The highest mutagenic effect of the activated coal tar is observed at a dose containing the minimal active sole dose of BP (0.72-1.12 micrograms per plate).

It has been shown that the local radiation therapy, and also radiation therapy modified by the short-term hyperglycemia really increase the life-span of rats with Walker 256 carcinosarcoma. At the same time the metastatic process also increases, especially after the modified radiation therapy. The total irradiation of experimental animals in a dose of 50 sGy before the modified radiation therapy considerably decreases the frequency of metastatic process. A conclusion is drawn that the total irradiation has a prophylactic influence on metastases under conditions of modified radiation therapy.

The data on the photodamage of biomolecules and experimental tumours by a hematoporphyrin derivative activated with laser radiation are presented. Inhibition of the tumour growth and prolongation of the life-span of treated tumour-bearing animals are observed.

The intravenous injection of the recombinant tumour necrosis factor (rTNF) to the C57BL/6 mice at a dose of 10(4) U 1.4 and 24 hours before or 4 hours after the intravenous inoculation of the LL (Lewis carcinoma) or MM-4 (B-16 melanoma) cells was found to be accompanied by a significant increase in the number of hematogenic metastases in the lungs of animals. The above rTNF effect could be considerably inhibited by the single heparin injection.

The antitumor and immunoadjuvant action of water-soluble N-vinylpyrrolidone co(ter)polymers of different chemical structure is studied. It is established that terpolymer N-vinyl-pyrrolidone (VP)--crotonic acid (CA)--n-crotonoylaminophenol inhibiting the growth of hepatoma 22a by 50-60% possesses an antitumoral action, while copolymer VP-CA has an immunoadjuvant action. These properties of co(ter)polymers are due to their chemical structure and molecular weight, but they do not always correlate between themselves.

Tetramethylthiuramdisulfide (TMTD) decreasing the formation of hepatomas in inbred rats with the subsequent intraperitoneal administration of nitrosodiethylamine (NDEA) is established not to affect the NDEA-induced expression of the heteroorganic antigens of nonhistone chromosomal proteins of the kidney nature associated with the hepatoma and regenerating liver cells of rats. It is supposed that changes in the NDEA metabolism induced by the preceeding action of TMTD, obviously, do not influence the hepatocarcinogenic potencies relative to stimulation of cell proliferation.

Artificial hyperglycemia (AHG) used in the cancer treatment considerably increases the insulin and S-peptide content in blood, decreases the glucagon concentration and tissue glucose tolerance. The changes are reversible, have a functional character, that indicates the absence of a disbalance in hormonal mechanisms of carbohydrate metabolism control as well as marked disorders of the pancreas function. In order to achieve a wider range of indications for using AHG in complex schemes of the cancer treatment, it is necessary to take measures on optimization of the carbohydrate metabolism state which should be controlled by the suggested complex of laboratory tests.